JPH05202260A - Aqueous curable resin composition - Google Patents

Abstract

(57) [Summary] [Structure] A fluoroolefin represented by chlorotrifluoroethylene or hexafluoropropylene, an epoxy group, a (substituted) amino group, a carboxyl group,
Aqueous dispersion of fluororesin obtained by copolymerization of monomers mainly composed of various functional group-containing monomers represented by sulfonic acid group, hydroxyl group or blocked isocyanate group, and such functional group An aqueous curable resin composition, which comprises, as an essential component, an aqueous resin dispersion having another functional group that reacts with each other. [Effect] It has excellent curability at a relatively low temperature, and has excellent durability such as weather resistance, chemical resistance, water resistance, boiling water resistance, and alkali resistance, as well as excellent stain resistance. , Very practical and expensive.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel and useful aqueous curable resin composition. More specifically, each has at least two types of aqueous dispersions as main components, each having a curing site, one being an aqueous dispersion of a fluororesin and the other being an aqueous dispersion of another resin, The present invention relates to a highly practical aqueous curable resin composition that can be cured at a relatively low temperature.

[0002]

2. Description of the Related Art In recent years, paints that are exposed to the outdoors such as building exterior materials and industrial materials are required to have long-term maintenance-free properties that are excellent in durability.

Fluoroolefin copolymers are well known as binders having high weather resistance and high chemical resistance, and those in the form of an organic solvent solution are
It is already on the market.

However, since it contains a large amount of organic solvent, there are problems such as fire hazard, harmfulness and air pollution, and an aqueous fluoroolefin binder is required.

So far, tetrafluoroethylene,
Aqueous dispersions of various fluoroolefin polymers have been proposed, such as vinylidene fluoride or hexafluoropropylene.

However, all of these fluoroolefin polymer aqueous dispersions require baking at a high temperature during the film formation process. That is, for example, in the invention described in JP-A-57-38845, in the case of vinylidene fluoride and hexafluoropropylene copolymer, baking at a temperature in the range of 180 to 230 ° C. is required. .

[0007] Such high temperature baking is almost impossible in the field of the normally dry paint to be applied on site, and
It can be said that it is economically disadvantageous even in factory line painting, which mainly uses heat drying.

On the other hand, JP-A-61-261367 discloses an emulsion polymer-based coating composition comprising a fluoroolefin, an alkyl vinyl ether and a carboxylic acid vinyl ester as a solution to such a problem. And the film forming property is significantly improved.

[0009] However, it is important that the coating material for the article to be exposed to the outdoors not only has durability but also does not deteriorate in appearance due to contamination of the coating film by smoke or the like. Generally, in order to obtain film-forming properties at low temperatures, it is necessary to lower the glass transition point of the resin, the minimum film-forming temperature, etc., and as a result, the resulting coating film becomes soft and, by extension, stain resistance. Results in the lack of.

Therefore, it is possible to form a film at a low temperature, and moreover, both so-called coating film durability such as weather resistance, chemical resistance, water resistance, boiling water resistance and alkali resistance, and stain resistance are obtained. The advent of a water-based coating agent that sufficiently satisfies the performance has been eagerly demanded.

[0011]

The object of the present invention is to enable film formation at a low temperature such as room temperature.
An extremely practical water-based fluoroolefin-based coating agent that has excellent durability such as weather resistance, chemical resistance, water resistance, boiling water resistance, and alkali resistance, and also has excellent stain resistance. To provide.

[0012]

Therefore, the present inventors have
As a result of direct investigation of the advantages and disadvantages of the above-described conventional technology and repeated intensive studies, a fluororesin aqueous dispersion was used as the main component, and further, another type of resin capable of curing the fluororesin was used. It has been found that a composition containing an aqueous resin dispersion as an essential component solves and overcomes the above problems brilliantly, and has completed the present invention.

That is, each of the present invention has an aqueous dispersion (A) of a fluororesin having a curable site and a functional group capable of reacting with the curable site of the fluororesin.
Aqueous resin dispersion (B) different from the above aqueous dispersion (A)
The present invention is intended to provide an aqueous curable resin composition containing as an essential component.

Needless to say, it may be the case where the two or more aqueous dispersions having functional groups capable of reacting with each other are both fluororesins, and such a special combination is used. There is not much accumulation to eliminate.

[0015]

Here, the above-mentioned fluororesin aqueous dispersion (A) having a curable site means a functional group capable of reacting with a functional group contained in various aqueous resin dispersions (B) as described later. This refers to a fluororesin aqueous dispersion having a group.

The combinations of functional groups capable of reacting with each other include (1) epoxy group and (substitution), respectively.
A combination with an amino group, (2) a combination with an epoxy group and a carboxyl group and / or a sulfonic acid group, (3) a combination with an epoxy group and a hydroxyl group, (4) a hydroxyl group and a (substituted) amino group A combination of (5) a hydroxyl group and a blocked isocyanate group, or (6) a combination of a carboxyl group and / or a sulfonic acid group and a blocked isocyanate group are particularly representative. It should be understood that any combination of functional groups capable of reacting with each other is included in the present invention.

Of these combinations, one is allowed to exist in the fluororesin aqueous dispersion (A), and the other is used, or as an aqueous dispersion (B) other than the fluororesin aqueous dispersion (A). When there are a plurality of materials, all the rest may be contained in the aqueous resin dispersion (B).

In order to introduce these functional groups into (A) or (B), the following method can be used. First
The method of (1) is a method of introducing such monomers having various functional groups by copolymerizing them with the monomers constituting (A) or (B).

The second method is (A) or (B)
After the resin dispersion is obtained, it is introduced by a method such as chemical modification (denaturation). Of these, the former method is simple and preferable.

In these methods, a combination of functional groups which easily react with water from the place where the medium is water is not suitable. Of the monomers having these functional groups, only typical ones will be exemplified. (1) Examples of the epoxy group-containing monomer include allyl glycidyl ether and glycidyl (meth) acrylate. it can. (2) As the (substituted) amino group-containing monomer, allylamine, (meth) acrylamide, N-methylol (meth) acrylamide, N-alkoxymethylated (meth)
Various polyvalent carboxylic acid anhydride group-containing monomers such as acrylamide, N, N-dialkyl (meth) acrylamide, diacetone acrylamide, N, N-dialkylaminoalkyl (meth) acrylate or maleic anhydride, and these Examples thereof include various tertiary amino group-containing monomers typified by adducts with a compound having an active hydrogen group capable of reacting with and a tertiary amino group.

(3) As the carboxyl group-containing monomer, various acid anhydrides such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride or itaconic anhydride are used. Unsaturated group-containing hydroxyalkyl ester monocarboxylic acids such as adducts of group-containing monomers and glycols; or various dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid or citraconic acid listed above Can be illustrated. Examples of (4) sulfonic acid group-containing monomers include 2-acrylamido-2-methylpropanesulfonic acid.

(5) As the hydroxyl group-containing monomer, hydroxyl group-containing vinyl ethers such as various hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether; or 2-hydroxyethyl. (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth)
Examples thereof include acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate and the like. (6) Examples of the blocked isocyanate group-containing monomer include blocked products of isocyanate alkyl (meth) acrylate.

To obtain the component (A) constituting the present invention,
Monomers having various curable sites as described above are used in an amount of 1 to 35% by weight in all monomer raw materials (the same applies hereinafter), and a fluoroolefin-based monomer as described below is used. The amount of the monomer may be 30 to 70% by weight, and other monomers may be used in a range not exceeding 50% by weight for polymerization.

Other monomers are preferably various olefins such as ethylene and propylene; or vinyl esters of various carboxylic acids such as vinyl acetate and vinyl versatate, and more preferably, In addition to these, combined use with acidic group-containing monomer,
Furthermore, the combined use with a crosslinkable monomer for performing crosslinking in the particles in advance gives good results.

As only specific examples of the fluoroolefin constituting the component (A), vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, 1,1,3
3,3-pentafluoropropylene, 2,2,3,3-
Tetrafluoropropylene, 1,1,2-trifluoropropylene, 3,3,3-trifluoropropylene, chlorotrifluoroethylene, bromotrifluoroethylene, 1-chloro-1,2-difluoroethylene, 1,1
-Dichloro-2,2-difluoroethylene and the like.

Of these, fluoroolefins such as hexafluoropropylene, chlorotrifluoroethylene and vinylidene fluoride are preferred. More preferably, chlorotrifluoroethylene is used from the viewpoint of reaction control during polymerization.

As other monomers, various (halogenated) olefins such as ethylene, vinyl chloride, vinylidene chloride, propylene and butene-1; or vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate. , Vinyl pivalate, vinyl caproate, vinyl versatate (vinyl neononanoate, vinyl neodecanoate), vinyl laurate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl p-t-butylbenzoate, and others. Examples thereof include vinyl esters of various carboxylic acids such as "Veoba" (vinyl ester manufactured by Shell Co.).

Among these, the carboxylic acid of the vinyl ester monomer of carboxylic acid is a linear, branched or cyclic carboxylic acid having 5 or more carbon atoms, the weather resistance of the film, etc. Is preferable, and more preferably, one having 6 or more carbon atoms.

That is, a linear chain having 5 or more carbon atoms,
The branched or cyclic carboxylic acid vinyl ester monomer improves the water repellency of the coating film finally obtained from the fact that it has a bulky alkyl group in the molecular structure. It has the effect of suppressing the hydrolysis of the ester bond due to the water and basic substances.

Therefore, by using these monomers, the long-term boiling water resistance after film formation,
It is a place to further satisfy various performances such as high temperature alkali resistance.

Examples of the acid group-containing monomer include acid anhydride group-containing monomers such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride or itaconic anhydride. Unsaturated group-containing hydroxyalkyl ester monocarboxylic acids such as adducts with glycol; or various dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid or citraconic acid described above; or 2-acrylamido-2 Examples thereof include monomers having a sulfonic acid group such as methylpropanesulfonic acid.

Of these, use of crotonic acid or itaconic acid is preferable from the viewpoint of copolymerizability. The purpose of introducing the acid group-containing monomer is not only to use it as a curable site, but also to improve the stability of the aqueous dispersion, and to adhere it to the substrate when it is finally used. This is to improve the sex.

The amount of the acid group-containing monomer to be used is generally less than 5% of all monomers, preferably 3%, excluding the amount used as a crosslinking point used in the curable site described above. Less than% is appropriate.

In addition to the above, in order to further improve the final coating performance, a crosslinking monomer as shown below can be used in advance for the purpose of crosslinking within the particles of the resin dispersion. Examples of such monomers include hexadiene, octadiene, decadiene, tetradecadiene, 2
-Methyl-octadiene, decatriene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, trivinylbenzene, diallyl phthalate, no difference in radical reactivity Monomers having two or more polymerizable unsaturated groups in one molecule;

Alternatively, vinyltriethoxysilane, trimethoxysilylvinylether, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ
Examples thereof include hydrolyzable silyl group-containing monomers such as-(meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, and tris (2-methoxyethoxy) vinylsilane.

Of these, one or a mixture of two or more selected from hexadiene, octadiene, decadiene, tetradecadiene, 2-methyl-octadiene and decatriene and / or vinyltriethoxysilane, trimethoxysilylvinylether, γ -(Meth) acryloyloxypropyltrimethoxysilane,
Hydrolysis such as γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, tris (2-methoxyethoxy) vinylsilane The silyl group-containing monomers are preferable also from the viewpoint of providing a stable aqueous dispersion.

The purpose of intra-particle crosslinking is to improve durability such as water resistance, alkali resistance and solvent resistance, or a polymer having a low glass transition point,
Moreover, this is because the film obtained from the polymer has toughness.

Of course, when these durability is unnecessary,
No need to use. As the amount of the crosslinkable monomer used,
Generally, less than 3%, preferably less than 2% is suitable.

Other examples of usable monomers include trifluoromethyl vinyl ether, 1,1,1-
Trifluoroethyl vinyl ether, 2,2-difluoroethyl vinyl ether, tetrafluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, perfluorohexyl vinyl ether, perfluorooctyl vinyl ether, perfluorododecyl vinyl ether, 2,2,2.
3,3-tetrafluoropropyl vinyl ether, 2,
2,3,3,4,4,5,5-octafluoropentyl vinyl ether, 2,2,3,3,4,4,5,5
6,6,7,7,8,8,9,9-hexadecafluorononyl vinyl ether, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether, or perfluorocyclohexyl vinyl ether, Various (per) fluoroalkyl vinyl ethers;

Vinyl ethers having a fluoroalkyl group having a carbon number of 3 to 12 in which a part of hydrogen atoms are substituted with fluorine atoms; "Biscoat 8F, 8FM, 3F or 3FM" [Osaka Organic Chemical Co., Ltd.] Fluorine-containing (meth) acrylic monomer], perfluorocyclohexyl (meth) acrylate, and N-i-propylperfluorooctanesulfonamidoethyl (meth) acrylate having a (per) fluoroalkyl group. Various (meth) acrylic acid esters obtained by the esterification reaction of alcohol and (meth) acrylic acid;

(Per), such as trifluoroacetic acid vinyl ester, jieperfluorocyclohexyl fumarate,
Vinyl esters having a fluoroalkyl group; methyl-, ethyl-, n-propyl-, isopropyl-, n-
Alkyl vinyl ethers having various linear or branched alkyl groups such as butyl-, isoamyl-, n-hexyl-, n-octyl-, or 2-ethylhexyl vinyl ether; cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl Cycloalkyl vinyl ethers having various (alkyl-substituted) cyclic alkyl groups such as vinyl ethers; aralkyl vinyl ethers such as benzyl vinyl ether or phenethyl vinyl ether;

P-styrenesulfonamide, N-methyl-p-styrenesulfonamide, N, N-dimethyl-p
-Sulfonamide group-containing monomers typified by styrene sulfonamide; cyano group-containing monomers typified by (meth) acrylonitrile; α, β-, such as (meth) acrylic acid hydroxyalkyl ester Monomers having a phosphoric acid ester group, obtained by condensation reaction of hydroxyalkyl esters of ethylenically unsaturated carboxylic acid and phosphoric acid esters;

Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-
(Meth) acrylic acid alkyl esters having a linear or branched alkyl group of C _{1 to} C _{8 such as} ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate, or a cyclic alkyl group; Aromatic vinyl compounds such as styrene, α-methylstyrene, p-tert-butyl-styrene, p-methylstyrene; (substituted) aromatic nucleus-containing (meth) acrylic acid esters such as benzyl (meth) acrylate Or a diester of an unsaturated dicarboxylic acid with a monovalent alcohol, such as maleic acid, fumaric acid or itaconic acid.

These monomers are appropriately selected in order to control the glass transition point of the copolymer finally obtained and the throat of the minimum film forming temperature, and are selected as one kind or a mixture of two or more kinds. Used.

The fluororesin aqueous dispersion (A) having a curable site used in the present invention is obtained by polymerizing the various monomers described above in the presence of an emulsifier in an aqueous medium. It is obtained by merging.

The emulsifier referred to herein is used in order to stably disperse the above-mentioned various monomers in an aqueous medium and to sufficiently exert various properties of the coating film in the final use mode. The anionic emulsifier and / or the nonionic emulsifier can be used. Of these, only typical ones will be exemplified as follows.

That is, first, as the anionic emulsifier (including the reactive emulsifier), alkyl (benzene) is used.
Examples thereof include a sulfonate, an alkyl sulfate salt, a polyoxyethylene alkylphenol sulfate salt, a styrene sulfonate, a vinyl sulfate salt, or a derivative thereof.

The salt as used herein refers to a salt of an alkali metal hydroxide or a salt of a volatile base such as ammonia or triethylamine.

Of these, it is desirable to use one or a mixture of two or more selected from (substituted) alkyl (benzene) sulfonates and vinyl sulfonates.
Examples of nonionic emulsifiers (including reactive emulsifiers) include polyoxyethylene alkylphenol ethers,
Examples thereof include polyoxyethylene alkyl ethers, polyoxyethylene higher fatty acid esters, ethylene oxide-propylene oxide block copolymers, various derivatives thereof, and the like, and one kind or a mixture of two or more kinds is used.

Of these, the use of polyoxyethylene (substituted) alkyl (phenyl) ether is preferable from the viewpoint of the physical properties of the film finally obtained. In addition, it is also possible to use in combination with various fluorine atom-containing emulsifiers such as fluoroalkylcarboxylic acid salts represented by perfluorooctanoic acid salts and fluoroalkyl sulfates.

The amount of these emulsifiers to be used is appropriately in the range of 0.5 to 10% by weight based on the total amount of the monomers, including the anionic emulsifier and the nonionic emulsifier. Further, in combination with these, various water-soluble polymer substances such as water-soluble oligomers composed of polycarboxylic acid and sulfonate, polyvinyl alcohol or hydroxyethyl cellulose can be used as protective colloid.

The polymerization initiator is not particularly limited as long as it is one generally used in emulsion polymerization. Among them, only typical ones are exemplified by various water-soluble inorganic peroxides such as hydrogen peroxide; various peroxides such as ammonium persulfate, potassium persulfate and sodium persulfate. Sulfates; various organic peroxides such as cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide;
Various azo initiators, such as azobisisobutyronitrile and azobiscyanovaleric acid, may be used alone or in combination of two or more.

The amount used is based on the total amount of monomers.
0.1 to 2% by weight is preferable. Needless to say, a so-called redox polymerization method in which these polymerization initiators are used in combination with a metal ion and a reducing agent may be used.

Specific examples of the reducing agent include sodium bisulfite, sodium metabisulfite, sodium bithiosulfate, sodium hydrosulfate, sodium formaldehyde sulfoxylate, and reducing sugars.

As an example of the metal ion,
Examples include copper sulfate, ferric chloride, ferric sulfate, and silver nitrate. Furthermore, it goes without saying that various chain transfer agents can also be used.

The component (A) is obtained by co-existing an aqueous medium, preferably ion-exchanged water, and an emulsifier, with the monomers individually or in an emulsified state, either collectively or in a divided form. Or continuously, in a reaction vessel, in the presence of a polymerization initiator as described above, about 1 k
With a gauge pressure of g / cm ^{2 to} 100 kg / cm ² , and
Polymerization may be carried out at a reaction temperature of about 50 ° C to 150 ° C.

In some cases, there is no problem even if the polymerization is carried out under a pressure higher than this or a temperature lower than this. The ratio of the total monomer amount to water is such that the final solid content is 1 to 60% by weight, preferably 15
It should be set to be in the range of 55 wt%.

Further, in carrying out emulsion polymerization, in order to grow or control the particle size, a seed polymerization method may be used in which emulsion particles are present in the aqueous phase in advance and polymerization is carried out.

As the water in the aqueous medium used here, ion-exchanged water is basically used, and the amount used is preferably 70% by weight or more in the aqueous medium. The remaining less than 30% by weight may be used in combination with an organic solvent.

The organic solvent mentioned here is not particularly limited, and any general-purpose organic solvent can be used. Of these, only typical ones are exemplified: ketone-based compounds such as acetone, methyl ethyl ketone and methyl amyl ketone; ester-based compounds such as ethyl acetate and butyl acetate; or benzene,
Aromatic hydrocarbons such as toluene and xylene;

Aliphatic hydrocarbons such as hexane and heptane; alcohols such as methanol, ethanol, isopropanol and butanol; or halogen-containing organic compounds including freon solvents such as carbon tetrachloride, methylene dichloride and hexafluoroisopropanol. Such as a solvent.

Of these, it is desirable to use an organic solvent having a high affinity for water or a high ability to dissolve olefins and fluoroolefins in an aqueous medium.

That is, particularly recommended organic solvents are various hydrophilic solvents such as acetone, methyl ethyl ketone, methanol, ethanol and isopropanol, and various freon solvents such as hexafluoroisopropanol.

Here, carbon tetrachloride, heptane, and the like may act as telogen, so that the amount used should be particularly careful when adjusting the molecular weight. The polymerization reaction must be carried out under the condition that side reactions due to functional groups do not proceed.

For example, in terms of pH, adjustment may be carried out using various sodium phosphate buffers or borax, or various pH buffering agents such as sodium hydrogen carbonate or ammonia.

In particular, when a vinyl ether-based monomer is used for copolymerization, a side reaction may occur in both the low pH range and the high pH range. , PH should be 4-10.

In this way, the fluororesin aqueous dispersion which is the component (A) of the composition of the present invention is obtained. The state of the system after the reaction is the same as that of the unreacted gaseous monomer in the emulsion particles. The body remains, albeit a very small part.

Although most of the remaining monomer is unreacted fluoroolefin, the following procedure was carried out in order to safely remove such gaseous monomer so as not to destroy the emulsion. Should be done.

That is, when the obtained resin dispersion is based on a resin having an acidic group, it is a basic substance,
After neutralizing all or part of the acidic groups of the acid group-containing monomer converted into a polymer, unreacted monomers are removed, or a silicon-based and / or mineral oil-based compound is added. After that, it is recommended to take an operation of removing unreacted monomers.

Examples of the basic substance include inorganic hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal hydroxides, organic amines such as triethylamine, and ammonia.

Among these, it is desirable to use organic amines such as triethylamine and volatile basic substances such as ammonia. On the other hand, as the silicon-based compound and / or the mineral oil-based compound, a known and commonly used aqueous defoaming agent may be used.

As a method for removing unreacted monomers,
At room temperature or under heating at 100 ° C. or lower, unreacted gaseous monomer can be removed under normal pressure or reduced pressure, or a steam distillation method or the like can be used.

At this time, by bubbling an inert gas such as nitrogen gas into the system, removal of unreacted gaseous monomer can be promoted. The fluororesin aqueous dispersion (A) of the present invention thus obtained generally has a number average molecular weight in terms of a state in which the crosslinkable monomer in the particles is not contained (that is, when viewed as an uncrosslinked state). Is 5,000 to 1,000,000, the weight average molecular weight is 10,000 to 3,000,000, and the minimum film forming temperature is about -10 ° C to 60 ° C.

The particle size is about 0.0
A range of 2 to 0.5 microns is suitable. Next, the aqueous resin dispersion (B) having a functional group capable of mutually reacting with the curable site in the component (A) has a functional group as determined in the above-mentioned combination system of functional groups. A water-based resin dispersion is referred to as (A)
Similar to the component, it may or may not contain a fluoroolefin monomer.

When it is contained, it can be obtained in the same manner as the preparation of the component (A) described above. When it is not contained, it may be prepared according to a usual emulsion production method, or a polymer obtained by a solution polymerization method and then converted into an aqueous dispersion by a transfer emulsification method.

The monomer that can be used at that time must be appropriately selected from the above-mentioned monomers according to the physical properties required for the final coating film. The mixing ratio of the component (A) and the component (B) is determined by the molar ratio of the functional groups contained in each aqueous dispersion and capable of reacting with each other.

The ratio of the functional groups in the component (B) to the functional groups in the component (A) is generally 0.1 to 10.
A ratio that is within the range is appropriate. Of course, when strict performances are not required, the range may be less than or more than this range.

In order to accelerate the crosslinking reaction, a known and commonly used curing catalyst which catalyzes the elementary reaction between the functional groups described above may be added. The aqueous curable resin composition of the present invention includes various inorganic pigments such as titanium oxide, mica, talc, clay, precipitated barium sulfate, silica powder, calcium carbonate, iron oxide, zinc oxide, aluminum powder and carbon;
Various organic pigments such as azo-based, phthalocyanine-based, and quinacridone-based; or plastic pigments, dispersed pigments in which these pigments are dispersed in water with an emulsifier or dispersant, and the like. It is appropriately selected and used according to the purpose.

Further, various additives necessary for forming a coating, for example, a dispersant, a wetting agent, a film-forming aid, a thickener, a thixotropic agent, an ultraviolet absorber, an antioxidant, a water repellent, and a freezing agent. Inhibitor,
The use of an antiseptic / antifungal agent or an antifoaming agent is appropriately selected and used in consideration of the performance of the resulting coating film.

As the base material coated with the aqueous curable resin composition of the present invention, metal, plastic, wood, glass, cement base material, paper or fiber is particularly representative.

As a coating method, brush coating, spray coating, coating with a roll or a flow coater, and further dipping coating such as depping are particularly representative. Accordingly, the cured film can be obtained by a method of heating and drying at a low temperature after the setting time, or drying at a room temperature.

When heating and drying, the temperature is generally 120 ° C.
It may be dried at any of the following temperatures for any time. The composition of the present invention is characterized in that it has excellent weather resistance, chemical resistance, stain resistance, etc. of its advanced coating film, as well as excellent boiling water resistance for a long period of time and alkali resistance at high temperatures. It is also used as a water-based coating composition for exterior or interior, as a coating agent for metal, plastic, wood, inorganic substrate, paper or fiber, or as a treating agent. You can

[0083]

EXAMPLES Next, the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples. In the following, all parts and percentages are by weight unless otherwise specified. There is.

Reference Example 1 (Preparation Example of Fluororesin Aqueous Dispersion (A) Having Curable Site) 2 liter stainless steel pressure resistant reaction vessel (autoclave) equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a temperature controller. ) Is thoroughly replaced with nitrogen gas, and 800 g of ion-exchanged water and 20 g of sodium dodecylbenzenesulfonate are added.
g, polyoxyethylene nonyl phenyl ether 20
g and 10 g of borax as a pH buffer are added and dissolved. Next, 300 g of vinyl neodecanoate, 100 g of vinyl acetate, 30 g of crotonic acid and 500 g of liquefied and collected chlorotrifluoroethylene are charged. Then, ethylene gas is injected under pressure until the pressure reaches 15 kg / cm ² . The internal temperature of the autoclave is raised to 80 ° C.

At this time, the pressure in the system during the reaction was about 30 kg.
Adjust ethylene gas so that it becomes / cm ² . Then, at the same temperature, 5 g of potassium persulfate was added to 20 g of ion-exchanged water.
An aqueous catalyst solution dissolved in 0 g is pressed into the reaction vessel over 3 hours. After the addition of the aqueous catalyst solution, the temperature is maintained for 10 hours to allow the polymerization reaction to proceed. The pH during the reaction proceeded at 3.5. During the reaction, the pressure in the system decreases as the monomer is consumed, but the pressure of the reaction system is maintained at 30 kg / cm ² by introducing ethylene each time. After completion of the reaction, the reaction mixture was cooled to room temperature, 14% aqueous ammonia was added until the pH reached about 7.0, and 1 g of a 5% aqueous dispersion of a silicon antifoaming agent (San Nopco's Nopco 8034L) was added, Stir well. Next, the unreacted gas is gradually taken out of the system and the system pressure is returned to normal pressure. Then, the unreacted gas dissolved in the dispersion is distilled off under reduced pressure. The obtained dispersion is a white aqueous dispersion having a non-volatile content having a carboxyl group as a curable site, 48%, pH 7.0, a minimum film forming temperature of 28 ° C., and an average particle diameter of 80 nm. Hereinafter, this is referred to as (A-1).

Reference Examples 2 to 4 (Preparation Example of Fluororesin Aqueous Dispersion (A) Having Curable Site) Reference Example 1 except that the composition of the charged monomers was changed as shown in Table 1. A fluororesin aqueous dispersion (A) having a curable site was prepared in the same manner as in.

In this case also, the ethylene supply conditions are the same as in Reference Example 1. The composition and the analytical values of the obtained dispersion are shown together in the same table.

[0088]

[Table 1]

<< Footnote of Table 1 >> CTFE: Abbreviation of chlorotrifluoroethylene HFP: Abbreviation of hexafluoropropylene VAc: Abbreviation of vinyl acetate VV-10: Abbreviation of vinyl ester of versatic acid having 10 carbon atoms BVE: Abbreviation of butyl vinyl ether CrA: Abbreviation of crotonic acid AGE: Abbreviation of allyl glycidyl ether DMAEMA: Abbreviation of dimethylaminoethyl methacrylate HBVE: Abbreviation of hydroxybutyl vinyl ether NV: Abbreviation of nonvolatile content (% by weight) MFT: Minimum film forming temperature ( Abbreviation for ℃) Dia: Abbreviation for average particle diameter (nm)

Reference Example 5 (Preparation Example of Aqueous Resin Dispersion (B) Having Curable Site) A 2-liter stainless steel reaction vessel equipped with a stirrer, a nitrogen inlet tube, a thermometer and a temperature controller was charged with nitrogen gas. After fully replacing the inside, 850 g of ion-exchanged water, 20 g of sodium dodecylbenzene sulfonate, 20 g of polyoxyethylene nonyl phenyl ether, phosphoric acid secondary as a pH buffering agent.
Add 10 g of sodium and dissolve. Next, 200 g of methyl methacrylate, 50 n-butyl acrylate
0 g, 150 g of acrylic acid, and 150 g of glycidyl methacrylate are charged. Then, the internal temperature of the reactor is raised to 55 ° C.

Next, at the same temperature, an aqueous catalyst solution (oxidizing agent) prepared by dissolving 5 g of potassium persulfate in 100 g of ion-exchanged water and 5 g of sodium formaldehyde sulfoxylate were added.
An aqueous catalyst solution (reducing agent) in which 100 g of ion-exchanged water is dissolved is dropped into the reaction vessel over 3 hours. After the addition of the aqueous catalyst solution, the temperature is maintained for 10 hours to allow the polymerization reaction to proceed. The pH during the reaction proceeded to 4.0. After completion of the reaction, the mixture is cooled to room temperature, 14% aqueous ammonia is added until the pH becomes about 7.0, and the mixture is taken out. The resulting dispersion is
50 non-volatile components having an epoxy group as a curable site
%, PH 7.0, the minimum film-forming temperature is 25 ° C., and the average particle size is 90 nm, which is a white aqueous dispersion. Hereafter (B
-1).

[0092]

[Table 2]

<< Footnotes in Table 2 >> MMA: Abbreviation of methyl methacrylate BA: Abbreviation of n-butyl methacrylate GMA: Abbreviation of glycidyl methacrylate DMAEMA: Abbreviation of dimethylaminoethyl methacrylate AA: Abbreviation of acrylic acid AMPS: Abbreviation of 2-acrylamido-2-methylpropanesulfonic acid HEMA: Abbreviation of 2-hydroxyethyl methacrylate BIEM: Abbreviation of isocyanate ethyl methacrylate / methyl ethyl ketone adduct NV: Abbreviation of non-volatile content (wt%) MFT: Minimum film forming temperature ( Abbreviation for ℃) Dia: Abbreviation for average particle diameter (nm)

Reference Examples 6 to 9 (Preparation Example of Aqueous Resin Dispersion (B) Having Curable Site) Same as Reference Example 5 except that the composition of the charged monomers was changed as shown in Table 2. By the operation of, an aqueous resin dispersion (B) having a curable site was prepared. The composition and the analytical values of the obtained dispersion are shown together in the same table.

[0095]

[Table 3]

Reference Example 10 (Preparation Example of Fluororesin Aqueous Dispersion Having No Curable Site) A 2-liter stainless steel pressure-resistant reaction vessel (autoclave) equipped with a stirrer, a nitrogen inlet tube, a thermometer and a temperature controller was used. After thoroughly replacing the system with nitrogen gas, 800 g of ion-exchanged water and 20 g of sodium dodecylbenzenesulfonate
g, polyoxyethylene nonyl phenyl ether 20
g and 10 g of borax as a pH buffer are added and dissolved. Next, 300 g of vinyl neodecanoate, 130 g of vinyl acetate, and 500 g of liquefied and collected chlorotrifluoroethylene are charged. Next, use ethylene gas 15k
Press in until g / cm ² is reached. The internal temperature of the autoclave is raised to 80 ° C. At this time, ethylene gas is adjusted so that the pressure in the system during the reaction is approximately 30 kg / cm ² . Then, at the same temperature, an aqueous catalyst solution obtained by dissolving 5 g of potassium persulfate in 200 g of ion-exchanged water is pressed into the reaction vessel for 3 hours. After the addition of the aqueous catalyst solution, the temperature is maintained for 10 hours to allow the polymerization reaction to proceed. The pH during the reaction proceeded at 3.5. During the reaction, the pressure in the system decreases as the monomer is consumed, but the pressure of the reaction system is maintained at 30 kg / cm ² by introducing ethylene each time. After completion of the reaction, the mixture was cooled to room temperature and 14% aqueous ammonia was added until the pH reached about 7.0, and 5% of a silicon-based defoaming agent (San Nopco Nopco 8034L) was added.
Add 1 g of the aqueous dispersion and stir well. Next, the unreacted gas is gradually taken out of the system and the system pressure is returned to normal pressure.

Then, the unreacted gas dissolved in the dispersion is distilled off under reduced pressure. The obtained dispersion is a white aqueous dispersion having a nonvolatile content of 48%, a pH of 7.0, a minimum film forming temperature of 29 ° C., and an average particle diameter of 82 nm. Hereinafter, this is referred to as (R-1).

[0098]

[Table 4]

Reference Examples 11 to 12 (Fluorine Resin Aqueous Dispersion Having No Curable Site, Preparation Example of Aqueous Resin Dispersion) The composition of the charged monomers was changed as shown in Table 1 or 2. Other than the above, an aqueous dispersion having no curable site other than the present invention was prepared by the same operation as in Reference Example 10 (in the case of fluororesin aqueous dispersion) and Reference Example 5 (aqueous resin dispersion). The composition and the analytical values of the resulting dispersion are shown together in the same table.

Examples 1 to 6 (blending of water-based curable resin composition) Fluorine resin aqueous dispersions (A-1 to A-4) having curable sites obtained in Reference Examples 1 to 4 and Reference Example 5 Aqueous resin dispersion having a curable site (B-1 to B-
Each of 5) was diluted to a nonvolatile content of 45% and then blended in the formulation shown in Table 3 to obtain an aqueous composition. Each of the obtained compositions was applied onto a glass plate with a 3 mil applicator and dried under the drying conditions shown in the table, and then various evaluation tests were carried out.

Further, in Example 6, a system in which the fluororesin aqueous dispersions are cured by the same solution is exemplified. The respective results are shown together in the same table.

[0102]

[Table 5]

<< Footnotes in Table 3 >> * 1 ......... In the examples, it is contained between the two components,
They were mixed so that the equivalent ratio of functional groups capable of reacting with each other was 1.

Comparative Example 1 is the object of Example 1 in which the functional group was removed from A-1. Comparative example 2
Is a compound obtained by removing a functional group from A-4, and
Is a target example of.

Comparative Example 3 is the composition of the two components of Example 1 from which the functional groups were removed, and is a target example of Example 1. * 2 ... BcAc is an abbreviation for butyl carbitol acetate.

The amount added is 2% with respect to the total amount of the dispersion. * 3 ... A 70% paste of titanium oxide was mixed so that the pigment volume concentration was 20%.

With regard to the one containing the pigment paste, "Stone viscosity" was adjusted to 75 KU by using "Boncoat 3750" [polycarboxylic acid type thickener manufactured by Dainippon Ink and Chemicals, Inc.]. And provided for the test.

* 4 ... Triethylamine was used as a curing catalyst, and 0.5% was added to the total amount of the dispersion. * 5: A (1 week drying at room temperature) B (20 minutes drying at 60 ° C, 1 week drying at room temperature) C (20 minutes drying at 100 ° C, 1 week drying at room temperature) * 6 ... Gel fraction: The dried film obtained on the glass plate was peeled off and immersed in acetone for 24 hours, after which the gel content of the film that remained without being dissolved in acetone was weighed and the initial It was expressed as a percentage of the weight of the dry film of.

* 7 ... Contamination resistance: 1 cm × 1 cm carbon paper is placed on the dry film obtained on the glass plate, the glass plate is placed on the carbon paper, and a weight of 2 kg is placed thereon.

Then, it is placed in a dryer at 80 ° C. and left for 20 minutes. Then, it is taken out, and the state of adhesion of dirt on the carbon paper on the dry film is observed.

A sample without any stain is marked with "⊚", and a sample with slight stain is marked with "○", and
The case where dirt was attached or the case where the carbon paper was not peeled from the dry film was evaluated as "x".

* 8 ... Accelerated weathering resistance: After an exposure test for 3,000 hours using a dew panel light control weather meter, the appearance of each coating film was visually determined.

The dry film was evaluated as "⊚" when no abnormalities such as discoloration or peeling were recognized, and when slightly recognized as blister or peeling was evaluated as "○", and the blister was entirely covered. Those that occurred and were significantly deteriorated were evaluated as "x".

[0114]

[Table 6]

Comparative Examples 1 to 3 Various aqueous dispersions (R-1 to R-3) obtained in Reference Examples 10, 11 and 12 were diluted to a nonvolatile content of 45%, and then listed in Table 3. A control aqueous composition was obtained with the formulation as described.

Next, various obtained compositions were coated on a glass plate with a 3 mil applicator and dried under the drying conditions shown in the table, and various evaluation tests were carried out. The results are shown together in the same table.

[0117]

[Table 7]

The coating films obtained by using the various fluororesin aqueous dispersions obtained in the present invention showed excellent performance in all tests.

[0119]

EFFECT OF THE INVENTION The fluororesin aqueous dispersion obtained by the present invention is capable of curing a fluoroolefin emulsion copolymer, which has been heretofore difficult, at a relatively low temperature, and has a stain resistance. And a coating film having weather resistance for a long period of time without deteriorating.

Claims (1)

[Claims] 1. An essential component comprising a fluororesin aqueous dispersion (A) having a curable site and an aqueous resin dispersion (B) having a functional group capable of reacting with the curable site of the fluororesin. A water-based curable resin composition, characterized by containing as.