JP4552716B2 - Manufacturing method of resin sheet - Google Patents

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.
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 provides a sheet-shaped first resin material extruded from a first die, a first mold roller, and a first nip roller disposed opposite to the first mold roller. , The uneven shape on the surface of the first mold roller is transferred to the first resin material, and the sheet-like second resin material extruded from the second die is transferred to the second mold roller and the second mold roller. The second nip roller disposed opposite to the mold roller is pressed to transfer the uneven shape on the surface of the second mold roller to the second resin material, and the second resin material after the transfer is transferred to the second resin material. The second resin material is peeled off from the second mold roller by being wound around a second peeling roller disposed opposite to the second mold roller, and the second resin material after peeling is applied to the first resin material after transfer. The non-transfer surface of the second resin material is in close contact with the non-transfer surface of the first resin material. Then, the laminate of the first resin material and the second resin material is sandwiched between the first mold roller and the first peeling roller disposed opposite to the first mold roller, There is provided a method for producing a resin sheet, wherein the laminate after being pressed is peeled off from the first mold roller by being wound around the first peeling roller.

  According to the present invention, the uneven shape on the surface of the first mold roller is transferred to the first resin material, the uneven shape on the surface of the second mold roller is transferred to the second resin material, and the second shape after transfer is transferred to the second resin material. The resin material is supplied to the first resin material so that the non-transfer surface of the second resin material is in close contact with the non-transfer surface of the first resin material. Clamping is performed with one peeling roller, and the laminated body after clamping is peeled off from the first die roller.

  In this way, by laminating two types of resin materials that are separately transferred and molded, even if the resin sheet has a large thickness distribution in the width direction at the time of molding, the back surface unevenness that occurs immediately after molding is less likely to occur. The cross-sectional shape can be obtained.

  In this case, for example, an uneven shape having a large thickness distribution in the width direction is formed by the first mold roller, a flat shape is formed by the second mold roller, and the two are laminated to form the back surface (second mold). (Roller side) leveling is performed, and unevenness on the back surface hardly occurs, and a desired cross-sectional shape can be obtained.

  That is, in this specification, the “concave shape on the surface of the second mold roller” refers to a shape in a broad sense including a flat shape without unevenness (the first mold roller is also acceptable).

  Further, for example, the first mold roller forms a concavo-convex shape with a large thickness distribution in the width direction, and the second mold roller forms a concavo-convex shape with a smaller thickness distribution in the width direction, and the two are laminated. Thus, a desired cross-sectional shape can be obtained on the front and back surfaces. 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.

  According to the present invention, the sheet-like first resin material extruded from the first die is sandwiched between the first mold roller and the first nip roller disposed to face the first mold roller, The uneven shape on the surface of the mold roller 1 is transferred to the first resin material, and the radiation curable resin material extruded from the second die is applied to the surface of the continuously running sheet material. On the side of the mold roller, the sheet material is placed on the second nip roller side so that the second mold roller and the second nip roller disposed opposite to the mold roller are sandwiched, and the second The uneven shape on the surface of the mold roller is transferred to the radiation curable resin material, the radiation curable resin material after transfer is irradiated with radiation to be cured, and the cured product of the radiation curable resin material and the sheet material is cured. Opposed to the second mold roller It is peeled off from the second mold roller by being wound around a second peeling roller, and the laminated body of the radiation curable resin material and the sheet material after peeling is transferred to the first resin material, The sheet material is supplied so as to be in close contact with the non-transfer surface of the first resin material, and the laminate of the first resin material, the sheet material, and the radiation curable resin material is combined with the first mold roller and the first material. And sandwiching the first resin material, the sheet material, and the radiation curable resin material after the pressure is wound around the first peeling roller. Accordingly, a method for producing a resin sheet is provided, wherein the resin sheet is peeled off from the first mold roller.

  According to the present invention, the uneven shape of the surface of the first mold roller is transferred to the first resin material, and in parallel with this, the radiation curable resin material is applied to the surface of the sheet material, and the surface of the second mold roller The concavo-convex shape is transferred to a radiation curable resin material and cured, and the laminated body of the cured radiation curable resin material and the sheet material is a non-transfer surface of the first resin material with respect to the first resin material. The laminate of the first resin material, the sheet material, and the radiation curable resin material is sandwiched between the first mold roller and the first peeling roller, and the laminate after the sandwiching is Peel from 1 type roller.

  In this way, by laminating two types of resin materials that are separately transferred and molded, even if the resin sheet has a large thickness distribution in the width direction at the time of molding, the back surface unevenness that occurs immediately after molding is less likely to occur. The cross-sectional shape can be obtained.

  In particular, since one of the resin materials is a radiation curable resin material and can be cured by irradiation with radiation, subsequent back surface unevenness is unlikely to occur and the process becomes easy.

  In this case, for example, an uneven shape having a large thickness distribution in the width direction is formed by the first mold roller, a flat shape is formed by the second mold roller, and the two are laminated to form the back surface (second mold). (Roller side) leveling is performed, and unevenness on the back surface hardly occurs, and a desired cross-sectional shape can be obtained.

  Further, for example, the first mold roller forms a concavo-convex shape with a large thickness distribution in the width direction, and the second mold roller forms a concavo-convex shape with a smaller thickness distribution in the width direction, and the two are laminated. Thus, a desired cross-sectional shape can be obtained on the front and back surfaces. 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 this invention, it is preferable that the said radiation curable resin material is an ultraviolet curable resin, and the said radiation is an ultraviolet-ray. The UV curable resin is suitable for such molding because it is easy to handle and has many types.

  In the present invention, it is preferable that the difference in thickness between the thickest part and the thinnest part in the width direction of the laminate is 1 mm or more due to the uneven shape transferred to the laminate. Moreover, in this invention, it is preferable that the thickness of the thinnest part of the said laminated body is 5 mm or less. Thus, conventional molding is difficult by adopting a configuration of a laminate composed of the first resin material and the second resin material, or a laminate of the first resin material, the sheet material, and the radiation curable resin material. In the molding of the resin material having the cross-sectional shape, the effect of the present invention can be exhibited.

  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, a preferred embodiment (first embodiment) 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 includes a molded part of the resin material 14 that is the first resin material, a molded part of the resin material 54 that is the second resin material, and the downstream cooling zone 30 and the like.

  The molding part of the resin material 14 has a die 12 which is a first die for a sheet for shaping the resin material 14 melted by a first extruder (not shown) into a sheet shape, and an uneven shape is formed on the surface. The first mold roller 16 that is the first mold roller, the nip roller 18 that is the first nip roller disposed opposite to the mold roller 16, and the release roller 24 that is the first release roller disposed opposite to the mold roller 16. And heating means 66 for heating the resin material 14 wound around the mold roller 16.

  The molding part of the resin material 54 has a die 52 which is a second die for a sheet for shaping the resin material 54 melted by a second extruder (not shown) into a sheet shape, and an uneven shape is formed on the surface. The mold roller 56 as the second mold roller, the nip roller 58 as the second nip roller disposed to face the mold roller 56, and the peeling roller 64 as the second peeling roller disposed to face the mold roller 56. And so on.

  The slit size of the die 12 is formed so that the width of the molded molten resin material 14 is wider than the width of the mold of the mold roller 16, and the molten resin material 14 extruded from the die 12 is formed with the mold roller 16. It arrange | positions so that it may extrude between the nip rollers 18. FIG.

  Similarly, the slit size of the die 52 is formed so that the width of the molded molten resin material 54 is wider than the width of the mold of the mold roller 56, and the molten resin material 54 extruded from the die 52 is the mold. The roller 56 and the nip roller 58 are disposed so as to be pushed out.

  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 resin material 14 after a 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 resin material 14 after molding is cut out on a straight line.

  On the other hand, the surface of the mold roller 56 is flat and smooth. In the present embodiment, the surface of the mold roller 56 is flattened, but a regular uneven shape can also be formed like the mold roller 16.

  As described above, the back surface of the resin material 14 is a flat surface, and a linear uneven pattern parallel to the arrow is formed on the surface of the resin material 14. This arrow indicates the traveling direction of the 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. The details of the uneven pattern shape on the surface of the resin material 14 will be described later.

  As the material of the mold rollers 16 and 56, various steel members, stainless steel, copper, zinc, brass, these metal materials having a metal core, rubber lining on the surface, these metal materials are HCr plated, Cu plated, Ni-plated or other plated materials, 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.

  In the case where a regular uneven shape is formed on the surface of the mold roller 56, a similar forming method can be employed. On the other hand, when the surface of the mold roller 56 is formed flat and smooth as in this embodiment, generally, a combination of cutting with a lathe and finishing buffing can be preferably employed.

  The surface roughness of the surfaces of the mold roller 16 and the mold roller 56 is preferably 0.5 μm or less in Ra, and more preferably 0.2 μm or less.

  The mold roller 16 and the mold roller 56 are rotationally driven in a direction indicated by an arrow in FIG. 1 at a predetermined peripheral speed by a driving unit (not shown). The mold roller 16 and the mold roller 56 are provided with temperature adjusting means. By providing such temperature adjusting means, it is possible to control to suppress the temperature rise and rapid temperature drop of the mold roller 16 and the mold roller 56 due to the high temperature resin materials 14 and 54.

  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 so as to face the mold roller 16 and is used to clamp the resin material 14 with the mold roller 16. The nip roller 18 is disposed at the same height as the mold roller 16 on the upstream side in the running direction.

  Similarly, the nip roller 58 is disposed so as to face the mold roller 56 and presses the resin material 54 with the mold roller 56, and is disposed at the same height as the mold roller 56 on the upstream side in the running direction.

  The surfaces of the nip roller 18 and the nip roller 58 are preferably processed into a mirror surface. By setting it as such a surface, the back surface of the resin materials 14 and 54 after shaping | molding can be made into a favorable state. The surface roughness of the surfaces of the nip rollers 18 and 58 is preferably 0.5 μm or less in Ra, and more preferably 0.2 μm or less.

  As materials of the nip roller 18 and the nip roller 58, various steel members, stainless steel, copper, zinc, brass, these metal materials as a core metal, rubber lining on the surface, HCr plating, Cu plating on these metal materials, Ni-plated or other plated materials, ceramics, and various composite materials can be used.

  The nip roller 18 and the nip roller 58 are rotationally driven in a direction indicated by an arrow in FIG. 1 at a predetermined peripheral speed by a driving unit (not shown). In addition, although the structure which does not provide a drive means in the nip rollers 18 and 58 is possible, it is preferable to provide a drive means from the point which can make the back surface of the resin materials 14 and 54 into a favorable state.

  The nip roller 18 and the nip roller 58 are provided with a pressing means (not shown) so that the resin materials 14 and 54 between the mold rollers 16 and 56 can be pressed with a predetermined pressure. This 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 (nip roller 58 and mold roller 56), and is well-known as a motor drive means, an air cylinder, a hydraulic cylinder, or the like. Various means can be adopted.

  The nip roller 18 and the nip roller 58 may be configured so that bending due to the reaction force of the clamping pressure is less likely to occur. As such a configuration, a configuration in which a backup roller is provided on the back side of the nip rollers 18 and 58 (opposite side of the mold rollers 16 and 56), a configuration in which a crown shape (middle and high shape) is adopted, and a central portion in the axial direction of the rollers A configuration of a roller having a strength distribution that increases the rigidity of the roller, a configuration combining these, and the like can be employed.

  The nip roller 18 and the nip roller 58 are provided with temperature adjusting means. The set temperatures of the nip rollers 18 and 58 are the material of the resin materials 14 and 54, the temperature when the resin materials 14 and 54 are melted (for example, the slit exit of the dies 12 and 52), the conveyance speed of the resin materials 14 and 54, the mold The optimum value should be selected according to the outer diameter of the rollers 16 and 56, the uneven pattern shape of the mold rollers 16 and 56, and the like.

  As the roller temperature adjusting means of the nip roller 18 and the nip roller 58, a configuration in which the temperature-controlled oil is circulated inside the rollers 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.

  The peeling roller 24 is disposed opposite to the mold roller 16, and is a roller for peeling the laminated body 34 from the mold roller 16 by winding the laminated body 34 of the resin material 14 and the resin material 54. It is arranged 180 degrees downstream of the nip roller 18 with being sandwiched.

  Similarly, the peeling roller 64 is disposed opposite to the mold roller 56 and is a roller for peeling the resin material 54 from the mold roller 56 by winding the resin material 54. The nip roller 58 is 180 degrees across the mold roller 56. It is arranged downstream.

  The surfaces of the peeling roller 24 and the peeling roller 64 are preferably processed into a mirror surface. By setting it as such a surface, the back surface (resin material 54 side) of the laminated body 34 of the resin material 14 and the resin material 54 after molding can be in a good state. The surface roughness of the surface of the peeling rollers 24 and 64 is preferably 0.5 μm or less in Ra, and more preferably 0.2 μm or less.

  As materials of the peeling roller 24 and the peeling roller 64, various steel members, stainless steel, copper, zinc, brass, those metal materials made of a metal core, rubber-lined on the surface, these metal materials are HCr plated, Cu Plating, plating with Ni plating or the like, ceramics, and various composite materials can be employed.

  The peeling roller 24 and the peeling roller 64 are rotationally driven in a direction indicated by an arrow in FIG. 1 by a driving means (not shown) at a predetermined peripheral speed. In addition, although the structure which does not provide a drive means in the peeling rollers 24 and 64 is possible, it is preferable to provide a drive means from the point which can make the back surface of the resin material 54 and the back surface of the laminated body 34 a favorable state.

  The peeling roller 24 and the peeling roller 64 are provided with temperature adjusting means. Then, by setting the temperature appropriately, the uneven pattern shape on the surface of the resin material 14 and the flat surface of the resin material 54 can be improved.

  The heating means 66 is for heating the resin material 14 wound around the mold roller 16, and at the stage where the resin material 14 is laminated with the resin material 54, the cooling progresses too much and the adhesion with the resin material 54 is poor. It is provided so as not to become.

  As the heating means 66 means, the back surface of the resin material 14 is heated by a configuration in which the temperature-controlled air is ejected from the nozzle toward the resin material 14 and the heating means (nichrome wire heater, infrared heater, dielectric heating means, etc.). Various known means such as the configuration can be adopted.

  The molded part of the resin material 14 and the molded part of the resin material 54, which are composed of the components of the resin sheet production line 10 described above, join between the mold roller 16 and the peeling roller 24. Yes. That is, the resin material 54 wound around the mold roller 16 is laminated with the resin material 54 wound around the peeling roller 64 and peeled off from the mold roller 56, and is sandwiched between the mold roller 16 and the peeling roller 24. And laminated.

  In this case, the back surface of the resin material 14 and the back surface of the resin material 54 are in close contact with each other. The back surface of the resin material 14 is formed flat by the nip roller 18, and the back surface of the resin material 54 is mainly formed by the peeling roller 64. Because it is laminated well.

  It is preferable to provide surface temperature measuring means (not shown) so that the surface temperature of each roller and the resin materials 14 and 54 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 a plurality of points in the width direction of the resin material 14 between the die 12 and the mold roller 16 (the width of the resin material 54 between the die 52 and the mold roller 56). A plurality of points in the width direction of the resin material 14 immediately after the peeling roller 24 (a plurality of points in the width direction of the resin material 54 immediately after the peeling roller 64), and wound around the mold roller 16 and the peeling roller 24. Surfaces of a plurality of points in the width direction of the resin material 14 (opposite surface of the roller) (surfaces of a plurality of points in the width direction of the resin material 54 wound around the mold roller 56 and the peeling roller 64 (opposite surfaces of the rollers) Side)), etc.

  Further, the monitoring result of such surface temperature measuring means can be fed back to the temperature adjusting means of each roller, the dies 12, 52, 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 detection means for detecting the tension of the laminate 34 of the resin material 14 and the resin material 54 is provided on the resin sheet production line 10 in FIG. 1 or downstream thereof, and a plate thickness detection for detecting the plate thickness of the laminate 34. Providing means (thickness sensor) can also be preferably employed.

  The slow cooling zone 30 (or annealing zone) is provided in order to prevent a rapid temperature change of the laminate 34 of the resin material 14 and the resin material 54 downstream of the peeling roller 24. When a sudden temperature change occurs in the laminated body 34, for example, the resin material 14 is in a plastic state while the vicinity of the surface of the resin material 14 is in an elastic state. The surface shape of the material 14 deteriorates. In addition, there is a problem that a temperature difference is generated between the front and back surfaces of the resin material 14 (resin material 54), a temperature difference is generated between the resin material 14 and the resin material 54, and the laminate 34 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 34 can be controlled can be adopted. As the 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 34, and a heating means (nichrome wire heater, infrared heater, dielectric heating means, etc.) is used for lamination. Various known means such as a structure for heating the front and back surfaces of the body 34 can be employed.

  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 34 (all illustrated). Abbreviation).

  Among these, the laminating apparatus is an apparatus for attaching a protective film (a film such as polyethylene) to the front and back surfaces of the laminated body 34, and the side cutter is an apparatus for cutting off both end portions (discarded parts) in the width direction of the laminated body 34. Yes, the cross cutter is a device that cuts the laminated body 34 into 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 resin material 14 and the resin material 54 applied to the present invention, a thermoplastic resin can be used. For example, polymethyl methacrylate resin (PMMA), polycarbonate resin, polystyrene resin, MS resin, AS resin, polypropylene resin, Examples thereof include a polyethylene resin, a polyethylene terephthalate resin, a polyvinyl chloride resin (PVC), a thermoplastic elastomer, a copolymer thereof, and a cycloolefin polymer.

  In the molding part of the resin material 14, the sheet-like resin material 14 extruded from the die 12 is pressed between the mold roller 16 and the nip roller 18 disposed opposite to the mold roller 16, and the uneven shape on the surface of the mold roller 16 is changed to the resin material. 14 is transferred.

  On the other hand, in the molding part of the resin material 54, the sheet-like resin material 54 extruded from the die 52 is pressed between the mold roller 56 and the nip roller 58 disposed opposite to the mold roller 56, so that the flat shape of the surface of the mold roller 56 is obtained. The resin material 54 is transferred to the resin material 54, and the resin material 54 is peeled off from the mold roller 56 by being wound around a peeling roller 64 disposed opposite to the mold roller 56.

  The resin material 54 wound around the mold roller 16 in the molded portion of the resin material 14 is laminated with the resin material 54 wound around the peeling roller 64 and peeled off from the mold roller 56 in the molded portion of the resin material 54. Then, lamination is performed by sandwiching pressure between the mold roller 16 and the peeling roller 24, and the laminate 34 is wound around the peeling roller 24 to be peeled off from the mold roller 16.

  The laminated body 34 peeled off from the mold roller 16 is transported in the horizontal direction, gradually cooled by passing through the slow cooling zone 30, and cut into a predetermined length at the downstream product removing portion in a state where distortion is removed. And accommodate as a resin sheet product.

  In the production of the laminate 34 composed of the resin sheet 14 and the resin sheet 54, the extrusion speed of the resin material 14 (resin material 54) from the die 12 (die 52) is 0.1 to 50 m / min, preferably 0.8. A value of 3 to 30 m / min can be employed. Therefore, the peripheral speed of the mold roller 16 (mold roller 56) and the peripheral speed of the nip roller 18 (nip roller 58) are also made to substantially coincide with 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 (nip roller 58) against the mold roller 16 (mold roller 56) is 0 to 200 kN / in linear pressure conversion (value converted assuming that the surface contact due to elastic deformation of each nip roller is a linear contact). m (0 to 200 kgf / cm) is preferable, and 0 to 100 kN / m (0 to 100 kgf / cm) is more preferable.

  The temperature control of the nip roller 18 (nip roller 58) and the peeling roller 24 (peeling roller 64) is preferably performed for each individual roller. And it is preferable that the resin material 14 (resin material 54) in the location of the peeling roller 24 (peeling roller 64) is the temperature below the softening point Ta of resin. At this time, when a polymethylmethacrylate resin is adopted as the resin material 14 (resin material 54), the set temperature of the peeling roller 24 (peeling roller 64) can be 50 to 110 ° C.

  Next, the detail of the uneven | corrugated pattern shape of the laminated body 34 (resin material 14) surface is demonstrated. As described above, FIG. 2 is a perspective view of a state in which the end surface 14A of the laminated body 34 after being formed is cut off on a straight line. The back surface of the laminate 34 is a flat surface.

  The concavo-convex pattern shape on the surface of the laminate 34 is a linear concavo-convex pattern in the longitudinal direction (arrow direction in the figure). In this pattern, the thickness of the V-shaped groove 90 formed in the thickest part 34B of the laminated body 34 and the plate thickness decreases linearly from both edges of the V-shaped groove 90 toward the thinnest part 34C of the laminated body 34. The tapered portions 92 and 92 are repeated in shape. That is, it is a continuous shape in which the V groove 90 and the taper portions 92 and 92 on both sides, which are line targets with respect to the center line of the V groove 90, are one unit (one pitch).

  In FIG. 2, the thickness of the thinnest portion 34 </ b> C of the laminated body 34 is preferably 5 mm or less, and more preferably 2 mm or less. The difference in thickness between the thickest part 34B and the thinnest part 34C of the laminate 34 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 34 is used as a light guide plate, a cylindrical cold cathode tube is arranged inside the V groove 90, and the light irradiated from the cold cathode tube is laminated from the surface of the V groove 90. The light enters the inside of the body 34, is reflected by the tapered portions 92, 92, and is irradiated in a planar shape from the back surface of the stacked body 34.

  Thus, when using the laminated body 34 after shaping | molding for a light-guide plate, it is preferable that the width | variety p of the V groove 90 shall be 2 mm or more, and the apex angle (theta) 1 of the V groove 90 shall be 40-80 degree | times. preferable. The depth Δt of the V-groove 90 is preferably 1 mm or more, and more preferably 2.5 mm or more. The inclination angle θ2 of the taper portions 92, 92 is preferably 3 to 20 degrees. Further, the width p2 of the tapered portions 92, 92 is preferably 5 mm or more, and more preferably 10 mm or more.

  Next, the other uneven | corrugated pattern shape of the laminated body 34 surface is demonstrated. FIG. 3 is a perspective view of a state in which the end face 34A of the laminated body 34 after molding is cut out on a straight line. The back surface of the laminate 34 is a flat surface.

  The concavo-convex pattern shape on the surface of the laminate 34 is a linear concavo-convex pattern in the longitudinal direction (arrow direction in the figure). This cross-sectionally saw-tooth pattern has a vertical wall 94 connecting the thickest wall portion 34B and the thinnest wall portion 34C of the laminated body 34, and an upper edge (thickest wall portion 34B) of the vertical wall 94. The taper portion 96 whose thickness decreases linearly toward the thinnest wall portion 34C is repeated.

  In FIG. 3, the thickness of the thinnest wall portion 34C of the laminate 34 is preferably 5 mm or less, and more preferably 2 mm or more. The difference in thickness between the thickest part 34B and the thinnest part 34C of the laminate 34 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 34 is used as a light guide plate, a cylindrical cold cathode tube is disposed on the side surface of the vertical wall 94, and light rays irradiated from the cold cathode tube are irradiated on the surface (side surface) of the vertical wall 94. ) Is incident on the inside of the laminated body 34, reflected by the tapered portion 96, and irradiated in a planar shape from the back surface of the laminated body 34.

  Thus, when using the laminated body 34 after shaping | molding for a light-guide plate, it is preferable that the taper part 96 inclination-angle (theta) 3 shall be 3-20 degree | times.

  In addition, when using the laminated body 34 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 90 of the laminate 34 in FIG. 2 is V-shaped, but other shapes such as a rectangular shape, a trapezoidal shape, an arc shape, a parabolic shape, etc. are also possible. It can be used if it satisfies the required characteristics and formability.

  Further, the uneven shape on the surface of the mold roller 16 does not need to be the inverted shape of the surface of the laminated body 34 of FIG. 2 or FIG. It can also be set as the shape offset from this shape so that it may become the shape of 2 or FIG.

  Next, another embodiment (second embodiment) of the method for producing a resin sheet according to the present invention will be described in detail. FIG. 4 is a configuration diagram showing a resin sheet production line 10 ′ to which the resin sheet production method according to the present invention is applied. In addition, the same code | symbol is attached | subjected about the member similar to 1st Embodiment shown by FIG. 1, and the description is abbreviate | omitted.

  In the present embodiment, a radiation curable resin 74 formed on one side of the sheet material 20 is used instead of the resin material 54 of the first embodiment. Hereinafter, the structure of the molding part of the radiation curable resin 74 will be described.

  The molding part of the radiation curable resin 74 includes a sheet feeding means 26 that feeds the continuously running sheet material 20, a die 72 that is a second die that applies the radiation curable resin material 74 extruded onto the surface of the sheet material 20, and a surface. A mold roller 76 that is a second mold roller having a concavo-convex shape formed thereon, a nip roller 78 that is a second nip roller disposed to face the mold roller 76, and a second peeling roller that is disposed to face the mold roller 76. And a radiation irradiating means 82 for curing the radiation curable resin material 74 on the sheet material 20 wound around the mold roller 76.

  The sheet feeding means 26 continuously supplies the sheet material 20. The sheet material 20 is wound around both ends of the support arm 26 </ b> D, and the original roll 26 </ b> A that is being fed and a new (preliminary) original roll. An anti-roll 26B is provided, and by rotating the support arm 26D with the fulcrum 26C as the center of rotation, the sheet material 20 is continuously run, while feeding the original roll 26A and a new (preliminary) original. The anti-roll 26B can be exchanged.

  The radiation curable resin material 74 pushed out from the die 72 is applied to the surface (upper surface) of the sheet material 20 fed out from the sheet feeding means 26 and fed between the mold roller 76 and the nip roller 78. . The shape of the die 72 can be the same as that of the dies 12 and 52 of the first embodiment.

  The surface of the mold roller 76 is flat and smooth. In the present embodiment, the surface of the mold roller 76 is flattened, but it may be a regular uneven shape like the mold roller 16.

  The material of the mold roller 76, the method of forming the uneven pattern (flat pattern) on the surface of the mold roller 76, and the configuration of the mold roller 76 (driving means, temperature adjusting means, etc.) are the same as those of the mold rollers 16 and 56 of the first embodiment. You can do the same.

  The nip roller 78 is disposed opposite to the mold roller 76 and is used to clamp the radiation curable resin material 74 with the mold roller 76. The nip roller 78 is disposed at the same height as the mold roller 76 on the upstream side in the running direction.

  The material of the nip roller 78 and the configuration (driving means, temperature adjusting means, etc.) of the nip roller 78 can be the same as those of the nip rollers 18 and 58 of the first embodiment.

  Between the nip roller 78 and the peeling roller 84, the sheet material 20 coated with the radiation curable resin material 74 is wound around the mold roller 76 with a wrap angle of about 180 degrees. In the meantime, the radiation irradiation means 82 is provided so as to face the sheet material 20. The radiation irradiation means 82 will be described later.

  The peeling roller 84 is disposed to face the mold roller 76, and the sheet material 20 (layer of the radiation curable resin material 74) is wound around the sheet material 20 on which the layer of the cured radiation curable resin material 74 is formed. It is a roller for peeling from the mold roller 76 and is disposed 180 degrees downstream of the nip roller 78 with the mold roller 76 in between.

  The material of the peeling roller 84 and the configuration (driving means, temperature adjusting means, etc.) of the peeling roller 84 can be the same as those of the peeling rollers 24 and 64 of the first embodiment.

  As the sheet material 20, a resin film, a metal foil (such as an aluminum web), or the like can be used. Resin film materials include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, polycarbonate, polyamide, PET (polyethylene terephthalate), biaxially stretched polyethylene terephthalate, polyethylene naphthalate, and polyamideimide. Known materials such as polyimide, aromatic polyamide, cellulose triacetate, cellulose acetate propionate, and cellulose diacetate can be used. Of these, polyethylene terephthalate, polyethylene naphthalate, and polyamide can be preferably used.

  The width of the sheet material 20 is preferably substantially the same size as the width of the resin material 14, and the length of the sheet material 20 is generally 1000 to 100,000 m. However, application of other sizes is not impeded.

  The sheet material 20 may be previously subjected to corona discharge, plasma treatment, easy adhesion treatment, heat treatment, dust removal treatment, and the like. The surface roughness Ra of the sheet material 20 is preferably 3 to 10 nm at a cutoff value of 0.25 mm.

  As the radiation curable resin material 74, a photopolymerizable resin is preferably used. The photopolymerizable resin comprises a photopolymerizable monomer and a polymerization initiator. As this photopolymerizable resin, a known resin that is polymerized with an activation energy beam such as an ultraviolet ray or an electron beam can be employed. The photopolymerizable monomer is composed of a compound having a polymerizable functional group such as a radical polymerizable unsaturated group or an epoxy group. The viscosity of the photopolymerizable resin can be 1 to 2000 mPa · s in an uncured state, and preferably 20 to 100 mPa · s in an uncured state. Further, those which are easily plastically deformed at a degree of polymerization of about 70 to 80% and are difficult to deform in a complete polymerization state are preferred. Moreover, a thing with little shrinkage | contraction at the time of hardening is preferable.

  As such a photopolymerizable resin, an ultraviolet curable resin is preferable. Ultraviolet curable resins are suitable for applications such as the present invention because they are easy to handle and have a wide variety of types.

  As a method of forming the layer of the radiation curable resin material 74 on the surface of the sheet material 20, various known methods can be adopted in addition to the method of using the die 72 of this embodiment. Examples of such methods include a roller coating method, a gravure coating method, a roller coating plus doctor method, an extrusion type coating method, a slide coating method, a spin coating method, a printing method (screen printing method, etc.), a dip coating method, and the like. It is done.

  Next, the radiation irradiation means 82 will be described. As the irradiation light, active energy rays such as ultraviolet rays and electron beams can be employed. In the configuration shown in FIG. 4, the irradiation light passes through the sheet material 20 and is applied to the layer of the radiation curable resin material 74.

When an ultraviolet curable resin is employed as the radiation curable resin material 74, a mercury lamp can be used as the radiation irradiating means 82. As the mercury lamp, for example, those manufactured by Oak Seisakusho (trade name: Handy UV-300, output: 300 W, irradiation intensity: 300 W / cm ² ) can be arranged in the circumferential direction at a predetermined interval.

  Next, a method for producing a resin sheet using the resin sheet production line 10 ′ shown in FIG. 4 will be described.

  In the molding part of the resin material 14, the sheet-like resin material 14 extruded from the die 12 is pressed between the mold roller 16 and the nip roller 18 disposed opposite to the mold roller 16, and the uneven shape on the surface of the mold roller 16 is changed to the resin material. 14 is transferred.

  On the other hand, in the molding part of the radiation curable resin material 74, the radiation curable resin material 74 that is fed from the sheet feeding means 26 and is continuously run and applied from the die 72 is applied to the surface of the sheet material 20. The unevenness on the surface of the mold roller 76 is transferred to the radiation curable resin material 74, and the radiation curable resin material 74 after transfer is irradiated with radiation from the radiation irradiating means 82 to be cured, and the cured radiation curable resin material. The laminate 75 of the sheet material 20 and the sheet material 20 is wound around the peeling roller 84 and peeled off from the mold roller 76.

  The laminated body 75 wound around the peeling roller 84 and peeled off from the mold roller 76 in the molding part of the radiation curable resin material 74 is applied to the resin material 14 wound around the mold roller 16 in the molding part of the resin material 14. The laminate is laminated by pressing between the mold roller 16 and the peeling roller 24, and the laminate 88 is wound around the peeling roller 24 to be peeled off from the mold roller 16.

  The laminated body 88 peeled off from the mold roller 16 is transported in the horizontal direction, gradually cooled by passing through the slow cooling zone 30, and cut into a predetermined length in the downstream product removing portion in a state where distortion is removed. And accommodate as a resin sheet product.

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

  According to the resin sheet manufacturing method (first and second embodiments) according to the present invention described above, a desired cross-sectional shape is obtained even with a resin sheet having a large thickness distribution in the width direction during molding. be able to.

  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.

  Further, the heating means 66, the slow cooling zone 30, and the like can take various aspects other than the present embodiment as long as the same function can be obtained.

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 The block diagram which shows the other example of the production line of the resin sheet to which this invention is applied Configuration diagram showing production line of resin sheet of conventional example

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10 '... Resin sheet production line, 12 ... Die, 14 ... Resin material, 16 ... Mold roller, 18 ... Nip roller, 20 ... Sheet material, 22 ... Guide roller, 24 ... Release roller, 26 ... Sheet feeding means, DESCRIPTION OF SYMBOLS 30 ... Slow cooling zone, 32 ... Peeling part, 34 ... Laminated body, 52 ... Die, 54 ... Resin material, 56 ... Mold roller, 58 ... Nip roller, 64 ... Peeling roller, 72 ... Die, 74 ... Radiation curable resin, 76 ... Form roller, 78 ... Nip roller, 84 ... Peeling roller

Claims (7)

The sheet-shaped first resin material extruded from the first die is sandwiched between the first mold roller and a first nip roller disposed opposite to the first mold roller, and the surface of the first mold roller is Transfer the irregular shape to the first resin material,
The sheet-like second resin material extruded from the second die is pressed between the second mold roller and a second nip roller disposed opposite to the second mold roller, and the surface of the second mold roller is Transfer the uneven shape to the second resin material,
The second resin material after the transfer is peeled off from the second mold roller by wrapping it on a second peeling roller disposed opposite to the second mold roller,
The second resin material after peeling is supplied to the first resin material after transfer so that the non-transfer surface of the second resin material is in close contact with the non-transfer surface of the first resin material. ,
The laminated body of the first resin material and the second resin material is sandwiched between the first mold roller and a first peeling roller disposed opposite to the first mold roller,
A method for producing a resin sheet, wherein the laminate after being pinched is wound from the first mold roller by winding the laminate on the first peeling roller.   The resin sheet according to claim 1, wherein the thickness difference between the thickest portion and the thinnest portion in the width direction of the laminate is 1 mm or more due to the uneven shape transferred to the laminate. Manufacturing method.   The method for producing a resin sheet according to claim 1 or 2, wherein the thickness of the thinnest portion of the laminate is 5 mm or less. The sheet-shaped first resin material extruded from the first die is sandwiched between the first mold roller and a first nip roller disposed opposite to the first mold roller, and the surface of the first mold roller is Transfer the irregular shape to the first resin material,
A radiation curable resin material extruded from the second die is applied to the surface of the continuously running sheet material so that the radiation curable resin material is on the second mold roller side and the sheet material is on the second nip roller side. The second mold roller and the second nip roller disposed opposite to the mold roller are pressed to transfer the uneven shape on the surface of the second mold roller to the radiation curable resin material. Radiation is cured by irradiating the radiation curable resin material,
The laminate of the radiation-cured resin material and the sheet material after curing is peeled off from the second mold roller by wrapping around a second peeling roller disposed opposite to the second mold roller,
Supply the laminated body of the radiation-cured resin material and the sheet material after peeling to the first resin material after transfer so that the sheet material is in close contact with the non-transfer surface of the first resin material. ,
The laminate of the first resin material, the sheet material, and the radiation curable resin material is sandwiched between the first mold roller and a first peeling roller disposed opposite to the first mold roller,
A resin sheet that is peeled off from the first mold roller by winding a laminated body of the first resin material, the sheet material, and the radiation curable resin material after the clamping onto the first peeling roller. Manufacturing method.   The method for producing a resin sheet according to claim 4, wherein the radiation curable resin material is an ultraviolet curable resin, and the radiation is an ultraviolet ray.   Due to the concavo-convex shape transferred to the laminate of the first resin material, the sheet material, and the radiation curable resin material, the thickness difference between the thickest portion and the thinnest portion in the width direction of the laminate is 1 mm or more. The method for producing a resin sheet according to claim 4, wherein:   The thickness of the thinnest part of the laminated body of a said 1st resin material, a sheet material, and a radiation curable resin material is 5 mm or less, The resin sheet of any one of Claims 4-6 characterized by the above-mentioned. Manufacturing method.

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