JP2012030591A - Method of manufacturing surface shape-transferred resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a surface shape-transferred resin sheet, capable of satisfactorily reproducing the shape of a transfer mold optimized by optical design as a resin sheet while sufficiently introducing a resin to the tip of a groove portion of the transfer mold.SOLUTION: A resin sheet 53 is produced by extruding the resin from a die 58 in a heated and melted state; the resin sheet 53 is inserted between an upper roll 63 and an intermediate roll 64; the resin sheet 53 is then carried as it is closely pressed against the intermediate roll 64, and the carried resin sheet 53 is inserted between the intermediate roll 64 and a lower roll 65. In this step, an engraved plate transfer mold 69 including a recessed groove 70 having a bottom surface with a curvature radius of 100 μm or less is attached to the lower roll 65. When the resin sheet is inserted between the intermediate roll 64 and the lower roll 65, the transfer of the engraved plate transfer mold 69 to the resin sheet 53 is performed while keeping, relative to Tg of the resin, the surface temperature T(R3) of the lower roll 65 at Tg-10°C≤T(R3).

Description

  The present invention relates to a method for producing a surface shape transfer resin sheet that can be used as a light diffusing plate or a light guide plate used in a liquid crystal display device.

The surface shape transfer resin sheet is, for example, a sheet produced by forming a resin sheet that is heated and in a softened state, and transferring the uneven shape of the transfer mold to the surface of the resin sheet.
Specifically, a step of sandwiching a continuous resin sheet formed by continuously extruding melt-kneaded resin from a die between a first pressing roll and a second pressing roll, and a surface of the second pressing roll There is known a manufacturing method including a step of conveying while being in close contact with the substrate and a step of sandwiching between a second pressing roll and a third pressing roll (see, for example, Patent Document 1). In this method, a transfer mold is attached to the third roll, and when the resin sheet is sandwiched between the second pressing roll and the third pressing roll, the uneven shape is transferred to the surface of the resin sheet.

JP 2009-220555 A

As a use of the surface shape transfer resin sheet, a use as a light diffusion plate or a light guide plate incorporated in a backlight device of a liquid crystal display device is becoming widespread. In that case, it is difficult to impart optical characteristics as designed to the light diffusing plate or the light guide plate if the uneven shape is not accurately transferred when the resin sheet is manufactured.
On the other hand, each pressing roll plays a role as a cooling roll for cooling and solidifying the resin sheet. Particularly, for a roll provided with a transfer mold (transfer mold roll), the resin filled in the transfer mold is formed in the shape. There is a demand for the ability to cool and harden while holding Conventionally, a technique is adopted in which the resin is rapidly cooled and solidified by a transfer type roll.

  However, when the tip of the groove portion of the transfer mold is thin (for example, the radius of curvature of the bottom surface of the groove portion is 100 μm or less), when the resin is rapidly cooled, the resin that starts to solidify rapidly from the contact surface with the transfer mold is It was found that the resin sheet was solidified before entering the tip, and the tip shape of the groove was not accurately transferred to the resin, and the resin sheet was in an unfilled shape at the tip. It was found that it was difficult to reproduce the shape as a resin sheet (light diffusion plate or light guide plate).

  The object of the present invention is to allow the resin to penetrate well to the tip of the groove portion of the transfer mold, and to achieve a surface shape that can reproduce the transfer mold shape optimized by optical design as a resin sheet. It is providing the manufacturing method of a transfer resin sheet.

  The method for producing a surface shape transfer resin sheet of the present invention for achieving the above object includes an extrusion step of continuously extruding a resin from a die in a heated and melted state to produce a continuous resin sheet, A first pressing step sandwiched between a pressing roll and a second pressing roll; after the first pressing step, a first conveying step in which the continuous resin sheet is conveyed in close contact with the second pressing roll; and the conveyed A second pressing step of sandwiching a continuous resin sheet between the second pressing roll and the third pressing roll, the third pressing roll having a transfer mold on the surface thereof, and the transfer mold has a radius of curvature of 100 μm or less. In the second pressing step, the surface temperature T (R3) of the third pressing roll is Tg-10 ° C. when the glass transition temperature of the resin is Tg. ≦ T While maintaining the R3), and the transfer mold having the third pressing roll surface characterized in that it comprises a step of transferring the continuous resin sheet.

Moreover, in the manufacturing method of the surface shape transfer resin sheet of this invention, after the said 2nd press process, the 2nd conveyance process which conveys the said continuous resin sheet closely_contact | adhered to the said 3rd press roll, and the said 2nd conveyance process It is preferable that the method further includes a cooling step of cooling the transfer side surface of the continuous resin sheet peeled from the third pressing roll.
In the method for producing a surface shape transfer resin sheet of the present invention, it is preferable that the resin is an amorphous resin.

In the method for producing a surface shape transfer resin sheet of the present invention, the amorphous resin is mainly composed of a styrene resin, an acrylic resin, an acrylic / styrene copolymer resin, a cyclic olefin resin, or a polycarbonate system. It is preferable to include.
Furthermore, in the method for producing a surface shape transfer resin sheet of the present invention, it is preferable that a cross-sectional shape in a direction orthogonal to the longitudinal direction of the groove portion is a substantially semicircular shape or a substantially semielliptical shape.

  According to the method for producing a surface shape transfer resin sheet of the present invention, when the resin is inserted between the second pressing roll and the third pressing roll, the surface temperature of the third pressing roll is minus 10 ° C. of the Tg of the resin. It is held above. Therefore, the resin in contact with the transfer mold can be gradually solidified from the contact surface with the transfer mold when the second press roll and the third press roll are pressed. Therefore, the resin in contact with the transfer mold enters the tip of the groove portion of the transfer mold while gradually solidifying before being completely solidified, and then completely solidified.

  As a result, even when a transfer mold having a groove portion having a bottom surface with a curvature radius of 100 μm or less is transferred to the resin, the tip shape of the groove portion can be accurately transferred to the surface of the resin sheet. Therefore, the shape of the transfer mold optimized by optical design can be reproduced well as a resin sheet. Therefore, if the resin sheet obtained by this manufacturing method is used as a light diffusing plate or a light guide plate of a liquid crystal display device, excellent optical characteristics can be expressed.

FIG. 1 is a schematic side view of a liquid crystal display device (first form) on which a light diffusion plate (resin sheet) according to an embodiment of the present invention is mounted. FIG. 2 is a schematic perspective view of the liquid crystal display device of FIG. FIG. 3 is a schematic perspective view of the light diffusion plate of FIG. FIG. 4 is an enlarged cross-sectional view of a main part of the lamp box showing a mounted state of the light diffusing plate. FIG. 5 is a schematic side view of a liquid crystal display device (second embodiment) on which a light guide plate (resin sheet) according to an embodiment of the present invention is mounted. FIG. 6 is a schematic plan view of the backlight system of FIG. FIG. 7 is a schematic rear view of the backlight system of FIG. FIG. 8 is a diagram illustrating a modification of the dot pattern of the light guide plate. FIG. 9 is a schematic configuration diagram of a manufacturing apparatus used in the method for manufacturing a resin sheet according to an embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of the intaglio transfer mold attached to the lower roll, where (a) shows an overall view and (b) shows an enlarged view of the main part. FIG. 11 is a view showing a modified example (substantially semicircular shape) of the intaglio transfer mold. 12A and 12B are graphs for explaining the transfer accuracy of Example 1 and Comparative Example 1. FIG. 12A shows a transfer profile, and FIG. 12B shows a shape transfer rate. FIG. 13 is a graph for explaining the transfer accuracy of Example 2 and Comparative Example 2, in which (a) shows the transfer profile and (b) shows the shape transfer rate. FIG. 14 is a graph for explaining the transfer accuracy of Example 3, wherein (a) shows the transfer profile, and (b) shows the shape transfer rate. FIG. 15 is a graph for explaining the transfer accuracy of Example 4, wherein (a) shows a transfer profile, and (b) shows a shape transfer rate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Liquid crystal display device (first form)>
(1) Backlight System FIG. 1 is a schematic side view of a liquid crystal display device (first embodiment) on which a light diffusion plate (resin sheet) according to an embodiment of the present invention is mounted. FIG. 2 is a schematic perspective view of the liquid crystal display device of FIG.

  The liquid crystal display device 1 (liquid crystal television) is a so-called direct-type liquid crystal display device, and includes a backlight system 2, a liquid crystal panel 3 disposed in front of the backlight system 2, a backlight system 2, and a liquid crystal panel 3. And an optical film 4 disposed between the two. In FIG. 1 and FIG. 2, the liquid crystal display device 1 is shown in a posture with its front side facing the upper side of the drawing for the sake of convenience. Further, the scales of the constituent members such as the liquid crystal display device 1, the backlight system 2, and the liquid crystal panel 3 shown in the following drawings are set for convenience of explanation, and the scales of all the constituent members are the same. Not that.

The backlight system 2 has a rectangular plate-shaped rear wall 5 and a rectangular frame-shaped side wall 6 integrally standing upright from the periphery of the rear wall 5, and is made of a thin box-shaped resin whose front side is open. A lamp box 7, a plurality of linear light sources 8 provided in the lamp box 7, and a light diffusion plate 10 that closes an open surface 9 (front surface) of the lamp box 7 are provided.
That is, the box-shaped lamp box 7 has an open surface 9 whose outline is defined by a square-shaped side wall 6, and a linear light source 8 is provided in a space surrounded by the side wall 6 and the rear wall 5. On the inner surface of the rear wall 5 of the lamp box 7, for example, a reflection plate (not shown) for reflecting light incident on the rear wall 5 side from the linear light source 8 toward the open surface 9 side of the box is attached to the whole. It has been.

The linear light source 8 is, for example, a cylindrical lamp having a diameter of 2 mm to 4 mm. The plurality of linear light sources 8 are arranged in parallel with each other at an equal interval in a state where they are spaced apart from the back surface 18 of the light diffusion plate 10.
The distance L between the centers of the adjacent linear light sources 8 is preferably 30 mm to 60 mm from the viewpoint of power saving. Moreover, it is preferable that the distance D of the back surface 18 (for example, center part in the back surface 18) of the light diffusing plate 10 and the center of the linear light source 8 is 10 mm-20 mm from a viewpoint of thickness reduction. Moreover, it is preferable that the ratio (L / D) of the space | interval L with respect to the distance D is 2.5-4.0. In particular, the distance L is preferably 40 mm to 55 mm, and the distance D is preferably 13 mm to 17 mm. The number of the linear light sources 8 is inevitably determined by the size of the lamp box 7 (screen size of the liquid crystal display device 1) and the interval L. For example, in the 32 type liquid crystal display device 1, the number is 6-10. Preferably there is. In FIG. 1 and FIG. 2, only five linear light sources 8 are shown for easy illustration.
Moreover, as the linear light source 8, well-known cylindrical lamps, such as a fluorescent tube (cold cathode tube), a halogen lamp, a tungsten lamp, can be used, for example. Further, as the light source of the backlight system 2, a point light source such as a light emitting diode (LED) can be used instead of the linear light source 8.
(2) Liquid Crystal Panel The liquid crystal panel 3 includes a liquid crystal cell 11 and a pair of polarizing plates 12 and 13 that sandwich the liquid crystal cell 11 from both sides in the thickness direction. Such a liquid crystal panel 3 is disposed on the front surface of the backlight system 2 so that the polarizing plate 12 on the back side and the light diffusion plate 10 face each other.

As the liquid crystal cell 11, for example, a known liquid crystal cell such as a TFT liquid crystal cell or an STN liquid crystal cell can be used.
(3) Optical film The optical film 4 is not particularly limited, and examples thereof include a microlens film, a substantially semicircular lenticular lens film, a diffusion film, a prism film, and a reflective polarization separation film.
(4) Light Diffusing Plate FIG. 3 is a schematic perspective view of the light diffusing plate of FIG. FIG. 4 is an enlarged cross-sectional view of a main part of the lamp box showing a mounted state of the light diffusion plate.

As shown in FIG. 3, the light diffusing plate 10 is formed in a square plate shape that is substantially the same as the frame shape of the side wall 6 of the lamp box 7.
On one main surface (outgoing surface 16) of the light diffusing plate 10, a plurality of ridges 17 extending between a pair of opposed peripheral edges of the light diffusing plate 10 are formed in a streak shape. That is, on the emission surface 16 of the light diffusing plate 10, the ridges 17 and the grooves 19 between the adjacent ridges 17 are alternately formed.

As for the protruding item | line part 17, the cut surface orthogonal to the longitudinal direction has the outline of a substantially semi-elliptical shape. The shape of the ridge portion 17 may be a semi-elliptical shape, a prism shape, or a semi-circular shape. Moreover, the shape which changes continuously in one protruding item | line part 17 (shape unit) is preferable, for example, a semicircle shape or a semi-elliptical shape is more preferable than a prism shape.
A large number of the ridges 17 are arranged at an equal interval E (for example, 1 μm to 15 μm) in parallel with each other. The distance (pitch P ′) between the centers of the adjacent ridges 17 is, for example, 200 μm to 500 μm. Moreover, the height (depth of the ditch | groove 19) H 'of the protruding item | line part 17 is 100 micrometers-500 micrometers, for example. Moreover, the aspect ratio represented by the ratio (H '/ P') of the height H 'to the pitch P' of the ridges 17 is, for example, 0.4 or more, preferably 0.5 to 0.7. is there.

On the other hand, the other main surface (back surface 18) of the light diffusing plate 10 is a flat surface having no irregularities.
Moreover, as shown in FIG. 4, the thickness T of the light diffusing plate 10 from the back surface 18 to the top part of the convex part 17 in the output surface 16 is 1 mm-4 mm, for example.
The raw material of the light diffusing plate 10 is not particularly limited, and for example, an amorphous translucent resin can be used.

  As an amorphous translucent resin to be used, for example, acrylic resin, styrene resin, polycarbonate, cyclic polyolefin, cyclic olefin copolymer, MS resin (methyl methacrylate-styrene copolymer resin), ABS resin ( And acrylonitrile-butadiene-styrene copolymer resin) and AS resin (acrylonitrile-styrene copolymer resin).

The said amorphous translucent resin can be used individually or in combination with 2 or more types. Among these, Preferably, a styrene resin or an acrylic resin is mentioned, More preferably, a single use of a styrene resin or a single use of an acrylic resin is mentioned.
Moreover, the light diffusing plate 10 can contain a light diffusing agent (light diffusing particles) if necessary.

  The light diffusing agent is not particularly limited as long as it has a refractive index different from that of the translucent resin constituting the light diffusing plate 10 and can diffuse transmitted light. For example, as an inorganic light diffusing agent, calcium carbonate, Examples thereof include barium sulfate, titanium oxide, aluminum hydroxide, silica, glass, talc, mica, white carbon, magnesium oxide, and zinc oxide. These may be subjected to a surface treatment with a fatty acid or the like.

Examples of the organic light diffusing agent include styrene polymer particles, acrylic polymer particles, and siloxane polymer particles. Preferably, the weight average molecular weight is 500,000 to 5,000,000. Examples include coalescent particles and crosslinked polymer particles having a gel fraction of 10% by mass or more when dissolved in acetone.
The light diffusing agents can be used alone or in combination of two or more.

  When the light diffusing plate 10 contains a light diffusing agent, the mixing ratio of the light diffusing agent is 0.001 to 1 part by weight, preferably 0.001 to 0.01 with respect to 100 parts by weight of the light-transmitting resin. Parts by weight. Moreover, a light-diffusion agent can be used as a masterbatch with the said translucent resin. Further, the absolute value of the difference between the refractive index of the translucent resin and the refractive index of the light diffusing agent is usually 0.01 to 0.20, preferably 0.02 to 0.02 from the viewpoint of light diffusibility. 0.15.

The light diffusing plate 10 may have various additives such as an antistatic agent, an ultraviolet absorber, a heat stabilizer, an antioxidant, a weathering agent, a light stabilizer, a fluorescent whitening agent, and a processing stabilizer, as necessary. Can also be added.
The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid phenyl ester ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, and benzotriazole ultraviolet absorbers. When adding an ultraviolet absorber, it is preferable to add 0.1-3 weight part of ultraviolet absorbers with respect to 100 weight part of translucent resin. If it is the above-mentioned range, the bleeding to the surface of an ultraviolet absorber can be suppressed and the external appearance of a light diffusing plate can be maintained favorable.

  The heat stabilizer is not particularly limited, and examples thereof include manganese compounds and copper compounds. When adding the heat stabilizer, it is preferably added together with the ultraviolet absorber, and the heat stabilizer is preferably added at a ratio of 2 parts by weight or less with respect to 1 part by weight of the ultraviolet absorber in the translucent resin. More preferably, 0.01 to 1 part by weight of a heat stabilizer is added to 1 part by weight of the ultraviolet absorber in the translucent resin.

Moreover, it does not restrict | limit especially as antioxidant, For example, a hindered phenol compound, a hindered amine compound, etc. are mentioned. When adding antioxidant, it is preferable to add 0.1-3 weight part of antioxidant with respect to 100 weight part of translucent resin.
As shown in FIG. 4, the light diffusing plate 10 has a light diffusing plate with respect to the side wall 6 of the lamp box 7 at a position where the ridges 17 are parallel to the linear light source 8 in the lamp box 7. 10 is fixed to the lamp box 7 by bringing the back surface 18 into contact therewith. As a result, the open surface 9 of the lamp box 7 is blocked by the light diffusion plate 10.
<Liquid crystal display device (second embodiment)>
(1) Backlight System FIG. 5 is a schematic side view of a liquid crystal display device (second embodiment) on which a light guide plate (resin sheet) according to an embodiment of the present invention is mounted. FIG. 6 is a schematic plan view of the backlight system of FIG. FIG. 7 is a schematic rear view of the backlight system of FIG. FIG. 8 is a diagram illustrating a modification of the dot pattern of the light guide plate.

The liquid crystal display device 21 (liquid crystal television) is a so-called edge-type liquid crystal display device, and includes a backlight system 22, a liquid crystal panel 23 disposed in front of the backlight system 22, the backlight system 22, and the liquid crystal panel 23. And an optical film 24 disposed therebetween.
In FIG. 5, the liquid crystal display device 21 is shown in a posture with the front side facing the upper side of the drawing for the sake of convenience. Further, the scales of the constituent members such as the liquid crystal display device 21, the backlight system 22, and the liquid crystal panel 23 shown in the following drawings are set for convenience of explanation, and the scales of all the constituent members are the same. Not that. Further, in the following description, as shown in FIGS. 5 to 8, the arrangement direction of the backlight system 22 and the liquid crystal panel 23 is referred to as a z direction (plate thickness direction), which are two directions orthogonal to the z direction. Two directions orthogonal to each other are referred to as an x direction and a y direction.

The backlight system 22 includes a light guide plate (optical sheet) 25 and a point light source (LED light source) 27 arranged to face the side surface 26 of the light guide plate 25.
The point light source 27 functions as a point light source of the backlight system 22 and faces the side surfaces 26 and 26 extending in the y-axis direction of the light guide plate 25 as shown in FIGS. 6 and 7. Several are arranged. The plurality of point light sources 27 are discretely arranged along the longitudinal direction (y-axis direction) of the side surface 26. The arrangement interval of the point light sources 27 is usually 5 mm to 20 mm. The point light source 27 may be disposed so as to face the four sides of the light guide plate 25, on two sides facing the x-axis direction (see FIGS. 6 and 7) and on two sides facing the y-axis direction. It may be arranged and may be arranged only on one side (see FIG. 8).

Further, the point light source 27 is not limited to the LED light source, and may be other point light sources. Furthermore, instead of the point light source 27, a linear light source (a cold cathode tube or the like) may be disposed.
Further, the point light source 27 may be a white LED, and a plurality of LEDs may be arranged at one place to constitute one light source unit. For example, as one light source unit, LEDs of three colors different in red, green, and blue may be arranged close to each other. And the light source unit which has several LED is discretely arrange | positioned according to the arrangement | positioning direction mentioned above. In such a case, it is preferable that different LEDs are arranged as close as possible.

As the LED light source used as the point light source 27, those having various light emission distributions can be used, but the luminous intensity in the normal direction (z-axis direction) of the LED light source is maximum, and the half-value width of the luminous intensity distribution is What has the light emission distribution which is 40 degree | times or more and 80 or less is suitable. Specific examples of the LED light source type include a Lambertian type, a shell type, and a side emission type.
(2) Liquid Crystal Panel The liquid crystal panel 23 includes a liquid crystal cell 28 and a pair of polarizing plates 29 and 30 that sandwich the liquid crystal cell 28 from both sides in the thickness direction. Such a liquid crystal panel 23 is arranged on the front surface of the backlight system 22 so that the polarizing plate 29 on the back side and the light guide plate 25 face each other.

As the liquid crystal cell 28, for example, a known liquid crystal cell such as a TFT liquid crystal cell or an STN liquid crystal cell can be used.
(3) Optical film The optical film 24 is not particularly limited, and examples thereof include a microlens film, a substantially semicircular lenticular lens film, a diffusion film, a prism film, and a reflective polarization separation film.
(4) Light Guide Plate As shown in FIGS. 6 and 7, the light guide plate 25 has a rectangular shape, and the size of the plan view shape is selected so as to match the target screen size of the liquid crystal panel 23. As for the screen size of the light guide plate 25, for example, the length of two orthogonal sides (L1 × L2) is preferably a large size of usually 250 mm × 440 mm or more, preferably 500 mm × 800 mm or more. The planar view shape of the light guide plate 25 is not limited to a rectangle, but may be a square.

The light guide plate 25 is formed of a translucent resin that transmits light and has a plate shape. The light guide plate 25 may be a sheet or a film. The thickness T of the light guide plate 25 is preferably 1.0 mm or greater and 4.5 mm or less.
The light guide plate 25 includes a pair of main surfaces (31, 32) facing in the z-axis direction (thickness direction), a pair of side surfaces 26, 26 facing in the X-axis direction, and a pair of side surfaces 33 facing in the Y-axis direction. 33 is provided. The main surfaces (31, 32) are formed in a direction intersecting with the side surfaces (26, 33).

One main surface (31) of the pair of main surfaces facing each other in the z-axis direction functions as an emission surface 31 capable of emitting planar light. The emission surface 31 is disposed on the liquid crystal panel 23 side, and the other main surface (back surface 32) is disposed on the side opposite to the liquid crystal panel 23. In addition, a reflection sheet 34 that reflects light in the light guide plate 25 toward the emission surface 31 is provided at a position facing the back surface 32.
Referring to FIG. 6, a plurality of ridges 35 that are convex outward in the z-axis direction are formed on the emission surface 31 of the light guide plate 25. The ridges 35 extend in the x-axis direction (one direction) and are arranged in parallel in the y-axis direction.

  In addition, examples of the shape of the ridge portion 35 include a prism shape, a semicircular shape, and a semi-elliptical shape, and a shape that continuously changes in one ridge portion 35 (shape unit) is preferable. A semicircular shape or a semi-elliptical shape is preferable to a prism shape. In addition, it is preferable that the direction where the protruding line part 35 extends is parallel to the light emission direction from the light source. Further, in the direction in which the ridges 35 are adjacent (y-axis direction), a plane portion may be formed between the adjacent ridges 35, 35.

  The distance (pitch P ′) between the centers of the adjacent ridge portions 35 is, for example, 200 μm to 500 μm, similar to the light diffusion plate 10 described above. Further, the height H ′ of the ridge 35 is, for example, 100 μm to 500 μm. Moreover, the aspect ratio represented by the ratio (H '/ P') of the height H 'to the pitch P' of the ridge 35 is, for example, 0.4 or more, preferably 0.5 to 0.7. is there.

  On the other hand, referring to FIG. 7, the back surface 32 of the light guide plate 25 is subjected to reflection processing (for example, silk printing) for irregularly reflecting light. As a printing method performed as reflection processing, ink jet printing may be performed in addition to silk printing. Or as a method of reflection processing, you may give a dot-shaped unevenness | corrugation by laser irradiation instead of printing. In the light guide plate 25 of the present embodiment, a dot pattern formed by collecting a plurality of dots 36 is printed as reflection processing. In printing dot patterns, ink having diffusing particles that diffuse light is used.

  Further, the gradation of each dot 36 (printing dot) constituting the dot pattern is changed so as to increase as the distance from the point light source 27 side increases. For example, the diameter of the dot 36a in the region near the side that is a region near the point light source 27 is about 516 μm, and the diameter of the dot 36b in the region near the center of the panel that is the farthest region from the point light source 27 is The diameter of the dot 36c in the intermediate region between them is about 729 μm.

  The diameter of each dot 36 is, for example, in a region close to the point light source 27 when the point light source 27 is disposed on only one side of the side surface 26 of the light guide plate 25 as shown in FIG. The diameter of the dot 36a in the area near one side of a panel is about 516 μm, and the diameter of the dot 36b in the area near the opposite side of the panel, which is the area farthest from the point light source 27, is about 904 μm. The diameter of the dot 36c in the intermediate area between them is about 729 μm.

  The light guide plate 25 is made of a translucent resin. The refractive index of the translucent resin is usually 1.49 to 1.59. As the translucent resin used for the light guide plate 25, methacrylic resin is mainly used. As the translucent resin used for the light guide plate 25, other resins may be used, or a styrene resin may be used. As the translucent resin, acrylic resin, styrene resin, carbonate resin, cyclic olefin resin, MS resin (acrylic and styrene copolymer), and the like can be used.

In applying the light guide plate 25 to the liquid crystal display device 21, additives such as a light diffusing agent, an ultraviolet absorber, a heat stabilizer, and a photopolymerization stabilizer may be added to the light guide plate 25.
<Production method of light diffusion plate or light guide plate (resin sheet)>
The light diffusion plate 10 or the light guide plate 25 described above can be produced by cutting a resin sheet produced by the following method.

FIG. 9 is a schematic configuration diagram of a manufacturing apparatus used in the method for manufacturing a resin sheet according to an embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of the intaglio transfer mold attached to the lower roll, where (a) shows an overall view and (b) shows an enlarged view of the main part.
The sheet manufacturing apparatus 51 takes out the resin sheet 53, a sheet molding machine 52 that extrudes the raw material resin into a sheet shape, a set of pressing rolls 54 for molding the extruded resin sheet 53 by pressing. And a pair of take-up roll groups 55.

The sheet forming machine 52 is configured by a known extruder such as a single screw extruder or a twin screw extruder. The sheet molding machine 52 includes a cylinder 56 for heating and melting (softening) the resin material, a hopper 57 for feeding the resin material into the cylinder 56, and a die 58 for extruding the softened resin material in the cylinder 56. Including.
As the die 58, a metal T die used for a normal extrusion molding method or the like is used. The width of the lip (die lip 59) of the die 58 is selected according to the width of the target resin sheet 53, and is, for example, 300 mm to 3000 mm.

The press roll group 54 includes three press rolls 63 to 65 as a mechanism for forming irregularities on the front and back surfaces 75 and 76 of the resin sheet 53 by a transfer mold while molding the resin sheet 53 by pressing.
In addition, the surface 76 of the resin sheet 53 is a surface that forms the emission surfaces 16 and 31 of the light diffusion plate 10 or the light guide plate 25, and is a shape transfer surface that is finally subjected to shape processing. On the other hand, the back surface 75 of the resin sheet 53 is a surface that forms the back surfaces 18 and 32 of the light diffusion plate 10 or the light guide plate 25, and is a surface that is not finally subjected to shape processing (for example, in this embodiment, the flatness is low). Maintained flat surface).

  Each of the three pressing rolls 63 to 65 is a cooling roll having a function of adjusting the temperature (surface temperature) of its peripheral surface, which is made of a cylindrical metal (for example, stainless steel, steel, etc.) roll. The three pressing rolls 63 to 65 have an axis line as an upper roll 63 as a first pressing roll, an intermediate roll 64 as a second pressing roll, and a lower roll 65 as a third pressing roll in order from top to bottom. They are arranged in the vertical direction so as to be parallel to each other.

In this embodiment, the peripheral surface 66 of the upper roll 63 and the peripheral surface 67 of the intermediate roll 64 are, for example, made smooth surfaces (mirror surfaces) by being mirror-finished.
On the peripheral surface 68 of the lower roll 65, an intaglio transfer die 69 for forming the ridges 17 and 35 and the groove 19 in the resin sheet 53 is provided. The intaglio transfer mold 69 is copper plated on a cylindrical metal roll, the plated metal roll is placed on a lathe, and a diamond bite is used to engrave the copper plated layer into a target lens shape. After forming a groove by chemical etching or the like, a copper plating process is performed on copper.

In order to form a more precise shape with good reproducibility, a lathe-diamond bit combination is preferred, and the chromium plating thickness applied on copper is preferably 5 μm or less, more preferably 2 μm or less.
In this intaglio transfer mold 69, as shown in FIG. 10A, a plurality of concave grooves 70 as grooves opposite to the convex strips 17 and 35 are formed in a streak pattern along the circumferential direction of the lower roll 65. Is formed. In other words, the intaglio transfer mold 69 has a protrusion 71 between the indentation groove 70 and the adjacent indentation groove 70 (this protrusion 71 is opposite to the indentation groove 19 and is referred to as the surface of the intaglio transfer mold 69). Is the surface of the ridge 71.) are alternately arranged along the axial direction of the lower roll 65.

The concave groove 70 has a substantially semi-elliptical outline in the cut surface perpendicular to the longitudinal direction (circumferential direction), and the curvature of the bottom surface 73 (the curved surface in the minute section including the deepest portion of the concave groove 70). The radius R is 100 μm or less, preferably 40 μm to 100 μm.
The depth H of the concave groove 70 is slightly larger than the height H ′ of the ridges 17 and 35, and is, for example, 100 μm to 500 μm, preferably 100 μm to 300 μm or less. If the depth H is excessively large, it is difficult to allow the resin to enter the tip of the groove 70.

  Moreover, although the distance (pitch P) between the centers of the adjacent ditch | grooves 70 is suitably determined according to the shape of the protruding item | line parts 17 and 35, for example, 200 micrometers-500 micrometers, Preferably, they are 250 micrometers-450 micrometers, More preferably , 300 μm to 400 μm. When the pitch P is less than 200 μm, the resin may solidify immediately after coming into contact with the lower roll 65, and as a result, the resin does not enter the tip of the concave groove 70 and a target transfer shape cannot be obtained. There is a fear. On the other hand, when the pitch P exceeds 500 μm, pitch streaks are observed with the naked eye on the back surfaces 18 and 32 of the light diffusion plate 10 or the light guide plate 25, and the liquid crystal panels 3 and 23, the optical films 4 and 24, etc. The moire pattern may appear.

Moreover, the aspect ratio represented by the ratio (H / P) of the height H with respect to the pitch P of the ditch | groove 70 is 0.4 or more, for example, Preferably, it is 0.5-0.7.
The difference between the height H ′ of the ridges 17 and 35 and the depth H of the groove 70 is that when the intaglio transfer mold 69 is transferred to the resin sheet 53 and the ridges 17 and 35 are formed. This is due to the transfer rate (H ′ / H) (%).

  Note that motors (not shown) are connected to the rotation shafts of the pressing rolls 63 to 65, respectively, so that the upper roll 63 and the lower roll 65 can rotate counterclockwise, and the intermediate roll 64 rotates clockwise. Is possible. That is, the pressing rolls 63 to 65 are “rotatable counterclockwise”, “rotatable clockwise”, and “rotatable counterclockwise” in order from the top. Thereby, all the rolls 63 to 65 can be rotated synchronously with the resin sheet 53 sandwiched therebetween. Moreover, the conveyance speed of the resin sheet 53 can be adjusted by adjusting the rotational speed of the press rolls 63-65 suitably.

The diameter of each pressing roll 63-65 is 100 mm-500 mm, for example. Moreover, when a metal roll is used as the pressing rolls 63 to 65, the surface thereof may be subjected to plating treatment such as chromium plating, copper plating, nickel plating, Ni-P plating, or the like.
9, between the pressing roll group 54 and the take-up roll group 55, the surface 76 of the resin sheet 53 immediately after peeling from the lower roll 65 (the shape transfer surface onto which the intaglio transfer mold 69 is transferred). ) Is installed.

  The blower 72 is disposed so as to face the resin sheet 53 being conveyed. Thus, the surface 76 of the resin sheet 53 is cooled by the blower 72 before being taken up by the take-up roll group 55 after being cooled by the lower roll 65 when being transported in close contact with the lower roll 65. Can do. In addition, as the air blower 72, a well-known thing, such as an electric fan and an air knife, can be used, for example.

The pair of take-up roll groups 55 includes a pair of take-up rolls 85 and 86 that sandwich the resin sheet 53 from both sides in the thickness direction.
The take-up rolls 85 and 86 are each made of a cylindrical metal roll (for example, made of stainless steel or steel), so that the upper end of the lower take-up roll 85 is at the same height as the lower end of the lower roll 65. It is installed opposite. Thereby, since the resin sheet 53 delivered from the lower roll 65 can be horizontally conveyed while being supported at the height immediately after the delivery, the conveyance resistance can be reduced.

Next, a method for manufacturing the resin sheet 53 using the above-described manufacturing apparatus will be described.
(1) Extrusion Step First, the raw material resin is charged into the hopper 57 of the sheet forming machine 52, melted and kneaded by the cylinder 56, and then supplied to a feed block (not shown). The cylinder 56 temperature is set to 190 ° C. to 250 ° C., for example.

Next, the resin in the feed block (not shown) is continuously extruded as the resin sheet 53 by being extruded from the die 58.
(2) First Pressing Step and Conveying Step The resin sheet 53 pushed out from the die 58 is first fed into the gap (gap) between the upper roll 63 and the intermediate roll 64 (at this time, the melt bank is formed as necessary) Formed between the upper roll 63 and the intermediate roll 64 and pressed. Thereafter, the back surface 75 (the back surfaces 18 and 32) is brought into close contact with the peripheral surface 67 of the intermediate roll 64, and cooled at that time. The surface temperature of the upper roll 63 and the intermediate roll 64 is preferably lower than the extrusion temperature of the resin sheet 53. For example, the surface temperature of the upper roll 63 is 40 ° C to 160 ° C, and the surface temperature of the intermediate roll 64 is 40 ° C to 170 ° C.
(3) Second Pressing Step Subsequently, the conveyed resin sheet 53 enters (gap) between the intermediate roll 64 and the lower roll 65 and is sandwiched and pressed between the intermediate roll 64 and the lower roll 65. When the intermediate roll 64 and the lower roll 65 are pressed, the surface shape of the intaglio transfer mold 69 is transferred to the surface 76 (the exit surfaces 16 and 31) of the resin sheet 53, so that the sheet flow direction (send-out) A plurality of strip-like ridges 17 and 35 parallel to (direction) are formed.

  Thereafter, the resin sheet 53 is conveyed with the surface 76 in close contact with the peripheral surface 68 of the lower roll 65. When the resin sheet 53 is pressed and conveyed, the surface temperature T (R3) of the lower roll 65 is adjusted to a range of Tg−10 ° C. ≦ T (R3) <Tg + 5 ° C. when the glass transition temperature of the raw material resin is Tg. The For example, when a polystyrene resin having a glass transition temperature Tg of 105 ° C. is used, the lower limit of the surface temperature T (R3) of the lower roll 65 is adjusted to 95 ° C., and the upper limit is adjusted to 110 ° C.

If the surface temperature T (R3) of the lower roll 65 is T (R3) <Tg + 5 ° C., line troubles such as winding of the resin sheet 53 around the lower roll 65, or the resin sheet 53 peels from the lower roll 65. It is possible to satisfactorily prevent the occurrence of peeling marks.
After the conveyance, the resin sheet 53 is peeled off from the lower roll 65 at the lower end of the lower roll 65 and sent out to the take-up roll group 55 in the horizontal direction. After the delivery, the resin sheet 53 is cooled from the surface (shape transfer surface) 76 side by the blower 72. At the time of air cooling by the blower 72, for example, it is preferable that the maximum temperature reached by the surface 76 of the resin sheet 53 (the outlet temperature of the lower roll 65) T (S) is suppressed to T (S) <Tg + 5 ° C. Thereby, thermoelastic deformation can be suppressed satisfactorily.
On the other hand, it is preferable that the minimum temperature reached is Tg minus 10 ° C. or more of the resin. Thereby, the curvature of the resin sheet 53 can be suppressed. The highest and lowest reached temperatures can be measured, for example, by providing a temperature sensor (not shown) on the downstream side of the blower 72.

Thereafter, the resin sheet 53 is manufactured by being taken up by the pair of take-up rolls 85 and 86. Then, after the resin sheet 53 is further cooled, the light diffusion plate 10 or the light guide plate 25 can be obtained by cutting the resin sheet 53 with an appropriate size.
In addition, the conveyance speed of the resin sheet 53 is adjusted so that it may become 2.5 m / min or more, for example. If the transport speed is less than 2.5 m / min, the pressing speed by the intermediate roll 64 and the lower roll 65 may be slow. As a result, the pressing force on the resin sheet 53 is reduced, and there is a possibility that transfer cannot be performed satisfactorily.
(4) Operational Effects As described above, according to the present embodiment, when the resin sheet 53 is inserted between the intermediate roll 64 and the lower roll 65 (gap) and is further brought into close contact with the lower roll 65 and conveyed. The surface temperature T (R3) of the lower roll 65 is maintained at Tg−10 ° C. ≦ T (R3). Therefore, when pressed by the intermediate roll 64 and the lower roll 65, the resin in contact with the intaglio transfer mold 69 can be gradually solidified without quenching from the contact surface with the intaglio transfer mold 69. Accordingly, the resin in contact with the intaglio transfer mold 69 enters the deepest portion (tip) of the concave groove 70 while gradually solidifying before being completely solidified, and then completely solidified.

  As a result, the surface 76 (shape transfer surface) of the resin sheet 53 is transferred even when the intaglio transfer mold 69 having the concave groove 70 having the bottom surface 73 with the curvature radius R of 100 μm or less is transferred to the resin as in this embodiment. ) Can be made substantially the same shape as the contour of the groove 70. Therefore, the shape of the intaglio transfer mold 69 optimized by optical design can be reproduced well as the ridges 17 and 35 of the resin sheet 53. Therefore, the light diffusing plate 10 or the light guide plate 25 made of the resin sheet 53 can exhibit excellent optical characteristics.

That is, by using the manufacturing method disclosed in this embodiment, a prism shape having a high degree of difficulty, which has been difficult to transfer by a conventional manufacturing method, a high H / P ratio (0.5 or more), a narrow pitch shape ( The transfer rate can be improved with high accuracy even for 300 μm or less.
On the other hand, as a typical problem in the production of the surface shape transfer resin sheet, if the resin sheet immediately after peeling from the transfer mold roll is not completely cooled to Tg or less, the thermoelastic deformation (Tg or less) of the resin However, the shape transfer rate to the resin sheet (in this embodiment, the height of the ridges 17 and 35 (depth of the groove 19) H ′ / The depth H × 100 (%) of the concave groove 70 may decrease.

  However, according to this embodiment, the surface 76 (shape transfer surface) of the resin sheet 53 immediately after being peeled from the lower roll 65 is air-cooled by the blower 72, so that the temperature of the surface 76 of the resin sheet 53 is around Tg of the resin. Therefore, the thermoelastic deformation of the resin sheet 53 can be suppressed. Moreover, since such cooling is air cooling, the curvature of the resin sheet 53 at the time of cooling can also be suppressed.

  Furthermore, even if the thermoelastic deformation occurs to some extent after the air cooling of the resin sheet 53 or without air cooling, the individual elastic strips 17 of the resin sheet 53 (the light diffusion plate 10 or the light guide plate 25), All from the center part of 35 to both ends shrinks at a uniform rate. Therefore, the shape of the intaglio transfer mold 69 optimized by the optical design can be maintained even if the ridges 17 and 35 formed in substantially the same shape as the contour of the concave groove 70 contract.

As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented in other embodiment.
For example, if the radius of curvature of the bottom surface of the groove portion of the transfer mold is 100 μm or less, a substantially semicircular shape (cylindrical lens shape) shown in FIG. 11 is used instead of the intaglio transfer mold 69 having the substantially semi-elliptical groove 70. An intaglio transfer mold 77 having a semicircular concave groove 78 can also be used.

  In the above-described embodiment, the back surfaces 18 and 32 of the light diffusing plate 10 or the light guide plate 25 are flat surfaces without unevenness. For example, the mat surface has fine unevenness after being embossed or the like. It may be. In that case, the back surface 75 of the resin sheet 53 may be embossed. In order to emboss the back surface 75 of the resin sheet 53, for example, in the manufacturing apparatus 51 for the resin sheet 53, an embossed transfer mold is wound around the peripheral surface 67 of the intermediate roll 64, and the transfer mold is transferred. .

Further, in the above-described embodiment, the press roll group 54 is configured such that the upper roll 63, the intermediate roll 64, and the lower roll 65 are arranged side by side in the vertical direction. The form arrange | positioned along with a direction may be sufficient.
Further, for example, a roll (touch roll) in contact with the resin sheet 53 and the intaglio transfer mold 69 is provided as long as the roll is irrelevant in terms of transfer technology for assisting conveyance or adhesion between the resin sheet 53 and the pressing rolls 63 to 65. May be.

Further, for example, the light diffusing plate or the light guide plate (resin sheet) is not limited to a single layer resin plate such as the light diffusing plate 10 or the light guide plate 25. For example, a two-layer resin plate or a three-layer resin plate It may be a multi-layer resin plate composed of four or more layers.
The light diffusing plate 10 is suitably used as a light diffusing plate for backlight and the light guide plate 25 is suitably used as a light guiding plate for backlight. However, the light diffusing plate 10 is not particularly limited to such applications.

The backlight systems 2 and 22 are preferably used as a surface light source device for a liquid crystal display device, but are not particularly limited to such applications.
In addition, various design changes can be made within the scope of matters described in the claims.

Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example.
<Raw material of resin sheet>
The following materials (1) and (2) were prepared as raw materials for the resin sheet.
(1) Amorphous resin A: Styrene resin (“HRM40” manufactured by Toyo Styrene Co., Ltd., Tg 105 ° C.)
(2) Amorphous resin B: Acrylic resin (“EXN” manufactured by Sumitomo Chemical Co., Ltd., Tg 102 ° C.)
<Configuration of resin sheet manufacturing apparatus>
The apparatus which has the structure similar to the resin sheet manufacturing apparatus shown in FIG. 9 was used.

In addition, the mirror surface cooling roll by which chromium plating was given to the surface was prepared as a press roll.
Moreover, the transfer mold shown in Table 1 was prepared as a transfer mold to be attached to the pressing roll. In each transfer mold, a semi-elliptical groove is formed in parallel at equal intervals along the circumferential direction of the pressing roll. In Table 1, “pitch P”, “depth H”, “aspect ratio”, and “curvature radius” are values defined in the above-described embodiments.

<Examples and Comparative Examples>
(1) Examples 1-4 and Comparative Examples 1-2
First, the amorphous resin A was supplied to an extruder having a screw diameter of 120 mm, melt-kneaded at a cylinder temperature of 210 ° C. to 250 ° C., and then supplied to a feed block.
Next, the resin in the feed block was extruded in a sheet form at a T die temperature of 260 ° C. to 280 ° C. through a T die having a width of 1500 mm.

  After that, the extruded resin sheet is sandwiched between an upper roll (mirror cooling roll) and an intermediate roll (mirror cooling roll) and conveyed while being wound around the surface of the intermediate roll, and an intermediate roll and a lower roll (transfer type mounting roll) And the resin sheet peeled off from the lower roll was taken up by the take-up roll. Thus, a surface shape transfer resin sheet having a concave shape transferred to the surface (upper surface) was obtained. The conditions in each example and each comparative example are as shown in Table 2.

And the transfer precision of the obtained resin sheet was confirmed by the procedure shown next.
First, as shown in FIGS. 12A to 15A, the contours (profiles) of replica semi-elliptical ridges were graphed on the XY plane. In the XY plane, the X axis is the width direction of the semi-elliptical ridge, and the Y axis is the height direction of the semi-elliptical ridge. Then, as the reference value, the coordinates of the top part are set as (X, Y) = (0, 1), and the coordinates of both end parts thereof are (X, Y) = (− 100, 0) and (X, Y), respectively. ) = (100, 0). The replica refers to a resin sheet on which each transfer mold is transferred at a transfer rate of 100%.

Subsequently, the outline of the semi-elliptical ridge of each resin sheet actually obtained was graphed on the same XY plane as that of the replica by the same method as the graphing of the replica.
Next, a plurality of X coordinates are picked up, and the actual height of the semi-elliptical ridge profile (Y coordinate) at each X coordinate is quantified as a relative value of the replica profile height (Y coordinate). As shown in FIGS. 12B to 15B, the shape transfer rate (%) at a plurality of points in the actual profile was obtained.

  Example 1 and Comparative Example 1 are compared with reference to FIGS. In Example 1, the shape transfer rate is almost constant (about 92%) from the center part (X = 0) of the semi-elliptical ridge to the vicinity of both end parts (X = −80, +80). It was confirmed that the product contracted at a uniform rate with respect to (design shape). On the other hand, in Comparative Example 1, the shape transfer rate at the central portion (tip portion) of the semi-elliptical ridge is about 88%, which is the lowest compared to the shape transfer rate of other portions, and the tip portion of the transfer type groove portion. It was confirmed that the resin was not filled up to.

  Next, referring to FIGS. 13A and 13B, Example 2 and Comparative Example 2 are compared. In Comparative Example 2, the shape transfer rate at the central portion (tip portion) of the semi-elliptical ridge is about 98%, which is the lowest compared to the shape transfer rate of other portions. That is, in Comparative Example 2, it was confirmed that the resin was not filled up to the tip of the groove portion of the transfer mold. On the other hand, in Example 2, the shape transfer rate as a whole is inferior to that of Comparative Example 2, but the shape extends from the central part (X = 0) of the semi-elliptical ridge to the vicinity of both end parts (X = −70, +70). The transfer rate was almost constant (about 95%), and it was confirmed that this contracted at a uniform rate with respect to the replica (designed shape).

Moreover, Example 3 and Example 4 are evaluated with reference to FIG. 14 (a) (b) and FIG. 15 (a) (b). In both Example 3 and Example 4, the shape transfer rate from the central part (X = 0) of the semi-elliptical ridge to the vicinity of both end parts (X = −70, +70), as in Examples 1-2. Was substantially constant, and it was confirmed that this contracted at a uniform rate with respect to the replica (design shape). Particularly in Example 4, since the shape transfer surface of the sheet immediately after peeling from the lower roll was air-cooled, an excellent shape transfer rate (about 98%) was achieved at all points from the center to the vicinity of both ends. I was able to.
(2) Example 5
Amorphous resin B is supplied to an extruder having a screw diameter of 120 mm, melt-kneaded at a cylinder temperature of 210 ° C. to 250 ° C., and then supplied to a feed block.

Next, the resin in the feed block is extruded into a sheet shape at a T die temperature of 260 ° C. to 280 ° C. via a T die having a width of 1500 mm. The discharge amount from the T die is 700 kg / hr.
After that, the extruded resin sheet is sandwiched between an upper roll (mirror cooling roll) and an intermediate roll (mirror cooling roll) and conveyed while being wound around the surface of the intermediate roll, and an intermediate roll and a lower roll (transfer type mounting roll) ) And is conveyed while being wound around the surface of the lower roll, and the resin sheet peeled off from the lower roll is taken up by the take-up roll. Thereby, a surface shape transfer resin sheet having a concave shape transferred to the surface (upper surface) is obtained. The upper roll temperature is 85 ° C, the intermediate roll temperature is 90 ° C, and the lower roll temperature is 98 ° C.

  The surface shape transfer resin sheet thus obtained has a substantially constant shape transfer rate from the center of the semi-elliptical ridge to the vicinity of both ends.

53 Resin sheet 58 Die 63 Upper roll 64 Intermediate roll 65 Lower roll 68 (Lower roll) peripheral surface 69 Intaglio transfer type 70 Indentation groove 77 Intaglio transfer type 78 Semicircular indentation groove

Claims (5)

An extrusion process in which a resin is continuously extruded from a die in a heated and melted state to produce a continuous resin sheet;
A first pressing step of sandwiching the continuous resin sheet between a first pressing roll and a second pressing roll;
After the first pressing step, a first transporting step of transporting the continuous resin sheet while being in close contact with the second pressing roll;
Including a second pressing step of sandwiching the conveyed continuous resin sheet between the second pressing roll and a third pressing roll,
The third pressing roll has a transfer mold on the surface thereof, and the transfer mold has a plurality of grooves having a bottom surface with a radius of curvature of 100 μm or less,
In the second pressing step, the surface temperature T (R3) of the third pressing roll is maintained at Tg−10 ° C. ≦ T (R3), where Tg is the glass transition temperature of the resin. A method for producing a surface shape transfer resin sheet, comprising a step of transferring the transfer mold provided on the surface of the pressing roll to the continuous resin sheet. After the second pressing step, a second transporting step of transporting the continuous resin sheet while being in close contact with the third pressing roll;
The manufacturing method of the surface shape transcription | transfer resin sheet of Claim 1 which further includes the cooling process of cooling the transfer side surface in the said continuous resin sheet peeled from the said 3rd press roll after the said 2nd conveyance process.   The method for producing a surface shape transfer resin sheet according to claim 1 or 2, wherein the resin is an amorphous resin.   4. The surface shape transfer resin sheet according to claim 3, wherein the amorphous resin contains a styrene resin, an acrylic resin, an acrylic / styrene copolymer resin, a cyclic olefin resin, or a polycarbonate resin as a main component. Method.   The manufacturing method of the surface shape transfer resin sheet in any one of Claims 1-4 whose cross-sectional shape in the direction orthogonal to the longitudinal direction of the said groove part is a substantially semicircle shape or a substantially semi-elliptical shape.

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