JPH083820A - Acetate conjugate fiber having latent crimp and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain an acetate conjugate fiber having latent crimp, capable of exhibiting flexible soft touch and bulky feeling and at the same time having sufficient crimping characteristics. CONSTITUTION:A cellulose diacetate having an average acetate ratio of <56.2% and a cellulose triacetate having an average acetate ratio of 56.2-62.5% are subjected to side-by-side type conjugate spinning to obtain a precursor fiber having a single fiber fineness of 1.0-2.5 denier. The precursor fiber is subjected to saponification treatment with an alkali aqueous solution to obtain the objective latent crimp-having fiber which is composed of a cellulose acetate component or a cellulose component having an average acetate ratio of <48.8% and a cellulose triacetate component having an average acetate ratio of 56.2-62.5% each of which is attached to each other in a side-by-side state and has a single fiber fineness of 0.8-2.0 denier, bulkiness of >=22.0cm<3>/g and shrinkage of >=30%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latently crimpable acetate conjugate fiber and a method for producing the same.

[0002]

2. Description of the Prior Art Acetate fibers have a high gloss, a dry feel, a deep color tone, and an excellent affinity with other fibers, but on the other hand, they have a slight lack of swelling and lightness. This is due to the basic spinning method of the raw yarn production, in which the acetate fiber is produced by the dry spinning method. However, also in the acetate fiber, due to the diversification of consumer needs, a fiber having a swelling feeling and a lightweight feeling is demanded. Therefore, for example, a method of deforming the nozzle shape in the spinning process to make the fiber have an irregular cross section, or Although methods such as post-processing bulky processing of fibers have been proposed, these methods often result in insufficient swelling feeling, or even when a swelling feeling is obtained, firmness and elasticity are impaired.

Therefore, there has been proposed a method in which acetate spinning stock solutions having different concentrations are used for composite spinning in a side-by-side type and crimping is given by hot water treatment (Japanese Patent Publication No. 43-25941). Although it can be obtained, it does not reach a satisfactory swelling feeling.

There is also a method in which two components having different acetylation degrees are composite-spun into a side-by-side type and subjected to alkali treatment to develop spontaneous crimps. When the component ratio is increased, the soft feeling is improved, but the bulkiness cannot be sufficiently increased.
On the other hand, if the component ratio of the low acetylation degree component, which is the contracted portion in the obtained acetate conjugate fiber, is increased, the bulkiness is increased, but it is difficult to obtain a supple soft texture.

Further, it is possible to give a large bulky height and a soft texture by a method of varying the high acetylation component and the low acetylation component along the fiber axis direction, but the spontaneous crimping which develops in the filament. In some cases, the crimping force is insufficient and sufficient crimp expression cannot be obtained depending on the structure of the woven or knitted fabric.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to combine the expansion of the difference in acetylation degree between the composite components in the acetate composite fiber and the ultrafineness of the single fiber fineness, and the object of the present invention is suppleness. It is an object of the present invention to provide a latently crimpable acetate conjugate fiber that exhibits a soft texture and a large bulge and has a sufficient crimping force.

[0007]

The gist of the present invention is that the cellulose acetate component having an average acetylation degree of less than 48.8% or the cellulose component and the cellulose triacetate component having an average acetylation degree of 56.2 to 62.5% are side by side. Latent crimpability, which is bonded to a mold, is an acetate composite fiber having a single fiber fineness of 0.8 to 2.0 denier, and has a bulkiness of 2.0 cm ³ / g or more and a crimping rate of 30% or more. Acetate composite fiber, and

[0008] Cellulose diacetate having an average acetylation degree of less than 56.2% and cellulose triacetate having an average acetylation degree of 56.2% to 62.5% are composite-spun in a side-by-side type to have a single fiber fineness of 1.0 to 2 A method for producing a latently crimpable acetate conjugate fiber, which comprises subjecting a precursor fiber having a denier of 0.5 to a saponification treatment with an alkaline aqueous solution.

The latently crimpable acetate conjugate fiber of the present invention has a composite structure in which two kinds of constituent components are bonded side by side, and one constituent component has an average acetylation degree of less than 48.8%. Cellulose acetate or cellulose, and the other component has an average degree of acetylation of 56.
2 to 62.5% cellulose triacetate.

In the latently crimpable acetate conjugate fiber of the present invention, the single fiber fineness is 0.8 to 2.0 denier (hereinafter referred to as d), and 2 according to the measuring method in Examples described later. It has a bulkiness of 0.0 cm ³ / g or more and a crimp ratio of 30% or more, and such a large bulkiness and crimp ratio, combined with the fineness of the fiber, give a supple and soft texture and a feeling of swelling. Bring

The latently crimpable acetate conjugate fiber of the present invention is obtained as follows. That is, the average degree of acetylation is 5
Less than 6.2%, preferably less than 56.2% average acetylation 4
Cellulose diacetate of 8.8% or more and average acetylation degree of 5
6.2% -62.5% of cellulose triacetate was composite-spun into a side-by-side type, and the single fiber fineness was 1.0-
It is obtained by subjecting the precursor fiber of 2.5d to saponification treatment with an alkaline aqueous solution.

By the saponification treatment with an alkaline aqueous solution, the cellulose diacetate component having an average degree of acetylation of less than 56.2% is selectively saponified in the composite component of the precursor fiber, and the degree of acetylation is 48 depending on the treatment conditions. A cellulose acetate having a low acetylation degree of less than 0.8% or a cellulose having an acetylation degree of 0% is obtained. In addition, due to the partial reduction of the cellulose diacetate component in this alkali saponification treatment, the total amount of the original precursor fibers was
〜20wt% is reduced and single fiber fineness is 0.8〜2.0
d.

The method for obtaining the latently crimpable acetate conjugate fiber of the present invention will be further described. The composite ratio (weight ratio) of the cellulose diacetate component and the cellulose triacetate component constituting the precursor fiber is particularly limited. However, the preferred composite ratio is
Cellulose diacetate component / cellulose triacetate component = 40/60 to 60/40.

In producing the precursor fiber, in order to obtain the latently crimpable acetate conjugate fiber of the present invention having the single fiber fineness of 0.8 to 2.0 d, the single fiber fineness of the precursor fiber is 1.0 to
It is necessary to set it to 2.5d, preferably 1.2 to 2.0d. In order to obtain a precursor fiber having such a single fiber fineness, there are methods such as using a spinning nozzle having a fine pore diameter during the production of the precursor fiber, increasing a draft from spinning to winding, or using a diluted spinning dope. However, the means to be used is determined in consideration of the yarn physical properties of the obtained acetate conjugate fiber, manufacturing equipment and the like.

Then, the latently crimpable acetate composite fiber of the present invention is obtained by subjecting the precursor fiber to saponification treatment with an aqueous alkali solution. The saponification treatment is carried out by adding the precursor to an aqueous solution of an alkali compound such as sodium hydroxide or calcium carbonate. It is carried out by a method such as dipping the fibers. The treatment conditions vary depending on the alkali compound, the composition of the precursor fiber, etc., but when sodium hydroxide is used, the concentration of sodium hydroxide is less than 5 wt%, the treatment temperature is 30 to 100 ° C.
The processing time is less than a minute.

By the alkali saponification treatment, the precursor fiber is selectively saponified and reduced in its cellulose diacetate component, the degree of acetylation becomes lower, high shrinkage occurs, and crimps are developed. Since the single fiber fineness is extremely thinned, the frequency of occurrence of helical coil-like crimps in the fiber axis direction, which is developed by alkali saponification treatment, is further increased, resulting in a bulk height of 2.0 cm ³ / g or more and 30 Thus, the latent crimpable acetate conjugate fiber of the present invention having a crimp ratio of not less than%, exhibiting a soft and soft texture and a large bulge and having a sufficient crimping force can be obtained.

[0017]

The present invention will be described below in detail with reference to examples. The methods for measuring bulkiness, crimp ratio, and texture showing the swelling feeling in Examples and Comparative Examples are shown below.

Bulkiness: The sample fibers are 6 mm wide and 3 deep.
0.1 g / d in the groove of the roll having the groove of 3.5 mm
The weight W of the sample wound in the groove portion and the volume V of the groove portion occupied by the sample are measured, and the bulk height D (cm ³ /
g) was calculated from the formula D = V / W. Crimping rate: One end of the sample was fixed, a sample length A after 30 seconds after applying a load of 10 mg / d, and a sample length B after 30 seconds after applying a load of 1 g / d, and crimping was performed. The rate Ce (%) was calculated from the formula Ce = (B−A) / B × 100. Texture: Softness was judged by a sensory test, and it was shown in the order of ◎, ○, △, × from the most favorable one.

Example 1 Cellulose triacetate having an average acetylation degree of 61.6% and cellulose diacetate having an average acetylation degree of 55.2% were each dissolved in a mixed solvent of methylene chloride / methanol (= 91/9). A cellulose triacetate spinning stock solution and a cellulose diacetate spinning stock solution each having a stock solution concentration of 22% by weight were prepared. Cellulose triacetate component / cellulose diacetate component = 50/50 by dry spinning using these spinning dope.
Side-by-side type composite spinning was carried out at the composite ratio (weight ratio) of to obtain a precursor fiber of 50d / 20 filament (hereinafter referred to as f).

Next, this precursor fiber was dipped in an alkaline aqueous solution under the following conditions and saponified. Alkaline aqueous solution Sodium hydroxide 1 wt% aqueous solution Temperature 60 ° C Time 10 minutes Bath ratio 1: 100 The obtained fiber is composed of a cellulose component having an acetylation degree of 0% and a cellulose triacetate component having an acetylation degree of 61.6% in a side-by-side type. It has a laminated composite structure,
Table 1 shows the actually measured fineness, physical properties, bulkiness, crimp ratio, and texture of the fibers.

Example 2 Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare a cellulose triacetate component / cellulose diacetate component = 50/5.
Side-by-side type composite spinning was performed at a composite ratio of 0, and 40
A precursor fiber of d / 20f was obtained. Next, this precursor fiber was alkali-saponified under the same conditions as in Example 1. The obtained fiber contains a cellulose component having an acetylation degree of 0% and an acetylation degree of 6%.
It has a composite structure in which 1.6% of cellulose triacetate component is pasted in a side-by-side type, and Table 1 shows the actually measured fineness of fibers, fiber physical properties, bulkiness, crimp ratio, and texture.

Example 3 Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare a cellulose triacetate component / cellulose diacetate component = 50/5.
Side-by-side type composite spinning was performed at a composite ratio of 0,
A precursor fiber of d / 20f was obtained. Next, this precursor fiber was alkali-treated under the same conditions as in Example 1. The obtained fiber is composed of a cellulose component having an acetylation degree of 0% and an acetylation degree of 61.
It has a composite structure in which 6% of a cellulose triacetate component is pasted in a side-by-side type, and Table 1 shows the actually measured fineness of fibers, fiber physical properties, bulkiness, crimp ratio, and texture.

(Comparative Example 1) Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare a cellulose triacetate component / cellulose diacetate component = 50/5.
Side-by-side type composite spinning was performed at a composite ratio of 0, and
A precursor fiber of d / 20f was obtained. Next, this precursor fiber was alkali-treated under the same conditions as in Example 1. The obtained acetate conjugate fiber has a side-by-side type composite structure of a cellulose component having an acetylation degree of 0% and a cellulose triacetate component having an acetylation degree of 61.6%. , Bulk height, crimp ratio, and texture.

Comparative Example 2 Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare cellulose triacetate component / cellulose diacetate component = 65/3.
Side-by-side type composite spinning was performed at a composite ratio of 5, and
A precursor fiber of d / 20f was obtained. Next, this precursor fiber was alkali-treated under the same conditions as in Example 1. The obtained acetate conjugate fiber has a side-by-side type composite structure of a cellulose component having an acetylation degree of 0% and a cellulose triacetate component having an acetylation degree of 61.6%. , Bulk height, crimp ratio, and texture.

Comparative Example 3 Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare a cellulose triacetate component / cellulose diacetate component = 35/6.
Composite spinning was carried out at a composite ratio of 5 to obtain a precursor fiber of 75d / 20f. Next, this precursor fiber was alkali-treated under the same conditions as in Example 1. The obtained acetate conjugate fiber has a cellulose component with an acetylation degree of 0% and an acetylation degree of 61.6%.
It has a side-by-side composite structure with the cellulose triacetate component, and Table 1 shows the measured fineness of the fiber, the physical properties of the fiber, the bulkiness, the crimp ratio, and the texture.

(Comparative Example 4) Using the same cellulose triacetate spinning dope and cellulose diacetate spinning dope as used in Example 1, a dry spinning method was used to prepare a cellulose triacetate component / cellulose diacetate component = 50/5.
Side-by-side type composite spinning was performed at a composite ratio of 0, and a precursor fiber of 75d / 20f having a fluctuation range of ± 20% or more in the fiber axis direction with respect to the average value of the area ratio of the cellulose triacetate component in the fiber cross section of the entire fiber. Got Next, this precursor fiber was alkali-treated under the same conditions as in Example 1. The obtained acetate conjugate fiber has a degree of acetylation of 0.
% Cellulose component and a cellulose triacetate component having a degree of acetylation of 61.6% have a side-by-side composite structure, and Table 1 shows measured fiber fineness, fiber physical properties, bulk height, crimp ratio, and texture. .

Comparative Example 5 Cellulose triacetate having an average degree of acetylation of 61.6% was dissolved in a mixed solvent of methylene chloride / methanol = 91/9 according to a conventional method for producing acetate fibers, and a stock solution concentration was 21.95% by weight. % Cellulose triacetate spinning stock solution was prepared. Using this spinning dope, a cellulose triacetate fiber of 75d / 20f was obtained by a dry spinning method. Table 1 shows the actually measured fineness, physical properties, bulkiness, and texture of the fibers.

[0028]

[Table 1]

The fibers of Examples 1 to 3 of the present invention have a slightly lower tenacity and elongation than the conventional triacetate fiber of Comparative Example 5, but there was no problem in practical use. Further, the fiber of the present invention is excellent in bulkiness, crimping property, and texture as compared with the fiber obtained from the composite fiber of Comparative Examples 1 to 3 having a single fiber fineness of more than 2.5 d. There is. Further, as compared with the fiber obtained from the composite fiber in which the area ratio of the constituent components of Comparative Example 4 varies, the bulkiness and the texture are about the same, but the crimping property is excellent and it is supple and soft. It had a good texture and a good swelling feeling, and had a large crimping force.

[0030]

EFFECT OF THE INVENTION The latently crimpable acetate conjugate fiber of the present invention has a soft texture and a good swelling feeling, which is completely different from the dry and silky texture of the conventional acetate fiber, and has a single fiber fineness. By ultra-fine, which has a supple and soft texture, large bulkiness and good crimping force at the same time, the present invention, it is possible to expand the application as an acetate fiber, Its value is extremely large.

Claims (2)

[Claims] 1. A cellulose acetate component or cellulose component having an average acetylation degree of less than 48.8% and an average acetylation degree of 56.
2-62.5% of cellulose triacetate component is pasted on the side-by-side type, and the single fiber fineness is 0.8-
A latent crimpable acetate conjugate fiber which is a 2.0 denier acetate conjugate fiber and has a bulkiness of 2.0 cm ³ / g or more and a crimp rate of 30% or more. 2. A side-by-side composite spinning of cellulose diacetate having an average acetylation degree of less than 56.2% and cellulose triacetate having an average acetylation degree of 56.2% to 62.5% is performed to obtain a single fiber fineness of 1.0. A method for producing a latently crimpable acetate conjugate fiber, which comprises subjecting an acetate conjugate precursor fiber having a denier of about 2.5 to saponification treatment with an alkaline aqueous solution.