JPH0657754B2 - Micro cellulosic particles and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to fine cellulose particles and a method for producing the same.
More specifically, it relates to fine cellulose particles substantially consisting of regenerated cellulose and having a molecular weight exclusion limit in liquid chromatography of 3000 or less for polyethylene glycol, and a method for producing the same.

(Prior Art) Granules of cellulose or various derivatives thereof have been widely used in various fields as chromatographic materials, polymer carriers, cosmetic additives, lubricants and the like in recent years.

Conventionally, as the fine cellulose particles,
The high-purity microcrystalline cellulose developed by the company is well known.
It This high-purity microcrystalline cellulose is highly purified.
Choose pulp and add it with mineral acid under certain conditions.
Water-decomposed to wash and remove non-crystalline areas, then ground and refined.
Known to be manufactured and dried (Asahi Kasei
Published by Mar. 1, 1983, "Crystalline cellulose,
Avicel See "Pamphlett"). Same pan fr
In addition, according to Tsuto, the above high-purity microcrystalline cellulose
Is chemically natural cellulose, namely type I cellulosic
The average particle size of about 6 μm
Saisai to average particle size of about 40 μm or about 120 μm
It can be seen that even large ones are on the market. This high
Pure microcrystalline cellulose (grade PH-M06)
According to the research by the author, it has a crystallinity of about 31 to 35%.
It was revealed that the crystallinity is relatively good.
It was

JP-A-48-21738 discloses that the γ value is 50 or more,
A method is disclosed in which viscose having an average degree of polymerization of 400 or more is dropped in a granular form into a coagulation / regeneration bath having a low acid concentration and a low Glauber's salt concentration to gradually perform coagulation and regeneration. In the example of the publication, 30 to 46 mesh (300 to 590 μm) is used.
m) recycled cellulose granules are described.

Japanese Examined Patent Publication No. 56-21,761 discloses that viscose is extruded from a discharge port, and a continuous flow is naturally changed to a droplet flow in air.
A method is disclosed in which the liquid is supplied to the coagulation-regeneration bath as substantially spherical droplets. According to the same publication, the same method provides 16 to 1
It is described that 70 mesh (88-1168 μm) cellulose granules can be obtained.

Japanese Examined Patent Publication (Kokoku) No. 57-7162 discloses a hollow regenerated cellulose fine particle having a large void substantially in the center thereof. The granulate is described as having an apparent density of 0.4 g / cm ³ or less and 16-170 mesh.

Japanese Patent Laid-Open No. 48-60753 discloses the above-mentioned Japanese Patent Laid-Open No. 48-
By using a coagulation / regeneration bath having an acid concentration and a Glauber's salt concentration higher than those of the method disclosed in Japanese Patent No. 21738,
A method of making 170 mesh porous regenerated cellulose particles is disclosed.

JP-B-49-89,748 discloses that a fibrous material of regenerated cellulose is hydrolyzed, dried and crushed to have a length / diameter ratio of 20/1 to 2/1 and a length of 1 mm or less. A method of making a cellulose powder is disclosed.

JP-A-57-212,231 discloses a method for producing a cellulose powder from a fibrous material of natural cellulose in the same manner as described above.

Japanese Patent Publication No. 57-45,254 and corresponding US Patent No. 4
No. 0555510 discloses that a suspension of viscose in a water immiscible liquid such as chlorobenzene is heated to a temperature of 30 to 100 ° C. with continuous stirring to solidify and then the resulting particles are acid decomposed. According to the particle size 150-350μ
It is disclosed that particles of m (85% by volume) are obtained (Example 1).

JP-B-55-39565 discloses that a solution of cellulose triacetate in methylene chloride or chloroform is dripped with stirring into an aqueous medium in which a dispersant such as gelatin or polyvinyl alcohol is dissolved, and heated to give triacetic acid. Disclosed is a method for producing spherical cellulose particles by forming spherical particles of cellulose and then saponifying the spherical particles. The examples of the publication disclose cellulose particles of 30 to 500 μm.

Japanese Examined Patent Publication No. 55-40618 discloses a method of producing cellulose particles of 50 to 500 μm from a cellulose ester other than cellulose triacetate by the same method as above.

JP-A-55-28763 discloses a method for producing fine spherical particles by spray-drying a solution prepared by dissolving a cellulose fatty acid ester in a mixed solvent of three or more solvents having different boiling points of 30 ° C. or more. There is.

JP-A-56-24429 and corresponding US Pat. No. 4,312,980 and European Patent Publication No. 25,639 disclose chlorinated hydrocarbons having a boiling point lower than that of the following aqueous medium and higher aliphatic compounds having 6 or more carbon atoms. A solution of cellulose triacetate in a mixed solvent from alcohol is suspended in an aqueous medium to form droplets of said solution, then the chlorinated hydrocarbons in the droplets are removed by evaporation, the resulting aliphatic A method for producing porous cellulose spherical particles by saponifying spherical particles of cellulose triacetate containing a higher alcohol and removing aliphatic higher alcohol from the spherical particles is disclosed. The example discloses particles having a particle size of 100 to 200 μm.

In Japanese Patent Laid-Open No. 56-24430, a triacetate ester of crystalline cellulose having a constant degree of polymerization is dissolved in a chlorinated hydrocarbon having a boiling point lower than that of an aqueous medium A described later, and this solution is suspended in the aqueous medium A. To form droplets of the solution, then evaporate and remove chlorinated hydrocarbons in the droplets, and saponify the obtained spherical particles of cellulose triacetate to produce porous cellulose spherical particles. Have been described. The examples of the publication disclose porous cellulose spherical particles having a particle size of 100 to 200 μm. JP-A-57-388
No. 01 and corresponding European Patent Publication No. 47,064 and U.S. Pat. Nos. 4,390,691 and 446,189 disclose a cellulose organic acid ester solution dissolved in a solvent mainly containing a chlorinated hydrocarbon in an aqueous medium. Suspended to form droplets of the solution, the chlorinated hydrocarbon solvent in the droplets is evaporated to form cellulose organic acid ester spherical particles, which are then saponified to form porous spherical cellulose particles. In the method for producing, a method for producing porous spherical cellulose particles, characterized in that the cellulose organic acid ester solution is mixed with an acid or an alkali before being suspended in an aqueous medium, is described. There is.
The examples of the publication describe porous spherical cellulose particles having a particle size of 50 to 100 μm and an exclusion limit molecular weight of about 2000. However, the product manufactured by this method has the drawback of being inferior in the pressure resistance at high speed and the fractionation performance described later, and is not yet satisfactory for use on an industrial scale.

Japanese Patent Application Laid-Open No. 57-159,801 discloses that cellulose is dissolved in a DMSO solution of paraformaldehyde, the obtained solution is dispersed in a liquid, and the solution is mixed with a coagulant of the cellulose to gel decomposed droplets of the cellulose. A method for producing granular cellulose gel by aggregating and regenerating with warm water as necessary is disclosed.

JP-A-57-159802 discloses a method for producing porous cellulose by immersing granular cellulose in a DMSO solution of paraformaldehyde and swelling it by heating. JP-A-57-219,333 discloses an aqueous medium solution containing a cellulose acetate solution in an organic solvent, a dispersant, a surfactant and an antifoaming agent, and a peripheral speed of a rotary blade of 45.
A method for producing spherical fine particles of cellulose acetate by stirring and mixing at 0 m / min or more, 2000 rpm or more, and at least 10 seconds and evaporating an organic solvent is disclosed.

Japanese Unexamined Patent Publication (Kokai) No. 48-30752 discloses a method for producing a cellulose powder by treating the cellulose with tetrahydrofuran and then pulverizing it.

Japanese Unexamined Patent Publication (Kokai) No. 50-105758 discloses a method for producing fine cellulose powder by passing a dried cellulose sheet between a pair of rotating rolls under pressure and then hydrolyzing it with a mineral acid. ing.

[Problems to be solved by the invention]

An object of the present invention is to provide fine cellulose particles which substantially consist of regenerated cellulose or type II cellulose and have an exclusion limit molecular weight of 3000 or less by polyethylene glycol. Another object of the present invention is to provide fine cellulose particles useful as a packing material for liquid chromatography used in so-called desalting for separating proteins from salts such as sodium chloride, ammonium sulfate, ammonium chloride, calcium chloride and sodium sulfate. To do.

Still another object of the present invention is to provide a novel method for producing the fine cellulose particles of the present invention as described above.

Further objects and advantages of the present invention will be apparent from the following description.

[Means and Actions for Solving Problems]

According to the present invention, the above objects and advantages of the present invention consist essentially of (a) type II cellulose, and (b) the crystallinity determined by X-ray diffraction is in the range of 5 to 35%, (c) It consists essentially of spherical or oblong particles having an average particle size of 300 μm or less, and (d) the exclusion limit molecular weight of polyethylene glycol is 3,0.
It is achieved by the minute cellulose particles characterized by being 00 or less.

The exclusion limit molecular weight with polyethylene glycol in the present invention is a value obtained by preparing a polyethylene glycol-converted molecular weight calibration curve and following a conventional method. That is, using a column packed with measurement particles, for each polyethylene glycol of various known molecular weight, measuring the elution time,
The results are plotted on a graph in which the vertical axis is scaled with the molecular weight on a 10 g scale and the horizontal axis is scaled with the elution time (minutes) to prepare a molecular weight calibration curve, and the bending point of the obtained molecular weight calibration curve is plotted. Calculated as molecular weight (1st
(See Figure and Table 7).

According to the present invention, the fine cellulose particles of the present invention are as follows: (1) The following composition: Cellulose component 10 to 60 wt% (converted to cellulose) Water 90 to 35 wt%, and water-soluble polymer compound 0 to 5 wt% By contacting the coagulated viscose fine particles having a with a concentrated aqueous solution of an inorganic salt or a hydrophilic medium, a part of the water contained in the coagulated viscose fine particles is removed, and then (2) the dehydrated product obtained is obtained. The coagulated viscose fine particles are neutralized with acid to convert viscose into cellulose, and, if necessary, (3) during the removal of water in the step (1), during the neutralization in the step (2) or Thereafter, the water-soluble polymer compound is removed from the fine particles produced in each step, and further, (4) the fine particles obtained in the above step (2) or (3) are separated from the mother liquor, and desulfurized if necessary. ,acid There, washed with water or drying, it can be by connexion preparation to the preparation of fine cellulose particles characterized by.

The fine cellulose particles of the present invention are characterized in that they have the above requirements (a) to (d). Each of these requirements will be described below.

First, the fine cellulose particles of the present invention consist essentially of type II or regenerated cellulose. Therefore, the cellulose fine particles composed of natural cellulose or type I cellulose are completely different from the fine particles of the present invention. As is well known, type II cellulose and type I cellulose are distinguished by X-ray diffraction. The X-ray diffractogram of the type II cellulose shows:
Diffraction angle (2θ) 15 clearly present in type I cellulose
There is virtually no diffraction peak at °.

Secondly, the fine cellulose particles of the present invention are characterized by the crystallinity determined by the X-ray diffraction method, and are 5-30%.
It has a crystallinity of. The fine cellulose particles of the present invention are preferably 7 to 33%, more preferably 10 to 30%.
It has a crystallinity of%. The microcellulose of the present invention is not amorphous, but crystalline as specified by the crystallinity.

Thirdly, the fine cellulose particles of the present invention have an average particle size of 3
It essentially consists of spherical or oblong particles having a size of 00 μm or less. The minute cellulose particles of the present invention are thus constituted by minute particles. The fine cellulose particles of the present invention,
Further, the average particle size is 1 to 200 μm, more preferably 2
Substantially composed of spherical to ellipsoidal particles of ˜150 μm. The term “oblong” as used herein means
It is a concept that includes a projection view or a plan view of a particle having a shape such as an ellipse, an elongated circle, a peanut shape, or an oval shape. The fine cellulose particles of the present invention are spherical or ellipsoidal as described above, and are therefore different from particles which are angular or have an irregular shape.

Fourthly, the fine cellulose particles of the present invention need to have an exclusion limit molecular weight of 3,000 or less by polyethylene glycol. The exclusion limit molecular weight can be determined by packing a column with water-swollen microcellulose particles and then using a standard polyethylene glycol of known molecular weight. When the exclusion limit molecular weight exceeds 3,000, the separation performance between the compound having a molecular weight of 3,000 or less and the salt decreases. In order to efficiently separate lower molecular weight compounds, the exclusion limit molecular weight is preferably 2500 or less, more preferably 2000 or less, and particularly preferably 150.
It is 0 or less.

Secondary physical property values that characterize the fine cellulose particles of the present invention are as follows.

Cellulose constituting the fine cellulose particles of the present invention,
Usually, those having a degree of polymerization in the range of 100 to 700 are preferable. When the degree of polymerization is less than 100, the pressure resistance decreases, whereas when it exceeds 700, the fine cellulose particles tend to be deformed, and it becomes difficult to obtain uniform particles.

The fine cellulose particles of the present invention have the following formula Where V _D is the elution volume of blue dextran (molecular weight 2 million)
(ml) and V _E is the elution volume (ml) of ethylene glycol. Preferred is one having a Fractional Index (F) defined by In order to efficiently separate a high molecular compound such as a protein from a salt, it is preferable that the fraction index is as large as possible. The fraction index is more preferably at least 0.
According to the present invention, the more preferable fraction index is 1.0 or more.

Furthermore, the microcellulose particles of the present invention preferably have a fraction index of at most 2, more preferably at most 1.5.

Furthermore, it is preferable that the fine cellulose particles of the present invention have a pressure resistance when wet in a column of at least 5 kg / cm ² . In order to process a large amount of polymer compounds such as proteins and salts on an industrial scale in a short time,
Higher pressure resistance when wet is more useful and preferable. More preferably at least 10 kg / cm ^2, still more preferably 40 kg / cm ² or more, according to the present invention, or 80 kg / c
It is possible to manufacture m ² or more. When packed in the same column, if the particle size of the cellulose fine particles becomes smaller,
Column pressure rises. The cellulose fine particles of the present invention,
Since a column having a particle size of 10 μm can withstand a column pressure of 80 kg, there is a great merit that various particle sizes can be selected according to the intended separation accuracy and processing amount.

Furthermore, the fine cellulose particles of the present invention have a copper value of 3 or less, have a small amount of carboxyl groups, and have a small amount of adsorption due to ionicity.

The method for producing the fine cellulose particles of the present invention will be described below. According to the method of the present invention, as described above, a part of the water is removed from the coagulated viscose fine particles containing the water-soluble polymer compound in the first step, and the dehydrated coagulated bismuth is removed in the second step. The coarse particles are neutralized with an acid to convert viscose into cellulose, and the water-soluble polymer compound is removed from the fine particles in the third step. The coagulated viscose fine particles containing the water-soluble polymer compound used in the first step are as follows: (A) Cellulose Dentate and the other aqueous alkaline polymer solution of the first water-soluble polymer compound are prepared. Or (B) mixing the alkaline polymer aqueous solution with a second water-soluble anionic polymer compound to form a fine particle dispersion of the alkaline polymer aqueous solution, and (C) heating the dispersion. Produced by mixing the dispersion with a coagulant of cellulose dentate to coagulate the cellulose dentate in the dispersion as fine particles containing the first water-soluble polymer compound. be able to.

The coagulated viscose fine particles containing a water-soluble polymer compound used in the first step of the present invention are (A) Cellulose Dentate and the other aqueous alkaline polymer solution of the first water-soluble polymer compound. Prepare (B) the above alkaline polymer aqueous solution and a water-soluble polyethylene glycol or polyethylene glycol derivative having a number average molecular weight of 1,500 or more to form a fine particle dispersion of the alkaline polymer aqueous solution at a temperature of 55 ° C. or more. , (C) the dispersion is further heated at a temperature equal to or higher than the temperature at the time of producing the dispersion, or by mixing the dispersion with a coagulant of cellulose densate in the dispersion. Can be produced by coagulating the cellulosic dentate in the form of fine particles containing the first water-soluble polymer compound.

The first method and the second method are, as described above, the step (A) of preparing the cellulose dentate and the alkaline polymer aqueous solution of the first water-soluble polymer compound, a fine particle dispersion of the alkaline polymer aqueous solution. (B) and the step (C) of forming the cellulose-containing fine particles, which are basically the same steps.

The first method and the second method are different in that the second polymer compound used in the step (B) is anionic in the first method, but nonionic in the second method. To do. First, the first method for producing the solidified viscose fine particles used in the present invention will be described below.

According to the first method, as described above, an alkaline polymer aqueous solution of cellulose densate and the other first water-soluble polymer compound is prepared in the step A, and the fine particle dispersion of the alkaline polymer aqueous solution is prepared in the step B. A liquid is generated, and in step C, fine particles in a form containing the first water-soluble polymer compound are generated. In the step A of preparing an alkaline polymer aqueous solution of cellulose xanthate and the other first water-soluble polymer compound, the step A is to dissolve the cellulose xanthate and the other first water-soluble polymer compound simultaneously in water or an alkaline aqueous solution. Or first dissolve cellulose xanthate in water or an aqueous alkali solution and dissolve the first water-soluble polymer compound in the resulting viscose, or alternatively, dissolve the first aqueous solution polymer compound in water or an aqueous alkali solution. It can be carried out by dissolving Cellulose xanthate with the solution after the dissolution.

The above-mentioned dissolution can be carried out, for example, by mixing with a kneader or a high-viscosity stirring blade.

Cellulose xanthate may be obtained as an intermediate in the rayon production process or the cellophane production process, for example, a cellulose concentration of 33% by weight and an alkali concentration of 16% by weight.
And cellulose xanthate having a γ value of about 40 is suitable.

As the first water-soluble polymer compound, for example, a nonionic or anionic polymer compound is preferably used. As the nonionic first water-soluble polymer compound,
Examples thereof include polyethylene glycol, polyethylene glycol derivatives and polyvinylpyrrolidone. These polymer compounds have, for example, a number average molecular weight of 400 or more, and a preferable one has a number average molecular weight of 600 to 400,000.

As the polyethylene glycol derivative, for example, only a hydroxyl group at one end of polyethylene glycol has 1 to 1 carbon atoms.
A water-soluble compound blocked with an alkyl group having 8 to 8 carbon atoms, a phenyl group substituted with alkyl having 1 to 18 carbon atoms, or an acyl group having 2 to 18 carbon atoms, or an ABA 'type block copolymer (A , A ′ are the same or different and each represents a polyethylene oxide block, and B represents a polypropylene oxide block). 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 Examples thereof include polyoxyethylene block-polyoxypropylene block-polyoxyethylene block and the like.

Further, the anionic first 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 the salt form.

The first water-soluble polymer compound having a sulfonic acid group as an anionic group has a sulfonic acid group such as vinylsulfonic acid, styrenesulfonic acid, methylstyrenesulfonic acid,
It can be derived from monomers such as allyl sulfonic acid, methallyl sulfonic acid, acrylamido metal propane sulfonic acid or salts thereof.

Similarly, the first water-soluble polymer compound having a phosphonic acid group as an anionic group can be derived from a monomer such as styrenephosphonic acid, vinylphosphonic acid or salts thereof.

Further, the water-soluble polymer compound having a carboxylic acid group as an anionic group can be derived from a monomer such as acrylic acid, methacrylic acid, styrenecarboxylic acid, maleic acid, itamanic acid or salts thereof.

For example, the first water-soluble polymer compound having a carboxylic acid group can be prepared according to a method known per se, for example, by mixing sodium acrylate alone or with another copolymerizable monomer such as methyl acrylate. It is polymerized and supplied as a homopolymer or copolymer containing polymerized units of sodium acrylate. Further, for example, a styrene homopolymer can be sulfonated to produce a water-soluble polymer compound having a sulfonic acid group.

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

The water-soluble first anionic polymer compound preferably contains at least 20 mol% of polymerized units of the above-mentioned monomer having an anionic group. Such preferred polymeric compounds include copolymers and homopolymers.

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

The water-soluble first anionic polymer compound used in step A is not limited to the vinyl type polymer as described above,
Other examples include carboxymethyl cellulose, sulfoethyl cellulose or salts thereof such as Na salt.

According to the first method, as described above, first, in step A, an aqueous alkaline polymer solution is prepared. The aqueous polymer solution has a cellulose concentration derived from cellulose xanthate, preferably 3 to 15% by weight, more preferably 5 to 12% by weight.
And the alkali concentration is preferably 2 to 1
It is adjusted to 5% by weight, more preferably 5 to 10% by weight. Further, the first water-soluble polymer compound is preferably adjusted to be 0.03 to 5 parts by weight per 1 part by weight of cellulose.

According to the first method, the aqueous alkaline polymer solution prepared and prepared in step A above is then mixed in step B with the second water-soluble anionic polymer compound.

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

The second water-soluble anionic polymer compound is preferably used as an aqueous solution, more preferably as an aqueous solution having a concentration of the second polymer compound of 0.5 to 25% by weight, particularly preferably 2 to 22% by weight. To be It is preferable that the aqueous solution has a viscosity at 20 ° C. of 3 to 50,000 centipoise, particularly 5 to 30,000 centipoise.

The alkaline polymer aqueous solution and the second water-soluble anionic polymer compound are 0.3 to 100 parts by weight, more preferably 1 to 45 parts by weight, of the second polymer compound per 1 part by weight of the cellulose in the alkaline polymer solution. Part, particularly preferably 4
Used at ~ 20 parts by weight and mixed. Mixing
It is advantageous to carry out at a temperature lower than the boiling point of carbon disulfide contained in the aqueous alkaline polymer solution, and more preferably at a temperature in the range of 0 to 40 ° C.

According to the research conducted by the present inventor, when an acid-decomposable inorganic salt such as calcium carbonate is added as a dispersant in the aqueous alkaline polymer solution in step A, for example, 0.5 to 5% by weight, It was revealed that the morphology of the fine particles in the fine particle dispersion liquid produced in the process is stably and satisfactorily maintained.

Examples of the second water-soluble anionic polymer compound include the same compounds as the above-exemplified compounds of the anionic first water-soluble polymer compound. The second water-soluble anionic polymer compound may be the same as or different from the first water-soluble polymer compound.

According to the present method for producing coagulated fine particles, the fine particle dispersion liquid of the alkaline polymer aqueous solution generated in the step B is then coagulated in the step C.

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

The solidification by heating can be advantageously carried out at a temperature not lower than the boiling point of carbon disulfide contained in the aqueous alkaline polymer solution, for example, at a temperature of 50 ° to 90 ° C. In the case of coagulation with a coagulant, it is not necessary to raise the temperature to such a level, and coagulation can usually be carried out at a temperature of 0 to 40 ° C. As the coagulant, for example, lower aliphatic alcohols, alkali metal salts or alkaline earth metal salts of inorganic acids, and combinations thereof with a third water-soluble polymer compound are preferably used. The lower aliphatic alcohol may be linear or branched, and has a carbon number of 1 such as methanol, ethanol, iso-propanol, n-propanol and n-butanol.
~ 4 aliphatic alcohols are preferably used. Examples of alkali metal salts of inorganic acids include Na, such as NaCl and Na ₂ SO ₄ .
Salts and K salts such as K ₂ SO ₄ are preferable, and alkaline earth metal salts are preferably Mg salts such as MgSO ₄ and Ca salts such as CaCl ₂ .

As the third water-soluble polymer compound, for example, nonionic and anionic polymer compounds are preferably used. As the third water-soluble polymer compound, it is particularly desirable to use the same one as the second anionic polymer compound used in step B. The illustration of the third water-soluble polymer compound will be understood from the illustration of the first water-soluble polymer compound.

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

Next, the second method for producing the solidified viscose fine particles used in the present invention will be described.

According to the second method, as described above, in step A, an aqueous alkaline polymer solution of cellulose xanthate and the other first water-soluble polymer compound is prepared, and in step B, fine particles of the alkaline polymer aqueous solution are prepared. A dispersion is produced and in step C fine particles containing cellulose are produced. In this respect, it is as described above that it is basically the same as the first manufacturing method. The step A of preparing the alkaline polymer aqueous solution of cellulose xanthate and the other first water-soluble polymer compound is carried out in the same manner as the method described in the description of the first production method. For example, as the xanthate and the other first water-soluble polymer compound to be used, the same ones as those described in the first production method are used.

The step B of producing a fine particle dispersion of an alkaline polymer aqueous solution is carried out with an alkaline polymer aqueous solution and a number average molecular weight of 1500.
It is carried out by mixing the above water-soluble polyethylene glycol or polyethylene glycol derivative.

The high molecular weight polyethylene glycol or polyethylene glycol derivative used has a number average molecular weight of 1,500 or more as described above, and preferably 1,500 to 40.
It has a number average molecular weight of 10,000.

As the polyethylene glycol derivative, for example, only a hydroxyl group at one end of polyethylene glycol has 1 to 1 carbon atoms.
8 water-soluble compound blocked with an alkyl group having 8 carbon atoms, a phenyl group substituted with alkyl having 1 to 18 carbon atoms, or an acyl group having 2 to 18 carbon atoms, or an ABA 'type block copolymer (A, A'is the same or different and represents a polyethylene oxide block, and B represents a polypropylene oxide block). 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 Examples thereof include polyoxyethylene block-polyoxypropylene block-polyoxyethylene block and the like.

Among polyethylene glycol and its derivatives, polyethylene glycol is more preferable and has a number average molecular weight of 6,00.
More preferably from 0 to 200,000, the number average molecular weight is 8,000
Especially preferred are those with a number average molecular weight of 10,000.
Those of up to 30,000 are especially preferable. The polyethylene glycol derivative preferably has a number average molecular weight of 1,500 to 16,000.

According to the second method, in step B, the aqueous alkaline polymer solution and the water-soluble high-molecular-weight polyethylene glycol or its derivative are first mixed. For the mixing, any means capable of producing a fine particle dispersion of an alkaline aqueous polymer solution can be used. The specific means is as described in the description of the first manufacturing method.

The water-soluble high-molecular-weight polyethylene glycol or its derivative is preferably used as an aqueous solution, more preferably the concentration of the polyethylene glycol or its derivative is 0.5 to 6
0% by weight, particularly preferably 5 to 55% by weight, especially 10 to
Used as a 40% by weight aqueous solution.

The alkaline polymer aqueous solution and polyethylene glycol or polyethylene glycol derivative are 1 to 30 parts by weight, more preferably 2 to 28 parts by weight, particularly preferably 4 to 24 parts by weight, and particularly preferably 4 to 24 parts by weight, per 1 part by weight of cellulose. It is used in 8-16 parts by weight and mixed. The temperature at the time of mixing is not particularly limited, but the mixing is preferably carried out at a temperature lower than the temperature at which the fine particle dispersion of the alkaline polymer aqueous solution is formed. A fine particle dispersion of an alkaline polymer aqueous solution is formed at a temperature of 55 ° C. or higher. At temperatures below 55 ° C., it is not possible to obtain a fine particle dispersion of the basic aqueous alkaline polymer solution which can give the desired fine cellulose particles.

According to the second method, the fine particle dispersion of the alkaline polymer aqueous solution generated in step B is then coagulated in step C.

Further, the reaction of the coagulation is carried out at a temperature equal to or higher than the temperature at the time of forming the dispersion liquid. Both the coagulation by heating and the coagulation using a coagulating agent are preferably carried out at a temperature of 60 ° C to 90 ° C.

The coagulant and the use ratio thereof are the same as those described in the explanation of the first production method.

When a combination with polyethylene glycol or a derivative thereof is used as the coagulant, it is possible to prevent the concentration of polyethylene glycol or a derivative thereof in the system from decreasing due to the addition of the coagulant. There is an advantage that the liquid can be solidified stably.

According to the method of the present invention, in the first step, a part of the water is removed from the solidified viscose fine particles having the above composition.

The coagulated viscose fine particles obtained by the first method and the second method as described above substantially consist of spherical or oblong particles having an average particle diameter of 400 μm.
It has a composition of 0 to 60% by weight (converted to cellulose), 90 to 35% by weight of water, and 0 to 5% by weight of a water-soluble polymer compound.
The composition of each component of the coagulated viscose fine particles referred to herein is n-adhered by washing and replacing water and water-soluble polymer compound adhering to the surface of the fine particles with an excess of n-hexane and drying at 50 ° C. for 60 minutes. After removing hexane, the fine particles are mixed with 10
It is dried at 5 ° C. for 3 hours to obtain a cellulose component. When the water-soluble polymer compound is contained, it is washed with water in advance when the cellulose component is obtained to remove the contained polymer compound.

The coagulated viscose fine particles used in the first step are those in which water or a water-soluble polymer compound is attached to the particle surface or are washed with n-hexane to remove water or a water-soluble polymer compound on the particle surface. It is in the state of being. For removing water from the coagulated viscose fine particles, for example, a concentrated aqueous solution of an inorganic salt or a hydrophilic medium is used.

A saturated or supersaturated aqueous solution is preferably used as the concentrated aqueous solution of the inorganic salt. Inorganic salts are sodium sulfate, ammonium sulfate, calcium chloride and the like.

The hydrophilic medium is, for example, butanol or isobutyl alcohol as an aliphatic alcohol, ethylene glycol or glycerin as a polyhydric alcohol, diethyl ketone as a ketone, dimethylformamide or acetamide as an acid amide.

Removal of water is preferably carried out at a temperature of 30 to 90 ° C, more preferably 50 to 80 ° C.
The slower the removal of water, the better, and the temperature is appropriately selected depending on the amount of water in the solidified viscose particles used.
If it is carried out at a temperature of ℃ or more, the water is rapidly removed, which is not preferable.

According to the present invention, the coagulated viscose fine particles from which a part of the water has been removed in the first step are then neutralized with an acid in the second step to convert the viscose into cellulose.

As the acid used as the neutralizing agent, strong inorganic acids such as sulfuric acid and hydrochloric acid are preferably used.

The neutralizing agent is used in an amount sufficient to neutralize viscose,
Convert to cellulose.

The water-soluble polymer compound is removed during the removal or neutralization of the water, but the water-soluble polymer compound can be removed by further treatment in the third step. The water-soluble polymer compound is removed by washing with water or methanol, for example. For a more complete removal,
It is preferable to carry out a combination of hot water washing and methanol washing.

Next, in the fifth step, if necessary, the cellulose fine particles are separated from the mother liquor, and if necessary, desulfurization, pickling, washing with water or drying.

Desulfurization can be performed with an aqueous alkali solution such as caustic soda and sodium sulfide. If necessary, in order to remove the residual alkali, it is then pickled with dilute hydrochloric acid or the like, washed with water and dried.

(Effect of the Invention) As described above, the fine cellulose particles of the present invention substantially consist of type II cellulose, have a crystallinity of 5 to 35% as determined by X-ray diffractometry, and have an average particle diameter of 300 μm.
It consists essentially of spherical or oblong particles of m or less, and has a molecular weight exclusion limit of 3 with polyethylene glycol.
Since it is 000 or less, it is relatively stable to chemicals and has no toxicity, and therefore it can be suitably used as a packing material for liquid chromatography, for example.

(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 first.

<Measurement Method of Crystallinity> Textile Society of Japan, Volume 19, No. 2 (1963), pp. 113-
It is determined by the method of measuring the crystallinity of cellulose by the X-ray diffraction method described on page 119. That is, the X-ray diffraction curve for 2θ from 5 ° to 45 ° is taken and calculated by the following formula.

Here, T ′ = {(a + C) −b} × K K = 0.896 (a non-progressive scattering correction coefficient of cellulose) C = c−a a: diffraction curve of amorphous starch (2θ = 5 to 45 °) )
Area, b: air scattering curve (2θ = 5 to 45 °) area, c: sample diffraction curve (2θ = 5 to 45 °) area, <average degree of polymerization> according to the method described in JIS L-1015. I asked for it.

<Copper Value> The copper value was determined according to the method described in JIS-P-1801-1961.

<Average particle size measuring method> About 0.1 g of a sample is taken, put in 25 ml of pure water, stirred and dispersed, and measured by a light transmission type particle size distribution measuring device.

Example 1 500 g of softwood pulp was immersed in 20 liters of 20 l of a 18 wt% caustic soda solution for 1 hour and squeezed 2.8 times. Grind for 1 hour while heating from 25 ° C to 50 ° C,
After aging, 33% by weight of carbon disulfide (165 g) was added to cellulose and sulfided at 25 ° C. for 1 hour to give cellulose xanthate. The xanthate was dissolved in a caustic soda aqueous solution to obtain viscose. The viscose has a cellulose concentration of 9.3% by weight, a caustic soda concentration of 5.9% by weight, and a viscosity.
It was 6,200 centipoise.

60 g of the above-prepared viscose and 240 g of an aqueous solution of sodium polyacrylate (polymer concentration 12% by weight, molecular weight 50,000) as an anionic polymer compound were put in a 500 ml flask to make the total amount 300 g. At a liquid temperature of 30 ° C, a lab stirrer (Yamato Scientific Co., Ltd .: MODEL LR-51B,
(Rotating blade 7 cm) Stir at 600 rpm for 10 minutes to generate fine particles of viscose, then, while stirring, raise the liquid temperature from 30 ° C to 70 ° C in 15 minutes and maintain at 70 ° C for 10 minutes. Then, the viscose fine particles were solidified. The coagulated viscose particles were centrifugally dehydrated (30
00G) and separated from the mother liquor. The obtained coagulated viscose particles have a particle size of 80 μm and a cellulose component of 45% by weight.
The water content (converted to cellulose) was 55% by weight.

Then, the coagulated viscose particles were dehydrated in a saturated sodium sulfate solution at 80 ° C. for 60 minutes. The resulting dehydrated and coagulated viscose particles contained 60% by weight of a cellulose component (converted to cellulose) and 40% by weight of water. Then, the dehydrated and coagulated viscose fine particles were neutralized and regenerated with 100 g / l of sulfuric acid to convert viscose into cellulose. Then, after separating the cellulose fine particles from the mother liquor through a 1G4 type glass filter, 50 ° C,
Desulfurize with about 2 liters of 2 g / l caustic soda solution, neutralize with 2 g / l sulfuric acid solution, and wash with a large excess of water.
After drying at 5 ° C for 5 hours, fine cellulose particles were obtained. The characteristics of the obtained fine cellulose particles are shown in Table 1.

Example 2 Coagulated viscose particles (particle size 80 μm obtained in Example 1
m, 45% by weight of cellulose component, 50% by weight of water) 80
Dehydration treatment was performed in a saturated ammonium chloride solution at 60 ° C. for 60 minutes. The resulting dehydrated and coagulated viscose particles contained 55% by weight of cellulose component and 45% by weight of water.

Then, in the same manner as in Example 1, fine cellulose particles were obtained. The characteristics of the obtained fine cellulose particles are shown in Table 2.

Example 3 Coagulated viscose particles obtained in Example 1 (particle size 80 μ,
Cellulose component 45% by weight, water 55% by weight) at 80 ° C
It was dehydrated in ethylene glycol for 60 minutes. The dehydrated and solidified viscose particles thus obtained had a cellulose component 61.
% By weight and 49% by weight in water. Then, in the same manner as in Example 1, fine cellulose particles were obtained. The characteristics of the obtained fine cellulose particles are shown in Table 3.

Example 4 The xanthate obtained in Example 1 was dissolved in a caustic soda aqueous solution, and then polyethylene glycol (molecular weight 6000) was used.
50 g was added and dissolved to prepare an alkaline polymer aqueous solution of cellulose xanthate and polyethylene glycol. The alkaline polymer aqueous solution has a cellulose concentration of 9.3.
% By weight, caustic soda concentration by 6.1% by weight, polyethylene glycol by 0.9% by weight, and viscosity 7400 centipoise. 60 g of the adjusted alkaline polymer aqueous solution and 240 g of an aqueous solution of sodium polyacrylate as an anionic polymer compound (polymer concentration 12% by weight, molecular weight 50,000)
Was placed in a 500 ml flask and the total amount was 300 g.
In the same manner as in Example 1, the viscose fine particles containing polyethylene glycol were coagulated. The coagulated viscose particles were separated from the mother liquor by a centrifugal dehydrator (3000G). The obtained solidified viscose particles have a particle size of 85μ.
m, 45% by weight of the cellulose component, 53% by weight of water, and 2% by weight of polyethylene glycol.

Next, the coagulated viscose particles were dehydrated in a saturated sodium sulfate solution at 80 ° C. for 60 minutes. The resulting dehydrated and coagulated viscose particles contained 60% by weight of cellulose component, 39% by weight of water and 1% by weight of polyethylene glycol.

Then, the dehydrated and coagulated viscose particles containing polyethylene glycol were neutralized and regenerated with 100 g / l of sulfuric acid to convert viscose into cellulose. After separating the cellulose glycol fine particles containing polyethylene glycol from the mother liquor, it is desulfurized at 50 ° C. with about 2 l of a 2 g / l caustic soda aqueous solution, neutralized with a 2 g / l sulfuric acid aqueous solution, and then washed with a large excess of water to obtain the fine particles. Polyethylene glycol was removed from the solution and dried at 105 ° C. for 5 hours to obtain fine cellulose particles.

The characteristics of the obtained fine cellulose particles are shown in Table 4.

Example 5 In Example 4, polyethylene glycol (molecular weight 6,
000) and sodium polystyrene sulfonate (molecular weight 10,000) was used, and the characteristics of the fine cellulose particles obtained in the same manner as in Example 4 are shown in Table 5.

Example 6 30 g of viscose obtained in Example 1 and 270 g of an aqueous solution of sodium polystyrene sulfonate (polymer concentration 14% by weight, molecular weight 500,000) as an anionic polymer compound were placed in a 500 ml flask and the total amount was 300 g. did. At a liquid temperature of 30 ° C, a lab stirrer at 1000 rpm is stirred for 10 minutes to generate fine particles of viscose, and then the liquid temperature is continuously changed from 30 ° C to 70 ° C while stirring.
The temperature was raised to 15 minutes and maintained at 70 ° C. for 10 minutes to solidify the viscose fine particles. The obtained coagulated viscose particles have a particle size of 20 μm and a cellulose component content of 50% by weight.
The water content (converted to cellulose) was 50% by weight.

The characteristics of the fine cellulose particles obtained in the same manner as in Example 1 are shown in Table 6 below.

Example 7 The fine cellulose particles of Examples 1 to 6 were each 8 mm in ^diameter.
Flow rate of water into a 25 cm stainless steel column with water as the packing liquid 2.
It was filled at 0 ml / min for 30 minutes. Next, using each packed column as a separation column, a standard polyethylene glycol having a known molecular weight under the following analysis conditions was used to prepare a molecular weight calibration curve showing the relationship between the elution time and the molecular weight. The exclusion limit molecular weight and the partition index obtained from this result are shown in Table 7.

Analysis conditions 1. Pump HLC-803D manufactured by Toyo Soda Kogyo Co., Ltd. 2. Eluent pure water 3. Flow rate 1.0 ml / min 4. Temperature room temperature 5. Detector RI detector As an example of these, FIG. 1 shows the relationship (molecular weight calibration curve) between the molecular weight of polyethylene glycol and the elution time for the fine cellulose particles of Run No. 1 and No. 4.

Further, Example 1 (Run No. 1: 66 μm), Example 6 (R
un No.6: 12μm) each 8mm
^It was packed in a ^φ × 25 cm stainless steel column, pure water was used as an eluent, and the relationship between the flow rate and the column pressure was investigated. As shown in FIG. 2, particles of Run No. 6 having a particle diameter of 12 μm can be pressurized up to 80 kg / cm ² and can be used at a high flow rate.

[Brief description of drawings]

FIG. 1 shows the fine cellulose particles of the present invention (Example 1: Ru
n No. 1, Example 4: (obtained in Run No. 4)) is a graph showing the relationship between the elution time and the molecular weight showing the separation performance as a packing material for liquid chromatography. FIG. 2 shows the fine cellulose particles of the present invention (Example 1: Ru
FIG. 7 is a graph showing the relationship between the column pressure and the flow rate showing the pressure resistance performance of the packing material for liquid chromatography (n No. 1, Example 4: those obtained in Run No. 6).

Claims (22)

[Claims] 1. A composition consisting essentially of (a) type II cellulose, (b) having a crystallinity of 5 to 35% as determined by an X-ray diffraction method, and (c) an average particle size of 300 μm or less. It consists essentially of spherical or oblong particles, and (d) has an exclusion limit molecular weight of 3,0 by polyethylene glycol.
Fine cellulose particles characterized by having a particle size of 00 or less. 2. The fine cellulose particles according to claim 1, having a crystallinity in the range of 7 to 33%. 3. The fine cellulose particles according to claim 1, having a crystallinity in the range of 10 to 30%. 4. The microcellulosic particles according to claim 1, which consist essentially of spherical or oblong particles having an average particle size of 1 to 200 μm. 5. The microcellulosic particles according to claim 1, which consist essentially of spherical or oblong particles having an average particle diameter of 2 to 150 μm. 6. The projection view of an oblong particle is an ellipse, an elongated circle, a peanut shape, or an oval shape.
The fine cellulose particles according to the above item. 7. The fine cellulose particles according to claim 1, having an exclusion limit molecular weight of 2,500 or less. 8. The fine cellulose particles according to claim 1, having an exclusion limit molecular weight of 2,000 or less. 9. The fine cellulose particles according to claim 1, wherein the degree of polymerization of the cellulose is in the range of 100 to 700. 10. The following formula Where V _D is the elution volume of blue dextran (molecular weight 2 million)
(ml) and V _E is the elution volume (ml) of ethylene glycol, wherein the fractionation index (F) defined by is at least 0.6. . 11. The fine cellulose particles according to claim 1, having a fractionation index (F) of at least 0.8. 12. The fine cellulose particles according to claim 1, wherein the fraction index (F) is at most 2. 13. The microcellulosic particles according to claim 1, which have a pressure resistance when wet of at least 5 kg / cm ² . 14. The fine cellulose particles according to claim 1, which have a pressure resistance when wet of at least 10 kg / cm ² . 15. The fine cellulose particles according to claim 1, wherein the copper value of the cellulose is 3 or less. (1) The following composition: Cellulose component 10 to 60% by weight (converted to cellulose) Water 90 to 35% by weight, and water-soluble polymer compound 0 to 5% by weight, solidified viscose fine particles are treated with an inorganic salt. Of the water contained in the coagulated viscose fine particles is removed by contacting it with a concentrated aqueous solution or a hydrophilic medium, and then (2) the resulting dehydrated coagulated viscose fine particles are neutralized with an acid. Then, the viscose is converted into cellulose, and, if necessary, (3) during the removal of water in the step (1), during the neutralization in the step (2) or thereafter, from the fine particles produced in each step. The water-soluble polymer compound is removed, and if necessary, (4) the fine particles obtained in the step (2) or (3) are separated from the mother liquor, and if necessary, desulfurization, pickling, washing with water or drying, Special And (a) consists essentially of type II cellulose, (b) has a degree of crystallinity of 5 to 35% as determined by X-ray diffractometry, and (c) is spherical or has an average particle size of 300 μm or less. It consists essentially of oblong particles, and (d) has a molecular weight exclusion limit of 3,0 by polyethylene glycol.
A method for producing fine cellulose particles, which is 00 or less. 17. The method according to claim 16, wherein the coagulated viscose fine particles used in the step (1) have an average particle diameter of 400 μm or less. 18. The method according to claim 16, wherein the concentrated aqueous solution of the inorganic salt is a saturated or supersaturated aqueous solution of the inorganic salt. 19. The hydrophilic medium is an aliphatic alcohol,
The method according to claim 16, which is a polyhydric alcohol, a ketone, or an acid amide. 20. The removal of water in the step (1) is carried out by 30 to 90.
A method according to claim 16 carried out at a temperature in the range of ° C. 21. The method according to claim 16, wherein the acid used for neutralization in the step (2) is a strong inorganic acid. 22. The method according to claim 21, wherein the strong inorganic acid is hydrochloric acid or sulfuric acid.