KR102482643B1 - Polymer film - Google Patents

Abstract

A polymer film that suppresses winding variation and bulking in a film roll is provided. The elongated film 10 has knurling 11 on each side. The knurling 11 has a wavy cross-sectional shape in which the convex portion 15 and the concave portion 16 are alternately continuous along the width direction Z2. The convex portion 15 and the concave portion 16 each extend in the longitudinal direction of the film 10 . When the width of the convex portion 15 is assumed to be 100, the width of the concave portion is in the range of 80 or more and 120 or less. In the cross section along the width direction Z2, the radius of curvature R1 at the vertex 15a of the convex portion 15, the radius of curvature R2 at the bottom point 16a of the concave portion 16, and the film 10 ), the thickness T satisfies R1>R2+T.

Description

Polymer film {POLYMER FILM}

The present invention relates to polymeric films.

Polymer films are used in many fields because they have flexibility and can be made into lightweight thin films, and among them, transparent polymer films are widely used for optical applications. As an optical use, the protective film of the polarizing plate which comprises a liquid crystal display device, retardation film, etc. are mentioned, for example.

A polymer film is usually manufactured into a long length by a continuous manufacturing method, wound into a roll shape, and stored and transported. In the case of manufacturing a long film in this way, so-called knurling, which is a concave-convex structure, is provided on the side in order to prevent variation in the width direction of the film (hereinafter referred to as winding variation) in a film roll formed by winding into a roll shape. is formed

As for the concave part and the convex part of the knurling, things of various shapes and sizes have been proposed so far. For example, International Publication No. 2010/143524 describes a knurling in which a plurality of dome-shaped convex objects were formed on one film surface. The convex shape has a height of 5 μm to 500 μm. International Publication No. 2010/001751 describes a pair of convex portions of a film on one film surface and a knurling having a concave portion on the other film surface. The convex portion and the concave portion are formed to extend in the longitudinal direction of the film, respectively, and the concave portion is located between one side of the pair of convex portions and the other. The convex portion has a height of 3 μm to 30 μm from one film surface, and the concave portion has a depth of 1 μm or more from the other film surface. In addition, in Japanese Unexamined Patent Publication No. 2013-136436, knurling that became wavy in the cross section along the width direction of the film is described.

However, knurling in International Publication No. 2010/143524, International Publication No. 2010/001751, and Japanese Patent Application Publication No. 2013-136436 has a certain effect on the winding deviation, but the both ends of the film roll are placed between the two ends. By making it thicker than the central part, both ends become bulky. Such bulking at both end portions of the film roll causes deformation of the film by causing, for example, a depression in the central portion of the film roll during or after winding.

An object of the present invention is to provide a polymer film that suppresses winding variation and bulking in a film roll.

The present invention is a long polymer film having a knurling in a wavy cross-sectional shape in which convex portions and concave portions are alternately continuous along the width direction, and a product portion is provided between both sides. The convex portion extends in the longitudinal direction of the polymer film. The radius of curvature at the apex of the convex portion in the cross section along the width direction of the polymer film is R1, the radius of curvature at the bottom of the concave portion is R2, and the thickness of the product portion of the polymer film is When T is expressed, the polymer film satisfies R1>R2+T, and when the width of the convex part is 100, the width of the concave part is within the range of 80 or more and 120 or less.

It is preferable that the surface of a convex part and a concave part has an arcuate 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 product portion of the polymer film.

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

It is preferable that the width|variety of a convex part exists in the range of 0.1 mm or more and 1.0 mm or less.

It is preferable that the surface of a convex part has an arc shape in the cross section along the width direction of a polymer film.

ADVANTAGE OF THE INVENTION According to this invention, winding variation and bulking in a film roll can be suppressed.

The above objects and advantages will be easily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.
1 is a perspective view of a film embodying the present invention.
2 is a schematic cross-sectional view of a side portion of a film.
Fig. 3 is a schematic diagram showing a film manufacturing facility.
Fig. 4 is a perspective view of a knurling device;
Fig. 5 is a side view of the knurling device;

As shown in Fig. 1, the polymer film (hereinafter referred to as "film") 10 of the present embodiment is elongated and is formed of a thermoplastic polymer (polymer compound). As the thermoplastic polymer, cellulose triacetate (triacetyl cellulose, hereinafter referred to as TAC) is used in the present embodiment, but instead of TAC, other cellulose acylates other than TAC, cyclic polyolefin, and polyester etc.

About cellulose acylate, the details are demonstrated below. In cellulose acylate, the ratio of esterification of hydroxyl groups of cellulose with carboxylic acid, that is, the degree of substitution of acyl groups (hereinafter referred to as the degree of substitution of acyl groups) satisfies all conditions of the following formulas (1) to (3): It is particularly desirable to In (1) to (3), both A and B represent degrees of substitution by acyl groups, 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)

The β-1, 4-bonded glucose units constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer in which a part or all of the hydroxyl groups of such cellulose are esterified and the hydrogens of the hydroxyl groups are substituted with acyl groups having 2 or more carbon atoms. In addition, since the degree of substitution is 1 when the esterification of one hydroxyl group in the glucose unit is 100%, in the case of cellulose acylate, when the hydroxyl groups at the 2nd, 3rd and 6th positions are each esterified 100%, the degree of substitution is It becomes 3.

Here, the degree of substitution of the acyl group at the 2nd position in the glucose unit is DS2, the degree of substitution of the acyl group at the 3rd position is DS3, and the degree of substitution of the acyl group at the 6th position is DS6, and the total acyl groups obtained by "DS2 + DS3 + DS6" The degree of substitution is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, still more preferably 2.40 to 2.88. Further, "DS6/(DS2+DS3+DS6)" is preferably 0.32 or more, more preferably 0.322 or more, and even more preferably 0.324 to 0.340.

One type of acyl group may be sufficient, and two or more types may be sufficient as it. When there are two or more types of acyl groups, it is preferable that one of them is an acetyl group. The total degree of substitution by the acetyl group of the hydrogen of the 2-position, 3-position, and 6-position hydrogen is called DSA, and the total degree of substitution by acyl groups other than the acetyl group at the 2-position, 3-position, and 6-position When referring to DSB, the value of "DSA+DSB" is preferably from 2.2 to 2.86, particularly preferably from 2.40 to 2.80. The DSB is preferably 1.50 or higher, and particularly preferably 1.7 or higher. And, in the DSB, it is preferable that 28% or more is 6-position hydroxyl substitution, more preferably 30% or more, still more preferably 31% or more, and particularly preferably 32% or more is 6-position hydroxyl substitution. it is desirable Further, the value of "DSA+DSB" at position 6 of the 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 either an aliphatic group or an aryl group, and is not particularly limited. For example, there are alkyl carbonyl esters, alkenyl carbonyl esters, aromatic carbonyl esters, aromatic alkyl carbonyl esters of cellulose, and the like, and these may each have a further 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 carbonyl group, oleoyl group, benzoyl group, naphthyl carbonyl group, cinnamoyl group, etc. are mentioned. Among these, propionyl group, butanoyl group, dodecanoyl group, octadecanoyl group, t-butanoyl group, oleoyl group, benzoyl group, naphthyl carbonyl group, cinnamoyl group and the like are more preferable, and propionyl group and butanoyl group is particularly preferred.

The film 10 may contain, in addition to the thermoplastic polymer, various additives such as plasticizers, ultraviolet absorbers, and retardation control agents, and a mat agent for preventing adhesion of films to each other.

The film 10 is equipped with each side part with the knurling 11 formed continuously in the longitudinal direction Z1. Although the knurling 11 may be formed only in one side part, since the winding deviation in a film roll can be suppressed more reliably, the direction formed in both sides like this embodiment is preferable. In addition, the film to which knurling is provided may be conveyed using a roller in a winding device for winding into a roll shape, and also in a film manufacturing facility 40 (see Fig. 3) described later, a conveyance roller 57 is used. are sending back In such a case, the so-called entrained air as an atmospheric stream generated along with the conveyance of the film may lift the film on the roller, making the conveyance of the film unstable, and this instability may cause meandering of the film during conveyance. In some cases, it is called, or scratches are generated on the film. Then, also from a viewpoint of more reliably excluding the air between a roller and a film, the knurling 11 is more preferable than the case where it is formed only in one side part when it is formed in both sides. Moreover, the one formed on both sides is preferable because the film 10 is more difficult to deform even when stored in the state of a film roll. When the film 10 is used as a constituent material of a display, for example, the side portion including the knurling 11 is cut off, and the product portion between the both sides is a sheet-like object constituting the display, for example, a polarizing plate. It is used for a protective film or a retardation film. Moreover, an optically anisotropic layer, an antireflection layer, an antiglare functional layer, etc. are applied to a product part, and it is used as a highly functional film in some cases. Although the width (WA) of the film 10, the width (WS) of the side part, and the width (WP) of the product part are 1490 mm for WA, 15 mm for WS, and 1460 mm for WP in this embodiment, they are not limited thereto.

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

2, when the width W15 of the convex portion 15 is 100, the width W16 of the concave portion is within the range of 80 or more and 120 or less, thereby suppressing the winding variation and bulking in the film roll. there is. The smaller the difference between the width W15 and the width W16, the better. In this embodiment, the difference is 0 (zero), that is, the width W15 and the width W16 are equal to each other. In addition, the boundary between the convex portion 15 and the concave portion 16 adjacent to each other corresponds to the inflection point of the outline representing the first film surface 10a or the second film surface 10b in FIG. 2, and the width ( W15) and width W16 are distances between points of inflection, respectively.

It is preferable that the width W15 and the width W16 fall within a range of 0.1 mm or more and 1.0 mm or less, respectively, whereby the winding deviation in the film roll is more reliably suppressed. In addition, as a result of this, when the film 10 passes over 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, the conveying roller ( 57) and the concave portion 16 in the second film surface 10b, a large space is ensured, so that air on the conveying roller 57 is reliably removed. Therefore, since the holding force of the film 10 by the conveyance roller 57 is improved, conveyance is more stable, and as a result, meandering and scratches of the film 10 are suppressed. In addition, in the following description, air elimination on the conveyance roller 57 is simply referred to as air elimination. In this embodiment, the width W15 and the width W16 are each set to 0.25 mm.

Here, the radius of curvature at the vertex 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 product portion of the film 10 is T. do. As is well known, the radius of curvature is the radius of a circle when the curved state is approximated to a circle. The radius of curvature R1 is greater than the sum of the radius of curvature R2 and the thickness T of the product portion. 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 setting it as the above knurling 11, in a film roll, the convex part 15 of the 1st film surface 10a of the film 10 wound previously is the 2nd film surface of the film 10 wound thereon ( The films 10 are overlapped in such a way that the convex portion 15 enters the concave portion 16, such as entering the concave portion 16 of 10b). For this reason, since the holding force of the film 10 comrades in a film roll becomes high, winding deviation is suppressed. In addition, since the convex portion 15 enters the concave portion 16, bulking of the film roll is suppressed. Moreover, in the wavy knurling 11, since the radius of curvature R1 is larger than the radius of curvature R2, for example, the second film surface 10b is in contact with the transport roller 57 (see Fig. 3) described later. When the film 10 passes over the conveying roller 57, the space formed by the concave portion 16 between the conveying roller 57 and the second film surface 10b is largely secured, and air is removed. becomes certain

Although the radius of curvature R1 is 0.40 mm in this example, it is not limited thereto. It is preferable that the curvature radius R1 is in the range of 0.10 mm or more and 5.00 mm or less from the viewpoint of more reliably suppressing winding variation and bulking in the film roll and ensuring air removal more reliably. Specifically, when the radius of curvature R1 is 0.10 mm or more, air removal is more reliable than when it is less than 0.10 mm, and when it is 5.00 mm or less, winding deviation is suppressed more reliably than when it is greater than 5.00 mm. The radius of curvature R1 is still more preferably within a range of 0.20 mm or more and 1.00 mm or less.

Although the radius of curvature R2 is 0.30 mm in this example, it is not limited thereto. From the viewpoint of more reliably suppressing winding variation and bulking in the film roll and more reliably removing air, the radius of curvature R1 is preferably in the range of 0.10 mm or more and 5.00 mm or less, and is 0.20 mm or more and 1.00 mm or less. It is even more preferable to be within the range of The thickness T of the product part is set to 60 μm in this example, but is not limited thereto.

In this example, the surfaces of the convex portion 15 and the concave portion 16 are arcuate in cross section in the width direction Z2, and therefore, the radius of curvature R1 and the radius of curvature R2 are circular in this example. is the radius Thus, by the knurling 11 formed by the convex portion 15 and the concave portion 16 having arc-shaped surfaces, the winding deviation and bulking in the film roll are more reliably suppressed, and the air removal effect is also improved. can be obtained more reliably. However, the shape of the surface of the convex part 15 and the concave part 16 in the cross section in the width direction Z2 is not limited to the circular arc shape, For example, an elliptical arc or a parabola may be sufficient, or It may be U-shaped.

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 of the product portion. Accordingly, even if the film 10 is bent and deformed in the longitudinal direction when the film 10 is wound around the conveyance roller 57 or formed into a film roll, the convex portion 15 and the concave portion 16 are less likely to crack. Both the height H and the depth D are values based on the film plane on which the convex portions 15 and the concave portions 16 are formed. For example, the height H of the convex part 15 formed on the first film surface 10a is the apex of the convex part 15 when the first film surface 10a in the product part is taken as a standard. (15a), and the depth D of the concave portion 16 formed in the first film surface 10a is the concave portion when the first film surface 10a in the product portion is used as a standard 16) is the depth to the bottom point 16a. The height H of the convex part 15 and the depth D of the concave part 16 formed in the 2nd film surface 10b are obtained similarly with the 2nd film surface 10b as a reference.

The pitch P of the convex portions 15, that is, the distance between vertices 15a of adjacent convex portions 15, is preferably in the range of 0.2 mm or more and 2.0 mm or less, so that the winding deviation in the film roll is more It is suppressed reliably, and air elimination becomes more reliable. Specifically, when the pitch P is 0.2 mm or more, the winding deviation is more reliably suppressed compared to the case where it is less than 0.2 mm, and when it is 2.0 mm or less, air exclusion becomes more certain than when it is larger than 2.0 mm. In this embodiment, the pitch P of the convex part 15 is 0.50 mm. As for the pitch P, it is more preferable that it exists in the range of 0.5 mm or more and 1.0 mm or less.

As shown in FIG. 3, the film production facility 40 is for producing the film 10, and includes a film material production line 41, a knurling device 42, and a winding device 43. . In the film material production line 41 of the present embodiment, the long film material 46 is manufactured by a solution film forming method, but may be manufactured by a melt extrusion method instead.

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, and although not shown, a casting device, a tenter, a drying device, etc. provide The polymer is the aforementioned TAC, and a mixture of dichloromethane and methanol is used as the solvent. The casting device forms the film material 46 from a polymer solution in a state containing a solvent. The tenter extends the film material 46 in the width direction while holding the side portion of the film material 46 with a holding member and conveying it in the longitudinal direction. The tenter has a drying gas supply unit that supplies dry gas to the film material 46 being conveyed, and the film material 46 being conveyed is dried by the dry gas from the drying gas supply unit. . The drying device dries the film material 46 by supplying a drying gas while conveying it with a plurality of rollers.

The knurling device 42 is for providing a knurling 11 to the film material 46 . Thus, the film 10 is obtained. Although the knurling device 42 is disposed between the film material production line 41 and the winding device 43 in this example, it may be disposed in the film material production line 41, in that case the film material production line 41 ), the film 10 is obtained. In addition, the details of the knurling device 42 are described later using other drawings.

The winding device 43 is for winding the film 10 into 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 rotated 180 degrees intermittently by an arm driving unit (not shown) to selectively switch the position of the core 51 to a winding position PS1 and a winding position PS2. In addition, a guide arm 54 is installed at an intermediate position in the rotational direction of the turret arm 48, and a guide roller 55 is attached to the front end 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 the conveyance roller 57 driven to rotate. At the winding-up position PS1, the film 10 is wound around the core 51. Further, at the core exchange position PS2, the film roll 60, which has been rolled up by winding the film 10 of a certain length, is removed from the take-up shaft 50 together with the core 51, and this winding A new empty core 51 is set on the shaft 50, and the core 51 is replaced.

At the winding position PS1, when the film 10 of a predetermined length is wound around the core 51 and the film roll 60 is in a state close to full, the turret arm 48 rotates 180 degrees to exchange the core 51. A film roll 60 close to ten thousand is placed at the position PS2. Moreover, the empty winding core 51 is positioned at the winding position PS1. When the film roll 60 reaches a predetermined length, a winding device not shown in the drawing operates, and the film 10 is cut. The rear end of the cut preceding film 10 is wound around the film roll 60 at the core exchange position PS2. Further, the front end of the cut subsequent film 10 is wound around the empty core 51 at the winding position PS1.

Hereinafter, similarly, by winding the film 10 around the core 51, the film 10 sent continuously becomes the form of the film roll 60.

The film material 46 has a single-layer structure in this example, but may have a multi-layer structure. As the film material 46 having a multi-layer structure, there is, for example, one in which a single layer or a plurality of thin films are formed on a plastic support. In addition, the film material 46 is not limited to those for optical use, and examples include a recording medium in which a deposition layer, an application layer, etc. are formed on a film formed of a polymer, and a moisture-proofing device in which an organic film or an inorganic film is laminated on a film formed of a polymer. Various things, such as a film, are mentioned.

In this embodiment, since the knurling 11 is provided to both sides of the film material 46, the knurling device 42 has the 1st knurling roller 61 and the 2nd knurling roller 62, as shown in FIG. ) is provided with two pairs of rollers. When providing the knurling 11 only to one side part of the film material 46, a pair of rollers becomes only one pair. The pair of rollers is arranged in a passage area through which each side of the film member 46 passes among the transport paths of the film member 46 .

The knurling device 42 is provided with a temperature control mechanism 66 (see Fig. 5), and the heater 67 and the temperature sensor 68 (see Fig. 5) constituting the temperature control mechanism 66 are also Among the conveying paths of the film 10, each side of the film 10 is disposed in a passage area through which it passes. Moreover, although the heater 67 is provided also in the vicinity of the 2nd knurling roller 62, in FIG. 4, what is shown in drawing is abbreviate|omitted in order to avoid complexity of drawing. Details of the temperature control mechanism 66 will be described later using other drawings.

The 1st knurling roller 61 and the 2nd knurling roller 62 are provided rotatably facing each other so that rotation axes may become a mutually parallel attitude, and apply the knurling 11 to the film material 46 cooperatively.

As shown in Fig. 5, projections 61a and 62a are formed on the circumferential surfaces of the first knurled roller 61 and the second knurled roller 62 in order to provide the film material 46 with knurling 11. A plurality of and grooves (not shown) are respectively formed. The protrusion 61a and the groove extend in the circumferential direction of each of the first knurled roller 61 and the second knurled roller 62, that is, in the longitudinal direction of the film material 46, and the first knurled roller 61 and the second knurling roller 62 are alternately formed along the direction of each rotation axis. The protrusion 62a and the groove are similarly formed.

The first knurled roller 61 and the second knurled roller 62 are such that the grooves of the projection 61a and the second knurled roller 62 are opposite, and the groove of the first knurled roller 61 and the projection 62a are opposite. ) is installed, and is rotated by a motor (not shown) in a state where the film material 46 is sandwiched between the first knurled roller 61 and the second knurled roller 62. The rotation direction of the 1st knurled roller 61 and the 2nd knurled roller 62 is the conveyance direction A of the film material 46, ie, the clockwise direction in FIG. 5 for the 1st knurled roller 61, the 1st About the two knurling rollers 62, it is a counterclockwise direction in FIG. These 1st knurling roller 61 and 2nd knurling roller 62 press the film material 46 in conveyance in the thickness direction, and form the knurling 11 in the film material 46 continuously. In addition, although the pressing force which presses the film material 46 by the 1st knurling roller 61 and the 2nd knurling roller 62 is 0.3 MPa in this embodiment, it is not limited to this, The film material 46 It may be appropriately adjusted according to the thickness and temperature of the

The temperature control mechanism 66 is for controlling the temperature of the circumferential surface of the first knurled roller 61 and the second knurled roller 62, and includes a heater 67, a temperature sensor 68, a control unit 69, and the like. It consists of The heater 67 is disposed near each of the first knurled roller 61 and the second knurled roller 62, and the first knurled roller 61 and the second knurled roller 62 are heated under the control of the controller 69. heat up As the heater 67, hot air is applied to the first knurled roller 61 and the second knurled roller 62, and infrared rays are generated by a ceramic heater or the like to the first knurled roller 61 and the second knurled roller 62. Induction heating of the first knurled roller 61 and the second knurled roller 62 by applying a magnetic field change in the vicinity of the first knurled roller 61 and the second knurled roller 62, respectively. type can be used. In addition, when induction heating the 1st knurled roller 61 and the 2nd knurled roller 62, the 1st knurled roller 61 and the 2nd knurled roller 62 are ferromagnetic, such as iron, SUS440, super hard material, etc. What is necessary is just to form with metal or the metal containing this.

The temperature sensor 68 is composed of, for example, a thermocouple or a radiation thermometer, and continuously or intermittently detects the temperature of each circumferential surface of the first knurled roller 61 and the second knurled roller 62, and the control unit 69 ) to output the detection result. Based on the detection result from the input temperature sensor 68, the controller 69 controls the temperature of each circumferential surface of the first knurled roller 61 and the second knurled roller 62 to fall within a preset temperature range. The heater 67 is controlled.

Moreover, the control part 69 is set to the clamping position PN where the film material 46 is clamped by the 1st knurled roller 61 and the 2nd knurled roller 62, that is, when the knurling 11 is provided. of the first knurled roller 61 and the second knurled roller 62 so that the temperature of the film material 46 in the chamber is within the range of (glass transition point -20°C) or more and (glass transition point +20°C) or less. It is desirable to control the temperature of each circumferential surface. Specifically, the temperature of each circumferential surface of the first knurled roller 61 and the second knurled roller 62 is (melting point of the polymer constituting the film material 46 -100 ° C.) or higher (film material 46) The melting point of the polymer constituting the -20 ° C.) or less is preferably within the range. In this 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 film material 46 at the pinched position PN is set to 140°C.

Conveyance speed of film material 46, thickness of film material 46, height H of convex part 15 in knurling 11 to be applied, depth D of concave part 16, first knurled roller 61 ) and the temperature of each circumferential surface of the second knurled roller 62, the contact time of the film material 46 to each of the first knurled roller 61 and the second knurled roller 62, or the first It is preferable to adjust the nipping time by the knurled roller 61 and the second knurled roller 62 or the like. As a method of this adjustment, for example, the winding angle of the film material 46 with respect to the first knurled roller 61 (hereinafter referred to as the first wrap angle) θ1 and the second knurled roller 62 This is a method of adjusting the winding angle (hereinafter, referred to as the second wrap angle) (θ2) of the film material 46 with respect to .

In this embodiment, the first knurled roller 61 and the second knurled roller 62 are respectively used by providing knurling 11 on both sides, but are not limited thereto. For example, 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, projections 61a and grooves are formed at both ends. You may use what is formed instead of the two 1st knurling rollers 61. The same applies to the second knurled roller 62.

In this example, the temperature sensor 68 detects the temperature of each circumferential surface of the first knurled roller 61 and the second knurled roller 62, but detects the temperature of the film material 46 instead of this aspect. You can do it. In that case, based on the detection result of the temperature of the film material 46, it is good to control the temperature of each circumferential surface of the 1st knurled roller 61 and the 2nd knurled roller 62.

In addition, in this example, the temperature of the film material 46 is adjusted by controlling the temperature of each circumferential surface of the first knurled roller 61 and the second knurled roller 62, but the temperature of the film material 46 The adjusting method is not limited thereto. For example, you may adjust the temperature of the film material 46 which faces the 1st knurled roller 61 and the 2nd knurled roller 62 by sending out the temperature-adjusted gas (for example, heated air) from a heater. Further, by adjusting the temperature of the chamber in which the knurling device 42 was put, or providing a chamber upstream of the knurling device 42 to adjust the internal temperature, and passing through this chamber, the film material 46 You can also adjust the temperature. In addition, since some film material production lines have, for example, a drying chamber having a temperature control function to dry the film material under manufacture, the temperature of the film material 46 may be adjusted by passing it through the inside of this drying chamber.

[Example]

[Example 1] to [Example 14]

Using the film manufacturing facility 40, the thickness T of the product part is 60 micrometers, and the width WA is 1490 mm, and the film 10 formed by TAC was manufactured, and it was set as Examples 1-14. When the shape of the cross section is wavy like the knurling 11, it describes as "W" in the "shape of knurling" column of Table 1. For the knurling 11 of each embodiment, the curvature radii R1 and R2 (both units are mm), the height H of the convex portion 15 (unit: μm), and the depth D of the concave portion 16 (unit: μm) , pitch P (unit: mm), width W16 : width W15 are shown in Table 1, respectively. In addition, the width W16:width W15 is shown in the column of "uneven width ratio" in Table 1, and the ratio of the conveying speed (unit: m/min) and the conveying direction A with respect to the film material 46 The tension (hereinafter referred to as conveyance tension) is shown in the "Conveyance speed" column and the "Conveyance tension" column of Table 1, respectively. The value of the transport tension is the tension per 1m of width of the film member 46, and the unit is N/m. The first wrap angle θ1 was 0°.

For each Example, winding deviation, bulking, scratches, meandering, and cracking of the knurling 11 were evaluated according to the following methods and standards. Table 1 shows the evaluation results.

(1) winding deviation

In the following evaluation criteria, A and B are pass levels, and C are disqualified levels.

A: Variation at the end face of the film roll 60 is less than 1 mm.

B: Variation at the end surface of the film roll 60 is 1 mm or more and less than 2 mm.

C: Variation at the end surface of the film roll 60 is 2 mm or more.

(2) bulking

The following P is a pass, F is a fail.

P: The thickness in the film roll 60 is uniform.

F: In the film roll 60, the thickness of both ends is larger than the thickness of the central part.

As an alternative evaluation of air exclusion, scratches and meandering were evaluated. This is because the higher the air removal effect, the better the evaluation results of scratches and meandering.

(3) Scratch

The product portion of the film 10 was irradiated with light, and the presence or absence of scratches and the degree of scratches were visually evaluated. In the following evaluation criteria, A and B are pass levels, and C are disqualified levels.

A: No scratches are visible.

B: A scratch is seen, but the length is less than 50 μm.

C: Scratches with a length of 50 μm or more are observed.

(4) Meandering

While the film 10 to which the knurling 11 was provided was conveyed by the winding device 43, the amount of variation 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 are disqualified levels.

A: The amount of deviation is less than 0.5 mm on one end side and the other end side of the width direction Z2, respectively.

B: The amount of deviation is 0.5 mm or more and less than 1 mm, respectively, on one end side and the other end side in the width direction Z2.

C: The amount of deviation is 1 mm or more on one end side and the other end side in the width direction Z2, respectively.

(5) Knurled cracks

The following P is a pass, F is a fail.

P: Visually, no crack was observed in the knurling 11.

F: Visually, a crack is seen in the knurling 11.

[Table 1]

[Comparative Example 1] to [Comparative Example 8]

Instead of the knurling 11 whose cross-sectional shape is wavy, the film to which embossed knurling was provided was manufactured, and it was set as Comparative Examples 1-3. The embossed knurling formed a plurality of convex portions with a height of 20 μm on one film surface, and the shape of each convex portion was a quadrangular truncated shape. About Comparative Examples 1-3 which are embossed knurling, it describes as "E" in the "shape of knurling" column of Table 1. The distance between adjacent convex parts is 1 mm. Instead of the first knurled roller 61, a first roller having a smooth circumferential surface was used, and instead of the second knurled roller 62, a second roller having irregularities according to the embossed shape 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 1st roller was 10 degrees, and the winding angle with respect to the 2nd roller was set to 10 degrees. The pressing force at the time of pressurization by the 1st roller and the 2nd roller was 0.3 Mpa. In addition, as Comparative Examples 4 to 8, although the cross-sectional shape is wave-like, the radii of curvature R1, R2, width (W16): width (W15) were provided with knurling shown in Table 1 to prepare films. The cross-sectional shape of the surface of the convex part and the concave part of Comparative Examples 4 to 8 was made into a circular arc as in the examples.

Claims (10)

In a long polymer film having a knurling in a wavy cross-section shape in which convex portions and concave portions are alternately continuous along the width direction, and having a product portion between both sides, ,
The convex portion extends in the longitudinal direction of the polymer film,
The radius of curvature at the vertex of the convex portion in the cross section along the width direction is R1, the radius of curvature at the bottom of the concave portion is R2, and the thickness of the product portion of the polymer film is T When R1>R2+T is satisfied,
A polymer film in which the width of the concave portion is in the range of 80 or more and 120 or less when the width of the convex portion is 100. According to claim 1,
The surface of the convex portion and the concave portion is a polymer film having an arc shape in cross section. According to claim 1 or 2,
The sum of the height of the convex portion and the depth of the concave portion is less than or equal to the thickness of the product portion of the polymer film. According to claim 1 or 2,
The curvature radius R1 is a polymer film within the range of 0.10 mm or more and 5.00 mm or less. According to claim 3,
The curvature radius R1 is a polymer film within the range of 0.10 mm or more and 5.00 mm or less. According to claim 1 or 2,
The pitch of the convex portion is a polymer film within the range of 0.2 mm or more and 2.0 mm or less. According to claim 3,
The pitch of the convex portion is a polymer film within the range of 0.2 mm or more and 2.0 mm or less. According to claim 4,
The pitch of the convex portion is a polymer film within the range of 0.2 mm or more and 2.0 mm or less. According to claim 1 or 2,
The polymer film in which the width of the convex portion is in the range of 0.1 mm or more and 1.0 mm or less. According to claim 1 or 2,
The surface of the convex portion is a polymer film having an arc shape in a cross section along the width direction.

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