JP7356457B2 - Knitting cord and knitted products - Google Patents

Description

The present invention relates to a knitting cord containing an artificial leather base and a knitted product manufactured using the same.

BACKGROUND ART Artificial leather has been known that includes an artificial leather substrate including a nonwoven fabric and an elastic polymer material impregnated into the nonwoven fabric. Artificial leather is widely used as a surface material for footwear, bags, clothing, furniture, etc.

Strings obtained by shredding an artificial leather substrate are also known. For example, Patent Document 1 listed below discloses a lace that is made by cutting an artificial leather base into pieces with a width of 2 to 10 mm, and is used for manufacturing shoelaces, baseball glove laces, and the like.

Further, for example, Patent Document 2 below discloses an artificial leather having a silver-like resin layer on one surface of an artificial leather base including a nonwoven fabric containing fibers of 0.3 denier or less and a polymeric elastic material impregnated into the nonwoven fabric. Discloses a woven or knitted fabric using leather-like yarn obtained by shredding 0.5 to 1 mm in thickness and 1 to 5 mm in width.

In addition, Patent Document 3 below discloses an artificial leather having a silver-like resin layer on one side of an artificial leather base including a nonwoven fabric of ultrafine long fibers with an average fineness of 0.001 to 2 dtex and a polymer elastic material impregnated into the nonwoven fabric. The present invention discloses a string-like artificial leather product, which is obtained by cutting leather into pieces with a width of 2 to 10 mm and is used in the production of woven or knitted fabrics for interior products. However, although the string-like artificial leather product disclosed in Patent Document 3 has high strength, it has great flexibility and frictional resistance between the strings. Therefore, it was not suitable for manufacturing fine woven or knitted fabrics. Further, since the string-like artificial leather product disclosed in Patent Document 3 has excessively high strength, a strong load is applied to the needles of the knitting machine, which may cause damage to the equipment.

In addition, Patent Document 4 below discloses that an elastic warp-knitted base fabric consisting of elastic yarns and inelastic yarns whose fineness is thinner than the elastic yarns, artificial leather whose apparent fineness is thicker than the elastic yarns, and cloth are cut into tape shapes. The present invention also discloses an elastic warp-knitted fabric in which inelastic bulky yarns, which are tape yarns, in which fibers with a single yarn fineness of 30 dtex or less stand out from the cutting openings are knitted without forming knit loops.

By the way, in recent years, knits have been widely used as upper materials for sports shoes and the like. Upper materials for sports shoes are required to have a high level of functionality depending on their use. For upper materials using knits, by partially changing the structure of the knitted fabric, it is possible to partially develop functionality that meets requirements.

For example, U.S. Pat. No. 5,003,000 discloses an upper for an article of footwear including a knitted component having a base portion configured to be disposed in contact with a sole structure and an inlay knit extending through a base path. an extensible strand, the base portion defining an inner surface and an outer surface of the knitted component, and the base portion defining a base path between the inner surface and the outer surface. , disclose the upper. Yarns, cables, wires, threads, strands, filaments, fibers, threads, ropes, etc. are disclosed as extensible strands.

Further, Patent Document 6 listed below discloses a leather-like yarn having a silver surface on one side of a substrate made of ultrafine fibers and an elastic polymer. A string having such a silver surface has a high frictional resistance when the strings rub against each other during knitting, making it easy for the string to break, making it less practical.

JP2012-207353A Japanese Unexamined Patent Publication No. 59-150133 International publication 2008/120702 pamphlet JP2006-176908A Japanese Patent Application Publication No. 2018-118153 Japanese Unexamined Patent Publication No. 59-150133

As mentioned above, strings obtained by shredding an artificial leather substrate have been known for a long time. When performing knitting, which involves knitting a string obtained by shredding an artificial leather base, the knitting operation involves forming a new loop on a pre-formed loop and passing it through, and in inlay knitting, the string is hooked onto the hook of a knitting needle. When forming a loop by pulling it, the strings sometimes rubbed against each other and broke.

The present invention provides a knitting cord containing an artificial leather base that is less likely to be cut during the knitting process when a cord obtained by shredding an artificial leather base is used as a knitting cord, and a knitting cord produced using the same. The purpose is to provide knitted products.

One aspect of the present invention is a string including an artificial leather base, the artificial leather base comprising a nonwoven fabric that is an entangled body of ultrafine fibers with an average fineness of 0.5 dtex or less, and a polymeric elastic material impregnated into the nonwoven fabric. If the breaking strength (kg/cm) of the string is T, and the frictional resistance (kg) between the strings is S, then 10≧T≧4.6S+0.5, S<0.18 is satisfied. , a knitting cord preferably used for inlay knitting elements or stockinette knitting elements of knitted fabrics. Such a knitting cord is less likely to be cut during the knitting process, and therefore can be suitably used for inlay knitting elements or stockinette knitting elements.

Further, when the knitting cord further satisfies T≧12S+0.5, it is preferable since it is particularly difficult to cause breakage in the knitting process as an inlay knitting element or a stockinette knitting element.

Further, it is preferable that the knitting cord contains 0.1 to 2% by mass of a lubricant, since this reduces frictional resistance during the knitting process and makes it more difficult to break.

Further, it is preferable that the knitting cord has a suede-like surface because the frictional resistance in the knitting process is lowered.

Another aspect of the present invention is a knitted product including any of the knitting cords described above. Such knit products have novel designs that maintain a sense of fullness and suppleness.

According to the present invention, it is possible to obtain a knitting cord including an artificial leather base that is unlikely to be cut during the knitting process, and a knitted product manufactured using the same.

FIG. 1 is a schematic diagram of a knit product including a knitting cord according to an embodiment. FIG. 2 is a schematic diagram of a knit product using the knitting cord of the embodiment as an inlay knitting element. FIG. 3 is a graph plotting the results of Examples and Comparative Examples.

EMBODIMENT OF THE INVENTION One embodiment of a knitting cord including an artificial leather base according to the present invention and a knitted product manufactured using the same will be described in detail.

The knitting cord of this embodiment is a cord that includes an artificial leather base, and the artificial leather base includes a nonwoven fabric that is an entangled body of ultrafine fibers with an average fineness of 0.5 dtex or less, and a polymer that is impregnated into the nonwoven fabric. If the breaking strength (kg/cm) of the string is T, and the frictional resistance (kg) between the strings is S, then 10≧T≧4.6S+0.5, S<0. It is a knitting cord that satisfies 18 and is preferably used for an inlay knitting element or a stockinette knitting element of a knitted product.

First, the artificial leather substrate for producing the knitting cord will be explained in detail.

The nonwoven fabric included in the artificial leather base is an entangled sheet in which ultrafine fibers are three-dimensionally entangled. The type of ultrafine fibers forming the nonwoven fabric is not particularly limited. Specific examples include aromatic polyesters such as polyethylene terephthalate (PET), isophthalic acid-modified PET, sulfoisophthalic acid-modified PET, polybutylene terephthalate, and polyhexamethylene terephthalate; polylactic acid, polyethylene succinate, and polybutylene succinate. , polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate resin, and other aliphatic polyesters; nylons such as nylon 6, nylon 66, nylon 10, nylon 11, nylon 12, and nylon 6-12; polypropylene, polyethylene, Examples include fibers of polyolefins such as polybutene, polymethylpentene, and chlorinated polyolefins. These may be used alone or in combination of two or more.

Further, the ultrafine fibers forming the nonwoven fabric may contain colorants such as dyes and pigments, ultraviolet absorbers, heat stabilizers, deodorants, fungicides, various stabilizers, and the like, as necessary.

The average fineness of the ultrafine fibers forming the nonwoven fabric is 0.5 dtex or less, and is in the range of 0.0001 to 0.5 dtex, and even 0.001 to 0.2 dtex, to create a knit that has both suppleness and fullness. This is preferable from the viewpoint that a cord for use can be obtained.

Further, it is preferable that the ultrafine fibers forming the nonwoven fabric form fiber bundles of ultrafine fibers derived from ultrafine fiber-generating fibers, since a knitting cord having excellent breaking strength can be obtained. The number of ultrafine fibers forming the fiber bundle is not particularly limited, but it is preferably 5 to 70, more preferably 10 to 50, from the viewpoint of an excellent balance between flexibility and breaking strength.

The fiber length of the ultrafine fibers that form the nonwoven fabric is determined whether it is a short fiber that is intentionally cut after spinning, for example, a fiber length of about 3 to 100 mm, or a long fiber that is not intentionally cut after spinning (continuous fiber). Although long fibers may be used, long fibers are preferable because the degree of entanglement increases, which tends to increase the breaking strength of the string, and also provides a high sense of fulfillment. In the case of long fibers, the fiber length of the long fibers before being made into ultra-fine fibers is preferably 100 mm or more, and unless it is technically manufacturable and is not unavoidably cut in the manufacturing process, the length of the long fibers is preferably several meters or several meters. The fiber length may be 100 meters, several kilometers or more.

Specific examples of the elastic polymer that can be impregnated into the nonwoven fabric include polyurethane, (meth)acrylic elastic polymer, acrylonitrile elastic polymer, olefin elastic polymer, and elastic polyester. Can be mentioned. Among these, polyurethane is particularly preferred because of its excellent abrasion resistance. As described later, such a polymeric elastomer can be used in the form of an emulsion or solution to form a nonwoven fabric that is an entanglement of ultrafine fibers, or a nonwoven fabric that is an entanglement of ultrafine fiber generation type fibers to form ultrafine fibers. After being impregnated, it is applied by drying or wet coagulation using a poor solvent.

The mass ratio of the nonwoven fabric, which is an entangled body of ultrafine fibers, and the polymer elastic body (nonwoven fabric/polymer elastic body) is 99/1 to 55/45, and more preferably 95/5 to 60/40, which gives a sense of fulfillment. It is preferable because of its excellent balance with suppleness.

The artificial leather base of this embodiment preferably contains a lubricant for imparting lubricity to the surface of the knitting cord and reducing frictional resistance against knitting needles during knitting. Specific examples of lubricants include silicone softeners such as amino-modified silicone, alkyl silicone, amide-modified silicone, and epoxy-modified silicone, and vegetable waxes such as bee wax, carnauba wax, and candelilla wax; Animal waxes such as beeswax and wool wax; Mineral waxes such as montan wax; Petroleum waxes such as paraffin wax and microstalline wax; Waxes such as polyethylene wax, Fischer-Tropsch wax, and synthetic waxes such as fatty acid ester wax; Examples include silk protein. Among these, silicone-based softeners are preferred because they have a frictional resistance reducing effect and are easy to balance mechanical properties and texture.

In addition, the content of the lubricant in the knitting cord should be 0.01 to 3% by mass, more preferably 0.1 to 2% by mass, to ensure sufficient frictional resistance on the surface during knitting. This is preferable from the viewpoint of improving the processability of knitting by lowering the knitting temperature to . If the content of the lubricant contained in the knitting cord is too high, the breaking strength tends to decrease and processability tends to decrease.

In order to improve the strength of the artificial leather base as a knitting cord, the artificial leather base of the present embodiment may include a reinforcing material of the elastic polymer, which is applied as a finishing agent after the above-mentioned elastic polymer is applied. Specific examples of such reinforcing agents include polyurethane, (meth)acrylic elastomer, acrylonitrile elastomer, olefin elastomer, polyester elastomer, and the like. Among these, acrylic polymer elastic bodies are particularly preferred because of their excellent reinforcing properties and flexibility. Such a reinforcing agent is applied by impregnating a nonwoven fabric, which is an entangled body of ultrafine fibers, in the form of an emulsion or solution, and then drying it or wet-coagulating it using a poor solvent. In order to further enhance the reinforcing effect, the reinforcing agent is preferably impregnated between the fiber bundles of the ultrafine fibers.

In addition, the content of the reinforcing agent in the knitting string is 0.01 to 5% by mass, more preferably 0.5 to 3% by mass, increasing the strength of the knitting string and making it easier to knit. This is preferable from the viewpoint of improving the processing efficiency of the process. If the content of the reinforcing agent in the knitting cord is too high, flexibility tends to decrease and processability tends to decrease.

Next, a method for manufacturing the artificial leather substrate will be explained.

A nonwoven fabric that is an entangled body of ultrafine fibers is, for example, a web entanglement that is an entangled body that is a three-dimensional entanglement of a web of ultrafine fiber generation fibers such as sea-island composite fibers (hereinafter simply referred to as sea-island fibers). It is obtained by dissolving or decomposing only the sea component of the composite sheet. As the ultrafine fiber generation type fiber, in addition to the sea-island type fiber, a peelable and split type composite fiber or the like may be used. Alternatively, a nonwoven fabric that is an entangled body of ultrafine fibers may be produced by directly spinning the ultrafine fibers. In the present embodiment, as a representative example, a case in which sea-island type fibers are manufactured as ultrafine fiber-generating fibers will be described in detail.

Sea-island type fibers can be produced, for example, by a mixed spinning method in which two types of polymers that are not compatible are mixed and melted and then discharged from a spinneret, or in which two types of polymers that are not compatible are separately melted and each melt is It is spun using a composite spinning method in which materials are combined in a spinneret and discharged. Then, by dissolving or decomposing and removing the sea component of the obtained sea-island fiber, a fiber bundle of ultrafine fibers is formed. The number of islands in the cross section of the sea-island fiber is preferably 10 to 100, more preferably 15 to 50. Further, the mass ratio of the sea component to the island component is preferably 10:90 to 70:30.

The resin forming the island component is the resin for forming the ultrafine fibers mentioned above. Further, the resin forming the sea component is a resin that is removed after spinning the sea-island fiber, leaving behind the island component. The resin forming the sea component is, for example, a thermoplastic resin that can be dissolved and removed by water, an alkaline aqueous solution, an acidic aqueous solution, etc., and a resin that can be melt-spun is preferably used. Specific examples of the resin forming such a sea component include water-soluble polyvinyl alcohol resin (PVA resin), polyethylene, and the like.

In manufacturing a nonwoven fabric that is an entangled body of ultrafine fibers, a web made of sea-island fibers is first manufactured. Such a web can be manufactured, for example, by a spunbond method. Specifically, for example, a molten polymer to form sea-island fibers discharged from a spinneret is pulled and drawn at a speed of 2000 to 5000 m/min using a suction device such as an air jet nozzle, and then opened. It is manufactured by depositing it on a movable collection surface while spinning it. The fineness of the drawn sea-island fiber is preferably 1 to 4 dtex, more preferably 2 to 3 dtex.

Then, the obtained web is laminated into multiple layers using a known web laminating device (for example, cross-lap equipment) to form a laminated web, and then the laminated web is three-dimensionally entangled to form sea-island fibers. A web-entangled sheet is obtained.

The three-dimensional entanglement treatment of the stacked web is performed by needle punch treatment, high pressure water jet, or the like. In the case of needle punching, it is preferable to perform the needle punching under conditions such that at least one or more barbs penetrate from both sides simultaneously or alternately. Although the punching density is not particularly limited, it is preferably in the range of 300 to 5000 punches/cm ² , more preferably in the range of 500 to 3500 punches/cm ² . A web-entangled sheet is thus obtained.

The web-entangled sheet is preferably shrunk by wet heat shrinkage treatment to densify the sea-island fibers. The wet heat shrinkage treatment is preferably performed under wet heat conditions such as steam heating or hot water treatment. Processing under such moist heat conditions causes the web-entangled sheet to shrink.

In the production of artificial leather substrates, either before or after converting sea-island fibers into ultra-fine fibers, or both, the purpose is to prevent the ultra-fine fibers from slipping out, improve peeling strength, and give morphological stability and a sense of fullness. , an elastic polymer material is impregnated into the internal voids of a web entangled sheet or a nonwoven fabric that is an entangled body of ultrafine fibers after being formed into ultrafine fibers. As a method for imparting a polymer elastic material to the internal voids of a web entangled sheet or a nonwoven fabric that is an entangled body of ultrafine fibers after being made into ultrafine fibers, a polymer Examples include a method of applying an elastomer emulsion or solution by dip-nipping, impregnating with a knife coater, bar coater, or roll coater and coagulating the polymer elastomer. Among these methods, an emulsion or solution of a polymeric elastomer is applied to a web-entangled sheet or a nonwoven fabric that is an entangled body of ultrafine fibers after being made into ultrafine fibers using a dip nip, and then coagulated by drying or wet coagulation. is preferred.

Next, an explanation will be given of ultrafine fiber processing for extracting and removing the resin of the sea component in the sea-island type fibers of the web entangled sheet.

Ultra-fine fiber processing involves hot water heating treatment of the entangled web sheet with water, alkaline aqueous solution, acidic aqueous solution, etc. to dissolve or decompose and remove the resin forming the sea component, resulting in an entangled body of ultra-fine fibers. This is a process of forming a nonwoven fabric.

As a specific example of the conditions for the hot water heat treatment, for example, it is preferable to treat the web entangled sheet that has been subjected to the wet heat shrinkage treatment in hot water at 85 to 100° C. for 100 to 600 seconds. Further, in order to improve the dissolution efficiency of sea components, dip nip treatment, high pressure water jet treatment, ultrasonic treatment, shower treatment, stirring treatment, kneading treatment, etc. may be performed as necessary. It is preferable to repeat these operations as necessary.

When the sea component is removed from the sea-island type fibers by hot water heat treatment, the ultrafine fibers formed are greatly crimped. Since the fiber density becomes denser due to this crimping, a nonwoven fabric that is an entangled body of ultrafine fibers with a higher density is formed.

The thus obtained nonwoven fabric, which is an entangled body of ultrafine fibers, is preferably heated and stretched along the direction in which the ultrafine fibers are oriented. By such heating and stretching treatment, the ultrafine fibers are further oriented, and the ultrafine fibers are further stretched, thereby improving the breaking strength. For the heating and stretching treatment, conditions are selected such that, for example, the stretching treatment is performed at an ambient temperature of 80 to 130° C. while applying a load using a heating furnace such as a steam dryer or an infrared dryer.

In this way, an artificial leather substrate is obtained that includes a nonwoven fabric that is an entangled body of ultrafine fibers having an average fineness of 0.5 dtex or less, and an elastic polymer material impregnated into the nonwoven fabric. The artificial leather base may be further subjected to a known rubbing treatment or the like, if necessary. The kneading process can further improve flexibility.

The thickness of the artificial leather substrate is adjusted as necessary by slicing it into multiple pieces in a direction perpendicular to the thickness direction or grinding it. Furthermore, by buffing the surface, a suede-like surface, which is a raised surface, may be formed. Buffing is preferably carried out using, for example, sandpaper or emery paper of about 120 to 600 grit. It is preferable to have a suede-like surface because the frictional resistance against knitting needles during the knitting process is particularly low.

On the other hand, on the surface of the artificial leather substrate, a silver-like resin skin layer made of an elastic polymer such as polyurethane may be formed, if necessary. The resin skin layer can be formed using, for example, a dry surface forming method in which a polymeric elastomer sheet is dry-formed on a release paper and adhered to the surface of a nonwoven fabric using an adhesive, and then the release paper is peeled off, or a polymer sheet is formed on the surface of a nonwoven fabric using a dry surface forming method. After applying a solution of the elastic material, the nonwoven fabric is immersed in a coagulation bath to coagulate the polymeric elastic material on the surface of the nonwoven fabric, such as a wet surface forming method.

The thickness of the artificial leather substrate thus obtained is, for example, preferably 0.4 to 3.0 mm, particularly preferably 0.5 to 2.0 mm. In addition, the apparent density of the artificial leather base should be 0.2 to 0.7 g/cm ³ , more preferably 0.3 to 0.6 g/cm ³ , for an excellent balance between a sense of fullness and a supple texture. Preferable from this point of view.

Furthermore, it is preferable that the artificial leather substrate contains a lubricant. The method of impregnating and imparting the lubricant to the artificial leather base is not particularly limited, but for example, by impregnating the entire artificial leather base with a solution or dispersion of the lubricant and then drying, the fibers inside the artificial leather base or the high A lubricant can be applied to the molecular elastomer. Another method is to add a polymeric elastic material to an entangled web sheet or a nonwoven fabric that is an entangled body of ultrafine fibers by adding the polymeric elastic material to an emulsion or solution of the polymeric elastic material. It may be given at the same time.

It is particularly preferable to apply the lubricant by impregnating the artificial leather substrate in the form of a dispersion and then drying it. According to such a method, a lubricant can be applied to the entire artificial leather substrate. The lubricant dispersion is preferably prepared to a predetermined concentration, for example, about 0.1 to 20% by mass as solid content of the dispersion.

Further, the artificial leather substrate may be finished by adding a reinforcing agent as described above for the purpose of reinforcing the strength of the string. The method of impregnating and applying the reinforcing agent to the artificial leather substrate is not particularly limited. For example, by impregnating the entire artificial leather substrate with a solution or dispersion of the reinforcing agent and then drying it, the reinforcing agent can be applied to the fibers or polymer elastic body inside the artificial leather substrate.

It is particularly preferable to apply the reinforcing agent by impregnating the artificial leather substrate in the form of a dispersion and then drying it. According to such a method, the reinforcing agent can be applied to the entire artificial leather substrate. The reinforcing agent dispersion is preferably prepared to a predetermined concentration, for example, about 0.1 to 20% by mass as solid content of the dispersion.

The artificial leather substrate thus obtained is processed into a string by cutting it with a cutting machine or the like, for example, with a slit width of 0.5 to 3 mm, preferably 0.8 to 2 mm. In this way, a knitting cord, which is a cord containing an artificial leather base, is produced.

The aspect ratio (width/thickness) of the cross section of the knitting cord is preferably 0.7 to 2.5, more preferably 1 to 2. Note that the thickness is the thickness of the artificial leather base, and the width is the slit width when shredding the artificial leather. If the aspect ratio (thickness/width) is too low, the ultra-fine fibers will be cut too short when cutting the artificial leather base, resulting in uneven strength and easy to cut during the knitting process, and it will be too high. In some cases, the resulting knit product tends to have twisted portions, resulting in deterioration in appearance that looks like stitch defects.

The string of this embodiment obtained in this way has a breaking strength of 10≧T≧4.6S+0.5, where T is the breaking strength (kg/cm) and S is the frictional resistance (kg) between the strings. It is adjusted to satisfy S<0.18. During knitting, the braids rub against each other, creating frictional resistance. Braided cords made of artificial leather tend to have greater frictional resistance than ordinary spun yarns, because many microfiber cross sections exist in the cross section when the artificial leather is shredded. Furthermore, since the ultrafine fibers that make up the nonwoven fabric are cut to match the width of the string, the strength of string made from shredded artificial leather tends to be weaker than that of ordinary spun yarn. Excellent knitting properties can be ensured by using a string that satisfies the above-mentioned relational expression between breaking strength and frictional resistance between the strings. Further, when T≧12S+0.5 is further satisfied, it is preferable since it is particularly difficult to cause breakage in the knitting process as an inlay knit element or a stockinette knit element. Note that the intercept of 0.5 is a correction value derived from actually measured data in a region where the frictional resistance and breaking strength are low, since both the frictional resistance and breaking strength are theoretically not 0.

The breaking strength T (kg/cm) of the knitting cord is 0.5 to 10 kg/cm, more preferably 0.6 to 8 kg/cm, which makes the cord difficult to break during the knitting process. , is preferable from the viewpoint of maintaining sufficient flexibility. If it exceeds 10 kg/cm, the flexibility will decrease and the equipment will be more likely to be damaged due to excessive load being applied to the needles of the knitting machine.

Further, the elongation at break (%) of the knitting cord is preferably 50 to 300%, more preferably 60 to 250%, since the cord will be difficult to break during the knitting process.

Further, the frictional resistance S (kg) of the knitting cord is S<0.18, 0.02≦S<0.18, and furthermore, 0.025≦S≦0.16. This is preferable because it creates a string that is difficult to cut during the knitting process. Note that the method for measuring the frictional resistance S in this embodiment will be described in detail later.

The knitting cord of this embodiment is a cord that maintains a fullness and flexibility, and has excellent knitting process properties. By manufacturing a knitted product using such a knitting cord, it is possible to obtain a knitted product that retains a sense of fullness and suppleness and has a novel design.

FIG. 1 is a schematic diagram of a knitted product 10 including a knitting cord 1 according to an embodiment. Moreover, FIG. 2 is a schematic diagram of a knit product 20 using the knitting cord 1 as an inlay knitting element.

The knitted product 10 in FIG. 1 is a schematic diagram when the knitting cord 1 is knitted with rubber knitting, which is stockinette knitting. As stockinette knitting, in addition to rubber knitting, flat knitting, purl knitting, warp knitting, etc. can be employed without particular limitation. Further, the knitted product 20 in FIG. 2 is a schematic diagram in which conventionally known knitting yarn 2 such as wool or nylon yarn is stockinette-knitted, and the knitting cord 1 is used as an inlay knitting element. .

The above-mentioned knit products are manufactured using conventionally known circular knitting machines and weft knitting machines. The knitting cord of this embodiment is difficult to break during the knitting process because its breaking strength and frictional properties are regulated.

Next, the present invention will be explained in detail with reference to examples, but the scope of the present invention is not limited to the examples.

[Examples 1 to 6, 9 to 13, and Comparative Examples 1 to 6]
Water-soluble PVA is used as the sea component, PET with a degree of isophthalic acid modification of 6 mol% is used as the island component, and the number of islands per fiber is 25, so that the sea component/island component is 25/75 (mass ratio). A sea-island type filament was discharged from the spinneret at 260° C. using a melt composite spinning spinneret. Then, the ejector pressure was adjusted so that the spinning speed was 4000 m/min, and the sea-island fibers, which were continuous fibers with an average fineness of 2.5 dtex, were collected on the net, and a web of continuous fibers with a basis weight of 30 to 40 g/m ² was created. I got it.

The obtained web was cross-wrapped to stack 6 to 20 sheets, and an oil agent to prevent needle breakage was sprayed onto the web. Then, by needle punching with a 6-barb needle at a punch density of 2000 punches/cm ² , an entangled body of sea-island fibers with a basis weight of 300 to 850 g/m ² was obtained. Then, the entangled body of sea-island type fibers was heat-shrinked with water vapor. The heat-shrinked tangle of sea-island fibers was impregnated with a polyurethane emulsion, and then dried at 120° C. for 10 minutes.

Then, the polyurethane-impregnated tangle of sea-island fibers was immersed in hot water at 95°C for 10 minutes to remove sea components and form ultrafine fibers, and then dried at 120°C for 10 minutes. Both sides were then buffed with #240 and #320 sandpaper. In this way, a suede-like artificial leather substrate containing a nonwoven fabric of modified PET fibers with an average fineness of 0.07 dtex and 10% by mass of polyurethane was obtained.

After blanching the suede-like artificial leather base in hot water at 80°C for 20 minutes to allow it to blend in with the hot water and relax the fabric, it was dyed using a high-pressure jet dyeing machine (Hisaka Seisakusho Circular Dyeing Machine). dyed with disperse dye.

The resulting dyed suede-like artificial leather base was coated with amino-modified silicone (Softlon DX-1, manufactured by Yoshimura Yukagaku), fatty acid ester compound (Lastex LB, manufactured by Daikyo Chemical), or silk protein (Raku) as a lubricant. Luxet K-500 manufactured by Tokasei Co., Ltd.) with or without the addition of acrylic resin (Casesol ARS-2 manufactured by NICCA Chemical Co., Ltd.) as a reinforcing agent to achieve the solid content adhesion amount shown in Table 1. The sample was impregnated with an aqueous dispersion having an adjusted concentration and dried at 130°C.

The thus obtained suede-like artificial leather substrate with a thickness of 0.8 to 3 mm and an apparent density of 0.53 to 0.56 g/cm ³ is cut into a width of 0.7 to 3 mm in a direction parallel to the fiber orientation direction. I cut it into pieces and made string. Then, it was evaluated by the following method.

(1) Thickness and width of the string of the artificial leather base Measure the thickness of the string at five arbitrary points using a constant pressure thickness measuring device FFG-2 (manufactured by Ozaki Seisakusho, gauge diameter 5 mm, measuring force 0.8 N or less). and the width were measured and the average value was determined.

(2) Breaking strength of string (T)
The breaking strength (T) of the obtained string was measured as follows. A test piece was obtained by cutting one string into 10 cm in the length direction, and the stress at which the string broke was determined from the stress-strain curve using a tensile tester to determine the breaking strength (T). The distance between the chucks of the tensile tester was 50 mm, and the head speed was 50 mm/min.

(3) Frictional resistance of the string (S)
The frictional resistance (S) of the obtained string was measured as follows. Test pieces were prepared by cutting the string to be measured into lengths of 10 cm and 30 cm, respectively. Then, with the 10 cm string bent at the center and both ends of the string aligned, it was placed in the upper chuck of a tensile testing machine with the distance between the chucks set at 200 mm so as to form a loop of string approximately 3 cm in length. Next, one end of a 30 cm string was set in the lower chuck, and the other end was passed through the loop of the string set in the upper chuck, after which a 10 g weight was suspended. Stress is measured at a head speed of 100 mm/min within a head movement distance of 100 mm, the maximum load is read from the obtained chart, and the value obtained by subtracting 20 g of the load applied to both ends of the string is the frictional resistance (S). And so.

(4) Fineness of ultrafine fibers A vertical cross section of the suede-like artificial leather in the thickness direction was observed with a scanning electron microscope (SEM) at a magnification of 100 to 500 times to obtain an image. Then, the cross-sectional areas of the ultrafine fibers constituting 10 fiber bundles evenly selected from the images were determined and averaged. Then, the average fineness of the ultrafine fibers was determined from the obtained average cross-sectional area and specific gravity of polyester (1.38 g/cm ³ ).

(5) Knitting property of stockinette knitting The obtained string was run on a flat knitting machine with appropriate settings between 3 and 10 gauges depending on the condition of the string, such as thickness and hardness, to produce stockinette knitting. The knitted fabric had a width of 400 mm and was evaluated as follows according to the number of times the string was cut when 5 m of fabric was produced.
A: No cleavage occurred.
B: Cutting occurred 1 to 3 times.
C: Cutting occurred four or more times.

(6) Inlay knitting properties When using a flat knitting machine that is capable of inlay knitting, when knitting 18 count double yarn with a single thread on a 10 gauge flat knitting machine, pass the resulting string through every third cross stitch. I did inlay knitting. The knitted fabric had a width of 400 mm and was evaluated as follows according to the number of times the string was cut when 5 m of fabric was produced.
A: No cleavage occurred.
B: Cutting occurred 1 to 3 times.
C: Cutting occurred four or more times.

(7) Appearance of stockinette knitting Using the knitted fabric prepared for checking the knitting properties in (5) and (6), thread twisting occurred in an arbitrary 300 mm x 300 mm area, resulting in uneven stitches. The number of locations where the sample was removed was counted, the average of the five locations was taken, and the judgment was made as follows.
A: The number of uneven stitches was one or less.
B: Non-uniform stitches were formed in 2 to 3 places.
C: Non-uniform stitches were formed at 4 or more locations.

The results are shown in Table 1 below.

[Example 7]
In Example 1, the process was carried out in the same manner as in Examples 1 to 6, except that instead of the nonwoven fabric of modified PET fibers with an average fineness of 0.07 dtex, a nonwoven fabric of modified PET fibers with an average fineness of 0.3 dtex was formed. A dyed suede-like artificial leather substrate with a diameter of 1.4 mm was obtained. Then, it was cut into pieces with a width of 1.0 mm to create strings and evaluated. The results are shown in Table 1.

[Example 8]
A strand of 50 parts by mass of polyethylene as a sea component and 50 parts by mass of nylon 6 as an island component was melted so that the number of islands was 25, and the mass ratio of sea component/island component was 50/50. It was discharged from a melt composite nozzle having a nozzle. Then, the air pressure of the air jet suction device installed directly below the spinneret was adjusted so that the spinning speed, which was indirectly determined from the ratio of the discharge amount per unit time and the fineness of the obtained long fibers, was 3600 m/min. The molten strand discharged from the spinneret was pulled and cooled while being thinned, thereby spinning long sea-island fibers with a fineness of 2.9 dtex. After the obtained sea-island fibers were continuously collected on a mobile net installed directly below the suction device, they were pressed using a metal roller with a surface temperature of 60°C to produce long fibers with a basis weight of 22 g/ ^m2 . A fibrous web of sea-island type fibers was obtained.

The obtained web was cross-wrapped to stack 16 sheets, and an oil agent to prevent needle breakage was sprayed onto this web. Then, after needle punching was performed with a 6-barb needle needle at a punch density of 2000 punches/ ^cm2 , the fabric weight was A tangle of sea-island fibers weighing 600 g/m ² was obtained.

Then, the entangled body of sea-island fibers was impregnated with a solution consisting of 18 parts by mass of a polyurethane composition mainly composed of polyurethane and 82 parts by mass of DMF, and the polyurethane was coagulated and washed with water. Then, by extracting and removing the polyethylene in the sea-island type fibers, an artificial leather substrate containing polyurethane and a nonwoven fabric of ultrafine fibers of polyamide 6 in the form of fiber bundles of long fibers was obtained. Both sides were then buffed with #240 and #320 sandpaper. In this way, a suede-like artificial leather substrate containing a polyamide 6 nonwoven fabric with an average fineness of 0.03 dtex and 30% by mass of polyurethane was obtained.

A suede-like artificial leather base was blanched in hot water at 80° C. for 20 minutes to blend it with the hot water and relax the fabric, and then dyed with a metal-containing dye using a wince dyeing machine.

Next, as shown in Table 1, a suede-like artificial leather substrate having a thickness of 1.0 mm and an apparent density of 0.40 g/cm ³ was obtained by impregnating with 0.71% by mass of amino-modified silicone.

The thus obtained suede-like artificial leather substrate was cut into pieces with a width of 1.0 mm in a direction parallel to the fiber orientation direction to prepare strings. Then, it was evaluated in the same manner as in Example 1. The results are shown in Table 1.

FIG. 3 is a graph plotting the results of Examples and Comparative Examples. As shown in Fig. 3, the cords obtained in the examples satisfying 10≧T≧4.6S+0.5, S<0.18 all had stockinette knitting properties and inlay knitting properties of B or higher. . Furthermore, the strings of Examples 1 to 8 that further satisfied T≧12S+0.5 were also A in both stockinette knitting properties and inlay knitting properties.

1 Knitting cord 2 Yarn 10 Knitted product knitted with stockinette knitting cord 20 Knitted product containing inlay elements

Claims (6)

A string including an artificial leather base,
The artificial leather base includes a nonwoven fabric that is an entangled body of ultrafine fibers with an average fineness of 0.5 dtex or less, and a polymeric elastic material impregnated into the nonwoven fabric,
When the breaking strength (kg/cm) of the string is T, and the frictional resistance (kg) between the strings is S,
A knitting cord that satisfies 10≧T≧4.6S+0.5, S<0.18. The knitting cord according to claim 1, further satisfying T≧12S+0.5. The knitting cord according to claim 1 or 2, containing 0.1 to 2% by mass of a lubricant. The knitting cord according to any one of claims 1 to 3, wherein the lubricant is a silicone softener. The knitting cord according to any one of claims 1 to 4, having a suede-like surface. A knitted product comprising the knitting cord according to any one of claims 1 to 5.

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