JP5751480B2 - Scraping device, contrast improving sheet manufacturing apparatus including the same, and contrast improving sheet manufacturing method - Google Patents

Description

  The present invention relates to a scraping device, a contrast-enhancing sheet manufacturing apparatus including the scraping device, and a contrast-enhancing sheet manufacturing method.

  In a liquid crystal display device, it is usually preferred that the viewing angle is wide so that a good image can be obtained from any position of the observer. On the other hand, for example, when working on a commuter train or in a liquid crystal display device installed in a public place such as an ATM, it may be difficult to see the screen from people around you. There is a demand for a peeping prevention function for protecting privacy so that it can be seen only by an observer of the display device and cannot be seen by others. In car-mounted liquid crystal display devices such as car navigation systems, the screen of the liquid crystal display device is reflected on the window glass at night and the like, and the phenomenon of blocking the field of view occurs. Control of the light emission angle is desired.

  In response to such a demand, for example, Japanese Patent Laid-Open No. 2006-119365 (Patent Document 1) proposes a louver type optical sheet having a structure in which light transmission layers and light shielding layers are alternately arranged. In addition, it is disclosed to use a light shielding layer in which a material constituting the light transmission layer is mixed with a filler such as carbon black or carbon fiber.

  On the other hand, the louver-type optical sheet as described above simply cuts the image light in the oblique direction. Therefore, depending on the type of the display device, the diffusion light source of the image light that should reach the observer is reduced. As a result, the brightness of the display screen may be reduced.

  In order to solve the above problem, it has been proposed to install a contrast enhancing sheet that can improve the contrast by blocking external light and reduce the occurrence of double images. As such a contrast improving sheet, sheets having various structures have been proposed. For example, a light transmitting portion having a plurality of grooves arranged in parallel on the surface, a material having a refractive index lower than that of the light transmitting portion, and a carbon pigment. Have been proposed (for example, Japanese Patent Application Laid-Open No. 2006-85050, etc .: Patent Document 2).

  Then, in the production of the contrast enhancing sheet, an ink composition in which colored resin beads are mixed with a lens material such as an ionizing radiation curable resin is filled in the groove of the light transmitting portion, and is cured by irradiating with ionizing radiation. (For example, International Patent Application Publication No. WO2006 / 090784: Patent Document 3).

  The ink composition is filled by, for example, supplying the ink composition to the surface of the light transmitting portion from the upstream side of the doctor blade while moving the sheet-shaped light transmitting portion having a plurality of grooves arranged on the surface. The ink composition can be formed by scraping the ink composition on the surface of the light transmitting portion with a single doctor blade while forming an ink reservoir upstream of the blade and in the immediate vicinity of the doctor blade.

  However, when the ink composition is filled by such a method, strip-shaped filling unevenness, streaks, and the like are likely to occur. Since the appearance quality of the contrast enhancing sheet is directly related to the image quality, high quality is required. For this reason, it is preferable to reduce the above-mentioned filling unevenness and streak defect as much as possible.

JP 2006-119365 A JP 2006-85050 A International Application Publication WO2006 / 090784

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a scraping device, a contrast improving sheet manufacturing apparatus, and a contrast improving sheet manufacturing method capable of obtaining a contrast improving sheet with reduced streak defects and filling unevenness.

  As a result of intensive studies to reduce filling unevenness and streak defects, the present inventors have found that a first scraping blade and a second scraping blade disposed downstream of the first scraping blade It was found that when the ink composition that adheres to the first scraping blade and solidifies was suppressed, filling unevenness and streaks could be reduced. Here, in the present specification, the term “streak failure” means to include all of white stripes, pitch stripe failures, and black stripe failures. The “white stripe” means that the groove is not filled with the ink composition and the light absorption part is partially recessed. “Pitch streak failure” means that the light absorbing portion is partially recessed, and the recess is linear. The “black stripe defect” means that the ink composition remains on the light transmitting portion after the ink composition is scraped off, and the ink composition is linear or dotted. The black streak defect is sometimes called “fogging”. The present invention has been completed based on such findings.

  According to one aspect of the present invention, it is used for manufacturing a contrast-enhancement sheet comprising a light transmission part having a plurality of grooves arranged in parallel on the surface and a light absorption part formed in the groove of the light transmission part. A first scraping device that has a through-hole at the tip for scraping the ink composition supplied onto the surface from the surface of the light transmitting portion having a plurality of grooves arranged in parallel on the surface. The scraping blade and the first scraping blade are arranged at a predetermined interval, and the ink composition remaining on the surface of the light transmitting portion after scraping by the first scraping blade is further scraped. A second scraping blade for removing, and a suction mechanism for sucking the ink composition that has entered the space between the first scraping blade and the second scraping blade through the through hole; A scraping device is provided, characterized in that .

  According to another aspect of the present invention, in a contrast-enhancement sheet manufacturing apparatus comprising: a light transmissive portion having a plurality of grooves arranged in parallel on a surface; and a light absorbing portion formed in the groove of the light transmissive portion. And the manufacturing apparatus of the contrast improvement sheet | seat characterized by providing said scraping apparatus is provided.

  According to another aspect of the present invention, there is provided a method for manufacturing a contrast enhancing sheet, comprising: a light transmission part having a plurality of grooves arranged in parallel on a surface; and a light absorption part formed in the groove of the light transmission part. The ink composition is continuously supplied to the surface of the light transmission part while moving the sheet-like light transmission part in which a plurality of grooves are arranged in parallel on the surface, from the supply position of the ink composition The ink composition on the surface of the light transmitting portion while forming an ink reservoir made of an ink composition on the upstream side of the first scraping blade disposed on the downstream side and in the immediate vicinity of the first scraping blade Filling the object with the first scraping blade and the second scraping blade disposed at a predetermined distance downstream from the first scraping blade and with the first scraping blade. And the first scraping blade comprises a front The first scraping blade has a through hole at a tip thereof, and the filling step enters the space between the first scraping blade and the second scraping blade through the through hole. A method for producing a contrast-enhancing sheet is provided, which is performed while sucking the ink composition.

  According to the scraping device of one aspect of the present invention, the contrast-enhancing sheet manufacturing apparatus of another aspect of the present invention, and the contrast-enhancing sheet manufacturing method of another aspect of the present invention, filling unevenness and streak defects are reduced. A contrast-enhancing sheet can be obtained.

1 is a schematic configuration diagram of a contrast-enhancement sheet manufacturing apparatus according to a first embodiment. It is the figure which looked at the scraping device periphery of FIG. 1 from the upstream. It is sectional drawing of the holder of FIG. It is a front view of the 1st scraping blade and the 2nd scraping blade concerning a 1st embodiment. It is a side view of the holder of FIG. It is a side view of the other holder which concerns on 1st Embodiment. It is the figure which showed typically the inner corner part of the holder which concerns on 1st Embodiment. It is the figure which showed typically the manufacturing process of the contrast improvement sheet | seat which concerns on 1st Embodiment. It is the figure which showed typically the formation process of the light transmissive part which concerns on 1st Embodiment. It is the figure which showed the base material which has the adhesion layer and peeling layer which concern on 1st Embodiment. It is the figure which showed typically the mode of scraping of the ink composition by the scraping apparatus which concerns on 1st Embodiment. It is sectional drawing of the display apparatus provided with the contrast improvement sheet | seat which concerns on 1st Embodiment. It is a schematic block diagram of the apparatus for manufacturing a contrast enhancing sheet according to the second embodiment. It is sectional drawing of the holder of FIG. FIG. 15 is a perspective view of the spacer shown in FIG. 14. It is a perspective view of the other spacer which concerns on 2nd Embodiment. It is the figure which showed typically the mode of scraping of the ink composition by the scraping apparatus which concerns on 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
<Scraping device and contrast-enhancement sheet manufacturing device>
First, a scraping device and a contrast-enhancing sheet manufacturing device according to the present invention will be described. FIG. 1 is a schematic configuration diagram of a contrast-enhancement sheet manufacturing apparatus according to the present embodiment, FIG. 2 is a view of the periphery of the scraping apparatus of FIG. 1 from the upstream side, and FIG. FIG. FIG. 4 is a front view of the first scraping blade and the second scraping blade according to the present embodiment, and FIG. 5 is a side view of the holder of FIG. FIG. 6 is a side view of another holder according to the present embodiment, and FIG. 7 is a view schematically showing an inner corner of the holder according to the present embodiment. In addition, the arrow A in FIGS. 1-3, 5, and 6 represents the moving direction of a light transmissive part, and the arrow B in FIG. 1 represents the circulation direction of an ink composition.

  A contrast-enhancing sheet manufacturing apparatus 10 shown in FIG. 1 is for filling an ink composition 3 in a groove 1b of a light transmitting portion 1 having grooves 1b arranged in parallel on a surface 1a. 20, a supply device 30, a scraping device 40, and an ink circulation system 60.

  The light transmission part 1 shown in FIG. 1 is formed on the base material 2, and the groove 1 b has a substantially trapezoidal shape that tapers toward the base material 2 side. The groove 1b is not limited to a substantially trapezoidal shape, and may be formed in, for example, a substantially V shape or a substantially rectangular shape. Further, the groove 1b extends along the longitudinal direction of the light transmission part 1 (direction orthogonal to the width direction of the light transmission part 1). The entire width of the light transmission part 1 can be set to 500 to 1500 mm.

  The conveyance system 20 is for conveying the light transmission part 1 with the base material 2 to one direction, and is comprised from the conveyance roll. The line speed (transport speed) of the transport system 20 is preferably 1 to 50 m / min, although it depends on the supply speed of the ink composition 3.

  The supply device 30 is for supplying the ink composition 3 to the surface 1 a of the light transmission portion 1. The supply device 30 is preferably capable of uniformly supplying the ink composition 3 in the width direction of the light transmitting portion 1. The supply rate of the ink composition 3 by the supply device 30 is preferably 0.5 to 10 L / min.

  Examples of the supply device 30 include a die coater, a bar coater, a roll coater, and a knife coater. Among these, the ink composition 3 is uniformly applied to the surface 1 a of the light transmitting portion 1 in the width direction of the light transmitting portion 1. A die coater that can be supplied is preferred.

  The scraping device 40 is disposed downstream of the supply position of the ink composition 3 by the supply device 30. The scraping device 40 is a first scraping blade 41 that scrapes the ink composition 3 supplied onto the surface 1a of the light transmitting portion 1 shown in FIG. 3 and light after scraping by the first scraping blade 41. A second scraping blade 42 for further scraping off the ink composition 3 remaining on the surface 1a of the transmission part 1 and a suction mechanism 43 for sucking the ink composition 3 shown in FIG. 1 are provided. In this embodiment, as shown in FIGS. 1 and 3, a holder 44 that holds the first scraping blade 41 and the second scraping blade 42 is provided.

  As shown in FIGS. 3 and 4, a through hole 41 b is provided in the tip end portion 41 a of the first scraping blade 41. A plurality of through holes 41 b shown in FIG. 4 are provided at predetermined intervals along the width direction of the first scraping blade 41. By providing a through hole 41b in the first scraping blade 41, a part of an ink reservoir 3a (see FIG. 2), which will be described later, made of the ink composition 3 is shown in FIG. 3 through the through hole 41b. It is possible to enter the space S between the first scraping blade 41 and the second scraping blade 42.

  The through holes 41b shown in FIG. 4 are provided at equal intervals. In the width direction of the first scraping blade 41, the distance between the through holes 41b from the center portion to the end portion of the first scraping blade 41 is shown. May be wider. Moreover, although the through-hole 41b shown by FIG. 4 is circular shape, the shape of the through-hole 41b is not specifically limited, For example, elliptical shape and square shape other than circular shape may be sufficient. It is preferable that three or more through holes 41b are provided.

  When the through hole 41b is circular, the diameter of the through hole 41b is preferably 1 to 10 mm. This numerical range is preferable because the ink composition 3 may not be sufficiently supplied from the through hole 41b to the space S when the diameter of the through hole 41b is less than 1 mm. This is because if the diameter exceeds 10 mm, the strength of the first scraping blade 41 is lowered, and there is a possibility that the scraping is insufficient or the first scraping blade 41 is damaged.

  As shown in FIG. 3, the second scraping blade 42 is disposed downstream of the first scraping blade 41 with respect to the movement direction of the light transmission unit 1. Further, the first scraping blade 41 and the second scraping blade 42 are disposed so as to be substantially orthogonal to the extending direction of the groove 1b.

  The first scraping blade 41 and the second scraping blade 42 are thin plate-like, and the thickness of the first scraping blade 41 and the second scraping blade 42 can be about 200 μm. . For example, a doctor blade or the like can be used as the first scraping blade 41 and the second scraping blade 42.

  The width of the first scraping blade 41 and the width of the second scraping blade 42 are appropriately determined depending on the width of the substrate 2 to be used. For example, the width of the first scraping blade 41 and the second scraping blade 42 The width is preferably 50 to 300 mm shorter than the width of the substrate 2. This numerical range is preferable because when the width of the first scraping blade 41 and the width of the second scraping blade 42 are shorter than the width of the base material 2 by less than 50 mm, the ink composition 3 becomes the base material 1. If the width of the first scraping blade 41 and the width of the second scraping blade 42 are shorter than the width of the base material 2 by more than 300 mm, the loss of the base material 2 may occur. This is because there is a risk of becoming uneconomical.

  In the first scraping blade 41 shown in FIG. 4, the width of the first scraping blade 41 is shorter than the width of the second scraping blade 42. Specifically, for example, the width of the first scraping blade 41 is preferably 5 to 30 mm shorter than the width of the second scraping blade 42. This numerical range is preferable because when the width of the first scraping blade 41 is shorter than the width of the second scraping blade 42 by less than 5 mm, from the suction hole 48a provided in the weir 48 described later, This is because it may be difficult to suck the ink composition 3 that has entered the space S. If the width of the first scraping blade 41 is shorter than the width of the second scraping blade by more than 30 mm, the scraping property of the ink composition 3 by the scraping device 40 is inferior, and filling unevenness and streaks are reduced. Defects may occur.

  As shown in FIG. 3, the first scraping blade 41 is arranged so that the tip 41 c of the first scraping blade 41 is in contact with the surface 1 a of the light transmitting portion 1, and the second scraping blade 41. The blade 42 is preferably held by the holder 44 so that the tip 42 a of the second scraping blade 42 is separated from the surface 1 a of the light transmitting portion 1.

It is preferable that the tip 42 a of the second scraping blade 42 protrudes from 0.25 mm to 0.55 mm with respect to the tip 41 c of the first scraping blade 41. Here, the fact that the tip 42a of the second scraping blade 42 protrudes 0.25 mm to 0.55 mm from the tip 41c of the first scraping blade 41 means that the protrusion length L ₁ shown in FIG. Is 0.25 mm to 0.55 mm.

  The distance d between the first scraping blade 41 and the second scraping blade 42 shown in FIG. 3 is preferably 0.05 to 2 mm. This numerical range is preferable because when the distance d is less than 0.05 mm, the first scraping blade 41 and the second scraping blade 42 overlap, and the ink composition 3 is scraped off. May be insufficient. If the distance d exceeds 2 mm, the ink composition 3 is clogged between the first scraping blade 41 and the second scraping blade 42, which may cause pitch streaks. In order to set the distance d within this numerical range, a spacer 49 described later having a thickness of 0.05 to 2 mm is disposed between the first scraping blade 41 and the second scraping blade 42. Good.

  As shown in FIG. 3, the angles α and β of the tip portion 41a of the first scraping blade 41 and the tip portion 42b of the second scraping blade 42 with respect to the surface 1a of the light transmitting portion 1 are 40 ° to 70 °. It is preferable that it is 50 ° to 65 °. The reason why this numerical range is preferable is that if the angles α and β are less than 40 °, the ink composition 3 may be insufficiently scraped, and the angles α and β may be 70 °. If exceeded, the scraping efficiency by the first scraping blade 41 and the second scraping blade 42 is improved, but the first scraping blade 41 and the second scraping blade 42 that come into contact with the ink composition 3 are improved. This is because, since the area is small, black stripe defects may occur.

  The suction mechanism 43 is for sucking the ink composition 3 that has entered the space S through the through hole 41b. As shown in FIG. 1, the suction mechanism 43 includes a suction machine 45 such as an air suction cleaner and a suction hose 46 having one end connected to the suction machine 45. The diameter of the suction hose 46 is not particularly limited, but can be about 10 to 15 mm.

  The suction of the ink composition 3 by the suction mechanism 43 is performed through a suction hole provided in the holder 44 and communicating with the space S between the first scraping blade 41 and the second scraping blade 42. Is preferred. By carrying out through such a suction hole, even if the space S is narrow, the ink composition 3 that has entered the space S can be reliably sucked.

  Hereinafter, an example in which a suction hole communicating with the space S is provided in the holder 44 will be described. In the present invention, as long as the ink composition 3 entering the space S can be sucked, the ink composition 3 may not be sucked through the suction holes provided in the holder 44. Specifically, for example, it is also possible to arrange a nozzle or the like directly in the space S and suck the ink composition 3 that has entered the space S.

  The holder 44 includes at least a holder body 47 that holds the first scraping blade 41 and the second scraping blade 42, and weirs 48 provided at both ends of the holder body 47 (FIGS. 3 and 3). 5). In the present embodiment, the holder 44 includes a spacer 49 and a contact plate 50 in addition.

  The holder main body 47 sandwiches the first scraping blade 41 and the second scraping blade 42. The weir 48 is for holding an ink reservoir 3a (see FIG. 2) made of the ink composition 3 formed on the upstream side of the first scraping blade 41 and in the immediate vicinity of the first scraping blade 41. is there. As shown in FIG. 7, the weir 48 protrudes from the first scraping blade 41 toward the scraping surface 41 d of the first scraping blade, that is, the upstream side.

  As shown in FIGS. 5 and 7, the weir 48 is provided with a suction hole 48 a for sucking the ink composition 3 that has entered the space S. Here, in this embodiment, since the width of the first scraping blade 41 is shorter than the width of the second scraping blade 42, the space S is located on the scraping surface 41 d side of the first scraping blade 41. It communicates with the space. Therefore, when suction is performed from the suction hole 48a, the ink composition that has entered the space S moves as indicated by an arrow C in FIG. 7 and is sucked from the suction hole 48a, and upstream of the first scraping blade 41. A part of the ink reservoir 3a formed on the side and nearest is moved as indicated by an arrow D in FIG. 7 and sucked from the suction hole 48a. That is, the suction hole 48a also functions as a suction hole for sucking a part of the ink reservoir 3a.

  The suction hole 48a shown in FIGS. 5 and 7 has both a role for sucking the ink composition 3 that has entered the space S and a role for sucking a part of the ink reservoir 3a. A suction hole for sucking the ink composition 3 that has entered the space S and a suction hole for sucking a part of the ink reservoir 3 a may be separately provided in the 48. For example, as shown in FIG. 6, a suction hole 48 b for sucking the ink composition 3 that has entered the space S is provided at a position between the first doctor blade 41 and the second doctor blade 42 in the weir 48. In addition to the suction hole 48b, a suction hole 48c for sucking a part of the ink reservoir 3a may be provided at a position upstream of the first scraping blade 41 in the weir 48. In this case, the width of the first scraping blade 41 may be the same as the width of the second scraping blade 42.

  One end of the suction holes 48 a to 48 c shown in FIGS. 5 and 6 is preferably located on the bottom surface 48 d of the weir 48. The other ends of the suction holes 48 a to 48 c are located on the outer side surface 48 e of the weir 48. The suction holes 48a to 48c are connected to the suction hose 46 in the outer side surface 48e.

  As shown in FIG. 5 and FIG. 6, when one end of the suction holes 48 a to 48 c is formed on the bottom surface 48 d, the weir 48 is part of the ink composition 3 and the ink reservoir 3 a that have entered the space S. It is preferable that a slight gap be provided between the bottom surface 48d of the weir portion 48 and the surface 1a of the light transmitting portion 1 so as to be able to suck.

  The diameter of the suction holes 48a to 48c is preferably 10 to 16 mm. The reason why this numerical range is preferable is that if the diameter is less than 10 mm, it takes a long time to suck the ink composition 3. If the diameter exceeds 16 mm, the ink composition is excessively excessive. This is because the object 3 is sucked.

  As shown in FIG. 3, the contact plate 50 is attached to a surface of the second scraping blade 42 opposite to the surface (scraping surface) on the first scraping blade 41 side. Although the material which comprises this board 50 is not specifically limited, For example, stainless steel etc. can be used. The thickness of the plate 50 is preferably 150 to 1000 μm. This numerical range is preferable because if the thickness of the contact plate 50 is less than 150 μm, the rigidity of the contact plate 54 is insufficient and black streaks are likely to occur. If the thickness exceeds 1000 μm, the rigidity of the contact plate 50 becomes more than necessary, and the bending of the second scraping blade 42 cannot be used, and the filling rate of the ink composition 3 may be reduced. It is.

The plate 50 has a vertical length of a portion of the second scraping blade 42 not covered by the plate 50, that is, the lower end 50a of the plate 50 shown in FIG. The length L2 to the tip 42a is preferably 1 to 10 mm, and more preferably ₃ to 7 mm. This numerical range is a preferable, since the length L ₂ is less than 1 mm, it becomes impossible to use the Nari second scraping blade 42 Works by enhancing the rigidity by contact plate 50, the ink composition is because the third filling rate may be lowered, also the length L ₂ is more than 10 mm, because black streaks rigidity of contact plate 50 is insufficient is likely to easily occur.

  The ink circulation system 60 is for collecting the sucked ink composition 3 and supplying the ink composition 3 to the supply device 30 again.

  As shown in FIG. 1, the ink circulation system 60 includes pumps 61 and 62 such as a diaphragm pump, a mixing tank 63, an unused ink composition storage tank 64, a filter 65, and the like. The pump 61 is for conveying the ink composition 3 sucked by the suction mechanism 43 and sending it to the mixing tank 63, and is arranged at the rear stage of the suction mechanism 43. The mixing tank 63 is for mixing the collected used ink composition 3 and the unused ink composition 3 b stored in the unused ink composition storage tank 64.

  In the mixing tank 63, the used ink composition 3 and the unused ink composition 3b are preferably mixed so that the mixing ratio is 1: 4 to 4: 1. Further, in the mixing tank 63, the viscosity of the ink composition 3 is adjusted so that the viscosity of the ink composition 3 after mixing is preferably 2500 to 5000 mPa · s, more preferably 3000 to 4000 mPa · s. Is done. This numerical range is preferable because if the viscosity of the ink composition 3 is less than 2500 mPa · s, it may be difficult to fill the groove 1b with the ink composition 3, and the ink composition 3 If the viscosity exceeds 5000 mPa · s, it may be difficult to suck a part of the ink reservoir 3a.

  The pump 62 is for sending the mixed ink composition 3 in the mixing tank 63 to the supply device 30, and the filter 65 is interposed between the pump 62 and the supply device 30.

  Next, the ink composition 3 will be described. The unused ink composition 3b has the same composition as the ink composition 3. The ink composition 3 includes a transparent ionizing radiation resin composition and light absorbing particles. As the ionizing radiation curable resin composition, an ionizing radiation curable resin composition used for a conventionally known visibility improving sheet or viewing angle improving sheet can be used. For example, those having an acrylate functional group can be suitably used. Specifically, polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetals having a relatively low molecular weight can be used. Examples thereof include oligomers or prepolymers such as (meth) allylates of polyfunctional compounds such as resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols. Although depending on the material constituting the light transmitting portion of the visibility improving sheet, a resin having a refractive index smaller than that of the material constituting the light transmitting portion may be selected from these resins.

  In addition, a reactive diluent may be added to the resin composition. Examples of such a reactive diluent include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N- Monofunctional monomers such as vinyl pyrrolidone and polyfunctional monomers may be used. Specifically, dimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di ( Examples include meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like.

  In order to convert the ionizing radiation curable resin composition into an ultraviolet curable resin composition, acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester, tetramethylchuram mono as a photopolymerization initiator in the composition. A mixture of sulfides, thioxanthones, n-butylamine, triethylamine, poly-n-butylphosphine, or the like as a photosensitizer can be used. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

  As the light absorbing particles, resin beads or glass beads may be light absorbing particles that can selectively absorb a specific wavelength according to the characteristics of the image light. Carbon black, graphite, fibrous carbon, black oxidation What knead | mixed colorants, such as metal salts, such as iron, dye, and a pigment, can be used. From the viewpoint of easy kneading of the colorant, it is preferable to use resin beads. As the resin beads, melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, polystyrene beads, polyvinyl chloride beads and the like can be suitably used. Further, urethane cross-linked fine particles and silicon-based beads can also be suitably used. These resin beads are preferably those having a refractive index difference of about 0.1 of the ionizing radiation curable resin composition described above. Also, as the resin before kneading the colorant, a transparent resin can be used, but it is preferable to use a resin colored with a pigment or a dye, and a specific wavelength is selectively selected according to the characteristics of the image light. However, resin beads colored in black are preferably used.

  Among the above-mentioned materials, carbon black can be preferably used as the colorant. The amount of carbon black kneaded into the resin beads is about 0.1 to 0.7 parts by mass, preferably 0.15 to 0.5 parts by mass, more preferably 1 part by mass of the resin beads. Is 0.2 to 0.35 parts by mass. When the amount of kneading of carbon black is more than 0.7 parts by mass, the resin beads may be easily broken. On the other hand, when the amount is less than 0.1 parts by mass, light absorbing particles having desired blackness can be obtained. There may not be. Carbon black having an average particle diameter of 10 to 500 nm can be suitably used. For example, furnace black, acetylene black, channel black, thermal black, carbon nanotube, carbon fiber and the like can be used. Commercially available products can also be used. For example, HCF series, MCF series, RCF series, LFF series (all manufactured by Mitsubishi Chemical Corporation), Vulcan series (made by Cabot Corporation), Ketjen series (Lion Corporation) Can be suitably used. Here, the average particle diameter means an arithmetic average diameter obtained by observing carbon black particles with an electron microscope.

  In order to improve the dispersibility of the light absorbing particles in the ionizing radiation curable resin composition, the light absorbing particles may be surface-treated. Examples of the surface treatment include hydrophilic treatment with a conventionally known silica coating and surface modification with plasma or the like.

  The ink composition 3 containing each component described above is prepared by mixing a predetermined amount of light-absorbing particles into an ionizing radiation curable resin composition and adding a polymerization initiator or the like as desired. The addition amount of the light absorbing particles is preferably in the range of 15 to 35% with respect to the total mass of the ink composition. By setting this range, it is possible to realize a contrast-enhancement sheet with more excellent contrast. If the light-absorbing particle content is too small, the light-shielding property of the light-absorbing part may be insufficient. If the light-absorbing particle content is too large, the resin beads may come into contact with each other, causing problems such as cracking and chipping. It tends to occur.

<Method for producing contrast improving sheet>
Next, a method for producing a contrast enhancing sheet according to the present invention will be described with reference to the drawings. FIG. 8 is a diagram schematically illustrating the manufacturing process of the contrast improving sheet according to the present embodiment, and FIG. 9 is a diagram schematically illustrating the process of forming the light transmission portion according to the present embodiment. FIG. 11 is a diagram showing a substrate having an adhesive layer and a release layer according to the present embodiment, and FIG. 11 is a diagram schematically showing how the ink composition is scraped by the scraping device according to the present embodiment. is there.

  First, the light transmission part 1 in which a plurality of grooves 1b are arranged in parallel in the cross section in the layer thickness direction is formed on the substrate 2 (FIG. 8A).

  The base material 2 is a layer serving as a base for forming the light transmission part 1 and a light absorption part 4 described later. As the base material 2, a transparent resin film, a transparent resin plate, a transparent resin sheet, or transparent glass can be used. Transparent resin films include triacetate cellulose (TAC) film, polyester film such as polyethylene terephthalate (PET), diacetyl cellulose film, acetate butyrate cellulose film, polyethersulfone film, polyacrylic resin film, polyurethane resin film Polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyether ketone film, (meth) acrylonitrile film, etc. can be suitably used. Among these, polyester films are preferably used. . Examples of the polyester film include polyethylene terephthalate, polybutylene terephthalate, polynaphthalene terephthalate, and polytrimethylene terephthalate.

  The formation of the light transmitting portion 1 varies depending on the type of resin used. For example, when the light transmitting portion 1 is formed using a transparent thermoplastic resin, a hot press method or an injection molding method in which a heated mold is pressed against the thermoplastic resin, or a thermoplastic resin monomer is injected into the mold Then, the light transmitting portion 1 can be formed by a casting method for polymerization and solidification. In the case of using an ionizing radiation curable resin, particularly an ultraviolet curable resin, the light transmitting portion 1 is formed by a so-called UV method in which the resin is injected into a mold and irradiated with ultraviolet rays to be cured. Can do. Among these methods, in the present invention, the UV method excellent in mass productivity can be suitably used. According to the UV method, the light transmission part 1 can be continuously manufactured using a mold roll.

  Specifically, for example, as shown in FIG. 9, the base material 2 is fed between a die roll 70 having a groove corresponding to the shape of the light transmitting portion 1 and a nip roll 71 at a predetermined pitch. The arrow in FIG. 9 represents the direction in which the base material 2 is fed. In accordance with the feeding of the base material 2, droplets of the composition 73 for a light transmission part containing, for example, an ultraviolet curable resin or the like are continuously supplied from the supply device 72 between the mold roll 70 and the base material 2. When supplying the light transmitting portion composition 73 from the supply device 72 onto the base material 2, a composition reservoir 74 in which the light transmitting portion composition 73 is stored is formed between the mold roll 70 and the base material 2. To be. By forming the composition reservoir 74, the light transmitting portion composition 73 spreads in the width direction of the substrate 2.

  The light transmitting portion composition 73 supplied between the mold roll 70 and the base material 2 as described above is applied to the base material 2 and the mold by the pressing force between the mold roll 70 and the nip roll 71. It is filled between the rolls 70. Thereafter, the light transmitting portion composition 73 is irradiated with ultraviolet rays by the ionizing radiation irradiation device 75 to cure the light transmitting portion composition 73 to form the light transmitting portion 1. After forming the light transmission part 1, the light transmission part 1 is peeled off from the mold roll 70 via the peeling roll 76.

  The base material 2 fed into the mold roll 70 may include an adhesive layer 6 and a release layer 7 as shown in FIG. The adhesive layer 6 is for adhering the contrast enhancing sheet to the display unit of the display device. The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 6 is not particularly limited as long as it can transmit light and appropriately adhere another optical sheet. As an adhesive, an acrylic copolymer can be mentioned, for example.

  The release layer 7 is for preventing the adhesive layer 6 from coming into contact with others during handling, and is formed on the adhesive layer 6. Although it does not specifically limit as the peeling layer 7, For example, a polyethylene terephthalate (PET) resin etc. are mentioned.

  In addition, it is preferable to perform a hydrophilization treatment on the surface of the groove 1 b of the light transmitting portion 1 before the next filling step of the ink composition 3. By applying a hydrophilic treatment to the surface of the groove 1b, it becomes easier to fill the groove 1b with the ink composition, and the ink filling rate is improved. The hydrophilic treatment can be performed using a conventionally known method. Examples thereof include dry processes such as low-pressure plasma treatment, atmospheric pressure plasma treatment, corona treatment, ultraviolet irradiation treatment, and excimer lamp treatment, and wet processes such as alkali treatment with sodium hydroxide, potassium hydroxide, ethanolamine, and the like. Among these, atmospheric pressure plasma treatment is preferable from the viewpoint of production efficiency.

  After forming the light transmission part 1 on the base material 2, the ink composition 3 is filled in the groove 1b using the manufacturing apparatus 10 (FIG. 8B).

  Specifically, as shown in FIG. 1, first, the light transmission unit 1 is moved while the sheet-like light transmission unit 1 is moved together with the substrate 2 by the conveyance system 20 with respect to the supply device 30 and the scraping device 40. The ink composition 3 is continuously supplied from the supply device 30 to the surface 1 a of the first surface, and the ink composition 3 on the surface 1 a of the light transmitting portion 1 is scraped off by the scraping device 40 located downstream of the supply device 30. Thereby, the ink composition 3 is filled in the groove 1b, and the excess ink composition 3 present on the surface 1a of the light transmitting portion 1 is scraped off.

  Here, the ink composition 3 is supplied so that an ink reservoir 3 a made of the ink composition 3 is formed on the upstream side of the first scraping blade 41 and in the immediate vicinity of the first scraping blade 41. Specifically, the ink reservoir 3 a is formed by supplying the ink composition 3 to the surface 1 a of the light transmission portion 1 from the supply device 30 in a relatively excessive amount.

  Further, when the ink composition 3 is scraped off by the first scraping blade 41, the first scraping blade 41 is provided with a through hole 41b, so that the ink reservoir 3a is formed as shown in FIG. The ink composition 3 to be entered enters the space S between the first scraping blade 41 and the second scraping blade 42 through the through hole 41b. The ink composition 3 that has entered the space S is scraped off by the second scraping blade 42 and sucked by the suction mechanism 43 through the suction hole 48 a of the weir 48. In the present embodiment, the ink composition 3 is sucked from the end side in the width direction of the light transmitting portion 1.

  At the same time, a part of the ink reservoir 3 a is sucked by the suction mechanism 43 through the suction hole 48 a of the weir 48. The used ink composition 3 sucked from the suction holes 48 a is sent to the mixing tank 63 by the pump 61.

  The used ink composition 3 sent to the mixing tank 63 is mixed with the unused ink composition 3 b in the mixing tank 63, and then sent to the supply device 30 via the filter 65 by the pump 62. And it is again supplied to the surface 1a of the light transmission part 1 from the supply apparatus 30. FIG.

  After filling the groove 1b with the ink composition 3, the ink composition 3 in the groove 1b is cured by irradiating ionizing radiation to form a light absorbing portion 4 having a substantially trapezoidal cross-sectional shape (FIG. 8 ( c)). Thereby, the contrast improvement sheet | seat 5 is produced. The ink composition 3 can be cured by a normal curing method, that is, by irradiation with an electron beam or ultraviolet rays. For example, in the case of electron beam curing, 50 to 50 emitted from various electron beam accelerators such as a Cockloft Walton type, a bandegraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type An electron beam having an energy of 1000 keV, preferably 100 to 300 keV is used. In the case of ultraviolet curing, ultraviolet rays emitted from rays such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. Available.

  When the ink reservoir is formed, the amount of contact of the ink composition with the scraping blade increases. Then, the ink composition that has not been consumed in the ink reservoir stays, and the viscosity of the ink composition tends to increase with time. For this reason, the ink composition that has not been consumed solidifies on the surface of the scraping blade, which is considered to contribute to filling unevenness and streaks. On the other hand, according to this embodiment, since a part of the ink reservoir 3a enters the space S through the through hole 41b, the ink composition 3 that has not been consumed can be moved. Further, since the ink composition 3 that has entered the space S is sucked through the suction holes 48a, the ink composition 3 can be removed from the space S. Thereby, solidification of the ink composition 3 in the first scraping blade 41 can be suppressed, and filling unevenness and streak defects can be reduced.

  The increase in the viscosity of the ink composition causes the life of the ink composition to be shortened. However, according to the present embodiment, since the ink composition 3 and the ink reservoir 3a that have entered the space S are sucked, the ink composition The increase in the viscosity of the product 3 can be suppressed, and the life of the ink composition 3 can be extended.

  Furthermore, according to the present embodiment, it is possible to further reduce pitch streaks and black streaks due to the following reasons.

  For example, the tip of the second scraping blade is adjusted so that it protrudes more than 0.55 mm from the tip of the first scraping blade, and the tip of the first scraping blade is separated from the surface of the light transmitting portion. When the first scraping blade is disposed so that the tip of the second scraping blade is in contact with the surface of the light transmitting portion, the first scraping blade is disposed. The ink composition stays or clogs in the gap between the take-off blade and the surface of the light transmission part, and density unevenness of the ink composition is formed, which may cause a pitch line defect in the light absorption part. There is.

  Further, the tip of the second scraping blade is adjusted so that it protrudes less than 0.25 mm from the tip of the first scraping blade so that the tip of the first scraping blade contacts the surface of the light transmitting portion. If the second scraping blade is disposed so that the tip of the second scraping blade is separated from the surface of the light transmitting portion, the second scraping blade The scraping property by the ink is poor, the ink composition remains on the light transmission part, and there is a possibility that black stripe defects may occur.

  Further, even when the tip of the second scraping blade is adjusted so that it protrudes from 0.25 mm to 0.55 mm below the tip of the first scraping blade, the tip of the first scraping blade is light. When the first scraping blade is disposed so as to be in contact with the surface of the transmitting portion, and the second scraping blade is disposed so that the tip of the second scraping blade is in contact with the surface of the light transmitting portion. Since the first scraping blade is pushed into the surface of the light transmitting portion, the scraping performance by the second scraping blade is inferior, and there is a risk of black streak failure.

  On the other hand, as in the present embodiment, the tip 42a of the second scraping blade 42 is adjusted to protrude 0.25 mm to 0.55 mm from the tip 41c of the first scraping blade 41, so that the first The first scraping blade 41 is disposed so that the tip 41c of the scraping blade 41 is in contact with the surface 1a of the light transmitting portion 1, and the tip 42a of the second scraping blade 42 is the surface 1a of the light transmitting portion 1. In the case where the second scraping blade 42 is disposed so as to be separated from the surface, the stagnation or clogging of the ink composition 3 in the gap between the first scraping blade 41 and the surface 1a of the light transmitting portion 1 is reduced. can do. Thereby, pitch streak defects can be further reduced. Further, since the abutment plate 50 is attached to the second scraping blade 42, the movement of the second scraping blade 42 due to the movement of the light transmitting portion 1 can be suppressed, and the second scraping blade 42 The scraping property by 42 can be improved. Thereby, black stripe defects can be further reduced.

<Contrast improvement sheet>
The contrast enhancing sheet 5 obtained as described above includes a base material 2, a light transmitting portion 1 formed on the base material 2 and having a plurality of grooves 1b, and a light absorbing portion formed in the grooves 1b. 4 is provided.

  The light absorption unit 4 has a refractive index that is the same as or smaller than the refractive index of the light transmission unit 1. Since the refractive indexes of the light transmission unit 1 and the light absorption unit 4 are as described above, the image light from the light source incident on the light transmission unit 1 under a predetermined condition is received by the light absorption unit 4 and the light transmission unit 1. It is possible to provide a bright image to the observer by appropriately reflecting at the boundary surface. Further, since a part of the external light from the observer side is absorbed, the contrast is improved. In addition, stray light that is incident on the inner side of the light absorbing unit 4 without being reflected at the boundary surface between the light transmitting unit 1 and the light absorbing unit 4 is absorbed by the light absorbing material in the light absorbing unit 4. In addition, since the external light from the observer side incident at a predetermined angle can be appropriately absorbed, the contrast can also be improved.

  In addition, two layers of contrast enhancing sheets may be superposed, and in this case, each contrast enhancing sheet may have a different structure. For example, the width, pitch, depth, and shape of the light absorbing portion can be changed between the first layer contrast improving sheet and the second layer contrast improving sheet, or the direction of the light absorbing portion in the thickness direction can be changed. It is possible to change the bias angle of the light absorbing portion with respect to (the inclination angle of the light absorbing portion with respect to the horizontal direction). Moreover, the material (the kind of resin and the density | concentration of a light absorption particle) which forms a light absorption part can also be changed. For example, the first layer is designed to cut off external light efficiently and focus on improving the contrast, and the second layer is designed to focus on the front brightness improvement effect using reflection. It is preferable.

  The contrast enhancing sheet according to the present invention may include other functional layers employed in conventional optical sheets and viewing angle widening members. Specifically, an antireflection layer, an adhesive layer, an electromagnetic wave shielding layer, a wavelength filter layer, an antiglare layer, a hard coat layer, and the like may be appropriately combined. The order of stacking and the number of stacks of these functional layers can be appropriately determined according to the application.

  The contrast improving sheet according to the present invention can be disposed on a display unit of a display device, for example. Specifically, the contrast improving sheet can be used as an optical filter for a display device, for example. Examples of the display unit of the display device include a plasma display, a liquid crystal display, an organic EL display, a field emission display (FED), a surface conduction electron-emitting device display (SED), and a projection television.

<Optical filter for display device and display device>
Hereinafter, an example in which the contrast improving sheet according to the present invention is attached to a display unit of a display device as an optical filter for the display device will be described. FIG. 12 is a cross-sectional view of a display device including the contrast enhancing sheet according to the present embodiment. The display device 81 shown in FIG. 12 includes the contrast improving sheet 5 manufactured by the above-described manufacturing method. The contrast improving sheet 5 is attached to the display unit 82 of the display device 81 via the adhesive layer 83 so that the base material 2 is on the video light source side. On the front side of the contrast improving sheet 5, an antistatic layer 84, an antireflection layer 85, an antiglare layer 86, and the like are disposed. In the present embodiment, the antistatic layer 84 or the like is disposed on the front surface of the contrast enhancing sheet 5, but the present invention is not limited thereto, and a layer that blocks electromagnetic waves, infrared rays, or neon lines may be disposed. .

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings. FIG. 13 is a schematic configuration diagram of an apparatus for manufacturing a contrast enhancing sheet according to the present embodiment. 14 is a cross-sectional view of the holder of FIG. 13, and FIG. 15 is a perspective view of the spacer shown in FIG. FIG. 16 is a perspective view of another spacer according to the present embodiment, and FIG. 17 is a diagram schematically illustrating how the ink composition is scraped by the scraping device according to the present embodiment. In FIG. 13, FIG. 14 and FIG. 17, the same reference numerals as those in FIG. 1, FIG. 3, and FIG. This means the same as the members related to the reference numerals.

  As shown in FIG. 13, the contrast-enhancement sheet manufacturing apparatus 90 of the present embodiment has substantially the same configuration as the manufacturing apparatus 10 shown in FIG. 1, but the configuration of the scraping apparatus 100 is the scraping apparatus. The configuration of 40 is slightly different. Specifically, as shown in FIG. 14, the holder 101 of the scraping device 100 includes a spacer 102 having a suction hole 102 a instead of the spacer 49, and the ink composition 3 that has entered the space S is suctioned. Suction is performed by the suction mechanism 43 through the hole 102a. In the present embodiment, since the ink composition 3 that has entered the space S is sucked through the suction hole 102a, the width of the first scraping blade 41 is shorter than the width of the second scraping blade 42. Not necessary.

  The spacer 102 is formed in a comb-teeth shape as shown in FIG. That is, the suction hole 102a of the spacer 102 is a concave hole. The suction hole 102a penetrates from one surface 102b of the spacer 102 to the surface 102c opposite to the surface 102b. During suction, the second scraping blade 42 contacts the spacer 102, so that the opening surface of the suction hole 102 a is covered with the second scraping blade 42.

  Further, instead of the spacer 102, a spacer 103 shown in FIG. 16 may be used. The spacer 103 has a slit shape, that is, a shape divided into a plurality of portions, and a gap between each spacer 103 serves as a suction hole 103a.

  And the ink composition 3 is filled into the groove | channel 1b of the light transmissive part 1 using the manufacturing apparatus 90 provided with such a scraping apparatus 100. FIG. Specifically, as in the first embodiment, first, as illustrated in FIG. 13, the sheet-like light transmission unit 1 is attached to the base material 2 by the conveyance system 20 with respect to the supply device 30 and the scraping device 100. The ink composition 3 is continuously supplied from the supply device 30 to the surface 1 a of the light transmitting portion 1 while moving the ink transmissive portion 1, and the ink is disposed upstream of the first scraping blade 41 and in the immediate vicinity of the first scraping blade 41. The ink composition 3 on the surface 1a of the light transmitting portion 1 is scraped off by the scraping device 100 located downstream of the supply device 30 while forming the pool 3a.

  Further, FIG. 17 shows the ink composition 3 a that has entered the space S by the suction mechanism 43 while supplying the ink composition 3 from the supply device 30 and scraping the ink composition 3 by the scraping device 100. So as to suck through the suction hole 102a. In the case where the spacer 103 shown in FIG. 16 is used, the ink composition 3 is sucked through the suction hole 103a. In the present embodiment, the ink composition 3 is sucked from between the first scraping blade 41 and the second scraping blade 42. At the same time, a part of the ink reservoir 3a is sucked through the suction hole 48a by the suction mechanism 43.

  The used ink composition 3 sucked by the suction mechanism 43 circulates in the same manner as in the first embodiment, and is again supplied from the supply device 30 to the surface 1a of the light transmission portion 1.

  According to this embodiment, a part of the ink reservoir 3a enters the space S through the through hole 41b, and the ink composition 3 that has entered the space S is sucked through the suction holes 102a and 103a. Since it removes, the ink composition 3 which comprises the ink reservoir 3a can be moved. Thereby, solidification of the ink composition 3 in the first scraping blade 41 can be suppressed, and filling unevenness and streak defects can be reduced.

  Hereinafter, the present invention will be specifically described with reference to examples. In this example, a contrast improving sheet was produced by the same method as in the above embodiment, and the appearance of the contrast improving sheet was observed.

Example 1
<Scraping device>
A first doctor blade made of metal having a thickness of 200 μm as a first scraping blade, a second doctor blade made of metal having a thickness of 200 μm as a second scraping blade, a first doctor blade, and A scraping device including a holder for holding the second doctor blade was prepared.

  The width of the first doctor blade was 1150 mm, and the width of the second doctor blade was 1160 mm. That is, the width of the first doctor blade was 10 mm shorter than the width of the second doctor blade. Further, the first doctor blade was provided with through holes at 15 locations at intervals of 75 mm in the width direction of the first doctor blade.

  The holder is provided at both ends of the holder main body, the weir protruding from the first doctor blade toward the scraping surface side of the first doctor blade, the first doctor blade and the second doctor blade, And a spacer plate mounted on the second doctor blade.

  The holder body holds the first doctor blade and the second doctor blade so that the angles of the tip of the first doctor blade and the tip of the second doctor blade with respect to the surface of the light transmission part are both 65 °. Was. The spacer had a thickness of 0.05 mm. That is, the distance between the first doctor blade and the second doctor blade was 0.05 mm.

  A suction hole having a diameter of 6 mm communicated with the space between the first doctor blade and the second doctor blade was provided on the bottom surface of the weir. An air suction cleaner was connected to the suction hole via a suction hose.

<Preparation of ink composition>
As photocurable prepolymer, epoxy acrylate oligomer Oxirane, 2,2 '-[(1-methylethylidene) bis (4,1-phenyleneoxymethylene)] bis-, homopolymer, 2-propenoate, 20.0 parts by mass and reactive dilution monomer 20.0 parts by mass of 2-phenoxyethyl acrylate, 20.0 parts by mass of α-acryloyl-ω-phenoxypoly (oxyethylene), and 2- {2- [2- (acryloyloxy) (methyl) ethoxy] Acrylic crosslinked fine particles (manufactured by Ganz Kasei Co., Ltd.) 20.0 containing 13.0 parts by weight of (methyl) ethoxy} (methyl) ethyl acrylate and 25% carbon black having an average particle size of 4.0 μm as light absorbing particles 1 part by weight and 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, Ciba Specialty Chemicals Co., Ltd.) 7 parts by mass) (made by a formula company) were mixed and homogenized to obtain an ink composition.

  The viscosity of this ink composition at 25 ° C. was 4000 mPa · s. In the present invention, the viscosity was measured based on the rotational viscometer method of JIS K-5400. Specifically, a BL type viscometer manufactured by Tokyo Keiki Co., Ltd. Using a 4-rotor, the value indicated by the viscometer at 12 rpm and 1 minute at 25 ° C. was measured, and a value obtained by multiplying the measured value indicated by the viscometer by a conversion multiplier (500 in this condition) was defined as the viscosity.

In addition, the composition of the ink composition excluding the light-absorbing particles was applied at a thickness of 10 μm, cured by irradiating with 800 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp, and a multiwavelength Abbe refractometer DR-M4 (stock The refractive index of 589 nm was measured using a product of Atago Co., Ltd. and found to be 1.547.

<Adjustment of composition for light transmission part>
Bisphenol A-ethylene oxide 2 mol adduct 41 parts by mass, isophorone diisocyanate 14.0 parts by mass, and bismuth tri (2-ethylhexanoate) (2-ethylhexanoic acid 50% solution)) 0.02 mass as urethanization catalyst The urethane acrylate oligomer obtained by adding 5 parts by mass of 2-hydroxyethyl acrylate and reacting at 80 ° C. for 5 hours was used as a photocurable prepolymer. . This urethane acrylate oligomer 32, 0 parts by mass, 10.0 parts by mass of phenoxyethyl acrylate (molecular weight 192) as a photocurable monomer, and 30.0 masses of diacrylate (molecular weight 512) of EO4 mol adduct of bisphenol A And 0.03 parts by mass of a tetradecanol-ethylene oxide 10-mole adduct as a mold release agent (monoester / diester = molar ratio 1/1), and a tearylamine ethylene oxide 15-mole adduct 02 parts by mass, 3 parts by mass of 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) as a photopolymerization initiator are mixed and homogenized to obtain a composition for a light transmission part. Obtained.

The composition for a light transmitting portion was applied at a thickness of 100 μm, and the light transmitting portion constituting composition was cured by irradiating an ultraviolet ray of 800 mJ / cm ² with a high pressure mercury lamp, and the multiwavelength Abbe refractometer DR-M4 ( The refractive index of 589 nm was measured using Atago Co., Ltd. and found to be 1.550.

<Preparation of contrast improving sheet>
The composition for light transmission part is supplied onto a polyethylene terephthalate substrate (Toyobo Co., Ltd., A4300, thickness 100 μm, width 1400 mm), the composition for light transmission part is cured, and a plurality of grooves are formed on the surface. The light transmission part arranged in parallel was formed.

  Subsequently, the ink composition was filled in the groove of the light transmitting portion using the scraping device. Specifically, the ink composition obtained above is uniformly supplied in the width direction of the light transmitting portion from the die head of the die coater while moving the light transmitting portion together with the substrate at a line speed of 10 m / min. As described above, the ink was continuously supplied to the surface of the light transmission part at a supply rate of 5 L / min, and then the ink composition on the surface of the light transmission part was scraped off using the scraping device.

  The ink composition was supplied so that an ink reservoir was formed on the upstream side of the first doctor blade and in the immediate vicinity of the first doctor blade. Further, the first doctor blade is supplied by the air suction cleaner through the suction hole provided in the weir while supplying the ink composition from the die head and scraping the ink composition by the first and second doctor blades. The ink composition that entered the space between the first and second doctor blades was sucked, and a part of the ink reservoir was sucked through the suction holes. The used ink composition thus sucked was sent to a mixing tank by a pump and mixed with an unused ink composition in the mixing tank. Then, the mixed ink composition was sent to the die head through a filter by a pump, and again supplied from the die head to the surface of the light transmitting portion.

  After filling the groove of the light transmitting portion with the ink composition, the ink composition was irradiated with ultraviolet rays to cure the ink composition, thereby forming the light absorbing portion, and the contrast improving sheet of Example 1 was produced. .

(Example 2)
In Example 2, a contrast enhancing sheet was produced using a scraping device different from that in Example 1.

<Scraping device>
The scraping device used in Example 2 had almost the same configuration as the scraping device used in Example 1, but a concave suction hole was provided in the spacer. Specifically, the spacer was comb-like. The width of the first doctor blade and the second doctor blade was 1160 mm, and the width of the first doctor blade was the same as the width of the second doctor blade.

<Preparation of contrast improving sheet>
First, as in Example 1, the light transmissive part composition used in Example 1 was supplied onto a polyethylene terephthalate substrate (Toyobo Co., Ltd., A4300, thickness 100 μm, width 1400 mm) for light transmissive part. The composition was cured to form a light transmissive portion having a width of 1400 mm and having a plurality of grooves arranged on the surface.

  Next, the ink composition used in Example 1 was filled in the groove of the light transmitting portion using the scraping device of Example 2. Specifically, 5 L so that the ink composition is uniformly supplied in the width direction of the light transmitting portion from the die head of the die coater while moving the light transmitting portion together with the substrate at a line speed of 10 m / min. The ink composition on the surface of the light transmission part was scraped off using the scraping device of Example 2 after that.

  The ink composition was supplied so that an ink reservoir was formed on the upstream side of the first doctor blade and in the immediate vicinity of the first doctor blade. Further, the first doctor blade is supplied by the air suction cleaner through the suction hole provided in the spacer while the ink composition is supplied from the die head and the ink composition is scraped off by the first and second doctor blades. And the second doctor blade were sucked in, and a part of the ink reservoir was sucked by an air suction cleaner through a suction hole provided in the weir. The used ink composition thus sucked was sent to a mixing tank by a pump and mixed with an unused ink composition in the mixing tank. Then, the mixed ink composition was sent to the die head through a filter by a pump, and again supplied from the die head to the surface of the light transmitting portion.

  After filling the groove of the light transmitting portion with the ink composition, the ink composition was irradiated with ultraviolet rays to cure the ink composition, thereby forming the light absorbing portion, and the contrast improving sheet of Example 2 was produced. .

(Comparative Example 1)
In Comparative Example 1, a contrast improving sheet was prepared using a scraping device different from that in Example 1 and Example 2.

<Scraping device>
The scraping device used in Comparative Example 1 had almost the same configuration as the scraping device used in Example 1, but the number of doctor blades in this scraping device was not one, but one. . In addition, the doctor blade is not provided with a through hole, and the weir and the spacer are not provided with a suction hole. The width of the doctor blade was 1160 mm.

<Preparation of contrast improving sheet>
First, as in Example 1, the light transmissive part composition used in Example 1 was supplied onto a polyethylene terephthalate substrate (Toyobo Co., Ltd., A4300, thickness 100 μm, width 1400 mm) for light transmissive part. The composition was cured to form a light transmissive portion having a width of 1400 mm and having a plurality of grooves arranged on the surface.

  Next, using the scraping device of Comparative Example 1, the ink composition used in Example 1 was filled in the groove of the light transmitting portion. Specifically, 5 L so that the ink composition is uniformly supplied in the width direction of the light transmitting portion from the die head of the die coater while moving the light transmitting portion together with the substrate at a line speed of 10 m / min. The ink composition on the surface of the light transmissive part was scraped off using the scraping device of Comparative Example 1 after that.

  The ink composition was supplied so that an ink reservoir was formed on the upstream side of the doctor blade and in the immediate vicinity of the doctor blade. Further, the ink composition was supplied from the die head and the ink composition was scraped off by a doctor blade. In Comparative Example 1, the ink composition and the ink reservoir were not sucked.

  After filling the groove of the light transmitting portion with the ink composition, the ink composition was irradiated with ultraviolet rays to cure the ink composition, thereby forming the light absorbing portion, and the contrast improving sheet of Comparative Example 1 was produced. .

(Comparative Example 2)
In Comparative Example 2, a contrast improving sheet was prepared using a scraping device different from those in Example 1 and Example 2.

<Scraping device>
The scraping device used in Comparative Example 2 had almost the same configuration as the scraping device used in Example 1, but the first doctor blade was not provided with a through-hole, The spacer was not provided with a suction hole. The width of the first doctor blade and the second doctor blade was 1160 mm, and the width of the first doctor blade was the same as the width of the second doctor blade.

<Preparation of contrast improving sheet>
First, as in Example 1, the light transmissive part composition used in Example 1 was supplied onto a polyethylene terephthalate substrate (Toyobo Co., Ltd., A4300, thickness 100 μm, width 1400 mm) for light transmissive part. The composition was cured to form a light transmissive portion having a width of 1400 mm and having a plurality of grooves arranged on the surface.

  Next, using the scraping device of Comparative Example 2, the ink composition used in Example 1 was filled in the groove of the light transmitting portion. Specifically, 5 L so that the ink composition is uniformly supplied in the width direction of the light transmitting portion from the die head of the die coater while moving the light transmitting portion together with the substrate at a line speed of 10 m / min. The ink composition on the surface of the light transmission part was scraped off using the scraping device of Comparative Example 2 after that.

  The ink composition was supplied so that an ink reservoir was formed on the upstream side of the first doctor blade and in the immediate vicinity of the first doctor blade. Further, the ink composition was supplied from the die head and the ink composition was scraped off by the first and second doctor blades. In Comparative Example 2, the ink composition and the ink reservoir were not sucked.

  After filling the groove of the light transmitting portion with the ink composition, the ink composition was irradiated with ultraviolet rays to cure the ink composition, thereby forming a light absorbing portion, and a contrast improving sheet of Comparative Example 2 was produced. .

(Comparative Example 3)
In Comparative Example 3, a contrast improving sheet was prepared using a scraping device different from that in Example 1 and Example 2.

<Scraping device>
The scraping device used in Comparative Example 3 had almost the same configuration as the scraping device used in Example 1, but the first doctor blade was not provided with a through-hole, and the spacer Were not provided with suction holes. The width of the first doctor blade and the second doctor blade was 1160 mm, and the width of the first doctor blade was the same as the width of the second doctor blade.

<Preparation of contrast improving sheet>
First, as in Example 1, the light transmissive part composition used in Example 1 was supplied onto a polyethylene terephthalate substrate (Toyobo Co., Ltd., A4300, thickness 100 μm, width 1400 mm) for light transmissive part. The composition was cured to form a light transmissive portion having a width of 1400 mm and having a plurality of grooves arranged on the surface.

  Next, using the scraping device of Comparative Example 3, the ink composition used in Example 1 was filled in the groove of the light transmitting portion. Specifically, 5 L so that the ink composition is uniformly supplied in the width direction of the light transmitting portion from the die head of the die coater while moving the light transmitting portion together with the substrate at a line speed of 10 m / min. The ink composition on the surface of the light transmission part was scraped off using the scraping device of Comparative Example 3 after that.

  The ink composition was supplied so that an ink reservoir was formed on the upstream side of the first doctor blade and in the immediate vicinity of the second doctor blade. In addition, while supplying the ink composition from the die head and scraping off the ink composition by the first and second doctor blades, a part of the ink reservoir is removed by an air suction cleaner through a suction hole provided in the weir. Aspirated. The used ink composition thus sucked was sent to a mixing tank by a pump and mixed with an unused ink composition in the mixing tank. Then, the mixed ink composition was sent to the die head through a filter by a pump, and again supplied from the die head to the surface of the light transmitting portion.

  After filling the groove of the light transmitting portion with the ink composition, the ink composition was irradiated with ultraviolet rays to cure the ink composition, thereby forming a light absorbing portion, and a contrast improving sheet of Comparative Example 3 was produced. .

Appearance Observation The appearances of the contrast enhancing sheets of Examples 1 and 2 and Comparative Examples 1 to 3 thus produced were observed to confirm the occurrence of filling unevenness and streak defects. The criteria for this evaluation were as follows.

(1) Uneven filling ○: Uneven filling was not confirmed.
Δ: Some filling unevenness was observed, but there was no practical problem.
X: Many filling irregularities were confirmed.

(2) Line defect ○: No line defect was confirmed.
Δ: Some streaks were confirmed, but there was no practical problem.
X: Many streak defects were confirmed.

表１に示されるように比較例１に係るコントラスト向上シートは充填ムラおよびスジ不良ともに抑制できなかった。また、比較例２および３に係るコントラスト向上シートにおいては、充填ムラおよびスジ不良が若干観察された。これに対し、実施例１および２に係るコントラスト向上シートには、充填ムラおよびスジ不良が観察されず、良好な状態であった。 The results will be described below.

As shown in Table 1, the contrast improving sheet according to Comparative Example 1 was unable to suppress both filling unevenness and streak defects. Further, in the contrast improving sheets according to Comparative Examples 2 and 3, some filling unevenness and streaks were observed. In contrast, the contrast improving sheets according to Examples 1 and 2 were in a good state with no filling unevenness and streak defects observed.

  From these results, when the ink composition that forms a through hole in the first doctor blade and enters the first doctor blade and the second doctor blade through the through hole is sucked, filling unevenness and streaks are obtained. It was confirmed that defects can be reduced.

  DESCRIPTION OF SYMBOLS 1 ... Light transmission part, 1a ... Surface, 1b ... Groove, 2 ... Base material, 3 ... Ink composition, 3a ... Ink reservoir, 4 ... Light absorption part, 5 ... Contrast improvement sheet | seat, 10, 90 ... Manufacturing apparatus, 30 ... Supplying device, 40, 100 ... Scraping device, 41 ... First scraping blade, 41a ... Tip, 41b ... Through hole, 42 ... Second scraping blade, 43 ... Suction mechanism, 44,101 ... Holder 47, holder body, 48, weir, 48a, 102a, 103a ... suction hole, 49, 102, 103 ... spacer, 60 ... ink circulation system.

Claims (11)

A scraping device used for the manufacture of a contrast enhancing sheet comprising a light transmitting part having a plurality of grooves arranged in parallel on the surface and a light absorbing part formed in the groove of the light transmitting part,
A first scraping blade having a through-hole at the tip for scraping off the ink composition supplied onto the surface from the surface of the light transmitting portion provided with a plurality of grooves on the surface;
A second scraper disposed at a predetermined interval from the first scraping blade and further scraping off the ink composition remaining on the surface of the light transmitting portion after scraping by the first scraping blade; Scraping blade,
A scraping device comprising: a suction mechanism that sucks the ink composition that has entered the space between the first scraping blade and the second scraping blade through the through hole. . A holder for holding the first scraping blade and the second scraping blade; the holder being provided at a holder main body and both ends of the holder main body; and from the first scraping blade And a weir protruding to the side of the scraping surface of the first scraping blade, the width of the first scraping blade is shorter than the width of the second scraping blade, and The scraping device according to claim 1 , wherein a suction hole communicating with the space is provided in the dam portion, and the suction mechanism sucks the ink composition through the suction hole . A holder for holding the first scraping blade and the second scraping blade is further provided, and the holder is disposed between the holder main body, the first scraping blade, and the second scraping blade. and a spacer that is, the are suction holes are provided in the spacer which communicates with the space, said suction mechanism sucks said ink composition through the suction holes, according to claim 1 Scraping device. The scraping device according to claim 2 , wherein one end of the suction hole is provided on a bottom surface of the dam portion. A light transmitting portion in which a plurality of grooves are arranged on the surface, an apparatus for producing a contrast enhancing sheet and a light absorbing portion formed in the groove of the light transmitting portion, one of the claims 1 to 4 An apparatus for producing a contrast improving sheet, comprising the scraping device according to claim 1. A method for producing a contrast-enhancement sheet, comprising: a light transmission part having a plurality of grooves arranged in parallel on a surface; and a light absorption part formed in the groove of the light transmission part,
An ink composition is continuously supplied to the surface of the light transmitting portion while moving a sheet-like light transmitting portion having a plurality of grooves arranged on the surface, and downstream of the ink composition supply position. The ink composition on the surface of the light transmission part is formed on the upstream side of the first scraping blade disposed in the vicinity of the first scraping blade and an ink reservoir made of the ink composition is formed. A filling step in which the first scraping blade and the second scraping blade disposed at a predetermined interval on the downstream side of the first scraping blade and the first scraping blade are scraped. Prepared,
The first scraping blade has a through hole at a tip portion of the first scraping blade, and the filling step includes the first scraping blade and the second scraping blade through the through hole. A method for producing a contrast-enhancing sheet, which is carried out while sucking the ink composition that has entered the space between the take-up blades. The method for producing a contrast enhancing sheet according to claim 6 , wherein the ink composition is sucked from an end portion in a width direction of the light transmitting portion. The method for producing a contrast-enhancing sheet according to claim 6 , wherein the ink composition is sucked from between the first scraping blade and the second scraping blade. The method for producing a contrast enhancing sheet according to any one of claims 6 to 8 , wherein the sucked ink composition is supplied again to the surface of the light transmission part. The method for producing a contrast enhancing sheet according to claim 9 , wherein the sucked ink composition is mixed with an unused ink composition and then supplied to the surface of the light transmission part. The method for producing a contrast-enhancing sheet according to claim 10 , wherein a mixing ratio between the sucked ink composition and the unused ink composition is 1: 4 to 4: 1.

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