Melamine resins, a process for their preparation and their use and molding compositions produced from the resins

US4430494A · kind A · utility

Assignee

• Cassella Aktiengesellschaft · DE

Inventors

• Hans Honel
• Walter Michel · La Ronge, CA
• Steffen Piesch · Oberursel, DE
• Karin Schluter · Frankfurt am Main, DE
• Alfons Wolf · Seligenstadt, DE

Key dates

• Filing date: Sep 30, 1982
• Grant date: Feb 7, 1984
• Expiry date: Sep 30, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L61/32
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Modified melamine-formaldehyde resins having a melamine:formaldehyde molar ratio of 1:(1.27 to 0.7) are prepared by heating melamine in an aqueous solution or suspension with formaldehyde in a melamine:formaldehyde molar ratio of 1:(1.27 to 0.7) at a pH value of 8 to 11 and at temperatures of 105.degree. to 160.degree. C. until the finished resin has reached a dilutability with water of 1:(0.1 to 4) at 20.degree. C., and, before, during or after the condensation reaction, adding less than 25% by weight of a glycol ether of the formula EQU R(OCH.sub.2 CH.sub.2).sub.n OH in which R denotes alkyl having 1 to 4 C atoms and n denotes an integer from 1 to 5, and/or of p-toluenesulfonamide. The resins are used in particular for the production of molding compositions.