JP2000297139A - Composition for flexible light-scattering film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for preparing an anisotropic scattering body which shows an anisotropy in its scattering property (forward or back scattering, dependence on the angle of incidence), allows easy control of the scattering properties in the vertical-horizontal scattering range and does not change the color of the display light depending on the view point. SOLUTION: A composition composing a light-scattering film having a light- scattering property showing a selectivity against the angle of incidence and functions as a mere transparent film against a light perpendicular against the inclining direction. Here, the composition comprises multiple (A) compounds having at least one oxirane ring in the molecule, (B) radically polymerizable compounds and (C) photopolymerization initiators generating cation species and radical species via chemoradiation, wherein the compound (A) and compound (B) differ in their refractive index.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has different scattering properties depending on the incident angle of light (or has incident angle selectivity).
In addition, the present invention relates to a composition for a light diffusion film having anisotropic light scattering characteristics.

[0002]

2. Description of the Related Art In a display device utilizing light, such as a reflection type liquid crystal display device or a transmission type liquid crystal display device, a viewing angle at the time of observation is secured (that is, a brightly displayed image is displayed on the front surface of the display device). For example, a light-diffusing film is disposed on the front of the apparatus for the purpose of showing the display screen with uniform brightness over the entire display screen. As a conventional light scattering film, a resin film whose surface is processed into a mat shape, a resin film containing a diffusing material inside, and the like are used.

[0003] In the case of a conventional resin film processed into a mat shape or a film containing a diffusing material inside, it is difficult in principle to provide a function such as a change in scattering depending on the incident angle of incident light. It does not have such a function.

In the case of a light-scattering film whose surface is processed into a mat shape, the film surface is physically formed with a matte surface such as a sandblaster treatment, or chemically matted by a dissolution treatment with an acidic or alkaline solution. To form Therefore, it is difficult to control the light scattering property, and it is impossible to change the vertical and horizontal scattering properties, so that it is not possible to impart scattering anisotropy.

[0005] In a light-scattering film containing a diffusing material therein, attempts have been made to control the refractive index, size, shape, etc. of the diffusing material in order to control the scattering.
At present, it is technically difficult and not sufficiently practical.

Accordingly, the above-mentioned light-scattering film has no scattering angle dependence and no or little anisotropy of light scattering, so that when used in a display device, unnecessary scattered light is generated. As a result, there is a problem that the brightness and contrast of display are reduced or a displayed image is blurred.

On the other hand, as a proposal relating to a reflection type liquid crystal display device using a scattering plate having anisotropic light scattering, Japanese Patent Application Laid-Open No. Hei 8-2
No. 0180 is known. The scattering plate disclosed in the above publication is a scattering plate having almost no back scattering characteristics and strong forward scattering characteristics, and selectively scatters either the incident light to the liquid crystal display device or the display light emitted from the liquid crystal display device. It has the property to make it.

However, the above publication does not specifically describe the structure of the scattering plate, but only describes "the transparent fine particles hardened with a transparent polymerizable polymer".
In such a scattering plate, as in the case of the "light diffusion film containing a diffusion material therein", even if the scattering characteristics are given anisotropy (forward or backward), the scattering in the vertical and horizontal directions is not possible. It is difficult to control even the characteristics.

As a proposal for a transmission type liquid crystal display device using a hologram as a scattering plate, see Japanese Patent Application Laid-Open No. 9-152.
No. 602 is known. The above proposal scatters display light emitted from a liquid crystal display device having a backlight, and employs a hologram as a scattering plate. Although it is possible to control the horizontal scattering characteristics, it is inevitably accompanied by spectral dispersion (wavelength dispersion), so that the color of the display light changes and is visually perceived as the viewpoint to be observed is moved. Will be.

[0010]

SUMMARY OF THE INVENTION According to the present invention, it is possible to provide anisotropic scattering properties (depending on the forward or backward direction and the incident angle) and to control the scattering properties in the vertical and horizontal scattering ranges. An object of the present invention is to provide a composition for obtaining an anisotropic scatterer that is easy and does not change the color of display light depending on the observation position.

[0111]

According to the anisotropic scattering film obtained from the present invention, a portion having a different refractive index is distributed in an irregular shape and thickness inside the film, so that the light and shade having a high and low refractive index can be obtained. Patterns are formed, and by optimizing the size, shape, and distribution of the portions with different refractive indexes along the vertical and horizontal directions on the film surface and the thickness direction of the film, the scattering characteristics depending on the incident angle In addition to having a change, light scattering in unnecessary directions is eliminated, and light is scattered only in necessary directions (ranges). An object of the present invention is to provide a composition for an anisotropic scattering film, comprising a radical polymerizable compound.

In the composition for a flexible light-scattering film according to the first aspect, a portion having a different refractive index is distributed in an irregular shape and thickness, thereby forming a light and shade pattern having a high and low refractive index. A light scattering film having a structure in which portions having different refractive indices are inclined and distributed in a layered manner with respect to the thickness direction of the film, and light incident at an angle along the inclined direction. For light scattering occurs, for the light perpendicular to the tilt direction, such as a function as a mere transparent film, the composition constituting the light scattering film having an incident angle selectivity in light scattering, A plurality of (A) compounds having at least one oxirane ring in the molecule, and (B)
A compound having radical polymerizability; (C) a photoinitiator that generates a cationic species and a radical species by actinic radiation; (A) a compound having at least one oxirane ring in the molecule; and (B) having radical polymerizability. It is characterized in that there is a difference in the refractive index of the compound.

[0013] The composition for a flexible light-scattering film according to claim 2 includes: A) a compound represented by the general formula (1) among a plurality of compounds having at least one oxirane ring in the molecule:

Embedded image (In the formula, m + n is 2 or more, and R represents a linear alkyl group having 1 to 5 carbon atoms (C).) And a general formula (2)

Embedded image (In the formula, m + n is 2 or more, and R represents a straight-chain alkyl group having 1 to 5 carbon atoms.) And the general formula (3)

Embedded image (In the formula, m + n corresponds to 4 to 8, and R represents a linear alkyl group having 1 to 5 carbon atoms (C).)
Alternatively, it is characterized by comprising at least one selected from bisphenol A diglycidyl ether polymerized fatty acid adduct and polymerized fatty acid polyglycidyl ester.

A sensitizing dye (D) for sensitizing a photoinitiator (C) which generates a cationic species and a radical species by actinic radiation is added to the composition for a flexible light-scattering film according to the third aspect. It is characterized by the following.

In the composition for a flexible light-scattering film according to claim 4, the compound (B) having radical polymerizability has a refractive index higher than that of the compound (A) having at least one oxirane ring in the molecule. It is a compound having a low temperature, a liquid at normal temperature and normal pressure, and a boiling point of 100 ° C. or higher at normal pressure and having at least one ethylenically unsaturated bond.

The composition for a flexible light-scattering film according to the fifth aspect is characterized in that (A) 100 parts by weight of a compound having at least one oxirane ring in a molecule is compounded with a compound (B) having radical polymerizability. Characterized by mixing 20 to 80 parts by weight

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows that the portions having different refractive indexes have irregular shapes.
It is explanatory drawing which shows the light-scattering film 1 in which the density pattern which distributed in thickness and the refractive index was high and low (it represents with black and white in the figure) was formed, the left is a top view, and the right is a cross section. FIG.

As can be seen from the plan view, the shape of the portion having a different refractive index is horizontally long. Further, as can be seen from the cross-sectional view, the portions having different refractive indexes have a structure distributed in a layer shape inclined with respect to the thickness direction of the film. In FIG. 1, the distribution of the refractive index is uniform (the color does not change in the inclined direction) in the direction in which the portions having different refractive indexes are inclined in layers.

FIG. 2 is an explanatory view showing a light-scattering film 1 according to another embodiment, wherein the left is a plan view and the right is a cross-sectional view. In FIG. 2, the shape of the portion having a different refractive index is vertically long,
In addition, in the direction in which the portions having different refractive indices are inclined in a layered manner, the distribution of the refractive index is irregular (the color changes even in the inclined direction).

First, the optical characteristics of the light-scattering films shown in FIGS. Light scattering occurs for light incident at an angle along the above-mentioned inclination direction in which portions having different refractive indices are distributed in layers (an angle θ from the perpendicular to the film, in the direction of arrow 2 in FIG. 2). Become.

An angle perpendicular to the inclination direction (arrow 3 in the figure)
), It functions as a mere transparent film, and the incident light exits without being scattered.

Next, considering a plan view, when the shape of the portion having a different refractive index is vertically long (or horizontally long), when the light incident on that portion is scattered and emitted, It has anisotropy such that the light scattering characteristics are horizontally long (or vertically long). In FIG. 1, the emitted light is scattered vertically because the shape is horizontal, and in FIG. 2, the emitted light is scattered horizontally because the shape is vertical.

FIG. 3 is a graph showing an example of the incident angle dependency of the light scattering film 1 produced using the composition of the present invention. As shown by the solid line in the figure, the haze value is 80% or more for light in a specific incident angle range (0 to 60 degrees in the figure), and conversely, the incident angle is symmetric (−60 degrees in the figure). The haze value with respect to the light of (from 0 ° to 0 °) is 20% or less, which indicates the scattering angle dependence in the present specification.

Further, as described above, when the shape of the portion having a different refractive index is vertically long (or horizontally long), when the light incident on the portion is scattered and emitted, the light emitted from each portion is emitted. It has anisotropy such that its scattering characteristics are horizontally long (or vertically long). For example, if the shape is horizontally long as shown in FIG. 1, the scattered light emitted from the light scattering film has a distribution such that it becomes a vertically long ellipse as shown in FIG.

Next, the composition for an anisotropic light scattering film of the present invention will be described in detail. As described above, the inside of the anisotropic light-scattering film made of the composition of the present invention forms a light and shade pattern composed of high and low refractive indexes by distributing portions having different refractive indexes in an irregular shape and thickness. Have been.

If the difference in the refractive index is too small, the scattering property deteriorates. On the contrary, if the difference is too large, light scattering occurs regardless of the incident angle of the light. It becomes difficult to have dependencies.

(A) used in the composition of the present invention
A compound having at least one oxirane ring in the molecule is a compound having an oxirane ring that is polymerized or cross-linked by actinic radiation in the presence of an initiator that generates a cation by actinic radiation, such as an epoxy compound or a cyclic ether. It is composed of one or a mixture of two or more of compounds, cyclic lactone compounds, cyclic acetal compounds and the like. Among such compounds having an oxirane ring, compounds having at least one epoxy group in one molecule are preferable, and examples thereof include conventionally known aromatic epoxy resins and alicyclic epoxy resins.

Preferred as the aromatic epoxy resin is a polyglycidyl ether of a polyhydric phenol having at least one aromatic ring or an alkylene oxide adduct thereof, such as bisphenol A or an alkylene oxide adduct thereof and epichlorohydrin. Glycidyl ether and epoxy novolak resin produced by the reaction are exemplified. Bisphenol A, Bisphenol AD, Bisphenol B, Bisphenol A
Epoxy compounds produced by a condensation reaction of various phenol compounds of F, bisphenol S, brominated bisphenol A, novolak, o-cresol novolak, and p-alkylphenol novolak with epichlorohydrin can be mentioned. Since the brominated bisphenol A epoxy compound becomes insoluble in a solvent when the epoxy equivalent is increased, it is effective to use the epoxy compound in a mixed system without using it alone.

Representative examples of alicyclic epoxy resins include hydrogenated glycidyl ethers prepared by the reaction of bisphenol A or an alkylene oxide adduct thereof with epichlorohydrin, particularly hydrogenated bisphenol A, hydrogenated bisphenol AD, Hydrogenated bisphenol B,
Examples include hydrogenated bisphenol AF, hydrogenated bisphenol S, hydrogenated brominated bisphenol A, and the like.

Among the compounds having an oxirane ring, the molecular weight is 400 to 1000, except for epoxy compounds formed by the condensation reaction of various phenolic compounds such as volak, o-cresol novolak and p-alkylphenol novolak with epichlorohydrin. If it is smaller than this, it becomes a liquid, and it cannot be obtained as a film unless a curing treatment by pre-treatment is performed, and uniform coating cannot be performed. If the molecular weight is larger than this range, no characteristics can be obtained.

Further, when the above-mentioned cross-linking with only the epoxy resin is performed, the formed film is hard and has a low tendency to have poor flexibility. The range expands. Specifically, the general formula (1)

[0032]

Embedded image

Wherein m + n is 2 or more, and R represents a straight-chain alkyl group having 1 to 5 carbon atoms (C).

[0034]

Embedded image

(Wherein, m + n is 2 or more, and R represents a straight-chain alkyl group having 1 to 5 carbon atoms (C)).

[0036]

Embedded image

(Where m + n is a value corresponding to 4 to 8), or bisphenol A diglycidyl ether polymerized fatty acid adduct, polymerized fatty acid polyglycidyl ester, and the like.

(B) used in the composition of the present invention
A compound having radical polymerizability is a compound having radical polymerizability that is polymerized or cross-linked by actinic radiation in the presence of an initiator that generates radicals by actinic radiation. It contains at least one or more unsaturated bonds, contains a polyfunctional vinyl monomer in addition to a monofunctional vinyl monomer, and may be a mixture thereof.

Specifically, high-boiling vinyl monomers such as (meth) acrylic acid, itaconic acid, maleic acid, (meth) acrylamide, diacetone acrylamide, and 2-hydroxyethyl (meth) acrylate; Hydroxy compounds, such as ethylene glycol,
Diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, neopentyl glycol, 1,3-propanediol, 1,4
-Butanediol, 1,5-pentanediol, 1,6
Di- or poly (meth) acrylates such as -hexanediol, 1,10-decanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, and mannitol; and the like, but are not limited thereto. The refractive index of the compound (A) having at least one oxirane ring in the molecule used for the present invention and the refractive index of the compound (B) having radical polymerizability need to be different from each other. The greater the value, the greater the degree of light scattering, the so-called haze ratio. Generally, it is preferable that the refractive index difference is 0.01 or more, more preferably 0.05 or more. Here, since there are a plurality of (A) compounds having at least one oxirane ring in the molecule, the value obtained by taking into account the additive properties of the refractive indices and (B) the refractive index of the compound having radical polymerizability are used. It is needless to say the difference.

(C) used in the composition of the present invention
As a photoinitiator system that generates a radical species and a cationic species by actinic radiation, J. Pharm. Photochem. Sc
i. Technol. , 2,283 (1987). Compounds, specifically iron arene complex, trihalogenomethyl-substituted s-triazine, sulfonium salt, diazonium salt, phosphonium salt, selenonium salt,
Arsonium salts, iodonium salts and the like, and examples of iodonium salts include Macromolecule
s, 10 , 1307 (1977). And diphenyliodonium, ditolyliodonium, phenyl (p-anisyl) iodonium, bis (m
-Nitrophenyl) iodonium, bis (p-tert-butylphenyl) iodonium, bis (p-chlorophenyl) iodonium and the like iodonium chloride, bromide, or borofluoride, hexafluorophosphate salt, hexafluoroarsenate salt, and aromatic Group sulfonates and the like.

The sensitizing dye (D) for sensitizing the photoinitiator (C) which generates a cationic species and a radical species by actinic radiation according to the present invention includes cyanine or merocyanine derivatives, coumarin derivatives, chalcone derivatives, xanthene derivatives. Organic dye compounds such as derivatives, thioxanthene derivatives, azurenium derivatives, squarylium derivatives, and porphyrin derivatives can be used. In addition, "Dye Handbook" (Shin Okawara et al., Kodansha 1986), "Functional Dye Chemistry" (Shin Okawara et al.) Hen, CMC 1981
And "sensitizers" described in "Specially Functional Materials" (CEM 1986, edited by Chusaburo Ikemori et al.). It should be noted that the present invention is not limited to these, and any other dyes and sensitizers that absorb light in the visible region can be used. These may be used in two or more at any ratio as needed.

The amount of component (B) contained in the composition of the present invention can be in the range of 20 to 200 parts by weight, preferably 30 to 100 parts by weight, per 100 parts by weight of (A). Department. The amount of the photoinitiator of the component (C) is 0.1 to 20 parts by weight based on 100 parts by weight of the component (A).
Preferably it is 1 to 10 parts by weight. Further, the amount of the sensitizer is from 0.1 to 10 based on 100 parts by weight of the component (A).
It can be in parts by weight, preferably in the range from 0.5 to 5. The amount of component (D) can range from 0.1 to 5 parts by weight, preferably from 0.2 to 0.5 part by weight, per 100 parts by weight of (A). The amount used is limited by the thickness of the photosensitive layer and the optical density of the thickness. That is, it is preferable to use the optical density within a range not exceeding 2.

The photosensitive solution obtained by appropriately selecting these components and mixing them in an arbitrary ratio is coated with a known coating means such as a bar coater, an applicator, a doctor blade, a roll coater, a die coater, and a comma coater. Is applied to a substrate such as a glass plate.

When the photosensitive solution is applied, it may be diluted with an appropriate solvent if necessary. In that case, however, it is necessary to apply the solvent on a substrate and then dry it. Examples of the solvent include dichloromethane, chloroform, acetone, 2-butanone, cyclohexanone, ethyl acetate, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, and 2-methoxyethyl acetate. Ethyl ether,
2-ethoxyethyl ether, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate,
Examples include tetrahydrofuran and 1,4-dioxane.

Furthermore, since the difference in the refractive index that can be recorded is limited by the manufacturing method and the recording material, the film thickness is small when the difference is large, and is reduced when the difference is small. By increasing the thickness, a light-scattering film can be realized using the composition of the present invention.

The size of the portions having different refractive indices is random and non-regular in order to cause light scattering, but has an average size of 0.1 μm to 3 mm in diameter in order to have necessary scattering properties.
It is appropriately selected within the range of 00 μm according to the scattering property required for each application.

The distribution of the portions having different refractive indices on the film surface is random and irregular in order to cause light scattering, but in order to impart necessary scattering properties, the average refractive index of the entire film is required. Is defined as <n>, the probability distribution exhibits a normal distribution centered on <n>. Alternatively, the refractive index n may be distributed according to a probability distribution that takes a maximum value at a minimum value n _min and monotonically decreases exponentially to a maximum value n _max of the refractive index, or a probability distribution that monotonically increases.

Hereinafter, means for producing the light scattering film of the present invention will be described. The light scattering film of the present invention can be produced by an optical exposure means. FIG. 5 is an explanatory diagram showing an example of an optical system manufactured using a random mask pattern. Ultraviolet light emitted from the UV light source 6 is converted into collimated light 8 by a collimating optical system 7 to irradiate a mask master 9.

The photosensitive material 5 is disposed in close contact with the surface of the mask original 9 opposite to the UV irradiation side, and the pattern of the mask original 9 is exposed to light. At this time, since the UV parallel light 8 and the mask master 9 are arranged at a predetermined angle α as shown in the figure, the pattern exposure is performed at a predetermined angle in the photosensitive material 5. This angle is
The angle corresponds to the angle of inclination of a portion having a different refractive index in the light scattering film (that is, the scattering angle θ depending on the incident angle). Therefore, the angle is appropriately set in the range of about 0 to 60 degrees depending on the application. select.

The photosensitive material 5 used here is UV
A photosensitive material that can record exposed and unexposed areas of light in the form of changes in the refractive index. It must have a higher resolving power than the density pattern to be recorded, and be capable of recording patterns in the thickness direction. There is.

The mask master 9 having a predetermined random pattern used in FIG. 5 converts black-and-white pattern data produced by random number calculation using a computer into a metal chrome pattern 11 on a glass substrate 10 by a so-called photolithography technique. Etched ones may be used. Of course, the method of producing the mask master is not limited to the above-mentioned method, and it is well known that a similar mask can be produced by a lithography method using a squirrel plate.

FIG. 6 is an explanatory view showing an example of an optical system for producing a light scattering film having the structure shown in FIG. 2 using a speckle pattern. A ground glass 15 is irradiated with laser light 14 emitted from a laser light source 13. Ground glass 15
The photosensitive material 5 is disposed at a predetermined distance F on the surface opposite to the laser irradiation side, and the photosensitive material 5 is exposed and irradiated with a speckle pattern, which is a complicated interference pattern generated by laser light transmitted and scattered by the ground glass 15. Is done.

At this time, since the ground glass 10 and the photosensitive material 5 are arranged at a predetermined angle α as shown in the figure,
The speckle pattern is exposed at a predetermined angle in the photosensitive material. Since this angle corresponds to the inclination of the portion having a different refractive index in the light scattering film (that is, the scattering peak angle θ depending on the incident angle), the angle is about 0 to 60 degrees depending on the application. Select appropriately within the range.

The laser light source used for recording was an argon ion laser 514.5 nm, 488 nm or 45 nm.
Among the wavelengths of 7.9 nm, they can be appropriately selected and used according to the sensitivity of the photosensitive material. In addition, other than an argon ion laser, any laser light source having good coherence can be used. For example, a helium neon laser or a krypton ion laser can be used.

The speckle pattern is a bright and dark spot pattern generated when light having good coherence is scattered and reflected or transmitted on a rough surface, and light scattered by minute irregularities on the rough surface interferes in an irregular phase relationship. It is caused by

Description of “Optical Measurement Handbook Asakura Shoten Toshiharu Mitsuyuki et al., Published November 25, 1994” (p. 26)
6 to p. According to 268), in a speckle pattern in which the density and phase show random values depending on the position, the size of the pattern is inversely proportional to the angle at which the diffusion plate is viewed from the photosensitive material, and the average diameter of the pattern is determined. Is done. Therefore, when the size of the diffusion plate is made larger in the vertical direction than in the horizontal direction, the pattern recorded on the photosensitive material is finer in the vertical direction than in the horizontal direction.

The speckle pattern according to the manufacturing method using the optical system shown in FIG. 6 shows that the wavelength λ of the laser beam to be used, the size D of the ground glass, and the distance F between the ground glass and the photosensitive material are as follows.
The average size d of the speckle pattern to be recorded is determined, and is generally expressed by the following equation. d = 1.2λF / D

The average length t of the speckle pattern in the depth direction is represented by t = 4.0λ (F / D) ² .

As described above, the light scattering film of the present invention having a desired three-dimensional refractive index distribution can be obtained by optimizing the values of λ and F / D so as to have optimum scattering properties.

As an example, when λ = 0.5 μm, F / D =
Assuming that 2, d = 1.2 μm and t = 8 μm, the light and shade pattern on the film surface is distributed at an average of 1.2 μm, and the average in the film thickness direction is 8 μm in a direction according to the inclination angle.
m will be distributed.

However, these sizes are merely average sizes. Actually, portions having different refractive indices of various sizes large and small with respect to these sizes are distributed on the surface and inclined in the depth direction. The light scattering film of the present invention as shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to specific examples and comparative examples for clarifying the features of the present invention.

Example 1 Bisphenol epoxy resin epicoat 1004 (epoxy equivalent: 875-97)
5, 90% by weight of trade name of Yuka Shell Epoxy Co., Ltd.
2,2-bis {p- (3-butoxy-2-glycidyloxypropyloxy) phenyl} propane (XB412
2, epoxy equivalent: 300-370, manufactured by Asahi Chiba Co., Ltd.)
10 parts by weight, 50 parts by weight of tripropylene glycol diacrylate (VISCOAT-310HP, trade name of Osaka Organic Chemical Co., Ltd.) and 4,4′-bis (tert-
7.5 parts by weight of butylphenyl) iodonium hexafluorophosphate, 3,3′-carbonylbis (7-
A solution prepared by mixing and dissolving 0.25 parts by weight of (diethylaminocoumarin) in 100 parts by weight of 2-butanone was used as a photosensitive solution. The photosensitive solution is blue plate glass (1.1 mm thick, 5 inch square)
Then, it was coated with a doctor blade so as to have a thickness of about 50 μm and dried to obtain a recording medium.

The recording medium was exposed from the surface of the recording material (α = 22) with the optical system shown in FIG. 6 using a light obtained by spreading an argon laser (488 nm) as a light source using a lens through a ground glass 15. #, After 40mJ / cm ² ), 80
C. for 1 minute, and the entire surface of the recording medium was irradiated with a high-pressure mercury lamp to fix the recording medium. Furthermore, a light-scattering film was obtained by peeling the cured product from the glass substrate. The thickness of the obtained film was 68 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate.

For evaluation, transmittance (wavelength range: 400 to 600 nm) was measured at each angle using a spectrophotometer manufactured by Shimadzu Corporation. Table 1 shows the results (average transmittance of all wavelengths).

[0066]

[Table 1]

Example 2 Bisphenol epoxy resin epicoat 1004 (epoxy equivalent: 875-97)
5, hydrogenated bisphenol-based epoxy resin suntote 5100 instead of Yuka Shell Epoxy Co., Ltd.)
(Epoxy equivalent: 900-1100, trade name, manufactured by Toto Kasei Co., Ltd.) was used in the same manner as in Example 1 to obtain a produced light-scattering film. The thickness of the obtained film was 67 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate. Table 2 shows the results.

[0068]

[Table 2]

Example 3 2,2-bis {p- (3-butoxy-2-glycidyloxypropyloxy) phenyl} propane (XB4122, epoxy equivalent: 300-)
370, manufactured by Asahi Chiba Co., Ltd. instead of a flexible epoxy resin epicoat 871 (epoxy equivalent: 390-470;
The same operation as in Example 1 was performed except that Yuka Shell Epoxy (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) was used to obtain a produced light-scattering film. The thickness of the obtained film was 70 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate. Table 3 shows the results.

[0070]

[Table 3]

<Example 4> Instead of 3,3'-carbonylbis (7-diethylaminocoumarin), 2-N,
Instead of N-dimethylaminobenzylidene) -p-methoxyacetophenone, an argon laser (488) was used as a light source.
nm) was replaced with a krypton laser (413 nm) to operate in the same manner as in Example 1 to obtain a light-scattering film. The thickness of the obtained film is 6
It was 8 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate. Table 4 shows the results.

[0072]

[Table 4]

Example 5 Instead of tripropylene glycol diacrylate (VISCOAT-310HP, trade name of Osaka Organic Chemical Co., Ltd.), neopentyl glycol diacrylate (VISCOAT-215, trade name of Osaka Organic Chemical Co., Ltd.) was used. ) Was carried out in the same manner as in Example 1 except that (1) was used to obtain a produced light-scattering film. The thickness of the obtained film was 73 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate. Table 5 shows the results.

[0074]

[Table 5]

Example 6 Bisphenol epoxy resin epicoat 1004 (epoxy equivalent: 875-97)
5. Same as Example 1 except that bisphenol-based epoxy resin Epicoat 1007 (epoxy equivalent: 1750-2200, trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) is used instead of Yuka Shell Epoxy Co., Ltd. To obtain a produced light-scattering film. The thickness of the obtained film was 82 μm. The resulting film has flexibility, even after peeling from the glass substrate,
No cracks, cracks, etc. occurred. Table 6 shows the results.

[0076]

[Table 6]

Example 7 Bisphenol-based epoxy resin (Epicoat 1004, epoxy equivalent: 875-97)
5, 60 parts by weight of bisphenol-based epoxy resin (Epicoat 1004, epoxy equivalent: 875-975, trade name of Yuka Shell Epoxy Co.) and bromination instead of 100 parts by weight of Yuka Shell Epoxy Co., Ltd. A light-scattering film was obtained in the same manner as in Example 1, except that 40 parts of a bisphenol-based epoxy resin (Araldite 8049SP, epoxy equivalent: 450-490, trade name of Ciba-Geigy Corporation) was used. . The thickness of the obtained film was 83 μm. The obtained film had flexibility, and did not break or crack even after peeling from the glass substrate. Table 7 shows the results.

[0078]

[Table 7]

Comparative Example 2,2-bis {p- (3-butoxy-2-glycidyloxypropyloxy) phenyl} propane (XB4122, epoxy equivalent: 300-)
370, manufactured by Asahi Chiba Co., Ltd., without using bisphenol-based epoxy resin Epicoat 1004 (epoxy equivalent: 87
5-975, trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 90
A light-scattering film was produced in the same manner as in Example 1 except that the weight part was changed to 100 parts by weight. The scattering property was the same as that of Example 1, but the material peeled off from the glass substrate was broken when bent. The thickness of the fragments of the obtained film was 81 μm.

[0080]

According to the present invention, light scattering occurs for light incident at a predetermined angle, and conversely, it functions as a transparent film for light perpendicular to the light, thereby reducing light scattering. It has an incident angle selectivity, so that light that needs scattering and light that does not need scattering can be separated by the angle of incidence on the film, and as a result, it is unnecessary when used for display devices etc. It is possible to produce a light-scattering film having the effects of improving the brightness, fineness, and contrast of the display without causing significant scattering, and reducing the blur of the display image, and the like.

Further, when light is incident at an incident angle at which light scattering occurs, a film having scattering anisotropy such that the spread of the scattered light differs vertically and horizontally can be produced.
Therefore, scattered light can be emitted only in a necessary direction. As a result, when used in a display device or the like, there is an effect of improving display brightness and contrast without generating unnecessary scattering.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a light scattering film of the present invention,
The left is a plan view and the right is a cross-sectional view.

FIG. 2 is an explanatory view showing a light scattering film of the present invention;
The left is a plan view and the right is a cross-sectional view.

FIG. 3 is a graph showing an example of the incident angle dependency of the light scattering film of the present invention.

FIG. 4 is a diagram illustrating anisotropy of light scattering possessed by the light scattering film of the present invention.

FIG. 5 is an explanatory view showing an example of an optical system for producing a light scattering film having the structure shown in FIG. 1 using a mask pattern.

FIG. 6 is an explanatory view showing an example of an optical system for producing a light scattering film having the structure shown in FIG. 2 using a speckle pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light scattering film 2 ... Illumination light incident from a scattering direction 3 ... Illumination light incident from a transmission direction 4 ... Plot of measured haze value 5 ... Photosensitive material 6 ... UV light source 7 ... Collimate optical system 8 ... Parallel light 9 ... Mask original plate 10 ... Glass substrate 11 ... Chromium pattern 12 ... Optical fiber 13 ... Laser light source 14 ... Laser light 15 ... Frosted glass 16 ... Beam expander 17 ... Collimator

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H042 BA01 BA14 BA15 BA20 4F071 AA42 AC09 AC10 AC12 AE06 AF26 AF30 AF35 AG15 AH12 BA02 BB02 BC01 4J011 QA01 QA02 QA03 QA06 QA13 QA37 SA74 SA78 SA83 SA84 SA86 UA01 VA01 VA02 AB09 AD01 AD08 AG04 DA02 DA05 DB17 DB23 DC45 EA01 EA02 EA04 GA01 GA02 GA03 GA04 GA15 HA02 JA15 KA01

Claims (5)

[Claims] 1. A pattern having different refractive indices distributed in an irregular shape and thickness to form a light and shade pattern having high and low refractive indices. Light scattering film having a structure that is distributed in a layered manner inclining with respect to the inclination direction, light scattering occurs for light incident at an angle along the inclination direction, and is perpendicular to the inclination direction. A composition that constitutes a light-scattering film having an incident-angle selectivity in light-scattering properties that functions as a mere transparent film with respect to natural light has at least one oxirane ring in a plurality of (A) molecules. A compound;
(B) a compound having radical polymerizability, (C) a photoinitiator which generates a cationic species and a radical species by actinic radiation, (A) a compound having at least one oxirane ring in a molecule, and (B) radical polymerization A composition for a flexible light-scattering film, wherein the compounds having a property have a difference in refractive index. 2. A compound represented by the general formula (1): wherein the compound (A) has at least one oxirane ring in the molecule. (In the formula, m + n is 2 or more, and R represents a straight-chain alkyl group having 1 to 5 carbon atoms.) And a general formula (2) (In the formula, m + n is 2 or more, and R represents a linear alkyl group having 1 to 5 carbon atoms.) And a general formula (3) (In the formula, m + n corresponds to 4 to 8, and R represents a straight-chain alkyl group having 1 to 5 carbon atoms (C).)
Alternatively, a composition for a flexible light-scattering film, comprising at least one selected from bisphenol A diglycidyl ether polymerized fatty acid adduct and polymerized fatty acid polyglycidyl ester. 3. The flexible light according to claim 1, wherein a sensitizing dye (D) for sensitizing a photoinitiator (C) that generates a cationic species and a radical species by the actinic radiation is added. Composition for scattering film. 4. The compound having radical polymerizability (B)
Has a refractive index lower than that of the compound (A) having at least one oxirane ring in the molecule, and has at least an ethylenically unsaturated bond which is liquid at normal temperature and normal pressure and has a boiling point of 100 ° C. or higher at normal pressure. The composition for a flexible light-scattering film according to claim 1, which is a compound having at least one compound. 5. A method according to claim 1, wherein the radical polymerizable compound (B) is mixed in an amount of 20 to 80 parts by weight with respect to 100 parts by weight of the compound (A) having at least one oxirane ring in the molecule. The composition for a flexible light-scattering film according to claim 1, wherein