JPH0258532A - Modified polyester resin composition and coating using same - Google Patents

Abstract

PURPOSE:To provide the title composition capable of giving coatings of excellent resistance to scratch, contamination and chemicals, containing a modified polyester resin prepared by reaction of a polyester resin with a specific reactive silicone oil. CONSTITUTION:The objective composition containing a modified polyester resin >=5,000 in number-average molecular weight, which can be prepared by reaction of (A) a polyester resin formed by reaction between (i) an acid component comprising 100-40mol.% of aromatic dicarboxylic acid and 0-60mol.% of aliphatic carboxylic acid and (ii) an alcohol component consisting mainly of diol with (B) 0.1-5wt.% of a reactive silicone oil of formula I [m and n are each integer >=1; X1, X2 and X3 are each CH3, -OR<1>, -R<2>OH, -R<2>COOH, -R<2>NH2 or of formula II (R<1> is alkyl; R<2> is alkylene)].

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a modified polyester resin composition containing the same that is effective as a coating material with excellent scratch resistance, stain resistance, and chemical resistance. Regarding the paint.

[Conventional technology]

Traditionally, painting of home appliances, etc. was done after processing and forming steel plates.
Previously done in a box-shaped form, in order to solve various problems such as streamlining the painting line, improving productivity, preventing pollution, and improving the work environment, a pre-coat painting method was developed in which flat steel plates are processed and formed after being painted. is moving to. The pre-to-1-m board used in this method is processed into a complicated shape after painting, so high workability is required. On the other hand, among home appliances, refrigerators, washing machines, etc. are required to have high performance in coating film hardness, lη staining resistance, and chemical resistance.

Conventionally, thermosetting acrylic resins have been mainly used for coating these home appliances. This is because acrylic resin paints have excellent coating hardness and stain resistance.

However, acrylic resin paints do not have enough workability to be used for pre-coating, and in order to satisfy the processability, it is necessary to soften the composition of the acrylic resin, and it is necessary to soften the composition of the acrylic resin to create a coating film that can withstand practical use. Hardness and stain resistance are difficult to demonstrate.

In addition, thermosetting polyester resins have been used for coil coatings such as colored galvanized iron, but they still have the drawback of not being able to balance processability, coating film hardness, and stain resistance. However, high molecular weight polyester resin obtained by polycondensing polyester resin under reduced pressure has superior processability compared to ordinary polyester resin, and has been put to practical use in coating home appliances such as refrigerators and washing machines. .

[Problem to be solved by the invention]

However, even these high molecular weight polyester resins do not have sufficient hardness, stain resistance, and chemical resistance compared to conventionally used acrylic resins.

The present invention provides a modified polyester resin composition and a coating material that have excellent processability, scratch resistance, stain resistance, and chemical resistance.

[Means to solve the problem]

The present invention provides a modified polyester resin composition with good scratch resistance, stain resistance, and chemical resistance by introducing a reactive silicone oil into a polyester resin with good processability.

That is, the present invention provides a polyester resin obtained by reacting an acid component containing aromatic dicarboxylic acid ≠ 100 to 40 mol % and aliphatic dicarboxylic acid 0 to 60 mol % with an alcohol component containing diol as the main component. General formula (1): [wherein m and n are integers of 1 or more, X3, X2 and X are methyl groups, -OR'-R20H1R''C
00H1-R”NH, or may be different (except when Xl, X2 and X3 are all methyl groups), R' is an alkyl group, and R2 is an alkylene group] The present invention relates to a modified polyester resin composition containing a modified polyester resin having a number average molecular weight of 5,000 or more obtained by reacting reactive silicone oil with 1 to 5% by weight of O, and a coating material containing the same.

Examples of the aromatic dicarboxylic acid used in the polyester resin of the present invention include terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, and their lower alkyl esters and acid anhydrides. can be used. Examples of aliphatic dicarboxylic acids include adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, hymic acid, cyclohexane dicarboxylic acid, and lower alkyl esters and acid anhydrides of these acids may also be used. , one or more of these can be used. Aromatic dicarboxylic acid and aliphatic dicarboxylic acid each account for 100 to 40 mol% of the total acid component.
, used in a range of 0 to 60 mol%. When the aliphatic dicarboxylic acid content exceeds 60 mol %, hardness and stain resistance, particularly stain resistance, decrease.

The diol of the polyester resin used in the present invention includes ethylene glycol, 2-propanediol,
1.3-propanediol, I3-butanediol, 1
, 4-butanediol, neopentyl glycol, 1,
5-pentanediol, 16-hexanediol, 3-
Methylbentanediol, diethylene glycol, 1.
Examples include 4-cyclohexane dimetatool, 1,4-dicyclohexane dimetatool, xylylene glycol, or aromatic bisphenol A adducts with ethylene oxide and propylene oxide, and one or more of these can be used. .

The polyester resin used in the present invention may further include a trivalent or higher polyhydric alcohol and/or a polybasic acid. When these are contained, solvent resistance and gloss are further improved. Of course, these also include those containing both a hydroxyl group and a carboxyl group. Examples include glycerin, trimethylolethane, trimethylolethane, pentaerythritol, dimethylolpropionic acid,
Examples include trimellitic acid, pyromellitic acid, trimesic acid, and the like. It is preferable to use one or more of these in an amount of 5% by weight or less based on the total raw materials of the polyester resin. If it exceeds 5% by weight, processability tends to decrease.

The reactive silicone oil used in the present invention is represented by the general formula (1) and has one or more of an alkoxy group, a hydroxyl group, a carboxy group, an amino group, or an epoxy group. These can be used alone or in combination of two or more. These are 0.1% in modified polyester resin.
It is used in a range of 5% by weight. If it is less than 0.1% by weight, there is no effect on scratch resistance, stain resistance and chemical resistance, and 5
If it exceeds % by weight, the resin obtained tends to become cloudy and the gloss of the coating film decreases.

The modified polyester resin of the present invention can be produced by a conventional method. For example, first, the above acid component and alcohol component are used in a ratio such that the carboxyl group of the acid component and the hydroxyl group of the alcohol component are approximately equivalent to an excess of hydroxyl groups, and if necessary, in the presence of a catalyst, the ratio of 150 to 300'
Esterification or transesterification is carried out at C, followed by adding silicone oil and removing excess alcohol components by transesterification at 200 to 300''C under reduced pressure, preferably below lmmHg. A modified polyester resin having a high molecular weight can be obtained.The polyhydric alcohol having a valence of 3 or more and/or the polybasic acid may be added at normal pressure under an inert gas atmosphere before or after the pressure reduction.

The modified polyester resin thus obtained needs to have a number average molecular weight of 5,000 or more, preferably 30,000 or less. If the number average molecular weight is less than 5,000, processability will decrease. Furthermore, if the number average molecular weight is too large, the gloss tends to decrease.

In the present invention, the "number average molecular weight" is measured using gel permeation chromatography using a standard polystyrene calibration curve.

In addition to the above-mentioned modified polyester resin, the modified polyester resin composition of the present invention may be used in combination with other polyester resins to the extent that the properties thereof are not affected. aromatic hydrocarbons,
It is diluted with solvents such as aliphatic hydrocarbons, esters, and ketones and used as paints, adhesives, etc.

To obtain the paint of the present invention, an amino resin obtained by reacting the modified polyester resin composition with formaldehyde and an amino compound such as melamine, urea, benzoguanamine, etc. It is used in combination with amino resins such as etherified amine resins obtained by etherification with lower alcohols such as, etc., to form thermosetting paints. In this case, the solid content ratio (weight ratio) of the modified polyester resin and the amino resin is 90/10 to 60/40, preferably 85
It is suitable that the ratio is from /15 to 70/30.

Furthermore, the modified polyester resin of the present invention can be used as a coating material by using polyisocyanate as a curing agent.

Examples of the polyisocyanate include isophorone diisocyanate, diphenylmethane diisocyanate, m-xylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, dodecane dicarbonyl diisocyanate, and the like. It will be done. In addition, these can be used as blocking agents, alcohols such as methanol, ethanol, 2-butoxycetanol,
Examples include blocked isocyanates masked with phenols such as phenol and cresol, lactams such as caprolactam and butyrolactam, and oximes such as cyclohexane oxime and methyl ethyl ketone oxime.

The blending amount is such that the isocyanate value and the hydroxyl value of the modified polyester resin composition are approximately 1:1.

Furthermore, pigments, plasticizers, colorants, and/or acid catalysts such as p-1-luenesulfonic acid may be added as appropriate.

The paint thus obtained can be applied to the surface of iron, non-ferrous metals, etc. by a known method such as spray coating or roll coating.

〔Example〕

Next, the present invention will be explained with reference to Examples, but the present invention is not limited thereto.

Example 1 (A) 166 parts by weight (1.0 mol) of terephthalic acid, 207.5 parts by weight (1.25 mol) of isophthalic acid, 141 parts by weight (0.75 mol) of azelaic acid, 124 parts by weight of ethylene glycol ( 2.0 mol), 156 parts by weight (1.5 mol) of neopentyl glycol, and 1 part by weight of dibutyltin dioxide O were subjected to an esterification reaction at 250'C in the presence of an inert gas to produce a polyester with an acid value of 5.0. Resin (A
) was obtained.

(B) 10 parts by weight of silicone oil modified with alcohol at both ends F-99-199 (manufactured by Nippon Unicar Aji, OH equivalent 540) was added to 490 parts by weight of polyester resin (A).
．． A polycondensation reaction was carried out at 8 mmHg and 270'C to obtain a modified polyester resin having a number average molecular weight of 17,000.

Example 2 Modified polyester resin 50 obtained in Example 1 (B)
7.5 g of dimethylolpropionic acid was added to 0 parts by weight at normal pressure at 260°C under an inert gas atmosphere to perform a depolymerization reaction, resulting in a modified polyester resin with an acid value of 5.8 and a number average molecular weight of 10,000. Obtained.

Example 3 In (B) of Example 1, silicone oil Y-1587 (Japanese:
A modified polyester resin having a number average molecular weight of 116,000 was obtained by operating in the same manner as in Example 1, except that 5iOR equivalent (manufactured by L Nika@, 5iOR equivalent: 380) was used.

Comparative Example 1 A polyester resin having a number average molecular weight of 17,000 was obtained in the same manner as in Example 1 except that in (B) of Example 1, both terminal alcohol-modified silicone oil F-99-199 was omitted.

Comparative Example 2 In (B) of Example 1, polyester resin (A)
450 parts by weight and silicone oil F99-199;
The same procedure as in Example 1 was performed except that 50 parts by weight was used to obtain a cloudy modified polyester resin having a number average molecular weight of 17,000.

Comparative Example 3 Silicone oil F- was added to the polyester resin of Comparative Example 1.
2% of 99-199 was added and mixed with stirring.

The molecular weight was determined by connecting Hitachi Model 635 HLC and Gelvac R440, R450, and R400M columns (all manufactured by Hitachi Chemical Co., Ltd.) in series and obtaining a chromatogram using tetrahydrofuran as the eluent. Calculated based on polystyrene.

Making paint The resins obtained in each example and comparative example were heated to a 40% solution using Tsurupetz 150 (Shell Chemical Co., Ltd., trade name)/cyclohexanone/cellosolve acetate = 1/1/1 (weight ratio). It was adjusted.

The above resin liquid was made into a paint using the following formulation.

Resin liquid of Example or Comparative Example 300 parts by weight Melan 5
23 (Methylated melamine, Hitachi Chemical ■Product name) 30 parts by weight Rutile type titanium white 150 parts by weight p-) Luenesulfonic acid 1.5 parts tffi Thinner [Solhenoso 150
/cyclohexanone = 1/1 (weight ratio)] 69 parts by weight The above paint was applied to Bonderai #144 treated steel plate (manufactured by Nippon Test Panel Co., Ltd., thickness 0.5 mm) with an applicator so that the dry film thickness was 20 μm. Coated and baked at 280'C for 80 seconds.

The resulting coating film was tested in the following manner.

Measured at a gloss incident angle of 60° (J I S K 5400
).

Pencil hardness measured using Mitsubishi Uni (JIS K 540
0).

Workability A 70x40mm test piece was cut vertically at 180° from the center.
Folded and pressed.

Evaluation 5: No cracks 3: 1/3 cracks present 1: Fully cracked Stain resistance After 24 hours, the marker ink marks on the test piece were wiped off with a pheasant roll.

evaluation 5...No ink marks.

3... Slight ink marks remain.

1... Ink marks clearly remain.

The surface of the coating film was rubbed 10 times with scratch-resistant work gloves, and the degree of scratches was observed.

O: No abnormality ×: Many scratches 5% NaOH resistance The degree of gloss and pique after being soaked in a 5% NaOH aqueous solution at 35°C for 24 hours was observed.

O...No abnormality.

×...Glossy pique is observed.

Table 1 [Effects of the Invention] The modified polyester resin composition of the present invention and the coating material containing the same produce coating films with excellent processability, scratch resistance, chemical resistance, and stain resistance.

As is clear from the above results, the paint containing the modified polyester resin composition of the present invention has better scratch resistance and chemical resistance (5% NaO resistance) than that of unmodified Comparative Example 1.
H properties) and stain resistance. Comparative Example 2 is a case in which a large amount of reactive silicone oil is used, but the gloss is reduced. Comparative Example 3 is a case where silicone oil is simply blended, but the gloss is reduced and the chemical resistance and stain resistance are also reduced.

Claims (1)

[Claims] 1. A polyester resin obtained by reacting an acid component containing 100 to 40 mol% of aromatic dicarboxylic acid and 0 to 60 mol% of aliphatic dicarboxylic acid with an alcohol component containing diol as the main component. , General formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, m and n are integers of 1 or more, and X_1, X_2
and X_3 is a methyl group, -OR^1, -R^2OH, -
R^2COOH, -R^2NH_2 or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, which may be the same or different (however, X_1, X_2 and X_3
are all methyl groups), R^1 is an alkyl group, and R^2 is an alkylene group] The number obtained by reacting 0.1 to 5% by weight of a reactive silicone oil represented by A modified polyester resin composition containing a modified polyester resin having an average molecular weight of 5,000 or more. 2. The modified polyester resin composition according to claim 1, which is obtained by using a trihydric or higher polyhydric alcohol and/or a polybasic acid in an amount of 5% by weight or less as the acid component and/or alcohol component. 3. A paint comprising the modified polyester resin composition according to claim 1 or 2.