JP4553703B2 - Woven knitted fabric and method for producing the woven and knitted fabric - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a polylactic acid processed yarn that becomes a fabric having excellent soft feeling and deep dyeability by being knitted and woven and dyed, and a method for producing the same, and a woven / knitted fabric.

  Conventionally, false twisted yarns using synthetic fiber multifilaments, especially polyethylene terephthalate (PET), have been widely used from the viewpoint of versatility.

  However, as environmental problems have been raised, there is an increasing demand for using biolactic acid derived from plants and biodegradable as an alternative to petroleum-derived PET. Proposal of processed yarn has been made. However, since polylactic acid has a low melting point and heat treatment at a high temperature is difficult like PET, the hot water shrinkage rate is high, and as a result, the texture of the woven or knitted fabric becomes hard.

    For example, Patent Document 1 is made of an aliphatic polyester having a melting point of 130 ° C. or higher, subjected to false twisting, has a boiling water shrinkage of 6% or more and 30% or less, and a stretch / restore rate (CR) of 5 % Of aliphatic polyester processed yarn has been proposed.

  This processed yarn improves the swelling, resilience and stretchability of woven and knitted fabrics by imparting high shrinkage and crimp to aliphatic polyester yarns. Polylactic acid tends to have a harder texture than PET. This tendency is promoted by high shrinkage, and the crimping is applied by the frictional false twisting method such as the normal spindle method, belt nip method, and triaxial friction. A unique feeling of rustling and glare has occurred, and it has not yet been possible to obtain a high-quality woven or knitted fabric.

    Patent Document 2 discloses false twisted yarn made of aliphatic polyester fiber, having a cross-section change rate of 1.5 or less, an expansion / contraction recovery rate satisfying a specific formula, and a hot water shrinkage rate of 5 to 5. An aliphatic polyester false twist yarn having an excellent gloss of 15% has been proposed.

    This false twisted yarn has a relatively small cross-sectional deformation of 1.5 or less, so that the above-mentioned glare (glitter) is improved. However, since a triaxial twister or a belt nip twister is used, the crimp becomes high, and the false twisted yarn The unique feeling of roughness cannot be improved, and a high-quality woven or knitted fabric has not been obtained.

On the other hand, Patent Document 3 discloses a polyester crimped yarn composed of a filament having a concavo-convex shape or micropores on the surface, and a birefringence (Δn) of 70 × 10 ⁻³ to 120 × 10 ⁻³ , A deep dyeing specially processed yarn having an elongation of 20 to 50%, a crimping rate of 20% or less, and a dyeing L value of 11.5 or less with a black dye of a fabric has been proposed.

Although this processed yarn has unevenness or fine pores on the surface, deep dyeability can be obtained, but it is not biodegradable because it uses a highly oriented PET highly oriented undrawn yarn, and the elongation is reduced. Therefore, stretching is performed after swirling and heat treatment (hereinafter sometimes referred to as swirling). For this reason, the deep dyeability is lowered, and it has been necessary to improve the deep dyeability by using a filament having an uneven shape or fine pores on the surface, or by providing a loop or sagging on the surface of the yarn. In addition, there is a problem that the hot water shrinkage rate is increased by stretching, and the texture of the woven or knitted fabric becomes hard.
JP 2002-155437 A Japanese Patent No. 3463597 JP-A-8-1003006

The present invention solves the above-mentioned conventional problems, and weaves and knits that become a fabric having a high texture with excellent soft feeling and deep dyeability and biodegradability by knitting and weaving and dyeing the same. Providing a manufacturing method is a technical problem.

    As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have preferably reduced the hot water shrinkage rate and crimp rate by preferably turning the polylactic acid multifilament, and preferably torque. The inventors have found that a polylactic acid processed yarn having a high texture with excellent soft feeling and deep dyeability and having biodegradability can be obtained by setting it within a specific range, and the present invention has been achieved.

That is, the gist of the present invention is as follows.
(1) A dyed L ^* value using at least a part of a processed yarn made of polylactic acid multifilament having a hot water shrinkage rate of 7% or less, a crimp rate of 20% or less, and an elongation of 50% or less. Is a woven or knitted fabric characterized by having 12.0 or less.
(2) The knitted or knitted fabric according to (1), wherein the torque of the processed yarn is 40 pieces / m or more and 100 pieces / m or less.
(3) The woven or knitted fabric according to (1) or (2), wherein the processed yarn is obtained by swirling with liquid and heat treatment.
(4) Using a polylactic acid multifilament having an elongation of 100% or less as a supply yarn, the supply yarn is swirled with a fluid under the conditions of a twist coefficient of 3000 to 17000 and a turning tension of 0.04 to 0.09 g / dtex. Te, a heating treatment was performed in the upstream side while propagating to the upstream side of the feed yarn twist, the polylactic acid subjected to false twisting multifilament, hot water shrinkage is not more than 7%, the percentage of crimp 20% or less, and to elongation, such as 50% or less of the yarn, weaving knitting with the yarn Thereafter, by staining, characterized in that the dyeing L * value of 12.0 or less Manufacturing method of woven or knitted fabric .
(5) The method for producing a knitted or knitted fabric according to (4), wherein the torque of the processed yarn is 40 pieces / m or more and 100 pieces / m or less.

Since the woven or knitted fabric of the present invention uses a specific polylactic acid processed yarn for at least a part thereof, it has a biodegradability by knitting and weaving and dyeing. A high-quality woven or knitted fabric having a smooth touch and a glossy feeling with a deep depth can be obtained .

  Hereinafter, the present invention will be described in detail.

First, as polylactic acid forming the polylactic acid processed yarn used in the woven or knitted fabric of the present invention, poly L-lactic acid, poly D-lactic acid, a copolymer of L-lactic acid and D-lactic acid, L-lactic acid and hydroxy Examples thereof include a polymer selected from the group consisting of a copolymer with carboxylic acid, a copolymer with D-lactic acid and hydroxycarboxylic acid, and a copolymer with L-lactic acid, D-lactic acid and hydroxycarboxylic acid.

  The melting points of poly-L-lactic acid and poly-D-lactic acid, which are homopolymers of lactic acid, are about 180 ° C., respectively, but when the above copolymer is used as the lactic acid polymer, mechanical strength, melting point, etc. are taken into consideration. Thus, it is preferable to determine the copolymerization ratio of the copolymer component. For example, in the case of a copolymer of L-lactic acid and D-lactic acid, one of L-lactic acid and D-lactic acid is 90 mol% or more and less than 100 mol%, and the other exceeds 0 mol% and 10 In the case of a copolymer of L-lactic acid or D-lactic acid and hydroxycarboxylic acid, for example, the lactic acid is 90 mol% or more and less than 100 mol%. The hydroxycarboxylic acid is preferably in the range of more than 0 mol% and 10 mol% or less.

    Examples of the hydroxycarboxylic acid in the copolymer of lactic acid and hydroxycarboxylic acid include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, and hydroxyoctanoic acid. Among these, hydroxycaproic acid or glycolic acid is particularly preferable because of its low cost.

The polylactic acid processed yarn used for the woven or knitted fabric of the present invention is required to have a hot water shrinkage rate of 7% or less and a crimp rate of 20% or less. Further, the hot water shrinkage rate is more preferably 0 to 5%, and the crimping rate is preferably 15% or less, particularly preferably 0 to 10%. By reducing the hot water shrinkage rate, shrinkage in subsequent processes such as dyeing is reduced, and in addition to suppressing the hardening of the texture, the false twist peculiar to false twisted yarn due to the low crimp rate and the feeling of glare In combination with the non-conventional polylactic acid false-twisted yarn, the texture is soft and smooth, elegant touch with no roughness, and the texture is mild and deep. A knitted fabric can be obtained. If the hot-water shrinkage rate exceeds 7%, it is not preferable because the texture and glare feeling peculiar to false twisted yarn are expressed. The lower limit of the hot water shrinkage rate is not particularly limited, but care must be taken because the knitted or knitted fabric becomes loose and becomes unsatisfactory when it becomes less than 0%, that is, when it expands with heat. is there.

Further, the elongation of the polylactic acid processed yarn used for the woven or knitted fabric of the present invention needs to be 50% or less, and more preferably 15 to 40%. If the elongation exceeds 50%, the polylactic acid-processed yarn is stretched in a process such as twisted yarn or knitting and weaving, so that the quality is lowered and the deep dyeability is also lowered.

    Furthermore, the torque of the processed yarn is preferably 40 pieces / m or more and 100 pieces / m or less, particularly 50 to 80 pieces / m. By having a torque in this range, heat is applied in the post-process such as dyeing, and the polylactic acid processed yarn twists and scatters and contracts, causing irregular reflection of light on the surface of the woven or knitted fabric, and deepening the woven or knitted fabric. A certain color can be imparted, the yarn is twisted, and natural drape is also produced, so that a woven or knitted fabric with higher texture can be obtained. When the torque is less than 40 pcs / m, twisting and variation are unlikely to occur, so that the irregular reflection is difficult to occur, and it is difficult to express deep coloration, and natural draping property is also difficult to occur. It may be the same as the knitted fabric. On the other hand, when the torque exceeds 100 pieces / m, the handling becomes somewhat difficult due to snare or the like, and the process passability may be deteriorated.

Furthermore, the polylactic acid processed yarn used for the woven or knitted fabric of the present invention is preferably obtained by swirling with fluid and heat treatment, that is, swirling with fluid. In the swirling process using fluid, a false twist can be applied to the yarn with a low tension, and a processed thread with reduced cross-section deformation and orientation can be obtained. Therefore, the characteristics of the polylactic acid-based processed thread can be effectively expressed. It becomes possible. In addition, the twisting and untwisting points of the yarn are not fixed like false twisting pins, disks, and belts, so the twisting and untwisting functions are not uniform, and the polylactic acid processed yarn has a natural feeling. It can be applied, and a woven or knitted fabric with higher texture can be obtained.

Next, the manufacturing method of the polylactic acid processed thread | yarn used for the woven / knitted fabric of this invention is demonstrated.

The method for producing a polylactic acid processed yarn used for the woven or knitted fabric of the present invention is to perform false twisting on the polylactic acid multifilament by subjecting the polylactic acid multifilament to a supply yarn and swirling with a fluid and heat treatment. The processed yarn has a shrinkage rate of 7% or less, a crimp rate of 20% or less, and an elongation of 50% or less.

Although the fluid used by this invention is not specifically limited, Compressed air is preferable from versatility and productivity. Moreover, it is preferable to use a swirl nozzle from the viewpoint of workability and handling, and the swirl process is more useful as the swirl capability is higher because it can cope with various conditions. However, if the number of swirling is too high, the twisting action of the yarn by twisting becomes strong, the structure inside the fiber changes, the orientation advances, and it becomes close to a normal false twisted yarn, and it is not possible to obtain a deep dyeing property and since the percentage of crimp coarseness feeling and glare is caused by more than 20%, it is necessary to set the twist coefficient expressed by the product of the square root of the denier and number of false twist to 3 000-17000.

In the present invention, in order to obtain a polylactic acid processed yarn having a hot water shrinkage rate of 7% or less, it is necessary to set the swirling tension within the range of 0.04 to 0.09 g / dtex. The heater temperature depends on the processing speed, but is usually set to 80 ° C., more preferably 90 to 140 ° C. When turning the tension is less than 0.04 g / dtex, low tension by turning is not stable, it plaques in the longitudinal direction of the yarn is damaged the quality of the woven or knitted fabric occurs. If it exceeds 0.09 g / dtex, with the orientation proceeds applied load on the yarn, it becomes close for deep dyeing property can not be obtained in the usual temporary twisting and coarseness feeling and glare is arising.

Further, in order to make the elongation 50% or less, for example, the elongation of the polylactic acid multifilament to be supplied needs to be 100% or less, preferably 90% or less, more preferably 20 to 80% . . Also, it can be achieved by reducing the overfeed rate during the heat treatment described later.

    Furthermore, in the present invention, in order to set the torque of the processed yarn to 40 pcs / m or more and 100 pcs / m or less, it is preferable to perform heat treatment after performing false twisting by swirling and heat treatment. At this time, the heat treatment is preferably performed in a constant length or overfeed state, and the heater temperature is preferably performed at a temperature equal to or higher than the temperature at the time of turning. By performing such heat treatment, the hot water shrinkage rate and torque can be reduced, but when the overfeed rate becomes excessively large, the elongation of the processed yarn becomes excessively large and the quality of the woven or knitted fabric decreases. Therefore, the upper limit is preferably about 20%. Also, heat treatment in the stretched state is not preferable because the hot water shrinkage ratio is increased and the dyeability is also lowered. Further, a higher heater temperature is better in terms of setability, but attention should be paid to fusion. Further, it is not preferable that the heater temperature is lower than the temperature at the time of turning because the setting tends to be insufficient.

    As the polylactic acid multifilament to be supplied, either a drawn yarn or a highly oriented undrawn yarn can be used. However, a highly oriented undrawn yarn has a low orientation and is easy to darken. Used. However, if the elongation is too high, it becomes difficult to reduce the elongation of the polylactic acid processed yarn to 50% or less. Therefore, the elongation of the highly oriented undrawn yarn is preferably 50 to 100%.

Next, the woven or knitted fabric of the present invention uses the above-mentioned polylactic acid processed yarn at least in part, and the dyeing L ^* value is preferably as low as possible to express the deep dyeing effect. Specifically, it must be 12.0 or less , and more preferably 11.0 or less. When the dyeing L ^* value exceeds 12.0, the deep dyeing effect of the polylactic acid processed yarn used for the woven or knitted fabric of the present invention cannot be expressed in the fabric.

    The polylactic acid processed yarn in the woven or knitted fabric may be used for at least a part of at least one of warp and weft, and the use ratio is not particularly limited, but the features of the polylactic acid processed yarn of the present invention are the appearance and texture. In order to express effectively in dyeability etc., 30 mass% or more is preferable, and 50-100 mass% is more preferable.

Next, an embodiment of a method for producing a polylactic acid processed yarn used for the woven or knitted fabric of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic process diagram showing one embodiment of a method for producing a polylactic acid processed yarn used for the woven or knitted fabric of the present invention. In FIG. 1, a supply yarn 1, which is a polylactic acid multifilament, is pulled out from a spool 2, passes through a guide 3, and is supplied between the feed roller 4, the first heater 5, the fluid swirl nozzle 6, and the first delivery roller 7. The false twisting process is performed by performing a heat treatment on the upstream side while turning to 1 and propagating the ground to the upstream side of the supply yarn 1 .

  Next, the yarn subjected to false twisting is heat-treated by the first delivery roller 7, the second heater 8, and the second delivery roller 9 to become polylactic acid processed yarn, and is wound around the package 10.

The polylactic acid processed yarn used for the woven or knitted fabric of the present invention reduces the shrinkage in the subsequent process such as dyeing by reducing the hot water shrinkage rate, and in addition to suppressing the hardening of the texture, the crimp rate Compared with conventional polylactic acid false twisted yarn, it has a soft touch and an elegant touch with no roughness, and a mild and deep gloss feeling, combined with the lack of texture and glare unique to false twisted yarn due to its low Thus, it becomes possible to obtain a high-quality woven or knitted fabric that has never been obtained.

    Also, if the torque is 40 pcs / m or more and 100 pcs / m or less, heat will be applied in the subsequent process such as dyeing, and the polylactic acid processed yarn will twist and scatter and shrink. The diffused reflection of the knitted fabric can give a deep color to the woven or knitted fabric, and the yarn is twisted and natural draping is also produced, so that the woven or knitted fabric with higher texture can be obtained. .

Next, the present invention will be specifically described with reference to examples. In addition, each physical-property value in an Example is measured with the following method.
(1) Hot water shrinkage (%)
Measured according to JIS-L-1013.
(2) Crimp rate (%)
Double the yarn that has been cut five times with a measuring machine, hang it on a stand under a load of 1/6803 (cN / dtex) (corresponding to 1/6000 (g / d)), and leave it for 30 minutes While maintaining this state, it is placed in boiling water and left for 30 minutes. Then, it is air-dried for 30 minutes, and a length (a) is measured by applying a load of 1/567 (cN / dtex) (corresponding to 1/500 (g / d)). Next, the load is removed, the length (b) is measured by applying a load of 1/23 (cN / dtex) (corresponding to 1/20 (g / d)), and the crimp rate is obtained by the following equation. .
Crimp rate (%) = {(ba) / b} × 100
(3) Elongation (%)
Measured according to JIS-L-1013.
(4) Torque (pieces / m)
The sample was suspended in a U shape, and fixed to each upper end by applying a load of 1/34 (cN / dtex) (corresponding to 1/30 (g / d)), and then formed into a U shape. A load of 1/340 (cN / dtex) (corresponding to 1/300 (g / d)) is applied to the lower end of the sample, and the number of twists per meter when the sample stops turning is displayed.

(5) Dyeing L ^* value The fabric is dyed with the following dyeing prescription.
・ Scouring Scouring Agent: Sunmall FL (manufactured by Nikka Chemical Co., Ltd.) 1g / l
Temperature x time: 70 ° C x 20 minutes ・ Dyeing Disperse dye: Cibacet Black EL-FGL (Cibacet Specialty Chemicals) 15% omf
Auxiliary agent: Nikka Sun Salt SN-130 (manufactured by Nikka Chemical) 0.5g / l
Acetic acid: 0.2ml / l
Temperature x time: 110 ° C x 30 minutes Bath ratio: 1:50
・ Reduction cleaning Reduction cleaning agent: Soda ash 5g / l
Hydrosulfite 1g / l
Sun Mall FL 1g / l
Temperature × Time: 70 ° C. × 20 minutes The reflectance of the fabric dyed with the above dyeing prescription was measured with a Macbeth MS-2020 type spectrophotometer, and the value obtained from the CIE Lab color difference equation was obtained as a concentration index. This is the staining L ^* value, and the smaller the value, the deeper the color.

(6) Soft feeling of fabric, feeling of roughness, feeling of glare Select 10 panelists consisting of weaving engineers and dyeing engineers, and perform the following two-stage evaluation by visual and touch sensory tests.
Soft feeling ○: Existence ×: No sensation and glare sensation ○: None ×: Existence

(Examples 1 and 2)
A polylactic acid (L-lactic acid unit: 98.2 mol%, D-lactic acid unit: 1.8 mol%) containing L-lactic acid as a main component and having a number average molecular weight of 140,000 was used using a biaxial extruder. After melting and kneading at a temperature of 205 to 225 ° C. for about 10 minutes, a chip was produced by extrusion cutting into water in a strand shape.
Next, this chip was used for melt spinning at a spinning temperature of 220 ° C. and a spinning speed of 3000 m / min to obtain 110 dtex 36 filaments of polylactic acid highly oriented undrawn yarn (elongation: 73.6%).
This yarn was used as a supply yarn and processed under the conditions shown in Table 1 according to the process shown in FIG.
Using the resulting polylactic acid processed yarn for warp and weft, weaving a plain fabric with a warp density of 90 / 2.54 cm and a weft density of 80 / 2.54 cm in a water jet loom, dyeing according to the above formulation, finishing Processing was performed.

  Table 1 shows the processing conditions and the evaluation results of the obtained polylactic acid processed yarn and the woven fabric.

As is apparent from Table 1, the fabrics obtained in Example 1 and Example 2 do not feel glare or roughness, are very soft and draped, and use conventional polylactic acid false twist yarns. It was of a completely different high quality. In particular, the processed yarn obtained in Example 2 had a low torque and was very easy to handle. Further, the dyeing L ^* values were 9.9 and 9.8, respectively, and the dyeing property was also excellent.

(Examples 3 and 4)
The polylactic acid highly oriented undrawn yarn obtained in Example 1 was drawn to obtain a polylactic acid drawn yarn of 84 dtex 36 filaments (elongation 29.8%).
Next, using this as a supply yarn, processing was carried out under the conditions shown in Table 1 according to the steps shown in FIG.
Using the obtained polylactic acid processed yarn for warp and weft, weaving a plain fabric with a warp density of 94 / 2.54 cm and a weft density of 84 / 2.54 cm in a water jet loom, and dyeing in the same manner as in Example 1. And finished.

As is apparent from Table 1, the fabrics obtained in Examples 3 and 4 do not feel glare or roughness, are very soft and draped, and use conventional polylactic acid false twist yarns. It was of a completely different high quality. In particular, the processed yarn obtained in Example 4 had a low torque and was very easy to handle. Further, the dyeing L ^* values were 10.6 and 10.5, respectively, and the dyeing property was excellent.

(Comparative Example 1)
Using the 110 dtex 36 filament polylactic acid highly oriented undrawn yarn obtained in Example 1 as a supply yarn, using a spindle pin type twisting device instead of the swivel nozzle 6 in FIG. False twisting was performed to obtain a processed yarn of 88 dtex 36 filaments. In this method, the yarn breakage occurred when the processing tension was lowered, and therefore, the machining was performed with the minimum tension that does not cause the yarn breakage.
Using the obtained comparative processed yarn for warp and weft, weaving a plain woven fabric with a warp density of 96 yarns / 2.54 cm and a weft density of 85 yarns / 2.54 cm in a water jet loom. It was dyed and finished.

As is apparent from Table 1, the obtained woven fabric has bulkiness and stretchability, but has a feeling of roughness and glare, and also has a high hot water shrinkage ratio, and has a hard texture and a high texture. It was not a textured fabric. Further, the dyeing L ^* value was 13.6, and the dyeability was poor.

It is a schematic process drawing which shows one embodiment of the manufacturing method of the polylactic acid processed yarn of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply yarn 2 Spool 3 Guide 4 Feed roller 5 1st heater 6 Fluid swirl nozzle 7 1st delivery roller 8 2nd heater 9 2nd delivery roller
10 packages

Claims (5)

A processed yarn made of polylactic acid multifilament having a hot water shrinkage rate of 7% or less, a crimp rate of 20% or less and an elongation of 50% or less is used at least in part, and the dyeing L ^* value is 12.0. A woven or knitted fabric characterized by: The woven or knitted fabric according to claim 1, wherein the torque of the processed yarn is 40 pieces / m or more and 100 pieces / m or less. The woven or knitted fabric according to claim 1 or 2, wherein the processed yarn is obtained by swirling with a fluid and heat treatment. Using a polylactic acid multifilament having an elongation of 100% or less as a supply yarn, the supply yarn is swirled with a fluid under the conditions of a twist coefficient of 3000 to 17000 and a swirling tension of 0.04 to 0.09 g / dtex, and twisted. the by performing heat treatment in the upstream side while propagating to the upstream side of the feed yarn is subjected to false twisting to the polylactic acid multifilament, hot water shrinkage is not more than 7%, percentage crimp is 20% or less and to elongation, such as 50% or less of the yarn, weaving knitting using the yarn Thereafter, by staining, the woven or knitted fabric, which comprises dyeing L ^* value of 12.0 or less Production method. The method for producing a woven or knitted fabric according to claim 4, wherein the torque of the processed yarn is 40 pieces / m or more and 100 pieces / m or less.