Optical polyester film

Abstract

The invention discloses an optical polyester film. The optical polyester film comprises a first outer coating, a first surface layer, a polyester base film core layer, a second surface layer and a second outer coating which are sequentially arranged from the inside to the outside; the polyester base film core layer is obtained by biaxially stretching copolyester, and each of the first outer coating and the second outer coating contains colloidal silica; and the thickness of the polyester base film core layer is 125-200 [mu]m, the thickness of the first surface layer and the second surface layer is controlled at 6-25 [mu]m, and the thickness of the first outer coating and the second outer coating is controlled at 0.06-0.35 [mu]m. The copolyester is copolyester formed through copolymerizingone or two or more of ethylene glycol, polyethylene glycol, propylene glycol and 1,4-cyclohexanedimethanol and one or two or more of isophthalic acid, terephthalic acid and 2,6-naphthalenedicarboxylicacid. The optical polyester film has the characteristics of high transparency, good smoothness, and easiness in processing.

Description

technical field [0001] The invention relates to the technical field of optical base films for liquid crystal displays, in particular to an optical polyester film. Background technique [0002] Optical polyester film has excellent optical properties, mechanical properties, dimensional stability and heat resistance, and is widely used in optical base films for liquid crystal displays. [0003] In order to improve the anti-blocking property of the optical polyester film, in the production process of the optical polyester film, it is necessary to add silica powder as an inorganic anti-blocking agent in the polyester chips, but after the addition of the inorganic anti-blocking agent, due to the two The refractive index of silicon oxide is 1.45, while the refractive index of polyethylene terephthalate is 1.69. The light refracts and diffuses on the phase interface between the inorganic anti-blocking agent and the polyester matrix, making the optical polyester film Transparency is...

AI Technical Summary

Problems solved by technology

[0003] In order to improve the anti-blocking property of the optical polyester film, in the production process of the optical polyester film, it is necessary to add silica powder as an inorganic anti-blocking agent in the polyester chips, but after the addition of the inorganic anti-blocking agent, due to the two The refractive index of silicon oxide is 1.45, while the refractive index of polyethylene terephthalate is 1.69. The light refracts and diffuses on the phase interface between the inorganic anti-blocking agent and the polyester matrix, making the optical polyester film Transparency is destroyed to a certain extent, which seriously affects the light transmittance of polyester film, so the light transmittance of ordinary transparent polyester film is generally below 90%, so the application in the field of optical polyester film is limited

If no silica powder is added to the polyester chips, although the light transmittance of the polyester film can reach 96-98%, the coefficient of friction between the polyester films is relatively large, so it can be used in winding, unwinding, slitting and Downstream processing is more difficult, resulting in inconvenient processing

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