JP3177844B2 - Aqueous paint composition - Google Patents

Description

The present invention relates to a novel and useful aqueous coating composition. More specifically, it comprises two specific aqueous resin dispersions as essential film-forming components. In particular, the coating film has excellent weather resistance, chemical resistance, stain resistance, and the like. The present invention relates to an extremely useful aqueous coating composition having good film properties.

And the water-based coating composition of the present invention is particularly useful mainly as a coating for architectural exterior.

[Conventional technology]

By the way, including metal materials and various metal products, the purpose of coating the surface of an alkaline inorganic cured material such as cement, or various plastics, mainly, weather resistance, chemical resistance and water resistance, etc. This is for the purpose of improving the so-called durability, and, of course, consideration is given to another aspect of beauty and protection.

In recent years, in particular, building exterior materials and industrial materials, so to speak,
A coating agent which is exposed to the outdoors, and which has excellent durability and is maintenance-free for a long period of time, has been required.

In order to meet such demands, fluoroolefin copolymers are prepared, and it is well known that this can be a binder component that can provide high weather resistance and high chemical resistance, It is commercially available in the form of a solution of an organic solvent.

However, because it contains a large amount of organic solvents,
Due to problems such as fire danger, harm, and air pollution, a water-based binder was required.

Although aqueous dispersions of polymers using fluoroolefins such as vinylidene fluoride, tetrafluoroethylene, or hexafluoropropylene have been proposed, these aqueous dispersions can be used at elevated temperatures during film formation. Baking is indispensable.
In the case of a copolymer of vinylidene fluoride and hexafluoropropylene, as disclosed in Japanese Patent No. 38845, although the intrinsic viscosity [η] is 0.1 to 0.5, which is a so-called low molecular weight, still, It is necessary to bake at a temperature of 180 to 230 ° C.

In that respect, baking at such a high temperature is just an impossible means in the field where the use of the ever-dry paint is always used, such as painting on site, and in principle, drying by heating is essential. This is economically disadvantageous in factory line painting.

On the other hand, Japanese Patent Application Laid-Open No. 61-261367 discloses an emulsified polymer obtained by using a fluoroolefin, an alkyl vinyl ether and / or a vinyl carboxylate in order to remove or eliminate a defect or a defect peculiar to the above-mentioned technology. A coalesce-based coating composition is disclosed, which has significantly improved film formability.

However, when an object to be coated obtained by using such a coating composition as a coating agent is exposed to the outside, not only the durability but also the appearance of the coating film deteriorates due to contamination of the coating film through dust and the like. Although it is not such that it is a very important point, weather resistance, durability of the coating film such as chemical resistance and water resistance, and that it can sufficiently satisfy the stain resistance, It can be said that an extremely useful aqueous coating agent has not been found so far.

[Problems to be solved by the invention]

For this purpose, the present inventors have enthusiastically started a study in search of an extremely useful aqueous coating composition which is excellent in various coating properties mainly on durability and stain resistance.

Therefore, the problem to be solved by the present invention is, on the one hand, excellent in film-forming properties at low temperatures, and also excellent in chemical resistance and stain resistance as well as weather resistance of the coating film. It is an object of the present invention to provide a highly useful aqueous coating composition.

[Means for solving the problem]

Therefore, the present inventors have focused on the advantages and disadvantages of the conventional technology as described above, and at the same time, focused on the problem to be solved by the invention as described above, and as a result of earnest and repeated studies, as a result, By blending two types of aqueous dispersions with different monomers, excellent film-forming properties in low-temperature region,
The present invention has been completed by finding that an aqueous coating composition excellent in weather resistance, chemical resistance, stain resistance and the like of a coating film can be obtained.

That is, the present invention relates to an aqueous coating composition containing, as essential components, a fluoroolefin-based aqueous resin dispersion (A) and a fluoroalkyl group-containing aqueous resin dispersion (B). When the content of the aqueous resin dispersion (B) is such that the content of unsaturated carboxylic acid in all monomers is 0.2 to 4% by weight and / or the content of crosslinkable monomer in all monomers is 0.05 The purpose of the present invention is to provide an aqueous coating composition which has been copolymerized within a range of 2 to 2% by weight.

Here, first, the above-mentioned fluoroolefin-based aqueous resin dispersion (A) refers to various α, β-ethylenically unsaturated compounds (hereinafter, referred to as “fluoroolefin-based”).
Also called vinyl monomer. ) Wherein the content of unsaturated carboxylic acid in all monomers is
0.2 to 4% by weight, and / or refers to a copolymer obtained by copolymerizing a crosslinkable monomer in a range of a content of 0.05 to 2% by weight in all monomers. If only a typical example of the dispersion (A) is exemplified, the fluoroolefin and the copolymerizable vinyl monomer are used in an amount of 10 to 10% by weight based on the total of 100% by weight of the fluoroolefin and the copolymerizable vinyl monomer. 70% by weight, an emulsion copolymer containing the copolymerizable vinyl monomer in a content of 90 to 30% by weight, among which a fluoroolefin, vinyl ether and / or vinyl ester, If necessary, α-olefins may be used in an amount of 10 to 70% by weight, a content of vinyl ether and / or vinyl ester of 90 to 30% by weight, α-olefin The content of the emissions class is 0
Emulsion copolymers and the like contained within the range of 30% by weight.

If only typical representative examples of fluoroolefins are given, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, 1,1,3,3,3-pentafluoropropylene, 2,2 , 3,3-
Including so-called pure forms of fluoroolefins, such as tetrafluoropropylene, 1,1,2-trifluoropropylene or 3,3,3-trifluoropropylene, furthermore, chlorotrifluoroethylene, bromotrifluoroethylene, A range that can be said to be a fluorine-containing vinyl compound including compounds having other halogen atoms other than fluorine, such as 1-chloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene. And fluoroolefins in a broad sense.

These fluoroolefins impart significantly improved weather resistance, chemical resistance, and the like to the obtained coating film from the aqueous dispersion (A).

Therefore, the amount of the fluoroolefin used in all the monomers constituting the dispersion (A), that is, within the range of 10 to 70% by weight based on the total amount of all the monomers,
Preferably, a range of 30 to 70% by weight is appropriate.

Then, other vinyl monomers that can be copolymerized with such a fluoroolefin are, in particular, weather resistance, chemical resistance and water resistance of the obtained copolymer, and in consideration of film forming properties, From various known and commonly used monomers,
Of these, vinyl ethers and / or vinyl esters and α-olefins can be selected, and only representative ones among them are exemplified.

Among them, first, only typical examples of vinyl ethers are exemplified, and methyl-, ethyl-, n-propyl-, isopropyl-, and n-
Butyl, isobutyl-, tert-butyl, isoamyl-,
Various alkyl vinyl ethers such as n-hexyl-, n-octyl- or 2-ethylhexyl-vinyl ether; various cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl vinyl ether; aralkyl vinyl ethers such as benzyl vinyl ether or phenethyl vinyl ether Class; 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 It has a substituted or unsubstituted alkyl group such as various (per) fluoroalkyl vinyl ethers such as vinyl ether or perfluorocyclohexyl vinyl ether; or various hydroxyalkyl vinyl ethers such as 2-hydroxyethyl vinyl ether or 4-hydroxybutyl vinyl ether. Things.

Further, if only particularly typical examples of the above-mentioned vinyl esters are exemplified, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, "vinyl versatate" (Ciel, Netherlands), vinyl laurate,
Vinyl stearate, vinyl benzoate, p-tert-vinyl benzoate, vinyl salicylate, vinyl monochloroacetate or vinyl cyclohexanecarboxylate, and the like, and only the particularly typical α-olefins described above. If it stops, it is ethylene, propylene or butene-1 or the like.

Among these various copolymerizable vinyl monomers described above, vinyl ethers and / or vinyl esters and α-olefins include fluoroolefins, vinyl ethers and / or vinyl esters, and α-olefins. 30 to 9 respectively, for a total of 100% by weight of
0% by weight and 0 to 30% by weight, preferably 30% by weight.
Suitably, it is within the range of ~ 60% by weight and 5-20% by weight.

On the other hand, the above-mentioned fluoroalkyl group-containing aqueous resin dispersion (B) refers to an emulsion copolymer of various vinyl monomers mainly composed of a fluoroalkyl group-containing vinyl monomer. If only a typical example of the resin dispersion (B) is exemplified, a fluoroalkyl group-containing vinyl monomer and a copolymerizable vinyl monomer may be used.
The content of the fluoroalkyl group-containing vinyl monomer is within the range of 5 to 80% by weight and the content of the copolymerizable vinyl monomer is within the range of 95 to 20% by weight based on the total of 100% by weight. Emulsion copolymers and the like.

As typical examples of the fluoroalkyl group-containing vinyl monomer, only typical ones are exemplified, and fluoroalkyl group-containing vinyl ethers, fluoroalkyl group-containing vinyl esters, or fluoroalkyl group-containing (meth) acrylates And so on.

Among them, first, if only typical examples of fluoroalkyl group-containing vinyl ethers are given, trifluoromethyl vinyl ether, 1,1,1
-Including trifluoroethyl vinyl ether, 2,2-difluoroethyl vinyl ether or tetrafluoroethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, perfluorohexyl vinyl ether, perfluorooctyl vinyl ether or perfluorododecyl Like vinyl ether,
Various vinyl ethers having a (per) fluoroalkyl group having 2 to 12 carbon atoms; or vinyl ethers having a fluoroalkyl group in which some hydrogen atoms of an alkyl group having 2 to 12 carbon atoms are substituted with fluorine And the above-mentioned fluoroalkyl group-containing (meth)
If only typical acrylates are exemplified, various (per) fluoroalkyl group-containing alcohols corresponding to various (per) fluoroalkyl group-containing vinyl ethers as described above and ( Esters with (meth) acrylic acid, etc.
Only typical representative examples of the above-mentioned fluoroalkyl group-containing vinyl esters include vinyl trifluoroacetate.

The aqueous resin dispersion (B) is mixed with the above-mentioned fluoroolefin-based aqueous resin dispersion (A) from the place where the fluoroalkyl group-containing vinyl monomer as the main monomer component is used. It has excellent compatibility,
In addition, the coating is excellent in water / oil repellency and stain resistance.

From this, it can be said that the dispersion (B) is a component that promises to improve the water resistance and stain resistance of the coating film in the aqueous coating composition of the present invention.

From such a viewpoint, it is necessary to select and select the types of the fluoroalkyl group-containing vinyl monomers as described above and the amount of the vinyl monomers to be used.
A suitable range is from about 80% by weight to about 80% by weight, preferably from 10 to 15% by weight.

Next, the vinyl monomer copolymerizable with the fluoroalkyl group-containing vinyl monomer should be selected in consideration of the durability of the coating film as the whole of the composition of the present invention. If only typical ones are exemplified, they are known and commonly used vinyl ethers, vinyl esters, (meth) acrylates or α-olefins, and furthermore, styrene and the like.

The aqueous resin dispersions (A) and (B), which constitute the composition of the present invention and are essential film-forming components, respectively, are each prepared by applying a known and commonly used emulsion polymerization method. It is to be prepared.

That is, it can be obtained by an emulsion polymerization method in which a radical polymerization initiator is used in the presence of various dispersants such as an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, or a protective colloid.

At that time, it is desirable to increase the molecular weight of each copolymer constituting each of the aqueous resin dispersions (A) and (B) in order to improve the durability of the resulting coating film to the general one. It is preferable to use the crosslinkable monomer in the range of 0.05 to 2% by weight based on the total amount of the monomers at the time of each emulsion polymerization for preparing the two dispersions.

If the amount is less than 0.05% by weight, the cross-linking effect cannot be sufficiently obtained. On the other hand, if the amount exceeds 2% by weight, not only the cross-linking effect becomes saturated, but also the film forming property is impaired. In either case, it is not preferable.

Only typical representative examples of such crosslinkable monomers include divinyl compounds and vinylsilanes.

Specifically, di (meth) acrylate compounds, tri (meth) acrylate compounds, diallyl compounds or triallyl compounds; or 1,7-octadiene or
Particularly representative compounds are terminal dienes such as 1,9-decadiene; and trialkoxysilanes having an alkoxysilyl group in the molecule. Of course, these may be used alone or in combination of two or more.

Separately, each of the aqueous resin dispersions (A) and (B) having an appropriate acid value improves the pigment dispersibility of the entire aqueous coating composition of the present invention. And these two dispersions (A)
And the compatibility between (B) and the general is improved,
Further, it is desirable from various aspects that the obtained paint also has an improved adhesion to the base material.

At that time, α, β-ethylenically unsaturated carboxylic acid (hereinafter referred to as “unsaturated carboxylic acid”) is completely used during the emulsion polymerization for obtaining each of the aqueous resin dispersions (A) and (B). 0.2 to 4% by weight in the monomer, preferably
It is preferable to use within a range of 0.5 to 3% by weight.

When the amount is less than 0.2% by weight, the effect tends to be insufficient. On the other hand, when the amount exceeds 4% by weight,
Either case is not preferable because the resulting coating film may reduce chemical resistance such as water resistance and alkali resistance.

If only typical examples of such unsaturated carboxylic acids are exemplified, unsaturated monobasic acids (unsaturated monocarboxylic acids) such as (meth) acrylic acid or crotonic acid, or salts thereof; or Unsaturated dibasic acids such as itaconic acid, maleic acid or fumaric acid, or their half esters or various salts.
Of course, these may be used alone or in combination of two or more.

Each aqueous resin dispersion (A) thus obtained
And (B) exhibit the respective functions as described above, and (A) :( B) = 20: 80 to 9 in terms of solids weight%.
It is preferable to mix and use them in the range of 5: 5, and it is preferable to mix them in the range of (A) :( B) = 40: 60 to 90:10.

The solid content of each of the aqueous resin dispersions (A) and (B) is not particularly limited, but practically preferably in the range of 20 to 60% by weight.
desirable.

Further, the glass transition temperature (Tg) of each of the copolymers constituting each of these aqueous resin dispersions is not particularly limited, but the stain resistance of the coating film obtained from the obtained composition of the present invention is not limited. In view of the balance with the film forming property of the composition of the present invention, it is desirable that the temperature is in the range of −5 ° C. to + 60 ° C.

Next, a pigment can be listed as a component of the aqueous coating composition of the present invention.

Such pigments are suitably used for the purpose of improving the hardness of the coating film, concealing property, improving the appearance by coloring, and improving the coating properties such as adhesion to the substrate to be coated, chemical resistance and weather resistance. The amount of the pigment to be used is suitably within the range of 200% by weight or less based on the total solid content of the aqueous resin dispersions (A) and (B) described above. is there.

When used in a large amount exceeding 200% by weight, the obtained coating film is inevitably porous, which is unfavorable because long-term durability such as water resistance is impaired.

If only typical pigments are exemplified, inorganic pigments such as titanium oxide, mica, talc, precipitated barium sulfate, silica powder, calcium carbonate, iron oxide, zinc oxide, aluminum powder or carbon black Organic pigments such as phthalocyanine blue, phthalocyanine green or quinacridone red; or so-called dispersed pigments in which these various pigments are dispersed in water with an emulsifier or dispersant.

In addition to these pigments, the aqueous coating composition of the present invention may further include various additives necessary for coating, such as a dispersant, a wetting agent, a film-forming auxiliary, a thickening agent, and a thixotroping agent. Agent, UV absorber, antioxidant, water repellent, antifreeze,
An antiseptic / antiseptic or an antifoaming agent is appropriately selected and used in consideration of the performance of the obtained coating film and within a range not departing from the purpose and effect of the present invention.

The water-based coating composition of the present invention is used not only in all fields which can be mainly used as a water-based coating, but is particularly useful for architectural exterior coatings and the like.

〔Example〕

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

Reference Example 1 [Preparation Example of Aqueous Resin Dispersion (A)] In a stainless steel autoclave of 2, 15 parts of “Neogen R” [sodium dodecylbenzenesulfonate manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .; active ingredient content = 60%], 6 parts of “Neugen EA130T” (polyoxyethylene nonyl phenol ether manufactured by the same company; HLB = 13, active ingredient content = 10
0%], 6 parts of Neugen EA-170 (same as above; HLB = 17, active ingredient content = 100%), 3 parts of ammonium bicarbonate and 650 parts of ion-exchanged water, and stir-mix. Degassed.

Separately, 9 parts of methacrylic acid and 180 parts of ethyl vinyl ether were combined with “Veoba 9” (vinyl ester of the above “Versatic acid” manufactured by Shell, Netherlands).
48 parts and 60 parts of vinyl acetate, 3 parts of 1,7-octadiene and 28 parts of liquefied and collected hexafluoropropylene
0 parts was placed in a pressure-resistant drip tank, and ethylene was further injected into the autoclave at 30 atm.

The inside of the oak trave was heated to 65 ° C., and while stirring, 5 parts of ammonium persulfate dissolved in 90 parts of ion-exchanged water and the monomer mixture in the pressure dropping tank were each mixed for 6 hours. The reaction was completed by keeping the mixture at the same temperature for 2 hours.

After cooling to room temperature, the pH of the reaction mixture was adjusted to 7.5 with 14% aqueous ammonia to obtain the desired dispersion (A). Hereinafter, this is referred to as an aqueous resin dispersion (A-1). The characteristic values of this are shown in Table 1.

Reference Example 2 (same as above) A target dispersion (A) was obtained in the same manner as in Reference Example 1, except that the raw materials shown in Table 1 were used in a predetermined amount. Hereinafter, this is referred to as an aqueous resin dispersion (A-2). The characteristic values of this are shown in the same table.

Reference Examples 3 and 4 [Preparation Examples of Aqueous Resin Dispersion (B)] The raw materials as shown in Table 1 were changed to be used in a predetermined amount, and therefore, all monomers were charged at normal pressure. In the same manner as in Reference Example 1, except that the procedure was changed as described in Example 1, a target dispersion (B) was obtained. Hereinafter, each dispersion (B) was referred to as aqueous resin dispersions (B-1) and (B-1).
-2). In addition, each characteristic value is shown in the same table,
Shown together.

Reference Examples 5 and 6 (Examples of Preparation of Aqueous Resin Dispersion Free of Fluoroolefin and Fluoroalkyl Group-Containing Vinyl Monomer) The raw materials as shown in Table 1 were changed to be used in predetermined amounts, In the same manner as in Reference Example 1, except that all the monomers were charged at normal pressure, the aqueous resin dispersions (A'B'-1) and (A'B'-) for comparison were used. 2) was obtained. Each characteristic value is shown in the table,
Shown together.

Examples 1 to 4 and Comparative Examples 1 to 6 The various aqueous resin dispersions obtained in Reference Examples 1 to 6 were used at mixing ratios as shown in Table 2, and by the following formulation, An aqueous coating composition was prepared.

That is, first, according to the following paint formulation
Various glossy white paints for normal drying were prepared.

Water 7.84 parts 25% ammonia water 0.15〃 “Neugen EA-120” 0.33〃 (wetting agent manufactured by former company) “Tamol 731” 1.34〃 (dispersing agent manufactured by Rohm and Haas Company, USA)
25% aqueous solution ethylene glycol 7.46〃 “Taipec R-930” 41.00〃 [Titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.] “Best Side FX” 0.22〃 [Preservative manufactured by Dainippon Ink and Chemicals, Inc.] “Nopco 8034” 0.30〃 [Anti-foaming agent manufactured by San Nopco Co., Ltd.] Disperse the above components with a high-speed stirrer,
To here, 7.46 parts of "Cellosize QP-4400" (thickener manufactured by Union Carbide Co., USA) 3% aqueous solution "Chisso Sizer CS-12" 4.00〃 [Film-forming aid manufactured by Chisso Corporation] Butylcarb Toll acetate 3.40〃 Aqueous resin dispersion mixture 45.00〃 (in terms of solid content) was added, and the whole was uniformly mixed and dispersed with a stirrer.
A paint having a paint non-volatile content of 51% and a PWC of 47% was obtained.

Example 5 and Comparative Examples 7 to 10 The various aqueous resin dispersions obtained in Reference Examples 2, 4 and 6 were used at mixing ratios as shown in Table 3, and according to the following formulation: An aqueous coating composition was prepared.

That is, various black glossy paints for forced drying by heating were prepared according to the following paint formulation.

Water 11.5 parts Aqueous resin dispersion mixture 45.00〃 (in terms of solid content) Butyl carbitol acetate 1.50〃 “Disperse Color SD-9020” 1.00 parts [Carbon black dispersion pigment manufactured by Dainippon Ink and Chemicals, Inc.] Nopco 8034L ”(product of a previous company) 0.01〃“ Vesside FX ”0.20〃 Various components more than 0.20〃 are uniformly mixed and dispersed with a stirrer.
A paint having a paint non-volatile content of 40% and a PWC of 1% was obtained.

Example 6 and Comparative Examples 11 and 12 Various aqueous resin dispersions obtained in Reference Examples 2, 4 and 6 were used at mixing ratios as shown in Table 3, and according to the following formulation: An aqueous coating composition was prepared.

That is, first, according to the following paint formulation
Various kinds of white glossy paints for heat forced drying metal were prepared.

Water 3.00 parts Butyl cellosolve 6.00〃 25% aqueous solution of “Tamol 731” 0.50〃 “Watersol S-352” 3.00〃 65% aqueous solution of [water-soluble resin for dispersion manufactured by Dainippon Ink and Chemicals, Inc.] Dimethylethanolamine 0.05 parts “For Master VL” 0.10〃 [Antifoaming agent manufactured by San Nopco Co., Ltd.] “Taipec R-930” 20.50〃
Next, 45.00 parts of an aqueous resin dispersion mixture (in terms of solid content) “Dicknate 3111” 0.10〃 [dryer manufactured by Dainippon Ink and Chemicals, Inc.] was added, and the whole was uniformly mixed and dispersed with a stirrer. hand,
A paint having a paint non-volatile content of 51% and a PWC of 31% was obtained.

Application Examples 1 to 6 and Comparative Application Examples 1 to 12 Each of the aqueous coating compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 12, that is, the aqueous coating was applied to various substrates as described below. And subjected to various performance tests.

That is, first, the substrate to be coated is as follows. Substrate a ... Flexible board Substrate b ...
The "Acrydic A-172" [manufactured by Dainippon Ink and Chemicals Incorporated solvent type acrylic resin] was applied so that the 100 g / m ^2, dried allowed, then on the "Loughton Jumbo" [Suzuka Spray tile manufactured by Paint Co., Ltd.)
2,000 g / m ² , which was applied smoothly and dried at room temperature for one week. Base material c: Mild soft steel sheet. It is.

That is, first, a coating method applied to each of the water-based paint series obtained in Examples 1 to 4 and Comparative Examples 1 to 6, and the above-described base material a or b was applied at room temperature. Then, apply the paint to 120 g / m ² and dry it all day and night, apply it again to 80 g / m ² and dry it at room temperature for 7 days to obtain a cured coating film. It is a painting method of obtaining.

Next, a coating method applied to each of the water-based paint series obtained in Example 5 and Comparative Examples 7 to 10, wherein the substrate a described above was heated to a surface temperature of 60 ° C., respectively. Preheat, apply the paint to 120 g / m ² here, heat and dry for 10 minutes in an atmosphere of 100 ° C., cool to room temperature for 5 minutes, and then add 80 g / m ^2, and dried under heating at 100 ° C. for 10 minutes, and then dried at room temperature for 7 days to obtain a cured coating film.

Further, the coating method obtained in Example 6 and Comparative Examples 11 and 12 was applied to each of the water-based paint series, except that the above-described base material c was changed to use the above-described base material. This is a coating method in which the coating method applied to each series of water-based paints obtained in Example 5 and Comparative Examples 7 to 10 is similarly repeated.

Then, for each of the test pieces obtained as described above, the painted surface was left, and the other surface was coated with urethane.
After sealing with an acrylic sealing agent, it was subjected to the evaluation of various coating film properties as described below.

That is, the evaluation of the coating film performance was performed in the following manner.

Water resistance: immersed in tap water for 2 months, and then visually checked the change of the coating. Alkali resistance: 2 months in a 2% aqueous sodium hydroxide solution saturated with calcium hydroxide. After immersion, the change state of the coating film was visually determined. Acid resistance… After immersion for one month in 0.2% sulfuric acid aqueous solution, the change state of the coating film was visually determined. Properties: Immerse in water and repeat the cycle of cooling and heating at -20 ° C for 4 hours and at + 40 ° C for 4 hours for 30 cycles. Accelerated weathering was determined by… QUV weatherometer, and the gloss retention rate (%) after a predetermined period of time was indicated by the actual exposure test… for two years in the suburbs of Takaishi City, Osaka Prefecture
After the outdoor exposure, the state of contamination of the coating film and the like were visually determined, and evaluation was made from both the stain resistance and the change state of the coating film.

The results are shown separately in Tables 2 and 3.

[Effects of the Invention] As described above, the aqueous coating composition of the present invention is an aqueous resin dispersion obtained by emulsion-copolymerizing monomers mainly composed of a fluoroolefin, and the weather resistance of the film and With excellent chemical resistance, on the other hand, the aqueous resin dispersion obtained by emulsion-copolymerizing monomers mainly composed of a fluoroalkyl group-containing vinyl monomer, respectively, the water repellency and oil repellency of the film, and In addition to having excellent properties such as contamination resistance of the film, the film has excellent film forming properties and excellent water resistance of the coating film.

Such an aqueous coating composition of the present invention has good compatibility because both aqueous resin dispersions have a fluorine atom, and furthermore, both of these aqueous dispersions have a common property of emulsion polymerization. From the point obtained by the polymerization method, compared with those obtained by the polymerization method in another solvent solution, the unique effects of the present invention are exhibited, which are derived from various advantages that the molecular weight is significantly higher. It is a testimony of everything.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-137365 (JP, A) JP-A-2-70706 (JP, A) JP-A-60-192769 (JP, A) JP-A-1- 198653 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 27/12-27/20 C09D 127/12-127/20

Claims (7)

(57) [Claims] An aqueous coating composition comprising, as essential components, a fluoroolefin-based aqueous resin dispersion (A) and a fluoroalkyl group-containing aqueous resin dispersion (B),
Moreover, a fluoroalkyl group-containing aqueous resin dispersion (B)
However, the content of unsaturated carboxylic acid in all monomers is 0.
2 to 4% by weight and / or a cross-linkable monomer copolymerized within a range of 0.05 to 2% by weight in all monomers. Composition. 2. The fluoroolefin-based aqueous resin dispersion (A) has an unsaturated carboxylic acid content of 0.2 to 4% by weight in all monomers and / or a total amount of a crosslinkable monomer in all monomers. The aqueous coating composition according to claim 1, wherein the aqueous coating composition is copolymerized within a range of a content of 0.05 to 2% by weight in the monomer. 3. The method according to claim 1, further comprising a pigment.
Or the aqueous coating composition according to 2. 4. The mixing ratio of the above-mentioned fluoroolefin-based aqueous resin dispersion (A) and the above-mentioned fluoroalkyl group-containing aqueous resin dispersion (B) is such that the solid content weight% ratio (A) :( B) = 20: 80-95: 5, Claim 1,
4. The aqueous coating composition according to 2 or 3. 5. The above-mentioned fluoroolefin-based aqueous resin dispersion (A) contains a fluoroolefin and a copolymerizable vinyl monomer in a total content of 100 to 100% by weight and a fluoroolefin content of 10 to 70%. The aqueous coating composition according to any one of claims 1 to 4, which is an emulsion copolymer containing the copolymerizable vinyl monomer in an amount of 90 to 30% by weight. 6. The fluoroalkyl group-containing aqueous resin dispersion (B) comprises a fluoroalkyl group-containing vinyl monomer and a copolymerizable vinyl monomer in a total amount of 100% by weight.
The content of the fluoroalkyl group-containing vinyl monomer is from 5 to 80% by weight, and the content of the copolymerizable vinyl monomer is from 95 to
It is an emulsion copolymer contained within a range of 20% by weight,
The aqueous coating composition according to claim 1. 7. The above-mentioned fluoroolefin-based aqueous resin dispersion (A) comprises a fluoroolefin, vinyl ether and / or vinyl ester, and if necessary,
α-olefins having a fluoroolefin content of 10 to 70% by weight and a vinyl ether and / or vinyl ester content of 90 to
An emulsion copolymer containing 30% by weight of α-olefins in a range of 0 to 30% by weight.
7. The water-based coating composition according to any one of 6.