JP2640765B2 - Method for producing polymer cement mortar composition and cured product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a polymer cement mortar composition useful as a building material such as a ceiling material and a wall material, and a coating material for a concrete building, and a method for producing a cured product thereof.

[Prior art]

Portland cement, early strength Portland cement,
100 parts by weight of hydraulic cement such as magnesia cement and fly ash cement, and filler 1 such as extender and silica sand
00-500 parts by weight (possibly with cement only) and water,
Depending on the case, a cement mortar obtained by adding an appropriate admixture to the mixture and kneading the mixture is conventionally widely used as a covering material for building walls or floors, and further, the mechanical strength of the cement mortar, Emulsion resin is mixed in to improve various properties such as adhesion to the wall, efro resistance, dryout resistance, water resistance, chemical resistance, abrasion resistance, dimensional stability, followability to wall deformation, etc. Resin cement mortars have been used as well. The above-mentioned conventional cement mortar containing a resin is merely a mixture of an emulsion resin obtained by an ordinary emulsion polymerization method as it is in the cement mortar, so that the above-mentioned properties of the cement mortar can be improved, However, there is a problem that the workability is significantly impaired and the work efficiency and the finished appearance are adversely affected. For example, when a cement mortar containing resin is applied to a building wall or floor, iron coating is generally performed. In this case, the adhesiveness of the emulsion resin mixed causes the iron mortar to be hardly detached from the cement mortar. Is difficult to obtain, and skinning of the emulsion resin on the surface occurs in a relatively short time, so that it is difficult to repair unevenness. The phenomenon of skinning of this emulsion resin is
When the polymer cement mortar composition is diluted with water in order to facilitate spray coating and casting, it easily occurs because the resin emulsion layer and the cement mortar layer are separated due to a difference in specific gravity. When the polymer cement mortar composition diluted with water is allowed to stand in a container as shown in FIG. 2 of the accompanying drawings, it is divided into two layers, the lower layer comprising resin particles of the emulsion and hydraulic cement, the filler and the water Is mixed with polymer cement mortar layer 1, the particle size of the floating upper layer is 0.05 ~
It becomes an aqueous dispersion layer 2 of resin particles of an emulsion of about 0.2 μm. This is because when the coated polymer cement mortar composition dries, the water on the upper layer is scattered and the water separation layer 2 is formed on the surface of the polymer cement mortar layer 1. Therefore, in order to prevent the separation of the emulsion, a water-soluble polymer such as starch, casein, carboxymethylcellulose, and galactomannone (also a thickener and a protective colloid) is added to the polymer cement mortar with polyvinyl alcohol. Things are going on. However, even if this water-soluble polymer is added, the effect of preventing the surface of the emulsion resin from skinning is not sufficient, and the gelling agent (borate, tannic acid, , Titanium lactate, etc.) in a resin aqueous emulsion to cause gelation and insolubilize this water-soluble polymer. A polymer containing resin emulsion particles encapsulated in a gelled film as a resin component in cement mortar A cement mortar composition has been proposed (see JP-A-63-21246). Although the polymer cement mortar composition has improved iron separation from the cement mortar, the polymer cement mortar composition has a high clay and the coatability such as iron coating, spray coating and brush coating has not been improved. Dilution with water in order to improve paintability results in layer separation of the emulsion.

[Problems to be solved by the invention]

The present invention has solved the above-mentioned problems with the conventional resin-containing cement mortar, and its object is to provide a polymer cement mortar composition that can be freely diluted with water and that hardly causes separation of an emulsion resin from the cement mortar. And a method for producing a cured product thereof.

[Means for Solving the Problems]

In the present invention, the copolymer particles of the emulsion by forming the chelate compound by adding calcium ion or magnesium ion forming a chelate compound to the anionic surfactant used in the production of the emulsion to the polymer cement mortar Is precipitated, cement particles, in some cases also adhere to the filler, thereby cementing the emulsion copolymer particles,
It is intended to prevent the separation of the filler and the copolymer particles from the mixed system as much as possible and to prevent the film from sticking. By the way, an anionic resin emulsion can be precipitated by adding a flocculant (for example, a sulfuric acid band) or a cationic surfactant, and these react rapidly with the anionic surfactant to form a chelate by the addition. In the above, calcium ions or magnesium ions react slowly, and the precipitation and adhesion of the resin are performed more uniformly, and the performance of the polymer cement mortar is stabilized. In order to achieve the above object, a polymer cement mortar composition characterized by the present invention comprises a hydraulic cement (A) 100 parts by weight in the presence of an anionic surfactant which forms a chelate compound with a polyvalent metal ion. The carboxyl group (-COOH) concentration obtained by emulsion polymerization of the monomer mixture is 0 to 0.
7% by weight anionic copolymer aqueous emulsion (B)
3 to 30 parts by weight in terms of the solid content of the copolymer 10 to 150 parts by weight of an inorganic compound which generates calcium ions or magnesium ions in water Filler (D) 0 to 490 parts by weight [However, the component (C) The sum of the components (D) is 10 to 500 parts by weight. ] The components (A), (B), (C) and (D) are blended in the above proportions. Further, the method for producing a cured polymer cement mortar characterized by the present invention is characterized in that a hydraulic cement (A) 100 parts by weight A vinyl monomer is used by using an anionic surfactant for forming a chelate compound by calcium ions or magnesium ions. A copolymer aqueous emulsion obtained by emulsion polymerization of a mixture, wherein the carboxyl group concentration in the copolymer is from 0 to 0.7% by weight (B). [However, the amount of the anionic surfactant used per 100 parts by weight of the copolymer is 0.6 to 2.5 parts by weight in terms of solid content. ] Inorganic compound (C) that generates calcium ions or magnesium ions in water 10 to 150 parts by weight Filler (D) 0 to 490 parts by weight [However, the sum of the components (C) and (D) is 10 to 500 parts by weight. Department. After adding the component (C) to the polymer cement mortar composition containing the components (A), (B) and (D),
The hydraulic reaction is carried out by casting or casting at a temperature 5 ° C. or more lower than the glass transition point of the emulsion of the component (B). The above configuration will be described more specifically. [Hydraulic Cement (A)] As the hydraulic cement of the component (A), ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, jet cement, white cement, blast furnace slag cement, silica cement and the like can be used. [Aqueous Anionic Copolymer Emulsion] The aqueous emulsion of the anionic copolymer (B) is obtained by emulsion-polymerizing a vinyl monomer using an anionic surfactant which forms a chelate compound with calcium ions or magnesium ions. An aqueous copolymer emulsion obtained, wherein the carboxyl group concentration in the copolymer is 0%.
~ 0.7% by weight of an aqueous anionic copolymer emulsion. However, the amount of the anionic surfactant used per 100 parts by weight of the copolymer is 0.6 to 2.5 parts by weight in solid form. Here, the carboxyl group concentration in the copolymer is represented by the weight% of the constituent units based on the α, β-unsaturated acid in the copolymer with respect to the total weight of the vinyl monomer forming the copolymer. As the α, β-unsaturated acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, crotonic acid, maleic anhydride and the like are used. When the α, β-unsaturated acid is such as acrylic acid, itaconic acid, fumaric acid, and maleic anhydride that give a copolymer having a large number of carboxyl groups on the surface of the copolymer particles, the carboxyl group concentration Is less than 0.1% by weight, and when giving a copolymer such as methacrylic acid in which a large amount of carboxyl groups are present inside the copolymer particles, the carboxyl group concentration becomes 0.7% by weight or less. Thus, the amount of the α, β-unsaturated acid used in the emulsion polymerization is adjusted. Ca ⁺⁺ and Mg ⁺⁺ generated from the component (C) react with an anionic surfactant to form a chelate compound, and the copolymer particles of the emulsion having a carboxyl group also trap these ions. To form a chelate. Therefore, the chelating reaction with the anionic surfactant is delayed, and when the gypsum in the cement of the component (A) or the calcium salt of the component (C) is gypsum, the hydration hardening reaction of the gypsum is also delayed. Therefore, the resin of the aqueous emulsion of the anionic copolymer (B) is preferably one in which a carboxyl group does not exist on the particle surface as much as possible or does not have an acid group. Α, β- such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride, crotonic acid
When an unsaturated carboxylic acid is used, it is used so that the concentration of the carboxyl group in the copolymer is equal to or less than the above concentration. If the concentration is exceeded, Ca ⁺⁺ or Mg ⁺⁺ will be eaten by the resin of the aqueous emulsion in a large amount, and the time required for the hydration reaction of cement or gypsum will be long. The component (C) Ca ⁺⁺ or Mg ⁺⁺ is ion-exchanged with an ammonium ion or a metal ion such as K ⁺ , Na ⁺ Li ^{+ and the} like for the emulsifier to form a chelate. It becomes a salt or a calcium salt of an organic carboxylate, which lowers its surface activity and destroys the emulsion. The copolymer particles coagulate, coagulate and adhere to the cement. This component (C) is added to 100 parts by weight of cement. Ten
100100 parts by weight, about three times the amount of the copolymer particles of the emulsion. Examples of the emulsifier include organic sulfonic acid sodium salts such as sodium laurate sulfonate, sodium stearate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfonate, sodium alkane sulfonate, and sodium alkylbenzene sulfonate. Fatty acid metal salts such as aliphatic soaps, fatty acid sarcosides, and rosin acid soaps; sulfate-type anionic surfactants or fatty acid derivatives having K ⁺ , NH ⁺ and alkanolamine ions in place of Na ⁺ can be used. These anionic emulsifiers are used in a proportion of 0.6 to 2.5 parts by weight in solid content based on 100 parts by weight of the copolymer of the obtained aqueous emulsion. If the amount is larger than the above range, partial or no aggregation of the copolymer particles, which is expected to have a small destructive action of the emulsifier, will not occur, and the cement, gypsum and hydration hardening reaction will be inhibited. On the other hand, when the amount is small, the polymerization stability and storage stability of the aqueous copolymer emulsion are low, the aggregation of the copolymer particles is fast, and the mixing stability with the cement and the filler is problematic. That is, if the amount is less than 0.6 parts by weight, the generation of aggregates of the copolymer particles and the speed of aggregation are increased, and it is difficult to mix the aqueous emulsion of the copolymer and the copolymer with the cement and the filler, and water, and the resin emulsion is added to the cement mortar. And the performance of the resulting cured polymer cement mortar is not constant. Furthermore, emulsion polymerization at the time of emulsion production becomes difficult. On the other hand, if it exceeds 2.5 parts by weight, it takes time for the aggregation and coagulation of the copolymer particles of the emulsion, and depending on the constituent components of the copolymer of the emulsion, a part of the copolymer emulsion may become a polymer cement mortar layer (lower layer). 1) forming an aqueous dispersion layer (upper layer) 2 separated from 1 (see FIG. 2);
The aqueous anionic copolymer emulsion is not effectively used. A nonionic surfactant such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, or polyoxyethylated castor oil may be used together with the anionic emulsifier. The nonionic emulsifier is not subjected to agglomeration by Ca ⁺⁺ and Mg ^++, and has the power to protect stabilize than the copolymer resin particles Ca ⁺⁺ and Mg ^++. Further, it is stable and effective at the time of polymerization of the resin emulsion, and is effective as a dispersant for the filler. However,
If it is used in excess of 2%, a portion of the resin emulsion cannot be aggregated, so it is better to use as little as possible. For this reason, it is preferable to mix a nonionic emulsifier during or after polymerization in the range of 0 to 2% based on the copolymer particles of the component (B). As a vinyl monomer to give an anionic copolymer,
Alkyl acrylates, alkyl methacrylates (there are 1 to 8 carbon atoms in these alkyl groups); 2-hydroxyethyl acrylate, 2hydroxypropyl acrylate and their methacrylate equivalents; acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, Ester such as ethylene, acrylonitrile, methyl methacrylate, vinyl acetate, styrene, acrylic acid,
Methacrylic acid, itaconic acid, fumaric acid, crotonic acid, maleic anhydride and the like can be used, and two or more of these vinyl monomers are selected, and the glass transition point of the copolymer particles of the obtained aqueous emulsion is preferably The vinyl monomer is selected so that the temperature is −30 ° C. to + 30 ° C., and the amount of the carboxyl group in the copolymer is in the range described above. In addition, what is called a reactive emulsifier, such as sodium vinyl sulfonate, is handled as an anionic emulsifier if it is an anion. Emulsion polymerization is carried out by a usual method, and the concentration of the resin solid component in the obtained aqueous copolymer emulsion is 20 to 65% by weight, and the particle size of the copolymer particles is 0.03%.
~ 3 microns is common. The amount of the aqueous anionic copolymer aqueous emulsion greatly depends on the type of the vinyl monomer constituting the copolymer, but generally, the hydraulic cement of the component (A) is used.
It is 3 to 30 parts by weight on a solid basis with respect to 100 parts by weight. If the amount exceeds 30 parts by weight, a large amount of Ca ⁺⁺ or Mg ⁺⁺ generated from the component (C) necessary for coagulation of the emulsion resin is required, and the increase in the component (C) depends on the ratio to the hydraulic cement. The original performance of the mortar will be lost. Further, the improvement of the waterproofness of the aqueous emulsion to the cured polymer cement mortar cannot be expected any more, and there is little merit of using a large amount of expensive emulsion. On the other hand, if it is less than 3 parts by weight, a uniform polymer cement mortar cannot be obtained. The amount of the component (B) used for the cement of the component (A) depends largely on the type of the vinyl monomer constituting the copolymer of the emulsion as described above, and generally includes an acid group, a hydroxyl group, and an amide. Those having a functional group such as a group tend to have a lower upper limit of the amount used than a copolymer having no such functional group. [Inorganic Compound] As the inorganic compound of the component (C), calcium and magnesium sulfates, chlorides, carbonates, hydroxides, oxides, etc., generate Ca ⁺⁺ and Mg ⁺⁺ ions in water. Things can be used. Specifically, gypsum, quicklime, magnesium oxide,
Calcium carbonate or the like is used. These are used in an amount sufficient to break the emulsion of component (B). [Water] Water contributes to the hydration-hardening reaction of the cement and also serves as a dispersion medium for the cement and the filler until the cement hardens. And water is 30 to 1 per 100 parts by weight of cement.
It is used so as to be 00 parts by weight, preferably 35 to 70 parts by weight. However, in the present invention, since the resin component of the emulsion is deposited and attached to the cement and the filler, it cannot be separated even if diluted, so that a large amount of water may be used and the flow is very large, in other words, A polymer cement mortar composition having good workability is obtained. [Filler] As the filler of the component (D), fine aggregates such as silica sand, extenders such as titanium oxide and clay, coloring pigments such as iron oxide and chromium oxide, talc, crushed stone, lightweight aggregates and fibers Etc. can be used. [Cement mortar] Cement mortar is a component (A) cement, (D)
It is a mixture obtained by adding a filler of the component and an appropriate amount of water thereto and kneading the mixture. Various additives (synthetic resin, water reducing agent, air entraining agent, etc.) can be used in the cement mortar as needed. [Polymer cement mortar composition] The polymer cement mortar is prepared by adding an emulsion of the component (B) to a cement mortar of the cement of the component (A), the filler of the component (D) and water, and the component (C). Is added. It is also prepared by adding an emulsion of the component (B) to a cement mortar mixed with the component (C). The application (application) and casting are performed at a temperature lower than the glass transition point (Tg) of the copolymer particles of the emulsion by 5 ° C. or more to prevent fusion of the aggregated emulsion copolymer particles. The applied or cast polymer cement mortar generates heat due to the hydraulic reaction of the cement, and if heated, the copolymer particles are fused to form a tough film or molded body. Then, the Tg of the emulsion copolymer is set to 40
° C or lower, preferably 20 ° C or lower, a cured product of polymer cement mortar can be obtained without steam curing even in winter, but steam curing may be performed in order to express the strength of the cured product early. . The setting time of the polymer cement mortar is usually about 6 hours, so that the strength of the cement becomes portable. After that, the hydraulic reaction of the cement proceeds to improve the compressive strength, and the compressive strength becomes almost saturated in 7 to 30 days. After curing, a cured polymer cement mortar having sufficient compressive strength can be obtained in about one day.

[Examples]

Hereinafter, the present invention will be described in more detail with reference to examples and the like.
The parts and percentages in the examples are on a weight basis unless otherwise specified. Production Example of Aqueous Resin Emulsion Example 1 The following raw materials were charged into a reaction vessel equipped with a temperature controller, an anchor stirrer, a reflux condenser, a supply vessel, a thermometer, and a nitrogen inlet tube. 200 parts of water 35% aqueous solution of sodium salt of sulfuric acid half ester of p-nonylphenol (anionic emulsifier a) reacted with 20 moles of ethylene oxide 3.9 parts Then, after replacing the inside of the reaction vessel with nitrogen gas, the following feed 10% of I was added and the mixture was heated to 90 ° C. Feed I Water 200 parts 35% aqueous solution of the anionic emulsifier 19 parts Styrene 192 parts N-butyl acrylate 194 parts Acrylamide 14 parts Further, 2.5 parts of potassium sulphate dissolved in 85 parts of water (Feed II) ) Is charged into the reaction vessel, and all the remaining feed I and 90% of the feed II are fed into the reaction vessel over 3.5 hours. After the feed is completed, the temperature is maintained at the same temperature for 2 hours. Feed I was polymerized to give an aqueous anionic resin emulsion (Tg + 17 ° C.) having a —COOH content of 0% by weight. Examples 2 to 17 Aqueous emulsions of copolymer particles having the physical properties shown in Table 1 were obtained by changing the type of vinyl monomer and the type and amount of emulsifier as shown in Table 1 below. The nonionic emulsifier was initially charged into the reaction vessel. Example 1 100 parts by weight of ordinary Portland cement, standard silica sand 300
A polymer cement mortar composition was prepared by mixing 20 parts by weight of the aqueous emulsion of anionic resin obtained in Example 1 with a mortar slurry containing 150 parts by weight of water and 150 parts by weight of water, and then adding 30 parts by weight of α-gypsum. The dispersion state was as shown in FIG. 1, and there was no layer separation. And the following evaluation was performed about this polymer cement mortar composition. Ironing workability: The ironing property and uniform application property when the polymer cement mortar composition was ironed at the temperatures shown in Table 1 below were investigated. Flexural strength: According to JIS R-5201 (after 28 days) Water dilutable 40 parts by weight of water was added to 100 parts by weight of the polymer cement mortar composition, mixed by stirring for 5 minutes, and allowed to stand for 30 minutes to determine the presence or absence of layer separation. Examined. Good: single-layer state shown in FIG. 1 Poor: two-layer state shown in FIG. 2 Examples 2 to 10, Comparative Examples 1 to 6 In Example 1, the composition of the polymer cement mortar was as shown in Table 2 below. A polymer cement mortar composition was prepared and evaluated in the same manner except that the composition was changed to. The results are shown in the same table. Examples 11 to 23, Comparative Examples 7 to 12 In the same manner as in Example 1, except that the emulsion shown in Table 3 below was used instead of the emulsion of Example 1,
A polymer cement mortar composition having the following composition was prepared and evaluated. 100 parts by weight of ordinary Portland cement 20 parts by weight of emulsion 30 parts by weight of gypsum 30 parts by weight of silica sand with No. 5 silica sand (1/1) 300 parts by weight Water 35 parts by weight The results are shown in Table 3. Example 24 The procedure of Example 1 was repeated except that an additional 20 parts of yellow iron oxide were used as the colorant. In this example, the dispersion state, water dilutability, ironing workability and the like were good. Example 25 The composition after water dilutability evaluation in Example 23 was poured with placing filter paper on it, and filtered under reduced pressure by a water jet pump. The filtrate was transparent, and there was no particular problem in filtration. ) Was cured by heating at 80 ° C. and 90% humidity for 3 days to obtain a cured polymer cement mortar having a bending strength of 136 kg / cm ² . In the case of Comparative Example 1, no matter how the water was diluted, the white water of the emulsion became a filtrate at first, and after a little removal, the filtration became impossible.

【The invention's effect】

The present invention is as described above.
As is apparent from the above, the composition has improved properties. And can be freely diluted with water,
In addition, the present invention can provide a polymer cement molar composition having almost no emulsion separation than cement mortar.

[Brief description of the drawings]

1 and 2 are cross-sectional views each showing a dispersed state of the polymer cement mortar composition.

Claims (2)

(57) [Claims] (1) 100 parts by weight of hydraulic cement (A) Carboxyl group obtained by emulsion polymerization of a vinyl monomer mixture in the presence of an anionic surfactant which forms a chelate compound with polyvalent metal ions (-COOH) concentration of 0 to 0.
7% by weight anionic copolymer aqueous emulsion (B)
3 to 30 parts by weight in terms of the solid content of the copolymer 10 to 150 parts by weight of an inorganic compound which generates calcium ions or magnesium ions in water Filler (D) 0 to 490 parts by weight [However, the component (C) The sum of the components (D) is 10 to 500 parts by weight. ] A polymer cement mortar composition comprising the components (A), (B), (C) and (D) mixed in the above proportions. 2. An aqueous emulsion of a copolymer obtained by emulsion-polymerizing a vinyl monomer mixture using an anionic surfactant which forms a chelate compound with calcium ions or magnesium ions. Wherein the carboxyl group concentration in the copolymer is from 0 to 0.7% by weight, and the aqueous emulsion of the anionic copolymer (B) has a copolymer solid content of 3 to 30 parts by weight [provided that the copolymer 100 The amount of the anionic surfactant to be used is 0.6 to 2.5 parts by weight based on the solid part. ] Inorganic compound (C) that generates calcium ions or magnesium ions in water 10 to 150 parts by weight Filler (D) 0 to 490 parts by weight [However, the sum of the components (C) and (D) is 10 to 500 parts by weight. Department. After adding the component (C) to the polymer cement mortar composition containing the components (A), (B) and (D),
(B) A method for producing a hardened polymer cement mortar, which comprises applying or casting at a temperature 5 ° C. or lower than the glass transition point of the emulsion of the component to cause a hydraulic reaction.