JP2003034771A - Stain-resistant coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating film capable of maintaining good stain resistance for a long period of time. SOLUTION: The coating composition comprises (A) a hydroxy-group- containing acrylic polymer having a ladder-silicone oligomer at a side chain and/or a terminal,(B) a fluorine-containing polymer consisting of (i) 40-90 mol% of a fluoro-olefin expressed by a general formula CF2 =CXY (wherein X is H or F, and Y is H, Cl, F or CF3 ), (ii) 1-30 mol% of a hydroxy-group-containing vinyl monomer, and (iii) 1-30 mol% of a monomer copolymerizable with the above monomers, and (C) a polyisocyanate compound.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint containing a hydroxyl group-containing acrylic polymer having a ladder type silicone oligomer in a side chain and / or a terminal, a fluorine-containing polymer and a polyisocyanate compound. The present invention relates to a resin composition for use. ADVANTAGE OF THE INVENTION According to this invention, the coating film which can maintain excellent stain resistance for a long term can be provided. 2. Description of the Related Art A coating material comprising a hydroxyl group-containing acrylic polymer having a ladder type silicone oligomer at a side chain and / or a terminal (hereinafter, may be simply referred to as "acrylic silicone hybrid polymer") has a low stain resistance. In recent years, it has been widely used in various fields because it can form an excellent coating film. [0003] However, in the field of paints, there is an increasing demand for higher quality and higher performance than ever before, and the conventional paints using acrylic silicone hybrid polymers have been demanded. Nevertheless, further improvement in coating film properties is desired. In particular, it has been found that a coating composed of a conventional acrylic silicone hybrid polymer cannot maintain the stain resistance of the coating film for a long time. The inventors of the present invention have conducted intensive studies in view of the above points. As a result, it has been found that, when a specific fluorine-containing polymer is added to an acrylic silicone hybrid polymer, and a resin composition for coatings further containing a polyisocyanate compound is used, excellent results are obtained. It has been found that a coating film capable of exhibiting excellent stain resistance for a long period of time can be formed, and the present invention has been completed. [0005] That is, the present invention provides:
(A) a hydroxyl group-containing acrylic polymer having a ladder type silicone oligomer in a side chain and / or a terminal, (B)
(I) 40 to 90 mol% of a fluoroolefin represented by the general formula CF ₂ ＣCXY (where X is H or F, and Y is H, Cl, F or CF ₃ ), and (ii) hydroxyl group-containing 1 to 30 mol% of a vinyl monomer, and (iii)
The present invention relates to a resin composition for a paint, comprising a fluoropolymer comprising 1 to 30 mol% of a monomer copolymerizable therewith, and (C) a polyisocyanate compound. DETAILED DESCRIPTION OF THE INVENTION <Component (A)> The "ladder type silicone oligomer" in a hydroxyl group-containing acrylic polymer having a ladder type silicone oligomer in a side chain and / or a terminal has the following basic structure: (In the formula, the substituent R is at least one substituent R ¹ selected from non-reactive substituents such as hydrogen, an alkyl group and a phenyl group, and a group having a carbon-carbon double bond, a thiol group, and the like. reactivity of at least one selected from the substituent group consists of substituents R ^2, n is an integer of 10 to 80)
Is a compound having [0007] Thus, the ladder-type silicone oligomer as a substituent R, substituent R ¹ is a non-reactive substituent
And a substituent R ² that is a reactive substituent, and the presence of the substituent R ² allows the acrylic monomer or the like constituting the acrylic polymer to react with the ladder-type silicone oligomer. Becomes possible. here,
During all substituents R, preferably the substituent R ² is one to two, more preferably 1.3 to 1.8 pieces. If the substituent R ² is too large, the acrylic polymer tends to gel, while if the substituent R ² is too small, the ladder-type silicone oligomer will be converted into the side chain of the acrylic polymer and / or
Or it becomes difficult to incorporate into the terminal. [0008] Further, in the ladder type silicone oligomer, if n is less than 10, the weather resistance and stain resistance characteristic of silicone may not be sufficiently exhibited. The reactivity with the system monomer, the compatibility, the alkali resistance of the coating film, the recoating property and the like are deteriorated. The acrylic silicone hybrid polymer of the present invention can be synthesized by various methods. For example, R ¹ Si (OR ′) ₃ or R ¹ SiCl ₃ (where R ^1
1 is the above-mentioned non-reactive substituent, and R 'is an alkyl group or a phenyl group);
Condensing with a silane compound represented by ² Si (OR ′) ₃ or R ² SiCl ₃ (where R ² is a reactive substituent described above and R ′ is an alkyl group or a phenyl group); It can be produced by reacting the obtained ladder type silicone oligomer with an acrylic polymer having a hydroxyl group. The above R ¹ Si (OR ′) ₃ includes lower alkyl-trialkoxysilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane and ethyltriethoxysilane. For example, KBM-13 manufactured by Shin-Etsu Chemical Co., Ltd. can be used. Examples of R ¹ SiCl ₃ include alkyltrichlorosilanes such as methyltrichlorosilane and ethyltrichlorosilane, and specifically, KA-13 manufactured by Shin-Etsu Chemical and the like can be used. Furthermore, R ²
As Si (OR ′) ₃ , γ-methacryloxypropyltrimethoxysilane (specifically, KB
A thiol group such as a substituted trialkoxysilane having a vinyl substituent such as E-503 or vinyltriethoxysilane, or γ-mercaptopropyltrimethoxysilane (specifically, KBM-803 manufactured by Shin-Etsu Chemical). Substituted trialkoxysilanes and the like can be mentioned. The ladder type silicone oligomer is
When the substituent R ² contains a group having a carbon-carbon double bond, the ladder-type silicone oligomer and the acrylic monomer component are copolymerized, so that the ladder-type silicone oligomer is added to the side chain of the acrylic polymer. Will exist. On the other hand, if it has a thiol group as a substituent R ² is a ladder-type silicone oligomer will be present at the terminal of the acrylic polymer. Thus, in the present invention, the ladder-type silicone oligomer may be present on the side chain or at the terminal of the hydroxyl group-containing acrylic polymer, or may be present on both the side chain and the terminal. You may. Further, examples of the acrylic monomer having a hydroxyl group to be reacted with the ladder type silicone oligomer include alcoholic hydroxyl group-containing vinyl monomers such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. . Further, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, (meth)
Ester compound of acrylic acid or methacrylic acid such as stearyl acrylate and a monohydric alcohol having 1 to 22 carbon atoms, styrene, vinyltoluene, α-methylstyrene,
Vinyl monomers such as acrylonitrile, vinyl acetate, and vinyl chloride may be copolymerized with the acrylic monomer having a hydroxyl group as long as the performance is not impaired. In addition,
Each of these monomers may be used alone,
Two or more kinds may be used in combination. Further, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid and maleic anhydride; epoxy group-containing monomers such as glycidyl (meth) acrylate; N-methylol (meth) acrylamide;
A monomer having another functional group other than a hydroxyl group such as dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, vinyl sulfonic acid, and vinyl sulfonyl chloride can also be copolymerized. These monomers may be used alone or in combination of two or more. The acrylic silicone hybrid polymer as the component (A) of the present invention contains a hydroxyl group as a curing site, and is cured by the component (C) described below. <Component (B)> The component (B) of the coating resin composition of the present invention comprises (B) (i) a fluoroolefin,
(Ii) a hydroxyl group-containing vinyl monomer, and (iii)
It is a fluoropolymer comprising a monomer copolymerizable therewith. Here, the fluoroolefin is a compound represented by the general formula CF ₂ ＣCXY (where X is H or F, and Y is H, Cl, F or CF ₃ ). It is an olefin having at least two fluorine atoms. For example, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropene and the like can be mentioned. These fluoroolefins are
Each may be used alone, or two or more kinds may be used in combination. Examples of the hydroxyl group-containing vinyl monomer include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, and ethylene glycol monoallyl ether. It is preferable to use 4-hydroxycyclohexyl vinyl ether or hydroxybutyl vinyl ether from the viewpoint of compatibility with the resin. In addition, these monomers are
Each may be used alone, or two or more may be used in combination. Further, the monomer components (i) and (i)
The monomer copolymerizable with i) is not particularly limited, and includes, for example, alkyl vinyl ethers, (meth) acrylates, olefins, haloolefins,
Vinyl carboxylate and the like can be used.
Specific examples include isopropyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, cyclohexyl (meth) acrylate, butyl (meth) acrylate, vinylidene chloride, vinyl acetate, n-vinyl butyrate, ethylene, propylene, and the like. be able to. Among these,
From the viewpoint of weather resistance and compatibility, (meth) acrylic acid cyclohexyl ester, isopropyl vinyl ether and the like are preferable. These monomers may be used alone or in combination of two or more. The fluorine-containing polymer of the present invention contains 40 to 90 mol% of the monomer component (i) which is a fluoroolefin, and 1 to 30 mol% of the monomer component (ii) which is a hydroxyl group-containing vinyl monomer. The monomer component (iii), which is a possible monomer, is contained in a proportion of 1 to 30 mol%. When the proportion of the monomer component (i) is less than 40 mol%, when used as a paint base,
It is not preferable because sufficient stain resistance, chemical resistance and weather resistance cannot be obtained. On the other hand, when the content is more than 90 mol%, the solubility in various solvents decreases, and it becomes difficult to use the composition as a paint base. If the proportion of the monomer component (ii) is less than 1 mol%, the curing reaction becomes difficult to occur, and the solvent resistance and chemical resistance of the cured coating film are undesirably reduced. Also, 30
If it is more than mol%, the copolymerization reaction becomes difficult, which is not preferable. When the proportion of the monomer (iii) is less than 1 mol%, the storage stability of the resin solution is lowered, and
If the amount is more than mol%, the polymerization rate during the polymerization is undesirably reduced. The fluoropolymer used in the present invention is:
It can be produced by copolymerizing a monomer mixture consisting of a predetermined ratio using a polymerization initiator in the presence or absence of a solvent. As the polymerization initiator, a water-soluble one or an oil-soluble one is appropriately used depending on the type of polymerization and the kind of solvent used as required. The amount of these polymerization initiators used is appropriately selected depending on the type thereof, copolymerization reaction conditions, and the like.
It is selected in the range of 0.005 to 5% by weight, preferably 0.1 to 1%. The polymerization method is not particularly limited, and for example, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method and the like can be used. However, among these, a solution polymerization method using a ketone such as methyl ethyl ketone, an ester such as ethyl acetate, a saturated halogenated hydrocarbon having at least one fluorine atom as a solvent, an emulsion polymerization method in an aqueous medium, etc. Is preferably used. The fluorine-containing polymer of the present invention, like the acrylic silicone hybrid polymer of the component (A), contains a hydroxyl group as a curing site, and is cured by the component (C) described below. Here, the compounding amounts of the components (A) and (B) are based on the total of the components (A) and (B).
It is preferable that the component (A) be 5 to 95% by weight (solid content) and the component (B) be 95 to 5% by weight (solid content).
(A) The component is set to 10 to 50% by weight (solid content), and (B)
It is more preferred that the component be 90 to 50% by weight (solid content). If the amount of the component (A) is too small, the stain resistance of the resulting coating film will be insufficient. On the other hand, if the amount of the component (A) is too large, the recoating property and alkali resistance of the resulting coating film will decrease. Would. The viscosity of the component (A) is 5 butyl acetate.
500-3000 mPa · s (20 ° C) with 0wt% solution
It is more preferably 800 to 1500 mPa · s (20 ° C.) from the viewpoint of workability and finish appearance. Further, the viscosity of the component (B) is 50 to 500 mPa · s (20 ° C.) in a 30 wt% solution of butyl acetate.
It is more preferably 80 to 200 mPa · s (20 ° C.) from the viewpoint of compatibility and finish appearance. <Component (C)> The component (C) used in the present invention.
The polyisocyanate compound as a component is not particularly limited as long as it has two or more isocyanate groups, and a coating film requiring hardness, elongation, adhesion, weather resistance, abrasion resistance, etc. of the coating film is required. What is necessary is just to select suitably from well-known things according to performance. For example, 1,6-hexamethylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, isophorone diisocyanate (IPDI),
Norbornane diisocyanate (NBDI), methyl-
2,6-diisocyanate hexanoate (lysine diisocyanate, LDI), 2-isocyanateethyl-
Examples include 2,6-diisocyanate caproate (lysine triisocyanate, LTI), or a modified form of the above polyisocyanate compound, such as a nurate or buret form. Among them, a polyisocyanate having a non-yellowing type diisocyanate, an adduct thereof, and an isocyanate is particularly preferable. Specifically, Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.
Etc. can be used. Further, in the resin composition for a coating material of the present invention, the hydroxyl groups derived from the components (A) and (B) and (C)
An isocyanate group derived from the component is contained, and it is preferable that each component is blended such that the isocyanate group / hydroxyl group equivalent ratio is 0.5 to 2.0. 0.5
If the amount is less than 2.0, the strength of the obtained coating film may be insufficient. If the amount is more than 2.0, the urethane component increases, and the weather resistance and stain resistance decrease. The polyisocyanate compound as the component (C) is preferably mixed with the components (A) and (B) at the time of use (a so-called “two-pack” paint). Further, the resin composition for a coating material of the present invention comprises Despalon KS-860 (Kusumoto Kasei Co., Ltd.) and Despalon #
Pigment dispersant such as 1830 (Kusumoto Kasei Co., Ltd.); Leveling agent such as Desparone L-1980-50 (Kusumoto Kasei Co., Ltd.); 2- (2′-hydroxy-5′-methylphenyl) benzotriazole (Tinuvin) -P, Ci
benzotriazole-based ultraviolet absorbers such as ba Specialty, 2,4-dihydroxybenzophenone (ASL-23, Shonan Chemical), etc .; ADK STAB LA-
77 (Asahi Denka Co., Ltd.), Tinuvin 622LD
Light stabilizers such as hindered amines such as (Ciba Specialty); dibutyltin diacetate (DB
TA), a curing accelerator such as dibutyltin dilaurate (DBTDL), triethylamine and the like; Desparone OX-7
Defoaming agent such as 10 (Kusumoto Kasei Co., Ltd.); Desparone AS
Thickeners such as -415 (Kusumoto Kasei Co., Ltd.); inorganic pigments such as titanium oxide (TiO ₂ ); phthalocyanine blue;
Organic pigments such as quinacridone (Dainippon Ink Co., Ltd.);
Triethyl phosphate (TEP, Daihachi Chemical Co., Ltd.),
Known paint additives such as a plasticizer such as dicyclohexyl phthalate (DCHP, Osaka Organic Chemical Co., Ltd.) can be used. The amount to be used is not particularly limited as long as it does not contradict the purpose of the present invention. For example, the ultraviolet absorber is 0.5 to 2% by weight based on the coating resin composition, and the light stabilizer is 0.5 to 2% by weight based on the resin composition for coating, the curing accelerator is 100 to 100% based on the resin composition for coating.
It can be used in amounts of 1000 ppm. As described above, the coating resin composition of the present invention may be mixed with a pigment such as titanium oxide to form a colored coating, or may be a clear coating without mixing the pigment.
Specifically, the resin composition for a coating of the present invention first comprises:
After mixing the acrylic silicone hybrid polymer of the component (A) and the fluorine-containing polymer of the component (B) (and also mixing a pigment when a coloring paint is used), the polyisocyanate compound of the component (C) as a curing agent Can be obtained by blending In addition, a solvent can be appropriately added to the resin composition for coating of the present invention in order to adjust the viscosity during coating. The resin composition for a coating of the present invention can be applied by a known method such as spraying or a roller. In addition, plasticizers, other resins,
Copolymers can be used in combination as appropriate. The resin composition for coatings of the present invention can exhibit excellent stain resistance for a long period of time when formed into a coating film, and does not cause any problem when repeatedly applied as a coating material. The coating resin composition of the present invention is not particularly limited in its use, but may be, for example, a telephone pole, a street light,
It is suitable as a paint for preventing graffiti on land-based structures such as walls, pedestrian bridges, walls, piers, guardrails, tunnels, gates, vehicles, machinery, ventilation fans, and exhaust devices, and for preventing pollution by dust, dust, waste gas, and the like. The present invention will now be described with reference to Examples and Comparative Examples.
Although described in more detail, the present invention is not limited to these examples. First, each material used in Examples and Comparative Examples will be described. In the following,
All parts and percentages are by weight unless otherwise specified. Component (A): Acrylic silicone hybrid polymer Trade name: Sunfrere LS230 (manufactured by Showa Denko KK) Solid content: 50% Solvent: butyl acetate viscosity: 1,020 mPa · s (20 ° C.) Hydroxyl value: 114 mg KOH / G (in terms of solid content) Silicone content: 10% Acrylic content: 90% Component (B): Fluoropolymer trade name: KD270 (manufactured by Kanto Denka Kogyo KK) Solid content: 30% Solvent: butyl acetate Viscosity: 100 mPa · s (20 ° C.) Hydroxyl value: 115 mg KOH / g (in terms of solid content) Component (C): Polyisocyanate compound Trade name: Coronate HX (Nippon Polyurethane Industry Co., Ltd.)
Solid content: 100% Specific gravity. D ₄ ²⁵ : 1.16 Viscosity: 2,300 mPa · s (20 ° C.) NCO content: 21.3% Acrylic resin: Highly weather-resistant acrylic polyol based on methyl methacrylate Resin trade name: Exerol 290 (manufactured by Asia Industry Co., Ltd.) Solid content: 54% Solvent: Toluene / butyl acetate Viscosity: 8500 mPa · s (25 ° C.) Hydroxyl value: 34 mg KOH / g (solid content conversion) Urethane Resin synthesis method: 5 mol of polypropylene glycol (Mw = 1000) in toluene / butyl acetate solvent, 6 m
ol polyester polyol (Mw = 1250);
10 mol of isophorone diisocyanate was added, and 8
A heating reaction was performed at 0 to 90 ° C. for 10 hours to prepare a urethane resin (Mw = 15000) containing a hydroxyl group at a terminal. Solid content: 50% Solvent: Toluene / butyl acetate Viscosity: 6500 mPa · s (20 ° C.) Hydroxyl value: 7.5 mg KOH / g (solid content conversion) Additive: Silicone compound for preventing blocking (silicone varnish type) Product name: Silicone KP356 (Shin-Etsu Chemical Co., Ltd.)
Active ingredient: 100% Specific gravity: 0.97 Viscosity: 45 mPa · s (25 ° C.) [Examples 1 to 6, Comparative examples 1 to 5] A mixing vessel equipped with a stirrer according to the composition shown in Table 1. Then, a predetermined amount of each resin component is added, and if the resin component does not contain Si, the above additives are added. After stirring for 10 minutes, the polyisocyanate compound as a curing agent is converted into an isocyanate group with respect to a hydroxyl group. It was blended and mixed so as to have a predetermined equivalent ratio to obtain a resin composition for coating. The obtained resin composition for coating was diluted with a solvent, spray-coated on a substrate so as to have a coating thickness of 10 to 20 μm, and allowed to stand at room temperature for 7 days after coating to cure. After the coating film is cured, it is used as a test specimen, and the following (1)-
The evaluation test of (4) was performed. In addition, as a base material, 70
An aluminum plate of × 150 × 2 mm is polished with # 320 abrasive paper, the surface is degreased and washed with ethyl acetate, and then a two-pack type acrylic urethane paint (white) is used as an undercoat, 30 to 40 μm (thickness as a dry film) ). (1) Appearance of Coating Film The coating film surface of the test specimen was visually observed and evaluated according to the following three grades. ：: glossy and uniform surface 程度: low degree of gloss ×: matte without glossiness [0045] (2) Oily ink pen (Red) The ink repelling condition when marked with (red) is visually observed, and the following 3
It was evaluated on a scale. ：: Repelling of the ink is remarkably observed. △: Repelling of the ink is recognized, but the degree of repelling is poor. X: Repelling of the ink is slightly recognized. (3) Sustainability of stain resistance Promotion of weather resistance Testing machine (I-Super UV tester SUV-
Using W151), the test piece was evaluated for oil-based ink contamination after 200 hours and 400 hours. In addition, the oil-based ink stain evaluation method of the test body was the same as the above-mentioned method, and was evaluated in the following three stages. ：: The repelling of the ink is remarkably recognized. Δ: The repelling of the ink is recognized, but the repelling degree is poor. X: The repelling of the ink is slightly recognized. (4) The coating film surface of the graffiti removal test specimen After one day and seven days, the surface of the coated film marked with the oil-based ink pen was rubbed with gauze wetted with water, and visually observed to see if ink could be removed. It was evaluated on a scale. ：: Ink is completely removed. △: Slight ink marks remain. X: Ink marks remain noticeable. (5) Overcoating compatibility In accordance with JIS K 5400 6.8, the paint was overcoated. We checked for any problems. 200 × 10
A steel sheet of 0 × 0.8 mm was used as a base material, and the obtained resin composition for coating was spray-coated on the steel sheet so that the coating film thickness was 30 to 40 μm. After the coating was completed, the coating was left at 20 ° C. for 7 days, and spray coating of the resin composition for coating was performed again. The surface of the coating film obtained by recoating was visually observed and evaluated according to the following three grades. ：: No repelling, cracking, hole, swelling, or peeling of the coating film is observed. Δ: Some repelling, swelling, or cracking of the coating film is observed. X: Repelling of the coating film is remarkably observed. As is evident from the results in Table 1, when the resin composition for a paint of the present invention was used, the stain resistance was superior to that when a conventional paint using an acrylic silicone hybrid polymer was used. Can be obtained over a long period of time (Examples 1 to 6). In particular, by setting the blending amount of the acrylic silicone hybrid polymer and the fluorine-containing polymer in the resin composition to a specific ratio, the durability of the stain resistance can be further improved (Examples 1 to 5). Further, it is shown that the resin composition for a coating material of the present invention does not cause any problem even when it is applied repeatedly, unlike a conventional coating material using an acrylic silicone hybrid polymer. Further, from the results shown in Table 1, the coating resin composition of the present invention is excellent in all of the appearance, stain resistance and graffiti removal property of the coating film, and is very excellent as a coating composition. I can understand that there is.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Masayuki Hirose             2-44-17 Higashi, Kuki-shi, Saitama Shinkoman             Option 303 (72) Inventor Hiroshi Hidori             478, Kashiuchi, Oaza, Washinomiya-cho, Kita-Katsushika-gun, Saitama             Miyadanchi 1-1-102 (72) Inventor Kazuyoshi Nomura             1-11-12 Mutsucho, Kazo City, Saitama Prefecture F term (reference) 4J038 CD091 CD092 CD111 CD112                       CD121 CD122 CD131 CD132                       CG001 CG002 CL001 CL002                       DB05 DG262 DG272 DG282                       DG292 DG302 GA03 GA15                       KA03 NA05

Claims (1)

Claims: (1) (A) a hydroxyl group-containing acrylic polymer having a ladder-type silicone oligomer in a side chain and / or a terminal, (B) (i) a general formula CF ₂ ＣCXY (where X
It is H or F, Y is H, Cl, fluoroolefin 40-90 mole% represented by F or CF is _3),
(Ii) 1 to 30 mol% of a hydroxyl group-containing vinyl monomer,
And (iii) monomers 1 to 30 copolymerizable therewith.
A resin composition for a paint, comprising: a fluorine-containing polymer consisting of mol%; and (C) a polyisocyanate compound.