JPH0711007A - Porous bead and its production - Google Patents

Abstract

PURPOSE:To increase the water-permeability of a porous bead composed of cellulose. CONSTITUTION:This porous bead composed of cellulose is produced by a step to form a solid material by cooling a liquid containing Glauber's salt and viscose, a step to form granules by crushing the solid material and a step to treat the obtained granules with a regeneration liquid containing an acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to beads and a method for producing the same, and more particularly to porous beads and a method for producing the same.

[0002]

2. Description of the Related Art Porous beads made of cellulose have been attracting attention as catalysts, pharmaceutical carriers, materials for immobilizing ion exchangers and adsorbents, and microcarriers for cell culture. For example, porous beads made of cellulose are widely used as a packing material for gel filtration chromatography (GPC). Further, since this porous bead can easily introduce various functional groups, it has a wide range of applications as a wide variety of ion exchangers and substrates for affinity chromatography.

As an example of such a porous bead made of cellulose, JP-A-64-43530 has a large number of air bubbles separated by a membrane and having a diameter larger than about 2 μm, and the air bubbles are adjacent to each other. Porous beads are shown forming a continuous pore structure in communication with each other by the openings in the membrane separating the air bubbles. The porous beads are produced by making a cellulosic solution into droplets, cooling the droplets to below the solidification temperature of the solution, freezing, and then extracting and removing the solvent or losing the ability to dissolve. Alternatively, the cellulose derivative solution is made into droplets, and the droplets are cooled to a temperature below the solidification temperature of the solution and frozen, and then the solvent is extracted and removed, or deactivation of the dissolution ability and regeneration of cellulose are performed simultaneously. Alternatively, it is manufactured by carrying out sequentially.

[0004]

As described above, the porous beads made of cellulose are often used by being packed in a column as various carriers. Here, when the conventional porous beads are used, it takes a long time for the mother liquor to pass through the particles. In particular, such as the separation and production of high-molecular-weight proteins of biological origin,
If the viscosity of the mother liquor is high, the transit time will be longer. Therefore, in the column using the conventional porous beads, in order to improve the reaction efficiency or treatment efficiency in the column, the liquid pressure is increased to enhance the liquid permeability. However, since increasing the liquid pressure causes the porous beads themselves to be easily deformed, there is a limit to increase the liquid permeability by the liquid pressure.

An object of the present invention is to enhance the liquid permeability of porous beads made of cellulose.

[0006]

Means for Solving the Problems The porous beads according to the first invention are made of granular cellulose and have randomly formed porosity. The porous beads according to the second invention are porous beads made of granular cellulose, which are packed in a column having an inner diameter of 10 mm to have a height of 10 cm and subjected to ion exchange by applying a pressure of 5 kgf / cm ² or less. Linear velocity is 750 to 3,200 cm when water is passed through
/ H shows water permeability.

The porous beads according to the third invention include a step of cooling a solution containing Glauber's salt and viscose to prepare a solidified body, a step of crushing the solidified body into a granular body, and an acid. It is manufactured through a process including a process for treating the granular material with a regenerating liquid. A porous bead according to a fourth aspect of the present invention is the porous bead of the third aspect, wherein neutral crystalline Glauber's salt is used as Glauber's salt.

A porous bead according to a fifth aspect of the present invention is the porous bead according to the third or fourth aspect of the present invention, wherein the solution contains Glauber's salt in an amount of 1.3 to 8 times the weight of viscose. Sixth
The porous bead according to the invention of the third aspect is the porous bead according to the third, fourth or fifth aspect of the invention, wherein the particle diameter of Glauber's salt is 1/2 to 1/10 of the target particle diameter of the porous bead.

The porous beads according to the seventh invention are the third,
In the porous beads according to the fourth, fifth or sixth invention, the solution is cooled to -15 to -50 ° C to prepare a solidified body. The porous bead according to the eighth invention is the porous bead according to the third, fourth, fifth, sixth or seventh invention, which is treated with the regenerant while rolling the granular material.

A method for producing porous beads according to a ninth aspect of the present invention comprises a step of cooling a viscose solution containing Glauber's salt to prepare a solidified body, a step of crushing the solidified body to form a granular body, and an acid A step for treating the granules with a regenerating liquid containing. A method for producing a porous bead according to a tenth invention is the method for producing a porous bead according to the ninth invention, wherein neutral crystalline Glauber's salt is used as Glauber's salt.

The method for producing porous beads according to the eleventh aspect of the present invention is the method for producing porous beads according to the ninth or tenth aspect, wherein the solution is Glauber's salt 1.3 to 8 times the weight of viscose. It uses what includes. A method for producing a porous bead according to a twelfth invention is the method for producing a porous bead according to the ninth, tenth or eleventh invention, wherein the particle diameter of Glauber's salt is 1/2 of the target particle diameter of the porous bead. ~ 1/10
Is set to.

A method for producing porous beads according to a thirteenth invention is the method for producing porous beads according to the ninth, tenth, eleventh or seventeenth invention, wherein the solution is -15 to -5.
A solidified body is prepared by cooling to 0 ° C. A method for producing a porous bead according to a fourteenth aspect of the invention is the ninth, tenth, first
In the method for producing a porous bead according to the first, twelfth or thirteenth invention, the granular material is treated with a regenerant while rolling.

*** The porous beads of the present invention are made of cellulose and have randomly formed pores. Here, the randomly formed porosity means that the size of each hole and the communicating direction of the holes are random, that is, the porosity formed on the loofah. The image of such a porosity is
It is similar to the porosity formed in a normal cellulose sponge.

The inner diameter of the porous beads of the present invention is 1
Packed in a 0 mm column to a height of 10 cm, 5 kgf
When a pressure of not more than / cm ² is applied and ion-exchanged water is passed through, the water has a linear velocity of 750 to 3,200 cm / hour. Here, the linear velocity is expressed by the following equation (1).

[0015]

[Equation 1]

The particle size of the porous beads of the present invention is from 10 to 10.
3,000 μm is preferable, and 50 to 1,000 μm is more preferable. If the particle size is less than 10 μm, the pore size described later becomes considerably small, and sufficient water permeability cannot be obtained. On the other hand, when it exceeds 3,000 μm, for example, it becomes difficult to uniformly fill the column, and as a result, channeling occurs and it becomes difficult to uniformly diffuse the liquid even inside the particles.

Further, the pore size of each hole formed in the porous bead of the present invention is 5 to 60%, preferably 20 to 40% of the particle diameter. By realizing such a pore size, the diffusibility of the liquid inside the beads is increased, and the liquid permeability of the beads is also increased. Therefore, for example, when the porous beads of the present invention are used for affinity chromatography, a high processing speed is achieved. It enables efficient separation and purification. Even when relatively large objects such as organelles (for example, organs of several μm such as mitochondria and Golgi body) and cells (usually several μm to several tens of μm) are separated, the target substance easily reaches the inside of the beads. Therefore, most of the surface area of the beads is effectively used.

If the pore size exceeds 60% of the particle size, the strength of the beads may be insufficient and the beads may be broken during use, which is not preferable. Next, a method for producing the porous beads of the present invention will be described. First, a solution containing viscose and Glauber's salt is prepared. The viscose used here preferably contains 3 to 15% by weight (preferably 5 to 10% by weight) of cellulose and 27 to 32% by weight (preferably 28 to 30% by weight) of carbon disulfide.

The degree of polymerization of cellulose used here is 20.
0 to 600, and more preferably 300 to 400 are preferable. Also,
The viscose used here is alkaline viscose. The alkali concentration of viscose is 3 to 10% by weight, preferably 6 to 8% by weight. If the alkali concentration is outside this range, it is difficult to obtain the target porous beads. The alkali concentration can be adjusted using an alkali metal salt, for example, a metal hydroxide such as caustic soda or caustic potash.

Neutral crystalline Glauber's salt is preferably used as the Glauber's salt used in preparing the above-mentioned solution. The use of neutral crystalline Glauber's salt improves the strength of the porous beads. The particle size of Glauber's salt is 1/2 to 1/1 of the particle size of the porous beads to be produced.
0, preferably 1/3 to 1/6. By using Glauber's salt having such a particle diameter, the particle diameter of the porous beads can be set within a preferable range, that is, 10 to 3,000 μm. The grain size of Glauber's salt used in the present invention is generally 1 to 1,500 μm.

When the above solution is prepared, 1.3 to 8 times, preferably 1.5 to 6 times, the amount of Glauber's salt is added to the weight of viscose. If the mixing ratio of viscose and Glauber's salt is out of this range, the strength of the porous beads may be insufficient. In addition, it becomes difficult for the porous beads to form the pores that satisfy the above-mentioned conditions. Next, the prepared solution is cooled to produce a solidified body. The cooling temperature at this time is -1
5 to -50 ° C is preferable, and -20 to -30 ° C is more preferable.

Next, the obtained solidified body is pulverized into granules. As a method for pulverizing the solidified body, for example, a method using an impact pulverizer or an attritor held at a low temperature, or a method using a pulverizer in a refrigerant that does not coagulate or regenerate cellulose can be adopted. Next, the obtained granular material is treated with a regenerating liquid containing an acid. As a result, the viscose contained in the granular material is solidified into regenerated cellulose, and porous beads made of cellulose are obtained. The acid used in the regenerating liquid may be either an inorganic acid or an organic acid. Usually, an inorganic mineral acid such as sulfuric acid, nitric acid, hydrochloric acid or phosphoric acid is used because it is easy to wash. When an inorganic mineral acid is used, ammonium sulfate, zinc sulfate, sodium sulfate and other sulfates can be added to the regenerant. By adding such a sulfate, it is possible to adjust the coagulation / regeneration speed and the strength of the bead surface. Among the sulfates, sodium sulfate is preferred. When adding sulfate,
The addition amount is 0.1 to 50% by weight with respect to the inorganic mineral acid,
Preferably 0.5 to 35% by weight, more preferably 0.5.
~ 15 wt% is set.

In the step of treating the granular material with the above-mentioned regenerating liquid, the above-mentioned granular material is put into the regenerating liquid and stirred. At this time, if the temperature of the regenerant is set to -1 to -10 ° C,
Since the surface of the charged granular material is softened, the angular portion of the surface of the granular material becomes smooth, and porous beads having a nearly spherical shape can be obtained. At this time, by rolling the granular material put into the regenerant using a granulating device or a stirring device, porous beads closer to a spherical shape can be obtained. The processing time in this case is 10
It is preferably about 40 minutes.

[0024]

EXAMPLE 1,130 g of viscose having an α-cellulose concentration of 10% by weight and an alkali concentration of 7% by weight were mixed with 2,712 g of neutral crystalline Glauber's salt having a particle diameter of 90 μm or less and thoroughly mixed. This was cooled to −22 ° C. using dry ice to prepare a solidified body, which was crushed into granules using a crusher.

The obtained granules were cooled to -22 ° C n-
The mixture was sieved in heptanol using a 600 μm standard sieve, and the slurry of the granules that passed through the sieve was put into 8,750 g of a 16 ° C. regenerant solution containing 3% dilute sulfuric acid. And
The regeneration liquid was stirred for 30 minutes while maintaining it at -5 ° C to complete the treatment of the particles with the regeneration liquid. The obtained porous beads were washed with methanol, sodium bicarbonate water and warm water in a usual manner and dried. The dried porous beads were sieved to obtain 40 g of substantially spherical porous beads having a particle diameter of 212 to 355 μm.

When the obtained porous beads were observed with an electron microscope, it was confirmed that they were beads of foam having random porosity. It was also confirmed that the beads had a strength that they were not broken even when pressed with a finger. Furthermore, the inner diameter of the obtained porous beads is 10 mm.
The column was packed to a height of 10 cm, a pressure of 0 to 5 kgf / cm ² was applied using a pump for medium pressure chromatography to pass ion-exchanged water, and the linear velocity was determined. As a comparative example, the same water permeability test was carried out using "Asahi Kasei Microcarriers", which are cellulose porous beads manufactured by Asahi Kasei Corporation. The results are shown in Table 1.

[0027]

[Table 1]

A graph of Table 1 is shown in FIG.
From the experimental results, it can be seen that the porous beads of the examples show high liquid permeability.

[0029]

EFFECTS OF THE INVENTION According to the first to eighth inventions, highly liquid-permeable porous beads made of cellulose can be realized. 9th
According to the fourteenth invention, it is possible to manufacture porous beads made of cellulose and having high water permeability.

[Brief description of drawings]

FIG. 1 is a graph of Table 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Noda 3-3-3 Nakanoshima, Kita-ku, Osaka City (Mitsui Building, Main Building) Toray Fine Chemicals Co., Ltd. Osaka Branch (72) Inventor Ryuji Uno Fukui Prefecture 129, Heisei, Matsuoka-cho, Yoshida-gun Biomaterials (72) Inventor, Kimiaki Yasuda, 129, Matsuoka-cho, Yoshida-gun, Fukui Prefecture Biomaterials, Heisei

Claims (14)

[Claims] 1. A porous bead made of granular cellulose and having randomly formed porosity. 2. Made of granular cellulose and having porosity
It is a porous bead that is packed into a column with an inner diameter of 10 mm to a height of 10 cm.
5kgf / cm ²Ion exchange by applying the following pressure
Linear velocity is 750 to 3200 cm / hr when water is passed through
Porous beads exhibiting water permeability of. 3. A step of cooling a solution containing Glauber's salt and viscose to prepare a solidified body, a step of crushing the solidified body into granules, and a treatment of the granules with a regenerating liquid containing an acid. A porous bead produced through a process including the steps of: 4. The Glauber's salt is neutral crystalline Glauber's salt
The porous beads according to. 5. The porous bead according to claim 3 or 4, wherein the solution contains 1.3 to 8 times the weight of the salt cake of Glauber's salt of the viscose. 6. The porous beads according to claim 3, 4 or 5, wherein the particle diameter of the sodium sulfate is 1/2 to 1/10 of the target particle diameter of the porous beads. 7. The porous beads according to claim 3, 4, 5 or 6, wherein the solution is cooled to −15 to −50 ° C. to produce the solidified body. 8. The porous beads according to claim 3, 4, 5, 6 or 7, which are treated with the regenerant while rolling the particles. 9. A step of cooling a viscose solution containing Glauber's salt to prepare a solidified body, a step of crushing the solidified body into granules, and a treatment of the granules with a regenerant liquid containing an acid. And a step of producing a porous bead. 10. The method for producing porous beads according to claim 9, wherein the Glauber's salt is a neutral crystalline Glauber's salt. 11. The method for producing porous beads according to claim 9, wherein the solution contains the salt of Glauber's salt in an amount of 1.3 to 8 times the weight of the viscose. 12. The particle size of the Glauber's salt is 1/2 to 1/10 of the target particle size of the porous beads, 9.
1. The method for producing the porous beads according to 1. 13. The solidified body is produced by cooling the solution to −15 to −50 ° C.
2. The method for producing porous beads according to item 2. 14. The treatment with the regenerant while rolling the granular material, according to claim 9, 10, 11, 12 or 1.
4. The method for producing porous beads according to item 3.