JP2002265850A - Thermally curable aqueous coating composition for wall paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermally curable aqueous coating composition for wall paper having excellent storage stability and giving, excellent solvent resistance and stain resistance to an obtained film and to provide a method for wall paper production using the coating composition. SOLUTION: This thermally curable aqueous coating composition for wall paper is characterized by comprising (A) 40-90 pts.wt. of a carboxyl group- containing acrylic resin having 200-780 acid value, (B) 5-40 pts.wt. of a water-soluble or water-dispersible epoxy resin having 100-300 epoxy equivalent and (C) 5-40 pts.wt. of at least one kind of a polyol selected from a polyvinyl alcohol and a polyglycerol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wallpaper for paper or plastic film such as polyvinyl chloride, which exhibits excellent water resistance and stain resistance and has good storage stability of paint. The present invention relates to a thermosetting aqueous coating composition and a method for producing wallpaper using the coating composition.

[0002]

2. Description of the Related Art Prevention and prevention of adhesion of dirt and the like to paper or paper made of plastic films such as polyvinyl chloride used by sticking to indoor walls, closets, furniture and the like. Clear paint is often applied to the outermost surface of the contaminants so that they can be easily wiped off. In the case of mass production of these wallpapers, the paint is applied to the material for the wallpaper by a roll coater or the like, and is baked at an ambient temperature of 180 to 210 ° C. for a short time within 50 seconds.

In recent years, there has been a strong demand for conversion from a solvent-based paint to a water-based paint in order to reduce the volatilization of an organic solvent during drying, even in wallpaper coatings, due to increasing interest in environmental pollution problems. But in water-based paint,
It is not easy to satisfy the severe stain resistance required for this application by baking for such a short time, and especially if the stain resistance is improved by increasing the cross-linking property of the coating film, the storage stability of the paint is improved. There is a problem that the performance is greatly reduced.

As a method for improving the stain resistance, a method using a polysiloxane composite polymer emulsion or a polyorganosiloxane emulsion is disclosed in JP-A-8-15.
It is disclosed in 1550 gazette and the like. These methods are
The incorporation of the silicone component into the base resin attempts to lower the polarity of the resulting coating as a whole, but poses problems of lower adhesion to the material and higher cost.

[0005] Various methods have been studied to improve the stain resistance by adding a silicone-based additive, but various problems occur in terms of paint operability such as residual bubbles at the time of coating and cissing.

The present invention is intended to solve the above-mentioned problems, and to provide a thermosetting aqueous coating composition for wallpaper having excellent storage stability of the coating and excellent solvent resistance and stain resistance of the obtained coating film. And a method for producing a wallpaper using the coating composition.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a high acid value carboxyl group-containing acrylic resin, a water-soluble or water-dispersible epoxy resin and a specific polyol By combining and curing, it has been found that the storage stability of the paint is good, the solvent resistance of the coating film obtained by baking for a short time, and a good thermosetting aqueous coating composition with good stain resistance can be obtained. The invention has been completed.

That is, the present invention relates to (A) an acid value of 200 to 7
Carboxyl group-containing acrylic resin 40 to 80
90 parts by weight, (B) 5 to 40 parts by weight of a water-soluble or water-dispersible epoxy resin having an epoxy equivalent of 100 to 300, and (C) 5 to 40 parts by weight of at least one polyol selected from polyvinyl alcohol and polyglycerin. A thermosetting aqueous coating composition for wallpaper characterized by containing
And a method for producing wallpaper using the coating composition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The thermosetting aqueous coating composition for wallpaper of the present invention essentially comprises a high acid value carboxyl group-containing acrylic resin (A), a water-soluble or water-dispersible epoxy resin (B) and a polyol (C). Contains as an ingredient.

Carboxyl group-containing acrylic resin (A) The carboxyl group-containing acrylic resin as the component (A) of the present invention is a homopolymer of a carboxyl group-containing polymerizable unsaturated monomer or a carboxyl group-containing polymerizable unsaturated monomer. A copolymer with a polymerizable unsaturated monomer other than a monomer having an acid value of 200 to 780, preferably 400 to 780, from the viewpoint of curability and storage stability of the coating material. And
Those having a number average molecular weight in the range of 1,000 to 150,000, preferably 8,000 to 50,000 are suitable.

The carboxyl group-containing polymerizable unsaturated monomer includes, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid and the like, among which acrylic acid and methacrylic acid are preferred. .

The polymerizable unsaturated monomers other than the carboxyl group-containing polymerizable unsaturated monomer constituting the copolymer include:
For example, (meth) acrylic esters; vinyl ethers and aryl ethers; olefinic compounds and diene compounds; aromatic vinyl monomers; alicyclic polymerizable unsaturated monomers; nitrogen-containing unsaturated monomers; Unsaturated monomers;
Examples thereof include a phosphoric acid group-containing unsaturated monomer.

Here, examples of (meth) acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate and te acrylate.
rt-butyl, hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, stearyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, N-butyl methacrylate, isobutyl methacrylate, methacrylic acid
tert-butyl, hexyl methacrylate, methacrylic acid 2
-C1-C24 of acrylic acid or methacrylic acid such as ethylhexyl, octyl methacrylate, decyl methacrylate, lauryl methacrylate, stearyl methacrylate, etc.
Alkyl esters of methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate,
Examples thereof include alkoxyalkyl esters of acrylic acid or methacrylic acid having 2 to 18 carbon atoms, such as methoxyethyl methacrylate, ethoxybutyl acrylate, and ethoxybutyl methacrylate.

Examples of vinyl ethers and allyl ethers include linear alkyl vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether, tert-butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether and octyl vinyl ether; cyclopentyl vinyl ether Cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; aryl vinyl ethers such as phenyl vinyl ether and tolyl vinyl ether; aralkyl vinyl ethers such as benzyl vinyl ether and phenethyl vinyl ether; allyl ethers such as allyl glycidyl ether and allyl ethyl ether.

Examples of the olefinic compound and the diene compound include ethylene, propylene, butylene, vinyl chloride, butadiene, isoprene, chloroprene and the like.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, phenyl (meth) acrylate, phenylethyl (meth) acrylate, phenylpropyl (meth) acrylate, benzyl (meth) acrylate, and phenoxyethyl ( (Meth) acrylate and the like.

Examples of the alicyclic polymerizable unsaturated monomer include cyclohexyl (meth) acrylate, 4-methanolcyclohexylmethyl acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate and the like.

Examples of the nitrogen-containing unsaturated monomer include, for example,
N, N-dimethylaminoethyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
Nitrogen-containing alkyl (meth) acrylates such as Nt-butylaminoethyl (meth) acrylate; acrylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) Polymerizable amides such as acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide; 2-vinylpyridine, 1-vinyl-2-pyrrolidone, 4-vinylpyridine and the like Aromatic nitrogen-containing monomers; polymerizable nitriles such as acrylonitrile and methacrylonitrile; and allylamine.

Examples of the hydroxyl group-containing unsaturated monomer include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Examples of the monomer include 2-methacryloyloxyethyl acid phosphate and orthophosphoric acid,
Examples thereof include those obtained by adding an equimolar amount of an epoxy group-containing unsaturated polymer such as glycidyl (meth) acrylate to an acidic phosphate ester. Here, examples of the acid phosphate include methyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, and phenyl acid phosphate.

These unsaturated monomers can be used alone or in combination of two or more. In the present invention, “(meth) acrylate” means acrylate or methacrylate.

As a copolymerization method, a general polymerization method of a vinyl monomer can be used, but a solvent type radical polymerization method in an organic solvent is most suitable in consideration of versatility and cost. That is, in the presence of a polymerization initiator such as azobisisobutyronitrile and benzoyl peroxide in an organic solvent, a copolymerization reaction is usually carried out at a temperature in the range of about 60 to 170 ° C. to easily form the desired polymer. Obtainable.

The carboxyl group-containing acrylic resin (A) can be used without being neutralized. If necessary, a part of the carboxyl groups in the acrylic resin (A) may be neutralized with a neutralizing agent. Good. From the viewpoint of curability and storage stability of the paint, the neutralization amount is suitably within 50%, preferably within 30% of the carboxyl groups in the acrylic resin (A).

Examples of the alkali used as a neutralizing agent include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide and barium hydroxide; ammonia; ethylamine; Primary monoamines such as propylamine, butylamine, benzylamine, monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol; diethylamine, diethanolamine, di-n- or di-iso-propanolamine, N -Secondary monoamines such as methylethanolamine and N-ethylethanolamine; dimethylethanolamine, trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine and dimethylaminoethanol. Tertiary monoamines; diethylenetriamine, hydroxyethylaminoethylamine,
Polyamines such as ethylaminoethylamine and methylaminopropylamine can be mentioned, but organic amine-based ones are preferred.

Water-soluble or water-dispersible epoxy resin (B) The water-soluble or water-dispersible epoxy resin as the component (B) of the present invention is a resin containing an epoxy group for reacting with the carboxyl group-containing acrylic resin. It is suitable that the epoxy equivalent is in the range of 100 to 300, preferably 110 to 200 from the viewpoint of curability and the like. Examples of such an epoxy resin include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol-diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-
Hexanediol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, diglycerin tetraglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, spiroglycol diglycidyl ether, 2,6-diglycidylphenyl ether Sorbitol polyglycidyl ether, diglycidyl phthalate, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and the like. These can be used alone or in combination of two or more.

Among these, glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether and sorbitol Polyglycidyl ether is suitable in terms of curability, storage stability and the like.

Polyol (C) The polyol which is the component (C) of the present invention is selected from polyglycerin and polyvinyl alcohol, and partially contributes to the reaction and has a large effect on the stability of the paint.

As polyglycerin and polyvinyl alcohol, commercially available ones can be used without any particular limitation.
The weight average molecular weight is suitably in the range of 500 to 50,000, preferably 550 to 25,000.

The coating composition of the present invention contains a carboxyl group-containing acrylic resin (A), an epoxy resin (B) and a polyol (C). Group-containing acrylic resin (A): 40 to 90 parts by weight, preferably 50 to 80 parts by weight Epoxy resin (B): 5 to 40 parts by weight, preferably 10
To 30 parts by weight Polyol (C): 5 to 40 parts by weight, preferably 10 to 10 parts by weight
A range of 30 parts by weight is suitable.

The coating composition of the present invention comprises the above (A) and (B)
And (C) as essential components, and if necessary, conventionally known resins, curing agents, silicone-based antifouling agents, leveling agents, lubricants, coloring agents, light stabilizers, and adjustment of coating workability. A small amount of an organic solvent or the like can be blended.

As the silicone-based antifouling agent, a reactive silicone compound can be suitably used from the viewpoint of the durability of the antifouling effect, and it has no reactivity with the reactive silicone compound. Combined use with a silicone compound also has a large stain prevention effect. The reactive silicone compound refers to an acrylic resin (A) or an epoxy resin (B) at a molecular terminal and / or a side chain of dimethylpolysiloxane in which a part of a methyl group may be substituted with hydrogen and / or a phenyl group. ) and those with a structure having at least one and a group that is cured upon baking and drying one or more polyols (C). Specific examples include, for example, a reactive silicone oil and a silicone-grafted acrylic resin synthesized by copolymerization of a silicone macromonomer with a monomer component containing an acrylic monomer having a reactive group. As the reactive group,
For example, an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenol group and the like can be mentioned. Among them, an epoxy group and a carboxyl group are preferable.

The reactive silicone compound is added in an amount of 0.1 to 10 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the total solid content of the acrylic resin (A), the epoxy resin (B) and the polyol (C). Is within the range of 1 to 5 parts by weight from the viewpoint of the effect of preventing contamination and the storage stability of the paint.

Examples of the organic solvent include ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, methanol, ethanol, isopropanol, n-butanol, sec-butanol, and the like. Water-soluble or hydrophilic solvents such as alcohol solvents such as isobutanol and ethers such as n-butyl ether, dioxane, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether are preferred.

The material to which the coating composition of the present invention is applied may be any material which is usually used as wallpaper, and examples thereof include papers and plastics such as vinyl chloride.

The method for applying and drying the coating composition of the present invention is not particularly limited, and a coating machine such as a roll coater, a curtain flow coater, a blade coater, or an air spray can be used. When the coating is baked at a temperature of 150 ° C. or more, preferably 180 to 210 ° C. in a furnace for a short time of 50 seconds or less, the effect of the present coating material is most exhibited, but it takes a long time as long as the material does not deteriorate. It is also possible to perform baking. The dry film thickness is usually preferably about 5 to 15 μm.

[0035]

The present invention will now be described more specifically with reference to examples and comparative examples. Hereinafter, "part" and "%"
Are based on weight.

Synthesis Example 1 of Aqueous Acrylic Resin Synthesis Example 1 140 parts of propylene glycol monomethyl ether was charged into a reactor equipped with a stirrer, a temperature controller, and a reflux tube, heated to 110 ° C., and a mixture having the following monomer composition was added for 3 hours. It dripped over. 2-hydroxyethyl acrylate 30 parts Acrylic acid 70 parts Azobisisobutyronitrile 4.5 parts After dropping, the mixture is kept warm for 1 hour, 0.9 parts of azobisisobutyronitrile and propylene glycol monomethyl ether 1
0 part was added dropwise over 1 hour, and then aged for 1 hour to obtain an acrylic resin solution C having a solid content of 40%. The acid value of the obtained resin was 545 mgKOH / g, and the number average molecular weight was 12,000.

Synthesis Examples 2 and 3 Acrylic resin solutions D and E were obtained in the same manner as in Production Example 1 except that the composition was as shown in Table 1. The properties of each resin were as shown in Table 1. Note that Synthesis Example 3
The acrylic resin solution E is for a comparative example.

[0038]

[Table 1]

Production Examples of Aqueous Coating Compositions Examples 1 to 8 and Comparative Examples 1 to 5 Each aqueous coating composition was prepared according to the composition shown in Table 2 below. Table 2 shows the pot life of each of the obtained aqueous coating compositions.

Preparation of Test Coated Paper Each of the above paints was applied to a thin paper for wallpaper so as to have a dry film thickness of 7 to 8 μm with a bar coater, baked at 180 ° C. for 20 seconds, and then heated at 80 to 100 ° C. For 24 hours to prepare a coated paper for testing.

The obtained coated test paper was tested according to the following test method. The test results are shown in Table 2 below.

Test method : Solvent resistance: At room temperature of 20 ° C., methyl ethyl ketone was dropped on the surface of a test piece, covered with a watch glass for 6 hours, allowed to stand for 24 hours, and visually observed for the state of the coating film according to the following criteria. evaluated. ：: no change is observed on the coated surface, Δ: gloss is observed on the coated surface, ×: whitening or swelling of the coated film is observed.

Magic stain resistance: At room temperature of 20 ° C., a black magic ink (Uchida Yoko Co., Ltd.) was applied, and after standing for 6 hours, the state of the repelling of the magic ink was evaluated, and then applied with a gauze impregnated with ethanol. The magic ink was wiped off, and the mark of the magic ink was visually evaluated according to the following criteria. ：: Magic is repelled, no trace of magic ink is left by wiping ethanol. △: Magic is not repelled, but no trace of magic ink is left by wiping ethanol. Remains.

Pot life: The state of the paint after storage at 30 ° C. for 24 hours was evaluated according to the following criteria. ：: almost no increase in viscosity; Δ: large increase in viscosity but fluidity; ×: gel of the paint.

[0045]

[Table 2]

[0046]

The coating composition of the present invention is an aqueous coating composition having a low organic solvent content, and is sufficiently cured even under short-time baking conditions to form a film having excellent solvent resistance, stain resistance and the like. It is very suitable especially as a thermosetting water-based paint for wallpaper because of its good storage stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09D 171/00 C09D 171/00 D21H 27/20 D21H 27/20 A F-term (Reference) 4F100 AK21A AK25A AK52A AK53A AL05A BA02 BA07 CC01A DG10B EH46 GB08 JB05A JB07 JL06 YY00A 4J038 CE022 CG001 CG031 DB002 DB032 DF012 DL032 GA03 GA06 GA07 GA09 KA06 MA08 MA14 NA04 NA05 NA26 PA19 PB05 PC08 PC10 4L055 AG64 AG37 AG86 AG37 AG86 AG37 AG86

Claims (7)

[Claims] (A) 40 to 90 parts by weight of a carboxyl group-containing acrylic resin having an acid value in the range of 200 to 780;
It is characterized by containing 5 to 40 parts by weight of a water-soluble or water-dispersible epoxy resin having an epoxy equivalent of 100 to 300 and (C) 5 to 40 parts by weight of at least one polyol selected from polyvinyl alcohol and polyglycerin. Thermosetting aqueous coating composition for wallpaper. 2. The thermosetting aqueous coating composition for wallpaper according to claim 1, wherein the carboxyl group-containing acrylic resin (A) has a number average molecular weight in the range of 1,000 to 150,000. 3. The thermosetting aqueous coating composition for wallpaper according to claim 1, wherein the carboxyl group-containing acrylic resin (A) is polyacrylic acid. 4. The wallpaper according to claim 1, wherein at least 50% of the carboxyl groups in the carboxyl group-containing acrylic resin (A) are neutralized with a neutralizing agent such as an amine. Thermosetting aqueous coating composition for use. 5. The epoxy resin (B) is glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl. The thermosetting aqueous coating composition for wallpaper according to any one of claims 1 to 4, which is at least one selected from ether and sorbitol polyglycidyl ether. 6. The thermosetting aqueous coating composition for wallpaper according to any one of claims 1 to 5, further comprising a reactive silicone compound. 7. A method for applying the thermosetting aqueous coating composition for wallpaper according to any one of claims 1 to 6 to a material for wallpaper and baking for 5 to 50 seconds at an ambient temperature of 150 ° C. or more for a short time. A method for producing a wallpaper, comprising: