JP2017066558A - Core-sheath type conjugate fiber, fiber structure and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core-sheath type conjugate fiber that has antipilling property, hardly causes sticking between fibers and has high dyeability and high productivity, to provide a fiber structure using the conjugate fiber and to provide a method for producing the fiber structure.SOLUTION: The core-sheath type conjugate fiber (1) includes a core component (2) and a sheath component (3). The core component (2) is a copolyester including at least an aliphatic dicarboxylic acid component as a copolymer component and having a melting point of not less than 180°C to not more than 250°C. The sheath component (3) is a polyolefin and the ratio of the sheath component is not less than 25 mass% to not more than 65 mass% when the core-sheath type conjugate fiber is 100 mass%. The fiber structure is a fiber structure composed of the core-sheath type conjugate fiber (1) or a fiber structure including the core-sheath type conjugate fiber (A) and other fiber (B) in which the mixing ratio of the core-sheath type conjugate fiber (A) and the other fiber (B) is in the range of 10≤A≤100 and 0≤B≤90 by mass%. The method for producing the fiber structure comprises dyeing the fiber structure at a temperature in the range of 110 to 130°C using a disperse dye.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a core-sheath type composite fiber whose core component is polyester and whose sheath component is polypropylene, a fiber structure using the same, and a method for producing the same.

  Conventionally, a composite fiber having polyester as a core component and polypropylene as a sheath component is known. Patent Document 1 proposes to dispose a resin in which a polyester is mixed in the core and polypropylene and polyester are mixed in the sheath. Patent Document 2 proposes that polyester is disposed in the core portion and polypropylene is disposed in the sheath portion so that the volume ratio of the core portion to the sheath portion is 1/4 to 1/10. The present applicants have proposed a core-sheath type composite fiber in which polypropylene is arranged in the core part and a disperse dye-dyeable modified polyester is arranged in the sheath part in Patent Document 3.

JP 2008-261070 A WO2011 / 155524 JP 2012-193484 A

  However, the conventional core-sheath type composite fiber has a problem that the fiber breaks due to friction generated during spinning or use, and so-called fibrillation easily occurs. When fibrillation occurs, the polyester component on the dyed fiber surface breaks, and the undyed polypropylene component inside the fiber is exposed to the outside, so when dyed in dark colors such as black, the fiber product gradually whitens. In addition to the deterioration of the appearance, there is a problem that so-called pilling is likely to occur, which is caused by entanglement of fine fibers generated by fibrillation. This problem also applies to Patent Document 1 in which a resin in which polypropylene and polyester are mixed is disposed in the sheath. This is because both polymers are incompatible. In addition, Patent Document 2 in which the sheath portion is thick has a problem that it is difficult to dye deeply because polypropylene is essentially not dyed. Furthermore, Patent Document 3 in which polyester is arranged in the sheath has a problem that fiber-to-fiber sticking is likely to occur depending on manufacturing conditions, in addition to the problem that pilling is likely to occur.

  In order to solve the above-mentioned conventional problems, the present invention has a core-sheath type composite fiber that has anti-pilling properties, is less likely to cause sticking between fibers, and has high dyeability, high strength, and high productivity, and a fiber structure using the same And a method for manufacturing the same.

  The core-sheath type composite fiber of the present invention is a core-sheath type composite fiber containing a core component and a sheath component, and the core component contains at least an aliphatic dicarboxylic acid component as a copolymer component, and a melting point is 180 ° C. or higher. It is a copolymerized polyester of 250 ° C. or lower, the sheath component is polyolefin, and the sheath component is 25% by mass or more and 65% by mass or less when the core-sheath type composite fiber is 100% by mass. To do.

  The fiber structure of the present invention is a fiber structure comprising the above-described core-sheath type composite fiber (A) or the above-described core-sheath type composite fiber (A) and other fibers (B), The mixing ratio of the core-sheath type composite fiber (A) and the other fibers (B) is in a range of 10 ≦ A ≦ 100 and 0 ≦ B ≦ 90 in mass%.

  The method for producing a fiber structure according to the present invention is characterized in that the fiber structure is dyed using a disperse dye in a temperature range of 110 to 130 ° C.

  In the present invention, the core component is a copolymer polyester containing at least an aliphatic dicarboxylic acid component as a copolymer component, a melting point of 180 ° C. or higher and 250 ° C. or lower, a sheath component is a polyolefin, Is 100 mass%, the sheath component is 25 mass% or more and 65 mass% or less, so that it has anti-pilling property, hardly causes sticking between fibers, and has high dyeability, high strength and productivity. A core-sheath type composite fiber can be provided.

FIG. 1 is a schematic cross-sectional view of a core-sheath type composite fiber in one embodiment of the present invention. FIG. 2 shows a nonwoven fabric obtained by performing needle-punching treatment on the card web composed of the core-sheath composite fiber of Example 1 and then hydroentanglement treatment, and dyeing the nonwoven fabric at 120 ° C. for 60 minutes. It is the photograph which observed the surface magnified 200 times with the scanning electron microscope, and was image | photographed. FIG. 3 shows a nonwoven fabric obtained by subjecting a card web made of the core-sheath composite fiber of Comparative Example 2 to needle punching and then hydroentangling, and dyeing the nonwoven fabric at 120 ° C. for 60 minutes. It is the photograph which observed the surface magnified 200 times with the scanning electron microscope, and was image | photographed. FIG. 4 shows the core-sheath composite fiber of Example 2 that was dyed under the following conditions (120 ° C., 60 minutes), and was then observed by enlarging the fiber side peripheral surface by 2000 times with an optical microscope (transmitted light). It is a photograph taken. FIG. 5 shows the core-sheath composite fiber of Example 2 that was dyed under the following conditions (120 ° C., 60 minutes), then observed with an optical microscope (transmitted light) at a magnification of 2000 times and photographed. It is a photograph.

  In the present invention, a polyester obtained by copolymerizing at least an aliphatic dicarboxylic acid component having a melting point of 180 ° C. or higher and 250 ° C. or lower is disposed as a core component. Polyester obtained by copolymerizing an aliphatic dicarboxylic acid component has the property of lowering the crystallinity of polyester and increasing toughness or stickiness, and is less likely to cause fibrillation (fibre lengthwise cracking). As a result, neither whitening nor pilling occurs. In addition, since the crystallinity is reduced, the dye is easily diffused, and dark dyeing is possible.

  The aliphatic dicarboxylic acid component is preferably an aliphatic dicarboxylic acid having 2 to 18 carbon atoms. More preferred is an aliphatic dicarboxylic acid having 2 to 10 carbon atoms. Specific examples include azelaic acid, succinic acid, adipic acid, sebacic acid, glutaric acid and the like. More preferred is adipic acid. This is because adipic acid is also used as a raw material for nylon and its cost is low. Particularly preferred is an ethylene terephthalate-adipate copolymer obtained by copolymerizing adipic acid.

The polyester may contain repeating units composed of an acid component and a glycol component described below.
[Acid component]
(1) terephthalic acid is 50 mol% to 90 mol% (2) sulfonic acid metal salt is 0.2 mol% to 6 mol% (3) aliphatic dicarboxylic acid is 4 mol% to 49.8 mol% [Glycol component]
(1) Ethylene glycol is 50 mol% or more and 99.9 mol% or less (2) Diethylene glycol is 0.1 mol% or more and 50 mol% or less

  As the polyester of the core component used in the present invention, those having a molecular weight used for ordinary clothing can be used. In the case of polyester, the molecular weight is usually expressed by replacing it with intrinsic viscosity. The intrinsic viscosity is specified in JIS K 7367-5. For example, 1 g of polyethylene terephthalate is dissolved in 100 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 6/4 (mass ratio), and 30 ° C. Measure with an Ubbelohde viscometer. Intrinsic viscosity [η] of about 0.58 to 0.70 is suitable for clothing. The weight average molecular weight is preferably about 10,000 to 100,000, more preferably about 30,000 to 800,000, and particularly preferably about 50,000 to 600,000.

  The core component polyester used in the present invention preferably has a glass transition temperature in the range of 40 ° C to 70 ° C. A more preferable lower limit of the glass transition temperature is 42 ° C. An even more preferable lower limit of the glass transition temperature is 44 ° C. A more preferable upper limit of the glass transition temperature is 68 ° C. An even more preferable upper limit of the glass transition temperature is 65 ° C. When the glass transition temperature of the polyester contained in the core component is less than 40 ° C., crystallization of the core component containing the polyester becomes difficult, and the spinnability may be lowered. When the glass transition temperature of the polyester contained in the core component exceeds 70 ° C., the crystallinity of the core component is remarkably increased, the dyeability is lowered, and the texture of the fiber and the fiber structure produced using the fiber is hard. There is a possibility of becoming.

  The core component polyester used in the present invention can be produced by a conventional polycondensation method using essentially ethylene glycol as the glycol component and essentially terephthalic acid and aliphatic dicarboxylic acid as the acid component. .

  In the acid component when polymerizing the polyester of the core component used in the present invention, the content of terephthalic acid contained in the acid component is preferably 50 mol% or more and 90 mol% or less. More preferably, it is 84 mol% or more and 90 mol% or less. The greater the amount of terephthalic acid, the higher the mechanical strength of the resulting polyester resin itself.

  The metal salt of sulfonic acid which may be copolymerized as an acid component when polymerizing the polyester of the core component used in the present invention is a metal salt of 5-sulfoisophthalic acid, a metal salt of 4-sulfoisophthalic acid, 4- Examples include metal salts of sulfophthalic acid, and metal salts of 5-sulfoisophthalic acid are preferable. The metal ion is preferably an alkali metal such as sodium, potassium or lithium and an alkaline earth metal such as magnesium. The most preferred metal salt of sulfonic acid is sodium salt of 5-sulfoisophthalic acid.

  The sulfonic acid metal salt contained in the acid component is preferably 0.2 mol% or more and 6 mol% or less. More preferably, it is 0.2 mol% or more and 1 mol% or less. This component is not only relatively expensive, but when used in an excessive amount, the polyester may become water-soluble and may affect the physical properties of the resulting polyester resin itself.

  The aliphatic dicarboxylic acid component unit in the acid component is 4 mol% or more and 49.8 mol% or less, preferably 4 mol% or more and 15 mol% or less. If the aliphatic dicarboxylic acid component is less than 4 mol%, the glass transition temperature cannot be lowered moderately. As a result, the crystallinity of the core component is remarkably increased, the dyeability is lowered, the fiber and There is a possibility that the texture of the fiber structure produced by using it becomes hard. On the other hand, when the aliphatic dicarboxylic acid component exceeds 49.8 mol%, the glass transition temperature is extremely lowered, and the fiber spinnability may be deteriorated. In place of dicarboxylic acid, an ester-forming derivative such as dimethyl ester of acid can also be used.

  It is preferable that ethylene glycol in the glycol component is 50 mol% or more and 99.9 mol% or less, and diethylene glycol is 0.1 mol% or more and 50 mol% or less. When the diethylene glycol unit exceeds 50 mol%, the single fiber strength of the fiber and the tensile strength of the spun yarn obtained using the fiber may be lowered. On the other hand, if it is less than 0.1 mol%, the crystallinity of the polyester tends to be high, the dyeability may be lowered, and the texture of the fiber and the fiber structure produced using the fiber may be hardened. is there.

  When the core component is mainly composed of the polyester copolymerized with at least the aliphatic dicarboxylic acid component, the polyester copolymerized with the aliphatic dicarboxylic acid component has a low crystallinity of the polyester. There is a tendency for stickiness to increase, and the core-sheath type composite fiber containing this polyester as a core component hardly causes fibrillation (cracking in the length direction of the fiber). As a result, neither whitening nor pilling occurs. In addition, since the crystallinity is lowered, the dye is easily diffused and dark dyeing becomes possible. In particular, the acid component is terephthalic acid in the range of 84 mol% to 90 mol%, the sulfonic acid metal salt is in the range of 0.2 mol% to 1 mol%, and the aliphatic dicarboxylic acid is 4 mol% or more. Glass transition with 15 mol% or less, glycol component within 50 mol% or more and 99.9 mol% or less, and diethylene glycol within 0.1 mol% or more and 50 mol% or less When an aromatic aliphatic polyester component (hereinafter also referred to as a high terephthalate polyester component) having a temperature in the range of 55 ° C. or higher and 70 ° C. or lower is used as a core component, it is mechanical when it is made into productivity, dyeability and spun yarn. A core-sheath composite fiber having excellent characteristics can be obtained.

  In the core-sheath composite fiber of the present invention, polyolefin is disposed as a sheath component. Polyolefins include polypropylene, polyethylene (including high density polyethylene, low density polyethylene, linear low density polyethylene), polymethylpentene, polybutene-1, and various olefins such as ethylene, propylene, butene, and pentene. And olefin-based elastomers mainly composed of various olefins and polyolefins. The polyolefin of the sheath component is preferably a polyolefin having a melting point of 100 ° C. to 250 ° C., more preferably at least one selected from polypropylene, polyethylene, polybutene-1 and polymethylpentene, particularly preferably polypropylene and / or polymethylpentene. Is most preferred. The polypropylene is not particularly limited, and for example, a homopolymer, a random copolymer, a block copolymer, or a mixture thereof can be used. Examples of the random copolymer and block copolymer include a copolymer of propylene and at least one α-olefin selected from the group consisting of ethylene and an α-olefin having 4 or more carbon atoms. The α-olefin having 4 or more carbon atoms is not particularly limited, but examples thereof include 1-butene, 1-pentene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, and 4,4-dimethyl. Examples include -1-pentene, 1-decene, 1-dodecene, 1-tetradecene, and 1-octadecene. The propylene content in the copolymer is preferably 50% by mass or more. Above all, it is selected from the group consisting of propylene homopolymer, ethylene-propylene copolymer and ethylene-butene-1-propylene terpolymer because of spinnability, stability of spinning process, and dyeability of the resulting fiber and yarn. And a propylene homopolymer is more preferable.

  The polypropylene as the sheath component preferably has a melt flow rate (MFR) of 25 g / 10 min or more and 60 g / 10 min or less. Within this range, there is no yarn breakage to the extent that actual production is possible, and stable spinning is possible. When the melt flow rate (MFR) is less than 25 g / 10 min, the fluidity at the time of melting of polypropylene tends to be low and yarn breakage tends to increase. On the other hand, when the melt flow rate (MFR) exceeds 60 g / 10 min, the viscosity at the time of melting of the polypropylene is lost, and yarn breakage tends to occur. The melt flow rate (MFR) is measured at 230 ° C. and 21.2 N according to JIS K 7210.

  Even if polypropylene is present in the sheath component, the polyester of the core component is dyed because the disperse dye permeates the polypropylene and diffuses into the polyester. Further, the presence of polypropylene in the sheath component makes it difficult for fibers to stick together.

  The polypropylene is preferably a copolymer containing a component copolymerizable in a range of less than 50 mol%, including a homopolymer of polypropylene and an ethylene-propylene copolymer. The proportion of the polypropylene resin contained in the polypropylene component is preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably substantially consists of only the polypropylene resin. A preferred upper limit is 100% mass. Here, the term “substantially” means that the resin provided as a product usually contains additives such as stabilizers and / or because various additives are added during the production of fibers, so that only polypropylene resin is used. It is used in consideration of the fact that it is not possible to obtain a fiber having a form containing no other components. Usually, the content of the additive is a maximum of 15% by mass.

  The polypropylene component may contain other polyolefin resin components in a range of less than 30% by mass, preferably in a range of less than 10% by mass. Other polyolefin resin components are, for example, polyethylene, polybutene, polymethylpentene, and the like. The polypropylene may be composed of two or more different polypropylenes. For example, by mixing two or more polypropylenes, a polypropylene having a melt flow rate (MFR) range of the present invention can be obtained.

  The composite ratio (core-sheath ratio) of the core component and the sheath component is preferably 35 to 75 mass% for the core component and 25 to 65 mass% for the sheath component when the core-sheath composite fiber is 100 mass%. Within this range, the obtained core-sheath composite fiber is less likely to be peeled off from the core component, and the core-sheath composite fiber has good dyeability and color developability. In addition, the quick-drying property, heat retention, etc. of the fiber structure using the core-sheath type composite fiber are enhanced. The composite ratio (core-sheath ratio) of the core component and the sheath component is more preferably, in mass%, core component: sheath component = 40-70: 60-30, and in mass%, the core component: sheath component = 40- It is particularly preferably 60:60 to 40, and most preferably 42 to 48:52 to 58. In addition, the specific gravity of polypropylene is 0.90 to 0.91, the specific gravity of polyester is 1.3 to 1.4 (measured by ASTM D792), and the specific gravity of the core-sheath composite fiber can be reduced within the above range. Furthermore, it can be set as the dyeable core-sheath type composite fiber.

  The composite ratio (core-sheath ratio) of the core component and the sheath component is preferably core / sheath = 67/33 to 27/73 in volume ratio. When the composite ratio is 67/33 to 27/73 (volume ratio), the above-described effect is easily obtained. The composite ratio of the core component and the sheath component (core / sheath) is more preferably 61/39 to 31/69 (volume ratio), particularly preferably 50/50 to 31/69 (volume ratio), 38/62 to 33 / 67 (volume ratio) is most preferred. Further, the shape of the fiber cross section of the core-sheath type composite fiber of the present invention is not particularly limited, and there are three shapes other than circular, for example, ellipse, Y shape, X shape, well shape, polygon, star shape, and convex portion. It may be an irregular shape such as a multi-leaf shape having ˜32, and may be a so-called hollow fiber having a hollow portion continuous in the length direction in a part of the fiber cross section.

  The method for producing the core-sheath-type conjugate fiber of the present invention comprises a core component and a sheath component melt-spun in a core-sheath state from a composite spinneret into an undrawn yarn, and a desired fineness for the obtained undrawn yarn. It is preferable to perform a stretching process to adjust the heat treatment, and then perform a tension heat set or a relaxation heat set (hereinafter, these steps and processes are simply referred to as heat set) as necessary. In the method for producing the core-sheath composite fiber of the present invention, the stretching treatment can be performed by a known stretching method. For example, wet stretching performed in a warm water bath, dry air or a heated metal roll is used. Examples include a stretching method such as dry stretching performed using, and steam stretching performed in a superheated steam atmosphere heated to a temperature of 100 ° C. or higher. Among these, in producing the core-sheath type composite fiber of the present invention, it is preferable to wet-draw in a warm water bath of 40 to 100 ° C, preferably in a warm water bath of 50 to 90 ° C. If it is said conditions, not only an undrawn thread | yarn can fully be extended | stretched but peeling of a core component and a sheath component cannot generate | occur | produce easily, and also hydrolysis of a polyester component can be prevented. The stretching ratio is preferably about 1.3 to 4.5 times. More preferably, it is 1.5-3.8 times, More preferably, it is 1.8-3.5 times. This is also to prevent peeling of the core component and the sheath component. A preferable manufacturing process is a process of drawing and drying through steps such as heat setting, crimping using a crimper and application of a fiber treatment agent to the fiber surface as necessary. Drying is performed in a dryer for about 15 minutes at a temperature of 90 to 120 ° C., more preferably at a temperature of 105 to 115 ° C. In order to make the core-sheath type composite fiber of the present invention into a spun yarn or a nonwoven fabric, it is stretched in a tow state, subjected to heat setting and drying processes as necessary, and then cut into a predetermined fiber length to obtain short fibers. . When making a filament, it is stretched, heat-set as necessary, and wound.

  In the method for producing the core-sheath composite fiber of the present invention, if necessary, a tension heat set or a relaxation heat set may be performed after stretching. This heat set can prevent shrinkage and relaxation in the subsequent process, and when producing spun yarn using this core-sheath type composite fiber, it can improve the processability in the spinning process. it can. The heat setting after stretching can be performed by a known method. Examples of the heat setting include hot water, a heated metal roll, dry air, or heat setting using heated steam. When manufacturing the core-sheath-type composite fiber of this invention, it is preferable to heat-set in a 70-100 degreeC hot water bath, or to perform with the dryer adjusted to the temperature of 100-115 degreeC. When performing the said heat setting in a 70-100 degreeC hot water bath, since it can simplify a manufacturing process, it is preferable if it performs immediately after the said extending process. The time for performing heat setting varies depending on the temperature at which the treatment is performed, but is preferably about 10 seconds to 30 minutes. When manufacturing the core-sheath-type composite fiber of this invention, the said heat setting may be performed only once (1 process), and may be implemented in multiple times, changing the same conditions or conditions.

  The fiber length of the core-sheath type composite fiber of the present invention is not particularly limited, and is cut to a fiber length suitable for the use of the core-sheath type composite fiber, but the range is 1-110 mm. When the core-sheath composite fiber of the present invention is used for spun yarn, the fiber length of the core-sheath composite fiber is preferably 24 to 75 mm, more preferably 28 to 65 mm, and 32 to 54 mm. Is particularly preferable, and 34 to 48 mm is most preferable. When the core-sheath type composite fiber of the present invention is used as a non-woven fabric or a batting material including a cushion material filled with short fibers, the fiber length is preferably 20 to 80 mm, more preferably 30 to 75 mm, 35 -65 mm is particularly preferable, and 40-55 mm is most preferable.

  The core-sheath type composite fiber of the present invention preferably has a single fiber strength of 1.8 to 5.0 cN / dtex, and more preferably 2.0 to 4 cN / dtex. When the single fiber strength is 1.8 cN / dtex or more, the fiber is difficult to break even when subjected to an external force (for example, spinning tension) when processing the fiber. Further, when the single fiber strength is 5 cN / dtex or less, a fiber having better anti-pilling property can be obtained. The single fiber strength of the core-sheath composite fiber of the present invention is particularly preferably 2.0 to 3.5 cN / dtex, and most preferably 2.2 to 3.2 cN / dtex.

  The core-sheath type composite fiber of the present invention preferably has an elongation of 10 to 70%, more preferably 20 to 60%, and particularly preferably 25 to 50%. It is preferable that the elongation is 10 to 70% because the core-sheath-type composite fiber has a low elongation within a range that does not impair the texture of the resulting fiber structure, and the processability and productivity in the spinning process are easily improved.

  The preferred single fiber fineness of the core-sheath composite fiber of the present invention is 0.4 to 20 dtex. Taking advantage of the characteristics of the core-sheath type composite short fiber obtained within this fineness range, various fiber structures, for example, spun yarns containing the obtained core-sheath type composite fiber were used to obtain woven or knitted fabrics. It is possible to use various types of batting materials by using the core-sheath type composite fiber, or various nonwoven fabrics containing the core-sheath type composite fiber. In particular, a woven or knitted fabric manufactured using a spun yarn containing the core-sheath composite fiber of the present invention satisfying the fineness range is flexible and suitable for clothing and the like. The fineness range suitable for the spun yarn including the core-sheath type composite fiber of the present invention and the woven or knitted fabric using the same is more preferably 0.4 to 3.5 dtex, and particularly preferably 0.6 to 2.5 dtex. 0.8 to 2.0 dtex is most preferable.

  Next, the fiber structure of the present invention will be described. The fiber structure of the present invention is a fiber structure comprising a core-sheath composite fiber or a fiber structure including the core-sheath composite fiber (A) and other fibers (B), wherein the core-sheath composite fiber The mixing ratio of (A) and other fibers (B) is in the range of 10 ≦ A ≦ 100 and 0 ≦ B ≦ 90 in terms of mass%. If it is this range, the characteristic of the core-sheath-type composite fiber of this invention can be utilized. Other fibers are acrylic fiber, polyester fiber, polyolefin fiber, nylon fiber, acetate fiber, acrylate fiber, ethylene vinyl alcohol fiber, urethane fiber, silk fiber, wool fiber, cashmere fiber, cotton fiber, hemp fiber, rayon fiber or An example is a cupra fiber. These fibers can also be used in combination or mixed. Examples of the fiber structure of the present invention include yarn, woven fabric, knitted fabric, non-woven fabric, stuffed cotton, and textile products.

  The yarn which is an example of the fiber structure can be produced by any method such as a ring method, an open end method, a bundling method, an alternating twist method, a wrapping method, a vortex method (MVS method), or a non-twist method. The preferred count in this case is an English cotton count in the range of 5 to 100S. A single yarn may be used or a plurality of yarns may be twisted together. When the fiber structure is a spun yarn, the fineness of the core-sheath composite fiber to be formed is preferably 0.4 to 3.5 dtex and the fiber length is 24 to 75 mm. If it is the said range, it will be easy to manufacture a spun yarn.

  The yarn preferably contains 10% by mass or more of the core-sheath composite fiber of the present invention. More preferably, it contains 20% by mass of the core-sheath type conjugate fiber of the present invention, and further preferably contains 50% by mass of the core-sheath type conjugate fiber of the present invention. A preferable upper limit is 100 mass%. A yarn containing 10% by mass or more of the core-sheath composite fiber of the present invention is excellent in heat retention, quick drying, and light weight.

  In addition to the core-sheath composite fiber of the present invention, the yarn may contain other fibers in a range of 90% by mass or less, preferably in a range of 80% by mass or less, and more preferably in a range of 50% by mass or less. For example, when the core-sheath composite fiber of the present invention is used for a yarn having a relatively low single fiber strength, it is preferably blended with other fibers in order to increase the strength of the entire yarn. The other fibers are not particularly limited, but may be those mentioned in the above-mentioned other fibers (B), and among them, acrylic fibers or polyester fibers are preferable. Acrylic fibers and polyester fibers are excellent in dyeability, fastness to washing and strength, and thus give strength to the yarn without impairing the characteristics of the core-sheath composite fiber of the present invention.

  The number of fibers constituting the yarn is preferably 90 or more, and more preferably 100 or more. A preferable upper limit is 500 pieces. When the number of fibers constituting the yarn is 90 or more, yarn breakage is difficult in the spinning process and the winding process.

  Even when the fiber structure is a knitted fabric, the structure, basis weight, density and the like are not particularly limited, and may be a flat knitted fabric, a rubber knitted fabric, a double knitted fabric or the like. The fiber structure may be a woven fabric.

For example, the following method can be used for combination or mixing with other fibers.
(1) Blending: Blending is a blending of two or more fibers at the cotton stage. For example, blending with mixed cotton, card, strips, sliver and the like. Used mainly for uniform mixing of yarn and nonwoven fabric.
(2) Combined yarn: Combined yarn is a mixture of two or more yarns twisted together. For example, in the case of twin yarn, it is a mixture in which the fiber yarn of the present invention and other fiber yarns are twisted together. Used for twisting spun yarns, spun yarns and filament yarns, and filament yarns.
(3) Mixed fiber: Mixed fiber is used when mixing fibers of filament yarns.
(4) Interweaving: Interwoven is a mixture when a plurality of types of yarns constituting a woven fabric are used to form a woven fabric. For example, different types of warp and weft may be used, or multiple types of warp and weft may be used.
(5) Knit: Knit is a mixture when multiple types of yarn are used when manufacturing a knitted fabric.
(6) A plurality of laminated fiber layers are mixed by needle punching and hydroentanglement in the production of a nonwoven fabric.

  When the fiber structure is a woven or knitted fabric, the fiber structure is preferably a woven or knitted fabric containing 10% by mass or more of the yarn containing the core-sheath composite fiber of the present invention. More preferably, the yarn containing the core-sheath conjugate fiber of the present invention contains 20% by mass or more, and more preferably, the yarn containing the core-sheath conjugate fiber of the present invention contains 30% by mass or more. A preferable upper limit is 100 mass%. Such a woven or knitted fabric is excellent in dyeability, heat retention, quick drying, and light weight.

  The woven or knitted fabric is preferably composed of a yarn containing the core-sheath composite fiber of the present invention and a yarn of another fiber. In this case, the woven or knitted fabric may contain other fibers in a range of 90% by mass or less, preferably in a range of 80% by mass or less, and more preferably in a range of 70% by mass or less. The form of other fibers may be any form such as yarn, monofilament yarn, multifilament yarn and the like. The other fibers may be those mentioned in the above-mentioned other fibers (B), and among them, polyester fibers or urethane fibers are preferable. Since the polyester fiber is excellent in dyeability, fastness to washing and strength, it gives strength to the yarn without impairing the characteristics of the fiber of the present invention. Moreover, since the urethane fiber is excellent in stretchability and contracts gently, a woven or knitted fabric imparted with stretchability can be obtained while utilizing the soft texture of the fiber of the present invention.

  The textile structure of the present invention also includes textiles such as clothing, bedding linings, blankets, rugs or carpets. Examples of clothing include underwear, underwear, shirts, jumpers, sweaters, pants, training wear, tights, stomachbands, mufflers, hats, gloves, socks, ear pads, and the like. It is also suitable for cold clothing, sportswear, stuffed cotton. Further, the surface of the fabric may be raised like a fleece.

  In the method for producing a fiber structure of the present invention, the fiber structure is dyed using a disperse dye in a temperature range of 110 to 130 ° C. Thereby, the dyed material dye | stained darkly can be obtained.

  The drawings will be described below. FIG. 1 is a schematic cross-sectional view of a core-sheath type composite fiber in one embodiment of the present invention. The core-sheath type composite fiber 1 is composed of a polyester core component 2 and a polypropylene sheath component 3. Although the core component (polyester) 2 is dyed and the sheath component (polypropylene) 3 is not dyed, the core-sheath composite fiber 1 as a whole appears to be dyed.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example.

The measuring methods used in Examples and Comparative Examples are as follows.
<Melt flow rate (MFR)>
It measured at 230 degreeC and 21.2N according to JISK7210.
<Intrinsic viscosity>
According to JIS K 7367-5, 1 g of polyester was dissolved in 100 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 6/4 (mass ratio) and measured at 30 ° C. using an Ubbelohde viscometer. did.
<Single fiber strength and elongation at break>
In accordance with JIS L 1015, using a tensile tester, the load value and elongation at the time of fiber cutting when the holding distance of the sample was 20 mm were measured, and the single fiber strength and fiber elongation were obtained, respectively.
<Number of crimps and crimp ratio>
It measured according to JIS L1015.
<Washing durability and dyeing fastness>
In order to evaluate the dyeability and dyeing fastness of the obtained core-sheath type composite fiber, washing treatment is performed on the dyed hydroentangled nonwoven fabric obtained by the method described later, and the washing durability of the core-sheath type composite fiber is obtained. And dyeing fastness was evaluated.
Laundry is performed on a dyed hydroentangled nonwoven fabric in a laundry test according to the Household Laundry 103 method defined in JIS L 0217. First, a sample cut to a size of 30 cm in length and 21 cm in width using a dyed hydroentangled nonwoven fabric is prepared. The mass of the prepared sample piece is measured, and a load cloth is prepared so that the sum with the mass of the test piece is 1 kg. The prepared test piece and the load cloth are put into a household washing machine and washed with a JAFET standard detergent for 25 minutes under the condition of 30 liters of water. Wash with water for 2 minutes after dehydration and dehydrate again. Wash again for 2 minutes and then dehydrate for 4 minutes. After performing this process twice, the sample piece is hung in the room and dried. The surface of the sample after drying was observed with the naked eye, and the color fastness was evaluated according to the following criteria.
++: Dyed in a dark color and little change in dyeing density before and after the washing process.
+: Dyed to the extent that it can be used, and there is little change in the dyeing density even before and after the washing treatment.
−: The staining density is insufficient. Further, color fading has occurred in the sample after the washing treatment.
Moreover, the surface of the hydroentangled nonwoven fabric after the washing treatment was observed with a scanning electron microscope, and the occurrence of core-sheath peeling was evaluated according to the following criteria.
+: The core-sheath composite fiber is not peeled off from the core-sheath composite fiber, or the occurrence of the core-sheath peeling is slight.
-: The core-sheath composite fiber was clearly peeled off on the nonwoven fabric surface, and some of the pills were generated.

(Examples 1-9, Comparative Examples 1 and 2)
<Polymer used>
The following polypropylene and polyester were used.
(1) PP-1 Sun Allomer Co., Ltd. trade name “PLA000A”, MFR: 45 g / 10 min (2) PP-2 Nippon Polypro Co., Ltd. trade name “SA03”, MFR: 30 g / 10 min (3) PP- 3 Product name “S105HG” manufactured by Prime Polymer Co., Ltd., MFR: 30 g / 10 min (4) PES-1 Product name “APEXA (registered trademark) 4027” manufactured by DuPont, USA, ethylene terephthalate-adipate copolymer, melting point: 235 ° C., intrinsic viscosity [η]: 0.63 (hereinafter, this polyester resin is referred to as “PES-1”)
(5) PES-2 manufactured by DuPont, USA Trade name “Apexa (registered trademark) 4024”, ethylene terephthalate-adipate copolymer (hereinafter, this polyester resin is referred to as “PES-2”)
(6) PTT US DuPont product name “Sorona (registered trademark)”, polytrimethylene terephthalate (hereinafter, this polyester resin is referred to as “PTT”)

<Manufacture of core-sheath type composite fiber>
Composite spinning was carried out under the spinning conditions shown in Table 1 to obtain a core-sheath type composite fiber, which was drawn to obtain a tow. The spinning conditions and the drawing conditions were as follows, and the conditions other than the following were summarized in Table 1.
(1) Spinning temperature: Polyolefin resin spinning temperature: 270 ° C., Polyester resin spinning temperature: 270 ° C.
(2) Stretching conditions: 3.0 to 3.5 times wet stretching in a hot water bath at 55 ° C. (3) Tension heat treatment set after stretching: Both ends were pressed with nip rolls in a hot water bath at 95 ° C. In the state, it was passed through a hot water bath at a draw ratio of 1.1 times, and tension heat setting was performed on the tow.
(4) Crimping: Crimping by mechanical compression using a crimper (5) Drying: Hot air drying for 15 minutes at 110 ° C. (6) Tow state (continuous fiber bundle state) from stretching to drying process Then, it was cut into a length of 38 mm.

<Dyeability evaluation>
The obtained core-sheath type composite fiber was dyed with a disperse dye and evaluated for dyeability. Evaluation of dyeability was evaluated by preparing a hydroentangled nonwoven fabric using the core-sheath type composite fiber obtained as follows and dyeing this.
(1) The obtained core-sheath type composite fibers of Examples 1 to 9 and Comparative Examples 1 and 2 were put into a parallel card machine, and a card web having a basis weight of 100 g / m ² made of these core-sheath type composite fibers and To do.
(2) A needle punching process is performed on the card web, a hydroentanglement process is performed on both surfaces, and the card web is dried to obtain a hydroentangled nonwoven fabric.
(3) Disperse dye (Nippon Kayaku Co., Ltd. Kayalon (registered trademark) Polyester Black): 8% owf (owf is an abbreviation of on the weight of fiber), dyeing assistant: 2 g / L Acetic acid: 0.5 cc / L, adjust the dyeing solution so that the bath ratio is 1:15, and dye at 120 ° C. for 1 hour.
(4) Reduction cleaning was performed on the nonwoven fabric dyed under the above dyeing conditions. Reduction cleaning is performed so that hydrosulfite (sodium dithionite): 2 g / L, sodium hydroxide (38Be): 4.5 cc / L, soaping agent: 2.5 g / L, bath ratio 1:15 Adjust and wash at 80 ° C. for 20 minutes.
(5) After the reduction cleaning was completed, it was thoroughly washed with water and dried.
(6) With respect to the dyed hydroentangled nonwoven fabric, the dyeing concentration and the core-sheath peeling were evaluated by the above procedure.

  When the core-sheath type composite fibers of Examples 1-9 and the core-sheath type composite fibers of Comparative Examples 1 and 2 were compared, the core-sheath type composite fibers of Examples 1-9 showed good dyeing fastness. It can be seen that a clear dark color is exhibited even after the washing test. In particular, the core-sheath type composite fibers of Examples 1 to 8 did not cause large fading even after the washing test. This is because the core-sheath type composite fibers of Examples 1 to 9 have an amount of 65% by mass or less of the total amount of the core-sheath type composite fibers despite the fact that the fiber surface is a polypropylene resin having no dyeability. The component, that is, the polypropylene covering the surface of the core-sheath type composite fiber has a thin film shape, and since the thickness of the polypropylene is thin, the disperse dye penetrates and permeates and dyes the highly dyeable core component polyester resin. It is guessed. In order to support this, FIG. 4 taken from the side peripheral surface of the core-sheath type composite fiber, and FIG. 5 taken a cross section of the core-sheath type composite fiber, a portion near the outside of the core-sheath type composite fiber, that is, polypropylene. Although the comprised part is not dye | stained, it can confirm that the center part of a core-sheath-type composite fiber, ie, the part comprised with polyester, is dye | stained darkly.

  On the other hand, although the core-sheath type composite fiber of Comparative Example 1 was subjected to a dyeing treatment, the dyeing concentration was thinner than the core-sheath type composite fibers of Examples 1 to 9, and it was difficult to use as dark clothing. It was a thing. This is because the ratio of polypropylene in the core-sheath composite fiber of Comparative Example 1 exceeded 65% by mass, the sheath component became too thick, and the ratio of polyester was less than 35% by mass. Although the polyester itself is dyed in a dark color, the core-sheath composite fiber as a whole is light in color, and it is considered that the polyester was not dyed in a dark color. On the other hand, the core-sheath type composite fiber of Comparative Example 2 showed a clear dark color even after the washing treatment, and showed high dyeing fastness. When the surface of the nonwoven fabric was confirmed with a scanning electron microscope, the core-sheath type composite fiber was So-called core-sheath peeling and fibrillation occurred in which the core component and the sheath component peeled off. In this core-sheath type composite fiber, since the ratio of the polypropylene resin constituting the sheath component is less than 25% by mass with respect to the core-sheath type composite fiber, the thickness of the polypropylene resin, that is, the sheath component is extremely thin. Become. As a result, the disperse dye can easily permeate the sheath component of the core-sheath composite fiber. As a result, although the dyeable resin existing inside the core-sheath composite fiber is easily dyed, the sheath component is easily broken, and the core-sheath is peeled off and fibrillated by an external force applied during the washing process. This is thought to be due to the increased likelihood of

2 to 5 are representative photographs of the fibers obtained in the examples and comparative examples.
(1) In FIG. 2, the card web made of the core-sheath composite fiber of Example 1 was subjected to needle punching and then subjected to hydroentanglement, and the nonwoven fabric obtained was dyed under conditions of 120 ° C. and 60 minutes. Then, it is the photograph which observed the nonwoven fabric surface magnified 200 times with the scanning electron microscope, and was image | photographed. As is clear from this photograph, it is understood that the fiber is not damaged such as fibrillation and has a good fiber shape.
(2) In FIG. 3, the card web made of the core-sheath composite fiber of Comparative Example 2 was subjected to needle punching, and then subjected to hydroentanglement, and the nonwoven fabric obtained was dyed at 120 ° C. for 60 minutes. Then, it is the photograph which observed the nonwoven fabric surface magnified 200 times with the scanning electron microscope, and was image | photographed. It can be seen that the fiber is damaged such as fibrillation.
(3) In FIG. 4, after dyeing the core-sheath type composite fiber of Example 2 under the following conditions (120 ° C., 60 minutes), the optical fiber (transmitted light) was used to enlarge the fiber side peripheral surface by 2000 times. It is a photograph that was observed and taken. The fibers were well dyed without any damage such as fibrillation.
(4) FIG. 5 shows the core-sheath composite fiber of Example 2 dyed under the following conditions (120 ° C., 60 minutes), and then observed with an optical microscope (transmitted light) at a magnification of 2000 times. This is a photograph taken. It can be seen that the fiber core component is well dyed.

  The core-sheath type composite fiber of the present invention is suitable for textile products such as clothing, bedding linings, blankets, rugs and carpets. Examples of clothing include underwear, underwear, shirts, jumpers, sweaters, pants, training wear, tights, stomachbands, mufflers, hats, gloves, socks, ear pads, and the like. It is also suitable for cold clothing, sportswear, stuffed cotton. Further, the surface of the fabric may be raised like a fleece.

1 Core-sheath type composite fiber 2 Core component (polyester)
3 sheath component (polypropylene)

Claims (9)

A core-sheath type composite fiber including a core component and a sheath component,
The core component is a copolyester having at least an aliphatic dicarboxylic acid component as a copolymer component and a melting point of 180 ° C. or higher and 250 ° C. or lower,
The sheath component is a polyolefin;
The core-sheath type composite fiber, wherein the sheath component is 25% by mass or more and 65% by mass or less when the core-sheath type composite fiber is 100% by mass.   The core-sheath-type conjugate fiber according to claim 1, wherein the copolymer polyester is an ethylene terephthalate-adipate copolymer.   The core-sheath-type conjugate fiber according to claim 1 or 2, wherein the single-sheath strength of the core-sheath-type conjugate fiber is 1.8 cN / dtex or more and 5.0 cN / dtex or less.   The core-sheath type composite fiber according to any one of claims 1 to 3, wherein the core component of the core-sheath type composite fiber is dyed with a disperse dye, and the sheath component is not dyed.   The core-sheath composite fiber according to any one of claims 1 to 4, wherein a volume ratio of the core component to the sheath component of the core-sheath composite fiber is core / sheath = 67/33 to 27/73. A fiber structure (A) comprising the core-sheath type conjugate fiber according to any one of claims 1 to 5, or a fiber structure comprising the core-sheath type conjugate fiber (A) and another fiber (B). And
A fiber structure characterized in that the mixing ratio of the core-sheath composite fiber (A) and the other fibers (B) is in a range of 10 ≦ A ≦ 100 and 0 ≦ B ≦ 90 in terms of mass%.   The fiber structure according to claim 6, wherein the fiber structure is at least one selected from a yarn, a woven fabric, a knitted fabric, a nonwoven fabric, stuffed cotton, and a fiber product.   8. The fiber structure according to claim 6, wherein the fiber structure is a spun yarn, the fineness of the core-sheath composite fiber constituting the spun yarn is 0.4 dtex to 3.5 dtex, and the fiber length is 24 mm to 75 mm. Fiber structure. It is a manufacturing method of the fiber structure given in any 1 paragraph of Claims 6-8,
A method for producing a fiber structure, wherein the fiber structure is dyed using a disperse dye in a temperature range of 110 to 130 ° C.