JPH02214755A - Resin composition for water paint - Google Patents

Abstract

PURPOSE:To provide the subject composition containing a specified aqueous resin prepared by reacting a fluorine-containing copolymer with ethylenic unsaturated monomers and a curing agent and capable of providing a coating film excellent in long-term weather resistance, durability, corrosive properties and coating-film appearance such as high gloss. CONSTITUTION:An objective composition containing (A) an aqueous resin prepared by reacting (i) a fluorine-containing copolymer having reactive C-C double bonds in the molecule with (ii) ethylenic unsaturated monomers containing an amino group-containing ethylenic unsaturated monomer (e.g. aminoaryl) and then neutralizing at least a part of amino groups in the resultant fluorine- containing copolymer with 5-150, preferably 30-150 amine number and 10-300, preferably 30-150 hydroxyl number using an acidic compound and (B) a curing agent (preferably blocked isocyanate compound or aminoplast resin) as the main components.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a t! ! ! The present invention relates to a resin composition for a cationic water-based paint that provides a film.

<Prior art and its problems to be solved> There are two types of resin compositions for water-based paints: anionic and cationic, and the latter has several times better corrosion resistance than the former when applied to electrodeposition coatings. Since then, it has become widely adopted.

Representative examples of such cationic water-based coating resins include epoxy resins, acrylate resins, epoxy acrylate resins, and polybutadiene resins.

Incidentally, in recent years, there has been a strong demand for paints with a long coating life, that is, good long-term weather resistance, from the viewpoint of resource and energy conservation, and the resin systems described above have not been able to fully meet these demands.

On the other hand, as a paint with good long-term weather resistance, JP-A-57-341
Organic solvent-soluble fluororesin paints, typified by the resin described in Publication No. 07, are attracting attention.

However, since such organic solvent-based fluororesin paints use large amounts of organic solvents, they pose problems in terms of air pollution and other issues, as well as problems in terms of resource conservation. It had the disadvantage of being inferior to organic solvent-based acrylic resin paints.

In view of the current situation, the inventors of the present invention have developed a technology that takes advantage of the long-term weather resistance of fluororesin, while also making it dilutable with water, making it non-polluting, and providing a coating film with excellent gloss. Discovered a resin composition for cationic water-based paints,
This has led to the present invention.

Means for Solving the Problems> That is, the present invention provides: (i) a fluorine-containing copolymer (a) having a reactive carbon-carbon double bond in the molecule; and an ethylenically unsaturated monomer containing an amino group. Ethylenically unsaturated monomer (b) containing monomer (b')
an aqueous resin in which at least a portion of the amino groups of the fluorine-containing graft copolymer (A) having an amine value of 5 to 150 and a hydroxyl value of 10 to 300 is neutralized with an acidic compound; and (ii) The present invention relates to a resin composition for water-based paints containing a curing agent as a main component.

The present invention will be explained in detail in 1 below.

The fluorine-containing copolymer (a) having a reactive carbon-carbon double bond in the molecule used in the present invention has a hydroxyl group,
A known fluorine-containing copolymer (a') having a functional group such as a carboxyl group, a glycidyl group, or an ami-7 group has reactivity with the functional group and has α,β-ethylenic unsaturation in the molecule. It is obtained by reacting a compound (a') having a bond.

As the fluorine-containing copolymer (a'), the fluorine-containing copolymer (a') is disclosed in JP-A-57-
Publication No. 34107, Japanese Patent Application Publication No. 136605/1983,
JP-A-59-102961, JP-A-59-102
Copolymers described in JP-A No. 962, JP-A-59-189108, JP-A-60-67518, JP-A-61-57609, JP-A-62-7767, etc. Can be mentioned. For example, as the fluorine-containing copolymer (a'), fluoroolefin; vinyl ether having a functional group, or acrylic acid or methacrylic acid monomer having a functional group; vinyl ether without a functional group (a fluorine-containing vinyl ether); or carboxylic acid vinyl ester as an essential component in proportions of 40 to 60 mol%, 0.5 to 25 mol%, and 5 to 50 mol%, respectively.

As the raw material fluoroolefin for the above-mentioned copolymer a'), it is preferable to use barhaloolefins, particularly chlorotrifluoroethylene or tetrafluoroethylene. In addition, as vinyl ethers that do not contain functional groups, cyclohexyl vinyl ether and carbon atoms of 2 to 8
Vinyl ethers having a straight or branched alkyl group are preferred, and the carboxylic acid vinyl esters include cyclohexane carboxylic acid vinyl ester, benzoic acid vinyl ester, p-tert-butylbenzoic acid vinyl ester, or vinyl ethers having 1 to 18 carbon atoms. Esters of aliphatic carboxylic acids are preferred.

The copolymer (a') as described above is prepared by adding a polymerization initiator such as a water-soluble initiator or an oil-soluble initiator or an ionizing radioactive substance to a monomer mixture in a predetermined proportion in the presence or absence of a polymerization medium. It is produced by causing a copolymerization reaction by applying a polymerization initiator.

Examples of the copolymer (a') include Lumiflon LF100, Lumiflon LF200, Lumiflon LF manufactured by Asahi Glass Co., Ltd.
210, Lumiflon LF300, Lumiflon LF400
Representative examples include Fluororesin Fluonate Ni-700 and Fluonet K-701 manufactured by Dainippon Ink and Chemicals.

As the compound (a') having an α,β-ethylenically unsaturated bond in its molecule, any compound having reactivity with the functional group of the copolymer (a’) can be selected.

For example, if the functional group of copolymer a') is a hydroxyl group,
α,β-unsaturated carboxylic acids such as maleic anhydride, acrylic acid, methacrylic acid, acrylic anhydride, methacrylic anhydride or their acid chlorides; trimethylamine-
Methacrylimide, N-methylolacrylamide, N
- Amine-methacrylimides or acrylamides such as n-butoxymethylacrylamide; Unsaturated compounds with incyanate groups such as isocyanate ethyl methacrylate and incyanato ethyl acrylate; Unsaturated compounds with glycidyl groups such as glycidyl methacrylate and glycidyl acrylate Representative examples include unsaturated compounds having an alkoxysilyl group such as vinyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane.

In addition, when the functional group of the copolymer (a') is a carboxyl group, the unsaturated compound having the glycidyl group: the amine-methacrylimide or acrylamide;
Representative examples include unsaturated compounds having an amino group such as tert-butylaminoethyl methacrylate.

In addition, when the functional group of the copolymer (a') is a glycidyl group, the α,β-unsaturated carboxylic acid; acrylic acid-2
Typical examples include unsaturated compounds having a hydroxyl group such as -hydroxyethyl and 2-hydroxyethyl methacrylate; unsaturated compounds having an amino group; and the amine-methacrylimides or acrylamides.

In addition, when the functional group having copolymer a') is an amino group, the unsaturated compound having the incyanate group;
Representative examples include β-unsaturated carboxylic acids; unsaturated compounds having the aforementioned glycidyl group, and the like.

The copolymer (a) used in the present invention is prepared by combining the fluorine-containing copolymer (a') in an organic solvent (but not having a functional group) with α,β-ethylenically unsaturated molecules in the molecule. and the compound (a') having a bond at about 20 to 140t:
This is a reaction product obtained by reacting for about 1 to 10 hours. During this reaction, a polymerization inhibitor may be added to the reaction product 100 as necessary to prevent the reaction of the double bond of compound (a').
It is added in an amount of 0.001 to 0.5 parts by weight. As polymerization inhibitors, hydroquinones such as hydroquinone,
Quinones such as benzoquinone, phenols such as alpha-naphthol, organic or inorganic copper salts such as copper naphthenate,
Examples include amidines such as acetamidine acetate, and quaternary ammonium salts such as trimethylbenzylammonium chloride.

A reaction catalyst can also be used if necessary.

In addition, copolymer (a) has reactive carbon-carbon double bonds in its molecules, and the number of reactive carbon-carbon double bonds in 100 g of copolymer (a)
0.001 to 0.2 mol, particularly preferably 0.00 mol in
4 to 0.04 mol is desirable; if it is less than the above range, it becomes difficult for the ethylenically unsaturated monomer (6) described below to graft polymerize; on the other hand, if it is too much, the system becomes unstable during graft polymerization, leading to gelation. It tends to occur more easily.

Ethylenically unsaturated monomer (b) containing amino group-containing ethylenically unsaturated monomer (b') used in the present invention
is graft-polymerized with the copolymer (a) to produce a fluorine-containing graft copolymer (A).

The amine 7 group-containing engineered tylenically unsaturated monomer (b') is
It has a primary, secondary or tertiary amino group in its molecule, specifically aminoaryl, acrylic acid te
Typical examples include rt-butylaminoethyl, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, tert-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like. The ethylenically unsaturated monomer υ may be the monomer (b') alone, but it is desirable to use other ethylenically unsaturated monomers (b') together in view of coating film performance.

As the ethylenically unsaturated monomer (b'), acrylic acid 2
- (Meth)acrylic acid esters such as hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; monoacrylate or monomethacrylate of polyhydric alcohols such as glycerin and trimethylolpropane , N-methylol acrylamide, N-methylol methacrylamide, acrylamide, ethylenically unsaturated monomers with functional groups such as methacrylamide, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylic 1in- butyl,
Isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, tridecyl acrylate, stearyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylic acid (Meth)acrylic acid esters such as isopropyl, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, and cyclohexyl methacrylate; styrene or substituted styrene such as vinyltoluene, α-methylstyrene, chlorostyrene; acrylonitrile, methacrylonitrile, vinyl chloride, vinyl formate,
Typical examples include ethylenically unsaturated monomers without functional groups such as vinyl acetate, vinyl propionate, vinyl stearate, dialkyl maleate, and divinylbenzene.

In addition, in order not to reduce weather resistance, the general formula: CH2=C
A fluorine-containing ethylenically unsaturated monomer represented by -COOX, specifically CH2=CHC00CH, CF, CH2= CHCOOCH2CF 2CF -H.

CH2=CHC00CH2(CF2CF,)2H.

CH,=CHC00CH2(CF2CF2)3H.

CH3C,H.

CH2= CCOOCHHz CH2N S O2Cs
F l7, CHri” CHCOOCH2CH2C-F
1-1CH2= CHCOOCH2CH2RF (R
F; a mixture of CsF+s to C,, F21), and silicon-containing ethylenic inorganics such as vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, T-methacryloxypropyltriethoxysilane, etc. Saturated monomers may also be used.

Fluorine-containing graft copolymer used in the present invention (
In A), the copolymer (a) and the ethylenically unsaturated monomer (b) are combined with a peroxide-based radical initiator such as benzoyl peroxide or ditertiary-butyl peroxide, or azobisisobutyronitrile. , in the presence of a radical initiator such as an azo radical initiator such as azobisvaleronitrile,
Radical polymerization was carried out at about 80 to 140°C for 3 to 10 hours.

The amount of the ethylenically unsaturated monomer (b) used is 15 to 70% by weight, preferably 2% by weight in the graft copolymer (A).
A range of 5 to 60% by weight is desirable. If the amount of the ethylenically unsaturated monomer (b) is less than the above range, the gloss of the resulting coating film will decrease and the adhesion to the object to be coated will decrease, while if it is too large, the weather resistance will tend to decrease. It is in.

The amino group derived from the amino group-containing ethylenically unsaturated monomer (b') in the fluorine-containing graft copolymer (A) is indispensable during the aqueousization described below, and therefore the amine value is It is preferably 5 to 150, particularly 30 to 150. If the amine value is less than the above range, it will be difficult to make it water-soluble and the storage stability will be poor, while if it is too large, the water resistance of the coating film will be poor, which is not preferable.

In addition, the hydroxyl groups derived from the fluorine-containing copolymer (a) and/or the ethylenically unsaturated monomer (b) in the fluorine-containing graft copolymer (A) undergo a crosslinking reaction with the curing agent described below. Therefore, the hydroxyl value is 10 to 3.
00, particularly preferably 30 to 150. If the hydroxyl value is less than the above range, the curability of the coating film will be poor, whereas if it is too large, the water resistance etc. of the coating film will be poor, which is not preferable.

The aqueous resin (i) used in the present invention has a weight average molecular weight of 2.000 to 150, which is made by at least partially neutralizing the fluorine-containing graft copolymer <A) with an acidic compound and making it soluble or dispersible in water. .000 resin. In addition, neutralization with an acidic compound is 0.5 to 0.5 to the amino group equivalent.
Neutralize with 1.5 equivalents, preferably 0.8 to 1.1 equivalents.

Such acidic compounds include formic acid, acetic acid, propionic acid,
Representative examples include organic acids such as oxalic acid and lactic acid; and inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid.

The thus neutralized aqueous resin (i) is dissolved or dispersed in water to form an aqueous liquid.

The curing agent (ii) used in the present invention is preferably a blocked isocyanate compound, aminoplus 11, but is not limited to these, and is stably dissolved or dispersed in water and reacts with the hydroxyl group of the aqueous resin. Conventionally known curing agents can be used as long as they can be used.

The blocked isocyanate compound is an aliphatic or alicyclic diisocyanate such as hexamethylene diisocyanate, tetramethylene diisocyanate, inphorone diisocyanate, hydrogenated diphenylene diisocyanate, hydrogenated xylylene diisocyanate, or a knee left form or dimer thereof, Polyisocyanate compounds, which are reaction products of trimers or excess of these incyanate compounds and low-molecular-weight polyols such as ethylene glycol, glycerin, trimethylolpropane, and pentaerythritol, can be used as phenols, alcohols, oximes, and lactams. It is a compound masked with a masking agent such as amines, amines, or amides.

The aminoplast resin is a condensation product of an amino compound such as melamine, urea, benzoguanamine, or acetoguanamine and an aldehyde compound, or a resin obtained by further etherifying the condensation product with an alcohol such as methanol or butanol.

In addition, the mixing ratio of the aqueous resin (i) and the curing agent (ii) is such that when a blocked isocyanate compound is used, the equivalent ratio of the isocyanate group of the compound to the hydroxyl group of the aqueous resin (NGOloH) is 0.2/1 to 1. 2,5/1
, especially in a range of 0.5/1 to 1.5/l, and the original resin properties are exhibited within this range.

On the other hand, when using aminoplast resin, the mixing ratio (weight basis) of water-based resin and aminoplast resin is 95:5.
~50:401, especially 90:10~70:30 is suitable.

The resin composition for coatings of the present invention has the water-based resin (i) and curing agent (ii) as main components, and has a solid content of about 10%.
It is made into a paint by dissolving or dispersing it in water to a concentration of ~50% by weight.

In addition, the resin composition for waste materials of the present invention may also contain organic solvents, coloring pigments, rust preventive pigments, extender pigments, modified resins,
plasticizer, desiccant or ultraviolet absorber, leveling agent,
It is possible to incorporate various additives such as anti-cissing agents and anti-crisp agents.

The paint obtained in this way can be used not only on various metal materials such as steel plates, stainless steel plates, and aluminum plates, but also on mortar,
It can be applied to coating inorganic materials such as concrete and glass, and plastic materials.

Further, various coating methods such as spray coating, electrodeposition coating, dipping coating, roller coating, and flow coating can be used.

The coating film is usually cured at a temperature of 100 to 240°C for several seconds to 20
It can be cured in about minutes.

<Effects of the Invention> The resin composition for water-based paints of the present invention takes advantage of the long-term weather resistance, durability, and corrosion resistance of the fluorine-containing copolymer, and is also water-based, making it non-polluting and resource-saving. Furthermore, since the ethylenically unsaturated monomer is graft-polymerized to the fluorine-containing copolymer, it is possible to improve the appearance of the coating film, such as gloss and sharpness.

Hereinafter, the present invention will be explained in detail with reference to Examples.

In the examples, "parts" and "%" are based on weight unless otherwise specified.

(a) to (a) of the functional group-containing fluorine-containing copolymer (a')
(2) Preparation> Polymerize the monomer composition listed in Table 1 according to a known method,
(a) to (t) of functional group-containing fluorine-containing copolymer a')
was prepared. Note that the numerical values in the table indicate mol%.

11 ml of the solution of the carbon-carbon double bonded gold-containing fluorine copolymer (a) (1) to (force)
') Solution (solid content concentration 50%) [However, the numbers in the table are amounts (parts) in terms of solid content. ) and an unsaturated compound in a xylene solution in the presence of a reaction catalyst to prepare a carbon-carbon double bond gold-containing fluorine copolymer solution (technique) to (force) with a solid content concentration of 50%. did.

Preparation of (g) to (c) of fluorine-containing graft copolymer (A) solution> Unsaturated group-containing fluorine-containing copolymer (a) in the proportions shown in Table 3
) Solution (solid content concentration 50%) [However, the numbers in the table are amounts (parts) in terms of solid content. ] and α, β-ethylenically unsaturated monomer (b), acetic acid ethylene glycol monoethyl ether was added so that the solid content after polymerization was 60%, and azobisisobutyronitrile In the presence of 8
The mixture was reacted at 0° C. for 4 hours, and azobisisobutyronitrile was added thereto, and the mixture was reacted at 90° C. for 4 hours to prepare fluorine-containing graft copolymer (A) solutions (k) to (c).

<Preparation of acrylic copolymer solutions (S) to (C)> Acetic acid ethylene glycol monoethyl ether was added to the mixture of α,β-ethylenically unsaturated monomers in the proportions shown in Table 3, and the solid after polymerization 60%, reacted in the presence of azobisisobutyronitrile at 80°C for 4 hours, further added azobisisobutyronitrile, and 90°C
The mixture was reacted for 4 hours to prepare acrylic copolymer solutions (S) to (C).

Examples 1 to 2 and Comparative Examples 1 to 2 Based on the formulations shown in Table 4, fluorine-containing graft copolymer solutions (Q) and (RI) and acrylic copolymer solution (
Using (S) and (C), 11 cationic electrodeposition paints with a solid content concentration of 10% were prepared. These were electrodeposited on an iron plate treated with zinc phosphate so that the dry film thickness was approximately 15 μm! ! ! equipped. The lower part of Table 4 shows the results of the coating film performance.

As is clear from the table, Examples 1 and 2 were superior to Comparative Examples 1 and 2 not only in coating film appearance and adhesion but also in weather resistance.

Examples 3 to 4 and Comparative Examples 3 to 4 Based on the formulations shown in Table 5, fluorine-containing graft copolymer solutions (k) and (k) and acrylic copolymer solution (
A water-based paint was prepared using (S) and (C).

These were mixed with water to a viscosity of 22 seconds (Ford Cup Nα4.2
After adjusting the temperature to 0° C.), spray coating was applied to an iron plate treated with zinc phosphate so that the dry film thickness was approximately 35 μm.

The lower part of Table 5 shows the results of the performance of the coating film.

As is clear from the table, Examples 3 and 4 have almost the same level of gloss as acrylic paints, which are known as paints that can provide high-gloss coatings, and also have accelerated weather resistance, acid resistance, alkali resistance, etc. It was excellent. On the other hand, Comparative Examples 3 and 4 had good initial gloss but were poor in accelerated weather resistance, acid resistance, and alkali resistance.

Claims (2)

[Claims] (1) (i) Ethylenically unsaturated containing a fluorine-containing copolymer (a) having a reactive carbon-carbon double bond in the molecule and an ethylenically unsaturated monomer (b') containing an amino group amine value 5 to 150, obtained by reacting with monomer (b),
Fluorine-containing graft copolymer (A
1. A resin composition for an aqueous paint, which contains as main components an aqueous resin in which at least a portion of the amino groups of (a) are neutralized with an acidic compound, and (ii) a curing agent. (2) The resin composition for an aqueous paint according to claim 1, wherein at least one of the fluorine-containing copolymer (a) and the ethylenically unsaturated monomer (b) has a hydroxyl group.