JP4088843B1 - Polyethylene terephthalate resin film roll and method for producing the same - Google Patents

Abstract

Disclosed is a polyethylene terephthalate-based resin film roll that has good practicality over the entire length of the roll regardless of the conditions of the post-processing in the heat treatment step during post-processing.
A polyethylene terephthalate-based resin film roll is provided with a sample cutout section for each length obtained by dividing the film winding length into nine equal parts from the end of film winding, and the final cutout section within 2 m from the beginning of film winding. When a total of 10 sample cutout portions are provided, the HS150 at the left and right ends of each cutout portion is a value within a predetermined range, and the difference between the HS150 at the left and right ends is within the predetermined range. It is adjusted to be the value of. In addition, the amount of variation in the longitudinal direction of the HS 150 at both the left and right ends is adjusted to be a value within a predetermined range.
[Selection figure] None

Description

  The present invention relates to a polyethylene terephthalate-based resin film roll, and particularly relates to a polyethylene terephthalate-based resin film roll having excellent processing characteristics.

  Biaxially oriented polyethylene terephthalate resin films are used as various optical films because of their excellent transparency, dimensional stability, and chemical resistance. In particular, it is suitably used for applications such as a prism lens sheet base film, an antiglare film base film, and a CRT anti-fracturing film for LCDs that require strength and dimensional stability. Such a biaxially stretched polyethylene terephthalate resin film is stretched in the longitudinal direction between rolls having a difference in rotational speed, and then stretched in the width direction with the end of the film being held in a tenter, and heat-set. To be manufactured. In this case, since the longitudinal direction cannot be relaxed at the end of the film in the width direction at the time of heat fixing, the heat shrinkage rate in the longitudinal direction varies depending on the position in the film width direction. Therefore, in the slit roll corresponding to the edge of the mill roll, the thermal contraction rate at the one end edge in the width direction (thermal contraction rate in the longitudinal direction) is larger than the thermal contraction rate at the other end edge. When such a slit roll is utilized, the film passability deteriorates in a heat treatment step during post-processing. In some cases, the film is rubbed and scratched by the frame of the machine base and others. In addition, adjusting the post-processing conditions in order to prevent the film from being damaged is a very time-consuming operation. For the above reasons, only slit rolls other than the edge of the mill roll can be used as optical applications without adjusting the post-processing conditions.

  On the other hand, the demand for wide slit rolls has been increasing in order to reduce post-processing costs. In order to collect a wide slit roll, it is desirable to increase the width of the mill roll. However, if the width of the mill roll is widened, it becomes difficult to keep the temperature in the width direction uniform during heat setting. That is, the temperature fluctuation range is large both in terms of position and time. Therefore, in order to increase the width of the mill roll, it is necessary to finely adjust the hot air blowing amount and the like to maintain the temperature uniformity in the width direction of the heat fixing device. However, even when fine adjustments such as the amount of blown hot air are made, it is not possible to reduce the difference in thermal shrinkage at the film edge to a level sufficient to improve the film passability in post-processing.

  Until now, as a method of reducing the difference in thermal shrinkage in the width direction of the film, the applicant has increased the temperature in the width direction of the film from the center to the end by the following means, thereby relaxing the edge. A method of bringing the amount close to the relaxation amount in the central portion has been proposed (Patent Document 1). That is, in the heat fixing process of the film, (1) covering a plenum duct (hot air outlet) arranged vertically at a certain interval with respect to the film traveling direction, and (2) shielding the film. The width of the plate is gradually widened according to the film traveling direction side.

JP 2001-138462 A

  Further, as a method for reducing the difference in the heat shrinkage rate in the width direction of the film, the applicant attached discontinuous shielding plates to the five plenum ducts in the film heat setting step, and from each plenum duct, per unit time Discloses a method of increasing the amount of hot air impinging on the end by increasing the speed of air blown from the plenum duct while keeping the amount of hot air blown to the outside (Patent Document 2).

JP 2002-79638

  However, in the method of Patent Document 1 in which a continuous shielding plate is simply put on the plenum duct, the heat treatment in post-processing (coating and drying) is improved to some extent at about 120 ° C. The film relaxation is still inadequate. That is, in the above method, the passability when heat treatment at about 160 ° C. is performed for a relatively long time (10 to 60 seconds) (formation of a hard coat film, etc.) is not improved so much. Therefore, when post-processing is performed at a high temperature for a long time, the conditions must be adjusted, but such adjustment may not be possible.

  In addition, in the method of Patent Document 1, since temperature irregularity occurs in the heat setting zone, when producing a long film (mill roll) of 1,000 m or more, there is a difference in thermal shrinkage rate in the width direction of the film. A big part arises.

  Further, in the method of Patent Document 2, since the air volume of each plenum duct is constant, the wind speed is different for each plenum duct, so that turbulent flow occurs in the heat fixing device. Therefore, the temperature in the heat setting zone is greatly inhomogeneous, which is inconvenient. Moreover, the effect of reducing the difference in the heat shrinkage rate in the width direction due to the shielding plate was not satisfactory.

  An object of the present invention is to provide a polyethylene terephthalate-based resin film roll that solves the above-described problems and has good film permeability in the heat treatment step during post-processing over the entire length of the roll, and a method for producing the same.

Among the present inventions, the configuration of the invention described in claim 1 is the biaxially stretched polyethylene terephthalate slit so that the length is 300 m or more and 8,000 m or less and the width is 0.7 m or more and 2.2 m or less. Refractive index in a direction that forms an angle of 45 degrees with the winding direction of the wound film and a refractive index in a direction that forms an angle of 135 degrees with the winding direction of the wound film Is a biaxially stretched polyethylene terephthalate-based resin film roll having a difference Δn _ab of 0.015 or more and 0.060 or less, and an initial sample cut-out portion is provided within 2 m from the end of film winding, By providing a final cutout part within 2 m from the beginning, and providing a sample cutout part for each length that is divided into 9 parts between the first and final cutout parts When provided with a total of 10 samples cutout portion is to satisfy the following requirements (1) to (3).
(1) When each sample is cut out from a position within 50 mm from one end edge and a position within 50 mm from the other end edge in the roll width direction, and the two samples are heated at 150 ° C. for 30 minutes. HS150, which is the heat shrinkage rate in the film winding direction, and when the heat shrinkage difference, which is the difference between the HS150, is obtained, the heat shrinkage difference in all cutout portions is 0.1% or less. (2) In each of the cutout portions, when a sample is cut out from a position within 50 mm from one end edge and a position within 50 mm from the other end edge in the width direction of the roll, and HS150 is obtained for each sample, HS150 of the samples at both end edges in all cutout parts is 0.7% or more and 2.0% or less 3) the amount of variation in the HS150 at one end edge in the width direction of the roll obtained at each cut-out portion, and the variation amount of HS150 other end edge in the width direction of the roll obtained in each cutout portion, both 0. It must be between 05% and 0.20%

The structure of the invention described in claim 2 is that, in the invention described in claim 1, the wound biaxially stretched polyethylene terephthalate resin film has a thickness of 70 μm or more and 400 μm or less.

The structure of the invention described in claim 3 is a manufacturing method for manufacturing the biaxially stretched polyethylene terephthalate resin film roll described in claim 1, wherein the raw material resin is melt-extruded from an extruder. A film forming process for forming an unstretched sheet, a biaxial stretching process for biaxially stretching the unstretched sheet obtained in the film forming process in the longitudinal direction and the transverse direction, and heat setting for heat-fixing the film after biaxial stretching. And the heat setting step is performed in a heat setting device that satisfies the following requirements (4) to ( 7 ).
(4) A plurality of wide plenum ducts for blowing out hot air are arranged vertically opposite to the traveling direction of the film. (5) Shielding for shielding hot air outlets from the plurality of plenum ducts. (6) The dimension of each shielding plate in the traveling direction of the film is adjusted to be substantially the same as the dimension of the outlet of each plenum duct in the traveling direction of the film. The dimension in the width direction of the film is adjusted so as to become gradually longer with respect to the film traveling direction.
(7) Keep the plenum duct wind speed constant in each heat setting zone.

  The structure of the invention described in claim 4 is the invention described in claim 3, wherein the biaxial stretching step stretches the film in the longitudinal direction and then stretches in the transverse direction and performs the transverse stretching. There is an intermediate zone between the zone and the heat fixing device in which no wind is blown.

  The structure of the invention described in claim 5 is the invention described in claim 3 or claim 4, wherein the heat setting device is divided into a plurality of heat setting zones and adjacent heat setting zones. In other words, the product of the temperature difference and the wind speed difference is set to be 250 ° C. · m / s or less.

  The polyethylene terephthalate-based resin film roll of the present invention has excellent film passability during post-processing such as prism lens processing, hard coat processing, and AR processing, and therefore can be post-processed with a very high yield. Therefore, the polyethylene terephthalate-based resin film roll of the present invention can be used for optical films such as a base film for prism lens sheets, a base film for backlights, a base film for AR films, an anti-crushing film for CRT, and a post-processing heat treatment. It can be suitably used as a processing film which is carried out at a high temperature (about 160 ° C.) for a relatively long time (10 to 60 seconds).

  The film constituting the polyethylene terephthalate-based resin film roll of the present invention contains ethylene glycol and terephthalic acid as main components. Other dicarboxylic acid components and glycol components may be copolymerized as long as the object of the present invention is not impaired. Examples of the other dicarboxylic acid components include isophthalic acid, p-β-oxyethoxybenzoic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-dicarboxybenzophenone, bis- (4-carboxyphenylethane), adipine Examples include acid, sebacic acid, 5-sodium sulfoisophthalic acid, cyclohexane-1,4-dicarboxylic acid, and the like. Examples of the other glycol component include propylene glycol, butanediol, neopentyl glycol, diethylene glycol, ethylene oxide adducts such as bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. In addition, oxycarboxylic acid components such as p-oxybenzoic acid can also be used.

  As a polymerization method of such polyethylene terephthalate (hereinafter simply referred to as PET), for example, the following method can be used. (1) A direct polymerization method in which terephthalic acid and ethylene glycol and, if necessary, other dicarboxylic acid components and diol components are reacted directly. (2) A transesterification method in which a dimethyl ester of terephthalic acid (including a methyl ester of another dicarboxylic acid if necessary) and ethylene glycol (including another diol component if necessary) are subjected to a transesterification reaction.

  When the film roll of the present invention is formed of PET, the intrinsic viscosity (IV) of the raw material PET is preferably in the range of 0.45 to 0.70 dl / g. It is preferable that the intrinsic viscosity of the PET raw material is 0.45 or more because the stretchability and tear resistance of the film are improved. In addition, when the intrinsic viscosity is 0.70 dl / g or less, the filtration pressure becomes moderately low, and high-precision filtration is possible. In addition, IV of resin raw material is calculated | required with the following methods, for example.

[Intrinsic viscosity (IV)]
After the PET ground sample is dried, it is dissolved in a mixed solvent of phenol / tetrachloroethane = 60/40 (weight ratio), and a solution having a concentration of 0.4 (g / dl) is obtained at 30 ° C. using an Ostwald viscometer. Measure the flow time and the flow time of the solvent alone. From these time ratios, IV is calculated using the Huggins equation, assuming that the Huggins constant is 0.38. The intrinsic viscosity is also expressed as [η].

  Moreover, when forming the film roll of this invention by PET, the range of 3-30 eq / t is preferable and, as for the acid value (AV) of PET raw material, it is more preferable in it being 5-25 eq / t. It is preferable for the acid value to be 3 eq / t or higher because the polymerization rate is moderately increased and the production efficiency is improved. Moreover, it is preferable for the acid value to be 30 eq / t or less because hydrolysis is suppressed and an appropriate degree of polymerization is obtained. The acid value of the resin raw material is determined by the following method, for example.

[Acid value]
After pulverizing the raw material, it is dissolved in benzyl alcohol, and after adding chloroform, neutralization titration with a sodium hydroxide solution is performed to calculate the equivalent of sodium hydroxide per 1 ton of PET.

Furthermore, when the film roll of the present invention is formed of PET, it is desirable that the raw material resin (including the recycled raw material) does not contain foreign matters. In particular, when producing a film roll for optical applications, high-precision filtration is performed when melt-extruding so that the number of foreign matters having a diameter of 20 μm or more present per 1 m ^{2 of the} film after film formation is 10 or less. It is preferable to adjust. When performing high-precision filtration, it is preferable to use a filter medium having an initial filtration efficiency of 90% or more and a filtration particle size of 15 μm or less. Here, the initial filtration efficiency refers to a numerical value measured by ANSI / B93.36-1973. Note that the number of foreign substances in the raw material is obtained by the following method, for example.

[Number of foreign objects]
An enlarged image of the melted raw material chip is taken using a phase contrast microscope and a CCD camera, and the number of foreign matters is counted using an image processing apparatus.

The polyethylene terephthalate-based resin film roll of the present invention is a slit roll obtained by slitting a mill roll once produced in a wide width, and Δn _ab (a refractive index in a direction forming an angle of 45 degrees with the winding direction of the wound film) The difference (absolute value) between the winding direction of the wound film and the refractive index in the direction forming an angle of 135 degrees is limited to 0.015 or more and 0.060 or less. That is, in the case of a distorted slit roll having Δn _ab of 0.015 or more, the above-described problem of “distortion (that is, physical property difference in the width direction)” occurs. Further, in the case of a slit roll having Δn _ab of 0.060 or less, the heat shrinkage rate difference or the like can be adjusted so as to satisfy the requirements of the present invention. In addition, Δn _ab in the present invention means Δn _ab which is the larger of the two values when Δn _ab is measured at a position within 50 mm from one edge of the slit roll and a position within 50 mm from the other edge.

  The polyethylene terephthalate-based resin film roll of the present invention has a cut-out portion set by a method to be described later. At each cut-out portion, a position within 50 mm from one end edge in the roll width direction and within 50 mm from the other end edge. Each sample was cut out from each position, and for the two samples, HS150, which is the heat shrinkage rate in the film winding direction when heated at 150 ° C. for 30 minutes, was obtained, and the difference in heat shrinkage rate, which is the difference between the HS150, was obtained. The difference in heat shrinkage rate between all cutout parts must be 0.1% or less.

  That is, the polyethylene terephthalate-based resin film roll of the present invention has a total of 10 heat shrinkage ratio differences (difference in HS150 at both end edges in the film sample cut out from each cutout portion) obtained in a total of 10 cutout portions. Must be 0.1% or less. It is preferable that the difference in thermal shrinkage at each cut-out portion is 0.1% or less because the film can be easily passed in post-processing. Further, the difference in heat shrinkage rate between the cutout portions is more preferably 0.08% or less, and particularly preferably 0.06% or less. In addition, although the heat shrinkage rate difference in each cutout part is preferably as low as possible, it is considered that about 0.05% is the limit in consideration of measurement accuracy.

A film sample used for the measurement of HS150 is cut out from 10 cutout portions provided by the following procedure.
(1) The first sample cutout is provided within 2 m from the end of winding of the film.
(2) A value obtained by dividing the length of the wound film by 9 (hereinafter, referred to as “cut section interval”) is calculated.
(3) A sample cutout portion is provided at a position within 10 m before and after each “cutout portion interval” from the end of winding of the film.
(4) A final cutout portion is provided within 2 m from the start of film winding.

  The cutting of the sample will be described more specifically. For example, when a film having a length of 500 m is wound on a roll, the first sample (1) is cut within 2 m from the end of winding of the film. The sample is cut out in the film winding direction (longitudinal direction) including the position within 50 mm from one end edge and the position within 50 mm from the other end edge in the roll width direction (direction orthogonal to the film winding direction). Direction) and a rectangular shape so as to have a side along the width direction (not diagonally cut). Next, the “cutting portion interval” is calculated by dividing the winding length of the film by 9. Note that the “cutout interval” is calculated to the unit of “1 m”. Therefore, as described above, when the winding length is 500 m, 2 m from the winding end where the first cutout portion can be provided and 2 m from the winding start where the final cutout portion can be provided are subtracted from 500 m in advance, and the remaining 496 m is obtained. 55 m divided into nine equal parts is defined as “interval of cutout portions”. Subsequently, the second sample (2) is cut off at a distance of 55 ± 10 m from the winding end of the film. Thereafter, similarly, samples are sequentially cut out at intervals of 55 m on the winding start side to obtain a total of 10 samples. That is, the first sample (first sample) is cut out at a position within 2 m from the end of winding, the second sample is cut out at a position near 57 m from the end of winding, and the third sample is cut at a position near 112 m from the end of winding. Similarly, the fourth to ninth samples are cut out at every position 55 m away from the end of winding, and the final sample (10th sample) is cut out at a position within 2 m from the start of winding.

  Furthermore, the polyethylene terephthalate-based resin film roll of the present invention has a position within 50 mm from one end edge in the width direction of the roll and within 50 mm from the other end edge when the sample cut-out part is set by the above-described method. When the sample is cut out from each position and the HS150 is obtained for each sample, the HS150 of the samples at both ends at all cutout portions must be 0.7% or more and 2.0% or less. is there.

  That is, in the polyethylene terephthalate-based resin film roll of the present invention, the HS150 values (total 20 HS150 values) at both ends of the cut film sample are 0.7% or more in a total of 10 cut portions. It is necessary to be 2.0% or less. It is preferable that the value of HS150 at both ends of the film sample cut out from each cut-out portion is 2.0% or less because the film can be easily passed in post-processing. Further, the value of HS150 at both ends of the film sample cut out from each cut-out portion is more preferably 1.5% or less, and particularly preferably 1.2% or less. In addition, although the value of HS150 in the both ends of the film sample cut out from each cutout part is so preferable that it is low, about 0.7% is considered to be a minimum.

Furthermore, the polyethylene terephthalate-based resin film roll of the present invention has a fluctuation amount of HS150 on one end edge side in the width direction of the roll obtained in each cutout part, and HS150 on the other end edge side in the roll width direction obtained in each cutout part. It is necessary that the fluctuation amount of each be 0.05% or more and 0.20% or less .

That is, the polyethylene terephthalate-based resin film roll of the present invention has HS150 on one end edge side (one end edge side in the width direction) and HS150 on the other end side (the other end edge side in the width direction) for 10 films cut out from each cutout portion. , The fluctuation amount (difference between the highest value and the lowest value) of the ten HS 150 on the one end edge side is 0.20 % or less, and the fluctuation amount of the ten HS 150 on the other edge side is 0. 0 % . It is necessary to be 20 % or less.
It is preferable that the fluctuation amount of 10 HS 150 on any one edge side is 0.20 % or less because the film can be easily passed during post-processing. Further, the amount of variation of HS150 10 pieces of each end edge is still preferable to be 0.18% or less, more preferable to be 0.016% or less, and particularly preferably 0.15% or less. Incidentally, the amount of variation of HS150 10 pieces of each end edge is preferably as low as possible, taking into account the measurement accuracy, Ru limit der about 0.05%.

  The polyethylene terephthalate-based resin film roll of the present invention is obtained by subjecting an unstretched sheet (unstretched laminated film or unstretched laminated sheet) obtained by melting and extruding a raw material polyethylene terephthalate-based resin to the longitudinal direction (longitudinal direction) and the transverse method. It can be manufactured by biaxially stretching in the (width direction), winding up in a roll shape, and heat-setting by a method described later.

  As a method for obtaining an unstretched sheet, a method in which a polyethylene terephthalate resin melted at about 285 ° C. is melt-extruded into a sheet shape, and the molten sheet is cooled and solidified with a cooling roll can be suitably employed. Note that. It is desirable that the polyethylene terephthalate resin pellets used in the extruder are sufficiently dried. Furthermore, a polyethylene terephthalate resin containing fine particles for the purpose of imparting slipperiness can also be used suitably.

  As a method for bringing the sheet-like melt into close contact with the rotary cooling drum, for example, a method using an air knife or a method of applying an electrostatic charge can be preferably applied. In those methods, the latter is preferably used.

  In addition, as a method of cooling the sheet-like melt, for example, a method of bringing the sheet surface into contact with the cooling liquid in the tank, a method of applying a liquid that evaporates with a spray nozzle to the sheet air surface, and blowing a high-speed air flow A method of cooling may be used in combination. The unstretched sheet thus obtained is stretched in the biaxial direction to obtain a film.

  As a method of stretching the film in the biaxial direction, the obtained unstretched sheet is stretched in the longitudinal direction by a roll or a tenter-type stretching machine, and then stretched in the width direction orthogonal to the first-stage stretching direction. A method can be mentioned. The stretching temperature in the longitudinal direction is preferably 75 to 120 ° C., and the stretching ratio in the longitudinal direction is 2.5 to 4.5 times, preferably 3.0 to 4.3 times. A stretching temperature in the longitudinal direction of 75 ° C. or higher is preferable because the film is difficult to break. Moreover, since it becomes difficult to produce the thickness spot of the obtained film at 120 degrees C or less, it is preferable. A stretching ratio in the longitudinal direction of 2.5 times or more is preferable in terms of the flatness of the film. Moreover, it is preferable that it is 4.6 times or less because the frequency of fracture due to orientation decreases.

  In the case of stretching in the width direction, the stretching temperature needs to be 80 to 210 ° C, and preferably 130 to 200 ° C. A stretching temperature in the width direction of 80 ° C. or higher is preferable because the film is difficult to break. Moreover, at 210 degrees C or less, it is preferable at the point of the planarity of the obtained film. The draw ratio in the width direction is 3.0 to 5.0 times, preferably 3.6 to 4.8 times. If the draw ratio in the width direction is 3.0 times or more, it is preferable because uneven thickness of the obtained film hardly occurs. It is preferable that the draw ratio in the width direction is 5.0 times or less because the breaking frequency due to orientation decreases.

  Subsequently, heat setting is performed. The temperature in the heat setting treatment step is preferably 180 ° C. or higher and 240 ° C. or lower. When the temperature of the heat setting treatment is 180 ° C. or higher, the absolute value of the heat shrinkage ratio is preferably reduced. Moreover, it is preferable that the temperature of the heat setting treatment is 240 ° C. or lower because the film is hardly opaque and the frequency of breakage is reduced. A suitable heat setting method will be described later.

  It is effective to control the heat shrinkage rate, particularly the heat shrinkage rate in the width direction, by narrowing the guide rail of the gripping tool by the heat setting process. The temperature for the relaxation treatment can be selected in the range from the heat setting treatment temperature to the glass transition temperature Tg of the polyethylene terephthalate resin film, and is preferably (heat setting treatment temperature) −10 ° C. to Tg + 10 ° C. The width relaxation rate is preferably 1 to 6%. If it is less than 1%, the effect is small, and if it is 6% or less, it is preferable in terms of the flatness of the film.

  Here, although the method of extending | stretching to the width direction after extending | stretching first to a longitudinal direction was described, the extending | stretching order may be reverse. In addition, the longitudinal stretching and the lateral stretching may be performed in one stage, or may be performed in two or more stages. In addition, as described above, in addition to the method of sequentially biaxial stretching, it is also possible to employ a simultaneous biaxial stretching method in which stretching is performed simultaneously in the longitudinal direction and the transverse direction. However, in order to satisfy the characteristics of the present invention, it is important to take optimum temperature conditions and longitudinal and lateral draw ratios, and it is sufficient that the finally obtained film characteristics satisfy the requirements of the present invention.

  Further, in order to impart functionality to the film, a polyethylene terephthalate resin film having a multilayer structure of two or more layers may be used. When the surface on which the slippery layer or the easy adhesion layer is applied is the A layer, the opposite surface is the B layer, and the other surface is the C layer, the layer structure in the film thickness direction is A / B, A / C / B or Configurations such as A / C / E / D / B are conceivable. The layers A to E may be made of the same material or different materials.

  The thickness of the film constituting the polyethylene terephthalate resin film roll of the present invention is preferably 70 μm or more and 400 μm or less when used for optical applications.

  In addition, the film roll width is preferably 0.7 m or more, and more preferably 1.0 m or more, from the viewpoint of ease of handling. On the other hand, the upper limit of the width of the film roll is determined by the size of the post-processing apparatus, but at present, 2.2 m is considered the maximum width, more preferably 2.0 m or less, and 1.5 m or less. More preferably. In addition, the winding length of the film roll is preferably 8,000 m or less and more preferably 7,000 m or less when the film has a thickness of about 70 μm from the viewpoint of ease of winding and handling. . When the film has a thickness of about 400 μm, it is preferably 1,200 m or less, and more preferably 1,100 m or less. Therefore, when the thickness of the film is in the middle of 70 to 400 μm, it is preferable to set the film length to be 300 m or more and 8,000 m or less. As the take-up core, usually, paper of 3 inches, 6 inches, 8 inches, etc., a plastic core or a metal core can be used.

  The polyethylene terephthalate resin film of the present invention may be a single layer or a film having a laminated structure of two or more layers. Also, it is preferable that various coatings are applied at the time of film formation for the purpose of imparting easy adhesion or slipperiness to one side or both sides of a biaxially stretched polyethylene terephthalate resin film that does not contain fine particles with emphasis on transparency. Used.

  Moreover, in the polyethylene terephthalate-type resin film which comprises the film roll of this invention, microparticles | fine-particles can be added as needed. Examples of the fine particles added at that time include known inorganic fine particles and organic fine particles. Furthermore, in the resin forming the film, various additives as necessary, for example, waxes, antioxidants, antistatic agents, crystal nucleating agents, viscosity reducing agents, heat stabilizers, coloring pigments, An anti-coloring agent, an ultraviolet absorber and the like can be added. It is preferable to add fine particles to the polyethylene terephthalate resin in the present invention to improve the slipperiness of the polyethylene terephthalate resin film. Examples of the fine particles include inorganic particles such as silica, alumina, titanium dioxide, calcium carbonate, kaolin, and barium sulfate. Examples of the organic fine particles include acrylic resin particles, melamine resin particles, silicone resin particles, and crosslinked polystyrene particles. The average particle diameter of the fine particles can be selected as necessary within a range of 0.05 to 2.0 μm.

  As a method of blending the above particles into the polyethylene terephthalate resin film, for example, it can be added at the stage of producing the polyethylene terephthalate resin, but preferably at the esterification stage or after completion of the transesterification reaction, the polycondensation reaction It may be added as a slurry dispersed in ethylene glycol or the like at the stage before the start to proceed the polycondensation reaction. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyethylene terephthalate resin raw material, or a dried particle and a polyethylene terephthalate system using a kneading extruder It can be performed by a method of blending with a resin raw material.

  Furthermore, the polyethylene terephthalate resin film constituting the film roll of the present invention can be subjected to corona treatment, coating treatment, flame treatment, etc. in order to improve the adhesion of the film surface.

  Next, the preferable manufacturing method for obtaining the polyethylene terephthalate-type resin film roll of this invention is demonstrated.

  Usually, the heat setting process of the stretched film is carried out in a heat setting device in which a plurality of plenum ducts having long hot air outlets are arranged perpendicular to the longitudinal direction. In such a heat fixing device, “circulation of hot air” is performed in order to improve the heating efficiency. Air in the heat fixing device is sucked by a circulation fan installed in the heat fixing device, the temperature of the sucked air is adjusted, and the air is again discharged from the hot air outlet of the plenum duct. In this manner, “hot air circulation” of “hot air blowing → suction by circulation fan → temperature adjustment of sucked air → hot air blowing” is performed.

  Further, as described above, the difference in thermal shrinkage in the width direction of the film roll (difference between HS 150 at the edge of one end and HS 150 at the edge of the other end) is that relaxation of the edge of the film does not occur when heat fixing is performed. It occurs because it is enough. As shown in FIG. 1, in the heat setting process, a continuous large shielding plate S is placed on the central portion of the hot air outlets 2, 2,... Of each plenum duct 3, 3,. See) improves the passage when short films are processed at relatively low temperatures (eg 120 ° C.) in post-processing. However, the permeability in a long film and the permeability when heat treatment in post-processing is performed at a high temperature (for example, 160 ° C.) are not improved.

  In order to understand why the method shown in FIG. 1 does not improve the "passability in a long film" or "passability when heat-setting treatment in post-processing is performed at a high temperature", The analysis of the phenomenon in the heat setting device was done in detail. As a result, when a continuous large shielding plate that spans multiple plenum ducts is placed over the hot air outlet of the plenum duct, the flow of hot air is restricted by the shielding plate, and the above-mentioned "hot air circulation" is performed smoothly. As a result, it was found that temperature turbulence (temperature hunting phenomenon) occurred in the heat fixing device.

Since the above-mentioned “temperature hunting phenomenon” causes insufficient thermal relaxation at the edge of the film, the present inventors have made “passability in a long film” and “heat setting treatment in post-processing high temperature. It was speculated that the “passability” would worsen. Therefore, the present inventors can improve the “passability in a long film” and the “passability when a heat setting process in post-processing is performed at a high temperature” by smoothing “circulation of hot air”. I thought that. And as a result of trial and error in order to grasp the relationship between the temperature air volume condition of the heat setting device, the covering mode of the shielding plate, and the film permeability in the post-processing, the following (1) By taking measures, there was a tendency that “passability in a long film” and “passability when heat-setting treatment in post-processing was performed at a high temperature” were improved. And based on the knowledge, as a result of further trial and error, the present inventors have taken the following means (1) and then taken the following means (2) and (3). The inventors have found that it is possible to obtain a film roll having good permeability, and have come up with the present invention.
(1) Adjustment of temperature and air volume of plenum duct in heat fixing device (2) Adjustment of shut-off condition of hot air outlet of plenum duct in heat fixing device (3) Heat cutoff between stretching zone and heat fixing device Each of the above-described means will be described sequentially.

(1) Adjusting the temperature and air volume of the plenum duct in the heat setting device In order to heat and cool the heat setting process step by step, the heat setting device is generally divided into several sections (heat setting zones) with different temperatures. I know. In the production of the film roll of the present invention, each plenum duct is designed such that the product of the temperature difference and the wind speed difference between adjacent heat setting zones of the heat setting device is 250 ° C. · m / s or less. It is indispensable to adjust the temperature and air volume of the hot air blown out from. For example, when the heat setting device is divided into first to third heat setting zones, the product of the temperature difference and the wind speed difference between the first zone and the second zone, and between the second zone and the third zone. Both products of the temperature difference and the wind speed difference are adjusted to be 250 ° C. · m / s or less. Thus, by adjusting the temperature and air volume of hot air, “circulation of hot air” becomes smooth. When combined with a method of attaching a discontinuous shielding plate, which will be described later, to the hot air outlet, the “temperature hunting phenomenon” is effectively suppressed. Thus, for the first time, it is possible to obtain a long film having good passability when the heat setting treatment in the post-processing is performed at a high temperature.

  If the product of the temperature difference and the wind speed difference between adjacent heat setting zones is 250 ° C. · m / s or less (for example, the temperature difference between adjacent heat setting zones is set to 20 ° C. The temperature difference between adjacent heat setting zones is set to 10 m / s), “circulation of hot air” in the heat setting device is smoothly performed, and “temperature hunting phenomenon” is effectively suppressed. This is preferable. In addition, if the product of the temperature difference and the wind speed difference between adjacent heat setting zones is 250 ° C. · m / s or less, the heat setting zone downstream from the heat setting zone upstream as an accompanying flow caused by the passage of the film The temperature difference of the air flowing into Therefore, it is preferable because the temperature in the width direction of the downstream heat setting zone is stabilized. The product of the temperature difference and the wind speed difference is preferably 200 ° C. · m / s or less, and more preferably 150 ° C. · m / s or less. Further, as in Patent Document 2, if the air volume of each plenum duct is made constant and the wind speed of each plenum duct is made different, a “temperature hunting phenomenon” occurs. In the present invention, the “temperature hunting phenomenon” is effectively suppressed by making the wind speed in each zone constant.

(2) Adjustment of Plenum Duct Cut-off Conditions in Heat Fixing Device In the production of the film roll of the present invention, individual plenum ducts are not attached as shown in FIG. It is necessary to attach the rod-shaped shielding plates S, S,... So as to shield the hot air outlets (nozzles) 2, 3,. By using such a discontinuous shielding plate, “circulation of hot air” is performed smoothly. Moreover, it is preferable not to attach the same length of the shielding plate to each plenum duct, but to gradually increase the length of the shielding plate from the inlet of the heat fixing device to the outlet (film passing direction) (see FIG. 1). . Thus, by adjusting the length, the temperature of the hot air exposed to the film edge is adjusted, and the elimination of distortion at the film edge is promoted. The material of the shielding plate may be any material as long as it can withstand the temperature of the heat fixing device and does not stain the film or adhere the film, but it is the same material as the plenum duct from the viewpoint of thermal expansion. Is preferably used. Further, in order to suppress the difference in thermal contraction rate of the film edge portion due to the shielding plate to the level of the present invention, it is preferable that the number of shielding plates is large, and it is desirable that the number is 15 or more.

(3) Blocking of heating between the stretching zone and the heat setting device (installation of an intermediate zone)
The biaxially stretched polyethylene terephthalate resin film roll is usually heat-set after being longitudinally and laterally stretched. In the production of the film roll of the present invention, it is desirable to install an intermediate zone in which active hot air is not blown between the zone that is longitudinally and transversely stretched and the heat setting device that is heat set. As a result, the heat is completely shut off between the stretching zone and the heat setting device. More specifically, when a strip-shaped paper piece is hung between the stretching zone and the heat setting device in the state where the drawing zone and the heat setting device are in the same condition as in film production, the paper piece is almost completely removed. It is preferable to block the hot air from the stretching zone and the heat fixing device so as to hang down in the vertical direction. Note that such an intermediate zone may be surrounded by a housing, or may be provided so that a continuously manufactured film is exposed. When the hot air is sufficiently blocked in the intermediate zone, the shielding effect of the shielding plate in the heat fixing device is exhibited, and good film passage during post-processing can be obtained.

  As described above, by adopting the above methods (1) to (3), the “hot air circulation” in the heat fixing device can be smoothly executed, and the “temperature hunting phenomenon” can be suppressed. As a result, it is possible to sufficiently promote relaxation in the longitudinal direction at the edge of the width direction, such as “passability in a long film” and “passability when heat setting treatment in post-processing is performed at a high temperature”. Can be improved. In the above description, the method of suppressing the “temperature hunting phenomenon” by smoothly executing “circulation of hot air” in the heat fixing device in which the plenum duct is installed. The above description discloses the technical idea of how the film roll of the present invention can be obtained by applying thermal energy to the film at the production level. It can be easily carried out by a method different from the above-described method, and the film roll of the present invention can be obtained by a different method. In other words, even with another type of heat fixing device, the "circulation of hot air" is smoothly executed to suppress the "temperature hunting phenomenon" and then sufficiently relaxed in the longitudinal direction at the edge of the width direction. Improve "passability in long film" and "passability when heat-setting treatment in post-processing is performed at a high temperature" like the film roll of the present invention by applying sufficient heat energy to the film It is possible to obtain a finished film roll.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the embodiments of the examples, and can be appropriately changed without departing from the spirit of the present invention. . In addition, the evaluation method of a film characteristic is as follows.

[Δn _ab ]
The sample film was cut out from the edge part (area | region within 50 mm from an edge) of a film roll. The cut sample film was left for 2 hours or more in an environment of 23 ° C. and 65% RH. For each sample sample, using an “Abbe refractometer 4T type” manufactured by Atago Co., Ltd., the refractive index (na) in _a direction that forms an angle of 45 degrees with the film winding direction, and the film winding direction with 135 degrees The refractive index (n _b ) in the direction forming the angle (that is, the direction forming the angle of 45 degrees and the direction forming the angle of 90 degrees) was measured. The absolute value of the difference between these two refractive indexes is Δn _ab, and Δn _ab = | n _a −n _b | Δn _ab was measured for both edge portions of the film roll, and the larger one was taken as Δn _ab of the present invention.

[Heat Shrinkage Ratio of Film] The first sample cut-out portion is provided within 2 m from the end of winding of the film, and the sample cut-out portion is provided for each length obtained by dividing the film winding length into nine from the end of film winding. By providing the final cutout portion within 2 m from the beginning of winding, a total of 10 sample cutout portions were provided for one film roll. For each cut-out part, a sample film having a width of 20 mm and a length of 250 mm is cut out along the film winding direction from the left and right edge parts (the part within 50 mm from the edge) of the film roll, and the left edge part and the right edge part Ten sample films were obtained for each part. Each sample film was marked at intervals of 200 mm, placed in a heating oven adjusted to 150 ° C., and the amount of heat shrinkage was measured in accordance with JIS C-2318.

[Passability of film]
The flatness of the film after the heat treatment was evaluated by the following method. As a heat treatment step, a coater having a distance between two rolls of 1,900 mm was used, the temperature was set to 100 ° C. or 160 ° C., and the furnace tension was set to 100N. Next, two rolls are horizontally arranged so that the roll interval is 2,000 mm, and further, the iron bar is positioned at the center position of the two rolls at a position 30 mm below the common tangent of the roll upper surface. Arranged. The film passed through the heat treatment step was passed between two rolls under a tension of 98N. When the film was allowed to pass through, it was marked as ◯ when the film was not in contact with the iron bar, and x when it was in contact with the iron bar. These steps were performed continuously, and it was visually confirmed whether or not the film contacted the iron bar.

In addition, Table 1 shows the film forming conditions of the film rolls in Examples and Comparative Examples.

[Example 1]
Polyethylene terephthalate ([η] = 0.60) containing 0.03% by mass of silica particles (manufactured by Fuji Silysia Chemical Ltd., Silicia 310) as an additive was dried until the water content became 50 ppm or less. The dried polyethylene terephthalate was charged into the hopper of an extruder and melted at a temperature of 285 ° C. in the extruder. The molten resin was filtered in a extruder using a stainless steel filter medium (nominal filtration accuracy: 90% of particles having a size of 10 μm or more). Next, the melted resin was extruded into a sheet form from a T-shaped die, and wound around a casting drum whose surface was adjusted to 30 ° C. using an electrostatic application casting method. By cooling and solidifying with a casting drum, an unstretched sheet having a thickness of 1,380 μm was obtained.

  The above-mentioned unstretched sheet is heated to 100 ° C. by a heated roll group and a near infrared heater, and then continuously stretched 3.5 times in the longitudinal direction with a roll group having a difference in peripheral speed. It was. Next, the end of the uniaxially stretched film was gripped with a clip, led to a hot air zone heated at 130 ° C., and continuously stretched 4.0 times in the width direction. Furthermore, after heat-setting at 238 ° C. by the method described later, 1.7% lateral relaxation treatment was performed at 225 ° C. By winding this in a roll shape, a biaxially oriented polyester film roll (mill roll) in which a film having a thickness of 100 μm and a width of 3,300 mm was wound up by 6,500 m was produced. While rewinding the mill roll, both ends are removed by 150 mm each, and the remaining part is slit at three equal intervals in the width direction, and by removing approximately 200 m from the surface layer (winding end portion) of the mill roll, Six slit rolls having a width of 1,000 mm and a winding length of 3,010 m were obtained. Of the six slit rolls obtained as described above, using the slit roll corresponding to one edge side of the mill roll (the right side when viewed from the upstream to the downstream of the film flow), the characteristics of the film and the film roll Was evaluated. The evaluation results are shown in Table 4.

[Heat setting]
The said heat setting process was performed with the heat setting apparatus which has a structure shown in FIG. The heat setting device is divided into four heat setting zones called first to fourth zones. Eight plenum ducts a to x are provided in the first to third zones, respectively. Eight plenum ducts are also provided in the fourth zone. Each plenum duct is vertically installed at 400 mm intervals with respect to the film traveling direction so as to be perpendicular to the film traveling direction. Hot air is blown to the stretched film from the hot air outlet (nozzle) of the plenum duct.

  In Example 1, discontinuous rod-shaped shielding plates S, S,... Were attached to hot air outlets of 15 plenum ducts a to o in the manner shown in FIG. FIG. 4 shows a state where the heat fixing device having the shielding plates S, S... Attached to the hot air outlets of the plenum ducts a to o is viewed from above. The longitudinal center of each of the attached shielding plates S, S... Is set so as to substantially coincide with the center of the width of the film passing through the heat fixing device. Further, the length of each shielding plate S, S... (The dimension in the width direction of the produced film) was set so as to gradually increase from the inlet to the outlet of the heat fixing device. Table 2 shows the shielding ratio of the hot air outlets of each of the plenum ducts a to o (the shielded area of the hot air outlet by the shielding plate / the area of the hot air outlet). In addition, let the shielding aspect by the shielding board in Example 1 be "A aspect."

  Table 3 shows the adjustment values of the temperature and wind speed in the first to fourth zones of the heat setting device in Example 1. In addition, as for the temperature conditions of the 1st-4th zone of the heat setting apparatus of Example 1, and the wind speed conditions, the product of the temperature difference between adjacent heat setting zones and a wind speed difference is 250 degrees C * m / s or less. Set to. The temperature and wind speed conditions in the first to fourth zones in Example 1 are defined as “I condition”.

[Example 2]
Increase the extrusion amount of the extruder, increase the width of the unstretched sheet, and change the shielding plate attached to the hot air outlet of each plenum duct of the heat setting device so as to have the shielding rate shown in Table 2, A film having a thickness of 100 μm and a width of 5,300 mm was wound up by 6,500 m in the same manner as in Example 1 except that the temperature and wind speed of the first to fourth zones of the fixing device were changed to the adjustment values shown in Table 3. A mill roll was obtained. While rewinding the mill roll, both ends are removed by 150 mm, and the remaining part is slit into five at equal intervals in the width direction. By removing approximately 200 m from the surface of the mill roll, the width is 1,000 mm. 10 slit rolls having a winding length of 3,010 m were obtained. Of the 10 slit rolls obtained as described above, a film and a film roll using a slit roll corresponding to one edge side of the mill roll (the right side when viewed from the upstream side of the film flow) Evaluation of characteristics was performed. The evaluation results are shown in Table 4. In addition, the shielding mode by the shielding plate in Example 2 is referred to as “B mode”, and the temperature and wind speed conditions in the first to fourth zones in Example 2 are referred to as “II conditions”.

[Example 3]
The extrusion amount of the extruder is increased to increase the thickness of the unstretched sheet to 2,440 μm, and a cooling air of 16 ° C. is used in combination with the cooling with the casting drum, and the stretching ratio in the longitudinal direction is 3. Except for changing to 3 times, a mill roll was obtained in the same manner as in Example 1 except that a film having a thickness of 188 μm and a width of 3,300 mm was wound up by 4,500 m. While rewinding the mill roll, the process of removing both ends by 150 mm and slitting the remaining part into three at equal intervals in the width direction was performed, and by removing approximately 200 m from the surface layer of the mill roll, the width was 1,000 mm. Six slit rolls having a winding length of 2,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Example 4] The shielding plate attached to the hot air outlet of each plenum duct of the heat fixing device was changed to have the shielding rate shown in Table 2, and the temperatures and wind speeds of the first to fourth zones of the heat fixing device were changed to Table 3. 10 slit rolls were obtained in the same manner as in Example 2 except that the adjustment values were changed to the adjustment values shown in FIG. Note that the temperature and wind speed conditions in the first to fourth zones in Example 4 are referred to as “III conditions”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Example 5]
While adjusting the take-up speed of the unstretched sheet to change the thickness of the unstretched sheet to 1,030 μm, the ratio of the lateral relaxation treatment is changed to 2.3%, the temperature of the first to fourth zones of the heat setting device, Except that the wind speed was changed to each adjustment value shown in Table 3, a mill roll was obtained in the same manner as in Example 1 except that a film having a thickness of 75 μm and a width of 3,300 mm was wound up by 12,300 m. While rewinding the mill roll, remove both ends by 150 mm and repeat the process of slitting the remaining part into three at equal intervals in the width direction. By removing approximately 150 m from the surface layer of the mill roll, the roll is wound at a width of 1,000 mm. Six slit rolls having a length of 6,010 m were obtained. Note that the temperature and wind speed conditions in the first to fourth zones in Example 5 are referred to as “VIII conditions”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Example 6]
Mill roll obtained by winding 6,500 m of a film having a thickness of 125 μm and a width of 3,300 mm in the same manner as in Example 1 except that the take-up speed of the unstretched sheet was adjusted and the thickness of the unstretched sheet was changed to 1,720 μm. Got. While rewinding the mill roll, both ends were removed by 150 mm, and the remaining part was slit into three at equal intervals in the width direction. By removing about 300 m from the surface of the mill roll, the width was 1,000 mm. Six slit rolls having a winding length of 3,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Example 7]
While adjusting the take-up speed of the unstretched sheet to change the thickness of the unstretched sheet to 3,250 μm, a cooling air of 16 ° C. is used in combination with the cooling with the casting drum, and the stretching ratio in the longitudinal direction is 3. A film having a thickness of 250 μm and a width of 3,300 mm is 2,500 m in the same manner as in Example 1, except that the temperature and wind speed of the first to fourth zones of the heat setting device are changed to VIII conditions. A wound mill roll was obtained. While rewinding the mill roll, the process of removing both ends by 150 mm and slitting the remaining part into three at equal intervals in the width direction was performed, and by removing approximately 200 m from the surface layer of the mill roll, the width was 1,000 mm. Six slit rolls having a winding length of 1,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Example 8]
While adjusting the take-up speed of the unstretched sheet to change the thickness of the unstretched sheet to 1,030 μm, the ratio of the lateral relaxation treatment is changed to 2.3%, the temperature of the first to fourth zones of the heat setting device, Except that the wind speed was changed to each adjustment value shown in Table 3, a mill roll was obtained in the same manner as in Example 2 by winding a film having a thickness of 75 μm and a width of 5,200 mm for 12,300 m. After that, while rolling the mill roll, the process of slitting the remaining part into 5 parts at equal intervals in the width direction is repeated while removing both ends by 100 mm, and approximately 200 m is excluded from the surface layer (winding end part) of the mill roll. Thus, 10 slit rolls having a width of 1,000 mm and a winding length of 6,010 m were obtained. The temperature and wind speed conditions in the first to fourth zones in Example 4 are referred to as “IX conditions”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Example 9]
A mill roll in which a film having a thickness of 125 μm and a width of 5,200 mm was wound up by 6,500 m, except that the undrawn sheet take-up speed was adjusted and the thickness of the unstretched sheet was changed to 1,720 μm. Got. While rewinding the mill roll, remove both ends by 100 mm and repeat the process of slitting the remaining part into five at equal intervals in the width direction. By removing about 300 m from the surface of the mill roll, the width is 1,000 mm. Ten slit rolls having a winding length of 3,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Example 10]
While adjusting the take-up speed of the unstretched sheet to change the thickness of the unstretched sheet to 2,440 μm, a cooling air of 16 ° C. is used in combination with the casting drum for cooling, and the stretching ratio in the longitudinal direction is set to 3. Except having changed to 3 times, it carried out similarly to Example 8, and obtained the mill roll which wound up 4,500 m of the film of thickness 188 micrometers and width | variety 5,200 mm. While rewinding the mill roll, remove both ends by 100 mm and repeat the process of slitting the remaining part into five at equal intervals in the width direction. By removing about 200 m from the surface of the mill roll, the width is 1,000 mm. Ten slit rolls having a winding length of 2,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Example 11]
The thickness of the unstretched sheet was changed to 3,250 μm by adjusting the take-up speed of the unstretched sheet, and the same procedure as in Example 10 was performed except that a cooling air of 16 ° C. was used at the time of cooling with the casting drum. A mill roll was obtained by winding 2,500 m of a film having a thickness of 250 μm and a width of 5,200 mm. While rewinding the mill roll, remove both ends by 100 mm and repeat the process of slitting the remaining part into five at equal intervals in the width direction. By removing about 200 m from the surface of the mill roll, the width is 1,000 mm. Ten slit rolls having a winding length of 1,010 m were obtained. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Comparative Example 1]
Six slit rolls were obtained in the same manner as in Example 1 except that an integrated large shielding plate was attached to the hot air outlets of the plenum ducts a to o of the heat fixing device. The shape of the large shielding plate was adjusted so that each shielding rate was the same as in Example 1. Using the slit roll at the same position as in Example 1, the characteristics of the film and the film roll were evaluated. The evaluation results are shown in Table 4.

[Comparative Example 2]
A large shielding plate integrated with the hot air outlets of the plenum ducts a to v of the heat fixing device by changing the temperature and wind speed of the first to fourth zones of the heat fixing device to the adjustment values shown in Table 3. 10 slit rolls were obtained in the same manner as Example 2 except that was attached. The shape of the large shielding plate was adjusted so that each shielding rate was the same as in Example 2. The temperature and wind speed conditions in the first to fourth zones in Comparative Example 2 are defined as “IV conditions”. Using the slit roll in the same position as in Example 2, the characteristics of the film and the film roll were evaluated. The evaluation results are shown in Table 4.

[Comparative Example 3]
A large shielding plate integrated with the hot air outlets of the plenum ducts a to v of the heat fixing device by changing the temperature and wind speed of the first to fourth zones of the heat fixing device to the adjustment values shown in Table 3. 10 slit rolls were obtained in the same manner as Example 2 except that was attached. The shape of the large shielding plate was adjusted so that each shielding rate was the same as in Example 2. Using the slit roll in the same position as in Example 2, the characteristics of the film and the film roll were evaluated. The evaluation results are shown in Table 4.

[Comparative Example 4]
While changing the shielding mode by the rod-shaped shielding plate attached to the hot air outlet of each plenum duct of the heat fixing device a to o as shown in Table 2, the temperature and wind speed of the first to fourth zones of the heat fixing device are also shown. Except having changed to each adjustment value shown in 3, it carried out similarly to Example 1, and obtained six slit rolls. In addition, the length of the film width direction of each shielding plate in Comparative Example 4 is adjusted so as to become gradually narrower from the inlet to the outlet of the heat fixing device. Further, the shielding mode by the shielding plate in Comparative Example 4 is set as “C mode”, and the temperature and wind speed conditions in the first to fourth zones in Comparative Example 4 are set as “V condition”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Comparative Example 5]
Except that the heat fixing is performed without attaching a shielding plate to the hot air outlet of each plenum duct, and the temperature and wind speed of the first to fourth zones of the heat fixing device are changed to the adjustment values shown in Table 3, respectively. 6 slit rolls were obtained in the same manner as in Example 1. The temperature and wind speed conditions in the first to fourth zones in Comparative Example 5 are referred to as “VI conditions”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 1. The evaluation results are shown in Table 4.

[Comparative Example 6]
Except that the heat fixing is performed without attaching a shielding plate to the hot air outlet of each plenum duct, and the temperature and wind speed of the first to fourth zones of the heat fixing device are changed to the adjustment values shown in Table 3, respectively. Ten slit rolls were obtained in the same manner as described above. Note that the temperature and wind speed conditions of the first to fourth zones in Comparative Example 6 are defined as “VII conditions”. And the characteristic of a film and a film roll was evaluated using the slit roll in the same position as Example 2. The evaluation results are shown in Table 4.

[Comparative Example 7]
While adjusting the take-up speed of the unstretched sheet with the same raw material type as in Example 1, heat fixing is performed by a heat fixing device having five plenum ducts to which discontinuous shielding plates are attached, and each of the shielding plates is attached. Except for changing the air speed blown out of the plenum duct while keeping the plenum duct's hot air flow constant for each plenum duct, and changing the conditions of the heat fixing device as shown in Tables 1, 2, and 3, the same as in Example 1. 6 slit rolls were obtained. In addition, the wind speed shown in Table 3 has shown the wind speed of the first plenum duct and the wind speed of the last plenum duct. Further, the shielding mode by the shielding plate in Comparative Example 7 is set as “D mode”, and the temperature and wind speed conditions of the heat fixing device are set as “X conditions”. Using the slit roll at the same position as in Example 1, the characteristics of the film and the film roll were evaluated. The evaluation results are shown in Table 4.

[Effects of Example Film]
From Table 4, the film rolls of the examples all have a small difference in heat shrinkage rate (that is, a difference in heat shrinkage rate) over the entire width of the roll, and also a small amount of variation in the heat shrinkage rate in the longitudinal direction. Is easy to pass and suitable for post-processing. On the other hand, the film roll of the comparative example has a large difference in heat shrinkage rate over the entire width of the roll, and also has a large fluctuation amount of the heat shrinkage rate in the longitudinal direction, and the passability during post-processing is poor.

  Since the polyethylene terephthalate resin film roll of the present invention has excellent processing characteristics as described above, the heat treatment in the optical film used for various optical members and other post-processing is performed in a high temperature zone (160 ° C. It can be suitably used as a film for processing performed over a relatively long time (10 to 60 seconds).

Explanatory drawing which shows the shielding aspect by the conventional shielding board (a is a partial cross section of the heat fixing device, and b is the state where the shielding board is attached to the hot air outlet of the plenum duct from above. It shows what you saw). BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the shielding aspect by the shielding board in this invention (a is a partial vertical cross section of a heat fixing apparatus, b is the state which attached the shielding board to the hot-air blowing outlet of the plenum duct. Is a view from above.) It is explanatory drawing which shows the state which saw through the heat fixing apparatus used by the Example and the comparative example from the top. It is explanatory drawing which shows the shielding aspect by the shielding board in Example 1. FIG.

Explanation of symbols

1: Heat fixing device 2: Hot air outlet 3, a to x: Plenum duct F: Film S: Shielding plate A: Film winding direction Z1: First zone Z2: Second zone Z3: Third zone Z4: First 4 zones

Claims (5)

Winding a biaxially stretched polyethylene terephthalate resin film slit to have a length of 300 m to 8,000 m and a width of 0.7 m to 2.2 m,
Δn _ab is 0.015 or more and 0.060 or less, which is the difference between the refractive index in the direction that forms an angle of 45 degrees with the winding direction of the film and the refractive index in the direction that forms an angle of 135 degrees with the winding direction of the film. A biaxially stretched polyethylene terephthalate resin film roll,
The first sample cutout is provided within 2 m from the end of winding of the film, the final cutout is provided within 2 m from the start of winding of the film, and the length between the first and final cutout is divided into nine equal parts. A biaxially stretched polyethylene terephthalate-based resin film roll that satisfies the following requirements (1) to (3) when a total of 10 sample cutout portions are provided by providing sample cutout portions.
(1) When each sample is cut out from a position within 50 mm from one end edge and a position within 50 mm from the other end edge in the roll width direction, and the two samples are heated at 150 ° C. for 30 minutes. HS150, which is the heat shrinkage rate in the film winding direction, and when the heat shrinkage difference, which is the difference between the HS150, is obtained, the heat shrinkage difference in all cutout portions is 0.1% or less. (2) In each of the cutout portions, when a sample is cut out from a position within 50 mm from one end edge and a position within 50 mm from the other end edge in the width direction of the roll, and HS150 is obtained for each sample, HS150 of the samples at both end edges in all cutout parts is 0.7% or more and 2.0% or less 3) the amount of variation in the HS150 at one end edge in the width direction of the roll obtained at each cut-out portion, and the variation amount of HS150 other end edge in the width direction of the roll obtained in each cutout portion, both 0. It must be between 05% and 0.20% The biaxially stretched polyethylene terephthalate resin film roll according to claim 1, wherein the wound polyethylene terephthalate resin film has a thickness of 70 μm to 400 μm. A production method for producing a biaxially stretched polyethylene terephthalate resin film roll according to claim 1 or 2,
A film forming process for forming an unstretched sheet by melt-extruding a raw material resin from an extruder, a biaxial stretching process for biaxially stretching the unstretched sheet obtained in the film forming process in the longitudinal direction and the transverse direction, A heat setting step of heat fixing the film after axial stretching,
The method for producing a biaxially stretched polyethylene terephthalate resin film roll, characterized in that the heat setting step is performed in a heat setting device that satisfies the following requirements (4) to ( 7 ).
(4) A plurality of wide plenum ducts for blowing out hot air are arranged vertically opposite to the traveling direction of the film. (5) Shielding for shielding hot air outlets from the plurality of plenum ducts. (6) The dimension of each shielding plate in the traveling direction of the film is adjusted to be substantially the same as the dimension of the outlet of each plenum duct in the traveling direction of the film. The dimension in the width direction of the film is adjusted so as to become gradually longer with respect to the film traveling direction.
(7) Keep the plenum duct wind speed constant in each heat setting zone. In the biaxial stretching process, the film is stretched in the transverse direction after stretching the film in the longitudinal direction, and an intermediate zone that does not perform wind blowing is provided between the zone that performs the transverse stretching and the heat setting device. The manufacturing method of the biaxially-stretched polyethylene terephthalate-type resin film roll of Claim 3 characterized by these. The heat setting device is divided into a plurality of heat setting zones, and the product of the temperature difference and the wind speed difference between adjacent heat setting zones is set to be 250 ° C. · m / s or less. The manufacturing method of the biaxially-stretched polyethylene terephthalate-type resin film roll of Claim 3 or Claim 4 characterized by the above-mentioned.

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