JP2002161231A - Water-borne undercoating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-borne undercoating material composition which is an aqueous system without using a chlorinated polyolefin and having excellent adhesion to various kinds of substrates, adhesion to coatings, inks and adhesives and excellent adhesion to a single-layer elastic coating, a multilayered elastic intermediate coating and an old coated film. SOLUTION: This water-borne undercoating material composition is obtained by compounding (A) a copolymer emulsion prepared by carrying out an emulsion polymerization of a monomer mixture of (a) 2-35 wt.% of an acetoacetoxy group-containing ethylenically unsaturated monomer with (b) 65-98 wt.% of a vinylic monomer copolymerizable with the monomer (a) and having 0-50 deg.C glass transition temperature and 0.05-0.5 μm particle diameter with (B) an organic solvent having >=50 deg.C flash point. The organic solvent (B) is aliphatic dibasic acid esters and/or propylene-based glycol ethers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous undercoating material composition used for the purpose of aqueous undercoating such as a molded article or film of a plastic, a siding board for a building material, or a paint for a building exterior. Used as a primer for paints, inks and adhesives on plastic molded products and films, used as a primer for coating siding boards for construction materials, as a base treatment for base materials of architectural exterior paints, and as a sealer for old paint films. The present invention relates to an aqueous primer composition.

[0002]

2. Description of the Related Art Conventionally, plastic resins are generally crystalline and have few functional groups with high reactivity on the surface. Therefore, it is difficult to bond or coat the plastic resin base material. In order to improve this, a physical method such as acid treatment, corona discharge or plasma treatment is performed on the surface of the plastic resin. However, this alone does not provide a sufficient effect. In order to further improve the adhesion to a plastic resin, a primer is generally used in many cases. In addition, when painting siding boards for building materials by factory production, or when coating paint on the surface of base materials such as building materials, mortar, concrete, etc. at the construction site, as a base treatment material on the base material, or adhesion with the top coating paint Primer sealers are commonly used to improve performance. Compositions containing chlorinated polyolefin-based resins are widely used as these primers and undercoat sealers. As a primer, a composition containing a chlorinated polyolefin resin has excellent adhesion to a plastic resin substrate, so that paints, inks,
Used to improve the adhesiveness of the adhesive, as the undercoat sealer, a composition containing a chlorinated polyolefin-based resin is applied as an overcoat paint, a water-based glossy paint, a single-layer elastic paint, and a de-layer elastic. It is used for a wide variety of paints, such as low pigment volume concentration emulsion paints such as coating paints and solvent-based lacquer paints, because it has excellent adhesion to old coating films.

[0003] Organic solvents such as toluene and xylene, which are good solvents for chlorinated polyolefin resins, are generally used for primers and undercoat sealers containing these chlorinated polyolefin resins. For example, JP
JP-A-221512 discloses a solvent-based polyolefin-based resin composition obtained by graft polymerization of an acrylic oligomer, a polydiene, and a specific chlorinated polyolefin. Further, Japanese Patent Publication No. 2-29702 discloses an aqueous sealer obtained by emulsifying an organic solvent solution of a specific chlorinated polyolefin resin in a water medium using a surfactant.

[0004] However, the composition containing a chlorinated olefin as described above contains a large amount of an organic solvent, so that the working environment, safety for the human body, air pollution, fire and explosion hazards, which are problems today, are problematic. There are problems such as sex. Further, since the aqueous sealer is mechanically dispersed, there is a problem of storage stability of separation and sedimentation due to fusion and aggregation of particles over time.

As a method for solving the above problems, Japanese Patent Application Laid-Open No. Hei 5-209006 discloses a method in which chlorinated polyolefins and (meth) acrylic oligomers are dissolved in (meth) acrylic monomers and the presence of a catalyst. A method for producing a (meth) acryl-modified chlorinated polyolefin aqueous emulsion obtained by suspension polymerization in an aqueous medium is disclosed below. JP-A-7-300570 discloses a method in which a specific chlorinated polyolefin is dissolved in an aliphatic high-boiling organic solvent, emulsion is produced in the presence of a surfactant, and a vinyl monomer is polymerized in the emulsion. Chlorinated polyolefin-containing aqueous coating compositions are disclosed. In recent years, when environmental pollution has become even more problematic,
There are concerns about dioxin generation during incineration of chlorine compounds and soil contamination due to disposal.

Accordingly, there is a need for an aqueous primer or undercoat sealer containing no chlorine-based compound. JP-A-5-247376 discloses that in an aqueous medium, an ethylenically unsaturated carboxylic acid and a C _{1 to} C ₁₀ alkyl (meth) acrylate, a vinyl aromatic compound, a vinyl halide, a saturated vinyl carboxylate, A copolymer obtained by copolymerization of a monomer selected from the group consisting of (meth) acrylonitrile, ethylene and butadiene with another monomer is solubilized in a specific amount by adding an alkali and / or organic solvent. Aqueous primers are disclosed. In JP-A-11-222567,
Contains a vinyl-based aqueous copolymer consisting of a carbonyl-containing radical-polymerizable vinyl monomer, a carboxyl-containing radical-polymerizable vinyl monomer, a hydroxyl-containing radical-polymerizable vinyl monomer, and other radical-polymerizable vinyl monomers, and a crosslinking agent. An aqueous curable sealer is disclosed. All of them have insufficient adhesion to base materials, paints, adhesives and old coating films.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aqueous solution without using a chlorinated polyolefin, and to have an adhesive property to various substrates, an adhesive property to paints, inks, adhesives, It is an object of the present invention to provide a water-based undercoat material composition having excellent adhesion to a layer elastic paint, a re-layer elastic intermediate paint and an old paint film.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, as an aqueous base material composition, an acetoacetoxy group-containing ethylenically unsaturated monomer was used. Flash point of copolymerized copolymer composition is 50 ° C
It has been found that a compound containing the above organic solvent has excellent adhesion to various substrates and paints, and the present invention has been completed.

That is, a single monomer of the acetoacetoxy group-containing ethylenically unsaturated monomer (a) in an amount of 2 to 35% by weight and the vinyl monomer (b) copolymerizable with (a) in an amount of 65 to 98% by weight. An organic solvent having a flash point of 50 ° C. or more is added to a copolymer emulsion (A) having a glass transition temperature of 0 to 50 ° C. and a particle size of 0.05 to 0.5 μm obtained by emulsion polymerization of a polymer mixture. An aqueous undercoating material composition containing (B), and preferably, the organic solvent (B) is an aliphatic dibasic acid ester or a propylene glycol ether.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail. The acetoacetoxy group-containing ethylenically unsaturated monomer (a) used in the present invention has one or more ethylenically unsaturated double bonds and one or more acetoacetoxy groups in one molecule. The acetoacetoxy group-containing ethylenically unsaturated monomer is used for plastic-based resin base materials and siding boards for building materials produced by factories, or building materials at building sites,
It is an essential component for obtaining adhesion to base materials such as mortar and concrete, and adhesion to inks, adhesives, topcoats, and old paint films. Specific examples of the acetoacetoxy group-containing ethylenically unsaturated monomer include acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, and acetoacetoxyallyl ester. The amount used is from 2 to 35 based on the total amount of the monomers.
% By weight. Preferably, it is 3 to 30% by weight. If the amount is less than 2% by weight, the effect of adhesion is insufficient, and if it exceeds 35% by weight, the copolymerizability is poor.

The vinyl monomer (b) copolymerizable with the acetoacetoxy group-containing ethylenically unsaturated monomer (a) used in the present invention is a monomer having a radically polymerizable reactive double bond. It is particularly preferable to use a non-functional monomer and a functional group-containing monomer in combination. Representative specific examples of non-functional monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate,
tertbutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, 2- Ethylhexyl carbitol (meth) acrylate, isobonyl (meth)
(Meth) acrylic acid alkyl or cycloalkyl ester monomers such as acrylate; methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, and trimethylolpropane tripropoxy (meth) acrylate; (Meth) alkoxyalkyl ester monomers; aromatic vinyl monomers such as styrene, α-methylstyrene and vinyltoluene; and nitrile monomers such as (meth) acrylonitrile. At least one selected from these groups can be used. Preferably,
(Meth) acrylic acid alkyl ester monomers and styrene.

Representative examples of the functional group-containing monomer used in the present invention include: carboxyl group-containing monomers such as (meth) acrylic acid, maleic anhydride, fumaric acid, and itaconic acid; Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2
-Hydroxy-3-phenoxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, (poly)
Hydroxyl-containing monomers such as alkylene glycol monoacrylates, and these monomers and lactones (for example, ε-
Adduct with caprolactone, etc .; diacetone (meth) acrylamide, acrolein, formylstyrene, (meth) acrylamide pivalinaldehyde, diacetone (meth) acrylate, acetonyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate acetyl Monomers containing a carbonyl group such as acetate and vinyl alkyl ketone; other monomers having a functional group include sodium vinyl sulfonate, sodium parastyrene sulfonate, (meth) acrylamide, N-methylolacrylamide, glycidyl (meth) Acrylate and the like. At least one selected from these groups can be used. Preferably, it is (meth) acrylic acid or a hydroxyl group-containing monomer.

The amount of the vinyl monomer (b) used in the present invention is 50 to 50% based on the total amount of the monomer.
97.9% by weight, and 0.1 to 15 of the functional group-containing monomer.
% By weight. Further, it is preferable to use 0.1 to 5% by weight of (meth) acrylic acid in the functional group-containing monomer.

The glass transition temperature (hereinafter referred to as Tg) of the copolymer in the copolymer emulsion (A) of the present invention must be 0 to 50 ° C. When the Tg of the copolymer is lower than 0 ° C., the cohesive strength of the coating film is insufficient, and the adhesion to the porous substrate and the old coating film is reduced. T of copolymer
If g exceeds 50 ° C., the film-forming properties of the emulsion will decrease. In addition, the Tg of the copolymer is determined from the calculated value using the Tg value of each homopolymer described in the standard of the Japan Emulsion Industry Association, "Method of indicating the hardness of the film of the synthetic resin emulsion (107-1996)".

The particle size of the copolymer emulsion (A) of the present invention must be 0.05 to 0.5 μm. Preferably, it is 0.05 to 0.3 μm. The smaller the particle diameter, the better the wettability and permeability to the base material, but the mechanical stability tends to deteriorate. Particle size 0.05
If it is smaller than μm, the obtained emulsion has poor mechanical stability. When the particle diameter is larger than 0.5 μm, the permeability to the porous substrate decreases.

The copolymer emulsion (A) of the present invention comprises:
The monomer mixture is obtained by emulsion polymerization in an aqueous medium in the presence of an emulsifier. The emulsion polymerization method can be obtained by a usual method. The emulsifier used in the emulsion polymerization is not particularly limited, but an anionic emulsifier, a nonionic emulsifier, and a reactive emulsifier can be used. Representative specific examples include, for example, potassium oleate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate,
Sodium polyoxyethylene alkyl ether sulfate,
Sodium polyoxyethylene alkyl allyl ether sulfate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl allyl ether phosphate, polyoxyethylene alkyl phenyl ether sulfate, sodium alkyl diphenyl ether disulfonate, polyoxyethylene styrenated cresol sulfate Anionic emulsifiers such as esters; nonionics such as polyoxyethylene alkyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oxypropylene block copolymer, polyethylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester Emulsifier; polyethylene of various molecular weights (different EO addition moles) Glycol mono (meth) acrylate, polyoxyethylene alkyl phenol ether (meth) acrylate, 2- (meth) acryloyloxyethyl ammonium sulfonate, monomaleate and derivatives thereof, polyoxyethylene glycol,
Reactive emulsifiers such as (meth) acryloyl polyoxyalkylene alkyl ether phosphate esters are exemplified.
At least one selected from these groups can be used.

When the copolymer emulsion (A) of the present invention is emulsion-polymerized, the degree of polymerization is adjusted if necessary.
Chain transfer agents can be used. Examples of the chain transfer agent used include n-dodecyl mercaptan, 2-mercaptoethanol, n-butyl mercaptan, trichloromercaptan, and isopropyl alcohol.
At least one selected from these groups can be used.

As the polymerization initiator used for emulsion polymerization of the copolymer emulsion (A) of the present invention, a polymerization initiator used for ordinary emulsion polymerization can be used.
Ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, peroxides of peroxyesters,
Water-soluble polymerization initiators are preferred. Also, ferrous chloride, ferrous sulfate, sodium bisulfite, L-ascorbic acid, L
-A peroxide may be used in combination with a reducing agent such as sodium ascorbate.

The organic solvent (B) used in the present invention is used as a film-forming aid of the copolymer emulsion (A) of the present invention, and has an affinity for the copolymer emulsion (A) and an organic solvent. It is necessary to improve the evaporating property, the wettability to the plastic resin substrate and the permeability to the porous substrate. The flash point must be 50 ° C. or higher in consideration of non-dangerous substances and low odor. The organic solvent used in the present invention is not particularly limited as long as it has a flash point of 50 ° C. or higher. However, those having a good balance between the effect as a film-forming aid and the drying property are preferable. More preferred are aliphatic dibasic acid esters and / or propylene glycol ethers. Specific examples of the aliphatic dibasic acid esters include dimethyl adipate, dibutyl adipate, diisobutyl adipate, bis (2-ethylhexyl) adipate, diisodecyl adipate, bis (butyl diglycol) adipate, and bis (2-ethylhexyl). ) Azelates, dimethyl sebacate, dibutyl sebacate, bis (2-ethylhexyl) sebacate, diethyl succinate and the like. Specific examples of propylene glycol ethers include dipropylene glycol methyl ether, tripropylene glycol methyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, and tripropylene glycol n-butyl ether. And the like. At least one organic solvent selected from these groups can be used. The amount used is sufficient as long as it has the function of acting as a film-forming auxiliary and the function of wetting and penetrating into the substrate.
Preferably, the amount is 5 to 40 parts by weight based on 100 parts by weight of the resin component of the copolymer emulsion.

The aqueous primer composition of the present invention may contain, if necessary, known additives such as plasticizers, fillers, pigments, viscosity modifiers, defoamers, preservatives, dispersants, antioxidants, and ultraviolet rays. An absorber, an ultraviolet stabilizer, an antifreezing agent, a flame retardant, a flame retardant and the like can be blended within a range that does not impair the effects of the present invention.

[0021]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition,
Parts in Examples are parts by weight, and% is% by weight.

Example 1 68.5 parts of deionized water and sodium polyoxyethylene nonylphenyl ether sulfate (manufactured by Kao Corporation) were placed in a reactor equipped with a stirrer, reflux condenser, thermometer, dropping device and nitrogen inlet tube. 1 part of trade name Lebenol WZ) was charged and sufficiently purged with nitrogen. Then, the internal temperature was raised to 80 ° C., and 1 part of a 10% aqueous solution of ammonium persulfate was added. 5 parts, 26.0 parts of 2-ethylhexyl acrylate, acrylic acid 3.
5 parts, 1.5 parts of 2-hydroxyethyl methacrylate,
8.5 parts of acetoacetoxyethyl methacrylate, n-
0.85 parts of dodecyl mercaptan, sodium polyoxyethylene nonylphenyl ether sulfate (Kao Corporation)
8 parts, Deionized water 49.4
Of a monomer emulsion consisting of 1 part by weight. In parallel, a polymerization reaction is carried out for 3 hours while dropping 10 parts of an aqueous solution of ammonium persulfate dissolved at a concentration of 2%. Aging is continued for 5 hours while maintaining the internal temperature at 80 ° C. The internal temperature is cooled to room temperature, 2 parts of 25% aqueous ammonia are added, and then 17 parts of butyl diglycol acetate (manufactured by Daicel Chemical Industries, Ltd.) are added, followed by sufficient stirring. The obtained aqueous undercoat material composition has a solid content of 40.
It was 0% by weight, viscosity 610 mPa · s, pH 8.5, particle size 0.12 μm, and Tg of the copolymer was 26 ° C. There was no flash point, and the adhesion to the acrylic plate, slate plate and old coating film was good. The results are shown in Table 1.

Examples 2 and 3 In Example 2, the total amount of the organic solvent used in Example 1 was 2,
In Example 3, the organic solvent used in Example 1 was changed to diisobutyl adipate (Taoka Chemical Industry Co., Ltd.) in 2,4 trimethyl 1,3 pentanediol monoisobutyrate (trade name CS-12, manufactured by Chisso Corporation). Aqueous undercoat material composition was obtained in the same manner as in Example 1 except that 8.5 parts of dipropylene glycol n-butyl ether (manufactured by Dow Chemical Japan Co., Ltd., trade name: Dwanol DPnB) was changed to 8.5 parts. Was. The aqueous undercoat material composition obtained in Example 2 had a solid content of 40.0% by weight, a viscosity of 830 mPa · s, and a pH of 8.0.
5. The particle size is 0.12 μm, and the Tg of the copolymer is 2
6 ° C. There was no flash point, and the adhesion to the acrylic plate, slate plate and old coating film was good. The aqueous undercoat material composition obtained in Example 3 had a solid content of 40.0% by weight,
Viscosity 550 mPa · s, pH 8.5, particle size 0.12μ
m, and the Tg of the copolymer was 26 ° C. There was no flash point, the adhesion to the slate plate was good, and the adhesion between the acrylic plate and the old coating film was very good.
The results are shown in Table 1.

Example 4 In Example 4, an aqueous undercoat material composition was obtained in exactly the same manner as in Example 3 except that acrylic acid in Example 3 was changed to methacrylic acid. The obtained aqueous undercoat material composition has a solid content of 40.0%.
The viscosity was 180 mPa · s, the pH was 8.5, the particle diameter was 0.12 μm, and the Tg of the copolymer was 27 ° C. There was no flash point, the adhesion to the slate plate was good, and the adhesion between the acrylic plate and the old coating film was very good. The results are shown in Table 1.

Example 5 In Example 5, an aqueous undercoat material composition was prepared in the same manner as in Example 3, except that the vinyl monomer in Example 3 was changed to 54.5 parts of butyl acrylate and 32 parts of methyl methacrylate. Obtained. The obtained aqueous undercoat material composition had a solid content of 40.0% by weight, a viscosity of 3,800 mPa · s, a pH of 8.5, a particle size of 0.08 μm, and a Tg of the copolymer of 27 ° C. There was no flash point, the adhesion to the slate plate was good, and the adhesion between the acrylic plate and the old coating film was very good. The results are shown in Table 1.

Examples 6 and 7 In Example 6, the amount of acetoacetoxyethyl methacrylate used in Example 3 was changed to 4 parts, and the amounts of other vinyl monomers and solvents were changed as shown in Table 1. In the same manner as in Example 1, an aqueous primer material composition was obtained. In Example 7, the amount of the acetoacetoxyethyl methacrylate of Example 3 was changed to 25 parts, and the amounts of other vinyl monomers and the solvent were changed as shown in Table 1. I got something. The aqueous undercoat material composition obtained in Example 6 had a solid content of 40.0% by weight, a viscosity of 720 mPa · s, a pH of 8.5, and a particle size of 0.12 μm.
And the Tg of the copolymer was 28 ° C. There was no flash point, and the adhesion to the acrylic plate, slate plate and old coating film was good. The aqueous undercoat material composition obtained in Example 7 had a solid content of 40.0% by weight, a viscosity of 520 mPa · s,
H8.5, particle size 0.12 μm, Tg of copolymer
Was 23 ° C. There was no flash point, the adhesion to the slate plate was good, and the adhesion between the acrylic plate and the old coating film was very good. The results are shown in Table 1.

Example 8 In Example 8, the organic solvent used in Example 3 was DOA (bis (2-ethylhexyl) adipate manufactured by Taoka Chemical Industry Co., Ltd.) and Dwanol TPM (Dow Chemical Japan Co., Ltd.). Tripropylene glycol methyl ether)
An aqueous undercoat material composition was obtained in the same manner as in Example 3 except that the composition was changed to. The obtained aqueous undercoat material composition has a solid content of 4
0.0 wt%, viscosity 680 mPa · s, pH 8.5, particle size 0.12 μm, and Tg of the copolymer was 26 ° C. There was no flash point, the adhesion to the slate plate was good, and the adhesion between the acrylic plate and the old coating film was very good. The results are shown in Table 1.

Examples 9 and 10 In Examples 9 and 10, the Tg of Example 3 was measured at 43 ° C. and 5 ° C.
Thus, an aqueous undercoat material composition was obtained in the same manner as in Example 3, except that the amounts of the vinyl monomer and the organic solvent used were changed as shown in Table 1. The aqueous undercoat material composition obtained in Example 9 had a solid content of 40.0% by weight and a viscosity of 1,050 mPa ·
s, pH 8.5, particle size 0.12 μm, Tg of the copolymer was 43 ° C., no flash point, and good adhesion to acrylic plate, slate plate and old coating film. The aqueous undercoat material composition obtained in Example 10 had a solid content of 40.
0% by weight, viscosity 120 mPa · s, pH 8.5, particle size 0.12 μm, Tg of the copolymer is 5 ° C., no flash point, adhesion to acrylic plate, slate plate and old coating film It was good. The results are shown in Table 2.

Example 11 In Example 11, an aqueous primer composition was prepared in the same manner as in Example 3 except that the amount of the initially charged surfactant was adjusted so that the particle diameter of Example 3 became 0.26 μm. I got something. The obtained aqueous undercoat material composition had a solid content of 40.0% by weight, a viscosity of 80 mPa · s, a pH of 8.5, a particle diameter of 0.26 μm, and a Tg of the copolymer of 26 ° C. There is no flash point,
The adhesion to the acrylic plate, slate plate and old coating film was good. The results are shown in Table 2.

Comparative Example 1 Comparative Example 1 is an aqueous primer composition of Example 6 which does not use the acetoacetoxy group-containing ethylenically unsaturated monomer.
An aqueous primer material composition was obtained in the same manner as in Example 6. The obtained aqueous undercoat material composition had a solid content of 40.0% by weight and a viscosity of 4%.
10 mPa · s, pH 8.5, particle size 0.12 μm, and Tg of the copolymer was 28 ° C. Although there was no flash point, the adhesion to the acrylic plate, slate plate and old coating film was poor. The results are shown in Table 2.

Comparative Example 2 Comparative Example 2 is a comparative example in which the particle diameter of Example 3 was changed.
An aqueous undercoating material composition was obtained in the same manner as in Example 3 by adjusting the amount of the initially used surfactant. The obtained aqueous undercoat material composition had a particle size of 0.60 μm, which was outside the scope of the claims, and had no flash point, but had poor adhesion to an acrylic plate, a slate plate, and an old coating film. The results are shown in Table 2.

Comparative Examples 3 and 4 In Comparative Example 3, an aqueous undercoat was prepared in exactly the same manner as in Example 1 except that the organic solvent of Example 1 was changed to toluene, and that of Comparative Example 4 was changed to xylene. A material composition was obtained. The aqueous undercoating material composition obtained in Comparative Example 3 has a flash point of 38 ° C. and is a dangerous substance, and has problems in handling in a workplace and regulating the storage amount. Adhesion to the acrylic plate, slate plate and old coating film was poor. The aqueous undercoating material composition obtained in Comparative Example 4 has a flash point of 40 ° C. and becomes a dangerous substance, and has problems in handling in a work place and regulation of storage amount. The adhesion to the acrylic plate and the old coating film was good, but the adhesion to the slate plate was poor. Table 2 shows the results.

[0033]

[Table 1]

[0034]

[Table 2]

The monomers and solvents described in Tables 1 and 2 are represented by the following abbreviations. Monomer: ST: styrene (Tg: 100 ° C) MMA: methyl methacrylate (Tg: 105 ° C) BA: butyl acrylate (Tg: -52 ° C) 2-EHA: 2-ethylhexyl acrylate (Tg: -70 ° C) AAc : Acrylic acid (Tg: 106 ° C) mAAc: Methacrylic acid (Tg: 185 ° C) 2-HEMA: 2-hydroxyethyl methacrylate (Tg: 55 ° C) AAEM: Acetocetoxyethyl methacrylate (Tg: 8 ° C) Solvent: BDGA : Butyl diglycol acetate (manufactured by Daicel Chemical Industries, Ltd. (flash point: 116 ° C.) CS-12: 2,2,4 trimethyl 1,3 pentanediol monoisobutyrate (manufactured by Chisso Corporation) (flash point: 106 ° C.) DIBA: diisobutyl adipate (manufactured by Taoka Chemical Industry Co., Ltd.) (flash point: DOA: bis (2-ethylhexyl) adipate (manufactured by Taoka Chemical Industry Co., Ltd. (flash point: 205 ° C.)) DPnB: dipropylene glycol n-butyl ether (manufactured by Dow Chemical Japan Co., Ltd. DPnB) (Flash point: 106 ° C) TPM: Tripropylene glycol methyl ether (trade name: Dowanol TPM manufactured by Dow Chemical Japan Co., Ltd.) (Flash point: 122 ° C) Toluene: (Flash point: 4.4 ° C) Xylene : (Flash point: 25.6 ° C)

Test method Particle size The particle size is determined by NICOMP Model 370 (Particle Siz
ing Systems Inc.). 2. Flash point The flash point was measured with a Seta closed flash point measuring device. 3. Adhesion Adhesion is determined by applying an overcoat to a slate plate assuming the adhesion to a commercially available slate plate having a thickness of 1 mm, the adhesion to a commercially available slate plate having a thickness of 4 mm, and the old coating film. The material composition was applied. Further, a coating material was applied and the adhesion to the coating film surface was tested. Adhesion to Acrylic Plate Adhesion to the acrylic plate was adjusted by adjusting the aqueous undercoat material composition of the present invention to a solid content of 25% on the surface of the acrylic plate,
Brush and paint to 80 g / m ² . The test sample was dried at room temperature for 24 hours. Adhere cellophane tape to the coated surface and forcibly remove it and observe how it peels off. Adhesion to slate plate Adhesion to the slate plate was adjusted by adjusting the aqueous undercoat material composition of the present invention to a solid content of 25% on the surface of the slate plate,
Brush and paint to 80 g / m ² . The test sample was dried at room temperature for 24 hours. Adhere cellophane tape to the coated surface and forcibly remove it and observe how it peels off. Adhesion to the old paint film surface Adhesion to the old paint film surface is assumed to be the old paint film, and Nippon Paint Co., Ltd.
200 g / m ^{2 of} overcoat (two-component solvent system) on slate plate
The aqueous undercoating material composition of the present invention was adjusted to a solid content of 25% on a test plate which was applied so as to be dried at room temperature for 7 days.
The paint is applied so as to be 60 to 80 g / m ² . It was dried at room temperature for 3 hours to form an undercoat film. On the undercoat material,
As a paint, a low PVC emulsion paint (Nippe DAN Fresh R, manufactured by Nippon Paint Co., Ltd.) was applied to a thickness of 1 mm, dried at room temperature for 16 hours, and used as a test sample. Adhere cellophane tape to the paint surface and forcibly remove it and observe how it peels off. ◎: very good adhesion ：: good adhesion ：: slight peeling ×: whole peeling

[0037]

According to the present invention, a plastic base material is obtained by using an organic solvent having a flash point of 50 ° C. or higher for a copolymer obtained by copolymerizing an acetoacetoxy group-containing monomer.
It has excellent adhesion to building materials, old coatings and topcoats, and can be used as a primer for inks and adhesives, as a primer for building materials, or as an undercoat sealer for building exterior paints. .

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CC031 CC071 CC081 CG031 CG071 CG141 CG161 CG171 CH031 CH041 CH071 CH131 CH141 CH151 CJ131 CL001 GA02 JA25 JA57 KA06 MA08 MA10 MA13 MA14 NA12 NA27 PA07 PB05 PC08

Claims (2)

[Claims] 1. A monomer comprising from 2 to 35% by weight of an acetoacetoxy group-containing ethylenically unsaturated monomer (a) and from 65 to 98% by weight of a vinyl monomer (b) copolymerizable with (a). A glass transition temperature of 0 to 50 ° C., obtained by emulsion polymerization of a body mixture.
An aqueous undercoat material composition comprising a copolymer emulsion (A) having a particle size of 0.05 to 0.5 µm and an organic solvent (B) having a flash point of 50 ° C or higher. 2. The aqueous undercoat material composition according to claim 1, wherein the organic solvent (B) is an aliphatic dibasic acid ester and / or a propylene glycol ether.