JPH05230742A - Knit fabric containing cotton and its production - Google Patents

Abstract

PURPOSE:To obtain knit fabric, containing cotton, having level dyeing properties, high dyeing concentration, soft hand, body, high tenacity and shrinkproof properties and excellent in gloss. CONSTITUTION:The objective cotton knit fabric is constructed of cotton yarn containing cotton fiber having cellulose I, cellulose II and cellulose III type crystal structures with respective contents in the order of cellulose III>cellulose I>cellulose II and the cellulose III accounting for >=40% in the crystal. Furthermore, the objective method for producing the knit fabric is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cotton-containing knitted fabric excellent in levelness and softness, softness and elasticity, and strength and shrink resistance, and a method for producing the same.

[0002]

2. Description of the Related Art Cotton fibers are excellent in water absorption and dyeability,
It has been used for clothing for a long time, but since it is a natural fiber, its fiber structure changes variously depending on the species and the climate of the area where it is grown. Therefore, a difference in dyeing may occur in the cotton yarn. As a method for improving the dyeability of cotton yarn, it has been practiced to mercerize a cotton sliver or yarn from the past. Since the stress of the yarn remains, the shrinkage property of washing is deteriorated or the product is skewed and the product has poor dimensional stability. In addition, there is a defect that irregularity when dyed or sliver-like in the yarn when mercerized causes uneven dyeing or dyeing stage. For this reason, a method of improving the knitted fabric by performing a mercerizing process with caustic soda has been performed.

[0003]

[Problems to be Solved by the Invention) However,
In this method of mercerizing with a knitted fabric, the yarn becomes rigid and the texture slightly deteriorates the original taste of cotton, and the wrinkle resistance is improved, but it is not sufficient. Further, even in the case of uniform dyeability, there are cases in which defects such as dyeing stage may occur. Regarding the gloss as a knitted fabric, the gloss due to the mercerization of the yarn does not always give a good effect. When the stress is released due to knitting, the yarn as a fiber aggregate may be disturbed and shrinkage may be reduced, resulting in glossiness. Since it is large, there is a drawback that it is necessary to prepare a knitted fabric having a width wider than the target finished width in advance with a knitting machine having a large diameter. [0004]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention has a crystal structure of (I) cellulose I, (II) cellulose II and (III) cellulose III, and the content of each is in the order of III>I> II, and III / ( I + II + III) A cotton-containing knitted fabric composed of cotton-containing yarns containing a crystalline structure cotton fiber satisfying 0.4 or more, and a knitted fabric formed from a cotton-containing yarn containing a mercerized cotton fiber, continuously or intermittently. It is a method for producing a knitted fabric containing cotton, which is characterized in that it is treated with liquid ammonia.

The crystal structure existing in natural cotton fibers is cellulose I, and cellulose II is produced by the usual mercerizing process, and more than half of cellulose I is converted to cellulose III. In the course of this change, the fine structure inside the fiber changes and the pores (pores) where the dye is easily adsorbed increase. However, this change slightly changes depending on the conditions of the mercerization process, and does not significantly change the fine structure formed and held by the fiber itself during the growth process. Therefore, the dyeing difference cannot be sufficiently eliminated only by the mercerizing process. INDUSTRIAL APPLICABILITY The present invention not only eliminates the difference in dyeability possessed by the raw material fibers but also imparts stable dyeability by changing the crystal structure of cellulose to a more stable and stable cellulose III. Is. The content of cellulose III in the total crystal structure of the cotton fiber is 40% or more.

As a method for forming cellulose III inside the cotton fiber, the cotton fiber is in the form of thread or sliver and has a caustic soda concentration of 10 to 30% (preferably 15 to 20%) and a treatment temperature of 0 to 90 ° C. (preferably 10 to 10). 25 ° C.), treatment time 15 seconds to 5 minutes (desirably 1 to 3 minutes), and then mercerizing by washing to form cellulose II, and a cotton yarn containing the mercerized cotton fiber is formed. A method of making a knitted fabric using the knitted fabric, immersing the knitted fabric in liquid ammonia, and then removing the ammonia can be mentioned.

Since liquid ammonia has a strong penetrating power and can be instantly penetrated into the inside of the fiber, the fine structure can be uniformly changed into the inside of the fiber.
The liquid ammonia treatment conditions are as follows: mercerized yarn or sliver is immersed in liquid ammonia and
Ammonia is removed within ~ 90 seconds, preferably within 5-20 seconds.

By the liquid ammonia treatment of the present invention, most of the cellulose II in the mercerized cotton fiber is changed to cellulose III, and the ratio of the crystal structure is cellulose.
III >> Cellulose I> Cellulose II. The fraction of cellulose I in the crystal is preferably 0.35 or less.

Liquid ammonia is preferably used as the agent for forming cellulose III, but it is also possible to use a lower alkylamine such as methylamine or ethylamine. The proportion of the amorphous portion other than crystals is usually 15 to 40%. The cotton fiber of the present invention has a barium activity value (AATCC 89-1958).
When T) is measured, it is a value of about 150 to 180, which is considerably higher than that of a normal mercerized cotton fiber. Further, according to the method of the present invention, in addition to the unexpected effect that the strength of the cotton knit can be significantly improved, it also exhibits effects such as softening the texture, imparting elasticity, and high shrink resistance. Can be made

The term "cotton-containing knitted fabric" as used in the present invention means a knitted fabric obtained from a cotton yarn containing mainly cotton in addition to 100% cotton yarn, and other natural fibers, semi-synthetic fibers, synthetic fibers, etc. besides the cotton yarn. It also includes knitted fabrics that have been mixed (blended, twisted, knitted) within a range that does not impair the property.

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. -Crystal Structure Analysis Method The cotton single fibers constituting the cotton knitted fabric were unwound, and the sample was measured as an parallel fiber bundle by an X-ray diffraction method according to a conventional method. Cellulose type I and cellulose type II and cellulose type I and cellulose type III in mixed crystals were determined by Ranby, BG:: Acta.Chem.Scand., 6 (1952) p.116 and Hayashi et al. , Hokkaido University Research Report, p.83 (1974).

Evaluation method of dyeability: cotton knitted fabric with reactive dye (monochlorotonazine type) 2% owf, sodium carbonate 2
Using a jet dyeing machine with a dyeing bath of 0 g / l and mirabilite 50 g / l,
Exhaust dyeing was carried out at 100 ° C., and the uniformity and color density of the dyed knitted fabric were visually evaluated. ○: Good Δ: Somewhat bad ・ Resin processing method: dyed knitted fabric 5% glyoxal resin, metal catalyst 1.5 %, Silicon Softener 2.0
%, Polyethylene glycol 2.0% was added to the working fluid so that it would be 60% picked up, and then 12
Intermediate drying at 0 ° C for 2 minutes and baking at 150 ° C for 3 minutes were performed. -Gloss: Evaluated by visual judgment O: Good B: Slightly bad-Hand (KES method): Shear rigidity (G), shear hysteresis (2HG) using KES FB-1 (manufactured by Kato Tech). I asked. -Hand (touch method): The knitted fabric was evaluated for softness and tension by touch. -Shrinkproof property: The shrinkage ratio (%) of the warp method of the knitted fabric was measured by the JIS L 1042 F2 tumble method.

Example 1 A cotton yarn of No. 60 twin yarn, which was mercerized in the form of a filament with caustic soda 30 ° Be '(23.5%), was used to obtain a caliber of 30.
A knitted fabric knitted using a knitting machine with an inch and a gauge of 28 G / m ² / cm is continuously impregnated with liquid ammonia at a squeezing ratio of 90%, and then dried for 15 seconds, and then the cotton knitted fabric of the present invention (A ) Got. The cotton fiber yarn in this cotton knitted fabric was analyzed by the X-ray diffraction method and the results were found to be 46% for cellulose III, 21% for cellulose I, 5% for cellulose II and 28% for the amorphous portion.

As a comparative example, caustic soda 30 ° Be '
A mercerized cotton knit (B) was obtained. The analysis results of the cotton fibers in this cotton knitted fabric by the X-ray diffraction method are cellulose II 4
The content was 1%, cellulose I 32%, and amorphous portion 27%.
Also, for comparison, a knitted fabric was formed by using liquid ammonia-treated cotton yarn, and then the knitted fabric was mercerized with caustic soda (C) and a liquid ammonia-treated cotton yarn knitted fabric was treated again with liquid ammonia (D). Got The results of measuring the burst strength of these knitted fabrics are shown in Table 1. It can be seen that the knitted fabric of the present invention has a very high tenacity.

[0015]

[Table 1]

Example 2 For the cotton knits A, B, C and D obtained in Example 1,
Evaluation was carried out by dyeing and resin processing in a conventional manner. The results are shown in Table 2.

[0017]

[Table 2] The cotton knitted fabric of the present invention has an improved level dyeing property, in addition to a deep dyeing effect,
Excellent gloss, soft texture, improved feeling of tension and high shrink resistance.

[0018]

EFFECTS OF THE INVENTION By increasing the content of cellulose III in the crystal structure to a specific amount by treating cotton thread mercerized in thread form or sliver shape with liquid ammonia, the difference in dyeing between fibers is reduced and uneven dyeing is achieved. There is no significant difference in staining to the extent that the occurrence of. A knitted fabric made from this yarn has high strength, is rich in elasticity, is less likely to wrinkle, has better drapeability, and has a soft texture. or,
A cotton-containing knitted fabric having high shrink resistance and excellent gloss and deep dyeing property can be obtained.

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Claims (2)

[Claims] 1. (I) Cellulose I, (II) Cellulose
II and (III) Cellulose having a type III crystal structure, the contents of which are in the order of III>I> II, and III / I
A cotton-containing knitted fabric composed of cotton-containing yarn containing crystal-structured cotton fibers satisfying (I + II + III) of 0.4 or more. 2. A method for producing a cotton-containing knit, comprising continuously or intermittently treating a knitted fabric made of a cotton-containing yarn containing a mercerized cotton fiber with liquid ammonia.