Skc, Inc.

Young-Jin Lee

Sang-Il Kim

Kwang-Hyung Lee

Bum-Sang Kim

Nam-Il Kim

Joon-Hee Han

Gwan-Hyung Lee

Moon-Sun Kim

Jeong-Wook Seo

Wan-Sup Shim

Il-Cheon Song

Seung-Soo Woo

Sang-il Kim

Seong-Ill Cheong

Je-Wung Lee

Hyo-Sup Kim

Ju-Ik Son

A biaxially oriented polyester film comprises: 0.01 to 4 wt % of .gamma., .delta.- .theta.-alumina or a mixture thereof having an average particle diameter ranging from 0.005 to 3 .mu.m and a Mohs hardness of 6 or more; 0.05 to 5 wt %, based on the amount of the alumina employed, of a silane coupling agent of the following formula (I); and, optionally, 0.01 to 4 wt % of spherical silica particle having an average particle diameter ranging from 0.005 to 3 .mu.m:

Polyester film comprising alumina and silane coupling agent

Apparatus for preparing a polyester resin by polymerizing a monomer produced by transesterifying a dicarboxylic acid component with a diol component while removing the vapor containing diols and other low molecular weight compound released during the polymerization, which comprises:

Apparatus for the preparation of polyester resin

A process for preparing a thermoplastic resin film having uniform physical and chemical properties includes extending a thermoplastic resin sheet in a longitudinal direction so that the crystallization energy of the longitudinally extended sheet is 20 J/g or more to give a longitudinally extended sheet, extending the longitudinally extended sheet in a transverse direction to give a biaxially extended film, and heat treating the biaxially extended film to give the resin film.

Process for the preparation of thermoplastic resin film

A polyester film having improved surface and mechanical properties is prepared by transesterifying and polycondensing a dialkyl ester of an aromatic dicarboxylic acid and a glycol to give a polyester resin, and melt-extruding and drawing the polyester resin to give the polyester film, wherein calcium carbonate, surface treated with a titanate coupling agent by adding the titanate coupling agent to a glycol slurry containing 20 to 60 wt % of ball or rugby ball shaped vaterite type calcium carbonate having an average diameter ranging from 0.01 to 3 .mu.m is incorporated during the preparation process of the polyester resin as a slip agent.

Process for the preparation of polyester film

A biaxilly oriented polymer film having improved surface properties, anti-static property and printability is prepared from a mixture of 70 to 99 parts by weight of a polyester resin containing not less than 60% by weight of repeating units of ethylene terephthalate and having an intrinsic viscosity ranging from 0.4 to 0.9 dl/g, and 1 to 30 parts by weight of polyolefin resin having a melting flow index ranging from 1.5 to 25 g/10 min, wherein said polyester film further comprises 0.1 to 25 parts by weight of an inorganic particle.

Polymeric film with paper-like characteristics

A white-colored porous polymer film having elongated spherical pores, which is characterized in that said pores exposed on a surface created by cutting the film along longitudinal direction satisfy the following formulae, possesses a low density, good surface and mechanical property and good processability: ##EQU1## wherein, P.sub.L,90 is an average length of longer axes of 90% or more of the exposed pores;

White-colored polymer film

A polymeric film, which comprises 100 parts by weight of a polyester resin having an intrinsic viscosity ranging from 0.4 to 0.9 dl/g, 5 to 50 parts by weight of a polyolefin resin having a melt flow index ranging from 1.0 to 25 g/10 min and/or a styrene resin having a melt flow index ranging from 1.5 to 20 g/10 min, and 0.01 to 1.0 part by weight of a metal sulfonate of the following formula (I) having an acid value of 1.0 mg KOH/g or less, has an excellent antistatic property, printability, a good appearance and touchiness, as well as an improved film characteristics such as bulk density and heat stability.

Polymeric film and process for the preparation thereof

The present invention relates to a biaxially oriented polyester film comprising the inorganic particulate slip agent of aluminum hydroxide or .THETA.-alumina having an average diameter ranging from 0.1005 to 3 .mu.m and Mohs hardness of 6 or more, in an amount ranging from 0.01 to 4 wt % based on the weight of the polyester, which has improved surface properties, abrasion resistance and scratch resistance.

Biaxially oriented polyester film containing an aluminum hydrate

A process for preparing a biaxially oriented thermoplastic resin film which comprises: extending a thermoplastic resin sheet in a longitudinal and a transverse directions to form a film thereof, and heat treating the film under a temperature gradient descending from both edges to the center of the film along the transverse direction within a zone defined by the following formula (1) by employing a heater which is located over the film with an angle .theta. of the following formula (3) from said both edges to the center of the film to produce a thermoplastic resin film having uniform physical end chemical properties in the transverse direction:

A biaxially oriented polyester film having improved surface properties, scratch resistance and abrasion resistance comprises the particulate slip agents of a calcium carbonate having an average particle diameter ranging from 0.01 to 3 .mu.m, alumina having an average particle diameter ranging from 0.005 to 3 .mu.m and a Mohs' hardness of 8 or more and a melamine formaldehyde condensate having an average particle diameter ranging from 0.01 to 3 .mu.m, wherein each of the slip agents is in an amount ranging from 0.01 to 4 wt. % based on the weight of the polyester. The film is useful in manufacturing condensers, medical articles, photographic films, packaging and labelling materials and, particularly, magnetic recording media.

Biaxially oriented polyester film and process for the preparation thereof

A polyester film having excellent heat resistance and insulation property is produced by the inventive process which comprises: melt-extruding a polyester resin into a sheet, extending the sheet to shape it into a film and treating the film thermally to heat-set, wherein the polyester resin has an intrinsic viscosity of 0.7 to 0.75 dl/g and other portions which satisfy formula (1) and the thermal treatment is carried out so that formula (2) is satisfied:

Process for the preparation of heat resistant polyester film

A biaxially oriented polyester film with excellent levelling property is produced by the inventive process which comprises: (a) melt-extruding and extending biaxially a polyester resin to shape it into a film; (b) treating the film thermally under a condition that formulae (1), (2) and (3) are satisfied; and (c) relaxing the film at a temperature range of Tm-60.degree. C. to Tm-140.degree. C. during the step (b):

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Anyang-si, South Korea

Young-Jin Lee