Ammeline-melamine-formaldehyde resins (AMFR) and method of preparation
US5254665A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1992 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | Aug 24, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G12/32
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Ammeline-melamine-formaldehyde resins (AMFR) containing from 5-100% ammeline were synthesized by the polymerization of the sodium salt of ammeline, which must be made in advance, melamine, and formaldehyde in basic medium (pH=9.2-10.0). In this copolymerization, it is possible to make uniform random AMFR resins with any mole ratio of ammeline salt to melamine. Preferably the AMFR resin will contain from 5-10% ammeline. As an "ionomer" or a "polyelectrolyte," both the solid and solution properties of these resins (such as melting temperature, solubility, solution stability, etc.) depended directly on the mole ratio of ammeline to melamine and formaldehyde, and/or on the pH value of the medium in which the AMFR resin was present. The pH value controlled the ammeline rings/ammeline's salt groups and also the ratio of unprotonated to protonated amino groups on both the melamine and ammeline rings. These polymers have different solubilities, cloud points and solution lifetimes (which depend on pH) than melamine-formaldehyde resins. AMFR systems containing from 5-10% ammeline are more flexible than MFR resins and exhibit different adhesion properties than MFR resins.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.