JPH0489835A - Abrasive-containing cellulose composite particle and its production - Google Patents

Abstract

PURPOSE:To obtain the title particles heightened in the content of abrasive particles and easily controlled in the particle diameter and the content of abrasive particles by mixing cellulose with abrasive particles and specifying the means particle diameter. CONSTITUTION:A viscose (A) having a gamma value of 30-100, a salt point of 3-20, a cellulose concentration of 3-15wt.%, an alkali concentration of 2-15wt.% and a viscosity (at 20 deg.C) of 50-2000cP is mixed with abrasive particles in an amount which is 10-200% of component A in the viscose and having a particle diameter which is 1/20 or below of that of the obtained composite particle to obtain an abrasive particle-containing viscose. The obtained viscose is mixed with an aqueous solution of an anionic polymer compound containing an anti-agglomerating agent, desirably a combination of CaCO3 with Na2CO3, to obtain a viscose particle dispersion containing the abrasive particles. This dispersion is heated to coagulate the viscose, and the coagulated viscose is neutralized with an acid and washed with water or dried to obtain the title composite particles containing cellulose and 0.02-20 pts.wt. abrasive particles and having a means particle diameter of 300mum or below.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing cellulose composite particles containing abrasive particles.

(Prior Art) Particles of cellulose or its various derivatives have recently been used in various fields as carriers for immobilizing physiologically active substances such as enzymes.

As a structure of abrasive particles and organic media, an abrasive material in which abrasive particles are fixed to the surface of an organic media made of powder of wood, bamboo, etc. using an adhesive has been disclosed (Japanese Patent Application Laid-Open No. 1983-1993). -17473). However, no mention is made of abrasive-containing cellulose composite particles in which abrasive particles are uniformly dispersed and fixed inside microparticles with cellulose as a matrix.

On the other hand, microparticles of a cellulose composite containing inorganic powder are disclosed in Japanese Unexamined Patent Application Publication No. 63-90502 and 63-90502 by the present inventors.
Although it is described in Japanese Patent No. 3-92503, the abrasive material is not mentioned. Furthermore, the methods disclosed in these documents have a problem in that it is difficult to contain a high amount of abrasive.

(Problems to be Solved by the Invention) An object of the present invention is to provide cellulose composite particles containing a high content of abrasive particles and a method for producing the same.

Another object of the present invention is to provide a manufacturing method that allows easy control of the particle size and content of abrasive particles of cellulose composite particles containing abrasive particles.

(Means and effects for solving the problems) According to the present invention, the above objects and advantages of the present invention are achieved by containing abrasive particles in an amount of 0.02 to 2 ON parts per 1 part by weight of cellulose, and having an average particle size of This is achieved by using abrasive-containing cellulose composite particles having a particle diameter of 300 μm or less, and the manufacturing method thereof includes: (2) providing viscose containing abrasive granules; Water of anionic polymer compound contained? (3) The dispersion is heated to coagulate the viscose in the dispersion, and then neutralized with acid. This can be achieved by a method for producing abrasive-containing cellulose composite particles having VF characteristics, which include soaking, washing with water, or drying.

According to the above-mentioned method of the present invention, 1! viscose containing abrasive particles is produced in the first step. and by the second step,
A viscose fine particle dispersion containing abrasive particles is produced, and in the third step, cellulose fine particles containing abrasive particles are obtained.

The abrasive particles used in the first step are cerium oxide, aluminum oxide, chromium oxide, iron oxide, zircon, alundum, silicon tinide, garnet diamond, kaolin, emery, and silicon carbide.

Boron carbide or the like is used, and its particle size is preferably 1/20 or less of the particle size of the cellulose composite particles containing the abrasive particles to be obtained.

The content ratio of abrasive particles in viscose is 10 to 2
00% by weight.

The viscose used has, for example, the following properties. Gamma value is 30-100, preferably 35-9o
It is. The salt point is 3-2o, more preferably 4-18. The cellulose concentration is 3-15% by weight, more preferably 5-13% by weight. Alkali concentration is 2-15% by weight
, more preferably 4 to 13%. The ratio of alkali (as caustic soda) to cellulose in viscose is 40 to 100% by weight, more preferably 50% by weight.
~90% by weight. The viscosity of viscose is between 50 and 20,000 centipoise at 20<0>C, more preferably between 80 and 18,000 centipoise. The viscose bulb source is preferably linter pulp, and may also be softwood or hardwood. The average degree of polymerization of viscose as cellulose is usually 10 to 1.000.

By appropriately changing the concentration of cellulose in the viscose, the ratio of abrasive particles to cellulose can be changed. For example, when the content of abrasive particles in viscose is 50% by weight, if the cell loss concentration is 10% by weight, the particles will theoretically be contained 5 times the weight of cellulose.
Furthermore, if the cellulose concentration is 5% by weight, it is theoretically possible to contain 10 times the weight of cellulose.

The viscose thus prepared is mixed with an aqueous solution of an anionic polymer compound in the second step.

The water-soluble anionic polymer compound used in the second step has, for example, a sulfonic acid group, a phosphonic acid group, or a carboxylic acid group as an anionic group. These anionic groups are preferably in the form of salts, more preferably in the form of carboxylates.

The water-soluble anionic polymer compound is preferably at least 5. It has a number average molecular weight of 10,000 to 3,000,000 more preferably than ooOl.

The water-soluble anionic polymer compound is used as an aqueous solution, more preferably as an aqueous solution in which the temperature of the cough polymer compound is 0.5 to 25% by weight, particularly preferably 2 to 22% by weight. Such an aqueous solution preferably has a viscosity of 3 centipoise to 50,000 centipoise, particularly 5 centipoise to 30,000 centipoise at 20°C.

Calcium carbonate and calcium hydroxide are used in combination as the anti-aggregation agent contained in the aqueous solution of the anionic polymer compound.

The particle size of the aggregation inhibitor used is 5 μm or less, preferably 1 μm or less. The amount of the anti-aggregation agent added is preferably 0.5 to 5% by weight in the aqueous solution of the anionic polymer compound, and more preferably 0.5 to 2% by weight from the viewpoint of the effect of preventing cohesion and deformation.

The aqueous solution of a water-soluble anionic polymer compound containing viscose containing abrasive particles and an anti-aggregation agent is 0.3 to 100 parts by weight, more preferably 1 to 45 parts by weight of a cough polymer compound per 1 part by weight of cellulose. parts by weight, particularly preferably from 4 to
20 parts by weight are used and mixed.

Advantageously, the mixing is carried out at a temperature below the boiling point of the carbon disulfide contained in the viscose, more preferably at a temperature below 0.
It is carried out in the range of ~40°C.

Mechanical stirring is preferred for mixing, particularly preferred is kneader type stirring, and low speed rotation of about 1100 rpm is preferred. Increasing the stirring rotational speed is not preferable because the generated viscose fine particles containing abrasive particles are deformed. Further, low speed rotation of 50 rpm or less is not preferable because the generated fine particles aggregate, and at low speed rotation close to 1100 rpm, the anti-aggregation effect of the anti-aggregation agent is large.

Adjustment of the particle size of the viscose fine particles affects the degree of polymerization of the water-soluble polymer compound used. When the degree of polymerization is high, the particle size becomes small, and conversely, when the degree of polymerization is low, the particle size becomes large. In this way, by selecting the degree of polymerization of the water-soluble polymer compound and the amount of anti-aggregation agent added without significantly changing the stirring rotation speed, spherical fine particles without agglomeration can be obtained, and the particles contained in viscose can be obtained. Regardless of the amount of abrasive particles, that is, even if the viscosity increases due to high content of abrasive particles, stable spherical fine particles can be obtained in a wide range of particle diameters from 5 to 500 μm.

The viscose fine particle dispersion containing abrasive particles thus obtained is heated in the third step to solidify the viscose fine particles containing abrasive particles.

Solidification by heating can be advantageously carried out at a temperature higher than the boiling point of carbon disulfide contained in the viscose, for example at a temperature of 50 to 90°C.

The coagulation reaction described above is desirably carried out while adding a mixing operation to the produced dispersion.

Neutralization with an acid is then performed using a sufficient amount of acid, e.g. hydrochloric acid,
Mineral acids such as sulfuric acid are used. In this way, cellulose particles containing abrasive particles are regenerated, and then washed with water or dried.

(Effects of the Invention) Thus, according to the present invention, as described above, by appropriately adding calcium carbonate and calcium hydroxide, which are anti-agglomeration agents, the abrasive particles can be reduced to 0.00% per part by weight of cellulose. It is possible to obtain cellulose composite particles having a high content of the particles, which can contain 02 to 20 parts by weight. Moreover, from large particles with an average particle diameter of about 300 μm,
Even particles as small as 10 to 20 μm can be spherical in shape without agglomeration and deformation.

(Example) The present invention will be explained in detail with reference to Examples below.

Example 1 Industrial viscose (viscosity 6.100 cm, cellulose concentration 8.9% by weight, alkali concentration 5.6% by weight) 9
0 g of cerium oxide and 8.0 g (100% by weight/cellulose) of cerium oxide fine particles (manufactured by Mitsui Kinzoku Mining & Co., Ltd.; abrasive fine particles, average particle size 1.7 μm) were mixed at room temperature. This mixture and 210 g of an aqueous solution of sodium polyacrylate (molecular weight 50,000, polymer concentration 12% by weight) were added with calcium carbonate as an anti-aggregation agent (
Manufactured by Shiraishi Kogyoshi; average particle size 0.2 μm) 2.1 g
(1% by weight/sodium polyacrylate aqueous solution p and hydroxide lunoum (manufactured by Ito Sangyo ■, average particle size 0.5 μm 17
．． 2g (3% by weight/sodium polyacrylate water F4 liquid) mixed at room temperature and an aqueous solution was placed in a 500m/beaker and stirred in a laboratory stirrer (MODEL L) at a liquid temperature of 30°C.
R-51B, rotating blade manufactured by Yamato Scientific Co., Ltd. 7cm) 100r
pm stirring for 10 minutes to produce a viscose fine particle dispersion containing cerium oxide fine particles, and then the liquid temperature was increased from 30°C to 70°C with continued stirring.
The temperature was raised for 5 minutes and maintained at 70°C for 30 minutes to solidify the viscose particles containing the cerium oxide particles.

Next, after separating the cellulose fine particles from the mother liquor through an IG4 type glass filter, the calcium carbonate as an anti-aggregation agent was dissolved and further neutralized with a 5% by weight aqueous hydrochloric acid solution, and then washed with a large excess of water. The mixture was washed with methanol and dried at 80° C. for 3 hours to obtain cellulose microparticles containing 98% by weight of cerium oxide microparticles/cellulose.

The obtained microparticles were spherical and had a particle diameter of 300 μm,
It was far superior to floating polishing abrasives.

Incidentally, the cerium oxide content was determined by measuring the ash content using a conventional method.

Example 2 In the same manner as in Example 1, the amount of cerium oxide fine particles was changed to 80%.
．． The cellulose particles containing cerium oxide fine particles obtained by changing the concentration to 0 g (1000 wt%/cellulose) are spherical, and the content of cerium oxide fine particles in the cellulose particles is 980 wt%/cellulose containing cellulose fine particles. Obtained.

Example 3 Industrial viscose (viscosity 6.100 centivoids, cellulose concentration 8.9% by weight, alkali concentration 5.6% by weight) 6
0 g and 5.34 g (100% by weight/cellulose) of cerium oxide fine particles (manufactured by Mitsui Kinzoku Mining & Co., Ltd.; abrasive fine particles, average particle size 1.7 μm) were mixed at room temperature. This mixture and 240 g of an aqueous solution of sodium polyacrylate (molecular weight: 500,000, polymer concentration: 9% by weight) were added with calcium carbonate as an anti-aggregation agent (
Manufactured by Shiraishi Kogyo ■, average particle size 0.2 μm) 1.4 g
(0.7% by weight/sodium polyacrylate aqueous solution) and carnoum hydroxide (manufactured by Ito Sangyo ■; average particle size 0.5μ)
m) an aqueous solution prepared by mixing 4.8 g (2jI amount %/sodium polyacrylate aqueous solution) at room temperature for 500 mj! Place it in a beaker and heat it with a laboratory stirrer (MODE) at a temperature of 30℃.
L LR-51B, rotating blade manufactured by Yamato Scientific Co., Ltd. 7cm)
Stirring was performed at 300 rpm for 10 minutes to obtain viscose fine particles containing cerium oxide fine particles.

The subsequent treatments were carried out in the same manner as in Example 1 to obtain cellulose fine particles containing 98% of cerium oxide W particles/cellulose. The obtained microparticles were spherical and had a particle diameter of 15 μm.

Comparative Example 1 Same as Example 2 except that no anti-aggregation agent was used, but
The viscos fine particles containing the cerium oxide fine particles were agglomerated and deformed, and a uniform dispersion was not obtained.

Example 4 Cellulose microparticles containing 98% by weight of cerium oxide microparticles/cellulose were obtained in the same manner as in Example 1 except that the stirring was changed to 30 rpm.

The obtained microparticles were spherical and had a particle diameter of 100 μm.

Example 5 Cellulose microparticles containing 98% by weight of aluminum oxide microparticles/cellulose were obtained in the same manner as in Example 1 except that aluminum oxide having an average particle size of 2 μm was used. The obtained microparticles were spherical and had a particle diameter of 300 μm.

Claims (1)

[Claims] 1. Abrasive particles of 0.02 to 2 parts per 1 part by weight of cellulose
Abrasive-containing cellulose composite particles containing 0 parts by weight and having an average particle size of 300 μm or less. 2. (1) Prepare viscose containing abrasive particles, (2) Mix the abrasive particle-containing viscose and an aqueous solution of an anionic polymer compound containing an anti-agglomeration agent to form abrasive particles. (3) coagulate the viscose in the dispersion by heating the dispersion, then neutralize with acid, wash with water or dry. A method for producing abrasive-containing cellulose composite particles according to claim 1. 3. The manufacturing method according to claim 2, in which calcium carbonate and calcium hydroxide are used in combination as anti-agglomeration agents.