JP2841810B2 - Organic dosage form thermosetting coating composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel organic solvent type thermosetting coating composition.

[Prior art and its problems] Conventionally, as an organic solvent type paint, a paint obtained by dissolving or dispersing a resin composition containing a hydroxyl group-containing polycarboxylic acid resin and an aminoaldehyde resin in an organic solvent is known. However, they have the drawback that they need to be baked at a temperature of 180 ° C. or higher and the resulting coating films are inferior in chemical properties such as corrosion resistance and acid resistance.
In addition, problems such as cracking of the coating film and environmental pollution due to condensates (such as formalin) generated during baking remain. Also,
In the above conventional paints, those using bisphenol epichlorohydrin type epoxy resin in place of the aminoaldehyde resin thicken and gel the paint system during storage and do not give a practical organic solvent type paint.

[Means for Solving the Problems] The inventors of the present invention have conducted intensive studies for the purpose of stabilizing the storage of the organic solvent type coating composition and improving the performance of the coating film in a well-balanced manner. An organic solvent-based coating composition containing a thermosetting resin composition in which a specific epoxy compound as a crosslinking agent and a quaternary ammonium compound as a reaction catalyst are mixed with a resin having a carboxyl group, and the above-mentioned object can be achieved. Thus, the present invention has been completed.

Thus, the present invention provides a resin (A) having a hydroxyl group and a carboxyl group (hereinafter referred to as “resin (A)”), an epoxy group and / or an alicyclic hydrocarbon on an alicyclic hydrocarbon ring. An epoxy compound (B) having an average of two or more epoxy groups directly bonded to carbon atoms forming a ring in one molecule (hereinafter referred to as "epoxy compound (B)"
And a quaternary ammonium compound (C) as an essential component (hereinafter referred to as "the present invention paint composition (1)"). And an alicyclic polyepoxy compound (D) obtained by reacting the resin (A), an epoxy compound having an epoxy group on a hydroxyl group and an alicyclic hydrocarbon ring with a polyisocyanate compound (hereinafter, referred to as the alicyclic polyepoxy compound (D)). (Hereinafter referred to as “epoxy compound (D)”) and a quaternary ammonium compound (C) as essential components (hereinafter referred to as “the coating composition of the present invention”). Object (2) ”).

In the coating composition of the present invention, in the presence of a base in a quaternary ammonium compound (C), a hydroxyl group and a carboxyl group in a resin (A) and an epoxy compound (B) or (D)
The reaction of the functional groups with the epoxy group in the hardly proceeds at a temperature of about room temperature, and it is considered that the reaction of the functional groups progresses rapidly when baked at a temperature of about 100 ° C. Therefore, it is considered that the coating composition of the present invention exhibits an effect of being particularly excellent in storage stability and coating film low-temperature curability.

Hereinafter, the coating composition of the present invention will be described in more detail.

The resin (A) used in the coating composition (1) of the present invention includes:
There is no limitation as long as it has a hydroxyl group and a carboxyl group, and any resin known in the field of coatings, for example, based on a vinyl resin, a polyester resin, a polyether resin or the like can be used. The following are representatives of such resins.

(1) Examples of the vinyl resin include hydroxyethyl (meth) acrylate and hydroxypropyl (meth).
Hydroxyl-containing monomers such as acrylate, hydroxybutyl (meth) acrylate, polycaprolactone diol mono (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, and carboxyl groups containing (meth) acrylic acid, carboxyethyl acrylate, and itaconic acid Monomers; and, if necessary, methyl (meth) acrylate, ethyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acrylonitrile, acrylamide, styrene, Functional groups that react with hydroxyl groups and carboxyl groups such as vinyl toluene, vinyl acetate, i-propyl vinyl ether, n-butyl vinyl ether, and methoxyethyl vinyl ether That the radically polymerizable unsaturated group-containing monomer were obtained by co-polymerizing the non like.

(2) Examples of polyester resins include polyol components such as trimethylolethane, trimethylolpropane, pentaerythritol, glycerin, ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, and 1,6-hexanediol. And (anhydride) phthalic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, adipic acid,
(Anhydrous) A polyester resin obtained by polycondensation with a polycarboxylic acid component such as trimellitic acid; a polyester resin modified with a fatty acid or an epoxy resin; and an acrylic-grafted modified polyester resin; bisphenol-epichlorohydrin type epoxy resin Modified polyester resins obtained by adding an acid anhydride such as maleic anhydride to an esterified product modified with a fatty acid or the like are exemplified.

(3) As the polyether resin, for example, a resin obtained by polymerizing a bisphenol / epichlorohydrin type epoxy resin in the presence of a catalyst and adding a polycarboxylic acid or the like can be suitably used.

Among the above-mentioned resins (A), a coating film having excellent aesthetics and weather resistance can be obtained, and thus can be obtained by copolymerizing a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and if necessary, other monomers. Acrylic copolymers are particularly preferred.

Resin (A) generally has an acid number in the range of about 1 to about 100, preferably about 10 to about 80, and a hydroxyl value of about 10 to about 5,5.
It is desirably in the range of 000, preferably about 20-2,000. When the acid value is smaller than about 1, the ester bond is reduced in the cured coating film, and the weather resistance of the coating film is reduced.
If it is larger than 100, the storage stability of the coating and the water resistance of the coating film deteriorate, so that it is not very preferable. In addition, when the hydroxyl value is less than about 10, the curability of the coating film decreases, and the coating properties such as hardness and flex resistance tend to decrease.On the other hand, when the hydroxyl value exceeds about 5,000, the water resistance and corrosion resistance are reduced. It is not preferable because the coating film performance such as the above-mentioned deteriorates.

The resin (A) generally has a number average molecular weight of about 1,000 to
Preferably it is in the range of about 100,000, preferably in the range of about 2,000 to about 80,000, and has a softening point of less than 130C, preferably less than about 115C. If the number average molecular weight is less than about 1,000, the coating properties such as hardness, flex resistance, and corrosion resistance are likely to decrease,
On the other hand, when the number average molecular weight is more than about 100,000, the appearance of the coating film such as smoothness tends to be deteriorated. On the other hand, if the softening point is higher than about 130 ° C., the appearance of the coating film such as smoothness tends to deteriorate.

Resin (A) is, in addition to the above hydroxyl group and carboxyl group,
Functional groups such as a phenolic hydroxyl group and an alkoxysilane group (and a hydroxysilane group) can be introduced as necessary. The method for introducing these functional groups is not particularly limited, and a method known per se can be used,
For example, the introduction of a phenolic hydroxyl group uses bisphenol-modified (meth) acrylate as a monomer component of the vinyl resin, and the introduction of an alkoxysilane group (and a hydroxysilane group) uses γ-methacryloxypropyltrimethoxysilane and the like. Using a compound such as a hydrolyzate as a monomer component of the vinyl resin,
It can be carried out by copolymerization.

The epoxy compound (B) used in the coating composition (1) of the present invention is selected from an epoxy group on the alicyclic hydrocarbon ring and an epoxy group directly bonded to a carbon atom forming the alicyclic hydrocarbon ring. Having at least two or more epoxy groups in one molecule, and the alicyclic hydrocarbon ring may be a three-membered small ring to a seven-membered ring or more. The ring may be monocyclic or polycyclic, and the ring may constitute a bridged hydrocarbon ring. The epoxy group on the alicyclic hydrocarbon ring, for example, And an epoxy group directly bonded to a carbon atom forming an alicyclic hydrocarbon ring, for example, The group shown by these is mentioned.

As the epoxy resin (B), a commercially available epoxy resin can be used, and specific examples of such an epoxy resin include the following.

And other bifunctional epoxy resins.

In addition to the above [X in the above formula is Or -OR, wherein R is a _C1-36 monovalent or divalent hydrocarbon group, n is 0-100, and m is 5
100100, and p is 2-100.] An epoxy resin containing a unit such as
9667)), [In the formula, k is an integer of 0 to 15.] It is also possible to use a trifunctional or higher functional epoxy resin.

In combination with the epoxy compound (B), other epoxy resins having an epoxy group such as a glycidyl ether type epoxy polymer compound and an aliphatic internal epoxy polymer compound can also be used. The other epoxy resin is desirably used at a ratio of about 25% by weight or less based on the total amount of both, from the viewpoints of storage stability of the paint and curability of the coating film.

The epoxy resin (B) has an average of 2 epoxy groups in one molecule.
Or more, preferably 2 to 2000 on average, and more preferably 2 to 400 on average. If the number of epoxy groups is less than two on average, the curability of the coating film decreases, and the performance such as hardness, flex resistance, and corrosion resistance deteriorates.

The epoxy resin (B) also generally has a number average molecular weight in the range of about 100 to about 100,000, preferably about 110 to about 20,000, and has a softening point of about 130 ° C. or less, preferably about 1 to about 100 ° C.
It is preferably 15 ° C or lower. Those having a number average molecular weight of less than about 100 are difficult to obtain, while those having a number average molecular weight of more than about 100,000 are not preferred because of poor coated surface smoothness. If the softening point is higher than about 130 ° C., the smoothness of the coating film tends to deteriorate.

 The quaternary ammonium compound (C) has the general formula: [R¹R^TwoR^Three
R^FourN ] X Can be used.
In the above formula, R¹, R^Two, R^ThreeAnd R^FourRepresents a hydrocarbon group
However, they may be the same or different. Ma
The hydrocarbon group may be substituted with a hydroxy group.
No. X represents a halogen ion or an anionic residue of an acid;
For example, Cl, Br, F, I, SO_Four, HSO_Four, NO_Three, PO_Four, ClO_Four, H
COO, CH_ThreeCOO, OH and the like.

Specific examples of the quaternary ammonium compound (C) include, for example, tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, methyltriethylammonium chloride, tetramethylammonium bromide, tetraethylammonium fluoride, tetraethylammonium Tetraalkylammonium halides such as iodide; tetraalkylammonium organic acid salts such as tetramethylammonium acetate and tetraethylammonium formate; tetramethylammonium hydrogen sulfate, tetraethylammonium hydrogensulfate, tetramethylammonium nitrate, tetraethylammonium nitrate, Textiles such as tetraethylammonium chlorate and tetraethylammonium phosphate Laalkylammonium inorganic acid salt; tetramethylammonium hydroxide, tetraethylammonium hydroxy, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetraisoamylammonium hydroxide, tetradodecylammonium hydroxide, methyltriethylammonium Hydroxide, ethyltrimethylammonium hydroxide, tetradecyltrimethylammonium hydroxide, monohydroxyethyltrimethylammonium hydroxide, monohydroxyethyltriethylammonium hydroxide, dihydroxyethyldimethylammonium hydroxide, dihydroxyethyldiethylammonium hydroxide, trihydro Quaternary ammonium hydroxides such as silethylmonomethylammonium hydroxide, trihydroxyethylmonoethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, benzylmethyldiethylammonium hydroxide and cyclohexyltrimethylammonium hydroxide; No.

Among the above-mentioned quaternary ammonium compounds, quaternary ammonium hydroxide has the advantage that it gives a coating composition having excellent storage stability and can form a coating film having excellent water resistance, corrosion resistance and the like. And can be used in particular.

The polyepoxy compound (D) used in the coating composition (2) of the present invention is an alicyclic compound obtained by reacting an epoxy compound having a hydroxyl group and an epoxy group in an alicyclic hydrocarbon ring with a polyisocyanate compound. It is a polyepoxy compound.

The epoxy compound having a hydroxyl group and an epoxy group in an alicyclic hydrocarbon ring for obtaining the polyepoxy compound (D) is a compound having one hydroxyl group and one or more alicyclic epoxy groups in one molecule. The alicyclic epoxy group is an epoxy group on an alicyclic hydrocarbon ring, wherein the alicyclic hydrocarbon ring is a three-membered small ring to a seven-membered ring or more; The ring may be a single ring or a polycyclic ring, and the ring may form a bridged hydrocarbon ring. The hydroxyl group-containing alicyclic epoxy compound includes, for example, those represented by the following general formulas (1) to (7).

Wherein, R ⁴ represents a divalent hydrocarbon group of C _{1 to 20,} R ⁵
_Are the same or different, each represents a C _1-8 divalent hydrocarbon group, R ³ represents a hydrogen atom or a methyl group, q
Is an integer of 1 to 10.] In the above general formula, examples of the divalent hydrocarbon group include an alkylene group, a cyclic alkylene group, a phenylene group, and a substituted phenylene group. The alkylene group can be linear or branched, specifically
Examples of _{1 to 8} include methylene, ethylene, ethylethylene, propylene, butylene, pentamethylene,
Hexamethylene, etc. octamethylene and the like, also, those of C _{1 to 20,} for example, in addition to the above C _{1 to 8,} decane methylene, dodecane methylene, tetradecane methylene, etc. octadecane methylene and the like.

Preferred specific examples of the hydroxyl group-containing alicyclic epoxy compound represented by the above general formula include the following.

The polyisocyanate compound for obtaining the polyepoxy compound (D) by reacting with the hydroxyl group-containing alicyclic epoxy compound is a compound having two or more isocyanate groups in one molecule. Any type of polyisocyanate compound of a cyclic type, an aromatic type and an aromatic type-aliphatic type may be used, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate,
Aliphatic diisocyanate compounds such as decamethylene diisocyanate; alicyclic diisocyanate compounds such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenyl methane diisocyanate, and hydrogenated xylylene diisocyanate; aromatics such as tolylene diisocyanate and diphenyl methane diisocyanate Aromatic diisocyanate compounds; and aromatic-aliphatic diisocyanate compounds such as xylylene diisocyanate and tetramethyl xylylene diisocyanate. In addition to the above, the diisocyanate compound and a polyol (eg, ethylene glycol,
Adducts with trimethylolpropane, etc., and polyisocyanates such as the above-mentioned aliphatic diisocyanate compound or alicyclic diisocyanate compound, such as a biuret compound or an isocyanurate compound. Among these, aliphatic, alicyclic, and aromatic-aliphatic polyisocyanate compounds are preferably used because a coating film having little deterioration and excellent weather resistance can be obtained.

The reaction between the hydroxyl group-containing alicyclic epoxy compound and the polyisocyanate compound can be performed by a reaction between a hydroxyl group and an isocyanate group known per se, for example, a hydroxyl group-containing alicyclic epoxy compound and a polyisocyanate compound. In a nitrogen atmosphere until isocyanate groups are substantially freed, for example from room temperature to
The reaction can be carried out at a temperature of about 180 ° C. for about 10 minutes to about 24 hours. The above mixture can be used as an organic solvent solution dissolved or dispersed in an inert organic solvent such as an ester, ketone, ether, or aromatic hydrocarbon containing no active hydrogen. In the reaction, an organic metal such as dibutyltin laurate, dibutyltin-2-ethylhexoate, lead octenoate and zinc naphthenate can be blended as a reaction catalyst.

The mixing ratio of the hydroxyl group-containing alicyclic epoxy compound and the polyisocyanate compound is not strictly limited, but generally, the equivalent ratio of the hydroxyl group in the epoxy compound to the isocyanate group in the polyisocyanate compound is about
It is desirable to formulate in a range from 0.9 to about 1.1.

The epoxy compound (D) thus obtained has an average of 2 or more, preferably 2 to 2,000, more preferably 2 to 400 alicyclic epoxy groups in one molecule. When the number of epoxy groups is less than two on average, the curability of the coating film tends to decrease, and the coating film performance such as hardness, flex resistance and corrosion resistance tends to decrease.

The polyepoxy compound (D) has a number average molecular weight of about 200 to about 20,000, preferably about 300 to about 10,000, and has a softening point of about 130 ° C or lower, preferably a softening point of 115 ° C or lower. It is desirable to have. Number average molecular weight is about 200
Smaller ones are difficult to obtain industrially, while if the number average molecular weight is greater than about 20,000, the smoothness of the coated surface tends to decrease. When the softening point is higher than about 130 ° C., the smoothness of the coated surface tends to decrease.

Preferred specific examples of the polyepoxy compound (D) include the following.

Resin (A) used in coating composition (2) of the present invention and fourth resin
As the quaternary ammonium compound (C), the same compounds as those used in the coating composition (1) of the present invention can be used. The resin (A) desirably has the above-described range of the type, acid value, hydroxyl value, and number average molecular weight for the same reason as described for the coating composition (1) of the present invention. Further, as the quaternary ammonium compound (C), the coating composition of the present invention (1)
It is desirable to use quaternary ammonium hydroxy for the same reasons as described above.

In the present invention, the resin (A) and the epoxy compound (B) or (D) are generally about 40 to 97% by weight, preferably about 50 to about 95% by weight, more preferably about 50 to about 95% by weight in terms of the total weight of both. About 60 to about 90% by weight, epoxy compound (B) or (D) about 3 to about 60% by weight, preferably about 5 to about 60% by weight.
Preferably it is present in an amount of about 50% by weight, more preferably about 10 to about 40% by weight. If the ratio is out of the above range, the curability is lowered, and the coating properties such as water resistance, corrosion resistance, and bending resistance tend to be inferior. The epoxy compound (B) or (D) is the same as the epoxy compound (B)
Alternatively, the equivalent ratio (hydroxyl group / epoxy group) of the hydroxyl group in the resin (A) to the epoxy group in (D) is about 0.3 or more, preferably about 0.5 to about 5, more preferably about 0.7 to about 4. It is desirable to blend with the resin (A) so as to be within the range. When the corresponding ratio is less than about 0.3, the unreacted resin (A) component increases in the coating film, and the flex resistance, water resistance, There is a tendency that coating film performance such as corrosion resistance tends to decrease. The carboxyl group in the resin (A) is in the range of about 0.1 to about 1, preferably about 0.1 to about 0.6 in terms of the equivalent ratio of carboxyl group / epoxy group from the viewpoints of curability, water resistance of the coating film, corrosion resistance and the like. It is desirable to make

The quaternary ammonium compound (C) is generally used in an amount of about 0.01 to about 0.01 based on the total weight of the resin (A), the epoxy compound (B) or (D) and the quaternary ammonium compound (C).
10% by weight, preferably about 0.1 to about 7% by weight, more preferably 0.1 to 5% by weight.

The coating composition of the present invention is obtained by, for example, mixing the epoxy compound (B) or (D) with a solution in which the resin (A) is dissolved or dispersed in an organic solvent, or the epoxy compound (B).
Alternatively, it can be obtained by mixing a solution obtained by dissolving or dispersing (D) in an organic solvent, and then blending the resulting mixture with a quaternary ammonium compound (C). The organic solvent that can be used to dissolve or disperse the resin (A), the epoxy compound (B) or (D) is preferably an organic solvent in which these resins are substantially inert to organic functional groups. Specific examples thereof include alcohol solvents, ether solvents, ketone solvents, ester solvents, and hydrocarbon solvents.

In the coating composition of the present invention, for example, polytetramethylene glycol, bisphenol A
-Ethylene oxide adducts, polycaprolactone polyols, polycarbonate diols, polyurethane polyols, vinyl alcohol (co) polymers, styrene-allyl alcohol copolymers, and other polyol resins that do not contain carboxyl groups can also be blended. Further, for the purpose of curing the coating film at a lower temperature, a phenol compound (for example, catechol, etc.), a silanol compound (for example, diphenylsilanediol, etc.), a metal chelate compound (for example, Al, Ti, V, Fe, Zn, Zr) , A chelate of a metal such as Sn with a β-diketone such as ethyl acetoacetate, trifluoroacetylacetone or dibenzoylacetylacetone). The (co) catalyst is usually based on 100 parts by weight of the resin (A) and the epoxy compound (B) or (D).
Usually, it can be blended in the range of about 0.01 to about 10 parts by weight.

Further, the coating composition of the present invention may contain a coloring pigment (for example, titanium white, carbon black, red iron, etc.) and an extender pigment (for example, clay, talc, silica, etc.) as necessary.
And other paint additives (for example, a pigment dispersant, an anti-cissing agent, a fluidity adjusting agent, etc.) and the like.

The method for forming a coating film using the coating composition of the present invention is not particularly limited, and for example, is applied to a substrate surface by means such as electrodeposition coating, spray coating, dip coating, roller coating, and brush coating, followed by drying. Can be implemented. The coating film thickness is not particularly limited, but usually, a range of 10 to 100 μm seems to be sufficient. Drying of the coating is usually about 120 ° C
About 30 minutes, and at about 180 ° C. for about 10 minutes. The substrate to be applied is also not particularly limited, but is preferably steel, aluminum, alumite, copper, a steel steel having zinc, tin, chromium, aluminum, or the like coated on the surface of the steel, or a chromic acid or phosphoric acid on the steel surface. Can be applied to a wide range of metals such as those subjected to chemical treatment or electrolytic treatment.

[Examples] Next, the present invention will be described specifically with reference to examples, but the present invention is not limited thereto. “Parts” and “%” in Examples and Comparative Examples are based on weight.

Example 1 A four-necked flask was charged with 89 parts of methylpropanol.
Heat to 0 ° C. 3 parts of acrylic acid, 20 parts of hydroxyethyl acrylate, 57 parts of ethyl methacrylate
20 parts of the mixture and 2,2'-azobisisobutylnitrile 1
And a mixture of 10 parts of methyl isobutyl ketone is added dropwise over 1 hour. Aged for another 1.5 hours, acid value 23, hydroxyl value 9
7. EHPE with resin with number average molecular weight of about 20,000 and solid content of 50%
31.3 parts of an 80% EHPE-3150 solution obtained by dissolving 25 parts of -3150 (epoxidized polyvinylcyclohexene oxide, epoxy equivalent 190, average molecular weight about 1500; trade name of Daicel Chemical Industries, Ltd.) in 6.3 parts of methylpropanol, and further added. Then, 19.5 parts of a 20% methanol solution of tetraethylammonium hydroxide was added, stirred, and further diluted with xylol to obtain a clear paint having a solid content of 30%. The storage stability ^{(* 1)} of the obtained clear coating was not abnormal with the state of the coating and the performance of the coating. In addition, the clear paint before the storage test is spray-coated on a zinc phosphate-treated steel sheet so that the dry film thickness is about 20 μm, dried at 80 ° C for 10 minutes, and further dried at 120 ° C for 20 minutes to obtain a coated product. Was. The coating is smooth
^{(* 2)} good, salt spray ^{(* 3)} passed, pencil hardness ^{(* 4)} 2H, flex resistance ^{(* 5)} passed. Further, the gel fraction ^{(* 6)} of the coating film was 90%.

Example 2 4 parts of methacrylic acid, 25 parts of hydroxyethyl methacrylate, 10 parts of 2-ethylhexyl methacrylate, 10 parts of methyl methacrylate under the same conditions as in Example 1 except that the monomer components were all replaced by the following. 51
Parts, styrene 10 parts of acrylic resin of monomer composition was synthesized, acid value 26, hydroxyl value 108, number average molecular weight 25000, solid content
200 parts of a 50% resin were obtained. To this, 18.8 parts of 80% EHPE3150 was added (15 parts in solid content), and 16.2 parts of a 10% methanol solution of tetramethylammonium hydroxide was further added and stirred to obtain a 30% solid content clear paint. The storage stability ^{(* 1)} of the obtained clear paint was not abnormal in both the paint state and the film performance. Example 1 using clear paint before storage test
Coating and drying were performed in the same manner as in the above to obtain a coated product. The coated material has good coating smoothness ^{(* 2)} and salt spray resistance ^{(* 3)}
It passed the pencil hardness ^{(* 4)} 2H and the bending resistance ^{(* 5)} . Further, the gel fraction ^{(* 6)} of the coating film was 92%.

Example 3 200 parts of the 50% resin obtained in Example 1, 3,4-epoxycyclohexylcarboxymethylcyclohexene oxide 15
And a mixture of 17.9 parts of a 10% tetrabutylammonium hydroxymethanol solution and 2 parts of triethylamine were stirred and further diluted with xylol to obtain a clear paint having a solid content of 30%. The storage stability ^{(* 1)} of the obtained clear paint was not abnormal in both the paint state and the film performance. The clear paint before storage test was applied to zinc phosphate treated steel sheet with a dry film thickness of about 20.
It was spray-coated to a thickness of μm, dried at 80 ° C. for 10 minutes, and further dried at 140 ° C. for 20 minutes to obtain a coated product. The coated material has good coating smoothness ^{(* 2)} and salt spray resistance
^{(* 3)} pass, pencil hardness ^{(* 4)} 2H, flex resistance ^{(* 5)}
It passed. Furthermore, the gel fraction ^{(* 6)} of the coating film was 93%.

Example 4 A four-necked flask was charged with 89 parts of methylpropanol, and 11
Heat to 0 ° C. To this, a mixture of 2.7 parts of acrylic acid, 15 parts of hydroxyethyl acrylate, 67.3 parts of ethyl methacrylate, and 15 parts of styrene, and a mixture of 1 part of azoisobutyronitrile and 10 parts of methyl isobutyl ketone are dropped over 1 hour. After further aging for 1.5 hours, a resin having an acid value of 23, a hydroxyl value of 73, a number average molecular weight of about 25,000 and a solid content of 50% was obtained. Next, 14.5 parts by weight of duranate TPA-100 (trade name, manufactured by Asahi Kasei Corporation, isocyanurate of isocyanate of hexamethylene diisocyanate, trifunctional isocyanate, isocyanate equivalent: 185) and 3,4-epoxytetrahydrobenzyl alcohol (Daicel Chemical Industries, Ltd.) 10.5 parts of an epoxy equivalent (135), manufactured by Co., Ltd.) was reacted at 120 ° C. for 3 hours, and after confirming that the isocyanate value was 0, methylpropanol was added.
By adding 6.3 parts, an epoxy compound having a solid content of 80% and an epoxy equivalent of 325 was obtained. The base resin (200 parts), the epoxy compound (31.3 parts), and a 20% tetraethylammonium hydroxide methanol solution (19 parts) were sufficiently stirred, and further diluted with xylol to obtain a clear paint having a solid content of 30%. The storage stability ^{(* 1)} of the obtained clear paint was not abnormal in both the paint state and the coating film performance. In addition, the clear paint before storage test was applied to zinc phosphate treated steel
It was spray-coated to a thickness of μm, dried at 80 ° C. for 10 minutes, and further dried at 140 ° C. for 20 minutes to obtain a coated product. The coated material has good coating smoothness ^{(* 2)} and salt spray resistance
^{(* 3)} passed, pencil hardness ^{(* 4)} 3H, bending resistance ^{(* 5)}
It passed. The gel fraction ^{(* 6)} of the coating film was 99%.

Example 5 3 parts of methacrylic acid, 30 parts of hydroxyethyl methacrylate, 10 parts of 2-ethylhexyl methacrylate, 10 parts of methacrylic acid under the same conditions as in Example 4 except that the monomer components were all replaced by the following. Methyl 42
An acrylic resin having a monomer composition of 15 parts by weight and 15 parts by weight of styrene was synthesized to obtain a base resin having an acid value of 20, a hydroxyl value of 129, a number average molecular weight of 20,000 and a solid content of 50%. Next, IPDI-T1890100 (trade name, manufactured by Daicel Hyurs Co., Ltd., isocyanurate of isophorone diisocyanate, isocyanate equivalent 247) 17.
5 parts and 12.5 parts of Celloxide 4000 (trade name, manufactured by Daicel Chemical Industries, Ltd .; epoxy equivalent: 177) were reacted at 120 ° C. for 3 hours, and after confirming that the isocyanate value was 0, 7.5 parts of methylpropanol was added. Thus, an epoxy compound having a solid content of 80% and an epoxy equivalent of 425 was obtained. The base resin (200 parts), the epoxy compound (37.5 parts), and a 10% tetramethylammoniumhydroxyl methanol solution (16 parts) were added and stirred to obtain a 30% solids clear paint. The storage stability ^{(* 1)} of the obtained clear paint was not abnormal in both the paint state and the coating film performance. The clear paint before the storage test was applied and dried in the same manner as in Example 4 to obtain a coated product. The coated material has good coating smoothness ^{(* 2)} and salt spray resistance
^{(* 3)} pass, pencil hardness ^{(* 4)} 2H, flex resistance ^{(* 5)}
It passed. Furthermore, the gel fraction ^{(* 6)} of the coating film is 91%
Met.

Example 6 An adduct of 1 mol of 3,4-epoxytetrahydrobenzyl alcohol and 2 mol of ε-caprolactone (Epoxy equivalent: 360, manufactured by Daicel Chemical Industries, Ltd.) and 26.5 parts of duranate TPA ^ 100 (same as above) 13.5 The reaction was conducted at 120 ° C. for 3 hours, and after confirming that the isocyanate value was 0, 10 parts of methylpropanol was added to obtain an epoxy compound of epoxy 545 having a solid content of 80%. 50 parts of this epoxy compound, 200 parts of the 50% base resin of Example 1 and 18 parts of a 20% methanol solution of tetrabutylammonium hydroxide were sufficiently stirred, and further diluted with xylol to obtain a clear paint having a solid content of 30%. Storage stability of the obtained clear paint
^{(* 1)} showed no abnormality in both the paint state and the coating film performance. Spray the clear paint before storage test on zinc phosphate treated steel sheet so that the dry film thickness is about 20μm,
For 10 minutes, and further dried at 140 ° C. for 20 minutes to obtain a coated product. The coated product passed the coating film smoothness ^{(* 2)} , passed the salt spray resistance ^{(* 3),} passed the pencil hardness ^{(* 4)} H, and passed the bending resistance ^{(* 5)} . The gel fraction of the coating film ^{(* 6)}
Was 92%.

Comparative Example 1 42 parts of Cymel 303 (trade name, Mitsui Toatsu Co., Ltd., aminoaldehyde resin) and 231 parts of xylol were mixed with 200 parts of the 50% resin obtained in Example 1 to obtain a 30% solids clear paint. . The paint is applied to a zinc phosphate treated steel sheet with a dry film thickness of about 20 μm.
Spray paint at 80 ° C for 10 minutes, then 140
The coating was obtained by drying at 20 ° C for 20 minutes. The coated product was poor in coating smoothness ^{(* 2)} , failed in salt spray ^{(* 3),} failed in pencil hardness ^{(* 4)} 4B, and failed in bending resistance ^{(* 5)} .
The gel fraction ^{(* 6)} of the coating film was 70%.

( ^* 1) Storage stability: After standing at 30 ° C. for one month, the sedimentation and separation of the clear paint were visually observed. Further, the clear paint after storage was applied and dried, and the initial appearance of the paint film and the presence or absence of a decrease in paint film performance (such as salt spray resistance, bending resistance, and pencil hardness) were examined.

( ^* 2) Coating smoothness: The surface unevenness of the coating film was visually observed.

( ^* 3) Salt spray resistance: Tested in accordance with JIS2-2371, and those with a creep width within 2 mm on one side from the cut portion of the coating film were accepted. The test time was 1000 hours.

( ^* 4) Pencil hardness: Tested in accordance with JISK-5400.

( ^* 5) Bending resistance: The test plate is bent at a right angle in 1 to 2 seconds in an atmosphere at a temperature of 20 ° C. Peeling of the coating film at the bent part,
Those that had no abnormalities such as cracks were accepted.

( ^* 6) Gel fraction: 300 peeled off dried coating film
After being placed in a mesh stainless steel mesh reticulated container and extracted with a Soxhlet extractor using an acetone / methanol = 1/1 solvent at reflux temperature for 6 hours, the gel fraction was calculated according to the following equation.

Gel fraction (%) = (coating weight after extraction / coating weight before extraction) × 100

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Motoshi Yabuta 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside Kansai Paint Co., Ltd. (72) Yoshio Sasaki 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai JP-A-4-15278 (JP, A) JP-A-4-15279 (JP, A) JP-A-52-81345 (JP, A) JP-A-2-281024 (JP) (A) JP-A-1-118574 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 163/00-163/10 C09D 201/06-201/08 C08G 59/20 C08G 59/40

Claims (3)

(57) [Claims] 1. A resin (A) having a hydroxyl group and a carboxyl group, and one molecule of an epoxy group on an alicyclic hydrocarbon ring and / or an epoxy group directly bonded to a carbon atom forming an alicyclic hydrocarbon ring. An organic solvent-type thermosetting coating composition comprising, as essential components, an epoxy compound (B) having an average of two or more compounds therein and a quaternary ammonium compound (C). 2. An alicyclic polyepoxy compound obtained by reacting a resin (A) having a hydroxyl group and a carboxyl group, an epoxy compound having an epoxy group on a hydroxyl group and an alicyclic hydrocarbon ring with a polyisocyanate compound. An organic solvent type thermosetting coating composition comprising (D) and a quaternary ammonium compound (C) as essential components. 3. The organic solvent type thermosetting coating composition according to claim 1, wherein the quaternary ammonium compound (C) is a quaternary ammonium hydroxide.