Abstract: The present invention provides a copolyimide characterized in that the copolyimide contains units represented by formulas (I) and (II) ##STR1## (wherein R.sub.0 represents an aromatic tetracarboxylic residue). The polyimide has excellent thermal dimensional stability, and can be fabricated by using conventional inexpensive materials.

Abstract: A new class of polyimides and copolyimides made from substituted benzidines and aromatic dianhydrides and other aromatic diamines. The polyimides obtained with said diamines are distinguished by excellent thermal, excellent solubility, excellent electrical properties such as very low dielectric constants, excellent clarity and mechanical properties making the polyimides ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular or gas separation, as fibers in molecular composites, as high tensile strength, high compression strength fibers, as film castable coatings, or as fabric components.

Abstract: Disclosed is a film of polyimide having repeating units of formula (1) and a birefringence (.DELTA.n) of at least 0.13: ##STR1## wherein R.sup.1 is an aromatic group having a valency of 4, at carbon atoms constituting the aromatic ring, and R.sup.2 is an aromatic group having a valency of 2, at carbon atoms constituting the aromatic ring. This polyimide film exhibits good thermal dimensional stability.

Abstract: A polyimide resin having a repeating unit of the formula: ##STR1## wherein R.sub.1 is a tetravalent organic group constituting a tetracarboxylic acid or its derivative, wherein four atoms directly bonded to the four carbonyl groups are carbon atoms having no unsaturated bond, and R.sub.2 is a bivalent organic group constituting a diamine.

Abstract: A polyamideimide having an inherent viscosity of above 0.48 which comprises a unit of the following formula (II) ##STR1## and a unit of the following formula (IV) ##STR2## as main units forming the molecular chains of the polyamideimide, and an intimate mixture of the polyamideimide and a plasticising material for the polyamideimide.

Abstract: A method for producing an imide oligomer soluble in an organic solvent by reacting three components of an aromatic tetracarboxylic acid or its derivative, an aromatic diamine and an end-capping agent, wherein the aromatic diamine is a condensation product of o-ethylamiline with formaldehyde, and the end-capping agent is an ethynyl phthalic acid of the formula: ##STR1## wherein R is a hydrogen atom or a monovalent group selected from the group consisting of an aliphatic group, an alicyclic group and an aromatic group, or its derivative.

Abstract: A polyimide coating composition comprising an homogeneous liquid solution of (a) a polyimide or polyimide precursor, (b) a substituted silane compound and (c) aprotic solvent.

Abstract: Polymides are made by imidization of the product of reaction of dianhydrides with diaminobenzotrifluoride and bis(trifluoromethyl) oxydianilines. In preferred embodiments the polyimides are end capped with monoanhydride or monoamine residues.

Abstract: The process of the present invention includes first treating a polyamide-acid (such as LARC-TPI polyamide-acid) in an amide-containing solvent (such as N-methylpyrrolidone) with an aprotic organic base (such as triethylamine), followed by dehydrating with an organic dehydrating agent (such as acetic anhydride). The level of crystallinity in the linear aromatic polyimide so produced is maximized without any degradation in the molecular weight thereof.

Abstract: Described herein are amide and/or imide containing polymers based on novel monomers that contain isoalkylidene bridges. These polymers have excellent toughness combined with high temperature stability, low water absorption, and good melt-fabricability.

Abstract: Disclosed is a process for continuously mixing two liquid components, whose one liquid component is a two-liquid curing type resin which comprises continuously supplying one liquid component under stirring into a mixing container and pouring the other liquid component into said container by pushing open a needle forcibly provided to a check valve, the improvement wherein said needle is pushed open with a non-curing liquid, thereafter, a curing liquid is poured into said mixing container. According to the present invention, when, for example, a polyamide acid and a curing agent are caused to mix and react with each other, a transparent polyimide mixed uniformly is obtained and high quality molded articles of polyimide are provided therefrom.

Abstract: Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.

Abstract: A polyimide-forming composition comprising(A) a polycarboxylic acid partial ester of formulaHOOC--R.sup.1 --COOR.sup.2 Iwhere R.sup.1 denotes a divalent ethylenically unsaturated aliphatic or cycloaliphatic group of 2 to 20 carbon atoms, and R.sup.2 denotes the residue, after removal of a hydroxyl group, of an alcohol having from 4 to 20 carbon atoms which has a cycloaliphatic, aromatic or heterocyclic ring and is polymerizable on heating in the presence of an acid,(B) a partial ester of formula I above in which R.sup.1 denotes a group of formula II ##STR1## where Ar.sup.1 denotes a tetravalent aromatic group of 6 to 20 carbon atoms linked through aromatic carbon atoms thereof to the indicated carbon atoms, and R.sup.2 is as defined above,(C) an aromatic primary polyamine and(D) a heat-activable substance which releases an acid at a temperature of 100.degree. C. or above.

Abstract: An aromatic polythioetherimide is disclosed, which comprises at least 50 mol % of a repeating unit represented by formula (I): ##STR1## wherein Ar is as defined in the specification, with the total of the repeating unit(s) being 100 mol %. The polythioetherimide has an excellent balance between heat resistance and mechanical properties as well as improved moldability.

Abstract: Novel polyimides and co-polyimides are prepared by the condensation polymerization of an aryl diamine with dioxydiphthalic anhydride or a mixture thereof with oxydiphthalic anhydride. The polyimides and co-polyimides prepared exhibit a low moisture absorption and improved dielectric properties and can be tailored to provide a composition having desirable mechanical properties, specifically, rigidity.

Abstract: Disclosed is a substantially fully imidized diglyme-insoluble, N-methylpyrrolidone-soluble polyimidesiloxane which is the reaction product of a dianhydride, about 1 to about 5% by weight of a mono-anhydride, and a mixture of about 20 to about 50% by weight siloxane diamine and about 50 to about 70% by weight non-siloxane diamine. The non-siloxane diamine is a mixture of about 33 to about 50 mole percent of a first diamine having the general formula ##STR1## and about 50 to about 67 mole percent of a second diamine having the general formula ##STR2## were each "X" is independently selected from hydrogen and halogen and each "Y" is independently selected from --CH.sub.2 --, ##STR3## The polyimidesiloxanes are very useful in coating wire, cable, and circuit boards.

Abstract: A carbinol-containing polyimide oligomer terminated with epoxide-reactive end groups has the structure ##STR1## wherein Ar is ##STR2## R.sup.1 and R.sup.2 are independently divalent organic radicals; R.sup.3 is a trivalent organic radical; Y is an epoxide-reactive group (e.g.); m is 0 or 1 and n is 0-10. Suitable epoxide-reactive groups include a phenol, thiol, amine, or carboxyl group. Polyimide-polyepoxide adducts are prepared by reacting the polyimides with a polyepoxide, preferably a diepoxide used in excess. The polyimide oligomers are useful as coatings or adhesives. The adducts are useful as adhesives, for composites, and particularly for impregnating the fiberglass sheets which are used to form circuit boards.

Abstract: The present invention provides a curable composition which is cured at a relatively low temperature and, when cured, exhibits excellent physical properties. The curable composition comprises;(A) a compound having a carboxylic anhydride group,(B) a polyfunctional amine compound, a polyfunctional hydroxyl group-containing compound, a compound having both an amino group and a hydroxyl group or a compound latently having an amino group and/or a hydroxyl group, and(C) a polyhydric metal chelate compound or a polyhydric metal alcoholate compound.

Abstract: A compound represented by the following general formula [1]: ##STR1## wherein R.sub.3 and R.sub.4 are independently selected from hydrogen and alkyl groups having 1 to 4 carbon groups,is valuable as an endcapping agent for a polyimide. Namely, a PMR polyimide varnish comprising this compound, a dialkyl tetracarboxylate represented by the following general formula [2]: ##STR2## wherein R.sub.1 is a direct bond or stands for CH.sub.2, O, CO, SO.sub.2, S or C(CH.sub.3).sub.2 and X stands for an alkyl group having 1 to 4 carbon atoms,and a diamine represented by the following general formula [3]: ##STR3## wherein R.sub.2 is a direct bond or stands for CH.sub.2, O, CO, SO.sub.2 S or C(CH.sub.3).sub.2,has a good storage stability and is especially valuable as a matrix resin to be incorporated in a fiber-reinforced composite material.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, wherein at least one of said diamine monomers is a 12F-Diamine or 12F-Oxydiamine containing at least two CF.sub.3 ##STR1## R groups linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degredation.

Abstract: A process for producing a silicon-containing polyamic acid affording a silicon-containing polyimide having a low thermal expansion coefficient and a process for producing the silicon-containing polyimide are provided, the former process comprising reacting pyromellitic acid dianhydride (A.sup.1 mols) and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (A.sup.2 mols) with a diamine of the following formula (I) (B mols) and an aminosilicon compound of the formula (II) so as to satisfy the following expressions (III) and (IV): ##STR1## wherein R.sup.1 is methyl, ethyl, methoxy, ethoxy or halogen; R.sup.2 is alkyl or alkyl-substituted phenyl; X is a hydrolyzable alkoxy, acetoxy or halogen; m is 0, 1 or 2; n is 1 or 2; and k is 1, 2 or 3; andthe latter process comprising baking a solution of the above silicon-containing polyamic acid at 50.degree. to 500.degree. C.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, at least one of said diamine monomers containing the group ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

Abstract: The present invention provides for shaped articles made from novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attach by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one of more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

Abstract: A polyamideimide having an inherent viscosity of above 0.48 which comprises a unit of the following formula (II) ##STR1## and a unit of the following formula (IV) ##STR2## as main units forming the molecular chains of the polyamideimide, and an intimate mixture of the polyamideimide and a plasticizing material for the polyamideimide.

Abstract: A polyimide copolymer having a repeating unit of formula (I): ##STR1## wherein each of R.sub.1 and R.sub.2 is independently ##STR2## and R.sub.1 and R.sub.2 are different from each other, R.sub.0 is an aromatic group having a valency of 4, and m is a positive integer. The polyimide copolymer is excellent in heat resistance, mechanical properties (e.g., tensile elongation) and thermal dimensional stability.

Abstract: An aromatic hetero ring-containing polyimide comprising substantially equal equivalent amount of (1) structural units of Group 1 and (2) structural units of Group 2, wherein the structural units of Group 1 comprise (i) from 30 to 100 mol % of a unit of the formula: ##STR1## wherein X is S, O or NH, and (ii) from 0 to 70 mol % of a unit of the formula: ##STR2## wherein Ar.sub.1 is ##STR3## wherein each of y, y.sub.1, and y.sub.2 and y.sub.3 is a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and each of Z, Z.sub.1 and Z.sub.2 is a single bond, --O--, --CH.sub.2 --, ##STR4## --C--, --SO.sub.2 --, --C(CH.sub.3).sub.2 -- or --C(CF.sub.3).sub.2, and the structural units of Group 2 comprise (i) from 70 to 100 mol % of a unit of the formula: ##STR5## and (ii) from 0 to 30 mol % of a unit of the formula: ##STR6## wherein Ar.sub.2 is ##STR7## wherein Z, y and y.sub.

Abstract: Partially soluble, film-forming polyimides and their copolymers made using 3,5-diaminobenzotrifluoride are described. Thin films and coatings of these materials are relatively colorless and the polymers have a high Tg, excellent thermal stability, lower moisture uptake, and lower dielectric constant. They are useful as films, fibers, molded articles and as protective coatings, interlevel dielectrics, electric circuit substrates and the like for the electronics industry.

Abstract: Polyetherimide precursor compositions are prepared by a reacting mixture of at least two diamines selected from the group consisting of o-phenylenediamine, m-phenylenediamine and 4-aminophenyl ether with the esterification product of a low molecular weight alkanol such as methanol and an ether tetracarboxylic acid dianhydride, preferably 3,4-dicarboxyphenyl ether dianhydride. Said polyimide precursor compositions may be converted to polyimides useful in composite formation, by gently heating to remove excess alkanol and subsequently baking at temperatures in the range of about 275.degree.-375.degree. C.

Abstract: A composition for the application of a planar polyimide coating having a glass transition temperature above 300.degree. C. comprises a solution in an anhydrous, aprotic solvent of an aromatic diamine and a dialkyldihydrogen pyromellitate which is more than 90% meta isomer.

Abstract: A process for making thermoplastic polyimides which involves reacting an aromatic dianhydride with an organic diamine in the presence of a tertiary amine in an inert solvent to form a polyamide acid salt; separating the polyamide acid salt from the solvent; and heating the polyamide acid salt under imidization conditions to form the desired polyimide.

Abstract: Novel copolyimides are prepared by reacting one or more aromatic dianhydrides with a meta-substituted phenylene diamine and an aromatic bridged diamine. The incorporation of meta-substituted phenylene diamine derived units and bridged aromatic diamine derived units into the linear aromatic polymer backbone results in a copolyimide of improved flexibility, processability, and melt-flow characteristics. The novel copolyimides are especially useful as thermoplastic hot-melt adhesives.

Abstract: A composition for use in a process for the deposition of patterned thin metal films on integrated circuit substrates, the composition comprising an admixture of a thermoplastic polyimide resin and a coumarin dye dissolved in a substituted phenol solvent. Optionally a polar solvent having a boiling point greater than 160.degree. C. and a low boiling organic compound (70.degree.-150.degree. C.) may be incorporated in the composition.

Abstract: A process for forming a built-up film with logic polymers whose film inherently cannot be readily obtained by LB technique comprises modifying the high polymers, and if required, further cyclizing the product partially or wholly. The produced thin films have extremely excellent heat resistance, good chemical resistance and mechanical characteristics and their thickness is so small that it is generally hardly attainable, that is, less than 10,000 .ANG., or if desired, 10 to 1000 .ANG..

Abstract: Oligomeric and/or polymeric radiation-reactive polyimidazole and polyimidazo pyrrolone precursors which are soluble in organic solvents, can be prepared with high purity, i.e., especially without chloride, in a simple manner if an aromatic and/or heterocyclic tetraamino compound is reacted in the presence of a carbodiimide, with an olefinically unsaturated monocarboxylic acid and a dicarboxylic acid, or with an olefinically unsaturated monocarboxylic acid and an aromatic and/or heterocyclic tetracarboxylic acid dianhydride, or with an olefinically unsaturated tetracarboxylic acid diester, in the form of an addition product of the tetracarboxylic acid dianhydride and an olefinically unsaturated alcohol. The radiation-reactive precursors prepared in this manner are suitable, for instance, for the manufacture of highly heat-resistant relief structures.

Abstract: A curable composition comprising (a) a curable polyimide soluble in organic solvents and (b) a polymerization initiator as essential components, said polyimide consisting of recurring units represented by the formula ##STR1## wherein, each of X, X.sub.1, X.sub.2, X.sub.3 and X.sub.4 is a tetravalent carbocyclic or heterocyclic residue, each of Y.sub.1, Y.sub.2, and Y.sub.3 is a divalent carbocylic or heterocyclic residue, at least one of Z.sub.1 and Z.sub.2 is a residue having a reactive carbon-carbon double bond, and each of l, m, and n is an integer from 0 to 20, preferably from 0 to 10. The polyimide may include (a) polyacrylate compounds (b) bis-imide compounds (c) photosensitive polyimide precursors (d) oxime initiators (e) a 3 component sensitizer of a phenone compound, a mercapto compound, and an arylamine-alkanol, or mixtures of a,b,c,d, and e.

Abstract: Condensation polymers of high molecular weight, such as polymers, polyureas, and polyamides, are usually prepared at temperatures of 200.degree. C. or greater. However, by utilizing the catalyst system of the present invention condensation polymers can be synthesized at much lower temperatures. These catalyst systems are comprised of (1) a silicon-phosphorus composition which contains at least one divalent oxygen atom which is bonded directly to a tetravalent silicon atom and a trivalent or pentavalent phosphorus atom; and (2) at least one acid acceptor. For example, P(OSiR.sub.3).sub.3 wherein R can be an aliphatic or aromatic hydrocarbon radical, can be used in conjunction with a basic solvent as a catalyst system. Polymeric agents having pendant diphenylphosphine dichloride groups can also be used in conjunction with an acid acceptor as a catalyst system.

Abstract: Novel polymers and molding compositions are prepared from acyl halide derivatives of tricarboxylic acids and diamines and about 1 to about 10 percent by weight of phthalic anhydride, trimellitic anhydride or aniline moieties. The polymers are useful in engineering plastics.

Abstract: A process for preparing a polyamide which comprises polycondensing a dicarboxylic acid and a diamine by using a combination of at least one phosphine and at least one disulfide as the condensing agent.

Abstract: A liquid crystal aligning agent consisting essentially of a polyimide resin obtained by the polymerization of a diamine, a tetracarboxylic acid dianhydride and a monoamine of the formula:R.sup.2 (R.sup.1).sub.n NH.sub.2 (I)wherein R.sup.1 is a divalent organic group, R.sup.2 is an alkyl group having from 6 to 20 carbon atoms, and n is 0 or 1.

Abstract: An organic silicon-terminated polyimide precursor having a very stable solution viscosity is produced by polycondensing 100 parts by weight of a mixture composed of 90 to 99.5% by mole of an organic diamine represented by the following general formula (I) and 10 to 0.5% by weight by mole of an organic silyl represented by the following general formula (II): ##STR1## wherein R.sup.1 and R.sup.2 are divalent organic groups; R.sup.3 and R.sup.4 are monovalent organic groups; m is 0, 1, 2, or 3, with an organic tetracarboxylic acid dianhydride represented by the following general formula (III) in a molar amount corresponding to the 100 parts by weight of the mixture of the organic diamine and the organic silyl represented by the said general formulae (I) and (II), respectively, in an organic polar solvent at 0.degree. to 40.degree. C., thereby obtaining a solution of organic silicon-terminated polyimide precursor, and heating the solution at 50.degree. to 80.degree. C.: ##STR2## wherein R.sup.

Abstract: Polyetheramideimide is provided and method for making. There are utilized aromatic bis(etheranhydride) and diaminobenzanilide or mixtures thereof with an organicdiamine. The polyetheramideimide has been found to have improved solvent resistance.

Abstract: Polyimides or poly(amide-imides), especially those containing a polysiloxane unit are improved by heating such polymers or their polyamic acid precursors with a polyfunctional aromatic compound. The polyfunctional aromatic compound is one which contains at least two reactive groups which may be --NH.sub.2, --COOH, --OH or secondary amino groups with at least one of the reactive groups being --NH.sub.2 or --COOH.

Abstract: Described herein are amide and/or imide containing polymers based on novel monomers that contain isoalkylidene bridges. These polymers have excellent toughness combined with high temperature stability, low water absorption, and good melt-fabricability.

Abstract: A multilayer laminate having at least one layer of a no longer formable fully aromatic polyimide and at least one layer of substrate material, the layer of no longer formable polyimide adhering directly on one side to the layer of substrate material with a peel strength of at least 4.0 N.cm. The layer of no longer also formable polyimide is also insoluble in phenolic solvents, has a tensile strength of from 100 to 150 N.mm.sup.2, a breaking elongation of from 15 to 100%, a dielectric dissipation factor of from 1.5.times.10.sup.-3 at 1 Khz. Additionally, a layer of heat-sealable high-temperature adhesive selected from the class of polyacrylates, polysulfone resins, epoxy resins, fluoropolymer resins, silicone resins or butyl rubbers is joined to that side of the polyimide layer which is remote from the substrate material.

Abstract: A multilayer laminate having at least one layer of a no longer formable fully aromatic polyimide and at least one layer of substrate material, the layer of no longer formable polyimide adhering directly on one side to the layer of substrate material with a peel strength of at least 4.0 N/cm. The layer of no longer also formable polyimide is also insoluble in phenolic solvents, has a tensile strength of from 100 to 150 N/mm.sup.2, a breaking elongation of from 15 to 100%, a dielectric dissipation factor of from 1.5.times.10.sup.-3 to 5.times.10.sup.-3 at 1 kHz. Additionally, a layer of heat-sealable high-temperature adhesive selected from the class of polyacrylates, polysulfone resins, epoxy resins, fluoropolymer resins, silicone resins or butyl rubbers is joined to that side of the polyimide layer which is remote from the substrate material.

Abstract: A process for making polyetherimides involving reacting an aromatic bis(ether anhydride) with an organic diamine in the presence of a solvent so as to form a polyamide acid. The polyamide acid is thereafter polymerized in a solid state at a temperature below the glass transition temperature of the final polyetherimide.

Abstract: The present invention provides a process for the production of random copolymers containing repeating polyimide units and repeating polyetherimide units. The process is a reverse addition process and utilizes at least two dianhydrides of varying reactivity.

Abstract: A method for making an electrical inductive device for use in hermetic atmospheres which incorporate refrigerants such as halogenated methane compositions, for example refrigerant R-22, monochlorodifluoromethane. The device may be a wound coil device formed of magnet wire, the enamel coating of which has resistance to blistering when exposed to refrigerants under saturated conditions at temperatures up to about 200.degree. or 210.degree. C. and above. The enamel coating composition or wire enamel is formed as the reaction product of 1,2,3,4-butanetetracarboxylic dianhydride, optionally with an aromatic dianhydride, and a diamine such as p,p'-methylenedianiline or p,p'-oxydianiline, in an organic solvent such as N-methyl-2-pyrrolidone.

Abstract: A liquid crystal aligning agent consisting essentially of a polyimide resin obtained by the polymerization of a diamine, a tetracarboxylic acid dianhydride and a monoamine of the formula:R.sup.2 (R.sup.1).sub.n NH.sub.2 (I)wherein R.sup.1 is a divalent organic group, R.sup.2 is an alkyl group having from 6 to 20 carbon atoms, and n is 0 or 1.