1. A white, sealable, biaxially oriented, coextruded polyester film encompassing at least one base layer B and at least one sealable outer layer A, both made from thermoplastic polyester, wherein at least the base layer B also comprises, alongside the thermoplastic polyester, an amount in the range from about 2 to about 60% by weight, based on the weight of the base layer B, of a cycloolefin copolymer (COC) where the COC has a glass transition temperature Tg of >70 C.
2. The white, sealable polyester film as claimed in claim 1, wherein the cycloolefin copolymer (COC) comprises polynorbornene, polydimethyloctahydronaphthalene, polycyclopentene, or poly(5-methyl)norbornene, and has a glass transition temperature Tg in the range from about 90 to about 250 C.
3. The white, sealable polyester film as claimed in claim 1, wherein the COC has a glass transition temperature Tg in the range from about 110 to about 220 C.
4. The white, sealable polyester film as claimed in claim 1, which has a whiteness of more than about 70% and an opacity of more than about 55%.
5. The white, sealable polyester film as claimed in claim 1, wherein the sealable outer layer A comprises a polyester copolymer which contains an amount in the range from about 40 to about 95 mol % of ethylene terephthalate units and contains an amount in the range from about 60 to about 5 mol % of ethylene isophthalate units, based on the total amount of carboxylic acid units, and wherein the monomer units derive from aliphatic, cycloaliphatic or aromatic diols from about 0.1 to about 10% by weight, preferably from about 0.12 to about 8% by weight and in particular from about 0.15 to about 6% by weight.
6. The white, sealable polyester film as claimed in claim 1, wherein the sealable outer layer A has a thickness in the range from about 0.2 to about 5.0 m, and has a minimum sealing temperature of 200 C.
7. The white, sealable polyester film as claimed in claim 1, which has a total thickness in the range from about 4 to about 500 m.
8. The white, sealable polyester film as claimed in claim 1, wherein the roughness of the sealable outer layer A, expressed via its Ra value, is less than or equal to about 100 nm, and wherein its value measured for surface gas flow time is in the range from about 50 to about 4000 s.
9. The white, sealable polyester film as claimed in claim 8, wherein an intermediate layer has been arranged between the COC-containing base layer B and the sealable outer layer A.
10. The white, sealable polyester film as claimed in claim 1, which has another outer layer C whose coefficient of friction (COF) with respect to itself is smaller than about 0.7, and whose roughness, expressed via its Ra value, is 30 nm, and whose value measured for surface gas flow time is in the range below about 500 s.
11. The white, sealable polyester film as claimed in claim 10, wherein the outer layer C comprises an amount of pigments in the range from about 0.1 to about 10% by weight.
12. A process for producing a polyester film as claimed in claim 1, which comprises compressing and plasticizing, in separate extruders, a polymer or a polymer mixture for each of the layers to produce polymer melts, then simultaneously pressing the melts through a flat-film die (slot die) to produce an extruded multilayer film, drawing off the extruded multilayer film on one or more take-off rollers to produce a prefilm, then biaxially stretching and heat-setting the resultant prefilm.
13. The process as claimed in claim 13, wherein cut material arising directly during production of the film is reused for film production in the form of regrind in an amount in the range from about 10 to about 70% by weight, based on the total weight of the film.
14. A method of making an interior decoration which method comprises converting a white, sealable film as claimed in claim 1 into an interior decoration.
15. A method of making a display, for placards which method comprises converting a white, sealable film as claimed in claim 1 into a display, for placards.
16. A method of making a promotional item which method comprises converting a white, sealable film as claimed in claim 1 into a promotional item.
17. A method of making a laminating medium which method comprises converting a white, sealable film as claimed in claim 1 into a laminating medium.
18. A method of making a protective cover which method comprises converting a white, sealable film as claimed in claim 1 into a protective cover.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A window for use in an electronic device, comprising:
a transparent soft layer, the soft layer for being exposed to a user’s touch; and
a transparent strengthening layer, the soft layer overlapping the strengthening layer and for positioning inside an electronic device,.
2. The window as claimed in claim 1, wherein:
the soft layer being made of polyethylene terephthalate; and
the strengthening layer being made of polymethyl methacrylate
3. The window as claimed in claim 2, wherein the soft layer is adhered to a portion of the electronic device by an adhesive.
4. The window as claimed in claim 3, wherein the adhesive is transparent.
5. The window as claimed in claim 4, wherein the adhesive is octyl-cyanoacrylate.
6. A housing for use in electronic device, comprising:
a base; and
a transparent window attached to the base, the window includes a transparent soft layer for being exposed to a user’s touch and a transparent strengthening layer positioned inside an electronic device and overlapping with the transparent soft layer.
7. The housing as claimed in claim 6, wherein:
the soft layer being made of polyethylene terephthalate; and the strengthening layer being made of polymethyl methacrylate.
8. The housing as claimed in claim 7, wherein the soft layer is adhered to a portion of the base by an adhesive.
9. The housing as claimed in claim 8, wherein the adhesive is transparent.
10. The housing as claimed in claim 9, wherein the adhesive is octyl-cyanoacrylate.
11. A window for use in an electronic device, comprising:
a transparent soft layer, the soft layer being made of polyethylene terephthalate; and
a transparent strengthening layer, the soft layer being attached on the strengthening layer, the strengthening layer being made of polymethyl methacrylate.