CA1277999C - Hydraulic cement additives and hydraulic cement compositions containing same - Google Patents
Hydraulic cement additives and hydraulic cement compositions containing sameInfo
- Publication number
- CA1277999C CA1277999C CA000553741A CA553741A CA1277999C CA 1277999 C CA1277999 C CA 1277999C CA 000553741 A CA000553741 A CA 000553741A CA 553741 A CA553741 A CA 553741A CA 1277999 C CA1277999 C CA 1277999C
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- Canada
- Prior art keywords
- composition
- weight
- ethylenically unsaturated
- graft copolymer
- monomer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B24/2652—Nitrogen containing polymers, e.g. polyacrylamides, polyacrylonitriles
- C04B24/2658—Nitrogen containing polymers, e.g. polyacrylamides, polyacrylonitriles containing polyether side chains
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B24/2641—Polyacrylates; Polymethacrylates
- C04B24/2647—Polyacrylates; Polymethacrylates containing polyether side chains
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
Abstract
ABSTRACT OF THE DISCLOSURE
Hydraulic cement compositions are disclosed containing a hydraulic cement and a graft copolymer, the graft copolymer containing a polyether backbone and side chains prepared by polymerization of an ethylenically unsaturated monomers. The graft copolymer functions as a plasticizer in the cement composition.
Hydraulic cement compositions are disclosed containing a hydraulic cement and a graft copolymer, the graft copolymer containing a polyether backbone and side chains prepared by polymerization of an ethylenically unsaturated monomers. The graft copolymer functions as a plasticizer in the cement composition.
Description
~ -1~77999 66925-368 Thl~ invention provlde~ a compo6ition comprising a hydraul~c ce~ent and a graft copolymer pla~ticlzer for said cement, said graft copolymer co~prising a polyether backbone polymer and ~lde chaln polymer~ prepared by poly~erization of an ethylenically unsaturated mono~er.
~he use of various additives to increase the fluidity of hydraulic cement compositions has been a common practice for many years. These additives fluidify or plasticize the cement composition such that a more fluid composition is obtained at a 1n given water to cement ratio or, alternatively, a lower water to cement ratio may be u8ed to obtain a compo8ition having a desired consistency. The lower water to cement ratio normally results in a higher compressive 8trength in the hydrated cement after setting.
The present invention is directed to the use of a new class of plasticizing additives for hydraulic cement compositions and to hydraulic cement compositions containing the inventive additives. According to this invention, it has been found that graft copolymers can be used as water reducing admixtures and superplasticizers for hydraulic cement concretes, mortars, grouts, and the like. It has also been ound that certain graft copolymer~ can function a~ water reducing admistures and superplasticizers at low dosages while providing only small increases in the setting time of the cement composition, as compared to the setting time increases imparted by known water reducing admistures and superplasticizers at comparable levels of water reduction.
The graft copolymers o the invention are capable of functioning as water reducing admixtures or superplasticizers, 3q depending on the nature of the copolymer and the amount added to the cement compositions. ~Water reducing admixture~ and ,`s~'s ll case 2s38c ~77~9~
"superplastizer~ are terms of art which reference the relative water-reducing ability of a material. water reducing admixtures provide a water reduction capability of 5% to 12%
(ASTM-C-494, Type A or Type D), while superplasticizers provide water reduction in excess of 12% (ASTM-C494, TYPe F or G).
For brevity and convenience, the graft copolymers of the invention are referred to herein as plasticizers. This term includes, however, both water reducing admixtures and super-plasticizers, as defined immediately above.
Graft copolymers, as a generic class of materials, are well ~nown in the chemical art. These polymers are comprised of a base or ~backbone~ polymer chain to which side chain polymers are attached at various points. The side chain polymer has a different chemical structure than the backbone polymer, i.e., comprises different monomers or a different combination of monomers. The graft copolymer plasticizers of this invention comprise a polyether backbone having attached side chain polymers formed by polymerization of eth~ylenically unsaturated monomers. The attachment of the side chain polymer provides a graft copolymer that has a greater plasticizing capability than the polyether backbone itself. As a practical matter, the requirement that the side chain enhance the plasticizing capability of the polyether will determine which ethylenically unsaturated monomers may be used to form the side chain. In general, one class of monomers which can be used to form the side chain polymers are the ethylenically unsaturated monomers which have been used previously to form plasticizing homopolymers and copolymers, and which can be grafted onto polyetheL~ . A~ LU~ ~her discussed herein, many of the free, Case 2938C ~ 77 ~99 non-grafted polymers formed from such monomers, while providin~
a desired level of plasticization, also result in undesirable increases in the setting time of the cement composition, or have other undesirable performance characteristics. According to this invention, use of polymeric units formed from such monomers as grafted side chains may serve to minimize such undesirable performance, while still yielding a polymeric product providing the desired level of plasticization.
As used herein, "polyether~ means any homopolymer or copolymer which is capable of undergoing grafting with ethylenically unsaturated monomers and has repeating units containing the carbon-oxygen ether linkage. The polyethers thus have repeating units of the formula -(0-R-) wherein R is an organic moiety containing a carbon atom linked to the oxygen through a single covalent bond. The polyether may contain two or more different repeating units containing different R
moieties. One or more of the repeating ether units may contain one or more carbon atoms which can function as grafting sites, e.g., by undergoing hydrogen or halogen abstraction. In general, the provision of grafting sites in the R moiety is preferred, although such sites may additionally or alternatively be provided by other groups or atoms which may be present in the polyether.
R may be an arylene group, e.g., phenylene, provided that other groups or moieties are present in the polymer which provide grafting sites; a divalent alkylaryl group wherein one of the alkyl carbon atoms is linked to the oxygen, e.g., -CH2-CH2 ~ ,-cH2-cH(cH3)-cH2 ~ ; a saturated cyclic group, e.g., cyclohexylene; or a saturated or ase 2938C
case 2938C ~7~ggg unsaturated, substituted or unsubstituted aliphatic group.
Saturated aliphatic groups are preferred, particularly alkylene groups such as ethylene, propylene, butylene, isopropylene, or isobutylene. The preferred polyethers for use in the invention are accordingly polyoxyalkylenes, e.g., polyoxyethylene homopolymers, polyoxypropylene homopolymers, and oxypropylene/oxyethylene copolymers. Polyoxyalkylenes are well known and a variety of such polymers are commercially available. Commercial polyoxyalkylenes which may be used in this invention include those sold under the Pluracol, Tetronic, and Pluronic tradenames by BASF Wyandotte Corporation and under the Jeffamine and Thanol tradenames by Texaco Inc. The polyethers may include reactive groups, e.g., amino, carboxyl, or hydroxyl groupB~ positioned at the end of the polymer or at intermediate points along the polymer chain. If desired, these groups may be derivatized before or after grafting of the side chain. Preferred polyoxyalkylenes, for example, include terminal hydrosyl groups arising from polymerization of the corresponding alkylene oxide. These hydroxyl groups may remain unreacted or may be derivatized before or ater grafting of the side chain to provide, for example, urethane or ester derivatives.
The average molecular weight of the polyether backbone is preferably within the range of about 200 to 30,000, and more preferably is in the range of about 500 to 10,000. The average molecular weight of the graft copolymers of the invention is preferably less than about 50,000. As used herein, the term ~average molecular weight~ refers to the number average molecular weight of the polymer as determined ~ G~ pcrmeation chromatography using a suitable solvent for the polymers, such as water, tetrahydrofuran, or N,N-dimethylformamide, and polyacrylic acid, polystyrene, or polyethylene oxide as a standard.
Case 2938C ~ 77 ~9~
As iS generally the case with cement water reducing admixtures and superplasticizers, the graft copolymers of this invention should be water dispersible or water soluble. Thus, the graft copolymer should be dispersible or soluble in a 100%
water medium or an aqueous medium comprised principally of water, e.g., an aqueous alcohol medium containing a minor percentage of alcohol. The pH of the medium may be adjusted as necessary to obtain or optimize dispersibility or solubility.
Where the polyether backbone is a relatively l~ hydrophobic material, such that it has low water dispersiblility or solubility, an appropriate side chain which imparts the desired solubility or dispersibility is grafted to the polyether. Side chains used for this purpose should accordingly be more hydrophilic than the polyether backbone.
Preferred side chains, from the standpoint of promoting water dispersibility and s~lubility, are those which contain salt-forming groups. The salt-forming groups may be provided by homopolymerizing or copolymerizing ethyler.ically unsaturated , monomers containing an acid group, such as acrylic acid, methacrylic acid, or 2-sulfoethylmethacrylate, to form the side chain. Alternatively, monomers may be used which contain precursors which can be reacted after graft polymerization to provide a salt-forming group, e.g., maleic anhydride may be incorporated into the side chain and subsequently hydrolyzed to the acid form. In general, the acid group is converted after grafting to its salt form by neutralization with a base. The salt-forming groups may also be provided by monomers containing a quaternary ammonium group or an amine group which can be guaterniz a~tor polymerization Case 2938C
~ ~ 7~ 99~3 The ethylenically unsaturated monomers used in the invention are polymerizable monomers characterized by the presence therein of at least one polymerizable ethylenic unsaturated group of the structure ~C=C~ . Any such monomer which can be grafted onto a polyether to provide a graft copolymer having a greater plasticizing capability than the polyether, and which permits water dispersibility or solubility of the graft copolymer, can be used in this invention. The monomers can be used singly or in combination to produce homopolymer or copolymer side chains. Examples of ethylenically unsaturated monomers which can be used are the a, ~-ethylenically unsaturated acids, e.g., acrylic acid, methacrylic acid, and itaconic acid; the ~ ,~ -ethylenically unsaturated acid esters, e.g., methyl acrylate, methylmethacrylate, ethylacrylate, 2~hydroxy- propylacrylate, 2-hydroxypropylmethacrylate, 2-hydroxyethylmethacrylate, 2-hydroxyethylacrylate, 2-sulfoethylmethacrylate, 3-sulfopropylmethacrylate, bis-(3-sulfopropyl)itaconate, 2-phenoxyethylacrylate, tetra-hydrofurfurylacrylate, cyclohexylmethacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, and caprolactone acrylate monomere such as Tone M-lO0 monomer of Union Carbide Corp.;
the a, ~ -ethylenically unsaturated acid amides, e.g., acrylamide, methacrylamide, diacetone- acrylamide, dimethylaminopropylmethacrylamide, and 2-acrylamido-2-methylpropane sulfonic acid; ethylenically unsaturated acids and acid esters of the formula (I) CH2 = C - (C)n - COOR4 (I) 30 ~ R3 ~ Case 2938C
... , ~.2779g9 wherein Rl, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters such as vinyl acetate; vinyl ethers; vinyl ketones; vinyl aromatic monomers such as styrene and styrene sulfonic acid; N-vinylpyrrolidone;
polymerizable acid anhydrides such as maleic anhydride and itaconic anhydride; aminoalkylacrylate and methacrylates, e.g., dimethylaminoethyl acrylate and diethylaminoethyl methacrylate;
betaines such as N-t3-sulfopropyl)-N-methacrylosyethyl-N,N-dimethylammonium betaine and 1-(3-sulfopropyl)-2-vinyl pyridinium betaine; and cationic guaternary ammonium monomers such as the quaternized aminoalkyl acrylates and methacrylates. The , ~ -ethylenically unsaturated acids are preferred monomers for use in this invention.
It should be understood that, depending on the nature of the monomer, single monomeric units may become grafted onto the polyether backbone. In particular, monomers conforming to the above formula ~I) may graft in this manner. Accordingly, as used herein, the term ~side chain~ and ~side chain polymer~
broadly include and refer to grafted moieties comprised of a 2~ single monomeric unit. Similarly, reference herein to the polymerization of ethylenically unsaturated monomers broadly include8 the grafting of single monomeric units onto the polyether backbone A generally useful amount of monomer or mixture of monomers for preparing the side chain polymers is within the range of about 5% to 50% by weight, based on the combined weight of the monomer(s) and polyether. Normally, it is preferred to use an amount of monomer which, on average for a number of diE~erent cements, provides a high degree of Case 2938C ~7799~
plasticization, balanced by minimization of any undesired effects which might occur in the hydraulic cement composition.
In addition, the amount of monomer may depend on obtaining a desired water dispersibility or solubility, e.g./ it may be necessary to use a greater amount of hydrophilic monomer with a relatively hydrophobic polyether backbone.
Particularly preferred copolymers of this invention are those comprising a hydroxyl terminated polyoxyalkylene backbone, most preferably a hydroxyl terminated oxyethylene/
oxypropylene copolymer, and side chains comprising a homopolymer or copolymer of acrylic acid. The amount of acrylic acid used in preparing the side chains is preferably in the range of about 10% to 35~ by weight, based on the combined weight of the polyether and acrylic acid, with a more preferred range being about 15% to 25%. These graft copolymers have been found to function effectively as superplasticizers at low dosages in the range of 0.05% to 0.4% by weight, based on the weight of cement solids, with relatively small aocompanying increases in set retardation and good compressive strengths being obtained.
It should be recognized that the present invention brings to the art the practice of introducing functional polymeric materials into hydraulic cement compositions as grafted side chains. This practice may permit a more advantageous use of certain types of polymeric materials which, as free, non-grafted polymers, are normally not suitable or of limited utility in such compositions. Polyacrylic acid polymers, for example, are known to be superplasticizers but are of ii~ u u~ility in hydraulic cement compositions whicl case 2938C
~ ~ 7 7 99~
must set relatively quickly because they impart excessive set retardation. In this invention, however, a polyacrylic acid can be used as a grafted side chain, providing graft copolymers which are comparable superplasticizers but impart comparatively less set retardation than free polyacrylic acid polymers, at an equivalent slump. Thus, for example, a polyacrylic acid homopolymer and a graft copolymer composition of the invention containing a graft copolymer having polyacrylic acid side chains may be used in amounts which provide equivalent slumps in hydraulic cement concretes but, in general, the concrete containing the graft copolymer composition will have a substantially lower setting time.
The graft copolymers of this invention are prepared by free radical addition polymerization of an ethylenically unsaturated monomer or a mixture of such monomers in the presence of a polyether. Although the radical form of the monomer may be generated thermally, it is usually preferred to include a free radical initiator in the reaction mixture.
The polymerization may be accomplished by procedures known in the art, e.g., emulsion or suspension polymerization, bulk polymerization, or solution polymerization. Generally, it is preerred to employ bulk polymerization when the monomer is miscible with the polyether. However, if necessary, an organic solvent or diluent which does not participate in the polymerization reaction may be used.
In addition to the graft copolymer which is formed, the reaction product of the free radical polymerization will generally also contain one or more by-product constituent materials, e.g., non-grafted addition homopolymeLs of the Case 2938C
~ ~ 77 99g monomer (or copolymers where a mixture of monomers is used), and polyether degradation products. The reaction product mixture may also contain unreacted polyether. These reaction product mixtures may be used as admixtures of this invention without purification or segregation of the species therein.
Accordingly, reference throughout this application to graft copolymers is intended to refer also to these reaction product mixtures.
It should be understood that it is very difficult to 1n analyze accurately for the extent of grafting and the degree of polymerization in the side chain, as well as the amount of graft copolymer formed in proportion to by-product polymers.
These parameters will vary with the polyether and monomers used and their relative amounts, the amount and type of initiator, the rate of mixing of the reagents, and reaction temperatures and times. As indicated above, a generally useful amount of monomer for forming the side chains is about 5% to 50% by weight, based on the combined weight of monomer and polyether.
About 10% to 35% by weight, similarly based, is a preferred amount. It will be appreciated that the percentage by weight of the side chains in the graft copolymer will be less than the percentage amount of monomer charged to the reactor, since part of the monomer charge is consumed in the formation of by-products, such as non-grafted addition polymers. The above given weight percentages of monomers, for example, are believed to provide graft copolymers containîng, respectively, about 2%
to 40%, and preferably about 5~ to 30%, by weight of grafted side chains. These are approximate amounts, however, as a consequence of the indeterminate partial COli~LSiOI~ uE monomer Case 2938C
~ 7~99 to side chain and the difficulity in analyzing the reaction product.
The addition polymerization reaction generally may be conducted at a temperature in the range of about 100C to 180C. A more preferred range is about 130 to 160C.
The reaction time can vary over a wide range depending on such factors as polymerization method, reagent and initiator concentrations, and reaction temperature. For example, in bulk polymerizations at a reaction temperature of 130C to 160C, a reaction time of two to six hours is generally sufficient to deplete all of the monomer charge. In a preferred method of preparation, bulk polymerization is employed with a reaction temperature of about 130C to 160C, with gradual addition of at least part of the monomer, lS e.g., with continuous monomer addition over a one to two hour period. The reaction mixture is maintained at the reaction temperature for about one hour after all of the monomer is added.
At the end of the reaction period, the reaction mixture is worked up as necessary to provide a desired admixture product. The work up r.ormally involves simply adding water or a desired aqueous medium to the reaction mixture to provide a desired solids concentration, followed by pH
adjustment. If an organic solvent or diluent is used during the polymerization it is normally removed prior to the addition of water or the aqueous medium.
The pH is normally adjusted to provide optimum solubility or dispersibility of the graft copolymer. Where salt forming acid groups are present on the polymer, for Case 2938C
_ ~ 77 ~99 example, the pH is usually brought to a level above the PKa of the acid so as to form ionic species.
Free radical initiators which may be used to promote the polymerization reaction include the conventional peroxy and S azo initiators. Exemplary initiators are di-tert-butyl peroxide, benzoyl peroxide, lauroyl peroxide, oleyl peroxide, tolyl peroxide, di-tert-butyl diperphthalate, tert-butyl peracetate, tert-butyl perbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hesyne-3, tert-butyl 1~ hydroperoxide, cumene hydroperoxide, hydroperoxide, cyclopentane hydroperoxide, diisopropylbenzene hydroperoxide, p-tert-butyl cumene hydroperoxide, 2,5-dimethyl-hexane-2,5 dihydroperoxide, etc., and mi~tures thereof. The initiator, when included, is generally in the range of 0.001 to 5.0 percent and preferably on the order of 0.05 to 2.5 percent by weight of the polyether and side chain forming monomers.
It is usually desirable to degas the reaction mixture for a sufficient period of time to remove oxygen from the reaction zone since oxygen inhibits the polymerization 2~ reaction. The degassing can be conveniently accomplished by blowing nitrogen gas through the reactor prior to the polymerization. It is also usually desirable to conduct the polymerization under a continuous nitrogen blanket.
As mentioned previously, the present invention is directed in part to hydraulic cement compositions containing the graft copolymers described above. These compositions comprise a hydraulic cement and a graft copolymer. The term "hydraulic cementN is used herein in its ordinary and well accepted sense, dnd ti.u~ Le;~LS to any cement which, when made Case 2938C
~ 77~3~9 into a paste with water, sets and hardens as a result of chemical reactions between the water and cement. Portland cement is the most familiar example of a hydraulic cement and is the preferred material for use in the cement compositions of the invention. Other hydraulic cements which may be used include aluminous, oil well, slag, pozzolanic, and silicate cements, as well as gypsum and magnesium oxychloride based materials.
The hydraulic cement composition may be in a dry powder form or mixed with water to form a plastic mix. It is generally preferred to add the graft copolymer to the cement in connection with preparation of an aqueous hydraulic cement mix i.e., with the mix water or as an additive to the already formed mix composition. The graft copolymer may, however, be added at an earlier stage, such as during the grinding of clinker to prepare the cement.
The graft copolymer is preferably added to the cement in the form of an aqueous solution or dispersion. Generally, the amount of graft copolymer added is in the range of about 0.0l~ to 0.6% by weight, based on the weight of dry cement in the composition. A more preferred range is about 0.05% to 0.4~.
The hydraulic cement compositions may include other functional additives such as set accelerators and retarders, fluid loss agents, air entraining and detraining agents, and other hydraulic cement plasticizing materials. These additives may be added separately or admixed with the graft copolymer prior to addition to the cement. The compositions may also include any of the aggregate materials commonly used in the ~Lade, e g., sand and stone to form structural concretes and various lightweight aggregates such as vermiculite and perlite.
case 2s38c ~799~
Cement compositions of the invention comprising an air detraining agent may be of particular interest in certain applications. Various commercially available air detraining or antifoaming agents can be employed, including tri-n-butylphosphate, l-octanol, the General Electric antifoaming agents sold as GE AF-60 and GE AF-72, the antifoaming agents sold as Antifoam H-10, Antifoam B, and DB
100 by Dow Chemical Co., the antifoaming agents sold under the Foamaster tradename by Diamond Shamrock, and the antifoaming agents sold under the Surfynol tradename by Air Products &
Chemicals Corp. The air detraining agent can be added to a solution or dispersion of the graft copolymer prior to being added to the cement composition or it may be added separately.
The amount of air detraining agent which is used is normally in the range of about 0,1% to 10% by weight, based on the weight of the graft copolymer. A more preferred range is about 1% to 5% by weight. A decrease in setting time of the cement composition may be attained through use of the air detraining agent with little or no change in the plasticity imparted by 2~ the graft copolymer.
The following Examples further describe and illustrate the invention, but are not intended to limit the scope thereof.
Unless otherwise indicated, all parts and proportions are by weight.
~ graft copolymer of acrylic acid and an oxyethylene/oxypropylene copolymer was prepared by the foiLowirly procedure.
case 2938C
~ 77 999 A mixture of 20.0 grams of acrylic acid and l.o gram of tert-butyl perbenzoate was added over a one hour period to 80.0 grams of a hydroxyl terminated oxyethylene/ oxypropylene copolymer sold under the tradename Pluracol-W5100N by BASF
Wyandotte Corporation ~average molecular weight of about 4600) at 145C under nitrogen. After the addition was completed the reaction mixture was maintained at 145C for an additional hour. The reaction mixture was then added to a mixture of 130 qrams of water and 9 grams of sodium hydroxide resulting in a homogeneous solution. The solids concentration in ~he solution was measured to be about 42~ and the pH was about 9Ø
A graft copolymer solution was prepared by the procedure of Example 1 using 75.0 grams of Pluracol W5100N, 25.0 grams of acrylic acid, and 2.0 grams of tert-butyl perbenzoate.
A graft copolymer solution was prepared by the procedure of Example 1 using, as the polyether bac~bone, a hydroxyl terminated oxyethylene/oxypropylene copolymer sold by A BASF Wyandotte Corp. under the tradoname Pluracol W170, having an average molecular weight of about 800. Thus, 80.0 grams of Pluracol W170, 20.0 grams of acrylic acid and 1.0 gram of tert-butyl perbenozate were reacted according to the procedure of Example 1 and the reaction pLOdUC~ rleutralized and diluted as in that Example to produce a solution with a measured solids content of about 42%.
Case 2938C ~7999 A graft copolymer solution was prepared b~ the procedure of Example 1 using, as the polyether backbone, a .. hydroxyl terminated polyoxyethylene sold by Union Carbide Corp.
~A ~ fra~6~
lY~ under the ~r~dcnamc Carbowax 6000. Thus, 150.0 grams of Carbowax 6000, 50.0 grams of acrylic acid, and 3.0 grams of tert-butyl perbenzoate were reacted as described in Example l and the reaction product neutralized and diluted as in that Example to produce a solution with a measured solids content of about 42%.
The graft copolymer solutions prepared in Examples l through 4 were added to concretes prepared using a Type I
Portland cement, sand aggregate, and a water to cement ratio of 0.49. The concretes were mixed for about one minute prior to addition of the copolymer solutions. A sufficient amount of solution was added to provide a graft copolymer concentration of 0.1%, based on the weight of Portland cement in the concretes. (In this and the following Examples 7, 8, and 9, 2~ the amount of graft copolymer added to the concrete is expressed as a percentage of the Portland cement in the composition. This percentage was calculated assuming that lO0 of the solution solids was graft copolymer.~
A reference concrete was prepared in an identical manner, except that the addition Ol grd~t copolyrner solution case 2938c ~7999 was omitted. The slumps of the concretes were measured in accordance with ASTM C143 at about 11 minutes into the mix cycle (10 minutes after addition of the graft copolymer). The initial setting times of the concretes were also measured, in accordance with ASTM C403. The measured results are presented in Table 1, wherein the concretes are designated numerically in correspondence with the graft copolymer solution added from the above Examples.
l~ Concrete Slump ~in.~Initial Settina Time(hr:min~
Reference 3.25 3:40 1 6.75 5:02 2 7.50 5:14 3 6.00 5:11 4 6.25 4 57 A graft copolymer solution was prepared by the procedure of Example 1 using, as the polyether backbone, a hydroxyl terminated polyoxypropylene sold by BASF Wyandotte 2~ Corp. under the tradename Pluracol P 4010, having an average molecular weight of about 4000. Thus, 170.0 grams of Pluracol P 4010, 30.0 grams of acrylic acid, and 1.0 gram of tert-butyl perbenzoate were reacted according to the procedure of Example 1 to prepare a solution with a measured solids content of about 42%.
The graft copolymer solution of Example 6 was added to a concrete prepared using the Type I Portland cement of Example 5, sand aggregate, and a water to cement ratio of 0.49. A
Case 2938C
~,77~
sufficient amount of the solution was added to provide a graft copolymer concentration 0.10%. The time of addition was as in Example 5 and slump and setting time measurements were then made, also as in Example 5, and compared with a reference concrete containing no graft copolymer solution. The slump and setting time of the reference concrete were 3.5 inches and 4:11 while the concrete containing the graft copolymer solution had a measured slump of 6.1 inches and a setting time of 4:49.
To 81 grams of a 42% solids solution of a graft copolymer of acrylic acid and Pluracol W5100N, prepared . according to the procedure of Esample 1, was added 0.35 gram of A tri-n-butyl phosphate (TN~P). Similarly, 0.35 gram of Surfonyl 440 air entraining agent of Air Products & Chemicals Corp. was added to 81 grams of the graft copolymer solution. The resultant solutions were added to concretes prepared using a Type I Portland cement, sand aggregate, and a water to cement ratio of 0.81. The cement factor was 400 lbs./yd. The amount of solution added provided a concentration of graft copolymer 2~ of 0.2%. The solutions were added, and slump and setting times measured, as in Example 5. The compressive strengths were also measured, in accordance with the procedure of ASTM C192. For comparison, two concretes were prepared similarly except that in one concrete the graft copolymer solution alone was added and in the second concrete neither the graft copolymer solution nor an air detraining agent was added. The measured results ~ a ~ ~a~ -18-Case 2938c ~ 799~
are presented in Table 2.
Initial Setting Slump Time Concrete Admixture ~in.) % Air (hr:min) Compressive Strenqth(PSI) Graft Ai r Copolymer Detraining Conc. Aqent 1 day 7 day 28 day - - 2.5 2.5 4:34719 1610 3033 0.2 - 7.50 6.2 6:10643 1752 2~32 0.2 TNBP 7.25 3.8 5:34675 1887 2827 0.2 Suronyl 7.00 3.9 5:30705 1765 2627 The results presented in Table 2 illustrate that air detraining agents can be used to reduce setting time and increase compressive strength without significantly altering the slump increase caused by the graft copolymer.
EXAMP~E 9 To evaluate the water reducing capability of the graft copolymer solution of Example 1 and the effect of water reduction on compressive strength, the solution was added in different amounts to batches of a concrete prepared using a Type I Portland cement and a cement factor of 611 lbs./yd. The water to cement ratio (W/C) was adjusted in each case to provide approximately equivalent slumps which, in turn, were about e~ual to that of a control sample which was prepared without addition of the graft copolymeL ~iU~ dlld W/C of Case 2938C
~ 999 0.50. The control thus provided the basis for determining the degree of water reduction and strength improvement. The measured results are presented in Table 3.
Table 3 Graft Initial Copolymer Slump Setting 28 Day Compressive ~ncentration ~ (in.~ Time(hr:min~ Strenath (psi~
Control 0~50 2.63:59 6358 0.125 0,47 3.24:1S 6764 0.20 0.45 3.04:19 7551 0.30 0.42 2.64:41 7811 0.50 0.40 2.94:58 8301 The results illustrate the substantial water reducing capability of the inventive admixture (up to 20% at the higher dosages) with substantial accompanying increases in compressive strength. Relatively minimal setting time increases were also observed.
~he use of various additives to increase the fluidity of hydraulic cement compositions has been a common practice for many years. These additives fluidify or plasticize the cement composition such that a more fluid composition is obtained at a 1n given water to cement ratio or, alternatively, a lower water to cement ratio may be u8ed to obtain a compo8ition having a desired consistency. The lower water to cement ratio normally results in a higher compressive 8trength in the hydrated cement after setting.
The present invention is directed to the use of a new class of plasticizing additives for hydraulic cement compositions and to hydraulic cement compositions containing the inventive additives. According to this invention, it has been found that graft copolymers can be used as water reducing admixtures and superplasticizers for hydraulic cement concretes, mortars, grouts, and the like. It has also been ound that certain graft copolymer~ can function a~ water reducing admistures and superplasticizers at low dosages while providing only small increases in the setting time of the cement composition, as compared to the setting time increases imparted by known water reducing admistures and superplasticizers at comparable levels of water reduction.
The graft copolymers o the invention are capable of functioning as water reducing admixtures or superplasticizers, 3q depending on the nature of the copolymer and the amount added to the cement compositions. ~Water reducing admixture~ and ,`s~'s ll case 2s38c ~77~9~
"superplastizer~ are terms of art which reference the relative water-reducing ability of a material. water reducing admixtures provide a water reduction capability of 5% to 12%
(ASTM-C-494, Type A or Type D), while superplasticizers provide water reduction in excess of 12% (ASTM-C494, TYPe F or G).
For brevity and convenience, the graft copolymers of the invention are referred to herein as plasticizers. This term includes, however, both water reducing admixtures and super-plasticizers, as defined immediately above.
Graft copolymers, as a generic class of materials, are well ~nown in the chemical art. These polymers are comprised of a base or ~backbone~ polymer chain to which side chain polymers are attached at various points. The side chain polymer has a different chemical structure than the backbone polymer, i.e., comprises different monomers or a different combination of monomers. The graft copolymer plasticizers of this invention comprise a polyether backbone having attached side chain polymers formed by polymerization of eth~ylenically unsaturated monomers. The attachment of the side chain polymer provides a graft copolymer that has a greater plasticizing capability than the polyether backbone itself. As a practical matter, the requirement that the side chain enhance the plasticizing capability of the polyether will determine which ethylenically unsaturated monomers may be used to form the side chain. In general, one class of monomers which can be used to form the side chain polymers are the ethylenically unsaturated monomers which have been used previously to form plasticizing homopolymers and copolymers, and which can be grafted onto polyetheL~ . A~ LU~ ~her discussed herein, many of the free, Case 2938C ~ 77 ~99 non-grafted polymers formed from such monomers, while providin~
a desired level of plasticization, also result in undesirable increases in the setting time of the cement composition, or have other undesirable performance characteristics. According to this invention, use of polymeric units formed from such monomers as grafted side chains may serve to minimize such undesirable performance, while still yielding a polymeric product providing the desired level of plasticization.
As used herein, "polyether~ means any homopolymer or copolymer which is capable of undergoing grafting with ethylenically unsaturated monomers and has repeating units containing the carbon-oxygen ether linkage. The polyethers thus have repeating units of the formula -(0-R-) wherein R is an organic moiety containing a carbon atom linked to the oxygen through a single covalent bond. The polyether may contain two or more different repeating units containing different R
moieties. One or more of the repeating ether units may contain one or more carbon atoms which can function as grafting sites, e.g., by undergoing hydrogen or halogen abstraction. In general, the provision of grafting sites in the R moiety is preferred, although such sites may additionally or alternatively be provided by other groups or atoms which may be present in the polyether.
R may be an arylene group, e.g., phenylene, provided that other groups or moieties are present in the polymer which provide grafting sites; a divalent alkylaryl group wherein one of the alkyl carbon atoms is linked to the oxygen, e.g., -CH2-CH2 ~ ,-cH2-cH(cH3)-cH2 ~ ; a saturated cyclic group, e.g., cyclohexylene; or a saturated or ase 2938C
case 2938C ~7~ggg unsaturated, substituted or unsubstituted aliphatic group.
Saturated aliphatic groups are preferred, particularly alkylene groups such as ethylene, propylene, butylene, isopropylene, or isobutylene. The preferred polyethers for use in the invention are accordingly polyoxyalkylenes, e.g., polyoxyethylene homopolymers, polyoxypropylene homopolymers, and oxypropylene/oxyethylene copolymers. Polyoxyalkylenes are well known and a variety of such polymers are commercially available. Commercial polyoxyalkylenes which may be used in this invention include those sold under the Pluracol, Tetronic, and Pluronic tradenames by BASF Wyandotte Corporation and under the Jeffamine and Thanol tradenames by Texaco Inc. The polyethers may include reactive groups, e.g., amino, carboxyl, or hydroxyl groupB~ positioned at the end of the polymer or at intermediate points along the polymer chain. If desired, these groups may be derivatized before or after grafting of the side chain. Preferred polyoxyalkylenes, for example, include terminal hydrosyl groups arising from polymerization of the corresponding alkylene oxide. These hydroxyl groups may remain unreacted or may be derivatized before or ater grafting of the side chain to provide, for example, urethane or ester derivatives.
The average molecular weight of the polyether backbone is preferably within the range of about 200 to 30,000, and more preferably is in the range of about 500 to 10,000. The average molecular weight of the graft copolymers of the invention is preferably less than about 50,000. As used herein, the term ~average molecular weight~ refers to the number average molecular weight of the polymer as determined ~ G~ pcrmeation chromatography using a suitable solvent for the polymers, such as water, tetrahydrofuran, or N,N-dimethylformamide, and polyacrylic acid, polystyrene, or polyethylene oxide as a standard.
Case 2938C ~ 77 ~9~
As iS generally the case with cement water reducing admixtures and superplasticizers, the graft copolymers of this invention should be water dispersible or water soluble. Thus, the graft copolymer should be dispersible or soluble in a 100%
water medium or an aqueous medium comprised principally of water, e.g., an aqueous alcohol medium containing a minor percentage of alcohol. The pH of the medium may be adjusted as necessary to obtain or optimize dispersibility or solubility.
Where the polyether backbone is a relatively l~ hydrophobic material, such that it has low water dispersiblility or solubility, an appropriate side chain which imparts the desired solubility or dispersibility is grafted to the polyether. Side chains used for this purpose should accordingly be more hydrophilic than the polyether backbone.
Preferred side chains, from the standpoint of promoting water dispersibility and s~lubility, are those which contain salt-forming groups. The salt-forming groups may be provided by homopolymerizing or copolymerizing ethyler.ically unsaturated , monomers containing an acid group, such as acrylic acid, methacrylic acid, or 2-sulfoethylmethacrylate, to form the side chain. Alternatively, monomers may be used which contain precursors which can be reacted after graft polymerization to provide a salt-forming group, e.g., maleic anhydride may be incorporated into the side chain and subsequently hydrolyzed to the acid form. In general, the acid group is converted after grafting to its salt form by neutralization with a base. The salt-forming groups may also be provided by monomers containing a quaternary ammonium group or an amine group which can be guaterniz a~tor polymerization Case 2938C
~ ~ 7~ 99~3 The ethylenically unsaturated monomers used in the invention are polymerizable monomers characterized by the presence therein of at least one polymerizable ethylenic unsaturated group of the structure ~C=C~ . Any such monomer which can be grafted onto a polyether to provide a graft copolymer having a greater plasticizing capability than the polyether, and which permits water dispersibility or solubility of the graft copolymer, can be used in this invention. The monomers can be used singly or in combination to produce homopolymer or copolymer side chains. Examples of ethylenically unsaturated monomers which can be used are the a, ~-ethylenically unsaturated acids, e.g., acrylic acid, methacrylic acid, and itaconic acid; the ~ ,~ -ethylenically unsaturated acid esters, e.g., methyl acrylate, methylmethacrylate, ethylacrylate, 2~hydroxy- propylacrylate, 2-hydroxypropylmethacrylate, 2-hydroxyethylmethacrylate, 2-hydroxyethylacrylate, 2-sulfoethylmethacrylate, 3-sulfopropylmethacrylate, bis-(3-sulfopropyl)itaconate, 2-phenoxyethylacrylate, tetra-hydrofurfurylacrylate, cyclohexylmethacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, and caprolactone acrylate monomere such as Tone M-lO0 monomer of Union Carbide Corp.;
the a, ~ -ethylenically unsaturated acid amides, e.g., acrylamide, methacrylamide, diacetone- acrylamide, dimethylaminopropylmethacrylamide, and 2-acrylamido-2-methylpropane sulfonic acid; ethylenically unsaturated acids and acid esters of the formula (I) CH2 = C - (C)n - COOR4 (I) 30 ~ R3 ~ Case 2938C
... , ~.2779g9 wherein Rl, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters such as vinyl acetate; vinyl ethers; vinyl ketones; vinyl aromatic monomers such as styrene and styrene sulfonic acid; N-vinylpyrrolidone;
polymerizable acid anhydrides such as maleic anhydride and itaconic anhydride; aminoalkylacrylate and methacrylates, e.g., dimethylaminoethyl acrylate and diethylaminoethyl methacrylate;
betaines such as N-t3-sulfopropyl)-N-methacrylosyethyl-N,N-dimethylammonium betaine and 1-(3-sulfopropyl)-2-vinyl pyridinium betaine; and cationic guaternary ammonium monomers such as the quaternized aminoalkyl acrylates and methacrylates. The , ~ -ethylenically unsaturated acids are preferred monomers for use in this invention.
It should be understood that, depending on the nature of the monomer, single monomeric units may become grafted onto the polyether backbone. In particular, monomers conforming to the above formula ~I) may graft in this manner. Accordingly, as used herein, the term ~side chain~ and ~side chain polymer~
broadly include and refer to grafted moieties comprised of a 2~ single monomeric unit. Similarly, reference herein to the polymerization of ethylenically unsaturated monomers broadly include8 the grafting of single monomeric units onto the polyether backbone A generally useful amount of monomer or mixture of monomers for preparing the side chain polymers is within the range of about 5% to 50% by weight, based on the combined weight of the monomer(s) and polyether. Normally, it is preferred to use an amount of monomer which, on average for a number of diE~erent cements, provides a high degree of Case 2938C ~7799~
plasticization, balanced by minimization of any undesired effects which might occur in the hydraulic cement composition.
In addition, the amount of monomer may depend on obtaining a desired water dispersibility or solubility, e.g./ it may be necessary to use a greater amount of hydrophilic monomer with a relatively hydrophobic polyether backbone.
Particularly preferred copolymers of this invention are those comprising a hydroxyl terminated polyoxyalkylene backbone, most preferably a hydroxyl terminated oxyethylene/
oxypropylene copolymer, and side chains comprising a homopolymer or copolymer of acrylic acid. The amount of acrylic acid used in preparing the side chains is preferably in the range of about 10% to 35~ by weight, based on the combined weight of the polyether and acrylic acid, with a more preferred range being about 15% to 25%. These graft copolymers have been found to function effectively as superplasticizers at low dosages in the range of 0.05% to 0.4% by weight, based on the weight of cement solids, with relatively small aocompanying increases in set retardation and good compressive strengths being obtained.
It should be recognized that the present invention brings to the art the practice of introducing functional polymeric materials into hydraulic cement compositions as grafted side chains. This practice may permit a more advantageous use of certain types of polymeric materials which, as free, non-grafted polymers, are normally not suitable or of limited utility in such compositions. Polyacrylic acid polymers, for example, are known to be superplasticizers but are of ii~ u u~ility in hydraulic cement compositions whicl case 2938C
~ ~ 7 7 99~
must set relatively quickly because they impart excessive set retardation. In this invention, however, a polyacrylic acid can be used as a grafted side chain, providing graft copolymers which are comparable superplasticizers but impart comparatively less set retardation than free polyacrylic acid polymers, at an equivalent slump. Thus, for example, a polyacrylic acid homopolymer and a graft copolymer composition of the invention containing a graft copolymer having polyacrylic acid side chains may be used in amounts which provide equivalent slumps in hydraulic cement concretes but, in general, the concrete containing the graft copolymer composition will have a substantially lower setting time.
The graft copolymers of this invention are prepared by free radical addition polymerization of an ethylenically unsaturated monomer or a mixture of such monomers in the presence of a polyether. Although the radical form of the monomer may be generated thermally, it is usually preferred to include a free radical initiator in the reaction mixture.
The polymerization may be accomplished by procedures known in the art, e.g., emulsion or suspension polymerization, bulk polymerization, or solution polymerization. Generally, it is preerred to employ bulk polymerization when the monomer is miscible with the polyether. However, if necessary, an organic solvent or diluent which does not participate in the polymerization reaction may be used.
In addition to the graft copolymer which is formed, the reaction product of the free radical polymerization will generally also contain one or more by-product constituent materials, e.g., non-grafted addition homopolymeLs of the Case 2938C
~ ~ 77 99g monomer (or copolymers where a mixture of monomers is used), and polyether degradation products. The reaction product mixture may also contain unreacted polyether. These reaction product mixtures may be used as admixtures of this invention without purification or segregation of the species therein.
Accordingly, reference throughout this application to graft copolymers is intended to refer also to these reaction product mixtures.
It should be understood that it is very difficult to 1n analyze accurately for the extent of grafting and the degree of polymerization in the side chain, as well as the amount of graft copolymer formed in proportion to by-product polymers.
These parameters will vary with the polyether and monomers used and their relative amounts, the amount and type of initiator, the rate of mixing of the reagents, and reaction temperatures and times. As indicated above, a generally useful amount of monomer for forming the side chains is about 5% to 50% by weight, based on the combined weight of monomer and polyether.
About 10% to 35% by weight, similarly based, is a preferred amount. It will be appreciated that the percentage by weight of the side chains in the graft copolymer will be less than the percentage amount of monomer charged to the reactor, since part of the monomer charge is consumed in the formation of by-products, such as non-grafted addition polymers. The above given weight percentages of monomers, for example, are believed to provide graft copolymers containîng, respectively, about 2%
to 40%, and preferably about 5~ to 30%, by weight of grafted side chains. These are approximate amounts, however, as a consequence of the indeterminate partial COli~LSiOI~ uE monomer Case 2938C
~ 7~99 to side chain and the difficulity in analyzing the reaction product.
The addition polymerization reaction generally may be conducted at a temperature in the range of about 100C to 180C. A more preferred range is about 130 to 160C.
The reaction time can vary over a wide range depending on such factors as polymerization method, reagent and initiator concentrations, and reaction temperature. For example, in bulk polymerizations at a reaction temperature of 130C to 160C, a reaction time of two to six hours is generally sufficient to deplete all of the monomer charge. In a preferred method of preparation, bulk polymerization is employed with a reaction temperature of about 130C to 160C, with gradual addition of at least part of the monomer, lS e.g., with continuous monomer addition over a one to two hour period. The reaction mixture is maintained at the reaction temperature for about one hour after all of the monomer is added.
At the end of the reaction period, the reaction mixture is worked up as necessary to provide a desired admixture product. The work up r.ormally involves simply adding water or a desired aqueous medium to the reaction mixture to provide a desired solids concentration, followed by pH
adjustment. If an organic solvent or diluent is used during the polymerization it is normally removed prior to the addition of water or the aqueous medium.
The pH is normally adjusted to provide optimum solubility or dispersibility of the graft copolymer. Where salt forming acid groups are present on the polymer, for Case 2938C
_ ~ 77 ~99 example, the pH is usually brought to a level above the PKa of the acid so as to form ionic species.
Free radical initiators which may be used to promote the polymerization reaction include the conventional peroxy and S azo initiators. Exemplary initiators are di-tert-butyl peroxide, benzoyl peroxide, lauroyl peroxide, oleyl peroxide, tolyl peroxide, di-tert-butyl diperphthalate, tert-butyl peracetate, tert-butyl perbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hesyne-3, tert-butyl 1~ hydroperoxide, cumene hydroperoxide, hydroperoxide, cyclopentane hydroperoxide, diisopropylbenzene hydroperoxide, p-tert-butyl cumene hydroperoxide, 2,5-dimethyl-hexane-2,5 dihydroperoxide, etc., and mi~tures thereof. The initiator, when included, is generally in the range of 0.001 to 5.0 percent and preferably on the order of 0.05 to 2.5 percent by weight of the polyether and side chain forming monomers.
It is usually desirable to degas the reaction mixture for a sufficient period of time to remove oxygen from the reaction zone since oxygen inhibits the polymerization 2~ reaction. The degassing can be conveniently accomplished by blowing nitrogen gas through the reactor prior to the polymerization. It is also usually desirable to conduct the polymerization under a continuous nitrogen blanket.
As mentioned previously, the present invention is directed in part to hydraulic cement compositions containing the graft copolymers described above. These compositions comprise a hydraulic cement and a graft copolymer. The term "hydraulic cementN is used herein in its ordinary and well accepted sense, dnd ti.u~ Le;~LS to any cement which, when made Case 2938C
~ 77~3~9 into a paste with water, sets and hardens as a result of chemical reactions between the water and cement. Portland cement is the most familiar example of a hydraulic cement and is the preferred material for use in the cement compositions of the invention. Other hydraulic cements which may be used include aluminous, oil well, slag, pozzolanic, and silicate cements, as well as gypsum and magnesium oxychloride based materials.
The hydraulic cement composition may be in a dry powder form or mixed with water to form a plastic mix. It is generally preferred to add the graft copolymer to the cement in connection with preparation of an aqueous hydraulic cement mix i.e., with the mix water or as an additive to the already formed mix composition. The graft copolymer may, however, be added at an earlier stage, such as during the grinding of clinker to prepare the cement.
The graft copolymer is preferably added to the cement in the form of an aqueous solution or dispersion. Generally, the amount of graft copolymer added is in the range of about 0.0l~ to 0.6% by weight, based on the weight of dry cement in the composition. A more preferred range is about 0.05% to 0.4~.
The hydraulic cement compositions may include other functional additives such as set accelerators and retarders, fluid loss agents, air entraining and detraining agents, and other hydraulic cement plasticizing materials. These additives may be added separately or admixed with the graft copolymer prior to addition to the cement. The compositions may also include any of the aggregate materials commonly used in the ~Lade, e g., sand and stone to form structural concretes and various lightweight aggregates such as vermiculite and perlite.
case 2s38c ~799~
Cement compositions of the invention comprising an air detraining agent may be of particular interest in certain applications. Various commercially available air detraining or antifoaming agents can be employed, including tri-n-butylphosphate, l-octanol, the General Electric antifoaming agents sold as GE AF-60 and GE AF-72, the antifoaming agents sold as Antifoam H-10, Antifoam B, and DB
100 by Dow Chemical Co., the antifoaming agents sold under the Foamaster tradename by Diamond Shamrock, and the antifoaming agents sold under the Surfynol tradename by Air Products &
Chemicals Corp. The air detraining agent can be added to a solution or dispersion of the graft copolymer prior to being added to the cement composition or it may be added separately.
The amount of air detraining agent which is used is normally in the range of about 0,1% to 10% by weight, based on the weight of the graft copolymer. A more preferred range is about 1% to 5% by weight. A decrease in setting time of the cement composition may be attained through use of the air detraining agent with little or no change in the plasticity imparted by 2~ the graft copolymer.
The following Examples further describe and illustrate the invention, but are not intended to limit the scope thereof.
Unless otherwise indicated, all parts and proportions are by weight.
~ graft copolymer of acrylic acid and an oxyethylene/oxypropylene copolymer was prepared by the foiLowirly procedure.
case 2938C
~ 77 999 A mixture of 20.0 grams of acrylic acid and l.o gram of tert-butyl perbenzoate was added over a one hour period to 80.0 grams of a hydroxyl terminated oxyethylene/ oxypropylene copolymer sold under the tradename Pluracol-W5100N by BASF
Wyandotte Corporation ~average molecular weight of about 4600) at 145C under nitrogen. After the addition was completed the reaction mixture was maintained at 145C for an additional hour. The reaction mixture was then added to a mixture of 130 qrams of water and 9 grams of sodium hydroxide resulting in a homogeneous solution. The solids concentration in ~he solution was measured to be about 42~ and the pH was about 9Ø
A graft copolymer solution was prepared by the procedure of Example 1 using 75.0 grams of Pluracol W5100N, 25.0 grams of acrylic acid, and 2.0 grams of tert-butyl perbenzoate.
A graft copolymer solution was prepared by the procedure of Example 1 using, as the polyether bac~bone, a hydroxyl terminated oxyethylene/oxypropylene copolymer sold by A BASF Wyandotte Corp. under the tradoname Pluracol W170, having an average molecular weight of about 800. Thus, 80.0 grams of Pluracol W170, 20.0 grams of acrylic acid and 1.0 gram of tert-butyl perbenozate were reacted according to the procedure of Example 1 and the reaction pLOdUC~ rleutralized and diluted as in that Example to produce a solution with a measured solids content of about 42%.
Case 2938C ~7999 A graft copolymer solution was prepared b~ the procedure of Example 1 using, as the polyether backbone, a .. hydroxyl terminated polyoxyethylene sold by Union Carbide Corp.
~A ~ fra~6~
lY~ under the ~r~dcnamc Carbowax 6000. Thus, 150.0 grams of Carbowax 6000, 50.0 grams of acrylic acid, and 3.0 grams of tert-butyl perbenzoate were reacted as described in Example l and the reaction product neutralized and diluted as in that Example to produce a solution with a measured solids content of about 42%.
The graft copolymer solutions prepared in Examples l through 4 were added to concretes prepared using a Type I
Portland cement, sand aggregate, and a water to cement ratio of 0.49. The concretes were mixed for about one minute prior to addition of the copolymer solutions. A sufficient amount of solution was added to provide a graft copolymer concentration of 0.1%, based on the weight of Portland cement in the concretes. (In this and the following Examples 7, 8, and 9, 2~ the amount of graft copolymer added to the concrete is expressed as a percentage of the Portland cement in the composition. This percentage was calculated assuming that lO0 of the solution solids was graft copolymer.~
A reference concrete was prepared in an identical manner, except that the addition Ol grd~t copolyrner solution case 2938c ~7999 was omitted. The slumps of the concretes were measured in accordance with ASTM C143 at about 11 minutes into the mix cycle (10 minutes after addition of the graft copolymer). The initial setting times of the concretes were also measured, in accordance with ASTM C403. The measured results are presented in Table 1, wherein the concretes are designated numerically in correspondence with the graft copolymer solution added from the above Examples.
l~ Concrete Slump ~in.~Initial Settina Time(hr:min~
Reference 3.25 3:40 1 6.75 5:02 2 7.50 5:14 3 6.00 5:11 4 6.25 4 57 A graft copolymer solution was prepared by the procedure of Example 1 using, as the polyether backbone, a hydroxyl terminated polyoxypropylene sold by BASF Wyandotte 2~ Corp. under the tradename Pluracol P 4010, having an average molecular weight of about 4000. Thus, 170.0 grams of Pluracol P 4010, 30.0 grams of acrylic acid, and 1.0 gram of tert-butyl perbenzoate were reacted according to the procedure of Example 1 to prepare a solution with a measured solids content of about 42%.
The graft copolymer solution of Example 6 was added to a concrete prepared using the Type I Portland cement of Example 5, sand aggregate, and a water to cement ratio of 0.49. A
Case 2938C
~,77~
sufficient amount of the solution was added to provide a graft copolymer concentration 0.10%. The time of addition was as in Example 5 and slump and setting time measurements were then made, also as in Example 5, and compared with a reference concrete containing no graft copolymer solution. The slump and setting time of the reference concrete were 3.5 inches and 4:11 while the concrete containing the graft copolymer solution had a measured slump of 6.1 inches and a setting time of 4:49.
To 81 grams of a 42% solids solution of a graft copolymer of acrylic acid and Pluracol W5100N, prepared . according to the procedure of Esample 1, was added 0.35 gram of A tri-n-butyl phosphate (TN~P). Similarly, 0.35 gram of Surfonyl 440 air entraining agent of Air Products & Chemicals Corp. was added to 81 grams of the graft copolymer solution. The resultant solutions were added to concretes prepared using a Type I Portland cement, sand aggregate, and a water to cement ratio of 0.81. The cement factor was 400 lbs./yd. The amount of solution added provided a concentration of graft copolymer 2~ of 0.2%. The solutions were added, and slump and setting times measured, as in Example 5. The compressive strengths were also measured, in accordance with the procedure of ASTM C192. For comparison, two concretes were prepared similarly except that in one concrete the graft copolymer solution alone was added and in the second concrete neither the graft copolymer solution nor an air detraining agent was added. The measured results ~ a ~ ~a~ -18-Case 2938c ~ 799~
are presented in Table 2.
Initial Setting Slump Time Concrete Admixture ~in.) % Air (hr:min) Compressive Strenqth(PSI) Graft Ai r Copolymer Detraining Conc. Aqent 1 day 7 day 28 day - - 2.5 2.5 4:34719 1610 3033 0.2 - 7.50 6.2 6:10643 1752 2~32 0.2 TNBP 7.25 3.8 5:34675 1887 2827 0.2 Suronyl 7.00 3.9 5:30705 1765 2627 The results presented in Table 2 illustrate that air detraining agents can be used to reduce setting time and increase compressive strength without significantly altering the slump increase caused by the graft copolymer.
EXAMP~E 9 To evaluate the water reducing capability of the graft copolymer solution of Example 1 and the effect of water reduction on compressive strength, the solution was added in different amounts to batches of a concrete prepared using a Type I Portland cement and a cement factor of 611 lbs./yd. The water to cement ratio (W/C) was adjusted in each case to provide approximately equivalent slumps which, in turn, were about e~ual to that of a control sample which was prepared without addition of the graft copolymeL ~iU~ dlld W/C of Case 2938C
~ 999 0.50. The control thus provided the basis for determining the degree of water reduction and strength improvement. The measured results are presented in Table 3.
Table 3 Graft Initial Copolymer Slump Setting 28 Day Compressive ~ncentration ~ (in.~ Time(hr:min~ Strenath (psi~
Control 0~50 2.63:59 6358 0.125 0,47 3.24:1S 6764 0.20 0.45 3.04:19 7551 0.30 0.42 2.64:41 7811 0.50 0.40 2.94:58 8301 The results illustrate the substantial water reducing capability of the inventive admixture (up to 20% at the higher dosages) with substantial accompanying increases in compressive strength. Relatively minimal setting time increases were also observed.
Claims (40)
1. A composition comprising a hydraulic cement and a graft copolymer plasticizer for said cement, said graft copolymer comprising a polyether backbone polymer and side chain polymers prepared by polymerization of an ethylenically unsaturated monomer.
2. A composition of claim 1 comprising about 0.01% to 0.6% by weight of said graft copolymer, based on the weight of said hydraulic cement.
3. A composition of claim 1 comprising about 0.05% to 0.4% by weight of said graft copolymer, based on the weight of said hydraulic cement.
4. A composition of claim 1 wherein said backbone polymer comprises a polyoxyalkylene.
5. A composition of claim 4 wherein said polyosyalkylene is a polyoxyethylene, polyoxypropylene, or an oxyethylene/oxypropylene copolymer.
6. A composition of claim 4 wherein said polyoxyalkylene comprises terminal hydroxyl groups.
7. A composition of claim 1 wherein said backbone polymer has an average molecular weight of about 200 to 30,000.
8. A composition of claim 1 wherein said graft copolymer contains about 2% to 40% by weight of said side chain polymers.
9. A composition of claim 7 wherein said graft copolymer contains about 2% to 40% by weight of said side chain polymers.
10. A composition of claim 1 wherein said graft copolymer has an average molecular weight of less than about 50,000.
Case 2938C
Case 2938C
11. A composition of claim 1 wherein said graft copolymer contains about 5% to 30% by weight of said side chain polymers.
12. A composition of claim 1 wherein said monomer is selected from the group consisting of .alpha. , .beta.-ethylenically unsaturated acids, .alpha. , .beta.-ethylenically unsaturated acid esters;.alpha. , .beta.-ethylenically unsaturated acid amides;
ethylenically unsaturated acids and acid esters of the formula wherein R1, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters; vinyl ethers;
vinyl ketones; vinyl aromatic monomers; N-vinylpyrrolidone;
polymerizable acid anhydrides; aminoalkyl acrylates and methacrylates; ethylenically unsaturated betaines; and cationic quaternary ammonium monomers.
ethylenically unsaturated acids and acid esters of the formula wherein R1, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters; vinyl ethers;
vinyl ketones; vinyl aromatic monomers; N-vinylpyrrolidone;
polymerizable acid anhydrides; aminoalkyl acrylates and methacrylates; ethylenically unsaturated betaines; and cationic quaternary ammonium monomers.
13. A composition of claim 1 wherein said monomer is an .alpha.,.beta.-ethylenically unsaturated acid.
14. A composition of claim 1 wherein said monomer is acrylic acid.
15. A composition of claim 14 wherein said backbone polymer is a hydroxyl terminated polyosyalkylene .
16. A composition of claim 15 wherein said backbone polymer comprises an oxyethylene/oxypropylene copolymer.
17. A composition of claim 15 wherein said graft copolymer contains about 5% to 30% by weight of said side chain polymers.
Case 2938C
Case 2938C
18. A composition of claim 1 further comprising an air detraining agent.
19. A composition of claim 18 comprising about 0.1%
to 10% of said air detraining agent, based on the weight of said graft copolymer.
to 10% of said air detraining agent, based on the weight of said graft copolymer.
20. A composition of claim 1 wherein said hydraulic cement is Portland cement.
21. A composition comprising a hydraulic cement and a polymeric reaction product which is a plasticizer for said cement, said reaction product being formed by free radical polymerization of an ethylenically unsaturated monomer in the presence of a polyether.
22. A composition of claim 21 comprising about 0.01%
to 0.6% by weight of said reaction product, based on the weight of said hydraulic cement.
to 0.6% by weight of said reaction product, based on the weight of said hydraulic cement.
23. A composition of claim 21 comprising about 0.05%
to 0.4% by weight of said reaction product, based on the weight of said hydraulic cement.
to 0.4% by weight of said reaction product, based on the weight of said hydraulic cement.
24. A composition of claim 21 wherein said polyether comprises a polyoxyalkylene.
25. A composition of claim 24 wherein said polyoxyalkylene is a polyosyethylene, polyoxypropylene, or an oxyethylene/oxypropylene copolymer.
26. A composition of claim 24 wherein said polyoxyalkylene comprises terminal hydroxyl groups.
27. A composition of claim 21 wherein said polyether has an average molecular weight of about 200 to 30,000.
28. A composition of claim 21 wherein the amount of said monomer is about 5% to 50% of the combined weight of said monomer and said polyether.
Case 2938C
Case 2938C
29. A composition of claim 21 wherein the amount of said monomer is about 10% to 35% of the combined weight of said monomer and said polyether.
30. A composition of claim 21 wherein said reaction product has an average molecular weight of less than about 50,000.
31. A composition of claim 21 wherein said monomer is selected from the group consisting of .alpha.,.beta.-ethylenically unsaturated acids;.alpha.,.beta.-ethylenically unsaturated acid esters; .alpha.,.beta.-ethylenically unsaturated acid amides;
ethylenically unsaturated acids and acid esters of the formula wherein R1, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters; vinyl ethers;
vinyl ketones; vinyl aromatic monomers; N-vinylpyrrolidone;
polymerizable acid anhydrides; aminoalkyl acrylates and methacrylates; ethylenically unsaturated betaines; and cationic quaternary ammonium monomers.
ethylenically unsaturated acids and acid esters of the formula wherein R1, R2, R3, and R4 are each independently hydrogen or alkyl and n is 1 to 20; vinyl esters; vinyl ethers;
vinyl ketones; vinyl aromatic monomers; N-vinylpyrrolidone;
polymerizable acid anhydrides; aminoalkyl acrylates and methacrylates; ethylenically unsaturated betaines; and cationic quaternary ammonium monomers.
32. A composition of claim 21 wherein said monomer is an .alpha.,.beta.-ethylenically unsaturated acid.
33. A composition of claim 21 wherein said monomer is acrylic acid.
34. A composition of claim 31 wherein said polyether is a hydroxyl terminated polyoxyalkylene.
35. A composition of claim 33 wherein said polyether comprises an oxyethylene/oxypropylene copolymer.
36. A composition of claim 21 further comprising an air detraining agent.
Case 2938C
Case 2938C
37. A composition of claim 21 wherein said hydraulic cement is Portland cement.
38. A composition of claim 21 wherein said polymerization is conducted in the presence of a free radical initiator.
39. A composition of claim 38 wherein said polymerization is conducted at a reaction temperature of 100°C. to 180°C.
40. A composition of claim 39 wherein said polymerization is a bulk polymerization conducted at a reaction temperature of 130°C. to 160°C.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/939,647 US4814014A (en) | 1986-12-09 | 1986-12-09 | Hydraulic cement additives and hydraulic cement compositions containing same |
| US939,647 | 1986-12-09 | ||
| US07/121,898 US4960465A (en) | 1986-12-09 | 1987-11-23 | Hydraulic cement additives and hydraulic cement compositions containing same |
| US121,898 | 1987-11-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1277999C true CA1277999C (en) | 1990-12-18 |
Family
ID=26819937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553741A Expired - Lifetime CA1277999C (en) | 1986-12-09 | 1987-12-08 | Hydraulic cement additives and hydraulic cement compositions containing same |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4960465A (en) |
| EP (1) | EP0271435B1 (en) |
| CA (1) | CA1277999C (en) |
| DE (1) | DE3789364T2 (en) |
| DK (1) | DK643687A (en) |
| ES (1) | ES2050120T3 (en) |
| NO (1) | NO875123L (en) |
Families Citing this family (65)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02271953A (en) * | 1989-04-13 | 1990-11-06 | Mitsui Cyanamid Co | Mortar-concrete composition |
| US4948429A (en) * | 1989-06-14 | 1990-08-14 | W. R. Grace & Co.-Conn. | Method of controlling air entrainment in concrete compositions |
| US5028271A (en) * | 1989-07-05 | 1991-07-02 | Nalco Chemical Company | Vinyl grafted lignite fluid loss additives |
| US4946506A (en) * | 1989-09-07 | 1990-08-07 | W.R. Grace & Co.-Conn. | Corrosion inhibiting hydraulic cement additives and compositions containing same |
| US5628822A (en) * | 1991-04-02 | 1997-05-13 | Synthetic Industries, Inc. | Graded fiber design and concrete reinforced therewith |
| US5456752A (en) * | 1991-04-02 | 1995-10-10 | Synthetic Industries | Graded fiber design and concrete reinforced therewith |
| JP2507280B2 (en) * | 1991-12-21 | 1996-06-12 | 竹本油脂株式会社 | Dispersant for cement |
| DE69310753T2 (en) * | 1992-09-01 | 1997-08-28 | Grace W R & Co | ADDITIVES FOR HYDRAULIC CEMENT TO REDUCE UNWANTED CAVITIES AND METHOD FOR USE THEREOF |
| DE4338867A1 (en) * | 1992-12-08 | 1994-06-09 | Sueddeutsche Kalkstickstoff | Water-soluble graft copolymers, used as dispersants for concrete etc. |
| US5739212A (en) * | 1992-12-08 | 1998-04-14 | Skw Trostberg Aktiengesellschaft | Water-soluble graft polymers |
| CH689118A5 (en) * | 1993-06-11 | 1998-10-15 | Nippon Catalytic Chem Ind | Additional means of controlling the flow behavior of cementitious compositions. |
| US5332435A (en) * | 1993-11-12 | 1994-07-26 | Westvaco Corporation | High bond strength cement additives |
| GB9407246D0 (en) * | 1994-04-13 | 1994-06-08 | Sandoz Ltd | Improvements in or relating to organic compounds |
| US5660626A (en) * | 1995-01-31 | 1997-08-26 | Ohta; Akira | Cement dispersing agent |
| US5703174A (en) * | 1995-06-21 | 1997-12-30 | W. R. Grace & Co.-Conn. | Air controlling superplasticizers |
| US5556460A (en) * | 1995-09-18 | 1996-09-17 | W.R. Grace & Co.-Conn. | Drying shrinkage cement admixture |
| CN1096436C (en) * | 1996-03-26 | 2002-12-18 | 阿科化学技术公司 | Cement additives |
| FR2749844B1 (en) * | 1996-06-18 | 1998-10-30 | Schlumberger Cie Dowell | CEMENTING COMPOSITIONS AND APPLICATION THEREOF FOR CEMENTING OIL WELLS OR THE LIKE |
| US5679150A (en) * | 1996-08-16 | 1997-10-21 | Kerkar; Awdhoot Vasant | Drying shrinkage cement admixture |
| CA2277960C (en) * | 1997-01-21 | 2003-09-16 | W.R. Grace & Co.-Conn. | Emulsified comb polymer and defoaming agent composition and method of making same |
| NZ502141A (en) * | 1997-06-25 | 2001-12-21 | W | Admixture and method for optimizing addition of EO/PO superplasticizer to concrete containing smectite clay-containing aggregates |
| US5985989A (en) * | 1997-07-09 | 1999-11-16 | Arco Chemical Technology, Lp | Method of making a water reducing additive for cement |
| FR2776285B1 (en) * | 1998-03-19 | 2000-06-09 | Chryso | WATER-SOLUBLE OR WATER-DISPERSABLE DISPERSANT FOR CEMENTITIOUS COMPOSITIONS AND AQUEOUS SUSPENSIONS OF MINERAL PARTICLES, AND ADMIXTURES CONTAINING SUCH A DISPERSANT |
| US6258161B1 (en) | 1998-11-04 | 2001-07-10 | W. R. Grace & Co.-Conn. | Masonry blocks and masonry concrete admixture for improved freeze-thaw durability |
| US6302955B1 (en) | 1998-11-04 | 2001-10-16 | W. R. Grace & Co.-Conn. | Composition for improving freeze/thaw durability of masonry containing fatty acid-based efflorescence control agents |
| US6861459B2 (en) * | 1999-07-09 | 2005-03-01 | Construction Research & Technology Gmbh | Oligomeric dispersant |
| US6133347A (en) | 1999-07-09 | 2000-10-17 | Mbt Holding Ag | Oligomeric dispersant |
| US6908955B2 (en) | 1999-07-09 | 2005-06-21 | Construction Research & Technology Gmbh | Oligomeric dispersant |
| AU2004205111B2 (en) * | 1999-07-09 | 2007-05-24 | Construction Research & Technology Gmbh | Oligomeric Dispersant |
| US6447696B1 (en) * | 1999-07-30 | 2002-09-10 | Nippon Shokubai Co., Ltd. | Grafted polymer and its production process and use |
| US6528593B1 (en) * | 1999-09-10 | 2003-03-04 | The Dow Chemical Company | Preparing copolymers of carboxylic acid, aromatic vinyl compound and hydrophobic polyalkylene oxide |
| AU2221701A (en) * | 1999-12-21 | 2001-07-03 | Toagosei Co., Ltd. | Polymeric flocculant and method of sludge dehydration |
| SG98009A1 (en) | 1999-12-28 | 2003-08-20 | Nippon Catalytic Chem Ind | Anti-shrinkage agent for hydraulic material |
| US6441054B1 (en) * | 2000-03-02 | 2002-08-27 | W.R. Grace & Co.-Conn | Air management in cementitious mixtures having plasticizer and a clay-activity modifying agent |
| EP1193230B1 (en) | 2000-09-29 | 2005-04-20 | Sofitech N.V. | A cementing composition including a dispersant agent for cementing operation in oil wells |
| FR2815627B1 (en) | 2000-10-25 | 2003-09-05 | Coatex Sas | PROCESS FOR IMPROVING MECHANICAL RESISTANCE IN PARTICULAR "TO THE YOUNG AGES" OF CEMENT MATRICES, CEMENT MATRICES THUS OBTAINED AND THEIR USES |
| FR2815629B1 (en) | 2000-10-25 | 2003-09-05 | Coatex Sas | PROCESS FOR IMPROVING MECHANICAL RESISTANCE IN PARTICULAR "TO THE YOUNG AGES" OF CEMENT MATRICES, CEMENT MATRICES OBTAINED AND THEIR USES |
| US7338990B2 (en) * | 2002-03-27 | 2008-03-04 | United States Gypsum Company | High molecular weight additives for calcined gypsum and cementitious compositions |
| CA2478323C (en) * | 2002-03-27 | 2011-01-04 | United States Gypsum Company | High strength flooring compositions |
| US20030191214A1 (en) * | 2002-04-03 | 2003-10-09 | Mari Masanaga | Admixture composition for hydraulic material |
| US20040226620A1 (en) * | 2002-09-26 | 2004-11-18 | Daniel Therriault | Microcapillary networks |
| US7053125B2 (en) * | 2002-11-14 | 2006-05-30 | The Board Of Trustees Of The University Of Illinois | Controlled dispersion of colloidal suspension by comb polymers |
| JP3727304B2 (en) * | 2002-12-16 | 2005-12-14 | 竹本油脂株式会社 | Gypsum slurry composition |
| US7141617B2 (en) * | 2003-06-17 | 2006-11-28 | The Board Of Trustees Of The University Of Illinois | Directed assembly of three-dimensional structures with micron-scale features |
| US6858660B1 (en) * | 2003-07-31 | 2005-02-22 | Motorola, Inc. | Method and chemistry for automatic self-joining of failures in polymers |
| US7875114B2 (en) * | 2005-06-14 | 2011-01-25 | United States Gypsum Company | Foamed slurry and building panel made therefrom |
| US7544242B2 (en) | 2005-06-14 | 2009-06-09 | United States Gypsum Company | Effective use of dispersants in wallboard containing foam |
| US7504165B2 (en) * | 2005-06-14 | 2009-03-17 | United States Gypsum Company | High strength flooring compositions |
| US20060278128A1 (en) * | 2005-06-14 | 2006-12-14 | United States Gypsum Company | Effective use of dispersants in wallboard containing foam |
| US20060280898A1 (en) * | 2005-06-14 | 2006-12-14 | United States Gypsum Company | Modifiers for gypsum slurries and method of using them |
| US20060280899A1 (en) * | 2005-06-14 | 2006-12-14 | United States Gypsum Company | Method of making a gypsum slurry with modifiers and dispersants |
| US20060278127A1 (en) * | 2005-06-14 | 2006-12-14 | United States Gypsum Company | Gypsum products utilizing a two-repeating unit dispersant and a method for making them |
| US8088218B2 (en) * | 2005-06-14 | 2012-01-03 | United States Gypsum Company | Foamed slurry and building panel made therefrom |
| PL1896374T3 (en) * | 2005-06-14 | 2019-04-30 | United States Gypsum Co | Gypsum slurry utilizing a two-repeating unit dispersant |
| US7572328B2 (en) * | 2005-06-14 | 2009-08-11 | United States Gypsum Company | Fast drying gypsum products |
| US7956102B2 (en) * | 2007-04-09 | 2011-06-07 | The Board Of Trustees Of The University Of Illinois | Sol-gel inks |
| DE102007024964A1 (en) * | 2007-05-30 | 2008-12-04 | Wacker Polymer Systems Gmbh & Co. Kg | Production of solids based on hydraulically setting coating agents |
| US7922939B2 (en) | 2008-10-03 | 2011-04-12 | The Board Of Trustees Of The University Of Illinois | Metal nanoparticle inks |
| US8187500B2 (en) * | 2008-10-17 | 2012-05-29 | The Board Of Trustees Of The University Of Illinois | Biphasic inks |
| US8869895B2 (en) * | 2009-12-08 | 2014-10-28 | Halliburton Energy Services, Inc. | Biodegradable set retarder for a cement composition |
| WO2011139466A1 (en) | 2010-04-28 | 2011-11-10 | W.R. Grace & Co.-Conn. | Waterproofing membrane |
| JP5628087B2 (en) | 2010-05-17 | 2014-11-19 | ダウ グローバル テクノロジーズ エルエルシー | Redispersible powder composition for dry mortar formulations |
| US8815783B2 (en) * | 2011-12-20 | 2014-08-26 | Halliburton Energy Services, Inc. | High molecular weight low polydispersity polymers |
| EP2949716B1 (en) * | 2013-01-28 | 2020-04-29 | Nippon Soda Co., Ltd. | Coating agent |
| CN114685707A (en) * | 2020-12-30 | 2022-07-01 | 南京博特新材料有限公司 | Preparation method of high-regularity polycarboxylic acid superplasticizer |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1264052A (en) * | 1960-05-06 | 1961-06-19 | Rohm & Haas | Hydraulic cement composition containing a particulate salt of acrylic copolymer |
| BE638157A (en) * | 1961-11-13 | 1900-01-01 | ||
| GB1065053A (en) * | 1962-10-19 | 1967-04-12 | Cement Marketing Company Ltd | Inorganic polymer structures |
| USRE28780E (en) * | 1970-10-06 | 1976-04-20 | Wacker-Chemie Gmbh | Process for the preparation of free-flowing, lump-free redispersible, synthetic resin powders |
| US3867159A (en) * | 1970-10-22 | 1975-02-18 | Stanley Works | Foamed concrete structures |
| US3862265A (en) * | 1971-04-09 | 1975-01-21 | Exxon Research Engineering Co | Polymers with improved properties and process therefor |
| US3937633A (en) * | 1972-11-06 | 1976-02-10 | Hercules, Incorporated | Use of radiation-induced polymers in cement slurries |
| AU514678B2 (en) * | 1976-11-24 | 1981-02-19 | W.R. Grace & Co. | Hydraulic cement composition |
| US4171238A (en) * | 1976-12-23 | 1979-10-16 | Johns-Manville Corporation | Method of making reinforced plastic composite structure |
| ZA782268B (en) * | 1977-04-27 | 1979-04-25 | Ici Ltd | Cementitious compositions |
| EP0006279B1 (en) * | 1978-02-22 | 1982-01-27 | Imperial Chemical Industries Plc | Cementitious composition, a method to prepare it and shaped article derived therefrom |
| DE2900110A1 (en) * | 1979-01-03 | 1980-07-10 | Wolff Walsrode Ag | SOLUBLE MACROMOLECULAR SUBSTANCES WITH HIGH DISPERSION, SUSPENDING AND LIQUID RETENTION RESISTANCE, METHOD FOR THEIR PRODUCTION AND USE |
| DE3046585A1 (en) * | 1980-12-11 | 1982-07-22 | Henkel KGaA, 4000 Düsseldorf | MORTAR BLENDS AND THEIR USE |
| DE3176693D1 (en) * | 1980-12-22 | 1988-05-05 | Ici Plc | Cementitious composition and cementitious product of high flexural strength |
| JPS59146961A (en) * | 1983-02-04 | 1984-08-23 | 鹿島建設株式会社 | Slump loss preventing agent for hydraulic cement blend |
| US4676317A (en) * | 1986-05-13 | 1987-06-30 | Halliburton Company | Method of reducing fluid loss in cement compositions which may contain substantial salt concentrations |
| US4814014A (en) * | 1986-12-09 | 1989-03-21 | W. R. Grace & Co. | Hydraulic cement additives and hydraulic cement compositions containing same |
-
1987
- 1987-11-23 US US07/121,898 patent/US4960465A/en not_active Expired - Lifetime
- 1987-12-08 DE DE3789364T patent/DE3789364T2/en not_active Expired - Fee Related
- 1987-12-08 ES ES87730163T patent/ES2050120T3/en not_active Expired - Lifetime
- 1987-12-08 NO NO875123A patent/NO875123L/en unknown
- 1987-12-08 CA CA000553741A patent/CA1277999C/en not_active Expired - Lifetime
- 1987-12-08 DK DK643687A patent/DK643687A/en not_active Application Discontinuation
- 1987-12-08 EP EP87730163A patent/EP0271435B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0271435A3 (en) | 1989-06-28 |
| ES2050120T3 (en) | 1994-05-16 |
| DK643687A (en) | 1988-06-10 |
| NO875123L (en) | 1988-06-10 |
| US4960465A (en) | 1990-10-02 |
| DE3789364T2 (en) | 1994-06-23 |
| DK643687D0 (en) | 1987-12-08 |
| NO875123D0 (en) | 1987-12-08 |
| DE3789364D1 (en) | 1994-04-21 |
| EP0271435B1 (en) | 1994-03-16 |
| EP0271435A2 (en) | 1988-06-15 |
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| MKLA | Lapsed |