JPS62180914A - Composite film for electrical insulation - 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 [Field of Industrial Application] The present invention relates to an electrically insulating composite film with excellent heat resistance and the like used in the electronic field.

[Conventional technology] Flexible printed circuit boards, various electric motors,
Polyimide films, aromatic polyamide papers, polyester films, and the like are known as electrical insulation films used in transformers, generators, and the like. However, although polyimide films have excellent heat resistance, they have problems such as high water absorption and poor alkali resistance.

In addition, aromatic polyamide paper has problems such as high water absorption and insufficient mechanical strength, while polyester film also has problems such as low heat resistance.

[Problems to be solved by the invention] In order to solve the above problems, a fibrous insulating base material is used,
A composite film made by combining 1 chu and 8 jus is considered. Although the use of a heat-resistant resin such as 2-polyimide as the resin is satisfactory in terms of electrical properties, it does not go far in solving the problems inherent in the polyimide described above. This heat-resistant resin must not only be relatively inexpensive and have excellent mechanical properties, but also have sufficiently low dielectric constant and dielectric loss. Moreover, it is necessary to have high heat resistance, and it is desirable that other properties such as chemical resistance and low water absorption are also sufficiently high. Furthermore, it is desirable that the fibrous insulating base material also has excellent electrical properties.

Means for Solving Problem E] In order to solve the above problem, the inventor of the tree researched and considered the combination of an M&fiber insulating base material and a heat-resistant resin, and found that an aromatic polythioether sulfone polymer or It has been found that the cured product is a resin that is extremely suitable for this use, and that a material containing fluorine-containing resin fibers is suitable as the base material. The present invention is a composite film of this kind, that is, a film for insulation made of an aromatic polythioethersulfone polymer or a cured product thereof and a fibrous insulating base material containing fluorine-containing resin fibers.

The aromatic polythioether sulfone polymer in the present invention refers to an aromatic polythioether sulfone homopolymer or an aromatic polythioether sulfone copolymer. Among these, homopolymers (those in which m is O in the general formula below)
JP-A-47-13347, JP-A-53-25
It is disclosed in Japanese Patent Publication No. 879 and Japanese Patent Publication No. 53-25880, and is known as a thermoplastic resin having excellent mechanical properties at high temperatures.

As the copolymer, various copolymers having a thioether sulfone residue and another bifunctional residue having an aromatic nucleus can be used.6 In particular, a copolymer represented by the following general formula (m
is not O), and this copolymer is described in Japanese Patent Application No. 59-193968, Japanese Patent Application No. 196723-1982, and Japanese Patent Application No. 8386-1988, which were invented by the present inventors. It is a thermoplastic resin with excellent mechanical properties at high temperatures that can be obtained by this method.

The aromatic polythioether sulfone polymer in the present invention has a hydrocarbon group represented by the following general formulas 1 to 8, which may be the same or different from each other, where ae is θ~4 and flg is 0.
-3 integers which may be the same or different; R represents hydrogen or a hydrocarbon group having 1 to B carbon atoms; m and n satisfy the range of 0≦m/m+n<1. m
When ~0, is it polythioether sulfone? It is an n-polymer. ) An aromatic polythioethersulfone polymer represented by the following is particularly preferred. Among these, copolymers in which m is not 0 are, for example, dihalodiphenylsulfones having a /\logen atom such as a chlorine atom in the para or ortho position of each aromatic nucleus, and dihalodiphenyl sulfones having a /\logen atom such as a chlorine atom at the para or ortho position of each aromatic nucleus, Obtained by reacting phenols and alkali total sulfides. In this reaction, alkaline hydroxides and carbonates are used as dehalogenating agents, but diphenols can also be used in advance in place of the corresponding alkaline phenoxides. This reaction can of course be carried out in one stage, but also in a multistage method using a precursor.

Furthermore, the cured product of the aromatic polythioethersulfone polymer in the present invention is a three-dimensionally crosslinked cured product obtained by crosslinking the aromatic polythioethersulfone polymer as described above. As the crosslinking agent, epoxy compounds having at least two epoxy groups in one molecule (ie, so-called epoxy resins), aminoblast resins, or metal acetylacetonates are preferred. This crosslinking agent is mixed with an aromatic polythioethersulfone polymer,
A cured product is obtained by heat treatment.

As the above-mentioned epoxy compound, a liquid or solid one can be used, and a partial polymer (prepolymer) can also be used. Examples of such epoxy compounds include bisphenol A, resorcinol, hydroquinone, pyrocatechol, bisphenol F, bisphenol S, bisphenol AF, 1,3.5-hydroxybenzene, trihydroxy-diphenyldimethylmethane, 4.
Glycidyl ethers such as 4'-dihydroxybiphenyl, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, and halogenated glycidyl ethers thereof; butanediol.

Glycidyl ethers such as glycidyl ethers such as glycerin, glycidyl esters such as phthalic acid glycidyl esters, aniline, diaminobenzene, benzidine, methylene dianilidiaminocyclohexane, incyanuric acid, aminocyclohexane, diaminodiphenylsulfone, diaminonaphthalene, xylylene di amine,
Cyclohexane bismethylamine.

Glycidyl epoxy resins such as glycidylamine series such as melamine; epoxidized olefins.

Examples include linear non-glycidyl epoxy resins such as epoxidized soybean oil and cyclic non-glycidyl epoxy resins such as vinylcyclohexene dioxide and dicyclopentadiene dioxide; novolac type epoxy resins and halogenated products thereof.

Aminoplast resins are aldehyde condensates of melamine, urea, guanamine, their analogs, and aliphatic or aromatic polyamino compounds.

Here, examples of the aliphatic polyamino compound include ethylenediamine, trimethylenediamine, tetramethylenediamine, 1,2-diaminopropylenediamine, 1,4-diaminocyglohexane, and 1°4-diaminocyclohexylmethane.

Also・1. Examples of aromatic polyamino compounds include
C, P-phenylenediamine, m-phenylenediamine, 0-phenylenediamine, 2.4-tolylene a,
amine, P-aminomethylamine, P-xylylenediamine, m-xylylenediamine, benzidine, 4.4
'-Diaminodiphenylmethane.

Examples include 4,4-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl sulfide.

Among these, compounds obtained by reacting melamine, urea, or benzo:guanamine with formalde and humans are the most well known and can be cited as the most preferably used.

Similar condensation products can be obtained by using other aldehydes such as a7toaldehyde, crotonaldehyde, acrolein, benzaldehyde, and furfural in addition to formaldehyde. .

The above amine-aldehyde condensation products may have alkylol groups such as methylol, and in many cases,
At least a part of it can be etherified by reaction with alcohol to obtain a resin soluble in organic solvents.

Methanol, ethanol, and furfural for this purpose.

Butanol, pentanol, hexanol, other 1
Including alcohols, aromatic alcohols such as pen and di alcohol, alicyclic alcohols such as cyclohexanol, glycol monoethers such as cellosolve, halogen substitutions such as 13-chloropropanol,
Other substituted alcohols may be used.

Among these ethers, it is preferable to use amine-aldehyde resins etherified with methanol or butanol.

The amount of the epoxy compound and aminoblast resin added above is the aromatic polythioether sulfone polymer + (1
The amount is 0.5 to 50 parts, preferably 1 to 20 parts.

If the amount is less than this, curing will be insufficient, and if it is more than this, unreacted epoxy compounds and amineplast resins will remain, which is not preferable because mechanical or thermal properties will deteriorate. Two or more of these epoxy compounds and aminoblast resins may be used in combination within a suitable addition amount range.

When these crosslinking agents are used, the curing temperature in the heat treatment is usually between 150 and 400°C, preferably 7 g or more of the aromatic polythioethersulfone polymer.
The temperature is preferably 350°C or less.

If it is lower than this, the curing speed will be slow, and if it is higher than this, a decomposition reaction will occur, which is not preferable. The curing time varies depending on the temperature, but it can usually be cured in about 5 minutes to 10 hours.

In addition, the metal acetylacetonate in the present invention has a different mechanism of action from the crosslinking agent having a crosslinking group as described above; it radically decomposes upon heating to generate active radicals, and these radicals are used to generate aromatic nuclei, etc. It is thought that this causes oxidative crosslinking. Metal acetylacetonate is
This is a metal chelate compound of acetylacetone. Examples of such compounds include Group 1A (1) of the periodic table, and Group 1A (2) of the periodic table.
) Group 1IA, (3) Group 1UB.

(4) Group 1 VB, (5) Group VB, (6) Group VIB)
Greetings.

(7) Group ■B, (8) Group 1B, (9) Group 1B.

(10) Group IB, (II) Group mA, (12
) each acetylacetonate of the lanthanide group is preferred.

Here, each of the above acetylacetonates (hereinafter acac
(1) Group 1A aCaC is Cs (I) a
cac(2) The first IA group aCaC is Mg(I
I).

Ca(II), Sr(II)acac(3)
Group 1A aCaC includes La (III) aca
c(4) The first VB group acac is [Ti (
[)acac]2Tic16. Zr (IV),
ZrO (II) acac (5) No. VBJj1jac
As ac, l/(III) acac(6) 1st A
Group aCaC includes Cr(III).

Mo (m)acac (7) Group 1A aCaC is Mn(II).

Mn(IU), Re(III)acac(8
) Group Ⅰ aCaC is Fe(III).

Go (II), Go (m), R
h (III).

Ni (II) acac (9)ffi'IB group acac includes Cu (II
) acac (10) The first IB group acac is Zn(II).

Cd (II) acac (11) As the 1st IA group acac, AI (m)
.

IA ('H)TI (I)acac(12) Lanthanoid aCaC is Ce(Ill).

Sm (III), Gd (m), Er (m
).

Examples include Tm (m), Lu (m) acac, and the like.

In such acac, particularly preferred is Cu(H)
, Mouth (II), Mn (III), Fe (m
).

Go(II), Ni(II), , AI(
m), a c'a c such as Zr+(II).

The -h1 of the metal acetylacetonate added to the aromatic polythioethersulfone polymer is 0.05 to 10% by weight, or 0.1 to 10% by weight, based on the total amount of the polymer.
It is in the range of 5% by weight, and is effective even in extremely small amounts. In addition, when using this crosslinking agent, the curing temperature in the heat treatment is usually between 150 and 400°C, and preferably 7 g or more of the aromatic polythioether sulfone polymer.
The temperature is preferably 350°C or lower. If it is lower than this, the curing speed will be slow, and if it is higher than this, a decomposition reaction will occur, which is not preferable.

The curing time varies depending on the temperature, but it can usually be cured in about 5 minutes to 10 hours.

As the fibrous insulating base material containing fluorine-containing resin fibers, fibrous insulating base materials containing various fluorine-containing resin fibers as raw materials can be used. Particularly preferred are cloths and nonwoven fabrics containing polytetrafluoroethyln polymer fibers. Particularly preferred is a fiber base material such as a cloth containing substantially only polytetrafluoroethylene polymer fibers.

The fibrous insulating base material and the aromatic polythioethersulfone polymer are usually formed into a composite by impregnating the base material with a solution of the aromatic polythioethersulfone polymer and removing the solvent. However, the method is not limited to this, and a method of heating and pressurizing a polymer powder in the presence of the base material to impregnate it, or a method of impregnating and integrating a molten polymer into the base material under pressure may be adopted. You can also do that. In addition, when producing a composite film of a cured product of an aromatic polythioethersulfone-based polymer, after compounding the mixture of the aromatic polythioethersulfone-based polymer and a crosslinking agent with the m-part insulating base material, A method of crosslinking the aromatic polythioethersulfone polymer under the crosslinking conditions described above is employed.

For example, the base material is impregnated with a solution containing both a polymer and a crosslinking agent, the solvent is removed, and crosslinking is performed by heating to the above-mentioned crosslinking temperature to obtain the desired composite film.

EXAMPLES The present invention will be specifically illustrated below with reference to Examples, but the present invention is not limited to these in any way.

Examples Example 1 4,4'-dichlorodiphenylsulfone and sodium sulfide were added to a precursor obtained by reacting 4.4'-dichlorodiphenylsulfone, bisphenol A, and sodium hydroxide. , an aromatic polythioether sulfone polymer represented by the following formula was obtained (
For details, see the above-mentioned Japanese Patent Application No. 8386/1986).

m/n=l0/1 η1nh=o, 45; 30°0.0.5 in PhOH/1,1,2.2-tetrachloroethane 3/2 (weight ratio)
Measured in g/di A varnish was prepared by dissolving 50 g of this polymer and 2 g of hexamethoxymethylmelamine in 300 g of 1,1,2,2-tetrachloroethane. This varnish was applied to a polytetrafluoroethylene fiber cloth (density 93 x 93 fibers/inch, weight 95 g/m') with a thickness of 120 μm,
280℃ after drying at 100℃ for 1 hour.
A composite film with a thickness of 150 μm and a resin content of 60% was obtained by heat treatment at °C for 1 hour. Table 1 shows the physical properties of this composite film.

Example 2 N, N, N' instead of hexamethoxymethylmelamine
The polytetrafluoroethylene fiber cloth used in Example 1 was impregnated with a varnish prepared in the same manner as in Example 1 except that N'-tetraglycidyl-m-xylylene diamine was used. dried and crosslinked to a thickness of 15
A composite film with a diameter of 0 μm and a resin content of 60% was obtained. Table 1 shows the physical properties of this composite film.

Example 3 In Example 1, 4,4' instead of bisphenol A
-Dihydroxydiphenyl was used to produce the following copolymer in a similar manner.

(a+/n=1/1, η1nh=0.82) 50 g of this polymer, 2.5 g of hexamethoxymethylmelamine
g was dissolved in 320 g of 1.1,2.2-tetrachloroethane to prepare a varnish. This vanipe □ was impregnated into a polytetrafluoroethylene fiber cloth in the same manner as in Example 1, and □ dried. A composite film having a thickness of 160 μm and a resin content of 70% was obtained by crosslinking.

The physical properties of this composite film are shown in Table 1.

Example 4 50 g of the copolymer produced in Example 3, C,:u(aca
c) 20.5g to 250g N-methyl-2-pyrrolidone
to prepare a varnish. The polytetrafluoroethylene fiber cloth used in Example 1 was impregnated with this varnish, dried and heat treated in the same manner as in Example 1, and the thickness was 145 mm.
μm, a composite film with a resin content of 65%? Ta. Table 1 shows the physical properties of this composite film.

Comparative Example 1 A varnish prepared in the same manner as in Example 1 was cast onto Glass No. 1 (plate) with a doctor blade and subjected to the same drying and heat treatment steps as in Example 1 to obtain a film with a thickness of 50 μm. This film Table 1 shows the '+h properties of .

Comparative Example 2 Polyimide film (“Cub”) with a thickness of 50 μm
The physical properties of the sample (manufactured by DuPont) were determined. The results are shown in Table 1.

Comparative Example 3 The physical properties of a 50 μm thick polymetaphenylene isophthalamide paper (“Nomex 410°” manufactured by Duyupoff Co., Ltd.) of rff IIM were measured. The results are shown in Table 1.

[Effects of the Invention] A composite film comprising the aromatic polythioethersulfone polymer or its cured product of the present invention and a fibrous insulating base material containing fluororesin fibers has excellent dielectric properties, and
1゜ is an excellent electrical insulation film that has high heat resistance, high chemical resistance, low water absorption, and mechanical strength that is sufficient for practical use.

Claims (1)

[Scope of Claims] 1. A composite film for electrical insulation comprising an aromatic polythioethersulfone polymer or its cured product and a fibrous insulating base material containing fluorine-containing resin fibers. 2. The cured product of an aromatic polythioethersulfone polymer is an aromatic polythioethersulfone polymer, an epoxy compound having at least two epoxy groups in one molecule, an aminoplast resin, or a metal acetylacetonate. A hardened product obtained by mixing and heat-treating,
The film according to claim 1. 3. The film according to claim 1, wherein the fluorine-containing resin fiber is a polytetrafluoroethylene polymer fiber.