JP2003041132A - Aqueous cross-linkable type resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous cross-linkable type resin composition suitable as a coating in which a film thereof is capable of maintaining water repellency over a long period even when used in the outdoors. SOLUTION: This aqueous cross-linkable type resin composition consists essentially of a hydrophilic polymer having maleimide groups, silicone groups and acidic groups or its salt and a hydrophobic polymer. The hydrophilic polymer is a copolymer of maleimide (meth)acrylate, a silicone compound having a radically polymerizable group and an acidic unsaturated compound having a carboxy group or a sulfone group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous crosslinkable resin composition, which is used as a coating agent, a curing finish agent for fibers, a water repellent agent, a sealing agent, a binder, an adhesive agent and an adhesive agent. It can be used for various purposes, and since it provides a film that maintains its water repellency outdoors for a long period of time, it is particularly suitable for use as an outdoor paint and can be used in these technical fields.

[0002]

2. Description of the Related Art The inventors of the present invention have previously studied a film-forming emulsion used for paints, coating agents, etc., and have identified an ethylenically unsaturated monomer having a maleimide group as a constituent monomer. We found that the film formed from the copolymer had excellent weather resistance and was effective as a coating material, and filed a patent application (Japanese Patent Application No. 11-344).
275, Japanese Patent Application No. 11-362080).

As mentioned in the specification of the above application,
The film or coating film obtained from those specific copolymers,
Fluorine resin consisting of fluoroolefin-vinyl ether copolymer, which is a polymer known to have excellent weather resistance, and the film gloss of the film obtained from acrylic silicone resin are insufficient, and the film and substrate It was a solution to the problem that the adhesiveness with is not at a satisfactory level.

On the other hand, in applications such as paints, attempts have been made to make the paints water-based in response to recent environmental problems and demands for improvement of working environment. Performances such as stain resistance, water resistance and weather resistance are required, but they are insufficient in all respects such as water resistance and weather resistance as compared with solvent-based coating agents.

The present inventors have adapted to environmental problems and
As a result of diligent study on a coating agent having the same performance as the solvent-based coating agent, even in an aqueous dispersion such as an emulsion, the ethylenically unsaturated monomer having a maleimide group and a specific radically polymerizable surfactant are copolymerized. Do (Japanese Patent Application 2
000-270766), or copolymerizing an ethylenically unsaturated monomer having a maleimide group and an ethylenically unsaturated monomer having a cycloalkyl group (Japanese Patent Application No.
0-270767), it was found that a curable emulsion excellent in water resistance and stain resistance derived from the crosslinking of maleimide groups by sunlight can be obtained.

On the other hand, a copolymer having a silicone unit is useful as a coating agent having water repellency, and in the presence of an aqueous graft polymer composed of a silicone macromonomer and an ethylenically unsaturated carboxylic acid salt, (meth) A water-repellent silicone-containing acrylic emulsion prepared by copolymerizing an acrylic ester has been proposed (Japanese Patent Laid-Open No. 9-21).
7296). However, when the composition was used outdoors, it was not possible to maintain the water repellency for a long period of time because the silicone component to which the hydrophilic component was gradually added flows out from the coating film due to rain or the like.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made diligent studies in order to find an aqueous crosslinkable resin composition whose coating film can maintain water repellency for a long period of time even when used outdoors. Was done.

[0008]

In order to solve the above-mentioned problems, the inventors of the present invention provide a silicone component with a component that is cross-linked by sunlight, so that the silicone component flows out of the coating film due to rain or the like. The present invention has been completed as a result of intensive studies based on the idea that it can be prevented. Less than,
The present invention will be described in detail. In the present specification, acrylate and / or methacrylate are referred to as (meth) acrylate, acrylic acid and / or methacrylic acid are referred to as (meth) acrylic acid, and acryloyl group and / or methacryloyl group are referred to as (meth) acryloyl group. Express.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION <Hydrophilic Polymer> In the composition of the present invention, a hydrophilic polymer having a maleimide group, a silicone group and an acidic group or a salt thereof (hereinafter, simply referred to as “hydrophilic polymer”). ) Is an essential ingredient. The hydrophilic polymer is
Due to the constituent silicone, water repellency is imparted to the resulting coating film.

In the present invention, the hydrophilic polymer is a polymer which is dissolved in an aqueous medium or swells in an aqueous medium, or has a property of being easily dispersed in an aqueous medium without the combined use of a surfactant or an emulsifier. It means a polymer.

There are various maleimide groups in the hydrophilic polymer, and those represented by the following formula (1) are preferable.

[0012]

[Chemical 2]

However, in the formula (1), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group, or each of them becomes one to form a carbocycle. Represents a group to be formed.

Examples of the aryl group include a phenyl group.
be able to. As a group that together form a carbocycle
Is saturated or unsaturated carbonization forming a 5- or 6-membered ring
A hydrogen group is preferred, and specifically, a group -CH₂CH₂CH₂
-, Group -CH = CHCH₂-, Group -CH₂CH₂CH₂CH
₂-, Group -CH₂CH = CHCH ₂-And the group -CH = CH
CH = CH- and the like.

As R ¹ and R ² , one is a hydrogen atom, the other is an alkyl group having 4 or less carbon atoms, both R ¹ and R ² are alkyl groups having 4 or less carbon atoms, and each is Together, a saturated hydrocarbon group forming a carbocycle is preferable in that the polymer can be easily produced, the solubility and the storage stability are excellent, and the water resistance of the crosslinked coating film of the obtained composition is excellent. Among these, a saturated hydrocarbon group in which each one forms a carbocycle is more preferable, and a group —CH ₂ CH ₂ CH ₂ CH ₂ — is particularly preferable.

Specific examples of the maleimide group are represented by the following formulas (2) to
It is shown in equation (7). Among these, the maleimide group represented by the formula (2) or the formula (3) is preferable in terms of excellent solubility and storage stability.

[0017]

[Chemical 3]

[0018]

[Chemical 4]

[0019]

[Chemical 5]

[0020]

[Chemical 6]

[0021]

[Chemical 7]

[0022]

[Chemical 8]

There are various silicone groups in the hydrophilic polymer, and examples thereof include polydimethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane and polydiphenylsiloxane.

Examples of the acidic group include a carboxyl group, a sulfone group and a phosphoric acid group, and a carboxyl group is preferable.

As the hydrophilic polymer, those produced by various methods can be used, and examples thereof include the following 1) and 2). 1) Compound having maleimide group and ethylenically unsaturated group (hereinafter referred to as maleimide unsaturated compound), silicone compound having radically polymerizable group, and compound having acidic group and ethylenically unsaturated group (hereinafter referred to as acidic unsaturated compound) Called). 2) In the presence of a silicone compound having a mercapto group,
Radical copolymerization of maleimide type unsaturated compound and acidic type unsaturated compound, and block-introduced silicone at the terminal of the copolymer by utilizing chain transfer during polymerization. Among these, those obtained by the method 1) above are preferable because they are easy to produce.

The maleimide unsaturated compound is preferably a (meth) acrylate having a maleimide group [hereinafter referred to as maleimide (meth) acrylate], and can be produced by the methods described in the following documents and patents.・ Kato Kiyo et al., Journal of Organic Synthetic Chemistry 30 (10), 89
7, (1972) -Javier de Abajo et al., Polymer, vol33.
(5), (1992) -JP-A-56-53119, JP-A-1-242569.
issue

A preferred example of maleimide (meth) acrylate is shown in formula (8).

[0028]

[Chemical 9]

However, in the formula (8), R ¹ and R ² have the same meanings as described above. R ³ represents a linear or branched alkylene group having 1 to 6 carbon atoms, R ⁴ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 6.

In the above formula (8), n is preferably 1 or 2, and more preferably 1, because the copolymer obtained is excellent in crosslinkability. R ¹ and R ² each have an independent carbon number of 4 because of their excellent polymerizability or copolymerizability with the ethylenically unsaturated group-containing monomer.
The following alkyl groups, or groups in which each of them is taken together to form a carbocycle are preferable.

Further, the maleimide (meth) acrylate is easily produced, the yield is excellent, and the resulting copolymer has excellent water resistance, and each of them forms a carbocycle. A group is preferable, and a group -C is more preferable.
H ₂ CH ₂ CH ₂ - or a group _{-CH 2 CH 2 CH 2 CH 2} - is - are preferred, particularly preferably a group _{-CH 2 CH 2 CH 2 CH 2} .

R ³ is an alkylene group having 1 to 6 carbon atoms, and preferable examples thereof include an ethylene group and a propylene group.

Preferred examples of the maleimide (meth) acrylate include compounds represented by the following formulas (9) and (10).

[0034]

[Chemical 10]

However, in the formula (9), R ⁴ and R ⁵ are a hydrogen atom or a methyl group. n is an integer of 1-6.

[0036]

[Chemical 11]

However, in the formula (10), R ⁴ and R ⁵ are hydrogen atoms or methyl groups, and R ⁶ and R ⁷ are alkyl groups having 4 or less carbon atoms. n is an integer of 1-6.

There are various kinds of silicone compounds having a radical polymerizable group, and a silene macromonomer having a (meth) acrylic group as a radical polymerizable group bonded to one end of a silicone molecule of an organopolysiloxane is preferable. A preferable molecular weight is 500 to 200,000 in terms of polystyrene equivalent number average molecular weight by gel permeation chromatography. When the number average molecular weight of the silicone macromonomer is less than 500, it is difficult for the properties derived from silicone, that is, the properties such as lubricity to be exhibited. On the other hand, when it exceeds 200,000, the polymerizability of the silicone macromonomer is poor and unreacted silicone macromonomer is likely to remain. Other reactive silicones that can be a component of the polymer include amino group-containing silicones, mercapto group-containing silicones, epoxy group-containing silicones, carboxyl group-containing silicones, hydroxyl group-containing silicones and hydrosilyl group-containing silicones. A radical-polymerizable silicone having a radical-polymerizable group at any position in its molecular chain, such as a vinyl group-containing silicone, a (meth) acryloyl group-containing silicone or a styryl group-containing silicone, is also used in the same manner as the silicone macromonomer. it can. Examples of silicones include polydimethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, and the like.

Examples of the acidic group in the acidic unsaturated compound include a carboxyl group, a sulfone group and a phosphoric acid group.

The acidic unsaturated compound having a carboxyl group is a dimer or more which is a Michael addition reaction product of an unsaturated carboxylic acid such as (meth) acrylic acid, crotonic acid, cinnamic acid, (meth) acrylic acid. Oligomer of ω-
Examples thereof include carboxyl group-containing (meth) acrylates such as carboxypolycaprolactone mono (meth) acrylate, phthalic acid monohydroxyethyl (meth) acrylate, and succinic acid monohydroxyethyl (meth) acrylate.

Examples of the acidic unsaturated compound having a sulfone group include (meth) acrylamidodimethylpropanesulfonic acid and styrenesulfonic acid.

The hydrophilic polymer may be used as a constituent monomer, if necessary, for example, styrene, α-methylstyrene,
Monomers such as (meth) acrylonitrile, vinyl acetate and (meth) acrylate can be copolymerized. Specific examples of the (meth) acrylate include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, Alicyclic alkyl (meth) acrylates such as cyclohexyl (meth) acrylate, substituted aryl (meth) acrylates such as benzyl (meth) acrylate, alkoxy such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate. Examples thereof include (meth) acrylate, isobornyl (meth) acrylate, and alkoxysilyl group-containing (meth) acrylate.

In the present invention, it is preferable to use the alicyclic alkyl (meth) acrylate in applications where chemical resistance is required. In this case, the preferable copolymerization ratio is 0 to 80% by weight based on all the monomers.

As a method for producing a hydrophilic polymer, since a monomer having a silicone is difficult to polymerize by general emulsion polymerization, solution polymerization or microsuspension polymerization is preferable, and a point of copolymerizability of a silicone macromonomer is preferable. Therefore, solution polymerization is particularly preferable. In the case of synthesizing by radical polymerization by the solution polymerization method, it can be obtained by dissolving the raw material monomer to be used in an organic solvent, adding a thermal radical polymerization initiator, and stirring with heating. Further, if necessary, a chain transfer agent can be used to control the molecular weight of the polymer.

Examples of the thermal polymerization initiator used include peroxides and azo compounds which generate radical species by heat. Examples of the peroxide include benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide and the like. Examples of azo compounds include azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile.

The organic solvent used is benzene, toluene, ethyl acetate, methanol, dimethylformamide,
Examples include isopropanol and methyl ethyl ketone. From the viewpoint of dispersibility in an aqueous medium and distillative removal property of an organic solvent, a water-soluble low-boiling solvent such as methanol, isopropanol and methyl ethyl ketone is preferable.

Examples of the chain transfer agent include dodecyl mercaptan, xanthate disulfide, diazothioether, 2-propanol and the like.

The ratio of maleimide groups in the hydrophilic polymer is preferably 0.04 to 4 mmol / g, more preferably 0.2 to 3 mmol / g.
If this ratio is less than 0.04 mmol / g, chemical resistance may be insufficient, or curing or crosslinking (hereinafter simply referred to as “curing”) may be insufficient, resulting in insufficient hardness. On the other hand, if it exceeds 4 mmol / g, when a thick film is cured, the cured film may proceed only on the surface, resulting in poor adhesion.

The hydrophilic polymer preferably has a weight average molecular weight of 1,000 to 500,000, more preferably 2,000 to 100,000, and if this value is less than 1,000. May have insufficient strength, water resistance, weather resistance and adhesion of the cured film,
On the other hand, when this value exceeds 500,000, the viscosity becomes too high, and the workability may be deteriorated and the coatability may be deteriorated.

In the present invention, the number average molecular weight means the molecular weight measured by gel permeation chromatography (hereinafter abbreviated as "GPC") using tetrahydrofuran as a solvent, based on the molecular weight of polystyrene. It is the value converted.

The ratio of the silicone group in the hydrophilic polymer is preferably 10 to 50 parts by mass as the monomer having a silicone group with respect to 100 parts by mass of the monomer used. If the amount is less than 10 parts by weight, the water-repellent effect of silicone may not be exhibited. On the other hand, if the amount exceeds 50 parts by weight, the compatibility of the hydrophilic polymer with the hydrophobic polymer is decreased and the transparency of the coating film is reduced. May be lacking.

The hydrophilic polymer has an acid value of 20 to 20.
It is preferably 400 mgKOH / g, more preferably 40 to 200 mgKOH / g and having an acid value of 2.
If it is less than 0 mgKOH / g, the dispersion stability may decrease, and if the acid value exceeds 400 mgKOH / g, the water resistance or alkali resistance of the cured film may decrease.

When a highly hydrophobic monomer such as 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate and styrene is used as a monomer constituting the copolymer, the acid value is 100 to 400 mgKO.
It is preferably H / g.

In the present invention, the hydrophilic polymer is prepared by neutralizing a part or all of its acidic groups with an alkaline compound to form a salt of the acidic group, and then dissolving or dispersing it in an aqueous medium to prepare an aqueous composition. It is preferable to use as a product,
The resulting aqueous composition has excellent stability.

The method of forming the salt of the hydrophilic polymer obtained by solution polymerization is a conventional method, for example, a method of adding the hydrophilic polymer to an aqueous medium with stirring, or a method in which the hydrophilic polymer is treated with an alkaline compound. A method may be mentioned in which the salt of an acidic group is added to the mixture to add it to an aqueous medium with stirring. The organic solvent used for the solution polymerization is preferably removed by distillation after the dispersion in the aqueous medium is completed.

As the alkaline compound, ammonia,
Organic amines, and inorganic bases such as sodium hydroxide and potassium hydroxide can be cited. Among these, evaporation and scattering from the cured film during drying, the cured film finally obtained is excellent in water resistance, Ammonia or low molecular weight organic amines are preferred.

Examples of the low molecular weight organic amines include trialkylamines such as trimethylamine, triethylamine and tributylamine, and hydroxyalkylamines such as N, N-dimethylethanolamine, N-methyldiethanolamine and triethanolamine. .

The neutralization ratio of the acidic groups is preferably 10 to 100% of the acidic groups in the polymer, more preferably 30 to 100%, and this ratio is 10%.
If the amount is less than%, the hydrophilicity of the polymer may be insufficient and it may be difficult to dissolve or disperse it in the aqueous medium.

The alkaline compound is preferably added in an amount required for the above neutralization. When an excessive amount of alkaline compound is used, particularly when ammonia or amine is used as the alkaline compound, an odor may remain in the aqueous composition.

<Hydrophobic Polymer> The composition of the present invention contains a hydrophobic polymer insoluble in an aqueous medium (hereinafter, simply referred to as “hydrophobic polymer”) as an essential component. By blending a hydrophobic polymer, the weather resistance of the coating film obtained,
Water resistance can be improved.

The above-mentioned hydrophobic polymer preferably contains a maleimide group. The maleimide group in the hydrophobic polymer causes a photocrosslinking reaction with the maleimide group in the hydrophilic polymer or the hydrophobic polymer to improve water resistance and further improve weather resistance, and the hydrophilic component is It can be expected to have the effect of preventing the water from flowing out of the coating film due to rain or the like. The ratio of the maleimide group in the hydrophobic polymer is 0.04 to 4 mm
ol / g is preferable, and more preferably 0.2 to 3 mmo.
1 / g.

The composition of the present invention is aqueous, and a hydrophobic polymer is also used by dispersing it in an aqueous medium. Examples of means for dispersing in an aqueous medium include a method of dispersing with an emulsifier and obtaining a dispersion by emulsifier-free polymerization without using an emulsifier.

In the present invention, the hydrophobic polymer is
Those produced by emulsion polymerization are preferable, and by emulsion polymerization, particles of the polymer can be obtained as those uniformly dispersed in an aqueous medium, and an extremely high molecular weight polymer can be obtained, and its molecular weight Due to the effect, performance such as toughness and durability can be expected.

The hydrophobic polymer used in the present invention has been conventionally produced by emulsion polymerization.
Examples thereof include acrylic acid ester-based polymers, vinyl acetate-based polymers, ethylene-vinyl acetate copolymer-based polymers, styrene-butadiene-based polymers and vinylidene chloride-based polymers.

Among these, a (meth) acrylic acid ester-based polymer having a (meth) acrylate as a main constituent monomer, which is excellent in transparency and weather resistance of a coating film and is suitable for paints and coating fields, is preferable, and a maleimide is preferable. A (meth) acrylic acid ester-based polymer having a group is more preferable.

The (meth) acrylate as a raw material monomer used in the (meth) acrylic acid ester-based polymer is
The same examples as those mentioned in the description of the hydrophilic polymer can be mentioned, but the alicyclic alkyl (meth) acrylate is preferable from the viewpoint that the cured film obtained has excellent weather resistance.

When the (meth) acrylic acid ester-based polymer is prepared, a copolymerizable monomer can be used if necessary, and examples thereof include styrene, α-methylstyrene, (meth) acrylonitrile, Monomers such as vinyl acetate, (meth) acrylic acid, maleic acid, itaconic acid, (meth) acrylamide, N-methylolacrylamide and N-alkoxymethylacrylamide are used in combination.

As a method for imparting a maleimide group to the above-mentioned polymer, particularly a (meth) acrylic acid ester-based polymer, a method of copolymerizing the above-mentioned maleimide-based unsaturated compound is an easy method. It is mentioned as a preferable one.

As the emulsion polymerization method, the known method described above in the preparation of the hydrophilic polymer may be applied. As the polymerization initiator, potassium peroxodisulfate (potassium persulfate) and peroxodisulfate may be used. Examples thereof include persulfates such as potassium (ammonium persulfate), and peroxides such as hydrogen peroxide, benzoyl peroxide and t-butyl hydroperoxide.

These may be used as a redox type initiator in combination with a reducing agent such as sodium bisulfite and ascorbic acid, and azo compounds such as azobisisobutyronitrile, azobiscyanovaleric acid and salts thereof are also used. A water-soluble polymerization initiator is preferable as the polymerization initiator.

As the emulsifier and the chain transfer agent, the above-mentioned ones are used, and as the preferable emulsifier, a radical-polymerizable surface active agent can be mentioned from the viewpoint that the cured film obtained has excellent water resistance. .

The hydrophobic polymer obtained by the emulsion polymerization method is obtained as fine particles dispersed in an aqueous medium,
The average particle size of the hydrophobic polymer is 0.01.
To 0.5 μm is preferable, and 0.05 to 0.25 μm
More preferred is one having less than 0.01 μm,
If the viscosity of the emulsion is too high, and if it exceeds 0.5 μm, the dispersion stability of the particles and the transparency and smoothness of the dried coating film may be reduced.

The hydrophobic polymer preferably used in the present invention has a molecular weight of 10,000 to 1,000,000, more preferably 50,000 to 500,000.

<Aqueous Crosslinking Resin Composition> The ratio of the hydrophilic polymer to the hydrophobic polymer constituting the composition is preferably 1:99 to 50:50, more preferably a solid content ratio. Is 5:95 to 30:70. If the ratio of the hydrophilic polymer is less than 1, the silicone component in the coating film will be insufficient, and the water repellency of the coating film will not be obtained. If it exceeds 50, the water resistance and weather resistance may be poor.

The composition of the present invention is an aqueous composition, and the solid content in water is usually 30 to 70% by mass, preferably 40 to 60% by mass. This ratio is 3
If it is less than 0% by mass, it becomes difficult to dry, or
The coatability may be insufficient, while if it exceeds 70% by mass, the viscosity of the composition may increase and the workability may decrease.

Since the composition of the present invention cures even in sunlight, when this composition is used as an outdoor paint, it cures and crosslinks by sunlight even if it is not particularly irradiated with active energy rays to form a cured film. Although it has excellent physical properties,
It can also be crosslinked by irradiation with active energy rays.

Before irradiating with active energy rays, the coated surface is heated to use water as a dispersion medium and ammonia or an organic amine as an alkaline compound.
It is preferable to evaporate and scatter these, which reduces the film strength and transparency when water remains in the film,
Further, it is possible to prevent the deterioration of odor and weather resistance when ammonia or organic amine remains in the film.

When the composition of the present invention is crosslinked by irradiation with active energy rays, the active energy rays include
Ultraviolet rays, X-rays, electron beams and the like can be mentioned, but it is preferable to use ultraviolet rays because an inexpensive device can be used.

In the case of curing with ultraviolet rays, various light sources can be used, and examples thereof include a high pressure mercury lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge lamp and a carbon arc lamp.

In the composition of the present invention, if necessary, a filler such as barium sulfate, silicon oxide, talc, clay and calcium carbonate; for coloring phthalocyanine blue, phthalocyanine green, titanium oxide, carbon black and the like. Pigment: butyl carbitol, butyl carbitol acetate, 2,2,4-trimethylpentanediol-
1,3-monoisobutyrate (Product name: Texanol,
A film forming aid such as CS-12); an adhesion promoter; a leveling agent; and various additives such as an antifoaming agent can also be blended. The blending ratio when these are blended is preferably 100 parts by mass or less with respect to 100 parts by mass of the polymer.

<Uses> The composition of the present invention includes coating materials such as paints, coating materials and printing inks, bonding agents for non-woven fabrics, adhesives, fillers and resists, which can be preferably used as coating materials. More preferably, it is suitable for outdoor paints.

When the composition of the present invention is used as a coating material (hereinafter referred to as "coating material composition"), if necessary, a synthetic resin such as an acrylic resin, a ketone resin and a petroleum resin, an inorganic or organic resin. Fillers such as extender pigments, matting agents, sanding aids, leveling agents, defoaming agents, thickeners, pigment dispersants, gloss imparting agents, slip agents, and various additives such as thixotropic agents. You may mix.

The base material to which the coating composition can be applied is
Wood such as natural wood and synthetic wood, polycarbonate,
Molded resin processed products (plastics) such as polymethylmethacrylate and polyvinyl chloride, metal, glass, concrete, stone materials and paper can be mentioned, but the aqueous composition of the present invention has a cured film obtained with weather resistance. It is excellent and has water repellency derived from silicone for a long period of time outdoors, so it can be suitably used as an outdoor paint.

As a method of using the coating material composition, when the composition is applied outdoors to the substrate, the maleimide group is cured by sunlight after the water content is evaporated by drying. On the other hand, a method of irradiating with active energy rays after coating the base material in advance can also be mentioned.

As a coating method, a conventionally known method such as a roll coater, a flow coater, spraying, dipping and brush coating may be used, and an active energy ray irradiation method may be a conventional method.

[0086]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. In the following, “%” means mass% and “part” means mass part. The abbreviations used are shown below. THPI-A; 3,4,5,6-tetrahydrophthalimidoethyl acrylate [compound represented by the following formula (11)]

[0087]

[Chemical 12]

BA; n-butyl acrylate BMA; n-butyl methacrylate CHMA; cyclohexyl methacrylate HEMA; 2-hydroxyethyl methacrylate MAA; methacrylic acid DM; n-dodecyl mercaptan X-22-174DX; Shin-Etsu Kagaku Co., Ltd., Silicone macromonomer (number average molecular weight 5000) -MEK; methyl ethyl ketone-AIBN; 2,2'-azobisisobutyronitrile

Production Example (Aqueous solution of hydrophilic polymer A-1,
Preparation of A′-1 and A′-2) A flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100 parts of MEK, and the monomers shown in Table 1 below were added at 80 ° C. under a nitrogen atmosphere. , The chain transfer agent and the polymerization initiator are added dropwise over 2 hours, and after the completion of the addition, AIBN
An additional 0.5 part was added and maintained for another 2 hours. To the obtained reaction solution, 150 g of 1.2% aqueous ammonia solution was gradually added with stirring, and then methyl ethyl ketone was distilled off at a temperature of 50 ° C. under reduced pressure to obtain an aqueous solution of a hydrophilic polymer (A- 1, A′-1, A′-2, in each case, a solid content of 40%) was obtained.

[0090]

[Table 1]

Production Example (Aqueous Dispersion of Hydrophobic Polymer B-
1. Preparation of B-2) Each monomer shown in Table 2 was mixed, and deionized water 100 was added.
Parts and emulsifier (Aqualon HS10) 1 part (active ingredient)
And a rotary homomixer were used to prepare a monomer emulsion. A flask containing 52 parts of deionized water, 1 part of APS and 1 part of emulsifier (active ingredient) was replaced with nitrogen to raise the temperature to 80 ° C., the monomer emulsion was added dropwise over 2 hours, and aged for 2 hours as it was. After that, 2 parts of an aqueous ammonia solution (10%) was added to adjust the pH to obtain an aqueous dispersion of a hydrophobic polymer (B-1, B-2, solid content 40% in each case).

[0092]

[Table 2]

<Examples 1 and 2, Comparative Examples 1 to 4> According to the formulation table shown in Table 3, an aqueous solution of a hydrophilic polymer and an aqueous dispersion of a hydrophobic polymer were mixed under stirring to form an aqueous cross-linking type. A resin composition was obtained. In the table, DPNB is dipropylene glycol-n-butyl ether, RM-as a film forming aid.
8W shows Primal RM-8W made by Nippon Acrylic Co., Ltd. as a thickener. The obtained composition was used and evaluated according to the following methods. The results are shown in Table 4.

[0094]

[Table 3]

<Evaluation> The obtained composition was applied to an aluminum plate with a bar coater at room temperature to a film thickness of 50 μm. After coating, exposed at 45 ° angle to the outdoors (south surface in fine weather) for 2 hours and exposed to the outdoors (south surface) for about 3 months (April 2, 2001 to July 6, 2001). The coating film (exposure condition) was subjected to the following evaluation tests.

<Evaluation Items> a. The water whitening resistance test body was immersed in warm water at a temperature of 40 ° C. for 1 day, and the whitening level during the immersion of the film was visually evaluated. ◯: No whitening Δ: Slight whitening x: Whitening b. After the water-repellent coating, the coating surface of the test body was tilted at 45 ° and fixed in a thermostatic chamber at 20 ° C., one drop of distilled water was dropped from the biuret, and the state of water drop was observed. (Conforms to JIS P 8137) ○: Water droplets completely roll off △: Most of the dropped water droplets roll off, but some remain as small water droplets on the coating film ×; Water droplets do not flow off coating film Remains stretched over

[0097]

[Table 4]

[0098]

The composition of the present invention is excellent in water resistance and weather resistance, and by imparting a component that crosslinks with sunlight to the silicone component, it prevents the silicone component from flowing out of the coating film due to rain or the like. However, since it retains water repellency for a long time outdoors, it is particularly useful as a water-repellent coating agent used outdoors.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Taguchi             1 Toago, 1 Funami-cho, Minato-ku, Nagoya-shi, Aichi             Synthetic Co., Ltd. F-term (reference) 4J002 AC08W BB06W BC05W BD10W                       BF02W BF03W BG01X BG04W                       BG07X BN17X CP06X CP09X                       CP10X CP12X CP17X FD010                       FD090 GH01 GH02 GJ01                       GP03

Claims (3)

[Claims] 1. An aqueous crosslinkable resin composition comprising a hydrophilic polymer having a maleimide group, a silicone group and an acidic group or a salt thereof and a hydrophobic polymer as essential components. 2. The aqueous crosslinkable resin composition according to claim 1, wherein the hydrophobic polymer is a polymer having a maleimide group. 3. The aqueous crosslinkable resin composition according to claim 1 or 2, wherein the maleimide group is a group represented by the following formula (1). [Chemical 1] [However, in the formula (1), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group or an aryl group, or each of them forms a carbocycle. Represents a group. ]