JPS6126505A - Black particle - Google Patents

Abstract

PURPOSE:To provide black particles having narrow particle size distribution, and uniform shape and size, and usable as pigment, absorbent, filler, electrical conductive material, and especially material for medical diagnostic, by treating particles of acrylonitrile polymer at a specific temperature. CONSTITUTION:The objective black particles can be produced by oxidizing particles of an acrylonitrile polymer at 150-300 deg.C, and heating the product at >=450 deg.C. The acrylonitrile polymer may be an acrylonitrile copolymer having an acrylonitrile content of >=85mol%, preferably >=90mol%, as wel as the homopolymer of acrylonitrile. The above polymer particles may be produced by emulsion polymerization or suspension polymerization, however, particles produced by precipitation polymerization (preferably precipitation polymerization from ethyl propionate or n-butyl acetate solution) is preferable. The particle diameter is preferably 0.05-10mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to black particles that can be used as pigments, adsorbents, fillers, toners, electrical conductors, and in particular medical diagnostic materials.

[Conventional technology]

Carbon blank is a typical example of black particles.

Carbon black is produced by pyrolysis and incomplete combustion of hydrocarbons and is used in pigments, fillers, and toners.

However, carbon black is very fine (average 0.
02μ) and non-uniform in shape, it cannot be used as a medical diagnostic material as it is.

The medical diagnostic material is, for example, a carrier for an immunological agglutination reagent.

More specifically, when attempting to detect an antigen or antibody in a body fluid by an antigen-antibody reaction, a carrier on which an antigen or antibody has been immobilized in advance is mixed with a body fluid containing the antibody or antigen. The antigen and the antibody in the body fluid, or the immobilized antibody and the antigen in the body fluid, bind to each other so as to crosslink the antibodies, causing aggregation of the carrier.

The antigen or antibody can be detected qualitatively or quantitatively by testing the presence or extent of this agglutination.

In this case, the fact that the antibody is black has the advantage that it can be easily assayed by visual and microscopic observation. Furthermore, the fact that the shape and size of the carrier are constant is one of the major factors that facilitates the assay.
Carbon blanks are extremely fine and non-uniform in shape, making them unsuitable as diagnostic materials as described above.

[Problem that the invention seeks to solve]

The present invention aims to provide uniform black particles that can also be used in medical diagnostic materials.

[Means to solve the problem]

That is, in the present invention, 1 acrylonitrile polymer particle is
These black particles are obtained by oxidation treatment at a temperature of 50 to 300°C and then heat treatment at a temperature of 450°C or higher.

The acrylonitrile polymer particles of the present invention can be obtained by emulsion polymerization,
It may be prepared by any method such as suspension polymerization or precipitation polymerization, but precipitation polymerization is more preferable.

That is, acrylonitrile polymer particles prepared by emulsion polymerization are uniform, but generally tend to be fine.
In addition, there are many factors that influence the degree of polymerization and polymerization rate, such as the type and concentration of the catalyst and emulsifier, the amount of water, the type and concentration of the pH1 additive in the aqueous solution, and the stirring speed, and it is not easy to reproduce the conditions.

Precipitation polymerization is a method of polymerizing in a solvent in which the monomer is dissolved but the resulting polymer is precipitated.

Preparation of acrylonitrile polymer particles by precipitation polymerization can be carried out according to the method described in JP-A-56-156213.

In this precipitation polymerization, it is easy to control the polymerization conditions, and the black particles obtained by calcining acrylonitrile polymer particles prepared by precipitation polymerization from water or an organic solvent, preferably ethyl propionate or n-butyl acetate solution are suitable for medical use. Suitable for diagnostic materials, etc.

The acrylonitrile-based polymer of the present invention may be an acryl-lonitrile copolymer having a content of preferably 90 mol % or more.

The copolymerization components include allyl alcohol, methalyl alcohol, oxypropion acrylonitrile, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, methacrylonitrile, α-methylene geltalonitrile,
Isopropenyl acetate, acrylamide, N-methylolacrylamide, β-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, β
- To mention well-known ethylenically unsaturated compounds such as hydroxyethyl acrylonitrile, vinylpyridine, vinylpyrrolidone, methyl acrylate, methyl methacrylate, vinyl acetate, allyl chloride, sodium metaallylsulfonate, and potassium p-styrenesulfonate. I can do it.

The particles of the present invention preferably have a particle size of 0.05 to 10μ.
More preferably, it is 0.1 to 4μ, and is monodisperse.

The black particles of the present invention are obtained by firing acrylonitrile polymer particles as follows.

Firing is first performed as a pretreatment in a temperature-adjustable heating device in an atmosphere containing gaseous oxygen or gaseous sulfur, preferably in the presence of air at 150°C to 300°C, preferably at 200°C.
The oxidation treatment is carried out by heating at a temperature of ~250°C for several hours, preferably 4 to 6 hours.

Next, heat treatment is performed at a temperature of 450° C. or higher for several minutes to several hours in the absence of gaseous oxygen or gaseous sulfur, preferably under a stream of an inert gas such as nitrogen, argon, or helium.

It is desirable to change the firing temperature depending on the use of the black particles.

For example, when used as an adsorbent or an electrical conductor, it is preferable to sinter at a temperature of 1000° C. or higher.

Furthermore, the monodispersity of the black particles can be improved by treating the acrylonitrile polymer particles with silicone before firing.

The black particles of the present invention are most suitable as medical diagnostic materials. For example, it is a carrier for an immunological agglutination reagent as described above.

In this case, the agglutination reaction is measured by immobilizing the antigen or antibody on the black particles of the present invention in advance, and then mixing the particles with a measurement sample solution containing the antibody or antigen.

Physical adsorption is preferred for immobilizing antigens or antibodies on black particles.

Specific examples of antigens and antibodies include antibodies against bacteria such as Streptococcus, Staphylococcus, Diphtheria, Salmonella and Shigella, and their constituent components; antibodies against spirochetes such as Treponema pallidum and their constituents; mycoplasma and their constituents; Antibodies against constituent components; Antibodies against protozoa such as malaria parasites and their constituent constituents; Antibodies against Lykesocharia and their constituent constituents; Viruses such as influenza, adenovirus, polyoma, measles, rubella, hepatitis, mumps and their constituent constituents and antibodies against them. ; Heterologous antigens such as polyi1M, human albumin, and ovalbumin and antibodies against them; Hormones such as insulin, thyroid hormone, and chorionic gonadotropin; Enzymes such as ribonuclease, taleatin phosphokinase, and asparaginase; Kidney cell membrane, liver cell membrane, α - Organ-specific antigens and receptors such as fetoprotein and CEA; connective tissue components such as collagen and amyloid; blood cell antigens and receptors such as red blood cells and platelets; plasma proteins such as fibrin and plasminogen; rheumatoid factors and These include pathological globulins such as C-reactive protein; immune complexes; and autoantibodies against cell membranes.

Another example of medical diagnostic materials is markers. For example, cell labels.

Among blood cells, lymphocytes include B cells and T cells. B cells have receptors for the Fc portion of immunoglobulins and receptors for complement on their surfaces, while T cells do not have them.

Therefore, the marker particles are sensitized with immunoglobulin or complement and mixed with lymphocytes, whereby the marker particles bind to B cell receptors and form rosettes.

Labeling of such cells can be useful for diagnosis.

The black particles of the present invention can of course be used as diagnostic materials other than immunological agglutination methods and cell labeling.

Furthermore 1. It can be used not only for medical diagnostic materials but also for pigments, adsorbents/fillers, toners, electrical conductors, etc.

In addition, as a special use as a filler, a porous inorganic molded product can be obtained by filling the black particles into a heat-resistant inorganic material and molding the black particles, and then oxidizing the black particles and converting them into carbon dioxide gas.

〔Effect of the invention〕

Since the black particles of the present invention are uniform particles with a narrow particle size distribution and a constant shape, they can be applied to many fields including medical diagnostic materials.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1 In a test tube, 6 g of acrylonitrile, 20 mg of 2,2'-azobis-(2,4-dimethylvaleronitrile), and 20 g of ethyl propionate were thoroughly mixed, the cap was replaced with nitrogen, and the cap was kept at 45°C. It was left standing in a wet tank for 16 hours. The contents of the test tube were poured into 100 ml of acetone, and after washing with acetone by centrifugation, the acrylonitrile polymer particles were dispersed in 50 g of tetrahydrofuran.

0.5 g of "Toray Silicone" 5H-200 oil was added, stirred and mixed, and after centrifugation, the supernatant was removed and the precipitate was dried under reduced pressure.

The silicone-treated acrylonitrile polymer particles were placed in an aluminum container and heated at 200°C for 2 hours in an air atmosphere, then for 24 hours.
Oxidation treatment was performed by heating at 0° C. for 4 hours.

The oxidized acrylonitrile polymer particles were fired in an aluminum container under a nitrogen stream at temperatures of 500°C, 800"C, and 1,100°C, respectively.

Table 1 shows the results of elemental analysis of each fired acrylonitrile polymer particle.

Table 1 Those fired at 500° C. or higher were black in color, and when observed under a microscope, almost no fusion between particles was observed.

According to a scanning electron micrograph, the particle shape was approximately spherical, and the particle diameter was approximately uniform at 0.5 to 0.6 μm.

Example 2 5 of the black particles obtained by firing at 800°C in Example 1
% dispersion water 0.5tnl! Add 1 m of glass extraction antigen for syphilis serum diagnosis (Sumitomo Chemical Co., Ltd.) and ++ to 37°C Bumin 1.
A 0.01M phosphate buffered saline solution containing χ (p
H = 7.0) and was distributed to be 2.5χ.

When the above dispersion and syphilis antibody-positive serum were mixed on a glass slide, aggregation of black particles was observed.

Claims (1)

[Claims] (1) 150 to 300 acrylonitrile polymer particles
Black particles obtained by oxidation treatment at a temperature of 450°C or higher and then heat treatment at a temperature of 450°C or higher.