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US 5,401,559 AGranted
Biaxially oriented thermoplastic resin film
AssigneeToray Industries, Inc.
InventorsKatsuya Okamoto, Koichi Abe, Syoji Nakajima
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AssigneeToray Industries, Inc.
InventorsKatsuya Okamoto, Koichi Abe, Syoji Nakajima
Estimating the term…
Disclosed is a biaxially oriented thermoplastic resin film formed by laminating a layer A composed of a thermoplastic resin A containing particles on at least one surface of a layer B composed of a thermoplastic resin B. The film has a specified ratio t/d of the thickness of the layer A "t" to the mean diameter of the particles contained in the thermoplastic resin A "d", a specified number of protrusions having a diameter of not less than 0.7 .mu.m and not more than 2.6 .mu.m among protrusions existing on the surface of the layer A and a specified ratio L/S of a number S of protrusions having a smaller diameter to the number L of protrusions having a diameter in the above range. An excellent winding property when the film is wound and an excellent dubbing resistance when the film is used for a video tape can be obtained.
A biaxially oriented thermoplastic resin film formed by laminating a layer A composed of a thermoplastic resin A containing particles on at least one surface of a layer B composed of a thermoplastic resin B, characterized in that the ratio t/d of the thickness "t" of said layer A to the mean diameter "d" of the particles contained in said thermoplastic resin A is in the range of 0.1 to 5, the number of protrusions having a diameter of not less than.0.7 .mu.m and not more than 2.6 .mu.m among protrusions existing on the surface of said layer A is in the range of 100/mm.sup.2 to 10,000/mm.sup.2 and the ratio L/S of the number S of protrusions having a diameter of not less than 0.2 .mu.m and less than 0.7 .mu.m to the number L of protrusions having a diameter of not less than 0.7 .mu.m and not more than 2.6 .mu.m is in the range of 1/50 to 1/10,000, and the total reflection Raman crystallization index of the surface of layer A is not more than 20 cm.sup.-1.
A biaxially oriented thermoplastic resin film formed by laminating a layer A composed of a thermoplastic resin A containing at least two kinds of particles having mean diameters different from each other on at least one surface of a layer B composed of a thermoplastic resin B, characterized in that the ratio t/d of the thickness "t" of said layer A to the mean diameter "d" of the particles contained in said thermoplastic resin A is in the range of 0.1 to 5, the number of protrusions having a diameter of not less than 0.7 .mu.m and not more than 2.6 .mu.m among protrusions existing on the surface of said layer A is in the range of 100/mm.sup.2 to 10,000/mm.sup.2 and the ratio Pw/Qw of the weight content Pw of particles having the smallest mean diameter among said at least two kinds of particles contained in said thermoplastic resin A to the weight content Qw of particles having the largest mean diameter among said at least two kinds of particles contained in said thermoplastic resin A is in the range of 4 to 400, and the total reflection Raman crystallization index of the surface of layer A is not more than 20 cm.sup.-1.
Dependencies are inferred from the claim text.