Abstract: The polyamic acid of the invention can be obtained by the reaction of an acid anhydride component comprising pyromellitic anhydride and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane with 2,2′-di-substituted-4,4′-diaminobiphenyls as a first aromatic diamine and any aromatic diamine component, as a second aromatic diamine, of 2,2-bis(4-aminophenoxyphenyl)propanes, 1,1-bis(4-(4-aminophenoxy)-3-t-butyl-6-methylphenyl)butane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane and &agr;,&agr;′-bis(4-aminophenyl)diisopropylbenzenes in an organic solvent. The polyimide resin of the invention can be obtained by heating such a polyamic acid solution. In the production of a circuit board, by using a photosensitive polyamic acid having a sensitizer incorporated in such a polyamic acid solution, a patterned polyimide resin layer can be provided as an insulation layer on a metal foil.

Abstract: Aromatic polyamide fibers which have a crystalline structure having (1) crystal size (A) in a (110) plane of 7.5 nm, (2) crystal size (B) in a (200) plane of 8.2 nm and (3) a product A×B of 61.50 to 630.00, and exhibit a thermal linear expansion coefficient of −1.0×10−6/° C. to −7.5×10−6/° C. and thus a high dimensional stability even upon moisture-absorbing and desorbing, are useful for forming a resin-reinforcing fiber sheet, a pre-preg containing the fiber sheet, and a laminate for, for example, an electric insulating material or electric circuit board, having an excellent cutting, shaving, perforating or laser processability and capable of forming a smooth cut, shaved or perforated face.

Abstract: Heat resistant polybenzoxazole resins useful as layer insulation films and protective films for semiconductor, layer insulation films for multilayer circuits, cover coats for flexible copper-clad sheets, solder resist films, liquid crystal-aligned films and the like. These resins have excellent thermal, electrical, physical and mechanical characteristics. Polybenzoxazole precursors are provided, represented by the general formula (A), and are used to obtain polybenzoxazole resins, represented by the general formula (D). In the formulas (A) and (D), n denotes an integer from 2-1000, and X denotes a structure having a formula selected from structures indicated at (B). In the formulas at (B), Y denotes a structure having a formula selected from those indicated at (C), and the hydrogen atom(s) on the benzene ring in these structures are optionally substituted.

Abstract: A biaxially oriented film made from a wholly aromatic polyamide produced by an acid chloride process, which contains at least one member of inorganic particles having an average particle diameter of 5 to 2,000 nm and selected from the group consisting of hydroxides, carbonates and bicarbonates of metals of groups Ia and IIa of the periodic table. The inorganic particles is derived from inorganic particles which are added as a neutralizing agent to a reaction system to neutralize hydrogen chloride by-produced by the acid chloride reaction and its content corresponds to an excess portion added to the reaction system over the amount required for neutralizing the hydrogen chloride stoichiometrically. The film is useful as a base film for a magnetic recording medium, such as a coated, a multi-layer coated, or a thin metal film high-density magnetic recording medium.

Abstract: A method for producing polybenzazole in the presence of iron(II) ion. The polybenzazole obtained by this method can be formed into a highly strong fiber having a high elastic modulus and a heat resistant film. The method enables economical production of polybenzazole having fine tone and high polymerization degree.

Abstract: A method for producing polyamides, and to a method for producing primary polycondensates which are intermediates for polyamide production. More precisely, the invention relates to a method for producing primary polycondensates, which comprises a step of polycondensing a dicarboxylic acid component having a terephthalic acid content of from 60 to 100 mol % and a diamine component in which the amount of 1,9-nonanediamine and/or 2-methyl-1,8-octanediamine falls between 60 and 100 mol %, in the presence of water of being from 15 to 35% by weight, at a reaction temperature falling between 250.degree. C. and 280.degree. C. and under a reaction pressure (P) that satisfies the following formula (1):P.sub.0 .gtoreq.P.gtoreq.0.7 P.sub.0 (1)where P.sub.

Abstract: The present invention discloses polymers of poly(p-dioxanone having an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. This invention also describes improved surgical devices and filaments made from poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. Additionally, disclosed are processes for manufacturing poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C., as well as, processes for molding surgical articles and extruding surgical filaments from these polymers.

Abstract: It has been found that fibers which incorporate very good mechanical properties as well as very good adhesive properties can be made from an optically anisotropic spinning solution containing a mixture of a paraphenylene groups-containing, wholly aromatic polyamide component and another polyamide component if for the para-aromatic polyamide component full or partial use is made of copolymer in which 2,6-naphthylene units are present in addition to the paraphenylene units and the other polyamide component is an aliphatic polyamide. Preferably, the weight ratio of the para-aromatic polyamide component to the aliphatic polyamide component is 95:5 to 85:15. The aromatic copolyamide containing paraphenylene and 2,6-naphthylene is preferably obtained by polymerising paraphenylene diamine (PPD) and a stoichiometric amount of a mixture composed of terephthalic acid dichloride (TDC) and 2,6-naphthylene carboxylic acid dichloride (NDC) in a molar ratio TDC:NDC of 99:1 to 80:20.

Abstract: A class of rigid rod and latter polymers having light emitting capability is provided. Included in this class of polymers are those having novel repeating structural units. These rigid rod and ladder polymers are employed in light emitting diodes.

Abstract: The invention relates to poly(tertiary di- or polyarylamines) which have more than one aryl moiety which is further substituted with a moiety capable of chain extension or crosslinking. In another aspect, the invention relates to poly(tertiary di- or polyarylamines) which have more than one aryl moiety which is further substituted with a moiety capable of chain extension or crosslinking which are partially or completely crosslinked or chain extended. The invention further relates to films prepared from such chain extended or crosslinked poly(tertiary di- or polyarylamines). The invention further relates to electrophotographic devices and electroluminescent devices, such as polymeric light-emitting diodes, containing such films.

Abstract: A new class of polyarylene co-polymers include repeating units comprising one or more arylene units having the general formula (--Ar--/--Y--).sub.n, where Y is a divalent group chosen from nil, --Z--, --Z--Ph--, and --Ph--Z--Ph--, where Z is a divalent group chosen from the group consisting of --O--, --S--, --NR--, --O(CO)--, --O(CO.sub.2)--,--(CO)NH(CO)--, --NR(CO)--, phthalimide, pyromellitimide, --CO--, --SO--, --SO.sub.2 --, --P(O)R--, --CH.sub.2 --, --CF.sub.2 --, and --CRR'--; Ph is phenylene (ortho, meta or para); and n is greater than 4. The co-polymers are useful as molding resins, and composite matrix resins, and where Ar is heteroarylene as ion exchange resins.

Abstract: There are disclosed a para-aramid shaped article having a density of 1.390-1.470/cm.sup.3. The para-aramid has an inherent viscosity .eta.inh of at least 3.5 and contains metal ions of 500 ppm or less, the metal ions being combined with acid end groups linked with the para-aramid molecules. The invention also relates to a process for preparing the same. Due to a reduced rate of moisture sorption, a reduced hygroscopic expansion coefficient and excellent mechanical properties, the para-aramid of the present shaped article is suitable for use for reinforcing fiber materials for a composite material and for a magnetic recording medium.

Abstract: The present invention discloses polymers of poly(p-dioxanone having an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. This invention also describes improved surgical devices and filaments made from poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. Additionally, disclosed are processes for manufacturing poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C., as well as, processes for molding surgical articles and extruding surgical filaments from these polymers.

Abstract: Liquid crystalline polymers that are made from 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, terephthalic acid, hydroquinone, and N-acetyl-4-aminophenol by heating the monomers in the presence of acetic anhydride are more easily synthesized in high molecular weight if isophthalic acid is also included as a monomer at a level of about 0.5 mole % to about 10 mole %.

Abstract: A method for producing poly-o-hydroxy amides by conversion of an activated dicarboxylic acid derivative with a bis-o-aminophenol. A solution of the activated dicarboxylic acid derivative is added to a solution of the bis-o-aminophenol in a lactone, and a tertiary amine is added to the resulting mixture, wherein the lactone has the following structure: ##STR1## where A is--(CR.sup.1 R.sup.2).sub.m --or--(CR.sup.3 R.sup.4).sub.n --NR.sup.5 --,R.sup.1 to R.sup.5 are independent of one anotherR.sup.1 and R.sup.2 are hydrogen, alkyl with 1 to 7 carbon atoms (linear or branched), --CO(CH.sub.2).sub.p CH.sub.3, or --COO(CH.sub.2).sub.p CH.sub.3, with p=0 or 1,R.sup.3 and R.sup.4 are hydrogen or alkyl with 1 to 3 carbon atoms (linear or branched),R.sup.5 is hydrogen or methyl,m is a whole number from 2 to 11, andn is a whole number from 1 to 3.

Abstract: The present invention is directed to an aromatic polyamide of formula (I), ##STR1## an optical anisotropic dope containing the aromatic polyamide and a process of making the optical anisotropic dope which does not require sulfuric acid. R is an unsubstituted aromatic group or an aromatic group having at least one nitrile group substituted on the aromatic nucleus, with the proviso that at least 25 mol % of R in the aromatic polyamide is an aromatic group having at least one nitrile group substituted on the aromatic nucleus; R' is phenyl, naphthyl or diphenyl, which is unsubstituted or substituted with Cl, Br, I, NO.sub.2, an alkyl group having one to four carbon atoms or an alkoxy group having one to four carbon atoms; and n is an integer between 10 and 100,000.

Abstract: Rigid-rod and segmented rigid-rod polymers, methods for preparing the polymers and useful articles incorporating the polymers are provided. The polymers incorporate rigid-rod backbones with pendant solubilizing groups attached thereto for rendering the polymers soluble.

Abstract: A process for producing precondensates of partially crystalline or amorphous, thermoplastically processable, partially aromatic polyamides or copolyamides, and the use of the higher molecular weight of polyamides, accessible from the precondensates, for producing molding compositions, which are further processable by means of suitable processing techniques, involves the control of temperature and water vapor partial pressure, in a batch process.

Abstract: Aramids which after drawing have high tensile strengths and tensile moduli are made from units derived from selected 2,2'-disubstituted-4,4'-diaminobiphenyls, p-phenylenediamine, oxydianiline and terephthalic acid. Also disclosed is a process for drawing such aramids at least 1.5%, which results in the drawn aramid having significant crystallinity and higher tensile strength. The aramids are useful for ropes and composites.

Abstract: Shaped articles are obtained from a polymerization mixture of soluble wholly aromatic polyamides in a gel state.

Abstract: A process for the continuous production of polyamides from a mixture of at least one lactam and water and, if required, other monomer units and/or conventional additives and fillers under polyamide-forming conditions, where the mixture of the starting materials is heated in liquid phase in a first reaction zone until a conversion of at least 70% is reached, and undergoes adiabatic decompression and further polymerization in another reaction zone, wherein, in the first reaction zone, 0.5-7% by weight of water are employed, the temperature is increased to the range from 220.degree. to 310.degree. C., and polymerization is carried out until a conversion of at least 85% is reached and, in the second reaction zone, after the decompression further polymerization is carried out in the range from 215.degree. to 300.degree. C. without heat input.

Abstract: A polyamide (9-T polyamide) comprising (a) 60 to 100 mole of terephthalic acid and (b) a diamine component comprising 60 to 100 mole % of 1,9-nonanediamine, said polyamide having an intrinsic viscosity ?.eta.! as determined by measurement in concentrated sulfuric acid at 30.degree. C. of 0.6 to 2.0 dl/g and having at least 10% of terminal groups thereof blocked. Another polyamide (9M-T polyamide) comprises a dicarboxylic acid component (a) comprising 60 to 100 mole % of terephthalic acid and a diamine component (b) comprising 60 to 100 mole % of 1,9-nonanediamine and 2-methyl-1,8octanediamine, the molar ratio between said 1,9 nonanediamine and said 2-methyl-1,8-octanediamine being in a range of 60:40 to 99:1, said polyamide having an intrinsic viscosity ?.eta.! as determined by measurement in concentrated sulfuric acid at 30.degree. C. of 0.4 to 3.0 dl/g.

Abstract: A new class of polymers include repeating units comprising one or more arylene units substituted with heterocyclic side groups. The heterocyclic substituted arylene repeat units have the general structural formula: ##STR1## wherein Het is a heterocyclic group, R is an optional substituent, x is 1 or 2, and y is less than or equal to 4-x.

Abstract: High-performance polymers having a rigid-rod backbone comprising a chain length of at least 25 organic monomer units joined together by covalent bonds wherein at least about 95% of the bonds are substantially parallel; and solubilizing organic groups attached to at least 1% of the monomer units. The polymers are prepared in a solvent system which is a solvent for both the monomer starting materials and the rigid-rod polymer product.

Abstract: A process for producing an aromatic polyamide film comprising forming a thin layer of an optically isotropic dope in which an aromatic polyamide is dissolved in a polar amide, immersing the thin layer dope in a polar solvent kept at a temperature not higher than -20.degree. C. to coagulate the dope to form a film and drying the film in the presence of an isocyanate compound. Said process can produce directly a transparent film from an aromatic polyamide dope without requiring the step of dissolving the aromatic polyamide in conc. sulfuric acid, does not require any acid resistant equipment and is inexpensive.

Abstract: The present invention is directed to a process for preparing a polymeric amide which comprises the steps of:(A) reacting a mixture of (i) functionalized hydrocarbon polymer containing ester functional groups comprising at least one member selected from the group consisting of substituted alkyl ester functional groups, the substituted alkyl moiety containing at least one electron withdrawing substituent group, and aryl ester functional groups, the hydrocarbon polymer having a number average molecular weight of at least about 500 prior to functionalization, and (ii) an amine having at least one reactive --NH.sub.2 moiety, for a time and under conditions sufficient to form amide groups; and(B) removing from the mixture during step (A) hydroxyl compound released from the ester functional groups in forming the amide groups.The polymeric amides so produced are useful as fuel additives (e.g., detergents) and lubricating oil additives (e.g., dispersants).

Abstract: Wholly aromatic polyamides and their shaped articles containing at least 85 mole percent of repeat units of m-phenylene isophthalamide: ##STR1## and repeat units of selected aromatic diamines and diacid chlorides exhibit improved flame resistance while retaining good thermal stability.

Abstract: The present invention discloses polymers of poly(p-dioxanone having an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. This invention also describes improved surgical devices and filaments made from poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C. Additionally, disclosed are processes for manufacturing poly(p-dioxanone) with an inherent viscosity in the range of from 2.3 dL/g to about 8 dL/g, as determined at a concentration of 0.1 g/dL in hexafluoroisopropanol at 25.degree. C., as well as, processes for molding surgical articles and extruding surgical filaments from these polymers.

Abstract: A nonlinear optical material composed of a polyimide obtained from a diamine and/or a diacid anhydride or dithioacid anhydride substituted by a portion having a nonlinear optical effect or of molecules having a benzocyclobutene structure substituted at the portions having an nonlinear linear optical effect.

Abstract: A class of rigid rod and latter polymers having light emitting capability is provided. Included in this class of polymers are those having novel repeating structural units. These rigid rod and ladder polymers are employed in light emitting diodes.

Abstract: A process for producing an aromatic polyamide film, which comprises the steps of: (a) forming a thin layer of an optically isotropic dope in which an aromatic polyamide is dissolved in a polar amide, (b) immersing the thin layer dope of aromatic polyamide in a polar solvent, other than said polar amide, kept at a temperature not higher than -20.degree. C. to prepare a film, and (c) drying the film. The aromatic polyamide film thus obtained is excellent in transparency. Said process requires neither a step of dissolving an aromatic polyamide in conc. sulfuric acid nor an acid-resistant equipment, and hence, is inexpensive.

Abstract: A class of soluble polymers having a rigid rod backbone, which when used to cast films, undergo a self-orientation process whereby the polymer backbone becomes more or less aligned parallel to the film surface. This in-plane orientation results in a film that displays negative birefringence. The degree of in-plane orientation and thus, the magnitude of the negative birefringence is controlled by varying the backbone linearity and rigidity of the class of polymers which includes polyesters, polyamides, poly(amide-imides) and poly(ester-imides) through selection of substituents in the polymer backbone chain. By increasing the polymer backbone linearity and rigidity, the degree of in-plane orientation and associated negative birefringence can be increased, and that conversely, by decreasing the polymer backbone linearity and rigidity, the negative birefringence can be decreased.

Abstract: High-performance polymers having a rigid-rod backbone comprising a chain length of at least 25 organic monomer units joined together by covalent bonds wherein at least about 95% of the bonds are substantially parallel; and solubilizing organic groups attached to at least 1% of the monomer units. The polymers are prepared in a solvent system which is a solvent for both the monomer starting materials and the rigid-rod polymer product.

Abstract: Aromatic polyamide compositions with improved electrostatic properties, formed structures produced therefrom, and use and production thereof.Described are compositions comprising an aromatic polyamide which is soluble in organic solvents and from 0.01 to 30% by weight, based on the weight of the composition, of an organic or organometallic charge control agent.The compositions can be used for producing formed structures, in particular fibers; these fibers are preferably used for producing webs which can be used for producing dust filters.

Abstract: A process for preparing condensation polymers comprises forming a dispersion of a reaction mixture in a continuous vapor phase, maintaining the dispersion while passing it through a reaction zone, heating the dispersion in the reaction zone to polymerize reactants in the reaction mixture and form a polycondensate.

Abstract: Aramid polymers with small amounts of alkyl- and/or alkoxy-substitution on their aromatic diamine and/or aromatic diacid monomeric units are disclosed. Such aramid polymers show improved properties compared to similar aramids without the substitution. The aramids described herein are useful for films or fibers, for example, as employed in the manufacture of packaging, ropes, filter bags, or composites. The invention also includes a process for making such polymers, involving subjecting fibers or films made from such aramid polymers to heat treatment under tension.

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 process for preparing polyamideimide resins having high molecular weights as described wherein major problems of prior art processes such as low heat resistance and low melt flowability are improved. Polyamideimide resins having an intrinsic viscosity of 0.4 to 1.50 dl/g as measured on a solution of dimethylacetamide as a solvent at a concentration of 0.5 g/dl at 30.degree. C., are prepared by reacting an aromatic tricarboxylic acid anhydride with an aromatic diamine in N-methyl pyrrolidone solvent in the presence of a first catalyst selected from a group consisting of thionyl chloride, p-toluenesulphonly chloride, sulfuryl chloride, cyanuric chloride and phosphorus trichloride at a temperature of 50.degree. C. to 130.degree. C. over a period of 1 to 5 hours and further reacting the resultant reaction mixture in the presence of a second catalyst which is a compound of the formula (RO).sub.

Abstract: A copolymer having repeating units of the formula: ##STR1## wherein R is selected from the group consisting of --H, --CH.sub.3, --N(CH.sub.3).sub.2 and --OH, x has a value of 0.01 to 0.99 and Q is ##STR2## wherein X is --S-- or --O--.

Abstract: Alcohol-soluble aromatic heterocyclic polymers and copolymers having repeating units of the formulae I or II: ##STR1## wherein Q is a benzobisazole of the formula: ##STR2## wherein X is --O-- or --S--; wherein x has a value of 0.0 to 1.00 and y has a value of 0.05 to 1.00, and R is selected from the group consisting of: ##STR3## and R' is selected from the group consisting of alkyl having 1 to 5 carbon atoms, alkaryl having 7 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms and substituted aromatic having 1 to 3 substituent groups. The alcohol-soluble polymers and copolymers may be used for fabricating organic/inorganic hybrid composites with metal alkoxides M(OZ).sub.v, wherein M is Si, Ti, Al or the like and Z is a lower alkyl group. These polymers and copolymers can also be used to coat materials or substrates which are susceptible to attack by highly corrosive acids.

Abstract: Thermoplastically processable aromatic polyether amideThermoplastically processable aromatic polyether amide of the formula (I) ##STR1## in which the symbols Ar, Ar', Ar.sub.1, Ar.sub.2, R, R', Y, x, y and z have the following meanings:Ar is a divalent, substituted or unsubstituted, aromatic or heteroaromatic radical or a group--Ar*--Q--Ar*--in whichQ is a bond or an --O--, --C(CH.sub.3).sub.2, --CO--, --S--, --SO-- or --SO.sub.2 -- bridge and Ar* is an aromatic radical. The carbonyl groups of the Ar radical are on non-adjacent ring carbon atoms.A is up to three different radicals.Ar' has the meaning given for Ar or is an Ar--Z--Ar group.In this case, Z is a --C(CH.sub.3).sub.2 -- or --O--Ar*--O--bridge.Y is a --C(CH.sub.3).sub.2 --, --SO.sub.2 --, --S-- or a --C(CF.sub.3).sub.2 --bridge and has up to two different meanings in the same polymer.Ar.sub.1 and Ar.sub.2 are identical or different from one another and are each a substituted or unsubstituted para- or meta-arylene radical.

Abstract: A polyimide varnish which is a solution having a polyimide and/or a polyimide precursor dissolved in an organic solvent and which is useful for forming a polyimide coating film on a substrate by coating the solution on the substrate followed by heat treatment, wherein from 5 wt % to 60 wt % of the organic solvent is a lactic acid derivative of the formula (I): ##STR1## wherein each of R.sup.1 and R.sup.2 which are independent of each other, is hydrogen, a C.sub.1-5 alkyl group or a C.sub.1-5 alkenyl group.

Abstract: A process is described for preparing directly spinnable polymer solutions containing as fiber-forming substance polymers containing at least 95 mol %, based on the polymer, of the recurring structural unit of the formula I[--CO--R.sup.1 --CO--NH--R.sup.2 --NH--] (I)and up to 5 mol % of structural units as formed in the conversion/reaction of aromatic, aliphatic or cycloaliphatic dicarbonyl dichlorides and/or diamines. R.sup.1 and R.sup.2 are independently of each other 1,6-naphthylene, 1,7-naphthylene, 2,7-naphthylene, 3,4'-biphenyldiyl or 1,3-phenylene. The polymers prepared by reacting diamines of the formula (II) with dicarbonyl dichlorides of the formula (III) in solutionH.sub.2 N--R.sup.2 --NH.sub.2 (II)ClOC--R.sup.1 --COCl (III)The process contains the steps ofa) presenting the diamines as initial charge in the form of a solution in N-methylpyrrolidone,b) adding the dicarbonyl dichlorides to this solution,c) using starting monomers having a purity of greater than 99.

Abstract: Mixtures of salts of organic carboxylic acids and organic compounds of non-salt character, dissolved in a C.sub.1 -C.sub.4 alkanol, can be concentrated or separated with a semipermeable membrane made from a copolyamide or copolyimide-amide which contains (a) a first aromatic diamine radical and (b) a second aromatic diamine radical which carries --SO.sub.3 M groups, where M is H.sup..sym., a monovalent to polyvalent metal cation or an ammonium cation. Provided the first diamine radical contains C.sub.1 -C.sub.4 alkyl groups in the o-positions to the amino groups, the copolymers are radiation-sensitive and can be used for producing protective layers or relief images, development being carded out in an aqueous alkaline medium.

Abstract: A structural panel for a vehicle or building contains a substrate and a layer of flame resistant polybenzazole polymer. If the substrate is heat resistant, the panel can serve as a fire barrier. If the substrate is not heat resistant, the polybenzazole layer can still serve to delay ignition and contain any volatile gases and molten polymer that forms when the panel is subjected to heat.

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: Aramids having repeat units derived from p-phenylenediamine, 4,4'-bis(3-aminophenoxy)biphenyl and terephthalic acid. These aramids have good strength properties, particularly after drawing, and good high temperature properties. The aramids are useful for fibers and films.

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: Use of fluorinated aromatic polyamides as orientation layer for liquid crystal switching and display devicesUse of substituted aromatic polyamides as orientation layer in liquid crystal switching and display elements is described, in which the polyamides contain structural units of the formula (I) ##STR1## in which in formula I the symbols have the following meaning: ##STR2## in which R.sup.1 and R.sup.2 are identical or different and are perfluorinated alkyl having 1 to 4 carbon atoms, R.sup.3 and R.sup.4 are identical or different and are H or CF.sub.3, and in which --W-- is, for example, --O--, --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 --.Orientation layers made of these polyamides can be cured at low temperatures, have good adhesion and high transmittance and allow for a high surface tilt angle.

Abstract: A process for the preparation of aromatic polyamide pulp having excellent properties comprising:a) preparing a polymerization solvent by adding a Lewis acid type compound to an amide type organic solvent, an urea type organic solvent or a mixture thereof;b) obtaining an anisotropic liquid crystalline polymer solution prior to gelation by dissolving an aromatic diamine in the prepared polymerization solvent and adding an aromatic diacid chloride to the solution, and effecting the polymerization thereof;c) maintaining the polymer solution at a predetermined temperature for a predetermined period; andd) separating the polymerization solvent and pulverizing the polymer by pulping machine.