JP2001228484A - Adhesive spacer for liquid crystal display plate and liquid crystal display plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive spacer for a liquid crystal display plate which hardly causes dropping of the adhesive layer when the spacer is fixed and which has high adhesion strength with both of upper and lower substrates and to provide a liquid crystal display plate having high display quality that the liquid crystal layer has uniform thickness and does not cause irregular colors or the like even when vibration or shock is added at a high temperature. SOLUTION: The adhesive spacer for a liquid crystal display plate consists of a copolymer containing styrene and/or methylmethacrylate as the essential monomer units. The spacer has such thermal characteristics that the initiation temperature (Tfb) of flowing ranges 90 to 150 deg.C, the flowing temperature T1/2 by the 1/2 method ranges 120 to 180 deg.C, termination temperature Tend of flowing ranging 140 to 200 deg.C, T1/2-Tfb ranges 10 to 50 deg.C and Tend-T1/2 ranges over 0 and 20 deg.C, wherein Tfb, T1/2 and Tend are measured by a flow tester method under specified test conditions and satisfy the relation of Tfb<T1/2<Tend.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive spacer for a liquid crystal display panel which firmly adheres to both upper and lower substrates of a liquid crystal display panel and whose thickness of a liquid crystal layer is hardly changed, 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 particular, in order to keep the thickness of the liquid crystal layer more uniform and more constant, an adhesive spacer having spacer particles coated with an adhesive has been developed for the purpose of preventing the spacer from moving or falling off. Such a spacer is dried (wet or sprayed) on a substrate and then heated (usually at a temperature of 140 to 16 at which the sealing resin is sealed).
(0 ° C.).

As such an adhesive spacer, for example, an adhesive spacer obtained by coating the surface of cured spherical fine particles of an amino resin with a resin (for example, polymethyl methacrylate) having a heat deformation temperature in the range of 25 to 180 ° C. (See JP-A-1-150428), Mw (weight average molecular weight) in the range of 100,000 to 500,000, and a ratio (Mw / Mn) of Mw to Mn (number average molecular weight) of 2.0 to 2.0. 5 and a Tg (glass transition temperature) in the range of 60 to 90 ° C., the surface of which is coated with a (meth) acrylate resin (JP-A-8-101394).
And the like are known.

[0004]

The liquid crystal display panel obtained by using the conventional adhesive spacer has the following problems. If the heat deformation temperature or the glass transition temperature of the adhesive layer of the adhesive spacer is low, the adhesive layer is likely to soften. For this reason, the temperature at which the adhesive spacer is fixed to the substrate surface of the liquid crystal display panel (fixation temperature) can be reduced, so that a load is not easily applied to the liquid crystal display panel. However, if the heat deformation temperature or the glass transition temperature is low, the entire adhesive layer is likely to hang down due to gravity, and the adhesive strength to the upper substrate tends to decrease. Also, needless to say, if the obtained liquid crystal display panel is left at a high temperature (50 to 80 ° C.), re-softening of the adhesive layer occurs, and the fixing of the spacer becomes insufficient or the thermal expansion of the adhesive layer occurs. As a result, the thickness of the liquid crystal layer changes, the gap distance of the entire liquid crystal display panel becomes non-uniform, and color unevenness easily occurs.

When the heat deformation temperature or the glass transition temperature of the adhesive layer is high, the adhesive layer does not sag due to gravity, and the spacer is easily fixed to both the upper and lower substrates. However, since the adhesive layer is unlikely to be softened, if the fixing temperature is low, the spacer cannot be fixed with sufficient adhesive force. For this reason, it is necessary to increase the fixing temperature and sufficiently soften the adhesive layer to fix the spacer. However, when the fixing temperature is increased, a heat load is applied to the liquid crystal display panel, which causes problems such as thermal degradation. It will be easier. On the other hand, if the molecular weight distribution of the polymer constituting the adhesive layer of the adhesive spacer is too narrow (for example, Mw / Mn ≦
2.5) Since the adhesive layer softens at a substantially constant temperature,
The time for fixing the spacer can be reduced. However, in this case, unless the temperature of the entire liquid crystal display panel is made uniform, it is inevitable that the adhesive layer will be softened depending on the location where the spacers are scattered. The whole layer is easily sagged by gravity, and the adhesive strength to the upper substrate is easily reduced.

Accordingly, an object of the present invention is to provide an adhesive spacer for a liquid crystal display panel which has a small droop of the adhesive layer when fixed and has a high adhesive strength to both the upper and lower substrates, and is subject to vibration and impact at high temperatures. However, since the movement of the spacer and the thermal expansion of the adhesive layer are small, the liquid crystal layer has a uniform thickness, does not cause color unevenness or the like, and provides a liquid crystal display panel with high display quality.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies on the physical properties (thermal deformation temperature, glass transition temperature, molecular weight and molecular weight distribution, etc.) of conventionally known adhesive layers because the above-mentioned problems cannot be solved. The above-mentioned problems can be solved at once by making the adhesive layer of the adhesive spacer have a specific thermal property, and when a specific monomer is selected as a structural unit of the thermoplastic resin forming the adhesive layer, the adhesive is formed. The inventors have found that the force can be further increased, and arrived at the present invention. That is, the adhesive spacer for a liquid crystal display panel according to the present invention is an adhesive spacer for a liquid crystal display panel including a particle main body and an adhesive layer made of a thermoplastic resin covering at least a part of its surface. The resin is a copolymer essentially containing styrene and / or methyl methacrylate as a monomer unit, and has an outflow start temperature (T _fb ) in the range of 90 to 150 ° C.,
The outflow temperature (T _1/2 ) of the / 2 method is in the range of 120 to 180 ° C., and the outflow end temperature (T _end ) is 140 to 200 ° C.
T _1/2 -T _fb is in the range of 10 to 50 ° C., T
thermal properties in which _end −T _1/2 is greater than 0 and in the range of −20 ° C. (However, T _fb , T _1/2 and T _end are measured by a flow tester method under the following test conditions, T _fb <T
_1/2 <T _end ).

In the liquid crystal display panel according to the present invention, the above-mentioned adhesive spacer for a liquid crystal display panel is used as a spacer interposed between the electrode substrates.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an adhesive spacer for a liquid crystal display panel of the present invention will be described. Adhesive spacer for liquid crystal display panel: The adhesive spacer for a liquid crystal display panel of the present invention includes a particle body and an adhesive layer, and the adhesive layer is made of a thermoplastic resin and covers at least a part of the surface of the particle body. ing. The particle main body is necessary to keep the thickness of the liquid crystal layer uniform and constant when used for a liquid crystal display panel, for example, and the average particle diameter is preferably 1 to 30 μm.
m, more preferably 1 to 20 μm, most preferably 1 to
15 μm. When the average particle diameter is out of the above range, the particles 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 is
It is preferably at most 10%, more preferably at most 8%, even more preferably at most 6%. 10% particle size variation coefficient
When the ratio is more than 1, when used for a liquid crystal display panel, it is difficult to keep the thickness of the liquid crystal layer uniform and constant, and image unevenness is likely to occur. The definition and measurement method of the average particle diameter and the particle diameter variation coefficient in the present invention are those described in Examples below. The shape of the particle body is
Any particle shape such as spherical, needle-like, plate-like, scale-like, crushed, bale-like, cocoon-like, and confetti-like may be used, and is not particularly limited. In order to make the gap distance of the liquid crystal display plate uniform and constant. Spherical is preferred. This is because particles that are spherical have a constant or nearly constant particle size in all or almost all directions.

As the particle body, organic-inorganic composite particles or organic cross-linked polymer particles are used. This is because the organic-inorganic composite particles and the organic cross-linked polymer particles can easily prevent damage to the electrode substrate, the alignment film, or the color filter, and can easily obtain the uniformity of the gap distance between the two electrode substrates. The organic crosslinked polymer particles are not particularly limited. For example, curing of an amino resin obtained by a condensation reaction between formaldehyde and at least one amino compound selected from the group consisting of benzoguanamine, melamine and urea Particles (see JP-A-62-268811);
And divinylbenzene cross-linked resin particles obtained by polymerizing divinylbenzene alone or copolymerizing it with another vinyl monomer (see JP-A-1-144429).

The inorganic particles are not particularly restricted but include, for example, spherical fine particles such as glass, silica and alumina. The composite particles are composite particles including an organic portion and an inorganic portion. In the composite particles, the ratio of the inorganic portion is not particularly limited, for example, with respect to the weight of the composite particles,
In terms of inorganic oxide, it is preferably 10 to 90 wt%, more preferably 25 to 85 wt%, more preferably 30 to 8 wt%.
The range is 0 wt%. The term “inorganic oxide conversion” indicating the ratio of the inorganic portion is represented by a weight percentage obtained by measuring the weight before and after firing the composite particles at a high temperature (for example, 1000 ° C.) in an oxidizing atmosphere such as air. When the ratio of the inorganic portion of the composite particles is below the above range in terms of inorganic oxide, the composite particles become soft, and the number of sprayed particles on the electrode substrate may increase. As a result, damage to the alignment film and disconnection of the TFT may easily occur.

[0013] Such composite particles are not particularly limited, but include, for example, an organic polymer skeleton and an organic silicon in which a silicon atom is directly chemically bonded to at least one carbon atom in the organic polymer skeleton. And the polysiloxane skeleton contained in the above, and the amount of SiO ₂ constituting the polysiloxane skeleton is 25 wt% or more. When the composite particles A have G ≧
14. Y ^1.75 (where G indicates breaking strength [kg];
Y is preferably a breaking strength that satisfies the particle diameter [mm]), and the 10% compression modulus is 300 to 2000 kg.
/ Mm ² , and the residual displacement after 10% deformation is more preferably 0 to 5%. The composite particles A are also described below,
It may be colored by including a dye and / or a pigment.

The method for producing the composite particles A is not particularly limited, and examples thereof include a production method including the following condensation step, polymerization step and heat treatment step. The condensation step is a step of performing hydrolysis and condensation using the first silicon compound having a radical polymerizable group. The first silicon compound has the following general formula (1):

[0015]

Embedded image

(Wherein, R ^a represents a hydrogen atom or a methyl group; R ^b has 1 to 1 carbon atoms which may have a substituent)
R ^c represents at least one monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms; Show)
And the following general formula (2):

[0017]

Embedded image

(Where R ^d represents a hydrogen atom or a methyl group; ^Re is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms) At least one monovalent group), and the following general formula (3):

[0019]

Embedded image

(Wherein, R ^f represents a hydrogen atom or a methyl group; R ^g represents an optionally substituted C 1 -C 1)
R ^h represents at least one monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms; Show)
And at least one selected from the group consisting of compounds represented by at least one general formula selected from the group consisting of: and derivatives thereof. The polymerization step is a step in which a radical polymerizable group undergoes a radical polymerization reaction during and / or after the condensation step. The heat treatment step is a step of drying and firing the polymer particles generated in the polymerization step at a temperature of 800 ° C. or less.

The heat treatment step is performed, for example, in an atmosphere having an oxygen concentration of 10% by volume or less. During and / or after at least one step selected from the condensation step, the polymerization step, and the heat treatment step, the method may further include a coloring step of coloring generated particles. The particle body may be colored by including at least one selected from the group consisting of dyes and pigments. The color is preferably a color through which light is hardly transmitted or a color through which light is not transmitted, since light leakage of the adhesive spacer itself can be prevented and the contrast of image quality can be improved. The color that is difficult to transmit light or does not transmit, for example, black, dark blue, dark blue, purple, blue, dark green, green, brown, red, and the like, particularly preferably, black, dark Blue and dark blue.

The dye and / or pigment may be simply contained in the particle main body, or may have a structure in which the dye and / or pigment and the matrix constituting the particle main body are linked by a chemical bond. . In the adhesive spacer for a liquid crystal display panel of the present invention, at least a part of the surface of the particle body, that is, a part or the whole of the surface is covered with an adhesive layer made of a thermoplastic resin. Further, a part or all of the adhesive layer made of a thermoplastic resin may be chemically bonded to the surface of the particle body. Thermoplastic resins have certain thermal properties as described below.

The thickness of the adhesive layer is not particularly limited,
Usually, in the range of 0.01 to 2 μm, preferably 0.05 to
The range is 1 μm. If the thickness is smaller than the above range, the adhesiveness may be reduced.If the thickness is larger than the above range, the area covering the alignment film, the color filter, and the like becomes large, and the display quality of the liquid crystal display panel is reduced. There is fear. The average particle diameter of the adhesive spacer (the particle body having the thickness of the adhesive layer added thereto) is not particularly limited,
Preferably it is more than 1 μm and 32 μm or less, more preferably more than 1 μm and 22 μm or less, further preferably more than 1 μm and 17 μm or less.

The adhesive spacer of the present invention has a thermal property measured by a flow tester, and includes an outflow starting temperature (T _fb ) of a thermoplastic resin, an outflow temperature (T _1/2 ) according to a 法 method, The outflow end temperature (T _end ), T _1/2 -T _fb and T _end -T _1/2 are easily fixed to a substrate (fixation temperature), hard to damage, and applied to both upper and lower substrates. Is a parameter for determining the adhesive strength and the like. The outflow starting temperature (T _fb ) of the thermoplastic resin is 90 to 150 ° C., and preferably 1 to 150 ° C.
It is in the range of 100 to 140 ° C, more preferably 110 to 140 ° C. If T _fb is less than 90 ° C., the adhesive strength to both the upper and lower substrates tends to be low, and if the liquid crystal display panel is left at a high temperature (for example, 50 to 80 ° C.), re-softening of the adhesive layer tends to occur. As a result, the thickness of the liquid crystal layer tends to change due to the thermal expansion of the adhesive layer. Further, the area covering the alignment film and the color filter is increased, and these are likely to be damaged.
On the other hand, if T _fb exceeds 150 ° C., the adhesive layer is hardly softened, so that it is not sufficiently adhered to the substrate, and it is necessary to increase the fixing temperature, and the thermal load on the liquid crystal display panel tends to increase.

The outflow temperature (T
_1/2) Is from 120 to 180 ° C., preferably from 130 to 180 ° C.
180 ° C, more preferably in the range of 140 to 170 ° C
You. T _1/2Is less than 120 ° C. when immobilized on a substrate
The adhesive layer dissolved in
The adhesive strength to the substrate is likely to be low. On the other hand, T_1/2Is 1
If the temperature exceeds 80 ° C., the adhesive strength to the substrate decreases, and the fixing temperature
Need to be higher. Outflow end temperature of thermoplastic resin
(T_end) Is 140-200 ° C., preferably 14 ° C.
0-190 ° C, more preferably 150-180 ° C
It is in. T_endIf the temperature is lower than 140 ° C, fix to the substrate
The adhesive layer dissolved at the time of formation easily falls down due to gravity,
Adhesion to the upper substrate is likely to be low. On the other hand, T_endIs 2
If the temperature exceeds 00 ° C., the adhesive strength to the substrate tends to decrease.
You.

T which indicates the thermal characteristics of the thermoplastic resin_fb, T_1/2
And T_endIs always T_fb<T_1/2<T_endMeet the relationship
In either case, the temperature is raised by the flow tester method.
The rate was measured under the condition of 6.0 ° C./min.
The described measuring method is employed. Thermoplastic resin is above
Because of the thermal characteristics shown in the figure, the adhesive layer
The fall is small, the adhesive strength to both upper and lower substrates is high,
In addition, even if vibration or impact is applied under high temperature, the spacer
Less movement. Further, the above T_fb, T_1/2and
T_endIs T_1/2And T_fbTemperature difference (T_1/2-T _fb) Is 1
0 to 50 ° C range, T_endAnd T_1/2Temperature difference (T_end−
T_1/2) Is greater than 0 and in the range of ２０20 ° C. Preferably
T_1/2-T_fbIs in the range of 15 to 45 ° C. and T_end-T
_1/2Is in the range of 1 to 15 ° C., and more preferably T_1/2−
T_fbIs in the range of 15 to 40 ° C. and T_end-T_1/2Is 3 ~
It is in the range of 12 ° C. If the temperature difference is smaller than the above range,
Adhesion to the upper substrate is reduced. On the other hand, the temperature difference
Larger than the box, stable adhesive strength over the entire LCD panel
Poor sex.

The thermal properties (T _fb , T _1/2 , T
_end, summarized the T _1/2 -T _fb and T _end -T _1/2),
T _fb is 90 to 150 ° C., T _1/2 is 120 to 180 ° C., T
_end is 140 to 200 ° C, T _1/2 -T _fb is 10 to 50 ° C,
T _end -T _1/2 is in the range of more than 0 to -20 ° C. The thermal characteristics of the thermoplastic resin are preferably such that T _fb is 100 to 140.
℃, T _1/2 is 130~180 ℃, T _end is 140 to 190
° C, T _1/2 -T _fb is 15 to 45 ° C, T _end -T _1/2 is 1 to
15 ° C., and more preferably, T _fb is 110 to 110 ° C.
140 ℃, T _1/2 is 140~170 ℃, T _end is 150
_{180 ℃, T 1/2 -T} fb is 15~40 ℃, T _end -T _1/2
Is in the range of 3 to 12 ° C.

The specific example of the thermoplastic resin constituting the adhesive layer is not particularly limited as long as it acts as an adhesive to an electrode substrate or the like and has the above-mentioned thermal characteristics. Examples include a homopolymer or a copolymer of an ethylenically unsaturated monomer, and are selected from the group consisting of (meth) acrylic polymers, styrene polymers, and (meth) acryl-styrene polymers. Further, it is preferable that at least one kind is used because the adhesive strength to the substrate is large.
Among them, the glass transition temperature (Tg) of the homopolymer is 60 ° C.
The polymer containing the above-mentioned monomer as an essential unit is preferably used because it is easy to firmly adhere to both the upper and lower substrates, and the Tg of the homopolymer is more preferably 70 ° C. or higher, further preferably 80 ° C. That is all. Further, a copolymer in which a monomer unit essentially contains styrene and / or methyl methacrylate is more preferable. In particular, a copolymer containing styrene as a monomer unit is most preferable because the charge retention after 5 minutes of corona discharge described later increases.

The ethylenically unsaturated monomer is not particularly restricted but includes, for example, ethylene, propylene, vinyl chloride, vinyl acetate, styrene, vinyltoluene, α-methylstyrene, (meth) acrylate (for example, , Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, trifluoropropyl (meth) acrylate, and the like. Among these, those in which the ethylenically unsaturated monomer contains an aromatic residue (for example, a phenyl group) or a residue capable of hydrogen bonding (an ester group or the like) have a lower intermolecular force with the alignment film. This is preferable because the adhesive strength to the substrate increases and the adhesive strength to the substrate increases, and at least one selected from (meth) acrylates and styrene is more preferable. It is most preferable that styrene be essential as the ethylenically unsaturated monomer because the charge retention after 5 minutes of corona discharge described later increases. In particular, when polymerizing (meth) acrylic acid ester or styrene, those obtained by soap-free polymerization are preferable. This is because it is easy to obtain a material that satisfies the thermal characteristics of the flow tester, and does not use conductive impurities such as surfactants, so that the reliability of the liquid crystal display panel is easily improved and the charge retention described later is easily increased. For that reason.

[0030] The thermoplastic resin is not limited to those described 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 resin may be used alone or in combination of two or more. When the charge retention of the thermoplastic resin after 5 minutes of corona charging is 60% or more, the reliability of the liquid crystal display panel is improved, and light leakage around the spacer when vibration or impact is applied to the liquid crystal display panel. This is preferable because the increase can be prevented. The charge retention after 5 minutes of corona charging is more preferably 65% or more, further preferably 70% or more, and most preferably 75% or more.
In addition, as a method for measuring the charge retention, a method using an apparatus described in Examples described later can be adopted.

The thermoplastic resin may be colored by containing at least one selected from the group consisting of dyes and pigments. Preferred colors thereof include the colors described above as preferred colors of the particle body of the spacer.
Dyes and pigments that can be used for coloring the thermoplastic resin are not particularly limited, and include, for example, those described above as the dyes and pigments that can be used for coloring the particle body of the spacer. The weight ratio of the thermoplastic resin in the adhesive layer to the particle body is not particularly limited, but exceeds 0%, preferably 30% or less, more preferably 1 to 25.
%, Most preferably from 2 to 20%. When the weight ratio of the thermoplastic resin exceeds 30%, the adhesive layer increases, and when melted, the area covering the electrode substrate, the alignment film, and the color filter increases, and the image quality of the liquid crystal display panel may be degraded. . On the other hand, when the weight ratio of the thermoplastic resin is small, the adhesiveness decreases.

The adhesive spacer for a liquid crystal display panel of the present invention can be used in either a wet or dry spraying method. However, when used in a dry spraying method, there is no aggregation of the adhesive spacer. It is particularly suitable for dry spraying because it can be evenly sprayed. At that time, the fluidity defined by the method described below is preferably 50% or more, more preferably 55% or more, further preferably 60% or more,
Most preferably, it is at least 65%. The method for producing the adhesive spacer for a liquid crystal display panel of the present invention is not particularly limited, but preferred examples include a production method described in detail below. Manufacturing method of adhesive spacer for liquid crystal display panel: The manufacturing method of the adhesive spacer includes, for example, a coating step of coating at least a part of the surface of the particle main body with an adhesive layer made of a thermoplastic resin. As the thermoplastic resin, those having the above-mentioned thermal characteristics are used.

The specific method of coating the surface of the particle main body with the adhesive layer is not particularly limited. For example, particles to be used as the spacer particle main body are dispersed in a thermoplastic resin solution and sufficiently stirred. After mixing, the solvent is removed by evaporation, and a method of pulverizing the obtained lump or in a molten thermoplastic resin, dispersing the particles to be the particle main body of the spacer, kneading and sufficiently dispersing, Method of pulverizing aggregates after cooling; introducing various functional groups (vinyl group, epoxy group, hydroxyl group, etc.) on the surface of the particle body, polymerizing monomers starting from the functional groups, and reacting the functional groups with the polymer And then grafting to the particle surface.

[0034] In addition to the above method, "surface modification"
(Chemical Review No.44, edited by The Chemical Society of Japan, pp. 45-52, published in 1987) and “Powder Surface Modification and Highly Functional Technology” (“Surface”
Ins, which is described in detail in Vol. 25, No. 1, pp. 1 to 19 and a cover photograph, published in 1987), in which a monomer or a polymerization catalyst is localized at a core material interface to form a polymer wall and encapsulate.
Itu polymerization method; Coacervation method for generating concentrated phase dispersed droplets (coacervate); Monomer for polycondensation is separately added to the continuous phase and the dispersed phase of the liquid-liquid dispersion system, and the polymer film is homogeneous at the interface Interfacial polymerization method for forming a liquid; curing method in liquid; drying method in liquid; high-speed bombardment method in a high-speed air stream mixing at high speed in a dry state; air suspension coating method; Can be coated.

In particular, in the high-velocity air current impact method, for example, particles (particle bodies) to be the spacer particle bodies and a thermoplastic resin powder (thermoplastic resin powder) are mixed, and this mixture is subjected to gaseous mixing. Dispersing in the phase, by applying mechanical thermal energy mainly impact force to the particle body and the thermoplastic resin powder, is a method of coating the surface of the particle body with the thermoplastic resin. It is most preferable because it can be easily coated. The average particle diameter of the thermoplastic resin powder used when performing the high-speed airflow impact method is not particularly limited, for example, preferably 2 μm or less,
More preferably 1.8 μm or less, most preferably 1.5 μm
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%.
It is.

The apparatus utilizing the high-speed airflow impact method is not particularly limited. For example, a hybridization system manufactured by Nara Machinery Co., Ltd., a mechanofusion system manufactured by Hosokawa Micron Corp., or Kawasaki Heavy Industries, Ltd. Kryptron system. In addition,
The average particle diameter of the particle body used in the coating step is preferably the above-mentioned particle diameter. Next, the liquid crystal display panel of the present invention will be described. Liquid crystal display panel: The liquid crystal display panel of the present invention is different from the conventional liquid crystal display panel in that the above-mentioned adhesive spacer for a liquid crystal display panel of the present invention is interposed between the electrode substrates instead of the conventional spacers. Is maintained, and
It has the same or substantially the same gap distance as the particle diameter of the spacer.

The liquid crystal display panel of the present invention includes, for example, a first electrode substrate, a second electrode substrate, a spacer, a sealing material, and a liquid crystal. The first electrode substrate has a first substrate and a first electrode formed on a 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 spacer is an adhesive spacer for a liquid crystal display panel according to the present invention, and serves to maintain a gap between the first and second electrode substrates by interposing the first and second 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.

In the liquid crystal display panel of the present invention, those other than spacers, such as an electrode substrate, a sealing material, and a liquid crystal, can be used in the same manner as in the prior art. 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 manufacturing the liquid crystal display panel of the present invention, for example, a method in which the adhesive spacer of the present invention is uniformly dispersed on one of two electrode substrates as an in-plane spacer, After dispersing the particle main body used in the present invention in an adhesive sealing material such as an epoxy resin as a sealing spacer, the one applied by means such as screen printing on the adhesive sealing portion of the other electrode substrate is placed, and an appropriate pressure is applied. In addition, at a temperature of 140 to 160 ° C,
After heating and curing the adhesive sealant by heating for 60 minutes, a method of injecting liquid crystal and sealing the injection portion to obtain a liquid crystal display panel can be mentioned. The invention is not limited. Among the in-plane spacers, among the adhesive spacers of the present invention, those colored as described above are preferable because the spacers themselves hardly leak light.

Since the liquid crystal display panel of the present invention uses the above-mentioned adhesive spacer, the adhesive strength to both the upper and lower substrates is strong, the movement of the spacer is reduced, and the thickness of the liquid crystal layer is made uniform. In addition, color unevenness does not occur and display quality is improved. Therefore, it is preferably used for applications that are subject to vibration or opposition, for example, for in-vehicle use such as car navigation.
Personal computer, word processor, PH
It may be used as an image display element such as S (portable information terminal). Further, the charge retention rate of the thermoplastic resin forming the adhesive layer of the adhesive spacer after 60 minutes of corona charging is 60%.
With the above, the increase in light leakage around the spacer is extremely small even when vibration or impact is applied. Therefore, it is particularly useful as a large display element of 11 inches or more or a display element mounted on a car.

[0041]

EXAMPLES Examples of the present invention and comparative examples will be shown below, but the present invention is not limited to the following examples. In the following example,
The average particle diameter and the particle diameter variation coefficient of the particle body of the spacer, the thermal characteristics of the thermoplastic resin, the charge retention after 5 minutes of corona charging and the fluidity were measured by the following methods. Average particle size and particle size variation coefficient: Observing a sample with an electron microscope, actually measuring the particle size of 200 samples of the photographed image, and calculating the average particle size, the standard deviation of the particle size, and the particle size according to the following equations. Was determined.

[0042]

(Equation 1)

[0043]

(Equation 2)

[0044]

(Equation 3)

Thermal characteristics: Using a Shimadzu flow tester model CFT-500C manufactured by Shimadzu Corporation, the outflow starting temperature (T _fb ) and the outflow temperature of the half method (T _fb ) were _measured by the temperature raising method (flow tester method) under the following conditions. T _1/2 ) and the outflow end temperature (T _end ) were determined. Die (Die hole diameter 0.50mm x die length 1.00m
m) was fitted into the die holder and lightly screwed into the cylinder. After attaching the die hole stopper, a weight of 1 kg was placed (test load: 20.0 kgf). When the cylinder temperature reached 80 ° C., 1.0 g of a sample was charged and the piston was pushed. While preheating at 80 ° C. for 300 seconds, the air in the sample was evacuated, the die hole stopper was removed 10 seconds before the end of preheating, and a test was performed under the following conditions.
_fb ), the outflow temperature (T _1/2 ) of the _1/2 method, and the outflow end temperature (T _end ) were determined.

Test conditions: Start temperature 80 ° C. End temperature 230 ° C. Heating rate 6.0 ° C./min Test load 20.0 kgf Die hole diameter 0.50 mm Die length 1.00 mm Outflow start temperature (T _fb ), 1 / The outflow temperature (T _1/2 ) and the outflow end temperature (T _end ) of the two methods will be described in detail below. The flow tester CFT-500C is a capillary rheometer that measures the viscous resistance of the melt as it passes through the capillary. This structure is shown in FIG. 2 where the sample is loaded into a cylinder, heated and melted from the surroundings, and a constant pressure is applied by a piston from above. By operating in this manner, the molten sample is extruded through a die having a small hole, and the flow rate Q (cm
^{From 3} / s), the fluidity of the sample, that is, the melt viscosity is determined.

Flow rate Q (cm ³ / s) = (x / 10) · (A /
t) (where, t: measurement time (s), x: amount of movement of the piston with respect to measurement time (mm), A: cross-sectional area of the piston) In this apparatus, a test is performed at a constant temperature. Constant temperature method,
Two types of test modes can be selected: the temperature rise method, which measures the fluidity of the sample while the temperature rises as the test time elapses, and the temperature rise method (flow tester method) Since the rheological properties in a wide temperature range from the region to the flow region can be determined by one measurement, the present invention employs a temperature rising method.

The temperature raising method is a method of performing a test while raising the temperature at a constant rate with the elapse of the test time. In this test, the process from the solid region to the transition region, through the rubbery elastic region to the flow region can be continuously measured, and the softening temperature Ts when the sample moves from the solid region to the transition region, and the sample flows out The outflow start temperature T _fb and the outflow end temperature T _{end at} which the sample ends flowing can be measured. The flow curve in the temperature raising method shows, for example, a behavior as shown in FIG. Table 1 shows a detailed description of FIG.

[0049]

[Table 1]

The outflow temperature of the 1/2 method is obtained by calculating the half of the difference between the outflow end point Smax and the minimum value Smin in the flow curve shown in FIG. 4 (x = (Smax-Smin) / 2). x
And the temperature at the point A where Smin is added, that is,
It becomes the melting temperature in the 1/2 method. Charge retention: Measured by the following method using the apparatus shown in FIG. FIG. 5 shows the corona charging characteristic measuring device 1. The corona charging characteristic measuring device 1 includes a measuring unit for charging a powder (thermoplastic resin) by corona discharge to detect a surface potential, a conveying unit for conveying the powder, and a control unit for controlling the device. ing. The components of the device 1 are mounted or housed in casings 2A, 2B, 2C, 2D.

The measuring unit is a high voltage adjusting sliderac 1.
0, a neon transformer 11, a high-voltage display voltmeter 13, a corona discharge electrode 30, a surface potential detector 31, and a high-voltage diode 32. A high-voltage adjusting sliderac 10 is electrically connected to the primary side (input side) of the neon transformer 11 (see FIG. 5). Slidac 10
Is disposed inside the casing 2A located at the lower left side. The neon transformer 11 is disposed inside a casing 2B located on the upper left side. When a voltage from an external power supply is input to the primary side of the neon transformer 11 through the slider box 10, the transformer 11
High voltage (for example, several kV) boosted according to the transformation ratio of
Output. When power is being input from the external power supply, the high voltage display lamp 14 is turned on, and when there is no input from the external power supply, the lamp 14 is turned off. When power is being output from the secondary side of the transformer 11, the high voltage display lamp 15 is turned on, and when there is no output from the secondary side, the lamp 15 is turned off. The lamps 14, 15 and the voltmeter 13 are provided on the front wall of the casing 2B. This front wall is not shown so that the internal transformer 11 can be seen.

The voltmeter 13 is graduated so as to measure the primary-side voltage value of the neon transformer 11 and to display a value obtained by multiplying the primary-side voltage value by a transformation ratio as a secondary-side voltage value. . The corona discharge voltage is adjusted with high precision by the sliderac 10 using the display value of the voltmeter 13. The corona discharge electrode 30 is installed inside the casing 2 </ b> D at the center of the apparatus 1 near the center of the running path of the transport unit so as to discharge right below. The diode 32 is connected to the casing 2
D, which is disposed outside the upper wall of D, has a forward diode 32A and a reverse diode 32B, and one of the diodes is connected to the corona discharge electrode 30 and the neon transformer 11 by a switch (not shown). It is electrically connected to the secondary side. With this switch, the polarity of the electric charge of the powder 22 is selected. When the diode 32A is connected, the powder 22 is positively charged. When the diode 32B is connected, the powder 22 is negatively charged.

The surface potential detector 31 is installed inside the casing 2D at a position near one end of the running path of the transporting unit.
It has a vibrating electrode (not shown) at its lower end. The surface potential detector 31 indirectly measures the surface potential of the powder 22 via the vibration electrode. The transport unit is configured by a transport mechanism 20 provided substantially at the center of the apparatus 1. As shown in FIG. 6, the transfer mechanism 20 includes a transfer floor 27 and a transfer table 24.
, A moving wire 26, a drive motor 28, and two rails 49 and 50. The transfer floor 27 is installed on the bottom surface in the casing 2D. On the transfer floor 27, two rails 49, 50 are laid in parallel to form a runway.

The transfer table 24 places the powder 22 on the upper surface. The wheels 24a mounted on the lower surface roll back and forth on the rails 49 and 50 in the forward and reverse directions. The moving wire 26 forms a closed loop that passes above and below the transport floor 27, is attached to the transport platform 24, passes over the runway, and is hung on pulleys installed at both ends of the runway. The drive motor 28 is attached to an upper wall of the casing 2A, and reciprocates the wire 26. The drive motor 28 is a stepping motor in this embodiment, but may be an AC or DC servo motor.

On the upper surface wall of the casing 2D at the upper end of the other end of the runway, there is provided an openable / closable outlet 3 for placing the powder 22 on the carrier 24 or removing the powder 22 from the carrier 24. As shown in FIG. 7, the control unit includes a control box 40, an outlet position detector 51, a corona discharge position detector 52, a measurement position detector 53, a transport control circuit 55, a discharge control circuit 56, and a surface potential detection circuit 57. It has. The control box 40 is disposed inside the casing 2 </ b> C substantially at the lower right of the apparatus 1, and is used for applying a voltage to the power switch 41, a power lamp 42 for displaying an operation state of the power switch 41, and the corona discharge electrode 30. A high-voltage switch 43, a display lamp 44 for displaying an operation state of the high-voltage switch 43, an operation switch 45 operated to move the carrier 24 to the right in the drawing,
Display lamp 4 for displaying the operation state of the operation switch 45
6. An operation switch 47 for operating the transfer table 24 in the left direction in the figure is provided, and a display lamp 48 for displaying an operation state of the operation switch 47 is operated by an operator.

The take-out port position detector 51 is a sensor provided beside the rail 49 (or 50) at the other end of the track, and detects the position when the carriage 24 is located below the take-out port 3 (original position). Output a signal. The corona discharge position detector 52 is a sensor provided beside the rail 49 (or 50) at the center of the track, and the carrier 24 is provided with the corona discharge electrode 3.
When it is located just below 0, a position detection signal is output. The measurement position detector 53 is a sensor provided beside the rail 49 (or 50) near one end of the track below the surface potential detector 31, and is located when the carrier 24 is located directly below the surface potential detector 31. Outputs a detection signal.

The control section is divided into a transport control block 59, a discharge control block 60, and a measurement control block 61.
The transport control block 59 includes a transport control circuit 55. The transfer control circuit 55 controls the rotation direction and the rotation speed of the drive motor 28 based on the transfer signal from the control box 40. The transport signal is output when the operation switch 45 or the operation switch 47 is operated to the ON side. The drive motor 28 moves the carrier 24 by moving the wire 26 according to the carrier signal. The discharge control block 60 includes a discharge control circuit 56. The discharge control circuit 56 outputs a corona discharge signal by turning on the high-voltage switch 43, inputs a voltage to the primary side of the transformer 11, and outputs corona discharge from the corona discharge electrode 30. The discharge control circuit 56 receives position detection signals from the take-out position detector 51, the corona discharge position detector 52, and the surface potential measurement position detector 53. Only when the position detection signals from the detectors 51 and 53 are not input, the discharge control circuit 56 that outputs the corona discharge signal receives the position detection signal from the detector 52 and then outputs the position from the detector 52. When the detection signal stops being input, the corona discharge is stopped. For this reason, the corona discharge electrode 30 that is performing corona discharge immediately after the carrier 24 has passed therebelow,
Stop corona discharge.

The measurement control block 61 includes a surface potential measurement position detector 53, a surface potential detection circuit 57, and a recorder 58. The surface potential detection circuit 57 detects the surface potential signal from the surface potential detector 31 on condition that the position detection signal from the detector 53 is input. The recorder 58 records the detected surface potential signal as a surface potential in a time series. This record is stored in detectors 51 and 52.
Is not input and the detector 5
3 is performed, that is, when the carrier 24 is at the position of the surface potential detector 31. The above-described corona charging characteristic measuring apparatus is operated as follows to measure the surface potential and the charge retention (see FIG. 8).

First, the power switch 41 is turned on.
The high voltage switch 43 and the transport switches 45 and 47 are O
Leave in the FF state. After opening the take-out port 3 and placing the powder 22 on the transfer table 24 located below the take-out port 3,
The outlet 3 is closed and the operation switch 47 is operated to the ON side. The transport control circuit 55 receives the transport signal output by the ON operation of the switch 47 and rotates the drive motor 28 in a predetermined direction. Thereby, the moving wire 26
Is driven to move the carrier 24 to the left (FIG. 8A).
), The take-out position detector 51 stops outputting a position detection signal. The transfer table 24 that has moved to the left passes under the corona discharge electrode 30 that has not been subjected to corona discharge (see FIG. 8B), and as shown in FIG. Surface potential measurement position detector 5 when it reaches just below
3 outputs a position detection signal, and no carrier signal is input to the carrier control circuit 55.
Automatically stops just below 1. At this time, the surface potential measurement position detector 53 outputs a position detection signal, the detectors 51 and 52 do not output position detection signals, and the surface potential detector 31 outputs a surface potential signal of the powder 22 to be processed. , A surface potential detection circuit 57 detects a surface potential signal. The recorder 58
The detected surface potential signal is recorded as the surface potential A (V) after molding. The movement time of the transfer table 24 from the take-out position to the surface potential measurement position is within 1 second.

After this recording, the operator operates the operation switch 45 to the ON side. Transport control circuit 55
Receives the transport signal output by the ON operation of the switch 45 and rotates the drive motor 28 in a predetermined direction.
As a result, the moving wire 26 is driven to move the transfer table 24.
Moves to the right, and the surface potential measurement position detector 53 stops outputting a position detection signal. Carrier 24 moved to the right
Passes below the corona discharge electrode 30 where no corona discharge has occurred, and reaches just below the outlet 3 as shown in FIG. 8A, the take-out position detector 51 outputs a position detection signal. Then, the transport signal is not input to the transport control circuit 55, and the transport table 24 automatically stops immediately below the outlet 3.

Next, the input voltage on the primary side is adjusted with the SLIDAC 10 so that the output voltage on the secondary side of the neon transformer 11 becomes 3.6 kV. A switch (not shown) is used to electrically connect the forward diode 32A (or the reverse diode 32B) between the corona discharge electrode 30 and the secondary side of the neon transformer 11, and
Select the polarity of charge 2 and turn on the high voltage switch 43
Operate to the side. After this operation is performed, when the operator operates the operation switch 47 to the ON side, the carrier 24 starts to move to the left. When the carrier 24 passes directly below the corona discharge electrode 30 where corona discharge occurs (see FIG. 8B), the powder 22 passes through the corona discharge,
Instantly charges to the selected polarity. Only when the transfer table 24 passes directly below the corona discharge electrode 30, only the corona discharge position detector 52 outputs a position detection signal. After this,
The high voltage switch 43 is automatically turned off, and the corona discharge ends.

As shown in FIG. 8C, the transfer table 24 having passed just below the corona discharge electrode 30 is used as the surface potential detector 3.
When the position reaches just below 1, the take-out position detector 51 and the corona discharge position detector 52 do not output a position detection signal, and only the surface potential measurement position detector 53 outputs a position detection signal. By the output of the position detection signal, the transport control circuit 5
5 automatically stops immediately below the surface potential detector 31 because the carrier signal is no longer input thereto, and outputs a surface potential signal of the powder 22 detected by the surface potential detector 31 via the vibrating electrode, thereby providing a surface potential detection circuit. 57 detects the surface potential signal, and the recorder 58 records the detected surface potential signal as the surface potential of the powder 22 in time series. The first surface potential signal detected is the measured surface potential B1 immediately after corona charging.
(V) The surface potential signal detected after 5 minutes is the measured surface potential B2 (V) 5 minutes after corona charging. The moving time of the transfer table 24 from the take-out position to the surface potential measurement position is 1
Within seconds.

After the above series of operations has been completed, the operation switch 45 may be operated to the ON side in order to move the carrier 24 to the take-out position. Both positive and negative charges can be applied to the powder, the corona discharge electrode and the surface potential detector are provided at a predetermined distance, and they do not operate at the same time. It is possible to accurately measure the charging characteristics of the body (the time-dependent change in the surface potential and the attenuation characteristics) without being affected by disturbance due to noise or the like. In the present invention, the thermoplastic resin powder is
After standing at 60 ° C. and 60% RH for 16 hours, a metal cell having a diameter of 7.6 cm and a height of 0.5 cm (FIG. 9, (a) plan view and (b) sectional view) has a diameter of 5 cm and a depth of 5 cm. 0.3c
m, and the upper surface thereof is made as flat as possible so as not to protrude from the upper surface of the cell.
4 and the above-described apparatus and method (applied voltage to the corona discharge electrode 30 at the time of corona discharge is 3.6 kV, the distance between the corona discharge electrode 30 and the powder 22 is 2 cm, and the powder 22 is negatively charged). The distance between the surface potential detector 31 and the powder 22 at the time of measurement was 2 m.
m) Using the surface potential after standing for 16 hours after molding (A), the measured surface potential immediately after corona charging (B1), and the measured surface potential 5 minutes after corona charging (B2), corona charging for 5 minutes by the following equation The subsequent charge retention (Ec) is calculated. 20 measurements
It is performed in an atmosphere of 60 ° C. and 60% RH.

[0064]

(Equation 4)

[0065] (where, Ec is the charging retention corona charging after 5 minutes (%); Q ₁ is an charge amount after standing 16 hours after molding; Q ₂ is an amount of charge immediately after the corona charging ; Q
₃ is an electrification quantity of corona charging 5 minutes after; C is an electrostatic capacitance of the thermoplastic resin; A is the surface potential after standing 16 hours after molding (V); B ₁ is measured immediately after the corona charging it is a surface potential (V); B ₂ is measured surface potential of the corona charging after 5 minutes (V). ) Fluidity: The fluidity of the adhesive spacer of the present invention was determined by the following method. Two types of sieves (diameter: 8 cm) manufactured by Iida Manufacturing Co., Ltd. were superposed from the top in the order of 150 μm and 75 μm in opening diameter. 2.0 g of a sample (adhesive spacer) is uniformly placed on the upper sieve (150 μm) over the entire surface of the sieve so that the surface is as flat as possible, and the amplitude is 1 mm using a powder tester PT-E manufactured by Hosokawa Micron Corporation. After the sample was vibrated up and down at 60 Hz for 120 seconds, the weight ratio (%) (mesh passing ratio) of the sample passed through the lower sieve (75 μm) to the first sample (2.0 g) was regarded as fluidity.

Prior to Examples and Comparative Examples, a thermoplastic resin used for the adhesive layer of the spacer was synthesized according to the following synthesis examples. <Synthesis Examples 1 to 8> Thermoplastic resins (1) to (8), which are eight kinds of (meth) acryl-styrene resins or (meth) acrylic resins shown in Table 2, were synthesized by soap-free polymerization. did. For the obtained thermoplastic resins (1) to (8), the thermal characteristics, the charge retention after 5 minutes of corona charging, and the particle size were measured by the methods described above.

Next, the following examples and comparative examples were performed using the thermoplastic resins (1) to (8). <Example 1> Co-hydrolysis of alkoxysilyl groups using γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane (45/55 weight ratio)
By performing polycondensation and radical polymerization of double bonds,
White organic-inorganic composite particles (1) were obtained. The composite particles (1) have an average particle diameter of 5.5 μm, a particle diameter variation coefficient of 2.9%, and a polysiloxane skeleton ratio of 54 wt% in terms of SiO _{2 with} respect to the weight of the composite particles (1).
(When fired at 1000 ° C. in air).

Next, 35 g of the composite particles (1) and 3.5 g of the thermoplastic resin (1) were mixed, and then mixed in a high-speed air stream using a hybridization system NHS-0 manufactured by Nara Machinery Co., Ltd. By coating the surface of the composite particles (1) with the thermoplastic resin (1) by the impact method,
An adhesive spacer (1) was obtained. The adhesive spacer (1) is dried by a dry spraying method using an electrostatic dispersion method to form a 300
It was scattered over a rectangular electrode substrate having a size of 345 mm × 345 mm, and 25 observation sections having the same area on the substrate were selected. An observation section having a cluster of three or more particles was counted, and it was found to be one place. .

Next, a liquid crystal display panel was manufactured by the following method using the adhesive spacer (1) as a spacer. As shown in FIG. 1, first, 300 mm × 345 mm
An electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 were formed on a lower glass substrate 111 of × 1.1 mm, and rubbing was performed to obtain a lower electrode substrate 110. The adhesive spacer (1) (in this case, the in-plane spacer 8) was sprayed on the lower electrode substrate 110 by a dry spraying method using an electrostatic dispersion method. On the other hand, 300mm x 345m
After forming an electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 on an mx1.1 mm upper glass substrate 12, rubbing was performed to obtain an upper electrode substrate 120.
Then, three composite particles (1) (in this case, the sealing portion spacer 113) are contained in the epoxy resin adhesive sealing material 112.
What was dispersed so as to be 0% by volume was screen-printed on the adhesive seal portion of the upper electrode substrate 120.

Finally, the upper and lower electrode substrates 120, 110
So that the electrode 5 and the alignment film 4 face each other,
Bonding is performed via the spacer 8, a pressure of 1 kg / cm ² is applied thereto, and the mixture is heated at a temperature of 140 ° C. for 30 minutes to heat and cure the adhesive sealant 112 and the upper and lower electrode substrates 12.
0,110. Then, the two electrode substrates 12
The gap between 0 and 110 was evacuated and returned to atmospheric pressure to inject the STN liquid crystal 7 and seal the injection portion. Then, a PV is provided outside the upper and lower glass substrates 12 and 111.
A. A (polyvinyl alcohol) based polarizing film 6
A 3-inch liquid crystal display panel (1) was used.

According to the method described above, the liquid crystal display panel (1) using the adhesive spacer (1) as the spacer.
When the voltage was applied such that the gap distance was uniform and the transmissivity was 5%, light leakage around the spacer was small and the display quality was good. The characteristics of the liquid crystal display panel (1) were evaluated by the following methods. Table 4 shows the results. Dry spraying property: The degree of aggregation at the time of spraying was evaluated by the method described above. Adhesion between upper and lower substrates: The liquid crystal display panel was disassembled, the upper and lower substrates were peeled off, and the liquid crystal was washed with methanol. Next, the substrate was dried, and it was observed with an SEM (scanning electron microscope) whether or not the adhesive spacer remained on both the upper substrate and the lower substrate. Color unevenness when left at high temperature: 7
By leaving the substrate at 0 ° C. for 500 hours, it was observed whether or not color unevenness was caused by unevenness in the gap distance between the substrates. Increase in light leakage around the spacer after the impact test: After annealing the liquid crystal display panel at 120 ° C., and then performing a hit test 1000 times, a voltage was applied so that the transmittance became 5%.
It was observed whether or not light leakage around the spacer increased compared to before the beating test.

<Examples 2 to 6> Adhesive spacers (2) to (2) were prepared in the same manner as in Example 1 except that the types and amounts of the particles and the thermoplastic resin were as shown in Table 3. (6) was produced. The dry spraying properties of these spacers were examined in the same manner as in Example 1, and the results were shown in Table 4.
Shown in Next, using the adhesive spacers (2) to (6), liquid crystal display panels (2) to (6) were produced in the same manner as in Example 1. The characteristics of the obtained liquid crystal display panels (2) to (6) were evaluated in the same manner as in Example 1. Table 4 shows the results.

Comparative Examples 1 and 2 Comparative adhesive spacers (11) were prepared in the same manner as in Example 1 except that the types and amounts of the particle bodies and the thermoplastic resin were as shown in Table 3. ) To (12). The dry dispersibility of these spacers was examined in the same manner as in Example 1, and the results are shown in Table 4. Next, comparative liquid crystal display panels (11) to (12) were produced in the same manner as in Example 1 using the adhesive spacers (11) to (12) for comparison. The characteristics of the obtained comparative liquid crystal display panels (11) and (12) were measured in Example 1.
Was evaluated in the same manner as described above. Table 4 shows the results.

[0074]

[Table 2]

[0075]

[Table 3]

[0076]

[Table 4]

In the above Table 4, the criteria for the evaluation of each characteristic are as follows. [Dry spraying property] ：: good. Δ: Normal. ×: Bad. [Adhesive strength] A: The number of remaining spacers is large. X: The number of remaining spacers is small. [Generation of color unevenness when left at high temperature] ：: No generation. X: Occurrence occurred. [Increase in light leakage around the spacer after the 1000-time hit test] ○: No increase. Δ: Increase slightly. X: Increase is large.

[0078]

According to the adhesive spacer for a liquid crystal display panel of the present invention, the adhesive layer covering at least a part of the surface of the particle main body is made of the thermoplastic resin having the above-mentioned specific thermal characteristics. The adhesive layer does not hang down, and the adhesive strength to both the upper and lower substrates is improved. Therefore, when this adhesive spacer is used, specifically, during manufacture of a liquid crystal display panel, during transportation or use, it is difficult for the spacer to move or fall off, and the obtained liquid crystal display panel is subjected to high temperatures. It is difficult to change the thickness of the liquid crystal layer even when left untouched, and light leakage around the spacer is small, so that image unevenness and display defects of the liquid crystal display panel can be reduced, and the high display quality of the liquid crystal display panel is maintained for a long time Can be done.

The liquid crystal display panel of the present invention uses the above-mentioned adhesive spacer as a spacer interposed between the electrode substrates, so that high display quality can be maintained even when vibration or impact is applied.

[Brief description of the drawings]

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

FIG. 2 is a schematic view of an apparatus for measuring the thermal characteristics of a thermoplastic resin according to the present invention.

FIG. 3 is a schematic view showing a flow curve (heating method) obtained in measuring the thermal characteristics of the thermoplastic resin in the present invention.

FIG. 4 shows the thermal characteristics (1/2) of the thermoplastic resin in the present invention.
FIG. 3 is a schematic diagram for explaining a method of calculating the outflow temperature of the method.

FIG. 5 is a schematic longitudinal sectional view of an apparatus for measuring corona charging characteristics according to the present invention.

6 is a partial plan view of a transport mechanism of the apparatus shown in FIG.

7 is a block diagram of a control unit of the device shown in FIG.

8 is an operation explanatory diagram of the device shown in FIG. 5;

9 is a plan view and a cross-sectional view of a cell in which spacer particles are placed in the apparatus shown in FIG.

[Explanation of symbols]

 7 Liquid crystal 8 In-plane spacer 113 Seal part spacer 110 Lower electrode substrate 120 Upper electrode substrate

Claims (3)

[Claims] 1. An adhesive spacer for a liquid crystal display panel comprising a particle main body and an adhesive layer made of a thermoplastic resin covering at least a part of its surface, wherein the thermoplastic resin contains styrene as a monomer unit and styrene as a monomer unit. And / or a copolymer essentially containing methyl methacrylate, having an outflow starting temperature (T _fb ) of 90 to 150 ° C.
And the outflow temperature (T _1/2 ) of the _1/2 method is 120 to 18
0 ° C. range and outflow end temperature (T _end ) is 140-
Thermal characteristics in the range of 200 ° C., T _1/2 −T _{fb in} the range of 10 to 50 ° C., and T _end −T _{1/2 in} the range of more than 0 to 20 ° C. (however, T _fb , T _{1 / 2} and T _end were measured by the flow tester method under the following test conditions.
_fb <T _1/2 having <satisfy the relationship of T _{end The),} a liquid crystal display panel for adhesive spacer, characterized in that. 2. The adhesive spacer for a liquid crystal display panel according to claim 1, wherein said thermoplastic resin is obtained by soap-free polymerization. 3. A liquid crystal display panel using the adhesive spacer for a liquid crystal display panel according to claim 1 or 2 as a spacer interposed between electrode substrates.