JPS61188449A - Dipping material for capacitor - Google Patents

Abstract

PURPOSE:To obtain a dipping material which can be cured in a short time without causing sagging and can impart improved moisture resistance, by blending an unsaturated polyester resin, a vinyl monomer, a photopolymerization initiator and a heat polymn. initiator. CONSTITUTION:A dipping material is obtd. by blending an unsaturated polyester resin, a vinyl monomer, a photopolymerization initiator and a heat polymn. initiator and kneading the mixture. Preferred examples of the unsaturated polyesters are isophthalate and terephthalate polyesters. Preferred examples of the vinyl monomers are alpha,beta-unsaturated vinyl monomers. An example of the photopolymerization initiator is benzoin ethyl ether. Pref. 20-80pts.wt. unsaturated polyester resin, 80-20pts.wt. unsaturated vinyl monomer, 0.2-5pts. wt. (per 100pts.wt. resin) photopolymerization initiator and 0.1-5pts.wt. (per 100pts.wt. resin) heat polymn. initiator are blended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a dipping material for capacitors, which improves moisture resistance by dipping sealing capacitors, particularly film capacitors.

[Background Art] Conventionally, film capacitors have been encapsulated with resin by dipping, but the conventional dipping material used was a heat-curable two-component epoxy resin. However, this product takes 2 to 24 hours to harden.
In the past, there was a disadvantage that the curing time was long, and therefore, the resin dripped before curing, resulting in so-called bulges, which had to be removed later.

In addition, to improve these shortcomings, there is a method in which the dipping material is made of an acrylate-based ultraviolet curing resin and cured instantly upon irradiation with ultraviolet rays. It has the drawbacks of being easily damaged and having poor moisture resistance.

[Object of the Invention] The present invention has been made in view of the above points, and provides a dipping material that can be cured in a short time, does not cause the dipping material to drip, and does not impair the dielectric properties of the capacitor. The purpose of the present invention is to provide a dipping material for capacitors that can further improve moisture resistance.

[Disclosure of the Invention J] That is, the dipping material for capacitors of the present invention is made by blending an unsaturated polyester resin, a vinyl resin, a photopolymerization initiator, and a thermal polymerization initiator, and is cured by ultraviolet rays. This makes it possible to eliminate sagging of the material, and by using an unsaturated polyester resin as the resin, the dielectric properties and moisture resistance are improved, thereby achieving the above objectives.

The present invention will be explained in detail below. The dipping material according to the present invention is prepared by mixing and kneading an unsaturated polyester resin, a vinyl monomer, a photopolymerization initiator, and a thermal polymerization initiator. As the unsaturated polyester resin, it is preferable to use iso or tele, and as the vinyl monomer, it is preferable to use a-, β-unsaturated vinyl monomers, such as evastyrene, methylstyrene, vinyltoluene, etc. One to three types can be used. Moreover, benzoin ethyl ether or the like can be used as a photopolymerization initiator.

As a thermal polymerization initiator, t-butyl peroxybenzoate or the like can be used. The amount of each of these ingredients is unsaturated polyester! , 20 to 80 parts by weight of resin (hereinafter simply referred to as parts), 80 to 20 parts of unsaturated vinyl monomer, and 100 parts of these resins, and 0.2 parts of photopolymerization initiator.
It is preferable to use 5 parts of the thermal polymerization initiator and 0.1 to 5 parts of the thermal polymerization initiator, and a polymerization inhibitor may be added if necessary. In this way, each component is mixed to obtain a dipping material for a capacitor.

After impregnating a film capacitor into the capacitor dipping material prepared as described above and coating the film capacitor with the dipping material,
The dipping material is removed from the dipping material and irradiated with ultraviolet rays to harden the surface of the dipping material.Then, the film capacitor coated with the dipping material is placed in a heating furnace and heated to harden. By blending the unsaturated polyester resin and the unsaturated vinyl monomer ultraviolet curable resin in this way, the surface can be instantly cured by ultraviolet irradiation and the curing time can be shortened. For example, the handling possible (usable) time can be set to 5 to 20 seconds. In other words, it is possible to take 5 to 10 seconds to impregnate the undercoat and 5 to 10 seconds to apply the topcoat. Moreover,
Unlike conventional capacitors, resin does not drip from the capacitor, and so-called navels do not occur.

In addition, by changing the resin used from the conventional 7 acrylate ultraviolet curable resin to polyester resin,
The dielectric properties and moisture resistance can be improved, and in particular, the original dielectric properties of a film capacitor can be exhibited.

The present invention will be specifically described below based on examples.

A dipping material for a capacitor was obtained by mixing 30 parts of methyl styrene, 3 parts of pencil dimethyl ketal 411S, and 3 parts of t-butyl peroxybenzony with 100 parts of in-7-talic acid polyester resin (35% styrene, viscosity 3000 cps). Ta.

! Solid isophthalic acid polyester resin (softening point 86℃)
A dipping material for a capacitor was obtained by mixing 100 parts of styrene monomer, 4 parts of pencil dimethyl ketal, and 3 parts of t-1 tylpa-1oxybenzoate.

Huangfujiu and Suphenol A type epoxy acrylate (viscosity 20,000c)
A dipping material for a capacitor was obtained by mixing 250 parts of phenyldiethylene glycol methacrylate (AMP6PG, manufactured by Shin Nakamura Chemical) and 7.5 parts of pencil dimethyl ketal zoate per 100 parts of ps/50°C.

Regarding the above capacitor depping materials, the capacity is 1n.
F, a 100 nF polypropylene film capacitor and a 100 nF polyester film capacitor were impregnated and cured to obtain a resin-sealed film capacitor. The impregnation and curing conditions are as follows.

Impregnation conditions: Immersed in a vacuum of 20 mmHg (torr) for 1 minute.

Curing conditions: Using an 80 W/am high pressure mercury lamp, irradiate with ultraviolet rays for 10 seconds at a distance of 20 cm from the lamp, then
It was heated in a 0°C curing oven for 2 hours.

Thereafter, the initial capacitance Co and the capacitance C after the moisture resistance test of the resin-sealed film capacitor were measured. The humidity resistance condition was that it was left in an atmosphere of 40° C. and 95% RH for 1000 hours. Note that the measurement was performed using a YHP LCR meter at IKHz. The results are shown in Table 1.

From the results in Table 1, the initial value of capacitor capacitance and the V capacitance change rate ΔC/Co (%) of Examples 1 and 2 are significantly smaller than those of Comparative Examples, and the dielectric properties of Examples 1 and 2 are significantly smaller than those of Comparative Examples. It was confirmed that the moisture resistance and moisture resistance were improved. Table 1 [Effects of the Invention] As described above, the present invention is based on the combination of an unsaturated polyester resin, an unsaturated vinyl monomer, a photopolymerization initiator, and a thermal polymerization initiator. Therefore, the surface can be cured in a short time by irradiation with ultraviolet rays, preventing the resin from dripping, and eliminating the traditional hassle of removing the belly button. By using resin as the main component, it is possible to improve the dielectric properties and moisture resistance of the capacitor.

Agent Patent Attorney Ishi 1) Chief 7th Procedural Amendment (spontaneous) April 8, 1985, □51-1, Indication of the case 1985 Patent Application No. 27134 2, Name of the invention Dipping material for capacitors 3, Relationship with the case of the person making the amendment Patent applicant address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative Sadao Fujii 4 Agent postal code 530 Address 1-12-17 Umeda, Kita-ku, Osaka 58 Date of amendment order 6 Number of inventions increased by amendment None 7 , Subject of amendment 1) "Vinyltoluene" on page 3, line 14 to line 15 of the specification will be corrected to "novinylbenzene."

2) rAMP6PG on page 6, lines 8 and 9 of the same page.”
Correct it to rAMP60GJ.

3) "Dipping material" in line 13 of the same page is corrected to "dipping material."

4) Correct "to ultraviolet rays" in the fourth line of No. 9\L of the above to "of ultraviolet rays."

Claims (1)

[Claims] (1) A dipping material for capacitors characterized by being formed by blending an unsaturated polyester resin, a vinyl monomer, a photopolymerization initiator, and a thermal polymerization initiator.