JPH0931102A - Method for granulating carboxymethylcellulose ether alkali salt and granular caroboxymethylcellulose ether alkali salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain granular carboxymethylcellulose ether alkali salt (hereinafter abbreviated to CMC) which can give a dry powder having a uniform particle diameter, suppressed in the formation of a fine powder and having a high bulk density and excellent handleability by disintegrating lump CMC in water- containing isopropyl alcohol. SOLUTION: CMC is granulated in a liquid by disintegrating lump CMC in isopropyl alcohol. In the above granulation, the amounts of the components in the granulation system are desirably such that 5-30wt.%, based on the entire system, CMC, 55-80wt.% isopropyl alcohol and 15-40wt.% water are used. The granular CMC obtained by this method has a content of particles with particle diameters in the range of 149-2,000μm of 80wt.% or above based on the total particles and a bulk density of 0.4g/ml or above.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for granulating an alkali salt of carboxymethyl cellulose ether (hereinafter referred to as “CMC”) characterized by in-liquid treatment, and a granular CMC which is a granulated product, In the powder management of CMC, the purpose is to protect the working environment by preventing dust generation, to automate loading and unloading at the time of transfer, to prevent adhesion to the container, and to improve the solubility in water and to excel in rapid dissolution, in various fields. The present invention relates to granular CMC capable of improving the handling property in the above and a granulation method of CMC.

[0002]

2. Description of the Related Art CMC conventionally used for various purposes
Is produced by using pulp or the like as a raw material, performing an etherification reaction and then an etherification reaction, then neutralizing with acetic acid or the like, and removing liquid by filtration to produce crude CMC. Then, on this crude CMC,
Desalination purification is performed by adding an aqueous methanol solution having a water content of 30% by weight (hereinafter abbreviated as "%"). Next, the purified CMC that has been filtered is produced by drying with hot air and crushing.

[0003]

However, the CMC obtained by the above process has the following problems.

The particle size of the obtained CMC is not uniform,
In addition, since a large amount of fine powder (particle diameter of 75 μm or less) in a fibrous form is contained, there is a lot of powder standing and there is a problem in workability. When the fine CMC is used, dust is generated, which adversely affects the working environment. Since the particle size of the obtained CMC is non-uniform and there are many fibrous fine powders, when dissolved in water, a continuous powder is generated,
Moreover, the solubility is poor and it takes a long time to dissolve. Since CMC is a fine powder, it easily absorbs moisture and solidifies at a product pressure to deteriorate handleability.

Due to the problems as described above, granulation of CMC having good fluidity and compact size has been studied. For example, as a granulation method of CMC, CM
In the production process of C, after the reaction of CMC, the solvent used in this reaction is separated to produce a so-called dry and rough crude CMC. And to this crude CMC,
While stirring and mixing, 1 to 2 times the amount of water is sprayed to CMC to partially dissolve and solidify (keratinize) fibrous CMC to prepare granulated CMC. Then, for the purpose of dehydration, the granulated CMC is prepared by immersing the granulated CMC in a large amount of methanol, separating and dehydrating the methanol, and then drying to obtain granular CMC to be a granulated product. (U.S. Pat. No. 2,715,124). However, in the above-mentioned granulation method, gel CM produced by spraying water as described above is used.
Since C is not uniform, there is a problem that a granulated product having a uniform particle size cannot be obtained. Also, as mentioned above,
Since the gel-like CMC grows in close contact with each other and has a granular shape, the granular state is formed into particles having irregularities formed on the surface such as sucrose, and as a result, the fluidity is deteriorated. ing. Further, since CMC having a high degree of ether substitution has high water solubility and is easily dissolved, there is a problem that the CMC adheres strongly to the apparatus and the CMC does not stick to particles and cannot be granulated. In addition, as a whole, the above-mentioned granulation method has a poor yield of product CMC and is costly.

On the other hand, the applicant of the present application has previously proposed a method in which a solvent-water containing slurry of CMC is made to flow on a rotating disk to be atomized and then spray-dried for granulation ( Japanese Patent Application No. 6-215058). However, the CMC granulated product obtained by this method has a low bulk density,
It was found that CMC is not preferable in terms of fluidity and compactness.

The present invention has been made in view of the above circumstances, and obtains a CMC which has a uniform particle size of the dry powder to be obtained, suppresses the generation of fine powder, and has a high bulk density and excellent handling property. Granulation method of CMC capable of
And the purpose is to provide granular CMC.

[0008]

In order to achieve the above object, the present invention has a first aspect of a method for granulating CMC in which liquid CMS is granulated by crushing massive CMC in hydrous isopropyl alcohol. The second gist is a granular CMC containing 80% or more of particles having a particle size of 149 to 2000 μm and having a bulk density of 0.4 g / ml or more.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, regardless of the degree of ether substitution, CM of high quality can be obtained from low ether substitution degree to high ether substitution degree, that is, even CMC having high water solubility.
In order to obtain a granulated product of C, it is a method of granulating in a liquid by crushing massive CMC in isopropyl alcohol containing water (hereinafter referred to as "IPA"). In this in-liquid granulation, hydrous IPA containing massive CMC as a raw material
A system consisting of a solution is used in which the CMC content is 5 to 3 of the total system.
By setting 0%, the content ratio of IPA to 55 to 80% of the whole system, and the water content ratio to 15 to 40% of the whole system, the bulk density is uniform and the generation of fine powder is suppressed. It is more effective because a CMC granulated product with high (granular CMC) is obtained. Further, in the submerged granulation method, lumpy C
By carrying out the Reynolds number (Re) showing the flow characteristics of the water-containing IPA solution system containing MC under a condition of 1000 or more, a uniform particle size and a particle size of 75 μm can be obtained.
The following granular CMC in which generation of fine powder is suppressed can be obtained.
Therefore, when the obtained granular CMC is dissolved in water,
It does not cause the generation phenomenon of powdered powder that has been seen in the past, but dissolves quickly in water. As a result, the dissolution time during use in various applications is greatly shortened, and further, handling is excellent because there is little powdering and good fluidity. Further, when the granular CMC is used, the generation of dust is small and the working environment is not deteriorated.

The granular CMC has a particle size of 149-
80% or more of all particles are present within the range of 2000 μm,
In addition, when the bulk density is set to 0.4 g / ml or more, the fluidity and the solubility are excellent, the dusting problem does not occur, and the handling property becomes good.

Next, the present invention will be described in detail.

In the CMC granulation method of the present invention, the target CMC has an average ether substitution degree of 0.4 to 3.0.
It is also applicable to any CMC in that it can also be applied to CMC having a binding property, and in particular, CMC having a highly hydrophilic average ether substitution degree of 1.5 to 3.0.
Is a suitable target. Also, as the type of alkali salt,
Examples thereof include sodium salt, potassium salt, ammonium salt and the like, but sodium salt is usually used. Furthermore, CMC
May be either crude CMC or purified CMC obtained by using this crude CMC and removing the by-product salt. It is preferable to use purified CMC because the purification effect is poor if desalted and purified after granulation according to the present invention.

The CMC granulation method of the present invention is carried out, for example, as follows. That is, a crude CMC is prepared by using a conventionally known method of using pulp as a raw material, performing a neutralization treatment via an alcerization reaction and an etherification reaction, and performing deliquoring filtration. On the other hand, water and IPA
Was prepared in a weight ratio of water / IPA = 40/60 to 70/30 to prepare a mixed solvent (water-containing IPA), and the mixed solvent was added to the crude CMC.
5 to 20 times the weight of the
Desalting treatment is performed by stirring for 1 hour (desalting step). And
The liquid is deliquored using a centrifuge, a decanter, a screw-type continuous liquid separator, a filter, etc. to produce wet purified CMC. The purified CMC produced here has a CMC solid content of 2
0-40%, water 45-65%, IPA 15-35%
It is a lump-like material having a binding property and having elasticity such as agar-like to konnyaku-like. The bulk purified CMC thus obtained is 45 to 65% in the desalting step.
It has a high water content.

Next, the wet and lump-shaped purified CMC obtained above and IPA (solvent) having a water content of 20% or less are put into a predetermined mixer to remove the residual water in the purified CMC. The purified CMC is dehydrated by transferring it to a solvent that is IPA. In addition to performing this dehydration treatment, stirring is performed in a mixer with a blade to crush the refined CMC in a lump form, thereby finely cutting and performing in-liquid granulation. Since the purified CMC has a high water content, IPA having a water content of 20% or less used in the above-mentioned liquid granulation is used to adjust the water content to a range of 5 to 30%. That is, IPA having a water content of 20% or less can prevent re-binding during granulation, and at the same time refined CM
It is a useful solvent that can perform the dehydration treatment of C. The use of other organic solvents other than IPA, for example, lower alcohols such as methanol and ethanol is
Since it has high water solubility and adhesiveness, it is not preferable because it dissolves and it becomes impossible to granulate in liquid. Also, the use of butanol is not preferable because it has a strong odor and is difficult to be deaerated, which is economically expensive.

Next, the CMC granulated in the liquid is subjected to a solvent removal by a centrifuge, and subsequently dried at 60 to 110 ° C. for 5 to 60 minutes by using a fluidized dryer or a vacuum dryer. In this way, granular CMC is obtained.

In the above-mentioned in-liquid granulation, a mixer type mixer as shown in FIG. 1 can be used as a mixer for introducing purified CMC and water-containing IPA. That is, in this mixer, in the water-containing IPA solution 3 stirred at a predetermined Reynolds number, the knife-type stirring blade 1 is rotated to cut the agglomerated purified CMC 2 into small pieces, and granulation in the liquid is performed while rotating. .

In the above in-liquid granulation, the purified CMC in a lump form
It is preferable to perform stirring with a strong blade of which the Reynolds number (Re) of the value showing the flow characteristics of the water-containing IPA solution 3 system containing 2 is 1000 or more. The Reynolds number (R
e) is 4000-30000. That is, by setting the Reynolds number (Re) to 1000 or more,
It becomes possible to obtain granular CMC having a uniform particle size and suppressing generation of fine powder having a particle size of 75 μm or less. In addition,
The Reynolds number (Re) is calculated by the following equation (1).

[0018]

[Equation 2] Re = (D · U · ρ) / μ (1) [In the formula (1), D is a blade diameter (cm), U is a blade peripheral speed (cm / sec), and ρ is a liquid. Density (g / cm ³ ), μ
Is the liquid viscosity (g / cm · sec)]

Further, in the above-mentioned in-liquid granulation, the number of revolutions at the time of stirring is in the range of 100 to 2000 rpm, and is appropriately set according to the amount of the bulk refined CMC to be charged. Furthermore, the temperature of the bulk purified CMC to be charged is 10 to 50 ° C.
In addition, the stirring time is set to 5 to 30 minutes.

When granulating in liquid, purified C
The MC may be supplied continuously or may be added batchwise. Further, they may be added all at once in a batch system, and the supply amount is not limited.

The granulation forming process in the submerged granulation process will be described in detail.

That is, the CMC after the ether reaction during the production of crude CMC is in a fibrous state and is bulky and has a low density. For the purpose of removing impurities such as by-product salts contained in the crude CMC, desalting purification is usually performed in a low water content solvent. However, in the present invention, as described above,
The water content should be 40-
Purify by desalting with 70% high water content IPA. This high water content IP
When desalting treatment is performed with A and the filtrate is separated, the water content is 45 to 65.
% Wet solid lump purified CMC is obtained. In this step, since the fibrous CMC contains water, it fuses and changes from agar-like to konnyaku-like massive solid matter. This solid does not dissolve in the IPA-based solvent, and the good dispersibility is maintained by stirring.

Then, after separating the filtrate, the konjac-shaped refined CMC is charged together with 20% or less of water-containing IPA (solvent) for the purpose of in-liquid granulation and dehydration of the refined CMC. Rotate and stir mix. Then, the massive CMC is immediately crushed in the liquid, and granulated and cut to have a particle size of about 1 mm. Here, at the same time as crushing,
Dehydration proceeds due to the transfer of water to IPA, and spherical particles are obtained by rotation.

In the granular CMC thus obtained, 80% or more of all particles have a particle size within the range of 149 to 2000 μm, and do not contain fine powder with a particle size of 75 μm or less. . Alternatively, even if a fine powder having a particle size of 75 μm or less is contained, it is contained in a very small amount that does not adversely affect the dust and reduce the solubility due to the generation of the continuous powder. The measurement of the above particle size is carried out using a standard sieve (JIS
Z8801) and the overall particle size distribution can be confirmed. The granular CMC having such a particle size distribution has a high bulk density of 0.4 g / ml or more, particularly 0.4 to 0.8 g / ml.

Next, examples will be described together with comparative examples.

First, a raw material for the granulation of the present invention,
Three types of purified CMC having different etherification degrees (DS) were prepared.

[Preparation of Purified CMC by Solvent Method] Raw material pulp [NDSP (sulfate method pulp) manufactured by Kojin Co., Ltd.] was pulverized by a pulverizer to a diameter of 0.3 mm to obtain a pulp having a water content of 5%. Subsequently, 0.8 part of this crushed pulp was added to a 30-liter SUS reaction kettle filled with water-containing IPA consisting of 20 parts by weight of IPA (hereinafter abbreviated as “part”) and 2 parts of water, and the mixture was added at about 20 ° C. at about 20 ° C. Stir for 20 minutes.
And 100% caustic soda flakes 1.1
Parts were added over 5 minutes and the mixture was stirred at 30 ° C. for 60 minutes to carry out an alcelization reaction. Then, 2.4 parts of an IPA solution containing 50% monochloroacetic acid was added thereto over 10 minutes. Subsequently, the temperature was raised to 70 ° C. over about 30 minutes, then cooled again to 30 ° C., 1.1 parts of 100% caustic soda flake product was added over 5 minutes, and after 30 minutes, 50% monochloroacetic acid was added. A second addition of 2.4 parts of the contained IPA solution was made over 10 minutes. Then 70 minutes over 30 minutes
The temperature was raised to 0 ° C., and the etherification reaction was completed for 60 minutes at 70 ° C. After the etherification reaction, the mixture was cooled to 40 ° C. over 10 minutes, and 0.3 part of a 50% aqueous acetic acid solution was added to neutralize excess caustic soda in the system. Then, this is subjected to dehydration filtration with a centrifuge, and the degree of etherification (DS)
8.7 parts of 2.1 crude CMC (sodium salt) was prepared. The composition of this crude CMC is CMC 52%, water 1
It was 9.5% and IPA was 28.5%.

1 part of the above crude CMC, 6 parts of water and 4 parts of IPA
A 60% water-containing solvent was added, and the mixture was stirred at 50 ° C. for 60 minutes for desalting treatment. After that, the liquid was filtered with a centrifuge to remove wet CMC (sodium salt) 0.8.
Got a part. The purified CMC thus obtained was a lump having a solid content of 30%, water of 48% and IPA of 22%, and having agar-like softness and brittleness.

[Preparation of Purified CMC by Solvent Method] Raw material pulp [NDSP (sulfate method pulp) manufactured by Kojin Co., Ltd.] was pulverized by a pulverizer to a diameter of 0.3 mm to obtain a pulp containing 5% of water. Subsequently, 1.0 part of this pulverized pulp was added to a 30-liter SUS reaction kettle filled with water-containing IPA consisting of 25 parts of IPA and 2.5 parts of water, and the mixture was stirred at 20 ° C. for about 20 minutes. And 40 to this
% Caustic soda aqueous solution 1.0 part was added over 5 minutes, and 30 ° C.
The alcerization reaction was performed by stirring for 60 minutes. Next, 0.78 part of an IPA solution containing 50% monochloroacetic acid was added thereto over 5 minutes. Then, it heated up to 70 degreeC over about 30 minutes. The etherification reaction was carried out for 90 minutes at 70 ° C. After the etherification reaction, 1
Cool to 40 ° C. over 0 minutes and add 50% acetic acid aqueous solution 0.3
Parts were added to neutralize excess caustic soda in the system. Then, this was subjected to dehydration filtration with a centrifuge to obtain 2.5 parts of crude CMC (sodium salt) having an etherification degree (DS) of 0.6.
Parts were produced. The composition of this crude CMC is 65
%, Water was 11.4%, and IPA was 23.6%.

1 part of the above crude CMC, 7 parts of water and 3 parts of IPA
70 parts of a 70% water-containing solvent was added, and the mixture was stirred at 50 ° C. for 30 minutes for desalting treatment. After that, the liquid is filtered with a centrifuge and filtered in the form of a wet block CMC (sodium salt) 2.3.
Got a part. The purified CMC thus obtained was composed of 21% solids, 57% water, and 22% IPA, and was a lump having konjac-like elasticity and brittleness.

[Preparation of Purified CMC by Solvent Method] Raw material pulp [NDSP (sulfate method pulp) manufactured by Kojin Co., Ltd.] was pulverized by a pulverizer to a diameter of 0.3 mm to obtain a pulp having a water content of 5%. Subsequently, 1.0 part of this pulverized pulp was added to a 30-liter SUS reaction kettle filled with water-containing IPA consisting of 25 parts of IPA and 2.5 parts of water, and the mixture was stirred at 20 ° C. for about 20 minutes. And 40 to this
% Aqueous caustic soda solution (2.7 parts) over 5 minutes, and the temperature is 30 ° C.
The alcerization reaction was performed by stirring for 60 minutes. Next, 2.3 parts of an IPA solution containing 50% monochloroacetic acid was added thereto over 5 minutes. Then, it heated up to 70 degreeC over about 30 minutes. The etherification reaction was carried out for 90 minutes at 70 ° C. After the etherification reaction, 10
The mixture was cooled to 40 ° C over a period of time, and 0.3 part of a 50% acetic acid aqueous solution was added to neutralize excess caustic soda in the system. Then, this was subjected to deliquoring filtration with a centrifuge to obtain 5.6 crude CMC (sodium salt) having an etherification degree (DS) of 1.5.
Parts were produced. The composition of this crude CMC is 58 CMC.
%, Water was 14.7%, and IPA was 27.3%.

1 part of the crude CMC was mixed with 9 parts of water and 6 parts of IPA.
Part of a 60% water-containing solvent was added, and the mixture was stirred at 50 ° C. for 30 minutes for desalting treatment. Then, the liquid was filtered with a centrifuge to remove wet CMB (sodium salt) 1.4.
Got a part. The purified CMC thus obtained was a lump having konjac-like elasticity and brittleness, having a composition of solid content 26%, water 50%, and IPA 24%.

[0033]

Examples 1 to 15 and Comparative Examples 1 to 6 Using the purified CMC, prepared as described above, granulation according to the present invention was carried out as follows. That is, first, as shown in FIG. 1, a volume 10 provided with a knife-type stirring blade 1
Using a liter large mixer-type mixer (manufactured by Domestic Centrifuge Co., Ltd.), 1 part of the solid content of the lump-refined CMC shown in Table 1 below and 8 times this amount of 10% water-containing IPA were added. The content ratios of CMC, IPA and water in the entire system at this time are shown in Table 1 below. Then, immediately, stirring was started at room temperature (25 ° C.), and the Reynolds number showing the flow of the solution was set to the value shown in Table 2 below, and stirring was performed. The granulation conditions by the above mixer are shown in Table 2 below. The Reynolds number is a value calculated by the equation (1), and each factor required for calculating the Reynolds number, the blade diameter D (cm), the blade peripheral velocity U (cm / sec), and the liquid density ρ. (G / cm ³ ),
Each value of the liquid viscosity μ (g / cm · sec) is also shown in Table 2 below.

[0034]

[Table 1]

[0035]

[Table 2]

As a result of the agitation, the lump purified CMC was hydrated I
At the same time as being crushed into small pieces in the PA liquid and rotating in the liquid, granular CMC formed into small spherical particles was obtained. An optical micrograph of the granular CMC of Example 1 is shown in FIG. As described above, it can be seen that the granular CMC obtained by the in-liquid granulation has a substantially spherical shape as a whole. In addition, a large amount of water contained in the bulk purified CMC was transferred into the IPA solution during the stirring. As a result, the granulated CM
On the C surface, keratinization proceeded with dehydration, and solidification and an increase in density occurred. Therefore, the CMC particles were free-flowing and did not easily adhere to the equipment, and a good CMC granulated product was obtained. The granulation treatment step is performed for 5 to 20 minutes, and can be performed by either a continuous method or a batch method.

After the above granulation treatment, the liquid was separated by a centrifugal separator, and then dried with a warm air dryer at 100 ° C. for 2 hours. In this way, granular CMC was obtained.

[0038]

Comparative Examples 1 to 4 Crude CMCs having different degrees of etherification prepared during the above-mentioned production process of purified CMC were used, and 10 times amount of 20% water-containing methanol was added thereto to carry out desalting and washing twice. , Purified CMC was obtained. Then, the purified CMC was sprayed with water to increase the water content in order to match the water content with that in the above example, and then 8 times the volume of 1 was added.
Granulation was performed with a 0% water-containing methanol system under the conditions shown in Table 3 below using the same mixer as in the above example (Comparative Examples 1 to 3). On the other hand, the deliquored purified CMC is dried with a hot air dryer at 100 ° C. for 2 hours and then pulverized with an impact type fine pulverizer (manufactured by Hosokawa Micron Co., Ltd.) to form granular C.
MC was obtained (Comparative Example 4).

[0039]

[Table 3]

[0040]

Conventional Example A crude CMC having an etherification degree of 1.5, which was produced during the above-mentioned process for producing purified CMC, was used.
A 15-fold amount of 0% water-containing methanol was added, and desalting and washing were performed twice to obtain purified CMC (CM in the purified CMC.
C: 65%, water content 5%, methanol 30%). And
In order to match the water content of this purified CMC with that of the above-mentioned example, water was sprayed to increase the water content to 50%, and a part of the fibrous CMC was melted and solidified (keratinized) to form granulated CMC. did. Subsequently, for the purpose of dehydration, 10 times amount of 100% IPA was added to this CMC, the solvent was separated and dehydrated, and then hot air drying treatment was performed at 60 ° C. to obtain granular CMC. An optical microscope photograph of the obtained granular CMC of the conventional example is shown in FIG. In this way, the obtained granular CM
In C, the grain shape was such that unevenness was formed on the entire surface such as sugary sugar.

In the granular CMCs of the example product, comparative example product, comparative example product and conventional product thus obtained, the state of granular CMC granulated under liquid granulation and the obtained granular CMC The yield and the water content are shown in Tables 4 and 5 below. The yield of the granular CMC is calculated by the following formula.

[0042]

## EQU3 ## Yield (%) = [(pure CMC content) / (purified CMC content)] × 100

Further, the bulk density of each of the obtained granular CMCs,
The content ratio of particles within a particle size range of 149 to 2000 μm and the content ratio of particles having a particle size of 75 μm or less with respect to the entire granular CMC was measured by a standard sieve (JIS Z8801), and the results are shown in Tables 4 and 5 below. Show.

[0044]

[Table 4]

[0045]

[Table 5]

From the measurement of the above call counter,
Standard sieves (JIS Z880) of Example 5 product (ether substitution degree 1.5) and Example 9 product (ether substitution degree 2.1)
FIG. 4 is a chart showing the particle size distribution measured by 1).
(Example 5 product) and FIG. 5 (Example 9 product), respectively, and the numerical values obtained by the measurement are shown in Table 6 (Example 5 product) and Table 7 (Example 9 product) below. The average particle size of the product of Example 5 measured by the above-mentioned call counter was 81.
4.41 μm, standard deviation 381.52 μm, Example 9
The average particle size of the product was 597.28 μm, and the standard deviation was 267.
It was 09 μm.

[0047]

[Table 6]

[0048]

[Table 7]

Further, the solubility and dissolution rate of each CMC thus obtained, dust generation, dust generation amount, adhesion and fluidity were measured and evaluated according to the following methods. The results are shown in Table 8 below.
Shown in

[Solubility and Dissolution Rate of Granular CMC] 1
Put 800 ml of water in a 000 ml beaker, and add C
8 g of MC sample (1% concentration) was added. As a result, ○ was immediately dispersed and quickly dissolved in water, ○ was immediately formed a powdered lump and took a long time to dissolve in water, ×, and the intermediate evaluation was Δ. displayed. Also,
The time until the CMC sample was dissolved was measured by lightly stirring.

[CMC dust generation] CMC sample
A ml screw tube was filled with 1/2 volume, and this was stirred up and down. As a result, ○ if there was no dust of fine powder,
The one in which a large amount of fine dust was generated was indicated as ×, and the one in the above intermediate evaluation was indicated as Δ.

[CMC dust generation amount] 10 g of the CMC sample was put into a 300 ml Meyer flask, and the upper and lower sides of the sample were 3 cm.
After shaking, the floating CMC dust was absorbed by a suction collector equipped with a cylindrical filter paper to measure the amount of dust generation.

[Adhesiveness of CMC] A 1-liter polyethylene bag was filled with 200 g of a CMC sample, left for 1 day, and then, with the bag mouth facing downward, the CMC sample was naturally dropped and taken out from the bag. And the CM that was left in the bag
The amount of C powder was measured and the adhesion rate was calculated.

[Fluidity of CMC] From a height of 20 cm, a CM having a diameter of 10 mm at the lower part of the outlet was passed through a CM.
50 g of the C sample was naturally dropped on the glass plate. And
The diameter of the CMC that dropped and spread in a circle on the glass plate was measured. Naturally, it can be said that a material with a large diameter has high fluidity.

[0055]

[Table 8]

From the results shown in Table 8 above, the products of Comparative Examples are inferior in solubility and produce a large amount of dust. Furthermore, it can be seen that the adhesiveness is high and the fluidity is poor. On the other hand, the comparative example product is superior in each characteristic to the comparative example product. Further, the example products obtained by specifying the Reynolds number to be 1000 or more are very excellent in solubility and fluidity, and moreover,
It is clear that good results were obtained for each property, without the amount of dust generation and the amount of adhesion.

[0057]

INDUSTRIAL APPLICABILITY As described above, the present invention is a method of granulating in-liquid by crushing massive CMC in water-containing IPA. In this in-liquid granulation method, even if CMC having a high degree of hygroscopicity and high water solubility and a high degree of ether substitution is used as a raw material, for example, it is not a method of spraying water as in the conventional method, and therefore unevenness due to dissolution adhesion is formed. Granular CMC with a uniform particle size can be easily produced instead of crushed particles.
Further, the obtained granular CMC has a uniform particle size,
In addition, generation of fine CMC of fibrous CMC having a particle size of 75 μm or less is suppressed.

Then, in this in-liquid granulation, a system consisting of a water-containing IPA solution containing massive CMC as a raw material was prepared.
By setting the content ratio of CMC to 5 to 25% of the whole system, the content ratio of IPA to 70 to 90% of the whole system, and the water content ratio to 5 to 40% of the whole system, a uniform particle size is obtained, and , Granular CMC with high bulk density, which suppresses generation of fine powder
Is obtained and is effective. Furthermore, by performing the above-mentioned in-liquid granulation under a strong stirring condition where the Reynolds number (Re) showing the flow characteristics of a water-containing IPA solution system containing agglomerated CMC is 1000 or more, a uniform particle size is obtained, and Particle size is 75μ
Granular CMC in which generation of fine powder of m or less is suppressed can be obtained. Therefore, when the obtained granular CMC is dissolved in water, the phenomenon of generation of the powdered granules that is conventionally seen does not occur, and the granular CMC is quickly dissolved in water. As a result, the dissolution time when using the granular CMC is significantly shortened, and the fluidity is good, so that the handling property is also excellent. Also, granular CMC
There is little dust generation during use, and the working environment is improved. Moreover, since the obtained granular CMC has good fluidity, it is possible to automate the quantitative supply at the time of use, and it is preferable because it can be automated in the production process of the paper pulp industry, the food industry and the like.

Then, as the granular CMC, a particle size of 149-
80% or more of all particles are present within the range of 2000 μm,
In addition, when the bulk density is 0.4 g / ml or more, the fluidity and the solubility are excellent, the dusting problem does not occur, and the handling property becomes good.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a mixer-type mixer used in the CMC granulation method of the present invention.

FIG. 2 Granular CM of Example 1 product obtained by submerged granulation
It is an optical microscope photograph at a magnification of 50 times showing the particle structure of C.

FIG. 3 is an optical microscope photograph at a magnification of 50 showing the grain structure of granular CMC obtained by a conventional production method.

FIG. 4 is a chart showing an example of the results of measuring the particle size distribution of granular CMC that is a product of Example 5 (ether substitution degree 1.5) by a standard sieve (JIS Z8801).

FIG. 5 is a chart showing an example of a result obtained by measuring the particle size distribution of granular CMC which is the product of Example 9 (ether substitution degree 2.1) with a Coal counter.

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[Procedure amendment]

[Submission date] August 11, 1995

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

[Fig. 2]

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

[Figure 3]

Claims (4)

[Claims] 1. A method for granulating an alkali salt of carboxymethyl cellulose ether, which comprises granulating the massive carboxymethyl cellulose ether alkali salt in a liquid by crushing it in water-containing isopropyl alcohol. 2. A system comprising hydrous isopropyl alcohol containing a lumpy carboxymethyl cellulose ether alkali salt at the time of granulating in the above liquid, wherein the content ratio of the carboxymethyl cellulose ether alkali salt is 5 to 30% by weight of the whole system, The method for granulating an alkali salt of carboxymethyl cellulose ether according to claim 1, wherein the content ratio of isopropyl alcohol is set to 55 to 80% by weight of the whole system and the water content ratio is set to 15 to 40% by weight of the whole system. 3. The Reynolds number (Re) calculated by the following formula (1) showing the flow characteristics of a hydrous isopropyl alcohol solution system containing a lumpy carboxymethyl cellulose ether alkali salt in the crushing in the liquid is 1
The method for granulating an alkali salt of carboxymethyl cellulose ether according to claim 1 or 2, which is 000 or more. [Equation 1] Re = (D · U · ρ) / μ (1) [In the formula (1), D is a blade diameter (cm), U is a blade peripheral speed (cm / sec), and ρ is a liquid. Density (g / cm ³ ), μ
Is the liquid viscosity (g / cm · sec)] 4. A granular carboxymethyl cellulose ether alkali salt containing 80% by weight or more of particles having a particle size in the range of 149 to 2000 μm, and having a bulk density of 0.4 g / ml or more.