JP3072257B2 - Cellulose acetate fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel cellulose acetate fiber and a method for producing the same.

[0002]

2. Description of the Related Art Cellulose diacetate fiber is preferably used as a material for clothing, because of its excellent hygroscopicity, texture and coloring. However, when cellulose diacetate fiber is subjected to a high-temperature dyeing treatment at 100 ° C. or more, the fiber strength is reduced, and the coloring property is lowered, the texture change is likely to occur, and the cellulose diacetate fiber is mixed with a polyester fiber or the like that requires a high-temperature dyeing treatment. It is difficult to make a composite material for clothing. Therefore, cellulose diacetate fiber is
It is almost limited to its sole use, and its use for outer clothing is limited.

[0003] Cellulose triacetate fiber is
It is extremely hydrophobic compared to viscose rayon, that is, has a small swelling property in water, and has almost no micelle spacing because it is obtained from dry spinning. It does not show sufficient dyeing properties for dyes and ionic dyes, and is generally dyed well using a disperse dye under high pressure and high temperature conditions. However, cellulose triacetate fiber has high plasticity, and the setting of the dyeing temperature requires sufficient consideration from the viewpoint of the fiber physical properties and the texture, and the cooling after dyeing is performed by slow cooling so that the generated wrinkles are not fixed. There is a need.

Therefore, a method has been proposed in which cellulose triacetate fiber is swollen with a swelling agent and dyed under mild temperature conditions, but this has an adverse effect on texture and strength.
In addition, in order to ensure level dyeing, equipment improvement is required, and there are problems such as an increase in dyeing cost. In addition, a method of imparting dyeability to direct dyes and the like similar to rayon by dyeing the fiber surface of the cellulose triacetate fiber only by alkali saponification treatment or the like, and a method of imparting dyeing fastness have been proposed. When a cellulose component having a refractive index and a water content that are significantly different from each other constitutes the fiber surface, the color development and the dry texture inherent to cellulose triacetate are greatly different.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cellulose diacetate fiber having a moderate hygroscopicity, a feeling and a coloring property, and a cellulose triacetate fiber having a heat resistance. It is still another object of the present invention to provide a cellulose acetate fiber having dyeability at normal pressure.

[0006]

According to the present invention, an average acetylation degree of 5 is provided.
A core-in-sheath type composite fiber in which 6.2 to 62.5% of cellulose triacetate is arranged in a core portion and cellulose diacetate having an average acetylation degree of 48.8 to 56.1% is arranged in a sheath portion. A cellulose acetate fiber having a weight ratio of 5/95 to 95/5,

The average acetylation degree of the core component is 56.2 to 56.2.
62.5% cellulose triacetate dissolved in an organic solvent in a spinning dope, average acetylation degree of 48.8-5 as a sheath component
A method for producing cellulose acetate fiber, comprising dry spinning a core-sheath type having a core-sheath weight ratio of 5/95 to 95/5 using a spinning stock solution obtained by dissolving 6.1% of cellulose diacetate in an organic solvent. ,It is in.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The cellulose acetate fiber of the present invention is a composite fiber having a core-in-sheath composite structure in which cellulose triacetate is disposed on a core portion and cellulose diacetate is disposed on a sheath portion. Used is cellulose triacetate having an average acetylation degree of 56.2 to 62.5%, and cellulose diacetate having an average acetylation degree of 48.8 to 56.1% is used as the cellulose diacetate in the sheath. Can be

[0009] Further, the ratio of the core to the sheath in the composite fiber,
That is, the core / sheath weight ratio is 5/95 to 95/5, preferably 50/50 to 95/5. Core / sheath weight ratio is 5/9
If it is less than 5, heat resistance and dyeability are insufficient, and 95/5
If it exceeds 3, the hygroscopicity and the coloring property are insufficient.

[0010] The cellulose acetate fiber of the present invention has excellent dyeing properties for disperse dyes, and has not only high pressure but also normal pressure. This improvement in dyeability is achieved by the cellulose diacetate in the sheath part facilitating the penetration and dispersion of the disperse dye into the interior of the fiber, and the dyeing at the interface due to the disorder of the molecular structure generated at the interface between cellulose triacetate and cellulose diacetate. It is presumed to be due to an increase in the amount of deposition.

Further, the cellulose acetate fiber of the present invention has a hygroscopic property, a feeling, a coloring property and a gloss based on the cellulose diacetate in the sheath, and this hygroscopic property is accompanied by an improvement in antistatic property. Further, the cellulose acetate fiber of the present invention has heat resistance based on cellulose triacetate in the core, and does not decrease in fiber properties even when subjected to a treatment under high temperature conditions.

[0012] The cellulose acetate fiber of the present invention is produced as follows. Average acetylation degree 5 as core component
6.2 to 62.5% of cellulose triacetate and cellulose diacetate having an average acetylation degree of 48.8 to 56.1% as a sheath component are mixed with an organic solvent such as methylene chloride or a mixed solvent such as methylene chloride and methanol. Dissolve each,
The concentration of each solution is 15 to 30% by weight, preferably 1
A spinning solution of 8 to 27% by weight is prepared.

The stock solution for spinning cellulose triacetate and the stock solution for spinning cellulose diacetate have a cellulose triacetate / cellulose diacetate ratio of 5/95 to 95/5, preferably 50/50 to 95/5, by weight ratio of core and sheath.
The spinning solution is supplied to a core-sheath composite spinning nozzle device that distributes the spinning solution in a core-sheath type, and is spun into a core-sheath type by a dry spinning method of discharging into a high-temperature atmosphere.

[0014]

The present invention will be described below in more detail with reference to examples. The degree of acetylation, dyeing and dyeability evaluation in the examples were based on the following methods.

<Degree of acetylation> About 2 g of a sample is put into a weighing bottle,
After drying at 105 ° C. for 2 hours, the mixture is cooled in a desiccator by one slow tube, weighed, and the weight of the sample is measured. The sample is then
In a 0 ml Erlenmeyer flask, 100 ml of acetone and 300 ml of dimethyl sulfoxide were added, and after standing for 20 hours, 30 ml of a 1N aqueous solution of sodium hydroxide was added, and the mixture was stirred for 2 hours. Excess sodium hydroxide was titrated with a 1N-sulfuric acid solution to calculate an average acetylation degree.

<Dyeing> A flat knitted fabric obtained by knitting a sample at 28 gauge was scoured and dyed under the following conditions.・ Scouring Score Roll 900 (manufactured by Kao Corporation) 0.2% by weight aqueous solution Bath ratio 1: 100, 80 ° C. × 60 minutes ・ High-pressure high-temperature dyeing (1) Latesil Blue (Disperse dye manufactured by Ciba Geigy) 4.5% by weight Textile) Disper TL (Aidei Chemical Co., Ltd.) 0.5 g / liter Bath ratio 1:35, 130 ° C. × 60 minutes ・ High-pressure high-temperature dyeing (2) Lattesil Blue (Disperse dye manufactured by Ciba-Geigy) 3% by weight (vs. Fiber) Disper TL (Aidener Chemical Co., Ltd.) 0.5 g / liter Bath ratio 1: 100, 130 ° C. × 60 minutes ・ Normal pressure dyeing (3) Lattesil Blue (disperse dye manufactured by Ciba Geigy) 3% by weight (based on fiber) ) Disper TL (Aidei Chemical Co., Ltd.) 0.5 g / l Bath ratio 1: 100, 90 ° C. × 60 minutes ・ Reduction washing Hydrosulfite sodium salt 10% by weight sodium carbonate ( Water) 10 wt% Meisanol BHS NEW 20 wt% bath ratio 1: 100,60 ℃ × 15 minutes

<Evaluation of Dyeing Property> Colorimeter ND-300A
The K / S value was calculated from the Kubelka-Munka equation using the spectral reflectance measured using (manufactured by Nippon Denshoku Industries Co., Ltd.). K
The higher the / S value, the darker the color and the higher the dyeability.

(Examples 1 to 3) Cellulose triacetate having an average acetylation degree of 61.6% and cellulose diacetate having an average acetylation degree of 55.2% were respectively dissolved in a mixed solvent of methylene chloride / methanol = 91/1. Then, a cellulose triacetate spinning stock solution and a cellulose diacetate spinning stock solution having a solution concentration of 22% by weight were prepared. Using both spinning stock solutions, dry spinning was performed with a core-sheath composite spinning nozzle so as to have a core-sheath weight ratio shown in Table 1, to obtain a cellulose acetate fiber of 75 denier / 20 filaments. The yarn quality of the obtained fiber is shown in Table 1, and the flat knitted fabric of the obtained fiber is dyed by high-pressure and high-temperature dyeing (1), dyeability is evaluated, and fiber strength after dyeing is measured. The results are shown in Table 2.

Comparative Example 1 Cellulose diacetate having an average degree of acetylation of 55.2% was prepared using methylene chloride / methanol = 88.
/ 12 to prepare a stock solution of cellulose diacetate spinning having a solution concentration of 22% by weight. Using this spinning dope, dry spinning was performed with a normal spinning nozzle to obtain a cellulose diacetate fiber of 75 denier / 20 filaments. The raw yarn quality of the obtained fiber is shown in Table 1, and the flat knitted fabric of the obtained fiber is dyed by high-pressure and high-temperature dyeing (1), and the dyeability is evaluated and the fiber strength after dyeing is measured. The results are shown in Table 2.

[0020]

[Table 1]

[0021]

[Table 2]

As is clear from Tables 1 and 2, the cellulose diacetate fiber has a remarkably reduced yarn quality, but the yarn quality of the cellulose acetate fiber of the present invention is of such a degree that there is no practical problem even by high-pressure and high-temperature dyeing. And the dyeability is also good.

(Examples 4 to 6) The plain knitted fabric of the cellulose acetate fibers obtained in Examples 1 to 3 was dyed by normal pressure dyeing (3), and the dyeability was evaluated and the fiber strength after dyeing was measured.
Table 3 shows the results.

Comparative Example 2 Cellulose triacetate having an average acetylation degree of 61.6% was prepared by adding methylene chloride / methanol = 9.
The mixture was dissolved in a 1/9 mixed solvent to prepare a cellulose triacetate spinning stock solution having a solution concentration of 22% by weight. Using this spinning dope, dry spinning was performed with a normal spinning nozzle to obtain a cellulose triacetate fiber of 75 denier / 20 filaments. The raw yarn quality of the obtained fiber is 1.32 g in strength.
/ D, elongation of 30.5%, and the obtained flat knitted fabric is dyed by high-pressure and high-temperature dyeing (2), dyeability is evaluated, and fiber strength is measured after dyeing. 3 is shown.

Comparative Example 3 The plain knitted fabric of cellulose triacetate fiber obtained in Comparative Example 2 was dyed by normal pressure dyeing (3), dyeability was evaluated, and fiber strength after dyeing was measured. 3 is shown.

[0026]

[Table 3]

As is clear from Table 3, the cellulose acetate fiber of the present invention was obtained by dyeing under normal pressure, K / S in high pressure and high temperature dyeing of cellulose triacetate fiber.
It shows a higher K / S value than the above value and shows good dyeability. Further, the cellulose acetate fiber of the present invention has a dry feeling, but can be changed to a soft and soft texture with a soft dry feeling by setting the core ratio to a low value.

[0028]

The cellulose acetate fiber of the present invention is
A decrease in fiber properties during the dyeing treatment under high-temperature conditions is suppressed as compared with conventional cellulose diacetate fibers, and the high-temperature dyeing has, of course, good dyeing properties capable of being dyed at normal pressure, and It has a moderate hygroscopicity, and can be mixed with polyester fiber or the like to form a composite material for clothing, and expands its application, such as enabling its use in outer clothing and the like.

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Claims (2)

(57) [Claims] A cellulose triacetate having an average acetylation degree of 56.2 to 62.5% is provided on a core portion, and an average acetylation degree of 48.8 to 48.8%.
A core-sheath type composite fiber in which 56.1% of cellulose diacetate is disposed in a sheath portion, wherein a core-sheath weight ratio is 5/95 to 95/95.
/ 5 cellulose acetate fiber. 2. An average acetylation degree of 56.2 to 6 as a core component.
2.5% cellulose triacetate dissolved in an organic solvent, an undiluted spinning solution, average acetylation degree of 48.8-5 as a sheath component
A method for producing cellulose acetate fiber, comprising dry spinning a core-sheath type having a core-sheath weight ratio of 5/95 to 95/5 using a spinning stock solution in which 6.1% cellulose diacetate is dissolved in an organic solvent. .