JPS60206874A - Paint resin composition - Google Patents

Abstract

PURPOSE:To provide a paint resin compsn. which gives a coating film having excellent durability and is suitable for use as automotive solid color, by blending a specified compd. which can lower surface tension and absorb an ultraviolet light, an alkyd resin and an amino-formaldehyde resin. CONSTITUTION:A compd. which can lower surface tension and absorb an ultraviolet light, obtd. by reacting a perfluoroalkyltrimethylammonium with 2-hydroxy-4-methoxybenzophenone in a hydrophilic solvent, is used. 0.01-3pts.wt. said compd. (A), 64.99-77pts.wt. hydroxyl group-contg. alkyd resin (B) and 20- 35pts.wt. amino-formaldehyde resin (C) (pref. melamine resin) etherified with a 1-4C monohydric alcohol are blended together (the sum of components A, B and C being 100pts.wt.).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved resin composition for coatings, and more particularly, the present invention relates to an improved resin composition for coatings, and more particularly, the present invention relates to an improved resin composition for coatings, and more particularly, the present invention relates to an improved resin composition for coatings, which has particularly high durability, and is made by incorporating a specific compound that has both surface tension lowering ability and ultraviolet absorption ability. The present invention relates to a resin composition for paint that provides an excellent coating film.

In recent years, from the perspective of saving resources, there has been a strong desire for paints with excellent weather resistance, and this demand is even stronger in the automobile industry, where paints that can maintain their luster even after being exposed outdoors for up to three years have been strongly desired. Therefore, in terms of accelerated weather resistance, it is desired that the gloss does not deteriorate over a long period of time.

By the way, as resins for top coats for automobiles, acrylic resins have been used in combination with melamine-formaldehyde resins mainly for metallics, and for solid colors, Short oil alkyd resin modified with coconut oil or synthetic fatty acids,
It has also been used in combination with melamine-formaldehyde resins.

However, none of the salvaged resins has a high degree of weather resistance.

However, in view of these circumstances, the present inventors have conducted extensive research in order to obtain a coating composition that has a high degree of weather resistance. The present invention has now been completed by discovering a useful resin composition for coatings containing specific compounds as described below.

That is, the present invention uses Tsuku-fluoroalkyltrimethylammonium and 2-hydroxy-4 as essential components.
- 0.01 to 3 parts by weight of the compound obtained by reacting with methoxybenzophenone-5-sulfonic acid, 64.99 to 77 parts by weight of the hydroxyl group-containing alkyd resin (B), and C1 Amino-formaldehyde resin etherified with m alcohols of ~C4 (0
in a range of 20 to 35 parts by weight, and these (6), (
The object of the present invention is to provide a coating resin which provides a coating film with excellent weather resistance, which is particularly useful as a solid color for automobiles, and which contains components B) and (Q) in a total amount of 100 parts by weight.

In general, for metallic finishes, the durability is significantly improved by incorporating a UV absorber into the clear topcoat, whereas for solid color coatings that contain a large amount of pigment, Since the clear layer on the surface of the film is itself thin, the effect of such an ultraviolet absorber cannot be expected.

The main reason for this is that the ultraviolet absorber, which is present in a dispersed form throughout the solid color coating, has a great effect.
After all, it is simply impossible.6For that reason, at present,
Progress is being made in the direction of improving the UV resistance of the resin itself, and even though d-alkyd resins are being considered to have ultra-short oil or oil-free (alkyd) resins, if such methods are used, the appearance of the paint film will be Pigment dispersibility and texture of the coating surface, which affect the quality of paint, tend to be inferior.

On the other hand, when using the composition of the present invention, the ultraviolet absorber is concentrated in the clear layer on the surface of the coating film.
There is no need to select a special resin system, and weather resistance can be dramatically improved using conventional resin systems.

The compound (6), which is a particularly important constituent factor among the essential components constituting the composition of the present invention, is a combination of fluoroalkyltrimethylammonium and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. This reaction proceeds easily in a hydrophilic solvent such as isopropropanol.

Here, as the above-mentioned 4-fluoroalkyltrimethylammonium, for example, "Megafu'7tsukuF-
150" (cationic fluorine thread surfactant manufactured by Dainippon Ink & Chemicals Co., Ltd.) can be used. The compound (4) has surface tension lowering ability and ultraviolet ray resistance. The composition of the present invention obtained by incorporating the compound has the same improvement in weather resistance as when a well-known and commonly used ultraviolet absorber is applied as an intermediate layer of the top coat. It was confirmed that this expression occurs.

Furthermore, by incorporating an antioxidant into the composition of the present invention, the effect of improving weather resistance becomes even more remarkable.

On the other hand, the above-mentioned alkyd resin (B) is not particularly limited except that it contains a hydroxyl group, and as long as it is conventionally used as a solid color resin for automobiles, animal or vegetable oils or vegetable oils may be used. Alkyd resins modified with their constituent fatty acids and oil-free alkyd resins may be used, and one or more of these two types of resins may be selected as appropriate.

Next, the above-mentioned amino-formaldehyde resin (Q is etherified with m alcohols of C1 to C4,
For example, melamine resins, guanamine resins, acetoguanamine resins, and urea resins are commonly used, and melamine resins are most preferred as solid color resins.

And essential ingredients (4) and (B) as listed above.
And (the blending ratio of Q is (A): (B)
: (Q=0.01~3:64.99~77:20~
A suitable ratio is 35 (parts by weight).

Here, if the amount of component (A) used is less than 0.01 part by weight, the effect of improving weather resistance cannot be expected; on the other hand, if it exceeds 3 parts by weight, warpage and decoloring of the coating film may occur. Either case is undesirable because the gloss, sharpness, acid resistance, moisture resistance, etc. of the film will be significantly inferior.

Furthermore, if the amount of the component (0) used is less than 20 parts by weight, a coating film with sufficient hardness will not be obtained;
If it exceeds 35 parts by weight, the weather resistance will deteriorate and the physical properties of the coating will become extremely brittle depending on the baking temperature.
Either case is not preferable.

The thus obtained resin composition for coatings of the present invention is particularly excellent in various types of durability such as weather resistance, so it can be used in inorganic materials such as slate and roof tiles in a form in which pigments are blended for purposes such as weather resistance. It is applied to a wide range of applications, including building materials and paints for various building materials such as galvanized iron.
Suitable as an automotive solid color paint.

Next, the present invention will be specifically explained with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and parts are based on weight unless otherwise specified.

Reference Example 1 [Example of Preparation of Compound (6)] Into 11 four-piece flasks equipped with a stirrer, a thermometer, and a dropping funnel, 500 parts of isopronol and 56 parts of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid were added. 111 parts of perfluoroalkyltrimethylammonium were added thereto and stirred at a temperature of 50° C. for 1 hour to complete the reaction. The target compound obtained here was a light brown transparent liquid.

Reference Example 2 [Preparation example of hydroxyl group-containing oil-modified alkyd resin (B)] 380 parts of coconut oil, 0.15 parts of lithium hydroxide, and 152 parts of trimethylolpropane were charged.
After carrying out an alcohol exchange reaction at 0°C for 1 hour, 376 parts of phthalic anhydride and 9 parts of pentaerythritol were added to this.
4 parts of trimethylolethane and 40 parts of xylene were added, maintained at a temperature range of 160-180°C for 3 hours, and then gradually raised from 180°C to 220°C over 2 hours, Further, a dehydration reaction was carried out at 220°C for 3 hours.

After that, the non-volatile content was diluted with xylene to 60 cm, and the Gardner viscosity at 25°C was
A solution of a target resin having an acid value of 6.0 and a hydroxyl value of 77 was obtained.

Reference example 3 [Hydroxy group-containing oil-free alkyd resin (B)
Example of Preparation] 180 parts of isophthalic acid, 180 parts of adipic acid, 120 parts of trimethylol glomerone and 180 parts of neopentyl glycol were heated at 180°C for 2 hours with stirring in an inert gas stream, and then heated to 220 parts of C. for about 7 hours to obtain a polyester resin with an acid value of 8.

Next, this resin was mixed with xylene/butyl cellosolve = 9/
It was diluted with a mixed solvent of 1.1 (weight ratio) so that the non-volatile content was 60. The Gardner viscosity was UV and the acid value was 4.
5 and a hydroxyl value of 70 was obtained.

Examples 1 to 6 Resin compositions of the present invention were prepared using the formulations shown in Table 1 and according to the procedure described below.

That is, 87 parts of the hydroxyl group-containing alkyd resin of Reference Example 2 or 3;
Tsurupetz 100j [mixture of aromatic hydrocarbons manufactured by Esso Petrochemical Co., Ltd.] was blended in a proportion of 25 parts and kneaded in a sand mill for 2 hours to prepare a red paste, and each of the reference examples listed in Table 1 was prepared. A specified amount of compound (6) obtained in step 1 and [Super Beckamine G-821-60J (Dainippon Ink & Chemicals Co., Ltd.)]
A paint was prepared by blending a specified amount of 1io-butyl etherified melamine resin manufactured by Co., Ltd.; non-volatile content = 60%] and its additives.

Next, each paint was applied to a zinc phosphate steel plate treated with Ndellite≠144 using an air spray paint machine (4 atmospheres) so that the film thickness was 35 to 40 μm.
After setting for 10 minutes, set at 140℃ for 30 minutes.
A cured coating was obtained by baking in a hot air dryer for a minute.

Thereafter, the performance of each coating film was evaluated. The results are summarized in Table 2, and the methods and evaluation criteria for each performance test are as follows.

However, Examples 1 to 5 are examples in which the alkyd resin of Reference Example 2 and Example 6 of Reference Example 3 were used.

Gloss: Measurement of 60 degree reflectance (chi) Sharpness: Visually determined Hardness: Displayed as the hardness of the pencil before it is dammed using "Uni" manufactured by Mitsubishi Pencil Co., Ltd. did.

Weather resistance due to outdoor exposure...In Pakkok City, Thailand,
The gloss retention rate (CH) after exposure for 1 year and 2 years, respectively, at a south facing angle of 5 degrees is expressed.

Accelerated weather resistance... Sunshine Uniday Meter (
The gloss retention rate (%) after exposure for 1,000 hours and 2,000 hours is shown.

Wax discoloration test: A flannel cloth was dipped in Wilunten All J (silicone wax manufactured by Wilson Co., Ltd.) and rubbed against a glass plate under a 500g load 30 times. El was measured using a color difference meter manufactured by Nippon Denshoku Co., Ltd., and exposed under the specified conditions at the location and time shown in the table, and the exposed coating was rubbed 30 times in the same manner. The case where the object was measured was set as E2, and El-El was calculated as ΔE.

Humidity resistance: Changes in the coating film were visually judged after being left in a high temperature and humid atmosphere at 50° C. and RH of 98 degrees or more for 72 hours.

Acid resistance: 0.5 ml of a 5-thiosulfuric acid aqueous solution was dropped onto the coating film and left to stand for 24 hours, after which changes in the coating film were visually determined.

Comparative Examples 1 to 6 Comparative compositions were prepared in the same manner as Examples 1 to 5, except that the composition was changed to the one shown in Table 1, and the compositions were made into paints, and then painted and cured. A membrane was obtained. Thereafter, the performance of each coating film was evaluated and is summarized in Table 2.

However, Comparative Examples 1 to 5 are based on Reference Example 2, and Comparative Example 6 is based on Reference Example 3.
This is an example using an alkyd resin.

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Claims (1)

[Claims] (A) Perfluoroalkyltrimethylammonium and 2-hydroxy-4-methoxybenzophenone-5-
The compound obtained by reacting with sulfonic acid is 0.01~
3 parts by weight, (B) 64.99 to 77 parts by weight of a hydroxyl group-containing alkyd resin, and (C) a ratio of 35 parts by weight to amino-formalde etherified with a -hydric alcohol of Os to C. and further comprising the above-mentioned essential components (B) and (Q) in a total amount of 100 parts by weight,
A resin composition for paints that provides a particularly durable coating film.