KR101435972B1 - Partly oriented core-sheath polyester composite fiber, cheese-form package, and false-twisted fiber - Google Patents

Abstract

The present invention provides a partially oriented fiber and a cheese-like package preferable for mass production with less change with time in package shape, good tinning, stability of dyeing, soft feeling, . Wherein the core component is a core-sheath composite fiber wherein the core component is composed of polytrimethylene terephthalate and the component thereof is polytrimethylene terephthalate, and satisfies the following requirements (1) to (3).
(1) Shinto: 60 ~ 130%
(2) 70 ° C Hot water shrinkage rate: 0.5 to 7.0%
(3) Initial tensile resistance: 20 to 40 cN / dtex

Description

{PARTLY ORIENTED CORE-SHEATH POLYESTER COMPOSITE FIBER, CHEESE-FORM PACKAGE, AND FALSE-TWISTED FIBER}

The present invention relates to a false twisted fiber suitable for the production of polyester sheath-core compound part oriented fiber and cheese-like package and bulky yarn, and excellent stretchability, which are preferable for mass production with good workability, will be.

Polytrimethylene terephthalate (hereinafter sometimes referred to as PTT) is characterized by being excellent in softness because it has high elongation recovery property and low initial tensile resistance when made into a fiber. In addition, recent studies have been actively conducted as attractive polyester fibers that can compensate for the defects of polyethylene terephthalate (hereinafter, sometimes referred to as PET) fibers due to its dyes.

In order to further improve the softness by twisting the PTT fibers, the partially oriented fibers suitable for the twisting process have been actively studied. PTT partially oriented fibers (hereinafter sometimes referred to as " PTT-POY ") have problems such as a change in physical properties with time due to the shrinkage of the PTT-partially oriented fibers, poor wrinkling processability, In particular, many of these defects have been reviewed.

For example, there has been proposed a method in which a cheese-shaped package is well maintained and is wound while being cooled to improve flammability (see, for example, Patent Document 1). However, although the cheese-shaped package can maintain a somewhat good shape by the above-described method, it is necessary to cool the cheese-shaped package to some extent, so that the package is left at room temperature after taking the package, . Therefore, there has been proposed a method in which heat treatment is performed to take out partially oriented fibers to increase the degree of crystallization and reduce the heat shrinkage before winding (for example, see Patent Document 2 and Patent Document 3). In this method, the shape of the package is remarkably improved and the wrinkling processability is improved. However, when it is practically considered, the package shape is deteriorated when stored at room temperature for a long period of time. When stored for 3 months in a warehouse, It turned out to be a problem. In addition, since equipment for producing partially oriented fibers also requires a heat treatment facility, there is also a problem in that facility investment is required for mass production because conventional PET fiber production equipment that does not require heat treatment can not be used.

On the other hand, a core-sheath composite fiber having PTT as a super component has been proposed for fibers obtained by combining polylactic acid (hereinafter sometimes referred to as PLA) with polyester (see, for example, Patent Document 4). However, this proposal aims to improve the abrasion resistance and the resistance to hydrothermal heat degradation, which are shortcomings of PLA, and also does not mention solving the problem of PTT partially oriented fiber, which is PLA-based fiber, It is far behind in point. In the embodiment, although the core-sheath composite fiber having PTT as the superfine component and PLA as the core component is used, it does not solve the problem of the long-term storage and the problem of the false twisting process which is a problem unique to PTT-POY.

As described above, there is a demand for a partially oriented fiber which suppresses the deterioration of aging, which is a disadvantage of softness, which is an advantage of PTT, and a twisted processed fiber for obtaining a fabric with good quality. No technology was proposed.

Japanese Patent Application Laid-Open No. 2001-254226 (Claims) Japanese Patent Application Laid-Open No. 2001-020136 (Claims) Japanese Patent Application Laid-Open No. 2003-129328 (Claims) Japanese Patent Application Laid-Open No. 2004-353161 (Claims, Examples)

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, and it is an object of the present invention to provide a method of manufacturing a large- And which is favorable for the production of a partially oriented fiber and a cheese-like package, which are preferable for the warp knitted fabric, and a warp knitted fabric excellent in stretchability.

In order to achieve the above object, the present invention adopts the following configuration. That is, the polyester core-sheath composite part-oriented fiber of the present invention is a core-sheath composite fiber in which the core component is composed of poly (lactic acid) and the superfine component is composed of polytrimethylene terephthalate and has a elongation of 60 to 130% 7.0% and an initial tensile resistance of 20 to 40 cN / dtex.

In the polyester core-sheath composite fiber, the weight average molecular weight of the poly (lactic acid) is preferably 200,000 to 300,000, and the composite ratio is preferably 20 to 50% by weight.

The cheese-shaped package of the present invention is obtained by winding the polyester core-sheath composite part oriented fibers and after wrapping the package, after storage for 90 days in an atmosphere of 35 ° C and 60% RH, A bulge of -5 to 5%, and a saddle of 0 to 5%.

Further, the twisted processed fiber of the present invention is a core-sheath composite twisted filament fiber wherein the core component is composed of polytrimethylene and the second component is composed of polytrimethylene terephthalate. The CV% of the continuous wet heat shrinkage ratio is 0 to 5% A tensile strength of 20 to 40 cN / dtex, and a stretch shrinkage ratio of 25 to 60%.

(Effects of the Invention)

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a polyester core yarn suitable for mass production with less change in the package shape over time, good tinning resistance, Complex partially oriented fibers, and cheese-based packages. Further, it is possible to provide a twisted processed fiber which is excellent in stretchability, stretchability and softness and is capable of producing a fabric with stable quality. Further, the present invention can provide a polyester core-sheath composite part oriented fiber, a cheese-like package and a twisted processed fiber in consideration of the environment by using polytetrahydrofolic acid as a plant-derived raw material and PTT as a raw material of a part thereof as an ingredient.

1 is a schematic diagram illustrating bulges and saddles, which are indicators of packages and package forms.
Fig. 2 is a view showing an example of a preferred production facility of core-sheath complex partially oriented fibers.
3 is a view showing the PTT single-part oriented fibers prepared in Comparative Example 5 and the preparation facilities of the core-sheath composite fibers prepared in Comparative Examples 9 to 10.

Hereinafter, the present invention will be described in detail.

The partially oriented fiber of the present invention is a core-sheath composite fiber, wherein the core component is composed of polylactic acid (PLA) and the component of the core is polytrimethylene terephthalate (PTT). It is preferable that the core-sheath composite form is concentric in order to exhibit performance equivalent to that of the partially oriented fiber (PTT alone fiber) (hereinafter sometimes referred to as PTT alone partially oriented fiber) composed entirely of PTT. Since the partially oriented fiber is a straight fiber without crimp due to the concentric circle, it can be handled in the same manner as the PTT alone partially oriented fiber.

The core component of the partially oriented fiber of the present invention is PLA. The PLA used in the present invention is a polymer having 90 mol% or more of - (O-CHCH ₃ -CO) n- as a repeating unit, and polymerizing lactic acid or an oligomer thereof. However, a copolymerization component or a polyfunctional compound may be added in an amount of 10 mol% or less. Examples of the copolymerization component include aliphatic compounds which are easily biodegradable, such as diols such as ethylene glycol, butanediol, hexanediol and octanediol, and aliphatic lactones such as succinic acid, hydroxyalkylcarboxylic acid, pivalo-lactone and caprolactone Do. As the polyfunctional compound, glycerin, pentaerythritol, trimellitic acid, pyromellitic acid or the like may be reacted to form an appropriate branched or weakly crosslinked structure in the polymer. In addition, inorganic particles such as titanium dioxide may be added, but it is most preferable that inorganic particles such as titanium dioxide are not added in order to obtain a stable composite form in consideration of use as a core component. Since there are two kinds of optical isomers of D-lactic acid and L-lactic acid in lactic acid, the polymer is composed of poly (D-lactic acid) consisting solely of D-form and poly (L-lactic acid) have. The optical purity of D-lactic acid or L-lactic acid in polylactic acid is lowered, crystallinity is lowered, and melting point drop is larger. Therefore, in order to increase the heat resistance, the optical purity is preferably 90% or more. A more preferable optical purity is 93% or more, and a more preferable optical purity is 97% or more. The optical purity was confirmed to be strongly correlated with the melting point as described above. When the optical purity was about 90%, the melting point was about 150 캜, the optical purity was 93%, the melting point was about 160 캜, the optical purity was 97% .

In addition, as described above, the two kinds of optical isomers are blended and formed into fibers separately from the system in which two kinds of optical isomers are simply mixed, and then subjected to a high temperature heat treatment at 140 캜 or more to form racemic crystals It is more preferable that the melting point can be dramatically increased. Although a weight average molecular weight of 100,000 to 300,000 may be used, the weight average molecular weight and the obtained partially oriented fibers are related to changes over time, and it is preferable to use PLA of 200,000 or more to increase the effect of suppressing the change with time. In addition, if it is 300,000 or less, softness can be ensured. By employing polylactic acid as a core component, shrinkage of the partially oriented fibers is suppressed, the change with the passage of time is very small, and the deterioration of the tinning processability after a long time, which is a drawback of the conventional PTT alone partially oriented fiber, can be suppressed. The PTT partially oriented fiber obtained by the conventional technique of winding after heat treatment can surely suppress shrinkage to a certain extent but can not suppress the change with time considering practical use and deteriorates the package foam after aging, And the like can not be solved. However, the significance of the present invention is significant in that it has been found that the shrinkage characteristics which are never lowered in the PLA group and the PTT group can suppress the shrinkage greatly by the combination of PLA and PTT. In addition, poly (lactic acid) is a polymer made from lactic acid obtained by fermentation of sugar from a plant represented by corn, and is a highly preferable polymer that conforms to the way of thinking of carbon neutral since it does not use petroleum as a raw material. The significance of complexing this polylactic acid is significant.

On the other hand, the second component is PTT. The PTT used in the present invention is a polyester obtained by using terephthalic acid as a main acid component and 1,3-propanediol as a main glycol component. It is preferable that 90 mol% or more of PTT is composed of repeating units of trimethylene terephthalate. However, other copolymerizable components may be contained in a proportion of 10 mol% or less. Examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, and 5-sodium sulfoisophthalic acid, ethylene glycol, diethylene glycol, Butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, and the like, but are not limited thereto. Further, if necessary, titanium dioxide may be added as a matting agent, fine particles of silica or alumina as a lubricant, hindered phenol derivatives as an antioxidant, and coloring pigments may be added. In addition, if the PTT has an intrinsic viscosity of 0.8 to 1.2, it can be said that the fiberization is easy and preferable.

Next, the physical properties of the partially oriented fiber of the present invention will be described. First, the elongation is 60 to 130%. When the elongation is 60% or more, it is possible to suppress the shrinkage without performing the heat treatment in the sacrificial process, and the tearing processability is improved. A preferred elongation is 65% or more, and a more preferable elongation is 80% or more, and more preferably 90% or more. When the content is 130% or less, it is possible to suppress the change with time and maintain the good tinning property even when stored for a long period of time. , Preferably not more than 125%, and more preferably not more than 120%. In the case of partially oriented fibers, elongation can be adjusted by the spinning speed in that it does not involve stretching. Even if the same spinning speed varies depending on the polymer used, the elongation is different, but the spinning speed of 2600 m / min or more and 3700 m / min or less makes it easier to obtain the elongation of the present invention.

Then, the water shrinkage percentage at 70 캜 is 0.5 to 7%. If the water shrinkage percentage at 70 ° C is 0.5% or more, it can be handled in the same manner as PET fibers because heat shrinkage is not elongated and shrunk clearly. If it is 7% or less, deterioration of the package is suppressed even after long-term storage in the warehouse, so that the processability at the time of false twisting is improved. More preferably, the water shrinkage percentage at 70 캜 is 6% or less, more preferably 3% or less. The water shrinkage at 70 ° C is mainly determined by the spinning speed, the composite ratio of PLA as the core polymer, and the presence or absence of heat treatment. The spinning speed is preferably 2600 m / min or more and 3700 m / min or less in order to obtain a prescribed elongation, but when the spinning speed is high, the water shrinkage rate at 70 ° C tends to be high. In PTT alone partially oriented fibers, even if the spinning speed is set low, the hot shrinkage rate at 70 ° C is higher than 40%. For this reason, in the prior art, when obtaining partially oriented fibers, heat treatment is performed to lower the shrinkage percentage. However, this method deteriorates the tin-formability after long-term storage as described above. Therefore, in the present invention, it is important to make a core-sheath composite partially oriented fiber comprising PTT as a super component and PLA as a core component. By combining PLA as a core component, it is possible to perform stable twist processing even after storage for a long period of time. In addition, heat treatment for obtaining partially oriented fibers becomes unnecessary, and since conventional PET single- It is preferable for production.

The larger the composite ratio of PLA, the lower the 70 ° C hot shrinkage rate. If the composite ratio is 20 wt% or more, it is preferable to lower the shrinkage percentage. More preferably, the composite ratio of PLA is 30 wt% or more. However, attention should be paid to the composite ratio of PLA. It is important that the core-sheath composite segment oriented fibers of the present invention have the same performance and handleability as the PTT single segment oriented fibers, and therefore it is necessary to maintain the softness which is a great characteristic of PTT. The softness of PTT can be represented by the initial tensile resistance, and in order to maintain this softness, the composite ratio of PLA is preferably 50 wt% or less, more preferably 45 wt% or less, and most preferably 40 wt% Or less.

The initial tensile resistance of the partially oriented fibers of the present invention is 20 to 40 cN / dtex. As described above, it is important that it can be used in the same manner as PTT alone partially oriented fibers, and it is necessary to combine softness, which is an important characteristic of PTT. The initial tensile resistance of the PET single-part oriented fibers is about 90 cN / dtex, while the PTT single-part oriented fibers have 20 to 40 cN / dtex, and when it is 40 cN / dtex or less, sufficient softness can be exhibited. The initial tensile resistance can be attained only when the PTT is a single partially oriented fiber, but it is not preferable because there is a problem of tinning after long-term storage as described above. In the core-sheath composite partially oriented fiber comprising PLA as a core component, it is easy to reduce the initial tensile resistance to 40 cN / dtex or less by reducing the composite ratio of PLA to 50 wt% or less. The second component can achieve the same softness as the PTT alone partially oriented fiber by using PTT. Preferably 34 cN / dtex or less, and more preferably 32 cN / dtex or less.

The strength of the partially oriented fiber of the present invention may be set within a range in which there is no problem in obtaining a fabric. With respect to the strength, when it is 1.5 cN / dtex or more, breakage of the yarn at the time of false twisting is unlikely to occur. Further, it is preferable to set it to 3.1 cN / dtex or less because it is easy to obtain the elongation specified in the present invention.

The polyester fiber of the present invention is wound around a paper tube or the like, and is supplied as a cheese-shaped package as shown in Fig. The shape of the cheese-shaped package is preferably -5 to 5% of the bulge and 0 to 5% of the saddle. As shown in Fig. 1, the maximum diameter Dmax, the minimum diameter Dmin, the maximum width Wmax and the minimum width Wmin of the package are measured and saddle and bulge are calculated by the following formula.

Saddle (%) = {(Dmax-Dmin) / Dmin} x 100

Bulge (%) = {(Wmax-Wmin) / Wmin} x 100

The saddle and bulge were measured after storage for 90 days in an atmosphere of 35 ° C and 60% RH after the package was wound.

If the saddle or the bulge is large, the hardness of the fiber in the package is uneven. In particular, when the birds are large, the fibers are hard in the portion having the maximum diameter, and conversely, the fibers are likely to be soft in the portion having the minimum diameter. If the hardness of the fiber is uneven, there is a variation in the working tension when the yarn is subjected to the false twisting using the yarn, and the yarn breakage occurs. In addition to this, deviation in the dyeing of the obtained yarn is caused, . When the saddle and the bulge are within the above range, the unevenness of the fibers in the package is suppressed to improve the workability, and besides, it is possible to suppress degradation of the quality of the fabric surface caused thereby. A more preferable range of the bulge is -4 to 4%, and a more preferable range of the saddle is 0 to 3%.

In order to set the saddle and bulge to the desired range, generally, the package shape can be improved immediately after the winding by setting the tension at the time of winding appropriately. However, in the case of PTT alone partially oriented fiber, there is no problem immediately after package winding, It is difficult to keep it deteriorated. In the present invention, a good package can be obtained even after long-term storage by using PLA as the core component and PTT as the second component. In addition, if the composite ratio of PLA is 20 to 50 wt%, a good package shape can be obtained.

The late shrinkage percentage of the core-sheath composite partially oriented fiber taken from the package is preferably 0 to 1.8%. Here, the retardation shrinkage is defined as a value obtained by taking 1 m of partially oriented fibers within 15 minutes after the package is wound and measuring the length when a load of 5.4 x ^10-3 cN / dtex is applied at 5.4 And the length after standing for 48 hours under a load of 占 10 ^-3 cN / dtex is taken as L4, the following formula is obtained.

Retardation shrinkage percentage (%) = {(L3-L4) / L3} 100

By setting the retardation shrinkage ratio to 1.8% or less, it is possible to easily suppress the hardness of winding of the package after the package is wound, and to suppress the rate of change of the expansion rate over time. A more preferable retardation shrinkage is 1.5% or less.

Next, a preferable production method of the core-sheath composite portion oriented fiber of the present invention will be described.

A process of melting the PTT, a process of melting the PLA, a process of joining the two molten polymers into the core by claws, a process of discharging the merged polymer from the claw, a process of pulling out the discharged polymer, And winding it as a cheese-shaped package. This method may be the same as the conventional method of obtaining PET single-partly oriented fibers. So that it is possible to produce a large quantity at low cost. In the conventional PTT single partly oriented fibers, the heat treatment process was necessary, so that the equipment of PET single partly oriented fibers could not be used.

However, since PTT has a higher thermal deterioration than PET, it is preferable to melt and radiate PTT at a temperature as low as possible. The preferred temperature is 235 to 250 ° C. On the other hand, since PLA has a lower melting point, the preferred temperature for melting and spinning is 190 to 245 ° C. It is preferable to set the melting time as short as possible in order to suppress heat deterioration in both cases. Therefore, the melting is preferably performed by an extruder. Further, it is most preferable to set the temperature for separating PTT and PLA from the melting and spinning to 240 to 265 ° C and 190 to 220 ° C, respectively.

The present invention also provides a core-sheath composite false twisted fiber comprising PLA as a core component and PTT as a core component for a twisted processed fiber, wherein CV% of the continuous wet heat shrinkage ratio is 0 to 5% 40 cN / dtex, and the stretch shrinkage ratio is 25 to 60%.

As described above, PLA is a polymer having 90 mol% or more of - (O-CHCH ₃ -CO) n- as a repeating unit and polymerizing lactic acid or an oligomer thereof. However, a copolymerization component or a polyfunctional compound may be added in an amount of 10 mol% or less. In addition, inorganic particles such as titanium dioxide may be added, but it is most preferable that inorganic particles such as titanium dioxide are not added in order to obtain a stable composite form in consideration of use as a core component. Since there are two kinds of optical isomers of D-lactic acid and L-lactic acid in lactic acid, the polymer is composed of poly (D-lactic acid) consisting solely of D-form and poly (L-lactic acid) have. The optical purity of D-lactic acid or L-lactic acid in polylactic acid is lowered, crystallinity is lowered, and melting point drop is larger. Therefore, in order to increase the heat resistance, the optical purity is preferably 90% or more. A more preferable optical purity is 93% or more, and a more preferable optical purity is 97% or more. As described above, the optical purity was confirmed to be strongly correlated with the melting point, and the optical purity of about 90%, the melting point of about 150 캜, the optical purity of 93%, the melting point of about 160 캜, the optical purity of 97% .

Further, as described above, the two kinds of optical isomers are blended and formed into fibers separately from a system in which two kinds of optical isomers are simply mixed, and then subjected to a high temperature heat treatment at 140 캜 or more to obtain a racemic crystal The stereocomplex formed is more preferable because it can drastically increase the melting point. The weight average molecular weight and the thermal stability of the resulting twisted processed fiber are related to each other, and the use of PLA having a weight average molecular weight of 100,000 to 300,000, Do. In addition, if it is 300,000 or less, softness can be ensured. By adopting polylactic acid as a core component, shrinkage of the twisted fiber can be stabilized, and the drawbacks of the conventional PTT singly twisted fabric can be improved. In addition, it is easy to maintain the initial shrinkage recovery rate at a high level while maintaining the initial tensile resistance as described later, by appropriately combining the core and the sheath. The preferable composite ratio is 20 wt% or more, and it is easy to satisfy the stability of the shrinkage and the stretchability. Preferably 30 wt% or more. In addition, when the content is 50 wt% or less, the stretch shrinkage ratio is maintained high, and the softness is equivalent to that of the PTT alone. More preferably, it is 45 wt% or less. With respect to the stretch shrinkage ratio, it is convex upward relative to the PLA composite ratio, and when it is 20 to 50 wt%, a high stretch shrinkage ratio can be easily obtained. In the prior art, PTT false-twist textured fibers satisfying all of them can not be obtained, and a fabric that combines softness, baldness and stretchability can not be practically obtained. In addition, poly (lactic acid) is a polymer made from lactic acid obtained by fermentation of sugar from a plant represented by corn, and is a highly preferable polymer that conforms to the way of thinking of carbon neutral since it does not use petroleum as a raw material. The significance of complexing this polylactic acid is significant.

On the other hand, the second component is PTT. The PTT used in the present invention is a polyester obtained by using terephthalic acid as a main acid component and 1,3-propanediol as a main glycol component. It is preferable that 90 mol% or more of PTT is composed of repeating units of trimethylene terephthalate. However, other copolymerizable components may be contained in a proportion of 10 mol% or less. Further, if necessary, titanium dioxide may be added as a matting agent, fine particles of silica or alumina as a lubricant, hindered phenol derivatives as an antioxidant, and coloring pigments may be added. In addition, if the PTT has an intrinsic viscosity of 0.8 to 1.2, it can be said that it is preferable because it is easy to perform the false twisting process.

In order to obtain the twisted fiber of the present invention, it is most preferable to use the above-mentioned partially oriented fiber of the present invention. The partially oriented fiber of the present invention is soft and easy to be twisted even after being stored in a warehouse because the shrinkage as a partially oriented fiber is suppressed to a low degree and the elongation is moderate and the change with time is very small. This is because softness, bulging property, stretchability, and shrinkage of the obtained false-twisted fiber can be stabilized.

The CV% of the continuous wet heat shrinkage percentage is the CV% of the wet shrinkage percentage at 100 占 폚 calculated by a measuring method described later. The CV% of the continuous wet heat shrinkage percentage of 5% or less means that the shrinkage is large, the package foam is poor, the shrinkage unevenness caused by the change with time is small, and the unevenness, softness, smoothness Is good. It is possible to suppress the deterioration of the CV% of the continuous wet heat shrinkage ratio after long-term storage, which has been a problem in conventional PTT single-twist-processed fibers, in the core-sheath composite false-twisted fiber obtained by compounding PLA as a core. In addition, the CV% of the preferred length of continuous wet heat shrinkage is 4% or less, and most preferably 3.5% or less. In order to suppress the CV% of the continuous wet heat shrinkage ratio, it is effective to make the weight average molecular weight of PLA used as a core component at 200,000 or more. When the elongation percentage of the partially oriented fiber is about 70%, it is 1.2 times or more, preferably 1.3 times or more, and when the elongation is about 100%, 1.3 times or more, preferably 1.4 times or more, Is about 1.45 times or more, preferably 1.5 times or more, when it is about 120%. If the elongation of the partially oriented fiber to be used is 65%, the processing magnification can be maintained, which is preferable.

Regarding the initial tensile resistance, it is important that the core-sheath compounded twisted fibers of the present invention can be used in the same manner as the PTT single twisted fabric, and it is necessary to combine softness, which is an important characteristic of PTT. The initial tensile strength of the PET single-twisted fabric is about 90 cN / dtex, while the amount of the PTT single twisted fabric is 20 to 40 cN / dtex, and when it is 40 cN / dtex or less, sufficient softness can be exhibited. The initial tensile resistance can be achieved by PTT singly burnt processed fibers, but is undesirable because there is a problem of CV% deterioration of the continuous wet heat shrinkage ratio after long-term storage. It is easy to make the initial tensile resistance to 40 cN / dtex or less by making the composite ratio of PLA to 50 wt% or less in the core-sheath composite false twisted fiber made of PLA as a core component. The second component uses PTT. This makes it possible to achieve the same softness as the PTT single twisted fabric. Preferably 34 cN / dtex or less, and more preferably 32 cN / dtex or less.

The stretch shrinkage rate is a measure of the collapse of the crimp crimp, and the higher the value, the more the crimp or bulge resistance is to counteract the binding force when the shrinkage is made. By setting the stretch shrinkage ratio to 25% or more, it is possible to obtain a fabric with good stretchability and flexibility. It is easy to obtain a fiber having a high expansion / contraction ratio by obtaining a twist-processed fiber from a core-sheath composite partially oriented fiber in which PLA is disposed in the core. PLA has a low melting point, it is considered that the polymer is easily softened by heat application at the time of false twisting, and the crimp can be applied without impairing the softness of the PTT. When the weight average molecular weight of PLA is 200,000 or more, the effect becomes high, and when the stretch shrinkage percentage is 30% or more, more excellent warpage can be obtained. Most preferred is 35% or more. In addition, by setting the elongation and contraction ratio to 60% or less, flexible fabric can be obtained without compromising the softness of the PTT. Generally, it is known that a high stretch recovery ratio leads to roughening of the fabric. However, by setting the weight average molecular weight of the PLA blended in the core to 200,000 or more, even in the case of high stretch shrinkage, So that it is particularly preferable.

As the tentative processing, known methods such as a pin method, a friction method, a belt nip method and the like can be adopted. For example, in the case of the friction type, the burnable heater (first heater) is processed by using a stretchable twin processing machine having a contact heater at a temperature of 100 to 160 캜, preferably 100 to 150 캜. It is also possible to use a so-called two-heater twisting process in which a low-shear low-torque yarn is obtained by lowering the torque of a workpiece thermally set by a first heater using a second heater. In this case, the second heater may be a contact type or a non-contact type, and the second heater temperature is suitably in the range of 100 to 150 占 폚, preferably 100 to 140 占 폚. The processing speed is usually 400 to 800 m / min, and a false disk may be a urethane disk, a ceramic coated disk, or the like. The processing magnification is not less than 1.2 times, preferably not less than 1.3 times, and not less than 1.3 times, preferably not less than 1.4 times, more preferably not less than 1.3 times, , And when the elongation is about 120%, it is 1.45 times or more, preferably 1.5 times or more, so that the orientation of the PLA blended in the core is increased, so that it is easy to suppress the CV% of the longitudinal continuous shrinkage ratio, . Further, by setting the ratio of the main speed D to the machining speed Y (hereinafter sometimes referred to as the D / Y ratio) of the misalignment hole to 1.4 to 1.8, preferably 1.5 to 1.8, it becomes possible to increase the elongation shrinkage ratio. In the twisted processed fiber of the present invention, which is a core-sheath structure of a combination of PLA and PTT, the holding performance of crimp by mechanical and thermal crimping is high and there is no so-called collapse.

The core-sheath composite false-twist textured fiber of the present invention can be made into a woven fabric including medical use, thereby providing a fabric that combines softness and good durability, and can provide medical treatment capable of suppressing shrinkage even with heat of a dryer or the like. Especially, the use as a material in a vehicle is preferable because it can tolerate a very small change with time even in a severe environment of a vehicle, and can be said to be optimal because it can contribute to the propulsion of carbon neutral in the automobile industry.

(Example)

Hereinafter, the embodiment will be described in detail by way of example. In addition, the main measurement values of the examples were measured by the following methods.

(1) Intrinsic viscosity

The intrinsic viscosity [?] Is a value obtained by measuring the viscosity at 30 占 폚 using orthochlorophenol as a solvent and calculating the following formula. Here, C is the concentration of the solution, and? R is the relative viscosity (the ratio of the viscosity of the solution at the predetermined concentration C to the viscosity of the solvent).

(2) Weight average molecular weight

Measurement was made using polystyrene as a standard using gel permeation chromatography 2690 manufactured by Waters. The measurement conditions are as follows.

Solvent: chloroform (Wako, for HPLC)

Temperature: 40 ° C

Flow rate: 1 ml / min

Sample concentration: 10 mg / 4 ml

Filtration: Mashiori disk 0.5 mu TOSOH

Injector: 200 μl

Detector: Differential oyster RI (Waters 2410)

Standard: Polystyrene (Concentration: 0.15 mg of sample / 1 ml of solvent)

Measurement time: 40 minutes.

(3) Strength, elongation, initial tensile resistance

And measured according to JIS L1013 (1999). The strength and elongation were measured at a clamping interval of 20 cm and a tensile rate of 50% / min according to JIS L1013 (1999) 8.5 section "Tensile strength and elongation". The initial tensile resistance was measured according to JIS L1013 (1999) 8.10 with a clamping interval of 20 cm and a tensile speed of 50% / min. In addition, the measurement sample is to be used for 12 hours or more and 48 hours or less after the package is taken. The initial load was 0.088 cN / dtex in the measurement of the twisted fiber.

(4) 70 ° C hot water shrinkage

Wind the fiber to failure of 1 m x 10 cycles. The failure length when the load of 29 × 10 ^-3 cN / dtex was applied to the failure was treated with L0 and the failure was applied with the load of 0.29 × 10 ^-3 cN / dtex for 10 minutes by hot water at 70 ° C., The hot water shrinkage rate at 70 캜 is calculated by the following formula, with the failure length at the time of applying the load of 29 × 10 ^-3 cN / dtex as L1.

70 캜 Warm water shrinkage percentage (%) = {(L 0 -L 1) / L 0} × 100

In addition, the measurement sample is to be used for 12 hours or more and 48 hours or less after the package is taken.

(5) Birds in the package, bulge

In each of the examples and the comparative examples, when winding the partially oriented fibers, a package of 8 kg (winding diameter: about 340 mm) is obtained by winding the paper with a winding width of 114 mm on a paper tube having a diameter of 134 mm. The obtained package was allowed to stand in an atmosphere of 35 캜 and 60% RH for 90 days, and then the shape of the package was measured. As shown in Fig. 1, the maximum diameter Dmax, the minimum diameter Dmin, the maximum width Wmax and the minimum width Wmin of the package were measured and saddle and bulge were calculated by the following formula. The first digit of the decimal number is rounded off to an integer value.

Saddle (%) = {(Dmax-Dmin) / Dmin} x 100

Bulge (%) = {(Wmax-Wmin) / Wmin} x100.

(6) Delay shrinkage

A length of 1 m of the partially oriented fiber within 15 minutes after the package was wound and a load of 5.4 × 10 ^-3 cN / dtex was applied, and the length of the package was 5.4 × 10 ^-3 cN / dtex And the length after standing for 48 hours under the load of L4 was calculated by the following equation. The second decimal place is rounded to the first decimal place.

Delayed shrinkage percentage (%) = {(L3-L4) / L3} x100.

(7) Tensile strength of processed fibers

(An ingot false twist, a processing speed of 400 m / min, a stretching magnification is adjusted so that the elongation of the false-twisted fiber is 40%), and the first A heater temperature of 145 占 폚, and a second heater temperature of 130 占 폚). Four pieces of twist-processed fibers of 2 kg of the wound were taken and divided into 400 pieces of mischievable fibers from 100 core-sheath composite partial oriented fibers. The ratio of the fibers that were able to collect 2kg of flammable fibers in 400 flammable fibers without breakage of yarns was calculated. The first digit of the decimal number is rounded off to an integer value. The core-sheath composite partially oriented fibers used were those kept for 90 days in an atmosphere of 35 ° C and 60% RH.

(8) Textile knitting test

A 28-gauge circular knitted fabric was fabricated using four twisted fabric fibers taken from the core-sheath composite part oriented fibers of any package among the twist-processed fibers collected in (7). In the dyeing method, 0.275% owf of tetrasil navy blue SGL as a dye, 5.0% owf of tetrosin PE-C manufactured by Seiken Cargo Co., Ltd., and Nikkasan Salt # 1200 manufactured by Nikkakaka Kagaku Co., Ltd. Using 1.0% owf at a bathing ratio of 1: 100 at 50 占 폚 for 15 minutes and at 90 占 폚 for 20 minutes. The evaluation of the dyeing irregularity and the difference in dyeing between yarns was carried out in three stages according to the consensus of three evaluators over three years of experience. The acceptance level is △ or better.

○: Very homogeneous and excellent quality

△: Stable quality, shipment possible

X: Significant defects exist which can not be shipped.

(9) Soft castle

The 28 gauge circular knitted fabric obtained in (8) was subjected to a sensory evaluation of sensory evaluation by two consecutive evaluations by three evaluators with three or more years of experience. Also, the acceptance level is ○.

○: Excellent

X: Hard.

(10) Overall evaluation of partially oriented fibers

(7), (8), and (9), and conducted a comprehensive evaluation. More than 95% of flammable processed fibers passed the test, and the flammable fiber test was accepted as △ or better, and the softness accepted as ○. When any one of the above three evaluations was rejected, it was evaluated as " x "

(11) CV% of continuous wet heat shrinkage percentage

The shrinkage ratio of the twisted processed fiber was measured continuously at 100 占 폚 in wet heat at a feeding speed of 10 m / min, a measuring yarn length of 30 m, a yarn tension of 20 gf and a moist heat temperature of 100 占 폚 using a FTA-500 manufactured by Toray Engineering Co., Respectively. The first two digits of the decimal number are rounded to the first decimal place.

(12) Young's modulus

The false-twisted fiber was wound around a failure of 1 m × 10 times, treated in boiling water at 100 ° C. for 15 minutes in a no-load state, and then dried by wind for 24 hours. The heat treated sample was subjected to a load of 0.00176 cN / dtex and a load of 0.0882 cN / dtex in water according to JIS L1013 (1999) Section 8.13 "Elastic Restoration Ratio" to measure the failure length L0 after 2 minutes. Subsequently, the load length of 0.0882 cN / dtex was subtracted from water, and the failure length L1 after 2 minutes was measured with a load of 0.00176 cN / dtex only. The stretch recovery ratio was calculated by the following formula. The first digit of the decimal number is rounded off to an integer value.

(Elongation shrinkage restoration ratio) = (L0-L1) / L0 100 (%).

(13) Stretchability

(8) Twenty-eight gauge circular knitted fabrics were produced in the same manner as in the knitting test of the fibers, and the stretchability of the knitted fabric was evaluated in three stages by the consensus of three evaluators over three years of experience. Also, the acceptance level is △ or more.

?: Uniform, excellent stretchability, and good resilience

[Delta]: uniform stretchability, the range of eye size of the knitted fabric remained a little but there is no practical problem

X: The stretch property is insufficient, and a trace mark remains.

(14) Overall evaluation of flameproof fibers

(9), and (9) softness, and (13) evaluation of stretchability. All of the accepted levels were evaluated as acceptable. One of them was rejected.

Example 1

PLA (poly-L-lactic acid) having an optical purity of 98.0% and a weight average molecular weight of 21.4 million as a core component and a homo PTT having an intrinsic viscosity of 1.1 as a supercritical component were used. The PLA was melted at 190 DEG C and PTT was melted at 250 DEG C using an extruder , The PLA composite ratio was 30 wt%, and the PTT composite ratio was 70 wt%. Then, the mixture was subjected to centrifugal separation at a temperature of 240 ° C. The discharged polymer was made into a partially oriented fiber by a radiator shown in Fig. The speed of the first roller 4 was pulled up to 2700 m / min. After passing through the second roller 5 at the same speed, the web was wound at 2650 m / min to obtain a cheese-shaped package 7. Further, the first roller 4 and the second roller 5 are at room temperature instead of the heating roller.

The resulting core-sheath composite partially oriented fibers exhibited excellent elongation at 120% elongation, 70% hot shrinkage at 1.8%, initial tensile resistance at 29 cN / dtex, and a retardation shrinkage of 0.6%. The resulting package was stored for 90 days in an atmosphere of 35 ° C and 60% RH, and the measured bulge and saddle were satisfactory. The full ductile rate of the spunbond fabric was sufficient to 97%, and the knitting test and the softness were all good. The results are shown in Table 1.

Examples 2 to 4

PLA composite ratio and PTT composite ratio were changed as shown in Table 1, the same procedure as in Example 1 was repeated to obtain core-sheath composite partially oriented fibers. As shown in Table 1, very good results were obtained. Particularly, in Example 4, all evaluation items were well balanced and good results were obtained which were equal to or better than those in Example 1.

Example 5

The core-sheath composite part oriented fibers were obtained in the same manner as in Example 2 except that the weight average molecular weight of PLA was 16.5. Since the PLA molecular weight is low, the water shrinkage ratio at 70 캜 is slightly higher, and therefore good results are obtained even though the package form and the knitted fabric are knitted together.

Comparative Examples 1 to 2

PLA composite ratio and PTT composite ratio were changed as shown in Table 1, the same procedure as in Example 1 was repeated to obtain core-sheath composite partially oriented fibers. In Comparative Example 1 in which the PLA composite ratio was set at 10%, it was insufficient to suppress the hot shrinkage at 70 캜, resulting in bad bulging and poor processability. Further, in Comparative Example 2 in which the PLA composite ratio was 60 wt%, only the knitted fabric with an initial tensile resistance of 48 cN / dtex and poor softness was obtained.

Comparative Example 3

The core-sheath composite segment oriented fibers were obtained in the same manner as in Comparative Example 2 except that the weight average molecular weight of PLA was 16.5. The initial tensile resistance was high, resulting in poor softness.

Comparative Example 4

Homo PTT having an intrinsic viscosity of 1.1 was used and melted by using an extruder at 250 ° C and then metered by a pump. Then, the mixture was core-sheathed by a spinneret and discharged at a temperature of 240 ° C. The discharged polymer was made into a partially oriented fiber by a radiator shown in Fig. The speed of the first roller 4 was pulled up to 2700 m / min. After passing through the second roller 5 at the same speed, the web was wound at 2650 m / min to obtain a cheese-shaped package 7. Further, the first roller 4 and the second roller 5 are at room temperature instead of the heating roller. The obtained partially oriented fiber had a high water shrinkage rate of 70% at a high temperature of 46%, resulting in poor bulge, saddle and delayed shrinkage, a false-twist ratio of 65%, and poor knitting test.

Comparative Example 5

Homo PTT having an intrinsic viscosity of 1.1 was used and melted by using an extruder at 250 ° C and then metered by a pump. Then, the mixture was core-sheathed by a spinneret and discharged at a temperature of 240 ° C. The discharged polymer was made into a partially oriented fiber by a radiator shown in Fig. The first heating roller 8 was pulled at a speed of 2700 m / min by setting the temperature to 80 ° C, passed through a second heating roller 9 at the same speed set at 120 ° C, and wound up at 2650 m / A package 7 was obtained. The resultant partially oriented fiber exhibited a good shrinkage ratio at a temperature of 70 ° C of 2.8%, and the package immediately after winding had good saddle and bulge. However, after 90 days of storage, the package deteriorated. Respectively. Further, as a comparison, the partially oriented fibers of Comparative Example 5 were not stored, and after 5 days from the package collection, they were subjected to flammability processing, and as a result, the completing rate of flammable processing was 96%. In Comparative Example 5, it was found that the tin-formability was deteriorated by long-term storage.

Examples 6 to 8 and Comparative Examples 6 to 8

The core-sheath composite segment oriented fibers were obtained under the same conditions as in Example 1 except that the speeds and the winding speeds of the first roller 4 and the second roller 5 in Fig. 2 were changed as shown in Table 1. Comparative Example 6 in which the elongation of the present invention, the hot shrinkage percentage at 70 占 폚, the initial tensile resistance degree, the saddle of the package, and the bulge were satisfactory in Examples 6 to 8 and good elongation was 143% % In Comparative Example 7, it was thought that there were many amorphous portions in the unoriented portion, so that the fullness ratio of the false twisted yarn after 90 days of storage was insufficient. Further, in Comparative Example 8 in which the elongation was 52%, the hot shrinkage rate at 70 캜 was not able to be suppressed, and the bulge of the package after 90 days of storage deteriorated, resulting in a significantly poor processability.

Comparative Example 9

Homo PTT having an intrinsic viscosity of 0.5 as a core component and homo PTT having an intrinsic viscosity of 1.1 as a second component were melted using an extruder at 290 ° C for PTT and 250 ° C for PTT to obtain a PET composite ratio of 30wt% and a PTT composite ratio of 70wt% , And then discharged at a temperature of 270 DEG C by core-sheath blending by punching. The discharged polymer was made into a partially oriented fiber by a radiator shown in Fig. The first heating roller 8 was set at a temperature of 100 ° C and punched at a speed of 3000 m / min. After passing through a second heating roller 9 at the same speed as that of the non-heating setting, the first heating roller 8 was wound at 2960 m / A package 7 was obtained.

The obtained core-sheath composite partially oriented fiber exhibited good physical properties at 125% elongation, 70% hot water shrinkage at 3.8%, initial tensile resistance of 34 cN / dtex, and the package immediately after winding had good saddle and bulge. , And the false twist ratio was 93%, which is insufficient, and the knitted fabric test result was unsatisfactory.

Comparative Example 10

Homo PTT having an intrinsic viscosity of 0.5 as a core component and homo PTT having an intrinsic viscosity of 1.1 as a second component were melted using an extruder at 290 ° C for PTT and 250 ° C for PTT to obtain a PET composite ratio of 30wt% and a PTT composite ratio of 70wt% , And then discharged at a temperature of 270 DEG C by core-sheath blending by punching. The discharged polymer was made into a partially oriented fiber by a radiator shown in Fig. The first heating roller 8 was set at a temperature of 55 DEG C and pulled at a speed of 1600 m / min. After drawing to a second heating roller 9 set at a temperature of 150 DEG C and a speed of 3800 m / min, To obtain a cheese-shaped package (7). The resulting core-sheath composite fibers were stretched so that the elongation was 58%, the hot shrinkage at 70 캜, the initial tensile resistance, the saddle and the bulge were all good, but sufficient softness could not be obtained.

Example 9

The partially oriented fibers obtained in Example 1 were stored for 90 days in an atmosphere at 35 DEG C and 60% RH, and subjected to friction-type twist processing (indentation false twist) using a urethane disk. Processing was carried out at a processing speed of 400 m / min, a processing magnification of 1.6, a D / Y ratio of 1.5, a first heater temperature of 145 캜, and a second heater temperature of 130 캜 to obtain spunbonded fibers of 84 dtex-36 filaments. The CV% of the continuous wet heat shrinkage percentage was 3.4%, the initial tensile resistance was 28cN / dtex, and the shrinkage restoration ratio was 35%. As shown in Table 3, good fabricability, softness and stretchability were obtained.

Examples 10 to 12

In order to see the influence of the composite ratio of PTT and PLA, the partially oriented fibers of Example 4 were used as Example 10, the partially oriented fibers of Example 3 were used as Example 11, the partially oriented fibers of Example 2 were used as Example 12, And stored for 90 days in an atmosphere of 35 ° C and 60% RH, respectively, and subjected to twist processing under the same conditions as in Example 9 except for using them to obtain a twisted processed fiber. In all of Examples 11 and 11, CV% of the continuous wet heat shrinkage ratio was suppressed to be low, sufficient expansion / contraction ratio and initial tensile resistance were obtained.

Example 13

The partially-oriented fibers of Example 5 were stored for 90 days in an atmosphere of 35 ° C and 60% RH, respectively, and then subjected to twist processing under the same conditions as in Example 12 to obtain twist-processed fibers. Since the weight average molecular weight of the PLA was low, the CV% of the continuous wet heat shrinkage ratio was slightly higher, and the knitting test and the stretchability were slightly inferior to those of Example 12, but good warpage was obtained.

Comparative Example 11

And the partially oriented fibers of Comparative Example 1 were stored for 90 days in an atmosphere of 35 ° C and 60% RH, respectively, and then subjected to twist processing under the same conditions as in Example 9 to obtain twisted processed fibers. PLA composite ratio is low, the CV% of the continuous wet heat shrinkage ratio can not be suppressed, the stretch shrinkage ratio is also insufficient, and stretchability is insufficient.

Comparative Example 12

The composite ratio of PTT and PLA was 45:55, and the partially oriented fiber was obtained in the same manner as in Example 1. After the resulting partially oriented fibers were stored for 90 days in an atmosphere of 35 ° C and 60% RH, they were subjected to twist processing under the same conditions as in Example 1 to obtain twisted fibers. PLA composite ratio was high, the initial tensile resistance was high, and the PLA composite ratio was increased, so that it was expected that the stretch recovery ratio would increase, but it was not high. It is considered that this is caused by the fact that the PTT composite ratio is lowered and the composite non-balance is deteriorated. The obtained fabric was inferior in softness.

Examples 14 to 15 and Comparative Example 13

The partially oriented fibers of Example 4 were stored for 90 days in an atmosphere of 35 DEG C and 60% RH, and then subjected to twist processing at the processing magnifications shown in Table 4. [ Except for the processing magnification, the same conditions as in Example 10 were used. The CV% and the stretch recovery ratio of the continuous continuous wet heat shrinkage ratio were changed by changing the processing magnification, but in Examples 14 and 15 within the specified range of the present invention, good warpage was obtained. On the other hand, in Comparative Example 13, since the CV% of the continuous wet heat shrinkage ratio was increased to 5.3%, the knitting test failed, and even in the softness evaluation, the shrinkage unevenness of the fabric was large and the initial tensile resistance was low, It became a touch and was rejected.

Examples 16 to 17 and Comparative Example 14

The partially oriented fibers of Example 4 were stored for 90 days in an atmosphere at 35 DEG C and 60% RH, and then subjected to flammability processing at the D / Y ratio shown in Table 4. [ Except for the D / Y ratio. The CV% and stretch recovery ratio of the continuous continuous wet heat shrinkage ratio were changed by changing the D / Y ratio, but in Examples 16 and 17 within the specified range of the present invention, good warpage was obtained. On the other hand, in Comparative Example 14, the stretch shrinkage ratio was insufficient at 23%, so that only a fabric with poor stretchability could be obtained.

(Industrial availability)

A partially oriented fiber and a cheese-like package preferable for large-scale production with good durability stability and soft feeling as well as a small change in the package shape over time despite the substantial long-term warehouse storage required, It is possible to provide a false-twisted fiber capable of producing a fabric with excellent quality and stable quality. Therefore, it is preferable for use in materials represented by general medical applications and vehicle interior materials. In particular, since long-term transportation is facilitated, global operation becomes possible.

1: Detention 2: Cooling unit
3: Lubrication device 4: First roller
5: second roller 6: contact roller
7: Package 8: First heating roller
9: Second heating roller

Claims (5)

Wherein the core component is a core-sheath composite fiber wherein the core component is composed of polytrimethylene terephthalate and the component thereof is polytrimethylene terephthalate, and satisfies the following requirements (1) to (3).
(1) Shinto: 60 ~ 130%
(2) 70 ° C Hot water shrinkage rate: 0.5 to 7.0%
(3) Initial tensile resistance: 20 to 40 cN / dtex The method according to claim 1,
Wherein the polylactic acid has a weight average molecular weight of 200,000 or more and 300,000 or less. 3. The method according to claim 1 or 2,
Wherein the composite ratio of the polylactic acid is 20 to 50 wt%. A polyester cheesecloth composite filament fiber according to any one of claims 1 to 3, which is wrapped and wound around the package after wrapping for 90 days in an atmosphere at 35 캜 and 60% RH, And the saddle of the cheese-shaped package satisfy the following (4) to (5).
(4) Bulge of cheese-based package: -5 to 5%
(5) Cheese-based package birds: 0-5% Wherein the core component is composed of polytrimethylene terephthalate and the core component is composed of polytrimethylene terephthalate, wherein the core-sheath composite tentatively-processed fiber satisfies the following requirements (6) to (8) .
(6) CV% of the continuous wet heat shrinkage ratio is 0 to 5%
(7) Initial tensile resistance of 20 to 40 cN / dtex
(8) Elongation recovery rate 25 ~ 60%

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