Method of preparing a urea-formaldehyde combination foam that is low in formaldehyde
Patent 4537913 Issued on August 27, 1985. Estimated Expiration Date: 
March 7, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 7, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2559891 3231525 Method for producing chemically stable urea-formaldehyde foams Urea formaldehyde foam with low shrinkage Patent #: 4225680 InventorApplicationNo. 06/586966 filed on 03/07/1984US Classes:521/107, Phosphorus atom is part of an organic compound521/116, -C-X-C- compound contains a -C-XH group wherein X is a chalcogen atom521/120, Ingredient contains a sulfur atom521/121, Sulfur atom is part of an organic compound521/125, Organic metal compound contains a Group I or Group II metal atom521/187, Nitrogen containing reactant521/188, Nitrogen reactant contains a -N-C(=X)-N group wherein X is a chalcogen atom, e.g.,urea, etc.528/259, With >N-C(=X)-N< -containing reactant wherein X is a chalcogen atom528/260Two or more >N-C(=X)-N< -containing reactantsExaminersPrimary: Foelak, MortonAttorney, Agent or FirmInternational ClassesC08J 9/00 (20060101)C08J 9/30 (20060101) Foreign Application Priority Data1983-03-09 DEAbstractA U.F. foam that is diamensionally stable, but low in formaldehyde, was made by adding to a conventional solution of a urea formaldehyde resin precondensate, before foaming, up to 50% urea, relative to the solid resin substance, and one or several connecting agents from the group of sulfurous alkyl compounds, saturated monobasic carbonic acids, saturated and unsaturated dicarbonic acids, purine compounds, inorganic acids of the group of halogens and chalcogens, and their salts, phosphoric acids and their salts, alkali metal salts and alkaline earth metal salts, in such quantity and in such a way that the pH of the resulting solution remains above 7; and subsequently foaming the solution with a hardener/foaming-agent solution in the conventional manner. | |
