Abstract: A process for preparing nitro substituted polyarylketones of the formula: ##STR1## is disclosed. The process involves the condensation of ##STR2## where R.sub.A is hydrogen, --COOH, or C.sup.1 to C.sub.12 linear or branched alkyl, Y and Y' are the same or different and are a chemical bond ##STR3## or --Si(CH.sub.3).sub.2 -- and m is 0 or 1 and X is halo. These nitro groups of these compounds can be reduced to provide the corresponding amines, which are useful for the preparation of thermally stable high melting polyimides.

Abstract: In humid atmospheres (e.g., 40% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyimides tend to be unstable in the sense that during spin coating operations undesirable precipitate formation occurs on the rotating surface of the wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyimide polymers in a solvent containing one or more liquid aromatic hydrocarbons having a boiling point at least about 110.degree. C. and one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C., such that the solution (a) contains on a weight basis from about 5% to about 50% of the polyimide, and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to about 55% relative humidity.

Abstract: In humid atmospheres (e.g., 55% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyamic acid polymers tend to be unstable in the sense that during spin coating operations undesirable precipitate formation may occur on the rotating surface of a semiconductor wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described is a method of spin coating solutions of these polyamic acid polymers in a solvent containing one or more cycloaliphatic ketones, such that the solution (a) contains on a weight basis from about 5% to about 40% of the polyamic acid and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to at least about 55% relative humidity.

Abstract: In humid atmospheres (e.g., 55% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis [4-(aminophenoxy)phenyl]hexafluoropropane polyamic acid polymers tend to be unstable in the sense that during spin coating operations undesirable precipitate formation may occur on the rotating surface of a semiconductor wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyamic acid polymers in a solvent containing at least 40% by weight of one or more liquid aromatic hydrocarbons having a boiling point of at least about 110.degree. C. and at least 5% by weight of one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C.

Abstract: In humid atmospheres (e.g., 40% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyimides tend to be unstable in the sense that during spin coating operations undesirable precipitate formation occurs on the rotating surface of the wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyimide polymers in a solvent containing one or more liquid aromatic hydrocarbons having a boiling point of at least about 110.degree. C. and one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C., such that the solution (a) contains on a weight basis from about 5% to about 50% of the polyimide, and (b) does not undergo precipitate formation during spin coating in an atmosphere of at least up to about 55% relative humidity.

Abstract: In human atmospheres (e.g., 55% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyamic acid polymers tend to be unstable in the sense that during spin coating operations undesirable precipitate formation may occur on the rotating surface of a semiconductor wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyamic acid polymers in a solvent containing one or more cycloaliphatic ketones, such that the solution (a) contains on a weight basis from about 5% to about 40% of the polyamic acid and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to at least about 55% relative humidity.

Abstract: In humid atmospheres (e.g., 40% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyimides tend to be unstable in the sense that during spin coating operations undesirable precipitate formation occurs on the rotating surface of the water. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are compositions especially adapted for use in spin coating wafers of semiconductive materials, which comprise solutions of these polyimide polymers in a solvent containing at least 10% of a cycloaliphatic ketone (e.g., cyclohexanone) or mixture of cycloaliphatic ketones, such that the solution (a) contains on a weight basis from about 5% to about 50% of the polyimide, and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to at least about 55% relative humidity.

Abstract: In humid atmospheres (e.g., 55% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyamic acid polymers tend to be unstable in the sense that during spin coating operations undesirable precipitate formation may occur on the rotating surface of a semiconductor wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyamic acid polymers in a solvent containing at least 40% by weight of one or more liquid aromatic hydrocarbons having a boiling point of at least about 110.degree. C. and at least 5% by weight of one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C.

Abstract: Described is a process for producing, in particulate form, aromatic polyimides based on one or more 2,2-bis[4-(aminophenoxy)-phenyl]hexafluoropropanes. The process involves forming, heating and agitating in a medium composed of dipolar aprotic solvent and liquid aromatic hydrocarbon solvent, a homogeneous solution of a polyamic acid derived from a substantially equimolar mixture of (i) an aromatic tetracarboxylic dianhydride and (ii) a 2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane, such that a separate phase of particulate aromatic polyimide is formed in such medium. The process avoids difficulties caused by the tendency of the wet polyimide polymer to agglomerate into stringy or tacky masses which can foul reactor and agitator surfaces.

Abstract: The reaction of alkali metal with aromatic hydroxy compounds is promoted by inclusion of an alcohol in the reaction mixture. The alkali metal aryloxide formed can be reacted with phosphonitrilic chloride polymers to make polyaryloxyphosphazenes.

Abstract: Moldable, thermoplastic resins formed by polymerization of nuclear brominated styrenes in the presence of a rubbery polymer. These resins have high heat deflection temperatures, high resistance to flammability as well as other desirable physical properties.

Abstract: Impact resistant polymers having low permeability to gases and vapors are prepared by polymerizing an olefinic nitrile such as acrylonitrile with an olefinic ester such as methyl acrylate in an aqueous medium in the presence of a diene rubber.