JPH08283611A - Water base paint for marking of road surface - Google Patents

Abstract

PURPOSE: To obtain a water base paint for marking of road surface, consisting essentially of polymer particles prepared by emulsion polymerization, having a higher solid content in applicable viscosity than that of a conventional water base paint. CONSTITUTION: This water base paint for marking of road is surface is obtained by blending polymer particles having a double structure composed of an inner shell having +20 to +105 deg.C glass transition temperature and >=30 deg.C higher than that of an outer shell and not being cross-linked and the outer shell having -60 +40 deg.C glass transition temperature, or a double structure composed of an inner shell made of a three-dimensional cross-linked polymer and an outer shell having -60 to +60 deg.C glass transition temperature, in which the acid valve of the outer shell is 5-150mgKOH/g and the average particle diameter is 0.01-3μm, with a pigment. Since the polymer fine particles as the main material of the paint have both an extremely high molecular weight in comparison with a water-soluble resin used as an ordinary water base paint and a double layer structure and are excellent in film forming properties, the water base paint has improved drying properties even in a thick film and is provided with excellent film-forming performance suitable for marking of road surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road marking water-based paint. More specifically, the present invention is an emulsion paint mainly composed of polymer fine particles having a two-layer structure obtained by emulsion polymerization, which enables smooth thick film coating, and has excellent drying property and abrasion resistance. Regarding water-based paints.

[0002]

2. Description of the Related Art Conventionally, paint for road marking (JIS K 56
Solvent-based paints have been mainly used as the 1st and 2nd kind products described in 65-1992). In recent years, water-based paints containing little or no solvent have been demanded as measures for working environments and measures for preventing air pollution.
Generally, as the water-based paint, application of a water-soluble paint, a water-dispersion type (dispersion) paint, and an emulsion paint can be considered. However, since the water-soluble paint contains an organic solvent used during resin synthesis, it is difficult to obtain sufficient drying property and abrasion resistance. In addition, in a water dispersion (dispersion) paint, there is a limit to the amount of organic solvent that can be reduced, and it is difficult to obtain sufficient drying properties. For example, Japanese Patent Laid-Open No. 60-31581 discloses an acrylic resin dispersion-based water-based paint obtained by suspension polymerization using polyalkylene glycol as a stabilizer, but has a molecular weight higher than that of an emulsion paint. It is small and does not have sufficient dryness and abrasion resistance. In the case of an emulsion paint, since it is a paint containing water as a dispersion medium and containing little or no organic solvent, it is a preferable paint from the viewpoints of preventing air pollution, saving resources, and preventing odors and disasters. However, when the emulsion has a uniform structure, it is difficult to achieve both a smooth thick film formation and drying property and abrasion resistance in the relationship of the minimum film forming temperature. For example, Japanese Examined Patent Publication No. 55-33745 and Japanese Examined Patent Publication No. 6
The techniques disclosed in JP-A-3-29900, JP-A-3-157463, and JP-A-5-239380 correspond to this. Japanese Patent Publication No. 63-1350 discloses an example of an emulsion having a multilayer structure.
The glass transition temperature of the inner shell is −20 ° C. or lower, the glass transition temperature of the outer shell is + 20 ° C. or higher, and the so-called “soft / hard” structure is poor in film forming property.
Since the glass transition temperature of the inner shell, which accounts for 50% or more by weight, is low, there is a drawback that abrasion resistance is not sufficient.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a road marking water-based paint which contains little or no solvent, has good dryability in a thick film, and is excellent in abrasion resistance. It was done for the purpose.

[0004]

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that an inner shell having a high glass transition temperature or a three-dimensionally crosslinked inner shell and a low glass transition temperature are used. By using a polymer fine particle consisting of a two-layer structure with the outer shell, it was found that a smooth thick film coating is possible and a coating excellent in drying property and abrasion resistance is obtained, and the present invention is based on this finding. It came to completion. That is, the present invention provides (1) an uncrosslinked inner shell having a glass transition temperature of +20 to + 105 ° C., a glass transition temperature of −60 to + 40 ° C., and an acid value of 5 to 150 mg KO.
It has a two-layer structure with an uncrosslinked outer shell of H / g, the glass transition temperature of the inner shell is higher than the glass transition temperature of the outer shell by 30 ° C. or more, and the average particle diameter is 0.01 to 3 μm. A water-based paint for road marking, which is characterized in that polymer fine particles and a pigment are blended, and (2) an inner shell made of a three-dimensional cross-linked polymer, and a glass transition temperature in the range of -60 to + 60 ° C. And an average particle size of 0.1 with a two-layer structure with an uncrosslinked outer shell having an acid value of 5 to 150 mgKOH / g.
The present invention provides a water-based paint for road marking, which comprises polymer fine particles having a size of 0 to 1 to 3 μm and a pigment.

The aqueous coating composition of the present invention is mainly composed of polymer fine particles obtained by emulsion polymerization. Therefore, compared with the conventional water-soluble paint, the solid content in the paintable viscosity is high, that is, the amount of water contained in the paint is small, the drying property of the coating film is good, and the thick film It becomes possible to paint. The polymer fine particles, which are the main material of the water-based paint of the present invention, have an extremely high molecular weight as compared with the water-soluble resin used in a normal water-based paint, and have excellent abrasion resistance. Moreover, by having an acid value, the stability and film-forming property of the resin fine particles are excellent. Therefore, the dry coating film prepared by using the water-based paint of the present invention satisfies the requirements of smooth thick film coatability as a road marking paint, drying property and abrasion resistance. Further, the wear resistance can be further improved by making the inner shell have a high glass transition temperature or a three-dimensional crosslinked structure. The polymer fine particles used in the water-based paint of the present invention have a two-layer structure composed of an inner shell and an outer shell.
The polymer fine particles having such a bilayer structure form an inner shell, and after forming a polymer having a high glass transition temperature or a monomer giving a three-dimensionally crosslinked polymer by emulsion polymerization, further forming an outer shell. It can be obtained by emulsion polymerization by adding a monomer that gives a polymer having a low glass transition temperature. The polymer particles used in the water-based paint of the present invention have a glass transition temperature of +20 to + 105 ° C.
With an inner shell in the range of -60 to +40
It has a two-layer structure with an outer shell having an acid value of 5 to 150 mgKOH / g in the range of 0 ° C, and the glass transition temperature of the inner shell is 30 ° C or more higher than the glass transition temperature of the outer shell. 0
From a two-layer structure of polymer fine particles of 1 to 3 μm or a three-dimensionally crosslinked inner shell and an outer shell having a glass transition temperature in the range of −60 to + 60 ° C. and an acid value of 5 to 150 mgKOH / g That is, the polymer fine particles have an average particle size of 0.01 to 3 μm.

If the inner shell of the fine polymer particles is not cross-linked and its glass transition temperature is lower than + 20 ° C., the fine polymer particles are too soft and the coating film hardness is lowered, resulting in abrasion resistance. May be inferior. If the inner shell of the polymer fine particles is not crosslinked, and the glass transition temperature thereof exceeds + 105 ° C., the film-forming property may be poor, and the coating film may become brittle such as cracks. When the inner shell of the polymer fine particles is a non-crosslinked polymer, and the glass transition temperature of the outer shell of the polymer fine particles is less than -60 ° C, the coating film hardness obtained by the polymer being too soft decreases, Wear resistance may be inferior. If the inner shell of the polymer fine particles is not cross-linked, and the glass transition temperature of the outer shell of the polymer fine particles exceeds + 40 ° C, the film-forming property becomes poor and the coating film becomes brittle such as cracks. May be. When the inner shell of the polymer fine particles is a three-dimensional crosslinked polymer and the glass transition temperature of the outer shell of the polymer fine particles is less than -60 ° C, the polymer is too soft and the obtained coating film hardness decreases,
Wear resistance may be inferior. When the inner shell of the polymer fine particles is a three-dimensional crosslinked polymer and the glass transition temperature of the outer shell of the polymer fine particles exceeds + 60 ° C, the film forming property becomes poor and the coating film becomes brittle such as cracks. There is a risk. When the acid value of the outer shell of the polymer fine particles is less than 5 mgKOH / g,
The stability of the paint may become insufficient. When the acid value of the outer shell of the polymer fine particles exceeds 150 mgKOH / g, the viscosity of the coating material increases so much that it is necessary to lower the solid content, which may reduce the drying property of the coating material. In the water-based paint of the present invention, an emulsion having a uniform structure in which the inner shell of the polymer fine particles is a non-crosslinked polymer and the difference between the glass transition temperature of the inner shell and the glass transition temperature of the outer shell is less than 30 ° C. The coating film performance is close to that of a paint, and there is a possibility that a smooth thick film is formed and the drying property and abrasion resistance are poor. In the present invention, the glass transition temperatures of the inner shell and the outer shell are calculated as the sum of the contributions of the glass transition temperatures of the homopolymers of the respective copolymerization components constituting the respective shells according to the weight ratio of the respective copolymerization components. . The glass transition temperature of a homopolymer is described, for example, in Kyozo Kitaoka, “Introduction to Synthetic Resins for Paints” (Kobunshi Kogakukai, 19
1974), and J. Brandrup, E .; H. Imme
rgut, “Polymer Handbook, 2
nd Ed. "(Wiley-Interscience
e, 1975), for example, the glass transition temperature of polymethyl methacrylate is 105 ° C., the glass transition temperature of poly-n-butyl methacrylate is 20.
C., the glass transition temperature of poly-i-butyl methacrylate is reported to be 67.degree. Regarding the average particle size of the polymer fine particles used in the water-based paint of the present invention, the average particle size is set to 0.
If it is less than 01 μm, it is necessary to use a large amount of an emulsifier, which may reduce the water resistance and the adhesion of the coating film. If the average particle size exceeds 3 μm, the polymer fine particles are likely to aggregate and the stability may be deteriorated.

The polymer fine particles used in the water-based paint of the present invention can be obtained by polymerizing a monomer having one radically polymerizable unsaturated group in one molecule. Examples of such a monomer include methyl. (Meth) acrylate, ethyl (meth) acrylate, propyl (meth)
(Meth) acrylic acid such as acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate Alkyl esters of methoxyethyl (meth)
Acrylate, methoxybutyl (meth) acrylate,
Alkoxyalkyl esters of (meth) acrylic acid such as ethoxyethyl (meth) acrylate and ethoxybutyl (meth) acrylate, (meth) acrylamide,
N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-
Diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N-methylol (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N,
(Meth) acrylamides such as N-dimethylaminopropyl (meth) acrylamide, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, styrene, α-methylstyrene, vinyl Vinyl aromatics such as toluene, α such as (meth) acrylic acid,
β-ethylenically unsaturated carboxylic acids, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, pentyl vinyl ether,
Hexyl vinyl ether, octyl vinyl ether, 2
-Vinyl ethers such as ethylhexyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, methylcyclohexyl vinyl ether, butyl cyclohexyl vinyl ether, 2-chloroethyl vinyl ether, benzyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyhexyl vinyl ether, hydroxyoctyl vinyl ether, etc. In addition, vinyl acetate, vinyl chloride, acrylonitrile, allyl ethers and the like can be mentioned. The alkyl group in these monomers may be linear or branched.

In order to obtain polymer fine particles to be used in the water-based paint of the present invention, the above-mentioned monomers may be appropriately selected and used by polymerizing one kind alone or by copolymerizing two or more kinds. For example, for the synthesis of the inner shell, methyl methacrylate, n-butyl acrylate, i-butyl methacrylate and the like can be preferably used. Further, for the synthesis of the outer shell, methyl methacrylate, n-butyl acrylate and the like can be preferably used. However, in order to make the outer shell have an acid value, when synthesizing the outer shell,
Copolymerize a monomer having a carboxyl group. Examples of such a monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, sorbic acid, maleic acid, fumaric acid, and maleic anhydride. Among these, acrylic acid and Methacrylic acid can be used particularly preferably. In order to make the inner shell of the polymer fine particles used in the water-based coating composition of the present invention three-dimensionally crosslinked, a monomer having two or more polymerizable unsaturated bonds is copolymerized during the synthesis of the inner shell. Examples of such a monomer include divinyl ether,
Examples thereof include diallyl ether, allyl (meth) acrylate, diallyl phthalate, ethylene glycol di (meth) acrylate and divinylbenzene.

An emulsifier is used in the emulsion polymerization for obtaining the polymer fine particles used in the aqueous coating material of the present invention. As the emulsifier used in the emulsion polymerization, anionic emulsifiers, anionic reactive emulsifiers, nonionic emulsifiers, nonionic reactive emulsifiers, cationic emulsifiers, cationic reactive emulsifiers, etc. generally known for emulsion polymerization are used. Can be used. As the anionic emulsifier, for example,
Eleminor ES series [Product name, Sanyo Chemical Industry Co., Ltd.
[Made] is commercially available. As the anionic reactive emulsifier, for example, Eleminol JS-2 [trade name, manufactured by Sanyo Chemical Industry Co., Ltd.] is commercially available. As the nonionic emulsifier, for example, Nonion NS series [trade name, manufactured by NOF CORPORATION] is commercially available. Examples of the nonionic reactive emulsifier include Aqualon RN series [trade name,
Manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] is commercially available. In emulsion polymerization, as long as it has good polymerization stability, it can be used without limitation to the anionic, nonionic, and cationic emulsifiers exemplified, and a reaction having a polymerizable unsaturated group such as an allyl group. As long as the emulsifying agent is used, any of the anionic, nonionic, and cationic reactive emulsifiers can be widely used without being limited to those exemplified as the representative examples. The nonionic (reactive) emulsifier can be used by mixing with an anionic (reactive) emulsifier or a cationic (reactive) emulsifier in an arbitrary ratio, and the mixing ratio is appropriately determined depending on desired characteristics. You can choose. The amount of the emulsifier used is 0.1 to 100 parts by weight based on 100 parts by weight of the total amount of the monomers forming the polymer fine particles, whether they are used alone or as a mixture.
Amounts of 20 parts by weight, preferably 0.5 to 10 parts by weight are suitable.

As the polymerization initiator used for emulsion polymerization, organic peroxides such as benzoyl peroxide, t-butyl peroxide, cumene hydroperoxide, azobiscyanovaleric acid, azobisisobutyronitrile, azobis (2,
Organic azo compounds such as 4-dimethyl) valeronitrile and azobis (2-amidinopropane) hydrochloride, inorganic water-soluble radical polymerization initiators such as ammonium persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide, redox initiators Is appropriate. The amount of the polymerization initiator used is obvious in the technical field, and generally, the optimum required amount is in the range of 0.1 to 2 parts by weight based on 100 parts by weight of the total amount of the monomers forming the polymer fine particles. The emulsion polymerization of the above monomers can be carried out by an emulsion polymerization method which is a method known per se for producing a copolymer. The monomer can be polymerized in water by continuing the reaction in the presence of an emulsifier and a polymerization initiator at a reaction temperature of usually 40 to 100 ° C, preferably 60 to 90 ° C for about 1 to 20 hours. The aqueous dispersion of polymer particles obtained by emulsion polymerization contains about 10 to 60% by weight of resin solids, based on the total weight. Furthermore, the average particle size of the polymer fine particles in the aqueous dispersion is in the range of 0.01 to 3 μm. The average particle size can be adjusted by adjusting the type and amount of the emulsifier used, and polymer fine particles having an average particle size within a desired range can be easily obtained.

The obtained polymer fine particles are prepared by adding an aqueous dispersion to monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine,
Monoisopropylamine, diisopropylamine, diethylenetriamine, triethylenetetramine, monoethanolamine, diethylethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, morpholine, methylmorpholine, piperazine, ammonia, sodium hydroxide, hydroxide It is preferably used in the state of an aqueous dispersion after being neutralized with a base such as potassium or lithium hydroxide. A pigment is added to the water-based paint of the present invention. As the pigment, a coloring pigment and an extender pigment are used for the purpose of imparting a color tone and a hiding power to the coating film and also serving as a filler for thickening the film to enhance the drying property. Usually, the coloring pigment is added in an amount of 15 to 30% by weight, and the extender pigment is added in an amount of 20 to 50% by weight. As the coloring pigment, titanium oxide is used in the case of white paint, and yellow iron oxide or the like is used in the case of yellow paint depending on the color tone. As extender pigments, barium sulfate, aluminum oxide, magnesium silicate, silicon dioxide, calcium carbonate, magnesium carbonate, talc,
Kaolin, mica, etc. are appropriately selected according to the desired characteristics, and they are used alone or in combination of two or more. The water-based coating composition of the present invention may optionally contain one or more additives such as a surface conditioner, an anti-repellent agent, an antifoaming agent and the like. Further, the solvent or dispersion medium in the water-based paint of the present invention is mainly water, but an organic solvent can be added if necessary. The type of organic solvent is not particularly limited, for example, methanol,
Ethanol, isopropanol, n-propanol, n
-Alcohols such as butanol, methyl cellosolve,
Cellosolves such as ethyl cellosolve and butyl cellosolve, glycols such as ethylene glycol, propylene glycol and diethylene glycol can be used. The composition and amount are arbitrary, but for example, water 10
Up to 30 parts by weight per 0 parts by weight can be used.

[0012]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Production Example 1 197 parts by weight of deionized water, ammonium salt of sulfated polyoxyethylene nonylphenyl ether [Eleminol ES-12, Sanyo Kasei Co., Ltd., was placed in a flask equipped with a stirrer, a thermometer, a condenser and a temperature controller. )] 3.4 parts by weight and 0.3 parts by weight of sodium tetraborate were added, and the temperature was raised to 85 ° C. with stirring. Of this emulsion, 300 parts by weight of methyl methacrylate, 80 parts by weight of n-butyl acrylate, 20 parts by weight of i-butyl methacrylate, 4.6 parts by weight of emulsifier [Eleminol ES-12] and 180 parts by weight of deionized water 29.2 parts by weight (5
%) And 1.3 parts by weight of ammonium persulfate dissolved in 8 parts by weight of deionized water were added. After stirring for a further 15 minutes, 555.4 parts by weight (95% by weight) of the remaining emulsion was added dropwise over 1 hour. After the dropping was completed, 13 parts by weight of deionized water was added, and the temperature was kept at 85 ° C. for another hour to prepare an aqueous dispersion of the inner shell of polymer fine particles. 45 parts by weight of methyl methacrylate, n
-Emulsion consisting of 65 parts by weight of butyl acrylate, 10 parts by weight of methacrylic acid, 2 parts by weight of emulsifier [Eleminol ES-12] and 80 parts by weight of deionized water, 0.5 parts by weight of ammonium persulfate and 37 parts by weight of deionized water. The aqueous solutions dissolved in the respective parts were simultaneously added dropwise over 30 minutes. The temperature was kept at 85 ° C. for 1 hour to prepare an aqueous dispersion of polymer fine particles having a bilayer structure. The acid value of the outer shell is 54 mgKOH / g
(Calculated value). This aqueous dispersion was heated to 95 ° C., 9 parts by weight of ammonia water (25% by weight) was added dropwise over 20 minutes, and an aqueous formaldehyde solution (37% by weight) was added to prevent the growth of bacteria in the final product. An antimicrobial solution prepared from 9 parts by weight and 3 parts by weight of deionized water was added. Then keep it at 95 ° C for 1 hour, then cool to room temperature,
It was filtered and taken out. The obtained aqueous dispersion of polymer fine particles was a stable aqueous dispersion of polymer fine particles (E-1) having a solid content of 50.3% by weight and an average particle diameter of 0.12 μm. The glass transition temperature of the inner shell of the polymer fine particles was 54 ° C, and the glass transition temperature of the outer shell thereof was 2 ° C (both calculated values). Production Examples 2 to 5 In the same manner as in Production Example 1, aqueous dispersions E-2 to 5 of polymer fine particles were prepared according to the composition shown in Table 1. Reference Example 1 In exactly the same manner as in Production Example 1, an aqueous dispersion of the inner shell of polymer fine particles was prepared. To this aqueous dispersion, 15 parts by weight of methyl methacrylate, 70 parts by weight of n-butyl acrylate, 35 parts by weight of methacrylic acid, an emulsifier [Eleminol ES-1
2] An emulsion consisting of 2 parts by weight and 80 parts by weight of deionized water, 0.5 parts by weight of ammonium persulfate and 3 parts of deionized water.
When an aqueous solution dissolved in 7 parts by weight was added dropwise at the same time, the viscosity rapidly increased. Therefore, deionized water was added until stirring became possible, and the monomer emulsion and the ammonium persulfate aqueous solution were further added dropwise. 1 hour after the addition of the monomer emulsion and ammonium persulfate aqueous solution was completed,
The temperature was kept at 85 ° C. to obtain an aqueous dispersion of polymer fine particles having a two-layer structure. The acid value of the outer shell is 190 mgKOH / g (calculated value). This aqueous dispersion was neutralized with aqueous ammonia (25% by weight) and an aqueous formaldehyde solution was added in the same manner as in Production Example 1. The resulting aqueous dispersion of polymer particles was a stable aqueous dispersion (G-1) of polymer particles having a solid content of 30.2% by weight and an average particle size of 0.15 μm. The glass transition temperature of the inner shell of the polymer fine particles is 54 ° C., and the glass transition temperature of the outer shell thereof is 6 ° C. (all calculated values). Reference Examples 2 to 3 In the same manner as in Production Example 1, aqueous dispersions G-2 to 3 of polymer fine particles were prepared according to the composition shown in Table 1. Reference Example 4 In a flask equipped with a stirrer, a thermometer, a condenser and a temperature control device, 197 parts by weight of deionized water, ammonium salt of sulfated polyoxyethylene nonylphenyl ether [Ereminol ES-12, Sanyo Kasei Co., Ltd. )] 3.4 parts by weight and 0.3 parts by weight of sodium tetraborate were added, and the temperature was raised to 85 ° C. with stirring. To this, 200 parts by weight of methyl methacrylate, 275 n-butyl acrylate
By weight, 45 parts by weight of methacrylic acid, 6.6 parts by weight of emulsifier [Eleminol ES-12] and 260 parts by weight of deionized water, and 1.8 parts by weight of ammonium persulfate to 45 parts by weight of deionized water. The dissolved aqueous solutions were simultaneously added dropwise over 2 hours. The temperature was kept at 85 ° C. for 1 hour to prepare an aqueous dispersion of polymer particles. The acid value of the polymer fine particles is 56 (calculated value). This aqueous dispersion,
In the same manner as in Production Example 1, neutralization with aqueous ammonia (25% by weight) and addition of an aqueous formaldehyde solution were performed. The aqueous dispersion of polymer particles obtained had a solid content of 50.
It was a stable aqueous dispersion (G-4) of polymer fine particles having 3% by weight and an average particle size of 0.14 μm. The glass transition temperature of the polymer particles is 4 ° C. (calculated value).

[0013]

[Table 1]

[0014]

[Table 2]

[Note] ES-12: Ammonium salt of sulfated polyoxyethylene nonylphenyl ether [Ereminol ES-12,
Sanyo Chemical Industry Co., Ltd.]. JS-2: Anionic reactive emulsifier [Eleminol JS
-2, manufactured by Sanyo Chemical Industry Co., Ltd.]. MMA: methyl methacrylate. BA: n-butyl acrylate. IBMA: i-butyl methacrylate. MAA: methacrylic acid. Production Examples 6 to 10 In the same manner as in Production Example 1, aqueous dispersions E-6 to 10 of polymer fine particles were prepared according to the composition shown in Table 2. Reference Example 5 In exactly the same manner as in Production Example 6, an aqueous dispersion of the inner shell of polymer fine particles was prepared. 35 parts by weight of methyl methacrylate, 50 parts by weight of n-butyl acrylate, 35 parts by weight of methacrylic acid, an emulsifier [Eleminol ES-1
2] An emulsion consisting of 2 parts by weight and 80 parts by weight of deionized water, 0.5 parts by weight of ammonium persulfate and 3 parts of deionized water.
When an aqueous solution dissolved in 7 parts by weight was added dropwise at the same time, the viscosity rapidly increased. Therefore, deionized water was added until stirring became possible, and the monomer emulsion and the ammonium persulfate aqueous solution were further added dropwise. 1 hour after the addition of the monomer emulsion and ammonium persulfate aqueous solution was completed,
The temperature was kept at 85 ° C. to obtain an aqueous dispersion of polymer fine particles having a two-layer structure. The acid value of the outer shell is 190 mgKOH / g (calculated value). This aqueous dispersion was neutralized with aqueous ammonia (25% by weight) and an aqueous formaldehyde solution was added in the same manner as in Production Example 6. The resulting aqueous dispersion of polymer particles was a stable aqueous dispersion (G-5) of polymer particles having a solid content of 30.1% by weight and an average particle size of 0.85 μm. The glass transition temperature of the outer shell of the polymer fine particles is 34 ° C. (calculated value). Reference Example 6 In the same manner as in Production Example 6, an aqueous dispersion G-6 of polymer fine particles was prepared according to the composition shown in Table 1.

[0016]

[Table 3]

[0017]

[Table 4]

[Note] ES-12: Ammonium salt of sulfated polyoxyethylene nonylphenyl ether [Ereminol ES-12,
Sanyo Chemical Industry Co., Ltd.]. JS-2: Anionic reactive emulsifier [Eleminol JS
-2, manufactured by Sanyo Chemical Industry Co., Ltd.]. MMA: methyl methacrylate. BA: n-butyl acrylate. IBMA: i-butyl methacrylate. AMA: Allyl methacrylate. DVB: divinylbenzene. MAA: methacrylic acid. Example 1 A water-based road marking paint was prepared using an aqueous dispersion E-1 of polymer particles. In a container equipped with a stirrer, 100 parts by weight of an aqueous dispersion of polymer fine particles (E-1), 5 parts by weight of ethylene glycol, 10 parts by weight of butyl cellosolve, 5 parts by weight of methanol, SN deformer 468 [trade name, San Nopco Ltd. ) Defoaming agent] 2 parts by weight were charged, and then 35 parts by weight of titanium oxide and 140 parts by weight of calcium carbonate were gradually added with stirring. At a rotation speed of 1,000 rpm,
Stirring was continued until the particle size was 70 μm or less, and deionized water was added so that the paint viscosity was 70 to 100 KU / 20 ° C. Examples 2 to 10 In the same manner as in Example 1, water-based markings for road marking were prepared according to the composition shown in Table 3.

[0019]

[Table 5]

[0020]

[Table 6]

[Note] Antifoaming agent: SN deformer 468 manufactured by San Nopco Ltd. Organic solvent: ethylene glycol / butyl cellosolve / methanol = 5/10/5 (weight ratio). Comparative Examples 1 to 6 In the same manner as in Example 1, water-based road marking paints were prepared with the compounding compositions shown in Table 4.

[0022]

[Table 7]

[0023]

[Table 8]

[Note] Antifoaming agent: SN deformer 468 manufactured by San Nopco Ltd. Organic solvent: ethylene glycol / butyl cellosolve / methanol = 5/10/5 (weight ratio). Regarding the obtained water-based paint for road marking, JIS K 56
The evaluation was carried out in accordance with the corresponding items of 1 type and 2 types of 65.
That is, as the material of the test plate, asphalt felt having a size defined by JIS is used for the items related to appearance and bleeding, and tire adhesion, hiding rate, luminous reflectance (diffuse reflectance), water resistance, alkali resistance For the items relating to the adhesion of glass beads, a glass plate having a size also specified by JIS was used. In addition, in the item of wear resistance, JI
A steel plate having a size defined by S was used. For coating, each test item should have a film thickness specified by JIS.
A B-type film applicator was selected and used. Also,
All the coating films were dried at room temperature. Using the test plate thus coated, a performance test was conducted by the following method. (1) Appearance of coating film: According to JIS K 5665 6.8. (No visual abnormality on the coating film) (2) Tire adhesion: According to JIS K 5665 6.9. (The paint should not adhere to the tire 10 minutes after application.) (3) Concealment rate: According to JIS K 5665 6.10.
(0.97 or more) (4) Luminous reflectance: According to JIS K 5665 6.11. (80 or more) (5) Bleed: According to JIS K 5665 6.12.
(The luminous reflectance of the coated surface on the asphalt felt is 70 or more, and the luminous reflectance ratio is 0.90 or more.) (6) Abrasion resistance: According to JIS K 5665 6.13. (500 mg or less per 100 rotations) (7) Water resistance: According to JIS K 5665 6.16.
(No abnormality after immersion for 24 hours) (8) Alkali resistance: According to JIS K 5665 6.17. (No abnormality after immersion for 18 hours) (9) Glass bead fixing rate: JIS K 5665 6.2
According to 0. (90% or more) The obtained results are shown in Tables 5 and 6. However,
A circle indicates a pass, and a cross indicates a failure.

[0025]

[Table 9]

[0026]

[Table 10]

As shown in Table 5, from the water-based paints for road marking of Examples 1 to 10, coating films having good performance were obtained. The coating material of Comparative Example 1 is an example of polymer fine particles having a high acid value of the outer shell, but because of its low solid content, JIS K 5
665 3. Density 1.3g / cm ³ specified in the quality item
The above standards are not met. In addition, tire adhesion, water resistance and alkali resistance are insufficient. The coating material of Comparative Example 2 is an example of polymer fine particles having a high glass transition temperature of the outer shell, but the coating film becomes rigid and brittle, and wear resistance is poor. In addition, the adhesion to the article to be coated is reduced and the water resistance is also reduced. The coating material of Comparative Example 3 is an example of polymer fine particles in which the glass transition temperatures of the inner shell and the outer shell are within the range of the present invention, but the difference in glass transition temperature between the inner shell and the outer shell is small. Poor dryness and wear resistance. The paint of Comparative Example 4 is an example of polymer fine particles having a uniform structure, but the tire adhesion due to drying property is poor, and the paint of the example having the polymer fine particles has a two-layer structure. In comparison, the wear resistance is also inferior. The coating material of Comparative Example 5 is an example of polymer fine particles having a high acid value of the outer shell, but since the solid content thereof is low, JIS K 5
665 3. Density 1.3g / cm ³ specified in the quality item
The above standards are not met. In addition, tire adhesion, water resistance and alkali resistance are insufficient. The coating material of Comparative Example 6 is an example of polymer fine particles having a high glass transition temperature of the outer shell, but the coating film becomes rigid and brittle, and wear resistance is poor. In addition, the adhesion to the article to be coated is reduced and the water resistance is also reduced.

[0028]

The road marking water-based paint of the present invention is mainly composed of polymer fine particles obtained by emulsion polymerization.
Compared with conventional water-soluble paints, the solid content in the paintable viscosity is high. Further, the polymer fine particles, which is the main material of the coating material of the present invention, has an extremely high molecular weight as compared with a water-soluble resin used for a normal aqueous coating material, has a two-layer structure, and is excellent in film-forming property, It has good dryness in thick film and has excellent coating performance suitable for road marking.

Claims (2)

[Claims] 1. An uncrosslinked inner shell having a glass transition temperature in the range of +20 to + 105 ° C. and a glass transition temperature of −.
It has an acid value of 5 to 150 mgKOH in the range of 60 to + 40 ° C.
/ G having a two-layer structure with an uncrosslinked outer shell, the glass transition temperature of the inner shell is higher than the glass transition temperature of the outer shell by 30 ° C. or more, and the average particle size is 0.01 to 3 μm. A water-based paint for road marking, which is characterized in that it contains a mixture of fine particles and a pigment. 2. An inner shell made of a three-dimensional crosslinked polymer, having a glass transition temperature in the range of −60 to + 60 ° C., and an acid value of 5 to 5.
A road marking aqueous solution, characterized in that it comprises a pigment and polymer fine particles having an average particle size of 0.01 to 3 μm and having a two-layer structure with an uncrosslinked outer shell of 150 mgKOH / g. paint.