JPH0699083A - Production of fine cross-linked porous ion exchange cellulose particles - Google Patents

Abstract

PURPOSE:To produce fine ion exchange cellulose particles very hardly causing shrinkage or swelling in a high concn. salt soln. and capable of exhibiting excellent ion exchange ability. CONSTITUTION:Fine solidified viscose particles contg. cellulose xanthate and a pore forming agent are formed, the pore forming agent is removed by washing and fine cellulose particles are regenerated by neutralization with an acid. The resulting particles are brought into a cross-linking reaction and ion exchange groups are introduced to produce the objective fine ion exchange cellulose particles. The cross-linking reaction is carried out with epichlorohydrin in the presence of an alkali for >=16hr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to crosslinked porous ion-exchange cellulose fine particles, more specifically, crosslinked porous ion-exchange cellulose fine particles which are substantially composed of regenerated cellulose and have excellent durability as an ion exchanger. The present invention relates to a manufacturing method of.

[0002]

2. Description of the Related Art Granules of cellulose or various derivatives thereof have been used as a chromatography material in recent years. Cellulose or its ion exchanger has been used as a packing material for chromatography, but spherical particles having an ion exchange group introduced, particularly cellulose as a carrier, are excellent in separating proteins, and their usefulness is highly evaluated. ing.

As a method for producing such ion-exchange cellulose fine particles, the following method proposed by the applicant of the present application is known.

That is, in JP-A-1-254256, coagulated viscose fine particles containing cellulose xanthate are prepared and neutralized with an acid to regenerate the cellulose.
A method for producing cellulose fine particles and then introducing an ion-exchange group in an alkaline homogeneous solvent is clarified.

Further, as a method of obtaining a column packing material having a desired strength, it is also disclosed in JP-A 2-24.
In 1547, coagulated viscose fine particles containing cellulose xanthate are prepared, the cellulose is regenerated by neutralizing with an acid, and then crosslinked for about 3 hours to generate crosslinked cellulose particles. A method of introducing an ion exchange group in an alkaline homogeneous solvent is clarified.

Since the crosslinked ion-exchange cellulose fine particles obtained by the latter method have various pores and pore distributions and have a large pore volume, swelling with caustic soda at the time of introducing ion-exchange groups should be severe. However, there is a feature that the ion exchange volume can be increased, and therefore, a large pressure resistance is exhibited when the column is packed. Further, since the amount of micropores is large, the surface area is increased, which has the advantage of increasing the processing capacity.

Incidentally, the improvement of the pressure resistance becomes close to the saturation point by carrying out the cross-linking reaction for about 3 hours, and the cross-linking reaction can sufficiently achieve the purpose of improving the pressure resistance in about 3 hours. .

However, the ion-exchanged cellulose particles produced by the above-mentioned known method have excellent performance as an ion exchanger, and particularly those produced by the latter method also have excellent compressive strength. However, there is a problem that the shrinkage and swelling due to the salt solution are large. Therefore, when packed in a column and repeatedly used as ion exchange chromatography, there is a drawback that good separation performance is not reproduced and gradually deteriorates, and the column packing has poor durability.

[0009]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied and as a result, ion-exchange cellulose excellent in dimensional stability with little shrinkage / swelling in a salt solution by long-time crosslinking reaction with epichlorohydrin. The inventors have completed the present invention by finding that fine particles can be produced.

The object of the present invention is that when a column is packed as an ion exchanger and a high-concentration salt solution is flowed, it does not substantially shrink or swell, and the ion exchanger can be used repeatedly. Another object of the present invention is to provide a method for producing porous ion-exchange cellulose fine particles having excellent durability that can maintain the required porous structure and continue to exhibit excellent ion-exchange ability.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to form coagulated viscose fine particles containing cellulose xanthate and a water-soluble polymer compound as a pore-forming agent, which is washed with water to form a pore-forming agent. After the removal, the particles are neutralized with an acid to regenerate the cellulose fine particles, which is then subjected to a cross-linking reaction, and then an ion-exchange group is introduced to produce ion-exchange cellulose fine particles. According to the method for producing crosslinked porous ion-exchange cellulose fine particles, the method is carried out in the presence of alkali hydroxide for 16 hours or more.

In the present invention, as the water-soluble polymer compound as a pore-forming agent, for example, a nonionic or anionic polymer compound is preferably used.

Examples of the nonionic water-soluble polymer compound include polyethylene glycol, polyethylene glycol derivatives and polyvinylpyrrolidone.
These polymer compounds have, for example, a number average molecular weight of 400 or more, preferably 600 to 400,0.
It has a number average molecular weight of 00.

As the polyethylene glycol derivative,
For example, a water-soluble compound in which only a hydroxyl group at one end of polyethylene glycol is blocked with an alkyl group having 1 to 18 carbon atoms, a phenyl group substituted with an alkyl group having 1 to 18 carbon atoms, or an acyl group having 2 to 18 carbon atoms, or An A-B-A 'type block copolymer (A and A'are the same or different and each represents a polyethylene oxide block, and B represents a polypropylene oxide block) is preferably used.
More specifically, for example, polyethylene glycol monomethyl ether, polyethylene glycol monolauryl ether, polyethylene glycol monocetyl ethyl, polyethylene glycol monomethyl phenyl ether, polyethylene glycol monononyl phenyl ether, polyethylene glycol monoacetate, polyethylene glycol monolaurate, and polyoxy. Examples thereof include ethylene block-polyoxypropylene block-polyoxyethylene block.

Further, the anionic water-soluble polymer compound preferably has, for example, a sulfonic acid group, a phosphonic acid group or a carboxylic acid group as an anionic group. These anionic groups may be in the free acid form or in the salt form.

As the water-soluble polymer compound having a sulfonic acid group as an anionic group, a water-soluble polymer compound having a sulfonic acid group such as vinylsulfonic acid, styrenesulfonic acid or methylsulfonic acid group can be produced. .

The same applies to the case where the sulfonic acid group is derived from a monomer other than styrenesulfonic acid and the case where the sulfonic acid group and the carboxylic acid group are derived from the above-mentioned monomers.

The anionic water-soluble polymer compound preferably contains at least 20 mol% of polymerized units of the above monomer having an anionic group. Such preferred polymeric compounds include copolymers and homopolymers. The anionic water-soluble polymer compound preferably has a number average molecular weight of at least 5,000, more preferably 10,000 to 3,000,000.

In the present invention, the anionic water-soluble polymer compound is not limited to the vinyl type polymer as described above, but includes, for example, carboxymethyl cellulose, sulfoethyl cellulose or salts thereof such as Na salt.

The coagulated viscose fine particles containing cellulose xanthate and the pore-forming agent can be formed by the following steps.

That is, (1) an alkaline polymer mixed aqueous solution of cellulose xanthate and a pore-forming agent is prepared,
(2) The alkaline polymer aqueous solution and the anionic polymer compound aqueous solution are mixed to generate a fine particle (droplet) dispersion of the alkaline polymer mixed aqueous solution, and (3) the dispersion is heated or Alternatively, it can be formed by a step of coagulating by mixing the above dispersion with a coagulant of cellulose xanthate.

In the above step (1), cellulose xanthate and a pore-forming agent are simultaneously dissolved in water or an alkaline aqueous solution, or cellulose xanthate is previously dissolved in water or an alkaline aqueous solution to form pores in the viscose obtained. It can be carried out by dissolving the agent or by dissolving the pore-forming agent with water or an aqueous alkali solution and then dissolving the cellulose xanthate with the solution.

The cellulose xanthate used here is not particularly limited and may be obtained as an intermediate in the rayon production process or cellophane production process. For example, the cellulose concentration is 33% by weight, the alkali concentration is 16% by weight and Cellulose xanthate having a γ value of about 40 is suitable.

The alkaline polymer mixed aqueous solution prepared in the above step (1) is adjusted to have a cellulose concentration derived from cellulose xanthate of preferably 3 to 15% by weight, more preferably 5 to 12% by weight, and the alkaline concentration is adjusted. Preferably from 2 to 15% by weight, more preferably from 5 to 10
Adjusted to% by weight. Further, the water-soluble polymer compound is preferably adjusted to be 0.03 to 5 parts by weight per 1 part by weight of cellulose.

The alkaline polymer mixed aqueous solution prepared and prepared in the step (1) is then mixed with the anionic polymer compound in the step (2). The anionic polymer compound used here is a water-soluble compound, and among the above-mentioned water-soluble polymer compounds as a pore-forming agent, anionic compounds can be mentioned.

The anionic polymer compound to be mixed is preferably an aqueous solution, more preferably an aqueous solution having a concentration of the anionic polymer compound of 0.5 to 25% by weight, further preferably 2 to 22% by weight, Used.
The aqueous solution preferably has a viscosity at 20 ° C. of 3 to 50,000 centipoise, particularly 5
Those having a centipoise to 30,000 centipoise are preferable.

The alkaline polymer mixed aqueous solution and the anionic polymer compound are preferably 0.3 to 100 parts by weight, more preferably 1 part by weight of the anionic polymer compound per 1 part by weight of cellulose in the alkaline polymer mixed solution. ~ 45
Parts by weight, more preferably 4 to 20 parts by weight, are used and mixed. The mixing is advantageously carried out at a temperature lower than the boiling point of carbon disulfide contained in the aqueous alkaline polymer solution, more preferably in the range of 0 to 40 ° C.

For the mixing, any means capable of producing a fine particle dispersion of an alkaline polymer mixed aqueous solution can be used. For example, mechanical stirring using a stirring blade or baffle plate, ultrasonic stirring, or mixing means using a static mixer can be used alone or in combination.

In the step (1), an acid-decomposable inorganic salt such as calcium carbonate is added as a dispersant to the alkaline polymer mixed aqueous solution in an amount of about 0.5 to 5% by weight. The morphology of the droplet fine particles in the fine particle dispersion liquid generated in 2) is stably and satisfactorily maintained.

According to the method of the present invention, the fine particle dispersion of the alkaline polymer mixed aqueous solution produced in the above step (2) is coagulated by the heating method or the method using a coagulating agent in the following step (3). .

The solidification by heating can be carried out at a temperature above the boiling point of carbon disulfide contained in the alkaline polymer mixed aqueous solution, for example at a temperature of 50 to 90 ° C.
When coagulating with a coagulant, it is not necessary to raise the temperature to such a level, and coagulation can usually be performed at a temperature of 0 to 40 ° C.

As the coagulant used here, for example, a combination of a lower aliphatic alcohol, an alkali metal or alkaline earth metal salt of an inorganic acid and a water-soluble polymer compound as described later is preferably used. The lower aliphatic alcohol may be linear or branched, and aliphatic alcohols having 1 to 4 carbon atoms such as methanol, ethanol, iso-propanol, n-propanol and n-butanol are preferably used. To be Examples of alkali metal salts of inorganic acids include NaCl and Na ₂ S
Na salts such as O ₄ and K salts such as K ₂ SO ₄ are preferred,
As the alkaline earth metal salt, Mg salt such as MgSO ₄ and Ca salt such as CaCl ₂ are preferable.

As the water-soluble polymer compound used for the coagulant, for example, nonionic and anionic polymer compounds are preferable, and the same anionic polymer compound used in the step (2) is used. Is preferred.

The above coagulant is used in a proportion of, for example, about 20 to 300% by weight with respect to the cellulose component in viscose.

By the above steps (1) to (3), coagulated viscose fine particles substantially composed of spherical or oblong particles having an average particle diameter of 500 μm or less can be obtained.

The coagulated viscose particles obtained are separated by filtration and washed thoroughly with water to remove the water-soluble polymer compound and anionic polymer compound as a pore-forming agent. Then, it is neutralized with an acid to convert viscose into cellulose, and fine particles containing cellulose (hereinafter referred to as "regenerated cellulose fine particles") are produced. As the acid used here, inorganic acids such as sulfuric acid and hydrochloric acid are preferable.

The regenerated cellulose fine particles obtained as described above are subsequently subjected to a crosslinking reaction. In the present invention, epichlorohydrin is used as a crosslinking agent. As the cross-linking agent, dichlorohydrin and the like are generally considered, but with cross-linking agents other than epichlorohydrin, it is possible to obtain cross-linked porous ion-exchange cellulose fine particles having stable separation ability and small shrinkage / swelling in a salt solution. Is not easy.

The cross-linking reaction is performed on the regenerated cellulose fine particles in a liquid solvent containing an alkali hydroxide. The concentration of alkali hydroxide is 3 to 7% by weight, preferably 4 to 6% by weight. By changing the concentration of the alkali hydroxide, it is possible to adjust the pore diameter of the resulting crosslinked cellulose fine particles and the crosslinked cellulose fine particles introduced with the ion exchange group.

That is, the lower the concentration of alkali hydroxide is, the larger the pore size of the cellulose fine particles after cross-linking is, but the decrease of the pore size due to the introduction of the ion-exchange group is also large.
Conversely, the higher the concentration of alkali hydroxide, the smaller the pore size of the cellulose fine particles after crosslinking, but the smaller the decrease in pore size due to the introduction of ion-exchange groups tends to be. The present inventors
As a result of diligent research, it was found that the pore diameter of the crosslinked porous ion-exchange cellulose fine particles after the introduction of ion-exchange groups was maximized by setting the alkali hydroxide concentration during the cross-linking reaction to 4 to 6% by weight. is there.

Epichlorohydrin as a cross-linking agent is adjusted to a concentration of 3 to 25% by weight in the liquid medium containing the alkali hydroxide. By changing the compounding amount of epichlorohydrin, the crosslinking density and strength of the cellulose particles after crosslinking can be adjusted.

The liquid medium used in the crosslinking reaction is, for example, 10 to 30 parts by weight with respect to 1 part by weight of cellulose, and the temperature is usually 40 to 60 ° C.

In the present invention, the crosslinking reaction must be carried out for 16 hours or longer, preferably 16 to 48 hours. 1
If the time is less than 6 hours, the obtained crosslinked porous ion-exchange cellulose fine particles will shrink and swell in the salt solution, so that the object of the present invention cannot be achieved.

Crosslinking between cellulose molecular chains is presumed to exist as a part of graft branches in a form in which hydroxyl groups of a cellulose molecule are substituted with hydroxyl groups, or in a form of being substituted with hydroxyl groups and interrupted by oxygen atoms.

Next, an ion exchange group is introduced into the obtained crosslinked cellulose fine particles. As an ion exchange group,
For example, as the cationic ion-exchange group, a general formula

[Chemical 1] The group represented by can be mentioned. Where R ₁ , R
₂ , R ₃ are independently of each other a hydrogen atom, a lower alkyl group having 1 or 2 carbon atoms (methyl or ethyl), or 1 to 2 carbon atoms.
3 is a hydroxyalkyl group (hydroxymethyl, α- or β-hydroxyethyl, hydroxypropyl, etc.). n is 1, 2 or 3.

As such a cationic ion exchange group,
Examples thereof include quaternary ammonium groups derived from amino groups such as aminoethyl group, diethylaminoethyl group, diethyl (2-hydroxypropyl) aminoethyl group and trimethylaminomethyl group.

As the anionic ion exchange group,
For example, the general formula

[Chemical 2] The group represented by can be mentioned. Here, Z is a carboxyl group (-COOH), a sulfo group (-SO ₃ H)
Or a phosphoryl group (—PO ₃ H ₂ ) and m is 0 to 3
Is an integer.

Examples of the anionic exchange group include a carboxyl group, a sulfo group, a phosphoryl group, a carboxymethyl group, a carboxyethyl group, a sulfoethyl group and a phosphoryltrimethylene group.

The crosslinked porous ion-exchange cellulose fine particles obtained by the method of the present invention are based on a type II cellulose crystal phase and a cellulose amorphous phase, and X
The crystallinity determined by the line diffraction method is preferably 5 to 50.
%, More preferably 10 to 45%, still more preferably 20.
-40%.

The exclusion limit molecular weight is, in terms of polyethylene glycol, preferably more than 4000, more preferably more than 10,000 and less than 200,000.

Further, the following formula F = (V _E -V _D ) / V _D, where V _D is blue dextran (molecular weight 200
Is the elution volume (ml) of ethylene glycol, and V _E is the elution volume (ml) of ethylene glycol.
Is usually 3 or less, preferably at least 0.6, and more preferably at least 1.0.

[0051]

INDUSTRIAL APPLICABILITY The crosslinked porous ion-exchange cellulose fine particles obtained by the method of the present invention are excellent in pressure resistance and extremely small in shrinkage and swelling due to a salt solution. Therefore, when this product is packed in a column and used as ion exchange chromatography, it exhibits excellent separation performance and, at the same time, has excellent durability performance and maintains reproducible decomposition performance even when repeatedly used.

[0052]

EXAMPLES The present invention will be described in detail below with reference to examples. In addition, before that, the measuring method of various characteristic values in this specification is described.

<Particle size measuring method> About 0.1 g of a sample was sampled,
Pour into 25 ml of pure water, stir and disperse, and measure with a light transmission type particle size distribution analyzer. The average particle size was calculated on a volume basis.

<Measurement Method of Pore Diameter and Pore Volume> Mercury Press-In Porosimeter Porosizer 931 manufactured by Micromeritic Co.
At 0, the pore size distribution was measured. The relationship between the applied pressure and the amount of injected mercury was measured by a conventional method, and data processing was performed based on the following formula.

P · D = −4K · δ · cos θ V = (Q / H) / S where P: applied pressure D: diameter of pores into which mercury can penetrate at pressure P δ: surface of mercury Tension (484 dynes / cm) θ: Contact angle of mercury with respect to sample (130 degrees) K: Cell constant (10.79) V: Pore volume H: Density of mercury (13.5389 g / cc) Q: Intrusion amount of mercury (cc) ) S: Sample amount (g) The sample used for this measurement was a sample dried by the following critical point drying method.

(Critical Point Drying Method) In order to accurately know the porosity of the ion-exchanged cellulose fine particles as swollen with water, the swelled state is maintained and the structure of cellulose is fixed by the critical point drying method according to the following procedure. did.

1. Dehydration: Water in the ion-exchange cellulose fine particles is replaced with ethanol. The ethanol / water ratio was gradually increased from 50/50 to ethanol-rich, and finally, the ethanol concentration was replaced with dehydrated ethanol to near 100%. 2. Solvent exchange: The above ethanol in the ion-exchange cellulose fine particles is replaced with isoamyl acetate. The ratio of isoamyl acetate / ethanol was gradually increased from 50/50 to replace the isoamyl acetate concentration to near 100%. 3. Drying: Cellulose particles dehydrated and fixed in isoamyl acetate were dried at a carbon dioxide gas critical point using a Hitachi critical point dryer HCP-2 type.

<Molecular Weight Fractionation Characteristics> Ion-exchange cellulose fine particles were packed in a resin column of 10 mmφ × 15 cm with water as a packing liquid at a flow rate of 4.0 ml / min for 60 minutes. Next, using each packed column as a separation column, using standard polyethylene glycol of known molecular weight under the following analysis conditions, the relationship between elution time and molecular weight was blotted, and the exclusion limit molecular weight was determined as the molecular weight of polyethylene glycol at the bending point of the curve. I asked.

The fraction index (F) is calculated by the following formula. F = (V _E −V _D ) / V _D Here, V _D : Elution volume of blue dextran (molecular weight 2,000,000) (ml) V _E : Elution volume of ethylene glycol (ml)

Analysis conditions 1. Pump Waters 6000A type 2. Eluent Pure water 3. Flow rate 1.0 ml / min 4. Temperature Room temperature 5. Detector RI detector

<Crystal Form and Crystallinity> X-ray diffraction measurement is carried out using ion-exchanged cellulose fine particles which have been replaced with methanol and air-dried. Type II cellulose has a diffraction angle 2θ of 20 °
It can be identified by having two peaks in the vicinity and around 21.8 °. The crystallinity is defined by the following formula from the X-ray diffraction pattern.

Crystallinity (%) = (c−a) / K (c−b) × 100 However, K = 0.896 (incoherent scattering correction coefficient of cellulose) a, b and c are diffraction angles 2θ. The area enclosed by the diffraction curve and the base straight line between 5 ° and 45 ° corresponds to the next measurement. a: Amorphous starch b: Air scattering c: Sample

<Measurement of Ion Exchange Capacity> Ion exchange cellulose fine particles purified and dried by the procedure shown in the following 1 and 2 are precisely weighed, and the procedure 3. The ion exchange capacity was determined according to.

1. Washing and Purification (1) Cation Exchanger Cation-exchanged cellulose fine particles were collected in a glass filter, and about 25 times the volume of wet cellulose fine particles was poured and washed with water. Next, it was immersed in 0.5N NaCl and suction dehydrated. Repeat this operation twice, again about 2
It was washed with 5 times the amount of pure water. Finally, it was immersed in 0.5N HCl, suction filtered, and thoroughly washed with a large amount of pure water.

(2) In the case of anion exchanger Anion-exchanged cellulose fine particles were taken in a glass filter, and about 25 times the volume of wet cellulose fine particles was poured and washed with water. Next, it was immersed in 0.5N NaCl and suction dehydrated. Repeat this operation twice, again about 2
It was washed with 5 times the amount of pure water. Finally, after soaking in 0.5N NaOH and suction filtration, it was thoroughly washed with a large amount of pure water.

2. The ion-exchange cellulose fine particles washed with dry water were suction-dehydrated and then dried with a ventilation dryer at 50 ° C. until the weight was reached.

3. Measurement of ion exchange capacity About 1 g of dried ion exchange cellulose fine particles is precisely weighed and 0.1N NaOH is used in the case of a cation exchanger and 0.1N HCl is used in the case of an anion exchanger, using an automatic titrator. The ion exchange capacity per 1 g of the cellulose fine particles was titrated and calculated to obtain.

<BSA (Bovine Serum Albumin) Adsorption Capacity>
After washing about 10 ml of ion exchange cellulose fine particle gel with pure water, 0.05 M Tris-HCl buffer (pH
8.3) Wash twice with 30 ml, measure 3 ml with a chromatographic tube, put in a 50 ml volumetric flask, then add 20 ml of a solution having a BSA concentration of 20 mg / ml, and further add the above Tris-HC.
After adjusting the volume to 50 ml with 1 buffer, the mixture was shaken for 10 minutes to adsorb BSA on the ion-exchange cellulose fine particles.

Then, the above-mentioned mixed solution is filtered with a filter paper,
After diluting as needed, the UV (280 nm) absorbance E of the filtrate was measured. The solute volume of the ion-exchange cellulose fine particles was assumed to be 0.5 ml, and the BSA adsorption capacity A ₁ was determined by the following calculation formula.

A ₁ (mg / ml) = {W− (E / M ₁ ) × V × N} / 3 where W is the amount of BSA placed in the flask and 400 (m
g) and V are the volumes of liquid in the flask and are 49.5 (ml). Further, M ₁ is the extinction coefficient of BSA in UV (280 nm), E is the absorbance of the filtrate, and N is the dilution ratio.

<Salt Shrinkage Ratio> A column tube having an inner diameter of 16 mm was filled with ion exchange cellulose fine particles at a flow rate of 2 ml / min with pure water to a length of about 30 cm, and the gel filling length L ₁ at this time was filled.
Was measured accurately. Next, the filling solution is filled with 0.5 M NaCl.
After exchanging with an aqueous solution and passing three times the column volume, the packing length L ₂ of the gel was accurately measured.

From L ₁ and L ₂ , the contraction rate by the salt solution (salt contraction rate) was determined by the following formula. Salt shrinkage (%) = (L ₁ −L ₂ ) / L ₁ × 100

<Protein Separation Performance> The trypsin inhibitor and ovalbumin were separated and examined by column chromatography.

A column tube having an inner diameter of 1.6 cmφ and a length of 15 cm was filled with ion-exchanged cellulose fine particles, and 25 mg / ml of trypsin inhibitor and ovalbumin were used as eluents (A) below at any concentration under the following measurement conditions. 100 μl of the dissolved solution was injected and separated.

Measurement conditions Eluent: (A) 0.02M Tris-HCl buffer (pH 8.6) (B) 0.02M Tris-HCl buffer (pH)
8.6) + 0.5M NaCl (A) → (B) 60 minutes gradient Flow rate: 2.0 ml / min Detector: UV (280 nm)

Example 1 500 g of softwood pulp was immersed in 20 l of a 18% by weight caustic soda solution at 20 ° C. for 1 hour and pressed 2.8 times. The mixture was crushed for 1 hour while being heated from 25 ° C to 50 ° C, aged, and then, 33% by weight of carbon disulfide (165 g) was added to cellulose and sulfided at 25 ° C for 1 hour to obtain cellulose xanthate. The xanthate was dissolved in a caustic soda aqueous solution to obtain viscose. The viscose had a cellulose concentration of 9.3% by weight and a caustic soda concentration of 5.9.
It had a weight percentage and a viscosity of 6,200 centipoise.

To the obtained viscose, 1 kg of polyethylene glycol (molecular weight 3000) was added and dissolved to give an alkaline polymer aqueous solution of cellulose xanthate and polyethylene glycol.

The alkaline polymer aqueous solution 60 prepared above
0 g, 5400 g of an aqueous solution of sodium polyacrylate as an anionic water-soluble polymer (polymer concentration 12% by weight, molecular weight 50,000), and calcium carbonate 60 as a dispersant
and g were placed in the reaction vessel. At the liquid temperature of 20 ° C., the liquid was stirred with a stirrer at a rotation speed of 30 rpm for 30 minutes to generate droplets of fine particles of the alkaline polymer mixed aqueous solution.
The temperature was raised in 0 minutes, and the temperature was maintained at 80 ° C. for 30 minutes to mold coagulated viscose fine particles containing polyethylene glycol.

Next, the coagulated viscose fine particles were separated from the mother liquor by a filter, washed with water, neutralized with 5% by weight hydrochloric acid to regenerate the cellulose fine particles, and further washed with water.

Next, the generated regenerated cellulose fine particles 21.
0 g was crosslinked in 5 kg of a 5% by weight aqueous sodium hydroxide solution containing 20% by weight of epichlorohydrin at 50 ° C. for 24 hours with stirring. Subsequently, the obtained crosslinked cellulose fine particles were separated from the mother liquor by a glass filter, and then 5
The mixture was neutralized with wt% hydrochloric acid and washed with a large excess of water.

50 g of the crosslinked cellulose fine particles thus obtained and 300 g of a 7 wt% caustic soda aqueous solution were mixed with each other.
After being placed in a 1-flask and sufficiently swollen with stirring, 400 g of 50 wt% 2-chlorotriethylamine aqueous solution of hydrochloric acid was added and reacted at 50 ° C. for 16 hours to introduce an ion exchange group. The particles were then separated from the mother liquor by a 25G4 type glass filter and washed with water.

The physical properties of the thus obtained crosslinked porous ion-exchange cellulose fine particles are shown in Table 1. Further, the cross-linked porous ion-exchange cellulose fine particles were packed in a column tube to separate ovalbumin and trypsin inhibitor. The results are shown in the chromatogram shown in FIG.

Example 2 An alkaline polymer aqueous solution was prepared in the same manner as in Example 1. 1,200 g of this alkaline polymer aqueous solution, 4800 g of an aqueous solution of sodium polyacrylate (polymer concentration 12% by weight, molecular weight 50,000), and 120 g of calcium carbonate were placed in a reaction tank. After stirring at a liquid temperature of 20 ° C for 30 minutes with a stirrer at a rotation speed of 45 rpm to generate fine droplets of the alkaline polymer mixed aqueous solution, the liquid temperature was raised from 20 ° C to 80 ° C in 120 minutes while continuously stirring. Warmed and maintained at 80 ° C. for 30 minutes to form coagulated viscose microparticles containing polyethylene glycol.

Then, the coagulated viscose fine particles were separated in the same manner as in Example 1, neutralized and regenerated, and washed with water.

Next, the generated regenerated cellulose fine particles 21.
0 g was crosslinked in 5 kg of a 5% by weight caustic soda aqueous solution containing 10% by weight of epichlorohydrin at 50 ° C. for 24 hours with stirring. Subsequently, the obtained crosslinked cellulose fine particles were neutralized and washed with water in the same manner as in Example 1, and then ion-exchange groups were introduced.

The physical properties of the thus obtained crosslinked porous ion-exchange cellulose fine particles are shown in Table 1. Further, the crosslinked porous ion-exchange cellulose fine particles were packed in a column tube having an inner diameter of 16 mm and a length of 15 cm to separate ovalbumin and trypsin inhibitor. The results are shown in the chromatogram shown in FIG.

Comparative Example 1 Example 2 except that the crosslinking time with epichlorohydrin used in Example 2 was changed from 24 hours to 3 hours.
Crosslinked porous ion-exchange cellulose fine particles were obtained in the same manner as in.

The results are shown in Table 1. BSA
Sufficient DEAE groups were introduced to adsorb the salt and the F value was relatively large, but the salt shrinkage was extremely large.

[0089]

[Table 1]

[0090]

EFFECT OF THE INVENTION The ion-exchange cellulose fine particles obtained by the method of the present invention have excellent dimensional stability in a salt solution, for example, a shrinkage rate of less than 0.5% in a 0.5 M NaCl aqueous solution. Therefore, the product obtained by the method of the present invention is
Even if it is repeatedly used as an ion exchanger, the excellent ion exchange ability can be maintained for a long time.

Furthermore, the ion-exchange cellulose fine particles obtained by the method of the present invention have good chemical resistance and pressure resistance, and are suitable as a packing material for liquid chromatography for separating high molecular compounds such as proteins. .

[Brief description of drawings]

FIG. 1 is a chromatogram showing the state of separation of trypsin inhibitor and ovalbumin by a column packed with crosslinked porous ion-exchange cellulose fine particles obtained in Example 1.

FIG. 2 is a chromatogram showing a state of separation of trypsin inhibitor and ovalbumin by a column packed with crosslinked porous ion-exchange cellulose fine particles obtained in Example 2.

Claims (1)

[Claims] 1. Coagulated viscose fine particles containing cellulose xanthate and a water-soluble polymer compound as a pore-forming agent are formed, washed with water to remove the pore-forming agent, and then neutralized with an acid. A method for producing ion-exchange cellulose fine particles by regenerating cellulose fine particles, then subjecting to cross-linking reaction, and then introducing ion-exchange groups, wherein the cross-linking reaction is performed with epichlorohydrin in the presence of alkali hydroxide for 16 hours or more. A method for producing crosslinked porous ion-exchange cellulose fine particles, which is characterized by carrying out.