Abstract: The invention relates to poly(tertiary di- or polyarylamines) which have more than one aryl moiety which is further substituted with a moiety capable of chain extension or crosslinking. In another aspect, the invention relates to poly(tertiary di- or polyarylamines) which have more than one aryl moiety which is further substituted with a moiety capable of chain extension or crosslinking which are partially or completely crosslinked or chain extended. The invention further relates to films prepared from such chain extended or crosslinked poly(tertiary di- or polyarylamines). The invention further relates to electrophotographic devices and electroluminescent devices, such as polymeric light-emitting diodes, containing such films.

Abstract: A process for the preparation of polyester-imide resin of the formula ##STR1## wherein n represents the number of segments present and is a number of from about 10 to about 10,000; R' is alkyl or alkylene; and R is independently an oxyalkylene or a polyoxyalkylene by the reaction of trimellitic acid, or a trimellitic anhydride, a glycol and a diamine of the formula ##STR2## wherein R represents a hydrogen or alkyl group; and n represents the number of monomer segments, and is a number of from about 1 to about 10, and which reaction is accomplished by heating the aforementioned components.

Abstract: An addition type polyimide resin raw material composition having high heat resistance and high corrosion resistance comprising a tetracarboxylic anhydride and/or tetracarboxylic diester compound, diamine compound and exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride and/or exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic monoester compound; a composition containing a prepreg; a fiber-reinforced polyimide composite prepreg, coating material and paint using them; and a curing method thereof.

Abstract: A photosensitive resin composition comprising;(A) a polyimide precursor containing an acrylic or methacrylic group;(B) a tertiary amine compound represented by the general formula: ##STR1## wherein R.sup.6 is a monovalent organic group having 3 or less carbon atoms, R.sup.7 is a divalent organic group having 3 or less carbon atoms, and R.sup.8 is a hydrogen atom or a methyl group; and(C) at least one of a photopolymerization initiator and a sensitizer.This composition has a sufficient sensitivity even when thick films are formed, has a superior developability in an aqueous alkali solution, and is suited for the formation of polyimide patterns.

Abstract: Copolyetherimides are prepared by the reaction of an alkali metal salt of a dihydroxyaromatic compound with a bis(substituted phthalimide) and a third compound which may be a substituted aromatic ketone or sulfone or a macrocyclic polycarbonate or polyarylate oligomer. The reaction takes place the in presence of a solvent and a phase transfer catalyst having high thermal stability, such as a hexaalkylguanidinium halide. Random or block copolymers may be obtained, depending on the reaction conditions.

Abstract: Improved process for producing a polybenzimidazole compound in solution by dissolving a fully dried polybenzimidazole of the following general formula (1) or (2) in N,N-dimethylacetamide of a sufficiently reduced water content at an elevated temperature of 260.degree. C. or higher in an inert gas atmosphere and a solution of the polybenzimidazole compound produced by the process. The solution remains useful for an extended time without using metal salts or any other stabilizers: ##STR1## where R.sup.1, R.sup.2 and R.sup.5 are tetra-, di- and trivalent aromatic groups, respectively; R.sup.3, R.sup.4 and R.sup.6 are each independently a hydrogen atom, an alkyl group or an aryl group; n is an integer of 2 or more.

Abstract: Poly (organophosphazene) polymers bearing various ratios of a carboxylic acid containing sidegroup and an alkylamino, alkoxy, or alkoxy ether sidegroup are disclosed. These water-soluble macromolecules are cross-linked and allowed to absorb water to form hydrogels. Because of their anionic character and high water content, the polymeric hydrogels are useful for a wide variety of biomedical applications including controlled drug delivery (e.g. pH sensitive drug delivery), biocompatible coatings, and pH sensitive membranes.

Abstract: Water-soluble formaldehyde-free polycondensation products based on amino-s-triazines with at least two amino groups and glyoxylic acid, which contain as further component at least one amino compound and where the molar ratio of amino-s-triazine to glyoxylic acid to amino compound is 1:0.5 to 6.0:0.1 to 2.0. These polycondensation products are excellently suited as additives for aqueous suspensions of inorganic binders, especially cement, lime and gypsum. Building material mixtures which contain these polycondensation products remain workable for a considerably longer time and, in spite of this, also set more quickly.

Abstract: 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.

Abstract: Novel polyimide copolymers containing ether linkages were prepared by the reaction of an equimolar amount of dianhydride and a combination of diamines. The polyimide copolymers described herein possess the unique features of low moisture uptake, dimensional stability, good mechanical properties, and moderate glass transition temperatures. These materials have potential application as encapsulants and interlayer dielectrics.

Abstract: A rigid, aromatic polyimide composition prepared using a solution imidization process from an aromatic tetracarboxylic dianhydride and a diamine which is greater than 60 mole % to about 85 mole % p-phenylene diamine and 15 mole % to less than 40 mole % m-phenylene diamine exhibits exceptional tensile properties and thermal oxidative stability.

Abstract: The present invention relates to a process for the preparation of branched and/or crosslinked polyamino-ethers in which polyamino-ethers, which are prepared from glycol dichlorohydrins or polyglycol dichlorohydrins and diamines and still contain free chlorohydrin groups, are crosslinked in an essentially aqueous solution under alkaline conditions under the influence of heat.

Abstract: A method for synthesizing 1,4-bis(4-aminophenoxy)naphthalene and a series of polyamides, polyimides and copoly(amide-imide)s derived from the said compound is disclosed. These polymers possess excellent thermal stability and mechanical strength.

Abstract: A magnetic recording medium has a substrate and an non-magnetic underlayer formed on the substrate and a magnetic layer formed on the non-magnetic layer. The magnetic layer include a magnetic powder and a binder for binding the magnetic powder on the non-magnetic layer. The binder includes at least a resin component containing at least an aminoquinone structure selected from an aminoquinone structure group shown with formulas (1-1) and (1-2) as a constitutional unit. As the magnetic powder, a metal magnetic powder mainly made of Fe and having a saturation magnetization .sigma.s is used. The magnetic layer has a saturation flux density Bm of 3500 to 5000 G and a coercive force of 1800 to 3000 Oe and a surface roughness SRa of 1 to 10 nm and a thickness of not more than 1.0 .mu.m.

Abstract: Pyrrolidonyl-containing polyesters and polyamides I to III ##STR1## where R, X, A and Z are defined herein, are suitable as film formers and conditioners in hair-cosmetic formulations, for stabilizing hydrogen-peroxide in aqueous solution, for complexing iodine, as tablet binders and as a constituent of film coatings in pharmaceutical preparations, for enzyme and bleach stabilization in detergent formulations, as an auxiliary in the production and finishing of textiles, as a solubilizer and protective colloid in the preparation and stabilization of polymer dispersions, and as an adhesive raw material.

Abstract: Polyimide copolymers were prepared by reacting different ratios of 3,4'-oxydianiline (ODA) and 1,3-bis(3-aminophenoxy)benzene (APB) with 3,3',4,4'-biphenylcarboxylic dianhydride (BPDA) and endcapping with an effective amount of a non-reactive endcapper. Within a narrow ratio of diamines, from .sup..about. 50% ODA/50% APB to .sup..about. 95% ODA/5% APB, the copolyimides prepared with BPDA have a unique combination of properties that make them very attractive for various applications. This unique combination of properties includes low pressure processing (200 psi and below), long term melt stability (several hours at 390.degree. C.), improved toughness, improved solvent resistance, improved adhesive properties, and improved composite mechanical properties.

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: 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: 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: This invention relates to methods for preparing novel, solid-phase transfer reagents, specifically phosgenated oxime resins and non-symmetrical ureas, that are useful as supports in combinatorial synthesis for the creation of libraries of compounds for lead identification.

Abstract: A photosensitive resin composition comprising, as its main ingredient, a poly(amic acid) resin constituted of a diamino compound represented by formula: ##STR1## and optionally used other diamino compound and a tetracarboxylic acid dianhydride as its constituent monomers and/or a poly(amic acid) ester resin obtained by esterifying said poly(amic acid) resin and/or a polyimide resin obtained by a dehydrating or alcohol-eliminating ring-closure reaction of said poly(amic acid) resin or poly(amic acid) ester resin has an excellent developability and a high film strength and can form a relief patter of low thermal expansion.

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: Disclosed is a gas barrier coating and multilayer packaging materials made therefrom. The gas barrier coating includes a polyamine (A), a polyepoxide (B), and a filler (C). Polyamine (A) includes at least one of the following: (a) an initial polyamine, and (b) an ungelled polyamine adduct which is the reaction product of the initial polyamine and epichlorohydrin and/or a polyepoxide having a plurality of glycidyl groups linked to an aromatic member. Polyepoxide (B) includes a polyepoxide having a plurality of glycidyl groups linked to an aromatic member. Filler (C) includes a platelet-type filler with the following particle size distribution: (a) a number mean particle diameter in the range from about 5.5 to about 15 microns, and (b) a volume mean particle diameter in the range from about 8 to about 25 microns. In addition, the present invention provides glossy, multilayer packaging materials containing an oxygen barrier material layer having an oxygen permeability constant not more than 0.

Abstract: A method of producing a polyamide resin by reacting 1 mol of linear polyester resin (as calculated in repeating unit of the linear polyester resin) consisting of at least one dicarboxylic acid component and at least one diol component and having an intrinsic viscosity of not less than 0.2 dl/g with 0.5-1.5 mol of at least one diamine compound in a reaction medium comprising at least one solvent which is selected from the group consisting of hydrocarbons, halogenated hydrocarbons, ethers and acetals, so that the diol component of the linear polyester resin is substituted by the diamine compound to provide the polyamide resin as a reaction product.

Abstract: Stripping fingers for use in a copying machine formed from a resin composition comprising 50-90% by weight of a thermoplastic polyimide resin, and 10-50% by weight of titanium oxide whiskers or zinc oxide whiskers. They may be formed from a resin composition comprising 50-80% by weight of a thermoplastic polyimide resin, 10-40% by weight of titanium oxide whiskers or zinc oxide whiskers, and 2-15% by weight of aromatic polyamide resin powder.

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: 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: 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 sliding material and a heat resistant filament which primarily comprises a liquid crystal polyimide, a liquid crystal polyamide or a liquid crystal polyamide-imide copolymer having at least one recurring structural unit selected from the formula (1) and the formula (2) and is excellent in heat resistance, mechanical characteristics and other fundamental properties of polyimides, and relates to significant improvement of heat-resistance by heat-treating the sliding material, the filament and the molded items. The liquid crystal polyamide-imide copolymer which comprises in a polymer molecule 0.05.about.0.95 mole ratio of the recurring structural units of the formula (1) and 0.95.about.0.

Abstract: A diamine which is useful in preparing a new flexible polyamide and polyimide with an aromatic dicarboxylic acid and a tetracarboxylic dianhydrides, respectively, has a general formula as follows: ##STR1## wherein R.sub.1 is a proton (--H) or methyl (--CH.sub.3) and n is an integer ranging from 1 to 4. These polyamide and polyimide exhibit good mechanical performance and processability.

Abstract: The present invention relates to a new polyesterimide of the type containing ester repeat functional groups E=--CO--O--, imide repeat functional groups I: ##STR1## and at least one chromophore, characterized in that it contains a quantity of recurrent amide functional groups capable of ring closure to imides which is smaller than or equal to 5 mol % relative to the sum of the imide functional groups and of the amide functional groups capable of ring closure to imides, which are present, and in that the polymerization functional groups consist essentially of E functional groups.This polyesterimide is preferably free from amide functional groups capable of ring closure to imides.One of the processes for obtaining this polyesterimide constitutes another subject-matter of the invention.Such a polymer is advantageously capable of behaving like a material that is transparent and/or active in nonlinear optics.

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: A process for making polyimide composition comprising reacting at least one diamine, at least one tetracarboxylic diacid diester, selected phosphoramide and at least one base catalyst to form at least one polyimide compound, said reaction carried out at a temperature from about 20.degree. C. to about 60.degree. C. and wherein the molar ratio of diamine:tetracarboxylic diacid diester:phosphoramide:base catalyst is in the range of 0.8-1.2:1:2.5-4.0:2.5-4.0.

Abstract: A process for producing a polyimide composition by reacting at least one polyamic acid or at least one polyamic ester or a mixture of at least one polyamic acid and at least one polyamic ester with a selected phosphoramide in the presence of at least one base catalyst to from a polyimide composition.

Abstract: A functionalized polymer comprising a polymeric segment, having at least one cyclic amine end group, defined according to formula (I) ##STR1## where Z is an anionically-polymerized polymer; R.sub.1 is selected from the group consisting of organic groups containing from 1 to about 12 carbon atoms and a bridging bond; each R.sub.2 is independently selected from the group consisting of hydrogen, organic groups containing from 1 to about 12 carbon atoms, and a bridging bond; each R.sub.3 is independently selected from the group consisting of hydrogen and organic groups containing from 1 to about 12 carbon atoms; a is an integer from 4 to about 16; and b is an integer from 0 to about 12; and optionally including a bridge, formed by the selection of two of said bridging bonds, the bridge having 0 to about 6 carbon atoms between the bridging ring members; said polymer having been crosslinked. Also provided are vulcanizable compositions of matter, vulcanizates, and tires of the functionalized polymers.

Abstract: There are provided a polyamic acid obtainable by reacting a diamine compound of the formula (1) ##STR1## wherein R.sup.1 is an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms or a halogen atom, each of X and Y is independently a divalent linking group,with a tetracarboxylic acid dianhydride; a polyimide obtainable by dehydrating and ring-closing the above polyamic acid; and a liquid crystal aligning agent containing the above polyamic acid and/or the above polyimide.

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 generally to a new adhesive comprising a vinyl containing siloxane-containing polyimide for use in TSM capping of electronic package assemblies with adhesive capability of providing a seal band width of less than 4mm and even less than 2mm, solubility in non-toxic and environmentally safe solvents and durable adhesive properties and to a method for making the polyimides, a method for using the polyimides to make electronic packages and electronic packages made using the adhesive. The preferred vinyl-containing siloxane containing polyimide is a block type polymer containing blocks of a dianhydride-aromatic diamine oligomeric reaction product joined by non-vinyl/vinyl containing siloxane diamine forming links.

Abstract: Disclosed is a process which comprises reacting a polyimide precursor with borane. Also disclosed is a thermal ink jet printhead containing a layer comprising the product of this reaction.

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: Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine.

Abstract: A polyimide precursor composition, which comprises, a polyamic acid having a repeating unit represented by the following general formula (PA), and at least one kinds of cure accelerator selected from the group consisting of a substituted or unsubstituted nitrogen-containing heterocyclic compound exhibiting an acid dissociation index "pKa" of a proton complex ranging from 0 to 8 in an aqueous solution thereof, or an N-oxide compound of said nitrogen-containing heterocyclic compound (AC1), a substituted or unsubstituted amino acid compound (AC2), and an aromatic hydrocarbon compound or an aromatic heterocyclic compound having a molecular weight of 1,000 or less and two or more hydroxyl groups (AC3): ##STR1## wherein .phi. is a quadrivalent organic group, .phi. is a bivalent organic group, R is a substituted or unsubstituted hydrocarbon group, organosilicic group or hydrogen atom.

Abstract: Photosensitive polyimides (Ps-PIM) materials have been synthesized that belong to three families of Ps-PIM materials. Through the use of precursors, various catalytic compositions with differing photosensitivities are provided. The results are Ps-PIM materials having increased photosensitivities at wavelengths longer than approximately 330 to 350 nm and an associated catalytic system that is insensitive to oxygen. A variety of applications, including use in holographic systems, are improved by the present invention.

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: The invention provides reaction products of:(A) an acylating reagent, with(D) a polyalkenyl derivative of an ethylenically unsaturated carboxylic reagent (C), and(E) a polyamine containing at least two --NH.sub.2 and/or --NH groups, or with(F) the pre-formed product of reagents (D) and (E), wherein the acylating reagent (A) is the reaction product of(B) a C.sub.4 -C.sub.20 polyene or oligomer prepared therefrom, and(C) an ethylenically unsaturated carboxylic reagent; lubricating oil compositions, fuel compositions and additive concentrates containing them; and use of the reaction products as dispersant additives.

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: A dope for cast formation comprising a fluorine including polyimide resin and an organic solvent (P) as main components. The fluorine including polyimide resin has at least one --CF.sub.3 group in the repeating molecular unit. The organic solvent (P) is present during the resin polymerization of the fluorine including polyimide resin. The organic solvent (P) is diethylene glycol dimethyl ether.