WO2012023447A1

WO2012023447A1 - Surface shape transfer resin sheet manufacturing method

Info

Publication number: WO2012023447A1
Application number: PCT/JP2011/067980
Authority: WO
Inventors: 豊博濱松; 麻貴河村
Original assignee: 住友化学株式会社
Priority date: 2010-08-20
Filing date: 2011-08-05
Publication date: 2012-02-23
Also published as: TW201210796A; JP2012061836A

Abstract

Provided is a surface shape transfer resin sheet manufacturing method capable of accurately transferring a transfer pattern to the surface of a resin sheet and, in addition, capable of preventing a winding phenomenon at a shaped roll from occurring. In one embodiment of the invention, a resin sheet (53) is formed by continuously extruding a resin in a heat-melting state from a die (58), and the resin sheet (53) is inserted between an upper roll (63) and an intermediate roll (64). Next, the resin sheet (53) is conveyed while being firmly attached to the intermediate roll (64), and the conveyed resin sheet (53) is inserted between the intermediate roll (64) and a lower roll (65). Upon insertion between the intermediate roll (64) and the lower roll (65), an intaglio transfer pattern (69) formed on the lower roll (65) is transferred to the surface (76) of the resin sheet (53). As the lower roll (65), a shaped roll is used, which is equipped with the intaglio transfer pattern (69) having the surface with a wetting tension of 35 mN/m or less measured conforming to JIS K6768.

Description

Manufacturing method of surface shape transfer resin sheet

The present invention relates to a method for producing a surface shape transfer resin sheet that can be used for applications such as a light diffusion plate and an optical film.

The surface shape transfer resin sheet is a sheet obtained by continuously extruding a melt-kneaded resin from a die to form a resin sheet, and transferring the uneven shape of the transfer mold to the resin sheet.

As a manufacturing method of the surface shape transfer resin sheet, for example, a step of sandwiching a continuous resin sheet continuously extruded from a die between a first pressing roll and a second pressing roll, and a surface of the second pressing roll A manufacturing method is proposed that includes a step of conveying the continuous resin sheet as it is, and a step of sandwiching the conveyed continuous resin sheet between a second pressing roll and a third pressing roll (for example, Patent Documents). 1). In this method, a transfer mold is attached to the third pressing 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 the use of the surface shape transfer resin sheet, use as a light diffusing plate or an optical film incorporated in a backlight device of a liquid crystal display device is becoming widespread. In these applications, if the uneven shape is not accurately transferred when the resin sheet is manufactured (that is, the transfer rate is not high), the optical properties as designed can be imparted to the light diffusion plate and the optical film. Have difficulty. Therefore, in recent years, establishment of a technique for accurately transferring a transfer mold onto a resin sheet is desired.

As such a method, for example, a method of increasing the temperature of the roll on which the transfer mold is mounted can be considered. In this method, the fluidity of the resin sheet can be increased by the heat transmitted from the roll to the resin sheet, and the resin can be introduced into the tip of the groove portion of the transfer mold, so that an improvement in transfer rate can be expected.

However, if the roll temperature is too high, a “winding phenomenon” in which the resin sheet sticks to the roll surface tends to occur. As a result, there is a problem that a “tick mark” is formed on the surface of the resin sheet after the shape transfer. Here, the tack mark is a striped appearance defect attached to the surface of the resin sheet when peeling off from the transfer mold.

An object of the present invention is a surface shape transfer resin sheet that can accurately transfer a transfer mold to the surface of a resin sheet and that can suppress the occurrence of a winding phenomenon in a shape roll (a press roll provided with a transfer mold). It is to provide a manufacturing method.

The manufacturing method of the surface shape transfer resin sheet of the present invention for achieving the above object includes an extrusion process in which a resin is continuously extruded from a die in a heated and melted state to form a continuous resin sheet, and JIS K 6768 By pressing the surface of the transfer mold against the surface of the continuous resin sheet using a shape roll (Shaped roll) having a transfer mold having a surface with a wetting tension of 35 mN / m or less measured according to And a transfer step of transferring the shape of the transfer mold onto the surface of the continuous resin sheet.

In the method for producing a surface shape transfer resin sheet of the present invention, it is preferable to use a shape roll provided with a transfer mold in which an organic polysiloxane treatment is applied to the surface as the shape roll. Moreover, in the manufacturing method of the surface shape transfer resin sheet of this invention, it is suitable to use the shape roll provided with the transfer type by which the said surface was wash | cleaned after the said organic polysiloxane process as said shape roll.

Furthermore, in the method for producing a surface shape transfer resin sheet of the present invention, when the glass transition temperature of the resin is expressed as Tg (° C.) and the thickness of the continuous resin sheet after transfer is expressed as T (mm), the shape The roll surface temperature is Tg−30 (° C.) or more and Tg + 50 (° C.) or less, and the transport speed of the continuous resin sheet is 0.2 / T (m / min) or more and 50 / T (m / min) or less. It is preferable that the transfer step is performed under the condition that the surface temperature of the continuous resin sheet before contacting the shape roll is Tg + 50 (° C.) or more and Tg + 160 (° C.) or less.

According to the method for producing a surface shape transfer resin sheet of the present invention, since the wetting tension of the surface of the transfer mold (the contact surface with the continuous resin sheet) is 35 mN / m or less, even if the temperature of the shape roll increases, Occurrence of the “wrapping phenomenon” in which the resin sheet is stuck to the transfer mold can be suppressed. Therefore, it becomes possible to raise the temperature of a shape roll and to improve the fluidity | liquidity of a resin sheet, and to make resin penetrate into the recessed part of a transfer type | mold favorable. Thereby, the transfer mold can be accurately transferred onto the surface of the resin sheet. As a result, if the resin sheet obtained by this manufacturing method is used as a light diffusing plate or an optical film 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 on which a 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 shown in FIG. FIG. 3 is a schematic perspective view of a light diffusing plate made of a resin sheet according to an embodiment of the present invention. FIG. 4 is a schematic perspective view of an optical film made of a resin sheet according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of a main part of the lamp box showing a mounting state of the light diffusing plate and the optical film. FIG. 6 is a schematic configuration diagram of a manufacturing apparatus used in the method for manufacturing a resin sheet according to one embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of the intaglio transfer mold attached to the lower roll. FIG. 8 is a schematic cross-sectional view showing a first modified example (substantially semicircular shape) of the intaglio transfer mold. FIG. 9 is a schematic cross-sectional view showing a second modified example (substantially prism shape) of the intaglio transfer type. FIG. 10 is a schematic configuration diagram showing a modification of the sheet manufacturing apparatus shown in FIG. FIG. 11 is a diagram showing IR spectra of the transfer mold surfaces of Examples and Comparative Examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Overall configuration of liquid crystal display device>
FIG. 1 is a schematic side view of a liquid crystal display device on which a 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 shown in FIG. The liquid crystal display device 1 (liquid crystal television) is a so-called direct 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, for convenience, the liquid crystal display device 1 is shown in a posture in which the front side (viewing side) of the liquid crystal display device 1 is directed upward in the drawing. 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 formed by the side wall 6 having a square frame shape, and the 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 may be done.

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. Further, the distance D between the back surface 18 of the light diffusing plate 10 (for example, the central portion of the back surface 18) and the center of the linear light source 8 is preferably 10 mm to 20 mm from the viewpoint of reducing the thickness. The ratio of the distance L to the distance D (L / D) is preferably 2.5 to 4.0. The interval L is more preferably 40 mm to 55 mm, and the distance D is more 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 to 10. Preferably there is. In FIGS. 1 and 2, only five linear light sources 8 are shown for easy illustration.

Further, as the linear light source 8, a well-known cylindrical lamp such as a fluorescent tube (cold cathode tube), a halogen lamp, or a tungsten lamp can be used. 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.

The liquid crystal panel 3 includes a liquid crystal cell 11 and a pair of polarizing

plates

12 and 13 sandwiching 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, a known liquid crystal cell such as a TFT liquid crystal cell or an STN liquid crystal cell can be used.

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.

<Configuration of light diffusion plate and optical film>
FIG. 3 is a schematic perspective view of a light diffusing plate made of a resin sheet according to an embodiment of the present invention. FIG. 4 is a schematic perspective view of an optical film made of a resin sheet according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of a main part of the lamp box showing a mounted state of the light diffusing 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 (front surface 16) of the light diffusing plate 10, a plurality of semi-elliptical 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 front surface 16 of the light diffusing plate 10, semi-elliptical ridges 17 and concave grooves 19 between adjacent semi-elliptical ridges 17 are alternately formed.

The semi-elliptical ridge 17 has a substantially semi-elliptical contour in a cut surface (III-III cross section in FIG. 3) orthogonal to the direction in which the semi-elliptical ridge 17 extends. A number of semi-elliptical ridges 17 are arranged in parallel with each other at an equal interval E ₁ (for example, 1 μm to 15 μm). The distance (pitch P ₁ ′) between the centers of the adjacent semi-elliptical ridges 17 is, for example, 30 μm to 500 μm. Further, the height of the semi-elliptical ridge 17 (depth of the concave groove 19) H ₁ ′ is, for example, 10 μm to 500 μm. The aspect ratio represented by the ratio of the 'height _{H 1} for "pitch _{P 1} of the semi-elliptic convex strip _{_{17 (H 1' / P 1}} ') , for example, 0.3 or more, preferably 0.4 to 0.7.

On the other hand, the other main surface (back surface 18) of the light diffusing plate 10 is a flat surface having no irregularities. Further, as shown in FIG. 5, the thickness T ₁ of the light diffusing plate 10 from the back surface 18 to the top of the semi-elliptical ridges 17 on the front surface 16 is, for example, 1 mm to 4 mm.

Further, as shown in FIG. 4, the optical film 4 is formed in a square plate shape substantially the same as the shape of the light diffusion plate 10.

On one main surface (front surface 20) of the optical film 4, a plurality of convex shapes 21 extending between a pair of opposing peripheral edges of the optical film 4 are formed in a streak shape. The cross section of the convex shape 21 (IV-IV cross section in FIG. 4) is, for example, a semi-elliptical shape, a prism shape, or the like (a semi-elliptical shape in FIG. 4). That is, on the front surface 20 of the optical film 4, convex shapes 21 and concave grooves 22 between adjacent convex shapes 21 are alternately formed.

A large number of the convex shapes 21 are arranged at equal intervals E ₂ (for example, 1 μm to 15 μm) in parallel with each other. The distance (pitch P ₂ ′) between the centers of adjacent convex shapes 21 is, for example, 30 μm to 500 μm. Further, the height of the convex shape 21 (depth of the concave groove 22) H ₂ ′ is, for example, 10 μm to 500 μm. The aspect ratio represented by the ratio of 'the height _{H 2} to' pitch _{P 2} of the convex _{_{21 (H 2 '/ P 2}} ') , for example, 0.3 or more, preferably 0.4 to 0 .7.

On the other hand, the other main surface (back surface 23) of the optical film 4 is a flat surface having no irregularities. Further, as shown in FIG. 5, the thickness T ₂ of the optical film 4 from the back surface 23 to the top of the convex shape 21 on the front surface 20 is, for example, 0.1 mm to 1 mm.

The raw material for the light diffusing plate 10 and the optical film 4 is not particularly limited, and a resin such as an amorphous translucent resin or a crystalline resin can be used.

Examples of the amorphous translucent resin used include 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).

Examples of the crystalline resin used include propylene-based resins and ethylene-based resins.

The above amorphous translucent resin and crystalline resin can be used alone or in combination of two or more. Moreover, among these, as a raw material of the light diffusing plate 10, a styrene resin and a polycarbonate are preferable and single use of a styrene resin is more preferable. Moreover, as a raw material of the optical film 4, a polycarbonate, an acrylic resin, MS resin, and AS resin are preferable.

Moreover, the light diffusing plate 10 and the optical film 4 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 resin constituting the light diffusing plate 10 and the optical film 4 and can diffuse transmitted light. Examples of inorganic light diffusing agents include calcium carbonate, 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, siloxane polymer particles, and the like, and preferably a high molecular weight weight having a weight average molecular weight of 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 above light diffusing agents can be used alone or in combination of two or more.

When the light diffusing plate 10 and the optical film 4 contain a light diffusing agent, the mixing ratio of the light diffusing agent is preferably 0.001 to 1 part by weight, more preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the resin. 0.01 parts by weight. The light diffusing agent can be used as a master batch in which the light diffusing agent is dispersed in the resin. The absolute value of the difference between the refractive index of the resin and the refractive index of the light diffusing agent is usually 0.01 to 0.20, preferably 0.02 to 0.15, from the viewpoint of light diffusibility. It is.

Further, if necessary, the light diffusion plate 10 and the optical film 4, for example, an antistatic agent, an ultraviolet absorber, a heat stabilizer, an antioxidant, a weathering agent, a light stabilizer, a fluorescent whitening agent, a processing stabilizer, and the like. These various additives can also be added.

The ultraviolet absorber is not particularly limited, and examples thereof include a salicylic acid phenyl ester ultraviolet absorber, a benzophenone ultraviolet absorber, a triazine ultraviolet absorber, and a benzotriazole ultraviolet absorber. When an ultraviolet absorber is added, it is preferable to add 0.1 to 3 parts by weight of the ultraviolet absorber with respect to 100 parts by weight of the 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 the light-diffusion plate 10 and the optical film 4 can be maintained favorable.

The heat stabilizer is not particularly limited, and examples thereof include manganese compounds and copper compounds. In the case of adding a 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 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.

The antioxidant is not particularly limited, and examples thereof include hindered phenol compounds and hindered amine compounds. When the antioxidant is added, it is preferable to add 0.1 to 3 parts by weight of the antioxidant with respect to 100 parts by weight of the resin.

As shown in FIG. 5, the light diffusing plate 10 has a side wall of the lamp box 7 so that the extending direction of the semi-elliptical ridges 17 is parallel to the extending direction of the linear light source 8 in the lamp box 7. 6 is fixed to the lamp box 7 by bringing the back surface 18 of the light diffusion plate 10 into contact therewith. As a result, the open surface 9 of the lamp box 7 is blocked by the light diffusion plate 10. The optical film 4 is disposed in front of the light diffusing plate 10. As shown in FIG. 5, the optical film 4 is arranged so that the direction in which the semi-elliptical ridges 17 in the light diffusing plate 10 extend and the direction in which the convex shapes 21 in the optical film 4 extend are parallel. In addition, the optical film 4 may be arrange | positioned so that the direction where the semi-elliptical protruding item | line 17 in the light diffusing plate 10 extends and the direction where the convex shape 21 in the optical film 4 extend may become perpendicular | vertical.

<Method for producing light diffusion plate (resin sheet)>
The light diffusion plate 10 and the optical film 4 described above can be produced by cutting a resin sheet produced by the following method. In addition, below, although the case where the light diffusing plate 10 is manufactured is demonstrated, the optical film 4 can also be manufactured according to the following method.

FIG. 6 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. 7 is a schematic cross-sectional view of the intaglio transfer mold attached to the lower roll.

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 molding machine 52 is configured by a known extrusion molding machine 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 in 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, 200 mm to 3000 mm.

The pressing roll group 54 includes three

pressing rolls

63, 64, 65 as a mechanism for forming irregularities on the front and back surfaces 75, 76 of the resin sheet 53 by a transfer mold while molding the resin sheet 53 by pressing. The surface 76 of the resin sheet 53 is a surface that forms the front surface 16 of the light diffusing plate 10, 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 surface 18 of the light diffusing plate 10, and is a surface that is not finally subjected to shape processing (for example, a flat surface that maintains flatness in this embodiment). It is.

The three

pressing rolls

63, 64, 65 are each made of a cylindrical metal roll (for example, made of chromium, copper, nickel, stainless steel, or a resin surface material), and the temperature of the peripheral surface thereof. It is a cooling roll having a function of adjusting (surface temperature). The three

pressing rolls

63, 64, 65 are arranged in the vertical direction so that the axes are parallel to each other as the upper roll 63, the intermediate roll 64, and the lower roll 65 as the shape roll in order from the top to the bottom. ing.

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 mold 69 for forming the semi-elliptical ridges 17 and the concave grooves 19 in the resin sheet 53 is provided. The intaglio transfer mold 69 is, for example, copper-plated on a cylindrical metal roll, the plated metal roll is placed on a lathe, and a diamond plating is used to form a copper plating layer in a desired uneven shape. After engraving or forming a groove by chemical etching or the like, the copper plating layer is manufactured by performing a chrome plating process. The surfaces of the upper roll 63 and the intermediate roll 64 that are not provided with the intaglio transfer mold 69 are also subjected to plating treatment such as chromium plating, copper plating, nickel plating, Ni—P plating, etc., if necessary. It may be.

The intaglio transfer mold 69 is preferably manufactured using a combination of a lathe and a diamond tool in order to form a more precise shape with good reproducibility. The chromium plating thickness applied on the copper plating layer is preferably 5 μm or less, more preferably 2 μm or less.

In this intaglio transfer mold 69, as shown in FIG. 7, a number of semi-elliptical grooves 70 opposite to the semi-elliptical ridges 17 are formed in a streak shape along the circumferential direction of the lower roll 65. That is, the intaglio transfer mold 69 includes a semi-elliptical groove 70 and a ridge 71 between the adjacent semi-elliptical grooves 70 (the ridge 71 is opposite to the groove 19, and the surface of the intaglio transfer mold 69. In this case, the surface of the ridge 71 is alternately arranged along the axial direction of the lower roll 65.

The depth H ₁ of the semi-elliptical concave groove 70 is slightly larger than the height H ₁ ′ of the semi-elliptical ridge 17 and is, for example, 10 μm to 500 μm, preferably 20 μm to 300 μm or less. If the depth H ₁ is excessively large, it becomes difficult to allow the resin to enter the tip of the semi-elliptical concave groove 70.

Further, the distance between the centers of the adjacent semi-elliptical grooves 70 (pitch P ₁ ) is appropriately determined according to the shape of the semi-elliptical ridges 17, and is, for example, 30 μm to 500 μm, preferably 40 μm to 450 μm. . If the pitch P ₁ is less than 30 [mu] m, there is a possibility that the resin solidifies immediately in contact with the lower roll 65, to obtain a result, the resin does not penetrate to the tip of the semi-elliptical groove 70, the imprint profile to target There is a risk that it will not be possible. On the other hand, if the pitch P ₁ is greater than 500 [mu] m, there is a possibility that streaks of pitch or also observed with the naked eye, the interference fringe pattern between the liquid crystal panel 3 and the optical film 4 or appear.

The aspect ratio represented by the ratio of the height H ₁ to the pitch P ₁ of the semi-elliptical concave groove 70 (H ₁ / P ₁ ) is, for example, 0.3 or more, preferably 0.4 to 0.7. It is. The difference between the height H ₁ ′ of the semi-elliptical ridge 17 and the depth H ₁ of the semi-elliptical concave groove 70 is that the intaglio transfer mold 69 is transferred to the resin sheet 53 to form the semi-elliptical ridge 17. This is due to the transfer rate (H ₁ ′ / H ₁ ) (%).

The surface of the intaglio transfer mold 69 having such a shape (contact surface with the resin sheet 53) is subjected to organic polysiloxane treatment. The organic polysiloxane treatment is a treatment in which the organic polysiloxane is brought into contact with the transfer mold surface. By this organic polysiloxane treatment, in this embodiment, fine holes (microcracks) generated when chromium plating is applied to the lower roll 65 can be filled with the organic polysiloxane. The organic polysiloxane treatment is performed, for example, by applying an organic polysiloxane solution to the surface of the intaglio transfer mold 69 and drying it, by polymerizing organic siloxane on the surface of the intaglio transfer mold 69, or by treating the organic polysiloxane with the intaglio transfer mold 69. It can be carried out by a method of chemically reacting with a material (for example, chromium plating) and bonding.

The organic polysiloxane is composed of, for example, a skeleton of a bifunctional siloxane unit, a trifunctional siloxane unit, and a tetrafunctional siloxane unit. Examples of the functional group bonded to the siloxane skeleton include a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 6 carbon atoms. Specifically, for example, alkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, octyl, nonyl, decyl and the like A cycloalkyl group such as a cyclohexyl group; an aryl group such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; an aralkyl group such as a benzyl group, a phenylethyl group, and a phenylpropyl group; a vinyl group, an allyl group, a propenyl group, Alkenyl groups such as isopropenyl group, butenyl group, pentenyl group, hexenyl group, octenyl group; cycloalkenyl group such as cyclohexenyl group; some or all of the hydrogen atoms of the above-described hydrocarbon groups are fluorine, bromine, chlorine, etc. Substituted by halogen atoms, cyano groups, etc. A chloromethyl group, chloropropyl group, bromoethyl group, a halogen-substituted alkyl groups such as trifluoropropyl group, for example, such as cyanoethyl group.

Further, after the treatment with the organic polysiloxane, the surface of the intaglio transfer mold 69 can be washed to remove excess organic polysiloxane remaining on the surface of the intaglio transfer mold 69. Thereby, even if the organic polysiloxane remains and fine irregularities are generated on the surface of the intaglio transfer mold 69, the roughened surface can be leveled. The intaglio transfer mold 69 can be cleaned by, for example, a method of wiping the surface of the intaglio transfer mold 69 after the organic polysiloxane treatment with fibers (for example, cotton, silk, etc.).

When the above-described organic polysiloxane treatment is performed, the wetting tension measured in accordance with JIS K 6768 on the surface of the intaglio transfer mold 69 is set to 35 mN / m or less. The surface tension of the intaglio transfer mold 69 is preferably 5 mN / m to 30 mN / m. When this wetting tension exceeds 35 mN / m, a winding phenomenon is likely to occur. On the other hand, when the wetting tension is less than 5 mN / m, shape transfer tends to be insufficient.

Further, motors (not shown) are connected to the rotation shafts of the

pressing rolls

63, 64, 65, respectively, and the upper roll 63 and the lower roll 65 can rotate counterclockwise in FIG. 64 can rotate clockwise. That is, the pressing rolls 63, 64, 65 are “rotatable counterclockwise”, “rotatable clockwise”, and “rotatable counterclockwise” in order from the top. Thereby, all the

rolls

63, 64, 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, 64, and 65 as appropriate.

The diameter of each

pressing roll

63, 64, 65 is, for example, 100 mm to 500 mm. Further, when a metal roll is used as the pressing rolls 63, 64, 65, the surface thereof may be plated with, for example, chrome plating, copper plating, nickel plating, Ni—P plating or the like.

Further, a heater 72 for heating the surface 76 (surface on the transfer side) of the resin sheet 53 conveyed on the intermediate roll 64 may be installed near the intermediate roll 64. The heater 72 is disposed so as to be separated from the peripheral surface 67 of the intermediate roll 64, and heats the resin sheet 53 being conveyed from the surface 76 side. As the heater 72, for example, a known heater such as an infrared heater can be used. The heater 72 may be an in-line type installed in a line where the resin sheet 53 is conveyed, or may be a handy type that can be held by a worker and irradiated with heat.

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 formed of a cylindrical roll (usually a roll made of resin), and face each other so that the upper end of the lower take-up roll 85 is substantially at the same height as the lower end of the lower roll 65. is set up. 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 temperature in the cylinder 56 is the temperature T (R2B) at the inlet of the intermediate roll 64 on the back surface 75 before the resin sheet 53 contacts the intermediate roll 64 (in this specification, the temperature at the inlet of the intermediate roll 64 on the surface of the resin sheet 53 is “ T (R2B) ”) is preferably adjusted appropriately so as to be in the range of 200 ° C. to 290 ° C. Specifically, the temperature in the cylinder 56 is preferably set to 190 ° C. to 250 ° C.

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 First Conveying Step The resin sheet 53 extruded from the die 58 is first fed into the gap (gap) between the upper roll 63 and the intermediate roll 64 (in this case, melted as necessary) A bank (resin pool) is formed) and the upper roll 63 and the intermediate roll 64 are sandwiched and pressed. Thereafter, the back surface 75 (back surface 18) is brought into close contact with the peripheral surface 67 of the intermediate roll 64 and conveyed. During conveyance, the resin sheet 53 is heated by the heater 72 from the surface 76 side while being cooled by the intermediate roll 64. 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 50 ° C. to 200 ° C.

On the other hand, the output of the heater 72 is the temperature T (R3B) at the lower roll 65 inlet of the surface 76 before the resin sheet 53 contacts the lower roll 65 (in this specification, the temperature at the lower roll 65 inlet of the surface of the resin sheet 53). “T (R3B)” is preferably Tg + 50 ° C. ≦ T (R3B) ≦ Tg + 160 ° C., more preferably Tg + 70 ° C. ≦ T (R3B), where Tg is the glass transition temperature of the raw material resin. It adjusts suitably so that it may become the range of <= Tg + 140 degreeC. Thereby, the resin sheet 53 in a state in which appropriate fluidity is maintained can be plunged between the intermediate roll 64 and the lower roll 65. Therefore, the resin can be satisfactorily introduced to the tip of the semi-elliptical concave groove 70 of the intaglio transfer mold 69. In addition, in this specification, the glass transition temperature Tg of resin means the glass transition temperature Tg of resin before adding an additive as mentioned above.

(3) Second pressing step (transfer step) and second conveying step Thereafter, the conveyed resin sheet 53 enters between the intermediate roll 64 and the lower roll 65 (gap), and the intermediate roll 64 and the lower roll 65 It is inserted and pressed. Then, 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 (front surface 16) of the resin sheet 53 in the sheet flow direction (feeding direction). A large number of parallel stripe-like semi-elliptical ridges 17 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 (in this specification, the surface temperature of the lower roll 65 is referred to as “T (R3)”) is the glass transition temperature of the raw resin. Is preferably Tg−30 ° C. ≦ T (R3) ≦ Tg + 50 ° C., more preferably Tg−20 ° C. ≦ T (R3) ≦ Tg + 40 ° C. For example, when a styrene resin having a glass transition temperature Tg of 102 ° C. is used, the surface temperature T (R3) of the lower roll 65 is adjusted so that the lower limit is 72 ° C. and the upper limit is 152 ° C.

If the surface temperature T (R3) of the lower roll 65 is in the above range, the semi-elliptical concave groove of the intaglio transfer mold 69 is prevented while preventing the “wrapping phenomenon” in which the resin sheet 53 sticks to the intaglio transfer mold 69. The resin can be satisfactorily introduced to the tip of 70.

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 is sent to the take-up roll group 55 in the horizontal direction. Thereafter, the resin sheet 53 is manufactured by being taken up by the pair of take-up rolls 85 and 86. And after the resin sheet 53 is further cooled, the said light diffusing plate 10 can be obtained by cut | disconnecting to a suitable magnitude | size.

In addition, the conveyance speed (speed of the production line) V of the resin sheet 53 is preferably 0.2 / T ₁ (m / m) using the thickness T ₁ (mm) of the resin sheet 53 (light diffusion plate 10). min) ≦ V ≦ 50 / T ₁ (m / min), more preferably 0.3 / T ₁ (m / min) ≦ V ≦ 40 / T ₁ (m / min). Adjusted. If the conveyance speed V is in the above range, the resin sheet 53 can be produced in a relatively short cycle time while preventing the occurrence of the “wrapping phenomenon” in which the resin sheet 53 sticks to the intaglio transfer mold 69, so that productivity is good. .

(4) Effects As described above, according to the present embodiment, the surface of the intaglio transfer mold 69 of the lower roll 65 is treated with organic polysiloxane. Thereby, the fine hole (micro crack) produced when the lower roll 65 is plated with chromium can be filled with the organic polysiloxane. Thereby, the wetting tension of the surface of the intaglio transfer mold 69 of the lower roll 65 is 35 mN / m or less. Therefore, even if the surface temperature T (R3) of the lower roll 65 is increased, it is possible to prevent the “winding phenomenon” in which the resin sheet 53 is stuck to the intaglio transfer mold 69. As a result, the temperature T (R3B) at the inlet of the lower roll 65 of the surface 76 of the resin sheet 53 is Tg + 50 ° C. ≦ T (R3B) ≦ Tg + 160 ° C., and the surface temperature T (R3) of the lower roll 65 is Tg−30 ° C. By setting ≦ T (R3) ≦ Tg + 50 ° C. and the conveyance speed V of the resin sheet 53 being 0.2 / T ₁ (m / min) ≦ V ≦ 50 / T ₁ (m / min), the intaglio transfer mold 69 The resin can be better penetrated to the tip of the semi-elliptical groove 70. Moreover, generation | occurrence | production of the tack mark in the resin sheet 53 obtained can be prevented more effectively.

Therefore, according to the present embodiment, the shape of the intaglio transfer mold 69 optimized by the optical design can be reproduced well as the semi-elliptical ridges 17 of the resin sheet 53. Therefore, the light diffusing plate 10 made of the resin sheet 53 can exhibit excellent optical characteristics. Moreover, if the optical film 4 is manufactured according to said method, the optical film 4 can express the outstanding optical characteristic.

That is, by using the manufacturing method disclosed in this embodiment, a highly difficult prism shape, which is difficult to transfer by the conventional manufacturing method, a high H ₁ ′ / P ₁ ′ ratio (0.5 or more), Even a narrow pitch shape (30 μm or less) can be accurately transferred at a high transfer rate.

Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, on the peripheral surface 68 of the lower roll 65, instead of the intaglio transfer mold 69, an intaglio transfer mold 77 having a semicircular groove 78 having a substantially semicircular cross section (cylindrical lens shape) shown in FIG. It is also possible to provide an intaglio transfer mold 79 having a prism groove 80 having a substantially prism shape (for example, a vertex angle θ of 60 ° to 120 °) shown in FIG.

Further, in the above-described embodiment, the shape roll provided with the intaglio transfer mold 69 is arranged as the lower roll 65, but it may be arranged as the intermediate roll 64 as in the manufacturing apparatus 91 shown in FIG. Good. In this case, the temperature T (R2B) at the entrance of the intermediate roll 64 on the back surface 75 of the resin sheet 53 is preferably in the range of Tg + 50 ° C. ≦ T (R2B) ≦ Tg + 160 ° C., where Tg is the glass transition temperature of the raw material resin. More preferably, the temperature is appropriately adjusted so that Tg + 70 ° C. ≦ T (R 2 B) ≦ Tg + 140 ° C. The temperature T (R2B) at the entrance of the intermediate roll 64 on the back surface 75 of the resin sheet 53 is adjusted so that the heater 72 can heat the back surface 75 (the surface on the transfer side) of the resin sheet 53 extruded from the die 58. It can be performed by installing and adjusting the output of the heater 72 or adjusting the temperature of the cylinder 56.

In the above-described embodiment, the back surface 18 of the light diffusing plate 10 and the back surface 23 of the optical film 4 are flat surfaces without unevenness. For example, the mat has fine unevenness after being embossed or the like. It may be a surface. In that case, what is necessary is just to emboss the back surface 75 of the resin sheet 53 in embodiment shown in FIG. 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 may be provided on the peripheral surface 67 of the intermediate roll 64, and the transfer mold may be transferred. In the embodiment of FIG. 10, the surface 76 of the resin sheet 53 may be embossed. In order to emboss the surface 76 of the resin sheet 53, for example, in the manufacturing apparatus 91 for the resin sheet 53, an embossed transfer mold may be provided on the peripheral surface 68 of the lower roll 65, and the transfer mold may be transferred.

Moreover, although the press roll group 54 was a form which arrange | positions the upper roll 63, the intermediate | middle roll 64, and the lower roll 65 along with the perpendicular direction in the above-mentioned embodiment, for example, three press rolls are horizontal or diagonally arranged. It may be arranged side by side. In addition, if the roll is irrelevant in terms of transfer technology, for example, a roll (touch roll) in contact with the resin sheet 53 that assists the conveyance of the resin sheet 53 and the close contact between the resin sheet 53 and the

pressing rolls

63, 64, 65 is used. It may be provided.

In the above-described embodiment, the case where the surface of the intaglio transfer mold 69 (the contact surface with the resin sheet 53) is treated with an organic polysiloxane has been described. However, if the surface has a wetting tension of 35 mN / m or less. For example, the organic polysiloxane treatment may not be performed.

Further, for example, the light diffusing plate (resin sheet) is not limited to a single layer resin plate like the light diffusing plate 10, for example, from a two-layer resin plate, a three-layer resin plate, four or more layers It may be a multi-layer resin plate. Moreover, although the light diffusing plate 10 is used suitably as a light diffusing plate for backlights, it is not particularly limited to such an application.

Further, the backlight system 2 is preferably used as a surface light source device for a liquid crystal display device, but is not particularly limited to such an application. In addition, various design changes can be made within the scope of matters described in the claims.

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples.

<Example 1>
The apparatus which has the structure similar to the resin sheet manufacturing apparatus shown in FIG. 6 was used. As the upper roll and the intermediate roll, mirror surface cooling rolls having chromium plating on the surface were used. Further, as the lower roll, the surface material is made of chromium, and concave grooves having a concave lens shape (substantially semicircular shape) as shown in FIG. A shape roll subjected to siloxane treatment was used. The pitch P ₁ of the intaglio transfer mold having concave lens-shaped concave grooves was 353 μm, and the depth H ₁ was 223.7 μm.

In the production of the resin sheet, first, a styrene resin (“HRM40” manufactured by Toyo Styrene Co., Ltd., Tg: 102 ° C.) is supplied to an extruder having a screw diameter of 40 mm and melt-kneaded at a cylinder temperature of 210 ° C. to 260 ° C. , Fed to the feed block. Next, the resin in the feed block was continuously extruded into a sheet at a T die temperature of 250 ° C. to 260 ° C. via a T die having a width of 250 mm.

Thereafter, the extruded resin sheet (continuous resin sheet) was sandwiched between an upper roll (mirror cooling roll) and an intermediate roll (mirror cooling roll) and conveyed in a state of being wound around the surface of the intermediate roll. Subsequently, the conveyed resin sheet was sandwiched between an intermediate roll and a lower roll (shape roll), conveyed while being wound around the surface of the lower roll, and the resin sheet peeled from the lower roll was taken up by the take-up roll. Accordingly, concave shape on a surface (upper surface) is transferred, the thickness T ₁ is to obtain a surface profile transfer resin sheet 2 mm. The sheet conveyance speed (line speed) was 0.65 m / min (within a range of 0.2 / T ₁ or more and 50 / T ₁ or less). Further, the surface temperature of the resin sheet before contacting the lower roll (temperature T (R3B) at the lower roll inlet) was adjusted by a heater.

And the temperature T (R3B) in the lower roll inlet of the resin sheet surface and the surface temperature T (R3) of a lower roll were changed, and the presence or absence of the winding phenomenon in the manufacturing process of each condition was confirmed. Moreover, the cross section of the obtained resin sheet was observed with a microscope, and the shape transfer rate was determined by measuring the height H ₁ ′ of the ridges.
Shape transfer rate (%) = (height H ₁ ′ of protrusions of resin sheet / depth H ₁ of concave grooves of lower roll) × 100

Further, the wetting tension of the surface of the intaglio transfer mold of the lower roll was measured by the following method in accordance with JIS K 6768 and found to be 23 mN / m. Specifically, the wetting tension was tested using a “mixture for wetting tension test” (hereinafter, simply referred to as “medicine”) manufactured by Wako Pure Chemical Industries, Ltd. First, the temperature of the intaglio transfer mold (work) was stabilized at around 23 ° C. Next, the surface of the intaglio transfer mold was wiped with a cloth soaked with ethanol. Next, a cotton swab was immersed in the chemical, and one drop of the chemical adhering to the cotton swab was placed on the intaglio transfer mold so as not to flow. The determination was made 3 to 5 seconds after placing the liquid. The determination was made by visually observing the placed liquid to determine whether “(1) the liquid is playing” or “(2) the liquid is wet”. The case where the liquid swelled and the size did not change was determined as (1), and the case where the liquid was flat and gradually spread was determined as (2).

After the judgment, if the result is (1), the process proceeds to a chemical having a smaller numerical value (wetting tension), and if the result is (2), the process proceeds to a chemical having a larger numerical value (wetting tension). This operation was repeated to narrow down the chemicals with wet tension that can reliably wet the surface of the intaglio transfer mold, and the wet tension of the chemicals was used as the measurement result.

<Example 2>
As the lower roll (shape roll), the same process as in Example 1 was used except that the surface of the intaglio transfer mold was wiped with a cotton cloth after the organopolysiloxane treatment of Example 1 and the surface was washed. A resin sheet was prepared according to the methods and conditions described above.

And the temperature T (R3B) in the lower roll inlet of the resin sheet surface and the surface temperature T (R3) of a lower roll were changed, and the presence or absence of the winding phenomenon in the manufacturing process of each condition was confirmed. Moreover, the cross section of the obtained resin sheet was observed with a microscope, and the shape transfer rate was determined by measuring the height H ₁ ′ of the ridges. Further, the wetting tension of the surface of the intaglio transfer mold of the lower roll was measured by the same method as in Example 1 and found to be 23 mN / m.

<Comparative Example 1>
A resin sheet was produced by the same method and conditions as in Example 1 except that a roll not subjected to organic polysiloxane treatment was used as the lower roll (shape roll).

And the temperature T (R3B) in the lower roll inlet of the resin sheet surface and the surface temperature T (R3) of a lower roll were changed, and the presence or absence of the winding phenomenon in the manufacturing process of each condition was confirmed. Moreover, the cross section of the obtained resin sheet was observed with a microscope, and the shape transfer rate was determined by measuring the height H ₁ ′ of the ridges. Further, the wetting tension of the surface of the intaglio transfer mold of the lower roll was measured by the same method as in Example 1, and it was 42 mN / m.

<Example 3>
The apparatus which has the structure similar to the resin sheet manufacturing apparatus shown in FIG. 10 was used. As the upper roll and the lower roll, mirror surface cooling rolls having a surface plated with chromium were used. Further, as the intermediate roll, the surface material is made of chrome, and concave grooves having a concave lens shape (substantially semicircular shape) as shown in FIG. A shape roll subjected to siloxane treatment was used. The pitch P ₁ of the intaglio transfer mold having concave lens-shaped concave grooves was 353 μm, and the depth H ₁ was 223.7 μm.

In the production of the resin sheet, first, a polycarbonate resin (“Caliber 200-30” manufactured by Sumitomo Dow Co., Ltd., glass transition temperature Tg measured in accordance with JIS 7212-1987, Tg: 147 ° C.) is used as an extruder having a screw diameter of 40 mm. The mixture was melt-kneaded at a cylinder temperature of 210 ° C. to 260 ° C. and then supplied to the feed block. Next, the resin in the feed block was continuously extruded into a sheet at a T die temperature of 250 ° C. to 260 ° C. via a T die having a width of 250 mm.

Thereafter, the extruded resin sheet (continuous resin sheet) was sandwiched between an upper roll (mirror cooling roll) and an intermediate roll (shape roll) and conveyed in a state of being wound around the surface of the intermediate roll. Then, the conveyed resin sheet was pinched | interposed with the intermediate roll and the lower roll (mirror surface cooling roll), conveyed in the state wound around the surface of the lower roll, and the resin sheet peeled from the lower roll was taken up with the take-up roll. Accordingly, concave shape on a surface (lower surface) has been transferred, the thickness T ₁ is to obtain a surface profile transfer resin sheet 1.2 mm. The sheet conveyance speed (line speed) was 0.90 m / min (range of 0.2 / T ₁ or more and 50 / T ₁ or less).

And the temperature T (R2B) in the intermediate | middle roll inlet_port | entrance of the resin sheet surface was changed, and the presence or absence of the generation | occurrence | production of the winding phenomenon in the manufacturing process of each condition was confirmed. Moreover, the cross section of the obtained resin sheet was observed with a microscope, and the shape transfer rate was determined by measuring the height H ₁ ′ of the ridges. Further, the wetting tension of the surface of the intaglio transfer mold of the intermediate roll was measured by the same method as in Example 1, and found to be 23 mN / m.

<Comparative example 2>
A resin sheet was produced by the same method and conditions as in Example 3 except that a roll not subjected to organic polysiloxane treatment was used as an intermediate roll (shape roll).

During the production, whether or not the winding phenomenon occurred in the production process was confirmed. Moreover, the cross section of the obtained resin sheet was observed with a microscope, and the shape transfer rate was determined by measuring the height H ₁ ′ of the ridges. Further, the wetting tension of the surface of the intaglio transfer mold of the lower roll was measured by the same method as in Example 1, and it was 42 mN / m.

<Evaluation>
(1) Evaluation of Shape Transfer Rate and Winding Phenomenon Evaluation results of the shape transfer rate of the resin sheets obtained by the production methods of Examples 1 and 2 and Comparative Example 1 and the presence or absence of the winding phenomenon are shown in Table 1 below. Table 2 below shows the results of evaluating the shape transfer rate of the resin sheets obtained by the production methods of Example 3 and Comparative Example 2 and the presence or absence of the winding phenomenon. In addition, evaluation of the presence or absence of the winding phenomenon was determined according to the following criteria.
A: No winding B: A little winding C: Winding (winding is larger than B)

(2) IR (Infrared Spectroscopy) Analysis The infrared absorption spectrum of the transfer mold surface of the lower roll (shape roll) used in Examples 1 and 2 and Comparative Example 1 was measured by the ATR reflection method. The obtained IR spectrum is shown in FIG. As shown in FIG. 11, the transfer mold surface of Example 1 showed a peak at the same wave number as the spectrum of the organopolysiloxane, but the transfer mold surface of Example 2 and Comparative Example 1 had a peak. I couldn't see it. The reason why the peak was not observed in Example 2 is considered to be that the transfer mold surface was wiped with a cotton cloth, and this removed organic polysiloxane that could not fit into the fine holes of the chrome plating. .

(3) TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) Analysis A portion of the transfer mold surface of the lower roll (shape roll) used in Examples 1 and 2 and Comparative Example 1 was subjected to TOF-SIMS apparatus. (Analyzed by Physical Electronics). The measurement conditions were as follows. The measurement results are shown in Table 3 below. Table 3 shows the result of normalizing the intensity of each positive ion mass spectrum so that the total intensity of the positive ion mass spectrum is 1.
Irradiated primary ions: ⁶⁹ Ga ⁺
Measurement area: about 80 × 80 μm ²
· The detected secondary _{_{_{ions: Positive (C 5 H 15 Si}}} 2 O + and _{_{_{_{^{C 7 H 21 Si 4 O 4}}}}} +)
Detection mass range: 0.5 to 2000 a. m. u

As shown in Table 3, compared with Example 2 and Comparative Example 1, the transfer mold surface of Example 1 has positive ions derived from organic polysiloxane (C ₅ H ₁₅ Si ₂ O ⁺ and C ₇ H ₂₁ Si). _A large amount of ₄ O ₄ ⁺ ) was detected. The positive ions detected on the surface of the transfer mold of Example 2 were less because the transfer mold surface was wiped with a cotton cloth, thereby removing the organopolysiloxane that could not fit into the fine holes of the chrome plating. This is probably because

4 ... optical film, 10 ... light diffusion plate, 53 ... resin sheet, 58 ... die, 63 ... upper roll, 64 ... intermediate roll, 65 ... lower roll, 69 ... intaglio transfer mold, 76 ... surface of (resin sheet), 77 ... Intaglio transfer mold, 79 ... Intaglio transfer mold.

Claims

An extrusion process in which the resin is continuously extruded from the die in a heated and melted state to form a continuous resin sheet;
By pressing the surface of the transfer mold against the surface of the continuous resin sheet using a shape roll having a transfer mold having a surface with a wetting tension of 35 mN / m or less measured according to JIS K 6768 A transfer step of transferring the shape of the transfer mold to the surface of the continuous resin sheet;
A method for producing a surface shape transfer resin sheet.
The method for producing a surface shape transfer resin sheet according to claim 1, wherein a shape roll having a transfer mold in which an organic polysiloxane treatment is applied to the surface is used as the shape roll.
The method for producing a surface shape transfer resin sheet according to claim 2, wherein a shape roll provided with a transfer mold whose surface is washed after the treatment with the organic polysiloxane is used as the shape roll.
When the glass transition temperature of the resin is expressed as Tg (° C.) and the thickness of the continuous resin sheet after transfer is expressed as T (mm),
The surface temperature of the shape roll is Tg−30 (° C.) or more and Tg + 50 (° C.) or less, and the conveying speed of the continuous resin sheet is 0.2 / T (m / min) or more and 50 / T (m / min) or less. The transfer step is performed under a condition that the surface temperature of the continuous resin sheet before contacting the shape roll is Tg + 50 (° C.) or more and Tg + 160 (° C.) or less. The manufacturing method of the surface shape transcription | transfer resin sheet of description.