White film to be laminated to metal surface and method of producing same
AssigneeUnitika Ltd.
InventorsNorikazu Matsui, Tetsuo Matsumoto, Tomohiro Hamada
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Abstract
A white film to be laminated to a metal surface and a method of producing the same. This white film comprises first and second layers which are laminated with the arrangement of second layer/first layer/second layer. The middle, first layer is composed of 80-40 wt % a first polyester, and 20-60 wt % titanium oxide added therewith. The front and back, second layers are composed of 80-100 wt % a second polyester, and 20-0 wt % titanium oxide. The film is a biaxially stretched film, and the content of titanium oxide in the entire film is 20-50 wt %.
Claims11
A white film to be laminated to a metal surface, comprising first and second layers which are laminated in the arrangement of second layer/first layer/second layer,
- wherein
- the first layer is made of a composition composed of 80-40 wt % polyester which, in turn, is composed of 100-75 mol % ethylene terephthalate unit and 0-25 mol % ethylene isophthalate unit, these units adding up to 100 mol %, and 20-60 wt % titanium oxide mixed with said polyester so that the total adds up to 100 wt %,
- the second front and back layers are made of a composition composed of not less than 80-100 wt % polyester which, in turn, is composed of 94-70 mol % ethylene terephthalate unit, 5-25 mol % ethylene isophthalate unit and 1-5 mol % diethylene tere(iso)phthalate unit, these units adding up to 100 mol %, and less than 20 wt % titanium oxide mixed with said polyester so that the total adds up to 100 wt %,
- said film being a biaxially stretched film,
- the amount of titanium oxide contained in said film being 20-50 wt % ;
- and
- said titanium oxide particles having a diameter of 0.1-0.5 .mu.m.
A method of producing a white film to be laminated to a metal surface, said white film comprising first and second layers which are laminated with the arrangement of second layer/first layer/second layer, wherein
- the first layer is made of a composition composed of 80-40 wt % polyester which, in turn, is composed of 100-75 mol % ethylene terephthalate unit, 0-25 mol % ethylene isophthalate unit, these units adding up to 100 mol %, and 20-60 wt % titanium mixed with said polyester so that the total adds up to 100 wt %, and
- the second layers, front and back, are made of a composition composed of 80-100 wt % polyester which, in turn, is composed of 94-70 mol % ethylene terephthalate unit, 5-25 mol % ethylene isophthalate unit and 1-5 mol % diethylene tere(iso)phthalate unit, these units adding up to 100 mol %, and less than 20 wt % titanium oxide mixed with said polyester so that the total adds up to 100 wt %,
- said film being a biaxially stretched film,
- the amount of titanium oxide contained in said film being 20-50 wt % said titanium oxide particles having a diameter of 0.1-0.5 .mu.m,
- said method comprising the steps of:
- using such resins that the intrinsic viscosities of the polyesters in the first and second layers are 0.5 or more;
- producing an unstretched sheet by molten co-extrusion of these resins;
- and
- stretching the resulting unstretched sheet longitudinally and transversely.
Dependencies are inferred from the claim text.