CN115803175B - Long strip membrane - Google Patents

Abstract

The present invention relates to a long film having a plurality of knurled portions, wherein the planar shape of the knurled portions as viewed from the thickness direction of the long film includes a first line group portion and a second line group portion, the first line group portion and the second line group portion include a plurality of straight line portions and corner portions, the corner portions each independently have an angle of 80 ° to 100 °, and the positions of the corner portions are different in the width direction of the long film.

Description

Strip film

Technical Field

The present invention relates to a long film having knurled portions.

Background

Conventionally, films such as optical films have been produced as long films that have grown from the standpoint of achieving high productivity. However, since the film is generally thin, the handleability is sometimes poor. Therefore, it has been proposed to form uneven portions at the ends of the film in the width direction, thereby improving the handling properties of the film (patent document 1).

Prior art literature

Patent literature

Patent document 1, international publication No. 2017/145718.

Disclosure of Invention

Problems to be solved by the invention

In normal production, the long film is continuously transported in the longitudinal direction thereof, subjected to various treatments, and then wound into a roll form and shipped. In general, when a long film is wound to form a roll, an air layer is formed between the wound and overlapped long films. In this way, the long films wound and overlapped can be kept from contacting each other in the region where the air layer exists.

In the case where the air layer is thin, the long films may contact each other and adhere to each other on the surface. The phenomenon of surface adhesion of the long films stacked on the roll in this way is sometimes referred to as "blocking". For example, the roll may be stored in a state where the axial direction thereof is horizontal. In this case, in the roll, stress to be compressed in the axial direction is generated by the self weight of the roll. When the stress causes deformation of the shape of the roll, locally creating a thin air layer portion, blocking may occur at the portion.

In the case where the above-mentioned stress to be compressed in the axial direction is generated in the roll, buckling may be generated in the circumferential surface of the roll when the stress becomes large. The "buckling" of the roll means a recess formed by partially recessing the roll in the radial direction. This buckling is likely to occur in the portion where the air layer thickness between the long films wound and overlapped is thick. In the portion where the buckling occurs, the long film is deformed to form wrinkles.

The property of being able to suppress the above-described blocking and wrinkling is sometimes referred to as "windability" of the long film. When the uneven portion as in patent document 1 is formed on the film, the film winding property can be improved to some extent, but further improvement of the winding property is demanded.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a long film excellent in winding property.

Solution for solving the problem

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the above problems can be solved by the following long film, and have completed the present invention. Namely, the present invention includes the following.

[1] A long film having a plurality of knurled sections formed of continuous linear concave-convex sections on at least one surface, wherein,

The plane shape of the knurled part is seen from the thickness direction of the strip film and comprises a first thread group part and a second thread group part,

The first string part includes:

A first straight line part extending from the first position to the first corner part in a straight line,

A second straight line portion extending linearly from the first corner portion to the second corner portion,

A third linear portion extending linearly from the second corner portion to the third corner portion,

A fourth linear portion extending linearly from the third corner portion to the fourth corner portion,

A fifth linear portion extending linearly from the fourth corner portion to the fifth corner portion,

A sixth linear portion extending linearly from the fifth corner portion to the sixth corner portion,

A seventh linear portion extending linearly from the sixth corner portion to the seventh corner portion, and

An eighth linear portion extending linearly from the seventh corner portion to the second position,

The second wire group portion includes:

a ninth linear portion extending linearly from the third position to the eighth position,

A tenth linear portion extending linearly from the eighth corner portion to the ninth corner portion,

An eleventh linear portion extending linearly from the ninth corner portion to the tenth corner portion,

A twelfth linear portion extending linearly from the tenth corner portion to the first corner portion,

A thirteenth linear portion extending linearly from the tenth corner portion to the twelfth corner portion,

A fourteenth linear portion extending linearly from the twelfth corner portion to the tenth corner portion,

A fifteenth linear portion extending linearly from the tenth triangular portion to the tenth corner portion, and

A sixteenth linear portion extending linearly from the tenth corner portion to a fourth position,

The first to fourteenth corners each independently have an angle of 80 DEG to 100 DEG,

The positions of the corners are different in the width direction of the long film.

[2] The long film according to [1], wherein a variation in the distance between the corners in the width direction of the long film is 1.00mm or less.

[3] The long film according to [1] or [2], wherein when a first virtual straight line passing through the first position and the second position is drawn by a line 3 times the width of the uneven portion, the second corner portion, the fourth corner portion, and the sixth corner portion are located on the first virtual straight line,

When a second virtual straight line passing through the third position and the fourth position is drawn by a line 3 times the width of the concave-convex portion, the ninth corner, the tenth corner, and the tenth corner are located on the second virtual straight line.

[4] The long film according to any one of [1] to [3], wherein when a first virtual circle having a diameter which is a first virtual line segment connecting the first position and the second corner is drawn by a line having a width 3 times larger than the width of the concave-convex portion, the first corner is located on the first virtual circle,

When a second virtual circle having a diameter of a second virtual line segment connecting the second corner and the fourth corner is drawn by a line 3 times the width of the concave-convex portion, the third corner is located on the second virtual circle,

When a third virtual circle having a diameter of a third virtual line segment connecting the fourth corner and the sixth corner is drawn by a line having a width 3 times larger than the width of the concave-convex portion, the fifth corner is located on the third virtual circle,

In the case where a fourth virtual circle having a diameter which is a fourth virtual line segment connecting the sixth corner and the second position is drawn by a line having a width 3 times larger than the width of the concave-convex portion, the seventh corner is located on the fourth virtual circle,

When a fifth virtual circle having a diameter which is a fifth virtual line segment connecting the third position and the ninth corner is drawn by a line having a width 3 times larger than the width of the concave-convex portion, the eighth corner is located on the fifth virtual circle,

In the case where a sixth virtual circle having a diameter of a sixth virtual line segment connecting the ninth corner and the tenth corner is drawn by a line 3 times larger than the width of the concave-convex portion, the tenth corner is located on the sixth virtual circle,

When a seventh virtual circle having a diameter of a seventh virtual line segment connecting the tenth corner and the tenth corner is drawn by a line 3 times larger than the width of the concave-convex portion, the twelfth corner is located on the seventh virtual circle,

When an eighth virtual circle having a diameter which is an eighth virtual line segment connecting the tenth triangle and the fourth location is drawn by a line having a width 3 times larger than the width of the concave-convex portion, the fourteenth corner is located on the eighth virtual circle.

[5] The long film according to [4], wherein diameters from the first virtual circle to the eighth virtual circle are equal.

[6] The elongated film according to any one of [1] to [5], wherein the first string part and the second string part do not intersect.

[7] The long film according to any one of [1] to [6], wherein the long film has a base layer formed of a cyclic olefin resin or a (meth) acrylic resin.

Effects of the invention

According to the present invention, a long film excellent in winding property can be provided.

Drawings

Fig. 1 is a plan view schematically showing a state of an elongated film according to an embodiment of the present invention as viewed from a thickness direction of the elongated film.

Fig. 2 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 3 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 4 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed in a thickness direction of the elongated film.

Fig. 5 is an enlarged plan view schematically showing an example of a first corner portion of a knurled portion provided in an elongated film according to an embodiment of the present invention.

Fig. 6 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed in a thickness direction of the elongated film.

Fig. 7 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed in a thickness direction of the elongated film.

Fig. 8 is a plan view schematically showing how the irradiation point P of the laser beam irradiated for forming a certain corner moves.

Fig. 9 is a plan view schematically showing how the irradiation point P of the laser beam irradiated for forming a certain straight line portion moves.

Fig. 10 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 11 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to an embodiment of the present invention, as viewed in a thickness direction of the elongated film.

Fig. 12 is a cross-sectional view schematically showing a cross-section of a linear uneven portion included in a knurled portion of an elongated film according to an embodiment of the present invention, taken along a plane perpendicular to the extending direction of the uneven portion.

Fig. 13 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to another embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 14 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to another embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 15 is a plan view schematically showing a planar shape of one of knurled portions of an elongated film according to another embodiment of the present invention, as viewed from a thickness direction of the elongated film.

Fig. 16 is a plan view enlarged and schematically showing the first straight line portion and the second straight line portion included in the knurled portion.

Fig. 17 is an enlarged and schematic plan view showing the first straight line portion and the second straight line portion included in the knurled portion.

Fig. 18 is a plan view schematically showing an example of a knurled portion according to an embodiment of the present invention as viewed from the thickness direction of the long film.

Fig. 19 is a plan view schematically showing a planar shape of another example of the knurled section according to an embodiment of the present invention, as viewed from the thickness direction of the long film.

Fig. 20 is a schematic plan view showing the planar shape of the knurled section formed in embodiment 1 of the present invention.

Fig. 21 is a schematic plan view showing the planar shape of the knurled section formed in embodiment 1 of the present invention.

Fig. 22 is a schematic plan view showing the planar shape of the knurled section formed in embodiment 2 of the present invention.

Fig. 23 is a schematic plan view showing the planar shape of the knurled section formed in embodiment 2 of the present invention.

Fig. 24 is a schematic plan view showing the planar shape of the knurled portion formed in comparative example 1.

Detailed Description

The present invention will be described in detail below with reference to the embodiments and examples, but the present invention is not limited to the embodiments and examples described below and can be arbitrarily modified and implemented without departing from the scope of the claims and their equivalents.

In the following description, the term "long film" refers to a film having a length of 5 times or more, preferably 10 times or more, with respect to the width, and specifically refers to a film having a length of such a degree that it can be stored or transported while being wound into a roll. The upper limit of the length of the long film is not particularly limited, and for example, the length of the long film may be 10 ten thousand times or less with respect to the width.

In the following description, unless otherwise stated, the planar shape of the knurled portion formed on the film indicates the shape of the knurled portion as viewed from the thickness direction of the film

In the following description, unless otherwise specified, "thickness direction" means the thickness direction of the film.

In the following description, "(meth) acrylic acid" is a term containing "acrylic acid", "methacrylic acid" and combinations thereof, and "(meth) acrylic acid ester" is a term containing "acrylic acid ester", "methacrylic acid ester" and combinations thereof, unless otherwise specified.

[ 1] Embodiment of an elongated film

Fig. 1 is a plan view schematically showing a state of the long film 1 according to an embodiment of the present invention as viewed from the thickness direction thereof.

As shown in fig. 1, the long film 1 is a long film, and has a plurality of knurled portions 10 on at least one surface 1U. These multiple knurled portions 10 are generally arranged in the longitudinal direction MD of the long film 1. The knurled portion 10 is generally provided at least one end portion, preferably at both end portions, of the elongated film 1 in the width direction TD. The planar shape of each knurled portion 10 may be different when viewed from the thickness direction, and in the present embodiment, the same planar shape of the knurled portion 10 is shown.

Fig. 2 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to one embodiment of the present invention. As shown in fig. 2, the knurled portion 10 is formed of a continuous linear concave-convex portion 20. These concave-convex portions 20 can be formed by irradiation of laser light. Therefore, the concave-convex portion 20 is generally formed as a line having a continuous stroke shape as a locus of movement of the irradiation point of the laser light. Here, "one stroke shape" means a shape of a line continuous without interruption in the middle. The knurled portion 10 has a specific planar shape described by the linear concave-convex portion 20.

Specifically, the planar shape of the knurled section 10 as viewed from the thickness direction of the elongated film 1 includes a first wire group section 100 and a second wire group section 200. The planar shape of the knurled section 10 as viewed from the thickness direction may further include an arbitrary portion in combination with the first wire group section 100 and the second wire group section 200. In the present embodiment, an example is shown in which the planar shape of the knurled section 10 as viewed in the thickness direction includes the first connection section 300 and the second connection section 400 that connect the first wire group section 100 and the second wire group section 200, and description is made.

Fig. 3 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to the embodiment of the present invention. In fig. 3, the first wire group unit 100 is shown by a solid line, and the second wire group unit 200, the first connection unit 300, and the second connection unit 400 are shown by a broken line.

As shown in fig. 3, the first line group portion 100 includes a first straight line portion 111, a second straight line portion 112, a third straight line portion 113, a fourth straight line portion 114, a fifth straight line portion 115, a sixth straight line portion 116, a seventh straight line portion 117, and an eighth straight line portion 118.

The first straight portion 111 extends linearly from the first position 121 to the first corner 131. Therefore, the first linear portion 111 may be a linear line segment having the first position 121 at one end and the first corner 131 at the other end. The first location 121 is a location on the first wire set portion 100, typically the end of the first wire set portion 100. The first corner 131 is a connecting portion connecting the first straight portion 111 and the second straight portion 112. The first corner 131 may correspond to a vertex of an angle formed between the first straight line portion 111 and the second straight line portion 112. Accordingly, the first corner 131 has an angle θ ₁₃₁ corresponding to the direction in which the first straight line portion 111 extends and the direction in which the second straight line portion 112 extends.

The second straight portion 112 extends linearly from the first corner portion 131 to the second corner portion 132. Accordingly, the second linear portion 112 may be a linear line segment having the first corner 131 at one end and the second corner 132 at the other end. The second corner 132 is a connecting portion connecting the second straight portion 112 and the third straight portion 113. The second corner 132 may correspond to an apex of an angle formed between the second straight line portion 112 and the third straight line portion 113. Accordingly, the second corner portion 132 has an angle θ ₁₃₂ corresponding to the direction in which the second straight portion 112 extends and the direction in which the third straight portion 113 extends.

The third linear portion 113 extends linearly from the second corner portion 132 to the third corner portion 133. Therefore, the third linear portion 113 may be a linear line segment having the second corner portion 132 at one end and the third corner portion 133 at the other end. The third corner 133 is a connecting portion connecting the third linear portion 113 and the fourth linear portion 114. The third corner 133 may correspond to a vertex of an angle formed between the third linear portion 113 and the fourth linear portion 114. Therefore, the third corner 133 has an angle θ ₁₃₃ corresponding to the direction in which the third straight line portion 113 extends and the direction in which the fourth straight line portion 114 extends.

The fourth linear portion 114 extends linearly from the third corner 133 to the fourth corner 134. Therefore, the fourth linear portion 114 may be a linear line segment having the third corner 133 at one end and the fourth corner 134 at the other end. The fourth corner 134 is a connecting portion connecting the fourth straight line 114 and the fifth straight line 115. The fourth corner 134 may correspond to a vertex of the corner formed between the fourth straight line portion 114 and the fifth straight line portion 115. Therefore, the fourth corner 134 has an angle θ ₁₃₄ corresponding to the direction in which the fourth straight line 114 extends and the direction in which the fifth straight line 115 extends.

The fifth linear portion 115 extends linearly from the fourth corner 134 to the fifth corner 135. Therefore, the fifth linear portion 115 may be a linear line segment having the fourth corner 134 at one end and the fifth corner 135 at the other end. The fifth corner 135 is a connecting portion connecting the fifth straight line 115 and the sixth straight line 116. The fifth corner 135 may correspond to a vertex of an angle formed between the fifth straight line 115 and the sixth straight line 116. Accordingly, the fifth corner portion 135 has an angle θ ₁₃₅ corresponding to the direction in which the fifth straight line portion 115 extends and the direction in which the sixth straight line portion 116 extends.

The sixth straight portion 116 extends linearly from the fifth corner 135 to the sixth corner 136. Accordingly, the sixth linear portion 116 may be a linear line segment having the fifth corner 135 at one end and the sixth corner 136 at the other end. The sixth corner 136 is a connecting portion connecting the sixth straight portion 116 and the seventh straight portion 117. The sixth corner 136 may correspond to a vertex of an angle formed between the sixth straight line portion 116 and the seventh straight line portion 117. Accordingly, the sixth corner 136 has an angle θ ₁₃₆ corresponding to the direction in which the sixth straight line portion 116 extends and the direction in which the seventh straight line portion 117 extends.

The seventh straight portion 117 extends linearly from the sixth corner 136 to the seventh corner 137. Accordingly, the seventh straight line portion 117 may be a straight line segment having the sixth corner portion 136 at one end and the seventh corner portion 137 at the other end. The seventh corner 137 is a connecting portion connecting the seventh straight portion 117 and the eighth straight portion 118. The seventh corner 137 may correspond to a vertex of an angle formed between the seventh straight line portion 117 and the eighth straight line portion 118. Therefore, the seventh corner 137 has an angle θ ₁₃₇ corresponding to the direction in which the seventh straight line 117 extends and the direction in which the eighth straight line 118 extends.

The eighth linear portion 118 extends linearly from the seventh corner portion 137 to the second position 122. Accordingly, the eighth linear portion 118 may be a linear line segment having the seventh corner portion 137 at one end and the second position 122 at the other end. The second position 122 is a position on the first string part 100, and may be an end of the first string part 100.

Fig. 4 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to one embodiment of the present invention. In fig. 4, the second wire group portion 200 is shown by a solid line, and the first wire group portion 100, the first connection portion 300, and the second connection portion 400 are shown by a broken line.

As shown in fig. 4, the second line group portion 200 includes a ninth straight line portion 211, a tenth straight line portion 212, an eleventh straight line portion 213, a twelfth straight line portion 214, a thirteenth straight line portion 215, a fourteenth straight line portion 216, a fifteenth straight line portion 217, and a sixteenth straight line portion 218.

The ninth straight portion 211 extends linearly from the third position 221 to the eighth angle portion 231. Therefore, the ninth straight portion 211 may be a straight line segment having the third position 221 at one end and the eighth angle portion 231 at the other end. The third position 221 is a position on the second wire group part 200, and is typically one end of the second wire group part 200. The eighth angle 231 is a connecting portion connecting the ninth straight line 211 and the tenth straight line 212. The eighth corner 231 may correspond to a vertex of an angle formed between the ninth straight line portion 211 and the tenth straight line portion 212. Therefore, the eighth angled portion 231 has an angle θ ₂₃₁ corresponding to the direction in which the ninth straight portion 211 extends and the direction in which the tenth straight portion 212 extends.

The tenth straight portion 212 extends linearly from the eighth corner portion 231 to the ninth corner portion 232. Therefore, the tenth straight line portion 212 may be a straight line segment having the eighth corner portion 231 at one end and the ninth corner portion 232 at the other end. The ninth corner 232 is a connecting portion connecting the tenth straight portion 212 and the eleventh straight portion 213. The ninth corner 232 may correspond to a vertex of an angle formed between the tenth straight portion 212 and the eleventh straight portion 213. Therefore, the ninth corner 232 has an angle θ ₂₃₂ corresponding to the direction in which the tenth straight line 212 extends and the direction in which the eleventh straight line 213 extends.

The eleventh straight portion 213 extends straight from the ninth corner 232 to the tenth corner 233. Therefore, the eleventh straight line portion 213 may be a straight line segment having the ninth corner portion 232 at one end and the tenth corner portion 233 at the other end. The tenth corner 233 is a connecting portion connecting the eleventh straight portion 213 and the twelfth straight portion 214. The tenth corner 233 may correspond to a vertex of an angle formed between the eleventh straight line portion 213 and the twelfth straight line portion 214. Therefore, the tenth corner 233 has an angle θ ₂₃₃ corresponding to the direction in which the eleventh straight line 213 extends and the direction in which the twelfth straight line 214 extends.

The twelfth linear portion 214 extends linearly from the tenth corner portion 233 to the eleventh corner portion 234. Therefore, the twelfth linear portion 214 may be a linear line segment having the tenth corner portion 233 at one end and the eleventh corner portion 234 at the other end. The eleventh corner 234 is a connecting portion connecting the twelfth straight portion 214 and the thirteenth straight portion 215. The eleventh corner 234 may correspond to a vertex of the angle formed between the twelfth straight line 214 and the thirteenth straight line 215. Therefore, the eleventh corner 234 has an angle θ ₂₃₄ corresponding to the direction in which the twelfth straight line 214 extends and the direction in which the thirteenth straight line 215 extends.

The thirteenth linear portion 215 extends linearly from the eleventh corner portion 234 to the twelfth corner portion 235. Therefore, the thirteenth linear portion 215 may be a linear line segment having the eleventh corner 234 at one end and the twelfth corner 235 at the other end. The twelfth corner 235 is a connecting portion connecting the thirteenth straight portion 215 and the fourteenth straight portion 216. The twelfth corner 235 may correspond to a vertex of the angle formed between the thirteenth straight line portion 215 and the fourteenth straight line portion 216. Therefore, the twelfth corner 235 has an angle θ ₂₃₅ corresponding to the direction in which the thirteenth straight line portion 215 extends and the direction in which the fourteenth straight line portion 216 extends.

The fourteenth straight portion 216 extends linearly from the twelfth corner portion 235 to the thirteenth corner portion 236. Therefore, the fourteenth straight portion 216 may be a straight line segment having the twelfth corner portion 235 at one end and the thirteenth corner portion 236 at the other end. The thirteenth corner 236 is a connecting portion connecting the fourteenth straight portion 216 and the fifteenth straight portion 217. The thirteenth corner 236 may correspond to a vertex of an angle formed between the fourteenth straight portion 216 and the fifteenth straight portion 217. Accordingly, the thirteenth corner portion 236 has an angle θ ₂₃₆ corresponding to the direction in which the fourteenth straight portion 216 extends and the direction in which the fifteenth straight portion 217 extends.

The fifteenth straight portion 217 extends linearly from the thirteenth corner portion 236 to the fourteenth corner portion 237. Therefore, the fifteenth linear portion 217 may be a linear line segment having the thirteenth corner portion 236 at one end and the fourteenth corner portion 237 at the other end. The fourteenth corner 237 is a connecting portion connecting the fifteenth straight portion 217 and the sixteenth straight portion 218. The fourteenth corner 237 may correspond to a vertex of the angle formed between the fifteenth straight portion 217 and the sixteenth straight portion 218. Therefore, the fourteenth corner portion 237 has an angle θ ₂₃₇ corresponding to the direction in which the fifteenth straight portion 217 extends and the direction in which the sixteenth straight portion 218 extends.

The sixteenth straight portion 218 extends linearly from the fourteenth corner 237 to the fourth location 222. Accordingly, the sixteenth straight portion 218 may be a straight line segment having the fourteenth corner 237 at one end and the fourth position 222 at the other end. The fourth position 222 may be a position on the second wire group part 200 or may be one end of the second wire group part 200.

The angle θ ₁₃₁ of the first corner 131, the angle θ ₁₃₂ of the second corner 132, the angle θ ₁₃₃ of the third corner 133, the angle θ ₁₃₄ of the fourth corner 134, the angle θ ₁₃₅ of the fifth corner 135, the angle θ ₁₃₆ of the sixth corner 136, the angle θ ₁₃₇ of the seventh corner 137, the angle θ ₂₃₁ of the eighth corner 231, the angle θ ₂₃₂ of the ninth corner 232, the angle θ ₂₃₃ of the tenth corner 233, the angle θ ₂₃₄ of the eleventh corner 234, the angle θ ₂₃₅ of the twelfth corner 235, the angle θ ₂₃₆ of the thirteenth corner 236, and the angle θ ₂₃₇ of the tenth corner 237 are each independently within a specific angular range. The specific angle range is usually 80 ° or more, preferably 85 ° or more, more preferably 88 ° or more, and is usually 100 ° or less, preferably 95 ° or less, more preferably 92 ° or less. Of these, 90 ° is particularly preferable. The angles θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ from the first to fourteenth corners 131 to 137, 231 to 237 may be the same or different.

In the present specification, unless otherwise specified, "angle of corner" means an angle at which 2 straight lines connected by the corner intersect (angle of 0 ° -180 ° at the corner). The corners are sharp corners when viewed macroscopically, but can be rounded when viewed microscopically. In the case where the corner portions are rounded, unless otherwise specified, the angle at which the extended lines intersect indicates the angle of the corner portion in order to extend 2 straight lines at which the corner portions intersect when viewed macroscopically.

Fig. 5 is an enlarged plan view schematically showing an example of the first corner 131 of the knurled section 10 provided in the long film 1 according to the embodiment of the present invention. For example, as in the example shown in fig. 5, when the first corner 131 connecting the first straight line portion 111 and the second straight line portion 112 is rounded, 2 straight line portions (i.e., the first straight line portion 111 and the second straight line portion 112) intersecting at the first corner 131 in a macroscopic view are elongated, and the angle at which the elongated lines 111a and 112a intersect represents the angle θ ₁₃₁ of the first corner 131.

When the first to fourteenth corners 131 to 137, 231 to 237 are rounded, the radius of curvature R of these corners 131 to 137, 231 to 237 is preferably controlled to be within a specific range. The radius of curvature R is preferably in the range of 0.0mm to 0.5mm, more preferably 0.0mm to 0.2mm, particularly preferably 0.0mm to 0.1mm. As shown in fig. 5, the radius of curvature of the corner portion indicates the radius of curvature R of the rounded portion of the corner portion unless otherwise specified.

The first wire group portion 100 and the second wire group portion 200 having the planar shape described above may be each a zigzag-shaped wire portion including a plurality of continuous straight portions. The first wire group part 100 and the second wire group part 200 may have a plurality of corners at positions corresponding to the apexes of the corners of the zigzag shape. By including the first wire group portion 100 and the second wire group portion 200 having such a planar shape, the knurled portion 10 can include a plurality of corner portions at a high density (the number of corner portions per unit area).

Fig. 6 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to the embodiment of the present invention. In fig. 6, the first connection portion 300 and the second connection portion 400 are indicated by solid lines, and the first wire group portion 100 and the second wire group portion 200 are indicated by broken lines.

As shown in fig. 6, the planar shape of the knurled section 10 of the present embodiment, as viewed from the thickness direction, can include a first connection section 300 connecting the first position 121 of the first wire group section 100 and the fourth position 222 of the second wire group section 200, and a second connection section 400 connecting the second position 122 of the first wire group section 100 and the third position 221 of the second wire group section 200.

The shape of the first connection part 300 is not limited. From the viewpoint of forming the first connecting portion 300 in a short time to shorten the forming time of the knurled portion 10, the first connecting portion 300 preferably includes linear line segments 311, 312, and 313.

The line segment 311 connected to the first line segment 100 at the first position 121 may extend parallel to the first straight line 111 extending from the first position 121 or may extend non-parallel to the first straight line. When the line segment 311 extends non-parallel to the first line segment 111, a corner can be formed at the first position 121 where the first line segment 111 and the line segment 311 are connected. The angle θ ₁₂₁ of the corner is preferably within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131. The angle θ ₁₂₁ of the corner that can be formed at the first position 121 may be the same as or different from the angle θ ₁₃₁ of the first corner 131.

The line segment 313 connected to the second wire group 200 at the fourth position 222 may extend parallel to a linear portion (sixteenth linear portion 218 in the present embodiment) in the second wire group 200 extending from the fourth position 222, or may extend non-parallel. When the line segment 313 extends in a non-parallel manner to the linear portion in the second line group 200 extending from the fourth position 222, a corner (not shown) can be formed at the fourth position 222 connecting the linear portion and the line segment 313. The angle θ ₂₂₂ (not shown) of the corner is preferably within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131. The angle θ ₂₂₂ of the corner portion that can be formed at the fourth position 222 may be the same as or different from the angle θ ₁₃₁ of the first corner portion 131.

The first connection portion 300 may have corners 331 and 332 at the connection portions of the line segments 311, 312, and 313 included in the first connection portion 300. The angles θ ₃₃₁ and θ ₃₃₂ of the corners 311 and 312 included in the first connection portion 300 are preferably independently within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131, respectively. The angles θ ₃₃₁ and θ ₃₃₂ of the corners 331 and 332 may be the same or different from the angle θ ₁₃₁ of the first corner 131. In addition, angles θ ₃₃₁ and θ ₃₃₂ of corners 331 and 332 may be the same or different.

The shape of the second connection part 400 is not limited. From the viewpoint of forming the second connecting portion 400 in a short time to shorten the forming time of the knurled portion 10, the second connecting portion 400 preferably includes linear line segments 411, 412, and 413.

The line segment 411 connecting to the first line segment 100 at the second position 122 may extend parallel to the linear portion (the eighth linear portion 118 in the present embodiment) in the first line segment 100 extending from the second position 122, or may extend non-parallel. When the line segment 411 extends in a non-parallel manner to the linear portion in the first line group portion 100 extending from the second position 122, a corner (not shown) may be formed at the second position 122 where the linear portion and the line segment 411 are connected. The angle θ ₁₂₂ (not shown) of the corner is preferably within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131. The angle θ ₁₂₂ of the corner that can be formed at the second position 122 may be the same as or different from the angle θ ₁₃₁ of the first corner 131.

The line segment 413 connected to the second line segment 200 at the third position 221 may extend parallel to the ninth straight line portion 211 extending from the third position 221, or may extend non-parallel. When the line segment 413 extends non-parallel to the ninth straight line portion 211, a corner portion can be formed at the third position 221 where the ninth straight line portion 211 and the line segment 413 are connected. The angle θ ₂₂₁ of the corner is preferably within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131. The angle θ ₂₂₁ of the corner portion that can be formed at the third position 221 may be the same as or different from the angle θ ₁₃₁ of the first corner portion 131.

The second connection portion 400 may have corners 431 and 432 at the connecting portions of the line segments 411, 412, and 413 included in the second connection portion 400. The angles θ ₄₃₁ and θ ₄₃₂ of the corners 431 and 432 included in the second connection part 400 are preferably independently within the same specific angular range as the range of the angle θ ₁₃₁ of the first corner 131, respectively. The angles θ ₄₃₁ and θ ₄₃₂ of the corners 431 and 432 may be the same or different from the angle θ ₁₃₁ of the first corner 131. In addition, angles θ ₄₃₁ and θ ₄₃₂ of corners 431 and 432 may be the same or different.

Fig. 7 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to one embodiment of the present invention. In fig. 7, the axis a _TD extending in the width direction TD is shown together with the knurled portion 10 in order to easily grasp the position of the long film 1 in the width direction TD. As shown in fig. 7, the positions of the first corner 131, the second corner 132, the third corner 133, the fourth corner 134, the fifth corner 135, the sixth corner 136, the seventh corner 137, the eighth corner 231, the ninth corner 232, the tenth corner 233, the eleventh corner 234, the twelfth corner 235, the thirteenth corner 236, and the fourteenth corner 237 are all different in the width direction TD of the elongated film 1. When the first string part 100 and the second string part 200 have any corner (for example, the corner of the first position 121, the corner of the third position 221, etc.) in addition to the first to tenth corner 131 to 137 and 231 to 237, it is preferable to include any corner, and the positions of all the corners included in the first string part 100 and the second string part 200 are different in the width direction TD. Further, in the case where the first connecting portion 300 and the second connecting portion 400 have the corner portions 331, 332, 431, and 432, it is preferable to include these corner portions 331, 332, 431, and 432, and positions of all the corner portions included in the knurled portion 10 are different in the width direction TD.

The long film 1 having the knurled portion 10 is excellent in winding property. The present inventors speculate about the mechanism for obtaining excellent windability as described above as follows. The technical scope of the present invention is not limited by the mechanisms described below.

Fig. 8 is a plan view schematically showing how the irradiation point P of the laser beam irradiated for forming a certain corner moves. Fig. 9 is a plan view schematically showing how the irradiation point P of the laser beam irradiated for forming a certain straight line portion moves. In fig. 8 and 9, the irradiation point P is shown moving in the directions indicated by arrows A1 and A2.

As shown in fig. 8 and 9, when the concave-convex portion 20 continuous in a linear shape is formed, the laser beam is irradiated onto the film while moving the irradiation point P of the laser beam. As shown in fig. 9, in the case of forming the straight portion, the irradiation point P moves in a straight line. On the other hand, when the corner is formed, the irradiation point P moves so as to turn at an appropriate angle. When the irradiation point P is moved in a cornering manner, the irradiation time of the laser light is prolonged at the inner part in the moving direction, and thus the energy density of the irradiated laser light is increased. Therefore, the height H (see fig. 12) of the concave-convex portion 20 becomes high at the corner.

The knurled portion 10 of the above embodiment includes the first to fourteenth corner portions 131 to 137, 231 to 237 each having an angle θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ close to 90 °. According to the study of the present inventors, it was found that the smaller the angle of the corner portion, the higher the corner portion can be. Thus, the first to fourteenth corners 131 to 137, 231 to 237 having the angle θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ close to 90 ° can have a sufficiently large height. In the above embodiment, the angle θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ of each of the first to fourteenth corners 131 to 137 and 231 to 237 is in the range of approximately 90 °, and the uniformity is excellent. Therefore, the first to fourteenth corners 131 to 137, 231 to 237 can have a high height with excellent uniformity.

In the above embodiment, the first to fourteenth corners 131 to 137, 231 to 237 are provided at different positions in the width direction TD of the long film 1. Therefore, the first to fourteenth corners 131 to 137, 231 to 237 having high uniformity can be widely distributed in the knurled portion 10 in the width direction TD.

When the long film 1 is wound in a roll shape, each knurled portion 10 can support the long film 1. At this time, the first to fourteenth corners 131 to 137, 231 to 237 are in contact with the other layer of the elongated film 1 which is wound and overlapped. Since the first to fourteenth corners 131 to 137 and 231 to 237 are high, the contact pressure of the contact can be increased. Further, since the first to fourteenth corners 131 to 137 and 231 to 237 have good uniformity in height and are widely distributed in the knurled portion 10, the uniformity of the contact pressure can be improved. Therefore, the grip (grip) force between the wound and overlapped long films 1 can be increased and made uniform.

In this way, the above-described gripping force can overcome the stress applied to the roll (for example, the stress in the axial direction due to the weight of the roll) with high strength and high uniformity. Therefore, the rolled long film 1 having the knurled portion 10 can be prevented from being deformed by stress. In this way, in the roll, the uniformity of the thickness of the air layer between the wound and overlapped long films 1 can be improved. Therefore, since the local generation of the thin air layer portion can be suppressed, blocking can be suppressed. Further, since the portion where the air layer thickness is locally generated can be suppressed, occurrence of buckling can be suppressed, and wrinkles can be suppressed. As described above, the long film 1 can achieve excellent windability because blocking and wrinkling can be effectively suppressed.

However, as described above, the smaller the angle of the corner portion, the higher the height of the corner portion can be increased, and therefore, it is also conceivable to make the angle of the corner portion an acute angle smaller than 90 °. However, if the corner portion having an acute angle is formed, it is required to make the other corner portion an obtuse angle greater than 90 ° in order to form the annular knurled portion 10. Therefore, uniformity of the angle of the corner portion is reduced. Further, the scanning distance of the laser light for forming one knurled portion 10 (i.e., the moving distance of the irradiation point P of the laser light to the film before processing) becomes longer, and the time required for forming one knurled portion 10 becomes longer, so that the density of the knurled portion 10 (the number of knurled portions 10 per unit length) becomes smaller. Therefore, in the above case, the grip force may become small, or the uniformity of the grip force may be lowered. In contrast, in the above embodiment, by making the angle θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ of the corners 131 to 137, 231 to 237 close to 90 °, it is accomplished in a balanced manner that the time required to form one knurled portion 10 is shortened, the density of the knurled portion 10 is increased, the heights of the corners 131 to 137, 231 to 237 are increased, and the uniformity of the angle θ ₁₃₁～θ₁₃₇、θ₂₃₁～θ₂₃₇ of the corners 131 to 137, 231 to 237 is improved, thereby realizing a large and uniform gripping force.

In addition, the first to fourteenth corners 131 to 137, 231 to 237 can increase the contact pressure and can improve the uniformity of the contact pressure even when the long film 1 is wound. Therefore, the grip force between the wound and overlapped long films 1 can be made large and uniform. Therefore, winding bias in the width direction TD of the long film 1, or winding and unwinding in the longitudinal direction MD of the long film 1 can be suppressed.

Further, the first to fourteenth corners 131 to 137, 231 to 237 can be brought into contact with a conveying roller (not shown) at the time of conveying the long film 1. At this time, the first to fourteenth corners 131 to 137, 231 to 237 can be brought into contact with the conveying roller with a large and uniform contact pressure. Therefore, since the gripping force (friction force) of the long film 1 against the conveying roller can be made large and uniform, the left-right twist of the long film 1 during conveyance can be suppressed, and high conveyance performance can be achieved.

As described above, the first to fourteenth corners 131 to 137, 231 to 237 are provided at different positions in the width direction TD of the long film 1. Accordingly, as shown in fig. 7, a space D is provided between the first to fourteenth corners 131 to 137 and 231 to 237 in the width direction TD. The distance D represents the distance between 2 adjacent corners in the width direction TD of the long film 1. The interval D is preferably 100 μm or more, more preferably 200 μm or more, particularly preferably 300 μm or more, preferably 3mm or less, more preferably 2mm or less, particularly preferably 1mm or less. When the distance D is within the above range, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, unwinding, and twisting can be effectively suppressed. From the same point of view, it is preferable that the distance D in the width direction TD between all the corners of the first wire group part 100 and the second wire group part 200 including any corner (for example, the corner of the first position 121, the corner of the third position 221, and the like) is controlled in the above range. Further, it is further preferable that the interval D in the width direction TD between all the corners of the knurled section 10 including any corner (for example, the corners 331, 332, 431, 432, etc.) is controlled within the above range.

The interval D may be non-uniform, but preferably has high uniformity. Therefore, the variation in the interval D between the first to fourteenth corners 131 to 137 and 231 to 237 in the width direction TD is preferably small. The deviation of the interval D represents the difference between the maximum value and the minimum value of the interval D between the corners of one knurled portion 10. The deviation of the interval D between the first to fourteenth corners 131 to 137, 231 to 237 is preferably 0.00mm to 1.00mm, more preferably 0.00mm to 0.50mm, particularly preferably 0.00mm to 0.20mm. When the variation in the interval D falls within the above range, the windability of the long film 1 can be effectively improved, and the winding bias, winding up, unwinding, and twisting can be effectively suppressed in general. From the same point of view, it is preferable that the variation of the interval D in the width direction TD between all the corners of the first wire group part 100 and the second wire group part 200 including any corner (for example, the corner of the first position 121, the corner of the third position 221, and the like) is controlled in the above range. Further, it is further preferable that the variation of the interval D in the width direction TD between all the corners of the knurled section 10 including any corner (for example, the corners 331, 332, 431, 432, etc.) is controlled within the above range.

The first wire set portion 100 and the second wire set portion 200 included in the same knurled portion 10 preferably do not intersect. That is, the first string part 100 and the second string part 200 are preferably separated from each other by being formed at different positions. When the first string part 100 and the second string part 200 do not intersect, the range of the first to tenth corner parts 131 to 137, 231 to 237 can be widened, and therefore the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, winding down, and twisting right and left can be effectively suppressed.

The first string part 100 and the second string part 200 included in the same knurled part 10 are preferably formed at different positions in the longitudinal direction MD of the long film 1. In this case, by irradiating the laser light so as to reciprocate the irradiation point P, the first line group portion 100 and the second line group portion 200 can be formed. For example, the first line group portion 100 can be formed on the way of the irradiation point P, and the second line group portion 200 can be formed on the way of the return. Therefore, the irradiation start position and the irradiation end position of the laser light forming the concave-convex portion 20 of the knurled portion 10 can be made close to each other in the width direction TD of the long film 1. Therefore, the adjustment amount of the optical system (the angle adjustment amount of the mirror, etc.) in which the irradiation point P of the laser light for forming the next knurled section 10 moves after forming one knurled section 10 can be reduced. Therefore, the interval from the formation of one knurled portion 10 to the formation of the next knurled portion 10 can be shortened, and thus the density of the knurled portions 10 (the number of knurled portions 10 per unit length) can be increased.

Fig. 10 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1, as viewed from the thickness direction of the long film 1 according to one embodiment of the present invention. In fig. 10, the first wire group unit 100 is shown by a solid line, and the second wire group unit 200, the first connection unit 300, and the second connection unit 400 are shown by a broken line.

As indicated by a two-dot chain line in fig. 10, a case is assumed in which a first virtual straight line 140 passing through the first position 121 and the second position 122 is drawn with a specific thickness. In this case, it is preferable that the second corner 132, the fourth corner 134, and the sixth corner 136 are on the first virtual straight line 140. Unless otherwise specified, "the corner portion is on the virtual straight line" means that the position of a part or all of the corner portion coincides with the position of the virtual straight line. The line thickness of the first virtual straight line 140 is preferably 3 times or less, more preferably 2 times or less, still more preferably 1.5 times or less, and still more preferably 0.1mm or more the width W (see fig. 12) of the concave-convex portion 20.

The above-described requirement for the first virtual straight line 140 indicates that the first position 121, the second position 122, the second corner 132, the fourth corner 134, and the sixth corner 136 are arranged with high regularity. Specifically, the first position 121, the second position 122, the second corner 132, the fourth corner 134, and the sixth corner 136 can be on a straight line represented by a first virtual straight line 140. However, even if there is an error in the positions of the first position 121, the second position 122, the second corner 132, the fourth corner 134, and the sixth corner 136, the desired effect can be obtained. The range of preferred accuracy including this error is represented by the thickness of the line of the first virtual straight line 140. Specifically, the thinner the line of the first virtual straight line 140, the more accurate (i.e., with small error) the first position 121, the second position 122, the second corner 132, the fourth corner 134, and the sixth corner 136 are on one straight line.

When the knurled section 10 has a planar shape of the first string section 100 satisfying the above-described requirement of the first virtual straight line 140, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, winding down, and left-right twisting can be effectively suppressed. Further, the knurled portion 10 having a planar shape satisfying the requirement can shorten the length of the concave-convex portion 20 for forming the knurled portion 10, and thus can be formed in a short time.

Fig. 11 is a plan view schematically showing a planar shape of one of the knurled sections 10 of the long film 1 as viewed from the thickness direction of the long film 1 according to one embodiment of the present invention. In fig. 11, the second wire group portion 200 is shown by a solid line, and the first wire group portion 100, the first connection portion 300, and the second connection portion 400 are shown by a broken line.

The second string part 200 preferably satisfies the virtual straight line requirement in the same manner as the first string part 100. Specifically, as indicated by a two-dot chain line in fig. 11, a case is assumed in which the second virtual straight line 240 passing through the third position 221 and the fourth position 222 is drawn with a thickness of a specific width. In this case, it is preferable that the ninth corner 232, the eleventh corner 234, and the thirteenth corner 236 are on the second virtual straight line 240. The range of the thickness of the line of the second virtual straight line 240 can be the same as the range of the thickness of the line of the first virtual straight line 140. The thickness of the first virtual straight line 140 may be the same as or different from the thickness of the second virtual straight line 240.

The above-described requirement for the second virtual straight line 240 is the same as the requirement for the first virtual straight line 140, and indicates that the arrangement of the third position 221, the fourth position 222, the ninth corner 232, the eleventh corner 234, and the thirteenth corner 236 is highly regular. Specifically, the third position 221, the fourth position 222, the ninth corner 232, the eleventh corner 234, and the tenth corner 236 can be located on a single line represented by the second virtual line 240 within a range of preferable accuracy represented by the thickness of the second virtual line 240.

In the case where the knurled section 10 has the planar shape of the second string section 200 satisfying the above-described requirement of the second virtual straight line 240, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, winding down, and left-right twisting can be effectively suppressed. Further, the knurled portion 10 having a planar shape satisfying the requirement can shorten the length of the concave-convex portion 20 for forming the knurled portion 10, and can be formed in a short time.

As indicated by a two-dot chain line in fig. 10, a first virtual line segment 141 connecting the first position 121 and the second corner 132 is assumed. Further, as indicated by a one-dot chain line in fig. 10, a case is assumed in which a first virtual circle 151 having a diameter of the first virtual line segment 141 is drawn with a specific thickness. The first virtual circle 151 is a circle having a diameter equal to the length of the first virtual line segment 141 with respect to a circle centered on the midpoint of the first virtual line segment 141. In this case, it is preferable that the first corner 131 is on the first virtual circle 151. Unless otherwise specified, the term "the corner is on the virtual circle" means that a part or all of the corner coincides with the position on the virtual circle (i.e., the position of the circle drawn by the line of the specific thickness). The line thickness of the first virtual circle 151 is preferably 3 times or less, more preferably 2 times or less, still more preferably 1.5 times or less, and still more preferably 0.1mm or more the width W (see fig. 12) of the concave-convex portion 20.

The above-described requirement of the first virtual circle 151 indicates that the angle θ ₁₃₁ of the first corner 131 is made close to a right angle. However, even if there is an error in the angle θ ₁₃₁ of the first corner 131, a desired effect can be obtained. The range of preferable accuracy including this error is represented by the thickness of the line of the first virtual circle 151. Specifically, the thinner the line of the first virtual circle 151, the closer to the right angle the angle θ ₁₃₁ representing the first corner 131 is to the high accuracy.

Further, among the corners included in the first wire group portion 100, the other corners of the odd number from the first position 121 are preferably the same as the first corner 131, and satisfy the above-described requirement of the virtual circle.

Specifically, as indicated by a two-dot chain line in fig. 10, a second virtual line segment 142 connecting the second corner 132 and the fourth corner 134 is assumed. Further, as indicated by a one-dot chain line in fig. 10, a case is assumed in which a second virtual circle 152 having the second virtual line segment 142 as a diameter is drawn by a line of a specific thickness. In this case, the third corner 133 is preferably located on the second virtual circle 152.

As indicated by a two-dot chain line in fig. 10, a third virtual line segment 143 connecting the fourth corner 134 and the sixth corner 136 is assumed. Further, as indicated by a one-dot chain line in fig. 10, a case is assumed in which a third virtual circle 153 having a diameter of the third virtual line segment 143 is drawn by a line of a specific thickness. In this case, it is preferable that the fifth corner 135 is on the third virtual circle 153.

As indicated by a two-dot chain line in fig. 10, a fourth virtual line segment 144 connecting the sixth corner 136 and the second position 122 is assumed. Further, as indicated by a one-dot chain line in fig. 10, a case is assumed in which a fourth virtual circle 154 having the diameter of the fourth virtual line segment 144 is drawn by a line of a specific thickness. In this case, it is preferable that the seventh corner 137 be on the fourth virtual circle 154.

The range of the thickness of the line of the second virtual circle 152, the range of the thickness of the line of the third virtual circle 153, and the range of the thickness of the line of the fourth virtual circle 154 can be the same as the range of the thickness of the line of the first virtual circle 151, respectively, independently. The thickness of the line of the first virtual circle 151, the thickness of the line of the second virtual circle 152, the thickness of the line of the third virtual circle 153, and the thickness of the line of the fourth virtual circle 154 may be the same or different.

When the knurled portion 10 has a planar shape of the first string part 100 satisfying the above-described requirement of the virtual circle, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, winding-off, and left-right twisting can be effectively suppressed. Further, the knurled portion 10 having a planar shape satisfying the requirement can shorten the length of the concave-convex portion 20 for forming the knurled portion 10, and thus can be formed in a short time.

The second wire group portion 200 is preferably the same as the first wire group portion 100, and satisfies the requirement of a virtual circle. That is, among the corners included in the second wire group portion 200, the other corners of the odd number from the third position 221 are preferably the same as the first corner 131, and satisfy the requirement of the virtual circle.

Specifically, as indicated by a two-dot chain line in fig. 11, a fifth virtual line segment 241 connecting the third corner 221 and the ninth corner 232 is assumed. Further, as indicated by a one-dot chain line in fig. 11, a case is assumed in which a fifth virtual circle 251 having a diameter of the fifth virtual line segment 241 is drawn by a line of a specific thickness. In this case, the eighth corner 231 is preferably located on the fifth virtual circle 251.

As indicated by a two-dot chain line in fig. 11, a sixth virtual line segment 242 connecting the ninth corner 232 and the eleventh corner 234 is assumed. Further, as indicated by a one-dot chain line in fig. 11, a case is assumed in which a sixth virtual circle 252 having a diameter of the sixth virtual line segment 242 is drawn by a line of a specific thickness. In this case, it is preferable that the tenth corner 233 is on the sixth virtual circle 252.

Further, as indicated by a two-dot chain line in fig. 11, a seventh virtual line segment 243 connecting the eleventh corner 234 and the thirteenth corner 236 is assumed. Further, as indicated by a one-dot chain line in fig. 11, a case is assumed in which a seventh virtual circle 253 having a diameter of the seventh virtual line segment 243 is drawn by a line of a specific thickness. In this case, it is preferable that the twelfth corner 235 be on the seventh virtual circle 253.

As indicated by a two-dot chain line in fig. 11, an eighth virtual line segment 244 connecting the thirteenth corner 236 and the fourth position 222 is assumed. Further, as indicated by a one-dot chain line in fig. 11, a case is assumed in which an eighth virtual circle 254 having the diameter of the eighth virtual line segment 244 is drawn by a line of a specific thickness. In this case, the tenth corner 237 is preferably located on the eighth virtual circle 254.

The range of the thickness of the line of the fifth virtual circle 251, the range of the thickness of the line of the sixth virtual circle 252, the range of the thickness of the line of the seventh virtual circle 253, and the range of the thickness of the line of the eighth virtual circle 254 can be the same as the range of the thickness of the line of the first virtual circle 151, respectively, independently. The thickness of the line of the fifth virtual circle 251, the thickness of the line of the sixth virtual circle 252, the thickness of the line of the seventh virtual circle 253, and the thickness of the line of the eighth virtual circle 254 may be the same or different.

In the case where the knurled portion 10 has a planar shape of the second string part 200 satisfying the above-described requirement of the virtual circle, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, winding-down, and left-right twisting can be effectively suppressed. Further, the knurled portion 10 having a planar shape satisfying the requirement can shorten the length of the concave-convex portion 20 for forming the knurled portion 10, and thus can be formed in a short time.

Further, the diameters of the virtual circles 151 to 154 and 251 to 254 are preferably equal. Therefore, the lengths of the first virtual line segment 141, the second virtual line segment 142, the third virtual line segment 143, the fourth virtual line segment 144, the fifth virtual line segment 241, the sixth virtual line segment 242, the seventh virtual line segment 243, and the eighth virtual line segment 244 are preferably equal. In this case, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, unwinding, and twisting can be effectively suppressed. Further, the knurled portion 10 having a planar shape satisfying the requirement can shorten the length of the concave-convex portion 20 for forming the knurled portion 10, and thus can be formed in a short time.

The planar shape of the knurled section 10 is preferably a ring shape. In the above embodiment, the knurled portion 10 has a ring shape by continuously forming the first wire group portion 100, the second connection portion 400, the second wire group portion 200, and the first connection portion 300 into a ring shape. In the case of forming the knurled portion 10 having the annular shape with the laser light in this way, the irradiation start position and the irradiation end position of the laser light for forming the concave-convex portion 20 of the knurled portion 10 can be set at the same position. Therefore, since the irradiation start position and the irradiation end position can be made to coincide in the width direction TD of the long film 1, the adjustment amount of the optical system (the angle adjustment amount of the mirror, etc.) to move the irradiation point P of the laser light at which the next knurled portion 10 is formed after the one knurled portion 10 is formed can be reduced. Therefore, since the interval from the formation of one knurled portion 10 to the formation of the next knurled portion 10 can be shortened, the density of the knurled portions 10 (the number of knurled portions 10 per unit length) can be increased.

As shown in fig. 2, the ratio L _TD/L_MD of the length L _TD of each knurled portion 10 in the width direction TD of the elongated film 1 to the length L _MD of each knurled portion 10 in the length direction MD of the elongated film 1 is preferably controlled within a specific range. Specifically, the ratio L _TD/L_MD is preferably 2 or more, more preferably 2.5 or more, and particularly preferably 3 or more. In the case where the ratio L _TD/L_MD is controlled in the above range, the deformation can be suppressed and the knurled portion 10 can be easily formed. The upper limit of the ratio L _TD/L_MD is not particularly limited, but is preferably 15 or less, more preferably 13 or less, and particularly preferably 10 or less.

The length L _MD of each knurled portion 10 in the longitudinal direction MD of the long film 1 is preferably small. Specifically, the length L _MD is preferably 20mm or less, more preferably 15mm or less, and particularly preferably 10mm or less. In the case where the length L _MD is small, the length of the concave-convex portion 20 for forming the knurled portion 10 can be shortened. Therefore, the knurled portion 10 can be formed in a short time. Further, since the density of the knurled portion 10 in the longitudinal direction MD of the long film 1 can be increased, the windability of the long film 1 can be effectively improved, and in general, the winding bias, winding up, unwinding, and twisting can be effectively suppressed. The lower limit of the length L _MD is not particularly limited, but is preferably 0.1mm or more, more preferably 0.5mm or more, and particularly preferably 1mm or more.

The length L _TD of each knurled portion 10 in the width direction TD of the long film 1 is preferably set appropriately so that the above ratio L _TD/L_MD is controlled within the above range. Specifically, the length L _TD of each knurled portion 10 in the width direction TD of the long film 1 is preferably 3mm or more, more preferably 5mm or more, particularly preferably 7mm or more, preferably 20mm or less, more preferably 17mm or less, particularly preferably 15mm or less.

As shown in fig. 1, the knurled sections 10 are generally arranged at a specific pitch in the longitudinal direction MD of the long film 1. In this case, the pitch of the knurled sections 10 is preferably 0.5mm or more, more preferably 1mm or more, particularly preferably 1.5mm or more, preferably 10mm or less, more preferably 7mm or less, particularly preferably 5mm or less. The spacing of the knurls 10 may be fixed or may be different.

Fig. 12 is a cross-sectional view schematically showing a cross-section of the linear uneven portion 20 included in the knurled portion 10 of the long film 1 according to an embodiment of the present invention, taken along a plane perpendicular to the extending direction of the uneven portion 20.

As shown in fig. 12, the concave-convex portion 20 forming the knurled portion 10 has concave portions 21 and convex portions 22 provided on both sides of the concave portions 21. In general, the concave portion 21 corresponds to a portion from which the resin is removed by thermal melting or ablation by irradiation with laser light, and the convex portion 22 corresponds to a portion from which the resin flowing by heating by irradiation with the laser light bulges. Since the convex portion 22 protrudes more than the surface 1U of the surrounding long film 1, the substantial thickness of the long film 1 becomes thicker at the concave-convex portion 20. As described above, the windability of the long film 1 can be improved.

The height H of the concave-convex 20 may be uniform or non-uniform. In general, the height H of the concave-convex portion 20 is different between the corner portion and the straight portion of the knurled portion 10. Further, in the corner portions, the height H of the inner convex portion 22 and the outer convex portion 22 may be different.

The average height of the concave-convex portions 20 at the corners of the knurled portion 10 is preferably 1 μm or more, more preferably 2 μm or more, particularly preferably 3 μm or more, preferably 25 μm or less, more preferably 20 μm or less, particularly preferably 15 μm or less. When the average height of the concave-convex portions 20 at the corners is equal to or greater than the lower limit value of the above range, the windability of the long film 1 can be effectively improved, and the winding bias, winding up, unwinding, and twisting can be effectively suppressed in general. When the average height of the concave-convex portions 20 at the corners is equal to or less than the upper limit value of the above range, the winding diameter of the wound roll can be made different between the portion where the knurled portion 10 is formed (for example, the axial end portion of the roll) and the other portion (for example, the axial center portion of the roll), and thus the deformation of the long film 1 can be suppressed.

The average height of the concave-convex portions 20 of the straight portions of the knurled portion 10 is preferably 0.5 μm or more, more preferably 1 μm or more, particularly preferably 1.5 μm or more, preferably 25 μm or less, more preferably 20 μm or less, particularly preferably 15 μm or less. When the average height of the concave-convex portions 20 of the straight portions is equal to or greater than the lower limit value of the above range, the windability of the long film 1 can be effectively improved, and the winding bias, winding up, unwinding, and twisting can be effectively suppressed in general. Further, when the average height of the concave-convex portions 20 of the straight portions is equal to or less than the upper limit value of the above range, the knurled portion 10 can be easily formed while suppressing the deformation.

The width W of the concave-convex portion 20 is preferably 0.1 μm or more, more preferably 0.15 μm or more, particularly preferably 0.2 μm or more, preferably 1 μm or less, more preferably 0.75 μm or less, particularly preferably 0.5 μm or less. When the width W of the concave-convex portion 20 is equal to or greater than the lower limit value of the above range, the windability of the long film 1 can be effectively improved, and the winding bias, winding up, unwinding, and twisting can be effectively suppressed in general. Further, when the width W of the concave-convex portion 20 of the straight portion is equal to or less than the upper limit value of the above range, the knurled portion 10 can be easily formed while suppressing the deformation.

The width and thickness of the long film 1 are not particularly limited, and can be used according to the purpose of use. The width of the long film 1 is preferably 700mm or more, more preferably 1000mm or more, further preferably 1200mm or more, preferably 2500mm or less, more preferably 2200mm or less, further preferably 2000mm or less. The thickness of the long film 1 is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 20 μm or more, preferably 1000 μm or less, more preferably 300 μm or less, still more preferably 150 μm or less.

When the long film 1 is used as an optical film, it is preferable that the long film has high transparency in the region where the knurled portion 10 is not present. Specifically, the total light transmittance of the long film 1 in the above region is preferably 85% to 100%, more preferably 92% to 100%. The haze of the long film 1 in the above region is preferably 0% to 5%, more preferably 0% to 3%, and particularly preferably 0% to 2%. The total light transmittance can be measured according to JIS K7105 by using a "nephelometer NDH-2000" manufactured by Nippon Denshoku industries Co. The haze can be measured using "NDH2000" manufactured by japan electric color industry co.

[ Modification of the strip film ]

While the long film 1 according to the embodiment of the present invention has been described above, the long film may be implemented in a further modified manner. For example, in the above embodiment, the lengths of the straight portions 111 to 118 included in the first wire group portion 100 and the straight portions 211 to 218 included in the second wire group portion 200 may be uniform, or the lengths of these straight portions may be nonuniform. Examples of which are shown below.

Fig. 13 to 15 are plan views schematically showing a planar shape of one of the knurled sections 30 of the long film according to another embodiment of the present invention, as viewed from the thickness direction of the long film. In fig. 14 and 15, the first connection portion 700 and the second connection portion 800 are indicated by broken lines. In fig. 15, a first virtual line 140, a first virtual line 141, a second virtual line 142, a third virtual line 143, a fourth virtual line 144, a second virtual line 240, a fifth virtual line 241, a sixth virtual line 242, a seventh virtual line 243, and an eighth virtual line 244 are indicated by two-dot chain lines. In fig. 15, the first virtual circle 151, the second virtual circle 152, the third virtual circle 153, the fourth virtual circle 154, the fifth virtual circle 251, the sixth virtual circle 252, the seventh virtual circle 253, and the eighth virtual circle 254 are indicated by single-dot chain lines.

As shown in fig. 13 to 15, the knurled section 30 has a planar shape including a first wire group section 500, a second wire group section 600, a first connection section 700, and a second connection section 800.

The first string part 500 has the same planar shape as the first string part 100 of the above embodiment except that the first to eighth string parts 511 to 518 included in the first string part 500 have uneven lengths. Specifically, the straight portions 511 to 518 included in the first string part 500 each have a length different from that of an adjacent straight portion (i.e., a straight portion connected via a corner). Fig. 13 to 15 show examples in which the groups of the first straight line portion 511, the third straight line portion 513, the fifth straight line portion 515, and the seventh straight line portion 517 have the same length, and the groups of the second straight line portion 512, the fourth straight line portion 514, the sixth straight line portion 516, and the eighth straight line portion 518 have the same length, but the lengths are different between the two groups.

The second wire group portion 600 has the same planar shape as the second wire group portion 200 of the above-described embodiment except that the ninth to sixteenth straight portions 611 to 618 included in the second wire group portion 600 are uneven in length. Specifically, the straight portions 611 to 618 included in the second wire group portion 600 have lengths different from those of the adjacent straight portions (i.e., the straight portions connected via the corner portions). Fig. 13 to 15 show examples in which the groups of the ninth straight line portion 611, the eleventh straight line portion 613, the thirteenth straight line portion 615, and the fifteenth straight line portion 617 have the same length, and the groups of the tenth straight line portion 612, the twelfth straight line portion 614, the fourteenth straight line portion 616, and the sixteenth straight line portion 618 have the same length, but the lengths are different between the two groups.

The first and second connection parts 700 and 800 have different planar shapes from the first and second connection parts 300 and 400 of the above-described embodiment, corresponding to the planar shapes of the first and second wire group parts 500 and 600. The preferable requirements required for the first and second connection portions 700 and 800 are the same as those of the first and second connection portions 300 and 400 according to the above embodiment.

The knurled portion 30 including the first wire group portion 500 and the second wire group portion 600 can exhibit the same effects as the knurled portion 10 described in the above embodiment, and has an advantage that the knurled portion 30 can be formed in a short time. Hereinafter, this advantage will be described with reference to the drawings.

Fig. 16 is an enlarged plan view schematically showing the first straight line portion 111 and the second straight line portion 112 included in the knurled portion 10. Fig. 17 is an enlarged plan view schematically showing the first straight line portion 511 and the second straight line portion 512 included in the knurled portion 30. In fig. 16 and 17, for the sake of explanation, the first virtual circle 151 is indicated by a one-dot chain line.

As shown in fig. 16 and 17, in the case where the first corner 131 is 90 °, the first corner 131 is on the first virtual circle 151. As shown in fig. 16, when the diameters of the first virtual circles 151 are the same, the total length of the first straight line portion 111 and the second straight line portion 112 having the same length is relatively long. On the other hand, as shown in fig. 17, the total length of the first straight line portion 511 and the second straight line portion 512 having different lengths is relatively short. Therefore, the first straight line portion 511 and the second straight line portion 512 having different lengths can shorten the scanning distance of the laser light for forming the concave-convex portion 20 (i.e., the moving distance of the irradiation point P of the laser light to the film before processing) compared with the first straight line portion 111 and the second straight line portion 112 having the same length. The same applies to the straight portions other than the first straight portion 511 and the second straight portion 512. Accordingly, the knurled portion 30 including the first wire group portion 500 and the second wire group portion 600 having the linear portions 511 to 518, 611 to 618 with uneven lengths can shorten the scanning distance of the laser light required for forming the knurled portion 30, and thus can be formed in a short time.

In particular, among the adjacent straight portions, a ratio L _S/L_L of the length L _L in the width direction TD of the relatively long straight portion to the length L _S in the width direction of the relatively short straight portion is preferably 1/3 or close thereto. For example, in the example shown in fig. 17, the ratio L _S/L_L of the length L _L in the width direction TD of the long second straight line portion 512 to the length L _S in the width direction TD of the short first straight line portion 511 is preferably 1/3 or close thereto. The ratio L _S/L_L is preferably 1/3.5 or more, more preferably 1/3.3 or more, particularly preferably 1/3.1 or more, preferably 1/2.5 or less, more preferably 1/2.7 or less, particularly preferably 1/2.9 or less. When the ratio L _S/L_L is within the above range, the uniformity of the distance D between the corners in the width direction TD of the long film can be easily improved.

The number of straight portions and corner portions included in the first string part 100 is not limited to the above embodiment, and may be further increased. Therefore, the first string part 100 may include 9 or more straight sections, or may include 8 or more corner sections.

The number of straight portions and corner portions of the second wire group portion 200 is not limited to the above embodiment, and may be further increased. Therefore, the second wire group portion 200 may include 9 or more straight portions or 8 or more corner portions.

As an example of increasing the number of straight portions and corner portions in this way, knurled portions 40 and 50 having a planar shape shown in fig. 18 and 19 can be given.

Further, in the above embodiment, the first wire group part 100 and the second wire group part 200 have the same planar shape, but the first wire group part 100 and the second wire group part 200 may have different planar shapes. Therefore, the number of straight portions of the first string part 100 may be the same as or different from the number of straight portions of the second string part 200. The number of corners of the first wire group part 100 may be the same as or different from the number of corners of the second wire group part 200.

In the above embodiment, the knurled portion 10 includes the first and second connection portions 300 and 400, but the knurled portion may not include the first and second connection portions. Thus, for example, the first position may be in the same position as the third position or the fourth position. Further, for example, the second position may be in the same position as the third position or the fourth position.

Further, the knurled portion 10 may include a curved portion having a curved planar shape in combination with the straight portion and the corner portion. However, from the viewpoint of significantly obtaining the desired effect of the present invention, the planar shape of the knurled portion 10 preferably includes only straight portions and corner portions.

In the above embodiment, the example in which the virtual straight lines 140 and 240 and the virtual line segments 141 to 144, 241 to 244 are parallel to the width direction TD of the long film 1 is shown for the planar shape of the knurled portion 10, but these virtual straight lines 140 and 240 and virtual line segments 141 to 144, 241 to 244 may be non-parallel to the width direction TD. However, the virtual straight lines 140 and 240 and the virtual line segments 141 to 144, 241 to 244 are preferably not parallel to the longitudinal direction MD of the long film 1.

[3 ] Method for producing elongated film ]

The long film can be produced by a production method including, for example, a step of irradiating a film before forming a knurled portion with laser light. Hereinafter, the film before the knurled portion is formed may be appropriately referred to as a "pre-treatment film".

Generally, irradiation with laser light is performed while the pre-treatment film is continuously conveyed in the longitudinal direction of the pre-treatment film. When laser light is irradiated on at least one face of the film before treatment, thermal melting or ablation is locally generated at the position where the laser light is irradiated. Therefore, the convex deformation and concave deformation as the concave-convex portions can be generated in the film before processing at the laser irradiation position.

In the formation of the knurled portion using such a laser, no mechanical force is required, and therefore residual stress in the knurled portion is less likely to remain. Therefore, the occurrence of breakage of the long film starting from the knurled portion can be suppressed. In addition, even when a thin film before treatment is used, film breakage at the time of knurling part formation is easily suppressed. Further, the generation of foreign matter due to the formation of the knurled portion can be suppressed.

When the laser beam is irradiated, the irradiation point P (see fig. 8 and 9) of the film before processing is moved so as to draw the planar shape of the knurled portion to be formed. Accordingly, since the concave-convex portion is formed on the locus where the laser irradiation point P moves, a knurled portion having a desired planar shape can be formed.

When the irradiation point P of the laser beam is moved, the irradiation point P preferably continuously describes the planar shape (one stroke) of the knurled portion along the line. Thereby, the state of irradiation with the laser light can be maintained during the formation of one knurled portion. Therefore, the variation in the shape of the knurled portion can be suppressed, and thus the knurled portion can be stably formed.

The moving speed of the laser irradiation point P can be arbitrarily set within a range where a desired knurled portion can be formed. The specific moving speed is preferably 500mm/s or more, more preferably 1000mm/s or more, particularly preferably 1500mm/s or more, preferably 10000mm/s or less, more preferably 9000mm/s or less, particularly preferably 8000mm/s or less. When the moving speed of the laser irradiation point P is equal to or higher than the lower limit value of the above range, the time taken for drawing can be shortened, and the knurled portion can be formed at high speed. When the moving speed of the laser irradiation point P is equal to or lower than the upper limit value of the above range, generation of an overshoot due to inertia of a movable portion (mirror or the like) included in the laser optical system can be suppressed, and therefore deformation from a desired shape and corner rounding can be suppressed.

Examples of the laser device that is the laser irradiation device include ArF excimer laser device, krF excimer laser device, xeCl excimer laser device, YAG laser device (particularly third harmonic or fourth harmonic), YLF or YVO4 solid-state laser device (particularly third harmonic or fourth harmonic), ti: S laser device, semiconductor laser device, fiber laser device, and carbon dioxide laser device. Among these laser devices, a carbon dioxide laser device is preferable from the standpoint that the power suitable for processing a film can be obtained relatively inexpensively and effectively.

The power of the laser is preferably 1W or more, more preferably 5W or more, further preferably 15W or more, preferably 120W or less, more preferably 100W or less, further preferably 80W or less, further preferably 70W or less. By setting the laser power to the lower limit value or more of the above range, shortage of the laser irradiation amount can be suppressed, and the knurled portion can be stably formed. Further, by setting the power of the laser to the upper limit value or less of the above range, the occurrence of the through hole in the film can be suppressed.

[4 Composition of strip film ]

As the long film, a resin film is generally used. The resin film may be a stretched film or an unstretched film. The resin film may be a single-layer film having only a base layer, or may be a multilayer film further having an optional layer in combination with the base layer.

As the base material layer, a layer formed of a resin is generally used. As such a resin, various resins can be used depending on the use of the long film, and among them, a cyclic olefin resin and a (meth) acrylic resin are preferable. In general, a film having a base layer formed of a cyclic olefin resin or a (meth) acrylic resin tends to be poor in winding property because air is easily taken in during winding. In contrast, if the knurled portion is formed, the winding property can be improved, and in general, the winding bias, winding up, unwinding, and twisting can be effectively suppressed.

The cyclic olefin resin is a resin containing a cyclic olefin polymer. The cyclic olefin polymer is excellent in mechanical properties, heat resistance, transparency, low hygroscopicity, dimensional stability and light weight.

The cyclic olefin polymer means a polymer having an alicyclic structure as a structural unit of the polymer. The cyclic olefin polymer may be a polymer having an alicyclic structure in the main chain, a polymer having an alicyclic structure in the side chain, a polymer having an alicyclic structure in the main chain and the side chain, or a mixture of two or more of them in any ratio. Among them, a polymer having an alicyclic structure in the main chain is preferable from the viewpoints of mechanical strength and heat resistance.

Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene) structure. Among them, from the viewpoints of mechanical strength and heat resistance, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.

The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, still more preferably 30 or less, still more preferably 20 or less, and particularly preferably 15 or less, per alicyclic structure. When the number of carbon atoms constituting the alicyclic structure is within this range, the mechanical strength, heat resistance and moldability of the resin are highly balanced.

The proportion of the structural unit having an alicyclic structure in the cyclic olefin polymer is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the proportion of the structural unit having an alicyclic structure in the cyclic olefin polymer falls within this range, the transparency and heat resistance are good.

Examples of the cyclic olefin polymer include norbornene polymers, monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof. Among these, norbornene polymers and hydrides thereof are particularly preferable because of their good moldability.

Examples of the norbornene polymer and its hydrogenated product include a ring-opened polymer of a monomer having a norbornyl structure and its hydrogenated product, and an addition polymer of a monomer having a norbornyl structure and its hydrogenated product. Examples of the ring-opening polymer of the monomer having a norbornene structure include a ring-opening homopolymer of one monomer having a norbornene structure, a ring-opening copolymer of two or more monomers having a norbornene structure, and a ring-opening copolymer of a monomer having a norbornene structure and another monomer copolymerizable therewith. Further, examples of the addition polymer of the monomer having a norbornyl structure include an addition homopolymer of one monomer having a norbornyl structure, an addition copolymer of two or more monomers having a norbornyl structure, and an addition copolymer of a monomer having a norbornyl structure and another monomer copolymerizable therewith. Among these, from the viewpoints of moldability, heat resistance, low hygroscopicity, dimensional stability, light weight and the like, a hydrogenated product of a ring-opening polymer of a monomer having a norbornene structure is particularly preferable.

The weight average molecular weight (Mw) of the cyclic olefin polymer is preferably 10000 or more, more preferably 15000 or more, particularly preferably 20000 or more, preferably 100000 or less, more preferably 80000 or less, particularly preferably 50000 or less. When the weight average molecular weight is within the above range, the mechanical strength and molding processability of the resin are highly balanced.

The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the cyclic olefin polymer is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 3.5 or less, more preferably 3.0 or less, particularly preferably 2.7 or less. When the molecular weight distribution is equal to or more than the lower limit of the above range, the productivity of the polymer can be improved, and the production cost can be suppressed. In addition, when the molecular weight distribution is equal to or less than the upper limit value, the amount of the low-molecular component becomes small, so that relaxation at the time of high-temperature exposure can be suppressed, and the stability of the film can be improved.

The weight average molecular weight and the number average molecular weight are the weight average molecular weights in terms of polyisoprene or polystyrene measured using cyclohexane as a solvent and gel permeation chromatography. However, in the above gel permeation chromatography, toluene may be used as a solvent in the case where the sample is not dissolved in cyclohexane.

The glass transition temperature of the cyclic olefin polymer is preferably 130 ℃ or higher, more preferably 135 ℃ or higher, preferably 150 ℃ or lower, more preferably 145 ℃ or lower. When the glass transition temperature is equal to or higher than the lower limit of the above range, the durability of the film at high temperature can be improved. In addition, when the glass transition temperature is equal to or lower than the upper limit of the above range, the stretching treatment can be easily performed.

As the cyclic olefin polymer, for example, a cyclic olefin polymer described in international publication No. 2017/145718 can be used.

The proportion of the cyclic olefin polymer in the cyclic olefin resin is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, and particularly preferably 90 to 100% by weight. In the case where the proportion of the polymer is within the above range, sufficient heat resistance and transparency can be obtained.

The cyclic olefin resin can include any component other than the cyclic olefin polymer as long as the effect of the present invention is not significantly impaired. Examples of the optional component include a colorant such as a pigment or a dye, a fluorescent whitening agent, a dispersant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antistatic agent, an antioxidant, a slip agent, and the like. Further, one kind of these may be used alone, or two or more kinds may be used in combination in any ratio.

The (meth) acrylic resin is a resin containing a (meth) acrylic polymer. The (meth) acrylic polymer refers to a polymer of acrylic acid or an acrylic acid derivative, and examples thereof include polymers and copolymers of acrylic acid, acrylic acid esters, acrylamide, acrylonitrile, methacrylic acid, and methacrylic acid esters. The (meth) acrylic polymer has high strength and is hard, and thus a film having high mechanical strength can be realized.

The (meth) acrylic polymer is preferably a polymer containing a structural unit having a structure obtained by polymerizing a (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include alkyl esters of (meth) acrylic acid. Among them, a compound having a structure derived from (meth) acrylic acid and an alkanol or cycloalkanol having 1 to 15 carbon atoms is preferable. Further, a compound having a structure derived from (meth) acrylic acid and an alkanol having 1 to 8 carbon atoms is more preferable. By reducing the number of carbon atoms as described above, elongation at break of the film can be reduced.

Specific examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, t-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate, and the like.

Specific examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, and n-dodecyl methacrylate.

Further, the (meth) acrylic acid ester may have a substituent such as a hydroxyl group or a halogen atom as long as the effect of the present invention is not significantly impaired. Examples of the (meth) acrylic acid ester having such a substituent include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, and glycidyl methacrylate. These may be used alone or in combination of two or more at any ratio.

The (meth) acrylic acid polymer may be a polymer of only acrylic acid or an acrylic acid derivative, or may be a copolymer of acrylic acid or an acrylic acid derivative and any monomer copolymerizable therewith. Examples of the optional monomer include an α, β -ethylenically unsaturated carboxylic acid ester monomer other than the above (meth) acrylic acid ester, an α, β -ethylenically unsaturated carboxylic acid monomer, an alkenyl aromatic monomer, a conjugated diene monomer, a non-conjugated diene monomer, an unsaturated alcohol carboxylic acid ester, and an olefin monomer. These may be used alone or in combination of two or more at any ratio.

When the (meth) acrylic polymer contains an optional monomer, the amount of the structural unit having a structure obtained by polymerizing the optional monomer in the (meth) acrylic polymer is preferably 50% by weight or less, more preferably 15% by weight or less, and particularly preferably 10% by weight or less.

Among these (meth) acrylic polymers, polymethacrylates are preferable, and among them, polymethyl methacrylate is more preferable.

As the (meth) acrylic polymer, for example, a (meth) acrylic polymer described in international publication No. 2017/145718 can be used.

The proportion of the (meth) acrylic polymer in the (meth) acrylic resin is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, and particularly preferably 90 to 100% by weight. In the case where the proportion of the polymer is within the above range, sufficient heat resistance and transparency can be obtained.

The (meth) acrylic resin can include any component other than the (meth) acrylic polymer as long as the effect of the present invention is not significantly impaired. When any component is exemplified, for example, the same component as any component that can be contained in the cyclic olefin resin can be exemplified. Further, any one of the components may be used alone, or two or more of the components may be used in combination in any ratio.

The base material layer can be produced by molding a resin by an appropriate film molding method. Examples of the film forming method include a casting forming method, an extrusion forming method, and an inflation forming method. Among them, the melt extrusion method using no solvent is preferable from the viewpoints of effectively reducing the amount of residual volatile components, environmental protection, and working environment, and excellent production efficiency. As the melt extrusion method, a blow-up method using a die can be used, and a T-die method is preferable in terms of excellent productivity and thickness accuracy.

In the case of using a multilayer film having 2 or more layers as the long film, the multilayer film preferably has a base material layer and a functional layer. The functional layer may be provided on one side or both sides of the base material layer. Among them, the functional layer is preferably provided on the knurled portion side of the base material layer, and further preferably, the knurled portion is provided on the surface of the functional layer.

Examples of such functional layers include an antistatic layer, a hard coat layer, an anti-sticking layer, and an easy-to-adhere layer.

The antistatic layer refers to a layer having a small surface resistance value. The specific surface resistance value of the antistatic layer is preferably 1.0x ⁶ Ω/≡or more, more preferably 1.0x ⁷ Ω/≡or more, particularly preferably 1.0x ⁸ Ω/≡preferably 1.0x ¹⁰ Ω/≡or less, more preferably 5.0x ⁹ Ω/≡or less, particularly preferably 1.0x ⁹ Ω/≡or less. The surface resistance value can be measured according to JIS K6911 using a digital super insulating/micro ammeter (DSM-8104, manufactured by Nippon electric Co., ltd.). Such an antistatic layer can be formed, for example, by a resin containing conductive particles such as metal oxide particles and a polymer.

The hard coat layer means a layer having high hardness. When the specific hardness of the hard coat layer is represented by JIS pencil hardness, it is preferably B or more, more preferably HB or more, particularly preferably H or more. Here, the JIS pencil hardness is a pencil hardness at which the pencil of various hardness is inclined by 45 ° according to JIS K5600-5-4, and a load of 500g weight is applied from above to scratch the surface of the layer to start damage. Such a hard coat layer can be formed by, for example, a resin.

The anti-adhesion layer refers to a layer having a rough surface and capable of inhibiting adhesion between films when overlapped with other films. Such an anti-adhesion layer can be formed, for example, by a resin containing a polymer and particles.

The easy-to-adhere layer is a layer that exhibits high adhesion when the surface of the easy-to-adhere layer is bonded to another member. Such an easy-to-adhere layer can be formed by, for example, a resin containing a polymer.

Among the functional layers, an easy-to-adhere layer is preferable. The easy-to-adhere layer is preferably a layer containing an aqueous resin. The aqueous resin is a resin that can be prepared in the form of a solution or dispersion using water as a medium. The aqueous resin layer can be formed on the surface of the base material layer by applying an aqueous solution or aqueous dispersion containing the aqueous resin to the surface of the base material layer and drying the aqueous solution or aqueous dispersion. Examples of the aqueous resin include polyurethane resin, polyester resin, and emulsion of each resin, and preferably aqueous polyurethane resin.

As the functional layer, for example, a functional layer described in international publication No. 2017/145718 can be used.

[5 Use of elongated film ]

The elongated film can be used for a wide variety of applications, and is particularly preferably used as an optical film. Examples of the optical film include a retardation film, a polarizing plate protective film, and an optical compensation film. Among them, the long film is preferably used as a polarizer protective film.

The polarizer generally has a polarizer and a polarizer protective film. Therefore, when the long film is used as a polarizer protective film, the long film is usually bonded to a polarizer.

In the case of bonding the long film and the polarizer, the long film and the polarizer may be bonded directly without an adhesive, or may be bonded via an adhesive. Further, the long film may be bonded to only one side of the polarizer, or may be bonded to both sides. When a long film is bonded to only one surface of the polarizer, another film having high transparency may be bonded to the other surface of the polarizer.

As the polarizer, for example, a film produced by adsorbing iodine or a dichroic dye to a polyvinyl alcohol film and then uniaxially stretching the film in a boric acid bath can be used. As the polarizer, for example, a film produced by allowing a polyvinyl alcohol film to adsorb iodine or a dichroic dye, stretching the film, and further modifying a part of polyvinyl alcohol units in a molecular chain into polyvinyl units can be used. Further, as the polarizer, for example, a grid polarizer, a multilayer polarizer, a cholesteric liquid crystal layer polarizer, or the like having a function of separating polarized light into reflected light and transmitted light can be used. Among these, a polarizer containing polyvinyl alcohol is preferable. The degree of polarization of the polarizer is preferably 98% or more, more preferably 99% or more. The average thickness of the polarizer is preferably 5 μm to 80 μm.

As an adhesive for bonding the long film and the polarizer, an optically transparent adhesive can be used. Examples of the adhesive include an aqueous adhesive, a solvent-based adhesive, a two-component curing adhesive, a photo-curing adhesive, and a pressure-sensitive adhesive. Among these, aqueous adhesives and photocurable adhesives are preferable, and particularly, polyvinyl alcohol-based aqueous adhesives are preferable. As the adhesive, for example, an adhesive described in international publication No. 2017/145718 can be used. The binder may be used alone or in combination of two or more kinds in any ratio.

In the case where the polarizer and the long film are bonded using an adhesive, the adhesive may be cured as needed after the polarizer and the long film are bonded via the adhesive. The method of curing the adhesive may be an appropriate method depending on the type of adhesive. For example, in the case of using a photocurable adhesive, the adhesive can be cured by irradiation with active energy rays such as ultraviolet rays.

In the case of using an adhesive, an adhesive layer is provided between the polarizer and the long film. The adhesive layer preferably has an average thickness of 0.05 μm or more, more preferably 0.1 μm or more, preferably 5 μm or less, more preferably 1 μm or less.

Examples

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the embodiments described below, and can be arbitrarily modified without departing from the scope of the patent claims and equivalents thereof. In the following description, "%" and "parts" representing amounts are weight standards unless otherwise specified. The operation described below is performed in the atmosphere at normal temperature and normal pressure unless otherwise described.

[ Evaluation method ]

[ Method for measuring the height of concave-convex portion ]

The height of the concave-convex portion of the knurled portion of the long film is measured using, for example, a three-dimensional surface profiler (NewView 5000, manufactured by ZYGO corporation).

[ Method for measuring radius of curvature of corner ]

The radius of curvature of the corner of the knurled portion of the elongated film was measured using, for example, a three-dimensional surface profiler (NewView 5000, manufactured by ZYGO corporation).

Example 1

[ Production of substrate layer ]

Pellets of a cyclic olefin resin (ZEONOR, manufactured by Japanese Rayleigh Weng Zhushi Co., ltd.) were dried at 70℃for 2 hours using a hot air dryer through which air was circulated. The dried pellets are supplied to a device having a deviceA T-mode film melt extrusion molding machine of a screw of the above-described resin melt kneader was extrusion-molded under a molding condition of a mold having a melt resin temperature of 270℃, T and a width of 1700mm, to produce a long base material layer (thickness: 50 μm, width: 1500mm, length: 4000 m).

[ Production of film before treatment (formation of adhesive layer) ]

An aqueous dispersion of polyether polyurethane (manufactured by first industry pharmaceutical Co., ltd. "superflex 870") was blended with 15 parts of an epoxy compound (manufactured by Daikagaku ChemteX Co., ltd. "DENACOL EX") as a crosslinking agent, 8 parts of an aqueous dispersion of silica particles as a slip material (manufactured by Nissan chemical Co., ltd. "snowtexMP1040"; average particle diameter 120 nm) and 8 parts of an aqueous dispersion of silica particles (manufactured by Nissan chemical Co., ltd. "snowtexXL"; average particle diameter 50 nm) were mixed with water, and an acetylene surfactant (manufactured by air chemical Co., ltd. "SURFYNOL 440") as a wetting agent was added in an amount of 0.5% by weight based on the total solid content, to obtain an aqueous dispersion of a liquid polyurethane resin having a solid content of 2%.

The aqueous polyurethane resin dispersion was applied to one side of the base layer by a reverse roll method so that the thickness after drying was 45nm, and dried at 90 ℃. Thus, an easy-to-adhere layer is formed on one side of the base material layer, and a pre-treatment film having a multilayer structure of the base material layer and the easy-to-adhere layer is obtained.

[ Formation of knurled portion ]

The pre-treatment film was transported in the longitudinal direction at a speed of 30 m/min. Then, laser light is irradiated to the surfaces of the adhesive layer side at the left and right ends in the width direction of the conveyed pre-treatment film to form a plurality of knurled portions, thereby obtaining a long film. As the laser irradiation apparatus, a CO ₂ laser irradiation apparatus (manufactured by COHERENT Co., ltd. "J3 series", laser wavelength 9.4 μm) was used. The irradiation power of the laser was set to 50%. Further, the laser irradiation was performed while moving the laser irradiation point at a movement speed of 7000mm/s by scanning the galvanometer so as to draw the planar shape of the desired knurled portion.

Fig. 20 and 21 are schematic plan views showing the planar shape of the knurled section 1000 formed in embodiment 1 of the present invention.

By the irradiation of the laser beam, a knurled portion 1000 having a planar shape shown in fig. 20 and 21 is formed from the uneven portion having a width W of 0.2 mm. The knurled portion 1000 has a ring shape including a first wire group portion 1100, a second wire group portion 1200, a first connection portion 1300, and a second connection portion 1400, which are connected to each other.

The first string part 1100 has a saw tooth shape including a plurality of continuous straight line parts. Specifically, the first wire set 1100 has a straight portion 1111 extending from the first position 1101 to the corner 1131, a straight portion 1112 extending from the corner 1131 to the corner 1132, a straight portion 1113 extending from the corner 1132 to the corner 1133, a straight portion 1114 extending from the corner 1133 to the corner 1134, a straight portion 1115 extending from the corner 1134 to the corner 1135, a straight portion 1116 extending from the corner 1135 to the corner 1136, a straight portion 1117 extending from the corner 1136 to the corner 1137, a straight portion 1118 extending from the corner 1137 to the corner 1138 (corresponding to the second position), a straight portion 1119 extending from the corner 1138 to the corner 1139, a straight portion 1120 extending from the corner 1139 to the corner 1140, a straight portion 1121 extending from the corner 1140 to the corner 1141, and a straight portion 1122 extending from the corner 1141 to the corner 1142.

The second line group portion 1200 has a zigzag shape including a plurality of continuous straight line portions. Specifically, the second wire set 1200 has a straight portion 1211 extending from the third position 1201 to the corner 1231, a straight portion 1212 extending from the corner 1231 to the corner 1232, a straight portion 1213 extending from the corner 1232 to the corner 1233, a straight portion 1214 extending from the corner 1233 to the corner 1234, a straight portion 1215 extending from the corner 1234 to the corner 1235, a straight portion 1216 extending from the corner 1235 to the corner 1236, a straight portion 1217 extending from the corner 1236 to the corner 1237, a straight portion 1211218 extending from the corner 1237 to the corner 1238 (corresponding to the fourth position), a straight portion 1220 extending from the corner 1238 to the corner 1239, a straight portion 1221 extending from the corner 1240 to the corner 1241, and a straight portion 1222 extending from the corner 1241 to the corner 1242.

The first connection portion 1300 is formed parallel to the straight portion 1111 as a straight line connecting the first position 1101 of the first wire group portion 1100 and the corner portion 1242 of the second wire group portion 1200.

The second connection portion 1400 is formed parallel to the straight portion 1211 as a straight line connecting the corner portion 1142 of the first line group portion 1100 and the third position 1201 of the second line group portion 1200.

The straight portions 1111 to 1122 included in the first string part 1100 and the straight portions 1211 to 1222 included in the second string part 1200 are straight lines having the same length (1.1 mm).

All the corners 1131-1142 and 1231-1242 included in the knurled portion 1000 have an angle of 90 °. The radii of curvature of all the corners 1131 to 1142 and 1231 to 1242 included in the knurled portion 1000 are 0.2mm. Furthermore, the corners 1131 to 1142 and 1231 to 1242 are each provided at different positions with a fixed distance d=0.4 mm therebetween in the width direction. The difference in the distance D between the corners was 0.05mm.

The length L _MD of the knurled portion 1000 in the film longitudinal direction MD was 1.9mm, and the length L _TD of the knurled portion 1000 in the film width direction TD was 9.4mm. Further, the pitch of the knurled sections 1000 in the film longitudinal direction MD was 4.2mm.

Further, the height of the uneven portion forming the knurled portion 1000 was measured, and as a result, the average height of the corner portion was 7 μm.

[ Evaluation of the precision of knurled portion formation ]

Positions of the corners 1131 to 1142, 1231 to 1242 of the knurled portion 1000 are measured. As a result, the following matters were confirmed.

Corners 1132, 1134, 1136, 1138, 1140, and 1142 of the first wire set 1100 are at positions that can be on a virtual straight line 140 having a thickness of 0.1mm passing through the first position 1101 and the corner 1138. Further, the virtual straight line 140 is parallel to the film width direction TD.

Corners 1232, 1234, 1236, 1238, 1240, and 1242 of the second wire set 1200 are in positions that can be on a virtual straight line 240 having a thickness of 0.1mm passing through the third position 1201 and the corner 1238. Further, the virtual straight line 240 is parallel to the film width direction TD.

The corner 1131 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting the first position 1101 and the corner 1132.

The corner 1133 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 1132 and the corner 1134.

The corner 1135 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 1134 and the corner 1136.

The corner 1137 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 1136 and the corner 1138.

Corner 1139 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 1138 and corner 1140.

Corner 1141 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 1140 and corner 1142.

The corner 1231 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting the third position 1201 and the corner 1232.

Corner 1233 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 1232 and corner 1234.

Corner 1235 can be located on a virtual circle (a circle depicted by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 1234 and corner 1236.

The corner 1237 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 1236 and the corner 1238.

Corner 1239 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting corner 1238 and corner 1240.

Corner 1241 is located at a position on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter which is a virtual line segment connecting corner 1240 and corner 1242.

In this case, the diameters of the virtual circles are all the same length.

[ Evaluation of winding Property ]

The long film having the knurled portion formed as described above was further conveyed in the longitudinal direction, and wound in the longitudinal direction by 4000m with a winding tension 120N around a core (core) having a diameter of 6 inches, to obtain a film roll. The resulting film roll was observed, and the windability of the long film was evaluated.

Example 2

A pre-treatment film was produced by the same method as in example 1. The surfaces of the left and right ends of the film before the treatment on the side of the easy-to-adhere layer were irradiated with laser light under the same conditions as in example 1 to form a plurality of knurled portions, thereby obtaining a long film.

Fig. 22 and 23 are schematic plan views showing the planar shape of the knurled section 2000 formed in embodiment 2 of the present invention.

By the irradiation of the laser beam, a knurled portion 2000 having a planar shape shown in fig. 22 and 23 is formed from the uneven portion having a width W of 0.2 mm. The knurled portion 2000 has a ring shape including a first wire group portion 2100, a second wire group portion 2200, a first connection portion 2300, and a second connection portion 2400, which are connected to each other.

The first string part 2100 has a saw tooth shape including a plurality of continuous straight line parts. Specifically, the first line group portion 2100 has a straight line portion 2111 extending from the corner portion 2131 (corresponding to the first position) to the corner portion 2132, a straight line portion 2112 extending from the corner portion 2132 to the corner portion 2133, a straight line portion 2113 extending from the corner portion 2133 to the corner portion 2134, a straight line portion 2114 extending from the corner portion 2134 to the corner portion 2135, a straight line portion 2115 extending from the corner portion 2135 to the corner portion 2136, a straight line portion 2116 extending from the corner portion 2136 to the corner portion 2137, a straight line portion 2117 extending from the corner portion 2137 to the corner portion 2138, a straight line portion 2118 extending from the corner portion 2138 to the corner portion 2139 (corresponding to the second position), a straight line portion 2119 extending from the corner portion 2139 to the corner portion 2141, a straight line portion 2120 extending from the corner portion 2141 to the corner portion 2142, a straight line portion 2141 extending from the corner portion 2142 to the corner portion 2143, a straight line portion 2122 extending from the corner portion 2143 to the corner portion 2123, a straight line portion 2124 to the corner portion 2144, and a straight line portion 2145.

The second line group portion 2200 has a zigzag shape including a plurality of continuous straight line portions. Specifically, the second line group portion 2200 has a straight line portion 2211 extending from the corner portion 2231 (corresponding to the third position) to the corner portion 2232, a straight line portion 2212 extending from the corner portion 2232 to the corner portion 2233, a straight line portion 2213 extending from the corner portion 2233 to the corner portion 2234, a straight line portion 2214 extending from the corner portion 2234 to the corner portion 2235, a straight line portion 2215 extending from the corner portion 2235 to the corner portion 2236, a straight line portion 2216 extending from the corner portion 2236 to the corner portion 2237, a straight line portion 2217 extending from the corner portion 2237 to the corner portion 2238, a straight line portion 2218 extending from the corner portion 2238 to the corner portion 2239 (corresponding to the fourth position), a straight line portion 2219 extending from the corner portion 2239 to the corner portion 2240, a straight line portion 2220 extending from the corner portion 2240 to the corner portion 2241, a straight line portion 2221 extending from the corner portion 2242 to the corner portion 2243, a straight line portion 2 extending from the corner portion 2242 to the corner portion 2243, a straight line portion 2244 extending from the corner portion 2244 to the corner portion 2244.

The first connection portion 2300 has a straight line portion 2311 extending from the corner portion 2131 of the first wire set portion 2100 to the corner portion 2331, and a straight line portion 2312 extending from the corner portion 2331 to the corner portion 2245 of the second wire set portion 2200.

The second connection portion 2400 has a straight portion 2411 extending from the corner 2145 of the first wire set portion 2100 to the corner 2431, and a straight portion 2412 extending from the corner 2431 to the corner 2231 of the second wire set portion 2200.

The straight portions 2111, 2113, 2115, 2117, 2119, 2121 and 2123 included in the first line group portion 2100 and the straight portions 2211, 2213, 2215, 2217, 2219, 2221 and 2223 included in the second line group portion 2200 are straight lines having the same length (1.0 mm).

Further, the straight portions 2112, 2114, 2116, 2118, 2120, 2122, and 2124 included in the first line group portion 2100 and the straight portions 2212, 2214, 2216, 2218, 2220, 2222, and 2224 included in the second line group portion 2200 are straight lines having the same length (0.6 mm).

All the corners 2131 to 2145, 2231 to 2245, 2331 and 2431 included in the knurled portion 2000 have an angle of 90 °. The radii of curvature of all the corners 2131 to 2145, 2231 to 2245, 2331, and 2431 included in the knurled portion 2000 are 0.2mm. Further, the corners 2131 to 2145, 2231 to 2245, 2331 and 2431 are each provided at different positions with a fixed distance d=0.3 mm therebetween in the width direction. The difference in the distance D between the corners was 0.05mm.

The length L _MD of the knurled portion 2000 in the film length direction MD was 1.2mm, and the length L _TD of the knurled portion 2000 in the film thickness direction TD was 9.5mm. Further, the pitch of the knurled portions 2000 in the film longitudinal direction MD was 4.2mm.

Further, the height of the concave-convex portions forming the knurled portion 2000 was measured, and as a result, the average height of the corner portions was 7 μm.

[ Evaluation of the precision of knurled portion formation ]

Positions of corners 2131 to 2145 and 2231 to 2245 of the knurled portion 2000 are measured. As a result, the following matters were confirmed.

Corners 2131, 2133, 2135, 2137, 2139, 2141, 2143, and 2145 of the first wire set 2100 are located on a virtual straight line 140 having a thickness of 0.1mm passing through the corners 2131 and 2139. Further, the virtual straight line 140 is parallel to the film width direction TD.

Corners 2231, 2233, 2235, 2237, 2239, 2241, 2243, and 2245 of the second wire group portion 2200 can be positioned on the virtual straight line 140 having a thickness of 0.1mm passing through the corners 2231 and 2239. Further, the virtual straight line 240 is parallel to the film width direction TD.

The corner 2132 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 2131 and the corner 2133.

Corner 2134 may be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting corner 2133 and corner 2135.

Corner 2136 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting corner 2135 and corner 2137.

Corner 2138 may be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting corner 2137 and corner 2139.

Corner 2140 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 2139 and corner 2141.

The corner 2142 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 2141 and the corner 2143.

The corner 2144 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 2143 and the corner 2145.

Corner 2232 can be located on a virtual circle (a circle depicted by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 2231 and corner 2233.

Corner 2234 can be located on a virtual circle (a circle depicted by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 2233 and corner 2235.

Corner 2236 can be located on a virtual circle (a circle depicted by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 2235 and corner 2237.

Corner 2238 can be located on a virtual circle (a circle depicted by a line having a thickness of 0.1 mm) having a diameter that is a virtual line segment connecting corner 2237 and corner 2239.

Corner 2240 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting corner 2239 and corner 2241.

The corner 2242 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 2241 and the corner 2243.

The corner 2244 can be located on a virtual circle (a circle drawn by a line having a thickness of 0.1 mm) having a diameter of a virtual line segment connecting the corner 2243 and the corner 2245.

In this case, the diameters of the virtual circles are all the same length.

[ Evaluation of winding Property ]

The long film having the knurled portion formed as described above was further conveyed in the longitudinal direction, and wound in the longitudinal direction by 4000m with a winding tension 120N around a core (core) having a diameter of 6 inches, to obtain a film roll. The resulting film roll was observed, and the windability of the long film was evaluated.

Comparative example 1

Fig. 24 is a schematic plan view showing the planar shape of the knurled portion 3000 formed in comparative example 1.

As shown in fig. 24, the production and evaluation of the long film and the film roll were performed by the same method as in example 1 except that the planar shape of the knurled portion 3000 was changed to the same shape as in example 1 of international publication No. 2017/145718. As shown in fig. 24, in the knurled portion 3000 formed, the positions of the corner portions 3010 of some portions are the same in the film width direction TD.

In the knurled portion 3000 formed in comparative example 1, the angle of the corner indicated by reference numeral 3010 in fig. 24 was 90 °, the angle of the corner indicated by reference numeral 3020 was 135 °, the length L _MD of the knurled portion 3000 in the film length direction MD was 1.2mm, the length L _TD of the knurled portion 3000 in the film width direction TD was 9.3mm, and the pitch of the knurled portion 3000 in the film length direction MD was 4.2mm. Further, the height of the uneven portion forming the knurled portion 3000 was measured, and as a result, the average height of the corner portion was 7 μm.

Comparative example 2

The production and evaluation of the long film and the film roll were performed in the same manner as in comparative example 1 except that the irradiation power of the laser light for forming the knurled portion was changed to 60% and the winding tension at the time of winding the long film was changed to 150N. The knurled portion formed in comparative example 2 had the same planar shape as comparative example 1, but the average height of the corner portions of the concave-convex portion forming the knurled portion was 12 μm.

Results (results)

The results of examples and comparative examples are shown in the following table.

TABLE 1

TABLE 1 results of examples and comparative examples

	Adhesion to	Wound appearance	Roll offset	Unevenness (buckling)
					Example 1	Without any means for	Good quality	Without any means for	Without any means for
Example 2	Without any means for	Good quality	Without any means for	Without any means for
					Comparative example 1	Without any means for	Failure of	Partial generation of	Partial generation of
Comparative example 2	Partial generation of	Good quality	Without any means for	Without any means for

Description of the reference numerals

1 Strip film

1U surface of strip film

10 Knurled part

20 Concave-convex part

21 Concave part

22 Convex part

30 Knurling part

40 Knurled portion

50 Knurled portion

100 First wire group part

111 First straight line portion

112 A second straight line portion

113 Third straight line portion

114 Fourth straight line portion

115 Fifth straight line portion

116 Sixth straight line portion

117 Seventh straight line portion

118 Eighth straight line portion

121 First position

122 Second position

131 First corner

132 Second corner portion

133 Third corner

134 Fourth corner

135 Fifth corner

136 Sixth corner portion

137 Seventh corner part

140 First virtual straight line

141 First virtual line segment

142 Second virtual line segment

143 Third virtual line segment

144 Fourth virtual line segment

151 First virtual circle

152 Second virtual circle

153 Third virtual circle

154 Fourth virtual circle

200 Second line group part

211 Ninth straight line portion

212 Tenth straight line portion

213 Eleventh straight line portion

214 Twelfth straight line portion

215 Thirteenth straight line portion

216 Fourteenth straight line portion

217 Fifteenth straight line portion

218 Sixteenth straight line portion

221 Third position

222 Fourth position

231 Eighth corner

232 Ninth corner portion

233 Tenth corner

234 Eleventh corner portion

235 Twelfth corner

236 Thirteenth corner

237 Fourteenth corner

240 Second virtual straight line

241 Fifth virtual line segment

242 Sixth virtual line segment

243 Seventh virtual line segment

244 Eighth virtual line segment

251 Fifth virtual circle

252 Sixth virtual circle

253 Seventh virtual circle

254 Eighth virtual circle

300 First connecting portion

311. 312 And 313 line segment

331 And 332 corner portions

400 Second connecting portion

411. 412 And 413 line segment

431 And 432 corner portions

500 First wire set

511 First straight line portion

512 Second straight line portion

513 Third straight line portion

514 Fourth straight line portion

515 Fifth straight line portion

516 Sixth straight line portion

517 Seventh straight line portion

518 Eighth straight line portion

600 Second line group part

611 Ninth straight line portion

612 Tenth straight line portion

613 Eleventh straight line portion

614 Twelfth straight line part

615 Thirteenth straight line part

616 Fourteenth straight line portion

617 Fifteenth straight line portion

618 Sixteenth straight line portion

700 First connecting portion

800 Second connecting portion

Claims (7)

1. A long film having a plurality of knurled sections formed of continuous linear concave-convex sections on at least one surface, wherein,

The planar shape of the knurled section as viewed from the thickness direction of the elongated film includes a first wire group section and a second wire group section,

The first string part includes:

A first straight line part extending from the first position to the first corner part in a straight line,

A second straight line portion extending linearly from the first corner portion to the second corner portion,

A third linear portion extending linearly from the second corner portion to the third corner portion,

A fourth linear portion extending linearly from the third corner portion to the fourth corner portion,

A fifth linear portion extending linearly from the fourth corner portion to the fifth corner portion,

A sixth linear portion extending linearly from the fifth corner portion to the sixth corner portion,

A seventh straight line portion extending straight from the sixth corner portion to the seventh corner portion, and

An eighth linear portion extending linearly from the seventh corner portion to the second position,

The second wire set portion includes:

a ninth linear portion extending linearly from the third position to the eighth position,

A tenth linear portion extending linearly from the eighth corner portion to the ninth corner portion,

An eleventh linear portion extending linearly from the ninth corner portion to the tenth corner portion,

A twelfth linear part extending linearly from the tenth corner to the tenth corner,

A thirteenth linear portion extending linearly from the tenth corner portion to the twelfth corner portion,

A fourteenth linear portion extending linearly from the twelfth corner portion to the tenth corner portion,

A fifteenth linear portion extending linearly from the tenth triangular portion to the tenth corner portion, and

A sixteenth linear portion extending linearly from the tenth corner portion to a fourth position,

The first string part and the second string part are formed at different positions in the length direction of the long film,

The first to fourteenth corners each independently have an angle of 80 DEG to 100 DEG,

The positions of the corner portions are different in the width direction of the long film.

2. The strip film of claim 1 wherein,

The variation in the interval between the corners in the width direction of the long film is 1.00mm or less.

3. The elongated film according to claim 1 or 2, wherein,

In the case where a first virtual straight line passing through the first position and the second position is depicted with a line 3 times thicker than the width of the concave-convex portion, the second corner portion, the fourth corner portion, and the sixth corner portion are on the first virtual straight line,

In the case where a second virtual straight line passing through the third position and the fourth position is drawn with a line 3 times thicker than the width of the concave-convex portion, the ninth corner, the eleventh corner, and the tenth corner are on the second virtual straight line.

4. The elongated film according to claim 1 or 2, wherein,

In the case where a first virtual circle having a diameter of a first virtual line segment connecting the first position and the second corner is depicted by a line 3 times thicker than the width of the concave-convex portion, the first corner is on the first virtual circle,

In the case where a second virtual circle having a diameter of a second virtual line segment connecting the second corner and the fourth corner is drawn with a line 3 times the width of the concave-convex portion, the third corner is located on the second virtual circle,

In the case where a third virtual circle having a diameter of a third virtual line segment connecting the fourth corner and the sixth corner is drawn with a line 3 times the width of the concave-convex portion, the fifth corner is located on the third virtual circle,

In the case where a fourth virtual circle having a diameter of a fourth virtual line segment connecting the sixth corner and the second position is depicted with a line 3 times thicker than the width of the concave-convex portion, the seventh corner is on the fourth virtual circle,

In the case where a fifth virtual circle having a diameter of a fifth virtual line segment connecting the third position and the ninth corner is drawn with a line 3 times the width of the concave-convex portion, the eighth corner is located on the fifth virtual circle,

In the case where a sixth virtual circle having a diameter of a sixth virtual line segment connecting the ninth corner and the tenth corner is drawn with a line 3 times thicker than the width of the concave-convex portion, the tenth corner is on the sixth virtual circle,

In the case where a seventh virtual circle having a diameter of a seventh virtual line segment connecting the tenth corner and the tenth corner is drawn with a line 3 times thicker than the width of the concave-convex portion, the twelfth corner is on the seventh virtual circle,

In the case where an eighth virtual circle having a diameter of an eighth virtual line segment connecting the tenth triangle portion and the fourth position is drawn with a line 3 times thicker than the width of the concave-convex portion, the fourteenth corner portion is located on the eighth virtual circle.

5. The strip film of claim 4 wherein,

The diameters from the first virtual circle to the eighth virtual circle are equal.

6. The elongated film according to claim 1 or 2, wherein,

The first wire set portion is disjoint from the second wire set portion.

7. The elongated film according to claim 1 or 2, wherein,

The long film has a base layer formed of a cyclic olefin resin or a (meth) acrylic resin.