CA2101879A1

CA2101879A1 - Chlorine-free multifunctional resins for paper finishing

Info

Publication number: CA2101879A1
Application number: CA002101879A
Authority: CA
Inventors: Jurgen Reiners; Hans-Josef Laas; Joachim Konig; Helmut Reiff; Joachin Probst; Bruno Bomer; Reinhard Halpaap; Fritz Puchner; Harro Traubel
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1992-08-07
Filing date: 1993-08-04
Publication date: 1994-02-08
Also published as: EP0582166A1; JP3287660B2; DE59305310D1; EP0582166B1; ES2098602T3; ES2098602T5; US5503714A; JPH06173196A; US5739249A; EP0582166B2

Abstract

ABSTRACT

BAYER AKTIENGESELLSCHAFT 5090 Leverkusen, Bayerwerk Konzernverwaltung RP
Patente Konzern WX/wa/c199 Chlorine-free multifunctional resins for paper finishing The invention relates to a new process for the prepara-tion of cellulose-containing material provided with a dry-strength and wet-strength finish and/or sized, characterised in that the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I), which contains tertiary amino and/or ammon-ium groups, optionally polyether units and optionally hydrophobic groups.

Description

2 1 01 ~ 1~

Polyamine-epichlorohydrin resins and polyamide amine~
epichlorohydrin resins having a reduced organic chlorine content are industrially available, the applica-tion or product properties, in particular the effectiveness of the products, being retained virtually in full. Such resins have long been employed for improving the dry and wet strength of paper. Cationic polycondensates contain-ing hydrophobic radicals, for example based on fatty acid-modified polyamines, are also suitable as sizing agents for paper. The orga~ic chlorine content is com-posed of a certain amount of chlorohydrin functions bonded in the resin, and a chlorine comp~nent originating from the low-molecular-weight secondary ~omponents chloropropanediol and dichloropropanediol When used as a wet-strength agent, an aqueous s~lution of the polycondensa-te is added to a pulp suspension, from which the sheet of paper is formed by dewatering. If the resins are adsorhed incompletely onto the cellulose, in the case of a halogen-containing wet-strength agent a certain proportion of organic halogen compounds pass into the effluent from the papermaking, and can be detected there as the so-called AOX value (AOX = adsorbable organic halogen) tDIN 38 409 H14). For environmental protection reasons, introduction of AOX into the waste-water from paper-mills should be avoided or at least kept as low as possible.

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Although the content of the sec~ndary component in many products is already well below 0.1 %, it is desired to employ chlorine-free products.

Halogen-free papers cannot be produced using the above-mentioned auxiliaries. The term "halogen-free" here should be used in the strictest sense only for products which really do contain no haloqen.

Methods are furthermore already known from the prior art for chlorine-free provision of a wet-strength finish, isocyanates being employed as the raw ~aterials. The following procedures are possible here: 1. treatment of paper with masked polyisocyanates, 2. use of reactive mixtures which react in the substrate to give polyureth-ane, 3. treatment of paper with free polyisocyanates in organic solvents.
However, the known wet-~trength agents are not satisfac-tory in all requirements.

DE-A 3 102 038 describes basic polyurethanes which ,; contain isocyanates which are blocked via oxime groups and are split off during reaction with the cellulose. The disadvantage of this method is that organic radicals, which are not substantive with respect to cellulosel may enter the circulating water of the paper machinery.

A two-component system for coating paper, compr,ising a polyfunctional isocyanate and a compound which is reac-tive to isocyanates and contains active hydrogen, is ' : :

Le A 29 038 - 2 -.

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proposed in FR-A 2 360 71~o At the end, the finished paper contains 0.5 to 35 ~ by weight of reacted polyurethane.

EP-A 0 017 598 describes a~ueous dispersions of poly-urethanes, the isocyanate groups of which are blocked.
After application to the substrate, the isocyanate groups must be demasked by addition of a metal catalysk or a salt of a tertiary amine. The isocyanate groups thereby released react with the cellulose during the heat treat-ment.

.
US-PS 3 702 781 desaribes polyurethanes having reactive NCO groups, which are appLied to paper in organic solvents.

In the process according to D~-A 3 102 038, the isocyan-lS ate group must be produced in situ by deblocking protect-ive groups. A disadvantage here is that the protective groups have no affinity for the fibre and therefore can be introduced into the water circulation of the paper machinery. Moreover, higher temperatures (>130C) than those which the paper reaches while passing through the drying part of the paper machinery are required for the deblocking. ~he contact times in the drying part (c60 seconds) as a rule are not sufficient to achieve quantitative deblockingO In the case of US-PS 3 702 781, in which free isocyanates are used, it is necessary because of the high viscosity to use organic solvents, which have to be disposed of by the paper producer and Le A 29 038 _ 3 _ .
- .. . .

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therefore should be avoided as far as possible.

Watc~-dispersible polyisocyanate formulations which contain free NCO groups and are suitable as an additive for aqueous adhesives are known from EP-A 0 206 059.

S DE-A2 557 409 discloses resin acid isocyanates which can be dispersed in water in the presence of nonionic and anionic emulsifiers.

The dispersions or emulsions of carbamoyl sulphonates made from isocyanates and alkali metal and ammonium bisulphites and proposed in DE-A2 839 310 can be employed as sizing agents.

US Patent 4,505,778 discloses bulk and surface sizing agents which comprise mixtures of aromatic polyisocyan-ates containiny 1-10 % by weight of an isocyanate pre-polymer obtained, for exampl~, by reacting aromatic polyisocyanates with monofunctional polyethers.

Furthermore, various polyurethane or polyurea dispersions are known which can be employed as sizing agents. How-e~er, these usually anionic products (cf. German Offen-legungsschrift 2 457 972) do not contain any reactive groups in the form of isocyanate groups. Examples of such products are given in the following documen-ts: FR-Al 496 584, US Patent 3,989,659, DE-A2 537 653, EP-A0 037 379, DE-A3 438 563 and EP-A0 207 414.

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Latices based on diurethanes have also been proposed as sizing agents (cf. EP-A0 232 196).

However, these products are not satisfactory in all respects. In particular, the stability or dispersibility in water is often poor or cationic additives are neces-sary to improve the inherent retention of the resin.
EP-A0 074 544 describes dispersions which contain a disperse phase of l. reinforced resin size and 2.
hydrophobic ketene dimer or hydrophobic isocyanates having at least 12 carbon atoms, where a cationi~ dis-persant (inter alia a polyamide amine-epichlorohydrin resin) is employed to improve the properties.

In addition, it would be advantageous for the user to have an auxiliary which provides the paper with wet and dr~ strength and simultaneou51y also with partial hydro-pho~icity~ i.e~ is suitable as a bulk or surface sizing agent~

There was therefore the object of providing a new process for providing cellulose-containing material with a wet-and dry-strength finish and/or sizing by means of a chlorine-free product which is based on unblocked poly-isocyanates, can be emulsified in water without addition of emulsifiers and achieves the wet-strength action of the polyamidoamine/epichlorohydrin resins when used in a wide pE~ range in pulp and on the surface.

It llas now been found, surprisingly, that Le A 2g 038 _ 5 _ .. . . . . . . . ..... .. . . .
., , . , ., ~ ' , ,,, ~ , - : .

2 ~ '7 9 water-dispersible polyisocyanate mixtures which contain tertiary amino groups, which can also be in the form of their salts, i.e. in protonated or quaternised form, and optionally contain hydrophobic groups and optîonally polyether units, are highly suitable dry- and wet-strength agents for cellulose-containing material and in addition are also suitable as sizing agents i.e. for partial hydrophobisisation of cellulose-containing material, it being possible for them to be used ~efore sheet formation (use in the pulp), that is to say as an addltive to the fibre suspension, or on the sur-face, that is to say as an application to a sheet of paper which has already been formed.~
.

The present invention relates to a process for the lS preparation of cellulose-containing material provided with a dry-strength and wet-strength finish and/or sizedr charac-terised in that the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I~, which contains tertiary amino and/or ammonium groups.

The polyisocyanate mixtures (IJ to be employed according to -the invention optionally contain polyether units and/or hydrophobic groups and/or unmodified polyisocyan-ates.

In a preferred embodiment of the~ process according to the irlvention, the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I)-~Thich Le A 29 038 - 6 -. .

2 ~ 7 ~

contains tertiary amino and/or ammonium groups, option-ally polyether units and/or optionally hydrophobic groups.

In a likewise preferred embodiment of the process accoxd-ing to the invention, the cellulose--containing material is treated with a water-dispersible polyisocyanate mixture (I) which contains tertiary amino and/or ammonium groups and polyether units.

For the purposes of the invention, suitable water-dlsperslble polyisocyanate mixt~res (I) are:

~ Ia) Polyisocyanat~ mixtures comprising 1) polyisocyanates containing tertiary amino and/or ammonium groups, and 2) unmod.ified polyisocyanates E), (Ib) Polyisocyanate mixtures comprising 1) polyisocyanates containing tertiary amino and/or ammonium groups, 2) unmodified polyisocyanates E), 3) polyisocyanates containing tertiary amino ancl/or ~ =~nonium groups and polyether groups, Le A 29 038 _ 7 _ - :
. . . .

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and 4) polyisoeyanates containing polyether qroups, (Ie) ~olyi~ocyanate mixture~ comprising 1) polyisoeyanates eontaining tertiary amino and/or arnmonium groups, 2) unmodified polyisocyanates E), S) polyisoeyanates eontaining tertiary amino and~or ammonium groups and hydrophobie groups, and 6) polyisoeyanates containing hydrophobie groups, , ~Id~ Polyisocyan~te ~ixtures comprising 1) polyisoeyanates eontaining tertiary amino and~or : a~nonium groups, 2) unmodified polyisocyanates h`), : lS 3) polyisocyanates containing tertiary amino and/or ammoni.um groups and polyether groups, 4) polyisocyanates eontaining polyether groups~

.

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2 ~ 9 5) polyisocyana~.es containing tertiary amino and/or ammonium groups and hydrophobic groups, 6) polyisocyanates containing hydrophobic groups, 7) polyisocyanates containing tert;iary amino and/or S ammonium groups, hydrophobic groups and polyether groups, and 8~ polyisocyanates containing polyether grQups ~nd . hydrophohic groups,.

or mixtures of the polyisocyanate mixtures (Ia) to (Id~.

The polyisocyanate mixtures (Ia) and (Id) are part-icularly preferred for sizing and wet- and dry-strength ~ ishing of cellulose-containing material. The polyiso-cyanate mixtures (Ib) are particularly suitable for the wet- and dry-strength finishing of cellulose-containlng material~ ~he polyisocyanate mixtures (Ic) are particu-larly suita~le for the sizing of cellulose-containing material.

For the purposes of this invention, unmodified polyiso-cyanates E~ are taken to mean polyisocyanat~s whi.chcontain exclusively isocyanate groups.

For carrying out the process according to the invention, .

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preference is given to water-dispersible polyisocyanate mixtures II) with a~ a content of isocyanate groups of 10 to 700 milliequivalents per 100 g of rnixture, ~) a mean NCO functionality of 2 l.0, y) a content of ethylene oxide units of from 0 to 30 %
by weight, based on the mixture, with the polyethylene oxide chain as a mean molecular weight (number average) of from 100 to 3500, preferably 10from 100 to lO00, particularly preferably from 100 to 600 g/mol, ~) a content of tertiary amino groups or ammonium groups of from 50 to 5000 mil.liequivalents per 100 g of mixture, and : 15~) a content of hydrophobic radicals of 0-250 milli-: equivalents per 100 g of mixture.

Particular preference is given in the process according to the invention to water-dispersible polyisocyanate mixtures (I) with ~) a content of isocyanate groups of 10 to 300 milliequivalents per 100 g of mixture, an average ~CO functionali.ty of 1.0 to 5, . :
:.

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y) a content of ethylene oxide units of 0-20 ~ by weight, based on the mixture, the polyethy].ene oxide chain as an average molecular weight (number average) of 100 to 3500~ preferab]y lOOtolO00, particularlypreferahly 100 to 600 g~mol, ~) a content of tertiary amino groups or ammonium groups of 50 to 3500 milliequivalents per 100 g of mixture, and ~) a content of hydrophobic radicals of 0~100 milli-equivalents per 100 g of mixture.

In a ~urther pre~erred embodiment, the process according to ~he invention is carried out using water-dispersible polyisocyanate mixtures with ~) a content of isocyanate groups of 47 to S95 milliequivalents, preferably 238 to 476 .. milliequivalents, based on 100 g of mixture, ~) an average NC0 functionality of 1.5 to 4.2 preferably 2.0 to 4.2, : 20 y) a content of ethy.Lene oxide units of 7 to 30 ~ by weight preferably 7 to 20 ~ by weigh-t, based on the mixture, wlleI~in ' ' Le A 29 038 - 11 -'~ ' . , . -:

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the polyethylene oxide chain has an average molecular weight (numher-average) of 100 to 3500, preferably 100 to 1000, particularly pre~erably 100 to 600 g/mol, and ~) a content of tertiary amino groups or a~nonium groups of 1 to 500 milliequivalents preferably 5 to 300 milliequivalents, per 100 g of mixture, The values stated for the NCO functionality of the water-dispersible polyisocyanates to be employed in the process accordiny to the invention relate to the ~alue which can be calculated ~rom the nature and functîonality of the starting components in accordance with the for~ula ; 2 equivalents NCO - .~ equivalents O~l lS f = - __ 2 mol(NCO~OH) - 2 equivalents OH

The content of isocyanate groups is in each case calcu-lated as NCO with a molecular weight of 42 g/mol.

The water-dispersible polyisocyanate mixtures (I) employed for carrying out the process according to the invention are ob-~ainable by reaction, in any desired sequence, of II) (cyclo)aliphatic amines which optionally contain .
' :

~; ~ he A 29 038- 12 -' . , '.' 2 ~ 7 9 ether, ester or amide groups, contain at least one ~roup which is reactive ~owards isocyanates and contain at least one tertiary amino gr~up and/or arnmonium group, or mixtures thereof, with III) unmodified polyisocyanates E), and optionally with IV) C4-C3~-hydrocarbons G) which are straight-chain or branched, saturàted or mono- or polyunsaturated, and ~ 10 contain at least one group which is reactive towards `: isocyanates, and opti.onally with V) polyalkylene oxidc polyether-alcohols F) which optionally contain ester groups, the ratio of equivalents of ~CO groups of component III) : employed to the sum of the groups of compone~ts II), IV) and V) which are reactlve towards isocyanates heing at ~ least 0.1:1 to about 1000:1, preferably 4:1 to about - ' 1000: 1 . ~ `

The water-dispersible poLyisocyanate rnixtures (I) employed for carrying out a fur-ther embodiment of the process according to the invention a~e obtainable by .: :
., ,~:

:
; : Le A 29 038 - 13 -' ":

. . ,: : .

$ 7 9 reacting, in any desired sequence, II) (cyclo)aliphatic amines which optionally contain et~er, ester or amide groups, contain at least one group which is reactive towards isocyanates and contain at least one tertiary amlno group and/or ammonium group, or mixtures thereof, with III) unmodified polyisocyanates E), and with V) polyalkylene oxide polyether-alcohols F) which optio~ally contain ester groups, the ratio of equivalents of NCO ~roups of component III) employed to the sum of the groups of componen~s II) and ~) which are reactive towards isocyanates being at least lS 2:1, preferably 4:1 to about 1000:1.

The water-dispersible polyi.socyanates (I~ employed for carrying out the process according to the invention are preferably obtainable by reaction of II) A) Amines which contain a group which is reactive towards isocyanates, of the formula Le A 29 038 - 14 -. ..

21~8~

A1) Rl Y I -X-~in which \ R2 yl represents -O-, -NH~ or -NR3-, wherein R3 represents methyl or ethyl, Rl and R2 a) independently of one ano-ther represent C1-C4-alkyl or C3-C6-cycloalkyl, b) represent a radical of the formula -(CH-CH-O-)~-CH-C~-O-R6 R~ Rs R4 Rs wherein R4 and R5 independently of one another :~ represent hydrogen or ~ethyl, with the condition that always one of the radicals represents hydrogen, R5 represents methyl or ethyl and a assumes values frorn 0 to 10, or c) represent a C2~C4~alkyl radical, substituted by one or ~lore tertiary amino groups and/or ammonium groups, of the formulae Le A 29 038 - lS -,: ,- .':,, '" - , , ': ~'' : ', '' 21 018 J~ ~

r~6 ~(CI12)q~CH2~t~r R6 (cH2)b-N
\~(c~2)(-cH2-N ~ R6 ~6 or -CH2-C~{2-(CHz3~N N~(CH23(,-CH2-N~,R

where n b assumes values from O to 2, q and t independently of one another assume S values of 1 or 2, ' r and s i.ndependently of one another assume : values from O to 3 and ~: R5 has the aboyementioned meaning, or ' 10d) together with the N atom to which they are bonded form a 5- or 6-membered ring of the formula ~; :
. ~ ~

:

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: ~`H2-CH2 wherein Z represents \0 or / -(CH2-CH2-N~,n-R6 or \
a 1 1 wherein m assumes values from O to 2 and a, R~, Rs and ~RG have Lhe abovementioned meaning, and X represents C2~ to C~O-alkylene, Cs to C~-cyclo-alkylene, a radical of the formula -~CH-CH-O-)a-CH-CH-.;
, : wherein R~, Rs and a have the abovementioned meaning, or a radical of the formula ~, .
. :

' ., .

~ ~ ~e A 29 03~ ~ - 17 -.. . . . . .

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----C H-CH2-(O-CH-c H~)a CH2-(O-CH-CH-)~ N-~
in which 14 Rs 12 a, R~, R5, Rl and R2 have the abovementioned meaning, or A 2) of the formula .
-~(Clt2)p~
ll y2 cl-l N-R
(Clt2)n wherein : y2 represents -O-, -~- or NR3-, wherein R3 has the abovementioned meaning, ;~ n and p independently of one another assume values : : 10 of 1 or 2 and R1 has the abovementioned meaning, or :, :.

:

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A 3) of the formula ~(CH2)~
N N-R
(CH2)~, wherein n, p and R1 have the abovementioned meaning, or A 4) of the formula 2),~
N CH-N
(CH2)" \R2 S wherein n, p, R1 and R2 have the abovementioned meaning, , or B~ amines which contain more than one group which is reactive towards isocyanates and optionally ether and/or ester and/or amide groups and have a molecular wei.ght of less than 10 000 g/mol, . or ~ .

Le A 29 038 - 19 -- , ~ , .

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c) the compounds which are reactive towards iso-cyanates and contain ammonium groups obtained by reaction of ~) or B) by pro-tonation and/or quaternisation, or any desired mixtures of A) to C), with III) a mixture of one or more unmodified polyiso-cyanates E) having -- an average NCO functionality of 2.0 to 8.0, ; preferably 2.0 to 6.0, particularly preferably 2.1 to 4.4 and in particular 2.3 to 4.3, and . ~ .
- a content of isocyanate groups of 10 to 50 % by wei.ght, preferably 19 to 24 % by weight, hased on the mixture III, optionally with :
IV) C~-C~0-hydrocarbons G) which are straight-cha:in or branched, saturated or mono- or polyunsaturated, and contain at least one group which is reacti~e towards isocyanates, and optionally with . ' :
.

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2 ~ 7 9 v) mono- or polyvalent polyalkylene oxide polyether-alcohols F) which contain a s~ati.stical average of 5.0 to 70 ethylene oxide units and optionally con-tain ester groups, in any desired sequence.

Water-dispersible polyisocyanate mixtures (I) with ~) a content of isocyanate groups of 10 to 7Q0, preferably 10 to 300 milliequivalents, per 100 g . of mixture, P) an average ~CO functionality of ~1.0, preferably 1.0 to 5, ;

y) a content of ethylene ox.ide un.its of O to 30 % b~
weight, preferably 0 to 20 % by weight based on the mixture, wherein the polyethylene oxide chain has an average molecular weight ~number-average) of 100 to 3500, ; preferably 100 to 1000, particularly preferably 100 to 600 g/mol~

~) a content of tertiary amino groups or ammonium groups of 50 to 5000, preferably S0 to 3500 rnil1.iequivalents per 100 g of mixture and :

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¢) a content of hydrophobic radicals of 1 to 250 milliequivalents per lO0 ~ of mixture are new and the invention likewise relates to them.
Water-dispersible polyisocyanate mixtures with ~) a content of isocyanate groups 2 to 25 ~ hy weight, preferably 10 to 20 ~ by weight, based on the mixture, an average NCO functionality of 1.5 to 4.2, prefer-ably 2.0 to 4~2, , y) a content of ethylene oxide units of >10 t.o 30 % by weight, based on the mixture, whe.rein the polyethylene oxide chain has an average : molecular weight ~nu~ber average) of 100 to 35ao, preferably 100 to lO00, particulary preferably 100 to 600 g/mol, and ~) a content of tertiary amino groups or ammonium groups of 1 to 500, preferably 5 to 300 milliequiva~
lents per 100 g of mlxture .~
are ne~ and the inventlon likewise relates to them.

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2 ~ 7 9 The invention also relates to the corresponding water-dispersible polyisocyanates obtainable by protonation and/or quaternisation of the abovementioned polyisocyan-ate mixtures according to the invention which contain S tertiary amino groups, alkylating agents, such as, for example, dimethyl sulphate, die-thyl sulphate or C1- to C4-alkyl halides and -sulphonates, being used for the alkylation.

The invention also relates to the aqueous dispersions o~
10- the polyisocyanates according to the invention and the hydrolysis products~ which are contained therein, where appropriate, and contain urea groups, of the water-dis-persible polyisocyanateæ (I~ according to the invention containing tertiary amino groups or ammonium qroups.

The term "water-dispersible" in connection with the polyisocyanate mi~tures (I) means that the mixtures in a concentration of up to 70 % by weight, preferably up to S0 % by weight, give finely divided dispersions in water with particle sizes (ultracentrifuge) of <500 nm.

For the purpose of the present invention, "hydrophobic groups" is taken to mean groups which are derived from C~-C30-hydrocarbons G) which are straight-chain or branched, saturated or mono- or polyolefinically unsatu-rated and contain at least one group which i5 reactive towards isocyanates.

The corresponding water-dispersible polyisocyanate :

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mixtures containing ammonium group~3 obtainable by proton-ation and/or quaternisation of the water-dispersible polyisocyanate mixtures ( I ) to be employed according to the invention are also suitable for carrying out the S process according to the invention. Alkylating agents, such as, for example, dimethyl sulphate, diethyl sulphate or Cl-C~-al lcyl halides and -sulphonates, can bc used for the quaternisation.

Examples of amines II) A) which may be mentioned are: :
N,N-dimethylethylenediamine, N,N-dimethylpropylenedi-amine, dimethylaminohydroxyethane, dimethylaminohydroxy-propane, diethylaminohydroxyethane, dibutylaminohydroxy-ethane, diethylaminoethoxyhydroxyethane,. ~2 diethylamino-ethoxy 3 ethoxyhydroxyethane, N, N ' -triethyl-N ' - [ tl)-hydroxy-tetraethoxyethyl lpropylenediamine, N-hydroxyethyl-mor-pholine, N- hydroxyethyl-methylpiperazine, N-hydroxyethylpiperidine, N-hydroxyethylpyrrolidine, 4-hydroxy-N-me-thylpiperidine, 4-hydroxy-1-dimethylamino-cyclohexane, 1, 3 ~bis ( dimethylamino-ethoxy-ethoxy ) -2 -hydroxypropane, 1,3~bis(dimethylamino-propoxy3-2-hydroxy-propane and the amines of the following formulae:
fH3 (C2Hs)2~ CH~N~{2- (CH~2N-CH2-C-CH2-Nl{2 I

C~13 , _ C ~N ~-CI-{2~ 01-i, CI {3-N~ N ccl l2~ o l-~ 0 N-tC1 12-k OI {

,~
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2101~ 19 C1~3 '~5~2N~cH2t~c~-N~-l2 N-~CI-{2~ N~2-Cl~3 Cl-{3 CH3 A ¦ l l O N-CHz-CH-NH2, (C21~5)NCH2-CH-NH2, ~CH3)2N-CH2-CH-NH2, ~ .
` ~`'/\N~CH2~0H, C~3 \~CH2~N N--~H~OH

C~3 HO-(CH2)6-l~/

:

; CH3 ICH3 "NtCH~3~NH~, N--CH2- CH- NH2 . (CH3)2N-CH2-C-NI{2 C~-l3 ~ C 1-1 3 ~ C2~{5 HO ~CH2)2 N~ 7 HO ~CH2)2--- N
Cl 13 C2l-l5 .`
: .
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1-10--(CH2)2 ---N O . 110--~Cll2)2 N N-CI{3 ~3~ C21-15 HO--(C~12~2--N \ C2l{s wi th An(3 = C1~30S03(~3, Cl(3, Br(~, An~ C~3 ,~/CI~3 HO--(CH2)3 N\ Cl~3CO0(3, .

HO-~ N--CH3 . ~IN N--Cll~

(CH2)2- N ~ 3 HO {CH2)2~N CH3 .
C~-13 /C2f 15 H~O-CH CH2~N\
Cl~ ( Cl~7-Cl f2- ~CH3 Cl ~3 C2Hs HO{Cf {2--Cf~ CH2-- C~-~ N~

: ~ Cl{3 C2H5 with n = l-lO

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C2i-~5 HO--(Ci~2--CH2--0),' CH2--CH2- N
C21-~5 wi th n = I - 10 Cl H3 CH3 (CH2)2--N ~CH2)2 N

HO---(CH2)2----N \ CH3 (CH2)2--N\J~ ~CH2)2--N

:

OH
CH3 \ I /CH3 /N----CH2--CH CH2--N\

C2H5~ IOH ~C2H5 ~, N-CH2-CH-CI{2-N
: ~ ~ C2~{5 C21~5 Ct-~3 C~ , Ol{ Cl-i3 / Cl-~3 /N - Ci-{2- Ci-12 C1-{2 N--C1-12- Cl-l- Cf-12- N--- Cl-{2--Cl 12- Cl-12-Ci-~3 C113 ~[~3 Ci-{3 An3 C1-~3 with .~n(~ = Cl(~, Br~3. CH3OSO3(~) :
~ : :
i ': :

Le A 29 038 - 27 -~, ~
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Cl-l3 Ol-~ Cl~3 N - Cf-~2- Cil2--O--CH2--CH--CH2--O--C~2--Cl~2--N~
C~l3 CH3 r~ I r~

\ /

OH (-NH2, -NHCH3) r~ ~ I r~
CH3 -1`~' N--CH2--CH--CH2--N j~T - CH3 C2Hs ,, N CH2--C~2 OH ~CH2--CH2--L\l ~ C H
Nl--CH7--CH--CH7---N' \ N--CH7--CH2 \CHz- ~H2--~ /
C2H5 ~ C2H5 ' r~
Clt3--N N (C~{2)2 Ol{ Cl-i3 - N--C1-{2---- CH---CH2--N
Cl-~
C~13 3 , :
:

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~ ` . . . .:

Examples of amino-alcohols s) which ~ay be mentioned are:
methyl-bis(2-hydroxyethyl)-amine, methyl-bis(2-hydroxy-propyl)amine, N,N'-bis(2-hydroxyethyl)-N,N'-dimethyl-ethylenediamine, N,N"-bis(2-hydroxyethoxyethyl)-N,N',N"-trimethyl-diethylenetriamine, N,N-dimethylamino-propyl-bis[~-hydroxy-tetraethoxyethyl]amine, triethanolamine, reactlon products of triethanolamine with 3 to 20 mol of ethylene oxide and/or propylene oxide per mol of amine, reaction products of polya~inines, such as aminoethyl-piperazine, triethylenetetramine and bis-(2-aminoethyl)-piperazine, with ethylene oxide and/or propyl~ne oxide, diethylenetriamine-bispropionamide, N,N'-bis-propionyl-aminoethyl-N"'(2-hydroxyethyl)amine and reaction products of tetramethylethylenediamine/dichloroethane condensates with ethyl~ne oxide and/or propylene oxide.

The follow.ing polycondensates, for example, are also ~j su.itable amines II) B):

a) polyesters containing hydroxyl end groups, prepared by condensation o C2- to C8-dicarboxylic acids, polyethylene oxide and/or polypropylene oxide or copolyethers of ethylene oxide and propylene oxide, and dihydroxyalkylamines, preferably N-methyl-di-ethanolamine or N-methyl-diisopropanolamine, having an OH fllnctionality of 2, b) polyesters containing hydroxyl end groups, prepared by condensation of C2- to C8-dicarboxylic acids and thie dihydroxyalkylamines listed under a), having an ;~ .
:
~`
I,e A 29 038 - 29 -21~7~

OEI functionality of 2, c) polyester-amides containin~ hydro~yl end groups or amino end groups, fro~ C2- to C~-dicarboxylic acids, C2- to C6-diaminoalkanes, preferably ethylenediamine, and the dihydroxyalkylamines listed under a), having an O~ functionality of 2, d) polyesters, which contain hydroxyl end groups, from Cz- to C~-dicarboxylic acids, trishydroxyalkanes, preferably trimethylolpropane and reaction products thereof with 1 to 10 mol of ethylene oxide or propylene oxide~, and the dihydroxyalkylamines listed under a), having a ~unctionality of more than 2, e) polyamines containing hydroxyl ~unctional gro~ps, which are obtainable by reaction of am~onium or lineax or branched (poly)alkylenepolyamines, such as, for example, ethylenediamine, diethylenetri-amine, triethylenetetramine or bis(3-aminopropyl)-methyl-amine, a,~-polyether-diamines having a primary or secondary amino group or condensates thereof with less than the equi~alent amount of dihalogenoalkanes, such as dichloroethane, with alkylene oxides, preEerably triethanolamine, tris(2-hydroxypropyl)am.ine, tetrakis(2-hydroxypropyl)-ethylenediamine, .~ ., f) polyamidoamines which contain hydroxyl func~ional groups and are obtainable by reaction of linear or .

:;

Le A 29 03~ _ 30 _ .
', .

2 1 ~

branched polycondensates of C2- to C~-dicarboxylic acids, diamines and polyamines which contain at leas-t three acylatable amino groups, such as diethylenetriamine or triethyle.nete-tramine, and/or polyamines having at least two acylatable amino groups and other tertiary amino groups, such as bis-(3-aminopropyl)-methylamine, and optionally capro-lactam or optionally polyether-diols or polyether-diamines, with alkylene oxides, 1-3 mol of alkylene : 10 oxide being employed per primary and secondary amino group in the polycondensate, g) polyamidoamines according to f) containing hydroxyl functional groups, which contain hydroxyethyl end groups, in the place of the reaction with alkylene lS oxides, and are obtainable by cocondensation ~ith ethanolamine, h) amino alcohols of the formula ; Rs R4 H-(o-lH-lH)~-NR8-~(CH2)d-CH2-CH2-NR7~C-(CH CH-O)c-H (3) ~' .
: wherein R~ and Rs represent hydrogen or methyl, with the condition tha-t always one radical represents hydrogen, Le A 29 038 - 31 -.

.
.

21~87~

R~ and R7 independently of one another represerlt methyl, ethyl or a radical of the formula - ( CHRs-C~R~ O ) f - H or -~CH2-(CH2)q-NRI]hR2, wherein Rl and R2 have the abovementioned meaning and g assumes values from 1 to 6, h represents zero to 4 and R~ and Rs have the abovementioned meaning, k, c and f assume ~alues from 0 to 20, e assumes values from 0 to 3 and d assumes values of 0 or l.
-.
The amines II) B) in general preferably have an average molecular weight of less than 10 000 g~mol. Those having ; an averaye molecular weight of :Less than 5 000 g/mol, in 1 15 particular less than 3 000 gtmol, are paxticularl.y preferred~
.;
Suitable amines II) C) are, for example, the amines which are obtainable by reaction of acids or alkylating agents ~ -with components II) A) or II) B) and in which all or some of the tertiary amino groups have been converted into ammonium groups.

~cids which are suitable for this reaction are, pre~erab-ly, acetic acid, formic acid and ~Cl, and possihle alk lating agents are, ~or example, Cl-C~-alkyl chlorides :
.. ....

~ Le A 29 038 - 32 -i~ .

~ .: . :

. . ~ - :

-' . , ' . ~ , - . ' , , : . : .

2 1 ~ 3 and bromides and dialkyl sulphates, such as dimethyl sulphate or diethyl sulphate.

The polyisocyanates E), which were mentioned in III) and are not modified, are any desired polyisocyanates which are prepared by modification of simple, preferably (cyclo)aliphatic diisocyanates and ha~e a uretdione and/or isocyanurate, urethane and/or allophanate, hiuret or oxadiazine structure, such as are described, for example, in German Offenlegungsschriften 1 670 666, 3 700 209 and 3 900 053 or EP-A 0 336 205 and 0 33g 396 by way of example. Suitable polyisocyanates-E) are also polyisocyanates containing ester groups, for example the tetrakis- and tris-isocyanates accessible by reaction of pentaerythritol silyl ethers or trimethylolpropane silyl ethers wîth isocyanatocaproyl chloride (compare DE~A 3 743 782). It is iurthermore also possib:le to use triisocyanates such as, for example, tris-isocyanatodi-cyclohexylmethane.

Suitable diisocyanates for the preparation of the un-modified polyisocyanates E) are in principle those having a molecular weight range from 140 to 400 and (cyclo)ali-phatically bonded isocyanate groups, such as, for : example, 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexarle, 1,3- and 1,4-diiso-cyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-~ isocyanatomethyl-cyclohexane, 1-isocyanato-1-methyl-4-.~ isocyanatomethyl-cyclohexane and 4,4'-diisocyanatodi-.'' ~:' .
Le A 29 038 _ 33 _ : ' : ,, . : : . . -21 ~ 7 ~

cyclohexyl-methane, or any desired mixtures of such diisocyanates.

The unmodified polyisocyanates E) are preferably polyiso-cyanate mixtures which have an NCO content of 19 to 24 %
S by weight, essentially comprise trimeric 1,6-diiso-cyanatohexane or l-isocyanato-3,3,5-trimethyl-5-iso-cyanatomethyl-cyclohexane and optionally dimeric l,h-diisocyanatohexane or l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane and the corresponding higher homologues and contain isocyanurate groups and ~ptionally uretdione groups. The corresponding polyisocyanates which ha~e the NCO content mentioned, are largely free from uretdione groups and contain isocyanurate groups, such as are obtained by catalytic tximerisation, which is known per se, of 1,6-diisocyanatohexane or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane with .isocyanur-ake ~ormation, and which preferably have an taverage) NCO
functionality of 3.2 to 4.2, are particularly pre~erred as component ~). Preferred components E) are also the trimeric polyisocyanates which have an NCO content of l9 to 24 ~ by weight, are obtained by reaction of 1,6-diisocyanatohexane with a substoichiometric amount of water in a known manner and essentially contain biuret groups.

Other suitable, althoug}l not preferred, polyisocyanates E) are aliphatic or aromatic diisocyanates, such as hexamethylene diisocyanate, toluylene diisocyanate, 1,S-dii.socyanatonaphthalene, diphenylmethane diisocyanate and ~ ' :

Le A 29 038 _ 34 _ . . .

2 ~ 7 ~

higher homologues thereof with uretdione, isocyanurate, allophanate or biuret ~roups and the like.

Hydrocarbons G) are ~ose having 4 to 30 carbon atoms which are straight-chain or branched saturated or mono- or polyunsaturated and containing at least one group which is reactive tc~ards isocyanates. Reactive groups are taken to mean amino, hydroxyl and carboxyl groups. Examples which may be mentioned are tlle following hydrocarbons G):
stearyl alcohol, stearylamine, stearic acid, dodecanol, hexanol, undecanol, 2-ethylhexanol, hexadecylamine, hexadecanol, dehydroabietyl alcohol, behenyl alcohol, behenic acid, oleic~acid, linoleic acid, oleyl alcohol, 7(8)-hydroxy-tricyclo[5.2.1.0263dec~-3(4)-ene, hex~hydro-phthalic acid, ll-hydroxystearic acid and 1-hydroxy-undec-10-ene.

The polyalkylene oxide polyether-alcohols F) which were mentioned in V) are mono- or polyvalent polyalkylene oxide polyether-alcohols which contain a statistical average of 5 to 70, preferably 6 to 60 ethyLene oxide units per molecule, such as are accessible in a known manner by alkoxylation of suitable starter molecules.

Any desired mono- or polyhydric alcohols having a molecu-lar weight range of 32 to 150 g/mol, such as are also used, for example, in accordance with EP-A 0 206 059, can be employed as starter molecules for the preparation of the polyalkylene oxide polyether-alcohols F). Monofunc-tional aliphatic alcohols having 1 to 4 carbon atoms are ~referably used as starter molecules. The use of methanol :
Le A 29 038 - 3s -: .
. . . ,, - , . . .

:, . : . .. . ...

- 2 ~

is particularly preferred.

Alkylene oxides which are suitable for the alkoxylatlon reaction are, in particular, ethylene oxide and propylene oxide, which can be e~ployed in the al.koxylation reac-tion in any desired sequence or also as a mixture.

The polyalkylene oxide polyether-alcohols F) are either pure polyethylene oxide polyethers or mixed polyalkylene oxide polyethers which contain at least one polyether sequence which has at least 5, in general 5 to 70, preferably 6 to 60, and particular]y preferably 7 to 20 ethylene oxide units, the-alkylene oxide units com-prising ethylene oxide uni.ts to the extent of at least 60 mol %, preferably to the extent of at least 70 mol %.

Preferred polyalkylene oxide polyether-alcohols F) are mono~unctional polyalkylene oxide polyethers which have been started on an aliphatic alcohol containing 1 to 4 carbon atoms and which contain a statistical average of 6 to 60 ethylene oxide units. Particularly preferred polyalkylene oxide polyether-alcohols F) are pure poly-~thylene glycol monomethyl ether-alcohols which contain a statistical average of 7 to 20 ethylene oxide units.

Suitable polyalkylene oxide polyethers F) containi.ng ester groups are polyester ethers which contain OH end groups, are obtainahle by reaction of aliphatic C2~ to Cy~
dicarboxylic ac.ids or esters or acid chl.orides thereof with polyethers from the group comprising polyethylene ., :

':~
I.e A 29 038 - 36 -- . ,: , . : .:
, :. . , . ' ': . : .. . ' . .. . .

2~87~

oxides, polypropylene oxides or their mixtures or copoly-ethers thereof, 0~ to 0.99 equivalent of carboxyl groups or derivatives thereof being employed per OH equivalent of the polyether, and have an average molecular weight of less than 10 000 g/mol, prefera~ly less than 3 000 g/mol, and contain hydroxyl end groups.

In the case where the amines or amino-alcohols II A) to II C) contain polyether chains, r~action of A) and/or B) andtor C) with the polyisocyanates E) can also lead directly to water-dispersible polyisocyanates, so that, if appropriate, the content of component F) can be reduced.

The polyisocyanate mixtures (I) to be employed according to the invention can also be employed in combination with external ionic or nonionic emulsiiiers. Such emulsifiers are described, for example, in Methoden der organischen Chemie (Methods of Orga~ic Chemistry), Houben-Weyl, Volume XIV/l, Part 1, page 190-208, Thieme-Verlag, Stuttgart (1961), or in U.S. Patent Specification 3 428 592 or ~P~A 0 013 112. The emulsifiers are employed in an amount which ensures dispersibility.
, If polyisocyanates E) are initially reacted with poly-alkylene oxide polyether-alcohols F), this reaction can be carr.ied out in a manner which is known per se, observ-ing an NCO/OH equivalent ratio of at least 2:1, in general from 4:1 to about l 000:1, polyether-modified polyisocyanates D) being obtained with Le A 29 038 - 37 -, . . . .... .
- .. . . . .

', ' '. ~. ' : ' .. ...

- an average NCO functio~ality of 1.8 to 4.~, prefer-ably 2.0 to 4.0, - a content of ~cyclo)aliphatically bonded isocyanate groups of 12.0 to 21.5 % by weight and 5 - a content o~ ethylene oxide units located within polyether chains (calculated as C2H~O, molecular weight = 44 g/mol) of 2 to 20 % ~y weight, the polyether chains containing a statistical average of 5 to 70 ethylene oxide units.

The reaction of components A) and/or B) and/or C) with components Ej and optionally F) and optionally G, is carried ou-t in any desired sequence with exclusion of moisture, preferably without a solvent. As the amount o alcohol comp~nent employed increases, a higher viscosit~
of the end product is achie~ed, so that in certain cases which are not preferred, (when the viscosity rises, for example, ahove 100 Pas), ~ solvent which is preferably water-miscible but inert towards the polyisocyanate can be added. Suitable solvents are: alkyl ether-acetates, glycol diesters, toluene carboxylic acid esters, acetone, methyl ethyl ketone, tetrahydrofuran and dimethylform-amide. The reaction can be accelerated by co-using catalysts which are known per se, such as dibutyltin dilaurate, tin(II~ octoate or 1,4-diazahicyclo[2,2,2]oc-tane, in amounts of 10 to l 000 ppm, based on the reac-tlOn compo~ents~

: :
' ~ Le A 29 038 ~ 3~ ~
~,' . .

.,. ~

The reaction is carried out in the temperature range up to 130C, preferably in the ranqe between 10C and 100C, particularly preferably between 20C and 80C. The reaction is monitored by titration of -the NCO content or by measurement of the IR spectra and evaluation of the carbonyl band at about 2 100 cm~l, and has ended when the isocyanate content is no more than ~ by weight above the value which is achieved with complete conversion at the given stoichiometry. As a rule, reaction times o~
less than 24 hours are adequate. Solvent-free synthesis of the polyisocyanates to be employed according to the invention is preferred. In an embodiment whLch is not preferreà, it is also possible for the polyisocyanate mixtures to be employed according to the invention to be prepared by mixing 1) unmodified polyisocyanates E)~

2) polyisocyanates which are obtained by reaction of polyisocyan~tes E) with the amines mentioned ;; under I), the ratio of the equivalents of the groups of I~ which are reactive towards isocyanates to the ~CO groups of component II) employed being l:1 to 1: 10~0, and 3) polyisocyanates which are obtained by reaction of polyisocyanates E) with polyallcylene oxide poly-ether-alcohols F), the ratio of the equivalents of :

.

~ re A 29 03i3 _ 39 _ .~

.

187~

the groups of component III 1 which are reactive towards isocyanates to the NCO groups of compon-ent r ) employed heing l:l to l:lO00~

. .
The number of amine equivalents, the polyether content, the NCO content and the NCO functionality here, can be adjusted by the expert, by appropriate weighing, such that the resulting mixture has the necessary composition for water dispersibility, the preferred ranges already mentioned applying.

The water-dispersible polyisocyanate mixtures (I) ~o be employed according to the invention are easy to handle industrially and, wi~h excl~sion of moisture, are stable to storage for months. The polyisocyanates which contain hydrophobic groups are each liquid or wax-like depending on the content of the hydrophobic groups.

The water-dispersible polyisocyanate mixtu~es (I) are preferably employed without organic solvents for carrying out the process according to the invention. They ~re very easy to emulsify in water, if necessary with addition of acids and/or at temperatures of up to 100C. The active compound content of the emulsion can be up to 70 ~ by weight. However, it is ~ore advantageous to prepare emulsions having an active compound con-tent of 1 to 50 %
by weight, which can then be further diluted, if appro-priate, before the metering point. The mixing unitscustomary in industry (stirrers, mixers with the rotor--stator principle and, for example, high pressure .~ :
, ' .

,,:

Le A 29 038 ~ 40 ~ .
. , . ~ , . ...
~, . , , : . . ,:
;

21~ 8~

emulsifyi.l-lcJ macl~ ) are suita~le fOL tlle emulsiication. The preferred polyisocyanates are self-emulsifyirlg, that is to say they can easily be emulsified a~ter addition to the aqueous phase, even wi.thout the action o higll shearing forces. A static rnixer is in general sufficient. The resulting emulsions have a certain processing time, which depends on the structure o~ the polyisocyanates to be employed accordi~g to the invention, in particular on their content of basic N atoms. The processing time of such an aqueous emulsion i.s as a rule up to about 24 hours. The processing time is de~ined as the time within which the optimum dry- and wet-~trength action~or the sizing action is achieved.
.~ ' .
To facilitate incorporation into the aqueous phase, it may be expedient to employ the water-dispersible polyiso-cyanate m:ixture to be employed ,according to-the invention as a solution in a solvent wh.ich is inert towards iso-cyanate groups. Example of suitable so.lvents are ethyl acetate, ethylene glycol diacetate, propylene glycol diacetate, 2-butanone, l-methoxypropyl 2-acetate, toluene and mixtures thereof. The content of solvent in the solutiorl of the polyisocyanate should be not more than 80 ~ by weight, pre~erably not more than 50 ~ by wei~ht.
However, the use according to the invention of solvent-free water-dispersible polyisocyanate mixtures is par-ticlllarly preferred.
;

Cellulose-corltair~ g materials which are suita~le for the proccss accordin~ to th~ invention are, for eYample, ~' ;:

Le A 29 038 - 41 -. , , 21~ ~ 8 l ~

paper or paper-like material, such as paperboard or card.
The finishing treatment is carried o~t i~ a manner which is known per se.

The polyisocyanate mixtures (I3 which are preferred for the wet- and dry-strength finishing have an NC0 functionality of greater than 2 and contain only a small amount of, preferably, from 0 to 100 milliequivalents of hydrophobic radicals per 100 g of polyisocyanate mixture (I). The polyisocyanate mixtures ~I) which are preferred for the production of sized papers optionally contain a higher proportion of, preferably, from 100 to 250 milliequivalents of hydrophobic radicals per 100 g of polyisocyanate mixture (I) and may also have an NC0 functionality oE less than 2.

Polyisocyanate mixtures ~I) which contain terti.ary amino and/or ammonium groups and only a very small proportion of, preferably, clO % by weight of polyether groups and few or no hydrophobic groups based on component G) are pxeferably suitable both as wek-strength, dry-strength and sizing agents.

For carrying out the process according to the invention ; for providing a dry- and wet-strength finish, the water-dispersible polyisocyanate mixtures are employed, for example, in the pulp, that is to say they are added directly to the cellulose-containing dispersion of the fibre raw materials. A procedure is followed here in which the polyisocyanate mixture is emulsified at a ' Le A 29 038 - 42 -.

.
' ' ` : ' ' ' ,: ~
:
.
. .

21gl879 temperature of 20 to 80C in water and the resulting emulsion is added to a suspension of the fibre raw material or is dispersed directly in the suspension of the fibre substances and the paper is formed from this suspension by dewatering, and is subsequently dried. It is expedient to take 1 to 4 times the amount of water for emulsification of the polyisocyanate mixture. Larger quantities of water are also possible.

When employed on the surface, a finished basepaper is treated with an emulsion of the polyisocyanate mixture to be employed according to the invention in water and is then dried. Use in a size press is possible. Tn this case, the polyisocyanate mixture emulsified, as already described, in water is transferred to the finished web of paper. The dry- and wet-strength effect is already achieved immediately after drying. The wet-strength effect which can be achieved by surface treatment con-siderably exceeds the level which can be achieved with the wet-strength agents known to date with the same dosage of active substance.

To achieve the desired effect, it is particularly prefer-able to meter the aqueous emulsion of the polyisocyanate mixtures to be employed according to the invention into the fibre substances in the course of 60 minutes, prefer-ably in the course of 15 minutes. In order to achieve theoptimum wet-strength effect under conditions in practice, it is particularly advisable to meter in the polyisocyan-ate, for example, shortIy before the headbox on the paper Le A 29 038 - 43 _ - ~ . .

~:

- - -8 ~ ~

machinery. Sheets of paper having a w~ight per unit area of 50 to 100 m2/g will in general be formed in the labor-atory for testing.
: ' In water, the NCO groups of the polyisocyanate mixtures S to be employed according to the invention hydrolyse slowly, with evolution of CO2, to give the corresponding amines, which react with some of the NCO groups still present to give urea groups. Advantageously, however, no precipitates occur.

In the process according to the invention, the products can be metered into the fibre substance in the pulp in the pH range between 4 and 10, preferably between 5.5 and 9. Use in the neutral pH range (pH 6 to 7.5) is particularly preferred.

lS In this pEI range, some of the tertiary ~nino groups are present in protonated form. It is also possible to carry out the dispersion with addition of acid. A cationic charge is obtained, regardless of the p~, if the polyiso-cyanates obtained by quaternisation of the tertiary amino groups are employed. However, quaternisation is not necessary for most uses.

; The use amounts of polyisocyanate mixture (I) to be employed accor~ing to the invention depenc~ on the effect sought. As a rule, use amounts of 0.001 to 50 ~ by weight, preferably 0.1 to 10 ~ by weight, par-ticularly preferably 0.1 to 2.0 % by weight of acti~e compound, Le ~ 29 038 ~ 44 ~

.

-' ; : . , . : . -.

. : . .. ',' . ' ', :

based on the dry fibre raw material, are adequate.
Metering in of the active subs~ance, based on the fibre raw material, corresponds to that of the known wet-strength agents of the polyamidoamine/epichlorohydrin type. The polyisocyanate mixtures to be employed accord-ing to the invention result in ready-to-use papers having a good wet strength immediately from the machine~ The wet-strength action can be intensified hy storage of the finished paper and/or af~er-condensation. Genera~ly, however, a higher level o wet strength can alrea~y be achieved from the machine than with conventional wet-strength agents. The dry strength is also improved compared with conventional wet-strength agents.

The process according to the invention is carried out under the processing temperatures customary in the paper industry. The processing time here depends on the temper-i ature. The processing t~me is relatively long in the temperature range from 20 -to 25C~ ~fter storage of the aqueous emulsion for 6 hours, the wet-strength action 2~ still achieves about 70 % of the value obtained if the emulsion i5 used immediately. At a higher temperature, for example at 50C, processing within 6 hours i9 to be recommended. On the other hand, th~ maximum wet-strength action surprisingly depends hardly at all on the contact time with the cellulose. Papers which have been formed immediately and after a contact time of 2 hours after addition of the water-dispersible polyisocyanate mixture to the paper fibre substance in each case show the same wet strength level.

Le A 29 038 ~ 45 ~

: , ~ , , ' ' . : ' : : : .: ' ' ,, 21~:~87~

The strength level of the paper can be ad~usted in the desired manner by suitable choice of the starting compon-ents. The process according to the invention is suitable not only for the preparation of papers having dry strength and strength in water, but also for the prepara-tion of oil- and petrol-resis-tant papers.
.
The water-dispersible polyisocyanate mixtures (I) to be employed according to the invention can be employed in combination with other cationic auxiliaries, such as retention agents, fixing auxiliaries, dry-strength agents and wet-strength agents~ In particular, fixing of fillers can be intensified fùrther ~y addition of commercially available retention agents of the type of cationic polycondensates and polymers, for ex~mple polyamines, lS polyethylenimines, polyamidoamines and polyacrylamides, and the dual systems comprising cationic or cationic and anionic and optionally particulate components, such as silica sols and the like. This is of particular interest if use in the laminated paper sector is intended. Pre-ferred retention agents in the context of the inventionare cationic polycondensates of polyamines, preferably N-methyl-bis(3-aminopropyl)amine, and alkylene dihalides, preferably dichloroethane. ~owever, it should be empha-sised that the desired wet-strength effect can also be achieved withbu~ addition of special fixing agents. In particular, the strenqth of the paper can be increased by combination with polysaccharides, s~ch as hydroxyethyl-cellulose, carboxymethylcellulose, starcll, galactomannans .
Le A 29 038 - 46 -.
'' . , .
' ' ' ' 21~ 79 or c~tionic de~ivatives thereof.

If appropriate, the polyisocyanate mixtures to he em-ployed according to the invention can of course be employed together, that is to say simultaneously or successively, with the abovementioned cationic auxili-aries. However, since many of the auxiliaries contain organically bonded h~logell, combination with AOX-free and/or AOX-low auxiliaries is particularly preferred, since chlorine-free papermaking is the chief aim.

The polyisocyanate mixtures ~I) to be employed according to the invention are readily compatible with customary optical brighteners. ~he products to be employed accord-ing to the invention do not lead to a lowering in the whiteness, and do not influence the absorbency of the paper. Furthermore, a soft handle to the paper can be producecl for use in the hygiene paper sector.

The polycondensates furthermore cause intensification of the sizing action o~ pulp sizing agents, such as reactive sizing agents, for example alk~l ketene dimers, alkenyl-ZO succinic anhydride or dehydroabietyl isocyanate.

The process according to the invention leads to no AOXpollution of papermaking wastewaters. Ly the use accord-ing to the invention of the water-dispersible polyiso-cyanate mixtures, the COD values (COD = chemical oxygen Z5 demand) in the screen ~ater of the paper machinery is considera~ly lower than in the case of nonionic products.
~: :

:

Le A 29 038 . .

2 1 ~

In comparison with processes which employ AOX-low prod-ucts, the wet-strength requirements are met with consid-erably lower concentrations o~ ionic groups, at a corres-ponding NCO functionality, in the process according to the in~ention. The retention of fillers is likewise improved.

In contrast to polyamidoamine/epichlorohydrin wet-strength agents, the maximum wet strength which is also achieved when the agents are employed in the pulp can also be achieved when the agents are employe~ on the surface.

Another advantage of the process according to the inven-tion is that the wet strength is achieved directly ~rom the paper machinery. In contrast to the prior art, after-maturing of the paper or after-condensation - as is customary, for example, with polyamidoamine/epichloro-hydrin resins - is not necessary.

~ In order to carry out the process according to the ;~ invention for the production of sized papers, the water-dispersible polyisocyanate mixtures (1) are employed, for example, in bulk or in the surface. The application form thus corresponds to the procedure described under wet-strength and dry-strength finishing. Good immediate sizing directly after sheet formation is ohtained and can be further increased by post-condensation; in particular, the sizing acti~n can readily be stepped via the metering Le A 29 038 - 4~ ~

2 ~ 7 ~1 In the following exa~ples, the percentage data relate to percentages by weight, unless stat~d otherwise.

Preparation of the raw ~dterials Polyisoc-yanate (lL

87 g of a polyisocyanate which is prepared by trimerisa-tion of some of the isocyanate groups of 1,6-diisocyan-atohexane, contains isocyanurate groups, essentially comprises tris(6-isocyanatohexyl.) isocyanurate and higher homologues thereof and has an NCO content of 21~4 ~, a content of monomeric 1,6-diisocyanatoh&xane of ~0.3 ~ and a viscosity of 3 000 mPas (230Cj (NCO functionality about 4.0) are reacted with 13 g o a polyether which has been started from 2-(2~methoxyethoxy)ethanol, is based on ethylene oxide and has a number-average molecular weight of 350 g/mol and a hydroxyl num~er of 160 mg of KOH/g.

NCO cont~nt: 17.20 %
Viscosity (23"C): 3 200 mPas NCO functionality: about 3.5.

Polyisocyanate (2) 150 g o a polyisocyanate which is prepared by tri.merisa-tiOII of sorne o~ the isocyanate groups of l,6-dii.socyan-atohexane, contains isocyanurate grollps, essentially comprises tris(6-isocyanatohexyl) isocyanurate and higher homologues thereof and has an NCO content of 21.4 ~, a : .
' Le .-~ 29 038 ~ 49 ~
.

- , . . . : . . : :
. . , : . .. . .
,'' ~ . .

2~ ~87~

content of monomeric 1,6-diisocyanatohexane o~ <0.3 % and a viscosity of 3 000 mPas (23C) (NCO functionality about 4) is reacted with 35.4 g of an ,~-dihydroxy-poly(oxyethylene) which has a number-average molecular S weight of 400 g/mol and a hydroxyl :number of 280 mg of KOH/g.

NCO content: 13.3 NCO functionality: about 3Ø

Polyisocyanate (3) 201.9 g of a mixture of dimeric and trimeric 1,6-diiso-cyanatohexane, which essentially comprises a mixture of bis(~-isocyanatohexyl)~uretdione and tris(6-isocyanato-hexyl) isocyanurate (viscosity (23C): 150 mPas, NCO
content: 21.6 %, NCO functionality: about 2.3 to 2.5J are reacted with 17~7 g of an a,~-dihydroxypoly(oxyethylene3 having a number-average molecular weight of 400 g/mol and ~: a hydroxyl number of 280 mg of KOH/g.

NCO content: 16.6 %
NCO functionality: about 2.3.

P.olyisocyanate (4) 90 ~ of a mixture of dimeric and trimeric 1,6-diisocyan-atohexane, which essentially comprises a mixture of ; bis(6-isocyanatohexyl)-uretdione and tris(6-isocyanato-hexyl) isocyanurate (viscosity (23C): 150 mPas, NCO
: :
: : .

., Le A 29 038 _ 50 :`

:

content: 21.6 ~, NCO functionality: about 2.3 to 2.5) i~
reacted with 10 g of ~he polyether employed for the preparation of polyisocyanate (1).

NCO content: 18.6 %
Viscosi-ty (23C): 540 mPas NCO functionality: about 2.2.

Polyisocyanate (5) 85 g of a polyisocyanate essentially comprising tris(6-isocyanatohexyl) isocyanurate and having an NCO content of 22.5 ~ and a ~iscosity of 800 mPas is reacted with 15 g of the polyether employed for the preparation of polyisocyanate (1~.

NCO content: 16.9 %
Viscosity (23C): 1 560 mPas NCO functionality: about 3.2.
;

Polyisocyanate (6) 87 g of a mixed dimer of 80 % of 1,6-diisocyanatohexane and 20 % of 1-isocyanato-3,3,5--trimethyl 5-isocyanato-methylcyclohexane are reacted wi.th 13 g of the polyether employed for the preparatîon of polyisocyanate (1~.
:: ' : NCO content: 15.6 ~
Viscosity (23C): 950 mPas NCO functionalit~: about 2.2.

::
,~ '.
- .

Le A 29 038 51 -. . ~
-, ~. : :

2 1 01~79 Polyisocyanate (7~

87 g of a mixed dimer of 65 % of 1,6-diisocyanatohexane and 35 % of 1-isocyanato-3,3,5-trimethyl-5-isocyanato-methyl-eyclohexane are reacted with 13 g of the polyether employed for the preparation of polyisocyanate (1).

NCO eontent: 14.4 %
Viscosity (23C): 5 900 mPas NCO functionality: about 2.2.

Polyisocyanate 18) .
83 g of a polyisoeyanate whieh is prepared by trimer-isation of some of the isoeyanate groups of l,6-diiso-eyanatohexane, eontains isoeyanurate groups, essentially eoMprises tris(6-isoeyanatohexyl) isoeyanurate and higher homologues thereof and has an NCO content of 21.4 ~, a eontent of monomerie 1,6-diisoeyanatohexane of <0.3 % and a viseosity of 3 000 mPas (23C) (NCO functionality about 4.0) are reaeted with 17 g of a polyether whieh has been started from 2-(2-methoxyethoxy)ethanol, is based on ethylene oxide and has a number-average moleeular weight of 350 g/mol and a hydroxyl number of 160 mg of KOH~g.

NCO eontent: 14.9 ~
Viscosity (23C): 5 300 mPas NCO funetionality: about 3.2.

. .

Le A 29 038 - 52 -.

2 1 ~

~?~ b~ a 90 g of a polyisocyanate whieh is prepared by trimerisa-tion of some of the isocyanate groups of 1,6-diisoeyan-atohexane contains isocyanurate groups, essentially comprises tris(6-isocyanatohexyl) isocyanurate and higher homologues thereof and has an NCO content of 21.4 %, a content of monomeric 1,6-diisocyanatohexane of <0.3 ~ and a viscosity of 3 000 mPas (23C) (NCO functionality about 4.0) are reacted with 10 g of a polyether which has : 10 been started from trimethylolpropane, is based on ethyl-ene oxide/propylene oxide in a weight ratio of 85/25 and has a number-average molecular weight of abou~
1 180 g/mol, a hydroxyl number of 9S~7 mg of XOH/g and an average OH functionality of 2 (viseosity ~25C) 250 mPas).

NCO eontent: 18.2 ~
:~ Viscosity (23C): 7 524 mPas NCO functionality: about 3.7.
.~ '.
Polyisocyanate (10~ -The polyisocyanate is identical to the trimer of 1,6-diisocyanatohexane employed for the preparation of polyisocyanate (1).

Preparat _r _ f_ the water-dispersible po yisocYanate mixtures , .
, :

Le ~ 29 038 _ 53 - - ~ . : , . - : : . . . :

,. ..
, . , . . .; . .. . ..

~187~

x~

12 g of 1,2-bis(dimethylamino)-2-hydr~xypropane (0.082 equivalent of OH) are added dropwise to 100 g of polyisocyanate (1) (0.41 equivalent of NCO) at 30C in the course of 30 minutes, while stirring~ 0.5 ~ by weight of dibutyltin (II) dilaurate were added to the polyiso-cyanate at the start of the reaction. The mixture is heated to 40C and kept at this ~emperature for 12 hours~
After cooling, a clear, colourless oil which can be dispersed in water by gentle stirring with a spatula is obtained. The product has the following properties:
.
NCO content: 11.6 ~ ~
Viscosity (23C): about 70 OGO l~as -NCO functionality: about 2.8.

Examples 2 to 24 .
Examples 2 to 24 were carried out in accordance with Example l. The experimental conditions are su~marised in the following Table l.

Definition of the abbreviations:
BDMAHP = 1,3-bis(dimethylamino)-2-hydroxyprcDane DMAEHE = 1-(2-dimethylamino-ethoxy)-2-hydro~:vethane D~AHE = dibutylamino-hydroxyethane DEAHE = diethylamino-hydroxyethane (= diethylamino-ethanol) MDEA = N-methyl-diethanolamine . ~

Le A 2~ 038 - 54 -TE~6EO = triethanolamine + 6 mol EO
PEO350 = polyethylene ~lycol monomethyl ether (M = 350 g/mol ) TMAHP = 1-trimethylammonium 3-hydroxypropane-methylsulphate Ads400 = polyester-ether-diol from 1.05 mol of poly-ethylene glycol 400 and 1.00 mol of adipic acid DM~AP = 1-dimethylamino-3-amino-propane Le A 29 038 - 55 -... : : - . . - .. , . . - , .. ' : ' '.. ' ' - " ... : .' . '. ,: ~ :. ~ ' : : . - , ' "', ~ ' , , ~ . ' ,' .
. .
:, ....

2~ g79 c ~2 ~ o ~ n -- r ~ n ~1 ~n ~
"

O _ .o ~ ~n ~ on ~ ~ ~ o ~r ~ co co o P~ o _ _ _ _ _ _ _ _ _ .~ _ _ _ _ ~ _ _ l ~
d ~ ~
d ,~ CO CC) CO CO ~o o co ~o Z ~ U ~I C`~ ~ C~ ~2C~2 ~2 ~2 ~`J C~ 2 r _ ~ ~~

,, _ ~C ~ I _ a, c~
r o o _ I ~ I I I I _ o :~ o, o o 0 3 0 0 0 ~ O O O O O ~ 0 ~ 0 ~ a ~ OO~D~ca~ c~2coo~2o<D O nO
2 ~ D cn _4 co ~o ~ 2 O
._ ~ ~2 ~ ~ ~ ~ rq ~D ~2 u~ ~ 0 ~07 ~ 2 o o ~ o 'n n ~r o lt2 2 2 u~o oo - ~ o o n n on o o c0 o n o ol ~n 0 D D DO V ~ ~ 21 C C D ~ ~, C -- C

I o o O O O O ~ ~ -~ o O '`

o 41 a. ~ -- _ _ _ _ _ c~2 c~
a ~ a ~ ~ ~ 3 a ~ ~ a ~ a ~
o -- ~ ~ ~ ~n <o r~ 0 cn o -- c~ co ~ :
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c ~L1 1~ o C~ '~ '~ ` ~ ~_~
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L~ LJ_, cn CU CU ~ o~

L. .1 L~ UL) Ll.~ ~)LYI ~ c~ h L~ 1 ~1 ~> 4 C
O ~ CU, C._OD1~ In CD O O 1--; ~ ~ X L3 "r~ ~ L~ <~- < I` a~

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L-~ V _r ~L''~ V O O O O _. O h o o o o o p.

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(~ IU, .
c~ ~X L O ~n co~ ~ c~l ~U C~l _ _ Le A 29 03~3 ~ 57 ~
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Use Examples Use Example I

A mixture of 80 % of bleached pine sulphate pulp and 20 ~
of bleached birch sulphate pulp is heaten at a consist-ency of 2.5 % in a Hollander to a Schopper-Riegler freeness of 38. 100 g of this pulp are introd~ced into a glass beaker and diluted to 1 000 ml with water.

0.3 % by weight, 0.6 % by weight and 0.9 % by weight of active substance, ba~ed on the fibre substance, from the prcducts prepared according to the examples are added to the pulp suspension, after prior dispersion in water (emulsions containing 2a % by weight of polyisocyanate).

After a stirring time of 3 minu-tes, shee-ts of paper having ~ weight per unit area of about ~0 m2/g are formed on a sheet-forming machine ~Rapid-Kothen unit) with the contents of the glass beaker. The sheets of paper are dried at 8SC under a vacuum of 20 mm ~g for 8 minutes and after-heated at 110C in a drying ca~inet for a further 10 minutes.

.
After the conditioning, 5 test strips 1.5 cm wide are cut out of each sheet of paper and i~mersed in distilled water for 5 minutes. Thereafter, the wet strips are immediately tested for their wet brea~ing load in a tensile t.ester.

Le A 29 038 - 58 -~,:: ' , ............... .
,,, :, . : ~ ' .: . : ' ' .- . - . :

:. : . . .

2 :1~18 7 9 The test results are summarised in Table 20 T le 2 Wet breaking loads when used in the pulp, after condensa-tion at 110C (10 minutes) Use Isocyanate Solids Viscosity Wetbreaking load [Nj at an Example acco~ding content lmPas] a~ount of active substance No. to example [%~ used of 0.3 ~ 0.6 ~ 0.9 X-1 1 100 highly 9.6 16.0 18.g ` viscous I-2 2- 100 3~000 3.4 5.7 7.6 I-3 3 100 hIghly 1.7 2.9 3.9 viscous ~ 4 100 745~ 11.7 15.6 17.~
I-5 5 100 74.50 5.8 9.1 10.8 I-6 6 100 11760 6.9 10.0 13.
I-7 7 100 ~0760 13.1 15.4 17.8 I-8 12 100 3010 15.9 23.1 25.9 I-9 14 100 6130 11.7 18.4 24.3 I-10 19 lOd 88S0 4.5 7.0 8.9 I-11 20 100 11230 8.0 19.4 23.5 I-12 23 100 4280 11.5 14.3 17.7 . .
Use Lxample II

Papers having a weight per unit area of 80 g/m2 were produced fr~m 80 % of softwood pulp and 20 % of hardwood pulp with an SR freeness of 35 at pH 7 without a wet-s-trength agent. The papers were finished on a laboratory size press from Mathis, Zurich, Switzerland, type E~E'~ A
solution c~r emulsion which contained 0. 3 %~ 0.75 96 and 1.2 % of the water-dispersi~le polyisocyanates was :
:

Le A :29 038 _ 59 _ .
~ .
.

' ~

employed as the liquor.

The wet uptake of the paper was 100 %. The papers were dri.ed at 85C for 8 minutes. Some of the papers were additionally subjected to condensation at 110C for 10 minutes; for comparison, a known polyamidoamine resin and the nonionic polyisocyanate (1~ were also tested~ The wet breaking load was measured on the sheets of paper analogously to Use Example I.

The results show, surprisingly, that the paper obtained by the process according to the invention already results in a considerably higher we-t strength in the non-con-densed form than when the cor~ercially available poly-amidoamine resin is used, and with after-condensation is ~ar superior to the polyamidoamine resin.

The example rnoreover shows the positive e~fect o~ the polyisocyanate to be employed according to the invention compared with the nonionic polyisocyanate (1).
.

Le A 29 038 60 , :' ' .
,' , ~ . : , 2 ~

~ble 3: Use on the surface (size press) Ex. Product Wet breaking load ~N] Wet breaking load [Nl No~ non-condensed at an condensed at an amount amount of active of active co~pound in ~ompound in the paper the paper of : of 0.3 ~0.75 ~1.2 % 0.3 ~ 0.75 ~ 1.2 %
II-1 polyamido-2.9 5.7 4.2 7.8 11.1 13.0 amine resLn (according to Ex. 3a of U.S. Patent Speci~ication 48 57 586) : 15II-2 polyisocy&n- 5.3 ~.S 7.4 i4.0 15.7 ~1.7 ate (1~ ~ .
3 according to 8.2 10.9 13.6 15.3 20.0 24.0 Example 12 II-4 according to 7.0 10.8 12.8 13.5 19.9 22.5 Exampl~ 24 Use Exam~le III

Analogously to Use Example I, sheets of paper were first produced using the wet-strenqth agent in the pulp. The papers were dried at 85C for 8 minutes. Some of the papers were additionally sub~ected to condensation a-t 110C for 10 minutes. A known polyamide resin and the nonionic polyisocyanate (1) were also tested for compar-ison. The wet breaking load was measured on the sheets of paper analoqously to Use E~ample I.

Le A 29 038 - 61 -'~' ;. , ~ '. ' ' ~; ~, , : . .
.

2 l ~18 19 The results show, surprisingly, that the p~per obtained by the process according to the in~ention already han a considerably higher wet strength~ even in the non-con-densed state, than the paper ohtained using the know polyamidoamine resin and the ~onionic polyisocyanate (].).
With post-condensation, the values of th~ polyamidoamine resin are reached. The polyisocyanates according to the invention moreover also result in considerably higher wet strength values with after-condensation compared with the nonionic polyisocyanate (1).
Table 4: Use in the pulp Ex. Product IJet brea~ing load [~ Uet breaking loac. [~1]
No. non-condensed at an condensed at an amoun~ :
amount of active of active compound in co~pound in the paper the paper of of 0.3 % 0.75 Z 1.2 % 0.3 Z 0.75 % 1.2X
III-l polya~ido- 4.0 8.4 10.19~514.9 17.5 amine resin (according to Ex. 3a of U.S. Patent Specification 48 57 5~6) III-2 polyisocyan- 2.6 4.2 4.74.06.5 7.3 ate (1) III 3 according to 4.6 9.912.36.6 12.8 15.8 Example 12 III-4 according to 6.$ ]Ø0 12.69.513.9 1.8.7 Example 24 Le A 29 038 - 62 -,, . : ' . . . , : :
- . , , . -:: . .,: ' . ' ' :

2~g~9 use Exampl.e IV

Analogously to Use Example I, sheets of paper were formed with amounts of active compound used of 0.45 % and 0.9 ~, based on absolutely dry pulp. Compared with Use Example 1, however, the following changes were made:

a) The polyisocyanate emulsified in water (concentra-tion 2 ~) was added to the pulp suspension only after a certain residence time, and the sheet of paper was then formed immediately.

h) In another series, the polyisocyanate was added to the pulp suspension i~ediate]y as an aqueous emul-sion (concentration 2 ~), sheet formation takin~
place only after a certa.in contact time with the cellulose.

.~
;

Le A 29 038 - 63 -~
.

.
' . , ' ' ' - .

: ~ . , .. :

2 1 ~ 9 Tahle 5: Influence of the standing time in water ~nd i~f:Luence of the contact ti~e with cellulose Ex. Product Wet breaking load Wet brealcing load [N]
IN] after a contact after a standing time S time with the pulp in water [Illinutes~
~minutes] ~series b)] ~series a)]
Amount used: l 5 15 120 0 60 120 360 0.45 % of active compound _ IV-l polyamido-11.311.713.611.711.711.912.2 13.2 :
amine resin~) IV-2 polyiso- 3.7 5.4 -6.65.4 5.4 5.3 5.5 4.7 cyanate ~
IV-3 according11.110.711.210.710.~11.811.8 7.].
to Ex. 24 ... ... _ _ Amount used:
0.9 % of 2 5 active compound . . _ _ . _ _ _ _ IV-4 polyamido-15.016.516.216.516.517.417.916.6 amine resin~) IV-5 Polyiso- 5.37.0 9.5 7.07.0 7.66.96.8 cyanate (1~
_ _ IV-6 according13.113.812.513.813.814.815.58.5 to Ex. 24 ) according to Example 3a of U.S. Patent 3p-cilication 4 B57 566 Le ~ 29 038 - 64 -.

21~879 Example 25 94.25 parts of a polyisocyanate containing isocyanurate groups which has been prepared by trimerisation of some of the isocyanate groups by 1,6-diisocyanatohexane and which essentially comprises tris(6-isocyanatohexyl) isocyanurate and higher homologues thereof and has an NCO
content of 21.9 ~, a monomeric 1,6-diisocyanatohexane content of <0.3 % and a viscosity of 3000 mPas (23C) ~NCO functionality about 4.0) is reacted with 5.75 parts of N,N-diethylaminoethanol (DEAXE). The muxture is stirred at 60C for 6 hours with exclusion of moisture.

NCO content 18.66 %
Viscosity (23C~: 5310 mPas ~.

Examples_26 to 29 Examples 26 to 29 were carried out in accordance with Example 25. The experimental conditions for Examples 25 to 29 are shown in Table 6 below.

:' I.e A 29 038 - 65 -~' .

.

Table 6 _ _ _ .
Example 5OLxenL I~oc. Iuoc ~HE ' ~E NCo NCO
N o ~ ~ g ] l m o l l I q l [ m o l 1 r e c t . o n t n t [ ~ 1 calo . 1~ I
_ _ _ ncnn 9~.25 ~.~91~ 5.75 o o~gl 18 ~ 1~ 6 26 non~ 89.13 0.~6~7 10.~7 0 0929 15 5 15.6 27 ncne 8~ 53 0. ~407 15 47 0.1332 13 9 13 28 nonc 96.95 0.5055 ~ .05 0.026 20.3 20.1 29 acetone 89.1 0.465 21.3 0.0929 6.5 14.1 /5.0 . * Calculated for 100 % of active substance - ~
Example 30 parts of the polyisocyanate from Example 26 are reacted with 2.9 parts of d.imethyl sulphate in 25 parts of acetone. The mixture is stirred at room temperature for 18 hours.

Content of the solution: 47 %
NCO content 7.3 % of solution Viscosity (23C):12,330 mPas (100 ~) .~
; Example 31 85.0 parts of a polyisocyanate containing isocyanurate groups which has been prepared by trimerisation of some of the isocyanate groups by 1,6-diisocyanatohexane and which essentially comprises tris(6-isocyanatohexyl) ', Le A 29 038 - 66 --., , : , : - . : :

:: . - . : , : . ~ ., . . . :

isocyanurate and higher homologues thereof and has an NC0 content of 21.9 %, a monomeric 1,6-diisocyanatohexane content of <0.3 % and a viscosity of 3000 ~Pas (23C) (NC0 functionality a~out 4.0) are reacted with lS.0 parts S of N,N-diethylaminoethanol and 10 parts of N-methylstearyl-amine. The mixture is stirred ~t 60C for 6 hours with exclusion of moisture.

NC0 content 11.0 % (calc.: 10.9 %) Viscosity (23C): 22,380 ~Pas Pol~isocyanate 32 lO0 parts of an ester group-containing polyisocyanate obtained in accordance with ~xample 2 of DE-A3 743 782 by reaction of tetrakis(trimethylsilyloxymethyl)methane with 5-isocyanatocaproyl chloride in a molar ratio of 1:4, having an NC0 cont~n~ of 23.7 ~ and a viscosity of 252 mPas (23C) (NC0 functionality 4.0) are reacted with 16.5 parts of N, N-dimethylaminoetharlol~ The isocyanate is then stirred at 60C for 6 hours with exclusion o~
moisture.

NC0 Content: 14.6 %
Viscosity (23C): 1290 mPas NC0 functionality: about 3.0 ; Polyisocy~anate 33 100 parts of an ester group-oonta1ning polyisocyanate :

Le A 29 038 ~ ~7 ~

' ' ' :

-.
- ~ , 7~

obtained in accordance with Example 2 of DE-A3 743 782 by reaction of tetrakis(trimethylsilyloxymethyl)methane with 5-isocyanatocaproyl chloride in a molar ratio of 1:4, having an NC0 content o 23.7 ~ and a viscosity of 252 r~as (23C~ (~C0 functionality 4.0) are reacted with 33.0 parts of Nt N-dimethylaminoethanol. The isocyanate is then stirred at 60C for 6 hours with exclusion of moisture.

NC0 Content: 8.4 %
Viscosity (23~C): 4180 r~as NC0 functionality: about 2.0 Polyisocyanate 34 78 parts of the polyisocyanate from Example 33 are reacted with 11.8 parts of dimethyl sulphate in 89.8 parts of 1,2-diacetoxypropane. The mixture is stirred at room temperature for 1~ hoursO

Content of the solution: 50 %
NC0 content: 3.65 % (solution) NC0 functionality: a~o~t 2.0 Us~ Example V: Use as wet-strength agent for paper A mixture of 80 % of bleached pine suiphate pulp and 20 ~
of bleached birch sulphate pulp is beaten at a consist-ency of ~.5 % in a Hollander to a Schopper-Riegler freeness of 38~. 100 q of this pulp are introduced into :~ Le A 2~ 038 - 68 -,~, .

: . ~ ' - . - . . ., : . . , , :

2 :L ~18 7 ~

a glass beaker and di~uted to 1000 ml with water.

The prespecified amount of polyisocyanates (active sub-stance, based on fibre substance) are added to the pulp suspension, after prior dispersion in water or in weakly acidic solution (pH 4) (emulsions containing 10 ~ by weight of polyisocyanate).

After a stirring time of 3 minutes, sheets of paper having a weight per unit area of about 80 m2/g are formed on a sheet-forming machine ~Rapid-~othen unit) with the contents of the glass beakers. The sheets of paper are dried at 85C under`a vacuum of 20 mm Hg for 8 minutes and after-heated at 110C in a drying cabinet for a further 10 minutes.
.
After the conditioning, 5 test strips 1.5 cm wide are cut out of each sheet of paper and immersed in distilled water for 5 minutes~ Thereafter, the wet strips are immediately tested for their wet breaking load in a tensile tester.
.` :
~ The t~st results are su_ arlsed l~ Table 7.

.

: :
:
;
Le A 29 038 - 69 -,, :
:' :

2 ~ 7 ~

Table 7a Wet breaking loads when used in the pulp, after condensa-tion at 110C (10 minutes) _ . . ._ ~
EXIQP10 solido Yi~co~lty Wot bre~king l~d tNI
No. content lmPa~l at an ~ou~t of active l~l uubst~nc~ uaod of _ ___ ___ O.~ ~ 0.~ 1 .~ ~-100 5310 8.6 13.1 15.7 26 100 llaO09.9 15.3 18.2 27 100 145308.4 1~.6 15.9 28 100 4570 5.2 7.9 9.2 0 29 35.3 not d~t.13.6 19.6 2Z.7 lO0 1233012.8 22.1 22.6 31 10~ 223809.3 14.0 17.1 ___ - _._ . .__ Table 7b Wet breaking loads when used .in the pulp, after condensa-tion at 110C (10 minutes) _ __ .. _ Ex~mple Solid~ Vi~oo~ity Wot br~king lo~d [Nj No. contont ¦~Pa~ at an a~ou~t of active i ~1 = c~ u~ed ~' _ _ _ 0.4 t O.R ~ 1.2 32 100 129014.5 22.7 24.0 ~3 100 ~1808.1 7.7 8.4 34 50 not d~t.~.5 6.7 10.1 ~ IJse Example VI: Use as a pulp sizing agent for paper `:
The prespecified amount o~ the active compound .
' :

Le A 29 03~ : - 70 -.
., ~ .
: ' , : ' -' '. ' , ~ .. . : . . :, 2 ~ 7 ~

polyisocyanate is added with stirring to a 0.35 ~ aqueous mixture of 50 parts of bleached softwood pulp and 50 parts of bleached hardwood pulp containing 25 ~ of calcium carbonate, based on fibre substance. The polyiso-cyanate is emulsified in water in advance in the mannerdescribed above. The substance system has a pH of from 7 to 7.5.

After a short residence time (from 10 to 20 seconds), a sheet of paper is formed on a laboratory sheet former.
This sheet is pressed out between felts and then dried for 10 minutes at 90C in a drying cylinder. Sheets of paper having a weight per unit area of 30 g/m2 are obtained.
:: :
The action is tested by means of the Cobb test: in 15 accordance with DIN 53132, the water absorption of a paper on one side in a test time of 60 seconds is used to assess the sizing action.

The test results are shown in Table 8.

:' ~' , ~ Le A 29 038 - 71 -::: :: :: : :

:

- . . .

~, , . ~ ' ' .
:: ' :
, 8~

Table ~

Use in pulp sizing Polyiso- cobb60 value of the sample for an active compound cyanate use in an amount of 5 of Example . __ 0.3 ~ o.s % 0.6 ~ o.s ~ l.o ~ 1.2 ~ 2.0 _ 26 >80 78.4 23.4 24.4 29 >80 30.4 21.8 20.8 >80 >80 37.0 27.8 ~ >1~ 24.s 2l.4 , .; .
. : :
. .
( Le A 29 038 - 72 -... , . . :: . : :. ~ . : , - , .~; . . , . ~ - : . : -. ,. . . . . : :: - .. - : : :. . :: ., . . . : , , : . , ,:,: ., :- ~
.: ; ' ' . ' , . , : ' . ' . . : '' ' .,: ' ' ' ' ~ . .
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Claims

1. A Process for the preparation of cellulose-containing material provided with a dry-strength and wet-strength finish and/or sized, in which the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I) which contains tertiary amino and/or ammonium groups.

2. The Process according to Claim 1, in which the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I) which contains tertiary amino and/or ammonium groups, optionally polyether units and/or optionally hydrophobic groups.

3. The Process according to Claim 1, in which the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I) which contains tertiary amino and/or ammonium groups and polyether units.

4. The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures (I) with .alpha.) a content of isocyanate groups of 10 to 700 milliequivalents per 100 g of mixture, .beta.) a mean NCO functionality of ? 1.0, .gamma.) a content of ethylene oxide units of from 0 to 30 %
by weight, based on the mixture, with the polyethylene oxide chain as a mean molecular weight (number average) of from 100 to 3500, preferably from 100 to 1000, particularly preferably from 100 to 600 g/mol, .delta.) a content of tertiary amino groups or ammonium groups of from 50 to 5000 milliequivalents per 100 g of mixture, and .epsilon.) a content of hydrophobic radicals of 0-250 milli-equivalents per 100 g of mixture, are employed.

5.The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures (I) are employed with .alpha.) a content of isocyanate groups of 10 to 300 milliequivalents per 100 g of mixture, .beta.) an average NCO functionality of 1.0 to 5, .gamma.) a content of ethylene oxide units of 0 to 20 % by weight, based on the mixture, wherein the polyethylene oxide chain has an average molecular weight (number average) of 100 to 3500, preferably 100 to 1000, particularly preferably 100 to 600 g/mol, .delta.) a content of tertiary amino groups or ammonium groups of 50 to 3500 milliequivalents per 100 g of mixture, and .epsilon.) a content of hydrophobic radicals of 0-100 milli-equivalents per 100 g of mixture.

6. The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures (I) with .alpha.) a content of isocyanate groups of 47 to 595 milliequivalents, based on 100 g of mixture, .beta.) an average NCO functionality of 1.5 to 4.2, .gamma.) a content of ethylene oxide units of 7 to 30 % by weight, based on the mixture, wherein the polyethylene oxide chain has an average molecular weight (number average) of 100 to 3500, preferably 100 to 1000, particularly preferably 100 to 600 g/mol, and .delta.) a content of tertiary amino groups or ammonium groups of 1 to 500 milliequivalents per 100 g of mixture, are employed.

7. The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures with .alpha.) a content of isocyanate groups of 238 to 476 milliequivalents, based on 100 g of mixture, .beta.) an average NCO functionality of 2.0 to 4.2, .gamma.) a content of ethylene oxide units of 7 to 20 % by weight, based on the mixture, wherein the polyethylene oxide chain has an average molecular weight (number average) of 100 to 600 g/mol, and .delta.) a content of tertiary amino groups or ammonium groups of 5 to 300 milliequivalents per 100 g of mixture, are employed.

8. The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures (I) which are obtained by reaction, in any desired sequence, of II) (cyclo)aliphatic amines which optionally con-tain ether, ester or amide groups, contain at least one group which is reactive towards isocyanates and contain at least one tertiary amino group and/or ammonium group, or mixtures thereof, with III) unmodified polyisocyanates E), and optionally with IV) C4-C30-hydrocarbons G) which are straight-chain or branched, saturated or mono- or poly-unsaturated and contain at least one group which is reactive towards isocyanates, and optionally with V) polyalkylene oxide polyether alcohols F) which optionally contain ester groups, the ratio of equivalents of NCO groups of compo-nent III) employed to the sum of the groups of components II), IV) and V) which are reactive towards isocyanates being at least 0.1:1 to about 1000:1, preferably 4:1 to 1000:1, are employed.

9. The Process according to Claim 1, in which water-dispersible polyisocyanate mixtures (I) which are obtained by reaction, in any desired sequence, of II) (cyclo)aliphatic amines which optionally con-tain ether, ester or amide groups, contain at least one group which is reactive towards isocyanates and contain at least one tertiary amino group and/or ammonium group, or mixtures thereof, with III) unmodified polyisocyanates E) and with V) polyalkylene oxide polyether alcohols F) which optionally contain ester groups, the ratio of equivalents of NCO groups of component III) employed to the sum of the groups of components II) and V) which are reactive towards isocyanates being at least 2:1, preferably 4:1 to about 1000:1, are employed.

10.TheProcess according to Claim 1, in which water-dispersible polyisocyanates (I) which are obtained by reaction, in any desired sequence, of II) A) amines which contain a group which is reactive towards isocyanates, of the formula A 1) in which Y' represents -O-, -NH- or -NR3-, wherein R3 represents methyl or ethyl, R1 and R2 a) independently of one another represent C1-C4-alkyl or C3-C6-cycloalkyl, b) represent a radical of the formula wherein R4 and R5 independently of one another represent hydrogen or methyl, with the condition that always one of the radicals represents hydrogen, R6 represents methyl or ethyl and a assumes values from 0 to 10, or c) represent a C2-C4-alkyl radical, substituted by one or more tertiary amino groups and/or ammonium groups, of the formulae or wherein b assumes values from 0 to 2, q and t independently of one another assume values of 1 or 2, r and s independently of one another assume values from 0 to 3 and R6 has the abovementioned meaning, or d) together with the N atom to which they are bonded form a 5- or 6-membered ring of the formula wherein Z represents or or wherein m assumes values from 0 to 2 and a, R4, R5 and R6 have the abovementioned meaning, and X represents C2- to C10-alkylene, C5- to C10-cycloalkylene, a radical of the formula wherein R4, R5 and a have the abovementioned meaning, or a radical of the formula in which a, R4, R5, R1 and R2 have the abovementioned meaning, or A 2) of the formula wherein Y2 represents -O-, -NH- or NR3-, wherein R3 has the abovementioned meaning, n and p independently of one another assume values of 1 or 2 and R1 has the abovementioned meaning, or A 3) of the formula wherein n, p and R1 have the abovementioned meaning, or A 4) of the formula wherein n, p, R1 and R2 have the abovementioned meaning, or B) amines which contain more than one group which is reactive towards isocyanates and optionally ether and/or ester and/or amide groups and have a molecular weight of less than 10 000 g/mol, or C) the compounds which are reactive towards isocyanates and contain ammonium groups obtained by reaction of A) or B) by pro-tonation and/or quaternisation, or any desired mixtures of A) to C), with III) a mixture of one or more unmodified polyisocyan-ates E) having - an average NCO functionality of 2.0 to 8.0, preferably 2.0 to 6.0 and particularly prefer-ably 2.1 to 4.4 and in particular 2.3 to 4.3, and - a content of isocyanate groups of 10 to 50 % by weight, preferably 19 to 24 % by weight, based on the mixture III, optionally with IV) C4-C30-hydrocarbons G) which are straight-chain or branched, saturated or mono- or poly-unsaturated and contain at least one group which is reactive towards isocyanates, and optionally with V) mono- or polyvalent polyalkylene oxide poly-ether alcohols F) which contain a statistical average of 5.0 to 70 ethylene oxide units and optionally contain ester groups, are employed.

11. Water-dispersible polyisocyanate mixtures with .alpha.) a content of isocyanate groups of 10 to 700, preferably 10 to 300 milliequivalents per 100 g of mixture, .beta.) an average NCO functionality of ?1.0, preferably 1.0 to 5, .gamma.) a content of ethylene oxide units of 0 to 30 % by weight, preferably 0 to 20 % by weight, based on the mixture, wherein the polyethylene oxide chain has an average molecular weight (number average) of 100 to 3500, preferably 100 to 1000, particu-larly preferably 100 to 6 00 g/mol, .delta.) a content of tertiary amino groups or ammonium groups of 50 to 5000, preferably 50 to 3500 milliequivalents per 100 g of mixture, and .epsilon.) a content of hydrophobic radicals of 1 to 250 milliequivalents per 100 g of mixture.

12. Water-dispersible polyisocyanate mixtures with .alpha.) a content of isocyanate groups of 47 to 595 milliequivalents, preferably 238 to 476 milli-equivalents, based on 100 g of the mixture, .beta.) an average NCO functionality of 1.5 to 4.2, preferably 2.0 to 4.2, .gamma.) a content of ethylene oxide units of >10 to 30 %
by weight, based on the mixture, wherein the polyethylene oxide chain has an average molecular weight (number average) of 100 to 3500, preferably 100 to 1000, particularly preferably 100 to 600 g/mol, and .delta.) a content of tertiary amino group or ammonium groups of 1 to 500, preferably 5 to 300 milli-equivalents per 100 g of mixture, and the protonation and/or quaternisation products thereof, and the aqueous dispersions and prepara-tions prepared therefrom.

13.TheProcess according to Claim 1, in which the cellulose-containing materials are paper or paperlike materials.

14.TheProcess according to Claim 1, in which the cellulose-containing material, which is present as a dispersion of the fibre raw materials, is treated in the pulp by adding the water-dispersible polyisocyanate mixtures (I) to the cellulose-con-taining fibre raw material dispersion as an aqueous emulsion or directly.

15.TheProcess according to Claim 1, in which the cellulose-containing material, which is present in the form of a finished base paper, is treated on the surface with the water-dispersible polyiso-cyanate mixture (I).

16.TheProcess according to Claim 1, in which 0.001 to 50 % by weight of water-dispersible poly-isocyanate mixture (I), based on the dry, cellulose-containing fibre raw material, is employed.

17.TheProcess according to Claim 1, in which the water-dispersible polyisocyanate mixture is employed as a mixture with reactive sizing agents, preferably with alkylketene dimers, or alkenylsuc-cinic anhydride and/or conventional retention or wet-strength agents.