JPH1045867A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition having high contamination resistance without use of any amine, along with having high hardness, high chemical resistance and the storage stability of the coating materials therefrom. SOLUTION: This thermosetting resin composition essentially comprises (A) a film-forming polyol resin 5-300 in hydroxyl number and 500-20,000 in number-average molecular weight, (B) a blocked isocyanate curing agent and/or amino resin reactive to the resin A, and (C) an organosilica sol 10-100nm in particle size and >=15.0mL in hydrophobicity degree in terms of hexane tolerance value. Optionally, the component B is composed of a constituent with a solubility parameter lower than that of the component A by >=0.5 and the 2nd constituent with a solubility parameter higher than, equal to, or <0.5 lower than that of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thermosetting resin composition, and in particular, to the formation of a film of a thermosetting paint having excellent stain resistance, chemical resistance (acid resistance and alkali resistance), hardness and storage stability. The present invention relates to a thermosetting resin composition used as a component.

[0002]

2. Description of the Related Art Outdoor paints used for painting exterior building materials, road materials, vehicles including automobiles, aircrafts, etc., are not only contaminated with oil-based quick-drying inks, foods, tobacco, etc., but also with dust and dust in the atmosphere. Contamination resistance to streak-like contamination (rain dripping contamination) due to dripping containing the water is required. For outdoor paints, it is further required to impart acid resistance in order to suppress coating film deterioration, contamination, and spots due to acid rain, acidic exhaust gas, and the like. In addition, in the case of exterior building materials, especially for wall coating construction materials, to prevent film deterioration and contamination due to alkali flowing out of mortar and concrete used for walls, and in the case of steel products, the alkali generated at the cathode may cause peeling of the coating film. Since it is known, alkali resistance is also required.

[0003] Indoor painted products used for painting home appliances, kitchen products, interior building materials, furniture and the like are also required to be resistant to general pollution by quick-drying oil-based inks, foods, tobacco, and the like. Alkali resistance is required to withstand washing with an alkaline cleaning agent and peeling of a coating film generated at a cathode portion under corrosive conditions.

[0004] Further, in order to prevent scratches caused by brush cleaning and the like for outdoor use and indoor use, and to prevent scratches due to dust in the air (hard dust such as sand, earth and sand, dust, etc.) in outdoor painted products. High hardness (pencil hardness 4H or more)
It is desirable to have

However, it is difficult to simultaneously satisfy the hardness of the coating film and other required performance. That is, simultaneously satisfying these individual performances or some of them can be achieved by devising a resin component, but simultaneously satisfying all of them cannot be achieved by improving the resin component. For example, with respect to general contamination by a quick-drying oil-based ink or the like, contamination resistance can be imparted by incorporating a release component such as silicone or fluororesin into the resin component. And other performances are not satisfied.

Recently, attention has been focused on outdoor paints using a system in which a polymer having an alkoxysilyl group (a part of which may be hydrolyzed to a silanol group) is crosslinked and cured with tetraalkoxysilane or a condensate thereof. ing. JP-A-6-145453, JP-A-7-15010
2, JP-A-7-68217, WO94 / 06879. These paints use the condensation reaction between silanol groups generated by alkoxysilyl groups or the hydroxyl groups in the resin to cure the coating film itself, and simultaneously convert the alkoxysilyl groups remaining on the coating film surface with rainwater. Is hydrolyzed to hydrophilic silanol groups by contact or acid treatment to enhance the wettability of the coating film, and contaminants are easily removed by rainfall or washing with water.

[0007] However, these paints are formed by -Si-O-Si- or -Si- formed by a crosslinking reaction with a resin.
That the OC—C— bond is easily cleaved by acid or alkali, and that the hydrolysis of the alkoxysilyl group remaining in the coating film /
Defects such as easy storage cracking and pot life were found, as can be seen from the fact that condensation easily causes cracks in the coating film and that their curing principle is basically the same as that of moisture-curable silicone rubber. Can be

[0008] WO 95/17349 discloses a suspension of reactive ultrafine silica having a radius of inertia of 10 ° or less, which is a partially hydrolyzed condensate of tetramethoxysilane. This suspension is self-curing, and forms a very hard (pencil hardness of 9H or more) coating film when applied to an object and baked. Since this film is essentially made of amorphous silica, it has not only excellent hardness but also other properties such as heat resistance as compared with a cured film of an ordinary organic coating material. Poor flexibility. Therefore, it is not suitable for a coating material such as a pre-coated metal (PCM) which is subjected to mechanical deformation such as bending.

For this reason, there is a demand for thermosetting resin compositions and paints which are excellent in stain resistance, chemical resistance, etc. and also form a coating film having high hardness (pencil hardness of 4H or more) at the same time. Exists.

[0010] The present inventors have already prepared a polyol resin,
The solubility parameter of the polyol resin (hereinafter referred to as “S
P ". A) a curing agent having an SP value less than 0.5 (primarily a melamine resin) and a second curing agent having an SP value greater than, equal to or less than 0.5 of the polyol resin. It is mainly a block isocyanate compound), an organosilica sol, an amine having a low boiling point (40 ° C. or higher), and a catalyst.
8-78406).

According to the invention, stain resistance, chemical resistance and high hardness are achieved, but the use of a large amount of amine promotes the hydrolysis and condensation of silanol groups or alkoxysilyl groups on the surface of the siligasol, and promotes the coating composition. In some cases, paint stability was not always sufficient.

When the amine is removed in order to enhance the coating stability, the stain resistance is reduced, and a coating composition having the desired properties cannot be obtained.

Further, the present inventors have already invented a thermosetting resin composition in which a partially hydrolyzed condensate of tetramethoxysilane is combined with a binder mainly composed of a polyol resin and a block isocyanate compound. (Japanese Patent Application No. 8-90132). In the present invention, by sharing the essentially inorganic silica-containing component and the essentially organic resin component in the coating film, it is possible to obtain P
A curable resin composition suitable for CM has been proposed.

In the present invention, the low alkali resistance caused by silanol groups and alkoxysilyl groups contained in the partially hydrolyzed condensate of tetramethoxysilane is improved by the formation of urethane bonds caused by the block isocyanate curing agent. succeeded in. Furthermore, by using ultrafine particulate reactive silica, a sea / island structure or a matrix structure was formed, thereby achieving both good workability and high hardness.

However, since the silica component has high reactivity, the storage stability and the gloss of the coating film when forming a coating material are not always sufficient.

[0016]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems by providing high stain resistance without using amine, high hardness, high chemical resistance, and storage of paint. Provided is a curable resin composition having stability. That is, the present invention dramatically improves alkali resistance and storage stability while having high hardness and high stain resistance.

[0017]

SUMMARY OF THE INVENTION The present invention provides an organosilica sol or a silica sol hydrophobized by subjecting an organosilica sol to a silane coupling treatment using an organic solvent as a medium. Combine with a binder using resin. That is, the present invention relates to (A) a hydroxyl number of 5
A film-forming polyol resin having a number average molecular weight of 500 to 20,000, (B) a blocked isocyanate curing agent and / or an amino resin that reacts with the resin (A), and (C) a particle size of the resin. 10 to 100 nm, and its hydrophobicity is expressed as a hexane tolerance value of 1
The thermosetting resin composition contains, as an essential component, an organosilica sol of 5.0 ml or more.

The present invention also relates to a thermosetting paint containing the above-mentioned thermosetting resin composition as a film-forming component, a method of coating an object using the paint, and a coated object.

Description of Preferred Embodiments (A) Component Polyol resins which form cured coatings by urethane crosslinking are well known. Typical examples of these are (modified) acrylic polyol resins, (modified) polyester polyol resins, (modified) fluorinated polyol resins, and (modified) silicone polyol resins.

The hydroxyl value of the polyol resin is 5 to 3
00, the number average molecular weight is 500-20,000. Preferably, the hydroxyl number is between 10 and 200, more preferably between 30 and 100. If the hydroxyl value is 5 or less, the amount of the curable reactive group is too small, and the curability decreases. If the amount is too large, a hydrophilic group remains in the cured film, and the water resistance, acid resistance, and alkali resistance of the coating film decrease. If the molecular weight is too small, the strength of the film will be reduced, and if it is too large, the viscosity of the coating will be too high and the coatability will be reduced.

Hydroxyl number (OH
V) is 10-100. If the OHV is large, the curability is good, but the workability is reduced. If OHV is small, workability is good but curability is reduced. Naturally, other physical properties must be within the range to be provided as a film-forming resin for PCM paints, for example, an acid value of 0 to 50, a glass transition temperature (Tg) of -20 ° C to 60 ° C, and a number average. Molecular weight
It is desirable to be within the range of 1800 to 20,000.

Two types of curing agents [component (D) and component (E)] having different (ΔSP) differences between the solubility parameter (SP) value of the polyol resin (A) and the SP value of the curing agent are used in combination. Thereby, the stain resistance can be further improved (details will be described later). Therefore, the SP value of the polyol resin is important for obtaining a desired ΔSP.

Further, the SP value of the polyol resin is important for ensuring the compatibility between the polyol resin and the organosilica sol of the component (C).

From the viewpoint of the above-mentioned stain resistance and compatibility,
The SP value of the polyol resin (A) is usually from 9.5 to 1
2. Here, when two or more resins are blended and used as the component (A), it means the weighted average of the SP values of the constituent resins.

The SP value of the polyol resin for ensuring compatibility between the methanol silica sol other than the organosilica sol defined in the present application and the polyol resin is 10.
5-12.

Here, the SP value (solubility parameter) is a measure of solubility and is measured as follows. References SUH, CLARKE [J. P. S. A
Measurement temperature: 20 ° C. Sample: 0.5 g of resin is weighed into a 100 ml beaker, 10 ml of a good solvent is added by using a whole pipette, and dissolved by a magnetic stirrer. ・ Measurement of turbidity point Using a 50 ml burette, a poor solvent is dropped, and the point at which turbidity occurs is defined as the dropping amount.・ Calculation The SP value δ of the resin is given by the following equation.

Δ = (V _ml ^1/2 δ _ml + V _mh ^1/2 δ _mh ) /
^{_{(V ml 1/2 + V mh 1/2}} ) V m = V 1 V 2 / (φ 1 V 2 + φ 2 V 1) δ m = φ 1 δ 1 + φ 2 δ 2 V i: solvent molecular volume (ml / Mol) φ _i : volume fraction of each solvent at the cloud point δ _i : SP value of the solvent ml: low SP poor solvent mixed system mh: high SP poor solvent mixed system

Depending on the purpose of the coating, these resins may be modified in other segments. For example, acrylic polyol and polyester polyol resins may be modified with other types of segments commonly used in coatings such as silicone. Also, functional groups other than hydroxyl groups,
For example, it may be modified to have a carboxyl group, an alkoxysilyl group or the like. This type of modification may be carried out as appropriate according to the requirements of the target coating film. In the case of modification so as to have an alkoxysilyl group, the modification is preferably performed so that the alkoxysilyl equivalent of the component (A) becomes 650 or more.

The other physical properties are designed so as to fall within the range to be provided as a film-forming resin for paint. For example, the glass transition temperature (Tg) is from -20C to 60C. When the Tg is low, the formed coating film becomes soft. On the other hand, if the Tg is too high, the coating film tends to be non-uniform, and the formed coating film is too hard, which tends to cause cracks. The acid value is less than 30, and when the acid value is higher than this, when the alkoxysilyl group remains in the component (C) to be combined, it serves as a catalyst for the hydrolysis and condensation reaction, and the stability of the paint ( (Moisture curability under open air, storage stability).

Hereinafter, each polyol resin will be described in detail.

(Modified) Acrylic Polyol Resin The acrylic polyol resin is obtained by copolymerizing a hydroxyl group-containing acrylic monomer and another ethylenically unsaturated monomer by a conventional method.

Examples of hydroxyl group-containing acrylic monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate,
And hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate and 4-hydroxybutyl methacrylate.

Further, various monomers can be used in order to adjust the physical properties of the coating film so as to match the intended coating material. For example, in order to impart flexibility to a coating film and enhance processability as a PCM, a monomer containing a soft segment,
For example, an ε-caprolactone-modified acrylic monomer can be used. These are commercially available, for example,
2- commercially available from Daicel Chemical Industries, Ltd. as Praxel-FA series and Praxel FM series
A hydroxyethyl (meth) acrylate / ε-caprolactone adduct, a polyalkylene glycol mono (meth) acrylate, or the like can be used in combination.

The monomers copolymerizable with the hydroxyl group-containing acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, and t-butyl (meth) acrylate. Alkyl (meth) acrylates such as -butyl acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate; aromatic vinyl compounds such as styrene and vinyl toluene; acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, and the like. . Glycidyl (meth) acrylate having an epoxy group can also be used. In addition, if necessary, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate,
There are amino group-containing monomers such as (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-butoxymethyl (meth) acrylamide and N-methylacrylamide, and acrylamides.

As mentioned above, acrylyl polyol resins can be modified to have alkoxysilyl as a pendant group. For this purpose, one group having a polymerizable unsaturated bond to silicon, 0 to 2 hydrocarbon groups (typically methyl), and 1 to 3 alkoxy groups (typically methoxy or ethoxy) are used. The bound monomer is
It may be copolymerized with the above-mentioned hydroxyl group-containing acrylic monomer and other ethylenically unsaturated monomers.

Typical examples of the above-mentioned alkoxysilyl group-containing monomer include the following. Vinylmethyldimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloylpropylmethyldimethoxysilane (KBM5
02), γ-methacryloyloxypropyltrimethoxysilane (KBM503), γ-[(2-propene-2
-Yloxycarbonyl) benzoyloxy] propylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane (KBE502), and γ-methacryloyloxypropyltriethoxysilane (KBE503)

KBM502, KBM503, KBE50
2 and KBE503 are both commercially available from Shin-Etsu Chemical Co., Ltd. These alkoxysilyl group-containing monomers are preferably used so that the acrylic polyol resin has an alkoxysilyl equivalent described later.

Here, "alkoxysilyl equivalent" means the resin molecular weight per hydrolyzable alkoxy group having a silicon atom bonded thereto. The alkoxysilyl group-containing modified acrylic polyol resin that can be used in the present invention has an alkoxysilyl equivalent of 650 or more, preferably 9 or more.
00 or more, and more preferably 1500. If the alkoxysilyl equivalent is less than this value, the curing time -Si-
O-Si-bonds and -Si-OC-bonds are easily formed, and although the coating film hardness is developed, it is not preferable because it adversely affects acid resistance and alkali resistance. Further, since the alkoxysilyl group is excessively present, problems such as gelation by moisture and generation of cracks after forming a coating film are likely to occur.

(Modified) Polyester Polyol Resin As is well known, a polyester resin is a polycondensate of an acid component mainly composed of a polycarboxylic acid and an alcohol component mainly composed of a polyhydric alcohol.

Examples of the acid component include terephthalic acid, isophthalic acid, phthalic acid or anhydride thereof, aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid and anhydrides thereof; succinic acid, Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Further, lactones such as γ-butyrolactone and ε-caprolactone; and corresponding hydroxycarboxylic acids and aromatic oxymonocarboxylic acids such as p-oxyethoxybenzoic acid; and trimellitic acid, trimedic acid, and pyromellitic acid. The polyvalent carboxylic acid having a valency or higher can be contained in a small proportion.

As the alcohol component, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,5-hexanediol, diethylene glycol, triethylene glycol, 1,4-cyclohexane Diol, 1,4-cyclohexanedimethanol, bisphenol A alkylene oxide adduct, bisphenol S alkylene oxide adduct, 1,2-propanediol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol , 1,2-pentanediol, 2,3-pentanediol, 1,4-pentanediol, 1,4-hexanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, 1,2 -Dodecanediol, 1,2-octane There are aliphatic glycols having a side chain such as decanediol. The alcohol component may also include a small proportion of trihydric or higher polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol and the like.

If necessary, the polyester polyol resin may be combined with another component (a silicone component is an acrylic component). For example, a silicone component can be introduced by a usual condensation reaction with an acid component using (poly) siloxane having a hydroxyalkyl group as an alcohol component. Such resins are also commercially available, for example, from Hitachi Chemical Co., Ltd.
A22-293J (hydroxyl number about 170, Mn = about 2400).

(Modified) Fluorine-based polyol resin Examples of the fluorine-based polyol resin include a hydroxyl group-containing radically polymerizable unsaturated monomer (a), a fluoroolefin monomer (b), and if necessary, other radically polymerizable unsaturated monomers. (C) is obtained by copolymerization with (c).

Examples of the hydroxyl group-containing radically polymerizable unsaturated monomer (a) include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether and hydroxypentyl vinyl ether; ethylene glycol monoallyl ether, diethylene glycol monoallyl ether And hydroxyallyl ethers such as triethylene glycol monoallyl ether.

Examples of the fluoroolefin monomer (b) include so-called difluoroolefin monomers, olefin trifluoride monomers, and olefin tetrafluoride monomers. Specific examples include vinyl fluoride, vinylidene fluoride, and trifluorochloride. Examples include ethylene and ethylene tetrafluoride.

Other radically polymerizable unsaturated monomers (c)
Can be appropriately selected from known monomers in accordance with required coating film properties. For example, ethylene, propylene,
Α-olefins such as isobutylene; vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; vinyl esters such as vinyl acetate, vinyl lactate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, and vinyl caprylate And fatty acid isopropenyl esters such as aliphatic isopropenyl such as isopropenyl acetate and isopropenyl propionate.

The fluorine-based polyol resin may have an acid value, if necessary. In this method, a part of the hydroxyl group of the fluorine-based polyol resin may be subjected to an addition reaction with a polybasic acid anhydride (for example, succinic anhydride or the like) by an ordinary method.

Further, as the fluorine-based polyol resin, the above-mentioned acrylic polyol resin is added to a fluorine-containing polymer having no hydroxyl group, for example, a polymer obtained by copolymerizing (b) alone or (b) and (c). Blended materials are also included.

The acrylic polyol resin to be blended is
The above-mentioned hydroxyl group-containing radical polymerizable unsaturated monomer (a) and / or 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-methacrylic acid
Hydroxyl group-containing radically polymerizable unsaturated monomers such as hydroxyethyl and hydroxypropyl methacrylate; alkyl esters of acrylic acid or methacrylic acid; or ethylenically unsaturated carboxylic acids such as acrylic acid and methacrylic acid; styrene, α -Vinyl aromatic monomers such as methylstyrene and vinyltoluene; amides such as amide compounds of acrylic acid or methacrylic acid and derivatives thereof; and those obtained by copolymerizing acrylonitrile or methacrylonitrile.

Fluororesins or fluorinated polyol resins are commercially available, and include difluorinated polyvinylidene fluoride (PVDF), trifluorinated fluoroethylene vinyl ether copolymer (FEVE), and tetrafluorinated FEVE.
There is a system. The PVDF system is available, for example, as Elf Atochem from Kaina 500. Since this resin does not have a hydroxyl group, the above hydroxyl group-containing acrylic polyol resin is blended and used. As the trifluoride type FEVE system, for example, Lumiflon series of Asahi Glass Co., Ltd., Fluonate series of Dainippon Ink and Chemicals, Inc., and Cefral Coat series of Central Glass Co., Ltd. can be used. Further, as the tetrafluoride type FEVE type, those commercially available from Daikin Industries, Ltd. as Zeffle series can be used. In addition, as a so-called fluorinated acrylic resin, Cotax available from Toray Industries, Inc. can be used. These can be used as they are or, if necessary, by blending with a hydroxyl group-containing acrylic polyol resin to adjust the hydroxyl value.

Preferred fluorine-based polyol resins are tetrafluoride type FEVE type and trifluoride type FE from the viewpoint of durability.
VE system.

(Modified) Silicone Polyol Resin The silicone polyol resin as used herein refers to an organopolysiloxane having at least two alcoholic hydroxyl groups in a molecule, and the modified silicone polyol resin refers to another organopolysiloxane. Refers to a polyol resin blended or grafted with a resin.

Such an organopolysiloxane can be represented by the following composition formula. (R _a ) _n (R _b ) _m Si (O) _{(4-nm) / 2} (1)

Here, _Ra is methyl, C _1-20 alkoxy, aryl, hydrogen, aryloxy, one of C _2-100 containing an ester bond, ether bond, urethane bond or carbon-carbon unsaturated bond in the chain. A valent organic group, R _b
Is a monovalent organic group containing an ester bond, an ether bond, a urethane bond or a carbon-carbon unsaturated bond in the chain and having an alcoholic hydroxyl group at a terminal, and m and n are 0 <
It means a positive real number that satisfies the conditions of n <4, 0 <m <4, and 2 ≦ n + m ≦ 4. The silicone polyol resin applicable to the composition formula (1) is described in JP-A-2-61481.
It is described in. The disclosure of which is incorporated herein by reference. In the resin of the composition formula (1), _Ra is HOC ₂ H ₄
OC ₃ H ₆ —, R _b is methyl, propyl or phenyl, n and m are 0 <n <2, 0 <m <2, and n
A positive real number that satisfies + m <3 is preferable from the viewpoint of ease of production, coating workability, and curability. Above all,
Equation (2)

[0055]

Embedded image

R _a is methyl or phenyl, R _b is HOC ₂ H ₄ OC ₃ H _6- ,
x is 0 or 1, y is 1 to 20, z is 1 to 10, further preferable because the silicone polyol containing 10 to 50 mol% of phenyl as R _a compatibility is good with other resins.

Examples of specific silicone polyols corresponding to the formula (2) are described in JP-A-2-61481 cited above.

This silicone polyol resin is used in combination with another polyol resin. Such resins contain hydroxyl groups and have a hydroxyl number of 5-30.
0, preferably 30 to 200, and the type is not particularly limited. For example, the acrylic polyol resin, the polyester polyol resin, the fluorine-based polyol resin, and the like are used. Also, alkyd resin,
Acrylic-modified alkyd resins, acrylic-modified polyester resins, epoxy resins obtained from bisphenol A and epichlorohydrin, and the like can also be used. The silicone polyol resin may be blended with another polyol resin, or the whole or a part thereof may be reacted in advance. The method includes, for example, reacting an unsaturated double bond and a compound having a functional group other than a hydroxyl group with a trisiloxane having a hydroxyalkyl group, for example, a compound such as maleic anhydride to obtain an unsaturated double bond. By incorporating a component having the following, and by addition polymerization of this part and a double bond part such as acrylic or vinyl monomer,
Both can be combined.

The combination ratio of the silicone polyol to the other polyol resin is 3 to 7 for the silicone polyol resin.
A wide range such as 97 to 30 parts by weight of another polyol resin is possible with respect to 0 parts by weight. Preferably, the former 5
The latter is 95 to 60 parts by weight relative to 40 parts by weight.
When the ratio of the silicone polyol resin falls below the lower limit, the characteristics of the silicone (for example, weather resistance, chemical resistance, etc.) are not sufficiently exhibited. When the ratio exceeds the upper limit, the compatibility of the resin is reduced.

By combining with these resins,
The compatibility between the silicone polyol resin and other additives, the pigment dispersion (stability), and various physical properties (eg, adhesion, elongation, hardness, etc.) according to the intended coating film can be adjusted.

Component (B) One of the components (B) is obtained by blocking a polyisocyanate compound with a blocking agent. A polyisocyanate compound is a compound having at least two isocyanate groups in one molecule. Examples of polyisocyanate compounds include hexamethylene diisocyanate (HMDI) and trimethylhexamethylene diisocyanate (TMDI)
Aliphatic diisocyanates such as isophorone diisocyanate (IPDI); aromatic aliphatic diisocyanates such as xylylene diisocyanate (XDI); tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI) ) And other aromatic diisocyanates; dimer acid diisocyanate (DDI), hydrogenated TD
I (HTDI), hydrogenated XDI (H6XDI),
Hydrogenated diisocyanates such as hydrogenated MDI (H12MDI); dimers, trimers, and high molecular weight polyisocyanates of these diisocyanate compounds;
Examples include polyhydric alcohols such as trimethylolpropane or water, or adducts with low molecular weight polyester resins.

Examples of the blocking agent include oximes such as methyl ethyl ketoxime, acetoxime, cyclohexanone oxime, acetophenone oxime and benzophenone oxime; phenols such as m-cresol and xylenol; methanol, ethanol, butanol and 2-phenol.
Alcohols such as ethylhexanol, cyclohexanol and ethylene glycol monoethyl ether; ε-
Lactams such as caprolactam, diethyl malonate,
Diketones such as acetoacetate; mercaptans such as thiophenol; and the like. In addition, there are many ureas such as thiourea; imidazoles; carbamic acids and the like.

The blocked isocyanate compound is obtained by reacting the above isocyanate compound with a blocking agent by a conventional method until free isocyanate groups disappear.
These are commercially available, Desmodur series (Sumitomo Bayer Urethane Co., Ltd.), Vernock D series (Dainippon Ink and Chemicals, Inc.), Takenate B series (Takeda Pharmaceutical Co., Ltd.), Coronate 2500 series (Nippon Polyurethane Co., Ltd.) Industrial Co., Ltd.) can be obtained. Isocyanate hardeners blocked with oximes, lactams or diketones are preferred.

Another component (B) is an amino resin. Amino resins include melamine resins, benzoguanamine resins, glycoluril resins, urea resins, and the like.
Of these, melamine resins and benzoguanamine resins are common.

Of the melamine resins and benzoguanamine resins, alkyl etherified resins are preferred. Other types, i.e., imino-type and methylol-type, easily react with imino-type melamine resins and methylol-type melamine resins even when a partially hydrolyzed condensate of an alkoxysilane compound is treated with a silane coupling agent, and paint storage stability. It is not preferable because the property is lowered.

Among the alkyl etherified melamine resins, melamine resins substituted with a methoxy group and / or a butoxy group are preferred. This is because in addition to the storage stability of the paint, the melamine resin becomes hydrophobic, so that when formed into a coating film, the melamine resin is unevenly distributed in the upper layer of the coating film, and the crosslink density of the surface layer increases, so that contaminants Stain resistance is improved because the penetration into the interior is suppressed.

A melamine resin substituted with a methoxy group and / or a butoxy group is a melamine resin which is etherified with an i-butyl group or an n-butyl group alone or with a butyl group and a methyl group. can give. The benzoguanamine resin can also be used in the same manner.

Methoxy 60 / butoxy 40 Cymel 238 (same as above) Methoxy 60 / butoxy 40 Cymer 235 (same as above) Methoxy 65 / butoxy 35 Cymer 232 (same as above) Methoxy 40 / butoxy 60 Cymer 236 (same as above) Methoxy 70 / butoxy 30 Cymel 266 (same as above) Same as above Cymer 267 (same as above) Butoxy 100 Mycoat 506 (same as above) Same as above U-Van 20SE (Mitsui Toatsu) Same as above

Component (D) and Component (E) Two types of curing agents having a difference (ΔSP) between the SP value of the polyol resin of the component (A) and the SP value of the curing agent (ΔSP) [Components (D) and (E) Ingredients] can be further improved in stain resistance. Therefore, the component (B)
The component (D) having a solubility parameter value smaller than the solubility parameter value of the component (A) by 0.5 or more;
It preferably contains both component (E) and a component having a solubility parameter value smaller than 0.5.

Component (D) The physical property that the component (D) should have is that its SP value is smaller by 0.5 or more than the SP value of the film-forming resin (A) component. When the SP value is out of this range, since the compatibility with the film-forming resin (A) component is large, the SP value stays inside the coating film during baking and does not float on the surface. Therefore, stain resistance and workability are reduced. (D) component is an amino resin,
In particular, it can be selected from melamine resins. However, since this type of curing agent must not self-condense before floating to the surface in the coating, a difference in SP value of at least 0.5 with the film-forming resin (A) component and a self-condensation Taking the condensability into account, the i-butyl group or n
-A melamine resin which is etherified with a butyl group alone or with a butyl group and a methyl group is preferred.

Commercially available melamine resins satisfying such conditions include the following.

Alkoxy group, mol% SP value Product name Methoxy 60 / i-butoxy 40 10.5 Cymel 238 (Mitsui Cytec) Methoxy 60 / butoxy 40 10.5 Cymel 235 (same as above) Methoxy 65 / butoxy 35 10.4 Cymer 232 (same as above) Methoxy 40 / Butoxy 60 10.1 Cymel 236 (same as above) Methoxy 70 / Butoxy 30 10.6 Cymer 266 (same as above) Same as above 10.6 Cymel 267 (same as above) Butoxy 100 9.5 Mycoat 506 (same as above) Same as above 10.0 Yuban 20SE (Mitsui Toatsu) Same as above 10.5 Yuvan 20N- 60 (same as above)

In addition to the above melamine resins, other amino resins satisfying the above-mentioned conditions, for example, benzoguanamine resins may be used.

Component (E) The physical property that the component (E) should have is that the SP value is larger or equal to or less than 0.5 than the film-forming resin (A). Accordingly, the SP value of the film-forming resin (A) may be less than 0.5, equal to or less than 0.5. When the SP value is out of this range, the initial effect is not exhibited due to low compatibility with the film-forming resin (A). When the compatibility with the film-forming resin (A) is larger than that of the component (D), the resin stays inside the film at the time of baking, and works in a direction to make the crosslinking density uniform over the entire coating film.

[0075] Non-limiting examples of component (E) are etherified melamine resins and blocked isocyanate compounds.

As an example of the component (E), as an etherified melamine resin, for example, the SP value of Sumimar M40S (Sumitomo Chemical Co., Ltd.) is 12.9, and a film-forming resin having an SP value of 9.5 to 12 ( (E) in combination with component (A)
Can be used as a component.

The blocked isocyanate compound as another example of the component (E) is obtained by blocking a polyisocyanate compound with a blocking agent. A polyisocyanate compound is a compound having at least two isocyanate groups in one molecule. Examples of polyisocyanate compounds include hexamethylene diisocyanate (HMD
I), trimethylhexamethylene diisocyanate (T
Aliphatic diisocyanates such as MDI); alicyclic diisocyanates such as isophorone diisocyanate (IPDI); aromatic aliphatic diisocyanates such as xylylene diisocyanate (XDI); tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate Aromatic diisocyanates such as (MDI); dimer acid diisocyanate (DDI), hydrogenated TDI (HTDI), hydrogenated XDI (H6X
DI), hydrogenated diisocyanates such as hydrogenated MDI (H12MDI); dimers, trimers and higher molecular weight polyisocyanates of these diisocyanate compounds; polyhydric alcohols such as trimethylolpropane or water, or And adducts with a molecular weight polyester resin.

Examples of the blocking agent include oximes such as methyl ethyl ketoxime, acetoxime, cyclohexanone oxime, acetophenone oxime and benzophenone oxime; phenols such as m-cresol and xylenol; methanol, ethanol, butanol, 2-
Alcohols such as ethylhexanol, cyclohexanol and ethylene glycol monoethyl ether; ε-
Lactams such as caprolactam, diethyl malonate,
Diketones such as acetoacetate; mercaptans such as thiophenol; and the like. In addition, there are many ureas such as thiourea; imidazoles; carbamic acids and the like.

The blocked isocyanate compound can be obtained by reacting the above isocyanate compound with a blocking agent by a conventional method until free isocyanate groups disappear.
These are commercially available, Desmodur series (Sumitomo Bayer Urethane Co., Ltd.), Vernock D series (Dainippon Ink and Chemicals, Inc.), Takenate B series (Takeda Pharmaceutical Co., Ltd.), Coronate 2500 series (Nippon Polyurethane Co., Ltd.) Industrial Co., Ltd.) can be obtained. Isocyanate hardeners blocked with oximes, lactams or diketones are preferred.

The reaction initiation temperature of the blocked isocyanate is determined by the deblocking temperature of the blocking agent.
It is preferably 50 ° C. or lower. Such blocking agents include methyl ethyl ketoxime (MEK oxime) and β-diketones. The use of the polyisocyanate compound blocked with these blocking agents accelerates the curing of the inside of the coating film, and contributes to the improvement of stain resistance.

According to a particularly preferred embodiment of the present invention,
Combining components (E) and (D) so that component (E) has a lower reaction initiation temperature than component (D). As a result, the compatibility with the film-forming resin (A) is high, and due to dust, the inside of the coating film starts to cure before the surface due to the component (E), so that the coating film is less likely to cling. Here, the reaction initiation temperature is defined as DS
A (dynamic, spring, analysis method) means a temperature measured at a rate of temperature rise of 3 ° C./min by reading at an inflection point of a curve in which Er (relative dynamic elastic modulus) is plotted against temperature. I do.

Component (C) The component (C) is an organosilica sol having a particle size of 10 to 100 n.
m and its hydrophobicity is greater than or equal to 15 ml, expressed in hexane tolerance.

The organosilica sol is a colloid solution in which isolated amorphous colloid particles are dispersed in an organic solvent. The sol generally contains up to 50% by weight of silica,
Although the particle diameter may be up to 300 nm, those usable in the present invention are those having a particle diameter of 10 to 100 nm.

In the paint, an acid catalyst, an amine, a tin-based catalyst, moisture, etc., cause a SiOH group or SiOR
The groups react with each other or with the polyol resin to thicken and reduce storage stability. For this reason, the present invention uses a product obtained by reacting and blocking the surface functional group. Surface SiOH
When the group is blocked, the silica sol particles become hydrophobic.

The degree of hydrophobicity is preferably 15 ml or more as a hexane tolerance value (the measuring method will be described later). If the hexane tolerance value is less than 15 ml, the remaining Si
There are many OH groups, and storage stability is not improved. On the other hand, 50m
If the value is too high, such as 1 or more, the reactivity is reduced and a strong film is not formed, and desired hardness and chemical resistance cannot be obtained.

As described above, the hexane tolerance value measures the degree of hydrophobicity, and the higher the value, the higher the hydrophobicity. The hexane tolerance value is measured by mixing 2 g of silica sol (using a 30% SiO ₂ component) with 10 ml of acetone in a beaker, dispersing the mixture, gradually adding hexane to the mixture, and the mixture becomes cloudy. The amount [ml] of hexane required before the measurement is measured, and the measured amount [ml] of hexane is defined as a hexane tolerance value.
In this method, for example, when the surface of the silica sol is hydrophilic, the silica sol and acetone are initially in a good compatibility state, but become incompatible with the addition of a small amount of hexane, and the measurement system becomes cloudy. Conversely, the higher the hydrophobicity of the silica sol surface, the more hexane is required before cloudiness occurs. Therefore, the degree of hydrophilicity / hydrophobicity of the silica sol surface can be measured by this method.

Examples of the organosilica sol include methanol silica sol in a methanol medium (methanol silica sol manufactured by Nissan Chemical Industries), xylene / butanol medium (XBA-ST manufactured by Nissan Chemical Industry), and MIBK silica sol medium in methyl isobutyl ketone (MIBK) (Nissan). MIBK-ST manufactured by Chemical Industry). Among these, xylene / butanol silica sol and M
It is an IBK silica sol. These hexane tolerance values are shown in Table 1.

[0088]

[Table 1] Table 1 Hexane tolerance value of each silica sol Hexane tolerance value Characteristics ──────────────────────────────── Methanol silica sol 7.9 ml hydrophilic xylene / butanol silica sol 15.3 ml MIBK silica sol 18.0 ml hydrophobic ─────────────────────────────── ─

Further, methanol silica sol and xylene /
Hydrophobization can also be performed by performing silane coupling treatment using butanol silica sol. In this treatment, 10 to 50 parts by weight of a silane coupling agent is added to 100 parts by weight of an organosilica sol as a starting material to cause a reaction. The reaction may be carried out at room temperature for one day or more. When it is necessary to accelerate the reaction to shorten the reaction time, the reaction is heated to an appropriate temperature. At this time, it is necessary to heat the silane coupling agent so that the silane coupling agent does not condense with each other or react rapidly with the silica sol to increase the viscosity or cause gelation. In this treatment, if the amount of the silane coupling agent is small, the storage stability, chemical resistance and gloss of the resulting paint are not improved. Conversely, if the amount of the silane coupling agent is large, it remains in the paint, and the paint film performance such as paint film hardness, water resistance and moisture resistance deteriorates.

The silane coupling agent used in the present invention has a general formula: R ¹ Si (R ² ) _n (OR ² ) _3-n (where R ¹ is alkyl, epoxyalkyl, aryl, alkenyl, aminoalkyl , Mercaptoalkyl or halogenalkyl, R ² is C _1-6 alkyl, and n is 0, 1 or 2.). That is, S
Four substituents of three kinds, one R ¹ , n R ² , and (3-n) OR ² , are bonded to the i atom.

Non-limiting examples of the silane coupling agent used in the present invention include trimethylmethoxysilane, trimethylethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane,
-Decyltrimethoxysilane, n-hexadecyltrimethoxysilane, 1,6-bis (trimethoxysilyl) hexane, γ-ureidopropyltriethoxysilane, γ
-Dibutylaminopropyltrimethoxysilane, nonafluorobutylethyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-
(2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ
-Mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrimethoxysilane, dimethyldimethoxysilane, and octadecyl Dimethyl [3- (trimethoxysilyl) propyl] ammonium chloride and the like.

In particular, a silane coupling agent of a trimethoxysilyl type (where n = 0 and R ² is a methyl group in the above general formula) is preferred because it easily reacts with the silica sol. Preferred R ^{1 in} this case is γ-methacryloxypropyl, γ-glycidoxypropyl, methyl, ethyl, vinyl, phenyl, n-propyl, i-butyl,
n-decyl, n-hexadecyl, trimethoxysilylhexyl, γ-dibutylaminopropyl, nonafluorobutylethyl and the like.

A catalyst can be used in the curing reaction with the catalytic isocyanate. Examples of the catalyst include organotin compounds such as dibutyltin laurate, dibutyltin octate, and dibutyltin diacetate; aluminum tris (acetylacetonate), titanium tetrakis (acetylacetonate), titanium bis (acetylacetonate), and titanium bis (acetylacetonate). ) Metal chelate compounds such as bis (acetylacetonate), titanium bis (isopropoxy) bis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate), zirconium bis (isopropoxy) bis (acetylacetonate) Kind. Tin-based catalysts are common.

An ordinary acid catalyst can be used for the curing reaction with the amino resin. Examples of the catalyst include aromatic sulfonic acids such as dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, p-toluenesulfonic acid, and aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, and the like. Organic phosphonic acids or amine salts thereof.

In the present invention, no more amine is used than is used to neutralize the catalyst. In the invention previously invented by the present inventor (Japanese Patent Application No. 8-78406), the first hardener (corresponding to the component (D) of the present application) floats on the surface of the coating film and the film is used as the first hardener. In addition to selecting a curing agent that is hardly compatible with the forming resin, help was needed by volatilizing the amine to neutralize or block the acid catalyst. Therefore, the amine compound that can be used must have a boiling point of 40 ° C. or more and a baking temperature of the coating film or less.

In the present invention, contamination resistance is achieved by a specific organosilica sol without depending on the surface concentration of the catalyst due to excess amine. That is, the organosilica sol of the present invention, although appropriately blocking silanol groups present on the surface and imparting hydrophobicity, is considered to contribute to the reaction at the time of curing, and therefore, by the reaction with the OH group of the self-condensation resin. It is thought to produce a tight bond on the surface. As a result, a phenomenon similar to the phenomenon of increasing the density of surface crosslinking by curing on the surface of hydrophobic melamine, which is the principle of the development of stain resistance in Japanese Patent Application No. 8-78406, occurs, and high stain resistance is achieved. Conceivable.

Resin Composition The thermosetting resin composition of the present invention comprises component (A) as a main resin, component (B) as a curing agent thereof, and additive (C) as an additive.
Contains components as essential components.

Of the component (B), the blocked isocyanate curing agent is basically compounded so as to have an isocyanate group equivalent to or more than the hydroxyl value of the component (A) which is the main resin. Actually, a composition in the range of 0.8 to 1.5 times the equivalent may be used. Preferably, the equivalent is 1.0 to 1.2 times. If the amount is less than the equivalent, the curability is reduced and only a soft coating film is obtained, and not only the hardness but also the chemical resistance and the stain resistance are reduced. In addition, even if the amount is too large, not only the effect of the addition is not obtained, but also the coating film properties (strength, hardness, workability, etc.) designed by the physical properties of the main resin by blending a large amount of the block isocyanate compound. And chemical resistance also decreases. Further, yellowing and weather resistance of the coating film are liable to decrease.

Of the component (B), the amino resin is in a weight ratio of 9/1 to 5/5 with respect to the polyol resin of the component (A).
5, preferably from 8/2 to 6/4.

As the component (B), two kinds of curing agents, that is, the component (D) and the component (E) can be used. One of the features of the present invention in the compounding aspect in this case is that the component (D) is 0.5 to 10 parts by weight, preferably 2 to 100 parts by weight of the film-forming resin (A) component as solids.
7 parts by weight, and 10 to 50 parts by weight, preferably 20 to 40 parts by weight of the component (E). In other words, the curing agent (E) is the main component, and the component (D) is the auxiliary curing agent. If this ratio is reversed, it becomes difficult to achieve a balance between stain resistance and hardness and workability.

The component (C) has a solid content of 1 to 30 per 100 parts by weight of the total solid content of the components (A) and (B).
0 parts by weight, preferably 10 to 200 parts by weight, more preferably 10 to 100 parts by weight. The coating hardness expected to be less than this is not obtained. On the other hand, when the amount is more than this, the hardness is increased, but the storage stability and the paintability of the paint are reduced. Further, since a large amount of SiOR groups and SiOH groups remain in the coating film, chemical resistance, water resistance, etc. are reduced, and cracks in the coating film are liable to occur.

When two kinds of curing agents are used as the component (B), that is, when the components (D) and (E) are used, the compounding amount of the organosilica sol (C) is as follows. Sum of (D) component and (E) component 10
It is 10 to 100 parts by weight per 0 parts by weight. This significantly improves hardness, chemical resistance (acids and alkalis) and stain resistance. However, if the amount is too large, the processability is reduced, so that it should be avoided. If the amount is too small, there is no effect of improving the hardness.

The reaction catalyst may be added in an amount of 2 parts by weight or less based on 100 parts by weight of the sum of the components (A) and (B). Even without adding a catalyst, curing can be performed by increasing the baking temperature or extending the baking time. If the catalyst is excessively added, the storage stability of the coating material is reduced. Therefore, the amount of the catalyst is 2 parts by weight or less, preferably 1 part by weight or less, based on 100 parts by weight of the sum of the components (A) and (B). More preferably, it should be 0.5 parts by weight or less and kept to the minimum necessary. On the other hand, when the amount of the acid catalyst exceeds 2 parts by weight, abnormalities (shrinkage) of the coating film appearance and chemical resistance are reduced.

The amount of the catalyst added is the same even when two types of curing agents are used as the component (B), that is, the components (D) and (E).

Preparation of paint A paint is prepared by uniformly mixing the components (A) to (C) and adding a pigment or other conventional additives thereto. Generally, the component (A) and the component (C) are mixed and homogenized, and the component (A) or a pigment-dispersed paste prepared using a dedicated pigment-dispersing resin is dispersed therein. The remaining (B) component and, if appropriate, a catalyst, and if necessary, a solvent and other conventional additives are added to form a coating.

The organic solvent may be one generally used for paints, for example, aromatic hydrocarbons such as toluene, xylene, Solvesso 100 and Solvesso 150;
Esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; alcohols such as butanol, octanol and diacetone alcohol; ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and ethylene glycol Monomethyl ether, diethylene glycol monoethyl ether,
Glycol derivatives such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate can be used.
It can be selected in consideration of solubility, evaporation rate, safety and the like.

However, the use of amines is not preferred in order to obtain high storage stability of the paint.

Further, depending on the purpose, titanium dioxide, carbon black, iron oxide, various calcined pigments, cyanine blue,
Color pigments such as cyaningley, extender pigments such as calcium carbonate, clay and barium sulfate, metal powders such as aluminum powder, matting agents such as silica and alumina, defoaming agents, leveling agents, anti-drip agents, surface conditioners, viscosity Conventional additives such as a regulator, a dispersant, an ultraviolet absorber, and a wax can be blended.

The pigment is prepared by forming a dispersion paste with a pigment dispersion resin, and adding a main resin, various additives, a solvent, a curing agent, and a catalyst to the paste. The addition method of the component (C) is as described above, and may be added at that point. Generally, the component (C) is blended with a polyol resin to make it uniform, a pigment paste is made with a polyol resin or a special pigment dispersion resin, and finally, both are mixed, and then a curing agent and a catalyst are added. It is good to finish. The pigment is dispersed using a usual machine such as a roller mill, a paint shaker, a pot mill, a disper, and a bead mill.

The coating is performed by a roll coater, air spray,
General coating methods such as airless spray and curtain flow coater are possible. Use them according to your purpose. The baking conditions are appropriately changed depending on the dissociation temperature of the blocking agent of the block isocyanate or the reaction temperature of the amino resin, but the baking is usually performed at a temperature of 140 ° C. for 20 minutes to 240 ° C. for 30 seconds. In the case of baking in a short time of about 30 seconds to about 2 minutes, the temperature is controlled by the reached plate temperature, and 190 ° C. to 230 ° C.
It is common to do.

The paint according to the present invention can be applied directly to the substrate with one coat, but it is preferable to apply the primer after applying a primer in order to ensure adhesion and corrosion resistance. The primer may be a conventional one, and an epoxy resin primer, a polyurethane-modified epoxy resin primer, or a polyester resin primer is used. The baking method may be 2 coats / 2 bake which is generally performed, or 2 coats / bake.
One bake may be used.

The material is galvanized steel sheet, alloyed galvanized steel sheet, zinc / aluminum plated steel sheet, aluminum plated steel sheet, aluminum or aluminum alloy, stainless steel sheet, copper or its alloy, titanium or its alloy, cold-rolled steel sheet, metal deposit And the like, and a molded product of the metal material. In addition, organic materials such as plastic, composite plastic materials such as FRP, artificial marble,
Inorganic materials such as slate are also possible. These materials may be directly coated or may be subjected to surface treatment. Generally, a metal material is subjected to a zinc phosphate treatment, a reactive chromate treatment, and a coating chromate treatment. Also, a thin film type organic composite coating on chromate is possible.

[0113]

When the silica sol of the present invention is used, the following effects similar to those of ordinary tetraalkoxysilane partially hydrolyzed condensate and reactive ultrafine particle silica are obtained.

(1) Synergistic effect of particle property and reactivity (self-condensability) Since silica sol is a particle and has a reactive functional group, it is considered that a hard agglomerate is likely to be formed in a film at the time of baking. It is considered that the sea / high hardness component = island easily forms a so-called sea / island structure. Therefore, it has the flexibility and strength required for the coating film, and has the ability to suppress cracks in the coating film, and the hardness of the film is easily obtained.

(2) Reactivity (Reactivity with Resin) An alcoholic hydroxyl group (—CH ₂
When it has an OH group) or a SiOR group (which may also include a SiOH group), it is considered that a solid agglomerate in the silica sol film causes a condensation reaction with the OH group or the SiOR group of the resin, and the resin component = sea / It is considered that a structure in which the high hardness component = island is firmly bonded is obtained.

(3) Synthetic effect of BI curing / silica sol On the other hand, when this reactive ultrafine silica is used in a system of a polyol resin as a main resin and a block isocyanate compound as a curing agent, urethane bonds are formed during curing. -Si-O-
It is considered that the ratio of Si-bonds and -Si-OC-bonds decreases. For this reason, -Si-O-Si while maintaining high hardness development resulting from hard particle generation by silica sol
A decrease in chemical resistance due to -bonding or -Si-OC-bonding can be suppressed. As a result, a film having excellent acid resistance and alkali resistance can be obtained while maintaining the coating film hardness at 4H or more.

Further, by using the silica sol hydrophobized in the present invention, that is, the silica sol having a reduced SiOH group or SiOR group on the surface of the silica sol, the storage stability is reduced mainly due to the remaining SiOH group and the chemical resistance is reduced. Reduction and the like are suppressed.

Further, by making the surface hydrophobic, the range of compatibility with the organic resin is expanded. For this reason, film characteristics such as gloss are improved.

The paint using the curable resin composition of the present invention can also be used for PCM and post-coat, and by utilizing the above-mentioned features, roofing materials, wall materials, road materials (fences, poles) of buildings. , Guardrail, highway girder cover,
Pollution resistance (resistance to pollution by raindrops, acid rain, exhaust gas, etc.) and high hardness of exterior metal materials (fences, poles, benches, etc.), automobiles and other outdoor metal products such as aircraft It is particularly suitable for applications where alkali resistance is important.

When two kinds of curing agents are used as the component (B), ie, the component (D) and the component (E), the curable resin composition of the present invention is used as a coating for pre-coated metal, especially for outdoor building materials. The principle that satisfies the required performance described above, particularly the resistance to rain dripping contamination, is considered as follows. That is, the first curing agent (D) is compared with the second curing agent (E) component.
Since the component has low compatibility with the film-forming resin (A) component, it floats on the surface during the baking of the coating film, crosslinks on the coating film surface, increases the crosslink density of the coating film surface portion, and removes contaminants. Suppresses penetration into the interior. Furthermore, although the organosilica sol is interposed and suppressed, moderately reactive SiOR groups condense or self-condense with the melamine resin or OH groups of the resin on the surface of the coating film, thereby crosslinking the coating film surface. It is believed that the density increases.

As a result of measuring the crosslink density of the cured film, it was found that although the bulk was the whole, the addition of the organosilica sol resulted in a 0.7% crosslink density.
It increased from × 10 ⁻³ mol / ml to 3.2 × 10 ⁻³ mol / ml.
It is considered that the above is the reason why high stain resistance is exhibited without using an amine.

On the other hand, the second curing agent (E) component having high compatibility with the film-forming resin (A) component stays inside the coating film, and is compared with the system using only the first curing agent (D) component. (1) The crosslink density is designed to be slightly lower by suppressing excessive curing inside the coating film, and (2) Uniform cross-linking inside the coating film due to the fact that the second curing agent (E) is hardly self-condensed. It is considered that the processability is ensured, and the shrinkage of the coating film is suppressed. Further, the added organosilica sol (C) is uniformly dispersed in the coating film, and the silica sol imparts high hardness to the coating film without impairing workability. In addition, the use of the fine particle silica sol keeps the appearance of the coating film normal.

[0123]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

Production Examples and Examples In the following Production Examples and Examples, "parts" and "%" are by weight unless otherwise specified.

Production Examples 1 to 4 Synthesis of Acrylic Polyol 80 parts of xylene and 20 parts of n-butanol were charged into a reactor equipped with a heating device, a stirrer, and a reflux condenser, and the temperature was raised to 110 ° C. while stirring and maintained. Then, the mixture shown in Table 2 was dropped from the dropping funnel over 3 hours. After completion of the dropwise addition, the temperature was maintained at 110 ° C. for 30 minutes, and then 0.5 part of t-butylperoxy-2-ethylhexanoate was added. After the addition, the mixture was stirred at 110 ° C. for 2 hours, and acrylic resin a,
b, c and d were obtained.

[0126]

[Table 2] Table 2 Monomers (parts) 1 2 3 4} Methyl methacrylate 26.5 35.2 36.7 44.5 Ethyl acrylate 31.6 2-Ethylhexyl methacrylate 23.5 24.7 n-butyl methacrylate 31.5 22.3 32.5 Methacrylic acid 2.0 2-Hydroxyethyl acrylate 18.6 15.8 18.6 PCL FM-21 ₁₎ 31.9 γ-methacryloyloxypropyl trimethoxysilane 4.4 tert-butyl alcohol Oxy-2-ethylhexanoate 1.0 1.0 5.0 1.0 Weight body Acrylic resin abcd ─ Non-volatile content (%) 50.0 50.0 50.0 50.0 Hydroxyl value (mgKOH / g) 80 68 50 80 Number average molecular weight 8000 8000 5000 9000 ────────────────────── ──────── 1) 2-hydroxyethyl methacrylate / .epsilon.-caprolactone (1: 2) addition product, manufactured by Daicel Chemical Industries, Ltd.

Production Example 5 Synthesis of Acrylic Polyol A reactor equipped with a heating device, a stirrer, and a reflux condenser was charged with 49 parts of xylene and 10 parts of cyclohexanone. A mixture of 100 parts of the indicated monomer and 4.5 parts of t-butylperoxy-2-ethylhexanoate was dropped from the dropping funnel over 3 hours. Keep at 115 ° C for 30 minutes after completion of dropping,
Subsequently, 0.5 part of t-butylperoxy-2-ethylhexanoate was added. After the addition, the mixture was further stirred at 115 ° C. for 2 hours to complete the reaction. The resulting acrylic polyol is referred to as e.

Part by weight of monomer Methyl methacrylate 36.7 Ethyl methacrylate 31.4 PCL FM-2 (Note) 31.9 Properties of polymer Non-volatile content (%) 64 OH value (mg KOH / g) 50 SP value 11. 5 Mn 5000 (Note) Addition of 2-hydroxyethyl methacrylate / ε-caprolactone (1: 2), manufactured by Daicel Chemical Industries, Ltd.

Production Example 6 Synthesis of Polyester Polyol A polyester polyol was synthesized according to a conventional method. Dimethyl terephthalate 36.2 was added to a reactor equipped with a heating device, a stirrer, a reflux device, a water separator, a rectification column, and a thermometer.
, 20.1 parts of neopentyl glycol and 22.8 parts of 1,6-hexanediol, and heated. If the raw materials are melted and stirring becomes possible, dibutyltin oxide 0.02
Then, stirring was started, a transesterification reaction was performed, and methanol was distilled off. After cooling to 100 ° C, 31.0 parts of isophthalic acid and 4.2 parts of ε-caprolactone (trade name: Praxel M, manufactured by Daicel Chemical Industries, Ltd.) were charged, and the reaction temperature was raised to 250 ° C. However, 180 ° C ~ 25
The temperature was raised at a constant temperature rate over 4 hours to 0 ° C. The generated condensed water was distilled out of the system. When the temperature reached 250 ° C., the temperature was maintained. After 1 hour, 5 times of xylene was gradually added as a reflux solvent in the reactor, and the reaction was switched to condensation in the presence of a solvent and the reaction was continued. The reaction was terminated when the resin acid value reached 1.0, cooled to 100 ° C., and 50 parts of Solvesso 150 and 50 parts of cyclohexanone were added to add 50% of non-volatile content, hydroxyl value of 15 KOH mg / g,
A polyester resin having a number average molecular weight of 8,000 was obtained. Let the obtained polyester polyol be f.

Production Example 7 Synthesis of Polyester Polyol Neopentyl glycol 20 was placed in a reactor equipped with a heating device, a stirrer, a reflux device, a water separator, a rectification tower, and a thermometer.
, 15 parts of 1,6-hexanediol, 6.5 parts of trimethylolpropane and 26 parts of ε-caprolactone were charged and heated to 100 ° C. After the raw materials were melted and allowed to be stirred, 0.02 parts of dibutyltin oxide and 57 parts of isophthalic acid were charged and the temperature was raised to 230 ° C.
However, the temperature was raised at a constant rate over 3 hours from 180 to 230 ° C. The generated condensed water was distilled out of the system. 23
After keeping the temperature at 0 ° C. for 1 hour, 5 parts of xylene was gradually added, and the reaction was switched to the reaction in the presence of a solvent. When the acid value of the resin reached 7.0, the reaction was terminated.
50 45 parts and xylene 23 parts were added to obtain a polyester resin. Non-volatile content 60%, SP value 10.7, OH value 5
The number average molecular weight was 4,000. Let the resulting polyester polyol be h.

Production Example 8 Synthesis of Modified Silicone Polyol A modified silicone polyol was produced according to JP-A-2-641871. Average composition formula

[0132]

Embedded image

In a reactor equipped with a heating device, a stirrer and a reflux condenser, 20 parts of a polysiloxane having the above average composition, 1.2 parts of maleic anhydride and 0.0 part of dibutyltin oxide were added.
4 parts and xylene 25 parts were charged, and the reaction temperature was 90 ° C.
Incubate for 1 hour. Next, 35 parts of xylene and 20 parts of methyl isobutyl ketone are added, and the temperature is raised to 110 ° C. 11
The mixture shown in Table 3 was added dropwise to the system maintained at 0 ° C over 3 hours. After completion of the dropping, the temperature is maintained at 110 ° C. for 30 minutes, and then t
-Butyl peroxy-2-ethylhexanoate 0.5
Parts were added. After the addition, the mixture was further stirred at 110 ° C. for 2 hours to obtain a modified silicone resin.

[0134]

TABLE 3 Monomer (part) 部 Methyl methacrylate 40.0 2-Ethylhexyl methacrylate 25.0 Methacrylic acid 3.0 2-Hydroxyethyl acrylate 12.0 t-butylperoxy-2-ethylhexanoate 1.2 Modified silicone polyol ───────────── Nonvolatile content (%) 55.0 Hydrosilyl value (mgKOH / g) 85 Number average molecular weight 6000 ───────────────── ────────────

Production Example 9 Production of Silane Sol Treated with Silane Coupling 20 parts (net amount) of γ-glycidoxypropyltrimethoxysilane and 100 parts (net amount) of methanol silica sol
Was mixed, uniformly stirred, heated to 30 ° C., and stored for 8 hours. A liquid composition containing silane-coupled silica was obtained. The silane-coupling-treated silica sol thus obtained is designated as S1.

Production Example 10 Production of Silane Sol Coated with Silane Coupling 20 parts (net amount) of γ-glycidoxypropyltrimethoxysilane and 100 parts (net amount) of methanol silica sol
After stirring uniformly, the mixture was heated to 40 ° C. and stored for 8 hours. A liquid composition containing silane-coupled silica was obtained. The silane-coupling-treated silica sol thus obtained is referred to as S2.

Production Example 11 Production of Silane Sol Coated with Silane Coupling 20 parts (net amount) of γ-methacryloxypropyltrimethoxysilane and 100 parts (net amount) of methanol silica sol
After stirring uniformly, the mixture was heated to 40 ° C. and stored for 8 hours. A liquid composition containing silane-coupled silica was obtained. The silane-coupling-treated silica sol thus obtained is referred to as S3.

Preparation Method of Coating Examples 1 to 8 and Comparative Examples 1 to 3 Pigments, polyol (A) component and organosilica sol (C) component were added together with glass beads in amounts shown in Table 4 together with glass beads.
The mixture was dispersed in a G mill at 30 ° C. for 1.5 hours. The degree of dispersion was measured with a grain gauge and found to be 5 microns or less. Further, 0.1% of dibutyltin dilaurate as a catalyst and 0.3% of dimethylaminoethanol p-toluenesulfonate in a polyester / melamine resin system are used as a catalyst in the amounts shown in Table 4 and dibutyltin dilaurate as a catalyst. It was added and stirred with a disper to prepare a paint. The numerical values in the table are parts by weight as solids.

Examples 9 to 12 and Comparative Examples 4 to 6 130 parts of titanium dioxide and 50 parts (in terms of solids) of resin (A) were dispersed together with glass beads in an SG mill at 30 ° C. for 1.5 hours. The degree of dispersion was measured with a grain gauge and found to be 5 microns or less. Further, the remaining resin (A) 50
Parts and the remaining components (C) to (E) were sequentially added in the amounts shown in Table 5, and after stirring with a disper, 3 parts of an antifoaming agent was added.
3 parts of wax was added, and the mixture was stirred again with a disper. In a system containing a blocked polyisocyanate, 0.2 parts of dibutyltin dilaurate was added.

Coating plate adjustment method (1) Material: zinc-plated galvanized steel sheet with a thickness of 0.4 mm (2) Primer: polyester resin-based primer (Flexcoat P600 primer: manufactured by Nippon Paint Co., Ltd.) Apply with a bar coater so that the film thickness becomes 5 microns,
Baking (attained plate temperature of 220 ° C., time of 1 min) was performed. (3) Overcoating: The composition prepared above was applied and baked with a bar coater (attained plate temperature of 220 ° C., time of 1 min) to a dry film thickness of 20 μm. Each coated plate was tested for necessary ones among appearance, curability, stain resistance, hardness, workability, chemical resistance, humidity stability and film forming property according to the following test methods, and the results shown in Tables 4 and 6 were obtained. I got

Further, as shown in Tables 4 to 6, coated plates were prepared for comparative examples necessary for comparison with the corresponding examples, and the same tests as those of the examples were performed.

Test Method Appearance: The presence or absence of shrinkage of the coating film and the smoothness were visually determined. ◎ Very good: ○ Good: × Poor

Curability: The gauze impregnated with xylene was rubbed 100 times back and forth on the coated plate with a load of 1 kg, and the state of the coating film was examined. ○ No change: △ Partial dissolution: × Base exposure

Stain resistance: [Natural raindrop] The coating film was exposed to natural rainfall for three months, stained, and then visually inspected when washed with water.汚 れ Stain is removed: × Stain remains. Further, the color difference change ΔE between before exposure and after washing with water was measured. [Magic ink] Oil-based magic ink (red) on coated plate
Then, a line was drawn using a felt pen, dried at room temperature for 24 hours, wiped off with a pad soaked with ethanol, and examined for traces. ○ No trace: △ Slight trace: × Trace size [Carbon] About 2 ml of a 10% carbon black aqueous dispersion was dropped on a coated plate, dried at 80 ° C for 24 hours, wiped off with a pad soaked with water, and measured using a color difference meter. Is used to measure the color difference ΔE between the non-contaminated area and the contaminated area after wiping. [Dust] Yoshizawa et al., Published by the Japan Society of Architectural Finishing Engineers, 1995, Academic Lectures, pp. 203-206.
Minutes after contaminating the coating film, washing with water and changing the color difference from the initial value ΔE
Was measured.

Hardness: Pencil hardness according to JIS S-6006

Alkali resistance: 20% in 5% NaOH solution
The appearance of the coating film after immersion at 24 ° C. for 24 hours is observed. ○ No change: △ With blister: × Dissolution of coating film

Acid resistance: 24 ° C. in a 5% HCl solution at 20 ° C.
Observe the appearance of the coating after immersion for a period of time. ○ No change: △ With blister: × Dissolution of coating film

Humidity stability: 2 ml of paint in a bottle having a diameter of 20 mm
After putting 0 g in an open state and leaving it for 24 hours in an environment at a temperature of 20 ° C. and a humidity of 70%, a mixed solution (10 g of xylene, 10 g of n-butanol) is added, and the state of the system after being stirred is observed. ○ No change in dissolved state: × gel state

Film forming property: The state of the coating film when coated by the above coating method is visually judged. ○ Smooth and no shrinkage: × Shrinkage and cracks

Paint storage stability: Stored at 40 ° C. for one month, and measure and judge the viscosity of the paint. ○ No thickening (viscosity increase 1.2 times or less): △ Thickening (viscosity increase within 2 times): × thickening gel

Workability: The coated plate was bent at 180 °, and the minimum T number that did not cause cracking at the bent portion was recorded. For example, 2T means that two steel plates having the same thickness are sandwiched during bending.

Pigment type : TAIPEK CR97: titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.

Other types of polyol resin (A) TA22-293J: Polyester polyol hydroxyl value 171 manufactured by Hitachi Chemical Co., Ltd. Zeffle GK300: Fluorine-containing polyol hydroxyl value 60 manufactured by Daikin Industries, Ltd.

Types of curing agent (B) Desmodur BL3175: HMDI MEK oxime block Coronate 2515 manufactured by Sumitomo Bayer Urethane Co., Ltd. HM manufactured by Nippon Polyurethane Co., Ltd.
DI lactam block Desmodur BL4165: Sumitomo Bayer Urethane Co., Ltd. IPDI MEK oxime block Cymel 235: Mitsui Cytec Co., Ltd. alkyl etherified melamine resin (methoxy 60 / butoxy 40)

Types of curing agent (D) Cymel 238: Alkyl etherified melamine resin of methoxy / isobutoxy = 60/40 manufactured by Mitsui Cytec Co., Ltd. Cymel 232: Alkyl etherified melamine resin of methoxy / butoxy = 65/35 manufactured by Mitsui Cytec Uban 20SE: butyl etherified melamine resin manufactured by Mitsui Toatsu

Types of curing agent (E) Desmodur TPL2062: Diethyl malonate HMDI cyanurate manufactured by Sumitomo Bayer Urethane Co., Ltd. Desmodur BL3175: MEK oxime block HMDI cyanurate Sumimal M40S manufactured by Sumitomo Bayer Urethane Co., Ltd .: Alkyl etherified melamine manufactured by Sumitomo Chemical Co., Ltd. resin

Kind of Acid Catalyst Catalyst 6000: Dodecylbenzenesulfonic acid catalyst manufactured by Mitsui Toatsu Co., Ltd.

[0158]

[Table 4]

[0159]

[Table 5]

[0160]

[Table 6]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08K 5/54 NGD C08K 5/54 NGD 7/16 NGE 7/16 NGE 9/06 9/06 C08L 61/20 LNL C08L 61/20 LNL 75/04 NGF 75/04 NGF C09D 161/20 PHK C09D 161/20 PHK 175/04 PHP 175/04 PHP PHW PHW // B05D 5/00 B05D 5/00 H

Claims (23)

[Claims] (A) having a hydroxyl number of 5 to 300,
A film-forming polyol resin having a number average molecular weight of 500 to 20,000, (B) a blocked isocyanate curing agent and / or an amino resin which reacts with the resin (A), and (C) a particle size of 10 to 100 nm. A thermosetting resin composition comprising, as essential components, an organosilica sol having a hydrophobicity of 15.0 ml or more as a hexane tolerance value. 2. The thermosetting resin composition according to claim 1, wherein the component (B) comprises only one of a blocked isocyanate curing agent and an amino resin. 3. The component (B) wherein the solubility parameter value of the component (B) is 0.5 or more smaller than the solubility parameter value of the component (A), and the solubility parameter value of the component (A) is greater than or equal to or less than 0.5. The thermosetting resin composition according to claim 1, which comprises both the component (E) having a small solubility parameter value and the component (E). 4. The composition according to claim 1, wherein the component (A) is an acrylic polyol resin,
The thermosetting resin composition according to any one of claims 1 to 3, wherein the thermosetting resin composition is selected from a polyester polyol resin, a fluorine-containing polyol resin, a silicone polyol resin, or a combination thereof. 5. The solubility parameter of component (A) is 9.5.
The thermosetting resin composition according to claim 3, wherein 6. The thermosetting resin composition according to claim 1, wherein the component (B) is a polyisocyanate compound blocked with a lactam, oxime or diketone and / or an alkyl etherified melamine resin. 7. The thermosetting resin composition according to claim 6, wherein the melamine resin as the component (B) is an alkyl etherified melamine resin substituted by a methoxy group and / or a butoxy group. 8. The organosilica sol of component (C) may be one or more organosilica sols selected from the group consisting of a dispersion medium of methyl isobutyl ketone or a dispersion medium of xylene / butanol. The thermosetting resin composition according to any one of claims 1 to 7, which comprises: 9. The organosilica sol of the component (C) is represented by the following general formula: R ¹ Si (R ² ) _n (OR ² ) _3-n (wherein R ¹
Is alkyl, epoxyalkyl, aryl, alkenyl, aminoalkyl, mercaptoalkyl or halogenalkyl, R ² is C _1-6 alkyl, and n is 0, 1 or 2. The thermosetting resin composition according to any one of claims 1 to 7, comprising a silane coupling agent-treated organosilica sol treated with a silane coupling agent having the formula (1). 10. The thermosetting resin composition according to claim 9, wherein n = 0 and R ² is a methyl group. (11) R ¹ is γ-methacryloxypropyl,
γ-glycidoxypropyl, methyl, ethyl, vinyl,
Phenyl, n-propyl, i-butyl, n-decyl, n
The thermosetting resin composition according to claim 9, which is selected from the group consisting of hexadecyl, trimethoxysilylhexyl, γ-dibutylaminopropyl, and nonafluorobutylethyl. 12. The thermosetting resin composition according to claim 1, further comprising a catalyst for promoting the reaction between the component (A) and the component (B). 13. The thermosetting resin according to claim 1, comprising 1 to 300% by weight of the component (C) based on the total amount of the components (A) and (B). Composition. 14. The thermosetting resin composition according to claim 1, wherein the polyol resin (A) has a hydroxyl value of 10 to 200. 15. The thermosetting resin composition according to claim 3, wherein the component (D) is an alkyl etherified amino resin. 16. The alkyl etherified amino resin may be n-
The thermosetting resin composition according to claim 15, which is a melamine resin which is etherified with a butyl group or an i-butyl group alone or with an n-butyl group or an i-butyl group and a methyl group. 17. The thermosetting resin composition according to claim 3, wherein the component (E) has a lower reaction initiation temperature than the component (D). 18. The thermosetting resin composition according to claim 3, wherein the component (E) is a blocked polyisocyanate compound or an etherified melamine resin. 19. The component (A), wherein the component (D) is 0.5 to 10% by weight based on the polyol resin, and the component (A) is 10 to 50% by weight based on the polyol resin. 10) to 10 to 10 with respect to the sum of the component (E), the polyol resin of the component (A), the component (D) and the component (E).
0% by weight of the component (C), and the polyol resin of the component (A) and 2% by weight or less of the catalyst based on the sum of the components (D) and (E). , Claim 1
3. The thermosetting resin composition according to 2. 20. The polyol resin as the component (A),
Has a hydroxyl number of １００100 and 9.5 乃至 1
A lactone-modified acrylic polyol resin or a polyester polyol resin having a solubility parameter of 2; wherein the component (D) is an alkyl etherified amino resin, and 0.5% based on the polyol resin of the component (A).
The component (E) is a polyisocyanate compound blocked by a lactam, oxime or diketone;
And 10 to 5 with respect to the polyol resin of the component (A).
0% by weight, and the organosilica sol of the component (C) is a silica sol using methyl isobutyl ketone as a dispersion medium or a silica sol modified with a silane coupling agent, and the component (A) 30 to 60% by weight based on the sum of the polyol resin, the component (D) and the component (E), and the aromatic sulfonic acid or the amine salt of the aromatic sulfonic acid and / or Tin-based catalyst
As a catalyst for accelerating the reaction between the component (A) and the component (D) and / or the component (E), the catalyst may be selected from the sum of the polyol resin of the component (A), the component (D) and the component (E). 0.1
The thermosetting resin composition according to claim 3, which is added in an amount of from 2 to 2% by weight. 21. A thermosetting paint containing the thermosetting resin composition according to claim 1 as a film-forming component. 22. A method for forming a coating film having both stain resistance, chemical resistance and high hardness, which comprises applying the primer according to claim 21 after applying a primer to a metal material and baking and curing. 23. An object having a coating formed by the method of claim 22.