JPH1067945A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition useful for producing coatings capable of imparting coating films having high chemical resistance together with strong hardness by using a film-forming polyol resin, an amino resin hardener, a partially hydrolyzed condensate of an alkoxysilane and a catalyst as essential components. SOLUTION: This thermosetting resin composition consists of (A) a film- forming polyol resin [suitably a (modified) silicone polyol resin, etc.] having 5-300 hydroxyl value and 500-20000 number average molecular weight, (B) an amino resin hardener (preferably an alkyletherified melamine resin, etc., substituted with methoxy groups and/or butoxy groups) capable of reacting with the component A, (C) a partially hydrolyzed condensate of an alkoxysilane compound expressed by the formula [R<1> is a 1-6C alkyl, aryl, etc.; R<2> is a 1-6C alkyl; (n) is 0-2] and (D) a catalyst which accelerates a reaction between the component A and the component B (e.g. dodecylbenzenesulfonic acid) as essential components. As the component C, a reactive silica having <=10Å superfine particle size in the radius of inertia, which is a partially hydrolyzed condensate of tetramethoxysilane, is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is used as a film-forming component of a new thermosetting resin composition, particularly a thermosetting paint excellent in stain resistance, chemical resistance (acid resistance, alkali resistance) and hardness. A thermosetting resin composition.

[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]

SUMMARY OF THE INVENTION The present invention provides a curable resin composition used for producing a paint for forming a coating film having a high level of chemical resistance (acid resistance and alkali resistance) and hardness. I do. More specifically, of stain-resistant paints used for exterior coating materials such as exterior building materials, road materials, vehicles such as automobiles and outdoor coating products such as aircraft, or home appliances, kitchen products, interior building materials, and indoor coating products such as furniture. Provided is a curable resin composition used as a film-forming component.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for forming a composite of an essentially inorganic silica-containing component and an essentially organic resin component into a sea / island or matrix structure in a coating film. By sharing the functions, we were able to simultaneously satisfy all of the desired performances mentioned above.

Therefore, the present invention relates to (A) a compound having a hydroxyl number of 5 to 300 and a number average molecular weight of 500 to 20,000.
And (B) an amino resin curing agent that reacts with the resin (A), and (C) a general formula:
(R ¹ ) _n -Si- (OR ² ) _4-n (where R ¹ is C
_1-6 alkyl, epoxyalkyl, aryl or alkenyl, R ² is C _1-6 alkyl, n is 0,
1 or 2. A) a thermosetting resin composition comprising, as essential components, at least one kind of partially hydrolyzed condensate of an alkoxysilane compound of the formula (I), and (D) a catalyst for promoting the reaction between the resin (A) and the curing agent (B). Offer things.

[0013] 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 THE PREFERRED EMBODIMENTS (A) Component Polyol resins which react with amino resins to form cured coatings 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 polyol resin has a hydroxyl value of 5 to 3
00, the number average molecular weight is 500-20,000. Preferably, the hydroxyl number is between 30 and 200 and the number average molecular weight is between 1,800 and 20,000. 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.

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 a 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 An 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 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.

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 methacrylate. 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 alkoxysilyl group (Si-OR). 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 900 or more, and more preferably 1500. When the alkoxysilyl equivalent is less than this value, a -Si-O-Si- bond or a -Si-OC- bond is easily generated at the time of curing, and although the coating film hardness is developed, the acid resistance and the alkali resistance are adversely affected. Is not preferred. 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.

Examples of the alcohol component include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,5-hexanediol, diethylene glycol, triethylene glycol and 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 difluorinated olefin monomers, trifluoroolefin monomers, and tetrafluoroolefin monomers, and specifically, vinyl fluoride, vinylidene fluoride, and trifluorochloride. Examples include ethylene and ethylene tetrafluoride.

Another radically polymerizable unsaturated monomer (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 as required. 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 FEVE and trifluoride 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)

[0043]

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 may be 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) The 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. The compounding amount of the component (B) is 6/4 to 9 in the ratio of the component (A) / the component (B).
/ 1 is preferred.

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.

Of the alkyletherified melamine resins, melamine resins substituted with methoxy and / or butoxy groups 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.

The 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 (Mitsui Cytec) Methoxy 60 / butoxy 40 Cymel 235 (same as above) Methoxy 65 / butoxy 35 Cymel 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 (C) The component (C) is at least one kind of partially hydrolyzed condensate of an alkoxysilane represented by the following general formula. (R ¹ ) _n -Si- (OR ² ) _4-n

[0055] In the formula, R ¹ is C _1-6 alkyl, epoxy alkyl, aryl or alkenyl, R ² is C
_1-6 alkyl, and n is 0, 1 or 2.

R ¹ is a C _1-6 alkyl group such as a methyl group, an ethyl group or a propyl group; a glycidoxypropyl group;
An epoxyalkyl group such as an epoxycyclohexylethyl group; an aryl group such as a phenyl group and a benzyl group; an alkenyl group such as a vinyl group, an allyl group, an acryloyloxypropyl group, and a methacryloyloxypropyl group. This organic group is used to modify the partially hydrolyzed condensate of the resulting organosilicon compound, for example, when it is desired to improve the reactivity and compatibility with the main resin. Usually, it may be an alkyl group.

R ² is a C _1-6 alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group.

Specific alkoxysilane compounds (hereinafter, referred to as
Examples of “silane monomer”) include (tetrafunctional) tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane; and others, methyltrimethoxysilane, methyltriethoxysilane, and ethyltrimethoxysilane. Silane,
Examples include trifunctional alkoxysilane compounds such as ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane.

The preferred number of n (that is, the number of alkoxy groups) is n = 0 (tetrafunctional) or n = 1 (3
Sensuality). When n> 2, the alkoxysilyl group is consumed when the organosilicon compound is hydrolyzed or condensed, and the reactive functional group (alkoxysilyl group or silanol group) of the partially hydrolyzed condensate of the organosilicon compound is consumed. The number decreases and the curing reactivity decreases. The case where n = 0, that is, the case of tetraalkoxysilane is particularly preferred.

The preferred number of carbon atoms of the substituent R ² is C ₁ -C
₃ That is, the alkyl group is a methyl group, an ethyl group, or a propyl group. C ₁ and C ₂ are particularly preferred. If the carbon number is too large, the hydrolysis / condensation reaction becomes slow,
It is not easy to produce a partially hydrolyzed condensate of the alkoxysilane compound. In addition, when a partially hydrolyzed condensate of the alkoxysilane compound is used in a coating, baking and curing require a high temperature and a long time.

Examples of preferred alkoxysilane compounds include:
Examples include tetramethoxysilane, tetraethoxysilane, ethyltrimethoxysilane, and methyltriethoxysilane. Particularly preferred are tetramethoxysilane and tetraethoxysilane.

The partially hydrolyzed condensate of the alkoxysilane compound can be obtained by a known method. For example, in order to obtain a partially hydrolyzed condensate from a silane monomer, it can be obtained by adding a required amount of water and a catalyst and removing an alcohol generated by a hydrolysis / condensation reaction. In addition, oligomers (condensates)
, An oligomer having a higher degree of polymerization may be synthesized. The amount of water required here is determined from the desired hydrolysis rate. Here, the hydrolysis rate is a value calculated by the following equation, taking a tetraalkoxysilane monomer as an example. _{Si (OR) 4 + nH 2} O → Si (OR) 4 -n O n +2
_n ROH hydrolysis rate% = 2n / 4 × 100 = n / 2 × 100

The hydrolysis rate for obtaining a partially hydrolyzed condensate is theoretically 0% <hydrolysis rate <100%. 100% hydrolyzate is complete the SiO ₂ solid, which rate of hydrolysis is more than 70% have a gelatinous gel or solid, and hydrolysis rate of 65% to 7
Those having a viscosity of up to 0% have a high viscosity and further react with a small amount of water in the air to cause gelation, resulting in poor storage stability. Therefore, a hydrolysis rate of about 30 to 60% is most preferable. However, even when the hydrolysis rate is close to 100%, sufficient storage stability may be exhibited depending on the selection of an appropriate solvent and the like, and thus the hydrolysis rate is not limited to this range.

The water used for the hydrolysis is not particularly limited.
In general, if impurities such as ions remain in the coating film, the performance of the coating film deteriorates. Therefore, deionized water, pure water, or ultrapure water is used depending on the target coating film.

In order to obtain a partially hydrolyzed condensate by hydrolyzing and condensing the alkoxysilane compound, a catalyst can be used if necessary. Examples of the catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, organic acids such as carboxylic acid and sulfonic acid, and inorganic and organic bases such as ammonia, sodium hydroxide and amine. As the solvent, alcohol, ether,
Ketone or the like can be used.

The partially hydrolyzed condensate of the alkoxysilane compound thus obtained is an oligomer,
Dimers, trimers, and higher multimers are mixed,
When the monomer is contained, the storage stability of the partially hydrolyzed condensate itself may be reduced, or the storage stability of a curable resin composition using the same may be reduced.
Further, it is not preferable because the coating film performance (for example, water resistance, acid resistance, alkali resistance, and crack resistance) of a coating material using the same may be reduced. Preferably, the monomer is removed so that the amount of the monomer is 1% by weight or less, more preferably 0.3% by weight or less. A known method may be used for removing the monomer.

Products obtained by removing the tetraalkoxysilane monomer to 1% by weight or less from the tetraalkoxysilane partially hydrolyzed condensate are already commercially available and can be obtained as MK silicate MS51 and MS56 from Mitsubishi Chemical Corporation.

Among the partially hydrolyzed condensates of the alkoxysilane compound, the partially hydrolyzed condensate of tetramethoxysilane is preferable because of its high reactivity. In this case, it does not require a high temperature and a long time for baking hardening when used in a paint.

In the case of tetramethoxysilane, the degree of hydrolysis of the partially hydrolyzed condensate is preferably from 10 to 65.
%, More preferably 30 to 60%. Such partially hydrolyzed condensates of tetramethoxysilane are commercially available, for example, MK silicate MS51 (hydrolysis rate about 40%, SiO ₂ component about 52%), and MSK silicate MS56 (hydrolysis rate about 50%, SiO 2 (About 56% of _two components) (all manufactured by Mitsubishi Chemical Corporation).

A corresponding partially hydrolyzed condensate is similarly produced from tetraethoxysilane. Of the tetraethoxysilane partially hydrolyzed condensates, those having a SiO ₂ content of 40% are often used. ES-40 (Colcoat Co., Ltd.), silicate 40 (Tama Chemical Co., Ltd.), TE
S40 (Hoechst), Sylbond 40 (Stoffer), ethyl silicate 40 (Union Carbide)
It is commercially available from, for example. Those having other SiO ₂ contents can also be used. These condensates are oligomers, and include a mixture of monomers, dimers, trimers, and higher polymers. It is not preferable that a low molecular weight component such as a monomer is mixed, because the coating film performance (for example, water resistance, acid resistance, alkali resistance, and coating film crack) using the same is deteriorated. It can be used by selecting a small number. Further, it is preferable that the oligomer is further hydrolyzed and condensed by the above-described method to be used as a partially hydrolyzed condensate.

Usually, the hydrolysis rate is from 0 to 100%. 1
The 00% hydrolyzate is a complete SiO ₂ solid, those having a hydrolysis rate of more than 70% are gelatinous gels or solids, and those having a hydrolysis rate of 65% to 70% have a viscosity of It is high and further reacts with a small amount of water in the air to form a gel, and has poor storage stability and is very difficult to handle.

Such a case can be avoided by leaving the medium (organic solvent such as alcohol) for the hydrolysis and condensation and leaving the partially hydrolyzed condensate in a diluted state.
The hydrolysis rate of the solution diluted with an organic solvent is preferably 2
0 to 100%. If it is less than 20%, the monomer tends to remain.

The component (C) is preferred when the alkoxysilane forms particles and has a radius of gyration according to the small-angle X-ray scattering method. The radius of gyration of the partially hydrolyzed condensate of the alkoxysilane compound of the present invention is as follows. 100Å (10n
m) An ordinary partial hydrolysis condensate of tetraethoxysilane or the like may have an inertia radius of 10 to 20 °. Usually, even the finest particles of dry silica (such as fumed silica) and wet silica (silica sol) used in paints have a particle diameter of 100 ° (10 nm) or more. Partially hydrolyzed condensates are quite different.

Further, the number of functional groups is predominantly larger than that of dry silica (such as fumed silica) or wet silica (silica sol) which is usually used in paints. Normal,
It is 0.1 to 3 mol, preferably 0.5 to 2.7 mol, per mol of Si, including SiOH groups and SiOR groups. The quantitative ratio of the silanol group to the alkoxy group varies depending on the type of the monomer used, the degree of the hydrolytic condensation, the solvent in the hydrolytic condensation step, and the dilution solvent after the condensation. For example, when an alcohol-based solvent is used, the alcohol is exchanged with the original alcohol group. As a result of examining the partially hydrolyzed condensate of tetraethoxysilane (IPA solvent suspension) by H-NMR integration ratio and CHN analysis of the isolated product, two days after hydrolysis, one mole of Si
—OH group: 0.72 ± 0.13 mol, Si—O—Et
Group: 0.64 ± 0.12 mol, Si—O—iPr group
30 ± 0.06 mol. On the other hand, fumed silica (Aerosil 200: particle size of about 100 mm, Nippon Aerosil Co., Ltd.)
), 2 × 10 ⁻⁵ mol of SiOH groups per mol of Si, silica sol (Snowtex O: particle size about 100 °;
Nissan Chemical Industry Co., Ltd.)
OH groups are 4 × 10 ^-5 mol. Thus, it has a large amount of functional groups completely different from ordinary silica. It is believed that the functional groups react with each other or with the resin in the paint upon curing of the paint.

The number of functional groups changes with time, but when left at room temperature for 60 days after hydrolysis, they become 0.4 mol, 0.36 mol, and 0.17 mol, respectively, per mol of Si. It can be seen that the stability is also excellent.

The most preferred alkoxysilane partially hydrolyzed condensate as the component (C) of the present invention is reactive ultrafine silica. This is based on PCT / JP94 / 02169 (W
O95 / 17349).

This is the amount required to hydrolyze and condense all the alkoxy groups of the starting material using tetramethoxysilane or a partially hydrolyzed condensate thereof as a starting material.
That is, it is characterized in that it undergoes aging and hydrolysis and condensation in the presence of 0.5 mol times or more of water of an alkoxy group.

Specifically, the amount of water used is preferably 0.5 to 1 times, more preferably 0.5 to 0.75 times the alkoxy group. If the amount of water is too large, the liquid tends to gel, and if the amount of water is too small, the formation of reactive ultrafine silica is not sufficient,
The hardness of the obtained coating film may be poor.

When the hydrolysis and condensation are advanced by aging, a curing catalyst can be added as necessary. Examples of the catalyst include inorganic acids such as hydrochloric acid, acetic acid, sulfuric acid, and phosphoric acid, organic acids such as formic acid, propionic acid, oxalic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid, and maleic acid, potassium hydroxide, and water. Alkali catalysts such as sodium oxide, calcium hydroxide, ammonia, etc., organic metals, metal alkoxides, organic compounds such as dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, aluminum tris (acetylacetonate), titanium tetrakis ( Acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), titanium bis (isopropoxy) bis (acetylacetonate), zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetone) There are metal chelate compounds such as lactonate) and zirconium bis (isopropoxy) bis (acetylacetonate), and boron compounds such as boron butoxide and boric acid. The storage stability of the liquid composition and the hardness of the obtained cured product From the viewpoint of excellent properties such as flexibility and the like, it is preferable to use one or more of acetic acid, maleic acid, metal alkoxide, and boron compound.

In this case, reactive ultrafine silica is suspended in an organic or aqueous solvent. It also has a radius of inertia in small angle X-ray scattering measurement. Usually, radius of inertia 10
超 The following ultrafine silica particles have been confirmed, and these are most preferred. In the GPC measurement, the weight average molecular weight is 1000 to 3000 in terms of standard polystyrene, and most of them is 1400 to 2000. For example, the number of moles of a hydroxyl group is based on the number of moles of an alkoxy group,
It is present 0.8 times or more and is extremely reactive. It also has excellent storage stability. Since it can form a film by itself and is rich in reaction, a curable composition using this hardly needs to use a catalyst for curing it. This is the reason for “reactivity”.

The film obtained solely from this reactive ultrafine silica is particularly excellent in high hardness, heat resistance, stain resistance and boiling water resistance. However, according to the present invention, it is formed into a complex with a polyol resin and an amino resin. When cured, the hardness and alkali resistance of the coating film can be significantly improved.

A diluent can be added to the aging during the formation of the reactive ultrafine silica or to the resulting partially hydrolyzed condensate of the alkoxysilane compound. An organic solvent or water may be used according to the purpose. Can be.

As the organic solvent, those used in ordinary coating materials such as alcohols, glycols, hydrocarbons, ketos and ethers can be used. For example, as the alcohol, methanol, ethanol, isopropyl alcohol, n-butanol, i-butanol, n
-Propyl alcohol, octanol, acetone alcohol, etc .; glycol derivatives include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether Propylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc .; hydrocarbons such as benzene, toluene, xylene, kerosene, etc .; esters such as methyl acetate , Ethyl acetate, butyl acetate, acetovinegar The ketones; ethyl etc.
Acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone and the like; as ethers, ethyl ether, butyl ether, dioxane, furan, tetrahydrofuran and the like can be used.

Of these solvents, the use of alcohols, ie, methanol, ethanol, isopropanol, and butanol, provides good storage stability of the partially hydrolyzed condensate. However, since these solvents have a low boiling point and a low flash point, it is preferable to select high boiling hydrocarbons, glycols, and ketones generally used in coating materials and mix them appropriately. The amount of the diluent is, for example, 50 to 5000 parts by weight based on 100 parts by weight of tetramethoxysilane,
Preferably, 100 to 1000 parts by weight of an alcohol solvent is added. If the amount is less than 50 parts by weight, the storage stability of the resulting curable resin composition or paint will decrease.
If the amount is too large, the solvent will enter the coating too much, making it difficult to apply the coating or reducing the thickness of the coating film.

When water is used, the amount of water used for hydrolysis may be increased. Further, water may be added to the hydrolysis product. In the case of a tetramethoxysilane monomer, the amount of water is preferably 20 to 300 parts by weight in combination with water used for hydrolysis, based on 100 parts by weight of the monomer. When the diluent is water, the alkoxysilane condensate is more likely to gel than the organic solvent. In this case, gelation can be suppressed by maintaining the pH at 3 or less, preferably 1 to 2.

The partially hydrolyzed condensate of the alkoxysilane compound of the present invention, for example, an ordinary tetraalkoxysilane partially hydrolyzed condensate (for example, MKC silicate MS5
1 and MS56) tend to have a higher hardness when used in a curable resin composition or a paint than when they are not used.
This is probably because the reactive functional group reacts with the hydroxyl group of the resin for coating or condensation during curing of the coating film to increase the apparent crosslink density.

When used in a polyol resin / amino resin curing agent system, when the polyol resin is cured, it easily reacts with the amino resin, so that the bond constituting the cured film is a —Si—O—Si— bond or , -Si-O─C- bonds are considered to decrease. A decrease in chemical resistance due to -Si-O-Si- bonds and -Si-O−C- bonds can be suppressed while maintaining high hardness.

On the other hand, dry silica and wet silica usually used in paints are as large as 100 ° even if they are small,
Since the number of reactive functional groups (silanol groups) per mole is small, an increase in apparent crosslink density cannot be expected, and the coating film hardness is hardly obtained. In addition, due to the interaction between the surface silanol groups and the interaction with the hydroxyl groups of the resin, even a small amount (approximately 1%) has structural viscosity in the paint and has the effect of preventing sagging. As in the present invention, when the concentration is further increased, for example, 10% by weight, the fluidity of the paint is lost,
It cannot be painted.

Furthermore, the use of particularly preferred reactive ultrafine particle silica exerts the following effects different from ordinary tetraalkoxysilane partially hydrolyzed condensates.

(1) Synergistic Effect of Particle Properties and Reactivity (Self-condensability) The reactive ultrafine silica particles are baked because they have particle properties and have various and many reactive functional groups as described above. When the ultrafine particles themselves are condensed, it is considered that hard aggregates tend to be formed in the film as compared with non-particulate tetraalkoxysilane partially hydrolyzed condensate. Resin component = sea / high hardness component = island so-called sea / It is considered that an island structure is easily formed. Therefore, while having the necessary flexibility and strength of the coating film, while having the ability to suppress cracks in the coating film,
The film hardness becomes easy to come out.

(2) Reactivity (Reactivity with Resin) An alcoholic hydroxyl group (—CH ₂
OH groups) or SiOR groups (which may also include SiOH groups), the reactive ultrafine silica and / or
Alternatively, it is considered that the hard aggregates in the film due to the condensation of the ultrafine particles themselves described in (1) cause a condensation reaction with the OH group or SiOR group of the resin, and the resin component = sea / high hardness component = island. It is believed that the structure is tightly bound.

(3) Synergistic effect of melamine curing / reactive ultrafine silica On the other hand, when this reactive ultrafine silica is used for a polyol resin as a main resin and an amino resin as a curing agent, the amino resin is hardened at the time of curing. And -Si-O-Si- bonds and -S as bonds forming the cured film.
It is considered that the ratio of i-O-C- bonds decreases. For this reason, the chemical resistance due to -Si-O-Si- bonds and -Si-OC- bonds is maintained while maintaining the high hardness due to the formation of hard particles due to the condensation of the reactive ultrafine silica particles and the particles. 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.

Component (D) For the curing reaction with the amino resin of the present invention, a usual acid catalyst can be used. Examples of the catalyst include aromatic sulfonic acids such as dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, and p-toluenesulfonic acid;
And organic phosphonic acids such as aminotri (methylenephosphonic acid) and 1-hydroxyethylidene-1,1-diphosphonic acid, and amine salts thereof.

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.
And the catalyst (D) component as essential components.

The component (B) is preferably blended so as to be 6/4 to 9/1 in terms of the ratio of the component (A) / the component (B). If the amount is less than this, 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, if the amount is too large, not only the effect of the addition is not obtained, but also because the component (B) is blended in a large amount, the coating properties (strength,
Hardness, workability, etc.) and chemical resistance. Further, yellowing and weather resistance of the coating film are liable to decrease.

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. 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. Furthermore, a large amount of SiOR groups and S
Since the iOH groups remain in the coating film, chemical resistance, water resistance, etc. are lowered, and cracks in the coating film are liable to occur.

A linear partially hydrolyzed condensate such as a tetraalkoxysilane partially hydrolyzed condensate other than the reactive ultrafine particle silica, for example, a tetraethoxysilane partially hydrolyzed condensate, is required to obtain a high coating film hardness. 50 to 1
A blend of 00 parts by weight is preferred.

When a highly hydrolyzed tetraalkoxysilane partially hydrolyzed condensate, such as reactive ultrafine silica, is used as the component (C), a high coating film hardness can be obtained even with a small amount of addition.

The reaction catalyst as the component (D) may be added in an amount of 5 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 5 parts by weight, abnormalities (shrinkage) in the appearance of the coating film and chemical resistance decrease. Generally, the component (D) is added in an amount of 0.02 to 5 parts by weight based on 100 parts by weight of the sum of the components (A) and (B).

Preparation of paint A paint is prepared by uniformly mixing the components (A) to (D) 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 components (B) and (D) remaining in the above, 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.

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 preparing 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 according to the reaction temperature of the amino resin, but are 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 coating with 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.

[0107]

According to the present invention, a partially hydrolyzed condensate of an alkoxysilane compound, in particular, a reactive ultrafine particle silica and a polyol resin are baked and cured with an amino resin to form a coating film. , -Si-O
A feature is that a reaction with an amino resin is used without using a —Si— bond or a —Si—O—C— bond. For this reason,
While maintaining the hardness development by the component (C), -Si-O-
A decrease in chemical resistance due to a Si-bond or a -Si-OC- bond can be suppressed. In this regard, a partially hydrolyzed condensate of an alkoxysilane is blended with a polyol resin that has already been proposed, and the condensate is applied to a paint using the condensate as a curing agent, or a resin having an alkoxysilyl group as an essential functional group. This is a completely different point from a paint in which the condensate is blended and the condensate is used as a curing agent.

Further, when reactive ultrafine silica is used in the present invention, reactive ultrafine silica having a wide variety of reactive functional groups and an extremely small radius of inertia of 10 ° is used. It is considered that due to condensation between the two, a hard agglomerate is easily formed in the film, and a resin component = sea / high hardness component = island so-called sea / island structure is easily formed. 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.

The paint using the curable resin composition of the present invention can also be used for PCM and post-coat, and taking advantage of the above characteristics, roof materials, wall materials, road materials (fences, poles, etc.) for 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.

[0110]

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 1 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.

[0113]

[Table 1] Table 1 Monomer (parts) 1 2 3 4 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-human peroxyethyl 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 Polymer 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 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. When the acid value of the resin reached 1.0, the reaction was terminated. The reaction was cooled to 100 ° C., and 50 parts of Solvesso 150 and 50 parts of cyclohexanone were added to add 50% non-volatile content, hydrosilyl value of 15 KOH mg / g,
A polyester resin having a number average molecular weight of 8,000 was obtained.

Production Example 6 Synthesis of Alkoxysilyl Group-Containing Acrylic 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. While maintaining the temperature, the mixture shown in Table 2 was dropped from the dropping funnel over 3 hours. After completion of the dropwise addition, the temperature was kept at 110 ° C. for 30 minutes, and then 0.5 part of t-butylperoxy-2-ethylhexanoate was added. After the addition, the mixture was further stirred at 110 ° C. for 2 hours to obtain an alkoxysilyl group-containing resin.

[0116]

Table 2 (Production Example 6) Monomer (part) （Methyl methacrylate 41. 8 Ethyl acrylate 37.0 n-butyl methacrylate 8.5 γ-methacryloyloxyfluorotrimethoxysilane 12.7 t-butylperoxy-2-ethylhexanoate 1.0 polymer Alkoxysilyl group-containing resin不 揮 発 Nonvolatile content (%) 50.0 Alkoxysilyl equivalent (g / mol) 623 Number average molecular weight 10,000 ０００ ──────────────────────────

Production Example 7 Synthesis of Reactive Ultrafine Particle Silica The reactive ultrafine silica was PCT / JP94 / 02169.
(WO95 / 17349).

In a 500 ml four-necked round-bottomed flask equipped with a stirrer, a reflux condenser and a thermometer, 234 parts of tetramethoxysilane and 74 parts of methanol were added and mixed, and 22.2 parts of 0.05% hydrochloric acid was added. In addition, internal temperature 65
A hydrolysis condensation reaction was performed at 2 ° C. for 2 hours. Next, the condenser was replaced with a distillation tube, the temperature was raised until the internal temperature reached 130 ° C., and the mixture was discharged with methanol. Thus, a partially hydrolyzed condensate was obtained (hydrolysis rate: 40%). Degree of polymerization 2
~ 8 oligomers were confirmed, and the weight average molecular weight was 550
Met. The monomer amount in the obtained partially hydrolyzed condensate (hereinafter, referred to as tetramethoxysilane oligomer) was 5%. Subsequently, the tetramethoxysilane oligomer was placed in a flask heated to 130 ° C., and the vaporized monomer was removed from the system together with the inert gas.
The temperature was raised to ° C. and maintained for 3 hours. The amount of the monomer in the tetramethoxysilane oligomer after the removal of the monomer thus obtained was 0.2%. Next, dechlorinated water 6.5 was added to 30.77 parts of the obtained tetramethoxysilane oligomer.
2 parts, 0.31 part of aluminum (tris) acetylacetonate and 62.4 parts of diethylene glycol monomethyl ether as a solvent were added. The amount of water is 1.13 times the amount that can theoretically completely hydrolyze and condense the tetramethoxysilane oligomer. The mixture was allowed to stand at room temperature for one day to obtain a liquid composition containing a colorless, transparent, and homogeneous liquid reactive ultrafine particle silica.

Examples 1 to 6 and Comparative Examples 1 to 5 Methods of preparing paints Pigment, partially hydrolyzed condensate (C) of polyol (A) and alkoxysilane compound were added to glass beads in the amounts shown in Tables 3 and 4. With an SG mill for 1.5 hours at 30 ° C. The degree of dispersion was measured with a grain gauge and found to be 5 microns or less. Further, as the curing agent (B) and the catalyst (D) in the amounts shown in Tables 3 and 4, Catalyst 600 was used.
0 (dodecylbenzenesulfonic acid type, manufactured by Mitsui Toatsu Chemicals, Inc.) was added at 1% based on the solid content of the resin, and the mixture was stirred with a disper to prepare a paint.

Coating plate adjustment method (1) Material: Galvanized steel sheet with a thickness of 0.4 mm treated with zinc phosphate (2) Primer: Dry polyester resin-based primer (Flexcoat P600 primer: 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 of the coated plates was tested for curability, stain resistance, hardness, chemical properties, humidity stability and film forming property according to the following test methods, and the results shown in Tables 3 and 4 were obtained.

Test Method Curability: The gauze impregnated with xylene was rubbed 100 times back and forth with a load of 1 kg on the coated plate, and the state of the coating film was examined. ○ No change: △ Partial dissolution: × Base exposure Stain resistance: The coating film was exposed to natural rainfall for 3 months, contaminated, and visually inspected when washed with water. ○ Stain is removed: × Stain remains Hardness: Pencil hardness according to JIS S-6006 Chemical resistance Alkali resistance: The appearance of the coating film after immersion in a 5% NaOH solution at 20 ° C. for 12 hours is observed.な し No change: あ り Blister present: × Elution of coating film Acid resistance: Observation of appearance of coating film after immersion in 5% HCl solution at 20 ° C. for 12 hours. ○ No change: △ Blister present: × Elution of coating film Humidity stability: 20 g of paint was placed in a bottle having a diameter of 20 mm, left open for 24 hours in an environment at a temperature of 20 ° C. and a humidity of 70%, and a mixed solution (10 g of xylene) , N-butanol 10g)
And observe the state in the system after stirring. ○ No change in the 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

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

Other types of polyol resin (A) TA22-293J: Polyester polyol manufactured by Hitachi Chemical Co., Ltd. Hydroxyl number 171

Types of curing agent (B) Cymel 238: Alkyl etherified melamine resin (Methoxy 60 / butoxy 40) manufactured by Mitsui Cytec Co., Ltd. Cymel 236: Alkyl etherified melamine resin (Methoxy 40 / butoxy 60) manufactured by Mitsui Cytec Co., Ltd.

Partial decomposition condensate of alkoxysilane compound
Kind of (C) MKC silicate MS56: Tetramethoxysilane partially hydrolyzed condensate manufactured by Mitsubishi Chemical Co., Ltd. SiO ₂ content 57 wt% Reactive ultrafine silica: See Production Example 7

[0126]

[Table 3]

[0127]

[Table 4]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09D 201/06 PDL C09D 201/06 PDL (72) Inventor Keita Mizutani 19th Ikedanakamachi, Neyagawa-shi, Osaka No. 17 Inside Nippon Paint Co., Ltd. (72) Kinya Yamakawa, Inventor 19-19, Ikedanakacho, Neyagawa-shi, Osaka Nippon Paint Co., Ltd. Int Co., Ltd.

Claims (11)

[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) an amino resin curing agent that reacts with the resin (A), and (C) a general formula: (R ¹ ) _n -Si- (OR ² ) ) _4-n alkoxy, wherein R ¹ is C _1-6 alkyl, epoxyalkyl, aryl or alkenyl, R ² is C _1-6 alkyl, and n is 0, 1 or 2. A thermosetting resin composition comprising, as essential components, at least one kind of partially hydrolyzed condensate of a silane compound, and (D) a catalyst that promotes a reaction between the resin (A) and the curing agent (B). 2. As solids, component (C) is 1 to 300 parts by weight and component (D) is 0.02 to 5 parts by weight per 100 parts by weight of the total of components (A) and (B). The thermosetting resin composition according to claim 1, which is: (3) The component (A) is an acrylic polyol resin,
3. The thermosetting resin composition according to claim 1, 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. 4. The thermosetting composition according to claim 1, wherein the component (B) comprises one selected from the group consisting of an alkyl etherified melamine resin and an alkyl etherified benzoguanamine resin, or a combination thereof. Resin composition. 5. The thermosetting resin composition according to claim 4, wherein the alkyl etherified melamine resin is a melamine resin substituted by a methoxy group and / or a butoxy group. 6. The method according to claim 1, wherein the component (C) is a partially hydrolyzed condensate of tetra C _1-6 alkoxysilane (R ² = alkyl, n = 0 in the general formula of claim 1). Thermosetting resin composition. 7. The thermosetting resin composition according to claim 6, wherein the tetra C _1-6 alkoxysilane is tetramethoxysilane. 8. The thermosetting resin composition according to claim 7, wherein the partially hydrolyzed condensate of tetramethoxysilane is reactive ultrafine silica having an inertia radius of 10 ° or less. 9. A thermosetting paint containing the thermosetting resin composition according to claim 1 as a film-forming component. 10. A coating film having both stain resistance, chemical resistance and high hardness, which is obtained by applying the thermosetting coating material according to claim 9 after applying a primer to a metal material and baking and curing. Formation method. 11. An object having a coating formed by the method of claim 10.