JP2009210834A - Light beam control member and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light beam control member excellent in handling while preventing curling and having a fine unevenness structure with a large area and a high aspect ratio, and to provide a method of manufacturing the light beam control member with high productivity. <P>SOLUTION: The light beam control member includes a light-transmitting part and a plurality of light-absorbing parts disposed parallel to one another at a predetermined interval on one surface of the light-transmitting part, wherein the light beam control member contains a vinyl ester composition and the light-transmitting part has a single layer structure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is installed on the front of the display, and the display performance, in particular, the function of preventing the deterioration of image quality due to the decrease in contrast when external light hits the display, the effective angle of the display, and the viewing angle are suitably diffused. The present invention relates to a light beam control member having a function of widening the width, and a method for manufacturing the same.

  In recent years, thin and large-screen displays have rapidly expanded the market. Thin, large-screen displays include liquid crystal displays, plasma displays, rear projection televisions, and the like. Further, as next-generation displays, research on organic EL displays or FEDs (Field Emission Displays) is also progressing.

  The technology of both displays is remarkable, and the drawbacks of each method are resolved year by year. Contrast is represented by the ratio of the brightness of white display to black display.

  The contrast in the absence of external light (dark place contrast) is high for self-luminous plasma displays, organic EL displays, and the like. This is because complete black display is possible by stopping the light emission.

  On the other hand, the photopic contrast is higher for liquid crystal displays. This is because an optical member that absorbs light, such as a color filter and a polarizing plate, is provided inside the display, and external light incident on the display is hardly emitted from the display surface again.

  On the other hand, the disadvantage of low contrast in a bright room (light contrast) has much room for improvement in plasma displays, organic EL, and the like. In a plasma display or organic EL, there is generally no color filter or polarizing plate inside the display, and incident external light enters the display, is reflected by internal electrodes, etc., and is emitted from the display surface again. Since it cannot be displayed, the contrast in the light place is lowered.

  In order to solve such a problem, in recent years, a display filter including a light beam control member in which a plurality of light absorbing portions are arranged in a stripe shape has been proposed in order to suppress a decrease in contrast due to external light ( For example, Patent Documents 1, 2, and 3).

  The light control members disclosed in Patent Documents 1 to 3 are each made of an ionizing radiation curable resin provided with a support layer made of a transparent plastic such as PET (polyethylene terephthalate), a light transmission part, and a light absorption part. A two-layer structure with the substrate. The two-layer structure is due to the fact that the substrate does not have self-supporting properties.

  When the light beam control member is used for a filter layer of a display or the like, in many cases, a filter having other functions in a subsequent process, for example, antireflection, electromagnetic wave shielding, near infrared absorption filter, or the like is bonded to form a filter with integrated functions. For this reason, in addition to the light beam control function such as contrast improvement, there is a demand for less curling as a good handling property.

  The ionizing radiation curable resin contracts due to the ionizing radiation irradiated when the substrate is formed. At this time, in the light control member having a two-layer structure, a contraction difference is generated between the support layer and the substrate, and an internal stress is generated. This internal stress causes curling. For this reason, it is desired that the light beam control member has a single-layer structure.

In particular, Patent Document 1 discloses that
Example 2 First Layer Thickness D1 = 0.6 mm
Second layer thickness D2 = 0.03 mm
Polyester film thickness 0.1mm "
It is described. Here, the first layer refers to the light beam control unit, and the second layer refers to the adhesive layer, and the total thickness is 0.73 mm. Thus, the light beam control member obtained in Patent Document 1 has a thick film thickness of each component. Thus, since the film thickness of a component is thick, internal stress becomes large in each internal structure. For this reason, it causes a curl.

  In addition, a light control member used for a display is required to have a fine concavo-convex structure having a large area and a high aspect ratio. For example, in Patent Document 2, as a method for manufacturing a light control member, “a base layer 12a is prepared (FIG. 5A)”, and a light transmitting portion 12b is formed on one side using an ultraviolet curable resin (FIG. 5). (B)) The light transmitting portion 12b is formed by irradiating ultraviolet rays in a state where an ultraviolet curable resin is sandwiched between the roll mold having the inverted shape of the light transmitting portion 12b and the base layer 12a. Is done. "

  Patent Document 4 discloses a method of forming stripe-shaped grooves in a film. Specifically, the ionizing radiation curable resin is supplied between the film substrate and the roll intaglio and then pressed, and this is irradiated with ionizing radiation to cure the ionizing radiation curable resin. Next, the film base material is peeled from the intaglio to obtain a film having an uneven structure.

  However, when an ionizing radiation curable resin is cured on a normal mold roll in the case of making a fine concavo-convex structure, the specific surface area is increased as compared with the prior art, while the shape is thin and thin. For this reason, the peeling stress increases in proportion to the specific surface area, and the rigidity decreases in proportion to the size of the shape. Thereby, at the time of peeling from the roll, the molded body is often destroyed by the peeling stress and remains on the roll. As a result, there is a problem that it is difficult to continuously and stably manufacture a large-area film on which a fine concavo-convex structure is formed.

  Next, in the light beam control member, a light absorbing part is created by filling a light-absorbing substance such as a black substance on a film on which a fine uneven structure is formed. Japanese Patent Application Laid-Open No. 2004-228561 describes that “a solvent-based black ink is embedded as a light absorption layer in a groove portion by a wiping method” regarding the creation of a light absorption portion.

However, a release agent is applied to the surface of the metal roll to facilitate peeling of the film. In the case of creating a light-absorbing portion having a fine structure, the release agent is transferred to the molded body at the time of peeling from the metal roll. For this reason, when the light absorbing part material is filled in the molded body, the light absorbing part material is repelled, and the filling of the light absorbing part material into the fine structure tends to be insufficient.
JP 2004-62084 A JP 2006-201577 A JP 2006-189867 A Japanese Patent No. 2811000

  Therefore, the present invention solves the above-mentioned problems, suppresses curling, has excellent handling, and has a light control member having a fine concavo-convex structure having a large area and a high aspect ratio, and manufacturing this light control member with high productivity. An object of the present invention is to provide a manufacturing method.

  In order to solve the above-mentioned problems, the present inventors have intensively studied and as a result, completed the following invention.

  (1) In this invention, the vinyl ester composition was used as a material of a light control member. The cured product of the vinyl ester composition has a self-supporting property. As a result, the light transmission part of the light control member can have a single layer structure. Thereby, the light beam control member of the present invention does not have a two-layer structure of the support layer and the substrate made of ionizing radiation curable resin provided with the light transmission part and the light absorption part. Therefore, the generation of internal stress can be reduced.

  Moreover, the light beam control member of the present invention has self-supporting properties even if the total thickness in the light transmission direction is reduced. As a result, the internal stress that is the direct cause of curling can be reduced.

  (2) The light control member of the present invention uses a vinyl ester composition, which is a material having moderate flexibility, in which the molded body is not easily broken by peeling stress when peeled from the roll and hardly remains on the roll. Thereby, the structure of the light absorption part can be miniaturized while maintaining the opening / thickness ratio. As a result, a light control member having a fine concavo-convex structure having a large area and a high aspect ratio can be obtained.

  (3) The manufacture of the light control member of the present invention uses a mold using a material that does not require a mold release treatment on the mold surface. Accordingly, the film can be easily peeled off from the mold surface, and the light absorbing portion material is not repelled when the light shielding portion material is filled. As a result, the fine structure is sufficiently filled with the light absorbing portion material. That is, a large area can be stably manufactured continuously with a light control member having a fine concavo-convex structure having a large area and a high aspect ratio.

  That is, the present invention is as follows.

  The light beam control member of the present invention is a light beam control member including a light transmission part and a plurality of light absorption parts arranged on a surface of the light transmission part in parallel with each other at a predetermined interval. The member contains a vinyl ester composition, and the light transmission part has a single layer structure.

  The light control member has a total thickness in the light transmission direction of 30 μm or more and 50 μm or less.

The light absorbing portion has a rectangular cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion, the height of the rectangle in the light transmitting direction of the light control member is h, and the rectangle in the surface direction of the light transmitting portion. Where w, w, and p satisfy the following equation.
α ≦ atan (p−w) / h ≦ θ (1)
α = 20 °, θ = 40 °

The light absorbing portion has a cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion other than a rectangle, the height of the shape in the light transmitting direction of the light control member is h, and the surface direction of the light transmitting portion When the width of the shape is w and the pitch of the plurality of light absorbing portions is p, the h, w, and p satisfy the following formula.
α ≦ atan (p−w / 2) / h ≦ θ (2)
α = 20 °, θ = 40 °

  The said vinyl ester composition contains the liquid oligomer and monomer which have a vinyl ester composition as the main component, and can be hardened | cured with an active energy ray.

  The light absorption part may contain a black pigment dispersion.

  The light control member manufacturing method of the present invention includes a step 1 of supplying a vinyl ester composition onto a substrate, a step 2 of pressing the substrate supplied with the vinyl ester composition against a mold, and the pressure contact Step 3 of curing the vinyl ester composition filled between the base material and the mold, Step 4 of peeling the molded body formed by the curing from the mold, and black in the recess formed on the molded body A method of manufacturing a light control member, comprising: a step 5 of filling a mixture of a material and a vinyl ester composition; a step 6 of curing the filled mixture; and a step 7 of peeling the molded body from a substrate. And the mold material which comprises the mold used by the said process 2 is a material whose new JIS K 6253 durometer type A spring type hardness is 35-65.

  The mold forming material constituting the mold may be a material having a contact angle with pure water of 100 degrees or more. The mold forming material constituting the mold is preferably polydimethylsiloxane.

The light control member of the present invention is composed of a vinyl ester composition and forms a light control member having a single layer structure. Since it is composed of a vinyl ester composition, a light control member having self-supporting properties can be obtained. As a result, it is possible to obtain a light beam control member with less product curling and excellent handling.
Moreover, a light control member is manufactured using the new JIS K 6253 durometer type A spring type | mold vinyl ester composition whose hardness is 35-65. Further, a mold using a mold forming material that easily peels the vinyl ester composition is used. As a result, a light control member having a fine concavo-convex structure having a large area and a high aspect ratio can be produced with high productivity.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(1) Shape of Light Control Member FIG. 1 is a schematic view of the light control member of the present invention observed from the light incident direction. FIG. 2 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of an embodiment of the light beam control member of the present invention. As shown in FIG. 1, the light beam control member of the present invention includes a light transmission part 1 and a light absorption part 2. The light absorbing parts 2 are arranged in one surface of the light transmitting part 1 in a balanced manner with a predetermined interval. As shown in FIG. 2, in the light beam control member of the present invention, the light transmission part 1 has a single layer structure.

  The light absorption unit 2 is one of an inclined surface, a vertical surface, a parallel surface, and a curved surface with respect to the surface of the light transmission unit 1 within the light transmission unit 1 from the bottom surface exposed from the surface of the light transmission unit 1 and the bottom surface. including. In the example of FIG. 2, it has a rectangular shape including a vertical surface or a parallel surface with respect to the surface of the light transmission portion 1. The light control member 1 is attached to the display with the light absorbing portion 2 facing outward. The light absorption unit 2 plays a role of preventing external environmental light from entering the display.

  In the cross section of the light absorbing member in the AA ′ direction in FIG. 1, the cross sectional shape perpendicular to the longitudinal direction of the light absorbing portion 2 is particularly limited as long as the bottom and the height within the light transmitting portion 1 can be specified. For example, it may be a rectangle shown in FIG. 2, a trapezoid shown in FIG. 3, a triangle shown in FIG. 4, an arc shape shown in FIG. 5, or a bell shape shown in FIG. In the case of a triangle, it may have a wedge shape in which the inclined surface is bent once. Alternatively, a form in which these figures are mixed (for example, a form in which an arc is formed on a rectangle) may be used.

  In the light control member of the present invention, the total thickness d in the light transmission direction is preferably 10 to 50 μm, more preferably 30 to 50 μm.

  Moreover, the height h of the light absorption part 2 is 5-50 micrometers, Preferably it should just be 10-30 micrometers.

  Moreover, the width w of the light absorption part 2 is 1-10 micrometers, Preferably it should just be 2-8 micrometers.

  Moreover, the pitch p of the light absorption part 2 is 5-50 micrometers, Preferably it should just be 5-30 micrometers.

  In the light beam control member of the present invention, the aspect ratio (h / w) of the light absorbing portion 2 is preferably in the range of 2 to 10, and more preferably in the range of 3 to 8. As described above, the light beam control member of the present invention is a light beam control member having a fine concavo-convex structure having a high aspect ratio. In calculating the aspect ratio when the shape of the light absorbing portion is not rectangular, the width w of the bottom portion (for example, the length of the longer side in a trapezoid) is used.

  Further, by setting the width w and the pitch p to appropriate values (the width w is 1 to 10 [mu] m and the pitch p is 5 to 50 [mu] m), even if the height h is 5 to 50 [mu] m, the contrast due to external light It is possible to realize a configuration in which the reduction is effectively suppressed and the luminance of the filter is not lowered by maintaining the transmittance of the filter.

  In the light beam control member of the present invention, the height of the light absorbing portion having a shape other than the rectangle or the rectangle in the light transmission direction is h, the width w of the shape other than the rectangle or the rectangle in the surface direction of the light transmission portion, and It is preferable that the pitch p of the plurality of light absorbing portions have the following relationship. Since the height h, the width w, and the pitch p of the light absorbing portion have the following relationship, it is possible to effectively suppress a decrease in contrast due to external light.

That is, it is preferable that the following relational expression (1) is satisfied when the cross-sectional shape of the light absorption part is rectangular, and the following relational expression (2) is satisfied when the cross-sectional shape of the light absorption part is a shape other than rectangular. Is preferred.
α ≦ atan (p−w) / h ≦ θ (1)
α ≦ atan (p−w / 2) / h ≦ θ (2)

  In the above formulas 1 and 2, α is preferably 20 degrees and more preferably 25 degrees from the viewpoint of securing the viewing angle. The angle θ is preferably 40 degrees and more preferably 35 degrees from the viewpoint of shielding external light. The light beam control member of the present invention aims to shield outside light. The light beam control member of the present invention has a structure in which light absorbing portions and light transmitting portions are alternately formed. It is assumed that external light is incident on the light transmission part obliquely from the observation side. The above formulas (1) and (2) are formulas representing which angle of light can enter or be shielded in that case. Since (p−w) in the equation (1) is the width of the light transmitting portion and h is the height, (p−w) / h is a slope of a straight line that crosses the light transmitting portion diagonally. Α and θ, which are the upper and lower limits of the angle range, mean angles that can secure a minimum viewing angle and shield external light. Moreover, in the formula (2), the reason why w / 2 is used is to compensate for the increase in the incident angle of the external light due to the light absorbing portion having a shape other than a rectangular shape such as a triangle.

  In the light beam control member of the present invention, at least h, w, and p of the cross-sectional shape of the adjacent light absorbing portions may satisfy the above formula 1 or formula 2. More preferably, h, w, and p of the cross-sectional shapes of all adjacent light absorbing portions may satisfy the above formula 1 or formula 2.

(2) Material used for light transmissive part The light transmissive part according to the present invention comprises a vinyl ester composition (a) as a main component, and if necessary, the following bifunctional or lower acrylate (b), photopolymerization start Agents and modifiers are used.

  Here, the vinyl ester composition (a) is defined as a vinyl ester that is a series of oligoacrylates that share a secondary hydroxyl group generated by a ring-opening reaction of an epoxy group and a (meth) acryloyl group in the same molecule. The vinyl ester composition (a) preferably used in the present invention is obtained by esterifying a bisphenol type or alicyclic epoxy compound with acrylic acid or methacrylic acid. Examples of the bisphenol type or alicyclic epoxy compound include the following.

  That is, a reaction product of bisphenol A and epichlorohydrin, a reaction product of bisphenol F and epichlorohydrin, a reaction product of hydrogenated bisphenol A and epichlorohydrin, a reaction product of cyclohexanedimethanol and epichlorohydrin, a reaction product of norbornane alcohol and epichlorohydrin , Reaction product of tetrabromobisphenol A and epichlorohydrin, reaction product of tricyclodecane dimethanol and epichlorohydrin, alicyclic diepoxy adipate, alicyclic diepoxy carbonate, alicyclic diepoxy acetal, alicyclic diepoxy Carboxylate and the like.

  In addition to the above vinyl ester composition, the following bifunctional or lower acrylate compound (b) can be used for the purpose of lowering the viscosity within the range not impairing the effects of the present invention.

  Examples of the bifunctional or lower acrylate compound which can be used include diallyl orthophthalate, diallyl isophthalate, diallyl terephthalate, diallyl 1,4-cyclohexanedicarboxylate and diallyl succinate as allyl ester monomers.

  As acrylic acid ester monomer and methacrylic acid ester monomer, methyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxylethyl methacrylate, 2-hydroxypropyl methacrylate, EO adduct dimethacrylate of bisphenol A, EO adduct di of bisphenol A Acrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, phenoxyethyl methacrylate, isobornyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, Trimethylolpropane diacri Chromatography, tri trimethylol propane dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, glycerol dimethacrylate, 2,6-dibromo -4-tert-butylphenyl acrylate, various urethane acrylate, and epoxy acrylate.

  When the light control member is UV-cured, a known photopolymerization initiator exemplified below can be used as the polymerization initiator. Specifically, 2,2-dimethoxy-1,2-digenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, bezophenone, 2-methyl-1- (4-methylthiophenyl) -2-monfoli Nopropanone-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,4 , 6-trimethylbenzoyldiphenyl-phosphine oxide and the like. Moreover, you may add a hardening accelerator as needed. In the case of electron beam curing, an initiator may not be used.

  The addition amount of the polymerization initiator may be 0.05 to 3 parts by weight, preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the above (a) + (b).

  The light transmitting part can further contain a modifier. As modifiers, coatability improvers, antifoaming agents, thickeners, antistatic agents, inorganic particles, organic particles, organic lubricants, organic polymer compounds, UV absorbers, light stabilizers, dyes, A pigment or a stabilizer can be used. These are used as a composition component of a coating layer that is formed within a range that does not impair the reaction caused by actinic radiation or heat, and the characteristics can be improved depending on the application.

(3) Material used for light absorbing portion The material used for the light absorbing portion of the present invention is mainly composed of a mixture of the vinyl ester composition and a black pigment dispersion. The following acrylates, polymerization initiators and modifiers may be mentioned.

Examples of the black pigment dispersion include carbon black, polymer dispersion of black metal particles such as titanium and iron, and the like. When the extinction coefficient of the black pigment dispersion is about 1 × 10 ⁶ m ⁻¹ , the content of the black pigment dispersion is 5 to 80 parts, preferably 10 to 50 parts by weight with respect to 100 parts by weight of the vinyl ester composition. It is desirable to set the range.

(4) Curing method of light absorption part and light transmission part The curing method of the light absorption part and light transmission part may be either crosslinking by heat or crosslinking by active energy rays. A method using active energy rays is preferable. Examples of the active energy rays include electromagnetic waves that polymerize acrylic vinyl groups such as ultraviolet rays, electron beams, and radiation (α rays, β rays, γ rays, etc.). Practically, ultraviolet rays are simple and more preferable. As the ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used. Moreover, when irradiating actinic radiation, if it irradiates under a low oxygen concentration, it can harden | cure efficiently. Furthermore, the electron beam method is advantageous in that the apparatus is expensive and operation under an inert gas is required, but it is not necessary to include a photopolymerization initiator or a photosensitizer in the coating layer. is there.

(5) Manufacturing method of light control member The manufacturing method of the light control member of the present invention includes [1] a step of supplying a vinyl ester composition on a substrate, and [2] a group supplied with the vinyl ester composition. A step of pressing the material against the mold, [3] a step of curing the vinyl ester composition filled between the pressed substrate and the mold, and [4] a molded body formed by the curing. [5] a step of filling a concave portion formed on the molded body with a mixture of a black material and a vinyl ester composition, [6] a step of curing the filled mixture, 7] A step of peeling the molded body from the substrate.

  The steps [1] to [4] will be described with reference to FIG. FIG. 7 is a schematic diagram for explaining a process of manufacturing the light transmission part.

  In FIG. 6, first, a vinyl ester composition, which is a light transmission part material, is supplied from a light transmission part material supply device 7 to the base material 6. As the substrate 6, it is preferable to use a plastic film. The kind of plastic film to be used is not particularly limited, and a plastic film composed of polyester, polyolefin, cyclic polyolefin, polyamide, triacetyl cellulose, acrylic, polyurethane, or the like can be preferably used. A polyester film is particularly preferable.

  Although it does not specifically limit as polyester of a polyester film, A polyethylene terephthalate, a polyethylene naphthalate, a polypropylene terephthalate, a polybutylene terephthalate, a polypropylene naphthalate, etc. are mentioned, These 2 types or more may be mixed.

  Further, the plastic film may be subjected to a surface treatment, and it is more preferable that a release treatment is applied in consideration of peeling of the base plastic in a subsequent process.

  As the light transmission part material supply device 7, for example, various blade coaters, roll coaters, bar coaters, rod blade coaters, curtain coaters, gravure coaters, and extrusion methods were used so as to obtain an accurate coating amount. Various coating devices such as a coater may be appropriately selected and used. Particularly preferred is a coater using an extrusion method.

  Next, the base material 8 to which the light transmission part material is supplied is pressed against the mold 10 by using the press roll 9. The thickness of the light transmission part obtained in this step is adjusted by the supply amount of the vinyl ester composition supply device 7, the press contact pressure of the press roll 10, and the tension of the substrate 8 on the mold 10.

  Here, as the material of the mold 10 used in this step, a material having rubber elasticity is desirable, and the rubber hardness is more desirably a new JIS K 6253 durometer type A spring hardness of 35 to 65. Further, the material of the mold 10 is desirably a material having releasability without performing a mold release treatment, and more desirably a material having a contact angle with pure water of 100 degrees or more. From these viewpoints, polydimethylsiloxanes having the above physical properties are particularly desirable. In this specification, the contact angle refers to the angle formed by the solid line and the tangent line drawn on the liquid droplet at the intersection of the surface where the pure water is dripped onto the smooth surface of the solid material used for the mold and the solid surface. The angle that contains water. Specifically, it means an angle when measured by the method described in JP-A-5-294057, page 7.

  The mold 10 used for molding is manufactured as follows. First, a master mold having the same shape as the light absorbing portion shown in FIGS. 2 to 4 is manufactured by a technique such as machining, photolithography, or etching. The above-mentioned mold material is pressed against the master mold in an uncured state, and after pressing, is cured by heat, ionizing radiation or the like, and after curing, is peeled off from the master mold to obtain a mold. The form of the mold may be any of a roll, a plate, and a sheet, but the shape of the roll 4 in which the convex portions 5 are formed in the circumferential direction as shown in FIG. 8 is desirable.

  Furthermore, the vinyl ester composition is cured on the mold 10 by using the irradiation device 11 described in the above-described method for curing the light absorbing portion and the light transmitting portion. The molded body formed by curing is peeled off from the mold 10 using a peeling roll 12 to obtain a molded body 13 of a light transmission part.

  Next, steps [5] to [7] will be described with reference to FIG. FIG. 9 is a schematic diagram for explaining a process for manufacturing the light absorbing portion.

  The light absorbing portion material is supplied to the molded body 13 of the light transmitting portion obtained in the above-described process using the light absorbing portion material supply device 14. The light absorbing portion material supply device 14 may be the same device as the vinyl ester supply device 7. Next, the light absorbing portion material is filled into the molded body 13 of the light transmitting portion using the pressure contact roll 15. Thereafter, the surplus portion is scraped off using the blade 16 and cured by the irradiation device 17 described in the method for curing the light transmitting portion. After curing, the light control member 19 is peeled from the substrate by the peeling roll 18. By this step, a film-like light control member as shown in FIG. 10 is obtained.

(5) Method for measuring characteristic and method for evaluating effect The method for measuring the characteristic and the method for evaluating the effect in the present invention are as follows.

(A) Total thickness Based on JIS-C-2151, it measures using a micrometer.

(B) Light control function The produced light control member was attached to a plasma display, and the bright place contrast and screen brightness were evaluated as a light control function.

<Evaluation of photopic contrast>
The produced light control member was mounted on a plasma display so that the light absorption part faced the outside, and the bright place contrast was evaluated. In order to confirm the bright place contrast improvement effect by this invention, sensory evaluation by 10 persons was implemented.

  The plasma display was installed so that the display screen of the plasma display was at an angle of about 40 degrees with respect to the room lamp installed near the ceiling. The illuminance on the display surface by the indoor lighting was about 168 lx (lux) on the horizontal plane and about 200 lx (lux) on the vertical plane.

The observer observed an image with a small contrast difference at a position 1.5 m away from the display. Evaluating points for 8 people, using the front filter (blank) that does not have an external light shielding layer as a reference, using a 4-step scoring system, and removing the maximum value and the minimum value from each of the 10 evaluation results And the evaluation results were digitized. The results are shown in Table 1.
・ 0 point Equivalent to the front filter without external light shielding layer ・ 1 point Somewhat good ・ 2 points Quite good ・ 3 points Very good.

<Evaluation of screen brightness>
In addition, sensory evaluation of screen luminance was performed under the same conditions as for bright place contrast evaluation.

Evaluating points for 8 people, using a front-end filter (blank) without an external light shielding layer as a reference, implemented in a 4-step scoring system, and removing the maximum value and the minimum value one by one from the evaluation results of 10 people And the evaluation results were digitized.
・ 0 point feels very dark ・ 1 point feels very dark ・ 2 points feels a little dark ・ 3 points Equivalent to the front filter without external light shielding layer

<Evaluation of viewing angle>
In addition, the sensory evaluation of the viewing angle was performed under the same conditions as the bright place contrast evaluation.
Evaluating points for 8 people, using the front filter (blank) that does not have an external light shielding layer as a reference, using a 4-step scoring system, and removing the maximum value and the minimum value from each of the 10 evaluation results And the evaluation results were digitized.
-0 point feels a very narrow viewing angle-1 point feels a very narrow viewing angle-2 points feels a little narrow viewing angle-3 points Equivalent to a front filter without an external light shielding layer.

(C) Curl The light control member of the present invention was cut out to a length of 30 cm, and left for 1 hour in an environment of a temperature of 23 ° C. and a relative humidity of 65%. No), Δ (slightly curled but no problem in practical use) × (curled and unusable in practical use) was evaluated in three stages.

(D) Self-supporting property A test piece having a width of 25 mm and a length of 50 mm is used, and the determination is made based on the behavior when bent at 180 degrees when bent in the major axis direction at 25 ° C. and 65% RH. Judgment is based on the following criteria.
○: All three sheets do not break △: All three sheets do not break, but cracks are generated ×: One or more sheets break

(E) Contact angle The contact angle θ is the angle formed by the solid surface and the tangent line drawn on the droplet at the intersection of the surface where the pure water was dropped on the smooth surface of the solid material used for the mold and the solid surface. The angle was determined by the method described in JP-A-5-294057, page 7.

(F) Rubber hardness The rubber hardness of the mold material was measured using a new JIS K 6253 durometer type A spring type (manufactured by Shimadzu Corporation, durometer type A). Values within 1 second were adopted.

(G) Molding stability The light transmissive part was molded, and the following was judged from the number of moldings possible until a defective part unacceptable for the molded product was visually observed.
◎: 15 times or more ○: 5 times or more 15 times or less
Δ: 2 times or more and 5 times or less ×: 2 times or less

(H) Filling stability When the light-absorbing part material is filled in the light-transmitting part molded body molded by the mold, whether the light-absorbing part material is easily repelled is determined according to the following criteria, and this is determined as the light-absorbing part. The filling stability was determined.
○: Does not repel even after filling ×: Repels immediately when filling

  Hereinafter, the present invention will be described in detail based on examples, but the present invention is not necessarily limited thereto.

Example 1
1. Preparation of light absorption part and light transmission part material (Preparation of vinyl ester composition)
In a 1 L flask equipped with a thermometer, stirrer, fractionation condenser, and gas introduction tube, 374.4 g (1.20 mol) of bisphenol A diepoxy compound, 206.4 g (2.4 mol) of methacrylic acid, chromium octylate 1.5 g, 0.15 g of phosphorous acid, and 0.2 g of hydroquinone were added, and the reaction was performed at 120 to 125 ° C. for 2 hours while blowing nitrogen gas. When the acid value reached 11.0, the composition in the flask was poured into a metal vat and cooled to obtain a colorless and transparent vinyl ester composition.

(Other acrylates)
1,6-hexanediol diacrylate (100% solid content) was used as a reaction diluent.

(Photoinitiator: oligohydroxyketone photopolymerization initiator)
2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone polymer (ESACURE KIP150: manufactured by LAMBERTI) was used.

(Black pigment dispersion)
FD Carton ACE black manufactured by Toyo Ink Manufacturing Co., Ltd. was used.

(Surfactant)
MegaFuck F-482 manufactured by Dainippon Ink & Chemicals, Inc. was used.

(Preparation of light transmission material A)
The following materials were mixed and defoamed to obtain a light transmission part forming material.
Vinyl ester composition 70 parts 1,6-hexanediol diacrylate 30 parts Photoinitiator (ESACURE KIP150) 3 parts

(Preparation of light absorbing material A)
The following materials were mixed and defoamed to obtain a light transmission part forming material.
Vinyl ester composition 60 parts 1,6-hexanediol diacrylate 20 parts Black pigment dispersion (FD Carton ACE Black) 20 parts Surfactant (Megafac F-482) 0.1 part Photoinitiator (ESACURE KIP150) 3 Part

2. Molding A master mold having the shape of the following structure A in the shape of the light absorbing portion in FIG. 2 was manufactured by machining.
(Structure A)
Cross section of light absorbing part: rectangle
Light absorber height h: 15 μm
Light absorption part width w: 5 μm
Pitch of light absorbing part p: 15 μm
(P−w) /h=0.667 (atan (p−w) = 33.7 degrees)

  This master mold A was coated with polydimethylsiloxane mixed with a cross-linking agent and defoamed (SH9555RTV manufactured by Toray Dow Corning Co., Ltd.) to a thickness of 2 mm. After coating, in a hot air oven at 50 ° C. for 2 hours. It was cured by heating, allowed to cool to room temperature, and then peeled off from the master mold to obtain a mold. This mold was attached to a roll and used.

3. Manufacturing Method of Light Control Member Using the above-described light transmission part forming material, a PET film (Lumirror T60 manufactured by Toray Industries, Inc.) having a thickness of 50 μm is used as a base material, and the integrated irradiation intensity is 600 mJ by the manufacturing method shown in FIG. Irradiated with UV light of / cm ² , a long sheet-shaped light transmission part molded body having a plurality of grooves formed in parallel in a stripe shape was obtained. At this time, the thickness of the light transmission part was adjusted to 30 μm by adjusting the supply amount of the supply device 7 of the vinyl ester composition, the pressing pressure of the pressing roll 10 and the tension of the base material on the mold.

Further, by using the above-described light absorbing portion forming material, the light absorbing portion forming material is filled in the groove portion of the light transmitting portion molded body, the excess portion is scraped off, and the integrated irradiation intensity is 600 mJ / mm in the manufacturing method shown in FIG. After curing by irradiating with ultraviolet rays of cm ² , the sheet was peeled from the substrate to obtain a sheet-like light control member. The total thickness of the light control member thus obtained was 30 μm.

(Example 2)
A light beam control member was obtained in the same manner as in Example 1 except that the total thickness of the light beam control member was 50 μm.

(Example 3)
A light beam control member was obtained in the same manner as in Example 2 except that the total thickness of the light beam control member was set to 70 μm.

Example 4
A light beam control member was obtained in the same manner as in Example 2 except that a master mold having the shape of the following structure B was used in the shape of the light absorbing portion in FIG.
(Structure B)
Cross-sectional shape of light absorbing part: trapezoid, taper angle 3 degrees Height of light absorbing part h: 15 μm
Light absorption part width w: 5 μm
Light absorption portion pitch p: 13 μm
(P−w / 2) /h=0.7 (atan (p−w) = 35.0 degrees)

(Example 5)
A light beam control member was obtained in the same manner as in Example 2 except that a master mold having the shape of the following structure C was used in the shape of the light absorbing portion in FIG.
(Structure C)
Cross-sectional shape of light absorbing part: height of triangular light absorbing part h: 15 μm
Light absorption part width w: 5 μm
Light absorption portion pitch p: 13 μm
(P−w / 2) /h=0.7 (atan (p−w) = 35.0 degrees)

(Example 6)
A light control member was obtained in the same manner as in Example 2 except that a master mold having the shape of the following structure D was used in the shape of the light absorbing portion in FIG.
(Structure D)
Cross-sectional shape of light absorbing portion; height of rectangular light absorbing portion h: 15 μm
Light absorption part width w: 5 μm
Light absorption portion pitch p: 10 μm
(P−w) /h=0.333 (atan (p−w) = 18.4 degrees)

(Example 7)
A light control member was obtained in the same manner as in Example 2 except that a master mold having the shape of the following structure E was used in the shape of the light absorbing portion in FIG.
(Structure E)
Cross-sectional shape of light absorption part: Height of rectangular light absorption part h: 15 μm
Light absorption part width w: 5 μm
Light absorption portion pitch p: 18 μm
(P−w) /h=0.866 (atan (p−w) = 40.9 degrees)

(Comparative Example 1)
Example 2 except that the following light transmission part material B and light absorption part material B using DPHA (dipentaerythritol hexa (meth) acrylate Nippon Kayaku Co., Ltd. KAYARAD) instead of the vinyl ester composition were used. In the same manner, a light beam control member was obtained.

(Light transmission part material B)
DPHA 70 parts 1,6-hexanediol diacrylate 30 parts Photoinitiator (ESACURE KIP150) 3 parts

(Light Absorbing Material B)
DPHA 60 parts 1,6-hexanediol diacrylate 20 parts Black pigment dispersion (FD Carton ACE Black) 20 parts Surfactant (Megafac F-482) 0.1 part Photoinitiator (ESACURE KIP150) 3 parts

(Comparative Example 2)
A light control member was obtained in the same manner as in Example 2 except that the following light transmission part material B and light absorption part material B using 1,6-hexanediol diacrylate were used instead of the vinyl ester composition. .

(Light transmission part material C)
1,6-hexanediol diacrylate 100 parts Photoinitiator (ESACURE KIP150) 3 parts

(Light Absorbing Material C)
1,6-hexanediol diacrylate 80 parts Black pigment dispersion (FD Carton ACE Black) 20 parts Surfactant (Megafac F-482) 0.1 part Photoinitiator (ESACURE KIP150) 3 parts

(Comparative Example 3)
A light beam control member was obtained in the same manner as in Example 2 except that it was not peeled off from the substrate in the final step.

(Example 8)
A light control member was obtained in the same manner as in Example 2 except that polysiloxane (Sylgard 184 manufactured by Toray Dow Corning) was used as the mold material and the curing condition was 100 ° C. for 45 minutes.

Example 9
A light control member was obtained in the same manner as in Example 2 except that polysiloxane (OE-6336 manufactured by Toray Dow Corning) was used as the mold material and the curing condition was 150 ° C. for 1 hour.

(Comparative Example 4)
A light control member was obtained in the same manner as in Example 2 except that polysiloxane (EG6301 manufactured by Toray Dow Corning) was used as the mold material and the curing condition was 150 ° C. for 1 hour.

(Comparative Example 5)
After molding the mold, a light beam controlling member was obtained in the same manner as in Example 5 except that the mold surface was subjected to release treatment with a fluorine-based surface treatment agent EGC-1720 manufactured by Sumitomo 3M Limited.

(Comparative Example 6)
A light beam control member was obtained in the same manner as in Example 2 except that the mold used was a master mold as a model and manufactured using a nickel electroforming method.

(Comparative Example 7)
After molding the mold, a light beam control member was obtained in the same manner as in Comparative Example 9 except that the mold surface was subjected to release treatment with a fluorine-based surface treatment agent EGC-1720 manufactured by Sumitomo 3M Limited.

The light beam control member prepared as described above was evaluated for light beam control function (contrast, screen luminance) and handling property (self-supporting property, curl). The results are summarized in Table 1.

  From the results of Table 1, Examples 1 to 7 of the present invention using the vinyl ester composition for both the light transmitting part material and the light absorbing material have good contrast and screen brightness and have a light beam control function. Recognize. Moreover, even if it is a single layer structure, it has self-supporting property, curl does not generate | occur | produce, and it turns out that handling property is ensured.

  Further, in the light absorbing members of Examples 1 to 3 in which the cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion is rectangular and the value of the expression (1) is the same, the total thickness in the light transmitting direction is 30 μm or more and 50 μm or less. In Examples 1 and 2 that satisfy the above conditions, the light beam control function and the handling property were equivalent. On the other hand, in Example 3 where the total thickness in the light transmission direction exceeded 50 μm or less, a slight curl occurred. Therefore, it is understood that the total thickness in the light transmission direction is preferably 30 μm or more and 50 μm or less.

  Further, in Example 4 in which the cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion is trapezoidal, and in Example 5 in which it is a triangle, it has a light control function substantially equivalent to that of the optical functional material of Example 2, It can be seen that even a single-layer structure has self-supporting properties, no curling, and handling properties are secured.

  Further, the optical functional material of Example 6 in which the cross-sectional shape perpendicular to the longitudinal direction of the light absorption part is rectangular and the optical functional material of Example 6 smaller than the value of the formula (1) is the same in the other configurations. The screen brightness and viewing angle are inferior. From this, it can be seen that it is necessary to be larger than the value of the expression (1) in order to secure the viewing angle. On the other hand, contrast and self-supporting properties were the same as those of the optical functional material of Example 2, and no curling occurred. From this, it can be seen that the structure of the present invention has a self-supporting property and curling is suppressed and is excellent in handling.

  On the other hand, the optical functional material of Example 7 in which the cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion is rectangular and the optical functional material of Example 7 larger than the value of the expression (1) is the same in the other configuration is the optical functional material of Example 2 The screen brightness and viewing angle were slightly inferior in contrast. From this, it can be seen that in order to ensure the contrast, it is necessary to be smaller than the value of equation (1). On the other hand, contrast and self-supporting properties were the same as those of the optical functional material of Example 2, and no curling occurred. From this, it can be seen that the structure of the present invention has a self-supporting property and curling is suppressed and is excellent in handling.

  On the other hand, the light control material of Comparative Example 1 using DPHA for both the light transmitting part material and the light absorption material is inferior in contrast and screen brightness compared to the light control material of Example 2 having the same structure and size except for the material. It can be seen that the light beam control function is inferior. Moreover, since the light control material of the comparative example 1 does not have a self-supporting property, it turns out that it cannot utilize as a light control material of 1 layer structure.

  In addition, the light control material of Comparative Example 2 using 1,6-hexanediol diacrylate for both the light transmitting portion material and the light absorption material is compared to the light control material of Example 2 having the same structure and size except for the material. It can be seen that the contrast and the screen brightness are inferior and the light beam control function is inferior. Moreover, since the light control material of the comparative example 1 does not have a self-supporting property, it turns out that it cannot utilize as a light control material of 1 layer structure.

  Further, the light control material of Comparative Example 4 using the light control material of Example 2 without peeling from the substrate is inferior in contrast and screen brightness and inferior in the light control function as compared with the light control material of Example 2. I understand. Further, the light control material of Comparative Example 4 was curled.

The light control member prepared as described above was evaluated for its production stability (molding stability, filling stability). The results are summarized in Table 2.

  From the results of Table 2, using polysiloxane, the contact angle is 100 ° or more, and the new JIS K 6253 durometer type A spring hardness (rubber hardness) is within the scope of the present invention. In the case of using the mold, it can be understood that the molding stability of the light transmitting portion is excellent and the filling of the light absorbing material can be performed stably without performing the mold release treatment as in the first embodiment.

  On the other hand, when the mold of Comparative Example 4 in which the new JIS K 6253 durometer type A spring type hardness (rubber hardness) is harder than the range of the present invention is used, the molding of the light transmission part is performed as compared with Examples 1, 8, and 9. Stability is inferior.

  In addition, it can be seen that when Comparative Example 5 in which a mold release treatment is performed on the mold of Example 8 is used, the filling of the light absorbing material is not sufficient as compared with Example 8.

  In the case of using the mold of Comparative Example 6 manufactured using the nickel electrocasting method using the master mold as a model, the light transmitting portion could not be stably formed.

  In addition, when the mold of Comparative Example 7 subjected to the release treatment was used as the mold of Comparative Example 6, the molding stability of the light transmitting portion was improved as compared with the case of Comparative Example 6, but the light absorbing material was not filled. I did not.

FIG. 1 is a schematic view of the light beam control member of the present invention observed from the light incident direction. FIG. 2 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of an embodiment of the light beam control member of the present invention. FIG. 3 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of another embodiment of the light beam control member of the present invention. FIG. 4 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of another embodiment of the light beam control member of the present invention. FIG. 5 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of another embodiment of the light beam control member of the present invention. FIG. 6 is a schematic cross-sectional view (cross-sectional view in the AA direction in FIG. 1) of another embodiment of the light beam control member of the present invention. FIG. 7 is a schematic diagram for explaining a process of manufacturing the light transmission part. FIG. 8 is a schematic view showing an example of a mold used for manufacturing the light beam control member of the present invention. FIG. 9 is a schematic diagram for explaining a process for manufacturing the light absorbing portion. FIG. 10 shows a film-shaped light control member obtained by the method for manufacturing a light control member of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light control member 2 Light absorption part 3 Light transmission part 4 Mold 5 Convex part on mold 6 Base material 7 Light transmission part material supply device 8 Base material 9 supplied with vinyl ester Pressing roll 10 Mold 11 Irradiation device 12 Peeling Roll 13 Light molded part molded body 14 Light absorbing part material supply device
15 pressure contact roll 16 blade 17 irradiation device 18 peeling roll 19 light beam control member

Claims (9)

A light beam control member having a light transmission part and a plurality of light absorption parts arranged on the one surface of the light transmission part in parallel with each other at a predetermined interval,
The light control member contains a vinyl ester composition,
The light transmission member is a light beam control member having a single layer structure.   The light beam control member according to claim 1, wherein the light beam control member has a total thickness in the light transmission direction of 10 μm or more and 50 μm or less. The light absorbing portion has a rectangular cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion,
When the height of the rectangle in the light transmission direction of the light control member is h, the width of the rectangle in the surface direction of the light transmission part is w, and the pitch of the plurality of light absorption parts is p, the h, The light control member according to claim 1, wherein w and p satisfy the following formula.
α ≦ atan (p−w) / h ≦ θ (1)
α = 20 °, θ = 40 ° The light absorbing portion has a shape other than a rectangular cross-sectional shape perpendicular to the longitudinal direction of the light absorbing portion,
When the height of the shape in the light transmission direction of the light control member is h, the width of the shape in the surface direction of the light transmission part is w, and the pitch of the light absorption parts is p, the h, The light control member according to claim 1, wherein w and p satisfy the following formula.
α ≦ atan (p−w / 2) / h ≦ θ (2)
α = 20 °, θ = 40 °   The light control member according to claim 1, wherein the vinyl ester composition includes a liquid oligomer and a monomer mainly composed of the vinyl ester composition, and is curable by active energy rays.   The light control member according to claim 1, wherein the light absorbing portion contains a black pigment dispersion. Step 1 for supplying the vinyl ester composition onto the substrate, Step 2 for pressing the substrate supplied with the vinyl ester composition against the mold, and filling between the pressed substrate and the mold Step 3 for curing the vinyl ester composition, Step 4 for peeling the molded body formed by the curing from the mold, and filling the concave portion formed on the molded body with a mixture of a black material and a vinyl ester composition A process for producing a light control member, comprising: a step 5 for curing; a step 6 for curing the filled mixture; and a step 7 for peeling the molded body from a substrate.
The mold material which comprises the mold used at the said process 2 is a manufacturing method of the light control member whose new JIS K 6253 durometer type A spring type hardness is 35-65.   The manufacturing method of the light control member of Claim 7 whose mold formation material which comprises the said mold is a material whose contact angle with respect to a pure water is 100 degree | times or more. The manufacturing method of the light control member of Claim 7 or 8 whose mold formation material which comprises the said mold is polydimethylsiloxane.

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