KR100511194B1 - Capsulized or Surface Functionalized Monodisperse Polymer Particle and Method of Preparing the Same - Google Patents

Abstract

The encapsulated or surface functionalized monodisperse polymer microparticles (5) according to the present invention may be prepared by dispersing polymer microparticles having a full-interpenetrating polymer network structure in an aqueous solution in which an oxidation-reduction initiator, an acid, and an emulsifier are dissolved together. Dispersing to prepare a polymer dispersion (1); Dispersion 2 is separately prepared by mixing and stirring an organic solvent in which a monomer, an initiator and a crosslinking agent are dissolved, and an aqueous solution in which a dispersion stabilizer is dissolved; The mixed and stirred dispersion (2) is again mixed and stirred with the polymer dispersion (1) to prepare a polymer dispersion (3) collected by the mixed and stirred dispersion; Depositing and polymerizing the collected polymer dispersion (3) to form a deposition layer on the surface of the polymer dispersion to produce a surface functionalized polymer dispersion (4); And it is characterized in that the step of removing the organic solvent on the surface functionalized polymer dispersion (4), it can be used as a spacer for a liquid crystal display (LCD).

Description

Encapsulated or Surface Functionalized Monodisperse Polymer Particle and Method of Preparing the Same

Field of invention

The present invention relates to encapsulated or surface functionalized monodisperse polymer fine particles and a method for producing the same. More specifically, the present invention relates to an encapsulated or surface functionalized monodisperse polymer fine particle produced by dispersing and depositing polymer fine particle having a full interpenetrating polymer network (Full-IPN) structure and a method of manufacturing the same.

Background of the Invention

In the currently widely applied liquid crystal display device, when the thickness of the liquid crystal layer is not constant, the image displayed on the liquid crystal cell causes a color shade and the contrast ratio during illumination decreases, It is very important to keep the thickness constant. Moreover, in order to prevent color shading when displaying a large image, a wide range of supertwisted nematic (STN) mode liquid crystal display devices have recently been adopted, in which the thickness of the liquid crystal layer in the liquid crystal cell must be highly constant.

In order to keep the thickness of the liquid crystal cell constant, a spacer of spherical organic or inorganic material is injected into the liquid crystal cell to maintain a cell gap. However, the organic material spacer has the characteristics of an impurity in itself, and thus deteriorates the display characteristics of the liquid crystal display due to the following reasons.

1. Mobility in Spacer Cells

2. Abnormal orientation of liquid crystal by interaction between spacer and peripheral liquid crystal

The organic particulate spacers in the form of spherical particulates are moved within the cell by external stresses, thereby degrading the display quality of the display, which is the biggest cause of deterioration of display characteristics. Furthermore, the liquid crystals around the spacers are abnormally oriented by the interaction of the liquid crystal spacers with the spherical particulate form and the liquid crystals, resulting in a light leakage and a decrease in the contrast ratio of the display.

Therefore, the present inventors encapsulate or surface functionalize the polymer fine particles having a fully-IPN structure that satisfies the basic properties such as compressive modulus, compressive strain, recovery rate, and monodispersity in order to overcome the problems of the prior art. By doing so, it is possible to produce encapsulated or surface-functionalized hard monodisperse polymer microparticles which can significantly increase the adhesion in the liquid crystal cell and the liquid crystal alignment anchoring force.

An object of the present invention is to provide an encapsulated or surface functionalized monodisperse polymer fine particle that can be used in a high definition and large screen liquid crystal display spacer.

Another object of the present invention is to provide an encapsulated or surface functionalized monodisperse polymer fine particle having excellent scattering property and liquid crystal alignment regulating force.

Still another object of the present invention is to provide an encapsulated or surface functionalized monodisperse polymer fine particle having excellent adhesion in a hot-melt manner.

Still another object of the present invention is to provide an encapsulated or surface functionalized hard monodisperse polymer fine particle capable of variously designing the surface functional layer depending on the type and content of the surface functional layer introducing monomer.

It is another object of the present invention to provide a method for preparing encapsulated or surface functionalized monodisperse polymer fine particles prepared by implementing a continuous metal / polymer layer on the surface of a polymer particle having a fully-interpenetrating polymer network (IPN) structure. It is for.

The above and other objects of the present invention can be achieved by the present invention described in detail.

Summary of the Invention

The encapsulated or surface functionalized monodisperse polymer microparticles (5) according to the present invention may be prepared by dispersing polymer microparticles having a full-interpenetrating polymer network structure in an aqueous solution in which an oxidation-reduction initiator, an acid, and an emulsifier are dissolved together. Dispersing to prepare a polymer dispersion (1); Dispersion 2 is separately prepared by mixing and stirring an organic solvent in which a monomer, an initiator and a crosslinking agent are dissolved, and an aqueous solution in which a dispersion stabilizer is dissolved; The mixed and stirred dispersion (2) is again mixed and stirred with the polymer dispersion (1) to prepare a polymer dispersion (3) collected by the mixed and stirred dispersion; Depositing and polymerizing the collected polymer dispersion (3) to form a deposition layer on the surface of the polymer dispersion to produce a surface functionalized polymer dispersion (4); And removing the organic solvent on the surface functionalized polymer dispersion (4).

Polymeric fine particles having a full interpenetrating crosslinking (Full-IPN) structure according to the present invention is a long-chain crosslinking agent, a monomer, an oil-soluble initiator, and a dispersion stabilizer is dissolved in alcohol, dispersed and polymerized, and then washed and dried to form a crosslinked seed. To produce particles; Dispersing the crosslinked seed particles into an aqueous solution in which an emulsifier is dissolved to prepare a seed dispersion; A second crosslinking monomer in which an oil-soluble initiator is dissolved is separately emulsified in an aqueous solution in which an emulsifier is dissolved, and then added to the seed dispersion to swell to prepare a polymer dispersion; And polymerizing the polymer dispersion by stabilizing the dispersion using a dispersion stabilizer, followed by washing and drying.

The encapsulated or surface functionalized hard monodisperse polymer fine particles according to the present invention can be used as a spacer for a liquid crystal display (LCD).

Detailed Description of the Invention

The encapsulated or surface-functionalized hard monodisperse polymer microparticles 5 according to the present invention are based on polymer microparticles having a fully-IPN structure, which encapsulates or surface functionalizes the polymer microparticles having a fully-IPN structure. In addition to the emulsifier, the redox initiator and the acid are dispersed in an aqueous solution added together. Polymeric fine particles having a fully-IPN structure prepared according to the present invention is easy to control the particle size, surface functional groups can be easily introduced, and also mechanical properties including heat resistance, that is, compressive modulus, compressive strain, recovery rate, and single fraction Since it is excellent in basic physical properties such as acidic, when based on this, the encapsulated or surface-functionalized monodisperse polymer fine particles excellent in the dispersibility, adhesion, and liquid crystal alignment control force can be produced.

The manufacturing method of the polymer microparticles | fine-particles which have the said fully-IPN structure is as follows.

Preparation of Polymer Fine Particles with Fully-IPN Structure

(1) Preparation of Crosslinked Seed Particles

The long-chain crosslinking agent, the monomer, the oil-soluble initiator, and the dispersion stabilizer are dissolved in alcohol, dispersed and polymerized, followed by washing and drying to prepare cross-linked seed particles. At this time, it is washed and dried by centrifugation.

The long-chain crosslinking agent may include a polyoxyethyleneglycol-base, a polyoxypropyleneglycol-base, and a polytetramethyleneglycol having a molecular weight (M _w ) in the range of about 500 to 10,000. It is also possible to introduce a crosslinking agent of a vinyl-terminated or acrylate-terminated crosslinking agent such as -base, and a reactive crosslinking agent such as epoxy acrylate or urethane acrylate. At this time, it is possible to design the physical properties according to the content and diversification of the crosslinking agent, and also to design the molecular structure according to the selection of the reaction continuous phase and other polymerization parameters.

The monomer is a monomer capable of radical polymerization, specifically styrene, p- or m-methylstyrene, p- or m-ethylstyrene, p- or m-chlorostyrene, p- or m-chloromethylstyrene, styrenesulfonic acid , p- or m-t-butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl ( Meth) acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate Vinyl acetate, vinyl prop They include acrylonitrile, carbonate, vinyl butyrate, vinyl ether, allyl butyl ether, allyl glycidyl naphthyl ether, (meth) unsaturated carboxylic acids, alkyl (meth) containing acrylic acid or maleic acid acrylamide, and (meth) acrylate. Depending on the type of monomer selected, the form of the particles produced by the two-step swelling method is determined.

The initiator is a conventional oil-soluble initiator commonly used, specifically benzoyl peroxide, lauryl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, t-butylperoxy-2-ethylhexa Peroxide compounds including noate, t-butyl peroxyisobutyrate, 1,1,3-3-tetramethylbutylperoxy-2-ethylhexanoate, dioctanoyl peroxide, and didecanoyl peroxide And azo compounds comprising 2,2'-azobisiobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), and 2,2'-azobis (2.4-dimethylvaleronitrile). It includes.

The dispersion stabilizer is a polymer that can be dissolved in an alcohol phase or an aqueous phase, and specifically, gelatin, starch, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl alkyl ether, polyvinyl alcohol, poly Dimethylsiloxane / polystyrene block copolymers and the like. The polymer particles produced during the dispersion polymerization are used in an amount sufficient to suppress deposition by gravity or aggregation between particles, and it is preferable to use at least about 1.5% by weight based on the total reactants.

The alcohol is a continuous phase, specifically methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butanol and the like, and distilled water or benzene, toluene, xylene, methoxyethanol to control the dissolving power of the continuous phase Organic materials such as these may be used in combination with the alcohol.

(2) redispersion of crosslinked seed particles

The cross-linked seed particles thus prepared are redispersed in ultrasonic waves in a second aqueous solution in which 0.1 to 0.5% of an emulsifier is dissolved to prepare a seed dispersion.

The emulsifiers used are basically preferred anionic emulsifiers. Specifically, alkyl, aryl, alkali sulfate, sulfonate, phosphate, or succinate and the like and ethoxy derivatives thereof are included.

The emulsifiers also include nonionic emulsifiers such as polyoxyethylene alkyl ethers having a molecular weight of 500 to 10,000, polyoxyethylene alkyl phenol ethers, and polyethylene glycols. Further, a long-chain nonionic emulsifier containing a hydroxyl group and a reactive vinyl group such as a polyethylene oxide, a polypropylene oxide having a molecular weight of 500 to 10,000, and a copolymer of polyethylene oxide-pullypropylene oxide-polyethylene oxide is included. can do. Suitable use of one or more of the above emulsifiers can be easily carried out by those skilled in the art. It is preferable to use it in the quantity of 0.1 to 0.5% with respect to the whole dispersion composition.

(3) Introduction of Secondary Crosslinking Monomer

The second crosslinking monomer in which the oil-soluble initiator is dissolved is separately emulsified in a third aqueous solution containing 0.1 to 0.5% of an emulsifier using a mechanical stirrer for 10 to 30 minutes, and then added to the prepared seed dispersion and swelled to disperse the polymer. Prepare a sieve. At this time, the particle size can be easily adjusted through appropriate control of the swelling ratio.

The secondary crosslinking monomer is capable of radical polymerization, and specifically, divinylbenzene, 1,4-divinyloxybutane, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, Allyl compounds such as trially trimellitate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerylyl Tritol tri (meth) acrylate, pentaaryl tritol di (de) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol Acrylic compounds, such as penta (meth) acrylate and glycerol tri (meth) acrylate, etc. are contained.

As the emulsifier used for preparing the oil-soluble initiator and the monomer emulsion dissolved in the secondary crosslinking monomer, initiators and emulsifiers of the same kind as described above are used. At this time, the emulsifier also serves to suppress the deposition and aggregation of the particles together with the dispersion stabilizer in the polymerization process. In addition, it is preferable to use an emulsifier in the amount of 0.1-0.5% with respect to the whole dispersion composition at the time of preparing a monomer emulsion.

(4) Preparation of Polymer Particles of Fully-IPN Structure

The swollen polymer dispersion is stabilized using a dispersion stabilizer and polymerized for 10 to 24 hours, followed by washing and drying to prepare polymer fine particles having a fully-IPN structure.

As the dispersion stabilizer, a dispersion stabilizer of the same kind as described above is used, and it is preferable that the dispersion stabilizer is used in an amount of about 1.0% by weight based on the total reactants.

Polymeric fine particles having a fully-IPN structure prepared by the above method can control the swelling ratio during manufacture to vary the particle size, surface functional groups can be easily introduced, and excellent heat resistance and mechanical properties. Furthermore, by implementing a continuous metal / polymer layer on the surface of the particles, the present invention can be applied as a substrate of conductive fine particles, which is an essential material of the anisotropic conductive film.

Encapsulated or surface-functionalized hard monodisperse polymer microparticles (5) were prepared using polymer microparticles having a fully-IPN structure.

Hard monodisperse polymer microparticles (5) encapsulated or surface functionalized are prepared using polymer microparticles having a fully-IPN structure prepared by the above method.

A polymer dispersion (1) is prepared by re-dispersing the polymer fine particles (5) having a fully interpenetrating crosslinked structure using ultrasonic waves in an aqueous solution in which not only an emulsifier but also an oxidation-reduction initiator and an acid catalyst are dissolved together.

After mixing and stirring an organic solvent in which a monomer, an initiator, and a crosslinking agent are dissolved, and an aqueous solution in which a dispersion stabilizer is dissolved, a dispersion (2) is separately prepared, and then the mixed and stirred dispersion (2) is prepared as the polymer dispersion ( It is mixed and stirred again with 1) to prepare a polymer dispersion 3 collected by the mixed and stirred dispersion. That is, after dissolving the monomer for the polymer to be encapsulated or introduced into the shell in an organic solvent with an initiator, the dispersion (2) is prepared by mechanical stirring at 3,000 to 5,000 rpm in an aqueous solution in which the dispersion stabilizer is dissolved. It is. In addition, the dispersion 2 is mixed with the polymer dispersion 1 and then stirred for 24 hours to produce a polymer dispersion 3 which is in a metastable state and collected by an organic solvent.

A temperature of about 25-45 ° C. is applied to the collected polymer dispersion to proceed with deposition polymerization. In this way, the monomers dissolved in the organic solvent are polymerized and a deposit layer is formed on the surface of the polymer dispersion 1 to produce the surface functionalized polymer dispersion 4.

When the deposition layer is described in more detail, the organic solvent to be introduced has a very low solubility in the resulting polymer, and thus rapidly forms a nucleus above a certain degree of polymerization. These rapidly formed nuclei do not have their own stabilization substrate, causing agglomeration, which occurs at the surface of particles trapped in an organic solvent. The growth reaction also proceeds very quickly, a gel-effect which is one of the phenomena commonly seen in deposition polymerization. Basically, in order to chemically stabilize the deposited layer, a certain amount of crosslinking agent should be introduced at the time of monomer selection.

The organic solvent on the surface functionalized polymer dispersion is removed by a method such as evaporation to prepare encapsulated or surface functionalized hard monodisperse polymer fine particles (5).

The emulsifier is the same as the emulsifier used when preparing the polymer fine particles having the fully interpenetrating crosslinked structure described above. These emulsifiers also, along with the dispersion stabilizers during polymerization, inhibit the deposition and aggregation of the particles. Appropriate content is suitably 0.1 to 0.5% of the total dispersion composition. However, any stabilizer may be used in addition to these nonionic surfactants, which can be easily carried out by those skilled in the art.

In the present invention, not only an emulsifier but also an oxidation-reduction initiator and an acid catalyst are added. Specifically, redox initiators include Cerium sulfate, Ceric ammonium sulfate, Ceric ammonium nitrate, and Ceric perchlorate, and acid catalysts include sulfuric acid and nitric acid.

Monomers used to introduce the shell or surface functional layer include styrene, p- or m-methylstyrene, p- or m-ethylstyrene, p- or m-chlorostyrene, p- or m-chloromethylstyrene, styrenesulfonic acid, p- or m-t-butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t -Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth ) Acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, Vinyl acetate, vinyl propionate, non Nyl butyrate, vinyl ether, allyl butyl ether, allyl glycidyl ether, unsaturated carboxylic acids including (meth) acrylic acid or maleic acid, and alkyl (meth) acrylamide, (meth) acrylonitrile and the like. Furthermore, cyclic vinyl derivatives including dicyclopentadiene, methylene norbornene, and camphor can also be used.

Crosslinking agents used for crosslinking of the shell or surface functional layer are divinylbenzene, 1,4-divinyloxybutane, divinylsulphone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, and tri Allyl compound including allyl trimellitate and (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythryl Tall tri (meth) acrylate, pentaaryl tritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta And acrylic compounds containing (meth) acrylate and glycerol tri (meth) acrylate.

Organic solvents used for surface functionalization are preferably hydrocarbons such as n-nucleic acid, cyclonucleic acid, n-heptane, iso-octane, but are not limited thereto.

Initiators used for surface functionalization are conventional oil-soluble initiators, specifically benzoyl peroxide, lauryl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, t-butylperoxy-2- Peroxides including ethylhexanoate, t-butyl peroxyisobutyrate, 1,1,3-3-tetramethylbutylperoxy-2-ethylhexanoate, dioctanoyl peroxide, and didecanoyl peroxide A system compound and 2,2'-azobisiobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), and 2,2'-azobis (2.4-dimethylvaleronitrile) Azo compounds and the like.

 Dispersion stabilizers used for polymer dispersions (3) collected by organic solvents are polymers that can be dissolved in an alcoholic or aqueous solution, or a mixture of the two solvents, specifically gelatin, starch, hydroxy. Ethyl cellulose, carboxymethyl cellulose-rose, polyvinylpyrrolidone, polyvinyl alkyl ether, polyvinyl alcohol, polydimethylsiloxane / polystyrene block copolymer, and the like are used. Approximately 1 to 10%, which can be suppressed, is appropriate.

The encapsulated or surface functionalized monodisperse polymer microparticles according to the present invention have a high elastic strain and a compressive strain, a low statistical dispersion of the compressive strain, and excellent dispersion. In addition, since the adhesion is excellent in the hot-melt method in the liquid crystal cell, and there is no interaction with the liquid crystal, no abnormal alignment occurs around the spacer, and thus the liquid crystal alignment regulating force is excellent, thereby showing very excellent display quality. Therefore, it can be used as a spacer for a liquid crystal display device of high quality and large screen.

When the encapsulated or surface functionalized hard monodisperse polymer fine particles according to the present invention are used as the spacer, the 10% compressive modulus of the spacer is 150 to 900 Kg / mm ² , preferably 200 to 700 Kg / mm ² . If the 10% compressive modulus is less than 150 Kg / mm ² , the particles become soft, and thus, the thickness of the liquid crystal layer cannot be maintained uniformly inside the liquid crystal cell, and if it is 900 Kg / mm ² or more, cold bubbling may occur. . At this time, the statistical dispersion of the 10% compression modulus is in the range of ± 20%, preferably ± 15% of the mean value. As the range of statistical dispersion becomes wider, the degree of deformation due to pressure is different between the individual particles, which results in cold bubbling in the final display, color shading, or lower contrast ratio. A problem arises.

The liquid crystal display device has a liquid crystal cell attached to a pair of electrodes, in which the encapsulated or surface functionalized hard monodisperse polymer fine particles according to the present invention can be positioned as spacers. The liquid crystal cell is the same as the conventional one except that the spacer according to the present invention is distributed so that the distance between the electrodes of the liquid crystal cell is kept constant.

As shown in FIG. 2, the encapsulated or surface functionalized hard monodisperse polymer fine particles are dispersed and fixed in the liquid crystal alignment film 6 of the liquid crystal cell. At this time, in the hard monodisperse polymer fine particles encapsulated or surface functionalized, the functional layer 5B encapsulated or surface functionalized in the base resin fine particles 5A is partially melted by heating or pressurization, and the liquid crystal aligning film 6 Flows down and sticks. This is called a hot-melt spacer.

In the case of using the encapsulated or surface-functionalized hard monodisperse polymer fine particles according to the present invention as the spacer, the compression deformation is larger than that of the conventional spacer, and thus the disproportionation of the liquid crystal cell thickness does not occur, and the coefficient of thermal expansion of the liquid crystal layer and the spacer Due to the difference in the coefficient of thermal expansion, cold bubbling generated inside the liquid crystal cell is lowered, and the mobility in the cells of the fine particles is lowered, so that the display characteristics of the final liquid crystal display device are excellent. In addition, according to the cell gap that is usually required, it is possible to produce a corresponding polymer fine particles, it is possible to control the diameter and coefficient of variation (CV).

When manufacturing a liquid crystal display cell using the encapsulated or surface-functionalized hard monodisperse polymer fine particles according to the present invention as an interelectrode spacer of a liquid crystal cell, the spacer is uniformly applied to the electrode surface of one panel by a wet or dry method. Scatter, stack panels in different directions and apply pressure. At this time, a uniform fine gap is formed between the cells, and the liquid crystal material is filled in the cell gap.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1A

(1) Preparation of Crosslinked Seed Particles

Ethanol mixed with a styrene monomer, a long chain crosslinking agent, 1.0 g of azobisisobutyronitrile as a fat-soluble initiator, 17.9 g of polyvinylpyrrolidone K-30 having a molecular weight of 40,000 as a dispersion stabilizer, and a 1: 1 weight ratio as a solvent; 877.7 g of methoxyethanol were mixed and stirred to dissolve completely. At this time, the total amount of the monomer was adjusted to 100.0 g, but a polydimethylsiloxane-based crosslinking agent having a molecular weight (Mw) of about 1,000 was fixed at 15.0% based on the content of the styrene monomer. Then, the polymerization was carried out under a nitrogen atmosphere at a stirring speed of 40 rpm for 24 hours at 70 ° C. The prepared polystyrene crosslinked particles were removed using an centrifuge to remove unreacted materials and dispersion stabilizers and then dried in a vacuum oven for 24 hours to obtain particles in the form of powder.

(2) redispersion of crosslinked seed particles

1.0 g of the cross-linked polystyrene seed particles prepared above was irradiated for 10 minutes with 100.0 g of a 0.25% poly (ethylene oxide-propylene oxide-ethylene oxide) monoacrylate aqueous solution and redispersed in a glass reactor to prepare a seed dispersion. It was.

(3) Introduction of Secondary Crosslinking Monomer

After divinylbenzene monomer having benzoyl peroxide initiator dissolved in 200.0 g of poly (ethylene oxide-propylene oxide-ethylene oxide) monoacrylate solution was emulsified for 10 minutes by ultrasonic irradiation and mechanical stirring at 20,000 rpm. To the prepared seed dispersion was added dropwise and swollen at room temperature for 24 hours. At this time, the monomer swelling ratio was fixed at 70 times the weight ratio with respect to the seed particles.

(4) Preparation of Polymer Particles of Completely Interpenetrating Structure

After confirming that the swelling of the monomer is finished, the total content was adjusted to 400.0 g using an aqueous solution in which 10.0 g of polyvinyl alcohol having about 88% saponification was dissolved. The temperature of the reactor was then raised to 80 ° C. and polymerized under nitrogen atmosphere for 10 hours. Thus, the polydivinylbenzene particles prepared by the two-step swelling method were repeatedly removed by the centrifugal separator and the dispersion stabilizer, and dried in a vacuum oven for 24 hours to obtain particles in the form of powder.

(5) Preparation of Encapsulated or Surface Functionalized Polymer Fine Particles

10.0 g of polydivinylbenzene particles, the polymer fine particles having the fully interpenetrating crosslinked structure, were dispersed in a glass reactor by irradiating 300.0 g of an aqueous solution in which 0.05 mole of Ceric ammonium culfate was dissolved for 30 minutes. Subsequently, 1.0 g of methyl methacrylate, 7.0 g of butyl methacrylate, and 2.0 g of lauryl methacrylate were mixed, and then the mixture was mixed with 200 g of 10% aqueous polyvinylpyrrolidone (PVP) solution at about 4,000 rpm. It was stirred and dispersed. The dispersion was stirred with the redispersed dispersion at 300 rpm for 24 hours, and then heated to 32.5 ° C to polymerize for 8 hours. The prepared encapsulated particles were repeatedly removed by removing the unreacted material and the dispersion stabilizer using a centrifuge, and dried in a vacuum oven for 24 hours to prepare a powder.

Example 1B

The same procedure as in Example 1A was conducted except that 30.0 g of polydivinylbenzene particles were used as the polymer fine particles having a fully interpenetrating crosslinked structure.

The particle size and particle size dispersion index of the encapsulated or surface functionalized monodisperse polymer microparticles prepared in Examples 1A to 1B were measured using an optical microscope and a scanning electron microscope photograph. In addition, the thickness of the shell part was measured using the transmission electron microscope. The results are shown in Table 1 below.

Average particle size (㎛) Particle size distribution index Thickness of the shell (nm) Example 1A 6.25 1.010 0.425 Example 1B 5.49 1.002 0.145

As shown in Table 1, it can be seen that it is very easy to control the thickness of the shell through the control of the polymerization parameters. It can also be seen that the encapsulated or surface functionalized polymer microparticles according to the invention are monodisperse.

In order to evaluate the dispersibility of the encapsulated or surface-functionalized monodisperse polymer prepared in Examples 1A to 1B as a spacer, the polymer fine particles were subjected to a pressure of 2.5 kgf / cm ² and a feed rate of 1.0 rpm at a distance of 150 mm from the substrate. 50 scatters were performed for 10 seconds, and 5 or more aggregated particles were visually counted using optical microscopy. As a result, the aggregation rate was less than 1%. Therefore, it turns out that the dispersion property as a spacer is excellent.

In addition, the spacers prepared in Examples 1A to 1B were heated at 120 ° C. for 10 minutes in dispersion and hot-stage, followed by air at a pressure of 2 kg / cm ² through a nozzle having a particle diameter of 2 mm at a distance of 5 mm from the substrate. In the case of -blowing, the residual rate was 95%. Therefore, it can be seen that the adhesion of the spacer is excellent.

Examples 2A-2B

In a mixed solvent of 350 mL of pure water, 120 mL of isopropyl alcohol, and 30 mL of ethyl alcohol, the monodisperse polymer fine particles prepared in Examples 1A to 1B were stirred at a concentration of 1% by weight, followed by ultrasonic irradiation. Was prepared. The dispersion liquid was sprayed at a pressure of 3 Kg / cm 2 with a distance of 70 cm from the nozzle and the alignment film surface using a dispersion nozzle with a nozzle diameter of 0.5 mm Φ, and dispersed on the alignment film surface formed on the transparent electrode and the transparent substrate.

A glass substrate was used as the transparent substrate used in the liquid crystal cell of the liquid crystal display device, and an ITO thin film was used as the transparent electrode on the flat surface of the liquid crystal display. An alignment film for aligning the liquid crystal compound molecules contained in the liquid crystal material in a specific direction After the coating was first formed, a pair of transparent electrodes and a transparent substrate were used.

The transparent electrodes in different directions and the alignment film surface formed on the transparent substrate are contacted on the scattered fine particles, and the two transparent electrodes and the transparent substrate are overlaid together. Then, the periphery of the substrate is bonded and sealed with a sealing resin, and finally liquid crystal is injected. After sealing, a liquid crystal display device was manufactured.

In Examples 2A to 2B, the dispersed polymer particles were dispersed, and then the dispersion density was measured by a liquid crystal spacer counter device. Specifically, ten virtual horizontal lines and virtual vertical lines were set at equal intervals on the scattering surface, respectively, and the scattering densities of 100 intersection points were obtained, and the average of the calculated values was taken as the average particle scattering density. The statistical distribution of dispersion density was calculated from the average particle dispersion density calculated above.

As a result of the measurement by the above method, the average particle dispersion density was 130 pieces / mm 2, the maximum value of the dispersion density was 147 pieces / mm 2, the minimum value was 114 pieces / mm 2, and the statistical dispersion was 14%. On the other hand, a plurality of particle aggregates (adherent particles) were not observed in the plane where the dispersion density was measured.

Further, when the liquid crystal cell prepared in Examples 2A to 2B was mounted on the liquid crystal display device to drive the liquid crystal display device, no shadow of the display image was generated, and the contrast ratio during illumination was hardly reduced.

INDUSTRIAL APPLICABILITY The present invention can be used for a liquid crystal display spacer of high definition and large screen, and has excellent dispersion property and liquid crystal alignment control force, excellent hot-melt adhesion property, and a kind and content of surface functional layer introducing monomer. Therefore, the surface functional layer can be designed in various physical properties, and the encapsulated or surface functionalized monodisperse polymer fine particles produced by implementing a continuous metal / polymer layer on the surface of the polymer fine particle having a fully-interpenetrating polymer network (IPN) structure. And the invention to provide a method for producing the same.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

1 is a schematic view showing a process in which polymer fine particles having a fully interpenetrating crosslinked structure are made of encapsulated or surface functionalized monodisperse polymer fine particles.

2 is a cross-sectional view of a spacer for a liquid crystal display device fixed in a liquid crystal cell according to the present invention.

Brief description of the main symbols in the drawings

1: polymer dispersion 2: mixed and stirred dispersion

3: collected polymer dispersion 4: surface functionalized polymer dispersion

5: encapsulated or surface functionalized monodisperse polymer fine particles

5A: base resin fine particle 5B: surface functional layer adhered to liquid crystal cell

6: liquid crystal aligning film 7: transparent electrode and transparent substrate

Claims (8)

Preparing a polymer dispersion (1) by dispersing a polymer fine particle having a full-interpenetrating polymer network structure in an aqueous solution in which an oxidation-reduction initiator, an acid, and an emulsifier are dissolved together; The dispersion 2 is prepared separately by mixing and stirring an organic solvent in which a monomer, an initiator, and a crosslinking agent are dissolved, and an aqueous solution in which a dispersion stabilizer is dissolved. The mixed and stirred dispersion (2) is again mixed and stirred with the polymer dispersion (1) to prepare a polymer dispersion (3) collected by the mixed and stirred dispersion; Depositing and polymerizing the collected polymer dispersion (3) to form a deposition layer on the surface of the polymer dispersion to produce a surface functionalized polymer dispersion (4); And Removing the organic solvent on the surface functionalized polymer dispersion (4); Process for producing encapsulated or surface functionalized monodisperse polymer microparticles, characterized in that the step is prepared. The method of claim 1, wherein the redox initiator is selected from the group consisting of Cerium sulfate, Ceric ammonium sulfate, Ceric ammonium nitrate, and Ceric perchlorate, wherein the acid is sulfuric acid or nitric acid, encapsulation or surface functionalization Method of producing monodisperse polymer fine particles. According to claim 1, wherein the polymer fine particles having a fully interpenetrating crosslinked structure Long-chain crosslinking agents, monomers, oil-soluble initiators, and dispersion stabilizers are dissolved in alcohol, dispersed and polymerized, and then washed and dried to prepare cross-linked seed particles; Dispersing the crosslinked seed particles into an aqueous solution in which an emulsifier is dissolved to prepare a seed dispersion; A second crosslinking monomer in which an oil-soluble initiator is dissolved is separately emulsified in an aqueous solution in which an emulsifier is dissolved, and then added to the seed dispersion to swell to prepare a polymer dispersion; And Stabilizing the polymer dispersion using a dispersion stabilizer to polymerize, followed by washing and drying; Method for producing the encapsulated or surface functionalized monodisperse polymer microparticles, characterized in that it comprises a step. 3. The method of claim 2, wherein the emulsifier is polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyethylene glycol, polyethylene oxide, polypropylene oxide, and polyethylene oxide-pearlypropylene oxide-polyethylene having a molecular weight of 500 to 10,000 A method for producing encapsulated or surface functionalized monodisperse polymer microparticles, characterized in that at least one selected from the group consisting of a hydroxyl group comprising a copolymer of oxide and a long chain nonionic emulsifier containing a reactive vinyl group together. The method of claim 1, wherein the monomer is styrene, p- or m-methylstyrene, p- or m-ethylstyrene, p- or m-chlorostyrene, p- or m-chloromethylstyrene, styrenesulfonic acid, p- or m-t-butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl ( Meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate Polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, vinyl acetate, Vinyl propionate, vinyl butyrate, non Ethers, allyl butyl ethers, allyl glycidyl ethers, unsaturated carboxylic acids including (meth) acrylic acid or maleic acid, alkyl (meth) acrylamides, (meth) acrylonitrile and dicyclopentadiene, methylene norbornene, and A method for producing encapsulated or surface functionalized monodisperse polymer microparticles, characterized in that at least one member is selected from the group consisting of cyclic vinyl derivatives including camphor. The method of claim 1, wherein the crosslinking agent is divinylbenzene, 1,4-divinyloxybutane, divinylsulphone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, and triallyl trimellitate Allyl compound and (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, penta erythritol tetra (meth) acrylate, penta erythritol tri (meth) ) Acrylate, pentaaryl tritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, inpentaaryl tritol penta (meth) acrylic At least one selected from the group consisting of an acrylate, and an acrylic compound containing glycerol tri (meth) acrylate, wherein the method for producing encapsulated or surface functionalized monodisperse polymer fine particles method. Encapsulated or surface functionalized hard monodisperse polymer microparticles prepared by the method of any one of claims 1 to 6. A spacer for a liquid crystal display device (LCD) using the encapsulated or surface functionalized hard monodisperse polymer fine particles of claim 7.