JP2016066076A - Fine concavo-convex-surfaced material and manufacturing method therefor - Google Patents

Abstract

When used as a light distribution controller, a wide FWHM is maintained while maintaining a wide FWHM in a wide light distribution direction (the direction that exhibits the widest light distribution characteristic when parallel light is incident on the light distribution controller). To provide fine surface irregularities having a certain degree of FWHM in a direction orthogonal to the light distribution direction.
A surface fine concavo-convex body in which fine concavo-convex is formed on at least a part of a surface, wherein the fine concavo-convex is between a plurality of ridges meandering non-parallel to each other and the plurality of ridges. It has a wavy uneven pattern having a groove, and has a plurality of recesses or protrusions formed on the wavy uneven pattern, and at least a part of the plurality of recesses or protrusions is an island-shaped collection region Surface fine irregularities present in
[Selection] Figure 1

Description

  The present invention relates to a surface fine uneven body having a light distribution control function and a method for producing the same.

  It is known that a sheet-like surface fine uneven body on which a concave / convex pattern composed of fine wavy unevenness is formed is used as a light distribution control body such as a light distribution control sheet because of its optical characteristics. .

  As a manufacturing method of a light distribution control sheet, for example, in Patent Document 1, a laminated sheet provided with a resin hard layer on a resin substrate made of a heat shrinkable film is heated to shrink the heat shrinkable film. Thus, there is disclosed a method of forming a concavo-convex pattern on the surface of a hard layer by deforming the hard layer so as to be folded into a concavo-convex shape.

Patent Document 1 describes that a concavo-convex pattern with small variation in orientation can be formed by stretching after shrinking a heat-shrinkable film. Such a sheet can be used as a light distribution control sheet.

JP 2011-213051 A

For projectors and displays used in TVs, computers, mobile phones, smartphones, in-vehicle display devices, etc., front illuminance and brightness due to excessive spreading of light in unnecessary directions in sheets with isotropic light distribution This is undesirable because it leads to a decrease in

Further, since the LED scanner light source of a copying machine or a scanner has LEDs arranged in a line, it is necessary to change the LED point light source to a linear light source in the LED arrangement direction. On the other hand, in the direction orthogonal to the LED arrangement direction, for example, a certain angle component may be directly irradiated on the reading surface of the apparatus, and another certain angle component may be reflected once and then irradiated on the reading surface of the apparatus. .
For the above reasons, when using a light distribution control sheet for the scanner light source, the LED array direction must have a wide light distribution, and a certain amount of light distribution is also required in the direction orthogonal to the LED array direction. It becomes. Even in such a case, a sheet having an isotropic light distribution is not desirable because it leads to a decrease in front illuminance due to excessive spreading of light in unnecessary directions.
Therefore, the present inventors tried to apply an elliptical light distribution control sheet instead of an isotropic light distribution.

It is considered that such a light distribution control sheet can be manufactured, for example, by using a biaxial heat-shrinkable film that heat-shrinks in the biaxial direction as a heat-shrinkable film and shrinking in the biaxial direction. However, in the method, it is difficult to control the manufacturing conditions, and it is difficult to stably obtain a light distribution control sheet having a certain performance.

  The present invention has been made in view of the above circumstances. When used as a light distribution control body, the present invention has a wide light distribution direction (the direction that exhibits the widest light distribution characteristic when parallel light is incident on the light distribution control body. The surface fine irregularities having a certain degree of FWHM (at least 4 °) in the direction orthogonal to the wide light distribution direction and maintaining the wide FWHM (at least 18 °), and the manufacture thereof Provide way

The present invention has the following aspects.
[1] A surface fine concavo-convex body in which fine concavo-convex is formed on at least a part of the surface, wherein the fine concavo-convex is a plurality of ridges meandering non-parallel to each other, and a recess between the ridges It has a wavy uneven pattern having a strip, and has a plurality of recesses or protrusions formed on the wavy uneven pattern, and at least a part of the plurality of recesses or protrusions is an island-shaped collection region Presence of surface fine irregularities.
[2] The surface fine concavo-convex body according to [1], wherein an average length of ridge lines of the plurality of ridges is 10 to 100 μm.
[3] In the wavy concavo-convex pattern, [1] or [2] includes a ridge that has a large deviation in the arrangement direction from the wide orientation distribution direction and whose parallelism is more disturbed than other ridges. The surface fine irregularities described.
[4] The surface fine concavo-convex body includes a FWHM (FWHM _Y ) in a direction Y in which light passing through the surface on which the fine concavo-convex is formed is most widely distributed, and a direction X orthogonal to the direction Y. The relationship with FWHM (FWHM _X ) satisfies the following formula (1), FWHM _X is 4 ° or more, and the Fourier transform image of the surface image of the fine unevenness is expressed as the Y direction and the Fourier transform image. When the rotation is performed so that the horizontal directions of the images coincide with each other, the shape of the white portion extending in the left-right direction from the center of the Fourier transform image after the rotation has a vertical position where the frequency peak is zero in the horizontal direction. When the distance exceeds a certain size, the distance from the zero point in the vertical direction increases, and the left and right shapes with respect to the zero point become coincident sword shapes when rotated 180 °. Specially To [1] surface fine irregularities according to any one of - [3].
FWHM _Y / FWHM _X ≧ 1.2 (1)
[5] The surface fine unevenness according to any one of [1] to [4], wherein an occupied area ratio of the concave portion or the convex portion in the fine unevenness is 30 to 70%.
[6] The mode pitch of the plurality of ridges is 3 to 20 μm, and the apparent mode diameter of the recesses or projections is 1 to 10 μm. Surface fine irregularities.
[7] The surface fine concavo-convex body according to any one of [1] to [6], wherein an average height of the ridges is 4 to 7 μm.
[8] A method for producing a surface fine unevenness, which produces the surface fine unevenness according to any one of [1] to [7],
A laminating step of forming a laminated sheet by providing a hard layer containing a matrix resin and particles dispersed in the matrix resin on at least one surface of the base film;
A deformation step of deforming at least the hard layer of the laminated sheet so as to be folded to form surface fine irregularities on at least one surface of the laminated sheet.
[9] The base film has a property of shrinking by heating, and the deforming step is to deform the hard layer by folding the base sheet by heating the laminated sheet. The method for producing a fine surface irregularity according to [8], which is a process.
[10] The glass transition temperature of the matrix resin is 10 ° C. or more higher than the glass transition temperature of the main component constituting the base film,
The surface fine concavo-convex body according to [9], wherein the particle is mainly composed of a material whose particle shape is not changed by heat at a temperature lower than 10 ° C. higher than the glass transition temperature of the main component constituting the base film. Manufacturing method.
[11] The method for producing a fine surface irregularity according to [8] to [10], wherein the particle size of the particles is larger than the thickness of the hard layer in the laminating step.
[12] A method for producing a surface fine unevenness, which produces the surface fine unevenness according to any one of [1] to [7],
A laminating step of forming a laminated sheet by providing a hard layer containing a matrix resin and particles dispersed in the matrix resin on at least one surface of the base film;
A deformation step of deforming at least the hard layer of the laminated sheet so as to fold, and forming surface fine irregularities on at least one side of the laminated sheet;
Using at least part of the surface fine irregularities obtained in the deformation step as a master,
The manufacturing method of the surface fine unevenness | corrugation which has the transfer process which transfers surface fine unevenness | corrugation.

  According to the present invention, when used as a light distribution control body, while maintaining a wide FWHM (at least 15 °) in the wide light distribution direction, a certain amount of FWHM is also obtained in the direction orthogonal to the wide light distribution direction. It is possible to provide a surface fine concavo-convex body having (at least 4 °) and easy to manufacture and a method for manufacturing the same.

It is the optical microscope photograph which observed the fine unevenness | corrugation of the surface fine unevenness | corrugation which is an example of embodiment of this invention. It is the other laser microscope photograph which observed the fine unevenness | corrugation of the surface fine unevenness | corrugation which is an example of embodiment of this invention. FIG. 2 is an enlarged longitudinal sectional view schematically showing a portion cut along a line I-I ′ in the optical micrograph of FIG. 1. It is a figure which shows the relationship between an illumination intensity curve, FWHM, and FWn ^th M. FIG. 2 is a Fourier transform image obtained by obtaining a gray scale image from the optical micrograph of the surface fine irregularities of FIG. 1 and Fourier transforming the image. 6 is an image obtained by rotating the Fourier transform image of FIG. 5 so that the wide light distribution direction is the horizontal direction. It is a schematic diagram which shows typically the Fourier-transform image of FIG. 7 is a graph in which a line L1-1 is drawn so as to pass through a point having the maximum frequency in A1 from the center of FIG. 6 and a frequency distribution of the line L1-1 is plotted. FIG. 7 is a graph in which a line L1-2 is drawn from the center of FIG. 6 in a direction orthogonal to L1-1 and a frequency distribution of the line L1-2 is plotted. The lines L2-1, -2, ... are drawn in parallel with the line L-2 in FIG. 6, and the positions indicating the respective frequency peaks are defined as the line L-1 and its extension line in the minus direction and the line L2-1. , −2... It is the longitudinal cross-sectional view of the principal part of the surface fine unevenness | corrugation body obtained from the observation result which observed the fine unevenness formation surface of the surface fine unevenness | corrugation body of FIG. 1 with the atomic force microscope. It is explanatory drawing of the method of calculating | requiring the average height of a protruding item | line part. It is explanatory drawing of the method of calculating | requiring the average height of a convex part. It is an image figure which shows the shape of the projection image of the emitted light at the time of using the conventional light distribution control sheet with high anisotropy. It is an image figure which shows the shape of the projection image of the emitted light at the time of using the surface fine unevenness | corrugation body by this invention. It is a longitudinal cross-sectional view of the original plate (surface fine uneven body) for manufacturing the surface fine uneven body of FIG. It is sectional drawing explaining the manufacturing method of the original plate (surface fine unevenness | corrugation body) of FIG.

Hereinafter, the present invention will be described in detail.
<Surface fine irregularities>
FIG. 1 shows a single-sided optical micrograph (plan view; vertical 0.8 mm × horizontal 1 mm) of a light distribution control sheet (light distribution control body) which is an embodiment of the surface fine irregularities of the present invention. FIG. 2 is a laser microscope photograph in which fine irregularities of the light distribution control sheet of Example 1 were observed with a laser microscope (“VK-8510” manufactured by Keyence Corporation). 1 and 2 are different in magnification.

  FIG. 3 is an enlarged vertical cross-sectional view schematically showing a portion cut along a line II ′ (a line along a direction in which a convex strip portion and a concave strip portion to be described later are repeated) in the optical micrograph of FIG. FIG. FIG. 3 shows a simplified view from the viewpoint of easy understanding of the vertical cross-sectional shape of the light distribution control sheet.

  In the present specification, the “surface fine uneven body” means an article having a fine uneven structure on the surface.

  The light distribution control sheet 10 (surface fine irregularities) of this example was provided on a transparent substrate 11 made of polyethylene terephthalate (PET) and one surface of the substrate 11 as shown in FIG. It has a two-layer structure with a transparent surface layer 12 made of a cured product of an ionizing radiation curable resin. On the surface on the exposed side of the surface layer 12, a wavy uneven pattern 13 and the uneven pattern 13 are formed. The fine unevenness | corrugation comprised from many formed convex parts 14 is formed. In this example, the convex portion 14 is formed in a substantially hemispherical shape. In this example, the exposed surface of the base material 11 (the surface on the side opposite to the side on which the surface layer 12 is provided) is a smooth surface.

  In addition, at least some of the plurality of convex portions 14 exist in a plurality of island-shaped aggregate regions. Furthermore, the protruding line part or the recessed line part includes one having an arrangement direction different from the wide orientation direction distribution.

  The wavy uneven pattern 13 in the fine unevenness extends in the longitudinal direction in FIG. 1, and in FIG. 3, a plurality of streak-shaped protruding portions 13a extending in a direction perpendicular to the paper surface, and the plurality of protruding portions 13a. The concave ridge portions 13b are alternately repeated in one direction (lateral direction in FIGS. 1 and 2).

As shown in FIG. 3, the vertical cross-sectional shape of each ridge 13 a is a tapered shape that becomes thinner from the proximal end side toward the distal end side.

  As shown in FIG. 1, each of the plurality of ridge portions 13 a meanders and is non-parallel to each other and is irregularly formed. That is, the ridge line meanders in each protruding line part 13a, and the valley line meanders in each recessed line part 13b. Further, the interval between the ridge lines of the adjacent ridge portions 13a is not constant, and the interval between the valley lines of the adjacent ridge portions 13b is not constant.

  In the present specification, the irregularity means that when the light distribution control sheet 10 is viewed from the normal direction with respect to the base material, the ridges 13a meander and are not parallel to each other. The ridges of the strips 13a meander, the valleys of each concave strip 13b meander, and the intervals between the ridges of the adjacent convex strips 13a are not constant, and the intervals between the valleys of the adjacent concave strips 13b Means that is not constant.

  Moreover, the height of the ridge line is not constant in each protruding line part 13a, and the height of the valley line is not fixed in each recessed line part 13b. Therefore, as shown in FIG. 3, the vertical cross-sectional shape of each protruding item | line part 13a is different, respectively, and is not uniform but irregular.

  The fine unevenness is composed of such a wave-like uneven pattern 13 and a large number of randomly distributed convex portions 14.

  Here, the ridgeline of the “ridge 13a” means a line that connects the tops of the ridges 13a.

  When the convex part 14 exists in the middle of the ridgeline of the convex part 13a, it refers to the line drawn so that the top part of the convex part 14 may be passed.

  As the substrate 11 shown in FIG. 3, in addition to PET having excellent mechanical strength and dimensional stability, a transparent material such as resin such as polycarbonate, polymethyl methacrylate, polyethylene acrylate, and polystyrene, and glass can be used. . The thickness of the base material 11 is 30-500 micrometers, for example.

  Examples of the surface layer 12 include a cured product of a thermosetting resin, a thermoplastic resin, and the like in addition to a cured product of an ionizing radiation curable resin. Examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin. The thickness of the surface layer 12 should just be sufficient thickness to form the wavy uneven | corrugated pattern 13, and it is preferable that the thickness of the thickest part is about 10-25 micrometers. The thickness of the surface layer 12 means a thickness before the surface layer 12 is deformed, and can be measured using an optical non-contact film thickness measuring instrument.

  Further, in this example, the fine unevenness of the light distribution control sheet 10 is composed of a wavy uneven pattern 13 and a large number of protrusions 14. However, the fine unevenness of the surface fine unevenness of the present invention is wavy. You may be comprised from the uneven | corrugated pattern and many recessed parts.

  In the light distribution control sheet 10, the repeating direction (horizontal direction in FIG. 1) of the wavy uneven pattern 13 may be referred to as direction Y, and the direction orthogonal to the direction Y (vertical direction in FIG. 1) may be referred to as direction X.

  In this specification, in this XY orthogonal coordinate system, the first direction may be referred to as the Y-axis direction and the second direction may be referred to as the X-axis direction. In addition, the direction orthogonal to the XY axis may be referred to as the third direction or the normal direction of the substrate of the surface fine unevenness.

  In the illustrated light distribution control sheet 10, the most frequent pitch of the wavy uneven pattern 13 is 3 to 20 μm from the viewpoint of exhibiting light distribution control performance. The most frequent pitch of the wavy uneven pattern 13 is preferably 7 to 15 μm, more preferably 11 to 13 μm. The pitch is the distance between the tops of adjacent ridges.

  When the most frequent pitch is within the above range, a surface on which fine irregularities are formed (hereinafter sometimes referred to as a fine irregularity forming surface) or a smooth surface side opposite to the surface with respect to the light distribution control sheet 10 When the light is incident from the side, the outgoing light from the surface opposite to the incident surface is well distributed in the direction Y (wide light distribution direction). That is, the direction Y is the wide light distribution direction.

In the illustrated orientation control sheet 10, it is desirable that the average length of the ridge lines of the ridges is 10 to 100 μm from the viewpoint of exhibiting light distribution control performance.
When the average length of the ridges of the ridges is within the above range, as will be described later, the parallelism of the ridges is moderately weakened, so that the light distribution can be easily controlled.

The FWHM (Full Width at Half Maximum, hereinafter also referred to as FWHM _Y ) in the direction Y is, for example, 15 ° or more, preferably 18 ° or more, more preferably 20 ° or more.
The relationship between FWn ^th M in the direction Y (Full Width at n Maximum, hereinafter also referred to as FWn ^th M _Y ) and FWHM _Y is FWn ^th M _Y ≦ FWHM _Y × (n × 0.027 + 1.133) + (N × 2.167 + 3.333), preferably FWn ^th M _Y ≦ FWHM _Y × (n × 0.027 + 1.133) + (n × 2 + 2), more preferably FWn ^th M _Y ≦ FWHM _Y × (N × 0.027 + 1.133) + (n × 2)) (4 ≦ n ≦ 10). The upper limit value of FWHM _Y is not particularly limited, but is, for example, 30 °.

  And the fine unevenness | corrugation of the light distribution control sheet 10 of the example of illustration has many convex parts formed in addition to the wavy uneven | corrugated pattern 13 mainly responsible for the light distribution in the wide light distribution direction as mentioned above. 14. Therefore, the anisotropy of the wavy uneven pattern 13 is moderately weakened by the protrusions 14. As a result, when light is incident on the light distribution control sheet 10 from one of the surfaces, the emitted light from the opposite surface is also distributed in the direction X (the direction orthogonal to the wide light distribution direction). Light is distributed, but the light distribution is smaller than the direction Y.

The FWHM in the direction X (hereinafter also referred to as FWHM _X ) is 4 ° or more, preferably 6 ° or more, more preferably 8 ° or more.
Further, FWHM _Y / FWHM _X ≧ 1.2, and preferably FWHM _Y / FWHM _X ≦ 5.

Furthermore, the relationship between FWn ^th M (also referred to as FWn ^th M _X ) in the direction X orthogonal to the wide light distribution direction Y and FWHM _X is FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1) 267) + (n × 0.667-2.667), preferably FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) + (n × 0.75-1.5), More preferably, FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) + (n × 0.833−0.333). Moreover, it is desirable to satisfy FWn ^th M _X ≦ FWHM _X × (n × 0.033 + 1.267) + (n × 2.5).
The upper limit value of FWHM _X is not particularly limited, but is 20 °, for example.

The apparent mode diameter of the convex portion 14 is preferably 1 to 10 μm, more preferably 3 to 6 μm, and still more preferably 4 to 5 μm.
When the apparent mode diameter of the convex portion 14 is within the above range, the anisotropy of the wavy uneven pattern 13 can be moderately weakened, and the FWHM in both the direction Y and the direction X can be easily controlled within the above range. For example, the direction Y is preferably 15 to 30 °, more preferably 18 to 25 °, and the direction X is preferably 4 to 20 °, more preferably 8 to 15 ° (however, FWHM _Y > FWHM _X ). .

Further, the FWn ^th M in both the direction Y and the direction X can be easily controlled within the above range. For example, the direction Y is preferably FWn ^th M _Y ≦ FWHM _Y × (n × 0.027 + 1.133) + n × 2. 167 + 3.333) and the direction X is preferably easy to control, FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) + (n × 0.667-2.667).

FWHM and FWn ^th M in this specification can be measured by the following method using a light distribution characteristic measurement device (for example, GENESISA GonioFar Field Profile (manufactured by Genesia)).

First, light is irradiated and incident on the light distribution control sheet 10 from the smooth surface side opposite to the fine unevenness forming surface. At this time, the illuminance of the outgoing light (light outgoing angle = 0 °) emitted perpendicularly from the side opposite to the incident surface is used as the reference value, and the outgoing light within the range of the light outgoing angle along the direction Y of −90 ° to + 90 °. Is measured at intervals of 1 ° as a relative value with respect to the reference value. Then, the illuminance value (FIG. 4) is obtained by plotting the illuminance value with respect to the light emission angle in each direction Y.

The half value width (full half value width) in the illuminance curve is defined as FWHM in the wide light distribution direction (direction Y). Further, the 1 / n value width (total 1 / n value width, where 4 ≦ n ≦ 10) is defined as FWn ^th M in the wide light distribution direction (direction Y) (FIG. 4).

Similarly, the illuminance of the outgoing light within the range of the outgoing light angle −90 ° to + 90 ° along the direction X is measured every 1 ° as a relative value with respect to the reference value. Then, the illuminance value is obtained by plotting the illuminance value with respect to the light emission angle in each direction X. The full width at half maximum (full width at half maximum) in the illuminance curve is defined as FWHM in the direction (direction X) orthogonal to the wide light distribution direction. Further, the 1 / n value width (total 1 / n value width) is defined as FWn ^th M in the direction (direction X) orthogonal to the wide light distribution direction.

  In the present specification, the mode pitch of the wavy uneven pattern 13 and the apparent mode diameter of the convex portion 14 are measured and defined as follows.

First, an optical micrograph as shown in FIG. 1 is obtained for the fine surface irregularities. The observation visual field in that case shall be 0.4-1.6 mm long and 0.5-2 mm wide. If this image is a compressed image such as jpeg, it is converted into a grayscale Tif image. Then, Fourier transform is performed to obtain a Fourier transform image as shown in FIG.
If the horizontal direction of the Fourier transform image in FIG. 5 and the wide light distribution direction do not match, the Fourier transform image is rotated so that both companies match to obtain FIG.

  Moreover, the schematic diagram of the Fourier-transform image of FIG. 6 is shown as FIG.

  Here, the white portions denoted by reference signs A1 and A2 in FIG. 6 include information on the pitch of the wavy uneven pattern since the shape thereof has directionality. White brightness indicates frequency (except for the center point). On the other hand, since the shape of the white circular ring B in FIG. 6 is not directional, it includes information on the diameters of a large number of convex portions.

  Therefore, when the line L1-1 is drawn from the center of FIG. 6 so as to pass through the point having the maximum frequency in A1, the frequency distribution of the line L1-1, in other words, the luminance is plotted, the graph of FIG. 8 is obtained. .

Further, when a line L1-2 is drawn from the center of FIG. 6 in a direction orthogonal to L1-1 and the frequency distribution of the line L1-2 is plotted, the graph of FIG. 9 is obtained.
The broken lines in FIG. 8 and FIG. 9 are frequency curves in the case where there is no high frequency portion such as X _A , X _B and Y _B.

  In FIG. 8, 1 / XA having a high frequency is the most frequent pitch of the wavy uneven pattern in the light distribution control sheet 10.

  In FIGS. 8 and 9, 1 / XB and 1 / YB having a high frequency are the mode diameters in the L1-1 direction and the L1-2 direction, respectively, of a large number of convex portions in the light distribution control sheet 10. That is, 1 / XA is the mode pitch of the wavy uneven pattern, and (1 / XB + 1 / YB) / 2 is the apparent mode diameter of a number of convex portions.

  In the Fourier transform image of FIG. 6, the orientation from the center means the direction of the periodic structure (uneven pattern 13) existing in FIG. 1, and the distance from the center is the period of the periodic structure existing in FIG. Means the reciprocal. In this example, as shown in FIG. 1, since the wavy uneven pattern 13 is repeated in the horizontal direction in the figure, the most frequent pitch in the line L <b> 1-1 extending in the horizontal direction in the figure from the center in the Fourier transform image. The luminance (frequency) of the portion corresponding to the reciprocal of is high.

  In FIG. 7, XB is a position where the frequency is maximum in a portion passing through the ring of line L1-1 (not shown in FIG. 7), and in FIG. 7, YB is a line L1-2. This is the position where the frequency is maximum in the portion passing through the ring (not shown in FIG. 7).

  At least five optical micrographs as shown in the figure are taken, and the average value of the mode pitches obtained as described above for each photo is defined as the “mode pitch” of the wavy uneven pattern 13. That is, the “most frequent pitch” refers to the distance between the tops having the highest appearance frequency among the distances between the tops of the adjacent ridges. Further, the average value of the apparent mode diameter obtained as described above for each photograph is defined as the “apparent mode diameter” of the convex portion 14. That is, the “apparent mode diameter” refers to a diameter having the highest appearance frequency among the diameters of the convex portions formed on the concave / convex pattern.

  The fine irregularities of the surface fine irregularities may have concave portions instead of convex portions, and the “apparent mode diameter” of the concave portions is the same as the “apparent mode diameter” of the convex portions. Desired.

  In the present specification, the average length of the ridge line of the ridge is measured and defined as follows.

  First, an optical micrograph as shown in FIG. 1 is obtained for the fine surface irregularities. The observation visual field in that case shall be 0.4-1.6 mm long and 0.5-2 mm wide. And all the lengths of the ridgeline of the said optical micrograph are measured. At least five optical micrographs as shown in FIG. 1 are taken, and the average value of the lengths of the ridges of the ridges obtained as described above for each photo is defined as “average length of the ridges”.

  10 draws lines L2-1, -2,... (Not shown in FIG. 6, not shown in FIG. 7) parallel to the line L1-2 in FIG. Is a graph in which the positions M1, M2,... Showing the respective frequency peaks on the lines L2-1, -2,. is there. Here, the frequency peak is the peak on the X axis when the peak exists only on the X axis, and the peak other than on the X axis when the peak exists on other than the X axis. That is.

  The plot in FIG. 10 preferably has a sword shape as shown in the schematic diagram 7. Here, the sword-like shape means that the frequency peak position of the lines L2-1, -2, ... in FIG. 6 depends on the distance between the zero point and the lines L2-1, -2, .... In other words, when the distance between the two exceeds a certain size, the distance from the zero point in the vertical direction increases. In such a shape, the left and right shapes with respect to the zero point coincide with each other when rotated by 180 °.

The fact that FIG. 10 becomes a plot as described above means that a periodic structure having a large reciprocal number of the period, that is, a convex line having a smaller pitch, the alignment direction is shifted from the wide light distribution direction. For this reason, the surface fine irregularities of the present embodiment, since the protrusions 14 have island-shaped gathering regions, as described later, the smaller the pitch, the more easily affected by the island-like gathering regions, It seems that the parallelism with other ridges is greatly disturbed during formation.
The light distribution in the wide light distribution direction of the surface fine irregularities of the present embodiment is caused by the light being refracted mainly by the convex portions (or concave portions) and the ridges, and the direction perpendicular to the wide light distribution direction. The light distribution to the light occurs when light is refracted mainly by the convex part (or concave part).
As will be described later, since the ridge is formed by deformation of the hard layer due to shrinkage of the heat-shrinkable film, the cross-sectional shape thereof is random in pitch and height, and light distribution can be easily controlled. On the other hand, since the convex part (or concave part) is formed by mixing particles in the hard layer, the cross-sectional shape is a part of a circle, and the control of light distribution is more difficult than using a convex line.
Although it is possible to control the light distribution in two directions orthogonal to each other by shrinkage of the biaxially shrinkable heat-shrinkable film, it is difficult to control the manufacturing conditions as described above, and the light distribution control has a certain performance. It is difficult to obtain a stable sheet.
As described above, if the ridges with a small pitch are oriented in a direction deviating from the wide light distribution direction, the ridges also affect the light distribution in the direction orthogonal to the wide light distribution direction. Therefore, as a result, the light refraction randomness in the direction orthogonal to the wide light distribution direction increases, and the light distribution can be easily controlled.

In FIG. 10, P1 is the distance from the line L2-G to the zero point where the distance from the zero point is the maximum among the lines L2-1, -2,. , P2 has no on the X-axis position of the peak frequency, and on the X-axis, the line from the line L2-J containing 1/3 to become a point M _J peak next to the peak containing the zero point L2- distance to G, P3 is the distance from _{M J} to the X-axis.
At this time, if P1> P2 and P3> P1, the light distribution control performance of the FWHM and FWn ^th M in the wide light distribution direction and the direction orthogonal to the wide light distribution direction can be sufficiently obtained. That is, if P1> P2 and P3> P1, the parallelism of the ridges is moderately disturbed, and anisotropy can be moderately weakened.

  4-7 micrometers is preferable and, as for the average height of the protruding item | line part 13a which comprises the wavy uneven | corrugated pattern 13, 5-6 micrometers is more preferable. Light distribution control performance is sufficiently obtained when the average height of the ridges 13a is in the above range.

  In the present specification, the average height of the ridges 13a of the wavy uneven pattern 13 is measured and defined as follows.

  First, the surface with fine irregularities formed on the light distribution control sheet 10 is observed with an atomic force microscope, and from the observation result, the longitudinal sectional view as shown in FIG. Get. And the height H of the said protruding item | line part 13 is calculated | required from sectional drawing of the protruding item | line part 13a of the part in which the protruding part 14 does not exist. Specifically, the height H of the ridge portion 13a is set to H1 as a vertical distance between the top portion T of the ridge portion 13a and the bottom portion B1 of the ridge portion 13b located on one side of the ridge portion 13a. When the vertical distance between the top portion T of the ridge portion 13a and the bottom portion B2 of the ridge portion 13b located on the other side of the ridge portion 13a is defined as H2, H = (H1 + H2) / 2.

  Such measurement is performed on 50 portions of the ridge portion 13a where the ridge portion 14 does not exist, and the average value of the 50 data is defined as “average height of the ridge portion”.

  On the other hand, the average height of the convex portion 14 is preferably 0.5 to 3 μm, more preferably 1 to 2 μm, and still more preferably 1.1 to 1.5 μm. When the average height of the protrusions 14 is in the above range, the anisotropy of the wavy uneven pattern 13 can be moderately weakened, and the FWHM in both the direction Y and the direction X can be easily controlled in the above range.

  In this specification, the average height of the convex part 14 is measured and defined as follows.

First, the cross-sectional view of FIG. 11 is obtained as described above. Then, as shown in FIG. 12, the waveform is separated into a shape derived from the wavy uneven pattern 13 and a shape derived from the convex portion 14. The waveform separation is performed using a shape derived from the wavy uneven pattern 13 as a sine curve. Next, the shape derived from the wavy uneven pattern 13 is subtracted from the cross-sectional view of FIG. 12 to obtain a cross-sectional view of only the shape derived from the convex portion 14 as shown in FIG. Then, in the cross-sectional view of FIG. 13, the height H ′ of the convex portion 14 is obtained as H ′ = (H1 ′ + H2 ′) / 2. In the cross-sectional view of FIG. 13, H1 ′ is a vertical distance between the top portion T ′ of the convex portion 14 and the base line L _α on one side of the convex portion 14, and H2 ′ is the top portion T ′ of the convex portion 14. it is a vertical distance between the baseline L _beta of the other side of the convex portion 14.

  Such measurement is performed on 50 convex portions 14, and the average value of 50 data is defined as "average height of convex portions".

  The occupied area ratio of the convex portions 14 (or concave portions in the light distribution control sheet 10 which are concave portions but not shown in the drawing because they are not shown in the drawing, the same applies hereinafter) is 30 to 70%. Preferably, it is 40 to 60%, more preferably 45 to 55%. When the occupation area ratio of the convex portion 14 is within the above range, the anisotropy of the wavy uneven pattern 13 can be moderately weakened, and the FWHM in both the direction Y and the direction X can be easily controlled within the above range.

  In this specification, the occupation area ratio γ (%) of the convex portion 14 in the light distribution control sheet 10 is measured and defined as follows.

First, an optical micrograph as shown in FIG. 1A is obtained, and the number n of convex portions 14 recognized in the area S2 of the entire visual field (for example, 0.4 to 1.6 mm in length and 0.5 to 2 mm in width). And the area S1 = nr ² π occupied by the n convex portions 14 in the entire field of view is obtained. The occupied area ratio γ (%) is obtained by the following formula.

  γ (%) = S1 × 100 / S2 (where r is half the apparent mode diameter of the convex portion (ie, radius)) Needless to say, the light distribution control sheet The above occupied area ratio is obtained at a plurality of locations, and the occupied area ratio with respect to the entire area where the fine unevenness of the light distribution control sheet exists is obtained.

  As described above, the light distribution control sheet 10 in the illustrated example is formed on one surface of the specific wavy uneven pattern 13 mainly responsible for light distribution in the direction Y, and the wavy uneven pattern 13. The uneven pattern 13 has fine unevenness composed of a large number of convex portions 14 that moderately weaken the anisotropy and increase the light distribution in the direction X.

Therefore, when light is incident on the light distribution control sheet 10 from any one surface, a sufficient FWHM _{Y of} , for example, 15 ° or more, preferably 18 ° or more, more preferably 20 ° or more is obtained in the direction _Y. . Further, FWn ^th M _Y ≦ FWHM _Y × (n × 0.027 + 1.133) + (n × 2.167 + 3.333), preferably FWn ^th M _Y ≦ FWHM _Y × (n × 0.027 + 1. 133) + (n × 2 + 2), more ^{_{preferably, FWn th M Y ≦ FWHM Y}} × (n × 0.027 + 1.133) + (n × 2), the ^FWN th _{M Y} satisfying obtained. On the other hand, FWHM _{X of} 4 ° or more, preferably 6 ° or more, more preferably 8 ° or more is also obtained in the direction X.

Further, FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) + (n × 0.667-2.667), preferably FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) ) + (n × 0.75-1.5), more preferably _{^{FWn th M X ≧ FWHM X ×}} (n × 0.033 + 1.267) + (n × 0.833-0.333) satisfies the ^{FWN th} M is obtained. When a conventional light distribution control sheet having high anisotropy is used, the emitted light is distributed in the direction Y, but hardly distributed in the direction X. Therefore, the projected image of the emitted light is as shown in FIG. The oval shape has a large aspect ratio. On the other hand, when the light distribution control sheet 10 of the illustrated example is used, the emitted light is also distributed in the direction X, so that the projected image of the emitted light has an elliptical shape with a small flatness as shown in FIG. Become.

The light distribution, that is, the viewing angle of the projector or the display has a high correlation with the FWHM, and when the FWHM increases, the viewing angle widens, but on the other hand, the front luminance and the front illuminance decrease. For this reason, for example, in the case of a projector or display that requires different viewing angles in the X direction and the Y direction orthogonal to the X direction, the decrease in front luminance and front illuminance can be minimized by controlling each FWHM individually. Can be suppressed.
FWn ^th M, like FWHM, has a correlation with viewing angle, front luminance, and front illuminance. However, white light emitting diodes are used for projectors and displays, and light emitted from the white light emitting diodes is collected by a condenser lens. In this case, when the light emitted from the condenser lens is projected onto white paper or the like, a phenomenon in which the hue is different between the central portion and the outer peripheral portion of the projected image may be observed. It is effective to increase FWn ^th M in order to return the color to uniform white.

When it is desired to set the FWHM of the light emitted from the condenser lens to u ° in the Y direction and v ° in the X direction perpendicular to that direction (where there is anisotropy such as u / v ≧ 1.2), FWHM There relatively at sufficiently large Y-direction ^FWN th _{M y} be sufficiently large, the in Y-direction, it is less shade difference is a problem, the FWHM is relatively small ^{X-direction, FWN} th _{M X} Is not large enough to satisfy FWn ^th M _X ≧ FWHM _X × (n × 0.033 + 1.267) + (n × 0.667-2.667), it becomes difficult to eliminate the difference in hue.
n preferably satisfies 4 ≦ n ≦ 10. If n is larger than 10, the illuminance curve in the illuminance curve is too small and the measurement error becomes large. If n is smaller than 4, the same tendency as FWHM is shown, which is not preferable as an index.
Since the LED scanner light source of copiers and scanners has a linear array of LEDs, it is necessary to convert the LED point light source into a linear light source, and the direction orthogonal to the LED array direction is: For example, there is a case where a certain angle component is directly applied to the reading surface of the apparatus and another angle component is reflected once and then irradiated to the reading surface of the apparatus. The LED arrangement direction requires a wide light distribution, and a certain amount of light distribution is also required in the direction orthogonal to the LED arrangement direction.

  Further, the ridges 13a constituting the wavy uneven pattern 13 of the light distribution control sheet 10 in the illustrated example are non-parallel to each other and meandering, and have no regularity. In particular, since the projecting portions are formed and island-shaped gathering regions exist, the arrangement direction of the projecting ridge portions or the recessed ridge portions having a small pitch is deviated from the wide orientation distribution direction. Therefore, the anisotropy of the concavo-convex pattern 13 is moderately weakened, and it is considered that the effect of increasing the FWHM in the direction X appears more remarkably together with the effect of the convex portion 14 being formed. .

  As a method of increasing the FWHM in the direction X, a method of adding high refractive index particles or the like is also conceivable.

  However, the addition of high refractive index particles or the like tends to lower the light transmittance of the light distribution control sheet. On the other hand, in the method of increasing the FWHM in the direction X by specifically controlling the fine irregularities as in the present invention, it is not necessary to add high refractive index particles or the like, and even when added, the addition The amount can be small. Therefore, the light transmittance can be maintained high.

  The illustrated light distribution control sheet 10 includes, for example, a light distribution control member for a projector; backlight light distribution control for a television, a monitor, a notebook personal computer, a tablet personal computer, a smartphone, a mobile phone, and the like. It is also suitably used as a member.

  The light distribution control sheet 10 is also preferably used as a light distribution control member that constitutes the exit surface of the light guide member in a scanner light source in which LED light sources are arranged in a line, used in a copying machine or the like. The

  One aspect of the present invention is the use of the above-described surface fine unevenness as a light distribution control sheet or a light distribution control member, or a method of using the same. In addition, when the fine surface irregularities of the present invention are used as a light distribution control sheet or a light distribution control member, the application destination thereof is as described above for projectors, backlights for personal computers, mobile phones, etc. Examples include a light distribution control member such as an emission surface of the optical member.

<Method for producing surface fine unevenness>
The light distribution control sheet 10 (surface fine uneven body) in the illustrated example uses a light distribution control sheet forming original plate (light distribution control body forming original plate) having fine unevenness on the surface as a mold. It can be produced by a method having a transfer step of transferring fine irregularities of an original plate (hereinafter also referred to as “original plate”).

  One aspect of the present invention is the use of the surface fine concavo-convex body as a light distribution control sheet or an original plate for producing a light distribution control member.

  The light distribution control sheet 10 in the illustrated example is a secondary transfer product obtained by transferring the fine irregularities of the original plate to obtain a primary transfer product, and then further transferring the fine irregularities of the primary transfer product. The fine unevenness of the primary transfer product is a reverse pattern of the fine unevenness of the original plate, but the fine unevenness of the secondary transfer product is the same pattern as the fine unevenness of the original plate. Therefore, in this example, a surface fine uneven body having the same fine unevenness as the light distribution control sheet 10 in the illustrated example is manufactured as an original plate, and this is used as a transfer mold to perform secondary transfer, and the light distribution control sheet 10 in the illustrated example. Is manufacturing.

  Further, in the n-order transfer product, when n is an even number, the fine unevenness of the transfer product is the same pattern as the fine unevenness of the original plate, but when n is an odd number, the transfer product has The fine unevenness becomes a reversal pattern of the fine unevenness of the original. And, when n is an n-order transfer product having an odd number and the fine unevenness of the original used for transfer has a convex part, the fine unevenness of the n-order transfer product (n is an odd number) The convex part has a concave part that is inverted. As already described, the fine irregularities of the surface fine irregularities of the present invention may be in the form of having concave portions instead of convex portions. Therefore, the surface fine irregularities of the present invention include not only the above-mentioned original plate and the original n-order transfer product (n is an even number) but also the original n-order transfer product (n is an odd number).

  Hereinafter, a manufacturing method of the light distribution control sheet 10 of the illustrated example which is a secondary transfer product will be described.

[Original version]
In manufacturing the light distribution control sheet 10 of the illustrated example, first, the surface fine uneven body 20 shown in FIG. 16 is manufactured and used as an original. The original plate has a base material 21 made of resin and a hard layer 22 provided on one entire surface of the base material 21, and the exposed surface of the hard layer 22 has a light distribution control sheet 10 in the illustrated example. Are formed in the same fine irregularities.

  In this example, the hard layer 22 includes a matrix resin 22a and particles 22b dispersed in the matrix resin 22a. The hard layer 22 is deformed so as to be folded, and the thickness t of the hard layer 22 (part where no particles exist). Is set smaller than the particle diameter d of the particles. Therefore, the hard layer 22 has a wavy uneven pattern 13 ′ (projection strip portion 13 a ′ and recess strip portion 13 b ′) formed by being deformed as folded, and each particle 22 b dispersed in the hard layer 22. Has a fine asperity composed of a convex portion 14 ′ formed by projecting to the surface side of the hard layer 22. The contact surface of the base material 21 with the hard layer 22 has a concavo-convex shape following the shape of the hard layer 22 deformed as if folded.

  Note that the thickness t of the hard layer 22 is a portion of the hard layer 22 where the particles 22b are not present from a micrograph of a cross section (longitudinal cross section) obtained by cutting the surface fine irregularities 20 perpendicular to the surface direction. This is the average value of the numerical values obtained when randomly extracting more than one point and measuring the thickness of each part in the normal direction.

  The particle diameter d of the particles 22b is a mode diameter (mode) measured by a laser diffraction / scattering particle size distribution analyzer for particles that are uniformly monodispersed.

  As described in detail later, the surface fine concavo-convex body 20 in FIG. 16 is a lamination step in which a hard layer in which particles are dispersed in a matrix resin is provided on one side of a base film made of resin to form a laminated sheet. And a deformation step of deforming at least a hard layer of the laminated sheet so as to be folded. According to this method, it is possible to form meandering portions 13 a ′ which meander each other and are not parallel to each other and irregular. Further, the vertical cross section of each protruding line portion 13a 'is tapered from the proximal end side toward the distal end side.

  In the surface fine uneven body 20 of FIG. 16, the glass transition temperature Tg2 of the matrix resin 22a needs to be 10 ° C. or more higher than the glass transition temperature Tg1 of the resin constituting the substrate 21. Further, the particles 22b need to be made of a material whose particle shape does not change due to heat at a temperature lower than a temperature 10 ° C. higher than the glass transition temperature of the resin constituting the substrate 21.

  Here, “the particle shape does not change” means that the particle shape and particle diameter do not change before and after heating.

  That is, the resin constituting the base material 21 and the matrix resin 22a need to be selected so that the difference between these glass transition temperatures (Tg2−Tg1) is 10 ° C. or more. 20 degreeC or more is preferable and 30 degreeC or more is more preferable. When (Tg2−Tg1) is 10 ° C. or higher, processing such as heat shrinkage can be easily performed in a deformation step described later at a temperature between Tg2 and Tg1. Further, if the temperature between Tg2 and Tg1 is the processing temperature, it can be processed under the condition that the Young's modulus of the base material is higher than the Young's modulus of the matrix resin 22a. As a result, in the deformation process described later, the hard layer 22 is wavy. The uneven pattern 13 ′ can be easily formed. The processing temperature is a temperature at which the hard layer 22 is deformed so as to be folded at least in the deformation process (for example, a heating temperature at the time of thermal contraction).

  Further, the necessity of using a resin having a Tg2 exceeding 400 ° C. is scarce from an economic viewpoint, and there is no resin having a Tg1 lower than −150 ° C. Therefore, (Tg2−Tg1) is preferably 550 ° C. or less. More preferably, it is 200 ° C. or lower. That is, in one embodiment of the present invention, (Tg2-Tg1) is preferably 10 to 550 ° C, more preferably 30 to 200 ° C. Note that the difference in Young's modulus between the base material 21 and the matrix resin 22a at the processing temperature in the deformation process described later is preferably 0.01 to 300 GPa because the wavy uneven pattern 13 ′ can be easily formed. More preferably, it is 1-10 GPa.

  The Young's modulus is a value measured according to JIS K 7113-1995.

  Tg1 is preferably −150 to 300 ° C., more preferably −120 to 200 ° C. There is no resin having a Tg1 lower than −150 ° C., and if the Tg1 is 300 ° C. or lower, the temperature can be easily raised and heated to the above processing temperature.

  The Young's modulus of the resin constituting the base material 21 at the above processing temperature is preferably 0.01 to 100 MPa, and more preferably 0.1 to 10 MPa. If the Young's modulus of the resin constituting the base material 21 is 0.01 MPa or more, it is a hardness that can be used as the base material, and if it is 100 MPa or less, the hard layer 22 is deformed following the deformation at the same time. It is possible softness.

  As the material constituting the particles 22b, at least one kind of material whose particle shape does not change by heat can be used at a temperature lower than 10 ° C. higher than the glass transition temperature of the resin constituting the substrate 21.

  For example, when the material constituting the particles 22b is at least one selected from the group consisting of a resin having a glass transition temperature and an inorganic material having a glass transition temperature, the glass transition temperature Tg3 is the glass transition temperature of the matrix resin. It is necessary to satisfy the same conditions as Tg2, that is, (Tg3-Tg1) should be selected to be 10 ° C. or higher, and (Tg3-Tg1) is more preferably 20 ° C. or higher, and 30 ° C. or higher. Further preferred. When (Tg3−Tg1) is 10 ° C. or higher, the convex portion 14 ′ is surely formed without the particles 22 b being deformed and melted at the above processing temperature.

  When the material constituting the particles 22b is a material that does not have a glass transition temperature, such as an internally cross-linked resin, the Vicat softening temperature (as defined in JIS K7206) satisfies the above-described condition, that is, It is preferably higher than the glass transition temperature of the resin constituting the substrate 21 by 10 ° C. or higher, preferably higher by 20 ° C. or higher, more preferably higher by 30 ° C. or higher.

  In addition, in this specification, description of the preferable temperature range etc. about glass transition temperature Tg3 corresponds also to the Vicat softening temperature, when the particle | grains 22b consist of a material which does not have a glass transition temperature but has a Vicat softening temperature. Shall.

  Further, as the material constituting the particles 22b, even if the glass transition temperature and the Vicat softening temperature cannot be measured, the particles are heated by heat at a temperature lower than 10 ° C. higher than the glass transition temperature Tg1 of the resin constituting the base material 21. Any material that does not change shape can be used in the present invention.

  Tg2 and Tg3 are preferably 40 to 400 ° C, and more preferably 80 to 250 ° C. If Tg2 and Tg3 are 40 ° C. or higher, the above-described processing temperature can be increased to room temperature or higher, which is useful. Use of the particles 22b is less necessary from the viewpoint of economy.

  The Young's modulus of the matrix resin 22a at the above processing temperature is preferably 0.01 to 300 GPa, and more preferably 0.1 to 10 GPa. If the Young's modulus of the matrix resin 22a is 0.01 GPa or more, sufficient hardness is obtained from the Young's modulus at the processing temperature of the resin constituting the substrate 21, and after the wavy uneven pattern 13 'is formed, The hardness is sufficient to maintain the uneven pattern 13 ′. Use of a resin having a Young's modulus exceeding 300 GPa as the matrix resin 22a is less necessary from the viewpoint of economy.

  Examples of the resin constituting the substrate 21 include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, polystyrene resins such as styrene-butadiene block copolymers, polyvinyl chloride, polyvinylidene chloride, and polydimethylsiloxane. Examples thereof include resins such as silicone resin, fluororesin, ABS resin, polyamide, acrylic resin, polycarbonate, and polycycloolefin.

  Among these, polyester and polycarbonate are preferable because a desired uneven shape can be easily obtained after shrinkage.

  The resin preferably has a mass average molecular weight of 1,000 to 1,000,000. 10,000 to 100,000 are more preferable. The mass average molecular weight refers to a value measured using gel permeation chromatography. As specific measurement conditions, as the eluent, one appropriately selected from tetrahydrofuran, chloroform, hexafluoroisopropanol and the like can be used. Further, as the molecular weight standard substance, a material appropriately selected from known molecular weight polystyrene, polymethyl methacrylate and the like can be used. Moreover, as measurement temperature, it can select suitably in the range of 35-50 degreeC.

  The matrix resin 22a is selected according to the type of the base material 21 so that the glass transition temperature Tg2 satisfies the above-mentioned conditions. For example, polyvinyl alcohol, polystyrene, acrylic resin, styrene-acrylic copolymer, styrene -Acrylonitrile copolymer, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, fluororesin, etc. can be used. Among these, acrylic resins are preferable in terms of transparency.

  The matrix resin preferably has a mass average molecular weight of 1,000 to 10,000,000, more preferably 10,000 to 2,000,000. The mass average molecular weight refers to a value measured using gel permeation chromatography. As specific measurement conditions, as the eluent, one appropriately selected from tetrahydrofuran, chloroform, hexafluoroisopropanol and the like can be used. Further, as the molecular weight standard substance, a material appropriately selected from known molecular weight polystyrene, polymethyl methacrylate and the like can be used. Moreover, as measurement temperature, it can select suitably in the range of 35-50 degreeC.

  The matrix resin 22a may be used alone, but may be appropriately used in accordance with the purpose of adjusting the mode pitch, average height, and orientation degree of the wavy uneven pattern. For example, resins of the same type but different in glass transition temperature can be used in combination, or different types of resins can be used in combination.

  The resin constituting the particles 22b is selected according to the type of the base material 21 so that the glass transition temperature Tg3 (or Vicat softening point) satisfies the above-described conditions, for example, acrylic thermoplastic resin particles, Examples thereof include polystyrene-based thermoplastic resin particles, acrylic-based crosslinked resin particles, and polystyrene-based crosslinked resin particles. Examples of the inorganic material include glass beads.

  The thickness of the substrate 21 is preferably 30 to 500 μm. If the thickness of the base material is 30 μm or more, the manufactured original plate is hardly broken, and if the thickness is 500 μm or less, the original plate can be easily thinned. In addition, the thickness of the base material 21 is randomly extracted from a microphotograph of a cross section (longitudinal section) obtained by cutting the surface fine irregularities (original plate) 20 in FIG. It is an average value of the obtained numerical values when the thickness of the substrate 21 is measured.

  Moreover, in order to support the base material 21, you may provide separately the resin-made support bodies of thickness 5-500 micrometers.

  The thickness t of the hard layer 22 is preferably more than 0.05 μm and not more than 5 μm, and more preferably 0.1 to 2 μm. If the thickness t of the hard layer 22 is more than 0.05 μm and not more than 5 μm, a wavy uneven pattern 13 ′ suitable as a light distribution control body can be formed. Moreover, you may form a primer layer between the base material 21 and the hard layer 22 for the purpose of improving adhesiveness or forming a finer structure.

  The particle diameter d of the particles 22b needs to be larger than the thickness t of the hard layer 22, and is set according to the thickness t of the hard layer 22. 16 is appropriately set so that the apparent mode diameter of the convex portion 14 of the light distribution control sheet 10 in the illustrated example manufactured using the surface fine uneven body 20 of FIG. 16 is within the above-mentioned preferable range. Is done. The preferable particle diameter d is, for example, 5 to 10 μm, and more preferably 5 to 8 μm.

  In addition, the surface fine uneven | corrugated body 20 of FIG. 16 can also be used as a light distribution control body instead of an original plate. In that case, a transparent material is used for the material used for the base material 21, the matrix resin 22 a, and the particles 22 b so that the surface fine uneven body 20 sufficiently functions as a light distribution control body.

[Original plate manufacturing method]
16 has a laminated sheet 30 as shown in FIG. 17, that is, a matrix resin on one surface (flat surface) of a base film 31 made of resin, and particles 22b dispersed in the matrix resin. A laminating step of forming a laminated sheet 30 provided with a hard layer 32 having a thickness of more than 0.05 μm and not more than 5.0 μm, and a deformation step of deforming at least the hard layer 32 of the laminated sheet 30 so as to be folded. It can be manufactured by the method of having. Here, the substrate film 31 corresponds to the substrate 21 of the surface fine irregularities 20 of FIG. Here, the term “flat” refers to a surface having a center line average roughness of 0.1 μm or less as described in JIS B0601.

(Lamination process)
In the laminating step, first, a coating liquid (dispersion or solution) containing matrix resin 22a, particles 22b, and a solvent is prepared, and the coating liquid is applied to one surface of the base film 31 by a spin coater or a bar coater. As shown in FIG. 17, the hard layer 32 having a thickness t ′ of more than 0.05 μm and 5.0 μm or less is formed. The hard layer 32 at this time is not deformed so as to be folded.

  Instead of providing the coating liquid directly on the base film 31 as described above, the hard layer 32 is obtained by laminating a hard layer (a film in which particles are dispersed in a matrix resin) prepared in advance on the base film. You may provide by the method to do.

  The base film 31 is preferably a uniaxial heat shrinkable film made of resin. When the uniaxial heat-shrinkable film is used, by heating the laminated sheet 30 in the next deformation step, the hard layer 32 can be easily deformed so as to be folded and the wavy uneven pattern 13 ′ can be formed. Further, according to this method, it is possible to form irregular ridges 13a 'that meander each other and are not parallel to each other.

  The resin constituting the uniaxial heat-shrinkable film is as already exemplified as the resin constituting the base material 21. Specifically, a shrink film such as a polyethylene terephthalate shrink film, a polystyrene shrink film, a polyolefin shrink film, or a polyvinyl chloride shrink film can be preferably used.

  Among these shrink films, those that shrink 50 to 70% in the uniaxial direction are preferable. If a shrink film that shrinks by 50 to 70% is used, the deformation rate can be increased to 50% or more. As a result, it is possible to form a wavy uneven pattern 13 'having a suitable mode pitch and a height of the protruding portion 13a'.

  Here, the deformation rate is (length before deformation−length after deformation) × 100 / (length before deformation) (%). Alternatively, (deformed length) × 100 / (length before deformation) (%).

  Further, when a uniaxial heat-shrinkable film is used as the base film 31 as described above and this is heat-shrinked in the next deformation step, the uneven pattern 13 ′ can be formed more easily. The rate is preferably 0.01 to 300 GPa, more preferably 0.1 to 10 GPa.

  As the resins constituting the matrix resin 22a and the particles 22b used in the coating liquid, those already exemplified can be used. The glass transition temperature Tg2 of the matrix resin 22a and the glass transition temperature Tg3 of the particles 22b are the base materials. It is important to select and combine the materials so that the glass transition temperature Tg1 of the film 31 is 10 ° C. or higher. Thus, after selecting each material, the laminated sheet which provided the hard layer 32 whose thickness t 'exceeds 0.05 micrometer and is 5.0 micrometers or less on the single side | surface of the uniaxial heat-shrinkable film (base film 31). When 30 is used, a wavy uneven pattern 13 ′ in which the most frequent pitch is 3 to 20 μm and the average height of the protrusions 13 a ′ is 4 to 7 μm is easily formed through the following deformation process.

  As a solvent used for the coating liquid, depending on the type of the matrix resin 22a, when the matrix resin 22a is an acrylic resin, for example, one or more of methyl ethyl ketone and methyl isobutyl ketone can be used.

  The concentration of the matrix resin 22a in the coating solution is preferably 5 to 10% by mass as a net amount (solid content) from the viewpoint of coating properties. Moreover, it is preferable that it is 10-50 mass parts with respect to 100 mass parts of net amounts of the matrix resin 22a, and, as for the quantity of the particle | grains 22b, it is more preferable that it is 30-40 mass parts. Within such a range, the ratio of the area occupied by the convex portion 14a 'or the concave portion in the fine irregularities to be formed, the average length of the ridge lines of the convex stripes, and the direction of the wide light distribution in the arrangement direction of the convex stripes having a small pitch. The deviation can be controlled within the preferred range described above.

  Here, the net amount (solid content) refers to the ratio of the mass of the solid content remaining after the solvent in the coating solution volatilizes with respect to the mass (100 mass%) of the coating solution.

  Note that the thickness t ′ of the hard layer 32 formed in the laminating step may be continuously changed as long as it is in the range of more than 0.05 μm and 5.0 μm or less. In that case, the pitch and depth of the concavo-convex pattern formed by the deformation process are continuously changed. The thickness t ′ of the hard layer 32 hardly changes even after the next deformation step, and can be considered as t ′ = t.

(Deformation process)
By heating the laminated sheet 30 obtained as described above and causing the base film 31 of the laminated sheet 30 to thermally shrink, the surface fine uneven body 20 of FIG. 16 is obtained. In addition, as a deformation | transformation process, the well-known method disclosed by the Japan patent 4683011 etc. is employable, for example.

  Examples of the heating method include a method of passing through hot air, steam, hot water, or far infrared rays. Among them, a method of passing through hot air or far infrared rays is preferable because it can be uniformly contracted.

  The heating temperature (processing temperature) at the time of heat shrinking the base film 31 is preferably set to a temperature between Tg2 and Tg1, and specifically, the type of the base film 31 to be used and the intended uneven pattern. It is preferable to select appropriately according to the pitch of 13 ', the height of the protruding portion 13a', and the like.

  In this manufacturing method, the thinner the thickness of the hard layer 22 and the lower the Young's modulus of the hard layer 22, the smaller the most frequent pitch of the uneven pattern 13 ′ and the higher the deformation rate of the base film 31. The height of the ridge portion 13a ′ increases as the height increases. Therefore, in order to set the most frequent pitch of the concavo-convex pattern 13 ′ and the height of the ridge 13 a ′ to desired values, it is necessary to appropriately select the above conditions.

In addition, the surface fine uneven | corrugated body 20 of a structure like FIG. 16 can also be manufactured by the method of following (1)-(4).
(1) A method of forming a laminated sheet by providing an undeformed hard layer on one side of a flat base film, and compressing the whole laminated sheet in one direction along the surface.

When the glass transition temperature of the base film is lower than room temperature, the laminated sheet is compressed at room temperature. When the glass transition temperature of the base film is higher than the room temperature, the laminated sheet is compressed above the glass transition temperature of the base material and hard. Performed below the glass transition temperature of the layer.
(2) An undeformed hard layer is provided on one side of a flat base film to form a laminated sheet, the laminated sheet is stretched in one direction, and the direction perpendicular to the stretching direction is shrunk to form a hard layer. A method of compressing in one direction along the surface.

When the glass transition temperature of the base film is lower than room temperature, the lamination sheet is stretched at room temperature. When the glass transition temperature of the base film is room temperature or higher, the stretching of the laminated sheet is equal to or higher than the glass transition temperature of the base film. It is performed below the glass transition temperature of the hard layer.
(3) A flat base film formed of an uncured ionizing radiation curable resin is laminated with an undeformed hard layer to form a laminated sheet, and the base film is cured by irradiation with ionizing radiation. A method of compressing the hard layer laminated on the base film in at least one direction along the surface.
(4) An undeformed hard layer is laminated on a flat base film swelled by swelling a solvent to form a laminated sheet, and the solvent in the base film is dried and contracted by removing it. The method of compressing the hard layer laminated | stacked on the base film in at least one direction along the surface.

  In the method of (1), as a method of forming a laminated sheet, for example, a resin solution or dispersion containing particles is applied to one side of a flat base film using a spin coater or bar coater, and a solvent is used. Examples thereof include a drying method and a method in which a hard layer prepared in advance is laminated on one side of a flat base film. Examples of the method for compressing the entire laminated sheet in one direction along the surface include a method of compressing the laminated sheet by sandwiching one end portion of the laminated sheet and the opposite end portion thereof with a vise or the like.

  In the method (2), examples of the method of stretching the laminated sheet in one direction include a method of stretching by stretching one end portion of the laminated sheet and the opposite end portion thereof.

  In the method (3), examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin.

  In the method (4), the solvent is appropriately selected according to the type of resin constituting the base film. The drying temperature of the solvent is appropriately selected according to the type of solvent.

  Also in the hard layer in the methods (1) to (4), the same components as those used in the above method can be used, and the thickness can be the same. Moreover, the formation method of a lamination sheet is the same as the method of the above-mentioned lamination process, The method of applying a coating liquid on the single side | surface of a base film, and drying a solvent, The hard material produced beforehand on the single side | surface of a base film A method of stacking layers can be applied.

Note that, as in the present invention, the arrangement direction of the ridges of the surface concavo-convex structure varies depending on the pitch of the ridges, and the smaller the pitch, the greater the deviation of the arrangement direction from the wide light distribution direction. The reason is considered as follows.
When the particle concentration of the hard layer is relatively high, regions where particles are densely scattered are scattered in an island shape. When there is no particle assembly region, in the deformation process of the laminated sheet, when there is a particle assembly region, the ridges that are arranged substantially in parallel, and when there is a particle assembly region, changes due to the smaller pitch projections being pushed by the particle assembly region It is considered that the arrangement is substantially out of parallel because of the large influence of.

[Manufacturing method of surface irregularities by transfer using original plate]
When producing the light distribution control sheet 10 of the illustrated example using the surface fine irregularities 20 of FIG. 16 as a master, a transfer step of transferring the fine irregularities of the surface fine irregularities (original) 20 to another material. I do. In this example, the fine irregularities formed on the surface of the hard layer 22 of the surface fine irregularities (original) 20 are transferred to another material, and a primary transfer product having a reverse pattern of the fine irregularities of the original on the surface is obtained. Then, the reverse pattern of the primary transfer product is transferred to another material to obtain the light distribution control sheet 10 of the illustrated example which is a secondary transfer product. As the transfer step, for example, a publicly known method disclosed in Japanese Patent No. 4683011 can be adopted.

  One aspect of the present invention is a method for producing a surface fine unevenness using the surface fine unevenness described above as an original plate.

  Specifically, an uncured ionizing radiation curable resin containing a release agent is accommodated in a thickness of, for example, 3 to 30 μm with respect to the fine unevenness of the surface fine unevenness 20 of FIG. After coating with a coater such as a die coater, roll coater, or bar coater and irradiating with ionizing radiation to cure, the original is peeled off to obtain a primary transfer product. The primary transfer product has a reversal pattern of fine irregularities of the original plate. On the other hand, a transparent substrate 11 made of PET is prepared, and an uncured ionizing radiation curable resin is applied on one surface thereof with a thickness that sufficiently covers fine irregularities. Then, the surface of the applied uncured ionizing radiation curable resin is pressed against the surface having the reversal pattern of the previously obtained primary transfer product and cured by irradiation with ionizing radiation. Peel off the next transfer product. Irradiation with ionizing radiation may be performed from either one of the primary transfer product side and the transparent PET substrate side having ionizing radiation transparency. 1 comprising a transparent base material 11 made of PET and a surface layer 12 of a cured ionizing radiation curable resin formed on one side thereof, and FIG. 1 in which fine irregularities are formed on the surface of the surface layer 12 The light distribution control sheet (secondary transfer product) 10 of FIG. 3 is obtained.

  Examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin. The type of ionizing radiation to be irradiated is appropriately selected according to the type of resin. In general, the ionizing radiation often means ultraviolet rays and electron beams, but in the present specification, visible rays, X-rays, ion rays and the like are also included.

  Uncured ionizing radiation curable resins include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl / acrylate, polyene / acrylate, silicon acrylate, polybutadiene, and polystyrylmethyl methacrylate. 1 type selected from monomers such as prepolymers such as aliphatic acrylate, alicyclic acrylate, aromatic acrylate, hydroxyl group-containing acrylate, allyl group-containing acrylate, glycidyl group-containing acrylate, carboxy group-containing acrylate, halogen-containing acrylate, etc. What contains the above component is mentioned. The uncured ionizing radiation curable resin is preferably diluted with a solvent or the like. A fluorine resin, a silicone resin, or the like may be added to the uncured ionizing radiation curable resin. When the uncured ionizing radiation curable resin is ultraviolet curable, it is preferable to add a photopolymerization initiator such as acetophenones and benzophenones to the uncured ionizing radiation curable resin.

  Also, instead of ionizing radiation curable resin, transfer is performed using, for example, thermosetting resin such as uncured melamine resin, urethane resin or epoxy resin, or thermoplastic resin such as acrylic resin, polyolefin or polyester. As long as fine irregularities can be transferred, the specific method and material to be transferred are not limited.

  In the case of using a thermosetting resin, for example, a method of applying a liquid uncured thermosetting resin to fine irregularities and curing it by heating is mentioned. When using a thermoplastic resin, a sheet of thermoplastic resin is used. There is a method of heating and softening while pressing against fine irregularities and then cooling.

  In addition, as described above, in the case of producing a secondary transfer product, for example, a method using a plating roll described in Japanese Patent No. 4683011 is also exemplified. Specifically, first, a long sheet-like material is manufactured as an original plate, the original plate is rounded and attached to the inside of a cylinder, plating is performed with a roll inserted inside the cylinder, and the roll is removed from the cylinder. Take out and obtain a plating roll (primary transfer product). Next, a light distribution control sheet (secondary transfer product) is obtained by transferring the fine irregularities of the plating roll.

  As the original plate, either a single wafer type or a web type can be used. If a web type master is used, a web type primary transfer product and a secondary transfer product can be obtained. In the single-wafer type, a stamp method using the single-wafer type original as a flat plate, a roll imprint method using a single-wafer type original wound around a roll as a cylindrical die, and the like can be applied. Further, a single-wafer type master may be arranged inside the mold of the injection molding machine. However, in the method using these single-wafer type masters, it is necessary to repeat the transfer many times in order to mass-produce the light spreading powder sheet as shown in the illustrated example. When the transferability (releasability) is low, clogging occurs in the fine unevenness to be transferred, and the transfer of the fine unevenness may be incomplete. On the other hand, when the original plate is a web type, fine irregularities can be transferred continuously in a large area, and a necessary amount of light distribution control sheet can be produced in a short time without repeating many transfers.

[Modification of manufacturing method of original plate and manufacturing method of fine surface irregularities by transfer using original plate]
In the above-described lamination process of [Original Plate Manufacturing Method], a coating liquid containing matrix resin 22a, particles 22b, and a solvent was used. However, a hard layer is formed using a coating liquid that does not contain particles and contains a matrix resin and a solvent, and is formed into a wavy uneven pattern by a deformation process, and then a large number of recesses or protrusions on the uneven pattern. May be formed. The method for forming the hard layer can be performed in the same manner as described above except that particles are not used. The deformation process can also be performed in the same manner as described above. Next, as a method for forming a large number of concave portions or convex portions on the formed concave / convex pattern, the following methods (5) to (8) are exemplified.
(5) A method of cutting with a rotary precision cutting machine.
(6) A method of forming a recess by pressing a projection having the same size and diameter as the recess or the protrusion onto the wavy uneven pattern.
(7) A method of forming a convex portion formed of the resin or the inorganic substance by adhering a fine resin or inorganic melt to the wavy uneven pattern and then solidifying it by cooling.
(8) A method in which a liquid in which a resin or an inorganic substance is dispersed in a dispersion medium is deposited on the wavy uneven pattern, and then the dispersion medium is evaporated to form a convex portion formed of the resin or the inorganic substance.

  In addition, by applying the inkjet printing method in the method (7) or (8), a large number of concave portions or convex portions can be formed on the wavy uneven pattern with high accuracy.

  In addition, a hard layer is formed using a coating liquid that does not contain particles and contains a matrix resin and a solvent, and is formed into a wavy uneven pattern by a deformation process (a large number of recesses or protrusions have not yet been formed) ) As an original plate, a transferred product may be obtained, and a plurality of concave portions or convex portions may be formed on the concavo-convex pattern by the above methods (5) to (8). And by transferring this as an original plate, it is possible to produce a surface fine unevenness.

<About other forms>
In the above description, using the surface fine unevenness produced by the laminating process and the deformation process as an original plate, a primary transfer product obtained by transferring the fine unevenness of the surface fine unevenness is obtained, and then the primary transfer product of The secondary transfer product to which the fine unevenness (reversal pattern of the original plate) was transferred was used as the light distribution control sheet 10.

  However, the present invention is not limited to the above form.

  That is, the surface fine unevenness 20 itself as shown in FIG. 16 manufactured by the above-described lamination process and deformation process can also be used as a light distribution control sheet. Moreover, the primary transfer product obtained by using the surface fine irregularities 20 produced by the lamination process and the deformation process as an original plate, and the n-th transfer product (n is an integer of 3 or more) are used as the light distribution control sheet. If it is a transfer product, it is not limited to a secondary transfer product.

  Moreover, you may transfer a fine unevenness | corrugation to the said curved surface of the molded object which has a curved surface using an original plate.

  Also, using the surface fine irregularities produced by the laminating process and the deformation process and the n-order transfer product as an original plate, a transparent thermoplastic resin such as an acrylic resin or a polycarbonate resin is injection-molded, and the fine irregularities are at least on the surface. You may manufacture the injection molded product formed in part.

  In the n-order transfer product obtained by using the surface fine irregularities 20 produced by the laminating process and the deformation process specifically shown above as an original plate, when n is an odd number, as the fine irregularities, a specific corrugation On the concave / convex pattern, concave portions are formed instead of convex portions. This is because in the n-th order transfer product in which n is an odd number, a reverse pattern of the convex portion formed based on the particles, that is, a concave portion is formed. In this way, even if the surface fine irregularities have a concave portion with a specific wavy concave / convex pattern as the fine concave / convex portions, the anisotropy due to the wavy concave / convex pattern is weakened by the concave portion. And also has some FWHM in direction X. Therefore, even if the n-order transfer product has an odd number n, the light distribution control performance is equivalent to that of the n-order transfer product where n is an even number.

  In addition, as the particles used for forming the hard layer, resin particles and inorganic particles can be used, and any material can be used as long as it is not melted or deformed in the deformation process or the process of transferring fine irregularities. There may be. However, as described above, when the surface fine irregularities 20 having the particles themselves as shown in FIG. 16 are used as the light distribution control sheet, the particles are transparent particles, preferably acrylic cross-linked resin particles, glass It is necessary to use beads, polystyrene-based crosslinked resin particles, and the like.

  Moreover, in the above example, although a sheet-like thing was illustrated as a surface fine unevenness | corrugation body and a light distribution control sheet, it is not limited to a sheet-like thing, A solid molded object may be sufficient.

  Further, the fine unevenness may be formed in any part depending on the purpose as long as it is at least a part of the surface of the surface fine unevenness. For example, when the surface fine unevenness is a sheet-like material, it may be formed on only one surface, on both surfaces, or may be formed on only part of each surface, You may form in at least one part of the surrounding surface (end surface) of a thing.

Furthermore, even when the surface fine irregularities are three-dimensional molded bodies, they may be formed on the entire surface or only on a part thereof. In addition, when the surface fine unevenness | corrugation body is a three-dimensional molded object, the said three-dimensional molded object can be used for the use similar to the use illustrated about the light distribution control sheet. That is, a light distribution control member for a projector; a light distribution control member for a backlight of a television, a monitor, a notebook personal computer, a tablet personal computer, a smartphone, a mobile phone, etc .; an LED light source used for a copier, etc. In a linearly arranged scanner light source, it can be suitably used as a light distribution control member that constitutes at least the exit surface of the light guide member.

10: Light distribution control sheet, 13: Wavy uneven pattern, 13a: Convex part, 13b: Concave part, 14: Convex part, 20: Surface fine unevenness (original), 21: Base material, 22: Hard layer 22a: matrix resin, 22b: particles, 31: base film, 32: hard layer (undeformed)

Claims (12)

It is a surface fine concavo-convex body in which fine concavo-convex is formed on at least a part of the surface, and the fine concavo-convex comprises a plurality of ridges meandering non-parallel to each other and a ridge between the plurality of ridges. A plurality of concave portions or convex portions formed on the wavy concave and convex pattern, and at least some of the plurality of concave portions or convex portions are present in a plurality of island-shaped aggregate regions. Surface fine irregularities. The surface fine concavo-convex body according to claim 1, wherein an average length of ridge lines of the plurality of ridges is 10 to 100 μm. The surface fine unevenness according to claim 1 or 2, wherein in the wavy uneven pattern, there are protrusions having a large deviation from the wide orientation distribution direction in the arrangement direction and having a disordered parallelism than other protrusions. body. The surface fine concavo-convex body has a FWHM (FWHM _Y ) in a direction Y in which light passing through the surface on which the fine concavo-convex is formed is most widely distributed, and a FWHM (FWHM in a direction X orthogonal to the direction Y _X ) satisfies the following formula (1), FWHM _X is 4 ° or more, and the Fourier transform image of the surface image of the fine unevenness is represented by the Y direction and the horizontal direction of the Fourier transform image. , The shape of the white portion extending in the left-right direction from the center of the Fourier transform image after the rotation indicates that the vertical position indicating the frequency peak is from the horizontal zero point. If the distance changes depending on the distance, and the distance exceeds a certain size, the distance from the zero point in the vertical direction increases, and the shape on the left and right with respect to the zero point becomes a sword shape that matches when rotated 180 degrees. Toss Surface fine irregularities according to any one of claims 1 to 3.
FWHM _Y / FWHM _X ≧ 1.2 (1) The surface fine concavo-convex body according to any one of claims 1 to 4, wherein an area ratio of the plurality of concave and / or convex portions is 30 to 70% of a surface area of the surface fine concavo-convex body. The surface fine unevenness according to any one of claims 1 to 5, wherein a mode pitch of the plurality of ridges is 3 to 20 µm, and an apparent mode diameter of the recesses or projections is 1 to 10 µm. The surface fine unevenness according to any one of claims 1 to 6, wherein an average height of the protruding strips is 4 to 7 µm. It is a manufacturing method of the surface fine concavo-convex body according to any one of claims 1 to 7,
A laminating step of forming a laminated sheet by providing a hard layer containing a matrix resin and particles dispersed in the matrix resin on at least one surface of the base film;
A deformation step of deforming at least the hard layer of the laminated sheet so as to be folded to form surface fine irregularities on at least one surface of the laminated sheet. The base film has a property of shrinking by heating, and the deforming step is a step of deforming the hard layer by folding the base sheet by heating the laminated sheet. The manufacturing method of the surface fine grooving | roughness body of Claim 8. The glass transition temperature of the matrix resin is 10 ° C. higher than the glass transition temperature of the main component constituting the base film,
The surface fine concavo-convex body according to claim 9, wherein the particle is mainly composed of a material whose particle shape is not changed by heat at a temperature lower than 10 ° C higher than the glass transition temperature of the main component constituting the base film. Manufacturing method. The manufacturing method of the surface fine unevenness | corrugation body as described in any one of Claims 8-10 whose particle size of the said particle | grain is larger than the thickness of the said hard layer in the said lamination process. It is a manufacturing method of the surface fine unevenness which manufactures the surface fine unevenness | corrugation as described in any one of Claims 1-7,
A laminating step of forming a laminated sheet by providing a hard layer containing a matrix resin and particles dispersed in the matrix resin on at least one surface of the base film;
A deformation step of deforming at least the hard layer of the laminated sheet so as to fold, and forming surface fine irregularities on at least one side of the laminated sheet;
Using at least part of the surface fine irregularities obtained in the deformation step as a master,
The manufacturing method of the surface fine unevenness | corrugation which has the transfer process which transfers surface fine unevenness | corrugation.