A biaxially stretched polyester film and a method for producing the same are provided. The biaxially stretched polyester film includes a polyester resin base layer and a matte layer formed on the polyester resin base layer. The matte layer has a total weight of 100 wt %, and the matte layer includes: (1) 50 to 95 wt % of a polyester resin matrix, an intrinsic viscosity of the polyester resin matrix being between 0.5 and 0.8 dL/g; (2) 0.01 to 5 wt % of a high viscosity polyester resin, an intrinsic viscosity of the high viscosity polyester resin being between 0.9 and 1.1 dL/g; (3) 0.3 to 40 wt % of a plurality of filler particles, the filler particles having an average particle size of between 0.15 and 10 μm.

The present invention relates to a flexible plastic film, and more specifically to a flexible plastic film having excellent flexibility while exhibiting high hardness. According to the present invention, the flexible plastic film exhibits flexibility, bending property, high hardness, scratch resistance and high transparency, and hardly has a risk of damaging the film even in a state of being warped for a long period of time, and thereby can be usefully applied to flexible mobile devices, display devices, front face and display unit of various instrument panels, and the like.

A biaxially stretched polyester film and a method for producing the same are provided. The biaxially stretched polyester film includes a polyester resin base layer and a matte layer formed on the polyester resin base layer. The matte layer has a total weight of 100 wt %, and the matte layer includes: (1) 50 to 95 wt % of a polyester resin matrix, an intrinsic viscosity of the polyester resin matrix being between 0.5 and 0.8 dL/g; (2) 0.01 to 5 wt % of a high viscosity polyester resin, an intrinsic viscosity of the high viscosity polyester resin being between 0.9 and 1.1 dL/g; (3) 0.3 to 40 wt % of a plurality of filler particles, the filler particles having an average particle size of between 0.15 and 10 m.

A problem addressed by the present invention is to provide a low-friction member which does not easily lose low-friction properties thereof even when used for a relatively long period. The low-friction member LS according to the present invention is consisting of at least lubricating materials PL, PS and a polyimide resin MR. The low-friction member has a surface roughness Rsk or 0.500 or more and the surface exposure ratio of the lubricating materials of 15.0% or more. It is particularly preferred that the surface roughness Rsk be in a range of 0.0900 (inclusive) to 0.1400 (inclusive), and the surface exposure ratio of the lubricating materials be 35.0% or more. It is preferred that the lubricating materials be a fluororesin. The low-friction member thus has the property of not losing the low-friction properties thereof easily even when used for a relatively long period.

The present invention relates to a flexible plastic film, and more specifically to a flexible plastic film having excellent flexibility while exhibiting high hardness. According to the present invention, the flexible plastic film exhibits flexibility, bending property, high hardness, scratch resistance and high transparency, and hardly has a risk of damaging the film even in a state of being warped for a long period of time, and thereby can he usefully applied to flexible mobile devices, display devices, front face and display unit of various instrument panels, and the like.

The present invention relates to a flexible plastic film, and more specifically to a flexible plastic film having excellent flexibility while exhibiting high hardness. According to the present invention, the flexible plastic film exhibits flexibility, bending property, high hardness, scratch resistance and high transparency, and hardly has a risk of damaging the film even in a state of being warped for a long period of time, and thereby can be usefully applied to flexible mobile devices, display devices, front face and display unit of various instrument panels, and the like.

The present invention relates to a flexible plastic film, and more specifically to a flexible plastic film having excellent flexibility while exhibiting high hardness. According to the present invention, the flexible plastic film exhibits flexibility, bending property, high hardness, scratch resistance and high transparency, and hardly has a risk of damaging the film even in a state of being warped for a long period of time, and thereby can be usefully applied to flexible mobile devices, display devices, front face and display unit of various instrument panels, and the like.

A problem addressed by the present invention is to provide a low-friction member which does not easily lose low-friction properties thereof even when used for a relatively long period. The low-friction member LS according to the present invention is consisting of at least lubricating materials PL, PS and a polyimide resin MR. The low-friction member has a surface roughness Rsk or 0.500 or more and the surface exposure ratio of the lubricating materials of 15.0% or more. It is particularly preferred that the surface roughness Rsk be in a range of 0.0900 (inclusive) to 0.1400 (inclusive), and the surface exposure ratio of the lubricating materials be 35.0% or more. It is preferred that the lubricating materials be a fluororesin. The low-friction member thus has the property of not losing the low-friction properties thereof easily even when used for a relatively long period.

A building board, particularly a gypsum board, can include a first cover sheet, a second cover sheet, and a core disposed between the first and second cover sheets. The core can include gypsum, microsilica, and an additive. The microsilica can no greater than 2.7 wt. % of the building board. The additive can include a polysiloxane material and be no greater than 0.25 wt. % of the building board.