JP2005161529A - Manufacturing method of embossed sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an embossed sheet capable of increasing an aspect ratio of the unevenness and pitch of a fine embossed pattern and suitable for manufacturing the embossed sheet free from a flaw and having antireflection effect or the like. <P>SOLUTION: In the manufacturing method of the embossed sheet for forming the regular embosses of an embossing mold to the almost whole surface of a sheetlike material by transfer, a resin layer comprising a photopolymerizable resin is formed on the surface of the sheetlike material to be closely brought into contact with the embossing mold so as to be allowed to follow the embossed shape of the embossing mold and this resin layer is subsequently irradiated with light to produce the adhesive force between the resin layer and the embossing mold. In a state that the resin layer and the embossing mold are partially bonded, the sheetlike material and the embossing mold are allowed to be spaced apart from each other by a predetermined distance and the height of the embossed shape formed to the resin layer is made larger than that of the embossed shape of the embossing mold. Thereafter, the resin layer is irradiated with light and polymerized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a concavo-convex sheet, and more particularly, a concavo-convex sheet suitable for producing a sheet-like material such as an optical sheet having an antireflection effect and the like having a regular fine concavo-convex pattern formed on the surface. It relates to the manufacturing method.

  In recent years, an optical sheet having an antireflection effect has been adopted for use in electronic displays such as liquid crystals. In addition, a flat lens such as a lenticular lens or a fly-eye lens, an optical sheet such as a light diffusion sheet, a brightness enhancement sheet, or an optical waveguide sheet is used. As such an optical sheet, conventionally, an optical sheet made of a multilayer film and an optical sheet having a regular fine concavo-convex pattern formed on the surface are known.

  As an example of the former, it is common to use a multilayer film in which a layer having a low refractive index in steps from a high refractive index is laminated on the surface of the film (see Patent Document 1, etc.). However, this configuration requires a multilayer film with a controlled film thickness, and it is difficult to stabilize the quality of the product. Have.

  On the other hand, as the latter example, there is a configuration in which a regular fine uneven pattern is formed on the surface of the film, thereby obtaining an antireflection effect. For example, an antireflection effect can be obtained by forming a regular fine concavo-convex pattern such as a cone or a pyramid on the surface of the film and making the arrangement pitch of the cones sufficiently smaller than the wavelength of visible light. .

  As a method for forming such a regular fine concavo-convex pattern, a method of applying a photoresist on the surface of a film and performing etching after exposure can be adopted, but there are many man-hours and productivity is low. There is a point.

In order to solve such problems, a stamper (original) having a regular fine uneven pattern formed on the surface is prepared in advance, and this stamper is pushed onto a film having a photo-curing resin layer formed on the surface. A so-called photopolymerization method has been proposed in which a photocuring resin layer is photopolymerized (cured) after following a fine concavo-convex pattern, and then released to obtain an optical sheet (Patent Literature). (See 2nd grade).
JP 2001-127852 A JP 2003-149405 A

  However, even the conventional techniques as described above (Patent Document 2 and the like) have problems that cannot be solved. That is, in order to obtain good characteristics as an optical sheet, the aspect ratio between the unevenness and pitch of the fine unevenness pattern must be increased, but it is difficult to produce a stamper (original) for forming such a shape. It is. Moreover, even if the stamper can be manufactured, the cost becomes very high. Furthermore, when using a stamper having such a shape to copy the photo-curing resin layer to the fine concavo-convex pattern of the stamper, the resin does not follow the fine concavo-convex pattern, and a good transfer shape cannot be obtained. . In addition, since the contact area between the stamper and the resin becomes large, there is a problem that the resin is likely to cohesively break at the time of mold release.

  The present invention has been made in view of such circumstances, and is a method for producing a concavo-convex sheet in which a regular fine concavo-convex pattern is formed on the surface, and the aspect ratio between the concavo-convex of the fine concavo-convex pattern and the pitch is determined. It is an object of the present invention to provide a method for producing a concavo-convex sheet suitable for producing an optical sheet or the like that can be enlarged, has no defects, and has an antireflection effect.

  In order to achieve the above object, the present invention provides a method for producing a concavo-convex sheet in which a concavo-convex concavo-convex shape is transferred and formed on substantially the entire surface of a sheet-like body. A step of forming a resin layer, a step of closely adhering the resin layer of the sheet-like body to the concavo-convex shape, imitating the resin layer to the concavo-convex shape of the concavo-convex shape, and irradiating the resin layer with light, With the step of generating an adhesive force between the resin layer and the concavo-convex mold and the resin layer and the concavo-convex mold being partially bonded, the sheet-like body and the concavo-convex mold are separated by a predetermined distance. The step of increasing the height of the concavo-convex shape formed in the resin layer from the height of the concavo-convex shape of the concavo-convex type, and the step of polymerizing the resin layer by irradiating the resin layer with light. Provided is a method for producing a featured uneven sheet.

  According to the present invention, the resin layer of the photopolymerizable resin of the sheet-like body is brought into close contact with the concavo-convex shape, the resin layer is made to follow the concavo-convex shape of the concavo-convex shape, and then the resin layer is irradiated with light. An adhesive force is generated between the layer and the concavo-convex mold, and the sheet-like body and the concavo-convex mold are separated by a predetermined distance in a state where the resin layer and the concavo-convex mold are partially adhered. Thereby, the height of the concavo-convex shape formed in the resin layer can be increased from the height of the concavo-convex shape of the concavo-convex shape. That is, even if a concavo-convex mold in which the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern is less than the required level is used, the concavo-convex sheet that satisfies the required level of the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern can be manufactured.

  Here, the aspect ratio refers to the ratio between the uneven height of the fine uneven pattern (the difference in height from the bottom to the top of the uneven structure) and the pitch of the uneven pattern.

  In addition, after increasing the height of the concavo-convex shape formed on the resin layer, the resin layer is irradiated with light and polymerized, and the sheet-like body is released from the concavo-convex shape, thereby obtaining the desired concavo-convex shape. A sheet is obtained.

  Further, the present invention provides a method for producing a concavo-convex sheet in which concavo-convex concavo-convex is transferred and formed on substantially the entire surface of the sheet-like body, and a step of forming a resin layer of a photopolymerizable resin on the surface of the sheet-like body. A step of bringing the resin layer of the sheet-like body into close contact with the concavo-convex mold, and imitating the resin layer to the concavo-convex shape of the concavo-convex mold, and irradiating the resin layer with light to polymerize the resin layer And a step of generating an adhesive force between the resin layer and the concavo-convex mold, a step of heating the resin layer so as to be equal to or higher than the glass transition temperature Tg of the resin, the resin layer and the concavo-convex In a state where the mold is partially bonded, the sheet-like body and the concavo-convex mold are separated from each other by a predetermined distance, and the height of the concavo-convex shape formed on the resin layer is increased from the height of the concavo-convex shape of the concavo-convex mold. And the glass transition temperature Tg of the resin to the resin layer To provide a method of manufacturing indented sheet which comprises the steps of applying a cooling so below, the.

  According to the present invention, the resin layer of the photopolymerizable resin of the sheet-like body is brought into close contact with the concavo-convex shape, the resin layer is made to follow the concavo-convex shape of the concavo-convex shape, and then the resin layer is irradiated with light. In the state where the resin layer and the concavo-convex mold are partially adhered, after the layer is polymerized, an adhesive force is generated between the resin layer and the concavo-convex mold, and the resin layer is further heated. The concavo-convex mold is separated by a predetermined distance. Thereby, the height of the concavo-convex shape formed in the resin layer can be increased from the height of the concavo-convex shape of the concavo-convex shape. That is, even if a concavo-convex mold in which the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern is less than the required level is used, the concavo-convex sheet that satisfies the required level of the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern can be manufactured.

  After increasing the height of the concavo-convex shape formed in the resin layer, the resin layer is cooled and cured so as to be equal to or lower than the glass transition temperature Tg of the resin, and the sheet-like body is separated from the concavo-convex mold. By molding, the desired uneven sheet can be obtained. This cooling includes not only active cooling such as air blow, but also passive cooling such as natural cooling.

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

  Further, the present invention provides a method for producing a concavo-convex sheet by transferring concavo-convex irregularities on substantially the entire surface of a sheet-like body, and a step of forming a resin layer of a thermoplastic resin on the surface of the sheet-like body; And a step of causing the resin layer of the sheet-like body to adhere to the concavo-convex mold to cause the resin layer to follow the concavo-convex shape of the concavo-convex mold and to generate an adhesive force between the resin layer and the concavo-convex mold And maintaining the resin layer in the vicinity of the glass transition temperature Tg of the resin, and in a state where the resin layer and the concavo-convex mold are partially adhered, the sheet-like body and the concavo-convex mold are predetermined. Separating the distance and increasing the height of the concavo-convex shape formed on the resin layer from the height of the concavo-convex shape of the concavo-convex mold, and cooling the resin layer so as to be equal to or lower than the glass transition temperature Tg of the resin. And a step of applying To provide a method of manufacturing Jo sheet.

  According to the present invention, the resin layer of the thermoplastic resin of the sheet-like body is brought into close contact with the concavo-convex shape so that the resin layer is imitated with the concavo-convex shape of the concavo-convex shape, and the adhesive force is between the resin layer and the concavo-convex shape. The resin layer is maintained in the vicinity of the glass transition temperature Tg of the resin, and the sheet body and the concavo-convex mold are separated by a predetermined distance in a state where the resin layer and the concavo-convex mold are partially bonded. Thereby, the height of the concavo-convex shape formed in the resin layer can be increased from the height of the concavo-convex shape of the concavo-convex shape. That is, even if a concavo-convex mold in which the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern is less than the required level is used, the concavo-convex sheet that satisfies the required level of the aspect ratio between the concavo-convex pattern and the pitch of the fine concavo-convex pattern can be manufactured.

  After increasing the height of the concavo-convex shape formed in the resin layer, the resin layer is cooled and cured so as to be equal to or lower than the glass transition temperature Tg of the resin, and the sheet-like body is separated from the concavo-convex mold. By molding, the desired uneven sheet can be obtained. This cooling includes not only active cooling such as air blow, but also passive cooling such as natural cooling.

  In the present invention, various shapes can be adopted as the irregularities on the surface of the sheet-like body. For example, if a flat lens shape such as a lenticular lens or a fly-eye lens is used, preferable optical characteristics can be obtained. In particular, it is preferable that the irregularities on the surface of the sheet-like body have a cone shape. If it is such a cone-shaped unevenness | corrugation, a preferable characteristic will be acquired as an uneven | corrugated shaped sheet | seat which has an antireflection effect etc.

  Here, the “cone” is a curved surface (or several planes) formed by a straight line connecting a point that goes around the circumference of a closed curve (or a broken line) on a plane and a fixed point outside the plane. A part of the space surrounded by (part), and a cone and a pyramid are typical. In addition, in the present invention, a cone having a parabolic shape and a hyperbolic shape can be adopted.

  Further, in the present invention, an adhesive layer is provided on the surface of the sheet-like body before forming the resin layer, silane coupling agent treatment, ozone treatment, corona discharge treatment, plasma treatment are performed. And it is preferable to perform 1 or more of the processes which perform an ultraviolet irradiation process. By performing such a treatment, the adhesive force between the resin layer and the sheet-like body is improved, which is preferable as an uneven sheet.

  Moreover, in this invention, it is preferable to perform a mold release process to the surface of the said uneven | corrugated type | mold. Thus, the shape of the fine concavo-convex pattern can be satisfactorily maintained by performing the mold release treatment on the surface of the concavo-convex mold.

  As described above, according to the present invention, in the method for producing a concavo-convex sheet in which concavo-convex concavo-convex is transferred and formed on substantially the entire surface of the sheet-like body, the height of the concavo-convex shape formed in the resin layer is increased. It can be increased from the height of the concavo-convex shape of the concavo-convex type, and even if a concavo-convex mold having a concavo-convex aspect ratio of the fine concavo-convex pattern less than the required level is used, the aspect ratio of the concavo-convex pattern of the fine concavo-convex pattern to the pitch Can produce an uneven sheet satisfying the required level.

  Hereinafter, an example of an embodiment of the present invention (first embodiment) will be described with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing each step of a method for producing an uneven sheet applied to the present invention. FIG. 2 is a schematic cross-sectional view showing steps unique to the method for producing a concavo-convex sheet according to the present invention.

  FIG. 1A is a schematic cross-sectional view of an embossing mold 10 that is a concavo-convex mold used in the present invention and a sheet-like body 12. A resin layer of the photopolymerizable resin 14 is formed on the surface of the sheet-like body 12.

  When the regular irregularities on the surface of the concave-convex sheet to be a product have a shape in which quadrangular pyramids are densely arranged in the XY direction, the regular irregularities on the surface of the embossing mold 10 are inverted shapes thereof. . The pitch in the XY direction of the irregularities on the surface of the embossing mold 10 is preferably 380 to 780 nm or less, which is the wavelength of visible light. The aspect ratio between the concavo-convex pattern and the pitch is preferably large. However, when it is difficult to produce a large aspect ratio, the height of the concavo-convex shape formed on the resin layer according to the present invention is set to An appropriate aspect ratio can be obtained as long as the step of increasing the height of the uneven shape can be applied.

  As a method of forming regular irregularities on the surface of the embossing mold 10, a method of directly forming irregularities on the surface of a plate-like body that is a material by photo etching, electron beam drawing, laser processing, etc. can be adopted. It is also possible to adopt a method in which irregularities are directly formed on the surface of a material that is easier to process than the plate-like body by photo etching, electron beam drawing, laser processing, stereolithography, etc., and an inverted mold of this shape is formed by electroforming, etc. . In particular, when the reversal mold is formed by electroforming or the like, a plurality of emboss molds (stampers) having the same shape can be obtained from one master (mother).

  It is preferable to perform a mold release process on the surface of the embossing mold 10. Thus, the shape of the fine concavo-convex pattern can be satisfactorily maintained by performing the mold release process on the surface of the embossing mold 10. As the mold release treatment, various known methods such as coating treatment with a fluororesin can be employed.

  As the sheet-like body 12, a resin film, paper (resin coated paper, synthetic paper, etc.), metal foil (aluminum web, etc.), etc. can be used. Resin film materials include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, polycarbonate, polyamide, PET (polyethylene terephthalate), biaxially stretched polyethylene terephthalate, polyethylene naphthalate, and polyamideimide. Known materials such as polyimide, aromatic polyamide, cellulose triacetate, cellulose acetate propionate, and cellulose diacetate can be used.

  As the characteristics of the sheet-like body 12, those having little elongation due to tension and those having little elongation due to heat, such that there is no stretching when the sheet-like body 12 is released from the embossing mold 10 are preferable. In the case of this embodiment in which the step of irradiating the resin layer with light is employed, a transparent or translucent material having a high light transmittance is preferable.

  In the case where continuous processing is performed with a roll mold in which regular unevenness is formed on the surface of the roll without using the plate-like emboss mold 10 as in this embodiment, the width of the sheet-like body 12 is as follows. In general, 0.1 to 3 m is generally used as the length of the sheet-like body 12, and 1000 to 100,000 m is generally employed, and the thickness of the sheet-like body 12 is generally employed from 0.5 to 200 μm. However, application of other sizes is not impeded.

  These sheet-like bodies 12 may be previously subjected to corona discharge, plasma treatment, easy adhesion treatment, heat treatment, dust removal treatment and the like. The surface roughness Ra of the sheet-like body 12 is preferably 3 to 10 nm at a cutoff value of 0.25 mm.

  In addition, the sheet-like body 12 may be one in which a base layer such as an adhesive layer is provided in advance and dried and cured, or one in which another functional layer is formed in advance on the back surface.

  The photopolymerizable resin 14 includes a photopolymerizable monomer and a polymerization initiator. As the photopolymerizable resin 14, a known resin that is polymerized with an activation energy beam such as an ultraviolet ray or an electron beam can be used. The photopolymerizable monomer is composed of a compound having a polymerizable functional group such as a radical polymerizable unsaturated group or an epoxy group. The viscosity of the photopolymerizable resin 14 can be 1 to 2000 mPa · s in an uncured state, and preferably 20 to 100 mPa · s in an uncured state. Further, those which are easily plastically deformed at a degree of polymerization of about 70 to 80% and are difficult to deform in a complete polymerization state are preferred. Moreover, a thing with little shrinkage | contraction at the time of hardening is preferable.

  Various known methods can be adopted as a method for forming the resin layer of the photopolymerizable resin 14 on the surface of the sheet-like body 12. Examples of such methods include a roller coating method, a gravure coating method, a roller coating plus doctor method, an extrusion type coating method, a slide coating method, a spin coating method, a printing method (screen printing method, etc.), a dip coating method, and the like. It is done.

  As the coating thickness of the resin layer of the photopolymerizable resin 14, the regular uneven shape of the surface of the uneven sheet as a product, the material of the photopolymerizable resin 14, the viscosity of the photopolymerizable resin 14, the photopolymerizable resin Although an appropriate value can be selected according to the method of forming the 14 resin layers, a value of 0.1 to 100 μm, preferably a value of 1 to 40 μm, more preferably a value of 0.1 to 20 μm can be adopted. .

  Next, the resin layer of the sheet-like body 12 is brought into close contact with the embossing mold 10, and the resin layer is imitated with the concavo-convex shape of the embossing mold 10, and the resin layer is irradiated with light. A process for generating an adhesive force with the mold 10 will be described with reference to FIG. The figure shows a state in which the embossing mold 10 shown in FIG. 1A is turned upside down and brought into close contact with the sheet-like body 12. Moreover, the arrow of the figure shows the irradiation light 16.

  In the step of making the resin layer follow the uneven shape of the embossing mold 10, it is preferable to devise so as not to generate bubbles between the resin layer and the embossing mold 10. For example, an appropriate method such as a method in which the resin layer and the embossing die 10 are brought into close contact under a reduced pressure atmosphere or a method in which the embossing die 10 is gradually brought into close contact from one end of the sheet-like body 12 can be adopted.

  As the irradiation light 16, active energy rays such as ultraviolet rays and electron beams can be adopted. The irradiation light 16 shown in FIG. 1B passes through the sheet-like body 12 and is applied to the resin layer of the photopolymerizable resin 14. However, when the sheet-like body 12 is not transparent or semi-transparent with high light transmittance, the embossing mold 10 is formed of a transparent or semi-transparent material and passes through the embossing mold 10 to transmit the photopolymerizable resin 14. It is also possible to irradiate the resin layer with irradiation light 16.

  By the irradiation of the irradiation light 16, the polymerization of the resin layer of the photopolymerizable resin 14 proceeds, and an adhesive force is generated between the resin layer and the embossing mold 10. However, if the resin layer of the photopolymerizable resin 14 is completely polymerized, the uneven shape of the resin layer cannot be deformed thereafter, so that the photopolymerizable resin 14 is in a semi-polymerized state, for example, completely It is necessary to keep the degree of polymerization at about 70 to 80% of the polymerization state.

  Next, in a state where the resin layer and the embossing mold 10 are partially bonded, the sheet-like body 12 and the embossing mold 10 are separated by a predetermined distance, and the height of the uneven shape formed on the resin layer is set to the height of the embossing mold 10. The process of increasing the height of the uneven shape will be described with reference to FIG.

  (B1) in FIG. 2 shows a state in which the resin layer of the photopolymerizable resin 14 is in a semi-polymerized state by the irradiation of the irradiation light 16, and an adhesive force is generated between the resin layer and the embossing mold 10. . (B2) in FIG. 2 shows that in this state, the sheet-like body 12 and the embossing mold 10 are separated by a predetermined distance, and the height of the concavo-convex shape formed on the resin layer is made larger than the height of the concavo-convex shape of the embossing mold 10. It shows the state. The arrows in the figure indicate the direction in which the height of the concavo-convex shape increases.

  (B3) in FIG. 2 and (C) in FIG. 1 show a state in which the sheet-like body 12 and the embossing mold 10 are further separated and completely separated. Thereby, the height of the concavo-convex shape formed in the resin layer can be increased from the height of the concavo-convex shape of the embossing mold 10. That is, even when the embossing mold 10 in which the aspect ratio between the unevenness of the fine unevenness pattern and the pitch is less than the required level is used, an uneven sheet that satisfies the required level of the aspect ratio between the unevenness of the fine unevenness pattern and the pitch can be manufactured. .

  Further, when the method of the present invention is carried out using the embossing mold 10 in which the aspect ratio between the unevenness of the fine unevenness pattern and the pitch does not satisfy the required level, the following effects are also obtained. When the aspect ratio between the unevenness and the pitch of the fine uneven pattern is small, the photopolymerizable resin 14 easily enters the bottom of the fine uneven pattern of the emboss mold 10. Therefore, the shape transferability is improved. In addition, the contact area between the fine concavo-convex pattern of the embossing mold 10 and the photopolymerizable resin 14 is smaller than when the aspect ratio is large. Therefore, the adhesion between the fine uneven pattern of the embossing mold 10 and the photopolymerizable resin 14 is also reduced, and cohesive failure does not easily occur inside the photopolymerizable resin 14 at the time of peeling. As a result, the shape stability of the fine concavo-convex pattern on the surface of the sheet-like body 12 is improved.

  Next, the process of applying light irradiation to the resin layer and polymerizing the resin layer will be described with reference to FIG. In a state where a desired fine uneven pattern is formed on the surface of the sheet-like body 12, light irradiation is further performed, and this resin layer is completely polymerized and cured. In this step, a method of irradiating light from the back surface of the sheet-like body 12 without irradiating light from the surface of the sheet-like body 12 as shown in the drawing can also be adopted. The concavo-convex sheet is thus completed.

  When shifting from (B2) to (B3) in FIG. 2, depending on the conditions, the adhesion between the embossing mold 10 and the photopolymerizable resin 14 varies within the surface of the sheet-like body 12, and peeling occurs. The height of the uneven pattern on the surface of the subsequent sheet-like body 12 may vary. In that case, in the state of (B2) in FIG. 2, the resin layer is irradiated with light, and the polymerization of the resin layer is allowed to proceed, thereby varying the height of the uneven pattern on the surface of the sheet-like body 12 after peeling. Can be prevented.

  Next, an example (second embodiment) of another embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected about the same and similar member in a 1st embodiment, and the description is abbreviate | omitted. Also in this embodiment, a photopolymerizable resin is used for the resin layer as in the first embodiment. 1A and 1B, the step of forming a resin layer of the photopolymerizable resin 14 on the surface of the sheet-like body 12, and the resin layer of the sheet-like body 12 are in close contact with the embossing mold 10 Thus, the process up to the step of making the resin layer follow the uneven shape of the embossing mold 10 is the same as that of the first embodiment.

  Next, the resin layer is irradiated with light to polymerize the resin layer, and an adhesive force is generated between the resin layer and the embossing mold 10. In this step, unlike the first embodiment, the resin layer is completely polymerized by light irradiation. Therefore, even if an adhesive force is generated between the resin layer and the embossing mold 10, the height of the concavo-convex shape formed on the resin layer by separating the sheet-like body 12 and the embossing mold 10 by a predetermined distance in this state. Cannot be increased beyond the height of the concavo-convex shape of the embossing die 10.

  Therefore, in the next step, the resin layer is heated so as to be equal to or higher than the glass transition temperature Tg of the resin. Thereby, plastic deformation of the resin layer becomes possible. In the next step, the sheet-like body 12 and the embossing mold 10 are separated by a predetermined distance, and the height of the concavo-convex shape formed on the resin layer is increased from the height of the concavo-convex shape of the embossing mold 10. The above process is the same as the state shown in (B1) and (B2) of FIG.

  In the next step, the resin layer is cooled so as to be equal to or lower than the glass transition temperature Tg of the resin. This step may be performed in a state shown in (B2) of FIG. 2 or may be performed in a state after peeling as shown in (B3) of FIG. The concavo-convex sheet is thus completed. According to this embodiment, the same effect as that of the first embodiment described above can be obtained.

  Next, another example (third embodiment) of the present invention will be described. In addition, the same code | symbol is attached | subjected about the same and similar member in a 1st embodiment, and the description is abbreviate | omitted. In this embodiment, unlike the first and second embodiments, a thermoplastic resin is used for the resin layer. 1A and 1B, a step of forming a resin layer of a thermoplastic resin on the surface of the sheet-like body 12, and a resin layer of the sheet-like body 12 are brought into close contact with the embossing mold 10. The process of making this resin layer follow the uneven shape of the embossing mold 10 is apparently the same as that of the first embodiment, but the conditions are quite different.

  Examples of the thermoplastic resin include various known plastics such as polyethylene, polypropylene, and polystyrene as hydrocarbon plastics, and polyvinyl chloride, polyvinyl acetate, polymethyl methacrylate, and ABS resins as polar vinyl plastics. Examples of the linear structural plastic include polyacetal, polyamide, and polycarbonate, and examples of the cellulose-based plastic include cellulose acetate and celluloid cellophane.

  However, in the present invention, the glass transition temperature Tg of the thermoplastic resin is required to be lower than the glass transition temperature Tg of the sheet-like body 12. Otherwise, when the thermoplastic resin is heated, the sheet-like body 12 is deformed and a good product cannot be obtained.

  In the step of forming the resin layer of the thermoplastic resin on the surface of the sheet-like body 12, it is preferable to heat the thermoplastic resin to form the resin layer with a predetermined uniform film thickness. In addition, the resin layer of the sheet-like body 12 is brought into close contact with the embossing mold 10, and the resin layer is made to follow the uneven shape of the embossing mold 10, and an adhesive force is generated between the resin layer and the embossing mold 10. In the step, it is preferable to heat the thermoplastic resin so that the resin layer follows the fine uneven shape of the embossing mold 10. At this time, it is preferable to apply a predetermined pressure to bring the resin layer of the sheet-like body 12 and the embossing mold 10 into close contact.

  Next, while maintaining the resin layer in a state near the glass transition temperature Tg of the resin, the sheet-like body 12 and the embossing die 10 are bonded to each other in a state where the resin layer and the embossing die 10 are partially bonded. The height of the concavo-convex shape formed on the resin layer is increased by a distance from the height of the concavo-convex shape of the embossing mold 10. That is, by maintaining the resin layer in the vicinity of the glass transition temperature Tg of the resin, the resin layer can be plastically deformed. The above process is the same as the state shown in (B1) and (B2) of FIG.

  In the next step, the resin layer is cooled so as to be equal to or lower than the glass transition temperature Tg of the resin. This step may be performed in the state shown in (B2) of FIG. 2, or may be performed in the state after peeling as shown in (B3) of FIG. The concavo-convex sheet is thus completed. Also according to this embodiment, the same effects as those of the first and second embodiments described above can be obtained.

  As mentioned above, although the example of embodiment of the manufacturing method of the uneven | corrugated sheet | seat which concerns on this invention was demonstrated, this invention is not limited to the example of the said embodiment, Various aspects can be taken.

  For example, in the example of the present embodiment, an embodiment in which the plate-like embossing mold 10 is used as the concavo-convex mold is employed. However, the roll mold in which regular irregularities are formed on the roll surface, or the belt surface is regular. A mode of performing semi-continuous processing of continuous processing or intermittent feeding by an endless belt type in which irregularities are formed may be employed.

  Next, examples of the present invention will be described in comparison with comparative examples. The first embodiment described above was adopted as an example of the present invention. The regular unevenness on the surface of the uneven sheet to be evaluated has a shape in which cones are densely arranged in the XY direction, and the regular unevenness on the surface of the embossing mold 10 is an inverted shape of this. The pitch of the unevenness on the surface of the embossing mold 10 in the XY direction was 200 nm, and the aspect ratio between the unevenness and the pitch of the uneven pattern was about 1.0. That is, the diameter of the bottom circle of the cone is 200 nm, and the height of the cone is about 200 nm. The material of the embossing die 10 is nickel electroforming, and the overall size of the embossing die 10 is 50 mm square.

  As the sheet-like body 12, a PET film having a thickness of 180 μm was used. The size was slightly larger than the 50 mm square in consideration of the gripping cost and the like. After the surface of the sheet-like body 12 was subjected to adhesion treatment, an ultraviolet curable resin as the photopolymerizable resin 14 was applied to a thickness of 40 μm using a bar coater.

The embossing mold 10 and the sheet-like body 12 are fixed to a stage of Tensilon (universal material testing machine) while facing each other, and one stage is moved to bring the embossing mold 10 and the sheet-like body 12 into close contact with each other. . In this state, ultraviolet rays were irradiated from the back surface of the sheet-like body 12. Irradiation with ultraviolet rays was performed for 2 minutes with a mercury lamp (manufactured by Oak Seisakusho, product name: Handy UV-300, output: 300 W). The irradiation intensity is 300 W / cm ² .

  Then, one stage was moved and the embossing type | mold 10 and the sheet-like body 12 were spaced apart. The moving speed of the stage at this time was 0.5 m / min.

  After the sheet-like body 12 was completely peeled from the embossing mold 10, ultraviolet rays were irradiated from the back surface of the sheet-like body 12. The ultraviolet irradiation was performed for 1 minute with the same mercury lamp.

  The sheet-like body 12 on which the concavo-convex pattern was formed was cut, and cross-sectional shapes at a plurality of locations of the concavo-convex pattern were measured with an SEM (scanning electron microscope), and the aspect ratio between the concavo-convex pattern and the pitch was calculated. As a result, the aspect ratio was in the range of 1.5 to 2.0.

  As a comparative example, the same material (embossing mold 10, sheet-like body 12, ultraviolet curable resin) and the same apparatus (Tensilon, mercury lamp) were used. And the process until it apply | coats an ultraviolet curable resin to the sheet-like body 12 was implemented similarly to the Example.

The embossing mold 10 and the sheet-like body 12 were fixed to a stage of Tensilon (universal material testing machine) while facing each other, and one of the stages was moved to bring the embossing mold 10 and the sheet-like body 12 into close contact. In this state, ultraviolet rays were irradiated from the back surface of the sheet-like body 12. The ultraviolet irradiation was performed for 3 minutes using the same mercury lamp as in the example. The irradiation intensity is 300 W / cm ² .

  Thereafter, one of the stages was moved and separated until the embossing mold 10 and the sheet-like body 12 were completely peeled off.

  The sheet-like body 12 on which the concavo-convex pattern was formed was cut, and cross-sectional shapes at a plurality of locations of the concavo-convex pattern were measured with an SEM (scanning electron microscope), and the aspect ratio between the concavo-convex pattern and the pitch was calculated. As a result, the aspect ratio was about 1.0.

  From the above results, the effect of the present invention was confirmed.

The schematic sectional drawing which shows each process of the manufacturing method of the uneven | corrugated sheet | seat applied to this invention The schematic sectional drawing which shows the process peculiar to the manufacturing method of the uneven | corrugated sheet | seat based on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Embossing type | mold, 12 ... Sheet-like body, 14 ... Photopolymerizable resin, 16 ... Irradiation light

Claims (6)

In the method for producing a concavo-convex sheet that transfers and forms concavo-convex irregularities on substantially the entire surface of the sheet-like body,
Forming a resin layer of a photopolymerizable resin on the surface of the sheet-like body;
A step of closely adhering the resin layer of the sheet-like body to the concavo-convex mold, and imitating the concavo-convex shape of the concavo-convex mold;
Subjecting the resin layer to light irradiation and generating an adhesive force between the resin layer and the concave-convex mold;
In a state where the resin layer and the concavo-convex mold are partially adhered, the sheet-like body and the concavo-convex mold are separated from each other by a predetermined distance, and the height of the concavo-convex shape formed on the resin layer is determined. Increasing the height of the shape,
Subjecting the resin layer to light irradiation and polymerizing the resin layer;
The manufacturing method of the uneven | corrugated shaped sheet | seat characterized by including this. In the method for producing a concavo-convex sheet that transfers and forms concavo-convex irregularities on substantially the entire surface of the sheet-like body,
Forming a resin layer of a photopolymerizable resin on the surface of the sheet-like body;
A step of closely adhering the resin layer of the sheet-like body to the concavo-convex mold, and imitating the concavo-convex shape of the concavo-convex mold;
Irradiating the resin layer with light, polymerizing the resin layer, and generating an adhesive force between the resin layer and the concave-convex mold;
Heating the resin layer so that the glass transition temperature Tg of the resin is equal to or higher;
In a state where the resin layer and the concavo-convex mold are partially adhered, the sheet-like body and the concavo-convex mold are separated from each other by a predetermined distance, and the height of the concavo-convex shape formed on the resin layer is determined. Increasing the height of the shape,
A step of cooling the resin layer so as to be equal to or lower than the glass transition temperature Tg of the resin;
The manufacturing method of the uneven | corrugated shaped sheet | seat characterized by including this. In the method for producing a concavo-convex sheet that transfers and forms concavo-convex irregularities on substantially the entire surface of the sheet-like body,
Forming a thermoplastic resin layer on the surface of the sheet-like body;
A step of bringing the resin layer of the sheet-like body into close contact with the concavo-convex mold, causing the resin layer to follow the concavo-convex shape of the concavo-convex mold, and generating an adhesive force between the resin layer and the concavo-convex mold; ,
While maintaining the resin layer in a state near the glass transition temperature Tg of the resin, the sheet-like body and the concavo-convex mold are separated by a predetermined distance in a state where the resin layer and the concavo-convex mold are partially bonded. And increasing the height of the concavo-convex shape formed in the resin layer from the height of the concavo-convex shape of the concavo-convex type,
A step of cooling the resin layer so as to be equal to or lower than the glass transition temperature Tg of the resin;
The manufacturing method of the uneven | corrugated shaped sheet | seat characterized by including this.   The method for producing a concavo-convex sheet according to any one of claims 1 to 3, wherein the irregularities on the surface of the sheet-like body are conical.   An adhesive layer is provided on the surface of the sheet-like body before forming the resin layer, a silane coupling agent treatment, an ozone treatment, a corona discharge treatment, a plasma treatment, and an ultraviolet irradiation treatment are performed. The manufacturing method of the uneven | corrugated sheet | seat of any one of Claims 1-4 which performs 1 or more among the processes to apply.   The manufacturing method of the uneven | corrugated sheet | seat of any one of Claims 1-5 which performs a mold release process on the surface of the said uneven | corrugated type | mold.

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