CA1061969A - Incorporation of a gaseous blowing agent into a liquid resin - Google Patents

Abstract

ABSTRACT

In the manufacture of insulating and lightweight construction materials, which can contain fillers, and which were produced by physical foaming; the addition of fillers has involved difficulties. This arises because materials having relatively rough surfaces, as with most fillers, accelerate the collapse of liquid foams so greatly, that the addition of fillers was a problem in the case of physically foamed resins. The process of this invention increases the stability of reaction resin foams and conden-sation resin foams, so that the foam can be mixed with curing agents and accelerators, as well as lightweight fillers, and if appropriate, heavier fillers. The process involves contacting a thin film of the liquid resin, in a pressure vessel, with a blowing agent, causing the liquid resin to flow, without absorbing bubbles of the agent, down an elongated surface. The liquid resin film absorbs the agent so rapidly, that the flowing film can be immediately withdrawn from the vessel, and allowed to expand and cure into a foamed resin.

Description

~La6~9~
The present invention relates to a process for the manufacture of insulating materials and lightweight constructional materials, which can contain fillers, and have been produced from cold-curing or hot-curing reaction resins and/or condensation resins by physical foaming, and to a device for carrying out this process.
DOS (German Published Specification) 1,504,654 has disclosed a process and a device for the manufacture of foams, for example from mixtures of unsaturated polyesters and monomers containing _ C = CH2 groups. According to this process, a suitably viscous liquid mixture, for example, a polyester resin, is mixed in a pressure chamber with a blowing gas or with agents which generate such a gas and are soluble or dispersible in the liquid mixture, during which mixing the mixture remains practically free from bubbles~ The nature of the blowing agent should be such that it is absorbed by the mixture at relatively high pressures and relatively low temperatures but forms a foam with the mixture at low pressures and higher temperatures.
From the mixing chamber, the mixture is allowed to issue ~hrough a nozzle into a zone of such pressure that foaming occurs. The leng~h to diameter ratio of the nozzle should be between about 1:1 and 5:1. Further charac~eristics of the device described in the above-mentioned application are certain rotating stirring devices containing dlstribu~ors which direct the flow of liquid in the mixing chamber in such a way that the mixing process takes place uniformly.
As long as the foams have not yet been cured, their dimensional stability is of course limited but can be influenced favourably by surface-active agents. The addition of `~ 619~9 fillers has hitherto always encountered diffic~ties, because materials having relatively rough surfaces, as is the case with most fillers, are known to accelerate the collapse of liquid foams so greatly that for this reason the addition of fillers as a rule remained a problem in the case of physically foamed resins.
It was therefore desirable to provide foams manufactured from reaction resins and/or condensation resins, which are stable for a longer time than the previously known foams~ especially if fillers are added.
It has now been found, surprisingly, that the stability of reaction resin foams and condensation resin foams can be increased substantially by the process described in more detail below, so that the resulting fine-pored foam can be mixed not only with curing agents and accelerators but also with lightweight fillers and if appropriate also with heavier fillers.
According to the invention there is provided a process of manufac-turing foamed materials from a liquid thermosetting resin having a viscosity less than 6000 cP, comprising the steps of contacting a thin unbroken film of the liquid resin in a pressure vessel under pressure of 3 to 350 bars at a temperature of between 0 to 50C for a residence time of 0.1 to 120 minutes ~, with a blowing agent having a boiling point under normal pressure which is below 0 C, causing the liquid resin to smoothly flow without absorbing dis-cernible bubbles of the blowing agent down and over an elongated surface means having a vertical component disposed within the pressure ~essel whereby ; the liquid resin film absorbs the blowing agent so rapidly that the resin film flowing off from the elongated surface means can immediately be with-drawn from the pressure vessel, deposited on a surface, subjected to pressure release, allowed to expand and to cure into a foamed resin.
Preferably, the pressure in the pressure vessel is 20 to 180 bars and the temperature is between 10 and 30 C. The preferred resiclence time is 0.5 to 30 mins.

. , .
~....

~61969 The gas-liquid interface may be enlarged by introducing the blowing agent into the resin through a distributor device or by allowing the resin to flow over inserts in the pressure vessel.
Preferably the resin contains a~iliaries, additives, fillers or accelerators and is cured by addition of filler-curing agent combinations.
The invention may also include insulating materials and lightweight constructional materials manufactured according to the process of the inven-tion.
The invention also provides a device for carrying out the process according to the invention, comprising a stock vessel containing the blowing agent, a stock vessel for the resin or a resin/accelerator mixture, and a stock vessel for the curing agent or a resin/curing agent mixtureg leading from each stock vessel, a feed pipeline to a mixing chamber, and at least one pressure vessel having means therein for enlarging the gas-liquid inter-face, which pressure vessel in connected to the feed pipelines leading from the stock vessel for the resin or for the resin/accelerator mixture and from the stock vessel for the blowing agent, and has an inlet for the resin or for the resin/accelerator mixture. In a preferred embodiment of the device the feed pipeline leading from the stock ~6~96~

vessel for the curing agent or for the resin/curing agent mixture enters the pressure vessel.
The means in the pressure vessel for enlarging the gas-liquid interface may comprise a distributors device for the blowing agent in the lower part of the-pressure vessel or inserts in the pressure vessel over which the resin may flow.
The inserts which enlarge the interface can consist, for example, o~ lamellae.
A further sub~ect of the invention is a device for carrying out the p~ocess according to the invention in which the pressure vessel is interposed in the feed pipeline leading from the mixing chamber.
The following reaction resins and condensation resins can be used in the process according to the invention:

A Epoxide resins based on epoxide compoumds having more than one .
epoxide group per molecule.
By epoxide compounds with more than one epoxide group per molecule there are understood, for example, aliphatic, cycloaliphatic, aromatic or heterocyclic polyepoxides which on average contain more than one epoxide group per molecule.
~0 The polyepoxide compounds to be used can be polygly-cidyl ethers of polyhydric phenols, for example of pyrocate-chol, resorcinol OT hydroquinone, of 4,4'-dihydroxy-diphenyl-methane, of 4,4'-dihydroxy-3,3'-dimethyldiphenyl-methane, of ~6 IL9~9 4,4'-dihydroxydiphenyldimethylmethane (bisphenol A), of 4,4'-dihydroxydiph~nylcyclohexane, o~ 4,4'-dihydroxy-3,3'-dimethyl-diphenylpropane, of 4,4'-dihydroxydiphenyl, of 4~4'-dihydroxy-diphenylsulphonè, of tris-(4-hydroxyphenyl)-methane, o~ -the chlorina-tion and bromination products of the abovementioned diphenols7 o~ novolacs (that is to say of reaction products o~ monohydric or polyhydric phenols with aldehydes~ especially formaldehyde, in the presence o~ acid catalysts)l of diphenols which have been obtained by esterification of 2 mols of the sodium salt o~ an aromatic hydroxycarboxylic acid with one mol o~ a dihalogenoalkane or dihalogenodialkyl ether (compare British Patent 1,017,612), or o~ polyphenols which have been obtalned by condensation of phenols and long-chain halogeno-paraffins containing at least 2 halogen atoms ~compare British Patent Specification 1,0249288). Further compounds to be mentioned are: polyepoxide compounds based on aromatic a~ines and ~piohlorohydrin, for example N-di-(2~3-epoxypropyl);
anlline, N,N'-dimethyl-N~N'-diepoxypropyl-~,4'-diamino-d~phe-nylmethane~ N,N'-tetraepoxypropyl-4,4i-diaminophenylme~hane and N-diepoxypropyl-4-amino-phenyl-glycidyl-ether (compare Briti~h Patent Specifioatlo~s 772?830 and al6,923).
It is also possible to U88 glycidyl *ster~ of pol~- -basic aromatic 9 aliphatic and cycloallphatic carboxylic acids, for example phthalic acid dig}ycidyl estersp e~pecially o phthalic acid glycidyl ester~ with more ~han 5.5 ep~xid~
equivalents per kilogram9 adipic acid diglycidyl esters and glycidyl ester~ o~ reaction product~ of 1 mol Q~ an aromatic or cycloaliphatic dicarboxyli~ acid anhydride a~d ~ mol of a diol or l/n mol o~ a polyol wlth n hydroxyl ~roups or hex~-hydrophthalic acid diglycidyl e~te~ which can optionally be 3ub~tituted by methyl group~.
Le A 15 930 - 6 -... .

~6~969 Glycidyl ethers o~ polyhydric alcohols9 ~or example of 1,4-butanedlol, 1,4-butenediol, glycerol~ trimethylolpropane, pent~erythritol and polyethylene glycols can also be usedl :
Triglycidyl isocyanurate~ N,N'-diepoxypropyloxamide~ polygly-cidyl thioethers o~ poly~unc-tional thiols, such as, ~or example, o~ bis-mercaptomethylbenzene, diglycidyl-trimethyl-enetrisulphone~ and polyglycidyl ethers based on hydantoins are also o~ interest.
Finally, the following should be mentioned: epoxida-tion products of poly-unsat~rated:compounds, such as vegetable oils and their conversion productsj epoxidation products o~
diolefines and ~olyolefines, such as butadiene? vinylcyclohex-ene, 1,5-cyclooctadiene, 1,5~9-cyclododecatriene and polymers and copolymers which stilI contain epoxidisable double bonds ~or example those based on polybutadiene, polyisoprene, buta-: diene-styrene copolymers, divinylbenzene,~dicyclopentadiene and unsaturated polyesters~:~and~also epo~idation product~ o~
olefines which are accessible by a Diels-Alder addition and are subsequently converted into polyepoxides by epoxidation with per-compounds, or epoxidation products o~ compounds which contaln two cyclopentene or cyolohexene rings linked via bridge atoms or bridge~atom groups. Polymers o~ unsaturated monoepoxides, for example of ~ethacrylic acid glycidyl ester or allyl glycid~l ether, shoul~ also be m~ntionèd. ~ .
25 ~ PrePerably, diglycidyl etherq of bisphenol A~ o phthalic acid diglyoidyl esters wi~h more than 5.~5 epoxide equivalents per ~ikilogram, m- and p-phthalic acid~diglycidyl ; esters, hexah~drophthalic acid di~l~cidyl esters and tetra-hydrophthalic acid d1glyoidyl e~ters:are employed.
Compounds whloh ~an be used ~or euring are compounds known as epoxide re~ln curing agents, such as are descrIbed, _ 7 _ ~(~619G99 for example, in Methoden der Organischen Chemie (Methocls of Organic Chemistry), ~Houben-Weyl), 4th editionJ volumn 14/2~ Georg Thieme VerlagJ
Stuttgart, 1963J pages 499 - 532. The preferred curing agents are amines (ibid.J pages 516 - 523).
B. Reactants which ~i~e Rolyurethanes Starting components which can be employed to make resins for use in the process according to the invention are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as are described, for example, by W. Siefgen in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136J for example ethylene-diisocyanate, 1,4-tetramethylene-diisocyanate, 1,6-hexamethylene-diisocyanate, 1,12-dodecane-diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and-l, 4-diisocyanate and any desired mixture of these isomers, l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane ~DAS ~German Published Specification) 1,202,785)J 2,4- and 2J6-hexahydrotoluy-lene-diisocyanate and any desired mixtures of these isomersJ hexahydro-1,3-and/or -1,4-phenylene-diisocyanate, perhydro-2,4'- and/or~,4'-diphenylmeth-~
ane-diisocyanate, 1,3- and 1,4-phenylene-diisocyanate, 2~4- and 2,6-toluylene-diisocyanate and any desired mixtures of these isomers, diphenylmethane-2J41- and/or -4,4'-diisocyanate, naphthalene-lJ5-diisocyanateJ triphenyl-methane-4,4',4"-triisocyanate, polyphenyl-polymethylene-polyisocyanates, such as are obtained by aniline-formaldehyde condensation and subsequent phosgenation and are described, for example, in British Patent Specifications 874,430 and 848,671, perchlorinated aryl-polyisocyanates, such as are described, for example, in German Auslegeschrift (German Published Specifi-cation) 1,157,601, polyisocyanates containing carbodiimide groups, such as are described in German Patent Specification 1,092,007, diisocyanates, such as are described `` 1~61969 in US Patent Specification 3,492,330, polyisocyanates containing allophanate groups~ such as are described, for example, in Brltish Patent Specification 994,890, Belgian Patent Specification 761,626 and Canadian Patent No.
964,276, polyisocyanates containing isocyanurate groups9 such as are de-scribed, for example, in German Patent Specifications 1,022,789, 1,222,067 and 1,027,394 and in German Offenlegungsschriften (German Published Specifi-cations) 1,929,034 and 2,004,048, polyisocyanates containing ~ethane groups, such as are describedg for example, in Belgian Patent Specification 752,261 or in US Patent Specification 3,394,164, polyisocyanates containing acylated urea groups, according to German Patent Specification 1,230,778, polyiso-cyanates containing biuret groups, such as are described, for example, in German Patent Specification 1,101,394, in British Patent Specification 889~o50 and in French Patent Specification 7,017,514, polyisocyanates pre-pared by telomerisation reactions, such as are described, for example, in Belgian Patent Specification 723,640, polyisocyanates containing ester groups, such as are describedj for example~ in British Patent Specifications 956,474 and 1~072,956, in US Patent Specification 3,567,763 and in German : Patent Specification 1,231,688, and reaction products of the abovementioned isocyanates with acetals according to German Patent Specification 1,072,385.
It is also possible to employ the distillation residues, containing isocyanate groups, obtained from the industrial manufacture of isocyanates, these residues being dissolved, if appropriate, in one or more of the above-mentioned polyisocyanates. It is also possible to use any desired mixtures of the abovementioned polyisocyanates.
As a rule, the industrially easily accessible polyisocyan-619~5~
ates are partlcularly preferred, for example 2,4- and 2,6-toluylene-diisocya-nate and any desired mixtures of these isomers ~"TDI"), polyphenyl-polymethy-lene-polyisocyanates, such as are manufactured by aniline-formaldehyde con-densation and subsequent phosgenation ~"crude MDI") and polyisocyanates con-taining carbodiimide groups, urethane groups, allophanate groups, isocyanur-ate groups, urea groups or biuret groups ("modified polyisocyanates").
Further starting components to be employed for making resins for use in the process according to the invention are compounds with at least two hydrogen atoms which are reactive towards isocyanates, and with a molec-ular weight of, as a rule, 400 - 10,000. By these compounds there are under-stood compounds containing amino groups, thiol groups or carboxyl groups and, preferably, polyhydroxy compounds, especially compounds containing 2 to 8 hydroxyl groups, particularly those of molecular weight 800 to 10,000, preferably 1,000 to 6,000, for example polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyesteramides, containing at least two, as a rule 2 to 8, but preferably 2 to 4,hydroxyl groups, such as are in them-selves known for the preparation of homogeneous and of cellular polyurethanes.
The polyesters containing hydroxyl groups which can be used are, for example, reaction products of polyhydric, preferably dihydric and option-ally additionally trihydric alcohols with polybasic, preferably dibasic, carboxylic acids. Instead of the free polycarboxylic acids it is also possible to use the corresponding polycarboxylic acid anhydrides or corres-ponding polycarboxylic acid esters of low alcohols, or their mixtures, for the preparation of the polyesters. The polycarboxylic acids can be aliphatic, cycloaliphatic, 106-~9G9 aromatic and/or heterocycl~c and can optionally be sub~titu-ted, for example by halogen atoms, and/or be unsaturated.
As examples of the above there may be mentioned: succinic acid, adipic acid~ suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalio anhydride, endomethylenetetra-hydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimeric and trimeric ~atty acids such as oleic acid, optionally mixed with monomeric ~
fatty acids, terephthalic acid dimethyl ester and terephthaIis acid bis-glycol ester. Examples o~ polyhydric alcohols which can be used are ethylene glycol, 1,2- and l,~-propylene~
glycol, l~ 4- and 2,3-butylene glyGo~ 6-hexanediol, 1,~8-octanediol, neopentyl glycol~ cyclohexanedimethanol (1~94-:: bis-hydroxymethylcyclohexane), 2-methyl~ -propanediol, glycerol, trimethylolpropans, 1,2,6-hexanetriol 9 1 ~ 2 t 4-butane-triol, trimethylclethane, pentaerythrltol,~qui~itol, mannLtcl-i and sorbitol, methylglycoside and also diethylene gly~ol,. tri-. 20 ethylene glycol, tetraethylene gl~col, polyethylene glycols, ~
i. . ~ , ~ .
dipropylene glycol, polypropylene glycol3 ? dibutyl~ne glycol and polybutylene glycols. The polyestars can in part con-.
. tain terminal carboxyl group Polyester~ obtainad;from :
j~ lactones, ~or e~ample E-caprolactone, or hydroxycarboxylic acids, ~or example ~-hydroxycaproic acid, can also b~
employed.
The polyether~, containing at least two, as;a rule two~
to eight, pre~erably ~wo to three, hyd~o~yl gr~up~ which ca~
. be used according to the invention.are ~l~o of a type:whi~h~i~
. 30 in itself known and are prepared~ ~or example, by polymeris~-: tion o~ epoxides such as ethylene oxide, propyle~e oxlde~

96~

butylene oxide 9 tetrahydro~urane, s-tyrene oxide or epichloro-hydrin wi-ththemselve~orexample in the presence o~ BF3, or by addition reaction of these epoxldes 9 optionally mixed with one another or used successively, with s-l;arting componen-ts with reactive hydrogen atoms, such as alcohols or amines, for example water, ethylene glycol, 1,3- or 1,2-propylene glycol, trimethylolpropane 7 4,4'-dihydroxydiphenylpropane, aniline~
ammonia9 ethanolamine or e-thylenediamine. Sucrose poly~
ethers~ such as are described, for example9 in German Auslege-schriften (German Published Speci~ications) 1,176~358 and 1,064,938, can also be used according to the invention.
Frequently, polyethers are preferred which predominantly ~up ; to 90% by weight) based on all OH groups present in the poly-ether) contain primary OH groups. Polyethers modified with vinyl polymers, such as are produced~ for example9 by poly-merisation of styrene and acrylonitrile in the presence of polyethers (US Patent Specifications 3,~8~,351, 3~304?27 3,523~093 and 3,110~695 and German Patent Speci~ication 1,152,536) are also suitable, as are polybutadienes contain-ing OH groups.
Amongst the polythioethers -there should in particular be mentioned the condensation products of thiodiglycol with itself and/or with other glycols, dicarboxylic acids~ formal-dehyde, aminocarboxylic acids or aminoalcohols. Depending on the co-component, the products are polythio-mixed ethers, polythioether-esters or polythioether-ester amides.
Polyacetals which c~n be used are, ~or example, the compounds which can be prepared from glycols, such a~ dlethyl-ene glycol7 triethylene glycol, 4,4'-dihydroxyethoxy~diphenyl-dimethylmethane or hexanediol, and ~ormaldehyde. Polyacetals which are suitable ~or use according to the inve~tion can also ~L~6~L~6!~
be prepared by polymerisation of cyclic acetals.
Polycarbonates, containing hydroxyl groups, which can be used are those of a type which is in itself known, which can be prepared, for example, by reaction of diols such as 1,3-propanediol, 1,4-butanediol and/or 1,6-hexanediol, diethylene glycol, triethylene glycol or tetraethylene glycol with diaryl carbonates, for example diphenyl carbonate or phosgene.
The polyester-amides and polyamides include, for example, the predominantly linear condensates obtained from polybasic saturated and unsat-urated carboxylic acids or their anhydrides and polyfunctional saturated and unsaturated amino-alcohols, diamines, polyamines and their mixtures.
Polyhydroxy compounds which already contain urethane groups or urea groups, and optionally modified natural polyols, such as caster oil, carbohydrates and starch, can also be used. Addition products of alkylene ", oxides to phenolformaldehyde resins or to urea-formaldehyde resins can also be employed according to the invention.
Examples of these compounds to be used according to the invention are described, for example, in High Polymers, volume XVI, "Polyurethanes, Chemistry and Technology"J edited by Sanders-Frisch, Interscience Publishers, New York, London, volume I, 1962, pages 32 - 42 and pages 44 - 54 and volume II, 1964, pages 5 - 6 and 198 - 199, and also in the Kunststoff-Handbuch, volume VII, Vieweg-~ochtlen, Carl-Hanser-Verlag, Munich, 1966, for example on pages 45 to 71. In the process according to the invention, water can be co-used as a blowing agent.
Further, catalysts are frequently co-used in the process.
Such catalysts are of a type which is ~{~6~9~9 in itself known, ~or example tertiary amines, such as triethylamine, tri-butylamine, N-methyl-morpholine, N-ethyl-morpholine, N-coco-morpholine, N,N, N', N'- tetramethyl-ethylenediamine, 1,4-diaza-bicyclo-(2,2,2)-octane, N-methyl_N'-dimethyl-aminoethyl-piperazine, N,N-dimethylbenzylamine, bis-(N,N-diethylaminoethyl) adipate, N,N-diethylbenzylamine, pentamethyl-diethylene-triamine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethyl-1,3-butanediamine, N,N-dimethyl-~-phen~lethylamine,1,2-dimethylimidazole and 2-methylimi-dazole.
Examples of tertiary amines which contain hydrogen atoms which are active towards isocyanate groups are triethanolamine, triisopropanol amine, N-methyl-diethanolamine, N-ethyl-diethanolamine, N,N-dimethyl-ethanolamine and their reac~ion products with alkylene oxides, such as propylene oxide and/or ethylene oxide.
Further catalysts which can be used are sila-amines with carbon-silicon bonds, such as are described, for example, in German Paten~ Specifi-- cation 1,229,290 for example 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyl-tetramethyl-disiloxane.
Nitrogen-containing bases such as tetraalkylammonium hydroxides, and also alkali metal hydroxides such as sodium hydroxide, alkali metal phenolates such as sodium phenolate or alkali metal alcoholates such as sodium methylate can also be used as catalysts. Hexahydrotriazines can also be employed as catalysts.
Organic metal compounds, especially organic tin compounds, may also be used as catalysts.
Preferred organic tin compounds which can be used are tin(II) salts of carboxylic acids such as tin(II) acetate, tin(II) octoate, tin~ ethylhexoate and tin~II) laurate and the dislkyl-tin salts o carboxylic acid, such as, for example, dibutyl-tin diacetate, dibutyl-tin dilaurate, dibutyl-tin maleate or dioctyl-tin cliacetate. Further examples of catalysts to be used in the process according to the invention, and details of the mode of action of the catalysts, are described in the Kunststoff-Handbuch, volume VII, published by Vieweg and Hochtlen, ~arl-Hanser-Verlag, Munich 1966, for example on pages 96 to 102.
As a rule, the catalysts are employed in an amount of between about 0.001 and 10% by weight, based on the amount of compounds which contain at least two hydrogen atoms which are reactive towards isocyanates and have a molecular weight of 400 to 10,000.
Surface-active additives ~emulsifiers and foam stabilisers) can also be co-used. Examples of possible emulsifiers are the sodium salts of caster oil sulphonates or of fatty acids or salts of fatty acids with amines such as diethylamine oleate or diethanolamine stearate. Alkali metal salts or ammonium salts of sulphonic acid, such as, sayJ of dodecylbenzenesulphonic acid or dinaphthylmethanedisulphonic acid, or of fatty acids such as ricinoleic acid or of polymeric fatty acids can also be co-used as surface-active additives.
Foam stabilisers which can be used are, above all, polyether-siloxanes.- The structure of these compounds is generally such that a copolymer of ethylene oxide and propylene oxide is bonded to a polydimethylsiloxane radical. Such foam stabilisers are described, for example, in U.S. Patent Specification 2,764,565.
Reaction retarders, for 96~

example compounds which have an acid reaction, such as hydrochloric acid or organic acid halides, can also be co-used, as can cell regulators of the type which is in itself known, such as paraffins or fatty alcohols or dimethyl-polysiloxanes, as well as pigments or dyestuffs and flameproofing agents o the type which is in ;tself known, for example tris-chloroethyl phosphate or ammonium phosphate and ammonium polyphosphate, as well as aging stabilisers and weathering stabilisers, plasticisers and fungistatlc and bacteriostatic substances, and fillers such as barium sulphate, hydrated aluminium hydroxide, kieselguhr, carbon black or whiting.
Further examples of surface-active additives and foam stabilisers, cell regulators, reaction retarders, stabilisers, flameproofing substances, plasticisersJ dyestuffs and fillers and fungistatic and bacteriostatic sub-stances, which can optionally be co-used according to the invention, and details of the use and mode of action of these additives, are described in the Kunststoff-Handbuch ~Plastics Handbook)~ volume VI, published by Vieweg and Hochtlen, Carl-Hanser-Verlag Munich 1966, for example on pages 103 to 113.
The reactants are reacted in accordance with the one-step process which is in itself known, the prepolymer process or the semi-prepolymer pro-cess.
C. Crosslinkable acrylate and methacrylate resins These can also be used as reaction resins in the process of the invention. They are combinations of monoacrylates and/or monomethacrylates, in combination with dimethacrylates and oligomethacrylates and~ optionally, polymeric acrylates, methacrylates and their copolymers of very diverse degrees of polymerisation, with or without functional groups, ~such as, for example, double bonds), which are capable of 1~619~9 participating in the polymerisation or copolymeri~ation when the foam is ~ceing cured. The polymers of this class of compo~md to ~e used according to the invention are described, for example, in Methoden der Organischen Chemie ~Methods Or Organic Chemistry) ~Houben-l~'eyl), 4th edition, volume 14/1, Georg Thieme Verlag, Stuttgart 1962, pages 1,010-1,078.
The curing can be efected by the same radlcal-forming agents as the compounds mentioned for the case of the polyesters ~see under F) and, optionally, amine accelerators.
D. Isocyanurate resins can also be used in the sense of the present invention. Examples are the isocyanurate resins mentioned in DT-PS lS112,285, lQ DOS ~German Published Specification) 1,595,844 and BE-PS 697,411.
As regards practical execution, similar remarks apply as to the polyurethane intermediates. The cyclisation catalysts are preferably added to the isocyanates under pressure, optionally in combination with up to 30%
by weight of diols and/or polyols, relative to the total reaction mixture, before releasing the pressure.
E. Phenolic resins such as are described, for example, in Methoden ~- der Organischen Chemie (Methods of Organic Chemistry) (Houben-Weyl), 4th edition, volume 14/2, Georg Thieme Verlag, Stuttgart, 1963, pages 193 - 291, should also be mentioned as further condensation resins.
F. A preferred embodlment consists of the use of unsaturated polyester resins, that is to say of solutions of unsaturated polyesters in copolymeris-able compounds. The unsaturated polyesters to be used in the process according to the invention are prepared according to known processes by polycondensation of at least one ~,~-ethylenically unsaturated dicarboxylic acid with 4 or 5 carbon atoms as a rule or its ester-forming derivatives, optionally mixed with L9~i9 up to 9Q mol %J relative to the unsaturated acid CODIpOnent, of at least one aromatic, cycloaliphatic d;carboxylic acid with 8 to 10 carbon atoms and/or at least one saturated aliphatic dicarboxylic acid with 'I to 10 carbon atoms or its ester-forming derivatives, with at least one polyhydroxy compound, preferably a dihydric alcohol with 2 to 8 carbon atoms - i.e. polyesters as described by J. Bj~rksten et al. in "polyesters and their Applications", Reinhold Publishing Corp., New York 1956. Examples of unsaturated dicarboxylic acids, or their derivatives, to be used preferentially are maleic acid or maleic anhydride or furmaric acid. However, it is also possible to use, for example, mesaconic acid, citraconic acid, itaconic acid or chloromaleic acid.
Examples of the aromatic, cycloaliphatic or saturated aliphatic dicarboxylic acids, or their derivatives, which are used are phthalic acid or phthalic anhydride, isophthalic acid, terephthalic acid, hexahydrophthalic acid or tetrahydrophthalic acid or their anhydrides, endomethylenetetrahydrophthalic acid or its anhydride, succinic acid or succinic anhydride and succinic acid esters and chlorides, adipic acid and sebacic acid. For the preparation of resins of low inflammability it is possible to use, for example, hexachloro-endomethylenetetrahydrophthalic acid (Het-acid), tetrachlorophthalic acid, tetrabromophthalic acid, dibromoricinoleic acid or tetrabromoricinoleic acid.
Flame resistance is also achievable by addition of halogen-containing com-pounds which are not co-condensed in the polyester, such as, for example, chloroparaf~in. Polyesters to be used preferentially contain co-condensed maleic acid radicals of which up to 25 mol % can be replaced by phthalic acid radicals or isophthalic acid radicals. Dihydric alcohols which can be employed are ethylene glycol, 1,2-propanediol,1,3-propanediol, diethylene glycol, di-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,4-butenediol, neopentyl glycol, 1,6-hexanediolJ perhydrobisphenol, the oligomers of ethylene oxide and propylene oxide, sugar alcohols and other cycloaliphatic and aromatic diols such as, for example, p-dimethylolbenzene or its lsomers, and their hydrogen-ation products, and others. Ethylene glycol, 1,2-propanediol, diethylene gly-col and dipropylene glycol are used preferentially Further modifications are possible by incorporation of up to 10 mol %, based on the alcohol component or acid component, or mono-, di- and tetra-hydric alcohols, such as methanol, isopropanol, butanol, benzyl alcohol, cyclohexanol and tetrahydrofurfuryl alcohol, trimethylpropane and pentaery-thritol and by incorporation of monobasic and tribasic acids such as benzoic acid, oleic acid, linseed oil fatty acid, ricinoleic acid, ricinenic acid~
~-ethylhexanoic acid, acrylic acid, methacrylic acid, crotonic acid and trimellitic acid.
The acid numbers of the polyesters should be between 1 and 50, preferably between 5 and 25, the OH numbers should be between 10 and 100, preferably between 10 and 50, and the (number auerage) molecular weights should be between approx. 500 and 10,000, preferably between approx. 700 and 3,000 ~up to values of 5000 measured by vapour pressure osmosis in dioxane and acetone, if both values differ from each other, the lower value is con-sidered to be the more accurate one; above values of 5000 measured by mem-brane osmosis in acetone).
Suitable copolymerisable compounds in the sense of the invention, which are employed in amounts of 10 to 90, preferably 20 to 50, % by weight, relative to the sum (polyester + copolymerisable compounds), are the unsat-urated compounds customary in the polyester ~echnology, which preferably carry ~-substituted vinyl groups or ~ substituted allyl groups, styrene being preferred, however it is also possible to use, for example, halogen-ated and alkylated styrenes, in which the alkyl groups can contain 1-4 car-bon atoms, such as, for example, vinyltoluene, divinylbenzene, ~-methyl-~tyrene~ tert.- but~lstyrene and chlorostyrenes, vinyl esters of carboxylic acids with 2 -6 carbon atoms, preferably vinyl acetate; vinyl ~6196~9 pyridine, vinylnaphthalene, vinylcyclohexane, acrylic acid and methacrylic acid and/or their esters with 1 - 4 carbon atoms in the alcohol component, their amides and nitriles, and mixtures which additionally contain maleic anhydride, maleic acid half-esters and maleic acid diesters with 1 - 4 car-bon atoms in the alcohol component, maleic acid half-amides and diamides or cyclic imides such as N-methylmaleimide or N-cyclohexylmaleimide; allyl compounds, such as allylbenzene and allyl esters, such as allyl acetate, allyl acrylate, allyl methacrylate, phthalic acid diallyl ester, isophthalic acid diallyl ester, fumaric acid diallyl ester, allyl carbonates, diallyl carbonates, triallyl phosphate and triallyl cyanurate.
In order to prevent undesired premature polymerisation of the polyester resins, it is advisable to add 0.001 to 0.1% by weight of polymer-isation inhibitors and, optionally antioxidants, to the resins already during their preparation.
Suitable auxiliaries of this type are, for example, phenols and phenol derivatives, preferably sterically hindered phenols, which contain alkyl substituents with 1 - 6 C atoms in both o-positions relative to the phen-olic hydroxyl group, amines, preferably secondary arylamines and their derivatives, quinones, copper salts of organic acids, and addition compounds of copper~I) halides to phosphites, such as, for example, 4,4'-bis-~2,6-di-tert.-butylphenol), 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxy-benzyl)-benzene, 4,4'-butylidene-bis-(6-tert.-butyl-m-cresol), 3,5-di-tert.-butyl-4-hydroxy-benzyl-phosphonic acid diethyl ester, N,N'-bis-(~-naphthyl)-p-phenylenediamine, N,N'-bis-(l-methylheptyl)-p-phenylenediamine, phenyl-~-naphthylamine, 4,4'-bis-(~,~-di-methylbenzyl)-diphenylamine, 1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxy-hydrociunamoyl)-hexahydro-s-trazine, hydroquinone, p-benzoquinone, toluhydroquinone, p-tert.-butylpyrocatechol, chloranil, naphthoquinone, copper naphthenate, copper octoate, Cu(I)Cl/triphenyl phos-phite, Cu~I)Cl/tri-3L~6~9~;9 methyl phosphite~ Cu(I)Cljtrischloroethyl phosphite, Cu(I)Cl/
tr~propyl phosphite ~nd p-nitrosodimethylaniline Further suitable stabilisers are described in Methoden der Organischen Chemie (Methods o~ Organio Chemistry) (Houben-Weyl), 4~h .
edition, volume 14/1, pa~e~ 433-452, 756; Georg Thiem~ Verlag, Stuttgart 9 1961. For example, p~benzoquinone used in a con-centration o~ O.Ol to 0~05% by weight, relative to the poly~
ester resin, is very sultable.
Polymerisation initiators used ~or the polyester resins are radical-forming agentsp preferably organic per-oxides. me polyester reslns contain customary amo~nts, preferably 0.1 to 2.0% by weight9 of polymerisation initia-tors. Examples of suitable initiator3 are diacyl per-oxides such as diacetyl peroxide9 dibenzoyl peroxide,~di-p-chlorobenzoyl peroxide, peroxy-esters such as tert.-~utyl peroxyacetate, tert.-butyl peroxybenzoate3 dicyclohexyl per-oxydicarbonate, alkyl peroxidss such as bis-(ter~.-b tyl perox~butane), dicumyl peroxlde9 tert.-butyl GUmyl p~roxi~e hydroperoxides5 such as cumene ~ydroperoxide and ter~.-butyl hydroperoxide, ketone peroxides such a~ cyclohexa~one h~dro-~ : , peroxide, methyl ethyl ketone hydroperoxide and acetylac~tone peroxide, or azoisobutyrodinitrile. However, inorganic radi-cal forming agents9such a~, for example, hydrog~ peroxide and potassium peroxydisulphate or ammo~ium peroxydi ~ phate can also be u~ed.
Example~ of sùitabl~ accelerators, which are gen~rally~
employed in amounts o~ 0~05 ~ 0o2% by weight, relati~e to the~
polyester re~in, are~amines~ ~uch as diethylaniline, di~ethyl aniline9 N,N-die~thoxyaniline and N,N-dipropoxyaniline and p-toluidine and bi~-t~-hydroxypropylj-p-toluidin~ pol~dlpate, and metal salt accelerators ~uch as cobalt n~ph~henate and~
E~ 2~ _ 21--1~6~916~

cobalt octoate and vanadyl p-toluene~ulphonate, optionally in conjunction with thioglycoll~c acid esters, such as are described, Eor example in DOS ~German Published Specification) 2,025,410.
The viscosity of the reaction resins and/or condensation resins to be used according to the invention is less than 6,()00 cP, and preferably between 800 and 4,000 cP. The resins can contain 0.1 - 10% by weight, based on the amount of resins, of additives which influence the viscosity~ especially the structural viscosity, such as, for example, hydrogenated caster oil, highly disperse silicas, polyethylene powders and the like. Furthermore, the reac-tive resins and!or condensation resins can contain 1 to 100% by weight, based on the amount of resin, of liquid or solid additives which are responsible for, or improve, the low inflammability and period of flame resistance, such as, for example, antimony trioxide, ZillC borate, hydrated aluminium hydroxide and others.
It is advantageous to co-use surface-active substances which individ-ually or as mixtures, influence the foaming, the foam density, the foam stability, the wetting ~for ex~lple of the fillers) and the foam structure ~ineness of pores, open cells or closed cells). As such substances, it is possible to use anionic or cationic detergents and/or non-ionic surface-active substances, such as, for example, turkey red oil, quaternary ammonium 2Q salts, ethylene oxide/propylene oxide polymers, ethylene oxide and/or prop-ylene oxide and/or butene oxide homopolymers and/or copolymers and/or their monoalcohol ethers, and thermoplastics which are soluble and/or swellable in the reactive resin mixture, particularly in the copolymerisable monomers, but in particular organic silicon compounds, for example siloxanes containing ethylene oxide or ~1969 propylene oxide, which are employed by themselves or, prefer-ably9 in combination with one o~ the abovementioned surface-active substances or with a mixture of such substances. The amount of the foam-in~luenclng agents can be 0.1 - 20%, pre-ferably 0.5 - 3%, relative to the amount of resin.
The react~n resins and/or condensation resins can furthermore contain 0.1 to 50% by weight, relative to the amount of resin, of soluble organic dyes-tuffs and organic and inorganic pigments, and 1 to 2~000~o by weight; preferably 1 300% by weight, relative to the amount of resin, of fillers and reinforcing agents in a pulverulent, fibrous, gritty or granular form; in the case of fibrous or granular fi}lers and reinforcing agents, these are pre~erably combined with the foaming mixture during or after the foaming process.
A preferred embodiment is a combination o~ the expan-ded react~n resin mixtures with organic and/or inorganic . .
lightweight ~illers o~ particle size diameter 1 - 200 mm or ,. . . . ~
above, but predominantly 2 - 30 mm. Posslble lightweight fillers are: thermoplastics and/or thermosetting resins which 20 are resistant to the reaction mixture up to curlng, and/or ~` hollow glass spheres and/or ~oam granules and/or expanded glass, expanded clay, expanded slate, pumice/tu~a, perllte (expanded volcanic rock3, aerated concrete ~ragmentq-and cel-lular glass ~ragments as well as mixtures o~ these lightweight ; 25 fillers and optionally also heavier fillers,such as, for example, calcium carbonate, dolomLte, quartz sand and 8rit~
and other silicate products o~ the same or sub~tan~ially~
smaller particle size, ~or example in the ranga~o~
200 mm and, i~ appropriate, larger st111.
~30 Exa~ples of ~uitable blowing agents are`air, carbon dioxide, hel1um, argon, nitrogen; vo~atile hy~rocarbons, ~or 23 - ~

, 6~96g e~ample propane, butane, pentanes and hexanes, volatile halogenated hydro-carbons, s~ch as, for example, CC13F, C2C12F4, C~IC12F, C~lF3, C~IClF2 and CC12F2, and others. A preferred blowing agent is carbon dioxicle, since it shows the greatest rate of absorption in the case of most resins; the use of carbon dioxide therefore as a rule makes it possible to work with relatively low pressures.
The characterising feature of the invention, the enlarging of the gas-liquid interface, canJ in one embodiment, be brought about by fitting a gas distribution device in a reaction vessel which does not possessa stirring device.
A simplified representation of an industrial apparatus suitable for the discontinuous and intermittent manufacturing process is shown in Figure 1. A pressure vessel 1, with a removable flanged lid 2, is partially filled (for example to 2l 3 of its volume) with reactive resin and/or conden-sation resin, via the feed device (19). Blowing gas flows, from a stock cylin-der 5 containing a blowing gas and provided with a manometer 6 and a valve 7, through feed pipeline 3 and a distributor (spray ring) 4 into the pressure vessel, the nozzles provided as outlet orifices for the gas being smaller than 1 mm, so that the gas bubbles into the resin. The gas bubbles rise through the resin in the direction of the surface and are partially or com-pletely absorbed by the resin. A gas pressure cushion forms above the resin, and from this cushion gas also diffuses into the resin.
When the pressure in the pressure vessel has risen to the desired pressure as a result of the gas which continues to flow in ~the pressure can be read off on the manometer 8), the overflow valve ~9) opens and the pres-sure is kept constant. After a certain residence time, the resin~has absorbed the 1~!6:~L969 desired proportion of gas. The requisite residence time primarily depends on the pressure in the system.
Before the end of the residence time, the valve 7 is closed to provide a quiescence time, during which any gas bubbles present are absorbed or can reach the surfaces.
When, after a quiescence time, all the gas present in the resin has either risen to the surface or been absorbed by the resin, the valve 16 can be opened. During and after the release of the pressure acting on the resin solution, a uniform fine-pore foam 18 is produced. To cure the foam, an appropriate curing agent or resin/curing agent mixture is introduced into the mixing chamber 12.
The amount of curing agent is metered in from the stock vessel 15 (of which the pressure can be read off on the manometer 13), for example via an adjustable pump 14, in accordance with the pressure in the outlet ~` pipeline (which can be read off on the manometer 11).
In order to fill various moulds with reactive resin foam, a flex-ible pressure hose 17 is interposed between the mixing chamber 12 and the orifice valve 16.
A preferred embodiment of the device for carrying out the process according to the invention which can be used is one in which the pressure vessels contain, instead of a gas distributor device, inserts which enlarge the surface and over which the resins flow. The thicluness of the layer will depend on the viscosity of the resin and on the shape of the surface of the inserts being formed under the action of gravity. The resin layer thus formed absorbs the blowing gas so rapidly under the given pressure that the resin which runs off can immediately be withdrawn from the pressure vessel, subjected to pressure release and cured. This embodiment is therefore A

- ~6~96~
most ~uitable for a continuous procedure.
An ~ndustrial apparatus preferred or the continuous manufacturing process is sho~n in simplified representation in Figure 2.
The total apparatus consists of 2 stock v~ssels, 2 pumps, 2 pressure vessels with insertsJ a mixing chamber and one or more gas supply cylinders, for e~ample C02 cylinders. The gas cylinders can aLso be replaced by a suit-able compressor, In the stock vessel 1 there is a foamable reactive resin, preferably an unsaturated polyester resin, in which a curing agent is dissolved. In vessel 2 there is a corresponding resin in which an accelerator is dissolved or incorporated. Both resins are brought to a relatively high pressure in pumps. The pumps which can be used for this purpose are all customary types of pumps suitable for conveying such viscous organic substances and at the same time capable of building up a sufficiently high pressure.
The resin is conveyed through the pipelines 9 and 10 into the t~o pressure vessels 5 and 6. The pressure vessels 5 and 6 are drawn in more detail in Figure 3. The vessel consists of a pressure pipe with a welded-on base 28 and a flanged lid 29 (Figures 2 and 3~. Connections are provided for the resin (9 or 10) (see Figure 2 and 3~, for the gas (II) and for the pressure relief valve 16 and 17. The insert consists of a distributor bottom 26 and several plates 27 down which the mixture drains. At the bottom, there is an outlet 18 and 19 to which a flexible pressure hose can be connected.
A capacitive probe 2~ and 25 is fitted for the purpose of measuring the level of the contents. The resin passes via pipeline 9 and 10 into the pressure vessels, and runs, if the throughput is low~ as a thin film down the plate nearest the inlet orifice, in -the direction of the bottom.
If the throughput is increased, the end o~ the drain down plate which projects above -the distributor bottom ~orms an overflow weir. Hence an additional thin film forms firs-t on the rear of the ~irs-t drain-down plate and secondly on the front of the next drain~down plate. The second plate end forms the overflow weir if the throughput is increased ~ur~
ther, and so on. On all the we-tted plates, regardless of their total number, practically identical films ~orm in accordance with the resin throughput.
The resin drains down the plates as coherent films and collects, free ~rom bubbles9 at the bottom o~ the particu-lar pressure vessel. The two pressure vessels 5 and 6 are under the same static gas pressure which is ad~usted9 ~or ; example~ by means of the gas stock cylinder or cylinders (8) and reducing valve (14), via the shared feed pipeline (11).
me pressure o~ the gas can be read off on the manome~er (15~.
A safety valve (16/17) is mounted on each o~ the pressure~
vessels. The pressures in the vessels can be read o~ on the manometers 12 and 130 The resin solutions which have been enriched with gas~
or saturated with gas, depending on the pressure, leave the pressure vessels through the pipelines 18 and 19 and pass~ o a mixing cell (7) in which the two components mix thoroughly, The pressure is released by means of the mQnually electrically or pneumatically actuated valves 20 and 1, via the mixing passages, ~or example down to normal atmospheric pressure, resulting in the ~ormation of the ~oam~ ~
30I~ the valve~ 20 and/or 21 are closed~ ~le resin level ;
in the pressure vessels 5 and/or 6 rises until~ for example, a ,, , ., , . i ~6)6~969 capacitive level measuring prohe 24 and/or 25 responds and closes the solenoid valves 22 and/or 23. As a result, the pressure in the pipeline 9 and/or 10 upstream from the solenoid valve rises to the point that the pressure relief device of the pumps 3 and/or 4 responds and interrupts the feed. If the valve 20 and/or 21 is opened, the resin level in the pressure vessels drops corres-pondingly and the valve 22 and/or 23 opens. The pump 3 and/or 4 restarts.
~ n principle there are, of course, two possible methods of curing:
1. In the case of a long pot life, the curing agent ~optionally together with accelerator) can already be added to the reactive resin or con-densation resin in the pressure vessel.
lQ 2. In the case of a short pot life it is advisable to divide the total system into two non-curing components and only to mix these shortly before the pressure is released. Thus, for example, in the case of the polyurethane intermediates it is possible to enrich, on the one hand, the polyol component, and on the other, the polyisocyanate component, with gas in accordance with the process of the invention, and then to combine the two components and release the pressure.
Examples:
In the processes of the examples which follow, the temperature was in each case 22C.
Example 1:
Process using the device according to Figure 1 (volume of pressure vessel: 2,000 cm3, charge volume 1~600 cm3).
Example 1.1:
An unsaturated polyester resin was prepared from 0.496 mol of maleic anhydride, 0.504 mol of phthalic anhydride and ~LQ6~969 1.066 mol of 1,3-butanedlol by polycondensation in a known manner at 100-200C until an acid number ~30 was reach0d, and was then stabilised with 0.01~ o~ hydroquinone, dlluted wlth styrene t~ a viscosity of 3,000 cP and pretreated with an accelerator b~ adding 2.5% by weight, relative to the total solution, of bis~ hydroxypropyl)-p-toluidine polyadipate.
1% by weight of organopolysiloxane/polyalkylene oxide copolymer and 2% by weight of a 50/0 strength by weight solu-tion of the sodium salt o~ sulphonated castor oil in distilled water were added to this solution. Curing was carried out in a known manner with 3.6% by weight of a commercially available benzoyl peroxide dispersion (40% strength by weight in dioctyl phthalate). The peroxide was added after the gas-enriched mixture issued from pipe 10 (Figure 1).
Blowing gas: carbon dioxide Pressure Residence time fl. foam a~ter pressure [bars] [mins]release~ density [g/l~

~ 10 20 365 3~ 20 95 225 ~ -170 ; ~
.
~120 ~ 80 9-~

\

:~Q~l969 ~ .
The resin employed was the polyester resin described under 1.1:
Blowing gas: air 5 Pressure Residence time Density Cbars] [mins] [g/l]
.

, The fluid as yet uncured foam only collapsèd after 120 - 240 minutes.
15~ a~ 3 ~
The resin employed was the polyester resin descr1bed:
under 1.1.
~lowing gas: nitrogen :
Pressure Residence time Density ~bars] [mins] ~ ~g/l]
. .:
` 170- 30 ~ 600 . ~:
.
~ 170 60 . `600 `:~:
.
170 ~120 400 :: :
` Ex~ele 1.4~
- . . .
` The resin employed was the polyester resin d~cri~d under l o l ~
Blowing gas: helium . Pressure Residence time~ Density ~bar3~ [mins~ ~g/l~
.
100 120 7~0: .
: 100 2~0 660 ~` ~
,~
~ 3~_2~Q : 3 - ~ ~
' .: . .

' lV6~g69 Exa~mple 1.~
The resin employed was the polyester resl~ described under 1.1.
Blowing gas: di~luoromonochloromethane Pressure Residence time Density [bars] [mins~ [g/l~
____ Foams were prepared in accordance with Examples 1.2, 1.3 ana 1.4 from the polyester resin according to Example 1.1, but initially without added peroxide~ After releasing the pressure, benzoyl peroxide paste, to correspond to Example 1.1, was added to the fluid foam by stirring-in.
Surprisingly; it was found that in spite of th~ mecha-nical stirring-in the fine foam structure remained pre~erved until the reactive~resi~ gelled.
~ea~ : ' , A polyester resin accordi~g to Example l.l, but with-out added amine and instead with 0.03% by weight~ relatlve to "metallic cobalt (in the~orm of cobalt naphthenate) and PE
resin" and with 3% by weight of methyl ethyl ketone peroxide~
(50% strength by~weight in dimethyl phthalate) was ~oamed ~, ~
analogously to Examples l.l to 1.6. me gelling time wa~ 7 25 minutes depending on the blowing gaa and on the density o~the foam.

me resin employed was the poly~ster re~in according~
to Example 1.1. 80 parts by wei~ht, relative to 100 parts 30 ~by weight o~ rea~tive resl~, o~ a talc o~ p~rt~cl~3iY-~ pre-aomi~antly 20 - 150 ~m were added to ~he resi~. me foamin,~

.. .
. ~ "

6~ 9 was carried out analogously to Example 1.1.
Blowing gas: carbon dioxide Pressure Residence time Density [bars] ~mins~ [g/l]

~ .
Foams were prepared ~rom a polyester resin according to Example 1.1, analogously to Example 1.6. The ~oams were combined with a lightweight filler (expanded gas, particle size 10-~0 mm, with densities o~ 150-180 kg/cm3) by mixing-in.
The overall density of the resulting ~oam lightweight concrete was 400-900 g/l Example 1.10:
3% by weight of benzoin isopropyl ether were added to the polyester resi~ according to Examplç lol~ but without .
added amine and without added peroxide. The uncured ~oam waæ
kni~e-coated, as a layer approx. 15 mm thick? onto a plane base~ covered with polyester ~ilm and exposed to superaoti~lc fluorescent lamps with a high proportion of UV light ~365 ~m) at 10 cm distance for 20 minute~ at 40C. The resulting ~oa~
.
slab showed a strohg integral ~tructure ef~ect and had a den-sity of~llO g/l.
Ex~ _3:
A polye~ter resin according to Example 1.1, but with-out peroxide, was treated ~or Z0 hours in ~he device accordlng to Figure 1, at 6 bars carbon dioxide pressure. me reactive~
resin/gas mixture was trans~erred into a 1 1 spray can and the pressure was released after 1 week. Den ity 180 g/l.
~ ~
The polyester resin according to Example 1~10 was treated analogously to Example 1.11.
The reaction mixture was transferred into a spray can and the pressure was released not earlier than the next day.
The curing can be effected as described :in 1.10, with superactinic fluorescent lamps or other lamps which emit light of high UV content.
Example 1.13:
A reactive resin according to Example 1.1 was foamed at 50 atmos-pheres gauge after a dwell time of 20 minutes.
The foam was introduced by means of a perforated lance of rigid PVC
into moulds which were first filled with cellular glass of particle size 10 ~
30 mm. The mould size was 40 x 25 x 10 cm. The resulting rigid foam compo-site material had a density of 225 g/l.
Exam~le 2:
Continuous manufacture of insulating materials from reactive resins:
Exam~le 2.1:
A polyester resin according to Example 1.1 is introduced into the vessel 1 (Figure 2), but without amine, and commercially available benzoyl peroxide paste ~50% strength in dioctyl phthalate) is added in a known manner.
The weight ratio of peroxide to reactive resin was 3:100.
In vessel 2, accelerator is added beforehand, in a known manner, to a reactive resin corresponding to Example 1.1, by using 5 parts by weight of a 10% strength by weight solution of bis~~~hydroxypropyl)~p~toluidine polyadipate per 100 parts by weight of resin.
Viscosity of the resin: 2,600 cP ~adjusted by means of additional styrene).
C2 pressure in the pressure vessels: 45 bars.

~33~

~Qt6~9~i9 Throughput: 1 kg/minute.
Mixing zone and valves (see Figure 2), 7, 20 Qnd Zl:
two-component high pressure spray gun or casting gun as used in the lacquering trade.
Temperature: 22C~
Foam a~-ter release of pressure:
Density: 110 g/l Time up to ~ell m g of the foam: 5 minutes 30 seconds.
Example 2.2.
An unsaturated polyester was prepared ~rom 0.83 mol of maleic anhydrlde, 0.17 mol o~ phthalic anhydride, 0.851 mol of 1,2-propanediol and 0.269 mol o~ dipropylene glycol by polycondensation until an acid number of Z8 was reached. The polyester was diluted with styrene to give a 65~o strength by ; 15 weight solution and this solution was stabilised w~th 0.012%
by weight of hydroquinone~.~ me curing agent and accelerator were added as in Example 2.1. ; me polyester solution was then diluted to the viscosities lndicated below by ~u~ther addition~of st~ ene.
Mixing z~n~s and val~eso see Figure 2: 7, 2Q a~d 21 two-component high pressure spray gun or oas~ing gun as used in the lacquering~trade.
; ~ Time up to g~lling 6~- 10 minutes.
Visooslty: ~1,200 mPas 25C02 pressure Thr~ughput~ Dens~ty 25 ~ 205 ~180 ; 30 ~1.4 ~ 12~ ~
~ 1.4 1 115 , . : - ~ . .
Vi oo~ity: 1,200 mPas ,;, ~ . . . ' :
~ L}~ 34 ~ ~

61~69 , C2 pres~ure l~roughput Density [bars] [kg/min] ~kg/m33 ~ . .
4 .165

2 . 7 100

3.1 95 Viscosity: 800 mPas:
C2 pressure mroughput Density Cbars~ [kg/min] [kg/m3] ~:
2 . 3 ~ 114 . : .
3 92 . 5 ~ :
~, 3 100 Example 2 . ~_ Vessel 2 contains a reactive r~sin analogous to Example 2 . 2 .
The apparatus is charged~ ~under the same co~di-tion3 described in Ex~mple:202, but the ga~/reaction mixture i~
injected near the bottom o~ a mould o~ size 40 x 25 x: 10 c~ ~ .
whlch has been fllled with oellular ~lass o~ 10 x 30 ~ par- :
~: ~ ticle size, the :~pressllre ls released, and the mixture i8:` c~d.
. 20 YLsoo~ 1, 200 mPa~
C2 pressure ~ mroughput ~ ~ Densit~ Bind~r requir~d . [bars] ~ ~kg/min] ~ [kg/m33 ~k~/m3~
: . ., . , ~ . .
: - 30 ~ 1 . 7 ~: 286 . lli~ ~ .
~ 40 ~ :1.9 266 92`
Yiscosity: 1~000 mPa~
-C02 pressure ~oughput Density ~ r- re~:red .. ~bars~ Ekg/min}: ~kg/m3] ~k~/m3}~
.
~~ 1.2 2~ 10~
~ .8 265~ 91 ~:
~ 2~.5 ~ ~ 258 ~4 ~ ~ -Visooslty 800 mPas ~ -:, : .

,,9~;~
C2 pressureThroughputDensity Binder required [bars~ Ckg/min] Ckg/m3] [kg/m3]
1.8 265 91 1.~ 262 88 3.8 274 100 , . . ~ , ~ : .
, : .
, ~ , .
.

' .

. . .
.
, ' ' , ' ~ ' ~ :
' ' ' ' ' :'.
- ' , ~ .
i ' ' .
~ 36 -' ' - '

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process of manufacturing foamed materials from a liquid thermosetting resin having a viscosity less than 6000 cP, comprising the steps of contacting a thin unbroken film of the liquid resin in a pressure vessel under pressure of 3 to 350 bars at a temperature of between 0 to 50°C for a residence time of 0.1 to 120 minutes with a blowing agent having a boiling point under normal pressure which is below 0°C, causing the liquid resin to smoothly flow without absorbing discernible bubbles of the blowing agent down and over an elongated surface means having a vertical component disposed within the pressure vessel whereby the liquid resin film absorbs the blowing agent so rapidly that the resin film flowing off from the elongated surface means can immediately be withdrawn from the pressure vessel, deposited on a surface, subjected to pressure release, allowed to expand and to cure into a foamed resin.

2. The process of claim 1 wherein the liquid resin con-tacted in said pressure vessel contains at least one member selected from the group consisting of curing agents, accelerators and fillers.

3. The process as set forth in claim 1, wherein the liquid resin is caused to flow over a series of vertically disposed smooth plates in the pressure vessel by disposing the series of plates vertically in the pressure vessel with their upper ends passing through substantially closed apertures in a horizontal distributing bulkhead, the upper ends of the plates constituting overflow weirs within the pressure vessel, the liquid resin being supplied in front of the first overflow weir whereby liquid film first flows down the front and then the back surfaces of the first plate and thereafter down the following front and back sur-faces of successive plates as the liquid resin builds up on the bulkhead and flows successively over each of the weirs.