Abstract: A film to be laminated onto a metal plate and molded, which includes a first copolyester including ethylene-2,6-naphthalene dicarboxylate as a main recurring unit or a blend of the first copolyester and a second copolyester including terephthalate as a main recurring unit. Both the first copolyester and the blend contain diethylene glycol in an amount of 0.05 to 8 mol %. This film has a water extraction of 0.5 mg/inch.sup.2 or less and a center line surface roughness (Ra) of 4 to 30 nm.

Abstract: A laminate polyester film to be laminated onto metal plate and molded comprises the first layer made from copoly(ethylene-terephthalate/isophthalate) having a melting point of 205 to 250.degree. C. and a second layer made from a polyester (i) comprising ester units of an aromatic dicarboxylic acid component, an aliphatic dicarboxylic acid component and aliphatic diol components, (ii) containing a titanium compound soluble in the polyester in an amount of 30 to 200 ppm in terms of elemental titanium and (iii) having one or two melting point(s) in the range of 170 to 245.degree. C., and has the maximum peak temperature of loss elastic modulus of higher than 47.degree. C. and 85.degree. C. or lower. This laminate polyester film is suitably used for application such as metal cans for juice and other refreshing drinks that are handled in a cooled state.

Abstract: A biaxially oriented laminated polyester film comprising:(A) a first thin polyester layer formed from an aromatic polyester containing two kinds of inert fine particles having different size and(B) a second polyester layer formed from an aromatic polyester, on at least one surface of which the above first thin polyester layer is present. This biaxially oriented laminated polyester film is is excellent in lubricity, abrasion resistance and scratch resistance and is particularly useful as a base film for a magnetic recording medium.

Abstract: A biaxially oriented laminated polyester film comprising a first thin polyester layer containing large-diameter inert particles and small-diameter inert particles; a second polyester layer containing large-diameter inert particles; and a third thin polyester layer containing large-diameter inert particles and small-diameter inert particles, the biaxially oriented laminated polyester film satisfying the following expression (1), ##EQU1## wherein: W.sub.1 is the content (wt. %) of the large-diameter inert particles in the first thin polyester layer, W.sub.2 is the content (wt. %) of the large-diameter inert particles in the second polyester layer, D.sub.13 is a total of the thickness (.mu.m) of the first thin polyester layer and the thickness (.mu.m) of the third thin polyester layer, and D.sub.2 is the thickness (.mu.m) of the second polyester layer. This film is useful as a base film for a magnetic medium.

Abstract: A biaxially oriented polyester film for magnetic recording media, which comprises:(A) 0.05 to 1.0% by weight of .theta.-aluminum oxide or mixed (.alpha.+.gamma.) aluminum oxide having an average particle diameter in the range of from 0.02 to 0.3 .mu.m and a specific surface area in the range of from 50 to 120 m.sup.2 /g, and(B) 0.01 to 1.5 % by weight of inert organic particles having an average particle diameter which is in the range of from 0.1 to 1.5 .mu.m and greater than the average particle diameter of the aluminum oxide.

Abstract: A biaxially oriented polyester film for magnetic recording media improved in slipperiness, shaving resistance and scratch resistance by protrusions formed on the film surface, namely, a polyester film for magnetic recording media wherein the film is a biaxially oriented polyester film which contains (I) heat resistant high molecular particles having an average particle size of 0.3 to 1.5 .mu.m in 0.001 to 0.5% by weight of the polyester, and(II) alumina particles having an independent existence rate of 80% or more and an average particle size of 0.06 to 0.2 .mu.m in 0.05 to 1.0% by weight of the polyester and/or colloidal silica particles having an independent existence rate of 80% or more and an average particle size of 0.3 .mu.m or less in 0.05 to 2.0% by weight of the polyester;wherein the distribution curve, in the range where the height (x : .mu.m) is 0.05 .mu.m or more and the number of the protrusions (y : per mm.sup.2) is 30 protrusions/mm.sup.

Abstract: A biaxially oriented polyester film for magnetic recording media, which comprises:(A) 0.05 to 1.0% by weight of .theta.-aluminum oxide or mixed (.alpha.+.gamma.) aluminum oxide having an average particle diameter in the range of from 0.02 to 0.3 .mu.m and a specific surface area in the range of from 50 to 120 m.sup.2 /g, and(B) 0.01 to 1.5% by weight of inert particles having an average particle diameter which is in the range of from 0.1 to 1.5 .mu.m and greater than the average particle diameter of the aluminum oxide.