Polyester film for sealing backside of solar cell
AssigneeToyobo Co., Ltd.
InventorsYoshitomo Ikehata, Akira Shimizu, Shiro Hamamoto, Jun Inagaki, Shinji Sawazaki
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Abstract
The present invention provides a polyester film for sealing the backside of solar cell having excellent light reflectivity and durability and good electric insulation. A polyester film for sealing the backside of solar cell having a light reflectance at 550 nm wavelength of 50% or more and containing 3 to 50% by mass of inorganic fine particles, characterized in that acid value of the film is 1 to 30 eq/ton and limiting viscosity of the film is 0.60 to 0.80 dL/g.
Claims14
A polyester film for sealing a backside of a solar cell, wherein the polyester film has a light reflectance at 550 nm wavelength of 50% or more,
- contains 3 to 50% by mass of inorganic fine particles,
- has an acid value of 1 to 30 eq/ton,
- has an in-face variation of light reflectance to a mean value of light reflectance of 5% or less, and
- has a limiting viscosity of 0.60 to 0.80 dL/g,
- wherein the film is obtained by preparing a master batch comprising a polyester resin and inorganic fine particles;
- subjecting the master batch to solid-phase polymerization;
- and, after that, forming a mixture by pouring a polyester resin containing no inorganic fine particles and the master batch into an extruder and melt extruding the mixture, wherein a difference between a limiting viscosity of the master batch and a limiting viscosity of the polyester resin to be mixed therewith is 0.15 dL/g or less.
Dependencies are inferred from the claim text.