KR20060132173A - Method for preparing of monodisperse high bridged polymer plastic bead - Google Patents

Abstract

Provided are a method for preparing a polymer plastic bead to allow the particle size and compressive modulus of a polymer plastic bead, a polymer plastic bead prepared by the method, a conductive particle containing the plastic bead, and an LCD device containing the plastic bead. The method comprises the steps of mixing an acrylic monomer, an initiator and a solvent and polymerizing the mixture by using a stirrer or an ultrasonic wave device to prepare a monodisperse bead; and filtering and drying the obtained monodisperse bead. Preferably the polymerization is carried out at 50-90 deg.C for 20-30 hours. Preferably the acrylic monomer is at least one selected from methyl (meth)acrylate, ethyl (meth)acrylate, trimethylomethane tetraacrylate, trimethylomethane triacrylate, trimethylobutane triacrylate, glycidyl (meth)acrylate, and ethylene glycol diglycidyl (meth)acrylate.

Description

Manufacturing method of monodisperse high crosslinked polymer plastic beads {METHOD FOR PREPARING OF MONODISPERSE HIGH BRIDGED POLYMER PLASTIC BEAD}

1 is a cross-sectional view showing a general liquid crystal display device.

2 is a photograph showing a plastic bead prepared according to an embodiment of the present invention.

Figure 3 is a photograph showing the particles formed by forming a metal coating layer on the plastic beads prepared according to an embodiment of the present invention.

The present invention relates to a method for producing monodisperse high-crosslinked polymeric plastic beads, and more specifically, to synthesize beads with high efficiency through a single process of monodisperse beads, freely adjusting the particle size, compression modulus and recovery rate Not only can be prepared, but the prepared polymer plastic beads relates to a method for producing polymer plastic beads which are particularly suitable for the production of conductive particles for anisotropic conductive connection and application to a liquid crystal display device.

Anisotropic conductive connection is often used to connect the connection terminal of a semiconductor element with the connection terminal of the mounting board. This anisotropic conductive connection is a method in which fine conductive particles are adhered by sandwiching a film or a space-shaped anisotropic conductive connection material dispersed in an insulating adhesive to be heated and pressurized.

In recent years, the use of liquid crystal displays has been rapidly increasing as display devices. In general, liquid crystal display devices used in liquid crystal displays include spacers as shown in FIG.

The liquid crystal display device includes a pair of substrates 37 and 39, a spacer 38 provided between the pair of substrates 37 and 39, and a nematic liquid crystal 41 so as to maintain a constant cell gap therebetween. ), The sealing material 30 filled around the cell gap between the substrates 37 and 39 and the polarizing sheets 42 and 43 coated on the surfaces of the substrates 37 and 39. have.

In the case of the conductive particles used for the anisotropic conductive connection material, it is composed of a spherical organic bead-conductive metal coating layer (metal layer) from the inside, and is formed by further coating an insulating coating layer on the surface of the metal layer, if necessary. However, as the pattern of the connection terminal that is the target of the anisotropic conductive connection is gradually miniaturized, there is a concern that short circuit occurs during the conductive connection. Accordingly, an attempt to increase contact reliability by using conductive particles of uniform size is progressing. In addition, a technique for efficiently producing spherical organic beads having a uniform particle size has been steadily required.

In addition, the organic bead may be directly applied to the spacer of the liquid crystal display, or may be applied by coating a metallic material on the surface of the organic bead to enhance physical properties.

Therefore, in the case of the ceramic particles and the spacer, a plastic bead having a uniform particle size and a uniform particle size is required, but the conventional method for producing the spherical plastic beads is classified after emulsion polymerization or suspension polymerization of monomers and stabilizers, etc. Although manufactured through, there is a problem that the efficiency after the classification is very low efficiency less than 3%.

In order to solve the problems of the prior art as described above, the present invention synthesizes the beads with high efficiency through a single process of the monodisperse beads, the production of polymer plastic beads that can be produced by controlling the compressive modulus and recovery rate freely It is an object to provide a process and polymeric plastic beads made therefrom.

Another object of the present invention is applied to the conductive particles and the liquid crystal display device for anisotropic conductive connection, the alignment characteristics of the liquid crystal due to excellent contact reliability and damage to the alignment control film does not change or the quality of the image deterioration, causing irregularity in the cell gap The present invention provides a polymer plastic bead, a polymer plastic bead prepared therefrom, and conductive particles for anisotropic conductive connection to which the polymer plastic bead is applied, and a liquid crystal display device.

In order to achieve the above object, the present invention is a method for producing a polymer plastic beads,

a) i) an acrylic monomer, ii) an initiator, and iii) a solvent, followed by polymerization using a device or ultrasonic apparatus capable of stirring up and down or left and right to synthesize monodisperse beads; And

b) filtering and drying the monodisperse beads synthesized in step a)

It provides a method for producing a polymer plastic bead comprising a.

The present invention also provides a polymer plastic bead prepared by the above method.

In another aspect, the present invention provides conductive particles for anisotropic conductive connection comprising the polymer plastic beads.

In another aspect, the present invention provides a liquid crystal display device comprising the polymer plastic beads.

Hereinafter, the present invention will be described in detail.

The polymer plastic beads of the present invention are a) i) an acrylic monomer, ii) an initiator, and iii) a solvent to polymerize using a device or an ultrasonic device capable of stirring up and down or left and right to synthesize monodisperse beads; And b) filtering and drying the monodisperse beads synthesized in step a).

Referring to the manufacturing method of the polymer plastic beads of the present invention in detail.

a) bead synthesis

This step is a step of synthesizing monodisperse beads by iii) mixing acrylic monomers, ii) initiators, and iii) solvents, followed by polymerization using a device or ultrasonic apparatus capable of stirring up or down, left and right.

Compressive modulus and recovery rate of the finally produced polymer plastic beads can be controlled according to the type of the iii) acrylic monomer used in this step or when mixing two or more kinds.

The acrylic monomer may be methyl (meth) acrylate, ethyl (meth) acrylate, trimethylmethane tetraacrylate, trimethylmethane triacrylate, trimethylbutane triacrylate, glycidyl (meth) acrylate, or ethylene Glycol diglycidyl methacrylate etc. can be used individually or in mixture of 2 or more types.

In addition, the acrylic monomer may be used in further mixing with styrene or divinylbenzene, the styrene or divinylbenzene reacts with the acrylic monomer to form the final polymer plastic beads.

The acrylic monomer and styrene or divinylbenzene are preferably mixed in a weight ratio of 10 to 90:90 to 10, and more preferably in a weight ratio of 30 to 70:70 to 30. When the mixing ratio is within the above range, the refractive index, strength, and physical properties of the final polymer plastic beads to be produced are better.

The initiator of ii) used in this step serves to control the particle size and particle distribution of the monodisperse beads formed.

The initiators are 2,2-azobisisobutyronitrile, 2,2-azobis (2-methylbutannitrile), 3,3-azobis (4) -cyanopenta which can be initiated by pyrolysis in the non-aqueous phase. Azo initiators such as no acid, 2,2-azobis (2-methylbutyronitrile), or 2,2-azobis (2,4-dimethylvalenonitrile); Or a peroxide-based time-sensitive agent such as benzoyl peroxide, lauryl peroxide, octanoyl peroxide, or 3,3,5-trimethyl hexanoyl peroxide.

The initiator is preferably included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the mixed amount of the acrylic monomer and the styrene monomer. If the content is too small, the polymerization is not made, if too much, there is a problem that can not form polymer plastic beads of monodisperse particles.

As the solvent of i) used in this step, it is preferable to use a solvent in which the monomers and the initiator can be completely mixed.

The solvent is acetonitrile; Alcohols such as methanol, ethanol, butyl alcohol, amyl alcohol, octyl alcohol, or benzyl alcohol; Or polyhydric alcohols such as ethylene glycol, propylene glycol, or glycerin. In consideration of the monomer solubility value of the polymerization solvent, such a solvent may be used by mixing one or two or more of the solvents having similar solubility values with the monomers, stabilizers, and the like.

The solvent is preferably included so that the solid content of the acrylic monomer, such as 0.1 to 5% by weight.

The acrylic monomer, the initiator, and the solvent as described above are uniformly mixed, and then polymerized by using a device or an ultrasonic device capable of stirring up and down, left and right, to form monodisperse beads. At this time, the present invention has the advantage that it is possible to form monodisperse beads without performing the classification performed after the polymerization by polymerizing by using a device or ultrasonic apparatus capable of stirring up and down or left and right as described above.

In a preferred embodiment, the mixture of the acrylic monomer, the initiator, and the solvent is put in a glass bottle capable of nitrogen purge, purged with nitrogen for 2 to 3 minutes, and then 60 to 80 in an apparatus (water bath, etc.) capable of stirring up and down or left and right. The polymerization is carried out by stirring at rpm or by stirring using an ultrasonic device. At this time, the polymerization is preferably carried out for 20 to 30 hours at a temperature of 50 to 90 ℃.

b) filtration and drying

This step is a step of filtering and drying the monodisperse beads synthesized in the above step.

The monodisperse beads, which have been polymerized in the above step, are present in a precipitated state under a glass bottle. The precipitated monodisperse beads are recovered by centrifugation or filtering through a filter paper, and then recovered in a vacuum oven at 70 to 80 ° C. Drying for 30 to 30 hours may give a final polymer plastic beads.

The polymer plastic beads of the present invention prepared as described above preferably have an average particle diameter of 1 to 10 µm, a compressive modulus of 100 to 700 kgf / mm 2, and a recovery rate of 10 to 60%.

When the compressive elastic modulus is less than 100 kgf / mm 2, cell gap control is difficult when used in a liquid crystal display device spacer. When the compressive elastic modulus is used in a liquid crystal display device spacer when it exceeds 700 kgf / mm 2, the liquid crystal during the manufacturing process of the liquid crystal display device. The surface of the alignment control film is easily damaged, and the spacer of the liquid crystal display device manufactured as described above has a problem in that bubbles are generated due to reduced pressure in the liquid crystal cell because the change in compression is difficult due to the liquid crystal shrinkage at a lowered temperature. . In addition, when the recovery rate is less than 10%, an excessively pressurized portion does not return to a desired cell gap. When the recovery rate is higher than 60%, the pressure press during the manufacturing process of the liquid crystal cell when used in the liquid crystal display device spacer. By adjusting the gap between the substrates and then reducing the pressure, the spacer deformed by compression tends to be returned to its original shape by elasticity, resulting in an unsuitable cell gap of the obtained liquid crystal cell.

According to the manufacturing method of the polymer plastic beads of the present invention as described above, it is possible to synthesize monodisperse beads with high efficiency without performing classification after polymerization without using a stabilizer, and to control extrusion modulus and recovery rate. have. Figure 2 shows the polymer plastic beads prepared according to one embodiment of the present invention shows that the polymer plastic beads of the present invention are polymer plastic beads of uniform size in spherical shape.

In another aspect, the present invention provides a conductive particle for anisotropic conductive connection comprising the polymer plastic bead, preferably the conductive particle is a coating layer (metal layer) of the polymer plastic bead-conductive metal, more preferably the polymer plastic bead -Conductive metal film layer (metal layer)-Insulation coating layer is preferred. The coating layer (metal layer) and the insulating coating layer can be applied to the coating layer and the insulating coating layer is usually applied to the conductive particles for conductive connection, as a specific example, the coating layer may be Ni / Au of 0.1 to 1.0 thickness. . Figure 3 shows the conductive particles formed with a metal coating layer on the polymer plastic beads of the present invention can be seen that the particles of a uniform size. By using the electroconductive particle for anisotropic conductive connection by this invention, the contact reliability of the conductive connection of the semiconductor element refine | miniaturized at the time of a conductive connection can be improved significantly.

In addition, the present invention provides a liquid crystal display device comprising the polymer plastic beads, the liquid crystal display device can be manufactured through a conventional method for manufacturing a liquid crystal display device using the polymer plastic beads as a spacer, of course, The liquid crystal display device according to the present invention does not change the alignment characteristics of the liquid crystal due to damage of the alignment control film or deteriorate the image quality, and does not cause irregularity in the cell gap due to monodispersion.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

20 parts by weight of methyl (meth) acrylate and 80 parts by weight of trimethylmethane triacrylate were added 1% by weight of the mixed monomer and 2,2-azobis (2-methylbutanenitrile) to 0.05% by weight of the remaining acetonitrile. It was. Then, the mixed solution was placed in a glass bottle capable of nitrogen purge and purged with nitrogen for 2 to 3 minutes, and then polymerized at 70 ° C. for 24 hours while stirring at a speed of 70 rpm in a water bath capable of left and right stirring.

After completion of the polymerization, the reactant precipitated in the glass bottle was filtered through centrifugation, washed with water, and dried in a vacuum oven at a temperature of 70 to 80 ° C. for 24 hours to obtain a compressive modulus of 580 kgf / mm 2 and a recovery rate of 54. A monodisperse 4 μm beads of% were prepared. The efficiency was 95%.

Example 2

Except for using the ultrasonic equipment in place of the water bath capable of stirring left and right in Example 1 was carried out in the same manner as in Example 1, the compressive modulus of 580 kgf / ㎜, recovery rate of 54% monodisperse 3.5 ㎛ Beads were prepared. At this time, the ultrasonic equipment was a product of Eltech Co., Ltd., was applied during the polymerization of 20 to 30 hz. The efficiency was 96%.

Example 3

Except for using a monomer mixture of 10 parts by weight of methyl (meth) acrylate and 90 parts by weight of divinylbenzene in the monomer mixture in Example 1 was carried out in the same manner as in Example 1, the compression modulus of 380 kgf / Beads of monodisperse 4 μm having a mm 2 and recovery of 38% were prepared. The efficiency was 94%.

Example 4

Compression was carried out in the same manner as in Example 1, except that 2,2-azobisisobutyronitrile was used in place of 2,2-azobis (2-methylbutanenitrile) as an initiator in Example 1. Beads of monodisperse 4.5 μm having an elastic modulus of 580 kgf / mm 2 and a recovery of 54% were prepared. The efficiency was 94%.

Example 5

Except for using acetonitrile as a solvent in Example 1 in the same manner as in Example 1 was carried out in the same manner as in Example 1, the compressive modulus of 580 kgf / ㎜, recovery of 54% monodisperse 3.2 ㎛ beads Prepared. The efficiency was 96%.

Comparative Example 1

Beads were prepared by classification after suspension polymerization, which is a conventional method for preparing plastic beads, using the same components as in Example 1, wherein a single dispersion of 4 μm having a compressive modulus of 438 kgf / mm 2 and a recovery rate of 48% Was prepared. This method has two stages of polymerization and classification in the process, and the efficiency after the classification is very low.

Polymeric plastic beads according to the present invention synthesize the beads with high efficiency through a single process of the monodisperse beads, can be prepared by controlling the compressive modulus and recovery rate freely, as well as conductive particles and liquid crystal for anisotropic conductive connection Applied to the display device, it has excellent contact reliability, and does not change the alignment characteristic of the liquid crystal due to damage of the alignment control film or deteriorate the image quality, and does not cause irregularity in the cell gap.

Claims (11)

In the manufacturing method of polymer plastic beads, a) i) an acrylic monomer, ii) an initiator, and iii) a solvent, followed by polymerization using a device or ultrasonic apparatus capable of stirring up and down or left and right to synthesize monodisperse beads; And b) filtering and drying the monodisperse beads synthesized in step a) Method for producing a polymeric plastic bead comprising a. The method of claim 1, The acryl-based monomer of a) iii) is methyl (meth) acrylate, ethyl (meth) acrylate, trimethylmethane tetraacrylate, trimethylmethane triacrylate, trimethylrobutane triacrylate, glycidyl (meth). At least one selected from the group consisting of acrylate and ethylene glycol diglycidyl methacrylate. The method of claim 1, The acrylic monomer of a) i) is mixed with styrene or divinylbenzene in the weight ratio of 10-90: 90-10, The manufacturing method of the polymeric plastic bead characterized by the above-mentioned. The method of claim 1, The method of claim 1, wherein the initiator of a) ii) is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the mixed amount of the acrylic monomer and the styrene monomer. The method of claim 1, Method for producing a polymeric plastic bead comprising the solvent of a) i) so that the solid content is 0.1 to 5% by weight. The method of claim 1, Polymerization of the polymer plastic beads, characterized in that the polymerization of step a) is carried out for 20 to 30 hours at a temperature of 50 to 90 ℃. The method of claim 1, The drying of step b) is a method for producing polymer plastic beads, characterized in that carried out for 20 to 30 hours at a temperature of 70 to 80 ℃. A polymer plastic bead produced by the method of claim 1. The method of claim 8, The polymeric plastic beads having an average particle diameter of 1 to 10 µm, a compressive modulus of 100 to 700 kgf / mm 2, and a recovery rate of 10 to 60%. The conductive particle for anisotropic conductive connection containing the polymeric plastic bead of Claim 11. A liquid crystal display device comprising the polymer plastic beads of claim 11.

Images