JP6442376B2 - Polymer film - Google Patents

Description

  The present invention relates to a polymer film.

  Polymer films are widely used because they have flexibility and can be reduced in weight and thickness, and transparent polymer films are often used for optical applications. As an optical use, the protective film of a polarizing plate, retardation film, etc. which comprise a liquid crystal display device are mentioned, for example.

  The polymer film is usually produced in a long length by a continuous production method, wound in a roll shape, stored and transported. In the case of manufacturing in such a long manner, so-called knurling, which is a concavo-convex structure, is used to prevent displacement in the width direction of the film (hereinafter referred to as winding displacement) in a film roll formed by winding in a roll shape. Formed on the side.

  Various types and sizes of knurling recesses and protrusions have been proposed so far. For example, Patent Document 1 describes a knurling in which a plurality of dome-shaped convex objects are formed on one film surface. The convex object has a height of 5 μm to 500 μm. Patent Document 2 describes a knurling having a pair of convex portions on one film surface and a concave portion on the other film surface. The convex portion and the concave portion are formed so as to extend in the longitudinal direction of the film, respectively, and the concave portion is located between one and the other of the pair of convex portions. The convex portion has a height of 3 to 30 μm from one film surface, and the concave portion has a depth of 1 μm or more from the other film surface. Patent Document 3 describes a knurling that is wavy in a cross section along the width direction of the film.

International Publication No. 2010/143524 International Publication No. 2010/001751 JP 2013-136436 A

  However, the knurling of Patent Documents 1 to 3 has a certain effect on the winding deviation, but makes both ends of the film roll thicker than the central portion between both ends, and both ends become bulky. . Such an increase in bulk at both ends of the film roll causes, for example, a dent in the central portion of the film roll during or after winding to cause deformation of the film.

  Therefore, an object of the present invention is to provide a film that suppresses winding slip and bulkiness in a film roll.

In order to achieve the above-mentioned object, the present invention is provided with a knurling having a wavy cross-sectional shape in which convex portions and concave portions are alternately continuous along the width direction, and a product portion between both side portions. In the polymer film, the convex portion extends in the longitudinal direction of the polymer film, the radius of curvature at the top of the convex portion in the cross section along the width direction is R1, and the radius of curvature at the bottom of the concave portion is R2, and the polymer film When the thickness of the product part is T, R1> R2 + T is satisfied, and when the width of the convex part is 100, the width of the concave part is in the range of 80 to 120. Yes.

  The surfaces of the convex part and the concave part are preferably arc-shaped in cross section.

  The sum of the height of the convex portion and the depth of the concave portion is preferably equal to or less than the thickness of the polymer film.

  The curvature radius R1 is preferably in the range of 0.10 mm to 5.00 mm, and the pitch of the convex portions is preferably in the range of 0.2 mm to 2.0 mm.

  According to the present invention, winding slip and bulk increase in the film roll can be suppressed.

It is a perspective view of the film which implemented this invention. It is a schematic sectional drawing of the side part of a film. It is the schematic which shows a film manufacturing equipment. It is a perspective view of a knurling device. It is a side view of a knurling device.

  As shown in FIG. 1, a polymer film (hereinafter referred to as a film) 10 according to the present embodiment is long and is formed of a thermoplastic polymer (polymer compound). In this embodiment, cellulose triacetate (triacetyl cellulose, hereinafter referred to as TAC) is used as the thermoplastic polymer, but instead of TAC, cellulose acylate other than TAC, cyclic polyolefin, polyester, or the like may be used. May be.

Details of the cellulose acylate will be described below. Cellulose acylate has a ratio of esterifying the hydroxyl group of cellulose with carboxylic acid, that is, the acyl group substitution degree (hereinafter referred to as acyl group substitution degree) satisfies all the conditions of the following formulas (1) to (3). Particularly preferred are: In (1) to (3), A and B are both acyl group substitution degrees, the acyl group in A is an acetyl group, and the acyl group in B has 3 to 22 carbon atoms.
2.4 ≦ A + B ≦ 3.0 (1)
0 ≦ A ≦ 3.0 (2)
0 ≦ B ≦ 2.9 (3)

  Glucose units constituting cellulose and having β-1,4 bonds have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer in which some or all of the hydroxyl groups of cellulose are esterified, and the hydrogen of the hydroxyl group is substituted with an acyl group having 2 or more carbon atoms. Since the degree of substitution is 1 when esterification of one hydroxyl group in the glucose unit is 100%, in the case of cellulose acylate, the hydroxyl groups at the 2nd, 3rd and 6th positions are each 100% ester. The degree of substitution is 3.

  Here, the total acyl group substitution degree obtained by “DS2 + DS3 + DS6”, where the acyl group substitution degree at the 2-position in the glucose unit is DS2, the acyl substitution degree at the 3-position is DS3, and the acyl substitution degree at the 6-position is DS6 is 2. It is preferably from 00 to 3.00, more preferably from 2.22 to 2.90, and even more preferably from 2.40 to 2.88. Furthermore, “DS6 / (DS2 + DS3 + DS6)” is preferably 0.32 or more, more preferably 0.322 or more, and further preferably 0.324 to 0.340.

  There may be only one kind of acyl group, or two or more kinds. When there are two or more acyl groups, it is preferable that one of them is an acetyl group. The sum of the substitution degrees of the hydrogen at the 2-, 3- and 6-position hydroxyl groups with acetyl groups is DSA, and the sum of the substitution degrees with acyl groups other than the acetyl groups at the 2-, 3- and 6-positions is DSB. In this case, the value of “DSA + DSB” is preferably 2.2 to 2.86, and particularly preferably 2.40 to 2.80. DSB is preferably 1.50 or more, and particularly preferably 1.7 or more. In DSB, 28% or more is preferably 6-position hydroxyl group substitution, more preferably 30% or more, further preferably 31% or more, particularly preferably 32% or more substitution of 6-position hydroxyl group. It is preferable. In addition, the value of “DSA + DSB” at the 6-position of cellulose acylate is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more.

  The acyl group having 2 or more carbon atoms may be an aliphatic group or an aryl group, and is not particularly limited. For example, there are cellulose alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc., and these may each further have a substituted group. Propionyl group, butanoyl group, pentanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, iso-butanoyl group, t-butanoyl group, cyclohexane Examples thereof include a carbonyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, and a cinnamoyl group. Among these, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a t-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and a propionyl group and a butanoyl group are particularly preferable.

  In addition to the thermoplastic polymer, the film 10 may contain various additives such as a plasticizer, an ultraviolet absorber, and a retardation control agent, and a matting agent for preventing the films from sticking to each other.

  The film 10 includes a knurling 11 formed continuously in the longitudinal direction Z1 on each side portion. The knurling 11 may be formed only on one side, but it is preferable that the knurling 11 is formed on both sides as in the present embodiment because the winding deviation in the film roll can be more reliably suppressed. In addition, the film provided with knurling may be conveyed using a roller to a winding device for winding in a roll shape, and the conveyance roller 57 is also used in a film manufacturing facility 40 (see FIG. 3) described later. Conveying. In such a case, the so-called entrained air as the atmospheric flow generated along with the conveyance of the film causes the film to float on the roller, and the conveyance of the film may become unstable. It may cause meandering of the film being transported and may cause scratches on the film. Therefore, also from the viewpoint of more surely eliminating the air between the roller and the film, the knurling 11 is preferably formed on both sides than on the one side. Further, it is preferable that the film is formed on both sides because the film is more difficult to deform when stored in a film roll state. For example, when the film 10 is used as a constituent material of the display, the side portion including the knurling 11 is cut off, and the product portion between the two side portions is a sheet-like material constituting the display, for example, a protective film for a polarizing plate, Used for phase difference film. Moreover, an optically anisotropic layer, an antireflection layer, an antiglare function layer, etc. are provided to the product part, and it may be used as a highly functional film. In this embodiment, the width WA of the film 10, the width WS of the side portion, and the width WP of the product portion are 1490 mm for WA, 15 mm for WS, and 1460 mm for WP, but are not limited thereto.

  The knurling 11 has a wavy cross-sectional shape in which convex portions 15 and concave portions 16 are alternately continued along the width direction Z2. That is, a convex portion 15 that is curved on one film surface (hereinafter referred to as a first film surface) 10a and a concave portion 16 that is curved on the other film surface (hereinafter referred to as a second film surface) 10b are in the thickness direction. The plurality of convex portions 15 and the concave portions 16 formed between the adjacent convex portions 15 are formed so as to extend in the longitudinal direction of the film 10. In this example, the number of the convex portions 15 formed on the first film surface 10a is 3 and the number of the concave portions 16 is 3 on each side, and the convex portions 15 and the concave portions 16 formed on the second film surface 10b The number is the same. However, the number of the convex part 15 and the recessed part 16 is not limited to this, For example, it shall be in the range of 2 or more and 200 or less.

  In FIG. 2, when the width W15 of the convex portion 15 is set to 100, the width W16 of the concave portion is in the range of 80 to 120, thereby suppressing winding deviation and bulkiness in the film roll. The difference between the width W15 and the width W16 is preferably as small as possible. In this embodiment, the difference is 0 (zero), that is, the width W15 and the width W16 are equal to each other.

  The width W15 and the width W16 are each preferably in the range of 0.1 mm or more and 1.0 mm or less, so that winding deviation in the film roll can be more reliably suppressed. Further, when the film 10 passes over the transport roller 57 while the second film surface 10b is in contact with the later-described transport roller 57 (see FIG. 3), for example, the recesses in the transport roller 57 and the second film surface 10b. A large space is formed by 16 and air on the transport roller 57 is surely removed. Therefore, since the holding force of the film 10 by the conveyance roller 57 is increased, the conveyance is further stabilized, and as a result, the meandering and scratches of the film 10 are suppressed. In the following description, the exclusion of air on the transport roller 57 is simply referred to as air exclusion. In the present embodiment, the width W15 and the width W16 are each 0.25 mm.

Here, the radius of curvature at the apex 15a of the convex portion 15 is R1, the radius of curvature at the bottom 16a of the concave portion 16 is R2, and the thickness of the film 10 is T. As is well known, the radius of curvature is the radius of a circle when the curve curve is approximated to a circle. The curvature radius R1 is larger than the sum of the curvature radius R2 and the thickness T. That is, the film 10 satisfies R1> R2 + T. Therefore, the height H of the convex portion 15 is smaller than the depth D of the concave portion 16. By using the knurling 11 as described above, in the film roll, the convex portion 15 of the first film surface 10a of the film 10 previously wound is formed on the second film surface 10b of the film 10 wound thereon. The film 10 overlaps in such a manner that the convex portion 15 enters the concave portion 16 such as entering the concave portion 16. For this reason, since the retention strength between the films 10 increases in the film roll, winding deviation is suppressed. Moreover, since the convex part 15 enters into the concave part 16, the bulkiness of the film roll is suppressed. Further, in the wavy knurling 11, the radius of curvature R1 is larger than the radius of curvature R2, so that the film 10 is conveyed to the conveying roller 57 while the second film surface 10b is in contact with the conveying roller 57 (see FIG. 3) described later, for example. When passing over, a large space is formed by the conveyance roller 57 and the concave portion 16 in the second film surface 10b, and air is surely excluded.

  The curvature radius R1 is 0.40 mm in this example, but is not limited to this. From the viewpoint of more reliably suppressing winding deviation and bulkiness in the film roll and making air rejection more reliable, the curvature radius R1 is preferably in the range of 0.10 mm to 5.00 mm. Specifically, when the radius of curvature R1 is 0.10 mm or more, the air is more reliably excluded than when it is less than 0.10 mm, and when it is 5.00 mm or less, it is larger than 5.00 mm. Compared to the case, winding deviation is more reliably suppressed. The radius of curvature R1 is more preferably in the range of 0.20 mm or more and 1.00 mm or less.

  The curvature radius R2 is 0.30 mm in this example, but is not limited to this. From the viewpoint of more reliably suppressing winding deviation and bulking in the film roll and more reliably eliminating air, the curvature radius R1 is preferably in the range of 0.10 mm or more and 5.00 mm or less, and 0.20 mm. More preferably, it is in the range of 1.00 mm or less. The thickness T is 60 μm in this example, but is not limited to this.

  In this example, the surfaces of the convex portion 15 and the concave portion 16 are arcuate in the cross section in the width direction Z2, and therefore the curvature radius R1 and the curvature radius R2 are the radii of circles in this example. Thus, the knurling 11 formed by the convex portion 15 and the concave portion 16 having an arcuate surface can more reliably suppress the winding deviation and bulkiness of the film roll, and more reliably obtain the air exclusion effect. It is done. However, the shape of the surface of the convex portion 15 and the concave portion 16 in the cross section in the width direction Z2 is not limited to an arc shape, and may be an elliptical arc, a parabola, or a U shape, for example.

  When the height of the convex portion 15 is H and the depth of the concave portion 16 is D, the sum of the height H and the depth D is preferably equal to or less than the thickness T. As a result, even when the film 10 is wound around the transport roller 57 or is formed into a film roll, even if the film 10 is curved and deformed in the longitudinal direction, the convex portions 15 and the concave portions 16 are more difficult to break. The height H and the depth D are values based on the film surface on which the convex portions 15 and the concave portions 16 are formed. For example, the height H of the convex portion 15 formed on the first film surface 10a is the height to the apex 15a of the convex portion 15 with respect to the first film surface 10a in the product portion, and the first The depth D of the concave portion 16 formed on the film surface 10a is the depth to the bottom point 16a of the concave portion 16 when the first film surface 10a in the product portion is used as a reference. The height H of the convex portion 15 and the depth D of the concave portion 16 formed on the second film surface 10b are obtained in the same manner based on the second film surface 10b.

  The pitch P of the convex portions 15, that is, the distance between the apexes 15 a of the adjacent convex portions 15, is preferably within a range of 0.2 mm or more and 2.0 mm or less. It is suppressed, and the air evacuation becomes more reliable. Specifically, when the pitch P is 0.2 mm or more, winding deviation is more reliably suppressed than when the pitch P is less than 0.2 mm, and when the pitch P is 2.0 mm or less, the pitch P is larger than 2.0 mm. Compared with air, it is more reliable. In the present embodiment, the pitch P of the convex portions 15 is 0.50 mm. The pitch P is more preferably in the range of 0.5 mm to 1.0 mm.

  As shown in FIG. 3, the film manufacturing facility 40 is for manufacturing the film 10 and includes a film material manufacturing line 41, a knurling device 42, and a winding device 43. Although the film material production line 41 of this embodiment manufactures the elongate film material 46 with the solution casting method, it may replace with this and may manufacture with the melt extrusion method.

  The film material production line 41 is for producing a long film material 46 from a polymer solution (dope) in which a polymer is dissolved in a solvent. Although not shown, a casting device, a tenter, and a drying device are used. Etc. The polymer is the above-mentioned TAC, and a mixture of dichloromethane and methanol is used as the solvent. The casting apparatus forms the film material 46 in a state containing a solvent from the polymer solution. The tenter is stretched in the width direction while the side of the film material 46 is held by the holding member and conveyed in the longitudinal direction. The tenter includes a dry gas supply unit that supplies a dry gas to the film material 46 being conveyed, and the film material 46 being conveyed is dried by the dry gas from the dry gas supply unit. The drying apparatus dries by supplying a dry gas while conveying the film material 46 with a plurality of rollers.

  The knurling device 42 is for applying the knurling 11 to the film material 46. Thereby, the film 10 is obtained. In this example, the knurling device 42 is disposed between the film material production line 41 and the winding device 43. However, the knurling device 42 may be disposed in the film material production line 41. In this way, the film 10 is obtained. The details of the knurling device 42 will be described later with reference to another drawing.

  The winding device 43 is for winding the film 10 in a roll shape. The winding device 43 has a turret arm 48, and a winding shaft 50 is provided at each tip of the turret arm 48. A winding core 51 around which the film 10 is wound is set on the winding shaft 50. The turret arm 48 is intermittently rotated 180 degrees by an arm driving unit (not shown), and selectively switches the position of the winding core 51 between the winding position PS1 and the winding core replacement position PS2. A guide arm 54 is provided at an intermediate position in the rotational direction of the turret arm 48, and a guide roller 55 is attached to the distal end portion of the guide arm 54. The guide roller 55 supports the film 10 so that the film 10 does not come into contact with the turret arm 48 or the arm mounting shaft 56 when the turret arm 48 is rotating.

  The film 10 is conveyed to the winding position PS1 by a conveying roller 57 that is driven to rotate. At the winding position PS1, the film 10 is wound around the winding core 51. Further, at the winding core replacement position PS2, the film roll 60 that has been wound up with a certain length of the film 10 is removed from the winding shaft 50 together with the winding core 51. An empty core 51 is set, and the core 51 is exchanged.

  When the film 10 having a predetermined length is wound around the winding core 51 at the winding position PS1, and the film roll 60 is almost fully wound, the turret arm 48 is rotated 180 degrees to reach the winding core replacement position PS2. The film roll 60 close to full winding is positioned. An empty winding core 51 is positioned at the winding position PS1. When the film roll 60 reaches a predetermined length, a rewinding device (not shown) is activated to cut the film 10. The rear end portion of the cut preceding film 10 is wound around the film roll 60 at the core replacement position PS2. Further, the leading end portion of the cut film 10 is wound around the empty core 51 at the winding position PS1.

  Hereinafter, similarly, the film 10 that is continuously fed is formed in the form of the film roll 60 by winding the film 10 around the winding core 51.

  The film material 46 has a single layer structure in this example, but may have a multilayer structure. As the film material 46 having a multilayer structure, for example, there is one in which one or more thin films are formed on a plastic support. Further, the film material 46 is not limited to those for optical use, for example, a recording medium in which a vapor deposition layer, a coating layer, etc. are formed on a film formed from a polymer, an organic film, an inorganic film on a film formed from a polymer, and the like. Various things, such as a moisture-proof and air-proof film laminated | stacked, are mentioned.

  In the present embodiment, the knurling 11 is applied to both sides of the film material 46, so that the knurling device 42 includes two pairs of rollers each composed of a first knurling roller 61 and a second knurling roller 62 as shown in FIG. Prepare. When the knurling 11 is applied only to one side of the film material 46, only one roller pair is required. The roller pair is arranged in a passing region through which each side portion of the film material 46 passes in the conveyance path of the film material 46.

  The knurling device 42 includes a temperature control mechanism 66 (see FIG. 5), and a heater 67 and a temperature sensor 68 (see FIG. 5) constituting the temperature control mechanism 66 are also included in the film 10 in the transport path of the film 10. It is arranged in the passage area through which each side part passes. The heater 67 is also provided in the vicinity of the second knurling roller 62, but is not shown in FIG. 4 in order to avoid complication of the drawing. Details of the temperature control mechanism 66 will be described later with reference to another drawing.

  The first knurling roller 61 and the second knurling roller 62 are rotatably provided to face each other so that their rotation axes are parallel to each other, and cooperate to apply the knurling 11 to the film material 46.

  As shown in FIG. 5, protrusions 61 a and 62 a and grooves (not shown) are provided on the peripheral surfaces of the first knurling roller 61 and the second knurling roller 62 in order to impart the knurling 11 to the film material 46. A plurality of each is formed. The protrusion 61 a and the groove extend in the circumferential direction of the first knurling roller 61 and the second knurling roller 62, that is, in the longitudinal direction of the film material 46, and between the first knurling roller 61 and the second knurling roller 62. They are alternately formed along the respective rotation axis directions. The protrusion 62a and the groove are formed in the same manner.

  The first knurling roller 61 and the second knurling roller 62 are provided so that the protrusion 61a and the groove of the second knurling roller 62 face each other, and the groove of the first knurling roller 61 and the protrusion 62a face each other. The film material 46 is sandwiched between the knurling roller 61 and the second knurling roller 62 and is rotated by a motor (not shown). The direction of rotation of the first knurling roller 61 and the second knurling roller 62 is the conveying direction A of the film material 46, that is, the first knurling roller 61 is counterclockwise in FIG. 5 is the clockwise direction. The first knurling roller 61 and the second knurling roller 62 press the film material 46 being conveyed in the thickness direction to continuously form the knurling 11 on the film material 46. The pressing force for pressing the film material 46 by the first knurling roller 61 and the second knurling roller 62 is 0.3 MPa in this embodiment, but is not limited to this, and depends on the thickness and temperature of the film material 46. And adjust as appropriate.

  The temperature control mechanism 66 is for controlling the peripheral surface temperature of the first knurling roller 61 and the second knurling roller 62, and includes a heater 67, a temperature sensor 68, a control unit 69, and the like. The heater 67 is disposed near each of the first knurling roller 61 and the second knurling roller 62 and heats the first knurling roller 61 and the second knurling roller 62 under the control of the control unit 69. The heater 67 applies hot air to the first knurling roller 61 and the second knurling roller 62, applies heat to the first knurling roller 61 and the second knurling roller 62 by a ceramic heater, Various types can be used, such as those that inductively heat the first knurling roller 61 and the second knurling roller 62 by generating a magnetic field change in the vicinity of each of the first knurling roller 61 and the second knurling roller 62. In addition, when the first knurling roller 61 and the second knurling roller 62 are induction-heated, the first knurling roller 61 and the second knurling roller 62 are made of ferromagnetic metal such as iron, SUS440, super hard material, or the like. It is good to form from the metal which contains.

  The temperature sensor 68 is composed of, for example, a thermocouple or a radiation thermometer, and continuously or intermittently detects the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62 and sends a detection result to the control unit 69. Output. Based on the detection result from the input temperature sensor 68, the controller 69 controls the heater 67 so that the temperatures of the peripheral surfaces of the first knurling roller 61 and the second knurling roller 62 are within a preset temperature range. To control.

  Note that the control unit 69 is configured such that when the knurling 11 is applied, that is, the temperature of the film material 46 at the nipping position PN where the film material 46 is nipped by the first knurling roller 61 and the second knurling roller 62 (glass It is preferable to control the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62 so that it is in the range of (transition point−20 ° C.) or more (glass transition point + 20 ° C.). Specifically, the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62 is equal to or higher than (the melting point of the polymer constituting the film material −100 ° C.) or more (the melting point of the polymer constituting the film material 46). 20 ° C.) The following range is preferable. In the present embodiment, the glass transition point of the film material 46 is 150 ° C., the melting point of TAC as a polymer constituting the film material 46 is 290 ° C., and the temperature of the film material 46 at the sandwiching position PN is 140 ° C. .

  The conveyance speed of the film material 46, the thickness of the film material 46, the height H of the convex portion 15 and the depth D of the concave portion 16 in the knurling 11 to be applied, the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62 Depending on the above, it is preferable to adjust the contact time of the film material 46 with respect to each of the first knurling roller 61 and the second knurling roller 62, the nipping time between the first knurling roller 61 and the second knurling roller 62, and the like. As an adjustment method, for example, a winding angle (hereinafter referred to as a first wrap angle) θ1 of the film material 46 with respect to the first knurling roller 61 and a winding angle of the film material 46 with respect to the second knurling roller 62 (hereinafter, referred to as “first wrap angle”). This is a method of adjusting θ2 (referred to as a second wrap angle).

  In this embodiment, since the knurling 11 is provided on both sides, two each of the first knurling roller 61 and the second knurling roller 62 are used, but the present invention is not limited to this. For example, two first knurling rollers having protrusions 61a and grooves formed at both ends on the circumferential surface of one roller (not shown) extending in the width direction of the film material 46 over the entire width of the film material 46 It may replace with 61 and may be used. The same applies to the second knurling roller 62.

  In this example, the temperature sensor 68 detects the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62, but instead of this mode, the temperature of the film material 46 may be detected. . In that case, the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62 may be controlled based on the detection result of the temperature of the film material 46.

  In this example, the temperature of the film material 46 is adjusted by controlling the temperature of each peripheral surface of the first knurling roller 61 and the second knurling roller 62. However, the method for adjusting the temperature of the film material 46 is as follows. It is not limited to this. For example, the temperature of the film material 46 toward the first knurling roller 61 and the second knurling roller 62 may be adjusted by sending out a gas whose temperature is adjusted (for example, heated air) from the heater. Further, the temperature of the film material 46 is adjusted by adjusting the temperature of the chamber in which the knurling device 42 is accommodated, or by providing a chamber for adjusting the internal temperature upstream of the knurling device 42. May be. Furthermore, some film material production lines have, for example, a drying chamber having a temperature adjustment function for drying the film material being manufactured. The temperature may be adjusted.

[Example 1] to [Example 14]
Using the film manufacturing equipment 40, the film 10 having a thickness T of 60 μm and a width WA of 1490 mm and formed from TAC was manufactured as Examples 1 to 14. When the cross-sectional shape is wavy like the knurling 11, “W” is written in the “knurling shape” column of Table 1. For the knurling 11 of each example, the radii of curvature R1 and R2 (both units are mm), the height H (unit: μm) of the convex portion 15, the depth D (unit: μm) of the concave portion 16, and the pitch P (unit). : Mm), width W16: width W15 are shown in Table 1, respectively. The width W16: the width W15 is shown in the “Roughness width ratio” column of Table 1, and the transport speed (unit: m / min) and the tension in the transport direction A with respect to the film material 46 (hereinafter referred to as transport tension) are: These are shown in the “Transport Speed” column and the “Transport Tension” column of Table 1, respectively. The value of the conveyance tension is the tension per 1 m width of the film material 46, and the unit is N / m. The first wrap angle θ1 was 0 °.

  About each Example, the following method and reference | standard evaluated about winding deviation, bulkiness, an abrasion, meandering, and the crack of the knurling 11. The evaluation results are shown in Table 1.

(1) Winding deviation In the following evaluation criteria, A and B are acceptable levels, and C is an unacceptable level.
A: The deviation at the end face of the film roll 60 is less than 1 mm.
B: The deviation at the end face of the film roll 60 is 1 mm or more and less than 2 mm.
C: The shift | offset | difference in the end surface of the film roll 60 is 2 mm or more.

(2) Bulkiness The following P is acceptable and F is unacceptable.
P: The thickness in the film roll 60 is uniform.
F: The thickness of both ends in the film roll 60 is larger than the thickness of the central portion.

As an alternative evaluation of air removal, evaluation of scratches and meandering was performed. This is because the higher the air removal effect, the better the evaluation results of scratches and meandering.
(3) Scratch The product part of the film 10 was irradiated with light, and the presence or absence of scratches and the degree of scratches were evaluated visually. In the following evaluation criteria, A and B are pass levels, and C is a fail level.
A: No scratch is observed.
B: Scratches are observed, but the length is less than 50 μm.
C: Scratches having a length of 50 μm or more are observed.

(4) Meandering While the film 10 provided with the knurling 11 was conveyed to the winding device 43, the amount of deviation in the width direction Z2 was measured and evaluated according to the following criteria. In the following evaluation criteria, A and B are pass levels, and C is a fail level.
A: The amount of deviation is less than 0.5 mm on each of the one end side and the other end side in the width direction Z2.
B: The amount of deviation is 0.5 mm or more and less than 1 mm on one end side and the other end side in the width direction Z2.
C: The shift amount is 1 mm or more on each of the one end side and the other end side in the width direction Z2.

(5) Knurling crack The following P is acceptable and F is unacceptable.
P: No cracks are observed in the knurling 11 by visual observation.
F: Cracks are observed in the knurling 11 by visual observation.

[Comparative Example 1] to [Comparative Example 8]
Instead of the knurling 11 having a cross-sectional shape, a film provided with embossed knurling was manufactured, and Comparative Examples 1 to 3 were obtained. The embossed knurling is formed by forming a plurality of convex portions having a height of 20 μm on one film surface, and the shape of each convex portion is a quadrangular pyramid. About Comparative Examples 1-3 which are embossed knurling, it describes as "E" in the "Knurling shape" column of Table 1. The distance between adjacent convex parts is 1 mm. Instead of the first knurling roller 61, a first roller having a smooth circumferential surface was used, and instead of the second knurling roller 62, a second roller having irregularities corresponding to the embossed shape on the circumferential surface was used. The peripheral surface temperature of the first roller was room temperature (approximately 23 ° C.), and the peripheral surface temperature of the second roller was 200 ° C. The winding angle of the film with respect to the first roller was 10 °, and the winding angle with respect to the second roller was 10 °. The pressing force when pressing by the first roller and the second roller was 0.3 MPa. Moreover, as Comparative Examples 4-8, although the cross-sectional shape is wavy, the radius of curvature R1, R2, width W16: width W15 gave the knurling shown by Table 1, and manufactured the film. The cross-sectional shape of the surface of the convex part and the concave part of Comparative Examples 4 to 8 was an arc as in the example.

DESCRIPTION OF SYMBOLS 10 Film 11 Knurling 15 Convex part 16 Concave part 40 Film production equipment 42 Knurling apparatus

Claims (5)

In the long polymer film that is provided with a knurling with a wavy cross-sectional shape in which convex portions and concave portions are alternately continuous along the width direction on the side portion, and the product portion is between both side portions ,
The convex portion extends in the longitudinal direction of the polymer film;
R1> R2 + T, where R1 is the radius of curvature at the top of the convex portion in the cross section along the width direction, R2 is the radius of curvature at the bottom of the concave portion, and T is the thickness of the product portion of the polymer film. The filling,
The polymer film, wherein the width of the concave portion is in the range of 80 to 120 when the width of the convex portion is 100.   The polymer film according to claim 1, wherein surfaces of the convex portion and the concave portion are arc-shaped in cross section.   The polymer film according to claim 1 or 2, wherein the sum of the height of the convex portion and the depth of the concave portion is equal to or less than the thickness of the polymer film.   The polymer film according to any one of claims 1 to 3, wherein the radius of curvature R1 is in a range of 0.10 mm to 5.00 mm.   The polymer film according to any one of claims 1 to 4, wherein a pitch of the convex portions is in a range of 0.2 mm or more and 2.0 mm or less.

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