JP5378867B2 - Manufacturing method and manufacturing apparatus for thermoplastic resin embossed sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture an embossed sheet made of thermoplastic resin, having a high transfer rate, by a simple configuration. <P>SOLUTION: A melted thermoplastic resin sheet 11 is introduced between a third roll 16 having an embossed pattern on its circumferential surface and a metal endless belt 15. The thermoplastic resin sheet 11 is cooled from its one surface side by the first temperature control means 30A of the metal endless belt 15, and then the embossed pattern is transferred to the thermoplastic resin sheet 11 by linear pressure applied between the third roll 16 and the a forth roll 19. Then, the transferred thermoplastic resin sheet 11 is peeled from the metal endless belt 15 and the third roll 16 by the second temperature control means 30B of the metal endless belt 15, and distortion is corrected by a distortion correction roll 17 to obtain the embossed sheet 21 made of thermoplastic resin. Even when the thermoplastic resin sheet 11 to which the embossed pattern is transferred is relatively thick, an embossed pattern is efficiently formed without generating any appearance failures such as a bank defect. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method and an apparatus for producing a thermoplastic resin embossed sheet in which an embossed pattern is provided on the surface of a thermoplastic resin sheet.

Conventionally, a light diffusing sheet containing inorganic fine particles or organic polymer fine particles is known.
By the way, an image display apparatus is required to have high resolution image quality. In the light diffusion sheet used in such an image display device, since the light diffusion state affects the image quality, the light having a pattern that exhibits a prism effect with a fine structure as compared with a configuration using conventional fine particles. A diffusion sheet is desired.
Various configurations are known as a sheet having such a pattern (see Patent Documents 1 to 5).

In the device described in Patent Document 1, a pair of endless belts each formed by connecting a plurality of stainless steel plates are arranged with their outer peripheral surfaces facing each other. On the outer peripheral surface of one of the endless belts, a configuration is adopted in which a reverse shape of a fine hook-like pattern is provided and the film is transferred between the pair of endless belts to transfer the hook-like pattern.
However, in the configuration described in Patent Document 1, since it is press-formed between a pair of endless belts having a reverse mold on the surface and connected with a stainless steel plate, the equipment is large and requires a relatively wide installation space. In addition, there is a demand for improvement in durability of the endless belt.

The one disclosed in Patent Document 2 is a single belt type direct film forming method, in which a metal roll stretched between a third roll having an embossed pattern on the outer peripheral surface and a first roll having an outer peripheral surface coated with an elastic material. A configuration is adopted in which the thermoplastic resin sheet is conveyed while elastically deforming the elastic material of the first roll between the endless belt and the embossed pattern of the third roll is transferred.
However, in the configuration described in Patent Document 2, if the thermoplastic resin sheet becomes thick to some extent, a bank failure may occur. If the surface pressure at the time of transfer is reduced so that the bank failure does not occur, transfer is not possible. There is a possibility that the production will be sufficient, and it is desired that a certain thickness can be manufactured with a high yield.

Patent Document 3 discloses a method in which an emboss pattern is transferred by pressing a molten thermoplastic resin between a fixed roll having an uneven shape for embossing on the surface and a metal belt, and having a thickness of 50 The structure which shape | molds an embossed sheet of -130 micrometers is taken.
However, in the configuration described in Patent Document 3, a relatively thin sheet is formed, and a configuration capable of forming even an embossed sheet having a certain thickness is desired.

The one described in Patent Document 4 conveys a melted film-like resin between an embossing roll and an endless metal belt to apply a surface pressure, and reduces linear pressure by applying pressure between the embossing roll and a take-up roll. Multiply. In this way, a configuration is adopted in which the resin is cooled and the embossed shape is transferred.
However, in the configuration described in Patent Document 4, if the linear pressure is increased in order to obtain a high transfer rate, a bank failure may occur, and a configuration in which a relatively thick sheet is manufactured well is desired.

The one described in Patent Document 5 is between an engraving roll having an imprint for transfer on the outer peripheral surface and an endless belt-shaped crimping drum that rotates in contact with an arc on a part of the outer peripheral surface of the engraving roll. A structure is adopted in which the original sheet is conveyed while being pressed and the imprint is imprinted.
However, the device described in Patent Document 5 has a configuration in which transfer is performed off-line, and improvement in manufacturing efficiency is desired.

JP-A-56-157310 JP 9-295346 A JP 2007-245700 A JP-A-9-164592 Japanese Patent Laid-Open No. 9-141739

As described above, in the configuration in which the pattern is transferred to the conventional resin sheet, a configuration capable of obtaining a high transfer rate with a simple configuration even with a relatively thick sheet is desired.
An object of this invention is to provide the manufacturing method and manufacturing apparatus of the embossing sheet | seat made from a thermoplastic resin which can obtain a high transfer rate efficiently in view of such a point.

  The method for producing an embossed sheet made of a thermoplastic resin according to the present invention includes a first roll and a second roll in which a metal belt is stretched on a peripheral surface, and an emboss pattern is formed on the peripheral surface. A third roll disposed opposite to the circumferential surface of the first roll via the belt; a fourth roll having a circumferential surface opposed to the circumferential surface of the third roll via the belt; A molten thermoplastic resin sheet is produced using a manufacturing apparatus comprising linear pressure control means for controlling the linear pressure applied between the roll and the fourth roll, and belt temperature control means for controlling the surface temperature of the belt. Then, after passing between the first roll and the third roll, passing between the third roll and the fourth roll, an emboss pattern is transferred to the thermoplastic resin sheet, and an embossed sheet made of thermoplastic resin is obtained. A method for manufacturing an embossed sheet made of thermoplastic resin to be manufactured, wherein after controlling the surface temperature of the belt before the linear pressure is applied, the thermal pressure is increased by the linear pressure applied between the third roll and the fourth roll. An emboss pattern is transferred and formed on a plastic resin sheet.

In the present invention, the surface temperature of the belt prior to the addition of the line pressure, shall be the structure for controlling the (Tg-20) ℃ or less.
Furthermore, in the present invention, the surface temperature of the belt after the addition of the line pressure, shall be the structure for controlling the (Tg-30) ℃ or less.
In the present invention, the surface temperature of the third roll, shall be the structure for controlling the following ℃ (Tg-20) ℃ over (Tg + 30).
Moreover, in this invention, it is preferable to set it as the structure which controls the linear pressure added between the said 3rd roll and the said 4th roll to 50 kg / cm or more and 250 kg / cm or less.
In the present invention, it is preferable that the thermoplastic resin embossed sheet having the embossed pattern transferred thereon is peeled off from the belt and then transferred to a warp correction roll.
Moreover, in this invention, it is preferable to set it as the structure which controls the surface temperature of the said curvature correction roll to (Tg-30) degreeC or more and (Tg + 10) degreeC or less.

The thermoplastic resin embossed sheet manufacturing apparatus according to the present invention includes a first roll and a second roll in which a metal belt is stretched on a peripheral surface, and an emboss pattern is formed on the peripheral surface. A third roll disposed opposite to the circumferential surface of the first roll via the belt; a fourth roll having a circumferential surface opposed to the circumferential surface of the third roll via the belt; Linear pressure control means for controlling the linear pressure applied between the roll and the fourth roll; and belt temperature control means for controlling the surface temperature of the belt before the linear pressure is applied at least between the third roll and the fourth roll. The emboss pattern is transferred to the molten thermoplastic resin sheet conveyed between the first roll and the third roll with a linear pressure applied between the third roll and the fourth roll. form And said third roll, the surface temperature (Tg-20) ℃ over (Tg + 30) ℃ is controlled below, the belt temperature controlling means, the surface temperature of the belt prior to the addition of the line pressure, (Tg The temperature of the belt is controlled to −20) ° C. or lower, and the surface temperature of the belt after applying the linear pressure is controlled to (Tg−30) ° C. or lower .

  According to the present invention, the surface temperature of the belt before the linear pressure is applied between the third roll and the fourth roll is controlled, and the surface opposite to the contact surface of the third roll of the thermoplastic resin sheet is cooled and solidified. By transferring the emboss pattern after the emboss pattern is transferred, the emboss pattern can be efficiently transferred and formed at a high transfer rate without causing a defective appearance such as a bank defect even if the thermoplastic resin sheet for transferring the emboss pattern is relatively thick. .

It is the schematic which notched a part which shows the manufacturing apparatus which manufactures the thermoplastic resin embossed sheet which concerns on one Embodiment of this invention. It is the schematic which partially cut off which shows the manufacturing apparatus of the reference example for demonstrating this invention.

Hereinafter, the manufacturing method of the embossed sheet made of thermoplastic resin in the present invention will be described with reference to the drawings.
In the present embodiment, the thermoplastic resin sheet 11 that transfers the embossed pattern to the surface is exemplified by a two-layer sheet configuration including a transfer surface layer and a base material layer, but is not limited to two layers. Applicable to multiple layers.

[Configuration of manufacturing equipment]
In FIG. 1, reference numeral 100 denotes a manufacturing apparatus. This manufacturing apparatus 100 is a single-belt type apparatus that directly forms a thermoplastic resin embossed sheet 21 by transferring an emboss pattern onto a thermoplastic resin sheet 11. .
The manufacturing apparatus 100 includes a metal endless belt 15 wound around the T-die 12 of the extruder, the first roll 13, the second roll 14, and the auxiliary roll 18, and the metal endless belt 15 through the metal endless belt 15. A third roll 16 for forming an emboss pattern in contact with the first roll 13, a warp correction roll 17 provided in the vicinity of the third roll 16, and a thermoplastic resin sheet 11 and metal on the peripheral surface of the third roll 16 A fourth roll 19 that is in contact with the endless belt 15 and applies linear pressure to the third roll 16; a plurality of transport rolls 20; a linear pressure control means (not shown); and a temperature control means 30. Configured.

  The first roll 13 may be a metal roll, and the surface thereof may be covered with an elastic material 25 such as silicone rubber.

The metal endless belt 15 is made of, for example, stainless steel.
The thickness of the metal endless belt 15 is arbitrary, but is preferably 0.1 mm to 1.5 mm, for example. That is, when it is thinner than 0.1 mm, the strength is weakened and the durability is deteriorated. If it is thicker than 1.5 mm, it is necessary to increase the diameters of the first roll 13, the second roll 14, and the auxiliary roll 18 around which the metal endless belt 15 is wound, which increases the size of the apparatus. In addition, the efficiency of heating and cooling deteriorates and the manufacturing cost increases. From these, it is preferable to set the thickness dimension to 0.1 mm to 1.5 mm.
At least one of the first roll 13, the second roll 14, and the auxiliary roll 18 has a rotation shaft connected to a rotation driving means (not shown), and moves the metal endless belt 15 in a rotating manner.

The third roll 16 for forming an emboss pattern has a mold 32 for forming an emboss pattern on the outer peripheral surface thereof. The mold 32 has an uneven shape corresponding to a triangular prism having a pitch of 150 μm, an apex angle of 90 °, and a depth of 75 μm, for example.
The third roll 16 has a metal endless belt 15 between the first roll 13 and the second roll 14 that is recessed inward so that the metal endless belt 15 is held in a part of the outer peripheral surface thereof. Placed in position. That is, at the time of manufacturing the thermoplastic resin embossed sheet 21, the metal endless belt 15 between the first roll 13 and the second roll 14 is meandered so as to wrap around a part of the outer peripheral surface of the third roll 16. I am letting.
It is preferable that the surface temperature of the third roll 16 is controlled to (Tg-20) ° C. or higher and (Tg + 30) ° C. or lower.
That is, if the temperature is lower than (Tg−20) ° C., the flowability of the resin on the side to which the embossed pattern is transferred may be lowered and a high transfer rate may not be obtained. This is because there is a risk of hindering peeling.
As a specific configuration for controlling the temperature, a configuration in which a fluid or the like can be circulated therein and a surface temperature is controlled by the circulation of the fluid may be applied.

The 4th roll 19 is arrange | positioned so that the thermoplastic resin sheet 11 may be pressed with respect to the 3rd roll 16 for emboss pattern formation from the back surface side of metal endless belts 15. FIG.
The fourth roll 19 is provided with linear pressure control means (not shown). This linear pressure control means controls the pressure for pressing the fourth roll 19.
The linear pressure control means has a cylinder that supports the fourth roll 19 such as a hydraulic type or a pneumatic type, and presses the fourth roll 19 by controlling the cylinder.
The pressing condition of the fourth roll 19 is preferably 50 kg / cm or more and 250 kg / cm or less in linear pressure.
That is, if the linear pressure is lower than 50 kg / cm, there is a risk that the transfer is not sufficiently performed and a high transfer rate may not be obtained. This is because the facility may be enlarged.

The temperature control means 30 includes a first temperature control means 30A provided upstream of the contact surface between the third roll 16 and the fourth roll 19 in the sheet conveying direction, and the third roll 16 and the fourth roll 19. Second temperature control means 30B disposed downstream of the contact surface in the sheet conveying direction.
The first temperature control means 30A is provided between the contact surface between the first roll 13 and the third roll 16 and the contact surface between the third roll 16 and the fourth roll 19 (that is, the third roll 16 and the fourth roll 16). The surface temperature of the metal endless belt 15 before applying linear pressure between the rolls 19 is controlled to (Tg−20) ° C. or lower.
That is, when the surface temperature of the metal endless belt 15 at this position is higher than (Tg-20) ° C., when an emboss pattern is transferred and formed on a relatively thick thermoplastic resin sheet 11, the appearance of a bank mark or the like This is because a defect occurs and the yield cannot be improved, and the thermoplastic resin sheet 11 is not sufficiently cooled and solidified, so that the propagation of the pressing force is deteriorated and the transfer rate may be lowered.
Further, the second temperature control means 30B is provided on the downstream side in the conveying direction of the thermoplastic resin sheet 11 with respect to the position of the contact surface between the third roll 16 and the fourth roll 19 (that is, the third roll 16 and the fourth roll). The surface temperature of the metal endless belt 15 is adjusted to (Tg−30) ° C. or lower after applying linear pressure between 19).
That is, when the surface temperature of the metal endless belt 15 at this position is higher than (Tg-30) ° C., the thermoplastic resin sheet 11 is not sufficiently cooled and solidified, and the transferred embossed pattern, particularly the prism shape, is distorted. This is because the embossed pattern once transferred may be elastically recovered and the transfer rate may be lowered, and an appearance defect such as a peeling mark may occur when peeling from the third roll.

The warp correction roll 17 is disposed in a state in which the thermoplastic resin sheet 11 to which the emboss pattern is transferred is peeled off from the third roll 16 and wound on the opposite side of the winding around the third roll 16.
For example, the warp correction roll 17 is configured such that a fluid can flow therethrough, and the outer peripheral surface can be adjusted to a predetermined temperature by the flowing fluid.
The surface temperature of the warp correction roll 17 is preferably (Tg-30) ° C. or higher and (Tg + 10) ° C. or lower, preferably (Tg−25) ° C. or higher and (Tg + 5) ° C. or lower.
That is, if the surface temperature of the warp correction roll 17 is lower than (Tg-30) ° C., the warp correction may be insufficient, and if it is higher than (Tg + 10) ° C., the warp correction becomes excessive, This is because adhesion to the surface may occur.

[Configuration of thermoplastic resin sheet]
Next, the thermoplastic resin sheet 11 that transfers and forms the thermoplastic resin embossed sheet 21 in the present embodiment will be described.
The thermoplastic resin sheet 11 is a laminated sheet provided with a base layer made of thermoplastic resin and a transfer surface layer having a transfer surface on which the emboss pattern is formed by transfer on the surface of the base material layer. . The emboss pattern is transferred to the transfer surface layer of the thermoplastic resin sheet 11 by the manufacturing apparatus 100, and the thermoplastic resin embossed sheet 21 is manufactured.
Thermoplastic resins include amorphous thermoplastic resins such as polystyrene, polycarbonate, polyacrylic acid, polymethyl methacrylate, cyclic polyolefin (COC (Cyclo-Olefin Copolymer), COP (Cycro-Olefin Polymer)), and crystals such as polypropyne. A thermoplastic resin can be used. An amorphous thermoplastic resin is preferred.
The base material layer and the transfer surface layer are not limited to using the same thermoplastic resin, and different materials may be used.

The thermoplastic resin sheet 11 may be made of a material having a glass transition point (Tg) of the transfer surface layer that is lower by 1 ° C. or more than the Tg of the base material layer in order to improve the transfer rate.
Here, as a method of lowering the glass transition point of the transfer surface layer from the base material layer, a glass transition point depressant is added to the same thermoplastic resin as the base material layer, and a thermoplastic resin different from the base material layer is transferred. You may use for a surface layer. Specifically, when polycarbonate is used for the base material layer, polystyrene is used for the transfer surface layer. When cyclic polyolefin (COC) is used for the base material layer, cyclic polyolefin (COP) is used for the transfer surface layer. Is preferred.
The thermoplastic resin sheet 11 does not use a material whose Tg of the transfer layer is lower by 1 ° C. or more than the Tg of the base material layer in order to improve the transfer rate, but with respect to the thermoplastic resin 100 in mass ratio. You may use what contained an easy-sliding additive 0.05-0.5, Preferably it is 0.06-0.4.
That is, when the slipperiness additive is less than 0.05 by mass ratio with respect to the thermoplastic resin 100, the mobility of the resin of the transfer surface layer in the thermoplastic resin sheet 11 during transfer is impaired, and transfer efficiency This is because an improvement in appearance cannot be expected, and when the amount of the slipperiness additive is more than 0.5 by mass with respect to the thermoplastic resin 100, there is a possibility that appearance defects due to bleeding may occur.
As the slippery additive, for example, saturated fatty acid amide, unsaturated fatty acid amide, substituted fatty acid amide, bis fatty acid amide and the like can be used.
In order to further improve the transfer rate of the thermoplastic resin sheet 11, the Tg of the transfer layer is lower by 1 ° C. or more than the Tg of the base material layer, and a slippery additive is contained in the above range. preferable.

Moreover, as a base material layer, what has thermoplastic resin whose Tg is 50 to 200 degreeC, for example, preferably 60 to 190 degreeC as a main component is suitable, for example.
That is, if the Tg of the base material layer is lower than 50 ° C., the heat resistance may be inferior, and if it is higher than 200 ° C., the extrusion film formation itself may be difficult.
As the thermoplastic resin sheet 11 having such a base material layer and a transfer surface layer, for example, a polystyrene resin or a polycarbonate resin is used as the thermoplastic resin, and a fatty acid amide is preferably used as the slippery additive. It is done.

Here, when a glass transition point depressant is blended, when a polystyrene resin is used as the thermoplastic resin, liquid paraffin is preferably used as the glass transition point depressant. In this case, the transfer surface layer may contain a glass transition temperature of 0.3 to 5 and preferably 0.35 to 4.95 with respect to the polystyrene resin 100 by mass ratio. That is, when the glass transition point depressant is less than 0.3 by weight with respect to the polystyrene resin 100, the fluidity of the transfer surface layer in the thermoplastic resin sheet 11 during transfer is impaired, and improvement in transfer efficiency can be expected. This is because, when the amount is more than 5, the uniform mixing becomes difficult, and the improvement during the production may not be achieved.
When a polycarbonate resin is used as the thermoplastic resin, caprolactone, phosphate ester flame retardant, polycarbonate oligomer or derivative thereof, polybutylene terephthalate, or poly (butylene adipate / terephthalate) is preferably used as the glass transition point depressant. Used. In this case, the transfer surface layer may contain a glass transition point depressant in a mass ratio of 0.01 or more, preferably 0.02 or more with respect to the polycarbonate resin 100. That is, if the glass transition point depressant is less than 0.01 by mass ratio with respect to the polycarbonate resin 100, the fluidity of the transfer surface layer in the thermoplastic resin sheet 11 during transfer is impaired, and improvement in transfer efficiency cannot be expected. Because. With respect to the upper limit, there is no particular limitation as long as Tg does not become 50 ° C. or lower in the case of polycarbonate resin.
In particular, when the slippery additive is used in combination with the glass transition point depressant in a mass ratio of 0.05 to 0.5 with respect to the thermoplastic resin 100, a fatty acid amide is used as the slippery additive. Preferably used.

[Manufacture of thermoplastic resin sheet]
Next, the operation of manufacturing the thermoplastic resin embossed sheet 21 using the manufacturing apparatus 100 described above will be described.
First, the temperature control means 30 controls the metal endless belt 15 to a predetermined temperature. Specifically, from the contact surface between the first roll 13 and the third roll 16 to the contact surface between the third roll 16 and the fourth roll 19 (between the third roll 16 and the fourth roll 19). The surface temperature before applying linear pressure is controlled to (Tg-20) ° C. or lower by the first temperature control means 30A. Further, of the contact surface between the third roll 16 and the metal endless belt 15 via the thermoplastic resin sheet 11, the position of the thermoplastic resin sheet 11 is more than the position of the contact surface between the third roll 16 and the fourth roll 19. The surface temperature of the metal endless belt 15 on the downstream side in the conveying direction (after applying linear pressure between the third roll 16 and the fourth roll 19) is determined by the second temperature control means 30B (Tg-30). Control below ℃.
Then, the thermoplastic resin sheet 11 in which the molten base material layer and the transfer surface layer are laminated from the T die 12 of the extruder is rotated at the position of the rotating third roll 16 and the first roll 13. Introduced between the endless belt 15.

Then, between the rotating third roll 16 and the rotating metal endless belt 15, the first temperature control means 30 </ b> A causes the metal endless belt 15 to be (Tg−20) ° C. or less at the base material layer side. Then, it is conveyed to the position of the fourth roll 19 while being cooled. The thermoplastic resin sheet 11 is pressed by the fourth roll 19 at a linear pressure of 50 kg / cm to 250 kg / cm, and the mold 32 of the third roll 16 is sufficiently transferred.
Further, between the rotating third roll 16 and the rotating metal endless belt 15, the second temperature control means 30 </ b> B causes the metal endless belt 15 to be (Tg−30) ° C. or less to the base material layer side. And is peeled off from the metal endless belt 15 while being wound around the third roll 16.
Thereafter, the thermoplastic resin sheet 11 is peeled off from the third roll 16 so as to be wound up by the warp correction roll 17, and the side opposite to the side wound up by the third roll 16 by the warp correction roll 17, that is, the base material. The thermoplastic resin with the embossed pattern transferred to the thermoplastic resin sheet 11 by winding it in a state where the layer side is inside, removing the warp before the thermoplastic resin sheet 11 is completely solidified, and transporting it with the transport roll 20 A resin embossed sheet 21 is manufactured.

[Effects of Embodiment]
In this embodiment, after the surface opposite to the third roll 16 is cooled and solidified by the metal endless belt 15 in the thermoplastic resin sheet 11 before the linear pressure is applied between the third roll 16 and the fourth roll 19. The emboss pattern is transferred and formed.
For this reason, even when the emboss pattern is transferred and formed on the relatively thick thermoplastic resin sheet 11, the emboss pattern can be transferred and formed at a high transfer rate without causing appearance defects such as bank marks.
In this embodiment, in the thermoplastic resin sheet 11 after transferring the emboss pattern by applying linear pressure between the third roll 16 and the fourth roll 19, from the side of the base material layer opposite to the third roll 16. The metal endless belt 15 is further cooled and solidified.
For this reason, the thermoplastic resin sheet 11 after the emboss pattern is formed is easily peeled off from the metal endless belt 15, and the thermoplastic resin embossed sheet 21 having a high transfer rate can be manufactured satisfactorily.
Further, in the present embodiment, a warp correction roll 17 is provided to add a warp on the side opposite to the warp during the transfer of the emboss pattern, thereby removing the warp during the transfer.
For this reason, it is possible to manufacture a good thermoplastic resin embossed sheet 21 that is not warped and can be sufficiently applied to, for example, a light diffusion sheet used in a liquid crystal display device.
In particular, as described above, according to the embodiment, as the thermoplastic resin sheet 11 on which the embossed pattern is formed, a predetermined transfer surface layer (for example, Tg is easily transferred onto the surface of the base material layer). A thermoplastic resin sheet 11 on which a layer lowered by 1 ° C. or more from the base material layer or a layer containing a slippery additive) is used is used.
For this reason, the stress required for transfer is easily propagated, and even when the temperature on the base layer side is lowered, the fluidity on the transfer surface layer side is relatively secured, and in the manufacturing method using the conventional metal endless belt 15, A high transfer rate that was not obtained can be obtained, and since the transfer rate is high, the configuration of the manufacturing apparatus 100 can be easily simplified, and the yield can be improved.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that modifications and improvements within the scope of achieving the objects and effects of the present invention are included in the contents of the present invention. Nor. Further, the specific structure, shape, etc. in carrying out the present invention are not problematic as other structures, shapes, etc., within the scope of achieving the objects and effects of the present invention.

For example, the thermoplastic resin sheet 11 forming the emboss pattern is not limited to the multilayer structure sheet used in the present embodiment, and a single layer structure sheet may be used.
Further, although the warp correction roll 17 is provided, the warp correction roll 17 may not be provided if the warp requirement of the thermoplastic resin embossed sheet 21 as a product is not severe.

  In addition, the specific configuration and form in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples produced under various conditions.
In addition, this invention is not limited to the content of an Example etc. at all.

[Example 1]
(material)
As a raw material of the base material layer constituting the thermoplastic resin sheet, a product name GPPS G9504 (Tg = 100 ° C., MFR = 1.5 g / 10 min (200 ° C.)) manufactured by PS Japan Co., Ltd. was used as the thermoplastic resin raw material. This was dried at 95 ° C. for 2 hours with a hot air dryer.
As a raw material for the transfer surface layer constituting the thermoplastic resin sheet, master pellets (Tg = 92.1 ° C.) containing liquid paraffin 2 with respect to the same thermoplastic resin raw material 100 as the base material layer by mass ratio are dried with hot air. What was dried at 95 ° C. for 2 hours in a machine was used.
(manufacturing device)
The above-described manufacturing apparatus shown in FIG. 1 under the following conditions supplies the above-described base material layer raw material and transfer surface layer raw material to the hopper of the extruder, melt-plasticizes in the extruder, and then feedblock The thermoplastic resin sheet, which is a two-layered resin film laminated in a molten state, was extruded from the die lip. The embossed pattern was transferred to the thermoplastic resin sheet under the conditions shown below to produce a thermoplastic resin embossed sheet having a total thickness of 2.0 mm.
(A) Single screw extruder for substrate layer: Diameter dimension 75 mm (L / D = 28)
(B) Single screw extruder for transfer surface layer: Diameter 50 mm (L / D = 28)
(C) Coat hanger die: 900mm width, lip opening 3.5mm
(D) Extrusion conditions:
(a) Temperature of the cylinder part of the extruder; 210 to 230 ° C
(b) Adapter section: 230 ° C
(c) Die; 230 ° C
(d) 75 mm extrusion rate: 120 kg / h
(e) 50 mm extrusion rate: 7 kg / h
(f) Sheet take-up speed: 1.3 m / min
(g) Resin temperature: 243 ° C
(E) Belt machine:
(a) Stainless steel belt; thickness 0.8mm, width 900mm
(b) Belt surface roughness Ra; 0.015 μm
(c) 1st roll: roll coated with acrylonitrile-butadiene rubber (NBR) with a thickness of 10 mm and JIS K6301 A type 60 ° (diameter 600 mm)
(d) Second roll: Double pipe spiral metal roll (diameter 600 mm)
(e) Third roll; double pipe spiral roll (diameter 600 mm) with 6666 prisms with apex angle 90 ° pitch 150 μm and depth 75 μm on the surface.
(f) Fourth roll: JIS K6301 A-type roll coated with 60 ° NBR (diameter 300 mm).

(Comparison evaluation)
(A) Transfer rate:
The height dimension H of the transferred prism of the manufactured thermoplastic resin embossed sheet was measured, and the transfer rate [%] was calculated using the following equation (1). D in this formula (1) is the depth of the prism plate.
Transfer rate = H / D × 100 (1)
(B) Warpage rate:
The center of one side of a 500 mm square prism sheet is suspended vertically, and a ruler is applied to both sides near the lower end of the sheet. Measure the maximum separation distance Y between the ruler and the sheet surface with a caliper or depth gauge to 0.1 mm. The warpage rate [%] was calculated using the following equation (2).
Warpage rate = Y / 500 × 100 (2)
These results are shown in Tables 1 and 2 below.

[Examples 2-7, Comparative Examples 1-3]
As the master pellets of the transfer surface layer in Example 1, the same production conditions as in Example 1 were used, with the addition of liquid paraffin as the glass transition point depressant and various slippery additives added as appropriate. The embossed pattern was transferred to produce the thermoplastic resin embossed sheets of Examples 2-7 and Comparative Examples 1-3.
These results are shown in Tables 1 and 2.

[Reference Example 1]
A thermoplastic resin embossed sheet X embossed and transferred using the same material as in Example 1 was manufactured using a manufacturing apparatus under the following conditions shown in FIG.
(manufacturing device)
(A) Single screw extruder for substrate layer: Diameter dimension 75 mm (L / D = 28)
(B) Single screw extruder for transfer surface layer: Diameter 50 mm (L / D = 28)
(C) Coat hanger die: 900mm width, lip opening 3.5mm
(D) Extrusion conditions:
(a) Temperature of the cylinder part of the extruder; 210 to 230 ° C
(b) Adapter section: 230 ° C
(c) Die; 230 ° C
(d) 75 mm extrusion rate: 120 kg / h
(e) 50 mm extrusion rate: 7 kg / h
(f) Sheet take-up speed: 1.3 m / min
(g) Resin temperature: 243 ° C
(E) First cooling roll 51: diameter size 300 mm, surface temperature 60 ° C.
(F) Second prism roll 52: diameter 450 mm, surface temperature 95 ° C. (A sheet is attached at higher temperatures, and stable film formation is impossible.)
(G) Third cooling roll 53: diameter 450 mm, surface temperature 70 ° C.
(H) Linear pressure of the first cooling roll and the second prism roll: 200 kg / cm

[result]
From the results shown in Tables 1 and 2 above, a high transfer rate could not be obtained when deviating from the claims regarding the manufacturing method as in Comparative Examples 1 to 3.
On the other hand, in Examples 1 to 7, a good emboss pattern was obtained with high transfer without producing bank marks or peeling marks.
In the case of Reference Example 1 manufactured using the manufacturing apparatus shown in FIG. 2, when the sheet thickness was 2 mm, the transfer rate was 45%, and a high transfer rate was not obtained.

  The embossed sheet made of thermoplastic resin obtained by the present invention is suitable for a light diffusing sheet in a reflector field, a fashion field, an architectural field, a display device, and the like.

DESCRIPTION OF SYMBOLS 11 ... Thermoplastic resin sheet 13 ... 1st roll 14 ... 2nd roll 15 ... Metal endless belt (belt)
DESCRIPTION OF SYMBOLS 16 ... 3rd roll 19 ... 4th roll 21 ... Thermoplastic resin embossed sheet 30 ... Temperature control means 30A ... 1st temperature control means 30B ... 2nd temperature control means 100 ... Manufacturing apparatus

Claims (5)

A first roll and a second roll in which a metal belt is wound around the peripheral surface;
An embossed pattern is formed on the peripheral surface, and the peripheral surface is disposed opposite to the peripheral surface of the first roll via the belt;
A fourth roll having a circumferential surface opposed to the circumferential surface of the third roll via the belt;
Using a manufacturing apparatus comprising linear pressure control means for controlling the linear pressure applied between the third roll and the fourth roll, and belt temperature control means for controlling the surface temperature of the belt,
The thermoplastic resin sheet in a molten state is passed between the first roll and the third roll and then passed between the third roll and the fourth roll, and an emboss pattern is transferred to the thermoplastic resin sheet. A method for producing an embossed sheet made of thermoplastic resin for producing an embossed sheet made of thermoplastic resin,
After controlling the surface temperature of the belt before applying the linear pressure, an emboss pattern is transferred and formed on the thermoplastic resin sheet by the linear pressure applied between the third roll and the fourth roll ,
The surface temperature of the belt before applying the linear pressure is controlled to (Tg-20) ° C. or lower,
The surface temperature of the belt after applying the linear pressure is controlled to (Tg-30) ° C. or lower,
The surface temperature of the third roll is controlled to (Tg-20) ° C or higher and (Tg + 30) ° C or lower . A method for producing an embossed sheet made of thermoplastic resin. A method for producing a thermoplastic resin embossed sheet mounting serial to claim 1,
A linear pressure applied between the third roll and the fourth roll is controlled to 50 kg / cm or more and 250 kg / cm or less. A method for producing an embossed sheet made of a thermoplastic resin. A method for producing an embossed sheet made of a thermoplastic resin according to claim 1 or 2 ,
The thermoplastic resin embossed sheet to which the embossed pattern has been transferred is peeled off from the belt, and then conveyed over a warp correction roll. A method for producing an embossed sheet made of a thermoplastic resin according to claim 3 ,
A method for producing an embossed sheet made of a thermoplastic resin, wherein the surface temperature of the warp correction roll is controlled to (Tg-30) ° C. or higher and (Tg + 10) ° C. or lower. A first roll and a second roll in which a metal belt is wound around the peripheral surface;
An embossed pattern is formed on the peripheral surface, and the peripheral surface is disposed opposite to the peripheral surface of the first roll via the belt;
A fourth roll having a circumferential surface opposed to the circumferential surface of the third roll via the belt;
Linear pressure control means for controlling the linear pressure applied between the third roll and the fourth roll;
Belt temperature control means for controlling a surface temperature of the belt before a linear pressure is applied between at least the third roll and the fourth roll, and
An embossed pattern is transferred and formed on the molten thermoplastic resin sheet conveyed between the first roll and the third roll with a linear pressure applied between the third roll and the fourth roll ,
The third roll has a surface temperature controlled to (Tg-20) ° C. or higher and (Tg + 30) ° C. or lower,
The belt temperature control means includes
The surface temperature of the belt before applying the linear pressure is controlled to (Tg-20) ° C. or lower,
The apparatus for producing an embossed sheet made of a thermoplastic resin , wherein the surface temperature of the belt after applying the linear pressure is controlled to (Tg-30) ° C. or lower .

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