Abstract: A polymer is disclosed, represented by Chemical Formula 1 or Chemical Formula 2: wherein, in Chemical Formula 1 and Chemical Formula 2, Ar1, Ar2, R3, s, x, and y are defined in the detailed description.

Abstract: The present invention relates to semiaromatic and semicrystalline thermoplastic polyimides obtained by polymerization of at least one aromatic compound comprising two anhydride functions and/or carboxylic acid and/or ester derivatives thereof and a diamine comprising between 13 and 22 carbon atoms. These polyimides may be converted into plastic articles by various methods, such as injection-molding.

Abstract: Pressure sensitive adhesives produced from naturally occurring fats and oils are described. Also described are methods of producing the pressure sensitive adhesives. Generally, one or more naturally occurring fats or oils are epoxidized, and then reacted with certain alcohols or amines to thereby obtain the noted pressure sensitive adhesives.

Abstract: A method of preparing an optical film, preparing a coating composition including an amic acid-containing polymer represented by Chemical Formula 1 and at least one polymerization aid selected from an alkyl phosphite, an aryl phosphite, an alkyl phosphate, and an aryl phosphate; providing the coating composition on a substrate to form a coating layer; and applying heat to the coating layer to prepare a cured film: wherein, in Chemical Formula 1, are the same or different in each repeating unit, and are each independently at least one selected from an aromatic organic group, an aliphatic organic group, and an alicyclic organic group, and 0?x?1.

Abstract: The present invention provides a polyimide film which is both outstandingly transparent and highly heat resistance, and which can be usefully employed as a transparent electrically conductive film, a TFT substrate, a flexible printed circuit substrate, and the like.

Abstract: A dianhydride monomer having a large side chain R is provided. The large side chain would interrupt the symmetry and regularity of diamine monomer. The diamine monomer has the general formula shown as formula (I) below: The functional group R includes ?-substitution cycloalkene having at least a tertiary carbon atom, cycloalkene having at least a tertiary carbon atom, cycloalkane having at least a tertiary carbon atom, ?-substitution phenyl, phenyl, ?-substitution naphthalyl, naphthalyl, ?-substitution phenanthrenyl, phenanthrenyl, ?-substitution anthracenyl, anthracenyl, ?-substitution adamantyl, adamantyl, ?-substitution adamantyl and adamantyl.

Abstract: A method for manufacturing a solution of a diacid and diamine salt for manufacturing polyamide is described. A method for manufacturing an aqueous solution of diacid and diamine salts produced by mixing at least two diacids and at least one diamine, with a weight concentration of salt between 40% and 70%, including, in a first step, preparing an aqueous solution of diacid(s) and diamine(s) with a diacid/diamine mole ratio of less than 1 using one diacid and one diamine, and in a second step, adjusting the mole ratio of diacids/diamine(s) to a value of between 0.9 and 1.1, and fixing the weight concentration of salt by adding another diacid and, optionally, additional water and/or diamine is also described.

Abstract: A non-leaching mediator may include a polymer having a polymeric backbone, and a plurality of phenothiazine groups bonded to the polymeric backbone. The plurality of phenothiazine groups may include at least one of a phenothiazine group having the general formula (IV): and salts thereof, where n is about 9 and “R” represents the polymeric backbone to which the phenothiazine group is bonded, and a phenothiazine group having the general formula (V): and salts thereof, where n is about 9 and “R” represents the polymeric backbone to which the phenothiazine group is bonded.

Abstract: A process for the production of non-thermoplastic polyimide film whose precursor solution has high storage stability and which exhibits high adhesiveness even without expensive surface treatment, more specifically, a process for the production of non-thermoplastic polyimide film made of a non-thermoplastic polyimide containing a block resulting from a thermoplastic polyimide which comprises (A) the step of forming a prepolymer having amino or an acid anhydride group at the end in an organic polar solvent (B) the step of synthesizing a polyimide precursor solution by using the obtained prepolymer, an acid anhydride, and a diamine in such a way as to become substantially equimolar over the whole step, and (C) the step of casting a film-forming dope containing the polyimide precursor solution and subjecting the resultant dope to chemical and/or thermal imidization, wherein the diamine and acid dianhydride used in the step (A) are selected so that the reaction of both with each other in equimolar amounts can give

Abstract: A cross-linked metal-containing polyamic acid includes a metal and a cross-linked polyamic acid which is a condensation product of an acid anhydride represented by Formula 1 and a diamine compound: where the group comprises a C5-C20 carbocycle having a cross-linkable functional group or a C4-C20 heterocycle having a cross-linkable functional group. A cross-linked metal-containing polyimide, a method of manufacturing the cross-linked metal-containing polyimide, a polyimide film including the cross-linked metal-containing polyimide, and a method of making the polyimide film are disclosed.

Abstract: A polyamide membrane comprising reaction product of an anhydrous solution comprising an anhydrous solvent, at least one polyfunctional secondary amine and a pre-polymer deposition catalyst; and an anhydrous, organic solvent solution comprising a polyfunctional aromatic amine-reactive reactant comprising one ring. A composite semipermeable membrane comprising the polyamide membrane on a porous support. A method of making a composite semipermeable membrane by coating a porous support with an anhydrous solution comprising an anhydrous solvent, a polyfunctional secondary amine and a pre-polymer deposition catalyst, to form an activated pre-polymer layer on the porous support and contacting the activated pre-polymer layer with an anhydrous, organic solvent solution comprising a polyfunctional amine-reactive reactant to interfacially condense the amine-reactive reactant with the polyfunctional secondary amine, thereby forming a cross-linked, interfacial polyamide layer on the porous support.

Abstract: In a method for preparing a polyimide resin by reacting diamine and dianhydride, the polyimide resin is polymerized under the presence of a solvent having a boiling point ranging from 130° C. to 180° C. so as to be curable at a low temperature ranging from 150° C. to 250° C. Because the polyimide is curable even at a low temperature, when the polyimide resin is used as an electronic material, damage to equipment due to an otherwise high temperature process can be minimized, and in addition, the polyimide resin can be extensively used as an electronic material such as for a plastic substrate, or the like.

Abstract: A method for forming a polyimide composite article utilizes a polyimide resin system including at least a first prepolymer component and a second prepolymer component. A preform structure is tackified with the first prepolymer component. Using resin infusion or resin transfer molding techniques, the tackified preform structure is contacted with the second prepolymer component. The polyimide resin system is cured under suitable cure conditions so that the first and second prepolymer components mix and react to produce the polyimide composite structure.

Abstract: The invention provides a carbon nanotube compound and method for producing the same. The method of the invention comprises the following steps. Firstly, Aniline-trimer and DMAc(dimethyl acetamide) solution are mixed to form a first solution. Secondly, Dianhydride and DMAc solution are mixed to form a second solution. The first solution and the second are mixed to form a third solution. Additionally, carboxyl-multiwall carbon nanotubes (c-MWNT), Diaminodiphenylether and DMAc solution are mixed to form a fourth solution. The third solution and the fourth are mixed to form a polyamic acid/CNT solution. Some polyamic acid/CNT solution is spread on a substrate and processed by a thermal treatment, and a carbon nanotube compound is eventually produced.

Abstract: A polyimide material comprises a polyimide. The polyimide has repeating units of formula (I). The polyimide material further comprises a coupling agent-containing filler. A method for preparing a polyimide material comprises allowing a mixture comprising an aromatic tetracarboxylic dianhydride, an aromatic diamine, and a coupling agent-containing filler to react to produce a polyamic acid. The method further comprises contacting the polyamic acid with an aliphatic dicarboxylic acid of formula (II) to produce an intermediate, and imidizing the intermediate to produce the polyimide material. A polyimide comprises repeating units of formula (I).

Abstract: Processes for feeding catalyst systems to a melt phase process for the manufacture of polyester polymers, and more particularly, to split catalyst solution feeds to the melt phase process to provide the target amount and ratio of catalyst metals.

Abstract: A method of producing high molecular weight stereoregular head, tail-poly(alkylene D-glucaramides) is described. Amidoamino acids are esterified in cold alcohol and then polymerized in a protic solvent to form steroregular prepolymers. The prepolymers are then further polymerized by dissolving them in a solvent to form larger, purer postpolymers. Compositions of matter prepared using the subject method are also described.

Abstract: 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.

Abstract: A soluble polyimide for a photosensitive polyimide precursor and a photosensitive polyimide precursor composition including the soluble polyimide, wherein the soluble polyimide contains hydroxyl and acetyl moieties and at least one reactive end-cap group at one or both ends of the polymer chain. The photosensitive polyimide precursor composition comprises the soluble polyimide, a polyamic acid containing at least one reactive end-cap group at one or both ends of the polymer chain, a photo acid generator (PAG) and optionally a dissolution inhibitor. Since the polyimide film of the present invention exhibits excellent thermal, electric and mechanical properties, it can be used as insulating films or protective films for various electronic devices. A pattern with a high resolution may be formed even on the polyamide film having a thickness of above 10 ?m.

Abstract: A method for preparation of a sulfonic and or sulfonic acid salt containing polyimide resins comprising melt reaction of a polyimide resin with an organic compound, wherein the organic compound contains at least one aliphatic primary amine functionality and at least one other functionality selected from the group consisting of sulfonic acids, sulfonic acid salts or mixtures thereof.

Abstract: A material for dielectric films is a polymerizable composition containing an adamantanepolycarboxylic acid represented by following Formula (1): wherein X is a hydrogen atom, a carboxyl group or a hydrocarbon group; and Y1, Y2, Y3 and Y4 are the same as or different from one another and are each a single bond or a bivalent aromatic cyclic group; an aromatic polyamine represented by following Formula (2): wherein Ring Z is a monocyclic or polycyclic aromatic ring; and R1 and R2 are each a substituent bound to Ring Z, are the same as or different from each other and are each an amino group, a mono-substituted amino group, a hydroxyl group or a mercapto group; and a solvent other than ketones and aldehydes, in which the adamantanepolycarboxylic acid and aromatic polyamine are dissolved in the solvent

Abstract: A preparation process of polyimide aerogels that composed of aromatic dianhydrides and aromatic diamines or a combined aromatic and aliphatic diamines is described. Also descried is a process to produce carbon aerogels derived from polyimide aerogel composed of a rigid aromatic diamine and an aromatic dianhydride. Finally, the processes to produce carbon aerogels or xerogel-aerogel hybrid, both of which impregnated with highly dispersed transition metal clusters, and metal carbide aerogels, deriving from the polyimide aerogels composed of a rigid aromatic diamine and an aromatic dianhydride, are described. The polyimide aerogels and the polyimide aerogel derivatives consist of interconnecting mesopores with average pore size at 10 to 30 nm and a mono-dispersed pore size distribution. The gel density could be as low as 0.008 g/cc and accessible surface area as high as 1300 m2/g.

Abstract: Disclosed herein are polyetherimide compositions comprising structural units of the formula: derived from at least one benzimidazole diamine, wherein R1 and R2 are independently selected from hydrogen and C1–C6 alkyl groups; “A” comprises structural units of the formulae: or mixtures of the foregoing structural units; wherein “D” is a divalent aromatic group, R3 and R10–R12 are independently selected from hydrogen, halogen, and C1–C6 alkyl groups; “q” is an integer having a value of 1 up to the number of positions available on the aromatic ring for substitution; and “W” is a linking group; and “B” comprises substituted and unsubstituted arylene groups having from about 6 to about 25 carbon atoms. Methods for producing the polyetherimide compositions are also disclosed herein.

Abstract: A novel polyimide resin consisting essentially of 3,3?,4,4?-benzophenonetetracarboxylic dianhydride (BTDA), 3,4,3?,4?-biphenyltetracarboxylic dianhydride (BPDA), 2,2 bis (3?,4?-dicarboxy phenyl) hexafluoro propane dianhydride (6FDA), 2-(3,4-dicarboxyphenyl)-1-phenylacetylene anhydride (4-PEPA) and an aromatic diamine.

Abstract: The present invention relates to novel polyimides derived from 6FDA and from 3,3-dihydroxy-4,4?-diaminobiphenyl and novel polyimides derived from PMDA and from Bis-AP-AF, having alkyl, arylalkyl, heteroarylalkyl, (cycloalkyl)alkyl, fluoroalkyl or siloxane side groups. The present invention also relates to a method of producing nematic liquid-crystal devices, which comprises the steps consisting in: depositing one of the polyimides according to the invention on a substrate; annealing the polyimide in one or more steps; and defining an azimuthal orientation of the polyimide coating.

Abstract: A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion® PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5–5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O2 and H2 gas permeability, while retaining proton conductivities similar to Nafion®. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

Abstract: This invention relates to polyimides having improved thermal-oxidative stability, to the process of preparing said polyimides, and the use of polyimide prepolymers in the preparation of prepregs and composites. The polyimides are particularly useful in the preparation of fiber-reinforced, high-temperature composites for use in various engine parts including inlets, fan ducts, exit flaps and other parts of high speed aircraft.

Abstract: Polyimide precursors contained in resin compositions of the present invention have a polymer structure unit represented by formula (1) below: wherein chemical structure A2 includes an alicyclic compound but not an aromatic compound such as a benzene ring so that they provide excellent light transmission over a wide wavelength range. The polyimide precursors are imidized at 7.5% or more and 36% or less so that they are less soluble in developing solutions and therefore are not dissolved in the developing solutions at unexposed parts. Thus, the resin compositions of the present invention can be used to form a resin film having a precise pattern by exposure and development.

Abstract: A polyimide composition and a process to prepare polyimide resins with reduced plate out and mold deposits is described. During resin molding operations the low plate out resins show a longer period of operation between cleaning of equipment leading to more efficient operation.

Abstract: A process of preparing a polyimide of the present invention comprises effecting an imidization reaction of a diamine and a tetracarboxylic dianhydride in a solvent containing 50 to 100% by weight of an equimolar composition of a nitrogen-containing cyclic compound indicated by chemical formula (1) below and a phenol indicated by chemical formula (2) below: in formula (1), X represents —CH2— or —N(CH3)—, and in formula (2), R1 and R2 may be the same as, or different from, each other and represent each any one of —H, —OH, —CH3, —C2H5, —C3H7, —C4H9, —C5H11, —C6H13, —C7H15, —C8H17, —C9H19, —C10H21, —OCH3, —O(C6H5), —NO2, —Cl, —Br and —F.

Abstract: A series of low melting and low viscosity phenylethynyl end-capped polyimides (PETIs) possessed of long term thermal and mechanical stability useful as films, melt coatings, adhesives, matrix and RTM resins and particular as coatings for optical fibers and phenylethynyl end-capped bismides blended with PETIs are disclosed. Processes for their production including: 1) modification of PETI-5 oligomer by molecular weight adjustments by blending with reactive low melting phenylethynyl end-capped imide monomers, 2) modification of the PETI-5 backbone structure with other diamine components, and 3) modification of the PETI-5 backbone with bulky fluorinated groups are also disclosed.

Abstract: The invention provides a polyimide film manufactured from a polyamic acid prepared from pyromellitic dianhydride in combination with 10 to 60 mol % of phenylenediamine and 40 to 90 mol % of 3,4?-oxydianiline, based on the overall diamine. The polyimide film, when used as a metal interconnect board substrate in flexible circuits, chip scale packages (CSP), ball grid arrays (BGA) or tape-automated bonding (TAB) tape by providing metal interconnects on the surface thereof, achieves a good balance between a high elastic modulus, a low thermal expansion coefficient, alkali etchability and film formability.

Abstract: High molecular weight random polyhydroxypolyamides (PHPAs) are produced by creating prepolymers which are further polymerized. Random prepolymers are formed from a stoichiometrically molar balance (1:1) starting material. The starting material is a 1:1 stoichiometrically balanced esterified aldaric acid:alkylene or alkylene derived diammonium salt. Alternatively, the starting material is an esterified stoichiometrically balanced diacid:diamine salt and a N?-ammoniumalkyl (or alkyl derived)-D-aldaramic acid terminal carboxylate zwitterionic salt mixture. The starting materials are polymerized in a basic alcohol using a second amine. The polymerized material, or the random prepolymers, are isolated and then further polymerized in a solvent, typically a mixed solvent of an alcohol and non-alcohol, to obtain the high molecular weight PHPAs.

Abstract: A method for the synthesis of poly(etherimide)s comprises the reaction of 4-halotetrahydrophthalic anhydride with an activating primary amine to yield an activated 4-halotetrahydrophthalimide. Activated 4-halotetrahydrophthalimide may then be aromatized and treated with the disodium salt of a bis(phenol) to yield an activated bisimide. The activated bisimide may then be directly treated with a diamine to yield poly(etherimide)s.

Abstract: A polyimide is disclosed of the formula: CG1 and CG2 are independently electron-accepting and/or electron-donating groups; x is an integer from about 3 to about 3000; ODAH is any of a number of known dianhydride residues; ODAM is any of a number of known diamine residues; and m, n, o, and p cumulatively add to 1.0, with the sum of m and n ranging from about 0.05 to about 1.0, the sum of o and p ranging from about 0 to about 0.95, the sum of m and o being about 0.5 and the sum of n and p being about 0.5. In addition, a film structure comprising the polyimide and devices utilizing the film structure are disclosed.

Abstract: In a step of polymerizing polyamic acid by mixing tetracarboxylic acid dianhydride and diamine and polycondensating the tetracarboxylic acid dianhydride and diamine under the presence of a polymerization-use solvent, a tetracarboxylic acid dianhydride slurry in which a tetracarboxylic acid dianhydride is dispersed in a dispersion medium is used. According to this, it is possible to directly manufacture a polyamic acid solution having a high concentration of polyamic acid more than or equal to 10% by weight. Especially, even if a tetracarboxylic acid dianhydride having low solubility in the polymerization-use solvent, it is possible to effectively manufacture a polyamic acid solution having high solids content, by a simple process and in a short time.

Abstract: Copolyetherimides comprise phthalimide structural units comprising both 3- and 4-linkages, wherein the designations 3-linkage and 4-linkage refer to the isomeric positions on the phthalimide ring in the totality of phthalimide-comprising structural units in the copolymer. The products have excellent properties, including high glass transition and heat distortion temperatures, high ductility and good melt flow properties, and low polydispersity.

Abstract: This invention is a highly concentrated stable solution of polyimide precursors (monomers) having a solids content ranging from about 80 to 98 percent by weight in lower aliphatic alcohols i.e. methyl and/or ethyl alcohol. The concentrated polyimide precursor solution comprises effective amounts of at least one aromatic diamine, at least one aromatic dianhydride or a lower molecular weight alkyl ester of said dianhydride, and a monofunctional endcap including monoamines, monoanhydrides and the lower alkyl esters of said monoanhydrides. These concentrated polyimide precursor solutions are particularly useful for the preparation of fibrous prepregs and composites for use in structural materials for military and civil applications.

Abstract: The present invention is directed to a process for electrostatically spinning fibers of polyamic acid and the fibers thus produced as well as the nonwoven webs that may be formed from the fibers. According to the processes of the present invention, polyamic acid solutions may be electrostatically spun to form fibers of very small diameter, such as, for instance, less than about 5 &mgr;m in average diameter. The fibers may be formed into a nonwoven web having very high specific surface area and large porosity. The polyamic acid may be converted to polyimide to form a polyimide nonwoven web. The polyimide nonwoven web may then be activated through a carbonization process to enhance the electrochemical properties of the web. The nonwoven webs of the invention may be utilized in a variety of electrochemical applications including, for example, electrical double layer capacitors.

Abstract: A method of making a solution of a polyimide from a diamine monomer and a dianhydride monomer is disclosed. A solution or slurry of one of the monomers in a solvent that boils at a temperature between about 80° C. and about 160° C. is prepared. The solution or slurry is heated to a temperature between about 80° C. and about 160° C. and the other monomer is slowly added to the solution or slurry. Polyamic acid that is formed quickly imidizes to form the polyimide.

Abstract: A film-formable polyimide copolymer, which comprises two kinds of tetracarboxylic acid dianhydride consisting of (A) pyromellitic acid dianhydride and (B) 3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride, and (C) 6-amino-2-(p-aminophenyl)benzimidazole has a heat-resistant dimensional stability without any deterioration of mechanical properties inherent in the polyimide resin when used as a film.

Abstract: The aromatic diamine compound of the present invention is represented by the following formula (1), and from the aromatic diamine compound a polyimide having a repeating unit represented by the following formula (4), which has low-temperature adherability, can be obtained. In the formulas (1) and (4), n is an integer of 3 to 7, each R is independently an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group, the same or different two hetero atoms selected from nitrogen atoms and oxygen atoms bonded to each benzene ring are at the ortho- or meta-positions to each other on at least one benzene ring, and when n is 3, the hetero atoms are at the ortho- or meta-positions to each other on all the benzene rings. In the formula (4), Y is a tetravalent organic group.

Abstract: The invention is a polyimide, random copolymer having repeating units of the formula (1): wherein R1 and R2 each represent a divalent group selected from and R1 and R2 may be the same or different; and x=0.60 to 0.80, y+z=0.40 to 0.20, and x+y+z=1.00, and a linear expansion coefficient at 100 to 200° C. is in the range of from 10 to 20 ppm/K. This is a useful polyimide that can be a polyimide circuit substrate material capable of keeping flat, neither shrinking nor expanding in its laminate.

Abstract: A process for the preparation of a reactive friable polyimide powder comprises dissolving an aromatic dianhydride and an organic diamine in a high-boiling, aprotic organic solvent to form a reaction solution; heating the reaction solution under imidization conditions to form an insoluble reactive polyimide and to effect substantially complete distillation of the water of reaction out of the reaction solution; and separating the insoluble reactive polyimide from the reaction solution to form a reactive friable polyimide powder.

Abstract: A polyimide film that exhibits improved peel strength when clad with a metal layer is prepared by reacting a polyamic acid polymer and an esterified polyamic acid oligomer. The esterified oligomer has from two to twenty repeating units and at least two crosslinkable groups selected from the group consisting of carbonyl, cyano, hydroxy, alkyne, maleimide, norbornene and sulfonyl groups. The polyamic acid is dissolved in a solvent to form a polyamic acid solution, which has a minimum gel-film forming temperature, or a minimum green film forming temperature, associated therewith. The esterified polyamic acid oligomer has an imidization temperature, which is higher than the minimum gel-film forming temperature, or the minimum green film forming temperature, of the polyamic acid solution.

Abstract: The present invention provides PMR-type polyimides that exhibit lower melt viscosities than PMR-type polyimides of the prior art. These PMR-type polyimides are created by incorporating flexible linkages, such as kinked structures and twisted or non-coplanar moietes into the backbone structure of the PMR. Specifically, the present invention provides for the production of PMR-type polyimides having 2,2′-disubstituted biaryls in the polymer backbone.

Abstract: This invention provides processes of the preparation of polyamides, polyimides, and polyamideimides, which are easy to purify after reactions, from polycarboxylic acids and polyamines in high yield without side reactions such as a change of color to black by direct polycondensation reaction with heat, especially processes of preparing aromatic polyamides (aramids), aromatic polyimides, and aromatic polyamideimides, which are difficult to synthesize in direct polycondensation reaction. Polyamides, polymides, and polyamideimides are prepared in high yield by the polycondensation of aromatic dicarboxylic acids, aromatic tetracarboxylic acids or aromatic tricarboxylic acids and aromatic diamines, using arylboric acids such as 3,4,5-trifluorophenylboric acids as polycondensation catalysts, in a mixed solvent of pentamethylbenzene and N-methylpyrrolidinone or a mixed solvent of m-terphenyl and N-butylpyrrolidinone.

Abstract: A polyimide film is manufactured from a random copolymeric, block copolymeric or interpenetrating polymer network-type polyamic acid prepared from pyromellitic dianhydride in combination with 22 to 78 mol % of 4,4′-oxydianiline and 22 to 78 mol % of 3,4′-oxydianiline, based on the overall diamine. The polyimide film, when used as a metal interconnect board substrate in flexible circuits, chip scale packages (CSP), ball grid arrays (BGA) or tape-automated bonding (TAB) tape by providing metal interconnects on the surface thereof, achieves a good balance between a high elastic modulus, a low thermal expansion coefficient, alkali etchability and film formability.

Abstract: The invention provides a poly(imide-benzoxazole) (PIBO) copolymer prepared from a trimellitic anhydride halide monomer and a bis(o-diaminophenol) monomer. The PIBO copolymer is characterized by the following recurring unit: wherein X is —O—, —S—, —C(CF3)2—, —C(CH3)2—, —CO—, —CH2—, —SO2—, —SO—, or deleted; and n is an integer. The PIBO copolymers of this invention are particularly useful as dielectric layers in semiconductor devices because they possess hydroxyl groups which create better adhesion to semiconductor substrates.

Abstract: 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.