Abstract: Disclosed herein are novel poly(imide-ethers) containing ortho substitution in the main chain of the polymer. These polymers are made from novel aromatic bis-carboxylic anhydrides which contain two ether groups attached to an aromatic ring in ortho positions to each other. The polymers are particularly useful for films, fibers and encapsulation, as well as thermoplastics.

Abstract: A thermotropic polyesterimide, in which the liquid-crystalline phase is of nematic structure within a useful temperature range, consists of units of formula: ##STR1## the units being in the following ratios:a/(b+c)=1c/b=0-50/50, and preferably c/b<30/70The polyesterimide of the present invention possesses self-reinforcement characteristics, or reinforcement characteristics for traditional thermoplastic materials.

Abstract: A series of polyimides based on the dianhydride of 1,4-bis(3,4-dicarboxyphenoxy)benzene (HQDEA) or on 2,2-bis[4(3-aminophenoxy)phenyl]hexafluoropropane (3-BDAF) are evolved from high molecular weight polyamic acid solutions yielding flexible free-standing films and coatings in the fully imidized form which have a dielectric constant in the range of 2.5 to 3.1 at 10 GHz.

Abstract: Described herein is a process for synthesizing polybenzazole polymers comprising: (a) contacting a bis(trihalomethyl) organic compound with a polyphosphoric acid under reaction conditions sufficient to convert at least about 25 mole percent of the trihalomethyl groups present to carboxylic acid or carboxylate groups, forming a reaction mixture thereby; and (b) contacting the reaction mixture with an aromatic compound having two o-amino-basic moieties under reaction conditions sufficient to form a polybenzazole polymer.

Abstract: Four phenylethynyl amine compounds--3 and 4-aminophenoxy-4'-phenylethynylbenzophenone, and 3 and 4-amino-4'-phenylethynylbenzophenone--were readily prepared and were used to endcap imide oligomers. Phenylethynyl-terminated amide acid oligomers and phenylethynyl-terminated imide oligomers with various molecular weights and compositions were prepared and characterized. These oligomers were cured at 300.degree. C. to 400.degree. C. to provide crosslinked polyimides with excellent solvent resistance, high strength and modulus and good high temperature properties. Adhesive panels, composites, films and moldings from these phenylethynyl terminated imide oligomers gave excellent mechanical performance.

Abstract: Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Abstract: Polyimide oligomers are described which comprise the intercondensation product of a monomer mixture comprising (A) at least one aromatic bis(ether anhydride), (B) at least one phenylindane diamine, and (C) at least one end-cap monomer selected from the group consisting of monoanhydrides, acyl halides and amines, wherein each end-cap monomer (C) contains at least one crosslinkable group in the molecule and wherein the phenylindane diamine component (B) is present in the mixture in a stoichiometric excess. The monomers react in a suitable solvent under an inert atmosphere to form polyimide oligomers having a number average molecular weight of from about 1,000 to about 15,000. The polyimide oligomers of the present invention are readily processed to form polyimide matrix resins with high temperature and oxidative stability.

Abstract: Novel poly(N-arylenebenzimidazole)s (PNABIs) are prepared by the aromatic nucleophilic displacement reaction of novel di(hydroxyphenyl-N-arylene benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl-N-arylenebenzimidazole) monomers are synthesized by reacting phenyl-4-hydroxybenzoate with bis(2-aminoanilino)arylenes in diphenylsulfone. Moderate molecular weight PNABIs of new chemical structures were prepared that exhibit a favorable combination of physical and mechanical properties. The use of the novel di(hydroxyphenyl-N-arylenebenzimidazole)s permits a more economical and easier way to prepare PNABIs than previous routes.

Abstract: Liquid-melt aliphatic dicarboxylic acids tend to undergo undesirable discoloration during prolonged storage. The discoloration can be avoided by an addition of 0.1 to 3.0% by weight of a primary amine.

Abstract: This invention concerns positive-working photodefinable polyimide precursors which make use of chemical amplification based on photoacid catalyzed cleavage of acid labile-poly(amic acetal esters).

Abstract: A random polyimide copolymer, based on a rigid dianhydride, a rigid diamine and an additional diamine and/or dianhydride containing one or more flexibilizing linkages. Soft-baked coatings of the poly(amic acid) precursor are readily processed using conventional aqueous base developers, such as tetramethylammonium hydroxide. The polyimide and soft-baked coatings are useful as a dielectric layer In multichip module applications or as a stress buffer coating.

Abstract: Polybenzoxazole or polybenzothiazole polymer dopes are spun through a spinneret having an orifice density of more than 0.25 per cm.sup.2 to form filaments. The filaments formed then pass through an air gap which has a gas flowing into it at a temperature of between about 5.degree. C. to about 100.degree. C. and at a flow rate between about 0.1 meters/second and about 2.0 meters/second. The filaments cool in the air gap and are then coagulated. During or after coagulation the filaments are combined into one or more fibers. By this method of controlling the temperature in the air gap it is possible to stably spin polybenzoxazole or polybenzothiazole fibers at relatively high final line speeds.

Abstract: There are disclosed flame-retardant, high temperature resistant polyimide fibers of the general formula ##STR1## wherein n is an integer larger than 1, A is a tetravalent aromatic group and R is at least one divalent aromatic group. These polyimide fibers have been heat-treated in the unstretched state and have a maximum shrinkage of 14% when heated to a temperature of 400.degree. C. These polyimide fibers are produced by initially spinning crude fibers from a solution of the appropriate polyimide in an aprotic organic solvent, preferably according to the dry-spinning method, which solution optionally contains additives. The crude fibers obtained are washed with water to remove the solvent. The washed crude fibers are dried to a moisture content of less than 5% by mass, are subjected to a heat treatment at a temperature of between 315.degree. C and 450.degree. C, are cooled and, if desired, are crimped and cut to staple fibers.

Abstract: Thermoplastic polyester-imides having improved mechanical properties, characterized in that they consist of recurring units of the formula I ##STR1## in which R denotes an 2,4-tolylene, 2,6-tolylene, 2,5-bis(4-phenylenethio) thiadiazole,or a 1,4-bis(phenylenethio)diphenyl sulfone radical, a process for their preparation and their use for the production of industrial components of plastic.

Abstract: A process for preparing polyimide fibers involves the preparation of a polymer in p-chlorophenol from reactants comprising 2,2'-dimethyl-4,4'-diaminobiphenyl and a tetracarboxylic anhydride. Following its preparation, the polyimide fibers can be spun directly from the reaction mixture. In a preferred embodiment, the dianhydride comprises 3,3',4,4'-biphenyltetracarboxylic dianhydride.

Abstract: Polyimide filaments and polyimide films having great strength, high elastic modulus and high crystallinity and comprising a novel polyimide which can be melt-processed without impairing high crystallinity and which essentially consists of recurring structural units represented by the formula (I): ##STR1## more than 85 mol % the polyimide consists of recurring structural units of the formula (II): ##STR2## and from 0.5 to 15 mol % of the polyimide consists of recurring structural units represented by the formula (III), the formula (II) exclusive, the formula (IV) and/or the formula (V).

Abstract: Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.

Abstract: Amorphous polyimide powder which has recurring structural units of the formula (I): ##STR1## as a fundamental skeleton, is blocked at the polymer chain end with dicarboxylic anhydride represented by the formula (II) ##STR2## wherein Z is a divalent radical having from 6 to 27 carbon atoms and selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected to each other with a direct bond or a bridge member, and essentially has no reactive radical at the polymer chain end, preparation process of the amorphous polyimide powder, heat-resistant adhesive comprising the polyimide, and bonding method using the adhesive.

Abstract: Films containing polybenzazole polymer dissolved in a solvent can be mechanically stretched to provide biaxial orientation. The resulting dope film can be coagulated. The polymer film has improved properties in the direction in which stretching occurs.

Abstract: An aromatic copolyamide which is soluble in organic copolyamide solvents and contains recurring structural units of formulae I, II and III ##STR1## in which at least some of the radicals R.sup.1 are a group of formula --OC--R.sup.2 --CO--, in which R.sup.2 is a divalent aromatic radical having valence bonds in the para-position or in a comparable coaxial of parallel position to one another, and in which the remaining radicals are as defined.

Abstract: A process for making PBZ fibers of ultra-high physical properties is given. Polybenzoxazole fibers made by the process of this invention have tensile strengths nearly double in value from what has been reported previously.

Abstract: A polyimide comprising a requisite structural unit having one or more recurring structural units of the formula: ##STR1## such as the structural units of the formula ##STR2## The polyimide can have an extremely low dielectric constant and is colorless, transparent and excellent in processability and heat resistance, and also provides an aromatic diamine which is useful as a raw material monomer of the polyimide or a raw material of other various engineering plastics.

Abstract: The aromatic heterocyclic copolymer is produced by (a) reacting (i) an aromatic diaminodithiol compound, hydrogen atoms of thiol groups of which compound are substituted with substituted or unsubstituted alkyl groups, with (ii) an aromatic diamino compound and (iii) a dicarboxylic acid derivative in an organic solvent, to produce a precopolymer; and (b) heating the precopolymer to cause a thiazole ring closure reaction. This aromatic heterocyclic copolymer is contained as a reinforcing polymer in a molecular composite material.

Abstract: Dithioether-linked phthalonitrile monomer are prepared by a substitution reaction between 4-nitrophthalonitrile and a dimercaptan and are polymerized to a high-temperature, oxidation-resistant polymer by heating them at a temperature above their melting point. The rate of polymerization is increased by the addition of an amine. Electrical conductivity of the polymer can be increased to the conductor range by heating the polymer above about 400.degree. C.

Abstract: A polyimide-based heat-resistant adhesive having excellent peel strength and heat resistance comprising polyimide composed of 10 to 99% by mole of structural units having the formula (1) and 1 to 90% by mole of structural units having the formula (2) or comprising polyamic acid precursor which corresponds to the polyimide.

Abstract: A structure which is effective as an electrical insulator or as a transmitter-receiver of electromagnetic energy is prepared by providing a suitable substrate and covering the substrate with an adhering layer of a low dielectric, high temperature, linear aromatic polyimide.

Abstract: A polyimide gas separation membrane containing repeating units derived from 9,9-disubstituted xanthene dianhydride is disclosed.

Abstract: Aromatic copolyamides are described which are soluble in organic polyamide solvents and which comprise the recurring structural units of the formulae Ia, Ib, Ic and Id[--OC--R.sup.1 --CO--NH--R.sup.2 --NH--] (Ia),[--OC--R.sup.1 --CO--NH--R.sup.3 --NH--] (Ib),[--OC--R.sup.1 --CO--NH--R.sup.4 --NH--] (Ic),[--OC--R.sup.1 --CO--NH--R.sup.5 --NH--] (Id)in whichR.sup.1 and R.sup.2 are mainly unsubstituted divalent aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another,R.sup.3 is a radical of the formula II ##STR1## R.sup.4 is a radical of the formula III--Ar.sup.1 --O--Ar.sup.1 --O--Ar.sup.1 -- (III), andR.sup.5 is a radical of the formula IV and/or V ##STR2## in which Ar.sup.1 has one of the meanings defined for R.sup.

Abstract: Copolyimide compositions and methods for their preparation which are melt-processible at relative low pressures, i.e. less than 1000 psi, and are suited for laminating and molding, are described. The invention additionally encompasses copolyimide precursors, reinforced polyimide composites and laminates made from said polyimides where the composite is reinforced by fibrous materials. This is achieved by reacting at least one aromatic dianhydride where each anhydride group is located on an aromatic ring with the carbonyl units in an ortho orientation relative to one another, with at least one diamine which is capable of a transmidization reaction upon incorporation into the polyimide backbone, and with at least one other diamine which is not capable of undergoing such reaction, the diamine which is capable of undergoing the transimidization reaction being present in an amount of from about 1-50 mole percent in relation to the diamine that is not susceptable to transimidization.

Abstract: Low dielectric constant polyimides formed from an optionally fluorinated dianhydride and a fluorinated diamine are described. The fluorine containing constituents are sterically disposed so that the dipole moment of the constituents tend to cancel out. Since fluorine containing diamines are generally nonreactive, to achieve a polyimide of high enough molecular weight to be practically useful, a method of fabrication of a high molecular weight polymer from monomers of low reactivity is provided. The monomers, such as a diamine and dianhydride are provided in a solution within which a low molecular weight polyamic acid is formed. The solution is dried. The polyamic acid used is cured to a low molecular weight polyimide. The polyimide is redisolved, redryed and recured enough times to build up the molecular weight to a useful level. The method is applicable to fabricating other polymers of high molecular weight, such as polyamides, polyesters and polyurethanes.

Abstract: Polyimide compositions, films, and electronic devices using polyimides, based on 9-aryl-9(perfluoroalkyl)xanthene-2,3,6,7-dianhydride or 9,9'-bis(perfluoroalkyl)xanthene-2,3,6,7-dianhydride and benzidine derivatives. These polyimides offer a combination of low linear coefficient of thermal expansion, low dielectric constant, and low water absorption.

Abstract: In reactions to form PBZ polymers such as polybenzoxazole, monomers having an aromatic group bonded to a primary amine group and to a hydroxy, thio or amine group ortho to said primary amine group are contacted with monomers having an electron-deficient carbon group. In the present invention the electron deficient carbon group may be an alkali metal carboxylate group or a trihalomethyl group. Useful monomers include, for example, .alpha.,.alpha.,.alpha.,.alpha.',.alpha.',.alpha.'-hexachloroxylene and disodium terephthalate.

Abstract: A polyamide precursor of a polybenzazole polymer is prepared by reacting an aromatic bis(alkenyl)ester with a ring forming, aromatic diamine. The precursor can be prepared in an organic solvent for the monomers to form a soluble polyamide precursor which can be subsequently cyclocondensed to form a PBX polymer. A polybenzoxazole precursor is prepared by the reaction of a bis(alkenyl)ester and a bis(ortho-hydroxyamine). A polybenzazole polymer is easily prepared by heating the polyamide, PBX precursor.

Abstract: A thermoplastic resin composition comprise 99.9.about.50 parts by weight of one or more thermoplastic resin selected from the group consisting of aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyethersulfone and aromatic polyether ketone and 0.1.about.50 parts by weight of one or more liquid crystal type aromatic polyimide having recurring structural units represented by the formula (1): ##STR1## wherein R.sub.1 .about.R.sub.5 is a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl or cyano and may be the same or different, and R is a tetravalent radical having 6.about.27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member.

Abstract: Polyimide optical waveguide structures comprising a core within a cladding wherein at least one of the core and the cladding is a polyimide containing 6FDA, BTDA, an aromatic diamine having bulky methyl groups ortho to the amine, and a co-diamine wherein the polyimides have the properties of low optical loss, low optical absorbance, controllable refractive index, and high thermal stability, and wherein the polyimides are photosensitive and solvent resistant.

Abstract: Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-4-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

Abstract: Para-ordered aromatic heterocyclic polymers having repeating units of the formula: ##STR1## wherein n has a value of 0.05 to 1.00 and Q is a benzobisazole of the formula ##STR2## wherein X is --S-- or --O--, are soluble in aprotic solvents.

Abstract: Copolyamic acids carrying -CF3 group functionalized aromatic segments in the polymer chain derived from aromatic diamines and dianhydrides with linear-rigid-planar structure interrupted by linear-rigid-noncoplanar segments structure and the corresponding copolyimides films are provided. These copolyimides have low in-plane thermal coefficient of expansion, reduced anisotropy in the optical and dielectric properties, low moisture uptake, and improved polyimide-to-polyimide adhesion.

Abstract: Phosphazene-containing amines having at least one amine or substituted amine moiety reactive with nitrile groups of the phthalonitrile monomers or oligomeric resins are useful curing agents for phthalonitriles. Typically, the phosphazene-containing amines useful as curing agents in the present invention have the formula: ##STR1## wherein each of X.sub.1-6 is a hydrogen, an unsubstituted amine group, or an amine group substituted with C.sub.1 -C.sub.12 alkyl groups or aromatic groups, at least one of X.sub.1-6 includes an amine group, and each of R'.sub.1-6 is an alkyl, aromatic, or alkyl-substituted aromatic moiety, or a linear polymer of the phosphazene-based amine monomer. The curing agents enhance the speed of cure and also add flame retardancy to the cured polymers.

Abstract: Novel polyimides containing pendent siloxane groups (PISOX) were prepared by the reaction of functionalized siloxane compounds with hydroxy containing polyimides (PIOH). The pendent siloxane groups on the polyimide backbone offer distinct advantages such as lowering the dielectric constant and moisture resistance and enhanced atomic oxygen resistance. The siloxane containing polyimides are potentially useful as protective silicon oxide coatings and are useful for a variety of applications where atomic oxygen resistance is needed.

Abstract: A chemical resistant copolymer useful in electronic applications, said copolymer is a polyimide containing a 3,3',4,4'-tetracarboxybiphenyl dianhydride (BPDA) moiety, at least one other dianhydride moiety, and at least one diamine.

Abstract: The diamine, 1,3-diamino-5-pentafluorosulfanylbenzene (DASP), was reacted with various dianhydrides to form polyimides containing an SF.sub.5 moiety. These polyimides exhibit high glass transition temperatures, high density, low solubility, and low dielectric properties. These polymers were used to prepare semi-permeable membranes, wire coatings, and films and are useful for electronic, space and piezoelectric applications.

Abstract: A silicon-modified, adhesive polyimide film composed mainly of the repetition units of the formula (I) and a process for producing a polyimide film composite product using the above film are provided, the formula (I) being ##STR1## the above process for producing a polyimide film composite product comprising subjecting the above-silicon-modified polyimide film to contact-bonding on heating to a material to be adhered, at an ultimate curing temperature of 130.degree.-230.degree. C.The above polyimide film is highly adhesive and heat-resistant in spite of heating at a relatively low temperature.

Abstract: The present invention relates to a liquid crystal alignment treating agent which comprises a polyimide resin prepared from a diamine including an aromatic diamine having at least one linear alkyl group of at least 6 carbon atoms per benzene ring as the essential component and a tetracarboxylic acid and its derivative.The liquid crystal alignment treating agent obtained in accordance with the present invention comprises a polyimide resin having an alkyl group on a side chain, and accordingly provides a liquid crystal-aligned film containing liquid crystal molecules stably having an enhanced inclined alignment angle (tilt angle) to a substrate.

Abstract: The present invention provides a dehydrating agent which is less poisonous and which can be easily handled in producing a polyisoimide by dehydrating a polyamic acid. A process is also provided for producing a polyisoimide without requiring the separation of by-products.That is, the process for producing the polyisoimide of the present invention includes the step of using a dihyroquinoline derivative represented by the formula ##STR1## (wherein each R.sup.1 and R.sup.2 is independently a monovalent organic group having 1 to 8 carbon atoms) as the dehydrating agent in producing the polyisoimide by dehydrating the polyamic acid.

Abstract: Articles (other than fiber) made from polybenzazole dopes can quickly be washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at at least about 60.degree. C. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Abstract: Films made from polybenzazole dopes can quickly be leached to remove polyphosphoric acid and other residual solvents by passing a leaching fluid such as steam through pores in the wet, never dried film. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Abstract: A polyimide composition for use in making polyimide/copper foil laminate that does not require an adhesive layer between the polyimide substrate and the copper foil. A polyimide precursor is first prepared from a monomer composition, which comprises a dianhydride and an imidazole-containing or benzimidazole-containing compound, or mixture thereof The polyimide precursor is then coated onto a copper foil and subsequently subject to an imidization reaction to form a polyimide/copper foil laminate, which exhibits excellent peel strength and flatness while retaining all the advantageous properties that are characteristic of polyimide resins, such as excellent mechanical strength and heat and chemical resistance. Because the polyimide/copper foil laminates disclosed in the present invention are made without the need to apply an adhesive layer, the process of manufacturing the same is greatly simplified and the cost of production therefor can be substantially reduced.

Abstract: There are described aromatic copolyamides which are soluble in organic polyamide solvents and which consist essentially of recurring structural units of the formulae Ia, Ib and Ic on the one hand and Ia, Ib and Ie on the other[--OC--R.sup.1 --CO--NH--R.sup.2 --NH--] (Ia), [--OC--R.sup.1 --CO--NH--R.sup.3 --NH--] (Ib),[--OC--R.sup.1 --CO--NH--R.sup.4 --NH--] (Ic), [--OC--R.sup.1 --CO--NH--R.sup.7 --NH--] (Ie),where R.sup.1 and R.sup.7 are divalent aromatic radicals whose valence bonds are in the para or a comparable coaxial or parallel position relative to one another, R.sup.2 is a radical of the formula III ##STR1## and R.sup.3 and R.sup.4 are radicals of the formula IV ##STR2## where Z is --O--, --S--, --CO--, --SO.sub.2 --, C.sub.1 -C.sub.10 -alkylene or --O--R.sup.1 --O-- and R.sup.6 is in each case hydrogen or an inert substituent.The mole fractions of the individual structural features in the copolyamides are defined within selected limits.

Abstract: A process for making PBZ fibers of ultra-high physical properties is given. Polybenzoxazole fibers made by the process of this invention have tensile strengths nearly double in value from what has been reported previously.