JPS617513A - Method of producing mica prepreg insulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention 1] The present invention relates to a method for producing a novel mica prepreg insulator having excellent heat resistance and used for insulating electrical equipment. More specifically, when insulating electrical equipment wires and surrounding materials, the semi-cured state has excellent smoke storage stability, and the cured product has excellent heat resistance and
In particular, it concerns a method for manufacturing mica prepreg insulators with excellent electrical and mechanical properties at high temperatures.

[Prior art] The method of insulating electrical equipment using a semi-cured mica prepreg insulation sheet (including tape, hereinafter referred to as insulation sheet) does not require operations such as brushing or impregnation, so it reduces cost and manufacturing. This is an extremely effective method in terms of time. Conventionally, in the production of such insulating sheets, laminated mica paper alone or laminated mica paper with a backing material such as glass cloth nonwoven fabric, epoxy resin,
Moas using silicone resin and the like are widely used.

However, cured insulating sheets obtained using conventional epoxy resins are not fully satisfactory in terms of heat resistance, water resistance, etc., and their electrical properties are particularly poor in high temperature ranges. In addition, cured insulation sheets made using silicone resin have excellent thermal deterioration characteristics, but
Mechanical strength at high temperatures is extremely poor.

[Summary of the invention! ! ] As a result of extensive research in order to overcome the above-mentioned drawbacks, the present inventors have discovered a material that has excellent storage stability in a semi-cured state, and also has excellent heat resistance of the cured product, particularly in electrical and mechanical properties at high temperatures. We have discovered a method for manufacturing mica prepreg insulators that exhibit these properties, and have completed the present invention.

That is, the present invention provides 100 parts (parts by weight, hereinafter the same) of bismaleimide-triazine resin (hereinafter referred to as BT resin) having an average molecular weight of 500 to 3000, two or more (meth)acrylic groups or 5 to 300 parts of a polyfunctional monomer having an allyl group and a molecular weight of 15
72/xy resin 0.1 to 1 in the range of 000 to 80000
The present invention relates to a method for producing a prepreg insulator, which comprises coating or impregnating a base material with a prepreg resin composition containing 0 parts of the prepreg resin composition in a solvent type, and then heating and drying the composition to make it semi-cured.

The characteristics of the mica prepreg insulator according to the present invention are BTI (
BT [fat and polyfunctional By making the network of vinyl crosslinks formed from vinyl monomers compatible (uniform), high heat resistance and excellent electrical performance can be imparted to the cured BT resin product, and the crosslink density of the cured vinyl monomer product can be imparted. Furthermore, by adding 7enoxy resin as a high molecular weight component, a non-crosslinkable linear component is interposed in the crosslinked network, and the prepreg resin composition The objective is to provide visibility even when the material is cured.

[Embodiments of the invention] The BT resin used in the present invention has a molecular weight of 500 to 30.
Any number in the range 00 is acceptable, for example B
T-2160, BT-2170, BT-3109, BT
-3209, BT-3309, BT-3409C, Mitsubishi Gas Chemical (manufactured by Reiku, trade name), and the like, and these can be used alone or in combination.

Examples of the polyfunctional vinyl monomer having a (meth)acrylic group (meaning an acrylic group or a methacrylic group) or an allyl group in one molecule used in the present invention include diallyl phthalate, diallyl isoheptalate, triallyl trimellitate, and triallyl. Lewison annulate, bisphenol A diglycidyl ether di(meth)acrylate,
Examples include trimethylolpropane tri(meth)acrylate, trihydroxyethyl isocyanurate tri(meth)acrylate, and these can be used alone or in combination to reduce the weight.

The phenoxy resin used in the present invention has a molecular weight of 15,000 to
It can be used without particular limitation as long as it is within the range of 60,000. When the molecular weight is less than 15,000, the visibility imparting effect is insufficient, and when it exceeds 60,000,
The viscosity of the prepreg resin composition increases, which is unfavorable for work.

A polyfunctional vinyl monomer having a (meth)acrylic group or an allyl group in one molecule is
It is blended in a range of 5 to 300 parts. If the dose is less than 5 parts, the effects of adding the polyfunctional vinyl monomer (such as an increase in the degree of crosslinking) cannot be reversed, and if it exceeds 300 parts, the curing shrinkage rate becomes too low and the properties of the composition deteriorate. .

The amount of phenoxy resin blended is 0.1 to 10 parts per 100 parts of BT resin; if the dose is less than 0.1 part, the effect of imparting flexibility will not be sufficient, and if it exceeds 10 parts, it will not work at high temperatures. The electrical properties of the material deteriorate, which is not desirable.

In the present invention, a prepreg resin composition is prepared by blending BTI (fat), a polyfunctional vinyl monomer, and a phenoxy resin, but a catalyst may be further added for the purpose of promoting the reaction of the composition.

Examples of the catalyst include dicumyl peroxide,
Examples include vinyl polymerization initiation catalysts such as benzoyl peroxide, di-t-butyl hydroperoxide, and azobisisobutyronitrile.

In the present invention, the above-mentioned BTI (fat, polyfunctional vinyl monomer, phenoxy resin, catalyst used as necessary, etc.) is blended in the above proportions, for example, acetone,
After dissolving in an organic solvent such as toluene, ethyl alcohol, or an organic mixed solvent made by appropriately mixing these, and coating or impregnating the base material with this solution, the base material is
By heating and drying at 0° C. for 5 to 30 minutes, a semi-cured mica prepreg insulator can be obtained.

It is important that the base material has excellent heat resistance and electrical properties, and particularly preferred laminated mica paper such as unfired hard laminated mica paper, unfired soft laminated mica paper, or fired hard laminated mica paper It can be used alone or in combination with a backing material such as an inorganic fibrous base material (such as glass cloth), an organic fibrous base material, an organic nonwoven fabric (such as polyester nonwoven fabric), or a polyimide film.

The etched mica prepreg insulator is easily cured at 150 to 250°C, and the cured product has excellent heat resistance so that it can be used for a long time even at a high temperature of 220°C.

It also has extremely good mechanical and electrical properties at high temperatures.

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

Example I To 50 parts of BT-2170, 150 parts of triphthyrolpropane triacrylate, 0.3 parts of 72/xy resin having a molecular weight of about 30,000, and 0.0 parts of dicumyl peroxide.
A mica prepreg resin composition was prepared by blending 3 parts and dissolving them in a mixed solvent of acetone/toluene/ethyl alcohol in a volume ratio of 45/40/15. The obtained composition was coated on unfired hard laminated mica paper (manufactured by Ryobu Mica Co., Ltd., thickness 0.15 mm, basis weight 240 g/m2), and 1
It was dried by heating at 10°C for 10 minutes to obtain a mica prepreg insulator with a basis weight of 342 g/m''.

The storage stability of this mica prepreg insulator was investigated by the following method.

Next, add this mica prepreg insulator to 200am
Cut to size 00LII11 and overlap 20 pieces for 200 pieces.
A laminate with a thickness of about 311IL11 was produced by hot pressing at 10Kg/cm2X for 4 hours.

This laminate was further cut into 10 pieces with a size of 1 m x 10011 II11, and the bending strength at the initial stage and after 16 days at 220°C was measured based on JIS K 8911.

In addition, 7 sheets of mica prepreg insulator cut out to a size of 10100a 100m@ were heated and pressed in the same manner as above to produce a laminate with a thickness of about lInl1+, and JIS
The temperature characteristics of the dielectric loss tangent were measured using the Schering bridge method based on K6911.

Furthermore, the initial and 2 cm thick laminates obtained were
To examine the breakdown voltage after 16 days at 20°C, JAS K
6911 in oil at a constant pressure increase rate of IKV/see.

The above measurement results of storage stability, bending strength, dielectric loss tangent, and breakdown voltage are shown in Table 1. -, (Storage stability) Mica prepreg insulators are stored in a constant temperature and humidity chamber at 25°C and 35% relative temperature, and their softness, which is a necessary characteristic when wound into coils, etc., is determined according to JISC2103. Based on this, a bending test was conducted in which the prepreg insulator was bent along a round bar with a predetermined diameter to check for cracks, and observations were conducted at one-week intervals to measure the period until cracks appeared.

Example 2 To 60 parts of BT-3109, 20 parts of trihydroxyethyl isocyanurate triacrylate, 20 parts of trihydroxyethyl isocyanurate trimethacrylate
A mica prepreg resin composition was prepared by dissolving 0.5 parts of a phenoxy resin having a molecular weight of about 30,000 and benzoyl peroxide alcohol as a catalyst in a mixed solvent with a volume ratio of 45/40/15.

The obtained composition was coated on unfired hard laminated mica paper (manufactured by Ryobe Mica Co., Ltd., thickness 0.1a + m basis weight, 160 g/m2) and glass cloth (manufactured by Uwa Seisakusho Co., Ltd., thickness 0) as a backing material. Storage stability and bending strength were obtained in the same manner as in Example 1, except that the mica prepreg insulator was obtained by applying it to a base material using . (Initial, after 16 days at 220℃)
, dielectric loss tangent, and breakdown voltage (initial, after 16 days at 220° C.) were measured. The results are shown in Table 1.

Example 3 To 70 parts of BT-3209, 10 parts of triallyl trimellitate, 20 parts of trihydroxyethyl isocyanurate triacrylate, 3 parts of phenoxy resin with a molecular weight of about 30,000, and di-t-butylbaitropropylene as a catalyst. A mica prepreg resin composition was prepared by blending 0.5 part of oxide and dissolving it in a mixed solvent of acetone/toluene in a volume ratio of 55/45.

The resulting composition is fired into hard laminated mica paper (both parts mica (
Co., Ltd., thickness 0.1 mm, basis weight 160 g/m") and a polyimide film (manufactured by DuPont, thickness 0.1 mm) as a backing material.
025mff1, trade name: Kapton ■) was coated on a base material using Kapton ■), and heated and dried at 120°C for 10 minutes to form a mica prepreg insulator. The dielectric loss tangent (initial stage, after 16 days at 220°C), dielectric loss tangent, and breakdown voltage (initial stage, after 16 days at 220°C) were measured. The results are shown in Table 1.

Comparative Example I To 20 parts of BT-2170, 80 parts of diallyl iso7 tallate, 15 parts of phenoxy resin with a molecular weight of about 30,000, and 0.4 parts of dicumyl peroxide as a catalyst were blended, and the volume ratio of acetone/toluene/ethyl alcohol was So 4
A mica prepreg resin composition was prepared by dissolving it in a mixed solvent of 5/40/15/.

The resulting composition was coated with unfired soft laminated mica paper (manufactured by Ryobe Mica Co., Ltd., thickness O', 15 mm, basis weight 240 g, /m2
) and heated and dried at 110°C for 10 minutes to obtain a mica prepreg insulator, but in the same manner as in Example 1.
Storage stability, bending strength (initial, after 16 days at 220°C)
, dielectric loss tangent, breakdown voltage (initial, 16 days f& at 220°C)
was measured. The results are shown in Table 1.

Comparative Example 2 For comparison with conventional mica prepreg insulators, 80 parts of DE438 (manufactured by Dow Chemical Company) and 20 parts of Epikote 834 (IJ, Shell Chemical Company) were used as epoxy resin components, and 2 parts of boron trisulfide monoethylamine as a catalyst. A mica prepreg resin composition was prepared by dissolving acetone/toluene/ethyl alcohol in a mixed solvent with a volume ratio of 45/40/15.

The obtained composition was applied to unfired hard laminated mica, and 11
Storage stability bending strength (initial,
After 16 days at 220℃), dielectric loss tangent, breakdown voltage (initial, 2
(After 16 days at 20°C) was measured. , the results are shown in Table 1.

[Margin 1 below] Table 1 [Margin below] From the results in Table 1, the characteristics of the mica prepreg insulator or its cured product according to the present invention are as follows: Compared to the case of Comparative Example 1, which has a larger number of cases, or the case of Comparative Example 2, which is a conventional prepreg insulator, the storage stability is excellent, and the bending strength, dielectric loss tangent, and breakdown voltage are also very high and good. It can be seen that it is.

Examples 4 to 6 The three types of mica prepreg resin compositions obtained in Examples 1 to 3 were applied to unfired hard laminated mica paper (Ryobe Mica Co., Ltd.).
It was applied to a base material using a polyester nonwoven fabric (manufactured by Nippon Vilene Co., Ltd., thickness 0.025 mm, basis weight 20 g/m2) as a backing material. Mica prepreg scales were obtained by heating and drying at C for 10 minutes. Next, in order to investigate the characteristics of the three types of mica prepreg chips that were cut into medium 19 mm pieces and used for insulating coils, 2 mm x 5 mm x 500 m.
10 m double glass-wound rectangular copper wire combined in 2 rows and 5 tiers
After winding the coil conductor with a cross section of ff1m10ff1+ five times in half layers, inserting it into a mold and heating it at 150℃
After heat-pressing molding at 20 kg/cm2 for 6 hours, polymerization was further carried out at 200℃ for 16 hours to obtain three types of insulated coils. Voltage characteristics (5KV/m+
a - 0.5 KVm)) t (and the breakdown voltage was measured by the same method as in Example 1. The results are shown in Table 2.

[Margin below 1 Table 2 [Effects of the invention] The mica prepreg insulator according to the present invention has a storage stability of 6.
The cured product has excellent heat resistance, especially electrical and mechanical properties at high temperatures.

Claims (5)

[Claims] (1) 5 to 300 parts by weight of a polyfunctional vinyl monomer having two or more (meth)acrylic groups or allyl groups in one molecule and molecular weight for 100 parts by weight of bismaleimide-triazine resin having an average molecular weight of 500 to 3,000. 1
Phenoxy resin 0.1 to 5000 to 60000
A method for producing a mica prepreg insulator, which comprises coating or impregnating a base material with a prepreg resin composition containing 10 parts by weight in a solvent type, and then heating and drying it to a semi-cured state. (2) Claim No. 1, wherein the base material is laminated mica paper or a combination of laminated mica paper and a backing material.
Manufacturing method described in section. (3) The manufacturing method according to claim (1) or (2), wherein the laminated mica paper is an unfired hard laminated mica paper, an unfired soft laminated mica paper, or a fired hard laminated mica paper. (4) Claim No. 1, wherein the backing material is an inorganic fibrous base material, an organic fibrous base material, or an organic nonwoven fabric.
or (2). (5) The first heat drying is heat drying at a drying temperature of 80 to 130°C and a drying time of 5 to 30 minutes.
The manufacturing method described in section 1).