WO2001044390A1 - Fluororesin coating composition of aqueous slurry dispersion type - Google Patents

Abstract

A fluororesin coating composition of the aqueous slurry dispersion type which is a slurry comprising an aqueous medium and, dispersed therein, particles of a thermosetting fluororesin composition which comprises (A) a thermosetting fluororesin comprising fluoroolefin units and having crosslinkable reactive groups and (B) a hardener capable of forming a crosslinked structure upon reaction with the crosslinkable reactive groups. The composition has satisfactory storage stability and can be easily applied. It can form through baking at low temperatures a coating film excellent in weatherability, surface smoothness, stain resistance, impact resistance, hardness, etc. Also provided is a process for producing the composition.

Description

 Akira Itoda slurry-like water-dispersion type fluorine-containing resin paint composition technology

 The present invention is based on low-temperature baking of a coating film that has good storage stability, is easy to paint, and has excellent weather resistance, surface smoothness, and stain resistance. The present invention relates to a slurry-like water-dispersible fluorine-containing resin coating composition which can be formed by coating and a method for producing the same. Background technology

 Fluororesin has excellent weather resistance and is used in forms such as powder coatings, water-dispersible coatings, and organic solvent-based coatings. Applications requiring weather resistance 粉体 Powder coatings are often used in applications where chemical resistance is required.

 As described in the official gazette of Japanese Patent Publication No. 52-5852, such powder coatings generally require a high temperature of 300 ° C or more after application. The baking is required, and only the base material that can withstand the baking temperature can be painted.

 Fluorine-containing resin powder paints that can be baked at a temperature of about 200 ° C are also known (Japanese Patent Publication No. 6-1104792). Since the average particle size of the powder coating particles is large (above about 40 / xm), round (concave and convex) force is generated on the coated film after coating, and surface smoothness is increased. It cannot be used for applications such as the required surface painting of automobiles and home appliances that are required.

In order to eliminate the land, it is considered to be effective to reduce the particle size of the resin particles.However, when the particle size is reduced, the powder containing fluorine is particularly required. In paint, particle blocking is likely to occur. Rather, the properties required for powder coatings, such as powder fluidity and painting workability, will be reduced.

 The present invention provides a low-temperature baking coating film that exhibits the same weather resistance as known fluorine-containing resin powder coatings and has excellent surface smoothness. It is intended to provide a fluorine-containing resin coating composition which can be obtained.

 The inventors of the present invention have conducted studies with the aim of solving such a problem, and as a result, the particles of the fluorine-containing resin composition having a small particle diameter have a slurry-like shape. By dispersing in a water-based medium, not only the above-mentioned problem can be solved, but also the storage stability and the thin film coating property are excellent, and the strength is strong. The present inventors have found that a coating composition capable of providing a coating film can be provided, and the present invention has been completed. Disclosure of the invention

 That is, the present invention relates to a thermosetting fluorine-containing resin (A) containing a fluoroolefin unit and a bridging reactive group, and the crosslinkable reactive group. Particles of a thermosetting fluorine-containing resin composition containing a hardening agent (B) capable of forming a bridge structure in response to the slurry are dispersed in an aqueous medium in slurry form. The present invention relates to a slurry-like water-dispersed fluorine-containing resin coating composition which is dispersed.

 The fluorine-containing resin composition particles have an average particle diameter of 0.1 to 35 m, preferably 0.5 to 30 / im, and are obtained. Preferably, the coating composition is baked at a temperature of 250 ° C. or lower to form a film.

As the fluorine-containing resin composition constituting the particles of the fluorine-containing resin composition, the heat-curable fluorine-containing resin (A) and the hardening agent (a) may be used. B) in a weight ratio in the range of 40/60 to 98/2, preferably a thermosetting fluorinated resin composition, and an aqueous medium. As a dispersion stabilizer for 100 parts by weight of water, 0.01 to 10 parts by weight of a surface active agent and / or a thickener is used. Those containing Z and Z or an organic solvent are preferred.

 According to the fluorine-containing paint composition of the present invention, the storage stability is good, the painting work is easy, the weather resistance, the surface smoothness, the stain resistance, and the like. A coating film that excels in chemical resistance, glossiness, moisture permeability, impact resistance, hardness, etc. can be formed by low-temperature baking. Best form for carrying out the invention Fluorine-containing resin composition dispersed in an aqueous medium in slurry form in the paint composition of the invention The particles contain a fluorine-containing resin containing a fluororefin unit. Such a fluororefine unit is, for example, tetrafluoroethylene (TFE), a trifluorene (CT)

FE), trifluoroethylene, vinylidene fluoride (VdF), hexafluoropropylene (HFP), and penyfluoro The structural units that are derived from the fluorinated monomers, such as the mouth propylene and the fluorene, are created.

As the other structural unit of the fluorine-containing resin, an ethylenically unsaturated compound is preferable. For example, an ethyl vinyl ether, For example, vinyl ether, small vinyl ether, isobutyl vinyl ether, cyclohexyl vinyl ether, etc. Luxyl vinyl ethers; ethyl phenyl ether, phenyl ether, petilary ether, isobuty Real-Rule — Al, N-cyclohexyl-Rel-Release, etc., Alkyl-Rear-Ele-Lates, etc .; Pillary Esters, Petilary Esters Alkyl esters, such as steles, isobutyryl esters, cyclohexyl esters, etc .; ethylenes , Propylene, butylene, isobutylene, and other alkenes; acrylic acid, methyl acrylate; ethyl acrylate, Pillar clear rate, Butyl clear rate, Isoclear clear rate, 2—Electrile rate To the female creat, creator creat, butyl creat, isobuter creat, and 2 — ethyl Acrylic acid or esters of methacrylic acid, such as xylile methacrylate, or partially hydrofluoric acid. On two or more is Ru is Oh-up we had one or substituted of compounds, etc.

 The composition ratio of these structural units differs depending on the combination, and the force S, the fluororefin unit, which is not particularly limited, In addition to the inclusion, the resulting fluorine-containing resin

Since the film must be formed at a temperature of 0 ° C or less, the fluorine-containing resin must have a softening point of 250 ° C or less. And the melt flow rate (MFR) measured at a temperature of 250 ° C or less from the viewpoint of melt flowability during baking and 1

The condition of 0 g / 10 minutes or more must be satisfied.

 Regarding the softening point, the lower the level, the lower the storage stability, and the higher the level, the lower the surface smoothness of the coating. 100 ° C., particularly preferably 30 to 100 ° C., is preferred.

In addition, the fluorine-containing resin contains a fluoroolefin unit of preferably 30 mol% or more, particularly preferably 45 to 90 mol%. When the fluorine content is 10% by weight or more, the characteristics of the fluororesin such as weather resistance and chemical resistance can be obtained. It is preferable from the point of view.

 A particularly preferred fluorine-containing resin is a thermosetting fluorine-containing resin further containing a bridging reactive group. Examples of the bridging reactive group include a hydroxyl group, a carboxyl group, an amino group, a merylcaptoglycidylyl group, and an isocyanate group. In addition, active halogen atoms such as bromine and iodine are exposed.

 The method of introducing such a bridging reactive group into a fluorine-containing resin is based on a method of co-polymerizing a monomer having a bridging reactive group, or a method of copolymerizing a monomer having a bridging reactive group. There are various methods such as a method of decomposing a part, a method of reacting a compound that gives a bridging reaction group to a reaction group of a copolymer, and the like. It is.

Examples of a copolymer into which a suitable bridging reactive group can be introduced by a copolymerization method include, for example, a hydroxyl group, a carboxyl group, and an epoxy group. Monomers that have a xyl group or have a group that can be converted to their reactive groups, and are shared with fluorophores Monomers with double bonds that can be polymerized are removed. Specific examples include hydroxyethyl vinyl, hydrochloride hydroxyvinyl ether, and hydroxybutyryl vinyl. Hydroxys such as ethers, hydroisomers, vinyls, ethers, heads, etc. Alkyl vinyl ethers; hydroxyvinyl acetate, vinyl hydroxypropionate, vinyloxyhydroxybutyrate Hydoxy, vinyl valerate, vinyl hydroxy butyrate, vinyl hydroxy hexyl carboxylate, etc. Esters between hydroxycarboxylic acid and vinyloxycarboxylic acid; hydroxyethyl alcoholic ester -Hydroxy-Proxy-Rail-Ether, Hydroxy-B-Hy-R-A-R Ether, head Hydroxylalkyl ethers such as mouth xylochel ethers; Hydroxylaryl ethers STELL, HYDROXY PROXY LIBRARY ESTELLIRE, HYDROXY BUSINESS RALLY ESTELL, HYDROXY SERVER Hydroxyl esters such as esters and hydroxyl esters, etc .; 2—Hydroxy echici Lucrrate rate, hydroxyproxy rate, 2-hydroxylmeter meter rate rate, hydroproxy rate Acrylic acid or methacrylic acid, such as dimethyl acrylate, and hydroxyalkyl esters of these acids; Tsu element was one or substituted of compounds, etc. are on two or more is Ru been Oh up, et al. One or more of these monomers may be selected and used as a co-monomer for introducing a hydroxyl group.

Comonomers having a hydroxyl group are, for example, acrylic acid, maleic acid, itaconic acid, fumaric acid, Such as anhydrous fumaric acid, crotonic acid, maleic acid, anhydrous maleic acid, and pendecylenic acid; Fluoro-substituted monomers, such as perfluorobutanoic acid, and aryloxy-propionic acids, such as aryloxypropionic acid Such as character ethers are required. Examples of the co-monomers having a glycidyl group include, for example, dalycidil (medium) acrylate and glycidyl virile. Ethers, grocery / grilled ethers, etc. are created. Examples of comonomers having an amino group include, for example, amino aminovinyl ether and amino aminoalkyl ether. Etc. are exterminated. Examples of the comonomer having an amide group include (meth) acrylamide, methylol acrylamide, and the like. It is terrible. Examples of the comonomer having a nitrile group include: Acrylonitrile, for example, is required. Comonomers having an isocyanate group include, for example, vinyl isocyanate, and isocyanate clear , Etc. are exacerbated. Comonomers having an active halogen group include, for example, vinyl chloride, vinylidene chloride, and the like.

 Copolymers for the introduction of bridging reactive bases are particularly vinyl-based because of their excellent copolymerizability with fluororefin. It is preferable to employ an ether or ethereal compound of the phylline type.

 In addition, as a method for decomposing a part of the fluorine-containing resin, a monomer having an ester group that can be decomposed with water after polymerization is copolymerized. An example of a method for producing a carboxyl group in a fluorine-containing resin by hydrolyzing a copolymer after the compounding is described. It is. In addition, in the direct hardening reaction without performing the ester hydrolysis in this way, the bridge connection is formed by the ester exchange reaction. It can also be done.

 As a method for reacting a compound that gives a bridging reactive group to a fluorine-containing resin, for example, a hydroxyl-containing fluorine-containing copolymer is used for the method of reacting the compound. A method of introducing a carboxyl group by reacting a divalent carboxylic acid such as waterless succinic acid and the like is preferably employed. can do .

From the above points, examples of the thermosetting fluorine-containing resin (A) include, for example, tetrafluoroethylene and ethylene Z-hydrogen. Xibutyl vinyl copolymer, tetrafluoroethylene / ethylene / hexafluoropropene Z hydro Kisuvyl vinyl ether copolymer, tetrafluoroethylene mouth Ethylene z To ethylene xfluoropropylene Z Droxipyl vinyl ether Z-vinyl benzoate copolymer, tetrafluoroethylene Z ethylene Z Propylene Z Hydroxyethyl Propylene copolymer, Tetrafluoroethylene Z Ethylen Z Hexafluoro Propylene z Hydroxybutyru vinyl ether z Cyclic hexyl vinyl ether Copolymers, tetrafluoroethylene Ren Z Ethylene Z Hexafluoropropyl Z Hydroxybutyruberyl Z 4 — t — Butyl benzoic acid vinyl Copolymer, tetrafluoroethylene z ethylene

Z-Propylene Z Hydroxy-butyral vinyl ether copolymer, black mouth Trifluoroethylene z-cyclohexylvinyl Ruthele z Hydroxy butyl vinyl ether copolymer, chlorotriflerole mouth Ethylene z Cyclic hexyl vinylilyl ether Examples include butyr vinyl ether hydroxy hydroxy butyral vinyl ether copolymers.

 When a thermosetting fluorine-containing resin (A) having a crosslinkable reaction group is used as the fluorine-containing resin, the crosslinkable reaction group is reacted with the frame. The hardener (B) that forms the bridge structure is incorporated.

As such a hardener (B), for example, a block isomer obtained by blocking an isocyanate compound with a blocker. The netted doll is removed. Isochronate compounds include, for example, isoholonite, tri-range isocyanate, and xylene-relate. Ports, such as the printer's edge-isolated components, 4,4'-diphenyl-methylene-isolated components, and hexamethyl-diene-isolated components. Lithocyanate conjugates and their multivalent alcohols such as dimers or trimers, trimethylolpropane, etc. An example is a modified polyisocyanate compound and the like, and as a blocking agent, for example, ε It can be used to power programs, phenols, benzyl alcohol records, and methyl ketoxims. Preferably, the compound is a solid compound at room temperature.

 Aliphatic dichloride groups such as cacao, fumaric acid, succinic acid, adipic acid, azelanic acid, sebacic acid, dodecane diacid, etc. Acids: Acids such as water-free fluoric acid, water-free trimellitic acid, water-free pyromellitic acid; water-free; acid value of 10 to 30 Omg glass with KOH Polyester resin or acrylic resin having a transition temperature of 30 to 120 ° C and a number average molecular weight of 100 to 150 Resin; dithiocyanamide or cyanide diamide derivative; imidazole or imidazole derivative; dibasic dihydric acid Amine compounds such as zid, diaminophenyl methane, and cyclic amidine compounds; melamin resins; diglyceryl terephthalate Gil Estel, Para Oxy benzoic acid diglycidyl ester, triglycidyl isocitrate, spiroglycol cholesterol Glycidyl compounds such as toluene, hydantoin compounds, and alicyclic epoxy resins;

1, 4 1 VIS 2 '— Hydroxyloxy benzene, bis □ Kissile terrefu evening rate, styrene relay Alcohol copolymer, spiroglycol, tris 2 — hydroxyethyl isocyanurate, hydroxyl value 10 to 300 mg Polyester resin or glass whose KOHZ g has a glass transition temperature of 30 to 120 ° C and a number average molecular weight of 100 to 1500 Examples include hydroxyl group-containing compounds such as acrylic resins. Such a hardener is preferably a compound which is solid at room temperature.

In the thermosetting powder coating composition of the present invention, the thermosetting property The weight ratio (A) / (B) of the fluorine-containing resin (A) to the curing agent (B) is 40/60 to 98/2, preferably 50/50 to 50/50. It is in the range of 9 7 Z 3.

 One of the features of the fluorine-containing resin coating composition of the present invention is that the powder-based coating contains particles of the fluorine-containing resin composition having a small particle size that would cause blocking. Is dispersed uniformly in an aqueous medium to form a slurry-like paint composition.

 In the present invention, the term "fluorine-containing resin composition" and "particles of the fluorine-containing resin composition" refer to a mixture of a fluorine-containing resin and a hardening agent. Compound (particles), and mixtures (particles) of these with optional additives such as facial pigments to be described later.

 The average particle size of the fluorine-containing resin composition particles is 0.1 to 35 m, preferably 0.5 to 30 m, as described above. Furthermore, it is preferred that the maximum diameter of the particles contained is no greater than 70 / m. If the average particle size is larger than 35 wm, the storage stability of the coating composition will be reduced, and the surface smoothness of the obtained coating film will be significantly increased. (Rounds are produced). If the average particle size is smaller than 0.1 ^ m, more energy will be required for fine pulverization, and the paint will be dulled during coating. It becomes easier.

As the aqueous medium which is a dispersion medium in the paint composition of the present invention, water alone may be used, but it is possible to obtain a stable slurry state by obtaining a stable slurry state. It is preferable to add a small amount of a dispersion stabilizer in order to improve the qualification and painting workability. Examples of the dispersion stabilizer include surfactants, viscosity modifiers, and organic solvents, which are used alone or in combination of two or more. Add them together. The amount is 0.01 to 10 parts, preferably 0.05 to 3 parts, and particularly preferably 0.05 to 1.0 part with respect to 100 parts of water. It is. If the amount of the dispersion stabilizer is too large, the surface smoothness and water resistance of the obtained coating film decrease. The dispersion stabilizer may be used before or after the fluorine-containing resin composition particles are injected into the aqueous medium, and depending on the type of stabilizer, the fluorine-containing resin may be used in advance. It may be mixed in the composition particles.

 Examples of surface active agents used as dispersion stabilizers include cationic surface active agents, anionic surface active agents, and nonionic surface active agents. Known substances such as activators, amphoteric surfactants, and water-soluble polymers can be used alone or in admixture of two or more.

 Specific examples of nonionic surface active agents include, for example, sorbitan fatty acid ester, and poloxyethylene solylene resin. Fatty acid ester, polyoxyethylene sorbitol Fatty acid ester, polyoxyethylene fatty acid ester, polio Xylene ethylene glycol ether, glycerin fatty acid ester, propylene glycol fatty acid ester, polio Xylene ethylene cast oil, polyoxyethylene alkyl phenyl ether, alkyl phosphate ester, polyoxyl It is possible to increase the strength such as ethylene phosphate ester. Specific examples of anionic surface active agents include, for example, alkyl sulfate ester salts, and polyoxyethylene alkyl ethers. Esters such as sulfuric acid ester, alkylsulfoconoate, and N-acylzalcosinate are available. Specific examples of the cationic surface active agent include, for example, quaternary ammonium salts and pyridinium salts.

Dispersion stability of fluororesin composition particles 非 Because of the low foaming of slurry and the superior performance of the resulting coating film, Preference is given to ionic surfactants, especially those having an HLB value of from 8 to 18. Thickeners used as dispersion stabilizers include methylcellulose, ethylcellulose, and hydroxyxylcellulose. Cellulose-based water-soluble resins such as polyvinyl alcohol, polyethylene glycol, polyethylene oxide, etc. Polyethylene-based water-soluble resin; methyl vinyl ether, maleic anhydride copolymer, ethylene-free water-maleic acid copolymer, Maleic anhydride copolymer-based water-soluble resin such as styrene-free water-maleic acid copolymer; acrylonitrile-containing ammonium salt; Mint salts, Alkali metal salts, etc .; Bentonite; Polyvinylpyrrolidone; Alginate; Polyacrylyl Mid or its hydrolyzate; natural water-soluble resin such as casein or gelatin; hardly water-soluble inorganic system such as calcium phosphate Dispersants, etc. may be removed.

 Organic solvents can also be used as dispersion stabilizers. Specific examples include ketones such as, for example, acetate; methanol, ethanol, n-propanol, isopropanol. , N — alcohol, isobutanol, sec-alcohol, tert — alcohol, phenol, etc. ; Methyl sorbet, ethyl yl cello sorb, isopropyl sorbo, butyl sorb, sec-butyl sorb Cellosolves, etc .; propylene glycol methyl terelite, dipropylene glycol methyl terelite, propylene Lenght-reel conductors such as methyl alcohol ether acetates, etc .; ethylene glycol reticles Solvents such as ethereal acetate, toluene, xylene, and tetrahydrofuran are exuded, but the boiling point is higher than that of water. Those having a high value are preferred because of the good film-forming properties of the coating film.

The coating composition of the present invention basically comprises a fluororesin composition particle. And a water-based medium, to which the above-mentioned hardener and / or dispersion stabilizer have been suitably added, but which are usually used in coating compositions. Various additives to be added and mixed may be mixed. Such additives include cosmetics and other resins such as non-fluororesin-containing and non-fluororesin-containing non-fluorinated resin. Fats, hardening catalysts, flame retardants, flow aids, defoamers, sedimentation inhibitors, antifungal agents, preservatives, ultraviolet absorbers, thermal degradation inhibitors, etc. can give .

 These additives may be added to the fluorine-containing resin composition particles in advance depending on the nature or purpose thereof, or may be added to the aqueous medium. It may be added to the coating composition, or may be added to the coating composition at the time of coating.

 Pigments include, for example, inorganic coloring pigments such as titanium oxide, red iron oxide, yellow iron oxide, carbon black, etc .; Organic coloring cosmetics such as blue, phthalocyanine green, quinacridone red cosmetics, and isoindolinone yellow cosmetics; Constituent cosmetics such as luk, silica and calcium carbonate; metal powders such as aluminum powder, stainless steel powder; and my powder. One or more species are specified. In addition, it is also preferable to incorporate an anti-reflective agent represented by pyrophosphate or tripolyphosphate. Of these, the combination of a rutile-type titanium oxide and other coloring pigments is preferred because of its excellent pigment dispersibility and weatherability.

The content (concentration) of the fluorine-containing resin composition particles in the paint composition of the present invention is from 20 to 70% by weight, preferably from 30 to 60% by weight. %. If the weight is lower than 20% by weight, the solid content of the paint will be low and the viscosity will be low, so the storage stability of the paint will be significantly reduced. In addition, liquid dripping of the coating film at the time of coating It is easy to grow. If the content exceeds 70% by weight, bubbles are apt to be contained in the paint, and the paint tends to agglomerate, and the viscosity of the paint increases. Coating workability becomes difficult. The content (concentration) of the above-mentioned fluorine-containing resin composition particles includes solid components such as pigments and hardeners.

 The slurry-like fluororesin coating composition of the present invention is characterized in that the resin particles can contain a curing agent, a pigment, and other additives in the resin particles. Because it is suspended in water, it can be easily re-dispersed even if a sediment occurs, and the pulverized composition after dry mixing can be dispersed in water In this respect, it is different from the conventional water-dispersible fluorinated resin composition.

 The slurry-like fluorine-containing resin coating composition of the present invention comprises, for example, (1) preliminary mixing of the fluorine-containing resin and other additives by a dry blending method. Then, it is pelletized and crushed to obtain particles of the fluorine-containing resin composition having an average particle diameter of 0.1 to 35 m. If necessary, various kinds of particles are added. By mixing with an aqueous medium with stirring and mixing to form a slurry, or (2) a dry mixing method of mixing a fluororesin-containing resin with other additives. The mixture is preliminarily mixed, then pelletized, further coarsely pulverized, and then mixed with an aqueous medium, and has an average particle diameter of 0.1 to 3 in the aqueous medium. Wet pulverizing to a slurry of 5 m or less and slurrying. (3) Preliminary mixing of fluororesin containing resin and other additives in organic solvent , After distilling off the solvent, pulverize to an average particle size of 0.1 to 35 m, and then disperse it in an aqueous medium to form a slurry. It can be manufactured more. In the premixing method in these methods, (1) and (2) above are dry mixing methods, and (3) is a wet mixing (solvent type) method. It is legal.

Of these production methods, the fluorine-containing resin composition was Thermosetting curable fluororesin (A) containing a fluororefin unit and a bridging reactive group, and a bridge structure formed by reacting with the bridging reactive group. When using a fluorinated resin composition comprising a hardener (B) that can be formed, the preliminary mixing must be performed by the dry mixing method (1). ) Or (2), especially the production method by the wet pulverization method described in (2) above, makes it easy to adjust the particle size, and provides a uniform slurry. It is preferable because it can be manufactured and gives a good appearance of the coating film.

 In this wet pulverization method, a dry blender such as a helical mixer or a high-speed mixer is used for the preliminary dry blending. It is suitable, and after that, it is melt-kneaded with a twin-screw extruder or the like and then coarsely ground. For coarse crushing, use a crusher such as a high-speed impact crusher or a high-speed spin crusher, and the average particle size is more than 35 m, preferably. Or coarsely pulverized particles of about 40 to 100 m. A wet mill such as a sand mill or wet jet mill can be used for the wet milling.

 The slurry-containing fluororesin paint composition of the present invention is applied to a conventional solvent-type paint or water-based emulsion-type paint as a method of applying the composition. You can use any of the painting methods, such as the spray method, the dividing method, and the roll coating method. Of these, the spray method is preferred because of its superiority in productivity, coating workability, and smoothness of the coating film.

After applying the paint, it is dried and baked to form a coating film. The baking temperature is above the softening point of the fluorine-containing resin and within a temperature range of 250 ° C or lower, and depends on the type of the fluorine-containing resin, the type of the hardening agent, and the additive. It is appropriately selected according to the heat resistance temperature of the agent. Drying before baking may be drying at a low temperature, but may be performed at a temperature of 140 ° C or less, preferably in a temperature range of 80 to 120 ° C. To heat or blow dry air, etc. Is preferred.

 In particular, the coating composition of the present invention is applied to a base material, half-baked at a temperature of 140 ° C or lower to remove water, and then the above-mentioned half-baking temperature is applied. The two-step baking method, which is higher than the softening point of the fluorine-containing resin and is higher than the softening point of the resin and in the range of 250 ° C or lower, is based on the heat- It is preferable from the viewpoint of absorbing the difference in expansion rate and preventing the coating film from cracking. After being dried at ambient temperature, dry air at 80 to 120 ° C is blown to remove water (semi-baked). The method of baking in the temperature range of 30 to 200 ° C is optimal.

 The coating composition of the present invention can be applied to a base material having low heat resistance such as a plastic base, a rubber base, or a natural base. Suitable for coating on heat-resistant base materials such as mix bases and metal bases. Particularly suitable metal substrates include, for example, iron, aluminum, stainless steel, copper, zinc or stainless steel, and brass. All kinds of alloys are required.

 The present invention also relates to a coating obtained by applying the coating composition of the present invention to a base material and forming a film. The coating film obtained is excellent in surface smoothness and luster, moisture resistance, impact resistance, hardness, and can be obtained from a conventional fluorine-containing resin powder paint. It has weather resistance and contamination resistance that is not inferior to that of a coated film.

 In particular, as the painted objects on which the effects of the present invention can be expected, there are, for example, the articles listed below, but they are not limited to these. What is it?

Building materials:

Aluminum sashes, fences, P doors, balconies, handrails, area grids, shutters, doors, glass, panel households Products (electrical products, etc.): Basket, saucer, various cleaning devices, range, range hood, air-conditioning equipment, cooling and heating equipment, washing machine, ventilation fan, machine

Security equipment:

 Fire extinguishers, fire extinguishing equipment, fire hydrant poles, fall prevention nets, safety shoes

Aircraft:

 Exterior of airplane

Ship ：

 Outboard motor, screw, radar, bottom

Vehicles (automobiles, trains, etc.):

 Handles for exterior and interior parts, wipers, bumpers, holes, wheels, brakes, sunroofs, doors, doors, etc. Drives, drive shafts, rail joints, vault nuts

Other metal products:

 This product is used for bombs, drum cans, pail cans, brewing tanks, containers, desks, chairs, various kinds of interior parts, furniture and accessories. The present invention will be described more specifically based on synthetic examples and practical examples, but the present invention is not limited to these examples.

Synthesis example 1

A stainless steel steel scraper with a capacity of 400 m1 is charged with 760 g of deionized water and 7 g of potassium carbonate. Thereafter, nitrogen pressurization and degassing were repeated three times to remove dissolved oxygen. Under reduced pressure, chlorofluoroethylene (HCFC 14 lb) 572 g, hexafluoropropylene 340 g, 4-hydroxy Charge 3 g of butyl vinyl ether 35 ° C The temperature was adjusted to In addition, 0.88 MPa a · G (9 kgf / g) of tetrafluoroethylene (Z) ethylene in a monomer mixture with a molar ratio of 82/18 mol% of ethylene cm ² -G), and after adjusting the pressure, 4 g of cyclohexane and 25% of isobutyrylruboxide-25% of oxide. The reaction was initiated by charging 24 g of the solution. Since the pressure drop occurs along with the reaction, the tetrafluoroethylene Z ethylene Z The mixed monomer having a ratio of 9 Z 16 mol% was continuously supplied, and the pressure in the tank was kept at 0.88 MPa a'G (9 kgί / cm ² -G). Every 6 hours, 4—hydroxy butyral vinyl ether 1.5 g and 25% of isobutyryl peroxyside 25% flon 2 2 5 After reacting for 12 hours while adding 12 g of the solution, the inside of the tank was returned to normal temperature and normal pressure, and the reaction was terminated. The obtained solid was washed and dried to obtain a thermosetting type fluorine-containing copolymer (152 g) as a white powder. When the obtained fluorine-containing copolymer was analyzed by ¹⁹ F—NMR ^ H—NMR and elemental analysis, tetrafluoroethylene 3 was obtained. 4 mol%, ethylene 47 mol%, hexafluoro mouth propylen 12 mol% and 4 — Hydroxybutyl vinyl It is a copolymer consisting of 7 mol% ter, and its glass transition temperature is 48 ° C, and the MFR measured at 140 ° C is 56 gZ 10 minutes. (Hereinafter referred to as “Resin A-1”). Synthesis example 2

A stainless steel pressure-resistant reactor with a stirrer with a capacity of 300 m1 is equipped with a 100 g of t-rubber and 100 g of cyclone. Nil ether (c-HXVE) 106 g, isobutyl vinyl ether (iso-BVE) 60 g, 4-hydroxypeptide vinyl Ether (HBVE) 165 g, carbonic acid Charge 5 g of calcium and 0.5 g of azobisisophthalonitrile (AIBN), and dissolve dissolved air by solid nitrogen degassing with liquid nitrogen. Removed. Then, 330 g of trifluoroethylene (CTFE) was introduced, the temperature was gradually increased, and the solution was stirred under agitation while maintaining the temperature at 65 ° C. The reaction was continued, and after 10 hours, the reactor was cooled with water to stop the reaction. After cooling to room temperature, the unreacted monomer was pulled out, and the reaction was terminated. Then, the mixture was heated to 60 ° C., and the dispersion medium was removed under reduced pressure of 1 mmHg for 24 hours to obtain a thermosetting type fluorine-containing copolymer. The obtained fluorine-containing copolymer was analyzed by ¹⁹ F-NMR, 'H-NMR, and elemental analysis methods. As a result, it was confirmed that the macromolecule trifluoroethylene was obtained. 49 mol%, cyclohexyl vinyl ester 26 mol%, isobutyl vinyl ether 9 mol%, and 4 — hydro It is a copolymer consisting of 16 mol% force and has a glass transition temperature of 43 ° C, measured at 140 X :. The MFR was 12 g Z 10 minutes (hereinafter referred to as “resin A-2”).

Manufacturing example 1

80 parts of a fluorine-containing resin powder obtained by pulverizing the resin A-1 synthesized in Synthesis Example 1 with an impact hammer mill and a hardener (Hyurires Co., Ltd.) 20 parts of IPDI-ADDUCT B1530 manufactured by Mitsui Chemicals, Inc. are uniformly mixed for about 1 minute with a drive blender (Henschel Mixer manufactured by Mitsui Chemicals, Inc.). After being combined, the mixture was melted and kneaded at a temperature of 125 ° C by a twin-screw melt kneader (Prism 16 mm twin-stretcher). After cooling, the mixture is coarsely crushed at room temperature for 3 minutes using a universal crusher (made by IKA), and further passed through a wire mesh with an opening of 75 m (200 mesh). And then heat-curable fluorine-containing resin powder (average particle size: 45 ^ m. 1 1)).

Manufacturing Examples 2 to 4

 The resins and hardeners shown in Table 1 were used, and the additives shown in Table 1 were further mixed and melt-kneaded in the same manner as in Production Example 1 to obtain a mixture. The powder was pulverized to prepare a thermosetting fluorine-containing resin composition powder (powder B-2 to B-4).

 The titanium oxide oxidized in Production Example 3 was a rutile-type titanium oxide (Dipuron R-960, an average particle size of 35%) manufactured by Dupont. m)) and Blue 9 is a calcined pigment (average particle size l ^ m) manufactured by Shefad, and the ultraviolet absorbing agent combined in Production Example 4 is It is TINUVIN 900 made by Bagaygi

1

実施 例 1

Example 1

Thermosetting thermosetting fluororesin composition powder prepared in Production Example 1 (B-1) 50 parts, water 50 parts, Surfactant 1 (Power Racer 188-A, nonionic surface activity manufactured by Sannopco, Inc.) 2 parts) and glass beads (1.5 mm diameter) 150 parts into a desktop sand mill (manufactured by Kansai Paint Co., Ltd.). The mixture is wet-milled for 30 minutes with a mesh of 75 ^ m opening (200 mesh), and the glass beads are removed by filtration. The average particle size is 2 m. A slurry resinous paint composition of a fluorine resin was obtained.

 The storage stability of this slurry-like coating composition was examined by the following method. Table 2 shows the results.

 (Storage stability)

 After leaving the test paint at 40 ° C for 1 power month, the condition of the paint is visually observed and evaluated based on the following criteria.

A: No sediment was found, and the uniform slurry was maintained.

 B: A small amount of sediment is observed, but it returns to a uniform slurry by lightly stirring.

 C: Some of the sediment was in a lump and could not be crushed even with stirring.

 D: Most of the resin particles have settled out, forming hard lumps.

 The resulting coating composition was spray-applied on a chromium-treated aluminum plate, and was preliminarily dried at room temperature for 10 minutes. After that, dry air at 120 ° C was blown for 20 minutes and semi-baked to remove water. The film was heated at 190 ° C for 15 minutes and baked to obtain a coating film having a thickness of about 35 ^ m.

The surface smoothness, weather resistance, lead hardness, impact resistance, and luminosity of this coating film were examined by the following methods. The results are shown in Table 2. (Surface smoothness)

 Evaluation is based on the degree of distortion of the fluorescent light when the fluorescent light is projected on the surface of the coating film and observed.

A: There is no distortion (mirror surface).

B: It is just distorted.

C: There is a noticeable distortion.

 ( Weatherability)

 The aluminum plate with the coating film formed on it was tested for acceleration and weathering using an Ionosaki, Iwasaki Electric Co., Ltd. After the test has been performed for 1000 hours, the appearance of the coating film (whether cracking or blistering has occurred, etc.) is visually observed. Preference is given to those with no abnormal appearance.

 ( Pencil hardness )

 Check the pencil hardness according to JIS K540. (Impact resistance)

 A A M A (American Architectural Manuiacturers Association) After performing a falling ball test in accordance with 605, a tape peeling test is not performed, and evaluation is based on the following criteria. 〇: No cracking or peeling was observed on the coating film.

X: Cracking and peeling of the coating film are observed.

 (Glossy)

Using a painted plate made by the same method as the stain resistance test described above, a mirror reflection angle of 60 degrees was measured in accordance with JISK540.6.7.60. Measure .

Example 2 to 10

Except that the powder, water, and surfactants shown in Table 2 were used in the amounts shown in the same table, the slurry-like hydrofluoric acid of the present invention was used in the same manner as in Example 1. A resin coating composition was prepared and was further treated as in Example 1. The aluminum plate was painted in the same way. Table 2 shows the storage stability and physical properties of the obtained paint composition.

 The surfactant used in each of the examples is as follows.

Surface active agent 1: Color noise 1 8 8 — A, non-ionic surface active agent manufactured by Sannobuco

Surfactant 2: SN Weight 3666, non-ionic surfactant produced by Sannopco

Surface active agent 3: SN Dispersant 507, an anionic surface active agent manufactured by SANNOPCO

Surfactant 4: Nobuco Snow 4 ° C, an anionic surface active agent manufactured by San Nopco

Surfactant 5: SN Dissolvent 504, an anionic surfactant from Sannopco

Example 1 1

 In Example 1, the mill for fine grinding was replaced with a wet jet mill (PRO4-15-5-8 manufactured by Genus). Then, the slurry-like fluorine-containing resin coating composition (the average particle diameter of the fluorine-containing resin composition particles of 0.3 m) of the present invention was prepared. The aluminum plate was painted in the same manner as in Example 1. Table 2 shows the storage stability and physical properties of the obtained paint composition.

Example 1 2

In Example 1, the same results were obtained by shortening the pulverization time of the desktop sand mill and setting the average particle diameter of the fluororesin composition particles to 12 / im. In the same manner, the slurry-containing fluororesin coating composition of the present invention was prepared, and then applied to an aluminum plate in the same manner as in Example 1. did . Storage stability of the obtained paint composition Table 2 shows the coating properties.

Comparative Example 1

 The fluororesin-containing composition powder (B-1) prepared in Production Example 1 is not dispersed in water, but is left in the form of a powder coating as it is. Electrostatic coating on the aluminum plate and baking at 190 for 15 minutes to give a comparative coated plate with a coating of about 45 m thickness The film was manufactured and the physical properties of the coating film were measured in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 2

In Example 1, except that the desktop sandmill was not ground, a slurry-like fluororesin paint for comparison was made in the same manner. The composition was prepared and further applied to an aluminum plate in the same manner as in Example 1. Table 2 shows the storage stability and coating film properties of the obtained coating composition.

Table 2

 Example Example Comparative Example

1 9 Q r.

 «3 Λ 7« q 1 Γ) 1 1 1 2 1 9

 R—— 1 50 50 50 50 50 50 50 50 50 1 00 50

B— 2 50

 B— 3 50

 B-4 ο υ

 zj 50 50 50 50 1 00 200 50 50 50 50 50 50 50 涂

 Surfactant

Fee

ί says 1 2 2 2 2 2 2 2 2 2

Thing 3 2

 4 0.5

 5 0.5

 1 1 q of fluorine-containing resin composition particles

 o 9 n 1 o

 U

 Average particle size (μm)

 Storage stability A A A A B C B C c C A c D Surface smoothness A A A A A A A B B B A B c C

'Coating weather resistance good good good good good good good good good good good good good good good good pencil hardness 2H H 2H H 2 H 2H H H H H H H F F

Gloss 7 1 65 66 59 64 73 68 62 62 64 65 60 40 40 Film thickness (μm) 35 35 35 35 35 35 35 35 35 35 35 35 35 70 70

Industrial availability

 According to the present invention, a coating film having good storage stability and easy coating work, and excellent in weather resistance, surface smoothness, stain resistance and the like can be obtained. It is possible to provide a slurry-like water-dispersed fluorine-containing resin coating composition which can be formed by low-temperature baking.

Claims

Scope of the invention The thermosetting and durable fluorine-containing resin (A) containing a fluororefin unit and a crosslinkable reactive group reacts with the crosslinkable reactive group to form a crosslinked structure. Wherein the particles of the thermosetting fluorine-containing resin composition containing a curing agent (B) capable of forming a polymer are dispersed in an aqueous medium in a slurry state. A fluorine-containing resin coating composition.  The fluororesin composition particles have an average particle size of 0.1 to 35 m, and the coating composition is baked at a temperature of 250 ° C or lower to form a film. The coating composition according to claim 1, wherein the coating composition is possible.  The above-mentioned fluororesin composition comprises a thermosetting fluororesin (A) and a curing agent (B) in a weight ratio of 40Z60 to 98. The coating composition according to claim 1 or 2, which is included in the range of / 2.  The aqueous medium contains 0.01 to 10 parts by weight of a surfactant and / or z or a thickener and / or Z as a dispersion stabilizer with respect to 100 parts by weight of water. The coating composition according to any one of claims 1 to 3, further comprising an organic solvent.  The coating composition according to any one of claims 1 to 4, wherein the fluorine-containing resin composition particles have an average particle size of 0.5 to 30 m. A thermosetting fluorinated resin (A) containing a fluorinated fin unit and a crosslinkable reactive group, and a curing agent capable of forming a crosslinked structure by reacting with the crosslinkable reactive group ( B) is premixed by a dry mixing method, pulverized, and then dispersed in an aqueous medium. The coating composition according to any one of Items 1 to 5 Manufacturing method of the product.  After applying the coating composition according to any one of claims 1 to 5 to a substrate, and half-baking at a temperature of 140 ° C or less to remove moisture, A coated product obtained by baking at a temperature higher than the half-baking temperature and at a temperature not lower than the softening point of the fluorine-containing resin and not higher than 250 ° C.