New products, especially based on poly - imide and resins of halogenated hydrocarbons, and their preparation,

摘要

A method of making an abrasive article comprises mixing at least one diamine having the formula H2N-R-NH2, where R1 is an aromatic, aliphatic, cycloaliphatic, combination of aromatic and aliphatic, heterocyclic or bridged organic radical where the bridge is oxygen, nitrogen, sulphur, silicon or phosphorus, or a substituted derivative thereof with at least one tetracarboxylic acid dianhydride of the formula FORM:1046230/C4-C5/1 where R is a tetravalent radical having at least 2 carbon atoms, no more than 2 carbonyl groups of said dianhydride attached to any one carbon atom of said tetravalent radical, in a solvent for at least one of said reactants, the solvent being inert to the reactants under conditions to form a polyamide-acid having an inherent viscosity of at least 0.1, adding at any stage prior to shaping crystalline, abrasive particles of green rouge, silica, alumina, boron carbide, silicon carbide, steel or diamond to form a shapeable polymeric composition having said particles dispersed uniformly therein; shaping said composition into a shaped article and converting the polymer to polyimide. Many conventional reactants and solvents are specified. Examples are given, the exemplified articles being discs and films.ALSO:A method of making an abrasive article comprises mixing at least one diamine having the formula H2N-R1-NH2, where R1 is an aromatic, aliphatic, cycloaliphatic, combination of aromatic and aliphatic, heterocyclic or bridged organic radical where the bridge is oxygen, nitrogen, sulphur, silicon or phosphorus, or a substituted derivative thereof with at least one tetracarboxylic acid dianhydride of the formula FORM:1046230/C3/1 where R is a tetravalent radical having at least 2 carbon atoms, no more than 2 carbonyl groups of said dianhydride attached to any one carbon atom of said tetravalent radical, in a solvent for at least one of said reactants, the solvent being inert to the reactants under conditions to form a polyamide-acid having an inherent viscosity of at least 0.1; adding at any stage prior to shaping crystalline, abrasive particles of green rouge, silica, alumina, boron carbide, silicon carbide, steel or diamond to form a shapeable polymeric composition having said particles dispersed uniformly therein; shaping said composition into a shaped article and converting the polymer to polyimide. Many conventional reactants and solvents are specified. Examples are given, the exemplified articles being discs and films.