WO2009133760A1 - Active-energy-ray-curable aqueous resin composition, active-energy-ray-curable coating material, method for production of cured coating film, and article - Google Patents

Abstract

Disclosed is an active-energy-ray-curable aqueous resin composition which enables the production of a cured coating film having excellent abrasion resistance, excellent water resistance and excellent hot water resistance/adhesiveness. The active-energy-ray-curable aqueous resin composition comprises: a solution having an acrylic resin (A) dissolved or dispersed in water; and a compound (B) which contains a polymerizable unsaturated double bond in an amount of 8.6 to 10.5 mmol/g and is dispersed in the solution, wherein the acrylic resin (A) is produced by using a monomer represented by general formula (1) in an amount of 2 to 15 wt% relative to the weight of the resin component and methyl methacrylate in an amount of 55 to 70 wt% relative to the weight of the resin component and contains a neutralized carboxyl group in an amount of 0.80 to 1.29 mmol/g. In the composition, the ratio between the content of the acrylic resin (A) and the content of the compound (B) (i.e., a (B)/(A) ratio) is 1.5 to 6 by weight. [In general formula (1), R¹ represents a hydrogen atom or a methyl group; R² represents an alkylene group having 2 to 8 carbon atoms; and n represents an integer of 1 to 10.]

Description

Active energy ray-curable aqueous resin composition, active energy ray-curable coating material, method for forming cured coating film, and article

The present invention is used for a coating agent for plastics, films, etc., and has an appearance of a cured coating film, an active energy ray-curable aqueous resin composition excellent in wear resistance and water resistance, and the composition The present invention relates to an active energy ray-curable coating material, a method for forming a cured coating film using the coating material, and an article on which the cured coating film of the coating material is disposed.

The active energy ray-curable composition is used as a hard coating agent for plastic substrates for home appliances, mobile phones, etc., because it has a low heat history on the coating substrate and excellent coating film hardness and scratch resistance. . Examples of such an active energy ray-curable composition include a polymer having a polymerizable unsaturated double bond (for example, acrylic acrylate) and a polymer having substantially no polymerizable unsaturated double bond (for example, And an active energy ray-curable composition (non-aqueous active energy ray-curable composition) containing a polymerizable monomer and an organic solvent as a diluent. When this active energy ray-curable composition is used as, for example, an active energy ray-curable paint for spray coating, the organic solvent is contained in a large amount of 50 to 90% by weight based on the weight of the paint. Therefore, when an active energy ray-curable coating material containing the resin composition is used to form a cured coating film on the surface of a substrate such as plastic, the working environment is deteriorated by volatilization of the organic solvent in the coating material. There's a problem. Further, the volatilized organic solvent causes air pollution.

In such circumstances, an active energy ray-curable aqueous composition containing water as a diluent has been studied. Specifically, for example, in the aqueous resin dispersion (1) having an average particle diameter of 10 to 100 nm, the photosensitive oligomer (2) having at least one carbon-carbon double bond in the molecule and the molecule An aqueous photosensitive coating composition comprising a photosensitive monomer (3) having at least one carbon-carbon double bond is disclosed (for example, see Patent Document 1). Specifically, for example, in Example 1 of Patent Document 1, acrylic fine particle emulsion (for example, NANOCRYL BCX-2914 manufactured by Toyo Ink Mfg. Co., Ltd.) and 100 parts by weight of water-soluble urethane acrylate and A photosensitive coating composition comprising 2.3 parts by weight of trimethylolpropane triacrylate is disclosed.

Also disclosed is an ultraviolet curable aqueous coating composition that contains a (meth) acryloyl group-containing water-soluble resin (A), a polyfunctional (meth) acrylate compound (B), and a photopolymerization initiator and is in an emulsified state. (For example, refer to Patent Document 2). Specifically, for example, an emulsion in which a water-dispersible acrylic resin obtained by neutralizing a carboxyl group of a carboxyl group-containing acrylic resin obtained by using methyl methacrylate as essential and a urethane acrylate oligomer are dispersed in water can be mentioned. .

In order to obtain an active energy ray-curable resin composition using the acrylic fine particle emulsion used in Patent Document 1, a hydrophobic polymerizable monomer effective for improving wear resistance and water resistance and a water-soluble composition are used. Water-soluble urethane acrylate or self-emulsifiable urethane acrylate together with water-soluble urethane acrylate or self-emulsifiable urethane acrylate, and supplementing the dispersion power and stability of the acrylic fine particle emulsion, Dispersed in water. Therefore, the effect of the hydrophobic polymerizable monomer that can be expected to improve wear resistance and water resistance is not sufficiently exhibited, and the cured coating film obtained using the aqueous photosensitive coating composition of Patent Document 1 is resistant to Abrasion and water resistance are not sufficient.

Moreover, in the ultraviolet curable aqueous coating composition disclosed in Patent Document 2, a hydrophobic urethane acrylate oligomer is used as the polyfunctional (meth) acrylate, and thereby the scratch resistance and water resistance of the cured coating film are used. We are trying to improve. However, even the (meth) acryloyl group-containing water-soluble resin (A) used in the UV-curable aqueous coating composition does not have sufficient dispersion power to disperse the hydrophobic urethane acrylate oligomer in water. The polyfunctional (meth) acrylate compound (B) cannot be well dispersed in the (meth) acryloyl group-containing water-soluble resin (A) in water, or the polyfunctional (meth) acrylate compound (B) There is a problem that some parts are separated immediately. Therefore, defects such as repellency and orange peel are likely to occur in the cured coating film. Further, the ultraviolet curable aqueous coating composition is not sufficient in storage stability.

JP-A-9-302266 JP 2004-010779 A

An object of the present invention is to use an active energy ray-curable aqueous resin composition that is used for a coating agent for plastics, films and the like, has a good appearance of the cured coating film, and has excellent wear resistance and water resistance, and the composition It is to provide an active energy ray-curable coating material containing a coating material, a method for forming a cured coating film using the coating material, and an article in which the cured coating film of the coating material is disposed.

As a result of intensive studies, the present inventors have found the following findings.
(1) A radically polymerizable monomer containing an alkylene group having 2 to 8 carbon atoms and having a carboxyl group added to the terminal of the alkylene group is 2 to 15 wt. Acrylic resin obtained by using methyl (meth) acrylate in an amount of 55 to 70% by weight based on the weight of the resin-forming component, and containing 0.80 to 1.29 mmol / g of neutralized carboxyl groups A resin dispersion in which (hydrophilic acrylic resin) is dispersed in water can favorably disperse a hydrophobic polymerizable monomer. Therefore, by using an active energy ray-curable water-based paint containing these, a cured coating film that hardly causes repelling or orange peel can be obtained.

(2) A compound having a polymerizable unsaturated double bond of 8.6 to 10.5 mmol / g is used as the hydrophobic polymerizable monomer, and the content ratio between the resin dispersion and the compound is calculated in terms of weight. By using an active energy ray-curable water-based paint containing a composition of 1.5 to 6, a cured coating film in which repelling and orange peel are unlikely to occur can be obtained.

(3) Furthermore, the cured coating film obtained using the active energy ray-curable water-based paint is excellent in wear resistance and water resistance.

(4) After the active energy ray-curable coating material is applied to the surface of the substrate, the active energy ray-curable coating material is cured by irradiating the active energy ray, thereby curing the coating with excellent scratch resistance and water resistance. A film can be easily formed.

(5) An article formed by placing a cured coating film of the active energy ray-curable coating on the surface is covered with a cured coating film free from repelling or orange peel, and has a beautiful appearance. Moreover, since the cured coating film has scratch resistance and water resistance, the durability of the article is improved. Therefore, the value of the article is improved. Even when the active energy ray-curable coating material is used as an intermediate coating material, the durability of the article is improved by the intermediate coating layer having scratch resistance and water resistance.
The present invention has been completed based on the above findings.

That is, the present invention uses 2 to 15% by weight of the radically polymerizable monomer represented by the following general formula (1) based on the weight of the resin-forming component and methyl methacrylate based on the weight of the resin-forming component. In a resin solution obtained by using 55 to 70% by weight and containing 0.80 to 1.29 mmol / g of neutralized carboxyl group (A) in water or the acrylic resin ( An active energy ray-curable aqueous resin composition obtained by dispersing a compound (B) having a polymerizable unsaturated double bond of 8.6 to 10.5 mmol / g in a resin dispersion obtained by dispersing A) in water. The active energy ray curing characterized in that the ratio [(B) / (A)] of the acrylic resin (A) and the compound (B) is 1.5 to 6 in terms of weight. Providing a water-based resin composition A.

(R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 2 to 8 carbon atoms, and n is an integer of 1 to 10)

The present invention also provides an active energy ray-curable coating material characterized by containing the active energy ray-curable aqueous resin composition.

The present invention also provides a method for forming a cured coating film, comprising: applying the active energy ray-curable coating material to a substrate; and irradiating the active energy ray to cure the applied active energy ray-curable coating material. It is to provide.

Furthermore, the present invention provides an article comprising a cured coating film of the active energy ray-curable coating material.

The active energy ray-curable aqueous resin composition of the present invention has a good appearance of the cured coating film and is excellent in wear resistance and water resistance. Further, by using the active energy ray-curable coating material of the present invention, a cured coating film having a good appearance of the cured coating film and excellent in abrasion resistance and water resistance can be obtained. In addition, the cured coating film of the present invention has a good appearance, and a cured coating film having excellent wear resistance and water resistance can be easily obtained. Furthermore, the article of the present invention has a cured coating film excellent in wear resistance and water resistance.

The acrylic resin (A) used in the present invention uses 2 to 15% by weight of the radical polymerizable monomer represented by the general formula (1) based on the weight of the resin forming component, and methyl methacrylate as the resin forming component. And from 0.80 to 1.29 mmol / g of neutralized carboxyl groups. If an acrylic resin is used in which the amount of the radically polymerizable monomer represented by the general formula (1) is less than 2% by weight based on the weight of the resin-forming component, the dispersion stability is insufficient and precipitates or separations occur. This is not preferable because the active energy ray-curable aqueous resin composition has insufficient storage stability. When an acrylic resin in which the amount of the radically polymerizable monomer represented by the general formula (1) is greater than 15% by weight based on the weight of the resin-forming component is used, the resin becomes flexible and has insufficient wear resistance. Since it becomes an active energy ray hardening-type resin composition from which only a coating film is obtained, it is not preferable. The acrylic resin (A) used in the present invention is an acrylic resin obtained by using 3 to 10% by weight of the radically polymerizable monomer represented by the general formula (1) based on the weight of the resin-forming component. It is preferable because it becomes a good active energy ray-curable aqueous resin composition.

In addition, when methyl methacrylate is used in an acrylic resin less than 55% by weight based on the weight of the resin-forming component, problems such as insufficient dispersion stability, sedimentation and separation occur, and storage stability is insufficient. It is not preferable because it becomes a new active energy ray-curable aqueous resin composition. When an acrylic resin in which the amount of methyl methacrylate used is larger than 70% by weight based on the weight of the resin forming component, the fluidity of the acrylic resin is lowered and the leveling property is deteriorated, resulting in deterioration of the coating film appearance. The resulting acrylic resin has a very high viscosity, which is not preferable because it becomes an active energy ray-curable aqueous resin composition that is difficult to handle. The acrylic resin (A) used in the present invention is an active energy ray-curable aqueous resin composition having good storage stability, obtained by using 55 to 65% by weight of methyl methacrylate based on the weight of resin formation Further, it is preferable because the resulting cured coating film is excellent in appearance and substrate adhesion.

The acrylic resin (A) used in the present invention contains a neutralized carboxyl group in the range of 0.80 to 1.29 mmol / g. When an acrylic resin having a neutralized carboxyl group content of less than 0.80 mmol / g is used, the appearance of the cured coating film of the active energy ray curable resin composition or the active energy ray curable coating of the present invention may be repelled. This is not preferable because it generates shading. When an acrylic resin having a neutralized carboxyl group content of more than 1.29 mmol / g is used, the water resistance of the cured film of the active energy ray curable resin composition or the active energy ray curable coating of the present invention is lowered. This is not preferable. The acrylic resin (A) used in the present invention is an acrylic resin containing a neutralized carboxyl group in the range of 0.80 to 1.29 mmol / g. An active energy ray-curable resin composition and an active energy ray-curable coating composition excellent in water resistance are preferable, and an acrylic resin containing a neutralized carboxyl group in a range of 0.90 to 1.20 mmol / g is more preferable. preferable.

The content (molar amount) of the neutralized carboxyl group was determined to be the same (same molar amount) as the molar amount of the basic compound calculated from the amine value of the basic compound used for neutralization. Here, the amine value of the basic compound used for neutralization was determined by dissolving 1.0 g of a basic compound sample in 5 ml of tetrahydrofuran and neutralizing with 0.5 mol / l hydrochloric acid solution using bromophenol blue as an indicator. I went and asked.

As the acrylic resin (A) used in the present invention, for example, the radical polymerizable monomer represented by the general formula (1) is used in an amount of 2 to 15% by weight based on the weight of the resin forming component, and methyl methacrylate is used as the resin. An acrylic resin (a) obtained by using 55 to 70% by weight based on the weight of the forming component and containing a carboxyl group is synthesized, and then the carboxyl group in the acrylic resin (a) is neutralized with a basic compound. It can be obtained by things.

The acrylic resin (A) used in the present invention contains a neutralized carboxyl group in the range of 0.80 to 1.29 mmol / g as described above. In order to obtain such an acrylic resin (A), for example, an acrylic resin containing a carboxyl group in the range of 0.80 to 1.29 mmol / g is used as the acrylic resin (a). A method of neutralizing all carboxyl groups with a basic compound (neutralization rate 100%), an acrylic resin containing 1.29 mmol / g or more of carboxyl groups as the acrylic resin (a), and the carboxyl of the acrylic resin (a) It can be obtained by a method of neutralizing a part of the group with a basic compound. As a specific example of the method of neutralizing a part of the carboxyl group with a basic compound, for example, a part of the carboxyl group in the acrylic resin (a) having an acid value of 100 mgKOH / g, for example, 60% is neutralized. A part of the carboxyl groups in the acrylic resin (a) having an acid value of 80 mgKOH / g prepared so that the content of neutralized carboxyl groups is 1.07 mmol / g in the resin, for example, 80% And the neutralized carboxyl group content is adjusted to 1.14 mmol / g in the resin.

The acrylic resin (A) used in the present invention uses an acrylic resin containing a carboxyl group in the range of 1.3 to 2.7 mmol / g, and the neutralized carboxyl group of this resin is 0.80 to 1.29 mmol. A / g acrylic resin is preferred because an active energy ray-curable aqueous resin composition and an active energy ray-curable coating material having excellent appearance of the cured coating film and excellent wear resistance and water resistance can be obtained. The acrylic resin (a) is preferably an acrylic resin having an acid value of 75 to 150 mgKOH / g.

In the present invention, the acid value of the carboxyl group-containing acrylic resin (a), etc. is 0.1 mol by dissolving 1.0 g of a resin sample in a mixed solution of 1.5 ml of toluene and 3.5 ml of methanol and using phenolphthalein as an indicator. It was determined by performing neutralization titration with a / l potassium hydroxide / ethanol solution.

The carboxyl group-containing acrylic resin (a) includes, for example, 2 to 15% by weight of the radical polymerizable monomer represented by the general formula (1) based on the weight of the resin forming component and methyl methacrylate as the resin forming component. Based on the weight of the monomer, 55 to 70% by weight and a carboxyl group-containing ethylenically unsaturated monomer as an essential component, and if necessary, a mixture in which other polymerizable monomers are mixed, are used. Can be synthesized by a solution polymerization method in which a radical polymerization reaction is performed in the presence of a polymerization initiator. This reaction may be carried out under normal pressure or high pressure, and the molecular weight can be adjusted, for example, by adjusting the amount of the polymerization initiator charged.

Examples of the radical polymerizable monomer represented by the general formula (1) include ε-carboxypolycaprolactone (meth) acrylate. Specific examples include ε-carboxypolycaprolactone acrylate and ε-carboxypolycaprolactone methacrylate. Among them, ε-carboxypolycaprolactone acrylate is preferable because it is stably supplied to the market and is easily available.

The ε-carboxypolycaprolactone (meth) acrylate can be obtained, for example, by mixing (meth) acrylic acid and ε-caprolactone in the presence of an acid catalyst, stirring and reacting at 40 to 150 ° C.

Examples of the acid catalyst include p-toluenesulfonic acid, benzenesulfonic acid, aluminum chloride, stannic chloride and the like. The acid catalyst is preferably used in an amount of 1 to 20 parts by weight per 100 parts by weight of (meth) acrylic acid.

Examples of the carboxyl group-containing ethylenically unsaturated monomer include (meth) acrylic acid, crotonic acid, isocrotonic acid, 2-methacryloxyethyl succinic acid, 2-methacryloxyethyl hexahydrophthalic acid, 2-methacrylic acid. Roxyethyl glutarate; dicarboxylic acid such as (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid and its anhydride; monomethylmaleic acid, monoethylmaleic acid, monobutylmaleic acid, monooctylmaleic acid, monomethylfumaric acid Monoethyl fumaric acid, monobutyl fumaric acid, monooctyl fumaric acid, monomethyl itaconic acid, monoethyl itaconic acid, monobutyl itaconic acid, monoalkyl esters of dicarboxylic acids such as monooctyl itaconic acid, and the like. The carboxyl group-containing ethylenically unsaturated monomer is preferably (meth) acrylic acid such as acrylic acid or methacrylic acid. The carboxyl group-containing ethylenically unsaturated monomer may be used alone or in combination of two or more. Among the carboxyl group-containing ethylenically unsaturated monomers, acrylic acid is preferable because an acrylic resin (A) having a low viscosity and excellent dispersibility can be obtained. The amount of (meth) acrylic acid such as acrylic acid or methacrylic acid is preferably 10 to 15% by weight based on the weight of the resin-forming component.

Examples of the other ethylenically unsaturated monomers include methyl acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, and iso- Butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, docosanyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) Alkyl (meth) acrylates such as acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cycloalkyl (meth) acrylate;

Addition of lactones such as ε-caprolactone or γ-valerolactone to hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate, and monomers thereof Hydroxyl-containing ethylenically unsaturated monomers such as

Aromatic vinyl compounds such as styrene, p-tert-butylstyrene, α-methylstyrene, vinyltoluene;

Ω-alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and 4-methoxybutyl (meth) acrylate; tertiary amide group-containing vinyl monomers such as N, N-dimethyl (meth) acrylamide Vinyl monomers having a polyalkylene oxide structure such as methoxypolyethylene glycol (meth) acrylate and methoxypolypropylene glycol (meth) acrylate; n-methylol (meth) acrylamide, n-methoxymethyl (meth) acrylamide, n-ethoxy Alkoxymethyl (meth) acrylamides such as methyl (meth) acrylamide, n-butoxymethyl (meth) acrylamide, iso-butoxymethyl (meth) acrylamide;

Secondary amino group-containing vinyl monomers such as n-methylaminoethyl (meth) acrylate; vinyl monomers having an active methylene group such as vinyl acetoacetate and 2-acetoacetoxyethyl (meth) acrylate; vinyl trimethoxy Vinyl monomers having hydrolyzable silyl groups such as silane and 3- (meth) acryloyloxypropyltrimethoxysilane;

Vinyl monomers containing silyl ester groups such as trimethylsilyl (meth) acrylate; glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, glycidyl vinyl ether, allyl glycidyl ether, etc. An isocyanate group such as 2-isocyanate propene, 2-isocyanate ethyl vinyl ether, 2-isocyanate ethyl methacrylate, m-isopropenyl-α, α-dimethylbenzyl isocyanate; Examples thereof include vinyl monomers. These may be used alone or in combination of two or more.

The acrylic resin (A) used in the present invention is preferably an acrylic resin that does not have a polymerizable unsaturated bond because a cured coating film that relaxes curing shrinkage and is excellent in substrate adhesion can be obtained. When preparing the radical polymerizable monomer represented by the general formula (1), methyl methacrylate, carboxyl group-containing ethylenically unsaturated monomer and other polymerizable monomers as raw materials, polymerizable unsaturated In order to prepare an acrylic resin having no bond, for example, as a carboxyl group-containing ethylenically unsaturated monomer and other polymerizable monomers, a monomer having one ethylenically unsaturated monomer is used. It can be obtained by using.

The acrylic resin (A) used in the present invention is an active energy ray curable aqueous resin composition or an active energy ray curable type in which an acrylic resin having an alkyl group in the side chain is excellent in adhesion and a cured coating film having a good appearance can be obtained. It is preferable because a paint is obtained. Among the alkyl groups, a cured coating film having excellent adhesion and good appearance is obtained, and an active energy ray curable resin composition and an active energy ray curable coating material having excellent storage stability are obtained. An alkyl group having 2 to 8 atoms is more preferable. Examples of the alkyl group having 2 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, cyclohexyl group, 2- And an ethylhexyl group.

In order to obtain an acrylic resin having an alkyl group in the side chain as the acrylic resin (A), for example, it is obtained by using an ethylenically unsaturated monomer having an alkyl group in combination when synthesizing the acrylic resin (a). . Examples of the ethylenically unsaturated monomer having an alkyl group include the alkyl (meth) acrylates. The amount of the ethylenically unsaturated monomer having an alkyl group used for synthesizing the acrylic resin (a) is 1 to 25% by weight based on the weight of the resin forming component, and the active energy having excellent storage stability. The cured cured coating film is preferably a linear curable aqueous resin composition or an active energy radiation curable coating material, and also has good adhesion to the substrate and excellent appearance, and more preferably 3 to 20% by weight. Among the ethylenically unsaturated monomers having an alkyl group, n-butyl (meth) acrylate is preferable because it becomes an active energy ray-curable aqueous resin composition or an active energy ray-curable coating material that is more excellent in storage stability.

Among the acrylic resins (A) used in the present invention, an active energy ray-curable aqueous resin composition or active energy in which an acrylic resin having a hydroxyl group is excellent in storage stability and water resistance of the resulting cured coating film is also good. It is preferable because a wire curable coating is obtained. Among acrylic resins having a hydroxyl group, an acrylic resin having a hydroxyl value of 15 to 100 mgKOH / g is preferred, and an acrylic resin having a hydroxyl value of 25 to 65 mgKOH / g is more preferred.

Among the acrylic resins (A), an acrylic resin having a hydroxyl group includes, for example, a radical polymerizable monomer represented by the general formula (1) as the acrylic resin (a) based on the weight of the resin-forming component. 15% by weight, methyl methacrylate 55 to 70% by weight based on the weight of the resin-forming component, carboxyl group-containing ethylenically unsaturated monomer and hydroxyl group-containing ethylenically unsaturated monomer as essential components, and further required In accordance with a mixture of other polymerizable monomers, an acrylic resin is synthesized by a solution polymerization method in which a radical polymerization reaction is performed in the presence of a polymerization initiator in a solvent, and then a basic compound is used. It can be obtained by neutralizing the carboxyl group in the acrylic resin.

Examples of the hydroxyl group-containing ethylenically unsaturated monomer include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and the like. Among these, hydroxyethyl (meth) acrylate is preferable because an active energy ray-curable aqueous resin composition and an active energy ray-curable coating material excellent in storage stability can be obtained.

The amount of the hydroxyl group-containing ethylenically unsaturated monomer used when preparing an acrylic resin having a hydroxyl group as the acrylic resin (a) is preferably 3 to 20% by weight based on the weight of the resin-forming component.

In addition, the hydroxyl value of acrylic resin (A) and the like was determined by adding 25 ml of acetic anhydride / pyridine solution (volume ratio 1/19) to 10.0 g of a resin sample and heating to react for 1 hour, and then adding phenolphthalein. Used as an indicator, neutralization titration was performed with a 0.5 mol / l potassium hydroxide / ethanol solution.

As the solvent used in the synthesis of the acrylic resin (a), a water-miscible organic solvent that is miscible without being separated from water is preferable. In particular, the solubility in water (the number of grams of the organic solvent dissolved in 100 g of water) is 25. An organic solvent of 3 g or more is preferable at ° C. Examples of these water-miscible organic solvents include alcohol solvents such as methanol, ethanol, propanol, and butanol; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, and ethylene glycol. Diethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol And glycol ether solvents such as methyl monomethyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol dimethyl ether. . These water-miscible organic solvents may be used alone or in combination of two or more.

The water-miscible organic solvent can be used in combination with other organic solvents as necessary, for example, aromatic hydrocarbon solvents such as toluene and xylene; aliphatics such as hexane, heptane, octane and decane. Hydrocarbon solvents: Examples include ester solvents such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc. It is not preferable, and even when necessary, it is preferable to use 1% or less based on the total amount of the aqueous resin composition. Among the aromatic hydrocarbon solvents, examples of the mixed aromatic hydrocarbon solvent include commercially available products such as Solvesso # 100 and Solvesso # 150.

Examples of the radical polymerization initiator that can be used in the synthesis of the acrylic resin (a) by the solution polymerization method include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyro). Nitriles), azo compounds such as azobiscyanovaleric acid; tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroper Organic peroxides such as oxide, benzoyl peroxide, t-butyl hydroperoxide; inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, etc., and these may be used alone or in combination of two or more Can be used together. The radical polymerization initiator is preferably used within a range of 0.1 to 10% by weight with respect to the total amount of components constituting the acrylic resin.

The nonvolatile content in the reaction vessel at the time of the solution polymerization is preferably 30 to 90% by weight, and more preferably 50 to 80% by weight.

Examples of the neutralizing agent (basic compound) used to neutralize the carboxyl group in the acrylic resin (a) include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropyllamine, and dipropyl. Alkylamines such as ruamine tripropyllamine; monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, N-methylethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, 2-amino-2 Alkanolamines such as methylpropanol, 2- (dimethylamino) -2-methylpropanol, N-methyldiethanolamine; ethylenediamine, diethylenetriamine, triethyleneteto Min, organic amines or ammonia, such as polyvalent amines such as tetraethylene pentamine (water) and the like. Among basic compounds, ammonia water and trimethylamine are preferred because they are highly volatile and therefore hardly remain on the cured coating film, and a cured coating film having excellent water resistance can be obtained. The neutralizing agent (basic compound) may be used alone or in combination of two or more.

For example, by adding ε-caprolactone or the like to a carboxyl group-containing acrylic resin, an acrylic resin having a structure composed of a repeating unit of the compound represented by the general formula (1) and a hydrogen atom directly bonded thereto is obtained. be able to.

As the number average molecular weight (Mn) of the acrylic resin (a) used in the present invention, an active energy ray curable aqueous resin composition or an active energy ray curable coating material that is excellent in storage stability and does not increase in viscosity too much is used. From the viewpoint of being obtained, 5,000 to 30,000 is preferable, and 8,000 to 25,000 is more preferable.

As the weight average molecular weight (Mw) of the acrylic resin (a) used in the present invention, an active energy ray-curable aqueous resin composition or an active energy ray-curable coating material that is excellent in storage stability and does not increase in viscosity too much is used. From the viewpoint of being obtained, it is preferably 10,000 to 100,000, and more preferably 30,000 to 80,000.

In the present invention, the number average molecular weight and the weight average molecular weight of a resin such as a carboxyl group-containing acrylic resin (a) are measured using a gel permeation chromatograph and excluding components having a molecular weight of 1000 or less in terms of polystyrene under the following conditions. Asked.
Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Tosoh Co., Ltd. Guard column HXL-H
+ Tosoh Corporation TSKgel G5000HXL
+ Tosoh Corporation TSKgel G4000HXL
+ Tosoh Corporation TSKgel G3000HXL
+ Tosoh Corporation TSKgel G2000HXL
Detector: RI (differential refractometer)
Data processing; Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent Tetrahydrofuran Flow rate 1.0 ml / min Standard; Polystyrene sample; 0.4 wt% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl).

The glass transition temperature of the carboxyl group-containing acrylic resin (a) used in the present invention is 30 ° C. because an active energy ray-curable aqueous resin composition capable of obtaining a cured coating film excellent in abrasion resistance and substrate adhesion is obtained. It is preferably ˜100 ° C. Therefore, when synthesizing the acrylic resin (a), it is preferable to appropriately select and combine the raw material components so that the glass transition temperature is 30 ° C. to 100 ° C. 60 ° C. to 90 ° C. is more preferable because a cured coating film having better wear resistance and substrate adhesion can be obtained.

The glass transition temperature of the resin such as acrylic resin (a) was determined by differential scanning calorimetry (DSC) measurement according to JIS-K-7121.
Measuring device: TASC Instruments DSCQ-100
Container: Aluminum open cell Temperature rising rate: 20 ° C / min

The glass transition temperature of the resin such as the acrylic resin (a) can also be calculated by the following formula. In addition, the glass transition temperature of the following formula is an absolute temperature (° K).
Tg ⁻¹ = ΣXi · Tgi ⁻¹

Here, it is assumed that n monomer components of i = 1 to n are copolymerized in the resin. Xi is the weight fraction of the i-th monomer, and Tgi is the glass transition temperature of the homopolymer of the i-th monomer. The glass transition temperature of the monomer homopolymer was determined by Polymer Handbook (4 ^th Edition) J. ^MoI . Brandrup, E .; H. Immergut, E .; A. Values described by Gulke (Wiley Interscience) can be used.

In order to prepare the acrylic resin (A), it is preferable to synthesize the carboxyl group-containing acrylic resin (a) and then neutralize all or part of the carboxyl groups with a basic compound. Without using the acrylic resin (a) by using a monomer in which all or part of the carboxyl group-containing ethylenically unsaturated monomer used for the synthesis of the resin (a) is previously neutralized with a basic compound, The acrylic resin (A) may be directly prepared.

The compound (B) used in the present invention needs to have a polymerizable unsaturated double bond of 8.6 to 10.5 mmol / g. When the content of polymerizable unsaturated double bonds is less than 8.6 mmol / g, the abrasion resistance and water resistance of the cured coating film are insufficient because of insufficient crosslinking due to insufficient crosslinking. It is not preferable because it becomes a wire curable paint. If the content of the polymerizable unsaturated double bond is larger than 10.5 mmol / g, the adhesion of the resulting cured coating film to the substrate is not preferred. The compound (B) is a polymerizable unsaturated double bond because it becomes an active energy ray-curable aqueous resin composition or an active energy ray-curable coating material from which a cured coating film excellent in abrasion resistance, water resistance and adhesion can be obtained. Is preferably from 9.0 to 10.2 mmol / g, more preferably from 9.0 to 9.8 mmol / g of polymerizable unsaturated double bonds.

As the compound (B) having a polymerizable unsaturated double bond of 8.6 to 10.5 mmol / g used in the present invention, it may be used alone, but a compound having a polymerizable unsaturated double bond is mixed. Thus, it is preferable to use a mixture having an average content of polymerizable unsaturated double bonds of 8.6 to 10.5 mmol / g. As the compound having a polymerizable unsaturated double bond used at this time, a compound having a polymerizable unsaturated double bond in a content of 8.6 to 10.5 mmol / g may be used. Those having an unsaturated double bond of less than 8.6 mmol / g may be used, or those having a polymerizable unsaturated double bond of more than 10.5 mmol / g may be used.

A compound having a polymerizable unsaturated double bond of 8.6 to 10.5 mmol / g can be used alone to obtain a compound (B). Examples of such compounds include 1,6-hexanedi (meth) acrylate (polymerizable unsaturated double bond content: 8.8 mmol / g), diethylene glycol di (meth) acrylate (polymerizable unsaturated double bond). Bond content: 9.3 mmol / g), neopentyl glycol di (meth) acrylate (polymerizable unsaturated double bond content: 9.4 mmol / g), 1,4-butanediol di (meth) acrylate (Content of polymerizable unsaturated double bond: 10.1 mmol / g), trimethylolpropane tri (meth) acrylate (content of polymerizable unsaturated double bond: 10.1 mmol / g), pentaerythritol tri ( (Meth) acrylate (polymerizable unsaturated double bond content: 10.1 mmol / g), ditrimethylolpropane tetra (meth) acrylate (Content of polymerizable unsaturated double bond: 8.6 mmol / g), dipentaerythritol penta (meth) acrylate (content of polymerizable unsaturated double bond: 9.5 mmol / g), dipenta And erythritol hexa (meth) acrylate (polymerizable unsaturated double bond content: 10.4 mmol / g). Moreover, these compounds can also be used as a raw material at the time of preparing a compound (B) by mixing.

Examples of the compound having a polymerizable unsaturated double bond used when preparing the compound (B) by mixing are isobornyl (meth) acrylate (content of polymerizable unsaturated double bond: 4.8 mmol / g). ), Mono (meth) acrylates such as dicyclopentanyl (meth) acrylate (polymerizable unsaturated double bond content: 4.9 mmol / g);

Tripropylene glycol di (meth) acrylate (polymerizable unsaturated double bond content: 6.7 mmol / g), bisphenol A diglycidyl ether di (meth) acrylate (polymerizable unsaturated double bond content: 3 .3 mmol / g), neopentyl glycol di (meth) acrylate hydroxypivalate (content of polymerizable unsaturated double bond: 6.4 mmol / g), tricyclodecane dimethanol (meth) acrylate (polymerizable unsaturated) Content of double bond: 6.6 mmol / g), polyethylene glycol di (meth) acrylate having 9 ethylene oxide repeating units (content of polymerizable unsaturated double bond: 3.8 mmol / g), ethylene Polyethylene glycol di (meth) acrylate having 13 repeating oxide units (polymerization Unsaturated double bond content: 2.9 mmol / g), polypropylene glycol di (meth) acrylate having 7 propylene oxide repeating units (polymerizable unsaturated double bond content: 3.8 mmol / g) , Pentaerythritol di (meth) acrylate (polymerizable unsaturated double bond content: 8.2 mmol / g), dipentaerythritol tetra (meth) acrylate (polymerizable unsaturated double bond content: 8.5 mmol) / (G) di (meth) acrylates;

Tris (2- (meth) acryloyloxyethyl) isocyanurate (polymerizable unsaturated double bond content: 5.6 mmol / g), ethylene oxide-modified trimethylolpropane tri having three ethylene oxide chains per molecule ( Tri (meth) acrylates such as (meth) acrylate (content of polymerizable unsaturated double bond: 7.0 mmol / g);

Pentaerythritol tetra (meth) acrylate (content of polymerizable unsaturated double bond: 11.4 mmol / g), caprolactone-modified dipentaerythritol hexa (meth) acrylate (content of polymerizable unsaturated double bond: 6. And poly (meth) acrylates such as 5 mmol / g) and acryloylmorpholine (content of polymerizable unsaturated double bond: 7.1 mmol / g).

Among them, it is preferable to use dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate because a film having high curability and excellent wear resistance can be obtained, and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate is more preferable. preferable.

Further, as the compound (B), diisocyanate compounds such as tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, norbornane diisocyanate, further an isocyanate prepolymer obtained from these diisocyanate compound and polyol, and further from these diisocyanate compounds Triisocyanate compounds that are nurate bodies and burette bodies and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc. Urethane (meth) acrylate which is a reaction product with hydroxyl group-containing (meth) acrylate Polymerizable unsaturated double bonds such as mono-, di-, tri- or higher polyesters of polybasic acid and hydroxyalkyl (meth) acrylate, bisphenol A type epoxy acrylate, novolak type epoxy acrylate, etc. Examples include oligomers or prepolymers having a bond. These may be used alone or in combination of two or more if the polymerizable unsaturated double bond is 8.6 to 10.5 mmol / g. In addition, these compounds having a polymerizable unsaturated double bond, a compound having a polymerizable unsaturated double bond content of less than 8.6 mmol / g or a compound having a content of more than 10.5 mmol / g, It can be used if it is used in combination with a compound having a polymerizable unsaturated double bond and the average polymerizable unsaturated double bond is from 8.6 to 10.5 mmol / g. In addition, as urethane (meth) acrylate, the urethane (meth) acrylate which is a reaction product of a diisocyanate compound and pentaerythritol tri (meth) acrylate is preferable.

In order to obtain a compound (B) used in the present invention by mixing two or more compounds having a polymerizable unsaturated double bond, for example, dipentaerythritol hexaacrylate (content of polymerizable unsaturated double bond: 10) 0.4 mmol / g) and tripropylene glycol diacrylate (polymerizable unsaturated double bond content: 6.7 mmol / g) are mixed at a weight ratio of 80:20. As a result, the mixture has a polymerizable unsaturated double bond of 9.6 mmol / g and can be used as the compound (B).

The compounds (B) may be used alone or in combination of two or more.

As the compound (B) used in the present invention, since it becomes an active energy ray-curable aqueous resin composition or an active energy ray-curable coating material from which a cured coating film excellent in abrasion resistance is obtained, dipentaerythritol pentaacrylate and A mixture of dipentaerythritol hexaacrylate and urethane (meth) acrylate is more preferable. Among these mixtures, a mixture containing urethane (meth) acrylate having a polymerizable unsaturated double bond of 5.5 to 9.5 mmol / g is preferable. Further, the average polymerizable unsaturated double bond concentration of the mixture is preferably 9.0 to 10.2 mmol / g.

The active energy ray-curable aqueous resin composition of the present invention comprises the acrylic resin (A) and the compound (B), and the content ratio [(B) / (A)] is 1.5 to 6 in terms of weight. It is necessary to be in the range. When the content ratio [(B) / (A)] is smaller than 1.5, the abrasion resistance and water resistance of the cured coating film are insufficient, which is not preferable. When the content ratio [(B) / (A)] is larger than 6, it is not preferable because the storage stability is insufficient. The content ratio [(B) / (A)] is preferably 1.8 to 4, more preferably 2 to 3.5.

The production method of the active energy ray-curable aqueous resin composition of the present invention is not particularly limited, and examples thereof include the following methods.

(1) The resin (A) obtained by neutralizing the carboxyl group in the acrylic resin (a) and the compound (B) are dissolved in a water-miscible organic solvent to form a solution, which is then mixed with water, Dissolution or dispersion of resin (A) in an aqueous medium containing a miscible organic solvent, and a resin solution in which resin (A) is dissolved or a resin dispersion in which resin (A) is dispersed in water, compound (B) How to disperse.

(2) The resin (A) obtained by neutralizing the carboxyl group in the acrylic resin (a) and the compound (B) are mixed with an aqueous medium containing a water-miscible organic solvent, and the resin ( A method in which the compound (B) is dispersed in the resin solution in which the resin (A) is dissolved or the resin solution (A) is dispersed.

(3) After the acrylic resin (a) and the compound (B) are dissolved in a water-miscible organic solvent to form a solution, the solution and the basic compound are mixed to form a carboxyl group in the acrylic resin (a). After obtaining the acrylic resin (A) by summing, the water-miscible organic solvent solution containing the acrylic resin (A) and the compound (B) having a polymerizable unsaturated double bond is mixed with water to obtain an aqueous solution. Dissolving or dispersing resin (A) in a medium and a method of dispersing compound (B) in a resin solution in which acrylic resin (A) is dissolved or in a resin dispersion in which resin (A) is dispersed in water.

(4) After the acrylic resin (a) and the compound (B) are dissolved in a water-miscible organic solvent to form a solution, the solution is mixed with water containing a basic compound, and the acrylic resin is mixed with the basic compound. In the resin dispersion in which the carboxyl group in (a) is neutralized and the resin (A) is dissolved or dispersed in the aqueous medium and the resin (A) is dissolved or the resin (A) is dispersed in water. A method of dispersing the compound (B) in

Among the methods described above, the methods (1) and (3) are preferable because an active energy ray-curable aqueous resin composition can be easily obtained. The acrylic resin (a) or the acrylic resin (A) and the compound (B) need not be dissolved in the water-miscible organic solvent at the same time. For example, the acrylic resin (a) or the acrylic resin (A) is dissolved in water. After dissolving in a miscible organic solvent, it may be mixed with compound (B) to disperse compound (B). Further, in the resin solution in which the acrylic resin (A) obtained by neutralizing the carboxyl group in the acrylic resin (a) is dissolved in water or the resin dispersion in which the acrylic resin (A) is dispersed in water. After obtaining the active energy ray-curable aqueous resin composition in which the compound (B) is dispersed, a part or all of the water-miscible organic solvent may be removed as necessary. Even if the active energy ray-curable aqueous resin composition or the active energy ray-curable coating material is used to remove the organic solvent, the content of the organic solvent can be reduced to 1/10 or less compared to conventional spray coating conditions. Therefore, problems such as deterioration of the working environment and air pollution caused by the volatile organic solvent are hardly caused.

The active energy ray-curable aqueous resin composition of the present invention usually contains a photo (polymerization) initiator. Various photo (polymerization) initiators can be used. For example, acetophenones, benzophenone derivatives, Michler's ketone, benzine, benzyl derivatives, benzoin derivatives, benzoin methyl ethers, α-acyloxime esters, thioxanthones, anthraquinones and various derivatives thereof such as 4-dimethylaminobenzoic acid 4-dimethylaminobenzoate, alkoxyacetophenone, benzyldimethyl ketal, benzophenone, alkyl benzoylbenzoate, bis (4-dialkylaminophenyl) ketone, benzyl, benzoin, benzoin benzoate, benzoin alkyl ether, 2-hydroxy-2- Methyl propiophenone, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl-2-hydroxy-2-pro Luketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, thioxanthone, 2,4,6-trimethylbenzoyldiphenoylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] Examples include -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one, and the like. These may be used alone or in combination of two or more. The photo (polymerization) initiator is usually oily, but the initiator is also stably dispersed in water.

The photo (polymerization) initiator is added in the range of 0.05 to 20% by weight, preferably 0.5 to 10% by weight, based on the solid content of the active energy ray-curable aqueous resin composition of the present invention. Is done.

In addition to the photo (polymerization) initiator, various photosensitizers can be used in combination. Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds.

The active energy ray-curable aqueous resin composition of the present invention comprises a compound (B) in a resin solution in which an acrylic resin (A) is dissolved in water or in a resin dispersion in which the acrylic resin (A) is dispersed in water. Is an active energy ray-curable aqueous resin composition, in which the ratio [(B) / (A)] of the acrylic resin (A) and the compound (B) is 1. It may be 5 to 6, and a part of the acrylic resin (A) may be dissolved in water, or a part of the compound (B) may be dissolved in water.

In the active energy ray-curable aqueous resin composition of the present invention, an emulsifier may be used as long as it does not impair the curing of the present invention. By using an emulsifier, the dispersion stability of the acrylic resin (A) and the compound (B) in water can be improved.

Examples of the emulsifier include nonionic emulsifiers such as polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether, anionic emulsifiers such as alkyl sulfate ester salt, alkylbenzene sulfonate salt, and polyoxyethylene alkyl ether sulfate ester salt. And cationic emulsifiers such as quaternary ammonium salts. When using an emulsifier, in order not to reduce the water resistance of the cured coating film, the amount is preferably as small as possible and more preferably not used.

There are various mechanical means for dissolving and dispersing the acrylic resin (a), the acrylic resin (A), and the compound (B) in a water-miscible organic solvent in the production of the active energy ray-curable aqueous resin composition of the present invention. The following means can be used. For example, for example, a method of mixing and dissolving and / or dispersing with a stirring blade using a turbine blade, a Max blend blade, a Hi-F mixer, or a method of mixing and dissolving and / or dispersing with a homogenizer, sonolator, disper, mixer, etc. It is done.

The active energy ray-curable coating composition of the present invention contains the active energy ray-curable resin composition of the present invention. The active energy ray-curable coating composition of the present invention is, for example, a mixture of the active energy ray-curable resin composition of the present invention, a photoinitiator, and a leveling agent, an antifoaming agent, a rheology control agent, and the like as necessary. Is obtained.

Examples of the leveling agent include polyether-modified polydimethylsiloxane, silicon-based leveling agents such as polyether-modified polydimethylsiloxane having an acryloyl group, and acrylic leveling agents. Examples of the antifoaming agent include silicon-based antifoaming agents, mineral oil-based antifoaming agents, and polymer-based antifoaming agents. Examples of the rheology control agent include an alkali swelling rheology control agent, an alkali swelling association rheology control agent, and a urethane association rheology control agent. These can be appropriately selected and used as necessary.

Furthermore, the active energy ray-curable coating composition of the present invention includes an emulsion of a compound having a polymerizable unsaturated double bond, an emulsion such as a urethane resin or an epoxy resin, a self-emulsified product, or a water-soluble resin as necessary. Etc. can also be blended.

The method for forming a cured coating film of the present invention is characterized in that after the active energy ray-curable coating material of the present invention is applied to a substrate, the applied active energy ray-curable coating material is cured by irradiation with active energy rays. . The coating is performed by, for example, a gravure coating method, a roll coating method, a spray coating method, a lip coating method, a comma coating method, a spin coating method, a dipping method, or a coating method such as a gravure printing method or a screen printing method. I can do things. Examples of the substrate include plastic, metal or metal vapor deposition surface, glass, wood, paper and the like.

Examples of the plastic include acrylic-butylene-styrene copolymer (ABS), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and cellulose triacetate (TAC). Or these composites etc. are mentioned. Examples of the metal include aluminum, stainless steel, tin, tinplate, and the like.

These base materials are base materials having a cured coating film obtained by curing the active energy ray-curable coating material applied by irradiating the active energy ray after applying the active energy ray-curable coating material of the present invention in advance. Alternatively, a base material having a cured coating film cured after applying a coating material other than the active energy ray-curable coating material of the present invention in advance and drying it if necessary,

Also, the substrate may have various shapes. For example, a thick shape, a sheet shape, or a film shape may be used. Furthermore, a design such as irregularities may be applied to the surface of the substrate.

Examples of the method for forming a cured coating film of the present invention include a forming method comprising the following steps. First, the active energy ray-curable coating material of the present invention is applied to a substrate. Thereafter, it is pre-dried. The preliminary drying is performed, for example, by allowing the coated substrate to stand in an environment of 50 to 100 ° C. for 1 to 30 minutes. Then, an active energy ray is irradiated. For example, when the base material is plastic, the preliminary drying is about 70 ° C. for about 5 minutes.

Examples of active energy rays include electron beams, ultraviolet rays, and gamma rays. The irradiation condition of the active energy ray is determined according to the composition of the active energy ray-curable coating material to be used, but it is preferable that the irradiation is usually performed so that the integrated light amount is 50 to 5000 mj / cm ^2. It is more preferable to irradiate so that it may become / cm < ² >.

In order to repair the floor of a house by the method for forming a cured coating film of the present invention, for example, after applying the active energy ray-curable coating material of the present invention to the floor and drying it with a fan, a handy type ultraviolet irradiator is used. The coating film may be cured by irradiating with ultraviolet rays.

The active energy ray-curable aqueous resin composition and the active energy ray-curable coating composition of the present invention may appropriately contain a water-miscible organic solvent depending on the coating performance such as spray coating. In addition, the total solid content of the acrylic resin (A) and the compound (B) in the active energy ray-curable aqueous resin composition or the active energy ray-curable coating of the present invention has a suitable viscosity and a coating agent. Is preferably 10 to 70% by weight, and more preferably 20 to 50% by weight.

The article in which the cured coating film of the active energy ray-curable coating material of the present invention is disposed has a cured coating film excellent in wear resistance and water resistance. The cured coating film may be disposed on the surface of the article, or may be disposed on the article as a basic coating (base coat) or an intermediate coating. Even if it is arranged on the article as a basic coating (base coat) or an intermediate coating, it can supplement the scratch resistance and water resistance of the cured coating film on the surface and extend the life of the article. Further, by forming the base coat on the base material, it is possible to prevent the base material from being damaged by the next step.

Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples and comparative examples. Unless otherwise specified, parts and% in each example are based on weight.

Synthesis Example 1 [Synthesis of acrylic resin (A)]
In a 1 liter reaction vessel equipped with a reflux condenser, a stirrer and a nitrogen inlet tube, 280 g of propylene glycol monopropyl ether was charged and stirring was started, and the temperature was raised to 120 ° C. Here, under nitrogen flow, 434 g of methyl methacrylate, 21 g of butyl methacrylate, 84 g of acrylic acid, 105 g of hydroxyethyl methacrylate, 35.0 g of Aronix M-5300 (manufactured by Toa Gosei Co., Ltd., ω-carboxypolycaprolactone acrylate) The monomer mixture and an initiator solution prepared by dissolving 12.6 g of tert-butylperoxy-2-ethylhexanoate in 20 g of propylene glycol monopropyl ether were added simultaneously over 4 hours. The polymerization reaction was further continued at the same temperature, and the reaction was terminated after 8 hours to obtain an acrylic resin (a-1) solution. The acrylic resin (a-1) has an acid value of 102 mgKOH / g, a hydroxyl value of 64 mgKOH / g, a number average molecular weight of 15,000, a weight average molecular weight of 45,000, and a glass transition temperature of 72 ° C. there were. Next, 23.3 g of triethylamine and 36.7 g of 25% aqueous ammonia were added to this solution for neutralization, and adjustment with propylene glycol monopropyl ether was performed to obtain a solution of an acrylic resin (A-1). The solution of the acrylic resin (A-1) had a nonvolatile content of 70%, and the amount of neutralized carboxyl groups was 1.10 mmol / g. The characteristic values of the acrylic resin (A-1) are shown together with the physical properties of the acrylic resin (a-1) in Table 1.

Synthesis examples 2 to 9 (same as above)
According to the method of Synthesis Example 1, an acrylic resin (A-2) solution and an acrylic resin (A-9) solution were obtained using the monomer mixture and the polymerization initiator shown in Table 1. The characteristic values of the acrylic resin (A-2) and the acrylic resin (A-9) are shown together with the physical properties of the acrylic resins (a-1) to (a-9) in Tables 1 and 2. .

Synthesis Examples 10 to 14 [Synthesis of comparative acrylic resin (a)]
According to the method of Synthesis Example 1, the acrylic resin for comparison (A′-1) and the acrylic resin for comparison (A′-5) were used in the amounts of the monomer mixture and polymerization initiator shown in Table 1. Solution was obtained. The characteristic values of the acrylic resin (a′-1) and the acrylic resin (a′-5) are also shown in Table 3.

Synthesis Example 15 [Synthesis of Compound (B)]
In a 1 liter reaction vessel equipped with a stirrer, 104 g of hexamethylene diisocyanate, 0.2 g of methoquinone and 0.2 g of dibutyltin dilaurate were charged and stirring was started, and the temperature was raised to 60 ° C. At the same temperature, 645 g of Aronix M305 (manufactured by Toa Gosei Co., Ltd., pentaerythritol triacrylate / pentaerythritol tetraacrylate, hydroxyl value 110 mgKOH / g) was added in 10 portions every 10 minutes. Further, the reaction was continued for 10 hours, and it was confirmed that the absorption of the isocyanate group at 2250 cm ⁻¹ disappeared in the infrared spectrum. The reaction was terminated, and urethane acrylate (content of polymerizable unsaturated double bond: 7.8 mmol / g) ) And pentaerythritol tetraacrylate were obtained as a compound (BB-1). The concentration of the polymerizable unsaturated double bond of the compound (BB-1) was 9.0 mmol / g.

Synthesis example 16 (same as above)
In a 1 liter reaction vessel equipped with a stirrer, 128 g of isophorone diisocyanate, 0.2 g of methoquinone, and 0.2 g of dibutyltin dilaurate were charged and stirring was started, and the temperature was raised to 60 ° C. At the same temperature, 621 g of Aronix M305 was charged in 10 portions every 10 minutes. The reaction was further continued for 10 hours, and it was confirmed that the absorption of the isocyanate group at 2250 cm ⁻¹ disappeared in the infrared spectrum, and the reaction was terminated. Then, urethane acrylate (content of polymerizable unsaturated double bond: 7.3 mmol / g) ) And pentaerythritol tetraacrylate were obtained as a compound (BB-2). The concentration of the polymerizable unsaturated double bond of the compound (BB-2) was 8.6 mmol / g.

Synthesis Example 17 [Synthesis of Compound (B)]
In a 1 liter reaction vessel equipped with a stirrer, 250 g of Aronix M404 (Toa Gosei Co., Ltd., dipentaerythritol pentaacrylate / dipentaerythritol hexaacrylate, hydroxyl value 50 mg KOH / g), Aronix M-408 (Toa Gosei Co., Ltd.) 50 g of ditrimethylolpropane tetraacrylate) and 200 g of compound (BB-1) were charged and stirred at 40 ° C. to obtain compound (B-1). The concentration of the polymerizable unsaturated double bond of the compound (B-1) was 9.5 mmol / g.

Synthesis Example 18 Same as above)
A 1 liter reaction vessel equipped with a stirrer was charged with 450 g of Aronix M404 and 50 g of compound (BB-1), and stirred at 40 ° C. to obtain compound (B-2). The concentration of the polymerizable unsaturated double bond of the compound (B-2) was 10.0 mmol / g.

Synthesis example 19 (same as above)
A 1 liter reaction vessel equipped with a stirrer was charged with 150 g of Aronix M404, 75 g of Aronix M350 (ethylene oxide-modified trimethylolpropane triacrylate manufactured by Toa Gosei Co., Ltd.) and 275 g of compound (BB-2) and stirred at 40 ° C. To obtain the compound (B-3). The concentration of the polymerizable unsaturated double bond of the compound (B-3) was 8.8 mmol / g.

Synthesis example 20 (same as above)
In a 1 liter reaction vessel equipped with a stirrer, 225 g of Aronix M402 (manufactured by Toa Gosei Co., Ltd., dipentaerythritol pentaacrylate / dipentaerythritol hexaacrylate, hydroxyl value 25 mgKOH / g), 250 g of Aronix M305 and compound (BB-1) ) Was added and stirred at 40 ° C. to obtain compound (B-4). The concentration of the polymerizable unsaturated double bond of the compound (B-4) was 10.4 mmol / g.

Synthesis Example 21 [Synthesis of Comparative Control Compound (B)]
A 1 liter reaction vessel equipped with a stirrer was charged with 75 g of Aronix M404, 150 g of Aronix M309 and 275 g of compound (BB-2), and stirred at 40 ° C. to obtain compound (b-1). The concentration of the polymerizable unsaturated double bond of the compound (b-1) was 8.4 mmol / g.

Synthesis example 22 (same as above)
In a 1 liter reaction vessel equipped with a stirrer, 75 g of Aronix M402 and 425 g of Aronix M305 were charged and stirred at 40 ° C. to obtain compound (b-2). The concentration of the polymerizable unsaturated heavy bond of the compound (b-2) was 10.6 mmol / g.

Example 1
A 1 liter reaction vessel equipped with a stirrer was charged with 97 parts of the acrylic resin (A-1) solution obtained in Synthesis Example 1 and 147 g of the urethane acrylate (B-1) obtained in Synthesis Example 8 and stirred. Then, the temperature was raised to 70 ° C. and mixed with stirring. Next, 340 g of ion-exchanged water was added in 10 portions while stirring at 40 ° C. to disperse the urethane acrylate (B-1) in the solution of the acrylic resin (A-1). Next, 10.5 g of Irgacure 500 (photopolymerization initiator manufactured by Ciba Specialty Chemicals) and 2.1 g of a silicone leveling agent (BYK, BYK-333) were added and mixed, adjusted with ion-exchanged water, and a non-volatile content of 35%. An active energy ray-curable aqueous resin composition 1 having a pH of 7.2 was prepared. The average particle diameter in the active energy ray-curable aqueous resin composition 1 was 330 nm.

In addition, the average particle diameter in the active energy ray-curable aqueous resin composition 1 was measured using NANOTRAC 150 manufactured by MICROTRAC (hereinafter the same).

PH in the active energy ray-curable aqueous resin composition 1 was measured using a PH meter D-51 manufactured by Horiba, Ltd. and an electrode type 9621C (the same applies hereinafter).

The appearance evaluation, abrasion resistance, pencil hardness, adhesion to the substrate and hot water resistance of the cured coating film of the obtained active energy ray-curable aqueous resin composition 1 were evaluated. The preparation method of the cured coating film and the evaluation method of each test are shown below.

How to make a cured coating film (test paint plate).
Spray coating was performed on a PMMA (polymethyl methacrylate) plate so that the film thickness after drying was 10 μm, and after preliminary drying at 70 ° C. for 10 minutes in a dryer, using a 80 W / cm high-pressure mercury lamp, 1000 mJ / cm ^The test coating plate was produced by irradiating with ultraviolet ray ² . In addition, for the adhesion test, the hot water adhesion test, and the water resistance test, a test coating plate based on ABS (acrylic butylene-styrene copolymer) and PC (polycarbonate) was also prepared and used. A test was also conducted.

Appearance evaluation: The appearance of the test painted plate was visually evaluated.
A: Smooth and no repelling.
○: Smooth, but slight repelling can be confirmed.
Δ: Slight irregularities are observed.
X: Large unevenness is observed.

Abrasion resistance test: Measure the haze value of the test area after rubbing the painted surface of the test painted plate with # 0000 steel wool under a load of 1Kg 100 times according to JIS-K5600-5-10 Judged by. For measuring the haze value, DIGITAL HAZE COMPUTER manufactured by Suga Test Instruments Co., Ltd. was used.
A: Less than 3.5.
○: 3.5 or more and less than 5.0.
Δ: 5.0 or more and less than 15.0
X: 15.0 or more.

Pencil hardness test: Using a high-grade pencil specified in JIS-S-6006, the coating surface of the test coating plate was examined for hardness to prevent scratches according to JIS-K-5400.

Adhesion test: In accordance with JIS-K5600-5-6, 100 mm of cuts were made on the painted surface of the test coating plate (test coating plate using PMMA, ABS and PC as the base material) with a width of 1 mm. A mass was formed, a peel test was performed using a cellophane tape, and the number of remaining grids was determined.
A: 100 on all test painted plates.
○: 80 or more on all test painted plates and 100 on one or two test painted plates.
Δ: 80 to 99 on all test painted plates.
X: 79 or less in any test coating board.

Resistance to hot water: The test coating plate (test coating plate using PMMA, ABS and PC as a base material) was immersed in warm water at 90 ° C. for 2 hours, and then the adhesion test was performed.
A: 100 on all test painted plates.
○: 80 or more on all test painted plates and 100 on one or two test painted plates.
Δ: 80 to 99 on all test painted plates.
X: 79 or less in any test coating board.

Water resistance test: The test coating plate (test coating plate using PMMA, ABS and PC as a base material) was immersed in warm water at 50 ° C. for 24 hours and 72 hours, and then the whitening state of the coated surface was visually determined.
A: No change after 72 hours on all test painted plates.
◯: All test painted plates do not change after 24 hours, but at least one test painted plate is partially whitened or blistered after 72 hours.
(Triangle | delta): Whitening or blistering is partially seen after 24 hours by all the test coating plates.
X: Whitening or blistering is observed on the entire surface after 24 hours on all test painted plates.

Examples 2 to 14 and Comparative Examples 1 to 9
According to the method of Example 1, active energy ray-curable aqueous resin compositions 2 to 14 and comparative active energy ray-curable aqueous resin compositions 1 ′ to 9 ′ were obtained with the raw material compositions shown in Table 2. . Each test was performed in the same manner as in Example 1, and the evaluation results are shown in Tables 8-11.

Footnotes in Table 1 MMA: methyl methacrylate BMA: butyl methacrylate EA: ethyl acrylate BA: butyl acrylate 2EHA: 2-ethylhexyl acrylate AA: acrylic acid MAA: methacrylic acid HEA: hydroxyethyl acrylate HEMA: hydroxyethyl methacrylate M -5300: Aronix M-5300 [Toa Gosei Co., Ltd., ω-carboxypolycaprolactone acrylate]
FM-1: Plaxel FM-1 [manufactured by Daicel Chemical Industries, Ltd., 1 mol of caprolactone adduct of hydroxyethyl methacrylate]
Initiator: Initiator solution prepared by dissolving 12.6 g of tert-butylperoxy-2-ethylhexanoate with 20 g of propylene glycol monopropyl ether

Footnotes in Tables 4 to 7 Irgacure 500: Photopolymerization initiator manufactured by Ciba Specialty Chemicals Silicone leveling agent: BYK, BYK-333

Claims (17)

1. The radical polymerizable monomer represented by the following general formula (1) is used in an amount of 2 to 15% by weight based on the weight of the resin forming component, and methyl methacrylate is used in an amount of 55 to 70% by weight based on the weight of the resin forming component. In a resin solution obtained by dissolving an acrylic resin (A) containing 0.80 to 1.29 mmol / g of neutralized carboxyl group in water or dispersing the acrylic resin (A) in water An active energy ray-curable aqueous resin composition obtained by dispersing a compound (B) having a polymerizable unsaturated double bond in a range of 8.6 to 10.5 mmol / g in a dispersed resin dispersion, the acrylic resin An active energy ray-curable aqueous resin composition, wherein the content ratio [(B) / (A)] of (A) and the compound (B) is 1.5 to 6 in terms of weight.
   

   

   (R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 2 to 8 carbon atoms, and n is an integer of 1 to 10)
2. The active energy ray-curable aqueous resin composition according to claim 1, wherein the radical polymerizable monomer represented by the general formula (1) is ε-carboxypolycaprolactone (meth) acrylate.
3. The acrylic resin (A) is obtained using ε-carboxypolycaprolactone (meth) acrylate in an amount of 3.0 to 10.0% by weight based on the weight of the resin forming component, and methyl methacrylate based on the weight of the resin forming component. 3. The active energy ray-curable aqueous resin composition according to claim 2, which is an acrylic resin obtained by using 55 to 65% by weight and containing a neutralized carboxyl group of 0.90 to 1.20 mmol / g. .
4. The active energy ray-curable aqueous resin composition according to claim 1, wherein the acrylic resin (A) is an acrylic resin containing an alkyl group having 2 to 8 carbon atoms in the side chain.
5. The active energy ray-curable aqueous resin composition according to claim 1, wherein the acrylic resin (A) is an acrylic resin having a hydroxyl value of 15 to 100 mgKOH / g.
6. In the acrylic resin (A), ε-carboxypolycaprolactone (meth) acrylate is 3 to 10% by weight based on the weight of the resin forming component, methyl methacrylate is 55 to 65% by weight based on the weight of the resin forming component, hydroxy 3 to 20% by weight of ethyl (meth) acrylate based on the weight of the resin-forming component, 1 to 25% by weight of butyl (meth) acrylate based on the weight of the resin-forming component, and acrylic acid based on the weight of the resin-forming component The active energy ray-curable aqueous resin composition according to claim 1, wherein the active energy ray-curable aqueous resin composition is obtained by using 10 to 15% by weight.
7. The active energy ray-curable aqueous resin composition according to claim 1, wherein the acrylic resin (A) is an acrylic resin containing no polymerizable unsaturated double bond.
8. The acrylic resin (A) neutralizes a carboxyl group-containing acrylic resin having a number average molecular weight of 5,000 to 30,000, a weight average molecular weight of 10,000 to 100,000, and an acid value of 75 to 150 mgKOH / g. The active energy ray-curable aqueous resin composition according to claim 1, which is an acrylic resin obtained as described above.
9. The active energy ray-curable aqueous resin composition according to claim 1, wherein the acrylic resin (A) is a resin containing 0.90 to 1.10 mmol / g of neutralized carboxyl groups.
10. The active energy ray-curable aqueous resin composition according to claim 1, wherein the compound (B) is a compound having a polymerizable unsaturated double bond of 9.0 to 10.2 mmol / g.
11. The active energy ray-curable aqueous resin composition according to claim 9, wherein the compound having a polymerizable unsaturated double bond of 9.0 to 10.2 mmol / g is a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate.
12. The compound (B) further comprises a urethane (meth) acrylate having a polymerizable unsaturated double bond of 5.5 to 9.5 mmol / g, wherein the average polymerizable unsaturated double bond of the mixture is The active energy ray-curable aqueous resin composition according to claim 11, having a concentration of 9.0 to 10.2 mmol / g.
13. The active energy ray-curable aqueous resin composition according to claim 12, wherein the urethane (meth) acrylate is a urethane (meth) acrylate which is a reaction product of a diisocyanate compound and pentaerythritol tri (meth) acrylate.
14. The active energy ray-curable aqueous resin composition according to claim 1, wherein the content ratio [(B) / (A)] of the acrylic resin (A) to the compound (B) is 2 to 3.5.
15. An active energy ray-curable coating composition comprising the active energy ray-curable aqueous resin composition according to any one of claims 1 to 14.
16. A method for forming a cured coating film, comprising: applying the active energy ray-curable coating material according to claim 15 to a substrate; and irradiating the active energy ray to cure the applied active energy ray-curable coating material.
17. An article comprising a cured coating film of the active energy ray-curable coating composition according to claim 15.