JPH034669B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to artificial leather with excellent clothing properties. More specifically, the present invention relates to artificial leather that is flexible, has excellent mechanical strength, does not fray at the edges, and can be cut and sewn. BACKGROUND OF THE INVENTION Conventionally, artificial leather in which a nonwoven fabric using ultrafine fibers is filled with an elastic polymer is widely known, as seen in Japanese Patent Publications No. 49-48583 and Japanese Patent Publication No. 51-6261. However, the base material of these artificial leathers is mostly non-woven fabric in which ultrafine fibers of 0.2 denier or less are intertwined in a three-dimensional manner, so the mechanical strength of the base material is so low that it cannot be used as clothing. For this purpose, a large amount of elastomeric polymer is usually impregnated into the nonwoven substrate. As a result, the softness and drape properties of nonwoven fabrics are lost, resulting in only the hard, fluffy texture characteristic of elastic polymers. Furthermore, in order to obtain artificial leather with drape properties and a soft texture, it is necessary to reduce the amount of elastomeric polymer filled or actively impart a foam structure to the filled elastomeric polymer. In such cases, the mechanical strength of the elastic polymer does not have a sufficient reinforcing effect, and although the resulting artificial leather is flexible, its elongation and tear strength do not reach a level that can be used as clothing, and the elongation recovery is poor. It also had disadvantages such as poor elasticity and the elbows coming off when worn. As a result of conducting studies for the purpose of further improving the suitability of such artificial leather for clothing, the present applicant previously proposed Japanese Patent Application No. 55-98730. The main composition of the improved artificial leather proposed in this proposal is a sheet-like material mainly made of ultrafine fibers, textiles, and elastic polymers, and the textile is false-twisted with a twist of 200 to 1200 T/m. It uses thread. Artificial leather having this structure has greatly improved the disadvantages of clothing properties such as tear strength, seam strength, and fraying of the fabric during cutting, and has brought about beneficial results. However, it has been found that such artificial leather also has new problems. In other words, products that are cut and sewn, or parts that are used as they are cut (patchwork)
When dry-cleaning or laundering is repeated on dry-cleaned clothing, the fabric frays from the cut surface, which necessitates selvage stitching, which severely limits its uses. In addition, the seam strength is still insufficient, and if you continue to wear it for a long time, stress will concentrate.
A problem was discovered in which the seams at such locations were misaligned. The present inventors pursued the cause of these problems and further investigated improvements to the textile, and as a result, they arrived at the present invention. That is, the present invention provides an artificial leather in which an elastic polymer is contained in the interstitial spaces of an intertwined body in which ultrafine fibers of 0.5 denier or less cover at least one side of the woven fabric and are intertwined with the woven fabric. is made of multifilament and false twisted yarn with a single yarn thread density of 3 denier or less, and the false twisted yarn has a thread density of 0 to 199.
This artificial leather is twisted at a rate of twists per meter, has a total denier of 50 to 150 deniers, and has a woven thread density of 60 to 250 threads/inch. The first point of the artificial leather according to the present invention lies in the design of the fabric inside or on the back side of the tangled body used as the base. In this sense, a detailed explanation of the present invention will be given from the perspective of textiles. In the present invention, the form of the yarns constituting the fabric is 0 to 0.
Multifilament false twisted yarn with 199 twists per meter, especially untwisted or 1m
It is preferable to have 100 twists or less per twist. In the case of multifilament false-twisted yarn whose constituent raw yarn is twisted more than 200 times per meter or multifilament straight yarn that has not been subjected to false twisting, the resulting artificial leather cut-and-sewn product is cut off. If partially used clothing is repeatedly dry cleaned or washed, fraying will occur. Moreover, if the strength of the seams is insufficient when sewing with a sewing machine, and stress exceeding a predetermined level is applied to the seams during wear, a problem arises in that the seams become misaligned. Observing the internal structure of the sheet-like product of the present invention,
In the case of multifilament with a twist number of 200 times/meter or more, the fibers constituting the fabric are bundled by twisting, and the degree of entanglement between the ultrafine fibers and the fibers constituting the fabric is low. In the case of multifilament false twisted yarn,
It can be seen that the twisting is small and the false twisting process increases the single fiber looseness, the voids between the fibers that make up the fabric are large, and the ultrafine fibers and the fibers that make up the fabric are intertwined relatively firmly. It is thought that as a result of strengthening the fixation of the fibers constituting the fabric inside, the occurrence of fraying was suppressed and the seam strength was also increased. In addition, even if fraying of the fabric occurs from the cut surface of the artificial leather of the present invention, it will not be noticeable because the single threads of the multifilament are loose due to the false twisting system with a small number of twists. Not. In the present invention, cut-cut sewing is possible only by applying a fabric made of multifilament false-twisted yarn, which is untwisted or twisted at a rate of 199 times/meter or less. It has now become possible to provide artificial leather with extremely high strength. Furthermore, when the multifilament and the number of twists are reduced, on the other hand, the tear strength of the leather decreases, but this problem can be solved, for example, by using a false twisted yarn with high toughness, or by using a false twisted yarn with a relatively large total denier. It has been found that this problem can be solved by increasing the breaking energy per unit length of the leather, such as by using a fabric with a relatively high thread density. The woven fabric in the present invention is preferably made of multifilament having a single fiber fineness of 3 deniers or less. The fineness of the fibers that make up the fabric is closely related to the flexibility of the leather, and if the fabric is made of single fibers that exceed 3 deniers, the texture of the resulting artificial leather will be hard and core-like. When the denier is 3 denier or less, the resulting fabric will be highly flexible and the leather will also be flexible. Furthermore, even if fraying of the fabric occurs from the cut surface of the leather, if it is less than 3 deniers, it will be difficult to see, so there is an advantage that the same effect as that of one with substantially no fraying can be obtained. From this point of view, a denier of 2 denier or less is particularly preferable. The material for the multifilament fabric is not limited, but polyethylene terephthalate (PET)
Synthetic fibers such as nylon 6, nylon 6.6, polyacrylonitrile, and polypropylene, and recycled fibers such as rayon and cupra rayon are applicable, and among the synthetic fibers, PET is particularly preferred. Further, the false twisted yarn may be produced by a known manufacturing method such as a spindle method, a friction method, a one-heater type, a two-heater type, or the like. When twisting the false twisted yarn, a normal twisting machine is used. The twist direction may be either S twist or Z twist. Examples of the texture of the textile include plain weave, twill weave, satin weave, and patterned weave, but plain weave is preferable from the viewpoint of surface smoothness of the leather and cost. The yarn density, multifilament and total denier of the fabric are relatively important in the present invention. That is, the higher the thread density, the higher the tear strength of the resulting leather. On the one hand, this tear strength also depends on the total denier of the multifilament; for fabrics of the same thread density, the higher the total denier, the higher the tear strength. On the other hand, it is not preferable to increase the thread density or total denier too much because the flexibility of the resulting leather will be impaired.
The combination within the range of the present invention is such that the multifilament has a toral denier of 50 to 150 deniers and the woven fabric has a yarn density of 6.0 to 250 threads/inch (density of light yarns and weft yarns). In addition, in order to impart higher tear strength to the artificial leather of the present invention, the toughness of the twisted yarn: T _S ×
√ _E (T _S is yarn strength g, T _E is yarn elongation %)
More preferably, it is 1250 or more. The ultrafine fiber, which is one of the important elements constituting the present invention, has a single fiber fineness of 0.5 denier or less, preferably 0.3 denier or less. If the denier is greater than 0.5 denier, the flexibility will be poor and the writing effect of brushed leather will not be expressed, and the product value as high-grade artificial leather will be lost.If the denier is 0.5 denier or less, the flexibility and graceful writing effect will be achieved for the first time. The material for the ultrafine fibers is not particularly limited, and synthetic fibers such as polyester, polyamide, and polyacrylonitrile, and recycled fibers such as rayon and cupra rayon can be used, but dyeing is required to make them the same as the material used for textiles. From this point of view, it is preferable, and PET is particularly preferable. The ultrafine fibers may take the form of either long fibers or short fibers. However, from the viewpoint of interlacing and integrating with the fabric, short fibers are preferred. In addition, ultrafine fibers may be separated into single fibers, bundled, or a mixture of single fibers and fiber bundles of various sizes, but depending on the density of the surface, In order to achieve excellent writing effects, it is preferable that the fiber be in the form of a single fiber. Furthermore, it is important for the purpose of the present invention that the ultrafine fibers are sufficiently three-dimensionally intertwined and integrated with each other and with the fabric. The intertwining in the present invention is mainly performed by the ultrafine fibers entering the interweave gaps of the fabric, but at the same time, some of the ultrafine fibers also enter the filament gaps of the multifilament constituting the fabric. In the present invention, the higher the degree of entanglement, the better. Furthermore, the intertwining between the ultrafine fibers is important for the condition of the nap on the surface when suede-like artificial leather is produced by raising it. If the ultrafine fibers are insufficiently intertwined, the nap will be long and have a low density, making it impossible to obtain a good lighting effect. The elastic polymer constituting the present invention is important for gripping the roots of fluff when raised, imparting firm flexibility unique to natural leather, and fraying resistance. A suitable proportion of the elastic polymer is 30 to 60% by weight based on the fiber components (ultrafine fibers + textile fibers) in the artificial leather. There are no particular restrictions on the type of elastic polymer, but polyurethanes are particularly preferred since they provide the product of the present invention with preferable flexibility. The composition of polyurethane is
As a polyol component, polyester diols such as polyethylene adipate glycol and polybutylene adipate glycol, polyether glycols such as polyethylene glycol and polytetramethylene glycol; as an isocyanate component, aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate, and dicyclohexyl. Lipid-reduced diisocyanates such as methane-4,4'-diisocyanate, aliphatic diisocyanates such as hexamethylene diisocyanate; As chain extenders, glycols such as ethylene glycol, diamines such as ethylene diamine, 4,4'-diaminodiphenylmethane, etc. etc. can be used in appropriate combinations. Next, it is preferable that the elongation of the artificial leather of the present invention under a load of 1 kg is within a specific range of 3 to 20% in the warp direction and 5 to 40% in the weft direction. Furthermore, sutra 6 to 15
%, latitude 8 to 25% is particularly preferred. Less than 3% in longitudinal direction and/or 5% in latitudinal direction
It has become clear that if it is less than 100%, the characteristics of the garment will be extremely poor, such as poor swarming properties and seam puckering when sewing the garment, making it impossible to obtain clothing that looks well-tailored. 20% or more in longitudinal direction and/or 40% in latitudinal direction
If the elongation is above, sewing characteristics such as sagging and seam puckering will be good, but for example, if clothes made from artificial leather with such elongation are left hanging on a hanger, If you leave it on, it may stretch and not return, or when you wear it, the elbow area may stretch and not return, causing it to "fall out".
Phenomena such as drying are observed, and in the end only a product with extremely poor elongation recovery properties is obtained. It has been found that the fact that artificial leather has elongation in such a specific range also has the surprising effect of making the texture extremely soft. In the case of the artificial leather of the present invention, the elongation of the leather depends on the elongation of the entangled body, and the elongation of the entangled body depends on the elongation of the fabric that is a component of the entangled body, that is, the elongation of the leather. As a result of the study, it became clear that the elongation of the fabric depends on the elongation of the fabric. It can also be said that the elastic polymer does not substantially determine the elongation of the leather. This can be done by extracting and removing the elastic polymer from the artificial leather of the present invention using its solvent, measuring the elongation of the remaining entangled body, and then separating it by pulling out the ultrafine fibers from the entangled body. This can be easily determined by measuring the elongation of the leather and comparing it with the elongation of the leather measured in advance. Next, an example of the method for producing artificial leather of the present invention will be explained. First, the multifilament false twisted yarn is made into a woven fabric, either as it is or by twisting it at less than 199 twists per meter. Next, this fabric is made to have elongation within a specific range, if necessary. This makes it possible to adjust the elongation of the leather of the invention. A preferred method for imparting elongation to textiles is
A method is used that utilizes the development of elongation due to shrinkage of the false twisted yarn in hot water, for example, a method in which the fabric is shrunk by hot water treatment, then stretched to a predetermined size and heat set. Elongation depends on the temperature of hot water treatment,
It can be easily controlled by a combination of time, elongation rate during heat setting, setting temperature, etc. Next, a sheet made of ultra-fine fibers is made. As a method for obtaining ultrafine fibers, conventionally known methods can be applied. For example, latent ultrafine fiber methods such as the sea-island fiber method and mixed fiber method, direct spinning methods as typified by Japanese Patent Application No. 40519/1983, and melt blowing methods can all be used as methods for obtaining the ultrafine fibers of the present invention. can. This can be easily made into a sheet by cutting or not cutting the microfibers and making a non-woven web by card cross layering, by papermaking method, or by directly making it into a web by melt blowing. . The fabric is inserted between the ultrafine fiber sheets obtained in this way or is attached to the back side of the sheets and subjected to a subsequent entangling process. The intertwined state of the present invention can be obtained by adjusting the intertwining method and conditions depending on the properties of the ultrafine fibers and the fabric. Using short fibers of about 3 to 10 mm that are made into ultra-fine fibers, the number of additional twists is 0 to 199 as a fabric.
Fabric weight of 20 to 100 times per meter of false twisted yarn
When using a plain weave fabric of about g/m ² , it is preferable to use a columnar water jet ejected from a pore nozzle as the entangling means. For example, the conditions are:
It is preferable to apply a columnar water stream at a pressure of 1 to 30 Kg/cm ² from a multi-pore nozzle with a nozzle diameter of 0.05 to 0.5 mm to the front and back surfaces of the sheet without any corners. In addition to this, a needle punch method can also be used as the entangling method. Next, the entangled body is fluffed if necessary. As a means for fluffing, conventionally known means such as emery paper, cloth, a brush, etc. can be used. Fluffing can be done before or after impregnating the elastomeric polymer. As a method for filling the entangled body with a polymer, there is a method of impregnating and coagulating an elastic polymer using a conventionally known dry coagulation method or wet coagulation method. When polyurethane is used as a preferred example of the elastic polymer, dimethylformamide (DMF) is used as the preferred solvent, and water or water is used in the coagulation bath during wet coagulation.
DMF-based solvents are preferably used. It is also good to add coloring agents such as pigments and dyes to polyurethane. Finally, this is dyed and the formed nap is preferably styled with a brush or the like to obtain the artificial leather of the present invention which has good lighting effects and excellent clothing properties. The present invention will be specifically explained below using Examples.
The measurement method used in the following examples was as follows. (1) Elongation: The elongation rate under a load of 1Kg/cm is JISL-
Values measured in accordance with 1079C. (2) Flexibility: Value determined by JISL-1079 cantilever method. (3) Seam strength: Compliant with JISL-1093. Measured under dry conditions. (4) Tear strength: Compliant with JIS 1079c pendulum method. (5) Sewing properties: Evaluated by seam buckling properties and sagging properties. Regarding seam buckling, two test pieces 10 cm wide and 30 cm long were sewn together to form a curve with a curvature of 0.04 cm ^-1 to match the side lines of men's clothing, and the results were visually judged as shown in Table 1. It was evaluated using the following evaluation criteria. Regarding the sagging property, the samples were actually applied to the sewing process and evaluated according to the evaluation criteria shown in Table 1.

[Table] (6) Frayability A sample cut with scissors as shown in the drawing was added to the Mitsubishi Permac Dry Cree + MC-9 type (Mitsubishi Heavy Industries KK) containing 150 noperchlorethylene. (manufactured by the company) was introduced. The washing conditions were a cycle of 8 minutes of washing, 5 minutes of centrifugal dehydration, and drying (60° x 20 minutes) five times. The evaluation was performed by visually determining the presence or absence of fraying of the fabric from four cut surfaces of the sample after treatment. Example 1 A drawn yarn of 100 denier/48 filament polyethylene terphthalate (PET) was false-twisted 3000 times/meter (added S twist, untwisted Z twist), and then the false twisted yarn was Thread density of warp and weft is 60 each
It was woven into a plain weave so that the length per inch was woven. This fabric was relaxed in hot water at 95°C for 30 minutes, and after drying, it was stretched to a yarn density of 71 threads/in.
Heat set at 180°C. 1Kg of the obtained fabric/
The elongation under cm load was 15% in each direction. Separately from textiles, by the method of patent application 1984-40519.
A 0.1 denier ultra-fine drawn PET yarn is made, cut into 3 mm pieces, and a 1 denier, 3 mm cut yarn of polyvinyl alcohol (PVA) is made from PET/PVA.
Mix at a ratio of TVA = 80/20 and use the papermaking method to obtain 100%
A mixed sheet of g/m ² was obtained. The previously prepared woven fabric was placed on top of this mixed paper sheet, and the above-mentioned mixed paper sheet was further placed on top of this to form a three-layer sandwich sheet. A high-pressure water stream with a pressure of 20 kg/cm ² is sprayed onto this three-layer sheet from a nozzle with an orifice of 0.2 mmφ,
This operation was repeated four times on each side. As a result, in the three-layer sheet, the PET microfibers and the extra-twisted and false-twisted processed yarns of the microfibers and the fabric were sufficiently intertwined in three dimensions. Next, the surface of the entangled sheet was fluffed with a belt sander equipped with 240 mesh emery paper, and the substrate was impregnated with a 5% aqueous solution of polyvinyl alcohol (PVA), squeezed at a squeezing rate of 300%, and dried. The amount of PVA attached is based on the base fiber.
15% by weight (All adhesion percentages below are by weight.)
It was hot. After coating the fluffed surface layer with a thin layer of a concentrated solution of carboxymethyl cellulose (CMC) using a doctor knife and drying it, it was impregnated with a 1.5% DMF solution of polyether-based polyurethane, squeezed with a mangle, and soaked in water at room temperature. The mixture was allowed to coagulate for 10 minutes and dried. Thereafter, all the PVA fibers, PVA, and CMC in the base sheet were extracted and dried in hot water at 90°C for 30 minutes. Finally, the sheet-like material obtained in this way is
After dyeing with Sumikaron Rubine SE-2BL 5% owf, reduction washing with 25 g of Tecrolin and drying, the surface was lightly styled with a nylon brush. The obtained artificial leather has a suede-like surface with an extremely elegant writing effect.
The texture was also excellent with firmness and flexibility. Furthermore, as shown below, the clothing properties were excellent in terms of seam and tear strength, as well as excellent sewing properties. The women's coats cut and sewn using this material were well-tailored with an extremely elegant feel, and were free from fraying at the edges. Seam strength (warp direction): 40Kg/inch Tear strength (warp direction): 2.0Kg Flexibility: 47mm Elongation (1Kg/cm constant load): warp 8%, weft 13% fraying resistance: good Sewability: good ( Stretchability: 0 Seam puckering: 0) Example 2 PET 75 denier/36 filament 3000 times false twisted yarn (twisted S twist, untwisted Z twist) was added in the Z direction as shown in Table 2. After additional twisting, the yarn density was 75 threads/inch for both warp and warp threads, making it into a plain weave. 90% of this gray fabric
The fibers were subjected to shrinkage treatment in hot water at 180°C for 40 minutes, elongated to a warp/warp yarn density of 90 threads/inch, and then subjected to tension heat treatment in a pin tenter at 180°C. The elongation of the obtained fabrics was as shown in Table 2. These woven fabrics were processed in the same manner as in Example 1 to obtain suede-like artificial leather. These had a graceful writing effect on the surface, had firm flexibility, and had extremely excellent clothing properties, fraying resistance, and sewing properties as shown in Table 2. . For comparison, the number of additional twists (200 times/
Artificial leather was obtained in the same manner using false-twisted yarns having a diameter of 1.5 ft (1.2 m) and woven fabrics using straight yarns that were not subjected to false-twisting, but the fraying properties were poor.

[Table] All physical property values in the table are average values over time.
Example 3 The heat-set fabric of Example 1 was placed on a mixed sheet with a basis weight of 120 g/m ² consisting of 0.1 denier, 5 mm cut, 90 parts of ultrafine PET fiber, 1D, 5 mm cut, and 30 parts of PVA staple fiber, and then A 3-layer sheet was formed by placing a web of PET with an average fineness of 0.01 denier and an accumulated weight of 80 g/m ² on top, which was obtained by a melt-blowing method. Artificial leather was made from this sheet in the same manner as in Example 1. The obtained leather is melt-blown
Because the surface is made of PET fiber, it has a nubuck-like surface with extremely dense naps.
It was a high-quality leather with great flexibility. This leather had excellent seam and tear strength, as well as excellent fraying resistance and seamability. Example 4 False-twisted nylon 6 yarn (70 denier/24 filaments) was woven into a plain woven fabric with a density of 65 yarns/inch in warp and 70 yarns/inch in weft. This fabric is heated to 80℃
The material was shrink treated with hot water and heat set using a pin tenter, giving it an elongation of 17% in the warp. On the other hand, nylon 6 of 0.15 denier was obtained by the direct spinning method, and short fibers of 90 mm were cut into 3 mm pieces.
A sheet with a basis weight of 80 g/m ² was made by mixing 10 parts of PVA staple fibers of 1 d and 3 mm in the same part and using a paper-making method. The previously heat-set woven fabric was sandwiched between these two sheets, and the leather was processed in the same manner as in Example 1, dyed with an acid dye, and then straightened. This leather had a surface with a graceful writing effect, was excellent in flexibility, had excellent seam and tear strength, and was excellent in both fraying and sewing properties.

[Brief explanation of the drawing]

The drawing shows the shape of a sample when evaluating the fraying property of the present invention.

Claims (1)

[Scope of Claims] 1. Artificial leather comprising an elastic polymer contained between the structures of an intertwined body in which ultrafine fibers of 0.5 denier or less cover at least one side of the fabric and are intertwined with the fabric. The fibers are made of multifilament false-twisted yarn with a single yarn fineness of 3 denier or less, and the false-twisted yarn is twisted at a rate of 0 to 199 twists per meter, with a total denier of 50 to 150.
denier, and the thread density of the fabric is 60 to 250.
Artificial leather characterized by its thickness per inch. 2. The artificial leather according to claim 1, wherein the woven fabric is a plain woven fabric. 3 Toughness (T _S ×√) of false twisted yarn is 1250
Claim 1 characterized in that:
Artificial leather as described. 4. The artificial leather according to claim 1, wherein the elongation of the sheet material under a load of 1 kg/cm is 3 to 20% in the warp direction and 5 to 40% in the weft direction. 5. The artificial leather according to claim 1, wherein fluff of ultrafine fibers is formed on the surface of the sheet-like product.