JP4537078B2 - Biodegradable polyester fiber - Google Patents

Description

  The present invention relates to a biodegradable polyester fiber excellent in process stability from yarn production to weaving and weaving processes.

  Synthetic fibers such as polyester derived from petroleum are superior to other materials in terms of strength, cost, and productivity, and are now indispensable materials in society. However, on the other hand, environmental problems on a global scale that can be said to be the merits and demerits of civilized society have been closed, and while maintaining the above characteristics of synthetic fibers, they are decomposed by microorganisms in natural environments such as cotton and silk. There has been a strong desire to develop biodegradable polymers that are rendered harmless. Particularly in Europe and the United States, fermentative decomposition by compost instead of incineration is becoming the mainstream 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.

  On the other hand, when these biodegradable polyester polymers pass through melt spinning, stretching, warping, weaving, knitting processes, etc., there are many occurrences of fluff and yarn breakage compared to aromatic polyesters such as polyethylene terephthalate, There is a problem that the passability of the process tends to be poor. The reason for this is that biodegradable polyester generally has a low melting point and thus tends to have high friction with plates and guides, and its glass transition point is lower than room temperature. It may be easy to become. Furthermore, since the oil agent applied at the time of spinning easily penetrates into the polymer, it can be considered that fluff and yarn breakage are likely to occur due to a decrease in strength due to polymer swelling.

  In order to prevent such biodegradable polyester, for example, Patent Document 1 discloses that polyorganosiloxane or mineral oil is used as a main component, ether-modified polyorganosiloxane or amino acid, in order to prevent sticking and improve the unwinding property. A straight type oil containing a modified polyorganosiloxane or silicon resin has been proposed. Certainly, with this straight oil agent, sticking can be prevented and the unraveling property can be improved. Occurs and the process passability is extremely deteriorated. In consideration of this problem, Patent Document 2 discloses anionic surfactants such as lauryl phosphate potassium salt, cationic surfactants such as quaternary ammonium salts, ethylene oxide adducts of higher aliphatic alcohols and higher fatty acids. Nonionic surfactants such as polyethylene glycol, polyalkylene glycols such as polyethylene glycol / polypropylene glycol block copolymers, silicone oils such as dimethylpolysiloxane, polyether-modified silicone oil, and higher alkoxy-modified silicone oil Or it is proposed to give 2 or more types. Surely, if oils with appropriate combination of these components are used, problems due to sticking and static electricity generation can be reduced, but it is difficult to suppress fluff generation in the stretching process, and the processability is not sufficient. It is.

  Patent Document 3 proposes a fiber in which an oil agent composed of a smoothing agent and an emulsifier is applied, and a dynamic friction coefficient between the fiber and the metal is set to 0.30 to 0.45. Certainly, this fiber has no problems due to sticking or generation of static electricity, and the dynamic friction coefficient between the fiber and metal is set to an appropriate range, so improvement in process passability in the drawing process is recognized, but the drawing speed When the speed is increased or the roller set temperature is increased, generation of fuzz becomes insufficient, and the processability after stretching tends to be poor.

  As described above, a biodegradable polyester fiber that has satisfactory process passability from spinning and drawing to post-processing such as weaving and weaving has not yet been proposed.

Japanese Patent Laid-Open No. 6-257072 Japanese Patent Laid-Open No. 9-21017 JP 2003-20567 A

  The present invention has been made against the background of the above prior art, and an object thereof is to provide a biodegradable polyester fiber excellent in process stability from yarn production to knitting and weaving processes.

  As a result of diligent study to solve such problems, the present inventor provided an oil agent containing a specific partial phosphate ester salt based on silicon or mineral oil, and determined the coefficient of static friction between the fiber and the metal within a specific range. When set to 1, the occurrence of fluff during the production of the biodegradable polyester fiber (at the time of drawing) is extremely reduced, and it has been found that the process-passing stability after drawing is improved, and the present invention has been achieved.

That is, the above problem is
“A biodegradable polyester fiber provided with an oil containing the following components (a) to (c) as essential components on the fiber surface, and the coefficient of static friction between the fiber and metal is 0.20 to 0.40. A biodegradable polyester fiber characterized by that.
(A) 50 to 98% by weight of polyorganosiloxane and / or mineral oil
(B) 1-10% by weight of polyether-modified polyorganosiloxane and / or amino-modified polyorganosiloxane
(C) a partial phosphate ester salt of a compound obtained by adding 0 to 10 moles of ethylene oxide and / or propylene oxide to an alcohol having 8 to 18 carbon atoms , which is a secondary amine salt or a tertiary amine salt 1-10% by weight of phosphate ester salt "
Has been found to be achieved.

  According to the biodegradable polyester fiber of the present invention, not only the generation of fuzz at the time of spinning and drawing is suppressed, but also troubles due to sticking in the post-processing step until weaving are suppressed. Can provide excellent fiber products with good productivity

  Examples of the biodegradable polyester targeted by the present invention include polyhydroxyalkylates (PHA) such as polyhydroxybutyrate, polyglycolic acid and polylactic acid, polylactones (PL) such as polycaprolactone and polypivalolactone, poly Butylene succinate (PBS), polyethylene succinate (PES), copolymer of polybutylene succinate and polyethylene succinate, polyethylene adipate, polybutylene adipate, polyhexylene adipate, polydecylene adipate, polyethylene sebacate, polybutylene Examples include polyesters such as polyalkylene alkylates (PAA) obtained from aliphatic diols such as sebacate, polyhexylene sebacate, polydecylene sebacate and aliphatic dicarboxylic acids. That. Furthermore, a block and / or random copolymer polyester containing 70% by weight or more of components derived from these polymerization raw materials, and in addition to the polyester component, for example, a polyether component, a polycarbonate component, a polyamide component, a polyurethane component, Polyorganosiloxane components etc. blocked or random copolymerized at a ratio of 30% by weight or less, or those obtained by mixing polyether, polycarbonate, polyamide, polyurethane, polyorganosiloxane, etc. at a ratio of 30% by weight or less with the polyester And so on.

  Also, in order to adjust the alkali weight loss rate or improve the adhesion at the polymer interface, 5-metal sulfoisophthalic acid, polyethylene glycol, polypropylene glycol, pentaerythritol, glycidyl ether having an alkylene oxide block, etc. are used as the third component. Polymerization may be performed.

  In the present invention, the melting point of the biodegradable polyester is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, from the viewpoint of heat resistance. Especially preferably, it is 200 degreeC or more. The upper limit is preferably as high as possible, so there is no need to specifically limit it.

  Next, the oil used in the present invention is applied at the time of spinning in order to suppress the occurrence of fuzz and yarn breakage in the process from the yarn production to the weaving and weaving process, and to achieve extremely excellent process passability.

  First, the polyorganosiloxane and / or mineral oil which is the component (a) of the oil agent reduces the adhesiveness and frictional resistance of the fibers and prevents sticking between the fibers, and is further a component (b) described later. It is used as an agent for dissolving a polyether-modified polyorganosiloxane or an amino-modified polyorganosiloxane. The polyorganosiloxane here means a polyorganosiloxane that is not substantially modified, and specifically, polydimethylsiloxane can be exemplified as a preferable one. The viscosity is 5 to 100 centistokes (hereinafter abbreviated as cst), preferably 5 to 50 cst. As the mineral oil, those having a viscosity in the range of 5 to 100 cst, preferably 5 to 50 cst are suitable.

  The proportion by weight (as a non-aqueous component) of the polyorganosiloxane and / or mineral oil in the oil must be 50 to 98% by weight, preferably 60 to 95% by weight. When the weight ratio is less than 50% by weight, the smoothness is insufficient, and fluff and yarn breakage are likely to occur due to rubbing with the yarn guide. On the other hand, when it exceeds 98% by weight, the ratio of at least one of the components (b) and (c) described later is reduced, and the occurrence of fluff due to the prevention of sticking and the decrease in oil film strength during yarn production (during stretching). It becomes difficult to prevent troubles caused by static electricity.

  Next, the amino-modified polyorganosiloxane used as the component (b) is obtained by introducing an amino group into polyorganosiloxane. The modification site of the amino group may be a side chain or a main chain. The amino equivalent of amino-modified polyorganosiloxane (average molecular weight of amino-modified polyorganosiloxane / average number of amino groups per molecule) tends to be too difficult to wind if the amino equivalent is too small, resulting in too high smoothness. On the other hand, if it becomes too large, the effect of improving the anti-sticking performance is reduced, so the range of 600 to 3000 is appropriate. The viscosity of the amino-modified polyorganosiloxane is suitably 5 to 1000 cst, particularly 20 to 500 cst.

  As another example of the polyether-modified polyorganosiloxane used as the component (b), dimethylpolysiloxane having a polyether chain introduced can be mentioned, but the methyl group is another alkyl group or aryl group. May be substituted. As the polyether chain, a polyalkylene oxide chain obtained by (co) polymerizing propylene oxide and / or ethylene oxide is preferable, and when copolymerized, block copolymerization or random copolymerization may be used. The modified part of the polyether chain may be a side chain or a main chain of the polyorganosiloxane. The degree of polymerization of these alkylene oxides is suitably in the range of 10-50. If it is less than 10, the difference from the polyorganosiloxane is small, and the effect of improving the anti-sticking performance is small. The viscosity of the polyether-modified polyorganosiloxane is also in the range of 5 to 1000 cst, particularly 20 to 500 cst.

  The weight ratio (as a non-aqueous component) of the amino-modified polyorganosiloxane and / or polyether-modified polyorganosiloxane in the oil agent needs to be in the range of 1 to 10% by weight, particularly 2 to 8% by weight. . When the weight ratio is less than 1% by weight, the anti-sticking performance is insufficient. On the other hand, when it exceeds 10% by weight, the smoothness is lowered and it becomes difficult to prevent the occurrence of fluff and yarn breakage.

  Next, the partial phosphate ester salt of a compound obtained by adding 0 to 10 moles of ethylene oxide and / or propylene oxide to an alcohol having 8 to 18 carbon atoms, used as component (c), only suppresses the generation of frictional static electricity. No, it is used to reduce the occurrence of fluff during yarn production (during stretching) by lowering the coefficient of static friction between the fiber and metal.

  Such a partial phosphate ester salt is a salt obtained by adding a predetermined amount of ethylene oxide and / or propylene oxide to a predetermined alcohol and then converting it to phosphoric ester, followed by neutralization with an alkali or amine. The alcohol needs to be an alcohol having 8 to 18 carbon atoms, and examples thereof include caprylyl alcohol, capryl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, and branched alcohols thereof. In particular, branched alcohols are preferred from the viewpoint of compatibility with polyorganosiloxane, amino-modified polyorganosiloxane, polyether-modified polyorganosiloxane (hereinafter sometimes collectively referred to as silicone) and mineral oil. The number of moles of ethylene oxide and / or propylene oxide needs to be 0 to 10 moles, and is preferably in the range of 2 to 8 moles from the viewpoint of compatibility with silicone and mineral oil. Here, when the number of added moles exceeds 10 moles, the static electricity suppressing effect is lowered, which is not preferable.

  The ratio of partial phosphoric esterification (the ratio of esterification) is suitably in the range of 1.0 to 1.6, particularly preferably in the range of 1.0 to 1.3. Here, the ratio of esterification of 1 means a phosphoric acid monoester, 2 means a diester, and 3 means a triester.

  Examples of the salt obtained by neutralizing the partial phosphate ester include alkali metal salts and amine salts. Here, examples of the alkali metal include sodium, potassium, and lithium, while examples of the amine include secondary amines such as diethylamine, dipropylamine, dibutylamine, and dioctylamine, and tertiary amines. And triethylamine, tripropylamine, tributylamine, trioctylamine and the like. Among these, a secondary amine salt or a tertiary amine salt is preferable. Such an amine salt can lower the coefficient of static friction between the fiber and the metal, and even if the oil agent is used in a non-aqueous system, it is possible to obtain a uniform oil agent with good compatibility of each component of the oil agent.

  The weight ratio (as a non-aqueous component) of such a partial phosphate ester salt in the oil must be in the range of 1 to 10% by weight, particularly 2 to 8% by weight. When the weight ratio is less than 1% by weight, the oil film strength decreases, the smoothness between the metal and the fiber decreases, and it becomes difficult not only to prevent the occurrence of fluff and yarn breakage, but also troubles caused by static electricity. It cannot be prevented. On the other hand, when it exceeds 10% by weight, the smoothness is lowered and it becomes difficult to prevent the occurrence of fluff and yarn breakage.

  In the present invention, in addition to the requirements described above, it is important to set the coefficient of static friction between the fibers and the metal in the range of 0.20 to 0.40. Since biodegradable polyester fiber is generally lower in strength than ordinary polyester fiber such as polyethylene terephthalate fiber, fluff and yarn breakage are likely to occur due to friction with guides and rollers during yarn drawing. Although it is important to reduce the smoothness (fiber-metal dynamic friction coefficient) of the applied oil, according to the study of the present inventors, even if the smoothness is good, the fiber-metal static friction coefficient is If it is high, the stretchability becomes poor and it is difficult to suppress the fluff, and it has been found that the occurrence of fluff can be significantly improved by setting the fiber-metal static friction coefficient in the range of 0.20 to 0.40.

  In order to set the fiber-metal static friction coefficient within the above range, for example, the type and ratio of the component (c) can be appropriately selected. Although the reason is not clear, the partial phosphate ester salt which is the component (c) in the oil agent is adsorbed to the stretching roller, the friction between the roller and the fiber is reduced, and the oil agent layer on the fiber is hardly destroyed. It is estimated that.

  The oil used in the present invention contains the above components (a) to (c) as essential components, but other components such as ester-based smoothing agents, nonionic surfactants, if necessary, Anionic surfactants, antioxidants, compatibilizers, stability improvers and the like may be added within a range that does not impair the object of the present invention.

  In order to adhere the oil agent described above to the biodegradable polyester fiber, an emulsion emulsified in water may be used, or the stock solution may be used as it is, and any method can be adopted. In particular, the method of using the stock solution as it is (straight type treatment), the emulsifier that is usually used together to make an emulsion easily swells the fiber, so it is easy to generate scum. This is preferable because it has the advantage of eliminating.

  For the application of the oil to the biodegradable polyester fiber, any conventionally known means can be adopted, and among them, a method of applying a measured amount through an oiling nozzle that reduces resistance given to the yarn is preferable. .

  The adhesion amount of the oil agent (non-aqueous component) to the fiber is suitably 0.3 to 3.0% by weight, preferably 0.5 to 2.0% by weight based on the fiber weight. When the adhesion amount is less than 0.3% by weight, the smoothness and antistatic property are lowered, and troubles such as fluff, yarn breakage, and scum are likely to occur. On the other hand, even if it exceeds 3.0% by weight, the effect of suppressing the occurrence of fluff, yarn breakage, and scum is small, and on the contrary, excessive oil agent will contaminate the yarn guide and the like, causing a new problem. It is not industrially profitable.

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) Amount of oil agent (OPU)
Immediately after drying about 3 g of a drawn yarn sample made of biodegradable polyester at 105 ° C. for 2 hours, the weight (A) is measured, and then immersed in 300 cc of an aqueous cleaning solution containing 0.5% by weight of sodium alkylbenzenesulfonate. Apply ultrasound at 40 ° C. for at least 10 minutes. Discard the cleaning solution, wash with running water at 40 ° C. for 30 minutes, and air dry at room temperature. Thereafter, the weight (B) is measured immediately after drying at 105 ° C. for 2 hours, and OPU is calculated from the following equation.
OPU% = (A−B) / B × 100

(2) Dynamic friction between yarn and metal contact body Using a drawn yarn sample made of biodegradable polyester, using a fiber / metal running friction measuring machine, using a satin chrome pin with a diameter of 60 mm as a friction body at a running speed of 300 m / min. The friction body exit side tension (T1) was measured at a contact angle of 180 degrees and a friction body entrance side tension of 10 g (T1). The inter-filament friction coefficient (f) is calculated from the following well-known equation regarding the friction of the belt running on the cylinder.
f = (1 / π) × ln (T2 / T1)

(3) Static friction between yarn and metal contact body Using a drawn yarn sample made of biodegradable polyester, a satin chrome pin having a diameter of 60 mm as a friction body at a running speed of 0.1 m / min with a fiber-metal running friction measuring machine. Using this, 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 30 g (T'1), and the coefficient of friction was calculated using the equation described in the dynamic friction between yarn and metal. .
f = (1 / π) × ln (T′2 / T′1)

(4) Number of Fluffs Using a drawn yarn sample made of biodegradable polyester, the number of fluffs per million m was determined by measuring with a fluff tester.

(5) Adhesion When a drawn yarn sample made of biodegradable polyester was unwound at 300 m / min, fluctuations in the unwinding tension due to agglutination were observed with a recorder to confirm the presence or absence of agglutination.

[Example 1]
A block copolymer (melting point: 230 ° C.) obtained by transesterification of polyethylene terephthalate and polycaprolactone was melted and discharged at a temperature of 240 ° C. to form 16 filament yarns. After solidifying the yarn, 1.2% by weight (non-aqueous component) of the oil agent shown in Table 1 is applied based on the fiber weight through a measuring oiling nozzle, and then through a take-up roller having a surface speed of 1000 m / min. Subsequently, the film was drawn 2.7 times between the take-up roller and the drawing roller to obtain a drawn yarn of 110 dtex / 16 filament. The strength of the drawn yarn was 2.06 cN / dtex. The evaluation results are also shown in Table 1.

  Since the biodegradable polyester fiber of the present invention is of high quality with excellent smoothness and good stretchability, and also suppressed generation of fluff, the process stability of post-processing steps such as knitting and weaving is excellent. Improved, its industrial value is extremely great.

Claims (3)

A biodegradable polyester fiber provided with an oil containing the following components (a) to (c) as essential components on the fiber surface, and the coefficient of static friction between the fiber and metal is 0.20 to 0.40. Biodegradable polyester fiber characterized by
(A) 50 to 98% by weight of polyorganosiloxane and / or mineral oil
(B) 1-10% by weight of polyether-modified polyorganosiloxane and / or amino-modified polyorganosiloxane
(C) a partial phosphate ester salt of a compound obtained by adding 0 to 10 moles of ethylene oxide and / or propylene oxide to an alcohol having 8 to 18 carbon atoms , which is a secondary amine salt or a tertiary amine salt 1-10% by weight of phosphate ester salt The biodegradable polyester fiber according to claim 1 , wherein the ratio of esterification of the partial phosphate ester salt of component (c) is in the range of 1.0 to 1.6 .   The biodegradable polyester fiber according to claim 1 or 2, wherein an adhesion amount of the oil agent is 0.3 to 3.0% by weight based on the fiber weight.