JPS59133271A - Production of electrodeposition paint - Google Patents

Abstract

PURPOSE:To obtain an electrodeposition paint which gives a mica-electrodeposited insulating layer having a good film strength and has improved heat resistance, by dispersing mica powder in an aq. dispersion of a reaction product between an imide epoxy resin, a glycol and a dicarboxylic acid anhydride. CONSTITUTION:In the production of an electrodeposition paint by using water as a dispersion medium and mica powder and a water-dispersible varnish resin as dispersion phase, there is used, as the water-dispersible varnish, a dispersion obtd. by dispersing in water a reaction product having an acid value of pref. 30-70 obtd. by reacting 100pts.wt. imide epoxy resin (A) obtd. from the reaction of an imide compd. of formula I (wherein R1 is a tetravalent org. group) with an epoxy group, with 2-10pts.wt. glycol (B) of the formula HO-R2-OH (wherein R2 is a bivalent org. group) and 15-40pts.wt. dicarboxylic acid anhydride (C) of formula II (wherein R3 is a bivalent org. group).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an electrodeposition paint using a novel water-dispersed face, and more specifically, a method for producing an electrodeposition paint using a novel water-dispersed face. This invention relates to a method for producing electrodeposition paint using a water-dispersed face.

When mica powder is used alone to electrodeposit on a conductor, the strength of the formed electrodeposited layer is not sufficient, so when the object to be coated is taken out of the electrodeposition tank, the mica powder will fall off, resulting in virtually no damage to the conductor. Electrodeposition is not possible.

A method to improve this point is to add water-dispersed Fes as an organic insulator to mica powder, form a composite insulating layer by co-electrodeposition, and increase the strength of the film (JP-A-51-89178, JP-A-51-114602). Publication No. 56-9212
No. 98) is shown.

In the composite insulating layer, the water-dispersed varnish acts as a binder for the mica powder and provides sufficient film strength. Furthermore, the binder is not used to completely fill the gaps between the amounts of mica powder, but the gaps are generally left and impregnated with a different type of resin depending on the purpose of use to form an insulating coating.

Epoxy resins, acrylic resins, polyester resins, etc. are known as water-dispersed resins used as binders, and mica composite insulating layers obtained by co-electrodeposition usually contain 5 to 60% % (weight%, same below)
Contains.

With the trend toward heat-resistant insulation, heat resistance is also required for mica electrodeposited insulation layers. In order to increase the heat resistance of the layer, it is possible to reduce the ratio of water-dispersed face resin and increase the mica content, but increasing the mica content too much is undesirable because the film strength will decrease, and from that point of view, the heat resistance The development of a water-dispersed festival has been desired.

As a result of intensive research in view of the above-mentioned problems, the present inventors have found that, in a method for manufacturing an electrodeposition paint using water as a dispersion medium and mica powder and a water-dispersed face resin as the dispersed phase, a general formula for a water-dispersed face resin has been developed. (I): 100 parts (parts by weight, the same applies hereinafter) of an imide epoxy resin (A) obtained by reacting an imide compound represented by 0 0 (in the formula, R is a tetravalent organic group) with an epoxy resin. ), 2 to 10 parts of glycol (B) represented by the general formula (■): HO-R2-OH (II) (in the formula, R2 is a divalent organic group), and further ): (wherein R3 is a divalent organic group) A dispersion liquid in which a reaction product (D) obtained by reacting 15 to 40 parts of dicarboxylic acid anhydride (a) is dispersed in water. We have found that the above problem can be solved by using the following.

That is, in the present invention, by using a water-dispersed face with good heat resistance as a pz filter water-dispersed face for electrodeposition coating, it is possible to improve the coating strength and heat resistance of the mica deposition edge layer. I/A effective power (obtained).

The imide compound represented by the general formula CI) used in the present invention can be easily separated by reaction between an organic tetracarboxylic anhydride and ammonia. As the organic tetracarboxylic acid anhydride that can be used here, (is o 0
0 0 111 is given.

Epoxy resins used in the present invention include diglycidyl ether type Epcoat 828 (manufactured by Shell Chemical Company), Coro 32 (manufactured by Dow Chemical Company), and novolac type DEN 438 (manufactured by Dow Chemical Company).
, alicyclic type ay-179 (manufactured by Ciba Geigy), and the like.

The imide compound and the epoxy resin usually have a molecular weight of 80 to 2
Imide epoxy resin (A) is obtained by reacting at 00°C without or in the presence of a catalyst.

Examples of the glycol represented by the general formula (■) used in the present invention include ethylene glycol, propylene glycol, and butanediol.

The acid anhydride represented by general 2〇[l) may be any cyclic acid anhydride, such as phthalic anhydride,
Examples include tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and the like.

In the present invention, when obtaining the reaction product (D), a solventless reaction is also possible, but it is preferable to use a solvent such as xylene or toluene. Non-catalytic reactions are also possible, but Lewis acid catalysts such as tertiary amines, quaternary ammonium salts, BF3 salts, zinc octylate, tin octylate,
Metal salts such as cobalt acetylacetonate can also be used.

The reaction product (D) used in the present invention is 2 to 10 parts of glycol (B) per 100 parts of imide epoxy resin (A),
It is obtained by reacting 15 to 40 parts of dicarboxylic acid anhydride (0) at 80 to 200°C in the presence of the above-mentioned solvent or in the absence of a solvent, in the presence of the above-mentioned catalyst or in the absence of a catalyst.

The water-dispersed face used in the present invention is a reaction product (D) 10
0 parts to 6 to 30 parts of volatile base and 0.1 parts of surfactant
50 to 2500 parts of an aqueous solution containing 5 parts of
It can be obtained by dispersing at 90°C and further distilling off volatile substances from the aqueous solution. The reaction product (D) used here is obtained by the above reaction and preferably has an acid value of 30 to 70. If the acid value is higher than 70, the difference in mobility between the water-dispersed face resin particles and the mica powder during electrodeposition is too large, making it impossible to form a uniform composite insulating layer. On the other hand, if the acid value is lower than 60, it may become difficult to disperse in a dispersion medium, the particle size in the dispersed state may become too large, and the moisture content of the composite insulating layer formed may become too high to be of practical use. do.

Suitable volatile bases used when dispersing the reaction product (D) in water include aqueous ammonia, trimethylamine, triethylamine, and the like. Although there are no particular restrictions on the surfactant, anionic, nonionic, or a mixture thereof are advantageous from the standpoint of stability of the water-dispersed face, such as sodium laurylbenzenesulfonate, sodium laurylbenzenesulfonate, Examples include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dodecyl sulfate, and polyethylene glycol laurate monoester.

The production of an electrodeposition coating using the obtained water-dispersed face is carried out using 100 to 65 mica powder per 10 parts of solid content of the water-dispersed face of the imide epoxy resin, which is the reaction product (D).
This is carried out by adding 0 parts of the solids and diluting with water so that the total solids concentration is 10 to 20%.

According to the method of the present invention, when an electrodeposition paint is produced using the imide epoxy resin with high heat resistance as a component of a water-dispersed face, the electrodeposition paint that provides a composite insulating layer with high heat resistance can be easily washed away. can.

Next, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Example 1 Imide compound represented by formula (I-1): 43.2. (0.2 mol) and IER3321369 (0.4 mol), imide epoxy resin 1709, ethylene glyfur 12g, tetrahydrophthalic anhydride 609, xylene 409, zinc octylate 0.24. , and reacted at 150°C for 1.5 hours to obtain a reaction product with an acid value of 50. 60° of acetone was added to the obtained reaction product to reduce its viscosity, and it was mixed with 2,000° of an aqueous solution containing 50° of a 28% ammonia aqueous solution and 29° of a lauryl sulfate ester sorter. and stirred at 70°C for about 60 minutes to disperse. Thereafter, air was blown into the dispersion to volatilize ammonia, and the pH was adjusted to 5% Cgi.

The dissolved water-dispersed face and mica powder were mixed at a solid content weight ratio of i5:85, and adjusted by dispersion and piping to produce an electrodeposition paint.

A copper rectangular wire was electrodeposited using the electrodeposition paint at an applied voltage of 80 V to form a composite insulating layer.The resulting insulating layer was good.

828,190 parts of copper rectangular wire G phosphoric acid anhydride-curing epoxy-impregnated resin (Kobiko) having a composite insulating layer,
Impregnation treatment with an impregnating resin consisting of 150% methyltetrahydrophthalic anhydride and 1 part benzyldimethylamine),
The baking process was performed to form an insulating film with a thickness of 100 μm.

Thereafter, the mica content 1 in the insulating coating, the initial dielectric breakdown voltage, and the dielectric breakdown voltage after deterioration for 20 days at 260° C. were measured.

The results are shown in Table 1.

Example 2 Imide compound represented by formula (I-2) <S3.2. (0.2 mol)
and Epicote 828 152. (0.4 mol) of imide epoxy resin 200. , propylene glycol 89.7, 50 g of talic anhydride, and 40 g of xylene were mixed and reacted at 145°C for 2 hours until the acid value was 5.
A reaction product of 5 was obtained. 50 g of A7T was added to the obtained reaction product to reduce the viscosity, and it was poured into 200 Op of an aqueous solution containing 30 g of a 28% ammonia aqueous solution and 1.5 g of polyethylene glycol oleate monoester. Dispersion was achieved by stirring at 75°C for approximately 60 minutes.

Thereafter, air was blown into the dispersion to volatilize ammonia, and the pH was adjusted to 13.

The obtained water-dispersed face and mica powder were dispersed and adjusted to have a solid content weight ratio of 15:85 to produce an electrodeposition paint.

A rectangular copper wire having a good composite insulating layer was prepared in the same manner as in Example 1 using the electrodeposition paint, and impregnated with the epoxy impregnated resin.

The same measurements as in Example 1 were performed on the obtained sample.

The results are shown in Table 1.

Example 3 A composite insulating layer was formed in the same manner as in Example 1, except that the weight ratio of solid content between the water-dispersed face and mica powder in Example 1 was changed to 60:70, and impregnated with epoxy impregnated resin. , a sample was prepared.

The same measurements as in Example 1 were performed on the obtained sample.

The results are shown in Table 1.

Comparative Examples 1 to 2 Instead of the water dispersion type festival used in Example 1, epoxy festival (Ebico) 1001, which has been conventionally used, was used.
A sample was prepared in the same manner as in Example 1 using a water-dispersed varnish consisting of tetrahydrophthalic anhydride and ethylene glycol) or an acrylic varnish (a water-dispersed varnish consisting of acrylonitrile, styrene, ethyl acrylate, and glycidyl methacrylate). and investigated its characteristics.

The results are shown in Table 1.

From Table 1, it can be seen that the dielectric breakdown voltage after deterioration of the sample using the water-dispersed varnish used in the method of the present invention is better than that of the conventional case, and the heat resistance is good.

Agent: Shin Kuzuno (1 other person) =557-

Claims (4)

[Claims] (1) In a method for producing an electrodeposition coating using water as a dispersion medium and mica powder and water-dispersed face resin as the dispersed phase, the general formula % formula % (in the formula, R is 4 General formula (■): HO-R2-OH' (I[) (In the formula, R2 is a divalent organic group) 2 to 10 parts by weight of glycol (B), and further general formula (■): 1 (In the formula, R3 is a divalent organic group) A method for producing an electrodeposition coating material, which comprises using a dispersion in which a reaction product (D) obtained by reacting 15 to 40 parts by weight of the dicarboxylic acid anhydride (c) shown above is dispersed in water. (2) Claim (1) characterized in that the reaction product (D) is one having an acid value of 60 to 70.
A method for manufacturing the electrodeposition paint described in Section 1. (3) The dispersion contains 6 to 30 parts by weight of a volatile base and 0.1 to 5 parts by weight of a surfactant based on 100 parts by weight of the reaction product (D).
The method for producing an electrodeposition paint according to claim 1, wherein the dispersion is prepared by dispersing 500 to 2,500 parts by weight of an aqueous solution containing parts by weight. (4) A method for producing an electrodeposition paint according to claim (1), characterized in that a solvent is used in the reaction of the imide epoxy resin (A), the glycol (B), and the dicarboxylic acid anhydride (0). .