Abstract: The present invention provides for hybrid polybenzimidazole and polybenzimidazolone polymers which are characterized as containing both imidazole and imidazolone structural units in the polymer chain. These polymers are characterized as containing at least one recurring monomer unit containing the structure of the formula: ##STR1## wherein Ar is a tetravalent aromatic moiety derived from an aromatic tetraamine and Ar.sub.1 is a trivalent aromatic moiety derived from a trifunctional acid, an acid anhydride or amine-reactive derivatives thereof, said polymers further characterized by an inherent viscosity of at least about 0.01 dl/g measured as a 0.5% solution in N-methyl pyrrolidone at 25.degree. C.The polymers of this invention exhibit many of the advantageous properties of both polybenzimidazole and polybenzimidazolone polymers. They are characterized as being extremely resistant to chemical attack such as by solvents, acids and bases.

Abstract: Copolyimides and their precursors are disclosed comprising units represented by the formula ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and are hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl, with the proviso that R.sub.1, R.sub.2, R.sub.3 and R.sub.4 cannot simultaneously be hydrogen and where Z is a chemical bond, ##STR2## Ar is the tetravalent residue of a tetracarboxylic acid or acid dianhydride or di- or tetraester thereof, where x and y are integers from about 100 to about 1,000, and the ratio of x to y is from about 1:99 to about 49:51, and z is 0-5.These copolymers have improved resistance to stress cracking. They may also be used in applications such as coatings, or adhesives.

Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines, one or more additional comonomers selected from the group consisting of a tetrafunctional aromatic dianhydride, an aromatic or aliphatic dicarboxylic acid (or acid derivative thereof) and mixtures thereof, and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein Z is CF.sub.3 or a phenyl radical.

Abstract: The solvent-resistance and thermal stability of polyamideimides of the general formulae: ##STR1## is improved by capping the amideimides with a crosslinking functionality (Y) containing a residue selected from the group of: ##STR2## wherein R.sub.1 =lower alkyl, lower alkoxy, aryl, aryloxy, substituted alkyl, substituted aryl (either including hydroxyl or halo-substituents), halogen, or mixtures thereof;j=0, 1, or 2;G=--CH.sub.2 --, --O--, --S--, --SO.sub.2 --, --SO--, --CO--, --CHR--, or --CR.sub.2 --;R=hydrogen, lower alkyl, or phenyl;T=methallyl or allyl;Me=methyl;R.sub.2 =a trivalent organic radical; andR.sub.3 =a divalent organic radical.The amideimide oligomers may be linear or multidimensional, and can be processed into blends, prepregs, or composites. Methods of making these amideimides and intermediates useful in the syntheses are also described.

Abstract: Disclosed is a solution in butyrolactone of a diglyme-insoluble polyimidesiloxane. The polyimidesiloxane is the reaction product of a dianhydride selected from the group consisting of 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-oxydiphthalic anhydride, and mixtures thereof, with a mixture of a non-siloxane diamine and a siloxane diamine in a molar ratio of about 0.1 to about 16, where said non-siloxane diamine is selected from the group consisting of 2,4-diaminotoluene, 3,5-diamino-tert-butylbenzene, 2,5-diamino-trifluoromethyl benzene, 2,6-diamino-4-trifluoromethyl pyridine, and mixtures thereof.

Abstract: Novel polyimide based films are disclosed that are resistant to arc tracking and that include aromatic dianhydrides together with aromatic diamines and aliphatic diamines. The compositions contain from 5 to 20 percent by weight of the aliphatic diamine. These compositions maximize the thermal aging capability of the polyimide. The compositions are useful as films and laminates for wire and cable.

Abstract: Novel halogenated polyimides and co-polyimides comprise recurring imide structural units of the formula ##STR1## where X is F, Cl, Br or I; Y is H, F, Cl, Br or I; and R is a divalent organic radical.

Abstract: A process is disclosed for preparation of anhydrides containing additional carboxylic acid moieties and dianhydrides of disubstituted maleic anhydride compounds wherein the acid anhydrides and dianhydrides retain their alkene character. The resulting alkene compounds are useful as precursors for polyesters, thermally stable polyamide-imides and polyimides which are also disclosed, as well as a process for their preparation.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis-(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or tetraalkylester of an aromatic tetracarboxylic acid, (b) an aromatic diamine, and (c) an end cap compound. The ratio of (a), (b), and (c) is chosen so that upon heating the mixtures, low molecular weight prepolymers are formed, the prepolymers having only one end cap radical and being suitable for chain extension and crosslinking to form high molecular weight, thermally stable polyimides. Upon heating, the prepolymers form polyimide resins, which can have T.sub.g in excess of 600.degree. F. and superior physical properties.

Abstract: Polyimides useful in multilayer electronic devices containing the 4,4'-bis(4-amino-2-trifluoromethylphenoxy) biphenyl moiety have low dielectric constants, low moisture uptake, high thermal degradation stability, low glass transition temperature.

Abstract: New polyphenylated polynuclear aromatic diamines, such as 1,3-bis[4-aminophenyl]-2,3,5-triphenylbenzene, a process for their manufacture and their use as polycondensation components for the manufacture of polyamide, polyamide-imide and polyimide polymers are described. The polymers obtained with the aromatic diamines according to the invention are readily soluble, rigid-rod polymers and are distinguished by outstanding modulus, tensile compression strength, energy absorption, coefficient of expansion and electrical properties.

Abstract: The present invention provides diamino compounds and liquid crystal aligning films comprising polyimides which are obtained from the said diamino compounds represented by the general formula: ##STR1## wherein R.sub.1 indicates an alkyl group having 3 to 22 carbon atoms, R.sub.2 indicates a hydrogen atom or an alkyl group having 1 to 22 carbon atoms, and R.sub.3 -R.sub.10 indicate a hydrogen atom or a methyl group, respectively.The liquid crystal aligning films are useful for STN mode display cells in realizing a high pretilt angle.

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: 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 polyimide thin film is formed on a substrate by imparting energy under vacuum, by means of heating, ultraviolet light or electron beam irradiation, or a combination thereof, to a polyimide having in the polymer main chain imide bonds and decomposable bonds such as carbon-carbon single bond differing from the imide bonds so as to break the decomposable bonds.

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: High molecular weight polyamide-imides having a reduced viscosity of 0.3 dl/g or above and exhibiting excellent heat resistance and melt flowability are produced with good economic efficiency by a process, which process comprises the two reaction stages:(a) a first reaction stage which comprises reacting (I) a trimetallitic acid derivative and (II) an aromatic diamine in the presence of a polar solvent in the presence of a first dehydration catalyst until a polyamide-imide resin having a reduced viscisity of 0.2 to 0.5 dl/g as measured at a concentration of 0.5 g/dl in dimethylformamide at 30.degree. C. is produced; and(b) a second reaction stage which comprises adding a phosphorous triester as a second dehydration catalyst to the reaction mixture resulting from the first reaction stage and further reacting the reaction mixture until a high molecular weight polyamide-imide resin having a reduced viscosity of 0.3 dl/g or above as measured at a concentration of 0.5 g/dl in dimethylformaide at 30.degree. C.

Abstract: A photosensitive amphiphilic high polymer comprises a linear recurring unit containing at least divalent 1st organic group (R.sup.1) having at least two carbon atoms and at least divalent 2nd organic group (R.sup.2) having at least two carbon atoms, said organic groups R.sup.1 and R.sup.2 being connected to each other by a divalent linkage group formed by a reaction of an acid group (A) containing a hetero atom and a basic group (B) containing a hetero group; and at least one hydrocarbon-containing group having 10 to 30 carbon atoms, which may have a substituent, bonded to said recurring unit by a covalent bond or an ionic bond; and a dimerizable or polymerizable unsaturated bond or an orthonitrobenzyl group ##STR1## which may have a substituent, contained in a part or the whole of said recurring unit.

Abstract: Disclosed is a process for preparing a polyimide by reacting certain reactants. The reactants include an aromatic diamine which is 3,3'-diaminobenzophenone and/or bis(3-aminophenyl)sulfone, a tetrocarboxylic dianhydride and a dicarboxylic anhydride. A thermally stable polyimide can be obtained which displays excellent processability.

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: The present invention provides polyamides produced by the condensation of diamines with citric acid through the carboxyl groups attached to the carbon atoms in positions 1 and 3.These polyamides can be used for the preparation of controlled-release forms of drugs.

Abstract: The present invention here disclosed is directed to a photosensitive polymer having an inherent viscosity of 0.1 to 5 dl/g and represented by the general formula ##STR1## wherein R.sup.1 is independently a trivalent or tetravalent carbon cyclic aromatic group or heterocyclic group; R.sub.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.sub.3 and R.sub.4 are CH.sub.2 --CH.dbd.CH.sub.2 ; m is 1 or 2; n is 0 or 1; and m and n satisfy 1.ltoreq.m+n.ltoreq.2.The photosensitive polymer of the present invention is applicable as electronic materials such as passivation films of semiconductors and print circuits.

Abstract: Composite materials with matrices of tough, thermoplastic aromatic polyimides are obtained by blending semi-crystalline polyimide powders with polyamic acid solutions to form slurries, which are used in turn to prepare prepregs, the consolidation of which into finished composites is characterized by excellent melt flow during processing.

Abstract: Soluble, film-forming, polyamides, polyimides, and polyamide-imides and their copolymers made using 3,5-diamino-t-butylbenzene are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high Tg, excellent thermal stability, lower density and lower moisture uptake and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: A crosslinked copolymer composition is derived from an aliphatic polyester, a dianhydride and a diisocyanate. The copolymer membrane has high thermal stability and good aromatic/saturate selectivity and permeability.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butylbenzenes are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamino-t-butylbenzenes which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: This invention relates to molding resin compositions, and more particularly relates to polyimide resin compositions having markedly improved molding ability in addition to excellent high temperature stability, chemical resistance and mechanical strength.The polyimide resin compositions of this invention comprises 99.9 to 50.0% by weight of the polyimide and 0.1 to 50.0% by weight of aromatic polyamideimide.

Abstract: Diamines having a 1,1,3-trimethylphenylindane dicarboxylic moiety linked on both sides to phenylene diamine by an amide bond (PIDA diamines) are disclosed. By reacting these diamines with aromatic difunctional acid derivatives, amorphous polymers having high glass transition temperatures (Tg) can be prepared. If aliphatic diacid derivatives are used the resulting polymers have a lower Tg, but have the advantage of melt-processability. The PIDA-diamines can also be used in the preparation of polyimides, being reacted either with tri- or tetracarboxylic anhydrides or with imide group-containing acid derivatives.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butylbenzens are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamino-t-butylbenzenes which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butyltoluene are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamino-t-butyltoluene which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

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 copoly(imidine-imide) consisting of a copolymer of polyimidines and polyimides having, in the basic chain structure of the polymer, imidine structures represented by formula (I) and the imide structures represented by formula (II): ##STR1##

Abstract: A copolymerized polyamic acid salt having a recurring unit represented by following formula (I) and (II) and the process for preparing thereof. ##STR1## wherein (A) or (A') represents a formula ##STR2## wherein, R.sup.1 represents a tetravalent group having at least 2 carbon atoms; R.sup.2 represents a divalent group having at least 2 carbon atoms; and R.sup.31, R.sub.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5, and R.sup.6 each represents a monovalent group having 1 to 30 carbon atoms selected from an aliphatic group, an alicyclic group, an aromatic group, a group in which an aliphatic group is combined with an alicyclic group or an aromatic group, each of these groups substituted by a halogen atom, a nitro group, an amino group, a cyano group, a methoxy group, or an acetoxy group, or a hydrogen atom; at least one of said R.sup.31, R.sup.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5 and R.sup.

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 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: Methods of solution processing of rigid chain and ladder polymers to films, coatings, or fibers from isotropic or anisotropic solutions in aprotic organic solvents containing Lewis acids are disclosed.

Abstract: A patterned thin film suitable for use in electric and electronic devices, prepared from a polymer or a mixture of the polymer and other known compounds capable of forming a thin film by LB technique, said polymer having linear recurring units wherein an organic group R.sup.1 having at least 2 carbon atoms and a valence of at least 2 is combined alternately with an organic group R.sup.2 having at least 2 carbon atoms and a valence of at least 2 through a bivalent group formed by a reaction of an acid group A containing a hetero atom and a basic group B containing a hetero atom, and wherein a hydrocarbon-containing group R.sup.3 having 10 to 30 carbon atoms which may contain a substituent group, is linked by covalent or ionic bond to said recurring units, the number of groups R.sup.3 being at least 2 per 10 recurring units.

Abstract: Novel polymers containing amide and imide moieties are produced by reaction of a spirodilactam precursor selected from 4-oxoheptanedioic acid compounds or 1,6-dioxa [4,4] spirodilactones, a primary diamine and an aromatic tricarboxylic acid compound. The polymer products have relatively high glass transition temperatures.

Abstract: The present invention relates to a copoly(imidineamide) consisting of a copolymer of polyamidines and polyimides having, in the basic chain structure of the polymer, imidine structures represented by formula [I] and the amide structures represented by formula [II]: ##STR1## The copoly(imidine-amide) of the present invention is a polymeric material of excellent heat resistance and processability useful for a wide range of industrial applications.

Abstract: An amphiphilic high polymer comprises a linear recurring unit containing at least divalent organic group (R.sub.1) having at least two carbon atoms, at least divalent organic group (R.sub.2) having at least two carbon atoms, and at least one C.sub.10-30 hydrocarbon-containing group (R.sub.3) which may have one or more substituent groups, said organic groups R.sub.1 and R.sub.2 being connected to each other by a divalent connecting group, and said hydrocarbon-containing group R.sub.3 being boned to said recurring unit by a covalent bond, and the method for producing the same comprises polycondensating a combination of monomers containing R.sub.1 and R.sub.2.

Abstract: The present invention comprises a water dispersible polyamide ester useful in flexographic ink formulations and Cold Seal Release Lacquers. A high AV polyamide is reacted with a polyol to increase molecular weight via ester formation. The polyamide ester is then reacted with a cyclic carboxylic anhydride. A general formula for the product resin is as follows: ##STR1## wherein x is an integer of 1-5; R'=a polyamide ester chain of molecular weight 500-2000; where y is an integer of 1-3; R.sup.2 is independently at each occurrence the residue of a cyclic carboxylic anhydride bearing at least one free carboxyl group or ##STR2## where R.sup.3 is independently at each occurrence R' or a polyamide segment of up to 2000 MW.

Abstract: A polymer has a linear recurring unit in which a first organic group (R.sub.1) having at least two carbon atoms and a valence of at least three and a second organic group (R.sub.2) having at least two carbon atoms and a valence of at least two are bonded together alternatively through a divalent connecting group, and containing at least one hydrocarbon group (R.sub.3) having 10 to 30 carbon atoms which is linked to the recurring unit by an ionic bond and which may be substituted.

Abstract: Thermotropic polyesterimides based on N-(.omega.-carboxyalkylene)-trimellitic acid imides and diphenols are distinguished by superior mechanical properties while at the same time being easily processible.

Abstract: Dense star polymers on immobilized cores are very useful as ion-exchange resins and chelation resins. For example, an aminated form of chloromethylated styrene/divinyl benzene copolymer can be employed as an immobilized core compound and reacted successively with methyl acrylate via a Michael addition reaction and then with ethylenediamine to form a first generation dense star polymer or dendrimer. These reactions can then be repeated to form second and third generation dendrimers.

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: A thin film comprising a polymer having linear recurring units wherein an organic group R.sup.1 is combined alternately with an organic group R.sup.2 through a bivalent bonding group, wherein each of said group R.sup.1 and said group R.sup.2 has a valence of at least 2 and has at least 2 carbon atoms; each of said linear recurring units having at least one hydrocarbon-containing group R.sup.3 having 10 to 30 carbon atoms bonded with covalent bond, and a device having the thin film. The thin film of the invention is formed by building-up layers of the above polymer by LB technique, and the obtained film can be subjected to ring closure and to elimination of a known LB compound added as occasion demand by heat treatment to provide a thin film having a thickness of not more than 10,000 .ANG. and excellent heat resistance, chemical resistance and mechanical properties, and the device having the thin film is useful particularly as electric and electronic devices.

Abstract: The thermoplastic aromatic polyamideimide compolymers comprising the structural units (1), (2) and (3) represented by formulae, ##STR1## respectively, (2) and (3) being at ratio of 1 mole to 1 mole of (1), (3) being at a ratio of 0.95-0.05 mole to 0.05-0.95 mole of (2), (1) and (2) or (3) being alternatively interconnected and Ar and Ar' being composed of 5 to 70 mole % of ##STR2## and 95 to 30 mole % of ##STR3## provide the moldings being superior in heat stability and fluidity at the temperatures of 300.degree. to 400.degree. C. and injection moldable and having desired characteristics.

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.