JP3237276B2 - Cold-curable fluororesin aqueous coating composition and article coated with the composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful cold-setting fluororesin aqueous coating composition and an article coated with the cold-setting fluororesin aqueous resin composition. More specifically, the present invention is based on a fluoroolefin and a specific formyl group-containing ethylenic monomer such as crotonaldehyde and / or alkenal and, if necessary, also based on a crosslinkable monomer. An essential component is an aqueous dispersion of a fluororesin obtained by copolymerizing monomers, and hydrazine and / or a compound having at least two hydrazyl groups in one molecule. TECHNICAL FIELD The present invention relates to a cold-setting fluororesin aqueous coating composition excellent in water resistance, water resistance, and solvent resistance, and an article coated with the cold-setting fluororesin aqueous coating composition.

[0002]

2. Description of the Related Art The purpose of coating a surface of a so-called alkaline inorganic cured product such as metal or cement, or a surface of a plastic or the like is mainly to improve so-called durability such as weather resistance, chemical resistance or water resistance of a substrate. For the sake of brevity, of course, consideration is given to the total form, including protection and beauty.

[0003] In recent years, as a coating agent for building exterior materials and industrial materials that are exposed to the outdoors,
There is a growing demand for long-lasting, maintenance-free products that are excellent in durability.

Under these circumstances, fluoroolefin-based copolymers (so-called fluororesins) are known as binders providing high weather resistance and high chemical resistance, and are mainly commercially available in the form of an organic solvent solution. I have.

[0005] However, an aqueous binder is required because it contains a large amount of an organic solvent and has problems such as fire danger, harm and air pollution.

Various aqueous dispersions of fluoroolefin-based polymers obtained using tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, etc. have been proposed. Baking at a high temperature is necessary. For example, in the invention described in JP-A-57-38845, a copolymer of vinylidene fluoride and hexafluoropropylene has an intrinsic viscosity of [Η] is 0.1 to
Despite the low molecular weight of 0.5,
Baking at a temperature of 230 ° C. is forced.

Of course, such high-temperature baking is not possible in the field of on-site painting and dry-dry paints, and is economically disadvantageous even in factory line painting which basically requires heat drying.

On the other hand, JP-A-61-26167 proposes a coating composition based on an emulsion polymer comprising a fluoroolefin, an alkyl vinyl ether and a vinyl carboxylate as a method for solving such a problem. Although the film forming properties at low temperatures are greatly improved, it is difficult to obtain a film having a sufficient film forming degree at room temperature, and the solvent resistance is also insufficient.

On the other hand, JP-A-2-214756 proposes an aqueous coating composition containing a fluororesin aqueous dispersion having a carbonyl group in the molecule and a hydrazine compound. However, although cross-linking between particles occurs, the copolymerizability of the carbonyl group-containing monomer is poor, which leads to a decrease in the degree of polymerization and the degree of polymerization, and eventually, the properties of the coating film are reduced. Therefore, it cannot be said that it is still sufficient.

[0010]

Accordingly, water-based coatings having a tough interparticle bond even at room temperature and sufficiently satisfying the durability of the coating film such as water resistance and solvent resistance can be obtained. The fact is that the agent does not currently exist.

[0011] However, the present inventors formed crosslinks between emulsion particles under the condition of drying at room temperature to obtain a room temperature-curable fluorine having excellent water resistance, especially boiling water resistance and solvent resistance. Intensive research has been started in search of a novel technique of providing a water-based resin coating composition and a coated article.

Therefore, an object of the present invention and a problem to be solved by the present invention are, in part, weather resistance and
Excellent durability in the total sense, that is, water resistance including boiling water resistance, and excellent in solvent resistance and chemical resistance, etc., a very practical room temperature-curable fluororesin aqueous coating composition, And to provide an article coated with the composition.

[0013]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the existence of the advantages and disadvantages of the prior art, and aiming at the problems to be solved by the present invention described above,
As a result of intensive studies, the disadvantages of the conventional fluoroolefin-based aqueous resin dispersion in terms of film-forming properties were identified as an aqueous resin dispersion in which a specific monomer mixture was emulsion-polymerized and a specific curing agent. Aqueous coating composition consisting of, the target, even under dry conditions at room temperature, causing cross-linking between particles, and can form a strong film-forming state, in addition, such as water resistance and solvent resistance However, the inventors have found that the durability of the coating film can be improved, and the present invention has now been completed.

[Structure] That is, the present invention basically comprises a fluoroolefin, a specific formyl group-containing ethylenic monomer such as crotonaldehyde and / or alkenal, and another copolymerizable monomer. Room temperature curable fluorine comprising an aqueous resin dispersion obtained by emulsion polymerization of a compound and hydrazine and / or a compound having at least two hydrazide groups in one molecule as essential film-forming components. An object of the present invention is to provide a resin aqueous coating composition, and also to provide an article coated with the cold-curable fluororesin aqueous coating composition.

As described above, the present invention firstly provides an aqueous resin dispersion obtained by emulsion-polymerizing a mixture of specific monomer components, and at least two aqueous resin dispersions per molecule represented by dihydrazide of dicarboxylic acid. By mixing with a compound having a hydrazide group and / or hydrazine,
This is to prepare a cold-curable aqueous fluororesin dispersion.

The above-mentioned fluoroolefins mentioned here are only typical ones.
Vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, 1,1,3,3,3
-Including fluoroolefins in a pure sense, such as pentafluoropropylene, 2,2,3,3-tetrafluoropropylene, 1,1,2-trifluoropropylene or 3,3,3-trifluoropropylene;

Further, chlorotrifluoroethylene,
In a broad sense, it includes compounds having a halogen atom other than a fluorine atom, such as bromotrifluoroethylene, 1-chloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene. And the like.

In particular, vinylidene fluoride, hexafluoropropylene, 1,1,3,3,3-pentafluoropropylene, 2,2,3,3-tetrafluoropropylene,
1,1,2-trifluoropropylene, 3,3,3-trifluoropropylene, chlorotrifluoroethylene,
Fluoroolefins such as bromotrifluoroethylene, 1-chloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene are more preferably hexafluoropropylene, chlorotrifluoroethylene or fluorinated olefins. Vinylidene and the like are also suitable from the viewpoint of controlling the reaction at the time of polymerization.

The proportion of fluorine atoms in the fluoroolefin-based copolymer, that is, the fluorine content in the copolymer, itself has an influence on the coating film obtained, especially on the weather resistance and the like. In view of the large size, the fluorine content is desirably approximately 4% by weight or more.

From such a viewpoint, it is appropriate that the amount of the fluoroolefin used is in the range of 10 to 80% by weight based on all the monomers.

On the other hand, among the other monomers which can be copolymerized with the fluoroolefins, various ones can be considered as the main ones. It should be selected in consideration of various film performances such as chemical resistance, water resistance, alkali resistance, heat resistance and flexibility, and is particularly representative of such major copolymerizable monomers. The following is only an example.

(1) Various unsaturated carboxylic acids and their esters such as crotonic acid, itaconic acid, citraconic anhydride or itaconic anhydride; and (2) Various unsaturated groups such as citraconic acid or itaconic acid. Various unsaturated group-containing polyhydroxyalkyl esters such as di-hydroxyalkyl esters of polycarboxylic acids, (3) methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether; Isoamyl vinyl ether, n-hexyl vinyl ether, n-
Various alkyl or aralkyl vinyl ethers such as octyl vinyl ether, 2-ethylhexyl-vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, methylcyclohexyl vinyl ether, benzyl vinyl ether or phenethyl vinyl ether;

Various (per) fluoroalkyl vinyl ethers such as perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether or perfluorocyclohexyl vinyl ether, and various types such as 4-hydroxybutyl vinyl ether (4) vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl neononanoate, and the like.
Vinyl neodecanoate, vinyl laurate, vinyl stearate, vinyl 2-ethylhexanoate, vinyl pt-butylbenzoate, vinyl salicylate, vinyl monochloroacetate or vinyl cyclohexanecarboxylate,
Various carboxylic acid vinyl esters,

(5) Various (halogenated) olefins such as vinyl chloride, vinylidene chloride, ethylene, propylene, 1-butene and isobutene; or (6) butadiene, hexadiene, octadiene, decadiene,
Various crosslinkable monomers having two or more polymerizable unsaturated groups in the molecule, such as tetradecadiene, 2-methyloctadiene, decatriene or diallyl phthalate, vinyltrimethoxysilane, vinyltriethoxysilane Alternatively, there are various kinds of crosslinkable monomers other than the above, such as various hydrolyzable silyl group-containing monomers such as vinyl tris (2-methoxyethoxy) silane.

As described above, among the various copolymerizable monomers, vinyl ethers and / or vinyl esters are preferably used in an amount of 5 to 90% by weight, and olefins are preferably used. Is suitably used within the range of 3 to 20% by weight.

Of these various copolymerizable monomers, vinyl ethers, when used in an aqueous medium, are easily hydrolyzed under certain conditions, so that vinyl ethers are used. It is more desirable to use other copolymerizable monomers except for L-type monomers.

Other examples of the copolymerizable monomers include a fluoroalkyl group-containing ethylenic monomer. In this case, the copolymerizability with the fluoroolefin and the final Should be selected in consideration of, for example, the durability of the coating film of the aqueous coating composition obtained.

The above-mentioned crotonaldehyde and / or formyl group-containing monomers are specific.
Alternatively, among alkenals, examples of only typical alkenals include 6-heptenal and 10-undecenal.

Monomers containing a carbonyl group or a formyl group, such as acrylic acid derivatives such as acrolein, diacetone acrylamide or formyl styrene, and styrene derivatives, can be used together with fluoroolefins and vinyl carboxylate. The use of these compounds should be discouraged because of their poor polymerizability, and their use is therefore discouraged.

The formyl group-containing monomer is used in an amount of 0.01 to 20% by weight, preferably 0.5 to 10% by weight, and more preferably 0.5 to 10% by weight, based on all monomers.
A range of 7% by weight is appropriate.

If the amount is less than 0.01% by weight, the effect of the use of the monomer is hardly exhibited,
On the other hand, when used in an excessively large amount exceeding 20% by weight, not only the effect is saturated, but also the flexibility of the obtained coating film is liable to be reduced in any case.

[0032] Crosslinkable monomers are desirable in terms of enhancing the durability of the resulting coating film. During the emulsion polymerization, such crosslinkable monomers are used in an amount of from 0.1 to 0.1% of the monomer mixture. It is also possible to use within a range of 2% by weight. 0.1% by weight
If the amount is less than the above, the crosslinking effect is not sufficient. On the other hand, if the amount is more than 2% by weight, the effect is not only saturated but also the film-forming property tends to be impaired. Therefore, either case is not preferable.

The above-mentioned crosslinkable monomers are used for crosslinking inside emulsion particles.
It is for improving the durability of the particles through such crosslinking.

In such a sense, the so-called “interparticle cross-linking” effected via formyl groups, which is achieved by using the cold-curable fluororesin aqueous coating composition of the present invention as a coating, is as described above. It can be said that "intraparticle crosslinking" by so-called crosslinking monomers is completely different.

The solid portion of the aqueous resin dispersion used in the present invention (hereinafter also referred to as an aqueous dispersion) is not particularly limited, but the solid portion is in the range of 20 to 60% by weight. It is practically preferable to be within the range.

The Tg of the copolymer constituting the aqueous resin dispersion of the present invention is not particularly limited, but is in the range of -20 ° C. to + 60 ° C. in consideration of the film forming property of the obtained coating film. Is desirable.

In order to prepare the aqueous resin dispersion,
A required amount of a monomer selected from the various monomer groups described above may be carried out by an emulsion polymerization method as described below in the presence of an emulsifier, a polymerization initiator and water.

The above-mentioned emulsifiers used in this case are particularly typical examples of various emulsifiers such as anionic emulsifiers, nonionic emulsifiers or cationic emulsifiers, and other reactive emulsifiers or fluorine-based surfactants. Emulsifiers, and various substances having surface activity such as acrylic oligomers. Among them, nonionic and / or anionic emulsifiers are used to form aggregates during polymerization. This is particularly desirable because of the low production of, and a stable emulsion obtained.

As the above-mentioned nonionic emulsifiers, only typical ones are exemplified, and polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ether, polyoxyethylene higher fatty acid ester, ethylene oxide-propylene oxide block copolymer may be used. Polymers and the like, and if only particularly representative examples of the above-mentioned anionic emulsifier are given, alkali metal salts of alkyl (benzene) sulfonic acid,
Alkyl sulfate alkali metal salts, polyoxyethylene alkyl phenol sulfate alkali metal salts and the like.

Further, instead of the above-mentioned anionic emulsifiers, or in combination, various water-soluble oligomers composed of polycarboxylic acids or sulfonates can be used.

Further, various water-soluble polymer substances such as polyvinyl alcohol and hydroxyethyl cellulose can be used as protective colloids. The amount of the emulsifiers and the like listed above is about 0.1 to 10% by weight based on the total amount of the monomers.

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

The amount of the polymerization initiator used is suitably in the range of 0.1 to 2% by weight based on the total amount of the monomers. Needless to say, a method well-known as a so-called redox polymerization method using a combination of these polymerization initiators, a metal ion and a reducing agent may be used.

In the present invention, the monomers may be used individually, as they are, or in an emulsified state, collectively or in the presence of water, preferably ion-exchanged water and, if necessary, in the presence of an emulsifier. Dropwise or continuously, the solution is dropped into the reaction vessel, and 0 to 1 in the presence of the polymerization initiator described above.
At a temperature of 00 ° C, preferably 30-90 ° C,
１００100 kg / cm ² , preferably 6-50 kg / c
The polymerization may be performed at a pressure of m ² .

The ratio of total monomer to water should be set so that the final solids content is in the range of 20-60% by weight. In performing emulsion polymerization, a seed polymerization method may be used in which emulsion particles are previously present in an aqueous phase and polymerized in order to grow or control the particle diameter.

The particle size of the aqueous resin dispersion obtained in this manner is suitably in the range of about 0.05 to 3 microns (μm). The compound containing at least two hydrazine and hydrazyl groups in one molecule causes a cross-linking reaction with formyl groups contained in the aqueous resin dispersion as the coating film dries, thereby strengthening the film formation, and the mechanical properties in the early stage of coating film formation. The purpose is to improve physical properties of the coating film such as mechanical strength and water resistance.

Therefore, such hydrazine and / or
Alternatively, as a compound having two or more hydrazyl groups (—NHNH ₂ ) in one molecule (hereinafter, also referred to as a hydrazyl group-containing compound), only typical compounds are exemplified, and oxalic acid dihydrazide, malonic acid Dihydrazide, succinic dihydrazide, glutaric dihydrazide,
Various dihydrazides of dicarboxylic acids, such as adipic dihydrazide and sebacic dihydrazide; di- or trihydrazides of tricarboxylic acid; various dihydrazides of disulfonic acid, such as bis (hydrazinesulfonyl) benzene; disulfonic acid of trisulfonic acid; -Or trihydrazides;

Various dihydrazine adducts of diepoxy compounds such as dihydrazine adducts of diglycidyl ether; di- or trihydrazine adducts of trialepoxy compounds; carbonic dihydrazides of C _{2 to} C ₅ ; bis Semicarbazides; ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-
Compounds such as 1,4-dihydrazine, and furthermore, polyhydrazides of polycarboxylic acid; polyhydrazides of polysulfonic acid, and the like.

[0049] The amount of the hydrazyl group-containing compound used is such that the amino group derived from the hydrazyl group is used in an amount of 0.00 mol per mol of the formyl group contained in the aqueous resin dispersion.
An amount corresponding to 1 to 5 moles is suitable, and more preferably an amount corresponding to 0.1 to 2 moles. 0.01
If the amount is less than 5 mol, the effect of crosslinking is insufficient, while if the amount exceeds 5 mol, the effect is not only saturated, but rather, the strength of the coating film is reduced.
Either case is not preferred.

Further, as a more preferred type of the hydrazyl group-containing compound, a compound having a certain degree of water solubility is suitable. Examples of such a compound are hydrazine, malonic dihydrazide, glutar Acid dihydrazide, carbonic acid dihydrazide, bissemicarbazide, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine or butylene-1,4-dihydrazine, etc., and more preferably hydrazine, carbonic acid dihydrazide, bissemicarbazide , Ethylene-1,2-dihydrazine or propylene-1,3-dihydrazine.

Next, the above-mentioned pigments, which are one of the further main components of the aqueous coating composition, will be described. Such pigments, the hardness of the coating film, opacity, improvement of aesthetic appearance by coloring, adhesion to the substrate,
It is appropriately selected and used for the purpose of improving chemical resistance or weather resistance, for example. The amount used is 200 to the solid content of the aqueous resin dispersion described above.
It is desirable that the content is not more than% by weight. If the amount is more than 200% by weight, the resulting coating film tends to be porous, and the long-term durability such as water resistance is unfavorably deteriorated.

As typical examples of the pigments to be used, only typical ones are exemplified. Titanium oxide, mica, talc, clay, precipitated barium sulfate, silica powder,
Inorganic pigments such as calcium carbonate, iron oxide, zinc oxide, aluminum powder, and carbon; or organic pigments such as phthalocyanine blue; or these various pigments are mixed with an emulsifier and / or dispersant. Thus, it is possible to use so-called dispersed pigments in a form dispersed in water, and they are appropriately selected and used according to the respective purposes.

As various additives required for coating, for example, dispersants, wetting agents, film-forming auxiliaries,
Use of thickeners, thixotropic agents, ultraviolet absorbers, antioxidants, water repellents, antifreezes, antiseptic or antifungal agents or defoamers, etc. may result in the resulting coating Should be appropriately selected and used in consideration of the various performances.

The coating method is as follows. First, as a base material, various types of alkaline inorganic cured products such as a concrete frame, a wall material or a roof material, or a general architectural material such as a metal plate. If it is a substrate, it is not particularly limited, and then, as a coating means, known and commonly used means such as brush coating, roller coating, spray coating, roll coater coating or showering coating can be adopted, The base material and means, depending on the situation,
Just choose.

At this time, as a composition for construction at a construction site or the like, that is, a so-called room temperature drying type, the minimum film-forming temperature of the room temperature curing type fluororesin aqueous coating composition is set to 0 ° C. or lower. It is desirable to use a brush, a roller, a spray, or the like as a coating method. Drying conditions are 0 ° C. or higher, preferably 20 ° C.
Drying at 7 ° C. or higher for 7 days results in a completely cured coating film.

On the other hand, it can also be used for so-called factory line painting of roof materials such as tiles and wall materials, and is generally used in accordance with the drying conditions according to the heating and forced drying method. It is desirable to select and use a paint prepared so that the minimum film-forming temperature of the aqueous paint composition is generally 60 ° C. or lower, preferably 50 ° C. or lower. As a coating method, a roll coater or a roller is used. , Spraying or showering.

The aqueous coating composition may be applied directly on the substrate in one coat or in multiple coats, or may be applied in the form of an acrylic or acrylic-styrene copolymer. , Acrylic-urethane combined system, silicon-
In general, a primer or base coat (undercoat) using a coating material containing a binder having good alkali resistance, such as an acrylic combination type, an epoxy type, a urethane type or a silicon type, as a primer, Alternatively, the aqueous coating composition may be applied to improve and improve the weather resistance and the like of the entire coating system.

Regardless of the type of each coating system, a dry thick film of the aqueous coating composition of 5 μm or more is appropriate. If less than 5 μm,
This is because the long-term durability of the film tends to be insufficient.

Thus, according to the method of the present invention, the room-temperature-curable fluororesin aqueous paint excellent in various film properties such as super weather resistance, water resistance and boiling water resistance, etc., and extremely high in practical use. An article coated with the composition is obtained.

[0060]

Next, the present invention will be described more specifically with reference examples, examples and comparative examples. In the following, all parts are by weight unless otherwise specified.

REFERENCE EXAMPLE 1 In a stainless steel autoclave of 2 liters, 720 parts of ion-exchanged water, 16 parts of sodium dodecylbenzenesulfonate, 8 parts of polyoxyethylene nonylphenol ether (HLB = 17), and ammonium hydrogen carbonate Were dissolved in the mixture, and the inside of the autoclave was degassed with nitrogen.

Then, 8 parts of crotonic acid, "Veoba
9 "(vinyl ester of a branched saturated aliphatic carboxylic acid manufactured by Shell Co., Netherlands), 424 parts of crotonaldehyde, and 320 parts of liquefied and collected vinylidene fluoride were put into a pressure-resistant drip tank. Further, ethylene was injected into the autoclave to a pressure of 15 atm.

Thereafter, the autoclave was heated to 80 ° C., and while stirring, 5.6 parts of ammonium persulfate dissolved in 80 parts of ion-exchanged water were mixed with the monomer placed in the pressure-resistant dropping tank. , Dripped over 3 hours and brought to the same temperature,
The reaction was maintained for a further 3 hours to complete the reaction.

The product thus obtained has a nonvolatile content of 5
The emulsion polymer was 0% and had a pH of 1.6.
After cooling to room temperature, the pH of the reaction mixture was adjusted to 7.5 with 14% aqueous ammonia, and finally, the non-volatile content was adjusted to 45% with ion-exchanged water. An aqueous resin dispersion I having a softening point of 70 ° C. and a particle size of 0.08 μm was obtained.

Reference Examples 2 to 10 In the same manner as in Reference Example 1, except that the types and amounts of various monomers and various emulsifiers as shown in Table 1 were changed. Respectively, to obtain aqueous resin dispersions II, III, IV, V and VI (the above-mentioned aqueous resin dispersions for the present invention) and VII, VIII, IX, X and XI (the above-mentioned aqueous resin dispersions for the control). . The characteristic values of these various aqueous resin dispersions are shown in the same table.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

[0070]

[Table 5]

[0071]

[Table 6]

[0072]

[Table 7]

[0073]

[Table 8]

[0074]

[Table 9]

Examples 1 to 6 and Comparative Examples 1 to 4 Each of the aqueous resin dispersions obtained in Reference Examples 1 to 10 was blended according to the following paint formulations A and B, and each was at room temperature. A white or black glossy paint for drying was prepared.

The mixing ratio of the aqueous resin dispersion and the hydrazine compound, which are components for preparing the white or black glossy paint for normal temperature drying, and the aqueous resin dispersion 1
Table 2 shows the number of parts of the formyl group-containing monomer contained in 00 parts.

[Painting Formula A] (White glossy paint for normal temperature drying) Water 7.84 parts 25% ammonia water 0.15 parts "Neugen EA-120" 0.33 parts [Daiichi Kogyo Seiyaku Co., Ltd.] Wetting agent] "Tamol 731" (25% aqueous solution) 1.34 parts (dispersing agent manufactured by Rohm and Haas Co., USA) 7.46 parts ethylene glycol "Taipek R-930" 41.00 parts [Ishihara Sangyo ( Titanium dioxide manufactured by Co., Ltd.] "Best Side FX" 0.22 parts [Preservative manufactured by Dainippon Ink and Chemicals, Inc.] "Nopco 8034" 0.30 parts [Defoaming agent manufactured by San Nopco Co., Ltd.] ]

Next, 7.46 parts of “Serosize QP-4400” (3% aqueous solution) and an aqueous resin dispersion (thickener manufactured by UCC, USA) were added to the above components dispersed in a sand grinder. (Solid content = 45%) 100.00 parts, and butyl carbitol acetate (film-forming aid)
Was added in such an amount that the MFT (minimum film forming temperature) became 0 ° C., diluted with water so that the nonvolatile matter of the paint became 51%, and uniformly stirred with a stirrer.

[Painting Formula B] (Black glossy coating for drying at room temperature) Aqueous resin dispersion (solid content = 45%) 100.00 parts "Disperse Color SD-9020" 0.50 parts [Dainippon Ink Carbon dispersion pigment manufactured by Chemical Industry Co., Ltd.] 0.01 parts "Nopco 8034L" [Defoaming agent manufactured by San Nopco Co., Ltd.] 0.20 parts "Bestside FX" 0.33 parts "Neugen EA-120" Then, the mixture was uniformly stirred with a stirrer, and butyl carbitol acetate (a film-forming auxiliary) was added thereto in such an amount that the MFT became 0 ° C., and diluted with water so that the nonvolatile matter of the paint became 40%. The mixture was uniformly stirred with a stirrer.

[0080]

[Table 10]

[0081]

[0082]

[Table 11]

[0083]

[Table 12]

[0084]

[Table 13]

Examples 7 to 12 and Comparative Examples 5 to 8 The white or black glossy paint for drying at room temperature obtained in Examples 1 to 6 and Comparative Examples 1 to 4 was applied to various substrates, respectively. At least, various coated articles were obtained.

Each coated article was subjected to an evaluation test for various properties of the coating film. The results are shown separately in Table 3 (white glossy paint) and Table 4 (black glossy paint).

[Substrate] Substrate a ... Slate plate Substrate b ... Polished soft steel plate

[Coating method] Each of the base materials a and b was separately coated with various water-based paint compositions (water-based paints) at room temperature in an amount of 120 g / m ² ,
After drying at room temperature for 1 day, it was further coated with an amount of 80 g / m ^{2 and} dried at room temperature for 7 days to obtain various coated articles.

Next, each coated article was subjected to various tests as described below.

[Procedure of coating film test] Boiling water resistance: A change in the coating surface after immersion in boiling water for 2 hours is visually judged.... No change Δ: Somewhat poor. … Bleaching, blistering, etc., completely defective

Solvent resistance: Change in the coated surface after rubbing the coated surface 20 times (20 reciprocations) at 3 Kg / cm ² using absorbent cotton impregnated with toluene. The state is visually determined. ……… No change △ …… Slightly dissolved × ……… Completely dissolved

Accelerated weathering resistance: Gloss retention before and after the accelerated test for 3,000 hours was measured with a sunshine weather meter ○: 90% or more △: 70% to less than 90% ×: ... Less than 70%

[0093]

[Table 14]

[0094]

[Table 15]

[0095]

[Table 16]

[0096]

[Table 17]

[0097]

[Table 18]

[0098]

[Table 19]

[0099]

[Table 20]

[0100]

[Table 21]

[0101]

As described above, the cold-curable aqueous fluororesin coating composition of the present invention has not only excellent weather resistance but also excellent boiling water resistance and water resistance due to a strong film-forming state due to interparticle crosslinking. It is intended to provide an extremely practical water-based coating material capable of maintaining solvent resistance and the like for a long period of time, and an object to be coated.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 127/12

Claims (8)

(57) [Claims] 1. An aqueous resin dispersion obtained by copolymerizing a fluoroolefin, crotonaldehyde and / or alkenal, and other copolymerizable monomers, at least one hydrazine and / or one molecule in one molecule. A cold-setting fluororesin aqueous coating composition comprising a compound having two hydrazyl groups as an essential component and, if necessary, a pigment. 2. An aqueous resin dispersion obtained by copolymerizing a fluoroolefin, crotonaldehyde and / or alkenal, a crosslinkable monomer, and other copolymerizable monomers, and hydrazine. And / or a compound having at least two hydrazyl groups in one molecule as an essential component, and if necessary, a pigment. object. 3. The method according to claim 1, wherein the fluoroolefin is
Against solids of water-soluble resin dispersion, 10 to 80 wt%
3. The copolymer according to claim 1, which is copolymerized within a certain range.
A cold-setting fluororesin aqueous coating composition according to item 1. 4. A fluoroolefin mentioned above is, chlorotrifluoroethylene, selected from the group consisting of vinylidene fluoride and hexafluoropropylene, are those of at least one, normally according to claim 1, 2 or 3
A thermosetting fluororesin aqueous coating composition. Wherein said the crotonaldehyde and / or alkenal is, relative to solids of the aqueous resin dispersion is polymerized co Te than within range of 0.01 to 20 wt%, The normal temperature according to claim 1 , 2, 3, or 4.
Curable fluororesin aqueous coating composition. 6. formyl amino group derived from a hydrazyl group in a compound having at least two hydrazyl group in the above-mentioned hydrazine and / or one molecule, contained in the water-soluble resin dispersion described above Per mole of
The cold-setting fluororesin aqueous coating composition according to any one of claims 1 to 5 , which is contained in a proportion of 0.01 to 5 mol. 7. The crosslinkable monomers described above is, with respect to solid content of the water <br/> resin dispersions, are copolymerized in the range of 0.1 to 2 wt% The room temperature curing according to claim 2,
-Type fluororesin aqueous coating composition. 8. The normal according to any one of claims 1 to 7
An article coated with a thermosetting fluororesin aqueous coating composition.