Unitika Ltd.

Goro Araki

Hiroshi Ashihara

Takayoshi Okuzu

Ken Akamatsu

Akito Kajita

Nobuyasu Okumura

Akiko Kurosawa

Akiko Hamamoto

Atsushi Maehara

Yoshimi Ueno

Hazumu Nagano

To provide a biaxially stretched polyester resin film that has excellent properties equal to or better than those of biaxially stretched polyester film that does not use recycled raw material, and in particular that has an excellent flexural resistance in low-temperature environments. A biaxially stretched polyester resin film that characteristically satisfies both of the following properties (1) and (2): (1) in differential scanning calorimetry (DSC), after heating from 25° C. to 300° C. at a heating rate of 20° C./minute and holding for 10 minutes at 300° C., the temperature of crystallization during cooling at a cooling rate of 40° C./minute is 160° C. to 180° C.; and (2) the number of pinholes after the execution of 200 repetitive cycles of a flexural fatigue test in a −10° C. atmosphere using a Gelbo Flex Tester is not more than 10/500 cm.

Biaxially-stretched polyester resin film and manufacturing method for same

A polyester film includes a polyester (A) composed mainly of polybutylene terephthalate and a polyester (B) composed mainly of polyethylene terephthalate, wherein a mass ratio (A/B) between the polyesters (A) and (B) is 70/30 to 55/45, a dry heat shrinkage rate (B) through heat treatment at 200° C. for 15 minutes is 35% or less in any of four directions (0°, 45° 90° and 135°) on the film surface, a difference between a maximum value and a minimum value of these dry heat shrinkage rates is 5% or less, a thickness variation in the four directions is 10% or less, and a crystallization index shown in DSC measurement is 25 to 55 J/g.

Polyester film and method for producing same

A gas barrier laminate with a total thickness of 100 μm or less, including a plastic base material (I) and a gas barrier layer (II) laminated on said plastic base material, wherein (1) plastic base material (I) includes a metal-containing layer including at least one metal and a metal compound and a resin component, (2) the total content of metal and metal compound in said metal-containing layer is 0.1 to 70% by mass, (3) gas barrier layer (II) contains polycarboxylic acid, (4) metal-containing layer and gas barrier layer are laminated so that they are in direct contact with each other, and (5) gas barrier laminate is treated at a temperature of 95° C. for 30 minutes. (5) the gas barrier laminate has an oxygen transmission rate of 300 ml/(m·day·MPa) or less under a temperature of 40° C. and a humidity of 90% RH after hot water treatment for 30 minutes at 95° C.

Gas barrier laminate and method for manufacturing same

A polyester film comprises a polyester (A) composed mainly of polybutylene terephthalate and a polyester (B) composed mainly of polyethylene terephthalate, wherein a mass ratio (A/B) between the polyesters (A) and (B) is 70/30 to 55/45, a dry heat shrinkage rate (A) through heat treatment at 160° C. for 30 minutes is 20% or less in any of four directions on a film surface (0°, 45°, 90° and 135°), a difference between a maximum value and a minimum value of these dry heat shrinkage rates is 5% or less, a dry heat shrinkage rate (B) through heat treatment at 200° C. for 15 minutes is 35% or less in any of the four directions, a difference between a maximum value and a minimum value of these dry heat shrinkage rates is 5% or less, and a thickness variation in the four directions is 10% or less.

The present invention provides a mold release film including a resin layer provided on one surface of a polyester film, wherein the resin layer includes 100 parts by mass of a polypropylene-based modified polyolefin resin with the proportion of a modifying component of 1 to 10% by mass and 1 to 50 parts by mass of a cross-linking agent; the peel strength between the resin layer and a pressure-sensitive adhesive measured by bonding a rubber-based pressure-sensitive adhesive to the resin layer exceeds 3.0 N/cm; and the residual adhesion rate of a pressure-sensitive adhesive after bonding an acrylic pressure-sensitive adhesive to the resin layer is 80% or more.

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Kyoto, Japan

Goro Araki