JP5699503B2 - Knitted fabric and manufacturing method thereof - Google Patents

Description

  The present invention relates to a knitted fabric using acrylic short fibers and a method for producing the same.

In recent years, acrylic fibers, which are fine, have been widely used as inner materials because of their warmth and softness.
For example, Patent Document 1 discloses a molded undergarment that imparts stretchability to a knitted fabric obtained by knitting acrylic fibers and polyurethane elastic fibers to improve the feeling of wearing.

By the way, a knitted fabric imparted with stretchability may be subjected to a dry heat treatment called a set prior to the dyeing process for the purpose of providing dimensional stability.
However, as described in Patent Document 1, in order to set a knitted fabric using polyurethane elastic fibers to have dimensional stability, it is necessary to set the knitted fabric at a high temperature of 180 ° C. or higher. In the knitted fabric using the acrylic fiber, yellowing of the acrylic fiber and a decrease in strength of the knitted fabric have been problems. In particular, in a thin fabric using acrylic fine fibers having a fineness, it is difficult to obtain a knitted fabric having stretchability and satisfying the texture because the fibers tend to shrink and harden and the texture becomes hard.

Thus, as a method for obtaining a stretchable knitted fabric made of acrylic fibers and polyurethane elastic fibers and having a soft texture, for example, Patent Document 2 discloses a method using low-temperature setability polyurethane elastic fibers.
However, as described in Patent Document 2, the heat setting at a low temperature does not necessarily have a sufficient setting property, and there is a problem in dimensional stability such that a cut portion of the knitted fabric is curled.

JP 2002-88515 A JP-A-9-291444

  In view of the above circumstances, an object of the present invention is to provide a knitted fabric having excellent dimensional stability, elasticity, and a soft texture while maintaining strength, and a method for producing the same.

Knitted fabric of the present invention consists of an acrylic fiber yarn and a polyurethane elastic fiber, flexural rigidity 0.020gf · ^cm 2 / ^cm or less, and burst strength is a knitted fabric is not less than 200 kPa, before Symbol acrylic The fiber yarn has a single fiber fineness of 0.3 to 2.2 dtex, a tensile strength of 2.0 cN / dtex or more, and an acrylic short fiber made of an acrylonitrile copolymer containing 94% by mass or more of acrylonitrile units. containing 100 wt%, the ratio of fiber diameter before Symbol acrylic fiber yarn having a fiber diameter and the polyurethane elastic fibers (fiber diameter of the fiber diameter / polyurethane elastic fiber of the acrylic fiber yarn) is at 1.3 to 4.0 There, and the proportion of the acrylic fiber yarns 91 to 99 wt%, the proportion of the polyurethane elastic fiber is Ru 1-9 wt% der.

  Moreover, the manufacturing method of the knitted fabric of this invention is the heat processing temperature of 180-200 degreeC, and the dry heat processing time of 30-90 second for the raw machine formed by knitting the acrylic fiber yarn containing an acrylic short fiber, and a polyurethane elastic fiber. A method for producing a knitted fabric that is preset under conditions, wherein the acrylic short fiber has a single fiber fineness of 0.3 to 2.2 dtex, a tensile strength of 2.0 cN / dtex or more, and a dry heat treatment at 190 ° C. for 60 seconds. The reduction rate of the tensile strength is 20% or less, and the green machine is a ratio of the fiber diameter of the acrylic fiber yarn to the fiber diameter of the polyurethane elastic fiber (fiber diameter of the acrylic fiber yarn / fiber of the polyurethane elastic fiber). (Diameter) is 1.3 to 4.0, the proportion of the acrylic fiber yarn is 91 to 99 mass%, and the proportion of the polyurethane elastic fiber is 1 to 9 mass%.

The knitted fabric of the present invention is excellent in dimensional stability, has stretchability, and has a soft texture while maintaining strength.
Moreover, according to the method for producing a knitted fabric of the present invention, a knitted fabric having excellent dimensional stability, stretchability, and a soft texture while maintaining strength can be obtained.

Hereinafter, the present invention will be described in detail.
[Knitted fabric]
The knitted fabric of the present invention comprises acrylic fiber yarns and polyurethane elastic fibers, has a flexural rigidity of 0.020 gf · cm ² / cm or less, and a burst strength of 200 kPa or more.
When the bending stiffness of the knitted fabric exceeds 0.020 gf · cm ² / cm, the texture of the knitted fabric becomes hard. The bending stiffness of the knitted fabric is preferably 0.015 gf · cm ² / cm or less, and the smaller the value, the better the texture of the knitted fabric, that is, the softer the texture.
The bending stiffness of the knitted fabric can be obtained by measuring the bending stiffness per 1 cm width of the cloth using a pure bending tester “KES-FB2” manufactured by Kato Tech Co., Ltd. as a measuring machine.

On the other hand, when the burst strength of the knitted fabric is less than 200 kPa, the durability of the knitted fabric is lowered and the dimensional stability is lowered. The burst strength of the knitted fabric is preferably 220 kPa or more, and the dimensional stability of the knitted fabric becomes better as the value increases.
The rupture strength of the knitted fabric is a value measured in accordance with the rupture strength A method (Murlen type method) described in JIS L 1018.

  Further, as described above, the knitted fabric of the present invention has a soft texture, but the strength of the knitted fabric can be maintained because the rupture strength of the knitted fabric is 200 kPa or more. That is, the knitted fabric of the present invention has a soft texture while maintaining strength, and has both strength and texture.

Moreover, since the knitted fabric of this invention contains a polyurethane elastic fiber, it has a stretching property.
Here, the acrylic fiber yarn and the polyurethane elastic fiber constituting the knitted fabric will be specifically described.

<Acrylic fiber yarn>
The acrylic fiber yarn used in the present invention preferably contains acrylic short fibers. By including the acrylic short fibers as the acrylic fibers, it is possible to impart both warmth and softness to the knitted fabric by holding the air layer due to the bulkiness.

(Acrylic short fiber)
The acrylic short fiber preferably has a single fiber fineness of 0.3 to 2.2 dtex, more preferably 0.5 to 1.9 dtex. When the single fiber fineness is less than 0.3 dtex, spinning becomes difficult. On the other hand, when the single fiber fineness exceeds 2.2 dtex, it becomes difficult to impart a soft texture to the resulting knitted fabric.
In addition, the single fiber fineness of an acrylic short fiber is a value measured based on JISL1015.

The acrylic short fiber preferably has a tensile strength of 2.0 cN / dtex or more, more preferably 2.2 cN / dtex or more. If the tensile strength is less than 2.0 cN / dtex, the burst strength of the resulting knitted fabric tends to be lowered. The upper limit value of the tensile strength of the acrylic short fiber is not particularly limited, but is preferably 3.0 cN / dtex or less.
In addition, the tensile strength of an acrylic short fiber is a value measured based on JISL1015. Moreover, the tensile strength here is the tensile strength of the acrylic short fiber before the dry heat processing mentioned later.

Moreover, it is preferable that the reduction rate of the tensile strength when acrylic short fiber is dry-heat-treated at 190 ° C. for 60 seconds is 20% or less. If the rate of decrease in the tensile strength is 20% or less, it is possible to suppress a decrease in the tensile strength of the knitted fabric, and it is easy to obtain a knitted fabric having a soft texture while maintaining the strength.
The rate of decrease in tensile strength is determined as follows. That is, the acrylic short fiber is subjected to a dry heat treatment at 190 ° C. for 60 seconds, the tensile strength is measured in accordance with JIS L 1015 before and after the dry heat treatment, and is calculated from the following formula (1). S0 is the tensile strength before the dry heat treatment, and S1 is the tensile strength after the dry heat treatment.
Decrease rate (%) = (S0−S1) / S0 × 100 (1)

The acrylic short fiber is obtained by spinning an acrylonitrile copolymer obtained by copolymerizing acrylonitrile and an unsaturated monomer copolymerizable with the acrylonitrile.
Although it does not specifically limit as an unsaturated monomer, For example, acrylic acid, methacrylic acid and derivatives thereof, vinyl acetate, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, sodium vinylbenzenesulfonate, sodium methacrylsulfonate, acrylamide methyl Examples include sodium sulfonate, sodium vinylbenzene sulfonate, sodium methacryl sulfonate, and sodium acrylamidomethyl sulfonate.

  Here, the acrylonitrile-based copolymer constituting the acrylic short fiber preferably contains 94% by mass or more of acrylonitrile units. When a knitted fabric is manufactured using an acrylonitrile copolymer having an acrylonitrile unit ratio of 94% by mass or more as an acrylic short fiber, the acrylic fiber is pre-set at a dry heat treatment temperature of 180 ° C. or more as described in detail later. It is easy to prevent the yarn from turning yellow and the texture of the knitted fabric from becoming hard.

Moreover, when the ratio of the acrylonitrile unit is 94% by mass or more, it is possible to suppress the burst strength of the resulting knitted fabric from being lowered, and it is easy to obtain a knitted fabric having a soft texture while maintaining the strength. The reason for this is considered as follows.
The decrease rate of the tensile strength of the acrylic short fiber described above is a decrease rate of the tensile strength when dry heat treatment is performed at 190 ° C. for 60 seconds assuming a preset. When an acrylonitrile copolymer having an acrylonitrile unit ratio of 94% by mass or more is used as the acrylic short fiber, the reduction rate of the tensile strength of the acrylic short fiber is likely to be 20% or less. As a result, a decrease in the tensile strength of the knitted fabric can be suppressed, and a knitted fabric having a soft texture can be easily obtained while maintaining the strength.

Here, an example of the manufacturing method of an acrylic short fiber is demonstrated.
First, an acrylonitrile copolymer is dissolved in a solvent to prepare a spinning dope. The concentration of the spinning dope is preferably 15 to 30% by mass. When the concentration of the spinning dope is 15% by mass or more, the tensile strength of the acrylic short fiber is improved. On the other hand, if the concentration of the spinning dope is 30% by mass or less, the spinnability can be maintained satisfactorily, so that the spinning yarn breakage can be suppressed.
Examples of the solvent include dimethylacetamide, dimethyl sulfoxide, dimethylformamide and the like. Among these, dimethylacetamide is preferably used because it hardly deteriorates in properties due to hydrolysis of the solvent and gives good spinnability.

Next, the obtained spinning dope is extruded from a spinneret into a spinning bath in which water and a solvent are mixed, and is solidified and fiberized. The solvent used in the spinning bath is not particularly limited, but it is preferable to use the same solvent as that used in the spinning dope.
The concentration of the spinning bath is preferably 25 to 70% by mass, more preferably 25 to 60% by mass. If the density | concentration of a spinning bath is 25 mass% or more, coagulation | solidification will advance easily and the tensile strength of an acrylic short fiber will improve. If the concentration of the spinning bath is 70% by mass or less, it is possible to suppress the progress of coagulation being too slow, and adhesion between fibers can be prevented.
The temperature of the spinning bath is preferably 30 to 60 ° C, more preferably 30 to 50 ° C. If the temperature of the spinning bath is 30 ° C. or higher, the spinnability can be maintained well, and spinning yarn breakage can be suppressed. On the other hand, if the temperature of the spinning bath is 60 ° C. or lower, it is possible to suppress the progress of solidification too fast, and the tensile strength of the acrylic short fibers is improved.

Next, the yarn that has been solidified in the spinning bath to form a fiber is continuously supplied into a hot water tank in which hot water of 70 ° C. or higher is circulating, and is passed through while removing the solvent. At this time, the yarn is allowed to pass while being drawn (hereinafter abbreviated as “spinning hot drawing”) by changing the rotation speed of the rollers arranged before and after the hot water tank.
The spinning heat draw ratio is preferably 4.0 times or more, more preferably 4.5 times or more. When the spinning heat draw ratio is 4.0 times or more, the tensile strength of the acrylic short fibers is improved. The upper limit of the spinning hot draw ratio is not particularly limited, but is preferably 6 times or less.

Next, the yarn after spinning hot drawing is subjected to oil agent application, drying, crimp application, and steam relaxation treatment by a method usually performed by a wet spinning method to obtain acrylic short fibers.
The single fiber fineness and tensile strength of the acrylic short fiber are determined based on the spinning conditions of the acrylic short fiber, for example, the content of the acrylonitrile unit in the acrylonitrile copolymer, the concentration of the spinning stock solution, the concentration and temperature of the spinning bath, It can be adjusted by adjusting the stay time, spinning heat draw ratio, and the like. Specifically, in order to increase the single fiber fineness, the residence time in the spinning bath may be increased, or the hot drawing ratio for spinning may be increased. In order to reduce the tensile strength, the content of the acrylonitrile unit may be reduced, or the concentration of the spinning dope, the spinning bath concentration and the spinning temperature may be lowered.

The acrylic fiber yarn preferably contains 40 to 100% by mass of the above-mentioned acrylic short fiber, more preferably 70 to 100% by mass, and particularly preferably 100% by mass of acrylic short fiber. When the content of the acrylic short fibers is 40% by mass or more, the heat retaining property and texture (particularly the texture after washing) of the resulting knitted fabric can be favorably maintained.
Examples of fibers other than the acrylic short fibers included in the acrylic fiber yarn include fibers such as polyester, nylon, and regenerated cellulose. If these other fibers are selected and used according to the purpose of use of the knitted fabric, they are used. Good.
The acrylic fiber yarn may be composed only of short fibers, or may be composed of short fibers and long fibers, but is preferably composed only of short fibers from the viewpoint of excellent heat retention. .

<Polyurethane elastic fiber>
The polyurethane elastic fiber plays a role of imparting excellent stretchability to the resulting knitted fabric.
Here, the polyurethane elastic fiber generally refers to a polyurethane elastic fiber that is generally commercially available, and is a long fiber having a tensile elongation of 100% or more, and is 100% by mass of polyurethane elastic fiber or polyurethane elastic fiber. The core yarn uses a long fiber of synthetic fiber such as nylon or polyester as a wound yarn.

In the knitted fabric of the present invention, the ratio of the fiber diameter of the acrylic fiber yarn to the fiber diameter of the polyurethane elastic fiber (the fiber diameter of the acrylic fiber yarn / the fiber diameter of the polyurethane elastic fiber) is 1.3 to 4.0. It is preferable that it is comprised by such a combination, More preferably, it is 2.0-3.0. When the fiber diameter ratio is 1.3 or more, a knitted fabric having sufficient heat retention can be obtained. On the other hand, if the ratio of the fiber diameters is 4.0 or less, the resulting knitted fabric is less likely to have a ground thickness, and the texture is good.
In addition, the fiber diameter of an acrylic fiber thread and a polyurethane elastic fiber can be calculated | required as follows. That is, a cross section of 100 fibers sampled arbitrarily is photographed using a scanning electron microscope “XL series” manufactured by Philips, the fiber diameter of each fiber is measured, and the average value is obtained.

  The knitted fabric of the present invention preferably has a configuration in which the proportion of acrylic fiber yarn is 91 to 99 mass% and the proportion of polyurethane elastic fiber is 1 to 9 mass%. When the proportion of the acrylic fiber yarn is 91% by mass or more and the proportion of the polyurethane elastic fiber is 9% by mass or less, a knitted fabric having sufficient heat retention can be obtained. On the other hand, when the proportion of the acrylic fiber yarn is 99% by mass or less and the proportion of the polyurethane elastic fiber is 1% by mass or more, a knitted fabric having sufficient stretchability is obtained. As for the ratio of each fiber, it is preferable that acrylic fiber yarn is 92-95 mass% and a polyurethane elastic fiber is 5-8 mass%.

As described above, the knitted fabric of the present invention has a soft texture when the bending rigidity is 0.020 gf · cm ² / cm or less. In addition, by making the burst strength 200 kPa or more, the dimensional stability is excellent and the strength can be maintained. Furthermore, since it contains polyurethane elastic fiber, it also has excellent stretchability.

[Production method of knitted fabric]
The method for producing a knitted fabric of the present invention is characterized in that a raw machine formed by knitting acrylic fiber yarns and polyurethane elastic fibers is preset.

<Organization>
The raw machine obtained by knitting acrylic fiber yarn and polyurethane elastic fiber is the ratio of the fiber diameter of acrylic fiber yarn to the fiber diameter of polyurethane elastic fiber (fiber diameter of acrylic fiber yarn / fiber diameter of polyurethane elastic fiber). Is 1.3 to 4.0, preferably 2.0 to 3.0. When the fiber diameter ratio is 1.3 or more, a knitted fabric having sufficient heat retention can be obtained. On the other hand, if the ratio of the fiber diameters is 4.0 or less, the resulting knitted fabric is less likely to have a ground thickness, and the texture is good.
The ratio of the fiber diameter in the raw machine is reflected in the ratio of the fiber diameter in the knitted fabric.

Moreover, as for the raw machine, the ratio of an acrylic fiber yarn is 91-99 mass%, and the ratio of a polyurethane elastic fiber is 1-9 mass%. When the proportion of the acrylic fiber yarn is 91% by mass or more and the proportion of the polyurethane elastic fiber is 9% by mass or less, a knitted fabric having sufficient heat retention can be obtained. On the other hand, when the proportion of the acrylic fiber yarn is 99% by mass or less and the proportion of the polyurethane elastic fiber is 1% by mass or more, a knitted fabric having sufficient stretchability is obtained.
As for the ratio of each fiber, it is preferable that acrylic fiber yarn is 92-95 mass% and a polyurethane elastic fiber is 5-8 mass%.
In addition, the ratio of each fiber in a living machine is reflected in the ratio of each fiber in a knitted fabric.

As a method of knitting the raw machine, a method of knitting acrylic fiber yarn and polyurethane elastic fiber by plating; a method of knitting by single covering yarn using polyurethane elastic fiber as a core yarn and acrylic fiber yarn as a wound yarn; polyurethane A method of knitting by a double covering method in which elastic fibers are core yarns, acrylic fiber yarns are wound, and long fibers such as nylon and polyester or non-stretch yarns such as acrylic short fibers are wound; spinning of acrylic fiber yarns Examples thereof include a method of knitting with a core spun yarn in which a polyurethane elastic fiber is inserted as a core yarn and the polyurethane elastic fiber is arranged at the center of an acrylic fiber yarn.
Among these, in terms of the appearance and cost of the knitted fabric, a method of knitting acrylic fiber yarn and polyurethane elastic fiber by plating, and a core spun yarn in which the polyurethane elastic fiber is arranged at the center of the acrylic fiber yarn. The method is preferred.

<Preset>
The above-mentioned raw machine is preset and becomes a knitted fabric.
Presetting conditions are a dry heat treatment temperature of 180 to 200 ° C. and a dry heat treatment time of 30 to 90 seconds.
When the dry heat treatment temperature is 180 ° C. or higher, a knitted fabric excellent in dimensional stability and shrinkage characteristics can be obtained. Further, the resulting knitted fabric is less likely to have a thickness and has a soft texture. On the other hand, if the dry heat treatment temperature is 200 ° C. or less, it is possible to suppress the acrylic short fibers from changing in physical properties and lowering the tensile strength, and the rupture strength of the resulting knitted fabric is less likely to decrease.
If the dry heat treatment time is 30 seconds or longer, a knitted fabric having excellent dimensional stability and shrinkage characteristics can be obtained. Further, the resulting knitted fabric is less likely to have a thickness and has a soft texture. On the other hand, if the dry heat treatment time is 90 seconds or less, it is possible to suppress the decrease in tensile strength due to the change in physical properties of the acrylic short fibers, and the burst strength of the resulting knitted fabric is unlikely to decrease. The dry heat treatment time is preferably 30 to 60 seconds.

The knitted fabric thus obtained has a flexural rigidity of 0.020 gf · cm ² / cm or less, a burst strength of 200 kPa or more, excellent dimensional stability, and has both a soft texture and strength.

As described above, according to the method for producing a knitted fabric of the present invention, a raw machine in which acrylic fiber yarns including specific acrylic short fibers and polyurethane elastic fibers are knitted at a specific fiber diameter ratio and ratio. Therefore, even if it is preset at a high temperature of 180 ° C. or higher, the texture of the resulting knitted fabric is unlikely to decrease.
Furthermore, according to the method for producing a knitted fabric of the present invention, since the above-described raw machine is used, a knitted fabric having excellent step stability and maintaining strength can be obtained. Furthermore, since a polyurethane elastic fiber is used, a knitted fabric excellent in stretchability can be obtained.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
The measurement method and evaluation method implemented in this example are as follows.

<Measurement of single fiber fineness of acrylic short fibers>
The single fiber fineness of the acrylic short fiber was measured according to JIS L 1015.

<Measurement of tensile strength of acrylic short fiber and rate of decrease in tensile strength>
The tensile strength of the acrylic short fiber was measured according to JIS L 1015. This value was taken as the tensile strength before dry heat treatment (before treatment [S0]).
Moreover, the decreasing rate of tensile strength was calculated | required as follows. That is, the acrylic short fiber was subjected to a dry heat treatment at 190 ° C. for 60 seconds using an electric furnace “Muffle Furnace FO300” manufactured by Yamato Scientific Co., Ltd. The tensile strength of the acrylic short fiber after the dry heat treatment was measured according to JIS L 1015, and this was taken as the tensile strength after the dry heat treatment (after treatment [S1]). And the decreasing rate of tensile strength was computed from following formula (1).
Decrease rate (%) = (S0−S1) / S0 × 100 (1)

<Measurement of fiber diameter>
The fiber diameters of the acrylic fiber yarn and the polyurethane elastic fiber were determined as follows. That is, 100 cross-sections of fibers arbitrarily sampled were photographed using a scanning electron microscope “XL series” manufactured by Philips, the fiber diameter of each fiber was measured, and the average value was obtained.

<Evaluation of spinnability of acrylic short fiber>
The spinnability of acrylic short fibers was evaluated according to the following evaluation criteria.
○: Spinning yarn breakage and adhesion between fibers did not occur, and stable spinning was possible.
X: Spinning yarn breakage or fiber-to-fiber adhesion frequently occurred, and stable spinning was difficult.

<Measurement of bending stiffness>
The bending stiffness of the knitted fabric was measured using a pure bending tester (manufactured by Kato Tech Co., Ltd., product name: KES-FB2) under the condition of maximum curvature ± 2.5 cm ⁻¹ for a sample (20 cm × 1 cm). The bending stiffness is the bending stiffness per 1 cm width of the cloth, and when K is a bending moment M per 1 cm width (gf · cm / cm) and a curvature K (cm ⁻¹ ), K is between 0.5 and 15. The average slope is expressed by dM / dK (gf · cm ² / cm).

<Measurement of burst strength>
The rupture strength of the knitted fabric was measured according to the rupture strength A method (Murlen type method) described in JIS L 1018. The rupture strength of the knitted fabric is an index of the dimensional stability of the knitted fabric. If the rupture strength is 200 kPa or more, the dimensional stability is good.

<Evaluation of texture>
Ten judges are allowed to wear a knitted fabric sewn on a T-shirt, and when it is judged that the feel is soft, it is judged as “good”, and when it is judged to be stiff and hard, it is judged as “bad”. And evaluated.
○: All judges judged as “good”.
X: Among the 10 judges, one or more judges as “bad”.

<Evaluation of heat retention>
Sensory evaluation was performed on the heat retention after 10 judges were put on the knitted fabric sewn on the T-shirt and rested in the sitting position for 1 hour in an environment of temperature 20 ° C and humidity 40% RH. Evaluation was based on criteria.
○: All judges judged “warm”.
X: Among the 10 judges, one or more judges were “cold”.

[Example 1]
<Manufacture of acrylic short fibers>
An acrylonitrile copolymer containing 95% by mass of acrylonitrile units and 5% by mass of vinyl acetate units was dissolved in dimethylacetamide so as to have a concentration of 24% by mass to prepare a spinning dope.
Subsequently, the spinning dope was extruded from a round hole nozzle into a spinning bath filled with an aqueous dimethylacetamide solution, solidified and fiberized. The concentration of the aqueous dimethylacetamide solution in the spinning bath was 56% by mass, the spinning bath temperature was 45 ° C., and the residence time in the spinning bath from the nozzle to the withdrawal from the spinning bath was 0.8 seconds.
The coagulated and fiberized yarn is supplied to a hot water tank and washed, and after drawing so that the spinning hot draw ratio is 4.5 times, the oil is applied and dried by a method usually performed by a wet spinning method. After crimping and steam relaxation treatment, the fibers were cut to obtain acrylic short fibers. There was no problem in the spinnability when spinning the acrylic short fiber, and it was possible to spin stably.
The obtained acrylic short fiber has a single fiber fineness of 0.8 dtex, a tensile strength (before treatment [S0]) of 2.5 cN / dtex, and a tensile strength after dry heat treatment (after treatment [S1]) of 2.4 cN. / Dtex, the rate of decrease in tensile strength was 4%.

<Manufacture of knitted fabric>
1/60 spun yarn was spun from the obtained acrylic short fiber with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100 mass%).
Separately, a monofilament of polyurethane elastic fiber having a single fiber fineness of 22 dtex was prepared.
The ratio of the fiber diameters of these acrylic fiber yarns and polyurethane elastic fibers (fiber diameter of acrylic fiber yarns / fiber diameter of polyurethane elastic fibers) was 2.7.
These fibers are set on a circular knitting machine so that the ratio of acrylic fiber yarns is 92% by mass and the ratio of polyurethane elastic fibers is 8% by mass, and the knitting structure is knitted as a 1: 1 flat knitting to obtain a raw machine. It was.
The resulting green machine was preset under conditions of a dry heat treatment temperature of 180 ° C. and a dry heat treatment time of 60 seconds to obtain a knitted fabric. The electric furnace “Muffle Furnace FO300” manufactured by Yamato Scientific Co., Ltd. was used for the presetting.
The obtained knitted fabric was dyed at 98 ° C. for 90 minutes using a cationic dye, a slow dyeing agent, a leveling agent and the like as a dyeing step. Then, after dehydration and drying, final setting was performed at 140 ° C. for 60 seconds, and sewing was performed on a T-shirt.
Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Example 2]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was spun into 1/64 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100 mass%). Ratio of fiber diameter of acrylic fiber yarn and polyurethane elastic fiber A knitted fabric was obtained in the same manner as in Example 1 except that was changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Example 3]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was spun into a 1/85 spun yarn with a yarn count and used as an acrylic fiber yarn (acrylic short fiber 100% by mass). The ratio of the fiber diameter of the acrylic fiber yarn to the polyurethane elastic fiber A knitted fabric was obtained in the same manner as in Example 1 except that the ratio of acrylic fiber yarn and polyurethane elastic fiber and the presetting conditions were changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Example 4]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was 70% by mass and 1.0 dtex rayon fiber was 30% by mass, and 1/64 spun yarn was spun with a hair count, and this was made into an acrylic fiber yarn (acrylic short fiber 70% by mass). ).
The ratio of the fiber diameter of the obtained acrylic fiber yarn and polyurethane elastic fiber was changed as shown in Table 2, and further dyeing was performed at 98 ° C. for 90 minutes using a cationic dye, a slow dyeing agent, a leveling agent, etc. After that, a knitted fabric was obtained in the same manner as in Example 1 except that the temperature was lowered and the solution was drained and then dyed at 60 ° C. for 90 minutes using a reactive dye, a pH adjuster, or the like. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Example 1]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was spun into 1/60 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100 mass%). Ratio of fiber diameter of acrylic fiber yarn and polyurethane elastic fiber A knitted fabric was obtained in the same manner as in Example 1 except that the ratio of acrylic fiber yarn and polyurethane elastic fiber and the presetting conditions were changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Example 2]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was spun into 1/64 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100 mass%). Ratio of fiber diameter of acrylic fiber yarn and polyurethane elastic fiber A knitted fabric was obtained in the same manner as in Example 1 except that the presetting conditions were changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Examples 3 and 4]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1. However, the spinnability was poor and the fibers were bonded to each other, resulting in defective yarns. Cutting was frequent and stable production was impossible. Therefore, the knitted fabric could not be manufactured.

[Comparative Examples 5 to 7]
Acrylic short fibers were spun in the same manner as in Example 1 except that the spinning conditions were changed as shown in Table 1.
The obtained acrylic short fiber was spun into 1/64 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100 mass%). Ratio of fiber diameter of acrylic fiber yarn and polyurethane elastic fiber A knitted fabric was obtained in the same manner as in Example 1 except that was changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Example 8]
The acrylic short fiber spun in the same manner as in Example 1 was spun into a 1/140 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100% by mass). Acrylic fiber yarn and polyurethane elastic A knitted fabric was obtained in the same manner as in Example 1 except that the fiber diameter ratio, the ratio of the acrylic fiber yarn to the polyurethane elastic fiber, and the presetting conditions were changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Example 9]
A spun acrylic fiber spun in the same manner as in Example 1 was spun into a 1/40 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100% by mass). A monofilament of 11 dtex polyurethane elastic fiber Except that the ratio of the fiber diameter of the acrylic fiber yarn to the polyurethane elastic fiber, the ratio of the acrylic fiber yarn to the polyurethane elastic fiber, and the presetting conditions were changed as shown in Table 2. And got a knitted fabric. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Example 10]
The acrylic short fiber spun in the same manner as in Example 1 was spun into a 1/140 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100% by mass). A 55-dtex polyurethane elastic fiber monofilament Except that the ratio of the fiber diameter of the acrylic fiber yarn to the polyurethane elastic fiber, the ratio of the acrylic fiber yarn to the polyurethane elastic fiber, and the presetting conditions were changed as shown in Table 2. And got a knitted fabric. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

[Comparative Examples 11-14]
The acrylic short fiber spun in the same manner as in Example 1 was spun into a 1/64 spun yarn with a hair count, and this was used as an acrylic fiber yarn (acrylic short fiber 100% by mass). A knitted fabric was obtained in the same manner as in Example 1 except that the fiber diameter ratio and the presetting conditions were changed as shown in Table 2. Each evaluation was performed about the obtained knitted fabric. The results are shown in Table 2.

As is clear from Table 1, the knitted fabric obtained in each example had a flexural rigidity of 0.020 gf · cm ² / cm or less and a good texture. Moreover, it was suggested that the burst strength is 200 kPa or more, the dimensional stability is excellent, and the strength is maintained. Furthermore, the heat retention was also good. Moreover, since the knitted fabric obtained in each Example contained a polyurethane elastic fiber, it also had excellent stretchability.

On the other hand, the knitted fabric of Comparative Example 1 using acrylic short fibers having a single fiber fineness of 4.4 dtex had a bending stiffness of 0.032 gf · cm ² / cm and a poor texture.
The knitted fabric of Comparative Example 2 using acrylic short fibers having a tensile strength reduction rate of 25% had a burst strength of 150 kPa, and sufficient dimensional stability could not be obtained.
The knitted fabric of Comparative Example 5 using acrylic short fibers having a tensile strength of 1.8 cN / dtex had a burst strength of 175 kPa, and sufficient dimensional stability could not be obtained.
The knitted fabric of Comparative Example 6 using acrylic short fibers having a tensile strength of 1.8 cN / dtex and a tensile strength reduction rate of 28% has a burst strength of 160 kPa and is sufficiently dimensionally stable. Sex was not obtained.
The knitted fabric of Comparative Example 7 using acrylic short fibers having a tensile strength of 1.9 cN / dtex and a reduction rate of tensile strength of 21% has a burst strength of 172 kPa and is sufficiently dimensionally stable. Sex was not obtained.
The knitted fabric of Comparative Example 8 knitted so that the proportion of the acrylic fiber yarn is 45% and the proportion of the polyurethane elastic fiber is 55% by mass has a burst strength of 180 kPa, and sufficient dimensional stability cannot be obtained. It was. Moreover, the heat retention was also bad.
The knitted fabric of Comparative Example 9 in which the ratio of the fiber diameter of the acrylic fiber yarn to the polyurethane elastic fiber was 4.7 had a flexural rigidity of 0.030 gf · cm ² / cm and poor texture.
The knitted fabric of Comparative Example 10 in which the ratio of the fiber diameter of the acrylic fiber yarn to the polyurethane elastic fiber was 1.1 had a burst strength of 182 kPa, and sufficient dimensional stability could not be obtained. Moreover, the heat retention was also bad.
The knitted fabric of Comparative Example 11 preset at a dry heat treatment temperature of 140 ° C. had a bending stiffness of 0.029 gf · cm ² / cm and a poor texture.
The knitted fabric of Comparative Example 12 preset at a dry heat treatment temperature of 220 ° C. had a burst strength of 164 kPa, and sufficient dimensional stability could not be obtained.
The knitted fabric of Comparative Example 13, which was preset with a dry heat treatment time of 15 seconds, had a bending stiffness of 0.030 gf · cm ² / cm and a poor texture.
The knitted fabric of Comparative Example 14 preset with a dry heat treatment time of 180 seconds had a burst strength of 179 kPa, and sufficient dimensional stability could not be obtained.

Claims (2)

A knitted fabric comprising acrylic fiber yarns and polyurethane elastic fibers, having a flexural rigidity of 0.020 gf · cm ² / cm or less and a bursting strength of 200 kPa or more ,
The acrylic fiber yarn is an acrylic short fiber composed of an acrylonitrile-based copolymer having a single fiber fineness of 0.3 to 2.2 dtex, a tensile strength of 2.0 cN / dtex or more, and 94% by mass or more of acrylonitrile units. Containing 40 to 100% by mass,
The ratio of the fiber diameter of the acrylic fiber thread to the fiber diameter of the polyurethane elastic fiber (the fiber diameter of the acrylic fiber thread / the fiber diameter of the polyurethane elastic fiber) is 1.3 to 4.0, and the acrylic fiber thread Is a knitted fabric in which the proportion of the elastic elastic fiber is 91 to 99 mass% and the proportion of the polyurethane elastic fiber is 1 to 9 mass%. This is a method for producing a knitted fabric in which a raw machine formed by knitting acrylic fiber yarns including short acrylic fibers and polyurethane elastic fibers is preset under conditions of a dry heat treatment temperature of 180 to 200 ° C. and a dry heat treatment time of 30 to 90 seconds. And
The acrylic short fiber has a single fiber fineness of 0.3 to 2.2 dtex, a tensile strength of 2.0 cN / dtex or more, and a decrease rate of the tensile strength when dry-heat-treated at 190 ° C. for 60 seconds is 20% or less. Yes,
The raw machine has a ratio of fiber diameter of acrylic fiber yarn to fiber diameter of polyurethane elastic fiber (fiber diameter of acrylic fiber yarn / fiber diameter of polyurethane elastic fiber) of 1.3 to 4.0, and acrylic The manufacturing method of the knitted fabric whose ratio of a fiber yarn is 91-99 mass% and whose ratio of a polyurethane elastic fiber is 1-9 mass%.