JP2000017226A - Urethane coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition less problematic in the emission of odor and excellent in curability by incorporating a non-aqueously dispersed particles with a polyisocyanate compound and an acrylic resin having a specified weight- average molecular weight. SOLUTION: There is provided a coating composition containing non- aqueously dispersed particles having a hydroxyl value of 20-100 mgKOH/g, a glass transition temperature of -20 to 60 deg.C, and a mean particle diameter of 100-3,000 nm, a polyisocyanate compound having a mineral spirit dilution ratio of at least 5, and an acrylic resin comprising 5-20 wt.% units of a hydroxyl-containing unsaturated monomer and 90-80 wt.% units of other α,β-unsaturated monomers and having a solubility parameter of 9.2 or below, a glass transition temperature of -20 to 50 deg.C, a hydroxyl value of 20-100 mgKOH/g, and a weight-average molecular weight of 1,000-100,000. The non-aqueously dispersed particles are those of a composite of a stably dispersible acrylic resin having a solubility parameter of 9.2 or below and a glass transition temperature of 50 deg.C or below with a particle-constituting acrylic resin having a solubility parameter of 10.2 or above in a weight ratio of 20/80 to 80/20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a urethane coating composition, and more particularly to a urethane coating composition having excellent dispersion stability of particles, excellent curability at low temperature, weatherability, chemical performance and physical performance. The present invention relates to a urethane coating composition which gives a cured coating film having excellent heat resistance and is suitable for use in interior and exterior of buildings.

[0002]

2. Description of the Related Art Acrylic urethane paints are widely used for various purposes because of their generally excellent coating properties. However, when repainting, old paints (existing paints) are required.
When an undercoat (undercoat) is poor in solvent resistance like a lacquer coat, it is known that lifting is caused by repeatedly applying a urethane-based overcoat. As a technique for improving such a defect, a paint in which an acrylic polyol soluble in a non-polar organic solvent and a polyisocyanate are combined is known. However, in such a coating system, unless the content of the aromatic hydrocarbon solvent in the non-polar organic solvent used is increased to some extent, the polyol does not dissolve in the solvent and is not a very effective method. . In recent years, along with increasing awareness of environmental issues and the revision of the Odor Control Law, complaints about odors caused by organic solvents and unreacted monomers have tended to increase. Has become.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is less affected by odors caused by aromatic hydrocarbon solvents and lifting of old coating films.
The purpose of the present invention is to provide a highly practical urethane coating composition having the same coating film performance as that obtained by using conventional solvents and having excellent curing performance.

[0004]

The present inventors have conducted intensive studies to develop a urethane coating composition having excellent performance as described above. As a result, specific non-aqueous dispersion particles and a low-polar organic solvent Polyisocyanate compound having excellent solubility in, and a urethane composition containing a specific acrylic resin as an essential component, has been found to be suitable for the purpose,
Based on this finding, the present invention has been completed.

That is, the present invention comprises the following items. (1) Solubility comprising (A) (A) 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and 95 to 80% by weight of another α, β-unsaturated monomer unit Parameter 9.
A dispersion stable acrylic resin having a glass transition temperature (Tg) of 50 ° C. or less;
The weight ratio of the acrylic resin having a solubility parameter of 10.2 or more consisting of 5 to 20% by weight of an unsaturated monomer unit and 95 to 80% by weight of another α, β-unsaturated monomer unit is 2
0:80 to 80:20 complex, having a hydroxyl value of 20 to 100 mgKOH / g and a glass transition temperature (Tg) -2.
Non-aqueous dispersion particles having a particle diameter of 0 to 60 ° C and an average particle diameter of 100 to 3,000 nm, (B) when diluted with mineral spirit, have a mineral spirit dilutability [solvent amount when cloudy (g)
/ Test sample amount (g)] is 5 or more, and (C) 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and another α, β-unsaturated monomer Solubility parameter consisting of 95-80% by weight of body unit 9.
2, a glass transition temperature (Tg) of -20 to 50 ° C, a hydroxyl value of 20 to 100 mgKOH / g and a weight average molecular weight of 1,000.
A urethane coating composition comprising from 0 to 100,000 acrylic resin as an essential component. (2) Further, as a component (D), aluminum oxide;
The urethane coating composition according to item (1), comprising a dispersion of at least one inorganic oxide sol selected from silicon oxide, zirconium oxide and antimony oxide. Preferred embodiments of the present invention include the following items. (3) The other α, β-unsaturated monomer unit in the dispersion-stable acrylic resin and the component acrylic resin (A) and the acrylic resin (C) is an α, β-unsaturated carboxylic acid, A compound formed from at least one monomer selected from esters and styrenes.
The urethane coating composition according to (1) or (2). (4) Component (A) and component (C) are in a weight ratio of 30:70.
(1), (2), and 90:10
The urethane coating composition according to the item (3). (5) With respect to 1 mol of the hydroxyl group of the component (A) and the component (C),
The urethane coating composition according to any one of (1), (2), (3) and (4), wherein the component (B) is contained so that the isocyanate group content is 0.2 to 2.0 mol.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the urethane coating composition of the present invention, non-aqueous dispersion particles are used as the component (A). The non-aqueous dispersion particles contain (a) 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and other α, β-unsaturated monomer units.
A solubility parameter consisting of 95 to 80% by weight of unsaturated monomer units of 9.2 or less and a glass transition temperature (Tg) of 50 ° C.
The following dispersion-stable acrylic resin, (ii) 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and other α,
A composite having a solubility parameter of 10.2 or more and an acrylic resin having a solubility parameter of 95 to 80% by weight of β-unsaturated monomer units in a weight ratio of 20:80 to 80:20. The non-aqueous dispersion particles have a hydroxyl value of 20 to 100 mg.
In the range of KOH / g, the glass transition temperature (Tg) is-
20 to 60 ° C., and the average particle diameter is 100 to
It is in the range of 3,000 nm. Here, the solubility parameter (hereinafter, also referred to as Sp value) will be described. This solubility parameter is a numerical value defined by δ = (ΔE / V) ^1/2 (where δ: solubility parameter, ΔE: cohesive energy per mole, V: molar volume), and this value is Approximate compounds indicate good compatibility. The Sp value of the acrylic resin is based on the assumption that additivity is established on a weight basis with respect to the Sp value of each monomer (monomer).
KL Hoy, "Journal of Paint Technology"
of Paint Technology) "No. 42
Vol., No. 541, p. 76 (1970), and the like. For example, the Sp value of each monomer is styrene 9.35, methyl methacrylate 9.23, ethyl acrylate 8.81, n-butyl acrylate 8.25, isobutyl methacrylate 8.5,
2-ethylhexyl acrylate 7.87 and 2-hydroxyethyl acrylate 9.90. For monomers having no literature value, the calculated value obtained by the Hoy method described in the above document (provided that the density is assumed to be 1.0 g / cm ³ ) is used. adopt. In the present invention, Sp of the dispersion-stable acrylic resin of the component (A) constituting the non-aqueous dispersion particles of the component (A) is used.
If the value exceeds 9.2 or the Tg exceeds 50 ° C., the dispersion stability of the non-aqueous dispersion particles decreases. In this dispersion-stable acrylic resin, when the content of the hydroxyl group-containing α, β-unsaturated monomer unit is less than 5% by weight, the effect of improving the desired compatibility in the non-aqueous dispersion particles as the final product is not obtained. If it is insufficient, and if it exceeds 20% by weight, the dispersion stability of the non-aqueous dispersion particles decreases. In consideration of the effect of improving the compatibility of the non-aqueous dispersion particles and the dispersion stability, the content of the preferred hydroxyl group-containing α, β-unsaturated monomer unit is in the range of 10 to 15% by weight.

On the other hand, another component constituting the non-aqueous dispersion particles, the particle component (b) of the acrylic resin S
If the p-value is less than 10.2, the stability of the non-aqueous dispersion particles decreases. Further, in the particle component acrylic resin, the content of the hydroxyl group-containing α, β-unsaturated monomer unit was 5%.
When the amount is less than 20% by weight, the desired effect of improving the compatibility is insufficient, and when the amount exceeds 20% by weight, the dispersion stability of the non-aqueous dispersion particles decreases. In consideration of the effect of improving the compatibility of the non-aqueous dispersion particles and the dispersion stability, the content of the preferred hydroxyl group-containing α, β-unsaturated monomer unit is in the range of 10 to 15% by weight. In the present invention, the non-aqueous dispersion particles of the component (A) have a weight ratio of the dispersion stable acrylic resin of the component (a) to the particle component acrylic resin of the component (b) of 20:
Must be in the range of 80 to 80:20,
If the amount of the component (a) is less than the above range, it is difficult to dissolve in the solvent unless the content of the aromatic hydrocarbon solvent in the nonpolar solvent is increased to a certain extent. Conversely, if the amount of the component (a) is more than the above range, the dispersion stability of the non-aqueous dispersion particles decreases.
Considering the dispersion stability and solubility of the non-aqueous dispersion particles, the preferred ratio of the component (a) to the component (b) is 30: 7.
The range is 0 to 60:40. The non-aqueous dispersion particles have a hydroxyl value in the range of 20 to 100 mgKOH / g, preferably 30 to 80 mgKOH / g. If the hydroxyl value is less than 20 mgKOH / g, a sufficient cross-linking density cannot be obtained, and the coating film performance such as chemical resistance will be reduced, and 100 mgKOH / g.
If it exceeds, the coating film becomes excessively dense and the coating film performance such as impact resistance is deteriorated. Further, Tg is in the range of −20 to 60 ° C., preferably 0 to 30 ° C. If the Tg is lower than -20 ° C, the resulting coating film becomes soft and the hardness of the coating film becomes insufficient, such as insufficient hardness. If the Tg exceeds 60 ° C, the resulting coating film becomes rigid and impact resistance. Of the coating film performance is deteriorated. Further, the average particle size is in the range of 100 to 3,000 nm, preferably 200 to 2,000 nm. If the average particle size is less than 100 nm, the viscosity may be too high, and if it exceeds 3,000 nm, the dispersion stability may decrease.

In the dispersion-stable acrylic resin (A) and the particle acrylic resin (B), the monomer forming the hydroxyl group-containing α, β-unsaturated monomer unit is, for example, 2- (2-) Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate,
Examples thereof include 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, and 4-hydroxybutyl methacrylate. These may be used alone or in combination of two or more. On the other hand, in the dispersion-stable acrylic resin of the component (A) and the particle-component acrylic resin of the component (B), other monomers forming the α, β-unsaturated monomer unit include, for example, acrylic acid and methacrylic acid. acid,
Α, β-unsaturated carboxylic acids such as itaconic acid, mesaconic acid, maleic acid and fumaric acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, cyclohexyl Acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate,
Ethyl methacrylate, n-propyl methacrylate,
Isopropyl methacrylate, sec-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, 2,2,2-trifluoromethyl acrylate, 2,2,2-tri Preferred are α, β-unsaturated carboxylic acid esters such as fluoromethyl methacrylate, and styrenes such as styrene, α-methylstyrene and p-vinyltoluene. In addition, acrylonitrile, methacrylonitrile, or the like can be used. These may be used alone or 2
A combination of more than one species may be used.

The non-aqueous dispersion particles of the component (A) in the present invention may contain, as an organic solvent, aliphatic carbonized substances such as n-hexane, cyclohexane, methylcyclohexanone, ethylcyclohexanone, n-heptane, n-octane and terpene. A hydrogen solvent is used. In addition, for example, LAWS (manufactured by Shell Co., Ltd.), A-Solvent (trade name, Nippon Oil Co., Ltd.) containing about 30% by weight of an aromatic hydrocarbon solvent generally called as "mineral spirit" Co., Ltd.), Shoseki Solvent (trade name, manufactured by Showa Sekiyu KK), etc., and 50% by weight of an aromatic hydrocarbon solvent.
For example, Swazole 310 [trade name,
Maruzen Petrochemical Co., Ltd.], Exxon Naphtha No. 5 [trade name, manufactured by Exxon Corp.] and the like can also be used. Also, if necessary, benzene, toluene, xylene, aromatic hydrocarbon solvents such as ethylbenzene, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, acetate esters such as ethylene glycol monoethyl ether acetate, and Methanol, ethanol,
Alcohols such as propanol, isopropanol, butanol and isobutanol may be added in small amounts. The non-aqueous dispersion particles are obtained by dissolving the dispersion-stable acrylic resin of component (a) in these organic solvents, and then adding a hydroxyl group-containing α, β-unsaturated monomer as a raw material of the particles to the other solution in the obtained solution. Can be produced by copolymerizing the α, β-unsaturated monomer at a temperature of about 60 to 180 ° C. by a usual radical polymerization method. The non-aqueous dispersion particle liquid thus obtained has a nonvolatile content of 30 to 70% by weight.
The degree is advantageous.

In the urethane coating composition of the present invention,
As the polyisocyanate compound of the component (B), a compound having a mineral spirit dilutability of 5 or more when diluted with mineral spirit is used. Here, the mineral spirit dilutability refers to a sample solution obtained by diluting a polyisocyanate compound to a solid content concentration of 75% by weight with Solvesso # 100 [manufactured by Exxon Chemical Co., Ltd., mixed aniline point 13.5 ° C]. It is diluted with mineral spirit until it becomes cloudy, and the value is shown by the value of solvent amount (g) / test sample amount (g) when cloudy. It can be said that the greater the value of the mineral spirit dilutability, the higher the solubility in mineral spirits. Conversely, it can be said that the smaller the value, the lower the solubility in mineral spirits. Here, if the mineral spirit dilutability is less than 5, the solubility in mineral spirit is low, and the polyisocyanate compound is precipitated. As a polyisocyanate compound having a mineral spirit dilutability of 5 or more,
For example, modified aliphatic diisocyanates such as tetramethylene diisocyanate and trimethylhexamethylene diisocyanate, modified aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, isophorone diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate) ), Methylcyclohexane-2,
Various diisocyanate compounds such as modified alicyclic diisocyanate such as 4-diisocyanate, and water, ethylene glycol,
Examples thereof include a terminal isocyanate-containing compound obtained by reacting a low-molecular-weight active hydrogen-containing compound such as propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil, a polymer of the above-mentioned diisocyanate compound, and a burette.

In addition, Duranate TSA-100, Duranate TSE-100, and Duranate TSS-100 [trade names, all of which are trade names of Asahi Kasei Kogyo Co., Ltd.] are excellent in solubility in so-called low-polarity solvents such as aliphatic hydrocarbon solvents.
Co., Ltd.], Vernock DN-990, Vernock DN
-992 and Burnock DN-995 [trade names, all of which are Dainippon Ink and Chemicals, Inc.]. In the present invention, one kind of these polyisocyanate compounds may be used, or two or more kinds may be used in combination. In the urethane coating composition of the present invention,
The component (C) has an Sp value of 9.2 or less consisting of 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and 95 to 80% by weight of another α, β-unsaturated monomer unit. And a glass transition temperature (Tg) of -20 to 50 ° C., and a hydroxyl value of 20 to
100 mgKOH / g and weight average molecular weight 1,000-10
Acrylic resin of 000 is used. When the Sp value of the acrylic resin exceeds 9.2, the solubility in a low-polarity organic solvent decreases. On the other hand, if the hydroxyl value is less than 20 mgKOH / g, a sufficient cross-linking density cannot be obtained, and the coating performance such as chemical resistance will be reduced. If it exceeds 100 mgKOH / g, the coating will be excessively dense and will have an impact resistance and the like. Of the coating film performance is deteriorated.
From these points, the preferred hydroxyl value is 30 to 80 mg KOH.
/ G range. When the Tg is lower than -20 ° C, the formed coating film becomes soft and the coating film performance is deteriorated such that sufficient hardness cannot be obtained. When the Tg exceeds 50 ° C, the formed coating film becomes rigid and impact resistance Etc., the coating film performance deteriorates. Further, if the weight average molecular weight is less than 1,000, a sufficient crosslink density cannot be obtained, and the coating properties such as chemical resistance are reduced, and 100,
When it exceeds 000, the solid content concentration of the coating material decreases, and the amount of the discharged organic solvent increases. The preferred weight average molecular weight is 10,000.
The range is from 00 to 80,000. The weight average molecular weight is a value in terms of styrene measured by a gel permeation chromatography (GPC method).
In this acrylic resin, hydroxyl group-containing α, β
-If the content of the unsaturated monomer unit is out of the above range, a compound having a desired hydroxyl value cannot be obtained. In the acrylic resin of the component (C), the monomer forming the hydroxyl group-containing α, β-unsaturated monomer unit and the other α, β-unsaturated monomer unit may be the aforementioned (A) In the description of the non-aqueous dispersion particles of the components, the same ones as exemplified above can be mentioned.

Regarding the compounding ratio of each component in the urethane coating composition of the present invention, the compounding ratio of the component (A) and the component (C) is usually 30:70 to 90: 1 by weight.
0, preferably in the range of 40:60 to 80:20. Here, when the compounding ratio of the component (A) and the component (C) is less than 30:70, the formed coating film becomes soft, and the coating film performance such as insufficient hardness cannot be obtained. On the other hand, when the ratio exceeds 90:10, the fluidity of the paint at the time of coating deteriorates, and the sharpness deteriorates. The component (B) is
With respect to 1 mol of hydroxyl groups in the components (A) and (C),
The isocyanate group is preferably used in an amount of 0.2 to 2.0 mol, particularly preferably 0.5 to 1.5 mol. If the amount of the isocyanate group is less than 0.2 mol, it is difficult to obtain a desired coating film performance, and if it exceeds 2.0 mol, foaming may occur during the formation of the coating film, and drying properties may be reduced. The urethane coating composition of the present invention is excellent in recoatability, low odor, and low toxicity, but is further provided with aluminum oxide, silicon oxide, and oxidized component (D) for the purpose of imparting stain resistance and stain removal properties. At least one selected from zirconium and antimony oxide
Dispersions of different types of inorganic oxide sols can be included. The dispersion of the inorganic oxide sol is preferably contained as a solid at a ratio of 0.1 to 40.0% by weight based on the solid content of the coating composition. Preferred among these inorganic oxide sols are silicon oxide sols. The dispersion of the silicon oxide sol can be obtained by a method such as adding a silicon tetrahalide to water or adding an acid to an aqueous solution of sodium silicate. As commercial products, for example, as a water-based dispersion, Snowtex-O (trade name, manufactured by Nissan Chemical Industries, Ltd.) and Snowtex-N (trade name, manufactured by Nissan Chemical Industries, Ltd.), and the like, Examples of the organic dispersion include Snowtex MIBK-ST (trade name, manufactured by Nissan Chemical Industries, Ltd.). Here, when the dispersion of the inorganic oxide sol of the component (D) is less than 0.1% by weight based on the solid content of the paint, it is difficult to obtain desired coating film performance, and conversely, 40% by weight.
If the ratio exceeds, the coating film becomes excessively dense and the coating film performance such as impact resistance is deteriorated.

The dispersion of the inorganic oxide sol is preferably a surface-treated with a silane coupling agent, and particularly preferably a dispersion of a silicon oxide sol which is surface-treated with a silane coupling agent. Since the dispersion of the surface-treated inorganic oxide sol can introduce various functional groups into the particle surface, when used in the urethane coating composition of the present invention, an acrylic resin or a polyisocyanate compound is used. It becomes easy to chemically combine with organic components. In the case of such chemical bonding, the crosslinking of the coating film becomes stronger than in the case of not chemically bonding, and the stain resistance, stain removal property, weather resistance, etc. are improved. Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane,
Methyltrimethoxysilane, dimethyldimethoxysilane and the like, preferably methyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ
-Methacryloyloxypropyltrimethoxysilane, particularly preferably methyltrimethoxysilane and dimethyldimethoxysilane. In addition, as a commercial product,
A-162, A-163, and AZ-6122 (all trade names, manufactured by Nippon Unicar Co., Ltd.) and the like. These silane coupling agents can be used alone or in combination of two or more. When the surface treatment is performed with a silane coupling agent, the amount of the silane coupling agent is preferably 1 to 40% by weight, more preferably 5 to 30% by weight, based on the nonvolatile content of the inorganic oxide sol. In the urethane coating composition of the present invention, as long as the object of the present invention is not impaired,
If desired, conventionally known paint additives such as pigments, solvents, additives, and reaction accelerators can be contained. The substrate on which the urethane coating composition of the present invention is applied is not particularly limited, and various substrates can be used, for example, wood, glass, metal, cloth, plastic, foam, and elastic body. , Paper, ceramic, concrete, gypsum board, and other organic materials and inorganic materials. These substrates may be those which have been subjected to a surface treatment in advance, or those having a coating film formed on the surface in advance. Examples of the coated articles obtained by applying the urethane coating composition of the present invention include buildings, structures, wood products, metal products, plastic products, rubber products, processed paper, ceramic products, glass products, and the like. .

[0014]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the coating film performance in Examples and Comparative Examples was determined as follows. (1) Drying property Immediately after coating, the test plate was allowed to stand in a constant temperature / humidity room at a temperature of 20 ° C. and a humidity of 75% RH, and eight gauze pieces were superimposed on the surface of the coating film after 8 hours and 16 hours after the standing. Put things on it and put 200 on it
g of weight was placed for 1 minute, and the gauze trace immediately after was evaluated by visual observation according to the following criteria. ：: no trace of gauze at all △: slight trace of gauze ×: marked trace of gauze (2) Pencil hardness The test plate was left in a thermo-hygrostat at a temperature of 20 ° C and a humidity of 75% RH for 7 days. Thereafter, a pencil scratch test was performed at the same temperature to examine the hardness of the pencil that damages the coating film. (3) Adhesion An adhesion test was performed in accordance with JIS K-5400 (1990) 8.5. With a perfect score of 10,
The higher the score, the better the adhesion. (4) Moisture resistance After exposing the test specimen at a relative humidity of 95% or more under the condition of 40 ± 1 ° C. for 240 hours, the surface state of the test specimen 2 hours after removal was visually observed and evaluated according to the following criteria. did. ：: no change in gloss and surface state as compared to the original test specimen △: slight change in gloss and slight blistering compared to the original test specimen ×: gloss as compared to the original test specimen (5) Acid resistance and alkali resistance 0.2N sulfuric acid aqueous solution or 0.2N sodium hydroxide aqueous solution was spotted on 0.2 ml, and the coating film after 24 hours at 20 ° C. Surface abnormalities were visually determined. ：: No abnormality ×: Abnormal (6) Solvent resistance A rubbing tester was used. Rubbing was performed 100 times back and forth by applying a load of 2 kg with xylene, and the surface of the coating film was visually determined. ：: No abnormality ×: Abnormal (7) Impact resistance In accordance with JIS K-5400 (1990) 8.3.2, using a DuPont impact tester, hit center 1/2 inch, load 500
The test was conducted under the condition of g, and the result was indicated by the maximum height (cm) at which no damage was caused to the coating film. (8) Accelerated weather resistance Sunshine carbon arc lamp type (JIS K-5400
(1990) 9.8.1), the 60 degree gloss value (JI) of the coating film after exposure for 1,000 hours or 3,000 hours.
SK-5400 (1990) 7.6 specular gloss) was measured, and the abnormality of the coating film was visually determined, or compared with the gloss value before exposure. ：: No change in the coating film, and the gloss retention exceeds 80%. Δ: The coating film has no gloss and the gloss retention is 40 to 80%. X: Cracks and the like occur in the coating film, and the gloss retention is 40. <9% (9) Visibility It was evaluated by visual observation according to the following criteria. ○: When fluorescent light is projected on the coating film, the fluorescent light is clearly seen. △: When the fluorescent light is projected on the coating film, the periphery (outline) of the fluorescent light is slightly blurred. ×: When the fluorescent light is projected on the coating film, the fluorescent light is emitted. (10) Odor The result of a sensory test by 5 persons. ○: No odor △: Slight odor ×: Odor (11) Recoating property The recoating property for the old coating film was determined by applying each paint on the old coating film (existing coating film) after one year of natural exposure. The state of the coating film after each coating was visually determined. ：: No abnormality △: Some degree of lifting phenomenon is observed X: Remarkable lifting phenomenon is observed (12) Oil resistance marker stainability A line is drawn on the coating film of the test piece with an oil marker, and 5 points at 80 ° C.
After heating for a period of time, the line was wiped off with a flannel impregnated with xylene, and the change in the surface state was visually observed, and the staining of the oily marker was evaluated according to the following criteria. ：: The line of the oily marker on the test piece was completely wiped off and no trace was left. △: The trace of the oily marker line on the test piece was slightly left. ×: The trace of the oily marker line on the test piece was clearly left.

Production Example 1 Production of non-aqueous dispersion particle A-1 solution of component (A) [1] Production of dispersion-stable acrylic resin A- (a) -1 solution Thermometer, reflux condenser, stirrer, dropping In a four-necked flask equipped with a funnel, 180.0 g of mineral spirit and 190.0 g of "Solvesso 100" were charged, and heated at 140 ° C. with stirring. Next, at a temperature of 140 ° C., a mixture having the following composition was dropped at a constant rate over 2 hours, and was further maintained for 2 hours.
A dispersion-stable acrylic resin A- (a) -1 solution having a Tg of 10 ° C. and an Sp value of 8.95 was obtained. Acrylic acid 12.0 g 2-Hydroxyethyl methacrylate 315.0 g Styrene 900.0 g Isobutyl methacrylate 150.0 g 2-Ethylhexyl methacrylate 1,260.0 g 2-Ethylhexyl acrylate 363.0 g t-butylperoxy-2-ethylhexoate 10 2.0 g [2] Production of Non-Aqueous Dispersion Particle A-1 Liquid In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, the dispersion stabilizer acrylic resin A of [1] was added.
-(I) -1 solution (500.0 g) and mineral spirit (192.0 g) were charged and heated to 95 ° C. while stirring. Next, a mixture having the following composition was dropped at a constant rate over a period of 2 hours at a temperature of 95 ° C., and was further maintained for 2 hours to obtain a nonvolatile content of 60% by weight.
Non-aqueous dispersion particles A-1 having a particle component acrylic resin weight ratio of 50/50, a nonvolatile content of 60% by weight, 25%
A milky-white liquid (non-aqueous dispersion particle A-1 liquid) having a viscosity of 0.3 poise at ° C was obtained. Acrylic acid 1.2 g 2-Hydroxyethyl methacrylate 34.8 g Methyl methacrylate 141.0 g Butyl acrylate 78.0 g Styrene 45.0 g t-Butylperoxy-2-ethylhexoate 8.0 g Production Example 2 Non-component (A) Production of aqueous dispersion particles A-2 liquid [1] Production of dispersion stable acrylic resin A- (a) -2 solution Mineral spirit was placed in a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel. 1.80.0 g and 190.0 g of "Solvesso 100" were charged and heated under stirring to keep 140 ° C. Next, a mixture having the following composition was added dropwise at a constant rate over 2 hours at a temperature of 140 ° C., and the mixture was maintained for 2 hours.
Thus, a dispersion-stable acrylic resin A- (a) -2 solution having a g of 10 ° C. and an Sp value of 8.15 was obtained. Acrylic acid 12.0 g 2-hydroxyethyl methacrylate 315.0 g Styrene 750.0 g Isobutyl methacrylate 258.0 g 2-Ethylhexyl methacrylate 795.0 g 2-Ethylhexyl acrylate 420.0 g Butyl methacrylate 450.0 g T-butylperoxy-2-ethyl 10.0 g of xoate [2] Production of non-aqueous dispersion particle A-2 liquid In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, the dispersion stabilizer solution A of the above [1] was placed. -(A)
-2 solution 500.0 g and mineral spirit 192.0
g was heated under agitation and maintained at 95 ° C. Next, a mixture having the following composition was added dropwise at a constant rate over a period of 2 hours at a temperature of 95 ° C., and the mixture was kept for 2 hours to obtain a milky white having a nonvolatile content of 60% by weight and a viscosity at 25 ° C. of 0.3 poise. A non-aqueous dispersion particle A-2 liquid was obtained. Acrylic acid 1.2 g 2-Hydroxyethyl methacrylate 34.8 g Methyl methacrylate 157.0 g Butyl acrylate 77.7 g Styrene 30.0 g t-butylperoxy-2-ethylhexoate 8.0 g

Production Example 3 Production of non-aqueous dispersion particles A-3 of component (A) [1] Production of non-aqueous dispersion particles A-3 A thermometer, a reflux condenser, a stirrer, and a dropping funnel are provided. In a four-necked flask, 500.0 g of the dispersion-stable acrylic resin A- (a) -1 solution obtained in Production Example 1 [1] and 192.0 g of mineral spirit were charged, and heated under stirring to obtain 9
It was kept at 5 ° C. Next, at a temperature of 95 ° C., Production Example 2 [2]
The same liquid as the monomer mixture used in the above was dropped at a constant rate over 2 hours, and the mixture was kept for 2 hours to obtain a milky white non-aqueous dispersion having a nonvolatile content of 60% by weight and a viscosity at 25 ° C of 0.3 poise. A liquid body A-3 was obtained. Production Example 4 Production of Liquid A-4 of Non-Aqueous Dispersion Particles of Component (A) [1] Production of Liquid A-4 of Non-Aqueous Dispersion Particles Four equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel. In a neck flask, 500.0 g of the dispersion-stable acrylic resin A- (a) -1 solution obtained in Production Example 1 [1] and 192.0 g of mineral spirit were charged, and heated under stirring to obtain 9%.
It was kept at 5 ° C. Next, a mixture having the following composition is dropped at a constant rate over a period of 2 hours at a temperature of 95 ° C., and is further maintained for 2 hours, so that the nonvolatile content is 60% by weight and the viscosity at 25 ° C. is 0.3 poise. A milky white non-aqueous dispersion particle A-4 liquid was obtained. Acrylic acid 1.2 g 2-Hydroxyethyl methacrylate 34.8 g Methyl methacrylate 216.0 g Butyl acrylate 48.0 g t-Butylperoxy-2-ethylhexoate 8.0 g Production Example 5 Non-aqueous dispersion particles of component (A) Production of Liquid A-5 [1] Production of Dispersion Stabilizer Solution A- (a) -3 Solution In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, 1,800 mineral spirits were added. 0 g and 190.0 g of "Solvesso 100" were charged, and heated at 140 ° C. under stirring. Next, at a temperature of 140 ° C., a mixture having the following composition was dropped at a constant rate over 2 hours, and was further maintained for 2 hours.
A dispersion stabilizer solution A- (a) -3 having a Tg of 10 ° C. and an Sp value of 9.18 was obtained. Acrylic acid 12.0 g 2-hydroxyethyl methacrylate 315.0 g Styrene 600.0 g Isobutyl methacrylate 438.0 g 2-Ethylhexyl methacrylate 780.0 g 2-Ethylhexyl acrylate 405.0 g Butyl methacrylate 450.0 g T-butyl peroxy-2-ethyl 10.0 g of xoate [2] Production of non-aqueous dispersion particle A-5 liquid In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, the dispersion-stable acrylic resin A of the above [1] was placed. −
(I) -30.0 g of the solution-3 and 192.0 g of mineral spirits were charged and heated at 95 ° C. with stirring. Next, a mixture having the following composition was dropped at a constant speed over a period of 2 hours at a temperature of 95 ° C., and was further maintained for 2 hours to obtain a nonvolatile matter of 60% by weight and a viscosity of 0.3 at 25 ° C.
A milky white non-aqueous dispersion particle A-5 liquid as a poise was obtained. Acrylic acid 1.2 g 2-Hydroxyethyl methacrylate 34.8 g Methyl methacrylate 166.0 g Butyl acrylate 78.0 g Styrene 20.0 g t-Butylperoxy-2-ethylhexoate 8.0 g Dispersion of Production Examples 1 to 5 Table 1 shows the blending of the stable acrylic resin and the particle component acrylic resin and their characteristic values.

[0017]

[Table 1]

[Note] AA: acrylic acid HEMA: 2-hydroxyethyl methacrylate St: styrene IBMA: isobutyl methacrylate EHMA: 2-ethylhexyl methacrylate EHA: 2-ethylhexyl acrylate BMA: butyl methacrylate MMA: methyl methacrylate BA: butyl acrylate

Production Examples 6 to 8 Acrylic resins C-1, C-2, and C-
Preparation of 3 Solutions Initially charged solvent (xylene) was charged into a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, heated under stirring, and maintained at 140 ° C. Next, at a temperature of 140 ° C., a mixture of the monomer and the polymerization initiator (dropping component) having the composition shown in Table 2 was dropped at a constant rate from the dropping funnel over 2 hours. After completion of the dropwise addition, the temperature was maintained at 100 ° C. for 1 hour, a polymerization initiator solution (additional catalyst) having the composition shown in Table 2 was added, and the reaction was terminated when the temperature was further maintained at 100 ° C. for 2 hours. Compound C-1, C-2, and C-3 solutions having the properties shown in Table 2 were obtained.

[0020]

[Table 2]

Examples 1 to 6 (1) Production of paint Of the components shown in Table 3, component (C) and titanium dioxide as another component were mixed and charged into a sand mill. The components (A) and (B) shown in Table 2 were added to a dispersion obtained by dispersing the particles until the particle size became 10 μm or less, and mixed to obtain a raw paint. Next, this raw paint was applied with a mineral spirit to give a coating viscosity (Ford Cup No. 4,
At 20 ° C. for 20 seconds) to produce a coating. (2) Preparation of test pieces and evaluation of coating film performance Bond coat steel plate was air-sprayed with an undercoating paint Epicomaline Primer Red Rust (trade name, manufactured by Nippon Oil & Fats Co., Ltd.) to a dry film thickness of 40 μm, and the temperature was 20 ° C. 75% humidity
It was left in a constant temperature and humidity room of RH for 24 hours. Next, the middle coat paint epicomalin middle coat white [trade name, manufactured by NOF Corporation]
Is sprayed to a dry film thickness of 40 μm in a constant temperature and humidity chamber at a temperature of 20 ° C. and a humidity of 75% RH.
The specimen left for a time was used as a test piece. Furthermore, the diluted paint prepared in (1) was applied by air spraying so as to have a dry film thickness of 30 μm, and was left in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 75% RH for 168 hours (the test piece for the drying test was (Leave for 8 hours and 16 hours) to prepare a test piece and evaluate the coating film performance. Table 3 shows the paint formulations of Examples 1 to 6. The coating film performance is shown in Table 4-1. In each case, a uniform and glossy coating film was obtained, and excellent drying property, adhesion,
It exhibited moisture resistance, impact resistance, acid / alkali resistance, and accelerated weather resistance.

[0022]

[Table 3]

[0023]

[Table 4]

[Note] 1) Trade name, made by Asahi Kasei Kogyo Co., Ltd. 2) Trade name, made by Dainippon Ink & Chemicals, Inc. 3) Titanium dioxide JR-602: trade name, Teikoku Chemical Co., Ltd.
4) Inorganic oxide sol Snowtex MIBK-ST:
Product name, manufactured by Nissan Chemical Industry Co., Ltd.

[0025]

[Table 5]

[0026]

[Table 6]

Examples 7 to 10 (1) Production of paint Of the components shown in Table 3, component (C) and titanium dioxide as another component were mixed and charged in a sand mill. To the dispersion obtained by dispersing the particles until the particle size became 10 μm or less, the components (A) and (B) shown in Table 3 were added and mixed with the component (D) to obtain a raw paint. Next, the raw paint was diluted with a mineral spirit to a coating viscosity (Ford Cup No. 4, 20 ° C. for 20 seconds) to produce a paint. (2) Preparation of test pieces and evaluation of coating film performance Test pieces were prepared in the same manner as in Examples 1 to 6. -2 shows the paint performance. In each case, a uniform and glossy coating film was obtained, and exhibited excellent drying properties, adhesion properties, moisture resistance, impact resistance, acid / alkali resistance, accelerated weather resistance, and low contamination. Comparative Production Example 1 (1) Production of Dispersion-Stable Acrylic Resin A- (A) -4 Solution In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, 1.80.0 g of mineral spirits was added. And 190.0 g of "Solvesso 100", and heated at 140 ° C. while stirring. Next, a mixture having the following composition was added dropwise at a constant rate over 2 hours at a temperature of 140 ° C., and the mixture was further kept for 2 hours.
Thus, a dispersion-stable acrylic resin A- (a) -4 solution having a g of 10 ° C. and an Sp value of 8.95 was obtained. Acrylic acid 12.0 g Styrene 900.0 g Isobutyl methacrylate 195.0 g 2-Ethylhexyl methacrylate 411.0 g 2-Ethylhexyl acrylate 486.0 g Butyl methacrylate 96.0 g T-butyl peroxy-2-ethylhexoate 10.0 g (2) Production of Non-Aqueous Dispersion Particle A-6 Solution The dispersion stabilizer solution A obtained in (1) above was placed in a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel.
500.0 g of-(a) -6 solution and 192.0 g of mineral spirit were charged, and the mixture was heated with stirring and maintained at 95 ° C. Next, a mixture having the following composition was added dropwise at a constant rate over a period of 2 hours at a temperature of 95 ° C., and the mixture was kept for 2 hours to obtain a milky white having a nonvolatile content of 60% by weight and a viscosity at 25 ° C. of 0.3 poise. A non-aqueous dispersion particle A-6 liquid was obtained. Methyl methacrylate 37.5 g Butyl acrylate 165.0 g Ethyl acrylate 54.0 g Acrylonitrile 43.5 g T-butyl peroxy-2-ethylhexoate 8.0 g Comparative production example 2 (1) Non-aqueous dispersion particles A-7 Production In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, 500.0 g of the dispersion stabilizer solution A- (a) -1 solution obtained in Production Example 1 [1], and minerals 192.0 g of spirit was charged and heated under stirring to 95 ° C.
Held. Next, a mixture having the following composition was dropped at a constant addition rate over 2 hours at a temperature of 95 ° C., and the mixture was kept for 2 hours to obtain a milky white having a non-volatile content of 60% by weight and a viscosity at 25 ° C. of 0.3 poise. Non-aqueous dispersion particles A
-7 liquid was obtained. Acrylic acid 1.2 g 2-hydroxyethyl methacrylate 83.7 g Methyl methacrylate 150.0 g Butyl acrylate 65.1 g T-butyl peroxy-2-ethylhexoate 8.0 g

[0028]

[Table 7]

[Note] EA: Ethyl acrylate AN: Acrylonitrile Other symbols are the same as the footnotes in Table 1.

Comparative Examples 1 to 3 (1) Production of paint Of the components shown in Table 6, component (C) and other components, titanium dioxide, were mixed and charged in a sand mill. The component (B) and the component (A) were added to a dispersion obtained by dispersing the particles until the particle size became 10 μm or less, and mixed to obtain a raw paint. Next, the raw paint was diluted with a mineral spirit to a coating viscosity (Ford Cup No. 4, 20 ° C. for 20 seconds) to produce a paint. (2) Preparation of test pieces and examination of coating film performance A primer coating epicomalin primer red rust (trade name, manufactured by Nippon Oil & Fats Co., Ltd.) was applied to a bond steel plate by air spray coating to a dry film thickness of 40 μm, and the temperature was 20 ° C. 75% humidity
It was left in a constant temperature and humidity room of RH for 24 hours. Next, the middle coat paint epicomalin middle coat white [trade name, manufactured by NOF Corporation]
Is sprayed to a dry film thickness of 40 μm in a constant temperature and humidity chamber at a temperature of 20 ° C. and a humidity of 75% RH.
The specimen left for a time was used as a test piece. Furthermore, the diluted paint prepared in (1) was applied by air spraying so as to have a dry film thickness of 30 μm, and was left in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 75% RH for 168 hours (the test piece for the drying test was 8 hours and 16 hours) to prepare test pieces. Table 6 shows the paint formulations of Comparative Examples 1 to 3. The coating film performance is shown in Table 7. In each case, a uniform and glossy coating film was obtained, but satisfactory coating film performance could not be obtained.

[0031]

[Table 8]

[Note] 1) Trade name, manufactured by Asahi Chemical Industry Co., Ltd. 2) Trade name, manufactured by Dainippon Ink and Chemicals, Inc. 3) Titanium dioxide JR-602: trade name, Teikoku Chemical Co., Ltd.
Made, rutile type titanium dioxide

[0033]

[Table 9]

[0034]

The urethane coating composition of the present invention is excellent in low-temperature curability, gives a cured product excellent in weather resistance, chemical performance and physical performance, and is excellent in particle dispersion stability. Further, the non-aqueous polymer dispersion used in the present invention is compatible with a resin having a wide range of polarities, so that the degree of freedom in paint design is increased, and it can be applied to a wide variety of fields. Especially when used as a top coat, it has excellent finish appearance and low toxicity, low odor, recoatability, stain resistance, and stain removal properties by using an aliphatic hydrocarbon solvent. It is extremely useful in the field of building exterior and interior.

Continued on the front page F-term (reference) 4J034 BA07 CA04 CA05 CB03 CB04 CB07 CC03 CE01 DA01 DB03 DB07 DD07 DP03 DP04 DP13 DP18 EA12 HA01 HA02 HA07 HB08 HC03 HC12 HC17 HC22 HC46 HC52 HC61 HC64 HC67 HC71 HC73 JA03 JA14 JA19 JA30 MA03 MA04 Q QB03 QB19 QC05 RA07 4J038 DG191 DG261 DG271 DG281 DG321 GA03 HA216 HA446 KA06 MA13 MA14 MA16 NA23 NA25 NA27

Claims (2)

[Claims] (1) (A) (a) hydroxyl group-containing α, β-
A solubility parameter consisting of 5 to 20% by weight of unsaturated monomer units and 95 to 80% by weight of other α, β-unsaturated monomer units of 9.2 or less and a glass transition temperature (Tg) of 50 ° C. or less; A dispersion-stable acrylic resin, (b) 5 to 20% by weight of a hydroxyl group-containing α, β-unsaturated monomer unit and another α, β-
A composite having a solubility parameter of 10.2 or more and an acrylic resin having a solubility parameter of 20 to 80 to 20:20 and a hydroxyl value of 20 to 100 mgKOH / g, glass transition temperature (Tg)
-20 to 60 ° C and an average particle size of 100 to 3,000 nm
Non-aqueous dispersion particles of (B), a polyisocyanate compound having a mineral spirit dilutability [amount of solvent (g) in white turbidity / amount of test sample (g)] of 5 or more when diluted with mineral spirit, and (C) ) Hydroxy group-containing α, β
A solubility parameter consisting of 5 to 20% by weight of unsaturated monomer units and 95 to 80% by weight of other α, β-unsaturated monomer units, 9.2 or less, glass transition temperature (Tg) -20 to 50
A urethane coating composition comprising, as essential components, an acrylic resin having a hydroxyl group value of 20 to 100 mgKOH / g and a weight average molecular weight of 1,000 to 100,000. 2. The urethane according to claim 1, further comprising as component (D) a dispersion of at least one inorganic oxide sol selected from aluminum oxide, silicon oxide, zirconium oxide and antimony oxide. Paint composition.