Abstract: A solvent-soluble siloxane polyimide comprising a copolymer obtained by reaction of a diamine compound mixture comprising a diaminopolysiloxane and an alicyclic diamine with an aromatic tetracarboxylic acid anhydride, followed by polyimidization reaction of the resulting polyamic acid forms a heat-resistant adhesive by adding an epoxy resin, a diamine-based curing agent and an organic solvent thereto, The formed adhesives show a distinguished heat-resistant adhesiveness when the resulting siloxane polyimide soluble in ordinary organic solvents is used as a main component of the adhesive for bonding between a base material and a copper foil of a flexible printed substrate. By further addition of a fluorinated resin to the heat-resistant adhesive, the adhesiveness can be more improved.

Abstract: This invention provides a polyimide precursor solution having high concentration and low viscosity and a production process thereof, and polyimide coatings and films having excellent physical properties obtained therefrom and a production process thereof. Particularly, it relates to a polyimide precursor solution which contains a salt of a specific diamine with a specific tetracarboxylic acid, as its solute; to a process for the production of the polyimide precursor solution, which comprises allowing 1 mole of a specified diamine to react with 0.3 to 0.9 mole of a specific tetracarboxylic acid dianhydride, thereby obtaining a diamine, and subsequently adding 0.95 to 1.

Abstract: A new diamine, 2,2'-dimethyl-4,4'-bis(4-aminophenoxy)-biphenyl was synthesized and used to prepare high performance engineering plastics by polycondensation. The new diamine as shown in the following formula has a noncoplanar 2,2'-disubstituted biphenylene and a flexible aryl units: ##STR1## The engineering plastics disclosed in the present invention includes polyamides, polyimides and poly(amide-imide)s.

Abstract: An aryletherketone polymer having repeating units of the formula: ##STR1## wherein Ar is selected from the group consisting of ##STR2## wherein Q is --O--, --CH.sub.2 -- or --CO--, is useful in the dispersion of active NLO chromophores containing a basic functionality to form optically clear films.

Abstract: A process for making polyimide-polyamic ester copolymer composition comprisingreacting at least one diamine, a pyromellitic diacid diester compound; at least one other tetracarboxylic diacid diester compound and a selected phosphoramide in the presence of a base catalyst to form a polyimide-polyamic acid ester copolymer.

Abstract: Polyetherimide polymers prepared from monomers containing indane moieties are disclosed. The high molecular weight indane polyetherimides are transparent, ductile, and exhibit high glass transition temperatures (>200.degree. C.). In addition, the polyetherimides are thermally stable at high temperatures and exhibit good optical properties making them useful in high temperature processing applications, in the fabrication of optoelectronics devices, and in optical applications.

Abstract: Aromatic polyether polymers, illustrated by polyethersulfones, polyetherketones and polyetherimides, are prepared by a phase transfer catalyzed reaction between a salt of at least one dihydroxyaromatic compound and at least one substituted aromatic compound such as bis(4-chlorophenyl) sulfone, bis(4-chlorophenyl) ketone or 1,3-bis?N-(4-chlorophthalimido)!benzene, in a monoalkoxybenzene such as anisole as diluent and in the presence of a phase transfer catalyst, preferably a hexaalkylguanidinium salt.

Abstract: A soluble rigid-rod macromonomer is provided which has the following formula: ##STR1## wherein each A.sub.1, A.sub.2, A.sub.3, and A.sub.4, on each monomer unit, independently, is C or N, and each G.sub.1, G.sub.2, G.sub.3, and G.sub.4, on each monomer unit, independently, is H or a solubilizing side group, provided that at least one monomer unit has at least one solubilizing side group. The solubilizing side groups provide the macromonomers with a solubility of at least 0.5% by weight in the solvent system from which they are formed. E is a reactive end group, and the macromonomer has an average degree of polymerization, DP.sub.n, greater than 6. Such macromonomers are chemically incorporated into polymer systems to provide stronger stiffened polymers.

Abstract: A polyamideamic acid resin prepolymer represented by formula A having isophorone diamine as one of monomers, ##STR1## in which k, l, m and n are integer of 1 or more, respectively, and ##EQU1## --R-- is at least one group selected from the group consisting of ##STR2## --R'-- is a cis- and trans-conformational mixture of ##STR3## high heat resistant polyamideimide foam produced therefrom, and processes for producing them are disclosed.

Abstract: A soluble rigid-rod macromonomer is provided which has the following formula: ##STR1## wherein each G.sub.1, G.sub.2, G.sub.3, and G.sub.4, on each monomer unit, independently, is H or a solubilizing side group, provided that at least one monomer unit has at least one solubilizing side group. The solubilizing side groups provide the macromonomers with a solubility of at least 0.5% by weight in the solvent system from which they are formed. E is a reactive end group, and the macromonomer has an average degree of polymerization, DP.sub.n, greater than 6. Such macromonomers are chemically incorporated into polymer systems to provide stronger stiffened polymers.

Abstract: 18.4 grams of 4,4'-(hexafluoroisopropyridine)diphthalic acid dianhydride and 7.5 grams of 1,4-phenylenediamine dihydrochloride are mixed in a solvent consisting of 80 ml of N-methyl-2-pyrrolidone and 20 ml of dichlorobenzene and are heated at an argon atmosphere to raise its temperature from a room temperature to 170.degree. C. slowly and to be reacted for five hours while an azeotropic dihydration of water which is generated at 170.degree. C. is conducted. After the reaction is completed, a reaction product is precipitated in methanol, the precipitate is washed with methanol and dried at 80.degree. C. FIG. 1 shows the infrared spectra of the reaction product.

Abstract: A method is provided for the preparation of polyquinoline polymers based on Friedlander condensation polymerization. The method comprises mixing monomers which, when polymerized, form a polyquinoline polymer, together with a catalyst and a solvent, wherein the catalyst comprises an alkyl phosphate.

Abstract: This invention is directed to a polyimide film useful as use applications for electronic materials; a liquid crystal aligning film using the same; a liquid crystal display element provided with the liquid crystal aligning film; and a polyamic acid used as a raw material of the polyimide constituting the polyimide film.The polyimide used for preparing the above polyimide films, consists of a diamine component, the 50% by mol or more based upon the total diamine, of which is a diamine having a core structure having no polar group such as 1,2-bis(4-(4-aminobenzyl)phenyl)ethane, 1,6-bis(4-(4-aminobenzyl)phenyl)hexane, 1,1-bis(4-(4-aminobenzyl)phenyl)heptane, etc., and a tetracarboxylic acid dianhydride, and if necessary, an aminosilicon compound, is used as a liquid crystal aligning film.

Abstract: Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.

Abstract: A process for the preparation of aromatic polyamide pulp having both excellent physical properties and a high degree of polymerization by continuous polymerization and orientation by using of mixed solutions. The solutions are prepared by reacting diamine with aromatic diacid dichloride in an amide and/or urea-based polymerization solvent containing inorganic salts, or a mixture of inorganic salts and a Lewis acid compound. The process can be practiced by polymerization-orientation apparatus located on the continuous transferable polymerization-orientation means comprised of a belt and one or more stirring bars.

Abstract: Provided are photosensitive resin compositions comprising a polyamic compound having, at each terminal thereof, a specific actinic ray-sensitive functional group which has substituent groups each having a photopolymerizable carbon-carbon double bond, a photosensitive auxiliary having a photopolymerizable functional group and a solvent. The photosensitive resin compositions of the invention are excellent in resist properties such as sensitivity and good in storage stability and can provide a film small in residual stress.

Abstract: The present invention relates to a process of producing a polyimide-type copolymer, to a thin layer forming agent, to a liquid crystal alignment layer and to processes of producing thin layer formation agents and liquid crystal alignment layers. More specifically, this invention relates to a polyamic acid block copolymer, a polyimide block copolymer, a polyimide-polyamic acid block copolymer, a thin layer forming agent comprised of a polyimide-type block copolymer, and a liquid crystal alignment layer comprised of a polyimide-type block copolymer and processes of their production.

Abstract: In the process of the present invention, a non-polar, aprotic solvent is removed from an oligomer/polymer solution by freeze-drying in order to produce IPNs and semi-IPNs. By thermally quenching the solution to a solid in a short length of time, the size of the minor constituent-rich regions is greatly reduced as they are excluded along with the major constituent from the regions of crystallizing solvent. The use of this process sequence of controlling phase morphology provides IPNs and semi-IPNs with improved fracture toughness, microcracking resistance, and other physical-mechanical properties as compared to IPNs and semi-IPNs formed when the solvent is evaporated rather than sublimed.

Abstract: A liquid crystal aligning agent comprising a polyamic acid containing an aliphatic and/or alicyclic hydrocarbon group and a polyimide containing an aliphatic and/or alicyclic hydrocarbon group; and a liquid crystal display device using the liquid crystal aligning agent. This liquid crystal aligning agent gives a liquid crystal aligning film which has good liquid crystal aligning property and in which pretilt angle can be changed by radiation with a small energy and which is suitable for domain-divided alignment type liquid crystal display having a wide view angle.

Abstract: Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units, with an acetyl halide and dimethoxymethane in the presence of a halogen-containing Lewis acid catalyst and methanol, thereby forming a haloalkylated polymer. In a specific embodiment, the haloalkylated polymer is then reacted further to replace at least some of the haloalkyl groups with photosensitivity-imparting groups. Also disclosed is a process for preparing a thermal ink jet printhead with the aforementioned polymer.

Abstract: An angularity enhancement layer in a liquid crystal display, which display comprises a liquid crystal cell, wherein the angularity enhancement layer includes a negative birefringent polyimide layer comprising a plurality of structural units having pendant fluorene groups, said angularity enhancement layer being disposed on at least one surface of said liquid crystal cell. A liquid crystal display can comprise an angularity enhancement construction of the invention which comprises a polyimide layer.

Abstract: An aromatic polyimide having a recurring unit of the formula (I): ##STR1## wherein Ar is a divalent aromatic group having one or two benzene rings which has a sulfonate group of --SO.sub.3 H, --SO.sub.3 M, and --SO.sub.3 N(L).sub.4 on the ring, wherein M is an alkali metal and L is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, is favorably employed in the form of a semipermeable film for gas separation.

Abstract: Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

Abstract: In order to produce a polymer electrolyte membrane from sulfonated, aromatic polyether ketone, an aromatic polyether ketone of the formula (I) ##STR1## in which Ar is a phenylene ring having p- and/or m-bonds,Ar' is a phenylene, naphthylene, biphenylene, anthrylene or another divalent aromatic unit,X, N and M, independently of one another are 0 or 1,Y is 0, 1, 2 or 3,P is 1, 2, 3 or 4,is sulfonated and the sulfonic acid is isolated. At least 5% of the sulfonic groups in the sulfonic acid are converted into sulfonyl chloride groups, and these are reacted with an amine containing at least one crosslinkable substituent or a further functional group, and unreacted sulfonyl chloride groups are subsequently hydrolyzed. The resultant aromatic sulfonamide is isolated and dissolved in an organic solvent, the solution is converted into a film, and the crosslinkable substituents in the film are then crosslinked.In specific cases, the crosslinkable substituents can be omitted.

Abstract: The present invention provides a film adhesive comprising, as the main constituent, a polyimide resin having a glass transition temperature of 350.degree. C. or lower and soluble in organic solvents, which polyimide resin is obtained by reacting at least one of the following acid components (A) and (B)(A) 4,4'-oxydiphthalic acid dianhydride(B) 3,3',4,4'-biphenyltetracarboxylic acid dianhydride and/or 3,3',4,4'-benzophenonetetracarboxylic acid dianhydridewith at least one of the following amine components (C) and (D)(C) a siloxane compound represented by the following general formula (1) and/or 2,2-bis(4-(4-amino-phenoxy)phenyl)propane ##STR1## wherein R.sub.1 and R.sub.2 are each a bivalent aliphatic (C.sub.1-4) or aromatic group; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each a mono-valent aliphatic or aromatic group; and k is an integer of 1-20,(D) bis(aminophenoxy)benzene and/or dimethylphenylene-diamineto give rise to ring closure of imide, as well as a process for producing said film adhesive.

Abstract: A process for intramolecularly condensing a polyamic acid composition containing an NLO compound to form a polyimide host matrix composition containing as a guest the NLO compound, which process includes the step of uniformly heating the polyamic acid composition, in the absence of a solvent or diluent, to a temperature at which the intramolecular condensation will occur without thermal degradation of the NLO compound, so that the temperature differential within the polyamic acid is below that which will produce localized thermal degradation temperatures, until the intramolecular condensation of the polyamic acid composition to the polyimide host matrix composition is substantially complete. Polyimide host matrix compositions containing guest NLO compounds prepared by the inventive process are also disclosed, wherein the NLO compounds have external field-induced molecular alignments.

Abstract: The polyimide film of this invention is formed from a polyimide, which is prepared by reacting a diamino compound represented by the general formula (1): ##STR1## wherein X represents a hydrocarbon group having 1 to 20 carbon atoms or a sulfur atom; R represents each independently a halogen atom, a hydrocarbon group having 1 to 6 carbon atoms or a halogen-containing hydrocarbon group having 1 to 6 carbon atoms; a represents each independently an integer of 0 to 4;with a tetracarboxylic dianhydride represented by the general formula (2) ##STR2## wherein Y represents a tetravalent organic group having 2 or more carbon atoms.The polyimide film obtained can be applied favorably to a flexible printed circuit board without adhesion layer, a protective coating for electronic parts and electric wires, or a heat resistant adhesive.

Abstract: A polyimide alignment film based on pyromellitic dianhydride and a bis(4-aminophenoxy) aromatic compound, such as 1,3-bis(4-aminophenoxy)benzene or 1,4-bis(4-aminophenoxy)benzene, providing low tilt angles of from to 2 degrees when used in liquid crystal displays.

Abstract: Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.

Abstract: A process for inducing pre-tilt in alignment of a liquid crystal medium comprising exposing at least one optical alignment layer, comprising anisotropically absorbing molecules and hydrophobic moieties, to polarized light; the polarized light having a wavelength within the absorption band of said anisotropically absorbing molecules; wherein the exposed anisotropically absorbing molecules induce alignment of the liquid crystal medium at an angle + and -.theta. with respect to the direction of the polarization of the incident light beam and along the surface of the optical alignment layer, and induce a pre-tilt at an angle .PHI. with respect to the surface of the optical alignment layer and applying a liquid crystal medium to said optical alignment layer, is described. The invention also is directed to liquid crystal display elements made by the process of the invention and to novel polyimide compositions that are useful as optical alignment layers in the invention.

Abstract: An aryl ester compound composed of a polyhydric phenol in which at least one OH group has been esterified with an organic acid or its derivatives having 1 to 20 carbon atoms, said polyhydric phenol being the condensation product of a phenolic compound represented by the general formula: ##STR1## with a carbonyl compound represented by the general formula: ##STR2## which aryl ester compound can give, when used as a curing agent for an epoxy resin, a cured product having a low dielectric constant and a low dielectric loss tangent; an epoxy resin composition comprising as the essential components an epoxy resin, said aryl ester compound and a cure accelerator; and a copper-clad laminate using the epoxy resin composition. The copper-clad laminate has a low dielectric constant and a low dielectric loss tangent and is excellent in adhesiveness as compared with conventional ones, and hence, is suitable for multilayer printed wiring board for high speed operation, especially at high-frequency region.

Abstract: A novel polyimide is soluble in organic solvents and excels in heat resistance. The polyimide comprises 95-40 mol % of the repeating unit represented by the formulas (1) and 60-5 mol % of the repeating unit represented by the formula (2) and has a number average molecular weight of 4,000-200,000: ##STR1## wherein X is --SO.sub.2 -- and/or --C(.dbd.O)--OCH.sub.2 CH.sub.2 O--C(.dbd.O)--, Ar is a divalent group containing aromatic rings, and R is an alkylene group having 1-10 carbon atoms or a group: --CH.sub.2 OC.sub.6 H.sub.4 --, and n is an integer of 1-20.

Abstract: The present invention provides a polyimide resin composition comprising:(a) a polyamide resin comprising a repeating unit represented by the general formula (1): ##STR1## wherein X represents a tetravalent organic group represented by the formula (2): ##STR2## Y represents a divalent organic group comprising a divalent siloxane residual group represented by the formula (3): ##STR3## wherein m is an integer of 60 to 120; and a divalent aromatic group represented by the formula (4): ##STR4## wherein R.sup.1 represents a hydrogen atom or a fluorine atom; and (B) cyclohexanone. From this composition, polyimide resin films can be obtained by heating at a lower temperature for a short time, and the films obtained show good adhesion under moisture-resistant conditions.

Abstract: Thermomechanical and thermo-oxidative stabilities in resin composites across the range of aerospace "engineering thermoplastic" resins are improved by forming four crosslinks at each addition polymerization site in the backbone of the resin using crosslinking functionalities of the general formula: ##STR1## in the oligomers, wherein Z= ##STR2## .beta.=the residue an organic radical selected from the group consisting of: ##STR3## --O--.O slashed.--COOH, --O--.O slashed.--COX, --X, --O.paren open-st.(R.sub.8 .paren close-st.OH, ##STR4## --O--.O slashed.--NH.sub.2 ; E= ##STR5## R.sub.8 =a divalent organic radical; X=halogen;Me=methylT=allyl or methallyl.G=--CH.sub.2 --, --S--, --CO--, --SO--, --O--, --CHR.sub.3 --, or --C(R.sub.3).sub.2 --;i=1 or 2;R.sub.3 =hydrogen, lower alkyl, lower alkoxy, aryl, or aryloxy; and.THETA.=--C.tbd.N; --O--C.tbd.N, --S--C.tbd.N, or --CR.sub.3 .dbd.C(R.sub.3).sub.2.

Abstract: The invention relates to a PMR type resin which comprises a mixture of:(a) nadic acid of Formula (Ia) or a derivative thereof ##STR1## (b) a diaminobisimide of Formula (Ib) ##STR2## (c) an aromatic tetracarboxylic acid of Formula (Ic) or a derivative thereof ##STR3## the components (a), (b) and (c) being present in the approximate molar proportions of 2:n:n-1 respectively.

Abstract: Novel thermoset polyimide and composite materials comprising the thermoset polyimides and a fibrous reinforcement are prepared according to this invention. The thermoset polyimides are obtained by heat-treating a linear polyamic acid or a linear polyimide prepared by using 4,4'-bis(3-aminophenoxy)biphenyl and pyromellitic dianhydride as essential monomers or by adding 4,4'-diaminodiphenyl ether or 3,3',4,4'-biphenyltetracarboxylic dianhydride to the essential monomers and by end-capping the molecular chain end with an aromatic dicarboxylic anhydride having a carbon-carbon triple bond. The thermoset polyimides have essential excellent properties of thermoplastic polyimide and additionally has enhanced heat resistance and improved mechanical properties. The thermoset polyimide can be used to provide various kinds of composite materials for aircraft matrices, electric and electronic appliances and others.

Abstract: Stable, electroactive material which when a potential is applied from the outside is subjected to one or more reversible redox reactions, for use in devices with an electrochromic display or another electrochromic color change or in batteries.The material comprises a condensed ring structure, the oxidized form of which is of the formula ##STR1## in which R.sub.1, R.sub.2, X, and A may have any meaning with the proviso that the condensed ring structure maintains the reversible properties.The material can be prepared by various processes and it is suited for use as electrochromic material for use in devices with an electrochromic display or as coating on windows because it presents a distinct and easily visible color change when it is subjected to a potential. In addition, the material is suited for use in rechargeable batteries because is possesses an excellent capacity and reversibility.

Abstract: Ketone-aldehyde resins with wide compatibility, process for their preparation, and their use. The invention relates to ketone-aldehyde resins with wide compatibility comprising cycloaliphatic ketones and, in particular, formaldehyde and, if desired, further monomers, to a process for their preparation and to their use as hard resin in paints, printing inks and other coatings, especially in pigment preparations.

Abstract: The invention is concerned with compositions comprising novel water-dispersible copolymers which contain at least one UVA light-absorbing monomer, one UVB light-absorbing monomer, one hydrophilic monomer, and optionally one hydrophobic monomer component. The UVA light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 320-400 nm range. The UVB light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 290-320 nm range. Because of the R.sub.3 group used in the invention, the copolymers used in the compositions of the invention permit higher loading of UV monomers than previously obtainable.

Abstract: Novel polyimides which are soluble in various organic solvents and excellent in thermal resistance, processability are disclosed. The polyimides comprise repeating units represented by the following formula (1) and/or (2) and having a number average molecular weight of 4,000-200,000. ##STR1## wherein Ar is a divalent group represented by the following formula (2) or (3): ##STR2## wherein Y is --O--, --CO--, --S--, --SO.sub.2 -- or --C(CH.sub.3).sub.2 --, ##STR3## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group, Ra is a divalent group having 2-6 benzene rings, X.sup.1 represents NH, NR (wherein R is a C.sub.1-4 alkyl group or a C.sub.1-4 alkoxy group) or S, Rb is C.sub.2-20 alkylene group, ether group or dimethylsiloxane group, and X.sub.2 represents NH, NR (wherein R is a C.sub.1-4 alkyl group or a C.sub.

Abstract: The present method provides a method for preparing the PI varnish which has the steps of: 1) preparing a mixed solution of 60-100% by weight aprotic solvent, and 0-40% by weight aromatic solvent; 2) adding into the mixed solution in a mole ratio of 1:9 two aromatic diamines; and 3) further adding in the mixed solution in a mole ratio of 1:5 two aromatic dianhydrides. Such PI has a suitable thermal expansion coefficient and characteristics different form those of the PI currently in use.

Abstract: An aromatic polyethersulphone incorporating sub-unit (1) where A is an electron withdrawing group, the designation "o,p" represents that the bond is at the ortho or para position to the A group, and X is selected from: OH; --O M where M is an organic or inorganic cation (other than hydrogen) and n is at least 1; --NR1R2 where R1 and R2 are the same or different and are selected from hydrogen and alkyl, aryl, aminoalkylene or ammonoalkylene groups; and --OR3 where R3 is an alkyl or aryl group; either as the only sub-units of the polymer or in combination with comonomer units.

Abstract: The invention relates to a liquid crystal orientation film having a specific polymer, the main chain of the polymer formed of urea bonds and imide bonds, and a liquid crystal display element incorporating the film. The liquid crystal orientation film does not require high temperature heat treatment when prepared, allowing treatment below about 150.degree. C. Hence, the production of a liquid crystal display element using the liquid crystal orientation film is simplified. Furthermore, other element materials are protected, and the substrate used can be a plastic substrate lower in heat resistance than glass. Moreover, the liquid crystal orientation film is excellent in such properties as liquid crystal orienting capability, heat resistance, transparency, strength and adhesion to the substrate, and has an especially large and stable pre-tilt angle.

Abstract: A poly(imide amic ester) having repeating unit of formula (I) and a process for the preparation thereof are provided, wherein formula (I) has the structure ##STR1## wherein Ar is, ##STR2## Ar' is, ##STR3## Ar" is ##STR4## R is selected from the group consisting of CH.sub.3, CH.sub.2 CH.sub.3, CH(CH.sub.3).sub.2, CH.sub.2 CH.sub.2 CH.sub.3, CH.sub.2 (CH(CH.sub.3).sub.2 and C(CH.sub.3).sub.3. Further, processes for the preparation of polyimide, polyimide film and polyimide fiber using the above poly(imide amic ester) are provided.

Abstract: A polyimide alignment film based on pyromellitic dianhydride and a 2,2'-bis(perfluoroalkoxy)benzidine, as major components, for use in liquid crystal display devices.

Abstract: The invention provides novel thermoplastic polyimide featuring solid adhesive property under low temperature, low hygroscopic coefficient, and solid resistivity to radioactive rays. The invention also provides novel polyamide acid which is substantially precursor of the thermoplastic polyimide, and also provides novel thermally fusible laminated film for covering conductive wires, featuring solid adhesive property under low temperature, solid resistivity to radioactive rays, and distinct suitability for covering superconductive wires in particular.The novel thermoplastic polyimide is represented by general formula (1) corresponding to the chemical structure shown below; ##STR1## wherein, Ar.sub.1, Ar.sub.2, Ar.sub.4, and Ar.sub.6, respectively designate divalent organic radical, whereas Ar.sub.3 and Ar.sub.

Abstract: Disclosed are polymers and copolymers containing at least one repeating unit of the formula ##STR1## in which X is O or NH; R is a single bond or a hydrocarbon chain; R' is a hydrocarbon chain containing one or two carbon atoms, and P is the residue of an oligomer HX--P--XH whose solution viscosity determined in meta-cresol at 30.degree. C. at concentrations of 0.5 g/dl is lower than 0.50 dl/g.sup.-1. Also disclosed is a process for obtaining the polymers and copolymers.

Abstract: A diaminobenzene derivative of the formula (I): ##STR1## wherein each of P and Q which may be the same or different from each other, is a single bond, or a bivalent organic group selected from the group consisting of --O--, --COO-- and --CONH--, R.sub.1 is a C.sub.2-22 straight chain alkylene group, and R.sub.2 is a cyclic group selected from the group consisting of an aromatic ring, an aliphatic ring, a heterocyclic ring and substituted forms of such rings.

Abstract: Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.