The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 1992
Filed:
Jan. 22, 1990
Wolfgang Hesse, Taunusstein, DE;
Klaus Hofmann, Ingelheim, DE;
Erhard Leicht, Hofheim am Taunus, DE;
Hoechst Aktiengesellschaft, Frankfurt, DE;
Abstract
The preparation of novolaks from phenols or mixtures of different phenols, and oxo compounds or mixtures of oxo compounds by condensation of the reactants in a medium having a low water content in homogeneous phase at temperature of .gtoreq.110.degree. C., preferably between 115.degree. and 200.degree. C. and preferably at normal pressure, in the presence of water-immiscible and/or only partially water-miscible inert organic solvents and of acids as catalysts with removal of water by distillation, the medium having a low water content being prepared or maintained by distilling off water from the reaction mixture, preferably by azeotropic distillation. Particular advantages are obtained when readily volatile oxo compounds, in particular aqueous formaldehyde solutions, are used. Use of the novolaks as reinforcing resins for rubber and elastomers, as tackifiers for rubber, as binders for friction linings, as curable molding compositions, impregnating agents, coatings, paints and as binders for fine-particle inorganic substrates.