JPH082967B2 - Granulation method of water-soluble cellulose derivative - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for granulating a water-soluble cellulose derivative.

[0002]

2. Description of the Related Art Conventionally, water-soluble cellulose derivatives have been known to have thickening properties, dispersibility, adhesive properties, emulsion stability, protective colloid properties,
Since it has characteristics such as film-forming property, it is used in a wide range of fields such as food industry, cosmetics, pharmaceutical industry, textile industry and paper industry. Generally, water-soluble cellulose derivatives are
When this is dissolved in water, since the particles of the water-soluble cellulose derivative to be put into water are apparently lumpy, the particles in the surface layer in contact with water are instantly dissolved and swollen, and surrounded by these particles. The penetration of water into the inner particles is significantly hindered (called mamako). Therefore, there is a problem that it takes time to completely remove and dissolve the momoko.

[0003] On the other hand, various methods have been proposed in the past for preventing mamako of a water-soluble cellulose derivative and accelerating the dissolution rate, and particularly good results have been obtained by granulating the water-soluble cellulose derivative. The method is shown in Japanese Patent Publication No. 2-50937. That is, the water content of the powdery water-soluble cellulose derivative is adjusted to 0.5 times or less of the equilibrium water content (temperature 25 ° C., relative humidity 70%), and the bulk specific gravity of the powdery water-soluble cellulose derivative is 500 to 900 g / L.
Is adjusted, and the mixture is passed between two rolls that rotate in mutually opposite directions to form flakes, which are then crushed and classified. However, even with this method, the yield of the granular water-soluble cellulose derivative was not sufficient, and further improvement was desired.

Therefore, the inventors of the present invention have conducted extensive studies in order to solve the above-mentioned drawbacks, and as a result, the powdery water-soluble cellulose derivative was made into a sheet-like form by passing it between two rolls rotating each other. The inventors have found that good results can be obtained by gradually adjusting the morphology of a cellulose derivative with a sizing machine, and have arrived at the present invention. Therefore, an object of the present invention is to provide a method for granulating a water-soluble cellulose derivative having a high yield.

[0005]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
It was achieved by gradually adjusting the morphology of the sheet-shaped water-soluble cellulose derivative in a sheet form by passing the powder-shaped water-soluble cellulose derivative between two rolls rotating with each other. That is, the powdery water-soluble cellulose derivative is introduced into a feeding device having two rollers, which are provided with a horizontal screw in the hopper and a lower portion of the hopper and rotate in mutually opposite directions, and are passed between the two rollers to form a sheet. In the method for granulating a water-soluble cellulose derivative, the powdered water-soluble cellulose derivative is passed through a roll between two rolls to form a sheet. Pass through a granulator and adjust the coarser than 20 mesh to the range of 10-40% by weight, then 2
It is obtained by passing through a subsequent sizing machine and then classifying. The water-soluble cellulose derivative used in the present invention,
Although not particularly limited, for example, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HE
C), methyl cellulose (MC), etc., or a mixture thereof.

In the present invention, the powdery water-soluble cellulose derivative is passed between two rolls rotating in mutually opposite directions to form a sheet, which is passed through a primary particle sizer to obtain a sheet having a coarser mesh than 20 mesh. The reason for adjusting to a range of ˜40% by weight is that when the content of the water-soluble cellulose derivative coarser than 20 mesh is less than 10% by weight, the granulated water-soluble cellulose derivative obtained after passing through a secondary sizing machine is obtained. The proportion of powdered (called powder reversion) in the powder increases, and the yield decreases. On the other hand, if it exceeds 40% by weight, the proportion of unsized particles having a large morphology in the obtained granulated water-soluble cellulose derivative after passing through the secondary particle sizer is increased, which is not preferable.

The reason why the crushing type roll sizing machine is used as the secondary sizing machine is that the appropriately sized water-soluble cellulose derivative can be sized in a desired form with good yield. In addition, the roll interval of the roll sizing machine is 0.2 to 0.7.
If the thickness is less than 0.2 mm, the ratio of the amount of powder returned in the obtained granulated water-soluble cellulose derivative after passing through a roll sizing machine is large, and the yield is reduced. on the other hand,
If it is larger than 0.7 mm, the proportion of unsized particles having a large morphology in the obtained granulated water-soluble cellulose derivative after passing through a roll sizing machine is increased, and the yield is reduced, which is not preferable.

The water-soluble cellulose derivative, which has been sized by a primary sieving machine, is classified into a desired form, which is used as a product.
There is no problem in passing only the coarse morphology other than the intended one through the secondary sizing machine. The primary sizing machine used in the present invention is not particularly limited, and a widely and commonly used sizing machine is appropriately selected and used. According to the manufacturing method of the present invention, 1
In the secondary sieving machine, a certain proportion of the water-soluble cellulose derivative containing a coarse morphology is used, so that the proportion of the powder returned by the primary sizing is small. In the secondary sizing machine, the coarse water-soluble cellulose derivative is mainly sized by adjusting the roll interval, so that the proportion of the powder returned by the secondary sizing is small.
In any case, the yield is improved. According to the granulation method of the present invention, it is necessary to install a secondary sizing machine. However, even if it is installed, the effect is great and it is extremely useful.

[0009]

The present invention will be described in more detail below, but the present invention is not limited thereto.

Example 1 Powdered CMC (DS = 0.61M / C ₆ ) was passed through a roller compactor (manufactured by Turbo Kogyo Co., Ltd.) to form a sheet, which was crushed by a rough breaker, and then a rotary blade type equipped with a screen. It was passed through a turbo granulator (manufactured by Turbo Kogyo Co., Ltd.), and while adjusting the number of revolutions, CMC having a coarser form than 20 mesh was 32% by weight. Next, after passing the CMC through a roll granulator (manufactured by Nippon Granulator Co., Ltd.) of a crushing system with a roll interval of 0.4 mm, it was sieved with a classifier and passed through 24 mesh and without passing through 80 mesh. A granulated CMC was obtained.
The yield was 61%.

Comparative Example 1 A CMC that is exactly the same as that of Example 1 is crushed into sheets by the same apparatus and procedure as those of Example 1 and is passed through a turbo granulator to adjust the number of revolutions of the CMC to obtain a coarser form than 20 mesh. A CMC containing 6% by weight of CMC was obtained. Next, the above CMC was passed through a roll granulator having the same roll interval as in Example 1 with a roll interval of 0.4 mm, and then sieved with a classifier to obtain granulated CMC which passed through 24 mesh and did not pass through 80 mesh. Obtained. The yield was 42%.

Comparative Example 2 A CMC which is exactly the same as that of Example 1 and which is crushed into sheets by the same apparatus and procedure as those of Example 1 is passed through a turbo granulator and the rotation speed is adjusted to obtain a coarser form than 20 mesh. A CMC having a content of 51% by weight was obtained. Next, the above CMC was passed through a roll granulator having the same roll interval as in Example 1 with a roll interval of 0.4 mm, and then sieved with a classifier to obtain granulated CMC which passed through 24 mesh and did not pass through 80 mesh. Obtained. The yield was 40%.

COMPARATIVE EXAMPLE 3 The same CMC as in Example 1 was cut into sheets by the same apparatus and procedure as in Example 1 and crushed, and then passed through a turbo granulator to adjust the number of revolutions thereof to obtain a coarser form than 20 mesh. A CMC having a content of 30% by weight was obtained. Next, the above CMC was passed through a roll granulator having the same roll gap as in Example 1 with a roll interval of 0.1 mm, and then sieved with a classifier to obtain granulated CMC that passed through 24 mesh and did not pass through 80 mesh. Obtained. The yield was 11%.

COMPARATIVE EXAMPLE 4 The same CMC as in Example 1 was cut into sheets by the same apparatus and procedure as in Example 1 and crushed, and then passed through a turbo granulator to adjust the number of revolutions thereof, and a coarser form than 20 mesh. A CMC having a content of 32% by weight was obtained. Then, the above CMC was passed through a roll granulator having the same roll gap as in Example 1 with a roll interval of 0.8 mm, and then sieved with a classifier to obtain granulated CMC that passed through 24 mesh and did not pass through 80 mesh. Obtained. The yield was 48%.

The yields of the granulated CMCs obtained in Example 1 and Comparative Examples 1 to 4 are summarized in Table 1. From the results of the above Examples and Comparative Examples, the yield of the granulated product (the ratio of those that passed 24 mesh and did not pass 80 mesh) was 1 as in the case of the present invention, not just using two granulators. It has been proved that the particle size can be greatly improved by limiting the particle size after passing through the secondary granulator and specifying the secondary granulator and its operating conditions.

[0016]

[Table 1]

[0017]

As described above in detail, according to the production method of the present invention, a water-soluble cellulose derivative is made into a moderately coarse form by a primary sieving machine, and a secondary sieving machine mainly makes a coarse form. Since the particles are sized, the proportion of the amount of powder returned in the sizing step is reduced, and the yield of granulated products is improved.

Continuation of the front page (56) Reference JP-A-2-169629 (JP, A) JP-B 60-17336 (JP, B2) JP-B 2-50937 (JP, B2) JP-B 38-8577 (JP , B1) Japanese Patent Publication No. 4-3413 (JP, B2) Japanese Patent Publication No. 54-7313 (JP, B2)

Claims (3)

[Claims] 1. A powdery water-soluble cellulose derivative is introduced as a feeding device to a feeding device having a hopper and a horizontal shaft screw at the lower part of the hopper and having two rolls rotating in mutually opposite directions, and between the two rolls. In a granulation method of a water-soluble cellulose derivative, the sheet-shaped cellulose derivative is passed through a primary particle sizer to obtain a sheet having a coarser shape than 20 mesh. 10 to 40% by weight, then 2
A method for granulating a water-soluble cellulose derivative, characterized in that it is obtained by passing through a subsequent granulator and then classifying. 2. The method for granulating a water-soluble cellulose derivative according to claim 1, wherein the secondary granulator is a crushing type roll granulator. 3. The roll gap of the roll sizing machine is 0.2 to
The method for granulating a water-soluble cellulose derivative according to claim 2, wherein the granule size is in the range of 0.7 mm.