JP5148903B2 - Polyester false twist yarn and knitted fabric for patch made using the same - Google Patents

Description

  The present invention relates to a polyester false twist yarn and a knitted fabric for a patch made using the same.

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

  However, since PET is derived from petroleum and is difficult to be decomposed in nature even if it is discarded, it consumes a lot of energy in its production and disposal, and has a large impact on the environment. In addition, there is a problem of exhaustion of fossil fuels. Close up.

  In recent years, in order to solve this environmental problem, development of fibers derived from plant-derived biodegradable aliphatic polyesters, especially polylactic acid, has been promoted, and the use of false twisted yarns using these is also expanding. is there.

  However, polylactic acid false twisted yarn is difficult to falsely twist at high temperatures due to its characteristics, and requires low temperature false twist as compared with PET false twisted yarn. There was a problem.

In order to solve this problem, Patent Document 1 includes a filament in which an aliphatic polyester is disposed in a core portion and a high-melting crystalline polyester core-sheath composite fiber is disposed in a sheath portion. A crimped yarn satisfying the characteristics and excellent in heat resistance is disclosed. This crimped yarn has excellent heat resistance, wear resistance and bulkiness, and is improved in terms of stretchability as compared with conventional polylactic acid false twisted yarn.
JP 2005-232627 A

  However, the use of the crimped yarn is limited to general clothing, and there remains a problem that it cannot be used for special purposes. That is, the crimped yarn has a disadvantage that it is not suitable for use in a fabric that is thin, stretches with low stress, and requires a restoring force, such as a knitted fabric for a patch.

  The present invention eliminates the disadvantages of the prior art as described above, and can be used for a knitted fabric that is thin, stretches with low stress, and requires a restoring force, and a low-environment polyester false twist yarn, It is a technical subject to provide a patch knitted fabric using a polyester false twist yarn.

  As a result of diligent studies to solve the above problems, the present inventors have found that a false twisted yarn comprising a polyester core-sheath type composite filament having a core portion made of polylactic acid and a sheath portion made of aromatic polyester, and the false twist yarn, The present inventors have reached the present invention by obtaining the knowledge that the problem can be solved by making the knitted fabric used have specific physical properties.

That is, the gist of the present invention is as follows.
(1) core is polylactic acid, the sheath portion is composed of an aromatic polyester, Ri Do a polyester core-sheath type composite filament core / sheath weight ratio is 20/80 to 70/30, and, fineness 30 a knitted fabric 70dtex and the stretch recovery ratio is using 35-45% der Lupo Riesuteru temporary twist yarn, basis weight and is a 80~140g / ^{m 2,} constant elongation during stretching force is below 10N in the wale direction A knitted fabric for a patch, which is 6N or less in the course direction, and further has an elastic modulus of elasticity of 80% or more in both the wale direction and the course direction.

  The polyester false twisted yarn of the present invention is excellent in extensibility / restorability since it has a small environmental load and has a predetermined core / sheath mass ratio, fineness, and expansion / contraction recovery rate. Therefore, the polyester false twisted yarn of the present invention can be used not only for general clothing but also for special applications, and can be suitably used for a patch by making a knitted fabric satisfying specific physical properties.

  Hereinafter, the present invention will be described in detail.

  The polyester false twisted yarn of the present invention is a false twisted yarn comprising a polyester core-sheath type composite filament having a core part made of polylactic acid and a sheath part made of aromatic polyester. The false twisted yarn of the present invention is suitable as a yarn constituting a woven or knitted fabric, and is suitable not only for general clothing but also for special uses such as a knitted fabric for a patch. In addition, a patch is an external preparation formed by applying or impregnating a drug to a knitted fabric. The patch is applied to an affected area and absorbs a drug component from the skin to treat inflammation.

  Examples of polylactic acid constituting the core of the polyester core-sheath composite filament include poly L-lactic acid, poly D-lactic acid, a copolymer of L-lactic acid and D-lactic acid, and L-lactic acid and hydroxycarboxylic acid. Examples thereof include a polymer selected from the group consisting of a copolymer, a copolymer of D-lactic acid and hydroxycarboxylic acid, and a copolymer of 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 using the above copolymer as a lactic acid-based 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 is more than 0 mol% and more than 10 mol%. In the case of a copolymer of L-lactic acid or D-lactic acid and hydroxycarboxylic acid, for example, 90 mol% or more and less than 100 mol% of the lactic acid is a copolymer component. 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.

  On the other hand, examples of the aromatic polyester constituting the sheath of the polyester core-sheath composite filament include polyesters mainly composed of polyalkylene terephthalate such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate. This aromatic polyester includes aromatic dicarboxylic acids such as isophthalic acid and 5-sodium sulfoisophthalic acid, aliphatic diols such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol, Glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, and other hydroxycarboxylic acids may be copolymerized.

  In addition, the polylactic acid and the aromatic polyester have a matting agent such as titanium oxide, an antistatic agent, an ultraviolet absorber, a pigment, a flame retardant, an antibacterial agent, an antibacterial agent, and the like within a range not to impair the essential characteristics. Components such as an odorant and a conductivity imparting agent may be contained.

  The polyester core-sheath type composite filament in the present invention has a core part made of polylactic acid and a sheath part made of aromatic polyester as described above, and the core / sheath mass ratio at that time is 20/80. It must be ~ 70/30. When the core / sheath mass ratio is within this range, a false twisted yarn with high crimp and excellent fastness can be obtained. If the core / sheath mass ratio is less than 20/80 and the mass ratio of the core is low, the content of polylactic acid is reduced, which increases the load on the environment. On the other hand, if the core / sheath mass ratio exceeds 70/30 and the mass ratio of the core portion is high, the strength dependency on the core portion increases, so the strength of the false twisted yarn decreases and the expansion / contraction recovery rate also decreases. If it does so, since the intensity | strength of a knitted fabric will fall and the elongation power at the time of fixed elongation will increase, it will become difficult to use for a patch. Furthermore, a crack may occur in the sheath during false twisting.

  The polyester false twisted yarn of the present invention is composed of such a polyester core-sheath type composite filament, and it is necessary that the fineness and expansion / contraction recovery rate are in a specific range.

  First, the fineness needs to be 30 to 70 dtex. The fineness in this case refers to the total fineness. If the fineness is out of this range, the thickness of the knitted fabric cannot be made moderate. Especially when used in a patch, it fits forgetting that a high-class feeling or a patch is applied to the affected area. It becomes impossible to embody the feeling.

  On the other hand, the expansion / contraction restoration rate needs to be 35 to 45%. If the stretch / restoration rate is less than 35%, if the patch is applied to a bent part of the body, such as the knee or elbow, the patch remains stretched when the knee or elbow is bent, and the fit is lost. On the other hand, if it exceeds 45%, the kickback property becomes strong, and a feeling as if a so-called rubber film is pasted is obtained.

  In addition, the expansion-contraction recovery rate as used in the field of this invention is a value measured according to JISL1013 8.12, and as a measurement sample, the polyester after being immersed in hot water of 95 ° C. for 10 minutes and sufficiently dried. Use false twisted yarn.

  As described above, the polyester false twist yarn of the present invention is suitable as a yarn constituting a woven or knitted fabric. In particular, the woven or knitted fabric can be suitably used as a knitted fabric for a patch. Then, this knitted fabric for patch is demonstrated.

  In the knitted fabric for a patch using the polyester false twisted yarn of the present invention (hereinafter sometimes referred to as the knitted fabric for a patch of the present invention), the content of the polyester false twisted yarn is not particularly limited. . However, from the viewpoint of making the effect of the present invention more effective, it is preferably 40% by mass or more, and more preferably 50% by mass or more.

Plasters for knitted fabric of the present invention, 80~140g / ^{m 2} is preferred as the basis weight. If the basis weight is less than 80 g / m ² , troubles tend to be caused in the process of producing the patch. On the other hand, if it exceeds 140 g / m ² , the knitted fabric tends to be thick, and it tends to be impossible to embody a sense of quality and a feeling of fit that forgets that the patch is applied to the affected area.

  In addition, as thickness of the knitted fabric for patch agents of this invention, about 400-700 micrometers is preferable.

  Moreover, in the knitted fabric for patch of the present invention, it is preferable that the elongation force during constant elongation is 10 N or less in the wale direction and 6 N or less in the course direction. When either one of the wale and the course direction does not satisfy the above range, it is not preferable because a feeling of tightening may be felt when a patch is applied to a bending or extending part such as an elbow or a knee. The elongation force at constant elongation is a value measured according to JIS L1018 8.14.1, and is theoretically preferable to be smaller.

  Furthermore, in the knitted fabric for patch of the present invention, it is preferable that the elongation elastic modulus is 80% or more in both the wale direction and the course direction. If the elastic modulus is less than 80% in any of the above directions, the patch applied to the affected area may sag, which is not preferable. The elongation elastic modulus is a value measured according to JIS L1018 8.15.1A method (constant elongation method).

  Here, as the test conditions for the above-mentioned elongation force at constant elongation and elongation elastic modulus, each is stretched to 50% elongation with a test width of 5 cm and a distance between grips of 20 cm according to the cut strip method.

  Next, a method for producing the polyester false twisted yarn of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic process diagram showing an example of a method for producing a polyester false twisted yarn of the present invention. In FIG. 1, first, a core-sheath composite yarn comprising a composite fiber having a core portion made of polylactic acid and a sheath portion made of aromatic polyester is used as a supply yarn 1, and after the supply yarn 1 is pulled out from a spool 2, a guide 3 is passed. The core-sheath composite yarn used as the supply yarn 1 may be either a drawn yarn or a highly oriented undrawn yarn, but a highly oriented undrawn yarn having a low crystal orientation is preferred.

  Thereafter, the supply yarn 1 is false-twisted in the process of sequentially passing through the feed roller 4, the heater 5, the false twisted twisted body 6 and the first delivery roller 7, and wound around the package 9 as the polyester false twist yarn of the present invention. It is done.

  Further, if necessary, for the purpose of torque reduction or the like, after installing the second heater 8 downstream of the first delivery roller 7 and passing through the first delivery roller 7 as shown in FIG. You may heat-process after false twisting.

  The polyester false twisted yarn of the present invention can be obtained by false twisting the supply yarn 1 as described above, and it is preferable that the following formula is satisfied simultaneously as specific conditions for the false twisting.

  The false twist coefficient K is expressed by the following formula.

  In the above formula (1), if the false twisting coefficient is less than 23,000, the expansion / contraction recovery rate of the false twisted yarn tends to decrease, which is not preferable. On the other hand, if it exceeds 30000, fuzz tends to occur in the false twisted yarn, which is not preferable.

  In the above formula (2), if the false twist heater temperature is less than 120 ° C., the crimp fastness of the false twist yarn tends to decrease, which is not preferable. On the other hand, when the temperature exceeds 140 ° C., the polylactic acid constituting the core portion becomes slightly brittle, and as a result, the expansion / contraction recovery rate of the false twisted yarn tends to decrease, which is not preferable.

  Polylactic acid has a melting point of about 180 ° C. and a much lower softening point. Therefore, when false twisting a general polylactic acid fiber yarn, it is usually necessary to set the false twist heater temperature around 100 ° C. This is because filaments stick together when the temperature exceeds 100 ° C. However, in the present invention, since the core-sheath composite yarn in which the aromatic polyester having a relatively high melting point and softening point is arranged in the sheath is used as the supply yarn, the filaments are stuck even if the false twist heater temperature exceeds 100 ° C. do not do. According to the study by the present inventors, although the reason is not clear, it can be confirmed that the crimp fastness of the false twisted yarn is drastically improved with respect to the false twist heater temperature at a temperature of 120 ° C. Even with the above, it was confirmed that the filaments did not stick together.

  Further, in the above formula (3), if the heat treatment time is less than 0.4 seconds, it is not preferable because it tends to be difficult to set an appropriate false twisting heater temperature. The upper limit of the heat treatment time is preferably 2.0 seconds. If it exceeds 2.0 seconds, the heater becomes longer, so it is not preferable because it tends to be difficult to secure a space for installing the machine base.

  Furthermore, the example of a manufacturing method of the knitted fabric for patch of this invention is demonstrated.

  In order to obtain the knitted fabric for patch of the present invention, first, a raw machine is produced using the polyester false twisted yarn. A commercially available knitting machine may be used for production of the raw machine, and the model may be arbitrary, but the needle density is preferably 26 to 32 / 2.54 cm.

  And the knitted fabric for patch agents of this invention can be obtained by dyeing the obtained raw machine. As the dyeing process, basically, scouring, drying, and presetting may be performed sequentially, and dyeing and auxiliary processing may be performed as necessary. Dyeing is usually performed after pre-setting, and the dye used is preferably a disperse dye. As dyeing | staining temperature, 100-130 degreeC is preferable, More preferably, it is 110-130 degreeC, Most preferably, it is 120-130 degreeC. The higher the dyeing temperature, the better the color developability. On the other hand, as an incidental process, the process using an antistatic agent, a softening agent, a water repellent, an antifouling agent, a deep color agent, a water absorbing agent etc. is employable. The incidental processing can be performed not only at any stage of the dyeing process, but also at the same time as, for example, dyeing.

  After dyeing or incidental processing, it is preferable to final set as a final step.

Next, the present invention will be described more specifically with reference to examples. In addition, each physical property value in the following examples etc. was measured by the following method. The physical property values other than those described below were the same as described above.
(1) Fineness Fineness (dtex)
It measured according to JIS L1013 8.3.1B method (simple method).
(2) Strength (cN / dtex), elongation (%)
Measured according to JIS L1013 8.5.1 standard time test. In addition, a constant speed extension type is adopted as a test type.
(3) Torque The sample is suspended in a U-shape, hooked and held at the position of the lower end 1 m, and 1/34 (cN / dtex) [1/30 (g / D)] is applied. Next, in the state where the load is applied, the vicinity of both upper ends of the sample is fixed with a fixture, and then the load is released. Then, a load of 1/340 (cN / dtex) [1/300 (g / d)] is applied to the lower end of the U-shaped sample. Then, since the sample swirled in the direction of twisting the U-shape, the number of twists per meter when the sample stopped swirling was obtained, and the number of twists was defined as torque.
(4) Fluff The fuzz of the false twist package was visually evaluated in the following three stages.
○: No problem, △: Slightly fuzzy, ×: Many fuzzy

(Example 1, Reference Example 1, Comparative Examples 1 to 4)
Polylactic acid (PLA) having a relative viscosity of 1.850, a melting point of 168 ° C., an L-lactic acid unit of 98.8 mol%, and a D-lactic acid unit of 1.2 mol% was used. On the other hand, copolymerized PET copolymerized with 8 mol% of isophthalic acid having a relative viscosity of 1.336 and a melting point of 230 ° C. was used as the aromatic polyester. Then, both polyesters were dried under reduced pressure, and then supplied to a concentric core-sheath type composite melt spinning apparatus to perform melt spinning. At this time, the polylactic acid is arranged as a core, and the aromatic polyester is arranged as a sheath. In Comparative Example 3, the core / sheath composite ratio (mass ratio) is 75/25, and in the other cases, the core / sheath composite ratio (mass). Ratio) was 50/50, melt spinning was performed at a spinning temperature of 260 ° C., and a spinning speed of 3050 m / min, to obtain a core-sheath composite yarn (highly oriented undrawn yarn) of 90 dtex / 36f.

  This core-sheath composite yarn is used as the supply yarn 1, false twisted under the conditions shown in Table 1 in accordance with the process shown in FIG. 1, and the polyester false twist yarns of the examples and reference examples of the present invention for comparison. A false twisted yarn was obtained.

Next, using each of the false twisted yarns, a living machine having an interlock structure was produced with a Fukuhara circular knitting machine (needle density: 28 / 2.54 cm). In addition, the fabric weight of the raw machine concerning Example 1 was 82 g / m < ² >.

  Using these raw machines, scouring was performed at 80 ° C. for 20 minutes (treatment liquid: nonionic activator concentration 1 g / L, soda ash concentration 5 g / L), then dried and preset. Furthermore, using a flow dyeing machine, dyeing is performed at 130 ° C. for 30 minutes with the following dyeing prescription, and further reduction washing at 70 ° C. for 20 minutes (treatment liquid: soda ash 2 g / L, hydrosulfite 1 g / L, nonionic surface activity Agent (Sunmall FL: manufactured by Nikka Chemical Co., Ltd.) 1 g / L). Next, drying and final setting were performed to obtain a knitted fabric.

《Dyeing prescription》
Dye: Kiwalon Polyester Black SK-269 Liquid (manufactured by Kiwa Chemical Co., Ltd.) 5% omf
Auxiliary agent: Disper TO (manufactured by Meisei Chemical Co., Ltd.) 1.0 g / L
pH adjuster: Acetic acid (concentration 48% by mass) 0.2 cc / L

  The results based on the above are shown in Table 1.

  As is apparent from Table 1, the knitted fabric using the polyester false twisted yarn of the present invention according to Example 1 is thin, stretches with low stress, and is excellent in restoring force, and is therefore suitable for a patch. It was usable. Moreover, since plant-derived polylactic acid is used, the environmental impact was small.

  The polyester false twisted yarn according to Reference Example 1 was able to satisfy the constituent requirements of the present invention, but because the false twisting coefficient at the time of production was too large, the strength was low, and a lot of fluff was generated in the false twisted yarn. Unraveling defects occurred during knitting, and the knitting machine stopped frequently. In addition, the knitted fabric is not particularly problematic from the viewpoint of physical properties, but we still have problems in terms of quality because wefts, stops, etc. were occasionally found.

  In Comparative Example 1, since the heater temperature was too low, in Comparative Example 2, the heater temperature was too high, and in Comparative Example 4, the false twisting coefficient at the time of manufacture was too small. The problem remained in terms of rate. Further, in Comparative Example 3, the core portion mass ratio of the composite fiber constituting the core-sheath composite yarn was too high, so that the sheath portion was cracked during false twisting, and the durability was such that the false twist yarn could withstand knitting. Could not have (thus knitting was stopped). As a matter of course, the core / sheath mass ratio of the polylactic acid and the aromatic polyester is between the composite fiber constituting the supply yarn 1 and the polyester core-sheath composite filament constituting the false twisted yarn corresponding thereto. Match.

(Comparative Examples 5 and 6)
In Comparative Example 5, the above-described polylactic acid was used alone to obtain a 90 dtex / 36f highly oriented undrawn yarn made of polylactic acid. In Comparative Example 6, the above-mentioned aromatic polyester was used alone to obtain a 90 dtex / 36f highly oriented undrawn yarn made of an aromatic polyester.

  Using this as a supply yarn, false twisting was performed under the conditions shown in Table 1 according to the steps shown in FIG. 1 to obtain a false twisted yarn for comparison.

  This comparative false twisted yarn was used in the same manner as in Example 1 to obtain a comparative knitted fabric. The results are shown in Table 1.

  As is clear from Table 1, the knitted fabric according to Comparative Example 5 remained problematic in terms of the elongation force at constant elongation and the elongation elastic modulus. Moreover, although the knitted fabric according to Comparative Example 6 has no particular problem in terms of physical properties, since it uses petroleum-derived aromatic polyester, it has a large environmental impact.

It is a schematic process drawing which shows the example of 1 manufacturing method of the polyester false twisted yarn of this invention. It is a schematic process drawing which shows the other example of a manufacturing method of the polyester false twisted yarn of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply yarn 2 Spool 3 Guide 4 Feed roller 5 Heater 6 False twisting body 7 1st delivery roller 8 2nd heater 9 Package

Claims (1)

Core portion polylactic acid, the sheath portion is composed of an aromatic polyester, Ri Do a polyester core-sheath type composite filament core / sheath weight ratio is 20/80 to 70/30, and, fineness 30~70dtex and stretch a knitted fabric recovery ratio is using 35-45% der Lupo Riesuteru temporary twist yarn, basis weight is 80~140g / ^{m 2,} constant elongation during stretching force is below 10N in the wale direction, course direction The knitted fabric for patch according to claim 1, wherein the elastic modulus is 80% or more in both the wale direction and the course direction.