JP2000204291A - Acryl/polyester hybrid resin composition for powder coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for powder coating which is improved in durability, external appearance, thermal curabilty, impact resistance, adhesive ness, and weatherability by incorporating a specific silylated vinyl copolymer and a polyester resin into the same. SOLUTION: A silylated vinyl copolymer (A) having silyl groups represented by the formula as the main crosslinking groups and having a glass transition point of 40-100 deg.C and a number average mol.wt. of 2,000-20,000 is compounded with a polyester resin (B) having a number average mol.wt. of 2,000-20,000 in a molar ratio of the glycidyl group of ingredient A to the carboxyl group of ingredient B of (1/3)-(3/1), preferably (1/2)-(2/1). In the formula, R1 is a 1-10C alkyl, 6-10C aryl, or 7-10C aralkyl; X is H, a halogen, hydroxy, alkoxy, phenoxy, thioalkoxy, acyloxy, aminoxy, ketoximate, amino, amido or alkenyloxy; and (a) is 0-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition for powder coatings. More specifically, for example, relates to a resin composition for powder coatings suitably used for automotive parts, industrial machinery, steel furniture, building interior and exterior, home appliances and the like, and more specifically, excellent durability, appearance, heat Curability, impact resistance,
The present invention relates to a resin composition for a powder coating which exhibits excellent adhesion and the like and extremely excellent weather resistance.

[0002]

2. Description of the Related Art Conventionally, for painting automotive parts, industrial machines, steel furniture, interior and exterior of buildings, home electric appliances, etc., acid-
A paint mainly containing an ester resin or an epoxy resin by epoxy crosslinking is used. However, although the paint is relatively inexpensive, there is a problem that the weather resistance is extremely reduced when used outdoors.

As a paint having excellent weather resistance outdoors, there is a paint using a fluorine resin. However, in this case, the cost jumps greatly and is not practical.

[0004] In addition, since the influence on the global environment is regarded as important, solvent-based paints are being shunned by the generation of a large amount of volatile components, and it is necessary to replace solvent-based paints with powder paints.

[0005] Polyester resins, which are often used in powder coatings, have a good balance of coating film properties, but have insufficient weather resistance. On the other hand, an acrylic resin is used to improve weather resistance, but a physical property balance as high as that of a polyester resin cannot be obtained. Acrylic resins tend to be harder and more brittle than polyester resins, and their mechanical properties and the like are inferior to polyester resins. Until now, it has been difficult to achieve both adhesion and impact resistance while maintaining weather resistance.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an ester resin or an epoxy resin by the above-mentioned acid-epoxy crosslinking which has been frequently used. Overcoming the shortcomings of resin, not only has excellent weather resistance, but also clears environmental issues,
It is another object of the present invention to provide a powder coating having a new crosslinking type, which can be manufactured at low cost. By using the method of the present invention, it is possible to obtain a coating film having mechanical properties that cannot be realized with a conventional acrylic resin, and having excellent adhesion and impact resistance while maintaining high weather resistance.

[0007]

SUMMARY OF THE INVENTION The present invention provides a novel resin composition having the following constitution, thereby achieving the above object. 1) The vinyl copolymer (A) containing a silyl group represented by the following general formula (1) and the polyester resin (B) are essential components, and the component (A) is represented by the following general formula (1). The main group is a silyl group to be crosslinked, the glass transition temperature is 40 to 100 ° C, and the number average molecular weight is 2000 to 2000.
0, the component (B) has a crosslinkable functional group,
A resin composition for powder coatings, which has a glass transition temperature of 40 to 100 ° C and a number average molecular weight of 2000 to 20,000.

[0008]

Embedded image (Wherein R ¹ is an alkyl group having 1 to 10 carbon atoms, 6 carbon atoms)
And at least one group selected from the group consisting of an aryl group having 10 to 10 and an aralkyl group having 7 to 10 carbon atoms, and when there are a plurality of groups, they may be the same or different. X is at least one member selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, a phenoxy group, a thioalkoxy group, an acyloxy group, an aminoxy group, a ketoximate group, an amino group, an amide group, and an alkenyloxy group. Group, and when there are a plurality of groups, they may be the same or different. a is an integer of 0 to 2. 2) The composition contains a crosslinkable and curable polymer other than the component (A), and the component (A) accounts for 20% by weight or more and less than 100% by weight of the total of the component (A) and the polymer as a whole. Characteristic resin compositions for powder coatings. 3) The resin composition for powder coatings, wherein the component (A) contains a glycidyl group, the component (B) contains a carboxyl group, and contains an aliphatic dibasic acid (C). 4) The component (A) and the component (B) each contain a hydroxyl group, and a compound (D) having a blocked isocyanate and / or a uretdione structure is used as a curing agent. The resin composition for a powder coating according to claim 1. 5) A resin composition for powder coatings, wherein 0.001 to 10 parts by weight of a curing catalyst (E) is added to 100 parts by weight of the component (A).

The copolymer of the component (A) is usually produced using a silyl group-containing vinyl monomer (a) represented by the general formula (1).

It contains a silyl group represented by the general formula (1).
The vinyl monomer (a) is a vinyl monomer represented by the general formula (1):
There is no particular limitation as long as it has a lyl group._Two=
CHSi (OCH_Three)_Three, CH_Two= CHSi (CH_Three) (O
CH_Three)_Two, CH_Two= C (CH_Three) Si (OCH_Three)_Three, CH
2 = C (CH_Three) Si (CH_Three) (OCH_Three)_Two, CH_Two=
CHSi (OC_TwoH_Five)_Three, CH_Two= CHSi (OC_ThreeH₇)
_Three, CH_Two= CHSi (OC_FourH₉)_Three, CH_Two= CHSi
(OC₆H₁₃)_Three, CH_Two= CHSi (OC₈H₁₇) _Three, C
H_Two= CHSi (OC_TenH_{twenty one})_Three, CH_Two= CHSi (O
C₁₂H_{twenty five})_Three, CH_Two= CHCOO (CH_Two)_ThreeSi (OC
H_Three)_Three, CH_Two= CHCOO (CH_Two)_ThreeSi (CH_Three)
(OCH_Three)_Two, CH_Two= C (CH_Three) COO (CH_Two)_ThreeS
i (OCH_Three) _Three, CH_Two= C (CH_Three) COO (CH_Two)_Three
Si (CH_Three) (OCH_Three)_Two, CH_Two= CHCOO (CH
_Two)_ThreeSi (OC_TwoH_Five)_Three, CH_Two= CHCOO (CH_Two)_Three
Si (CH_Three) (OC_TwoH_Five)_Two, CH_Two= C (CH_Three) CO
O (CH_Two)_ThreeSi (OC_TwoH_Five) _Three, CH_Two= C (CH_Three)
COO (CH_Two)_ThreeSi (CH_Three) (OC_TwoH_Five)_Two, CH_Two
= CHCOO (CH_Two)_ThreeSi (OCH_TwoCH_TwoOC
H_Three)_Three, CH_Two= CHCOO (CH_Two)_ThreeSi (CH_Three)
(OCH_TwoCH_TwoOCH_Three)_Two, CH_Two= C (CH_Three) COO
(CH_Two)_ThreeSi (OCH_TwoCH_TwoOCH_Three)_Three, CH_Two= C
(CH_Three) COO (CH_Two)_ThreeSi (CH_Three) (OCH_TwoC
H_TwoOCH_Three)_Two, CH_Two= C (CH_Three) COO (CH_Two) _Two
O (CH_Two)_ThreeSi (OCH_Three)_Three, CH_Two= C (CH_Three) C
OO (CH_Two)_TwoO (CH_Two)_ThreeSi (CH_Three) (OCH_Three)
_Two, CH_Two= C (CH_Three) COO (CH_Two)₁₁Si (OCH
_Three)_Three, CH_Two= C (CH_Three) COO (CH_Two)₁₁Si (C
H_Three) (OCH_Three)_Two, CH_Two= CHCH_TwoOCO (ort
-C₆H_Four) COO (CH_Two)_ThreeSi (OCH_Three)_Three, CH_Two
= CHCH_TwoOCO (ort-C₆H_Four) COO (CH_Two)
_ThreeSi (CH_Three) (OCH_Three)_Two, CH_Two= CH (CH_Two)_Four
Si (OCH_Three)_Three, CH_Two= CH (CH_Two)₈Si (OC
H_Three)_Three, CH_Two= CHO (CH_Two)_ThreeSi (OCH_Three)_Three,
CH_Two= CHCH_TwoO (CH_Two)_ThreeSi (OCH_Three)_Three, CH
_Two= CHCH_TwoOCO (CH_Two) _TenSi (OCH_Three)_Three, C
H_Two= CH (para-C₆H_Four) Si (OCH_Three)_Three, C
H_Two= CH (para-C₆H_Four) Si (CH_Three) (OCH
_Three)_Two, CH_Two= C (CH_Three) (Para-C₆H_Four) Si
(OCH_Three)_Three, CH_Two= C (CH_Three) (Para-C
₆H_Four) Si (CH_Three) (OCH_Three)_TwoSuch as alkoxy
Ryl group-containing monomer; CH_Two= CHCOO (CH_Two)_ThreeSi
(CH_Three) Cl_Two, CH_Two= CHCOO (CH_Two)_ThreeSiC
l_Three, CH_Two= C (CH_Three) COO (CH_Two)_ThreeSi (C
H_Three)_TwoCl, CH_Two= C (CH_Three) COO (CH_Two)_ThreeSi
(CH_Three) Cl_Two, CH_Two= C (CH_Three) COO (CH_Two)_Three
SiCl_ThreeHalosilyl group-containing monomers such as CH;_Two= C
(CH_Three) COO (CH_Two)_ThreeSi (OH)_Three, CH_Two= C
(CH_Three) COO (CH_Two)_ThreeSi (CH_Three) (OH)_TwoWhat
Which silanol group-containing monomer; CH_Two= C (CH_Three) CO
O (CH_Two) _ThreeSi (OCOCH_Three)_ThreeSuch as acetoxy
Ryl group-containing monomers are exemplified.

Among these, alkoxysilyl group-containing monomers are particularly preferred in view of cost and stability. For example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane At least one selected from the group consisting of ethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, and 3- (meth) acryloxypropylmethyldiethoxysilane, or a mixture of two or more of these. . One or more of these silyl group-containing vinyl monomers may be used in combination, and 1 to 30 parts by weight based on 100 parts by weight of the vinyl copolymer containing the silyl group-containing vinyl monomer. Partially copolymerized. The copolymer is preferably copolymerized in an amount of preferably 2 to 25 parts by weight, more preferably 5 to 23 parts by weight. When the amount of copolymerizing the silyl group-containing vinyl monomer is 1
If less than 10 parts by weight, the curing properties of the resin composition, the mechanical strength of the coating film, the durability is inferior, if more than 30 parts by weight,
The storage stability of the resin decreases.

The other copolymerizable vinyl monomers of the component (b) are not particularly limited, and include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, isobutyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, 2-cyclohexylethyl (meth) acrylate, benzyl (meth)
Acrylate, 2-phenylethyl (meth) acrylate, benzyloxymethyl (meth) acrylate, 2-
Vinyl monomers such as benzyloxyethyl (meth) acrylate, phenoxymethyl (meth) acrylate, and 2-phenoxyethyl (meth) acrylate; styrene,
Aromatic hydrocarbon vinyl monomers such as α-methylstyrene, chlorostyrene, 4-hydroxystyrene and vinyltoluene; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid Acid having a polymerizable carbon-carbon double bond, such as α, β-ethylenically unsaturated carboxylic acid such as fumaric acid, citraconic acid, etc .; styrenesulfonic acid, vinylsulfonic acid; or salts thereof (alkali metal salts) , Ammonium salts,
Amine anhydrides, etc.); acid anhydrides such as maleic anhydride or half esters thereof with linear or branched alcohols having 1 to 20 carbon atoms; dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylamino (Meth) acrylate having an amino group such as ethyl (meth) acrylate; (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, Acryloyl morpholine or hydrochloric acid and acetate thereof; vinyl ester and allyl ester compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl monomers containing a nitrile group such as (meth) acrylonitrile;
-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, hydroxystyrene, 2-hydroxy-3-phenoxypropyl acrylate (Toa Gosei Chemical Co., Ltd.)
(Trade name: Aronix M-5700), hydroxyl-containing vinyl monomers such as hydroxyl-containing vinyl-modified hydroxyalkylvinyl monomers; glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, allyl glycidyl Glycidyl group-containing vinyl monomers such as ethers; α, β-ethylenically unsaturated carboxylic acid hydroxyalkyl esters such as (meth) acrylic acid hydroxyalkyl esters and phosphate ester group-containing vinyl compounds or urethanes Vinyl compounds such as (meth) acrylates containing a bond or a siloxane bond; AS-
6, methacryloyl group-containing macromonomers such as AN-6, AA-6, AB-6, and AK-5 (all manufactured by Toa Gosei Chemical Co., Ltd.); vinyl methyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, Other vinyl monomers such as butadiene and N-vinylimidazole are exemplified.

Of these 99 to 70 parts by weight of the component (b), a vinyl monomer having a glycidyl group can be contained, and preferably 5 to 50 parts by weight. More preferably, 7 to 40 parts by weight, and even more preferably, 9 to 30 parts by weight is copolymerized. There is no particular limitation on these glycidyl group-containing vinyl monomers, and at least one selected from the group consisting of glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, allyl glycidyl ether, and the like, or Mixtures of two or more are mentioned.

In addition, of 99 to 70 parts by weight of the component (b), a vinyl monomer having a hydroxyl group can be contained, and preferably 1 to 20 parts by weight. More preferably, 2 to 18 parts by weight, and even more preferably, 5 to 15 parts by weight is copolymerized.

There is no particular limitation on these vinyl monomers having a hydroxyl group, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-
Hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as hydroxyhexyl (meth) acrylate and 8-hydroxyoctyl (meth) acrylate; PlacelFA-1, PlacelFA-
4, PlacelFM-1, PlacelFM-4
Ε-caprolactone-modified hydroxyethyl (meth) acrylates (all manufactured by Daicel Chemical Co., Ltd.);
Polyalkylene glycol monomethacrylates such as Blemmer PP series and Blemmer PE series, polyethylene glycol polypropylene glycol monomethacrylates such as Blemmer PEP series, polyethylene glycol monoacrylates such as Blemmer AP-400 and Blemmer AE-350, Blemmer NKH-5050 (Glycerol monomethacrylate)
Alkylene oxide-modified (meth) acrylates (all manufactured by NOF Corporation).

The copolymer of the component (A) has a silyl group represented by the general formula (1) as a crosslinkable group. The silyl group is a main crosslinkable group having a function of crosslinking between molecules, and the component (A) may have another crosslinkable group such as a glycidyl group or a hydroxyl group as described above, if desired.

In the copolymer (A), the number of silyl groups is preferably 50% or more, more preferably 70% or more, and more preferably 80% or more, based on the total number of crosslinkable groups. It is particularly preferable that the above is satisfied.

As the method for producing the component (A), known polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization and the like can be used. Particularly, from the viewpoint of ease of synthesis, peroxides, azo compounds and the like can be used. Solution polymerization using a radical initiator is preferred.

The polymerization solvent used in the solution polymerization includes hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.), acetates (ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, etc.).
Non-reactive solvents such as isopropanol, n-butanol, ethers (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone, acetone, etc.) If so, there is no particular limitation.

Examples of the initiator used in the solution polymerization include organic peroxides such as benzoyl peroxide and tert-butyl peroxide, 2,2'-azobisisobutyronitrile,
2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropionitrile), 2,2′-azobis (2-methylbutyronitrile) and the like There is no particular limitation as long as it is a radical initiator such as an azo compound.

In the above solution polymerization, if necessary, n
-Dodecyl mercaptan, t-dodecyl mercaptan,
n-octyl mercaptan, n-octadecyl mercap
Tan, 3-mercaptopropyltrimethoxysilane, 3
-Mercaptopropyltriethoxysilane, 3-merca
Ptopropylmethyldimethoxysilane, 3-mercapto
Propylmethyldiethoxysilane, (H_ThreeCO)_ThreeSi-
SS-Si (OCH _Three)_Three, (H_ThreeCO)_ThreeSi-S₆−
Si (OCH_Three)_ThreeAdjust the molecular weight using a chain transfer agent such as
Can be knotted. In particular, an alkoxysilyl group
Chain transfer agent, such as 3-mercaptopropion
With the use of rutrimethoxysilane, silyl group-containing acrylic
Introducing an alkoxysilyl group at the end of the copolymer
Can be.

In the above solution polymerization, a predetermined amount of the above-mentioned monomers, initiator, chain transfer agent and the like are added to a polymerization solvent, polymerization is carried out, and the solvent is removed under reduced pressure. A) The component is obtained.

The number average molecular weight of the component (A) is from 2000 to 2000.
20000 is preferable, and 3000 to 10 is more preferable.
000. When the molecular weight is less than 2,000, it is difficult for the coating film to exhibit sufficient mechanical properties, and when it is more than 20,000, there is a problem that the coating film has poor smoothness. Further, the glass transition temperature of the component (A) is preferably from 40 to 100 ° C, more preferably from 50 to 100 ° C.
８０80 ° C. When the temperature is lower than 40 ° C., the storage stability of the powder coating material is poor. On the other hand, when the temperature is higher than 100 ° C., the smoothness of the coating film is poor. The polyester resin of the component (B) is not particularly limited, and a commercially available polyester resin for powder coating may be used, or may be produced as needed. The production may be performed by a known method. In addition, when a polyester resin containing a silyl group represented by the general formula (1) with the component (B) is produced, a known technique may be used. For example, a method in which a polyester resin having a hydroxyl group at a molecular chain terminal is used to react an isocyanate compound containing a silyl group represented by the general formula (1), or a polyester resin having a hydroxyl group at a molecular chain terminal is used, and an alkenyl is used at a terminal. Or by synthesizing a polyester resin having an alkenyl group at the molecular chain terminal, and introducing a silane compound having a silyl group represented by the general formula (1) by a hydrosilylation reaction. I just need.

The polyester resin having a carboxyl group and / or a hydroxyl group is not particularly limited, but is preferably a resin mainly composed of terephthalic acid and / or isophthalic acid and neopentyl glycol from the viewpoint of weather resistance. Specific examples of polyvalent carboxylic acids include, for example, terephthalic acid,
Isophthalic acid, phthalic acid, methylphthalic acid, methylterephthalic acid, trimellitic acid, pyromellitic acid, hemi-mellitic acid, benzophenone-3,3 ', 4,4'-tetracarboxylic acid, adipic acid, suberic acid, azelaic acid,
Sebacic acid, succinic acid, maleic acid, fumaric acid, 2,6
-Naphthalenedicarboxylic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,2,3-propanetricarboxylic acid, 6
And polycarboxylic acids such as -methylcyclohex-4-ene-1,2,3-tricarboxylic acid, acid anhydrides thereof, and mixtures of two or more thereof. If necessary, a monobasic acid such as benzoic acid or p-tert-butylbenzoic acid as a molecular weight modifier may be used in combination.

Specific examples of polyhydric alcohols include, for example, ethylene glycol, propylene glycol, 1,
3-butanediol, 1,4-butanediol, 1,6
-Hexanediol, isopentyl glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, bishydroxyethyl terephthalate, hydrogenated bisphenol A, ethylene oxide adduct or propylene oxide adduct of hydrogenated bisphenol A, trimethylolethane, trimethylol Propane, trimethyloloctane, glycerin, erythritol, pentaerythritol, 2,2,4-trimethylpentane-1,3-
Examples thereof include diol, cyclohexanediol, and a mixture of two or more thereof.

The method for producing the polyester resin includes known methods, for example, methods such as an esterification reaction and a transesterification reaction. The isocyanate compound used for introducing the silyl group represented by the general formula (1) into the polyester resin is not particularly limited as long as it has both the silyl group represented by the general formula (1) and the isocyanate group. 2-isocyanatoethyltrimethoxysilane, 2-isocyanatoethylmethyldimethoxysilane, 2-isocyanatoethyltriethoxysilane, 2
-Isocyanatoethylmethyldiethoxysilane, 3-
Isocyanate propyl trimethoxy silane, 3-isocyanate propyl methyl dimethoxy silane, 3-isocyanate propyl triethoxy silane, 3-isocyanate propyl methyl diethoxy silane, and the like. The method for introducing the silyl group represented by the general formula (1) via the alkenyl group-containing polyester resin is not particularly limited, but a hydrosilylation reaction is used from the viewpoint of reaction efficiency and easiness. The method is preferred. The silane compound used for the hydrosilylation reaction is not particularly limited, and for example, trimethoxysilane, methyldimethoxysilane, triethoxysilane, methyldiethoxysilane, tris (methoxymethoxy) silane, methyl-bis (methoxymethoxy)- Silane, tris (methoxyethoxy) silane, methyl-bis (methoxyethoxy)-
Examples include alkoxysilanes such as silane. Examples of the hydrosilylation catalyst include a simple substance of platinum, alumina, silica, carbon black, and the like, on which solid platinum is supported, chloroplatinic acid, a complex of chloroplatinic acid with alcohol, aldehyde, ketone, etc., a platinum-olefin complex platinum - vinylsiloxane complex, a platinum - phosphine complex, a platinum - phosphite complex, dicarbonyl dichloroplatinum, platinum catalysts such as platinum alcoholate, Rh (PPh _3), R
hCl ₃ , RhAl ₂ O ₃ , RuCl ₃ , IrCl ₃ , Fe
Cl ₃ , AlCl ₃ , PdCl ₂ .2H ₂ O, NiCl ₂ ,
Such as TiCl ₄ and the like, these catalysts may be used alone, it may be used in combination.

The method for introducing an alkenyl group into a hydroxyl-terminated polyester resin is not particularly limited, and is an alkenyl group-containing isocyanate such as allyl isocyanate, 2-isocyanatoethyl (meth) acrylate, or 3-isocyanatopropyl (meth) acrylate. Compound,
Allyl bromide, allyl chloride, 4-bromo-1
-Butene, 4-chloro-1-butene, 6-bromo-1-
Hexene, 6-chloro-1-hexene, 8-bromo-1
And alkenyl group-containing halogen compounds such as 8-octene and 8-chloro-1-octene, and acid halides such as acrylic acid bromide and acrylic acid chloride.

When synthesizing a polyester resin, the method of introducing an allyl group at the terminal includes allyl acetic acid,
Alkenyl group-containing monobasic acids such as (meth) acrylic acid, 2-butenoic acid and 3-butenoic acid, vinyl alcohol,
Allyl alcohol, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 6-hepten-1-ol, 7-octen-1-ol, 8-
Nonen-1-ol, 9-decene-1-ol, 2-
Examples include a method using an alkenyl group-containing monoalcohol such as (allyloxy) ethanol and neopentyl glycol monoallyl ether.

The number average molecular weight of the component (B) is 200
0 to 20000, preferably 3000 to 1000
0. When the molecular weight is less than 2,000, it is difficult for the coating film to exhibit sufficient mechanical properties, and when it exceeds 20,000, there is a problem that the coating film has poor smoothness. Further, the glass transition temperature of the component (B) is
It is 40-100 degreeC, Preferably it is 50-80 degreeC. When the temperature is lower than 40 ° C., the storage stability of the powder coating material is poor. On the other hand, when the temperature is higher than 100 ° C., the smoothness of the coating film is poor.

The copolymer of the component (A) is a copolymer which forms a siloxane bond by the action of moisture and can be crosslinked and cured. In addition, the component (B) reacts with a glycidyl group or a hydroxyl group contained in the component (A) and can be crosslinked and cured. In the present invention, only the components (A) and (B) may be used. Further, another crosslinkable polymer such as an epoxy resin or a silicone resin may be used in combination. When another crosslinkable curable polymer is used in combination, the component (A) is preferably used in an amount of 20% by weight or more of the crosslinkable curable copolymer, preferably 30% by weight, more preferably 50% by weight, and more preferably 80% by weight. % Is particularly preferable.

The aliphatic dibasic acid of the component (C) is not particularly limited as long as it is a compound represented by the general formula (2). For example, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid Etc., but sebacic acid, in view of the balance of various physical properties such as storage stability and mechanical strength,
Dodecane diacid is preferred.

The aliphatic dibasic acid of the component (C) is used in an amount of 1 to 100 parts by weight based on the components (A) and (B).
20 parts by weight are used, preferably 2 to 18 parts by weight, more preferably 3 to 15 parts by weight. (C)
When the use amount of the component is less than 1 part by weight, the mechanical properties are inferior because the amount of crosslinking of the acid-epoxy is small, and
If the amount is larger than parts by weight, the amount of the aliphatic dibasic acid used increases, so that the smoothness and the storage stability decrease.

The ratio of the number of glycidyl groups in the component (A) to the number of carboxyl groups in the components (B) and (C) is preferably 1: 3 to 3: 1. : 2 to 2: 1. In the composition, the carboxyl group in the component (B) can serve as a catalyst for hydrolysis / condensation of the silyl group represented by the general formula (1), and thus the cross-linking of the silyl group represented by the general formula (1) is performed. And acid-epoxy crosslinking occur simultaneously, but a curing catalyst (E) can be added to promote the crosslinking of the silyl group more smoothly.

The component (D) is not particularly limited as long as it is a compound having a blocked isocyanate group and / or a uretdione structure. Are preferably two or more. As specific examples, for example, (poly) isocyanate such as isophorone diisocyanate, trimethylhexamethylene diisocyanate, hexyl diisocyanate, isophorone diisocyanate and / or hexyl diisocyanate can be converted to ε-caprolactam, methyl ethyl ketone oxime, 1,2-pyrazole, 1,2,4 -Triazole,
Diisopropylamine, 3,5-dimethylpyrazole,
Blocked isocyanate obtained by reacting with diethyl malonate, a compound having a uretdione structure represented by the general formula (2) and the like are mentioned.

The component (C) is preferably used in an amount of 1 to 30 parts by weight, more preferably 2 to 25 parts by weight, based on 100 parts by weight of the components (A) and (B).

The ratio of the number of hydroxyl groups in the components (A) and (B) to the number of isocyanate groups in the component (D) is preferably 1: 3 to 3: 1, and more preferably 1: 3. A range of 2-2: 1 is preferred.

The curing catalyst (E) is not particularly limited as long as it promotes the hydrolysis reaction of the silyl group represented by the general formula (1) of the component (A) and can promptly cause a condensation reaction. It can be used, and examples thereof include organic sulfonic acid, a mixture or a reaction product of an organic sulfonic acid and a nitrogen-containing compound, phosphoric acid or phosphoric acid esters, and an organic metal compound.

Specific examples of the curing catalyst include, for example, dodecylbenzenesulfonic acid, p-toluenesulfonic acid,
Organic sulfonic acid compounds such as -naphthalenesulfonic acid and 2-naphthalenesulfonic acid; the organic sulfonic acid compounds and nitrogen-containing compounds (for example, 1-amino-2-propanol, monoethanolamine, diethanolamine,
-(Methylamino) ethanol, 2-dimethylethanolamine, 2-amino-2-methyl-1-propanol, diisopropanolamine, 3-aminopropanol, 2-methylamino-2-methylpropanol, morpholine, oxazolidine, 4, Mixtures or reactants with 4-dimethyloxazolidine, 3,4,4-trimethyloxazolidine, etc .; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monododecyl phosphate, dimethyl phosphate, diethyl phosphate,
Phosphoric acid or phosphate such as dibutyl phosphate, dioctyl phosphate, didodecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, 3-glycidoxypropyltrimethoxysilane, 3-glycid Epoxy compounds such as xypropyltriethoxysilane, 3-glycidoxypropyltrimethyldimethoxysilane, Cardura E manufactured by Yuka Shell Epoxy, Epicoat 828 and Epicoat 1001 manufactured by Yuka Shell Epoxy, and phosphoric acid and / or phosphoric acid. Or an addition reaction product with a monophosphate; hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine, DABC
Amines such as O, DBU, morpholine and diisopropanolamine; reactants of these amines with acidic phosphate esters; alkaline compounds such as sodium hydroxide and potassium hydroxide; benzyltriethylammonium chloride or bromide, tetrabutylammonium Quaternary ammonium salts such as chloride or bromide, and phosphonium salts; divalent tin compounds such as tin octylate and tin stearate, dibutyltin dioctoate,
Dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetylacetonate, dibutyltin bistriethoxysilicate, dibutyltin distearate, dibutyltin compounds such as dibutyltin malate, dioctyltin diversate, dioctyltin dilaurate, dioctyltin distearate, dioctyltin malate And the like; tetravalent organic tin compounds such as dioctyltin compounds; organic titanate compounds; organic aluminum compounds; and organic zirconium compounds.

Of these, organic titanate compounds and organic zirconium compounds are preferred from the viewpoint of curability during baking.

These curing catalysts may be used alone or in combination.

The amount of these curing catalysts used is (A) Component 1
The amount is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, based on 00 parts by weight. If the amount is more than 10 parts by weight, problems such as lack of storage stability and deterioration of the appearance of the coating film occur.

The resin composition for powder coatings may be, if necessary, a resin such as polyester, epoxy or acrylic, an inorganic pigment such as titanium dioxide, carbon black, iron oxide or chromium oxide, or a phthalocyanine or quinacdrine type. Additives such as organic pigments, coloring aids, spreading agents and defoamers, ultraviolet absorbers, antistatic agents and antiblocking agents can be added. The mixing ratio of these additives can be appropriately selected according to the required characteristics, and they can be used as a mixture.

The powder coating is prepared by using a melt kneader such as a heating roll or a kneader, cooling, and then pulverizing. Or, in the solution after polymerization of the vinyl copolymer,
A method in which a curing catalyst, a pigment, an additive, and the like are added and mixed, followed by spray drying can also be used.

The powder coating obtained in this manner is applied to a substrate by a known method such as electrostatic coating or fluid immersion coating. The thickness of the coating film can be appropriately selected as needed, and is usually 20 to 200 μm, preferably 40 to 150 μm.
μm is good. When the thickness is less than 20 μm, the coating film tends to be uneven, and when the thickness is more than 200 μm, there is a problem that the coating film tends to have irregularities.

The obtained coating material is usually at 150 to 220 ° C.
By baking at a temperature of about 5 minutes to 1 hour, it can be sufficiently cured, and a cured product (coating film) having excellent physical properties such as weather resistance and acid resistance can be formed. Fifteen
If the temperature is lower than 0 ° C or shorter than 5 minutes, the coating film is not sufficiently cured. If the temperature is higher than 220 ° C or longer than 1 hour, workability deteriorates and costs such as utility costs increase. Problem arises.

The composition of the present invention is used, for example, for building interiors and exteriors such as aluminum siding and fences, road materials such as guardrails, and home appliances such as air conditioners and refrigerators.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In addition, the part shown below shall show a weight part unless there is particular notice. The analysis values, characteristic values, and performance of the coating film in the examples were measured or evaluated by the following methods. Analytical values (1) Number average molecular weight of polymer Measured by gel permeation chromatography (GPC). Using a Waters 600 GPC system, chloroform was used as the mobile phase and the flow rate was 1 m.
L / min. The column temperature was measured at 40 ° C. The number average molecular weight was calculated using polystyrene as a standard sample. (2) Glass transition temperature Differential scanning calorimeter (DSC, Shimadzu Corporation DSC-
50 type) under a nitrogen atmosphere at a heating rate of 5 ° C./mi.
n and determined. Characteristic value and performance of coating film (1) Appearance Appearance and smoothness were visually evaluated. ：: extremely good, ：: good, Δ: gloss, ×: poor (2) Weather resistance The appearance of the coating film after 2,000 hours of irradiation with a sunshine weather meter was visually evaluated. ◎: extremely good, ○: slightly glossy, Δ: glossy,
×: cracking and peeling (3) Acid resistance The coating film appearance after immersing the coating film in a 5% aqueous sulfuric acid solution at room temperature for 24 hours was visually evaluated. ◎: extremely good, ○: slightly glossy, Δ: glossy,
×: cracking, peeling (4) Curability 1 g of the baked composition was wrapped in a 200-mesh stainless steel wire gauze, immersed in acetone for 24 hours, and the weight change of the composition was examined. 1
00%. ◎: 90% or more, ：: 90 to 80%, Δ: 80 to 70
%, ×: 70% or less (5) Adhesion The adhesion was evaluated by a grid tape method according to JIS K5400. ◎: No missing portion, ○: Within 5% of missing portion, Δ: 5% of missing portion
１５15%, ×: 15% or more of defective part (6) Impact resistance Using a DuPont type impact resistance tester according to JIS K5400 (shot type: radius 6.35 ± 0.03 mm, weight:
500 g), and the impact resistance was examined. (7) Storage stability For powder coatings stored at 40 ° C. for one month, the change in gel fraction before and after storage was examined as a measure of the progress of gelation. ◎: no change, ：: change in gel fraction within 5%, Δ: 5%
Gel fraction change of １５15%, ×: Gel fraction change of 15% or more Resin Production Examples 1 to 3 50 parts of toluene was placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel. After charging and raising the temperature to 110 ° C. while introducing nitrogen gas, the copolymer components shown in Table 1 were dropped at a constant rate over 5 hours by a dropping funnel.
After the addition of the mixture was completed, a mixture of 0.5 part of 2,2′-azobisisobutyronitrile and 10 parts of toluene was added dropwise at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was further heated at 110 ° C. for 1 hour and then cooled. By distilling off the solvent from the resin solution under reduced pressure,
Solid-state resins (α-1) to (α-3) were obtained.

[0048]

[Table 1] (In the table, TESMA is 3-methacryloxypropyltriethoxysilane, MMA is methyl methacrylate,
BA indicates butyl acrylate, GMA indicates glycidyl methacrylate, HEMA indicates 2-hydroxyethyl methacrylate, ST indicates styrene, and AIBN indicates 2,2′-azobisisobutyronitrile. Resin Production Example 4 100 parts of ER-6680 (manufactured by Nippon Ester Co., Ltd .; hydroxyl value 36 mg KOH / g), which is commercially available as a hydroxyl-terminated polyester resin for powder coatings, and 200 parts of toluene are charged into a reaction vessel, and placed under a nitrogen stream. 100 ° C with stirring
And dissolved. A mixture of 8 parts of 3-isocyanatopropyltriethoxysilane and 50 parts of toluene is mixed with 3 parts.
The mixture was added dropwise over 0 minutes, and then stirring was continued for 3 hours. After confirming the completion of the reaction by IR and cooling to room temperature, toluene was distilled off under reduced pressure to obtain a polyester resin having a terminal alkoxysilyl group and a hydroxyl group (resin (α-4)). The resin (α-4) had a number average molecular weight of 3,300 and a glass transition temperature of 58 ° C. Resin Production Example 5 100 parts of ER-6680 (manufactured by Nippon Ester Co., Ltd .; hydroxyl value: 36 mg KOH / g) and 200 parts of toluene, which are commercially available as hydroxyl-terminated polyester resins for powder coatings, are charged into a reaction vessel, and placed under a nitrogen stream. 100 ° C with stirring
And dissolved. A mixture of 16 parts of 3-isocyanatopropyltriethoxysilane and 50 parts of toluene was added dropwise over 30 minutes, and thereafter, stirring was continued for 3 hours. IR
By confirming the completion of the reaction, after cooling to room temperature,
The toluene was distilled off under reduced pressure to obtain a polyester resin having an alkoxysilyl group at both terminals (resin (α-5)). The resin (α-5) had a number average molecular weight of 3,600 and a glass transition temperature of 55 ° C. Comparative Resin Production Examples 1 and 2 By using the copolymer components shown in Table 1 in the same manner as in Resin Production Examples 1 to 3, solid resins (β-1) and (β-2) were obtained. Examples 1 to 5 Using resins (α-1) to (α-5), according to the composition shown in Table 2, all components were mixed with a drive render (Henschel mixer, trade name, manufactured by Mitsui Chemicals, Inc.). After being uniformly mixed for 100 minutes, the mixture is extruded and kneaded under a temperature condition of 100 to 110 ° C. (BUSS Co-Kneader PCS manufactured by BUSS).
-30), and then finely pulverized using a jet pulverizer (trade name: Single Track Jet Mill STJ200 manufactured by Seishin Enterprise Co., Ltd.) to obtain a powder coating (γ) having an average particle size of 30 μm. -1) to (γ-5). The obtained powder coating material was coated on a 0.8 mm-thick zinc phosphate treated steel sheet so as to have a thickness of 50 to 60 μm by an electrostatic coating machine (manufactured by Nippon Wagner Spray Tech Co., Ltd., trade name: Airmatic Spray Co., Ltd.). It was applied using a gun PEM-C1) and baked at 180 ° C. for 20 minutes to form a coating film. Table 2 shows the results of evaluating the performance of the obtained coating film.

[0049]

[Table 2] (In the table, ER-6680 is a hydroxyl-terminated polyester resin manufactured by Nippon Ester Co., Ltd. (hydroxyl value 36 mgKOH / g)
ER-8107 is a carboxyl group-terminated polyester resin manufactured by Nippon Ester Co., Ltd. (acid value: 33 mgKOH / g)
MBTO is monobutyltin oxide, B1530
Is a block isocyanate VESTAGON B 1530 manufactured by Daicel Huls Co., Ltd .; TiO ₂ is a titanium oxide CR-90 manufactured by Ishihara Sangyo Co., Ltd .;
Indicates a leveling agent manufactured by BASF. Comparative Examples 1 to 5 According to Table 3, the powder coatings (γ-6) to (γ-10) were produced by the same method as in the production examples. Further, coating was performed in the same manner as in the Production Example, and the results of evaluating the performance of the obtained coating film are shown in Table 3.

[0050]

[Table 3] (In the table, ER-6680 is a hydroxyl-terminated polyester resin manufactured by Nippon Ester Co., Ltd. (hydroxyl value 36 mgKOH / g)
MBTO is monobutyltin oxide, B1530
Indicates a blocked isocyanate VESTAGONB 1530 manufactured by Daicel Huls Co., Ltd., TiO ₂ indicates titanium oxide CR-90 manufactured by Ishihara Sangyo Co., Ltd., and Acronal 4F indicates a leveling agent manufactured by BASF. )

[0051]

According to the present invention, excellent weather resistance, acid resistance,
It is possible to provide a powder coating having a new cross-linking form, which has appearance, adhesion, and impact resistance, clears environmental problems, and can be manufactured at low cost.

Continued on the front page F-term (reference) 4J038 CA021 CA022 CA131 CA132 CC021 CC022 CC081 CC082 CC091 CC092 CC101 CC102 CD021 CD022 CD081 CD082 CE051 CE052 CG021 CG022 CG031 CG032 CG121 CG122 CH1 CH2 CH1 CH2 CH1 CH1 CH2 CH3 CL011 CL012 DB211 DB212 DB221 DB222 DD001 DD002 DG301 DG302 GA03 GA06 GA07 GA15 JA20 JC13 JC38 JC39 KA03 KA04 MA13 MA14 NA03 NA04 NA11 NA12 NA27 PA02

Claims (20)

[Claims] An essential component is a silyl group-containing vinyl copolymer (A) represented by the following general formula (1) and a polyester resin (B), and the component (A) is represented by the following general formula (1) ) Is a main crosslinkable group, has a glass transition temperature of 40 to 100 ° C, and a number average molecular weight of 20.
00 to 20000, wherein the component (B) has a crosslinkable functional group, and has a glass transition temperature of 40 to 100 ° C;
A resin composition for powder coatings having a number average molecular weight of 2,000 to 20,000. Embedded image (Wherein R ¹ is an alkyl group having 1 to 10 carbon atoms, 6 carbon atoms)
And at least one group selected from the group consisting of an aryl group having 10 to 10 and an aralkyl group having 7 to 10 carbon atoms, and when there are a plurality of groups, they may be the same or different. X is at least one member selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, a phenoxy group, a thioalkoxy group, an acyloxy group, an aminoxy group, a ketoximate group, an amino group, an amide group, and an alkenyloxy group. Group, and when there are a plurality of groups, they may be the same or different. a is an integer of 0 to 2. ) 2. A polymer other than the component (A) that can be crosslinked and cured, and the component (A) accounts for 20% by weight or more and less than 100% by weight of the total of the component (A) and the polymer. The resin composition for a powder coating according to claim 1, wherein: 3. The resin composition for a powder coating according to claim 1, wherein X in the general formula (1) is an alkoxy group. 4. A method according to claim 1, wherein said component (A) is a copolymer of (a) and 1 to 30 parts by weight of a silyl group-containing vinyl monomer (a) represented by the general formula (1). The resin for powder coating according to any one of claims 1 to 3, which is a vinyl copolymer obtained by copolymerizing 99 to 70 parts by weight of a vinyl monomer (b). Composition. 5. The vinyl monomer having a silyl group of the component (a) is 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) 5) at least one selected from the group consisting of acryloxypropylmethyldimethoxysilane and 3- (meth) acryloxypropylmethyldiethoxysilane, or a mixture of two or more thereof. The resin composition for powder coating according to any one of the above. 6. A glycidyl group-containing vinyl monomer containing 5 to 50 parts by weight of 99 to 70 parts by weight of the other copolymerizable vinyl monomer of the component (b). The resin composition for powder coatings according to any one of claims 1 to 5, wherein 7. The glycidyl group-containing vinyl monomer of component (b) is glycidyl (meth) acrylate,
At least one selected from the group consisting of methyl glycidyl (meth) acrylate and allyl glycidyl ether;
The resin composition for powder coating according to any one of claims 1 to 6, wherein the resin composition is a seed or a mixture of two or more thereof. 8. The method of claim 1, wherein the other copolymerizable vinyl monomer of component (b) comprises 1 to 20 parts by weight of a hydroxyl group-containing vinyl monomer out of 99 to 70 parts by weight. The resin composition for a powder coating according to any one of claims 1 to 7. 9. The hydroxyl group-containing vinyl monomer of the component (b) may be 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
-Hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 2. One selected from the group consisting of N-methylol (meth) acrylamide, hydroxystyrene, 2-hydroxy-3-phenoxypropyl acrylate, or a mixture of two or more thereof. 3.
The resin composition for a powder coating material according to any one of claims 1 to 8. 10. The polyester resin as the component (B),
It contains one or two groups selected from the group consisting of a carboxyl group, a hydroxyl group, and a silyl group represented by the general formula (1), and is contained in an amount of 10 to 300 based on 100 parts by weight of the component (A).
The resin composition for powder coating according to any one of claims 1 to 9, wherein the resin composition is used in parts by weight. 11. The powder coating composition according to claim 1, wherein said component (A) contains a glycidyl group, and said component (B) contains a carboxyl group. Resin composition. 12. A resin composition for a powder coating, comprising 1 to 20 parts by weight of an aliphatic dibasic acid (C) based on 100 parts by weight of the composition according to claim 11. 13. The aliphatic dibasic acid of the component (C) is selected from the group consisting of compounds represented by the general formula (2):
The resin composition for powder coating according to any one of claims 1 to 12, wherein the resin composition is a seed or a mixture of two or more thereof. Embedded image (In the formula, R ² is a linear or branched alkylene group having 1 to 20 carbon atoms.) 14. The composition according to claim 1, wherein said component (A) and said component (B) contain a hydroxyl group and contain a compound (D) having a blocked isocyanate and / or a uretdione structure as a curing agent. The resin composition for powder coating according to any one of the above. 15. The component (A) and the component (B) 100
The resin composition for a powder coating material according to any one of claims 1 to 10, further comprising 1 to 30 parts by weight of the component (D) based on part by weight. (16) The component (D) is obtained by converting isophorone diisocyanate and / or hexyl diisocyanate to ε.
-Caprolactam, methyl ethyl ketone oxime, 1,
From blocked isocyanates obtained by reacting with 2-pyrazole, 1,2,4-triazole, diisopropylamine, 3,5-dimethylpyrazole, diethyl malonate, and compounds having a uretdione structure represented by the following general formula (3) 2. The composition according to claim 1, wherein the composition is at least one kind selected from the group consisting of two or more kinds.
The resin composition for a powder coating according to any one of claims 10 to 14, 14, and 15. Embedded image (Wherein, R ³ is an alkylene group having 4 to 12 carbon atoms, an isophorone group, R ⁴ is an alkylene group having 2 to 18 carbon atoms, and n is 1
Is an integer of up to 30 ) 17. The powder according to claim 1, wherein 0.001 to 10 parts by weight of the curing catalyst (E) is added to 100 parts by weight of the component (A). Resin composition for body paint. 18. The component (D) is at least one selected from the group consisting of an organic acidic compound, a mixture or a reaction product of the organic acidic compound and a nitrogen-containing compound, and a mixture of two or more organic metal compounds. The resin composition for a powder coating according to any one of claims 1 to 17, wherein 19. The curing agent as the component (D) is at least one selected from the group consisting of organic sulfonic acids and a mixture of an organic sulfonic acid and a nitrogen-containing compound, or a mixture of two or more types. The resin composition for powder coatings according to any one of claims 1 to 18, wherein 20. The method according to claim 20, wherein the curing agent of the component (D) is at least one selected from the group consisting of an organic tin compound, an organic titanium compound, an organic aluminum compound, and an organic zirconium compound, or a mixture of two or more thereof. The resin composition for a powder coating according to any one of claims 1 to 19, wherein