Abstract: A gas barrier polymer composition with active hydrogen functionality is provided. The polymer may be prepared by reacting a solution of organic diacid containing at least one active hydrogen group and diglycidyl ether in the presence of an optional catalyst. The pressure, temperature, and time parameters of the reaction are preferably regulated to prevent degradation and subsequent incorporation of degradation products of organic diacid containing at least one active hydrogen group into the gas barrier polymer composition. A formulation of the gas barrier polymer composition and a carrier may be used to coat plastic materials, containers, and preforms. The gas barrier polymer composition may also be employed in a method of making multilayer packaging materials or container preforms. The multilayer packaging materials or preforms can be used to make containers useful in packaging gas sensitive substances.

Abstract: A polyimide film, which is produced from polyamide acid prepared through the reaction of p-phenylenebis(trimellitic acid monoester anhydride), oxydiphthalic acid dianhydride, p-phenylenediamine, and 4,4′-diaminodiphenylether in an organic solvent, and which has a high elastic modulus, a high elongation, a low coefficient of linear expansion which is not quite different from that of copper, and a low coefficient of hygroscopic expansion.

Abstract: An object of the invention is to provide thermosetting amic acid microfine particles, thermosetting imide microfine particles and crosslinked imide microfine particles of controlled particle shape and size distribution. The invention provides a production technology which comprises mixing a first solution containing a tetracarboxylic anhydride and a C═C bond-containing acid anhydride with a second solution containing a diamine compound, causing precipitation of thermosetting amic acid microfine particles from the resulting mixture, and further producing thermosetting imide microfine particles and crosslinked imide microfine particles from the thermosetting amic acid microfine particles.

Abstract: The present invention provides a liquid crystal display element having an adequate pre-tilt angle for preventing the reverse domain, as well as excellent electrical properties by preparation of the polyamic acid composition for the liquid crystal display element which comprises a polyamic acid A that excels in electrical properties and a polyamic acid B that has side chains, mixed in the ratio A/B of 50/50 to 95/5 (by weight).

Abstract: A polymide useful as an adhesive for semiconductor assemblies having excellent thermal resistance and adhesive strength at high temperatures.

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: 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: 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: 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: 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 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: 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: 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: The present invention provides a method for producing a formed article from a dope comprising a polyphosphoric acid solvent and a polymer soluble in polyphosphoric acid, which includes using a production apparatus containing an apparatus for stirring and uniformly dispersing or homogenizing a dope and a pump apparatus for delivering the uniformly dispersed or homogeneous dope, wherein at least one of the apparatus and the pump apparatus has a part that comes into contact with the dope. According to the present invention, maintenance frequency of production facility due to the corrosion and elution of metal in a recovered solvent can be reduced, which in turn decreases the production cost.

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: Polymerisable resins which comprise a porphyrinogenic ring system obtained by the reaction of: (a) one or more compounds selected from the group consisting of pyrrole and N-(lower)alkyl pyrroles, any of which may be optionally substituted, and (b) a C4-C6 saturated alicyclic ketone which is capable of reacting with the 2 or 5 position of the pyrrole ring. Resin coating systems comprising the said resins.

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: 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: 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: 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 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: This invention relates to methods of preparing dibasic acids, such as adipic acid for example, by oxidizing a hydrocarbon with a gas containing an oxidant, preferably oxygen. A respective hydrocarbon is reacted with a gaseous oxidant to form dibasic acid in a mixture which preferably contains a solvent, a catalyst, and an initiator. The temperature of the mixture is then lowered to a point at which solid dibasic acid is precipitated, while maintaining a single liquid phase. At least part of the formed acid is then removed.

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: The level of anhydride linkages in copolyestercarbonates is decreased by preparing the copolyestercarbonate interfacially in a two-step method from at least one dihydroxyaromatic compound and at least one dicarboxylic acid. The first step is conducted at a pH in the range of about 4.5-9.5, employing the combination of a phase transfer catalyst such as a tetraalkylammonium halide and a tertiary amine such as triethylamine. The proportion of the phase transfer catalyst is in the range of about 3-12 mole percent based on total dihydroxyaromatic compound and dicarboxylic acid employed. In the second phosgenation step, the pH is raised to at least 10 and a stoichiometric phosgene excess of at least 5% is introduced.

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: 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: 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 process has been surprisingly discovered that can produce a high heat carbonate polymer (i.e., one with a Tg greater that 150.degree. C.), without the drawbacks encountered in attempts to produce a high heat carbonate polymer. The process of the instant invention comprises the steps of:(1) reacting an aromatic amine with a dihydric phenol to prepare an aminophenol;(2) reacting an anhydride or dianhydride with the aminophenol to prepare a phenolic precursor; and(3) reacting the phenolic precursor with a carbonate precursor to prepare a high heat carbonate polymer.

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

Abstract: The new diamine, "3,3',5,5'-tetramethyl-2,2-bis[4-(4-amino-phenoxy)phenyl]propane" was synthesized and used to prepare high performance soluble engineering plastics by polycondensation. The polymer can be polyamides, polyimides or poly(amide-imide)s. These polymers exhibit excellent solubility, processability, heat resistance and mechanical performance.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3##

Abstract: Electronic parts and a process for manufacturing the electronic parts are provided. The electronic parts comprise an electric insulating material exhibiting a high heat resistance and low dielectric constant as a structural component. The electric insulating material is formed of a polyimide containing a recurring unit represented by the following general formula (1).

Abstract: A diamine-containing polyamic acid alignment layer material provided by the polymerization of aromatic diamine and dianhydride, and having an excellent coating, adhesion and stability. After the polyamic acid alignment layer material is coated and cured at a high temperature, a polyamic acid alignment layer having a pretilt angle of below 2 degrees is formed due to a close ring reaction. The polyamic acid alignment layer with a low pretilt angle can be used in a TN (twisted nematic) type liquid crystal display.

Abstract: Polyimide is produced by reacting two kinds of diamine compounds consisting of diaminopolysiloxane and a hydroxyl group-containing diamine or three kinds of diamine compounds consisting of diaminopolysiloxane, a hydroxyl group-containing diamine and an aromatic or alicyclic diamine with a dicarboxylic acid anhydride having a 2,5-dioxotetrahydrofuryl group as one acid anhydride group, thereby once forming a polyamic acid, and subjecting the polyamic acid to polyimidization reaction. The resulting polyimide itself is soluble in low boiling organic solvents for general purpose use, typically methyl ethyl ketone. A photosensitive composition comprising the polyimide, a photo crosslinking agent and a photo acid-generating agent forms a negative type polyimide pattern upon development with an aqueous alkali solution.

Abstract: This invention relates the novel diamines, the polyimide oligomers and the polyimides derived therefrom and to the method of preparing the diamines, oligomers and the polyimides. The thermoplastic polyimides derived from the aromatic diamines of this invention are characterized as having a high glass transition temperature, good mechanical properties and improved processability in the manufacture of adhesives, electronic and composite materials for use in the automotive and aerospace industry. The distinction of the novel aromatic diamines of this invention is the 2,2',6,6'-substituted biphenyl radicals which exhibit noncoplanar conformation that enhances the solubility of the diamine as well as the processability of the polyimides, while retaining a relatively high glass transition temperature and improved mechanical properties at useful temperature ranges.

Abstract: Disclosed is a method of making an imide-containing polymer by bulk or melt polymerizing monomers. A mixture is formed of (1) a cyclic compound that contains an anhydride group and a second group which is an anhydride, a carboxylic acid, or an ester and (2) a diamine in an amount stoichiometric .+-.5 mole % of stoichiometric with the amount of cyclic compound. An end capper may also be included in the mixture to control the molecular weight but no solvent is used. A polyimidesiloxane can be made by using a siloxane-containing diamine. The mixture is heated to a temperature above the T.sub.g or T.sub.m of the polymer but below its degradation temperature.

Abstract: The invention herein relates to a novel soluble polyimide resin comprising polyalicyclic structures and the process of preparation of the same, wherein aromatic tetracarboxylic dianhydride and novel aromatic diamine having an polyalicyclic group with various structures are used to yield a novel form of a polyimide resin, which has superior heat-resistance, solubility, and transparency.More specifically, the invention herein relates to a novel polyimide resin having excellent heat-resistance and solubility, which is prepared by means of reacting diamine monomers having a novel chemical structure with various types of aromatic carboxilic dianhydrides, in stead of aromatic diamine used for the preparation of the conventional polyimide resin. As a result, the polymers so obtained had the glass transition temperature of 260.degree. C..about.410.degree. C. and showed a increase in solubility in proportion to the increase in a number of the aromatic rings between two phenyl groups.

Abstract: Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. Alternatively, these copolyimides may be prepared by reacting 4,4'-oxydiphthalic anhydride with 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydiisocyanate. Also, the copolyimide may be prepared by reacting the corresponding tetra acid and ester precursors of 4,4'-oxydiphthalic anhydride and 3,4,3',4'-biphenyltetracarboxylic dianhydride with 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

Abstract: The invention herein relates to a soluble polyimide resin for a liquid crystal alignment layer and the manufacturing method thereof, wherein a mixture of aliphatic tetracarboxylic acid dianhydrides and aromatic diamine having aliphatic side chains are used to yield a soluble polyimide resin which has superior heat-resistance, solubility, surface hardness, transparency and liquid crystal alignment capacity.The soluble polyimide resin having alkoxy substituents, for a liquid crystal layer, according to the present invention, is manufactured by adding a mixture of dioxotetrahydrofuran 3-methylcyclohexene-1,2-dicarboxylic dianhydride, which is an aliphatic tetracarboxylic acid dianhydride and aromatic tetracarboxylic acid dianhydride to a mixture of aromatic diamine, and said dioxotetrahydrofuran 3-methylcyclohexene- 1,2-dicarboxylic dianhydride is used in the amount of 50 to 99 mol % to the total amount of anhydrides.

Abstract: Fluorinated polymides comprising units of 2,2',5,5',6,6'-hexafluorobiphenyl-3,3',4,4'-tetracarboxylic dianhydride and aromatic diamines.

Abstract: This invention relates the novel diamines, the polyimide oligomers and the polyimides derived therefrom and to the method of preparing the diamines, oligomers and the polyimides. The thermoplastic polyimides derived from the aromatic diamines of this invention are characterized as having a high glass transition temperature, good mechanical properties and improved processability in the manufacture of adhesives, electronic and composite materials for use in the automotive and aerospace industry. The distinction of the novel aromatic diamines of this invention is the 2,2',6,6'-substituted biphenyl radicals which exhibit noncoplanar conformation that enhances the solubility of the diamine as well as the processability of the polyimides, while retaining a realatively high glass transition temperature and improved mechanical properties at useful temperature ranges.

Abstract: The invention herein relates to a soluble polyimide resin and the process of preparation of the same, wherein aromatic tetracarboxylic dianhydride and aromatic diamine having an alicyclic group with various structures of substituted alkyl groups are used to yield a novel form of a polyimide resin, which has superior heat-resistance, solubility and transparency.More specifically, the invention herein relates to a novel polyimide resin having excellent heat-resistance and solubility, which is prepared by means of reacting aromatic diamine monomers having a novel chemical structure with various types of aromatic tetracarboxilic acid dianhydrides, in stead of aromatic diamine used for the preparation of the conventional polyimide resin. As a result, the polymers so obtained had the glass transition temperature of 250.degree. C..about.400.degree. C. and showed a increase in solubility in proportion to the increase in volume of the alkyl group.

Abstract: A bis(trisubstitutedtrimellitic anhydride) derivative and a polyesterimide for optical communications, the polyesterimide being formed therefrom. The polyesterimide has a high refractive index, so that when using such polyesterimide as a material for a core of an optical fiber, the range of materials that can be selected for the cladding becomes wide. Also, a coating property and adhesion to a substrate are improved, thereby providing a good film forming property and thermal stability. Also, because the polyesterimide can minimize optical loss at a near infrared wavelength range, the polyesterimide is very useful as an optical material in the optical communications field adopting the light of near infrared wavelength.

Abstract: The invention herein relates to a soluble polyimide resin for a liquid crystal alignment layer and the process of preparation of the same, wherein aliphatic tetracarboxylic dianhydride and aromatic diamine having the amide group are used to yield a novel form of a polyimide resin having superior heat-resistance, solubility, transparency, and liquid crystal alignment capacity.More specifically, the invention herein relates to a novel polyimide resin having excellent heat-resistance, solubility, liquid crystal alignment property, and high pretilt angle, which is prepared by means of jointly using the aromatic diamine, used for the preparation of the conventional polyimide resin, and the aromatic diamine having a long alkyl chain with a substituted amide group, and reacting the same with various types of carboxylic dianhydride.

Abstract: The invention relates to a silicon-containing polyimide resin comprising (I) 0.1 to 100 mole % of structural units represented by the formula: ##STR1## where Ar.sup.1 is a tetra valent organic group having at least one aromatic ring, R independently represents a monovalent hydrocarbon group free of aliphatic unsaturated bonds, X is selected from an alkyleneoxyalkylene or an alkylene group having 2 or more carbon atoms, Y is an oxygen atom, an alkyleneoxyalkylene group, or an alkylene group having 2 or more carbon atoms, l, m, n are each integers having a value of 1 to 10, p is an integer having a value of 1 to 80, and a is 0 or 1; and (II) 99.9 to 0 mole % of structural units represented by the formula: ##STR2## where Ar.sup.2 is a tetravalent organic group having at least one aromatic ring, and Ar.sup.3 is a divalent organic group having at least one aromatic group.

Abstract: Methods and devices for controlling the oxidation of a hydrocarbon to an acid by regulating the temperature hold-up time, and conversion in consecutive reaction zones. The temperature in the consecutive reaction zones progressively decreases, while the hold-up time increases. Preferably, the conversion also increases. One of the major advantages of the methods and devices of the present invention is that an outstanding balance between productivity and selectivity/yield of the desired acid may be achieved. In this respect high yields and selectivities may be obtained without sacrificing productivity.