JP2003019460A - Method of forming stain-resistant coating film, stain- resistant coating film, and stain-resistant organic solvent type coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stain-resistant coating material composition by which a coating film having high hydrophilicy and exhibiting excellent stain-resistance on and right after the formation of the coating film is obtained, and to provide a method of forming the coating film, and a stain-resistant organic solvent type coating material composition. SOLUTION: The coating film is obtained by applying the organic solvent type coating material containing a resin composition and an acetate based organic tin catalyst on a base material so as to have 10-100 μm dry film thickness, wherein a resin composition contains a hydroxyl group-containing fluororesin, a polyisocyanate compound and a fluorine atom-containing silicate compound expressed by formula (1) (in the formula, R<1> s can be the same as or different from each other and are 1-9C organic groups, one of which contains fluorine and which can contain nitrogen atom, oxygen atom and/or chlorine atom, or hydrogen atom. (n) expresses integers of 1-100). The stain-resistant coating film is obtained by the method of forming the stain-resistant coating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a coating film having excellent stain resistance, a coating film, and an organic solvent type coating composition.

[0002]

2. Description of the Related Art A method for forming a coating film having excellent stain resistance by incorporating a silicate compound into a coating material is being developed. These methods are disclosed, for example, in WO94 / 06870, WO96 / 262458, and Kaihei 10-7
It is described in Japanese Patent No. 2569. The stain resistance of such a coating film is exhibited when the silicate compound localized on the surface undergoes a hydrolysis reaction to produce silanol and the coating film becomes hydrophilic.

Since this hydrophilization progresses gradually, a curing period of about 1 to 2 weeks is required after the coating film is formed. Therefore, there is a problem that the stain attached immediately after forming the coating film in a state where the silanol is not sufficiently generated remains without being washed away even if the coating film becomes hydrophilic afterwards, even if it is rained or the like. .

Acids or amines or acid / amine salts have hitherto been used as catalysts in order to accelerate the hydrolysis reaction and accelerate the hydrophilicity of the coating film. However, such a catalyst has a problem that the storage stability of the paint is deteriorated, so that the pot life is sharply deteriorated or the working environment is deteriorated by the odor of the catalyst itself.

Further, in recent years, a silicate compound containing a fluorine atom has been used as a compound having a relatively high hydrolysis rate. However, since it is a fluorine compound having strong hydrophobicity generated during hydrolysis, it was still insufficient in terms of stain resistance immediately after the coating film formation.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to a stain resistant coating composition and a coating forming method capable of obtaining a coating having high hydrophilicity and excellent stain resistance immediately after the coating is formed. It is an object to provide a stain resistant organic solvent type coating composition.

[0007]

DISCLOSURE OF THE INVENTION The present invention is directed to a substrate containing a hydroxyl group-containing fluorine-containing resin, a polyisocyanate compound, and a fluorine atom-containing silicate compound represented by the following general formula 1.

[0008]

[Chemical 3]

(In the formula, R ^{1 s} may be the same or different, but one of them contains a fluorine atom, and each of them may contain a nitrogen atom, an oxygen atom and / or a chlorine atom. An organic group or a hydrogen atom, and n is an integer of 1 to 100), and an organic solvent-based paint containing an acetate-based organic tin catalyst, a dry film thickness of 10 It is a method for forming a stain-resistant coating film, which comprises coating to obtain a coating film having a thickness of 100 μm. Here, after the above-mentioned application, it is left at room temperature for 72
The water contact angle of the coating film after the drying treatment for 50 hours is preferably 50 ° or less, and more preferably the water contact angle of the coating film after the drying treatment for 168 hours is 40 ° or less. Further, it is preferable that the water contact angle is 50 degrees or less after being dried at room temperature for 24 hours and further left at room temperature and 100% humidity for 3 hours.

Further, it is preferable that all of R ¹ contain a fluorine atom. Further, the content of the acetate organotin catalyst is 30 to 300 with respect to the resin composition solid content.
It is preferably ppm and the acetate organotin catalyst is preferably dibutyltin diacetate.

Further, the present invention is a stain resistant coating film obtained by the above method for forming a stain resistant coating film.

Furthermore, the present invention provides a fluorine-containing resin containing a hydroxyl group, a polyisocyanate compound, and a silicate compound containing a fluorine atom represented by the following general formula 1.

[0013]

[Chemical 4]

(In the formula, R ^{1 s} may be the same or different, but one of them contains a fluorine atom, and each of them may contain a nitrogen atom, an oxygen atom and / or a chlorine atom. 9 is an organic group or a hydrogen atom, and n is an integer of 1 to 100.), and 30 to 300 ppm of an acetate organotin catalyst based on the solid content of the resin composition. A stain resistant organic solvent type coating composition characterized by the above.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The organic solvent type coating used in the method for forming a stain resistant coating film of the present invention contains a resin composition containing a hydroxyl group-containing fluorine-containing resin, a polyisocyanate compound and a silicate compound. Examples of the hydroxyl group-containing fluororesin include fluoroolefin copolymers. The resin solid content hydroxyl value of the fluoroolefin copolymer is not particularly limited, but from the viewpoint of curability and flexibility of the obtained coating film, it is 20 to 2
It is preferably 00, more preferably 30 to 150. The number average molecular weight is not particularly limited, but from the viewpoint of curability, weather resistance and coating workability, it is preferably 1000 to 100000, more preferably 1500 to 30000. The number average molecular weight can be measured and determined by a method well known by those skilled in the art, such as GPC (gel permeation chromatography).

Commercially available fluoroolefin copolymers such as these are the Zeffle series (manufactured by Daikin Industries, Ltd.), the Lumiflon series (manufactured by Asahi Glass Co., Ltd.), the Cefraralcoat series (manufactured by Central Glass Co., Ltd.), and Fluoro. Nate series (manufactured by Dainippon Ink and Chemicals, Inc.), Zaflon series (manufactured by Toagosei Co., Ltd.), and the like.

Specific examples of the polyisocyanate compound include 2,4-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate,
Diisocyanates such as xylylene diisocyanate, isophorone diisocyanate, lysine methyl ester diisocyanate, methylcyclohexyl diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, n-pentane-1,4-diisocyanate and norbornene diisocyanate, and trimers of these. Adducts and burettes, polymers of these polymers having two or more isocyanate groups, triisocyanates such as lysine triisocyanate, and those whose isocyanate groups are blocked with alcohols or oximes. Can be mentioned.

The content ratio of the hydroxyl group-containing fluororesin to the polyisocyanate compound in the organic solvent type coating material is from the viewpoint of the curability and performance of the resulting coating film and the hydroxyl group-containing fluororesin and the polyisocyanate compound. The molar ratio (OH / NCO) of the isocyanate compound to the isocyanate group is preferably 2.0 to 0.2, and more preferably 1.3 to 0.7.

The above-mentioned fluorine atom-containing silicate compound is
The compound and / or condensate represented by the general formula (1). In the formula, R ^{1 s} may be the same or different, but one of them contains a fluorine atom, and each of them may contain a nitrogen atom, an oxygen atom and / or a chlorine atom, and has 1 to 9 carbon atoms. It is an organic group or a hydrogen atom.
From the viewpoint of dispersion stability and hydrolyzability, it has 1 to 6 carbon atoms.
It is preferable that the organic group is When the number of carbon atoms is out of the above range, the dispersion stability is lowered, or the stain resistance of the obtained coating film is lowered.

Specific examples of R ¹ include CH ₂ -C
F ₂ —R or CH ₂ CH ₂ —CF ₂ —R (in the formula, R is an organic group which may contain a nitrogen atom, an oxygen atom, a fluorine atom and / or a chlorine atom or a hydrogen atom) Is preferred, and it is more preferred that R has 1 to 3 carbon atoms. Specifically, as such, CH ₂ C
_{F 3, CH 2 CF 2 CF} 3, CH 2 (CF 2) 2 CF 3, CH 2
CH ₂ (CF ₂ ) ₃ CF ₃ , CH ₂ (CF ₂ ) ₂ H, CH ₂ (C
F _{2) 3} H, may be mentioned CH ₂ (CF _{2) 4} H, and the like. From the viewpoint of stain resistance of the obtained coating film, it is more preferable that all R ¹ contain a fluorine atom.

The content of fluorine atoms contained in such a fluorine atom-containing silicate compound is preferably 15% by weight or more, and more preferably 30 to 50% by weight. When the content is less than 15% by weight,
The resulting coating film may have insufficient stain resistance.

The above n represents the degree of polymerization, and
It is an integer of 100. From the viewpoint of volatilization and resin handling, it is preferably 2 to 100, and 4 to 20.
Is more preferable. When n is 2 or more, examples of the shape of the silicate compound include a linear shape, and examples of shapes other than the above formula include a branched chain shape, a cyclic shape, and a three-dimensional polymer. You can

The above-mentioned fluorine atom-containing silicate compound is
For example, Si (OCH ₂ CF ₂ CF ₃ ) ₄ Si (OCH (CF ₃ ) ₂ ) ₄ Si (OCH ₂ CF ₂ CF ₂ H) ₄ Si (OCH ₂ C ₄ F ₈ H) ₄ Si (OCH ₂ CF _{2 CF 3) 2 (OCH 3)} 2 Si (OCH (CF 3) 2) 2 (OCH 3) 2 Si (OCH 2 CF 2 CF 2 H) 2 (OCH 3) 2 Si (OCH 2 CF 2 CF 3) 2 Examples thereof include (OH) ₂ and condensates and cocondensates thereof, and examples of commercially available products include Zeffle GH110 (manufactured by Daikin Industries, Ltd.).

The content of the fluorine atom-containing silicate compound in the organic solvent type coating material is 0.
It is 1 to 80 parts by weight, preferably 1 to 50 parts by weight. If the content is less than 0.1 part by weight, the resulting coating film may have insufficient stain resistance,
If the amount is more than parts by weight, the curability and appearance of the resulting coating film may deteriorate.

Further, the organic solvent type paint used in the method for forming a stain resistant coating film of the present invention contains an acetate type organic tin catalyst. By blending this acetate type organic tin catalyst, the rate of hydrophilization of the obtained coating film can be accelerated. As the acetate-based organic tin catalyst, specifically, dimethyltin diacetate, diethyltin diacetate, dipropyltin diacetate,
Dibutyltin diacetate, diamyltin diacetate, dioctyltin diacetate, didecyltin diacetate, didodecyltin diacetate, dipropenyltin diacetate, etc. can be mentioned tin acetate containing alkyl substituents, etc. , And from the viewpoint of industrial availability, dibutyltin diacetate is preferable. The content of the acetate-based organic tin catalyst is not particularly limited, but it is preferably 30 to 300 ppm with respect to the solid content of the resin composition. When the content is less than 30 ppm, the effect of the present invention may be insufficient, and when it exceeds 300 ppm, the gelation of the coating material is promoted, resulting in a short pot life and poor coating workability. There is a risk of More preferably, it is 30 to 200 ppm.

Further, the organic solvent type coating material used in the method for forming a stain resistant coating film of the present invention includes various organic solvents, color pigments, extender pigments, pigment dispersants, thickeners and surface conditioners in addition to the above components. , A film forming aid, an ultraviolet absorber, an antioxidant, a silane coupling agent, a flame retardant, an antistatic agent, an anticorrosive agent, and the like, which may be contained in various components well known by those skilled in the art.

From the viewpoint of storage stability and pot life, the stain-resistant coating composition of the present invention usually comprises the above-mentioned hydroxyl group-containing fluororesin and, if necessary, other components which do not react with the hydroxyl group as a coating liquid, and , The above polyisocyanate compound, a fluorine atom-containing silicate compound, and optionally other components that do not react with isocyanate or silicate as a curing agent liquid, and further, each is stored separately with an acetate-based organic tin catalyst, immediately before use It is preferable to use them as a mixture.

The method for forming a stain resistant coating film of the present invention is to obtain a coating film by applying the above-mentioned organic solvent type coating material to various substrates. Examples of the base material include, for example, metal base materials of iron, stainless steel, aluminum and the like and surface-treated products thereof,
Cement-based base materials such as cements, limes and gypsum, polyvinyl chlorides, polyesters, polycarbonates,
Examples include plastic base materials such as acrylics. It should be noted that these base materials may be preliminarily subjected to a base treatment with a sealer or a coating film may be formed on the surface thereof with various kinds of coating materials, depending on the type of the base material.

The above-mentioned application is carried out, for example, by spraying, brushing, or coating.
Using a roller, curtain flow, roll, dip, etc.
Thus, it is usually applied by one-time application or two-time application. Na
Two-time coating is just before the purpose of repairing coating film defects.
Applied to all or part of the coating film
It means applying and applying and splicing. One application
There is no particular limitation on the coating amount in the case of, for example, 0.
05-0.5Kg / m ²And 0.08 to 0.3 Kg
/ M²Is preferred.

After coating, it is preferable that the coating film has a water contact angle of 50 degrees or less after being dried at room temperature for 72 hours. When this water contact angle exceeds 50 degrees, stains are likely to adhere immediately after forming the coating film, and it becomes difficult to remove the stains due to rainfall or the like even after a lapse of time, and the stain resistance of the resulting coating film decreases. There is a risk of Preferably, the water contact angle after drying treatment at room temperature for 168 hours is 40 degrees or less.

Further, it is preferable that the coating film has a water contact angle of 50 degrees or less after being dried at room temperature for 24 hours after coating and then left at room temperature and 100% humidity for 3 hours. In addition, the room temperature left at room temperature in this specification means
For example, the temperature is about 5 to about 40 ° C., and the humidity is, for example, 40% or more.

The stain resistant coating film of the present invention is obtained by the method for forming a stain resistant coating film and exhibits excellent stain resistance immediately after the coating film is formed.

Further, the stain resistant organic solvent type coating composition of the present invention is an organic solvent type coating used in the above method for forming a stain resistant coating film, and the obtained coating film is an excellent stain resistant coating film. Can be formed.

[0034]

Example 1 Zeffle GK510 (manufactured by Daikin Industries, Ltd., hydroxyl group- and carboxyl group-containing tetrafluoroolefin copolymer, solid content 50% by weight) 20.0 parts by weight, Taipaque C
34.0 parts by weight of R-95 (titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.), 3.0 parts by weight of butyl acetate and 3.0 parts by weight of xylene were charged into a tin container and stirred for about 30 minutes. The contents were transferred to a vessel for dispersion, glass beads were charged in an appropriate amount, and then beads were dispersed by a sand grind mill at 2000 rpm for about 1 hour. After removing the beads, 60.0 parts by weight of the obtained white dispersion paste was weighed into another tin container, and Zeffle GK500 (manufactured by Daikin Industries, Ltd., hydroxyl group-containing tetrafluoroolefin copolymer, solid content 60)
40.0 parts by weight) was gradually added with stirring, and then the mixture was stirred and mixed for about 15 minutes to obtain a white coating liquid 1.

Coronate HX (manufactured by Nippon Polyurethane Industry Co., isocyanurate of isophorone diisocyanate, solid content 100% by weight) 7.17 parts by weight, Zeffle G
Into a tin container, 5.1 parts by weight of H110 (manufactured by Daikin Industries, Ltd., fluorine atom-containing silicate compound, 100% by weight of active ingredient) and 10.0 parts by weight of butyl acetate were charged.
Stirring and mixing with a disper for about 15 minutes gave a hardening agent liquid 1.

Next, 100.0 parts by weight of the coating liquid 1, 22.27 parts by weight of the curing agent liquid 1, and SCAT-8 (dibutyltin diacetate manufactured by Sankyosha Co., Ltd., 100% by weight of the active ingredient) were added to the resin composition solid. It was added so as to be 50 ppm with respect to the amount, and was stirred and mixed with a disper for about 5 minutes to obtain a stain resistant coating composition 1. Furthermore, the paint viscosity of Ford Cup No. 1 was reduced with Duflon thinner (a painter of Nippon Paint Co., Ltd., a normally dry organic solvent-based thinner). It was diluted to 4 at 20 seconds / 20 ° C.

Further, the surface-treated aluminum plate (9
Hypon 20 dechro gray paint (30 × 0.7 cm) (Nippon Paint Co., Ltd., a normal-drying organic solvent based undercoat paint)
To a dry film thickness of 40 μm and dried at room temperature for 24 hours, and then a DUFRON 4F intermediate coating white paint (manufactured by Nippon Paint Co., Ltd., normally dry organic solvent-based intermediate coating paint) is dried to a film thickness of 25
It was applied so as to have a thickness of μm and dried at room temperature for 24 hours to obtain a base material.

The substrate thus obtained was diluted with the stain resistant coating composition 1 by air spray to obtain a dry film thickness of 25 μm.
Was applied to prepare a test coated plate.

Example 2 The amount of SCAT-8 was 150 p based on the solid content of the resin composition.
A stain resistant coating composition 2 was obtained in the same manner as in Example 1 except that pm was used, and then diluted in the same manner to prepare a test coated plate.

Comparative Example 1 A stain resistant coating composition 3 was obtained in the same manner as in Example 1 except that SCAT-8 was not used, and then a test coated plate was prepared.

Comparative Example 2 A stain resistant coating composition 4 was obtained in the same manner as in Example 1 except that 150 ppm of dibutyltin dilaurate was added to the resin solid content instead of SCAT-8. A coated plate was prepared.

Comparative Example 3 The amount of SCAT-8 was 500 p based on the solid content of the resin composition.
A stain resistant coating composition 5 was obtained in the same manner as in Example 1 except that pm was used, and then a test coated plate was further prepared.

<Evaluation Test> The following evaluation tests were conducted on the stain resistant coating compositions and the test coated plates obtained in Examples 1 and 2 and Comparative Examples 1 to 3. The evaluation results are shown in Table 1. In addition, the environment that is left at room temperature is 20 ° C,
The humidity was 65%.

Pot life Each diluted stain resistant coating composition was allowed to stand at 20 ° C. for 8 hours, and the viscosity of the paint after standing was measured. The paint having a viscosity of the paint after standing still less than twice the viscosity of the paint before standing was regarded as acceptable (◯).

Hydrophilicity condition (a): After coating, the hydrophilicity of the surface of each test coated plate after standing at room temperature and drying treatment for each time was evaluated by measuring the water contact angle. A value of 50 degrees or less was regarded as good.

Condition (b): The hydrophilicity of the surface of each test coated plate was evaluated by measuring the water contact angle after standing for 24 hours at room temperature after coating and further for 3 hours at room temperature and 100% humidity. A value of 50 degrees or less was regarded as good.

Stain resistance test A coated plate was further dried at room temperature for 24 hours, and the chromaticity (L value, a value, b value) was measured by an SM color computer SM-7 (manufactured by Suga Test Instruments Co., Ltd.). After doing, JI
Contamination exposure according to S Z 2381 6.2.1 was performed, and the color difference (ΔE) after 1 month was measured. ΔE is 1.0
The following were accepted.

[0048]

[Table 1]

As is clear from Table 1, the stain resistant coating composition of the present invention was found to have high hydrophilicity and excellent stain resistance immediately after the coating film was formed (Examples 1 and 2).
However, it was found that those containing no acetate-based organotin catalyst had low hydrophilicity immediately after coating film formation, and also had insufficient stain resistance (Comparative Examples 1 and 2). Further, it was found that when the amount of the acetate type organic tin catalyst was more than the predetermined amount, the pot life was reduced (Comparative Example 3).

[0050]

EFFECT OF THE INVENTION Since the method for forming a stain resistant coating film of the present invention uses a urethane curable coating composition containing a fluorine atom-containing silicate compound and a specific range amount of an acetate organotin catalyst, it is treated with an acid. Without this, a coating film having excellent hydrophilicity can be obtained immediately after the coating film is formed, and a coating film having excellent stain resistance can be obtained. It is considered that this is because the acetate organotin catalyst serves as a hydrolysis catalyst for the silanol of the silicate compound containing a fluorine atom. Therefore, a long curing period is unnecessary, and a coating film having high hydrophilicity can be formed immediately after the coating film is formed. Further, it is considered that the dirt attached immediately after forming the coating film can be washed away by the rainfall.

According to the method for forming a stain resistant coating film of the present invention,
In a stain resistant coating formed from a coating containing a fluorine atom-containing silicate compound, it is possible to prevent deterioration of the stain resistance due to stains immediately after the coating is often seen as a problem, and further expand the market. be able to.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryozo Takakawa             19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan             Into Inc. F-term (reference) 4D075 CA34 EB16 EB43                 4J038 CD091 DG032 DG262 DG302                       DL022 GA02 GA03 GA08                       GA12 JA05 JA55 JC39 KA04                       MA09 NA05 NA26 NA27 PA19                       PA20 PB14 PC02 PC04 PC08

Claims (9)

[Claims] 1. A fluorine-containing resin containing a hydroxyl group, a polyisocyanate compound, and a silicate compound containing a fluorine atom represented by the following general formula 1 with respect to a substrate. (In the formula, R ^{1 s} may be the same or different, but one of them contains a fluorine atom, and each of them may contain a nitrogen atom, an oxygen atom and / or a chlorine atom.
Is an organic group or a hydrogen atom, and n is an integer of 1 to 100. Stain resistance, characterized in that a coating composition is obtained by applying a resin composition containing) and an organic solvent-based coating material containing an acetate-based organic tin catalyst to a dry film thickness of 10 to 100 μm. Coating film forming method. 2. The method for forming a stain-resistant coating film according to claim 1, wherein the coating film has a water contact angle of 50 degrees or less after being dried at room temperature for 72 hours after the coating. 3. The water contact angle of the coating film after the coating, after being dried at room temperature for 168 hours, is 40 degrees or less.
The method for forming a stain-resistant coating film according to 1. 4. The coating film has a water contact angle of 50 degrees or less after being dried at room temperature for 24 hours after the coating and then left at room temperature and 100% humidity for 3 hours. The method for forming a stain-resistant coating film according to 1. 5. The method for forming a stain resistant coating film according to claim 1, wherein all R ^1's contain a fluorine atom. 6. The content of the acetate-based organic tin catalyst is 30 to 300 ppm with respect to the solid content of the resin composition.
The method for forming a stain resistant coating film according to any one of claims 1 to 5. 7. The method for forming a stain resistant coating film according to claim 1, wherein the acetate type organic tin catalyst is dibutyltin diacetate. 8. A stain resistant coating film obtained by the method for forming a stain resistant coating film according to any one of claims 1 to 7. 9. A fluorine-containing resin containing a hydroxyl group, a polyisocyanate compound, and a silicate compound containing a fluorine atom represented by the following general formula 1. (In the formula, R ^{1 s} may be the same or different, but one of them contains a fluorine atom, and each of them may contain a nitrogen atom, an oxygen atom and / or a chlorine atom.
Is an organic group or a hydrogen atom, and n is an integer of 1 to 100. ) -Containing resin composition, and an acetic acid organotin catalyst in an amount of 30 to 30% with respect to the resin composition solid content.
A stain-resistant organic solvent-based coating composition containing 300 ppm.