Skc, Inc.

Bum-Sang Kim

Sang-Il Kim

Young-Jin Lee

Moon-Sun Kim

Ju-Ik Son

A copolyester resin having excellent physical properties and a low acetaldehyde content is produced by: polycondensing a mixture of terephthalic acid and isophthalic acid with a glycol in the presence of a phosphate compound to prepare a copolyester prepolymer having an intrinsic viscosity of more than 0.5 dl/g; subjecting the copolyester prepolymer to a first heat-treatment to obtain a pre-crystallized resin; and subjecting the pre-crystallized resin to a second heat-treatment, to obtain a copolyester resin having an intrinsic viscosity of 0.62 to 0.80 dl/g and a melting point of 190.degree. to 240.degree. C.

Process for the preparation of copolyester resin having low acetaldehyde

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.

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Seoul, South Korea

Bum-Sang Kim