Process for solvent casting a film
US4664859A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 10, 1986 |
| Grant date | May 12, 1987 |
| Priority date | — |
| Expiry date | Jan 10, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31855
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for solvent casting acrylic films having superior properties by casting a solution comprising an organic solvent and a polymer system of one or more acrylic polymers onto a carrier, removing the solvent thereby forming the film on the carrier, and stripping the film from the carrier, is disclosed. The polymer system comprises at least one polymer having the following properties: Total Elongation (%) of about 120-250; Tear Resistance of about 4.5-12.5 g/mil (which is about 177-492 mg/micron); Tensile Strength of about 4500-5000 lbs/in.sup.2 (about 317-387 kg/cm.sup.2); Molecular Weight (amu) of about 250,000-500,000; Acid Content (%) of about 0.05-5.0; and Tucon hardness (Knoop No.) of about 6-12. The acrylic film has Total Elongation, Tensile Strength, Tear Resistance, Acid Content and Tucon hardness in the aforesaid ranges, and is substantially free of reactive groups, such as hydroxy groups. The residual solvent in the film is (weight %) about 0-3. The film has dimensional stability (% shrinkage at about 130.degree. C. for films of 0.5-5.0 mils, which is about 13-127 microns) of about 0.3. The thickness of the films is generally about 0.5-5.0 mils (which is about 13-127…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.