TW201026481A - Method for producing crystalline resin sheet - Google Patents

Abstract

A method for producing a crystalline resin sheet comprising a step for extruding crystalline resin in a sheet form from a die, a step for forming an extruded sheet by passing the extruded sheet-form crystalline resin through rolling rolls, and a step for conveying the extruded sheet in such a manner that the width direction of the surface of the extruded sheet is kept horizontal, characterized in that the step for conveying the extruded sheet is carried out by bringing the extruded sheet into contact with at least four conveyance rolls arranged in the conveyance direction of the extruded sheet, and includes a total of two or more steps including a step for bringing the upper surface of the extruded sheet into contact with the conveyance rolls in the conveyance direction and then bringing the lower surface of the extruded sheet into contact with the conveyance rolls in the conveyance direction, and/or a step for bringing the lower surface of the extruded sheet into contact with the conveyance rolls in the conveyance direction and then bringing the upper surface of the extruded sheet into contact with the conveyance rolls in the conveyance direction.

Description

201026481 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method for producing a crystalline resin sheet. [Prior Art] In recent years, high planarity has been demanded for the use of a light diffusing plate which is formed on the back of a direct type liquid crystal display. Up to now, as a φ plate, a polymethyl methacrylate (PMMA) resin, a methyl olefin-styrene copolymerization (MS) resin, a polystyrene resin, a polycarbonate (PC> resin, etc. have been used. All of them are amorphous. On the other hand, 'the diffusing plate made of a crystalline resin starting from a propylene resin' is light in weight, mechanically strong, not easily damaged, susceptible to moisture absorption or heat from a light source. In the case of the crystalline resin such as acryl resin, when it is formed by the extrusion method, it is formed from a molten state to a cooling shape. The step is caused by the crystallization, so it is difficult to control the bending of the sheet. As a light diffusing plate used for a backlight for a liquid crystal display, it is required to have a high planarity, so that it is controlled at the time of extrusion molding. It is technically difficult to manufacture a dispersion sheet composed of an acrylic resin or the like which is a crystalline resin. As a method of preventing such warping, conventionally, a method of transporting a roll in a flat state after passing through a calender roll is performed (for example, refer to FIG. 5), but light diffusion is performed in parallel with the conveyance direction. Methyl propyl (PS) resin. Cheng Zhiguang has no idea (for example, the forming side is due to the meeting. In particular, the warping on the bend-formed light-expanding shape (also known as -5 - 201026481 MD direction) only occurs on the section, but does not occur. It is difficult to suppress or control the warp in the direction of the MD. For such a warp direction in the MD direction, in order to influence the bending of the obtained sheet, various kinds of sheets including the concave direction of the MD direction are examined for suppression or For example, Japanese Laid-Open Patent Publication No. 2002-1 20248 (Patent Document 2) discloses a resin sheet 2 that passes through the pressing rolls 3, 4, and 5 as shown in Fig. 6. The heaters 8 and 9 are heated, and then transported by a conventional method to reduce the skewness as a wave. Further, as disclosed in Japanese Patent Laid-Open Publication No. 2002-1 20249 (Patent Document 3), As shown in the figure, in order to adjust the amount of warpage, the resin sheet 2 which is provided to the roller by the bending imparting roller 10 is heated or cooled to control the resin sheet 2 during transportation. The following method of temperature difference. Special opening in Japan 2005-0883 Japanese Patent Publication No. 10 (Patent Document 4) discloses a method of arranging a specific bending imparting roller 20 to suppress the occurrence of warping or adjusting the bending as shown in Fig. 8. [Invention] Technical Problem to be Solved However, in the conventional method, the device for suppressing bending is complicated, and the suppression or adjustment of the bending of the direction in which the extruded sheet is conveyed is insufficient, and there is a so-called conveyance direction. The present invention has an object of the present invention to provide a method for producing a crystalline resin sheet having excellent flatness by a simple method, in order to eliminate the warpage of a sheet containing such a curl. 201026481 [Technical means for solving the problem] The invention includes a process of extruding a crystalline resin into a sheet shape from a die holder, and a process of forming the extruded sheet by pressing the roll of the above-mentioned crystalline resin through a calender roll, and A method for producing a crystalline resin sheet in which a wide range of a sheet surface of an extruded sheet is conveyed so as to be horizontally conveyed, and is characterized by a process of transporting, And the pressing sheet is brought into contact with at least four conveying rollers disposed along the conveying direction φ of the pressing sheet, and includes: adding the upper surface of the pressing sheet to the conveying roller along the conveying direction After the cylinder, the lower surface of the pressing sheet is brought into contact with the conveying roller in the conveying direction, and the upper surface of the pressing sheet is brought along the lower surface of the pressing sheet in contact with the conveying roller in the conveying direction. At least one of the processes in which the conveyance direction is in contact with the conveyance roller, and the method of manufacturing the two or more processes of the crystalline resin sheet is carried out. The process of the conveyance is to bring the extruded sheet into contact with the conveyance direction along the extruded sheet φ. At least four transport rollers are disposed, and the contact is preferably such that one of the upper surface or the lower surface of the extruded sheet is alternately contacted with each of the transport rollers in the transport direction. In the above-described conveyance process, the crystallization temperature of the crystalline resin is Tc (°C), and the four transport rollers that are continuously disposed are in contact with the first conveyance roller in the conveyance direction. When the temperature of the surface of the sheet which is not in contact with the conveying roller is Twarp (°C), it is carried out under the condition that Twarp satisfies the following formula (1).

Tc- 30^ Twarp^ Tc+ 20 ... (1). 201026481 Further, the production method of the present invention is suitable when the crystalline resin is an acrylic resin. According to the present invention, it is possible to suppress or control the warpage of the conveyance direction by a simple method, and to reduce the warpage of the entire sheet, and to suppress the occurrence of undulation of the sheet as compared with the sheet (resin sheet) obtained by the conventional method, and to provide a kind of A resin board excellent in flatness. Further, according to the method of the present invention, since the sheet can be cooled within a short conveyance distance as compared with the conventional method, it can be produced in a small space where the conveyance distance is limited. [Embodiment] Hereinafter, the present invention will be described in more detail. In the following description of the embodiments, the same reference numerals are used in the drawings, and the same reference numerals are used in the drawings. <Production Method of Crystalline Resin Sheet> The method for producing a crystalline resin sheet of the present invention includes a process of extruding a crystalline resin into a sheet shape from a mold base 0, and a sheet form extruded The crystalline resin forms a process of extruding a sheet by calendering the roll, and a process of conveying the extruded sheet in such a manner that the width direction of the sheet surface of the extruded sheet is horizontal. The crystalline resin (hereinafter sometimes referred to simply as a resin) as defined in the present invention, as defined in the Chemical Dictionary (Tokyo Chemical Co., Ltd.), means a polymer compound in a solid state and having a crystalline property, and is in X-ray. The diffraction spectrum shows a resin (polymer) of a crystalline diffraction peak. When a resin sheet having excellent planarity is produced by extrusion molding in the case of a crystalline resin, the occurrence of warpage of the entire sheet including the warp direction in the conveyance direction as described above becomes a problem. It is effective to suppress or eliminate the warpage when the crystalline resin is extruded into a resin sheet. The crystalline resin may be composed of a single unit body, or a copolymer composed of two or more unit bodies may be used. For example, the crystalline resin may be a propylene polymer or a propylene copolymer containing 5% by mass or more of the propylene monomer unit φ. Specifically, the propylene monomer unit content is 75 to 100% by mass. The propylene monomer having a vinyl monomer unit content of 0 to 15% by mass and containing 0 to 25% by mass of a 1-butene monomer unit or a propylene-based copolymer is preferably used. It is preferable that the propylene monomer unit is 95% by mass or more, the ethylene monomer unit is 〇 5% by mass, and the propylene polymer having 〇 to 5% by mass of the 1-butene monomer unit is formed. More preferably, it is composed of a propylene polymer having a propylene monomer unit of 99% by mass or more and an ethylene monomer unit of 〇1 to 1% by mass and containing 0 to 1% by mass of a fluorene-butene olefin monomer unit. Further, the propylene monomer unit content may be 100% by mass. Further, the production method of the present invention is particularly useful for a crystalline resin, but it is also possible to suppress the warpage of the entire sheet when a thermoplastic resin or a thermosetting resin is used. Further, an additive such as a nucleating agent, a light diffusing agent, an ultraviolet absorber, a heat stabilizer, a processing stabilizer, or an antistatic agent may be added to the above resin. The blending amount of such additives is not particularly limited as long as it is adjusted and used within the scope of the present invention. In addition, the amorphous resin other than the crystalline resin may be mixed as long as it does not impair the effects of the present invention. In particular, when the resin constituting the extruded sheet is a propylene-based resin, when the acrylic resin is mixed, the refractive index of the resin is substantially equal, and it is known that the transparency of the obtained resin sheet is not impaired, and rigidity is obtained. The method of improving the mechanical properties is very useful. The light diffusing agent may be an inorganic light diffusing agent or an organic light diffusing agent. Examples of the inorganic light diffusing agent include inorganic compounds such as calcium carbonate, barium sulfate, titanium oxide, aluminum hydroxide, cerium oxide, inorganic glass, talc, mica, white carbon, magnesium oxide, and zinc oxide. Particle @. The inorganic light diffusing agent may be treated with a surface treating agent such as a fatty acid. In addition, examples of the organic light-diffusing agent include particles of an organic compound such as styrene-based polymer particles, acrylic polymer particles, and siloxane-based polymer particles. When the light diffusing agent is added, the absolute enthalpy of the difference between the refractive index of the added light diffusing agent and the refractive index of the resin is generally 0.02 or more from the viewpoint of the effect of light diffusion, and the obtained crystalline resin sheet is obtained. The point of light transmission is generally 0.25 or less. When the light diffusing agent is added to the resin, the crystalline resin sheet obtained by @ can be used as a light diffusing plate. The amount of the light diffusing agent to be added is not particularly limited and may be appropriately adjusted. When the nucleating agent is contained in the above crystalline resin, the crystallization is promoted, and the production efficiency of the sheet can be improved. The nucleating agent can be used as a nucleating agent, for example, in an amount of 0.03 to 1.0 part by mass, based on 100 parts by mass of the crystalline resin, but it is not limited thereto. The process of extruding the crystalline resin into a sheet is carried out using a die holder. -10- 201026481 As such a mold holder, a T-die made of metal which has been conventionally used for extrusion molding can be used. The resin is continuously extruded from the above mold base in a state of being heated and melted, and an extrusion machine similar to the general extrusion molding method can be used for the extrusion. The extruder can be a one-axis extruder or a two-axis extruder. The above crystalline resin is sent to a die holder in a state of being heated and melted in an extruder and pressed. The resin extruded from the die holder is extruded into a continuous sheet shape. The shape of the sheet is not particularly limited, and the thickness and the width are adjusted in accordance with the use of the obtained resin Φ sheet. Further, the extruded sheet may have a single layer structure or a laminated structure of two or more layers. These constitutions may be appropriately changed according to the use of the resin sheet obtained as described above. For example, when the light diffusing plate is used, the total thickness is generally 0.1 mm or more and 3.0 mm or less, preferably 〇5 mm or more and 3.0 mm or less, more preferably 0.8 mm or more and 3.0 mm or less. The crystalline resin extruded into the above-mentioned sheet shape is then supplied to a process of forming a pressed sheet by passing it through a calender roll. Fig. 1 is a schematic cross-sectional view showing the apparatus used for the method for producing a crystalline resin sheet of the present invention. The sheet of the crystalline resin extruded from the die holder 1 is sandwiched between the first pressing roller and the second pressing roller which are the calender rolls, and is formed into a pressing sheet 2 of a desired thickness. It is a first pressing roller and a second pressing roller which are used for the manufacture of such a resin plate, and the diameter is not particularly limited. Further, the first, second, and third pressing rollers may be mirror rollers, or may be shaped by a lens shape, an embossed shape, a magenta shape, or the like, and may be a transfer roller. The surface temperature of the pressing rolls is not particularly limited, but it is generally preferably set at 50 -11 - 201026481 ° C to 150 ° C. When the film is rolled and formed into a pressed sheet under such a temperature condition, the combination with the process of the method for producing a crystalline resin sheet after the present invention can further improve the planarity of the obtained crystalline resin sheet. . The transfer roller is a roller having a transfer mold on its surface. The transfer model is pressed against the surface of the continuous resin sheet, and the surface shape is transferred to the continuous resin sheet in a reverse pattern. The transfer model is composed, for example, of a plurality of concave portions or convex portions provided on the surface of the transfer roller, and the distance between the concave portions or the convex portions is considered to be easy to manufacture, which is generally l〇#m The above is preferably 30/zm or more, and more preferably 50ym or more. Further, the upper limit is not particularly limited, and is generally 50 〇 #m or less, more preferably 250 ym or less. Further, the depth of the groove of the concave portion or the height of the top portion of the convex portion is considered to be 30/zm to 1500/zm from the point of preparation of the transfer model, but it is not limited to this range. The ratio of the groove depth to the interval between the concave portions of the transfer model (@ groove depth/pitch interval)' or the ratio of the top height with respect to the interval between the convex portions (top height/pitch interval), as a resin When a crystalline polymer resin having a crystallizing temperature peak of 9 t or less is used, the ratio is 1 or more, and more preferably 1.2 or more, and an ideal transfer can be carried out. The ratio of the groove depth to the interval between the concave portions of the transfer model (the groove depth/pitch interval) or the ratio of the top height to the interval between the convex portions (the top height/space interval) is generally 5 or less. More preferably 3 or less. The above ratio may also be less than one. -12- 201026481 Fig. 12 is an example of a transfer mold surface, which is a cross-sectional view of a transfer model in which the cross-sectional shape is V-shaped (triangle). In Fig. 12, the cross-sectional shape of the top of the cross-sectional shape and the concave portion or the convex portion is entirely V-shaped (triangle). As shown in Fig. 12, a plurality of concave portions or convex portions are provided in the transfer model, and the distance between the concave portions or the convex portions (P〇 means the distance between the grooves of the adjacent concave portions (P in Fig. 12, ') or the distance between the tops of the adjacent convex portions (P2' in Fig. 12), the groove depth (H·) of the concave portion means the vertical distance from the surface of the transfer roller to the deepest portion of the concave portion, so-called The height of the top of the convex portion means that the vertical distance from the bottom surface of the convex portion to the surface of the transfer roller is the same as the groove depth (ΚΓ) of the concave portion in Fig. 12. When the top of the sectional shape is a V shape (triangle), The apex angle Θ' of the triangle can be made 10°~1〇〇°. The apex angle θ' can also be in the range of 1〇° to 90°. The crystallization temperature peak 作为 is 9 °C. In the case of the following crystalline polymer resin, the apex angle of the triangle is 1 〇. When the fine transfer model is ～60°, the surface shape of the obtained sheet can be accurately and accurately transferred. It is roughly equal to the transfer model. Also, as the shape of the transfer model, In the case of having a V-shaped cross-sectional shape as shown in Fig. 12, for example, a groove having a slightly semicircular concave portion (slightly semicircular concave shape) having a slightly semicircular shape as shown in Fig. 13 or, for example, The apex angle Θ' of the V-shape (triangle) formed by the straight line 11' of the V-groove-curved surface composite shape shown in Fig. 11 and the groove of the concave portion of the curved side 12'. In Fig. 13, the pitch interval ( ρ') is the same as in Fig. 12, and means the distance between the grooves of the adjacent concave portions. The groove depth (Η') of the concave portion means the vertical distance from the surface of the transfer roller to the deepest portion of the concave portion -13 - 201026481 Further, it is as if the slightly semicircular convex portion in which the groove of the semicircular concave portion is inverted is also included in the shape of the transfer model. When the transfer model is formed into a slightly semicircular convex portion, the pitch interval means the distance between the tops of the adjacent convex portions, The height of the top of the convex portion means the vertical distance from the bottom surface of the convex portion to the surface of the transfer roller. The slightly semicircle, as shown in Fig. 13, is not limited to a shape having a semi-arc shape. Alternatively, for example, like a cylindrical lens as shown in Fig. 14, the cylinder is parallel to Any of the arcuate shapes of the section when the axis is cut at a plane free of the axis, or may be a semi-elliptical arc of its cross section, or a flat portion of the semi-elliptical arc The shape of the curved shape, etc. The above-mentioned "slightly semi-circular concave portion" or "slightly semi-circular convex portion" is a concave portion or a convex portion having a cross section of such a semi-circular shape. In Fig. 15, the pitch interval (P) is Similarly to Fig. 12, it means the distance between the grooves of the adjacent concave portions or the distance between the tops of the adjacent convex portions. The groove depth (H') of the concave portion means the deepest portion from the surface of the transfer roller to the concave portion. The vertical distance of the convex portion means that the vertical distance from the bottom surface of the convex portion to the surface of the transfer roller is the same distance from the groove depth (H' Q ) of the concave portion. The above-mentioned V-shaped groove-curved composite shape For example, as shown in Fig. 16, if the cross section is provided with a vertex Θ' of a V-shape (triangle) formed by a straight line 11' and a slope formed by a curved side 12', When cutting at a plane that does not contain the axis of the cylinder containing the surface The shape of the section. The surface to be referred to herein may be a part of an arc shape, or a part of an elliptical arc shape, or may be a shape formed by a curve other than an elliptical arc shape. The above-mentioned "V-groove-curved surface composite shape concave portion" is a concave portion including a cross section of such a substantially V-shaped groove-curved surface. Further, the shape of the concave portion or the convex portion does not include a straight line portion as shown in Fig. 15, and as shown in Fig. 17, a groove having a shape formed by the intersection of the curved line 13' is included. Further, each of the concave portions or the convex portions located in the transfer mold is continuously provided as shown in Fig. 12, and is also provided at any interval d and in parallel as shown in Figs. 13 and 15. The spacing of the recesses or the spacing of the projections is selected based on the use of the resulting sheet. Further, in the present invention, the pitch interval (PO and the groove depth (H1 φ ) or the top height of the transfer model is not necessarily constant in the entire transfer model, and includes a concave portion or a convex portion which is formed adjacent to each other. In the case where the shape is different from each other, it is also included in the scope of the present invention in the case where the V-shaped convex portion in which the V-shaped groove is inverted and the slightly semi-circular convex portion in which the slightly semi-circular groove is inverted is provided. d can be arbitrarily set according to the use of the obtained sheet, but when the crystalline polymer resin having a crystallization temperature peak of 9 ° C or less is used as the resin, even if the interval d' is 1 0 // m or less, or a fine transfer model which cannot be set by using the interval d, or a method of manufacturing a surface shape transfer resin sheet which is excellent in transfer rate or ruthenium production efficiency. The conventional method is exemplified by a gold plating treatment such as chrome plating, copper plating, nickel plating, nickel-plated phosphorous or the like on the surface of a transfer roller composed of the above-described stainless steel or iron steel, and then the plating surface is subjected to the plating treatment. The method of shape processing is performed by using a diamond blade or a metal vermiculite or the like, or laser processing, or chemical etching, but is not limited to the method. Further, the surface of the transfer roller, After the transfer pattern is formed, for example, chrome plating, -15-201026481 copper plating, nickel plating, nickel-phosphorus plating, or the like may be applied to the level which does not impair the accuracy of the surface shape. After the process of pressing the sheet, the process of pressing the sheet to be horizontally conveyed through the width direction of the sheet surface is performed. Here, the sheet is rolled in the horizontal direction by the first pressing roller and the second pressing roller. The latter 'can be transported directly by the transport roller, or can be, for example, shown in FIG. 1 'containing a process of being pressed by the second pressing roller 4 and the third pressing roller disposed on the upper side thereof, and thereafter Further, it is transported by the transporting roller 6. The addition of such a process is adjusted by the crystallization temperature of the crystalline resin used as described later. Further, in the first drawing, the pressed sheet 2 is obtained. For the first pressing roller 3 and the second The pressing roller 4 is conveyed toward the upper side of the die holder 1, but a second pressing roller is disposed on the lower side of the first pressing roller 3, and a third pressing roller is disposed on the lower side. The method of moving the pressed sheet 2 to the lower side of the die holder 1 and then transporting it is also included in the manufacturing method of the present invention (see Fig. 9). Further, the horizontal direction is as long as the sheet surface is wide. The direction of the web may be substantially parallel to the horizontal direction. For example, even if the width direction of the sheet surface is within a range of ±30° from the horizontal direction, the present invention can be effective. In this direction, the sheet is efficiently transported. The point to be considered is, for example, as long as it is set so as not to be separated from the conveyance roller of the sheet due to the inclination. In the present invention, the conveyance process is such that the pressing sheet is in contact with the extrusion. At least four transport rollers arranged in the transport direction of the sheet are carried out, and 'including: the upper surface of the extruded sheet is brought into contact with the transfer roller in the transport direction, and then the lower surface of the extruded sheet is placed along The direction of handling is in contact with the carrying roller The process (hereinafter also referred to as the case of the Α process), and contacting the upper surface of the extruded sheet in the conveying direction after contacting the lower surface of the squeezing-16-201026481 sheet in the conveying direction The process of transporting the rolls (hereinafter also referred to as the case of the B process) is at least one process, and the total is two or more processes. As long as the above-mentioned A process and the above-mentioned B process are included in total of two or more, it is preferable that three or more are preferable, and four or more are preferable. According to the above configuration, since the sheet can be cooled in a short conveyance distance as compared with the conventional method, it can be produced even in a small space where the conveyance distance is limited. Further, it is possible to suppress or control the warpage in the conveyance direction, and to reduce the warpage of the entire sheet, and to manufacture a crystalline resin sheet excellent in flatness compared with the conventional method. In each of the processes of the above-mentioned A process and the B process, the transport roller that is in contact with the lower surface of the extruded sheet, the transport roller that is in contact with the upper surface of the extruded sheet is one, but between the processes, even if When one or more conveyance rolls are provided, the total number of the A process and the B process is two or more, and the present invention can be effective as long as it is in contact with at least four conveyance rolls.亦 that is, at least one process of the above-mentioned A process and B process is performed, and a total of two or more processes are performed, for example, 20 consecutive conveyance rollers in the conveyance direction, or the other conveyance rollers are included therein. Ideally, it is preferably included in the continuous conveyance roller 1 and is preferably contained within 6 continuous conveyance rollers. By including a total of two processes of the A process and the B process in the range of the number of the conveyance rollers described above, it is possible to more effectively suppress or control the warpage of the conveyance direction. Figs. 10(a) to 10(d) are cross-sectional views -17- 201026481 showing the positional relationship between the conveyance roller thus constituted and the conveyed pressed sheet. 10(a) to 10(d) are diagrams showing the case where the six transport rollers include at least one of the above-described A process and B process, and the total number of processes including two processes or more is included. . Figure 10 (a) and Figure 10 (b) include: after the surface of the extruded sheet is in contact with a conveyance roller, and then the lower surface of the extruded sheet is brought into contact with a conveyance roller, Further, the process of contacting the upper surface of the extruded sheet with a conveying roller (B process), and contacting the upper surface of the pressing sheet with a conveying roller, and then contacting the lower surface of the pressing sheet In the process of one transport roller @ (A process), and then the process of contacting the upper surface of the extruded sheet with a transport roller (Fig. 10(a)), or again The process of pressing the lower surface of the sheet to contact with a conveyance roller (Fig. 10(b)). Fig. 10(c) is a process (B process) in which the lower surface of the extruded sheet is brought into contact with one of the conveyance rollers, and the upper surface of the extruded sheet is brought into contact with one of the conveyance rollers. After the coating was applied twice, the upper surface of the extruded sheet was brought into contact with one of the conveyance rollers, and the lower surface of the extruded sheet was brought into contact with a conveyance roller (Process A). Here, in the repeated process D of the B process, since the portion touched by the lower surface of the extruded sheet in the second half of the B process can be regarded as the first half of the A process, the extruded sheet of the first half of the second B process is The part touched by the upper surface is regarded as the second half of the A process. Therefore, in Figure 10 (c), strictly speaking, the A process and the B process are included, and the total includes 4 times, but as a consideration of the various processes along the carrying direction. Convenience, the re-transport roller is not considered between the various processes. That is, in Fig. 10(c), it is included in the A process once and the B process twice, and the total includes three processes. In Fig. 10(d), the process of bringing the surface of the extruded sheet -18·201026481 into contact with a conveyance roller and then contacting the upper surface of the extruded sheet with a conveyance roller is included ( Process B), and the upper surface of the extruded sheet is brought into contact with one of the conveyance rollers, and the upper surface of the extruded sheet is brought into contact with one of the conveyance rollers, and then the lower surface of the extruded sheet is brought into contact with one. The process of transporting the rolls (A process), and the process of bringing the lower surface of the extruded sheet into contact with one of the transfer rolls. In another preferred embodiment of the present invention, the transporting process is performed by contacting the sheet φ with at least four transport rolls. These four rolls are arranged along the conveying direction of the extruded sheets, and are arranged continuously. When the Nth transport roller is used as the Rn from the transport direction, the first transfer can be carried out by means of a device provided by the four rollers of Ri to R4 as a transport roller. The conveying roller can be brought into contact with the pressing sheet so that the four rolls arranged in this manner are in a condition to be described later. For example, when four rolls of R2 to R5 in Fig. 1 are used, the present invention also works. The number of the above-mentioned conveyance rollers is not particularly limited as long as it is at least four, and is not particularly limited. For example, it can be made into ten, and it is considered to be about 300 from the point of the configuration of the apparatus. However, even if the number of the conveyance rollers exceeds this number, the effect of the present invention can be exerted as long as the extruded sheet contacting at least four of the conveyance rollers satisfies the conditions described later. In addition, whether or not it is necessary to adjust the surface temperature of the conveying roller, if the temperature can be arbitrarily adjusted, it is preferable from the point of adjusting the difficulty of bending. Such adjustment of the surface temperature of the conveyance roller may be carried out by a temperature adjustment device built in the conveyance roller or a temperature adjustment device such as a heater provided on the upper and lower sides of the conveyance roller. When the temperature of the conveyance roller is adjusted to heat the extruded thin film -19-201026481, it is preferable because the heat resistance of the obtained crystalline resin plate is further improved. Each of the transport rollers is in contact with either the upper surface or the lower surface of the extruded sheet. However, in the present invention, the at least four transport rollers are formed such that the upper surface and the lower surface are in contact with each other along the transport direction. The form is ideal. Such contact will be specifically described in Figure 1. When the four transport rollers 6 of the transport rollers R! to R4 shown in FIG. 1 are in contact with the extruded sheet 2, the first transport roller Ri in the transport direction contacts @ carries the extruded sheet. At the lower surface of 2, the upper surface of the extruded sheet 2 is contacted with respect to the second conveyance roller R2. Next, the third conveyance roller R3 is in contact with the lower surface of the extruded sheet 2, and the fourth conveyance roller R4 is in contact with the upper surface on which the extruded sheet 2 is conveyed. Further, when the first transporting roller L is in contact with the upper surface of the extruded sheet 2, the second transporting roller R2 is in contact with the lower surface of the extruded sheet 2, and is in contact with the third transporting roller R3. There is an upper surface of the extruded sheet 2, and the lower surface of the extruded sheet 2 is contacted with the fourth conveyance roller R4. Even in such a manner that the sheet is conveyed in such a manner that at least four of the 0 rolls are conveyed so that the upper surface and the lower surface of the extruded sheet are alternately contacted in the conveyance direction, the sheet conveyance direction by the conventional method can be suppressed or eliminated. The concave warp and the overall bending of the sheet. As a result, the planarity of the obtained crystalline resin sheet can be improved. As described above, the method in which the extruded sheet of the A process and the B process is in contact with the conveyance roller, or the upper surface and the lower surface of the extruded sheet are in contact with the conveyance roller, for example, The conveying roller is provided by a conventional guiding roller. Further, as long as at least four conveying rollers are included, at least one of the above-mentioned A process and the B process is included in the package -20-201026481, and the surfaces of the extruded sheets are brought into contact with each other in a total of two processes or more. It is preferable that the surfaces of the above-mentioned extruded sheets are in contact with each other, for example, the contact faces of the fifth conveying rollers of the five conveying rollers and the pressing sheets are not particularly limited, even if more conveying rollers are provided. The occasion is the same. As the conveyance roller, a conventional conveyance roller can be used. Fig. 2 is a schematic cross-sectional view showing the distance between adjacent conveying rollers. The diameter D of each of the transporting rolls can be made to have a desired size, for example, a diameter D of 20 mm to 800 mm is set. When the distance between the center of the Nth transport roller Rn adjacent to the N+1th transport roller Rn+i is P, the pitch P is preferably 30 mm to 2000 mm, and is preferably 100 mm to 800 mm. Ideal. By making such a distance P, the suppression of the cooling and the curling of the sheet is further improved. The pitch P of the adjacent conveyance rollers is not limited to a certain one, and the distance P between the Nth conveyance roller Rn and the N+1th conveyance roller Rn+1 and the N+1th conveyance roller φ cylinder Rn The distance P between +i and the N + 2 transport rollers Rn + 2 may also be different. Further, the ratio P/D of the distance P between the transport rollers and the diameter D is preferably 〇6 to 1 ,, and more preferably 1 to 6. In the first embodiment, the respective transport rollers are arranged at the same height in the vertical direction, but the heights of the adjacent transport rollers in the vertical direction are not necessarily the same. Fig. 3 shows the positional relationship of the adjacent conveying rollers in the vertical direction. When at least four conveyance rolls are sequentially referred to as Rm, Rm+l, Rm + 2, and Rm + 3 in the conveyance direction, and the height position of the extruded sheet and the vertical direction is taken as dA, For example, as shown in the track of Figure 3 - 201026481 (A), the conveyance rollers Rm, Rm+1, Rm + 2, and Rm + 3 are disposed so as to maintain the height of the extruded sheet dA. situation. Further, for example, as shown in the track (B) of Fig. 3, the transport rollers Rm and Rm + 2 are disposed at positions where the height of dA is in contact with the lower surface of the pressed sheet to transport the roller. The center of Rm+1 and Rm+3 is arranged at a higher position than the height of dA. Further, as shown in the track (C) of Fig. 3, all of the transport rollers Rm to Rm + 3 are disposed in the same position in the vertical direction. The transfer rolls Rm and Rm + 2 may be disposed at a position where the height of dA is in contact with the lower surface of the pressed sheet as shown by the track φ (D) in Fig. 3, and the transport roller Rm+1 is disposed. The center of Rm + 3 is lower than dA, that is, it is disposed at a position lower than Rm. Further, the above-described tracks (A) to (D) are exemplified, and the positions in the vertical direction are not limited to those shown in the drawings, and the tracks (A) to (D) are combined, for example, even if the conveyance roller Rm+1 is as a track. (B) As usual, the transport rollers Rm + 3 are arranged as in the track (D), and the positions in the vertical direction of each other are different, and the present invention can also be effective. Among these, even if at least four transport rollers are arranged in the same manner as the tracks shown in the tracks (B) to (D) in Fig. 3, the moving distance of the pressed sheets between the transport rollers is proportional. If the case shown by the track (A) is longer, and the pressed sheet is cooled, the crystalline resin sheet can be produced in a short time. The process of the above-described conveyance is based on the fact that the crystallization temperature of the crystalline resin is T〇(°C), and the four transfer rolls that are continuously disposed are in contact with the first conveyance roller in the conveyance direction. When the temperature of the surface of the sheet on the side where the conveying roller is not in contact is Twarp (°C), it is preferable to carry out the condition that Twarp satisfies the following formula (1-22 to 201026481).

Tc — 30^ Twarp^ Tc + 20 (1) The temperature of the sheet surface, Twarp ( °c ), satisfies the formula (1), and reduces the amount of warpage of the extruded sheet as a whole. The temperature Twarp ( °c ) of the sheet surface is preferably Tc _ 20 ( °c ) or more, and more preferably Tc + 1 ο ( t ) or less. In such a case, the overall bending amount of the extruded sheet can be further reduced. In the manufacturing method of the present invention, in addition to the above-described pressing roller or conveying roller, a roller which is technically unrelated may be provided in the present invention. Such a roller is in contact with the extruded sheet, for example, a guide roller for carrying the extruded sheet along the first pressing roller and the second pressing roller, or carrying the roller. Or to make the pressing sheet adhere to the contact roller of the second pressing roller or the third pressing roller. As such a guide roller or a contact roller, in order to achieve the above object, a conventionally known roller can be applied. The Φ crystalline resin sheet produced by the method for producing a crystalline resin sheet of the present invention is more suitable for use in a backlight device because it is improved in flatness as compared with a resin sheet produced by a conventional method. . EXAMPLES Hereinafter, the present invention will be described in more detail by way of Examples. However, the present invention is not limited thereto. (Example 1) [Production of Intermediate Layer Material Master Compound 1] -23- 201026481 54-by mass parts of propylene-ethylene copolymer (the content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer unit is not sufficient) 1% by mass of 'product name "FSX20L8", manufactured by Sumitomo Chemical Co., Ltd.), and 40.0 parts by mass of styrene polymer particles (average particle size 0.8 / m, trade name "XX3 07K", Sekisui finished product industry ( As a light diffusing agent, 2.0 parts by mass of a processing stabilizer (trade name "IRGAFOS168", manufactured by Ciba-Geigy Co., Ltd.), and 4.0 parts by mass of an antistatic agent (trade name "ELECTS — 2", After being dry-mixed, Kao Co., Ltd. was subjected to sheeting at 180 ° C to 2 50 ° C by a 65 mm two-axis extruder to obtain a sheet-like intermediate layer material mother compound 1. [Production of the intermediate layer material base compound 2] 84.0 parts by mass of the propylene-ethylene copolymer (the monomer content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer unit is less than 1% by mass, and the product name is "FSX20L8". , Sumitomo Chemical Co., Ltd., and 4.0 parts by mass of processing stabilizer (trade name "IRGAFOS168", manufactured by Ciba-Geigy Co., Ltd.), and 4.0 parts by mass of nucleating agent (organic phosphate system, trade name "ΝΑΙ 1 8.0 parts by mass of an antistatic agent (trade name "ELECTS - 2B", manufactured by Kao Corporation), and then dry-mixed at 180 °C to 250 °C by a 65 mm biaxial extrusion. The press was flaky, and a sheet-like intermediate layer material mother compound 2 was obtained. [Production of the surface layer material mother compound] 86.0 parts by mass of the propylene-ethylene copolymer (the monomer content of the propylene monomer unit: 201026481 is 99% by mass or more, and the content of the ethylene monomer unit is less than 1% by mass.) The product name "FSX20L8" , Sumitomo Chemical Co., Ltd., and 5.0 parts by mass of UV absorber (benzotriazole system, trade name "LA31", manufactured by ADEKA), and 5.0 parts by mass of light stabilizer (hindered amine system, trade name) "Tin8 5 5FF", manufactured by Cibajapan Co., Ltd., and 2.0 parts by mass of nucleating agent (trade name "ΝΑΙ 1", manufactured by ADEKA), and 2.0 parts by mass of processing stabilizer (trade name "IRGAFOS168", Ciba-Geigy After being dry-mixed, it was subjected to sheeting at 180 ° C to 260 ° C by a 65 mm two-axis extruder to obtain a sheet-like surface layer mother compound. [Production of Crystalline Resin Sheet] In the first embodiment, a device comprising a roller shown in Fig. 4 was used. The die holder 1 is provided with a main extruder and a sub-extrusion machine (not shown), and the extruders are respectively put into a resin or the like of a ratio to be described later, and are extruded together in a laminated state via the super-multilayer mold base. Out. Q. In a main extruder, 79.0 parts by mass of a propylene-ethylene copolymer (a monomer content of propylene monomer unit of 99% by mass or more and a content of ethylene monomer unit of less than 1% by mass of product name "FSX20L8") was supplied to Sumitomo. Chemical Co., Ltd., and 16.0 parts by mass of the above intermediate layer material mother compound 1 and 5.0 parts by mass of the above intermediate layer material parent compound 2 are dry blended, and are 200 ° C to 2 50 °C to melt it. The melt kneading in the main extruder was carried out at 50.6 rpm and 759 kg/h. In a sub-extruder, 90.0 parts by mass of a propylene-ethylene copolymer (the content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer alone -25,264,481, the content of the product is less than 1% by mass, the product name is " FSX20L8", manufactured by Sumitomo Chemical Co., Ltd., and 1 part by mass of the above-mentioned surface layer parent material, which is dry blended, and melted at 19 ° C to 250 ° C. The melt kneading of the sub-extrusion machine was carried out at 41.5 rpm and 40.0 kg/h. The blended material after melting is extruded through a super-multilayer mold base and at a mold base temperature of 250 ° C to 2 60 t, and is formed by using a roller shown in FIG. 4 to obtain a surface layer of 〇. 〇 5 mm, the intermediate layer (light diffusion layer) is 1.1 mm, and the surface layer is a three-layer structure of 〇.〇5 mm, and the total thickness is 1.2 mm, and the average width is 1400 mm of the crystalline resin plate (A). The crystallization temperature of the obtained resin sheet was 125.1 °C. [Transport Roller] A total of 10 diameters D of 75 mm were used for the transport roller. The relative position of the adjacent conveying rollers is the height in the vertical direction of the pressing sheet of the first conveying roller (R1 in FIG. 4) and the contact point of the pressing sheet when counting along the sheet conveying direction. And the difference between the height of the second conveyance roller (R2 in Fig. 4) adjacent to the roller in the direction in which the roller is moved in the direction of the sheet conveyance is perpendicular to the height of the extrusion sheet of the contact point of the extruded sheet 7 5mm mode configuration (refer to Figure 3C). That is, the heights of the pressing sheets of the first conveying roller Ri and the second conveying roller R2 are substantially the same in the vertical direction. Further, the interval between the adjacent conveyance rollers is 250 mm between the conveyance rollers of Fig. 4 and the distance P shown in Fig. 2, and the conveyance rollers R5 to. . The distance P is made 300mm. Carrying rollers. , set the surface temperature of Table -26- 201026481 to 90 °C. [Transportation Method] Up to the conveyance roller R1Q, the sheet surface of the extruded sheet is sequentially passed through the conveyance roller from the conveyance roller h, and the conveyance roller Rh is passed to the upper side of the conveyance roller. Figure 4). Further, the diameter of the roller after the conveyance roller Rn was 75 mm, the pitch was made φ 3 00 mm ', and the position of the roller in the vertical direction was made the same as r ! Further, the temperature of the surface of the roller after the conveyance of the roller Ru was not adjusted. [Extrusion sheet surface temperature: Twarp] The surface temperature of the sheet is pressed by the first transport roller R which is counted in the conveyance direction, and is the extruded sheet on the side which is not in contact with the conveyance roller. The surface temperature Twarp is U6.0 °C. φ <Evaluation: Bending measurement 1> Three test pieces of a size of 400 mm x 400 mm were cut out at the difference in the width direction of the crystalline resin plate (A) obtained in Example 1. For these test panels, bending measurements were made separately. The bending measurement was carried out on a natural stone platform (600 mm x 600 mm) manufactured by Mitutoyo Co., Ltd., and the total amount of the midpoints and the vertices at the side of the test panel 4 was measured, and the amount of floating from the platform (distance) was measured. . For each test panel, the total amount of floating from the platform at 16 points in the table was measured, and the maximum 値 was used as the amount of warpage (1). The measurement is carried out at room temperature. The results of the respective test panels are shown in Table 1 -27- 201026481 and Table 2. &lt;Evaluation: Bending measurement 2&gt; Three test pieces of a size of 400 mm x 400 mm were cut out in the difference in the width direction of the obtained crystalline resin plate (A). For each of these test panels, a bend measurement by visual inspection was performed. The results of the evaluation of the bending by visual observation were as "〇" when the sheet was not warped, and as "X" when the sheet was bent, and recorded in Table 1. (Example 2) An intermediate layer material mother compound 1, an intermediate layer material mother compound 2, and a surface layer mother material prepared in Example 1 were used, and a crystalline resin sheet was produced by the following method. [Production of crystalline resin sheet] In the second embodiment, an apparatus having a roll having the fourth embodiment shown in the drawings was used. The die holder 1 is provided with a main extruder and a sub-extrusion machine (not shown), and the extruders of these are respectively put into a resin or the like which is described later, and are laminated via a super-multilayer mold base. The state is squeezed out together. The main extruder is supplied with 83.0 parts by mass of a propylene-ethylene copolymer (the content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer unit is less than 1% by mass, and the product name is "FSX20L8", Sumitomo Chemicals Co., Ltd., and 12.0 parts by mass of the above intermediate layer material precursor compound 1, and 5.0 parts by mass of the above intermediate layer material parent compound 2 are dried and mixed with 201026481, and are mixed at 200 ° C to 250 ° °C to melt it. The melt kneading in the main extruder was carried out at 43.6 rpm and 654 kg/h. In a sub-extruder, 90.0 parts by mass of a propylene-ethylene copolymer (the content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer unit is less than 1% by mass, the product name "FSX20L8", Sumitomo Chemical Co., Ltd.) (manufactured by the company) 'and 1 〇. 〇 parts by mass of the above-mentioned surface layer of the mother compound after dry blending, and melted at 19 ° ° ~ 250 ° C. The melt kneading in a secondary extrusion φ press was carried out at 4 8.4 rpm and 4 6.7 kg/h. The blends are melted and formed through a super-multilayer mold base and at a mold base temperature of 250 ° C to 26 (TC - and extruded, and using the roll shown in Fig. 4, the surface layer is 0.05 Mm, the intermediate layer (light diffusion layer) is a three-layer structure of 1.4 mm' surface layer of 0_05 mm, and the total thickness is 1.5 mm, and the average width is 1 400 mm of the crystalline resin plate (B). The crystallization temperature was 125.VC. The obtained crystallinity plate (B) was subjected to the same bending evaluation as that of the crystalline resin plate (A). The results are shown in Table 1 and Table 2. The conveyance roller, the arrangement method, and the method of conveying the extruded sheet were carried out in the same manner as in Example 1. [Extrusion sheet surface temperature: Twarp] The first conveyance roller which was counted by the conveyance direction The surface temperature of the extruded sheet at the time of Ri, and the surface temperature Twarp of the extruded sheet on the side not in contact with the conveyance roller was 119.9 ° C. -29 201026481 (Example 3) was used in the middle of the production of Example 1. Layer material parent compound 1, intermediate layer material mother compound 2 and surface material parent compound, A crystalline resin sheet was produced by the following method. [Production of Crystalline Resin Sheet] In the third embodiment, a device having a roll having the shape shown in Fig. 4 was used. The mold base 1 was provided with a main body. The extruder and the sub-extruder (slightly shown in the figure) are used, and the extruders are respectively put into a resin or the like which will be described later, and are extruded together in a laminated state via the super-multilayer mold base. In the case of the propylene-ethylene copolymer (the propylene monomer unit content is 99% by mass or more, and the ethylene monomer unit content is less than 1% by mass, the product name "FSX20L8", Sumitomo Chemical Co., Ltd.) And 5.0 parts by mass of the above intermediate layer material precursor compound 2 is dry blended and melted at 200 ° C to 250 ° C. The melt kneading in the main extruder is at 36.7 rpm and 550 kg Under the condition of /h, the product was supplied in an amount of 90.0 parts by mass of the propylene-ethylene copolymer (the content of the propylene monomer unit was 99% by mass or more, and the content of the ethylene monomer unit was less than 1% by mass). , the product name "FSX20L8", Sumitomo Chemical Co., Ltd. And 10.0 parts by mass of the above-mentioned surface layer precursor compound is dry-mixed, and melted at 190 ° C to 250 ° C. The melt kneading in the sub-extruder is at 51.8 rpm and 50.0 kg / Under the condition of h. The fusion is melted through the super-multilayer mold base and the mold base temperature is -30-201026481 [extruded sheet surface temperature: Twarp] by the first one along the conveying direction The surface temperature of the extruded sheet when the roll R1 was conveyed, and the surface temperature Twarp of the extruded sheet on the side not in contact with the conveyance roll was 121. (TC. Table 1 Example 1 Example 2 Example 3 Plate thickness 1·2_ 1.5 mm 2.0 mm Linear velocity 7.25 m/min 6.80 m/min 5.74 m/min Traction ratio 1.025/0. 998/0.960 1.025/0.998/0.960 1.025/ 0.998/0.960 a 157.2 157.3 156.3 181.9 183.0 180.1 190.8 190.4 19.03 b 121.5 121.8 120.4 129.6 130.4 130.0 139.5 139.2 137.4 c 117.0 110.1 117.7 125.4 127.0 126.4 136.4 136.6 137.1 d 116.5 112.7 113.8 120.5 118.5 119.5 125.3 124.5 124.8 e 117.4 116.6 117.1 123.6 122.6 122.4 131.0 131.0 131.3 e115.9 114.4 114.9 121.0 119.8 120.8 124.8 124.7 124.2 f on 116.8 116.0 115.6 121.6 119.9 121.0 121.5 120.9 121.3 thin.f under 115.6 114.5 114.9 121.4 121.0 121.6 124.4 124.5 123.8 sheet temperature g on 113.6 111.5 110.5 120.6 120.5 121.9 116.2 115.7 115.0 degrees g under 110.4 109.3 112.1 122.0 121.2 122.1 120,1 119.8 119.5 ec h on 111.0 98.7 99.7 115.5 114.1 115.9 115.1 115.1 115.1 h under 101.4 96.0 99.5 118.2 115.0 115.1 118.7 117.4 117.0 i on 99.1 95.2 96.8 112.0 111.4 113.7 114.2 115.1 115.4 i under 97.4 92.9 96.9 114.5 11 1.5 112.6 117.9 116.8 117.2 j on 93.7 90.0 94.0 one by one 125.2 115.3 127.8 j under 107.7 88.1 93.3 --- 126.2 116.3 128.4 k on 87.6 86.5 87.7 one by one 116.0 112.2 115.3 k under 87.7 94.3 88.8 «Μ一Μ·» 116.7 114.7 116.0 Roll first 75 ° C 70 ° C 702⁄4 barrel temperature second 80 ° C 75eC 75 ° C degree third 88 ° C 90 ° C 88 ° C bending amount (mm) -1.6 -0.9 -1.0 • H) .5 -0.5 -0.4 -0.4 -1.0 -1.2 Undulating ο Ο Ο 〇Ο Ο 〇0 〇-32- 201026481 Degree 250 °C ~ 260 °C - Squeeze out and use the roller shown in Figure 4 A crystalline resin plate (C) having a surface layer of 0.05 mm, an intermediate layer (light diffusion layer) of 1.9 mm, a surface layer of 0.05 mm, and a total thickness of 2.0 mm and an average width of 1400 mm was obtained. . The resulting resin sheet had a crystallization temperature of 125.3 °C. The obtained crystal resin board (C) was subjected to the same bending evaluation as that of the crystalline resin sheet (A). The results are shown in Tables 1 and 2. The conveyance roller, the arrangement method, and the method of conveying the extruded sheet were carried out in the same manner as in Example 1. [Extrusion sheet surface temperature: Twarp] The surface temperature of the sheet is pressed by the first transport roller R which is counted in the conveyance direction, and is the extruded sheet on the side which is not in contact with the conveyance roller. The surface temperature Twarp was 120.9 °C. (Comparative Example 1) @ A crystalline resin sheet was produced by the same method as in Example 2 except that the transportation method was changed to the following conditions. The same bending evaluation as in Example 1 was carried out on the obtained crystalline resin sheet'. The results are shown in Table 2. [Transportation method] The sheet was passed over the upper side of all the conveyance rolls (Fig. 5). The size, pitch, and the like of the transporting rolls are the same as in the second embodiment. -31 - 201026481 In Table 1, the symbols a to k of the sheet temperature are the places where the temperature measurement of the pressed sheet is displayed. These patterns are shown in Fig. 4, in a to k, and measured in width. The sheet temperature at three points different in direction 'the sheet temperatures of these three points are shown in Table 1. Further, the measurement of the symbol f "f" indicates the surface of the pressing sheet 2 which is not in contact with the side of the conveying roller when the conveying roller is brought into contact with the pressing sheet. The symbols e to k other than the above are displayed on the upper surface and the lower surface of the pressed sheet 之前 before the pressing sheet 2 is to be in contact with each of the transporting rolls, by "upper" and "lower", respectively. The linear speed (m/min) is the extrusion speed from the mold base, and the traction ratio is shown on the third pressing roller 5 and the conveying roller 6 and the pressing sheet of the traction roller which is not displayed on the drawing surface. The ratio of the traction ratio is "first" in the column of the roller temperature of the first pressing roller 5 / conveying roller 6 / traction roller = 1.025 / 0.998 / 0.960 ° in the present embodiment and the comparative example. The "second" and "third" respectively display the first pressing roller, the second pressing roller, and the third pressing roller Q. Regarding the amount of warpage, the maximum 値 is displayed, and the "-" before the number 値 indicates that the warp is more concave than the horizontal direction of the sheet conveyance, and the "+" indicates that the warp is more convex than the horizontal direction of the sheet conveyance. Table 2 Bending amount (mm) Example 1 Example 2 Example 3 Comparative Example 1 1.6 0.5 0.4 4.0 0.9 0.5 1.0 6.1 1.0 0.4 1.2 6.0 -33- 201026481 According to the results of Table 2, it is apparent that The amount of warpage of each of the test sheets of the crystalline resin sheet produced by the method of the present invention is suppressed as compared with the test sheet corresponding to the crystalline resin sheet obtained by the conventional method. Moreover, the absolute enthalpy of the amount of warpage was also found to be 5.9 mm at the maximum (Example 4) φ [Production of the intermediate layer material mother compound 3] 85.0 parts by mass of the propylene-ethylene copolymer (propylene monomer) The content of the bulk unit is 99% by mass or more, the content of the ethylene monomer unit is less than 1% by mass, and the product name is "E111G", manufactured by PRIME POLYMER Co., Ltd., and 5.0 parts by mass of the hindered amine light stabilizer (trade name " Chimasorb U9FL", manufactured by Cibajapan Co., Ltd., and 4.0 parts by mass of processing stabilizer (trade name "Sumilizer GP", manufactured by Sumitomo Chemical Co., Ltd.), and 6.0 parts by mass of nucleating agent (trade name "HPN-2") 〇E", @MILIKEN JAPAN Co., Ltd.), after dry blending, is flaky at 180 °C to 260 °C by a 65 mm two-axis extruder to obtain a sheet-like intermediate Layer material parent compound 3. [Production of crystalline resin sheet] In the fourth embodiment, an apparatus having a roll having the ninth drawing was used. The mold base 1 is provided with an extruder, and a resin or the like which is blended in a ratio to be described later is introduced and extruded through a feed module holder in a single layer state. -34-201026481 The main extruder is supplied with 95.0 parts by mass of a propylene-ethylene copolymer (the content of the propylene monomer unit is 99% by mass or more, and the content of the ethylene monomer unit is less than 1% by mass, trade name "E111G", manufactured by PRIME POLYMER Co., Ltd., and 5.0 parts by mass of the above intermediate layer material mother compound 3 are dry blended and fused at 200 ° C to 250 ° C. The melt kneading in the main extruder was carried out at 12.6 rpm and 28 1 kg/h. e that the melted blend is extruded through a feed module holder at a mold base temperature of 25 ° C to 265 ° C and formed using a roll shown in Fig. 9, to obtain a single layer structure, and A crystalline resin sheet (B) having a thickness of 0.6 mm and an average width of 1 00 mm. The resulting resin sheet had a crystallization temperature of 125.0 °C. [Transport Roller] A total of six diameters D of 60 mm were used for the transport roller. The relative position of the conveying roller adjacent to # is the vertical direction of the pressing sheet of the first conveying roller (R! in Fig. 9) which is counted along the sheet conveying direction and the contact point of the extruded sheet. The height, and the height of the second direction of the transport roller (R2 in Fig. 9) adjacent to the roller in the direction in which the sheet is transported, and the height of the extruded sheet of the joint of the extruded sheet The difference is 60 mm (see Fig. 3C). That is, the height of the first conveying roller R and the pressing sheet of the second conveying roller R2 in the vertical direction are substantially the same. Further, the interval between the adjacent transport rollers is the transport roller R!-35-201026481 to R6 in Fig. 9, and the distance P between the two shown in Fig. 2 is 300 mm, and the surface temperature of the transport roller is not adjusted separately. The production of a crystalline resin sheet was carried out under room temperature conditions. [Transportation method] Up to the conveyance roller R6, as shown in Fig. 9, the pressing sheet is brought into contact with the upper side of the conveyance roller R!, the lower side of the conveyance roller R2, and the upper side of the conveyance rollers R3 and r4, and conveyed. The lower side of the rolls R5 and R6 passes, and the conveyance roll R7 is passed after the sheet is brought into contact with the upper side of the conveyance roll. Further, the diameter of the roller after the conveyance of the roller R7 is 60 mm, the pitch is made to be 300 mm, and the temperature of the surface of the roller after the conveyance roller 117 is not adjusted. [Squeezing sheet surface temperature: Twarp] The surface temperature of the extruded sheet at the time of the first conveying roller R1 and the surface temperature of the extruded sheet on the side not in contact with the conveying roller was 111.6 °C. The same evaluation as in Example 1 was carried out on the obtained extruded sheet. The results are shown in Table 3 below. 2 Examples Comparative Γν A crystalline resin sheet was produced by the same method as that of the stomach example 4 except that the transportation method was changed to the following conditions. The same bending evaluation as in Example 1 was carried out on the obtained |^^# resin board. Showing results for -36- 201026481

[Transportation method] The sheet was passed over the upper side of all the conveyance rolls (nh). The size or pitch of the transport roller was made to be in the stomach of Example 4. [Extrusion sheet surface temperature: Twarp] 表面 The surface temperature of the extruded sheet when the first one of the conveyance rollers Ri is counted in the conveyance direction, and the extruded sheet on the side not in contact with the conveyance roller The surface temperature was 112.0. (:. ❹ -37- 201026481

Table 3 Example 4 Comparative Example 2 Plate thickness 0·6 mm 0. 6ππ Linear velocity 3.38 m/min 3.38 m/min Traction ratio 1.012/1.006/1.000 1.012/1.006/1.000 a 127.9 125.9 121.3 A «μ a b 118.0 123.8 116.0 I. C on 107.9 111.6 107.9 one by one under 112.7 113.2 109.2 one by one on 101.3 107.1 96.9 one _ — d under 103.9 107.7 98.8 Μ» one piece of e on 92.7 100.-7 88.9 one _ — warm e under 95.7 103.7 92.6 one - one skin f 92.6 99.3 87.2 one by one g on 83.9 90.2 79.0 one by one g under 86.6 92.3 78.8 one by one h on 79.6 86.1 72,4 one _ — h under 81.4 87.4 74.6 one one i on 71.8 81.7 67.9 One by one i under 78.8 82.8 73.2 one - roller temperature first 90 ° C 903⁄4 brother - 110 ° C 110 ° C degree third 135 ° C 135 ° C 〇〇〇 〇〇〇

According to the method of the present invention, it is known that the configuration of the conventional apparatus can be changed by changing the conveyance method to produce a crystalline resin sheet which is excellent in suppressing the flatness of the warp. The embodiments and examples of the present invention have been described above, and the combinations of the above-described respective embodiments and examples are also intended to be predetermined. The embodiments and examples disclosed herein are to be considered as illustrative and not restrictive in all points -38-201026481. The scope of the present invention is defined by the scope of the claims, and is intended to be inclusive of the scope of the claims. INDUSTRIAL APPLICABILITY Since the crystalline resin sheet produced by the production method of the present invention is excellent in flatness, it is suitably used as a light diffusing plate, that is, a backlight device constituting a device for a direct type liquid crystal display. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an apparatus used in a method for producing a crystalline resin sheet of the present invention. Fig. 2 is a schematic cross-sectional view showing the distance between adjacent conveying rollers. Fig. 3 is a view showing the positional relationship in the vertical direction of the adjacent conveyance rollers. #Fig. 4 is a schematic cross-sectional view showing an apparatus used in the method for producing a crystalline resin sheet of Example 1. Fig. 5 is a schematic cross-sectional view showing the apparatus used in the conventional method for producing a crystalline resin sheet. Fig. 6 is a schematic cross-sectional view showing an apparatus for manufacturing a conventional crystalline resin sheet having a heater. Fig. 7 is a schematic cross-sectional view showing an apparatus for manufacturing a conventional crystalline resin sheet having a bending imparting roller. Fig. 8 is a schematic cross-sectional view showing an apparatus for manufacturing a crystal resin sheet of a conventional junction-39-201026481 having three bending-imparting rolls. Fig. 9 is a schematic cross-sectional view showing the apparatus used in the method for producing a crystalline resin sheet of Example 4. Fig. 10(a) is a schematic cross-sectional view showing a first embodiment of a positional relationship between a conveyance roller and a conveyed pressed sheet, and Fig. 10(b) is a view showing a positional relationship between the conveyance roller and the conveyed pressed sheet. (c) is a schematic cross-sectional view showing a third embodiment of the positional relationship between the conveyance roller and the conveyed pressed sheet, and (d) is a view showing that the conveyance roller is conveyed and conveyed _ A schematic cross-sectional view of a fourth form of the positional relationship of the pressed sheets. Fig. 11 is a schematic cross-sectional view showing the apparatus used in the method for producing a crystalline resin sheet of Comparative Example 2. Fig. 12 is a schematic view showing the sectional shape of a copying mold applied to a V-shaped groove of a transfer mold. Fig. 13 is a schematic view showing the sectional shape of a copying mold applied to a semicircular groove of a transfer mold. Figure 14 is a schematic view of a cylindrical lens. Fig. 15 is a schematic view showing an example of a sectional shape of a copying mold which is applied to a groove of a v-shaped groove-curved surface of a transfer model. Fig. 16 is a schematic view showing an example of a sectional shape of a portion of a groove of a V-shaped groove-curved surface composite shape. Fig. 17 is a schematic view showing another example of the sectional shape of the copying mold applied to the groove of the transfer mold. [Description of main component symbols] -40- 201026481 1 : Mold base 2: extruded sheet 3: first pressing roller 4: second pressing roller 5: third pressing roller 6: conveying roller 7: Traction roller φ 8, 9 : heater 10, 20: bending to the roller -41 -

Claims (1)

201026481 VII. Patent application scope: 1 . A method for producing a crystalline resin sheet, comprising: a process of extruding a crystalline resin into a sheet shape from a mold base, and the above-mentioned crystalline resin in the form of a sheet which is extruded A method for producing a crystalline resin sheet by a process of forming a pressure-receiving sheet by rolling a roll and a process of transporting the extruded sheet so that the width direction of the sheet surface of the extruded sheet is horizontally is characterized in that: The conveyance process is performed by contacting the extruded sheet with at least four conveyance rolls arranged along the conveyance direction of the @extruded sheet, and including: adding the upper surface of the extruded sheet along the conveyance After contacting the conveying roller in the direction, the lower surface of the pressing sheet is brought into contact with the conveying roller in the conveying direction, and after the lower surface of the pressing sheet is brought into contact with the conveying roller in the conveying direction, The upper surface of the extruded sheet is in contact with at least one of the processes of the conveyance roller in the conveyance direction, and is a total of two or more processes. 2. The method for producing a crystalline resin sheet according to claim 1, wherein the conveying process is such that the pressing sheet contacts at least four conveying rollers disposed along a conveying direction of the pressing sheet. The cylinder is carried out, and one of the upper surface or the lower surface of the extruded sheet is alternately brought into contact with each of the transport rollers in the transport direction. 3. The method for producing a crystalline resin sheet according to claim 1 or 2, wherein the transporting process is carried out by using the crystallized tree-42-201026481 to have a crystallization temperature of Te (°C). The temperature of the surface of the sheet which is not in contact with the transporting roller when contacting the first transporting roller in the transport direction among the four transporting rollers arranged in the above-described manner is Twarp (°c) When the above Twarp satisfies the following formula (1), &gt; Tc - 3〇g Twarp^ Tc + 20 (1). 4. The method for producing a crystalline resin Φ plate according to the first, second or third aspect of the invention, wherein the crystalline resin is an acryl resin. -43-