Multilayered polyester film
AssigneeToray Industries, Inc.
InventorsTadamasa Suzuki, Sho Tsubokura, Takuji Higashioji
Life of this patent
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Abstract
A multilayered polyester film which comprises a polyester film and, disposed on at least one surface thereof, a layer X which has a contact angel HX(1) with water of 0-60°, wherein the layer X has a degree of crystallinity C(0) of 0-30%. HX(1): Contact angle at one second after water has come into contact with layer X. A polyester film having excellent recoverability is provided by disposing a layer X on at least one surface of a polyester film, the layer X having a regulated contact angle with water and a regulated degree of crystallinity.
Claims6
A multilayered polyester film which comprises a polyester film and a layer X which is disposed on at least one surface of the polyester film, wherein
- the polyester film comprises a polyethylene terephthalate or polyethylene-2,6-naphthalenedicarboxylate film,
- the layer X
- consists essentially of a polyvinyl alcohol based resin that has a saponification degree of 30 or more and 88 or less, has a polyvinyl alcohol structure as a main chain structure and optionally contains 3 to 20 mol % of a member selected from the group comprising a 1,2-ethanediol group, a carboxyl group and a sodium sulfate group,
- has a water contact angle HX(1) of 0° or higher and 60° or lower,
- has a degree of crystallinity C(0) of 0% or more and 30% or less, and
- has an absolute value of the difference between HX(20) and HX(1)(|HX(20)−HX(1)|) of 5° or higher,
- wherein
- HX(1) is the contact angle at one second after water has come into contact with layer X and
- HX(20) is the contact angle at twenty seconds after water has come into contact with layer X, and
- the layer X is removable from the polyester film by washing with only water.
A multilayered polyester film including a polyester film and a layer Y, wherein
- the polyester film comprises a polyethylene terephthalate or polyethylene-2,6-naphthalenedicarboxylate film,
- the layer Y consists essentially of a silicone resin having a dimethylsiloxane structure as a main chain structure,
- water contact angles HY(1)(°) and HY(20)(°) in the layer Y satisfy the following formulas:
- 80≤HY(1)≤120 and
- 10≤|HY(1)−HY(20)|≤80
- wherein
- HY(1) is the contact angle at one second after water has come into contact with layer Y and
- HY(20) is the contact angle at 20 seconds after water has come into contact with layer Y, and
- the layer Y is removable from the polyester film by washing with only water.
Dependencies are inferred from the claim text.