JP2004348160A - Slit plate and optical microscope equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which a very small quantity of coarse particles contained in a minute particle group having an average grain size within a range of 0.5 to 10 μm is detected and judged and its content is quantified. <P>SOLUTION: A slit plate which is mounted on an optical irradiation device of an optical microscope and is used for irradiation with reverse slit light is constituted of an outer peripheral section having an opened central part and a light shielding section which is fixed to or is suspended from the outer peripheral section through a center or a vicinity of an opened part located inside the outer peripheral section. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a slit plate to be mounted on a light irradiation device of an optical microscope for use, and to an optical microscope having the same.

  2. Description of the Related Art In recent years, fine particles (nano-sized or micron-sized particles) such as conductive particles, insulating particles, and semiconductor particles have been used for electronic device materials, photocatalytic materials, and the like. Use forms include those that are evenly scattered on a substrate, those that form a dense single-layer film, those that further laminate this single-layer film to form a multilayer film, and thin films in which fine particles are dispersed in a matrix. And the like.

  More specifically, in a liquid crystal display device, a spacer is interposed between a pair of electrodes provided in a liquid crystal cell for a liquid crystal display device to maintain a gap between the electrodes, and a liquid crystal substance is sealed. Thus, a liquid crystal layer is formed. However, if the thickness of the liquid crystal layer is not uniform, the image displayed on the liquid crystal cell may cause color unevenness or decrease in contrast at the time of lighting. In particular, even when switching a display image at a high speed or displaying an image having a wide viewing angle, it is required to make the thickness of the liquid crystal layer inside the liquid crystal cell uniform.

  Further, at present, a large screen liquid crystal display device of the STN mode is used, and in order to display a large screen without color unevenness on such a large screen, the liquid crystal layer inside the liquid crystal cell is further increased. A uniform thickness is required.

  Conventionally, in order to make the thickness of the liquid crystal layer inside the liquid crystal cell uniform, spherical particles having a uniform particle diameter are interposed between the electrodes of the liquid crystal cell (in-plane spacer) or contained in a seal portion around the electrode. In such a case, the gap between the electrodes is maintained uniformly by using a spacer (spacer for a seal portion). Further, as such particles, organic compound fine particles such as polystyrene and inorganic compound fine particles such as silica are used.

  On the other hand, in recent years, a cell gap (or a distance between electrodes) has been narrowed in order to increase the response speed of liquid crystal of a liquid crystal display device, and a wiring width has been narrowed in order to improve display performance. . For example, in a small display device such as a personal digital assistant (PDA) and a mobile phone, the cell gap is set to about 5 μm or less, and the wiring width is reduced to about 1 to 3 μm.

  For this reason, spacers having a particle diameter of about 5 μm or less have been used, and spacers having a uniform particle diameter and an extremely small particle diameter variation coefficient (CV value) have been required. I have.

  However, despite the spacer having a small coefficient of variation in particle diameter, the trace amount of coarse particles causes an increase in wiring resistance due to damage to the electrodes, disconnection of wiring, or display unevenness. was there.

  Also, when conductive fine particles or anisotropic conductive particles are used not only for the spacer but also for the connection part of the electrode, etc., the electrode may be damaged by a minute amount of coarse particles, or poor conduction or short-circuit (referred to as lateral conduction). May occur).

Thus, the present inventors have conducted intensive studies in order to investigate such a cause, and as a result, the spacer particles have a very small amount (trace amount) of coarse particles, particularly a particle diameter of 1.2 times or more the average particle diameter. It was found that coarse particles were the cause.

  However, since such coarse particles are too small in quantity, they are not reflected in the average particle diameter or CV value, and it is difficult to detect them by one electron microscopic photograph observation, and the detection results are reliable. In order to detect this with high accuracy, it is necessary to take and photograph a large number of photographs, and it has been known that such observation requires time and effort and is expensive. On the other hand, there is no efficient method for detecting and quantifying minute coarse particles that can be used commercially. For this reason, there has been no method of detecting coarse particles other than removing defective or defective products by operating after assembling a product such as a liquid crystal display cell without actually detecting coarse particles.

  The reasons why such coarse particles are included in the group of fine particles such as spacer particles are as follows: (1) At the time of manufacturing fine particles, depending on the manufacturing method, aggregates of fine particles may be generated, or some particles may be generated. May remain in the apparatus, causing repeated particle growth, (2) insufficient removal of coarse particles by a classification operation or the like, (3) minute particles of another type having a large average particle diameter may be mixed, Alternatively, it is known that (4) other foreign substances are mixed in, and it is also said that it is difficult to completely solve these problems.

  Therefore, in the inventions of Patent Document 1 and Patent Document 2, a method of dispersing a group of fine particles including such coarse particles in an air stream and passing the fine particles through a sieve having a certain opening is used to separate the coarse particles. Etc. have been proposed.

However, in these patent documents, regarding the measurement of the coarse particles, there is a method of simply visually or photographic analysis using a scanning electron microscope (SEM) or the like, or a method of measuring using a Coulter counter method. It is merely disclosed.
JP-A-9-318951 JP 2002-166228 A

Heretofore, there has been no method for efficiently detecting and determining a small amount of coarse particles contained in a group of fine particles having an average particle diameter in the range of 0.5 to 10 μm, and quantifying the content.
Therefore, the present inventors have repeatedly conducted intensive studies on a method of detecting, determining and quantifying coarse particles contained in a minute amount in such a fine particle group, that is, a method of quantitatively grasping, and found that the fine particles were regularly regulated. Coarse particles having a large particle diameter are very conspicuous as compared with other fine particles when they are arranged regularly, and it has been found that they can be easily detected and determined by scanning observation with an optical microscope. Then, by scanning the visual field of the microscope in a certain direction using an optical microscope equipped with a light irradiation device having a specially designed slit plate, it is possible to observe tens of millions to hundreds of millions of microparticle groups. Can be carried out in a short period of time, and the coarse particles can be easily detected and quantitatively grasped, and the present invention has been completed.

The first slit plate according to the present invention,
A slit plate mounted on a light irradiation device of an optical microscope to irradiate reverse slit light, an outer peripheral portion having a central portion opened, and a center or an opening portion inside the outer peripheral portion. And a light-shielding portion fixed or suspended to the outer peripheral edge portion through the vicinity thereof.

The opening of the outer peripheral edge portion is circular, and its diameter is desirably in the range of 10 to 100 mm.
Preferably, the width of the light-shielding portion is in the range of 1 to 30 mm.

It is desirable that the slit plate has a structure in which the width of the light shielding portion can be adjusted.
The slit plate is a slit plate mounted on a light irradiation device of an optical microscope used for a method for quantifying coarse particles contained in a group of microparticles having an average particle size in a range of 0.5 to 10 μm. Is desirable.

The second slit plate according to the present invention,
A slit plate for irradiating slit light by mounting on a light irradiation device of an optical microscope used for a method for quantifying coarse particles contained in a group of fine particles having an average particle diameter in a range of 0.5 to 10 μm. So,
A rectangular slit having a width (short side) of 0.5 to 10 mm and a length (long side) of 5 to 50 mm is formed in the center.

It is desirable that the slit plate has a structure in which the width of the slit can be adjusted.
An optical microscope according to the present invention is characterized in that the above-mentioned slit plate is provided as a component thereof.

  When the slit according to the present invention is used, the average particle diameter is in the range of 0.5 to 10 μm and the particle diameter variation coefficient (CV value) is 10% or less. (Particles having a particle diameter of 1.2 times or more the particle diameter) can be efficiently detected and determined, and the content quantity thereof can be quantified. In particular, if an optical microscope equipped with a reverse slit light irradiation device is used, the coarse particles contained in the fine particle group can be detected and determined accurately and easily.

  For this reason, since the content number of the coarse particles contained in a minute amount in the fine particle group can be controlled and managed, it is possible to provide a microparticle product in which the content number of the coarse particles is equal to or less than a desired value.

  Further, in the electrical equipment and the like manufactured using the fine particle products whose quality is controlled in this way, defective products and defective products are extremely reduced, and the reliability is improved. In particular, when the microparticle product is used as a spacer particle for a liquid crystal display cell, the electrode is not damaged and the wiring is not broken, so that a problem in manufacturing the liquid crystal display cell is avoided. Can provide a high-performance liquid crystal display device having not only display unevenness but also high-density and high-definition display and excellent in high-speed response.

Hereinafter, preferred embodiments of the present invention will be described in detail.
It is desired that the fine particles used in the present invention have an average particle diameter (Dm) of 0.5 to 10 μm, preferably 1.5 to 5 μm. Here, when the average particle diameter (Dm) of the fine particles is less than 0.5 μm, the particles aggregate when forming a particle monolayer described later, and it becomes difficult to form a dense particle monolayer. In some cases, it may be difficult to discriminate the particles from coarse particles due to approaching the resolution limit of the optical microscope, so that the quantification accuracy of the coarse particles may decrease. When the average particle diameter (Dm) of the fine particles exceeds 10 μm, the light transmittance of the fine particles is greatly reduced, and the particles easily settle in the dispersion, and the uniform particles are formed on the transparent substrate. Since it is difficult to form a single layer, it is difficult to discriminate between the fine particles and a minute amount of coarse particles contained in the fine particle group during microscopic observation.

  It is desired that the fine particles have a particle diameter variation coefficient (CV value) of 10% or less, preferably 5% or less. Here, if the CV value of the fine particles exceeds 10%, the difference in light transmittance between the relatively large particles and the coarse particles among the fine particles becomes small, so that it becomes difficult to distinguish the coarse particles. In some cases, sufficient quantitative accuracy cannot be obtained.

  In particular, when the fine particles are used as spacer particles for a liquid crystal display cell, the CV value is desirably in the range of 0.5 to 5%, preferably 1 to 3%. Here, if the CV value is less than 0.5%, it is difficult to obtain a stable one, and furthermore, high-temperature color unevenness may occur on the display screen. Further, when the CV value is higher than 5%, it is difficult to keep the thickness of the liquid crystal layer uniform, which may cause image unevenness and the like.

Therefore, it is desirable that the fine particles used in the present invention be measured in advance to determine whether the average particle size and the CV value of the fine particles are in the above ranges.
The average particle diameter and the CV value in the present invention were determined using a scanning electron micrograph (SEM) of 250 particle samples contained in the fine particle group (excluding the case where the coarse particles were contained). Is calculated by measuring the particle size. That is, the average particle size is determined from the average value, and the particle size variation coefficient (CV value) is calculated by the following equation.

The microparticles used in the present invention are not particularly limited in their composition and physical properties, and in addition to spacer particles, include particles used as conductive particles, insulating particles, semiconductor particles, and the like. . Specifically, metal fine particles such as Au, Ag, Cu, Pt, Pd, Co, and Ni used as a catalyst or conductive particles, and composite metal particles (alloy fine particles) composed of two or more of these metals or other metal components ), SiO ₂ , Al ₂ O ₃ , Z
Examples include inorganic oxide particles such as rO ₂ , SiO ₂ —Al ₂ O ₃ , TiO ₂ , ZnO, SnO ₂ , La ₂ O ₃ , and In ₂ O ₃ , organic resin particles, and organic / inorganic composite particles. In addition, the present invention is also applicable to conductive particles in which the surface of insulating particles is coated with a conductive component, insulating particles in which the surface of conductive particles is coated with an insulating component, and inorganic oxide particles containing a doping material. Can be.

The shape of the fine particles is not particularly limited, but a spherical shape or a spherical shape is preferably used.
The quantification method according to the present invention is applied to those in which the number of coarse particles contained in the fine particle group is 3000 ppb or less. This is because, when the content exceeds 3000 ppb, not only does it take much time for detection and determination, but also there is no point in practically performing the quantification method according to the present invention. Therefore, in the present invention, it is more preferable to apply the present invention to those in which the content number of the coarse particles is 1000 ppb or less, more preferably 500 ppb or less. In addition, as for those having a large content of the coarse particles exceeding 3000 ppb, a small number of scanning electron micrographs (SEM), a laser scattering light method, a Coulter counter method, etc. may be used without using the method of the present invention. Using a measuring method, the content can be roughly estimated.

The coarse particles referred to in the present invention means that the particle size of the coarse particles is the average particle size (Dm) of the fine particles
It is at least 1.2 times as large as the above, and may contain spherical particle aggregates, irregularly shaped particles and the like in addition to the spherical particles. This is because the coarse particles whose particle diameter is less than 1.2 times the average particle diameter are difficult to detect and determine even by the method of the present invention, and are particularly large even when they are used for electronic devices and the like. It does not cause any problems.

  In addition, the number (N) of the fine particles inspected in the present invention is obtained by measuring the weight (W) of the particle monolayer of the fine particles arranged on the transparent substrate and the density (ρ) of the fine particles. Is calculated from the following equation.

  Further, the content number (ppb) of the coarse particles in the present invention is obtained by dividing the number (M) of the coarse particles detected by performing the quantification method according to the present invention by the number (N) of the fine particles. , And their values are converted to ppb units.

Next, the method for quantifying trace coarse particles according to the present invention will be described more specifically.
Quantitative method of trace coarse particles (1)
The first method for quantifying microscopic coarse particles according to the present invention,
Included in the group of microparticles having an average particle diameter in the range of 0.5 to 10 μm and a particle diameter variation coefficient (CV value) of 10% or less, the particle diameter of which is 1.2 times or more the average particle diameter. And a method for quantifying coarse particles having a content of 3000 ppb or less,
(A) a step of preparing a fine particle dispersion so that the particle concentration becomes 0.001 to 10% by weight; (b) applying, spraying or dropping the fine particle dispersion on the transparent substrate 1 to obtain the transparent Forming a particle monolayer 2 in which fine particles are arranged on a substrate 1;
(C) The transparent substrate 1 is placed on an optical microscope 4 equipped with a slit light irradiating device 3 and a slit plate 5 as shown in FIG. (Not shown), and (d) observing the particle monolayer 2 irradiated with the slit light while scanning the field of view in the optical microscope 4, A fine particle group of 10 to 200 million particles is closely examined, and the size is determined by visually observing the bright part 15 of the slit light appearing as an image on the inner surface of the fine particle to determine the coarseness in the single particle layer 2. The present invention relates to a method for quantifying the coarse particles contained in a minute amount in the fine particle group by detecting particles and subjecting the particles to a step of counting the number of the particles.

Each of the above steps is performed in the following manner.
Step (a)
In this step (a), an aqueous dispersion in which the fine particles are dispersed in water is prepared.

The concentration (solid content concentration) of the fine particles contained in the dispersion varies depending on the method of forming the single particle layer 2, but is 0.001 to 10% by weight, preferably 0.01 to 5% by weight, and furthermore Preferably, it is in the range of 0.04 to 4% by weight. Here, the particle concentration is 0
. When the content is less than 001% by weight, the particle monolayer 2 formed on the transparent substrate 1 is not dense, which causes a problem in quantitativeness of the coarse particles. On the other hand, if the particle concentration exceeds 10% by weight, the concentration is too high to form the particle monolayer 2 and at least a partly laminated particle film is formed to lower the light transmittance at the laminated portion. It becomes difficult to detect and determine the coarse particles present at this location.

  It is desirable that the fine particle dispersion liquid contains a surfactant as necessary. The concentration of the surfactant at this time varies depending on the concentration of the fine particles, but is desirably in the range of 0.01 to 5% by weight, preferably 0.1 to 3% by weight. Here, when the concentration of the surfactant is less than 0.01% by weight, it is difficult to stably disperse the fine particles in a monodisperse manner, and thus a particle monolayer in which the fine particles are uniformly and regularly arranged is obtained. There may not be. Further, even if the concentration of the surfactant exceeds 5% by weight, the effect of monodispersing the particles is not further improved, and in some cases, the regularity of the fine particle arrangement of the particle monolayer 2 is reduced. In some cases, a problem arises in the quantitativeness of the coarse particles.

  As such a surfactant, although it varies depending on the type of the fine particles, a conventionally known cationic surfactant, anionic surfactant, nonionic surfactant, and amphoteric surfactant are appropriately selected and used. be able to.

Further, in order to improve the dispersibility of the particles, it is desirable that the microparticle dispersion liquid be subjected to ultrasonic treatment in an ultrasonic bath for about 5 minutes before use.
Further, an evaporation rate of the dispersion medium may be adjusted by adding an organic solvent such as alcohol to water as needed. By doing so, the regularity and denseness of the obtained single particle layer 2 can be improved.

Step (b)
In this step (b), a particle monolayer 2 in which fine particles are densely arranged is formed on the surface of the transparent substrate 1 from the fine particle dispersion liquid prepared in the step (a).

  The method is not particularly limited as long as the dense particle monolayer 2 can be formed. For example, the transparent substrate 1 may be formed by a dropping method (casting method), a dipping method, a spinner method, a roll coater method, a printing method, or the like. A method of applying the composition to the surface and then drying the composition may be used. When carrying out this method, the transparent substrate 1 can be heated, cooled, or further dried under reduced pressure in order to adjust the evaporation rate of water or the dispersion medium. . At this time, if necessary, a flat plate may be pressed from above before or after the drying treatment to level the formed laminated particles to form single-layer particles (particle monolayer). Alternatively, a particle layer may be formed in advance on a sheet having excellent releasability by using the fine particle dispersion liquid and transferred to the surface of the transparent substrate.

However, it is not always easy to form the dense particle monolayer 2 on the transparent substrate 1.
Therefore, in the present invention, as shown in FIGS. 9 and 10, a metal mask 8 having an opening 9 of a desired size is mounted on the surface of the transparent substrate 1, and the transparent substrate 1 is attached as shown in FIG. Is placed at an angle of 3 to 7 °, preferably about 5 ° with respect to a horizontal plane, in a container 10 having a drain port 11 at the lower part thereof, and then the container 10 is filled with water to reach the surface of the transparent substrate 1 with water. And the microparticle dispersion liquid is dropped on the water surface using a micro-ringing syringe, a dropper or a dispenser (these are not shown). Then, when the water surface on which the microparticles float is stopped, the water is discharged from the drain port 11. It is desirable to form a particle monolayer 2 (including 0.3 to 100 million fine particles) in which fine particles are regularly arranged on the transparent substrate 1 by draining water. Here, it is desirable that the dropping of the fine particle dispersion liquid is gently performed from a place near the water surface on the transparent substrate 1.

  It is preferable that the transparent substrate 1 on which the particle monolayer 2 thus obtained is arranged on the upper surface is naturally dried in a clean booth, but the hot substrate is kept at a temperature of 100 ° C. or lower. It may be dried on a plate. In this case, if the temperature of the hot plate is too high, the particle monolayer 2 formed on the transparent substrate 1 may become sparse, and the temperature must be appropriately selected.

  The metal mask 8 is removed from the transparent substrate 1 before or after the drying process, so as not to affect the arrangement of the particle monolayer 2. Thereby, the particle monolayer 2 in which the fine particles are uniformly and regularly arranged can be formed on the transparent substrate 1. Here, the opening 9 of the metal mask 8 has a height of 2 to 10 cm and a width of 3 to 10 cm depending on the average particle diameter of the fine particles, the number of fine particles measured at a time, and the visual field of an optical microscope. Preferably, there is.

  If the single particle layer 2 is formed on the transparent substrate 1 without mounting the metal mask 8, a particle layer will be formed on the entire substrate. It is necessary to remove the portion corresponding to the mask in advance.

  As the transparent substrate 1, a transparent substrate such as a glass plate or a plastic plate is used. The transparent substrate 1 preferably has a clean substrate surface, and can be used by washing the surface with a conventionally known method, for example, using an organic solvent, pure water, steam, or the like, and then drying. Further, the surface of the transparent substrate 1 may be subjected to a hydrophilic treatment or a hydrophobic treatment. For example, when the microparticles are hydrophilic, a hydrophilized substrate is preferable, and when the microparticles are hydrophobic, a hydrophobized substrate is preferable. The use of the surface-treated transparent substrate improves the adhesion between the fine particles and the adhesion between the substrate and the fine particles, so that a regular and dense particle single layer 2 is formed on the surface thereof. As a result, the accuracy of quantifying coarse particles is improved.

  The size of the transparent substrate 1 varies depending on the average particle size of the fine particles, the number of fine particles measured at one time, the visual field of an optical microscope, the size of the opening 9 of the metal mask 8, and the like. It is preferable that the height is 5 to 15 cm and the width is 5 to 15 cm. It is desirable that the metal mask 8 can be mounted on the transparent substrate 1. However, the four corners may be fixed with clips or the like.

  Further, a jig 12 for mounting the transparent substrate 1 on which the metal mask 8 is mounted is installed in the container 10, and the transparent substrate 1 mounted on the jig 12 is inclined. It is preferable that the angle be adjusted to the above range.

Step (c)
In this step (c), the transparent substrate 1 prepared in the step (b) is placed on an optical microscope 4 equipped with a slit light irradiation device 3, and the transparent substrate 1 is viewed from the rear or lower part of the transparent substrate 1. Light is passed through the slit plate 5 as shown in FIG.

The slit light irradiation device 3 mainly includes a light source 6 and a slit plate 5. Here, the light source 6 is for irradiating light from the back or lower part of the slit plate 5, and the light source 6 emits light of 200 to 10000 lux on the transparent substrate 1 when the slit plate 5 is not mounted. There is no particular limitation on the structure, light bulb and the like as long as the particles can be irradiated, but it is preferable that the amount of light (look) can be appropriately adjusted according to the size and properties of the fine particles. Further, it is desirable that the distance between the light source 6 and the transparent substrate 1 is in a range of 10 to 100 mm.

  The thickness and the shape of the outer peripheral edge of the slit plate 5 are not particularly limited, but a width (short side) of 0.5 to 10 mm and a length (long side) of 5 to 5 in the center thereof. It is desirable to use a slit with a 50 mm slit 5a. Here, the length of the slit portion is appropriately selected depending on the average particle size of the fine particles, the particle size of the coarse particles, and the like, and the width is determined by the brightness of the slit light appearing as an image on the internal surface of the fine particles. It is appropriately selected depending on whether the part is easy to see. For this reason, it is preferable that the width of the slit portion is adjustable. For this purpose, a mask plate (a plurality of slits having a desired size and having different slit sizes prepared in advance) is put on the upper portion of the slit plate 5 or the slit plate 5 is provided. It is desirable that the width can be adjusted by operating a slit width adjusting mechanism (for example, a slide plate) attached to the device. Further, a plurality of slit plates 5 having different size slits 5a may be prepared in advance, and an appropriate one may be selected and used.

  When the slit plate 5 is placed on the irradiation device 3 of the optical microscope, the long side direction of the slit 5a is perpendicular to the direction in which the field of view in the optical microscope is scanned, and the short side direction is the optical direction. It is desirable to arrange and arrange so as to be horizontal with the direction in which the field of view in the microscope is scanned.

  The optical microscope 4 is not particularly limited as long as the optical microscope can move the visual field in both directions of the X axis and the Y axis, but has a magnification of 100 to 3000 times, preferably 200 to 500 times. Desirably. In addition, it may have an external monitor.

Step (d)
In this step (d), while scanning the visual field in the optical microscope, a fine particle group of 10 to 200 million particles in the particle monolayer 2 irradiated with the slit light is closely examined, and the fine particles are examined. Coarse particles in the single particle layer 2 are detected by visually observing the bright portion 15 of the slit light appearing as an image on the inner surface, and the number thereof is counted.

  As shown in the schematic diagram of FIG. 1, the observer 7 looks into the viewfinder of the optical microscope 4 and scans the field of view of the optical microscope 4 while scanning 10 to 200 million particles in the particle monolayer 2. A fine particle group is closely inspected to detect and determine coarse particles (particles having a particle diameter of 1.2 times or more the average particle diameter) contained in the particle monolayer 2, thereby determining the content of the coarse particles. Is quantified. In this case, in the field of view of the optical microscope, the particle monolayer 2 in which the fine particles 13 are uniformly arranged can be seen, and the CV value of the fine particles 13 is as low as 10% or less. The coarse particles 14 that are not included can be easily detected and determined (determined) visually. That is, the coarse particles 14 having a particle diameter of 1.2 times or more of the average particle diameter are larger than the standard particles having a particle diameter of 1.0 times of the average particle diameter, and the area of the particle surface seen in the visual field of the optical microscope. Is 1.44 times or more, so that it can be easily determined from the difference in the area.

Further, when the microparticles 13 are transparent or translucent spherical particles, due to the lens effect of the spherical particles, as shown in FIG. The bright portion 15 appears, and the coarse particles 14 contained therein have a large size of the bright portion 15. Therefore, the coarse particles 14 can be easily detected and determined. In addition, it is possible to easily identify the coarse particles 14 contained in the minute particles 13 in a small amount based on the difference in brightness between the fine particles 13 that appear relatively dark and the coarse particles 14 that appear relatively bright. However, if the amount of light applied to these particles is too high or too low, it becomes difficult to see, and it becomes difficult to distinguish these particles. Therefore, it is desirable to appropriately adjust the amount of light.

  Further, this method can also be applied to fine particles whose surface has been subjected to a color treatment such as black. However, the amount of light applied to the microparticles depends on the light transmittance of the particles, but needs to be adjusted slightly higher.

  In order to shorten the operation time in this step, fine particles contained in the particle monolayer were closely inspected with a relatively small optical microscope magnification while scanning the visual field of the microscope, and in the process, relatively large particles were used. When a particle having a diameter is detected, it is desirable to stop the scanning and further increase the microscope magnification to determine whether the particle is the coarse particle. For example, when the microparticles are transparent particles having an average particle diameter of about 5 μm, the microparticles are closely examined at a magnification of about 200 times, and when relatively large particles are detected, the microscope magnification is increased to about 400 times. The determination of coarse particles can be performed.

In this manner, according to the method (1) for quantifying the minute amount of coarse particles, it is possible to easily quantify the coarse particles 14 contained in the minute amount in the minute particles 13 group.
Quantitative method of trace coarse particles (2)
The method for quantifying the second minute coarse particles according to the present invention,
Included in the group of microparticles having an average particle diameter in the range of 0.5 to 10 μm and a particle diameter variation coefficient (CV value) of 10% or less, the particle diameter of which is 1.2 times or more the average particle diameter. And a method for quantifying coarse particles having a content of 3000 ppb or less,
(A) a step of preparing a fine particle dispersion so that the particle concentration becomes 0.001 to 10% by weight; (b) applying, spraying or dropping the fine particle dispersion on the transparent substrate 1 to obtain the transparent Forming a particle monolayer 2 in which fine particles are arranged on a substrate 1;
(C) The transparent substrate 1 is placed on an optical microscope 4 equipped with a reverse slit light irradiation device 3, and a slit having a light shielding portion as shown in FIG. Irradiating the reverse slit light through the plate 5; and (d) observing the particle monolayer 2 irradiated with the reverse slit light while scanning the visual field in the optical microscope 4, and A fine particle group of 10 to 200 million particles is closely examined, and the size is determined by visually observing the shaded portion 16 on which the light-shielding portion 5d appearing as an image on the inner surface of the fine particle is projected. The present invention relates to a method for quantifying the coarse particles contained in a minute amount in the fine particle group by detecting coarse particles in the monolayer 2 and subjecting the particles to a step of counting the number thereof.

Each of the above steps is performed in the following manner.
Step (a)
In this step (a), an aqueous dispersion in which the fine particles are dispersed in water is prepared.

  The concentration (solid content concentration) of the fine particles contained in the dispersion varies depending on the method of forming the single particle layer 2, but is 0.001 to 10% by weight, preferably 0.01 to 5% by weight, and furthermore Preferably, it is in the range of 0.04 to 4% by weight. Here, when the particle concentration is less than 0.001% by weight, the particle monolayer 2 formed on the transparent substrate 1 is not dense, which causes a problem in quantitativeness of the coarse particles. On the other hand, if the particle concentration exceeds 10% by weight, the concentration is too high to form the particle monolayer 2 and at least a partly laminated particle film is formed to lower the light transmittance at the laminated portion. It becomes difficult to detect and determine the coarse particles present at this location.

It is desirable that the fine particle dispersion liquid contains a surfactant as necessary. The concentration of the surfactant at this time varies depending on the concentration of the fine particles, but is desirably in the range of 0.01 to 5% by weight, preferably 0.1 to 3% by weight. Here, when the concentration of the surfactant is less than 0.01% by weight, it is difficult to stably disperse the fine particles in a monodisperse manner, and thus a particle monolayer in which the fine particles are uniformly and regularly arranged is obtained. There may not be. Further, even if the concentration of the surfactant exceeds 5% by weight, the effect of monodispersing the particles is not further improved, and in some cases, the regularity of the fine particle arrangement of the particle monolayer is reduced. A problem may occur in the quantitativeness of the coarse particles.

  As such a surfactant, although it varies depending on the type of the fine particles, a conventionally known cationic surfactant, anionic surfactant, nonionic surfactant, and amphoteric surfactant are appropriately selected and used. be able to.

Further, in order to improve the dispersibility of the particles, it is desirable that the microparticle dispersion liquid be subjected to ultrasonic treatment in an ultrasonic bath for about 5 minutes before use.
Further, an evaporation rate of the dispersion medium may be adjusted by adding an organic solvent such as alcohol to water as needed. By doing so, the regularity and denseness of the obtained single particle layer 2 can be improved.

Step (b)
In this step (b), a particle monolayer in which fine particles are densely arranged is formed on the surface of the transparent substrate 1 from the fine particle dispersion prepared in the step (a).

  The method is not particularly limited as long as the dense particle monolayer 2 can be formed. For example, the transparent substrate 1 may be formed by a dropping method (casting method), a dipping method, a spinner method, a roll coater method, a printing method, or the like. A method of applying the composition to the surface and then drying the composition may be used. When carrying out this method, the transparent substrate 1 can be heated, cooled, or further dried under reduced pressure in order to adjust the evaporation rate of water or the dispersion medium. . At this time, if necessary, a flat plate may be pressed from above before or after the drying treatment to level the formed laminated particles to form single-layer particles (particle monolayer). Alternatively, a particle layer may be formed in advance on a sheet having excellent releasability by using the fine particle dispersion liquid and transferred to the surface of the transparent substrate.

However, it is not always easy to form the dense particle monolayer 2 on the transparent substrate 1.
Therefore, in the present invention, as shown in FIGS. 9 and 10, a metal mask 8 having an opening 9 of a desired size is mounted on the surface of the transparent substrate 1, and the transparent substrate 1 is attached as shown in FIG. Is placed at an angle of 3 to 7 °, preferably about 5 ° with respect to a horizontal plane, in a container 10 having a drain port 11 at the lower part, and then the container 11 is filled with water up to the surface of the transparent substrate 1. And the microparticle dispersion liquid is dropped on the water surface using a micro-ringing syringe, a dropper or a dispenser (these are not shown). Then, when the water surface on which the microparticles float is stopped, the water is discharged from the drain port 11. It is desirable to form a particle monolayer 2 (including 0.3 to 100 million fine particles) in which fine particles are regularly arranged on the transparent substrate 1 by draining water. Here, it is desirable that the dropping of the fine particle dispersion liquid is gently performed from a place near the water surface on the transparent substrate 1.

  It is preferable that the transparent substrate 1 on which the particle monolayer 2 thus obtained is arranged on the upper surface is naturally dried in a clean booth, but the hot substrate is kept at a temperature of 100 ° C. or lower. It may be dried on a plate. In this case, if the temperature of the hot plate is too high, the particle monolayer 2 formed on the transparent substrate 1 may become sparse, and the temperature must be appropriately selected.

The metal mask 8 is removed from the transparent substrate 1 before or after the drying process, so as not to affect the arrangement of the particle monolayer 2. Thereby, the particle monolayer 2 in which the fine particles are uniformly and regularly arranged can be formed on the transparent substrate 1. Here, the opening 9 of the metal mask 8 has a height of 2 to 10 cm and a width of 3 to 10 cm depending on the average particle diameter of the fine particles, the number of fine particles measured at a time, and the visual field of an optical microscope. Preferably, there is.

  If the single particle layer 2 is formed on the transparent substrate 1 without mounting the metal mask 8, a particle layer will be formed on the entire substrate. It is necessary to remove the portion corresponding to the mask in advance.

  As the transparent substrate 1, a transparent substrate such as a glass plate or a plastic plate is used. The transparent substrate 1 preferably has a clean substrate surface, and can be used by washing the surface with a conventionally known method, for example, using an organic solvent, pure water, steam, or the like, and then drying. Further, the surface of the transparent substrate 1 may be subjected to a hydrophilic treatment or a hydrophobic treatment. For example, when the microparticles are hydrophilic, a hydrophilized substrate is preferable, and when the microparticles are hydrophobic, a hydrophobized substrate is preferable. The use of such a surface-treated transparent substrate improves the adhesion between the fine particles and the adhesion between the substrate and the fine particles, so that a regular and dense particle monolayer is formed on the surface. As a result, the accuracy of quantitative determination of coarse particles is improved.

  The size of the transparent substrate 1 varies depending on the average particle size of the fine particles, the number of fine particles measured at one time, the visual field of an optical microscope, the size of the opening 9 of the metal mask 8, and the like. It is preferable that the height is 5 to 15 cm and the width is 5 to 15 cm. It is desirable that the metal mask 8 can be mounted on the transparent substrate 1. However, the four corners may be fixed with clips or the like.

  Further, a jig 12 for mounting the transparent substrate 1 on which the metal mask 8 is mounted is installed in the container 10, and the transparent substrate 1 mounted on the jig 12 is inclined. It is preferable that the angle be adjusted to the above range.

Step (c)
In this step (c), the transparent substrate 1 prepared in the step (b) is placed on an optical microscope 4 equipped with a reverse slit light irradiation device 3, and the transparent substrate 1 is placed on the rear or lower part of the transparent substrate 1. Light (inverse slit light) passing through a slit plate 5 having a light-shielding portion 5d as shown in FIG.

  The reverse slit light irradiation device 3 mainly includes a light source 6 and a slit plate 5. Here, the light source 6 is for irradiating light from the back or lower part of the slit plate 5, and the light source 6 emits light of 200 to 10000 lux on the transparent substrate 1 when the slit plate 5 is not mounted. There is no particular limitation on the structure, light bulb and the like as long as the particles can be irradiated, but it is preferable that the amount of light (look) can be appropriately adjusted according to the size and properties of the fine particles. Further, it is desirable that the distance between the light source 6 and the transparent substrate 1 is in a range of 10 to 100 mm.

  The thickness and the shape of the outer peripheral edge of the slit plate 5 are not particularly limited, but the outer peripheral edge portion 5b (FIG. 4 or FIG. 5) having an open central portion is provided. Desirably, it is constituted by a light-shielding portion 5d (FIGS. 6 to 8) fixed or suspended to the outer peripheral edge portion 5b through or near the center of the opening 5c inside the portion.

The opening 5c in the outer peripheral edge portion 5b is circular and has a diameter of 10 to 100 mm.
Is desirably within the range. Here, the opening 5c is necessary for irradiating the particle monolayer 2 with light, and the diameter thereof is whether or not the fine particles and the coarse particles can be easily distinguished. It is appropriately selected depending on whether or not the shaded portion 16 on which the light-shielding portion 5d appearing as an image on the inner surface is projected is easy to see. For this reason, it is preferable that the size of the opening 5c can be adjusted. For this purpose, a mask plate having a desired size of opening at the center thereof (a plurality of mask plates having different sizes of openings prepared in advance) is placed on the slit plate 5 for adjustment. Is desirable. Furthermore, a plurality of slit plates 5 having openings 5c of different sizes may be prepared in advance, and an appropriate one may be selected and used.

  Further, the length (long side) of the light-shielding portion 5d varies depending on the diameter of the opening 5c, but the width (short side) is desirably in the range of 1 to 30 mm. Here, the width of the light-shielding portion 5d is appropriately selected depending on the average particle size of the fine particles, the particle size of the coarse particles, and the like. Is appropriately selected depending on whether or not the shaded portion 16 on which is projected is easy to see. For this reason, it is preferable that the width of the light shielding portion 5d is adjustable. For this purpose, it is preferable that the light-shielding portion 5d be detached and replaced with a member having a desired width. More specifically, the light-shielding portion 5d is formed at the upper and lower ends of the outer peripheral edge portion 5b as shown in FIG. Both ends 5f of the light shielding portion 5d as shown in FIG. 7 or FIG. 8 can be fitted into the holes 5e, or both ends 5f of the light shielding portion 5d can be attached to the upper and lower ends of the outer peripheral edge portion 5b as shown in FIG. It is desirable to have a structure. Further, a plurality of slit plates 5 to which light-shielding portions 5d having different widths are attached may be prepared in advance, and an appropriate one may be selected and used.

  When the slit plate 5 is mounted on the irradiation device 3 of the optical microscope, the long side direction of the light shielding portion 5d is perpendicular to the direction in which the visual field in the optical microscope is scanned, and the short side direction is the short side direction. It is desirable to arrange the optical microscope so as to be horizontal with the scanning direction of the visual field in the optical microscope.

  The optical microscope 4 is not particularly limited as long as the optical microscope can move the visual field in both directions of the X axis and the Y axis, but has a magnification of 100 to 3000 times, preferably 200 to 500 times. Desirably. In addition, it may have an external monitor.

Step (d)
In this step (d), while scanning the visual field in the optical microscope, a fine particle group of 10 to 200 million particles in the particle single layer 2 irradiated with the reverse slit light is scrutinized. The size of the monolayer 2 is detected by visually observing the shaded portion 16 on which the light-shielding portion 5d appearing as an image on the inner surface of the particle is projected, and the number thereof is counted.

  As shown in the schematic diagram of FIG. 1, the observer 7 looks into the viewfinder of the optical microscope 4 and scans the field of view of the optical microscope 4 while scanning 10 to 200 million particles in the particle monolayer 2. A fine particle group is closely inspected to detect and determine coarse particles (particles having a particle diameter of 1.2 times or more the average particle diameter) contained in the particle monolayer 2, thereby determining the content of the coarse particles. Is quantified. In this case, in the field of view of the optical microscope, the particle monolayer 2 in which the fine particles 13 are uniformly arranged can be seen, and the CV value of the fine particles 13 is as low as 10% or less. The coarse particles 14 that are not included can be easily detected and determined (determined) visually. That is, the coarse particles 14 having a particle diameter of 1.2 times or more of the average particle diameter are larger than the standard particles having a particle diameter of 1.0 times of the average particle diameter, and the area of the particle surface seen in the visual field of the optical microscope. Is 1.44 times or more, so that it can be easily determined from the difference in the area.

  When the microparticles 13 are transparent or translucent spherical particles, due to the lens effect of the spherical particles, as shown in FIG. An elliptical shaded portion 16 appears, and coarse particles 14 contained therein have an increased size of the shaded portion 16, so that the coarse particles 14 can be easily detected and determined. Further, by comparing the sizes of the shaded portions 16, it is possible to easily determine the coarse particles 14 contained in a minute amount in the group of the fine particles 13. However, if the amount of light applied to these particles is too high or too low, it becomes difficult to see, and it becomes difficult to distinguish these particles. Therefore, it is desirable to appropriately adjust the amount of light.

  In order to shorten the operation time in this step, fine particles contained in the particle monolayer were closely inspected with a relatively small optical microscope magnification while scanning the visual field of the microscope, and in the process, relatively large particles were used. When a particle having a diameter is detected, it is desirable to stop the scanning and further increase the microscope magnification to determine whether the particle is the coarse particle. For example, when the microparticles are transparent particles having an average particle diameter of about 5 μm, the microparticles are closely examined at a magnification of about 200 times, and when relatively large particles are detected, the microscope magnification is increased to about 400 times. The determination of coarse particles can be performed.

Thus, according to the method (2) for quantifying coarse particles according to the present invention, it is possible to quantify the coarse particles 14 contained in a minute amount in the group of fine particles 13.
In this quantification method, it is extremely easy to discriminate the fine particles 13 and the coarse particles 14 from the above-described method for quantifying coarse particles (1), and the burden on the eyes of the observer is also reduced. It is desirable to employ this method because it is mitigated.

Next, the microparticle product according to the present invention will be described more specifically.
The microparticle product according to the present invention is included in the group of microparticles 13 and quantifies the coarse particles 14 having a particle diameter of 1.2 times or more the average particle diameter of the microparticles, and if necessary, By subjecting all or part of the fine particles to a classification operation for separating coarse particles, quality control was performed such that the content of the coarse particles 14 contained in the group of fine particles 13 was 500 ppb or less. It is characterized by things.

Examples of the fine particle product include spacer particles for a liquid crystal display cell (such as a spacer for a sealing portion and an in-plane spacer), conductive particles, insulating particles, and fine particles used as semiconductor particles. Specifically, metal particles such as Au, Ag, Cu, Pt, Pd, Co, and Ni used as semiconductor particles such as photocatalysts, catalyst particles or conductive particles, and two or more of these metals or other metal components Composite metal particles (including alloy fine particles), SiO ₂ , Al ₂ O ₃ , ZrO ₂ , SiO ₂ —Al ₂ O ₃ , TiO ₂ , ZnO, SnO ₂ , La ₂ O ₃ ,
Examples include inorganic oxide particles such as In ₂ O ₃ , organic resin particles, and organic / inorganic composite particles. Further, conductive particles having the surface of the insulating particles coated with a conductive component, insulating particles having the surface of the conductive particles coated with an insulating component, and inorganic oxide particles containing a doping material. Is also good.

  When the content of the coarse particles contained in the fine particle product is 500 ppb or less, the above-mentioned damage to the electrodes, and further, problems such as poor insulation and short-circuiting do not substantially occur or are extremely small, so that the reliability is low. And various electric appliances with high prices can be manufactured. That is, when the microparticle product is used, a high product yield can be obtained when manufacturing various electric appliances.

The microparticle product can be suitably used as spacer particles for a liquid crystal display cell. Further, when the fine particle product is used as the spacer particles, the content of the coarse particles contained in the fine particle group is preferably 200 ppb or less. The fine particle product having a small number of coarse particles can be suitably used as a spacer particle for a liquid crystal display cell having a small cell gap and a wiring width of 10 μm or less, and more preferably 5 μm or less. In addition, the liquid crystal display device manufactured by using this is excellent in its reliability, not only without display unevenness, but also capable of high-density, high-definition display, and excellent in high-speed response. .

  Examples of such spacer particles include, among the above-mentioned particles, organic resin particles such as polystyrene, inorganic oxide particles such as silica, and organic-inorganic composite particles obtained by hydrolyzing an organic silicon compound such as polyorganosiloxane. It is desirable to use Among these, as the sealing spacer used in the sealing portion, particles having a high elasticity value, for example, silica particles, organic / inorganic composite particles, and the like are preferably used, and as the in-plane spacer of the display cell surface, Organic resin particles, organic-inorganic composite particles, and the like having moderate elasticity are preferably used.

Further, the shape of the spacer particles is preferably spherical or spherical.
In the quantification method according to the present invention, the coarse particles 14 contained in the group of fine particles 13 are quantified, and if the content exceeds a desired value of 500 ppb or less, the fine particles It is necessary to produce a fine particle product which is appropriately quality-controlled by subjecting all or a part of the product to a classification operation for separating coarse particles to remove the coarse particles.

  As the method, conventionally known classification methods, for example, elutriation classification, sedimentation classification, elutriation classification, micromesh classification, and the like can be used. Among them, in the present invention, a sedimentation classification method of adding the fine particles to water or an aqueous dispersion medium containing an organic solvent such as alcohol, and separating or separating the coarse particles depending on the difference in sedimentation speed of the particles. It is desirable to adopt it.

As a result, it is possible to obtain a fine particle product in which the content of the coarse particles is controlled within a desired range and quality control is appropriately performed.
In addition to this, in the present invention, using the above quantification method, quantified coarse particles having a particle diameter of 1.2 times or more the average particle diameter of the fine particles contained in the fine particle group, Separating the coarse particles from all or a part of the fine particles by the classification operation as necessary, a method for producing a fine particle product in which the content of the coarse particles contained in the fine particle group is 500 ppb or less. provide. The method is as described above.

Next, the liquid crystal display device according to the present invention will be specifically described.
In the liquid crystal display device according to the present invention, the fine particle product is used as an in-plane spacer or a spacer for a sealing portion of a liquid crystal display cell.

  The configuration of the liquid crystal display device is not particularly limited as long as it is conventionally known. For example, in a TFT liquid crystal display device, (a) thin film transistors (hereinafter, referred to as TFTs) arranged in a matrix are used. A TFT array substrate in which a rubbed polyimide alignment film is formed on a glass substrate having: (b) a counter substrate in which a light-shielding black matrix, a color filter, a tin-doped indium oxide film, and a rubbed polyimide alignment film are sequentially laminated; c) A liquid crystal display cell containing a TN liquid crystal or the like sealed between these substrates and other components.

Further, in the liquid crystal display device, usually, in manufacturing the liquid crystal display device, in order to make the thickness of the liquid crystal layer inside the liquid crystal display cell uniform, a fine particle product having a uniform particle diameter is formed by using an in-plane spacer between the electrodes of the liquid crystal display cell. It is known to intervene as a spacer for the seal portion at the peripheral portion of the electrode. Here, the average particle diameter of the in-plane spacer and the seal portion spacer may be the same or different, but regarding the type, a fine particle product such as organopolysiloxane is used as the in-plane spacer. It is desirable to use a fine particle product such as SiO ₂ for the spacer for the seal portion.

  Furthermore, it is desirable that the microparticle product used as the seal portion spacer is screen-printed on a peripheral portion of the counter substrate by obtaining a seal material obtained by adding the microparticle product to a sealing adhesive and stirring until uniformity. In addition, it is preferable that the microparticle product used as the in-plane spacer is added to an organic solvent such as ethyl alcohol and then sufficiently stirred to spray a dispersion obtained on the counter substrate. Here, it is necessary to spray the dispersion liquid on a portion where the seal material is not printed.

  Thus, the liquid crystal display device manufactured using the fine particle product according to the present invention includes the fine particle product used as a spacer for a seal portion or an in-plane spacer in which the coarse particles are 500 ppb or less, preferably 200 ppb or less. Since only the following components are included, there is almost no damage to the electrodes and no disconnection of the wiring in the liquid crystal display cell constituting the liquid crystal display cell, and the liquid crystal display cell is extremely reliable.

[Example]
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.
(Preparation example of microparticle group)
Preparation of Microparticle Group (A) A mixed solution of 487 g of ethyl alcohol and 389 g of water was maintained at a temperature of 35 ° C. while stirring, and 71.7 g of ammonia gas was dissolved in the mixed solution. To this mixed solution, 17.4 g of an aqueous solution of ethyl silicate having a concentration of 28% by weight as SiO ₂ was added, and thereafter stirring was continued for 2 hours to prepare a dispersion of seed particles having a concentration of 0.5% by weight as SiO ₂ . Then, 3.3 g of a 0.03 wt% NaOH aqueous solution was immediately added to obtain a heel sol (A) in which seed particles were dispersed in a water-alcohol dispersion.

  Then, a mixed solution of 455 g of ethyl alcohol and 886 g of water and 570 g of an aqueous solution of ethyl silicate having a concentration of 28% by weight were simultaneously added to 97 g of the heel sol (A) under stirring at a temperature of 35 ° C. while maintaining a pH of 11.5 with ammonia gas. Added slowly over time. After all of these were added, 103 g of an aqueous solution in which 1 g of NaOH was dissolved was added, and this was maintained at a temperature of 70 ° C. for 2 hours. The particles were separated from the dispersion, dried at a temperature of 110 ° C., and dried to form fine particles of silica. Group (A) was prepared. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (B) The fine particle group (A) obtained in the preparation of the fine particle group (A) was calcined at a temperature of 350 ° C. for 3 hours to prepare a black fine particle group (B). . Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (C) In the preparation of the fine particle group (A), the heel sol obtained by using the seed particle dispersion having a concentration of 0.2% by weight as SiO ₂ had a concentration of 28% by weight. A microparticle group (C) was prepared in the same manner except that 570 g of an ethyl silicate aqueous solution was added over 30 hours. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (D) In the preparation of the fine particle group (C), the fine particle group (D) was prepared in the same manner except that 80 g of a 28% by weight aqueous solution of ethyl silicate was added to the heel sol over 10 hours. ) Was prepared. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (E) In the preparation of the fine particle group (A), a heel sol having a concentration of 28% by weight was added to a heel sol obtained using a seed particle dispersion having a concentration of 0.2% by weight as SiO ₂ . Fine particle group (E) was prepared in the same manner except that 2,700 g of an ethyl silicate aqueous solution was added over 150 hours. Table 1 shows the average particle size, density, and CV value of the particles.
Preparation of Fine Particle Group (F) A solution (solution A) was prepared by dissolving 8 g of methyltrimethoxysilane and 8 g of tetramethoxysilane in 350 g of ethanol. On the other hand, a mixed solution (solution B) of 6 g of pure water, 78 g of 28% aqueous ammonia, and 350 g of ethanol was prepared.

  Next, the solution A and the solution B were mixed and stirred at a temperature of 20 ° C. for 3 hours to carry out hydrolysis and polycondensation of methyltrimethoxysilane and tetramethoxysilane. Further, 3.3 g of a 1% by weight aqueous solution of potassium hydroxide was added to stabilize the seed. At this time, the pH of the aqueous solution was 12.

  The seed particle dispersion was heated and concentrated until the obtained seed particle dispersion reached 160 g, and then alkali and ammonia contained in the dispersion were removed using 10 cc of a cation exchange resin. 5000 g of pure water and 250 g of butanol were added to the seed particle dispersion. The seed particle dispersion thus diluted is cooled to a temperature of 0 ° C., and while maintaining the temperature, 100 g of methyltrimethoxysilane is added to the seed particle dispersion at a rate of 0.005 g / pure water-g · hour. At the same time, the pH of the seed particle dispersion was maintained at 8.5 while simultaneously adding an aqueous ammonia solution having a concentration of 0.028% at an addition rate of about 0.012 / pure water-g · hour. Methyltrimethoxysilane was hydrolyzed and polycondensed on the seed particles to grow the seed particles. Next, after stirring at a temperature of 20 ° C. for 2 hours, the particles were heated to a temperature of 80 ° C. and ripened for 5 hours.

  The particles thus obtained were separated from the dispersion and dried at a temperature of 110 ° C. to prepare a fine particle group (F) composed of an organopolysiloxane. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (G) In the preparation of the fine particle group (F), 15 g of methyltrimethoxysilane was added dropwise to the seed particle dispersion at an addition rate of 0.00075 g / pure water-g · hour, and further simultaneously. A microparticle group (G) composed of an organopolysiloxane was prepared in the same manner except that an aqueous ammonia solution having a concentration of 0.004% was added at an addition rate of about 0.012 g / pure water-g · hour. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Microparticle Group (H) In the preparation of the microparticle group (F), 2300 g of methyltrimethoxysilane was added dropwise to the seed particle dispersion at an addition rate of 0.005 g / pure water-g · hour, and further simultaneously. A microparticle group (H) composed of an organopolysiloxane was prepared in the same manner except that an aqueous ammonia solution having a concentration of 0.028% was added at an addition rate of about 0.012 / pure water-g · hour. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (R1) In the preparation of the fine particle group (A), a fine particle group made of silica was prepared in the same manner except that the mixed solution and the ethyl silicate aqueous solution were gradually added simultaneously over 5 hours.
R1) was prepared. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (R2) In the preparation of the fine particle group (A), silica particles were formed in the same manner except that a seed particle dispersion having a concentration of 1.0% by weight as SiO ₂ was prepared and used. A microparticle group (R2) was prepared. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Fine Particle Group (R3) In the preparation of the fine particle group (D), the fine particle group (R3) was prepared in the same manner except that 80 g of an aqueous solution of ethyl silicate having a concentration of 28% by weight was added to the heel sol over 2 hours. ) Was prepared. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Microparticle Group (R4) In the preparation of the microparticle group (E), the heel sol obtained by using the seed particle dispersion having a concentration of 1.0% by weight as SiO ₂ had a concentration of 28% by weight. A microparticle group (R4) was prepared in the same manner except that 2700 g of an ethyl silicate aqueous solution was added over 10 hours. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Microparticle Group (R5) In the preparation of the microparticle group (F), methyltrimethoxysilane was added dropwise to the seed particle dispersion at a rate of 0.05 g / pure water-g · hour, and at the same time A microparticle group (R5) was prepared in the same manner except that an aqueous ammonia solution having a concentration of 0.028% was added at an addition rate of about 0.12 / pure water-g · hour. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Microparticle Group (R6) In the preparation of the microparticle group (G), 15 g of methyltrimethoxysilane was added dropwise to the seed particle dispersion at an addition rate of 0.0075 g / pure water-g · hour. At the same time, a microparticle group (R6) composed of an organopolysiloxane was prepared in the same manner except that an aqueous ammonia solution having a concentration of 0.004% was added at an addition rate of about 0.12 g / pure water-g · hour. Table 1 shows the average particle size, density, and CV value of the particles.

Preparation of Microparticle Group (R7) In the preparation of the microparticle group (H), 2300 g of methyltrimethoxysilane was added dropwise to the seed particle dispersion at an addition rate of 0.05 g / pure water-g · hour. At the same time, a microparticle group (R7) composed of an organopolysiloxane was prepared in the same manner except that an aqueous ammonia solution having a concentration of 0.028% was added at an addition rate of about 0.12 / pure water-g · hour. Table 1 shows the average particle size, density, and CV value of the particles.

Hereinafter, an example according to the method (1) for quantifying the minute amount of coarse particles will be described.
Preparation of fine particle dispersion [Step (a)]
0.05 g of each of the microparticle groups (A), (B) and (R3) was obtained, and 1.0% by weight of a surfactant (manufactured by Kao Corporation: Clean-Thru) placed in a 10 ml screw tube was used. ) Was dispersed in 5 g of an aqueous solution containing (A), (B) and (R3), each containing 1.0% by weight (solid content) of fine particles.

Next, in order to enhance the uniformity of dispersion of the fine particles, ultrasonic treatment was performed for about 5 minutes in an ultrasonic tank (manufactured by Iuchi Seieido Co., Ltd .: US-1).
Preparation of Particle Monolayer [Step (b)]
Three glass transparent substrates (width 10 cm x height 10 cm x thickness 1.1 mm) are prepared, and a metal mask (length 10 cm x width 10 cm x width 10 cm x width 10 cm x) having an opening of width 6 cm x length 4.5 cm is prepared on these. (Thickness: 0.2 mm).

  Next, the transparent substrate is placed on a jig disposed in a container (diameter 25 cm × height 25 cm) having a drain port at a lower portion at an inclination angle of 5 ° with respect to a horizontal plane, and then the container is placed in the container. Is filled with water up to the surface (about 2 cm) of the transparent substrate, and the microparticle dispersions (A), (B), and (R3) are filled on the surface of the water with pure water and washed with pure water at a volume of 1 ml. Was slowly added dropwise. Here, the dropping of the fine particle dispersion liquid was gently performed from a place near the water surface on the transparent substrate. Next, after the dropping was completed, when the water surface on which the fine particles floated stopped, water was drained from the drain port, and the transparent substrate was taken out.

  Next, the transparent substrate is placed in a clean booth and air-dried. To some extent, when the drying has proceeded, the metal mask is removed from the transparent substrate and placed on a hot plate at a temperature of about 100 ° C. A drying treatment was performed for about 5 minutes to obtain transparent substrates (A), (B) and (R3) having the microparticles arranged on the surface.

Irradiation of slit light [Step (c)]
A slit plate (5 cm wide × 5 cm long × 0.2 mm thick) having a slit of 30 mm long × 3 mm wide provided in the center is prepared, and this is used as a slit light irradiation device for an optical microscope (Olympus: MX50). It was installed in.

  Next, the transparent substrates (A), (B) and (R3) were sequentially mounted on the optical microscope, and irradiated with light passing through the slit plate from the back (lower) of the transparent substrate. Further, the magnification and the irradiation light amount of the optical microscope were changed so that the bright part of the slit light appearing as an image on the inner surface of the fine particles was adjusted to be clearly visible. The distance between the light source and the transparent substrate was about 50 mm.

  As a result, the microscope magnification suitable for the determination of the coarse particles was about 400 times, but the irradiation light amount, the transparent particles on the transparent substrate with the slit plate removed, the transparent particles on the surface The arrangement of the transparent substrates (A) and (R3) was about 4000 lux, and the arrangement of the transparent substrate (B) having black particles arranged on the surface was about 7000 lux.

Detection and determination of coarse particles [Step (d)]
While scanning the field of view in the optical microscope, the microparticle group in the particle monolayer arranged on the transparent substrates (A), (B), and (R3) irradiated with the slit light is a microscope of about 200 times magnification. The fine particles were closely inspected, and the bright portions of the slit light appearing as an image on the inner surface of the fine particles were visually observed, coarse particles contained in the particle monolayer were detected and determined, and the number thereof was counted. In the detection process, if particles that may correspond to the coarse particles are found, the magnification of the optical microscope is increased to about 400 times, and the particle size of the coarse particles is 1.2 times the average particle size. It was visually determined whether the particles had twice the particle diameter. The measurement time was 1-2 hours per one transparent substrate.

  Further, the number of the fine particles measured here was calculated using the above-described formula (3), and the content (ppb) of the coarse particles was obtained. The results (values rounded to the required number of digits) are shown in Table 2.

  In addition, it turned out that this quantification method (1) can be applied to a fine particle whose surface has been subjected to a color treatment such as black color without any particular problem.

Hereinafter, an example according to the method (2) for quantifying the minute amount of coarse particles will be described.
Preparation of fine particle dispersion [Step (a)]
An aqueous solution containing 1.0% by weight of a surfactant (manufactured by Kao Corporation: clean through) placed in a 10-ml screw tube was obtained in an amount of 0.05 g, each of the microparticle groups (A) to (R7). Fine particle dispersions (A) to (R7) containing 1.0% by weight (solid content concentration) of fine particles dispersed in 5 g were prepared.

Next, in order to enhance the uniformity of dispersion of the fine particles, ultrasonic treatment was performed for about 5 minutes in an ultrasonic tank (manufactured by Iuchi Seieido Co., Ltd .: US-1).
Preparation of Particle Monolayer [Step (b)]
Fifteen transparent glass substrates (width 10 cm × length 10 cm × thickness 1.1 mm) are prepared, and a metal mask (length 10 cm × width 10 cm × width 10 cm × width 10 cm × width) having an opening of width 6 cm × length 4.5 cm is placed on these. (Thickness: 0.2 mm).

  Next, the transparent substrate is placed on a jig disposed in a container (diameter 25 cm × height 25 cm) having a drain port at a lower portion at an inclination angle of 5 ° with respect to a horizontal plane, and then the container is placed in the container. Is filled with water up to the surface of the transparent substrate (about 2 cm), and the fine particle dispersions (A) to (R7) are slowly filled in the water surface with a micro-ringing machine having an inner volume of 1 ml washed with pure water. Was dropped. Here, the dropping of the fine particle dispersion liquid was gently performed from a place near the water surface on the transparent substrate. Next, after the dropping was completed, when the water surface on which the fine particles floated stopped, water was drained from the drain port, and the transparent substrate was taken out.

  Next, the transparent substrate is placed in a clean booth and air-dried. To some extent, when the drying has proceeded, the metal mask is removed from the transparent substrate and placed on a hot plate at a temperature of about 100 ° C. A drying treatment was performed for about 5 minutes to obtain transparent substrates (A) to (R7) in which the fine particles were arranged on the surface.

Irradiation of slit light [Step (c)]
A slit plate (horizontal) formed of an outer peripheral portion having a circular opening having a diameter of 3 cm at the center, and a light shielding portion having a width of 5 mm attached to the upper and lower ends of the outer peripheral portion through the center of the opening. 5 cm × 5 cm × 0.2 mm in thickness) was prepared, and set in a reverse slit light irradiation device of an optical microscope (MX50, manufactured by Olympus Corporation).

  Next, the transparent substrates (A) to (R7) were sequentially placed on the optical microscope and irradiated with light (reverse slit light) passing through the slit plate from the back (lower part) of the transparent substrate. Further, the magnification of the optical microscope and the amount of irradiation light were changed so that the shaded portion projected as the image on the inner surface of the microparticle and projected as the image was clearly seen. However, in the transparent substrate (B) in which black particles were arranged on the surface, the shaded portion was difficult to see, so the amount was adjusted by increasing the amount of irradiation. The distance between the light source and the transparent substrate was about 50 mm.

  Further, regarding the transparent substrates (E), (H), (R4) and (R7) in which transparent particles having a relatively large average particle diameter are arranged on the surface, the shaded portions were slightly hard to see, so The same observation was performed after removing the light-shielding part attached to the plate and replacing it with a 10 mm-wide one.

As a result, the microscope magnifications suitable for the determination of coarse particles were both about 400 times, but the irradiation light amount was compared with the average particle diameter on a transparent substrate with the slit plate removed. The transparent substrates (A), (C), (D), (F), (G), (R1), (R2), (R3), (R5), and the transparent substrates having extremely small transparent particles arranged on the surface. (R6) is about 5,000 lux, and the transparent substrates (E), (H), (R4) and (R7), in which transparent particles having a relatively large average particle diameter are arranged on the surface, have about 3000 lux. there were. The amount of light applied to the transparent substrate (B) having the black particles arranged on the surface was about 6000 lux on the transparent substrate with the slit plate removed.

Detection and determination of coarse particles [Step (d)]
While scanning the field of view in the optical microscope, the fine particle group in the particle monolayer arranged on the transparent substrates (A) and (B) to (R7) irradiated with the reverse slit light is approximately 200 times. Scrutinized under a microscope magnification, the light-shielding portion appearing as an image on the inner surface of the microparticle is visually observed as a shaded portion projected thereon, and coarse particles contained in the particle monolayer are detected and determined, and the number thereof is counted. . In the detection process, if particles that may correspond to the coarse particles are found, the magnification of the optical microscope is increased to about 400 times, and the particle size of the coarse particles is 1.2 times the average particle size. It was visually determined whether the particles had twice the particle diameter. The measurement time was 1-2 hours per one transparent substrate.

  Further, the number of the fine particles measured here was calculated using the above-described formula (3), and the content (ppb) of the coarse particles was obtained. The results (values rounded to the required number of digits) are shown in Table 2.

  In addition, it turned out that this quantification method (2) is easier to distinguish the coarse particles than the quantification method (1).

  As is clear from the above results, the content of the coarse particles contained in the fine particle groups (A) to (H), (R1) and (R6) is 500 ppb or less, so that the present invention Such a microparticle product can be used as it is. In particular, the fine particle groups (A) to (H) can be suitably used as spacer particles because the number of coarse particles contained therein is 200 ppb or less.

However, the other fine particle groups (R2) to (5) and (R7) cannot be used as they are because the content of the coarse particles exceeds 500 ppb.
Therefore, the fine particles (R2) selected from these were separated into coarse particles contained in the fine particles using the sedimentation classification method described below.

100 g of the fine particles (R2) were placed in a beaker (2000 ml in internal volume) containing 1000 ml of coarse-particle classified pure water, and a uniform dispersion was prepared using a magnetic stirrer.

  Next, the dispersion liquid is put into a separating funnel (internal volume: 1000 ml) with a cock at the lower part, and is allowed to stand for about 30 minutes. Then, the cock is opened to position the lower part of the separating funnel. 20 ml of the dispersion was discharged, and a part of the coarse particles contained in the fine particles (sedimented at the lower part of the separating funnel) was separated.

Further, the dispersion remaining in the separating funnel was again transferred to the beaker, and a uniform dispersion was obtained using a magnetic stirrer.
Next, the dispersion was placed in the separating funnel and allowed to stand for about 60 minutes, and then the cock was opened to discharge 20 ml of the dispersion located below the separating funnel. Separation of the particles was performed.

Further, the dispersion remaining in the separating funnel was again transferred to the beaker, and a uniform dispersion was obtained using a magnetic stirrer.
Next, the dispersion was placed in the separating funnel and allowed to stand for about 120 minutes, and then the cock was opened to discharge 20 ml of the dispersion located at the lower part of the separating funnel. Separation of the particles was performed.

Next, the dispersion remaining in the separating funnel was transferred to a stainless steel pad and dried at 110 ° C. for 15 hours.
The microparticle group (S) thus obtained was measured in the same manner as in Example 2, and the content of the coarse particles contained in the microparticle group was detected and determined. there were.

Thus, according to the present invention, it is possible to always provide a fine particle product whose quality is controlled such that the content number of the coarse particles is 500 ppb or less.
[Comparative Example 1]
The transparent substrate (A) prepared in the same manner as in Example 2 was placed on an optical microscope having no slit plate, and the coarse particles were detected in the same manner as in Example 2. Was. Here, the magnification and the irradiation light amount of the optical microscope were the same as in Example 2.

  However, the fine particles in the monolayer of particles arranged on the transparent substrate are difficult to see, and it has been found that it is not easy to detect and determine the coarse particles from this. Further, it has been found that even if the coarse particles can be detected, the measurement takes a considerable amount of time and cannot be accurately quantified.

[Comparative Example 2]
0.6 g of the microparticle group (A) was obtained and dispersed in 5 g of an aqueous solution containing 1.0% by weight of a surfactant (manufactured by Kao Corporation: clean through) placed in a screw tube having a volume of 10 ml. Fine particle dispersions (A1) and (A2) containing 12.0% by weight (solid content) of fine particles were prepared. Next, in order to improve the uniformity of dispersion of the fine particles, ultrasonic treatment was performed for about 5 minutes in an ultrasonic bath (manufactured by Iuchi Seieido Co., Ltd .: US-1).

Next, the fine particle dispersion (A1) was applied on the transparent substrate used in Example 2 by using a spinner method. Further, the transparent substrate is placed in a clean booth and naturally dried, and to a certain extent, when the drying has progressed, the substrate is placed on a hot plate at a temperature of about 100 ° C., and further subjected to a drying treatment for about 5 minutes. A transparent substrate (A1) having the surface of the fine particle layer formed thereon was obtained.

  However, it was found that the layer of the fine particles formed on the transparent substrate (A1) was not necessarily a single particle layer but was laminated in many parts. In addition, it was found that even a single particle layer was not regularly arranged.

Further, the fine particle dispersion (A2) was dropped on a transparent substrate provided with the metal mask in the same manner as in Example 2, and the transparent substrate was taken out of the container.
Next, the transparent substrate is placed in a clean booth and air-dried. To some extent, when the drying has proceeded, the metal mask is removed from the transparent substrate and placed on a hot plate at a temperature of about 100 ° C. A drying treatment was performed for about 5 minutes to obtain a transparent substrate (A2) having the fine particle layer formed on the surface thereof.

  However, because the solid content concentration of the fine particle dispersion liquid (A2) was as high as 12.0% by weight, the layer of the fine particles formed on the transparent substrate (A2) is not necessarily a single particle layer. However, it was found that the layers were partially laminated.

Preparation of Liquid Crystal Display Cell A rubbed polyimide alignment film was formed on a glass substrate having thin film transistors (hereinafter referred to as TFTs) arranged in a matrix, and six TFT array substrates of one of the liquid crystal display cells were formed. . Further, another six opposite substrates in which a black matrix for light shielding, a color filter, a tin-doped indium oxide film, and a rubbed polyimide alignment film were sequentially laminated were prepared.

  Next, in 100 g of a sealing adhesive (manufactured by Mitsui Chemicals, Inc .: Structbond XN-5A-C), a group of microparticles (Example 2) in which the content of coarse particles was determined to be the value shown in Table 2 ( A) 2.4 g was added, and the mixture was stirred until it became uniform, thereby preparing a sealing material (A) containing a spacer for a sealing portion according to the present invention. Similarly, the fine particle groups (C), (D), and (E) in which the content number of the coarse particles was determined to be the values shown in Table 2 in Example 2 and the fine particle group prepared in Example 3 Using (S), sealing materials (C), (D), (E) and (S) were prepared.

  Further, to 1000 cc of ethyl alcohol, 0.01 g of the fine particle group (F) whose amount of coarse particles determined to be the value shown in Table 2 in Example 2 was added, and the mixture was sufficiently stirred and referred to in the present invention. A dispersion (F) containing an in-plane spacer was prepared. Similarly, the dispersions (B), (G) were obtained using the fine particle groups (B), (G), and (H) in Example 2 in which the number of coarse particles was determined to be the value shown in Table 2. ) And (H) were prepared.

Next, the sealing material (A) was screen-printed on the periphery of the counter substrate.
Further, the dispersion liquid (F) was sprayed onto the counter substrate placed in a spray chamber maintained at a temperature of 60 ° C. and a humidity of 3%. The spraying was performed on a portion where the sealing material was not printed.

Next, the counter substrate was dried at a temperature of 90 ° C. for 30 minutes, and then bonded to the TFT array substrate under the conditions of a temperature of 150 ° C. and a pressure of 1.5 kgf / cm ² so as to face the TFT array substrate. . Next, after cooling to room temperature, a TN liquid crystal (manufactured by Merck) was sealed, and the sealing opening was sealed with a sealing material. Further, a polarizing film was stuck on both substrate surfaces to prepare a liquid crystal display cell (1). Similarly, using sealing materials (A), (C), (D), (E) and (S) and dispersions (B), (F), (G) and (H), Liquid crystal display cells (2), (3), (4), (5) and (6) as examples were prepared in the combinations shown.

Electrode damage and presence / absence of disconnection of wiring For the liquid crystal display cells (1), (2), (3), (4), (5) and (6) obtained in this way, damage to electrodes and wiring Was checked by the following method.

  Each of the above-mentioned liquid crystal display cells is arranged on the backlight, and the TFT is driven to change the color tone of the liquid crystal display cell to a halftone display (gray display), and 2400 wirings (VGA, 480 scanning lines, 640 × 3 signal lines) (RGB)), and the number of wirings (damage) where the measured voltage dropped (damage) and the number of wirings (breakage) where the measurement voltage became zero were counted, and further damaged or disconnected parts were confirmed. Table 3 shows the results.

  As a result, there is almost no defect in a liquid crystal display device (liquid crystal display cell) using the fine particle product containing only 200 ppb or less of the coarse particles as a spacer for a sealing portion or an in-plane spacer of the liquid crystal display cell. It turned out to be extremely reliable. In addition, it is considered that the slight damage was observed in part because the liquid crystal display cell was prepared on a laboratory scale.

[Comparative Example 3]
Preparation of Liquid Crystal Display Cell By the method shown in Example 4, three TFT array substrates and three opposing substrates constituting the liquid crystal display cell were prepared.

  Next, using the microparticle groups (R2), (R3), and (R4) in which the content number of the coarse particles was determined to be the value shown in Table 2 in Example 2, a sealing material was obtained by the method shown in Example 4. (R2), (R3) and (R4) were prepared. Further, using the fine particle groups (R5), (R6), and (R7) in which the content number of the coarse particles was determined to be the value shown in Table 2 in Example 2, the dispersion liquid was obtained by the method shown in Example 4. (R5), (R6) and (R7) were prepared.

  Further, in the same manner as in Example 4, using the sealing materials (R2), (R3) and (R4) and the dispersions (R5), (R6) and (R7), in combination as shown in Table 3, Liquid crystal display cells (1), (2) and (3) as comparative examples were prepared.

In the fourth embodiment, whether or not the electrodes are damaged or the wires are disconnected is determined in the liquid crystal display cells (1), (2) and (3) obtained as described above. The examination was performed by the method shown below. Table 3 shows the results.

  As a result, a relatively large number of defects are generated in a liquid crystal display device (liquid crystal display cell) using the fine particle product containing the coarse particles in excess of 200 ppb as a spacer for a sealing portion or an in-plane spacer of the liquid crystal display cell. Was found to be of poor practicality.

FIG. 1 shows a schematic diagram relating to a method for quantifying trace coarse particles according to the present invention. Note that the slit plate 5 exemplified here relates to the method (2) for quantifying trace coarse particles. 1 is a plan view of a slit plate 5 used in a method (1) for quantifying minute coarse particles according to the present invention. FIG. 3 is a plan view of a slit plate 5 used in the method (2) for quantifying minute coarse particles according to the present invention. FIG. 4 shows an example of an exploded view of the slit plate 5 shown in FIG. 3 and shows a plan view in a state where a light shielding portion 5 d is removed. FIG. 4 shows an example of an exploded view of the slit plate 5 shown in FIG. 3 and shows a plan view in a state where a light shielding portion 5 d is removed. FIG. 4 shows an example of an exploded view of the slit plate 5 shown in FIG. 3, and shows an example of a plan view of a light shielding portion 5d. FIG. 4 shows an example of an exploded view of the slit plate 5 shown in FIG. 3, and shows an example of a cross-sectional view of a light shielding portion 5d. FIG. 4 shows an example of an exploded view of the slit plate 5 shown in FIG. 3, and shows an example of a cross-sectional view of a light shielding portion 5d. FIG. 1 is a plan view of a metal mask 8 used when forming a single particle layer 2 of fine particles on the surface of a transparent substrate 1 in the present invention. FIG. 10 is a cross-sectional view showing a state where the metal mask 8 shown in FIG. 9 is placed on the transparent substrate 1 and the single particle layer 2 is formed on the transparent substrate 1. An example of an apparatus used for forming the particle monolayer 2 of fine particles on the transparent substrate 1 in the present invention (a micro-ringing device, a dropper or a dispenser for dropping a fine particle dispersion is not shown). Is shown. FIG. 1 shows an example of a schematic diagram of a particle monolayer 2 of fine particles observed using a slit plate 5 used in a method (1) for quantifying minute coarse particles according to the present invention. FIG. 1 shows an example of a schematic diagram of a particle monolayer 2 of fine particles observed using a slit plate 5 used in a method (2) for quantifying minute coarse particles according to the present invention. FIG. 1 shows an example of a schematic view of a particle monolayer 2 of fine particles observed without using a slit 5 according to the present invention.

Explanation of reference numerals

1. Transparent substrate 2. 2. Particle monolayer Light irradiation device 4. Optical microscope 5. Slit plate 5a. Slit part 5b. Outer edge of slit plate 5c. Opening of slit plate 5d. Light shielding part of slit plate 5e. Fitting part or mounting part (joining part) of light shielding part
5f. Both ends of the light shielding part (joined part)
6. Light source 7. Observer (visual)
8. Metal mask 9. Opening of metal mask 10. Container 11. Drainage port 12. Jig 13. Microparticles 14. Coarse particles 15. Bright part of slit light projection Shaded part of reverse slit light projection

Claims (8)

A slit plate for irradiating reverse slit light placed on a light irradiation device of an optical microscope,
It is characterized by comprising an outer peripheral portion having a central portion opened, and a light-shielding portion fixed or suspended to the outer peripheral portion through or near the center of the opening inside the outer peripheral portion. And a slit plate.   The slit plate according to claim 1, wherein the opening at the outer peripheral edge portion is circular, and the diameter thereof is in a range of 10 to 100 mm.   The slit plate according to claim 1, wherein a width of the light shielding portion is in a range of 1 to 30 mm.   The slit plate according to claim 3, wherein a width of the light shielding portion is adjustable.   The slit plate is a slit plate placed on a light irradiation device of an optical microscope used for a method for quantifying coarse particles contained in a group of fine particles having an average particle size in a range of 0.5 to 10 μm. The slit plate according to any one of claims 1 to 4, wherein: A slit plate for irradiating slit light by mounting on a light irradiation device of an optical microscope used for a method for quantifying coarse particles contained in a group of fine particles having an average particle diameter in a range of 0.5 to 10 μm. So,
A slit plate having a rectangular slit having a width (short side) of 0.5 to 10 mm and a length (long side) of 5 to 50 mm in a central portion.   The slit plate according to claim 6, wherein the width of the slit is adjustable.   An optical microscope comprising the slit plate according to claim 1 as a component thereof.

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