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US 5,397,828 AGranted
Biaxially stretched polyester film
AssigneeCheil Synthetics Inc.
InventorsDae W. Ihm, Jeong L. Kim, Seung B. Jun
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AssigneeCheil Synthetics Inc.
InventorsDae W. Ihm, Jeong L. Kim, Seung B. Jun
Estimating the term…
A biaxially stretched polyester film is disclosed. The biaxially stretched polyester film comprises substantially spherical silica particles of colloidal state having average diameters ranging from approximately 20 nm to approximately 200 nm in amounts ranging from approximately 0.005% to approximately 1.0% by weight based on the total weight of the polyester; and alumina particles having average diameters ranging from approximately 50 nm to approximately 500 nm in amounts ranging from approximately 0.05% to approximately 5.0% by weight, the average diameter of the alumina particles being larger than that of the silica particles. The biaxially stretched film prepared according to the present invention has excellent surface properties such as slip property and abrasion resistance, so that the film may be used for manufacturing final products without scratches and white powders occurring thereon.
A biaxially stretched polyester film, comprising:
Dependencies are inferred from the claim text.
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Manufacture of articles or shaped materials containing macromolecular substances: manufacture of films or sheets
Shaping by stretching, e.g. drawing through a die; Apparatus therefor: characterised by the choice of materials
Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts: comprising fillers only , e.g.…
Producing flat articles, e.g. films or sheets: films or sheets
Term ended 24 Jun 2014 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates, in general, to a biaxially stretched polyester film excellent surface properties and, more particularly, to a biaxially stretched polyester film superior in slip property and abrasion resistance.
2. Description of the Prior Art
10 kg of dimethylterephthalate and 6.4 kg of ethylene glycol were fed to a reactor with a refining column. To this reactor, 7 g of manganese acetate was added as a catalyst for ester exchange reaction. The resulting reactants were heated to 200.degree. C. for 3 hours, discharging the methyl alcohol resulting from the ester exchange reaction. After ascertaining that the methyl alcohol was not produced, 4 g of antimony trioxide as a catalyst for polyester polymerization reaction and 4 g of trimethyl phosphate as a heat stabilizer were added in succession. Thereafter, spherical silica particles with an average diameter of 50 nm, dispersed in ethylene glycol were added in an amount of 1% by weight based on the total weight of the polyester to be produced. Removing the ethylene glycol produced in vacuum, the polycondensation reaction was carried at 270.degree. C. for 2.5 hour, so as to produce a polyester A.
A polyester B was obtained in the above manner used to produce the polyester A, except that alumina particles with an average diameter of 100 nm were added in an amount of 1% by weight of the polyester instead of the spherical silica particles.
Mixture of 1 kg of the polyester A, 2 kg of polyester B and 7 kg of polyester without any of the particles were dried in a dryer at 160.degree. C. for 5 hours under a vacuum condition of 300 torr with stirring the mixture.