JPS631350B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel color paving composition that can be applied at room temperature and is composed of a multilayer structure polymer emulsion obtained by multistage emulsion polymerization of vinyl monomers, aggregates, and pigments. Conventionally, room-temperature painting color pavement compositions have been proposed in which various additives and colorants are blended with a vinyl copolymer obtained by conventional emulsion polymerization (Japanese Patent Application Laid-open No. 49-97039, 52-45411). However, since these are made of a sticky resin composition to improve adhesion to the substrate (concrete, asphalt, mortar, etc.), they inevitably have poor stain resistance and are difficult to use with painting tools such as rubber rake, sponge roll, etc. It is very difficult for painting tools to come apart due to excessive adhesion to the paint, and since cement is used to increase hardness, (1) clumping is likely to occur after curing, and (2) if drying progresses due to lack of moisture. (3) Workability is difficult due to restrictions on pot life; (4) In addition, color development is poor due to elution of inorganic salts due to moisture absorption, and self-fading significantly impairs aesthetic appearance. Furthermore, since a large amount of organic solvent is used to improve workability, there are various drawbacks such as toxicity and strong odor. As a result of intensive studies to improve these drawbacks, the present inventors found that a multilayer structure polymer emulsion obtained by multi-step emulsion polymerization of vinyl monomers is different from a conventional polymer emulsion having the same monomer composition. The inventors discovered that the adhesive properties, stain resistance, workability, color development, etc. of these materials are extremely superior compared to other materials, and have thus arrived at the present invention. That is, in the present invention, when vinyl monomers are emulsion polymerized in two or more stages, the monomers are added at each stage and the emulsion polymerization is carried out in the presence of the aqueous emulsion obtained up to the previous stage. The polymer formed by emulsion polymerization in the stage or first stage and any subsequent intermediate stage has a glass transition temperature of -20°C or lower and the proportion thereof is 50 to 97 parts by weight, and the final stage or the final stage The polymer formed by emulsion polymerization at any intermediate stage preceding it has a glass transition temperature of +20°C or higher and the proportion thereof is 50 to 3 parts by weight. A colored paving composition is provided comprising a combined emulsion, an aggregate and a pigment. It is presumed that the multistage polymer emulsion used in the present invention has a multilayer structure formed by the polymers. In other words, the polymer formed in the first stage becomes the core layer, on which the polymer formed in the intermediate stage (in the case of three or more stages) overlaps, and the polymer formed in the final stage forms the outer shell. It is presumed that they form a layer. At this time, it is not clear whether an orderly multilayer structure will be formed, but at least the polymer formed in the previous step should be bonded to the polymer formed in the next step, or the polymer formed in the next step should be tightly associated. . Therefore, in producing the multistage polymer emulsion used in the present invention, an emulsifier is produced when the vinyl monomer in the first stage, which is to form the core layer, is emulsion polymerized in the presence of a peroxide catalyst. It is necessary to carry out the polymerization under conditions such that the vinyl monomer is completely adsorbed on the polymer emulsion particles and no new emulsion particles are generated even if the vinyl monomer to form the outer layer is added. Additional polymerization initiators may thus be added between each stage, but no additional emulsifier is used, so as not to form essentially new additional and different particles. The thus obtained polymer emulsion of the present invention contains 50 to 97 parts by weight of a vinyl polymer having a glass transition temperature of -20°C or lower as the core layer and 50 to 97 parts by weight of a vinyl polymer having a glass transition temperature of +20°C or higher as the outer shell layer. This is a multilayered polymer emulsion that can be formed into a film at room temperature and contains 3 parts by weight. The average particle size of emulsions is small, generally in the range of 0.02 to 1 micron. In the case of a polymer emulsion with three or more layers, the polymer with a glass transition temperature of -20°C or less that forms the intermediate layer following the core layer should be added to the core layer in an amount of 50 to 97 parts by weight, and the intermediate layer following the outer shell layer. The glass transition temperature that forms the layer is +
The polymer having a temperature of 20° C. or higher is included in the outer shell layer in an amount of 50 to 3 parts by weight. Vinyl monomers forming the polymer of the present invention include (1) (meth)acrylic esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, (2) ) Acrylic monomers such as methacrylic acid, acrylic acid, and glycidyl methacrylate are suitable, as well as other monomers that can be copolymerized with the acrylic monomers mentioned in (1) and (2) above, such as styrene. , acrylonitrile,
Vinyl acetate may also be used. The polymer emulsion particles used in the composition of the present invention must have a multilayer structure consisting of at least two layers, and the core layer of the polymer must have a glass transition point of -20
℃ or below, the glass transition temperature of the polymer forming the outer layer must be below +20℃. The glass transition point of the polymer forming the outer layer of the emulsion, which is the polymer component of the composition of the present invention, is +20°C.
If it is less than 20%, the resulting color pavement composition will have poor stain resistance and workability during painting, and will not exhibit sufficient water resistance. Furthermore, even when the glass transition point of the polymer forming the outer layer of the emulsion is +20°C or higher, if the glass transition point of the polymer forming the core layer exceeds -20°C, the color paving composition of the present invention This is not preferable because the film forming property of the coating film at room temperature is lost. In the present invention, the core layer of the emulsion is made of a polymer with a glass transition point of -20°C or less, and the outer layer is made of a polymer with a glass transition point of 20°C or more, so that the coating film of the color pavement composition has high elasticity. It is possible to give high elasticity and extensibility. When forming the polymer emulsion of the present invention, the proportion of the vinyl polymer with a glass transition temperature of -20°C or less that forms the core layer (and the intermediate layer following this) is 50
~97 parts by weight is required. That is, if it is less than 50 parts by weight, the adhesion to the substrate is poor, and if it is more than 97 parts by weight, the stain resistance is poor. Typical monomers that form polymers with a glass transition temperature of -20°C or lower include ethyl acrylate, butyl acrylate, and acrylic acid 2.
Examples include acrylic monomers such as ethylhexyl. On the other hand, the outer shell layer (and the intermediate layer that precedes it)
It is necessary that the proportion of the vinyl polymer having a glass transition temperature of 20° C. or higher to form the composition be 50 to 3 parts by weight. That is, if the amount is less than 3 parts by weight, the stain resistance will be poor;
Moreover, if the amount exceeds 50 parts by weight, the adhesiveness will be poor. Typical monomers that form polymers with a glass transition temperature of +20°C or higher include acrylic monomers such as methyl methacrylate, methacrylic acid, acrylic acid, and glycidyl methacrylate; acrylonitrile; vinyl acetate; Examples include styrene. In order to form a film from the above polymer emulsion at room temperature, a film forming aid may be used as necessary, such as diethylene glycol n-butyl ether acetate, ethylene glycol n-butyl ether acetate,
Texanol or the like may be added in an amount of 5 to 25 parts by weight per 100 parts by weight of the emulsion. Room temperature film formation means film formation at a temperature of 2° C. or higher. In producing the multistage polymer emulsion of the present invention, a polymer having a glass transition temperature between -20°C and +20°C may be included as necessary in an intermediate stage. It is necessary that the ratio is set to a level that does not impede the intended performance of the emulsion of the present invention. Examples of the aggregate to be incorporated into the composition of the present invention include silica sand, sand, rubber powder, plastic beads, earth and sand, and the like. The particle size of aggregate is generally 10~
The range is 200 meters. Further, the pigments blended into the composition of the present invention are inorganic and organic pigments. Examples of inorganic pigments include iron oxide pigments and chromium oxide pigments.
Examples of organic compounds include phthalocyanine green and phthalocyanine blue, and any compounds conventionally used in color paving compositions can be used. In preparing the pavement composition of the present invention, aggregate 5
~70 parts by weight of the above multistage polymer emulsion
It is preferable to mix it in a proportion of 95 to 30 parts by weight (assuming a concentration of about 45% by weight). (Total 100 parts by weight). That is, if the emulsion is less than 30 parts by weight, the adhesion to the substrate (concrete, asphalt, mortar, etc.) decreases, while if the emulsion exceeds 95 parts by weight, the relative amount of aggregate decreases, resulting in a significant decrease in surface hardness. Both are unfavorable because they are impractical. It is necessary to add an appropriate amount of pigment depending on the degree of coloring, but it is generally added in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the emulsion.
There is no problem in adding aggregate and pigment to a suitable blend of two or more types of multi-stage polymer emulsions. When applying the color pavement composition of the present invention, only the multi-stage polymer emulsion that can form a film at room temperature of the coating composition of the present invention is directly applied to the base using a coating tool such as a rubber rake, rubber roller, trowel, spray gun, etc. After drying, the pavement composition of the present invention may be applied. Alternatively, the paving composition of the present invention may be applied after previously applying a suitable primer such as urethane resin or epoxy resin to the base. The color paving composition of the present invention may also contain fillers such as calcium carbonate, clay, talc, stone powder, etc., and small amounts of polymeric protective colloids as thickeners (e.g., carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene oxide, polyethylene oxide, etc.). The emulsion may be thickened by adding about 1 part of sodium acrylate, etc. to 100 parts by weight of the emulsion. Note that an organic solvent such as xylene, butyl acetate, etc. may be added for the purpose of preventing sedimentation of the aggregate. The characteristics of the pavement composition of the present invention are listed below. (1) Compared to copolymers with the same glass transition temperature, the multilayer polymer of the present invention has a higher ratio of polymers with a higher glass transition temperature, so it has less stickiness, stain resistance, and ease of handling during painting. In addition, the film of the polymer of the present invention has elasticity, so it can be used for park sidewalks, tennis courts, shopping street sidewalks, poolsides, building rooftops, balconies, parking lots, exercise facilities, cycling. road,
When painted on sidewalks in housing complexes, it is soft and gives a good walking feel. (2) It has the characteristics of (1) and has good adhesion to the base. (3) Excellent drying properties due to the small average particle size of the polymer. When aggregate and pigment are mixed, the paving composition does not become whitish, and the color of the paving composition after drying is very clear. It is full of beauty. Therefore, the so-called coloring property is very excellent. (4) Emulsion has excellent water resistance because the polymer outer shell layer is a polymer with a high glass transition temperature. (5) Excellent weather resistance. Incidentally, there is no problem in adding additives such as antifoaming agents, dispersants, preservatives, rust preventives, surfactants, etc. to the pavement composition of the present invention, if necessary. The following is a description of production examples and examples. Note that the number of parts indicates parts by weight, and the percentage indicates weight %. Production example 1 4.4 parts of ethyl acrylate, 1.2 parts of sodium dodecylbenzenesulfonate, 0.1 part of potassium persulfate, water
55 parts were subjected to emulsion polymerization in a conventional manner to obtain a first-stage aqueous polymer emulsion. Ethyl acrylate was added to the resulting emulsion (glass transition temperature -22°C).
24.3 parts of 2-ethylhexyl acrylate and 10.4 parts of 2-ethylhexyl acrylate were dropwise emulsion polymerized at about 75°C for 2 hours to obtain a second stage aqueous polymer emulsion (glass transition temperature -45°C). Furthermore, by dropwise emulsion polymerization of 4.4 parts of methyl methacrylate and 0.2 parts of methacrylic acid at approximately 75°C for 30 minutes, the third stage aqueous polymer (glass transition temperature
Finally, a multistage acrylic polymer emulsion was obtained which was formed into a film at 2°C or higher with a solid content of about 45%, a viscosity of 1300 cps, and an average particle size of 0.08 microns. Production example 2 4.4 parts of ethyl acrylate, 1.2 parts of sodium dodecylbenzenesulfonate, 0.1 part of potassium persulfate, water
54.26 parts were subjected to emulsion polymerization in a conventional manner to obtain a first stage aqueous polymer emulsion. 26.4 parts of ethyl acrylate was added dropwise to the obtained emulsion (glass transition temperature -22°C) for emulsion polymerization at about 75°C for 2 hours to obtain a second stage aqueous polymer emulsion (glass transition temperature -22°C). Furthermore, methyl methacrylate
13.2 parts of methacrylic acid and 0.44 parts of methacrylic acid are dropwise emulsion polymerized at approximately 75°C for 30 minutes to produce a third-stage aqueous polymer (glass transition temperature + 104°C), with a final solid content of approximately 45% and a viscosity of A multistage acrylic polymer emulsion was obtained which was formed at 2° C. or higher at 1000 cps and an average particle size of 0.05 microns. Example 1 (1) Multi-stage acrylic polymer emulsion of Production Example-1 100 parts (2) Nonionic surfactant (polyoxyethylene nonyl phenyl ether) 0.5 part (3) Dispersant (sodium tripolyphosphate) 1.0 part (4) Antifoaming agent (Nobuco NXZ manufactured by San Nobuco Co., Ltd.) 0.2 parts (5) Silica sand No. 7 140 parts (6) Pigment (chromium oxide green) 5 parts (7) Thickener (hydroxyethyl cellulose)
0.2 parts Each of the components (1) to (7) above was blended in the above proportions to prepare a color pavement composition. The color pavement composition of the above formulation was applied to the asphalt and concrete surfaces to a thickness of about 1 mm using a rubber rake. Example 2 (1) 50 parts of the multi-stage acrylic polymer emulsion of Production Example-1 (2) 50 parts of the multi-stage acrylic polymer emulsion of Production Example-2 (3) Nonionic surfactant (polyoxyethylene nonyl phenyl Ether) 0.5 parts (4) Texanol 2.5 parts (5) Dispersant (sodium tripolyphosphate) 0.5 parts (6) Antifoaming agent (Nobuco NXZ manufactured by San Nobuco Co., Ltd.) 0.2 parts (7) Silica sand No. 7 70 parts (8) Silica sand 8 No. 70 parts (9) Pigment (Iron Oxide Red) 5 parts (10) Thickener (Hydroxyethylcellulose)
0.2 parts Each of the components (1) to (10) above were blended in the above proportions to prepare a color pavement composition. The color pavement composition having the above formulation was applied to the asphalt and concrete surfaces using a rake to a thickness of about 1 mm. Comparative Example 1 Acrylic copolymer emulsion (high viscosity
1000 cps, concentration 45%) was used in place of the multistage acrylic polymer emulsion of Example-1, and coating was carried out in exactly the same manner as in Example-1, with other blending conditions and coating conditions. Evaluations of the above Examples and Comparative Examples are shown in Table-1. Table 1 shows that the color pavement composition of the present invention is particularly superior in stain resistance, non-stickiness, adhesive strength, water whitening resistance, weather resistance, and workability compared to conventional type compositions. Recognize.

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Claims (1)

[Claims] 1 Vinyl polymer 50 with a glass transition temperature of -20°C or less as the core layer or the core layer and the intermediate layer following it
-97 parts by weight of a multilayered polymer emulsion that can be formed into a film at room temperature and comprises 50 to 3 parts by weight of a vinyl polymer having a glass transition temperature of +20°C or higher as an outer shell layer or an intermediate layer preceding the outer shell layer. A colored pavement composition comprising aggregate and pigment.