Abstract: Disclosed is a multilayered weatherable film for a solar cell, which has superior elongation change rate, strength change rate and haze and thus is suitable for use in a solar cell, and includes a hard layer having a polyester or copolyester polymer resin and a soft layer having polybutylene terephthalate containing polytetramethylene ether glycol, which are regularly or irregularly laminated in a multilayer form.

Abstract: A double wavelength-reflective multi-layer film comprising a reflective layer part composed of at least one resin layer A and at least one resin layer B which are alternatively stacked, the resin layers A and B having refractive indexes different from each other and having a standard deviation in the thickness ranging from 6 to 30 nm, wherein the multi-layer film has an f-ratio of 0.01 to 0.99, is capable of reflecting two visible light wavelength regions in the form of one stack.

Abstract: Disclosed is a multilayered weatherable film for a solar cell, which has superior elongation change rate, strength change rate and haze and thus is suitable for use in a solar cell, and includes a hard layer having a polyester or copolyester polymer resin and a soft layer having polybutylene terephthalate containing polytetramethylene ether glycol, which are regularly or irregularly laminated in a multilayer form.

Abstract: The biaxially oriented, white polyester film of the present invention having improved flame-retardancy, covering ability, flexibility and heat-resistance comprises a polyester resin having an intrinsic viscosity of 0.4 to 0.9 dl/g, a flame-retardant which is alkylene bistetrabromophthalimide or decabromodiphenylalkane, and a fluorescent whitening agent, said polyester film being biaxially drawn at a total draw ratio of 9 or more.

Abstract: The mono or biaxially oriented polyester film of the present invention having improved flame-retardancy and processibility comprises a polyester resin having an intrinsic viscosity of 0.4 to 0.9 dl/g which contains, in its polyester chain derived from dicarboxylic acid and diol components, an incorporated repeat unit of formula (I) in an amount of 10 to 30 mol % based on the amount of dicarboxylic acid, and a flame-retardancy enhancing agent in an amount ranging from 0.05 to 5% by weight based on the weight of the polyester resin.

Abstract: The biaxially oriented, white polyester film of the present invention having improved flame-retardancy, covering ability, flexibility and heat-resistance comprises a polyester resin having an intrinsic viscosity of 0.4 to 0.9 dl/g, a flame-retardant which is alkylene bistetrabromophthalimide or decabromodiphenylalkane, and a fluorescent whitening agent, said polyester film being biaxially drawn at a total draw ratio of 9 or more.

Abstract: 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:R.sub.1 --R.sub.2 --Si--(OR.sub.3).sub.3 (I)wherein,R.sub.1 is a methacryl, an acryl, a glycidyl or an amino group;R.sub.2 is a C.sub.1-5 alkylene group; andR.sub.3 is a C.sub.1-3 alkyl group.The film has improved transparency as well as surface properties, and is especially useful as labels, window coating films, photoresists and the like.

Abstract: 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.