JP2004232106A - Carbon-containing fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon-containing fiber which comprises a biodegradable polymer and has a blood flow-promoting effect. <P>SOLUTION: This carbon-containing fiber is characterized by dispersing carbon powder satisfying the following values in a fiber composed of a biodegradable polymer. A porosity ε: ≥0.56. A tensile breaking strength δt: ≥3,600 Pa. A particle size: ≤5 μm. A content: 3 to 7 wt. %. The biodegradable polymer is preferably polylactate having a relative viscosity [ηrel] of 2.5 to 3.8 and an L-isomer rate of ≥95%. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４１】
炭パウダー含有率とは、血流量測定に使用した編布の炭パウダー量を算出し、それを百分率で表したものである。糸の強度測定は、ＪＩＳ Ｌ−１０１３に準じ、（株）島津製作所製のＡＧＳ−１ＫＮＧ オートグラフ引張試験機を用い、試料長２０ｃｍ、定速引張速度２０ｃｍ／分の条件で測定し、試料が伸長破断したときの強力の値から繊維強度を算出した。延伸操業性は、糸巻量５１０ｇにて糸切れ無く巻き上がった本数を百分率で表したものである。表１に記す通り、ポリ乳酸単独糸に比べ、備長炭を混合している繊維は、血流促進効果は非常に優れ、又、備長炭の含有量に比例して血流促進効果は増大した。糸の強度は、炭パウダーを混合すれば低下するが後加工通過性に問題なく、紡糸延伸操業性も良好である。
【００４２】
比較例２
備長炭をホソカワミクロン社製 アルピネ カウンタージェットミルにより実施例１と異なる条件にて微粉砕した後、アグロボットにより、初期設定荷重５０ｋｇ、最大圧縮応力１．０ＭＰａの条件で測定した結果、炭パウダーの空隙率が０．５０、引張破断強度が３７００Ｐａであった。その炭パウダーを使用する以外、実施例１記載の工程で実施した。結果を表２に記す。
【００４３】
【表２】

【００４４】
比較例２は炭パウダーの均一分散性が悪いため、血流促進効果もあまり良くない。しかも、紡糸中の濾過圧の著しい上昇が見られ、紡糸、延伸性が悪化し得られた糸の強度も低いものであった。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to carbon-containing synthetic fibers that are biodegradable.
[0002]
[Prior art]
Charcoal, especially Bincho charcoal made from Ubamegashi as a raw material and carbonized at a high temperature, has been used as a fuel since ancient times. However, in recent years, various uses other than fuel have been proposed.
[0003]
For example, Japanese Patent Application Laid-Open No. 2001-348723 discloses a synthetic fiber in which fine carbon powder is blended in a fiber to impart a hygroscopicity and an antistatic effect, a cotton-like material using the same, and a sewing including the same. The body is disclosed.
[0004]
However, the publication is intended to impart a hygroscopic property and an antistatic effect, and is not a biodegradable synthetic fiber aimed at by us, which aims at a blood flow promoting effect.
[0005]
JP-A-2002-249923 describes a synthetic fiber having functions of deodorization, far-infrared radiation, and negative ion effect by adding charcoal fine particles to a biodegradable synthetic fiber.
[0006]
Again, the method of incorporating finely ground charcoal microparticles into biodegradable synthetic fibers is similar to the present invention, but does not mention the blood flow promoting effect that we are aiming for.
[0007]
[Patent Document 1]
JP 2001-348723 A [Patent Document 2]
JP 2002-249923 A
[Problems to be solved by the invention]
An object of the present invention is to provide a biodegradable synthetic fiber that can obtain a blood flow promoting effect that has never been achieved by kneading finely ground charcoal powder into fiber and that can be stably produced.
[0009]
[Means to solve the problem]
The first aspect of the present invention is a charcoal-containing fiber characterized in that charcoal powder satisfying the following values is dispersed in a biodegradable polymer.
Porosity ε ≧ 0.56
Tensile breaking strength δt (Pa) ≦ 3600
[0010]
A second aspect of the present invention is the fiber as described above, wherein the biodegradable polymer is a polylactic acid fiber.
[0011]
A third aspect of the present invention is the fiber as described above, wherein the particle size of the charcoal powder is 5 µm or less and the content is 3 to 7% by weight.
[0012]
A fourth aspect of the present invention is the fiber as described above, wherein the relative viscosity [ηrel] of the polylactic acid used is 2.5 to 3.8, and the ratio of L-form is 95% or more.
[0013]
A fifth aspect of the present invention is the fiber as described above, wherein the fiber tensile strength is 1.3 to 2.2 cN / dtex.
[0014]
A sixth aspect of the present invention is the fiber as described above, wherein the charcoal powder is Bincho charcoal.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The charcoal powder that can be used in the present invention must have the following characteristic values.
Porosity ε ≧ 0.56
Tensile breaking strength δt (Pa) ≦ 3600
[0016]
Here, the porosity is a porosity when the particles are arranged assuming that the powder particles are spherical. The tensile strength at break is the maximum strength when the powder layer formed by compressing the coal powder is pulled and the powder layer is split. When the porosity is smaller than 0.56, the cohesiveness of the powder becomes strong, the uniform dispersibility is lacking, the polymer filtration pressure rises greatly, the spinning and drawing operability become extremely poor, and the strength of the obtained yarn is also low. Become.
On the other hand, if the tensile strength at break is greater than 3600, the porosity is smaller than the above range, so that the cohesiveness of the powder becomes stronger, the uniform dispersibility is lacking, the spinning and drawing operability deteriorates, and the strength of the yarn decreases. Mimic
[0017]
The charcoal powder that can be used in the present invention is made from Bincho charcoal by Alpine counter jet mill manufactured by Hosokawa Micron Corporation. What is important as the production conditions is the air pressure and the amount of air for blowing the raw material bincho charcoal. Charcoal powder is produced under the conditions of an air pressure of 0.59 MPa and an air amount of about 0.72 m ³ / min. Further, the obtained charcoal powder is classified into 5 μm or less by a classifier, and the obtained charcoal powder can be used in the present invention.
[0018]
The particle size of the coal powder of the present invention is preferably 5 μm or less, more preferably 2 μm or less. By controlling the particle diameter to 5 μm or less, the spinning and drawing operability is improved, and the physical properties of the obtained fiber are also excellent. The particle size is measured by a laser particle size analyzer.
[0019]
The charcoal powder is preferably blended in the polymer in an amount of 3 to 7% by weight, more preferably 4 to 6% by weight. When the blending amount of the charcoal powder is 3 to 7% by weight, the effect of promoting blood flow is sufficient, the spinning operability is good, and the strength of the yarn is sufficient.
[0020]
The charcoal powder used in the present invention is preferably Bincho charcoal. Bincho charcoal is recognized for its odor-absorbing and deodorizing effect, humidity control effect, and heat-retaining heat storage effect due to its fine and complicated intricate porous structure.
[0021]
The biodegradable polymer used in the present invention is preferably a biodegradable aliphatic polyester. For example, poly (α-hydroxy acids) such as polylactic acid and polyglycolic acid, or copolymers containing these as main repeating units. Particularly preferred biodegradable aliphatic polyesters include polylactic acid or copolymers containing lactic acid units as a main component.
[0022]
Preferably, by using a polylactic acid polymer having a relative viscosity [ηrel] in the range of 2.5 to 3.8, a sufficient initial strength is obtained, the weaving property is good, and the strength due to hydrolysis during washing is good. It is preferable because the decrease is small. More preferably, the relative viscosity [ηrel] is from 2.7 to 3.0.
[0023]
The polylactic acid used in the present invention is made from L-lactic acid, D-lactic acid or L-lactide, D-lactide or mesolactide which is a dimer of lactic acid as a raw material. This increases the crystallinity of the yarn and increases the strength.
It is preferable to use L-lactic acid as a main repeating unit because the production cost is low. The ratio of the L-form of polylactic acid is preferably 95% or more. More preferably, it is 98% or more.
[0024]
If the amount of residual monomer is large, hydrolysis of the polylactic acid fiber occurs due to moisture in the air, and the strength of the yarn is rapidly reduced. Therefore, it is necessary to reduce the residual monomer in the polylactic acid fiber. When the residual monomer content in the fiber is 0.8 wt% or less, hydrolysis in the air is preferably suppressed. More preferably, it is at most 0.5 wt%, particularly preferably at most 0.2 wt%. The monomer referred to in the present invention is a component having a molecular weight of 1000 or less calculated by GPC analysis described later.
[0025]
The single yarn fineness of the fiber of the present invention is preferably 2 dtex or more. When the single yarn fineness is 2 dtex or more, a predetermined amount of charcoal powder can be blended. The fiber form is preferably a raw or processed yarn or spunbond consisting of filaments, a nonwoven fabric, spun yarn or wadding made of short fibers. Although it is possible to use a multifilament yarn and a spun yarn at the same time, it is preferable to use a multifilament yarn when special attention is paid to dust generation.
[0026]
In general, when inorganic particles are mixed with a thermoplastic resin, the tensile strength decreases, and furthermore, charcoal powder is porous and has a moisture absorbing effect, and when kneaded with polyester, the tensile strength of the obtained fiber is significantly reduced. The fiber of the present invention has a tensile strength of 1.3 to 2.2 cN / dtex or less by using a carbon powder having a porosity ε ≧ 0.56 and a tensile breaking strength δt (Pa) ≦ 3600. There is no problem in production, post-processing, and product use.
[0027]
The charcoal powder is discharged from the spinneret together with the polylactic acid fiber during, for example, melt spinning. In producing the fiber of the present invention, first, a master chip containing 10 to 25% by weight of finely pulverized charcoal powder in a polylactic acid resin is manufactured, and this is mixed with a polylactic acid resin pellet. The carbon powder in the polylactic acid fiber as a whole is preferably 3 to 7% by weight, more preferably having a sufficient blood flow promoting effect, good spinning and twisting operability, and sufficient fiber strength. It should be 4 to 6% by weight.
[0028]
Melt spinning can be spun by a conventional method or a direct drawing method without special consideration. Further, various cross-sections such as a round cross section, a triangular cross section, a square cross section, a polygonal cross section, a flat cross section, and a hollow cross section can be used as the cross section of the yarn.
[0029]
【The invention's effect】
Since the biodegradable carbon-containing synthetic fiber of the present invention contains charcoal powder, a blood flow promoting effect can be obtained. The object of the present invention can be achieved by using the carbon-containing fiber alone or in combination with other fibers.
[0030]
In addition, although not the main object of the present invention, various excellent functions inherent to charcoal, such as hygroscopicity, adsorption of chemical substances, warming by far-infrared radiation, generation of negative ions, etc. can be simultaneously exhibited. Things.
[0031]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to those listed here. First, the analysis methods for the properties of charcoal powder and polymer are introduced.
[0032]
The porosity and tensile strength at break of the charcoal powder were measured with an Agrobot manufactured by Hosokawa Micron Corporation.
[0033]
(Relative viscosity ηrel)
A sample was dissolved in a mixed solvent of phenol / tetrachloroethane = 60/40 (volume ratio) to a concentration of 1 g / dL, and the relative viscosity was measured at 20 ° C. using an Ubbelohde viscosity tube.
[0034]
(L-form ratio)
The polylactic acid resin was hydrolyzed, and the ratio of L-form was determined using high-performance liquid chromatography (HPLC: LC10AD type manufactured by Shimadzu Corporation) using 1.0 N methanolic sodium hydroxide solution as a solvent.
[0035]
Examples 1-3
Bincho charcoal was finely pulverized to a particle size of 5 μm or less using an Alpine counter jet mill manufactured by Hosokawa Micron Co., Ltd., and measured with an ag robot under the conditions of an initial set load of 50 kg and a maximum compressive stress of 1.0 MPa. Rate was 0.589 and tensile strength at break was 3415 Pa.
[0036]
An L-body ratio of 98.8% and a relative viscosity of 2.83 are blended with the finely pulverized Bincho charcoal described in the preceding paragraph, so that the content of Bincho charcoal is 10% by weight, A master chip (i) was produced by melting and mixing with a twin screw kneader equipped with a vent manufactured by Nippon Steel Corporation. Thereafter, a polylactic acid tree having an L-body ratio of 98.8% and a relative viscosity of 2.83 was prepared so that the content of Bincho charcoal was 4.0, 5.0, and 7.0% by weight. The mixed chips were mixed chips (ii).
[0037]
The mixed chip (ii) is dried to a moisture content of 100 ppm or less, spun at a spinning temperature of 230 ° C. and a take-up speed of 1200 m / min, and then the draw ratio and the amount of polymer discharged are adjusted so that the elongation becomes 32%. The film was drawn at a roller speed of 85 ° C. and a plate heater temperature of 150 ° C. at a drawing speed of 700 m / min to obtain a yarn of 84 dtex / 24 filaments.
[0038]
The drawn yarn obtained in the above was circularly knitted, a circular knitted cloth having a length of 70 cm was attached to both hands and feet, and a laser blood flowmeter OMEGA FLOW-C1HP manufactured by Omega Wave Co., Ltd. was used. The rate of increase in blood flow was determined under the conditions of 0.2 ° C. and 55 ± 3% humidity.
[0039]
Comparative Example 1
The kneading chips (ii) were not mixed with Bincho charcoal, and the polylactic acid resin having an L-body ratio of 98.8% and a relative viscosity of 2.83 was changed. The spinning temperature was changed to 230 ° C, and the elongation of the yarn was changed. Was changed by changing the stretching ratio and the amount of discharged polymer so as to be 32%. The blood flow rate was measured under the same conditions as in Example 1, and the results of the strength of the yarn and the drawability were shown in Table 1.
[0040]
[Table 1]

[0041]
The charcoal powder content is obtained by calculating the amount of charcoal powder of the knitted fabric used for blood flow measurement and expressing it in percentage. The strength of the yarn was measured according to JIS L-1013 using an AGS-1KNG autograph tensile tester manufactured by Shimadzu Corporation under the conditions of a sample length of 20 cm and a constant-speed tensile speed of 20 cm / min. Fiber strength was calculated from the value of the strength at the time of elongation breaking. The drawing operability is the percentage of the number of yarns wound without breaking the yarn at a winding amount of 510 g. As shown in Table 1, the fiber mixed with Bincho charcoal has a very excellent blood flow promoting effect, and the blood flow promoting effect is increased in proportion to the content of Bincho charcoal, as compared with the polylactic acid alone yarn. . The yarn strength is reduced by mixing the charcoal powder, but there is no problem in the post-processability and the spinning and drawing operability is good.
[0042]
Comparative Example 2
Bincho charcoal was finely pulverized by a Hosokawa Micron Alpine counter jet mill under conditions different from those of Example 1, and measured by an Agrobot under the conditions of an initial set load of 50 kg and a maximum compressive stress of 1.0 MPa. Rate was 0.50 and tensile strength at break was 3700 Pa. The procedure was as described in Example 1, except that the charcoal powder was used. The results are shown in Table 2.
[0043]
[Table 2]

[0044]
In Comparative Example 2, the effect of promoting the blood flow is not so good because the uniform dispersibility of the charcoal powder is poor. In addition, a remarkable increase in the filtration pressure during spinning was observed, and the spinning and stretching properties were deteriorated, and the strength of the obtained yarn was low.

Claims (6)

A charcoal-containing fiber, wherein charcoal powder satisfying the following values is dispersed in a fiber made of a biodegradable polymer.
Porosity ε ≧ 0.56
Tensile breaking strength δt (Pa) ≦ 3600 The fiber according to claim 1, wherein the biodegradable polymer is polylactic acid. The fiber according to any one of claims 1 to 2, wherein the particle size of the charcoal powder is 5 µm or less and the content is 3 to 7% by weight. The fiber according to any one of claims 2 to 3, wherein the polylactic acid used has a relative viscosity [ηrel] of 2.5 to 3.8 and an L-form ratio of 95% or more. The fiber according to any one of claims 1 to 4, wherein the fiber has a tensile strength of 1.3 to 2.2 cN / dtex. The fiber according to any one of claims 1 to 5, wherein the charcoal powder is Bincho charcoal.