Method of preparation for a degradable, water and oil resistant protective membrane
US6599577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2002 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Mar 8, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/323
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a method of preparation for a degradable, water and oil resistant protective membrane. In the said method, carbon dioxide copolymer is dissolved in a low toxic or non-toxic solvent to form a solution of 3-6 wt % concentration. After standing and filtration to remove metal oxide, the solution is used to coat the surface of the fabricated starch, paper pulp, or straw tableware by spraying or dipping. The residual solvent is removed by drying process and a degradable, water and oil resistant and transparent protective membrane is obtained. The thickness of the protective membrane is in the range of 10-20 micrometer. Metal ion content is lower than 1 ppm. No leakage and deformation of the tableware are observed after the tableware is immerged in water or edible oil for 4 hours at 80° C. The decoloration test by cold edible oil and ethanol is negative. Fungus test gives grade V.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.