JP2007083447A - Method and apparatus for manufacturing uneven sheet - Google Patents

Abstract

An uneven sheet having a regular fine uneven pattern formed on its surface is manufactured with high quality without defects and high productivity with high line speed.
A method for producing a concavo-convex sheet in which the concavo-convex surface of an embossing roller 13 is transferred and formed on the surface of a belt-like flexible sheet W. By applying the resin liquid diluted with the organic solvent, the sheet on which the resin liquid layer is formed is continuously run, the organic solvent contained in the resin liquid layer is dried, and the dried sheet is It is wound around a rotating embossing roller, the unevenness on the surface of the embossing roller is transferred to the resin liquid layer, and the resin liquid layer is cured in a state where the sheet is wound around the embossing roller.
[Selection] Figure 1

Description

  The present invention relates to a method and apparatus for producing a concavo-convex sheet, in particular, a sheet-like material such as an embossed sheet having an antireflection effect in which a regular fine concavo-convex pattern is formed on the surface, with high quality without defects, In addition, the present invention relates to a method and apparatus for manufacturing a concavo-convex sheet suitable for manufacturing with high line speed and high productivity.

  In recent years, an embossed sheet having an antireflection effect has been adopted for use in electronic displays such as liquid crystals. In addition, flat lenses such as lenticular lenses and fly-eye lenses, embossed sheets such as light diffusion sheets, brightness enhancement sheets, optical waveguide sheets, and prism sheets are used. As such an embossed sheet, a sheet having a regular fine concavo-convex pattern formed on the surface has been conventionally known. Various methods are conventionally known as a method for forming such a regular fine uneven pattern (see Patent Documents 1 to 6).

  For example, in an apparatus configured as shown in FIG. 6, a resin is applied to the surface of the stamper roller 1 having a regular uneven pattern formed on the surface by the applying means 2, and the continuously running sheet 3 is applied to the stamper roller. 1 and the nip roller 4, the resin of the stamper roller 1 is in contact with the sheet 3, the resin is irradiated with ionizing radiation and cured, and then the sheet 3 is wound around the release roller 5 and peeled off from the stamper roller 1. The content to be made is disclosed (see Patent Documents 1 to 3).

Further, in the apparatus configured as shown in FIG. 7, a resin is applied in advance to the surface of the continuously running sheet 3, and this sheet 3 is connected to the stamper roller 1 on which a regular uneven pattern is formed. Content that is sandwiched between the nip rollers 4 and the uneven pattern of the stamper roller 1 is transferred to the resin, and is irradiated with ionizing radiation to be cured. Is disclosed (see Patent Documents 3 and 4).
Japanese Patent No. 2533379 Japanese Patent No. 2891344 JP-A-11-300768 JP 2000-141481 A JP 2002-333508 A Japanese Patent No. 32186662

  However, when trying to improve the productivity by increasing the line speed, there are problems such as the occurrence of coating streaks and the resin solution does not sufficiently spread on the roller, making it difficult to form a resin solution layer uniformly. .

  Furthermore, in recent years, it has been desired to increase the refractive index of optical resin layers for reasons of optical design. For example, in the case of a Fresnel lens, as the refractive index of the optical resin layer is increased, the lens pattern can be made shallower, release from the mold becomes easier, and productivity can be improved.

  Also, for example, in the case of a prism sheet for improving the front brightness of a backlight unit used in a liquid crystal display device or the like, when the apex angle of the prism is designed to be the same, the front brightness increases as the refractive index of the optical resin layer increases. Can be improved.

  On the other hand, in order to achieve such a high refractive index of the optical resin layer, it is necessary to use a compound containing a large amount of an aromatic ring structure or a halogen compound such as bromine as the curable composition. However, in general, such compounds are highly viscous liquids or solids. Accordingly, since the resin liquid also has a high viscosity, when manufactured by the method as described above, there is a problem that the applicability is further deteriorated, it is difficult to increase the line speed, and it is difficult to improve the productivity. .

  The present invention has been made in view of such circumstances, and is used to manufacture a concavo-convex sheet having a regular fine concavo-convex pattern formed on the surface with high quality and high productivity without defects. It is an object of the present invention to provide a method and apparatus for producing a concavo-convex sheet suitable for the above.

  In order to achieve the above object, the present invention provides a method for producing a concavo-convex sheet in which the concavo-convex surface of the concavo-convex roller is transferred and formed on the surface of the sheet-like body by applying a resin liquid diluted with an organic solvent. The belt-like flexible sheet-like body having a resin liquid layer formed on its surface is continuously run, the organic solvent contained in the resin liquid layer is dried, and the sheet-like body after drying is rotated with the irregularities. An uneven shape characterized in that it is wound around a roller, the unevenness on the surface of the uneven roller is transferred to the resin liquid layer, and the resin liquid layer is cured while the sheet-like body is wound around the uneven roller. A method for manufacturing a sheet is provided.

  To this end, the present invention provides a sheet-like body supply means for feeding out a belt-like flexible sheet-like body, a coating means for applying a resin liquid diluted with an organic solvent to the surface of the sheet-like body, The unevenness of the uneven roller surface is transferred and formed on the surface of the sheet-like body while the drying means for drying the organic solvent contained in the resin liquid layer and the continuously running sheet-like body are wound around the rotating uneven roller. There is provided an apparatus for producing a concavo-convex sheet, comprising: a transfer unit; and a resin liquid curing unit that cures the resin liquid in a state where the sheet-like body is wound around the concavo-convex roller.

  According to the present invention, the resin solution can be diluted to the required low viscosity with an organic solvent, the wettability is improved, and the wet coating amount of the diluted portion can be increased with the organic solvent. A liquid resin layer can be uniformly formed on the sheet-like body without surface defects such as streaks and bubble failures.

  In addition, since the step of drying the organic solvent contained in the resin liquid layer is provided before the sheet-like body is wound around the uneven roller and cured, the added organic solvent remains after curing. There is no concern about product functionality deterioration or strength deterioration of the cured film. Similarly, there is no concern that the organic solvent is released during use of the product to generate a bad odor or adversely affect health.

  In addition, when the sheet-like body is wrapped around a concavo-convex roller and pressed, if the viscosity of the resin liquid is too low, it may be difficult to control the lens thickness (resin thickness) and a uniform lens with a certain thickness may not be formed. As described above, since the organic solvent is removed by drying at the time of this embossing, the resin liquid has a sufficient viscosity, and there is no such concern.

  In this specification, the term “concave / convex roller” refers to a concave / convex pattern (embossed pattern on the surface of a belt-shaped body such as an endless belt as well as a concave / convex pattern on the surface of a cylindrical roller. In this case, even such a belt-like body acts in the same manner as a cylindrical embossing roller, and the same effect can be obtained.

  In the present invention, it is preferable that the resin liquid is a radiation curable resin liquid and the resin liquid layer is cured by irradiating the resin liquid layer with radiation. By using such a radiation curable resin liquid, curing of the resin is facilitated. Details of the radiation curable resin will be described later.

  In the present invention, in order to reduce the liquid viscosity, the resin liquid preferably contains 10% by weight or more of an organic solvent. Moreover, in this invention, it is preferable that the viscosity of the said resin liquid at the time of application | coating is 100 mPa * s or less. Since the resin liquid contains such an amount of the organic solvent and has such a low viscosity, the resin liquid layer can be uniformly formed on the sheet-like body without surface defects such as coating stripes and foam failure.

  In the present invention, the resin liquid is preferably applied by a die coater, a bar coater, a roll coater, or a gravure coater. Such a coating method is suitable for coating the resin of the present invention.

  In the present invention, the resin solution generates at least (A) a compound containing a polymerizable group of an acryloyl group and / or a vinyl group, and (B) an active species capable of polymerizing the compound (A) by irradiation with radiation. It is preferable that a compound is included. By using such a radiation curable resin liquid, curing of the resin is facilitated. The acroyl group includes a methacryloyl group.

  As described above, according to the present invention, a concavo-convex sheet having a regular fine concavo-convex pattern formed on the surface can be produced with high quality and high productivity without defects and with high line speed.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing a configuration of an embossed sheet manufacturing apparatus 10 to which the present invention is applied. The embossed sheet manufacturing apparatus 10 includes a sheet-like body supplying unit 11, an applying unit 12, an embossing roller 13 that is a concavo-convex roller, a nip roller 14, a resin curing unit 15, a peeling roller 16, and a protective film supplying unit. 17 and sheet winding means 18, etc.

  The sheet supply means 11 which is a sheet-like body supply means is for sending out the sheet W which is a sheet-like body, and includes a delivery roll on which the sheet W is wound.

  The coating means 12 is a device that applies a radiation curable resin liquid to the surface of the sheet W, and includes a liquid supply source 12A that supplies the radiation curable resin liquid, a liquid supply device (liquid feed pump) 12B, a coating head 12C, It comprises a support roller 12D that wraps and supports the sheet W at the time of application, a pipe for supplying a radiation curable resin liquid from the liquid supply source 12A to the application head 12C, and the like. As the coating head 12C, a coating head of a die coater (extrusion type coater) is employed.

  As the drying means 19, various known systems can be adopted as long as the coating liquid applied to the sheet W can be uniformly dried, such as a tunnel-shaped drying apparatus shown in FIG. 1. . For example, a radiant heating method using a heater, a hot air circulation method, a far infrared method, a vacuum method, or the like can be employed.

  The embossing roller 13 is required to have an uneven pattern accuracy, mechanical strength, roundness, and the like that can transfer and form unevenness on the surface of the sheet W. Such an embossing roller 13 is preferably a metal roller.

  A regular fine uneven pattern is formed on the outer peripheral surface of the embossing roller 13. Such a regular fine concavo-convex pattern is required to have a shape obtained by inverting the fine concavo-convex pattern on the surface of an embossed sheet as a product.

  As an embossed sheet as a product, for example, a lenticular lens in which fine concavo-convex patterns are arranged two-dimensionally, or a fine cone such as a fly-eye lens, cone, or pyramid in which fine concavo-convex patterns are arranged three-dimensionally in the XY direction A flat lens or the like laid on the surface is an object, and a regular fine uneven pattern on the outer peripheral surface of the embossing roller 13 is made to correspond to this.

  As a method for forming a regular fine concavo-convex pattern on the outer peripheral surface of the embossing roller 13, a method of cutting the surface of the embossing roller 13 with a diamond bit (single point), photo-etching, electron beam drawing on the surface of the embossing roller 13, The method of forming irregularities directly by laser processing etc. can be adopted, and irregularities are formed on the surface of thin metal plate by photo etching, electron beam drawing, laser processing, stereolithography, etc. Can be wound around and fixed to the embossing roller 13.

  In addition, uneven surfaces are formed on the surface of materials that are easier to process than metal by photo-etching, electron beam drawing, laser processing, stereolithography, etc., and a reversal of this shape is formed by electroforming etc. to make a thin metal plate It is also possible to adopt a method in which an embossing roller 13 is formed by creating a body and winding and fixing the plate-like body around the roller. In particular, when the inversion mold is formed by electroforming or the like, there is a feature that a plurality of plate-like bodies 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 roller 13. 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 roller 13. As the mold release treatment, various known methods such as coating treatment with a fluororesin can be employed. The embossing roller 13 is preferably provided with driving means. The embossing roller 13 rotates counterclockwise (CCW) as shown in the figure.

  The nip roller 14 forms a roller while pressing the sheet W while being paired with the embossing roller 13, and is required to have predetermined mechanical strength, roundness, and the like. The longitudinal elastic modulus (Young's modulus) on the surface of the nip roller 14 is preferably set to an appropriate value according to the material and physical properties of the resin and the sheet W. The nip roller 14 is preferably provided with driving means. The nip roller 14 rotates in the clockwise direction (CW) as shown in the figure.

  In order to apply a predetermined pressing force between the embossing roller 13 and the nip roller 14, it is preferable to provide a pressing means on either the embossing roller 13 or the nip roller 14. Similarly, it is preferable to provide fine adjustment means on either the embossing roller 13 or the nip roller 14 so that the gap (clearance) between the embossing roller 13 and the nip roller 14 can be accurately controlled.

  The resin curing means 15 is a light irradiation means provided facing the embossing roller 13 on the downstream side of the nip roller 14. The resin curing means 15 transmits the sheet W by light irradiation and cures the resin liquid layer. The resin curing means 15 can irradiate light (radiation) having a wavelength corresponding to the curing characteristics of the resin, and according to the conveyance speed of the sheet W. It is preferable that a sufficient amount of radiation can be irradiated. As the resin curing means 15, for example, a columnar irradiation lamp having substantially the same length as the width of the sheet W can be adopted. Further, a plurality of the cylindrical irradiation lamps can be provided in parallel, and a reflector can be provided on the back surface of the cylindrical irradiation lamp.

  The peeling roller 16 is paired with the embossing roller 13 to peel the sheet W from the embossing roller 13 and is required to have predetermined mechanical strength, roundness, and the like. The sheet W is peeled off from the embossing roller 13 and wound around the peeling roller 16 while being sandwiched between the rotating embossing roller 13 and the peeling roller 16 at the peeling portion. In order to ensure this operation, the peeling roller 16 is preferably provided with a driving means. The peeling roller 16 rotates in the clockwise direction (CW) as shown in the figure.

  When the temperature of the resin or the like rises due to curing, a configuration in which cooling means such as passing cold water through the peeling roller 16 is employed to cool the sheet W at the time of peeling to ensure peeling. it can.

  Although not shown, a plurality of backup rollers are provided to face each other between the pressing location (9 o'clock position) of the embossing roller 13 and the peeling location (3 o'clock position). A configuration in which the curing process is performed while pressing the sheet W with the roller 13 can also be adopted.

  The sheet winding means 18 stores the peeled sheet W, and includes a winding roll that winds the sheet W or the like. In this sheet winding means 18, the protective film H supplied from the adjacent protective film supply means 17 is supplied to the surface of the sheet W, and is stored in the sheet winding means 18 in a state where both films overlap. The

  In the embossed sheet manufacturing apparatus 10, a guide roller or the like that forms a conveyance path of the sheet W may be provided between the coating unit 12 and the embossing roller 13, between the peeling roller 16 and the sheet winding unit 18, and the like. In addition, a tension roller or the like can be provided as needed to absorb slack during conveyance of the sheet W.

  Next, each material applied to the present invention will be described. As the sheet W, a resin film, paper (resin coated paper, synthetic paper, etc.), metal foil (aluminum web, etc.) and the like can be used. As the material of the resin film, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyester, polyolefin, acrylic, polystyrene, polycarbonate, polyamide, PET (polyethylene terephthalate), biaxially stretched polyethylene terephthalate, Known materials such as polyethylene naphthalate, polyamideimide, polyimide, aromatic polyamide, cellulose acylate, cellulose triacetate, cellulose acetate propionate, and cellulose diacetate can be used. Of these, polyester, cellulose acylate, acrylic, polycarbonate, and polyolefin can be preferably used.

  The sheet W generally has a width of 0.1 to 3 m, the sheet W has a length of 1000 to 100,000 m, and the sheet W has a thickness of 1 to 300 μm. However, application of other sizes is not impeded.

  These sheets W 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 W is preferably 3 to 10 nm at a cutoff value of 0.25 mm.

  The sheet W may be a sheet W provided with a base layer such as an adhesive layer in advance and dried and cured, or a sheet having another functional layer formed in advance on the back surface. Similarly, as the sheet W, not only a one-layer structure but also a structure having two or more layers can be adopted. Moreover, it is preferable that the sheet | seat W is a transparent body and translucent body which can permeate | transmit light.

  Resins that can be used in the present invention include a reactive group-containing compound such as a (meth) acryloyl group, a vinyl group, or an epoxy group, and a radical or cation that can react with the reactive group-containing compound by irradiation with ultraviolet rays or the like. Those containing compounds that generate active species can be used.

  In particular, from the viewpoint of curing speed, a combination of a reactive group-containing compound (monomer) containing an unsaturated group such as a (meth) acryloyl group or a vinyl group and a radical photopolymerization initiator that generates a radical by light is preferable. . Of these, (meth) acryloyl group-containing compounds such as (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate are preferable.

  As the (meth) acryloyl group-containing compound, a compound containing one or more (meth) acryloyl groups can be used. Moreover, the reactive group containing compound (monomer) containing unsaturated groups, such as said acryloyl group and a vinyl group, may be used independently or may be used in mixture of multiple types as needed.

  Examples of such (meth) acryloyl group-containing compounds include, for example, isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl as monofunctional monomers containing only one (meth) acryloyl group-containing compound. (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethyl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, Propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate , Heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate , Butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol ( Examples include meth) acrylate and methoxypolypropylene glycol (meth) acrylate.

  Furthermore, as a monofunctional monomer having an aromatic ring, phenoxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, 4-phenylphenoxyethyl (meth) acrylate, 3- (2-phenylphenyl) -2-hydroxypropyl (meth) acrylate, and p-cumylphenol reacted with ethylene oxide ( (Meth) acrylate, 2-bromophenoxyethyl (meth) acrylate, 4-bromophenoxyethyl (meth) acrylate, 2,4-dibromophenoxyethyl (meth) acrylate, 2,6-dibromophenoxyethyl (meth) ) Acrylate, 2,4,6-bromophenyl (meth) acrylate, 2,4,6-tribromophenoxyethyl (meth) acrylate.

  Examples of such commercially available aromatic monocyclic monocyclic monomers include Aronix M113, M110, M101, M102, M5700, TO-1317 (above, manufactured by Toagosei Co., Ltd.), Biscote # 192, # 193, # 220, 3BM (Osaka Organic Chemical Co., Ltd.), NK Ester AMP-10G, AMP-20G (Shin Nakamura Chemical Co., Ltd.), Light Acrylate PO-A, P-200A, Epoxy Ester M-600A, light ester PO (above, manufactured by Kyoeisha Chemical Co., Ltd.), New Frontier PHE, CEA, PHE-2, BR-30, BR-31, BR-31M, BR-32 (above, Daiichi Kogyo) Pharmaceutical Co., Ltd.).

  Examples of unsaturated monomers having two (meth) acryloyl groups in the molecule include alkyl diols such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, and 1,9-nonanediol diacrylate. Examples include polyalkylene glycol diacrylates such as diacrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol diacrylate, and tripropylene glycol diacrylate, neopentyl glycol di (meth) acrylate, and tricyclodecane methanol diacrylate.

  As unsaturated monomers having a bisphenol skeleton, ethylene oxide-added bisphenol A (meth) acrylic acid ester, ethylene oxide-added tetrabromobisphenol A (meth) acrylic acid ester, propylene oxide-added bisphenol A (meth) acrylic acid ester, propylene oxide-added Tetrabromobisphenol A (meth) acrylic acid ester, bisphenol A epoxy (meth) acrylate obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid, tetrabromobisphenol A diglycidyl ether and (meth) Tetrabromobisphenol A epoxy (meth) acrylate, bisphenol F diglycidyl ether and (meth) obtained by epoxy ring-opening reaction with acrylic acid Bisphenol F epoxy (meth) acrylate obtained by epoxy ring-opening reaction with crylic acid, tetrabromobisphenol F epoxy (meth) acrylate obtained by epoxy ring-opening reaction of tetrabromobisphenol F diglycidyl ether and (meth) acrylic acid Etc.

  Commercially available unsaturated monomers having such a structure include Biscote # 700 and # 540 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-208, M-210 (above, Toagosei Co., Ltd.) ), NK ester BPE-100, BPE-200, BPE-500, A-BPE-4 (above, Shin-Nakamura Chemical Co., Ltd.), light ester BP-4EA, BP-4PA, epoxy ester 3002M, 3002A 3000M, 3000A (above, manufactured by Kyoeisha Chemical Co., Ltd.), KAYARAD R-551, R-712 (above, manufactured by Nippon Kayaku Co., Ltd.), BPE-4, BPE-10, BR-42M (above, No. 1) Manufactured by Ichi Kogyo Seiyaku Co., Ltd.), Lipoxy VR-77, VR-60, VR-90, SP-1506, SP-1506, SP-1507, SP-1509, SP 1563 (manufactured by Showa High Polymer Co., Ltd.), NEOPOL V779, NEOPOL V779MA (manufactured by Japan U-PICA Co., Ltd.), and the like.

  Furthermore, as a trifunctional or higher functional (meth) acrylate unsaturated monomer, a trihydric or higher polyhydric alcohol (meth) acrylate such as trimethylolpropane litho (meth) acrylate, pentaerythritol tri (meth) acrylate or trimethylol. Propane trioxyethyl (meth) acrylate, tris (2-acryloyloxyethyl) isocyanurate, etc. are listed, and commercially available products include Aronix M305, M309, M310, M315, M320, M350, M360, M408 (and above, Toagosei) Made by Co., Ltd., Biscoat # 295, # 300, # 360, GPT, 3PA, # 400 (Osaka Organic Chemical Co., Ltd.), NK ester TMPT, A-TMPT, A-TMM-3, A- TMM-3L, A-TMMT (above, Shinnaka Chemical Co., Ltd.), Light Acrylate TMP-A, TMP-6EO-3A, PE-3A, PE-4A, DPE-6A (above, Kyoeisha Chemical Co., Ltd., KAYARAD PET-30, GPO-303, TMPTA) , TPA-320, DPHA, D-310, DPCA-20, DPCA-60 (manufactured by Nippon Kayaku Co., Ltd.) and the like.

  In addition, a urethane (meth) acrylate oligomer may be blended. Examples of urethane (meth) acrylates include polyether polyols such as polyethylene glycol and polytetramethyl glycol; succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, tetrahydro (anhydrous) phthalic acid, hexahydro (anhydrous) phthalic acid Obtained by reaction of a dibasic acid such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc. Polyester polyol, polyε-caprolactone-modified polyol; polymethylvalerolactone-modified polyol; ethylene glycol, propylene glycol, 1,4-butanediol, Alkyl polyols such as 1,6-hexanediol and neopentyl glycol; bisphenol A skeleton alkylene oxide modified polyols such as ethylene oxide-added bisphenol A and propylene oxide-added bisphenol A; bisphenol F skeleton alkylene such as ethylene oxide-added bisphenol F and propylene oxide-added bisphenol F Oxide-modified polyols or mixtures thereof and organic polyisocyanates such as tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, etc. Manufactured from hydroxy group-containing (meth) acrylate And urethane (meth) acrylate oligomers. A urethane (meth) acrylate oligomer is preferable for maintaining the viscosity of the curable composition of the present invention moderately.

  As commercially available monomers of these urethane (meth) acrylates, for example, Aronix M120, M-150, M-156, M-215, M-220, M-225, M-240, M-245, M-270 ( As mentioned above, manufactured by Toagosei Co., Ltd.), AIB, TBA, LA, LTA, STA, Viscoat # 155, IBXA, Viscoat # 158, # 190, # 150, # 320, HEA, HPA, Viscoat # 2000, # 2100, DMA, biscort # 195, # 230, # 260, # 215, # 335HP, # 310HP, # 310HG, # 312 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), Light Acrylate IAA, LA, SA , BO-A, EC-A, MTG-A, DMP-A, THF-A, IB-XA, HOA, HOP-A, HOA-M L, HOA-MPE, light acrylate 3EG-A, 4EG-A, 9EG-A, NP-A, 1,6HX-A, DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), KAYARADTC-110S, HDDA, NPGDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620 (Nippon Kayaku Co., Ltd.), FA-511A, 512A, 513A (Hitachi Chemical Co., Ltd.), VP (BASF) ACMO, DMAA, DMAPAA (manufactured by Kojin Co., Ltd.) and the like.

  The urethane (meth) acrylate oligomer is obtained as a reaction product of (a) hydroxy group-containing (meth) acrylate, (b) organic polyisocyanate and (c) polyol, but (a) hydroxy group-containing (meth). A reaction product obtained by reacting an acrylate with (b) an organic polyisocyanate and then (c) a polyol is preferable.

  The above unsaturated monomers may be used alone, or a plurality of types may be mixed as necessary.

  Examples of photo radical polymerization initiators include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl)- 2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethyl Oxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Examples thereof include bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, ethyl-2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, and the like.

  Commercially available radical photopolymerization initiators include, for example, Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI 1700, CGI 1750, CGI 11850, CG 24-61, Darocurl 116, 1173 (above, Ciba Specialty Chemicals ( Co., Ltd.), Lucirin LR8728, 8893X (manufactured by BASF), Ubekrill P36 (manufactured by UCB), KIP150 (manufactured by Lamberti), and the like. Among these, Lucirin LR8883X is preferable from the viewpoint of being liquid and easily dissolved and having high sensitivity.

  The radical photopolymerization initiator is preferably blended in the total composition in an amount of 0.01 to 10% by weight, particularly 0.5 to 7% by weight. The upper limit of the blending amount is preferably in this range from the viewpoints of the curing characteristics of the composition, the mechanical properties and optical characteristics of the cured product, handling, and the like, and the lower limit of the blending amount is preferably in the range of preventing a decrease in the curing rate.

  The composition of the present invention may further contain a photosensitizer. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, 4-dimethyl Examples include methyl aminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate and the like, and examples of commercially available products include Ubekryl P102, 103, 104, 105 (manufactured by UCB). .

  Further, in addition to the above components, various additives as necessary include, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants. Colorants, storage stabilizers, plasticizers, lubricants, solvents, fillers, anti-aging agents, wettability improvers, mold release agents, and the like can be blended as necessary.

  Here, examples of the antioxidant include Irganox 1010, 1035, 1076, 1222 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Antigen P, 3C, FR, GA-80 (manufactured by Sumitomo Chemical Co., Ltd.). Examples of the ultraviolet absorber include Tinuvin P, 234, 320, 326, 327, 328, 329, 213 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Seesorb 102, 103, 110, 501; 202, 712, 704 (above, manufactured by Sipro Kasei Co., Ltd.) and the like. Examples of the light stabilizer include Tinuvin 292, 144, 622LD (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), Sanol LS770 ( Sankyo Co., Ltd.), Sumisorb TM-0 1 (manufactured by Sumitomo Chemical Co., Ltd.) and the like. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, commercially available Examples of the product include SH6062, 6030 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), KBE903, 603, 403 (above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Examples include silicone additives such as dimethylsiloxane polyether and nonionic fluorosurfactants, and commercially available silicone additives include DC-57, DC-190 (above, manufactured by Dow Corning), SH-28PA, SH-29PA, SH-30PA, SH-190 (above, Toray Dow Corning Silicone Co., Ltd.), KF351, KF352, KF353, KF354 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), L-700, L-7002, L-7500, FK-024-90 (above, Nihon Unicar Co., Ltd.) )), And commercially available non-ionic fluorosurfactants include FC-430, FC-171 (above 3M), Megafac F-176, F-177, R-08, F780 (above Dainippon Ink Co., Ltd.) and the like, and the release agent includes Prisurf A208F (Daiichi Kogyo Seiyaku Co., Ltd.).

  The organic solvent for adjusting the viscosity of the resin liquid of the present invention may be any organic solvent that can be mixed without unevenness such as precipitates, phase separation, and cloudiness when mixed with the resin liquid. For example, acetone, methyl ethyl ketone, Examples thereof include methyl isobutyl ketone, ethanol, propanol, butanol, 2-methoxyethanol, cyclohexanol, cyclohexane, cyclohexanone, toluene, and the like.

  When an organic solvent is added, it is necessary to dry and evaporate the organic solvent during the manufacturing process of the product. However, if a large amount of residual solvent remains in the product, the mechanical properties of crystallization deteriorate. There is also a concern that the organic solvent evaporates and diffuses during use as a product, causing bad odor and adverse health effects. For this reason, organic solvents having a high boiling point are not preferable because the amount of residual solvent increases.

  However, if the boiling point is too low, it will evaporate violently, resulting in rough surface, condensation water adhering to the surface of the composition due to the heat of vaporization during drying, resulting in surface defects and vapor concentration. It becomes higher and the risk of ignition etc. increases.

  Therefore, the boiling point of the organic solvent is preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 70 ° C. or higher and 120 ° C. or lower. From the viewpoint of the solubility of the material and the boiling point, the organic solvent is preferably methyl ethyl ketone (bp. 79.6 ° C), 1-propanol (bp. 97.2 ° C) or the like.

  The amount of the organic solvent added to the resin solution of the present invention depends on the type of the solvent and the viscosity of the resin solution before the addition of the solvent. , 40% by weight or less, preferably 15% by weight or more and 30% by weight or less. If the amount of the organic solvent added is too small, the effect of reducing the viscosity and the effect of increasing the coating amount are small, and the coating property is not sufficiently improved.

  However, if the resin liquid is diluted too much, the viscosity is too low and the liquid flows on the sheet-like body to cause unevenness, or the liquid turns around the back surface of the sheet-like body. In addition, the drying process may not be sufficient, and a large amount of organic solvent may remain in the product, resulting in deterioration of product function, volatilization during product use, generation of bad odors, and adverse health effects. Occurs.

  The resin liquid of the present invention can be produced by mixing the above-mentioned components by a conventional method, and can be produced by heating and dissolving as necessary. The viscosity of the resin liquid thus prepared is usually 10 to 50000 mPa · s / 25 ° C.

  When the resin liquid is supplied to the sheet W or the embossing roller 13, if the viscosity is too high, it is difficult to supply the composition uniformly. When manufacturing a lens, uneven coating, undulation, and air bubbles are generated. For this reason, it becomes difficult to obtain the target lens thickness, and the lens performance cannot be fully exhibited.

  This tendency is particularly noticeable when the line speed is increased. Accordingly, in this case, the liquid viscosity is preferably low, preferably 5 to 100 mPa · s, and more preferably 10 to 50 mPa · s. Such a low viscosity can be adjusted by adding an appropriate amount of an organic solvent. Further, the viscosity can be adjusted by setting the temperature of the coating solution to be kept warm.

  On the other hand, if the viscosity after evaporation of the solvent is too low, it may be difficult to control the lens thickness when embossing with the embossing roller 13, and a uniform lens with a certain thickness may not be formed. A preferred viscosity is 5 to 3000 mPa · s. When an organic solvent is mixed, by providing a step of evaporating the organic solvent by heat drying or the like between the steps of supplying the resin solution and embossing with the embossing roller 13, the viscosity is low when the resin solution is supplied. Thus, when the embossing roller 13 is used for embossing, the organic solvent is dried and the embossing roller 13 can be uniformly embossed with a resin solution having a higher viscosity.

  In the case of a prism lens sheet, the cured product obtained by curing the resin liquid of the present invention with radiation particularly preferably has the following physical properties (refractive index, softening point).

  The refractive index is preferably 1.55 or more and more preferably 1.56 or more at 25 ° C. of the cured product. This is because when the refractive index at 25 ° C. of the cured product is less than 1.55, when a prism lens sheet is formed using this composition, sufficient front luminance may not be ensured.

  As a softening point, 40 degreeC or more is preferable and 50 degreeC or more is more preferable. This is because if the softening point is less than 40 ° C., the heat resistance may not be sufficient.

  Next, returning to FIG. 1, the operation of the embossed sheet manufacturing apparatus 10 will be described. The sheet W is sent out from the sheet-like body supply means 11 at a constant speed. The sheet W is fed into the application unit 12 and the resin liquid is applied to the surface of the sheet W. After the application, the resin liquid applied to the sheet W is dried by the drying means 19 and the solvent is evaporated. Next, the sheet W is fed into a forming unit composed of an embossing roller 13 and a nip roller 14. As a result, roller forming is performed while the continuously running sheet W is pressed by the rotating embossing roller 13 and the nip roller 14 at the 9 o'clock position of the embossing roller 13. That is, the sheet W is wound around the rotating embossing roller 13, and the unevenness on the surface of the embossing roller 13 is transferred to the resin layer.

  Next, in a state where the sheet W is wound around the embossing roller 13, the resin curing unit 15 transmits the sheet W and irradiates the resin liquid layer with radiation, thereby curing the resin liquid layer. Thereafter, the sheet W is peeled off from the embossing roller 13 by winding the sheet W around the peeling roller 16 at the 3 o'clock position of the embossing roller 13.

  In addition, although not shown in FIG. 1, in order to further accelerate hardening after peeling the sheet | seat W, radiation irradiation can also be performed again.

  The peeled sheet W is conveyed to the sheet take-up means 18 and the protective film H supplied from the protective film supply means 17 is supplied to the surface of the sheet W. It is wound up and stored by a winding roll.

  In this way, the resin layer is formed on the surface of the sheet W without unevenness, and further, the embossing by the embossing roller 13 is made stable and uniform. Thereby, the uneven | corrugated sheet | seat in which the regular fine uneven | corrugated pattern was formed in the surface can be manufactured with high quality without a defect.

  As mentioned above, although the example of embodiment of the manufacturing method and apparatus 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 aspect using the roller-shaped embossing roller 13 is adopted, but an aspect using an uneven pattern (embossed shape) formed on the surface of a belt-like body such as an endless belt may also be used. Can be adopted. This is because even such a belt-like body acts in the same manner as a cylindrical roller, and the same effect can be obtained.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Adjustment of resin liquid]
The compounds shown in the table of FIG. 2 were mixed at the stated weight ratio, heated to 50 ° C., dissolved by stirring, and resin solutions 1 to 3 were obtained. In addition, the name and content of each compound are as follows.

EB3700: Everkrill 3700, manufactured by Daicel UC Corporation,
Bisphenol A type epoxy acrylate,
(Viscosity: 2200 mPa · s / 65 ° C)
BPE200: NK ester BPE-200, manufactured by Shin-Nakamura Chemical Co., Ltd.
Ethylene oxide-added bisphenol A methacrylate,
(Viscosity: 590 mPa · s / 25 ° C)
BR-31: New Frontier BR-31, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
Tribromophenoxyethyl acrylate,
(Solid at normal temperature, melting point 50 ° C or higher)
LR8883X: Lucirin LR8883X, a north radical generator manufactured by BASF Corporation,
Ethyl-2,4,6-trimethylbenzoylethoxyphenyl osphine oxide MEK: methyl ethyl ketone [production of embossed sheet]
The embossed sheet was manufactured using the embossed sheet manufacturing apparatus 10 having the configuration shown in FIG.

  As the sheet W, a transparent PET (polyethylene terephthalate) film having a width of 500 mm and a thickness of 100 μm was used.

  As the embossing roller 13, a roller made of S45C having a length (width direction of the sheet W) of 700 mm and a diameter of 300 mm and having a surface material of nickel was used. Grooves with a pitch of 50 μm in the roller axial direction were formed on the entire circumference of the surface of the roller by cutting using a diamond tool (single point). The cross-sectional shape of the groove is a triangular shape with an apex angle of 90 degrees, and the bottom of the groove is a triangular shape with a 90 degree without a flat portion. That is, the groove width is 50 μm and the groove depth is about 25 μm. Since the groove is endless without a seam in the circumferential direction of the roller, the embossing roller 13 can form a lenticular lens (prism sheet) having a triangular cross section on the sheet W. The surface of the roller was plated with nickel after the grooves were processed. A schematic sectional view of the embossing roller 13 is shown in FIG.

  A die coater was used as the coating means 12. As the coating head 12C of the coating means 12, an extrusion type was used.

  As the coating solution F (resin solution), each solution described in the table of FIG. 2 was used. In addition, the sample of each Example and the comparative example was manufactured with the combination of the resin liquid and traveling speed which are shown in the table | surface of FIG. 4 mentioned later.

  The thickness of the coating solution F (resin solution) in the wet state is such that the supply amount of the coating solution F to the coating head 12C is a liquid supply device (liquid feed pump) 12B so that the film thickness after drying the organic solvent is 20 μm. Controlled by

  As the drying means 19, a hot air circulation type apparatus was used. The temperature of the hot air was set to 100 ° C.

  As the nip roller 14, a roller having a diameter of 200 mm and a silicon rubber layer having a rubber hardness of 90 formed on the surface thereof was used. The nip pressure (effective nip pressure) for pressing the sheet W by the embossing roller 13 and the nip roller 14 was 0.5 Pa.

A metal halide lamp was used as the resin curing means 15 and irradiation was performed with an energy of 1000 mJ / cm ² .

  As described above, a sheet W on which an uneven pattern corresponding to each of the examples and comparative examples shown in the table of FIG. 4 was obtained.

[Embossed shape evaluation]
The sheet W was cut, and the embossed shape was evaluated by measuring the cross-sectional shape at a plurality of locations of the concavo-convex pattern using an SEM (scanning electron microscope). A schematic cross-sectional shape of the sheet W (embossed sheet) is shown in FIG.

[Evaluation of cured film properties]
About each resin liquid, the cured film was created separately by the method as shown below, and the cured film physical property was measured.

[Measurement of refractive index]
The liquid curable composition was applied onto a glass plate using a spinner and dried in an oven set at 100 ° C. for 1 minute. This film was irradiated with ultraviolet rays having an intensity of 1000 mJ / cm ² under a nitrogen atmosphere to obtain a cured film. The refractive index of this cured film at 25 ° C. was measured using an Abbe refractometer.

[Measurement of Tg (Glass Transition Point)]
The liquid curable composition was applied onto a glass plate using a spinner and dried in an oven set at 100 ° C. for 1 minute. This film was irradiated with ultraviolet rays having an intensity of 1000 mJ / cm ² under a nitrogen atmosphere to obtain a cured film having a thickness of about 20 μm. The cured film on this glass plate was measured for pendulum viscoelasticity with a pendulum type viscoelasticity measuring instrument (Orientec Co., Ltd., model number: DDV-OPA) at a temperature rising mixing speed of 5 ° C / min, and logarithmic decay The temperature at which the curve shows the maximum value was defined as Tg.

  The principle of pendulum viscoelasticity measurement is described in general textbooks. For example, the Technical Information Association “Polymer / Thermophysical Properties Know-how Collection” 1st Edition, P287, “Rigid Pendulum Type Viscosity” It is described in the section of “Viscoelasticity evaluation of polymer composite material by elastic device”.

  Hereinafter, for each resin liquid, the results of producing embossed sheets by changing the traveling speed by the above manufacturing method are summarized in the table of FIG. Moreover, the refractive index and Tg were measured about each corresponding resin liquid based on said evaluation method. The results are also summarized in the table of FIG.

  In the production of the embossed sheet, the coating amount was adjusted so that the thickness of the embossed shape after solvent drying was the same. The evaluation of the emboss shape was made into a three-level evaluation of ◯, Δ, and X as shown in the margin of FIG.

  According to the table of FIG. 4, in each example and comparative example, although there was no difference in the evaluation results of the embossed shape, in the surface shape, each example was all good, while in comparison example 1 and No. 2 was bad.

  From the above results, by using a resin liquid diluted with an organic solvent, a concavo-convex sheet in which a regular fine concavo-convex pattern is formed on the surface without surface unevenness can be obtained with high quality without defects and also in cured film properties. The effect of the present invention was confirmed that it was possible to produce with high productivity at high line speed without any influence.

The conceptual diagram which shows the structure of the manufacturing apparatus of the embossed sheet | seat to which this invention is applied. Table showing the formulation of each resin solution Sectional view showing the outline of the embossing roller Table showing conditions and evaluation results of Examples and Comparative Examples Sectional view showing the outline of the embossed sheet The conceptual diagram which shows the structure of the manufacturing apparatus of the embossed sheet of a prior art example The conceptual diagram which shows the other structure of the manufacturing apparatus of the embossed sheet | seat of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Embossed sheet manufacturing apparatus, 11 ... Sheet supply means, 12 ... Application means, 13 ... Emboss roller, 14 ... Nip roller, 15 ... Resin curing means, 16 ... Peeling roller, 17 ... Protective film supply means, 18 ... Sheet winding Removing means, H ... protective film, W ... sheet

Claims (8)

In the method for producing a concavo-convex sheet by transferring the concavo-convex on the surface of the concavo-convex roller to the surface of the sheet-like body,
By applying a resin liquid diluted with an organic solvent, a strip-like flexible sheet-like body having a resin liquid layer formed on the surface is continuously run,
Drying the organic solvent contained in the resin liquid layer;
The sheet-like body after drying is wound around the rotating uneven roller, and the unevenness on the uneven roller surface is transferred to the resin liquid layer,
The method for producing a concavo-convex sheet, comprising curing the resin liquid layer in a state where the sheet-like body is wound around the concavo-convex roller.   The method for producing a concavo-convex sheet according to claim 1, wherein the resin liquid is a radiation curable resin liquid, and the resin liquid layer is cured by irradiating the resin liquid layer with radiation.   The method for producing a concavo-convex sheet according to claim 1 or 2, wherein the resin liquid contains 10% by weight or more of an organic solvent.   The method for producing a concavo-convex sheet according to any one of claims 1 to 3, wherein the application of the resin liquid is performed by a die coater, a bar coater, a roll coater, or a gravure coater. The method for producing a concavo-convex sheet according to any one of claims 1 to 4, wherein the resin liquid contains at least the following compounds (A) and (B).
(A) A compound containing an acroyl group and / or a vinyl group polymerizable group (B) A compound capable of generating an active species capable of polymerizing the compound (A) by irradiation with radiation   The method for producing a concavo-convex sheet according to any one of claims 1 to 5, wherein the viscosity of the resin liquid at the time of application is 100 mPa · s or less. Sheet-like body supply means for feeding out a belt-like flexible sheet-like body;
Application means for applying a resin liquid diluted with an organic solvent to the surface of the sheet-like body,
A drying means for drying the organic solvent contained in the resin liquid layer;
A transfer means for transferring the irregularities on the surface of the uneven roller onto the surface of the sheet-like body while winding the continuously traveling sheet-like member around a rotating uneven roller;
A resin liquid curing means for curing the resin liquid in a state where the sheet-like body is wound around the uneven roller;
An apparatus for producing an uneven sheet, comprising:   The apparatus for producing a concavo-convex sheet according to claim 7, wherein the resin liquid curing unit is a radiation irradiating unit provided in the vicinity of the concavo-convex roller.

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