KR-102963778-B1 - Polyester film roll

KR102963778B1KR 102963778 B1KR102963778 B1KR 102963778B1KR-102963778-B1

Abstract

A polyester film roll formed by winding a polyester film, wherein the polyester film satisfies the following (1) and (2). (1) When heat-treated at 100°C for 5 minutes, at the film end, the absolute value of the difference between the thermal shrinkage rate in the left-slope 45° direction and the thermal shrinkage rate in the right-slope 45° direction with respect to 0° in the film length direction (MD direction) is 0.15% or less. (2) At least one side has an average surface roughness (Sa) of 8 nm or less.

Inventors

핫토리 유타

Assignees

미쯔비시 케미컬 주식회사

Dates

Publication Date: 20260512
Application Date: 20200727
Priority Date: 20190822

Claims (16)

It is made by winding a polyester film, and The thickness of the above polyester film is 19㎛ or more and 38㎛ or less, and A polyester film roll, wherein the above polyester film satisfies the following (1) and (2), and furthermore, the microscopic thickness deviation measured in the following order (a-1) to (c-1) is 0.14 μm or less, and the macroscopic thickness deviation measured in the following order (a-2) to (c-2) is 0.14 μm or less. (1) When heat-treated at 100°C for 5 minutes, at the film end, the absolute value of the difference between the thermal shrinkage rate in the left-slope 45° direction and the thermal shrinkage rate in the right-slope 45° direction with respect to 0° in the film length direction (MD direction) is 0.15% or less. (2) At least one side has an average surface roughness (Sa) of 8 nm or less. (a-1) A thickness distribution graph of the film in the TD direction is created by averaging the data measured while moving a film thickness gauge in the width direction (TD direction) along the film flowing in the length direction (MD direction). (b-1) Smooth the created graph by applying a moving average. (c-1) Calculate the thickness deviation between inflection points from the smoothed graph, and use this as the microscopic thickness deviation. (a-2) A graph of the film's thickness distribution in the TD direction is created by averaging the data measured while moving the film thickness gauge in the TD direction on a film flowing in the MD direction. (b-2) From the graph prepared, the R value (maximum value of film thickness (R max ) - minimum value of film thickness (R min )) is calculated over the entire width at intervals of 200 mm in the TD direction of the film. (c-2) The maximum value of the total R value sampled over the entire width at intervals of 200 mm is taken as the macroscopic thickness deviation.
In Article 1, The above polyester film is additionally a polyester film roll satisfying (3) and (4) below. (3) The thermal shrinkage rate in the MD direction is 0.3% or less when heat-treated at 100℃ for 5 minutes. (4) The heat shrinkage rate when heat-treated at 100°C for 5 minutes is 0.2% or less in the TD direction of the film.
In Article 1, The above polyester film is a polyester film roll containing a titanium compound.
In Article 1, A polyester film roll having an intrinsic viscosity (IV) of the polyester constituting the surface layer of the above polyester film, which is 0.65 dl/g or higher.
In Article 1, The above polyester film is a polyester film roll having a surface layer (A) containing particles on at least one side.
In Article 1, The above polyester film is a polyester film roll having a laminated structure of three or more layers.
In Article 5, The above surface layer (A) is a polyester film roll containing organic and/or inorganic particles with an average particle size of 0.1 to 0.5 μm.
In Article 5, The above polyester film is a polyester film roll having a surface layer (C) having both an average surface roughness (Sa) and a maximum peak height (Sp) smaller than the surface layer (A).
In Article 8, The above surface layer (C) is a polyester film roll containing 900 to 6000 ppm of particles with an average particle size of 0.05 to 0.2 μm.
In Article 8, The above surface layer (C) is a polyester film roll containing a titanium compound.
In Article 5, The above surface layer (A) comprises an antimony compound and/or a titanium compound, and is a polyester film roll having a content of said antimony compound of 100 ppm or less.
In any one of paragraphs 1 to 11, A polyester film roll having a release layer on at least one side of the polyester film.
In Article 12, Polyester film roll used as a support for a ceramic green sheet in the manufacturing process of a multilayer ceramic capacitor.
In Article 12, A polyester film roll used as a support for a ceramic green sheet in the manufacturing process of automotive ceramic capacitors.
In any one of paragraphs 1 to 11, The above polyester film is a polyester film roll that is a biaxially stretched polyester film.
In Article 12, The above polyester film is a polyester film roll that is a biaxially stretched polyester film.

Description

Polyester film roll The present invention relates to a polyester film roll having excellent smoothness and improved heat shrinkage characteristics, in particular, a polyester film roll suitable as a support for a process release film used in the manufacturing process of a multilayer ceramic capacitor. Recently, with the electrification of automobiles and the increased functionality of smartphones, the miniaturization and capacitance of Multi-Layered-Ceramic-Capacitors (MLCCs) are progressing. Multilayer ceramic capacitors are manufactured as follows. First, a ceramic green sheet (dielectric sheet) is produced by coating a ceramic slurry containing a ceramic component and a binder resin onto a release film and drying it, and an electrode is printed onto it by a screen printing method or the like to form an internal electrode, and after drying, the printed ceramic green sheet is peeled off from the release film and a number of such green sheets are stacked. After pressing the laminated green sheets to integrate them, they are cut into individual chips. Afterwards, the internal electrode and dielectric layer are sintered in a kiln to manufacture a multilayer ceramic capacitor. In order to miniaturize and increase the capacitance of MLCCs, the thinning of ceramic green sheets is progressing. When a ceramic green sheet is thinned, if there are minute protrusions on the surface of the release film acting as a carrier film, pinholes or the like occur in the ceramic green sheet due to this. For this reason, high surface smoothness is required for the release film. Conventionally, as a support for this type of release film, Patent Document 1 discloses a release film for manufacturing a green sheet, wherein the release film comprises a substrate having a first surface and a second surface, a smoothing layer provided on the side of the first surface of the substrate, and a release agent layer provided on the side of the smoothing layer opposite to the substrate, wherein the smoothing layer is formed by heating and curing a composition for forming a smoothing layer comprising a thermosetting compound having a mass average molecular weight of 950 or less, and wherein the arithmetic mean roughness (Ra1) of the outer surface of the release agent layer is 8 nm or less, and furthermore, the maximum protrusion height (Rp1) of the outer surface of the release agent layer is 50 nm or less. In addition, Patent Document 2 discloses a release polyester film having excellent surface smoothness and, in particular, having few fine defects on the film surface, wherein the number of indentation defects with a depth of 0.5 μm or more is 5 or less, and at least the centerline average roughness (SRa) of one side surface is 15 to 35 nm, and the 10-point average roughness (SRz) is 1000 nm or less. As the thinning of green sheets progresses significantly, higher lamination precision is required when stacking these thinned green sheets in multiple layers. Consequently, the flatness of release films has become increasingly important, leading to efforts to control thermal wrinkling. As a film of this type, Patent Document 3 discloses a polyester film roll formed by winding a polyester film, wherein the slack defects present in the polyester film are less than 5 per 100 m². In addition, Patent Document 4 discloses a biaxially stretched polyester film having a thickness of 5 to 20 μm, wherein the difference in refractive index between the length direction and the width direction is -0.030 to 0.015, the thermal shrinkage rate is 0.8 to 2.0% in the length direction and -0.5 to 1.0% in the width direction, the change in orientation angle with respect to the film width direction is 0 to 20° per 1m, and the change in the difference between the thermal shrinkage rate in the +45° direction and the thermal shrinkage rate in the -45° direction with respect to the length direction is 0 to 0.25% per 1m. This biaxially stretched polyester film is used as a deposition polyester film. Patent Document 4 describes that, by the above configuration, a deposited polyester film with excellent gas barrier properties, such as oxygen or water vapor, can be obtained even when using a wide film roll with improved productivity. FIG. 1 is a schematic plan view showing the 45° inclination direction regarding the heat shrinkage of a polyester film roll related to the present invention. Figure 2 is a schematic plan view showing the phenomenon of oblique shrinkage after heating. Polyester film roll The polyester film roll of the present invention (hereinafter referred to as "the roll") is formed by winding a polyester film (hereinafter referred to as "the film"). The roll is a film wound on a core such as a paper tube, metal tube, or plastic tube, and is preferably 0.2 m or more in width, more preferably 0.3 m or more, particularly preferably 1.0 m or more, and most preferably 1.2 m or more. The upper limit of the film width is not particularly limited, but is 2.0 m. In addit