JPH0410890B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an electrically insulating material, and more particularly to an electrically insulating material that is transparent and has excellent electrical properties. [Prior art and problems to be solved by the invention] Conventionally, cured products of compositions consisting of diene polymers such as hydroxyl group-containing liquid polybutane diene and polyisocyanates such as diphenylmethane diisocyanate have been used as electrical insulating materials. is known. However, since this material has poor transparency, it is difficult to visually check the wiring state when used for a printed circuit board. There was also room for improvement in electrical properties such as volume resistivity. Therefore, the present inventors conducted intensive research to develop an electrically insulating material that solved these problems, and as a result, they completed the present invention. [Means for Solving the Problems] That is, the present invention comprises (A) a hydroxyl group-containing liquid diene polymer (hereinafter referred to as component (A)), (B) a polyisocyanate compound (hereinafter referred to as component (B)). ) and (C)
As described later, an electrical insulating material (hereinafter referred to as the first (referred to as an invention).
and an electrical insulating material (hereinafter referred to as the second invention) made by further blending (D) petroleum resin (hereinafter referred to as (D) component) to these components (A), (B), and (C). . First, the first invention will be explained. The hydroxyl group-containing liquid diene polymer, component (A) of the present invention, has hydroxyl groups in the molecule, preferably at the end of the molecule, and has a number average molecular weight of 300 to 25,000, preferably
500 to 10,000, and the hydroxyl group content is 0.1 to 10 meq/g, preferably 0.5 to 5 meq/g.
It is g. These liquid diene polymers include diene polymers and diene copolymers having 4 to 12 carbon atoms, and also combinations of these diene monomers with α-carbon atoms having 2 to 22 carbon atoms.
Examples include copolymers with olefinic addition polymerizable monomers. Specifically, butadiene homopolymer,
Isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer,
Examples include butadiene-2-ethylhexyl acrylate copolymer and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be produced, for example, by subjecting a conjugated diene monomer to a heating reaction in a liquid reaction medium in the presence of hydrogen peroxide. The polyisocyanate compound which is the component (B) of the present invention is an organic compound having two or more isocyanate groups in one molecule, and which reacts with the hydroxyl group of the hydroxyl group-containing liquid diene polymer of the component (A). It has a natural isocyanate group. Examples of polyisocyanate compounds include the usual aromatic, aliphatic and cycloaliphatic ones, such as tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate (MDI), liquid modified diphenylmethane diisocyanate. , polymethylene polyphenyl isocyanate, xylylene diisocyanate, cyclohexyl diisocyanate, cyclohexane phenylene diisocyanate, naphthalene-1,5-
Diisocyanate, isopropylbenzene-2,
Examples include 4-diisocyanate, an addition reaction product of polypropylene glycol and tolylene diisocyanate, and particularly preferred are MDI, liquid modified diphenylmethane diisocyanate, and tolylene diisocyanate. Next, the polycyclic aromatic hydrocarbon which is component (C) has the general formula and general formula At least one type of polycyclic aromatic hydrocarbon selected from the compounds represented by is used. In general formulas () and (), R ¹ , R ² , R ³ , R ⁴ ,
R ⁵ , R ⁶ , R ⁷ and R ⁸ represent a hydrogen atom or a lower alkyl group. Here, the lower alkyl group is an alkyl group having about 1 to 5 carbon atoms, and includes a methyl group,
Examples include ethyl group, propyl group, t-butyl group, and the like. R ¹ to R ⁸ may be the same or different. Moreover, n represents an integer of 1 to 3. Specific examples of polycyclic aromatic compounds are shown below. Polycyclic aromatic compounds may be used alone or in combination of two or more. There is no particular restriction on the blending amount of the above three components constituting the electrical insulating material of the first invention, but usually 0.1 to 500 parts by weight of component (B), preferably 1 to 200 parts by weight of component (B) per 100 parts by weight of component (A). parts by weight, component (C) 10 to 1000 parts by weight,
Preferably it is 30 to 500 parts by weight. If the amount of component (B) is outside the above range, sufficient curing will not occur. Furthermore, if the amount of component (C) is less than 10 parts by weight, the cured product will not have transparency, and if it exceeds 1000 parts by weight, the strength will be insufficient. The electrically insulating material is obtained by blending predetermined amounts of each component, kneading, and curing. Curing is usually 0
It is carried out at ~200°C, preferably 10-150°C, for 0.5-180 minutes, preferably 5-60 minutes. In this case, it is desirable to first mix components (A) and (C), then add component (B), knead, and cure. Next, the second invention will be explained. In order to improve the mechanical properties of the electrically insulating material of the first invention, the electrically insulating material of the second invention is a material containing component (D) in addition to the components (A), (B), and (C) above. . Components (A), (B) and (C) are the same as those explained in the first invention. The petroleum resin, which is component (D) of the present invention, is a distillation residue oil (mixture of various components) obtained by recovering aromatic compounds from cracked gasoline, which is a by-product during the production of ethylene by thermal decomposition of naphtha, etc. It is a rosin-like resin obtained by polymerization using a catalyst. The petroleum resin preferably has a softening point of about 40 to 200°C. The above (A), (B) constituting the electrically insulating material of the present invention,
There is no particular restriction on the blending ratio of components (C) and (D), but usually 0.1 to 500 parts by weight, preferably 1 to 200 parts by weight of component (B) to 100 parts by weight of component (A),
Component (C) 10 to 1000 parts by weight, preferably 30 to 500 parts by weight, Component (D) 10 to 1000 parts by weight, preferably 30 to 500 parts by weight
Parts by weight. The reason why it is undesirable for the blending amounts of component (B) and component (C) to be outside the above range is as follows.
This is as explained in the invention. If component (D) is less than 10 parts by weight, excellent mechanical properties will not be obtained;
Moreover, if it exceeds 1000 parts by weight, the rubbery properties will be poor and the product will lack flexibility. The electrically insulating material of the second invention can be manufactured in the same manner as the first invention. In this case, first
It is desirable to mix component (A), component (C) and component (D), then add component (B), knead and cure. [Effects of the Invention] As described above, the electrical insulating materials according to the first and second inventions are usually formed as a plate-shaped cured body,
Used as an electrical insulation material for IC printed circuit boards, IC potting materials, transformer impregnated varnish, capacitor coil impregnated varnish, etc. The electrical insulating material of the present invention has excellent transparency, which makes it easy to visually check the wiring state of printed circuit boards, the state of parts, the coating state, etc., and has good electrical properties such as volume resistivity. The material of the second invention also has excellent mechanical properties and can be used extremely effectively as an electrical insulating material. [Example] Next, the present invention will be explained in detail with reference to Examples. Examples 1 and 2 The hydroxyl group-containing liquid diene polymer shown in Table 1 and the polycyclic aromatic hydrocarbon were placed in a 300 ml separable flask and heated and stirred at 60° C. and 1 mmHg for 1 hour to remove water. Then, after cooling to 25℃
The polyisocyanate compound melted at 60°C was quickly added while stirring, and the mixture was heated and stirred at 25°C for 2 hours. The mixture is then cooled to room temperature and formed to a thickness of 2
The mixture was poured into a sheet mold with a diameter of 1.5 mm and cured in a humidifier at 23° C. and 60% humidity for two weeks to produce a sheet molded product. The physical properties of this sheet were measured. The results are shown in Table 1. Example 3 Hydroxyl group-containing liquid diene polymer shown in Table 1,
Polycyclic aromatic hydrocarbon and petroleum resin in Example 1,
After the same treatment as in Example 2, a polyisocyanate compound was added in the same manner as in Examples 1 and 2, and the mixture was heated and stirred. Thereafter, a sheet molded product was obtained in the same manner as in Examples 1 and 2. Table 1 shows the measurement results of the physical properties of this sheet. Comparative Example 1 The same procedure as in Examples 1 and 2 was carried out except that no polycyclic aromatic hydrocarbon was added. The results are shown in Table 1.

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Claims (1)

[Claims] 1 (A) hydroxyl group-containing liquid diene polymer, (B) polyisocyanate compound, and (C) general formula [formula] and general formula (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and
R ⁸ each represents a hydrogen atom or a lower alkyl group. However, R ¹ to R ⁸ may be the same or different. Moreover, n represents an integer of 1 to 3. ) at least one selected from the compounds represented by
Electrical insulating material consisting of various polycyclic aromatic hydrocarbons. 2 (A) hydroxyl group-containing liquid diene polymer, (B) polyisocyanate compound, and (C) general formula [formula] and general formula (In the formula, R ¹ , R ² , R ³ .R ⁴ , R ⁵ , R ⁶ , R ⁷ and
R ⁸ each represents a hydrogen atom or a lower alkyl group. However, R ¹ to R ⁸ may be the same or different. Moreover, n represents an integer of 1 to 3. ) at least one selected from the compounds represented by
An electrical insulating material consisting of a variety of polycyclic aromatic hydrocarbons and (D) petroleum resin.