JP2006297910A - Manufacturing method of resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin sheet which can obtain a desired cross-section in manufacturing the resin sheet large in a thickness distribution in a width direction in the formation, and particularly, is suitable for using for various kinds of optical elements and a light guide plate arranged on a back face of various kinds of displays. <P>SOLUTION: A first sheet-like resin material 14 extruded by a first die 12, and a second sheet-like resin material 17 extruded by a second die 15 are laminated, and pinched with a mold roller and a nip roller such that the first resin material contacts the mold roller 16, and the second resin material contacts the nip roller 18. An irregularity form of a mold roller surface is transcribed to the first resin material, and at the same time, the first resin material and the second resin material are brought into close contact. The first and the second resin materials in close contact are peeled off from the mold roller by the winding with a separated roller arranged opposite the mold roller. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a resin sheet, and more particularly to a method for producing a resin sheet suitable for use in a light guide plate and various optical elements disposed on the back surface of various display devices.

  As resin sheets used for various optical elements, Fresnel lenses, lenticular lenses, and the like are used in various fields. A regular uneven shape is formed on the surface of such a resin sheet, and this uneven shape exhibits optical performance as a Fresnel lens or a lenticular lens.

  As a method for producing such a resin sheet, various proposals have been made so far (see Patent Documents 1 to 4). In these proposals, the roller molding method is adopted from the viewpoint of improving productivity.

  For example, Patent Document 1 attempts to improve transferability by devising the cooling means until the resin sheet is peeled from the roller. Patent Document 2 discloses a method of manufacturing a Fresnel lens by winding a die around a roller.

  In Patent Document 3, a heat buffer member is arranged inside the forming roller to improve productivity and transferability. Patent Document 4 uses a corona discharge treatment to improve transferability and reduce defects.

  A typical roller forming system of these prior arts has a configuration shown in FIG. This apparatus configuration includes a sheet die 2 for shaping a resin material 1 melted by an extruder (not shown) into a sheet shape, a stamper roller 3 having an uneven surface formed thereon, and a stamper roller 3. And a mirror roller 4 for peeling, which is disposed opposite to the mirror roller 4 while facing the stamper roller 3.

Then, the sheet-like resin material 1 extruded from the die 2 is pressed between the stamper roller 3 and the mirror roller 4, and the uneven shape on the surface of the stamper roller 3 is transferred to the resin material 1, and the resin material 1 is peeled off by the mirror roller for peeling. 5 is peeled off from the stamper roller 3 by being wound around.
JP-A-8-31025 JP-A-7-314567 JP 2003-53834 A JP-A-8-287530

  However, any of the above conventional proposals relates to a method for producing a relatively thin resin sheet, and is not suitable for producing a relatively thick resin sheet. In particular, when a resin sheet having a large thickness distribution in the width direction during molding is produced, it is very difficult to obtain a desired cross-sectional shape.

  For example, when PMMA (polymethylmethacrylate resin) is extruded and then subjected to roller molding, when the thickness distribution is given in the width direction and the difference in thickness between the thickest part and the thinnest part is 1 mm or more, the surface or There are various problems such as unevenness on the back surface (shrinkage due to shrinkage when the resin is cured, distribution of elastic recovery amount), overall surface shape transfer rate is reduced, and sharp edge shape cannot be transferred.

  The present invention has been made in view of such circumstances. When a resin sheet having a large thickness distribution in the width direction at the time of molding is produced, a desired cross-sectional shape can be obtained. It aims at providing the manufacturing method of the resin sheet suitable for using for the light-guide plate and various optical elements which are distribute | arranged to a back surface.

  In order to achieve the above object, the present invention laminates a sheet-like first resin material extruded from a first die and a sheet-like second resin material extruded from a second die, The mold roller and the nip roller disposed opposite to the mold roller are pressed so that the first resin material contacts the mold roller and the second resin material contacts the nip roller. A peeling roller that transfers the first resin material and the second resin material in close contact with each other, and the first and second resin materials after contact are disposed opposite to the mold roller. A method for producing a resin sheet is provided, wherein the resin sheet is separated from the mold roller by being wound around.

  According to the present invention, the first resin material and the second resin material are laminated, pressed between the mold roller and the nip roller, and the uneven shape on the surface of the mold roller is transferred to the first resin material. The resin material and the second resin material are brought into close contact with each other, and the laminated body after the close contact is wound around the release roller to be peeled off from the mold roller. In this way, by laminating two types of resin materials, even if the resin sheet has a large thickness distribution in the width direction during molding, the back surface unevenness that occurs immediately after molding is less likely to occur, and a desired cross-sectional shape is obtained. be able to.

  In the present invention, a configuration in which the first resin material extruded from the first die and the second resin material extruded from the second die are stacked is adopted, but a configuration in which two dies are provided. Instead, it can be said that a structure using a multi-manifold die or a feed block type die is also within the equivalent scope of the invention according to claim 1. That is, even with these configurations, an equivalent action can be achieved, and an equivalent effect can be obtained.

  In the present invention, it is preferable that an uneven shape is formed on the surface of the nip roller and / or the peeling roller. Thus, if the uneven | corrugated shape is formed in the surface of a nip roller and / or a peeling roller, the resin sheet in which the uneven | corrugated shape was formed in both front and back is obtained.

  In this case, for example, an uneven shape having a large thickness distribution in the width direction is formed on the first resin material by the mold roller, and an uneven shape having a smaller thickness distribution in the width direction is formed by the nip roller and / or the peeling roller. A desired cross-sectional shape can be obtained on the front and back surfaces by forming the two resin materials and laminating them. For example, a lenticular lens is formed on the front surface side, and an uneven shape with a fine pitch of one digit or more is formed on the back surface side to form a scattering surface.

In the present invention, it is preferable that the glass transition temperature Tg _{1 of the first} resin material is lower than the glass transition temperature Tg ₂ of the second resin material. As described above, when the glass transition temperature Tg ₁ of the first resin material is lower than the glass transition temperature Tg _{2 of the second} resin material, an uneven shape having a large thickness distribution in the width direction of the first resin material is obtained. It is suitable for forming an uneven shape having a smaller thickness distribution in the width direction of the second resin material.

  The “glass transition temperature Tg” refers to a temperature at which the organic polymer substance moves from a low temperature glass state to a high temperature supercooled liquid or rubber.

  In the present invention, due to the concavo-convex shape transferred to the first and / or the second resin material, the thickest portion and the thinnest portion in the width direction of the laminate of the first and second resin materials The difference in thickness is preferably 1 mm or more. Moreover, in this invention, it is preferable that the thickness of the thinnest part of the laminated body of the said 1st and 2nd resin material is 5 mm or less. Thus, the effect of the present invention can be exhibited in the molding of a resin material having a cross-sectional shape that has been difficult to mold.

  As described above, according to the present invention, a desired cross-sectional shape can be obtained even with a resin sheet having a large thickness distribution in the width direction during molding.

  Hereinafter, preferred embodiments of a method for producing a resin sheet according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing an example of a resin sheet production line to which a resin sheet production method according to the present invention is applied.

  The resin sheet production line 10 is melted by an extruder 13 and a die 12 which is a first die for a sheet for shaping the first resin material 14 melted by the extruder 11 into a sheet shape. Furthermore, the die 15 which is the second die for the sheet for shaping the second resin material 17 into a sheet shape, the die roller 16 having a concavo-convex shape formed on the surface, and the die roller 16 are arranged opposite to each other. A nip roller 18, a peeling roller 24 disposed opposite to the mold roller 16, a plurality of guide rollers 22, 22,... That support the conveyance of the laminated body 32 of the first resin material 14 and the second resin material 17. Consists of.

  The slit size of the die 12 is formed such that the width of the molded first resin material 14 in the molten state is wider than the width of the mold of the mold roller 16, and the melted first resin material 14 is extruded from the die 12. One resin material 14 is arranged to be extruded between the mold roller 16 and the nip roller 18.

  Similarly, the slit size of the die 15 is formed such that the width of the molded second resin material 17 in the molten state is wider than the width of the mold of the mold roller 16, and the melt extruded from the die 15. The second resin material 17 in a state is disposed so as to be pushed out between the mold roller 16 and the nip roller 18.

  A regular uneven shape is formed on the surface of the mold roller 16. This regular uneven | corrugated shape can be made into the inversion shape of the 1st resin material 14 after the shaping | molding shown by FIG. 2, for example. FIG. 2 is a perspective view of a state in which the end surface 14A of the first resin material 14 (laminated body 32) after molding is cut out on a straight line.

  On the other hand, the surface of the nip roller 18 is flat and smooth. In the present embodiment, the surface of the nip roller 18 is flattened, but it may be a regular uneven shape like the mold roller 16.

  That is, the back surface of the laminated body 32 (second resin material 17) is a flat surface, and a linear uneven pattern parallel to the arrow is formed on the surface of the first resin material 14. This arrow indicates the traveling direction of the first resin material 14. Therefore, an endless groove having an inverted shape of the end face 14 </ b> A may be formed on the surface of the mold roller 16. In addition, the detail of the uneven | corrugated pattern shape on the surface of the 1st resin material 14 is mentioned later.

  The material of the mold roller 16 includes various steel members, stainless steel, copper, zinc, brass, and a metal lining of these metal materials, and a rubber lining on the surface. These metal materials are HCr plated, Cu plated, Ni plated. For example, ceramics and various composite materials can be used.

  The method for forming the concavo-convex pattern on the surface of the mold roller 16 depends on the concavo-convex pattern (pitch, depth, etc.) and the material of the surface of the mold roller 16, but generally a combination of cutting with an NC lathe and finishing buffing. Can be preferably employed. In addition, other known processing methods (grinding processing, ultrasonic processing, electric discharge processing, etc.) can also be employed.

  When forming a regular uneven shape on the surface of the nip roller 18, a similar forming method can be employed. On the other hand, when the surface of the nip roller 18 is formed flat and smooth as in the present embodiment, generally, a combination of cutting with a lathe and finish buffing can be preferably employed.

  The surface roughness of the surface of the mold roller 16 is preferably 0.5 μm or less in Ra, and more preferably 0.2 μm or less.

  The mold roller 16 is driven to rotate in a direction indicated by an arrow in FIG. 1 at a predetermined peripheral speed by a driving means (not shown). The mold roller 16 is provided with temperature adjusting means. By providing such a temperature adjusting means, it is possible to control to suppress a temperature rise or a sudden temperature drop of the mold roller 16 due to the first resin material 14 (laminated body 32) in a high temperature state.

  As such temperature adjusting means, a configuration in which oil whose temperature is adjusted is circulated inside the roller can be preferably employed. This supply and discharge of oil can be realized by a configuration in which a rotary joint is provided at the end of the roller. In the resin sheet production line 10 of FIG. 1, this temperature adjusting means is employed.

  The nip roller 18 is disposed opposite to the mold roller 16 and is a roller for sandwiching the laminated body 32 of the first resin material 14 and the second resin material 17 laminated on the back surface by the mold roller 16. It is arranged at the same height as the mold roller 16 on the upstream side in the direction.

  When the back surface of the laminate 32 is formed flat, as described above, the surface of the nip roller 18 is preferably processed into a mirror surface. By setting it as such a surface, the back surface of the 2nd resin material 17 (laminated body 32) after shaping | molding can be made into a favorable state. The surface roughness of the surface of the nip roller 18 is preferably 0.5 μm or less in Ra, and more preferably 0.2 μm or less.

  The material of the nip roller 18 includes various steel members, stainless steel, copper, zinc, brass, and a metal lining of these metal materials, and a rubber lining on the surface. These metal materials are HCr plated, Cu plated, Ni plated, etc. These materials, ceramics, and various composite materials can be used.

  The nip roller 18 is rotationally driven in a direction indicated by an arrow in FIG. 1 at a predetermined peripheral speed by a driving means (not shown). In addition, although the structure which does not provide a drive means in the nip roller 18 is also possible, it is preferable to provide a drive means from the point which can make the surface (back surface of the laminated body 32) of the 2nd resin material 17 a favorable state.

  The nip roller 18 is provided with a pressing means (not shown) so that the laminated body 32 between the nip roller 18 and the mold roller 16 can be pressed with a predetermined pressure. The pressurizing means is configured to apply pressure in the normal direction at the contact point between the nip roller 18 and the mold roller 16, and various known means such as a motor driving means, an air cylinder, and a hydraulic cylinder can be employed.

  The nip roller 18 may be configured to be less likely to bend due to the reaction force of the clamping pressure. As such a configuration, a configuration in which a backup roller is provided on the back side of the nip roller 18 (opposite side of the mold roller 16), a configuration in which a crown shape (middle and high shape) is adopted, and a rigidity in the central portion in the axial direction of the roller is large. A configuration of a roller having such an intensity distribution, a configuration combining these, and the like can be employed.

  The nip roller 18 is provided with temperature adjusting means. The set temperature of the nip roller 18 includes the material of the second resin material 17, the temperature when the second resin material 17 is melted (for example, the slit exit of the die 15), and the second resin material 17 (laminated body 32). The optimum value should be selected according to the conveying speed, the outer diameter of the mold roller 16, the uneven pattern shape of the mold roller 16, and the like.

  As the roller temperature adjusting means of the nip roller 18, a configuration in which oil whose temperature is adjusted is circulated inside the roller can be preferably employed. This supply and discharge of oil can be realized by a configuration in which a rotary joint is provided at the end of the roller. In the resin sheet production line 10 of FIG. 1, this temperature adjusting means is employed.

  As other temperature adjusting means, for example, various known means such as a structure in which a sheath heater is embedded in the roller and a structure in which a dielectric heating means is disposed in the vicinity of the roller can be adopted.

As described above, the glass transition temperature Tg ₁ of the first resin material 14 is preferably lower than the glass transition temperature Tg ₂ of the second resin material 17. As described above, if the thermal deformation of the first resin material 14 is larger than that of the second resin material 17, the uneven shape of the surface of the first resin material 14 can be increased, and the surface of the second resin material 17 can be increased. Convenient for flattening.

  In addition, the measurement of the glass transition temperature Tg of the resin material is a measurement of a calorie change by differential scanning calorimetry (DSC), a measurement of tan δ = G ″ (loss elastic modulus) / G ′ (storage elastic modulus) by a rheometer, etc. Can be by general methods.

  In addition, unlike the present embodiment, when the uneven shape is formed on the surface of the second resin material 17, the thermal deformation of the first resin material 14 is larger than that of the second resin material 17 in this way. The uneven shape on the surface of the first resin material 14 can be increased, and the uneven shape on the surface of the second resin material 17 can be favorably formed.

  It is preferable to provide surface temperature measuring means (not shown) so that the surface temperatures of the respective rollers, the first resin material 14 and the second resin material 17 described above can be monitored. As such surface temperature measuring means, various known measuring means such as an infrared thermometer and a radiation thermometer can be employed.

  Examples of measurement points by such surface temperature measuring means include, for example, a plurality of points in the width direction of the first resin material 14 between the die 12 and the mold roller 16, and the first resin material 14 immediately after the peeling roller 24. A plurality of points in the width direction, and surfaces of a plurality of points in the width direction of the first first resin material 14 wound around the mold roller 16 and the peeling roller 24 are conceivable.

  Further, the monitoring result of the surface temperature measuring means can be fed back to the temperature adjusting means of each roller, the die 12, the die 15, etc. and reflected in the temperature control of each roller. It is also possible to operate by feedforward control without providing the surface temperature measuring means.

  A tension detecting means for detecting the tension of the laminated body 32 or a plate thickness detecting means (thickness sensor) for detecting the thickness of the laminated body 32 is provided on the resin sheet production line 10 in FIG. It can also be preferably adopted.

  The slow cooling zone 30 (or annealing zone) is provided to prevent a rapid temperature change of the laminate 32 downstream of the peeling roller 24. When a rapid temperature change occurs in the laminated body 32, for example, although the vicinity of the surface of the laminated body 32 is in an elastic state, the inside of the laminated body 32 is in a plastic state. The surface shape of the body 32 deteriorates. Further, there is a problem that a temperature difference is generated between the first resin material 14 and the second resin material 17 (front and back surfaces), and the laminate 32 is warped.

  As the slow cooling zone 30, a configuration in which a horizontal tunnel shape is provided, temperature adjusting means is provided inside the tunnel, and the cooling temperature profile of the stacked body 32 can be controlled. As temperature adjusting means, a structure in which air (hot air or cold air) whose temperature is controlled from a plurality of nozzles is jetted toward the laminated body 32, and heating means (nichrome wire heater, infrared heater, dielectric heating means, etc.) are laminated. Various known means such as a structure for heating the front and back surfaces of the body 32 can be adopted.

  Downstream of the slow cooling zone 30, a cleaning device (cleaning zone), a defect inspection device (inspection zone), a laminating device, a side cutter, a cross cutter, and a stacking unit are sequentially provided for the laminate 32 (all illustrated). Abbreviation).

  Among these, the laminating apparatus is an apparatus that attaches a protective film (film such as polyethylene) to the front and back surfaces of the laminate 32, and the side cutter is an apparatus that excises both end portions (discarded portions) in the width direction of the laminate 32. The cross cutter is a device that cuts the laminated body 32 to a predetermined length.

  Some of the above devices may be omitted depending on the application.

  Next, a method for producing a resin sheet by the resin sheet production line 10 shown in FIG. 1 will be described.

  As the first resin material 14 and the second resin material 17 applied to the present invention, a thermoplastic resin can be used. For example, polymethyl methacrylate resin (PMMA), polycarbonate resin, polystyrene resin, MS resin, An AS resin, a polypropylene resin, a polyethylene resin, a polyethylene terephthalate resin, a polyvinyl chloride resin (PVC), a thermoplastic elastomer, a copolymer thereof, a cycloolefin polymer, or the like can be given.

  A sheet-shaped first resin material 14 extruded from the die 12 and a sheet-shaped second resin material 17 extruded from the die 15 are laminated, and a mold roller 16 and a nip roller 18 disposed to face the mold roller 16. The surface of the mold roller 16 is transferred to the first resin material 14, and the surface of the second resin material 17 is maintained flat and smooth by the nip roller 18. The laminate with the resin material 17 is wound around a peeling roller 24 disposed opposite to the mold roller 16 to be peeled off from the mold roller 16.

  The laminated body 32 of the first resin material 14 and the second resin material 17 peeled off from the mold roller 16 is transported in the horizontal direction and gradually cooled by passing through the slow cooling zone 30, and the distortion is removed. In this state, the product is cut into a predetermined length at the downstream product take-up portion and accommodated as a resin sheet product.

  In the production of the resin sheet 14, the extrusion speed of the first resin material 14 from the die 12 and the extrusion speed of the second resin material 17 from the die 15 are 0.1 to 50 m / min, preferably 0. A value of 3 to 30 m / min can be employed. Therefore, the peripheral speed of the mold roller 16, the peripheral speed of the nip roller 18, and the peripheral speed of the peeling roller 24 are also substantially matched to this.

  It should be noted that the speed unevenness of each roller is preferably controlled to be within 1% of the set value.

  The pressing pressure of the nip roller 18 against the mold roller 16 is 0 to 200 kN / m (0 to 200 kgf / cm) in terms of linear pressure (value converted assuming that the surface contact due to elastic deformation of each nip roller is linear contact). It is preferable to set it to 0 to 100 kN / m (0 to 100 kgf / cm).

  The temperature control of the nip roller 18 and the peeling roller 24 is preferably performed for each individual roller. And it is preferable that the 1st resin material 14 in the location of the peeling roller 24 is the temperature below the softening point Ta of resin. At this time, when a polymethyl methacrylate resin is employed for the first resin material 14, the set temperature of the peeling roller 24 can be 50 to 110 ° C.

  Next, details of the uneven pattern shape on the surface of the first resin material 14 will be described. As described above, FIG. 2 is a perspective view of a state in which the end surface 14A of the first resin material 14 (laminated body 32) after molding is cut out on a straight line. The back surface of the laminate 32 (the surface of the second resin material 17) is a flat surface.

  The concavo-convex pattern shape on the surface of the multilayer body 32 (first resin material 14) is a linear concavo-convex pattern in the longitudinal direction (arrow direction in the figure). This pattern is linearly formed from the V-groove 50 formed in the thickest portion 14B of the first resin material 14 and the thinnest portion 14C of the first resin material 14 from both edges of the V-groove 50. The taper portions 52, 52 with decreasing plate thickness are repeated. That is, it is a continuous shape in which the V groove 50 and the taper portions 52 and 52 on both sides, which are line targets with respect to the center line of the V groove 50, are one unit (one pitch).

  In FIG. 2, the thickness of the thinnest portion 14C (or the laminate 32) of the first resin material 14 is preferably 5 mm or less, and more preferably 0.5 mm or more and 2 mm or less. The difference in thickness between the thickest part 14B and the thinnest part 14C of the first resin material 14 is preferably 1 mm or more, and more preferably 2.5 mm or more. By setting it as such a dimension, it can be used conveniently for the light-guide plate and various optical elements which are distribute | arranged to the back surface of various display apparatuses.

  When the molded laminate 32 is used as a light guide plate, a cylindrical cold cathode tube is arranged inside the V groove 50, and the light irradiated from the cold cathode tube is laminated from the surface of the V groove 50. The light enters the inside of the body 32, is reflected by the tapered portions 52 and 52, and is irradiated in a planar shape from the back surface of the stacked body 32.

  Thus, when using the laminated body 32 after shaping | molding for a light-guide plate, it is preferable to make the width | variety p of V-groove 50 into 2 mm or more, and to make apex angle (theta) 1 of V-groove 50 into 40-80 degree | times. preferable. The depth Δt of the V groove 50 is preferably 1 mm or more, and more preferably 2.5 mm or more. The inclination angle θ2 of the tapered portions 52, 52 is preferably 3 to 20 degrees. Further, the width p2 of the tapered portions 52, 52 is preferably 5 mm or more, and more preferably 10 mm or more.

  Next, the other uneven | corrugated pattern shape of the laminated body 32 surface is demonstrated. FIG. 3 is a perspective view of a state in which the end surface 14A of the first resin material 14 (laminated body 32) after molding is cut out on a straight line. The back surface of the laminate 32 (the surface of the second resin material 17) is a flat surface.

  The uneven pattern shape on the surface of the first resin material 14 (laminated body 32) is a linear uneven pattern in the longitudinal direction (the arrow direction in the figure). This cross-sectionally saw-tooth pattern has a vertical wall 54 connecting the thickest wall portion 14B and the thinnest wall portion 14C of the first resin material 14 and the upper edge (thickest wall portion 14B) of the vertical wall 54. The taper portion 56 in which the plate thickness decreases linearly toward the thinnest portion 14C of one resin material 14 is repeated.

  In FIG. 3, the thickness of the thinnest portion 14C (or the laminate 32) of the first resin material 14 is preferably 5 mm or less, and more preferably 0.5 mm or more and 2 mm or less. The difference in thickness between the thickest part 14B and the thinnest part 14C of the first resin material 14 is preferably 1 mm or more, and more preferably 2.5 mm or more. By setting it as such a dimension, it can be used conveniently for the light-guide plate and various optical elements which are distribute | arranged to the back surface of various display apparatuses.

  When the molded laminate 32 is used as a light guide plate, a cylindrical cold cathode tube is disposed on the side surface of the vertical wall 54, and light rays irradiated from the cold cathode tube are irradiated on the surface (side surface) of the vertical wall 54. ) Is incident on the inside of the laminated body 32, is reflected by the taper portion 56, and is irradiated in a planar shape from the back surface of the laminated body 32.

  Thus, when using the laminated body 32 after shaping | molding for a light-guide plate, it is preferable that the taper part 56 inclination-angle (theta) 3 shall be 3-20 degree | times.

  In addition, when using the laminated body 32 after a shaping | molding for a light-guide plate, shapes other than these can also be employ | adopted. For example, the cross-sectional shape of the V groove 50 of the first resin material 14 in FIG. 2 is V-shaped, but other shapes such as a rectangular shape, a trapezoidal shape, an arc shape, a parabolic shape, etc. However, it can be employed if optical characteristics, moldability, and the like are satisfied.

  Further, the uneven shape on the surface of the mold roller 16 does not have to be the inverted shape of the surface of the first resin material 14 in FIG. 2 or 3. It can also be set as the shape offset from this shape so that the product shape of 32 may become the shape of FIG. 2 or FIG.

  According to the manufacturing method of the resin sheet which concerns on this invention demonstrated above, even if it is a resin sheet with a large thickness distribution of the width direction at the time of shaping | molding, a desired cross-sectional shape can be obtained.

  As mentioned above, although embodiment of the manufacturing method of the resin sheet which concerns on this invention was described, this invention is not limited to the said embodiment, Various aspects can be taken.

  For example, the number and arrangement of the nip rollers may take various aspects other than the present embodiment as long as the same function can be obtained.

  Moreover, as long as the slow cooling zone 30 etc. can obtain the same function, various aspects other than this embodiment can be taken.

The block diagram which shows the example of the production line of the resin sheet to which this invention is applied The perspective view of the state which cut off the end face of the resin material after molding on a straight line The perspective view of the state which cut off the end face of the resin material after molding on a straight line Configuration diagram showing production line of resin sheet of conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Resin sheet production line, 12 ... Die (first die), 14 ... First resin material, 15 ... Die (second die), 16 ... Mold roller, 17 ... Second resin material, 18 ... Nip roller, 22 ... Guide roller, 24 ... Peeling roller, 30 ... Slow cooling zone, 32 ... Laminate

Claims (5)

A sheet-like first resin material extruded from the first die and a sheet-like second resin material extruded from the second die are laminated,
Clamping is performed between the mold roller and the nip roller disposed opposite to the mold roller so that the first resin material contacts the mold roller and the second resin material contacts the nip roller,
The uneven shape on the surface of the mold roller is transferred to the first resin material, and the first resin material and the second resin material are brought into close contact with each other,
A method for producing a resin sheet, characterized in that the first and second resin materials after contact are wound on a peeling roller disposed opposite to the mold roller to be peeled off from the mold roller.   The method for producing a resin sheet according to claim 1, wherein an uneven shape is formed on a surface of the nip roller and / or the peeling roller. 3. The method for producing a resin sheet according to claim ₁ , wherein the glass transition temperature Tg _{1 of the first} resin material is lower than the glass transition temperature Tg ₂ of the second resin material.   Due to the uneven shape transferred to the first and / or second resin material, the difference in thickness between the thickest and thinnest portions in the width direction of the laminate of the first and second resin materials The method for producing a resin sheet according to any one of claims 1 to 3, wherein the thickness is 1 mm or more. The method for producing a resin sheet according to any one of claims 1 to 4, wherein the thickness of the thinnest portion of the laminate of the first and second resin materials is 5 mm or less.

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