JPH08120121A - Polymer dispersion for polymer cement mortar composition and polymer cement mortar composition - Google Patents

Abstract

PURPOSE: To obtain a polymer cement mortar composition having improved characteristics such as weather resistance, heat resistance and chemical resistance, excellent execution and adhesiveness, not causing dry out, showing excellent hardening stability. CONSTITUTION: This polymer dispersion for a polymer cement mortar composition comprises a cationic acrylic resin emulsion obtained by copolymerizing at least one of an acrylic acid alkyl ester and a methacrylic acid alkyl ester with an amino group-containing acrylic monomer and a chloroprene latex, has the weight ratio of solid content of the former/the latter of 25/75 to 75/25. This polymer cement mortar composition comprises 100 pts.wt. of cement, 50-500 pts.wt. of an aggregate and 5-25 pts.wt. (solid content) of the polymer dispersion.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer dispersion for a polymer cement mortar composition, and a polymer cement mortar composition containing the polymer dispersion.

[0002]

2. Description of the Related Art Polymer cement mortar, in which cement and resin are used together as a binder to bond aggregates with each other, has better elongation ability than concrete and less cracking due to changes in temperature and humidity. It is used as a mortar for gluing porcelain tiles due to its good adhesiveness. Further, in recent years, due to its good workability, it has been used as an undercoat material for outer walls and floors and as a repair material for concrete structures.

In such a polymer cement mortar,
As the polymer component, an aqueous dispersion containing a resin component such as an acrylic polymer, polyethylene, polyvinyl acetate, or a styrene-butadiene copolymer is mainly used, but these polymer components are dispersed in a mortar. The hardened polymer cement mortar is exposed to external factors such as acid rain, salt damage, cement alkali, water and temperature.
There is a drawback that the strength is likely to deteriorate due to deterioration or change.

Therefore, compared with the above resins, the weather resistance,
Attempts have been made to use chloroprene latex, which has excellent heat resistance, chemical resistance, etc., and is also stable in terms of molecular structure, as a polymer dispersion for admixing cement mortar, but polymer cement mortar using chloroprene latex is a There is a drawback that workability is poor due to poor trowel handling properties during construction, and because the viscosity unique to chloroprene latex makes it impossible to hold the trowel, it sticks to the trowel during surface hardening and causes fine cracks. It is easy and cannot be put to practical use. Furthermore, polymer cement mortar using chloroprene latex,
When directly applied on concrete as an undercoat material for outer walls, floors, etc., there is also a problem that the underlying concrete absorbs moisture to cause dryout, and peeling easily occurs.

[0005]

In view of the problems of the prior art as described above, the inventor of the present invention has good characteristics such as weather resistance, heat resistance, chemical resistance, etc., and has good workability and adhesiveness. The inventors have earnestly conducted research to obtain a polymer cement mortar composition which is excellent in curing stability and does not cause dryout and has good curing stability. As a result, the polymer cement mortar composition in which an aqueous dispersion obtained by mixing a chloroprene latex and a specific cationic acrylic resin emulsion is blended as a polymer dispersion component is easy to apply and has excellent adhesive strength, and the formed film has weather resistance. It has been found that the properties such as heat resistance, heat resistance, and chemical resistance are good, and that dry cracks hardly occur, and the present invention has been completed here.

That is, the present invention provides the following polymer dispersion for polymer cement mortar composition and polymer cement mortar composition.

(I) A cationic acrylic resin emulsion obtained by copolymerizing at least one of an alkyl acrylate and an alkyl methacrylate with an acrylic monomer containing an amino group, and a chloroprene latex. Weight ratio of solid content is 2
Polymer dispersion for polymer cement mortar composition, which is 5/75 to 75/25.

(II) (i) 100 parts by weight of cement, (ii) 50 to 500 parts by weight of aggregate, and (iii) at least one of alkyl acrylate and methacrylic acid alkyl ester and an amino group-containing acrylic monomer. It consists of a cationic acrylic resin emulsion obtained by copolymerization and chloroprene latex, and has a weight ratio of the solid content of the former / the latter of 25.
A polymer cement mortar composition containing 5 to 25 parts by weight (solid content) of a polymer dispersion component of / 75 to 75/25.

In the polymer cement mortar composition of the present invention, as the polymer dispersion component, a cationic acrylic resin obtained by copolymerizing at least one of acrylic acid alkyl ester and methacrylic acid alkyl ester with an amino group-containing acrylic monomer. It is necessary to use an aqueous dispersion obtained by mixing the emulsion and chloroprene latex. By using a combination of such two specific polymer components, without impairing the excellent weather resistance, heat resistance, chemical resistance, etc., which are the characteristics of chloroprene latex,
It is possible to easily form a good film without cracks etc. by improving the inferior workability such as trowel handling property, trowel smoothing property, trowel holding property, which was a drawback when using chloroprene latex, Furthermore, even when it is directly applied to concrete, dry-out does not occur, and it becomes possible to form a film with good adhesiveness.

The chloroprene latex used in the present invention is an aqueous dispersion of a homopolymer of chloroprene or an aqueous dispersion of a copolymer of chloroprene and another copolymerizable monomer. In the chloroprene copolymer, 80% by weight or more of the monomer component is preferably chloroprene. The chloroprene latex used in the present invention can be obtained according to a general emulsion polymerization method. For example, a monomer component is charged all at once or continuously added dropwise, and at a reaction temperature of about 5 to 50 ° C. in the presence of a surfactant and a polymerization catalyst. It can be obtained by emulsion polymerization. The surfactant can be dissolved in the aqueous phase in advance, or can be added as a mixture with the monomer, and the polymerization catalyst can be added at the start of the polymerization or can be added dropwise during the polymerization. . As the surfactant, it is possible to use a cationic surfactant or a nonionic surfactant, and specific examples of the cationic surfactant include trimethyl octadecyl ammonium chloride, trimethyl dodecyl ammonium chloride, trimethyl hexadecyl ammonium chloride, Examples thereof include quaternary ammonium salts such as trimethylstearyl ammonium chloride, alkyldimethylbenzylammonium chloride and distearyldimethylammonium chloride. Specific examples of nonionic surfactants include polyethylene oxide type, sorbitan fatty acid ester type and oxy Examples thereof include ethylene oxypropylene block copolymer-based and polyoxyethylene sorbitan fatty acid ester-based surfactants. Further, as the polymerization catalyst, 2,2 '
-Azobis (2-amidinopropane) water-soluble salt, t-
Common water-soluble catalysts such as butyl hydroperoxide, saxonic acid peroxide, hydrogen peroxide and the like can be used.

The solid content of the chloroprene latex is not particularly limited, but it is usually suitable that the solid content is about 30 to 60% by weight and the viscosity is about 10 to 10,000 cps. The particle size of the chloroprene homopolymer or copolymer is preferably about 0.1 to 0.5 μm.

The cationic acrylic resin emulsion used in the present invention is obtained by copolymerizing at least one of alkyl acrylate and alkyl methacrylate with an amino group-containing acrylic monomer.

As the raw material alkyl acrylate and methacrylic acid alkyl ester, various types can be used. For example, specific examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate,
Butyl acrylate, 2-ethylhexyl acrylate, hydroxypropyl acrylate, β-ethoxyethyl acrylate, glycidyl acrylate and the like can be used. Further, specific examples of the methacrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, hydroxypropyl methacrylate,
Examples thereof include β-ethoxyethyl methacrylate and glycidyl methacrylate. These monomers can be used alone or in appropriate combination. In the present invention, other monomers copolymerizable with the acrylic acid alkyl ester or the methacrylic acid alkyl ester may be added for copolymerization, if necessary. Examples of such a monomer include vinyl-based monomers such as vinyl acetate, styrene, acrylonitrile, and vinyl chloride, which should be added up to about 1/1 (weight ratio) with respect to alkyl acrylate and alkyl methacrylate. You can

In order to obtain the cationic acrylic resin emulsion, it is necessary to carry out a polymerization reaction in the presence of an amino group-containing acrylic monomer which is a cationic monomer in order to impart a cationic property to the emulsion. The amino group-containing acrylic monomer has a general formula

[0015]

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(Wherein R ₁ is hydrogen or a methyl group, R ₂ is a C ₁ -C ₆ alkylene group, R ₃ and R ₄ are hydrogen or C
_An aminoalkyl (meth) acrylate represented by _{1 to} C ₆ alkyl group) and / or the general formula

[0017]

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(Wherein R ₁ is hydrogen or a methyl group, R ₂ is a C ₁ -C ₆ alkylene group, R ₃ and R ₄ are hydrogen or C
Can be used N- aminoalkyl (meth) acrylamide represented by an alkyl group having ₁ -C _6). The amount of the cationic monomer used may be determined according to the desired properties of the emulsion and is not particularly limited, but is usually 1 to 5% by weight with respect to all the monomers.
The degree is preferred.

Specific examples of the cationic monomer include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate and t as the aminoalkyl (meth) acrylate of the general formula (I).
-Butylaminoethyl acrylate, t-butylaminoethyl methacrylate, monomethylaminoethyl acrylate, monomethylaminoethyl methacrylate and the like can be mentioned. Examples of the N-aminoalkyl (meth) acrylamide of the general formula (II) include dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide and the like.

The cationic monomer is neutralized with an acid before use. The degree of neutralization (acid / cationic monomer (molar ratio)) is about 0.2 or more, and can be more than 1 depending on the application of the emulsion. Specifically, the higher the degree of neutralization, the higher the hydrophilicity, and the lower the degree of neutralization, the weaker the emulsifying power and the lower the polymerization stability. The degree of neutralization may be determined according to the properties and the amount used.

As the acid used for neutralization, various kinds of inorganic acids or organic acids can be used, and as the inorganic acid, hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc. can be used. Examples of the organic acid include: Formic acid, acetic acid, propionic acid, succinic acid, citric acid, malic acid and the like can be used.

A polymerization method for obtaining the cationic acrylic resin emulsion may be a usual emulsion polymerization method, for example, a method in which a main monomer, a cationic monomer and other raw materials are collectively charged and polymerized, and each component. Various methods such as a method of polymerizing while continuously supplying are possible, and any method can obtain a cationic emulsion that achieves the intended purpose. In the case of continuous supply, each component may be added alone, or any component may be mixed in advance and added. The polymerization reaction is
It may be carried out under heating and usually at a temperature of about 50 to 85 ° C.

In the above emulsion polymerization,
In order to secure the stability of the obtained emulsion, it is preferable to add a nonionic surfactant and / or a cationic surfactant. As the nonionic surfactant, a polyethylene oxide-based surfactant is preferable,
Specifically, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene sorbitan monolaurate, Examples thereof include polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and oxyethylene oxypropylene block polymer.

As the cationic surfactant, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, polyoxyethylated alkyl amine, amine oxide derivative, alkyl trimethylene diamine, distearyl dimethyl ammonium chloride, alkyl benzyl dimethyl ammonium chloride, 1 , Secondary or tertiary amine derivatives and the like can be exemplified.

Among these surfactants, HLB is particularly preferable in that it has good polymerization stability, mechanical stability and chemical stability.
It is preferable to use a polyethylene oxide-based nonionic surfactant having a value of 14 or less.

The amount of the surfactant used may vary depending on the properties required for the emulsion, but generally, the purpose is to improve the polymerization stability and suppress the generation of coarse particles, and the mechanical and chemical properties of the emulsion. For the purpose of improving the chemical stability and improving the cement miscibility, a large amount of the surfactant is preferably used, and in order to improve the water resistance of the dry film, a small amount is preferably used. Usually, the amount used may be determined according to the purpose from the range of about 1 to 10% by weight based on all the monomers.

In the production of the emulsion, both a general nonionic catalyst and a cationic catalyst can be used as a catalyst for the polymerization reaction.
It is preferable to use 2'-azobis (2-aminodipropane).

The concentration of the cationic acrylic resin emulsion is not particularly limited, but usually the solid content is 40 to 65.
The thing of about weight% is suitable.

In the polymer cement mortar composition of the present invention, it is necessary to use the chloroprene latex and the cationic acrylic resin emulsion in combination as the polymer dispersion component, and the mixing ratio of the chloroprene latex / acrylic resin emulsion is 25/75 to 75/25 by weight ratio (solid content)
The degree is suitable, and about 40/60 to 60/40 is preferable. When the compounding ratio of the chloroprene latex is less than the above range, the properties of the formed film such as weather resistance, heat resistance, and chemical resistance are inferior. On the other hand, when it exceeds the above range, the workability is deteriorated, and further dry-out. Is likely to occur, which is not preferable.

The blending amount of the polymer dispersion component consisting of the chloroprene latex and the cationic acrylic resin emulsion in the polymer cement mortar composition is such that the total solid content of the chloroprene latex and the cationic acrylic resin emulsion is 100 parts by weight of cement. On the other hand, it may be about 5 to 25 parts by weight, preferably about 10 to 15 parts by weight. If the blending amount of the polymer dispersion component is less than the above range, a sufficient addition effect cannot be exhibited, while if it exceeds the above range, the hardenability of cement is adversely affected, which is not preferable.

In the polymer cement mortar composition of the present invention, the cement component is not particularly limited, and various cements mixed in the conventional polymer cement mortar composition can be used. Specific examples of such cements include ordinary Portland cement, early strength Portland cement, super early strength Portland cement, moderate heat Portland cement, sulfate resistant Portland cement, Portland cement such as white Portland cement; blast furnace cement, silica cement, Mixed cements such as fly ash cements; special cements such as cement-based solidifying materials, alumina cements, ultra-rapid cements, expansion cements and the like can be mentioned, and they may be appropriately selected depending on the purpose of use.

In the polymer-cement mortar composition of the present invention, the aggregate is not particularly limited, and various kinds of aggregates to be blended with the conventional polymer-cement mortar composition can be used. For example, sand, silica sand, calcium carbonate. , Talc, pozzolan, mica, siliceous earth, titanium oxide, ferrite, carbon black and the like can be used. The particle size of the aggregate is not particularly limited, but it is usually preferable to use an aggregate having a particle size of about 1 μm to 5 mm.

The amount of the aggregate is appropriately 50 to 500 parts by weight, preferably 200 to 300 parts by weight, based on 100 parts by weight of cement.
If the content of the aggregate is less than the above range, shrinkage is likely to occur at the time of curing and it may cause cracks. On the other hand, if it exceeds the above range, the strength is lowered, which is not preferable.

The polymer cement mortar composition of the present invention contains the above-mentioned cement component, polymer dispersion component and aggregate as essential components, and further contains pigment, silica fume, mica, etc., if necessary. For the purpose of increasing the amount of inorganic fine powder, organic fine powder such as polystyrene resin and polyethylene resin, fibrous material such as asbestos, carbon fiber, glass fiber, etc., shrinkage prevention, crack prevention, etc. It can be added up to about parts by weight.

The polymer cement mortar composition has a total water content of 40 to 1 with respect to 100 parts by weight of cement.
It is suitable to add water so as to be used in a range of about 00 parts by weight.

The polymer-cement mortar composition of the present invention can be used in the same applications as ordinary polymer-cement mortar compositions. For example, adhesive mortar such as tiles, undercoat material for outer walls, floors, etc. It can be suitably used for applications such as a material for preventing deterioration (deterioration), a food material, and a waterproof material for marine structures. The usage method may be the same as the conventional one. Usually, after applying by a method such as ironing or spraying, it can be cured by drying in the atmosphere for about 24 to 48 hours.

[0037]

EFFECT OF THE INVENTION The polymer cement mortar composition of the present invention is easy to apply and has excellent adhesion to the substrate, and the formed film has good properties such as weather resistance, heat resistance and chemical resistance. Thus, it has excellent characteristics that it is in a good cured state with no cracks and that dry-out does not occur even when the base is concrete.

[0038]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 A cationic acrylic resin emulsion was prepared by the following method.

First, 125 parts by weight of nitrogen-exchanged ion-exchanged water was added to a separable flask equipped with a stirring blade, a condenser and a thermometer, and then 3.5 parts by weight of HLB 12.8 polyoxyethylene nonylphenyl ether. Added and dissolved. Next, add 75% of this surfactant solution.
Keeping at ℃, as amino group-containing acrylic monomer,
After adding 2 parts by weight of dimethylaminoethyl methacrylate, 1.6 parts by weight of 36% hydrochloric acid diluted with ion-exchanged water to a hydrochloric acid concentration of 18% were added and mixed well to neutralize the amino group-containing acrylic monomer. After that, 0.7 parts by weight of a 14% aqueous solution of 2,2'-azobis (2-amidinopropane) dihydrochloride was added. Then, continuous dropwise addition of 98 parts by weight of a 1/1 (weight ratio) mixed liquid of methyl methacrylate and 2-ethylhexyl acrylate was started. Keep the inside of the flask at 78 ° C ± 2 ° C with a water bath,
The dropping of the monomer mixture solution was completed in 4 hours. After the completion of the monomer mixture droplets, 0.7 parts by weight of a 14% aqueous solution of 2,2′-azobis (2-amidinopropane) dihydrochloride was added to the flask to adjust the temperature in the flask to 82 ° C. ± 2 ° C. for 2 hours. After standing, it was cooled to obtain a cationic emulsion having a resin concentration of 45%.

The cationic chloroprene latex, which is commercially available under the trade name of Neoment 102M (manufactured by Showa Denko DuPont Co., Ltd.), contains chloroprene polymer as a main component, has a viscosity of 3,200 cps, a pH of 7, and a solid content of 45%. Was used.

The above-mentioned cationic acrylic resin emulsion (solid content: 45%) and chloroprene latex (solid content: 45%) were mixed at a weight ratio of 1: 1 to prepare a polymer dispersion component. 22 parts by weight of this polymer dispersion component Based on (solid content), 100 parts by weight of Portland cement, 300 parts by weight of silica sand No. 5 and 3 parts of water
8 parts by weight were added and mixed well to obtain a polymer cement mortar composition.

The results of measuring various characteristics of the obtained polymer cement mortar composition are shown in Table 1 below.
Also, using this composition, the diameter is 48 mm and the height is 40 mm.
After making a cylindrical sample of, and leaving it at room temperature for 28 days,
The results of measuring various characteristics are also shown in Table 1 below. For comparison, a polymer cement mortar composition (Comparative Example 1) using 22 parts by weight of chloroprene latex alone instead of the 1: 1 mixture of the cationic acrylic resin emulsion and chloroprene latex and the cationic acrylic resin emulsion alone were used. The same test was performed for the polymer cement mortar composition (Comparative Example 2) used in an amount of 22 parts by weight. The test method is as follows.

* Flow value: JIS R 5201 9.
It measured according to the method shown in the 7 flow test.

* Workability: Using a plaster finish trowel, it was applied to a concrete floor with a coating thickness of 5 mm,
The iron separating property and the final pressing iron property were evaluated. The evaluation criteria were ◯ when the workability was good, X when the workability was impossible, and Δ when the workability was intermediate.

* Dry cracks: The presence or absence of cracks in the cured product was visually evaluated.

* Finished surface condition: The appearance of the cured product was visually evaluated according to the following criteria.

○ Good appearance × Fine irregularities * Adhesive strength Measured according to JIS A 6203.

* Acid resistance: cured product in 2% sulfuric acid at room temperature
After dipping for one day, washing with water for one day, wiping with a compress, the weight was measured, and the acid absorption rate was calculated by the following formula.

Acid absorption rate (%) = (weight after immersion−weight before immersion) × 100 / weight before immersion Further, the sample after the acid absorption rate was left for 7 days, and then the compressive strength was measured. .

* Alkali resistance: The cured product was immersed in 45% sodium hydroxide at room temperature for 7 days, washed with water for 1 day, wiped with a compress and weighed, and the alkali absorption rate was calculated by the following formula. .

Alkali absorption rate (%) = (weight after immersion−weight before immersion) × 100 / weight before immersion Further, the sample after the measurement of the alkali absorption rate was left for 7 days, and then the compression strength was measured. .

* Water resistance: The cured product was immersed in water at room temperature for 7 days, then wiped with a compress to measure the weight, and the water absorption rate was calculated by the following formula.

Water absorption rate (%) = (weight after immersion−weight before immersion) × 100 / weight before immersion Further, the sample after the water absorption rate was left for 7 days, and then the compressive strength was measured.

[0055]

[Table 1]

From the above results, the polymer-cement mortar composition of the present invention has good workability and good finished state of the cured product. Regarding chemical resistance, when chloroprene latex is used alone (Comparative Example 1). It can be seen that it is even better than).

[0057]

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Claims (2)

[Claims] 1. A cationic acrylic resin emulsion obtained by copolymerizing at least one of acrylic acid alkyl ester and methacrylic acid alkyl ester with an amino group-containing acrylic monomer, and a chloroprene latex. The weight ratio of the quantity is 25/7
Polymer dispersion for polymer cement mortar composition, which is 5 to 75/25. 2. (i) 100 parts by weight of cement, (ii) aggregate 50
˜500 parts by weight, and (iii) a cationic acrylic resin emulsion obtained by copolymerizing at least one of acrylic acid alkyl ester and methacrylic acid alkyl ester and an amino group-containing acrylic monomer, and a chloroprene latex. A polymer cement mortar composition comprising 5 to 25 parts by weight (solid content) of a polymer / polymer dispersion component having a weight ratio of the solid content of the latter of 25/75 to 75/25.