Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Kazuo Goto

Masahiko Sakai

Toshikazu Narahara

Shinichi Toyoda

Keiji Suzuki

Tsutomu Kono

Mitsuru Onoda

Yasuaki Kageyama

Hiroki Nakatsuchi

Takahiro Sato

Hitoshi Yokono

Kenji Ikeda

Shunichi Numata

Hiroaki Kojima

Toru Koyama

Junji Mukai

Yoshiharu Karasawa

Hisashi Morooka

The present invention provides a method for analyzing growth of void of resin in a porous material which comprising the steps of inputting data of the shape of a porous material filled with a resin material, and dividing the shape of the porous material into three-dimensional solid elements; inputting physical properties of the porous material, and boundary conditions including a pressure that is applied to the porous material; obtaining a resin-density distribution in the porous material through fluid analysis using a database obtained by experimentally measuring in advance a temporal change in a volume of gas generated from the resin material and porous material during heating, changes in a compressive force and compressive displacement respectively occurring when the porous material impregnated with the resin is compressed, and a change in a flow resistance of the resin; and comprehensively grasping production, growth, and distribution of voids deriving from gas generation.

Method for analyzing growth of void of resin in a porous material

The present method aims at preventing breakdown by selecting conditions for preventing the occurrence of voids via analysis. According to the present method, a database related to the time variation of amount of generated gas or number of moles when a solid member is heated is experimentally formulated in advance, and the amount of generated gas from the member and the specific heat ratio of gases are entered for analysis in order to predict via analysis the generation of voids within the resin material when the solid member is heated, to thereby select conditions for preventing voids.

Method for predicting volume change of void generated in resin filled in porous body, and method for analyzing flow of resin material in porous body

Electric machine windings produced by wrapping a composite insulating material around an electrical conductor, said composite insulating material having been prepared by bonding two or more insulating materials with a silicone resin containing hydroxyl groups in the molecular structure, impregnating said composite insulating material with an insulating varnish comprising 1 equivalent of a polyfunctional epoxy compound and 2.5 to 25 equivalents of a polyfunctional isocyanate compound and curing said varnish, have excellent insulation properties under high temperatures and high humidity and thermal resistance of class H or more.

Process for producing electric windings

A thermosetting resin composition comprising a polyfunctional epoxy compound such as diglycidyl ether of bisphenol A, a polyfunctional isocyanate such as diphenylmethane diisocyanate, a curing agent and a polybutadiene type homopolymer having terminal hydroxyl groups or copolymer having terminal amino groups, or a reaction product of a polyfunctional epoxy compound or an epoxy compound having halogen atom(s) and a polybutadiene type homopolymer or copolymer having terminal hydroxyl groups or terminal carboxyl groups can produce cured articles excellent in heat resistance, crack resistance and fire resistance.

Thermosetting resin composition

A thermosetting resin composition comprising a polyfunctional epoxy compound such as diglycidyl ether of bisphenol A, a polyfunctional isocyanate such as diphenylmethane diisocyanate, a curing agent and polybutadiene type polymer having terminal hydroxyl groups can produce cured articles excellent in heat resistance and crack resistance.

Thermosetting resin compositions are obtained by mixing a resinous addition product produced by reacting an isocyanate compound having a molecular weight of 100 to 2000 and containing at least two isocyanate groups in its molecule with an epoxyphenol compound represented by the formula, ##EQU1## wherein R is a bi- or more valent group containing phenyl, R.sub.1 is hydrogen, methyl or ethyl, m and n each are an integer of 1-8, and optionally an ordinary thermosetting epoxy resin, and 0.01 to 10 % by weight of a basic heterocycle forming catalyst based on the weight of said resinous addition product, said isocyanate compound and said epoxyphenol compound being blended so that said OH group may be present in an amount of 1/3 to 1 equivalent per equivalent of said isocyanate group and said epoxy group may be present in an amount of one-fifth to two-thirds equivalent per equivalent of said isocyanate group. The said addition product can be converted into a stable B-stage and is particularly useful as a varnish for prepreg.

Thermosetting resin compositions prepared from isocyanates and

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Mito, Japan

Kazuo Goto