Polyamide-imide-modified polyurethane insulation enamel composition
US5514747A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1995 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Feb 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01B3/303
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for preparing a polyamide-imide-modified polyurethane varnish composition for coating a conductive wire to form a varnished wire. The method comprises the steps of: (a) preparing a first intermediate reaction product, which is an isocyanate compound, (b) preparing a second intermediate reaction product, which is a hydroxy compound, and (c) mixing the first and second intermediate reaction products with a diluent to form the polyamide-imide-modified polyurethane varnish composition. The first intermediate reaction comprises the steps of: (I) preparing a first reaction mixture containing a phenol or a derivative of phenol, a diisocyanate, and a dihydroxy compound in a first organic solvent, and reacting the first reaction mixture at room temperature; (ii) adding a diacid compound or trimellitic anhydride or mixture thereof to the first reaction mixture, and reacting at 100.degree..about.140.degree. C.; wherein the diisocyanate is stoichiometrically equivalent to the sum of the phenol or derivative of phenol, the dihydroxy compound, and the diacid compound or the trimellitic anhydride or mixture thereof. The second intermediate reaction comprises the steps of: (I) preparing a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.