JPH04223444A - Device for scattering fine particles - Google Patents

Abstract

PURPOSE:To uniformly monodisperse spacer fine particles on a glass substrate for a liquid crystal cell. CONSTITUTION:Fine particles which are entrained by compressed air and introduced into a dispersing room 40 from a fine particle inlet 41 collide with an impingement part 43 and fine particles which have been aggregated or combined into lumps are separated into individual particles to be in the monodisperse state. After that, the air laden with these fine particles enters a scattering room 50 from a fine particle nozzle 42 and decreases in pressure suddenly to expand and fall in laminar flow in the scattering room 50. As a result, the fine particles are scattered on the glass substrate 54 uniformly.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for dispersing fine particles using compressed gas and spraying them onto the surface of an object such as a substrate.

0002

[Prior Art] Conventionally, it has been required for liquid crystal cells to uniformly and monodisperse fine particles used as a spacer material onto a substrate, and a device for dry dispersing fine particles together with a gas has been used as a device for this purpose. It has been known. for example,
JP-A No. 64-88430 discloses a device that ejects compressed gas from a nozzle, uses the negative pressure generated at the time to suction spacer material, and sprays the spacer material onto a substrate from the ejection port. is disclosed. Further, the above publication describes a base having a through hole filled with a spacer material,
The base is vibrated, and the spacer material is removed by removing excess spacer material other than the through holes and transferring the spacer material filled in the through holes to the supply section of the spraying device. A device is disclosed that automatically performs weighing and feeding.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned dispersion device, aggregates are formed due to the van der Waals force and electrostatic force of the particles, and aggregates of the particles are formed on the substrate, and these particles There was a problem that the liquid adhered to the walls of the spraying equipment. this is,
In general, fine particles with an average particle diameter of 0.1 to 20 μm are van der
This is because aggregation occurs due to Waals force or electrostatic force, and as a result, it is extremely difficult to uniformly monodisperse fine particles on the surface of an object such as a substrate such as glass.

The present invention is intended to solve the above-mentioned problems, and its object is to provide a dispersion device that can uniformly and monodisperse fine particles onto a substrate.

[0005]

[Means for Solving the Problems] A particulate dispersion device according to the present invention is provided with a particulate inlet at one end of a particulate dispersion chamber for receiving particulates together with compressed gas from the outside, and
The other end of the dispersion chamber is provided with a particle ejection port, the ejection port is opened into the dispersion chamber, and an impactor is disposed close to the dispersion chamber at a position opposite to the particle introduction port. The problem was solved by the means established.

[0006]

[Operation] The fine particles introduced into the dispersion chamber through the fine particle inlet while being entrained by the compressed gas collide with the colliding body, and the fine particles that have been aggregated or aggregated are separated into individual particles and become monodispersed. Then, the gas entrained by the fine particles enters the dispersion chamber through the fine particle jetting port, where the pressure rapidly decreases and the gas expands. As a result, the monodispersed fine particles are further diffused, fall in a laminar flow inside the dispersion chamber, and are uniformly dispersed onto the surface of an object such as a substrate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a particulate dispersion device according to the present invention in a partially vertical side view. In the upper part of the figure, a quantitative supply device 10 for fine particles is shown.
0 consists of an inverted conical hopper 11 and a two-way cock 20 fixed to the bottom thereof, and a stirrer 12 is installed inside the hopper 11.

The two-way cock 20 is composed of a cock body 21 having a particulate passage 22 in the vertical direction, and a stopper 25 that rotates perpendicularly to the passage 22. 26 is a blocking hole formed on the outer periphery of the stopper 25 at a position facing the feed port 13 of the hopper 11, and the hole is made to an appropriate size and depth depending on the size of the feed port 13 and the amount of fine particles supplied. Set. A gas flow path 27 is formed in the stopper 25 and communicates with the blocking hole 26, and is connected to a suction line 31 and a pressurizing line 32 for working gas. In this embodiment, by switching the three-way valve 33, the suction line 31 and the pressurizing line 32 are brought into communication with the gas flow path 27. Further, a metal screen 28 is provided between the blocking hole 26 and the gas flow path 27, and the screen 28 is made of metal and has pores that are large enough to prevent fine particles from passing through.

[0009] In the present invention, it is also possible to employ a known quantitative supply device such as a rotary valve as the device for quantitatively supplying fine particles, and in that case, the fine particle passage 2
Connect the line for introducing compressed gas to the appropriate position of 2,
It is necessary to be able to pump the fine particles into a dispersion chamber 40, which will be described later. The dispersion chamber 40 has a cylindrical shape and includes a particle inlet 41 at the top and a particle jet port 42 at the bottom, and the particle inlet 41 is connected to the particle passage 22 of the two-way cock body 21.

A collision body 43 is provided in close proximity to the particle introduction port 41 in the dispersion chamber 40 .
is secured within the dispersion chamber 40 by suitable support means (not shown). In this embodiment, the collision body 43 has a spherical shape, but it may have various other shapes such as a cone or a pyramid.

Furthermore, in order to suppress agglomeration of fine particles and improve the dispersion effect, a diffuser pipe 45 for compressed air is extended from the pressurizing line 32 through a valve 44.
The distal end portion may be provided near the collision body 43 within the dispersion chamber 40. In this embodiment, four diffuser pipes 45 for compressed air are inserted, and each diffuser pipe 45 has an inclination angle of about 35 to 55 degrees with respect to the radial direction of the cylindrical dispersion chamber 40, and horizontally. It is also arranged at an inclination angle of about 35 to 55 degrees. Furthermore, in the dispersion chamber 40, a filter (
(not shown) may be installed. The material of the filter and the number of stages are appropriately selected depending on the particle size and type of the fine particles, but for example, filters made of stainless steel or resin such as nylon can be provided in about three stages above and below.

Reference numeral 47 denotes a dispersion nozzle connected to the particle jetting port 42, and the tip of the nozzle 47 is connected to the box-shaped dispersion chamber 5.
The nozzle 47 is opened at the top of the nozzle 47, and is configured such that the tip of the nozzle 47 moves circularly on a horizontal plane by a rotating means 48. The tip of the nozzle 47 is bent, and the bending angle is preferably 30 degrees or less with respect to the vertical direction. The appropriate rotational speed of the nozzle 47 during spraying is about 1 to 10 times/second. Note that if the area of the substrate 54 on which the fine particles are scattered is narrow, the tip may not be bent or the rotating means 48 may not be provided.

A grid 52 is provided at the lower part of the dispersion chamber 50, and a substrate 54 is placed on the grid 52. Further, it is preferable to apply an antistatic material to the inner surface of the dispersion chamber 50. Reference numerals 49 and 55 are earths provided in the dispersion chamber 40 and the dispersion chamber 50, respectively, and the alphabetical character D indicates a driving machine.

Next, the operation of this embodiment will be explained. First, fine particles 15 are placed in the hopper 11 in advance, and the fine particles 15 are thoroughly mixed with the stirrer 12. At this time, the closing hole 26 formed in the stopper 25 of the two-way cock 20 is directed downward. Subsequently, the stopper 25 is rotated by a half turn by the driving device D, and a portion of the fine particles 15 in the hopper 11 is filled into the blocking hole 26 by making the blocking hole 26 and the feeding port 13 of the hopper 11 face each other. Therefore, if the three-way valve 33 is switched and the gas flow path 27 is connected to the suction line, the blockage hole 2
A certain amount of fine particles are densely packed inside. There is no particular limit to the pressure reduction by suction, but for example, -50 to 500 mm.
It is preferable to maintain a constant reduced pressure within a range of about Hg.

Next, the stopper 25 is turned half a turn again to close the blocking hole 26.
is communicated with the particulate passage 22 of the two-way cock 20, and almost at the same time, the three-way valve 33 is switched to connect the gas flow passage 27 with the pressurizing line 32, so that all particulates in the blockage hole 26 are discharged through the particulate passage 22. Ru. By repeating the above operation, fine particles are continuously and quantitatively supplied. Through the particle passage 22, from the particle inlet 41 to the dispersion chamber 4.
The fine particles supplied into the colliding body 43 collide with the colliding body 43, and the fine particles that were aggregated or aggregated are separated into individual particles and become monodispersed.

Further, due to the jet force of the compressed air from the aeration pipe 45, the fine particles become dispersed as single particles, and the air entrained with the fine particles passes through the spray nozzle 47 connected to the fine particle outlet 42, and enters the scattering chamber. 50, the pressure suddenly drops and it expands. As a result, the monodisperse fine particles further diffuse and descend in the dispersion chamber 50 as a laminar flow.
It is evenly distributed onto a substrate 54 supported by a grid 52. A method of supporting the substrate 54 by laying a flat plate made of a conductive material having at least the same contact area with the substrate 54 between the substrate 54 and the grid 52 is a method of supporting the substrate 54 without being affected by the surface resistance of the substrate. This is preferable because the dispersion density becomes uniform.

The air introduced into the dispersion chamber 50 passes through the grid 52 and exits to the outside together with the fine particles that did not land on the substrate, but these fine particles can be recovered and used again. In addition, in the particle size range of about 0.1 to 20 μm, fine particles may aggregate due to electrostatic force or adhere to indoor walls, but this can be avoided to some extent by providing earths 49 and 55. be able to. Furthermore, the scattering density of fine particles onto the substrate is determined by the scattering nozzle 47.
This can be controlled by changing the distance between the substrate 54 and the substrate 54, the number of times the spraying operation is repeated, the volume of the blocking hole 26, etc.

[Example 1] Using the apparatus shown in FIG.
Silica fine particles with an average particle size of 6.3 μm were placed in a 30 cm x 30
It was dispersed onto a cm-sized glass substrate. As for the spraying conditions, the amount of silica fine particles sprayed was 0.15 g, the amount of air used was 15 liters, and the spraying time was 2 seconds. Table 1 shows the spraying results at that time.

[Example 2] Size is 50cm x 50cm
Fine particles were sprayed onto a glass substrate under the same spraying conditions as in Example 1, except that the substrate was used. Table 1 shows the spraying results at that time.

[0020]

[Table 1]

Table 1 shows that when fine particles were dispersed using the apparatus of the present invention, the fine particles were uniformly dispersed on the glass substrate, and no aggregated particles of three or more were observed.

[0022]

[Effects of the Invention] In the particle dispersion device of the present invention, the particles supplied into the dispersion chamber from the particle inlet collide with the colliding body and become monodispersed. It has the effect of being able to uniformly monodisperse. Therefore, by quantitatively supplying fine particles from the fine particle inlet, it is possible to scatter fine particles onto the substrate with less variation in scattering density, making it suitable as a device for scattering fine particles onto glass substrates used in liquid crystal cells. be.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical side view showing an embodiment of a particulate dispersion device according to the present invention.

[Explanation of symbols] 10　　　Quantitative supply device 11 Hopper 20 2-way valve 27 Gas flow path 40 Dispersion room 41 Particulate inlet 42 Particulate spout 43 Collider 45 Diffusion pipe 50 Spreading room 54 Board

Claims (1)

[Claims] Claim 1: A particulate inlet is provided at one end of the particulate dispersion chamber for receiving particulates from the outside together with compressed gas, and a particulate jetting port is provided at the other end of the dispersing chamber, and the jetting part is opened into the dispersion chamber. and a particle dispersion device further comprising: an impactor disposed close to the dispersion chamber at a position facing the particle introduction port.