Abstract: Premix for the production of mouldings, containingA) from 40-99.95% by weight of polymer granules A based on a polyaryl ether sulfone, polyaryl ether ketone, polyimide, polyamide imide or polyether imide, or a mixture thereof,B) up to 50% by weight of fillers B in fiber or particle form, or a mixture thereof,C) from 0.05-10% by weight of a compound C ether of the general formula X ##STR1## where A1 to A7 are identical or different and, independently of one another, are a radical of the formula --CO--, --O--, --S--, --SO.sub.2 --, --C(CH.sub.3).sub.2 --, a chemical bond, ##STR2## and k, l, m, n, p and q are each 0 or 1, or a C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.8 -alkoxy or cyano derivative thereof which is substituted on the aromatic ring, or of the general formula Y ##STR3## where R is C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.8 -alkoxy or cyano, A8 to A11 are as defined for A1 to A7, r, s and t are 0 or 1, and x is 2, 3 or 4, or a mixture thereof,is described.

Abstract: Latent, heat-curable epoxy resin compositions containing metal carboxylate curing systems provide exceptional latency, particularly at elevated temperature, as well as facile curing, high T.sub.g and adhesive strength, and other attractive properties. The metal carboxylates comprise alkali metals and alkaline earth metals, aromatic and aliphatic metal carboxylates. The preferred curing systems comprise synergistic combinations of the metal carboxylates with cure modifiers.

Abstract: Linear aromatic polymeric species, particularly oligomers and polymers are produced under mild conditions in good yield by reacting an at least binuclear aromatic compound with an alkylidene bisphenol in the presence of a non C-alkylatable hydroxy substituted aromatic compound effective to stabilize a generated carbonium ion intermediate; the alkylidene bisphenol may be formed in situ from a ketone or aldehyde in the presence of a catalytic amount of a hydroxy substituted aromatic compound effective to generate a carbonium ion with the ketone or aldehyde; carrying out the reaction under reduced pressure, particularly high vacuum permits direct production of high polymers; the oligomers are useful in the manufacture of high molecular weight engineering or industrial plastics; the polymers may be used directly as such plastics.

Abstract: Aromatic polyamides with an improved stability toward thermal oxidation was achieved by polycondensation being performed in the presence of 0.05 to 4 mol % of a catalyst comprising a mixture of phosphorus compounds and metal salts.With the process according to the invention, it is possible to obtain aromatic polyamides stable toward thermal oxidation.

Abstract: Disclosed is an aromatic diamine having the general formula ##STR1## where A is a group containing at least one aromatic ring, each Y is independently selected from ##STR2## R is a group containing at least one olefinically unsaturated group, R' is hydrogen, alkyl to C.sub.25, aryl, or R, n is 1 to 4, and the number of olefinic groups in Y is at least 3 when each Y is ##STR3## and otherwise is at least 2. Photosensitive polyamic acids and polyimides can be prepared from the aromatic diamines which can be crosslinked with light to a mask to form patterns on a substrate.

Abstract: A process for preparing a metal phenolate of the formula II:Cl--Ar.sub.1 COAr.sub.2 OM (II)wherein each of Ar.sub.1 and Ar.sub.2 which may be the same or different is a bivalent group of the formula: ##STR1## wherein each of R.sup.1 and R.sup.12 is a hydrogen atom, a halogen atom, an alkoxy group, a phenoxy group, an alkyl group, a cycloalkyl group, a phenyl group, an aralkyl group, an acyl group, a nitrile group, a nitro group or an acyloxy group, each of Y and Z is an oxygen atom or a ketone group, and each of n and m is an integer of from 0 to 4, and M is an alkali metal, which comprises reacting a phenol compound of the formula I:Cl--Ar.sub.1 COAr.sub.2 OH (I)wherein Ar.sub.1 and Ar.sub.2 are as defined above, with an alkali metal compound in the presence of water, and then removing water, characterized in that water is azeotropically distilled off together with an organic solvent capable of forming an azeotropic mixture with water.

Abstract: The invention provides aromatic polyamides having an improved resistance to thermo-oxidation. This is achieved by carrying out the polycondensation in the presence of a catalyst system which comprises a mixture of a phosphorus compound and a tin(II) compound or is a compound which contains both elements. The process according to the invention allows aromatic polyamides to be obtained which are resistant to thermo-oxidation (discoloration).

Abstract: Disclosed is a poly(ether-ketone) having an inherent viscosity of at least 0.4 and consisting of the repeating unit ##STR1## wherein each Ph is 1,4-phenylene. The poly(ether-ketone) is derived from two specific reactants, 1,3-bis-(4-phenoxybenzoyl)benzene and 4,4'-oxydibenzoic acid which may be reacted in the presence of methanesulfonic acid and phosphorus pentoxide.

Abstract: To produce flame-retardant thermostable new homopolyimides having structural units of the general formula ##STR1## by reacting 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride with an overall equimolar amount of 2,4- and/or 2,6-toluene diisocyanate, the reaction is carried out in the presence of a polymerization accelerator. The new homopolyimides have a glass transition point of at least 320.degree. C. and are processible to moulded articles exhibiting a similarly good structural strength as could hitherto be observed in mixed polyimides only. Furthermore, the new homopolyimides can be spun to fibres.

Abstract: This invention relates to making an arylene sulfide ketone polymer. In accordance with this invention, a diahloaromatic ketone, a polar organic compound, and an alkali metal sulfide are mixed together to form a first reaction mixture. This first reaction mixture is subjected to a first set of polymerization conditions effective to produce a polymerization mixture. This polymerization mixture is then dehydrated to form a dehydrated polymerization mixture. Additional dihaloaromatic ketone and polar organic compound is then mixed with the dehydrated polymerization mixture to form a second reaction mixture. This second reaction mixture is then subjected to a second set of polymerization conditions such that an arylene sulfide ketone polymer is formed.

Abstract: The solvent-resistance and thermal stability of polyamideimides of the general formulae: ##STR1## is improved by capping the amideimides with a crosslinking functionality (Y) containing a residue selected from the group of: ##STR2## wherein R.sub.1 =lower alkyl, lower alkoxy, aryl, aryloxy, substituted alkyl, substituted aryl (either including hydroxyl or halo-substituents), halogen, or mixtures thereof;j=0, 1, or 2;G=--CH.sub.2 --, --O--, --S--, --SO.sub.2 --, --SO--, --CO--, --CHR--, or --CR.sub.2 --;R=hydrogen, lower alkyl, or phenyl;T=methallyl or allyl;Me=methyl;R.sub.2 =a trivalent organic radical; andR.sub.3 =a divalent organic radical.The amideimide oligomers may be linear or multidimensional, and can be processed into blends, prepregs, or composites. Methods of making these amideimides and intermediates useful in the syntheses are also described.

Abstract: Aromatic sulfide/ketone polymer is prepared from dihaloaromatic ketone, alkali metal sulfide, water and a polar organic compound. The polymerization reaction mixture comprising the aromatic sulfide/ketone polymer is subjected to a heat soak at elevated temperature then a separation agent (non-solvent) is added under controlled conditions and subsequently cooled to provide a mixture comprising particulate aromatic sulfide/ketone polymer.

Abstract: A process for the preparation of an aromatic polyether by condensation of dihydric phenols with activated aromatic dihalo compounds or by self-condensation of polynuclear activated halophenols employs a mixture of sodium carbonate and sodium hydrogen carbonate as a condensation auxiliary.By this means, the relatively low reactivity of the sodium carbonate is enhanced and the reaction rate is significantly increased.

Abstract: Aromatic polymers comprise divalent aromatic units connected by ether and/or thioether linkages. At least one of such units carries at least one halogen radical linked to a nuclear carbon by a halogen-carbon bond or a functionalized derivative thereof linked to a nuclear carbon atom by a carbon-carbon bond.

Abstract: A polymerization process is provided for the production of high molecular weight aromatic sulfide/ketone polymer from at least one dihaloaromatic ketone, at least one alkali metal sulfide, at least one polar organic compound and water wherein the polymerization reaction is conducted in two distinct steps separated by an intermediate step of removal of at least a portion of the water.

Abstract: A process for producing an aromatic polyketone which comprises polymerizing an appropriate monomer or monomers by a Friedel-Crafts polymerization reaction using a Lewis acid catalyst. A controlling agent such as a Lewis base may be added to the reaction medium and/or the reaction is conducted under specified conditions to control the reaction. The reaction medium comprises, for example, aluminum trichloride as the Lewis acid, an organic Lewis base such as N,N-dimethylformamide or an inorganic Lewis base such as sodium or lithium chloride, and a diluent such as methylene chloride or dichloroethane. The amount of Lewis acid, the amount of Lewis base, the temperature of the reaction and the monomer to diluent molar ratio are varied depending on the monomer system to obtain melt-processable, high molecular weight, substantially linear polymers, for example poly(carbonyl-p-phenylene-oxy-p-phenylene), poly(carbonyl-p-phenylene-oxy-p-phenylene-oxy-p-phenylene), and the like.

Abstract: Aromatic oligomers, in particular arylene ketone and arylene sulfone oligomers, are prepared by reacting an appropriate monomer system in the presence of free Lewis acid and a complex between a Lewis acid, for example, aluminum trichloride, and a Lewis base, for example, N,N-dimethylformamide, and, optionally, a diluent, such as methylene chloride. The process is particularly advantageous for the preparation of substantially or all paralinked arylene ether ketone oligomers as the presence of the Lewis acid/Lewis base complex markedly reduces alkylation and ensures the substantial absence of ortho substitution. The monomer system can be, for example, a self-reacting monomer such as p-phenoxy-benzoyl chloride or a two-monomer system such as 1,4-diphenoxybenzene and terephthaloyl chloride.

Abstract: Friedel Crafts preparation of arylene ether ketone polymers with an exceptionally high degree of isomeric purity and freedom from by-products can be achieved by adding to the Lewis acid reaction system a protic controlling agent selected from ROX, water, RCOOX, RSO.sub.3 X, and ROY, wherein R is organic, X is hydrogen or metal, and Y is metal. Contrary to conventional expectation, the protic agent does not significantly acylate or alkylate the polymer, and agents of relatively low molecular weight, e.g. benzoic acid, can be selected to produce dispersions of the resulting polymers. The controlling agent also apparently acts to maintain the polymer in solution until a desired molecular weight is reached.

Abstract: Novel copolymers and terpolymers are produced from carbon monoxide, a functionally-substituted ethylenically unsaturated compound wherein the functional substituent is separated from the ethylenic unsaturation by a divalent bridging group of at least one carbon, and optionally an ethylenically unsaturated hydrocarbon. The polymerization is conducted under polymerization conditions in the presence of a catalyst composition formed from a palladium compound, the anion of a non-hydrohalogenic acid having a pKa less than about 6 and a bidentate ligand of phosphorus or of nitrogen.

Abstract: Friedel Crafts preparation of arylene ether (especially arylene ether ketone) oligomers with an exceptionally high degree of isomeric purity and freedom from by-products can be achieved by adding to the Lewis acid reaction system a protic controlling agent selected from ROX, water, RCOOX, RSO.sub.3 X, and ROY, wherein R is organic, X is hydrogen or metal, and Y is metal.Contrary to conventional expectation, the protic agent does not significantly acylate or alkylate the Friedel Crafts reaction product, and controlling agents of relatively low molecular weight, e.g., benzoic acid, can surprisingly be selected to produce dispersions of the resulting oligomers.

Abstract: Disclosed is an improved process for the preparation of poly(ether-ketone) polymers by the reaction of at least one dicarboxylic acid with certain bis(phenoxybenzoyl) compounds in the presence of a perfluoroalkylsulfonic acid and (1) an oxide of phosphorus and/or (2) a perhaloalkanoic anhydride.

Abstract: Condensation polymers of high molecular weight, such as polymers, polyureas, and polyamides, are usually prepared at temperatures of 200.degree. C. or greater. However, by utilizing the catalyst system of the present invention condensation polymers can be synthesized at much lower temperatures. These catalyst systems are comprised of (1) a silicon-phosphorus composition which contains at least one divalent oxygen atom which is bonded directly to a tetravalent silicon atom and a trivalent or pentavalent phosphorus atom; and (2) at least one acid acceptor. For example, P(OSiR.sub.3).sub.3 wherein R can be an aliphatic or aromatic hydrocarbon radical, can be used in conjunction with a basic solvent as a catalyst system. Polymeric agents having pendant diphenylphosphine dichloride groups can also be used in conjunction with an acid acceptor as a catalyst system.

Abstract: A process for preparing a polyamide which comprises polycondensing a dicarboxylic acid and a diamine by using a combination of at least one phosphine and at least one disulfide as the condensing agent.

Abstract: Aromatic oligomers, in particular arylene ketone and arylene sulfone oligomers, are prepared by reacting an appropriate monomer system in the presence of free Lewis acid and a complex between a Lewis acid, for example, aluminum trichloride, and a Lewis base, for example, N,N-dimethylformamide, and, optionally, a diluent, such as methylene chloride. The process is particularly advantageous for the preparation of substantially or all paralinked arylene ether ketone oligomers as the presence of the Lewis acid/Lewis base complex markedly reduces alkylation and ensures the substantial absence of ortho substitution. The monomer system can be, for example, a self-reacting monomer such as p-phenoxy-benzoyl chloride or a two-monomer system such as 1,4-diphenoxybenzene and terephthaloyl chloride.

Abstract: An aromatic polyamide having a high molecular weight is produced by a polycondensation reaction of an aromatic aminocarboxylic acid and/or a mixture of an aromatic dicarboxylic acid and an aromatic diamine in a polar solvent in the presence of a dehydrating catalyst with heating at a temperature of about 160.degree. C. or higher.

Abstract: A method of manufacturing polyamides from aromatic dicarboxylic acids and aromatic diamines in the presence of catalytic amounts of a phosphorous-containing catalyst and a 4-diakylaminopyridine as cocatalyst, at temperatures above 180.degree. C., is described.

Abstract: A process for producing an aromatic polyketone which comprises polymerizing an appropriate monomer or monomers by a Friedel-Crafts polymerization reaction using a Lewis acid catalyst. A controlling agent such as a Lewis base may be added to the reaction medium and/or the reaction is conducted under specified conditions to control the reaction. The reaction medium comprises, for example, aluminum trichloride as the Lewis acid, an organic Lewis base such as N,N-dimethylformamide or an inorganic Lewis base such as sodium or lithium chloride, and a diluent such as methylene chloride or dichloroethane. The amount of Lewis acid, the amount of Lewis base, the temperature of the reaction and the monomer to diluent molar ratio are varied depending on the monomer system to obtain melt-processable, high molecular weight, substantially linear polymers, for example poly(carbonyl-p-phenylene-oxy-p-phenylene), poly(carbonyl-p-phenylene-oxy-p-phenylene-oxy-p-phenylene), and the like.

Abstract: The preparation of poly(arylene ether ketones) by Friedel-Crafts polymerization, in the presence of a Lewis acid catalyst and a diluent, is conducted under conditions in which the polymer and/or its complex with the catalyst is suspended in the diluent during at least part of the polyreaction mixture if desired. The dispersant may be a polymer or an organic compound containing at least eight carbon atoms and is preferably a Lewis base. The dispersant preferably contains at least one molecular segment substantially compatible with the poly(arylene ether ketone) or its complex with the Lewis acid and substantially incompatible with the diluent and at least one molecular segment substantially compatible with the diluent and substantially incompatible with the poly(arylene ether ketone) or its complex with the Lewis acid.

Abstract: Condensation polymers of high molecular weight, such as polyesters, polyureas, and polyamides, are usually prepared at temperatures of 200.degree. C. or greater. However, by utilizing the catalyst system of the present invention condensation polymers can be synthesized at much lower temperatures. These catalyst systems are comprised of (1) a silicon-phosphorus composition which contains at least one divalent oxygen atom which is bonded directly to a tetravalent silicon atom and a trivalent or pentavalent phosphorus atom; and (2) at least one acid acceptor. For example, P(OSiR.sub.3).sub.3 wherein R can be an aliphatic or aromatic hydrocarbon radical, can be used in conjunction with a basic solvent as a catalyst system. Polymeric agents having pendant diphenylphosphine dichloride groups can also be used in conjunction with an acid acceptor as a catalyst system.

Abstract: Methods of making modified polyimide adhesives and laminating compositions. These adhesives are also particularly useful as the matrix material in high strength fiber reinforced composites. The adhesive compositions are prepared by initially reacting an oxoimine with one or more tetracarboxylic acid dianhydrides, which is primarily 1, 2, 3, 4-butanetetracarboxylic acid dianhydride. The resulting bisimide is dissolved in a non-reactive solvent and a suitable diamine is added to react with the bisimide, producing a liquid resin solution which is essentially a polyamide resin solution. This solution is useful as an adhesive or a fiber composite matrix which can be cured to a polyimide at moderate processing temperatures. The final adhesive bond or matrix is found to be flexible, strong and very resistant to flame, high temperatures, oils and solvents.

Abstract: Heat curable epoxy-styrene compositions exhibiting improved processability, low viscosity, long pot life, and fire retardancy which when cured with a special acid anhydride/onium salt epoxy curing blend in combination with a free-radical catalyst, yield cured products exhibiting improved physical properties, such as increased heat deflection temperature, increased flexural strength and increased flexibility.

Abstract: Aromatic N-glycidylamines are prepared by treatment of an amine having at least one, and preferably two or more aromatic amino hydrogen atoms, with epichlorohydrin in the presence, as catalyst, of a di- or higher-valent metal salt of nitric or perchloric acid, or of a carboxylic or sulphonic acid substituted by fluorine, chlorine or bromine on the carbon atom alpha to the carboxylic or sulphonic acid group, and dehydrochlorinating the product. The presence of the metal salt gives a product having a higher glycidyl content and a lower viscosity than does the same reaction in the absence of such a salt.Suitable aromatic amines include aniline, phenylene diamines, phenylene diamines substituted on the aromatic ring and bis(4-aminophenyl)methane. The metal salt may be of, for example, magnesium, calcium, zinc, manganese, nickel, iron, lanthanum, vanadium, ytterbium or uranium.

Abstract: A layered oxide containing vanadium together with phosphorus or arsenic and an organic group may be prepared which has a unique layered structure of the formula: VORAO.sub.3.nS or VOROAO.sub.3.nS where A is phosphorus or arsenic, S is a solvent molecule, R is an unsubstituted or alkyl-, alkoxy- or aryl-substituted alkyl or aryl group, and n is zero or a positive number. These layered compounds are characterized in that the vanadium is substantially in a 4+ oxidation state and is present in an amount such that the molar ratio of A:V ranges from 0.8 to 1.2 throughout the oxide. Also the R groups are covalently bound to an A atom in the vanadium oxide layer directly through either carbon or oxygen atoms.

Abstract: A condensation polymer having a .eta.sp/C=0.1-1.5, containing an anthracene unit in the main chain of the polymer, which is found to have various functions of ultraviolet absorption, fluorescence emission, photoconductivity, organic semiconductor characteristics, etc. as well as excellent flexibility and mechanical strength, is prepared by condensation of an anthracenediol compound with a dicarboxylic acid dihalide or a hydrocarbylene dihalide.

Abstract: In a process for producing an aromatic polyamide-imide by polycondensation of an aromatic tricarboxylic acid and/or aromatic tricarboxylic anhydride and an aromatic diamine with heating in the presence of a dehydration catalyst, the improvement which comprises using a solvent containing sulfolane as a reaction medium.

Abstract: Production of an aromatic polyketone by reacting in the presence of a fluoroalkane sulphonic acid the reactants selected from: (a) a mixture of (i) at least one aromatic diacyl halide WOC--Ar--COW where --Ar'-- is a divalent aromatic radical, W is halogen and COW is an aromatically bound acyl halide group, which diacyl halide is polymerizable with the at least one aromatic compound of (ii), and (ii) at least one aromatic compound H--Ar'--H where --Ar'-- is a divalent aromatic radical and H is an aromatically bound hydrogen atom, which compound is polymerizable with the at least one diacyl halide of (i); (b) at least one aromatic monoacyl halide H--Ar"--COW where --Ar"-- is a divalent aromatic radical and H, W, and COW are as defined in (a), which monoacyl halide is self-polymerizable; and (c) a combination of (a) and (b).

Abstract: Production of an aromatic polyketone by reacting in the presence of a quinquevalent phosphorous halide (preferably PCl.sub.5) and a fluoroalkane sulphonic acid (preferably CF.sub.3 SO.sub.2 OH) the reactants selected from: (a) a mixture of (i) at least one aromatic dicarboxylic acid HO.sub.2 C--Ar--CO.sub.2 H where --Ar'-- is a divalent aromatic radical and CO.sub.2 H is an aromatically bound carboxylic acid group, which dicarboxylic acid is polymerizable with the at least one aromatic compound of (ii), and (ii) at least one aromatic compound H--Ar'--H where --Ar'-- is a divalent aromatic radical and H is an aromatically bound hydrogen atom, which compound is polymerizable with the at least one dicarboxylic acid of (i); (b) at least one aromatic monocarboxylic acid H--Ar"--CO.sub.2 H where --Ar"-- is a divalent aromatic radical and H and CO.sub.2 H are as defined in (a), which monocarboxylic acid is self-polymerizable; and (c) a combination of (a) and (b).

Abstract: Polyacetals and polyketals are prepared by reacting emulsified carbonyl compounds with emulsified polyfunctional alcohols in aqueous media and in the presence of specified polycondensation catalysts. Coherent films of the resultant polymers can be applied to substrates from aqueous or non-aqueous media.

Abstract: A process for the production of polyquinazolone-based polymers by reacting bisquinazolone with a diamine or a diamine substituted with a carboxylic acid, sulfonic acid or metal salt thereof in the presence of a Lewis acid catalyst or a phosphorus-containing dehydrating agent, where the polymers are useful to produce permselective membranes.

Abstract: A process for producing layered organometallic polymers having organo groups covalently bonded to pentavalent metal atoms. The pentavalent metal atoms are, in turn, covalently bonded through an oxygen linkage to tetravalent metal atoms. The layered organometallic compounds are produced by reacting a silyl diester of an organo-substituted pentavalent metal acid with at least one tetravalent metal ion.

Abstract: Polyamic acid having greatly increased adhesive ability is prepared by compacting a solid aromatic dianhydride to reduct its surface area to weight ratio and reacting the compacted dianhydride with a solution of an organic diamine in an inert non-aqueous solvent.

Abstract: Aromatic polymers containing benzenoid groups and oxygen atoms in the polymer chains are made by the action of an alkali metal hydroxide on a dihalogenobenzenoid compound in which each halogen atom is activated by an inert electron-attracting group such as --SO.sub.2 --.

Abstract: A thermostable heterocyclic polymer constituted by monomer units of the general formula ##STR1## where R.sup.1 and R.sup.2 denote an organic radical having from 2 to 1000 carbon atoms;a radical having 2 to 1000 carbon atoms, containing:1 to 1000 atoms of Si,and/or 1 to 1000 atoms of F,and/or 1 to 1000 atoms of Cl,and/or 1 to 1000 atoms of Br,and/or 1 to 1000 atoms of N,and/or 1 to 1000 atoms of S,and/or 1 to 1000 atoms of P,and/or 1 to 1000 atoms of B,and/or 1 to 1000 atoms of O,R.sup.1 and R.sup.2 being either the same or different;R.sup.3 .dbd.NH, CH.sub.2 ;R.sup.4 is a radical which, with R.sup.3 .dbd.NH, may be ##STR2## while with R.sup.3 .dbd.CH.sub.

Abstract: A method of preparing a polyamide acid type intermediate is provided, by using a purified inert solvent and monomer compounds, or diamine and/or diaminoamide compounds and a tetracarboxylic acid dianhydride, whose ionic impurities and free acid contents were reduced by recrystallization purification. The polyamide acid type intermediate may improve electrical properties and heat resistance of semiconductors when it is applied to, for instance, a surface-protecting film of semiconductors or an interlayer-insulating film of semiconductors having a multiple layer wiring structure.

Abstract: Aromatic polyimides with anhydride end groups are chain-extended (molecular weight increased) by reacting them with aromatic diamines or diamine terminated imide oligomers. The reaction can either be at a temperature above the melting point of the reactants or in solvents for the reactants. These polyimides can be shaped and formed prior to chain-extending.

Abstract: The present invention relates to novel, substantially insoluble and infusible plastics which are cross-linked by way of triazine rings and, optionally, by way of tri-substituted bis-oxymethylene urea groups or urethane groups.

Abstract: Triazine compounds and cross-linked polymer compositions are made by heating aromatic nitriles to a temperature in the range of from about 100.degree. C. to about 700.degree. C., and preferably in the range of from about 200.degree. C. to about 350.degree. C. in the presence of a catalyst or mixture of catalysts selected from one or more of the following groups: (A) organic sulfonic and sulfinic acids, (B) organic phosphonic and phosphinic acids, and (C) metallic acetylacetonates, at a pressure in the range of from about atmospheric pressure to about 10,000 p.s.i., and preferably in the range of from about 200 p.s.i. to about 750 p.s.i.