JP2019112744A - Artificial leather, and method of producing the same - Google Patents

Abstract

To provide an artificial leather not only having a surface appearance expressing a fine structure, and high class feeling but also excellent in mechanical properties, and morphological stability in an artificial leather obtained by applying a polymer elastomer as a binder to a nonwoven fabric obtained by three-dimensionally entangling ultra fine fibers and a textile.SOLUTION: The artificial leather is produced by applying a polymer elastomer as a binder to a fiber-entangled body obtained by laminating and unifying a nonwoven fabric composed of ultrafine fibers having an average single fiber diameter of 0.3 μm or greater and 7.0 μm or less and a textile. At least one surface thereof has piloerections having a piloerection length of 200 μm or greater and 600 μm or less. A high density artificial leather is obtained by largely heat-shrinking after applying the polymer elastomer using a high-shrinkage polymer to the textile. A higher density artificial leather is obtained by press-processing if desired. Thus obtained is an artificial leather having a density of 0.50-0.85 g/cmby applying a polymer elastomer to a nonwoven fabric obtained by three-dimensionally entangling ultra fine fibers and a textile.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an artificial leather not only having a fine and high-quality surface appearance but also having excellent mechanical properties and form stability, and a method for producing the same.

  Conventionally, artificial leather is generally manufactured by applying a polymer elastic body to a non-woven fabric consisting of ultrafine fibers in order to obtain flexibility and mechanical performance similar to natural leather.

  On the other hand, "cordovan" which has a unique feeling of hard material and high hardness among natural leathers is leather which can be obtained from the buttocks of horses with high rare value, and has an extremely high density structure. It has excellent durability while having.

  As means for increasing the density of artificial leather, a method of shrinking in a process using a heat-shrinkable polymer, a method of compressing a sheet in the thickness direction by a heat press, and the like have been proposed.

  For example, a method of obtaining a high-density artificial leather by proposing a heat shrinkable treatment by integrating a non-woven fabric made of a heat-shrinkable polymer and a heat-shrinkable woven or knitted fabric has been proposed (see Patent Document 1). However, in this proposal, since the timing of contraction is before application of the polymer elastic body, the amount of application of the polymer elastic body decreases, so that the feel and touch characteristic of the leather are impaired, and paper-like There is a problem of becoming Further, in this proposal, since the manufacturing method is the papermaking method, the napped hair length of the surface is shortened due to the extremely short fiber length, and only nubuck-like artificial leather having a plain appearance can be obtained.

  There is also proposed a method of obtaining a high density suede-like artificial leather by heat-pressing a non-woven fabric made of a heat-shrinkable polymer (see Patent Document 2). However, in this proposal, since it is a structure which consists of a nonwoven fabric and a polymeric elastic body, and there is no reinforcement cloth, such as textiles, it has a subject that it is inferior in terms of durability by repeated use and form stability.

  From these facts, it is the present situation that the means necessary for achieving high-density artificial leather having excellent sense of volume (three-dimensional effect) and durability derived from napping length are not yet found. .

Unexamined-Japanese-Patent No. 2004-232126 JP, 2012-211414, A

  Therefore, the object of the present invention is to provide an artificial leather in which a high molecular weight elastic body is added as a binder to a non-woven fabric in which ultrafine fibers and a fabric are three-dimensionally entangled, in addition to having a fine surface appearance and a high-quality surface appearance. It is an object of the present invention to provide an artificial leather excellent in mechanical properties and shape stability.

  As a result of intensive investigations, the present inventors integrate a microfiber non-woven fabric and a high-shrinkage fabric, give a high-polymer elastic body, and then make a large contraction to obtain a high-quality surface quality. We found a way to obtain high density and durable artificial leather. Furthermore, it is also possible to obtain a higher density artificial leather by using a heat press in combination.

The artificial leather of the present invention is an artificial leather in which a polymer elastic body is applied to a fiber entangled body in which ultrafine fibers having an average single fiber diameter of 0.3 μm or more and 7.0 μm or less and a woven fabric are three-dimensionally entangled. It is an artificial leather characterized by having a raised hair having a length of 200 μm to 600 μm on one side and having a density of 0.50 to 0.85 g / cm ³ .

  According to a preferred embodiment of the artificial leather of the present invention, the yarn constituting the woven fabric is a twisted yarn having a twist number of 1000 T / m to 3500 T / m.

  According to a preferred embodiment of the artificial leather of the present invention, the thread-like component constituting the woven fabric is a polyester, and the copolymerizable component capable of imparting high shrinkage characteristics to the polyester is 2 mol% or more. It is contained in the ratio of mol% or less.

  According to a preferred embodiment of the artificial leather of the present invention, the copolymerization component of the fibers constituting the woven fabric is isophthalic acid or bisphenol A.

  In the method of producing an artificial leather according to the present invention, a polymer elastic body is added as a binder to a fiber entangled body in which a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.3 μm or more and 7.0 μm or less is integrally laminated. It is an artificial leather formed, It controls so that area retention at the time of dyeing may be 50% or more and 75% or less, and is a manufacturing method of the above-mentioned artificial leather characterized by the above-mentioned.

  In the method of producing an artificial leather according to the present invention, a polymer elastic body is added as a binder to a fiber entangled body in which a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.3 μm or more and 7.0 μm or less is integrally laminated. It is an artificial leather formed, It is a manufacturing method of the said artificial leather characterized by performing a press process after dyeing | staining.

  According to the present invention, since it has a high density relative to conventional artificial leather, it has not only a compact and voluminous surface appearance close to that of natural cordovan leather, but it is also a fabric that is a reinforcing cloth It is possible to obtain a high-class artificial leather having excellent mechanical properties and form stability in that it is inserted.

FIG. 1 is a drawing substitute photograph showing a cross section of the artificial leather of the present invention.

  The non-woven fabric layer constituting the artificial leather is a structure in which short fibers are entangled in three dimensions and there is no continuity of the fibers, so that the contraction stress at the time of heat treatment is dispersed. Since the strips are continuously arranged in two dimensions in the longitudinal direction and the width direction, the shrinkage stress of the woven fabric is easily transmitted to the non-woven fabric layer.

  As a result of intensive investigations, the present inventors integrate a non-woven fabric made of ultrafine fibers and a highly shrinkable woven fabric, give a polymer elastic body which is a binder of the ultrafine fibers, and then make a large shrinkage. We found a means to obtain high-density and durable artificial leather while having a certain surface quality.

  The details will be described below.

The artificial leather of the present invention is an artificial leather in which a polymer elastic body is applied to a fiber entangled body in which ultrafine fibers having an average single fiber diameter of 0.3 μm or more and 7.0 μm or less and a woven fabric are three-dimensionally entangled. It is an artificial leather having a raised hair having a length of 200 μm to 600 μm on one side and having a density of 0.50 to 0.85 g / cm ³ .

The fabric weight of the fabric used in the present invention is preferably ²⁰ to 200 g / m ² , and most preferably a fabric with a fabric weight of 30 to 150 g / m ² .

When the fabric weight of the woven fabric is less than 20 g / m ² , the form of the woven fabric becomes extremely loose, and when the woven fabric is sandwiched between the nonwoven fabric and the middle layer of the nonwoven fabric, wrinkles are generated when the fabric is superposed on the surface of the nonwoven fabric, It tends to be difficult to spread evenly.

In addition, when the fabric weight of the woven fabric exceeds 200 g / m ² , the woven fabric becomes dense, the penetration of the non-woven monofilament into the woven fabric is insufficient, and the entanglement between the non-woven fabric and the woven fabric does not proceed. They tend to be generally difficult to make.

  As the woven fabric used in the present invention, a woven fabric of plain texture is preferably used as the basic tissue. Although twill or satin woven fabric can be used as the woven fabric structure, the anisotropic behavior of the structure makes the behavior different from the external force in the diagonal direction, and in handling, when the density of the woven fabric is low, misalignment easily occurs Therefore, it is a preferred embodiment to use a plain weave fabric. In addition, as a means of densifying the object of the present invention, it is possible to effectively transmit the strong heat-shrinkage force of the woven fabric to the integrated non-woven fabric by making it a woven fabric of flat structure using continuous long fibers. Can.

  As fibers constituting the woven fabric used in the present invention, synthetic fibers such as polyester fibers, polyamide fibers and aramid fibers can be used, but it is possible to select fibers composed of a polymer having high shrinkage. preferable. For example, when the polyester multifilament contains the copolymer component which is the third component, the boiling water shrinkage of the raw yarn can be improved, and the shrinkage can be increased. If the boiling water shrinkage rate is high, it is possible to densify the fabric during the dyeing process. Furthermore, the integrated non-woven fabric also shrinks in accordance with the woven fabric, which makes it possible to densify the non-woven fabric.

  As the above-mentioned copolymerization component, isophthalic acid and bisphenol A are preferably used from the viewpoint of expression of spinnability and high shrinkage characteristics. Further, the content of the copolymerization component is preferably 2 mol% or more in order to sufficiently impart high shrinkage characteristics. However, if the copolymer component is contained in excess of 20 mol%, yarn breakage frequently occurs during spinning, so the content of the copolymer component is preferably 20 mol% or less. Moreover, as for the kind of these fibers, it is a preferable aspect to use the raw material of the same kind as the fiber which comprises a nonwoven fabric from the point of dye fastness.

  Types of fiber yarns used for the fabric used in the present invention include filament yarns, spun yarns, innovative spun yarns, and composite yarns of filament yarns and spun yarns. It is preferable to use a filament yarn because a spun yarn has a structure in which a large number of fluffs exist on the surface and when the non-woven fabric and the woven fabric are entangled, the fluffs fall off and become exposed on the surface. Filament yarns are roughly classified into monofilaments composed of one single fiber and multifilaments composed of a plurality of filaments, but in the fabric used in the present invention, multifilaments are preferably used. In the case of monofilaments, the rigidity of the fibers is too high, which may impair the texture of the artificial leather.

  The single-fiber fineness of the multifilament yarn constituting the woven fabric used in the present invention is less likely to differ in dyeing as the single-fiber fineness of the fibers constituting the non-woven fabric and is less likely to impair the appearance even when exposed on the surface of artificial leather Therefore, it is preferably 0.0001 dtex or more and 3.0 dtex or less, and more preferably 1.5 dtex or less.

  The single fiber fineness for the filament yarn described above applies to spun yarns other than filament yarns and innovative yarns.

  Moreover, it is preferable that the total fineness of a multifilament yarn is 30 dtex-170 dtex. When a multifilament yarn having a total fineness of less than 30 dtex is used, the fiber yarns constituting the fabric are easily caught on the barbs of the needles. In general, the lower limit of the value of the throat depth of the barb is practical up to 10 μm, but in order to promote fiber entanglement and integration with the fabric, the throat depth range of the needle is preferably 30 μm to 100 μm. Preferably, those in the range of 50 μm to 80 μm are used. Therefore, the total fineness of the multifilament yarn is preferably 30 dtex or more.

  In addition, when the total fineness of the multifilament yarn exceeds 170 dtex, the fabric weight of the woven fabric becomes large, and hence the fabric weight of the artificial leather becomes large. In addition, the rigidity of the fabric is increased, and as a result, it may not be possible to obtain sufficient flexibility sufficient as an artificial leather.

  The total fineness of the fiber yarns constituting the woven fabric used in the present invention is more preferably 50 dtex to 150 dtex, for reasons such as rigidity and fabric weight.

  The form of the multifilament yarn is roughly divided into false twisted yarn and raw yarn without crimp, but it is acceptable to use either in the present invention. However, when a false-twisted yarn is used, crimped yarn causes swelling of the yarn, so the needle tends to be easily damaged. Therefore, in the present invention, it is a preferred embodiment to use raw silk which does not have a crimp.

  The twisting number of the yarn constituting the woven fabric used in the present invention is preferably 1000 T / m or more and 3500 T / m or less, more preferably 1500 T / m or more and 3000 T / m or less. When the number of twists is smaller than 1000 T / m, the number of single fiber breakage of microfibers by needle punching is large, the thermal contraction force is largely reduced, and the physical properties of the product are deteriorated and the single fiber is frequently exposed to the product surface. On the other hand, when the twist number is larger than 3500 T / m, the shrinkage of the fabric is suppressed, and in addition to the fact that the desired high density artificial leather can not be obtained, the rigidity of the fabric becomes high and the texture of the artificial leather is hardened. Do.

  The non-woven fabric used in the present invention is a non-woven fabric in which short fibers such as natural fibers, regenerated fibers and synthetic fibers are laminated through cards, cloth wrappers and random webers etc., long fibers such as spunbonds and meltblowns are laminated. Non-woven fabric. Furthermore, non-woven fabrics in which these laminated fiber layers are preliminarily subjected to preliminary entanglement by air flow, liquid flow, needle punch and the like are also used.

  Moreover, it is desirable that the fibers constituting the non-woven fabric used in the present invention be microfibers or fibers capable of being microfibrillated.

  Ultrafine fibers or fibers which can be ultrathinned include polyester polymers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid and polyester elastomer, polyamide polymers such as nylon 6, nylon 66 and polyamide elastomer, Fibers comprising a polymer having a fiber-forming ability such as a polyurethane-based polymer, a polyolefin-based polymer, and an acrylonitrile-based polymer are preferable. Among these, fibers made of polyethylene terephthalate, polybutylene terephthalate, nylon 6 and nylon 66 are particularly preferably used from the viewpoint of feeling and practical performance of the processed product.

  In addition, in the case of fibers such as islands-in-the-sea fibers that are ultrafine-fibered by removing or exfoliating a part of the polymers constituting the composite fiber, the island component is configured as a component to be removed (sea component). Copolymer polyester comprising polyethylene, polypropylene, polystyrene, copolymer polystyrene, polyvinyl alcohol, sodium sulfoisophthalic acid or polyethylene glycol as a copolymer component from the viewpoint of having higher solubility and degradability than polymer. One or two species of polylactic acid and copolyamide can be used.

  As a solvent for dissolving the sea component, when the sea component is polyethylene, polypropylene, polystyrene and copolymer polystyrene, an organic solvent such as toluene or trichloroethylene is used, and when the sea component is copolymer polyester or polylactic acid, An alkaline aqueous solution such as sodium hydroxide can be used, and in the case of a hot water-soluble polyester or polyvinyl alcohol, hot water is used, and the sea-island composite fiber is immersed in a solvent or a solution to perform drainage. , Sea component can be removed. In particular, polystyrene, copolymer polystyrene, polyester, copolymer polyester and polylactic acid are preferably used as a sea component from the viewpoint of densification of surface fibers by high entanglement of fibers when needle punching is performed.

  It is important that the average single fiber diameter of the ultrafine fibers constituting the nonwoven fabric used in the present invention is 0.3 μm or more and 7.0 μm or less. The average single fiber diameter is preferably 0.5 μm or more and 6.0 μm or less in order to enhance the performance as an artificial leather, that is, flexibility, touch, appearance quality and strength characteristics, etc., but coloration and touch are further improved It is a particularly preferred embodiment that the thickness is 1.0 μm or more and 5.5 μm or less.

  Such microfibers are obtained from the following microfiber-generating fibers. That is, as the ultrafine fiber generation type fiber, for example, a polymer array fiber composed of two or more types of polymers (described in JP-B-44-18369) and two types of polymers having small mutual compatibility are used. An easily splittable conjugate fiber (described in JP-B-53-37456) and the like which are adjacent to each other can be mentioned. However, the present invention is not limited to these, and the fiber of the developmental form is applicable based on the technical thought.

The density of the non-woven fabric obtained by needle punching is preferably 0.100 g / cm ³ or more in order to obtain an elegant appearance and a good touch of the artificial leather, and in order to prevent needle breakage in needle punching. It is preferable that it is 400 g / cm < ³ > or less. Density of the nonwoven fabric is more preferably at most 0.150 g / cm ³ or more 0.350 g / cm ^3.

When laminating the woven fabric to the non-woven fabric in the needle punching process, the relationship between the diameter of the fiber yarn forming the woven fabric and the throat depth of the needle used for the needle punching is used as a method of minimizing damage to the woven fabric from the needle. A manufacturing method has been proposed which clearly indicates the reduction in strength (Japanese Patent Publication No. 7-13344). In order to suppress the damage to the fabric, it is preferable that the barb size of the needle and the diameter of the fiber yarns constituting the fabric satisfy the following equation as known.
・ D 2 2J
(Here, D represents the diameter of the fiber yarn constituting the fabric, and J represents the throat depth of the needle barb.)
However, if the throat depth value is too small, the barb's efficiency of gripping the fibers constituting the non-woven fabric decreases, and it becomes difficult to sufficiently increase the entanglement between the non-woven fabric and between the non-woven fabric and the woven fabric. It is necessary to select the appropriate barb size in consideration of the fiber diameter.

  For this reason, it is preferable that the throat depth of the barbs satisfy the above-mentioned relational expression, but when the needle is used continuously, the shape may change due to wear and the relational expression may not be satisfied. In order to avoid that, it is preferable to apply a film having wear resistance to the needle. Specifically, it is possible to use a punching needle which is preferably coated with an abrasion resistant coating at least in the portion from the needle tip to the furthest barb. Specifically, a coating made of a material having excellent wear resistance and low friction characteristics such as hard chromium and DLC (diamond-like carbon) is preferable as the coating for covering the tip of the needle, and in particular, it is common and relatively low. A hard chromium coating, which is cost, is preferably used.

  Also, by applying needle punching, the non-woven fabric shrinks in the direction (width direction) perpendicular to the sheet traveling direction, and the laminated fabric also shrinks following it, so the fiber yarns of the fabric parallel to the width direction (It corresponds to the weft of the fabric.) Will be slackened. Loose fiber yarn is easy to be brought in by the barb of the needle and also susceptible to damage. On the other hand, since the fiber yarns of the woven fabric (corresponding to the warps of the woven fabric) parallel to the traveling direction of the sheet are always in tension by the process tension, they are difficult to be brought into the inner layer of the non-woven fabric by the barbs of the needles. Therefore, it is preferable to restrict the direction of the barb to | 0 ° to 30 ° |, assuming that the perpendicular angle to the sheet advancing method is 0 °.

  In the entanglement of the non-woven fabric and the woven fabric, the woven fabric can be laminated on one side or both sides of the non-woven fabric, or the woven fabric can be sandwiched between a plurality of non-woven fabrics, and the fibers can be entangled by needle punching.

  As a method of laminating and integrating a nonwoven fabric and a woven fabric, the woven fabric is uniformly spread and laminated on one side of the nonwoven fabric, needle punching is performed from the nonwoven fabric side, and the fibers constituting the nonwoven fabric are extruded to the woven fabric side In general, needle punching is alternately performed from the woven side and the non-woven side until the target sheet density is obtained. When laminating the fabric on both sides of the non-woven fabric, after laminating the fabric on one side by the above method, the fabric is laminated on the non-woven side, and needle punching is performed from the opposite side (the side of the first laminated fabric). The method of integrating is common. In addition, regarding the method of sandwiching the woven fabric between a plurality of non-woven fabrics as well, a method is generally adopted in which the woven fabric and the non-woven fabric are integrated by the above method and then the non-woven fabric is laminated on the surface on the woven fabric side to perform needle punching. It is.

  There is no particular difference in the function due to the difference in the laminated structure, but the sheet in which the woven fabric is laminated on both sides of the non-woven fabric is advantageous in cost because two sheets can be obtained by slicing (splitting) in a later step. It is.

At this time, it is a desirable aspect that the preliminary entanglement is given to the non-woven fabric by any means as described above, in order to further prevent the occurrence of wrinkles when the non-woven fabric and the fabric are disjointed and integrated by needle punching. . In that case, by needle punching, in the case of adopting a method of providing pre-preliminary entanglement, the punching density is effective be carried out at 20 lines / cm ² or more, preferably 100 / cm ² or more It is preferable to provide preliminary entanglement at a punch density of at least 200, and more preferably, to provide preliminary entanglement at a punch density of 300 / cm ^{2 to} 1300 / cm ² .

When the preliminary entanglement is less than the above-mentioned 20 punches / cm ² , the width of the non-woven fabric leaves room for narrowing at the time of entanglement with the fabric and subsequent needle punches, As a result, wrinkles occur in the woven fabric, and a smooth fiber sheet can not be obtained. In addition, when the punch density of the preliminary entanglement exceeds 1300 / cm ² , the entanglement of the non-woven fabric advances too much, and there is less room for movement to sufficiently form entanglement with the fibers constituting the fabric. This is because it is disadvantageous to realize a non-woven integral structure in which the non-woven fabric and the woven fabric are strongly entangled.

When the woven fabric and the non-woven fabric are intertwined and integrated, the range of the punch density is preferably 300 / cm ^{2 to} 6000 / cm ^2, and more preferably 1000 / cm ^{2 to} 3000. It is a book / cm ² .

  Next, the ultrafine fiber-forming fibers in the resulting fibrous sheet are treated with at least one component of the fiber-constituting polymer (preferably a sea-constituting polymer) with a solubilizer or decomposing agent, or mechanically Alternatively, the substrate is denatured to ultrafine fibers or ultrafine fiber bundles by chemical treatment to obtain an artificial leather substrate (nonwoven fabric comprising ultrafine fibers).

  At this time, the polymer elastic body fluid is applied before or after the modification treatment of the microfiber generation type fiber, but both of these sequences are possible. When modifying the polymer elastic body fluid before application, the polymer elastic body fluid is applied after applying a dissolvable removable temporary filler such as polyvinyl alcohol so that the ultrafine fibers and the polymer elastic body do not adhere to each other. Then, removing the temporary filler thereafter is a preferred embodiment in order to obtain the flexibility of the fibrous sheet.

  Polyester is most preferable as the thread-like polymer constituting the fabric used in the present invention. It is a preferred embodiment that the above polyester contains a copolymer component capable of imparting high shrinkage properties. When the content of the copolymerization component is less than 2 mol%, the shrinkage effect of the fabric can not be obtained, and when it is more than 20 mol%, the yarn breakage of spinning frequently occurs and the operability is significantly reduced and it is difficult to obtain thread Become. The preferable content of the copolymerization component is 2 mol% or more and 20 mol% or less, more preferably 5 mol% or more and 15 mol% or less. As a copolymerization component of the fiber which comprises said textiles, isophthalic acid or bisphenol A is used preferably.

  As the polymer elastic body used in the present invention, polyurethane, polyurea, polyurethane / polyurea elastomer, polyacrylic acid, acrylonitrile / butadiene elastomer and styrene / butadiene elastomer can be used, but from the viewpoint of flexibility and cushioning property Polyurethane is preferably used.

  In addition, the polymer elastic body can contain an elastomer resin such as polyester, polyamide and polyolefin, an acrylic resin, and an ethylene-vinyl acetate resin. The polymer elastic body may be either dissolved in an organic solvent or dispersed in water.

  With regard to a suitable use ratio of the polymer elastic body, the weight of the polymer elastic body relative to the mass of the fiber entangled body is preferably 10% by mass to 200% by mass, and more preferably 20% by mass to 180% by mass is there. When the mass of the elastic polymer is less than 10% by mass, the fibers are largely detached from the artificial leather, and when the mass of the elastic polymer is more than 200% by mass, the texture of the artificial leather tends to be hard.

In order to obtain a high density suede-like artificial leather, it is important that the artificial leather be greatly shrunk after application of the polymer elastic body. When the sheet density before the application of the polymer elastic body is high, the polymer elastic solution is difficult to be impregnated, and therefore, the amount to be applied can not be increased, resulting in an artificial leather having poor mechanical physical properties and shape stability. On the other hand, when the density of the non-woven fabric is too low, it is impossible to obtain the high-density artificial leather which is the object of the present invention. The density of the non-woven fabric before application of the polymer elastic body is 0.180 g / cm ³ or more, and preferably 0.400 g / cm ³ or less. The nonwoven fabric density is more preferably 0.200 g / cm 3 or more and 0.380 g / cm ³ or less.

  In addition, the polymer elastic body used in the present invention may, if necessary, be a pigment such as carbon black, a dye antioxidant, an antioxidant, an antioxidant, a light stabilizer, an antistatic agent, a dispersant, a softener, a coagulation regulator, Additives such as flame retardants, antibacterial agents and deodorants can be blended.

  The base material for artificial leather obtained above can be adjusted to a desired thickness by slicing, buffing or the like. It becomes suede-like artificial leather by dyeing the above-mentioned base material which raised the extra fine fiber bundle of the surface by buffing etc.

  The dyeing is preferably carried out by a high-temperature high-pressure dyeing machine in order to soften the texture of the artificial leather substrate sheet to be dyed using a disperse dye, a cationic dye and other reactive dyes. The dyeing temperature is preferably 80 ° C to 150 ° C, and more preferably 110 ° C or more. If necessary, finishing treatments such as softeners such as silicone, antistatic agents, water repellents, flame retardants and light stabilizers may be applied, and the finishing treatments may be after dyeing or in the same bath as dyeing.

  In the present invention, it is important to set the area retention of the sheet at the time of dyeing to 50% or more and 75% or less. If the area retention rate is less than 50%, the yield of the product is degraded and the practicability is low. On the other hand, when the area retention rate exceeds 75%, a sufficient density increase effect can not be obtained, and a target high-density product can not be obtained.

  The artificial leather of the present invention is characterized in that it has a surface feeling with a voluminous feeling (three-dimensional feeling) derived from napped hair length. The range of napped hair length is 200 μm or more and 600 μm or less, more preferably 250 or more and 550 μm or less. When the nap length is shorter than 200 μm, it becomes a nubuck-like flat surface, and a volume feeling can not be obtained. On the other hand, when the length of napped hair is longer than 600 μm, the ultrafine fibers are entangled and become hairballs, resulting in the deterioration of the quality. The preferred range of napped hair length is 200 μm to 600 μm, and more preferably 250 μm to 550 μm.

The artificial leather of the present invention is characterized by having a high density. The density range is 0.50 g / cm ³ or more and 0.85 g / cm ³ or less. When the density is lower than 0.50 g / cm ^{3, the} feeling is soft and a hard material feeling like cordon and high hardness can not be obtained. On the other hand, when the density is higher than 0.85 g / cm ³ , the texture is too hard and not suitable for practical use. The preferred range of density of the artificial leather of the present invention ^{is 0.50g / cm 3 ~0.85g / cm 3} , more preferably ^{0.52g / cm 3 ~0.83g / cm 3} .

  The artificial leather of the present invention can form a discontinuous resin layer on its napped surface. The method for forming the resin layer is not particularly limited as long as it can be applied discontinuously on the surface of the fiber entangled body to be artificial leather, but a screen method such as flat screen or rotary screen or gravure coating method etc. After coating, the resin layer is dried to form a resin layer, or a discontinuous resin film is formed on a support base fiber such as release paper, and then an adhesive is applied to the surface of the resin film to form a fiber structure The method of forming a resin layer, etc. is mentioned by bonding and bonding to the surface which becomes, and peeling a release paper.

  The resin layer preferably has a layer structure of two or more layers. Furthermore, it is a more preferable aspect that the said resin layer consists of a three-layer structure which consists of an adhesive layer, an intermediate | middle layer, and a surface layer. Here, the adhesive layer has an adhesive function of fiber entanglement and the resin layer of the intermediate layer and the surface layer. The intermediate layer serves as a base of the resin layer, and the surface layer plays a role in forming quality and touch. In order to make a resin layer into two layers or three layers, it can form by repeating said method 2 times or 3 times. Moreover, about the said method, the same method may be repeated and it can also be used combining two or more types.

  In the present invention, the artificial leather after dyeing can also be subjected to a pressing treatment for the purpose of further densifying. The temperature of the press treatment is preferably 100 ° C. or more for the purpose of achieving higher density. In addition, in order to suppress deterioration in color developability and fastness and deterioration of the polymer elastic body, the temperature is preferably 200 ° C. or less, more preferably 180 ° C. or less, and still more preferably 160 ° C. or less. It is.

  On the other hand, the compression rate can be appropriately adjusted in accordance with the density before compression and the target density. Moreover, the linear pressure at this time can be suitably adjusted, for example in the range of 5-6000 N / cm. Also, the processing speed can be appropriately adjusted, for example, in the range of 0.1 to 50 m / min.

  The artificial leather of the present invention not only has a fine and high-grade surface appearance but is also excellent in mechanical physical properties and form stability, from furniture, chairs and vehicle interior materials to clothing applications and industrial materials. It can be used widely and suitably.

  Next, the artificial leather of the present invention and the method for producing the same will be described in more detail by way of examples.

[Measuring method]
(1) Base weight (g / m ² ):
Three samples of 50 cm long and 50 cm wide are collected at random from a woven fabric, non-woven fabric or artificial leather, the mass of each sample is measured, and the average value of the obtained values is converted per unit area, The first place was rounded off below.

(2) Density (g / cm ³ ):
The thickness of each sample collected in the basis weight measurement was measured with a dial degree gauge (manufactured by Ozaki Mfg., Trade name "Pecock H"), and the density was calculated by dividing from the basis weight, and the fourth place after the decimal point was rounded off.

(3) Average single fiber diameter (μm) of ultrafine fibers:
Calculated by taking a scanning electron microscope (SEM) photograph of an artificial leather cross section, randomly selecting 100 circular or nearly circular elliptical fibers, measuring the diameter of single fibers, and calculating the average value of 100. did. When the ultrafine fiber of atypical cross section was adopted, the diameter of the circumscribed circle of the ultrafine fiber was regarded as a single fiber diameter, and the same calculation was made.

(4) Napped hair length (μm):
Ultrafine fibers on the surface of the artificial leather were raised with a brush, and then the cross section of the artificial leather was photographed at a magnification of 40 times using a scanning electron microscope (SEM). In the cross-sectional photograph shown in FIG. 1, at the middle point of the uppermost point and the lowest point of the boundary of the layer in which the ultrafine fiber bundle and the polymer elastic body are mixed (nonwoven fabric layer) and the napped layer where only the ultrafine fiber is present. A line L is drawn to mark points P1 to P10 on the line L at intervals of 200 μm. A perpendicular line is drawn from points P1 to P10 in the direction of the nap layer, respectively, to mark points Q1 to 10 intersecting the tip of the nap layer. The distance between the point P and Q1 was R1, and similarly, R10 was obtained to calculate the average value.

(5) Area retention rate at the time of dyeing of artificial leather:
The area of the artificial leather substrate sheet before and after the dyeing process was measured, and the dyed area retention rate (%) was calculated. In addition, the size of the measurement sample sheet is 30 cm square or more, 20 cm marking is performed in the vertical direction and the horizontal direction, and the area is obtained from the change in length before and after the dyeing process.

Example 1
<Raw cotton to fiber sheet substrate>
Using polyethylene terephthalate as the island component and polystyrene as the sea component, the mass component ratio of the island component and the sea component is 80/20, the number of islands is 16, the single fiber fineness of the composite fiber is 3.8 dtex, the fiber length A non-woven fabric was produced through the steps of carding and cross-wrapping using raw cotton of a sea-island type composite fiber of 51 mm in diameter and 14 crimps / inch in crimp number. Subsequently, needle punching of 300 pre-punches / cm ² was performed to prepare a nonwoven fabric (felt) with a basis weight of 500 g / m ² . On the other hand, polyester long fibers of 84 dtex (long diameter D1 = D2 = 0.125 mm) -72 filaments obtained by melt-spinning polyethylene terephthalate containing 8 mol% of isophthalic acid which is a copolymer component by a known method are twisted A woven fabric with a weave density of 95 × 76 / cm was produced at several 2000 T / m. The woven fabric is spread uniformly on the lower surface of the non-woven fabric under constant tension and laminated to form a fiber sheet, and a needle with a throat depth J = 60 μm and a needle blade section with an equilateral triangle cross the barb direction With needle board planted at a direction perpendicular to the direction 0 °, first perform needle punching of 300 threads / cm ² from the non-woven fabric side of the fiber sheet, and then perform needle punching of 300 threads / cm ² from the textile side At the same time, on the non-woven fabric side, a plain woven fabric of the same design as described above was uniformly spread and laminated while applying a constant tension.

Thereafter, needle punching of 2700 needles / cm ² in total was alternately performed from the upper surface side and the lower surface side to obtain a fiber entangled body having a basis weight of 700 g / m ² and an apparent density of 0.220 g / cm ³ .

<Artificial leather>
After pre-shrinking the above-mentioned fiber entangled body with hot water at a temperature of 96 ° C., it is impregnated with a 5% PVA (polyvinyl alcohol) aqueous solution and dried by hot air at a temperature of 110 ° C. for 10 minutes. The sheet | seat of 4 mass% of PVA mass with respect to mass was obtained. This sheet was immersed in trichloroethylene to dissolve and remove the sea component, to obtain a dewatered sheet (fiber entangled body) in which microfibers and a fabric are entangled. The dewatered sheet (fiber entangled body) composed of the non-woven fabric and the woven fabric of ultrafine fibers thus obtained is immersed in a solution of polyurethane adjusted to a solid concentration of 12% in DMF (dimethylformamide), and then DMF The polyurethane was coagulated in a 30% strength aqueous solution. Thereafter, the PVA and DMF are removed with hot water and dried with hot air at a temperature of 110 ° C. for 10 minutes to obtain the above-mentioned ultrafine fibers comprising an island component having a single fiber fineness of 0.21 dtex and a fiber diameter of 4.4 μm. And an artificial leather substrate sheet having a polyurethane mass of 27% by mass and a density of 0.410 g / cm ³ based on the total mass of the woven fabric described above.

The artificial leather substrate sheet thus obtained was semi-cut vertically in the thickness direction, and the semi-cut surface was ground with an endless sand paper with a sandpaper number 180 and a napped surface was formed. The artificial leather substrate sheet thus obtained is put into a jet flow dyeing machine, shrinking and dyeing are simultaneously carried out under the condition of a temperature of 120 ° C., and then drying is carried out with a drier to obtain a dyed area retention rate. Got 62% of artificial leather. The artificial leather thus obtained has a dyed area retention rate of 62% and a nap length of 400 μm, and although some thickness has been recovered by dyeing, its density is as high as 0.615 g / cm ³ and it is dense and rigid High artificial leather was obtained. The results are shown in Tables 1 and 2.

Example 2
The artificial leather was obtained by processing under the same conditions as in Example 1 except that the content of isophthalic acid, which is a copolymerization component of fibers constituting the woven fabric, was changed to 2 mol% in Example 1 described above. The artificial leather thus obtained had a dyed area retention of 72%, a napped length of 400 μm, and a density of 0.521 g / cm ³ . The results are shown in Tables 1 and 2.

[Example 3]
The artificial leather was obtained by processing under the same conditions as in Example 1 except that the content of isophthalic acid, which is a copolymerization component of the fibers constituting the woven fabric, was changed to 20 mol% in Example 1 above. The artificial leather thus obtained had a dyed area retention of 57%, a napped length of 400 μm, and a density of 0.683 g / cm ³ . The results are shown in Tables 1 and 2.

Example 4
Processed under the same conditions as in Example 1 except that the content of isophthalic acid which is a copolymerization component of the fibers constituting the woven fabric was changed to 18 mol% and the number of twists 1500 T / m in Example 1 above. I got an artificial leather. The artificial leather thus obtained had a dyed area retention of 53%, a napped length of 400 μm, and a density of 0.710 g / cm ³ . The results are shown in Tables 1 and 2.

[Example 5]
The artificial leather obtained in Example 4 above was pressed at a speed of 0.5 m / min with a compression ratio of 0.5 using a steel calender heated to 150 ° C. The artificial leather thus obtained had a napping length of 400 μm and a density of 0.780 g / cm ³ . The results are shown in Tables 1 and 2.

[Example 6]
Processing under the same conditions as Example 1 except that the mass component ratio of polyethylene terephthalate as island component and polystyrene as sea component is 55/45, the number of islands is 36, and the single fiber fineness of composite fiber is 2.8 dtex. I got an artificial leather. The artificial leather thus obtained has a dyed area retention of 53%, a dyed density of 0.735 g / cm ³ (density before application of a polymer elastic body of 0.425 g / cm ³ ), and a nap length of It was 350 μm. Furthermore, the heat press treatment was performed under the same conditions as in Example 5 to obtain a density of 0.822 g / cm ³ . The results are shown in Tables 1 and 2.

Comparative Example 1
The artificial leather was obtained by processing under the same conditions as in Example 1 except that the copolymer component was not added to the fibers constituting the woven fabric in the above-mentioned Example 1. The artificial leather obtained in this way has a 85% area retention of the dyed area and a length of napped hair because shrinkage in dyeing is reduced by not applying the copolymer component to the polyester thread forming the fabric. but 400 [mu] m, density became inferior 0.431 g / cm ^3, and the denseness. The sheet was further pressed under the same conditions as in Example 5, but the density was 0.480 g / cm ^{3 and a} sufficient density was not obtained. The results are shown in Tables 1 and 2.

Comparative Example 2
The artificial leather was obtained by processing under the same conditions as in Example 1 except that in the above-mentioned Example 1, the number of twists of the yarn constituting the woven fabric was set to 4000 T / m. The artificial leather thus obtained has a high twist number of the fabric and a reduced shrinkage in dyeing, so the dye area retention is 90%, the nap length is 400 μm, and the density is 0.417 g / cm ^3. And the density was inferior. The results are shown in Tables 1 and 2.

Comparative Example 3
In Example 1 above, an artificial leather was obtained by processing under the same conditions as Example 1 except that the number of twists of yarn constituting the woven fabric was changed to 800 T / m, but since the number of twists is small, needle punch At the same time, the fabric was heavily damaged and the shrinkage and mechanical properties were significantly reduced. The artificial leather obtained in this manner has an area retention rate of 95%, a nap length of 400 μm, and a density of 0.393 g / cm ³ due to small shrinkage in dyeing, resulting in poor compactness. . The results are shown in Tables 1 and 2.

Comparative Example 4
Mass component ratio consisting of polyethylene terephthalate as island component and polystyrene as sea component is 80/20, number of islands is 16, composite fiber single fiber fineness is 3.8 dtex, fiber length is 51 mm, crimp number is 14 peaks / inch The raw cotton of the sea-island type composite fiber was used to make a non-woven fabric through the steps of carding and cross-wrapping. Subsequently, needle punching of 300 pre-punches / cm ² was performed to prepare a nonwoven fabric (felt) having a basis weight of 600 g / m ² . Thereafter, needle punching of 2700 needles / cm ² in total was alternately performed from the upper surface side and the lower surface side to obtain a fiber entangled body having a basis weight of 650 g / m ² and an apparent density of 0.215 g / cm ³ . The fiber entangled body is pre-shrunk with hot water at a temperature of 96 ° C., then impregnated with a 12% aqueous solution of PVA (polyvinyl alcohol) and dried with hot air at a temperature of 110 ° C. for 10 minutes, the mass of the fiber entangled body The sheet | seat of 25 mass% of PVA mass with respect to is obtained. This sheet was immersed in trichloroethylene to dissolve and remove the sea component, to obtain a dewatered sheet (fiber entangled body) in which microfibers and a fabric are entangled. The dewatered sheet (fiber entangled body) composed of the non-woven fabric and the woven fabric of ultrafine fibers obtained in this manner is immersed in a DMF (dimethylformamide) solution of polyurethane adjusted to a solid concentration of 12%, and then the DMF concentration The polyurethane was coagulated in a 30% aqueous solution. Thereafter, the PVA and DMF are removed with hot water and dried with hot air at a temperature of 110 ° C. for 10 minutes, whereby the mass of polyurethane relative to the total mass of the microfibers and the fabric consisting of island components having a single fiber fineness of 0.21 dtex An artificial leather substrate sheet having 34% by mass and a density of 0.401 g / cm ³ was obtained.

The artificial leather substrate sheet thus obtained was semi-cut vertically in the thickness direction, and the semi-cut surface was ground with an endless sand paper with a sandpaper number 180 and a napped surface was formed. The artificial leather substrate sheet thus obtained was put into a jet flow dyeing machine, and shrinkage treatment and dyeing were simultaneously carried out under conditions of a temperature of 120 ° C. and then drying was carried out with a dryer. The area retention rate became 96% because it was elongated in the longitudinal direction. The artificial leather thus obtained had a dyed area retention rate of 95%, a nap length of 400 μm, a density of 0.384 g / cm ³ and was inferior in compactness. The results are shown in Tables 1 and 2.

Comparative Example 5
A polyethylene terephthalate ultrafine fiber with a fiber diameter of 3 μm was produced by the direct spinning method, and cut into a length of 5 mm to obtain a single fiber. Next, this single fiber was uniformly dispersed in water, a PVA aqueous solution having a degree of saponification of 88% was added, and a slurry for sheet-making was prepared so that the solid content was 15% by mass with respect to the single fiber content.

This slurry is formed into a sheet, a sheet-formed non-woven sheet having a basis weight of 106 g / m ² is produced, the above-mentioned sheet-formed non-woven fabric is laminated on both sides of the same woven fabric as in Example 1, and entangled and integrated three-dimensionally by high-speed water jet. I did. Here, the high-speed water flow was injected from a straight flow jet nozzle with a hole diameter of 0.1 mm at a pressure of 20 kg / cm ² , and was made to collide with the papermaking nonwoven fabric at a position of 20 mm from the nozzle. This operation was performed from the front and back sides of the paper-made nonwoven fabric. The basis weight of the obtained paper-made nonwoven fabric was 160 g / m ² .

The fiber entangled body consisting of the non-woven paper and fabric thus obtained was immersed in a DMF solution of polyurethane adjusted to a solid concentration of 12%, and then the polyurethane was coagulated in an aqueous solution of DMF concentration of 30%. . Thereafter, by drying for 10 minutes with hot air at a temperature of 110 ° C., an artificial leather base sheet having a polyurethane mass of 27% by mass and a density of 0.430 g / cm ³ with respect to the total mass of the microfibers and the fabric is obtained. The

One side of the artificial leather substrate sheet thus obtained was ground with an endless sand paper having a sandpaper count number 180 to form a napped surface. The artificial leather substrate sheet thus obtained is put into a jet flow dyeing machine, shrinking and dyeing are simultaneously carried out under the condition of a temperature of 120 ° C., and then drying is carried out with a drier to obtain a dyed area retention rate. Got 63% of artificial leather. The artificial leather thus obtained has a high density artificial leather with a dyed area retention of 63% and a density of 0.630 g / cm ³ , but has a short nap of 150 μm and a plain surface quality. As a result, I lost a sense of volume. The results are shown in Tables 1 and 2.

  In this manner, the ultrafine non-woven fabric and the highly shrinkable fabric are integrated, and after being imparted with a polymer elastic body and greatly shrunk, high density and high durability are obtained while having a high-grade surface quality. Artificial leather can be obtained. Furthermore, it is also possible to obtain a higher density artificial leather by using a heat press in combination. As a result, it not only has a dense and voluminous surface appearance close to that of natural cordovan leather, but also has excellent mechanical properties and form stability in that a fabric that is a reinforcing cloth is inserted. It is possible to obtain a high-class artificial leather.

P1 to P10: Boundary point between napped layer and nonwoven fabric layer at each measurement point Q1 to Q10: Tip end of napped hair at each measurement point L: boundary line between napped layer and nonwoven layer

Claims (9)

An artificial leather in which a polymer elastic body is applied to a fiber entangled body in which ultrafine fibers having an average single fiber diameter of 0.3 μm or more and 7.0 μm or less and a woven fabric are three-dimensionally entangled. An artificial leather characterized by having a nap of 200 to 600 μm and having a density of 0.50 to 0.85 g / cm ³ .   The artificial leather according to claim 1, wherein the yarn constituting the woven fabric is a twisted yarn having a twist number of 1000 T / m to 3500 T / m.   It is characterized in that the thread-like component constituting the fabric is a polyester, and the copolymer component capable of imparting high shrinkage properties to the polyester is contained in a proportion of 2 mol% or more and 20 mol% or less. The artificial leather according to claim 1 or 2.   The artificial leather according to any one of claims 1 to 3, wherein the copolymerization component of the fibers constituting the fabric is isophthalic acid or bisphenol A.   Artificial leather in which a high molecular weight elastic material is applied as a binder to a fiber entangled body in which a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.3 μm to 7.0 μm and a woven fabric are laminated and integrated, 2. The method of manufacturing an artificial leather according to claim 1, wherein the dyeing is controlled so that the area retention rate at time becomes 50% or more and 75% or less.   The method for producing an artificial leather according to claim 5, wherein the yarn constituting the woven fabric is a twisted yarn having a twist number of 1000 T / m to 3500 T / m.   It is characterized in that the thread-like component constituting the fabric is a polyester, and the copolymer component capable of imparting high shrinkage properties to the polyester is contained in a proportion of 2 mol% or more and 20 mol% or less. The manufacturing method of the artificial leather of Claim 5 or 6.   The method for producing an artificial leather according to any one of claims 5 to 7, wherein a copolymerization component of fibers constituting the fabric is isophthalic acid or bisphenol A.   Artificial leather in which a high molecular weight elastic material is applied as a binder to a fiber entangled body in which a nonwoven fabric made of ultrafine fibers having an average single fiber diameter of 0.3 μm to 7.0 μm and a woven fabric are laminated and integrated, The method for producing an artificial leather according to claim 1, wherein a pressing process is performed later.