JPH085992B2 - Colored fine particles and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to colored fine particles in which decolorization is extremely reduced, and a method for producing the same.

(Prior arts and problems to be solved by the invention) Colored fine particles include liquid crystal spacers in liquid crystal display devices, labeling materials such as fluorescent particles used in flow cytometry in the field of biochemistry, and particle size measurement of particles by an electron microscope. It has a great use as a standard particle used in cases such as, and a diagnostic carrier used for immunological diagnostic reagents.

Colored fine particles used in liquid crystal display devices are known, for example, from Japanese Patent Laid-Open Nos. 57-189117 and 59-24829.

However, since these colored fine particles have not been subjected to any treatment after coloring, so-called decolorization, in which a coloring agent such as a dye used for coloring is desorbed during use, is extremely likely to occur. For example, the conventional colored fine particles described above are
When it comes into contact with various solvents, liquid crystals, acids, alkalis, etc., the colorant elutes to cause color irregularity in the colored fine particles, and in extreme cases, the colored fine particles are completely decolorized and the performance as colored fine particles cannot be exhibited. In addition, contamination by the eluted colorant is also a problem. However, a method for preventing such discoloration of colored fine particles has never been proposed so far.

Therefore, the inventors of the present invention have intensively studied a method for producing colored fine particles in which decolorization is extremely reduced by solving the above-mentioned problems, and the solid fine particles colored with an organic dye are treated with an isocyanate coupling agent. As a result, they have found that colored fine particles whose decolorization is extremely reduced can be easily obtained at low cost, and completed the present invention.

The present invention is intended to solve the problems that the above-mentioned conventional techniques cannot solve, and provides a colored fine particle whose decolorization is extremely reduced, and a method for producing the colored fine particle capable of efficiently producing the colored fine particle. It is intended to be provided.

(Means for Solving the Problems) The colored fine particles according to the present invention are characterized in that a coating obtained from an isocyanate coupling agent is formed on the surface of solid fine particles colored with an organic dye, Thereby, the above object is achieved. Further, the method for producing colored fine particles according to the present invention is characterized in that the solid fine particles colored with an organic dye are treated with an isocyanate coupling agent, whereby the above object is achieved.

The colored fine particles and the method for producing the same according to the present invention will be specifically described below.

First, the solid fine particles colored with an organic dye, which is the object of the present invention, will be described. The solid fine particles colored with the organic dye mentioned here are liquid crystal spacers, labeling materials, standard particles,
It has a wide range of uses such as a diagnostic carrier. The material of the solid fine particles may be organic or inorganic. The organic substance is mainly a polymer chemical, and more specifically, it is a styrene-based or acrylic-based thermoplastic polymer, or an epoxy-based or phenol-based thermosetting polymer. Inorganic substances include aluminum oxide and silicon oxide. Solid fine particles made of these materials are treated with a disperse dye, an acid dye, a basic dye, etc. to obtain colored solid fine particles. When the solid fine particles are inorganic, a coating of an organic material may be first formed on the surface of the solid fine particles, and the solid fine particles may be decomposed or carbonized at a high temperature to be colored solid fine particles. Further, the solid fine particles colored with an organic dye may be those in which the material itself has a color.

In the present invention, fine particles colored with an organic dye (hereinafter,
The operation of treating the colored solid fine particles) with an isocyanate coupling agent is as follows.

The colored solid fine particles are immersed in a treatment liquid containing an isocyanate coupling agent, the treatment liquid is separated, and then the colored solid fine particles are dried.

The treatment liquid containing the isocyanate coupling agent is sprayed or applied on the colored solid fine particles and then dried.

In the above method, conditions such as the concentration of the treatment liquid, the treatment temperature, the treatment time and the like are as follows, for example. 1 part by weight of colored solid fine particles is dispersed in 2 to 900 parts by weight, preferably 5 to 600 parts by weight of a suitable dispersion medium (described later), and 0.003 to 1 part by weight of an isocyanate coupling agent, preferably 0.005 to 0.4 part by weight. Part, and the mixture is stirred at room temperature for 20 minutes to 15 hours, preferably 50 minutes to 10 hours, the dispersion medium is separated, and the remaining colored solid fine particles are 30 to 400 ° C, preferably 50 to 3 ° C.
Heat at 50 ° C. for 20 minutes to 10 hours, preferably 50 minutes to 6 hours.

In the above method, it is also possible to apply the treatment liquid using a spray gun or the like to thin solid particles colored with an organic dye spread on a glass plate or a metal plate. After coating, heat treatment may be performed under the above heating conditions.

Specific examples of the isocyanate type coupling agent used in the present invention include methylsilyl type such as trimethylsilyl isocyanate, dimethylsilyl diisocyanate and methylsilyl triisocyanate, vinylsilyl type such as vinylsilyltriisocyanate, phenylsilyl type such as phenylsilyltriisocyanate, Examples include alkoxysilane-based compounds such as tetraisocyanate silane, and ethoxysilane triisocyanate.

Examples of the dispersion medium include aliphatic hydrocarbons such as n-pentane, n-hexane and n-heptane, aromatic hydrocarbons such as benzene, toluene and xylene, esters such as methyl acetate and ethyl acetate, dioxane and tetrahydrofuran. Organic solvents such as ethers are used.

The isocyanate-based coupling agent used in the present invention has a property of reacting with a hydroxyl group to form a film, and a small amount of a hydroxyl group of water molecules bonded to the surface of colored solid fine particles,
Alternatively, when the colored solid fine particles have other hydroxyl groups, they react with each other to form a film on the surface, which causes the colored fine particles to come into contact with moisture, organic solvent, liquid crystal, acid, alkali, etc. It is presumed that the elution is prevented.

As described above, in the present invention, by treating the colored solid fine particles with the isocyanate coupling agent, a very thin coating film obtained from the isocyanate coupling agent is formed on the surface of the colored solid fine particles to form an organic dye. Desorption can be extremely reduced. Further, the isocyanate coupling agent used in the present invention is easy to handle and inexpensive, and the amount thereof is extremely small, so that the present invention can be carried out very easily and inexpensively.

For the decolorization test of the colored fine particles, the colored fine particles treated by the method of the present invention and the colored solid fine particles not treated are allowed to come into contact with water, an organic solvent, a liquid crystal, an acid, an alkali, etc. for an appropriate time at normal temperature or after being heated. It can be easily carried out by comparatively observing the degree of coloring of those compounds.

(Examples) The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 10 g of plastic fine particles having a particle size of 10 μm (Micropearl SP-210 manufactured by Sekisui Fine Chemical Co., Ltd.) and 100 g of concentrated sulfuric acid
Was added and reacted at 55 ° C. for 6 hours for acid treatment. On the other hand, 6 g of basic dye Catillon Black SBH (manufactured by Hodogaya Chemical Co., Ltd.) was dissolved in 300 ml of water, and a dye bath was prepared by adding acetic acid to adjust the pH to 4, and the above acid-treated plastic fine particles were added thereto. In addition, black solid fine particles were obtained by dyeing at 95 ° C for 6 hours.

The obtained colored solid fine particles were dispersed in 200 g of ethyl acetate, 0.5 g of tetraisocyanate silane (S1-400 manufactured by Matsumoto Pharmaceutical Co., Ltd.) was added thereto, and the mixture was stirred at room temperature for 2 hours. Then, the reaction solution was separated to obtain 25
Heat treatment was performed at 0 ° C. for 4 hours to obtain colored fine particles.

1 g of each of the colored fine particles was taken, dispersed in 100 ml of each of the compounds shown in Table 1 (all colorless), and allowed to stand for 500 hours at room temperature or under heating to observe the degree of coloring.

Comparative Example 1 The black solid fine particles used in Example 1 were not treated with an isocyanate coupling agent, and the degree of coloring of each compound was observed in exactly the same manner as in Example 1. The results shown in Table 2 below were obtained. It was

Example 2 Polystyrene particles having a particle size of 3 μm (SP-3 manufactured by Soken Kagaku)
0) solid fine particles 1 dyed black in the same manner as in Example 1
Disperse 0 g in 500 g of n-hexane and add 1.5 g of methylsilyltriisocyanate (S1-310 manufactured by Matsumoto Pharmaceutical Co., Ltd.).
Was added and the mixture was stirred at room temperature for 3 hours. Then, the fine particles obtained by separating the reaction solution were heat-treated at 150 ° C. for 1 hour to obtain colored fine particles.

1 g of each of these colored fine particles was dispersed in 100 ml of each of the compounds shown in Table 3 below and left for 500 hours at room temperature or under heating conditions, and the degree of coloring was observed. No, the same result as in Example 1 was obtained.

Comparative Example 2 The black solid fine particles used in Example 2 were not treated with an isocyanate coupling agent, and the degree of coloring of each compound was observed in exactly the same manner as in Example 2, and the results shown in Table 2 were obtained.

Example 3 Silica particles having a particle size of 1 μm (Nippon Shokubai Kagaku Kogyo Co., Ltd.)
10 g of solid fine particles obtained by dyeing Seahoster KE-P100 manufactured by Seibu Co., Ltd. with a basic dye in blue was dispersed in 50 g of benzene, and trimethylsilyl isocyanate (S1 manufactured by Matsumoto Pharmaceutical Co., Ltd.)
-130) 5 g was added and the mixture was stirred at room temperature for 1 hour. afterwards,
The fine particles separated from the reaction solution were heat-treated at 80 ° C. for 30 minutes to obtain colored fine particles.

The colored fine particles were taken in an amount of 1 g each and dispersed in 100 ml of each of the compounds shown in Table 5 below, and allowed to stand at room temperature or under heating for 500 hours, and the degree of coloring was observed. The same results as in Example 1 were obtained.

Comparative Example 3 The blue solid fine particles used in Example 3 were not treated with an isocyanate coupling agent, and the degree of coloring of each compound was observed in exactly the same manner as in Example 3, and the results shown in Table 2 were obtained.

Example 4 Solid fine particles obtained by dyeing melamine-based particles having a particle size of 20 μm (Unibex WA manufactured by Unitika Ltd.) in red with an acid dye
10 g of tetrahydrofuran was dispersed in 100 g of tetrahydrofuran, and phenylsilyl triisocyanate (Matsumoto Pharmaceutical Co., Ltd.) was added to this.
S1-360) 3 g was added, and the mixture was stirred at room temperature for 8 hours. Then, the fine particles separated from the reaction solution were heat-treated at 50 ° C. for 7 hours to obtain colored fine particles.

The colored fine particles were taken in an amount of 1 g each and dispersed in 100 ml of each of the compounds shown in Table 7 below, and allowed to stand at room temperature or under heating for 500 hours, and the degree of coloring was observed. The same results as in Example 1 were obtained.

Comparative Example 4 The red solid fine particles used in Example 4 were not treated with an isocyanate coupling agent, and the degree of coloring of each compound was observed in exactly the same manner as in Example 4, and the results shown in Table 2 were obtained.

(Effect of the Invention) In the present invention, solid fine particles colored with an organic dye are treated with an isocyanate coupling agent to form a film on the surface of the fine particles. , Organic dyes do not elute even when they come into contact with organic solvents, liquid crystals, acids, alkalis, etc. Further, the isocyanate coupling agent used in the present invention is inexpensive, the amount used is extremely small, and the treatment process is simple. Therefore, the treatment of colored solid fine particles can be carried out inexpensively and easily.

The colored fine particles according to the present invention thus obtained are
When used as a labeling material and standard particles, it eliminates the inconvenience that the existence of particles becomes unclear due to desorption of the organic dye. When used as a diagnostic carrier, the organic dye desorbs and contaminates the measurement solution. This eliminates the inconvenience of causing a measurement error. In particular, when it is used as a liquid crystal spacer in a liquid crystal display element or the like, it has an advantage that a displayed image becomes clear, and it also eliminates the inconvenience that the detached organic dye contaminates the liquid crystal and impairs the displayed image. As described above, the present invention exerts a remarkably excellent effect when used as a liquid crystal spacer and when applied to its production.

Claims (2)

[Claims] 1. Colored fine particles, characterized in that a coating film obtained from an isocyanate coupling agent is formed on the surface of solid fine particles colored with an organic dye. 2. A method for producing colored fine particles, which comprises treating solid fine particles colored with an organic dye with an isocyanate coupling agent.