Claims
- 1. A method for manufacturing a transparent polymeric film providing a barrier to the transmission of ultra-violet light comprising:
- adding titanium dioxide having an average particle size less than the wavelength of visible light and greater than the wavelength of ultra-violet light to a copolymer of ethylene and propylene to provide a masterbatch;
- mixing said masterbatch with a homopolymer of polypropylene to provide an extrudable resin; and
- forming said extrudable resin as a transparent film.
- 2. The method according to claim 1, wherein the average particle size of said titanium dioxide is from about 0.010 .mu.m to 0.050 .mu.m.
- 3. The method according to claim 2, wherein the average particle size of said titanium dioxide is from about 0.018 .mu.m to 0.040 .mu.m.
- 4. The method according to claim 1, wherein the percentage by weight of said titanium dioxide is up to about 3.0%.
- 5. The method according to claim 4, wherein the percentage by weight of said titanium dioxide is from about 0.1% to 1.5%.
- 6. The method according to claim 1, wherein said copolymer includes from about 3% to about 10% by weight of ethylene.
- 7. A transparent polymeric film structure providing a barrier to the transmission of ultra-violet light produced by the process comprising:
- adding titanium dioxide having an average particle size less than the wavelength of visible light and greater than the wavelength of ultra-violet light to a copolymer of ethylene and propylene to provide a masterbatch;
- mixing said masterbatch with a homopolymer of polypropylene to provide an extrudable resin; and
- forming said extrudable resin as a transparent film.
- 8. The film according to claim 7, wherein the average particle size of said titanium dioxide is from about 0.010 .mu.m to 0.050 .mu.m.
- 9. The film according to claim 8, wherein the average particle size of said titanium dioxide is from about 0.018 .mu.m to 0.040 .mu.m.
- 10. The film according to claim 7, wherein the percentage by weight of said titanium dioxide is up to about 3.0%.
- 11. The film according to claim 10, wherein the percentage by weight of said titanium dioxide is from about 0.1% to 1.5%.
- 12. The film according to claim 7, wherein said copolymer includes from about 3% to about 10% by weight of ethylene.
Parent Case Info
This is a continuation of application(s) Ser. No. 08/072,305, filed on Jun. 9, 1993, now abandoned.
US Referenced Citations (14)
Foreign Referenced Citations (4)
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Date |
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CAX |
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EPX |
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JPX |
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Continuations (1)
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Number |
Date |
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Parent |
72305 |
Jun 1993 |
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