WO2012121379A1

WO2012121379A1 - Spacer for liquid crystal display element, spacer fluid dispersion for liquid crystal display element, and liquid crystal display element

Info

Publication number: WO2012121379A1
Application number: PCT/JP2012/056153
Authority: WO
Inventors: 永井　康彦; 敬三西岡
Original assignee: 積水化学工業株式会社
Priority date: 2011-03-09
Filing date: 2012-03-09
Publication date: 2012-09-13
Also published as: JP5087187B2; CN103097950A; CN103097950B; JPWO2012121379A1

Abstract

Provided is a spacer for a liquid crystal display element that can prevent the occurrence of light leakage and thread-like domains, and enhance the display quality of the liquid crystal display element without disturbing the orientation of the liquid crystals. Also provided is a liquid crystal display element that employs the spacer for a liquid crystal display element. This spacer (1) for a liquid crystal display element is provided with base particles (2), and a resin layer (3) disposed over a surface (2a) of the base particles (2). The resin layer (3) is formed using a compound having C_24-30 alkyl groups, and a compound having an alkylene ether structure. This liquid crystal display element is provided with: a pair of substrates constituting a liquid crystal cell; liquid crystals disposed between the pair of substrates; and the spacer (1) for a liquid crystal display element, the spacer being sealed in between the pair of substrates.

Description

Liquid crystal display element spacer, liquid crystal display element spacer dispersion liquid, and liquid crystal display element

The present invention relates to a spacer for a liquid crystal display element that can prevent light leakage and generation of thread-like domains and can improve the display quality of the liquid crystal display element without disturbing the alignment of the liquid crystal. The present invention also relates to a liquid crystal display element spacer dispersion using the liquid crystal display element spacer and a liquid crystal display element.

The liquid crystal display element is configured by arranging liquid crystal between two glass substrates. In the liquid crystal display element, in order to keep the distance (gap) between two glass substrates uniform and constant, a spacer having a uniform particle diameter is used as a gap control material.

In the liquid crystal display element, as a result of the alignment of the liquid crystal molecules along the surface of the spacer at the interface between the liquid crystal and the spacer, the alignment of the liquid crystal molecules regulated by the alignment film may be irregular around the spacer. When such abnormal alignment of the liquid crystal molecules around the spacer occurs, a phenomenon called “light omission” that transmits light from the backlight occurs around the spacer. For this reason, the contrast of the liquid crystal display element may be lowered, or the display quality called “white spot” may be lowered. Such light leakage due to abnormal orientation occurs when a voltage is applied between the substrates. Even if the power of the liquid crystal display element is turned off after the voltage is applied, the light leakage phenomenon once generated is not solved.

As a spacer for preventing abnormal alignment of liquid crystal molecules around the spacer, for example, Patent Document 1 listed below discloses a spacer in which the surface of a microsphere is coated with an organosilane compound. In this spacer, the liquid crystal molecules are aligned perpendicular to the surface of the spacer by the organosilane compound present on the surface of the spacer. For this reason, abnormal orientation can be suppressed to some extent.

Further, Patent Document 2 below discloses a spacer in which a graft polymer chain having a long-chain alkyl group is introduced on the surface. Patent Document 2 describes that light leakage is prevented in a liquid crystal display element using a spacer according to an embodiment of the document.

JP-A-64-59212 JP-A-9-194842

In the spacer described in Patent Document 1, abnormal orientation may not be sufficiently suppressed depending on the combination of the material of the microsphere and the molecular structure of the organosilane compound.

In particular, in a STN (Super Twisted Nematic) type liquid crystal display element, even if there is little light leakage in the initial state and display performance is good, if external force is applied to the liquid crystal display element and the gap between the substrates changes, spacers and others There is a problem that the transmission of thread-like light called “thread-like domain” that connects the spacers in a straight line occurs.

On the other hand, even if the spacer described in Patent Document 2 is used, the occurrence of “filamentous domains” may not be sufficiently suppressed.

Further, in order to dispose the spacers on the substrate by wet spraying or an ink jet device, when a conventional spacer as described in

Patent Documents

1 and 2 is dispersed in a dispersion medium to obtain a spacer dispersion liquid, The dispersibility is low, and spacer aggregation may occur. For this reason, the aggregated spacer may be disposed on the substrate. Aggregated spacers are a factor that greatly deteriorates the quality of the liquid crystal display element.

An object of the present invention is to use a spacer for a liquid crystal display element that can prevent light leakage and occurrence of thread-like domains and can improve the display quality of the liquid crystal display element without disturbing the alignment of the liquid crystal, and the spacer for the liquid crystal display element The object is to provide a spacer dispersion for a liquid crystal display element and a liquid crystal display element.

Furthermore, the present invention provides a spacer for a liquid crystal display element in which the aggregation of the spacer hardly occurs when a spacer dispersion is obtained by dispersing in a dispersion medium, and a spacer dispersion for a liquid crystal display element using the spacer for a liquid crystal display element It is to provide a liquid and a liquid crystal display element.

According to a wide aspect of the present invention, it comprises a base particle and a resin layer disposed on the surface of the base particle, the resin layer comprising a compound having an alkyl group having 24 to 30 carbon atoms, an alkylene Provided is a spacer for a liquid crystal display element formed using a compound having an ether structure.

In a specific aspect of the spacer for a liquid crystal display element according to the present invention, the alkylene ether structure is a structure represented by the following formula (21A).

In the above formula (21A), R represents an alkylene group, and the alkylene group has 2 or more and 6 or less carbon atoms.

In another specific aspect of the spacer for a liquid crystal display element according to the present invention, the alkylene ether structure is an ethylene glycol structure.

In another specific aspect of the spacer for a liquid crystal display element according to the present invention, the resin layer contains 5 mol% or more and 30 mol% or less of a component derived from the compound having an alkyl group having 24 to 30 carbon atoms.

The liquid crystal display element spacer according to the present invention is preferably a liquid crystal display element spacer disposed on a substrate by a wet method or an ink jet apparatus. The spacer for a liquid crystal display element according to the present invention is preferably a liquid crystal display element spacer used for an STN type liquid crystal display element.

The spacer dispersion liquid for a liquid crystal display element according to the present invention includes a dispersion medium and a spacer for a liquid crystal display element that is dispersed in the dispersion medium and configured according to the present invention.

A liquid crystal display element according to the present invention includes a pair of substrates constituting a liquid crystal cell, a liquid crystal sealed between the pair of substrates, and a liquid crystal disposed between the pair of substrates and configured according to the present invention. And a display element spacer.

In the spacer for a liquid crystal display device according to the present invention, the resin layer disposed on the surface of the base particle is formed using a compound having an alkyl group having 24 to 30 carbon atoms and a compound having an alkylene ether structure. Therefore, it is possible to prevent light leakage and generation of thread-like domains and improve the display quality of the liquid crystal display element without disturbing the alignment of the liquid crystal.

FIG. 1 is a cross-sectional view showing a spacer for a liquid crystal display element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a liquid crystal display element using a liquid crystal display element spacer according to an embodiment of the present invention.

Hereinafter, the present invention will be clarified by describing specific embodiments and examples of the present invention with reference to the drawings.

FIG. 1 is a sectional view showing a spacer for a liquid crystal display element according to an embodiment of the present invention.

1 includes a base material particle 2 and a resin layer 3 disposed on the surface 2a of the base material particle 2. As shown in FIG. The resin layer 3 is formed using a compound having an alkyl group having 24 to 30 carbon atoms and a compound having an alkylene ether structure.

The liquid crystal display element spacer according to the present invention is suitably used as a liquid crystal display element spacer disposed on a substrate by a wet method or an inkjet apparatus. The spacer for a liquid crystal display element according to the present invention is suitably used for an STN type liquid crystal display element. However, the spacer for a liquid crystal display element according to the present invention may be used for a liquid crystal display element other than the STN type liquid crystal display element.

The present inventor has confirmed that the filamentous domain generated in the STN type liquid crystal display element is generated so as to connect the spacer and the other spacer with a straight line, and the filamentous domain further connects the spacer and the other spacer with a straight line. It was found that this occurs because the liquid crystal molecules are abnormally oriented so as to be tied. The reason why abnormal orientation called a thread domain occurs is considered as follows.

The liquid crystal display element usually has a liquid crystal cell in which liquid crystal is sealed between a pair of substrates arranged via a plurality of spacers. The liquid crystal display element is manufactured by attaching a polarizing plate or the like to the liquid crystal cell. At the stage of forming the liquid crystal cell, the liquid crystal molecules are aligned in the direction perpendicular to the surface of the spacer around the spacer, whereas the liquid crystal molecules are aligned according to the regulating force of the alignment film at a position away from the spacer. is doing. A polarizing plate or the like is attached to the liquid crystal cell while applying a pressing force with a roller or the like. Due to the pressing force applied at the time of pasting, a flow occurs in the aligned liquid crystal molecules according to the regulating force of the alignment film, and the alignment state is disturbed. The liquid crystal molecules that are sufficiently separated from the spacer return to a predetermined alignment state according to the regulating force of the alignment film when the pressing force from the roller or the like is removed. However, the liquid crystal molecules in the vicinity of the spacer are governed by the vertical alignment regulating force on the surface of the spacer, which is stronger than the regulating force of the alignment film, even if the pressing force from the roller or the like is removed. For this reason, it does not return to the predetermined alignment state according to the regulating force of the alignment film, and it seems that the spacer and other spacers are linearly connected while being aligned in an abnormal direction. Thus, it seems that the filamentous domain is generated by the strong vertical alignment regulating force on the surface of the spacer.

The present inventor uses the liquid crystal display element spacer in which the specific resin layer is disposed on the surface of the base particle, thereby causing abnormal alignment of the liquid crystal at the interface between the liquid crystal and the spacer and between the plurality of spacers. The present inventors have found that a liquid crystal display element having excellent display quality can be obtained because it becomes difficult to prevent light leakage and generation of thread domains. With the use of the spacer for a liquid crystal display element according to the present invention, even when an STN type liquid crystal display element is manufactured in particular, it is possible to effectively prevent the occurrence of light leakage and the generation of thread-like domains, and the liquid crystal sufficiently excellent in display quality. A display element can be obtained.

The spacer for a liquid crystal display element according to the present invention has base material particles and a resin layer disposed on the surface of the base material particles. The resin layer may be disposed on the entire region of the surface of the base particle, or may be disposed on a partial region. The resin layer preferably covers the surface of the base particle. The resin layer is preferably a coating resin layer. The resin layer is preferably attached to the surface of the base particle.

The material constituting the base particle is not particularly limited. The material constituting the substrate particles may be an inorganic material or an organic material.

Examples of the organic material include epoxy resins, phenol resins, melamine resins, unsaturated polyester resins, resins obtained by polymerizing polymerizable monomers having an ethylenically unsaturated group, divinylbenzene-polyester resins, divinylbenzene- Examples thereof include styrene resin, divinylbenzene-acrylate resin, and diacryl phthalate resin.

Examples of the inorganic material include silicate glass, borosilicate glass, lead glass, soda lime glass, alumina, and alumina silicate glass.

The substrate particle may be a substrate particle formed only from the organic material, or may be a substrate particle formed only from the inorganic material, and both the organic material and the inorganic material. The base material particle which has the composite structure formed by may be sufficient. Especially, it is preferable that the base particle is formed of an organic material. In this case, the spacer for the liquid crystal display element has an appropriate hardness that does not damage the alignment film formed on the substrate of the liquid crystal display element, and can easily follow a change in thickness due to thermal expansion or contraction. Become.

The preferable lower limit of the average particle diameter of the substrate particles is 1 μm, the preferable upper limit is 20 μm, and the more preferable upper limit is 10 μm. When the average particle diameter of the substrate particles is equal to or more than the above lower limit, the cell gap of the liquid crystal display element using the spacer is not too narrow, and a liquid crystal display element that is more excellent in display quality can be obtained. When the average particle diameter of the substrate particles is not more than the above upper limit, the cell gap of the liquid crystal display element using the spacer becomes even more uniform.

The average particle size of the substrate particles can be obtained by statistically processing the particle size measured using an optical microscope, an electron microscope, a coulter counter, or the like.

The CV value of the particle diameter of the substrate particles is preferably 10% or less. When the CV value of the particle diameter of the substrate particles is 10% or less, the cell gap of the liquid crystal display element using the spacer becomes more uniform, and the display quality is further improved.

The resin layer is formed using a compound having a long-chain alkyl group having 24 to 30 carbon atoms (hereinafter sometimes referred to as compound A). The resin layer includes a component derived from the compound A having a long-chain alkyl group having 24 to 30 carbon atoms. The component is a reaction product of Compound A having a long-chain alkyl group having 24 to 30 carbon atoms. The resin layer is preferably formed by reacting compound A having a long-chain alkyl group having 24 to 30 carbon atoms on the surface of the base particle. By using such compound A, a long-chain alkyl group having 24 to 30 carbon atoms can be introduced on the outer surface of the resin layer. Further, by using Compound A, a liquid crystal display element free from light leakage derived from a long-chain alkyl group having 24 to 30 carbon atoms can be obtained. In addition, when the liquid crystal display element spacer of the present invention is used in the manufacture of an STN type liquid crystal display element, the conventional surface-treated spacer has a pressing force that causes abnormal alignment, and a polarizing plate is applied by a roller or the like. Even when applied, for example, when the pressing force is removed, the liquid crystal molecules return to a predetermined alignment state in accordance with the regulating force of the alignment film, and it is difficult for the liquid crystal display element to form thread domains. By using the spacer for a liquid crystal display element of the present invention, even if a thread-like domain is generated, the original state without the thread-like domain can be obtained by performing treatment with ultrasonic waves or the like.

The carbon number of the long chain alkyl group is 24-30. When the carbon number of the alkyl group of the compound having a long-chain alkyl group is less than 24, light leakage occurs. A preferable lower limit of the carbon number of the long-chain alkyl group is 26. A compound having a long-chain alkyl group having 30 or less carbon atoms can be easily obtained. The compound A having a long-chain alkyl group having 24 to 30 carbon atoms is preferably a monomer, and more preferably a (meth) acrylate monomer. That is, the compound A is preferably a long chain alkyl group-containing monomer having 24 to 30 carbon atoms, and more preferably a long chain alkyl group-containing (meth) acrylate monomer having 24 to 30 carbon atoms. In particular, a long-chain alkyl group-containing monomer having 30 or less carbon atoms can be easily obtained. The compound A having a long chain alkyl group having 24 to 30 carbon atoms is preferably a compound having a long chain alkyl group having 24 to 30 carbon atoms and a (meth) acryloyl group. The said (meth) acrylate shows an acrylate and a methacrylate. The (meth) acryloyl group represents an acryloyl group and a methacryloyl group.

Examples of the long-chain alkyl group-containing monomer having 24 to 30 carbon atoms include tetracosyl (meth) acrylate having 24 alkyl atoms, pentacosyl (meth) acrylate having 25 carbon atoms, and 26 carbon atoms. Hexacosyl (meth) acrylate, heptacosyl (meth) acrylate having 27 carbon atoms, octacosyl (meth) acrylate having 28 carbon atoms, nonacosyl (meth) acrylate having 29 carbon atoms, and triacontyl having 30 carbon atoms (Meth) acrylate etc. are mentioned.

The preferable lower limit of the content of the component derived from the compound A having a long-chain alkyl group having 24 to 30 carbon atoms in the resin layer is 5 mol%, and the preferable upper limit is 30 mol%. When the content of the component derived from the compound A having a long-chain alkyl group having 24 to 30 carbon atoms is equal to or more than the above lower limit, light leakage is more difficult to occur. When the content of the compound A having a long-chain alkyl group having 24 to 30 carbon atoms is not more than the above upper limit, a thread domain is more difficult to occur.

In addition, in this specification, content of the component derived from the said compound A represents the preparation amount at the time of forming the said resin layer. That is, in order to form the resin layer, the preferable lower limit of the charged amount of the compound A is 5 mol%, and the preferable upper limit is 30 mol%.

The resin layer is formed using a compound having an alkylene ether structure (hereinafter sometimes referred to as compound B) together with a compound having an alkyl group having 24 to 30 carbon atoms. Compound B preferably has an alkylene glycol skeleton. The resin layer includes a component derived from the compound B having an alkylene ether structure. This component is a reaction product of Compound B having an alkylene ether structure. The resin layer is preferably formed by reacting compound B having an alkylene ether structure on the surface of the base particle. By using such compound B, an alkylene ether structure can be introduced on the outer surface of the resin layer. Furthermore, the use of compound B can effectively suppress aggregation of spacers for liquid crystal display elements in the dispersion medium due to the alkylene ether structure. In particular, aggregation of spacers for liquid crystal display elements can be significantly suppressed in a dispersion medium containing water.

That is, when the liquid crystal display element spacer in which the resin layer is formed using the compound A and the compound B is dispersed in the dispersion medium, the spacers can be hardly aggregated. For this reason, the spacer can be accurately arranged on the substrate by a wet method or an inkjet apparatus. In the spacer for a liquid crystal display element in which the resin layer is formed using the compound A and the compound B, the aggregation of the spacer in the dispersion liquid can be suppressed in the spacer dispersion liquid due to the alkylene ether structure of the compound B. In the liquid crystal, the above-mentioned effects can be obtained due to the alkyl group having 24 to 30 carbon atoms of the compound A, the light leakage and the generation of thread domains can be prevented, and the liquid crystal display element can be prevented without disturbing the alignment of the liquid crystal. Display quality can be improved. This is because the alkylene ether structure exhibits a relatively high hydrophilicity, and in the dispersion, the structure having a relatively high hydrophilicity affects, whereas the long-chain alkyl group having 24 to 30 carbon atoms has a high hydrophobicity, This is considered to be due to the influence of this highly hydrophobic group in the liquid crystal.

The alkylene ether structure is a structure represented by the following formula (21).

In the above formula (21), R represents an alkylene group. The alkylene group may be linear or have a branched structure. Carbon number of this alkylene group becomes like this. Preferably it is 2 or more, Preferably it is 6 or less, More preferably, it is 4 or less.

The alkylene ether structure is not particularly limited, and examples thereof include an ethylene glycol structure, a propylene glycol structure, a tetramethylene glycol structure, a pentamethylene glycol structure, and a hexamethylene glycol structure.

From the viewpoint of further suppressing the aggregation of the spacer for liquid crystal display element in the dispersion medium, the alkylene ether structure is preferably a structure represented by the following formula (21A).

In the above formula (21A), R represents an alkylene group, and the alkylene group has 2 or more and 6 or less carbon atoms. More preferably, the alkylene group has 4 or less carbon atoms. The alkylene group may be linear or have a branched structure.

From the viewpoint of further suppressing aggregation of the spacers for liquid crystal display elements in the dispersion medium, the alkylene ether structure is preferably an ethylene glycol structure, a propylene glycol structure, or a tetramethylene glycol structure. From the viewpoint of further suppressing the aggregation of the spacer for the liquid crystal display element in the dispersion medium, the alkylene ether structure is more preferably an ethylene glycol structure or a propylene glycol structure, and further preferably an ethylene glycol structure. . In order to suppress aggregation of the spacer for liquid crystal display element in the dispersion, the alkylene ether structure is preferably a propylene glycol structure or a tetramethylene glycol structure, preferably a propylene glycol structure, A methylene glycol structure is preferred. Compound B preferably has a polyalkylene ether structure, more preferably a polyethylene glycol structure, a polypropylene glycol structure or a polytetramethylene glycol structure, more preferably a polyethylene glycol structure or a polypropylene glycol structure, More preferably, it has a structure.

The preferable lower limit of the content of the component derived from the compound B having the alkylene ether structure in the resin layer is 0.1 mol%, and the preferable upper limit is 20 mol%. When the content of the component derived from the compound B is not less than the above lower limit, the aggregation of the spacers in the dispersion can be further suppressed. If the content of the compound B is not more than the above upper limit, light leakage and generation of thread domains can be further prevented, and the display quality of the liquid crystal display element can be further improved without disturbing the alignment of the liquid crystal.

In addition, in this specification, content of the component derived from the said compound B represents the preparation amount at the time of forming the said resin layer. That is, in order to form the resin layer, the preferable lower limit and the preferable upper limit of the charged amount of the compound B are the values described above.

Specific examples of the compound B having the alkylene ether structure include polyethylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate, polyethylene glycol polytetramethylene glycol monomethacrylate, polyethylene glycol polypropylene glycol monooctanol methacrylate, and the like.

The other compound constituting the resin layer is not particularly limited. For example, when hydrophilicity is imparted to the resin layer of the spacer for a liquid crystal display element, a compound having a hydroxyl group can be used. Examples of the compound having a hydroxyl group include hydroxyethyl (meth) acrylate and methoxypolyethylene glycol (meth) acrylate. When hydrophobicity is imparted to the resin layer of the spacer for liquid crystal display elements, alkyl (meth) acrylate, fluorine-containing (meth) acrylate, styrene derivatives such as styrene and p-chlorostyrene, glycidyl (meth) having a reactive site Acrylate, (meth) acrylic acid, (meth) acrylamide and the like can be used. Examples of the alkyl (meth) acrylate include butyl (meth) acrylate and stearyl (meth) acrylate. Examples of the fluorine-containing (meth) acrylate include trifluoroethyl (meth) acrylate and pentafluoropropyl (meth) acrylate. When it is desired to impart reactivity to the resin layer of the spacer for liquid crystal display elements, the above compound having a hydroxyl group, a compound having an epoxy group such as glycidyl (meth) acrylate, a monomer having a carboxyl group, or the like may be used. it can. As for these other compounds, only 1 type may be used and 2 or more types may be used together. Along with these monomers, other polymerizable monomers copolymerizable with the monomers may be used.

The thickness of the resin layer is appropriately determined in consideration of the particle diameter of the substrate particles, the type and composition of the material constituting the resin layer, and the like. The preferable lower limit of the thickness of the resin layer is 5 nm, and the preferable upper limit is 300 nm. When the thickness of the resin layer is 5 nm or more, the ability to prevent abnormal orientation is further enhanced, and light leakage is less likely to occur around the spacer in the liquid crystal display element. When the thickness of the resin layer is 300 nm or less, it is difficult for a plurality of spacers for liquid crystal display elements to be bonded to each other, and further, the resin layer is hardly deformed, so that the cell gap of the liquid crystal display element is made more uniform. can do. A more preferable lower limit of the resin layer is 10 nm, and a more preferable upper limit is 100 nm.

The resin layer may be disposed on the entire region of the surface of the substrate particle, or may be disposed only on a part of the region. Even when the resin layer is disposed only in a part of the region, compared to the case where the resin layer is not present, in the portion where the resin layer is present, light leakage and generation of thread domains are prevented, and the alignment of the liquid crystal is prevented. The display quality of the liquid crystal display element can be improved without being disturbed. When the resin layer is disposed only on a partial region of the surface of the base particle, the surface area of the base particle in which the resin layer is disposed in 100% of the total surface area of the base particle. A preferred lower limit of the proportion is 0.15%. When the ratio of the surface area on which the resin layer is disposed is 0.15% or more, light leakage can be sufficiently prevented and the effect of preventing the occurrence of thread domains is sufficiently exhibited.

As a method for producing the spacer for a liquid crystal display element of the present invention, for example, in the presence of a cerium-based catalyst such as ceric ammonium nitrate in the functional group on the surface of the base material particle, the length of 24 to 30 carbon atoms is used. A method of reacting compound A having a chain alkyl group (Ce method), and introducing a polymerizable functional group by reacting an isocyanate having a polymerizable functional group such as methacryloxyethyl isocyanate with the functional group on the surface of the base material particle. Thereafter, a method (polymerization method) of reacting the compound A having a long-chain alkyl group having 24 to 30 carbon atoms with the compound A may be used. In order to form the resin layer, the compound B may be reacted with the compound A, the compound B may be reacted after the reaction of the compound A, and the compound B is reacted before the reaction of the compound A. B may be reacted. In the resin layer, the compound A and the compound B may not be reacted, and the compound A and the compound B may be reacted.

For example, when polyvinyl alcohol is used as a dispersion aid when producing the base material particles using an organic material, the functional group on the surface of the base material particles is partially crosslinked with the organic material. It is entangled with the structure or adsorbed on the surface of the base particle. For this reason, polyvinyl alcohol exists on the surface of the substrate particles. The polyvinyl alcohol on the surface of the substrate particles is not removed even after the substrate particles are sufficiently washed while being heated. The spacer for a liquid crystal display element of the present invention can be produced by the Ce method or the polymerization method starting from a hydroxyl group derived from polyvinyl alcohol on the surface of the substrate particle. As the substrate particles, substrate particles having a hydroxyl group on the surface are preferably used.

When polyvinyl alcohol is not used when obtaining the base particles, an appropriate reactive functional group is introduced on the surface of the base particles, and starting from the reactive functional group, the Ce method or the polymerization method, The spacer for liquid crystal display elements of this invention can be manufactured.

The liquid crystal display element spacer according to the present invention is preferably a liquid crystal display element spacer disposed on a substrate by a wet method or an ink jet apparatus. In order to dispose the spacer on the substrate by a wet method or an ink jet apparatus, the liquid crystal display element spacer according to the present invention is preferably used by being dispersed in a dispersion medium. By dispersing the liquid crystal display element spacer in the dispersion medium, a liquid crystal display element spacer dispersion can be obtained.

The dispersion medium is not particularly limited. A conventionally known dispersion medium used for the spacer dispersion liquid can be used. Examples of the dispersion medium include isopropyl alcohol, water, methanol, and ethanol. The dispersion medium preferably contains water, preferably contains alcohol, and preferably contains water and alcohol. The alcohol is preferably isopropyl alcohol. As for the said dispersion medium, only 1 type may be used and 2 or more types may be used together.

The solid content concentration of the spacer in the spacer dispersion for the liquid crystal display element is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 10% by weight or less, more preferably 3% by weight or less. is there. When the solid content concentration is equal to or higher than the lower limit, an appropriate gap can be easily secured by a spacer in the liquid crystal display element. When the solid content concentration is less than or equal to the above upper limit, aggregates are further hardly generated in the spacer dispersion.

A liquid crystal display element according to the present invention includes a pair of substrates constituting a liquid crystal cell, a liquid crystal sealed between the pair of substrates, and the liquid crystal display element spacer disposed between the pair of substrates. The liquid crystal display element according to the present invention preferably includes a polarizing plate laminated on the outer surfaces of a pair of substrates. The liquid crystal display element according to the present invention is preferably an STN type liquid crystal display element.

FIG. 2 is a cross-sectional view of a liquid crystal display element using a liquid crystal display element spacer according to an embodiment of the present invention.

The liquid crystal display element 11 shown in FIG. 2 has a pair of transparent glass substrates 12. The transparent glass substrate 12 has an insulating film (not shown) on the opposing surface. Examples of the material for the insulating film include SiO ₂ . A transparent electrode 13 is formed on the insulating film in the transparent glass substrate 12. Examples of the material of the transparent electrode 13 include ITO. The transparent electrode 13 can be formed by patterning, for example, by photolithography. An alignment film 14 is formed on the transparent electrode 13 on the surface of the transparent glass substrate 12. Examples of the material of the alignment film 14 include polyimide.

A liquid crystal 15 is sealed between the pair of transparent glass substrates 12. A plurality of liquid crystal display element spacers 1 are arranged between the pair of transparent glass substrates 12. The distance between the pair of transparent glass substrates 12 is regulated by the plurality of liquid crystal display element spacers 1. A sealing agent 16 is disposed between the edges of the pair of transparent glass substrates 12. The sealing agent 16 prevents the liquid crystal 15 from flowing out.

In the liquid crystal display element, a preferable lower limit of the arrangement density of spacers for liquid crystal display elements per 1 mm ² is 10 pieces / mm ² , and a preferable upper limit is 1000 pieces / mm ² . When the arrangement density is 10 pieces / mm ² or more, the cell gap becomes even more uniform. When the arrangement density is 1000 / mm ² or less, the contrast of the liquid crystal display element is further improved.

The liquid crystal display element of the present invention can be manufactured by a conventionally known method except that the spacer for liquid crystal display element of the present invention is used.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited only to the following examples.

Example 1
(1) Preparation of substrate particle A 5 parts by weight of carbon black, 100 parts by weight of divinylbenzene and 2 parts by weight of benzoyl peroxide are added to 800 parts by weight of a 3% by weight aqueous polyvinyl alcohol solution, and the mixture is stirred with a homogenizer. The particle size was adjusted. Then, it heated up to 80 degreeC under nitrogen stream, stirring, and reacted for 15 hours, and obtained microparticles | fine-particles. The obtained fine particles were washed with hot ion-exchanged water and methanol, and then classified to obtain substrate particles A. The average particle diameter of the obtained base particle A was 6.0 μm, and the CV value was 5%.

(2) Production of spacer for liquid crystal display element To a separable flask, 100 g of the obtained base particle A, 220 g of N, N-dimethylformamide and 432 g of a (meth) acrylate monomer mixture were added and stirred.

The 432 g of (meth) acrylic acid ester monomer mixture used was 91 g (8 mol%) triacontyl methacrylate, 233 g (73 mol%) isobutyl methacrylate, 36 g (16 mol%) methyl methacrylate, and 72 g (3 mol%) methoxypolyethylene glycol monomethacrylate. ).

Next, nitrogen gas was introduced into the reaction system and stirred at 30 ° C. for 3 hours. Thereafter, 21 g of a 0.1 mol / L ceric ammonium nitrate solution prepared with a 1N aqueous nitric acid solution was added and reacted for 10 hours. After completion of the reaction, the obtained fine particles were washed with tetrahydrofuran and dried under reduced pressure in a vacuum dryer to obtain a liquid crystal display element spacer.

The average particle diameter of the obtained spacer for a liquid crystal display element was measured, and the thickness of the coating resin layer was determined from the difference from the average particle diameter of the base particle A. As a result, the thickness of the coating resin layer was 0.03 μm.

(Example 2)
The (meth) acrylic acid ester monomer mixed solution contains 241 g (30 mol%) triacontyl methacrylate, 115 g (51 mol%) isobutyl methacrylate, 25 g (16 mol%) methyl methacrylate, and 51 g (3 mol%) methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

(Example 3)
The (meth) acrylic acid ester monomer mixture liquid contains 317 g (50 mol%) triacontyl methacrylate, 55 g (31 mol%) isobutyl methacrylate, 20 g (16 mol%) methyl methacrylate, and 40 g (3 mol%) methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

Example 4
The (meth) acrylic acid ester monomer mixed solution contains 100 g (10 mol%) of hexacosyl methacrylate, 225 g (71 mol%) of isobutyl methacrylate, 36 g (16 mol%) of methyl methacrylate, and 71 g (3 mol%) of methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

(Example 5)
The (meth) acrylic acid ester monomer mixed solution contains 307 g (50 mol%) of hexacosyl methacrylate, 60 g (31 mol%) of isobutyl methacrylate, 22 g (16 mol%) of methyl methacrylate, and 44 g (3 mol%) of methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

(Example 6)
The (meth) acrylic acid ester monomer mixed solution contains 95 g (10 mol%) of tetracosyl methacrylate, 228 g (71 mol%) of isobutyl methacrylate, 36 g (16 mol%) of methyl methacrylate, and 72 g (3 mol%) of methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

(Example 7)
The (meth) acrylic acid ester monomer mixed solution contains tetracosyl methacrylate 301 g (50 mol%), isobutyl methacrylate 63 g (31 mol%), methyl methacrylate 23 g (16 mol%), and methoxypolyethylene glycol monomethacrylate 46 g (3 mol%). A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

(Example 8)
The (meth) acrylic acid ester monomer mixed liquid contains 181 g (30 mol%) of tetracosyl methacrylate, 104 g (51 mol%) of isobutyl methacrylate, 23 g (16 mol%) of methyl methacrylate, and 46 g (3 mol%) of methoxypolyethylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid mixture was changed.

Example 9
A (meth) acrylic acid ester monomer mixed solution containing 60 g (10 mol%) tetracosyl methacrylate, 104 g (71 mol%) isobutyl methacrylate, 23 g (16 mol%) methyl methacrylate, and 35 g (3 mol%) polypropylene glycol monomethacrylate A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid was changed.

(Example 10)
A (meth) acrylic acid ester monomer mixed liquid is mixed containing 24 g (30 mol%) triacontyl methacrylate, 104 g (51 mol%) isobutyl methacrylate, 23 g (16 mol%) methyl methacrylate, and 35 g (3 mol%) polypropylene glycol monomethacrylate. A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid was changed.

(Example 11)
The (meth) acrylic acid ester monomer mixture was mixed with 60 g (10 mol%) of tetracosyl methacrylate, 144 g (71 mol%) of isobutyl methacrylate, 23 g (16 mol%) of methyl methacrylate, and 37 g (3 mol%) of polypropylene glycol tetramethylene glycol monomethacrylate. A spacer for a liquid crystal display element was obtained in the same manner as in Example 1 except that the mixture was changed to a mixed solution containing.

(Example 12)
The (meth) acrylic acid ester monomer mixture was mixed with 241 g (30 mol%) of triacontyl methacrylate, 104 g (51 mol%) of isobutyl methacrylate, 26 g (16 mol%) of methyl methacrylate, and 37 g (3 mol%) of polypropylene glycol tetramethylene glycol monomethacrylate. A spacer for a liquid crystal display element was obtained in the same manner as in Example 1 except that the mixture was changed to a mixed solution containing.

(Comparative Example 1)
A (meth) acrylic acid ester monomer mixture solution containing 294 g (50 mol%) docosyl methacrylate, 66 g (31 mol%) isobutyl methacrylate, 24 g (16 mol%) methyl methacrylate, and 48 g (3 mol%) methoxypolyethylene glycol monomethacrylate A liquid crystal display element spacer was obtained in the same manner as in Example 1 except that the liquid was changed.

(Evaluation)
Using the spacers for liquid crystal display elements obtained in Examples and Comparative Examples, STN type liquid crystal display elements were produced, and light leakage, thread domains, and wet dispersibility were evaluated using the following evaluation methods.

(1) Manufacture of STN type liquid crystal display element In a dispersion medium containing 70 parts by weight of isopropyl alcohol and 30 parts by weight of water, the spacer concentration for liquid crystal display element is 2% by weight in 100% by weight of the obtained spacer dispersion. Was added and stirred to obtain a spacer dispersion liquid crystal display device.

An SiO ₂ film was deposited on one surface of a pair of transparent glass plates (length 50 mm, width 50 mm, thickness 0.4 mm) by a CVD method, and then an ITO film was formed on the entire surface of the SiO ₂ film by sputtering. A polyimide alignment film composition (SE3510, manufactured by Nissan Chemical Industries, Ltd.) was applied to the obtained glass substrate with an ITO film by spin coating, and baked at 280 ° C. for 90 minutes to form a polyimide alignment film. After the rubbing treatment for the alignment film, the liquid crystal display element spacers were wet-sprayed on the alignment film side of one substrate so that the number of spacers for a liquid crystal display element was 100 to 200 per 1 mm ² . After forming a sealant around the other substrate, this substrate and the substrate on which the spacers were spread were placed opposite to each other so that the rubbing direction was 90 °, and both were bonded together. Then, it processed at 160 degreeC for 90 minute (s), the sealing agent was hardened, and the empty cell (screen which does not contain a liquid crystal) was obtained. An STN type liquid crystal containing a chiral agent (made by DIC) was injected into the obtained empty cell, and then the injection port was closed with a sealant, followed by heat treatment at 120 ° C. for 30 minutes to produce an STN type liquid crystal display element. Obtained.

(2) Evaluation of light leakage The obtained STN type liquid crystal display element was sandwiched between polarizing films arranged to be in a normally black display mode, and voltages of 7V, 17V, 30V and 50V were applied. Then, the photograph expanded 200 times with the microscope was taken, and the state of light omission (alignment state of liquid crystal) was observed. As a result, “◎” indicates that there is no abnormal alignment of the liquid crystal around the spacer, “○” indicates that abnormal alignment of the liquid crystal is observed in a very small portion around the spacer, and abnormal liquid crystal appears on the entire periphery of the spacer. The case where the occurrence of orientation was observed was evaluated as “x”.

(3) Evaluation of thread-like domain A roller with silicon rubber attached was attached to a push-pull gauge, and the push-pull gauge was fixed to a stand so that the roller rotation direction was horizontal with respect to the ground. This push-pull gauge can be moved in a direction perpendicular to the ground. A slide-type stage was placed under the roller so that the STN type liquid crystal display element could be fixed. The STN type liquid crystal display element was placed on the slide type stage, the fixed push-pull gauge was moved downward, and pressure was applied to the STN type liquid crystal display element. After sliding the STN type liquid crystal display element pressed with a roller, the presence or absence of the occurrence of thread domains in the panel was confirmed with a polarizing microscope at a magnification of 100 times. The pressure applied to the STN type liquid crystal display element was gradually increased, and the pressure when the filamentous domain was generated (filamentous domain generation pressure, N) was measured.

(4) Evaluation of wet sprayability In a dispersion medium containing 70 parts by weight of isopropyl alcohol and 30 parts by weight of water, the solid content concentration of the spacer for liquid crystal display element is 2% by weight in 100% by weight of the obtained spacer dispersion. Were added as described above and stirred to obtain a spacer dispersion liquid crystal display device. The liquid crystal display element spacers after standing for 12 hours were wet-sprayed onto a glass substrate having an area of 450 cm ² at a spraying density of 150 pieces / mm ² , and the liquid crystal display element spacers were adhered to the glass substrate. Thereafter, the number of lumps in which three, four and five or more spacers aggregated per 6.3 mm ² was counted.

(5) Time-of-flight secondary ion mass spectrometry TOF-SIMS analysis Time-of-flight secondary ion mass spectrometry TOF-SIMS (TOF-SIMS type 5 manufactured by ION-TOF) for all polymers on the surface of spacers for liquid crystal display elements The spectral intensity ratio of the long chain alkyl polymer was measured. Analyzes and introduces negatively charged ionic long-chain alkyl polymer, isobutyl methacrylate polymer, methyl methacrylate polymer, methoxy polyethylene glycol monomethacrylate polymer, polypropylene glycol monomethacrylate polymer and polypropylene glycol tetramethylene glycol monomethacrylate polymer by TOF-SIMS The rate was measured.

The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Spacer for liquid crystal display elements 2 ... Base material particle 2a ... Surface 3 ... Resin layer 11 ... Liquid crystal display element 12 ... Transparent glass substrate 13 ... Transparent electrode 14 ... Orientation film 15 ... Liquid crystal 16 ... Sealing agent

Claims

Substrate particles,
A resin layer disposed on the surface of the substrate particles,
The spacer for a liquid crystal display element, wherein the resin layer is formed using a compound having an alkyl group having 24 to 30 carbon atoms and a compound having an alkylene ether structure.
The spacer for liquid crystal display elements according to claim 1, wherein the alkylene ether structure is a structure represented by the following formula (21A).

In the formula (21A), R represents an alkylene group, and the alkylene group has 2 or more and 6 or less carbon atoms.
The liquid crystal display element spacer according to claim 2, wherein the alkylene ether structure is an ethylene glycol structure.
4. The spacer for a liquid crystal display element according to claim 1, wherein the resin layer contains 5 mol% or more and 30 mol% or less of a component derived from the compound having an alkyl group having 24 to 30 carbon atoms.
The liquid crystal display element spacer according to any one of claims 1 to 4, which is a liquid crystal display element spacer disposed on a substrate by a wet method or an inkjet apparatus.
The liquid crystal display element spacer according to any one of claims 1 to 5, which is a liquid crystal display element spacer used in an STN type liquid crystal display element.
A dispersion medium;
A spacer dispersion liquid for a liquid crystal display element, comprising the liquid crystal display element spacer according to any one of claims 1 to 6 dispersed in the dispersion medium.
A pair of substrates constituting a liquid crystal cell;
Liquid crystal sealed between the pair of substrates;
A liquid crystal display element comprising: the liquid crystal display element spacer according to claim 1 disposed between the pair of substrates.