JP5366085B2 - Projection screen - Google Patents

Description

  The present invention relates to a transmissive projection screen used for a rear projection display.

  The rear projection display is a display method that allows an image projected on the rear side of the screen by the projector to be viewed from the front side of the screen.

  Conventionally, a combination of a Fresnel lens and a lenticular lens is known as a transmission type projection screen used for a rear projection display. However, such conventional projection screens generally have problems such as a dark screen and a moire pattern due to pitch easily occurring on the screen.

  In the above conventional projection screen, a black stripe is arranged on the focal plane of the lenticular lens, and a part of the outside light is absorbed by the black stripe without attenuating the condensed projector light, thereby reducing the contrast due to the outside light. The technique of suppressing is taken (nonpatent literature 1). However, in practice, a part of the outside light is not absorbed by the black stripes and enters the optical system, so that the reduction in contrast is still a problem.

  In contrast, a new projection screen that does not use a conventional Fresnel lens or lenticular lens has been proposed that uses a light control film. Specifically, it is a projection screen that uses a light control film having an angle dependency on the haze (Patent Documents 1 to 7). In the projection screen, a plurality of light control films are angle-dependent on the haze. The viewing angle can be widened by stacking so that the directions of the light beams cross at right angles (Patent Documents 8 and 9) or by stacking a plurality of light control films having different haze values depending on the angle (Patent Document 10). ~ 13).

  According to these inventions, it is possible to obtain a projection screen in which diffused and transmitted light exhibits high uniformity over a wide angular range, and by laminating a plurality of the light control films, the brightness and uniformity of the screen are improved. An excellent high viewing angle projection screen can be constructed.

Japanese Unexamined Patent Publication No. 63-309902 Japanese Patent Laid-Open No. 64-40905 JP-A 64-77001 Japanese Unexamined Patent Publication No. 2-67501 JP-A-2-54201 Japanese Patent Laid-Open No. 3-107901 Japanese Patent Laid-Open No. 3-107902 JP-A-3-127039 Japanese Patent Laid-Open No. 3-127042 Japanese Patent Laid-Open No. 3-200909 JP-A-4-77728 JP 2005-316354 A JP 2005-31631 A

K.Ebina, “Optical System Architecures for Rear Projection Screen” SID02DIGEST, p1342-1345 (2002)

  However, even in the projection screen using the light control film as described above, outside light such as room lighting or sunlight enters from the front side of the screen, and a part of the transmitted light causes back scattering in the light control film. There is a problem. Backscattering means scattering at an angle exceeding 90 ° with respect to the incident direction of light. This backscattered light causes a decrease in contrast, and hinders visual recognition particularly during black display.

  In order to suppress the backscattering of the light incident on the screen, it is conceivable to apply a polarizing plate. However, a general polarizing plate using a stretched PVA (polyvinyl alcohol) film has a temperature and humidity due to its configuration. Therefore, when a polarizing plate is provided only on one side of a panel using acrylic or glass as a support, there arises a problem that warping occurs with time.

  The present invention has been made in view of such a situation, and an object thereof is to provide a projection screen that can suppress backscattering of light incident from the front of the screen without using a polarizing plate. .

  To achieve the above object, the present invention provides a transmissive projection screen for use in a rear projection display, a light diffusion control layer for controlling light diffusion, a film having no polarization function, the light A projection screen comprising a diffusion control layer and a colored pressure-sensitive adhesive layer interposed between the film having no polarizing function is provided (Invention 1).

  According to the above invention (Invention 1), the colored adhesive layer can suppress the backscattering of the light incident from the front of the screen, and at the same time, the black luminance of the projector light can be lowered, thereby improving the contrast. be able to. Furthermore, since a polarizing plate is not used, there is no problem of warping, and it can be manufactured at low cost, and the configuration can be simplified.

  In the above invention (Invention 1), the light diffusion control layer is a light control film obtained by irradiating and curing a film of a composition containing at least two kinds of photopolymerizable compounds having a difference in refractive index. (Invention 2).

  In the said invention (invention 1), it is preferable that the said light-diffusion control layer is a laminated body which laminated | stacked the said light control film | membrane in the direction in which the light-scattering angle area | regions mutually correspond substantially (invention 3).

  In the above inventions (Inventions 1 to 3), the color change of the transmitted light by the colored pressure-sensitive adhesive layer is within ± 0.0030 in both hue changes Δx and Δy defined by the CIE1931 chromaticity diagram, and The luminous transmittance Y of the colored pressure-sensitive adhesive layer is preferably 15 to 90% (Invention 4).

  In the said invention (invention 1-4), it is preferable that the said colored adhesive layer is colored with the metal complex dye (invention 5).

  In the said invention (invention 5), it is preferable that the said metal complex dye is a chromium complex dye (invention 6).

  In the said invention (invention 1-6), it is preferable that the film which does not have the said polarization function is a hard coat film (invention 7).

  In the said invention (invention 1-7), it is preferable that the film which does not have the said polarization function is a film which has a reflection control layer and / or a glare-proof layer (invention 8).

  In the said invention (invention 1-8), it is preferable to provide the antireflection layer in the outermost layer by the side of a projector (invention 9).

  In the said invention (invention 1-9), it was preferable to provide the transparent substrate (invention 10).

  In the said invention (invention 1-8), a transparent substrate, the said light-diffusion control layer, the said colored adhesive layer, and the film which does not have the said polarization function may be laminated | stacked in an order from the projector side. Preferred (Invention 11).

  In the above invention (Invention 11), it is preferable that an antireflection layer is provided on the projector side of the transparent substrate (Invention 12).

  In the projection screen according to the present invention, the colored adhesive layer can suppress the backscattering of the light incident from the front of the screen, and at the same time, the black luminance of the projector light can be reduced, thereby improving the contrast. Can do. Furthermore, since a polarizing plate is not used, there is no problem of warping, and it can be manufactured at low cost, and the configuration can be simplified.

It is a figure which shows the layer structure of the projection screen which concerns on one Embodiment of this invention. It is a figure which shows one manufacture example of the light-diffusion control layer in the projection screen which concerns on the same embodiment. 6 is a diagram illustrating a backscattering measurement method in Test Example 1. FIG.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram showing a layer configuration of a projection screen according to an embodiment of the present invention (a diagram showing the entire projector including the projector as viewed from above).

  As shown in FIG. 1, a projection screen 1 according to this embodiment includes a light diffusion control layer 2 and a colored adhesive layer 3 on one side (front side; opposite to the projector P) of the light diffusion control layer 2. , A transparent substrate 5 laminated on the other side (back side; projector P side) of the light diffusion control layer 2, and an antireflection film 6 laminated on the transparent substrate 5. Consists of.

(Light diffusion control layer)
The light diffusion control layer 2 is a layer that controls the diffusion of light incident from the projector P. In this embodiment, the light diffusion control layer 2 is formed by using a light control film instead of the conventional Fresnel lens or lenticular lens, and preferably the light diffusion layer. It is formed using a light control film laminate in which a control film is laminated. Here, the light diffusion control layer refers to a layer having a function of selectively scattering only incident light from a specific angle range and transmitting incident light at other angles, and the light control film is cloudy. It is a film having an angle dependence on the valence, and refers to a film having a light scattering angle region width of 30 ° or more.

The haze here is a value obtained by measuring the total light transmittance and diffuse transmittance of the light control film using an integrating sphere light transmittance measuring device, and obtaining the following equation.
Haze value (%) = diffuse transmittance (%) / total light transmittance (%) × 100
(Diffuse transmittance = total light transmittance-parallel light transmittance)

  Further, the angle dependency of the haze value in the light control film is measured as follows. That is, the angle θ of the incident light on the test piece of the light control film is changed between 0 to 180 °, the above-described haze value is measured for each angle, and the angle range showing a haze value of 60% or more Is the light scattering angle region. Here, the angle θ is a value in which the direction parallel to the surface of the test piece is 0 ° and the normal direction of the test piece is 90 °, and the rotation of the test piece has a maximum angle dependency of the haze value. In the direction.

  The light control film is suitably formed by forming a composition containing at least two kinds of photopolymerizable compounds having a difference in refractive index into a film shape and irradiating the composition with light from a specific direction. Can be manufactured.

The photopolymerizable compound used for the production of the light control film includes an acryloyl group [CH ₂ ═CHCO—], a methacryloyl group [CH ₂ ═C (CH ₃ ) CO—], a vinyl group [CH ₂ ═ = It is a compound having at least one polymerizable group such as CH—] or allyl group [CH ₂ ═CHCH ₂ —], and various monomers or oligomers can be used.

  Examples of the monomer include tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyloxyethyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and ω-hydroxyhexanoyloxyethyl. Acrylate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate, 2,4,6-tribromophenyl acrylate, 2,4,6-tribromophenoxyethyl acrylate, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2 , 2,3,3-tetrafluoropropyl acrylate, phenyl carbitol acrylate, nonylphenoxye And Le acrylates, methacrylates corresponding to these monofunctional acrylates, furthermore, N- vinylpyrrolidone, triallyl isocyanurate, diethylene glycol diallyl carbonate, such as di-arylidene pentaerythritol.

  Examples of the oligomer include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, polybutadiene acrylate, epoxy acrylate, and urethane acrylate. And methacrylates corresponding to the functional acrylate.

  These photopolymerizable compounds are used as a composition comprising at least two kinds of mixtures. At this time, one having a difference in refractive index is selected. A region in which light is scattered, that is, a light scattering angle region, is formed by irradiating light from a predetermined direction and curing the composition in which at least two kinds of photopolymerizable compounds having different refractive indexes are mixed. This composition expresses the angle dependency of the haze value due to the mutual solubility of each of a plurality of composing compounds and the respective refractive index differences, and the refractive index difference is large due to a combination with poor compatibility. When the reaction rate is different, the degree of light scattering, that is, the haze value increases. This refractive index difference is preferably 0.01 or more.

  In order to improve curability, this composition is usually mixed with a photopolymerization initiator and subjected to photopolymerization. Examples of the photopolymerization initiator include benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin methyl ether, benzoin ethyl ether, diethoxyacetophenone, benzyldimethyl ketal, and 2-hydroxy-2-methyl. Examples include propiophenone and 1-hydroxycyclohexyl phenyl ketone.

  Such a photocurable composition containing at least two kinds of compounds having a difference in refractive index is applied on a substrate or enclosed in a cell to form a film, and irradiated with light from a rod-shaped light source By gradually curing, a light control film is obtained that scatters incident light in a selective angle region and transmits straight in other angle regions.

  The light used for curing may have any wavelength as long as it cures the composition, and for example, visible light, ultraviolet light, and the like are often used. Ultraviolet rays are emitted from mercury lamps and metal halide lamps. Here, when a rod-shaped lamp is used as the light source, the generated photocured film exhibits anisotropy by adjusting the irradiation conditions (for example, providing a slit or the like at a predetermined position of the irradiation path) When the incident angle of light from the light source is changed, light at a specific angle is scattered. The anisotropy here refers to a film-specific diffusion characteristic when the incident angle of light is changed in the MD (Machine Direction) direction (manufacturing line direction), and the CD (Cross Direction) direction (width). Direction), when the incident angle of light is changed, characteristic diffusion characteristics do not appear (diffuse in all angle ranges). This is because the rod-shaped lamp is arranged perpendicularly to the MD direction and irradiated.

  The degree of scattering and the angle of selectively scattered incident light can be adjusted depending on the composition used and the irradiation conditions, and in particular, by changing the incident angle of the irradiated light on the film-like composition sample surface during curing, When the light incident on the cured sheet exits from the sheet, the angle range with respect to the sheet film surface through which the light is scattered or straightly transmitted can be controlled.

  At the time of photocuring, a light scattering angle region is developed around the light irradiation direction. For example, when light is irradiated almost perpendicularly to the film surface formed from the photocurable composition, a light scattering angle region appears around the vertical direction, that is, the normal direction of the obtained light control film. If light is irradiated from an oblique direction inclined by a predetermined angle with respect to the normal direction, a light scattering angle region is developed around the inclined direction.

  When a plurality of light control films each having a light scattering angle range of 30 ° or more showing a haze value of 60% or more are laminated to form a light control film laminate, the light scattering angle ranges are substantially equal to each other as the light control film. It is preferable to use a plurality of the same.

Here, the light scattering angle regions of the light control film are substantially the same as each other. The light scattering angle region of any one of the light control films as a reference is θ ₁ to θ ₂ (where θ ₁ <θ ₂ ), and when the light scattering angle region of another light control film laminated on this is expressed as θ ₁ ′ to θ ₂ ′ (where θ ₁ ′ <θ ₂ ′), θ ₁ and θ ₁ ′ (| θ ₁ −θ ₁ ′ |) and θ ₂ and θ ₂ ′ (| θ ₂ −θ ₂ ′ |) are the reference light scattering angles of the light control film, respectively. It means that up to about 5% of the width of the region (θ ₂ −θ ₁ ) is allowed.

  When laminating a plurality of light control films whose centers of light scattering angle regions substantially coincide with the normal direction of the light control film, laminate the light scattering angle regions so that the extending directions of the light scattering angle regions are substantially parallel to each other. It is preferable. Further, when a plurality of light control films in which the light scattering angle region is biased with respect to the normal direction of the light control film are stacked, the directions in which the light scattering angle regions extend are substantially parallel to each other, and It is preferable to laminate so that the light scattering angle regions are in the same direction with respect to the normal direction. In this specification, “almost” in terms of “substantially coincide”, “substantially parallel”, etc. means that up to about ± 10 ° is allowed around the arrangement (coincidence or parallel) described therein. To do.

An example of stacking a plurality of light control films will be described with reference to FIG.
First, light control films 8a and 8b showing a haze value of 60% or more in the range of angle γ are laminated in a direction in which the width of the light scattering angle region is biased to the right with respect to the normal direction of the light control film. Thus, the first light control film laminate 8 having a haze value of 60% or more in the range of the angle γ ′ in the direction biased to the right with respect to the normal direction is obtained. The angle γ corresponds to the width of the light scattering angle region of the light control films 8a and 8b, and extends in a direction perpendicular to the paper surface. If these two light control films 8a and 8b are laminated in this direction, the angle is the same as the angle γ or slightly wider than the angle γ in the direction biased to the right with respect to the normal direction of the light control film. The first light control film laminate 8 showing a haze value of 60% or more in the range of γ ′ is obtained. That is, this angle γ ′ corresponds to the width of the light scattering angle region of the first light control film laminate 8 and extends in a direction perpendicular to the paper surface.

  Secondly, in the same manner as described above, the light control film 9a exhibits a haze value of 60% or more in the range of the angle γ in the direction in which the width of the light scattering angle region is biased to the left with respect to the normal direction of the light control film. And 9b are laminated to obtain a second light control film laminate 9 having a haze of 60% or more in the range of the angle γ ′ in the direction biased to the left with respect to the normal direction of the light control film. The second light control film laminate 9 corresponds to a state in which the direction of the first light control film laminate 8 is reversed (a state in which left and right are reversed in this drawing).

  Thirdly, light control films 7a and 7b exhibiting a haze value of 60% or more in the range of the angle β with the width of the light scattering angle region centered on the normal line direction of the light control film are laminated to form a light control film method. A third light control film laminate 7 having a haze of 60% or more in the range of the angle β ′ around the line direction is obtained. The angle β corresponds to the width of the light scattering angle region of the light control films 7a and 7b, and extends in a direction perpendicular to the paper surface. Then, if these two light control films 7a and 7b are laminated in this direction, the angle 60 ′ is set within the range of the angle β ′ that is the same as the angle β or slightly wider than the angle β with the normal line direction of the light control film as the center. A third light control film laminate 7 showing a haze value of at least% is obtained. That is, this angle β ′ corresponds to the width of the light scattering angle region of the third light control film laminate 7 and extends in a direction perpendicular to the paper surface.

  Lamination of the light control film may be performed, for example, by cutting the light control film into an appropriate size and pasting them with a single sheet, or by laminating two or more individually produced light control films at the same time. You may carry out by supplying to an apparatus and bonding continuously. In that case, in order to make bonding of light control films | membranes stronger, you may bond using an adhesive, an adhesive agent, etc.

  Alternatively, the light control film can also be laminated by using the light control film itself as a base material and applying and curing the photocurable composition thereon to form another light control film. According to such a method, the above-described laminating operation or apparatus is unnecessary, and the light control film laminate can be produced with good productivity and advantageous in terms of cost. When the light control film itself is used as a base material, first, as described above, as described above, the light curable composition film is irradiated with light to be cured, whereby a predetermined light control serving as the base material is performed. A film is obtained, and then, as a second step, a photocurable composition film having substantially the same composition as that used in the first step is formed on the light control film obtained in the first step. It is formed with substantially the same thickness as in one step, and the composition film has substantially the same conditions as the first step in the irradiation direction, the distance from the light source, the amount of irradiation light, the wavelength of irradiation light, etc. As described above, it is possible to form a further light control film by irradiating and curing light, and further repeat this second step as necessary.

  Since the light control film laminate thus obtained exhibits high uniformity over a wide angle range of diffuse transmitted light, by applying this to the projection screen, a projection screen with excellent screen brightness and uniformity can be obtained. Can do. The light diffusion control layer 2 can be formed from a single layer. However, in order to widen the viewing angle, the light diffusion control layer 2 is formed using a light control film stack obtained by stacking a plurality of light control films. It is desirable to do. In the light diffusion control layer 2 obtained by laminating the light control film laminate, the light control films are usually laminated in 2 to 20 sheets, preferably 4 to 16 sheets, particularly preferably 6 to 12 sheets. The

  When a plurality of light control film stacks are stacked, the light scattering performance and the stacking direction exhibited by each light control film stack are appropriately selected. However, as an advantageous aspect for a projection screen, the light scattering angle region is light. Two light control film laminates that are biased with respect to the normal direction of the control film laminate so that the light scattering angle ranges are opposite to each other about the normal direction of the light control film laminate It is preferable to stack the layers so that the width of the light scattering angle region in the stacked state is wider than that of a single sheet. By doing so, it is possible to widen a good visual recognition area in the left-right or vertical direction, that is, a viewing angle.

  In addition, the light control film layered body in which the center line of the light scattering angle region substantially coincides with the normal direction is arranged so that the center line of the light scattering angle region is substantially parallel to the two light control film layered bodies. It is also effective to stack so as to be. By doing so, a brighter image can be obtained in front of the screen.

  Therefore, the light scattering angle region of the first light control film stack 8 and the second light control film stack 9 in the direction in which the light scattering angle region is deviated with respect to the normal direction is controlled by the light scattering angle region. The film stacks are stacked so that they are opposite to each other about the normal direction of the film stack. This laminate exhibits a haze value of 60% or more in a range of an angle δ wider than the width γ ′ of each light scattering angle region.

  At this time, when the width γ ′ of the light scattering angle region of the first light control film stack 8 and the width γ ′ of the light scattering angle region of the second light control film stack 9 are just in contact with each other, It is advantageous that the light scattering angle region of the light control film stacks 8 and 9 can be utilized to the maximum and the maximum viewing angle expansion effect can be obtained.

  Further, the width γ ′ of the light scattering angle region of the first light control film laminate 8 and the width γ ′ of the light scattering angle region of the second light control film laminate 9 preferably overlap each other by 5 ° or more. It is advantageous to have a brighter image in front of the screen. On the other hand, if the angle at which the two light scattering angle regions overlap is too large, the effect of widening the viewing angle is sacrificed, so the extent of the light scattering angle region in the light control film stacks 8 and 9 before being stacked is increased. However, it is preferable that a total of 40 ° or more, more preferably 50 ° or more of the regions where the light scattering angle regions do not overlap when two sheets are stacked.

  Further, the width γ ′ of the light scattering angle region of the first light control film stack 8 and the width γ ′ of the light scattering angle region of the second light control film stack 9 are symmetric with respect to the normal direction. This is advantageous because the visual characteristics are the same on the right and left sides or on the upper and lower sides of the screen.

  Finally, the third light control film laminate 7 is further added to the center line of each of the widths γ ′ and β ′ of the light scattering angle region with respect to the laminate of the two light control film laminates 8 and 9. Are laminated in parallel to each other (normal direction of each light control film laminate). Thereby, a brighter image can be obtained in front of the screen.

  In FIG. 2, the case where the third light control film stack 7 is stacked on the first light control film stack 8 and the second light control film stack 9 has been described as an example. The third light control film stack 7 may be stacked under the first light control film stack 8 and the second light control film stack 9, for example. A third light control film stack 7 may be inserted between one light control film stack 8 and the second light control film stack 9. Moreover, although FIG. 2 demonstrated on the assumption that the two light control film laminated bodies 8 and 9 were the same kind, you may use a thing of a different kind.

  Furthermore, in FIG. 2, the case where three light control film stacks are stacked has been described as an example, but four or more may be stacked. For example, when four or more light control film stacks are stacked in a state where three light control film stacks 7, 8, and 9 are stacked as shown in FIG. The four or more light control film laminates may be laminated so that the light scattering angle regions are substantially the same. For example, you may laminate | stack so that the light-scattering angle area of the light control film laminated body 7,8,9 may become substantially the same. Or you may further laminate | stack two sheets from which the light-scattering angle area was unevenly distributed from the normal line direction of the laminated body opposite to each other like the laminated | stacked light control film laminated bodies 8 and 9. FIG. In this case, the stacking order can be arbitrarily selected. Further, the fourth or later light control film laminate also has a light scattering angle region width of 30 ° showing a haze value of 60% or more, like the three light control film laminates 7, 8, and 9 described above. In particular, it is more preferably 40 ° or more, and further preferably 45 ° or more. In addition, although the width | variety of the light-scattering angle area of a light control film laminated body is so preferable that it is wide, it is usually 170 degrees or less.

  The light control film laminate may be used as a flat plate in which a plurality of light control films are laminated, or the outermost layer may have a lenticular lens shape. As a method for forming a lens curved surface, there is a method for forming a light control film having a lens curved surface in addition to a method for laminating a light control film laminate on a film having a lens curved surface. When the latter method is employed, for example, a mold having a lens curved surface is used, and a photocurable resin composition is applied thereto and further irradiated with light to give the cured product a lens curved surface.

  In addition, the light diffusion control layer 2 in the present embodiment is desired to be as thin as possible from the viewpoint of reducing the thickness of the screen. However, a certain degree of film thickness is required in order to exhibit sufficient light scattering characteristics. That is, the film thickness of the light diffusion control layer 2 is preferably 50 to 3000 μm, and more preferably 150 to 2000 μm. By setting the film thickness within this range, the light diffusion angle and the distribution characteristics of the light diffusion light with respect to the wavelength can be made uniform.

  In order to make the light diffusion control layer 2 have the above film thickness, the thickness of the light control film itself is usually 5 to 300 μm, preferably 15 to 250 μm, and particularly preferably 50 to 200 μm. In addition, about uniforming the distribution characteristic of light diffused light, it may be performed by thickness control by the number of laminated light control films as described above, or by film thickness control per layer.

(Colored adhesive layer)
In the projection screen 1 according to the present embodiment, the colored adhesive layer 3 interposed between the light diffusion control layer 2 and the coating film 4 allows the light diffusion control layer 2 of light (external light) incident from the front of the screen. Can be suppressed, and at the same time, the black luminance of the projector light can be lowered, so that the contrast can be improved. In a projection screen using a Fresnel lens and a lenticular lens, a black matrix is generally provided on the lenticular lens, but the colored pressure-sensitive adhesive layer 3 can be considered to have an alternative effect.

  Regarding suppression of backscattering of external light, for example, when a colored pressure-sensitive adhesive layer 3 having a transmittance of 40% is provided and the transmitted light is considered to be 100% backscattered at the interface of the light diffusion control layer 2, the light is colored twice. Since the adhesive layer 3 is passed, backscattering can be suppressed to 100% × 0.4 × 0.4 = 16%.

  In the invention described in Japanese Patent Application Laid-Open No. 2005-274955, preventing the entry of external light into the optical system by reducing the transmittance using a dye causes a reduction in the utilization efficiency of the projector light. Deny, use a polarizer. However, it is very difficult to match the polarization of the projector light and the transmission axis of the polarizer to be arranged, and unless they match, the projector light will be absorbed according to the transmittance of the polarizer. In this respect, the same can be said even if the transmittance is lowered by using a dye. Rather than using a polarizer, the provision of the colored pressure-sensitive adhesive layer 3 as in the present embodiment not only suppresses backscattering of external light, but also improves the contrast, thereby increasing visibility. In addition, the polarizer has a problem of warpage and is expensive, and the configuration as a screen is complicated. However, if the colored pressure-sensitive adhesive layer 3 is used, there is no problem of warpage and it is inexpensive. It can be manufactured and the configuration can be simplified.

  The colored pressure-sensitive adhesive layer 3 is composed of a colored pressure-sensitive adhesive (colored pressure-sensitive adhesive), and the colored pressure-sensitive adhesive contains a pressure-sensitive adhesive resin as a main component and a colorant.

  Examples of the adhesive resin include acrylic, rubber, and silicone adhesive resins, among which acrylic copolymers are preferable. Examples of the acrylic copolymer include (meth) acrylic acid ester copolymers. In this specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

  As the (meth) acrylic acid ester copolymer, those having a crosslinking point that can be crosslinked by various crosslinking methods are preferably used. There is no particular limitation on the (meth) acrylic acid ester-based copolymer having such a crosslinking point, and any (meth) acrylic acid ester-based copolymer conventionally used as a resin component of an adhesive can be arbitrarily selected. Can be selected and used.

  As a (meth) acrylic acid ester-based copolymer having such a crosslinking point, a (meth) acrylic acid ester having an alkyl group of 1 to 20 carbon atoms and a crosslinkable functional group in the molecule. Preferable examples include copolymers of monomers and other monomers used as desired.

  Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms of the alkyl group in the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, ( Examples include dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  The monomer having a crosslinkable functional group in the molecule preferably contains at least one selected from the group consisting of a hydroxyl group, a carboxyl group, and an amino group as a functional group. As a specific example, (meth) acrylic acid 2-hydroxyethyl, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, (meth) acrylic acid (Meth) acrylic acid hydroxyalkyl esters such as 4-hydroxybutyl; (meth) acrylic acid monomethylaminoethyl, (meth) acrylic acid monoethylaminoethyl, (meth) acrylic acid monomethylaminopropyl, (meth) acrylic acid monoethyl Monoalkylamino (meth) acrylates such as aminopropyl Steal; (Meth) acrylic acid dimethylaminoethyl, (meth) acrylic acid diethylaminoethyl and other (meth) acrylic acid dialkylamino esters; acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid and other ethylenic acids And unsaturated carboxylic acid. These monomers may be used independently and may be used in combination of 2 or more type.

  Examples of other monomers include acrylamides such as (meth) acrylamide, N-methyl (meth) acrylamide, and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; ethylene, propylene Olefins such as styrene, isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene monomers such as styrene and α-methylstyrene; diene monomers such as butadiene, isoprene and chloroprene; acrylonitrile and methacrylo Examples thereof include nitrile monomers such as nitrile. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester copolymer is not particularly limited as to its copolymerization form, and may be any of a random copolymer, a block copolymer, or a graft copolymer. As the molecular weight, those having a weight average molecular weight of 500,000 or more are usually used. When the weight average molecular weight is 500,000 or more, adhesion and adhesion durability are sufficient, and neither lifting nor peeling occurs. In view of adhesion and adhesion durability, the weight average molecular weight is preferably 600,000 to 2,200,000, particularly preferably 700,000 to 2,000,000. In addition, the weight average molecular weight in this specification is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  The colorant contained in the colored pressure-sensitive adhesive layer 3 is preferably such that light transmitted through the colored pressure-sensitive adhesive layer 3 does not cause a change in color tone. The degree of allowable color change is such that it is difficult for the human eye to recognize the change in hue. Specifically, the color change of transmitted light by the colored adhesive layer 3 is determined by the International Lighting Commission. The hue changes Δx and Δy defined by the standard CIE1931 chromaticity diagram are both preferably within ± 0.0030, and more preferably within ± 0.0020. If the hue change is within such a range, it is difficult for the human eye to recognize the hue change.

  On the other hand, the luminous transmittance Y of the colored pressure-sensitive adhesive layer 3 is usually preferably 90% or less, more preferably 75% or less, and particularly preferably 65 in order to effectively suppress the backscattering of external light. % Or less. If the luminous transmittance Y is low, it is necessary to increase the intensity of the projector light. If the luminous transmittance Y of the colored adhesive layer 3 is too low, a clear image can be obtained even if the intensity of the projector light is increased. There is a risk that it will not be obtained. From such a viewpoint, the luminous transmittance Y of the colored pressure-sensitive adhesive layer 3 is preferably 15% or more, more preferably 20% or more, and particularly preferably 45% or more. The luminous transmittance Y is a value calculated from the CIE 1931 chromaticity diagram.

  In order to suppress color tone change, the colorants can be used in appropriate combinations, and it is preferable to create a neutral gray color by the combination. However, if the color of the other layers 2, 4, 5, 6, and 7 of the transparent body pasting screen 1 is lost, the color tone is corrected by appropriately selecting the colorant of the colored adhesive layer 3. You can also.

  As the colorant, known ones such as inorganic pigments, organic pigments and organic dyes can be used.

  Examples of inorganic pigments include carbon black, cobalt dyes, iron dyes, chromium dyes, titanium dyes, vanadium dyes, zirconium dyes, molybdenum dyes, ruthenium dyes, platinum dyes, ITO (indium) Tin oxide) dyes, ATO (antimony tin oxide) dyes, and the like.

  Examples of organic pigments and organic dyes include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, azurenium dyes, polymethine dyes, naphthoquinone dyes, pyrylium dyes, and phthalocyanine dyes. , Naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes, quinophthalone dyes, pyrrole Dyes, thioindigo dyes, metal complex dyes (metal complex dyes), dithiol metal complex dyes, indolephenol dyes, triallylmethane dyes, anthraquinone dyes, dioxazine dyes, naphthol dyes, azomethine dyes, Ben Imidazolone dyes, pyranthrone pigments and threne color like. These pigments or dyes can be appropriately mixed and used in order to adjust the target hue.

  Some colorants may react with the functional groups of the adhesive resin, crosslinking agents, etc. to cause gelation of the adhesive or increase in the haze value of the adhesive layer. . Among the above colorants, metal complex dyes, particularly chromium complex dyes are preferred because they are less susceptible to the influence of the functional group of the adhesive resin and are less likely to deteriorate, so that a highly durable colored adhesive layer 3 can be obtained. Among the above colorants, carbon black has the effect of imparting very high weather resistance when added alone. However, from the viewpoint of dispersibility with respect to the adhesive resin, a dye is preferable to a pigment.

  The lower limit of the content of the colorant in the colored pressure-sensitive adhesive is not particularly limited as long as the desired effect is obtained, but is usually about 0.01% by mass. On the other hand, the upper limit of the content of the colorant in the colored adhesive is preferably 15% by mass or less, thereby ensuring the durability of the colored adhesive layer 3. From such a viewpoint, the content of the colorant in the colored pressure-sensitive adhesive is preferably 0.01 to 15% by mass, particularly preferably 0.1 to 12% by mass, and 0.3 to 10%. More preferably, it is mass%.

  If desired, the colored pressure-sensitive adhesive constituting the colored pressure-sensitive adhesive layer 3 can contain a crosslinking agent. There is no restriction | limiting in particular as this crosslinking agent, Arbitrary things can be suitably selected and used from what was conventionally used as a crosslinking agent in an acrylic adhesive. Examples of such crosslinking agents include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, and metal salts. Isocyanate compounds are preferably used.

  Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, and hydrogenated diphenylmethane diisocyanate. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, etc. it can. These crosslinking agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although the compounding quantity of a crosslinking agent is based also on the kind of crosslinking agent, it is 0.01-20 mass parts normally with respect to 100 mass parts of adhesive resin (acrylic copolymer), Preferably, 0.1-10 mass Part.

  As long as the objective of the projection screen 1 which concerns on this embodiment is not impaired, various additives normally used for an acrylic adhesive, for example, a tackifier, antioxidant, ultraviolet absorption, are used for a coloring adhesive. Agents, light stabilizers, softeners and the like can be added.

  The thickness of the colored pressure-sensitive adhesive layer 3 is preferably 10 to 50 μm, and particularly preferably 15 to 35 μm. If the thickness of the colored pressure-sensitive adhesive layer 3 is less than 10 μm, it becomes difficult to impart durability performance or control the transmittance. On the other hand, if the thickness of the colored pressure-sensitive adhesive layer 3 exceeds 50 μm, manufacturing problems and diffusion characteristics are difficult. May be caused, and it is economically undesirable.

[Coating film]
The coating film 4 is a film that does not have a polarizing function. In the present embodiment, the coating film 4 is preferably a film having a reflection control layer (antireflection layer / low reflection layer) and / or an antiglare layer. Provided as a hard coat film.

  Examples of the coating film 4 include an antireflection layer (AR: Anti Reflection), a low reflection layer (LR: Low Reflection), an antiglare layer (AG: Anti Glare), an antiglare layer + a low reflection layer (AG + LR), and clear. A plastic film coated with a hard coat layer (CHC: Clear Hard Coat), a clear hard coat layer + a low reflection layer (CHC + LR), and the like can be used, and conventionally known ones can be used. The coating film 4 includes a film having a light scattering layer, but is different from the light diffusion control layer 2 in that the light scattering direction is not controlled.

  Examples of the plastic film used for the coating film 4 include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyolefin films such as polyethylene film and polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, and acetyl. Cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether ketone film, poly Ether sulfone film, polyether immi Film, fluororesin film, polyamide film, acrylic resin film, polyurethane resin film, norbornene polymer film, cyclic olefin polymer film, cyclic conjugated diene polymer film, vinyl alicyclic hydrocarbon polymer film, etc. It is done.

  A coating layer such as an antireflection layer, a low reflection layer, an antiglare layer, or a clear hard coat layer may be formed by coating a conventionally known material on the plastic film. In addition, the various coating layers described above improve the visibility by imparting scratch resistance or preventing reflection of light and the like, and do not have an effect of scattering light at a predetermined angle. Different from the light diffusion control layer 2.

  The thickness of the coating film 4 is usually about 40 to 200 μm, preferably about 80 to 150 μm.

  In this embodiment, the coating film 4 is used as the “film having no polarization function” of the present invention. However, the present invention is not limited to this, and for example, an uncoated film is used. You can also In this case, a functional layer such as a reflection control layer and an antiglare layer or a film having the functional layer can be provided separately from the projection screen 1 according to the present embodiment.

[Transparent substrate]
The transparent substrate 5 is not particularly limited as long as it is a transparent substrate having rigidity capable of supporting the light diffusion control layer 2, and a plastic plate or a glass plate is usually used.

  As a material of the plastic plate, for example, a material having excellent transparency and dimensional stability such as polycarbonate, polyarylate, polyether sulfone, amorphous polyolefin, polyethylene terephthalate, polymethyl methacrylate, and the like is used. In consideration of prevention of outgas generation such as moisture from the plastic plate in a high temperature environment, a plastic plate having hard coat layers laminated on both sides can be preferably used.

  The thickness of the transparent substrate 5 is usually about 0.5 to 10 mm, preferably about 2 to 8 mm. If it is 0.5 mm or more, rigidity when used as a screen can be imparted, and if it is 10 mm or less, it can be used without any problem in the production process.

  In addition, although the projection screen 1 which concerns on this embodiment is provided with the transparent substrate 5, it is not limited to this, The transparent substrate 5 may be abbreviate | omitted. In this case, other layers (for example, the light diffusion control layer 2, the coating film 4, and the antireflection film 6) may serve as a support.

  Here, as a bonding method between the transparent substrate 5 and the light diffusion control layer 2, various conventionally known methods can be used. For example, the joining by an adhesive sheet, the joining by an adhesive agent, the joining by lamination, etc. are mentioned preferably. In joining by lamination, an adhesive sheet or an adhesive may be used in combination. Considering the simplicity of the process and the like, joining by lamination is preferable.

  In the case of using a pressure-sensitive adhesive sheet or an adhesive in the bonding between the transparent substrate 5 and the light diffusion control layer 2, the pressure-sensitive adhesive having excellent blister resistance or the generation of outgas from the transparent substrate 5 in a high temperature environment is considered. It is preferable to use an adhesive.

  On the other hand, in the case of bonding by lamination, the light control film stack as the light diffusion control layer 2 can be laminated with the transparent substrate 5 after the light control films or the light control film stacks are laminated. Alternatively, the light diffusion control layer 2 can be formed by sequentially laminating a light control film on the transparent substrate 5 using a laminator. In view of improving the adhesion between the light diffusion control layer 2 and the transparent substrate 5, the latter is preferable.

[Antireflection film]
As the antireflection film 6, a film having a reflection control layer exemplified as the coating film 4 can be used. Specifically, a plastic coated with an antireflection layer (AR) or a low reflection layer (LR). It is preferable to use a film. Similar to the coating film 4, the antireflection film 6 is different from the light diffusion control layer 2.

  The projection screen 1 according to the present embodiment includes the antireflection film 6 on the outermost surface on the side where the projector light is incident. However, the present invention is not limited to this, and the antireflection film 6 may be omitted. Good. In this case, for example, the transparent substrate 5 may be directly coated with an antireflection layer (AR) or a low reflection layer (LR).

〔Production method〕
The projection screen 1 according to the present embodiment can be manufactured as follows using the various materials described above. In addition, the following manufacturing methods are examples and are not limited thereto.

First, as shown in FIG. 2, two light control films having the same light scattering angle region are laminated so that the light scattering angle regions coincide with each other, thereby obtaining light control film stacks 7, 8, and 9, respectively .

  Next, the light control film laminate 9 is laminated on the transparent substrate 5. Further, the light control film stack 8 is laminated so that the light scattering angle region of the light control film stack 9 and the normal direction of the light control film stack 9 are symmetrical. Thereafter, the light control film laminate 7 is laminated so as to coincide with the center line (normal direction) of the light scattering angle region of the laminated light control film laminates 9, 8, thereby allowing light on the transparent substrate 5. The diffusion control layer 2 is formed.

  The adhesive between the transparent substrate 5 and the light control film laminate 9 or between the light control film laminates 7, 8, 9 may use an adhesive or an adhesive instead of the laminate, Moreover, you may use together with a laminate.

  On the other hand, a colored pressure-sensitive adhesive layer 3 is formed by applying and drying a colored pressure-sensitive adhesive on the side opposite to the coating layer of the coating film 4. Next, the light diffusion control layer 2 is bonded so that the exposed surface side of the light diffusion control layer 2 is in contact with the exposed surface side of the colored pressure-sensitive adhesive layer 3.

  Moreover, the adhesive which consists of a composition remove | excluding a coloring agent among the adhesives mentioned as said coloring adhesive on the surface on the opposite side to the surface in which the reflection control layer of the antireflection film 6 is provided. An adhesive layer is provided by drying. And the projection screen 1 is obtained by bonding so that the adhesive layer provided on the antireflection film 6 may contact the exposed surface side of the transparent substrate 5.

  The obtained projection screen 1 is preferably subjected to pressure treatment such as autoclave treatment in order to strengthen the bonding strength between the respective layers. The autoclave treatment is preferably performed at a temperature of 50 to 70 ° C. and a pressure of 0.5 to 2.0 MPa for 10 to 100 minutes. Instead of the autoclave process, other various pressure processes such as a pressure bonding process using a pressure roller may be performed.

  For the application of the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer on the colored pressure-sensitive adhesive layer 3 and the antireflection film 6, a known coating method can be used, for example, a bar coating method, a knife coating method, A roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used to coat the pressure-sensitive adhesive to form a coating film and to dry the coating. The drying conditions are not particularly limited, but are usually about 10 seconds to 10 minutes at 50 to 150 ° C. Moreover, when coating an adhesive, a solvent can be used. It does not specifically limit as a solvent, For example, toluene, ethyl acetate, methyl ethyl ketone, etc. are mentioned preferably.

  In the projection screen 1 described above, the colored pressure-sensitive adhesive layer 3 can suppress backscattering of light incident from the front of the screen, and at the same time, the black luminance of the projector light can be reduced, thereby improving the contrast. be able to. Furthermore, since a polarizing plate is not used, there is no problem of warping, and it can be manufactured at a low cost, and the configuration can be simplified.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
<Preparation of photocurable composition for light control film>
Obtained by reaction of polypropylene glycol having a weight average molecular weight of about 3,000 with 0.3 mol of tolylene diisocyanate, 2.7 mol of hexamethylene diisocyanate and 2 mol of 2-hydroxyethyl acrylate per 2 mol of the polypropylene glycol. Polyether urethane acrylate (refractive index 1.460) 40 parts by mass, 2,4,6-tribromophenyl acrylate (refractive index 1.6 or more) 30 parts by mass, 2-hydroxy-3-phenoxypropyl acrylate (Refractive index 1.526) 30 parts by mass and 2-hydroxy-2-methylpropiophenone 1.5 parts by mass were added and mixed to obtain a photocurable composition for a light control film.

<Production of light control film and light control film laminate>
The photocurable composition was applied onto a film-like transparent polyethylene terephthalate (hereinafter referred to as “PET film”) so that the thickness after drying was 170 μm.

An 80 W / cm rod-shaped high-pressure mercury lamp is fixed at a position 80 cm above the coating film, and is applied at a speed of 1 m / min through a light-shielding plate with a slit so that light shines vertically on the entire coating film surface. The PET film with film was irradiated with light while moving in the lateral direction to form a light control film. At this time, by adjusting the width and the angle of the slit, two types of light control films having a light scattering angle region showing a haze value of 60% or more having the following values were produced.
(1) Light control film having a light scattering angle range of 85 to 115 ° (width: 30 °; corresponding to 8a, b and 9a, b in FIG. 2): 4 sheets produced (2) Light scattering angle range of 85 to 135 ° Light control film (width: 50 °; corresponding to 7a and b in FIG. 2): 2 sheets produced Note that the value of the light scattering angle region showing a haze value of 60% or more was measured with a conoscope.

  The obtained light control film was peeled off from the PET film, and two light control films having the same light scattering angle region were laminated so that the light scattering angle regions coincided to obtain a light control film laminate. That is, light control film stacks corresponding to the light control film stacks 7, 8 and 9 of FIG. 2 were obtained.

<Preparation of light diffusion control layer>
Next, the light control film laminate 9 was laminated on an acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., “Acrylite L # 001”, thickness 2 mm) as a transparent substrate 5 using a laminator. Further, the light control film laminate 8 was laminated by using a laminator so that the diffusion angle region was symmetric with the light control film laminate 9.

  Finally, the light diffusion control layer 2 was formed by similarly laminating the light control film laminate 7. In the light diffusion control layer 2, the point light source incident from the normal direction diffuses in the vertical direction of 65 to 115 ° and in the horizontal direction of 45 to 135 °. Thus, the laminated body in which the light-diffusion control layer 2 was formed on the acrylic board was obtained.

<Preparation of colored adhesive layer>
Next, with respect to 100 parts by mass of an acrylic copolymer (butyl acrylate: methyl acrylate: acrylic acid (mass ratio) = 76: 20: 4, Mw = 900,000, solid content concentration 28% by mass), a crosslinking agent (Japan 0.75 parts by mass of Polyurethane Co., Ltd., “Coronate L”, solid content concentration of 100% by mass, chromium complex dye as a colorant (Hodogaya Chemical Co., Ltd., “Spiron Black MH”, solid content concentration of 30% by mass) ) Was added and blended to obtain a colored pressure-sensitive adhesive composition. This colored pressure-sensitive adhesive composition was coated on a heavy peelable release film (manufactured by Lintec Corporation, “SP-PLR38T103-1”) so that the film thickness after drying was 25 μm. After coating, the colored pressure-sensitive adhesive layer 3 was obtained by drying at 90 ° C. for 1 minute.

  On the exposed surface side of the obtained colored pressure-sensitive adhesive layer 3, a light release type release film (manufactured by Lintec Corporation, “SP-PET 381031”) was bonded to obtain a colored pressure-sensitive adhesive layer 3 having release films on both sides. The luminous transmittance Y of the colored pressure-sensitive adhesive layer 3 was 58%. A method for calculating the luminous transmittance will be described later.

<Production of projection screen>
The light release release film of the colored pressure-sensitive adhesive layer 3 having a release film on both sides is peeled off, and the exposed surface of the colored pressure-sensitive adhesive layer 3 is an antireflection film as a coating film 4 (manufactured by Toppan Printing Co., Ltd., “LR-TAC”). It was bonded to the opposite side of the coating layer.

  Next, the heavy release type release film on the colored pressure-sensitive adhesive layer 3 is peeled off, and the exposed surface of the colored pressure-sensitive adhesive layer 3 is pasted on the light diffusion control layer 2 of the laminate of the acrylic plate and the light diffusion control layer 2. Combined. Up to this point, a structure composed of “coating film 4 (antireflection film) / colored adhesive layer 3 / light diffusion control layer 2 / transparent substrate 5 (acrylic plate)” was obtained.

  On the other hand, a pressure-sensitive adhesive layer having a release film on both sides was prepared except that the colorant was removed from the colored pressure-sensitive adhesive layer 3. The light peelable release film of the pressure-sensitive adhesive layer was peeled off, and the exposed surface of the pressure-sensitive adhesive layer was bonded to the side opposite to the reflection control layer of the antireflection film 6 (manufactured by Toppan Printing Co., Ltd., “LR-TAC”).

  Further, the heavy release type release film of the pressure-sensitive adhesive layer having no colorant is peeled off, and the above-mentioned “coating film 4 (antireflection film) / colored pressure-sensitive adhesive layer 3 / light diffusion control layer 2 / transparent substrate 5 (acrylic plate)”. It was bonded to the acrylic plate side surface of the structure consisting of "".

  Finally, in order to improve interlayer adhesion, the projection screen 1 was obtained by processing at 50 ° C., 0.9 MPa for 1 hour in an autoclave (manufactured by Kurihara Seisakusho).

[Example 2]
As a colorant for the colored adhesive layer, 3.5 parts by mass of a black pigment (manufactured by Toyo Ink Co., Ltd., carbon black-containing product, “GS05-2”, solid content concentration 10% by mass) instead of the chromium complex dye of Example 1 A colored pressure-sensitive adhesive layer 2 having a release film on both sides and a projection screen 1 were produced in the same manner as in Example 1 except that the above was used. The luminous transmittance Y of the colored pressure-sensitive adhesive layer 2 was 58%.

Example 3
As a colorant for the colored pressure-sensitive adhesive layer, instead of “Spiron Black MH” manufactured by Hodogaya Chemical Co., Ltd. in Example 1, “Valifast Black 3808” manufactured by Orient Chemical Co., Ltd., which is a metal complex dye (solid content concentration: 100% by mass) A colored pressure-sensitive adhesive layer 2 having a release film on both sides and a projection screen 1 were produced in the same manner as in Example 1 except that 0.1 part by mass was used. The luminous transmittance Y of the colored pressure-sensitive adhesive layer 2 was 58%.

[Comparative Example 1] (Control)
A pressure-sensitive adhesive layer having a release film on both sides and a pseudo-projection screen were prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive layer was formed without adding a colorant in the colored pressure-sensitive adhesive layer of Example 1. The luminous transmittance Y of the pressure-sensitive adhesive layer was 100%.

[Comparative Example 2]
On the polarizing plate (manufactured by Sanlitz), the pressure-sensitive adhesive composition containing no colorant in the colored pressure-sensitive adhesive of Example 1 was applied so that the thickness after drying was 25 μm to form a pressure-sensitive adhesive layer. This was a laminate of a pressure-sensitive adhesive layer and a polarizing plate. The luminous transmittance Y of this laminate was 52%.

  A projection screen was prepared in the same manner as in Example 1 except that the laminate of the pressure-sensitive adhesive layer and the polarizing plate was used instead of the laminate of the colored adhesive layer 3 and the coating film 4 in Example 1.

[Test Example 1] (Measurement of backscattering)
The projection screens obtained in Examples and Comparative Examples were cut into 70 mm × 150 mm, and this was used as Sample 10. The coating film 4 side of the sample 10 (the polarizing plate side in Comparative Example 2) was the front side, and the black box 11 was placed on the back side of the sample 10 as shown in FIG. 3 to remove the influence of reflected light. By measuring in the absence of projector light as an image, it is possible to measure purely the influence of backscattering.

White projector light (265 lx: measured with “3423LUX HiTESTER” manufactured by HIOKI) from the projector P is incident on the front side of the sample 10 from the direction of 15 ° and 60 ° from the projector P, and the screen brightness of the sample 10 ( cd / m ² ) was measured from an angle of 0 ° (measured with a luminance meter LS-110 manufactured by Minolta). The results are shown in Table 1.

Here, the smaller the screen brightness value at each of the white light incident angles of 15 ° and 60 ° in Table 1, the more effectively backscattering is suppressed, and at least Comparative Example 1 that does not contain a colorant ( If it is significantly smaller than the value of the screen brightness in (control), it can be seen that backscattering is suppressed. In addition, since it is dependent on the intensity | strength of ambient light, etc. about backscattering, a clear reference | standard cannot be provided, but in this test example, it is 1.50 cd / m < ² > or less in white light incident angle 15 degrees, and white light incident angle If it is suppressed to a value of 0.30 cd / m ² or less at 60 °, it is considered that backscattering does not cause a problem in practice.

[Test Example 2] (Durability test)
Samples obtained by cutting the projection screens obtained in Examples and Comparative Examples to 70 mm × 150 mm were used as samples, put in an environment of 80 ° C. dry conditions and 60 ° C./90% wet heat conditions, taken out after 500 hours, and 23 ° C. After being left for 2 hours, it was placed on a horizontal surface, and the presence or absence of warpage from the horizontal surface was visually evaluated. The case where no warpage was visually observed was indicated as “◯”, and the case where warpage was recognized as “X”. The results are shown in Table 1.

[Test Example 3] (Measurement of hue change over time)
The light release release film of the colored pressure-sensitive adhesive layer 3 (the pressure-sensitive adhesive layer in Comparative Example 1) having release films on both sides obtained in Examples and Comparative Examples was peeled off, and the exposed surface was a PET film (manufactured by Toyobo Co., Ltd., “Cosmo Sine PET100 A4300 "). Further, the laminate of the colored pressure-sensitive adhesive layer 3 and the PET film was cut into a length of 50 mm × width of 100 mm, the heavy peelable release film was peeled off, and soda lime glass (length 70 mm × width 150 mm × 1.1 mm, NS It was pasted on (made by J-Presion).

  Then, the structure which consists of "PET film / coloring adhesive layer 3 / soda lime glass" obtained above was processed with an autoclave at 50 ° C, 0.9 MPa for 1 hour to obtain a sample for evaluation. In Comparative Example 2, a structure composed of “polarizing plate / adhesive layer (not including colorant) / soda lime glass” was used as an evaluation sample.

  About the obtained sample for evaluation, using a spectrophotometer (manufactured by Shimadzu Corporation, “MPC3100”), luminous transmittances Y, x and y and hue changes ΔY, Δx and Δy based on the CIE1931 chromaticity diagram were calculated. Calculated. The results are shown in Table 1.

  In addition, the sample for evaluation was put in an environment of 80 ° C. dry condition and 60 ° C./90% wet heat condition in the same manner as the durability test described above, and the luminous transmittances Y, x and y were similarly changed after 500 hours. , And hue changes ΔY, Δx, and Δy were calculated. The results are shown in Table 1.

  As is clear from Table 1, it was confirmed that any of the projection screens obtained in Examples 1 to 3 can suppress backscattering. Further, the projection screens of Examples 1 and 2 have smaller ΔY, Δx, and Δy after the durability test than the projection screen of Example 3, and are excellent in the effect of suppressing backscattering after the durability test. Was confirmed. Further, the projection screens of Examples 1 to 3 were free from warping as in Comparative Example 2 using a polarizing plate.

[Test Example 4] (Consideration on contrast)
As a general value when projector light is projected, assuming that the white state screen luminance of Comparative Example 1 (control) is 300 cd / m ² and the black state screen luminance is 1 cd / m ² , the contrast including backscattering is ( 300 + 2.60) :( 1 + 2.60) ≈84.06: 1, and considering that the transmittance is lowered in Example 1 (300 × 0.58 + 0.59): (1 × 0.58 + 0) .59) ≈149.2: 1. Thereby, even if the transmittance | permeability was lowered | hung with the colored adhesive layer, it confirmed that a high contrast ratio could be taken out.

  The projection screen of the present invention is suitably used as a transmission projection screen for a rear projection display from the viewpoints of visibility, durability, economy, and the like.

P ... Projector 1 ... Projection screen 2 ... Light diffusion control layer 3 ... Colored adhesive layer 4 ... Coating film (film having no polarizing function)
DESCRIPTION OF SYMBOLS 5 ... Transparent substrate 6 ... Antireflection film 7, 8, 9 ... Light control film laminated body 7a, 7b, 8a, 8b, 9a, 9b ... Light control film 10 ... Sample 11 ... Black box

Claims (11)

A transmissive projection screen used for a rear projection display,
A light diffusion control layer for controlling light diffusion;
A film that does not have a polarizing function;
A colored adhesive layer interposed between the light diffusion control layer and the film having no polarization function ,
The colored adhesive layer is colored with a metal complex dye,
The projection screen, wherein the colored pressure-sensitive adhesive layer has a thickness of 10 to 35 m .   The light diffusion control layer includes a light control film obtained by irradiating and curing a film of a composition containing at least two kinds of photopolymerizable compounds having a difference in refractive index. The projection screen according to claim 1.   The projection screen according to claim 2, wherein the light diffusion control layer is a laminated body in which the light control films are stacked in a direction in which light scattering angle regions substantially coincide with each other. The color change of transmitted light by the colored pressure-sensitive adhesive layer is within ± 0.0030 in hue changes Δx and Δy defined by the CIE1931 chromaticity diagram, and the luminous transmittance Y of the colored pressure-sensitive adhesive layer projection screen according to claim 1, characterized in that but is 15 to 90%. The metal complex salt dyes, projection screen according to claim 1, characterized in that the chromium complex dye. Film not having the polarizing function, the projection screen according to any one of claims 1 to 5, characterized in that a hard coat film. The projection screen according to any one of claims 1 to 6 , wherein the film having no polarization function is a film having a reflection control layer and / or an antiglare layer. Projection screen according to any one of claims 1 to 7, characterized in that it comprises an anti-reflection layer on the outermost layer of the projector. Projection screen according to any one of claims 1-8, characterized in that it comprises a transparent substrate. In order from the projector side, and the transparent substrate, and the light diffusion control layer, and the colored adhesive layer, any of claims 1-7, characterized in that formed by laminating a film having no said polarizing function The projection screen according to one item . The projection screen according to claim 10 , wherein an antireflection layer is provided on the projector side of the transparent substrate.

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