JPH04320414A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE:To prepare a resin compsn. which is lowly viscous and excellent in heat resistance, etc., by mixing a mixture of a bisphenol A epoxy resin with an isocyanurate compd. with a specified amt. of a polyimide resin. CONSTITUTION:The title compsn. is prepd. by mixing 50-95wt.% mixture of a bisphenol A epoxy resin with an isocyanurate compd. in a ratio of 2:1 to 1:2 with 50-5wt.% polyimide resin and, if necessary, further with a polyfunctional compd., a cure accelerator, a polymn. inhibitor, etc. The compsn. is not only heat-resistant but also lowly viscous and flexible and can be suitably used for impregnation without detriment to moldability and workability in producing insulating materials for high-voltage apparatuses, structural materials, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant resin composition suitable for use as a highly heat-resistant insulating material for high-voltage equipment.

0002

BACKGROUND OF THE INVENTION Conventionally, cured polymer composites having an epoxy resin as a matrix, so-called mold-cast products, have been widely used as insulating materials and structural materials for high-voltage equipment. In addition, as society has become more sophisticated and centralized in recent years, high-voltage equipment is required to have larger capacity, higher speed, smaller size, and higher reliability, and there is a growing tendency to use heat-resistant resin for insulators. ing.

[0003] Conventional resins having this heat resistance include:
For example, bismaleimide/triazine composite resin (heat resistance 230-260°C, service temperature 160-180°C, trade name (BT2100) manufactured by Mitsubishi Gas Chemical Co., Ltd.), and the following "Chemical 1"
The materials shown in can be mentioned.

0004

[Chemical formula 1]

[0005]

[Problems to be Solved by the Invention] However, the above-mentioned resin shown in "Chemical Formula 1" with high heat resistance has a high melting point by reducing the number of long chain parts centered on the benzene ring in its structure, so it is not heat resistant. Although it has good properties, it has the disadvantage of poor flexibility and brittleness. Further, there is a problem that the workability and moldability are poor.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a heat-resistant resin composition that has heat resistance, low viscosity, and flexibility.

[0007]

[Means for Solving the Problems] The heat-resistant resin composition according to the present invention that achieves the above object has a composition of bisphenol-based epoxy resin/isocyanurate (mixing ratio of 2/1 to 2/1).
1/2) The main components are 50 to 95% by weight of the composition and 5 to 50% by weight of polyimide resin, polyfunctional acid anhydride,
It is characterized by containing a curing accelerator and a polymerization inhibitor as necessary.

In the present invention, it is preferable to use bismaleimide, which is solid at room temperature, as the polyimide resin. In order to reduce the viscosity and give flexibility to this bismaleimide, we added a polymerizable diluent to an extent that does not reduce the heat resistance.
Epoxy resin is used. At that time, a polyfunctional acid anhydride is used to improve the heat resistance of the epoxy resin.

As the polymerizable diluent, it is preferable to use a reactive diluent having a double bond, such as isocyanurate such as triallyl isocyanurate.

The epoxy resin used as the matrix in the present invention is a strong bisphenol epoxy resin, and the acid anhydride for improving the heat resistance of this resin is, for example, trimellitic acid triglyceride. In addition, as a curing accelerator, for example, Diamino・
It is preferable to use amines such as diphenylmethane.

[0011] The mixing ratio of the bisphenol epoxy resin and isocyanurate is preferably 1/2 to 2/1, and the mixing ratio of these epoxy resin/isocyanurate compositions and polyimide resin is epoxy/isocyanurate composition. It is preferable to set it as 5 to 50 weight% of polyimide resin with respect to 50 to 95 weight%. In addition, the amount of acid anhydride added is 0 in molar ratio with bisphenol epoxy resin.
．． It is preferable to set it as 8-1.2 mol. The reason for specifying this is that if it is outside the above range, the viscosity and residual bending strength of the heat-resistant resin composition obtained will deteriorate as shown in the later examples, which is not preferable.

0012

[Embodiments] Preferred embodiments of the present invention will be described below.

Examples 1 to 6 (1) 0.02 parts by weight of hydroquinone as a polymerization inhibitor was added to bismaleimide as a polyimide resin according to the predetermined formulation shown in Table 1 below.
Dissolve at 0°C. (2) Mixture of bisphenol epoxy resin (acid anhydride blend) and triallyl isocyanurate (1.5/1.
0) is heated to 100 to 120°C, added to the hydroquinone-containing bismaleimide of (1) according to the prescribed formulation shown in Table 1 below, and then uniformly stirred and mixed. (3) When the temperature of the above mixture reached 100° C. or lower, diamino diphenyl methane was added as a curing accelerator and thoroughly stirred to obtain a heat resistant resin composition.

Examples 7 to 11 Examples 1 to 6 except that the blending ratio of epoxy resin and triallylisocyanurate was set at a polymerization ratio of 2/1 to 1/2.
operated in the same manner.

The viscosity and residual bending strength of the obtained heat-resistant resin composition were measured, and the results are shown in "Table 1" and FIGS. 1 and 2.
Shown below.

(Compounded materials) - Polyimide resin (BMI-M20; trade name, manufactured by Mitsui Toatsu Co., Ltd.) - Bisphenol epoxy resin (Epicote 828; trade name, produced by Shell Chemical Co., Ltd.) - Acid anhydride (trimellitic acid triglyceride) (trade name, manufactured by Nippon Rika Co., Ltd.) (Curing conditions) After heating at 160°C for 5 hours, heating at 200°C for 5 hours, and further heating at 280°C for 1 hour for curing. (Deterioration conditions) Deterioration was performed by heating at 280° C. for 400 hours.

[0017]

[Table 1]

[0018] If the evaluation residual rate (%) of the bending strength residual rate is large, the prescribed thermal deterioration (280°C
Even after 400 hours), the influence of deterioration is small and therefore the bending strength retention rate is high. Therefore, from the results shown in "Table 1", it was confirmed that the resin composition had good heat resistance and low viscosity.

[0019]

Effects of the Invention As explained above in conjunction with the examples, the heat-resistant resin composition according to the present invention is made by blending an epoxy resin/isocyanurate with a polyimide resin, so it has heat resistance, low viscosity, and flexibility. It becomes a composition with properties,
When used as a resin composition for impregnation, moldability and workability do not deteriorate.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between blending ratio and viscosity according to this example.

FIG. 2 is a graph showing the relationship between the blending ratio and the residual bending strength according to the present example.

Claims (1)

[Claims] Claim 1: A composition of bisphenol-based epoxy resin/isocyanurate (mixing ratio 2/1 to 1/2)
0 to 95% by weight and 5 to 50% by weight of polyimide resin
1. A heat-resistant resin composition comprising as main components a polyfunctional acid anhydride, a curing accelerator, and a polymerization inhibitor, if necessary.