Polyimides from 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines

A polyimide precursor including at least one repeating unit represented by the following chemical formula (1): in which A is an arylene group; and X 1 and X 2 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms, and a polyimide obtained from the polyimide precursor has a coefficient of linear thermal expansion from 50° C. to 400° C. of 100 ppm/K or less.

Polyimide precursor and polyimide

PROBLEM TO BE SOLVED: To obtain a display device which has an excellent display grade, substantially prevents the occurrence of problems, such as crosstalks, and has excellent reliability by using a substrate having spacers which are recessed in the sectional shapes of the uppermost layer and are fixed in non-display regions SOLUTION: The substrate for the liquid crystal display device having the spacers 16 to 18 which are recessed in the sectional shapes of the uppermost layer in the non-display regions and are fixed is used The spacers 16 to 18 come into contact with a counter substrate when the liquid crystal display device is manufactured As a result, the specified gas is held with the counter substrate and liquid crystals are injected into this gap The height (the height up to the vertex of the recessed shapes when the flat parts near the center of the spacers is determined as a reference) of the recessed shapes is 005 to 2μm If the height is too low, the effect for preventing the display defect, etc, by the nonuniformity of the cell gap is not exhibited If, conversely, the height is too large, there is a possibility that chipping is induced in the spacers by the load at the time of a rubbing treatment or at the time of assembling the panel

Substrate for liquid crystal display device and liquid crystal display device

Disclosed is a thermoplastic polyimide which has excellent heat resistance and can adhere to a metal foil by thermocompression bonding for a short-time. The thermoplastic polyimide comprising a tetracarboxylic dianhydride residue and a diamine residue wherein the biphenyl tetracarboxylic dianhydride residues account for 80 mol% or more of the total tetracarboxylic dianhydride residues, the 4,4'-diaminodiphenyl ether residues for 65 mol% or more and 85 mol% or less of the total diamine residues, and the paraphenylene diamine residues for 15 mol% or more and 35 mol% or less of the total diamine residues.

Thermoplastic polyimide, and laminated polyimide film and metal foil-laminated polyimide film using the thermoplastic polyimide

The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension The insulator comprises a laminate of one or more insulation unit layers etchable by a wet process, the insulator having been subjected to plasma treatment after wet etching The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer

Wet etched insulator and electronic circuit component

PROBLEM TO BE SOLVED: To obtain a polyimide having a high light transmission without detriment to its heat resistance by subjecting 2,3,3',4'-biphenyltetracarboxylic dianhydride and a diamine to polymn. and imidization. SOLUTION: A diamine component mainly comprising a diamine of formula I (wherein R is a 4-16C linear or branched aliph. hydrocarbon group)(e.g. 1,1- diaminohexane) and contg. an arom. diamine, etc., is dissolved in an org. solvent (e.g. N-methyl-2-pyrrolidone), and the resultant soln. is mixed with an acid dianhydride component mainly comprising a carboxylic dianhydride of formula II (e.g. 2,3,3',4'-biphenyltetracarboxylic dianhydride) and contg. other tetracarboxylic dianhydrides. The resultant mixture is subjected to polynm. and imidization under heating and then put into a poor solvent to precipitate the resultant polymer, thus giving a polyimide of formula III (wherein R is the same as in formula I) which has a logarithmic viscosity (30 deg.C) of 0.3-2 and gives a 20 μm-thick film having a Y1 of 5 or lower and a light transmission of 60% or higher at 400 nm and 85% or higher at 500 nm.

Colorless transparent polyimide and production thereof

PROBLEM TO BE SOLVED: To obtain a metal foil laminate by strongly bonding metal foil to a highly rigid base polyimide film being a multilayered polyimide film produced under a relaxed condition. SOLUTION: A soln. of polyimide or polyamic obtained by sealing the diamine terminals of 2,3,3',4'-biphenylcarboxylic dianhydride and 1,2-bis(4-aminophenoxy) benzenediamine by excessive tetracarboxylic dianhydrate or dicarboxylic anhydride is laminated to the single surface or both surfaces of a base polyimide film composed of biphenyltetracarboxylic dianhydride/paraphenylenediamine type polyimide and imidated and dried to obtain a multilayered polyimide film. This film and metal foil is bonded by a hot-melt method to obtain a metal foil laminate.

Laminate and production thereof

PURPOSE: To prepare a compsn. which can be imidated at a low temp. to form a protective film on an electronic component by adding a small amt. of lactam to an org. polar solvent soln. of a polyamic acid comprising particular two amic acid units. CONSTITUTION: An org. polar solvent soln. of a polyamic acid comprising amic acid units represented by formulae I and II [R represents a 4-12 C straight chain aliph. (oxa)hydrocarbon] (I:II unit molar ratio = (97:3) to (70:3) is prepd., and a lactam is added in an amt. of 0.005 to 10wt.% based on the polyamic acid. Pref., biphenyltetracarboxylic acid dihydride is reacted with bis(aminophenoxyphenyl)sulfone and a diamine of a 4-12 C linear (oxa)hydrocarbon in an org. polar solvent to prepare a polyamic acid, and a lactam is added thereto. The org. polar solvent is pref. N,N-dimethylacetamide or N-methyl-2- pyrrolidone. The lactam added is particularly pref. e-caprolactam. The compsn. is imidated at 220 deg.C or below to form a strong film.

Polyamic acid composition

PURPOSE:To obtain an aromatic copolyester imide having excellent melt molding properties as well as heat resistance and excellent mechanical properties by polymerizing the specific six kinds of repeating units at specific ratios. CONSTITUTION:This copolyester imide is obtained by polymerizing (A) the unit of formula I derived from p-hydroxybenzoic acid, etc., (B) the unit of formula II derived from 3,3'-dimethylbiphenyl-4,4'-dicarboxylic acid, etc., (C) the unit of formula III derived from 3,4'-dimethylbiphenyl-4,3'-dicarboxylic acid, etc., (D) the unit of formula IV derived from terephthalic acid, etc., (E) the unit of formula V (Ar is bivalent aromatic group) derived from 4,4'- dihydroxybiphenyl, etc., (F) the unit of formula VI (R is of formula VII or VIII) derived from diimides. The molar ratios of the units A to F satisfy the following equations. 0< component A/(components A+B+C+D+E+F) molar ratio <=85/100, 5/100<= component D/(components B+C+D) molar ratio <1. 0< component F/(components E+F) molar ratio <40/100, components B+C+D = components E+F.

Aromatic copolyester imide

PROBLEM TO BE SOLVED: To obtain a polyimide powder molding excellent in heat resistance, dimensional stability, mechanical strengths and elongation by packing a specified aromatic polyimide powder into a mold and molding the powder. SOLUTION: An aromatic polyimide powder which is prepared by coating a solid mainly consisting of a crystalline aromatic polyimide having such high heat resistance that no glass transition temperature is observed in the range of room temperature to 400 deg.C with a coating film of an amorphous polyimide and is judged to have a high molecular weight from the measurement of a logarithmic viscosity (at 30 deg.C in a concentration of 0.5g/100ml concentrated sulfuric acid) and whose crystallinity can be confirmed by wide-angle X-ray diffractometry is packed into a mold and molded under applied pressure and heat. This polyimide powder is prepared from an acid component comprising 3,3',4,4'-biphenyltetracarboxylic acid dianhydride and 0.5 to below 30mol% 2,3,3',4'-biphenyltetracarboxylic acid dianhydride and an aromatic diamine component comprising at least 80mol% p-phenylenediamine and has a mean particle diameter of 0.5-100μm.

Shiotani Akinori

Papers

Colorless transparent polyimide and production thereof

Laminate and production thereof

Polyamic acid composition

Aromatic copolyester imide

Polyimide powder and preparation of powder molding