Ube Industries, Inc.

Ube Industires, Ltd.

Ubi Industries, Ltd.

Fumio Aoki

Hiroaki Yamaguchi

Hideki Ozawa

Akinori Shiotani

Katsutoshi Washio

Tatsuo Tsumiyama

Shuichi Hirano

Disclosed are polyimide short fibers having an extremely high heat resistance, suitable for non-woven fabrics and paper, and having many branches. Specifically, disclosed are polyimide short fibers having many branches, which are produced by beating and loosening a specific foamed polyimide material. The foamed material preferably comprises a polyimide produced using 2,3,3',4&#x2032;-biphenyltetracarboxylic acid as an aromatic tetracarboxylic acid component, preferably has a glass transition temperature of 300&#xb0; C. or higher, and preferably has an expansion ratio of 20 times or more.

Polyimide short fibers and heat-resistant paper comprising same

A thermosetting solution composition composed of a biphenyltetracarboxylic acid compound containing a partial lower aliphatic alkyl ester of 2,3,3',4&#x2032;-biphenyltetracarboxylic acid and/or a partial lower aliphatic alkyl ester of 2,2&#x2032;,3,3&#x2032;-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount larger than a molar amount of the biphenyltetracarboxylic acid compound, a partial lower aliphatic alkyl ester of 4-(2-phenylethynyl)phthalic acid compound in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and an organic solvent composed of a lower aliphatic alcohol is of value for manufacture of a prepreg.

Thermosetting solution composition and prepreg

A polyimide powder for an antistatic polyimide molded product is disclosed. The polyimide powder comprises a polyimide-powder prepared from an aromatic tetracarboxylic acid component and a diamine component, and a conductive carbon black having a DBP oil absorption of 300 ml/100 g or more; wherein the amount of the conductive carbon black is within a range of 0.75 wt % to 5 wt % relative to the polyimide-powder. A polyimide molded product with sufficient antistatic property can be formed by molding the above polyimide powder.

Polyimide powder for antistatic polyimide molded product and polyimide molded product thereby

A water-soluble polyimide precursor, which can be suitably applied for aromatic polyimides and exhibits a low reduction in heat resistance and mechanical properties, an aqueous solution of the polyimide precursor and a polyimide obtained from the precursor. A heat-resistant fiber impregnated material and an impregnated sheet-like material are prepared by using the precursor and a laminate is prepared by employing the precursor.

Water-soluble polyimide precursor, aqueous polyimide precursor solution, polyimide, impregnated material with polyimide binder, and laminate

A polyimide/metal composite sheet is composed of a metal film and a polyimide film polyimide which is prepared by reaction of asymmetric biphenyltetracarboxylic acid dianhydride and 1,3-bis(4-aminophenoxy)benzene. The polyimide film is firmly bonded to and hardly peelable from the metal film. The polyimide film can contain a solid filler.

Polyimide/metal composite sheet

A metal film, particularly, a stainless steel film having been not subjected to roughing treatment, and an aromatic polyimide substrate film having a thermoplastic surface can be combined with a high bonding strength to form a metal film/aromatic polyimide film laminate, utilizing an amorphous aromatic polyimide film of 0.05 to 3 &mgr;m thick which has a glass transition temperature in the range of 200 to 300&deg; C.

Metal film/aromatic polymide film laminate

A process for production of polyimide powder, which comprises reacting a biphenyltetracarboxylic dianhydride and an aromatic diamine in an amide-based solvent optionally containing a water-soluble ketone, in the presence of an imidazole at 1-100 equivalent percent based on the carboxylic acid content of the polyimide precursor, separating and collecting the produced polyimide precursor powder from a water-soluble ketone solvent containing 3-30 wt % of an amide-based solvent, and heating the polyimide precursor powder to an imidation rate of 90% or greater, as well as polyimide powder obtained thereby, molded bodies of the polyimide powder, and a process for production of the molded bodies.

Process for production of polyimide powder, polyimide powder, polyimide powder molded bodies and process for their production

A process for production of polyimide powder, which comprises reacting an aromatic diamine with a partial ester of a biphenyltetracarboxylic dianhydride, which is a partial ester of a biphenyltetracarboxylic dianhydride with a primary alcohol of 1-5 carbon atoms of which at least 30 mole percent is a 2,3,3&prime;,4&prime;-biphenyltetracarboxylic acid component, in the presence of the primary alcohol, separating out and collecting the resulting solid polyimide precursor and heating for dehydrating ring closure, polyimide powder obtained thereby, molded bodies of the polyimide powder, and a process for production of the molded bodies.

A polyimide composite film favorably employable for preparing a heat-resistant metal foil/polyimide film composite is composed of a polyimide substrate showing a thermal expansion coefficient of 1&times;10,to 2&times;10,cm/&deg; C. in a temperature range of 50 to 200&deg; C. and a polyimide film which is bonded to the substrate and which is made of polyimide composed of 30-100 molar % of the recurring unit (A) and 70-0 molar % of the recurring unit (B):

Polyimide composite film

Aromatic polyimide powder wherein a solid portion consisting of a highly heat resistant crystalline aromatic polyimide is covered with a coating layer of an amorphous polyimide, and a process for producing polyimide powder molded bodies by compression molding of the powder. The polyimide powder has satisfactory secondary molding workability, and molding thereof gives molded bodies which retain heat resistance and dimensional stability while having high mechanical strength and elongation.

Polyimide powder and process for producing powder molded body

An aromatic polyimide precursor composition advantageously employable for the production of an amorphous aromatic polyimide film having Tg of 300.degree. C. or higher is composed of an aromatic tetracarboxylic acid component and an aromatic diamine component which are dissolved in an organic solvent, in which at least 60 mol. % of the aromatic tetracarboxylic acid component is 2,3,3',4'-bi-phenyltetracarboxylic acid, its monoester or diester of a primary alcohol, or their mixture, and at least 55 mol. % of the aromatic diamine component is 4,4'-diaminodiphenyl ether.

Aromatic polyimide film and its precursor composition

A polyimide/metal composite sheet is composed of a polyimide substrate film (made of polyimide prepared by reaction of symmetric biphenyltetracarboxylic acid dianhydride and p-phenylenediamine, and optionally 4,4'-diaminodiphenyl ether), a polyimide intervening layer (made of polyimide prepared by reaction of asymmetric biphenyltetracarboxylic acid dianhydride and 1,3-bis(4-aminophenoxy)benzene), and a metal foil. The polyimide substrate film and the intervening polyimide layer are firmly combined and hardly peelable from each other, and the intervening polyimide layer and the metal foil are combined strongly by hot-melt.

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Ichihara, Japan

Fumio Aoki