WO2007077737A1

WO2007077737A1 - Mold part and molded flat-plate product

Info

Publication number: WO2007077737A1
Application number: PCT/JP2006/325377
Authority: WO
Inventors: Keisuke Tsukada; Kazunori Ueki
Original assignee: Zeon Corporation
Priority date: 2005-12-28
Filing date: 2006-12-20
Publication date: 2007-07-12
Also published as: TW200740595A; JPWO2007077737A1

Abstract

A mold part capable of efficiently molding a molded flat-plate product with excellent optical performance. In the mold part, irregular surface structures with a maximum centerline average roughness Ra (max1) of 3.0 to 1000 μm are formed on a cavity surface for forming the surface of the molded flat-plate product. Each irregular surface structure has a groove or ridge structure unit with two or more flat surfaces. Grooves and ridges are formed on each flat surface of the structure unit. On each flat surface with the grooves and ridges, the maximum centerline average roughness Ra (max2) has the relation of 0.5 > Ra (max2)/Ra (max1) > 0.002 relative to Ra (max1) and has the relation of Ra (max2)/Ra (min2) > 1.5 relative to the minimum centerline average roughness Ra (min2).

Description

Mold parts and flat plate molded products

Technical field

TECHNICAL FIELD [0001] The present invention relates to a mold part, and more particularly to a mold part capable of efficiently molding a molded product having excellent optical performance.

Background art

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 and 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 is a rough surface having a 10-point average roughness Rz of 0.2 to 3.0 μm, so It is disclosed to improve releasability.

Disclosure of the invention

Problems to be solved by the invention

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

[0004] The inventors of the present invention have provided 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 in parallel with the longitudinal direction of the light source. It has already been found that the degree can be increased (Japanese Patent Application No. 2004-243479 (Japanese Patent Application Laid-Open No. 2006-666074)). Such a light diffusing plate can be obtained by forming a concavo-convex structure corresponding to the prism row on the cavity surface of the 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.

[0005] Therefore, by using the technique shown in Patent Document 1 described above, light diffusion having a prism array. Although it is conceivable to roughen the cavity surface of the mold that forms the plate, simply applying this technology can improve the releasability of the molded product, but it will provide sufficient optical performance such as brightness uniformity. There was a case that could not be demonstrated.

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.

[0006] An object of the present invention is to provide a mold part capable of efficiently forming a flat molded article having excellent optical performance.

Means for solving the problem

[0007] As a result of intensive studies to solve the above problems, the present inventors have provided a predetermined concavo-convex portion on each surface of a concave or convex structural unit for forming a pattern portion in a flat plate molded product, It was found that a mold part capable of easily molding a molded article having sufficient optical performance was obtained, and the present invention was completed based on this knowledge.

[0008] The present invention is a mold part for forming a resin-made flat plate molded product used for an optical component, and has a cavity surface for forming the surface of the flat plate molded product, The cavity surface has a concavo-convex structure with a maximum center line average roughness Ra (maxl) measured in the direction in which the center line average roughness Ra is maximum on the cavity surface being 3.0 / ζ πι to 1,000 m. The concavo-convex structure includes a plurality of concave or convex structural units having two or more planes as repeating units, and at least one of the two or more planes of the structural units is a plurality of In the plane having these irregularities, the maximum centerline average roughness Ra (max2) force measured in the direction in which the centerline average roughness Ra on the plane is maximized Ra (ma xl ) And 0.5> Ra (max2) / Ra (maxl)> 0.002 satisfy the relationship 1 and the centerline average on the plane Between the minimum center line average roughness Ra (min 2) measured in the direction in which the roughness Ra is minimized, the relationship 2 of Ra (max2) ZRa (min2)> l.5 is satisfied. The mold part includes a stamper provided on the mold in addition to the mold itself.

[0009] Here, in the mold part, when the Ra (max2) is measured in the same direction as the measurement direction, the average interval Sm between the adjacent concavo-convex parts is the Ra (maxl) In the meantime, the relationship 3 of Ra (maxl) X 10>Sm> Ra (maxl) X O.001 may be satisfied. [0010] The structural unit may be a linear portion having a polygonal cross section extending in a linear shape, and the concavo-convex structure may be configured such that a plurality of the linear portions are arranged substantially parallel to each other. On this occasion

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 m to 700 m. It can be configured. For convenience of explanation, the term “polygon” refers to the open path composed of line segments in the cross-sectional plain corresponding to each concave or convex portion of the linear portion. ). Then, according to the number of sides or points of the closed path obtained by connecting both ends of the open path, they are called corresponding to the polygon (which usually means).

[0011] The linear portion has four or more planes, and at least two of the four or more planes are on one side with respect to the thickness direction of the mold part. The plane other than the at least two planes may be inclined to the opposite side of the at least two planes.

[0012] The linear portion has a triangular cross section, and an angle formed by one of two planes constituting the triangle and a plane perpendicular to the thickness direction of the mold part constitutes the triangle. The angle equal to the angle formed between the other of the two planes formed and the plane perpendicular to the thickness direction of the mold part is defined as a specific X point and the linear portion from the X point. A configuration may be adopted that increases continuously or stepwise from the point X and the point Y away from the point Y along a direction perpendicular to the longitudinal direction. Here, the angle formed between each of the two slopes and the surface perpendicular to the thickness direction of the mold part is “equal” when the difference between the angles is within 1 °.

[0013] 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 three or more planes may be a pyramid or a truncated pyramid.

[0014] 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 linearly, It can be obtained by making a V-shaped cut in a direction different from the longitudinal direction of the linear part. [0015] Further, 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 It may be obtained by transferring the convex shape of a transfer member having a convex shape obtained by making a V-shaped cut in a direction different from the longitudinal direction of the linear portion.

[0016] Further, the concavo-convex portion may be formed on a plane of a part of the plurality of structural units.

[0017] Further, the uneven portion may be formed only on a part of the two or more planes constituting the structural unit. As such a configuration, for example, when the structural unit is a triangular section and is a linear portion, a configuration in which the concavo-convex portion is formed only on one of the two exposed flat surfaces can be exemplified.

[0018] Further, the concavo-convex portion may be formed only on a part of the plane constituting the 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 mentioned.

[0019] 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 for producing a flat resin molded product made of resin used for optical parts by injection molding using the mold parts.

The invention's effect

[0020] According to the present invention, an uneven structure having a maximum center line average roughness Ra (maxl) measured in a direction in which Ra is maximum on the cavity surface is 3. O / zm to: L, 000 m. On the surface, between the maximum center line average roughness Ra (max x2) measured in the direction where Ra is maximum on the plane of the structural unit and Ra (maxl), 0.5> Ra (max2) / Ra (maxl)> 0.002 Relationship 1 is satisfied, and the minimum center line average roughness Ra (min2) measured in the direction in which Ra is minimized on the plane of the structural unit, Ra (max2) ZRa ( min2)> 1.5 By providing the concave and convex portions that satisfy 2 above, there is an effect that a flat molded product having excellent optical performance can be efficiently molded.

Brief Description of Drawings

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 cross-sectional view schematically showing a mold part according to a 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 a 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 a 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.

BEST MODE FOR CARRYING OUT THE 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 diagram partially showing a cross section along the thickness direction of the stamper 1. The stamper 1 is a member for forming a resin-made flat plate molded product used for optical components. Examples of the molded plate product include optical components such as a light diffusion plate, a light guide plate, and a reflection plate.

[0023] Here, as the resin constituting the flat plate molded article, a transparent resin can be used from the viewpoint of reducing the luminance. 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 Standards JIS K7361-KIS01346 8- 1). Propylene-ethylene copolymer, polypropylene, polystyrene, aromatic butyl monomer and (meth) acrylic having lower alkyl group Examples thereof include copolymers with acid alkyl esters, polyethylene terephthalate, terephthalic acid-ethylene glycol-cyclohexane dimethanol copolymer, polycarbonate, acrylic resin, and resin having an alicyclic structure. In addition, (meth) acrylic acid is acrylic acid and methacrylic acid.

[0024] Further, as the resin, a resin obtained by adding a light diffusing agent to the transparent resin may be used. A 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 inorganic fillers include silica, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, and mixtures thereof. Examples of the organic filler include acrylic resin, polyurethane, polyvinyl chloride, polystyrene resin, polyacrylonitrile, polyamide, polysiloxane resin, melamine resin, and benzoguanamine resin.

[0025] The stamper 1 is disposed at a position corresponding to the cavity surface of the injection mold. In this embodiment, the mold part of the present invention is used as a stamper. However, 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 its 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 parallel to 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 slopes (planes) 4 and a convex section. The apex angle 0 of the linear portion 3 is 60 ° to 170 °, preferably 70 ° to 160 °. The width dimension of the bottom edge of the wire rod is 20 μm to 700 μm, preferably 30 μm to 600 μm. The height H of the linear portion 3 is 0.9 m to 606 μm, preferably 2.6 μm to 428 μm. The cross-sectional shape of the linear part 3 is preferably an isosceles triangle in that the optical performance of the molded flat product is improved. Further, the interval (pitch) P between adjacent linear portions 3 is 20 μm to 700 μm, preferably 30 μm to 600 μm. The interval between the linear ridges is the distance between the vertices of the adjacent linear portions.

[0028] In such a concavo-convex structure 2 composed of a plurality of linear portions 3, the maximum center line average roughness Ra (maxl) measured in the A direction, which is a direction perpendicular to the thickness direction of the stamper 1, is 3 O ^ m to 1,000 [mu] m, preferably 4.0 [mu] m to 900 [mu] m. The A direction force R The direction in which a is the maximum. The centerline average roughness Ra can be obtained based on JIS B0601.

[0029] On the surface of each inclined surface 4 of the linear portion 3, a plurality of linear concave portions 4A that are uneven portions are formed. The linear recess 4A extends substantially parallel to the longitudinal direction of the linear portion 3 (the direction perpendicular to the paper surface of FIG. 2). These linear recesses 4A are substantially parallel to each other. In Slope 4, between the maximum centerline average roughness Ra (max 2) measured along the B direction and C direction, which are the directions along Slope 4A in the figure, and Ra (maxl) is 0. The relation 1 of 5> Ra (max2) / Ra (maxl)> 0.002 is satisfied. The B direction and the C direction are directions in which Ra is maximum.

[0030] In addition, on the surface of the slope 4 where the linear recess 4A is formed, the distance between the minimum center line average roughness Ra (min2) measured in the longitudinal direction of the linear recess 4A and Ra (max2). In addition, the relation 2 of Ra (max2) ZRa (min2)> 2 is satisfied. Note that this is the direction in which the longitudinal force Ra of the linear recess 4A is minimized.

[0031] In addition, the average interval Sm between adjacent linear recesses 4A measured in the B direction and the C direction is between Ra (maxl) and Ra (maxl) X 10> Sm> Ra ( maxl) It is preferable to satisfy the relationship of X O. 001 Ra (maxl) X 9> Sm> Ra (maxl) It is preferable to satisfy the relationship of X O. 002! / ,.

[0032] The stamper 1 as described above is manufactured, for example, as follows.

First, a nickel-phosphorus electroless plating layer having a thickness of, for example, about 100 / zm is applied to the entire surface of a metal rectangular plate. Next, using a machine tool for fine processing (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.) equipped with a sintered diamond bit having a predetermined apex angle on the surface of this plating layer, it is placed on the longitudinal side of the plate material. 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 along. 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 4A are formed on the inclined surface 4 of the linear part 3 along the longitudinal direction of the linear part 3 due to the uneven part of the sintered diamond bite. The stamper 1 is manufactured as described above.

[0033] By arranging the stamper 1 produced in this way so that the surface on which the concavo-convex structure 2 is formed becomes the cavity surface of the injection mold, and injection molding using the above-mentioned resin, An optical component which is a flat plate molded product such as a light diffusion plate can be molded.

[0034] 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 described above. Since the molding resin does not easily enter the fine linear recess 4A, the flat molded product can be easily released from the stamper 1 due to the possibility of a gap 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 array 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 flat 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, sufficient luminance is maintained and luminance unevenness is small ( A device having a light-emitting surface with a high luminance uniformity can be obtained. Therefore, the obtained flat plate molded article has sufficient optical performance. As described above, according to the present embodiment, there is an effect that a flat molded product having excellent optical performance can be efficiently molded.

[0035] The flat plate molded product obtained by the stamper 1 is transferred to at least one main surface of the uneven structure 2 of the stamper 1, so that the prism row is formed on the flat plate 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, but if the releasability between the flat plate molded product and the mold part is taken into consideration, the linear shape It is preferable that the uneven structure corresponding to the portion 3 is not transferred so much and at least the transferred portion is in a partial range. In addition, the flat plate molded product of this embodiment is a light diffusing plate.

[0036] 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 °. In addition, the width of the base portion of the triangle is generally 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. The interval (pitch) between adjacent triangles is usually 20 π! ˜700 m, preferably 30 μm to 600 μm.

[0037] In such a prism array having a plurality of linear prisms, the maximum center line average roughness Ra (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 Ra ( Dmaxl) force ^ 3.0 / ζ πι ~ 1,000 m, preferably 4.0 / ζ πι ~ 900 μm. This direction is the direction where Ra is maximum.

[0038] 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 uneven surface, between the maximum center line average roughness Ra (Dmax2) measured in a direction parallel to the inclined surface and including a direction perpendicular to the longitudinal direction of the linear prism, and Ra (Dmaxl), The relationship 0.5> Ra (Dmax2) / Ra (Dmaxl)> 0.002 is satisfied. The direction including the direction parallel to the slope and perpendicular to the longitudinal direction of the linear prism is the direction in which Ra is maximum.

[0039] Further, in the uneven surface, 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) Ra (Dmax2) / Ra (Dmin2)> l. 5 is satisfied. The direction parallel to the slope and including the longitudinal direction of the linear prism is the direction in which Ra is minimized.

[0040] The average distance Sm (D) of the portion corresponding to the linear recess 4A measured in the direction along the concavo-convex surface is between Ra (Dmaxl) and Ra (Dmaxl) X 10 It is preferable to satisfy the relationship> Sm (D)> Ra (Dmaxl) X O. 001 Ra (Dmaxl) X 9> Sm (D)> Ra (Dmaxl) X O. 002 More preferably.

[0041] <Modification>

In addition, this invention is not limited to the said embodiment.

For example, in the above-described embodiment, the concavo-convex part of the slope 4 of the linear part 3 may be a linear convex part (linear convex part) with the linear concave part 4A, or the linear concave part and the linear convex part It is good also as a structure which has both. In addition, the slope 4 has a force that forms a plurality of linear recesses 4A so as to be substantially parallel to the longitudinal direction of the linear portion 3. The plurality of linear recesses 4A 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.

In the embodiment, the linear portion 3 has a triangular cross section, but may have a polygonal shape other than the 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 present. Surfaces 11, 12 and other two surfaces 13, 14 and force Stampers 1 are perpendicular to each other in a direction perpendicular to the thickness direction (including the horizontal direction in the figure and perpendicular to the paper) It is good also as an inclined structure. By configuring a direct type backlight device using a light diffusing plate formed using a stamper having such a configuration and a plurality of light sources, the luminance and luminance uniformity of the light emitting surface can be increased. Therefore, the light diffusing plate has sufficient optical performance.

[0043] In the above embodiment, the apex angles Θ of the linear portions 3 are all the same, but the apex angles Θ may be different. For example, the angle formed between one of the two planes constituting the cross-sectional triangle of the linear portion and the plane orthogonal to the thickness direction of the mold part is the other of the two planes constituting the triangle and the plane The angle equal to the angle formed with the surface orthogonal to the thickness direction of the mold part is a predetermined X point and a predetermined distance away from this X point along the direction orthogonal to the longitudinal direction of the linear portion. Further, 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 between 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 continuously increases as the distance from the point X and the point Y increases from X to the point Y that is a predetermined distance along the direction perpendicular to the longitudinal direction of the linear portion 3 (the horizontal direction in the figure). Or you can make it smaller in steps! / ヽ. By configuring a direct type backlight device by arranging a light source at positions corresponding to the point X and the point Y of the light diffusing plate formed using the stamper having such a configuration, the luminance and luminance of the light emitting surface are configured. The uniformity can be increased. Therefore, the light diffusing plate has sufficient optical performance.

[0044] In the embodiment, the concavo-convex structure 2 may be a convex structure or a concave structure having three or more surfaces. As the concave structure or convex structure having three or more surfaces, for example, a polygonal pyramid such as a quadrangular pyramid as shown in FIG. By constructing a direct type 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 the luminance uniformity of the light emitting surface are increased. Can do. Therefore, the light diffusing plate has sufficient optical performance.

[0045] In the convex structure having three or more surfaces, after forming a linear portion having a polygonal shape having a concave or convex cross section, a direction different from the longitudinal direction of the linear portion is formed on the linear portion. It can be formed with V-shaped cuts. [0046] Further, the concave structure having three or more surfaces, for example, as shown in the embodiment, after forming a linear part having a polygonal force having a concave or convex cross section, the linear part is formed on the linear part. And forming 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 linear portion, and transferring the convex shape of the transfer member. Can do.

[0047] 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 present invention also includes a configuration in which a flat surface (mirror-like shape) without the linear concave portion 4A is provided on a part of the entire slope 4 of the plurality of linear portions 3. Providing a part of the flat surface in this way has 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 4A is formed only on the inclined surface 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 each of the slopes 4 of the plurality of linear parts 3 has a linear convex part (uneven part) 4B 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 on 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 convex portion 4B only at the central portion, there is an advantage that the processing of the linear portion 3 can be facilitated.

[0050] As shown in FIG. 8, the range of the central portion is defined as a length in the direction along each slope 4 being D, and this length D is applied from the root side to the top side of the linear portion 3 3 If the length of each region is D1, D2, and D3 in the above order, for example, the length D2 is 1% to 98% of the length D, and the length D1 is 1% to 1% of the length D. 98%, length D3 can be 1% to 98% of length D. Also, length D2 is 5% to 90% of length D, length D1 is 5% to 90% of length D, length D3 is length D 5% to 90% is preferable. 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 force is 5, the lengths D1 and D3 can be 4.6 m and the length D2 can be 36.5 μm, respectively. It should be noted that the length D2 and the length D3 may be the same size but different forces.

[0051] Such a stamper 202 performs fine processing on the surface of the single crystal diamond tip using, for example, a focused ion beam (FIB) apparatus (manufactured by Hitachi High-Technologies Corporation) V. Then, after a chip having a linear convex portion formed in part is manufactured, the same processing as described above is performed using a bite to which this chip is attached.

[0052] 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 slope 4 has a plurality of row portions 4X each having a series of two linear line-shaped convex portions 4B (concave portions) having a cross section of 90 ° in apex. 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 recess Z, it is difficult to enter the molding resin into the recess Z, and therefore, a void is formed in the deepest portion of the recess Z. Therefore, there is a tendency that the release property of the molded product from the stamper 202 is improved. For this reason, it is possible to improve the moldability of the molded product by providing the slope 4 of the linear portion with a portion such as the recess Z that is difficult for the resin to enter. However, the shape of the recess Z must be such that when the molded product is released from the stamper 202, the undercut portion does not occur so as not to hinder the release.

[0053] 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 shape. Convex portions 4B can be continuously connected. Even in such a configuration, since the base 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. There are advantages.

Further, a structure as shown in FIG. 9 may be formed over the entire surface of the force slope 4 in which the row portion 4X is formed only in the central portion. In this case, the flat portion as described above between the row portions 4X. Since such a portion is provided, it is possible to obtain an advantage that a molded product with higher luminance uniformity can be obtained while ensuring sufficient molding efficiency.

[0055] In the present modification, the configuration of the row portion 4X is a configuration in which two linear convex portions 4B are connected, but it may have a shape in which three or more linear concave portions are connected. Further, a configuration in which a plurality of types of row sections are combined may be employed. For example, as shown in FIG. 10, a configuration in which a row portion 4X including two linear convex portions 4B and a row portion 4Y including three linear convex portions 4B are mixed together. It is out.

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 a linear convex portion 4B is formed only on one of the slopes 4 of each linear portion 3. The stamper 203 can be manufactured by using a bite provided with the single crystal diamond tip and a bite 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 4B is formed only on one of the slopes 4 of each linear portion 3. The stamper 204 is made of the single crystal diamond tool! It can be manufactured by performing the same processing as described above using a tool attached with a chip that has been finely processed by the focused ion beam device or the like on only one surface.

[0058] Although only the modification examples of the mold parts are given as the modification examples of the present invention, the light diffusion plate obtained by using the mold parts according to these modification examples may also be the same modification examples. it can. 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.

Example

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.

A stainless steel SUS430 rectangular plate with dimensions 800mm X 500mm and thickness 2mm was coated with nickel-phosphorous electroless plating with a thickness of 100m. Next, sintering with an apex angle of 100 degrees Using a tool with a diamond chip (Sumidia DA-2200, manufactured by Sumitomo Electric Hardmetal Co., Ltd.) on a micromachining machine tool (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.) A line with an isosceles triangle shape with a width of 70 / ζ πι, height of 24.5 / ζ πι, a pitch of 70 m, and an apex angle of 100 degrees along the short side of the plate against the electroless plating surface of phosphorus A plurality of parts were cut to form an uneven structure, and a stamper was obtained.

[0061] With respect to the obtained stamper, Ra (maxl) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the linear portion were determined using an ultradeep microscope. As a result, Ra (maxl) was ^ 1 μm. Since Ra (max2) was 0.15 μm, Ra (max2) / Ra (ma xl) was 0.021. Furthermore, Ra (max2) ZRa (min2) was 7.5 and Sm was.

[0062] Next, the resin constituting the molded product will be described.

Polysiloxane having an alicyclic structure, which is a transparent resin (Nippon ZEON Co., Ltd., ZEONOR 1060R, water absorption 0.01%) 99.7 parts by mass and a polysiloxane having an average particle size of 2 m as a light diffusing agent 0.3 parts by mass of fine particles of a polymer cross-linked product were mixed, kneaded with a twin-screw extruder, extruded into a strand, and cut with a pelletizer to produce a light diffusion plate pellet. Using this light diffusion plate pellet as a raw material, an injection molding machine (clamping force lOOOOkN) was used to mold a 100 mm × 50 mm test plate with a smooth thickness of 2 mm on both sides. The total light transmittance and haze of this test plate were measured using an integrating sphere color difference turbidimeter based on JIS K7361-liJIS K7136. The test plate had a total light transmittance of 85% and a haze of 99%.

[0063] 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 m. Using an injection molding machine having such a mold (clamping force 4,410 kN), the light diffusion plate is produced 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. Was molded. The light diffusing plate thus obtained was strong enough to stick to the stamper even after 100 shots of injection molding.

[0064] The obtained light diffusing plate has a rectangular shape with a thickness of 2mm, 727.5mm x 415mm, to which the concave-convex structure of the stamper is sufficiently transferred, and has a linear pre-shaped cross section on one surface. A prism row consisting of a plurality of prisms arranged substantially in parallel was formed. This linear prism is The apex angle was 100 ° and the pitch was 70 μm. Note that the plurality of uneven portions formed on the flat surface of the uneven structure in the stamper were partially transferred, but were not transferred as much as a whole.

[0065] Next, a reflective sheet (RF 188, manufactured by Gidden Co., Ltd.) is attached to the inner surface of a milky white plastic case with an inner width of 700mm, a depth of 400mm, and a depth of 20mm. 12 mm cold cathode fluorescent lamps with a diameter of 3 mm and a length of 750 mm are arranged so that the distance between the centers of the cold cathode fluorescent lamps is 33 mm, and the vicinity of the electrodes is fixed with a silicone sealant, and an inverter is installed. It was.

[0066] Next, the obtained light diffusion plate was arranged so that the prism row was on the opposite side of the cold-cathode tube (counter-light source position), and was placed on a plastic case with the cold-cathode tube 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. In addition, three diffusion sheets (“188GM3”, manufactured by Kimoto Co., Ltd.) were installed on this light diffusion plate. In this manner, 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.

[0067] Next, a cold cathode tube was turned on by applying a tube current of 5 mA to the obtained direct type backlight, and 100-second equidistant on the center line in the short direction using a two-dimensional color distribution measuring device. The brightness in the front direction of the points was measured, and the brightness average value La and brightness 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 = (Ll + L2) Z2 (Formula 1)

Luminance unevenness Lu = ((Ll- L2) ZLa) X 100 (Equation 2)

L1: Average brightness maxima just above the cold cathode tubes installed

L2: Average of local minimum values between local maximums

Note that the luminance unevenness is an index indicating the uniformity of luminance, and the value increases when the luminance unevenness is bad.

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 along the longitudinal direction. As a result, Ra of the roughened surface was 0.6 m. The resulting light diffusion plate The surface on which the structure is sufficiently transferred and the prism rows are formed has the same shape as in Example 1 (however, the light diffusing plate has a shape in which the concave and convex portions of the linear recesses are reversed). The surface on which no row was formed was roughened as compared with Example 1. The plurality of uneven portions formed on the flat surface of the uneven structure in the stamper was partially transferred but was not transferred as a whole. The obtained light diffusion plate was strong enough to stick to the stamper even after 100 shots of injection molding. Further, in the obtained direct type backlight device, the average luminance was 6,810 cdZm ² and the luminance unevenness was 0.5%.

[0069] <Example 3>

A stainless steel SUS430 rectangular plate with dimensions 800mm X 500mm and thickness 2mm was coated with nickel-phosphorous electroless plating with a thickness of 100m. Next, a bit on which a sintered diamond tip (Sumidia DA-2200, manufactured by Sumitomo Electric Hardmetal Co., Ltd.) with an apex angle of 100 degrees was mounted, and a single crystal diamond tip with an apex angle of 100 degrees (Contool Fine Touring). Using a tool for micromachining (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.) while replacing the tool with a tool attached to the nickel-phosphorous electroless mesh surface, Along the short side direction, a stamper is formed by cutting a plurality of isosceles triangular lines with a width of 70 μm, a height of 24.5 m, a pitch of 70 μm, and an apex angle of 100 degrees to form a concavo-convex structure. Got. 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 cutting tool to which a single crystal diamond tip is attached. The second linear portion and the second linear portion are configured to repeat in this order.

[0070] With respect to the obtained stamper, Ra (maxl) 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 (maxl) was 7.1 μm. Since Ra (max2) was 0.15 μm, Ra (max2) / Ra (maxl) was 0.021. Furthermore, Ra (max2) ZRa (min2) is 7.5, and Sm is 70 μm.

[0071] With such a stamper attached to one mold, the molded surface of the other mold was roughened in the same manner as in Example 2, and the molded product was formed in the same manner as in Example 1 above. A certain light diffusion plate and direct type backlight device were obtained. [0072] 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 of the mold part shown in FIG. FIG. 7 shows a configuration in which the first linear portion and the second linear portion are repeatedly formed, which is different from that of 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 Ra of the roughened surface was 0.6 μm. The plurality of uneven portions formed on the flat surface of the uneven structure in the stamper was partially transferred but was not transferred as a whole. The resulting light diffusing plate stuck to the stamper only once when injection molding was carried out 100 shots, but it did not greatly affect moldability. In the obtained direct type backlight device, the average luminance was 6,878 cd / m ² and the luminance unevenness was 0.3%.

A stainless steel SUS430 rectangular plate with dimensions 800mm X 500mm and thickness 2mm was coated with nickel-phosphorous electroless plating with a thickness of 100m. 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) device (manufactured by Hitachi High-Technologies Corporation). To produce a finely processed chip. This tip was attached to a bite to produce a bite with a micromachined tip.

[0074] Using a bit with such a micromachined chip attached to a machine tool for micromachining (for example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.), the plate material is applied to the nickel-phosphorous electroless mesh surface. Along the short side, a plurality of isosceles triangular sections with a width of 70 μm, a height of 24.5 m, a pitch of 70 μm, and an apex angle of 100 degrees are cut to form a concavo-convex structure. Got a stamper.

[0075] For the obtained stamper, Ra (maxl) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the linear portion were determined using an ultradeep microscope. As a result, Ra (maxl) was 7.1 μm. Since Ra (max2) was 0.1 μm, Ra (max2) / Ra (maxl) was 0.014. Furthermore, Ra (max2) ZRa (min2) was 5.0 and Sm was. In FIG. 8, the length Dl and the D3 force ^ 4.6 m, and the length D2 force ^ 36.5 m. In FIG. 9, the length of the bottom of the linear convex portion 4B was 0.5 m, and the interval between the row portions 4X was 1. O / zm.

[0076] Such a stamper is attached to one mold, and the molded surface of the other mold is roughened in the same manner as in the second embodiment. A certain light diffusion plate and direct type 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. Since the convex portion 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 row was not formed was roughened, and Ra of the roughened surface was 0.6 μm. Note that the plurality of uneven portions formed on the flat surface of the uneven structure in the stamper were partially transferred but were not transferred as a whole. The obtained light diffusion plate was strong enough to stick to the stamper after 100 shots of injection molding. In the obtained direct type backlight device, the average luminance was 6,946 cd / m ² and the luminance unevenness was 0.3%.

A machine tool for microfabrication is performed by appropriately exchanging the noite to which the micromachined chip manufactured in Example 4 is attached and the bite to which the single crystal diamond chip having the apex angle of 100 degrees is attached ( For example, the width of 70 / ζ πι, height 24.5 / ζ πι, and pitch along the short side of the plate against the nickel-phosphorous electroless plating surface A stamper was obtained by forming a concavo-convex structure by cutting a plurality of linear parts having an isosceles cross section of 70 / ζ πι and an apex angle of 100 degrees. Specifically, in the same manner as in Example 3, a plurality of linear portions are divided into a third linear portion formed by a knot to which a micromachined chip is attached, and a bite to which a single crystal diamond tip is attached. The fourth linear portion formed by the above and the fourth linear portion are configured to repeat in this order.

[0079] For the obtained stamper, Ra (maxl) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope of the third linear portion were obtained using an ultra-deep microscope. . As a result, Ra (maxl) was 7.1 μm. Since Ra (max2) was 0.1 μm, Ra max2) / Ra (maxl) was 0.014. Furthermore, Ra (max2) ZRa (min2) is 5.0 and Sm force is 0 m.

[0080] While mounting such a stamper on one mold and using a roughened cavity surface of the other mold in the same manner as in Example 2, a molded product was obtained in the same manner as in Example 1 above. A certain light diffusion plate and direct type 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 of the stamper shown in FIG. 11 is a configuration in which the third linear portion and the fourth linear portion are repeatedly formed, which is different from that of the present example, and because the linear convex portion of the stamper is transferred. In the light diffusion plate, the unevenness is reversed). Further, as in Example 2, the surface on which the prism row was not formed was roughened, and Ra of the roughened surface was 0.6 m. The plurality of uneven portions formed on the flat surface of the uneven structure in the stamper was partially transferred but was not transferred as a whole. The resulting light diffusing plate had a force that caused sticking to the stamper only once after 100 shots of injection molding, which was not a major hindrance to moldability. In the obtained direct type backlight device, the average luminance was 7,016 cdZm ² and the luminance unevenness was 0.2%.

A stainless steel SUS430 rectangular plate with dimensions 800mm X 500mm and thickness 2mm was coated with nickel-phosphorous electroless plating with a thickness of 100m. Next, a focused ion beam (FIB) device (Hitachi High-Technology) is applied only to one of the surfaces of the single crystal diamond tip (manufactured by Contour Nole Fine Tooling) with an apex angle of 100 degrees. The same microfabrication as that of one surface of the micromachined chip of Example 4 was performed using a single company) to produce micromachined chip 2. This chip was attached to a cutting tool to produce a cutting tool with a micro-processed chip 2 attached.

[0083] A tool with a micro-processed chip 2 attached thereto is used as a machine tool for micro-processing.

(For example, Nano Gruber AMG71P, manufactured by Fujikoshi Co., Ltd.), 70m wide, 24.5m high, 70m pitch along the short side of the plate against the nickel-phosphorus electroless plating surface. A stamper was obtained by forming a concavo-convex structure by cutting a plurality of linear parts having an isosceles triangular section with an apex angle of 100 degrees. [0084] For the obtained stamper, Ra (maxl) of the linear portion, Ra (max2), Ra (min2), and Sm of the slope on which the linear convex portion was formed were obtained using an ultra-deep microscope. . As a result, R a (maxl) was 7.1 μm. Since Ra (max2) was 0.1 μm, Ra max2) / Ra (maxl) was 0.014. Furthermore, Ra (max2) ZRa (min2) is 5.0 and Sm is 70 μm.

[0085] While mounting such a stamper on one mold and using a roughened cavity surface of the other mold in the same manner as in Example 2, a molded product was obtained in the same manner as in Example 1 above. A certain light diffusion plate and direct type backlight device were obtained.

[0086] The obtained light diffusion plate had the uneven structure of the stamper sufficiently transferred, and the surface on which the prism array was formed had a shape similar to the shape shown in FIG. Since the convex portion 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 row was not formed was roughened, and Ra of the roughened surface was 0.6 μm. Note that the plurality of uneven portions formed on the flat surface of the uneven structure in the stamper were partially transferred but were not transferred as a whole. The obtained light diffusion plate was strong enough to stick to the stamper after 100 shots of injection molding. In the obtained direct type backlight device, the average luminance was 6,981 cd / m ² and the luminance unevenness was 0.2%.

[0087] <Comparative Example 1>

A light diffusing plate and a direct type knock light 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 (maxl) was 7.1 μm. Since Ra (max2) is 0.003 μm, Ra (max2) / Ra (maxl) is 0.00042. Furthermore, Ra (max2) ZRa (min2) was 6.0 and Sm was 70 m. The obtained light diffusion plate had a shape in which the concavo-convex structure of the mold part was sufficiently transferred. The light diffusing plate obtained using such a mold part was attached to the stamper after 100 shots of injection molding, and was attached to the stamper. In the obtained direct type backlight device, the average luminance was 6,948 cdZm ² and the luminance unevenness was 1.6%.

[0088] <Comparative Example 2> Except that the surface of the single-crystal diamond tip was roughened by grinding stone, Example

A light diffusing plate and a direct backlight device were obtained in the same manner as in 1. As a result, Ra (maxl) was 7.1 μm for the mold parts. Since Ra (max2) was 5.0 μm, Ra (max2) ZRa (maxl) was 0.7. Furthermore, Ra (max2) ZRa (min2) was 7.5 and Sm was 70 m. 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 mold parts was strong enough to stick 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%.

[0089] <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 (maxl) was 7.1 μm. Since Ra (max2) was 3.0 μm, Ra (max2) ZRa (maxl) was 0.42. Furthermore, Ra (max2) ZRa (min2) was 1.2, and Sm was 7 O / zm. 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 mold parts was strong enough to stick to the stamper even after 100 shots of injection molding. In the obtained direct backlight device, the average luminance was 6,600 cd / m ² and the luminance unevenness was 3.6%.

[0090] The results of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1 and Table 2, respectively.

[0091] [Table 1]

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 aCmaxl ^ μιη 7.1 7.1 7.1 7.1 7.1 7.1

Ravmax2) μιη 0.15 0.15 0.15 0.1 0.1 0.1

Ra (max2) 1 ― 0.021 0.021 0.021 0.014 0.014 0.014 Stamper

Ravmaxi

(One mold)

Ra (max2) / 1 7.5 7.5 7.5 5.0 5.0 5.0 Ra (min2)

Sm μπι 70.0 70.0 70.0 70.0 70.0 70.0 The other mold Ra μπι 0.003 0.6 0.6 0.6 0.6 0.6 Pre-shape Cut Cross-section Cross-section Cross section Isosceles Isosceles Isosceles Isosceles Isosceles Light diffuser strip Triangle Triangle Triangle Triangle Triangle Triangle Vertical angle 100 100 100 100 100 100 Pitch μιη 70 70 70 70 70 70 Direct type brightness cd / m ² 6879 6810 6878 6946 7016 6981 Backlight brightness unevenness% 0.4 0.5 0.3 0.3 0.2 0.2 Equipment Formability Sheet 0 0 1 0 1 0] Comparative Example 1 Comparative Example 2 Comparative Example 3

Ra (maxl) μπι 7.1 7.1 7.1

Ra (max2) μιη 0.003 5.0 3.0

Ra (max2) / 0.00042 0.70 0.42

Haku

Ra (m axl)

(One mold)

Ra (max2) / ― 6.0 7.5 1.2

Ra (min2)

Sm μπι 70.0 70.0 70.0

The other mold Ra μιη 0.003 0.003 0.003

Pre-shape ― Cut off Cut [S

Zum Isosic Isosic Isosic

Light diffusing plate Row Triangle Triangle Triangle

Vertical angle 100 100 100

Pitch μπι 70 70 70

Direct type brightness cd / m ² 6948 6470 6600 Backlight brightness unevenness% 1.6 4.8 3.6

Equipment Formability Sheet 100 0 0 [0093] In Table 1, formability is a value indicating how many times a flat molded product has stuck to a stamper when injection molding is performed 100 shots.

[0094] As shown in Table 1, in Examples 1 and 2, it was found that the moldability (releasability) was excellent and the luminance and brightness unevenness were also 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. Also in Examples 3 to 6, it was found that the moldability (releasability) was sufficiently excellent, and both the brightness and the brightness unevenness were good.

[0095] As shown in Comparative Example 1, in the case where the concavo-convex portions were not formed on the surface of each surface of the concavo-convex structure, the moldability was insufficient and the luminance unevenness was generated. In addition, as shown in Comparative Example 2, when uneven portions having dimensions of a predetermined size or more were formed on the surface of each surface of the uneven structure, it was found that the luminance unevenness was increased. Further, as shown in Comparative Example 3, when random (non-anisotropic) uneven portions were formed on the surface of each surface of the uneven structure, it was found that the luminance unevenness was increased.

Claims

The scope of the claims

[1] A mold part for forming a resin-made flat molded product used for an optical component, having a cavity surface for forming the surface of the flat molded product,

The cavity surface has a concavo-convex structure with a maximum center line average roughness Ra (maxl) measured in the direction in which the center line average roughness Ra is maximum on the cavity surface being 3.0 / ζπι to 1,000 m. ,

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 a plane provided with these uneven portions, the maximum center line average roughness Ra (max2) force measured in the direction in which the center line average roughness Ra on the plane is maximum, Ra (maxl), 0.5> R a (max2) / Ra (maxl)> 0.002 The minimum centerline average roughness Ra (min2) measured in the direction satisfying 1 and having the minimum centerline average roughness Ra on the plane And a mold part characterized by satisfying the relation 2 of Ra (max 2) / Ra (min2)> l.5.

[2] In the mold part according to claim 1,

When the Ra (max2) is measured in the same direction as the measurement direction, the average interval Sm between the adjacent concavo-convex portions is between Ra (maxl) and Ra (maxl) X10> Sm> Ra ( maxl) Mold part characterized by satisfying relation 3 of XO .001.

[3] In 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.

[4] In 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 m to 700 m. Mold parts characterized by this.

[5] In 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,

A mold part characterized in that a plane other than the at least two planes is inclined opposite to the at least two planes.

[6] In 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 of the mold part. Equal to the angle between the plane perpendicular to the direction

The angle is between the X point and the Y point between a specific X point and a Y point that is a predetermined distance away from the X point in a direction perpendicular to the longitudinal direction of the linear portion. Die parts that increase in size continuously or stepwise.

[7] The mold part according to claim 1,

The mold unit is characterized in that the structural unit is a convex structure or a concave structure having three or more planes.

[8] The mold part according to claim 7,

The convex or concave structure having three or more planes is a pyramid or a truncated pyramid shape.

[9] In 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 making a V-shaped cut into the linear portion in a direction different from the longitudinal direction of the linear portion. Is mold parts.

[10] The mold part according to claim 7,

The structural unit is a concave structure having three or more planes,

The concave structure is formed 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. form A mold part obtained by transferring the convex shape of a transfer member having a shape.

[11] The mold part according to claim 1,

The uneven part is formed on a plane of a part of a plurality of the structural units.

[12] In 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.

[13] In 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.

[14] A flat molded product for an optical component obtained by injection molding using the mold component according to claim 1,

At least one of the main surfaces has a maximum center line average roughness Ra (Dmaxl) measured in the direction in which the center line average roughness Ra is maximum on the main surface 3. O / zm ~: L, OOO / It has a prism structure that is zm,

Each of the plurality of prism portions constituting the prism structure has two or more surfaces, and the surface of each surface of the prism portions was measured in a direction in which the center line average roughness Ra on the surface is maximized. The maximum center line average roughness Ra (Dmax2) satisfies the relationship 0.5> Ra (Dmax2) / Ra (Dmax2)> 0.002 with the Ra (Dmaxl), and on the surface Roughness surface satisfying the relationship of R a (Dmax2) / Ra (Dmin2)> l.5 with the minimum centerline average roughness Ra (Dmin2) measured in the direction that minimizes the centerline average roughness Ra A flat plate molded product characterized by