JPS6336329B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION This invention relates to curable polymer compositions. Polyhydroxy hydrocarbon polymers are used as materials for polyurethane elastomers, which have excellent electrical insulation and water resistance. Among polyhydroxy hydrocarbon polymers, polyhydroxy hydrocarbon polymers with a saturated main chain not only have excellent electrical insulation and water resistance, but also have excellent mechanical properties, heat resistance, weather resistance, etc., and are used as polyurethane elastomer materials. It can be said to be a useful ingredient. However, when used in potting materials, etc., when used in combination with liquid diphenylmethane diisocyanate, which is the easiest to handle and is used in large quantities as a hardening agent, there is a problem that the pot life is relatively short and it is difficult to work with. It was hot. A composition consisting of a polyhydroxy hydrocarbon polymer and a compound in which a highly reactive isocyanate group is blocked with an active hydrogen atom-containing compound such as a phenol compound is stable at room temperature, but it hardens when heated, making it difficult to work with. Very good. However, when such a blocked polyisocyanate compound is used for curing, the blocking agent remains in the cured product, which has a disadvantage in that it adversely affects the electrical properties, heat resistance, etc. of the cured product. As a result of intensive research to solve these problems, the present inventors found that by adding and blending a specific polyisocyanate compound as a curing agent, it is stable for a long period of time at low temperatures and is resistant to heating. The present inventors have discovered that a curable polymer composition can be obtained which, when cured, provides a urethane elastomer with excellent electrical and mechanical properties. That is, the gist of the present invention is (A) a saturated or mostly saturated hydrocarbon polymer having at least 1.5 hydroxyl groups per molecule; and (B) a 4,4'-
dicyclohexylmethane diisocyanate, 3,
A curable polymer composition comprising at least one polyisocyanate compound selected from 3'-dimethylbiphenylene-4,4'-diisocyanate and N,N',N''-tris(6-isocyanatehexamethylene)biuret. Next, the present invention will be explained in more detail. The main chain-saturated or mostly saturated hydrocarbon polymer having at least 1.5 hydroxyl groups per molecule used in the present invention [hereinafter, this (referred to as component (A)) is 400~
Those having a number average molecular weight (by vapor pressure method) of 48,000, preferably in the range of 500 to 20,000 are used.
If the number average molecular weight is too small, the weather resistance will not be sufficient, and if it is too large, the fluidity will decrease, making handling difficult. The average number of hydroxyl groups per molecule is
1.5 or more, preferably 1.8 or more, particularly preferably 2.0 or more
It is 5.0. The hydroxyl group is preferably located at the end of the main chain or at the end of a long chain branch. However, such component (A) can be obtained by hydrogenating a butadiene-based liquid polymer obtained by radical polymerization of butadiene alone or with a copolymerizable monomer using a known method such as hydrogen peroxide as a polymerization initiator. You can get it by twisting it. Examples of copolymerizable monomers include isoprene, chloroprene, styrene, methyl (meth)acrylate, and methyl vinyl ether. Hydrogenation is carried out in a conventional manner using a nickel catalyst (eg reduced nickel, Raney nickel), cobalt catalyst, platinum catalyst, palladium catalyst, rhodium catalyst, ruthenium catalyst, or a mixture or alloy catalyst thereof. Note that a part of component (A) can also be replaced with other polyols. Examples of other polyols include polyalkylene oxides such as polyethylene glycol and polypropylene glycol, polytetramethylene glycol, polycaprolactone polyol, castor oil, lower polyols such as phenyldiisopropanolamine, ethylene glycol, tetramethylene glycol and trimethylolpropane. Examples include polyols. The polyisocyanate compound [hereinafter referred to as component (B)] used in the present invention is 4,4'-dicyclohexylmethane diisocyanate.

[Formula] (where

[Formula] represents a cyclohexylene group) 3,3-dimethylbiphenylene-4,4'-diisocyanate

[Formula] and N,N′,N″-tris(6-isocyanatehexamethylene)biuret It is. These can be used alone or in combination. The mixing ratio of components (A) and (B) is the equivalent ratio of isocyanate groups in component (B) to hydroxyl groups in component (A), which is 0.8.
It is preferable to set it in the range of ~1.6. This is because if it is outside this range, curing will not proceed completely or the mechanical properties will be poor. The composition of the present invention can be obtained by various well-known means. For convenience, simply place components (A) and (B) in a suitable container and mix well. The composition of the present invention obtained as described above has 70%
It can be easily cured by heating between ℃ and 200℃. Note that during such curing, a reaction accelerator may be added to the composition in advance so that the reaction proceeds smoothly. As such a reaction accelerator, tertiary amines such as triethylamine, triethylenediamine, and dimethylaminoethanol, and organometallic compounds such as dimethyltin diacetate and dibutyltin dilaurate are preferred. The composition of the present invention can be modified in strength, elongation, etc. by adding fillers such as silica, hydrated silica, clay, talc, calcium carbonate, magnesium carbonate, carbon black, organic fiber, and glass fiber. It can be carried out. In addition to the additives mentioned above, when carrying out the present invention, conventionally known additives used in the urethane industry such as foam stabilizers, flame retardants, crosslinking agents, etc. can be used as necessary. . Therefore, the cured product of the composition of the present invention as described above has both excellent electrical insulation properties and excellent mechanical properties, and is suitable as an electrical insulation material. In addition, the cured product has good low temperature properties,
It has rubber elasticity comparable to that of general-purpose synthetic rubber, as well as excellent hydrolysis resistance and good casting moldability, making it more advantageous as an electrical insulating material. Next, examples of the present invention and production examples (reference examples) of raw materials for the composition of the present invention will be described, but the present invention is not restricted by these examples unless the gist of the present invention is exceeded. In addition, in Examples and Comparative Examples, the mechanical properties, hardness, tensile strength, elongation, etc. of the cured products are in accordance with JIS K-6301.
According to JIS K-6911, electrical properties such as dielectric loss tangent, dielectric constant, and individual volume resistivity as an electrical insulating material are determined according to JIS K-6911.
Each measurement was performed at 60Hz according to the following. Reference Example 1 (Production of hydrogenated product of unsaturated hydrocarbon polymer having a hydroxyl group at the end) Commercially available polyhydroxypolybutadiene [manufactured by Arco; R
-45HT, number average molecular weight Mn; 3110, OH group;
0.82meq/g, cis-1,4; 15%, trans-
1,4: 58%, vinyl: 27%] 3 kg, cyclohexane 3 kg and carbon-supported ruthenium (5%) catalyst (manufactured by Nippon Engelhard Co., Ltd.) 300 g,
After replacing the inside of the system with purified argon gas, high-purity hydrogen gas was supplied to the autoclave and heating was started at the same time.
100°C and an internal pressure of approximately 50 Kg/cm ³ ). After maintaining this condition for about 15 hours, the hydrogenation reaction was stopped and
The polymer was purified and dried according to a conventional method. As a result of analysis by infrared absorption spectrum, the obtained polymer was confirmed to be a saturated hydrocarbon polymer containing almost no double bonds. Moreover, the -OH group content of the hydrogenated product was 0.8 meq/g. Reference Example 2 (Production of hydrogenated product of unsaturated hydrocarbon polymer having a hydroxyl group at the end) In Reference Example 1, polyhydroxystyrene-butadiene copolymer [manufactured by Arco; CS] was used instead of polyhydroxypolybutadiene. -15,
A hydrogenated product was produced in the same manner as in Reference Example 1, except that a number average molecular weight of 2800 and an OH group of 0.68 meq/g were used. As a result of analysis by infrared absorption spectrum, the obtained hydrogenated product was confirmed to be a saturated hydrocarbon polymer containing almost no double bonds. Further, the OH group content of the hydrogenated product was 0.671 meq/g. Examples 1 to 3 and Comparative Examples 1 to 3 The hydrogenated product of the unsaturated hydrocarbon polymer having a hydroxyl group at the end obtained in Reference Example 1 and the polyisocyanate compound shown in Table 1 were mixed at a NCO/OH equivalent ratio.
1.1, and measured the viscosity change at 80℃ using a B-type viscometer (manufactured by Tokyo Keiki Seisakusho).
The time required to reach 500 poise was determined. The results are shown in Table-1.

[Table] Examples 4 to 6 As component (A), the hydrogenated product of the unsaturated hydrocarbon polymer having a hydroxyl group at the terminal obtained in Reference Example 1 was
The polyisocyanate compounds shown in Table 2 as component (B) were mixed so that the NCO/OH equivalent ratio was 1.1, and the mixture was heated and pressed at 150°C for 3 hours in a mold.
A cured sheet with a thickness of mm was obtained. Table 2 shows the results of measuring the mechanical properties and electrical properties of this cured product.
Shown below.

[Table] Examples 7 to 9 and Comparative Examples 4 to 6 The hydrogenated product of the unsaturated hydrocarbon polymer having a hydroxyl group at the end obtained in Reference Example 1 and the polyisocyanate compound shown in Table 3 were mixed in NCO/OH equivalents. The ratio is
After mixing the mixture to a temperature of 1.1 and leaving it in a storage room at 10°C for 2 weeks, it was heated to 90°C and examined for fluidity. The results are shown in Table-3.

[Table] Example 10 Hydrogenated product of the unsaturated hydrocarbon polymer having a hydroxyl group at the end obtained in Reference Example 1, 4,4'-dicyclohexylmethane diisocyanate, and 3,3'dimethyldiphenyl-4,4' -Mixed with an equimolar mixture of diisocyanate so that the NCO/OH equivalent ratio was 1.1, measured the viscosity change at 80°C using a B-type viscometer, and calculated the time it took to reach 500 poise60 It was hot in minutes. Further, the above-mentioned curable mixture was left in a storage at 10°C for 2 weeks, and then heated to 90°C to check its fluidity, and it melted and flowed. Further, the above curable mixture was placed in a mold and heated and pressed at 150° C. for 3 hours to prepare a 2 mm thick cured product sheet, and its mechanical properties and electrical properties were measured. The results are as follows.

【table】

Claims (1)

[Claims] 1 (A) a saturated or mostly saturated hydrocarbon polymer having at least 1.5 hydroxyl groups per molecule; and (B) 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethylbiphenylene. Ren-4,4'-diisocyanate and N,N',N''-
A curable polymer composition comprising at least one polyisocyanate compound selected from tris(6-isocyanatehexamethylene)biuret.