JP4976028B2 - Cement admixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cement admixture comprising an emulsion composition having excellent preservation stability and blended in cement to have excellent effect in cement strength and adhesiveness. <P>SOLUTION: The cement admixture comprises the emulsion composition containing a synthetic resin water based emulsion and a water soluble cationic polymer having molecular weight of 3,000-500,000. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a cement admixture that is excellent in stability of an emulsion composition and has stable cement adhesive strength and fluidity of a mixed cement regardless of the storage period.

  Conventionally, it is known that an aqueous emulsion using polyvinyl alcohol (hereinafter referred to as PVA) as a protective colloid agent is used for mixing with cement. Although the mechanical stability and freezing stability of the emulsion are improved by using PVA as a protective colloid agent, the polymerization stability is insufficient, and in particular, the resin content in the emulsion is high enough to exceed 50% by weight. It was not possible to polymerize at the concentration.

  Therefore, when PVA is used as a protective colloid agent for an acrylic aqueous emulsion, the resin content in the emulsion must be 50% by weight or less, which is problematic in terms of productivity. Moreover, the stability of the obtained emulsion was also insufficient, and there was a problem that the viscosity increased with time.

  In addition, when an aqueous emulsion using PVA as a protective colloid agent is mixed into cement, there is a problem that the fluidity of the cement deteriorates with time and the workability decreases.

  Therefore, when PVA is used as a protective colloid agent for an aqueous emulsion, the aqueous emulsion can be polymerized even if the resin content in the emulsion is 50% by weight or more, and the workability does not deteriorate even when mixed with cement. Development was desired.

As such a countermeasure, it has been proposed to use acetoacetyl (CH ₃ COCH ₂ CO—) group-containing PVA as an emulsifying dispersant, which is described in many patent documents.

  For example, Patent Document 1 contains an active hydrogen group such as an acetoacetate group, a mercapto group, a diacetone acrylamide group, a block character [η] larger than 0.6, and a saponification degree of 95.0 mol%. An aqueous emulsion in which higher and lower blocking PVA is attached to a polymer is disclosed, and it is stated that the resulting aqueous emulsion has good mechanical stability, freezing stability, and high-temperature storage stability. . However, although an aqueous emulsion having good mechanical stability, freezing stability, and high-temperature storage stability has been obtained, the viscosity stability during long-term storage has not yet been satisfactory.

JP 2003-277419 A

  An object of the present invention is to provide a cement admixture that has good storage stability of an emulsion composition, and is excellent in cement strength and adhesiveness by blending with an emulsion, and further, the fluidity of the admixture cement is stable regardless of the storage period. It is to provide.

  Thus, as a result of detailed studies by the present inventors, it has been found that the above object can be achieved by using a polymer having a molecular weight smaller than that of a polymer having a molecular weight of 1,000,000 which has been conventionally added to cement admixtures. Was completed.

That is, the present invention is Ri Do from an emulsion composition containing a synthetic resin aqueous emulsion and water-soluble cationic polymer having a molecular weight of from 3,000 to 500,000, synthetic resin aqueous emulsion comprises an acrylic polymer and a polyvinyl alcohol component, water-soluble cationic polymer Ru polymer der containing diallyl dimethyl ammonium chloride units regarding cement admixture.

  The water-soluble cationic polymer is preferably a copolymer of diallyldimethylammonium chloride and acrylamide.

  The PVA component is preferably at least one PVA selected from the group consisting of unmodified PVA and modified PVA.

  The PVA component is preferably a mixture of acetoacetyl group-modified PVA and anion-modified PVA.

  It is preferable that the cement admixture has a zeta potential of 3.0 to 100 mV.

  The water-soluble cationic polymer is preferably contained in an amount of 0.1 to 50% by weight in terms of solid content with respect to the synthetic resin aqueous emulsion.

The present invention contains a water-soluble cationic polymer having a molecular weight of 3000 to 500,000 containing a diallyldimethylammonium chloride unit, so that the storage stability of the emulsion composition is good, and by adding it to cement, the cement strength and adhesiveness are improved. It is possible to provide a cement admixture having an excellent effect and having a stable fluid property of the admixture cement regardless of the storage period.

The present invention, synthetic resin aqueous Ri Do from the emulsion and the emulsion composition containing a water-soluble cationic polymer having a molecular weight of from 3,000 to 500,000, synthetic resin aqueous emulsion comprises an acrylic polymer and a polyvinyl alcohol component, water-soluble cationic polymer is diallyldimethylammonium Ru polymer der containing ammonium chloride units regarding cement admixture.

  The molecular weight of the water-soluble cationic polymer is 3000 to 500000, more preferably 3000 to 300000, and still more preferably 10000 to 200000. Furthermore, the molecular weight is most preferably 10,000 to 50,000 in consideration of compatibility at the time of addition and cement miscibility. If the molecular weight exceeds the upper limit, the stability of the synthetic resin water-based emulsion composition is lowered, and aggregates are generated, and the viscosity tends to increase excessively. On the other hand, if the molecular weight is less than the lower limit, the adsorption to the emulsion particles is insufficient and the expected cement strength and adhesive strength tend to be insufficient.

  In the present invention, a water-soluble cationic polymer having a molecular weight of 3000 to 500,000 is used. Such a polymer is a polymer having a lower molecular weight than a polymer having a molecular weight of 1,000,000 which is conventionally added to cement admixtures. In the case of a cationic polymer having a molecular weight of 500,000 or more, further 1,000,000 or more that has been used in the past, when mixed, it acts as an aggregating agent between the emulsion particles, causing the particles to aggregate, and easily causing gelation / sedimentation. In the case of these conventional water-soluble cationic polymers, even if it is a nonionic system protected with water-soluble PVA as in the present invention, the aggregating action by the high-molecular weight cationic resin is greatly affected. In the present invention, a water-soluble cationic polymer having a molecular weight in a specific range can be stably mixed with the synthetic resin aqueous emulsion of the present invention, and the purpose of improving the adhesive force can be achieved.

As the water-soluble cationic polymer, a water-soluble cationic polymer containing a diallyldimethylammonium chloride unit is used because it is easily available, is excellent in safety to the environment and the human body, and is not too strong in cation strength.

  In particular,

It is a polymer which has a repeating unit shown by these . In other words, Ri polymer der containing diallyl dimethyl ammonium chloride units, good Mashiku the Ru copolymer der of diallyl dimethyl ammonium chloride and acrylamide.

  The addition amount of the water-soluble cationic polymer is preferably 0.1 to 50% by weight and more preferably 0.1 to 10% by weight in terms of solid content with respect to the synthetic resin aqueous emulsion. When the addition amount is less than the lower limit value, the added effect tends not to be recognized, and when the addition amount exceeds the upper limit value, the synthetic resin aqueous emulsion tends to aggregate.

The synthetic resin aqueous emulsion, alkali resistance, in terms of durability, those containing A acrylic polymer and PVA components are employed.

  As the acrylic polymer, an acrylic copolymer obtained by copolymerizing (meth) acrylic acid ester as a main component and other copolymerizable monomers as required is used. An acetoacetyl group-containing acrylic copolymer can also be used.

  Here, the main component means that 50% by weight or more of (meth) acrylic acid ester is contained in all monomers constituting the acrylic polymer, and more preferably 51% by weight or more.

  (Meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, I-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexylhexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate And aliphatic (meth) acrylic acid alkyl esters such as cyclohexyl (meth) acrylate and aromatic (meth) acrylic acid esters such as benzyl (meth) acrylate.

  Moreover, (meth) acrylic acid; hydroxyl group-containing (meth) acrylic acid ester such as 2-hydroxyethyl (meth) acrylate, functional group-containing (meth) acrylic acid ester such as dimethylaminoethyl (meth) acrylate, etc. Can be used.

  Other copolymerizable monomers include styrene monomers such as styrene and α-methylstyrene; butadiene-1,3, 2-methylbutadiene, 1,3 or 2,3-dimethylbutadiene-1,3, Diene monomers such as 2-chlorobutadiene-1,3; vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, stearin Vinyl ester monomers such as vinyl acid vinyl, vinyl benzoate and vinyl versatate; Olefin monomers such as ethylene, propylene, 1-butene and isobutene; Vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, etc. Of halogenated olefin monomers: methacrylamide, N-methylolacrylamide Acrylamide monomers such as N, N-dimethylacrylamide, acrylamide-2-methylpropanesulfonic acid and diacetone acrylamide; Nitrile monomers such as methacrylonitrile; methyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, vinyl ether of stearyl vinyl ether; allylic monomers such as allyl acetate and allyl chloride can be used. In addition, carboxyl group-containing compounds such as fumaric acid, maleic anhydride, itaconic anhydride, trimetic acid, and esters thereof; ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamido-2-methyl Sulfonic acid group-containing compounds such as propanesulfonic acid; vinylsilane compounds such as vinyltrimethoxysilane; isopropenyl acetate, 3-methacrylamidopropyltrimethylammonium chloride, 3,4-diacetoxybutene, vinylethylene carbonate, etc. can also be used. .

  The PVA component is preferably at least one PVA selected from the group consisting of unmodified PVA and modified PVA.

  Here, the PVA is a saponified product obtained by saponifying a polyvinyl acetate solution with an alkali or an acid, or a derivative thereof. Further, a copolymer of vinyl acetate and a monomer copolymerizable with vinyl acetate is used. A saponified product obtained by saponifying a polymer can be used as long as the object of the present invention is not impaired.

  Saponification is carried out by dissolving a polymer such as polyvinyl acetate in an alcohol or hydrous alcohol and using an alkali catalyst or an acid catalyst. Examples of the alcohol include C1-C6 saturated alcohols such as methanol, ethanol, propanol, and tert-butanol. Among these, methanol is particularly preferably used. The concentration of the polymer in the alcohol is appropriately selected depending on the viscosity of the system, but is usually selected from the range of 10 to 60% by weight.

  Catalysts used for the saponification include sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate, alkali metal hydroxides such as lithium methylate, alkali catalysts such as alcoholate; sulfuric acid, Examples include acid catalysts such as hydrochloric acid, nitric acid, metasulfonic acid, zeolite, and cation exchange resin. About the usage-amount of a saponification catalyst, it selects suitably by saponification methods, the target saponification degree, etc., but when using an alkali catalyst, it is 0.1-30 mmol normally with respect to 1 mol of PVA. It is preferable that the amount be 2 to 17 mmol. The reaction temperature for the saponification reaction is not particularly limited, but is preferably 10 to 60 ° C, more preferably 20 to 50 ° C.

  Preferred conditions to be provided in such PVA include saponification degree, polymerization degree, 1,2-glycol bond amount, and the like, which will be sequentially described below.

  The saponification degree of PVA is preferably 95 to 100 mol%, more preferably 97.0 to 99.8 mol%. When the degree of saponification is less than the lower limit, the polymerization tends to become unstable.

  Although the polymerization degree of PVA is not specifically limited, It is preferable that it is 10-1000, More preferably, it is 20-800, More preferably, it is 20-500. If the degree of polymerization is less than the lower limit, there is a tendency not to have protective colloid properties, and it is difficult to industrially produce PVA less than the lower limit. Moreover, since the viscosity of an emulsion tends to become high too much when exceeding an upper limit, it is not preferable.

  The modified PVA is not particularly limited, and various anion group modifications such as carboxylic acid, sulfonic acid and phosphoric acid, cation group containing quaternary ammonium group, acetoacetyl group, diacetone acrylamide group, mercapto group, silanol group Among them, PVA containing a functional group having an active hydrogen and PVA containing a group having an anion are preferable.

  As the functional group having active hydrogen, for example, an acetoacetyl group, a diacetone acrylamide group, an amino group, a mercapto group, and the like are preferable. Among these, an acetoacetyl group is particularly preferable from the viewpoint of high graft reactivity. Is preferred.

  The amount of modification by the functional group having active hydrogen of PVA is preferably 0.01 to 6.0 mol%, more preferably 0.03 to 4.5 mol%, still more preferably 0.03 to 2. It is 0 mol%, Especially preferably, it is 0.03-1.0 mol%. When the amount of modification is less than the lower limit, the protective colloid properties tend to decrease and cement admixture stability tends to decrease, and when the amount exceeds the upper limit, the polymerization stability of the emulsion tends to decrease.

  In addition, when PVA is PVA modified with an acetoacetyl group, the degree of acetoacetylation is preferably 0.01 to 5 mol%, more preferably 0.03 to 3 mol%, still more preferably. Is 0.03 to 1 mol%. If the degree of acetoacetylation is less than the lower limit, the water resistance and mechanical strength of the emulsion tend to be insufficient, and if the upper limit is exceeded, the polymerization stability of the emulsion tends to decrease.

  As the group having an anion, a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, and the like are preferable. Among these, a strong charge repulsion can be obtained stably regardless of the pH in the emulsion. A sulfonic acid group is preferred.

  The amount of modification of the group having an anion of PVA is preferably 0.01 to 5 mol%, more preferably 1.0 to 4 mol%. If the modification amount is less than the lower limit, the charge repulsion effect tends to be weak and the addition effect tends to be low, and if the amount exceeds the upper limit, the polymerization stability of the emulsion tends to decrease.

  When the anion-modified PVA is a sulfonic acid-modified PVA, the amount of modification with a sulfonic acid group is preferably 0.01 to 5 mol%, more preferably 1.0 to 4 mol%. If the amount of modification is less than the lower limit, the stability of the emulsion due to charge repulsion cannot be improved and the effect of the present invention tends to be insufficient, and if the upper limit is exceeded, the particle size of the emulsion becomes smaller. Again, there is a tendency that the stability of the emulsion cannot be improved and the effects of the present invention cannot be obtained sufficiently.

  As the PVA component, the above PVA may be used alone or as a mixture of two or more thereof. Among these, from the viewpoint of mixing stability, acetoacetyl group-modified PVA and anion-modified PVA, preferably A blend of sulfonic acid-modified PVA is preferred.

  When acetoacetyl group-modified PVA and anion-modified PVA are used in combination, the anion-modified PVA content is preferably 0.1 to 100 parts by weight, more preferably 100 parts by weight of acetoacetyl group-modified PVA. 20 to 70 parts by weight, more preferably 20 to 50 parts by weight. When the content of the anion-modified PVA is less than the lower limit value, the viscosity stabilizing effect tends to be reduced, and the physical property tends to vary widely. When the content exceeds the upper limit value, the graft ratio tends to decrease.

  The synthetic resin aqueous emulsion used in the present invention is obtained by temporarily or continuously adding a monomer component constituting a synthetic resin to a PVA aqueous solution in which the PVA component is dissolved in water in the presence of a polymerization initiator. It is prepared by heating and stirring. A conventionally well-known method can be employ | adopted about various conditions in preparation. In the synthetic resin water-based emulsion obtained by the above-described method, at least a part of the PVA component used for dispersion stabilization is grafted to the polymer, which can suppress emulsion aggregation during cement mixing. This is preferable because a good cement or mortar can be obtained.

  The average particle size of the polymer particles in the synthetic resin aqueous marsion obtained above is preferably 0.01 to 5 μm, more preferably 0.1 to 2 μm, still more preferably 0.1 to 0.5 μm. is there. If the average particle size is less than the lower limit, aggregation tends to occur when mortar is mixed, and if the upper limit is exceeded, film-forming properties tend to decrease and mortar strength tends to decrease. The average particle size of the water-based emulsion is calculated based on the Mie scattering theory using a laser diffraction / scattering particle size distribution measuring apparatus LA-910 manufactured by HORIBA.

  The cement admixture of the present invention is obtained by adding a water-soluble cationic polymer to a synthetic resin water-based emulsion. The addition method may be batch addition or continuous addition. It is not limited. Further, a monomer such as a (meth) acrylic acid ester monomer may be emulsion-polymerized in the presence of the PVA, and a water-soluble cationic polymer may be added after the emulsion polymerization.

  Moreover, as zeta potential of the obtained cement admixture, it is preferable that it is 0.1-100 mV, It is more preferable that it is 1-100 mV, It is further more preferable that it is 3-100 mV. If the zeta potential is less than the lower limit, the cement strength and adhesiveness tend to be inferior, and if the upper limit is exceeded, the stability of the emulsion composition tends to decrease.

  The cement admixture of the present invention is used for admixture of cement and mortar (cement base conditioner, inorganic finishing agent, mortar sealer and primer mortar curing agent), and the storage stability of the emulsion composition is good. Therefore, it is possible to obtain a cement admixture having excellent effects in cement strength and adhesiveness, and having a stable fluid property of the admixture cement regardless of the storage period.

  When adding to cement or mortar, for example, considering the physical properties of the resulting cured product, it is preferable to add 1 to 30 parts by weight, and more preferably 3 to 30 parts by weight with respect to 100 parts by weight of cement or mortar. . Considering an economical aspect, 5 to 15 parts by weight is preferable, and 8 to 12 parts by weight is more preferable.

  As a method of mixing the cement admixture of the present invention comprising an emulsion composition containing a synthetic resin water-based emulsion and a water-soluble cationic polymer into cement or mortar, a method of mixing (compounding) with water in advance, cement or mortar, Although the method of mixing water and an admixture simultaneously is mention | raise | lifted, the method of mixing (mixing) with water beforehand is preferable.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.

  In the examples and comparative examples, “parts” represent “parts by weight”.

  Each emulsion composition (admixture) obtained in the examples and comparative examples was evaluated in the following manner.

<Stability evaluation of emulsion composition>
100 g of an aqueous emulsion was taken in a beaker, 10 g of a water-soluble cationic polymer was added with stirring, and the mixture was stirred for 10 minutes to obtain an emulsion composition. Visual observation confirmed the occurrence of aggregates immediately after addition, thickening, and the state after storage at 23 ° C. for 3 months. The evaluation criteria are as follows.
○ ・ ・ ・ No aggregation or viscosity increase immediately after addition or even over time △ ・ ・ ・ Small amount of aggregate immediately after addition × ・ ・ ・ Most aggregates immediately after addition, increase in several days Sticky

<Mortar mixing fluidity>
A mortar mixing test was conducted according to JIS A6203. 500 g of ordinary Portland cement (available from Taiheiyo Cement Co., Ltd.), 1500 g of Toyoura cinnabar (available from Toyoura Silica Mining Co., Ltd.), 111 g of the emulsion obtained in Examples and Comparative Examples adjusted to a solid content of 45%, and The mortar was prepared by stirring 263 g of the kneaded water for 3 minutes using a Hobart mixer. The flowability of the mortar was measured by measuring the spread diameter of the cement by applying the 12 mm drop impact 15 times after filling the mortar with a flow cone having a bottom diameter of 100 mm placed on the flow table and removing the flow cone. This was evaluated by the following criteria as mortar mixing fluidity (initial flow). Similarly, the flow value after 3 months was also evaluated.
○ ・ ・ ・ 150mm or more △ ・ ・ ・ 130mm or more, less than 150mm × ・ ・ ・ less than 130mm

<Mortar bond strength>
A mortar bond strength test was conducted in accordance with JIS A 6203 and evaluated according to the following criteria. Preparation of specimen: A mortar substrate (70 × 70 × 20 mm / JIS R 5201 compliant) was polished using No. 150 polishing paper defined in JIS R 6252. Each test mortar was filled to 40 × 40 × 10 mm using a mold on the substrate, and molded and cured to prepare a specimen. Curing conditions: After molding, after 48 hours at a temperature of 20 ± 2 ° C and relative humidity of 90% or more, the mold was removed and then cured in water at a temperature of 20 ± 2 ° C for 5 days. Cured for 21 days at a humidity of 60 ± 10%.
◎ ・ ・ ・ Adhesion strength 1.5 N / mm ² or more ○ ・ ・ ・ Adhesion strength 1.0 N / mm ² or more, less than 1.5 N / mm ² △ ・ ・ ・ Adhesion strength 0.8 N / mm ² Above, less than 1.0 N / mm ² × ・ ・ ・ Adhesive strength less than 0.8 N / mm ²

<Zeta potential>
The zeta potential of the emulsion composition was measured using “ZEECOM IP-120B SYSTEM” manufactured by Microtech Nichion Co., Ltd.

Example 1
In a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, water 403 g, acetoacetyl group-modified PVA (A-1) (saponification degree 97.0 mol%, polymerization degree 300, acetoacetylation degree) 18.4 g of allylsulfonic acid-modified PVA (B-1) (saponification degree 99.0 mol%, polymerization degree 300, sulfonic acid group modification amount 3.0 mol%) 4.6 g As a pH adjuster, 1.2 g of sodium acetate and 0.7 g of sodium acid sulfite were charged, and the mixture was heated and stirred (stirring speed was 230 rpm) at 85 ° C. for 1 hour to dissolve PVA. After confirming that the aqueous PVA solution was stable at 83 ° C., 32.5 g of polymerization monomers (methyl methacrylate / n-butyl acrylate / acetoacetic acid monomer = 45/55 / 0.5 (weight ratio)) were charged all at once. After sufficiently stirring for 5 minutes, 5.3 g of a 5% aqueous solution of ammonium persulfate was added all at once to initiate initial polymerization. The initial polymerization is performed for 45 minutes, and then 293 g of the remaining polymerization monomer is added dropwise at 82 to 83 ° C. over 3.5 hours. Further, 10.7 g of 5% ammonium persulfate aqueous solution is divided into 7 times every 30 minutes. The polymerization was carried out. 1.8 g of 5% aqueous solution of ammonium persulfate was added in two portions, followed by late polymerization at 82 ° C. for 90 minutes, followed by cooling and addition of 11.6 g of antifoaming agent Lumiten EL (manufactured by Clariant). An aqueous emulsion of 45% methyl methacrylate / n-butyl acrylate copolymer was obtained. The average particle diameter of the polymer particles was 317 nm.

  5.0 g of diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10,000) as a water-soluble cationic polymer was added to 500 g of the synthetic resin aqueous emulsion thus obtained. The product (average particle size is 362 nm) was obtained and its stability was evaluated. The evaluation results are shown in Table 1.

Example 2
Diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10000) is diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81, manufactured by Nittobo Co., Ltd.). , Except that the molecular weight was changed to 200000), the same procedure as in Example 1 was carried out to obtain an emulsion composition, and its stability was evaluated. The evaluation results are shown in Table 1.

Example 3
A diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10,000) was converted into a diallyldimethylammonium chloride polymer (PAS-M-1, manufactured by Nittobo Co., Ltd., molecular weight 20000). Except for changing to), the same procedure as in Example 1 was performed to obtain an emulsion composition, and its stability was evaluated. The evaluation results are shown in Table 1.

Example 4
Diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10000) is diallyldimethylammonium chloride / maleic acid copolymer (PAS-410, manufactured by Nittobo Co., Ltd.) The emulsion composition (average particle size is 326 nm) was obtained in the same manner as in Example 1 except that the stability was evaluated. The evaluation results are shown in Table 1.

Example 5
Diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10000) is diallyldimethylammonium chloride / epichlorohydrin copolymer (PAS-880, Nittobo Co., Ltd.). The emulsion was obtained in the same manner as in Example 1 except that the molecular weight was changed to 40000, and the stability was evaluated. The evaluation results are shown in Table 1.

Example 6
A diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10000) is diallyldimethylammonium chloride polymer (PAS-H-1L, manufactured by Nittobo Co., Ltd., molecular weight 8500). The emulsion composition (average particle size is 354 nm) was obtained in the same manner as in Example 1 except that it was changed to), and its stability was evaluated. The evaluation results are shown in Table 1.

Comparative Example 1
Diallyldimethylammonium chloride / acrylamide copolymer (PAS-J-81L, manufactured by Nittobo Co., Ltd., molecular weight 10,000) is diallyldimethylammonium chloride polymer (Magnafloc 368, manufactured by Ciba Specialty Chemicals Co., Ltd., molecular weight 1000000). The procedure was the same as in Example 1 except that the emulsion composition was changed to 1. However, a good emulsion composition could not be obtained.

  The cement admixture of the present invention is used for admixture of cement and mortar (cement base conditioner, inorganic finishing agent, mortar sealer and primer mortar curing agent), and the storage stability of the emulsion composition is good. Therefore, it is possible to obtain a cement admixture having excellent effects in cement strength and adhesiveness, and having a stable fluid property of the admixture cement regardless of the storage period.

Claims (6)

Ri Do synthetic resin aqueous emulsion and the emulsion composition containing a water-soluble cationic polymer of molecular weight 3000 to 500,000, synthetic resin aqueous emulsion comprises an acrylic polymer and a polyvinyl alcohol component, water-soluble cationic polymer is a diallyldimethylammonium chloride units cement admixture, wherein the polymer der Rukoto containing. Water-soluble cationic polymer, the cement admixture according to claim 1 Symbol mounting characterized in that it is a copolymer of diallyl dimethyl ammonium chloride and acrylamide. The cement admixture according to claim 1 or 2 , wherein the polyvinyl alcohol component is at least one polyvinyl alcohol selected from the group consisting of unmodified polyvinyl alcohol and modified polyvinyl alcohol. The cement admixture according to any one of claims 1 to 3, wherein the polyvinyl alcohol component is a mixture of acetoacetyl group-modified polyvinyl alcohol and anion-modified polyvinyl alcohol. The cement admixture according to any one of claims 1 to 4 , wherein the cement admixture has a zeta potential of 3 to 100 mV. The cement admixture according to any one of claims 1 to 5 , wherein the water-soluble cationic polymer is contained in an amount of 0.1 to 50 wt% in terms of solid content with respect to the synthetic resin aqueous emulsion.