Abstract: The present invention relates to polymaleimide compounds having the following chemical structure: ##STR1## wherein n represents an integer of from 0 to about 50 and to a process for preparing the same.

Abstract: This invention relates to thermoplastically deformable branched aliphatic polyamides prepared by the hydrolytic polycondensation of lactams in the presence of small quantities of .alpha.-amino-.epsilon.-caprolactam (ACL) and approximately equivalent quantities of polycarboxylic acids (preferably dicarboxylic acids) and to a process for their preparation which is distinguished by considerably reduced polycondensation times without giving rise to cross-linked products. The process optionally in addition employs a solid phase after-condensation in which rapid further condensation takes place to the products with increased melt viscosity which are branched but are still soluble in m-cresol.

Abstract: Polyamides are prepared from a carbonitrile and an amine by reacting by heating a mixture of a carbonitrile which is a dinitrile, an equivalent amount of a primary or secondary amine which is a diamine, and at least a stoichiometric amount of water in the presence of an effective amount of a catalyst. The catalyst is a complex containing at least one metal selected from the group consisting of ruthenium, rhodium and molybdenum, and at least one group selected from the group consisting of hydride, phosphine, carbonyl, ammonia, and hydroxyl.

Abstract: Process of preparing modified polyamides endowed with improved mechanical properties, which process resides in polymerizing an .omega.-lactam in the presence of(a) a polyisocyanate having the isocyanate groups blocked by an .omega.-lactam,(b) a poly-oxy-alkylene-amine, and(c) an alkali metal catalyst.A further object of the invention is the products obtained by means of such a process.

Abstract: Disclosed herein is a process for producing a polyamide comprising polymerizing at least one monomer of polyamide in the presence of(1) a hydrocarbon polymer having at least one group selected from the group consisting of a carboxyl group, a derivative group of carboxylic acid, an amino group, and a hydroxyl group, or(2) a polymer produced by reacting the hydrocarbon polymer with a polyamide, or polymerizing at least one monomer of polyamide in the presence of the hydrocarbon polymer.

Abstract: A method for synthetizing polyanhydrides in solution using coupling agents and a removable acid acceptor to effect a one-step polymerization of dicarboxylic acids. As used in the method, these coupling agents include phosgene, diphosgene, and acid chlorides. Insoluble acid acceptors include insoluble polyamines and crosslinked polyamines such as polyethyleneimine and polyvinylpyridine and inorganic bases such as K.sub.2 CO.sub.3, Na.sub.2 CO.sub.3, NaHCO.sub.3, and CaCO.sub.3. The only byproduct formed is a removable hydrochloric acid-acid acceptor.Examples are provided of the polymerization of highly pure polyanhydrides using phosgene, diphosgene or an acid chloride as the coupling agent, in combination with either an insoluble acid acceptor or a soluble acid acceptor in a solvent wherein the polymerizaiton byproduct or polymer is insoluble.A particularly important application of these polyanhydrides is in the formation of drug delivery devices containing bioactive compounds.

Abstract: This invention relates to thermoplastically deformable, high molecular weight, slightly branched aliphatic polyamides prepared by the polycondensation of polyamide-forming, aliphatic diamine/dicarboxylic acid mixtures, optionally with the addition of lactams and special amino acids, in the presence of small quantities of .alpha.-amino-.epsilon.-caprolactam, and optionally their thermal solid phase after-condensation.

Abstract: A new class of polymers and processes used in their preparation are described. These polymers are comprised of crosslinkable aramids, especially aramids that are based on synthetic aromatic amino acids. The aromatic amino acids suggested for this application are selected from the classes of amino benzoic acids, aminodiphenyl carboxylic acids, aminodiphenyl ether carboxylic acids, aminodiphenyl sulfide carboxylic acids, amino diphenyl sulfoxide--and sulfone carboxylic acids, aminonaphtalene carboxylic acids, amino anthracene carboxylic acids as well as their sulfonic acid counterparts, aminopyrimidine carboxylic acids and their crosslinkable and potentially crosslinkable derivatives. Crosslinkable or potentially crosslinkable moieties are selected from a group comprising amino-, nitro-, cyano-, halogene, acetylene, vinyl, acrylic moieties. Crosslinking can be achieved after linear polymers of high molecular weight are produced from low molecular weight prepolymers.

Abstract: Catalyst composition solid at room temperature, based on alkali metal lactamate, characterized in that the content of methanol, ethanol and n-propanol is lower than 0,2 wt. % and that 0.1-5 wt. % of another alcohol is present, chosen from isopropanol or a branched or unbranched aliphatic or aromatic alcohol with 4-18 carbon atoms, which alcohol has a boiling point of 80.degree. C. to 250.degree. C.This catalyst composition is suitable for lactam polymerization, especially in RIM techniques. Nylon block copolymer prepared with said catalyst composition and articles made frrom this nylon block copolymer.

Abstract: A method for producing a polyether-polyamide block copolymer is disclosed, comprising copolymerizing, in the presence of an anionic polymerization catalyst, a lactam and a polyether prepolymer presented by the formula: ##STR1## wherein R.sup.1 is an aliphatic hydrocarbon residual group having 2 to 6 carbon atoms, R.sup.2 is an aliphatic hydrocarbon residual group having 3 to 12 carbon atoms, and n is an integer of 4 to 450. The polyester prepolymer is prepared by reacting a polyoxyalkylene having two terminal hydroxy groups with an N-chlorocarbonyl lactam. The polyether-polyamide block according to the invention has high impact strength and is substantially colorless.

Abstract: Novel, heat-stable imido polymers, well adopted, e.g., as coating or molding resins, comprise the polymerizates of (a) at least one N,N'-bismaleimide, (b) at least one diprimary diamine, and (c) at least one N-(meth)-allyloxyphenylmaleimide.

Abstract: An improved composite polyamide membrane and methods of making the membrane are described. This improved membrane is prepared using a cationic polymeric wetting agent in an aqueous solution containing a polyfunctional amine reactant which is interfacially polymerized with an acyl halide to form a thin film polyamide discriminating layer on a microporous support. Alternatively, the wetting agent can be applied directly to the substrate and the interfacial polymerization can occur on said treated substrate. The resulting membrane exhibits an unexpected combination of high water flux, high rejection of divalent anion salts, variable sodium chloride rejection and good caustic resistance at low operating pressures. In one embodiment of this invention, a porous substrate is first treated with an aqueous piperazine solution containing a copolymer of vinylbenzyl dimethyl sulfonium chloride and methacrylic acid and then the coated microporous support is contacted with trimesoyl chloride in an organic solvent.

Abstract: A novel star block copolymer represented by the general formula as shown below and a process for the production thereof are described. The copolymer has superior physical properties, particularly impact strength and, furthermore, is reduced in coloration. Thus the copolymer can find numerous uses; for example, it can be used in preparation of fibers, foams, automotive parts, and electrical components. The copolymer is produced by copolymerizing a star-shaped polyether prepolymer and a lactam, said prepolymer being prepared by reacting a star-shaped polyoxyalkylene having at least 3 terminal hydroxy groups and an N-chlorocarbonyl lactam, in the presence of an anionic polymerization catalyst. ##STR1## In this formula, all the symbols are as defined hereinbefore.

Abstract: The process for manufacturing a nylon-type polyamide from a dinitrile, a diamine and water in the presence of a catalyst is improved by using as a catalyst an ester of oxygenated phosphorus compound in conjunction with a strong base. For example, high quality nylon-6,6 is manufactured by contacting adiponitrile, hexamethylene diamine and water with an ester of an oxygenated phosphorous compound and sodium hydroxide at an elevated temperature and pressure.

Abstract: Nylon-type polyamides are produced from a diamine and a diamide in contact with a catalyst comprising a carboxamide. For example, high quality nylon-6,6 is manufactured by contacting hexamethylenediamine and adipamide in water with a carboxamide, at an elevated temperature and pressure.

Abstract: The invention relates to polyimides of the general formula ##STR1## wherein R.sub.1, R.sub.2 =H, C.sub.1-3 -alkyl, halogen,R.sub.3 =C.sub.2-12 -alkylene or ##STR2## m=0, 1, X=CH.sub.2, C(CH.sub.3).sub.2, CO, O, S, SO.sub.

Abstract: This invention relates to the use of compositions of the formula: ##STR1## wherein n is 2 to 4 and X is --O--, --S-- or ##STR2## wherein R.sub.1 is an aliphatic or aromatic moiety as a curing agent for epoxy resins to form a thermoset material which has a reduced shrinkage.

Abstract: The invention relates to a process for the production of polybenzamides from amino benzoic acids in the presence of metal halides.

Abstract: A process for the manufacture of a polyamide powder comprising polymerizing in solution a reaction mixture comprising a monomer lactam or lactams capable of generating said polyamide in the presence of an N,N'-alkylene bisamide.

Abstract: A process for producing a lactam copolymer, which comprises copolymerizing an omega-lactam and a diene polymer having an amino or imino group at molecular ends by the action of an alkaline catalyst and a polyfunctional co-catalyst, the proportions of the components satisfying the following equations (I) and (II)a/c>1/4 (I)b/c>1 (II)wherein a, b and c represent the equivalent weights of the alkaline catalyst, the polyfunctional co-catalyst and the diene polymer, respectively, per equivalent of omega-lactam.

Abstract: Thermosettable prepolymers are prepared by reacting (1) an aromatic heterocyclic material having one or more rings and at least one nitrogen atom and at least two reactive substituent groups which have at least one reactive hydrogen atom attached to a carbon atom which is attached to a heterocyclic ring such as 2,3,5,6-tetramethylpyrazine or 2,4,6-trimethylpyridine, (2) a cycloaliphatic or aromatic carboxylic acid cyclic mono- or dianhydride such as pyromellitic dianhydride and (3) a material containing a polymerizable ethylenically unsaturated group and at least one group selected from (a) a heterocyclic material having one or more rings and at least one nitrogen atom and at least one substituent group which has at least one reactive hydrogen atom attached to a carbon atom which is attached to a heterocyclic ring such as 2-methyl-5-vinylpyridine, and (b) a cycloaliphatic or aromatic carboxylic acid cyclic monoanhydride or dianhydride such as cis-5-norbornene-endo-2,3-dicarboxylic anhydride.

Abstract: Methods of making modified polyimide adhesives and laminating compositions. These adhesives are also particularly useful as the matrix material in high strength fiber reinforced composites. The adhesive compositions are prepared by initially reacting an oxoimine with one or more tetracarboxylic acid dianhydrides, which is primarily 1, 2, 3, 4-butanetetracarboxylic acid dianhydride. The resulting bisimide is dissolved in a non-reactive solvent and a suitable diamine is added to react with the bisimide, producing a liquid resin solution which is essentially a polyamide resin solution. This solution is useful as an adhesive or a fiber composite matrix which can be cured to a polyimide at moderate processing temperatures. The final adhesive bond or matrix is found to be flexible, strong and very resistant to flame, high temperatures, oils and solvents.

Abstract: A novel star block copolymer represented by the general formula as shown below and a process for the production thereof are described. The copolymer has superior physical properties, particularly impact strength and, furthermore, is reduced in coloration. Thus the copolymer can find numerous uses; for example, it can be used in preparation of fibers, foams, automotive parts, and electrical components. The copolymer is produced by copolymerizing a star-shaped polyether prepolymer and a lactam, said prepolymer being prepared by reacting a star-shaped polyoxyalkylene having at least 3 terminal hydroxy groups and an N-chlorocarbonyl lactam, in the presence of an anionic polymerization catalyst. ##STR1## In this formula, all the symbols are as defined hereinbefore.

Abstract: The invention concerns a simple process for preparing an ester acyllactam and/or esteramide acyllactam by the catalytic condensation of imide and alcohol, characterized in that a polyol and an acyllactam compound are reacted in the liquid state in the presencce of a halide, carboxylate or acetylacetonate from beryllium, magnesium, calcium, strontium, barium, boron, aluminium, zinc or cadmium.The invention is important for the preparation of compounds which may be used in the preparation of nylon block copolymers, more in particular in RIM-nylon systems (Reaction Injection Moulding), since when the compounds obtained according to the present invention are used in a RIM system, a very fast lactam polymerization takes place, and it therefore also relates to the preparation of nylon block copolymers.

Abstract: Process for preparing polyamide by anionically polymerizing lactam in the presence of an alkaline metal catalyst, an activator and at least one low molecular weight ester compound. The polymerization process is rapid and yields polyamides having good impact strengths. The process significantly reduces moulding time in reaction injection moulding.

Abstract: The invention relates to a process for the preparation of a nylon block copolymer composition by polymerization of lactam in the presence of a lactam-polymerization catalyst and an activator, characterized in that the activator used is a combination of:1. a high molecular weight lactam-terminated activator with a molecular weight of at least 1500, and2. a low molecular weight lactam-terminated activator with a molecular weight of at most 750.The process according to the invention can, in particular, be used in a reaction injection moulding process, in which liquid reaction component are introduced into a mould where fast polymerization to a moulded object takes place.

Abstract: The process for manufacturing a nylon-type polyamide from a dinitrile, a diamine and water in the presence of a catalyst is improved by using as a catalyst an oxygenated phosphorus compound and an oxygenated boron compound. For example, high quality nylon-6,6 is manufactured by contacting adiponitrile, hexamethylene diamine and water with boric acid and phosphorous acid at an elevated temperature and pressure.

Abstract: An improved method of molding involves utilizing as the catalyst and initiator components of a polymerizable composition, a Grignard catalyst and a dual initiator system.

Abstract: A process for polymerizing .epsilon.-caprolactam to form a nylon-6 block copolymer in which a reactant stream containing .epsilon.-caprolactam, and a lactam polymerization initiator is brought into polymerizing admixture with a reactant stream containing .epsilon.-caprolactam and a lactam magnesium halide, wherein sufficient 2-oxo-1-pyrrolidinyl compound is added to the admixture either as 2-pyrrolidinone, 2-oxo-pyrrolidinyl magnesium halide or 2-oxo-1-pyrrolidinyl capped initiator compound to enhance the rate of polymerization of the .epsilon.-caprolactam. The lactam polymerization initiator is a telechelic oligomer or polymer containing a backbone which provides elastomeric segments in the nylon-6 block copolymer, and attached to the backbone are activated initiator groups which initiate the polymerization of .epsilon.-caprolactam in the presence of the lactam magnesium halide.

Abstract: Compositions for the preparation of block copolylactams comprising lactam, lactam polymerization initiator and an effective amount of a viscosity enhancing compound selected from the group consisting of the lactamates and .omega.-amino acid salts of barium, calcium and strontium.

Abstract: A process for polymerizing .epsilon.-caprolactam to form a nylon-6 polymer in which a reactant stream containing .epsilon.-caprolactam and a lactam polymerization initiator is brought into polymerizing admixture with a reactant stream containing .epsilon.-caprolactam and a lactam magnesium halide, wherein sufficient 2-oxo-1-pyrrolidinyl compound is added to the admixture either as 2-pyrrolidinone, 2-oxo-pyrrolidinyl magnesium halide or 2-oxo-1-pyrrolidinyl capped initiator compound to enhance the rate of polymerization of the .epsilon.-caprolactam.

Abstract: A process for modifying certain polyamides by use of a novel combination of an organic sulfone and a lithium halide as a processing aid to yield a modified polymer having thermal stability and a lowered melting point (lower than unmodified polymer).

Abstract: A mixture consisting of a polymaleimide and a copolymerizable monomer or a prepolymer formed from these two compounds contains, as the polymerization catalyst, an ethane which is substituted by aromatic groups and hydroxyl groups or halogen (cf. formula II), such as benzpinacol. The mixture is stable on storage and heat-curable. It can be cured, while at the same time being shaped to give mouldings, sheet-like structures, laminates, adhesive bonds or foams, for example by casting or compression moulding.

Abstract: High molecular weight block copolyamides useful in the production of fibers of high strength and modulus, having the following formula: ##STR1## wherein X is --CH.sub.2 --.sub.m, wherein m is 0 to 12, ##STR2## wherein Z is C(CH.sub.3).sub.2, zero, oxygen or SO.sub.2, are prepared from N,N'-bis(4-aminophenyl) terephthalamide having the formula: ##STR3## which is itself prepared by condensing aniline with dimethyl terephthalate or terephthalic acid, nitrating the product produced thereby and finally hydrogenating the resultant compound.

Abstract: A block copolyamide having effectively improved impact strength is obtained by polymerizing a mixture comprising substantially from about 50 to about 95 parts by weight of lactam and from about 50 to about 5 parts by weight of polyol in the presence of catalyst for an anionic polymerization and activator represented by the following formula (I); ##STR1## wherein A denotes a bifunctional organic residue having at least one kind of heteroatoms selected from the group consisting of N, O, S, F, Cl, Br and I, and Y and Y' denote an acyl group selected from the group consisting of ##STR2## respectively, and n and n' denote an integer of 3 to 11 respectively, or by polymerizing, in the presence of catalyst for anionic polymerization, a mixture comprising substantially from about 50 to about 95 parts by weight of lactam and from about 5 to about 50 parts by weight of prepolymer obtained by a reaction of polyol and activator represented by the above formula (I), wherein A denotes a bifunctional aromatic residue having

Abstract: Polyamides such as nylon-6 type polyamides are prepared by the reaction or copolymerization of a major amount by weight of a lactam and a minor amount by weight of a graft copolymer of maleic anhydride on a low molecular weight liquid conjugated diene polymer or copolymer or of a copolymer of a conjugated diene and a monovinyl aryl monomer or a nitrile. For example, a graft of maleic anhydride on liquid butadiene/acrylonitrile copolymer is copolymerized with epsilon-caprolactam using an anionic lactam polymerization catalyst (a lactamate salt) like the reaction product of ethyl magnesium bromide and epsilon-caprolactam. The present invention may be useful in a RIM (Reaction Injection Molding) process. The resulting polyamides have improved impact strength and water resistance. They can be used to make automobile and truck bodies and parts.

Abstract: An improved process for the preparation of fiber-forming polycaprolactam by polymerizing .epsilon.-caprolactam, and an aqueous extract containing .epsilon.-caprolactam and caprolactam oligomers, which extract has been obtained by extracting polycaprolactam with water, wherein the aqueous extract contains from 0.1 to 5.0% by weight of oligomers of caprolactam, based on the monomeric caprolactam in the aqueous extract.

Abstract: Novel amorphous copolyamides are provided which are the product of reaction of (A) a lactam, (B) a bisimidazoline, and (C) a dicarboxylic acid, wherein the proportions of reactants based on 100 mole percent are from about 43 to about 82 mole percent of lactam (A) and the remaining 18 to 57 mole percent divided between said (B) and said (C) in substantially equimolar proportions.The copolyamides are characterized by better resistance to elevated temperatures than 100 percent polycaprolactam polyamides but at the same time are easily molded because of their amorphous character.

Abstract: Molded articles of polymerized lactams are prepared by pumping of a catalyst containing partial lactam melt at a temperature of .+-.1.degree. C. of a temperature in the range of 160.degree. C. to 170.degree. C. and a lower temperature activator containing partial lactam melt at a temperature of .+-.1.degree. C. of a temperature in the range of 160.degree. C. to 170.degree. C. to which activator addition is delayed relative to catalyst addition, with separate gear pumps to a mixing zone maintained between 170.degree. and 175.degree. C., the pumps connected to the mixing zone by straight feed tubes positioned at an angle of inclination to the horizontal of a maximum of 10.degree., each feed tube having a volume of at least one-third greater than the pump to which it is connected and form the mixing zone into a mold. At least part of the gases released are returned to the mixing zone by the tube systems and gear pumps. The products formed crumble on being heated to a temperature of approximately 220.degree. C.

Abstract: Molded articles of polymerized lactams are prepared by pumping of a catalyst containing partial lactam melt at a temperature of .+-.1.degree. C. of a temperature in the range of 160.degree. C. to 170.degree. C. and a lower temperature activator containing partial lactam melt at a temperature of .+-.1.degree. C. of a temperature in the range of 160.degree. C. to 170.degree. C. to which activator addition is delayed relative to catalyst addition, with separate gear pumps to a mixing zone maintained between 170.degree. and 175.degree. C., the pumps connected to the mixing zone by straight feed tubes positioned at an angle of inclination to the horizontal of a maximum of 10.degree., each feed tube having a volume of at least one-third greater than the pump to which it is connected and form the mixing zone into a mold. At least part of the gases released are returned to the mixing zone by the tube systems and gear pumps. Apparatus to carry out the method is also provided.

Abstract: Poly(.epsilon.-caprolactam) is prepared with less than 3 percent water-extractable material by carrying out the polymerization reaction in a vessel, the interior surfaces of which are coated with an inert adherent coating of an organic polymer.

Abstract: Formed from trifunctional units (M) having attached, to one of the two terminal carbon atoms of an alkylene hydrocarbon diradical, the functional group A', and having attached, to the other terminal carbon atom, a different functional group B' reactive A' to form a linkage AB; and having attached, to a third carbon of the skeleton of unit (M), the functional group A" (preferably the same as A') reactive with B' whereby a macromolecule is built up of successive layers of units (M). The process involves successive stages in the first of which, the functional groups A' are blocked and group B is blocked with a "source" unit (S); then groups A' are liberated to form Compound I. In the second stage, Compound II is formed from the starting material (such as lysine) by first blocking groups A', then converting group B' to a form reactive with A'.

Abstract: Disclosed are catalysts for the polymerization of higher lactam monomers. The catalysts comprise an essentially homogenic binary mixture of lauric-lactam and a salt of lauric-lactam.The inventive catalyst can be stored at room temperature without making special provisions to avoid any access of air and moisture.

Abstract: An improved, consistent quality anionic catalyst for polymerizing pyrrolidone, optionally mixed with up to 25% of another copolymerizable lactam, is disclosed in which an alkali metal pyrrolidonate, prepared by reacting an alkali metal hydroxide or alkoxide with a molar excess of pyrrolidone, is heated for at least 5 hours at 100.degree.-175.degree. C. in the absence of water and air. Reproduceable results are obtained when the catalyst so heated is used to polymerize pyrrolidone.

Abstract: Process which accelerates the activated and non-activated polymerization of 2-pyrrolidone. A prepared polymerization charge containing monomer and components of the initiation system is first allowed to polymerize at a temperature above the monomer melting temperature, then is cooled below the melting point of the mixture, and then the crystalline reaction mixture is heated to a polymerization temperature of 25.degree. to 60.degree. C.

Abstract: An initiator for the anionic polymerization of heterocyclic monomers comprises the product from the association of an alkali metal amide and the salt from at least one hydroxylated compound with the same alkali metal in an aprotic solvent. The hydroxylated compound is a primary alcohol, a secondary or tertiary alcohol, an ether alcohol, an amino alcohol, a polyether alcohol, a polyamino alcohol, a polyaminoetheralcohol, or an enol from a ketone.

Abstract: A single-stage melt polymerization process for the production of high molecular weight polybenzimidazole is provided. The process comprises reacting a monomeric reactant or reactants, which are capable of reacting to form a polybenzimidazole, at a temperature above the melting temperature of the monomeric reactant or reactants in the presence of a catalyst selected from the group consisting of organic sulfonic acids, halogenated acetic acids, and non-oxidizing inorganic acids. The polybenzimidazole is preferably produced by the reaction of 3,3',4,4'-tetraaminobiphenyl with isophthalic acid at a temperature within the range of approximately 360.degree. C. to 425.degree. C. for a period of time within the range of approximately 3 to 5 hours in the presence of approximately 0.25 to 0.5 percent by weight, based upon the weight of the isophthalic acid, of p-toluenesulfonic acid.

Abstract: Polypyrrolidone polymers and copolymers are obtained by polymerizing 2-pyrrolidone, optionally with another lactam, in the presence of a catalyst and accelerator, first in the mass until at least 10% of the monomer is converted but the reaction product is still capable of suspension, then completing the desired degree of polymerization by suspending the reaction mixture in an inert liquid dispersion agent that does not dissolve the desired polymer. Relatively high molecular weight polymers are prepared in a short amount of time using this two-stage procedure.

Abstract: A method is described for the anionic polymerization and copolymerization of .omega.-aminoacid lactams. This end is attained at elevated temperatures in the presence of a polymerization initiator of the formulaMeZX.sub.m L.sub.nwherein Me is an alkali metal, Z is boron or aluminum, X is an alkoxy group and L is an organic residue derived from a lactam and being of the formula ##STR1## wherein a is an integer in the range 3-11, m is an integer in the range of 0-3, (m+n) is 4 and n is (4-m).

Abstract: Novel imide resins are prepared by reacting a mixture of a bisimide of an unsaturated dicarboxylic acid and a monoimide with a dihydrazide of a dicarboxylic acid, preferably in an organic solvent or diluent at elevated temperature for a period of time insufficient to yield an insoluble, infusible, fully cured imide resin. Solutions of the resulting prepolymerization product are stable at room temperature and their viscosity remains substantially unchanged for a prolonged period of time. Fully cured imide resins and articles thereof of a high heat resistance are obtained by heating said prepolymerized imide resin or materials such as fibers, metal wire webs, and others impregnated therewith, if desired, in the presence of curing catalysts, inhibitors, fillers and other materials to curing temperature up to 350.degree. C.