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: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid ester with the following structure:G--O--CO--R*--CO--O--G,where G is an (optionally substituted) succinimide or maleinimide group and R* is the parent body of the dicarboxylic acid.

Abstract: The present invention relates to an aromatic polyamide pulp and its preparing process which has both excellent physical properties and high degree of polymerization wherein aromatic diamine is reacted with aromatic diacid chloride in amides and/or urea-based polymerization solvent containing inorganic salts and/or a little of Lewis acid compound. The present invention can easily provide the pulp of high polymerization degree and high orientation by stirrer in the continuous transferable polymerization-orientation-gelation apparatus within a short time without use of a tertiary amine affecting human body and without regard to isotropic or anisotropic, and continuous or uncontinuous ejection.

Abstract: A process for the activated anionic lactam polymerization is proposed, wherein a liquid system is employed, which simultaneously contains activator and anionic catalyst for the polymerization of the lactam.

Abstract: A method for producing poly-o-hydroxy amides by heating a dicarboxylic acid to a temperature .gtoreq.80.degree. C., together with a sulfonic acid chloride and a tertiary amine in a suitable solvent, to form a reaction mixture and reacting the mixture obtained with a bis-o-aminophenol solution at a temperature <80.degree. C.

Abstract: A continuous process for activated anionic lactam polymerization is proposed, wherein a liquid system is employed, which simultaneously contains activator and anionic catalyst for the polymerization of lactam.

Abstract: A method for the anionic polymerization of a lactam which produces an nylon having a surface resistivity of between about 10.sup.6 to about 10.sup.12 .OMEGA./.quadrature.. Miscible antistatic agents are mixed with the lactam and the moisture concentration in the lactam is adjusted to about 0.4 wt %. When required to complete the polymerization, the initiator concentration in the lactam is adjusted to about 1 wt %.

Abstract: Disclosed are cosmetic melanins of different colors produced by procedures involving oxidative polymerization of monomeric precursors of melanin and/or co-monomers that enhance substantivity or adherence of the melanins to the skin and hair. Also disclosed are methods for preparing cosmetic melanins and methods for using these compositions topically to produce a natural-appearing tan and to prevent damage to skin caused by UV exposure.

Abstract: Polyimide precursor solutions comprise an organic liquid and the reaction product of an aromatic dianhydride and an aromatic diaminobenzoxazole capped, on at least one terminal end, with a bifunctional chain extender. The bifunctional chain extender has one functional group reactive with the amine of the aromatic diaminobenzoxazole or the anhydride of the aromatic dianhydride and another functional group which does not form amic acid linkages, but which is capable of further reaction to increase the molecular weight of the polyimide precursor under conditions other than those used to react the aromatic diamine and aromatic dianhydride to form the polyimide precursor. These polyimide precursors can be converted into polyimidebenzoxazole polymers.

Abstract: A polyamide comprising a solution of (i) an aliphatic polyamide and/or an aliphatic aromatic poly amide dissolved in (ii) N-methyl-2-pyrrolidone and containing (iii) calcium chloride, the ratio between the polyamide (i) and the N-methyl-2-pyrrolidone (ii) in the solution composition being 3 to 25% by weight of the polyamide (i)to 97 to 75% by weight of the N-methyl-2-pyrrolidone, (ii) with the solution also containing calcium chloride (iii) in an amount of 5 to 60 parts by weight based on 100 parts by weight of the polyamide (i) which can be precipitated in a precipitant consisting essentially of water while stirring the precipitant to provide fibrids, which then can be mixed with fibers or natural pulp and formed into synthetic paper.

Abstract: A random copolymerized polyamide resin is prepared by reacting a lactam of the formula (I): ##STR1## wherein R.sup.1 is a C.sub.2-11 alkylene group optionally substituted with a substituent having 1 to 6 carbon atoms, with a hexamethylenediamine-adipic acid salt while concentrating the aqueous solution of the salt to a concentration of at least 70% by weight and while maintaining a uniform reaction phase at all times by controlling the pressure over and the temperature of the reaction medium such that the hexamethylenediamine-adipic acid salt does not precipitate, said pressure being up to not greater than 2 kg/cm.sup.2 .multidot.G and said temperature being up to not greater than 150.degree. C., and then mixing in the solution of the lactam of formula (I) thereby effecting copolymerization and forming a polyamide resin having a relative viscosity measured by the sulfuric acid solution method (1% at 25.degree. C.) of 1.5 to 8.0.

Abstract: A curable resin system in supercritical carbon dioxide as diluent includes an epoxy resin, a co-reactant selected from poly N-substituted aziridines, and a catalyst to promote cure at ambient temperature. The system is compatible with various epoxy resins such as bisphenol A epoxy, bisphenol F epoxy, novolac epoxy, cycloaliphatic epoxy, triglycidyl-aminophenol, and triglycidyl isocyanurate. The aziridine co-reactant may be selected from reaction products of NH aziridines with acrylates and methacrylates of trimethylolpropane, ethylene glycol, propylene glycol, bisphenol A, bisphenol F, pentaerythritol, glycerol, and their alkoxylated derivatives; reaction products of NH aziridines with epoxy compounds; and 1-aziridine ethanol and its reaction products with epoxy and isocyanate functional compounds. Suitable catalysts include acid salts and complexes, strong electron accepting compounds, combinations of silicon hydrides and metal complexes, and non-halogen containing boron derivatives.

Abstract: Process for the preparation of polyimides or of their polypeptide hydrolysates which are at least 80% biodegradable, by thermal polycondensation of at least one amino acid, optionally followed by hydrolysis, the thermal polycondensation step being carried out in the presence of at least one "acid catalyst" chosen fromsulphuric, nitric, phosphorous, sulphurous, hydrofluoric, silicic and sulphonic acids, organic sulphonic acids containing less than 50 carbon atoms, amino acids bearing a non-carboxyl strong acid function, organic phosphonic acids, organic carboxylic acids having a pK.sub.

Abstract: The present invention relates to absorbents for aqueous acids or lyes comprising cross-linked, polycationic homopolymers and topolymers of quaternized, monoethylenically unsaturated carboxylic acid amino esters and/or carboxylic acid amides of the formula?CH.sub.2 =C(--R.sub.1)--CO--X--(CH.sub.2).sub.n --C(--R.sub.2, --R.sub.3)--CH.sub.2 --N(--R.sub.4,--R.sub.5,--R.sub.6)!.sup..sym. Y,(A),whereinR.sub.1 represents hydrogen or the methyl group,R.sub.2 and R.sub.3 represent hydrogen or the same or different alkyl groups having 1 to 4 C-atoms,R.sub.4, R.sub.5 and R.sub.6 represent the same or different alkyl groups having 1 to 4 C-atoms,n stands for 0 or 1,X stands for --O-- or --NH--, andY represents an anionic acid residue.

Abstract: An at least two-step process for the preparation of polyamide resins wherein, in the first step, polyvalent carboxylic acids, optionally together with monovalent carboxylic acids, are reacted with a stoichiometric deficiency of polyamines in the presence of an organic solvent which forms an azeotrope with water, water is distilled off, and the reaction is controlled by means of the amount of water formed by the condensation reaction and, optionally, by the imidazoline formation. After removal of the theoretical amount of water or a lesser amount, in a further step more amine is added to the reaction mixture in an amount sufficient to achieve a final amine number of 10 to 300 mgKOH/g, the reaction is continued, substantially all of the residual water is removed, and the residual solvent is completely or partially removed.

Abstract: A process for polymerizing oxiranes, oxetanes, oxepanes, dioxolanes, trioxanes, and tetrahydrofurans to their respective polymers by contacting them with a selected metal compound is disclosed; and also a process for depolymerizing polytetrahydrofurans to monomeric tetrahydrofurans by contacting the polymer with a selected metal compound at a temperature of about 100.degree. C. to about 250.degree. C. The catalysts may be in solution of part of a heterogeneous solid, and selected organic compounds are used as accelerators in the polymerizations. The polymeric products, some of which are novel, may be used as polyether monomers for further polymerization, as by reaction with isocyanates to produce polyurethanes, and other useful polymers. Some of the polymeric products are relatively high in molecular weight and are suitable for direct use, for instance as spandex fibers.

Abstract: A thermosetting resin composition which comprises (A) a resin in which at least one compound having a graft-reactive group such as a carboxyl group, a primary amino group or a secondary amino group and a carboxylic anhydride group has been grafted on a polycarbodiimide and (B) an epoxy compound. The said thermosetting resin composition retains heat resistance, electrically insulating properties and mechanical properties characteristic of polycarbodiimide, is excellent in solubility in various solvents and storage stability in the form of a solution and can be easily cured under mild conditions, and can produce a cured product excellent in humidity resistance, transparency, chemical stability and adhesiveness to various substrates.

Abstract: Aromatic polyamide compositions with improved electrostatic properties, formed structures produced therefrom, and use and production thereof.Described are compositions comprising an aromatic polyamide which is soluble in organic solvents and from 0.01 to 30% by weight, based on the weight of the composition, of an organic or organometallic charge control agent.The compositions can be used for producing formed structures, in particular fibers; these fibers are preferably used for producing webs which can be used for producing dust filters.

Abstract: Novel polyanhydroaspartic acids (containing not more than 3% of NH groups of the imide moieties thereof relative to the total amount of CH moieties of the succinimide moieties thereof) and the at least 90%.+-.5% biodegradable hydrolysates thereof (containing not more than 3% of primary amide groups relative to the secondary amide groups of the aspartic moieties thereof) are well suited as detergent (co)builders, the former being prepared by thermally polymerizing aspartic acid in the presence of an effective amount of at least one boron compound having at least one B-OH group, or precursor thereof, and the latter by hydrolyzing the polyanhydroaspartic acid thus obtained.

Abstract: A photoimageable polyimide coating which can be prepared from the polymeric condensation product of 6FDA, DMDE or MEDA, and a photosensitizing moiety. More particularly, the present invention relates to a photoimageable polyimide coating useful for microelectronic applications.

Abstract: Polyanils of the general formula ##STR1## where R.sup.1 is C.sub.1 -C.sub.24 -alkyl, C.sub.1 -C.sub.24 -alkoxy, Cl, Br, CF.sub.3 or NO.sub.2,R.sup.2 is para-phenylene, a fused aromatic ring system of 10 to 30 carbon atoms or ##STR2## R.sup.3 is a chemical bond, S, O, NH, CH.sub.2, CH.dbd.CH, CO, SO or SS andn is an integer from 5 to 100,and their acid addition salts of the general formula II ##STR3## where X.sup.- is ClO.sub.4.sup.-, BF.sub.4.sup.-, AsF.sub.6.sup.- or ##STR4## and R.sub.4 is C.sub.1 --C.sub.8 -alkyl are disclosed. The polyanils are useful as electrically conductive materials and for nonlinear optical purposes.

Abstract: A new class of thermotropic liquid crystalline polymers comprises monomers units I, II, III, and IV, where ##STR1## Ar.sup.1, Ar.sup.2 and Ar.sup.3 are each independently selected from the group consisting of 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 2,7-naphthylene, 4,4'-biphenylene, bis-aryl moieties having the formula ##STR2## and mixtures thereof. In the bis-aryl moieties, each X can be S, O, CO, SO, SO.sub.2, C(CH.sub.3).sub.2 or C(CF.sub.3).sub.2.

Abstract: A photoimageable polyimide coating which can be prepared from the polymeric condensation product of 6FDA, DMDE or MEDA, and a photosensitizing moiety. More particularly, the present invention relates to a photoimageable polyimide coating useful for microelectronic applications.

Abstract: A method of preparing a lass of PPV derivatives includes preparing a soluble precursor of a PPV derivative and converting the soluble precursor to a PPV derivative. The converting includes performing either a thermal treatment in a range of temperatures from approximately 25.degree. C. to 400.degree. C. at a reduced pressure or an acid-catalyzed ultraviolet radiation treatment.

Abstract: In a method for ring opening polymerization in which the polymerization proceeds with the ring opening of a cyclic compound as a monomer, a hydrolase is used as a catalyst.

Abstract: A novel aromatic diamino amide monomer of the structural formula (I), a novel aromatic polyamide of the structural formula (II) prepared by polycondensation of the monomer and an aromatic diacid halide, and an aromatic polyamide film produced from the polyamide which has high strength as well as high modulusity. ##STR1## wherein, each of two NH.sub.2 groups may be in meta or para-position to the amide bond. ##STR2## wherein, Ar represents a phenyl group, X represents CONH.sub.2 group in ortho-position to the amide bond, Y represents H, Cl, Br, I, NO.sub.2 or an alkyl or alkoxy group having 1 to 4 carbon atom, and n represents an integer between 10 and 100,000.

Abstract: A crosslinked poly(ethylene or propylene)glycol-containing polymer which has a unique spatial structure and can be designed especially for application as a chromatographic resin or as a solid support for the synthesis of peptides, oligonucleotides or oligosaccharides or as a substrate for the immobilization of proteins. The polymer is formed by radical copolymerization of derivatized poly(ethylene or propylene) glycol bis-end substituted with a moiety selected from the group consisting of acryloylalkyl, acryloylaryl, acrylamidoalkyl and acrylamidoaryl with an acrylic amide, nitrile or ester. When it is to be used as a solid support or immobilization substrate, the polymer will incorporate a spacer comprising functional groups for the attachment of peptides, proteins, nucleotides or saccharides such as those selected from the group consisting of amino, alkylamino, hydroxy, carboxyl, mercapto, sulfeno, sulfino, sulfo and derivatives thereof.

Abstract: Described are carboxyl-terminated polyetheramides of the formula: ##STR1## where R is a moiety from an alcohol or hydroxy compound having a valence of k; R' is independently hydrogen or lower alkyl from 1 to 4 carbon atoms; R" is independently a straight or branched alkylene or aromatic moiety averaging from about 2 to 36 carbon atoms; x averages from about 2 to 100; z averages from about 20 to about 250; k averages from about 1 to 3; m is 0 or 1; and p is independently 5 to 11. Because the carboxyl-terminated polyetheramides are all carboxyl-terminated, they do not gel. They are expected to have good impact strength as well as differing solubilities depending on the polyetheramine incorporated.

Abstract: Novel cyclic imino ether compositions containing one or more mesogenic moieties, when polymerized, result in products having improved properties.

Abstract: Poly(arylene ether)ketones, polyamides, and poly(benzoxazoles) that contain thiophene rings within the aromatic polymer backbone are disclosed, along with fibers, films, and other articles of manufacture formed therefrom.

Abstract: A process for forming an ultra-high molecular weight nylon 6 by polymerizing .epsilon.-caprolactam, which comprises heating substantially anhydrous .epsilon.-caprolactam at a temperature of from 100.degree. to 200.degree. C. in the presence of (a) a main catalyst selected from a Grignard compound and a halogenated magnesium lactamate, (b) a co-catalyst selected from an acyl lactam compound and an isocyanic acid ester and (c) at least one activator selected from the group consisting of amides, sulfoxides, thioethers and phosphoric esters. According to this inventive process, an ultra-high molecular weight nylon 6 can be produced within a short period of time, making use of industrially advantageous compounds which are stable in air, hardly dangerous and inexpensive. Being free from cross-linkings, the ultra-high molecular weight nylon 6 obtained by the process of this invention is soluble in various solvents and is useful as a starting material for the production of high strength and high modulus materials.

Abstract: A method for preparing poly(imide-amide)s comprising reacting carbon monoxide, an aromatic or heteroaromatic diamine, and an aromatic or heteroaromatic di(trifluoromethane sulfonate), in the presence of solvent and a catalyst One of the aromatic reactants has a nucleus including a phthalimide ring system. The catalyst is a compound of a metal selected from the group consisting of platinum, palladium and nickel.

Abstract: Lactam-lactone copolymers are provided that range in properties from plastic to elastomer which are formed by reacting components of a polymerizable composition comprising: a lactam monomer; a lactone monomer; a C.sub.3 to C.sub.12 lactam magnesium halide catalyst; and an initiator.

Abstract: The thermoplastic molding compositions contain as essential componentsA) from 96 to 99.9% by weight of at least one polyamide,B) from 0.1 to 4% by weight of one or more dialkyl ketones of the general formula I ##STR1## where R and R' are each alkyl of from 10 to 30 carbon atoms, and also, based on the sum total of A) and B),C) from 0 to 40% by weight of an impact modifying rubber,D) from 0 to 60% by weight of fibrous or particulate fillers or a mixture thereof, andE) from 0 to 120% by weight of a modified polyphenylene ether.

Abstract: The present invention relates to water-dispersible polyetherester-modified polyurethane ionomers containing 10 to 100 milliequivalents of ionic, preferably cationic, groups per 100 g of ionomer; 2 to 40% by weight of polyetherester groups; and 1 to 35% by weight of ethylene oxide units, in which the percentages are based on the weight of the polyetherester-modified polyurethane ionomer.The present invention also relates to a process for the preparation of these polyetherester-modified polyurethane ionomers and to aqueous compositions containing these polyetherester-modified polyurethane ionomers and polymers containing perfluoralkyl groups.

Abstract: Fusible polyimide powders are prepared by the process of this invention. An amic acid amine is first prepared by treating (n+1) moles of a bis(aminophenyl)methane with n mole of aromatic tetracarboxylic anhdride to produce an aromatic amic acid prepolymer. This prepolymer is then mixed with an unsaturated carbocyclic monoanhydride and the mixture heated to form a reactive end-capped polyamic acid precursor. The resulting composition is thermally treated in order to partially imidize the precursor. The resulting fusible polyimide powder is finally separated.

Abstract: Compounds of the formula ##STR1## in which, independently of one another, each R is OH or lower alkyl having 1-4 carbon atoms and each R' is hydrogen or lower alkyl having 1-4 carbon atoms, are prepared by the condensation of partially fluorinated aromatic hydrocarbons in the presence of hydrogen fluoride or by the reductive coupling of partially fluorinated aromatic compounds. The compounds are used as a starting material for the preparation of partially fluorinated polycondensates.

Abstract: New wholly aromatic polyamides are provided. This polymers are prepared by a mixture of N,N'-bis(4-aminophenyl)-isophthalamide and p-phenylenediamine in a tertiary amide solvent containing an alkali metal salt such as LiCl and a tertiary amine as an acid acceptor. The polymers are easily dry-jet spun to form a fiber and cast to form a film. The fiber and film so obtained have ultrahigh tenacity, elasticity and elongation.

Abstract: A denatured bismaleimide resin of repeating units represented by the following formula (I) and process for preparing same which comprises the Michael addition reaction of a bismaleimide and an aromatic secondary diamine: ##STR1## wherein, n represents an integer of 1 to 3, A represents a divalent group having from 2 to 20 carbon atoms,A' represents a divalent group having less than 20 carbon atoms which includes at least one or more aromatic groups, andR represents aliphatic having from 1 to 10 carbon atoms.

Abstract: The present invention is connected with a process for preparing a novel photosensitive polyimide precursor having excellent shelf stability and high sensitivity and containing less impurities.The process for preparing a photosensitive heat-resistant polymer containing a repeating unit represented by the formula (III) comprises the step of reacting a photosensitive group-containing isoimide represented by the formula (I) with a diamine represented by the formula (II) at a temperature of 0.degree. to 100.degree. C. in the presence of a solvent: ##STR1## wherein R.sup.1 is independently a tetravalent carbon cyclic aromatic group or heterocyclic group; R.sup.2 is independently an aliphatic group having at least 2 carbon atoms, an alicyclic group, an aromatic aliphatic group, a carbon cyclic aromatic group, a heterocyclic group or a polysiloxane group; R.sup.3 is a monovalent organic group having a photosensitive unsaturated group; and D is an oxygen atom or .dbd.N--R.sup.3.

Abstract: The invention relates to a process for the solid phase post-condensation of (co)polyamides which contain small amounts of lysine components and about equivalent amounts thereto of a polycarboxylic acid incorporated. Thermoplastically deformable, slightly branched aliphatic (co)polyamides having increased melt viscosity and pronounced pseudoplasticity are obtained in a shortened reaction time. The invention also relates to solid phase post-condensed (co)polyamides of this type.

Abstract: A process for the continuous and discontinuous production of polycaprolactam is disclosed which includes the step of polymerizing, by anionic polymerization, .epsilon.-caprolactam to which suitable initiators and activators are added. The process may optionally include the addition of comonomers, pigments, electroconductive fillers, modifying polymers, inorganic fillers, reinforcing fibers, inorganic fillers and/or other additives to a dispersing media in which the polymerization takes place with polycaprolctam, copolymers or composites thereof being obtained in the form of particles. The foregoing additives may, for example, be added to the dispersing media dropwise with mechanical or convective stirring under controlled temperature conditions.

Abstract: This invention relates to thermoplastically mouldable slightly branched aliphatic (co)polyamides of high molecular weight with increased melt viscosities and a marked structural viscosity prepared by accelerated polycondensation of suitable monomer melts in the presence of small quantities of lysine components and approximately equivalent quantities of a polycarboxylic acid optionally followed by a thermal after-condensation reaction, and to a process for the polycondensation. The lysine components used are lysine, lysine hydrate, esters of lysine with low alcohols or lysine hydrochlorides (the latter in the presence of approximately equivalent quantities of bases added at the same time to bind the HCl).

Abstract: The invention relates to high molecular weight (co)polyamides and to a process for the accelerated production of polyamides during melt polycondensation using a combination of aminocaprolactam (ACL) and/or lysine components and polycarboxylic acids and known catalysts and also, if desired, for the accelerated solid-phase post-condensation of the catalyst-containing (co)polyamides and to the polyamides produced by the processes.

Abstract: A molecular weight controller having particular application in the polymerization of a lactam, i.e., epsiloncaprolactam, to a polyamide, i.e., poly(epsiloncaprolactam). The molecular weight controller comprises a primary monofunctional amine, i.e., benzylamine, a primary monofunctional acid, i.e., acetic acid, and a salified aminoacid containing an aromatic, a cyclohexane, or cyclopentane moiety, i.e., 4-(aminomethyl)benzoic acid salified with p-toluenesulfonic acid. The resulting polyamide has a reduced water extractable content.

Abstract: Imide prepolymer compositions containing an unsaturated component (A) and diamine component (B) at the (A)/(B) molar ratio of 0.9-1.5 and 0.01-5.0% by weight, based on the sum of said components (A) and (B), of at least one radical polymerization inhibitors, and preferably further 0.01-5.0% by weight, based on the sum of said components (A) and (B), of at least one compound selected from the group of carboxylic acid and carboxylic acid anhydride.The imide prepolymer compositions of the present invention which contain the above-defined components in specific proportions are tough and excellent in adhesive strength to glass cloths and metals and in heat resistance.

Abstract: Aromatic copolyamides, soluble in organic polyamide solvents, comprise at least 95 mol % of the recurrent structural units of the formulae ##STR1## and up to 5 mol % of structural units containing m-bonds. Here, --Ar--and --Ar'-- are divalent, unsubstituted or substituted aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position, and --R is a lower alkyl radical.

Abstract: Aromatic copolyamides, soluble in organic polyamide solvents, comprise at least 95 mol % of the recurrent structural units of the formulae ##STR1## and up to 5 mol % of structural units containing m-bonds. Here --Ar--is a divalent, unsubstituted or substituted aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position, and --R--and --R' are different from one another and are lower alkyl radicals or lower alkoxy radicals.

Abstract: A membrane filter material formed from a solvent resistant bismaleimide polymer which is formed by polymerizing a bismaleimide compound with a perhydrodiaza-type heterocyclic compound and has a main structural skeleton represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents a lower carbon chain which is linear or contains a methyl group or ethyl group on the side chain, R.sub.5 represents a divalent group containing an aromatic ring, Y is >R< or >N--R--N< in which R is a lower carbon chain, and m is 0 or 1.This bismaleimide polymer can be a membrane filter material having an excellent organic solvent resistance. When this polymer is formed into a hollow fiber or plain film, a high separating and filtering capacity and an excellent organic resistance can be attained.