JP5234552B2 - Method for producing cellulose molded product - Google Patents

Description

The present invention relates to a method for producing a cellulose molded product, and more particularly to a method for producing a cellulose molded product with improved impact resistance .

  In Patent Document 1 below, a cellulose solution is supplied to a rotating container that rotates at a high speed, and a centrifugal force having a centrifugal acceleration of 10 to 1000 G is generated from a discharge hole having a diameter of 0.1 to 5.0 mm formed in the rotating container. A method for producing cellulose particles is proposed in which a cellulose solution is dispersed to form droplets, and the droplets are trapped in a coagulating liquid to be coagulated.

Japanese Patent No. 3177487

Since the cellulose particles obtained by the method for producing cellulose particles of Patent Document 1 are cellulose particles having a high sphericity and a small particle size distribution, blasting for deburring resin molded products and cleaning of resin molded dies It can be used as particles.
However, since cellulose particles as blast particles have poor impact resistance, the replacement frequency is high, and at present, they are not industrially used as blast particles.
Cellulose fibers such as rayon yarns are less likely to generate static electricity and are suitable for bag filters in a low temperature atmosphere.
However, even in the bag filter, since the impact is intermittently applied from the outside in order to remove the trapped substances accumulated inside, it is difficult to use the cellulose fiber having poor impact resistance for the bag filter.
Accordingly, an object of the present invention is to provide a method for producing a cellulose molded article having improved impact resistance comprising cellulose particles or cellulose fibers.

The present inventor has reached the present invention as a result of considering that it is effective to impregnate a cellulose component or cellulose monofilament with a rubber component in order to solve the above problems.
That is, in the method for producing a cellulose molded product according to the present invention, particles or single fibers, which are cellulose molded products made of cellulose, are immersed in a dispersion in which an uncrosslinked elastomer is dispersed, and the dispersion is used as the particles or single particles. A step of impregnating the fibers, a drying step of drying the particles or single fibers impregnated with the dispersion, and a step of immersing the dried particles or single fibers in a cross-linking agent solution mixed with a cross-linking agent; A step of impregnating the solution into the particles or single fibers, a drying step of drying the particles or single fibers impregnated with the crosslinking agent solution , and heating the dried particles or single fibers into the particles or single fibers. And a crosslinking step of crosslinking the impregnated uncrosslinked elastomer, and the rubber component which is the elastomer crosslinked by a crosslinking agent is mixed in the particles or the single fiber itself by 5% by weight or more. Characterized in that to obtain a cellulose molding that.
In the present invention relating to the method for producing a cellulose molded product, natural rubber or synthetic rubber uncrosslinked elastomer is used as an uncrosslinked elastomer, and a natural rubber or cellulose monofilament is used in the cellulose particles or cellulose single fibers by using a crosslinking agent. Synthetic rubber can be cross-linked and maintained as biodegradable cellulose particles or cellulose monofilaments.
In particular, by using an uncrosslinked elastomer having an average molecular weight of 7000 or less as the uncrosslinked elastomer, the uncrosslinked elastomer can be easily impregnated into the cellulose particles or cellulose single fibers.
The molecular weight of the uncrosslinked elastomer can be reduced by applying a mechanical shearing force to the uncrosslinked elastomer.

In addition, before the drying step of drying the particles or single fibers impregnated with the dispersion, a step of washing and removing the dispersion adhering to the surface of the particles or single fibers, and impregnating with a crosslinking agent solution Before the drying step of drying the particles or single fibers, a step of washing and removing the cross-linking agent solution adhering to the surface of the particles or single fibers may be performed.
In addition, the step of impregnating the dispersion liquid into the particles or single fibers can be performed under reduced pressure or under pressure.

According to the present invention, since the rubber component can be crosslinked in a net shape in the cellulose particles or cellulose single fibers, the impact resistance of the cellulose particles or cellulose single fibers can be improved.
As a result, cellulose particles can be used as blast particles for deburring of resin molded products and cleaning of resin molding dies, which could not be used conventionally, and cellulose fibers are used for industrial applications such as filters. be able to.

It is the schematic for demonstrating the measuring apparatus which measures the impact resistance of a cellulose particle. It is a microscope picture which shows the state of the cellulose particle after giving 20000 times the impact by the natural fall of the housing 14 with respect to the cellulose particle with which the recessed part 12 of the mortar body 10 was filled. It is the schematic for demonstrating the measuring apparatus for measuring the impact resistance of a thread | yarn.

The cellulose molded product used in the present invention is particles or single fibers made of cellulose (hereinafter sometimes referred to as cellulose particles or cellulose single fibers).
As such cellulose particles or cellulose monofilaments, alkaline cellulose solutions such as viscose (a solution of sodium cellulose xanthate in water or sodium hydroxide solution) or cellulose copper ammonia solution are obtained from inorganic acids such as sulfuric acid and hydrochloric acid. What was obtained by discharging into a coagulating liquid in a granular or fibrous form from a predetermined discharge port can be used. In particular, as the cellulose particles, the cellulose particles obtained by the production method described in Patent Document 1 described above have a uniform particle size and can be suitably used.
As the cellulose monofilament, commercially available regenerated cellulose fibers such as rayon fibers and vegetable cellulose fibers such as cotton can be used.

Such cellulose particles or cellulose single fibers are immersed in a dispersion in which uncrosslinked elastomer is dispersed, and the cellulose particles or cellulose single fibers are impregnated with the uncrosslinked elastomer.
The uncrosslinked elastomer may be either synthetic rubber or natural rubber. However, when an elastomer of natural rubber is used, all cellulose particles or cellulose monofilaments having improved impact resistance are used in nature. It is preferable that it can be made of a material existing in
A dispersion in which such an uncrosslinked elastomer is dispersed can be obtained by adding to a hydrocarbon solvent such as benzene and stirring. Moreover, water can also be used as a dispersion liquid.
In these dispersions, 2% by weight or more, preferably 4% by weight or more, particularly preferably 5% by weight or more of uncrosslinked elastomer is added. In particular, when water is used as the dispersion, the uncrosslinked elastomer is a fine and uniform uncrosslinked elastomer, for example, when the particle size distribution is measured, a normal distribution having a single peak is obtained. It is preferred to use an approximate uncrosslinked elastomer.
A cross-linking accelerator solution in which a cross-linking accelerator is dissolved can be added to the resulting dispersion of the uncrosslinked elastomer.
As the crosslinking accelerator, zinc oxide can be suitably used. This zinc oxide can be dissolved in a solvent composed of ammonium chloride, methanol, glycerin and isopropyl alcohol to obtain a crosslinking accelerator solution. An acceleration aid or an antistatic agent may be added to the crosslinking accelerator solution.
If the liquid phase becomes unstable during the addition of the crosslinking accelerator solution to the dispersion in which the uncrosslinked elastomer is dispersed, a small amount of fluorine-based surfactant or nonionic penetrant is used. It may be added.

While the cellulose particles or cellulose single fibers are immersed and stirred in the dispersion of the uncrosslinked elastomer thus obtained, 4% by weight or more of the uncrosslinked elastomer is preferably contained in the cellulose particles or cellulose single fibers. It is necessary to impregnate 5% by weight or more. When the impregnation amount of the uncrosslinked elastomer is less than 4% by weight, it is difficult to sufficiently improve the impact resistance of the cellulose particles or cellulose single fibers.
In order to make the impregnation amount of the uncrosslinked elastomer into the cellulose particles or cellulose monofilaments 4% by weight or more, it is preferable to use an uncrosslinked elastomer having an average molecular weight of 7000 or less, particularly 3000 or less. This is an uncrosslinked elastomer of synthetic rubber, using an elastomer having an average molecular weight of 15000 and an elastomer having an average molecular weight of 3000, and impregnating the uncrosslinked elastomer into cellulose particles or cellulose single fibers under the same conditions. When the cellulose particles or cellulose single fibers were impregnated, the elastomer having an average molecular weight of 15000 had an impregnation amount of 1 to 2% by weight, but the elastomer having an average molecular weight of 3000 had an impregnation amount of 5%. It is clear from the fact that it was possible to achieve the weight percentage or more.

Thus, in order to obtain a low molecular weight elastomer, a peptizer such as stearic acid may be added to an uncrosslinked elastomer, and a mechanical shearing force such as a beater by a mixer or the like is applied to the molecular chain. It is preferable to reduce the molecular weight by cutting. When applying a mechanical shearing force such as a beater to reduce the molecular weight of the elastomer, a relationship between the time during which the mechanical shearing force such as a beater is applied and the average molecular weight of the elastomer is obtained in advance. The average molecular weight of the elastomer is preferably adjusted according to the time during which mechanical shearing force such as beater is applied.
Cellulose particles or cellulose monofilaments are immersed in the resulting dispersion of uncrosslinked elastomer. In this case, the bath ratio of the cellulose particles or cellulose single fibers to the dispersion is preferably 5 or more from the viewpoint of the stability of the solution.
Further, the cellulose particles or cellulose monofilaments were formed with an open mesh-like network body through which the cellulose particles or cellulose monofilaments cannot pass, filled in the bag, immersed in the dispersion, and stirred to finish the immersion. In this case, cellulose particles or cellulose single fibers can be easily recovered.

Further, the dispersion in which the cellulose particles or cellulose single fibers are immersed is heated and heated, and then the operation of cooling to a predetermined temperature is repeated a plurality of times to sufficiently infiltrate the dispersion into the cellulose particles or cellulose single fibers. be able to. The heating temperature is preferably about 60 ° C., and the cooling temperature is preferably about 15 ° C.
The impregnation treatment may be performed under atmospheric pressure, but the impregnation time can be shortened by performing the impregnation treatment under reduced pressure or under pressure as compared with the case where the impregnation treatment is performed under atmospheric pressure.
The cellulose particles or cellulose monofilaments that have been impregnated with the dispersion are taken out of the dispersion and subjected to a washing treatment for washing and removing the dispersion adhering to the surface. This is to prevent blocking of cellulose particles or cellulose single fibers.
In such washing treatment, when a hydrocarbon solvent such as benzene is used as the dispersion, the cellulose particles are mixed in a mixture of a hydrocarbon solvent such as benzene and an alcohol such as isopropyl alcohol so that the bath ratio is 10 or more. Alternatively, after washing by adding cellulose single fibers, cellulose particles or cellulose single fibers are added to the detergent mixture of nonionic detergent and weakly basic detergent so that the bath ratio is 10 or more and washing is performed.
Further, the cellulose particles or cellulose single fibers washed with water so as not to leave the detergent mixture on the cellulose particles or cellulose single fibers are subjected to centrifugal dehydration and then dried.
When water is used as the dispersion, the cellulose particles or cellulose single fibers separated from the dispersion can be washed with water, and then subjected to centrifugal dehydration and then dried.

In this way, the cellulose particles or cellulose single fibers impregnated with the uncrosslinked elastomer are impregnated with a crosslinking agent as necessary in order to promote the crosslinking reaction of the uncrosslinked elastomer. Such a crosslinking agent is impregnated into cellulose particles or cellulose single fibers by immersing cellulose particles or cellulose single fibers impregnated with an uncrosslinked elastomer in a crosslinking agent solution obtained by dissolving in a solvent. Can do.
Here, when an uncrosslinked elastomer of natural rubber is impregnated into cellulose particles or cellulose single fibers, sulfur can be used as a crosslinking agent. Impregnation of cellulose particles or cellulose single fibers with sulfur can be performed by immersing cellulose particles or cellulose single fibers impregnated with an elastomer of natural rubber in a solution of powdered sulfur dissolved in carbon disulfide. .
Next, the cellulose particles or cellulose single fibers that have been subjected to the sulfur impregnation treatment are taken out of the solution, washed with water and dried.
Thereafter, the uncrosslinked elastomer impregnated in the cellulose particles or cellulose single fibers can be crosslinked by heat treatment at a predetermined temperature for a predetermined time.
When an uncrosslinked elastomer of synthetic rubber is used as the uncrosslinked elastomer, a crosslinking reaction can be sufficiently induced only by heat treatment at 130 to 170 ° C. (preferably 140 to 160 ° C.) for about 10 to 30 minutes. There are many.
On the other hand, when an uncrosslinked elastomer of natural rubber is used, the crosslinking reaction can be promoted by using a crosslinking agent. As crosslinking conditions when sulfur is used as such a crosslinking agent, it is preferable to hold at 150 to 170 ° C. (preferably 160 to 165 ° C.) for about 1 hour.
As the crosslinking conditions, optimum conditions can be adopted depending on the used crosslinking agent.

By crosslinking the uncrosslinked elastomer in this manner, a rubber component crosslinked in a net shape can be formed in cellulose particles or cellulose single fibers. The cellulose particles or cellulose single fibers are impregnated with 5% by weight or more of rubber components in the cellulose particles or cellulose single fibers, and the rubber components are crosslinked in a net shape.
For this reason, even if an impact force is repeatedly applied to cellulose particles or cellulose single fibers, the rubber component can absorb the impact force in the cellulose particles or cellulose single fibers, and the impact resistance of the cellulose particles or cellulose single fibers can be improved.
Accordingly, the cellulose particles can be industrially used as blast particles for deburring resin molded products and cleaning resin molded dies. Cellulose monofilaments can also be used for industrial applications such as bag filters.
Here, when the rubber component impregnated in the cellulose particles or cellulose single fibers is less than 5% by weight, the impact resistance of the cellulose particles or cellulose single fibers cannot be sufficiently improved.
The rubber component may be a natural rubber component or a synthetic rubber component, but by using the natural rubber component, all the cellulose particles or cellulose single fibers having improved impact resistance exist in nature. It can be composed of materials and maintain biodegradable properties.

(1) Preparation of cellulose particles Viscose is discharged into a hydrochloric acid solution, and cellulose particles having an average particle size of 200 μm are scoured and washed with a washing liquid in which a weak alkaline detergent and a nonionic detergent having a bath ratio of 10 to 15 are added. Then, it was dried to a nearly dry state.
(2) Preparation of dispersion of uncrosslinked elastomer (a) Put 2.5 g of kneaded natural rubber into a mixer (manufactured by Tiger Co., Ltd., SKO-B700), and cut the molecular chain of natural rubber. The rotating blades of the mixer were rotated at a rotational speed of 16,500 rpm to give a high-speed beater for 90 seconds against natural rubber.
10 parts by weight of the elastomer taken out from the mixer was added to 90 parts by weight of benzene and stirred to obtain a dispersion containing 10% by weight of uncrosslinked elastomer.
(B) Separately from the uncrosslinked elastomer dispersion, a crosslinking accelerator solution in which zinc oxide as a crosslinking accelerator was dissolved was prepared. Such crosslinking accelerator solution, zinc oxide 1 part by weight, ammonium 1 part by weight chloride, was added to a solution of methanol, 4 parts by weight and glycerol 2 parts by weight, tetrafluoroethylene of a fluorinated surfactant Is added dropwise, and 3 parts by weight of isopropyl is added with stirring.
Further, a solution prepared by dissolving 1 part by weight of a commercially available conductive resin in 7.8 parts by weight of isopropyl was added as an antistatic agent.
(C) 25 parts by weight of a crosslinking accelerator solution is added to a solution obtained by adding 25 parts by weight of benzene to 50 parts by weight of the dispersion of the uncrosslinked elastomer thus prepared. In the finally obtained dispersion of the uncrosslinked elastomer, 5% by weight of the natural rubber elastomer is dispersed.
At this time, if the liquid phase becomes unstable and separation is a concern, the liquid phase can be stabilized by adding a small amount of a tetrafluoroethylene or nonionic penetrant as a fluorine-based surfactant. I tried to change.

(3) Immersion of cellulose particles Uncrosslinked in (2) obtained by adding a cross-linking accelerator solution to a 4,000 mesh bag with the cellulose particles scoured, washed and completely dried in (1). It was immersed in a dispersion of the elastomer. The bath ratio in this case was 5.
Next, the dispersion was heated to 60 ° C. with stirring under atmospheric pressure, then cooled to 15 ° C. by natural cooling, re-warmed to 60 ° C. while stirring the cooled dispersion again, and then 15 ° C. Recooled to Such heating and cooling of the dispersion were repeated 4 to 5 times.
(4) Cleaning of Soaked Cellulose Particles After washing cellulose particles taken out from the elastomer dispersion liquid by immersing them in a mixed organic cleaning solution of 70 parts by weight of benzene and 30 parts by weight of isopropyl alcohol at a bath ratio of 10, a nonionic detergent ( 1 to 2% by weight) and a weakly basic detergent (2 to 3% by weight) were mixed and washed at a bath ratio of 10 for cleaning. This washing is for preventing the dispersion of the elastomer from remaining on the surface of the cellulose particles and blocking the cellulose particles from each other.
Further, the cellulose particles were sufficiently washed with water so that no detergent remained, then subjected to centrifugal dehydration treatment and then dried (120 ° C., 2.5 hours).
(5) Crosslinking Cellulose particles impregnated with the elastomer obtained in (4) were immersed in a 3 wt% sulfur solution obtained by adding sulfur powder to carbon disulfide at a bath ratio of 10 Hold at room temperature for 2-4 hours.
The cellulose particles taken out from the solution were washed with water to remove carbon disulfide and sulfur deposited on the surface, and then dried.
Next, the cellulose particles impregnated with sulfur and an elastomer of natural rubber are inserted into an oven heated to an atmospheric temperature of 165 ° C. and held for 1 hour to obtain an elastomer contained in the cellulose particles. Crosslinking was applied.
The obtained cellulose particles were particles having a slightly brown surface. The amount of the rubber component impregnated in the cellulose particles was 6.8% by weight when calculated from the weight of the cellulose particles before dipping in the dispersion and the weight of the cellulose particles after completion of the crosslinking treatment.
In addition, the cellulose particles having a natural rubber component cross-linked therein disappeared in about three months in autumn when buried in the ground.

The impact resistance of the cellulose particles impregnated with the rubber component obtained in Example 1 was measured. An outline of the measuring apparatus is shown in FIG. The measuring apparatus shown in FIG. 1 has a concave portion 12 with a diameter of 9 mm and a depth of 20 mm of a metal mortar 10 filled with 0.2 g of the cellulose particles obtained in Example 1, and the casing 14 having a weight of 100 g is naturally formed. The cellulose particles were dropped to give an impact. The number of drops of the housing 14 was counted.
When the number of natural drops of the casing 14 reached 20000, the state of the cellulose particles was observed with an electron microscope. As shown in FIG. 2 (a), the cellulose particles were deformed but cracked. There was almost no.
Next, the impact resistance was investigated in the same manner using the measuring apparatus shown in FIG. 1 except that the cellulose particles scoured, washed and absolutely dried in Example 1 (1) were used.
That is, when the number of drops of the casing 14 reached 20000, the state of the cellulose particles was observed with a microscope. As shown in FIG. 2B, most of the cellulose particles were cracked or cracked.

In Example 1, a cellulose component was impregnated with a rubber component in the same manner as in Example 1, except that scoured yarn of rayon yarn (75 denier, 7 filaments) as cellulose fiber was used instead of cellulose particles. A processed yarn was obtained.
The obtained processed yarn has a slightly brown surface. The amount of the rubber component impregnated in the single fiber of the obtained processed yarn is 6.5 when calculated from the weight of the raw yarn or scoured yarn before dipping in the dispersion and the weight of the processed yarn after completion of the crosslinking treatment. It was -7.8 wt%.

Next, the impact resistance of the obtained processed yarn was measured. An outline of the measuring apparatus is shown in FIG. In the measuring apparatus shown in FIG. 3, a 15 g weight 18 is attached to the other end of the processed yarn 16 with one end fixed, and a predetermined tension is applied to the processed yarn 16. In this way, the middle of the processed yarn 16 to which a predetermined tension is applied is located on the upper surface of the table 20 fixed on the base, and the upper surface of the table 20 has a weight of 100 g and a diameter of 6.5 mm. A housing 22 is provided. The housing 22 naturally falls and gives an impact to the processed yarn 16.
This impact was repeatedly applied until the processed yarn 16 was cut, and the number of times the casing 22 was naturally dropped until the processed yarn 16 was cut was counted.
In addition, for the raw yarn and scoured yarn of the rayon yarn (75 denier, 7 filaments) before being immersed in the dispersion in which the uncrosslinked elastomer is dispersed, the raw yarn and scoured yarn are also measured using the measuring device shown in FIG. The number of natural drops of the case 22 until each of the pieces was cut was counted.
Table 1 below shows the number of natural drops of the case 22 until each of the scoured yarn and the processed yarn is cut, where the number of natural drops of the case 22 until the raw yarn is cut is 1.

As is clear from Table 1, the impact resistance of the processed yarn is improved about 17 times that of the raw yarn.

In Example 1, a rubber component was impregnated in a cellulose single fiber in the same manner as in Example 1 except that a scouring yarn of cotton yarn (75 denier, 7) was used as cellulose fiber instead of cellulose particles. A processed yarn was obtained.
The obtained processed yarn has a slightly brown surface. The amount of the rubber component impregnated in the single fiber of the obtained processed yarn is calculated from the weight of the scoured yarn before dipping in the dispersion and the weight of the processed yarn after the completion of the crosslinking treatment. It was 2% by weight.
Next, the measurement of the impact resistance of the processed yarn and the raw yarn and the scoured yarn of the cotton yarn (40th twin yarn) before being immersed in the dispersion in which the uncrosslinked elastomer is dispersed is described in Examples. Same as 3.
Table 2 below shows the number of natural drops of the case 22 until each of the scoured yarn and the processed yarn is cut, where the number of natural drops of the case 22 until the raw yarn is cut is 1.

As is clear from Table 1, the impact resistance of the processed yarn is improved about 17 times that of the raw yarn.

(1) Cellulose fiber The rayon yarn (75 denier, 7 filaments) used in Example 3 and the cotton yarn (40th yarn) used in Example 4 were used.
(2) Preparation of dispersion liquid Uncrosslinked elastomer of natural rubber (granular product: as a result of particle size distribution measurement, peaks were present at particle diameters of 200 dnm and 1000 dnm) diluted with water to obtain a solid content of 15% And a small amount of a fluorosurfactant was added.
(3) Immersion treatment Two containers storing the prepared dispersion were prepared, and each of the prepared rayon yarn and cotton yarn was immersed alone. In this immersion treatment, the bath ratio was set to 20, and the heating / slow cooling operation in which the temperature was kept at 45 ° C. for 2 hours at the temperature of the dispersion and then gradually cooled for 10 hours was repeated three times.
Next, each of rayon yarn and cotton yarn was squeezed with a roller of about 15 kg, and then washed with water. It was confirmed that there was no uncrosslinked elastomer on the surfaces of the washed rayon yarn and cotton yarn.
Furthermore, the water-washed rayon yarn and cotton yarn were immersed in a 5 to 10% alcohol solution to completely coagulate the remaining uncrosslinked elastomer, and then air-dried for 24 hours.
(4) Crosslinking The air-dried rayon yarn and cotton yarn were heat-treated at 90 ° C. for 120 minutes to crosslink the uncrosslinked elastomer to obtain a processed yarn. The amount of the rubber component impregnated in the single fiber of the obtained processed yarn is 2.0 when calculated from the weight of the raw yarn or scoured yarn before dipping in the dispersion and the weight of the processed yarn after the crosslinking treatment is completed. It was -8.8 weight%.
(5) Impact resistance The impact resistance of the obtained processed yarn was measured in the same manner as in Example 3. The results are shown in Table 3.

As is apparent from Table 3, it can be seen that the impact resistance of the processed yarn is greatly improved over the original yarn. In particular, the impact resistance of cotton yarn is greatly improved. Since the single fiber of the cotton yarn is hollow, it is considered that the uncrosslinked elastomer has entered the hollow of the single fiber and has been crosslinked.

(1) In Example 5, the immersion treatment was performed in the same manner as in Example 5 except that the dispersion was changed to the following dispersion and immersion treatment.
[Dispersion]
A commercially available synthetic rubber uncrosslinked elastomer (granular product: as a result of particle size distribution measurement, the particle size distribution was a normal distribution with a peak only at a particle size of 210 dnm) diluted with water to obtain a solid content of 10 % And 15%, and a small amount of a fluorosurfactant was added.
[Immersion treatment]
Four containers storing the prepared dispersion were prepared, and each of the prepared rayon yarn and cotton yarn was dipped alone. In this dipping process, the liquor ratio was 15, it was maintained 45 ° C. 2 hours at a temperature of the dispersion was performed repeatedly three times heating and slow cooling operation for annealing 10 hours.
Subsequently, each of the rayon yarn and the cotton yarn was manually drawn and then drawn with a roller of about 15 kg and washed with water. It was confirmed that there was no uncrosslinked elastomer on the surfaces of the washed rayon yarn and cotton yarn.
Furthermore, it was immersed in a 1% calcium chloride solution in water-washed rayon yarn and cotton yarn to completely coagulate the remaining uncrosslinked elastomer, and then air-dried for 24 hours.
(2) Crosslinking Air-dried rayon yarn and cotton yarn were heat-treated at 162 ° C. for 10 minutes to crosslink the uncrosslinked elastomer to obtain a processed yarn. The amount of the rubber component impregnated in the single fiber of the obtained processed yarn is 5.9 when calculated from the weight of the raw yarn or scoured yarn before dipping in the dispersion and the weight of the processed yarn after the crosslinking treatment is completed. -14% by weight.
(3) Impact resistance The impact resistance of the obtained processed yarn was measured in the same manner as in Example 3. The results are shown in Table 4.

As is apparent from Table 4, it can be seen that the impact resistance of the processed yarn is greatly improved over the original yarn. In particular, the improvement in impact resistance at a level using a dispersion having a solid content of 15% is large, and in particular, the improvement in impact resistance of cotton yarn is extremely large.

10 Mill 12 Recess 14, 22 Housing 16 Processing thread 18 Weight 20

Claims (6)

A step of immersing particles or single fibers, which are cellulose molded products made of cellulose, in a dispersion in which an uncrosslinked elastomer is dispersed, and impregnating the dispersion into the particles or single fibers;
A drying step of drying the particles or single fibers impregnated with the dispersion ;
Immersing the dried particles or single fibers in a crosslinking agent solution mixed with a crosslinking agent, and impregnating the particles or single fibers with the crosslinking agent solution;
A drying step of drying the particles or single fibers impregnated with the crosslinking agent solution ;
A crosslinking step of heating the dried particles or single fibers to crosslink the uncrosslinked elastomer impregnated in the particles or single fibers,
A method for producing a cellulose molded product, comprising: obtaining a cellulose molded product in which a rubber component, which is the elastomer crosslinked by a crosslinking agent, is mixed in the particles or single fibers themselves by 5% by weight or more. Before the drying step of drying the particles or single fibers impregnated with the dispersion, it has a washing step of washing and removing the dispersion adhering to the surface of the particles or single fibers,
Before the drying step of drying the particles or single fibers impregnated with the cross-linking agent solution, it has a cleaning step of cleaning and removing the cross-linking agent solution adhering to the surface of the particles or single fibers. The method for producing a cellulose molded article according to claim 1. The method for producing a cellulose molded article according to claim 1 or 2, wherein the step of impregnating the dispersion liquid into the particles or single fibers is performed under reduced pressure or under pressure. The method for producing a cellulose molded product according to any one of claims 1 to 3, wherein an uncrosslinked elastomer of natural rubber or synthetic rubber is used as the uncrosslinked elastomer. The method for producing a cellulose molded product according to any one of claims 1 to 4, wherein an uncrosslinked elastomer having an average molecular weight of 7000 or less is used as the uncrosslinked elastomer. The method for producing a cellulose molded product according to any one of claims 1 to 5, wherein an uncrosslinked elastomer having a low molecular weight imparted with a mechanical shear force is used as the uncrosslinked elastomer.