JPWO2007077737A1 - Mold parts and flat plate molded products - Google Patents

Abstract

Provided is a mold part capable of efficiently forming a flat molded article having excellent optical performance. In the mold part, a concavo-convex structure having a maximum centerline average roughness Ra (max1) of 3.0 to 1000 μm is formed on the cavity surface for forming the surface of the flat molded product. Each concavo-convex structure has a concave or convex structural unit having two or more planes, and a plurality of concavo-convex portions are formed on each plane of the structural unit. In the plane having the concavo-convex portion, the maximum center line average roughness Ra (max 2) satisfies the relationship of 0.5> Ra (max 2) / Ra (max 1)> 0.002 with Ra (max 1), and is the minimum The relationship of Ra (max2) / Ra (min2)> 1.5 is satisfied with the centerline average roughness Ra (min2).

Description

  The present invention relates to a mold part, and more particularly, to a mold part that can efficiently mold a molded article having excellent optical performance.

  Conventionally, in the mold for injection molding, the surface (cavity surface) of the mold is sometimes mirror-finished for the purpose of improving the surface and appearance of a molded product such as a lens or a reflector. However, in this case, depending on the type of resin constituting the molded product, the mold and the molded product may be in close contact with each other, making it difficult to release the molded product. Therefore, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-287227), the mold surface has a ten-point average roughness Rz of 0.2 to 3.0 μm to provide a mold release property. Is disclosed.

  By the way, a liquid crystal display device may use a direct type backlight device having a reflection plate, a plurality of light sources, and a light diffusion plate. The light diffusing plate used in such a direct type backlight device has a technique for making the luminance of the surface of the light diffusing plate uniform (to increase the luminance uniformity) because the portion directly above the light source tends to have high luminance. It is being considered.

  The inventors improve the luminance uniformity by providing, for example, a prism array in which a plurality of linear prisms having a polygonal cross section are arranged on the surface of the light diffusion plate, extending substantially parallel to the longitudinal direction of the light source. Has already been found (Japanese Patent Application No. 2004-243479 (Japanese Patent Laid-Open No. 2006-66074)). Such a light diffusing plate can be obtained by forming a concavo-convex structure corresponding to the prism row on the cavity surface of a mold and performing injection molding using the mold. However, when the light diffusing plate having such a concavo-convex structure is injection-molded, it may be difficult to release the light diffusing plate, which is a molded product, and the molding operation is not always efficient.

Therefore, it is conceivable to roughen the cavity surface of the mold for forming the light diffusing plate having the prism rows by using the technique shown in Patent Document 1 described above, but simply applying this technique. However, although the mold releasability of the molded product can be improved, there are cases where the optical performance such as luminance uniformity cannot be sufficiently exhibited.
Such a problem is not limited to the case where the molded product is a light diffusing plate, but also occurs in a flat molded product used for other optical components such as a light guide plate and a reflective plate.

  An object of the present invention is to provide a mold part capable of efficiently forming a flat molded article having excellent optical performance.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have provided sufficient optical characteristics by providing a predetermined uneven portion on each surface of a concave or convex structural unit for forming a pattern portion on a flat plate molded product. It has been found that a mold part capable of easily molding a molded product having performance is obtained, and the present invention has been completed based on this finding.

  The present invention is a mold part for forming a resin-made flat molded product used for an optical component, and has a cavity surface for forming a surface of the flat molded product, A concavo-convex structure having a maximum centerline average roughness Ra (max1) measured in a direction in which the centerline average roughness Ra is maximum on the cavity surface is 3.0 μm to 1,000 μm, and the two concavo-convex structures are provided A plurality of concave or convex structural units having the above planes are provided as repeating units, and at least one of the two or more planes of the structural unit includes a plurality of concave and convex portions, and includes these concave and convex portions. On the other plane, the maximum centerline average roughness Ra (max2) measured in the direction in which the centerline average roughness Ra on the plane is maximum is 0.5> Ra ( max2) / Ra (max1)> 0.002 And the minimum centerline average roughness Ra (min2) measured in the direction in which the centerline average roughness Ra on the plane is minimum, Ra (max2) / Ra (min2)> 1. 5 is satisfied. The mold part includes a stamper provided on the mold in addition to the mold itself.

  Here, in the mold part, when the Ra (max 2) is measured in the same direction as the measurement direction, an average interval Sm between the adjacent concavo-convex parts is between Ra (max 1) and Ra The relationship 3 of (max1) × 10> Sm> Ra (max1) × 0.001 may be satisfied.

The structural unit may be a linear portion having a polygonal cross section extending linearly, and the concavo-convex structure may be configured such that a plurality of the linear portions are arranged substantially parallel to each other. At this time, the linear portion has a triangular cross-sectional shape with an apex angle of 60 ° to 170 °, and a distance between a linear portion and a linear portion adjacent to the linear portion is 20 μm to 700 μm. It can be configured. Note that the term “polygon” is used for convenience of explanation, as an open path of a line segment (cross-sectional plain) corresponding to each concave or convex portion of the linear portion (open
path composed of line segments). Then, according to the number of sides or points of a closed path obtained by connecting both ends of the open path, these are called in correspondence with the polygon (which is usually meant).

  Further, the linear part has four or more planes, and at least two of the four or more planes are inclined to one side with respect to the thickness direction of the mold part, and A plane other than the at least two planes may be inclined to the opposite side of the at least two planes.

  Further, the linear portion has a triangular cross section, and an angle formed between one of two planes constituting the triangle and a plane orthogonal to the thickness direction of the mold part is two of the two planes constituting the triangle. It is equal to the angle formed by the other of the planes and the surface perpendicular to the thickness direction of the mold part, and the angle is perpendicular to the specific X point and the longitudinal direction of the linear portion from this X point. It is good also as a structure which becomes large continuously or in steps as it leaves | separates from the said X point and the said Y point between the Y points which left | separated predetermined distance along the direction. Here, the angle formed between each of the two inclined surfaces and the surface in the direction orthogonal to the thickness direction of the mold part is “equal” when the difference between the angles formed is within 1 °.

  In the mold part, the structural unit may be a convex structure or a concave structure having three or more planes. At this time, the convex structure or the concave structure having the three or more planes may be a pyramid or a truncated pyramid.

  Further, the structural unit is a convex structure having three or more planes, and the convex structure forms a linear portion having a polygonal cross section extending in a linear shape, and then the linear portion is connected to the linear portion. It can be obtained by making a V-shaped notch in a direction different from the longitudinal direction.

  In addition, the structural unit is a concave structure having three or more planes, and the concave structure forms a linear section having a polygonal cross section extending linearly, and then the linear section is formed on the linear section. It is good also as what is obtained by transcribe | transferring the said convex shape of the transfer member which has a convex shape obtained by making a V-shaped cut | notch in the direction different from the longitudinal direction.

  Moreover, the said uneven | corrugated | grooved part may be formed in the plane of the one part structural unit of the said some structural unit.

  Moreover, the said uneven | corrugated | grooved part may be formed only in the one part plane of the said 2 or more planes which comprise the said structural unit. As such a configuration, for example, when the structural unit is a triangular section and a linear portion, a configuration in which an uneven portion is formed only on one of the two exposed planes can be exemplified.

  Moreover, the said uneven | corrugated | grooved part may be formed only in a part of said plane which comprises the said structural unit. As such a configuration, for example, a case where an uneven portion is formed only at the central portion of each surface can be cited.

  Further, the following inventions are provided in relation to the present invention. A related invention is, for example, a flat plate molded product for an optical component such as a light diffusion plate obtained by injection molding using the mold component. Another related invention is a method of manufacturing a resin-made flat molded product used for an optical component by injection molding using the mold component.

  According to the present invention, on the surface of the concavo-convex structure whose maximum center line average roughness Ra (max1) measured in the direction in which Ra is maximum on the cavity surface is 3.0 μm to 1,000 μm, on the plane of the structural unit. The relationship between 0.5> Ra (max2) / Ra (max1)> 0.002 between the maximum center line average roughness Ra (max2) measured in the direction in which Ra is maximum in the above and Ra (max1) The relationship of Ra (max 2) / Ra (min 2)> 1.5 with the minimum center line average roughness Ra (min 2) measured in the direction in which Ra is minimized on the plane of the structural unit By providing the concavo-convex portion satisfying 2, there is an effect that a flat molded product having excellent optical performance can be efficiently molded.

FIG. 1 is a perspective view schematically showing a mold part according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view partially showing a cross section along the thickness direction of the mold part. FIG. 3 is a partial sectional view schematically showing a mold part according to the first modification of the present invention. FIG. 4 is a partial cross-sectional view schematically showing a mold part according to a second modification of the present invention. FIG. 5 is a partial cross-sectional view schematically showing a mold part according to a third modification of the present invention. FIG. 6 is a perspective view schematically showing the direct type backlight device according to Embodiment 1 of the present invention. FIG. 7 is a cross-sectional view showing a stamper according to a fourth modification of the present invention. FIG. 8 is a cross-sectional view showing a stamper according to a fifth modification of the present invention. FIG. 9 is an enlarged cross-sectional view of the range X in FIG. FIG. 10 is a cross-sectional view showing a modification of the row portion in the mold part of the present invention. FIG. 11 is a cross-sectional view showing a stamper according to a sixth modification of the present invention. FIG. 12 is a cross-sectional view showing a stamper according to a seventh modification of the present invention.

A mold part according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing a stamper 1 which is a mold part according to the present embodiment. FIG. 2 is a view partially showing a cross section along the thickness direction of the stamper 1. The stamper 1 is a member for forming a resin flat plate molded product used for an optical component. Examples of the molded flat product include optical components such as a light diffusion plate, a light guide plate, and a reflection plate.

  Here, as the resin constituting the flat plate molded product, a transparent resin can be used from the viewpoint of not reducing the luminance. The transparent resin is a resin having a total light transmittance of 70% or more measured with a 2 mm-thick plate smooth on both sides based on Japanese Industrial Standard JIS K7361-1 (ISO 13468-1). For example, polyethylene, Propylene-ethylene copolymer, polypropylene, polystyrene, copolymer of aromatic vinyl monomer and (meth) acrylic acid alkyl ester having lower alkyl group, polyethylene terephthalate, terephthalic acid-ethylene glycol-cyclohexanedimethanol copolymer Examples thereof include a coalescence, a polycarbonate, an acrylic resin, and a resin having an alicyclic structure. In addition, (meth) acrylic acid is acrylic acid and methacrylic acid.

  Moreover, as the resin, a resin obtained by adding a light diffusing agent to the transparent resin may be used. The light diffusing agent is a particle having a property of diffusing light, and can be roughly classified into an inorganic filler and an organic filler. Examples of the inorganic filler include silica, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, and a mixture thereof. Examples of the organic filler include acrylic resin, polyurethane, polyvinyl chloride, polystyrene resin, polyacrylonitrile, polyamide, polysiloxane resin, melamine resin, and benzoguanamine resin.

  The stamper 1 is disposed at a position corresponding to the cavity surface of the injection mold. In the present embodiment, the mold part of the present invention is a stamper, but it may be a movable or fixed mold (core block, cavity block) or the like.

  As shown in FIGS. 1 and 2, the stamper 1 has a concavo-convex structure 2 formed on a surface serving as a cavity surface. The concavo-convex structure 2 is a sawtooth cross-sectional structure in which a plurality of convex structural units linear portions 3 are arranged substantially in parallel with each other and the bottom angles of the linear portions 3 are continuous.

  As shown in FIG. 2, the linear portion 3 has a triangular shape having two inclined surfaces (planes) 4 and a convex section. The apex angle θ of the linear portion 3 is 60 ° to 170 °, preferably 70 ° to 160 °. The width dimension W of the bottom part of the linear part 3 is 20 micrometers-700 micrometers, Preferably it is 30 micrometers-600 micrometers. The height H of the linear portion 3 is 0.9 μm to 606 μm, and preferably 2.6 μm to 428 μm. The cross-sectional shape of the linear portion 3 is preferably an isosceles triangle in that the optical performance of the molded flat plate product is improved. Moreover, the space | interval (pitch) P between the adjacent linear parts 3 is 20 micrometers-700 micrometers, Preferably they are 30 micrometers-600 micrometers. The space | interval of the linear parts 3 is the distance of each vertex of an adjacent linear part.

  In the concavo-convex structure 2 constituted by such a plurality of linear portions 3, the maximum centerline average roughness Ra (max1) measured in the A direction which is a direction perpendicular to the thickness direction of the stamper 1 is 3.0 μm to 1. , 000 μm, preferably 4.0 μm to 900 μm. The direction A is the direction in which Ra is maximum. The centerline average roughness Ra can be determined based on JIS B0601.

  A plurality of linear recesses 4 </ b> A that are uneven portions are formed on the surface of each inclined surface 4 of the linear portion 3. 4 A of linear recessed parts are extended substantially parallel to the longitudinal direction (direction perpendicular | vertical to the paper surface of FIG. 2) of the linear part 3. As shown in FIG. These linear recesses 4A are substantially parallel to each other. In the slope 4, between the maximum centerline average roughness Ra (max2) measured along the B direction and the C direction, which are directions along the slope 4A in the figure, and the Ra (max1), 0.5 The relation 1 of> Ra (max2) / Ra (max1)> 0.002 is satisfied. The B direction and the C direction are directions in which Ra is maximum.

  Further, on the surface of the slope 4 where the linear recess 4A is formed, Ra (max2) is between the minimum center line average roughness Ra (min2) measured in the longitudinal direction of the linear recess 4A and Ra (max2). The relationship 2 of max2) / Ra (min2)> 2 is satisfied. Note that the longitudinal direction of the linear recess 4A is a direction in which Ra is minimized.

  The average distance Sm between the adjacent linear recesses 4A measured in the B direction and the C direction is Ra (max1) × 10> Sm> Ra (max1) × 0 between the Ra (max1). It is preferable that the relationship of .001 is satisfied, and it is more preferable that the relationship of Ra (max1) × 9> Sm> Ra (max1) × 0.002 is satisfied.

The stamper 1 as described above is manufactured, for example, as follows.
First, a nickel-phosphorous electroless plating layer having a thickness of, for example, about 100 μm is applied to the entire surface of a metal rectangular plate. Next, on the surface of the plated layer, using a machine tool for microfabrication (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.) equipped with a sintered diamond bit having a predetermined apex angle, The concavo-convex structure 2 having a plurality of linear portions 3 having a triangular cross section is formed by cutting along a predetermined pitch. Here, the sintered diamond bite has a shape in which slight irregularities are formed on the surface thereof as compared with the single crystal diamond bite. For this reason, a plurality of linear recesses 4 </ b> A are formed on the slope 4 of the linear portion 3 along the longitudinal direction of the linear portion 3 due to the uneven portions of the sintered diamond bite. The stamper 1 is produced as described above.

  The stamper 1 produced in this way is arranged so that the surface on which the concavo-convex structure 2 is formed becomes the cavity surface of the injection mold, and is injection molded using the resin, thereby obtaining a light diffusing plate or the like. An optical component that is a flat plate molded product can be molded.

  According to the present embodiment, the linear recess 4A is provided on the slope 4 of the linear portion 3 of the stamper 1 so that the center line average roughness Ra satisfies the relations 1 and 2, and this fine linear shape is provided. Since the molding resin does not easily enter the recess 4 </ b> A, the flat molded product can be easily released from the stamper 1 because a gap may be formed between the stamper 1 and the flat molded product. For this reason, a flat plate molded product can be molded efficiently. In addition, the flat plate molded product is formed with a prism row composed of linear prisms having a triangular cross section corresponding to the concavo-convex structure 2 composed of a plurality of linear portions 3. When a molded product is used as a light diffusing plate and this light diffusing plate is arranged on a plurality of light sources to produce a direct type backlight device, the luminance unevenness is reduced while maintaining sufficient luminance (luminance uniformity). A device having a light emitting surface with a high degree of lightness can be obtained. Therefore, the obtained flat plate molded article has sufficient optical performance. As mentioned above, according to this embodiment, there exists an effect that the flat molded product excellent in optical performance can be shape | molded efficiently.

  Since the uneven structure 2 of the stamper 1 is transferred to at least one main surface of the flat molded product obtained by the stamper 1, the prism row is formed on the flat molded product. An uneven structure corresponding to the linear portion 3 can be formed on each plane of each linear prism constituting the prism row. However, if the releasability between the flat plate molded product and the mold part is taken into consideration, the linear shape is formed. It is preferable that the uneven structure corresponding to the part 3 is not transferred so much, and at least the transferred part is in a partial range. In addition, the flat plate molded product of this embodiment is a light diffusing plate.

  The linear prism is a linear prism having a convex cross section and an isosceles triangle shape. The apex angle of the triangle is usually 60 ° to 170 °, preferably 70 ° to 160 °. The width of the base of the triangle is usually 20 μm to 700 μm, preferably 30 μm to 600 μm. The height of the triangle is usually 0.9 μm to 606 μm, preferably 2.6 μm to 428 μm. Moreover, the space | interval (pitch) between adjacent triangles is 20 micrometers-700 micrometers normally, Preferably it is 30 micrometers-600 micrometers.

  In such a prism array having a plurality of linear prisms, the maximum center line average roughness Ra (Dmax1) measured in the direction perpendicular to the plane including the thickness direction of the flat plate molded product and the longitudinal direction of the linear prisms is It is 3.0 micrometers-1,000 micrometers, Preferably it is 4.0 micrometers-900 micrometers. This direction is the direction in which Ra is maximum.

  Further, the surface of each inclined surface of the linear prism is an uneven surface to which the linear recess 4A of the stamper 1 is transferred. In this concavo-convex surface, between the maximum center line average roughness Ra (Dmax2) measured in a direction including a direction parallel to the inclined surface and perpendicular to the longitudinal direction of the linear prism, and Ra (Dmax1), The relationship 0.5> Ra (Dmax2) / Ra (Dmax1)> 0.002 is satisfied. The direction parallel to the slope and including the direction perpendicular to the longitudinal direction of the linear prism is the direction in which Ra is maximum.

  In the uneven surface, Ra (Dmin2) between the minimum center line average roughness Ra (Dmin2) measured in a direction parallel to the inclined surface and including the longitudinal direction of the linear prism, and Ra (Dmax2) Dmax2) / Ra (Dmin2)> 1.5 is satisfied. A direction parallel to the slope and including the longitudinal direction of the linear prism is a direction in which Ra is minimized.

  Further, the average distance Sm (D) of the portion corresponding to the linear recess 4A measured in the direction along the uneven surface is Ra (Dmax1) × 10> Sm () between the Ra (Dmax1). It is preferable that the relationship of D)> Ra (Dmax1) × 0.001 is satisfied, and it is more preferable that the relationship of Ra (Dmax1) × 9> Sm (D)> Ra (Dmax1) × 0.002 is satisfied. preferable.

<Modification>
In addition, this invention is not limited to the said embodiment.
For example, in the above-described embodiment, the concavo-convex portion of the slope 4 of the linear portion 3 is the linear concave portion 4A, but it may be a linear convex portion (linear convex portion), or a linear concave portion and a linear convex portion. It is good also as a structure which has both. In addition, a plurality of linear recesses 4 </ b> A are formed on the slope 4 so as to be substantially parallel to the longitudinal direction of the linear portion 3, but the plurality of linear recesses 4 </ b> A are substantially parallel to the longitudinal direction of the linear portion 3. It does not have to be. However, it is preferable that the plurality of linear recesses 4A are substantially parallel to each other.

  Moreover, in the said embodiment, although the linear part 3 was made into cross-sectional triangle shape, it is good also as polygonal shapes other than triangular shape. Here, as the polygonal linear portion, for example, as shown in FIG. 3, the concavo-convex structure 2 includes at least four surfaces 11 to 14, and two of the at least four surfaces 11 to 14 are provided. A configuration in which the surfaces 11 and 12 and the other two surfaces 13 and 14 are inclined in directions opposite to each other with respect to a surface perpendicular to the thickness direction of the stamper 1 (a surface including the left and right directions in the figure and perpendicular to the paper surface). It is good. By configuring the direct type backlight device using the light diffusing plate formed using the stamper having such a configuration and a plurality of light sources, the luminance and the luminance uniformity of the light emitting surface can be increased. Therefore, the light diffusing plate has sufficient optical performance.

  Moreover, in the said embodiment, although all apex angle (theta) of the linear part 3 was made into the same angle, you may make it apex angle (theta) differ. For example, the angle formed by one of the two planes constituting the cross-sectional triangle of the linear portion and the plane perpendicular to the thickness direction of the mold part is the other of the two planes constituting the triangle and the plane It is equal to an angle formed with a surface perpendicular to the thickness direction of the mold part, and the angle is a predetermined distance away from a specific X point and a direction perpendicular to the longitudinal direction of the linear portion from this X point. The distance between the point Y and the point Y can be increased continuously or stepwise as the point moves away from the point X and the point Y. That is, as shown in FIG. 4, the angle formed by the two inclined surfaces 4 of each linear portion 3 and the surface in the direction perpendicular to the thickness direction of the stamper 1 is formed to be equal. The angle θ is continuous or stepwise as it moves away from the point X and the point Y between the point Y and the point Y that is separated from the point Y by a predetermined distance along the direction perpendicular to the longitudinal direction of the linear portion 3 (left and right direction in the figure). You may form so that it may become small. By arranging a light source at a position corresponding to the point X and the point Y of the light diffusing plate formed using the stamper having such a configuration to constitute a direct type backlight device, the luminance and luminance uniformity of the light emitting surface Can be increased. Therefore, the light diffusing plate has sufficient optical performance.

  Moreover, in the said embodiment, the uneven structure 2 is good also as a convex structure or a concave structure which has three or more surfaces. As a concave structure or a convex structure having three or more surfaces, for example, a polygonal pyramid such as a square pyramid as shown in FIG. By constructing a direct backlight device using a light diffusing plate formed using a stamper having such a convex structure or a concave structure and a plurality of light sources, the luminance and luminance uniformity of the light emitting surface are increased. Can do. Therefore, the light diffusing plate has sufficient optical performance.

  The convex structure having three or more surfaces is formed in a V-shape in a direction different from the longitudinal direction of the linear portion after forming a linear portion having a concave or convex polygonal cross section. It can be formed with a cut in the shape.

  Further, the concave structure having three or more surfaces, for example, as shown in the embodiment, after forming a linear portion having a polygonal shape having a concave or convex cross-section, It can be formed by making a transfer member such as a stamper having a convex shape by making a V-shaped cut in a direction different from the longitudinal direction of the shape portion, and transferring the convex shape of the transfer member.

  In the above embodiment, the linear recesses 4A are formed on the entire slopes 4 of all the linear parts 3 over substantially the entire surface of the slopes 4. However, the present invention is not limited to this, The structure which provided the flat surface (mirror surface shape) without the linear recessed part 4A in the part of all the slopes 4 of the some linear part 3 is also contained. By providing a flat surface in this way, there is an advantage that it is possible to obtain a molded product with a higher luminance uniformity (with less luminance unevenness) while ensuring sufficient molding efficiency. A specific configuration of a stamper having a part of a flat surface is shown below.

FIG. 7 is a cross-sectional view showing a stamper 201 according to a fourth modification.
As shown in FIG. 7, the stamper 201 has a configuration in which a linear recess 4 </ b> A is formed only on the slope 4 of a part of the linear portions 3 among the plurality of linear portions 3. Such a stamper 201 can be easily produced by using both the sintered diamond bite and the single crystal diamond bite.

FIG. 8 is a cross-sectional view showing a stamper 202 according to a fifth modification.
As shown in FIG. 8, the stamper 202 has a configuration in which, on each inclined surface 4 of the plurality of linear portions 3, a linear convex portion (uneven portion) 4 </ b> B is formed only on a part of the inclined surface 4. Specifically, in the stamper 202, on the slope 4 constituting the linear portion 3, the linear convex portion 4B is formed only at the central portion of the slope 4 excluding the root side and the top side of the linear portion 3. ing. By forming the linear protrusion 4B only at the center portion, there is an advantage that the processing of the linear portion 3 can be facilitated.

  As shown in FIG. 8, the range of the central portion is D in the length in the direction along each inclined surface 4, and this length D is divided into three regions extending from the root side to the top side of the linear portion 3. When the length of each region is set to D1, D2, and D3 in the order described above, for example, the length D2 is 1% to 98% of the length D, the length D1 is 1% to 98% of the length D, The length D3 can be 1% to 98% of the length D. Further, it is preferable that the length D2 is 5% to 90% of the length D, the length D1 is 5% to 90% of the length D, and the length D3 is 5% to 90% of the length D. More preferably, the length D2 is 10% to 80% of the length D, the length D1 is 10% to 80% of the length D, and the length D3 is 10% to 80% of the length D. Specifically, for example, when the length D is 45.7 μm, the lengths D1 and D3 can be 4.6 μm and the length D2 can be 36.5 μm, respectively. In addition, although the length D2 and the length D3 were made into the same dimension, it is good also as a different dimension.

  Such a stamper 202 is subjected to microfabrication on the surface of the single crystal diamond tip using, for example, a focused ion beam (FIB) apparatus (manufactured by Hitachi High-Technology Co., Ltd.), and a part thereof is linearly convex. After the chip having the portion formed thereon is manufactured, it can be manufactured by performing the same processing as described above using the bite to which the chip is attached.

Here, the detailed shape of the central portion will be described.
FIG. 9 is an enlarged cross-sectional view of the range X in FIG. As shown in FIG. 9, the central portion of the inclined surface 4 includes a plurality of row portions 4 </ b> X having two linear linear convex portions 4 </ b> B (concave portions) having a 90-degree apex angle in a row. Is formed. By providing such a row portion 4X, a concave portion Z is formed between the two linear convex portions 4B. When a molded product is formed using the stamper 202 having the recesses Z, it is difficult to enter the molding resin into the recesses Z. Therefore, a stamper is formed due to the formation of voids in the deepest part of the recesses Z. There exists a tendency for the mold release property of the molded article from 202 to improve. For this reason, it is possible to improve the moldability of the molded product by deliberately providing a portion such as the concave portion Z on the slope 4 of the linear portion that is difficult for the resin to enter. However, the shape of the recess Z needs to be a shape in which an undercut portion does not occur so that when the molded product is released from the stamper 202, the release is not hindered.

  In this modification, the central portion of the slope 4 has a configuration in which a plurality of row portions 4X are formed at intervals, but there is no interval between the row portions 4X, that is, a linear convex portion 4B. It can be set as the structure which mutually continued. Even in such a configuration, since the root portion and the top portion of the linear portion are flat surfaces, it is possible to obtain a molded product with higher brightness uniformity while ensuring sufficient molding efficiency. Can be played.

  Moreover, although the row | line | column part 4X was formed only in the said center part, you may form a structure as shown in FIG. In this case, since the flat portion as described above is provided between the row portions 4X, there is an advantage that a molded product with a higher luminance uniformity can be obtained while ensuring sufficient molding efficiency. be able to.

  Further, in this modification, the configuration of the row portion 4X is a configuration in which two linear convex portions 4B are connected, but may be a shape in which three or more linear concave portions are connected. Moreover, it is good also as a structure with which the multiple types of row | line | column part was combined. For example, as shown in FIG. 10, a configuration in which a row portion 4X in which two linear convex portions 4B are continuous and a row portion 4Y in which three linear convex portions 4B are continuous is mixed. it can.

FIG. 11 is a cross-sectional view showing a stamper 203 according to a sixth modification.
As shown in FIG. 11, the stamper 203 has a configuration in which the linear convex portions 4 </ b> B are formed only on any one of the slopes 4 of the linear portions 3. The stamper 203 can be manufactured by using a cutting tool provided with the single crystal diamond tip and a cutting tool finely processed by the focused ion beam apparatus or the like.

FIG. 12 is a cross-sectional view showing a stamper 204 according to a seventh modification.
As shown in FIG. 12, the stamper 204 has a configuration in which the linear convex portion 4 </ b> B is formed only on one of the slopes 4 of each linear portion 3. The stamper 204 can be manufactured by performing the same processing as described above using a tool in which a chip that has been finely processed by the focused ion beam apparatus or the like is attached to only one surface of the single crystal diamond tool. .

  In addition, although the modification of a mold component was mentioned as a modification of this invention, the light diffusing plate obtained using the mold component which concerns on these modifications can also mention the same modification. That is, at least one main surface of the light diffusion plate according to the modification of the present invention has a shape in which the uneven structure of the mold part is sufficiently transferred. The sufficiently transferred shape is a shape having substantially the same dimensions as the concavo-convex structure of the mold part, and so on.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited to these examples.

<Example 1>
Nickel-phosphorus electroless plating having a thickness of 100 μm was applied to the entire surface of a rectangular plate made of stainless steel SUS430 having dimensions of 800 mm × 500 mm and a thickness of 2 mm. Next, a cutting tool with a 100 mm apex angle diamond chip (Sumidia DA-2200, manufactured by Sumitomo Electric Hardmetal Corp.) is attached to a machine tool for microfabrication (for example, nanogrubber AMG71P, manufactured by Fujikoshi Co., Ltd.). Using a nickel-phosphorous electroless plating surface, a linear portion having an isosceles triangular cross section having a width of 70 μm, a height of 24.5 μm, a pitch of 70 μm, and an apex angle of 100 degrees along the short side direction of the plate material. A plurality of cutting processes were performed to form an uneven structure, and a stamper was obtained.

  With respect to the obtained stamper, the Ra (max1) of the linear portion, the Ra (max2), Ra (min2), and Sm of the slope of the linear portion were determined using an ultradeep microscope. As a result, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.15 μm, Ra (max2) / Ra (max1) was 0.021. Furthermore, Ra (max2) / Ra (min2) was 7.5, and Sm was 70 μm.

Next, the resin constituting the molded product will be described.
99.7 parts by mass of a resin having an alicyclic structure (Nippon Zeon Co., Ltd., ZEONOR 1060R, water absorption 0.01%), which is a transparent resin, and a polysiloxane polymer having an average particle diameter of 2 μm as a light diffusing agent The mixture was mixed with 0.3 part by mass of fine particles made of a product, kneaded with a twin-screw extruder, extruded into a strand, and cut with a pelletizer to produce a pellet for a light diffusion plate. Using this light diffusion plate pellet as a raw material, a 100 mm × 50 mm test plate having a smooth thickness of 2 mm on both sides was formed using an injection molding machine (clamping force 1000 kN). The total light transmittance and haze of this test plate were measured using an integrating sphere type color difference turbidimeter based on JIS K7361-1 and JIS K7136. The test plate had a total light transmittance of 85% and a haze of 99%.

  Next, a mold was prepared, the stamper was attached to one mold constituting the mold, and the cavity surface of the other mold was polished. At this time, Ra of the polished surface was 0.003 μm. Using an injection molding machine having such a mold (clamping force 4,410 kN), the light diffusion plate is molded under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 85 ° C. using the light diffusion plate pellets as a raw material. did. The light diffusing plate thus obtained did not stick to the stamper even after 100 shots of injection molding.

  The obtained light diffusing plate has a rectangular shape with a thickness of 2 mm and 727.5 mm × 415 mm to which the uneven structure of the stamper is sufficiently transferred, and a linear prism having a triangular cross section is substantially parallel to one surface thereof. A plurality of prism rows were formed. This linear prism had an apex angle of 100 ° and a pitch of 70 μm. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole.

  Next, a reflective sheet (manufactured by Tsujiden Co., Ltd., RF188) is attached to the inner surface of a milky white plastic case having an inner width of 700 mm, a depth of 400 mm, and a depth of 20 mm to form a reflector, and 5 mm away from the bottom of the reflector, Twelve cold-cathode tubes having a diameter of 3 mm and a length of 750 mm were arranged so that the distance between the centers of the cold-cathode tubes was 33 mm, the vicinity of the electrodes was fixed with a silicone sealant, and an inverter was attached.

  Next, the obtained light diffusing plate was placed so that the prism row was on the opposite side (the opposite light source position) of the cold cathode tube, and was placed on a plastic case to which the cold cathode tube was attached. At this time, the cold cathode tubes were arranged so that the longitudinal direction of the cold cathode tubes and the longitudinal direction of the triangular prisms constituting the prism row were substantially parallel. Further, three diffusion sheets (“188GM3”, manufactured by Kimoto Co., Ltd.) were installed on the light diffusion plate. In this way, as shown in FIG. 6, a direct type backlight device 100 having a plurality of light sources 101, a reflecting plate 102, and the light diffusing plate 1 was produced.

Next, a cold cathode tube is turned on by applying a tube current of 5 mA to the obtained direct type backlight, and using a two-dimensional color distribution measuring device, 100 front faces are equally spaced on the center line in the short direction. The luminance in the direction was measured, and a luminance average value La and luminance unevenness Lu were obtained according to the following formulas 1 and 2. At this time, the luminance average value was 6,879 cd / m ² and the luminance unevenness was 0.4%.
Luminance average value La = (L1 + L2) / 2 (Formula 1)
Luminance unevenness Lu = ((L1-L2) / La) × 100 (Formula 2)
L1: Average luminance maximum value just above a plurality of cold-cathode tubes installed L2: Average minimum value sandwiched between maximum values Note that luminance unevenness is an index indicating luminance uniformity, and luminance unevenness When it is bad, the figure increases.

<Example 2>
A light diffusing plate and a direct type backlight device were obtained in the same manner as in Example 1 except that the cavity surface of the other mold was roughened by grinding treatment along the longitudinal direction. As a result, Ra of the roughened surface was 0.6 μm. The obtained light diffusing plate has the uneven structure of the stamper sufficiently transferred, and the surface on which the prism row is formed has the same shape as in Example 1 (however, the light diffusing plate has the unevenness of the linear concave portion. In other words, the surface on which the prism array was not formed was roughened as compared with Example 1. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole. The obtained light diffusing plate never stuck to the stamper even after 100 shots of injection molding. Further, in the obtained direct type backlight device, the luminance average value was 6,810 cd / m ² and the luminance unevenness was 0.5%.

<Example 3>
Nickel-phosphorus electroless plating having a thickness of 100 μm was applied to the entire surface of a rectangular plate made of stainless steel SUS430 having dimensions of 800 mm × 500 mm and a thickness of 2 mm. Next, a bit on which a sintered diamond tip (Sumidia DA-2200, manufactured by Sumitomo Electric Hardmetal Corp.) with an apex angle of 100 degrees and a single crystal diamond chip with an apex angle of 100 degrees (Contool Fine Tooling) are attached. Using a tool with a micro-machining tool (for example, Nanogruber AMG71P, manufactured by Fujikoshi Co., Ltd.), replacing the tool with a tool attached to the tool with the tool attached to the nickel-phosphorus electroless plating surface in the short-side direction of the plate material A plurality of linear portions having an isosceles cross section with a width of 70 μm, a height of 24.5 μm, a pitch of 70 μm, and an apex angle of 100 degrees were cut to form a concavo-convex structure to obtain a stamper. Specifically, a plurality of linear portions are formed by a first linear portion formed by a cutting tool to which a sintered diamond tip is attached and a second linear portion formed by a cutting tool to which a single crystal diamond tip is attached. It was set as the structure which repeats a linear part and a said 2nd linear part in this order.

  With respect to the obtained stamper, Ra (max1) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the first linear portion were obtained using an ultradeep microscope. As a result, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.15 μm, Ra (max2) / Ra (max1) was 0.021. Furthermore, Ra (max2) / Ra (min2) was 7.5, and Sm was 70 μm.

  While attaching such a stamper to one mold, and using a roughened cavity surface of the other mold in the same manner as in the second embodiment, light diffusion as a molded product is performed in the same manner as in the first embodiment. A plate and a direct backlight device were obtained.

In the obtained light diffusing plate, the concavo-convex structure of the stamper was sufficiently transferred, and the surface on which the prism row was formed had a shape similar to the shape of the mold part shown in FIG. Then, the first linear portion and the second linear portion are repeatedly formed, which is different from the present embodiment). Further, since the linear convex portion of the stamper is transferred, the concave and convex portions are reversed in the light diffusion plate). Further, as in Example 2, the surface on which the prism rows were not formed was roughened, and the Ra of the roughened surface was 0.6 μm. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole. The obtained light diffusing plate stuck to the stamper only once when injection molding was performed for 100 shots, but this did not cause a significant hindrance to moldability. In the obtained direct type backlight device, the average luminance was 6,878 cd / m ² and the luminance unevenness was 0.3%.

<Example 4>
Nickel-phosphorus electroless plating having a thickness of 100 μm was applied to the entire surface of a rectangular plate made of stainless steel SUS430 having dimensions of 800 mm × 500 mm and a thickness of 2 mm. Next, fine processing is performed on the surface of a single crystal diamond tip (manufactured by Contool Fine Tooling) with an apex angle of 100 degrees using a focused ion beam (FIB) apparatus (manufactured by Hitachi High-Technology Corporation). Then, a finely processed chip was produced. This chip was attached to a cutting tool to prepare a cutting tool to which a micromachined chip was mounted.

  Using a tool with such a micromachined chip attached to a machine tool for micromachining (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.), the short side direction of the plate material with respect to the nickel-phosphorous electroless plating surface A plurality of linear portions having an isosceles triangular cross section with a width of 70 μm, a height of 24.5 μm, a pitch of 70 μm, and an apex angle of 100 degrees were formed to form a concavo-convex structure to obtain a stamper.

  With respect to the obtained stamper, Ra (max1) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the linear portion were determined using an ultra-deep microscope. As a result, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.1 μm, Ra (max2) / Ra (max1) was 0.014. Furthermore, Ra (max2) / Ra (min2) was 5.0, and Sm was 70 μm. In FIG. 8, the lengths D1 and D3 were 4.6 μm, and the length D2 was 36.5 μm. Moreover, in FIG. 9, the length of the bottom side of the linear convex portion 4B was 0.5 μm, and the interval between the row portions 4X was 1.0 μm.

  While attaching such a stamper to one mold, and using a roughened cavity surface of the other mold in the same manner as in the second embodiment, light diffusion as a molded product is performed in the same manner as in the first embodiment. A plate and a direct backlight device were obtained.

In the obtained light diffusion plate, the uneven structure of the stamper was sufficiently transferred, and the surface on which the prism array was formed had a shape similar to the shape shown in FIG. Is transferred, so that the unevenness is reversed in the light diffusion plate). Further, as in Example 2, the surface on which the prism rows were not formed was roughened, and the Ra of the roughened surface was 0.6 μm. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole. The obtained light diffusion plate did not stick to the stamper even after 100 shots of injection molding. In the obtained direct type backlight device, the average luminance value was 6,946 cd / m ² and the luminance unevenness was 0.3%.

<Example 5>
A machine tool for microfabrication (for example, for example, while exchanging the tool with the single-crystal diamond chip with the apex angle of 100 degrees as appropriate with the tool with the micromachined chip manufactured in Example 4 attached thereto. Nano Gruber AMG71P (Fujikoshi Co., Ltd.) and a nickel-phosphorus electroless plating surface with a width of 70 μm, height of 24.5 μm, pitch of 70 μm and apex angle of 100 degrees along the short side direction of the plate. A stamper was obtained by cutting a plurality of equilateral triangular linear portions to form a concavo-convex structure. Specifically, as in Example 3, a plurality of linear portions are divided into a third linear portion formed by a cutting tool to which a finely processed chip is attached, and a cutting tool to which a single crystal diamond chip is attached. The fourth linear part formed by the above and the fourth linear part are repeated in this order.

  With respect to the obtained stamper, Ra (max1) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the third linear portion were determined using an ultradeep microscope. As a result, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.1 μm, Ra (max2) / Ra (max1) was 0.014. Furthermore, Ra (max2) / Ra (min2) was 5.0, and Sm was 70 μm.

  While attaching such a stamper to one mold, and using a roughened cavity surface of the other mold in the same manner as in the second embodiment, light diffusion as a molded product is performed in the same manner as in the first embodiment. A plate and a direct backlight device were obtained.

In the obtained light diffusion plate, the uneven structure of the stamper was sufficiently transferred, and the surface on which the prism row was formed had a shape similar to the shape of the stamper shown in FIG. 11 (in FIG. 11, The third linear portion and the fourth linear portion are repeatedly formed, which is different from that of the present embodiment, and also because the linear convex portion of the stamper is transferred, the light diffusion On the board, the irregularities are reversed). Further, as in Example 2, the surface on which the prism rows were not formed was roughened, and the Ra of the roughened surface was 0.6 μm. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole. The obtained light diffusing plate stuck to the stamper only once when injection molding was performed for 100 shots, but this did not cause a significant hindrance to moldability. In the obtained direct type backlight device, the average luminance was 7,016 cd / m ² and the luminance unevenness was 0.2%.

<Example 6>
Nickel-phosphorus electroless plating having a thickness of 100 μm was applied to the entire surface of a rectangular plate made of stainless steel SUS430 having dimensions of 800 mm × 500 mm and a thickness of 2 mm. Next, a focused ion beam (FIB) apparatus (manufactured by Hitachi High-Technology Corporation) is used only on one of the surfaces of a single crystal diamond tip (manufactured by Contool Fine Tooling) having an apex angle of 100 degrees. Then, the same microfabrication as that of one surface of the micromachined chip of Example 4 was performed to produce the micromachined chip 2. This chip was attached to a cutting tool to produce a cutting tool to which the micro-processed chip 2 was mounted.

  Using such a tool with the micro-processed chip 2 attached to a machine tool for micro-processing (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.), the short side of the plate material with respect to the nickel-phosphorus electroless plating surface A stamper was obtained by cutting a plurality of linear parts having an isosceles triangular shape with a width of 70 μm, a height of 24.5 μm, a pitch of 70 μm, and an apex angle of 100 degrees along the direction to form an uneven structure.

  For the obtained stamper, the Ra (max1) of the linear portion, the Ra (max2), Ra (min2), and Sm of the inclined surface on which the linear convex portion was formed were determined using an ultra-deep microscope. As a result, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.1 μm, Ra (max2) / Ra (max1) was 0.014. Furthermore, Ra (max2) / Ra (min2) was 5.0, and Sm was 70 μm.

  While attaching such a stamper to one mold, and using a roughened cavity surface of the other mold in the same manner as in the second embodiment, light diffusion as a molded product is performed in the same manner as in the first embodiment. A plate and a direct backlight device were obtained.

In the obtained light diffusion plate, the uneven structure of the stamper was sufficiently transferred, and the surface on which the prism array was formed had a shape similar to the shape shown in FIG. 12 (note that the linear protrusions of the stamper) Is transferred, so that the unevenness is reversed in the light diffusion plate). Further, as in Example 2, the surface on which the prism rows were not formed was roughened, and the Ra of the roughened surface was 0.6 μm. In addition, although the several uneven | corrugated | grooved part formed in the plane of the uneven | corrugated structure in a stamper was partially transferred, it was not transferred very much as a whole. The obtained light diffusion plate did not stick to the stamper even after 100 shots of injection molding. In the obtained direct type backlight device, the luminance average value was 6,981 cd / m ² and the luminance unevenness was 0.2%.

<Comparative Example 1>
A light diffusing plate and a direct type backlight device were obtained in the same manner as in Example 1 except that the diamond chip of the sintered body was replaced with a single crystal diamond chip (manufactured by Contool Fine Tooling). As a result, in the mold part, Ra (max1) was 7.1 μm. Further, since Ra (max2) was 0.003 μm, Ra (max2) / Ra (max1) was 0.00042. Furthermore, Ra (max2) / Ra (min2) was 6.0, and Sm was 70 μm. The obtained light diffusion plate had a shape in which the uneven structure of the mold part was sufficiently transferred. The light diffusing plate obtained by using such mold parts was stuck to the stamper in all 100 shots when injection molding was performed 100 shots. In the obtained direct type backlight device, the luminance average value was 6,948 cd / m ² and the luminance unevenness was 1.6%.

<Comparative example 2>
A light diffusing plate and a direct type backlight device were obtained in the same manner as in Example 1 except that the surface of the single crystal diamond chip was roughened by grinding. As a result, in the mold part, Ra (max1) was 7.1 μm. Moreover, since Ra (max2) was 5.0 μm, Ra (max2) / Ra (max1) was 0.7. Furthermore, Ra (max2) / Ra (min2) was 7.5, and Sm was 70 μm. The obtained light diffusion plate had a shape in which the uneven structure of the mold part was sufficiently transferred. The light diffusing plate obtained using such a mold part never sticks to the stamper even after 100 shots of injection molding. In the obtained direct type backlight device, the average luminance was 6,470 cd / m ² and the luminance unevenness was 4.8%.

<Comparative Example 3>
A mold part was produced in the same manner as in Comparative Example 2, except that the concavo-convex structure of the mold part obtained in Comparative Example 2 was subjected to blasting to roughen the surface. Using such mold parts, a light diffusion plate and a direct type backlight device were obtained. As a result, in the mold part, Ra (max1) was 7.1 μm. Further, since Ra (max2) is 3.0 μm, Ra (max2) / Ra (max1) was 0.42. Furthermore, Ra (max2) / Ra (min2) was 1.2, and Sm was 70 μm. The obtained light diffusion plate had a shape in which the uneven structure of the mold part was sufficiently transferred. The light diffusing plate obtained using such a mold part never sticks to the stamper even after 100 shots of injection molding. In the obtained direct type backlight device, the average luminance value was 6,600 cd / m ² and the luminance unevenness was 3.6%.

  The results of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1 and Table 2, respectively.

  In Table 1, the moldability is a value indicating how many times the flat molded product has stuck to the stamper when 100 shots of injection molding are performed.

  As shown in Table 1, in Examples 1 and 2, it was found that the moldability (mold release property) was excellent and the luminance and luminance unevenness were both good. Further, as shown in Examples 1 and 2, it can be seen that the surface of the mold opposite to the mold provided with the stamper may be a polished surface or a rough surface. Moreover, also in Examples 3-6, it turned out that a moldability (mold release property) is fully excellent, and brightness | luminance and brightness nonuniformity are also favorable.

  As shown in Comparative Example 1, it was found that when the uneven portion is not formed on the surface of each surface of the uneven structure, the moldability is insufficient and uneven brightness occurs. In addition, as shown in Comparative Example 2, it was found that when uneven portions having a predetermined size or more were formed on the surface of each surface of the uneven structure, the luminance unevenness was increased. Furthermore, as shown in Comparative Example 3, it was found that when uneven (non-anisotropic) uneven portions are formed on the surface of each surface of the uneven structure, the luminance unevenness increases.

Claims (14)

A mold part for forming a resin-made flat plate molding used for an optical part,
Having a cavity surface for forming the surface of the flat molded article,
The cavity surface has a concavo-convex structure having a maximum centerline average roughness Ra (max1) measured in a direction in which the centerline average roughness Ra is maximum on the cavity surface, from 3.0 μm to 1,000 μm,
The concavo-convex structure comprises a plurality of concave or convex structural units having two or more planes as repeating units,
Of the two or more planes of the structural unit, at least one plane includes a plurality of uneven portions,
In the plane having these uneven portions, the maximum centerline average roughness Ra (max2) measured in the direction in which the centerline average roughness Ra on the plane is maximum is between the Ra (max1) and 0.5> Ra (max2) / Ra (max1)> 0.002 is satisfied, and the minimum centerline average roughness Ra measured in a direction in which the centerline average roughness Ra on the plane is minimized A mold part satisfying the relationship 2 of Ra (max2) / Ra (min2)> 1.5 between (min2) and (min2). The mold part according to claim 1,
When the Ra (max2) is measured in the same direction as the measured direction, the average interval Sm between the adjacent concavo-convex parts is between Ra (max1) and Ra (max1) × 10>Sm> Ra. A mold part satisfying the relationship 3 of (max1) × 0.001. The mold part according to claim 1,
The structural unit is a linear portion having a polygonal cross section extending linearly,
The mold part according to claim 1, wherein the concavo-convex structure includes a plurality of the linear portions arranged substantially parallel to each other. The mold part according to claim 3,
The linear portion has a triangular cross-sectional shape with an apex angle of 60 ° to 170 °, and a distance between a linear portion and a linear portion adjacent to the linear portion is 20 μm to 700 μm. Characteristic mold part. The mold part according to claim 3,
The linear portion has four or more planes;
At least two of the four or more planes are inclined to one side with respect to the thickness direction of the mold part,
The mold part characterized in that a plane other than the at least two planes is inclined to the opposite side to the at least two planes. The mold part according to claim 3,
The linear portion has a triangular cross-section,
The angle between one of the two planes constituting the triangle and the plane perpendicular to the thickness direction of the mold part is the other of the two planes constituting the triangle and the thickness direction of the mold part. Equal to the angle between the plane perpendicular to
The angle is between a certain X point and a Y point that is a predetermined distance away from the X point in a direction orthogonal to the longitudinal direction of the linear portion, and as the distance from the X point and the Y point increases. Mold parts that grow continuously or stepwise. The mold part according to claim 1,
The mold part is a mold part having a convex structure or a concave structure having three or more planes. The mold part according to claim 7,
The mold part, wherein the convex structure or the concave structure having three or more planes is a pyramid or a truncated pyramid. The mold part according to claim 7,
The structural unit is a convex structure having three or more planes,
The convex structure is obtained by forming a linear portion having a polygonal cross-section extending in a linear shape, and then inserting a V-shaped cut into the linear portion in a direction different from the longitudinal direction of the linear portion. Is mold parts. The mold part according to claim 7,
The structural unit is a concave structure having three or more planes,
The concave structure is obtained by forming a linear portion having a polygonal cross section extending in a linear shape, and then making a V-shaped cut in the linear portion in a direction different from the longitudinal direction of the linear portion. A mold part obtained by transferring the convex shape of a transfer member having a shape. The mold part according to claim 1,
The mold part, wherein the uneven portion is formed on a plane of a part of the plurality of structural units. The mold part according to claim 1,
The mold part is characterized in that the uneven part is formed only on a part of the two or more planes constituting the structural unit. The mold part according to claim 1,
The mold part, wherein the concavo-convex part is formed only on a part of the plane constituting the structural unit. A flat molded product for an optical component obtained by injection molding using the mold component according to claim 1,
A prism structure having a maximum center line average roughness Ra (Dmax1) of 3.0 μm to 1,000 μm measured on at least one main surface in a direction in which the center line average roughness Ra is maximum on the main surface Have
Each of the plurality of prism portions constituting this prism structure has two or more surfaces,
The surface of each surface of the prism portion has a maximum centerline average roughness Ra (Dmax2) measured in a direction in which the centerline average roughness Ra on the surface is maximum, between the Ra (Dmax1) and 0.5> Ra (Dmax2) / Ra (Dmax2)> 0.002 is satisfied, and the minimum centerline average roughness Ra (measured in the direction in which the centerline average roughness Ra on the surface is minimized) Dmin2) is a concavo-convex surface satisfying the relationship of Ra (Dmax2) / Ra (Dmin2)> 1.5.

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