JP2003096387A - Resin composition for aqueous coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a one-component aqueous coating material resin composition which has excellent low temperature properties and, simultaneously, is curable independently of the coating environment. SOLUTION: This aqueous coating material resin composition comprises (I) a copolymer obtained by copolymerizing (a) an ethylenically unsaturated monomer having a maleimide group, (b) an ethylenically unsaturated monomer having a carbonyl group, and (c) other ethylenically unsaturated monomers; (II) an aqueous polyurethane resin having a carbonyl group or a hydrazine group; and (III) a compound having two or more same or different functional groups per molecule selected from a hydrazide group, a semicarbazide group, and a hydrazone group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-pack type resin composition for water-based coatings, which has excellent low-temperature physical properties and can be easily cured regardless of the coating environment.

[0002]

2. Description of the Related Art In recent years, in the fields of paints, inks, adhesives, etc., from the viewpoint of resource saving, environmental hygiene, pollution-free, non-hazardous material, etc., conversion from organic solvent type to aqueous type has been promoted. ing. For example, for water-based paints in the field of construction, paints that are dried at room temperature and have excellent coating performance such as water resistance, weather resistance, and stain resistance are required, and they are suitable for building applications that meet such requirements. As a resin composition for an aqueous permanent dry coating, for example, JP-A-4-249587 discloses an acrylic resin composition containing emulsion particles containing a crosslinkable carbonyl group and a dihydrazide compound.

Further, for the purpose of imparting toughness, coating film elasticity, low temperature physical properties and the like to such an acrylic resin composition, JP-A-5-339542, JP-A-7-113061 and JP-A-10-259356. In gazettes and the like, a resin composition in which an aqueous polyurethane resin is further mixed with the acrylic resin composition is proposed. The composition has excellent storability, and although the physical properties of the coating film are improved by using the aqueous polyurethane resin in combination, the crosslinking reaction may not proceed sufficiently depending on the coating environment. For example, there is a problem that the water resistance (initial water resistance) in the initial stage after coating is insufficient in coating in an environment in which evaporation of water is extremely slow, such as when the temperature is low.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems of the conventional water-based ever-drying one-pack type coating composition, and as a result, have found that the water-based polyurethane resin By using in combination with a copolymer containing a crosslinkable carbonyl group and a maleimide group that cures by irradiation of natural light,
The present invention has been completed by finding that a resin composition for a coating capable of forming a coating film excellent in water resistance, curability and the like can be obtained even in the initial stage after coating regardless of the coating environment.

Thus, according to the present invention, the ethylenically unsaturated monomer (a) having a maleimide group, the ethylenically unsaturated monomer (b) having a carbonyl group and the other ethylenically unsaturated monomer (c) are used. (I); an aqueous polyurethane resin (II) having a carbonyl group or a hydrazine group; and 2 or more of the same or different functional groups selected from a hydrazide group, a semicarbazide group and a hydrazone group per molecule. Compounds having two or more (II
The present invention provides a resin composition for an aqueous coating composition containing I).

The resin composition for aqueous paint of the present invention will be described in more detail below.

In the present specification, an acryloyl group or a methacryloyl group is referred to as a (meth) acryloyl group, an acrylate or a methacrylate is referred to as a (meth) acrylate, and acrylic acid or methacrylic acid is referred to as (meth).
Acrylic acid is represented, acrolein or methacrolein is represented by (meth) acrolein, acrylamide or methacrylamide is represented by (meth) acrylamide, and an allyl group or a methallyl group is represented by a (meth) allyl group.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Copolymer (I) The copolymer (I) comprises a maleimide group-containing ethylenically unsaturated monomer (a) and a carbonyl group-containing ethylenically unsaturated monomer (b). It is a copolymer having a maleimide group and a carbonyl group, which is obtained by copolymerizing with and other ethylenically unsaturated monomer.

The ethylenically unsaturated monomer (a) having a maleimide group is a maleimide group for three-dimensionally crosslinking a coating film formed from the resin composition of the present invention by photodimerization by irradiation with natural light. Is used to introduce the copolymer (I) into the copolymer (I).

The ethylenically unsaturated monomer (a) having a maleimide group includes a compound having an ethylenically unsaturated group and a cyclic imide group represented by the following formula (1) (hereinafter,
(Referred to simply as "imide compound").

[0011]

[Chemical 1]

Where R¹And R²Are independent hydrogen
Child or alkyl group, or R ¹And R²Are they tied
A group that forms a carbocycle together with the carbon atoms to which it is attached.
Is.

Examples of the ethylenically unsaturated group in the above imide compound include vinyl, allyl, and (meth) acryloyl groups, and the (meth) acryloyl group is particularly preferable.

Further, R ¹ and R ² in the above formula (1) are each independently an alkyl group from the viewpoint of the polymerizability of imide compounds and the copolymerizability with other unsaturated monomers. It is preferably an alkyl group having 4 or less carbon atoms, or a group which forms a carbocyclic ring together, for example, a group -CH.
_{2 CH 2 CH 2 -, -} CH 2 CH 2 CH 2 CH 2 - is - like, preferably _{-CH 2 CH 2 CH 2 CH 2} .

Specific examples of the imide compound include imide (meth) acrylates represented by the following formula (2).

[0016]

[Chemical 2]

Where R¹And R²Is as defined above, and R
³Is an alkylene group, preferably an alkylene having 1 to 6 carbon atoms.
Group, more preferably ethylene or propylene group
R ^FourIs a hydrogen atom or a methyl group, and n is 1 to 6
It is an integer, preferably 1 or 2, and more preferably
Is 1.

Preferred examples of the imide (meth) acrylate include compounds represented by the following formulas (3) and (4).

[0019]

[Chemical 3]

[0020]

[Chemical 4]

In the formula, R ⁴ and R ⁵ are each independently a hydrogen atom or a methyl group, R ⁶ and R ⁷ are each independently an alkyl group having 4 or less carbon atoms, and n is an integer of 1 to 6 is there.

The imide (meth) acrylate is a compound known per se, for example, Kiyoshi Kato et al., Journal of Organic Synthetic Chemistry, 30 (10), 897, (1972); Javier.
deAbajo et.al, Polymer, vol33 (5),
1090, (1992); acid anhydrides, amino alcohols and (meth) by the methods described in JP-A-56-53119, JP-A-1-242569 and the like.
It can be produced from acrylic acid.

The ethylenically unsaturated monomer (b) having a carbonyl group is used for introducing a carbonyl group into the copolymer (I), and the carbonyl group is the compound (III) described below. When the photo-crosslinking by the maleimide group is insufficient, it crosslinks with the functional groups therein to assist the crosslinking of the coating film by the copolymer (I).

The ethylenically unsaturated monomer (b) having a carbonyl group has at least one carbonyl group selected from an aldehyde group and a keto group and a polymerizable double bond in one molecule. Monomers are preferable, and specific examples thereof include (meth) acrolein, formyl styrene, vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone), diacetone (meth). ) Examples include acrylamide. Of these, diacetone (meth) acrylamide is preferable because of its excellent reactivity with the compound (III) described below.

Other ethylenically unsaturated monomers (copolymerized with the ethylenically unsaturated monomer (a) having a maleimide group and the ethylenically unsaturated monomer (b) having a carbonyl described above ( Examples of c) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate. , 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate and other alkyl (meth) acrylates; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and other alicyclic (meth) acrylates; benzyl (Meth) acrylate, etc. Aralkyl (meth) acrylate; 2-methoxyethyl (meth) acrylate and 2
-Alkoxyalkyl (meth) acrylates such as ethoxyethyl (meth) acrylate; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate;
Vinyl ester compounds such as perfluoroalkyl (meth) acrylate, glycidyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylonitrile, vinyl acetate and vinyl propionate; styrene; Vinyl aromatic compounds such as α-methylstyrene; Ethylenically unsaturated monocyclic compounds having an alkoxysilyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltriethoxysilane. Examples thereof include a polymer. Among these, as a preferable monomer in terms of copolymerizability, coating film physical properties, and particle stability, an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms, (meth)
Examples thereof include acrylic acid, styrene, hydroxyalkyl (meth) acrylate having an alkylene group having 2 to 3 carbon atoms, and cyclohexyl (meth) acrylate is a preferable monomer from the viewpoint of weather resistance.

The copolymer (I) can be prepared, for example, according to a general emulsion polymerization method in the presence of a surfactant as an emulsifier,
Easily prepared by copolymerizing the above-mentioned maleimide group-containing ethylenically unsaturated monomer (a), carbonyl group-containing ethylenically unsaturated monomer (b) and other ethylenically unsaturated monomer (c) Can be manufactured.

In the emulsion polymerization, the maleimide group-containing ethylenically unsaturated monomer (a), the carbonyl group-containing ethylenically unsaturated monomer (b) and other ethylenically unsaturated monomers (c) are used. ) Each component is a monomer (a),
Generally, the monomer (a) is 1 to 40% by weight, preferably 4 to 20% by weight, based on the total amount of (b) and (c).
A proportion such that the monomer (b) is in the range of 1 to 30% by weight, preferably 2 to 25% by weight, and the monomer (c) is in the range of 40 to 98% by weight, preferably 55 to 94% by weight. Can be used in.

If the proportion of the monomer (a) used is less than 1% by weight, the coating film formed from the resin composition using the copolymer (I) obtained will have a low evaporation rate of water immediately after coating. There is a possibility that the physical properties such as the initial water resistance may deteriorate, and on the other hand, when it exceeds 40% by weight, the cross-linking density of the resin composition becomes too high and the coating film tends to become brittle.

When the amount of the above monomer (b) is less than 1% by weight, the physical properties such as hardness, water resistance and stain resistance of the coating film formed from the resin composition using the copolymer (I) are deteriorated. On the other hand, if it exceeds 30% by weight, the hydrophilicity of the coating film becomes high and the water resistance after curing may decrease.

In the production of the copolymer (I), the emulsifier (surfactant) is usually used in emulsion polymerization, for example, sodium dialkylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, polyoxy. It is also possible to use anionic surfactants such as sodium ethylene alkylphenyl ether sulfate and sodium dialkyl diphenyl ether disulfonate, and nonionic surfactants such as polyoxyethylene higher alcohol ethers and polyoxyethylene alkylphenyl ethers. However, from the viewpoint of water resistance of the coating film formed using the finally obtained resin composition,
It is preferable to use radically polymerizable surfactants.
When a radically polymerizable surfactant is used as an emulsifier,
The radically polymerizable surfactant is incorporated into the copolymer as a third component.

As the radically polymerizable surfactant, for example, Japanese Patent Publication No. 46-12472 and Japanese Patent Publication No. 56-29.
657, JP-A-56-28208, JP-A-56-127697, JP-A-62-100502.
It is possible to use those known per se, such as those described in Japanese Patent Publication No. Hei 2-162287, and
Examples of commercially available products include "Latemur" (trade name, manufactured by Kao Corporation), "Eleminol" (trade name, manufactured by Sanyo Kasei Co., Ltd.), "Aqualon" (trade name, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) ), "Adeka rear soap" (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) and the like.

In the present invention, a surfactant having a polyoxyalkylene group as a main chain, a group having a radical-polymerizable double bond at one end, and an ion dissociative group at the other end is particularly preferable. Specifically, for example, a compound represented by the following formula (5) is suitable.

Z- (AO) n-Y (5) In the formula, Z is a group having a radical-polymerizable double bond,
AO is an oxyalkylene group, n is an integer of 2 or more, and Y is an ion dissociative group.

The above-mentioned radical-polymerizable double bond-containing group includes a hydrophobic group moiety such as an aromatic hydrocarbon group, an alkyl-substituted aromatic hydrocarbon group, a higher alkyl group or an alicyclic hydrocarbon group, and ( Examples thereof include those having a structure in which radical-polymerizable double bond-containing moieties such as (meth) allyl, propenyl and butenyl groups are combined.

The radical-polymerizable surfactant may be either anionic or cationic, but is preferably anionic. Therefore, as the ion dissociative group, an anion is covalently bonded to the oxyalkylene group. Then
Salt cation is ionically bound is preferable to, specifically, for example, _{-SO 3 Na, -SO 3 NH 4} , -COON
_{a, -COONH 4, -PO 3 Na} 2 , and -PO ₃ (NH _{4)
2 and the} like, among which —SO ₃ Na and —SO ₃ NH ₄ are preferable.

The repeating number n of oxyalkylene units in the polyoxyalkylene group is generally 300 or less, preferably 5 to 50, and the type of alkylene group is preferably ethylene or propylene group.

Specific examples of such radically polymerizable surfactants include compounds represented by the following formulas (6), (7) and (8).

[0038]

[Chemical 5]

[0039]

[Chemical 6]

[0040]

[Chemical 7]

In the above formula, R ⁸ and R ⁹ are linear or branched alkyl groups having 6 to 18 carbon atoms, R ¹⁰ is an alkyl group having 8 to 24 carbon atoms, and R ¹¹ is a hydrogen atom or It is a methyl group, and Y is the ion dissociative group described above.

The amount of the radically polymerizable surfactant used is such that the maleimide group-containing ethylenically unsaturated monomer (a), the carbonyl group-containing ethylenically unsaturated monomer (b) and other ethylenically unsaturated monomers are used. Although it depends on the type of the monomer (c), the type of the radical-polymerizable surfactant, and the like, generally, with respect to 100 parts by weight of the total amount of the monomers used,
It is preferably within the range of 0.1 to 5 parts by weight. If the amount of the radically polymerizable surfactant used is less than 0.1 part by weight, the stability of the emulsion obtained by emulsion polymerization using this may decrease, whereas if it exceeds 5 parts by weight, Not only is the improvement of the water resistance of the coating film in proportion to the addition amount not observed, but the water resistance tends to decrease.

From the viewpoint of improving the stability of the emulsion and the water resistance of the coating film, during the emulsion polymerization, polycarboxylic acid-based and polysulfonic acid-based anionic polymer surfactants, polyvinyl alcohol and the like are not used. An ionic polymer surfactant can also be used in combination, and the amount thereof is 0.1 parts by weight with respect to 100 parts by weight of the total amount of generally used monomers.
It is preferably within the range of 5 parts by weight.

Ethylenically unsaturated monomer having maleimide group (a), ethylenically unsaturated monomer having carbonyl group (b) and other ethylenically unsaturated monomer (c)
The emulsion polymerization of the above-mentioned monomers (a), (b),
A method in which the mixture of (c) is emulsified and dispersed in an aqueous medium using the above-described surfactant, a polymerization initiator is added, and the mixture is heated and stirred, and the monomers (a), (b), (c) are used. ) And a surfactant as described above are first used to prepare an aqueous emulsion, and the aqueous emulsion is added to an aqueous medium containing a polymerization initiator while heating and stirring. it can. At that time, a chain transfer agent may be used, if necessary, in order to control the molecular weight of the produced copolymer.

Examples of the above-mentioned polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate; peroxides such as hydrogen peroxide, benzoyl peroxide and t-butyl hydroperoxide. Uses a reducing agent such as sodium bisulfite, ascorbic acid,
You may use it as a redox type initiator. Of these, water-soluble polymerization initiators are particularly preferable. Examples of the chain transfer agent include dodecyl mercaptan,
Xanthogenic acid disulfide, diazothioether, 2
-Propanol and the like.

Copolymer (I) obtained as described above
Is generally 1000 to 1,000,000, preferably 10
It can have a number average molecular weight in the range of 5,000 to 500,000. In this specification, the number average molecular weight is a value obtained by converting the molecular weight measured by gel permeation chromatography using tetrahydrofuran as a solvent based on the molecular weight of polyethylene.

Aqueous Polyurethane Resin (II) The aqueous polyurethane resin (II) imparts elasticity and toughness to the finally formed coating film, and therefore is used for the purpose of improving the physical properties of the coating film at low temperatures. A water-based polyurethane resin having a hydrazine group and / or a carbonyl group, which is added to the resin composition, is suitable. The aqueous polyurethane resin (II) is generally dispersed in an aqueous medium in order to secure storage stability after dispersion, durability of the finally obtained coating film, and water resistance, and is generally 10 ~ 2
00 mgKOH / g, especially 10-150 mgKOH / g
It is preferable to have an acid value within the range.

Aqueous polyurethane resin having hydrazine groups
The aqueous polyurethane resin having a hydrazine group which can be used as the aqueous polyurethane resin (II) in the present invention includes, for example, a reaction of a diisocyanate compound (d), a glycol compound (e) and a glycol compound (f) having a carboxyl group. A product obtained by dispersing the obtained urethane prepolymer (A) together with the hydrazine derivative (g) in an aqueous medium (hereinafter, referred to as an aqueous polyurethane resin (II-
A)) is mentioned.

The diisocyanate compound (d) includes
An aliphatic system having two isocyanate groups in one molecule,
Compounds such as alicyclic compounds and aromatic compounds are included, and specifically, for example, 2,4-tolylene diisocyanate, 2,
6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, lysine diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexyl methane diisocyanate, 3,3 '-Dimethyl-4,4'-biphenylene diisocyanate, 3,3'
-Dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate,
Examples include 1,5-tetrahydronaphthalene diisocyanate and isophorone diisocyanate.

Examples of the glycol compound (e) include low molecular weight glycols, high molecular weight glycols, polyester polyols and polycarbonate polyols, which may be used alone or in combination of two or more. You may.

Examples of the low molecular weight glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octane diol, tricyclodecane dimethylol, hydrogenated bisphenol A, cyclohexane dimethanol, 1,6 hexane diol, etc. can be mentioned. Examples of the molecular weight glycols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

Examples of the above polyester polyols include those obtained by reacting a glycol component and a dicarboxylic acid component, and can be easily produced by a method known per se such as an esterification reaction and a transesterification reaction. Also, ε−
Polyester diols obtained by the ring-opening reaction of cyclic ester compounds such as caprolactone and their co-condensed polyesters are also included in the polyester polyols.

Examples of the above-mentioned glycol compound (f) having a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and polyesterpolyols or polycondensates thereof. An ether polyol etc. are mentioned. Further, the glycol compound (f) containing a carboxyl group may be used in combination with a hydroxycarboxylic acid such as 12-hydroxystearic acid, paraoxybenzoic acid, salicylic acid.

The urethane prepolymer (A) is prepared by reacting the above-mentioned diisocyanate compound (d), glycol compound (e) and glycol compound (f) having a carboxyl group according to a urethane-forming reaction known per se. It can be manufactured. The use ratios of these components (d), (e) and (f) at that time are not strictly limited, but the equivalent ratio of isocyanate groups to hydroxyl groups in these components is generally 1: 0.5 to 1. : 0.9
It is preferable to carry out the reaction at a ratio of 5, especially within the range of 1: 0.6 to 1: 0.9.

On the other hand, the hydrazine derivative (g) acts as a chain extender when the urethane prepolymer (A) obtained as described above is dispersed in an aqueous medium, and the above-mentioned copolymer ( It is also introduced into the aqueous polyurethane resin (II-A) as a crosslinking functional group for reacting with the carbonyl group contained in I) to cure the coating film.

Examples of the hydrazine derivative (g) include hydrazine, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-.
Examples include dihydrazine.

The dispersion of the hydrazine derivative (g) in the aqueous medium of the urethane prepolymer (A) is carried out, for example, by stirring the water containing the hydrazine derivative (g) and the neutralizing agent while stirring the urethane prepolymer (A). ) Are added all at once or gradually to mix and disperse. At this time, if necessary, other chain extenders, surfactants, etc. may be used in combination.

As other chain extenders which can be used in combination, compounds having at least two active hydrogen atoms per molecule are suitable, and examples thereof include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, Diamines such as piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; polyamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine And so on.

On the other hand, the neutralizing agent used for dispersion is not particularly limited as long as it can neutralize the carboxyl groups in the urethane prepolymer (A).
For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl2-
Amino-1-propanol, triethylamine, ammonia and the like can be mentioned. As the neutralizing agent, the carboxyl group may be previously neutralized in addition to the urethane prepolymer (A), or may be added to the aqueous medium and neutralized simultaneously with the dispersion. It is preferable to use the neutralizing agent in a ratio of usually 0.5 to 2.0 equivalents, preferably 0.7 to 1.3 equivalents, relative to 1 equivalent of the carboxyl group. Further, the formed aqueous polyurethane resin (II-A) may be desolvated by a method known per se, if necessary.

The content of hydrazine residue contained in the aqueous polyurethane resin (II-A) obtained as described above is generally 0.005 to 100 g of resin solid content.
It is preferably in the range of 0.2 mol, particularly 0.01 to 0.1 mol. When the content is less than 0.005 mol,
In some cases, a sufficient cross-linking effect cannot be obtained.
If it exceeds the molar amount, the storage stability of the coating tends to decrease.

Aqueous polyurethane resin having carbonyl group
The aqueous polyurethane resin having a carbonyl group that can be used as the aqueous polyurethane resin (II) in the present invention includes, for example, a diisocyanate compound (d), a glycol compound (e), a glycol compound (f) having a carboxyl group and a carbonyl group. With alcohol (h)
The urethane prepolymer (B) obtained by the reaction (1) is dispersed in an aqueous medium (hereinafter referred to as an aqueous polyurethane resin (II-B)).

As the diisocyanate compound (d), the glycol compound (e) and the glycol compound (f) having a carboxyl group, an aqueous polyurethane resin (II
The same as those mentioned above for -A) can be used as well.

On the other hand, the alcohol (h) having a carbonyl group is used for introducing a crosslinkable carbonyl group for reacting with the compound (III) described later to cure the coating film into the polyurethane resin skeleton. Examples include diacetone alcohol and 4-hydroxy-2butanone hydroxyacetone.

The urethane prepolymer (B) is the above-mentioned diisocyanate compound (d), glycol compound (e) and glycol compound (f) having a carbonyl group.
And an alcohol (h) having a carbonyl group according to a urethanization reaction known per se. At that time, these (d), (e),
The use ratios of the components (f) and (h) are not strictly limited, but the equivalent ratio of the isocyanate group to the hydroxyl group in these components is generally 1: 0.5 to 1: 0.95, and particularly 1: It is preferable to carry out the reaction at such a ratio as to fall within the range of 0.6 to 1: 0.9. Among them, the alcohol (h) having a carbonyl group is generally in the range of 0.01 to 0.9 equivalent, particularly 0.01 to 0.5 equivalent, and more preferably 0.01 to 0.25 equivalent, relative to 1 equivalent of the isocyanate group. It is preferably used in.

The urethane prepolymer (B) thus obtained can be dispersed in an aqueous medium by, for example, stirring the water containing the chain extender and the neutralizing agent and once adding the urethane prepolymer (B). In addition to the above, a method of mixing and dispersing by gradually adding it may be mentioned. At this time, a surfactant may be used together if necessary. As the chain extender, the same hydrazine derivative (g) as described above or the other chain extender described above can be used. The formed aqueous polyurethane resin (II-B) may be desolvated if necessary.

The content of carbonyl groups contained in the aqueous polyurethane resin (II-B) obtained as described above is
Generally, 0.005 to 0. 5 per 100 grams of resin solids.
It is preferable that the amount is 3 mol, preferably 0.01 to 0.2 mol. If the content is less than 0.005 mol, a sufficient crosslinking effect cannot be obtained. On the other hand, if the content exceeds 0.3 mol, physical properties such as water resistance and storage stability of the paint are deteriorated due to a decrease in molecular weight of the urethane polymer (B). Tends to get worse.

In the present invention, the aqueous polyurethane resin (I
As the aqueous polyurethane resin having a carbonyl group which can be used as I), a diisocyanate compound (d), a glycol compound (e), a glycol compound (f) having a carboxyl group and a hydroxyl group-containing ethylenically unsaturated monomer are also included. Obtained by copolymerizing an unsaturated group-containing urethane prepolymer (C) obtained by the reaction (i) and a monomer mixture containing an ethylenically unsaturated monomer (j) having a carbonyl group in an aqueous medium. (Hereinafter, referred to as an aqueous polyurethane resin (II-C)).

As the diisocyanate compound (d), the glycol compound (e) and the glycol compound (f) having a carboxyl group, an aqueous polyurethane resin (II
The same as those mentioned above for -A) can be used as well.

The hydroxyl group-containing ethylenically unsaturated monomer (i) is used for introducing an unsaturated group into the polyurethane resin skeleton, and examples thereof include hydroxyethyl (meth) acrylate and hydroxypropyl (meth). ) Acrylate, hydroxybutyl (meth) acrylate, polyethylene glycol-mono (meth) acrylate, polyethylene glycol-mono (meth) acrylate, polypropylene glycol-mono (meth) acrylate, hydroxyethyl (meth) acrylate ε-.
(Meth) acrylates such as caprolactone polyadducts, hydroxyethyl (meth) acrylate β-methyl-δ-valerolactone polyadducts, glycerol mono (meth) acrylate, glycerol di (meth) acrylate; allyl alcohol, glycerol mono Allyl compounds such as allyl ether and glycerol diallyl ether; and their alkylene oxide adducts having 2 to 4 carbon atoms (the number of moles of alkylene oxide added is usually 0 to 30 mol, preferably 20 to 30 mol). .

Unsaturated group-containing urethane prepolymer (C)
In addition to the diisocyanate compound (d), the glycol compound (e), the glycol compound (f) having a carboxyl group and the hydroxyl group-containing ethylenically unsaturated monomer (i), an excess isocyanate group is blocked. If necessary, 1 to adjust the concentration of unsaturated groups
You may use a polyhydric alcohol together.

These (d), (e), (f) and (i)
The ratio of the components used is not strictly limited, but the equivalent ratio of the isocyanate groups to the hydroxyl groups in these components is generally 1: 1 to 1: 1.5, preferably 1: 1 to 1: 1.
The reaction can be carried out at a ratio within the range of 1.3. Of these, the hydroxyl group-containing ethylenically unsaturated monomer (i) is generally 0.1.
It is preferable to use it in the range of 01 to 1 equivalent, particularly 0.02 to 0.8 equivalent.

Unsaturated group-containing urethane prepolymer (C)
Is, for example, by reacting the above-mentioned diisocyanate compound (d), glycol compound (e), carboxyl group-containing glycol compound (f) and hydroxyl group-containing ethylenically unsaturated monomer (i) at once, Alternatively, in multiple stages, for example, first, the diisocyanate compound (d), a part of the glycol compound (e) and the carboxyl group-containing glycol compound (f) are reacted to synthesize a prepolymer at the isocyanate terminal, and then the glycol compound (e ) And the hydroxyl group-containing ethylenically unsaturated monomer (i) are reacted with each other. At that time, in order to accelerate this reaction, as used in a usual urethanization reaction,
Amine-based catalysts such as triethylamine, N-ethylmorpholine and triethylenediamine, and tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate may be used, and the ethylenically unsaturated compound is polymerized during the urethanization reaction. To prevent hydroquinone,
A polymerization inhibitor such as hydroquinone monomethyl ether or p-benzoquinone can be used.

The unsaturated group-containing urethane prepolymer (C) is then copolymerized with the carbonyl group-containing ethylenically unsaturated monomer (j) in an aqueous medium by a known method. The ethylenically unsaturated monomer (j) having a carbonyl group is, among the ethylenically unsaturated monomers (b) having a carbonyl group described above as a monomer component constituting the copolymer (I). Can be appropriately selected and used.

For the copolymerization of the urethane prepolymer (C) and the unsaturated monomer (j), for example, the unsaturated group-containing urethane prepolymer (C) is mixed with the carbonyl group-containing ethylenically unsaturated monomer (j). And a method of heating and stirring while dropping a polymerization initiator while stirring with an aqueous medium containing a neutralizing agent; an unsaturated group-containing urethane prepolymer (C) and a carbonyl group-containing ethylenically unsaturated monomer (j It can be carried out by a method in which an emulsifier is added to the mixture of 1) to prepare an aqueous emulsion, and the aqueous emulsion is heated and stirred while being added to an aqueous medium containing a polymerization initiator. In this copolymerization,
If necessary, other ethylenically unsaturated monomers may be used together.

Examples of the polymerization initiator that can be used in the above copolymerization include azo initiators such as azoisovaleronitrile; peroxides such as t-butyl hydroperoxide; and ammonium persulfate. Examples of such persulfate are known per se, and a reducing agent such as sodium formaldehyde sulfoxylate may be used together for the purpose of lowering the polymerization temperature.

The content of carbonyl group contained in the aqueous polyurethane resin (II-C) obtained as described above is
Although not strictly limited, resin solid content 100 g
In general, 0.005 to 0.3 mol, especially 0.01 to
A range of 0.2 mol is preferred. The content is 0.00
If it is less than 5 mols, a sufficient crosslinking effect cannot be obtained, and if it exceeds 0.3 mols, the storage stability of the coating composition tends to deteriorate.

Compound (III) The resin composition of the present invention comprises, as a crosslinking agent which reacts with the carbonyl group contained in the copolymer (I) and / or the aqueous polyurethane resin (II-B) or (II-C), It contains a compound (III) having two or more functional groups of at least one selected from a hydrazide group, a semicarbazide group and a hydrazone group per molecule.

Examples of the compound (III-1) having two or more hydrazide groups per molecule include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide,
Of saturated aliphatic carboxylic acid dihydrazides having 2 to 18 carbon atoms such as glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide; monoolefinic unsaturated dicarboxylic acids such as maleic acid dihydrazide, fumaric acid dihydrazide and itaconic acid dihydrazide Dihydrazide; phthalic acid, terephthalic acid or isophthalic acid dihydrazide, and dihydrazide, trihydrazide or tetrahydrazide of pyromellitic acid; nitrilotriacetic acid trihydrazide, citric acid trihydrazide, 1,
2,4-benzenetrihydrazide; ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydrazide; a low polymer having a carboxylic acid lower alkyl ester group is referred to as hydrazine or hydrazine hydrate. Examples thereof include polyhydrazides (see Japanese Patent Publication No. 52-22878) obtained by reaction.

If the hydrazide compound is too hydrophobic, it may be difficult to disperse it in water and a uniform crosslinked coating film may not be obtained. Therefore, a relatively low molecular weight compound having appropriate hydrophilicity is used. In the above examples, dihydrazides of dicarboxylic acids such as adipic acid dihydrazide and succinic acid dihydrazide are preferable.

Examples of the compound (III-2) having two or more semicarbazide groups per molecule include dihydrazide carbonate, bissemicarbazide; diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and polyisocyanate compounds derived therefrom with N. , N-N-substituted hydrazines such as N-dimethylhydrazine and polyfunctional semicarbazides obtained by excessively reacting the above-mentioned hydrazides; hydrophilicity of the polyisocyanate compound, polyether, polyols, polyethylene glycol monoalkyl ethers, etc. Aqueous polyfunctional semicarbazide obtained by excessively reacting the above-exemplified dihydrazide with the isocyanate group in the reaction product with a reactive group-containing active hydrogen compound; and the polyfunctional semicarbazide and the aqueous polyfunctional semicarbazide. Mixture (JP-A 8-151358
JP-A-8-283377, JP-A-8-2
No. 45878) and the like.

As the compound (III-3) having two or more hydrazone groups per molecule, bisacetyldihydrazone can be preferably used.

The compounds (III-1) and (III-
2) and (III-3) can be used alone or in combination of two or more kinds.

Aqueous Paint Resin Composition The aqueous paint resin composition of the present invention comprises the above-mentioned copolymer (I), aqueous polyurethane resin (II) and compound (II).
It contains I) as an essential component and is dissolved or dispersed in an aqueous medium.

The mixing ratio of each of the above components in the resin composition of the present invention is not strictly limited and can be changed depending on the application of the resin composition and the like. The aqueous polyurethane resin (II) is generally 95/5 to 10/90, preferably 90/10 to 10 in terms of solid content weight ratio of copolymer (I) / aqueous polyurethane resin (II).
It can be in the range of 50/50. In addition, the compound (III) generally contains 0.01 to 2 mol of the functional group in the compound (III) per 1 mol of the total amount of carbonyl groups contained in the copolymer (I) and the aqueous polyurethane resin (II). , And preferably in a ratio of 0.1 to 1.5 mol. The above copolymer (I)
/ Water-based polyurethane resin (II) solid content weight ratio is 95 /
When it exceeds 5, the flexibility of the formed coating film becomes insufficient, while when it is less than 10/90, the weather resistance and water resistance of the coating film may be inferior. When the proportion of the functional group in the compound (III) is less than 0.01 mol, the coating film formed from the resin composition of the present invention has insufficient physical properties such as hardness, water resistance and stain resistance. If it exceeds 2 mol, the storage stability of the resin composition of the present invention tends to decrease.

The resin composition of the present invention preferably further contains an acrylic copolymer (IV) having a carbonyl group in order to improve the curing inside the coating film. The acrylic copolymer (IV) having a carbonyl group is, for example, a polymerizable compound containing the above-mentioned polymerizable unsaturated monomer (a) having a carbonyl group as a monomer component constituting the copolymer (I). It can be obtained by emulsion polymerization of an unsaturated monomer in the presence of an emulsifier.

Acrylic copolymer having the carbonyl group
(IV) is generally 5 to 5 parts by weight based on 100 parts by weight of the total solid content of the copolymer (I) and the aqueous polyurethane resin (II).
It can be used in an amount of 150 parts by weight, preferably 5 to 100 parts by weight, more preferably 5 to 80 parts by weight. If the amount of the copolymer (IV) used is less than 5 parts by weight, the effect of addition, that is, the internal curing of the coating film may be insufficient,
On the other hand, if it exceeds 150 parts by weight, the initial water resistance in coating in an environment where the water evaporation is slow, the photocuring effect of the copolymer (I) becomes difficult to obtain, and the elasticity of the coating film also decreases. Tend to do.

Further, the resin composition of the present invention contains an organosilicate compound, if necessary, in order to further improve the stain resistance of the coating film when it is used as a single-layer finish or multi-layer finish topcoat paint. Can be included. Examples of the organosilicate compound that can be used for such a purpose include compounds represented by the following formula (9).

[0088]

[Chemical 8]

In the formula, R ¹² is the same or different and is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

Examples of the above-mentioned hydrocarbon group include methyl, ethyl, n-propyl, iso-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, iso-pentyl, n-hexyl, i. Alkyl groups such as -hexyl and n-octyl, and aryl groups such as phenyl are preferable.

As specific examples of the organosilicate compound of the above formula (9), for example, tetrahydroxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane,
Examples thereof include tetraphenoxysilane and dimethoxydiethoxysilane. These may be used alone or in combination of two or more.

A branched or linear condensate of the above organosilicate compounds can also be used, and the degree of condensation is usually in the range of 2 to 100.

Further, for the reason that the solubility in water is good, as the organosilicate compound, a polyalkylene glycol compound is partially reacted with the alkoxy group or hydroxyl group in the above organosilicate compound and / or its condensate. Modified organosilicate compounds described above can be used particularly preferably.

Examples of the polyalkylene glycol compound as a modifier include those represented by the following general formula (10).

R ¹³ O- (R ¹⁴ O) n-H (10) In the formula, R ¹³ is a hydrogen atom, an alkyl group or an aryl group, R ¹⁴ is an alkylene group having 2 to 4 carbon atoms, and n Is 2
-60.

Specific examples of such a compound include:
For example, polyalkylene glycol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol; methoxy polyethylene glycol,
Alkoxy polyalkylene glycols such as ethoxy polyethylene glycol, ethoxy polypropylene glycol and ethoxy polybutylene glycol; polyoxyalkylene nonyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Oxyethylene nonyl phenyl ether is preferred.

The content of the above organosilicate compound in the resin composition of the present invention is generally 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the resin solid content in the composition. Can be within.

In the resin composition for water-based coating composition of the present invention, in order to promote photocuring in the copolymer (I),
In some cases, a compound having two or more (meth) acryloyl groups such as alkylene glycol di (meth) acrylate, polyalkylene glycol poly (meth) acrylate, urethane (meth) acrylate and polyester (meth) acrylate may be contained. it can.

Further, if necessary, color pigments, extender pigments, surfactants, dispersants, defoamers, thickeners, film-forming aids, preservatives, antifreezing agents and the like can be added. .

Since the resin composition for water-based coating composition of the present invention is easily cured at room temperature and further accelerated by the irradiation of natural light, it is particularly suitable for coating the interior / exterior of buildings, bridges, ships, etc. Suitable for paint applications. Further, the resin composition of the present invention can be used as a single-layer top coat paint because it forms a coating film with excellent performance even in a single-layer finish, but as a top coat paint for multiple-layer finish, or undercoat adjustment It can also be used as an undercoat paint.

When the resin composition of the present invention contains a pigment, the content of the pigment is such that the resin composition does not substantially interfere with the photo-curing of the resin composition and retains an appropriate hiding property as an enamel coating. The pigment volume concentration in the composition (hereinafter referred to as "P
It is desirable to use it within the range of 10 to 70%.

Here, the "pigment volume concentration (PVC)" is the volume ratio of the pigment content in the solid content of the mixture of the resin and the pigment in the resin composition, and is a value calculated by the following formula.

[0103]

[Equation 1]

The above PVC is in the range of 10 to 60%, preferably 15 to 55% when the resin composition of the present invention is used as a top coating composition, and 30 to 70% when it is used as an undercoat composition. %, Preferably 30-66
It can be within the range of%.

[0105]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, "part" means a weight part.

A copolymer having a maleimide group and a carbonyl group
Production of Polymer Production Example 1 Imide acrylate represented by the following formula (11) (hereinafter,
10 parts of imide acrylate), 5 parts of diacetone acrylamide, 50 parts of n-butyl methacrylate
Parts, 20 parts of methyl methacrylate, 14 parts of n-butyl acrylate, and 1 part of methacrylic acid are mixed, and 100 parts of deionized water and 0.5 part of "AQUALON HS10" (Note 1) are added to the mixture, and the homogenate is rotated. A monomer emulsion was prepared using a mixer.

[0107]

[Chemical 9]

On the other hand, 45 parts of deionized water, "Aqualon H
After replacing the inside of the flask containing 0.5 parts of S10 "(Note 1) with nitrogen, heat the temperature to 80 ° C, and heat the internal liquid to a temperature of 80 ° C.
While maintaining the above, 1 part of ammonium persulfate and 2% by weight of the above monomer emulsion were added thereto, and 15 minutes after the addition, the remaining monomer emulsion was added dropwise over 2 hours. It was aged for 2 hours as it was. After aging, the mixture was cooled and 3 parts of 10 wt% ammonia water was added dropwise as a neutralizing agent to obtain an emulsion type copolymer aqueous dispersion (A-1). (Note 1) "Aqualon HS10": manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., a radically polymerizable surfactant represented by the following formula (12).

[0109]

[Chemical 10]

Aqueous polyurethane resin having hydrazine groups
Production of fat Production example 2 Methyl ethyl ketone 26 was added to a 2-liter four-necked flask.
8.3 parts, polypropylene glycol (molecular weight about 2,0
00) 260 parts, 2,2'-dimethylolpropionic acid 26.5 parts and isophorone diisocyanate 116 parts were charged, dry nitrogen was enclosed while stirring, and the mixture was heated to 70 ° C. After the internal liquid was kept at a temperature of 70 ° C. for 1 hour, the temperature was further raised to 80 ° C. and the temperature was maintained at 80 ° C. for 6 hours. Then, it cooled to 30 degreeC and obtained the urethane prepolymer solution. On the other hand, 7.8 parts of an 80% hydrazine aqueous solution and an aqueous solution of 21 parts of triethylamine dissolved in 764 parts of deionized water were charged in advance in another 2 liter four-necked flask, and the above urethane prepolymer was stirred while stirring. 670.8 parts of the polymer solution was gradually poured to carry out water dispersion. Then, the obtained aqueous dispersion was heated to 50 ° C., the solvent was removed by decompression, and the concentration was adjusted by adding deionized water to obtain a solid content of 35.4% and an acid value of 34 mgKOH / g.
A semi-transparent aqueous polyurethane resin (U-1) was obtained.

Aqueous polyurethane resin having carbonyl group
Production of fat Production example 3 Methyl ethyl ketone 39 was added to a 2-liter four-necked flask.
6 parts, polypropylene glycol (molecular weight about 100
0) 333.3 parts, 2,2'-dimethylolpropionic acid 67 parts, 1,6-hexanediol 19.7 parts and isophorone diisocyanate 296 parts were charged, and dry nitrogen was added while stirring and up to 70 ° C. Heated. After the internal liquid was kept at a temperature of 70 ° C. for 1 hour, the temperature was further raised to 80 ° C. and maintained at 80 ° C. for 2 hours, then 19.3 parts of diacetone alcohol was added dropwise over about 30 minutes, and then further 4
The temperature was maintained at 80 ° C for an hour. Then, it cooled to 30 degreeC and obtained the urethane polymer solution. On the other hand, in a separate 2 liter four-necked flask, triethylamine 1
An aqueous solution in which 1.8 parts of piperazine and 10.0 parts of piperazine were dissolved in 868 parts of deionized water was charged, and 565.6 parts of the above urethane polymer solution was gradually poured into the solution while stirring to disperse it in water. Then, the temperature of the obtained aqueous dispersion was raised to 50 ° C., the solvent was removed under reduced pressure, deionized water was added to adjust the concentration, solid content 30.2%, acid value 36 mg KO.
A translucent aqueous polyurethane resin (U-2) of H / g was obtained. Production Example 4 "Kyowanol D" was added to a 2-liter 4-necked flask.
(Note 2) 860 parts, polypropylene glycol (molecular weight about 1,000) 2,000 parts, polycaprolactone diol (molecular weight about 530) 740 parts and 2,2'-dimethylolpropionic acid 210 parts were charged and dried with stirring. It was filled with nitrogen and heated to 100 ° C. Temperature of internal liquid 1
Isophorone diisocyanate 1, while maintaining at 00 ℃
110 parts was dropped. After completion of dropping, stir at 100 ° C for approx. 1
After a lapse of time, sampling was performed, and when the concentration of the isocyanate group reached 0.41 meq / g, 195 parts of hydroxyethyl methacrylate and 37 parts of n-butyl alcohol were added, and the mixture was stirred at 100 ° C. for 2 hours and then cooled to 40 ° C., 162 parts of triethylamine and 9,000 parts of deionized water were added to obtain an unsaturated urethane prepolymer aqueous dispersion having a solid content of 30%. On the other hand, 100 parts of this unsaturated urethane prepolymer aqueous dispersion and 3 parts of diacetone acrylamide were placed in another 4-neck flask and the temperature was raised to 60 ° C., while stirring this, 0.2 parts of t-butyl hydroperoxide. Was dissolved in 5 parts of deionized water and a solution of 0.2 parts of sodium formaldehyde sulfoxylate in 5 parts of deionized water were added separately dropwise over 1 hour, and the solution was further added at 60 ° C. for 30 minutes.
After aging for minutes, it was cooled, solid content 30%, acid value 20 mg KO
H / g aqueous polyurethane resin (U-3) was obtained. (Note 2) "Kyowanol D": manufactured by Kyowa Hakko Co., Ltd., production of acrylic copolymer having texanol isobutyl ether carbonyl group Production Example 5 36 parts of deionized water and 0.36 part of "Newcol 707SF" (Note 3) After replacing the flask with nitrogen with nitrogen,
Warmed to ° C. 0.1 part of ammonium persulfate was added while maintaining the inner liquid at 80 ° C., and then the following monomer emulsion was added dropwise over 3 hours.

Deionized water 52.4 parts Diacetone acrylamide 5 parts Acrylic acid 0.5 parts Styrene 15 parts Methyl methacrylate 37 parts 2-Ethylhexyl acrylate 16 parts n-Butyl acrylate 26.5 parts "Newcol 707SF" (Note 3) 9.6 parts Ammonium persulfate 0.2 parts 30 minutes to 30 minutes after the completion of dropping, a solution of 0.1 part ammonium persulfate in 1 part deionized water is added dropwise.
Further, it was kept at 80 ° C. for 2 hours to obtain an emulsion type copolymer aqueous dispersion (B-1). (Note 3) "Newcol 707SF": manufactured by Nippon Emulsifier Co., Ltd.
An anionic surfactant having a polyoxyethylene chain,
Manufacture of Organosilicate Modified with 30% Nonvolatile Content Production Example 6 “Ethyl silicate 48” (Note 4) 5 was added to a reaction vessel equipped with a stirrer, a thermometer, a reflux tube, a nitrogen inlet tube and a water separator.
00 parts, "Newcol 568" (Note 5) 324.5 parts and "Scat 24" (Note 6) 0.082 parts were charged and heated to 120 ° C while stirring in a nitrogen atmosphere, and then to 160 ° C over 4 hours. The temperature was raised and the temperature was maintained for 1 hour. At that time, 25 parts of ethanol and the like which was evaporated was distilled off by a water separator to obtain 800 parts of modified organosilicate. (Note 4) "Ethyl silicate 48": Tama Chemical Co., Ltd., ethyl silicate condensate (Note 5) "Newcol 568": Nippon Emulsifier, polyoxyethylene nonyl phenyl ether (Note 6) "Scat 24": Sansha Machine Manufactured by Synthetic Co., Ltd., production of tin-based catalyst pigment dispersion paste Production Example 7 The components shown below were sequentially charged into a container, and stirring was continued for 30 minutes with a disper until uniform, to obtain a pigment dispersion paste. Pigment dispersion paste composition Clean water 8.0 parts Ethylene glycol 2.0 parts "Slaoff 72" (Note 7) 0.1 parts "Nopcosanto K" (Note 8) 0.3 parts "Titanium White JR-600A" (Note 9) ) 24.6 parts "SN Deformer A-63" (Note 10) 0.4 parts (Note 7): "Suraoff 72N": Takeda Chemicals, preservative (Note 8): "Nopco Santo K": San Nopco, Pigment Dispersant (Note 9): "Titanium White JR600-A": Teika Titanium White (Note 10): "SN Deformer A-63": San Nopco, Defoaming Agent Premix Paint Preparation Examples 8-15 To the pigment-dispersed paste, the components shown in the composition of Table 1 below were sequentially added, and stirred with a disper until uniform,
Premix paints (T-1) to (T-8) were obtained.

[0113]

[Table 1]

Note 10) "Adecan UH-438": made by Adeka, thickener Note 11) PVC: pigment volume concentration Volume ratio of pigment content to solid mixture of resin and pigment Preparation of paint Examples 1 to 8 And Comparative Examples 1 to 4 100 parts of each of the premix paints obtained in Production Examples 8 to 15 were combined with a crosslinking agent in the combinations shown in Table 2 below to obtain each coating composition.

Preparation of test coated plate "Multi-tile concrete primer EPO" (Kansai Paint Co., Ltd., epoxy-based primer) was coated on a slate plate of 70 × 150 × 5 mm, and on the next day, each paint shown in Table 2 below was treated with tap water. After diluting to about 70 KU, it was coated with a brush so that the coating amount was about 0.15 kg / m ² .

Each paint and each test coated plate were evaluated according to the criteria described below, and the results are shown in Table 2.

[0117]

[Table 2]

(Note 13) "SX-601": Asahi Kasei Corporation, semicarbazide functional group-containing compound, solid content 45
%, - NHCO-NHNH ₂ content 4.8 mmol /
g Resin (Note 14) 20% bisacetyldihydrazone: methyl ethyl ketone solution evaluation test Paint storability test Each of the paints obtained above was stored in a thermostatic chamber at 50 ° C for one month, and then the paint condition was visually evaluated. ⊚: Almost unchanged compared to the initial stage, and good. ◯: A slight increase in viscosity is observed, but there is no practical problem. Δ: Thickening was remarkable and not practical, but gelation was not achieved. X: Gelled.

Initial Water Resistance Test (Outdoor) Each test coated plate coated with each of the above-obtained paints was placed in a cold greenhouse at 5 ° C. for 30 minutes immediately after coating, and then outdoors on a cloudy day (in the shade on the north side of the building). It was left for about 1 hour at a temperature of 8 to 10 ° C. and 65 to 75% RH. Then, each test plate was submerged in water for 10 minutes, and the appearance of the coating film was visually evaluated. ⊚: The coating film is good with no abnormalities. ◯: Some glossiness or blistering is observed, but there is no problem in practical use. Δ: Large or large blisters or partial elution of coating film. X: The coating film is significantly eluted.

Initial Water Resistance Test (Indoor) Each test coated plate coated with each of the above-obtained paints was placed in a cold greenhouse at 10 ° C. for 30 minutes immediately after coating, and then placed in a bright room without direct sunlight but with natural light. Left for about 1 hour (2
0 ° C., 60 to 70% RH). Then, each test coated plate was submerged in water for 10 minutes, and the appearance of the coating film was visually evaluated. ⊚: The coating film is good with no abnormalities. ◯: Some glossiness or blistering is observed, but there is no problem in practical use. Δ: Large or large blisters or partial elution of coating film. X: The coating film is significantly eluted.

Elongation of coating film at low temperature Each coating material was coated on a release paper with a 150 μm applicator and dried in a constant temperature and humidity chamber at 20 ° C. and 65% RH for 28 days, and then the coating film was peeled off from the release paper to obtain a film thickness. A coating film piece having a thickness of about 40 μm was obtained. The elongation of this coating film piece was measured at a pulling speed of 20 mm / min under a condition of -10 ° C. ○: 20% or more △: 5% or more and less than 20% ×: less than 5% Outdoor pollution test After applying a primer and each paint to a slate plate of 90 × 300 × 5 mm in the same manner as the above test plate, each day next The paint was applied in the same manner, the paint was applied again, and dried at room temperature for 7 days to obtain a test coated plate. One of them was used for exposure and the other was reserved. The test coated plate for exposure was attached to the exposed plate of 30 degrees on the south side in the Kansai Paint Tokyo Works, and taken out after 3 months, and the color difference ΔE with the reserve test plate was measured. ⊚: ΔE is less than 3 ○: ΔE is 3 or more and less than 5 Δ: ΔE is 5 or more and less than 7 ×: ΔE is 7 or more

[0122]

INDUSTRIAL APPLICABILITY The resin composition for water-based paints of the present invention provides elasticity and flexibility to the coating film by the polyurethane resin component, so that it is possible to secure low-temperature physical properties and the like, and further to add a carbonyl group and a maleimide group. Even when the coating drying conditions are such that the evaporation of water is slow (for example, cloudy, low temperature, indoors), the use of a copolymer with a Since curing proceeds, physical properties in the initial stage after coating, such as water resistance and stain resistance in the initial stage after coating, can be improved.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masami Sugishima             Seki, 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture             West Paint Co., Ltd. (72) Inventor Nobuge Numa             Seki, 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture             West Paint Co., Ltd. (72) Inventor Mitsuhase Hasegawa             1 East of Funami-cho, Minato-ku, Nagoya City, Aichi Prefecture             Inside of Polymer Materials Research Laboratories (72) Inventor Hiroshi Inukai             1 East of Funami-cho, Minato-ku, Nagoya City, Aichi Prefecture             Inside of Polymer Materials Research Laboratories F-term (reference) 4J038 CC061 CC062 CE051 CE052                       CF062 CF071 CF072 CF091                       CF092 CG031 CG032 CG141                       CG142 CG161 CG162 CG191                       CG192 CH031 CH032 CH041                       CH042 CH071 CH072 CH121                       CH122 CH131 CH132 CH201                       CH202 DG051 DG052 DG111                       DG112 DG131 DG132 DG321                       DG322 DL021 DL022 DL111                       DL112 DL121 DL122 GA02                       GA08 JB17 KA03 LA02 MA12                       NA04 NA05

Claims (8)

[Claims] 1. An ethylenically unsaturated monomer (a) having a maleimide group, an ethylenically unsaturated monomer (b) having a carbonyl group and another ethylenically unsaturated monomer (c).
Copolymer (I) obtained by copolymerization of water-based polyurethane resin having carbonyl group or hydrazine group (I
I); and a resin composition for an aqueous coating composition containing a compound (III) having two or more functional groups selected from a hydrazide group, a semicarbazide group and a hydrazone group in one molecule or more. 2. A urethane prepolymer (A) obtained by a reaction of an aqueous polyurethane resin (II) with a diisocyanate compound (d), a glycol compound (e) and a glycol compound (f) having a carboxyl group, and a hydrazine derivative (g). ) And dispersed in an aqueous medium.
The resin composition for water-based paints according to 1. 3. A urethane prepolymer obtained by reacting an aqueous polyurethane resin (II) with a diisocyanate compound (d), a glycol compound (e), a glycol compound (f) having a carboxyl group and an alcohol (h) having a carbonyl group. The resin composition for an aqueous coating composition according to claim 1, wherein the polymer (B) is dispersed in an aqueous medium. 4. A reaction of an aqueous polyurethane resin (II) with a diisocyanate compound (d), a glycol compound (e), a glycol compound having a carboxyl group (f) and a hydroxyl group-containing ethylenically unsaturated monomer (i). An unsaturated group-containing urethane prepolymer (C) obtained by
The resin composition for an aqueous coating composition according to claim 1, which is obtained by copolymerizing a monomer mixture containing an ethylenically unsaturated monomer (j) having a carbonyl group in an aqueous medium. 5. The blending ratio of the copolymer (I) and the aqueous polyurethane resin (II) is 95/5 to 10/90 in terms of solid content weight ratio.
The resin composition for water-based paints according to any one of claims 1 to 4, which is within the range. 6. The resin composition for an aqueous coating composition according to any one of claims 1 to 5, which further contains a copolymer (IV) having a carbonyl group. 7. A polyalkylene glycol compound is added to the organosilicate and / or its condensate in an amount of 0.001 to 0.5 with respect to 1 mol of the alkoxy group or hydroxyl group.
The resin composition for aqueous paints according to any one of claims 1 to 6, which further contains a modified organosilicate compound obtained by a molar reaction. 8. A water-based coating composition containing the resin composition for water-based coating according to any one of claims 1 to 7.