JP5277458B2 - Optical film and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical film and a method for producing the same.

  When an optical film is wound into a roll, it is widely known that an embossed (nar) region is formed at an end in the width direction. The embossed area serves as an anti-slip to prevent the film from being misaligned during winding. For example, in the technique of Patent Document 1, embossing is applied in a certain area to suppress winding deviation and tape transfer trace.

  However, with the progress of production speed and widening, there has been a new problem that the film is wrinkled and broken due to the entrainment air at the time of film winding. When air was caught at the time of winding the film, the air was removed over time, so that the films were stuck or loosened. Furthermore, wrinkles and creases occurred in the slack portion of the film. In order to solve such a problem, attempts have been made to change the winding condition, but it has not been possible to sufficiently suppress sticking, loosening, wrinkling, and folding between films.

  Therefore, Patent Document 2 reports a technique for suppressing air entrainment by pressing the film against the film roll with a rubber roll when the film is wound. However, with such a technique, generation of air could be suppressed, but sticking between films increased.

In the conventionally known emboss shape, the distance in the conveyance direction between the convex area units is substantially equal to or greater than the length in the conveyance direction of the convex area units in a vertical cross section with respect to the width direction.
JP 2007-70514 A JP 2006-193327 A

  However, since the conventional technique relates to a technique for preventing air from being involved when winding the film, it has not been possible to sufficiently suppress sticking between films, winding looseness, wrinkles, and folding.

  The present invention relates to a technology that does not release air trapped during film winding, thereby sufficiently suppressing the occurrence of sticking, loose winding, wrinkles and breakage between films while suppressing winding deviation. An object of the present invention is to provide an optical film and a method for producing the same.

The present invention has embossed regions at both ends in the width direction of the polymer film, and in each embossed region, one or more convex rows are formed in which the convex regions are formed intermittently or continuously substantially parallel to the transport direction. An optical film comprising:
The embossed regions at both ends independently have an area ratio of a convex region of 20 to 80%, and satisfy the following requirements (I) or (II);
(I) The embossed region has only two or more intermittent convex rows formed by intermittently forming convex regions in the transport direction, and between any two convex region units adjacent in the transport direction in each convex row Concerning the conveyance direction distance x (mm) is 0.4 or less with respect to the conveyance direction length y (mm) of the convex region unit, one convex row is in any two convex rows adjacent in the width direction. In the vertical cross-sectional perspective view with respect to the width direction, any one convex area unit in FIG. 2 overlaps with two convex area units adjacent in the transport direction in the other convex row on the upstream and downstream sides in the transport direction, and in the transport direction. The smaller one of the conveyance direction length z1 (mm) of the overlapping portion on the upstream side and the conveyance direction length z2 (mm) of the overlapping portion on the downstream side in the conveyance direction is the conveyance direction length y (mm) of the convex region unit. ) Is 0.3 or more ;
(II) The embossed region has one or more continuous convex rows formed by continuously forming convex regions in the transport direction.

  The present invention also relates to a method for producing the above optical film, comprising an embossing process for forming the embossed regions at both ends in the width direction of the polymer film.

  In the optical film of the present invention, the air entrained during film winding is effectively held on the film roll over time. Therefore, the optical film of this invention can fully suppress the sticking of films, winding looseness, wrinkles, and generation | occurrence | production of a wrinkle by an air layer at the time of the storage in a roll form. Moreover, winding deviation can be suppressed.

(Optical film)
The optical film according to the present invention has embossed regions at both ends in the width direction of the polymer film, and each embossed region has one or more convex rows substantially parallel to the transport direction. A convex row is a convex region formed intermittently or continuously in the transport direction. In this specification, a convex row in which convex regions are intermittently formed in the transport direction is referred to as an intermittent convex row, and a convex row in which convex regions are continuously formed in the transport direction is referred to as a continuous convex row. Shall. When the convex row is an intermittent convex row, each convex region that intermittently constitutes the convex row is referred to as a convex region unit.

  The embossed regions at both ends in the width direction of the optical film of the present invention independently satisfy the following requirements (I) or (II). That is, the embossed regions at both ends may satisfy the requirement (I), the requirement (II), or the embossed region at one end may satisfy the requirement (I) The embossed region at the end may satisfy the requirement (II). If the embossed regions at both ends meet the requirement (I) or meet the requirement (II), the embossed regions at both ends may have symmetry with respect to the center line in the width direction, Alternatively, they may be different from each other within a predetermined range. The embossed regions at both ends preferably satisfy the requirement (I) in common or satisfy the requirement (II) and have symmetry with respect to the center line in the width direction. Hereinafter, the requirements (I) and (II) will be described in detail, but the description of these requirements is for an embossed region for one end. In this specification, the pattern shape of the convex area | region which an emboss area | region has when it sees from an orthogonal | vertical direction with respect to an optical film surface may be called an emboss pattern.

  (I) When the embossed region has only two or more intermittent convex rows, the arrangement of the convex region units of each intermittent convex row may be any two adjacent in the transport direction so as to inhibit the escape of entrained air. Control is performed between two convex region units and between two arbitrary convex rows adjacent in the width direction. In requirement (I), the embossed region has intermittent convex rows, preferably in 2 to 7 rows, more preferably in 3 to 5 rows. Specifically, for example, in FIG. 1A, the optical film has three intermittent protrusions 1 in parallel in the transport direction (MD direction) in the embossed region 10 at one end in the width direction. When the convex row is an intermittent convex row as described above, each convex region constituting the intermittent convex row is referred to as a convex region unit, and is denoted by 2 in FIG. All the convex area units 2 in all the intermittent convex rows 1 usually have the same dimensions and are repeatedly formed in the transport direction at regular intervals.

  In requirement (I), first, the arrangement of the convex area units is controlled between any two convex area units adjacent in the transport direction. Specifically, in each intermittent convex row 1, the conveyance direction distance x (mm) between any two convex area units 2 adjacent in the conveyance direction (see FIG. 1A) is the conveyance direction length of the convex area unit 2. 0.4 or less, particularly 0.01 to 0.4, preferably 0.01 to 0.25 with respect to the thickness y (mm). If the ratio is too large, the film roll entrainment air cannot be effectively maintained over time, so that sticking, loosening, wrinkling and folding between films cannot be sufficiently suppressed, and winding deviation cannot be sufficiently suppressed.

The conveyance direction distance x (mm) between the convex region units 2 is not particularly limited as long as the above ratio is achieved, and is usually 0.5 to 3 mm, preferably 1 to 2 mm.
The conveyance direction length y (mm) of the convex region unit 2 is not particularly limited as long as the object of the present invention is achieved, and is usually 3 to 20 mm, preferably 5 to 10 mm.

  In requirement (I), the arrangement of the convex region units is further controlled between any two convex rows adjacent in the width direction. Specifically, for any two adjacent rows in the width direction, any one convex region unit in one row is in the vertical cross-sectional perspective view in the width direction, and in the transport direction in the other row. It arrange | positions so that it may overlap with two adjacent convex area | region units. Specifically, as shown in FIG. 1B, any one convex region unit 2a is composed of two convex region units adjacent in the transport direction in adjacent convex rows on the upstream and downstream sides in the transport direction. It arrange | positions so that 2b and 2c may overlap. In FIG. 1B, when attention is paid to one convex region unit 2a in the optical film of FIG. 1A, the convex region unit 2c closest to the convex region unit 2a in the adjacent convex row 1 and the second It is a perpendicular cross-sectional perspective view with respect to the width direction showing the relationship with a close convex region unit 2b. In such a vertical cross-sectional perspective view, when any one convex region unit overlaps only one convex region unit of the adjacent intermittent rows, the entrainment air of the film roll is not effectively maintained with time. Further, sticking between films, loose winding, wrinkles and folds cannot be sufficiently suppressed, and winding deviation cannot be sufficiently suppressed.

  In the vertical sectional perspective view with respect to the width direction, the overlapping direction length z1 (mm) of the overlapping portion of the convex area unit 2a with the convex area unit 2b on the upstream side in the conveying direction and the overlapping with the convex area unit 2c on the downstream side in the conveying direction The smaller length of the partial conveyance direction length z2 (mm) is 0.3 or more, particularly 0.3 to 0.5, relative to the conveyance direction length y (mm) of the convex region unit. If the ratio is too small, the film roll entrainment air is not effectively maintained over time, so that sticking, loosening, wrinkling and folding between films cannot be sufficiently suppressed, and winding deviation cannot be sufficiently suppressed.

  The above relationship in which the convex area unit 2a overlaps with the convex area units 2b and 2c on the upstream side and the downstream side in the transport direction is the same in any one convex area unit in an arbitrary convex line and the adjacent convex line in the present invention. It is satisfied between the convex area unit, the closest convex area unit, and the second closest convex area unit.

  The convex region unit 2 constituting the convex row 1 floats at a predetermined height from a region where the convex region is not formed. For example, in FIG. 1B, the convex area unit 2 (2a, 2b, 2c) is lifted at a predetermined height h from the surface 3 of the area where the convex area is not formed. The height h is not particularly limited as long as the object of the present invention is achieved, and is usually 3 to 30 μm on average, and preferably 5 to 20 μm.

  In the embossed region 10, the area ratio of the convex region is 20 to 80%. If the area ratio of the convex region is too small, the entrainment air of the film roll is not effectively retained, and the effect of suppressing loosening and sticking cannot be obtained. If the area ratio of the convex region is too large, the film roll entrainment air becomes too much, and the loosening of the winding deteriorates.

  The area ratio of the convex region is a ratio of the total area of the convex region 2 to the entire area of the embossed region 10. The embossed region 10 is a minimum region that is divided by a straight line parallel to the transport direction so as to include all the convex regions at one end in the width direction of the film. For example, the embossed region 10 is a region indicated by diagonal lines in FIG. is there.

The distance a between the embossed region 10 and the end face of the optical film (see FIG. 1C), the width b in the width direction of the embossed region 10 (see FIG. 1C), and the convex line adjacent in the width direction. The distance c (see FIG. 1C) is not particularly limited as long as the object of the present invention is achieved.
The distance a is usually 10 mm or less, and preferably 5 mm or less.
The length b is usually 5 to 30 mm, preferably 10 to 20 mm.
The inter-convex distance c is not particularly limited as long as the area ratio of the convex region is achieved, and is usually 0.1 to 5 mm, and preferably 0.5 to 2 mm.

In the optical film of the present invention, the length in the width direction, the length in the transport direction, and the film thickness in the central non-embossed region 5 in the width direction are not particularly limited.
The length in the width direction is usually 1000 to 4000 mm, preferably 1300 to 3000 mm, more preferably 1500 to 3000 mm. Conventionally, the longer the length, the more difficult the air trapped to escape, but the air escapes over time, so problems such as loose winding, wrinkles and breakage are likely to occur. This is because even those lengths can effectively suppress these problems.
The length in the carrying direction is usually 500 to 10000 m, preferably 3000 to 7000 m, and more preferably 4000 to 7000 m. Conventionally, the longer the length, the greater the amount of air trapped. On the other hand, the air escapes over time, so problems such as loose winding, wrinkles and breakage are likely to occur. This is because even those lengths can effectively suppress these problems.
The film thickness in the non-embossed area | region 5 is 20-200 micrometers normally, Preferably it is 20-80 micrometers. The thinner the thickness is, the easier the optical film is to be deformed, so that problems such as loose winding, wrinkles and breakage are likely to occur. However, even with such a thickness, these problems can be effectively suppressed. Because.

  In the emboss pattern shown in FIG. 1A, the convex region unit 2 has a rectangular shape, but is not particularly limited as long as the object of the present invention is achieved. For example, a rhombus shape, a W shape (M shape) ) It may have a shape, a hexagonal shape, a cross shape, or the like.

Specific examples of the emboss pattern in the case where the convex area unit 2 has a rhombus shape are shown in FIGS. 2 (A) to 2 (C).
2A to 2C are the same as FIGS. 1A to 1C except that the convex region unit 2 has a rhombus shape, and thus description thereof is omitted. The same reference numerals in FIGS. 2A to 2C as those in FIGS. 1A to 1C are the same as those in FIGS. 1A to 1C except that the shape of the convex region unit 2 is different. The same meaning content shall be shown.

Specific examples of the emboss pattern when the convex region unit 2 has a W-shape are shown in FIGS. 3 (A) to 3 (C).
3 (A) to 3 (C) are the same as FIGS. 1 (A) to 1 (C), respectively, except that the convex region unit 2 has a W-shape, and thus the description thereof is omitted. . The same reference numerals in FIGS. 3A to 3C as those in FIGS. 1A to 1C are the same as those in FIGS. 1A to 1C except that the shape of the convex region unit 2 is different. The same meaning content shall be shown.

In FIG. 2C and FIG. 3C, the area indicated by hatching is the embossed area 10.

(II) When the embossed region has one or more continuous convex rows, the embossed region may or may not further have intermittent convex rows. That is, all convex arrays included in the embossed area is at least one row, preferably may consist only continuous convex columns 2-7 rows, or one row or more, preferably 1 to 7 column continuously convex It may consist of rows and one or more rows, preferably 1 to 7 rows of intermittent projections. As a specific example of the former case, for example, embossed patterns shown in FIGS. 4A to 4C can be exemplified. As an embodiment in the latter case, for example, an emboss pattern shown in FIGS. 5A to 5C can be exemplified.

  4 (A) to 4 (C) are the same as FIGS. 1 (A) to 1 (C), respectively, except that all the convex rows are continuous convex rows. To do. The same reference numerals as in FIGS. 1A to 1C in FIGS. 4A to 4C are the same as those in FIGS. 1A to 1C except that the convex row is continuous. The same meaning content shall be shown.

  FIGS. 5 (A) to 5 (C) are the same as FIGS. 1 (A) to 1 (C), respectively, except that the embossed region has one continuous convex row and one intermittent convex row. Since these are the same, their description is omitted. The same reference numerals as in FIGS. 1A to 1C in FIGS. 5A to 5C indicate that the number of convex rows is different and that one convex row is a continuous convex row. 1 (A) to 1 (C) have the same meaning content.

  Particularly in requirement (II), as in requirement (I), the area ratio of the convex region in embossed region 10 is 20 to 80%, preferably 30 to 60%. If the area ratio of the convex region is too small, the entrainment air of the film roll is not effectively retained, and the effect of suppressing winding loosening and sticking cannot be obtained. When the area ratio of the convex region is too large, the film roll entrainment air becomes too large, and the winding looseness is deteriorated.

  The area ratio of the convex region is a ratio of the total area of the convex region 2 to the entire area of the embossed region 10. The embossed region 10 is the smallest region delimited by a straight line parallel to the transport direction so as to include all the convex regions at one end in the width direction of the film. For example, in FIG. 4C and FIG. It is an area | region shown by.

  In the requirement (II), the intermittent protrusion that the embossed region may have is not particularly limited, and may be, for example, the same intermittent protrusion as in the requirement (I), or the intermittent protrusion. Intermittent convex rows other than

  The optical film of the present invention is formed with other embossed patterns in addition to the intermittent protrusions and / or continuous protrusions formed substantially parallel to the transport direction in the above requirements (I) and (II). This does not prevent the embossed region from having a convex region or a convex region formed randomly (irregularly).

(Optical film manufacturing method)
The manufacturing method of the optical film which concerns on this invention has the embossing process process which forms the embossing area | region which an above-described optical film has in the width direction both ends of a polymer film.

  As the polymer film used in the embossing process, a film made of a known resin conventionally used in the field of optical films can be used. Specifically, a cellulose resin, a polyester resin, an acrylic resin, Examples thereof include polyvinyl chloride, polyimide, norbornene, and polyolefin. A film made of a cellulose resin is preferably used.

  The cellulose resin has a cellulose ester structure, and specific examples thereof include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose phthalate. Etc. Among these, particularly preferable cellulose resins include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate. A cellulose resin may be used individually by 1 type, or may be used in combination of 2 or more type.

  The polymer film may contain additives such as ultraviolet absorbers, plasticizers, inorganic metal oxides, and fine particles for imparting slipperiness.

  The thickness of the polymer film is preferably in the same range as the film thickness of the non-embossed region in the optical film described above.

  The polymer film may be produced by any known method, and can be produced, for example, by a so-called solution casting method or melt casting method.

  The polymer film may be subjected to shrinkage treatment or stretching treatment, and for example, a polymer film that is shrunk or stretched by 0.8 to 1.5 times in each of the conveyance direction and the width direction may be used.

  The polymer film may have a single layer structure made of the above resin, or may have a multilayer structure having a surface layer made of the above resin on the base material layer.

  The polymer film used in the embossing treatment step in the present invention may be in the middle of production in a conventionally known optical film production method such as so-called solution casting method or melt casting method, or conventionally. The film may be a final product in a known optical film manufacturing method.

  When the polymer film is in the process of being manufactured in a conventionally known method for producing an optical film, the embossing process performed in the present invention is performed as long as the target polymer film has a film form. In the manufacturing method of, it may be carried out between any steps.

For example, when a solution casting method including a so-called casting process, drying process, peeling process, stretching process, and winding process is employed, the embossing process may be performed between the peeling process and the stretching process, Or you may implement between an extending process-winding-up process. In this case, the method for producing an optical film of the present invention may include the steps performed in the following order.
Order (x1); casting process-drying process-peeling process-embossing process-stretching process-winding process;
Order (x2); casting process-drying process-peeling process-stretching process-embossing process-winding process.
In the above case, the drying process is further performed between the peeling process and the embossing process, between the embossing process and the stretching process, between the stretching process and the winding process, between the peeling process and the stretching process, between the stretching process and the embossing process, or the embossing process. You may implement between a process process-winding-up process.

For example, when a melt casting method including a so-called casting process, cooling process, peeling process, stretching process, and winding process is adopted, the embossing process may be performed between the peeling process and the stretching process. Alternatively, the stretching process may be performed between the winding process and the winding process. In this case, the method for producing an optical film of the present invention may include the steps performed in the following order.
Order (y1); casting process-cooling process-peeling process-embossing process-stretching process-winding process;
Order (y2); casting process-cooling process-peeling process-stretching process-embossing process-winding process.
In the above case, the cooling step is further a peeling step-embossing step, embossing step-stretching step, stretching step-winding step, peeling step-stretching step, stretching step-embossing step, or embossing. It may be performed between the process and the winding process.

  In the case of adopting any of the above-described solution casting method or melt casting method, the embossing treatment step is preferably performed immediately before the winding step performed as the final step.

(Embossing process)
The embossing method employed in this step is not particularly limited as long as the above-described convex region can be applied with a predetermined emboss pattern. For example, a method of press molding with a roller, or as disclosed in JP 2007-119181 A Laser irradiation method etc. are mentioned. A laser irradiation method is preferably employed. This is because according to the laser irradiation method, the shape of the convex region, particularly the convex region unit in the intermittent convex row, is not easily deformed.

  In the method for producing an optical film of the present invention, the winding speed of the optical film is usually 15 m / min or more, preferably 60 m / min or more, particularly 80 to 120 m / min. Conventionally, the higher the speed, the greater the amount of air trapped, while the air escapes over time, so problems such as loose winding, wrinkles, and breakage are likely to occur. This is because even the speed can effectively suppress these problems.

(Use)
It is particularly suitable for use as an optical film produced by the above method, for example, a viewing angle widening film, a polarizing plate protective film, a retardation film and the like.

Example 1
[Preparation of dope]
Various components were blended in the following proportions to prepare a dope.
100 parts by weight of cellulose triacetate (Mn = 148000, Mw = 310000, Mw / Mn = 2.1)
Triphenyl phosphate 8 parts by weight Ethylphthalyl ethyl glycolate 2 parts by weight Methylene chloride 440 parts by weight Ethanol 40 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 0.5 part by weight Tinuvin 171 (Ciba Specialty Chemicals) 0.5 parts by weight Aerosil 972V (manufactured by Nippon Aerosil Co., Ltd.) 0.2 parts by weight The above materials are sequentially put into a sealed container, and the temperature in the container is raised from 20 ° C. to 80 ° C., While maintaining the temperature at 80 ° C., the mixture was stirred for 3 hours to completely dissolve the cellulose triacetate. Then, stirring was stopped and the liquid temperature was lowered to 43 ° C. The dope was filtered using a filter paper (Azumi filter paper No. 244, manufactured by Azumi Filter Paper Co., Ltd.) to obtain a dope.

[Preparation of optical film]
The dope was cast from a die onto a mirror-treated stainless steel support belt. The dope temperature was 35 ° C. and the support temperature was 25 ° C. The web was peeled from the support, and a polymer film was produced by stretching 30% in the width direction of the film while holding both ends of the web with clips using a tenter. At this time, the stretching temperature was 140 ° C. The produced film was dried with 120 degreeC drying air. The film thickness was 60 μm.

Subsequently, after performing the embossing process shown below with respect to the surface of a polymer film, the polymer film was wound up and the optical film roll was obtained.
Specifically, in the embossing process, the convex region is a laser having a wavelength of 10.6 μm and an output of 60 W by a CO ₂ laser irradiation device with the dimensions and embossing patterns shown in the table and FIG. Applied by light irradiation. The average height of the convex region was 12 μm. The embossed regions at both ends had symmetry with respect to the center line in the width direction.

(Examples 2-46 / Comparative Examples 1-24)
In the embossing process, a convex region is provided with a predetermined size and an emboss pattern, a polymer film having a predetermined film thickness is used, an optical film having a predetermined width direction length and a conveyance direction length is wound. An optical film roll was obtained in the same manner as in Example 1 except that the film was wound at the take-up speed.

(Evaluation)
<Winding gap>
In the optical film roll 100 shown in FIG. 6, the displacement dimension s was measured with a JIS Class 1 metal scale.

<Loose winding>
In the optical film roll 100 shown in FIG. 6, the upper thickness r1 and the lower thickness r2 of the roll were measured with a JIS class 1 metal ruler, and “r2-r1” was calculated as the loose dimension.

<Stuck with>
The optical film roll was stored at 40 ° C. and 80% humidity for 1 week, and then unwound and evaluated. Specifically, the number of sticking points per lap was counted every 500 m. The number of sticking was the highest number of JIS grade 1 metal scales with a dimension of 0.5 cm or more.

<Overall>
The evaluation results of the above items were comprehensively evaluated. Specifically, the evaluation was based on the optical film roll as the current product obtained in Comparative Example 18.
A: Excellent in two or more items than the current product;
○: 1 item is superior to the current product;
△: equivalent to current product, no effect;
×: Inferior to the current product.

(A) is a schematic schematic diagram of an example of the embossing area | region which the optical film of this invention may have, (B) is a perpendicular cross-sectional perspective view with respect to the width direction of the optical film of (A), (C) is It is a schematic diagram for demonstrating the embossing area | region in the optical film of (A). (A) is a schematic schematic diagram of an example of the embossing area | region which the optical film of this invention may have, (B) is a perpendicular cross-sectional perspective view with respect to the width direction of the optical film of (A), (C) is It is a schematic diagram for demonstrating the embossing area | region in the optical film of (A). (A) is a schematic schematic diagram of an example of the embossing area | region which the optical film of this invention may have, (B) is a perpendicular cross-sectional perspective view with respect to the width direction of the optical film of (A), (C) is It is a schematic diagram for demonstrating the embossing area | region in the optical film of (A). (A) is a schematic schematic diagram of an example of the embossing area | region which the optical film of this invention may have, (B) is a perpendicular cross-sectional perspective view with respect to the width direction of the optical film of (A), (C) is It is a schematic diagram for demonstrating the embossing area | region in the optical film of (A). (A) is a schematic schematic diagram of an example of the embossing area | region which the optical film of this invention may have, (B) is a perpendicular cross-sectional perspective view with respect to the width direction of the optical film of (A), (C) is It is a schematic diagram for demonstrating the embossing area | region in the optical film of (A). It is a schematic sectional drawing of the optical film roll for demonstrating the evaluation method.

Explanation of symbols

  1: intermittent or continuous convex row, 2: 2a: 2b: 2c: convex region (convex region unit), 3: surface of region where convex region is not formed, 5: non-embossed region, 10: embossed region.

Claims (8)

An optical film having embossed regions at both ends in the width direction of the polymer film, and in each embossed region, one or more rows of convex rows in which the convex regions are formed intermittently or continuously substantially parallel to the transport direction. There,
The embossed regions at both ends independently have an area ratio of a convex region of 20 to 80%, and satisfy the following requirements (I) or (II);
(I) The embossed region has only two or more intermittent convex rows formed by intermittently forming convex regions in the transport direction, and between any two convex region units adjacent in the transport direction in each convex row Concerning the conveyance direction distance x (mm) is 0.4 or less with respect to the conveyance direction length y (mm) of the convex region unit, one convex row is in any two convex rows adjacent in the width direction. In the vertical cross-sectional perspective view with respect to the width direction, any one convex area unit in FIG. 2 overlaps with two convex area units adjacent in the transport direction on the upstream side and downstream side in the transport direction, and in the transport direction. The smaller one of the conveyance direction length z1 (mm) of the overlapping portion on the upstream side and the conveyance direction length z2 (mm) of the overlapping portion on the downstream side in the conveyance direction is the conveyance direction length y (mm) of the convex region unit. ) Is 0.3 or more ;
(II) The embossed region has one or more continuous convex rows formed by continuously forming convex regions in the transport direction.   The optical film according to claim 1, wherein a film thickness in a central non-embossed region in the width direction is 20 to 80 μm.   The optical film according to claim 1 or 2, wherein the length in the width direction is 1300 to 3000 mm.   The length of a conveyance direction is 3000-7000m, The optical film in any one of Claims 1-3.   The optical film according to claim 1, comprising a cellulose resin.   It is a method for manufacturing the optical film in any one of Claims 1-5, Comprising: It has the embossing process process which forms the said embossing area | region in the width direction both ends of a polymer film, The optical film characterized by the above-mentioned. Manufacturing method.   The method for producing an optical film according to claim 6, wherein the optical film is wound at a speed of 60 m / min or more.   The method for producing an optical film according to claim 6 or 7, wherein the convex region is formed by a laser irradiation method in the embossing process.

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