JP3518801B2 - Paint composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition which forms a coating film capable of exhibiting low stainability from an early stage after coating.

[0002]

2. Description of the Related Art Conventionally, outdoor substrates (for example, buildings, displays, guard fences, machines, vehicles, etc.)
An outdoor paint having excellent weather resistance is applied to the above for the purpose of decoration or protection. However, with conventional paints, the surface of the resulting paint is exposed to exhaust gas, dust, iron powder,
There is a drawback that the coating film is apt to become dirty due to the influence of rain, sun rays and the like and the coating film appearance is deteriorated.

On the other hand, the present applicant has proposed that an organosilicate and / or a condensate thereof be blended with a coating composition to form a coating film having self-cleaning property and hardly stains (International Publication WO94 / 06870). However,
Depending on the weather at the time of coating or immediately after coating, the hydrolysis of the organosilicate in the coating film does not proceed smoothly and there is a problem that it easily becomes dirty until the self-cleaning property is exhibited. Although the initial stain disappears over time, it tends to be a creme from the customer, and it has been desired to exhibit self-cleaning properties from an early stage immediately after coating.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that organosilicates and / or their condensates and surfactants or boric acid compounds exhibiting acidity in specific amounts. The present invention has been found that the coating composition to be blended can form a coating film capable of exhibiting low stainability from an early stage after coating, and that the coating film also has excellent interlayer adhesion to the underlying surface. .

That is, the present invention provides a coating composition comprising (A) the following general formula:

[0006]

[Chemical 2] (Wherein R is the same or different and represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), and an organosilicate and / or a condensate thereof is used as a resin solid in a coating composition. 0.1 to 50 parts by weight per 100 parts by weight, and (B) a surfactant or boric acid-based compound exhibiting an acidity of 0.1 to 100 parts by weight of organosilicate and / or its condensate (A) solid content. The present invention provides a coating composition characterized by being mixed in an amount of 1 to 50 parts by weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The organosilicate and / or its condensate (A) used in the present invention is represented by the above formula, wherein R in the formula is, for example, an alkyl group,
An aryl group and the like are exemplified.

When R is an alkyl group, it may be linear or branched type, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl. , N-pentyl, i-pentyl, neopentyl, n-hexyl, i-hexyl, n-octyl groups and the like, among which a lower alkyl group having 1 to 4 carbon atoms is preferable. When R is an aryl group, it may be either monocyclic or polycyclic, and examples thereof include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group. Among them, a phenyl group is preferable.

Specific examples of the organosilicate include tetrahydroxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, and the like.
Examples thereof include dimethoxydiethoxysilane. You may use these 1 type or in combination of 2 or more types.

The above-mentioned organosilicate condensate is a branched or straight chain condensate of organosilicates represented by the above-mentioned general formula and having a degree of condensation of 2 to 1
00 is preferable, and specifically, the formula:

[0011]

[Chemical 3] (In the formula, R has the same meaning as described above, and n is 2 to 100.
A condensate represented by (denoting an integer) is preferable. n is 100
If it exceeds the range, the effect of stain resistance becomes small, which is not preferable. As the condensate of the organosilicate, it is particularly preferable that R is a lower alkyl group having 1 to 4 carbon atoms and the degree of condensation is 2 to 15.

In the present invention, when the above organosilicate and / or its condensate (A) is blended with an aqueous coating composition, the organosilicate and / or its condensate is reacted with a polyalkylene glycol compound. You may mix | blend as a modified organosilicate.

The modified organosilicate is obtained by partially reacting an alkoxysilyl group in the above organosilicate and / or a condensate thereof with a polyalkylene glycol-based compound, and the polyalkylene glycol-based compound is represented by the general formula R ₁ O- (R ₂ O) nH (wherein R ₁ is a hydrogen atom, an alkyl group or an aryl group,
R ₂ is represented by an alkylene group having 2 to 4 carbon atoms, and n represents 2 to 60), and for example, polyalkylene glycol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol; methoxy polyethylene glycol, Alkoxy polyalkylene glycols such as ethoxy polyethylene glycol, ethoxy polypropylene glycol and ethoxy polybutylene glycol; polyoxyalkylene alkylphenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Oxyethylene nonyl phenyl ether is preferred.

The reaction of the above-mentioned organosilicate and / or its condensate with a polyalkylene glycol compound is
It is carried out by a dealcoholization reaction by heating. At this time, a catalyst may be added to accelerate the reaction. The catalyst can be used without particular limitation as long as it promotes an exchange reaction between an alkoxysilyl group and an alcohol, and examples thereof include organotin compounds such as butyltin trioctoate and dibutyltin dilaurate, metal alkoxides,
Examples thereof include Lewis acids, organic protonic acids, inorganic protonic acids and the like.

The modified organosilicate contains 0.001 to 0.5 mol, preferably 0.01 to 0 mol, of a polyalkylene glycol compound per 1 mol of the alkoxysilyl group of the organosilicate and / or its condensate. ．
Obtained by reacting 2 moles. When the molar amount is less than 0.001 mol, it becomes difficult to mix into the water-based paint, and when the molar amount exceeds 0.5 mol, hydrolysis of the organosilicate is reduced and the stain resistance is deteriorated, which is not desirable.

In the present invention, the organosilicate and / or its condensate (A) is used in an amount of 0.1 to 50 parts by weight, preferably 1 to 100 parts by weight of the resin solid content in the coating composition.
˜20 parts by weight. If the content is less than 0.1 parts by weight, the stain resistance of the coating film will be poor, and if it exceeds 50 parts by weight, the coating film will become hard and defects such as cracks and lower gloss may occur, which is not preferable.

In the present invention, the acidic surfactant or boric acid compound (B) has a function of promoting the hydrolysis of the organosilicate and / or its condensate (A), and is particularly limited. As the surfactant (B-1), a surfactant such as a phosphoric acid ester salt-based surfactant, a sulfonate salt-based surfactant, a sulfuric acid ester salt-based surfactant, or a carboxylate-based surfactant can be used. Examples of the compound (B-2) include boric acid and trialkyl borate.

The above-mentioned phosphate ester type surfactant (B
Examples of -1) include polyoxyethylene phosphate ester, alkyl phosphate ester salt and the like. Examples of the sulfonate-based surfactants include alkyl or alkylbenzene sulfonates such as sodium laurylsulfonate and sodium dodecylbenzenesulfonate; alkylnaphthalenesulfonates such as sodium isopropylnaphthalenesulfonate; alkyldiphenylethersulfonic acid. Examples include salt. Further, examples of the sulfate ester-based surfactant include alkyl or alkylbenzene sulfate, and (poly) oxyethylene alkylphenyl ether sulfate, and examples of the carboxylate-based surfactant include alkyl. Examples thereof include sulfosuccinate. Among these surfactants, a phosphate ester-based surfactant is suitable.

Examples of the trialkyl borate as the boric acid compound (B-2) include trimethyl borate, triethyl borate and tributyl borate.

In the present invention, the organosilicate and / or its condensate (A) and the boric acid compound (B-
It may be blended with 2) in a condensed form. The boric acid-modified organosilicate and its condensate are disclosed, for example, in JP-A-1 / 1999.
As disclosed in Japanese Patent Publication No. 69634, the organosilicate and / or its condensate (A) such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane and their condensates, etc. In addition, orthoboric acid or metaboric acid is heated and reacted in the presence of an alcohol solvent.

In the present invention, the surfactant or boric acid compound (B) is added in an amount of 0.1 to 50 parts by weight, preferably 1 to 50 parts by weight, per 100 parts by weight of the solid content of the organosilicate and / or its condensate (A). Add 30 parts by weight. If the blending amount is less than 0.1, the hydrophilicity from the beginning of the coating becomes difficult to be expressed, while if it exceeds 50 parts by weight, the use period is shortened and gloss is deteriorated, which is not preferable.

In the present invention, the coating composition containing the organosilicate and / or its condensate (A) and the surfactant or the boric acid compound (B) is an organic solvent system, an aqueous system, a powder, etc. Each form is included.

The organic solvent-based paint may be either a reaction-curing type or a non-cross-linking type, and the reaction-curing type paint is a curable resin capable of forming a cross-linking coating film structure by itself reaction-curing. A composition obtained by dissolving or dispersing the composition in an organic solvent, for example, a fluorine-containing resin, an acrylic resin, a polyester resin, an alkyd resin, a hydroxyl group-containing resin such as a silicone resin as a base resin, and A coating material containing a curable resin composition comprising a cross-linking agent such as polyisocyanate and amino resin can be mentioned. Further, a curable resin composition obtained by using a resin or a resin mixture containing a silanol group and / or a hydrolyzable silyl group, a hydroxyl group and an epoxy group as essential functional group components as a base resin and adding a curing catalyst thereto. Paints containing it are also included. Further, the non-crosslinking type coating composition is a solution type or dispersion type coating composition which forms a coating film when an organic solvent is volatilized at room temperature or by heating, for example, a cellulose derivative type coating material, an acrylic resin type coating material, a urethane resin. Examples thereof include system paints, vinyl chloride resin paints, fluororesin paints, alkyd resin paints, vinyl acetate resin paints, and styrene-butadiene resin paints.

The water-based paint may be either a cross-linked type or a non-cross-linked type, and a conventionally known paint containing a water-dispersible resin or a water-soluble resin can be used. As the water-dispersible resin or the water-soluble resin, Is a cross-linking system using a carbonyl group and a hydrazide group as disclosed in, for example, JP-A-4-249587 and JP-A-7-11193, and JP-A-10-219.
A combination of an acrylic resin emulsion or an acrylic urethane resin emulsion, which is a cross-linking system with a hydroxyl group and an isocyanate group, and a cross-linking agent as disclosed in Japanese Patent Publication No. 190, and an acrylic resin emulsion other than these,
Vinyl acetate emulsion, vinyl acetate-acrylic resin emulsion, ethylene-vinyl acetate emulsion, silicone acrylic emulsion, epoxy resin emulsion, alkyd resin emulsion, urethane resin emulsion, polyurethane emulsion, water-soluble acrylic resin, polyvinyl alcohol, natural or synthetic rubber Examples include latex and the like.

The coating composition of the present invention may further contain a colorant, a filler, a flow regulator, a plasticizer, a curing catalyst, if necessary.
You may mix | blend the additives for paints, such as a ultraviolet absorber.

The coating composition of the present invention can be applied to various material surfaces and coated surfaces thereof, and the coating can be carried out by brush coating, spray coating, roller coating, various coat coating, etc. Can be performed by a conventional method. The coating amount is 2 to 100 μm, preferably 10 to 40 μm in dry film thickness.

[0027]

EXAMPLES The present invention will be described in more detail with reference to examples. In the following, "part" and "%" mean "part by weight" and "% by weight", respectively.

Examples 1 to 4 and Comparative Examples 1 to 8 Each commercially available coating material shown in Table 1 was treated with organosilicate and / or its condensate, acidic surfactant or boric acid compound.
Each coating material was prepared by mixing and stirring with the described composition (amount used with respect to coating resin solid content). Note that (Note 1) to (Note 7) in Table 1 are as follows. (Note 1) “Aresletan”: Kansai Paint Co., Ltd., solvent-type acrylic urethane resin paint (Note 2) “Ares Aquaretane”: Kansai Paint Co., Ltd.
Crosslinkable water-based acrylic urethane resin coating (Note 3) "ES48": Corconate's low condensation product of ethyl silicate (Note 4) Modified organosilicate: Stirrer, thermometer, reflux pipe, nitrogen introduction pipe, water separation In a reaction vessel equipped with a vessel, 500 g of "ethyl silicate 48" (manufactured by Tama Chemical Co., Ltd.), "N"
ewcol 568 "(manufactured by Nippon Emulsifier Co., Ltd., polyoxyethylene nonylphenyl ether) 324.5 g," Sc
"at24" (manufactured by Sankyoki Gosei Co., Ltd.) was charged, and the temperature was raised to 120 ° C while stirring in a nitrogen atmosphere, then raised to 160 ° C over 4 hours and kept at the same temperature for 1 hour. The ethanol that evaporates at that time is 25
g was distilled off to obtain 800 g of modified organosilicate. (Note 5) Boric acid-modified ethyl silicate: In a reaction vessel,
"Ethyl silicate 40" (manufactured by Tama Chemical Co., Ltd.) 744 g,
62 g of orthoboric acid and 178 g of ethyl alcohol
Was added, and this was heated under reflux for 2 hours for reaction. Then, the condensation reaction was carried out for 1 hour while removing the solvent until the amount of the solvent removed reached 316 g, to obtain a boric acid-modified ethyl silicate having a nonvolatile content of 80%. (Note 6) Triethyl borate: Reagent product manufactured by Tokyo Kasei Kogyo Co., Ltd. (Note 7) “PRYSURF A-212E”: Daiichi Kogyo Seiyaku Co., Ltd., acidic phosphate ester

[0029]

[Table 1]

Performance evaluation test "Epomarin primer" (Kansai Paint Co., Ltd., epoxy resin-based undercoating paint) was applied to a zinc phosphate-treated steel plate (0.8 mm thick) so that the dry film thickness was 50 μm.
After drying on the day, "Epomarin intermediate coating" (Kansai Paint Co.,
An epoxy resin-based intermediate coating material was applied to a dry film thickness of 30 μm and dried for 1 day to prepare a test plate. A test plate having the shape shown in FIG. 1 was used for the rain streak stain resistance test. (* 1) Hydrophilicity: A test plate was coated with each of the coating materials of Examples and Comparative Examples so that the dry film thickness was about 20 μm, and the temperature was 20 ° C.
A test coated plate was obtained by drying under conditions of 65% RH for 7 days. This was subjected to a sunshine carbon arc weathermeter for 40 hours, and then the water contact angle (°) of the coating film surface was measured. (* 2) Rain line stain resistance: A test plate having the shape shown in FIG. 1 was coated with each of the paints of Examples and Comparative Examples in the same manner as in (* 1) above to form a test coated plate, which was then used by Ota, Tokyo. In the ward, the north surface was exposed outdoors for 2 months in the state of FIG. 1 and the rain streaks on the vertical part of the test coated plate were observed.

⊚: Rain streak is not recognized ○: Rain streak is slightly recognized Δ: Rain streak is not recognized, but dirt is recognized on the entire surface ×: Rain streak is also seen, and dirt is also recognized on the entire surface (* 3) Self-recoverability: Each test material of Examples and Comparative Examples was applied to a test plate so that the dry film thickness was about 20 μm, and dried for 7 days at 20 ° C. and 65% RH. The paint was repainted so that the dry film thickness was about 20 μm, and dried for 7 days under the conditions of 20 ° C. and 65% RH to obtain a test coated plate. Completely submerge it for 48 hours and pull it up to 2
After a lapse of time, a cross-cut was put and a cello tape was adhered thereto and immediately peeled off, and the surface of the coating film was observed.

◯: Peeling is not recognized Δ: Partial peeling is recognized ×: Peeling is recognized entirely (* 4) Gloss: Each coating material of Examples and Comparative Examples is dried film thickness on a test plate Paint to about 20 μm, 20 ℃ ・ 6
A test coated plate was obtained by drying for 7 days under the condition of 5% RH. The gloss of these coating films was visually observed. ○ indicates good, and × indicates glossy.

[0033]

According to the coating composition of the present invention, a coating film capable of exhibiting a low stain property can be formed from an early stage after coating, and the coating film has excellent interlayer adhesion to the base surface. is there.

[0034]

[Table 2]

[Brief description of drawings]

FIG. 1 is a schematic view of the shape of a test plate used for a rain streak stain resistance test.

Continued front page    (72) Inventor Kazutoshi Nakai               4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture               Kansai Paint Co., Ltd. (72) Inventor Mineyuki Umura               4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture               Kansai Paint Co., Ltd. (72) Inventor Shuichi Kuzuma               4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture               Kansai Paint Co., Ltd.                (56) Reference JP-A-7-286126 (JP, A)                 JP-A-9-194788 (JP, A)                 Japanese Patent Laid-Open No. 4-202481 (JP, A)                 JP-A-5-209148 (JP, A)                 JP-A-55-152751 (JP, A)                 JP-A-59-33351 (JP, A)                 Japanese Patent Laid-Open No. 10-168382 (JP, A)                 JP-A-2-269157 (JP, A)                 JP-A-2-29449 (JP, A)                 JP-A-10-195381 (JP, A)                 JP-A-7-310049 (JP, A)                 JP 64-69364 (JP, A)                 Japanese Patent Publication Sho 45-11713 (JP, B1)                 International Publication 99/05228 (WO, A1)                 International Publication 94/6870 (WO, A1)

Claims (3)

(57) [Claims] 1. A polyisolate having a hydroxyl group-containing resin as a base resin.
In an organic solvent-based coating composition containing a cyanate crosslinking agent ,
(A) The following general formula: (Wherein, R is the same or different and represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), and an organosilicate and / or a condensate thereof is used as a resin solid content in the coating composition. 0.1 to 50 parts by weight per 100 parts by weight, and (B) a boric acid compound in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the solid content of (A). . 2. The coating composition according to claim 1, wherein the boric acid compound (B) is trialkyl borate. 3. The coating composition according to claim 1, wherein the organosilicate and / or its condensate (A) and the boric acid compound (B) are blended in a condensed form.