JPH09244032A - Adhesive spacer for liquid crystal display panel, its production and liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an adhesive spacer for a liquid crystal display having not only excellent adhesion property with a substrate but excellent wet spraying property by constituting the spacer of adhesive particles each comprising the particle body and an adhesive layer coating the particle surface, and fine particles deposited on the adhesive layer. SOLUTION: This adhesive spacer 8 contains an adhesive particles and fine particles. The adhesive particle consists of a particle body and an adhesive layer covering the particle surface. The fine particles are deposited on the adhesive layer. Upper and lower electrode substrates 120, 110 are laminated with the adhesive spacer 8 in such a manner that an electrode 5 and an orienting film 4 faces each other, and the laminated substrates are heated at 150 deg.C for 30min under 1kg/cm<2> pressure to heat and harden an adhesive sealing material 2. Then the space between the two electrode substrates 120, 110 is evacuated and then returned to atmospheric pressure. An STN liquid crystal 7 is injected into the space and the injection port is sealed. Then PVA polarizing films 6 are adhered to the outside of the upper and lower glass substrates 12, 11.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive spacer for a liquid crystal display panel, a method for manufacturing the same, and a liquid crystal display panel.

[0002]

2. Description of the Related Art A liquid crystal display (LCD) generally comprises two opposing electrode substrates, a spacer interposed between the electrode substrates, and a liquid crystal material. The spacer is used for the purpose of keeping the thickness of the liquid crystal layer uniform and constant. In recent years, liquid crystal display boards have been used for in-vehicle applications such as portable information terminals such as mobile phones and pagers, mobile communication, car navigation, and the like, taking advantage of their characteristics of being lightweight and thin.

However, in these applications, compared to applications such as desktop type personal computers, word processors, and TVs, the spacers are more likely to move and fall off due to the load of vibration and shock accompanying movement, and the thickness of the liquid crystal layer. There is a problem in that it cannot be held uniformly and constantly. In recent years, in the above personal computers and the like, the screen has been remarkably increased in size, and when the screen is remarkably increased in size, the electrode substrate is likely to bend, resulting in the movement of the spacer and the thickness of the liquid crystal layer. There is also a problem that it becomes impossible to maintain the temperature uniformly and uniformly.

For the purpose of preventing the spacers from moving and falling off as described above, adhesive spacers having spacer particles coated with an adhesive have been developed. As such an adhesive spacer, for example, resin fine powder having a heat deformation temperature in the range of 25 to 180 ° C. is adsorbed by electrostatic force on the surface of cured spherical fine particles of amino resin,
An adhesive spacer in which resin fine powder is immobilized on the surface of the hardened spherical fine particles by a method of impacting the hardened spherical fine particles after being dispersed in an air current flowing at high speed (impact method in high speed airflow) (JP-A-1 No. 150428)); spherical particles such as divinylbenzene crosslinked particles and silicate glass are dispersed in a hot melt type resin or epoxy resin solution, and then the temperature of the dispersion is gradually lowered, or An adhesive spacer in which the above resin is deposited on the surface of spherical fine particles by a method of dropping a poor solvent for these resins (coacervation method) (JP-A 1-2).
47154, JP-A-2-261537, JP-A-4-261.
No. 36723, JP-A-4-36724, etc.); An adhesive spacer in which an adhesive layer is provided on the particle surface by grafting a polymer chain having an adhesive property on the surface of spherical fine particles (JP-A-7-300586). JP-A-7-30058
No. 7, Japanese Patent Laid-Open No. 7-333623, etc.) are known. In any of these adhesive spacers, the surface of the spherical fine particles is covered with an adhesive layer containing an adhesive resin.

After the above-mentioned adhesive spacers are dispersed on the substrate, they are adhered and fixed on the substrate only by heating or by heating and pressing. This prevents the spacer from moving or falling off. on the other hand,
Wet or dry spraying is conventionally known as a method for spraying the spacers, but wet spraying is often used because the spacers are less likely to aggregate and can be sprayed uniformly.
Wet spraying is a method in which spacers are monodispersed in a solvent such as alcohol, and the resulting dispersion is sprayed and the solvent is volatilized and removed. However, when the adhesive spacer is wet-sprayed, the resin contained in the adhesive layer of the adhesive spacer swells in the solvent to agglomerate the spacers, or the adhesive layer is dissolved and the adhesive layer disappears. Even if it is sprayed on the substrate, the spacers are agglomerated severely, the spacers are not fixed on the substrate, the dissolved adhesive layer is deposited on the substrate and scratches or covers the substrate, the alignment film and the color filter. It is very difficult to wet-spread the adhesive spacer because it has a bad effect such as squeezing.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is not only to provide excellent adhesiveness to a substrate, but also to obtain a wet spraying method that does not cause agglomeration or unevenness of spraying when wet-spreading on a substrate and can be uniformly sprayed. An object of the present invention is to provide an adhesive spacer for a liquid crystal display panel, which has excellent properties, and a liquid crystal display panel including the spacer.

Another object of the present invention is to provide a liquid crystal display which is not only excellent in adhesiveness to a substrate, but also has excellent wet-spreading property such that when sprayed on a substrate by wet spraying, there is little aggregation or unevenness in spraying and uniform spraying is possible. The purpose is to easily and efficiently manufacture an adhesive spacer for a plate.

[0008]

An adhesive spacer for a liquid crystal display panel according to the present invention comprises an adhesive particle having a particle body and an adhesive layer covering the surface thereof, and fine particles attached to the adhesive layer. Including.

The liquid crystal display panel according to the present invention has two facing panels.
It is provided with a sheet of electrode substrates, the above-mentioned adhesive spacer according to the present invention which is interposed between the electrode substrates and holds a space between the electrode substrates, and a liquid crystal sealed between the electrode substrates.

The method for producing an adhesive spacer for a liquid crystal display panel according to the present invention comprises a step of coating the surface of a particle body with an adhesive layer to obtain adhesive particles, and 0.001 of the adhesive particles. An attaching step of preparing fine particles of 10% by weight and attaching the fine particles to the surface of the adhesive layer.

Another method for producing an adhesive spacer for a liquid crystal display panel according to the present invention includes the step of coating the surface of the particle body with a mixture containing a thermoplastic resin and fine particles, and blending the thermoplastic resin and the fine particles. The ratio is the particle body 1
The thermoplastic resin is 0.1 to 50 parts by weight and the fine particles are 0.01 to 20 parts by weight with respect to 00 parts by weight.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Adhesive Spacer for Liquid Crystal Display Plate First, the adhesive spacer for liquid crystal display plate of the present invention will be described. The adhesive spacer for a liquid crystal display panel contains adhesive particles and fine particles. The adhesive particles have a particle body and an adhesive layer covering the surface thereof. The fine particles are attached to the adhesive layer. [Adhesive Particle] The adhesive particle contained in the adhesive spacer of the present invention has a particle main body and an adhesive layer covering the surface thereof. The adhesive layer covers a part or the whole of the surface of the particle body, and may be any. Further, a part or the whole of the adhesive layer may be chemically bonded to the particle main body surface.

The particle body of the adhesive particles is necessary, for example, in order to keep the thickness of the liquid crystal layer uniform and constant when used in a liquid crystal display panel, and the average particle size thereof is preferably 1 to 30 μm. It is more preferably 1 to 20 μm, and most preferably 1 to 15 μm. When the average particle diameter is out of the above range, it may not be used as an adhesive spacer for a liquid crystal display panel.

The coefficient of variation (CV) of the particle size of the particle body of the adhesive particles is preferably 10% or less, more preferably 8%.
% Or less, more preferably 6% or less. If the particle size variation coefficient exceeds 10%, when used in a liquid crystal display panel,
It becomes difficult to keep the thickness of the liquid crystal layer uniform and constant, and image unevenness is likely to occur. The average particle diameter and the coefficient of variation of particle diameter referred to here are defined according to the method described in Examples below.

The particle body of the adhesive particles may be of various types and is not particularly limited, and examples thereof include organic crosslinked polymer particles, inorganic particles, organic-inorganic composite particles and the like. Among these, organic cross-linked polymer particles and organic-inorganic composite particles are preferable because it is easy to prevent damage to the electrode substrate, the alignment film or the color filter, and obtain uniform gaps.

The shape of the particle main body of the adhesive particles may be any particle shape such as spherical, needle-like, plate-like, scale-like, crushed, bales-like, eyebrows-like, and sugar-like sugar-like, and is not particularly limited, but liquid crystal When used as a spacer for a display plate, a spherical shape is preferable in order to make the gap distance uniform and constant. This is because particles that are spherical have a constant or nearly constant particle size in all or almost all directions.

The organic cross-linked polymer particles are not particularly limited, but for example, at least one selected from the group consisting of benzoguanamine, melamine and urea.
Cured particles of an amino resin obtained by a condensation reaction between a kind of amino compound or benzoguanamine and formaldehyde (see JP-A-62-068811); Polymerization of divinylbenzene alone or copolymerization with other vinyl monomers And divinylbenzene cross-linked resin particles (see JP-A-1-144429). Among these, the cured particles of the amino resin and the divinylbenzene crosslinked resin particles are preferable because it is easy to prevent damage to the electrode substrate, the alignment film or the color filter, and obtain uniform gaps.

The inorganic particles are not particularly limited, but examples thereof include spherical fine particles of glass, silica, alumina and the like. The organic-inorganic composite particles include, for example, an organic polymer skeleton and a polysiloxane skeleton having in its molecule an organic silicon in which a silicon atom is chemically bonded directly to at least one carbon atom in the organic polymer skeleton, Particles in which the amount of SiO ₂ constituting the polysiloxane skeleton is 25 wt% or more (Japanese Patent Application No.
-160019 and Japanese Patent Application No. 7-176333), but are not limited thereto.

The particle body of the adhesive particles may be colored by containing at least one selected from the group consisting of dyes and pigments. The color is preferably a color through which light hardly transmits or does not transmit light, because light leakage can be prevented and the contrast of image quality can be improved. As a color that is difficult to transmit or does not transmit, for example,
Examples of the color include black, dark blue, dark blue, purple, blue, dark green, green, brown, and red, and particularly preferred are black, dark blue, and dark blue.

The dye is appropriately selected and used according to the color to be colored, and examples thereof include disperse dyes, acid dyes, basic dyes, reactive dyes, and sulfur dyes classified by the dyeing method. Specific examples of these dyes are from pages 1399 to 1427 of “Chemical Handbook Applied Chemistry, edited by The Chemical Society of Japan” (published by Maruzen Co., Ltd. in 1986), and “Handbook of Nippon Kayaku Dye” (issued by Nippon Kayaku Co., Ltd. in 1973). )It is described in.

The method for dyeing the particle body of the adhesive particles is as follows:
A conventionally known method can be adopted. For example, the above “Chemical Handbook Applied Chemistry, edited by The Chemical Society of Japan” and “Handbook of Chemical Dyes”
It can be performed by the method described in. The pigment is not particularly limited, for example, carbon black, iron black, chrome vermilion, molybdenum red, red iron oxide, yellow lead, chrome green, cobalt green, ultramarine, dark blue and other inorganic pigments; phthalocyanine-based, azo-based, Examples include quinacridone-based organic pigments. The pigment may not be introduced into the particle body of the adhesive particles unless the average particle size of the pigment is 0.4 μm or less. Therefore, it is preferable to use a dye.

In the adhesive particles, at least a part of the surface of the particle body, that is, a part or the whole, is covered with the adhesive layer. Further, a part or the whole of the adhesive layer may be chemically bonded to the particle main body surface. The adhesive layer is not particularly limited, but is preferably a layer containing a thermoplastic resin. The thickness of the adhesive layer is not particularly limited, but is usually 0.
It is in the range of 01 to 2 μm, preferably in the range of 0.05 to 1 μm. If the thickness is less than the above range, the adhesiveness may be reduced, and if the thickness is greater than the above range, the area covering the alignment film, the color filter, etc. becomes large, and the display quality of the liquid crystal display plate is degraded. There is a risk.

The average particle diameter of the adhesive particles is not particularly limited, and this average particle diameter is the particle body to which the thickness of the adhesive layer is added, and preferably exceeds 1 μm 32
μm or less, more preferably more than 1 μm and 22 μm or less,
More preferably, it is more than 1.2 μm and 17 μm or less. The thermoplastic resin contained in the adhesive layer, as long as it acts as an adhesive to the electrode substrate,
Although not particularly limited, specific examples thereof include homopolymers or copolymers of ethylenically unsaturated monomers. The ethylenically unsaturated monomer is not particularly limited, but for example, ethylene, propylene, vinyl chloride, vinyl acetate, styrene, vinyltoluene, α-methylstyrene, (meth) acrylic acid ester (for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate
Acrylate, cyclohexyl (meth) acrylate, etc.) and the like. Among these, (meth) acrylic acid ester and styrene are preferable because of their high adhesiveness.

From the viewpoint of further improving the adhesiveness, the thermoplastic resin is most preferably at least one selected from the group consisting of (meth) acrylic resins and (meth) acrylic-styrene resins. The thermoplastic resin is not limited to the above. For example, polyesters such as polyethylene terephthalate and polybutylene terephthalate; various polyamides; various polycarbonates;
Various epoxy resins and the like can also be used as the thermoplastic resin.

The thermoplastic resins may be used alone or in combination of two or more. The glass transition temperature of the thermoplastic resin is preferably from 40 to 100C, more preferably from 45 to 90C, and still more preferably from 50 to 80C. If the glass transition temperature is lower than 40 ° C, the adhesive particles may cause fusion or the like during storage, or may have poor dispersibility when dispersed on the electrode substrate. On the other hand, when the glass transition temperature exceeds 100 ° C., the thermoplastic resin contained in the adhesive layer is less likely to melt during heating and pressing when assembling the liquid crystal display panel, and therefore the adhesiveness to the electrode substrate becomes insufficient. There are cases.

The melting start temperature of the thermoplastic resin is preferably 50 to 160 ° C, more preferably 60 to 150 ° C, and further preferably 70 to 140 ° C. When the melting start temperature is lower than 50 ° C., the adhesive particles may cause fusion during storage or may have poor dispersibility when sprayed on the electrode substrate. On the other hand, when the melting start temperature exceeds 160 ° C., the thermoplastic resin contained in the adhesive layer is less likely to melt during heating and pressing when assembling the liquid crystal display panel, and therefore the adhesiveness with the electrode substrate becomes insufficient. There are cases.

The thermoplastic resin may be colored by containing at least one selected from the group consisting of dyes and pigments. The color is preferably a color through which light hardly transmits or does not transmit light, because light leakage can be prevented and the contrast of image quality can be improved. Is it difficult for light to penetrate?
Or, as the non-transparent color, for example, black, dark blue,
The colors include navy blue, purple, blue, dark green, green, brown, red, etc.,
Particularly preferred are black, dark blue and navy blue.

The dyes and pigments that can be used for coloring the thermoplastic resin are not particularly limited, and examples thereof include those described above as the dyes and pigments that can be used for coloring the particle bodies of the adhesive particles. The weight ratio of the thermoplastic resin in the adhesive layer to the particle body of the adhesive particles is not particularly limited, but is more than 0, preferably 30% or less,
More preferably 1 to 25%, particularly preferably 2 to 20%
It is. When the weight ratio of the thermoplastic resin exceeds 30%,
When the adhesive layer is increased and melted, the area covering the electrode substrate, the alignment film, and the color filter is increased, which may lead to deterioration in image quality of the liquid crystal display panel. On the other hand, if the weight ratio of the thermoplastic resin is low, the adhesiveness will decrease. [Fine Particles] The fine particles contained in the adhesive spacer of the present invention are attached to at least a part of the surface of the adhesive layer, that is, a part of the adhesive layer or the entire adhesive layer.

In the present invention, the state of the fine particles adhering to the adhesive layer is as follows:
Fine particles are simply stuck without adhering to the surface of the adhesive layer, and most of them are exposed from the surface of the adhesive layer. Part of fine particles are embedded in the adhesive layer and part of the particles are exposed to the surface. The fine particles may be completely immersed in the adhesive layer, and the fine particles may not be exposed on the surface of the adhesive layer. The state of each fine particle attached to the adhesive layer may be any one of the above-mentioned. The state of the fine particles in the entire amount of the adhesive spacer may be any of the above, or may be a mixture of the respective states of the above. Above all, when the state of the fine particles is and / or, not only the adhesion to the substrate is further excellent, but also when wet-spreading on the substrate, there is little aggregation or unevenness in spraying, and it is more excellent in wet spraying property. Therefore, it is more preferable that the state of fine particles is.

The adherence rate of the fine particles adhering to the adhesive layer is not particularly limited, but for example, preferably 0.001 to 10% by weight, more preferably 0.05 to 10% by weight with respect to the particle body of the adhesive particles. 5% by weight, more preferably 0.1
１1% by weight. When the adhesion rate is smaller than the above range, wet sprayability is deteriorated. If the adhesion rate is larger than the above range,
Adhesion to the substrate is reduced.

The average particle diameter of the fine particles is not particularly limited, but is preferably 1.0 μm or less, more preferably 0.5 μm or less, still more preferably 0.1 μm or less, and most preferably 0.04 μm or less. If the average particle size is larger than the above range, the gap accuracy of the liquid crystal display panel is significantly affected, which may cause deterioration in image quality.

The fine particles are not particularly limited, but include, for example, inorganic fine particles, organic crosslinked fine particles, and the like.
Species or two or more species are used. The organic crosslinked fine particles may be immersed in the solvent used during the wet spraying, so that it is preferable to use the inorganic fine particles. The inorganic fine particles are not particularly limited, but for example, S
A metal oxide such as iO ₂ , Al ₂ O ₃ , TiO ₂ , or Fe ₂ O ₃ and / or a metal hydroxide thereof is preferable because the wet dispersibility is improved. Above all, when the metal oxide is at least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ and TiO ₂ , short-circuiting does not occur because the insulating property is large, and the wet dispersibility is better. It is preferable because it improves. As commercial products, for example, (trade name) Aerosil 50/130/200 / 200V / 200CF / 200FAD / 300 / 300CF / 380 available from Nippon Aerosil Co., Ltd.
/ TT600 / OX50 / R972 / R972V / R972CF / R974 / MOX80 / MOX170 / CO
K84 / R812 / RX200 / R202 / RY200 / R805, aluminum oxide C 2, titanium dioxide T805, titanium dioxide P25 and the like can be mentioned.

The inorganic fine particles may be used alone or in combination of two or more. The organic crosslinked fine particles are not particularly limited, and examples thereof include particles obtained by crosslinking polymethyl methacrylate, polystyrene, or the like. The organic crosslinked fine particles may be used alone or in combination of two or more. Method for producing adhesive spacer for liquid crystal display plate Next, a method for producing the adhesive spacer for a liquid crystal display plate of the present invention will be described. The adhesive spacer for a liquid crystal display plate described above can be obtained only by the following production method. is not.

The method for producing the adhesive spacer is, for example, (1) a step of coating the surface of the particle body with an adhesive layer to obtain adhesive particles, and (2) fine particles on the surface of the adhesive layer after coating. And an attaching step of attaching. First, the covering step (1) will be described.

The specific method for coating the surface of the particle body with the adhesive layer is not particularly limited, but, for example, particles to be the particle body of the adhesive particles are dispersed in a solution of a thermoplastic resin, After thoroughly stirring and mixing, the solvent is removed by evaporation, and the obtained lumps are pulverized, or the molten thermoplastic resin is dispersed with the particles to be the particle body of the adhesive particles and kneaded sufficiently. And pulverize the lump after cooling; introducing various functional groups (vinyl group, epoxy group, hydroxyl group, etc.) to the surface of the particle body, polymerizing the monomer from the functional group as a starting point, There is a method of reacting with a polymer and grafting on the particle surface.

In addition to the above method, "surface modification"
(Chemical Review No. 44, pp. 45-52, 1987, edited by The Chemical Society of Japan) and "Powder surface modification and high-performance technology"("Surface"
25, No. 1, pages 1 to 19 and a cover photograph, published in 1987), in situ polymerization method, coacervation method, interfacial polymerization method, liquid curing coating method, liquid drying method, Coating can also be performed by a conventionally known resin coating method such as a high-speed airflow impact method, an air suspension coating method, and a spray drying method. In particular, the impact method in a high-speed airflow is, for example, a particle (particle body) to be the particle body of an adhesive particle.
And a powder of a thermoplastic resin (thermoplastic resin powder) are mixed, and the mixture is dispersed in a gas phase, and mechanical thermal energy mainly composed of impact force is applied to the particles and the thermoplastic resin powder. It is a method of coating the surface of the particles with the thermoplastic resin by giving it to the body, and it is most preferable because it can be easily coated. The average particle size of the thermoplastic resin powder used when performing the high-speed air current impact method is not particularly limited, but is, for example, preferably 2 μm or less, more preferably 1.8 μm or less, and most preferably 1.
μm or less. The blending ratio of the thermoplastic resin powder to the particle body is preferably 0.1 to 30 wt%, more preferably 1 to 25 wt%, and most preferably 2 to 20 wt%.

The apparatus using the high-speed air current impact method is not particularly limited, but for example, a hybridization system manufactured by Nara Machinery Co., Ltd., a mechanofusion system manufactured by Hosokawa Micron Co., Ltd., or Kawasaki Heavy Industries, Ltd. There is a Cryptron system manufactured by the company. The average particle diameter of the particle body used in the coating step is preferably the above-mentioned particle diameter.

Next, the attaching step (2) will be described. The attaching method for attaching the fine particles to the surface of the adhesive layer after the coating step is not particularly limited, but for example, the adhesive particles and the fine particles are mixed with a mixing device such as a ball mill, a raft machine, or a Henschel mixer. Methods and the like. Among the above mixing devices, a ball mill is preferable in that it can perform uniform adhesion. It should be noted that mixing may be performed by a method of giving a strong impact such as the high-speed air current impact method.

The mixing ratio of the adhesive particles and the fine particles is not particularly limited, but for example, the fine particles are preferably 0.001 to 10% by weight, more preferably 0. The amount is 05 to 5% by weight, more preferably 0.1 to 1% by weight. When the proportion of the fine particles is smaller than the above range, wet sprayability is deteriorated. If the proportion of the fine particles is larger than the above range, the adhesiveness to the substrate will deteriorate.

Next, another method for producing an adhesive spacer for a liquid crystal display panel includes the step of coating the surface of the particle body with a mixture containing a thermoplastic resin and fine particles, and the mixing ratio of the thermoplastic resin and the fine particles. Is 0.1 to 50 parts by weight of the thermoplastic resin and 0.01 to 20 parts by weight of the fine particles with respect to 100 parts by weight of the particle body.

In this other manufacturing method, for example, the above-mentioned various methods can be used to manufacture the adhesive spacer for a liquid crystal display panel in one step. Among them, the high-speed air current impact method is preferable because the surface of the particle main body can be coated with the mixture most easily. In the high-speed air flow impact method, the mixing ratio of the thermoplastic resin and the fine particles is 0.1 to 50 parts by weight of the thermoplastic resin with respect to 100 parts by weight of the particle main body.
Parts by weight (preferably 0.1 to 30 parts by weight, more preferably 1 to 25 parts by weight, further preferably 2 to 20 parts by weight), fine particles 0.01 to 20 parts by weight (preferably 0.0).
1 to 15 parts by weight, more preferably 0.05 to 10 parts by weight, still more preferably 0.1 to 5 parts by weight). When the blending ratio of the thermoplastic resin is higher than the above range, the area covering the alignment film and the color filter becomes large, and the display quality of the liquid crystal display plate is deteriorated. If the blending ratio of the thermoplastic resin is less than the above range, the adhesiveness to the substrate will decrease. If the mixing ratio of the fine particles is more than the above range, the adhesion to the substrate will be reduced. Further, when the mixing ratio of the fine particles is less than the above range, wet sprayability is deteriorated. Next, the liquid crystal display panel of the present invention will be described.

The liquid crystal display panel of the present invention is the same as the conventional liquid crystal display panel except that the above-mentioned adhesive spacer of the present invention is interposed between the electrode substrates in the conventional liquid crystal display panel.
It maintains the distance between the electrode substrates, and has the same or substantially the same gap distance as the particle diameter of the spacer. The adhesive spacer provided in the liquid crystal display plate is particularly excellent in wet sprayability, and even when wet-sprayed, there is no unevenness, and since it can be uniformly sprayed over the entire substrate,
The liquid crystal display panel of the present invention is expected to have higher contrast, less unevenness in gearing, and improved display quality.

The liquid crystal display panel of the present invention comprises, for example, a first electrode substrate, a second electrode substrate, a liquid crystal display plate spacer, a sealant and a liquid crystal. The first electrode substrate is
It has a first substrate and a first electrode formed on the surface of the first substrate. The second electrode substrate has a second substrate and a second electrode formed on the surface of the second substrate, and faces the first electrode substrate. The above-described spacer of the present invention is used as a spacer for a liquid crystal display panel, and is interposed between the first electrode substrate and the second electrode substrate to maintain a space between the electrode substrates. The sealant adheres the first electrode substrate and the second electrode substrate at a peripheral portion. The liquid crystal is sealed between the first electrode substrate and the second electrode substrate, and is filled in a space surrounded by the first electrode substrate, the second electrode substrate, and a sealing material.

For the liquid crystal display panel of the present invention, those other than the spacer, such as the electrode substrate, the sealant, and the liquid crystal, can be used in the same manner as the conventional ones. The electrode substrate has a substrate such as a glass substrate and a film substrate, and an electrode formed on the surface of the substrate.If necessary, an alignment film formed on the surface of the electrode substrate so as to cover the electrode is formed. Have more. As the sealing material, an epoxy resin adhesive sealing material or the like is used. As the liquid crystal, those conventionally used may be used, for example, biphenyl, phenylcyclohexane, Schiff base, azo, azoxy, benzoate, terphenyl, cyclohexylcarboxylate, biphenylcyclohexane , Pyrimidine, dioxane, cyclohexylcyclohexane ester, cyclohexylethane, cyclohexene, and fluorine liquid crystals can be used.

As a method for producing the liquid crystal display panel of the present invention, for example, the adhesive spacer of the present invention is used as an in-plane spacer by uniformly dispersing it on one of the two electrode substrates by a wet method. In, after dispersing the particle body used in the present invention as an adhesive seal material such as an epoxy resin as a seal portion spacer, put the one applied by means of screen printing or the like on the adhesive seal portion of the other electrode substrate, Pressure, and heating at a temperature of 100 to 180 ° C. for 1 to 60 minutes, or irradiation dose of 40 to 30
A method of obtaining a liquid crystal display plate by heating the adhesive sealing material by UV irradiation of 0 mJ / cm ² and then curing it, and then injecting liquid crystal and sealing the injection part can be mentioned. The invention is not limited by the method.
As the in-plane spacer, among the adhesive spacers of the present invention, those colored as described above are preferable because light leakage does not easily occur.

The liquid crystal display panel of the present invention is used for the same purpose as a conventional liquid crystal display panel, for example, as an image display device for a television, a personal computer, a word processor, a car navigation system, a PHS (personal digital assistant) and the like.

[0047]

EXAMPLES Specific examples of the present invention and comparative examples will be shown below, but the present invention is not limited to the following examples. Average particle size of particle body, particle size variation coefficient, and particles
Weight ratio of main body and thermoplastic resin : Adhesive spacer 5
g is weighed (the weight at this time is P ₁ ), put in a cylindrical filter paper, and a solvent in which the thermoplastic resin is dissolved is selected (for (meth) acrylic resin or (meth) acrylic-styrene resin, tetrahydrofuran is used). , Toluene and the like are preferred, and polyolefin is preferably toluene, xylene and the like), and the thermoplastic resin covering the adhesive particles is dissolved by Soxhlet extraction, and then only the particle body is taken out and vacuum dried at 100 ° C. to obtain the particles. The weight of the main body alone was measured (the weight of the main body of the particle is P ₂ ). The weight ratio of the particle body and the thermoplastic resin was calculated by the following formula. Weight ratio of particle body and thermoplastic resin (P) = (P ₁ −
P ₂ ) / P ₂ × 100 Further, the obtained particle main body was identified by FT-IR analysis and observed by an electron microscope to measure the particle size of 200 arbitrary particles in the photographed image, According to the above, the average particle diameter, the standard deviation of the particle diameter and the coefficient of variation of the particle diameter were determined.

[0048]

[Equation 1]

[0049]

[Equation 2]

[0050]

(Equation 3)

Average particle diameter of adhesive spacer : Determined from the above formula in the same manner as the particle body. Glass transition temperature of thermoplastic resin : The solvent was distilled off from the solution of the thermoplastic resin obtained by the Soxhlet extraction described above by an evaporator and further vacuum dried at 100 ° C to obtain a thermoplastic resin. The resulting thermoplastic resin is FT-IR
Identified by analysis. The glass transition temperature (Tg) was measured using a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer. Presence or absence of adhesion of fine particles : The presence or absence of adhesion of fine particles was confirmed by observing the surface of the adhesive spacer with an electron microscope. Further, the fine particle component was identified using an X-ray microanalyzer.

[Example 1] Benzoguanamine-melamine-formalin condensation-crosslinking cured spherical fine particles (average particle diameter 4.02 µm, variation coefficient of particle diameter 5.2)
%) 35 g, and 2-ethylhexyl acrylate-styrene copolymer as a thermoplastic resin (average particle size 0.4 μm).
m, glass transition temperature 60 ° C.) 7 g, and then hybridization system N manufactured by Nara Machinery Co., Ltd.
Adhesive particles (1) were obtained by using HS-0 type and subjecting the surface of the particle body to a thermoplastic resin by a high-speed air current impact method (coating step).

Next, the obtained adhesive particles (1) and, as fine particles, hydrophobic SiO ₂ fine particles (Nippon Aerosil Co., Ltd.)
Aerosil R972, average particle size about 16nm) 0.03
Adhesive particles (1) by mixing with 5 g in a ball mill
By attaching fine particles to the surface of (the attaching step),
An adhesive spacer (1) was obtained. As a wet spray solvent,
A mixed solvent consisting of 30 parts by volume of methanol, 20 parts by volume of isopropanol and 50 parts by volume of water was used, and the adhesive spacer (1) (in this case, in-plane spacer) 8 was 1% by weight in the mixed solvent. And ultrasonically dispersed. Table 2 shows the dispersion state of the adhesive spacer (1) in the obtained wet spray liquid.

Next, as shown in FIG.
A lower electrode substrate 110 which has been rubbed after forming an electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 on a lower glass substrate 11 of × 345 mm × 0.7 mm.
The wet spray solution was sprayed on the top for 1 to 10 seconds. Table 2 shows the sprayed state on the substrate at this time. On the other hand, 300 mm x 3
After forming an electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 on the upper glass substrate 12 having a size of 45 mm × 0.7 mm, rubbing was performed to obtain an upper electrode substrate 120. Then, the particle body (in this case, the seal part spacer) 3 dispersed in the epoxy resin adhesive seal material 2 so as to be 30% by volume was screen-printed on the adhesive seal part of the upper electrode substrate 120. .

Finally, the upper and lower electrode substrates 120 and 110
Are bonded via an adhesive spacer (1) 8 so that the electrode 5 and the alignment film 4 face each other, 1 kg / cm
A pressure of ² was applied and the adhesive sealing material 2 was heated and cured at a temperature of 150 ° C. for 30 minutes. After that, the gap between the two electrode substrates 120 and 110 was evacuated and then returned to atmospheric pressure to inject the STN liquid crystal 7 and seal the injecting portion. Then, P is formed outside the upper and lower glass substrates 12 and 11.
A VA (polyvinyl alcohol) -based polarizing film 6 was attached to obtain a liquid crystal display plate (1) for STN.

The STN liquid crystal display plate (1) thus obtained showed good display quality without image unevenness or display defects. [Examples 2 to 4] Example 1 except that the type and amount of the particle main body, the type and amount of the thermoplastic resin, and the type and amount of the fine particles were changed as shown in Table 1.
Adhesive spacers (2) to (4) and liquid crystal display plates (2) to (4) were prepared in the same manner as in. The results are shown in Table 2.
Shown in

As the particle body of Example 4, organic-inorganic composite particles obtained by the following method were used. 25% in a four-necked flask equipped with a cooling tube, thermometer, and dropping port
A solution (solution A) obtained by mixing 2.9 g of an aqueous ammonia solution, 10.1 g of methanol, and 141.1 g of water was added, and the amount was 25 ± 2
The solution was kept at 0 ° C. and stirred, and 10 g of γ-methacryloxypropyltrimethoxysilane, 15 g of vinyltrimethoxysilane, 5 g of tetraethoxysilane, 54 g of methanol and 2,2′-azobis- (as a radical polymerization initiator were added to the solution. 2.4-Dimethylvaleronitrile) 0.14
The solution mixed with g (solution B) was added from the dropping port, and γ-
Methacryloxypropyltrimethoxysilane was hydrolyzed and condensed. After 20 minutes while continuing stirring, the mixture was heated to 70 ± 5 ° C. in a N ₂ atmosphere to carry out radical polymerization.

After continuing heating for 2 hours, cooling to room temperature,
A suspension of polymer particles was obtained. This suspension was subjected to solid-liquid separation by filtration, and the obtained cake was washed with methanol to 3 times.
Repeated times, the obtained polymer particles were vacuum dried in a vacuum dryer at 300 ° C. for 2 hours to obtain organic / inorganic composite particles. The obtained composite particles have an average particle size of 3.85.
μm, variation coefficient of particle diameter 3.3%, amount of SiO ₂ constituting polysiloxane skeleton 60.0 wt%, 10% compression elastic modulus 1080 kg / mm ² , 10% residual displacement after deformation 2.2%, fracture The strength was 2.2 g.

Example 5 As the particle body, benzoguanamine-melamine-formalin condensation-crosslinking cured spherical fine particles (average particle diameter 4.02 μm, coefficient of variation of particle diameter 5.2)
%) 35 g, and 2-ethylhexyl acrylate-styrene copolymer as a thermoplastic resin (average particle size 0.4 μm).
m, glass transition temperature 60 ° C.) and 0.07 g of hydrophobic SiO ₂ fine particles (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd., average particle size about 16 nm) as fine particles, and then mixed in the same manner as in Example 1. An adhesive spacer (5) was obtained by a high-speed air current impact method. A liquid crystal display panel (5) was produced using the obtained adhesive spacer (5). Table 2 shows the results.

[Comparative Example 1] The same as Example 1 except that the adhesive particles (1) were used as they were as the adhesive spacers for comparison (1) without performing the step of adhering the fine particles. Thus, a comparative liquid crystal display panel (1) was produced. Table 2 shows the results.

[0061]

[Table 1]

*: Aerosil R972 manufactured by Nippon Aerosil Co., Ltd .: SiO ₂ ultrafine particles hydrophobized with CH ₃ group. Aerosil MOX80: Ultrafine particles of AL ₂ O ₃ / SiO ₂ mixed oxide. Titanium dioxide P25: High-purity TiO ₂ ultrafine particles. Aluminum oxide C: High-purity AL ₂ O ₃ ultrafine particles.

[0063]

[Table 2]

* 1: Microscopic observation result: A: No aggregation. ◯: Two aggregates are slightly observed, but almost no aggregates. X: There is a lot of aggregation and sediments immediately after standing. * 2: A: When the whole substrate is divided into 9 parts, the distribution density of each divided part is uniform and no aggregation is observed.

◯: The distribution density of each of the above divided sections is uniform, and two agglomerates are recognized in 5% or less of the whole. X: The distribution density of each of the above-mentioned divided sections is non-uniform, or agglomeration of 2 or more is recognized in 5% or more of the whole. * 3: ⊚: No image unevenness or display defects, little light leakage, and good display quality.

Good: Display quality is good with no image unevenness or display defects. X: Image unevenness and display defects occur and display quality is poor.

[0067]

EFFECTS OF THE INVENTION The adhesive spacer for liquid crystal display panel of the present invention is not only excellent in adhesiveness to the substrate, but also has little aggregation or unevenness in dispersion when wet-dispersed on the substrate, and can be uniformly dispersed. It has excellent properties. The method for producing an adhesive spacer for a liquid crystal display plate of the present invention can provide a method for easily and efficiently producing the adhesive spacer for a liquid crystal display plate as described above.

Since the liquid crystal display panel of the present invention includes the above-mentioned adhesive spacer as a spacer interposed between the electrode substrates, the spacer is unlikely to move, aggregate, or fall off,
Since the thickness of the liquid crystal layer can be kept uniform and constant, there are few image irregularities and display defects, and the display quality is excellent.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view illustrating one embodiment of a liquid crystal display panel of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 Adhesive sealing material 3 Seal part spacer 4 Alignment film 5 Electrode 6 Polarizing film 7 Liquid crystal 8 In-plane spacer 11 Lower glass substrate 12 Upper glass substrate 110 Lower electrode substrate 120 Upper electrode substrate

Claims (8)

[Claims] 1. An adhesive spacer for a liquid crystal display panel, comprising adhesive particles having a particle body and an adhesive layer covering the surface thereof, and fine particles adhered to the adhesive layer. 2. The adhesive spacer according to claim 1, wherein the adhesive layer is a layer containing a thermoplastic resin. 3. The adhesive spacer according to claim 1, wherein the fine particles have an average particle diameter of 1.0 μm or less. 4. The fine particles are inorganic fine particles.
The adhesive spacer according to any one of 1 to 3. 5. The inorganic fine particles are SiO ₂ , Al ₂ O.
The adhesive spacer according to claim 4, which is at least one selected from the group consisting of ₃ and TiO ₂ . 6. The adhesive spacer according to claim 1, wherein the two electrode substrates are opposed to each other, and the gap between the electrode substrates is maintained by being interposed between the electrode substrates. A liquid crystal display board comprising: a liquid crystal enclosed between the substrates. 7. A coating step of coating the surface of a particle body with an adhesive layer to obtain adhesive particles, and preparing fine particles in an amount of 0.001 to 10% by weight based on the adhesive particles. A method for producing an adhesive spacer for a liquid crystal display panel, which comprises a step of adhering the fine particles to the surface. 8. A step of coating the surface of a particle main body with a mixture containing a thermoplastic resin and fine particles, wherein the mixing ratio of the thermoplastic resin and the fine particles is 100 parts by weight of the particle main body. A method for producing an adhesive spacer for a liquid crystal display panel, which comprises 0.1 to 50 parts by weight of a resin and 0.01 to 20 parts by weight of the fine particles.