JPH1088450A - Stretch knit - Google Patents

Abstract

(57) [Summary] The present invention can industrially provide a stretchable knitted fabric which is rich in stretchability and has very little decrease in strength when wet.
A knitted fabric comprising a multifilament yarn composed of lyocell fiber and a polyurethane-based elastic fiber,
An elastic knitted fabric having a burst strength when wet of the knitted fabric of 2.0 kg / cm ² or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an improvement in stretchable knitted fabric. More specifically, the present invention relates to a stretchable knitted fabric that is thin, highly stretchable, flexible, and has a very small decrease in strength when wet.

[0002]

2. Description of the Related Art Conventionally, when used in clothing, for example, cellulose fibers have a high sweat absorption property, a low electrostatic charge voltage, and have a soft texture. It has been widely used for applications. Cellulosic fibers are particularly preferred for shorts, girdle or sanitary applications because of these advantages and the ease with which dirt is removed by washing.

However, garments made of cellulosic fibers tend to wrinkle when worn, and most fabrics used for inner products are knitted. In many cases, elastic fibers are composited, and such a composite knitted fabric has a problem that, as compared with a knitted fabric made of 100% cellulosic fibers, the cellulosic fibers are greatly damaged by repeated expansion and contraction due to wearing and repeated washing. Also, JP-A-7-31
Japanese Patent No. 6984 proposes a resin processing using a specific resin as the above-mentioned improvement method. As a result, a change in texture after washing and a decrease in quality due to threading can be prevented, but the strength in a wet state is low, and there is a problem that cellulose fibers are greatly damaged by repeated washing and the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a knitted fabric which is thin, has excellent elasticity, is flexible and has a very small decrease in strength especially when wet.

[0005]

Means for Solving the Problems In view of the above problems, the present inventors have studied a knitted fabric composed of a cellulose-based fiber and a polyurethane-based elastic fiber. Although it is an excellent knitted fabric in terms of fitting, the cellulosic fiber becomes fatigued by repeated wearing or repeated washing. In particular, when a regenerated cellulose multifilament is used as the cellulosic fiber, it swells in a wet state. It was found that the strength when wet was significantly reduced, and it was found that the above problem could be solved by using a special fiber as cellulosic fiber, that is, lyocell fiber in combination, and completed the present invention.

That is, the present invention relates to a knitted fabric comprising a multifilament yarn composed of lyocell fiber and a polyurethane-based elastic fiber, wherein the knitted fabric has a burst strength when wet of 2.0 kg.
/ Cm ² or more. The present invention includes the following embodiments. 2. The stretch according to claim 1, wherein the multifilament yarn composed of lyocell fiber has a breaking strength when dried of 3 g / d or more and 5 g / d or less, and a breaking elongation when dried of 5% or more and 10% or less. Sex knitting. When a multifilament yarn composed of lyocell fiber is brought into contact with an alkaline solution, the fiber has a dry breaking strength of 2.8 g / d or more and 4.0 g / d or less, and a dry elongation of 13% or more and 20% or less. The stretchable knitted fabric according to claim 1, wherein the knitted fabric has elasticity. The fineness of the fiber constituting the stretchable knitted fabric is 20 d to 150 as a multifilament yarn composed of lyocell fiber.
d. The stretchable knitted fabric according to claim 1, wherein the polyurethane elastic fibers have a length of 10d to 70d. When the knitted fabric using lyocell fiber is contacted with an alkaline solution, the fiber has a dry breaking strength of 2.8 g / d to 4.0 g / d, and a breaking elongation of 13% to 20 when dried.
% Or less. The stretchable knitted fabric according to claim 1, wherein the water swelling degree of the knitted fabric using lyocell fiber is 65% or less. The stretchable knitted fabric according to claim 1, wherein the stretchable knitted fabric composed of a multifilament yarn composed of lyocell fiber and the polyurethane-based elastic fiber is formed by cross-knitting both fibers. Burst strength when wet of elastic knitted fabric is 2.0 kg / cm
The stretchable knit according to claim 1, wherein the number is ² or more. The method according to claim 1, wherein the treatment of the knitted fabric using the lyocell fiber with an aqueous alkali solution has a concentration of the alkali agent of 50 to 150 g / liter, a treatment temperature of 5 to 60 ° C, and a treatment time of 20 seconds to 2 minutes. A method for producing an elastic knitted fabric.

Hereinafter, the present invention will be described in detail. The lyocell fiber in the present invention refers to a cellulose fiber obtained by spinning during spinning from an organic solvent. More specifically, the lyocell fiber refers to a cellulose fiber obtained by dissolving cellulose in an organic solvent as a solvent to form a cellulose solution, and using this solution as a spinning solution by wet spinning, and further by dry spinning.

For example, as described in JP-B-60-28848, a solution containing a cellulose and a non-solvent such as water dissolved in an organic solvent of cellulose is spun in air or in a non-precipitating medium. Then, it can be produced by stretching the fiber-forming solution discharged from the spinneret at a speed higher than the feeding speed and at a stretching ratio of 3 times or more and then treating with a non-solvent.

The organic solvent at this time may be a known solvent, for example, the following amine oxides disclosed in JP-B-60-28848.
Further, another kind of solvent may be used. In this case, the amine oxides used as the organic solvent include, for example, tertiary amine N-oxides (for example, trimethylamine, triethylamine, tripropylamine, monomethyldiethylamine, dimethylmonoethylamine, monomethyldipropylamine). Oxide: oxide of N-dimethyl-, N-diethyl, N-dipropylcyclohexylamine; oxide of pyridine; N-methylmorpholine N
And cyclic mono (N-methylamine-N-oxide) such as -oxide. The use of N-methylmorpholine N-oxide is preferred.

The stretchable knitted fabric of the present invention has a breaking strength of 3 g / d to 5 g / d when dried, preferably 3 g / d to 4 g / d.
g / d or less; desirably, a multifilament yarn composed of lyocell fiber having characteristics of elongation at break of 5% or more and 10% or less, preferably 7% or more and 10% or less when dried is a constituent element. When the breaking strength at the time of drying is less than 3 g / d, the strength at the time of wetting is greatly reduced, and when the breaking elongation at the time of drying is less than 5%, yarn breakage occurs at the time of knitting. Not preferred. In addition, the breaking strength when dried is 5
If it exceeds g / d, the hand becomes coarse and hard, and if it exceeds 10%, the morphological change of the knitted fabric due to washing is unfavorable.

In particular, by bringing a knitted fabric using lyocell fiber into contact with an alkaline aqueous solution, substantially no wrinkles are generated during the dyeing process of the knitted fabric and during washing of the knitted product, and the surface of the knitted fabric is stabilized. The appearance quality can be greatly improved. In this case, examples of the alkali agent used in the aqueous alkali solution include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and sodium silicate.

A preferred process for bringing a knitted fabric using lyocell fiber into contact with an aqueous alkali solution will be described below. The above-mentioned alkaline agent is used as an aqueous solution having a concentration of 50 to 150 g / l, preferably 50 to 100 g / l. At a concentration of less than 50 g / liter, the effect of improving wrinkles is not sufficient, and at a concentration of more than 150 g / liter, a good effect on the improvement of wrinkles is recognized, but the strength which can withstand a knitted product is not maintained. Treatment temperature with alkaline agent is 5-6
0 ° C, preferably 10 to 40 ° C is desirable. If the temperature is lower than 5 ° C., the strength is largely reduced, and if it exceeds 60 ° C., yellowing occurs, which is not preferable. Processing time with alkaline agent is 20 seconds to 2
Minutes, preferably 30 seconds to 1 minute. If it exceeds 2 minutes, the strength is significantly reduced.

Hereinafter, a method of treating a knitted fabric with an alkaline aqueous solution will be described. The treatment and neutralization of the knitted fabric with an alkaline aqueous solution must be performed in a spread state. The spread state refers to a state in which the knitted fabric is spread. A state in which wrinkles occur like a rope shape cannot be said to be a spread state. Rope-like treatment using a liquid jet dyeing machine or an air current dyeing machine is not preferable because it generates wrinkles and induces dye wrinkles during dyeing. As long as the knitted fabric is in the spread state, either a continuous type or a batch type process can be performed.

For example, in the case of a continuous process, a spread-type continuous scouring machine can be used, and in the case of a batch-type process, a hanging kneading method or the like can be adopted. During processing, the knitted fabric is not subjected to excessive tension. The tension applied to the knitted fabric is preferably a force required to pull the knitted fabric in the warp direction and the weft direction by 0 to 1%, respectively. If the knit is treated under tension, the elongation at break decreases, and the effect of improving wrinkles cannot be obtained. Therefore, it is preferable to use a processing machine or method that applies as little tension as possible in the warp and weft directions of the knitted fabric. For example, it is preferable to use a continuous scouring machine such as a dipping and staying type hineken type scouring machine or a net conveyor type scouring machine, or adopt a suspension kneading method.

It is more preferable to use a continuous scouring machine capable of treating a knitted fabric in a spread state, since the treatment time is relatively short and the treatment can be performed without excessively applying the fabric tension during the treatment. For example, as shown in FIG. 1, when the knitted fabric 1 passes through the guide roll 2 and enters the alkali treatment tank 4 of the dipping and staying type refining machine, the roller 3 of the knitted fabric introduction part hooks the knitted fabric 1 and the treatment liquid 5 In this case, the knitted fabric 1 is spread, and is subjected to alkali treatment without excessive tension. Next, the knitted fabric 1 is similarly treated in the hot water washing tank 6, the neutralization tank 7, and the water washing tank 8, respectively. As the neutralizer in the neutralization tank,
Acetic acid and the like can be mentioned.

When the lyocell fiber of the present invention or a knitted fabric using the fiber is brought into contact with an alkaline solution, the fiber has a dry breaking strength of 2.8 g / d to 4.0 g / d, preferably 2. 8 g / d or more and 3.5 g / d or less; when the breaking elongation at the time of drying is 13% or more and 20% or less, preferably 13% or more and 16.5% or less, the lyocell fiber 65
%, More preferably 40% or more and 65% or less, the knitted fabric maintains a high burst strength when wet.

As the multifilament yarn composed of lyocell fiber, 100% lyocell fiber is optimal, but other cellulose fibers such as viscose fiber and copper-based cellulose fiber impair the function as lyocell fiber. Mixing may be performed in a small amount that is not in the range.

The polyurethane elastic fiber constituting the stretchable knitted fabric of the present invention is a fiber comprising a polymer having a hydroxyl group at both ends and a substantially linear urethane group having a molecular weight of 400 to 5,000. Yes, for example, polyester diol, polylactone diol, polythioether diol, polyester amide diol, polyether diol, one or more of polycarbonate diol, and organic diisocyanate, such as hydrazine having a multifunctional active hydrogen atom, polyol, polyamine, Having a urethane group in the molecule by polymerizing a chain extender such as hydroxylamine, water and a terminal stopper having a polyfunctional active hydrogen atom obtained by reacting, for example, a dialkylamine in one or more steps, and the like. Obtain an elastic polymer, It can be obtained by spinning a polymer solution according to a conventional method.

In the knitted fabric comprising a multifilament yarn composed of lyocell fiber and polyurethane-based elastic fiber according to the present invention, the total denier of the multifilament yarn composed of lyocell fiber constituting the knitted fabric is 20 d to 1 d.
The preferred range of 50d, preferably 20d-80d, and single yarn denier is 0.5d-2d. The polyurethane elastic fibers constituting the knitted fabric preferably have a fineness of 10d to 70d, preferably 10d to 50d. Use polyurethane elastic fiber as bare, FTY with nylon etc.
CSY with cotton or cotton may be used. In knitting, cross-knitting of both fibers is preferably used. In particular, in the case of circular knitting, knitting may be performed by aligning and knitting from the same yarn feeder, or knitting by compounding from the same yarn feeder.

In the stretchable knitted fabric of the present invention, a fabric obtained by cross-knitting both fibers is preferably used. As the knitting structure used for the production of the stretchable knitted fabric of the present invention, especially in circular knitting,
For smooth and warp knitting, half tricot and Russell are preferable, and for the knitting gauge, 24 to 40 GG is preferable for circular knitting. A stretchable knit that satisfies these conditions is particularly thin, retains flexibility, and has a low drop in strength when wet.

The stretch strength of the stretchable knitted fabric when wet is 2.0.
kg / cm ² or more, preferably 2.5 kg / c
m ² or more. If the burst strength when wet is less than 2.0 kg / cm ^{2, the} strength is remarkably reduced by repeated wearing or repeated washing, which is not preferable. The upper limit of the bursting strength when wet is, of course, desirably as large as possible, but generally, from a practical viewpoint, if it is about 4.0 kg / cm ² , the knitted fabric of the present invention sufficiently functions.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to only examples. In addition, physical property evaluation was performed by the following methods. (1) Yarn strength and elongation: Measured in accordance with JIS-L-1013. (2) Degree of water swelling of yarn; The degree of water swelling is calculated by the following equation. Degree of water swelling (%) = [(BA) / A] × 100 A: Absolute dry weight (g) of sample B: Immerse sample in water at 20 ° C. for 30 minutes,
The weight (g) after dehydration using a centrifuge at 3500 rpm for 5 minutes using a centrifuge to remove water adhering to the fiber surface. (3) Burst strength: measured according to JIS-L-1096.

(Manufacture of Lyocell Fiber) JP-B-60-28
According to the production method described in Japanese Patent No. 848, pulp and an aqueous solution of N-methylmorpholine N-oxide were placed in a mixing tank and mixed under reduced pressure to produce a cellulose solution having a cellulose concentration of 10.0%. 124 ° C.
At the discharge temperature of, air gap spinning was performed under the conditions shown in Table 1. The spun yarn is scoured by washing with water, dried and wound up, and has a physical property value of 75 d / 5 shown in Table 1.
0f multifilament yarn was obtained.

[0024]

Example 1 Multifilament test yarn 1 of lyocell fiber obtained in the above-mentioned production method and listed in Table 1 and polyurethane-based elastic fiber (Asahi Kasei Kogyo Co., Ltd .; Asahi Kasei Leica) 30d / 1
28GG sheet made of 0f is scoured and dyed and dried by a conventional method, impregnated with an aqueous solution containing 2% by weight of Nikka Silicon AMZ (manufactured by Nikka Chemical Co., Ltd .: aminosilicone softener), and squeezed at a pickup rate of 85%. Example 1 was dried at 140 ° C. for 2 minutes. The water swelling degree of the obtained sheet is 60.
%, And the burst strength when wet was 3.3 kg / cm ² .

[0025]

Example 2 The 28GG sheet knitted fabric used in Example 1 was subjected to alkali treatment in a spread state by using a dipping and staying type Hinecken continuous scouring machine under the conditions of 70 g / liter of sodium hydroxide, 15 ° C. and 30 seconds. Followed by hot water washing (80 ° C.), neutralization (CH ₃ COOH, pH = 4), scouring (Na ₂ Co ₃
1 g / liter and surfactant (nonionic) 1 ml /
In a bath containing liter, 80 ° C) and drying (120 ° C), followed by scouring and dyeing and drying by a conventional method, and Nikka Silicon AMZ (manufactured by Nichika Chemical Co., Ltd .: amino silicon based softener)
Impregnated in an aqueous solution containing 2% by weight, pickup rate 85%
Example 2 was squeezed and dried at 140 ° C. for 2 minutes.
And The water-swelling degree of the obtained sheet was 64%, and the breaking strength when wet was 3.0 kg / cm ² .

[0026]

Comparative Example 1 A multifilament test yarn 2 of lyocell fiber and a polyurethane elastic fiber (manufactured by Asahi Kasei Kogyo Co., Ltd., trade name: "Asahi Kasei Leica") obtained by the above production method and shown in Table 1.
A 28GG sheet made of 30d / 10f was scoured, dyed, and dried by a conventional method, and treated in the same manner as in Example 1 to obtain Comparative Example 1. The water swelling degree of the obtained sheet was 64%, and the burst strength when wet was 1.8 kg / cm ² .

[0027]

Comparative Example 2 Bemberg 75 d / f (manufactured by Asahi Kasei Corporation;
Dry strength 2.5 g / d, dry elongation 12%) and polyurethane elastic fiber (Asahi Kasei Kogyo Co., Ltd .: Asahi Kasei Leica) 30 d / 1
A 28GG sheet made of 0f was scoured, dyed, and dried by a conventional method, and treated in the same manner as in Example 1 as Comparative Example 2. The water-swelling degree of the obtained sheet was 82%, and the breaking strength when wet was 1.2 kg / cm ² .

(Evaluation) The knitted fabric of Example 1 was thin and flexible, but the knitted fabric of Comparative Example 2 had a textured surface, and was thick, thick and rough. Further, the knitted fabric of the second embodiment is thin and flexible like the first embodiment,
There were no wrinkles, the eyes were stable, and the appearance was extremely high.

[0029]

[Table 1]

[0030]

According to the present invention, there is provided a stretchable knitted fabric which is rich in stretchability and has very little decrease in strength when wet.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a process chart of treating a knitted fabric with an immersion-type staying-type scouring machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Knitted fabric 2 Guide roll 3 Roller of knitting introduction part 4 Alkaline treatment tank 5 Treatment liquid 6 Hot water tank 7 Neutralization tank 8 Water washing tank

Claims (1)

[Claims] 1. A knitted fabric comprising a multifilament yarn composed of lyocell fiber and a polyurethane-based elastic fiber,
A stretchable knitted fabric characterized in that the knitted fabric has a burst strength when wet of 2.0 kg / cm ² or more.