JP2006225786A - Spun yarn in double layer structure and woven or knitted fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spun yarn in a double layer structure, capable of providing a woven or knitted fabric excellent in antimicrobial properties and safety to a human body; and to provide such the woven or knitted fabric. <P>SOLUTION: The spun yarn in the double layer structure having a core-sheath-type cross section is obtained by arranging a staple fiber group including a chitin fiber and/or a chitosan fiber of 3.0-30.0 mass% at the sheath part, and has a mass ratio of the core/the sheath of 0.25-1.50. The woven or knitted fabric is obtained by using the spun yarn in the double layer structure, and has ≥2.2 bacteriostatic activity value measured by the antimicrobial test method regulated by JIS L1092. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double-layer spun yarn and a woven or knitted fabric.

  Clothing that comes into direct contact with the human body, such as socks, underwear, or futons, will be exposed to sweat, and when given moderate temperature and humidity, microorganisms such as bacteria will grow and give off bad odors, discolor the fabric and become brittle. There are often problems such as

  In response to the current situation, as a woven or knitted fabric having antibacterial properties, a woven or knitted fabric using fibers in which an antibacterial agent is kneaded, a woven or knitted fabric coated with an antibacterial agent, and the like have been proposed.

  Antibacterial agents used for these include organic silicon quaternary ammonium salts and aromatic halogen compounds.

  However, there is a concern that the above-mentioned antibacterial agents may cause hypersensitivity such as rash depending on the individual constitution.

On the other hand, products using chitin fibers are known as antibacterial fiber products with high safety to the human body. For example, Patent Document 1 proposes an antibacterial fiber product using chitin mineral acid salt fibers.
JP-A-2-307915

  However, the above-mentioned antibacterial fiber product is specifically a medical non-woven fabric used for wound healing protection such as wounds and burns, and applied to the clothing field using spun yarns made of chitin fibers. The example has not been known yet.

  The present invention has been made in view of such a current situation, and provides a two-layer structure spun yarn capable of producing a woven or knitted fabric excellent in antibacterial properties and safety to the human body, and such a woven or knitted fabric. The task is to do.

  The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above problems.

  That is, the first invention is a two-layer structure spun yarn having a core-sheath cross section, and a short fiber group containing 3.0 to 30.0% by mass of chitin fiber and / or chitosan fiber is arranged in the sheath part. The gist of the spun yarn is a two-layer structure spun yarn having a core / sheath mass ratio of 0.25 to 1.50.

  The second invention is a woven or knitted fabric characterized in that the above-mentioned two-layer spun yarn is used, and the bacteriostatic activity value according to the antibacterial test method specified in JIS L1092 is 2.2 or more. It is what.

  The two-layer structure spun yarn of the present invention can be used for a woven or knitted fabric to produce a woven or knitted fabric excellent in antibacterial properties and safety to the human body. Further, the woven or knitted fabric of the present invention using the double-layer structure spun yarn of the present invention is a woven or knitted fabric excellent in antibacterial properties and safety to the human body, and also in hygroscopicity, texture and quality.

  Hereinafter, the present invention will be described in detail.

  The two-layer structure spun yarn of the present invention is a core-sheath type composite spun yarn having a structure in which a fiber group of a sheath part is wound around a fiber group of a core part.

  In the two-layer structure spun yarn of the present invention, the fiber group disposed in the core part may be either a long fiber group or a short fiber group. In addition, fiber types include natural fibers such as cotton, wool, hemp and bamboo, recycled fibers such as viscose rayon, copper ammonia rayon and solvent-spun cellulose fibers, synthetic fibers such as triacetate, nylon and polyester. Any of fibers may be used. Of course, biodegradable synthetic fibers such as polylactic acid, which have recently been applied, can also be used.

  On the other hand, the fiber group arranged in the sheath is a short fiber group. For this reason, a woven or knitted fabric excellent in hygroscopicity and texture can be obtained by using the double-layer structure spun yarn of the present invention. The short fiber group contains chitin fibers and / or chitosan fibers. For this reason, the woven or knitted fabric having high safety to the human body and excellent antibacterial properties can be obtained by using the double-layer structure spun yarn of the present invention. As content of chitin fiber and / or chitosan fiber, it is necessary to contain 3.0-30.0 mass% of chitin fiber and / or chitosan fiber with respect to the total mass of the short fiber group which comprises a sheath part.

  That is, among chitin fibers and chitosan fibers, (1) only chitin fibers are included in an amount of 3.0 to 30.0% by mass, or (2) only chitosan fibers are included in an amount of 3.0 to 30.0% by mass. Or (3) 3.0 to 30.0% by mass of chitin fibers and chitosan fibers are combined, or short fibers constituting the sheath in any one of (1) to (3) Included in the group. However, as will be described later, chitin fibers and chitosan fibers cannot always be strictly distinguished. In short, the total amount of chitin fibers and chitosan fibers is 3.0 to 30. It means that 0 mass% is contained.

  In the following description, chitin fibers and chitosan fibers may be collectively referred to as “chitin fibers”.

  If the content of the chitin fiber is less than 3.0% by mass, the woven or knitted fabric cannot exhibit the desired antibacterial properties. On the other hand, when it exceeds 30.0 mass%, it becomes a spun yarn with large spots, and the quality of the woven or knitted fabric is impaired.

  The fibers other than the chitin fibers contained in this short fiber group may be any of natural fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers as in the case of the fibers used for the core described above. .

  In this short fiber group, it is possible to make the content of chitin fibers within a predetermined range by mixing a predetermined amount of chitin fibers in the blended cotton process or the kneading process.

  In the two-layer structure spun yarn of the present invention, the core / sheath mass ratio needs to be 0.25 to 1.50. When the mass ratio of the core / sheath is less than 0.25, the fiber group of the sheath part is hardly wound around the fiber group of the core part. On the other hand, if it exceeds 1.50, the fiber group of the sheath part cannot cover the fiber group of the core part.

  Here, chitin and chitosan used in the present invention will be described. The chitin and chitosan used to constitute the chitin fiber in the present invention include those obtained by removing ash and protein by treating the exoskeleton of crustaceans and insects with hydrochloric acid and caustic soda, and derivatives thereof. Can be used.

Chitin is typically a polysaccharide in which many N-acetyl-D-glucosamine residues are β- (1,4) -linked, and its deacetylated product is called chitosan, but chitin partially loses the acetyl group. It is normal. On the other hand, chitosan is typically a β- (1,4) -polymer of D-glucosamine residues, but like chitin, it usually has some acetyl group and is called chitosan. Is common sense (for example, “The Last Biomass Chitin, Chitosan”, 1988, published by Gihodo). For this reason, the distinction between chitin and chitosan is not strict, and in the present invention, it is not necessary to strictly distinguish them. For example, as a guide, what is dissolved in an acid due to its high degree of deacetylation may be chitosan. Therefore, the chitin and chitosan used in the present invention include chitin which may partially lose the acetyl group, chitosan which may contain some acetyl groups, and further the —OH group of those glucosamine residues. And derivatives in which the —CH ₂ OH group is modified to esterification, etherification, carboxymethylation, O-ethylation or the like are included. In describing the present invention, chitin fibers and chitosan fibers are sometimes collectively referred to as “chitin fibers” because of such circumstances. For the same reason, in the following explanation, chitin and Chitosan is sometimes collectively referred to as “chitins”.

  As the degree of deacetylation, a wide range up to complete deacetylation can be adopted, but it is preferably 30 to 100%. Chitin can be deacetylated by a well-known method of treating chitin with an alkali. At this time, the degree of deacetylation can be easily adjusted by appropriately changing the alkali concentration used, the treatment temperature, the treatment time, and the like.

  The degree of deacetylation here refers to a value measured by the following method. That is, about 2 g of a sample is put into 200 ml of 2N-hydrochloric acid aqueous solution and stirred at room temperature for 30 minutes. Next, after filtering with a glass filter to remove the aqueous hydrochloric acid solution, the solution is put into 200 ml of methanol and stirred for 30 minutes. This is further filtered through a glass filter, put into 200 ml of fresh methanol, and stirred for 30 minutes. After repeating this methanol washing operation four times, about 0.2 g of air-dried and vacuum-dried material is precisely weighed, taken into a 100 ml Erlenmeyer flask, added with 40 ml of ion-exchanged water, and stirred for 30 minutes. Next, this solution is subjected to neutralization titration with a 0.1N sodium hydroxide aqueous solution using phenolphthalein as an indicator. Deacetylation degree (A) is calculated | required by following Formula.

  Where a is the mass (g) of the sample, f is the titer of the 0.1N-caustic soda aqueous solution, and b is the titration (ml) of the 0.1N-caustic soda aqueous solution.

  The chitin fiber used in the present invention is not particularly limited as long as it is a fibrous fiber formed of chitins. If chitins obtained from nature are fibrous, they can be used as they are. Alternatively, a solution obtained by dissolving chitins in a solvent and then coagulating with a coagulating liquid to form a fiber may be used.

  The solvent can be appropriately selected and used depending on the kind of chitins. For example, for chitin as a natural product and chitin with a relatively low degree of deacetylation, a mixture of halogenated hydrocarbon and trichloroacetic acid, a mixture of N-methylpyrrolidone or N, N-dimethylacetamide and lithium chloride Is preferably used, and an acid solution such as acetic acid is preferably used for chitosan.

  As a method of dissolving chitins in a solvent and forming fibers, a normal wet spinning method or wet molding method can be employed. For example, chitins are dissolved in the above solvent to prepare a dope, filtered with a filter such as a stainless steel net to remove insoluble parts and foreign matter, and then metered and transported with a gear pump, etc. It is solidified by being extruded into a coagulating liquid such as ketones or alkali liquid. A fiber can be obtained by pulling the coagulum at a constant speed with a rotating roller or the like.

  The single yarn fineness of the chitin fiber used in the present invention is not particularly limited, but is preferably 0.27 to 9.0 dtex, more preferably 0.45 to 4.5 dtex, and particularly preferably 0.6 to 2.7 dtex. The fiber length of the chitin fiber is preferably 10.0 to 80.0 mm, more preferably 15.0 to 70.0 mm, and particularly preferably 20.0 to 60.0 mm.

  As described above, the two-layer structure spun yarn of the present invention contains chitin fibers, but the content thereof is smaller than the content of other fibers. For this reason, the double-layer structure spun yarn of the present invention can reflect the characteristics of other fibers. Therefore, when producing the double-layer structure spun yarn of the present invention, other fibers may be selected in consideration of the intended use of the woven or knitted fabric finally obtained and the performance required for the woven or knitted fabric. .

  The two-layer structure spun yarn of the present invention is composed of a chitin fiber composed of chitins having antibacterial properties, unlike the case where chitin particles are adhered to the fiber surface. Therefore, chitins are difficult to drop off, and antibacterial properties are maintained.

  Next, a woven or knitted fabric using the double-layer structure spun yarn of the present invention (hereinafter sometimes referred to as “the woven or knitted fabric of the present invention”) will be described.

  The woven or knitted fabric of the present invention is formed by using the above-described two-layer structure spun yarn of the present invention, and can maintain antibacterial properties as long as the chitin fiber does not fall off as described above. Therefore, it exhibits antibacterial properties with excellent washing durability.

Here, as the antibacterial property of the woven or knitted fabric of the present invention, the bacteriostatic activity value according to the antibacterial test method specified in JIS L1092 needs to be 2.2 or more, and preferably 3.0 or more. The bacteriostatic activity value refers to inoculating a standard sample and test sample with a certain number of bacteria, and B (cells / ml) of the standard sample after incubation for a certain period of time. It is represented by logB-logC where the viable cell count of the sample is C (cells / ml). Staphylococcus aureus ATCC 6538P (Staphylococcus aureus) is used as the strain used. As a test method, 0.4 g of a sterilized sample placed in a vial was inoculated with 0.2 ml of a bacterial solution adjusted to a viable count of (1 ± 0.3) × 10 ⁵ cells / ml as uniformly as possible. Incubate at 18 ° C. for 18 hours. Next, 20 ml of physiological saline supplemented with 0.2% nonionic surfactant (Twin 80) is added and stirred to wash out the bacteria. Then, 1 ml of the washing solution is collected with a pipette, a dilution series is prepared by a 10-fold dilution method, mixed with a nutrient agar medium, and cultured at 37 ° C. for 24 hours or more. Count the number of colonies in the dilution series in which 30 to 300 colonies appeared, and calculate the number of viable bacteria.

  For the calculation of the bacteriostatic activity value, the above-mentioned test is performed for each of the standard sample (attached fabric for dyeing fastness test specified in JIS L0803) and the test sample, and the bacteriostatic activity value is obtained from the following formula.

  However, B is the number of viable bacteria collected after 18 hours of culture of the standard sample, and C is the number of viable bacteria collected after 18 hours of incubation of the test sample.

  If the bacteriostatic activity value is less than 2.2, the growth of bacteria cannot be suppressed, and the performance as an antibacterial woven or knitted fabric is not sufficient.

Next, the present invention will be specifically described with reference to examples. Evaluation of the two-layer structure spun yarn and the woven or knitted fabric in Examples and Comparative Examples was performed according to the following method. The antibacterial evaluation, that is, the bacteriostatic activity value, was determined according to the method described above.
(1) Yarn spots The variation ratio (CV%) of the average spot deviation was measured according to the JIS L109599.20.1A method using a Yarn Spot Tester (manufactured by Keiki Kogyo Co., Ltd., “KET80B”).
(2) Washing durability The bacteriostatic activity value was measured according to the above-mentioned antibacterial test method for the sample after 50 washings specified in JIS L0217 103 method.
(3) Quality of knitted and knitted fabrics 10 panelists have sensory evaluation in three stages: ○: excellent quality, △: normal quality, x: poor quality, and the highest number of evaluators The quality of the sample was evaluated.

Example 1
As chitosan fibers used in the examples, a chitosan fiber lump composed of short fibers having a single yarn fineness of 2.2 dtex and a fiber length of 38 mm was prepared by wet spinning chitosan obtained from crab shell as a raw material. The degree of deacetylation of this chitosan was 78%. Further, a comb river having a thickness of 3.57 g / m (hereinafter referred to as “cotton comm sliver”) obtained by a normal spinning method using a cotton fiber having a single yarn fineness of 1.42 dtex and a fiber length of 32 mm. Prepared separately.

  In the blended cotton process, the above chitosan fiber lump and cotton comb sliver were used and mixed at a mass ratio of chitosan fiber lump / cotton comb sliver = 50/50. m blended card sliver was obtained. Next, in the drawing step, the blended card sliver and the cotton comb sliver are used and mixed at a predetermined ratio so that the content of chitosan fiber is 6.3% by mass. A blended sliver sliver having a thickness of 3.29 g / m and containing 3% by mass was obtained. Next, in the roving process, a strip sliver (hereinafter referred to as “kneading”) having a thickness of 3.57 g / m obtained by a normal spinning method using cotton fibers having a single yarn fineness of 1.42 dtex and a fiber length of 32 mm. Is arranged in the core portion, the mixed spun sliver obtained above is arranged in the sheath portion, twisted with a twist coefficient of 0.95, and the mass ratio of the core / sheath is 1. A roving yarn having a thickness of 0.595 g / m, which was 08, was obtained. Then, in the spinning process, the roving obtained above is given a draft of 42.4 times, subjected to twisting with a twisting factor of 3.5, and the double-layer structure of the present invention of 40th (English cotton count) A spun yarn was obtained.

  In the sheath part of this two-layer structure spun yarn, 6.3 mass% chitosan fiber was contained with respect to the total mass of the short fiber group. The mass ratio of the core / sheath was 1.08.

  Further, using this double-layered spun yarn, a knitting machine of a tengu knitted fabric is knitted by a circular knitting machine of 28 gauge and a hook diameter of 76 cm, and subjected to scouring and bleaching with hydrogen peroxide to obtain the woven or knitted fabric of the present invention It was.

(Comparative Example 1)
In the drawing step, using the blended card sliver used in Example 1 and the cotton comb sliver used in Example 1, mixing is performed at a predetermined ratio so that the content of chitosan fiber is 32.0% by mass. As a result, a blended and kneaded strip sliver having a thickness of 3.29 g / m and containing 32.0% by mass of chitosan fiber was obtained. The mixed spinning kneaded sliver is arranged in the sheath, and the knit cotton sliver used in Example 1 is arranged in the core, and in the roving process, twisting with a twist coefficient of 1.00 is performed, and the mass of the core / sheath A roving yarn having a ratio of 1.08 and a thickness of 0.595 g / m was obtained. Then, spinning was performed under the same conditions as in Example 1 to obtain a double-layered spun yarn of 40 count (English cotton count).

  The short fiber group disposed in the sheath portion of the two-layer structure spun yarn contained 32.0% by mass of chitosan fiber with respect to the total mass of the short fiber group. Moreover, the mass ratio of the core / sheath in the double-layer structure spun yarn was 1.08.

  Further, knitting, scouring, and bleaching were carried out in the same manner as in Example 1 using this double-layer structure spun yarn to obtain a woven or knitted fabric.

(Comparative Example 2)
In the drawing step, the blended card sliver used in Example 1 and the cotton comb sliver used in Example 1 were mixed at a predetermined ratio so that the chitosan fiber content was 2.5 mass%. As a result, a blended and kneaded strip sliver having a thickness of 3.29 g / m and containing 2.5% by mass of chitosan fiber was obtained. This mixed spinning kneaded sliver is arranged in the sheath, the knit cotton sliver used in Example 1 is arranged in the core, and after the rough spinning under the same conditions as in Example 1, under the same conditions as in Example 1. Spinning was performed to obtain a double-layer spun yarn of 40 count (English cotton count).

  The short fiber group disposed in the sheath portion of the two-layer structure spun yarn contained 2.5% by mass of chitosan fiber with respect to the total mass of the short fiber group. Moreover, the mass ratio of the core / sheath in the double-layer structure spun yarn was 1.08.

  Further, knitting, scouring, and bleaching were carried out in the same manner as in Example 1 using this double-layer structure spun yarn to obtain a woven or knitted fabric.

  Table 1 below shows the variation rate (CV%) of the average unevenness of the double-layered spun yarn in the above Examples and Comparative Examples, the bacteriostatic activity value before and after washing of the woven or knitted fabric, and the quality of the woven or knitted fabric.

  As can be seen from the results in Table 1, the double-layered spun yarn of the present invention had little yarn unevenness. In addition, the woven or knitted fabric of the present invention using this two-layer structure spun yarn has antibacterial properties with excellent washing durability and excellent quality.

  On the other hand, in Comparative Example 1, since the chitosan fiber was excessively contained in the short fiber group constituting the sheath portion of the two-layer structure spun yarn, the spots of the two-layer structure spun yarn became large. Further, the woven or knitted fabric using the double-layer structure spun yarn was inferior in quality.

In Comparative Example 2, the content of chitosan fiber in the short fiber group constituting the sheath portion of the double-layer structure spun yarn was too small, so that sufficient antibacterial properties could not be expressed.

Claims (2)

  A core-sheath type two-layer structure spun yarn having a cross section of core-sheath fibers containing 3.0 to 30.0% by mass of chitin fiber and / or chitosan fiber is arranged in the sheath part, and the mass ratio of the core / sheath is A spun yarn having a two-layer structure characterized by being 0.25 to 1.50. A woven or knitted fabric comprising the spun yarn according to claim 1 and having a bacteriostatic activity value of 2.2 or more according to an antibacterial test method defined in JIS L1092.