Diafoil Company, Ltd.

Nec Corporation

Daifoil Company, Limited

Yujiro Fukuda

Shigeo Utsumi

Kichinojyo Tomitaka

Shinobu Suzuki

Narihiro Masuda

Tomoyuki Kotani

Toshifumi Takisawa

Yoshinori Sato

Hiromi Yamashita

Takatoshi Miki

A nonmagnetic single-component developer is manufactured by admixing fluoropolymer fine powder to a toner containing a thermoplastic binder resin and a coloring pigment in an amount of 0.1 to 10% by weight of the resultant mixture. The fluoropolymer fine powder has a weight-average particle size smaller than that of the toner, and the amount of particles each having a size not larger than 3 .mu.m and contained in the fluoropolymer fine powder is not larger than 30% by weight. The method may be such that classifying by particle size is effected to the mixture of the toner and the fluoropolymer fine powder to remove smaller particles present therein.

Method for manufacturing a nonmagnetic single-component developer

Disclosed is an electrostatic image developer with negative chargeability which can give clear image quality and high image density by virtue of the toner, contained therein, having a small-diameter or a high content of fine toner particle, surface-modified with a fluoropolymer fine particle. The toner primarily consists of a polyester binder resin and a coloring pigment, and the toner has an average particle size of 9 .mu.m or less, or a .ltoreq.4 .mu.m fine toner particle content of at least 0.1% by weight. The toner is surface-modified with 0.1 to 10% by weight of a fluoropolymer fine particle having an average particle size smaller than that of the toner, in such a way that the ratio of the surface area of the fluoropolymer fine particle to that of the toner may be 10.sup.-3 to 10.sup.-1. Use of a polytetrafluoroethylene fine particle is preferred among other fluoropolymers, and a combination of the surface modification with the fluoropolymer fine particle and that with an inorganic fine particle is further preferred.

Electrostatic image developer

The present invention relates to a process for producing a biaxially oriented polyester film. The process is carried out using the following steps: (a) stretching an amorphous film substantially comprising polyethylene terephthalate 1.2 to 4.0 times in the machine direction by single-stage or multi-stage process to obtain a film having an index of birefringence of 1.times.10.sup.-3 to 2.5.times.10.sup.-2 ; (b) stretching the thus obtained film 1.1 to 3.5 times in the machine direction by single-stage or multi-stage process of 3.0.times.10.sup.-2 to 8.0.times.10.sup.-2 without cooling the film to the glass transition temperature thereof or below; (c) cooling the thus obtained film to the glass transition temperature thereof or below; (d) heating the thus obtained film to the glass transition temperature or higher and stretching the film in the machine direction by a single-stage or multi-stage process at a stretching ratio which brings the overall stretching ratio of 4.0 to 9.0 times; and (e) stretching the thus obtained film at least 3.2 times in the transverse direction. According to the method of the present invention, a biaxially oriented polyester film which is excellent in thickness uniformity and flat and slippery properties can be easily produced and high-speed production thereof is possible, therefore, the present invention has a great industrial value.

Process for producing biaxially oriented polyester film

Disclosed herein is a moldable biaxially stretched polyester film having a tensile strength at 100% elongation (F.sub.100), measured in an atmosphere of 150.degree. C., of 0.5 to 7 kg/mm.sup.2. The biaxially stretched polyester film according to the present invention is excellent in moldability.

Moldable biaxially stretched polyester film

A shrinkable copolyester film having shrinkage of not less than 30% in the direction (main shrink direction) of either the machine direction or the transverse direction after 5 min treatment in an air oven at 100.degree. C., a shrinkage of not more than 20% in the other direction perpendicular to the main shrink direction after 5 min treatment in an air oven at 100.degree. C., an initial shrinkage stress (F.sub.0) of not more than 2000 g/mm.sup.2 in the main shrink direction during the course of 5 sec after dipped in a silicone oil of 75.degree. C., a shrinkage stress (F.sub.20) of not less than (F.sub.0 -100) g/mm.sup.2, after 20 sec dipping in a silicone oil at 75.degree. C., and a glass transition temperature of 35.degree. to 65.degree. C., is disclosed. The shrinkable copolyester film of the present invention is excellent in shrinkage properties, i.e., substantially free from wrinkles, distortion of film and uneven shrinkage, and is suitable for a shrinkable label for a PET bottle, etc.

Shrinkable copolyester film

A shrinkable polyester film having a sufficient shrinkage, a sufficient resistance to solvent for printing ink, a shrinking property not to cause wrinkles, a warm water resistance sufficient for preventing wrinkles, slack and whitening is disclosed herein. The shrinkable polyester film of the present invention may be used as labels for various vessels such as glass bottle, heat-resistant PET bottle and non heat-resistant PET bottle.

Shrinkable polyester film

Disclosed herein is a polyester shrinkable film. The film according to the present invention can provide extremely excellent durability and long-time storability of contents of a container in labelling and shrink packaging use.

Polyester shrinkable film containing benzotriazole

Disclosed in this invention is a shrinkable polyester film having a shrinkage of not less than 40% after 5-minute treatment in a 100.degree. C. air oven in one of the machine and transverse directions, and a shrinkage of not more than 15% after 5-minute treatment in a 100.degree. C. air oven and a maximum shrinkage stress of not more than 50 g/mm.sup.2 at 40.degree. to 100.degree. C. in the other direction. The shrinkable film of this invention has the excellent shrink characteristics and are substantially free from wrinkling, curling at the end and non-uniformity of shrinkage when the film is shrunk, so that it is suited for use as a label film and has a high industrial value.

Disclosed herein is a biaxially oriented polyester film for magnetic recording media, containing uniformly carbon black particles and having the following specific properties: ##EQU1## wherein T.sub.900 represents a light transmittance of the film at a wavelength of 900 nm, Ra represents an average surface roughness of the film n.sub.1 represents the number of protuberances of 0.81 to 1.08 .mu.m in height existing on the surface of the film per film area of 25 cm.sup.2, and n.sub.2 represents the number of protuberances of more than 1.08 .mu.m in height existing on the surface of the film per film area of 25 cm.sup.2.

Polyester film for magnetic recording media

A shrinkable film for packaging excellent in the heat-sealing property and the shrinking property is disclosed. This shrinkable film is obtained by stretching a film of a mixture comprising 100 to 30 weight parts of a crystalline polyester (A), which comprises mainly terephthalic acid and 1,4-cyclohexane dimethanol and has a heat of crystalline melting of not less than 3 cal/g and a melting point in the range of 200.degree. to 310.degree. C., and 0 to 70 weight parts of a polyester (B) comprising terephthalic acid and/or 2,6-naphthalene dicarboxylic acid as the dicarboxylic acid constitutional unit and ethylene glycol and/or 1,4-butylene glycol as the glycol constitutional unit. The mixture of the polyester (A) and polyester (B) has a good handling property in drying. The shrinkable film for packaging of the present invention can be produced without any difficulty in drying and shows the ratio of shrinkage of 40 to 90% after 5-minute heat treatment at 100.degree. C. in either of the longitudinal and transverse directions, the ratio of shrinkage or expansion of not more than 15% after 5-minute heat treatment at 100.degree. C. in the other direction and the haze of not more than 10% at a film thickness of 35 .mu.m.

Shrinkable polyester film for packaging

Disclosed herein is a process for producing a polyphenylene sulfide film, which comprises melt-molding polyphenylene sulfides in a sheet-like form from a die, casting the thus obtained sheet-like form onto a chilled drum on which an adhering liquid has been applied, while closely contacting the sheet-like form with the chilled drum surface by an electrostatic pinning method.

Process for producing polyphenylene sulfide film

There is disclosed a transparent slippery biaxially stretched polyester film characterized by satisfying the relations represented by the following formulas after being biaxially stretched and heat-set:

Growing community of inventors

Machida, Japan

Yujiro Fukuda