JP2007272065A - Optical film and manufacturing method thereof - Google Patents

Abstract

The present invention provides an optical sheet having a function of allowing viewing angle control in a plurality of directions with a single sheet and a method for manufacturing the same.
An optical film of the present invention is an optical film for limiting a two-dimensional viewing angle, and is formed of a transparent resin that transmits visible light and is arranged in a two-dimensional manner. And a light control unit 6 disposed between the light transmission units.
[Selection] Figure 1

Description

  The present invention relates to an optical film and a method for producing the same, and more particularly to an optical film having functions such as viewing angle control and a method for producing the same.

  For display screens of mobile phones, ATMs of financial institutions, laptop PCs, portable game machines, etc., it is required to control the viewing angle for the purpose of preventing peeping. A prism sheet having a concavo-convex shape such as the like is used.

  Since such a prism sheet cannot sufficiently perform the viewing angle control in a plurality of directions with a single sheet, a plurality of sheets are required when viewing angle control in a plurality of directions, for example, vertical and horizontal directions is required. However, there is a problem that the number of parts and the thickness increase as a result.

  The present invention has been made in order to solve such a problem, and an object thereof is to provide an optical sheet having a function of performing viewing angle control in a plurality of directions with a single sheet and a method for manufacturing the same. Yes.

  According to the present invention, a two-dimensional viewing angle limiting optical film, which is formed of a transparent resin that transmits visible light and is arranged two-dimensionally, There is provided an optical film comprising a light control unit disposed therebetween.

  According to such a configuration, light emission can be controlled in a plurality of directions by the light control unit provided around the light transmission unit.

According to the other preferable aspect of this invention, the said light control part contains the material which absorbs visible light.
An example of such a material is a solvent mixed ink.

According to another preferred aspect of the present invention, the light control unit includes a material that scatters visible light.
An example of such a material is a solvent mixed resin.

According to another preferred aspect of the present invention, the light control unit has a refractive index different from that of the light transmission unit.
According to another preferred aspect of the present invention, the light control unit has a higher refractive index than the light transmission unit.

According to another preferred aspect of the present invention, a refractive index of the light control unit is lower than a refractive index of the light transmission unit.
The refractive index of the light control unit is, for example, 0.05 or more, preferably 0.1 or more, more preferably 0.15 or more, and most preferably 0.2 or more than the refractive index of the light transmission unit.
According to another preferred embodiment of the present invention, the low refractive material is air.

  According to another preferred aspect of the present invention, the side surface of the light transmission part is roughened so as to scatter visible light.

According to another preferred aspect of the present invention, at least one of the light transmission part and the light control part is formed of an energy ray curable resin.
According to another preferred aspect of the present invention, the light transmission parts are regularly arranged.

  According to another preferred aspect of the present invention, the light transmission portion has a column shape. If the cross-sectional shape is different from the pixel shape of the liquid crystal panel such as a triangle, hexagon, or circle, moire fringes are less likely to occur when combined with the liquid crystal panel.

According to another preferred aspect of the present invention, the light transmission part has a truncated pyramid shape.
The inclined surface of the truncated pyramid shape has an angle with the normal line of the optical film of 0 to 45 degrees, preferably 0 to 30 degrees, more preferably 0 to 20 degrees, and most preferably 0 to 10 degrees. The smaller this angle, the greater the viewing angle limiting effect.

According to another preferred embodiment of the present invention, the average width of the light control unit in the optical film plane is 50 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and most preferably 10 μm or less.
If the width of the light control section is larger than necessary, the transmitted light window is reduced, resulting in a dark display. On the other hand, if the width is too small, the manufacture is difficult and a sufficient peep prevention effect cannot be obtained.

According to another preferred aspect of the present invention, the pitch or interval of the light transmission parts is 100 μm or less. This pitch is preferably 60 μm or less, more preferably 30 μm or less, and most preferably 20 μm or less.
When this pitch is increased, moire fringes are likely to occur when combined with a liquid crystal panel and the optical quality is lowered. However, the above range is preferable because moire fringes are less likely to occur when combined with a liquid crystal panel.

  According to another preferred embodiment of the present invention, the light transmission portion has a height / width ratio α of 1.0 to 5, more preferably 1.5 to 3.

According to another preferred aspect of the present invention, the light transmission part has a rotationally symmetric shape.
According to such a configuration, moire fringes are less likely to occur when combined with a liquid crystal panel.

According to another preferred aspect of the present invention, the plurality of light transmission parts have annular shapes with different diameters and are arranged concentrically.
According to such a configuration, moire fringes are less likely to occur when combined with a liquid crystal panel.
According to another preferred aspect of the present invention, the light transmission part and the light control part are arranged in a sea-island shape.

  According to another preferred embodiment of the present invention, the plurality of domains constituted by the optical film according to any one of claims 1 to 17 are continuous or discrete so as to form a desired pattern. There is provided a privacy film for a display, which is arranged in a dispersed manner.

According to such a configuration, peeping can be prevented by partially covering the display with the optical film. Moreover, as a desired pattern, various designs such as a company logo and an animation character can be adopted. According to such a structure, the design effect by such a pattern is show | played.
In addition, since it is possible to prevent peeping by simply covering a part of the display with an optical film, the size of the mold for manufacturing the optical film is smaller than the area of the display, and the mold manufacturing cost is reduced. Is done.
Further, when combined with a liquid crystal panel, generation of moire fringes is avoided.

  According to another preferable aspect of the present invention, a total area ratio of the plurality of domains to a total display area of the display is 30 to 100%.

According to another preferred embodiment of the present invention, a light absorbing substance is contained in a portion where the domain is not disposed.
According to such a configuration, since the front luminance may decrease in the portion where the domain is arranged, the luminance of the portion where the domain is not arranged is reduced, and the luminance of the portion where the domain is arranged is reduced. The difference has been reduced and the difficulty in viewing the display has been eliminated.

  According to another aspect of the present invention, there is provided a viewing angle limiting optical film, which is formed of a flat film base formed of a transparent resin that transmits visible light and a material that diffuses visible light. There is provided an optical film comprising a plurality of light diffusion portions arranged on a base.

  According to the other preferable aspect of this invention, the said light-diffusion part is regularly arranged on the said film base.

According to another preferred aspect of the present invention, the light diffusion portions are arranged in a grid pattern on the film base.
According to another preferred aspect of the present invention, the light diffusion portion has a substantially quadrangular pyramid shape.

  According to another aspect of the present invention, there is provided an optical film manufacturing method using a first mold having a window that constitutes at least a part of a cavity and transmits an energy ray emitted from an energy ray source. Forming a plurality of light transmitting portions formed of a transparent energy ray curable resin that transmits visible light on a flat base portion formed of a transparent resin that transmits visible light by injection molding; and a cavity Forming a light control part between the light transmission parts by injection molding using a second mold that has at least a part of the window and has a window that transmits energy rays emitted from an energy ray source. And a step of curing the filled resin with energy rays. A method for producing an optical film is provided.

  According to another aspect of the present invention, there is provided an optical film manufacturing method using a first mold having a window that constitutes at least a part of a cavity and transmits an energy ray emitted from an energy ray source. Then, a plurality of light transmitting portions formed of a transparent energy ray curable resin that transmits visible light are injection-molded or pressed against a flat base portion formed of a transparent resin that transmits visible light. There is provided a method for producing an optical film, comprising: a step of forming a light control unit; and a step of forming a light control unit between the light transmission units.

  According to another preferred aspect of the present invention, in the step of forming the light control unit, a fluid energy ray curable resin or solvent-mixed resin material that absorbs or scatters visible light is used as the plurality of light transmission units. A step of scraping off the excess material with a squeegee while filling from the base portion and the back surface between the step and a step of curing the filled resin by an energy ray or solvent dry process. .

  According to another aspect of the present invention, there is provided a method for manufacturing an optical film, wherein a visible mold is formed using a mold that forms at least a part of a cavity and has a window that transmits energy rays emitted from an energy ray source. There is provided a method for producing an optical film, comprising a step of forming a plurality of light scattering portions by injection molding on a flat base portion formed of a transparent resin that transmits light.

  According to another aspect of the present invention, there is provided a method for producing an optical film, in which a first transparent resin that transmits visible light and a second resin that absorbs or scatters visible light are coextruded in a molten state. And forming a structure having a sea-island structure having a sea region of the second resin and an island region of the first resin, and thinly cutting the structure in a direction perpendicular to the co-extrusion direction. And a step of providing an optical film.

  According to another preferred aspect of the present invention, a stretching step for stretching the structure is provided prior to the cutting step.

  According to the present invention having such a configuration, an optical sheet having a function of allowing viewing angle control in a plurality of directions with a single sheet and a method for manufacturing the same are provided.

Hereinafter, the optical film 1 according to the first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of the optical film 1.
As shown in FIG. 1, the optical film 1 is filled (arranged) between a flat base portion 2, a plurality of light transmission portions 4 disposed on the base portion 2, and the light transmission portions 4. And an optical control unit 6.

  The base portion 2 is formed of a resin that transmits visible light, and the light transmitting portion 4 is formed of a transparent energy ray curable resin that transmits visible light. The light transmitting portions 4 have a substantially rectangular parallelepiped (square pyramid) shape that tapers upward at an angle of about 10 degrees, and are regularly arranged in a grid pattern on the base portion 2.

  The angle of the four-pyramidal inclined surface is 0 to 45 degrees with respect to the normal line of the optical film, preferably 0 to 30 degrees, more preferably 0 to 20 degrees, and most preferably 0 to 10 degrees. The smaller this angle, the greater the viewing angle limiting effect.

  A lattice-like region between the light transmission parts 4 is filled with an opaque material that does not transmit visible light, and a lattice-like light control part 6 is formed. This opaque material is an energy ray curable resin to which a coloring material that absorbs visible light, such as carbon black and solution mixed ink, is added.

In the optical film of this embodiment, the light transmission part 6 has a width and a depth of about 30 μm and a height of about 40 μm, and the light control part 6 has a width of 10 μm.
In the optical film 1 of the present embodiment, the pitch of the light transmission portions 4 is 100 μm or less, preferably 60 μm or less, more preferably 30 μm or less, and most preferably 20 μm or less.

  In addition, the height / width ratio α of the rectangular parallelepiped light transmitting portion 4 is preferably set to 1.0 to 5, more preferably set to 1.5 to 3. As α is larger, the viewing angle can be limited to a narrow viewing angle.

Moreover, the average width in the optical film surface of the light control part 6 is 50 micrometers or less, More preferably, it is 30 micrometers or less, More preferably, it is 20 micrometers or less, Most preferably, it is 10 micrometers or less.
If the width of the light control unit 6 is too large with respect to the light transmission unit 4, the amount of light emitted in the front direction is reduced, so the above range is preferable.

  When the base portion is composed of a base film and an energy ray curable resin disposed thereon, for example, the base film has a thickness of about 50 μm and the energy ray curable resin layer disposed thereon has a thickness. The thickness of the base portion is about 60 μm.

  Next, a method for manufacturing the optical sheet 1 will be described. First, an injection molding apparatus 10 using an energy ray curable resin, which is an example of an apparatus used for manufacturing the optical sheet 1, will be described. FIG. 2 is a schematic drawing showing a schematic configuration of the injection molding apparatus 10.

  The injection molding apparatus 10 includes a mold 2, a metering injection mechanism 14 that measures and injects energy beam curable resin into the mold 2, and an energy beam source 16 that irradiates the mold 12 with energy beams. The mold 12 includes a metal fixed mold 12a and a metal movable mold 12b configured to reciprocate with respect to the fixed mold 12a, and a molded product is formed between the fixed mold 12a and the movable mold 12b. A cavity 18 corresponding to the shape is formed.

  The metering injection mechanism 14 includes a runner 20 disposed through the fixed mold 12 a so that one end communicates with the cavity 18, and a discharge device 22 that supplies a predetermined amount of energy beam curable resin to the other end of the runner 20. I have.

  The energy beam source 16 is disposed so as to irradiate the energy beam from the side opposite to the movable mold 12b toward the fixed mold 12a. In the present embodiment, the energy ray source 16 is a UV lamp having an emission peak wavelength in the range of 350 nm to 450 nm. However, depending on the type of energy ray curable resin to be used, UV lamps having other emission wavelengths, or other You may use what produces an energy ray. Other energy beam sources include lasers such as Ar ion lasers (488 nm, 514 nm) and YAG lasers (532 nm). The energy beam source 16 may be a UV light source that transmits short pulses.

  An optical system that collects, diffuses, or collimates the energy beam from the energy beam source 16 may be provided between the energy beam source 16 and the mold 12.

  An opening 24 is provided on the side surface of the energy beam source 16 of the movable mold 12 b of the mold 12, and a quartz glass plate 26 is attached to the opening 24, and the energy beam from the energy beam source 16 is transferred into the cavity 18 of the mold 12. A window to be introduced into is formed. The quartz glass plate 26 constitutes a part of the cavity.

  The opening 24 and the quartz glass plate 26 are set to dimensions and shapes so that the energy beam curable resin injected from the energy beam source 16 into the cavity 18 can be cured.

  A microstructure transfer mold 28 is attached to the bottom surface of the cavity 18 on the fixed mold 12 a side facing the quartz glass plate 26. The microstructure transfer mold 28 is a mold part on the surface of which a microstructure having a shape complementary to the light transmitting portion 4 of the optical film 1 is formed, and the microstructure is arranged facing the cavity 18 side. .

  A plurality of water pipes 30 are disposed on the back side of the microstructure transfer mold 28 and are configured to maintain the mold 12 at a predetermined temperature. Further, a shutter 32 that opens and closes the end of the runner 20 on the cavity 18 side is provided. Further, a gas vent hole 34 having a diameter of 10 μm or less is formed between the fixed mold 12a and the movable mold 12b.

  Further, the injection molding apparatus 10 is provided with a suction passage 38 in the quartz glass plate 26 for adsorbing the transparent base material 36 which becomes the base portion 2 of the optical film 1 to the surface of the quartz glass plate 26 on the cavity 18 side. Yes.

When the mold 2 is clamped, the injection molding apparatus 10 is several μm between the tip of the microstructure transfer mold 28 attached to the fixed mold 2a and the transparent base material 36 adsorbed and fixed to the movable mold 2b. Or the gap 40 of several tens of μm is formed. Therefore, in the injection molding apparatus 10, a large number of concave portions 42 complementary to the light transmitting portion 4 on the surface of the microstructure transfer mold 28 and the gaps of several μm to several tens of μm become the cavities 18.
For this reason, a large number of recesses 42 complementary to the light transmitting portion 4 on the surface of the microstructure transfer mold 28 communicate with each other through the gaps of several μm to several tens of μm at the time of mold clamping ( FIG. 3).
In the present embodiment, the recesses 42 have the same shape and are arranged in a grid pattern.

  In the method for manufacturing the optical sheet 1 according to the present embodiment, the transparent base material 36 is fixed to the movable mold 2b by suction, the mold 2 is clamped, and the transparent base material 36 is fixed to the movable mold 2b by suction. With the gap 40 of μm to several tens of μm formed, the energy ray curable resin is injected into the cavity 18 from the metering injection molding mechanism 4.

  As described above, a large number of concave portions 42 complementary to the light transmitting portion 4 on the surface of the microstructure transfer mold 28 communicate with each other through the gap 40 of several μm to several tens of μm at the time of mold clamping. As schematically shown in FIG. 3, the energy beam curable resin flows into the concave portions 42 complementary to the light transmitting portions 4 on the surface of the microstructure transfer mold 28 through the gaps 40 and fills them.

  After that, by operating the UV lamp of the energy beam source 16 for a predetermined time, the energy beam curable resin in the cavity 18 (the gap 40 and the recess 42) is irradiated with UV through the quartz glass plate 26 to cure the energy beam curable resin. Thus, a molded product 44 (FIG. 4) in which a plurality of light transmission portions 4 are regularly arranged in a grid pattern on the base portion 2 (transparent substrate 36). Thereafter, the mold 12 is opened and the molded product 44 is removed from the mold 12.

Next, the molded product 44 is attached to an injection molding apparatus similar to the injection molding apparatus 10 in which the planar mold 46 is disposed in place of the microstructure transfer mold 28, and carbon black is placed in a lattice-like space between the light transmitting portions 4. An energy ray curable resin material 48 that absorbs visible light including the like is filled (FIG. 5).
Next, the UV lamp of the energy beam source 16 is operated for a predetermined time, the opaque energy beam curable resin is cured, and the optical sheet 1 (FIG. 1) in which the light control unit 6 is disposed between the light transmission units 4 is obtained.
The surface of the optical sheet 1 formed in this way is polished as necessary.

In the step of forming the light control unit 6, an opaque resin is poured on the molded product 44, and this opaque resin (visible light absorbing resin) is pushed into the space between the light transmitting units 4 with a squeegee or the like to scrape excess resin. You may go by the method of taking.
When solvent mixed ink is used as the opaque resin, it is dried by a dry process after the filling process. When an opaque UV curable resin is used as the opaque resin, the UV curable resin is pushed in with a squeegee. Thereafter, the UV curable resin is cured with ultraviolet rays.

  In the optical film of the first embodiment, a material that absorbs visible light is included in the light control unit 6, but a configuration in which a material that disperses visible light is included in the light control unit, or light control. The part 6 may have a refractive index different from that of the light transmission part 4.

  As a material (dispersing material) for dispersing visible light, an average particle size of about 0.5 to 10 μm, preferably 6 μm or less, most preferably 2 μm or less, organic matter diffusion material such as polystyrene, silicone resin, inorganic silica diffusion material, -Diffusion fine particles.

  As a configuration in which the light control unit 6 has a refractive index different from that of the light transmission unit 4, there is a configuration in which a substance having a higher or lower refractive index than the light transmission unit 4 is disposed between the adjacent light transmission units 4.

As a configuration in which the refractive index of the light control unit 6 is lower than the refractive index of the light transmission unit 4, the refractive index of the light control unit 6 is, for example, 0.05 or more, preferably 0.1 or more, more preferably 0.15. Above, most preferably. 2 or lower. Moreover, the structure which utilizes air as a substance which comprises the light control part 6, ie, makes the space between the adjacent light transmission parts 4 into an air layer may be sufficient.
At this time, it is preferable to roughen the side surface of the light transmitting portion 4 of the truncated pyramid. According to such a configuration, since the side surface is roughened, strong scattering occurs at the interface with the air, and the viewing angle limiting function is achieved.

  From the viewpoint of the strength of the light transmission part 4, the distance between the light transmission parts 4 is preferably as small as possible. The distance at the bottom of the light transmission part 4 of the truncated pyramid is preferably 30 μm or less, more preferably 20 μm or less, most preferably Preferably it is 10 micrometers or less.

  In such a configuration, the light in the perspective direction emitted from the optical sheet between the light transmitting portions 4 of the adjacent truncated pyramid is scattered by the roughened side surface of the light transmitting portion 4 of the truncated pyramid. The light in the oblique direction with a large angle is blocked.

  Further, a visible light absorbing material may be coated on the side surface of the light transmitting portion 4 of the square frustum. At this time, in order to bring the visible light absorbing material into close contact with the side surface of the light transmitting portion 4, it is more convenient to coat from the rough surface, and there is an optically matt effect, which is preferable. Moreover, in order to improve the adhesiveness of a visible light absorber, plasma treatment etc. may be given to the side surface of the light transmissive part 4, and chemical adhesiveness may be improved.

Next, the optical film 50 of 2nd Embodiment of this invention is demonstrated. FIG. 6 is a schematic perspective view of the optical film 50.
As illustrated in FIG. 6, the optical film 50 includes a flat base portion 52 and a plurality of light diffusion portions 54 disposed on the base portion 52. The base portion 52 is formed of a transparent resin that transmits visible light. The light diffusing portions 54 are made of energy ray curable resin containing a diffusing material, have a quadrangular pyramid shape, and are regularly arranged on the base portion 52 in a grid pattern.

In the optical film 50 of the present embodiment, the pitch of the arranged light diffusion portions 54 is 100 μm or less, preferably 60 μm or less, more preferably 30 μm or less, and most preferably 20 μm or less. The height / width ratio α of the light diffusing portion 54 is set to 1.0 to 5, preferably 1.5 to 3. As α is larger, the viewing angle can be limited to a narrow viewing angle.
If α is too large, the light diffusing portion 54 is weakened and easily broken, and if α is too small, a sufficient light shielding effect cannot be obtained, so the above range is preferable.

The optical film 50 having such a configuration is formed by a method similar to the step of forming the light transmission part 4 of the optical film 1.
That is, diffusion is performed by the injection molding apparatus 10 in the same manner as the step of forming the light transmission part 4 of the optical film 1 using the microstructure transfer mold 56 having a surface complementary to the light diffusion part 54 formed thereon. An energy ray curable resin having an action is injected onto the transparent base material 36 (FIG. 7), and the light diffusing portion 54 of a truncated pyramid arranged in a grid pattern is formed on the transparent base material 36 (base portion 52). .

  As in the case of the optical sheet 1, when the mold 12 is clamped, the injection molding apparatus 10 is transparent to the tip of the microstructure transfer mold 56 attached to the fixed mold 12a and to the movable mold 12b. A gap 58 of several μm to several tens of μm is formed between the substrate 36 and the substrate 36.

  Therefore, the transparent base material 36 is attracted and fixed to the movable mold 12b and the mold 12 is clamped, and a gap 58 of several μm to several tens of μm is formed between the transparent base material 56 and the movable mold 12b. In this state, when the energy ray curable resin is injected from the metering injection molding mechanism 14, the injected energy ray curable resin passes through the gap 58, and the concave portion 60 complementary to the light transmitting portion 54 on the surface of the microstructure transfer mold 28. Meet.

  Next, the UV lamp of the energy ray source 16 is operated for a predetermined time to cure the energy ray curable resin, and the optical sheet 50 (FIG. 6) is obtained.

Next, the optical film 70 of 3rd Embodiment of this invention is demonstrated. FIG. 8 is a schematic front view showing the configuration of the optical film 70.
As shown in FIG. 8, the optical film 70 is filled between the flat base portion 72, a plurality of annular light transmission portions 74 disposed concentrically on the base portion 72, and the light transmission portions 74. (Arranged) light control unit 76.

  The base portion 72 is formed of a resin that transmits visible light, and the light transmitting portion 74 is formed of a transparent energy ray curable resin that transmits visible light. The light control unit 76 is formed of a resin containing a material that absorbs or diffuses visible light.

  The optical film 70 having such a configuration is manufactured by, for example, injection molding similar to that of the first embodiment.

Next, the optical film 80 of 4th Embodiment of this invention is demonstrated. FIG. 9 is a schematic front view showing the configuration of the optical film 80.
As shown in FIG. 9, the optical film 80 is formed around a transparent light transmitting portion 82 formed of a transparent resin that transmits visible light and arranged in a grid pattern, and around the light transmitting portion 82. It has a so-called sea-island structure including a light control unit 84 formed of a resin containing a material that absorbs or diffuses visible light.

  The optical film 80 having such a configuration is manufactured by, for example, co-extrusion of two kinds of resins using a spinneret as described in FIG. 4 of JP-A-2002-107552.

  First, a first transparent resin that transmits visible light and a second resin that absorbs or scatters visible light in a molten state as described in FIG. 4 of the above-mentioned JP-A-2002-107552. By co-extrusion with a spinneret, a structure having an island-island structure having an island region (light transmission portion 82) made of the first resin and an ocean region (light control portion 84) made of the second resin is obtained.

  Next, this structure is thinly cut in a direction perpendicular to the co-extrusion direction to obtain an optical film 80 having a configuration as shown in FIG. Prior to the cutting step, a structure formed by coextrusion may be stretched.

  Next, a display privacy film 90 according to another embodiment of the present invention will be described. FIG. 10 is a schematic front view for explaining the configuration of the privacy film 90.

  In the privacy film 90, a plurality of domains 94 constituted by the optical films of the first to fourth embodiments are formed on a transparent sheet 92 that transmits visible light, and a desired pattern (in FIG. 10, a square is enclosed). The characters “MRC”) are continuously or discretely distributed. The total area ratio of the plurality of domains 94 to the entire display area of the display, that is, the surface of the transparent sheet 92 is 30 to 100%. Further, the portion of the transparent sheet 92 where the domain 94 is not disposed contains a light absorbing material.

  The energy ray curable resin used in the injection molding is not particularly limited as long as it is cured by the energy rays used in the injection molding apparatus and has the necessary optical performance after curing, for example, The raw materials such as are mixed and used.

A resin raw material 1 which is a rigid component and represented by Chemical Formula 1.

Resin raw material 2 which is a rigid component and represented by Chemical Formula 2.

Resin raw material 3 which is a flexible component and represented by Chemical Formula 3.

Resin raw material 4 which is a flexible component and is represented by Chemical Formula 4.

Resin raw material 5 which is a flexible component and represented by Chemical Formula 5.

Resin raw material 6 represented by Chemical Formula 6 which is a flexible component.

A UV initiator 7 represented by Chemical Formula 7.

  Resin raw material 8 obtained by adding 4 mol EO to resin raw material 5.

  A resin raw material 9 which is a rigid component and has a structure in which an aromatic ring of the resin raw material 5 is hydrogenated.

Resin raw material 10 which is a rigid component and is a urethane acrylate mixture comprising the following components A and B.
A component: trimer of hexamethylene diisocyanate + hexamethylene diisocyanate B component: hydroxypropyl acrylate + pentaerythritol triacrylate

  In the present invention, the produced polymer has a glass transition temperature (Tg) of 40 ° C. or higher, preferably 60 ° C. or higher, more preferably 80 ° C. or higher.

  Examples of the raw material for producing such a polymer include those represented by the following chemical formulas 8 to 2.

  As the energy ray curable resin component, at least the glass transition temperature (Tg) of the polymer is 40 ° C. or higher, preferably 70 ° C. or higher, more preferably 90 ° C. or higher, and most preferably 110 ° C. or higher. The

  Further, when at least trifunctional acrylate is used as a component of the energy ray curable resin, the polymerization curing reaction is fast, the rigidity of the film is increased, and Tg is also increased.

When an acrylate monomer having two or more, preferably 3 to 6, acryloyl groups in the molecule is used, the polymerization and curing reaction is fast, and the rigidity and Tg of the film are increased.
Inclusion of an alicyclic bifunctional acrylate in the molecule increases the rigidity and Tg of the film.

When an acrylate containing a large amount of polar groups is included, optical anisotropy can be imparted as a characteristic of the film.
When an acrylate containing a fluorine atom is included, an optical film having optical anisotropy can be produced by polling and photocuring the film by applying a high electric field to the film. In addition, the compatibility with the resin of the metal and other transparent windows becomes poor, and the peeling from the mold becomes easy.

  When an epoxy acrylate is included, it is less susceptible to oxygen inhibition during curing and has excellent adhesion to metal. Conveniently, a polymer is taken in the metal mold, and it is difficult to adhere to the glass / transparent resin when the mold is opened, and the peeling direction is always the metal mold surface. Peeling from the metal surface is performed with a blow.

Urethane acrylate and imide acrylate may be used as the diluent.
{Urethane acrylate comprising {hexamethylene diisocyanate / hexamethylene diisocyanate trimer mixture} and / or {hydroxypropyl acrylate / pentaerythritol triacrylate mixture} components A rate mixture may be used.

As an initiator, a UV initiator may be used in combination with a sensitizer, and polymerization may be performed using an energy sensitization reaction. The photosensitive wavelength is extended to improve deep curing.
For example, ITX (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one Irgacure907 initiator: Ciba Specialty Chemicals Co., Ltd. may be used in combination.

When a photopolymerization initiator having an absorption peak in a long wavelength region of 360 nm or longer is used as the UV initiator, the photosensitive wavelength is increased and the deep curing is improved.
For example, BAPO {bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide}, MBAPO {2,4,6-trimethylbenzoyl-diphenylphosphine oxide} can be mentioned.

When a photopolymerization initiator having photo-fading properties is used as the UV initiator, the absorption band of the initiator disappears with the photoreaction, and the light reaches deeper and the curing reaction proceeds further.
For example, acylphosphine oxide: MBAPO {2,4,6-trimethylbenzoyl-diphenylphosphine oxide}, titanocene initiator: bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6 -Difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, oxime ester: OXE {1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime )]}.

When a polymerization initiator that can be used in irradiation with visible light energy rays is used, polymerization can be started by irradiation with visible light, so that a laser can be used as an energy ray source.
For example, there is a titanocene initiator: bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl).

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.
In each said embodiment, although the shape of each light-diffusion part 54 of each light-control part 4 was the same, the shape and dimension of each light-control part may be random. Moreover, in the said embodiment, although each light control part 4 and the light-diffusion part 54 were arrange | positioned regularly, you may arrange | position these at random.

  In the above embodiment, each light transmission part 4 is formed by injection molding on the transparent base material 36 that becomes the base part 2, but the base part is not used at the same time without using the transparent base material 36. 2 may be formed by injection molding. Thus, when the whole base part is comprised with energy-beam curable resin without using a transparent base material, the thickness of a base part shall be about 20 micrometers, for example. In this case, an energy ray curable resin having a high strength is selected.

  In the optical film 1 of the first embodiment, the light transmission part 4 has a quadrangular pyramid shape, but the light transmission part 4 may have another shape, for example, a prism such as a triangular prism or a hexagonal prism, or a cylinder. Good. Such a shape is preferable because moire fringes are less likely to occur when combined with a liquid crystal panel.

  Soft silicone resin (rubber), soft acrylic cross-linkage using weak adhesive or self-adsorptive (properly sticking to a smooth surface) material such as a material having a low glass transition temperature on one surface of the optical film An adhesive layer containing an adhesive resin, a soft polyethylene resin, or the like may be formed. In particular, the self-adsorptive material can be desorbed many times unlike ordinary adhesives, and the optical sheet can be removed from the display when unnecessary.

  Moreover, the apparatus which injection-molds a light control part or each light-diffusion part etc. is not limited to the said apparatus.

  Moreover, you may form a light transmissive part by pressing a metal mold | die.

It is a typical perspective view of the optical film of 1st Embodiment of this invention. It is typical drawing which shows schematic structure of the injection molding apparatus which is an example of the apparatus used for manufacture of the optical sheet | seat of FIG. It is typical sectional drawing explaining the process of manufacturing the optical sheet of FIG. 1 with the injection molding apparatus of FIG. It is a perspective view of the molded article formed in the manufacturing process of the optical sheet of FIG. It is typical sectional drawing explaining the process of manufacturing the optical sheet of FIG. 1 with the injection molding apparatus of FIG. It is a typical perspective view of the optical film of 2nd Embodiment of this invention. It is typical sectional drawing explaining the process of manufacturing the optical sheet of FIG. 6 with the injection molding apparatus of FIG. It is a typical front view which shows the structure of the optical film of 3rd Embodiment of this invention. It is a typical front view which shows the structure of the optical film of 4th Embodiment of this invention. It is a typical front view of the privacy film for displays which is other embodiments of the present invention.

Explanation of symbols

1: Optical film 2: Base part 4: Light transmission part 6: Light control part

Claims (30)

An optical film for limiting a two-dimensional viewing angle,
A plurality of light transmitting portions formed of a transparent resin that transmits visible light and arranged two-dimensionally;
A light control unit disposed between the light transmission units,
An optical film characterized by the above. The light control unit includes a material that absorbs visible light,
The optical film according to claim 1. The light control unit includes a material that scatters visible light,
The optical film according to claim 1. The light control unit has a refractive index different from that of the light transmission unit;
The optical film according to claim 1. The light control unit has a higher refractive index than the light transmission unit,
The optical film according to claim 4. The refractive index of the light control unit is lower than the refractive index of the light transmission unit,
The optical film according to claim 4. The low refractive material is air;
The optical film according to claim 6. The side surface of the light transmission part is roughened to scatter visible light,
The optical film according to claim 1. At least one of the light transmission part and the light control part is formed of an energy ray curable resin,
The optical film according to claim 1. The light transmission parts are regularly arranged,
The optical film according to claim 1. The light transmission part is columnar,
The optical film according to claim 2. The light transmission part has a truncated pyramid shape,
The optical film according to claim 1. The pitch of the light transmission parts is 100 μm or less,
The optical film according to claim 1. The light transmission portion has a height / width ratio α of 1.0 to 5,
The optical film according to claim 1. The light transmission part has a rotationally symmetric shape;
The optical film according to claim 1. The plurality of light transmission portions have annular shapes with different diameters and are arranged concentrically.
The optical film according to claim 15. The light transmission part and the light control part are arranged in a sea island shape,
The optical film of any one of Claims 1 thru | or 14.   A plurality of domains constituted by the optical film according to any one of claims 1 to 17, wherein the domains are arranged in a continuous or discrete manner so as to form a desired pattern. Privacy film. The total area ratio of the plurality of domains to the total display area of the display is 30 to 100%.
The privacy film according to claim 18. The portion where the domain is not arranged contains a light absorbing material,
The privacy film according to claim 19. An optical film for limiting the viewing angle,
A flat film base formed of a transparent resin that transmits visible light;
A plurality of light diffusion portions formed of a material that diffuses visible light and disposed on the film base,
An optical film characterized by the above. The light diffusion portions are regularly arranged on the film base,
The optical film according to claim 21. The light diffusion portions are arranged in a grid pattern on the film base,
The optical film according to claim 22. The light diffusion part has a substantially square frustum shape,
The optical film according to any one of claims 21 to 23. An optical film manufacturing method comprising:
On a flat base portion formed of a transparent resin that transmits visible light using a first mold that forms at least a portion of the cavity and has a window that transmits energy rays emitted from an energy ray source Forming a plurality of light transmitting portions formed of a transparent energy ray curable resin that transmits visible light by injection molding;
The light control unit is formed by injection molding between the light transmission parts by using a second mold that forms at least a part of the cavity and has a window that transmits the energy rays emitted from the energy beam source. Steps,
Curing the filled resin with energy rays,
The manufacturing method of the optical film characterized by the above-mentioned. An optical film manufacturing method comprising:
On a flat base portion formed of a transparent resin that transmits visible light using a first mold that forms at least a portion of the cavity and has a window that transmits energy rays emitted from an energy ray source Forming a plurality of light transmission parts formed of a transparent energy ray curable resin that transmits visible light by injection molding or pressing a mold;
Forming a light control unit between the light transmission units,
The manufacturing method of the optical film characterized by the above-mentioned. Forming the light control unit comprises:
Excessive material is scraped off with a squeegee while filling a fluid energy ray curable resin or solvent-mixed resin material that absorbs or scatters visible light from the base portion and the back surface between the plurality of light transmitting portions. Steps,
And curing the filled resin by an energy ray or solvent dry process.
The method for producing an optical film according to claim 26. An optical film manufacturing method comprising:
On a flat base portion made of a transparent resin that transmits visible light, a plurality of molds having at least a part of the cavity and having a window that transmits energy rays emitted from an energy ray source are formed on the flat base portion. A step of forming the light scattering portion of the substrate by injection molding,
The manufacturing method of the optical film characterized by the above-mentioned. An optical film manufacturing method comprising:
The first transparent resin that transmits visible light and the second resin that absorbs or scatters visible light are co-extruded in a molten state, and the sea region of the second resin and the island of the first resin are Forming a structure with a sea-island structure having a region;
Cutting the structure thinly in a direction perpendicular to the co-extrusion direction,
The manufacturing method of the optical film characterized by the above-mentioned. Prior to the cutting step, comprising a stretching step of stretching the structure,
30. A method for producing an optical film according to claim 29.

Images