JPH0150247B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a polyester resin (A) containing paratertiary butylbenzoic acid (hereinafter abbreviated as PTBBA) in an amount of 25 to 60 mol% based on the total acid component of the polyester resin, an amino resin and/or or polyisocyanate prepolymer (B), with weather resistance, gloss,
The present invention relates to a resin composition for paint that provides a coating film with excellent processability. When synthesizing polyester resins and alkyd resins, PTBBA is added to the total acid content of polyester resins.
It has been proposed, for example, in JP-A-52-27498 and JP-A-52-74695 to coexist 10 to 20 mol % of these compounds and use them as a molecular weight regulator, ie, a chain stopper. However, the polyester resins described in these patent publications have a small amount of PTBBA, and the molecular weight of the resulting resin is also small, making it impossible to obtain a coating composition that provides a coating film with sufficient weather resistance. In addition, many conventional polyester resins contain a large amount of aromatic rings formed by aromatic polycarboxylic acids in the main chain, and although the resin as a whole is hard and has good weather resistance, the processability of the coating film, that is, the painted iron plate, is poor. However, a polyester resin that satisfies both weather resistance and processability has not yet been found. However, as a result of intensive research, the present inventors found that a large amount of
Using PTBBA as polyester resin raw material,
It was discovered that increasing the molecular weight of the resulting resin has a surprising effect on improving weather resistance, gloss, and physical properties, leading to the completion of the present invention. That is, the coating resin composition of the present invention contains (1) 40 to 75 mol% of aliphatic, aromatic, or alicyclic, polyhydric carboxylic acid or its derivative (2) paratertiary acid as the total acid component of the polyester resin. Butyl benzoic acid
25-60 mol% (3) Other polycondensable carboxylic acids
0 to 35 mol% as a total alcohol component (4) Trihydric or higher polyhydric alcohol 65 to 100 mol% (5) Glycol 0 to 35 mol% Polyester resin (A) with a number average molecular weight of 500 to 5000 obtained by reacting ) and an amino resin and/or polyisocyanate prepolymer (B). Aliphatic, aromatic, alicyclic, or polycarboxylic acids or their derivatives used as the polyester resin acid component of the present invention (However, the aliphatic polycarboxylic acids referred to here refer to unsaturated bonds that have radical polymerizability. Examples include orthophthalic acid, its anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid,
Sebacic acid, dodecanedicarboxylic acid, tetrahydrorthophthalic acid, its anhydride, hexahydrorthophthalic acid, its anhydride, hexahydroisophthalic acid, hexahydroterephthalic acid, alkyl orthophthalic acid, its anhydride, alkyl isophthalic acid, alkyl Terephthalic acid, naphthalene dicarboxylic acid, halogenated orthophthalic acid, its anhydride,
Halogenated isophthalic acid, halogenated terephthalic acid, endomethylenetetrahydrophthalic acid, its anhydride, alkylated endomethylenetetrahydrophthalic acid, its anhydride, endomethylene hexahydrophthalic acid, its anhydride, hexachloroendomethylenetetrahydrophthalic acid, Examples thereof include trimellitic acid and its anhydride, trimellitic acid and its anhydride, monoesters and diesters of lower alcohols thereof, and pyromellitic acid and its anhydride. These acid components may be used alone or in combination of two or more, and the total amount of acid components in the polyester resin is
Use 40-75 mol%. In this case, if the amount is less than 40 mol%, it will be difficult to form a resin, and the resulting resin will have a small molecular weight, resulting in poor weather resistance and processability. Also, PTBBA can be used if it exceeds 75 mol%.
The amount of this decreases, resulting in insufficient weather resistance. Furthermore, in detail, in order to obtain a coating resin composition with good weather resistance and processability, which is the object of the present invention,
As the (1) polycarboxylic acid in the polyester resin (A), use a mixture of aliphatic polycarboxylic acid/(aromatic + alicyclic polycarboxylic acid) in a molar ratio of 100/0 to 20/80. is preferred. In this case, if the ratio of aliphatic polyhydric carboxylic acid is less than 20/80, the processability of the resulting coating film will be reduced. Furthermore, to improve the weather resistance and processability of the coating film, the ratio of PTBBA/aromatic and/or alicyclic polycarboxylic acid should be adjusted to 90/10 to 20/80.
(molar ratio). In addition, (2) in the total acid component of polyester resin
The amount of PTBBA is 25-60 mol%, preferably 30-50
It is mole%. In this case, if it is less than 25 mol%,
The weather resistance, which is the objective of the present invention, is poor, and if it exceeds 60 mol%, processability and weather resistance are poor. Other polycondensable carboxylic acids (3) can be used in an amount of 0 to 35 mol %, if necessary. In particular, α,β-unsaturated dicarboxylic acids such as maleic acid or its anhydride, fumaric acid, itaconic acid, citraconic acid, etc. may be used, the amount being 10
It is preferably less than 10% by mole, and if it exceeds 10% by mole, the water resistance and processability of the coating film will deteriorate. In addition, monocarboxylic acids such as relatively weather-resistant fatty acids such as coconut oil, cottonseed oil, rice bran, tall oil, soybean oil, and safflower oil, versatic acid (manufactured by Ciel Chemical Co., Ltd.), etc. may be used; In this case, the amount used is preferably 10 mol% or less. If it exceeds 10 mol%, weather resistance will deteriorate. Other monocarboxylic acids such as benzoic acid, acetic acid, propionic acid, naphthenic acid, stearic acid,
Oleic acid, abietic acid, rosin, and polyhydric carboxylic acid partial esters having one or more carboxyl groups can also be suitably used. Trivalent or higher polyhydric alcohol used as alcohol component of polyester resin in the present invention
Examples of (4) include trimethylolethane, trimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, 1,2,6-
One or more of hexanetriol, pentaerythritol, diglycerin, dipentaerythritol, and sorbitol can be used. The polyhydric alcohol (4) is used in an amount of 65 to 100 mol%, preferably 75 to 100 mol%, based on the total alcohol component. In this case, if it is less than 65 mol%, weather resistance is poor. Glycol (5) can be used in the polyhydric alcohol (4) in an amount of 0 to 35 mol % based on the total alcohol component, if necessary. Examples of such glycols (5) include ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol,
trimethylene glycol, 1,4-butanediol, pentamethylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol,
2,2,4-trimethyl-1,3-pentanediol, cyclohexanediol, dimethylolcyclohexane, hydrogenated bisphenols, alkylene oxide adducts of hydrogenated bisphenols, alkylene oxide adducts of bisphenols, halogenated Glycols such as alkylene oxide adducts of bisphenols are used. In addition, if necessary, fatty acid glycidyl esters, such as Cardiela E (manufactured by Ciel Chemical Co., Ltd.)
α-olefin oxide e.g. AOEX-24,
AOEX-68 (manufactured by Daicel) etc. can also be used together. Furthermore, the amino resin (B) in the present invention is a resin obtained by adding formaldehyde to urea, melamine, benzoguanamine, acetoguanamine, etc., and etherifying the resulting methylol group with an alcohol having 1 to 8 carbon atoms. Use alone or in combination of two or more. A part of this amino resin (B) may be reacted with the polyester resin (B) at 50 to 150°C in advance to co-condense it. In addition, the amino resin (B) is blocked with para-toluenesulfonic acid, phosphoric acid esters, partial esters of dicarboxylic acids such as phthalic acid and maleic acid, acid curing catalysts such as dinonylnaphthalene disulfonic acid, and amines. It is also possible to use the above-mentioned acid curing catalysts in combination. The polyisocyanate prepolymer (B) used in the present invention includes trimethylene diisocyanate,
Tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, 1,4
- Aliphatic or cycloaliphatic diisocyanates such as dicyclohexene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 3-methyldiphenylmethane diisocyanate, chlorophenylene diisocyanate , obtained by reacting an excessive amount of polyisocyanate such as aromatic diisocyanate such as naphthalene diisocyanate and diphenyl ether diisocyanate with polyhydric alcohol such as ethylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, hexanetriol, and trimethylolpropane. A polyisocyanate prepolymer with isocyanate end groups. Blocked polyisocyanate prepolymers obtained by blocking these polyisocyanate prepolymers with phenol, lactam, active methylene, alcohol, mercaptan, acid amide, imine, amine, imidazole, urea, oxime or sulfite can also be used. A block dissociation catalyst such as dibutyltin dilaurylate or dibutyltin diacetate can also be used in this prepolymer (B). The method for producing the polyester resin (A) of the present invention includes (1) aliphatic, aromatic or alicyclic polycarboxylic acid, (2) paratertiary butylbenzoic acid, (4) trivalent or higher polyvalent carboxylic acid, A method in which alcohol and optionally (3) polycondensable carboxylic acid and (5) glycol are simultaneously charged and reacted. After melting alcohol and other liquid raw materials in (4) and (5), solid raw material (1) is prepared. , (2), (3), etc. are charged and reacted, (4) trihydric or higher polyhydric alcohol is reacted with (2) paratertiary butylbenzoic acid, and then the remaining acid and alcohol raw materials are reacted. Methods for preparing and reacting, as well as (1), (2), (3),
There is a method in which one or more of each of the raw materials (4) and (5) is divided into two or more portions and sequentially charged into a reaction vessel and reacted. These esterification or transesterification reactions are accomplished by heating the starting materials to 160-260°C in an inert gas stream. In this way, a polyester resin (A) having a molecular weight of 500 to 5,000 is obtained. The acid value of the polyester resin (A) is in the range of 0.1 to 40, preferably 0.1 to 20. The polyester resin (A) thus obtained was mixed with toluene, xylene, "Solbetsuso-100" (product of Exxon, USA), "Solbetsuso-150" (product of Exxon, Inc.), "Swazol-1000" (product of Maruzen Oil Co., Ltd.), "Swazol-1500" (product of the company)
Aromatic hydrocarbons such as butanol, butyl cellosolve, alcohols such as 3-methyl-3-methoxybutanol (Kuraray Yuka Co., Ltd. product); esters such as ethyl acetate, butyl acetate, cellosolve acetate; or methyl ethyl ketone, Ketones such as methyl isobutyl ketone, cyclohexanone, isophorone, etc. with non-volatile content of 20-80%, especially 40-60%
It is desirable to dilute it to %. In addition to the above polyester resin (A), pigments such as inorganic pigments, organic pigments, and metal powders, surface conditioning agents such as pigment dispersants, anti-sagging agents, anti-wrinkle agents, and smoothing agents, other polyester resins, alkyd resins, and acrylics. Resin, epoxy resin, cellulose acetate butyrate, nitrified cotton, VAGH (manufactured by Union Carbide),
It is also possible to contain synthetic resins such as petroleum resins. By blending an amino resin and/or a polyisocyanate prepolymer (B) with this, the resin composition for paint of the present invention having excellent weather resistance, hardness, and processability can be obtained. Its uses are similar to general saturated polyester resin paints, such as pre-coated metal, pre-coated aluminum, automobile top coats, automobile undercoats, road sign reflectors, steel furniture, can manufacturing, and other general baking paints. I can do things. Next, the present invention will be specifically explained with reference to Examples. Example 1 30 parts by weight of phthalic anhydride (the following parts indicate parts by weight), 17 parts of adipic acid, 20 parts of paratertiary butylbenzoic acid (hereinafter abbreviated as PTBBA), trimethylolpropane (hereinafter abbreviated as TMP) 33
10 parts of neopentyl glycol were placed in a four-neck flask equipped with a thermometer and an air condenser, heated at 180°C for 2 hours in an inert gas stream, and then heated at 220°C for 2 hours.
The mixture was heated at ℃ for 8 hours to obtain a polyester resin having a molecular weight of 2500 and an acid value of 10.1. This was diluted with a mixed solvent of xylene/butyl cellosolve = 9/1 to a non-volatile content of 60%, and added to 70 parts of a polyester resin and added with "Super Betsukamine L-117-60" (butylated melamine manufactured by Dainippon Ink & Chemicals Co., Ltd.). 30 parts of resin] were blended. The obtained clear paint was applied to a steel plate treated with zinc phosphate (Bonderite #144 treatment manufactured by Nippon Test Panel Co., Ltd.)
Painted so that the dry coating film was 30μm, and heated at 150℃
The paint film was created by baking in 20 minutes. Example 2 35 parts of phthalic anhydride, 35 parts of PTBBA, 38 parts of TMP,
A polyester resin having a molecular weight of 1600 and an acid value of 9.5 was obtained in the same manner as in Example 1. Thereafter, the same operations as in Example 1 were performed. Example 3 15 parts of phthalic anhydride, 22 parts of adipic acid,
Molecular weight 1850, acid value from 35 parts PTBBA and 39 parts TMP
Everything was carried out in the same manner as in Example 1, except that a polyester resin of No. 6.8 was obtained. Example 4 40 parts of phthalic anhydride, 10 parts of coconut oil fatty acid,
The procedure was exactly the same as in Example 1 except that a polyester resin having a molecular weight of 2,600 and an acid value of 10.3 was obtained from 20 parts of PTBBA and 39 parts of TMP. Example 5 5 parts of phthalic anhydride, 40 parts of adipic acid,
The same procedure as in Example 1 was carried out except that a polyester resin having a molecular weight of 5,000 and an acid value of 10 was obtained from 32 parts of PTBBA and 37 parts of trimethylolethane. Example 6 15 parts of isophthalic acid, 5 parts of hexahydrophthalic anhydride, 19 parts of adipic acid, 35 parts of PTBBA,
The same procedure as in Example 1 was carried out except that a polyester resin having a molecular weight of 2200 and an acid value of 9.5 was obtained from 36 parts of TMP and 3 parts of pentaerythritol. Example 7 To 100 parts of the polyester resin obtained in Example 3, 60 parts of "Burnock DN-950" [isocyanate prepolymer manufactured by Dainippon Ink and Chemicals Co., Ltd.] was added to prepare a composition of the present invention. Clear paint was obtained. A dry coating film is formed on the zinc phosphate treated steel sheet described above.
It was applied to a thickness of 30 μm and dried at 80° C. for 20 minutes. Comparative Example 1 Molecular weight from 50 parts of phthalic anhydride, 10 parts of adipic acid, 31 parts of neopentyl glycol and 17 parts of TMP
Example 1 was carried out in exactly the same manner as in Example 1, except that a polyester resin having an acid value of 2400 and an acid value of 9.9 was obtained. Comparative Example 2 Molecular weight determined from 41 parts of phthalic anhydride, 25 parts of benzoic acid, 39 parts of TMP, and 3 parts of neopentyl glycol
Example 1 was carried out in exactly the same manner as in Example 1, except that a polyester resin having an acid value of 1600 and an acid value of 8.9 was obtained. Comparative Example 3 23 parts of phthalic anhydride, 20 parts of adipic acid, benzoic acid
The procedure was exactly the same as in Example 1 except that a polyester resin having a molecular weight of 2100 and an acid value of 9.2 was obtained from 25 parts of TMP and 43 parts of TMP. Comparative Example 4 40 parts of phthalic anhydride, 13 parts of adipic acid,
The procedure was exactly the same as in Example 1, except that a polyester resin having a molecular weight of 2,400 and an acid value of 10 was obtained from 10 parts of PTBBA, 25 parts of TMP, and 21 parts of neopentyl glycol. The results of a coating film performance test performed on the painted test pieces obtained in each of the above Examples and Comparative Examples are shown below. 【table】

Claims (1)

[Scope of Claims] 1. Total acid components of the polyester resin: (1) 40 to 75 mol% of aliphatic, aromatic, or alicyclic polycarboxylic acids or derivatives thereof (2) paratertiary butylbenzoic acid
25-60 mol% (3) Other polycondensable carboxylic acids
0 to 35 mol% as a total alcohol component (4) Trihydric or higher polyhydric alcohol 65 to 100 mol% (5) Glycol 0 to 35 mol% Polyester resin (A) with a number average molecular weight of 500 to 5000 obtained by reacting ) and an amino resin and/or a polyisocyanate prepolymer (B).