JP2011068041A - Apparatus and method for producing resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an apparatus for producing a resin sheet which certainly forms fine unevenness on the surface of the resin sheet by using various thermoplastic resins. <P>SOLUTION: The apparatus 1 for producing the resin sheet has a temperature adjustment roll 4 having a roll body 4a made of a metal, a driving device 6 for driving the temperature adjustment roll 4, an endless metallic band-shaped body 4c on an outer surface of which unevenness of a shape corresponding to the unevenness t be formed on a resin sheet surface is formed, a raw material 4b which is provided at least at either of an outer peripheral surface of the temperature adjustment roll 4 and an inner peripheral surface of the endless metallic band-shaped body 4c and has lower magnetic permeability than that of the endless metallic band-shaped body 4c, a device for giving unevenness on one surface of a thermoplastic resin sheet 3 by bringing the resin sheet 3 into contact with the outer peripheral surface of the endless metallic band-shaped body 4c during rotation of the temperature adjustment roll 4 while bringing the endless metallic band-shaped body 4c into contact with the temperature adjustment roll 4 via the raw material 4b with lower magnetic permeability and an electromagnetic induction heater 7 for heating the endless metallic band-shaped body 4c. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin sheet manufacturing apparatus and manufacturing method for imparting unevenness to one side of a resin sheet, and more specifically, the unevenness of the outer surface of an endless metal strip heated by high frequency induction heating is reduced. It is related with the manufacturing apparatus and manufacturing method of a resin sheet which give an unevenness to one side of a resin sheet by giving to one side.

  Conventionally, synthetic resin films having irregularities on the surface have been widely used for solar cell sealing films, liquid crystal display optical films, laminated glass inner films, and the like. In the production of such a synthetic resin film, the so-called two-roll method in which the molten resin extruded from the die by melt extrusion is sandwiched between a mold roll having an uneven surface and a pressure-bonding roll, or the uneven surface is formed on the surface. Various methods such as a method of heat-pressing the applied transfer material onto a synthetic resin film are used.

  For example, the following Patent Document 1 discloses a thermoplastic resin sheet processing apparatus schematically shown in FIG. As shown in FIG. 8, in the sheet processing apparatus 101, the thermoplastic resin sheet 103 wound around the supply roll 102 is fed out. The thermoplastic resin sheet 103 is guided between the mold roll 104 and the pressure roll 105. Concavities and convexities are provided on the outer peripheral surface of the mold roll 104. A heating device 106 is provided on the upstream side in the rotational direction of the mold roll 104 from the portion where the thermoplastic resin sheet 103 is supplied to the outer surface of the mold roll 104. The mold roll 104 made of metal is heated by the heating device 106. Therefore, it is said that the unevenness on the outer surface of the mold roll 104 can be reliably transferred to the thermoplastic resin sheet 103 by sandwiching the thermoplastic resin sheet 103 between the mold roll 104 and the pressure-bonding roll 105. .

  Here, an endless belt 109 is stretched around the pressure-bonding roll 105 and the rolls 107 and 108. The endless belt 109 is in close contact with the thermoplastic resin sheet 103 on the surface of the mold roll 104. It is said that the endless belt 109 cools the thermoplastic resin sheet 103 provided with irregularities, and the thermoplastic resin sheet 103 can be peeled off from the mold roll 104 without difficulty.

  On the other hand, Patent Document 2 below describes a method using high-frequency induction heating as an apparatus for heating a mold roll in transferring a fine shape onto a thermoplastic resin film using such a mold roll.

JP-A-10-291251 Japanese Patent No. 4232608

  According to the thermoplastic resin sheet processing apparatus 101 described in Patent Document 1, a thermoplastic resin sheet having fine irregularities on the surface can be obtained. However, in the thermoplastic resin sheet processing apparatus 101 described in Patent Document 1, a heating apparatus that applies radiant heat is used as the heating apparatus 106. Therefore, energy efficiency was not sufficient.

  Further, Patent Document 1 describes that, by using a thermoplastic resin composition obtained by adding a plasticizer to soft polyvinyl chloride having a relatively low viscosity among thermoplastic resins, it is described that the unevenness transferability can be improved. . However, in the sheet processing apparatus 101 described in Patent Document 1, when a thermoplastic resin having a relatively high viscosity is used, it is difficult to reliably transfer fine irregularities onto the surface of the thermoplastic resin sheet. Moreover, in order to reduce a viscosity, the additive etc. which have a viscosity reduction effect | action must be mix | blended, There existed a restriction | limiting in the composition of the thermoplastic resin which can be used, or a thermoplastic resin composition.

  On the other hand, the method described in Patent Document 2 is excellent in thermal efficiency because the mold roll itself is heated using high-frequency induction heating. However, heat easily diffuses in a metal mold roll, and a considerable amount of power had to be supplied to maintain the temperature of the mold roll surface at a relatively high temperature suitable for uneven transfer. . Moreover, even if it uses the manufacturing method of patent document 2, it was difficult to transfer the fine unevenness | corrugation to the thermoplastic resin sheet surface with high precision for use. For example, in the convex-concave cross section of the concavo-convex portion, the maximum aspect ratio corresponding to the ratio between the height and the width is about 0.5 at most.

  The objective of this invention is related with the manufacturing apparatus and manufacturing method of a resin sheet which can eliminate the fault of the prior art mentioned above and can form fine unevenness | corrugation on the surface reliably using various thermoplastic resins.

  The apparatus for producing a resin sheet according to the present invention is an apparatus for producing a resin sheet having an uneven surface on one side, and includes a temperature adjusting roll having a roll body made of metal, and a rotary drive for rotating the temperature adjusting roll. 1, an endless metal strip in which irregularities corresponding to the irregularities formed on the surface of the resin sheet are formed on the outer surface, an outer peripheral surface of the temperature control roll, and an endless metal strip Provided on at least one of the inner peripheral surface, the material having a lower magnetic permeability than the endless metal strip, and the endless metal strip in contact with the temperature control roll through the material having a low permeability An apparatus for imparting irregularities to one surface of the resin sheet by bringing the resin sheet into contact with the outer peripheral surface of the endless metal strip while rotating the temperature control roll, and the outer periphery of the endless metal strip Wherein provided on the upstream side of a position where the resin sheet is contacting the electromagnetic induction heating apparatus for heating the endless metal strip in.

  On the specific situation with the manufacturing apparatus of the resin sheet which concerns on this invention, the said raw material with low magnetic permeability is integrally formed in the outer peripheral surface of the said roll main body of the said temperature control roll. In this case, not only can the manufacturing apparatus be reduced in size, but also a magnetic field for generating an eddy current in the endless metal strip can be confined in the endless metal strip by a material having low permeability.

  According to another specific aspect of the resin sheet manufacturing apparatus according to the present invention, the endless metal strip is integrally provided on the outer peripheral surface of the material having a low magnetic permeability, whereby the roll body is provided with: The material with low magnetic permeability and the endless metal strip are integrated. In this case, since the material with low magnetic permeability and the endless metal strip are integrated into the roll body, the manufacturing apparatus can be reduced in size, and the number of members used and the cost of the manufacturing apparatus can be reduced. Reduction can be achieved.

  In still another specific aspect of the resin sheet manufacturing apparatus according to the present invention, the endless metal strip is an endless metal belt, the temperature control roll has a plurality of temperature control rolls, and the endless metal belt is It is laid on multiple temperature control rolls. In this case, the temperature of the endless metal strip can be controlled with higher accuracy.

  In another specific aspect of the resin sheet manufacturing apparatus according to the present invention, the apparatus for imparting irregularities to one surface of the resin sheet has a pressure-bonding roll that press-contacts the resin sheet and the outer peripheral surface of the endless metal strip. The pressure roll is disposed so as to have a gap with the temperature control roll, and the resin sheet is pressure-bonded to the pressure roll on the outer surface side of the metal strip in the gap.

  In the resin sheet manufacturing apparatus according to the present invention, the apparatus for imparting irregularities to one surface of the resin sheet is not limited to the configuration having the temperature control roll and the pressure roll, and may be an edge pinning apparatus or an air knife. It may be.

  In still another specific aspect of the resin sheet manufacturing apparatus according to the present invention, the apparatus further includes a melt extrusion apparatus that extrudes molten resin into a sheet shape, and is provided on one surface of the flat resin sheet extruded by the melt extrusion apparatus. Unevenness is imparted. In this case, since a sheet-like body that has been melt-extruded and has a relatively high temperature from the beginning is used, unevenness can be imparted to the resin sheet surface more easily and with high accuracy.

  In still another specific aspect of the resin sheet manufacturing apparatus according to the present invention, the temperature control roll has a hollow portion inside a roll body made of metal, and a refrigerant supply device for supplying a refrigerant to the hollow portion Is further provided. In this case, the roll body can be cooled by the refrigerant, and the resin sheet provided with irregularities can be easily separated from the temperature control roll.

  In still another specific aspect of the apparatus for producing a resin sheet according to the present invention, in the irregularities on the outer surface of the endless metal strip, the aspect ratio of the cross section of the convex portion is 0.5 or more. According to the present invention, by using such an endless metal strip, it is possible to provide a resin sheet having a concavo-convex shape in which the aspect ratio of the convex section is 0.5 or more.

  The method for producing a resin sheet according to the present invention is a production method using the apparatus for producing a resin sheet according to the present invention, the step of driving the endless metal strip and the temperature control roll with a driving device, and the endless metal The step of heating the strip by the electromagnetic induction heating device, and the downstream end of the endless metal strip in the transport direction of the endless metal strip transported by the driving device from the position heated by the electromagnetic induction heating device, At least a part of the endless metal strip in the transport direction while bringing the endless metal strip into contact with the temperature control roll via the heat insulating material in at least a part of the transport direction of the endless metal strip. In the region, the one surface of the resin sheet is brought into contact with the outer peripheral surface of the endless metal strip, and the one surface of the resin sheet is provided with unevenness, and the unevenness is attached. Has been said resin sheet and a step of removing from said endless metal strips on the outer peripheral surface of the temperature regulation roll.

  According to the resin sheet manufacturing apparatus and the manufacturing method of the present invention, the endless metal strip is heated by an electromagnetic induction heating device with excellent thermal efficiency, and the heated endless metal strip is heated through a material having a low magnetic permeability. While one side of the resin sheet is in contact with the outer peripheral surface of the endless metal strip while the temperature control roll is rotating while being in contact with the adjusting roll, the outer peripheral surface of the endless metal strip is on one side of the resin sheet Can be transferred reliably and with high accuracy. That is, by using an electromagnetic induction heating device with excellent thermal efficiency, the endless metal strip is reliably heated to a temperature sufficient to transfer the irregularities with high power with a small amount of electric power. Moreover, since the endless metal strip is in contact with the roll body via a material having low permeability, the magnetic field can be concentrated in the endless metal strip, and the eddy current generated thereby is generated more efficiently. Can be made.

  Therefore, according to this invention, the resin sheet which has the unevenness | corrugation whose aspect ratio of a convex part cross section is 0.5 or more, for example, or a very fine unevenness | corrugation on one surface can be provided.

(A) is a schematic block diagram of the manufacturing apparatus of the resin sheet which concerns on one Embodiment of this invention, (b) is an enlarged view which shows the principal part, (c) is obtained by 1st Embodiment. It is a partial notch front sectional drawing which shows a resin sheet. It is a partial expanded sectional view which shows the structure of the temperature control roll used by the 1st Embodiment of this invention, a raw material with low magnetic permeability, and a metal strip. It is a partial notch sectional view which shows the application example of the resin sheet obtained by the 1st Embodiment of this invention. It is a partial notch sectional view which shows the modification of the resin sheet obtained by the 1st Embodiment of this invention. It is a schematic block diagram of the manufacturing apparatus of the resin sheet which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of the manufacturing apparatus of the resin sheet which concerns on the 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the modification of the manufacturing apparatus of the resin sheet of this invention. It is a schematic block diagram for demonstrating the conventional sheet processing apparatus of a thermoplastic resin.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

(First embodiment)
Fig.1 (a) is a schematic block diagram which shows the manufacturing apparatus of the resin sheet which concerns on the 1st Embodiment of invention, FIG.1 (b) is the elements on larger scale which show the principal part, (c) FIG. 3 is a partially cutaway front sectional view showing a resin sheet obtained in the present embodiment.

  As shown in FIG. 1A, a resin sheet manufacturing apparatus 1 includes a melt extrusion apparatus 2 that melts a thermoplastic resin. The melt extrusion device 2 melts the thermoplastic resin and extrudes it as a sheet 3. In the present embodiment, the melt extrusion apparatus 2 is used. However, in the present invention, the melt extrusion apparatus 2 may not be used, and a thermoplastic resin sheet that has been molded in advance may be used from the beginning.

  However, since the thermoplastic resin sheet 3 immediately after being extruded from the melt extrusion apparatus 2 is in a relatively high temperature state and it is easy to impart fine irregularities by transfer, it is preferable to use the melt extrusion apparatus 2. In the case of using a pre-molded thermoplastic resin sheet, it is necessary to sufficiently heat the thermoplastic resin sheet 3 to a temperature necessary for transferring fine irregularities in a later step.

  Although it does not specifically limit as a thermoplastic resin used, In this embodiment, polymethylmethacrylate is used. Examples of other thermoplastic resins include polycarbonate, polyethylene terephthalate, polyethylene terephthalate, polyvinyl butyral, ethylene vinyl alcohol resin, cycloolefin polymer, and cycloolefin copolymer.

  The thermoplastic resin sheet 3 is supplied between the temperature control roll 4 and the pressure-bonding roll 5.

  As shown in FIG.1 (b), the temperature control roll 4 has the roll main body 4a which consists of metals. Such a metal is not particularly limited, and an appropriate metal having high strength such as aluminum, stainless steel, or iron can be used. The roll body 4a is cylindrical, has a hollow portion, and is supplied with a coolant such as air from a coolant supply device (not shown).

  On the outer peripheral surface of the roll body 4a, a low relative permeability layer 4b as a material having a low permeability according to the present invention is formed. The low relative permeability layer 4b is formed so as to cover the outer peripheral surface of the roll body 4a, and therefore the low relative permeability layer 4b is integrated with the roll body 4a.

As the material having a low magnetic permeability, an appropriate material having a magnetic permeability lower than that of the endless metal band can be used. Examples of such materials include inorganic compounds such as Cr ₂ O ₃ , Al ₂ O ₃ , zirconia / calcium oxide mixture, and heat-resistant organic compounds typified by polyimide. In the present embodiment, the low relative magnetic permeability layer 4b is made of Cr ₂ O ₃ .

  The thickness of the low relative magnetic permeability layer 4b is not particularly limited, but a material with low magnetic permeability often has low thermal conductivity. If the thermal conductivity is too low, it is difficult to perform appropriate cooling between the position X and the position Z. Accordingly, the thickness is preferably 5 mm or less. Moreover, since durability will fall when too thin, it is desirable that it is 0.001 mm or more. However, these thicknesses may be appropriately adjusted depending on the material of the low relative permeability layer 4b.

  An endless metal strip 4c is formed on the outer peripheral surface of the low relative permeability layer 4b. Since the endless metal strip 4c is heated by electromagnetic induction heating, the endless metal strip 4c is preferably made of a metal material having high magnetic permeability such as nickel, a nickel alloy, or carbon steel. Those having a magnetic permeability of 2 or more are desirable. Moreover, since it consists of a metal, it is excellent in thermal conductivity and temperature control is also easy. In the present embodiment, the endless metal strip 4c is made of Ni.

  On the outer peripheral surface of the endless metal strip 4c, as shown in FIG. 1B, there are provided irregularities in which a plurality of convex portions 4d are regularly provided along the circumferential direction. The said unevenness | corrugation is corresponded in the shape which reversed the unevenness | corrugation formed in the one surface of the thermoplastic resin sheet finally obtained.

  The endless metal strip 4c is formed by a method of extrapolating the endless metal strip having the above shape to a roll body 4a having a low relative permeability layer 4b formed on the outer peripheral surface, or an outer periphery of the low relative permeability layer 4b. An appropriate method can be used, such as a method of forming an endless metal strip 4c on the surface and performing a process of providing irregularities on the surface.

  Preferably, an easily peelable material layer may be formed on the outer peripheral surface of the endless metal strip 4c, that is, the surface on which the irregularities are formed in order to facilitate the peeling of the thermoplastic resin sheet. . As such an easily peelable material, an organic material such as a fluorine-containing monomolecular film or an inorganic material such as diamond-like carbon can be used as appropriate.

  As shown in FIG. 1A, the temperature adjusting roll 4 is rotated in the direction of the arrow A shown in the figure by a driving device M such as a motor. On the other hand, the pressure roll 5 is rotatably provided, and the pressure roll 5 is disposed on the temperature adjustment roll 4 side in the gap between the temperature adjustment roll 4 and the pressure roll 5. Press. That is, the thermoplastic resin sheet 3 is sandwiched between the temperature control roll 4 and the pressure roll 5.

  The pressure roll 5 can be formed of an appropriate metal. Such a metal is not particularly limited, and examples thereof include stainless steel and iron. Furthermore, a flexible material such as rubber may be coated in order to improve the pressure-bonding property.

  The pressure roll 5 may be rotationally driven by a driving device (not shown) in the direction opposite to the arrow A direction.

  A portion where the thermoplastic resin sheet 3 is sandwiched between the temperature adjusting roll 4 and the pressure-bonding roll 5 and transfer described later is performed is defined as a position X. In order to electromagnetically heat the endless metal strip 4c at a position upstream of the position X in the rotation direction of the temperature control roll 4, that is, a position Y upstream of the endless metal strip 4c in the transport direction, the electromagnetic induction heating device 7 Is arranged. The electromagnetic induction heating device 7 has a coil through which a high-frequency current is passed, and the endless metal strip 4c made of the metal is electromagnetically heated by the magnetic field when the high-frequency current is passed through the coil to generate heat. . The degree of heating is set so that the endless metal strip 4 c heats the endless metal belt 24 to an appropriate temperature for transferring the above-described irregularities to the thermoplastic resin sheet 3.

  The position Y is not particularly limited as long as it is upstream of the position X in the transport direction of the endless metal strip 4c, that is, in the rotation direction of the temperature control roll 4, but preferably the endless heated by Y It is desirable that the metal strip 4c is in a position where it can be maintained at a temperature sufficient to transfer the shape to the resin sheet with X.

  At least one of the pressure-bonding roll 5 and the temperature control roll 4 may be formed by a barrel-shaped crown roll having a diameter at the center in the axial direction larger than the diameter at the end in the axial direction. By using at least one crown roll, it is possible to suppress dents in the central portion of the roll in the axial direction. Therefore, the accuracy of the shape of the resin sheet can be increased even in the axial center of the roll.

  A roll 13 is disposed separately from the temperature control roll 4. After the unevenness is imparted at the position X, the thermoplastic resin sheet 3 is in contact with the outer peripheral surface of the temperature control roll 4, more specifically, with the temperature control roll 4 while in contact with the outer peripheral surface of the endless metal strip 4c. It moves and is separated from the temperature control roll 4 at the position Z. The roll 8 is provided to adjust the position Z. That is, the roll 8 is set so that the thermoplastic resin sheet 3 provided with irregularities is hung and the position Z is an appropriate position.

  A manufacturing method using the resin sheet manufacturing apparatus 1 of the present embodiment will be described.

  In the present embodiment, the thermoplastic resin sheet 3 shown in FIG. 1C is finally obtained. The thermoplastic resin sheet 3 has a plurality of convex portions 3a having a rectangular cross-sectional shape along the sheet conveying direction on one surface side. The plurality of convex portions 3a are regularly arranged. As a result of the formation of the plurality of convex portions 3 a, irregularities are formed on one surface of the thermoplastic resin sheet 3. The width direction dimension W1 in the said cross section of the convex part 3a, and the position in which the some convex part 3a, 3a is provided are set to W2. Moreover, the height of the convex part 3a is set to h, and the thickness of the sheet | seat main body part except the said convex part 3a of the thermoplastic resin sheet 3 is set to t. In other words, the thermoplastic resin sheet 3 has a plurality of convex portions 3a having a height h and a width W1 on one surface side.

  In order to obtain the thermoplastic resin sheet 3 by a transfer method, the outer surface of the endless metal strip 4c is formed with convex portions 4d in which the concave portions between the plurality of convex portions 3a correspond to the convex portions.

  In production, the thermoplastic resin sheet 3 in a molten state is extruded from the melt extrusion apparatus 2, and the thermoplastic resin sheet 3 is fed between the temperature control roll 4 and the pressure-bonding roll 5. The endless metal strip 4c is heated by the electromagnetic induction heating device 7 while the temperature adjusting roll 4 is rotationally driven by the driving device M. Thereby, the endless metal strip 4c is heated to a temperature higher than that necessary for good transfer. This temperature varies depending on the material of the thermoplastic resin sheet 3 and the temperature immediately before being supplied to the temperature adjustment roll 4 of the thermoplastic resin sheet 3, but at a position X, the temperature can be satisfactorily transferred. What is necessary is just to heat.

  The heated endless metal strip 4 c moves to the position X as the temperature control roll 4 rotates. At position X, the thermoplastic resin sheet 3 is pressed against the temperature adjusting roll 4 side by the pressure-bonding roll 5. As a result, unevenness having a shape obtained by inverting the unevenness 4d on the surface of the endless metal strip 4c is transferred to the surface of the thermoplastic resin sheet 3 on the temperature adjusting roll 4 side. Thereafter, the thermoplastic resin sheet 3 moves from the position X to the position Z while being in contact with the outer peripheral surface of the temperature control roll 4, more specifically, the outer peripheral surface of the endless metal strip 4c. In this case, since a coolant such as water or oil is supplied to the inside of the roll body 4a of the temperature control roll 4, the temperature of the roll body 4a of the temperature control roll 4 decreases from the position X to the position Z. Furthermore, since the low relative permeability layer 4b and the endless metal strip 4c are also cooled, the thermoplastic resin sheet 3 can be peeled off from the outer surface of the endless metal strip 4c at the position Z without difficulty. In this way, the endless metal strip 4c having one surface with irregularities can be taken out via the roll 8.

  According to the manufacturing apparatus and manufacturing method of the present embodiment, the endless metal strip 4c is heated by electromagnetic induction heating using the electromagnetic induction heating apparatus 7, so that the endless metal exceeds the temperature necessary for transferring fine irregularities. The strip 4c can be heated quickly and reliably. In addition, since the low relative magnetic permeability layer 4b is located inside the endless metal strip 4c, generation of eddy current is made more efficient. Furthermore, a material with low relative permeability often has low thermal conductivity, and the heat of the endless metal strip 4c is difficult to be transmitted to the roll body 4a side to which the refrigerant is supplied. Accordingly, from the position X to the position Y, the endless metal strip 4c is reliably kept at a temperature suitable for transfer. Therefore, at the position X, fine irregularities can be transferred to the thermoplastic resin sheet 3 with high accuracy.

  In addition, in the region between the position X and the position Z, the temperature control roll 4 is cooled by the refrigerant. However, the temperature of the endless metal strip 4c gradually decreases, and at the position Z, fine unevenness is reduced. The thermoplastic resin sheet 3 in the direction can be easily peeled from the outer surface of the endless metal strip 4c.

  In the conventional thermoplastic resin sheet processing apparatus shown in FIG. 8, it has been attempted to increase the temperature of the thermoplastic resin sheet in advance by preheating. However, the heat given by the preheating is dissipated prior to the transfer, and the temperature at the time of transfer is not necessarily an appropriate temperature. Therefore, it was impossible to transfer fine irregularities with high accuracy. On the other hand, according to the present embodiment, as described above, fine irregularities can be transferred to the thermoplastic resin sheet 3 with high accuracy. In particular, unevenness having a high aspect ratio h / w1 of the convex portion 3a can be transferred with high accuracy according to this embodiment. Specifically, in the above-described conventional sheet processing apparatus 101, a convex portion having an aspect ratio of 0.5 or more could not be formed by a transfer method. Unevenness having convex portions 3a having h / w1 of 0.5 or more can be reliably transferred to one surface of the thermoplastic resin sheet 3.

  Moreover, when the unevenness | corrugation with the above large aspect ratios is formed in one surface, in order to peel the thermoplastic resin sheet 3 from the temperature control roll 4, it is necessary to cool to a certain low temperature. Otherwise, the shape of the concavo-convex structure having a large aspect ratio may be deformed upon peeling, or the thermoplastic resin sheet 3 may be distorted without being barren. In the present embodiment, since the endless metal strip 4c is appropriately cooled from the position X to the position Z, the temperature adjusting roll 4 can be comfortably even in the case of irregularities having convex portions having a large aspect ratio. Can be peeled off.

  Therefore, the uniformity of the obtained thermoplastic resin sheet can be improved, and the amount of distortion can be reduced. Therefore, for example, the thermoplastic resin sheet 3 can be suitably used as an optical film or sheet.

  FIG. 3 is a partially cutaway sectional view showing a louver sheet 3A as an example of such an optical sheet. In the louver sheet 3A, a light-shielding material layer 3b is filled between the convex portions 3a of the thermoplastic resin sheet 3. Since the thermoplastic resin sheet 3 itself is light-transmitting and the light-shielding material layer 3b is light-shielding, it is light-transmissive in the direction orthogonal to the surface direction of the thermoplastic resin sheet 3 as shown by an arrow B in FIG. As shown by an arrow C, light does not pass through the light-shielding material layer 3b at an angle inclined with respect to the surface of the thermoplastic resin sheet 3. Therefore, the louver sheet 3A can be used as the viewing angle control sheet.

  In addition to the louver sheet 3A and the prism sheet 11 shown in FIG. 4, the thermoplastic resin sheet obtained by the present invention can be suitably used for an optical sheet having various irregularities on one surface. Examples of such an optical sheet include a bench killer lens sheet, a Fresnel lens sheet, and a microlens array sheet. In addition, the present invention can provide a thermoplastic resin sheet having various fine irregularities on one surface, such as an embossed sheet provided on one surface, without being limited to an optical sheet.

  In the first embodiment, the unevenness having the plurality of convex portions 3a shown in FIG. 1C is formed, but the uneven shape formed on one surface of the thermoplastic resin sheet according to the present invention is particularly limited. Not. For example, as in the prism sheet 11 shown in FIG. 4, the surface may have a shape in which triangular convex portions having a width W and a height h are continuous on the surface in a cross section along the conveyance direction of the thermoplastic resin sheet 3. Here, the thickness t is the thickness of the sheet main body portion of the thermoplastic resin sheet 11 excluding the convex and concave portions. The aspect ratio in this case is defined by h / W, as described above.

(Second Embodiment)
FIG. 5 is a schematic configuration diagram showing a resin sheet manufacturing apparatus according to the second embodiment of the present invention. In the resin sheet manufacturing apparatus 1 of the present embodiment, the thermoplastic resin sheet 3 is supplied from the melt extrusion apparatus 2 between the temperature control roll 22 and the pressure roll 5. The melt extrusion apparatus 2 and the pressure roll 5 are configured in the same manner as in the first embodiment. Unlike the temperature control roll 4 of 1st Embodiment, the temperature control roll 22 is the same as the temperature control roll 4 of 1st Embodiment except not having the endless metal strip 4c in an outer peripheral surface. It is configured. Therefore, the description of the roll body and the low relative permeability layer is omitted by using the description of the first embodiment.

  A temperature control roll 23 is provided separately from the temperature control roll 22. An endless metal belt 24 as an endless metal strip is hung on the temperature control roll 23 and the temperature control roll 22. The endless metal belt 24 is made of the same material as the endless metal strip 4c used in the first embodiment. The endless metal belt 24 is configured separately from the temperature adjustment roll 22, and moves in the direction of the arrow D shown in the figure by rotationally driving the temperature adjustment roll 23. And the electromagnetic induction heating apparatus 7 is arrange | positioned in the conveyance direction upstream of the endless metal belt 24 rather than the position X, ie, the position where transfer to the thermoplastic resin sheet 3 is performed. Thus, the endless metal strip in the present invention may be an endless metal belt 24 that is a separate body of the temperature control roll 22.

  Also in the present embodiment, the roll 8 is arranged like the first embodiment, separated from the temperature control roll 22.

  Also in the manufacturing method using the resin sheet manufacturing apparatus 21 of the present embodiment, the endless metal belt 24 is heated at the position Y by the electromagnetic induction heating device 7 until the position X is reached, and the endless metal belt 24 is transferred. Heated above a sufficient temperature. Accordingly, at the position X, fine irregularities are reliably transferred to the thermoplastic resin sheet 3. After the transfer, similarly to the first embodiment, when the thermoplastic resin sheet 3 moves along the outer peripheral surface of the temperature control roll 22 appropriately, it is cooled to an appropriate temperature. Therefore, at the position Z, the thermoplastic resin sheet 3 having fine irregularities on one surface can be peeled off without difficulty.

  In this embodiment, the heat insulating material layer is integrated on the outer peripheral surface of the temperature control roll 22, but the low relative permeability layer is formed by coating the inner surface of the endless metal belt 24 with a low relative permeability material. It may be formed. Alternatively, a low relative permeability material may be provided on both the inner surface of the endless metal belt 24 and the outer peripheral surface of the temperature control roll 22. In this case, different low relative permeability materials may be used, or the same low relative permeability materials may be used.

  Furthermore, since the endless metal belt 24 is separate from the temperature control roll 22, in order to suppress wear of the inner peripheral surface of the endless metal belt 24 due to friction, rubbing or cutting of the endless metal belt 24, etc. An inorganic material layer that achieves such an effect may be formed. Accordingly, it is possible to prevent foreign matters from being mixed into the resin sheet.

  The frequency of the high-frequency current used for electromagnetic induction heating is not particularly limited, but a range of 10 kHz to 1 MHz is preferable. If the frequency is too high, the permeability of the endless metal strip 4c will be low, and it will be difficult to efficiently heat it. If it is too low, the electromagnetic field may be disturbed in the endless metal strip 4c, the magnetic field may leak to the outside, and efficient heating may not be performed.

  In FIG. 5, the endless metal belt 24 is hung between the temperature control roll 23 and the temperature control roll 22, but a roll having the same structure as the temperature control roll 22 may be used as the temperature control roll 23. . Thus, by arranging a plurality of temperature control rolls inside the endless metal belt 24, the temperature control of the endless metal belt 24 can be performed more finely. For example, when a crystalline thermoplastic resin such as polypropylene is formed into a sheet, the crystallization rate can be easily controlled by using a plurality of temperature adjusting rolls. Therefore, it is possible to provide a thermoplastic resin sheet with better quality.

  The control temperature of the temperature control roll 23 may be the same as or different from the temperature control roll 22, and the configuration of the temperature control roll 23 may be the same as or different from the temperature control roll 22.

  However, when the temperature adjusting roll 23 is the same as the temperature adjusting roll 22, adjustment of molding conditions, for example, temperature adjustment can be performed more reliably and promptly. In addition, preparation and maintenance of the manufacturing apparatus are facilitated.

  Further, in addition to the temperature control rolls 22 and 23, a temperature control roll may be further provided on the downstream side of the electromagnetic induction heating device 7 and on the upstream side of the position X. In that case, the temperature control roll on the upstream side may be provided. The transferability can be further enhanced by relatively increasing the temperature of the film.

  When the temperature adjusting rolls 22 and 23 are used, the tension of the endless metal belt 24 can be adjusted by controlling the position of the temperature adjusting roll 23. Thereby, meandering of the endless metal belt 24 can be prevented, and the degree of heat transfer between the temperature control rolls 22 and 23 can be adjusted.

(Third embodiment)
FIG. 6 is a schematic configuration diagram showing a resin sheet manufacturing apparatus according to the third embodiment of the present invention. In the resin sheet manufacturing apparatus 31 of the present embodiment, the temperature adjustment roll 4 configured in the same manner as in the first embodiment is used. The difference from the first embodiment is that the edge of the thermoplastic resin sheet 3 extruded from the melt extrusion device 2 is in contact with the outer peripheral surface of the endless metal strip provided on the outer peripheral surface of the temperature control roll 4. The pinning device 32 causes the thermoplastic resin sheet 3 to be in close contact with the outer surface of the endless metal strip 4c. The edge pinning device 32 can be formed using a known edge pinning device. According to edge pinning, a thermoplastic resin sheet having a small residual phase difference, a small flare, and an excellent thickness accuracy can be obtained.

  Also in this embodiment, since the endless metal strip 4c is preheated to a temperature suitable for transfer by the electromagnetic induction heating device 7, the endless thermoplastic resin sheet 3 is endless by the edge pinning device 32 as a device for imparting irregularities. When brought into close contact with the metal strip, fine irregularities can be reliably and accurately transferred. When the edge pinning device 32 is used, the pressure-bonding roll 5 in the first embodiment can be omitted.

  Further, instead of the edge pinning device, a die roll method or an air knife method in which the resin extruded from the die lip is directly pressed against the endless metal strip may be used as a device for providing irregularities on one surface of the thermoplastic resin sheet 3. As an apparatus using such a die roll method or an air knife method, a known apparatus can be appropriately used.

  As a modification of the first embodiment, as shown in FIG. 7, the endless metal strip 4 c may be formed of an endless metal belt 24 </ b> A that is separate from the temperature control roll 4. That is, in the present invention, the endless metal strip is not necessarily integrated with the temperature control roll 4.

[Examples and Comparative Examples]
Hereinafter, specific examples and comparative examples of the present invention will be given to clarify the effects of the present invention.

Example 1
The thermoplastic resin sheet 3 shown in FIG.1 (c) was obtained using the resin sheet manufacturing apparatus 1 of the first embodiment. W1, W2, h, and t shown in FIG. 1C were set to W1 = 20 μm, W2 = 53 μm, h = 100 μm, and t = 300 μm, respectively. As the thermoplastic resin used, Asahi Kasei Co., Ltd., acrylic resin, trade name: Delpet was used.

  The conditions were set so that the surface temperature of the endless metal strip at position X was 160 ° C.

(Example 2)
A thermoplastic resin sheet was obtained in the same manner as in Example 1 except that the uneven shape was changed. That is, W1 = 20 μm, W2 = 53 μm, h = 50 μm, t = 300 μm.

(Example 3)
A thermoplastic resin sheet 11 was obtained in the same manner as in Example 2 except that the shape of the irregularities on the surface of the endless metal strip was changed so as to obtain the thermoplastic resin sheet 11 shown in FIG. The dimensions in FIG. 4 were as follows.

W = 50 μm, h = 25 μm, t = 300 μm
(Comparative Example 1)
A thermoplastic resin sheet similar to that of Example 2 was produced using the conventional processing apparatus 101 shown in FIG. As the temperature at the transfer position increased, the thermoplastic resin sheet peeled off from the roll, so the roll temperature at the transfer position was 130 ° C., which is a moldable temperature.

(Comparative Example 2)
Using the processing apparatus 101 shown in FIG. 8, an attempt was made to produce a thermoplastic resin sheet 11 having the same irregularities as in Example 3. As the temperature at the transfer position became higher, peeling of the thermoplastic resin sheet near the roll occurred, so the temperature at the transfer position was set to 130 ° C., which is a moldable temperature.

(Evaluation)
The unevenness transferability of each thermoplastic resin sheet obtained in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated. The uneven portion was cut in a direction perpendicular to the sheet surface direction, photographed with a microscope, and the transfer rate and the radius of curvature R of the convex portion corner were determined. The results are shown in Table 1 below.

  The transfer rate in Table 1 means the ratio of the height of the unevenness formed on the endless metal strip to the height of the unevenness transferred to the thermoplastic resin sheet. That is, the ratio of the height of the convex portion of the endless metal strip to the height h shown in FIG. Moreover, the corner | angular part R of Table 1 is an average value of the curvature radius of the corner part of the both sides of the front-end | tip of the convex part in the said cross section.

  The inability to measure the corner R in Table 1 means that the corner is not rounded.

  In Examples 1 to 3, the shape of the unevenness of the endless metal strip was completely transferred to one surface of the thermoplastic resin sheet 3, and no roundness was observed even at the corners. In contrast, in Comparative Example 1, the corners were rounded. In Comparative Example 2, the transfer rate was as low as 95%, and the corners were rounded.

DESCRIPTION OF SYMBOLS 1 ... Resin sheet manufacturing apparatus 2 ... Melt extrusion apparatus 3 ... Thermoplastic resin sheet 3A ... Louver sheet 3a ... Convex part 3b ... Light-shielding material layer 3c ... Endless metal strip 4 ... Temperature control roll 4a ... Roll main body 4b ... Low ratio Permeability layer 4c ... endless metal strip 4d ... convex part 5 ... pressure roll 7 ... electromagnetic induction heating device 8 ... roll 11 ... thermoplastic resin sheet 13 ... roll 21 ... resin sheet manufacturing apparatus 22, 23 ... temperature control roll 24 ... Endless metal belt 24A ... Endless metal belt 31 ... Production equipment 32 ... Edge pinning equipment

Claims (11)

An apparatus for producing a resin sheet having irregularities formed on one side,
A temperature control roll having a roll body made of metal;
A first driving device for rotationally driving the temperature control roll;
An endless metal strip in which irregularities having a shape corresponding to the irregularities formed on the surface of the resin sheet are formed on the outer surface;
A material having a lower relative permeability than the endless metal strip is provided on at least one of the outer peripheral surface of the temperature control roll and the inner peripheral surface of the endless metal strip,
The resin sheet is brought into contact with the outer peripheral surface of the endless metal strip while rotating the temperature control roll while the endless metal strip is in contact with the temperature control roll through the low relative permeability material. A device for providing irregularities on one surface of the resin sheet;
An apparatus for producing a resin sheet, comprising: an electromagnetic induction heating device for heating the endless metal strip upstream of a position where the resin sheet is in contact with an outer peripheral surface of the endless metal strip.   The apparatus for producing a resin sheet according to claim 1, wherein the low relative permeability material is integrally formed on an outer peripheral surface of the roll body of the temperature control roll.   The endless metal strip is integrally provided on the outer peripheral surface of the low relative permeability material, whereby the heat insulating material and the endless metal strip are integrated with the roll body. The manufacturing apparatus of the resin sheet of description.   The endless metal strip is an endless metal belt, the temperature control roll has a plurality of temperature control rolls, and the endless metal belt is stretched over a plurality of temperature control rolls. Resin sheet manufacturing equipment.   An apparatus for providing irregularities on one surface of the resin sheet has a pressure roll that presses the resin sheet and the outer peripheral surface of the endless metal strip, and the pressure roll has a gap between the temperature control roll. The apparatus for producing a resin sheet according to any one of claims 1 to 3, wherein the resin sheet is arranged and the resin sheet is crimped to a crimping roll on the outer surface side of the metal strip in the gap.   The apparatus for producing a resin sheet according to any one of claims 1 to 3, wherein the apparatus for imparting irregularities to one surface of the resin sheet is an edge pinning apparatus.   The apparatus for producing a resin sheet according to any one of claims 1 to 3, wherein the apparatus for imparting irregularities to one surface of the resin sheet is an air knife.   The apparatus according to any one of claims 1 to 7, further comprising a melt extrusion device for extruding the molten resin into a sheet shape, wherein unevenness is imparted to one surface of the flat resin sheet extruded by the melt extrusion device. The manufacturing apparatus of the resin sheet of description.   The resin according to any one of claims 1 to 8, wherein the temperature control roll has a hollow portion inside a roll body made of metal, and further includes a refrigerant supply device for supplying a refrigerant to the hollow portion. Sheet manufacturing equipment.   The apparatus for producing a resin sheet according to any one of claims 1 to 9, wherein an aspect ratio of a cross section of the convex portion is 0.5 or more in the unevenness of the outer surface of the endless metal strip. A method for producing a resin sheet using the resin sheet producing apparatus according to any one of claims 1 to 10, wherein unevenness is formed on one surface,
Driving the endless metal strip and the temperature control roll with a driving device;
Heating the endless metal strip with the electromagnetic induction heating device;
At least a part of the endless metal strip in the transport direction on the downstream side in the transport direction of the endless metal strip from the position heated by the electromagnetic induction heating device of the endless metal strip transported by the driving device The endless metal strip is brought into contact with the temperature control roll through the heat insulating material, and the one surface of the resin sheet is connected to the endless metal in at least a part of the transport direction of the endless metal strip. Contacting the outer peripheral surface of the belt-like body, and providing irregularities on one surface of the resin sheet;
Peeling the resin sheet provided with the irregularities from the endless metal strip on the outer peripheral surface of the temperature control roll.

Images