JPH11315473A - Production of disaggregated modified cellulose-based filament - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject filaments by disaggregating modified cellulose filament bundles while maintaining the filament length. SOLUTION: The disaggregated modified cellulose-based filaments are obtained by the following procedure: modified cellulose-based filament bundles are immersed in water or its mixture with a specified hydrophilic solvent to disaggregate the bundles followed by bundling the disaggregated filaments again; the resulting bundle is immersed in the hydrophilic solvent and agitated for a specified time, and then pulled up to remove an excess of the hydrophilic solvent into a dehydrated bundle, which, in turn, is subjected to a disaggregating machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of immersing a bundle of chemically modified pulp or cellulose fiber or other modified cellulosic monofilaments in a hydrophilic solvent, dewatering the dehydrated bundle, and modifying the bundle. The present invention relates to a method for obtaining a cellulosic single fiber.

[0002]

2. Description of the Related Art Pulp and cellulose fibers are chemically modified by various chemical modification methods depending on purposes. In this chemical modification reaction, water is used for a solvent or for washing after the reaction. For this reason, water enters between the chemically modified cellulose molecules. Generally, cellulose molecules are hydrophilic and chemically modified cellulose molecules-
Hydration occurs between water and the binding between cellulose molecules increases. For this reason, the obtained modified cellulosic single fibers tend to be fiber bundles bound together.

[0003] Generally, as a method of defibrating the bundled fibers, a method in which a hammer is rotated at a high speed in a crushing chamber to defibrate an object to be defibrated by impact and friction, or an object to be defibrated in water. And a method in which the object to be defibrated is hooked by a roll around which a metallic wire is wound or a roll in which a large number of saw teeth are embedded, and the like.

[0004]

However, the above-mentioned bundle of modified cellulose-based fiber bundles has a strong bonding force between fibers, so that it is difficult to defibrate by the above-mentioned method. Further, even if the fibers were forcibly defibrated, the modified cellulosic single fibers were cut, and it was difficult to obtain a defibrated material in which the fiber length before defibration was maintained as it was.

[0005] Therefore, an object of the present invention is to defibrate a fiber bundle in which modified cellulose single fibers are bound while maintaining the fiber length.

[0006]

Means for Solving the Problems In order to solve the above problems, a method for producing a defibrated modified cellulose-based single fiber according to the present invention comprises immersing a bundle of modified cellulose-based single fibers in a hydrophilic solvent. Then, the mixture is stirred for a predetermined time, pulled up to remove an excess hydrophilic solvent, and then applied to a defibrating machine.

At this time, as a bundle of the above-mentioned modified cellulosic monofilaments, the bound modified cellulosic fiber bundle is
It was immersed in a mixed solution of water or a hydrophilic solvent containing not more than 60% (v / v%) of a hydrophilic solvent and water and pulled up to remove excess water or a mixed solution of the aqueous hydrophilic solvent and water. Things are used.

When the above-mentioned pre-treated bundle is put in a hydrophilic solvent and stirred, water contained in the bundle is taken away by the hydrophilic solvent, and the water is replaced by the hydrophilic solvent. As a result, the amount of water in the bundle decreases, and the bonding force between the chemically modified cellulose molecules decreases. Therefore, the bundle is easily defibrated, and a modified cellulose-based single fiber can be obtained.

[0009]

Embodiments of the present invention will be described below. In the method for producing a defibrated modified cellulosic single fiber according to the present invention, first, a bundle of modified cellulosic fiber bundles (hereinafter referred to as a “bundled material”) is bound with water or 60.
% (V / v%) or less of a mixed solution of a hydrophilic solvent and water after stirring, and then pulled up to remove excess water or a mixed solution of the hydrophilic solvent and water to remove the modified cellulose-based single fiber. A converged body (hereinafter, referred to as a "converged body") is obtained. Next, the bundle is immersed in a hydrophilic solvent and stirred for a predetermined time, and is lifted to remove an excess of the hydrophilic solvent.
This is referred to as a “dehydrated bundle”. ), And then apply this to a defibrating machine.

The above-mentioned modified cellulosic monofilament is a chemically modified pulp or a cellulose fiber or the like, and refers to a pulp or a cellulose fiber which is defibrated for each single fiber. The chemical modification is performed for the purpose of modifying the properties of cellulose. Examples of the chemical modification include methylation, hydroxyethylation, carboxymethylation, sulfonation, sulfoalkylation, phosphorylation, phosphorylation, Aminodeoxylation, chlorodeoxylation and the like. Examples of such modified cellulosic monofilaments include carboxymethylated pulp,
Examples thereof include carboxymethyl cellulose (hereinafter abbreviated as “CMC”) fiber, sulfomethyl cellulose fiber, sulfoethyl cellulose fiber, cellulose sulfate fiber and the like.

The above-mentioned methylation reaction is carried out by reacting alkali cellulose with methyl chloride or dimethyl sulfate. The above hydroxyethylation reaction is performed by reacting cellulose oxide with ethylene oxide. Carboxymethylation is carried out by reacting cellulose with sodium hydroxide and monochloroacetic acid. The above sulfonation is performed by reacting cellulose with chlorosulfonic acid. The phosphorylation or phosphorylation is performed by reacting cellulose with phosphoric acid and urea. The above sulfoethylation is carried out by reacting cellulose with vinylsulfonic acid or bromoethylsulfonic acid. Each of the above reactions is
Water is used for removing the reactant for a solvent or for washing after the reaction. For this reason, the obtained modified cellulosic fibers are hydrated with each other by water, and become the above-mentioned bound material in which the fibers are bound. In this bundle, the bond between the fibers is strong, and it is difficult to disintegrate the fibers individually.

[0012] Therefore, the bound material is treated with water or 60%
(V / v%) After being immersed in a mixed solution of a hydrophilic solvent and water containing the hydrophilic solvent of not more than (v / v%) with stirring, it is pulled up to remove excess water or the mixed solution. Thereby, the above-mentioned convergence body can be obtained. With this operation, the binding of the binding object can be released.

In this case, a mixture of a hydrophilic solvent containing more than 60% (v / v%) of a hydrophilic solvent and water is inferior in disintegration of the modified cellulose fiber.
%) It is better to use a mixture of a hydrophilic solvent containing the following hydrophilic solvent and water. Further, a mixed solution containing 0% of the hydrophilic solvent, that is, water can also be used.

Examples of the hydrophilic solvent include alcohols such as methanol, ethanol, 1-butanol, 2-butanol, isobutyl alcohol, t-butyl alcohol, and propanol; ethers such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; Ketones such as acetone and methyl ethyl ketone, amides such as dimethylformamide and dimertyl acetamide, dimethyl sulfoxide, acetonitrile and the like are used.

Next, when the above bundle is dehydrated by applying a hydrophilic solvent to the bundle, the bundle becomes the dehydrated bundle and is easily loosened. As the hydrophilic solvent, those similar to the hydrophilic solvents used for releasing the binding of the binding material can be used. Among these, a hydrophilic solvent having strong water affinity and having a dehydrating property from the bundle is preferable.

The case where methanol is specifically used as the hydrophilic solvent used for releasing the binding and dehydrating the bundle will be described below. First, the above-mentioned bundle is immersed in a methanol-water mixture containing 60% (v / v%) or less of methanol under stirring, and then the mixture is removed to obtain a bundle. Next, the bundle is immersed in methanol and stirred for a predetermined time. At this time,
Since methanol has a strong dehydration ability, it deprives the condensed body of water contributing to hydration, and the water is exchanged with methanol. As a result, a dehydrated bundle is obtained. The concentration of methanol used at this time may be dehydrating methanol, that is, methanol having a concentration of 70% or more, and it is not always necessary to use 100% methanol that has been completely dehydrated.

The stirring time is not particularly limited as long as the bundle is dehydrated to such an extent that the bundle is easily loosened.

The dehydrated bundle is lifted, left, and dried to remove excess methanol. The dehydrated bundle thus obtained is easily loosened and can be defibrated by any defibrating device. In particular, the use of the defibrating device shown below allows the dehydrated bundle to be defibrated for each single fiber, and the modified cellulose-based single fiber is hardly cut, and the fiber length is preferably preserved. .

The fibers to be defibrated by the defibration apparatus according to the present invention include a large number of chemically modified pulp such as carboxymethylated pulp and CMC, cellulose fibers and the like (hereinafter collectively referred to as "cellulosic fibers"). It is a fiber bundle gathered and bound. The above CMC may be in an acid form or a salt form. An example of the salt type is CM which is a sodium salt.
C sodium salt (hereinafter abbreviated as “CMC (Na)”), sodium salt and silver salt of CMC sodium / silver salt (hereinafter abbreviated as “CMC (Na · Ag)”), sodium salt, CMC sodium / silver / copper salt (hereinafter referred to as “CMC (Na · Ag · C
u) ". ), Sodium, silver and zinc salts of sodium, silver and zinc (hereinafter referred to as “CMC”).
(Na.Ag.Zn) ". ), Sodium salt,
CMC sodium / silver / copper / zinc salts which are silver salts, copper salts and zinc salts (hereinafter referred to as “CMC (Na · Ag · Cu · Z)”
n) ". ), Sodium salts, silver salts and calcium salts of CMC sodium / silver / calcium salts (hereinafter abbreviated as “CMC (Na · Ag · Ca)”).

The above chemically modified cellulosic fiber bundle usually contains a small amount of water, increases the inter-fiber bonding force, and forms a bundle. For this reason, it is preferable to supply the dehydrated bundle obtained by performing the above-described pre-treatment on the bundle to the defibrating device according to the present invention.

Such a defibrating device is not particularly limited, but is preferably a defibrating device comprising a combination of a defibrillator 1 and a dust collector 2, as shown in FIGS.

The defibrating machine 1 comprises a casing 11 and a rotating blade 1 provided on the inner bottom surface of the casing 11.
2 and a driving device 13 for the rotating blades 12. The casing 11 has a bowl-like shape in which an upper surface is opened and a peripheral wall near a bottom surface of a cylinder whose lower surface is closed is curved at a predetermined curvature. The rotating blade 12 is connected to a driving device 13 by a rotating shaft 14, and the rotating blade 12 is rotated by the driving device 13. The rotational speed is not particularly limited, but a low rotational speed of 450 to 1000 rpm can sufficiently achieve the purpose. In addition, the rotating blade 12
Is not limited to four as shown in FIG. 2, but an arbitrary number can be adopted. Furthermore, the above-mentioned rotating blade 1
The shape of 2 is not limited to the cross shape as shown in FIG. 2, and any shape can be adopted according to the number of rotating blades 12.

The dust collector 2 includes a dust collector 21 for covering the open surface of the casing 11 and a charging cylinder 2 for charging the raw material.
2, and a suction device 23 for sucking the inside of the dust collecting section 21. The dust collecting part 21 is communicated with a suction port 26 provided in contact with the inner peripheral wall of the casing 11.

That is, as shown in FIG. 1, the dust collecting section 21 includes a conical upper member 31 and a conical lower member 32. The upper member 31 covers the upper surface of the lower member 32. Provided. Thereby, the defibrating chamber 15 is formed in the space between the dust collecting portion 21 and the inner bottom of the casing 11 inside the casing 11.

As shown in FIGS. 1 and 2, the dust collecting portion support piece 16 is located at the same height on the inner peripheral wall of the casing 11.
Are provided in a predetermined number. As shown in FIG. 3, the dust collecting portion support piece 16 is made of a material having elasticity and is formed in a triangular prism shape. The outer peripheral edge of the lower member 32 is pressed against one ridge line portion of the dust collecting portion support piece 16 and is supported by friction. As a result, the dust collecting portion 21 is attached to the casing 11 and the suction port 26 is provided between the peripheral wall surface of the casing 11 and the outer peripheral edge of the lower member 32 by a width corresponding to the height of the dust collecting portion supporting piece 16. Is formed. The diameter of the suction port 26, that is, the height of the dust collecting portion supporting piece 16 is
There is no particular limitation, as long as the defibrated fibers can move. For example, it may be about 0.01 to 5 mm. Note that the shape of the dust collecting portion support piece 16 is not limited to a triangular prism shape as long as the lower member 32 can be held.

Further, as shown in FIG. 1, an upper member 31 communicates with the suction port 26 and the dust collecting chamber 25.
And the conical surface of the lower member 32. Thereby, the defibration chamber 15 inside the casing 11 is
6, communicates with the dust collection chamber 25 through the communication passage 24.

Since the upper member 31 and the lower member 32 have a conical shape opened downward, the communication path 24
Tilt upward from the suction port 26 to the dust collection chamber 25. The upper member 31 includes a portion that forms the communication passage 24 and a portion that forms the dust collection chamber 25, and both are connected by a spring 33. For this reason, when it is difficult for the suction device 23 to suck in the communication path 24, the width of the communication path 24 is increased or reduced by expanding and contracting the spring 33, and the communication path 24 tends to stay in the communication path 24. The stay of the defibrated fibers can be prevented.

The dust collecting chamber 25 is provided near the top between the upper member 31 and the lower member 32. In this way, the communication path 24 can be formed over the entire conical surfaces of the upper member 31 and the lower member 32, and the defibrated fibers can be collected at the most efficient position.

The charging cylinder 22 is provided so as to penetrate the dust collecting chamber 25. The leading end of the charging cylinder 22 is provided to penetrate the bottom plate 35 of the lower member 32, and the dewatering convergence body is charged into the charging cylinder 22 to directly rotate the defibrating chamber 15 while rotating the rotary blades 12. Can be put inside. If provided at this position, the dehydrated bundle to be defibrated can be thrown into the vicinity of the central rotating shaft 14 in the defibration chamber 15, and the defibration can be performed uniformly.

An annular ridge 17 is provided below the suction port 26, that is, on the inner peripheral wall of the casing 11 below the dust collecting portion support piece 16. Also, a protruding piece 18 is provided on the inner peripheral wall of the defibrating chamber 15.
Are provided in a predetermined number. In particular, it is preferable that the annular ridge 17 be provided immediately below the suction port 26.

Since the flow of air from the defibrating chamber 15 to the suction port 26 is disturbed by the ridges 17 and the protruding pieces 18, the falling of the dehydrated bundle which is insufficiently defibrated is promoted. Further, since the diameter of the suction port 26 is further narrowed by the ridges 17, it is possible to prevent the dehydrated bundle that has not been completely defibrated from being sucked into the dust collection chamber 25. Further, the protruding pieces 18 increase the efficiency of dispersing the dehydrated bundle into single fibers as in a baffle plate.

The suction machine 23 is provided with a collection bag (not shown), and all the sucked air passes through the collection bag, so that the fibers contained in the air are collected in the collection bag.

Next, the operation of the defibrating device according to the present invention will be described.

First, the rotary blades 12 are rotated, and the suction device 2
Activate 3 The rotation of the rotating blades 12 causes the defibration chamber 1 to rotate.
The air in 5 becomes spiral. Since the casing 11 is bowl-shaped, the air in the defibrating chamber 15 is rotated by the rotating blades 12 and rises spirally along the peripheral wall of the defibrating chamber 15 toward the suction port 26. Further, the air flows from the defibrating chamber 15 to the suction machine 23 through the suction port 26, the communication path 24, the dust collection chamber 25, and the hose 28 by the suction machine 23.

In this state, the dehydrated bundle to be defibrated is charged from the charging cylinder 22. The fed dehydrated bundle is taken up by the suction port 26 along the flow of air while being defibrated by the rotating blades 12.
Head for. The dehydrated bundle that has not been sufficiently defibrated falls due to its own weight and is defibrated again by the rotating blades.

Further, since the flow of the air is disturbed by the ridges 17 and the projections 18, the falling of the dehydrated bundle which is insufficiently defibrated is promoted.

The fibers reaching the suction port 26 are collected in the dust collection chamber 25 through the communication path 24. This dust collection room 2
5 is connected to a hose 28 connected to the suction machine 23, and the fibers are collected in the collection bag (not shown) of the suction machine 23 through the hose 28.

When the upper member 31 is divided into a portion forming the communication passage 24 and a portion forming the dust collection chamber 25 and both are connected by a spring 33, the communication passage 24 is formed by elastically moving the spring 33. The constituent parts move up and down a little.
Accordingly, the width of the communication path 24 is slightly increased or decreased, so that when the communication path 24 is clogged with the fiber, it can be used to clear the clogging.

Further, if the lid 34 is provided on the upper part of the casing 11, it is possible to prevent the dust or the like from being sucked in from outside during dust collection.

[0040]

EXAMPLES The above-mentioned invention will be specifically described with reference to examples.

Example 1 Fibrillation of CMC (Na.Ag) / in the case of methanol 42.550 g of CMC (Na) fibers (moisture: 88.32%, solid: 4.970 g, DS: =
0.42, Kikkolate LD-A, manufactured by Nichirin Chemical Industry Co., Ltd.). This was suspended in 500 ml of 30% aqueous methanol, 28.2 mg of silver nitrate was added, and the mixture was shaken for 48 hours. After completion of the reaction, the mixture was separated by a centrifuge, washed with 30% aqueous methanol, and centrifuged to produce a bundle of CMC (Na.Ag) fibers.

Next, put pure methanol into a mixer,
The above bundle of CMC (Na.Ag) fibers was added little by little under strong stirring. After stirring for a while, the contents were taken out and the methanol was removed by filtration or centrifugation. This operation was repeated twice to obtain a dehydrated bundle.
The yield was 5.10 g (water content: 7.85%), silver content: 0.35% (as absolutely dry), 0.32% (as water-containing).

The CMC (Na.A) before and after the treatment
g) The weight average fiber length of each fiber was 2.36 mm.

Operating conditions of the defibrating device The devices shown in FIGS. 1 to 3 were used as the defibrating device.
The rotating blades 12 used four cross-shaped blades and were rotated at 690 rpm. The suction force of the suction device 23 may be any minimum suction force that can efficiently collect the defibrated fibers in the collection bag. 28 g of each of the above dehydrated bundles was used, and 10 g
Driving for minutes.

The defibrated results defibrated the CMC (Na · Ag) single fiber, 20.0 g
Was recovered (recovery rate: 71.5%).

The weight average fiber length of the obtained CMC (Na.Ag) fiber was 2.34 mm. Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

Similar results were obtained when the above 30% methanol water was replaced with water or methanol water having a concentration of 60% or less.

Example 2 CMC (Na.Ag) fibrillation / in the case of methanol CMC (Na.Ag) fiber was reacted under the conditions of Example 1, centrifuged, washed with water only, and centrifuged. And CMC
A bundle of (Na.Ag) fiber was produced. Next, 3 L of pure methanol was put into a mixer, and 273.7 g (water content: 94.7%) of the above bundle of CMC (Na.Ag) fibers was added little by little under strong stirring. After stirring for a while, the contents were taken out and the methanol was removed by filtration or centrifugation. This operation was repeated twice to obtain a dehydrated bundle. The yield was 12.96 g. This dehydrated bundle was defibrated using the above-described defibration apparatus under the same defibration conditions as in Example 1 described above to obtain a good cotton-like defibrated material.

Comparative Example 1 CMC (N
a) 30% methanol water was added to the fibers to disintegrate them, and then a bundle was obtained by centrifugation. After the obtained bundle was air-dried, the bundle was defibrated using the above defibration apparatus under the same defibration conditions as in Example 1 above.

As a result, no defibrated material was obtained. This is because the bundle was not dehydrated by the pure methanol washing treatment, and it is considered that fibrillation was impossible due to strong binding between the fibers due to air drying.

Comparative Example 2 CMC (N
a) Fiber (DS = 0.42, moisture content: 75.2%, Kikkolate LD-A, manufactured by Nichirin Chemical Industries) was used. 4.0 g of the bundle was put into pure methanol in a mixer and stirred to obtain a dehydrated bundle. This dehydrated bundle was defibrated using the above defibration device under the same defibration conditions as in Example 1 above.

As a result, no defibrated material was obtained. This is because a immersed body was previously immersed in a mixture of a hydrophilic solvent containing 60% (v / v%) or less of a hydrophilic solvent and water (such as 30% methanol), and the solvent was not removed. .
In addition, since pure methanol prioritized the moisture content of the above-mentioned bundles rather than loosening the interfiber bonds, the fibrillation became impossible.

Example 3 Fibrillation of CMC (Na.Ag) / in the case of acetone C which is a bundle obtained by the method described in Example 1
51.86 g of MC (Na.Ag) fiber (30% methanol-washed bundle, water content: 94.3%) was placed in a mixer.
The mixture was stirred with 300 ml of acetone, and the residue obtained by centrifugation was again stirred with 300 ml of acetone, centrifuged, and dried under vacuum to obtain a dehydrated bundle of CMC (Na.Ag) fibers.

The dehydrated bundle was defibrated under the same defibration conditions as in Example 1 to obtain 2.97 g of defibrated material.

Fibrillation Result There was almost no difference in the weight average fiber length of the CMC (Na.Ag) single fiber before and after the fibrillation. Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

[Example 4] Fibrillation of CMC (Na.Ag) / in the case of acetonitrile C as a bundle obtained by the method described in Example 1
50.34 g of MC (Na.Ag) fiber (30% methanol-washed bundle, water content: 94.3%) was placed in a mixer.
The mixture was stirred with 300 ml of acetonitrile, and the residue obtained by centrifugation was again stirred with 300 ml of acetonitrile, centrifuged, and dried under vacuum to obtain CMC (Na · A).
g) A dehydrated bundle of fibers was obtained.

This dehydrated bundle was defibrated using the above defibration apparatus under the same defibration conditions as in Example 1 to obtain 2.98 g of a defibrated material.

There was almost no difference in the weight average fiber length of the CMC (Na.Ag) single fiber before and after defibration . Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

Example 5 Fibrillation of CMC (Na.Ag) / in the case of isopropyl alcohol C which is a bundle obtained by the method described in Example 1
35.84 g of MC (Na.Ag) fiber (30% methanol washed bundle, water content: 94.3%) was placed in a mixer.
The mixture was stirred with 210 ml of isopropyl alcohol, and the residue obtained by centrifugation was again subjected to 210 ml of isopropyl alcohol.
and centrifugation, followed by vacuum drying to obtain C.
A dehydrated bundle of MC (Na.Ag) fibers was obtained.

This dehydrated bundle was defibrated under the same defibration conditions as in Example 1 to obtain 2.08 g of a defibrated material.

There was almost no difference in the weight average fiber length of the CMC (Na.Ag) single fiber before and after defibration . Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

Example 6 Fibrillation of CMC (Na.Ag) / in the case of tetrahydrofuran C which is a bundle obtained by the method described in Example 1
35.82 g of MC (Na.Ag) fiber (30% methanol washed bundle, water content: 94.3%) was mixed in a mixer.
The mixture was stirred with 210 ml of tetrahydrofuran, and the residue obtained by centrifugation was again stirred with 210 ml of tetrahydrofuran, centrifuged, and dried under vacuum to obtain CMC (N
a ・ Ag) A dehydrated bundle of fibers was obtained.

The bundle was defibrated using the above defibration device under the same defibration conditions as in Example 1, and
0 g was obtained.

Fibrillation Results There was almost no difference in the weight average fiber length of CMC (Na.Ag) single fibers before and after defibration . Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

[Example 7] Fibrillation of CMC (Na.Ag) / in the case of dimethylformamide C which is a bundle obtained by the method described in Example 1
35.62 g of MC (Na.Ag) fiber (30% methanol-washed bundle, water content: 94.3%) was mixed in a mixer.
The mixture was stirred with 210 ml of dimethylformamide, and the residue obtained by centrifugation was again stirred with 210 ml of dimethylformamide, centrifuged, and dried under vacuum to obtain CMC.
A dehydrated bundle of (Na.Ag) fibers was obtained.

This dehydrated bundle was defibrated using the above defibration apparatus under the same defibration conditions as in Example 1 to obtain 2.10 g of a defibrated material.

Fibrillation Results There was almost no difference in the weight average fiber length of CMC (Na.Ag) single fibers before and after fibrillation. Moreover, the defibrated CMC (Na.Ag) single fiber was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by cutting the fiber.

Example 8 Sulfoethylcellulose
Disintegration of sodium / silver salt / in the case of methanol (Synthesis of fibrous sulfoethylcellulose / sodium salt) In a small kneader (3 L), 20.55 g of cellulose pulp (moisture ratio: 2.69%) is charged little by little, and water is added. A mixture of an aqueous solution of sodium oxide (13.72 g / 37.2 ml) and 202 ml of isopropyl alcohol is dropped with a pipette, and the whole is moistened. Approximately 30 after addition
Mix for a minute. Next, 64.3 g of sodium vinyl sulfonate (25% aqueous solution) was added dropwise, and the mixture was further mixed for 30 minutes. Thereafter, the mixture was heated to 70 ° C. for 3 hours, and then mixed at room temperature for one day and night. The residue was taken out from the kneader, transferred into a mixer, and washed with 70-80% methanol water (500 ml × 6 times) to make the liquid neutral, followed by pure methanol washing. Then, a white fibrous bundle (Na salt) was obtained. The yield was 17.5 g (moisture content:
(1.44%), the exchange capacity was 0.42 meq / g (measured as the acid type), and the DS was 0.070.

(Synthesis of fibrous sulfoethylcellulose sodium silver salt) The above-mentioned tied substance (fibrous sulfoethylcellulose sodium salt) 6.616 was dissolved in a solution of 33.4 mg of silver nitrate in 600 ml of 30% methanol.
1 g (water content: 1.44%, anhydrous 6.5208 g) was suspended and shaken for 29 hours. Thereafter, the bundle was washed with 30% aqueous methanol to obtain a bundle.

Next, washing with pure methanol was performed twice in a mixer, followed by vacuum drying to obtain a dehydrated aggregate (sodium / silver salt). The yield was 6.4611 g (water content:
2.00%), the silver content was 0.278% (as hydrate) and 0.284% (as anhydride).

Operating conditions of the defibrating device The defibrating device used in Example 1 was used to perform defibration under the operating conditions described in Example 1.

Fibrillation Results Fibrillated fibrous sulfoethylcellulose / sodium / silver salt was a good cotton without fibrillation unevenness, and almost no pulverized material was mixed by fiber cutting. The weight average fiber length was 1.756 mm before defibration, whereas it was 1.740 mm after defibration, which was almost unchanged.

[0073]

According to the present invention, the fibers can be defibrated into a floc without cutting the fibers. That is, the fiber length before defibration and the fiber length after defibration hardly change.

Further, since the dehydrated bundle is defibrated while maintaining the fiber length, when mixed into a nonwoven fabric or paper,
The fibers can be sufficiently entangled with the constituent fibers or pulp of the nonwoven fabric, and the fibers can be prevented from falling off from the nonwoven fabric or paper. At this time, when an antibacterial substance such as silver is carried on the fiber, an antibacterial effect can be imparted to the nonwoven fabric or paper, and the fiber can be maintained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a defibrating device according to the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a partially cutaway view showing a relationship among a casing, an upper member, a lower member, and a dust collecting portion support piece of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Defibrator 2 Dust collector 11 Casing 12 Rotating blade 13 Drive 14 Rotary shaft 15 Defibrating chamber 16 Dust collecting part support piece 17 Ridge 18 Protrusion piece 21 Dust collecting part 22 Input cylinder 23 Suction machine 24 Communication path 25 Dust collecting chamber 26 Suction port 28 Hose 31 Upper member 32 Lower member 33 Spring 34 Cover 35 Bottom plate

Claims (2)

[Claims] Claims 1. A bundle of modified cellulose-based single fibers is immersed in a hydrophilic solvent, stirred for a predetermined time, pulled up to remove excess hydrophilic solvent, and then subjected to a defibrating machine.
A method for producing a defibrated modified cellulose-based single fiber. 2. The above-mentioned bundle of modified cellulose-based single fibers comprises a bundle of modified cellulose-based fibers bundled with water or 60%
(V / v%) The liquid is immersed in a mixed solution of a hydrophilic solvent and water containing a hydrophilic solvent of not more than (v / v%) and pulled up to remove excess water or a mixed solution of the hydrophilic solvent and water. 2. A method for producing the defibrated modified cellulosic single fiber according to 1.