JPH02107544A - Production of polymer cement mortar composition and hardened body thereof - Google Patents

Abstract

PURPOSE:To obtain a mortar compsn. capable of being freely diluted with water and hardly causing the separation of emulsion resin by blending hydraulic cement with a specified aq. anionic copolymer emulsion, an inorg. compd. and a filler. CONSTITUTION:This compsn. consists of 100pts.wt. hydraulic cement (A), 3-30pts. wt. (expressed in terms of solid matter) aq. anionic copolymer emulsion (B) having 0-0.7wt.% concn. of carboxyl groups obtd. by emulsion-polymerizing a vinyl monomer mixture in the presence of an anionic surfactant forming a chelate compd. with a multivalent metal ion, 10-150pts.wt. inorg. compd. (C) generating Ca or Mg ion in water and 0-490pts.wt. filler. The total amt. of the components C, D is 10-500pts.wt.

Description

[Detailed description of the invention] [Industrial application field]

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

[Prior art] Hydraulic cement such as Portland cement, early-strength Portland cement, magnesia cement, and fly ash cement is added to 100 to 500 parts by weight of fillers such as extender pigments and silica sand (in some cases, only cement is used). ) and water, and in some cases, appropriate admixtures are added and mixed to make cement mortar, which has been widely used as a covering material for walls and floors of buildings, and furthermore,
The mechanical strength of this cement mortar, its adhesion to the wall,
The same goes for resin-containing cement mortar mixed with emulsion resin in order to improve various properties such as efflorescence resistance, dryout resistance, water resistance, chemical resistance, abrasion resistance, one-dimensional stability, and ability to follow wall deformation. It is used in The above-mentioned conventional resin-containing cement mortar is simply a mixture of emulsion resin obtained by normal emulsion polymerization method into cement mortar, so although the above characteristics of cement mortar can be improved, the process is difficult. There are problems in that it significantly impairs performance and has an adverse effect on work efficiency and finished appearance. For example, when applying resin-containing cement mortar to the walls or floors of a building, the inside of the membrane is troweled. In this case, due to the stickiness of the emulsion resin mixed in,
Cement mortar does not easily separate from the trowel, making it difficult to obtain a smooth surface, and the emulsion resin on the surface develops a skin over a relatively short period of time, making it difficult to correct unevenness. This skinning phenomenon of emulsion resin is caused by the fact that when a polymer cement mortar composition is diluted with water to facilitate troweling, spray painting, and casting, the resin emulsion layer and cement mortar layer separate due to the difference in specific gravity. This is more likely to occur. As shown in Figure 2 of the attached drawings, when a polymer cement mortar composition diluted with water is allowed to stand still in a container, it separates into two layers, and the lower layer consists of emulsion resin particles and hydraulic cement, filler and water. Polymer cement mortar layer mixed with 1. The particle size of the upper layer floating is 0.0
This becomes a water-dispersed layer 2 of emulsion resin particles of about 5 to 0.2 microns. This is because when the coated polymer cement mortar composition dries, the water on the upper layer side scatters, and the water separation layer 2 is formed on the surface of the polymer cement mortar layer 1. ° Therefore, to prevent emulsion separation, water-soluble polymers (which are also thickeners and protective colloids) such as polyvinyl alcohol, starch, casein, carboxymethyl cellulose, galactomannone, etc. are added to the polymer cement mortar. things are being done. However, even when this water-soluble polymer is added, the effect of preventing the emulsion resin on the surface from forming a skin is not sufficient. , titanium lactate, etc.) is blended into an aqueous resin emulsion to cause gelation, and this water-soluble polymer is insolubilized.Resin emulsion particles encapsulated with a gelling film are included as a resin component in cement mortar. Polymer cement mortar compositions have been proposed (see JP-A-63-21246). This polymer cement mortar composition has improved trowel separation compared to cement mortar, but the viscosity of the polymer cement mortar composition is high, making it difficult to apply with a trowel.
Spraying does not have improved coating properties such as painting or brushing. When diluting with water to improve paintability, layer separation of the emulsion occurs.

Problems to be Solved by the Invention) The present invention solves the above-mentioned problems of the conventional resin-containing cement mortar, and its purpose is to make emulsion resin more easily diluted with water than cement mortar. An object of the present invention is to provide a polymer cement mortar composition in which almost no separation occurs, and a method for producing a cured product thereof. [Means for Solving the Problems] In the present invention, by adding calcium ions or magnesium ions that form a chelate compound with an anionic surfactant used in the production of an emulsion to a polymer cement mortar, the chelate Cement of the emulsion copolymer particles by precipitating the copolymer particles of the emulsion by forming a compound and adhering to the cement particles and possibly also the filler;
This is to prevent separation of the filler and 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, sulfuric acid) or a cationic surfactant, and when these are added, they rapidly react with the anionic surfactant to form a chelate. In this case, calcium ions or magnesium ions react slowly, the resin is deposited and adhered more evenly, 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) in the presence of an anionic surfactant that forms a chelate compound with 100 parts by weight of a polyvalent metal ion. The carboxyl group (-COOH) concentration obtained by emulsion polymerization of the monomer mixture is O
~0.7% by weight of anionic copolymer aqueous emulsion (B) 3 to 30 parts by weight of copolymer solids Inorganic compound that generates calcium ions or magnesium ions in water (C) 10 to 150 parts by weight Material (D) 0 to 490 parts by weight [However, the sum of component (C) and component (D) is 0 to 500 parts by weight. ] The above components (A), (B), (C) and (D) are blended in the above proportions. In addition, the method for producing a cured polymer cement mortar, which is a feature of the present invention, is as follows: Hydraulic cement (A) 100 parts by weight An anionic surfactant that forms a chelate compound with calcium ions or magnesium ions is used to produce a vinyl monomer. An aqueous copolymer emulsion obtained by emulsion polymerization of a mixture, wherein the carboxyl group cancer degree in the copolymer is 0 to 0.7% by weight. Copolymer (B) 3 to 30 parts by weight in terms of solid content [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 components (C) and (D) is 10 to 500 parts by weight Department. ] After adding the above component (C) to the polymer cement mortar composition containing the above components (A), (B) and (D), (B)
) The product is applied or cast at a temperature 5° C. or more lower than the glass transition point of the emulsion of the component (2) to cause a hydraulic reaction. The above configuration will be explained in more detail. [Hydraulic Cement (A)] As the hydraulic cement for component (A), ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, jet cement, white cement, blast furnace slag cement, silica cement, etc. can be used. [Anionic copolymer aqueous emulsion] Component (B), the anionic copolymer aqueous emulsion, is produced by emulsion polymerization of vinyl monomers using an anionic surfactant that forms a chelate compound with calcium ions or magnesium ions. The resulting copolymer aqueous emulsion,
The carboxyl group concentration in the copolymer is 0 to 0.7% by weight
It is an anionic copolymer aqueous emulsion. However, the amount of 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. Here, the carboxyl group concentration in the copolymer is expressed as the weight percent of the constituent units based on α,β-unsaturated acids in the copolymer based on the total weight of the vinyl monomers forming the copolymer. Examples of α,β-unsaturated acids include acrylic acid and methacrylic acid. Fumaric acid, itaconic acid, crotonic acid, maleic anhydride, etc. are used. When the α,β-unsaturated acid is one that provides a copolymer with many carboxyl groups present on the surface of the copolymer particles, such as acrylic acid, itaconic acid, fumaric acid, or maleic anhydride, the carboxyl group concentration When providing a copolymer such as methacrylic acid in which many carboxyl groups exist inside the copolymer particles, the carboxyl group concentration should be less than 0.1% by weight.
The amount of α,β-unsaturated acid used in emulsion polymerization is adjusted so that it is 7% by weight or less. Ca''+ and Mg'' generated from component (C) react with the anionic surfactant to produce a chelate compound, but the emulsion copolymer particles having carboxyl groups also capture these ions. Forms a chelate. Therefore, it is possible to delay the chelate reaction with the anionic surfactant, or to delay the chelate reaction with the anionic surfactant, and to
) If the calcium salt component is gypsum, it will also delay the hydration hardening reaction of the gypsum. The resin of the aqueous anionic copolymer emulsion of component (B) preferably has as few carboxyl groups as possible on the particle surface or does not have acid groups. When using α,β-unsaturated carboxylic acids such as acrylic M, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride, crotonic acid, etc. as the vinyl monomer, the carboxyl group concentration in the copolymer must be the same as mentioned above. Use so that the concentration is below. Above this concentration, Ca"+ and Mg"
is eaten up by the resin in the aqueous emulsion, and the time required for the hydration reaction of cement and gypsum increases. Component (C) Ca and Mg are ion-exchanged and chelated with ammonia ions and metal ions such as K", Na", and Li+ in the emulsifier. It becomes an acid calcium salt, reduces its surfactant ability and breaks the emulsion, and the copolymer particles coagulate, coagulate, and adhere to the cement. Component (C) is used in an amount of 10 to 100 parts by weight per 100 parts by weight of cement, which is about three times the amount of copolymer particles in the emulsion. Examples of emulsifiers include sodium organic sulfonic acid salts such as sodium laurate sulfonate, sodium stearate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfonate, and sodium alkylbenzene sulfonate; aliphatic soaps and fatty acids. Fatty acid metal salts such as sarcosides and rosin acid soap; these Na
A sulfate ester type anionic surfactant or a fatty acid derivative having 1, NH+, and alkanolamine ions in place of + can be used. These anionic emulsifiers have a solid content of 0.6 to 2 parts by weight per 100 parts by weight of the resulting aqueous emulsion copolymer.
．． It is used in a proportion of 5 parts by weight. If the amount is more than this, the destructive effect of the emulsifier is small and the expected aggregation of copolymer particles does not occur partially or at all, and the hydration hardening reaction of cement and gypsum is inhibited. If the amount is too small, the polymerization stability and storage stability of the aqueous copolymer emulsion will be low, and the copolymer particles will agglomerate quickly, causing problems in the stability of mixing with cement and fillers. In other words, if the amount is less than 0.6 parts by weight, the copolymer particles will aggregate and the rate of aggregation will increase, making it difficult to mix the cement or filler with the copolymer aqueous emulsion and water, making it difficult to mix the cement or filler with the copolymer aqueous emulsion. Nonuniform mixing occurs in the mortar, and the performance of the resulting cured polymer cement mortar is not constant. Furthermore, emulsion polymerization during emulsion production becomes difficult. On the other hand, if the amount exceeds 2.5 parts by weight, it will take time for the copolymer particles in the emulsion to coagulate and solidify, and depending on the constituent parts of the copolymer in the emulsion, a part of the copolymer emulsion may fall into the polymer cement mortar layer. (lower layer) 1 and separate water dispersion layer (upper layer) 2 (see Figure 2),
Anionic copolymer aqueous emulsions are not utilized effectively. A nonionic surfactant such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, or polyoxyethylated castor oil may be used together with the anionic emulsifier. It has the power to protect and stabilize the copolymer resin particles from Ca''+ and Mg'' without being affected by the effects.It is also stable and effective during the polymerization of resin emulsions, and is effective as a dispersant for fillers. However, if it is used in an amount exceeding 2%, a part of the resin emulsion cannot be agglomerated, so it is better to use as little as possible. It is preferable to blend a nonionic emulsifier during or after polymerization within the range of 1 to 8); 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and their methacrylate equivalents; esters such as acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, ethylene, acrylonitrile, methyl methacrylate, vinyl acetate, styrene, Acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid,
Maleic anhydride etc. can be used, and two of these vinyl monomers can be used.
The glass transition point of the copolymer particles of the resulting aqueous emulsion is preferably -30°C to +30'
C, and the vinyl monomer is selected so that the amount of carboxyl groups in the copolymer falls within the above range. In addition. So-called reactive emulsifiers, such as sodium vinyl sulfonate, are treated as anionic emulsifiers if they are anionic. Emulsion polymerization is carried out in the usual manner,
The concentration of resin solids in the resulting copolymer aqueous 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 this anionic copolymer aqueous emulsion used is:
Although it largely depends on the type of vinyl monolayer constituting the copolymer, in general, component (A) hydraulic cement 10
The solid content is 3 to 30 parts by weight relative to 0 parts by weight. 3
If the amount exceeds 0 parts by weight, a large amount of Ca and Mg generated from component (C), which are necessary for coagulation of the emulsion resin, will be required, and this increase in component (C) will affect the original performance of cement mortar due to the ratio to hydraulic cement. will be erased. Furthermore, no further improvement in waterproofing properties can be expected from the aqueous emulsion on the cured polymer cement mortar, and there is little merit in 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 emulsion of component (B) to be used in the cement of component (A) is largely influenced by the type of vinyl monomer constituting the copolymer of the emulsion, as described above, and generally contains acid groups, hydroxyl groups, and amide groups. Copolymers that have functional groups such as groups tend to have lower upper limit values for their usage than copolymers that do not have these functional groups. [Inorganic compounds] The inorganic compounds of component (C) include calcium and magnesium sulfates, chlorides, carbonates, hydroxides, oxides, etc. that generate Ca"+ and Mg" ions in water. can be used. Specifically, gypsum, quicklime, magnesium oxide, calcium carbonate, etc. are used. These are (B
) Enough 1 is used to break the emulsion of the ingredients. [Water] Water not only contributes to the hydraulic hardening reaction of cement, but also serves as a dispersion medium for cement and filler until the cement hardens. And water is 3 parts by weight for 100 parts by weight of cement.
It is used in an amount of 0 to 100 parts by weight, preferably 35 to 70 parts by weight. However, in the present invention, since the resin component of the emulsion is precipitated and adhered to the cement and filler, it cannot be separated even if diluted, so a large amount of water may be used, and the flow is very large. A polymer cement mortar composition with good workability is obtained. [Filler] As the filler for component (D), fine aggregates such as silica sand, extender pigments such as titanium oxide and clay, coloring pigments such as iron oxide and chromium oxide, talc, crushed stone, lightweight aggregates, and fibers are used. Bulking materials such as can be used. [Cement mortar] Cement mortar is a mixture of cement (A), filler (D), and an appropriate amount of water. Moreover, various additives (synthetic resin, water reducing agent, air entraining agent, etc.) can be used in this cement mortar as necessary. [Polymer cement mortar composition] To prepare the copolymer cement mortar, add the emulsion of the component (B) to the cement mortar of the cement of the component (A), the di acid component filler, and water, and then add the emulsion of the component (B) compound or magnesium compound. Also, add (B) to the cement mortar mixed with component (C).
) Prepare by adding an emulsion of ingredients. Construction (coating) and casting are performed at a temperature 5° C. or more lower than the glass transition point (Tg) of the copolymer particles of the emulsion to prevent fusion of aggregated copolymer particles of the emulsion. The applied or cast polymer cement mortar generates heat due to the hydraulic reaction of the cement, and if necessary, by heating it, the copolymer particles adhere to the mortar, forming a tough film or molded product. And the Tg of the emulsion copolymer
If the temperature is kept below 40°C, preferably below 20°C, a cured product of polymer cement mortar can be obtained even in winter without steam curing, but in order to quickly develop the strength of the cured product, steam curing is required. Good too. The curing time of polymer cement mortar is 1. Normally, it reaches a strength that can be carried around in about 6 hours, after which the hydraulic reaction of the cement progresses and the compressive strength improves, and it reaches almost saturated compressive strength in 7 to 30 days. After curing, a cured polymer cement mortar having sufficient compressive strength can be obtained in about one day. [Examples, etc.] The present invention will be explained in more detail below using Examples, etc.
Note that parts and percentages in the examples are based on weight unless otherwise specified. Production example of aqueous resin emulsion Example 1 Temperature controller, anchor stirrer, reflux condenser, supply container,
The following raw materials were charged into a reaction vessel equipped with a thermometer and a nitrogen inlet tube. water
200 parts 3.9 parts of a 35% aqueous solution of the sodium salt of the sulfuric acid half ester of p-nonylphenol (anionic emulsifier a) reacted with 20 moles of ethylene oxide.
After purging the inside of the reaction vessel with nitrogen gas, 10% of the feed I shown below was added, and the mixture was heated to 90°C. Feed I Water
200 parts 35% aqueous solution of the above anionic emulsifier 19 parts styrene 192 parts acrylic acid n-
Butyl 194 parts Acrylamide
14 parts Furthermore, after charging 10% of a solution of 2.5 parts of potassium persulfate in 85 parts of water (Feed ■) into the reaction vessel, the remaining Feed I in total and Feed H
90% of the feed is fed into the reaction vessel over a period of 3.5 hours, and after the feed is finished, the feed is kept at the same temperature for 2 hours to polymerize the feed (1) to form an anionic column oil aqueous with a -COOII content of 0% by weight. An emulsion (Tg+17°C) was obtained. Examples 2 to 17 The type of vinyl monomer and the type and amount of emulsifier were changed as shown in Table 1 below to obtain an aqueous emulsion of copolymer particles having the physical properties shown in the same table. Note that the nonionic emulsifier was first charged into the reaction container. Example 1 100 parts by weight of ordinary Portland cement, 3 parts by weight of standard silica sand
00 parts by weight and 150 parts by weight of water in mortar slurry,
20 parts by weight of the anionic resin aqueous emulsion obtained in Example 1 were mixed, and then 30 parts by weight of alpha gypsum was added to prepare a polymer cement mortar composition. The dispersion state of this product was as shown in FIG. 1, and there was no layer separation. The following evaluations were performed on this polymer cement mortar composition. Troweling workability: Troweling properties and uniform coating properties were investigated when the polymer cement mortar compositions were troweled at the temperatures shown in Table 1 below. Bending strength: According to JIS R-5201 (after 28 days) 40 parts by weight of water in 100 parts by weight of water-dilutable polymer cement mortar composition
Parts by weight were added, stirred and mixed for 5 minutes, and after standing for 30 minutes, the presence or absence of layer separation was examined. Good---1---Poor single layer condition shown in Figure 1---
--1--Two-layer state Examples 2 to 10 and Comparative Examples 1 to 6 shown in Figure 2 The same procedure as in Example 1 was carried out except that the composition of the mercement mortar to be rinsed was changed as shown in Table 2 below. Polymer cement mortar compositions were prepared and evaluated. The results are shown in the same table. Examples 11 to 23, Comparative Examples 7 to 12 Polymer cement mortar compositions having the following compositions were prepared in the same manner as in Example 1, except that the emulsions shown in Table 3 below were used instead of those in Example 1. ,
evaluated. Ordinary Portland cement 100 parts by weight Emulsion 20 parts by weight α gypsum
30 parts by weight Mixture of No. 5 silica sand and No. 8 silica sand (1/l) 300 parts by weight Water 35 parts by weight The results are shown in Table 3. Example 24 The formulation of Example 1 was repeated except that 20 parts of yellow iron oxide was further used as a coloring agent. In this example, the dispersion state, water dilutability, troweling workability, etc. were good. Example 25 The formulation evaluated for water dilutability in Example 23 was poured with a filter paper placed and filtered under reduced pressure using a water jet pump.The filtrate was transparent and there were no particular problems with filtration. ) was heated and cured for 3 days at 80° C. and 90% humidity to obtain a cured polymer cement mortar with a bending strength of 136 kg/d. In the case of Comparative Example 1, no matter how diluted with water, the white water of the emulsion first became a filtrate, and after only a small amount was removed, it became impossible to filter. Effect of the Invention 1 The present invention is as described above, and as is clear from Tables 2 and 3 above, the composition has improved various properties. And it can be freely diluted with water.
In addition, it is possible to provide a polymer cement molar composition in which separation of emulsion is less likely than in cement mortar.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are both cross-sectional views showing the dispersion state of the polymer cement mortar composition. Representative patent attorney, l7i1′ Sadao Kikuyō...1 [;...

Claims (2)

[Claims] (1) Hydraulic cement (A) Carboxyl group (-COOH) concentration obtained by emulsion polymerization of a vinyl monomer mixture in the presence of an anionic surfactant that forms a chelate compound with 100 parts by weight of polyvalent metal ions is 0
~0.7% by weight of anionic copolymer aqueous emulsion (B) 3 to 30 parts by weight of copolymer solids Inorganic compound that generates calcium ions or magnesium ions in water (C) 10 to 150 parts by weight Material (D) 0 to 490 parts by weight [However, the sum of component (C) and component (D) is 10 to 500 parts by weight. ] A polymer cement mortar composition characterized in that the components (A), (B), (C) and (D) are blended in the proportions described above. (2) Hydraulic cement (A) A copolymer aqueous emulsion obtained by emulsion polymerization of a vinyl monomer mixture using an anionic surfactant that forms a chelate compound with 100 parts by weight of calcium or magnesium ions. Anionic copolymer aqueous emulsion (B) in which the carboxyl group concentration in the copolymer is 0 to 0.7% by weight: 3 to 30 parts by weight of copolymer solids [however, copolymer 100% by weight] The amount of anionic surfactant to be used in terms of parts by weight 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 components (C) and (D) is 10 to 500 parts by weight Department. ] After adding the above component (C) to the polymer cement mortar composition containing the above components (A), (B) and (D), (B)
1.) A method for producing a cured polymer cement mortar product, which comprises applying or casting at a temperature 5° C. or more lower than the glass transition point of the emulsion of the component (2) to cause a hydraulic reaction.