JPS63207818A - Alkyd resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition, having excellent weather resistance, gloss, compatibility with amino resins, etc., and useful as coatings, etc., by reacting a specific glycidyl ester with a polyhydric alcohol and polybasic acid. CONSTITUTION:The aimed composition, obtained by reacting (A) monoglycidyl ester of p-tert-butylbenzoic acid in an amount of 10-50wt.% based on the total components with (B) a polyhydric alcohol having 2-6 hydroxyl groups in one molecule (e.g. ethylene glycol) and (C) a polybasic acid having 2-4 carboxyl groups in one molecule or ester-forming derivative thereof, (provided that an alicyclic dicarboxylic acid or ester-forming derivative thereof accounts for 30-70mol.% thereof) and containing an alkyd resin having 50-200 hydroxyl value (solid) and 2-20 acid value solid).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an alkyd resin composition suitable for use in paints, which has excellent weather resistance, gloss, and compatibility with amino resins and the like.

(Conventional technology) In recent years, there has been a strong demand for maintenance-free paints with excellent weather resistance from the perspective of resource conservation.In particular, in the automobile industry, paints with weather resistance are superior to conventional coconut oil or synthetic fatty acid-modified alkyd resins as top coats. Oil-free polyester resin paints are attracting attention due to their excellent properties.

However, such paints have drawbacks such as easy repellency, poor gloss and blurring of the paint film, and poor compatibility of alkyd resins with base resins such as amino resins.
It was considered difficult to apply it to top coat paints.

Therefore, we maintain the weather resistance of conventional oil-free polyester resin paints, and prevent the occurrence of repelling, gloss of the paint film, and blurring.
In an attempt to improve the compatibility of alkyd resins with base resins such as amino resins, a large amount of alicyclic polycarboxylic acids are used as the polybasic acid component of oil-free polyester resins, or coconut oil or synthetic fatty acid-modified alkyds are used. It has been proposed to use a combination of alicyclic polycarboxylic acid and aromatic polycarboxylic acid as the polybasic acid component of the resin (Japanese Patent Laid-Open No. 56-20
(See Japanese Patent Application Laid-Open No. 57-36149).

(Problems to be Solved by the Invention) However, even when such an oil-free polyester resin modified with an alicyclic polycarboxylic acid is used, the occurrence of cissing and the compatibility with amino resins are somewhat improved. Synthetic fatty acids using a combination of alicyclic polycarboxylic acids and aromatic polycarboxylic acids, and coconut oil-modified alkyd resins have improved weather resistance to some extent, but the gloss of the paint film is lower than that of conventional synthetic fatty acids. Moreover, it is difficult to say that it overcomes the drawbacks compared to vegetable oil-modified alkyd resins.

Therefore, the object of the present invention is to obtain an alkyd resin which has a high degree of weather resistance and has a gloss comparable to that of conventional alkyd resins.

(Means and effects for solving the problems) The present invention achieves the above object by using a monoepoxidized metal having a specific structure as a component of an alkyd resin.

That is, the present invention uses (A) monoglycidyl ester of p-tart-butylbenzoic acid in an amount of 10 to 50% by weight based on the total components, and (B) has 2 to 6 hydroxyl groups in one molecule. Polyhydric alcohol and (C) polybasic acid having 2 to 4 carboxyl groups in one molecule or its ester-forming derivative (however, 30 to 70 moles of alicyclic dicarboxylic acid or its ester-forming derivative) %), with a hydroxyl value of 50 to 200 (solid) and an acid value of 2 to 20 (solid)
An object of the present invention is to provide an alkyd resin composition containing an alkyd resin.

Since p-tart-butyl benzoic acid monoglycidyl ester, which is the component (A), has a benzene ring in one molecular chain, the refractive index of the resulting alkyd resin increases,
A high-gloss coating is obtained. Furthermore, the presence of the tart-butyl group provides a higher degree of weather resistance than a skeleton consisting only of benzene rings, and also improves compatibility with other resins such as amino resins. A compound that can be expected to have a similar effect is p-tert-butylbenzoic acid, but due to its poor reactivity, unreacted substances tend to remain in the resin, and paints using this resin are difficult to avoid due to repellency during painting. cause the occurrence. Furthermore, in order to obtain a coating film with high gloss,
If the amount of this substance used is increased, it has the disadvantage that physical properties are significantly deteriorated.

The amount of p-tart-butylbenzoic acid monoglycidyl ester is 10 to 5% based on the total amount of raw materials for the alkyd resin.
0% by weight, preferably 20-40% by weight. 1
If it is less than 0% by weight, gloss and compatibility with other resins such as amino resins will be poor, and if it exceeds 50% by weight, physical properties and moisture resistance will be deteriorated.

The polyhydric alcohol that is component (B) includes ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,6-hexanediol, cyclohexane dimetatool, 1,5-bentanediol, 1,2- or 1,3-
Butylene gelicol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, ester diol 204 (Union Carbide Co., Ltd. trade name)
Examples include ε-caprolactone.

In the polybasic acid or its ester-forming derivative component (C), the alicyclic dicarboxylic acid or its ester-forming derivative is used in an amount of 30 to 70 mol%, preferably 40 to 60 mol%; If it is less than 70 mol %, the weather resistance will be poor, and if it exceeds 70 mol %, the gloss of the coating film and the dispersibility for organic pigments will be reduced. As the remaining polybasic acid or its ester-forming derivative, aromatic and aliphatic carboxylic acids or their ester-forming derivatives can be used. This is preferable because it provides a good balance between hardness and high gloss of the coating film. As the alicyclic dicarboxylic acid, 1,1-
Cyclohexane dicarbonic acid, hexahydrophthalic acid,
Examples include 1,3-cyclohexanedicarboxylic acid and methylhexahydrophthalic acid. Examples of other carboxylic acids having 2 to 4 carboxyl groups include phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hemic acid, het acid, and trimellitic acid.

Examples include adipic acid, azelaic acid, and sebacic acid.

Examples of the ester-forming derivatives include acid anhydrides and alkyl esters such as dimethyl ester.

In addition to the above-mentioned components (A), (B) and (C), oils or fatty acids can also be used, and as the oils or fatty acids, animal and vegetable oils such as coconut oil and rice bran oil, or these fatty acids are preferable. , these are used in an amount of not more than 10% by weight, preferably not more than 5% by weight, based on the total components.

The alkyd resin can be synthesized by any known method, and is not particularly limited. For example, all components are mixed in a refluxing solvent such as xylene for 1 hour while blowing nitrogen gas.
After raising the temperature to 80℃ and keeping it at this temperature for about 1 hour, 200℃
This can be carried out by raising the temperature to 240° C. and allowing the reaction to occur at this temperature until the desired physical property values are achieved.

All components have a hydroxyl group/carboxyl group (equivalent ratio) of L1/
It is preferable that the ratio be 1 to L5/1, particularly preferably L25/1 to L35/1. If this equivalent ratio is too small, the hydroxyl value will be too low, and if it is too large, the hydroxyl value will be too large.

Here, the monoglycidyl ester of p-tart-butylbenzoic acid is assumed to have two OH groups, the acid anhydride group is assumed to be two carboxyl groups, and other carboxyl groups such as reactive ester groups are assumed to have two OH groups. A group having a similar function in the condensation reaction as the group is considered a carboxyl group.

The hydroxyl value of the alkyd resin obtained from the above components is 50
-20o (solid), preferably 80-150 (solid); if it is less than 50, the crosslinking density will be low when combined with a curing agent such as an amino resin, and the hardness, moisture resistance, and chemical resistance of the coating film will be poor. Moreover, when it exceeds 200, the number of hydroxyl groups remaining in the coating film increases, and the moisture resistance of the coating film and the adhesion during recoating decrease.

The acid value of the alkyd resin obtained from the above components is 2 to 20.
(solid), preferably 3 to 10 (solid); if it is less than 2, the curability is poor when combined with a curing agent such as an amino resin, and the hardness, physical properties, and moisture resistance of the coating film are poor. Moreover, when it exceeds 20, the stability of the paint and the adhesion when coated once are reduced.

In addition to amino resins, polyisocyanates or blocked polyisocyanates can be used as curing agents in the alkyd resins according to the invention.

The above-mentioned amino resin may be one obtained by addition condensation of a heptamine compound such as melamine, urea, benzoguanamine, etc. and an aldehyde such as formaldehyde, and the addition condensation product may be added to methanol or isobutanol.

There are also those obtained by alkyl etherification with lower alcohols such as n-butanol. It is preferable to mix the amino resin and the alkyd resin in a weight ratio of 40/60 to 10/90. If this ratio becomes too large, the elongation, impact resistance, and acid resistance of the coating film will decrease. If it becomes too small, the gasoline resistance and water resistance of the coating film will tend to decrease.

As the polyisocyanate, a compound having two or more isocyanate groups in one molecule can be used, for example,
Examples include hexamethylene diisocyanate, a trimer thereof, isophorone diisocyanate, a trimer thereof, and polyisocyanates generally used as curing agents for polyurethane paints can be used. Blocked polyisocyanates include those in which the isocyanate groups of the above-mentioned polyisocyanates are blocked with ethyl acetoacetate, E-caprolactam, or the like.

Polyisocyanate or blocked polyisocyanate has an inocyanate group (or blocked isocyanate group) of α8 per equivalent of hydroxyl group of the alkyd resin.
It is preferable that the isocyanate group be blended in an amount of ~L25 equivalents, and particularly preferably in an amount of α8~LO equivalents.If there are too many isocyanate groups, the water resistance of the coating film tends to decrease.

If it is too small, gasoline resistance and water resistance tend to deteriorate.

The alkyd resin in the present invention can be used in combination with other components as necessary, aromatic solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohol solvents such as isobutanol and n-butanol, and ethylene. It is preferably used after being dissolved in an organic solvent such as ethylene glycol alkyl ether such as glycol monomethyl ether or ethylene glycol monobutyl ether.

Furthermore, the alkyd resin according to the present invention can be used as nitrocellulose,
It can also be used as a resin for lacquer-type paints in combination with cellulose derivatives such as cellulose acetate butyrate.

(Example) Next, the present invention will be described in detail based on Examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by weight" unless otherwise specified. Example 1 126 parts of p-tart-butylbenzoic acid monoglycidyl ester and 99 parts of trimethylolpropane were placed in an IQ4 Turow flask equipped with a stirrer, a thermometer, a dehydration trap tube, a cooling tube, and a nitrogen gas introduction tube. Part s, 57.3 parts of 1.6-hexanediol, 42 parts of neopentyl glycol, 150 parts of phthalic anhydride, 150 parts of hexahydrophthalic anhydride
9 parts and 60 parts of xylene were charged, heated to 180°C,
After keeping warm for 2 hours, the temperature is raised to 220°C. Further, the reaction was allowed to proceed until the acid value reached 5.1 at the same temperature, and after cooling, the solid content was reduced to 6 using Kijiroll.
It was adjusted to 0%.

Examples 2 to 3 Synthesis was carried out in the same manner as in Example 1 using the formulations shown in Table 1 below.

Example 4 Into the same apparatus as in Example 1, 180 parts of p-tart-butylbenzoic acid monoglycidyl ester, 89.3 parts of trimethylolpropane, 9 parts of neopentyl glycol 6a, 138 parts of hexahydrophthalic anhydride, and 40 parts of quidylol were charged. , the temperature was raised to 180°C, the reaction mixture was allowed to proceed until the acid value (solid) reached 2aO, and the reaction mixture was cooled and phthalic anhydride 1
Add 4 parts of 4a and 20 parts of pheasant roll, and raise the temperature to 180°C.

After keeping it at the same temperature for 2 hours, the temperature was further raised to 220℃, and the acid value was 3.
．． The reaction proceeds until the temperature reaches 3 (solid), and the temperature is lowered to 180°C. ε
- 87 parts of caprolactone was charged, kept at the same temperature for 1 hour, cooled, and adjusted to a solid content of 60% with pheasant roll.

Comparative Examples 1 to 3 Synthesis was carried out in the same manner as in Example 1 using the formulations shown in Table 1.

Paints were prepared as follows using the alkyd resins obtained in Examples 1 to 4 and Comparative Examples 1 to 3 above.

(A) Resins of Examples 1 to 4 and Comparative Examples 1 to 3 (solid content 60
%) Tyebake CR-90 (rutile type titanium white manufactured by Ishihara Sangyo Co., Ltd.) Dispersed using three rolls of Dispavik 160 (manufactured by Bic Chemi Co., Ltd.) until the particle size became 3 μm or less.

(B) Resin of coating Examples 1 to 4 and Comparative Examples 1 to 3 obtained in (A) (solid content 60%) Melan 284A (Hitachi Chemical ■trade name, butylated melamine resin) BYK (BIK Chemi Co., Ltd. ml) ) The above paint with thinner (Tsurupets 150/Tsurupets -
100/butyl acetate/butyl cellosolve=40/30/
Ford Cup #4.20 seconds (20/10, weight ratio)
20°C).

Apply the above viscosity-adjusted paint to 35 to 40μ (
A test plate was prepared by spray painting it so that it would dry (dry) and baking it at 140°C for 30 minutes.

The results of the coating film performance test are shown in Table 2.

(Margin below) (Note) l) Sharpness: The glossiness of the coating film was visually evaluated using the following criteria.

O: Very good 0: Good O: Very good Δ: Bad Hardness when no scratches occur 4) Accelerated weather resistance: JIS with Sunshine Weather-Ometer manufactured by Suga Test Instruments
A test was conducted under the conditions of DO205, and the gloss retention rate was found to be low.

5) Erichsen: Measured with an Erichsen testing machine manufactured by Eriksen Co., Ltd. 6) Humidity resistance: 50 ± 1°C, relative humidity 98% with a humidity testing machine manufactured by Suga Test Instruments
Test under the above conditions 7) Acid resistance: 5% sulfuric acid was dropped onto a 1 m2 coating film, wiped off after 24 hours under conditions of 23±1° C. and 65±5% relative humidity, and evaluated according to the following criteria.

0: Very good 0: Good ■ = Slightly matte Δ: Shine ×: Blistering and dissolution 8) Gasoline resistance: Soaked in Nippon Oil's silver gasoline for 4 hours, and evaluated the degree of coloring and softening according to the following standards It was evaluated by

O: Very good 0: Good 0: Very good Δ: Bad Produces a membrane.

11-, Agent: Patent Attorney Kunihiko Wakabayashi, - （）゛

Claims (1)

[Claims] 1. (A) monoglycidyl ester of p-tert-butylbenzoic acid is used in an amount of 10 to 50% by weight based on the total components; (B) 2 to 6 hydroxyl groups in one molecule; and (C) a polybasic acid having 2 to 4 carboxyl groups in one molecule or its ester-forming derivative (however, among these, the alicyclic dicarboxylic acid or its ester-forming derivative has 30 to 70 mol%) with a hydroxyl value of 50 to 200 (solid) and an acid value of 2 to 20 (solid)
An alkyd resin composition comprising an alkyd resin.