Toyo Boseki Kabushiki Kaisha

Atsushi Taga

Katsuya Ito

Katsufumi Kumano

Akito Hamano

Yasushi Sasaki

Katsuaki Kuze

Toshitake Suzuki

Tadashi Okudaira

Yoshifumi Yamamoto

Ichiro Kitaura

Saburo Ota

Kazuhiro Hattori

Thermal recording media each having as a support or a part thereof, a void-containing polyolefin film with a void volume of from 10 cc to smaller than 40 cc per 100 g of the film. The thermal recording media can attain the excellent advantages that they have high resolving power, they can give high-density and distinct images recorded even with very small printing energy, they have high delamination resistance, i.e., they are not easily delaminated by adhesive tape or others, and they have high opacifying power and high elasticity.

Thermal recording media and void-containing polyolefin films for use

A void-containing composite film including (A) a polyester base layer containing voids composed mainly of a polymer mixture of a polyester and a thermoplastic resin which is not compatible with the polyester and is selected from the group of polystyrene resins, polyolefin resins, polyacrylic resins, polycarbonate resins, polysulfone resins, cellulose resins, polysiloxane resins and silicone resins, and (B) at least one outer surface layer composed mainly of polyethylene terephthalate and formed on at least one side of the polyester base layer (A), the polyester base layer (A) and the at least one outer surface layer (B) being formed into a composite film by co-extrusion, followed by orientation in at least one direction, the void percentage of a surface portion having 3 .mu.m thickness from the surface of the polyester base layer (A) is 8% by volume or less, the average void percentage of the composite film is 10% to 50% by volume, and the composite film has substantially no voids at the interface between the polyester base layer (A) and the outer surface layer (B).

Void-containing composite film of polyester type

A void-containing polyester-type film is obtained by drawing a resin composition sheet consisting of a polyester, and a thermoplastic resin which is not compatible with the polyester in at least one direction. The film of this invention has a film base material consisting mainly of the polyester, fine particles consisting mainly of the thermoplastic resin which are dispersed into the film base material, and fine voids formed around the fine particles. The film of this invention has a surface layer having 3 .mu.m or more thickness, a void percentage of 4% by volume or less in an area having 3 .mu.m thickness from its surface, and an average void percentage of 8% by volume to 50% by volume. The film of this invention has excellent softeness, lightness, and hiding power, and excellent surface strength. The film can be used as a base material for a label, etc.

Void-containing polyester-type film, and its laminate

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Ohtsu, Japan

Atsushi Taga