JP6455198B2 - Method for producing film with concavo-convex structure and measuring method - Google Patents

Description

  The present invention relates to a method for producing a film with an uneven structure. The present invention also relates to a method for measuring the height of the concavo-convex structure of the film with a concavo-convex structure.

  Conventionally, when a film such as an optical film is manufactured, a certain amount of the film is manufactured into a long shape, and the film is wound and stored as a film roll.

  In the production of a film, it is known to impart a concavo-convex structure to a partial region of the film surface for various purposes. For example, it is known to provide a concavo-convex structure at the end of the film in order to improve the handleability of the film when winding a long film. Such a concavo-convex structure is sometimes referred to as a knurl, and a process for imparting such a concavo-convex structure is referred to by a name such as a knurling process. Examples of specific operations of the knurling treatment include a method of contacting a mold having a concavo-convex structure with a film, a method of applying a layer having a thickness to a film by printing, and a concavo-convex structure by irradiating the film with laser light. Various methods such as a forming method are known. Prior to winding a film into a roll body, a film with a concavo-convex structure is provided by forming a concavo-convex structure on the surface of the film, thereby generating scratches due to friction between the films in the roll body and blocking the film (roll Undesirable phenomena such as a phenomenon in which the surfaces of overlapping films adhere to the body are reduced, and the handleability of the film can be improved.

  In order to efficiently produce a high-quality film, it is required to continuously measure the height of the concavo-convex structure of the film that is continuously conveyed on the conveyance path. For example, the concavo-convex structure imparted to the film is required to control its height within a range with a small deviation from a predetermined target value for the purpose of uniformly expressing the effect. In particular, in the case where the production film is a film used for an optical application, it is required to maintain its optical properties well, so that it is sometimes required to precisely control the height of the nal. In this case, it is required to continuously measure the height of the concavo-convex structure, perform precise quality control, and feed back the measurement result to the process of providing the concavo-convex structure.

  As a method of continuously measuring the height of the concavo-convex structure of the film to be transported, in the film transport path, the height of the film surface in the film thickness direction in the region where the concavo-convex structure is provided and other regions, It is known to measure with a measuring device that reciprocates in the traverse, that is, the film width direction, and calculate the height of the concavo-convex structure based on the measured value (Patent Document 1).

JP 2003-114108 A

  In the measurement by the traverse described in Patent Document 1, the measurement of the height of the concavo-convex structure is low, and the height of the concavo-convex structure that requires precise height control such as a knurl applied to the film roll of the optical film is low. There is a problem that it is insufficient.

  Therefore, the object of the present invention is to provide a high-quality unevenness by measuring the height of the uneven structure, which can accurately measure the height of the uneven structure in the film to be conveyed, and the precise measurement of the uneven structure height. It is providing the manufacturing method of a film with an uneven structure which can manufacture a film with a structure efficiently.

As a result of studying to solve the above-described problem, the present inventor has found that the above-described problem can be solved by using a measuring instrument fixed in the conveyance path instead of measurement by traverse. The present invention has been completed based on such findings.
That is, according to the present invention, the following [1] to [22] are provided.

[1] A step (A) of imparting a concavo-convex structure to a partial region _RH on the surface of a long film that is continuously conveyed in the conveyance path, and a height of the concavo-convex structure of the film in the conveyance path. Measuring the thickness (B)
A method for producing a film with a concavo-convex structure, comprising:
Step (B), in the region R _H, the height H of the film surface in the film thickness direction, in the outer region R _L of the region R _H, and a height L of the film surface in the film thickness direction, A manufacturing method including measuring with a fixed measuring instrument and calculating the difference (HL).
[2] The measurement of the height H is as follows:
A plurality of measurement value groups D obtained by measuring the height of the film surface in the film thickness direction at a plurality of measurement points distributed in alignment in the film width direction over a region WA having a predetermined width in the region _RH . _{Determining the} height H by calculation based on H,
The measurement of the height L is as follows:
In the region _RL , the height of the film surface in the film thickness direction is measured at a plurality of measurement points distributed in alignment in the film width direction over the region WB of a predetermined width, and a plurality of measurement value groups obtained and determining the height L by calculation based on the D _L, the method according to [1].
[3] the height H is based on the measurement value group D _H for obtaining the calculation, an average of the measurement value group D _H, is the same calculations that the height H,
The height L based on the measurement value group D _L for obtaining the calculation, an average of the measurement value group D _L, a this calculation to the height L, production method according to [2] .
[4] The number of measurement points in one area WA is _NH ,
The number of measurement points in one area WB is _NL ,
The height H is based on the measurement value group D _H for obtaining the calculation of the measured value group D _H, it calculates the average of the top X _H number of measurements, be calculated for this height H ,
The height L based on the measurement value group D _L for obtaining the calculation of the measured value group D _L, obtains the average of the top X _L pieces of measurement, be calculated for this height L ,
X _H is a number set within a range of 2 or more and N _H / 2 or less,
Wherein X _L is a number that is set in a range of 2 or more N _L or less, The method according to [2].
[5] The measurement position of the height H and the measurement position of the height L for obtaining one of the difference (HL) values are aligned in the film width direction. [1] The manufacturing method of any one of-[4].
[6] The manufacturing method according to any one of [1] to [5], wherein the measuring device that measures the height H and the measuring device that measures the height L are the same device. Method.
[7] The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, The space | interval of the area | region WA and the said area | region WB is a manufacturing method of any one of [2]-[6] wider than the width | variety of the meandering of the said film conveyed.
[8] The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, The method according to any one of [2] to [7], wherein an interval between the area WA and the area WB is narrower than an average of the width of the area WA and the width of the area WB.
[9] The manufacturing method according to any one of [1] to [8], wherein the step (B) is performed a plurality of times, and the cycle is 0.1 second or less.
[10] The method further includes a step (C) of feedback-controlling the height of the uneven structure provided in the step (A) based on the height value measured in the step (B). [9] The production method according to any one of [9].
[11] In the downstream of the step (B), the method further includes a step (D) of winding the film with an uneven structure into a film roll.
In said process (A), the said uneven structure is provided so that height may become high so that the roll inner side of the said film roll may become low, and the height may become low as the roll outer side. Manufacturing method.
[12] The manufacturing method according to any one of [1] to [11], wherein the region _RH is a region of a film edge.
[13] A measurement method for measuring the height of the concavo-convex structure of a long film having a concavo-convex structure in a partial region _RH on the surface, which is continuously transported in the transport path,
Measurements in the region R _H, the height H of the film surface in the film thickness direction, in the outer region R _L of the region R _H, and a height L of the film surface in the film thickness direction, by a fixed instrument And measuring the difference (HL).
[14] The measurement of the height H is as follows:
A plurality of measurement value groups D obtained by measuring the height of the film surface in the film thickness direction at a plurality of measurement points distributed in alignment in the film width direction over a region WA having a predetermined width in the region _RH . _{Determining the} height H by calculation based on H,
The measurement of the height L is as follows:
In the region _RL , the height of the film surface in the film thickness direction is measured at a plurality of measurement points distributed in alignment in the film width direction over the region WB of a predetermined width, and a plurality of measurement value groups obtained and determining the height L by calculation based on the D _L, the measuring method described in [13].
[15] The height H is based on the measurement value group D _H for obtaining the calculation, an average of the measurement value group D _H, is the same calculations that the height H,
The height L based on the measurement value group D _L for obtaining the calculation, an average of the measurement value group D _L, a this calculation to the height L, the measuring method described in [14] .
[16] The number of measurement points in one area WA is _NH ,
The number of measurement points in one area WB is _NL ,
The height H is based on the measurement value group D _H for obtaining the calculation of the measured value group D _H, it calculates the average of the top X _H number of measurements, be calculated for this height H ,
The height L based on the measurement value group D _L for obtaining the calculation of the measured value group D _L, obtains the average of the top X _L pieces of measurement, be calculated for this height L ,
X _H is a number set within a range of 2 or more and N _H / 2 or less,
Wherein X _L is a number that is set in a range of 2 or more N _L or less, the measuring method described in [14].
[17] The measurement position of the height H and the measurement position of the height L for obtaining one of the difference (HL) values are aligned in the film width direction. [13] The measuring method of any one of-[16].
[18] The measurement according to any one of [13] to [17], wherein the measuring device that measures the height H and the measuring device that measures the height L are the same device. Method.
[19] The region R _H , the region WA, and the region WB are band-like regions that continuously extend in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, The measurement method according to any one of [14] to [18], wherein an interval between the area WA and the area WB is wider than a meandering width of the film to be conveyed.
[20] The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, The measurement method according to any one of [14] to [19], wherein an interval between the area WA and the area WB is narrower than an average of the width of the area WA and the width of the area WB.
[21] The measurement method according to any one of [13] to [20], wherein the measurement is performed a plurality of times and the cycle is 0.1 second or less.
[22] The measurement method according to any one of [13] to [21], wherein the region _RH is a region of a film edge.

  According to the measurement method of the present invention, it is possible to precisely measure the height of the concavo-convex structure in the conveyed film. Moreover, according to the manufacturing method of the film with a concavo-convex structure of the present invention, a high-quality film with a concavo-convex structure can be efficiently manufactured by accurately measuring the height of the concavo-convex structure.

FIG. 1 is a side view schematically showing one embodiment of the production method of the present invention. FIG. 2 is a perspective view schematically showing the vicinity of the support roll 31 in the embodiment shown in FIG. FIG. 3 is a schematic diagram illustrating an example of an image acquired by the light receiver 42A of the measuring instrument 40A in FIG. FIG. 4 is a schematic diagram illustrating an example of an image acquired by the light receiver 42B of the measuring instrument 40B in FIG. FIG. 5 is an enlarged plan view showing a region F of the film 12 in FIG. FIG. 6 is a plan view for explaining a mode in which the region F of the film 12 similar to that in FIG. 5 is measured by the measurement method according to the prior art.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and the claims of the present invention and equivalents thereof. The present invention may be carried out with any change without departing from the above range. In the following description, the direction of the component of the member for carrying out the method of the present invention is “parallel” includes an error within a range that does not significantly impair the effects of the present invention (for example, ± 5 °). Also good. Further, the “long” film means a film having a length of 5 times or more, preferably 10 times or more, more specifically in a roll shape. It has a length enough to be wound up and stored or transported.

[1. Overview〕
In the method for producing a film with a concavo-convex structure of the present invention, the step (A) of imparting a concavo-convex structure to a partial region _RH on the surface of a long film continuously conveyed in the conveyance path, and the conveyance path, The process (B) which measures the height of the uneven structure of a film is included.

  FIG. 1 is a side view schematically showing an embodiment of the manufacturing method of the present invention, and FIG. 2 is a perspective view schematically showing the vicinity of a support roll 31 in the embodiment shown in FIG. In this example, the film 11 supplied from an arbitrary film supply means (not shown) such as a roll of film before providing the concavo-convex structure is transported in the transport direction A1. The flow direction of the film in the production line is also called MD direction (machine direction), and is usually parallel to the longitudinal direction of the long film to be conveyed. Further, a direction perpendicular to the MD direction and parallel to the film surface to be conveyed is also called a TD direction (traverse direction), and usually coincides with the width direction of the long film to be conveyed.

[2. Step (A)]
In the example shown in FIG. 1, the film 11 is conveyed to the uneven | corrugated structure provision apparatus 20, and a process (A) is performed here. In the example shown in FIG. 1, the concavo-convex structure imparting device 20 includes a roll 21 having a concavo-convex structure and a rubber roll 22, and the film 11 is sandwiched between them to impart the concavo-convex structure 13 to the film 11. 12 is formed. However, the apparatus for performing the step (A) in the present invention is not limited to this example, and may be any apparatus that can provide a concavo-convex structure. Moreover, since each figure of this application is a schematic figure, although the uneven structure 13 is shown in the state provided large and sparsely compared with the dimension of the film 12, the uneven structure in the film actually manufactured May be smaller than those illustrated in these drawings or may be more densely provided.

In this example, as shown in FIG. 2, the region _RH to which the concavo-convex structure 13 is imparted extends continuously in the longitudinal direction of the film at the edge adjacent to both widthwise ends 12E of the film 12. A region that is a band-shaped region that is not provided with the uneven structure 13 therebetween is defined as region _RL . The film 12 provided with the concavo-convex structure 13 in the concavo-convex structure applying apparatus 20 is subsequently conveyed to the support roll 31 where the step (B) is performed.

[3. Step (B) and Measurement Method of the Present Invention]
In the step (B) of the production method of the present invention and the measurement method of the present invention, the film surface height _H in the film thickness direction in the region _RH and the film thickness direction in the region _RL outside the region _RH. The film surface height L is measured with a fixed measuring instrument.

  In the example of FIG.1 and FIG.2, the film 12 is supported by the support roll 31, and is conveyed along the conveyance path | route bent along the surrounding surface, and process (B) is performed here. As described above, by performing measurement at the position supported by the peripheral surface of the support roll on the transport path, it is possible to reduce measurement errors that may occur due to fluttering of the film 12.

  The measuring instrument 40 that performs the step (B) includes a projector 41 that projects measurement light in the directions of arrows 44 and 45, a light receiver 42 that receives the light projected by the projector 41, and a support base that supports these. 43. The support base 43 is fixed to the manufacturing apparatus by a support (not shown), and therefore the measuring device 40 measures the film 12 being transported while being fixed in the transport path. The measuring device 40 can be measured by connecting to a controller (not shown) as necessary, and analyzing the information obtained by the measuring device 40 with the controller.

As shown in FIG. 2, in this example, two measuring instruments, a measuring instrument 40 _</ b> A for performing measurement in the region _RH, and a measuring instrument 40 _</ b> B for performing measurement in the region _RL are used as measuring instruments. In FIG. 2, the support for the measuring instrument is omitted for convenience of illustration. In addition, when the regions _RH are provided on both edges of the film 12 as shown in FIG. 2, the step (B) can be performed in both regions, but in FIG. Only the apparatus for measuring the region _RH is shown.

In the measurement operation, the light projected from the light projector 41A of the measuring instrument 40A in the directions of the arrows 44A and 45A is received by the light receiver 42A, whereby the region _{RH of the} film 12 supported by the support roll 31 is obtained. Observe. On the other hand, the light projected in the directions of the arrows 44B and 45B from the light projector 41B of the measuring instrument 40B is received by the light receiver 42B, thereby observing the region _{RL of the} film 12 supported by the support roll 31.

As shown in the example of FIG. 2, the measuring instruments 40A and 40B are preferably measuring heads of a two-dimensional dimension measuring instrument. In the present application, the two-dimensional dimension measuring device is a device that measures a dimension of an outer shape of a measurement target to be observed by acquiring a two-dimensional image of the measurement target and analyzing the position of the measurement target in the image. is there. Examples of the two-dimensional dimension measuring instrument include TM-006, TM-040, and TM-065 (all manufactured by Keyence Corporation) which are measuring heads of the two-dimensional dimension measuring instrument TM-3000 series. In a preferred embodiment, the height H is measured by measuring the height of the film surface in the film thickness direction at a plurality of measurement points aligned and distributed in the film width direction over the area WA having a predetermined width in the area _RH . Measuring the height H by calculation based on a plurality of measured value groups _DH obtained, and measuring the height L in the region _{RL over} the region WB of a predetermined width. Measuring the height of the film surface in the film thickness direction at a plurality of measurement points distributed in line with each other, and calculating the height L by calculation based on the obtained plurality of measurement value groups D _L.

  An example of such measurement using a two-dimensional dimension measuring device will be described with reference to FIGS. 3 is a schematic diagram illustrating an example of an image acquired by the light receiver 42A of the measuring instrument 40A in FIG. 2, and FIG. 4 is an example of an image acquired by the light receiver 42B of the measuring instrument 40B in FIG. FIG.

In FIG. 3, an image 46 _</ b> A is an image obtained by observing the outer shape in the region _{RH of the} film 12 that is supported and conveyed by the support roll 31. Further, the image 46 </ b> A has a vertical direction corresponding to the film thickness direction, and a horizontal direction corresponding to a direction parallel to the axis 3 </ b> X of the support roll 31. In the image 46A, a region WA having a predetermined width is set between the lines 51A and 52A. With the information indicated by the image 46A, the height of the film surface in the film thickness direction at a plurality of positions in the area WA can be detected simultaneously. In the area WA, the surface of the film 12 is observed as an outer shape having various states such as the top portion 13T and the slope 13S of the concavo-convex structure 13 and the area 13S between the concavo-convex structure 13. The height of the film surface is detected at a plurality of measurement points in the area WA observed in this way to obtain a plurality of measurement values, which can be used as a measurement value group _DH .
For determining the height H, calculations based on the measured value group D _H it is not particularly limited, such as increasing or decreasing the height H to reflect the actual height of the increase or decrease of the concavo-convex structure, set any calculation sell. For example, an arithmetic average of the measured value group _DH can be obtained and this can be used as the height H. In this case, as the height H, an average height position indicated by a line 53A can be obtained.
For determining the height H, as another example of the calculation based on the measurement value group D _H, among the measurement value group D _H, it calculates the average of the top X _H number of measurements to the same height H Calculation. Here, the number X _H may be set to an arbitrary value that is 2 or more and less than or equal to the number _NH of measurement points in one area WA. Preferably, X _H can be set within a range of 2 or more and N _H / 2 or less. More specifically, when the number N _H of the measuring point is 100, X _H is preferably be set in a range of 2 or more and 50 or less. In this example, for example, when X _H is set to 10, the highest measured value, the second highest measured value, the third highest measured value, and the tenth measured value in the measured value group _DH. The average of the high measured values is obtained, and this is designated as height H. The value of X _H may set the value as the height H to be calculated is reflected the height of the concavo-convex structure appropriately selected and.

On the other hand, in FIG. 4, an image 46 </ b> B is an image obtained by observing the outer shape in the region _{RL of the} film 12 that is supported and conveyed by the support roll 31. In the image 46B as well as the image 46A, the vertical direction corresponds to the film thickness direction, and the horizontal direction corresponds to a direction parallel to the axis 3X of the support roll 31. In the image 46B, a region WB having a predetermined width is set between the lines 51B and 52B. From the information indicated by the image 46B, a plurality of measurement values can be obtained by simultaneously detecting the height of the film surface in the film thickness direction at a plurality of positions in the region WB, and this can be used as a measurement value group DL.
The calculation based on the measurement value group DL for _obtaining the height L is not particularly limited, and an arbitrary calculation is set so that the increase / decrease in the height L reflects the increase / decrease in the actual film surface height. sell. For example, simply determine the arithmetic mean of the measured value group D _L, can the height L of this. In this case, as the height L, the average height position indicated by the line 53B can be obtained.
For determining the height L, as another example of the calculation based on the measurement value group D _L, of the measurement value group D _L, we obtain the average of the top X _L number of measurements to the same height L Calculation. Here, the number X _L can be set to an arbitrary value that is two or more and less than or equal to the number N _L of measurement points in one area WA. Number X _L may be set to the same value as the number X _H, it may be set to different another value than the number X _H. The value of X _L can set the value as the height L to be calculated is reflected the height of the film surface appropriately selected and.

  In the measurement of one height H in the area WA and the measurement of one height L in the area WB, when measuring at a plurality of measurement points, the upper limit of the number of measurement points depends on the resolution of the measuring instrument, The number of measurement points that can be measured at the resolution is the upper limit. If the measurement is performed at a large number of measurement points below the upper limit, measurement with higher reliability can be performed. On the other hand, by reducing the number of measurement points, the information processing load can be reduced. The number of measurement points in one height H measurement or one height L measurement is preferably 2 or more, more preferably 5 or more, while preferably 1000 or less, more preferably 500 or less. It is.

  The position indicated by the line 53A in the image 46A and the position indicated by the line 53B in the image 46B are determined in the film height direction based on common criteria such as the position of the surface of the support roll 31. By doing so, the heights H and L can be obtained as the distance from the reference to the film surface. For example, the height from the surface 31S of the support roll 31 observed in the image 46A to the position indicated by the line 53A is the height H, and the position indicated by the line 53B from the surface 31S of the support roll 31 observed in the image 46B. The height up to can be the height L. From the heights H and L calculated in this way, the difference (H−L) can be calculated.

  In one image such as the image 46A and the image 46B, by measuring the height at a plurality of measurement points, it is possible to perform measurement at a plurality of measurement points that are aligned and distributed in the film width direction. The alignment of measurement points in the film width direction means that all of the plurality of measurement points are located on a single line parallel to the film width direction. However, there may be an error of about 0.21 mm in the film longitudinal direction. For example, the alignment direction of the measurement points (in the example of FIG. 5, the extending direction of each of the lines 53A-1 to 53A-8) is not completely parallel to the film width direction and is about 3 °. There may be errors.

The region R _H , the region WA, and the region WB can be a band-like region extending continuously in the longitudinal direction of the film. Furthermore, the area WA and the area WB can be areas separated in the width direction. Moreover, it is preferable that the measurement position of the height H and the measurement position of the height L for obtaining one of the differences (HL) are positions aligned in the film width direction. Moreover, a process (B) can be performed in multiple times.

A specific example of such measurement will be described with reference to FIG. FIG. 5 is an enlarged plan view showing a region F of the film 12 in FIG. In FIG. 5, a region _RH to which the concavo-convex structure 13 is given is a region surrounded by lines 61 and 62, and a region _RL is a region inside the film width direction from the line 62 (left side in the figure). is there. The area WA in which a plurality of measurement points between the lines 51A and 52A and the area WB in which a plurality of measurement points between the lines 51B and 52B are distributed shown in FIGS. 3 and 4 are the same in FIG. A reference numeral is attached. As shown in FIG. 5, the area WA and the area WB are band-like areas extending continuously in the longitudinal direction of the film. Furthermore, the area WA and the area WB are separated in the width direction, and the interval is indicated by an arrow WC.

  In FIG. 5, each of the lines 53A-1 to 53A-8 indicates a position where the positions of a plurality of measurement points in one measurement of the height H are aligned and distributed in the film width direction on the film surface. . For example, the positions of a plurality of measurement points in one measurement of the height H are distributed from one end of the line 53A-1 to the other end. Similarly, each of the lines 53B-1 to 53B-8 indicates positions where the positions of a plurality of measurement points in one measurement of the height L are aligned and distributed in the film width direction on the film surface. The line 53A-1 and the line 53B-1 are aligned in the film width direction. Similarly, the line 53A-2, the line 53A-3,... Are aligned with the line 53B-2, the line 53B-3,.

  By calculating the difference between the height H measured by the line 53A-1 and the height L measured by the line 53B-1 at the measurement point having such an arrangement, the difference (H in the position aligned in the film width direction) is obtained. One of the values of -L) can be obtained. Similarly, the difference between the height H measured at line 53A-2 and the height L measured at line 53B-2, the height H measured at line 53A-3, and the height L measured at line 53B-3. Difference between the height H measured by the line 54A-3 and the height L measured by the line 54B-3,... ) One by one. Such measurement can be performed by synchronizing the measurement timings of the measuring instrument 40A and the measuring instrument 40B.

  However, the present invention is not limited to this, and the measurement timings of the measuring instrument 40A and the measuring instrument 40B may not be synchronized. For example, the measurement cycle of the measuring instrument 40A and the measurement cycle of the measuring instrument 40B can be set to the same value, and a plurality of measurements can be performed with only the measurement start timing being aligned. In this case, for example, the difference between the H value obtained in the first measurement and the L value obtained in the first measurement, the H value obtained in the second measurement, and the second measurement. The difference between the obtained L value, the difference between the H value obtained in the third measurement and the L value obtained in the third measurement,... ) One by one. In this case, there may be a deviation of about 10 mm in the film length direction between the measurement position of the height H and the measurement position of the height L for obtaining one of the values of the difference (H−L).

  The effect of the present invention by adopting the step (B) described above will be described in comparison with the prior art shown in FIG. FIG. 6 is a plan view for explaining a mode in which the region F of the film 12 similar to that in FIG. 5 is measured by the measurement method according to the prior art. In the measuring method according to the prior art shown in FIG. 6, the measuring device capable of measuring the height of the film at a certain point is measured by driving the line 63 to line 64 so as to reciprocate in the width direction. Therefore, the measurement points on the film surface are aligned on a line 69 oblique to the film width direction. In this example, for example, the difference between the average value of the plurality of measurement points in the region between the lines 61 and 62 and the average value of the plurality of measurement points in the region from the lines 62 to 64 and the region from the lines 61 to 63. The height of the concavo-convex structure 13 can be obtained.

  However, when the measurement by the traverse shown in FIG. 6 is performed, driving the measuring instrument may cause unintended fluctuations (for example, vibration or the like) in the position of the measuring instrument. Such unintended variations can cause errors in the measurement results. On the other hand, in step (B) in the present invention, since both the height H and the height L are measured by a fixed measuring instrument, an operation for driving the measuring instrument is not performed. As a result, errors due to unintended fluctuations based on driving of the measuring instrument can be reduced. Such an effect is particularly advantageous when the measurement needs to be performed quickly, such as when the film is conveyed at high speed. Therefore, according to the present invention, efficient production can be performed while grasping the height of the concavo-convex structure more precisely.

  Further, the position in the thickness direction of the film transported in the transport path can vary due to movement due to transport. For example, the film 12 on the support roll 31 is not always conveyed in close contact with the peripheral surface of the support roll 31, and may temporarily float from the peripheral surface of the support roll 31. Moreover, when the axis | shaft 3X of the support roll 31 is eccentric, the position of the film 12 of the film 12 conveyed by the rotation of the support roll 31 may fluctuate. In such a case, when the measurement by the traverse shown in FIG. 6 is performed, an error may occur in the measurement result. On the other hand, in the step (B) in the present invention, the measurement position of the height H and the measurement position of the height L for obtaining one of the difference (HL) values are aligned in the film width direction. If it is a position, these measurements will be performed simultaneously, and the variation in the measurement value based on the variation in the position of the film in the thickness direction will be offset by obtaining the difference, resulting in an error due to such variation. Can be reduced.

Moreover, the film conveyed in a conveyance path may meander in the width direction. That is, when a continuously transported film is observed at a certain position on the transport path, the film position may fluctuate in the width direction. In that case, when the region _RH is a belt-like region extending continuously in the longitudinal direction of the film, the position through which the region _RH passes can also vary in the width direction. Here, since the region WA and the region WB are separated from each other in the width direction, the region WA temporarily deviates from the region _RH due to such meandering, or the region WB overlaps the region _RH. This can be reduced. Therefore, in a preferred embodiment, the interval between the region WA and the region WB (interval indicated by the arrow WC in FIG. 5) is preferably wider than the meandering width of the film being conveyed. The meandering width of the film can be determined by actually transporting the film and observing the position of the film being transported.

On the other hand, if the distance between the area WA and the area WB is too wide, the variation in the position in the thickness direction of the film based on the temporary lifting of the film, the eccentricity of the support roll, etc. described above may occur. As a result, by measuring the heights H and L at the same time, the rate at which such fluctuations are offset can be reduced. For this reason, the interval between the region WA and the region WB (the interval indicated by the arrow WC in FIG. 5) is preferably a narrow interval of a predetermined value or less. Specifically, or become position area WA even when meandering film as described above is out of the region R _H, that region WB is close to the extent not to overlap or to the region R _H Preferably, the distance between the area WA and the area WB is narrower than the average of the width of the area WA and the width of the area WB.

  Moreover, when the measurement by the traverse shown in FIG. 6 is performed, when the height of the concavo-convex structure is obtained as an average value of a large number of measurement values, the average value based on the measurement results in the long region in the longitudinal direction of the film Will be asked. On the other hand, in the step (B) in the present invention, the height H is obtained as an average of the measurement values at a plurality of measurement points distributed and aligned in the film width direction over the area WA, and the height L is determined in the area WB. By obtaining the average of the measurement values at a plurality of measurement points distributed in alignment across the film width direction, it is possible to obtain an average value based on a large number of measurement values in a measurement in a shorter region in the longitudinal direction of the film, As a result, fluctuations in the height of the concavo-convex structure can be grasped more quickly.

  In the step (B), the variation in the height of the concavo-convex structure formed in the step (A) is reduced by narrowing the pitch in the film longitudinal direction (indicated by arrows PA and PB in FIG. 5) at the measurement position. Can be grasped more quickly. By repeating the step (B) at a short cycle and performing a plurality of times, the pitch of the measurement positions can be narrowed. Specifically, for example, the period of the step (B) can be preferably 0.1 seconds or less, more preferably 0.01 seconds or less.

  In the production method of the present invention, the slower the film conveyance speed, the easier the measurement of a short pitch, whereas the faster the film conveyance speed, the more efficient production becomes possible. A preferable conveyance speed is, for example, 5 m / min to 200 m / min. More preferably, it is 10 m / min to 100 m / min.

  In the embodiment described above, separate measuring instruments 40A and 40B are used as a measuring instrument for measuring the height H and a measuring instrument for measuring the height L. However, the manufacturing method of the present invention is not limited to this. For example, a measuring instrument that measures the height H and a measuring instrument that measures the height L can be the same device. Specifically, by using a measuring instrument capable of observing the area WA and the area WB in one image and observing the area WA and the area WB in one image, the measurement by the same apparatus can be performed. Yes. By performing the measurement using the same device, it is possible to more accurately synchronize the measurement timings of the measuring instrument 40A and the measuring instrument 40B, and as a result, the difference (H−L) is one of the values. Alignment in the film width direction between the measurement position of the height H and the measurement position of the height L for determining the thickness can be achieved more accurately.

[4. Step (C)]
The production method of the present invention may further include a step (C) of feedback-controlling the height of the concavo-convex structure provided in the step (A) based on the height value measured in the step (B).
The feedback control of the height of the concavo-convex structure in the present application is control for reducing a deviation between the measured value measured in the step (B) and the target value of the height of the concavo-convex structure. Specifically, when the measured value measured in the step (B) is larger than the target value of the height of the concavo-convex structure, the height of the concavo-convex structure applied in the step (A) is controlled to be small, When the measured value measured in B) is smaller than the target height of the concavo-convex structure, control is performed to increase the height of the concavo-convex structure provided in the step (A). Such feedback control can also be performed by manually adjusting a device that performs the step (A) based on the measurement value obtained in the step (B), and can be performed based on the measurement value obtained in the step (B) ( It is also possible to automatically adjust the apparatus for performing A).

  When H and L are average values of a plurality of measured values in the regions WA and WB, the value of the difference (HL) is, for example, from the flat surface of the film 12 to the top of the concavo-convex structure (top 13T in FIG. 3). It is calculated as a value lower than the height of. However, even in such a case, the value of the difference (HL) correlates with the height of the top of the concavo-convex structure, and therefore can be used effectively for feedback control of the height of the concavo-convex structure.

  The target value of the difference (H−L) can be set as appropriate so that a concavo-convex structure having a desired height can be obtained. For example, when forming a knurl for improving the handleability of a film when winding a long film as a concavo-convex structure, the target value of the difference (H−L) is within a range of 3 to 100 μm, for example, Preferably, it can be appropriately set within the range of 5 to 50 μm.

  The height of the concavo-convex structure imparted in the step (A) can be adjusted by appropriately changing the operating conditions of the concavo-convex structure imparting device used in the step (A). For example, when an apparatus 20 including a roll 21 having a concavo-convex structure and a rubber roll 22 as shown in FIG. 1 is used as the concavo-convex structure imparting apparatus, by changing the pressure between which the film 11 is sandwiched, the height of the concavo-convex structure 13 can be increased. Can be adjusted.

  In addition, when using a device for applying a layer having a thickness to a film by printing, for example, as a concavo-convex structure applying device, by changing the printing conditions to change the thickness of the printed layer constituting the concavo-convex structure, The height of the structure can be adjusted. In addition, for example, when using an apparatus that imparts a concavo-convex structure with a laser, the height of the concavo-convex structure can be adjusted by changing the laser output.

[5. Step (D)]
The production method of the present invention may further include a step (D) of winding the film with a concavo-convex structure into a film roll downstream of the step (B). By forming such a roll, the film with a concavo-convex structure produced by the production method of the present invention can be easily stored and transported.

  In the case of forming such a film roll, in the step (A), the height of the concavo-convex structure is higher on the inner side of the film roll (that is, the portion closer to the core of the film roll), and the outer side (that is, from the core of the film roll). It is preferable to apply such that the farther part) the lower the height. In general, in film rolls, the closer to the center, the higher the pressure acting between the faces of the film, so that the inner side of the winding is higher and the lower side is lower, giving a uniform structure as a knurl. The concavo-convex structure functioning in

  Specifically, such a film roll provides a high concavo-convex structure immediately after the start of production of a continuous film with a concavo-convex structure, and then increases the height of the concavo-convex structure so that the concavo-convex structure is successively lowered. It can be manufactured by controlling and winding a film having a concavo-convex structure. According to the production method of the present invention, precise measurement of the height of the concavo-convex structure can be easily performed in the step (B), and thus a film roll having such a concavo-convex structure can be easily obtained.

[6. (Use of film with uneven structure)
The use of the film with an uneven structure produced by the production method of the present invention is not particularly limited, and the function of the uneven structure in the film is not particularly limited. A preferable example of the film with a concavo-convex structure is an optical film. Moreover, as a preferable example of the uneven | corrugated structure in the said optical film, what functions as a knurl for the improvement of the handleability of the film at the time of winding a film is mentioned. Such a knurl can be a knurl applied to the film edge, as in the example shown in FIGS. By applying such a knurl, when a film with a concavo-convex structure is wound into a film roll, undesired phenomena such as scratching due to friction in the part where the knurl has not been applied, blocking of the film, etc. are reduced, The film with an uneven structure as an optical film can be easily stored and transported while maintaining the quality.

[7. (Modification)
The production method of the present invention and the measurement method of the present invention are not limited to the examples specifically described above, and may be variously modified.
For example, in the example shown in FIG. 2 and FIG. 5, as the region _RL outside the region _RH , the region on the inner side in the film width direction than the region _RH is set, but the present invention is not limited to this, and the region A region on the inner side in the film width direction from _RH may be set as the region _RL . However, the region on the inner side in the film width direction of the region _RH has less fluctuation in the position in the thickness direction of the film to be conveyed, and more accurate measurement can be performed by setting this region as the region _RL .

Further, for example, in the example shown in FIGS. 2 and 5, the region _RH is a belt-like region continuously extending in the longitudinal direction of the film at both edges of the film, but the present invention is not limited thereto. The region _RH may be provided only at one edge of the film, or may be provided at the center of the film. Further, if necessary, there may be discontinuous portions in the longitudinal direction of the film.

  In addition, for example, in the example shown in FIGS. 1 to 5, the measuring head of the two-dimensional dimension measuring device is used as the measuring instrument, but the present invention is not limited to this, for example, instead of the two-dimensional dimension measuring device, You may use the three-dimensional dimension measuring device which can measure a three-dimensional shape continuously.

  Moreover, in the manufacturing method of this invention, process (C) and (D) are arbitrary. In the case where the step (C) is not performed, for example, only those whose height of the concavo-convex structure falls within the target value can be selected as a final product.

[8. (Shape of film)
The dimension of the film used for the measurement method and the production method of the present invention is not particularly limited, and may be any dimension desired as a product. The thickness of the film is preferably 1 to 1000 μm, more preferably 5 μm to 300 μm, and even more preferably 10 μm to 150 μm. The width of the film is preferably 700 to 2500 mm, more preferably 1000 mm to 2200 mm, and even more preferably 1200 mm to 2000 mm. The length of the film is not particularly limited as long as it is long, and may be, for example, 10 to 10,000 m.

  The size of the concavo-convex structure of the film with a concavo-convex structure is not particularly limited, and may be any dimension desired as a product. For example, the average height of the concavo-convex structure can be 0.01 to 1000 μm.

[9. Film material)
The material of the film used for the measurement method and the production method of the present invention is not particularly limited, and various films can be used. The film may be a stretched film or an unstretched film.

  When using a film with a concavo-convex structure as an optical film, it is usually preferable that the film has high transparency from the viewpoint of exhibiting a function as an optical member. Specifically, the total light transmittance of the film is preferably 80% or more, and more preferably 90% or more. Here, the total light transmittance is an average value obtained by measuring five places using “turbidimeter NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS K7105.

  Moreover, when using a film with a concavo-convex structure as an optical film, it is usually preferable that the film has a small haze. Specifically, the haze of the film is preferably 5% or less, more preferably 3% or less, and particularly preferably 2% or less. By setting the haze to a low value, when a film piece cut out from a film with a concavo-convex structure is incorporated in a display device, the clarity of a display image of the display device can be improved. Here, the haze can be measured using a turbidimeter “NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.

  The film used in the present invention is usually a film comprising one or more thermoplastic resin layers containing various polymers. Such polymers include hydrocarbon polymers, (meth) acrylic polymers and polyesters.

  The film to be subjected to the production method of the present invention preferably contains a hydrocarbon polymer. The “including hydrocarbon polymer” film includes a film including one or more resin layers including a hydrocarbon polymer, one or more resin layers including a hydrocarbon polymer, and one other layer. Both films comprising the above are included.

  The hydrocarbon polymer refers to a polymer in which at least a part of the repeating unit of the polymer is a hydrocarbon group. The proportion of the hydrocarbon group which is a repeating unit in the hydrocarbon polymer can be appropriately selected according to the purpose of use, but is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight. That's it.

  As the hydrocarbon polymer, an alicyclic structure-containing polymer is preferable. An alicyclic structure-containing polymer is a polymer having an alicyclic structure in the repeating unit of the polymer, a polymer having an alicyclic structure in the main chain, and an alicyclic structure in the side chain. Any of the polymers it has may be used. Among these, a polymer containing an alicyclic structure in the main chain is preferable from the viewpoint of mechanical strength, heat resistance, and the like.

  Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure. Among these, from the viewpoints of mechanical strength, heat resistance and the like, 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, preferably 30 or less, more preferably 20 or less, particularly preferably per alicyclic structure. Is in the range of 15 or less, the mechanical strength, heat resistance, and film formability are highly balanced, which is preferable.

  The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer can be appropriately selected according to the purpose of use, but is preferably 55% by weight or more, more preferably 70% by weight or more, particularly preferably. 90% by weight or more. When the ratio of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is in this range, it is preferable from the viewpoint of transparency and heat resistance of the film.

  Examples of alicyclic structure-containing polymers include norbornene polymers, monocyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof. Can be mentioned. Among these, norbornene-based polymers can be suitably used because of their good transparency and moldability.

  As the norbornene-based polymer, for example, a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof; An addition polymer of a monomer having a norbornene structure, an addition copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof. Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Can be used. “(Co) polymer” means a polymer and a copolymer.

Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (common name: norbornene), tricyclo [4.3.0.1 ^2,5 ] deca-3,7. -Diene (common name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo [4.4. 0.1 ^2,5 . ^{17, 10} ] dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent in the ring). Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. Moreover, these substituents may be the same or different, and a plurality thereof may be bonded to the ring. One type of monomer having a norbornene structure may be used alone, or two or more types may be used in combination at any ratio.

  Examples of the polar group include a hetero atom or an atomic group having a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Specific examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, and a sulfonic acid group.

  Other monomers capable of ring-opening copolymerization with a monomer having a norbornene structure include, for example, monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; and cyclic conjugates such as cyclohexadiene and cycloheptadiene. Dienes and derivatives thereof; and the like. As the other monomer capable of ring-opening copolymerization with a monomer having a norbornene structure, one type may be used alone, or two or more types may be used in combination at any ratio.

  A ring-opening polymer of a monomer having a norbornene structure and a ring-opening copolymer with another monomer copolymerizable with a monomer having a norbornene structure are, for example, a known ring-opening monomer. It can be obtained by polymerization or copolymerization in the presence of a polymerization catalyst.

  Examples of other monomers that can be addition copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; cyclobutene, cyclopentene, And cycloolefins such as cyclohexene and derivatives thereof; non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene; and the like. Among these, α-olefin is preferable and ethylene is more preferable. As the other monomer capable of addition copolymerization with a monomer having a norbornene structure, one type may be used alone, or two or more types may be used in combination at any ratio.

  An addition polymer of a monomer having a norbornene structure and an addition copolymer of another monomer copolymerizable with the monomer having a norbornene structure are, for example, a known addition polymerization catalyst. It can be obtained by polymerization or copolymerization in the presence.

  Examples of the monocyclic olefin polymer include addition polymers of a cyclic olefin monomer having a single ring such as cyclohexene, cycloheptene, and cyclooctene.

  Examples of the cyclic conjugated diene polymer include polymers obtained by cyclization reaction of addition polymers of conjugated diene monomers such as 1,3-butadiene, isoprene and chloroprene; cyclic conjugates such as cyclopentadiene and cyclohexadiene. And 1,2- or 1,4-addition polymers of diene monomers; and their hydrides.

  Examples of vinyl alicyclic hydrocarbon polymers include polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane and their hydrides; vinyl aromatic hydrocarbons such as styrene and α-methylstyrene. Hydrogenated product obtained by hydrogenating an aromatic ring part contained in a polymer obtained by polymerizing monomers; vinyl alicyclic hydrocarbon monomer, or vinyl aromatic hydrocarbon monomer and vinyl aromatic hydrocarbon monomer And an aromatic ring hydride of a copolymer such as a random copolymer or a block copolymer with another copolymerizable monomer. Examples of the block copolymer include a diblock copolymer, a triblock copolymer or a multi-block copolymer having more than that, a gradient block copolymer, and the like.

  The molecular weight of the hydrocarbon polymer is appropriately selected according to the purpose of use, but gel permeation chromatography using cyclohexane as a solvent (however, if the sample does not dissolve in cyclohexane, toluene may be used). The polyisoprene or polystyrene-equivalent weight average molecular weight (Mw) measured in (1) is usually 10,000 or more, preferably 15,000 or more, more preferably 20,000 or more, and usually 100,000 or less, preferably 80,000. 000 or less, more preferably 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and molding processability of the film are highly balanced and suitable.

  The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the hydrocarbon polymer is usually 1.2 or more, preferably 1.5 or more, more preferably 1.8 or more, usually 3.5. Hereinafter, it is preferably 3.0 or less, more preferably 2.7 or less. When a film with a concavo-convex structure is used as an optical film, when the molecular weight distribution of the hydrocarbon polymer exceeds 3.5, the low-molecular component increases, so the component with a short relaxation time increases, and it has the same in-plane retardation Re at first glance. Even if it is a film, it is estimated that relaxation at high temperature increases in a short time, and the stability of the film may be lowered. On the other hand, when the molecular weight distribution is less than 1.2, the productivity of the hydrocarbon polymer can be reduced and the cost can be increased.

  The glass transition temperature of the hydrocarbon polymer can be appropriately selected according to the purpose of use, but is preferably 130 ° C. or higher, more preferably 135 ° C. or higher, preferably 150 ° C. or lower, more preferably 145 ° C. or lower. . When the glass transition temperature is lower than 130 ° C., durability at high temperatures may be deteriorated. When the glass transition temperature is higher than 150 ° C., durability is improved, but normal stretching may be difficult.

  The resin layer constituting the film may contain other optional components in addition to the polymer such as the alicyclic structure-containing polymer as long as the effects of the present invention are not significantly impaired. Examples of optional components include colorants such as pigments and dyes; fluorescent brighteners; dispersants; thermal stabilizers; light stabilizers; ultraviolet absorbers; antistatic agents; antioxidants; Is mentioned. In addition, an arbitrary component may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. However, the resin layer constituting the film preferably contains about 50% to 100% or about 70% to 100% of a polymer such as an alicyclic structure-containing polymer.

  The film used in the present invention can be obtained by molding a resin by a known film molding method. Examples of the film forming method include a cast forming method, an extrusion forming method, and an inflation forming method. Among these, the melt extrusion method that does not use a solvent can reduce the amount of residual volatile components efficiently, and is preferable from the viewpoints of the global environment and work environment, and excellent manufacturing efficiency. Examples of the melt extrusion method include an inflation method using a die, and a method using a T die is preferable in terms of excellent productivity and thickness accuracy. The obtained resin layer can be used as it is as a film for use in the production method of the present invention. Alternatively, an arbitrary layer such as a slippery layer or an antistatic layer may be arbitrarily formed on the surface of the obtained resin layer, and this may be used as a film used in the present invention.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples shown below, and the scope of the claims of the present invention and the equivalents thereof are not deviated from. You may carry out by changing arbitrarily. The operations described below were performed in an environment of normal temperature and pressure unless otherwise specified.

<Example 1>
(1-1. Preparation of Film)
A pellet of an alicyclic structure-containing polymer resin (“ZEONOR” manufactured by Nippon Zeon Co., Ltd .; glass transition temperature: 135 ° C.) was dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated. A film having a thickness of 20 μm, a width of 1200 mm, and a length of 4000 m using a T-die type film melt extrusion molding machine having a resin melt kneader equipped with a screw, under a molding condition of a molten resin temperature of 270 ° C. and a T die width of 1500 mm. Was prepared.

(1-2. Step (A): Provision of Concavity and convexity structure)
Using the apparatus schematically shown in FIGS. 1 to 4, a step (A) for imparting a concavo-convex structure and a step (B) for measuring the height of the concavo-convex structure were performed.
The film 12 prepared in (1-1) was transported to the concavo-convex structure imparting device 20 at a transport speed of 25 m / min. A roll 21 having a concavo-convex structure was pressed against the region _RH at both ends of the film 12, the concavo-convex structure was transferred to the film, and a concavo-convex structure was imparted to obtain a film with a concavo-convex structure. The width of the region _RH was 15 mm, and the width of the region _RL between them was 1160 mm.

(1-3. Process (B): Measurement of height of uneven structure)
The average height H and area of the area WA in the area _{RH on the} film surface are obtained by using the measuring instruments 40A and 40B, which are guided to the support roll 31 and fixed to the support roll 31. The average height _L of the region WB in R _L was measured. As the measuring instrument, a two-dimensional dimension measuring instrument TM-040 (measuring head) was used. Information acquired by each measuring instrument is analyzed by a controller (trade name “TM-3000”, manufactured by Keyence Corporation) connected to each measuring instrument one by one, and heights H and L are obtained. The difference (HL) was calculated. The specific procedure for measurement is as follows.

  (I) In one measurement of the average height H of the area WA, in the area of 4 mm width between the lines 51A and 52A, 100 measurement points that are aligned in a line in the film width direction and distributed at equal intervals The height of the film surface in the film thickness direction was measured, and the average of a plurality of measured values obtained was calculated as the height H.

  (Ii) In one measurement of the average height B of the region WB, in the region of 5 mm width between the lines 51B and 52B, 100 measurement points that are aligned in a line in the film width direction and are equally spaced The height of the film surface in the film thickness direction was measured, and the average of a plurality of measured values obtained was calculated as the height L. The distance between the area WA and the area WB (corresponding to the distance indicated by the arrow WC in FIG. 5) was 10 mm.

  (Iii) The difference (H−L) was determined from one measured value of H and one measured value of L.

  (Iv) (i) to (iii) were repeated at a cycle of 0.01 seconds, and the film 12 was measured over 4000 m. The measurement by the measuring instrument 40A and the measurement by the measuring instrument 40B were not particularly synchronized. However, the measurement start timing is the same, the difference between the H value obtained in the first measurement and the L value obtained in the first measurement, the H value obtained in the second measurement, and 2 By sequentially obtaining the difference from the L value obtained in the third measurement, the difference between the H value obtained in the third measurement and the L value obtained in the third measurement,... The difference (HL) values were determined one by one. The measurement position of height H and the measurement position of height L for obtaining one of the differences (HL) were shifted by a maximum of 10 mm in the film length direction. The film conveyance speed was set to 25 m / min as in the step (A). As a result, 960000 measured values of (HL) were obtained.

(1-4. Process (D))
A film with a concavo-convex structure was wound downstream of the step (B) to form a film roll.

(1-5. Evaluation)
The standard deviation σ of 960000 (HL) values obtained in (1-3) was determined to be 1.7 μm.

<Example 2>
As a measurement object, the film drawn out from the film roll obtained in the step (1-4) of Example 1 was used, and the width of the region between the lines 51A and 52A in (1-3) (i), And (ii) Except having changed the width | variety of the area | region between the lines 51B and 52B into 2 mm, it is the same as (1-3)-(1-5) of Example 1, and extends the film 12 over 4000 m. The standard deviation was determined by measurement. As a result, the standard deviation σ was 1.8 μm.

<Examples 3 to 4>
(1-3) The width of the region between the lines 51A and 52A in (i) and the width of the region between the lines 51B and 52B in (ii) are 0.5 mm (Example 3) or 8 mm (Example). The film 12 was measured over 4000 m in the same manner as in Example 2 except for changing to 4), and the standard deviation was obtained. As a result, the standard deviation σ was 1.9 μm in Example 3 and 1.6 μm in Example 4.

<Example 5>
Except for the following points, the film 12 was measured over 4000 m in the same manner as in Example 2 to obtain the standard deviation.
(1-3) The width of the region between the lines 51A and 52A in (i) and the width of the region between the lines 51B and 52B in (ii) are set to 5 mm as in the first embodiment. The measurement by 40A and the measurement by the measuring instrument 40B are synchronized by an external input signal, and as a result, the measurement position of the height H and the measurement position of the height L for obtaining each difference (HL) value are obtained. The position was aligned in the film width direction.
As a result, the standard deviation σ was 1.4 μm.

<Example 6>
Except for the following points, the film 12 was measured over 4000 m in the same manner as in Example 5 to obtain the standard deviation.
In (1-3), the measuring device that measures the height H and the measuring device that measures the height L are the same device. That is, the area WA and the area WB are observed with one measuring instrument (two-dimensional dimension measuring instrument measuring head, trade name “TM-040”, manufactured by Keyence Corporation), and the acquired information is acquired by one controller. (Trade name “TM-3000”, manufactured by Keyence Corporation), and the height H in the area WA, the height L in the area WB, and the difference (HL) between them were calculated. Therefore, the measurement position of the height H and the measurement position of the height L for obtaining each difference (HL) value are aligned more accurately in the film width direction than in Example 5. .
As a result, the standard deviation σ was 1.3 μm.

<Example 7>
The film 12 was measured over 4000 m in the same manner as in Example 6 except that the distance between the area WA and the area WB was changed to 3 mm, and the standard deviation was obtained. As a result, the standard deviation σ was 1.1 μm.

<Comparative Example 1>
Using the measuring device that traverses the height of the concavo-convex structure over both the regions _RH and _RL , the film 12 with the concavo-convex structure subjected to measurement in Examples 1 to 7 was measured over 4000 m.
The film with a concavo-convex structure was guided to the support roll 31, and the film surface area _RH and the film surface height in the outer area were measured using a measuring instrument that traversed in the film width direction. As a measuring instrument, a dimension measuring instrument (trade name “LS-9030”, manufactured by Keyence Corporation) was used, and the measurement was repeated at a period of 0.01 seconds while traversing the measuring instrument. The locus of the measurement points on the film surface was as shown by the oblique line 69 shown in FIG. The traverse amplitude (distance between lines 63 to 64 in FIG. 6) is 30 mm, and the traverse distance from the region _RH to the film edge side (distance between lines 61 to 63 in FIG. 6) is 7.5 mm. The distance of the traverse from the region _RH to the center of the film (distance between lines 62 to 64 in FIG. 6) was 7.5 mm. The cycle of one round trip of the traverse was 5 seconds (12 mm / sec). Moreover, the conveyance speed of the film with a concavo-convex structure was 25 m / min as in the examples.

  As a result, 960000 measured values of the film surface height were obtained. A set of these measurements in a single one-way traverse (ie, a set of measurements while the instrument moves from the position of line 63 to the position of line 64, or the instrument moves from the position of line 64 to the line 63. Average of measured values between lines 61 and 62, average between measured values between lines 62 and 64, and between lines 61 and 63 in the set of measured values while moving to position) L ′ was obtained and the difference (H′−L ′) was calculated. The standard deviation σ of the obtained 3840 (H′−L ′) values was found to be 3.1 μm.

  The results of Examples 1 to 7 and Comparative Example 1 are summarized in Table 1.

  In Examples 1-7 and Comparative Example 1, since the measurement is performed using the same roll of a film with a concavo-convex structure as a measurement target, the same standard deviation value is obtained if the measurement precision is the same. Where to be done, the standard deviation values varied as indicated above. The standard deviation of the measurement results in Examples 1 to 7 in which the step (B) in the production method of the present invention was adopted was smaller than that in Comparative Example 1. Particularly, in Example 5 in which the measurement of the height H and the height L was synchronized, the standard deviation σ was small, and in Examples 6 to 7 in which measurement was performed with one measuring instrument, the standard deviation σ was further increased. In Example 7, in which the measurement was performed with a single measuring instrument and the interval between the measurement positions was narrowed to 3 mm, a particularly small standard deviation σ was obtained.

DESCRIPTION OF SYMBOLS 11: Film 12: Film with uneven structure 12E: End part of film width direction 13: Uneven structure 13T: Top of uneven structure 13S: Slope of uneven structure 13S: Area between uneven structures 20: Uneven structure imparting device 21: Uneven Roll having structure 22: Rubber roll 31: Support roll 31S: Surface of support roll 3X: Support roll shaft 40: Measuring instrument 40A: Measuring instrument for measurement in region _RH 40B: For measuring in region _RL Measuring instrument 41: projector 42: light receiver 43: support base 46A: image 46B: image _RH : region with concavo-convex structure _RL : region without concavo-convex structure

Claims (22)

A step (A) of imparting a concavo-convex structure to a partial region _RH on the surface of a long film continuously conveyed in the conveyance path, and measuring the height of the concavo-convex structure of the film in the conveyance path Step (B)
A method for producing a film with a concavo-convex structure, comprising:
Step (B), in the region R _H, the height H of the film surface in the film thickness direction, in the outer region R _L of the region R _H, and a height L of the film surface in the film thickness direction, measured by a fixed instrument, seen including a calculating the difference (H-L),
The height H is a height based on the surface of the support roll in the region _RH of the film supported and conveyed by the support roll.
The said height L is a manufacturing method which is the height on the basis of the surface of the said support roll in the said area | region _RL of the film supported and conveyed by the support roll . The measurement of the height H is as follows:
A plurality of measurement value groups D obtained by measuring the height of the film surface in the film thickness direction at a plurality of measurement points distributed in alignment in the film width direction over a region WA having a predetermined width in the region _RH . _{Determining the} height H by calculation based on H,
The measurement of the height L is as follows:
In the region _RL , the height of the film surface in the film thickness direction is measured at a plurality of measurement points distributed in alignment in the film width direction over the region WB of a predetermined width, and a plurality of measurement value groups obtained and determining the height L by calculation based on the D _L, the method according to claim 1. Calculation based on the measurement value group D _H for determining the height H is, an average of the measurement value group D _H, and which is calculated according to the height H,
The height L based on the measurement value group D _L for obtaining the calculation, an average of the measurement value group D _L, a this calculation to the height L, the manufacturing method according to claim 2 . The number of measurement points in one area WA is _NH ,
The number of measurement points in one area WB is _NL ,
The height H is based on the measurement value group D _H for obtaining the calculation of the measured value group D _H, it calculates the average of the top X _H number of measurements, be calculated for this height H ,
The height L based on the measurement value group D _L for obtaining the calculation of the measured value group D _L, obtains the average of the top X _L pieces of measurement, be calculated for this height L ,
X _H is a number set within a range of 2 or more and N _H / 2 or less,
Wherein X _L is a number that is set in the range of 2 or more N _L, the manufacturing method according to claim 2.   The measurement position of the height H and the measurement position of the height L for obtaining one value of the difference (HL) are positions aligned in the film width direction. The manufacturing method of any one of Claims.   The manufacturing method according to claim 1, wherein the measuring instrument that measures the height H and the measuring instrument that measures the height L are the same device. The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, and the region WA The manufacturing method according to any one of claims 2 to 6, wherein a distance from the region WB is wider than a meandering width of the film to be conveyed. The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, and the region WA The manufacturing method according to any one of claims 2 to 7, wherein an interval with the region WB is narrower than an average of a width of the region WA and a width of the region WB.   The manufacturing method of any one of Claims 1-8 whose said process (B) is performed in multiple times and the period is 0.1 second or less.   The process according to any one of claims 1 to 9, further comprising a step (C) of feedback controlling the height of the concavo-convex structure provided in the step (A) based on the height value measured in the step (B). The production method according to claim 1. In the downstream of the step (B), the method further includes a step (D) of winding the film with an uneven structure into a film roll.
11. The production according to claim 1, wherein in the step (A), the uneven structure is applied such that the height is higher toward the inner side of the film roll and lower toward the outer side of the film roll. Method. The manufacturing method according to claim 1, wherein the region _RH is a film edge region. A measurement method for measuring the height of the concavo-convex structure of a long film having a concavo-convex structure in a partial region _RH on the surface, which is continuously transported in a transport path,
Measurements in the region R _H, the height H of the film surface in the film thickness direction, in the outer region R _L of the region R _H, and a height L of the film surface in the film thickness direction, by a fixed instrument and, viewed it contains a calculating the difference (H-L),
The height H is a height based on the surface of the support roll in the region _RH of the film supported and conveyed by the support roll.
The said height L is a measuring method which is the height on the basis of the surface of the said support roll in the said area | region _RL of the film supported and conveyed by the support roll . The measurement of the height H is as follows:
A plurality of measurement value groups D obtained by measuring the height of the film surface in the film thickness direction at a plurality of measurement points distributed in alignment in the film width direction over a region WA having a predetermined width in the region _RH . _{Determining the} height H by calculation based on H,
The measurement of the height L is as follows:
In the region _RL , the height of the film surface in the film thickness direction is measured at a plurality of measurement points distributed in alignment in the film width direction over the region WB of a predetermined width, and a plurality of measurement value groups obtained and determining the height L by calculation based on the D _L, measuring method according to claim 13. Calculation based on the measurement value group D _H for determining the height H is, an average of the measurement value group D _H, and which is calculated according to the height H,
The height L based on the measurement value group D _L for obtaining the calculation, an average of the measurement value group D _L, a this calculation to the height L, the measuring method according to claim 14 . The number of measurement points in one area WA is _NH ,
The number of measurement points in one area WB is _NL ,
The height H is based on the measurement value group D _H for obtaining the calculation of the measured value group D _H, it calculates the average of the top X _H number of measurements, be calculated for this height H ,
The height L based on the measurement value group D _L for obtaining the calculation of the measured value group D _L, obtains the average of the top X _L pieces of measurement, be calculated for this height L ,
X _H is a number set within a range of 2 or more and N _H / 2 or less,
Wherein X _L is a number that is set in the range of 2 or more N _L, the measuring method according to claim 14.   The measurement position of the height H and the measurement position of the height L for obtaining one of the values of the difference (HL) are positions aligned in the film width direction. The measurement method according to any one of the above.   The measuring method according to claim 13, wherein the measuring instrument that measures the height H and the measuring instrument that measures the height L are the same device. The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, and the region WA The measurement method according to any one of claims 14 to 18, wherein a distance from the region WB is wider than a meandering width of the film to be conveyed. The region R _H , the region WA, and the region WB are band-like regions extending continuously in the longitudinal direction of the film, and the region WA and the region WB are separated in the width direction, and the region WA The measurement method according to any one of claims 14 to 19, wherein a distance from the region WB is narrower than an average of a width of the region WA and a width of the region WB.   The measurement method according to any one of claims 13 to 20, wherein the measurement is performed a plurality of times and the cycle is 0.1 second or less. The measurement method according to any one of claims 13 to 21, wherein the region _RH is a region of a film edge.

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