JPH07333583A - Production of light scattering type liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide a light scattering type liquid crystal display element which has good turbidity at the time of scattering, excellent brightness and an extremely high contrast, is capable of extremely diminishing the parts to shield UV rays by active elements or black matrix, etc., when used as an active driving panel and has a light controllable layer of a uniform three-dimensional network structure. CONSTITUTION:This process for producing the light scattering type liquid crystal display element comprises forming the light controllable layer by holding a liquid crystal material, a polymerizable compd. and a polymn. initiator between two sheets of substrates which have electrode layers and at least one of which are transparent, then irradiating the substrates with UV rays. The UV rays transmitted through a layer consisting of a light scattering layer forming material contg. the liquid crystal material, the polymerizable compd. and the polymn. initiator or a light scattering layer contg. the liquid crystal material and transparent solid material are used as the UV rays for polymn. of the process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal device capable of forming a large area.
Transmission can be operated electrically or thermally, and by displaying characters and figures and switching the display electrically with high-speed response, it can be used for advertising boards, guide boards, decorative display boards, etc. The present invention relates to a light-scattering type liquid crystal display element used as a high information display body such as a display body and a display for OA equipment.

[0002]

2. Description of the Related Art In order to enable low voltage driving characteristics, high contrast and time division driving, which are important characteristics required for practical use of liquid crystal devices, JP-A-1-198725 and JP-A-2-85822. The publication discloses a liquid crystal device having a dimming layer in which a liquid crystal material forms a continuous layer, and a three-dimensional network polymer material is formed in the continuous layer.

In such a liquid crystal device, a light control layer forming material containing a liquid crystal material, a photopolymerizable composition and a photopolymerization initiator is interposed between two transparent substrates having electrode layers,
A light control layer comprising a liquid crystal material and a transparent polymer substance as described above is obtained by irradiating light in a state where the light control layer forming material is held in an isotropic liquid state and polymerizing the photopolymerizable composition. It is possible to manufacture a liquid crystal device having the above. Usually, when ultraviolet light is supplied to the light control layer forming material, a method of directly irradiating the light control layer constituent material with ultraviolet light is used.

Further, a method for producing a light-scattering type liquid crystal display device by irradiating ultraviolet rays having a short wavelength ultraviolet ray of 390 nm or shorter cut off by using a filter or the like is disclosed in JP-A-4-18810.
No. 5 is disclosed.

[0005]

The manufacturing method using the above-mentioned filter or the like aims to prevent the photodegradation of the liquid crystal material of the formed light-scattering liquid crystal display element and prevent the resistance and the voltage holding ratio from decreasing. And there was no effect of improving the cloudiness.

Further, in an active driving panel, when an active element, a black matrix or the like is formed on a substrate, the ultraviolet rays are blocked even if they are irradiated with ultraviolet rays, and the polymerization of the polymerizable composition becomes insufficient. Forming a uniform three-dimensional network structure has been a difficult problem.

The problem to be solved by the present invention is to use ultraviolet rays effectively, to form a transparent polymer substance having a uniform three-dimensional network structure in the light control layer, and to provide light having a higher contrast than before. Provided is a method for manufacturing a scattering type liquid crystal display device, and further, a portion where ultraviolet rays are blocked by an active element such as an active driving panel or a black matrix can be made extremely smaller than before, and a uniform three-dimensional mesh shape can be obtained. It is an object of the present invention to provide a method for manufacturing a light-scattering liquid crystal display element that forms a structure.

[0008]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

In order to solve the above-mentioned problems, the present invention provides (I) two substrates having at least one transparent electrode layer, and a liquid crystal material, a polymerizable compound and a polymerization initiator between the two substrates. After sandwiching the light control layer forming material containing, by polymerizing the polymerizable compound by irradiating with ultraviolet rays,
In a method for producing a light-scattering liquid crystal display device that forms a light control layer containing a liquid crystal material and a transparent solid substance, (1) light scattering containing a liquid crystal material, a polymerizable compound and a polymerization initiator as ultraviolet rays for polymerization. Layer made of layer forming material or (2)
A method for producing a light-scattering type liquid crystal display device using ultraviolet light transmitted through a light-scattering layer containing a liquid crystal material and a transparent solid substance,
And (II) after applying a light control layer forming material containing a liquid crystal material, a polymerizable compound and a photopolymerization initiator onto one of the two transparent substrates having at least one having an electrode layer,
A light-scattering liquid crystal in which a polymerizable compound is polymerized by irradiating with ultraviolet rays to form a light control layer containing a liquid crystal material and a transparent solid substance, and then the other substrate is bonded onto the light control layer. In the method for producing a display element, as the ultraviolet ray for polymerization, (1) a layer composed of a light-scattering layer forming material containing a liquid crystal material, a polymerizable compound and a polymerization initiator, or (2)
Provided is a method for manufacturing a light-scattering type liquid crystal display element, which uses ultraviolet rays transmitted through a light-scattering layer containing a liquid crystal material and a transparent solid substance.

FIG. 1 shows an example of a method of manufacturing the light-scattering type liquid crystal display element of the present invention.

In FIG. 1, 1 is an ultraviolet light source, and 2 is a light scattering layer containing (a) a liquid crystal material and a transparent solid substance or (b) light containing a liquid crystal material, a polymerizable compound and a polymerization initiator. A layer made of a scattering layer forming material, 3 is a transparent substrate with an electrode or an active driving substrate, 4 is a light control layer forming material containing a liquid crystal material, a polymerizable compound and a photopolymerization initiator, and 5 Is a sealant.

After the arrangement as described above, ultraviolet rays are irradiated. At this time, the light scattering layer or the layer 2 composed of the light scattering layer forming material containing a liquid crystal material, a polymerizable compound and a polymerization initiator.
May or may not be in close contact with the substrate 3.

Alternatively, a light control layer forming material containing a liquid crystal material, a polymerizable compound and a photopolymerization initiator is applied to one of the two substrates 3 by a well-known coating method such as a bar coating method. After application to a constant film thickness, in a nitrogen atmosphere, irradiate with ultraviolet rays that have passed through the light scattering layer or the layer composed of the light scattering layer forming material arranged as described above to contain the liquid crystal material and the transparent solid substance. After the dimming layer is formed, the other substrate 3 may be attached on the dimming layer, and the peripheral edges of the two substrates may be sealed.

According to the manufacturing method of the present invention, since ultraviolet rays are scattered by the light scattering layer, the ultraviolet irradiation intensity distribution is made uniform, and a uniform three-dimensional network structure is efficiently formed in the light scattering type liquid crystal display device. Can be formed.

The light-scattering layer may be made of a liquid crystal material, an ultraviolet light-scattering layer forming material containing a polymerizable compound and a polymerization initiator, or a liquid crystal material and a transparent solid substance, which scatters ultraviolet light.

Specifically, (1) a liquid crystal material is present in resin and polymer capsules, and the capsules are uniformly applied to a transparent substrate to produce, and (2) polymer and liquid crystal are common to both. Manufactured by dissolving in a good solvent, casting the melt on a transparent substrate, and then evaporating the solvent. (3) A uniform solution of liquid crystal and monomer is present between transparent substrates or on the transparent substrate, Examples include, but are not limited to, those produced by irradiating with and polymerizing a monomer, and (4) those produced by dipping liquid crystal in a three-dimensional network substance such as a resin or a monomer on a substrate. .

The average particle size of the liquid crystal of these light-scattering layers or the average void spacing of the three-dimensional network structure formed from the transparent solid substance is preferably in the range of 0.1 to 5 μm. Further, the layer thickness is preferably in the range of 1 to 500 μm in order to obtain the ultraviolet light scattering property and to obtain a sufficient ultraviolet ray transmission intensity.

The ultraviolet spectral wavelength range of the ultraviolet light for polymerization which has passed through the light scattering layer is preferably in the range of 320 to 400 nm,
The range of 340 to 400 nm is more preferable.

Light in the visible range may or may not exist in the spectral wavelength range of the ultraviolet ray for polymerization which has passed through the light scattering layer.

The ultraviolet rays used as the energy for polymerization are
In the polymerization of a polymerizable compound by ultraviolet irradiation in a liquid crystal material, the light irradiation intensity and the irradiation dose also require a certain intensity or more, which depends on the reactivity of the polymerizable compound and the type and concentration of the polymerization initiator. By selecting an appropriate light intensity, it is possible to form a three-dimensional mesh and make the mesh size uniform. More preferably, irradiating light uniformly in time and plane as a method of irradiating light, a polymerizable compound intervening between the substrates is instantaneously irradiated with strong light to proceed with the polymerization, thereby making the size of the mesh uniform. It is effective in measuring. That is, a uniform three-dimensional network polymer can be realized in one continuous layer of the liquid crystal material by irradiating it in a pulsed manner with an appropriate light intensity.

The substrate used in the present invention may be a rigid material such as glass or metal, or a flexible material such as a plastic film. The two substrates are opposed to each other and are separated by an appropriate distance. In addition, the substrate must be transparent so that the light control layer sandwiched between the two substrates can be seen from the outside world. However, complete transparency is not essential.

Depending on the purpose, transparent electrodes may be disposed on the entire surface or a part of the substrate. However, in the case of a flexible material such as a plastic film, it can be used in the production method of the present invention after being fixed to a rigid material such as glass or metal.

In order to control the thickness of the transparent solid substance that is uniformly adhered to the substrates, it is desirable to interpose a spacer between the two substrates for maintaining a distance, as in a commonly known liquid crystal device.

A spacer may be mixed with a solution of a liquid crystal material and a monomer or an oligomer, or a solution of an organic solvent and a monomer or an oligomer, or a spacer may be coated on one of the substrates.

As the spacer, for example, Mylar,
Alumina, rod-type glass fiber, glass beads, polymer beads, and other various liquid crystal cells can be used.

The liquid crystal material used in the present invention does not need to be a single liquid crystal compound, and may be a mixture containing two or more kinds of liquid crystal compounds or substances other than the liquid crystal compounds. Any material that is generally recognized as a liquid crystal material in this technical field is preferable, and one having a positive dielectric anisotropy is preferable, and if the manufactured liquid crystal device is a liquid crystal that can obtain good characteristics. good.

The liquid crystal used is preferably a nematic liquid crystal, a smectic liquid crystal or a cholesteric liquid crystal, particularly preferably a nematic liquid crystal. In order to improve its performance, cholesteric liquid crystals, chiral nematic liquid crystals, chiral smectic liquid crystals, chiral compounds and 2
A color dye or the like may be appropriately contained.

The liquid crystal material used in the present invention is preferably a compounded composition comprising one or more compounds selected from the compound group shown below, and the characteristics of the liquid crystal material, that is, the phase of the isotropic liquid and the liquid crystal. For the purpose of improving the transition temperature, melting point, viscosity, Δn, Δε, solubility with a polymerizable composition and the like, they can be appropriately selected and blended for use.

Examples of the liquid crystal material include 4-substituted benzoic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy)
Benzoic acid 4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4'-substituted cyclohexyl ester, 4-substituted 4'-substituted Biphenyl, 4-substituted phenyl-4'-substituted cyclohexane,
4-substituted 4 ″ -substituted terphenyl, 4-substituted biphenyl 4′-substituted cyclohexane, 2- (4-substituted phenyl)
-5-substituted pyrimidine etc. can be mentioned.

The proportion of the liquid crystal material in the light control layer is 60% by weight.
The above is preferable, and the range of 70 to 90% by weight is particularly preferable. (Hereinafter, "%" means "% by weight")

The polymerizable compound used for the light control layer forming material is
These are polymer-forming monomers and oligomers, and two or more kinds of these monomers and oligomers can be used in combination.

As the polymer-forming monomer, for example,
Styrene, chlorostyrene, α-methylstyrene, divinylbenzene; as a substituent, methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl,
Nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl,
Acrylate, methacrylate or fumarate having a group such as 3-chloro-2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexa Poly (meth) acrylates or poly (meth) acrylates such as methylene glycol, neopentyl glycol, trimethylolpropane, glycerin and pentaerythritol;
Vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, 2-, 3- or 4-vinyl pyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethyl acrylamide or N-hydroxyethyl methacrylamide and alkyl ether compounds thereof; di- or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; to 1 mol of neopentyl glycol Di (meth) diol obtained by adding 2 moles or more of ethylene oxide or propylene oxide
Acrylate; Reaction product of 1 mol of 2-hydroxyethyl (meth) acrylate and 1 mol of phenyl isocyanate or n-butyl isocyanate; Poly (meth) acrylate of dipentaerythritol; Poly (tris- (hydroxyethyl) -isocyanuric acid poly ( (Meth) acrylate; poly (meth) acrylate of tris- (hydroxyethyl) -phosphoric acid; di- (hydroxyethyl)-
Dicyclopentadiene mono (meth) acrylate or di (meth) acrylate; pivalate neopentyl glycol diacrylate; caprolactone modified hydroxypivalate neopentyl glycol diacrylate; linear aliphatic diacrylate; polyolefin modified neopentyl glycol di An acrylate etc. can be mentioned.

As the polymer-forming oligomer, various acrylate oligomers such as epoxy (meth) acrylate, polyester (meth) acrylate, polyurethane (meth) acrylate and polyether (meth) acrylate can be used.

The transparent solid substance having this three-dimensional network structure is not limited to a solid substance, but is flexible as long as it can be used according to the purpose.
It may have elasticity.

Examples of the polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1-hydroxycyclohexyl phenyl ketone (“Ciba Geigy”). Irgacure 184 "), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
On (Merck "Darocur 1116"), benzyl dimethyl ketal (Ciba Geigy "Irgacure 651"), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Ciba)・ Geigy's "Irgacure 907"), 2,4-diethylthioxanthone (Nippon Kayaku's "Kayacure DET"
X)) and ethyl p-dimethylaminobenzoate (“Kayacure EPA” manufactured by Nippon Kayaku Co., Ltd.), isopropyl thioxanthone (“Cantcure ITX” manufactured by Ward Prekinsop) and ethyl p-dimethylaminobenzoate. And a mixture thereof.

The proportion of the polymerization initiator used is preferably 0.1 to 10.0% of the total amount of the polymerizable compounds.

The average spacing of the meshes of the three-dimensional mesh structure formed of the transparent solid substance is preferably in the range of 0.2 to 5 μm. In addition, the layer thickness of the layer having a transparent solid substance is set to 1 to obtain a sufficient contrast between the opacity due to light scattering and the transparency achieved electrically or thermally depending on the purpose of use. The range of 30 μm is preferable.

[0038]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples. However, the invention is not limited to these examples. In the following Examples and Comparative Examples, "%" represents "% by weight", and each of the evaluation characteristics means the following symbols and contents.

Further, the intensity of ultraviolet rays is as follows: Unimeter "UIT-101" manufactured by Ushio Inc. and light receiving element "UVD-3".
65 PD].

T ₀ : White turbidity; Light transmittance (%) when applied voltage is 0. T ₁₀₀ : Transparency; Light transmittance (%) when the applied voltage is increased and the light transmittance hardly increases. CR: Contrast = T ₁₀₀ / T ₀

(Example 1) "PN001" (nematic liquid crystal material manufactured by Roddick) 80.0% and "KAYARAD-HX-620" (caprolactone modified hydroxypivalate neopentyl glycol diester manufactured by Nippon Kayaku Co., Ltd.) Acrylate) 19.6% and "Darocur 1173" (Merck Co. photopolymerization initiator; 2-hydroxy-2-methyl-1-phenylpropan-1-one)
A light-scattering layer forming material consisting of 0.4% is sandwiched between two transparent substrates coated with 11.0 micron glass fiber spacers, and while maintaining the whole substrate at 42 ° C., an ultraviolet ray of 45 mW / cm ² Was irradiated for 60 seconds to produce a light-scattering layer for transmitting ultraviolet light.

When the transparent solid substance of the light transmitting layer for transmitting ultraviolet light thus obtained was observed with an electron microscope (SEM), it was possible to confirm a network structure with an average gap of 1.2 μm.

Next, "PN001" 80.0%, lauryl acrylate 3.92%, "KAYARAD"
-HX-620 "15.68% and" Darocur 11
73 "0.4% of the light control layer forming material was coated with a 11.0 micron glass fiber spacer 2
It is sandwiched between glass substrates having ITO electrodes and placed behind the light-scattering layer for ultraviolet ray transmission while keeping the entire substrate at 36 ° C., and then 45 mW from the light-scattering layer side for ultraviolet ray transmission.
The polymerizable compound was cured by irradiating with ultraviolet rays of / cm ² for 60 seconds to obtain a light scattering type liquid crystal display device.

When the light control layer of the light-scattering type liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

As a result of measuring the light transmittance of this light-scattering type liquid crystal display device at the time of light scattering and at the time of transmitting light, T ₀ = 1.8%, T ₁₀₀
= 86.7%, CR = 48.2.

[0046] (liquid crystal material property of "PN001") transition temperature 68.5 ℃ (N-I) < -25 ℃ (C-N) refractive index _{n e = 1.787 n o = 1.583} Δn = 0. 254 Threshold voltage (Vth) 1.15V Viscosity at 20 ° C. 59c. p. Dielectric anisotropy Δε = 26.9

(Example 2) "PN001" (manufactured by Rodick) 80.0%, lauryl acrylate 3.92%,
"KAYARAD-HX-620" 15.68
% And “Darocur 1173” 0.4% were sandwiched between glass substrates having two ITO electrodes coated with 11.0 micron glass fiber spacers.

On this substrate, "PN001" 80.0
%, Lauryl acrylate 3.92%, “KAYARAD-HX-620” 15.68% and “Darocur 1173” 0.4%, and a layer for forming a light-scattering layer for UV transmission using a bar coater. After coating to a thickness of 50 μm, while maintaining the entire substrate at 36 ° C,
It was made to exist in nitrogen and irradiated with 45 mW / cm ² of ultraviolet rays for 60 seconds from the side of the ultraviolet-transmissive light-scattering layer forming material. The light-scattering layer for transmitting ultraviolet rays formed on the substrate was removed by using acetone to obtain a light-scattering type liquid crystal display element.

The transparent solid substance of the light-scattering layer for transmitting ultraviolet light formed on the substrate was observed with an electron microscope (SEM) before the removal with acetone, and the average gap was 1.8 μm. It was possible to confirm the mesh structure of.

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

As a result of measuring the transmittance of this light-scattering liquid crystal display device at the time of light scattering and at the time of transmission, T ₀ = 2.0%, T ₁₀₀
= 86.7%, CR = 43.4.

(Embodiment 3) "PN001" 34%, "P001"
VA-405 "(Kuraray polyvinyl alcohol)
A solution obtained by stirring 13.2% and 52.8% of water with a homogenizer for 3 minutes was applied onto a transparent substrate using a bar coater, and then naturally dried for 50 hours to obtain a light for transmitting ultraviolet light. A scattering layer was obtained.

When the transparent solid substance of the light transmitting layer for transmitting ultraviolet light thus obtained was observed with an electron microscope (SEM), a spherical structure having an average particle diameter of 4.8 μm could be confirmed.

Next, "PN001" 80.0%, lauryl acrylate 3.92%, "KAYARAD"
-HX-620 "15.68% and" Darocur 11
73 "0.4% of the light control layer forming material was coated with a 11.0 micron glass fiber spacer 2
After sandwiching it between glass substrates having ITO electrodes, keeping the whole substrate at 36 ° C. and arranging it behind the light-scattering layer for transmitting ultraviolet rays, 45 mW / cm ² from the side of the light-scattering layer for transmitting ultraviolet rays
Was irradiated for 60 seconds to polymerize the polymerizable compound to obtain a light-scattering liquid crystal display device.

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

The light transmittance of this light-scattering type liquid crystal display device was measured at the time of light scattering and at the time of light transmission. As a result, T ₀ = 2.0%, T ₁₀₀
= 87.0%, CR = 43.5.

(Example 4) 70% of "PN001" and 30% of "Delpet N60" (polymethylmethacrylate manufactured by Asahi Kasei Corporation) were dissolved in chloroform and then applied on a transparent substrate using a bar coater. It was naturally dried for 50 hours to obtain a light-scattering layer for transmitting ultraviolet light.

When the transparent solid substance of the light transmitting layer for ultraviolet ray transmission thus obtained was observed with an electron microscope (SEM), a spherical structure having an average particle size of 8.6 μm could be confirmed.

Next, "PN001" 80.0%, lauryl acrylate 3.92%, "KAYARAD"
-HX-620 "15.68% and" Darocur 11
73 "0.4% of the light control layer forming material was coated with a 11.0 micron glass fiber spacer 2
It is sandwiched between glass substrates having ITO electrodes and placed behind the light-scattering layer for ultraviolet ray transmission while keeping the entire substrate at 36 ° C., and then 45 mW from the light-scattering layer side for ultraviolet ray transmission.
The light-scattering liquid crystal display device was obtained by irradiating with ultraviolet rays of / cm ² for 60 seconds to cure the polymerizable compound.

When the light control layer of the light-scattering type liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

The transmittance of this light-scattering type liquid crystal display device at the time of light scattering and at the time of passing light was measured. As a result, T ₀ = 2.1%, T ₁₀₀
= 87.2%, CR = 41.5.

(Comparative Example 1) "PN001" 80.0%,
3.92% lauryl acrylate, "KAYA Rad
RAD) -HX-620 ”15.68% and“ Darocur 1173 ”0.4%, and
Sandwiched between two glass substrates with ITO electrodes coated with 0 micron glass fiber spacers,
While maintaining the whole substrate at 36 ° C., 45 mW / cm ² of ultraviolet light was irradiated for 60 seconds to cure the polymerizable compound and obtain a light-scattering liquid crystal display device.

When the light control layer of the light-scattering type liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

The transmittance of this light-scattering type liquid crystal display device was measured at the time of light scattering and at the time of transmission. As a result, T ₀ = 3.8%, T 10
0 = 87.0% and CR = 22.9.

(Example 5) "PN001" 80.0%,
"KAYARAD-HX-620" 19.6%
And a light-scattering layer forming material consisting of 0.4% of "Darocur 1173" are sandwiched between two transparent substrates coated with 11.0 micron glass fiber spacers, and the whole substrate is kept at 42 ° C. , 45 mW / cm ² of ultraviolet ray was irradiated for 60 seconds to cure the polymerizable compound to obtain an ultraviolet-transmitting light scattering layer.

The transparent solid substance of the light-scattering layer for ultraviolet ray transmission thus obtained was observed with an electron microscope (SEM), and a network structure with an average gap of 1.2 μm could be confirmed.

Next, the ITO connected to the active element of the thin film transistor (TFT) made of Cd-Se semiconductor
It is composed of a substrate with pixel electrodes and a black matrix, and "DSA-00
1 "(Rodick's sealant) was applied, and then" Micropearl SP210 "(Sekisui Fine Chemical Co., Ltd. polymer beads with a particle size of 10 microns) was sprayed on the common electrode side to form a transparent substrate having a common substrate composed of ITO electrodes. By laminating and firing and curing, an empty cell having a size of 10 cm × 10 cm and a cell thickness of 10.2 μm to be an active driving panel was prepared.

"PN001" 80.0%, lauryl acrylate 3.92%, "KAYARAD-HX"
-620 "15.68% and as a polymerization initiator" Darocur 1173 "0.4% of a light control layer forming material consisting of 0.4%
While maintaining the temperature at 0 ° C., it was injected into the above empty cell by a vacuum injection method.

Then, while maintaining the whole substrate at 36 ° C.,
After being placed behind the light-transmitting light-scattering layer for ultraviolet ray transmission, 45 mW / cm ² of ultraviolet ray was irradiated from the side of the light-scattering layer for ultraviolet ray transmission for 60 seconds to cure the polymerizable compound to obtain a light-scattering liquid crystal display device. .

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

The transmittance of this light-scattering type liquid crystal display device at the time of light scattering and at the time of passing light was measured. As a result, T ₀ = 1.2%, T ₁₀₀
= 53.8% and CR = 44.8.

(Comparative Example 2) "PN001" 80.0%,
3.92% lauryl acrylate, "KAYA Rad
RAD) -HX-620 ”15.68% and“ Darocur 1173 ”0.4% while maintaining the light control layer forming material at 50 ° C., which is the active driving panel manufactured in Example 5 and is 10 cm × 10 cm square. Then, it was injected into an empty cell having a cell thickness of 10.2 μm by using a vacuum injection method. Then, while keeping the temperature of the entire substrate at 36 ° C., an ultraviolet ray of 45 mW / cm ² was applied to
It was irradiated for 0 seconds to cure the polymerizable compound and obtain a light scattering type liquid crystal display device.

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

As a result of measuring the transmittance of this light-scattering type liquid crystal display device at the time of light scattering and at the time of transmission, T ₀ = 2.4%, T ₁₀₀
= 54.8%, CR = 22.8.

(Example 6) The material for forming the light control layer used in Example 1 was applied to a glass substrate having an ITO electrode so as to have a thickness of 1
After coating so as to have a thickness of 1 micron, while maintaining the whole substrate at 36 ° C. so that the light control layer forming material is in an isotropic liquid state, in a nitrogen atmosphere, light scattering for ultraviolet ray transmission used in Example 1 The polymerizable compound was cured by irradiating the layer with an ultraviolet ray of 45 mW / cm ² for 60 seconds to form a light control layer. After spraying 11.0 micron glass fiber spacers on the dimming layer, another IT on the dimming layer.
A glass substrate having an O electrode was attached to obtain a light-scattering type liquid crystal display device having a light control layer with a thickness of 11.3 μm.

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

The transmittance of this light-scattering type liquid crystal display device at the time of light scattering and at the time of transmitting was measured, and as a result, T ₀ = 3.6%, T ₁₀₀
= 87.0%, CR = 41.4.

Comparative Example 3 The light control layer forming material used in Example 1 was applied to a glass substrate having an ITO electrode at a coating thickness of 1
After coating so as to have a thickness of 1 micron, while maintaining the entire substrate at 36 ° C. so that the light control layer forming material is in an isotropic liquid state, in a nitrogen atmosphere, an ultraviolet ray of 45 mW / cm ² is applied at 60 μm.
The polymerizable compound was cured by irradiation for 2 seconds to form a light control layer. After spraying 11.0 micron glass fiber spacers on the light control layer, another I
A glass substrate having a TO electrode was attached to obtain a light-scattering liquid crystal display device having a light control layer with a thickness of 11.3 microns.

When the light control layer of the light-scattering liquid crystal display device thus obtained was observed with an electron microscope (SEM), a three-dimensional mesh-like transparent solid substance could be confirmed.

As a result of measuring the transmittance of this light-scattering liquid crystal display device at the time of light scattering and at the time of transmission, T ₀ = 3.6%, T ₁₀₀
= 86.4%, CR = 24.0.

The results of measuring the light transmittance and light transmittance of the light-scattering type liquid crystal display elements obtained in each of the examples and each of the comparative examples are summarized in Table 1 below.

[0082]

[Table 1]

From the results shown in the above table, the light-scattering type liquid crystal display elements obtained in the respective examples have higher white turbidity and excellent contrast as compared with the light-scattering type liquid crystal display elements obtained in the comparative example. Understand that

[0084]

The light-scattering type liquid crystal display device obtained by the manufacturing method of the present invention is of a large area and of a thin film type, has good white turbidity when scattered, excellent brightness, and very high contrast. high. Further, in the case of an active driving panel or the like, the part where the ultraviolet rays are blocked by the active element or the black matrix can be made much smaller than before, and a uniform three-dimensional mesh structure can be formed.

Due to these characteristics, it is possible to provide a light-scattering type liquid crystal display device having a higher contrast than ever before.

[Brief description of drawings]

FIG. 1 is an arrangement of an ultraviolet light source, a layer composed of a light-scattering layer or a material for forming a light-scattering layer, a light-modulating layer-forming material and a sealant sandwiched between substrates in a method for manufacturing a light-scattering liquid crystal display device of the present invention. It is a schematic diagram which shows a relationship.

[Explanation of symbols]

 1 Ultraviolet Light Source 2 Light Scattering Layer or Layer Made of Light Scattering Layer Forming Material 3 Transparent Substrate with Electrode or Active Driving Substrate 4 Light Control Layer Forming Material 5 Sealant

Claims (6)

[Claims] 1. At least one transparent substrate having an electrode layer, and a light control layer forming material containing a liquid crystal material, a polymerizable compound and a photopolymerization initiator between the two substrates, In the method for producing a light-scattering liquid crystal display element, which comprises polymerizing a polymerizable compound by irradiating ultraviolet rays to form a light control layer containing a liquid crystal material and a transparent solid substance, (1) liquid crystal is used as ultraviolet rays for polymerization. Light scattering characterized by using ultraviolet light transmitted through a layer composed of a material for forming a light scattering layer containing a material, a polymerizable compound and a polymerization initiator or (2) a light scattering layer containing a liquid crystal material and a transparent solid substance. Type liquid crystal display element manufacturing method. 2. A dimming layer forming material containing a liquid crystal material, a polymerizable compound and a photopolymerization initiator is applied on one of two transparent substrates having at least one having an electrode layer, and then ultraviolet light is applied. The light-scattering liquid crystal display in which the polymerizable compound is polymerized by irradiating to form a dimming layer containing a liquid crystal material and a transparent solid substance, and then the other substrate is bonded onto the dimming layer. In the method for manufacturing an element, as the ultraviolet ray for polymerization, (1) a layer composed of a light-scattering layer forming material containing a liquid crystal material, a polymerizable compound and a polymerization initiator, or (2) light containing a liquid crystal material and a transparent solid substance. A method for manufacturing a light-scattering type liquid crystal display device, characterized in that ultraviolet rays transmitted through a scattering layer are used. 3. The method for producing a light-scattering liquid crystal display element according to claim 1, wherein the ultraviolet spectral wavelength range of the ultraviolet light for polymerization which has passed through the light-scattering layer is in the range of 320 to 400 nm. 4. The light-scattering layer through which the ultraviolet ray for polymerization is transmitted comprises a three-dimensional mesh-like transparent solid substance formed in a continuous layer of a liquid crystal material. A method for manufacturing a light-scattering type liquid crystal display device. 5. The method for producing a light-scattering liquid crystal display device according to claim 4, wherein the average void spacing of the three-dimensional network structure of the light-scattering layer is in the range of 0.1 to 5 μm. 6. The light control layer formed between the substrates comprises a continuous layer of a liquid crystal material and a three-dimensional mesh-like transparent solid substance. A method for manufacturing a light-scattering type liquid crystal display device.