JP2007321320A - Biodegradable polyester fiber for false twist processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable polyester fiber for false twist processing, causing very little fluff and yarn break when the biodegradable polyester fiber is subjected to the false twist processing, and also having excellent process-passing stability after the false twist processing. <P>SOLUTION: The biodegradable polyester fiber with imparted oil is characterized by the oil containing 50-80 wt.% aliphatic ester compound component having 250-550 molecular weight and 1-20 wt.% PO/EO copolymer component of a PO/EO copolymer obtained by adding propylene oxide (PO) and ethylene oxide (EO) to a polyhydric alcohol and substantially blocking the whole terminals with a 1-12C alkyl groups, and having 2,000-10,000 average molecular weight, and the fiber-metal dynamic friction coefficient of 0.2-0.35 and fiber-fiber static friction coefficient of 0.2-0.35. Preferably, the oil is an aqueous emulsion, and the attached amount of the oil is 0.2-1.0 wt.% based on the fiber weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biodegradable polyester, and more particularly, to a biodegradable polyester for false twisting that is excellent in passage through an intermediate process after the false twist process.

  Synthetic fibers such as polyester are superior to other materials in terms of strength, cost, and productivity, and are now indispensable materials in society. However, in terms of environmental issues on a global scale, there is a strong development of biodegradable polymers that maintain the above characteristics of synthetic fibers and that are degraded and harmless by microorganisms in the natural environment, such as cotton and silk. It has been desired. Fermentative decomposition by compost instead of incineration has attracted attention as a method for treating organic waste, and it is considered that biodegradability at the compost level will be required for general-purpose synthetic fibers in the future.

  As such materials, aliphatic polyesters that consist of oxygen, hydrogen, and carbon as constituent atoms and decompose to produce only water and carbon dioxide have potentially low environmental impact biodegradability. Are known. In particular, microbially produced poly-hydroxybutyric acid esters and synthetic polymer poly-ε-caprolactone, polyethylene adipate, polyglycolic acid and poly-L-lactic acid have been developed as representative biodegradable polyesters. It has been commercialized.

  However, when these biodegradable polyester fibers are used as false twisted yarn, when passing through the drawing stage, false twisting process, warping, weaving, knitting process, etc. Compared with aromatic polyesters such as terephthalate, there were many occurrences of fluff and yarn breakage, and there was a problem that processability was likely to be poor. In particular, when friction false twisting is used, fluff and yarn breakage tend to increase further due to rubbing with the false twisting urethane and ceramic desk.

At present, for example, Patent Document 1 discloses a polyether-based polymer active agent-containing oil agent having a molecular weight of 1000 to 5000 as a surfactant bond and a biodegradable polyester fiber having a saturation bond between a smoothing agent component and an activator component as main components of an oil agent. It is disclosed. However, this oil agent has a problem that it has high permeability to fibers and easily induces fluff and yarn breakage due to strength reduction due to polymer swelling. Therefore, as a technique for reducing the permeability, Patent Document 2 discloses a method in which the average HLB value (hydrophilic / lipophilic balance) of the oil agent is 9 or less. However, this method has a problem that there are many restrictions on the surfactant that can be used in the oil, and there is a problem that it is not possible to sufficiently prevent fuzz and yarn breakage.
As described above, none of the biodegradable polyester fibers disclosed so far has very few fuzz and breakage in the friction false twisting process and can satisfy the process passability.

JP 2005-29902 A JP 2004-27374 A

  The present invention has been made paying attention to the above-mentioned problems, and its purpose is that the occurrence of fluff and yarn breakage when false-twisting biodegradable polyester fiber is extremely small, An object of the present invention is to provide a biodegradable polyester fiber for false twisting which is excellent in process passage stability.

The biodegradable polyester fiber for false twisting of the present invention is a biodegradable polyester fiber provided with an oil agent, and the oil agent contains 50 to 80% by weight of the following component (a) and 1 to 1 component (b). The fiber-metal dynamic friction coefficient is 0.2 to 0.35, and the fiber-fiber static friction coefficient is 0.2 to 0.35.
(A) an aliphatic ester compound having a molecular weight of 250 to 550 (b) a PO / EO copolymer obtained by adding propylene oxide (PO) and ethylene oxide (EO) to a polyhydric alcohol, and having an average molecular weight of 2000 to 10,000 In addition, a PO / EO copolymer in which substantially all terminals are ether-blocked with an alkyl group having 1 to 12 carbon atoms. Further, the oil agent is an aqueous emulsion, and the amount of oil agent attached is based on the fiber weight. Is preferably 0.2 to 1.0% by weight.

  According to the present invention, biodegradable polyester fibers for false twisting that have extremely low generation of fluff and breakage when falsely twisted biodegradable polyester fibers and are excellent in process passage stability after false twisting. Is provided.

  The biodegradable polyester fiber provided with the oil agent of the present invention is not particularly limited as long as it is a polyester-based fiber that can be fermented and decomposed in soil, but more specifically, for example, polyhydroxybutyrate, Polyglycolic acid, polyhydroxyalkylate (PHA) such as polylactic acid, polylactone (PL) such as polycaprolactone, polypivalolactone, polybutylene succinate (PBS), polyethylene succinate (PES) and polybutylene succinate Polyethylene succinate copolymer, polyethylene adipate, polybutylene adipate, polyhexane adipate, polydecane adipate, polyethylene sebacate, polybutylene sebacate, polyhexane sebacate, polydecane sebacate, etc. In addition to the polyester block and / or random copolymer having a component derived from a polyester polymerization raw material such as polyalkylene alkylate (PAA) obtained from 70% by weight or more, and the polyester component, for example, aromatic polyester, poly Examples include ethers, polycarbonates, polyamides, polyurethanes, polyorganosiloxanes and the like that are 30% by weight or less of block or random copolymerization and / or mixtures thereof. Among these, the biodegradable polyester fiber is preferably an aliphatic polyester or a polylactic acid fiber.

  In addition to the above components, a small amount of a third component may be copolymerized in order to adjust the alkali weight loss rate or improve the adhesion at the polymer interface. As the third component, for example, 5-metal sulfoisophthalic acid, polyethylene glycol, polypropylene glycol, pentaerythritol, glycidyl ether having an alkylene oxide block, or the like can be used.

  In the present invention, the melting point of the biodegradable polymer as described above is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, from the viewpoint of heat resistance. More preferably, it is 200 degreeC or more.

The present invention is a fiber in which an oil agent is added to such a biodegradable polyester fiber. As an oil agent, an end-capped PO / EO copolymer in which 50 to 80% by weight of the following component (a), which is an aliphatic ester compound, is added with propylene oxide (PO) and ethylene oxide (EO) to a polyhydric alcohol. It is essential to contain 1 to 20% by weight of the following component (b).
(A) an aliphatic ester compound having a molecular weight of 250 to 550 (b) a PO / EO copolymer obtained by adding propylene oxide (PO) and ethylene oxide (EO) to a polyhydric alcohol, and having an average molecular weight of 2000 to 10,000 And a PO / EO copolymer in which substantially all ends are ether-blocked with an alkyl group having 1 to 12 carbon atoms

  By applying such an oil agent, for example, at the time of spinning, it is possible to obtain excellent process passability with very little fuzz and yarn breakage in the processes from spinning to weaving and knitting.

  Further, each oil agent component will be described. As the aliphatic ester compound as component (a), a fatty acid monoalkyl ester, an aliphatic dicarboxylic acid dialkyl ester, a mono- or multi-fatty acid ester of an aliphatic polyhydric alcohol, and the like have a molecular weight. The thing of the range of 250-550 is preferable. When the molecular weight of the ester is less than 250, the smoothness of the biodegradable fiber obtained tends to decrease because it is easily volatilized by heat. On the other hand, if it exceeds 550, the smoothness of the resulting biodegradable fiber becomes insufficient, such being undesirable. Examples of aliphatic esters preferably used include fatty acid monoalkyl esters such as octyl octanoate, octyl stearate, isotridecyl laurate, isotridecyl oleate, lauryl oleate, and the like, and aliphatic dicarboxylic acid dialkyl esters. Examples thereof include diisooctyl adipate. Examples of mono- or multi-fatty acid esters of aliphatic polyhydric alcohols include trimethylolpropane trioctanoate. Among these, fatty acid monoalkyl esters are preferred. By using such component (a), it is possible to reduce the frictional resistance and suppress the generation of fluff due to scratching.

  The content ratio of the aliphatic ester to the oil agent is 50 to 80% by weight. When the content ratio is less than 50% by weight, the smoothness is inferior and the smoothness due to rubbing with the yarn guide is inferior. When the content ratio exceeds 80% by weight, the ratio of the emulsifier component decreases, particularly when used in an aqueous emulsion. It becomes difficult to obtain a stable aqueous emulsion.

  Next, the end-capped PO / EO copolymer in which propylene oxide (PO) and ethylene oxide (EO) are added to the polyhydric alcohol as the component (b) will be described. As the polyhydric alcohol to which PO / EO is added, Examples include diethylene glycol, glycerin, trimethylolpropane, sorbitan, and sorbitol. As the PO and EO added to the alcohol, either random or block polymerization can be used. The most important point in the present invention is that the terminal OH of this polyhydric alcohol PO / EO copolymer is all ether-bonded with an alkyl group having 1 to 12 carbon atoms. Furthermore, the blocked alkyl group is preferably selected from a methyl group, an ethyl group, a propyl group, and a butyl group.

  By using such an end-capped polyhydric alcohol PO / EO copolymer as an oil agent, in the present invention, fibers can be easily entangled during false twisting, and the generation of fluff is extremely reduced. This is particularly effective in friction false twisting. Furthermore, by using this (b) component, there exists an effect which does not swell a biodegradable polymer by suppressing the hydrophilic property of an oil agent. It also has the effect of reducing the inter-fiber static friction.

  In general, when a hydrophilic PO / EO copolymer-containing oil agent is added to a biodegradable polyester fiber, the oil agent easily penetrates into the inside of the fiber, and the polymer swells to reduce the strength of the fiber. The problem that it is easy to induce is generated. However, in the present invention, the PO / EO copolymer in which all of the terminal OHs are blocked with alkyl groups is essential, thereby preventing the polymer from swelling and ensuring the fluff resistance.

  In the present invention, the content of the component (b), which is a PO / EO copolymer blocked with an alkyl group, in the oil must be 1 to 20% by weight, preferably 3 to 15% by weight. . When the content is less than 1% by weight, the effect of reducing friction is not sufficient, and single yarn breakage tends to occur. On the other hand, if it exceeds 20% by weight, the static friction between the fibers tends to be excessively reduced.

  The oil agent used in the present invention contains the above components (a) and (b) as main components, but if necessary, other components, for example, nonionic surfactants that are emulsifiers for ester components Agents, antistatic anionic surfactants, antioxidants, compatibilizers, and stability improvers may be added within a range that does not impair the object of the present invention.

  The biodegradable polyester fiber of the present invention is a biodegradable fiber to which an oil containing the essential components (a) and (b) described above is applied, and has a fiber-metal dynamic friction coefficient of 0.2 to 0.00. 35. It is important that the fiber-fiber static friction coefficient is in the range of 0.2 to 0.35. Since biodegradable fibers have a lower melting point than ordinary polyester fibers, friction with the heater plate and guides is likely to increase due to thermal melting of the fibers, which may cause fluff and yarn breakage. Therefore, it is important to reduce the smoothness (fiber-metal dynamic friction coefficient) of the oil applied to the fiber. However, even if the smoothness is simply good, in the case of false twisting, especially in the case of friction false twisting, if the fiber-fiber static friction coefficient is high, the generation of fluff is caused by the friction between the fibers during twisting. According to our research, it was found that the fluff can be greatly improved by setting the fiber-fiber static friction coefficient in the range of 0.2 to 0.35. When such an oil agent of the present invention is used, the occurrence of fluff and yarn breakage is extremely small until the knitting and weaving process after the false twisting process, and the fiber is excellent in process stabilization.

  In order to attach such an oil agent to the biodegradable fiber, the stock solution may be used as it is, but it is preferable to use an emulsion emulsified in water. (B) component used by this invention has hydrophilic ethylene oxide, and when it is emulsified in water, the effect can be exhibited more. In the case of non-aqueous oils, it is difficult to improve the compatibility with esters other than polyethers and ether ester components, the stability of the oils deteriorates, and it is difficult to uniformly apply the oils to the fibers. Tending to be difficult.

  Generally, any generally known means can be used to apply the oil agent to the biodegradable fiber. Among them, a method of applying a measured amount through an oiling nozzle that reduces resistance to the yarn is more preferable. This is the preferred method.

  The amount of the oil agent attached to the biodegradable fiber is preferably 0.2 to 1.0% by weight as an active ingredient with respect to the fiber. When the adhesion amount is less than 0.2% by weight, the smoothness and antistatic property are insufficient and tend to cause troubles such as fluff, yarn breakage, and scum. On the other hand, even if it exceeds 1.0% by weight, there is little improvement in the effect of suppressing the occurrence of fluff, yarn breakage, and scum, and conversely, excessive oil agent will contaminate the yarn guide and the like, causing new problems. It is not industrially profitable.

  Such a biodegradable polyester fiber for false twisting according to the present invention has little fuzz generation in the false twisting process, has excellent process passage stability after the false twisting process, and is widely used in conventional false twisting. It can be used as a fiber substitute. In particular, the biodegradable polyester fiber for false twisting of the present invention is effective in friction false twisting, and can effectively reduce fuzz and yarn breakage due to rubbing with false twisting urethane and ceramic desks. is there.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the measured value in an Example was measured with the following method.

(1) OPU measurement method Immediately after drying 3 g of drawn yarn composed of biodegradable fibers of 83 dtex / 36 filaments at 105 ° C. × 2 hours, the weight (A) is measured, and an aqueous cleaning solution mainly composed of sodium alkylbenzenesulfonate. Immerse in 300 cm 3 and apply ultrasonic waves at 40 ° C. for at least 10 minutes. The washing solution is discarded, washed with running water at 40 ° C. for 30 minutes, and then air-dried at room temperature. Thereafter, the weight (B) is measured immediately after drying at 105 ° C. for 2 hours.
OPU% = (A−B) / B × 100
OPU is calculated from the above equation.

(2) Fiber-metal dynamic friction coefficient Using a drawn yarn made of biodegradable fibers of 83 dtex / 36 filaments, a satin chrome pin having a diameter of 60 mm as a friction body at a running speed of 300 m / min with a fiber-metal running friction measuring machine (surface Using the roughness 6s), the friction body exit side tension (T ₂ ) was measured at a contact angle of 180 degrees and a friction body entry side tension of 10 g (T ₁ ). The fiber-metal dynamic friction coefficient (μ ₁ ) was calculated from the following equation regarding the friction of the belt running on the cylinder.
μ ₁ = 1 / π × ln (T ₂ / T ₁ )

(3) Fiber-fiber static friction coefficient A multifilament yarn is wound around a cylinder in the front-rear direction at a spiral angle of ± 15 ° with a winding tension of 9.8 cN (about 10 g). The cylinder has a diameter of 5.1 cm (2 inches) and a length of 7.6 cm (3 inches). The multifilament yarn is hung on another 30.5 cm (12 inches) on the cylinder on which the multifilament yarn has been wound beforehand. At this time, the multifilament yarn applied later is placed on the upper layer portion of the multifilament yarn previously wound around the cylinder and is parallel to the winding direction. A load (unit: g) 0.04 times the fineness (unit: dtex) of the multifilament yarn is applied to one end of the multifilament yarn applied later, and a strain gauge is connected to the other end. The cylinder is rotated 180 degrees at a peripheral speed of 0.0016 cm / sec, and the tension at that time is continuously recorded. The filament-filament static friction coefficient (f) was calculated from the following equation regarding the friction of the belt running on the cylinder.
f = (1 / π) · (ln (T ₂ / T ₁ ))
Here, T ₂ is an average value of peak tension (n = 25), T ₁ is a tension applied by a load applied to one end of the multifilament yarn, and ln is a natural logarithm symbol.

(4) Number of fluff The stretched yarn of biodegradable fiber 83 dtex / 36 filament was measured with a fluff tester to determine the number of fluff per million m.

(5) Generation of white powder When processed for 3 consecutive days under the false twisting conditions in the examples, the scum adhering to the urethane disk and the guide was evaluated in three stages: ○, Δ, and ×.
○: Almost no occurrence of scum Δ: Some occurrence of scum ×: Very much scum

[Examples 1-3, Comparative Examples 1-3]
A block copolymer (melting point: 230 ° C.) obtained by transesterifying polyethylene terephthalate and polycaprolactone was melted and discharged from a spinneret having 36 discharge holes, and the discharged yarn was cooled and solidified at a rate of 3100 m / min. At the time of take-up, each of the treatment agents shown in Table 1 was attached to the cooled solidified yarn with an aqueous emulsion (emulsion concentration 10% by weight) attached so that the amount of the pure component deposited was 0.40% by weight. The resulting round cross-section 138 dtex / 36 filament unstretched multifilament yarn was drawn using a urethane circumscribed friction false twisting device equipped with a 45 mm diameter disk, a draw ratio of 1.65, a heater temperature of 150 ° C., and a friction circle. False twisting was performed while drawing at a plate rotation number of 4690 rpm and a processing speed of 600 m / min to obtain a false twisted yarn of 83 dtex / 36 filament. The results are also shown in Table 1.

Claims (3)

A biodegradable polyester fiber provided with an oil agent, the oil agent containing 50 to 80 wt% of the following component (a), 1 to 20 wt% of the component (b), and a fiber-metal dynamic friction coefficient of 0 A biodegradable polyester fiber for false twisting, having a fiber-fiber static friction coefficient of 0.2 to 0.35.
(A) an aliphatic ester compound having a molecular weight of 250 to 550 (b) a PO / EO copolymer obtained by adding propylene oxide (PO) and ethylene oxide (EO) to a polyhydric alcohol, and having an average molecular weight of 2000 to 10,000 And a PO / EO copolymer in which substantially all ends are ether-blocked with an alkyl group having 1 to 12 carbon atoms   The biodegradable polyester fiber for false twisting according to claim 1, wherein the oil agent is an aqueous emulsion.   The biodegradable polyester fiber for false twisting according to claim 1 or 2, wherein the adhesion amount of the oil agent is 0.2 to 1.0% by weight based on the fiber weight.