JPH1088010A - Curable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paint compsn. having high levels of resistance to contamination with raindrops, moldability, storage stability, chemical resistance, and hardness. SOLUTION: This curable resin compsn. comprises as indispensable components 100 pts.wt. hydroxyl-contg. film forming resin (A) having a hydroxyl value of 5 to 300, a first curing agent (B), in an amt. on a solid basis of 0.5 to 10 pts.wt., having a solubility parameter value which is at least 0.5 smaller than that of the film forming resin (A), a second curing agent (C), in an amt. on a solid basis of 10 to 50 pts.wt., having a solubility parameter value which is larger than, equal to, or less than 0.5 smaller than that of the film forming resin (A), and a partial hydrolysis/condensation product (D) of at least one alkoxysilane compd. in an amt. on a solid basis of 1 to 300 pts.wt. based on 100 pts.wt. in total of the components (A), (B), and (C), represented by the formula: (R<1> )n -Si-(OR<2> )4-n (wherein R<1> represents a 1-6 C alkyl, an epoxyalkyl, an aryl, or an alkenyl; R<2> represents a 1-6 C alkyl; and n is 0, 1, or 2). The partial hydrolyzate of the tetramethoxysilane as the component (D) may be treated with a silane coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used as a film-forming component of a new curable resin composition, particularly a thermosetting paint having excellent stain resistance, chemical resistance (acid resistance, alkali resistance) and hardness. The present invention relates to a curable resin composition. A particularly suitable application relates to a paint composition for pre-coated metal having excellent workability used for home electric appliances and building materials.

[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.

[0006] Precoated metal is widely used for home appliances and building materials. It is desired that the precoat metal coating has excellent weatherability and stain resistance, especially in building materials used outdoors, in addition to the contradictory properties of workability and hardness. For example, in the case of pre-coated metal (PCM) used outdoors, traces of rainwater containing dust make the appearance unsightly. In addition, since the effects of acid rain and acid exhaust gas have increased in recent years, it is necessary to take measures for pre-coated metal used for roofing materials, road materials, tunnel interior materials, and the like. In addition, the coating film is damaged by dust in the atmosphere (hard dust such as sand, earth and sand, dust, etc.), and contaminants are apt to enter. Also, for siding materials and tunnel interior materials, use a brush etc. to wash and remove the contamination. Therefore, scratch resistance (high hardness) is required.

[0007] However, conventional paints for pre-coated metals have not been able to satisfy all of the above requirements. For example, Kanai et al., “Materials and Processes” VO
L. No. 6 (1993), 1494-1497 is a precoated metal prepared by blending a polyester resin having a hydroxyl value (OHV) of 8 to 40 and a melamine resin at a solid content weight ratio of 7/3, and thermally curing using a sulfonic acid-based catalyst. It is reported that stain resistance is satisfactory and processability is maintained only when a fully alkylated melamine resin is used as a melamine resin and a sulfonic acid-based acid catalyst is blocked with an amine compound. doing. The mechanism is that a concentration gradient of melamine resin occurs in the thickness direction of the coating film,
Explain that while the melamine concentration is high only near the surface of the coating film and the stain resistance is improved, the melamine concentration inside the coating film is conversely low, so that the flexibility required for workability is maintained as a whole coating film Have been. However, the stain resistance studied here is for oil-based magic ink, and not for raindrops or exhaust gas containing contaminants. Tests have shown that this system is not effective enough for raindrop contamination that is different from oily soils. Further, there is a disadvantage that the coating film shrinks because the vicinity of the surface having a high melamine concentration starts to cure earlier than the inside of the coating film.

[0008] For the purpose of improving the performance such as acid rain resistance, abrasion resistance and weather resistance as a top coating for automobiles, see, for example, JP-A-3-172368 and JP-A-5-320562.
6-41496, 4-36365, 7-2
No. 07223, etc., none of them simultaneously satisfy all of the performances required for the PCM paint used outdoors, especially the resistance to rain dripping contamination. JP-A-6-166846 discloses a coating composition using a lactone-modified acrylic resin for automotive top coating or PCM, but does not satisfy the resistance to rain dripping even if the workability can be satisfied. JP-A-4-173882, JP-A-4-173883, JP-A-4-21482 and the like aiming at improving the coating film hardness do not satisfy workability and resistance to rain dripping contamination. .

Recently, mainly 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 have attracted attention. 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.

[0010] 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

[0011] For this reason, it is excellent in stain resistance, chemical resistance, workability and the like, and at the same time, has high hardness (pencil hardness of 4).
(H or more).

[0012] The present inventors have already cured a film-forming resin mainly composed of a polyol resin with a block isocyanate curing agent, and contained an inorganic silicate-containing component and an organic resin in the coating film. By combining the components into a sea / island structure or matrix structure and sharing their unique functions, we succeeded in satisfying all of the above-mentioned desired properties simultaneously (Japanese Patent Application
8-90132).

Although this coating film exhibits a certain degree of resistance to raindrop contamination due to the hydrophilicity of the added silicate itself, it is not always sufficient. Furthermore, the alkali resistance and the storage stability of the paint were not always sufficient.

The present inventors have achieved a high hardness of 4H to 5H and a sufficient resistance to raindrop contamination by including a specific silica sol in the coating. However, the workability (the test method will be described later). ) Was 8T to 10T (no crack), which was not always sufficient depending on the application (Japanese Patent Application No. 8-78406).

[0015]

SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to achieve a higher raindrop stain resistance than a silica gel or silicate improved raindrop stain resistance by improving the degree of curing of a coating film. At the same time, the workability is also improved by blending an ultrafine silicate component. It is a further object of the present invention to improve the storage stability of a partial hydrolyzate of tetramethoxysilane when used in a coating composition and to further improve the alkali resistance of a coating film.

More specifically, an object of the present invention is to provide a coating composition for PCM, which has acid resistance, alkali resistance and high hardness, and further has improved raindrop stain resistance and processability.

[0017]

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, all of the above-mentioned desired properties (hardness, workability, stain resistance, etc.) were successfully improved, and at the same time, the difference in solubility parameter (SP) value with the main resin (SP). Stain resistance is further improved by combining two curing agents having different [Delta] SP).

Therefore, the present invention relates to (A) a hydroxyl group-containing film-forming resin having a hydroxyl value of 5 to 300, and (B) a first resin having a solubility parameter smaller than that of the film-forming resin (A) by 0.5 or more. A curing agent, and (C) a second curing agent having a solubility parameter value greater than, equal to, or less than 0.5 less than the film-forming resin (A);
And (D) solid content of the general formula: (R ¹ ) _n -Si-
(OR ² ) _{4-n 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. )
And at least one kind of partially hydrolyzed condensate of an alkoxysilane compound of the formula (I).

The partially hydrolyzed condensate of the component (D) has a general formula: R ³ Si (R ⁴ ) _m (OR ⁴ ) _3-m (wherein R ³ is alkyl, epoxyalkyl, aryl, Alkenyl, aminoalkyl, mercaptoalkyl or halogenalkyl, R ⁴ is C _1-6 alkyl, and m is 0.1, or 2). Good. Further, the partially hydrolyzed condensate of the component (D) is a mixture of the partially hydrolyzed condensate treated with the silane coupling agent and the untreated partially hydrolyzed condensate. Is also good.

The principle that the coating composition of the present invention satisfies the above-mentioned performance required for coatings for pre-coated metal, especially for outdoor building materials, particularly resistance to rain dripping contamination, is considered as follows. That is, the first curing agent (B) has a lower compatibility with the film-forming resin (A) than the second curing agent (C), so that the first curing agent (B) floats on the surface of the coating film when it is baked. Increases the crosslink density at the surface of the coating film and suppresses the penetration of contaminants into the interior. On the other hand, the second curing agent (C) having a high compatibility with the film-forming resin (A) stays inside the coating film, and (1) the coating film is harder than the system using only the first curing agent (B). (2) The second hardener C is hardly self-condensed to suppress the excessive hardening inside and is designed to have a slightly lower crosslink density. It is also considered that the shrinkage of the coating film is suppressed. Furthermore, the added alkoxysilane partially hydrolyzed and condensed component (D) has a size that is at least one order of magnitude smaller than that of the silica sol, thereby contributing to the development of high hardness and at the same time improving the processability by increasing the uniformity of the film. Also contributes.

That is, as can be easily understood, in the present invention, different mechanisms are used for the curing reaction of the resin component (A) and the alkoxysilane partially hydrolyzed condensate component (D). That is, the component (A) is cured mainly by urethane bond crosslinking by the blocked isocyanate curing agent (C), which is the second curing agent, and the component (D) is a condensation self-crosslinking reaction of the remaining alkoxy group and / or silanol group. Respectively to cure. However, the resin component (A)
In the cured coating film, a part of the hydroxyl group contained therein and a part of the alkoxysilyl group and the silanol group of the component (D) react with each other, thereby causing chemical reaction between the matrix resin in the cured coating film and the silica-containing component surrounded by the matrix resin. It is believed that a bond is formed and the two components are integrated. Further, by using the component (D) of the ultrafine particles, the appearance of the coating film can be normally maintained.

Further, the present invention controls the reactivity of ultrafine silica by treating the partially hydrolyzed condensate of the alkoxysilane (D) with a silane coupling agent.
Improves the storage stability of paints and the alkali resistance of coatings.

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

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) Film-forming resin: In the field of coatings, resins which are crosslinked by an external crosslinking agent such as a melamine resin or a blocked polyisocyanate to form a cured coating film are well known.
Typical examples of these resins are (modified) acrylic polyol resins, (modified) polyester polyol resins, (modified) fluorinated polyol resins, and (modified) silicone polyol resins. Among them, particularly (modified) acrylic polyol resin and (modified) polyester polyol resin,
It is preferable to balance the solubility parameter (SP) between the component (B) and the component (C), especially a commercially available curing agent.

The physical properties required for the film-forming resin (A) are a hydroxyl value of 5 to 300, preferably 30 to 20.
0. Further hydroxyl number 3
When it is set to 0 to 100, curability and workability are compatible within this range. In general, if the hydroxyl value is less than 5, curing will be poor, and if it exceeds 100, processability will be reduced, and hydrophilic groups will remain in the cured film, and water resistance, acid resistance and alkali resistance of the coating film will be reduced, which is not preferable. Naturally, other physical properties must be within the range to be provided as a film-forming resin for PCM paints.
20 ° C to 60 ° C, number average molecular weight 500 to 20,000,
Preferably, it is in the range of 1,800 to 20,000. 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.

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 the hydroxyl group-containing acrylic monomer 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.

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 molecular weight of one resin when the alkoxysilyl group is expressed as 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. If the alkoxysilyl equivalent is less than this value, -S
An i-O-Si- bond or a -Si-OC- bond is easily generated, and although the coating film hardness is developed, it is not preferable because it has a bad influence on 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 polyvalent carboxylic 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, other components (a silicone component and an acrylic component) may be bonded to the polyester polyol resin. 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 monomer. (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 olefin difluoride, olefin trifluoride, and olefin tetrafluoride, and specific examples thereof 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), fluorinated 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 As used herein, the term “silicone polyol resin” refers to an organopolysiloxane having at least two alcoholic hydroxyl groups in a molecule, and the term “modified silicone polyol resin” refers to an organopolysiloxane that is different from 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)

[0053]

Embedded image

R _a is methyl or phenyl, R _b is the corresponding HOC ₂ H ₄ OC ₃ H ₆ —, and 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 the above-cited JP-A-2-61481.

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 and the fluorine-based polyol resin are used. Further, alkyd resins, 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 formula (1) and adding and polymerizing this portion and a double bond portion such as an acrylic or vinyl monomer, both can be bonded.

The combination ratio between the silicone polyol and 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.

The SP value is determined by adding two kinds of curing agents to the resin (A).
Since it must be selected based on the difference from the P value,
It is desirably in the range of 9.5 to 12, preferably 10.4 to 12, most preferably 11 to 12. When two or more resins are blended and used as the resin (A), the SP value means its weighted average value.

Here, the SP value (solubility parameter) is a measure of the 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 in the turbidity point [delta] _i: SP value ml of solvent: low SP poor solvent mixture System MH: High SP poor solvent mixed system

(B) First curing agent: The physical properties that the first curing agent should have are those whose SP value is a film-forming resin (A)
Is smaller than the SP value by 0.5 or more. When the SP value is out of this range, since the compatibility with the film-forming resin (A) 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. The first curing agent can be chosen from amino resins, especially melamine resins. However, since this type of curing agent must not self-condense before rising to the surface in the coating, a difference in SP value of more than 0.5 with the film-forming resin (A) and a self-condensation In consideration of the properties, 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 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 Cymer 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.

(C) Second curing agent: The physical property of the second curing agent is that the SP value is larger than, equal to, or smaller 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). Since the compatibility with the film-forming resin (A) is larger than that of the first curing agent (B), 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.

Another desirable physical property is that the first curing agent (B)
Having a lower initiation temperature. The reaction initiation temperature referred to here is DSA (dynamic, spring,
(Analysis method), measured at a rate of temperature rise of 3 ° C./min by reading an inflection point of a curve in which Er (relative dynamic elastic modulus) is plotted against temperature. Since the reaction start temperature is lower than the reaction start temperature of the first curing agent (B), the first curing agent (B) starts curing first on the coating film surface, and the occurrence of surface shrinkage can be avoided. .

The second crosslinking agent (C) satisfying these conditions
Non-limiting examples of components are etherified melamine resins and blocked isocyanate compounds.

As an etherified melamine resin, which is one example of the component (C), for example, Sumimal M40S (Sumitomo Chemical) has an SP value of 12.9, and a film-forming resin having an SP value of 9.5 to 12 ( It can be used as the second crosslinking agent (C) component in combination with the component (A).

A blocked isocyanate compound as another example of the component (C) 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.

Component (D) The component (D) 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

[0075] 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, 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 theoretical degree of hydrolysis for obtaining a partially hydrolyzed condensate is 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 are available 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 preferred because of its high reactivity. In this case, when a material which is not subjected to the silane coupling treatment is used as a coating material, it does not require a high temperature and a long time for baking hardening.

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.

The partial hydrolysis-condensation product of tetraethoxysilane usually has a hydrolysis rate of 0 to 100%. The 100% hydrolyzate is a complete SiO ₂ solid with a hydrolysis rate of 7
Those exceeding 0% are gelatinous gels or solids, and those having a hydrolysis rate of 65% to 70% have a high viscosity, and further react with a slight amount of water in the air to form a gel, which causes storage. Poor stability and very difficult to handle.

In such a case, it 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 (D) is preferably the case where 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 usually much larger than that of dry silica (such as fumed silica) or wet silica (silica sol) 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 component (D) of the present invention is reactive ultrafine silica. This is based on PCT / JP94 / 02169 (W
O95 / 17349).

The amount required for hydrolyzing and condensing all the alkoxy groups of the starting material from 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.

More specifically, the amount of water used is preferably 0.5 to 1 times, particularly 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 known 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.

A diluent can be added at the time of aging when forming the reactive ultrafine silica, or a partially hydrolyzed condensate of the produced 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 product formed by the above process has the reactive ultrafine silica suspended in an organic or aqueous solvent. It also has a radius of inertia in small angle X-ray scattering measurement.
Usually, ultrafine silica having an inertia radius of 10 ° or less has been confirmed, and this is most preferred. In the GPC measurement, the weight average molecular weight was 1000 in terms of standard polystyrene.
3,000 of which 14,000 to 2,000
It is. For example, the number of moles of the hydroxyl group is 0.8 times or more the number of moles of the alkoxy group, and the reactivity is extremely high. 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”.

Further, a “silane coupling agent-treated silicate condensate” obtained by further reacting the component (D), particularly the reactive ultrafine particle silica, with a silane coupling agent can also be used.

The silane coupling agent used in the present invention has a general formula: R ³ Si (R ⁴ ) _m (OR ⁴ ) _3-m (where R ³ is alkyl, epoxyalkyl, aryl, alkenyl, aminoalkyl , Mercaptoalkyl or halogenalkyl, R ⁴ is C _1-6 alkyl, and m is 0, 1 or 2.). That is, S
Four substituents of three types, one R ³ , m R ⁴ , and (3-m) OR ⁴ , are bonded to the i atom.

In particular, a silane coupling agent of the trimethoxysilyl type (where m = 0 and R ⁴ is a methyl group in the above general formula) easily reacts with the partially hydrolyzed condensate of an alkoxysilane compound. preferable.

From the viewpoints of suppressing the reactivity of the resulting silicate condensate treated with the silane coupling agent and improving the storage stability, alkali resistance, acid resistance and gloss of the coating,
Preferred R ³ is γ-methacryloxypropyl, γ-glycidoxypropyl, methyl, ethyl, vinyl, phenyl, n-propyl, i-butyl, n-decyl, n-hexadecyl, trimethoxysilylhexyl, γ-dibutylamino Propyl, nonafluorobutylethyl and the like.

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.

The silane coupling-treated silicate condensate is obtained when the sum of the number of moles of the silanol group (SiOH group) and the alkoxysilyl group (SiOR group) of the partially hydrolyzed condensate (D) of the alkoxysilane compound is 100. The silane coupling agent is obtained by uniformly mixing and reacting the silane coupling agent in a molar ratio of 5 to 100, preferably 10 to 50.

The reaction may be carried out at room temperature for about one day under standing or stirring, and there is no particular need to raise the temperature. However, when it is necessary to promote the reaction in order to shorten the processing time or the like, the reaction may be heated to an appropriate temperature. If the reaction is too fast at that time, the silane coupling agent may condense with each other or react rapidly with the silica sol, causing an increase in viscosity or gelation. There is.

When the amount of the silane coupling agent is small, the treatment efficiency is poor, and the storage stability of the paint produced by using the treated silicate condensate, the alkali resistance, acid resistance and Gloss is not improved.
Conversely, if the amount of the silane coupling agent is large, unreacted silane coupling agent remains in the paint, and the paint film performance such as paint film hardness, water resistance and moisture resistance deteriorates.

In the present invention, a partially hydrolyzed condensate of an alkoxysilane not treated with a silane coupling agent and a partially hydrolyzed condensate of an alkoxysilane treated with the silane coupling agent may be used in combination. Good.

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.

Further, when used in a polyol resin / block isocyanate curing agent system, a urethane bond is easily formed at the time of curing, so that the bond constituting the cured film is a —Si—O—Si— bond or a —Si—O—Si— bond. It is considered that the ratio of Si—O─C—bonds decreases. 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, the dry silica and wet silica used for the coating material are generally 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 silica exhibits the following effects different from ordinary tetraalkoxysilane partially hydrolyzed condensates.

(1) Synergistic Effect of Particle Properties and Reactivity (Self-Condensability) Since reactive ultrafine silica particles have particle properties and have various and many reactive functional groups as described above, they are baked. 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 BI hardening / reactive ultrafine particle silica On the other hand, when this reactive ultrafine silica is used for a polyol resin as a main resin and a block isocyanate compound as a hardening agent, Urethane bonds are easily formed, and -Si-O-
It is considered that the ratio of Si-bonds and -Si-OC-bonds decreases. Therefore, while maintaining the development of high hardness resulting from the formation of hard particles due to the condensation of the reactive ultrafine silica particles and the particles, -Si-O-Si- bonds and -Si
A decrease in chemical resistance due to -OC- bonds 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.

Catalyst Component It is usual to use a catalyst for the curing reaction with 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.

Further, a catalyst can be further added for accelerating the curing by self-crosslinking the alkoxysilane component or accelerating the curing of the whole composition. In this case, a catalyst that can be used for forming reactive ultrafine silica can be used. When reactive ultrafine silica is used as the alkoxysilane component, it is excellent in self-crosslinking property, so that it is not necessary to add a catalyst for this purpose.

For the curing reaction with the amino resin, a known acid catalyst used for curing a polyester resin or a hydroxyl group-containing acrylic resin by crosslinking with a melamine resin can be used. Examples thereof include aromatic sulfonic acids such as dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, p-toluenesulfonic acid, and aminotri (methylenephosphonic acid), 1-hydroxyethylidene-
Organic phosphonic acids such as 1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), and diethylenetriaminepenta (methylenephosphonic acid). These are generally used after neutralization with an amine.

One of the features of the present invention in terms of the composition of the resin composition is that the first curing agent (B) is added in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the film-forming resin (A) as solids. Preferably, 2 to 7 parts by weight are blended, and the second curing agent (C) is 10 to 50 parts by weight,
Preferably, the amount is 20 to 40 parts by weight. In other words, the curing agent (C) is the main, and the curing agent (B) 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 block isocyanate curing agent of the component (C) is basically blended so as to have an isocyanate group equivalent to or more than the hydroxyl value of the component (A) as 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.

The component (D) is used in an amount of 1 to 3 per 100 parts by weight of the total solid content of the components (A), (B) and (C).
Add 00 parts by weight. Preferably, it is added in an amount of 10 to 200 parts by weight, more preferably 30 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. Furthermore, a large amount of SiOR groups and SiOH
Since the group remains in the coating film, the chemical resistance, water resistance, etc. are reduced, and the coating film is liable to crack.

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.

In the case of using a highly hydrolyzed tetraalkoxysilane partially hydrolyzed condensate such as reactive ultrafine particle silica as the component (D), a high coating film hardness can be obtained even with a small amount of addition.

In the case of isocyanate curing, the amount of the catalyst component added is (A) and the block isocyanate compound (C).
0.02 to 100 parts by weight of the total solid components
The amount is 5 parts by weight, preferably 0.1 to 2 parts by weight, and more preferably 0.1 to 1 part by weight. Even if it is added in a large amount, a catalytic effect corresponding to it is not seen.

On the other hand, an acid catalyst for melamine curing may not be particularly used, but is used when it is desired to accelerate the curing reaction. Since the amount of the melamine used is small, the catalyst component may be added in a small amount. 0 parts by weight or less, preferably 0.1 part by weight.
2 to 1.0 part by weight. When added in excess of 2.0 parts by weight, abnormalities (shrinkage) in the appearance of the coating film, chemical resistance and storage stability of the coating material are reduced.

Preparation of paint A paint is prepared by uniformly mixing the components (A) to (D) and adding pigments and 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 method of adding the component (D) is as described above, and may be added at this point. Generally, the component (D) is blended and homogenized with a polyol resin, 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, aluminized 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. Organic materials such as plastic, composite plastic materials such as FRP, and inorganic materials such as artificial marble and 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.

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, 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.

[0139]

The principle that the coating composition of the present invention satisfies the above-mentioned performance required for coatings for pre-coated metal, especially for outdoor building materials, especially resistance to rain dripping contamination, is considered as follows. That is, the first curing agent (B) has a lower compatibility with the film-forming resin (A) than the second curing agent (C), so that the first curing agent (B) floats on the surface of the coating film when it is baked. Increases the crosslink density at the surface of the coating film and suppresses the penetration of contaminants into the interior. On the other hand, the second curing agent (C) having a high compatibility with the film-forming resin (A) stays inside the coating film, and (1) the coating film is harder than the system using only the first curing agent (B). (2) The second hardener C is hardly self-condensed to suppress the excessive hardening inside and is designed to have a slightly lower crosslink density. It is also considered that the shrinkage of the coating film is suppressed.

The added alkoxysilane partially hydrolyzed and condensed component (D) is at least one order of magnitude smaller than the silica sol, and contributes to the development of high hardness and, at the same time, improves the processability by increasing the uniformity of the film. Also contributes.

As can be easily understood, in the present invention, different mechanisms are used for the curing reaction of the resin component (A) and the alkoxysilane partially hydrolyzed condensate component (D). That is, the component (A) is cured by urethane bond crosslinking with the blocked isocyanate curing agent (C), and the component (D)
The components are each cured by a condensation self-crosslinking reaction of the remaining alkoxy groups and / or silanol groups. However, part of the hydroxyl group in the resin component (A) and part of the alkoxysilyl group and silanol group in the component (D) react with each other, and the matrix resin in the cured coating film and the silica-containing component surrounded by the matrix resin It is believed that a chemical bond is also formed between the two to integrate the two components.

The film obtained solely from this reactive ultrafine silica is particularly excellent in high hardness, heat resistance, stain resistance and boiling water resistance. When hardened and cured, the hardness and alkali resistance of the coating film can be significantly improved.

By the above-mentioned actions, the raindrop stain resistance and workability are improved, and at the same time, the hardness, alkali resistance and acid resistance are maintained at high levels.

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.

In the present invention, a partially hydrolyzed condensate of an alkoxysilane compound, in particular, reactive ultrafine silica and a polyol resin are baked and cured with a block isocyanate compound to form a coating film. , A -Si-O-Si- bond or a -Si-OC- bond, but a urethane bond is used. For this reason, while maintaining the hardness development by the component (C), -S
A decrease in chemical resistance due to an i-O-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.

[0146]

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 3 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 following 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 acrylic polyols thus obtained are referred to as ac.

[0149]

TABLE 1 Manufacturing Example Monomer (parts) 1 2 3 methyl methacrylate 7.4 36.7 48.4 Ethyl methacrylate 41.6 31.4 ─── n-butyl acrylate ─── ─── 40.2 2-ethylhexyl acrylate ─── ─── ─── 2-hydroxyethyl acrylate ^{─── ─── 1.8 PCL FM-1 1} ) ─── ─── 9.7 PCL FM-2 2 ⁾ 51.0 31.9 ─── polymer acrylic resin a b c nonvolatile content (%) 64 64 64 SP value 11.6 11.5 11.0 OH value (mgKOH / g) 80 50 30 Mn 5000 5000 5000 1) Addition product of 2-hydroxyethyl methacrylate / ε-caprolactone (1: 1), manufactured by Daicel Chemical Industries, Ltd. 2) 2-Hydroxyethyl methacrylate / ε-caprolactone Becton (1: 2) adduct, manufactured by Daicel Chemical Industries, Ltd.

Production Example 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. To the mixture, 36.7 parts by weight of methyl methacrylate, 31.6 parts by weight of ethyl acrylate, and PCL FM-2 [2-hydroxyethyl methacrylate / ε-caprolactone (1: 2) adduct, manufactured by Daicel Chemical Industries, Ltd.]
A mixture consisting of 31.9 parts by weight and 5.0 parts by weight of t-butylperoxy-2-ethylhexanoate was dropped from the dropping funnel over 3 hours. 1 minute for 30 minutes after dropping
Maintained at 10 ° C. and then 0.5 parts of t-butylperoxy-2-ethylhexanoate were added. 2 more after addition
After stirring at 110 ° C. for an hour, an acrylic resin d was obtained. The nonvolatile content was 50%, the OH value was 50, and the number average molecular weight was 5,000.

Production Example 5 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 e. The nonvolatile content was 60%, the SP value was 10.7, the OH value was 110, and the number average molecular weight was 4,000.

Production Example 6 Synthesis of Reactive Ultrafine Particle Silica The reactive ultrafine silica was PCT / JP94 / 02169.
(WO95 / 17349).

234 parts of tetramethoxysilane and 74 parts of methanol were added to a 500 ml four-necked round-bottomed flask equipped with a stirrer, a reflux condenser and a thermometer, and mixed. Then, 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. Leave at room temperature for 1 day, colorless, transparent and homogeneous liquid reactive ultrafine silica active ingredient 2
A liquid composition containing 0% was obtained.

Production Example 7 Production of Silane Condensate Treated with Silane Coupling The suspension of the reactive ultrafine silica particles produced in Production Example 5 was
Three kinds of silane coupling agents, that is, (X) γ-methacryloxypropyltrimethoxysilane, (Y) γ-glycidoxypropyltrimethoxysilane, and (Z) vinyltrimethoxysilane were each added and stirred uniformly. Thereafter, the reaction was allowed to stand at room temperature for one day. The amount of each of the silane coupling agents was determined by the amount of the reactive ultrafine silica suspension 100.
Based on parts by weight, (X) was 20 parts by weight, (Y) was 25 parts by weight, and (Z) was 30 parts by weight.

Coating preparation methods Examples 1 to 10 130 parts of titanium dioxide and 50 parts (solid conversion) 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 (B) to (D) were sequentially added in the amounts shown in Table 2, 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, 0.1 part of dibutyltin dilaurate was added. In addition,
The components without the silane coupling treatment (D) were referred to as Examples 1 to 5, and the components with the silane coupling treatment (D) were referred to as Examples 6 to 10.

[0156] coated plate creation method (1) Material: galvanized steel plate having a thickness of 0.4mm was subjected to zinc phosphate treatment (2) Primer: polyester resin-based primer: dried (flexible coat 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). (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.

The appearance of the coated plate was determined according to the following test method.
The curability, hardness, workability, chemical resistance and stain resistance were tested, and the results shown in Table 4 for Examples 1 to 5 and Table 5 for Examples 6 to 10 were obtained.

Comparative Examples 1 to 3 Paints were prepared in the same manner as in Examples 1 to 5 except that the composition was changed as shown in Table 6, and a coated plate was prepared, and the same test was carried out.
Table 7 shows the results.

Reference Examples 1 and 2 For the purpose of understanding the present invention, the mixing conditions and the like for Reference Examples 1 and 2 are shown in Table 6, and the test results are shown in Table 7.

Comparative Examples 4 to 6 Paints were prepared and coated plates were prepared in the same manner as in Examples 6 to 10 except that the composition was changed as shown in Table 8, and the same test was carried out. Table 9 shows the results.

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

Hardness: Pencil hardness according to JIS S-6006.

Curability: A gauze impregnated with xylene was rubbed by reciprocating 100 times on a coated plate under a load of 1 kg.
Check the condition of the coating. ○ No change: △ Partial dissolution: × Base exposure

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.

Chemical resistance: Acid resistance: A test piece was placed in a 5% aqueous hydrochloric acid solution at 20 ° C. for 24 hours.
The coated surface after immersion for hours was visually evaluated. ○ No abnormalities: × blistering generated Alkali resistance: The coated surface after immersing the test piece in a 5% aqueous sodium hydroxide solution at 20 ° C. for 24 hours was visually evaluated. ○ No abnormality: × blistering

Stain resistance: Magic ink: A line was drawn on the coated plate with an oil-based magic ink (red) 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 large Carbon: 10% carbon black aqueous dispersion about 2 on coated plate
The mixture is dried at 80 ° C. for 24 hours, wiped off with a pad soaked with water, and measured for color difference ΔE between a non-stained area and a stained area after wiping using a color difference meter. Dust: Yoshizawa et al., After contaminating the coating for 15 minutes by the accelerated A method described in Academic Lectures, 1995, pp. 203-206 of the Japan Society for Architectural Finishing, washed with water, and measured the color difference ΔE from the initial value. Natural raindrop: The coating film was exposed to natural rainfall for three months, contaminated, rinsed with water, and the color difference change ΔE from the initial value was measured.

Humidity stability: 2 g of paint in a 20 mm diameter bottle
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 determine the viscosity of the paint. ○ No thickening (viscosity increase 1.2 times or less): △ Thickening (viscosity increase within 2 times): × thickening gel

[0170]

[Table 2]

[0171]

[Table 3]

[0172]

[Table 4]

[0173]

[Table 5]

[0174]

[Table 6]

[0175]

[Table 7]

[0176]

[Table 8]

[0177]

[Table 9]

(Note 1) Types of component (B) Cymel 238: methoxy / isobutoxy = 60/40 alkyl etherified melamine resin manufactured by Mitsui Cytec Co., Ltd. Cymel 232: methoxy / butoxy = 65/35 alkyl ether manufactured by Mitsui Cytec Melamine resin U-Van 20SE: butyl etherified melamine resin Mycoat 506 manufactured by Mitsui Toatsu Co., Ltd. Butoxy 100 manufactured by Mitsui Cytec
Alkyl etherified melamine resin (butylated melamine) Cymel 235: Alkyl etherified melamine resin of methoxy 60 / butoxy 40 manufactured by Mitsui Cytec

(Note 2) Type of component (C) Desmodur BL3175: manufactured by Sumitomo Bayer Urethane Co., Ltd. MEK oxime block HMDI cyanurate Sumimar M40S: alkyl etherified melamine resin manufactured by Sumitomo Chemical Co., Ltd. Desmodule TPL2062: manufactured by Sumitomo Bayer Urethane Co., Ltd. Diethyl malonate block HMDI cyanurate Sunplex BL1200: manufactured by Sanyo Chemical Industries, Ltd.

(Note 3) Types of catalyst components Catalyst 6000: Dodecylbenzenesulfonic acid-based catalyst manufactured by Mitsui Toatsu Co., Ltd. Catalyst 500: Dinonylnaphthalenesulfonic acid-based catalyst manufactured by Mitsui Cytec Co., Ltd.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // (C08L 101/06 61:32) (72) Inventor Saori Yoshimatsu 19-17 Ikedanakamachi, Neyagawa-shi, Osaka Nippon Paint stock In company

Claims (28)

[Claims] (A) a hydroxyl group-containing film-forming resin having a hydroxyl value of 5 to 300; (B) a first curing agent having a solubility parameter smaller than that of the film-forming resin (A) by 0.5 or more; (C) a second curing agent having a solubility parameter value greater than, equal to, or less than 0.5 than the film-forming resin (A); and (D) a solid formula represented by the general formula: (R ¹ ) _n -Si − (OR
² ) _{4-n wherein} R ¹ is C _1-6 alkyl, epoxyalkyl, aryl or alkenyl, and R ² is C _1-6
Alkyl and n is 0, 1 or 2. A) a curable resin composition comprising, as an essential component, at least one kind of partially hydrolyzed condensate of the alkoxysilane compound of the above). 2. The method according to claim 1, wherein the first curing agent of the component (B) is contained in an amount of 0.1 to 100% by weight of the film-forming resin (A) as a solid content.
The curable resin composition according to claim 1, which is added in an amount of 5 to 10 parts by weight. 3. The method according to claim 1, wherein the second curing agent of component (C) is used as a solid in 1 part by weight per 100 parts by weight of the film-forming resin (A).
The curable resin composition according to claim 1, wherein the curable resin composition is added in an amount of 0 to 50 parts by weight. 4. The composition according to claim 1, wherein the component (D) is 1 to 300 parts by weight per 100 parts by weight of the total of the components (A), (B) and (C). The curable resin composition according to any one of the above. 5. The partially hydrolyzed condensate of the component (D) has a general formula: R ³ Si (R ⁴ ) _m (OR ⁴ ) _3-m (wherein R ³
Is alkyl, epoxyalkyl, aryl, alkenyl, aminoalkyl, mercaptoalkyl or halogenalkyl, R ⁴ is C _1-6 alkyl, and m is 0, 1 or 2. The curable resin composition according to any one of claims 1 to 4, wherein the curable resin composition has been treated with a silane coupling agent having the formula: 6. The partially hydrolyzed condensate of the component (D) comprises the partially hydrolyzed condensate treated with the silane coupling agent according to claim 5 and the partially hydrolyzed condensate which has not been treated. The curable resin composition according to any one of claims 1 to 4, which is a mixture with a decomposition condensate. 7. The curable composition according to claim 1, wherein the hydroxyl value of the film-forming resin of the component (A) is from 10 to 200, and the number average molecular weight is from 500 to 20,000. Resin composition. 8. The film-forming resin of component (A) is selected from the group consisting of hydroxyl group-containing acrylic resin or hydroxyl group-containing polyester resin, fluorine-containing polyol resin and silicone polyol resin, or a combination thereof. The curable resin composition according to any one of claims 1 to 7. 9. The curable resin composition according to claim 8, wherein the polyol resin has a solubility parameter value of 9.5 to 12. 10. The curable resin composition according to claim 1, wherein the first curing agent of the component (B) is an alkyl etherified amino resin. (11) the alkyl etherified amino resin is n-
The curable resin composition according to claim 10, which is a melamine resin 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. 12. The method according to claim 1, wherein the second curing agent of the component (C) has a lower reaction initiation temperature than that of the first curing agent of the component (B). Curable resin composition. 13. The curable resin composition according to claim 1, wherein the second curing agent of the component (C) is a blocked polyisocyanate compound or an etherified melamine resin. 14. The component (D) is tetra-C _1-6 alkoxysilane (R ² = alkyl, n = 0 in the general formula of claim 1).
The curable resin composition according to any one of claims 1 to 13, which is a partially hydrolyzed condensate of (1). 15. The curable resin composition according to claim 14, wherein the radius of gyration of the partially hydrolyzed condensate of tetra C _1-6 alkoxysilane is 100 ° or less. 16. The curable resin composition according to claim 14, wherein the tetra C _1-6 alkoxysilane is tetramethoxysilane. 17. The curable resin composition according to claim 16, wherein the partially hydrolyzed condensate of tetramethoxysilane is reactive ultrafine silica having an inertia radius of 10 ° or less. 18. The curable resin composition according to claim 14, wherein the tetra C _1-6 alkoxysilane is tetraethoxysilane. 19. The curable resin composition according to claim 18, wherein the content of tetraethoxysilane is 1% by weight or less. 20. The silane coupling agent is compounded for the reaction in a molar ratio of 0.05 to 1 with respect to the total number of moles of silanol groups and alkoxysilyl groups of the partial hydrolysis condensate. The curable resin composition according to any one of claims 5 to 19, wherein: 21. The curable resin composition according to claim 5, wherein m = 0 and R ⁴ is a methyl group. 22. R ³ is γ-methacryloxypropyl,
γ-glycidoxypropyl, methyl, ethyl, vinyl,
Phenyl, n-propyl, i-butyl, n-decyl, n
22. The curable resin composition according to claim 5, which is selected from the group consisting of hexadecyl, trimethoxysilylhexyl, γ-dibutylaminopropyl, and nonafluorobutylethyl. 23. A coating composition comprising the curable resin composition according to claim 1 as a film-forming component. 24. The curable resin composition according to any one of claims 1 to 22, wherein the composition is based on 100 parts by weight of the film-forming resin of the component (A) and 100 parts by weight of the film-forming resin of the component (A). 0.5 to 10 parts by weight of the first curing agent of the component (B) and 10 to 50 parts by weight of the first curing agent of the component (C) based on 100 parts by weight of the film-forming resin of the component (A). 1 to 300 parts by weight based on a total of 100 parts by weight of the second curing agent, and the film-forming resin (A), the first curing agent (B), and the second curing agent (C). A curable resin composition containing the component (D), the partially hydrolyzed condensate; and the film-forming resin (A) and the first curing agent (B) or the second curing agent (C). 2 parts by weight or less of the film-forming resin and the first curing agent and / or the Coating composition containing a catalyst for promoting the reaction between the curing agent. 25. The film-forming resin as component (A), wherein
The coating composition according to claim 24, which is a lactone-modified polyol resin having a hydroxyl number of 0 to 100. 26. A method for coating a paint, comprising: galvanized steel, alloyed galvanized steel, zinc / aluminized steel, aluminized steel, aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, metal deposited. Applying a primer selected from the group consisting of an epoxy resin-based primer, a polyurethane-modified epoxy resin-based primer and a polyester resin-based primer to a material consisting of a material selected from the group consisting of a material, a stainless steel, and a cold-rolled steel. And 22. The material coated with the primer,
A method comprising: applying the coating composition according to any one of Claims 4 to 4; and baking the applied coating. 27. An object painted by the method of claim 26. 28. A precoated metal steel sheet obtained by applying the coating composition according to any one of claims 23 to 25 to a steel sheet and baking and hardening it.