Abstract: A waterproof and breathable flame-retardant laminate of two layers of porous expanded polytetrafluoroethylene laminated together by a flame-retardant adhesive layer of poly(urea-urethane) polymer containing phosphorus ester groups built into the chains of the polymer. The flame-retardant components do not wash out of the adhesive and laminate under repeated laundering or dry cleaning.

Abstract: Novel meta phenylenediamines are provided having one or two particular benzyl radicals as substituents along with other optional substituents on the aromatic diamine ring and optionally substituents on the benzyl aromatic ring.The diamines are sterically hindered and thereby have lower amine reactivity as compared with the unsubstituted diamines.The diamines are useful as curing agents for epoxy resins and find particular utility as extenders in the formation of novel polyurethane-polyurea polymers.

Abstract: Novel meta phenylenediamines are provided having one or two particular benzyl radicals as substituents along with other optional substituents on the aromatic diamine ring and optionally substituents on the benzyl aromatic ring.The diamines are sterically hindered and thereby have lower amine reactivity as compared with the unsubstituted diamines.The diamines are useful as curing agents for epoxy resins and find particular utility as extenders in the formation of novel polyurethane-polyurea polymers.

Abstract: Novel meta phenylenediamines are provided having one or two particular benzyl radicals as substituents along with other optional substituents on the aromatic diamine ring and optionally substituents on the benzyl aromatic ring.The diamines are sterically hindered and thereby have lower amine reactivity as compared with the unsubstituted diamines.The diamines are useful as curing agents for epoxy resins and find particular utility as extenders in the formation of novel polyurethane-polyurea polymers.

Abstract: Novel amorphous polyimides are provided which are formed by the polymerization of bismaleimides with sydnones wherein carbon dioxide is evolved.The polyimides are readily soluble in dipolar aprotic solvents and are further characterized by high temperature stability to at least 300.degree. C.The polymers find particular utility in the form of films and solutions useful for wire enamel and electrical coatings.

Abstract: A process is described for the preparation of bis(aminophenyl)alkanes and bis(aminophenyl)cycloalkanes which comprises condensing a m-alkylphenol with an alkanone or cycloalkanone and heating the resulting condensation product with an at least stoichiometric amount of an acid addition salt of aniline or a substituted aniline or a mixture of such amines.

Abstract: A process is described for the isolation of 4,4'-diaminodiphenylmethane in substantially pure form (of the order of 99% purity) from admixtures thereof with the corresponding 2,4'-isomer and 2,2'-isomer. The dihydrochloride of the isomeric mixture of diamines is heated in the presence of an inert organic solvent with a mixture of isomers of the free diamine, in which the amount of the 4,4'-isomer is at least equal to that of the 2,4'-isomer in the dihydrochloride isomeric mixture. The isomeric mixture of the diamines may be employed in the form of a mixture of polymethylene polyphenyl polyamines containing a major portion of said diamines. The reaction product consists of the insoluble dihydrochloride of substantially pure 4,4'-diaminodiphenylmethane and a solution which is enriched in 2,4'-isomer as compared with the starting mixture of diamines.

Abstract: An improved process is described for the preparation of bis(aminophenyl)alkanes which comprises heating the corresponding bis(di-alkoxyphenyl)alkane or corresponding cyclic ethers of bis(phenyl)alkanes with an at least stoichiometric proportion of an aniline acid addition salt, optionally in the presence of an inert organic solvent.

Abstract: The use of certain dihydric phenols, alkyl ethers thereof, and alkyl-substituted monohydric phenols, as promoters in the acid catalyzed condensation of phenol and acetone to form Bisphenol-A enables said reaction to be carried out more rapidly, at significantly lower temperatures in some instances, with greater selectivity, i.e. reduction in proportion of undesired by-product, and most significantly, with the use of only catalytic amounts of mineral acid (instead of the large quantity in the conventional process) or the use of the inexpensive solid catalysts, such as acidic clays, which due to their low catalytic ability, are not useful as sole catalyst for this condensation if the promoter is not present. The promoters are readily recoverable for re-use.

Abstract: A process is described for the isolation of 4,4'-diaminodiphenylmethane in substantially pure form (of the order of purity of at least 95%) from admixtures thereof with the corresponding 2,4'-isomer and 2,2'-isomer. The isomeric mixture of diamines is heated, optionally in the presence of an inert organic solvent, with at least two equivalents, per mole of said diamine mixture, of a phenol or bisalkylidenephenol. The 4,4'-diaminodiphenylmethane forms a complex with said phenol and the 4,4'-isomer of the diamine is isolated therefrom in substantially pure form by treatment with alkali or by heating to dissociate. The isomeric mixture of diamines used as starting material can be employed in the form of a mixture of polymethylene polyphenyl polyamines containing a major portion of said diamines.

Abstract: A process is described for the selective removal of 2,2'- and 2,4'-diaminodiphenylmethanes from mixtures containing 2,2'-, 2,4'- and 4,4'-diaminodiphenylmethanes and polyamines by heating these mixtures in the presence of aqueous hydrochloric acid (55 to 95 percent by equivalents based on the total amine in the starting material) and formaldehyde. The process is particularly useful to facilitate the isolation of substantially pure 4,4'-isomer from aniline-formaldehyde condensation products. The pure 4,4'-isomer is a valuable intermediate for polyamides as well as for the corresponding diisocyanate. The by-products of the reaction are oligomeric polymethylene polyphenyl polyamines which are also useful as curing agents and intermediates for polymethylene polyphenyl polyisocyanates and the like.

Abstract: A process is described for the selective removal of 2,2'- and 2,4'-diaminodiphenylmethane from mixtures thereof with the corresponding 4,4'-isomer by heating the mixture of isomers in the presence of a 1,3,5-tri-arylhexahydro-1,3,5-triazine and a catalyst (aqueous mineral acid). The process is particularly useful in facilitating the isolation of substantially pure 4,4'-isomer from the aniline-formaldehyde condensation. The pure 4,4'-isomer is a valuable intermediate for polyamides as well as for the corresponding diisocyanate. The by-products of the reaction are oligomeric polymethylene polyphenyl polyamines which are also useful as curing agents and intermediates for polymethylene polyphenyl polyisocyanates and the like.

Abstract: 2,2'- AND 2,4'-DIAMINODIPHENYLMETHANE ARE SELECTIVELY REMOVED FROM ADMIXTURES THEREOF WITH THE 4,4'-ISOMER BY HEATING THE ISOMER MIXTURE AT 30.degree. TO 100.degree. C in the presence of styrene, .alpha.-alkylstyrenes, or the mono- or diamino nuclear substituted derivatives thereof and a catalyst (mineral acid, clays, diatomaceous earth, zeolites). The styrene or .alpha.-alkylstyrene can be employed as such or generated in situ from a precursor therefor. The process is particularly useful in facilitating the isolation of substantially pure 4,4'-diaminodiphenylmethane from the polyamine mixture obtained by condensation of aniline and formaldehyde.