JP2006144137A - Polylactic acid fiber structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polylactic acid fiber structure that exhibits sufficient deodorizing properties and antimicrobial properties even in a room, has excellent persistency and durability in the functions and deodorizing properties of especially ammonia. <P>SOLUTION: The polylactic acid fiber structure comprises a polylactic acid fiber as a main component containing 0.1-7% by mass of a deodorizer composed of a maleic anhydride-based copolymer having a specific structural unit as an active ingredient and has ≥80% deodorization ratio of ammonia. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly relates to a polylactic acid fiber structure having effective deodorant and antibacterial properties against odors such as body odor and room odor.

  Aromatic polyester fibers such as polyethylene terephthalate are excellent in mechanical properties, various fastnesses, and wash and wear properties, and thus are used in various fields including clothing. On the other hand, with increasing interest in environmental issues in recent years, aromatic polyesters are not easily decomposed in a natural environment, so that an alternative to biodegradable materials has been required from the viewpoint of environmental protection. In addition, the depletion of petroleum resources is regarded as a problem, and there is a trend to reduce the amount of aromatic polyester and the like using petroleum as a raw material.

  Polylactic acid fibers, on the other hand, use corn and other plants as raw materials to save petroleum resources, and because of their excellent biodegradability and mechanical properties, they are being used in various fields and require dyeing. It has begun to be deployed in clothing applications.

In addition, the market for deodorant and antibacterial products is expanding due to the recent increase in consumer health and cleanliness, and several deodorant and antibacterial fibers using biodegradable materials have been proposed.
As one of them, an antibacterial fiber structure using polylactic acid fibers has been proposed (see, for example, Patent Document 1). However, in this case, although it has antibacterial properties derived from polylactic acid itself but does not have deodorizing properties, it can suppress the generation of odor, but it does not remove the odor once attached. I can't.

  As another method, an aliphatic polyester fiber structure having a composite oxide containing titanium and a binder resin on the fiber surface has been proposed (for example, see Patent Document 2). However, the deodorization method and the antibacterial method using such a photocatalyst are insufficient in immediate effect, and the performance is not sufficiently exhibited with the light amount of a normal fluorescent lamp. There was a problem that the effect could not be obtained.

  Furthermore, antibacterial activated carbon sheets made of activated carbon and polylactic acid fibers (for example, see Patent Document 3) and biodegradable fibers containing charcoal fine particles (for example, see Patent Document 4) have been proposed. In addition to the fibers themselves being colored by, etc., in such a deodorizing method by physical adsorption, the amount of adsorption is saturated at a certain level, so the sustainability of the effect is insufficient, and by washing etc. Since the desorption of adsorbed components is not sufficient, there is a problem in sustainability in repeated use.

JP 2000-248442 A JP 2002-69839 A Japanese Patent Laid-Open No. 2001-333773 JP 2002-249923 A

  The present invention is a fiber structure that exhibits sufficient deodorant and antibacterial properties even in a room and is excellent in the durability and durability of its function, and is particularly characterized by excellent deodorization of ammonia. A polylactic acid fiber structure is provided.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that polylactic acid containing a deodorant containing a copolymer having structural units of the following formulas (1) and (2) as an active ingredient The present inventors have found that a fiber structure using fibers has excellent deodorizing properties and antibacterial properties, and have reached the present invention.
That is, the present invention has the following contents.
(A) Mainly composed of polylactic acid fiber containing 0.1 to 7% by mass of a deodorant comprising, as an active ingredient, a maleic anhydride copolymer having structural units of the following formulas (1) and (2), A polylactic acid fiber structure characterized by having a deodorization rate with respect to ammonia of 80% or more.

(In the formula, R ₁ is hydrogen or a methyl group, R ₂ is a methoxy group, a methyl group, or a vinyl group. However, when R ₂ is a methoxy group, R ₁ is not hydrogen)

  The fiber structure of the present invention has a deodorant and antibacterial property excellent in durability and durability due to the above configuration, and is used for interior use such as curtains and carpets, table cloths, towels, draining bags, etc. It can be suitably used for daily necessities / life-related materials, underwear, socks clothing, medical / sanitary materials, etc.

Hereinafter, the present invention will be described in detail.
The polylactic acid fiber structure of the present invention is a fiber structure mainly composed of polylactic acid fibers containing a maleic anhydride copolymer having a specific structural unit as a deodorant. In the present invention, the polylactic acid fiber means a fiber composed of a polylactic acid polymer as a main component.

  Examples of the polylactic acid polymer used in the present invention include poly-D-lactic acid, poly-L-lactic acid, a copolymer of D-lactic acid and L-lactic acid, a copolymer of D-lactic acid and hydroxycarboxylic acid, Examples thereof include a copolymer of L-lactic acid and hydroxycarboxylic acid, a copolymer of D-lactic acid, L-lactic acid, and hydroxycarboxylic acid.

  When a copolymer of D-lactic acid and L-lactic acid is used as the polylactic acid-based polymer, the copolymerization ratio of the polymer components may be determined in consideration of practicality and melting point. Is preferably 90/10 to 100/0, or preferably 0/100 to 10/90.

  Examples of the hydroxycarboxylic acid when the polylactic acid polymer is a copolymer of lactic acid and hydroxycarboxylic acid include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, hydroxy Examples include octanoic acid. Among these, it is preferable to use hydroxycaproic acid or glycolic acid.

  As the polylactic acid polymer used in the present invention, poly-L-lactic acid mainly composed of L-lactic acid and poly-D-lactic acid mainly composed of D-lactic acid are mixed in a solution state or a molten state. A polylactic acid stereocomplex that can be formed by producing a stereospecific bond between these two components may be used.

  Furthermore, the polylactic acid polymer in the present invention has a number average molecular weight of preferably from 50,000 to 100,000, more preferably from 60,000 to 80,000, in order to improve physical properties such as fiber strength. When the number average molecular weight is lower than 50,000, the strength properties of the fiber are lowered, which is not preferable. On the other hand, if it exceeds 100,000, the melt viscosity becomes too high and melt spinning becomes difficult, which is not preferable.

  The polylactic acid fiber in the present invention contains a predetermined amount of a deodorant component containing, as an active ingredient, a maleic anhydride copolymer comprising a specific structural unit in the polylactic acid polymer, and is molded into a fiber shape. It will be. Such a polylactic acid fiber is prepared, for example, by preparing in advance a master chip containing a high concentration of the above deodorant component in a polylactic acid polymer, and a polylactic acid polymer chip containing no deodorant. What was melt-kneaded and adjusted the content of the deodorant component to a predetermined amount can be obtained by melt spinning by a conventional method. Alternatively, a predetermined amount of the deodorant may be directly melt kneaded and spun into a polylactic acid polymer.

  As a maleic anhydride copolymer used for this invention, it has a structural unit of following formula (1) and (2).

(In the formula, R ₁ is hydrogen or a methyl group, R ₂ is a methoxy group, a methyl group, or a vinyl group. However, when R ₂ is a methoxy group, R ₁ is not hydrogen)
Specifically, propylene / maleic anhydride copolymer, vinylethylene / maleic anhydride copolymer, methoxyisopropylene / maleic anhydride copolymer, isobutylene / maleic anhydride copolymer, vinylisopropylene / maleic anhydride An acid copolymer is mentioned. As the primary structure of these copolymers, it does not specify any of block copolymers, alternating copolymers, and random copolymers composed of the components of the formulas (1) and (2). An alternating copolymer is preferable from the viewpoint of uniformity of performance.

The molar ratio of the formula (1) and the formula (2), which are the structural units in the maleic anhydride copolymer of the present invention, is such that the maleic anhydride copolymer is melt-kneaded into a polylactic acid polymer and spinnable. And the relationship between the deodorizing properties of the resulting polylactic acid fiber fabric, and the molar ratio (formula (1) / formula (2)) between formula (1) and formula (2) is: It is preferable that it is 40 / 60-60 / 40.
The molecular weight of the maleic anhydride copolymer is 7,000 to 400,000, and particularly preferably in the range of 10,000 to 300,000.

  The polylactic acid fiber of the present invention contains 0.1 to 7% by mass of a deodorant containing the maleic anhydride copolymer as an active ingredient. Moreover, as preferable content, it is 0.3-5 mass%. When the content of the deodorant in the polylactic acid fiber is less than 0.1% by mass, the intended deodorizing effect cannot be obtained. In addition, when the content of the deodorant exceeds 7% by mass, the deodorant is not uniformly dissolved in polylactic acid, and fiberization becomes difficult.

  Furthermore, in the polylactic acid fiber of the present invention, a fatty acid metal salt and / or an inorganic metal compound, or a carbonyl compound may be used in combination as another deodorant component. The fatty acid metal salt that can be used in the present invention is a saturated or unsaturated fatty acid metal salt having 1 to 30 carbon atoms, specifically, acetic acid, propionic acid, undecylenic acid, palmitic acid, lauric acid, myristic acid, stearin. Examples thereof include metal salts of saturated fatty acids such as acid and behenic acid, and metal salts of unsaturated carboxylic acids such as oleic acid, sorbic acid, linoleic acid, linolenic acid, ricinoleic acid and arachidonic acid. Examples of the metal component of the fatty acid metal salt include metal salts with zinc, copper, iron, molybdenum, cobalt, aluminum, titanium, manganese, nickel, silver, and the like. Of these fatty acid metal salts, zinc salts and aluminum salts are particularly preferable. The blending amount of the fatty acid metal salt is 1 to 120 parts by mass, preferably 2 to 50 parts by mass with respect to 100 parts by mass of the maleic anhydride copolymer.

  Examples of the inorganic metal compound that can be used in the present invention include oxides, hydroxides, and inorganic metal salts of metals such as calcium, magnesium, zinc, aluminum, copper, iron, and titanium. Specifically, examples of the oxide include calcium oxide, magnesium oxide, zinc oxide, copper oxide, iron oxide, ferric oxide, aluminum oxide, titanium oxide, and examples of the hydroxide include calcium hydroxide, magnesium hydroxide, Examples thereof include iron hydroxide, zinc hydroxide, and titanium hydroxide. Examples of inorganic metal salts include chlorides, sulfates, and nitrates of the above metals. Among these, ferrous sulfate, iron hydroxide, zinc hydroxide, titanium hydroxide, zinc oxide, titanium oxide, copper sulfate, copper nitrate, copper hydroxide, titanic acid and the like are preferable. The compounding quantity of this inorganic metal compound is 1-200 mass parts with respect to 100 mass parts of said copolymers, Preferably, it is 2-100 mass parts.

  Examples of the carbonyl compound that can be used in the present invention include ketocarboxylic acid and aldehyde acid. Examples of such carbonyl compounds include glycerin aldehyde, pyruvic acid, levulinic acid, aldehyde nonanoic acid, glyoxylic acid, aldehyde acid and the like. The compounding quantity of a carbonyl compound is 1-200 mass parts with respect to 100 mass parts of said maleic anhydride copolymers, Preferably, it is 5-80 mass parts.

  In the deodorant used in the present invention, the maleic anhydride copolymer, which is an essential component, has an excellent adsorptive power and deodorant mainly for substances causing body odor, such as amines and ammonia, which is a decomposition product thereof. Show the effect. On the other hand, fatty acid metal salts, inorganic metal compounds, and carbonyl compounds that may be used in combination with it absorb sulfur-based malodor-causing substances such as hydrogen sulfide and mercaptans. Therefore, a sufficient deodorizing effect can be obtained even when only the maleic anhydride copolymer is used for diapers or the like in which the cause of malodor is an amine compound. In addition, it is preferable to use a fatty acid metal salt, an inorganic metal compound, and a carbonyl compound in combination as the odor-causing substance having a large sulfur-based odor. Thus, the combined use of the maleic anhydride copolymer and a fatty acid metal salt can effectively remove the odors of ammonia, amine compounds and sulfur compounds.

The deodorizing property in the present invention is a detection tube method, specifically, a sample and a measurement target gas (odor) are enclosed in a Tedlar bag, and the gas concentration after 2 hours is measured using the detection tube. It is evaluated by the deodorization rate converted by. The control gas concentration is a gas concentration measured after 2 hours with only the gas to be measured enclosed in the Tedlar bag.
Deodorization rate (%) = {(control gas concentration−sample gas concentration) / control gas concentration}
× 100 (3)
As the deodorization rate in the polylactic acid fiber structure of the present invention, the deodorization rate with respect to ammonia is 80% or more. Moreover, as a preferable deodorizing rate, it is 90% or more, and as a more preferable deodorizing rate, it is 95% or more. Ammonia is a major odor component contained in sweat odor, aging odor, excretion odor, tobacco odor, and garbage odor. When the deodorization rate with respect to ammonia is less than 80%, it is not preferable because the effect is insufficient in the feeling of wearing after sweating when used as clothing and the deodorizing effect when used as daily necessities.

  In the polylactic acid fiber structure of the present invention, since the main resin composition is an aliphatic polyester mainly composed of a polylactic acid-based polymer, it is less intensive than a fiber made of polyolefin having a high barrier property. The odor effect is increased. This is because, in the case of polyolefin, the barrier property against a highly polar odorous component such as ammonia is high, so that the odorous component is less likely to penetrate into the fiber compared to aliphatic polyester. Even if it is melt-kneaded and the addition amount is increased, it is considered that there is little opportunity for reaction with the deodorant component distributed inside the fiber.

  In the polylactic acid fiber structure of the present invention, the main resin composition does not contain, for example, an aromatic polyester resin such as polyethylene terephthalate or a polyamide resin such as nylon 6 or nylon 66. At the time of melt kneading and spinning, an extra heat history such as melting at a higher temperature than that of a polylactic acid polymer is not added, which is accompanied by heat deterioration or gelation of the deodorant. A homogeneous woven fabric without coloration or the like can be obtained.

  As described above, in the present invention, the maleic anhydride copolymer having a predetermined structure is contained in the polylactic acid polymer in an amount of 0.1 to 7% by mass to effectively disperse the deodorant component in the resin. And the odorous component permeates moderately into the polylactic acid fiber, so that it effectively reacts with the deodorant component contained inside the fiber, thereby achieving a deodorization rate of 80% or more with respect to ammonia. Is done.

  Furthermore, in this invention, compared with the case where a deodorant component is made to adhere to the fiber surface by post-processing, deodorant content per unit mass of fiber can be increased, and the deodorant function has high durability. In addition, in the present invention, the deodorant component is contained in the inside of the fiber at a sufficient concentration in addition to being less detached from the fiber surface due to friction. Even if it is peeled off, the deodorant inside the fiber functions effectively, so the effect of high deodorant function has been developed even for repeated use after washing and friction during wear. Yes.

  In addition, in the present invention, since a fiber mainly composed of polylactic acid is used, the resulting fiber structure has antibacterial properties. Conventionally, lactic acid is known to have a bacteriostatic and fungicidal action and is used as a food preservative that improves the shelf life of food. The antibacterial property of the present invention is considered to be because the polylactic acid polymer constituting the polylactic acid fiber contains a small amount of lactic acid, lactide and other oligolactic acid.

  The single yarn fineness of the polylactic acid fiber in the present invention may be appropriately selected, but is preferably 0.3 dtex or more. If the single yarn fineness is less than 0.3 dtex, the operability during spinning tends to deteriorate, which is not preferable. Further, the upper limit of the single yarn fineness is not particularly limited. However, the larger the fiber surface area, the larger the contact area with the bacteria. Therefore, considering antibacterial properties, it is preferably 3 dtex or less.

  The form of the polylactic acid fiber of the present invention is not particularly limited. For example, as a fiber cross section, a flat cross section, a triangular cross, a multi-leaf, a hollow, a well-shaped cross section, etc. are adopted. May be. Further, any of staple, shortcut fiber, and filament may be used, and the filament may be monofilament or multifilament. The raw yarn may be processed yarn that has been subjected to false twisting, knit deniting, fluid ejection processing, or the like, and a twisted yarn having a twisting coefficient of about 1000 to 30000 using a double twister, an Italy-type twisting machine, a ring twisting machine, or the like. And may be mixed with other fibers within a range not impairing the effects of the present invention.

 Furthermore, the polylactic acid fiber may be in a composite form composed of two types of polylactic acid-based polymers. Examples of the composite form include a parallel composite form, a multilayer composite form, a core-sheath composite form, a split composite form, a split multileaf composite form, and the like.

  In addition, in the polylactic acid fiber of the present invention, other additives such as a heat-resistant agent, a light stabilizer, a fluorescent agent, an antioxidant, a matting agent, an antistatic agent, a pigment, a plasticizer, and a lubricant are added as necessary. Various additives such as a colorant, a colorant, a flame retardant, a reinforcing agent, an antistatic agent, a light resistance agent, and a heat stabilizer may be added within a range not impairing the effects of the present invention.

As the fiber structure of the present invention, the above-described polylactic acid fiber is mainly used to form yarns, cotton, woven fabrics, knitted fabrics, non-woven fabrics and the like. The fiber structure of the present invention may be composed of polylactic acid fibers alone, or synthetic fibers such as polyamide, aromatic polyester, polyacrylonitrile, polyurethane, or regenerated fibers such as rayon, lyocell, and acetate, and cotton. At least one or more kinds of fibers selected from natural fibers such as hemp, silk, wool, etc. and the polylactic acid fiber of the present invention may be blended or knitted in a range that does not impair the deodorant property.
Further, if necessary, dyeing may be performed within a range that does not impair the functions and effects of the present invention, and an antistatic agent, a softener, a water repellent, an antifouling agent, a deep colorant, a water absorbing agent, etc. It may be given.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these.
Moreover, the measurement and evaluation in an Example were performed with the following method.
(1) Deodorization A sample (10 cm × 10 cm) and ammonia gas were sealed in a 5 liter Tedlar bag to measure 100 ppm, and the gas concentration after 2 hours was measured using a detector tube. ) Was converted into a deodorization rate. The measurement was performed on three samples, and the average value was calculated. The control gas concentration is a gas concentration measured after 2 hours with only the gas to be measured enclosed in the Tedlar bag.
Deodorization rate (%) = {(control gas concentration−sample gas concentration) / control gas concentration} × 100 (3)
Incidentally, the deodorization rate of the polylactic acid fiber woven fabric (control cloth) to which no deodorant was added was 58.0% at the initial stage.
(2) Washing durability In order to evaluate the durability against deodorant washing, washing was carried out 10 times continuously by the JIS-L0217 103 method, and then the deodorizing property was evaluated.
(3) Spinnability Spinnability was evaluated in the following three stages.
○: Spinning breakage does not occur at all for 12 hours.
Δ: Spinning breakage occurs 1 to 3 times in 12 hours.
X: Spinning frequently occurs.

Example 1
A polylactic acid polymer having a number average molecular weight of 72,000 mainly composed of L-lactic acid (L-lactic acid unit: 98.8%, D-lactic acid unit: 1.2%) was added to 98.0% by mass, methyl Melting was performed at 210 ° C. while mixing 2.0% by mass of a vinyl ether / maleic anhydride copolymer (SE-900 manufactured by Okada Giken Co., Ltd.). The molten polymer was spun at a spinning temperature of 220 ° C., a nozzle number of 24 and a spinning speed of 3000 m / min to obtain 110 dtex / 36 filaments of polylactic acid fiber highly oriented undrawn yarn. The obtained highly oriented undrawn yarn had a strength of 2.48 cN / dtex and an elongation of 58.3%. Using this highly oriented unstretched yarn, false twisting was performed at a processing speed of 100 m / min, a heater temperature of 100 ° C., a false twist number of 3000 times / m, and a draw ratio of 1.20 times, and a polylactic acid fiber of 84 dtex / 36 filaments. A processed yarn was obtained. The obtained processed yarn had a strength of 2.42 cN / decitex and an elongation of 22.3%.

Next, two double twisted yarns (500 times / m) of 84 dtex / 36 filaments of polylactic acid fiber were used as warps, and four double twisted yarns (150 times / m of 84 dtex / 36 filaments of polylactic acid fiber processed yarn). ) Was used as the weft, and a plain woven fabric having a warp density of 95 / 2.54 cm and a weft density of 45 / 2.54 cm was woven. Subsequently, the plain woven fabric is scoured and relaxed in a nonionic active water solution at 80 ° C. for 20 minutes using a liquid dyeing machine, and then dried at 120 ° C. using a shrink surfer dryer. Further, a preset was performed at 130 ° C. for 1 minute. Furthermore, it dye | stained for 110 degreeC * 30 minutes by the following prescription 1 using the same dyeing machine. Then, it dried at 120 degreeC with the dryer, 130 degreeC * 1 minute final setting was performed, and the polylactic acid fiber structure (woven fabric) of this invention was obtained.
Formula 1
Disperse dye: Dianix Red AC-E 01 1% omf
(Dystar Japan Co., Ltd.)
Dispersant: Nikka Sun Salt SN-130 0.5 g / l
(Nikka Chemical Co., Ltd.)
Acetic acid (48%) 0.2cc / l

(Example 2)
In Example 1, the polylactic acid-based polymer was 99% by mass, and instead of the deodorizer composed of methyl vinyl ether / maleic anhydride copolymer, an isobutylene / maleic anhydride copolymer (isobutylene / maleic anhydride ( Example 1 except that 1.0% by mass of a deodorant comprising a molar ratio) = 50/50, molecular weight 100,000) and 10 parts by mass of zinc undecylenate were mixed with the deodorant. In the same manner as described above, the polylactic acid fiber structure (woven fabric) of Example 2 was obtained.

(Example 3)
In Example 2, except that the polylactic acid polymer was 96% by mass, the deodorant composed of isobutylene / maleic anhydride copolymer was changed to 4% by mass, and zinc undecylenate was not mixed. In the same manner as in Example 2, a polylactic acid fiber structure (woven fabric) of Example 2 was obtained.

(Comparative Example 1)
In Example 1, the polylactic acid fiber structure (woven fabric) of Comparative Example 1 was used in the same manner as in Example 1 except that the polylactic acid polymer was changed to 99.97% by mass and the deodorizer was changed to 0.03% by mass. )
(Comparative Example 2)
In Example 1, except that polylactic acid was changed to 92% by mass and the deodorant was changed to 8% by mass, melt mixing was performed in the same manner as in Example 1, but the deodorant was not uniformly mixed with polylactic acid. Therefore, the spinnability was poor and a polylactic acid fiber structure (woven fabric) could not be obtained.

  For Examples 1 to 3 and Comparative Examples 1 and 2, the spinnability, the initial stage, and the deodorization rate after 10 washes are shown in Table 1.

As is clear from Table 1, the polylactic acid fiber fiber structure (woven fabric) obtained by the method of the present invention has excellent deodorizing properties with no decolorization and a deodorizing rate of 80% or more, and It was excellent in washing durability. On the other hand, since the polylactic acid fiber structure (woven fabric) of Comparative Example 1 contains only 0.03% by mass of a deodorant comprising a maleic anhydride copolymer, the deodorization rate is almost the same as that of the control cloth. In addition, the deodorization rate after washing 10 times was further lowered, and the target deodorizing property was not obtained. In Comparative Example 2, the deodorizer composed of a maleic anhydride copolymer is 8% by mass, which is higher than the predetermined upper limit of 7% by mass. Therefore, the polylactic acid polymer cannot be uniformly melt-kneaded and spinnability is increased. However, since the polylactic acid fiber fabric was not obtained, the deodorization rate was not measured.

Claims (1)

Mainly composed of polylactic acid fiber containing 0.1 to 7% by mass of a deodorant comprising a maleic anhydride-based copolymer having the structural units of the following formulas (1) and (2) as an active ingredient, and is effective for eliminating ammonia. A polylactic acid fiber structure having an odor rate of 80% or more.

(In the formula, R ₁ is hydrogen or a methyl group, R ₂ is a methoxy group, a methyl group, or a vinyl group. However, when R ₂ is a methoxy group, R ₁ is not hydrogen)