Abstract: A polyimide for optical communications, which is expressed by the formula (1), a method of preparing the same, and a method of forming multiple polyimide films using the polyimide, wherein the formula (1) is given by X1, X2, X3, A1, A2, B1, B2, B3, D1, D2, E1, E2, Y1, Y2, Y3, Y4, Y5, Y6, Y7, and Y8, are independently selected from the group consisting of hydrogen atom, halogen atom, alkyl group, halogenated alkyl group, aryl group and halogenated aryl group; Z is a simple chemical bond or selected from the group consisting of —O—, —CO—, —SO3—, —S—, —(T)m—, —(OT)m— and —(OTO)m—, wherein T is alkylene or arylene group substituted by at least one of halogen atom and halogenated alkyl group and m is an integer from 1 to 10; and n is an integer from 1 to 39.

Abstract: Polyimides and the process for preparing polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of one or more of the polyamines such as the aromatic diamines, one or more of the tetracarboxylic dianhydrides and a novel dicarboxylic endcap having a formula selected from the group consisting of: wherein R1 is either a radical where R is either hydrogen or an alkyl radical of 1 to 4 carbons, R2 is either OH, NH2, F, or Cl radical, R3 is either H, OH, NH2, F, Cl or an alkylene radical, R4 is either an alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical, and R5 is either H, alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical. The polyimides are useful particularly in the preparation of prepregs and PMR composites.

Abstract: The present invention provides a novel polyimide composition which includes a cinnamoyl group or a derived cinnamoyl group and has photo-reactivity and heat-reactivity inherent to the cinnamoyl group. Further, a novel diamine and an acid dianhydride according to the present invention are materials mainly used for preparing a novel polyimide composition having the cinnamoyl group or the derived cinnamoyl group in a main chain or a side chain.

Abstract: Polyimide copolymers were obtained containing 1,3-bis(3-aminophenoxy)benzene (APB) and other diamines and dianhydrides and terminating with the appropriate amount of reactive endcapper. The reactive endcappers studied include but should not be limited to 4-phenylethynyl phthalic anhydride (PEPA), 3-aminophenoxy-4′-phenylethynylbenzophenone (3-APEB), maleic anhydride (MA) and nadic anhydride (5-norbornene-2,3-dicarboxylic anhydride, NA). Homopolymers containing only other diamines and dianhydrides which are not processable under conditions described previously can be made processable by incorporating various amounts of APB, depending on the chemical structures of the diamines and dianhydrides used. By simply changing the ratio of APB to the other diamine in the polyimide backbone, a material with a unique combination of solubility, Tg, Tm, melt viscosity, toughness and elevated temperature mechanical properties can be prepared.

Abstract: Terminal-modified imide oligomers with an inherent viscosity of 0.05-1 obtained by reacting 2,3,3′,4′-biphenyltetracarboxylic dianhydride, an aromatic diamine compound and 4-(2-phenylethynyl)phthalic anhydride, and their cured products. There are provided highly practical terminal-modified imide oligomers and their cured products, which cured products have satisfactory heat resistance and mechanical properties.

Abstract: The present invention provides polyimides and co-polyimides that are organosoluble. The polyimides and co-polyimides are prepared from an aromatic diamine having ortho-linked phenylene and pendant tert-butyl group, i.e., 1,2-bis(4-aminophenoxy)-4-tert-butyl-benzene, or its mixture with other diamines, and a mixture of dianhydrides that containing at least one dianhydride selected from s-BPDA, DSDA, ODPA, 6FDA and other diether-dianhydrides.

Abstract: A polyimide film of birefringence less than 0.01 is formed by drawing a copolymerized polyimide comprising a block component and a random component which are molecularly bonded, wherein the block component of copolymerized polyimide comprises an aromatic diamine compound having a rigid structure and an aromatic tetracarboxylic acid compound and wherein the random component of copolymerized polyimide comprises an aromatic diamine compound having a flexible structure and at least two aromatic tetracarboxylic acid components. The resulting polyimide film has high elasticity, a low thermal expansion equivalent to that of metal and low water absorbing properties. A method for its manufacture and a metal laminated plate having improved curl properties in which the polyimide is used as the base material are also disclosed.

Abstract: The present invention relates to a treating agent for liquid crystal alignment, which is an agent for liquid crystal alignment to be used for a method in which polarized ultraviolet rays or electron rays are irradiated on a polymer thin film formed on a substrate in a predetermined direction relative to the substrate plane, and said substrate is used for aligning liquid crystal without rubbing treatment, wherein said agent for liquid crystal alignment contains a polymer compound having photochemically reactive groups in the polymer main chain and a glass transition temperature of at least 200° C.

Abstract: Polyimides and the process for preparing polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of one or more of the polyamines such as the aromatic diamines, one or more of the tetracarboxylic dianhydrides and a novel dicarboxylic endcap having a formula selected from the group consisting of: wherein R1 is either a radical where R is either hydrogen or an alkyl radical of 1 to 4 carbons, R2 is either OH, NH2, F, or Cl radical, R3 is either H, OH, NH2, F, Cl or an alkylene radical, R4 is either an alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical, and R5 is either H, alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical. The polyimides are useful particularly in the preparation of prepregs and PMR composites.

Abstract: Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with water-solubility- or water-dispersability-imparting substituents and at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula wherein x is an integer of 0 or 1, A is one of several specified groups, such as B is one of several specified groups, such as or mixtures thereof, and n is an integer representing the number of repeating monomer units. In one embodiment, a single functional group imparts both photosensitivity and water solubility or dispersability to the polymer. In another embodiment, a first functional group imparts photosensitivity to the polymer and a second functional group imparts water solubility or dispersability to the polymer.

Abstract: An aliphatic polyester amide which is hydrolysis-resistant includes a ternary polycondensation product of monomeric constituents composed of a monomeric constituent A which is at least one diol having a general formula: HO—R1—OH, where R1 is an aliphatic residue having 2-16 carbon atoms; a monomeric constituent B which is at least one dicarboxylic acid having a general formula: HOOC—R2—COOH, where R2 is an aliphatic residue having 1-14 carbon atoms; and a monomeric constituent C which is at least one diamine having a general formula: H2N—R3—NH2, where R3 is an aliphatic residue having 2-16 carbon atoms and is present in an amount of up to about 5% by weight based on total weight of the monomeric constituents, wherein polycondensation proceeds in the presence of a catalyst comprised of constituent D, which is a metal-containing catalyst, in combination with constituent E, which is at least one of an organic phosphorus compound and an inorganic phosphorus compound, and wherei

Abstract: The present invention provides a process for preparing an optical alignment layer for aligning liquid crystals and liquid crystal displays comprising exposing polyimide layers with polarized light. The invention further describes optical alignment layers, liquid crystal displays incorporating optical alignment layers and novel polymer compositions within the class of polyimide, polyamic acids and esters thereof.

Abstract: Polyether polymers such as polyetherimides are prepared by a two-step reaction. The first step is the reaction between an alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon, such as bisphenol A disodium salt, and a substituted aromatic compound such as 1,3-bis[N-(4-chlorophthalimido)]benzene, the alkali metal salt being employed in an amount less than stoichiometric. The intermediate low molecular weight polymer thus produced then undergoes reaction with additional alkali metal salt. By this method, a polyether polymer of closely controlled molecular weight can be conveniently prepared.

Abstract: Disclosed is a solvent soluble polyimide and a method for making thereof, which characterizes by producing a solvent soluble polyimide with low electric conductivity through the polymerization of an anhydride and a diamine under the condition with or without catalyst.

Abstract: Addition-cured polyimides that contain the reaction product of an aromatic triamine or trianhydride analogue thereof, a reactive end group such as 5-norbornene-2, 3-dicarboxylic acid, ester derivatives of 5-norbornene-2,3-dicarboxylic acid, anhydride derivatives of 5-norbornene-2,3-dicarboxylic acid, or 4-phenylethynylphthalic anhydride, an aromatic diamine, and a dialkyl ester of an aromatic tetracarboxylic acid. The resultant starlike polyimides exhibit lower melt flow viscosity than its linear counterparts, providing for improved processability of the polyimide. Also disclosed are methods for the synthesis of these polyimides as well as composite structures formed using these polyimides.

Abstract: Bi-component superabsorbent materials are disclosed. The superabsorbent materials comprise a mixture of about 20% to about 40%, by weight, poly-(vinylamine) polymer or other basic resin and about 60% to about 80%, by weight of an acidic water-absorbing polymer, like polyacrylic acid.

Abstract: A method for preparing polyamic acid and polyimide, which is suitable for use in adhesives or adhesive tapes for electronic parts. The polymers have such three-dimensional molecular structures that a significant improvement can be brought about in solvent solubility, thermal resistance, mechanical properties, and adhesive properties onto various substrates. The polyamic acid is prepared by reacting at least one tetracarboxylic dianhydride, at least one aromatic diamine, at least one diamine with a siloxane structure, represented by the following general formula I, and at least one polyamino compound represented by the following general formula II or III. The polyamic acid is converted into polyimide through thermal or chemical imidization.

Abstract: Bis(halophthalimides) such as, 3-bis[N-(4-chlorophthalimido)]benzene are prepared in slurry in an organic liquid such as o-dichlorobenzene or anisole, by a reaction at a temperature of at least 150° C. between at least one diamino compound, preferably an aromatic diamine such as m- or p-phenylenediamine, and at least one halophthalic anhydride such as 4-chlorophthalic anhydride, in the presence of an imidization catalyst such as sodium phenylphosphinate. The solids content of the reaction mixture is at least about 5% and preferably at least about 12% by weight. The product slurry may be employed directly in the preparation of polyetherimides, and similar slurries may be employed to prepare other polyether polymers.

Abstract: The present invention provides a liquid crystal-aligning agent including, as the resin component, a polyimide precursor containing a chemical structure represented by the following formula (1): The present invention further provides a liquid crystal-aligning agent including, the above polyimide precursor and a polyimide precursor represented by the following general formula (2): (wherein Y is a tetravalent aliphatic group, Z is a bivalent aromatic group, and R is H or an alkyl group).

Abstract: Essentially colorless, transparent polyimide coatings and films prepared by combining aromatic dianhydrides with para-substituted aromatic diamines are provided. The polyimide coatings and films are produced by a process whereby the dianhydride and diamine monomer components are reacted at temperatures of greater than 80° C.

Abstract: An grafted polymeric amine is provided, the grafted polymeric amine including: N-substituted 2,5-pyrrolediyl groups incorporated in the backbone wherein the N-substituted 2,5-pyrrolediyl group may be represented by the general formula wherein R independently represents a hydrogen or a hydrocarbyl group and B represents the substituent containing at least one primary amino group; and vinyl monomers grafted to a polyketone backbone. This grafted polymeric amine is useful as a component in a wood glue composition.

Abstract: High quality films, preimpregnated tape (prepegs) and composites have been fabricated from polyimide precursor “salt-like” solutions. These “salt-like” solutions have a low viscosity (5,000 to 10,000 cp) and a high solids content (50-65% by weight) and can be coated onto reinforcing fiber to produce prepegs with excellent tack and drape at 12-15% residual solvent (˜4-6% water from thermal imidization reaction). The processing of these types of prepegs significantly overcomes solvent removal problems and allows excellent fiber wet out. In addition, the physical characteristics of the polyimide precursor “salt-like” solutions permits processing into high-performance materials through the use of standard prepregging and composite fabrication equipment. The resultant composites are of high quality.

Abstract: In order to produce a polymer electrolyte membrane from sulfonated, aromatic polyether ketone, an aromatic polyether ketone of the formula (I) in which Ar is a phenylene ring having p- and/or m-bonds, Ar′ is a phenylene, naphthylene, biphenylene, anthrylene or another divalent aromatic unit, X, N and M, independently of one another are 0 or 1, Y is 0, 1, 2 or 3, P is 1, 2, 3 or 4, is sulfonated and the sulfonic acid is isolated. At least 5% of the sulfonic groups in the sulfonic acid are converted into sulfonyl chloride groups, and these are reacted with an amine containing at least one crosslinkable substituent or a further functional group, and unreacted sulfonyl chloride groups are subsequently hydrolyzed. The resultant aromatic sulfonamide is isolated and dissolved in an organic solvent, the solution is converted into a film, and the crosslinkable substituents in the film are then crosslinked.

Abstract: The invention relates to a process for preparing hydroxyl- and carboxyl-containing polyesterimide resins, comprising as monomeric components: (A) imide-forming compounds having at least two primary amino groups and/or at least two isocyanate groups or imide-forming compounds having at least one primary amino group and/or at least one isocyanate group and at least one further functional group selected from hydroxyl, carboxyl and/or carboxylic anhydride, (B) polycarboxylic acids and/or their anhydrides and/or their esters and (C) polyols, characterized in that (I) component (A) is reacted with part of component (B) to form a polyimide, (II) the polyimide obtained in accordance with stage (I) is reacted with component (C) to form a polyesterimide, and finally (III) the polyesterimide obtained in accordance with stage (II) is reacted with the remaining part of component (B) to form the Also embraced by the invention is the use of the polyesterimides prepared by the process according to the invention as bi

Abstract: The present invention relates to the synthesis of new type of diamine monomer, 1,3-bis(4-amonophenoxy)naphthalene, and with such a compound to produce a series of aromatic polymers, including polyamide, polyimide, copoly(amide-imide)s, etc., such polymers having excellent resistance to heat and mechanical properties.

Abstract: A process for producing polyimide microfine particles which is amenable to free control of particle morphology and particle diameter distribution is provided. A polyamic acid and a polyimide, each in the form of microfine particles with good monodispersibility, are also provided. There is also provided a process for producing polyimide microfine particles from a tetracarboxylic anhydride and a diamine compound which comprises (a) a first step of preparing a first solution containing the tetracarboxylic anhydride and a second solution containing the diamine compound, (b) a second step of mixing the first and second solutions and causing a polyamic acid to precipitate in the form of microfine particles from the mixed solution under ultrasonic agitation, and (c) a third step of imidating the polyamic acid particles to provide the objective polyimide in the form of microfine particles.

Abstract: The present invention is directed to polyimide systems which simultaneously offer low toxicity, a high glass transition temperature, excellent thermal oxidative stability, and desirable processing characteristics. These various polyimide systems include mixtures of monomeric reactants, polyimide-precursor reaction products, polyimides, and polyimide-containing articles. In one aspect of the invention, the mixture of monomeric reactants includes at least one dia-nhydride or a derivative thereof, and at least one diamine. The diamine may be 4,4′-[1,4-phenylene-bis(1-methylethylidene)]bisaniline, 4,4′-[1,3-phenylene-bis(1-methylethylidene)]bisaniline, and/or a derivative thereof. The diamine also may include a phenylenediamine, 2,2-bis[4-(4-aminophenoxyl)phenyl]propane, 4,4′(1,4-phenylene-bismethylene)bisaniline, and/or a derivative thereof. In addition, the mixture may include a reactive end-capping agent and/or a non-reactive end-capping agent.

Abstract: A polyimide precursor solid residuum is an admixture of an aromatic dianhydride or derivative thereof and an aromatic diamine or dervative thereof plus a complexing agent, which is complexed with the admixture by hydrogen bonding. The polyimide precursor solid residuum is effectively employed in the preparation of polyimide foam and the fabrication of polyimide foam structures.

Abstract: The present invention relates to a radiation-curable binder BM consisting of a copolymer which is composed of: A) from 80 to 99% by weight of a hydroxyl-containing polyether acrylate and/or polyester acrylate A), which optionally contains a mono-, di- and/or polyamine AA) as adduct, and of B) from 1 to 20% by weight of benzophenonetetracarboxylic acid, its anhydrides and/or its esters. The invention additionally relates to processes for the preparation of the binder BM and to the use of the binders BM in radiation-curable coating compositions.

Abstract: Polyimide copolymers were obtained containing 1,3-bis(3-aminophenoxy)benzene (APB) and other diamines and dianhydrides and terminating with the appropriate amount of a non-reactive endcapper, such as phthalic anhydride. Homopolymers containing only other diamines and dianhydrides which are not processable under conditions described previously can be made processable by incorporating various amounts of APB, depending on the chemical structures of the diamines and dianhydrides used. Polyimides that are more rigid in nature require more APB to impart processability than polyimides that are less rigid in nature. The copolymers that result from using APB to enhance processability have a unique combination of properties including: excellent thin film properties, low pressure processing (200 psi and below), improved toughness, improved solvent resistance, improved adhesive properties, improved composite mechanical properties, long term melt stability (several hours at 390 C.), and lower melt viscosities.

Abstract: The invention relates to a gas barrier composition as well as to composite structures having at least one surface of a molded resin coated with the composition, said composition comprising:(A) an alkoxysilyl functional polyamine compound, or a hydrolyzate thereof, said polyamine compound having three or more amine groups, at least one nitrogen atom of said amine groups being bonded to a hydrogen atom and at least one nitrogen of said amine groups being bonded to an alkoxysilyl group expressed by the formula--W--SiR.sup.2.sub.3-f (OR.sup.1).sub.fwherein R.sup.1 is an alkyl group having 1 to 6 carbon atoms, R.sup.

Abstract: The invention relates to a photosensitive polyimide resin composition comprising (A) a polyamic acid having, in its main chain, repeating units formed from a polycondensation product of at least one tetracarboxylic acid or tetracarboxylic anhydride thereof with at least one diamine compound, and having actinic ray-sensitive functional groups at both terminals thereof; (B) a photosensitive auxiliary having a photopolymerizable functional group; (C) a photopolymerization initiator; and (D) a solvent, wherein 1 the polyamic acid is such that when the repeating unit represented by the formula (1) is defined as a unit molecular weight, a unit molecular weight per carboxyl group (unit molecular weight/COOH) falls within a range of from 200 to 300, and 2 the photosensitive resin composition permits the formation of a polyimide film having a residual stress of 40 MPa or lower and a coefficient of thermal expansion of 30 ppm/.degree. C.

Abstract: The present invention is directed to oxidative and reductive methods of fabricating electrically conducting polymers and precursors thereof in particular polyanilines in which the polymer chains are deaggregated. Such deaggregated conducting polymers and precusors thereof exhibit better processability and higher electrical conductivity than do the corresponding aggregated polymers. Substituted and unsubstituted polyanilines in the substantially non oxidized or non reduced form (emeraldine form) are converted to an intermediate deaggregated reduced or oxidized form. The intermediate reduced or oxidized deaggregated form is processed into an article. The articles is subsequently treated with a dopant and an oxidizing or reducing agent to reform the original substantially non oxidized or non reduced form. The methods described herein permit the formation of articles such as shaped articles and films having deaggregated structure and higher electrical conductivity.

Abstract: A diamine which is useful in preparing a new flexible polyamide and polyimide with an aromatic dicarboxylic acid and a tetracarboxylic dianhydrides, respectively, has a general formula as follows: ##STR1## wherein R.sub.1 is methyl (--CH.sub.3) and n is an integer ranging from 1 to 4.

Abstract: A compound of the formula: ##STR1## wherein Ar.sup.

Abstract: Water soluble polyalkanolamides and a process to prepare same by reacting polycarboxylic acid or its anhydride, ester or halide derivative with at least one alkanolamine and optionally with a polyamine and removing the condensation byproduct water, alcohol or hydrogen halide.

Abstract: Polyimide copolymers were obtained containing 1,3-bis(3-aminophenoxy)benzene (APB) and other diamines and dianhydrides and terminating with the appropriate amount of reactive endcapper. The reactive endcappers studied include but should not be limited to 4-phenylethynyl phthalic anhydride (PEPA), 3-aminophenoxy-4'-phenylethynylbenzophenone (3-APEB), maleic anhydride (MA) and nadic anhydride (5-norbornene-2,3-dicarboxylic anhydride, NA). Homopolymers containing only other diamines and dianhydrides which are not processable under conditions described previously can be made processable by incorporating various amounts of APB, depending on the chemical structures of the diamines and dianhydrides used. By simply changing the ratio of APB to the other diamine in the polyimide backbone, a material with a unique combination of solubility, Tg, Tm, melt viscosity, toughness and elevated temperature mechanical properties can be prepared.

Abstract: A polyimide precursor solution having a high concentration yet low viscosity, a polyimide coating film having satisfactory physical properties which is prepared from the polyimide precursor solution, and a process for producing a polyimide coating film using the polyimide precursor solution. The polyimide precursor solution has dissolved therein a specific salt of a diamine and a tetracarboxylic acid and/or a dicarboxylic acid-dialkyl ester in a high concentration, the diamine and the tetracarboxylic acid and/or the dicarboxylic acid-dialkyl ester being capable of forming a polyimide. Also disclosed is a polyimide coating film obtained by heating the solution to cause imidization and a process for producing the polyimide coating film.

Abstract: A polyimide resin having good thermal stability and good adhesion to a metal foil is disclosed. The polyimide resin is prepared by dissolving at least one diamine in a polar aprotic solvent followed by the addition of an aromatic tetracarboxylic acid dianhydride to the solution of the aromatic diamines to prepare a polyamic acid solution, imidizing this solution to a polyimide resin by heating at a temperature above 250.degree. C., the polar aprotic solvent comprising at least 1 weight % of acetone. Polyimide laminates with a metal foil, such as a copper foil, are also described. The laminates may be used to form flexible printed circuit boards.

Abstract: Polyimide polymers from 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4,3',4'-benzophenonetetracarboxylic dianhydride and a diamine such as p-phenylenediamine exhibit a high glass transition temperature, high thermal oxidative stability and low moisture regain, useful for structural applications.

Abstract: High temperature resins containing phenylethynyl groups that are processable by transfer molding have been prepared. These phenylethynyl containing oligomers were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynlphthalic anhydride in glacial acetic acid to form a mixture of imide compounds in one step. This synthetic approach is advantageous since the products are a mixture of compounds and consequently exhibit a relatively low melting temperature. In addition, these materials exhibit low melt viscosities which are stable for several hours at 210-275.degree. C., and since the thermal reaction of the phenylethynyl group does not occur to any appreciable extent at temperatures below 300.degree. C., these materials have a broad processing window. Upon thermal cure at .about.300-350.degree. C., the phenylethynyl groups react to provide a crosslinked resin system.

Abstract: Poly(vinylamine)-based superabsorbent gels are disclosed. The superabsorbent gels either comprise a mixture of a poly(vinylamine) polymer and an acidic water-absorbing polymer, like polyacrylic acid, or comprise a salt of a poly(vinylamine) polymer. An improved method of preparing poly(vinylamine) also is disclosed.

Abstract: A fully imidized cresylic acid soluble polymer comprising 4,4'- oxydiphthalic anhydride (ODPA), 3,4,3',4',-biphenyltetracarboxylic dianhydride (BPDA), 3,4'-oxydianiline (ODA), and 4,4'-oxydianiline (DAPE) that can be used as a coating material such as a wire coated enamel. The polyimide has relatively low viscosity and high percent solids by substituting some of the 3,4'oxydianiline with 4,4'oxydianiline. Substitution with the 4,4'oxydianiline can be accomplished up to 25% on the molar basis without losing the fully imidized, cresol solubility characteristics.

Abstract: This invention relates to methods for preparing novel, solid-phase transfer reagents, specifically phosgenated oxime resins and non-symmetrical ureas, that are useful as supports in combinatorial synthesis for the creation of libraries of compounds for lead identification.

Abstract: The present invention relates to a dispersing agent for pigments or extenders which is obtainable by salt formation from an amine-functional compound by means of an acid,wherein a polyamine which contains at least three amino groups and which is from the group comprising aliphatic linear polyamines and/or aliphatic branched polyamines and/or modified polyamines, with the proviso that after modification three amino groups which can be converted into salts are still present per molecule, or a mixture of polyamines such as these, is used as the amine-functional compound, andwherein a substance from the group comprising phosphoric acid esters of general formula: (HO).sub.3-n PO(OR.sup.1).sub.n where n=1 or 2, sulphonic acids of general formula HOSO.sub.2 R.sup.2 and acidic sulphuric acid esters of general formula HOSO.sub.3 R.sup.2 is used as the acid, wherein R.sup.1 and R.sup.

Abstract: A diaminobenzene derivative represented by formula (1), and a polyimide obtained by reacting a diamine containing at least 1 mol % of said diaminobenzene derivative, with a tetracarboxylic acid and its derivatives to obtain a polyimide precursor and ring-closing it, having a repeating unit represented by formula (2), and a liquid crystal alignment film containing said polyimide. ##STR1## P is a single bond or --O--, --COO--, or --CONH--, Q is a cyclic substituent selected from an aromatic ring, an aliphatic ring, a hetero ring and their substitution products, R.sup.1 is an aliphatic ring, and R.sup.2 is C.sub.1-22 straight chain alkyl group, A is a tetravalent organic group constituting a tetracarboxylic acid, B is a bivalent organic group constituting a diamine.

Abstract: A cyclic amine containing polymer substantially free of primary and secondary amino groups which is prepared by reacting:a) an amine selected from the group consisting of:i) cyclic amines having at least one nitrogen atom in the ring and at least one primary amino alkyl group bonded to the nitrogen atom of the ring, andii) mixtures of cyclic amines containing at least two nitrogen atoms which react with a cross-linking agent with at least one other amine containing 1-6 nitrogen atoms which react with a cross-linking agent, withb) at least one cross-linker selected from the group consisting of at least one compound containing two groups which react with the primary amino group and said nitrogen atoms and mixtures of at least one compound containing two groups which react with the primary amino group and said nitrogen atoms with at least one compound containing at least three groups which react with the primary amino group and said nitrogen atoms in a molar ratio of (a):(b) of from 2.5:1 to 1:1.

Abstract: A method of producing a polyamide resin by reacting with at least one diamine compound, at least one linear polyester resin consisting of at least one dicarboxylic acid component and at least one diol component and having an intrinsic viscosity of not less than 0.2 dl/g, the at least one diamine compound being used in an amount of 0.5-1.5 mol per 1 mol of the at least one linear polyester resin as calculated in the repeating unit thereof, the linear polyester resin and the diamine compound being reacted in a reaction medium comprising at least one solvent selected from aprotic protophobic polar solvents, so that the at least one diol component of the linear polyester resin is substituted by the diamine compound, resulting in the polyamide resin as a reaction product.

Abstract: The polyimides are derived from solutions of at least one low-boiling organic solvent, e.g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80.degree. C. and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the ester-acids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

Abstract: A polyimide for optical communications has a monomer, represented by the formula (1), as a repeating unit: ##STR1## wherein X.sub.1 and X.sub.2 are independently selected from the group consisting of halogen atom, halogenated alkyl group, halogenated aromatic ring group, --NO.sub.2, --OR.sup.1 and --SR.sup.1 (where R.sup.1 is selected from the group consisting of halogenated alkyl and halogenated aromatic ring groups); and Z is selected from the group consisting of divalent halogenated aliphatic hydrocarbon, divalent halogenated aliphatic cyclic hydrocarbon and divalent halogenated aromatic hydrocarbon. Thus, light absorption loss at a near infrared light wavelength range can be minimized by using the polyimide, so that the polyimide is very useful as an optical material in the optical communications field using light of a near infrared light region.