JP2005205683A - Resin substrate and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin substrate having a concavo-convex shape with a high aspect ratio and a method for producing the same.
A resin layer 3 containing a thermoplastic resin is formed on a resin substrate 2, the resin layer 3 has irregularities on the surface thereof, and the height of the irregularities is not less than 5 μm and not more than 2 mm. When the aspect ratio of the unevenness is 1 or more and 100 or less, the glass transition temperature of the thermoplastic resin is Tg1, and the glass transition temperature of the resin substrate 2 is Tg2, Tg1 is 10 ° C. or more and 100 ° C. or less, and Tg1− A resin substrate having Tg2 of 20 ° C. or lower is used. Moreover, the process of preparing the metal mold | die 6 provided with the unevenness | corrugation on the surface, the process of forming the resin layer 3 containing the thermoplastic resin whose glass transition temperature is 100 degrees C or less on the surface of the resin base material 2, and the resin layer 3 On the other hand, a method of manufacturing a resin substrate including a pressing step of pressing and pressing the unevenness of the mold 6 heated to a temperature higher than the glass transition temperature of the thermoplastic resin by 10 ° C. or more.
[Selection] Figure 2

Description

  The present invention relates to a display panel having a fine partition used for an electrophoretic display device, a magnetophoretic display device, an organic electroluminescent element, a light reflecting plate having a concavo-convex shape used for a liquid crystal display device, a light guide plate, etc. The present invention relates to a resin substrate having a fine uneven surface shape used in the manufacturing method and a method for manufacturing the same.

  In recent years, research and development of reflective display devices that use external light as a display device with low power consumption, a thin shape, and a small burden on the eyes have been actively conducted. Electrophoretic display devices have been proposed. In these display devices, colored particles having electric charge or magnetism are sealed between two substrates arranged at a predetermined interval, and the particles are rotated or moved by voltage or magnetism, thereby displaying an image. It is characterized by performing.

  In these display devices, there is a problem that uneven distribution of particles occurs due to the uneven distribution of particles due to aggregation of particles having electric charge or magnetism or movement of particles in the lateral direction. In order to solve this problem, unevenness is formed on the substrate to form fine partition walls, and particles are enclosed between the partition walls to restrict particle aggregation and lateral movement, thereby preventing particle bias and display. A method for preventing unevenness has been proposed (see, for example, Patent Document 1).

  As another display device, a reflective liquid crystal display that performs display by reflecting light incident from the outside is put into practical use as a thin and small display element. As one of the reflectors used in this display device, a substrate is used that reflects and diffuses light by depositing a metal film on a resin substrate having irregularities. In this substrate, it is necessary to control the reflection film on the reflection plate to have appropriate reflection characteristics in order to obtain a bright display by efficiently using outside light. The required reflection characteristics vary from a highly specular reflector to a diffuser diffuser depending on conditions such as the usage environment and display area, and a substrate with an uneven surface suitable for each application is required. It is said that.

  On the other hand, an organic electroluminescent element is being developed as a spontaneous emission type display device. This organic electroluminescent element is a display device that emits light by applying an electric field to a thin film made of an organic compound, and has attracted attention as a display device having the possibility of manufacturing a large-area light emitting element. This display device basically has a structure in which an anode, a light emitting layer, and a cathode are laminated. Light is emitted by recombination of holes injected from the anode and electrons injected from the cathode in the light emitting layer. Observed.

  The organic electroluminescence device may have a structure in which an insulating partition is provided between pixels in order to prevent mixing of organic materials between adjacent pixels and diffusion of holes and electrons injected into the light emitting layer. It has been proposed (see, for example, Patent Document 2), and finer partition walls are indispensable for high definition and multicolor.

Thus, in these display elements, a substrate having a fine and highly accurate uneven shape is used, and various methods have been conventionally used as a method for forming such a fine uneven shape on a resin substrate. Means are used. For example, a method of forming a concavo-convex shape on a substrate using photolithography (see, for example, Patent Document 3), or a method of transferring a concavo-convex shape with a mold using an ultraviolet curable resin (see, for example, Patent Document 4). In addition, a method of directly processing a thermoplastic film into a concavo-convex shape by embossing (for example, see Patent Document 5) is known.
JP 2002-148862 A JP-A-8-227276 (Patent No. 3401356) JP-A-4-243226 JP 2001-260219 A JP 2003-208107 A

  However, in order to form a fine concavo-convex shape on a substrate by photolithography, many complicated processes are required, and thus the concavo-convex shape cannot be easily formed. Further, it is difficult to manufacture a concavo-convex shape having a high aspect ratio of the concavo-convex, that is, a ratio of the height of the bulge to the line width of the concavo-convex bulge, by the conventional photolithography.

  In addition, in the method of transferring the unevenness with a mold using an ultraviolet curable resin, it is necessary to irradiate the resin with ultraviolet rays when forming the unevenness with the mold. When used, there is a problem that ultraviolet rays must be irradiated from the side of the base material not in contact with the mold, and a base material that does not transmit ultraviolet rays cannot be used.

  Furthermore, the method of directly embossing a thermoplastic film requires the substrate to be heated to a temperature close to or above the softening temperature of the substrate, so that even if only the surface is to be processed, the entire substrate is deformed. there's a possibility that. In addition, in a film having an electrode pattern formed on the surface, there is also a problem that it is impossible to form an uneven shape with a high aspect ratio without damaging the electrode.

  The resin substrate of the present invention is a resin substrate in which a resin layer containing a thermoplastic resin is formed on a resin base material, the resin layer having irregularities on the surface thereof, and the height of the convexities of the irregularities is When the aspect ratio of the unevenness is 1 to 100, the glass transition temperature of the thermoplastic resin is Tg1, and the glass transition temperature of the resin substrate is Tg2, the Tg1 is 10 ° C. or more and 100 Or less, and Tg1-Tg2 is 20 ° C or less.

  The method for producing a resin substrate according to the present invention includes a step of preparing a mold having irregularities on the surface, and a resin layer containing a thermoplastic resin having a glass transition temperature of 100 ° C. or lower on the surface of the resin base material. And a pressurizing step of pressing the concavities and convexities of the mold heated to a temperature higher than the glass transition temperature of the thermoplastic resin by 10 ° C. or more against the resin layer. .

  The resin substrate of the present invention can easily form an uneven shape with a high aspect ratio. Moreover, the method for producing a resin substrate of the present invention has a high aspect ratio without deforming the base material on the surface of a base material having a high softening point, a base material that does not transmit light, a base material with electrodes, and the like. It is possible to easily form an uneven shape.

  Embodiments of the present invention will be described below.

  First, an embodiment of the resin substrate of the present invention will be described. An example of the resin substrate of the present invention is a resin substrate in which a resin layer containing a thermoplastic resin is formed on a resin base material, the resin layer having irregularities on the surface thereof, Is an aspect ratio of 1 to 100, the glass transition temperature of the thermoplastic resin is Tg1, and the glass transition temperature of the resin substrate is Tg2, Tg1 is 10 ° C. The temperature is 100 ° C. or lower and Tg1-Tg2 is 20 ° C. or lower. A more preferable range of the height of the convex portion is 10 μm or more and 500 μm or less, a more preferable range of the aspect ratio is 2 or more and 10 or less, a more preferable range of Tg1 is 50 ° C. or more and 90 ° C. or less, and Tg1− A more preferable range of Tg2 is 10 ° C. or less.

  If the height of the convex portion is less than 5 μm, it is difficult to obtain a required aspect ratio, and if it exceeds 2 mm, it is difficult to form the irregularities. Also, if the aspect ratio of the unevenness is less than 1, one of the objects of the present invention, that is, an uneven shape having a high ratio of the height of the protrusion to the line width of the unevenness of the unevenness cannot be achieved. Formation becomes difficult. Furthermore, when Tg1 is less than 10 ° C, it is difficult to maintain the shape, and when Tg1 exceeds 100 ° C, deformation or the like occurs in the resin base material. Moreover, when Tg1-Tg2 exceeds 20 degreeC, a deformation | transformation etc. will arise in a resin base material.

  Here, the aspect ratio of the projections and depressions in this specification means a value obtained by dividing the height value of the projections and depressions of the projections and depressions by the width value of the projections.

  Next, an embodiment of a method for producing a resin substrate of the present invention will be described. An example of the method for producing a resin substrate of the present invention includes a step of preparing a mold having irregularities on the surface, and a resin layer containing a thermoplastic resin having a glass transition temperature of 100 ° C. or higher on the surface of the resin base material. And a pressurizing step of pressing and pressing the unevenness of the mold heated to a temperature higher than the glass transition temperature of the thermoplastic resin by 10 ° C. or more against the resin layer. .

  According to this embodiment, since the shape of the mold can be directly transferred to the resin layer, it is possible to form a fine uneven shape with a high aspect ratio according to the mold shape of the mold. Further, by performing the pressurizing step with a calendar device, it is possible to perform fine uneven processing on a large area by a simple method.

  In addition, when using a resin base material having a high softening temperature, by adjusting the softening temperature of the thermoplastic resin and the heating temperature of the mold or the press plate, an uneven shape is formed under a temperature condition in which the resin base material is not deformed. It is possible. For this reason, it is possible to prevent deformation of the resin base material due to uneven processing, and it is also possible to form an uneven shape without damaging the electrode layer even in the resin base material on which the electrode layer is formed. It is.

  Furthermore, according to this embodiment, since there is no need to irradiate ultraviolet rays at the time of uneven processing, an uneven pattern is formed on a resin substrate that does not transmit light or a resin substrate on which an electrode layer is formed. It is possible to form. Moreover, it is possible to form the partition which has various characteristics irrespective of the kind of resin base material by selecting the kind of thermoplastic resin of the resin layer formed on a resin base material.

  In addition, the uneven | corrugated shape produced here is not limited, It is processed into various uneven | corrugated shapes not only by the grid | lattice form as shown in FIG. 1 mentioned later but by the pattern of metal molds, such as stripe form and honeycomb form. can do.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
First, an embodiment of the resin substrate of the present invention will be described. FIG. 1 is a cross-sectional view (a) and a plan view (b) showing an example of the resin substrate of the present invention. In FIG. 1, a resin substrate 1 of the present embodiment is a resin substrate in which a resin layer 3 containing a thermoplastic resin is formed on a resin base material 2. The resin layer 3 is provided with convex portions 4 and concave portions 5 on the surface, and the height a of the convex portions 4 needs to be 5 μm or more and 2 mm or less, and more preferably 10 μm or more and 500 μm or less. The aspect ratio (a / b), which is a value obtained by dividing the height a of the convex portion 4 by the width b of the convex portion 4, needs to be 1 or more and 100 or less, more preferably 2 or more and 10 or less. is there. Furthermore, when the glass transition temperature of the thermoplastic resin is Tg1 and the glass transition temperature of the resin substrate is Tg2, Tg1 needs to be 10 ° C. or higher and 100 ° C. or lower, more preferably 50 ° C. or higher and 90 ° C. Tg1-Tg2 is required to be 20 ° C. or lower, and more preferably 10 ° C. or lower.

  Examples of the material of the resin substrate 2 include polyolefin resin, polycarbonate resin, polyethylene resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polyurethane resin, polyester resin, fluorine resin, nylon resin, polyvinyl chloride resin, and the like. However, it is not limited to these. In addition, the shape of the resin base material 2 is preferably a planar shape such as a film shape, a sheet shape, or a thin plate shape in consideration of a manufacturing process in which surface processing is performed by hot pressing.

  As said thermoplastic resin, a polyurethane resin, a polyester resin, a polyvinyl alcohol resin, a polyvinyl acetal resin, a fluororesin, an acrylic resin etc. are preferable, for example. This is because these resins are excellent in shape stability after hot pressing. In addition, these resins may be used alone or in combination. Further, other resin components may be mixed as long as the overall thermoplasticity is not lost.

(Embodiment 2)
Next, an embodiment of the method for producing a resin substrate of the present invention will be described.

  FIG. 2 is a process diagram showing an example of a method for producing a resin substrate according to the present invention, in which only the resin substrate and the mold portion are shown in a cross-sectional view. First, as shown in FIG. 2A, a resin layer 3 containing a thermoplastic resin is formed on a resin base material 2. Next, as shown in FIGS. 2 (b) and 2 (c), a mold 6 having a concavo-convex pattern opposite to the concavo-convex shape finally formed on the resin layer 3 is placed on the resin layer 3. By overlapping and pressing the mold 6 with the pressurizing device 7, an uneven shape is formed in the resin layer 3. Here, the mold 6 is preheated before pressurization. Subsequently, as shown in FIG. 2 (d), the mold 6 and the resin layer 3 are peeled to produce a resin substrate 1 having an uneven shape.

  As the resin base material 2, the thing similar to what was used in Embodiment 1 can be used. In the present embodiment, unlike the formation of the concavo-convex shape using an ultraviolet curable resin, it is not necessary to irradiate the resin with ultraviolet rays during processing. For this reason, as the resin base material 2, not only a resin base material having translucency, but also a resin base material that does not transmit ultraviolet light or a resin base material mixed with a filler that absorbs or reflects ultraviolet light is used. It is possible to use. Moreover, in this embodiment, since the uneven | corrugated shape is formed by the process of a thermoplastic resin, the glass transition temperature of resin base material 2 itself is not restrict | limited.

  Another resin layer such as an electrode layer, an electrode pattern, or a hard coat may be present on the surface of the resin substrate 2. In this embodiment, since the thermoplastic resin of the outermost layer is processed into a concavo-convex shape, it is possible to form a concavo-convex shape on the surface even in a resin base material having such another intermediate layer.

  When the glass transition temperature of the thermoplastic resin is Tg1 and the glass transition temperature of the resin substrate 2 is Tg2, Tg1 is preferably 10 ° C. or higher, more preferably 100 ° C. or lower, more preferably 50 ° C. or higher and 90 ° C. It is below ℃. When Tg1 is less than 10 ° C, it is difficult to maintain the shape, and when Tg1 exceeds 100 ° C, deformation or the like occurs in the resin base material.

  Further, Tg1-Tg2 is preferably 20 ° C. or lower, more preferably 10 ° C. or lower. When Tg1−Tg2 exceeds 20 ° C., a high temperature is required when hot pressing the thermoplastic resin. Therefore, when a resin substrate having a shape that is thin and easily deformed like a film is used, the resin substrate 2 It becomes because it becomes easy to deform | transform. In addition, since the thermal conductivity of the resin is generally low, even if Tg1 is higher than Tg2, if the difference is 20 ° C. or less, the resin substrate 2 is not easily deformed.

  As said thermoplastic resin, the thing similar to what was used in Embodiment 1 can be used. Moreover, in order to improve the processing accuracy and strength of the uneven shape after processing, a thermoplastic resin having a reactive substituent such as an isocyanate group or a thermosetting substituent such as an epoxy group can also be used. Furthermore, a mixed resin obtained by mixing a low molecular weight organic compound having these substituents with a thermoplastic resin can also be used. When a mixture of low molecular weight organic compounds is used, it is preferable to increase the reactivity by using a thermoplastic resin having a reactive substituent such as a hydroxyl group or an amino group as the base thermoplastic resin. By forming a concavo-convex shape by heating and pressurizing a resin layer made of these resins, the resin layer 3 having a higher hardness than the original resin can be obtained by performing a curing reaction at room temperature or by heating. In addition, the accuracy and strength of the uneven shape can be improved.

  Moreover, you may mix an organic filler or an inorganic filler in the said thermoplastic resin. When the filler is mixed, the filler ratio is preferably 20% by weight or less based on the total weight of the thermoplastic resin. Further, the size of the filler is preferably smaller than the groove width of the mold to be used, and more preferably half or less of the groove width of the mold. This is because if the amount of filler to be mixed is too large, the formation of the uneven shape of the resin layer 3 may be deteriorated. In addition, if the size of the filler is too larger than the groove width of the mold, it will not be possible to reliably form an uneven shape, and if the size of the filler exceeds one-half of the groove width of the mold This is because there is a tendency for the processing accuracy of the unevenness to decrease.

  The thickness of the resin layer 3 containing the thermoplastic resin may be equal to or greater than the value (H) obtained by dividing the total volume of the groove of the mold 6 in contact with the resin layer 3 by the surface area of the resin layer 3 in contact with the mold 6. The thickness of the resin layer 3 is preferably 1.1 times or more of H, and more preferably 1.5 times or more of H. If it is within this range, the resin is filled in all the grooves of the mold 6, so that the unevenness can be completely formed by pressurization. Further, in the case where a step or unevenness such as an electrode exists on the surface of the resin substrate 2 on the side where the resin layer 3 is formed, the thickness obtained by adding the height of the step or the unevenness to the above H It is necessary to form the resin layer 3 on the surface.

  The thickness of the resin layer 3 is preferably thinner than the thickness of the resin base material 2. This is because if the resin layer 3 is thicker than the resin base material 2, physical properties such as rigidity of the resin base material 2 may be greatly changed by the resin layer 3.

  The resin layer 3 preferably has high adhesion to the surface of the resin base material 2. If the adhesion between the surface of the resin base material 2 and the resin layer 3 is poor, when the resin substrate 1 is removed from the mold 6, peeling occurs between the resin layer 3 and the resin base material 2, thereby forming an uneven shape. This may be difficult.

  The method for forming the resin layer 3 is not particularly limited, but for example, a gravure coating method, a spray coating method or the like is preferable. This is because in the case where other layers such as electrodes are present on the surface of the resin base material 2, it is necessary to form the resin layer 3 under conditions that do not damage the lower layer.

  The material of the mold 6 used in this embodiment is not particularly limited, and a metal mold, a resin mold, or the like can be used. However, the hardness of the mold 6 is higher than the hardness of the resin layer 3 under the temperature conditions during processing. Must be large.

  As a shape of the mold, a planar mold, a roll mold, or the like can be used. When a roll-shaped mold is used, the pressing step can be performed by a calendar device. FIG. 3 is a process diagram showing an example of the method for producing a resin substrate of the present invention using a calendar device, and shows only a portion of the resin substrate in a sectional view. Here, 8 is a calender roll-shaped mold, and 9 is a smooth calender roll. By pressing the mold 8 against the resin layer 3 containing a thermoplastic resin, An uneven shape can be formed in the resin layer 3. According to this method, it is possible to apply a fine unevenness to a large-area substrate by a simple method.

  The calender roll-shaped mold 8 is preferably one in which grooves are directly processed into a roll. However, when it is difficult to directly process grooves into a roll, a planar mold is prepared in advance. A metal mold may be produced by winding the film around a smooth calendar roll. FIG. 4 shows a side view of a mold 12 formed by winding a flat mold 11 around a smooth calendar roll 10. In FIG. 4, reference numeral 13 denotes a joined portion of the wound flat mold 11.

  When the mold 12 is formed by winding a planar mold 11 around the surface of a smooth calender roll 10 and has a repetitive pattern in which the shape of the unevenness of the mold 12 is repeated at a constant period. The length of the outer periphery of the mold 12 after the planar mold 11 is wound is most preferably the same as an integral multiple of the pitch length of the repetitive pattern, but is exactly the same. It is difficult to make it long. However, the difference between the length of the outer periphery of the mold 12 and an integral multiple of the pitch length of the repetitive pattern is within 15%, more preferably within 10% of the pitch length of the repetitive pattern. Alternatively, there is almost no practical problem as long as the difference is not less than 10 μm and any one length selected from the length of 1% of the pitch. However, if the length of the outer periphery of the mold 12 is out of the above range, it may be difficult to form a continuous concavo-convex pattern because inconvenience occurs in the alignment of the concavo-convex pattern at the joint 13 in FIG. is there.

  The heating temperature of the mold at the time of pressurization needs to be a temperature of 10 ° C. or higher with respect to the glass transition temperature Tg1 of the thermoplastic resin, and is preferably a temperature of 120 ° C. or lower. More preferably, the temperature is at least 100 ° C and no more than 100 ° C, and particularly preferably at least 30 ° C and no more than 90 ° C. If the heating temperature of the mold is lower than 10 ° C. with respect to Tg1, the resin layer 3 is hardly deformed, the formation of unevenness becomes incomplete, and the inconvenience that the pressure necessary for forming the unevenness becomes high may occur. . Moreover, when the heating temperature of a metal mold | die exceeds 120 degreeC with respect to Tg1, the problem that the resin base material 2 becomes easy to deform | transform may arise.

  Further, in the case where the pressurization is performed batchwise as shown in FIG. 2, it is preferable to preheat the mold 6 before the pressurization step. This is because it becomes easier to form the unevenness of the resin layer 3.

  Moreover, in the said pressurization process, when pressurizing the surface of the resin base material 2 of the side in which the resin layer 3 is not formed with a pressurization member (for example, a press board, a calender roll), the temperature of the said pressurization member Is preferably set to a temperature lower than the glass transition temperature of the resin substrate 2. Thereby, the rise in temperature of the resin base material 2 can be suppressed, and thermal deformation of the resin base material 2 can be prevented.

  When pressurizing with a calendar device, it is preferable to provide a heating device such as a heating roll or a hot air device and a cooling device such as a cooling roll or a cold air device before and after the pressurizing step. In FIG. 5, the schematic diagram of the calendar apparatus which provided the heating roll 14 and the cooling roll 15 is shown. The resin base material 2 on which the resin layer 3 is formed is heated between the calender roll-shaped mold 8 and the smooth calender roll 9 after the resin layer 3 is heated with the heating roll 14, thereby forming irregularities. The Thereafter, the resin base material 2 is cooled by the cooling roll 15 and peeled off from the mold 8 by the guide roll 16. By heating the resin layer 3 in advance with the heating roll 14, it is possible to form irregularities in a short time, increase the calendar speed, and improve productivity. Further, by peeling the resin base material 2 from the mold 8 while cooling the resin base material 2 with the cooling roll 15, the peelability between the mold 8 and the resin base material 2 is improved, and the formed uneven shape is easily maintained. It is possible.

  The shape of the unevenness to be formed is not particularly limited, but the height of the unevenness of the unevenness is preferably 5 μm or more and 2 mm or less, and more preferably 10 μm or more and 500 μm or less. The aspect ratio of the irregularities is preferably 1 or more and 100 or less, and more preferably 2 or more and 10 or less. In the method using photolithography or the method of directly embossing the resin base material, it is difficult to form the unevenness having the aspect ratio of 1 or more and the height of the protrusion of 5 μm or more. is there. In addition, when the height of the convex portion exceeds 2 mm, or when the aspect ratio exceeds 100, when the resin base material is peeled from the mold, there is a high possibility that a part of the concave and convex portions will be damaged. In some cases, complete formation cannot be performed.

  Hereinafter, the present invention will be described based on examples. However, the present invention is not limited to the following examples.

(Example 1)
A polyethylene terephthalate (PET) film (manufactured by Teijin, glass transition temperature (Tg): 70 ° C.) was used as the resin substrate, and a urethane resin (“UR8200” manufactured by Toyobo, Tg: 73) was used as the thermoplastic resin on the surface of this PET film. 30 wt.% Methyl ethyl ketone solution was applied to form a resin layer made of urethane resin having a thickness of 40 μm. Next, the metal mold | die used as a model was mounted on the lower heating board of a press, and the metal mold | die was heated at 110 degreeC. As a press machine, a hydraulic molding machine manufactured by Toho Machinery Co., Ltd. is used. As a mold, a groove is formed in a grid pattern with a width of 50 μm, a depth of 60 μm, and a pitch of 200 μm. A planar nickel mold was used. Subsequently, on the heated mold, the urethane resin layer side of the resin base material is overlaid, the temperature of the upper hot platen of the press machine is set to 30 ° C., the pressure is set to 100 MPa, and the heat press is performed for 3 minutes. And a resin substrate of Example 1 was obtained. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of the resin substrate was observed with an optical microscope, a lattice pattern having a convex width of 50 μm and a pitch of 200 μm was formed. Moreover, when the height of the convex portion was measured using a stylus type surface roughness meter (“DEKTAK3ST” manufactured by Veeco), the height was 60 μm and the aspect ratio was 1.2.

(Example 2)
A resin substrate of Example 2 was obtained in the same manner as Example 1 except that the mold groove width was 20 μm. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of the resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 20 μm, a pitch of 200 μm, and a height of 60 μm was formed, and the aspect ratio was 3.

(Example 3)
A resin substrate of Example 3 was obtained in the same manner as in Example 1 except that the groove width of the mold was 10 μm. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 10 μm, a pitch of 200 μm, and a height of 60 μm was formed, and its aspect ratio was 6.

Example 4
A PET film is coated with a 30 wt% methyl ethyl ketone solution of polyvinyl acetal resin (“BH-3” manufactured by Sekisui Chemical Co., Ltd., Tg: 71 ° C.) to form a resin layer made of polyvinyl acetal resin having a thickness of 35 μm. A resin substrate of Example 4 was obtained in the same manner as in Example 1 except that the groove width was 40 μm and the mold temperature was 105 ° C. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 40 μm, a pitch of 200 μm, and a height of 60 μm was formed, and its aspect ratio was 1.5. .

(Example 5)
A resin substrate of Example 5 was obtained in the same manner as Example 4 except that the groove width of the mold was 20 μm. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of the resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 20 μm, a pitch of 200 μm, and a height of 60 μm was formed, and the aspect ratio was 3.

(Example 6)
A PET film is coated with a 30 wt% toluene solution of a polymethyl methacrylate resin (Mitsubishi Rayon “Dianar BR106”, Tg: 50 ° C.) to form a resin layer made of a polymethyl methacrylate resin having a thickness of 35 μm. A resin substrate of Example 6 was obtained in the same manner as in Example 1 except that the mold temperature was 90 ° C. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 50 μm, a pitch of 200 μm, and a height of 60 μm was formed, and its aspect ratio was 1.2. .

(Example 7)
A resin substrate of Example 7 was obtained in the same manner as Example 6 except that the groove width of the mold was 30 μm. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 30 μm, a pitch of 200 μm, and a height of 60 μm was formed, and its aspect ratio was 2.

(Example 8)
In the same manner as in Example 1, a resin layer made of a urethane resin was formed on the surface of the PET film. The calender apparatus shown in FIG. 5 is used for this resin base material, the temperature of the heating roll 14 is 150 ° C., the temperature of the mold 8 is 150 ° C., the temperature of the opposing calender roll 9 is 30 ° C., and the temperature of the cooling roll 15. Was set to 10 ° C., and hot pressing was performed at a pressure of 20 MPa and a passing speed of 2 m / min to obtain a resin substrate of Example 8. As the mold 8, a plate-shaped mold having a thickness of 20 μm, a depth of 30 μm, a pitch of 1 mm and a groove formed in a lattice pattern and having a thickness of 0.3 mm, a diameter of 191.0 mm and a circumference of 60.12 mm A mold wound around a smooth roll was used. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 20 μm, a pitch of 1 mm, and a height of 30 μm was formed, and its aspect ratio was 1.5. .

(Comparative Example 1)
A resin substrate of Comparative Example 1 was obtained in the same manner as Example 2 except that the temperature of the mold was set to 80 ° C. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 20 μm and a pitch of 200 μm was formed, but the convex portion height varied in the range of 5 μm to 20 μm. The formation of irregularities was incomplete.

(Comparative Example 2)
A PET film is coated with a 30 wt% toluene solution of polymethyl methacrylate resin (Mitsubishi Rayon “Dianar BR80”, Tg: 105 ° C.) to form a resin layer made of a polymethyl methacrylate resin having a thickness of 35 μm. A resin substrate of Comparative Example 2 was obtained in the same manner as in Example 7 except that the mold temperature was 110 ° C. When the resin substrate reached room temperature, it was removed from the mold and the shape was observed. As a result, no deformation of the PET film was observed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 30 μm and a pitch of 200 μm was formed, but the convex portion height varied in the range of 5 μm to 10 μm. The formation of irregularities was incomplete.

(Comparative Example 3)
A resin substrate of Comparative Example 3 was obtained in the same manner as Comparative Example 2 except that the mold temperature was 145 ° C. When the resin substrate reached room temperature, it was removed from the mold and the shape was confirmed. As a result, a part of the PET film was deformed. When the surface of this resin substrate was observed and measured in the same manner as in Example 1, a lattice pattern having a convex portion width of 30 μm, a pitch of 200 μm, and a height of 60 μm was formed, and its aspect ratio was 2.

  Table 1 shows the results of Examples 1 to 8 and Comparative Examples 1 to 3. In Table 1, (A) is a value obtained by subtracting the Tg of the PET film (resin base material) from Tg of the thermoplastic resin, and (B) is a value obtained by subtracting the Tg of the thermoplastic resin from the mold temperature.

 As is clear from Table 1, in Examples 1 to 8, a high aspect ratio concavo-convex shape is formed without deforming the resin base material by setting the Tg of the thermoplastic resin and the mold temperature to specific conditions. We were able to. On the other hand, in Comparative Example 1 and Comparative Example 2, since the value (B) obtained by subtracting the Tg of the thermoplastic resin from the mold temperature was less than 10 ° C., the unevenness formation state was incomplete. Moreover, in Comparative Example 3, since the Tg of the thermoplastic resin exceeded 100 ° C., the resin base material was deformed.

  FIG. 6 shows an enlarged photograph of the resin substrate having projections and depressions produced in Example 3. This enlarged photograph is a photograph taken from directly above the resin substrate with an optical microscope having a magnification of 100 times. As is apparent from FIG. 6, it can be seen that a fine lattice pattern having a high aspect ratio is formed on the surface of the resin substrate of Example 3 with high accuracy.

  As described above, since the resin substrate according to the present invention can easily form fine irregularities on the surface thereof, it is possible to provide a reflective display device such as an electrophoretic type or a magnetophoretic type, a liquid crystal display, an organic electroluminescent element, etc. It can be used as a substrate, and can also be used for a resin substrate having a fine uneven surface shape used for a projection screen panel, a lens sheet or the like.

It is sectional drawing (a) and a top view (b) which show an example of the resin substrate of this invention. It is process drawing which shows an example of the manufacturing method of the resin substrate of this invention. It is process drawing which shows an example of the manufacturing method of the resin substrate of this invention using a calendar apparatus. It is a side view of the metal mold | die formed by winding a planar metal mold | die around a smooth calendar roll. It is a schematic diagram of the calendar apparatus provided with the heating roll and the cooling roll. 4 is an enlarged photograph of a resin substrate having unevenness produced in Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin substrate 2 Resin base material 3 Resin layer 4 Convex part 5 Concave part a Convex part height b Concave part width 6 Flat die 7 Pressurizer 8 Calender roll die 9 Calender roll 10 Calender roll 11 Flat surface Shaped mold 12 Mold 13 formed by winding a planar mold 13 Joint 14 Heating roll 15 Cooling roll 16 Guide roll

Claims (8)

A resin substrate in which a resin layer containing a thermoplastic resin is formed on a resin base material,
The resin layer has irregularities on its surface,
The height of the uneven convex part is 5 μm or more and 2 mm or less,
The aspect ratio of the unevenness is 1 or more and 100 or less,
Tg1 is 10 ° C. or more and 100 ° C. or less, and Tg1-Tg2 is 20 ° C. or less, where Tg1 is the glass transition temperature of the thermoplastic resin and Tg2 is the glass transition temperature of the resin base material. substrate.   The resin substrate according to claim 1, wherein the thermoplastic resin is at least one resin selected from a polyurethane resin, a polyester resin, a polyvinyl alcohol resin, a polyvinyl acetal resin, a fluororesin, and an acrylic resin. Preparing a mold with irregularities on the surface;
Forming a resin layer containing a thermoplastic resin having a glass transition temperature of 100 ° C. or lower on the surface of the resin substrate;
A pressurizing step of pressing and pressing the unevenness of the mold heated to a temperature higher than the glass transition temperature of the thermoplastic resin by 10 ° C. or more against the resin layer;
A method for producing a resin substrate, comprising:   The method for producing a resin substrate according to claim 3, wherein the mold has a roll shape, and the pressing step is performed by a calendar device.   The mold is formed by winding a planar mold around the surface of the calendar roll, and has a repetitive pattern in which the shape of the unevenness of the mold is repeated at a constant cycle, and the outer periphery of the mold 5. The method of manufacturing a resin substrate according to claim 4, wherein a difference between the length of the repetitive pattern and an integral multiple of the pitch length of the repetitive pattern is within 15% of the pitch length of the repetitive pattern.   The method further includes a step of pressing a cooling roll set at a temperature lower than the glass transition temperature of the thermoplastic resin against the surface of the resin base material on the side where the resin layer is not formed after the pressurizing step. Item 6. The method for producing a resin substrate according to Item 4 or 5.   The method for producing a resin substrate according to claim 3, further comprising a step of heating the resin layer before the pressurizing step.   In the pressurizing step, the surface of the resin base on the side where the resin layer is not formed is further pressurized with a pressurizing member, and the temperature of the pressurizing member is lower than the glass transition temperature of the resin base. The manufacturing method of the resin substrate in any one of Claims 3-7 set.

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