JPH0457836A - Spherical porous cellulose particle comprising chitin or deacetylated chitin and cellulose, and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain the title particle excellent in mechanical strengths, adsorption properties, reactivity, etc., by causing the particle to comprise (a deacetylated) chitin and cellulose and to have specific shapes and a specific inside structure. CONSTITUTION:The title particle comprises (a deacetylated) chitin and cellulose, forms a sphere having a diameter of 0.5 mm or higher when swelled by water, has a surface with a gentle uneveness and many cracks or small openings, yet looks like a sphere approximately, and has a partially interconnected cell structure as a whole, the inside structure being such that the inside comprises cells and walls, the size and structure of the cell changes from the center to the outside surface, the number of cells increases from the center to the surface, cells of diameters vary from large to small, exist in a randomly mixed state at the center, each cell is separated by walls or partially connected to other cells, cell sizes at the center and the surface side are each specified, and the shape of each cell is cylindrical or conical.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides sustained release carriers for fragrances and medicines, adsorption carriers for dyes and pigments, immobilization carriers for bacterial cells and enzymes, and various functional groups. The present invention relates to cellulose-based porous spherical particles suitable for functional porous particles, etc., and a method for producing the same.

In this specification, when the particle diameter, pore diameter, etc. are not a sphere or a circle, they are indicated by the diameter of the largest sphere or circle that can fit therein.

[Conventional technology]

Cellulose particles can be used as immobilized carriers for bacterial cells and enzymes, sustained release carriers for fragrances and medicines, adsorption carriers for dyes and pigments, cosmetic additives, etc., and can also be used as a variety of functional cellulose by introducing various functional groups. They have become widely used as particles in many fields. For these applications, a spherical shape with excellent fluidity and mechanical strength is advantageous, regardless of whether it is used in a packed bed or a stirred tank. Also fixed for boat fishing.
The amount of bacteria, enzymes, and drugs that can be adsorbed and the number of functional groups that can be introduced are proportional to the surface and internal surface areas of the particles. Therefore, it is advantageous to make the particles porous.

Many patent applications have been filed to date regarding cellulose spherical particles and porous spherical particles.

For example, Japanese Patent Publication No. 48-60753, Japanese Patent Publication No. 57-7
No. 162, Japanese Patent Publication No. 57-45254, Japanese Patent Publication No. 55-39565, and Japanese Patent Publication No. 63-90501 disclose cellulose porous spherical particles having a structure in which many fine pores are formed in small-diameter particles. Disclosed. However, particles with large diameters and large pores, which have excellent fluidity and workability, rapid mass transfer, and fast and efficient adsorption, immobilization, and ion exchange reactions, are used in large quantities in industrial applications. It is advantageous for applications. For this reason, cellulose particles having a large diameter and having large pores are also disclosed in JP-A-64-43530 and JP-A-60-155245. The present inventors made a large diameter and large air space by dropping a mixed solution of viscose and calcium carbonate in the form of droplets through a nozzle onto a coagulation/regeneration bath, and simultaneously coagulating/regenerating cellulose and acid decomposition by calcium carbonate. It was discovered that cellulose particles having pores can be obtained and are extremely suitable for adsorption carriers, immobilization carriers, etc. It was proposed as No. 59452.

Among these new cellulose-based particles, the cellulose particles proposed in Japanese Patent Application No. 2-59452 tend to have slightly low mechanical strength. It may break when subjected to various types of stress such as shearing, torsion, etc. In addition, for the type with a functional group added, during the reaction to add the functional group,
Alternatively, they tend to be easily damaged during use in various applications.

In order to improve the mechanical strength of particles, cross-linking treatment is usually performed using a cross-linking agent, but if this treatment is applied to particles with large diameters and large pores, the entire particle becomes hard, but it loses its flexibility. It becomes brittle and its mechanical strength hardly improves. In other words, the cellulose particles having a large diameter and large pores proposed in Japanese Patent Application No. 2-59452 have the disadvantage that their mechanical strength is somewhat weak.

In addition, chitin and deacetylated chitin have good properties that cellulose lacks, such as adsorption of dyes, natural pigments and proteins, suitability as an immobilization carrier for enzymes and bacterial cells, and resistance to biological substances and mutagenicity. It is known to have adsorption properties for substances and metals, as well as good reactivity with various chemicals. Focusing on these properties, research and development of materials combined with cellulose has been carried out. For example, research on improving the dyeability of cellulose resin by blending chitin is reported in "Kobunshi Kagaku" Vol. 30, No. 338.
, pp. 320-326 (1973).

In addition, a dye adsorbent in which deacetylated chitin was insolubilized and fixed uniformly in cellulose powder was published in Japanese Patent Application Laid-Open No. 54-152.
It is disclosed in Japanese Patent No. 685. Furthermore, an adsorbent filter for sterilization filtration in which cellulose fibers are combined with diatomaceous earth and chitosan is disclosed in JP-A-63-49212. Although the purpose is not directly mentioned above, a composite film of cellulose and chitosan is described in the proceedings of the 1989 Fiber Science Society of Japan Annual Conference PS-224 (1989).

However, porous particles combining cellulose and chitin or deacetylated chitin have not yet been developed.

[Problem to be solved by the invention]

The purpose of the present invention is to improve the mechanical strength and improve adsorption and reactivity of cellulose porous spherical particles having a large diameter and many large pores, and as a result, have excellent mechanical strength and The aim is to develop cellulose-based porous spherical particles that are rich in adsorption and reactivity.

[Means to solve the problem]

- As a result of intensive research in order to solve the above problems, the present inventors have discovered that cellulose-based porous spherical particles having the following composition and structure meet the above objects, and have arrived at the present invention.

That is, the present invention is made of (^) chitin or deacetylated chitin and cellulose, (B) exhibits a spherical shape with a diameter of 0.5 mm or more when swollen with water, and has a gently uneven surface with no cracks or small pores. There are many of them, and the whole has a spherical shape. On the surface side, there are many vacancies radiating from the inside toward the surface, (
d) On the center side, pores are randomly mixed in size and mixed,
(e) All the pores are independent or partially communicated through the partition walls, and (f) the size of the pores is approximately at the center cross section of the short diameter side of the particle, On the surface side, most of the openings are occupied by pores of 30t1m or more, and on the center side, the pores are 100μm or more. (D) Cellulose-based porous spherical particles characterized by being porous and having a partially continuous pore structure as a whole.

And, its production method is to mix cellulose viscose, chitin viscose, and calcium carbonate, pressurize the mixture, extrude it from a nozzle, drop it in the form of droplets onto a coagulation/regeneration bath, and leave it in the form of droplets. Cellulose and chitin are regenerated and calcium carbonate is decomposed with acid at the same time, followed by desulfurization, bleaching, water washing, and drying as necessary, and further treatment of the particles with a concentrated alkaline aqueous solution as necessary to deacetylate chitin. This relates to a method of converting

[Function and structure of the invention]

The particles of the present invention are composed of cellulose and chitin or deacetylated chitin. There are no particular restrictions on cellulose, but
Preferably, it is regenerated cellulose by the viscose method,
Any raw material such as a linter, a dissolving valve, or any other material that can be made into viscose can be used, but dissolving pulp is preferable from the viewpoint of viscose quality and industrial implementation.

Chitin is preferably regenerated chitin by the viscose method, and the raw material is obtained by treating the exoskeleton of crustaceans, insects, etc. with acid and alkali to remove calcium and protein, and can be converted into viscose. There are no particular restrictions as long as it is. In this specification, chitin refers to poly(N-acetyl-D-glucosamine) obtained by the above-mentioned method, and refers to cellulose having one aminoacetyl group in each repeating unit of its molecular structure. They are similar substances.

Deacetylated chitin is obtained by treating this chitin with a concentrated alkali, for example, a 20-50% aqueous sodium hydroxide solution to deacetylate the aminoacetyl groups. Therefore, particles consisting of deacetylated chitin and cellulose can be obtained by immersing particles consisting of chitin and cellulose in a concentrated alkaline aqueous solution, for example in a 20-50% sodium hydroxide aqueous solution at 40-50°C. can. Generally speaking, chitin becomes soluble in an aqueous solution of a weak acid when the degree of deacetylation is 40 to 50% or more, although it varies depending on its molecular weight. The degree of dissolution of chitin in a weak acid can be used as a measure of the degree of deacetylation. In other words, by immersing the particles in an acetic acid aqueous solution for a certain period of time, it is possible to calculate how much of the chitin has eluted from the difference in nitrogen content before and after the immersion treatment, and the proportion of this eluted chitin, that is, the nitrogen content before and after the above treatment. The rate of change in can be used as a measure of the degree of deacetylation.

In this specification, particles made of deacetylated chitin and cellulose are particles made from a mixed viscose of chitin viscose and cellulose viscose by the above method, and particles made of acetic acid aqueous solution under predetermined conditions. The reduction rate of the nitrogen content (wt%) of the particles before and after the treatment was 5.
Means more than 0% particles. Particles with a smaller amount of elution than that, that is, particles with a smaller amount of elution, are referred to as particles made of chitin and cellulose.

The appearance of the particles of the present invention is 0.5 m in diameter when swollen with water.
It exhibits a spherical shape with a diameter of m or more. However, spherical shape is a broad concept that includes not only true spherical shape but also elliptical shape and granular shape. The surface may or may not be covered with a coating, and the average thickness of the coating is 10 am or less, preferably 5 μm or less.

Even if a film is formed, this film is porous with small pores and cracks present. Whether a film is formed or not, the surface is gently uneven and has many small pores and cracks.

The internal structure basically consists of holes and partition walls, and the size and structure of the holes are different between the center side and the surface side of the sphere. On the surface side, the pores extend radially from the inside toward the surface and reach the surface, and most of the pores in this region have a diameter of 30μ in the cross section of the approximately central part of the short diameter side of the particle.
m or more and 150 um or less, preferably 60 to 100 μm
That's about it. The center part of the center refers to the range of ±10%, preferably ±5% from the center. Although the thickness of the partition wall of the pore structure on the surface side is not constant, it is usually 3 to 30 um, preferably 5 to 10 um.
1! The thickness is about m.

On the center side, pores are randomly mixed in size and exist, and most of the pores in this region have a diameter of 100 to 300 μm, preferably 100 to 200 μm, in the cross section of the central portion. The thickness of the partition wall on the center side is not constant, but it is usually 10 μm.
m or more.

The pores on both the center side and the surface side communicate with a portion of adjacent pores through small holes or cracks penetrating the partition wall, and the shape of the pores is usually cylindrical or conical.

The particles of the present invention are porous spherical particles made of chitin or deacetylated chitin and cellulose having the above structure, and have an apparent density of 0.02 to 0.20 g.
/cd, and the specific surface area is 0.2 to 20 bo/g.

The apparent density is calculated by averaging the short and long axes of the particles, assuming it as the diameter of a spherical particle, calculating the volume as a sphere, finding the weight/volume, and calculating the apparent density of one particle as the density per 50 particles. Calculate and show the average value. The specific surface area was measured by the BET method using Shimadzu Micromeritics, Asatsubu 2000. Mechanical strength is also measured by stirring the particles under certain conditions and applying shearing force.This operation causes the particles to partially break and their weight to decrease, but this reduced part and the original The weight ratio (wt%) of the particles, that is, the weight reduction rate, was used as an index of strength.

Put 2g of dried grains into a beaker 11 and add 2N-Na.
Add 500m of OH. Stir for 2 hours at a rotation speed of 50 Or, p, m, using a stirrer with a 7-mark rotary blade.

The temperature of the system is maintained at 25°C. Rinse with plenty of water,
After that, it is dried with hot air and the weight is measured.

As is clear from this, particles with a large weight loss have low strength, and particles with a small weight loss have high strength. The particles of the present invention have this value of 0 to 30%.

The porous spherical particles made of chitin and cellulose are produced by mixing cellulose viscose, chitin viscose, and calcium carbonate, extruding the mixed liquid through a nozzle under pressure, and dropping it in the form of droplets onto a coagulation/regeneration bath. It can be produced by simultaneously regenerating cellulose and chitin in the form of droplets and acid decomposing calcium carbonate, followed by desulfurization, bleaching, washing with water, and drying as necessary. Further, by treating the porous spherical particles made of chitin and cellulose with a concentrated alkaline aqueous solution and proceeding with deacetylation, porous spherical particles made of deacetylated chitin and cellulose can be obtained.

In this method, first, cellulose viscose, chitin viscose, and calcium carbonate are mixed to create a cellulose/chitin mixed viscose liquid containing calcium carbonate. The solution is pressurized and forced through a nozzle and falls as droplets onto the coagulation and regeneration bath. After that, by stirring for a predetermined period of time and performing post-treatments such as desulfurization as necessary, porous spherical particles made of chitin and cellulose with internal pore structures according to each viscose condition and coagulation/regeneration conditions are formed. Can be manufactured. Further, by immersing the particles in a concentrated alkaline aqueous solution, porous spherical particles made of deacetylated chitin and cellulose can be obtained.

The cellulose viscose used is manufactured by conventional methods,
For example, it has the following composition. That is, the cellulose concentration is 3
-15% by weight, preferably 4-10% by weight. The alkali concentration is 2 to 15% by weight, preferably 5 to 13% by weight as caustic soda.

The chitin viscose used has, for example, the following composition. The chitin concentration is 2-13% by weight, preferably 3-9% by weight. The composition has an alkali concentration of 2 to 15% by weight, preferably 4 to 13% by weight.

At this time, if the cellulose or chitin concentration and alkali concentration of each viscose are outside the above-mentioned predetermined ranges, the following undesirable phenomenon usually occurs, although it depends on the blending ratio of both viscoses. That is, when the concentration of cellulose or chitin is high, the viscosity of the liquid increases, and the discharge from the nozzle becomes uneven, resulting in irregular particles.

If it is low, the mechanical strength of the particles created will be low.

Also, if the alkali concentration is high, the particle shape tends to become distorted, and if the alkali concentration is low, the surface tends to break during stirring.

The mixing ratio of cellulose viscose and chitin viscose is such that the ratio of chitin to cellulose (chitin/cellulose) is 0.
01-0.4, preferably 0.03-0.3. If this ratio is small, the mechanical strength of the particles produced will be the same as that of particles made of cellulose alone, and no improvement will occur. Furthermore, if this ratio is large, the viscosity of the mixed viscose will be too high and it will be difficult to extrude it from a nozzle, making it impossible to create uniform particles.

The ammonium chloride value of the mixed viscose obtained by mixing chitin viscose and cellulose viscose is 3 to 12, preferably 4 to 9. The viscosity of the mixed viscose is 20
50 to 15,000 centipoise, preferably 100 to 7,000 centipoise at °C. At this time, if the ammonium chloride value is outside the above-mentioned predetermined range, the following undesirable causes will occur.

If the ammonium chloride value is high, the shape of the particles produced will be distorted and inconsistent. On the other hand, if it is low, the mechanical strength of the particle surface is weak and the surface will break during stirring and become small. Even if the viscosity is low, the shape of the particles produced will be distorted, and if the viscosity is high, the particles will not be ejected uniformly from the nozzle, resulting in irregular particles or failure to eject.

Cellulose viscose can be manufactured by a method widely used industrially in the rayon industry and the cellophane industry. The raw material is not particularly limited as long as it is linter pulp, dissolving valve, or other cellulose raw material that can be made into viscose, but dissolving pulp is usually used.

Chitin viscose can be obtained by, for example, the method of Shuguchi, Togura et al.
26, 1973) as described below, but is not particularly limited to this manufacturing method.

First, cellulose was immersed in a 40% by weight aqueous sodium hydroxide solution (4 times its weight) at about 10'C for 2 hours, and then soaked for about 2 hours.
Soak at °C for 10 hours to obtain alkaline chitin. After filtering off the excess sodium hydroxide aqueous solution from the alkaline chitin using a sifter funnel, it is compressed to about three times the weight of the raw material using a press, and then pulverized using a mixer. Place the alkaline chitin in a container, evacuate the inside, and heat at approximately -20°C for 8 hours.
Leave it for a while.

Thereafter, it is thawed to about 5°C, carbon disulfide in an amount of 50% by weight of the raw chitin is injected using a vacuum, and xanthogenized at 30°C for 15 hours with occasional shaking.

Next, it is dissolved in an aqueous sodium hydroxide solution previously cooled to 0°C so that the alkali concentration is 6.0% and the chitin concentration is 5.0%, and after dissolution, it is stored frozen at about -20''C for 5 hours. It can then be produced by raising the temperature to 5°C and aging for about 15 hours.

The chitin raw material is obtained by treating the exoskeleton of crustaceans, insects, etc. with acid and alkali to remove calcium and protein, and is not particularly limited as long as it can be converted into viscose.

There are no particular restrictions on the calcium carbonate used, and either light calcium carbonate or heavy calcium carbonate may be used. Generally, from the viewpoint of workability, those having an average particle diameter of 1 to 15 μm are used. The internal pore structure of the cellulose-based porous particles of the present invention is not greatly affected by this average particle size of calcium carbonate. The amount of calcium carbonate used is 0.1 to 10 parts by weight per 1 part by weight of cellulose and chitin in the viscose. The amount of calcium carbonate does not change the basic internal pore structure of the particles, but it is involved in the generation of pores, especially fine pores of 30 μm or less, and there is a relationship that as the amount of calcium carbonate increases, the number of pores also increases. .

Mixing of cellulose and chitin mixed viscose and calcium carbonate is done by stirring with a stirrer or kneader, and calcium carbonate powder can be added directly to the viscose during stirring, or calcium carbonate powder can be dispersed in water in advance. You may also add the dispersion liquid thereto.

Any method of pressurization may be used as long as the discharge pressure from the nozzle does not fluctuate easily, but pressurization using a gear pump and pressurization using air pressure are industrially advantageous. Although there is no particular restriction, it is desirable that the diameter is 0.1 square or larger. If the aperture is smaller than 0.1 mm, the nozzle will easily become clogged, resulting in poor productivity. Furthermore, small particles such as those produced by a nozzle with a diameter smaller than 0.1 mm are not the object of the present invention.

Hydrochloric acid,
Inorganic acids such as phosphoric acid, carbonic acid, and sulfuric acid are used, but hydrochloric acid is preferred. Not only is it advantageous from the viewpoint of productivity to install multiple coagulation/regeneration baths instead of one and use them in series or in parallel, but if the conditions of each coagulation/regeneration bath are varied, It is also advantageous in that it is possible to produce particles with an internal pore structure different from those produced in individual baths. The concentration of acid in the coagulation/regeneration bath is usually 10 to 90 in the case of hydrochloric acid.
g/f, more preferably 15-70 g/ffi,
In the case of calcium chloride and sodium chloride, the concentration of salt in the bath is 0 to 400 g/l, preferably 100 to 200 g/l! It is. The coagulation/regeneration bath temperature is usually 10 to 50°C, more preferably 20 to 40°C.
It is.

According to the production method of the present invention, cellulose-based porous particles having various internal pore structures can be produced by adjusting the ammonium chloride value of viscose, the acid concentration of the coagulation and regeneration bath, the bath temperature, the salt concentration, etc. can be created. As mentioned above, in the production method of the present invention, the ammonium chloride value of viscose is usually 3 to 1.
2. The concentration of acid in the coagulation/regeneration bath is 10 to 90 in the case of hydrochloric acid.
Cellulose-based porous particles are prepared under the following conditions: the bath temperature is 10 to 50°C, and the salt concentration in the bath is 0 to 400 g/f in total when the types of salts are calcium chloride and sodium chloride. At this time, when cellulose-based particles are created under conditions where the coagulation and regeneration reactions of chitin and cellulose proceed rapidly, for example, viscose with a low ammonium chloride value (so-called advanced ripening) and a high acid concentration and a low salt concentration, In addition, when using a combination of coagulation and regeneration baths with high bath temperatures, the cellulose-based porous particles created have different structures between the center side and the surface side of the sphere, and the surface side has many small-diameter pores inside. It has a structure that extends radially from the surface to the surface, and the center side has relatively large-diameter holes randomly mixed in size. In this case, the production conditions are usually viscose ammonium chloride value 4 to 6.5, coagulation/regeneration bath acid concentration 50 to 80 g/j2 of hydrochloric acid, and salt concentration 0 to 200 g/j2 for the total of sodium chloride and calcium chloride.
It is l.

Scanning electron micrographs of cellulose porous particles having this type of internal pore structure are shown in FIGS. 1 and 2. FIG. 1 is a surface photograph, and FIG. 2 is a central cross-sectional photograph.

Conversely, when using conditions in which the coagulation and regeneration reactions of chitin and cellulose proceed slowly, that is, viscose with a high ammonium chloride value (so-called unripe), low acid concentration, high salt concentration, and low bath temperature. When a combination of coagulation and regeneration baths is used, the cellulose-based porous particles produced have a plurality of large pores of 150 μm or more, and the internal surface area of the thick partition walls is not so large.

In this case, the manufacturing conditions are usually that the ammonium chloride value of the viscose is 7 to 11, and the acid concentration of the coagulation/regeneration bath is 2 with hydrochloric acid.
0 to 40 g/l, and the salt concentration is 200 to 400 g/l in total of sodium chloride and calcium chloride.

The porous spherical particles made of chitin and cellulose are treated with a concentrated alkaline aqueous solution. For example, immersion treatment in a 40% by weight aqueous sodium hydroxide solution at 20°C for 3 hours,
After that, by washing with a large amount of water, porous spherical particles consisting of deacetylated chitin and cellulose can be obtained.

The porous particles made of chitin or deacetylated chitin and cellulose produced in this way are granular particles having a generally spherical to elliptical shape, and the size of the particles themselves is usually 0.5 to 10 mm when swollen with water. It's a struggle. The surface may or may not have a thin film formed thereon, and there are many pores inside, making it extremely porous as a whole.

Because of this structure, it can be used extremely effectively as a carrier for immobilizing bacterial cells and enzymes, as a carrier for adsorbing fragrances and drugs, as an ion exchanger, including cosmetic additives, and in a variety of other conventional applications. .

〔Example] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Chitin powder (Nacalai Tesque, reagent grade 1, purified chitin)
30g in 40% sodium hydroxide aqueous solution 120g
It is immersed at 1°C for 2 hours, then the temperature is lowered to 2°C and immersed for 10 hours to obtain alkali chitin.

Next, in a hydraulic press machine, 3.93 times the weight of the raw material (118g
) to remove excess sodium hydroxide aqueous solution.

Next, the alkali chitin is ground in a mixer and placed in a flask, the inside is evacuated and the temperature is lowered to -20°C, frozen and left for 10 hours. Next, the temperature was raised to 5°C, slowly thawed over 2 hours, and then the raw material chitin
0% carbon disulfide weighing 15.0 g was injected, and xanthogenization was carried out at 30° C. for 15 hours while shaking and mixing using a water wheel for measuring viscose reaction. Next, 394 d of water cooled to 5°C is added to dissolve the xanthide. Once dissolved, it was stored frozen at -20°C for 5 hours, then heated to 5°C, and aged at 5°C for 15 hours to obtain chitin viscose. The chitin concentration of the obtained chitin viscose was 5
．． 0%, alkaline concentration is 6.8 as sodium hydroxide
%Met.

The cellulose viscose used was the same viscose used in the production of cellophane. The cellulose viscose had a cellulose concentration of 9.2% and an alkali concentration of 6.2%.

1.000g of cellulose viscose and 122g of chitin viscose 2I! , put it in a beaker and stir it with a stirrer.
Stirring was performed for 10 minutes while maintaining the temperature at 5° C. at 0 Or, p, m, to obtain a mixed viscose. The obtained mixed viscose has an ammonia chloride value of 5.6 and a viscosity of 6 at 20°C.
．． 000 centipoise. Next, calcium carbonate (Nitto Funka Kogyo ■ "SS" 30J) was added to the mixed viscose.
) and 100 d of 60 g/f sodium hydroxide aqueous solution, and stirred with a stirrer at 700 r, p, m for 20 minutes while keeping the temperature at 5 °C to mix chitin and cellulose containing calcium carbonate. Created viscose.

The above-mentioned chitin and cellulose mixed viscose is sucked from a beaker using a tube pump (Tokyo Rika Kikai rMP-3J), pressurized, and extruded at a speed of 5 cc/min from a discharge port equipped with five syringe needles with a diameter of 1.2 mm. , a coagulation/regeneration bath 5! It was dropped onto the beaker. The hydrochloric acid concentration in the coagulation/regeneration bath is 70g/I! , temperature is 30°C1 salt concentration is 30g/salt concentration in total of sodium chloride and calcium chloride
It was l. It took about 2 hours and 30 minutes to complete the dropwise addition, after which cellulose regeneration and calcium carbonate acid decomposition were performed for 2 hours. It was then washed with a large excess of water to give 2 g/I! Desulfurization was carried out at 70'C for 1 hour in a desulfurization tower containing 2 g/l of sodium hydroxide and 2 g/l of sodium sulfide. After that, it is washed with a large excess of water, then bleached for 20'Cl2O minutes in a bleach bath containing 2.6 g/l of sodium hypochlorite, and then washed again with a large excess of water, which consists of chitin and cellulose. Porous spherical particles were obtained.

The shape of the obtained particles was spherical particles with an average particle diameter of 3.8 mm in a water-swollen state. 2 g of the particles were added to a 10% acetic acid aqueous solution 2
The mixture was poured into a solution of 0.00 and stirred at 45°C for 3 hours, and then washed with water. The nitrogen content (wt%) of the particles before and after the acetic acid cleaning treatment was measured using a CHN coder (-Sample Manufacturing rMT-).
5J). The nitrogen content of the particles before and after washing with acetic acid remained unchanged at 0.22% by weight, confirming that the obtained particles were composed of chitin and cellulose, and were not particles composed of deacetylated chitin and cellulose. .

Next, the particles were freeze-dried, and the apparent density and specific surface area were measured. The results are shown in Table 1. Furthermore, scanning electron micrographs of the particles obtained by freeze-drying are shown in FIGS. 1 and 2.

FIG. 1 is a front view, and FIG. 2 is a cross section of the central portion.

Comparative Example 1 Using the same cellulose viscose and calcium carbonate as those used in the example process, 400 g of cellulose viscose
and 40g of calcium carbonate! Pour into a beaker and mix with a stirrer at 70 Orp, p, m, while keeping the temperature at 10°C.
A cellulose viscose liquid containing calcium carbonate was prepared by stirring for 0 minutes. The subsequent operation of discharging using a tube pump was carried out in the same manner as in Example 1 to obtain porous cellulose spherical particles.

The particles were freeze-dried and their apparent density, specific surface area, and nitrogen content were measured. The results are shown in Table 1.

Table 1 *1: The short axis and long axis of the particles are averaged and regarded as the diameter of the spherical particle, and the volume as a sphere is calculated. Finding weight/volume 1
The appearance of each particle is assumed to be the density. This is calculated for 50 pieces and averaged.

*2: BET method, Shimadzu Micromeritics ASAP 2000 *3: Sample Manufacturing Co., Ltd. CHN Coder MT-5 Example 2 100 g of particles obtained in Example 1 were placed in 1 l of 25% sodium hydroxide aqueous solution, and heated at 50°C. 2 hours 10r, p.

The mixture was immersed under gentle stirring at -0 to obtain porous particles consisting of deacetylated chitin and cellulose.

The particles were subjected to acetic acid washing treatment in the same manner as in the example, and the nitrogen content before and after the treatment was measured. The results show that the particles before treatment are 0.
19%, and 0.03% after treatment, confirming that the obtained particles were composed of deacetylated chitin and cellulose.

Example 3 3 g of particles obtained in Comparative Example 1 were placed in 100 ml of a 25% aqueous sodium hydroxide solution, and immersed at 20'C for 30 minutes. Thereafter, the particles were filtered and immersed in 100 d of a mixed solution of triethanolamine and epichlorohydrin in a volume ratio of 1:3.
Allowed time to react. Next, the particles were filtered and washed with water until they became neutral to obtain quaternary ammonium chloride cellulose porous spherical particles. The above-mentioned circulation operation was also performed on the particles obtained in Example 1 to obtain quaternary ammonium chloride chitin and cellulose porous spherical particles.

Two types of particles obtained by the above method, Example 1 and Comparative Example 1
The mechanical strength of the particles obtained, that is, the weight loss rate before and after stirring under the above-mentioned predetermined conditions was measured.

At the same time, the nitrogen content (% by weight) of each particle was measured.

The results are shown in Table 2.

Table 2 Example 4 A dye decolorization experiment was conducted using the particles obtained in Example 1, Comparative Example I, and Example 2, and the dye adsorption properties of each particle were examined. The dye used was CL Ac1d Red 88, with an initial concentration of 5.
00mg/100ml dye aqueous solution 20 (3g in ld
Each particle was added and allowed to adsorb at room temperature for 10 hours with stirring.
The particles were separated by filtration, the concentration of the dye solution was measured, and the decolorization rate was calculated.

It is. The results are shown in Table 3.

Example 5 Using each of the particles obtained in Example 1, Comparative Example 1, and Example 2, a protein wastewater adsorption treatment test was conducted.

The protein wastewater used was squeezed wastewater from the tofu manufacturing process. The COD (chemical oxygen demand) of the wastewater is 9000
ppm, so a 50-fold dilution was used.

3 g of each particle was put into 200 g of diluted waste water with a COD of 126 ppm, allowed to adsorb at room temperature for 10 hours with stirring, the particles were filtered out, and the COD removal rate was determined by measuring the COD of the treated water. The results are shown in Table 3.

Table 3 Initial Wealth [Effects of the Invention] As is clear from Tables 2 and 3, the porous spherical particles made of chitin or deacetylated chitin and cellulose according to the present invention have high mechanical strength. It is a particle with good adsorption properties. Therefore, it is extremely suitable as a carrier for adsorbing or immobilizing drugs, fragrances, dyes, bacterial cells, enzymes, etc.

[Brief explanation of drawings]

Figures 1 and 2 all show the particle structure of cellulose porous particles. (That's all) Figure 1 Figure 2

Claims (2)

[Claims] (1) (A) Composed of chitin or deacetylated chitin and cellulose; (B) When swollen with water, it exhibits a spherical shape with a diameter of 0.5 mm or more, with a gently uneven surface and many cracks and small pores. It has a spherical shape as a whole, (C) (a) The interior consists of pores and partition walls, (b) The size and structure of the pores are different between the center side and the surface side, and (c) The surface side (d) In the center, the pores are randomly mixed and sized, and (e) All the pores are separated from each other through partition walls. (f) The size of the pores is such that in the cross section of the approximately central part of the short axis side of the particle, most of the pores on the surface side are pores of 30 μm or more. (G) The shape of the pores is cylindrical to conical on both the surface side and the center side, and (D) The structure as a whole has a partially continuous pore structure. Cellulose-based porous spherical particles characterized by being porous. (2) Mix cellulose viscose, chitin viscose, and calcium carbonate, pressurize the mixture, extrude it through a nozzle, drop it in the form of droplets onto a coagulation/regeneration bath, and add cellulose and chitin in the form of droplets. and acid decomposition of calcium carbonate at the same time, followed by desulfurization, bleaching, washing and drying as necessary, and further treating the particles with a concentrated alkaline aqueous solution to deacetylate as necessary. A method for producing cellulose-based porous spherical particles consisting of chitin or deacetylated chitin and cellulose.