Artificial leather and its manufacturing methods

Abstract

Regarding artificial leather comprising a fiber complex and a polymer elastomer, wherein the fiber complex comprises a nonwoven fabric formed from extremely fine fibers containing a large number of inorganic particles (especially metal compounds) as a constituent element, in order to provide artificial leather that balances strength (especially tensile strength and tear strength), quality, and density, the artificial leather of the present invention is an artificial leather comprising a fiber complex and a polymer elastomer, wherein the fiber complex comprises a nonwoven fabric containing extremely fine fibers with an average single fiber diameter of 1.0 μm or more and 10.0 μm or less as a constituent element, and satisfies the following requirements: (1) The extremely fine fibers comprise a polyester resin containing a manganese compound. (2) The average particle size of the manganese compound is 0.01 μm or more and 0.20 μm or less. (3) In 100% by mass of the extremely fine fibers, the extremely fine fibers contain 0.1 ppm or more and 50.0 ppm of manganese.

Description

Technical Field

[0001] This invention relates to artificial leather with excellent tensile strength, tear strength, texture, and density. Background Technology

[0002] Suede-like artificial leather, comprising fiber complexes and polymer elastomers, with the fiber complexes mainly consisting of nonwoven fabrics containing extremely fine fibers, possesses superior durability and uniformity of quality compared to natural leather. It is used in a wide range of applications, including automotive interior materials, furniture, general merchandise, and clothing. In automotive interior materials, sheet applications require durability (strength) and abrasion resistance to withstand repeated getting in and out of vehicles; while dashboard and instrument panel applications require properties such as light resistance to withstand light exposure.

[0003] In the aforementioned applications, pigments are often added to nonwoven fabrics used as fiber complexes to achieve a dark and uniform color development. Additionally, titanium dioxide is sometimes added to enhance the brightness of artificial leather, in addition to increasing the reaction rate during polymerization of raw materials. However, when using raw materials containing a large amount of inorganic particles (metallic compounds), the strength and rigidity of the fibers sometimes decrease. As a result, in the initial stages of fiber complexation, the nonwoven fabric tends to weaken in the thickness direction, leading to poorer complexation and a tendency to compromise the strength, texture, and density of the artificial leather. Therefore, for artificial leather using raw materials containing a large amount of inorganic particles, a method that balances strength, texture, and density is increasingly needed.

[0004] As examples of such technologies, Patent Document 1 proposes a method to improve spinnability and overall yield by using titanium or aluminum atoms as polymerization catalysts for ultrafine fibers instead of antimony catalysts, which are prone to causing defects in raw cotton. Furthermore, Patent Document 2 proposes a method to obtain polyester fibers with excellent moisture absorption and hydrolysis resistance by including alkali metal phosphates in polyester fibers. Additionally, Patent Document 3 proposes a method to obtain polyester fibers with excellent lightfastness by including manganese compounds in polyester fibers.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-231638

[0008] Patent Document 2: Japanese Patent Application Publication No. 2015-81277

[0009] Patent Document 3: Japanese Patent Application Publication No. 2003-20329 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The artificial leather obtained by the method disclosed in Patent Document 1 has improved spinnability and overall yield to a certain extent because titanium or aluminum atoms are used instead of antimony catalysts. However, there are problems such as the resulting polymer having a yellowish hue and poor heat resistance.

[0012] Polyester fibers obtained by the methods disclosed in Patent Documents 2 and 3 do not require special additives and can impart functions such as moisture absorption and light resistance to the fibers to a certain extent, thus improving spinnability to a certain extent. However, when the fibers are made finer, it is difficult to maintain the fiber strength and stiffness, and there is a problem that the nonwoven fabric is prone to weakening in the thickness direction during the process of promoting fiber complexation.

[0013] Therefore, the present invention was made in view of the above circumstances, and its object is to provide artificial leather that takes into account strength (especially tensile strength and tear strength), taste and density, for artificial leather comprising a fiber complex and a polymer elastomer, wherein the fiber complex comprises a nonwoven fabric formed of extremely fine fibers containing a large number of inorganic particles (especially metal compounds) as a constituent element.

[0014] Methods for solving problems

[0015] To achieve the above objectives, the inventors of this application conducted repeated research and discovered that by adding manganese compounds to the ultrafine fibers constituting the fiber complex of artificial leather, and ensuring that the amount added and the average particle size are within a specified range, processing can be carried out without impairing the operability of spinning, and the decrease in the strength of the ultrafine fibers can be suppressed, thereby obtaining artificial leather that also takes into account taste and density.

[0016] The present invention is based on the above insights, and the following invention is provided according to the present invention.

[0017] That is, the artificial leather of the present invention is an artificial leather comprising a fiber complex and a polymer elastomer, wherein the fiber complex comprises a nonwoven fabric containing extremely fine fibers with an average single fiber diameter of 1.0 μm or more and 10.0 μm or less as a constituent element, and wherein the artificial leather satisfies the following requirements.

[0018] (1) The above-mentioned ultrafine fibers contain polyester resins containing manganese compounds.

[0019] (2) The average particle size of the above manganese compounds is above 0.01 μm and below 0.20 μm.

[0020] (3) In 100% by mass of the ultrafine fibers, the ultrafine fibers contain 0.1 ppm to 50.0 ppm of manganese.

[0021] According to a preferred embodiment of the artificial leather of the present invention, the aforementioned fine fibers further contain phosphorus compounds.

[0022] According to a preferred embodiment of the artificial leather of the present invention, the molar equivalent A of manganese contained in the aforementioned fine fibers and the molar equivalent B of phosphorus contained in the aforementioned fine fibers satisfy the molar ratio relationship of the following formula (I).

[0023] 20≤B / A≤200…(I).

[0024] In a preferred embodiment of the artificial leather according to the present invention, the aforementioned fine fibers further contain carbon black.

[0025] According to a preferred embodiment of the artificial leather of the present invention, the fiber complex comprises only the aforementioned nonwoven fabric.

[0026] According to a preferred embodiment of the artificial leather of the present invention, the fiber complex further comprises a woven fabric and is formed by complexing the nonwoven fabric and the woven fabric together.

[0027] Furthermore, the manufacturing method of the artificial leather of the present invention preferably includes: an island-type composite fiber forming step, in which a polyester resin containing a manganese-based compound with an average particle size of 0.01 μm to 0.20 μm is used as an island component and a thermoplastic resin with a solvent solubility different from that of the island component is used as a sea component for island-type composite spinning; a fiber complex forming step, in which a fiber complex containing the above-mentioned island-type composite fiber is formed; an ultrafine fiber forming step, in which the above-mentioned sea component is dissolved and removed from the above-mentioned island-type composite fiber to form ultrafine fibers with an average single fiber diameter of 1.0 μm to 10.0 μm; and a polymer elastomer imparting step, in which a polymer elastomer is imparted to the above-mentioned fiber complex.

[0028] The effects of the invention

[0029] According to the present invention, the weakening of the nonwoven fabric in the thickness direction during the fiber complexing process can be suppressed, so that the fiber complex can be further complexed to obtain artificial leather that not only has excellent durability (strength) and wear resistance to withstand repeated friction, but also has excellent taste and surface density. Detailed Implementation

[0030] The artificial leather of the present invention is an artificial leather comprising a fiber complex and a polymer elastomer. The fiber complex comprises a nonwoven fabric containing extremely fine fibers with an average single fiber diameter of 1.0 μm to 10.0 μm as a constituent element, wherein the artificial leather satisfies the following requirements.

[0031] (1) The above-mentioned ultrafine fibers contain polyester resins containing manganese compounds.

[0032] (2) The average particle size of the above manganese compounds is above 0.01 μm and below 0.20 μm.

[0033] (3) In 100% by mass of the ultrafine fibers, the ultrafine fibers contain 0.1 ppm to 50.0 ppm of manganese.

[0034] These constituent elements will now be described in detail, but the present invention is not limited by the scope of the following description unless it departs from its spirit.

[0035] [Fiber complex]

[0036] From the viewpoint of durability, especially mechanical strength and heat resistance, the ultrafine fibers constituting the fiber complex used in this invention comprise polyester resin.

[0037] Examples of the aforementioned polyester resins include polyethylene terephthalate, polyethylene terephthalate, polyethylene butylene terephthalate, polycyclohexyldimethyl terephthalate, polyethylene-2,6-naphthalenedicarboxylate, and polyethylene-1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate. Among these, polyethylene terephthalate, the most common type, or polyester copolymers primarily comprising polyethylene terephthalate units are preferred.

[0038] Furthermore, as the aforementioned polyester resin, a single polyester or two or more different polyesters may be used. However, when two or more different polyesters are used, from the viewpoint of the compatibility of the two or more components, the difference in intrinsic viscosity (IV value) of the polyester used is preferably 0.50 or less, and more preferably 0.30 or less.

[0039] In this invention, the intrinsic viscosity is calculated using the following method.

[0040] (1) Dissolve 0.8 g of the sample polymer in 10 mL of o-chlorophenol.

[0041] (2) Using an Orthocrite viscometer at a temperature of 25°C, calculate the relative viscosity η using the following formula. r Round the third decimal place.

[0042] η r =η / η0=(t×d) / (t0×d0)

[0043] Intrinsic viscosity (IV value) = 0.0242η r +0.2634

[0044] (Where, η represents the viscosity of the polymer solution, η0 represents the viscosity of o-chlorophenol, t represents the drop time of the solution (seconds), and d represents the density of the solution (g / cm³).) 3), t0 represents the falling time of o-chlorophenol (seconds), and d0 represents the density of o-chlorophenol (g / cm³). 3 ). )

[0045] From a processing and operability point of view, a circular cross-section is preferred for the cross-sectional shape of ultrafine fibers, but irregular cross-sectional shapes such as elliptical, flat, triangular, polygonal, sector, cross, hollow, Y-shaped, T-shaped, and U-shaped cross-sections can also be used.

[0046] The average single fiber diameter of the ultrafine fibers is 1.0 μm or more and 10.0 μm or less. By making the average single fiber diameter of the ultrafine fibers 1.0 μm or more, preferably 1.5 μm or more, excellent color development after dyeing, lightfastness and rubbing fastness, and stability during spinning are achieved. On the other hand, by making the average single fiber diameter of the ultrafine fibers 10.0 μm or less, preferably 6.0 μm or less, and more preferably 4.5 μm or less, dense and soft-touch artificial leather with excellent surface texture can be obtained.

[0047] In this invention, the average single fiber diameter of the ultrafine fibers refers to the following: A scanning electron microscope (SEM) image of the cross-section of the artificial leather is taken; 10 circular or nearly circular elliptical ultrafine fibers are randomly selected; the diameter of each fiber is measured; the arithmetic mean of the 10 fibers is calculated; and the result is rounded to the nearest decimal place. In the case of ultrafine fibers with irregular cross-sections, the cross-sectional area of ​​each fiber is first measured; the diameter is calculated when the cross-section is considered circular; and the diameter of the single fiber is then determined.

[0048] Furthermore, in the artificial leather of the present invention, the aforementioned ultrafine fibers contain polyester containing manganese-based compounds. This allows for the production of artificial leather with excellent tensile and tear strength. Moreover, the average particle size of the manganese-based compound is 0.01 μm to 0.20 μm, and the ultrafine fibers contain 0.1 ppm to 50.0 ppm (0.0001% to 0.0050% by mass) of manganese relative to 100% by mass. Since manganese exists in an ionic state in the ultrafine fibers, it is a metal with reducing power. Therefore, during the formation of ultrafine fibers, for example, when spinning island-type composite fibers, the free radicals generated by the oxidative decomposition of the island component (e.g., polyethylene terephthalate, PET) and the sea component (e.g., polystyrene, PST) can be deactivated, thus suppressing further oxidative decomposition. As a result, the rigidity of the ultrafine fiber-manifesting fiber, i.e., the island-type composite fiber, can be improved. Consequently, it becomes less prone to fatigue in the thickness direction during the initial needle-punching stage, thus improving the complexation efficiency and producing artificial leather with excellent strength.

[0049] The particle size referred to here is the particle size of manganese compounds in the state of aggregated existence in extremely fine fibers, which is usually called secondary particle size.

[0050] By making the average particle size (hereinafter sometimes simply referred to as average particle size) 0.01 μm or more, preferably 0.02 μm or more, and more preferably 0.04 μm or more, manganese compounds can also exist at the interface between the island component and the sea component, thereby deactivating free radicals generated by oxidative decomposition. In addition, by making the average particle size 0.20 μm or less, preferably 0.18 μm or less, and more preferably 0.16 μm or less, excellent stability and filament strength are achieved during spinning.

[0051] Furthermore, by ensuring that the manganese content in the ultrafine fibers is 0.1 ppm (0.0001 wt%) or more, preferably 0.2 ppm (0.0002 wt%) or more, more preferably 0.3 ppm (0.0003 wt%) or more, further preferably 0.5 ppm (0.0005 wt%) or more, and particularly preferably 1.0 ppm (0.0010 wt%) or more, relative to 100 wt% of the ultrafine fibers, the rigidity of the ultrafine fibers and the island-type composite fibers can be improved. Additionally, by ensuring that the manganese content in the ultrafine fibers is 50.0 ppm (0.0050 wt%) or less, preferably 45.0 ppm (0.0045 wt%) or less, more preferably 40.0 ppm (0.0040 wt%) or less, and further preferably 30 ppm (0.0030 wt%) or less, relative to 100 wt% of the ultrafine fibers, excellent stability and fiber strength during spinning are achieved.

[0052] In this invention, the average particle size is calculated using the following method.

[0053] (1) Prepare ultrathin slices with a thickness of 5 to 10 μm along the cross-sectional direction of the plane perpendicular to the length direction of the ultrafine fiber.

[0054] (2) The fiber cross-section in the ultrathin section was observed using energy dispersive X-ray spectroscopy (TEM-EDX).

[0055] (3) By irradiating the region to be analyzed with electron beams to generate X-rays specific to atoms, the energy and number of times these X-rays are generated are measured to determine the particles containing manganese atoms. The total particle size of the determined particles containing manganese atoms is then measured.

[0056] (4) Calculate the average value (arithmetic mean) for all measured particle sizes.

[0057] In addition, in this invention, the mass ratio of manganese contained in the ultrafine fibers is determined by the following method.

[0058] (1) Dissolve the artificial leather completely with acid to obtain a sample solution.

[0059] (2) The manganese element was determined by an ICP luminescence spectrophotometer, and the mass ratio of manganese element was calculated from the mass ratio of the fine fibers in the artificial leather dissolved in the sample solution.

[0060] Manganese acetate, manganese nitrate, manganese sulfate, manganese chloride, etc., can be used as manganese compounds in this invention. From the viewpoint of excellent solubility and catalytic activity, manganese acetate is preferred as a manganese compound.

[0061] In this invention, in order to make the charge of the entire ultrafine fiber close to 0 relative to manganese which exists in an ionic state, from the viewpoint of resistance to damp heat and heat resistance, the polyester resin constituting the ultrafine fiber preferably contains a phosphorus compound, and preferably the molar equivalent A of manganese element contained in the ultrafine fiber and the molar equivalent B of phosphorus element contained in the ultrafine fiber satisfy the molar ratio of the following formula (I).

[0062] 20≤B / A≤200···Formula (I).

[0063] By making the molar ratio (B / A) of the manganese molar equivalent A in the ultrafine fiber to the phosphorus molar equivalent B in the ultrafine fiber 20 or more (20 ≤ B / A, and so on), more preferably 25 or more, and even more preferably 30 or more, the overall charge of the ultrafine fiber can be stabilized close to 0 relative to manganese in an ionic state. Furthermore, by making the molar ratio (B / A) of the manganese molar equivalent A in the ultrafine fiber to the phosphorus molar equivalent B in the ultrafine fiber 200 or less (B / A ≤ 200, and so on), more preferably 150 or less, even more preferably 120 or less, and particularly preferably 90 or less, excellent stability and fiber strength are achieved during spinning.

[0064] In this invention, the mass ratio of phosphorus in the ultrafine fibers is determined by the following method: the mass ratios of phosphorus and manganese are converted into molar values, and the molar equivalent of phosphorus B is divided by the molar equivalent of manganese A to calculate B / A.

[0065] (1) Dissolve the artificial leather thoroughly with acid to obtain a sample solution.

[0066] (2) The phosphorus element was determined by an ICP luminescence spectrophotometer, and the mass ratio of phosphorus element was calculated from the mass ratio of the fine fibers in the artificial leather dissolved in the sample solution.

[0067] Phosphoric acid, trimethyl phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, etc., can be used as phosphoric acid compounds in this invention. Among them, from the viewpoint of excellent hydrolysis resistance, trimethyl phosphate and sodium dihydrogen phosphate are preferred phosphoric acid compounds.

[0068] In this invention, the aforementioned ultrafine fibers preferably also contain carbon black. Carbon black readily yields fine-particle-size black pigments and exhibits excellent dispersibility in polymers. Therefore, by further containing carbon black in the ultrafine fibers, excellent deep and uniform color development can be achieved, along with excellent color fastness, abrasion resistance, and strength.

[0069] It should be noted that, in addition to carbon black, inorganic particles such as titanium dioxide particles, lubricants, heat stabilizers, ultraviolet absorbers, conductive agents, heat storage agents, and antibacterial agents may be added to the polyester resin that forms the ultrafine fibers, depending on the purpose, without impairing the purpose of the present invention.

[0070] Regarding the artificial leather of the present invention, a fiber complex comprising a nonwoven fabric made of the above-mentioned polyester resin-containing fine fibers is one of the constituent elements.

[0071] In this invention, "fiber complex comprising nonwoven fabric as a constituent element" means: the fiber complex is in the form of nonwoven fabric, the fiber complex as described later is formed by integrating nonwoven fabric and woven fabric, and the fiber complex is formed by integrating nonwoven fabric and substrate other than woven fabric.

[0072] By creating a fiber complex that includes nonwoven fabric as a component, a uniform and beautiful appearance and feel can be obtained when the surface is napped.

[0073] As forms of nonwoven fabric, there are long-fiber nonwoven fabrics mainly composed of filaments and short-fiber nonwoven fabrics mainly composed of fibers less than 100mm. When using long-fiber nonwoven fabric as the fibrous base material, artificial leather with excellent strength can be obtained, and therefore it is preferred. On the other hand, when using short-fiber nonwoven fabric, compared to long-fiber nonwoven fabric, more fibers can be oriented in the thickness direction of the artificial leather, resulting in a highly dense surface when the artificial leather is napped.

[0074] When using short-fiber nonwoven fabric, the fiber length of the ultrafine fibers is preferably 25 mm or more and 90 mm or less. By making the fiber length 90 mm or less, more preferably 80 mm or less, and even more preferably 70 mm or less, a good texture and feel are achieved. On the other hand, by making the fiber length 25 mm or more, more preferably 35 mm or more, and even more preferably 40 mm or more, it is possible to produce artificial leather with excellent abrasion resistance.

[0075] The area mass of the nonwoven fabric constituting the artificial leather of the present invention is determined according to "6.2 Mass per unit area (ISO method)" of JIS L1913:2010 "General nonwoven fabrics test methods", preferably 50 g / m². 2 Above 600g / m 2 The following range. This is achieved by making the unit area mass of the above nonwoven fabric 50 g / m². 2 The above, and more preferably 80g / m 2 The above methods enable the production of artificial leather with a substantial feel and excellent hand texture. On the other hand, by achieving a nonwoven fabric with a unit area mass of 600 g / m²... 2 The following, or more preferably, is 500g / m 2 This allows for the production of soft, moldable artificial leather.

[0076] In the artificial leather of the present invention, in order to improve its strength and morphological stability, it is preferable to integrate the woven fabric by laminating it inside or on one side of the nonwoven fabric.

[0077] As for the type of fiber constituting the woven fabric used in the case of integrating the above-mentioned woven fabric, it is preferable to use filament yarn, fine yarn, or a composite yarn of filament yarn and fine yarn. From the viewpoint of durability, especially mechanical strength, it is more preferable to use multifilament formed by polyester resin or polyamide resin.

[0078] Furthermore, from the viewpoint of mechanical strength, it is preferable that the fibers constituting the above-mentioned woven fabric do not contain inorganic particles.

[0079] By making the average single fiber diameter of the fibers constituting the above-mentioned woven fabric preferably 50.0 μm or less, more preferably 15.0 μm or less, and even more preferably 13.0 μm or less, not only can artificial leather with excellent softness be obtained, but also the hue difference between the fibers of the woven fabric and the ultrafine fibers containing pigment after dyeing is reduced even when the fibers of the woven fabric are exposed on the surface of the artificial leather, so as not to damage the uniformity of the surface hue. On the other hand, by making the average single fiber diameter preferably 1.0 μm or more, more preferably 8.0 μm or more, and even more preferably 9.0 μm or more, the morphological stability of the artificial leather product is improved.

[0080] In this invention, the average single fiber diameter of the fibers constituting the woven fabric is calculated by the following method: taking a scanning electron microscope (SEM) image of the cross-section of the artificial leather, randomly selecting 10 fibers constituting the woven fabric, measuring the single fiber diameter of the fiber, calculating the arithmetic mean of the 10 fibers, and rounding the second decimal place.

[0081] When the fibers constituting the above-mentioned woven fabric are multifilaments, the total fineness of the multifilaments is determined by JIS L1013:2010 "Test Methods for Chemical Fiber Filament Yarns" "8.3 Fineness" "8.3.1 Positive Fineness b) Method B (Simplified Method)", preferably 30 dtex or more and 170 dtex or less.

[0082] By making the total fineness of the yarns constituting the woven fabric 170 dtex or less, artificial leather with excellent softness can be obtained. On the other hand, by making the total fineness 30 dtex or more, not only is the morphological stability of the artificial leather product improved, but also, when nonwoven fabric and woven fabric are bonded together by needle punching or the like, the fibers constituting the woven fabric are less likely to protrude from the surface of the artificial leather, which is therefore preferable. In this case, it is preferable that the total fineness of the warp and weft multifilaments is the same.

[0083] Furthermore, the twist of the yarn constituting the aforementioned woven fabric is preferably 1000 T / m or more and 4000 T / m or less. By making the twist 4000 T / m or less, more preferably 3500 T / m or less, and even more preferably 3000 T / m or less, artificial leather with excellent softness can be obtained; by making the twist 1000 T / m or more, more preferably 1500 T / m or more, and even more preferably 2000 T / m or more, damage to the fibers constituting the woven fabric can be prevented when the nonwoven fabric and the woven fabric are bonded together by needle punching or the like, and the artificial leather has excellent mechanical strength, which is therefore preferred.

[0084] [Polymer Elastomers]

[0085] The polymeric elastomer constituting the artificial leather of the present invention is an adhesive (binder) that holds the extremely fine fibers constituting the artificial leather. Therefore, considering the soft feel of the artificial leather of the present invention, polyurethane is preferably used as the polymeric elastomer.

[0086] In this invention, the polyurethane preferably used as a polymeric elastomer can be either an organic solvent-based polyurethane used in a state dissolved in an organic solvent, or a water-dispersible polyurethane used in a state dispersed in water. Furthermore, as a preferred polyurethane for use in this invention, a polyurethane obtained by reacting a polymeric diol, an organic diisocyanate, and a chain extender can be cited.

[0087] As the aforementioned polymer diol, examples include polycarbonate diols, polyester diols, polyether diols, silicone diols, and fluorinated diols, as well as copolymers composed of these. Among these, from the viewpoint of hydrolysis resistance and abrasion resistance, the use of polycarbonate diols is more preferred.

[0088] The aforementioned polycarbonate diols can be manufactured through transesterification of alkylene glycols with carbonates, or through the reaction of phosgene or chloroformate with alkylene glycols.

[0089] In addition, examples of alkylene glycols include linear alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol; branched alkylene glycols such as 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 2-methyl-1,8-octanediol; alicyclic glycols such as 1,4-cyclohexanediol; aromatic glycols such as bisphenol A; glycerol; trimethylolpropane; and pentaerythritol. In this invention, polycarbonate diols obtained from individual alkylene glycols and copolycarbonate diols obtained from two or more alkylene glycols can be used.

[0090] In addition, polyester diols can be cited as examples of polyester diols obtained by condensing various low molecular weight polyols with polyacids.

[0091] As a low molecular weight polyol, for example, one or more of the following can be used: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, and cyclohexane-1,4-diethanol.

[0092] Alternatively, adducts obtained by adding various epoxides to bisphenol A can also be used.

[0093] In addition, as a polyacid, examples include one or more of the following groups: succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydroisophthalic acid.

[0094] Examples of polyether diols used in this invention include polyethylene glycol, polypropylene glycol, polybutane glycol, and copolydiols composed of these.

[0095] For the number-average molecular weight of the polymer glycol, when the molecular weight of the polyurethane elastomer is constant, it is preferably in the range of 500 to 4000. By making the number-average molecular weight preferably 500 or more, and more preferably 1500 or more, it is possible to prevent the artificial leather from hardening. In addition, by making the number-average molecular weight preferably 4000 or less, and more preferably 3000 or less, it is possible to maintain the strength of the polyurethane.

[0096] As preferred organic diisocyanates used in this invention, examples include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and phenyl diisocyanate, aromatic diisocyanates such as diphenylmethane diisocyanate and toluene diisocyanate, and they can also be used in combination.

[0097] As chain extenders, amine-based chain extenders such as ethylenediamine and methylenebisphenylamine, and diol-based chain extenders such as ethylene glycol are preferred. Alternatively, polyamines obtained by reacting polyisocyanates with water can also be used as chain extenders.

[0098] In this invention, polyurethane, which is preferably used as a polymeric elastomer, can be combined with a crosslinking agent for the purpose of improving water resistance, abrasion resistance, and hydrolysis resistance. The crosslinking agent can be an external crosslinking agent added relative to polyurethane as a third component; alternatively, an internal crosslinking agent can be used, which pre-introduces reaction sites into the polyurethane molecular structure to form a crosslinked structure. From the viewpoint of enabling more uniform formation of crosslinking points within the polyurethane molecular structure and reducing the reduction in flexibility, an internal crosslinking agent is preferred.

[0099] As a crosslinking agent, compounds having isocyanate groups, oxazoline groups, carbodiimide groups, epoxy groups, melamine resin groups, and silanol groups can be used.

[0100] In addition, depending on the purpose, polymeric elastomers may contain various additives, such as flame retardants (phosphorus-based, halogen-based, and inorganic-based), antioxidants (phenol-based, sulfur-based, and phosphorus-based), UV absorbers (benzotriazole-based, benzophenone-based, salicylate-based, cyanoacrylate-based, and oxaloaniline-based), light stabilizers (hindered amine-based and benzoate-based), hydrolysis-resistant stabilizers (polycarbodiimide-based), plasticizers, antistatic agents, surfactants, coagulation modifiers, carbon black, and dyes.

[0101] Typically, the content of polymeric elastomers in artificial leather can be appropriately adjusted considering the type of polymeric elastomer used, its manufacturing method, and its feel and physical properties. However, in this invention, the content of polymeric elastomers is preferably 10% by mass or more and 60% by mass or less relative to the mass of the fiber complex. By making the content of the aforementioned polymeric elastomers 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, the bonding between fibers based on polymeric elastomers can be enhanced, thereby improving the abrasion resistance of the artificial leather. On the other hand, by making the content of the aforementioned polymeric elastomers 60% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, the artificial leather can have higher softness.

[0102] [Artificial Leather]

[0103] In the artificial leather of the present invention, it is preferable to have a nap on the surface. The nap may be present only on one side of the artificial leather, or it may be present on both sides. That is, in the surface of the artificial leather, if the surface with the nap is taken as the napped surface, then at least one side of the artificial leather may be the napped surface, or both sides may be the napped surface.

[0104] From a design perspective, when the surface has a fuzzy texture, the preferred fuzz length and direction softness are such that when a finger is swiped across it, the direction of the fuzz changes and leaves a mark, known as a fingerprint.

[0105] More specifically, the pile length of the surface is preferably 200 μm to 500 μm, more preferably 250 μm to 450 μm. By making the pile length 200 μm or more, the surface pile is coated with a polymer elastomer, suppressing the polymer elastomer from exposing to the surface of the artificial leather, thereby obtaining artificial leather with excellent texture and density. Furthermore, when the woven fabric and the nonwoven fabric constituting the artificial leather are integrated, by making the surface pile length within the above range, the fibers of the woven fabric near the surface of the artificial leather can be sufficiently covered, which is therefore preferable. On the other hand, by making the pile length 500 μm or less, artificial leather with excellent design effect and wear resistance can be obtained.

[0106] In this invention, the nap length of the artificial leather is calculated using the following method.

[0107] (1) Using a cotton brush or similar tool to make the nap of the artificial leather stand upside down, make a 1mm thick slice along the cross-sectional direction of the surface perpendicular to the length of the artificial leather.

[0108] (2) The cross section of the artificial leather was observed at 90x magnification using a scanning electron microscope (SEM).

[0109] (3) In the captured SEM images, the height of the pile portion (a layer containing only ultrafine fibers) at 200 μm intervals was measured at 10 locations in the width direction of the cross section of the artificial leather.

[0110] (4) Calculate the average (arithmetic mean) of the height of the villous portion (layer containing only the finest fibers) at the 10 measured locations.

[0111] In the artificial leather of the present invention, the proportion of the pile covering the pile surface (pile coverage rate) of the artificial leather is preferably 50% to 100%. By making the pile coverage rate 50% or more, the exposure of the polymer elastomer to the surface of the artificial leather can be suppressed, thus obtaining artificial leather with excellent texture and density. In the present invention, by keeping the average particle size and content of the manganese compounds contained in the pile (fine fibers) within a specified range, the fiber strength of the pile (fine fibers) can be improved. Therefore, even when the pile coverage rate is as high as 50% or more, artificial leather that is not easily shed due to friction can be obtained.

[0112] The velvet coverage rate refers to the percentage of velvet area per 9 mm of surface area measured using SEM at magnifications of 30x to 90x to detect the presence of velvet. 2 The ratio of the total area of ​​the fibrous portion to the total area of ​​the non-fibrous portion is the value obtained from this. The ratio of the total area can be calculated by binarizing the captured SEM image using image analysis software such as ImageJ developed by the National Institutes of Health (NIH), setting a threshold of 100 for the fibrous and non-fibrous portions. Furthermore, in calculating the fibrous coverage rate, if non-fibrous material significantly affects the fibrous coverage rate when it is counted as fibrous material, the image should be manually edited to treat that part as a non-fibrous portion in the calculation.

[0113] As an image analysis system, the aforementioned image analysis software "ImageJ" can be used as an example. However, any image analysis system that includes image processing software capable of calculating the area ratio of specified pixels is acceptable and is not limited to the image analysis software "ImageJ". It should be noted that the image processing software "ImageJ" is a general-purpose software developed by the National Institutes of Health (NIH). This image processing software "ImageJ" has the function of defining necessary regions and performing pixel analysis on the input image.

[0114] The thickness of the artificial leather of the present invention, measured by method 6.1.1A of "6.1 Thickness (ISO Method)" in JIS L1913:2010 "General Test Methods for Nonwoven Fabrics", is preferably in the range of 0.2 mm to 1.2 mm. By making the thickness of the artificial leather 0.2 mm or more, more preferably 0.3 mm or more, and even more preferably 0.4 mm or more, not only is the processability during manufacturing excellent, but it also becomes an artificial leather with a substantial feel. On the other hand, by making the thickness 1.2 mm or less, more preferably 1.1 mm or less, and even more preferably 1.0 mm or less, it is possible to produce a soft artificial leather with excellent formability.

[0115] Furthermore, regarding the artificial leather of the present invention, in the abrasion resistance test determined by the "8.19.5E method (Martindale method)" of "8.19 Abrasion Strength and Color Change by Friction" in JIS L1096:2010 "Test Methods for Woven and Knitted Fabrics", the weight loss of the artificial leather after 20,000 abrasion cycles with a pressing load of 12.0 kPa is preferably 10 mg or less, more preferably 9 mg or less, and even more preferably 8.5 mg or less. By making the weight loss 10 mg or less, it is possible to prevent contamination caused by shedding of fibers during actual use.

[0116] Furthermore, the tensile strength of the artificial leather of the present invention, as determined by JIS L1913:2010 "General Test Methods for Nonwoven Fabrics" "6.3.1 Tensile Strength and Elongation (ISO Method)", is preferably 20 to 200 N / cm for any test direction.

[0117] When the tensile strength is 20 N / cm or more, more preferably 30 N / cm or more, and even more preferably 40 N / cm or more, the artificial leather exhibits excellent morphological stability and durability, and is therefore preferred. Furthermore, when the tensile strength is 200 N / cm or less, more preferably 180 N / cm or less, and even more preferably 150 N / cm or less, it becomes an artificial leather with excellent formability.

[0118] [Manufacturing methods for artificial leather]

[0119] The preferred method for manufacturing the artificial leather of the present invention is as follows. That is,

[0120] have:

[0121] In the island-type composite fiber forming process, a polyester resin containing manganese-based compounds with an average particle size of 0.01μm to 0.20μm is used as the island component, and a thermoplastic resin with solvent solubility different from the island component is used as the sea component for island-type composite spinning.

[0122] The fiber complex forming process forms a fiber complex comprising the aforementioned island-type composite fibers;

[0123] In the ultrafine fiber forming process, the aforementioned marine components are dissolved and removed from the aforementioned island-type composite fiber to form ultrafine fibers with an average single fiber diameter of 1.0 μm to 10.0 μm; and

[0124] The polymer elastomer imparting process imparts a polymer elastomer to the aforementioned fiber complex.

[0125] The following is a detailed explanation of each process.

[0126] <Processes for forming island-type composite fibers>

[0127] In this process, a polyester resin containing manganese-based compounds with an average particle size of 0.01μm to 0.20μm is used as the island component, and a thermoplastic resin with solvent solubility different from the island component is used as the sea component to carry out island-type composite spinning to produce ultra-fine fiber manifest fiber.

[0128] As a type of ultrafine fiber, a sea-island composite fiber is used. This sea-island composite fiber is made by dissolving and removing the sea component (a readily soluble polymer) using a solvent or the like, using thermoplastic resins with different solvent solubility as the sea component and the island component (a poorly soluble polymer). By using a sea-island composite fiber, appropriate gaps can be created between the island components, i.e., between the ultrafine fibers within the fiber bundle, during the removal of the sea component. Therefore, it is preferred from the viewpoint of the feel and surface finish of artificial leather.

[0129] As a method for spinning ultrafine fibers with a sea-island composite structure, from the viewpoint of obtaining ultrafine fibers with uniform single fiber fineness, it is preferable to use a polymer cross-linking structure spun by using a spinneret for sea-island composite fibers and arranging the sea and island components alternately.

[0130] When using a polyester resin containing a manganese-based compound with an average particle size of 0.01 μm to 0.20 μm as the island component, it is preferable to pre-mix the manganese-based compound with the polyester resin to form chips. This allows for easy adjustment of the amount of manganese-based compound contained in the chips, as well as the amount of manganese-based compound contained in the island-type composite fiber and the ultrafine fiber, and the average particle size of the manganese-based compound. Regarding the content of the manganese-based compound at this time, it is preferable to mix the resin in a manner that contains 0.1 ppm to 50.0 ppm (0.0001 ppm to 0.0050 ppm by mass) of manganese relative to 100% by mass of the polyester resin.

[0131] Furthermore, it is preferable that the island component that becomes ultrafine fiber in subsequent processes contains a phosphorus-based compound. Moreover, for the reasons mentioned above, it is even more preferable that the molar equivalent A of manganese element contained in the polyester resin and the molar equivalent B of phosphorus element contained in the polyester resin satisfy the molar ratio of the following formula (I).

[0132] 20≤B / A≤200···(I).

[0133] As the marine component of island-type composite fibers, polyethylene, polypropylene, polystyrene, copolyesters copolymerized with sodium sulfoisophthalate, polyethylene glycol, etc., and polylactic acid can be used. However, from the viewpoints of yarn production and easy dissolution, polystyrene and copolyesters are preferred.

[0134] In the manufacturing method of the artificial leather of the present invention, it is preferable to use island-type composite fibers with an island component strength of 2.0 cN / dtex or higher. By making the island component strength 2.0 cN / dtex or higher, more preferably 2.3 cN / dtex or higher, and even more preferably 2.8 cN / dtex or higher, the abrasion resistance of the artificial leather can be improved, and the reduction in frictional strength caused by fiber shedding can be suppressed.

[0135] In this invention, the strength of the island component of the island-type composite fiber is calculated using the following method.

[0136] (1) Bundle 10 island-type composite fibers, each 20cm long.

[0137] (2) After dissolving and removing the marine components from the sample in (1), the sample is air-dried.

[0138] (3) Using the standard time test of "8.5 Tensile strength and elongation" in JIS L1013:2010 "Test methods for chemical fiber filament yarn", 10 tests were conducted under the conditions of clamping length of 5cm, tensile speed of 5cm / min and load of 2N (N=10).

[0139] (4) Round the second decimal place of the arithmetic mean (cN / dtex) of the test results obtained in (3), and use the resulting value as the strength of the island component of the island-type composite fiber.

[0140] <Process for forming fibrous complexes>

[0141] In this process, the spun ultrafine fibers are opened and then formed into a fiber web using a crosslapper or similar machine, thereby obtaining a fiber complex containing nonwoven fabric as a component. Methods for forming the fiber web to obtain a fiber complex containing nonwoven fabric as a component include needle punching and water jet punching.

[0142] As mentioned above, as a form of nonwoven fabric, either short-fiber nonwoven fabric or long-fiber nonwoven fabric can be used. However, when using short-fiber nonwoven fabric, there are more fibers in the thickness direction of the artificial leather than in long-fiber nonwoven fabric, which can achieve a high density on the surface of the artificial leather when it is napped.

[0143] When using short-fiber nonwoven fabric as the nonwoven fabric, it is preferable to perform crimping processing on the island-type composite fibers obtained in the above-mentioned process of forming island-type composite fibers, cutting them to a specified length to obtain raw cotton, and then performing fiber opening, layering, and complexing to obtain short-fiber nonwoven fabric. The crimping and cutting processes can be performed using known methods.

[0144] Furthermore, when the fiber complex includes woven fabric, the nonwoven fabric obtained by the above method is layered with the woven fabric, and then the nonwoven fabric and woven fabric are complexed together. In the complexation of nonwoven fabric and woven fabric, woven fabric can be layered on one or both sides of the nonwoven fabric, or the woven fabric can be sandwiched between multiple nonwoven fabric webs, and then the fibers of the nonwoven fabric and woven fabric can be complexed together by needle punching, hydroentangling, etc.

[0145] The apparent density of the nonwoven fabric containing island-type composite fibers after needle punching or hydroentangling is preferably 0.15 g / cm³. 3 Above 0.45g / cm 3 The following is an example. The apparent density is preferably set to 0.15 g / cm³. 3 Thus, artificial leather can achieve sufficient morphological and dimensional stability. On the other hand, the apparent density is preferably 0.45 g / cm³. 3 This allows for the maintenance of sufficient space for imparting polymeric elastomers.

[0146] To improve the density of the fibers, it is also a preferred method to perform heat shrinkage treatment on the above-mentioned fiber complex based on warm water or steam.

[0147] Next, by impregnating the aforementioned fiber complex with an aqueous solution of a water-soluble resin and then drying it, a water-soluble resin can be imparted. By imparting a water-soluble resin to the fiber complex, the fibers are fixed, and dimensional stability is improved.

[0148] <Processes for forming ultrafine fibers>

[0149] In this process, the fibrous substrate obtained by solvent treatment forms extremely fine fibers with an average single fiber diameter of more than 1.0 μm and less than 10.0 μm.

[0150] The formation of ultrafine fibers can be achieved by immersing the aforementioned fiber complex in a solvent to dissolve and remove the marine components of the island-type composite fiber.

[0151] As solvents for dissolving and removing marine components, organic solvents such as toluene and trichloroethylene can be used when the marine component is polyethylene, polypropylene, or polystyrene. Alternatively, alkaline aqueous solutions such as sodium hydroxide can be used when the marine component is copolyester or polylactic acid. Furthermore, hot water can be used when the marine component is a water-soluble thermoplastic polyvinyl alcohol resin.

[0152] <Process for imparting polymer elastomers>

[0153] In this process, a polymer elastomer is imparted by impregnating a solution of polymer elastomer into a fiber complex mainly composed of ultrafine fibers or island-type composite fibers and then curing the polymer elastomer. Methods for curing the polymer elastomer include wet curing or dry curing after impregnating the fiber complex with a solution of polymer elastomer; these methods can be appropriately selected depending on the type of polymer elastomer used.

[0154] When polyurethane is selected as the polymeric elastomer, N,N'-dimethylformamide, dimethyl sulfoxide, etc., are preferred solvents. Alternatively, an aqueous dispersion of polyurethane, prepared by dispersing polyurethane as an emulsion in water, can also be used.

[0155] It should be noted that the application of polymeric elastomers to the fiber complex can be done before or after the production of ultrafine fibers from island-type composite fibers.

[0156] <The process of cutting and grinding artificial leather>

[0157] After completing the above processes, from the point of view of manufacturing efficiency, it is also a preferred method to cut the artificial leather made of polymer elastomer into two pieces in the thickness direction to make two pieces of artificial leather.

[0158] Furthermore, a napping treatment is applied to the surface of the aforementioned artificial leather made with a polymer elastomer or artificial leather cut in half. The napping treatment can be performed by grinding with sandpaper, a roll sander, or similar methods. The napping treatment can be applied to only one side of the artificial leather or to both sides.

[0159] When performing a napping process, a lubricant such as a silicone emulsion can be applied to the surface of the artificial leather before the napping process. Additionally, by applying an antistatic agent before the napping process, grinding powder generated from the artificial leather during grinding is less likely to accumulate on the sandpaper. This process creates artificial leather.

[0160] <The process of dyeing artificial leather>

[0161] As for dyeing treatments, various methods can be used, such as immersion dyeing using a roller dyeing machine, liquid flow dyeing using a liquid flow dyeing machine, hot melt dyeing using a continuous dyeing machine, or dyeing of the napped surface using methods such as roller dyeing, screen dyeing, inkjet dyeing, sublimation dyeing, and vacuum sublimation dyeing. Among these, liquid flow dyeing machines are preferred for achieving a soft hand feel and for improving quality and appearance. Furthermore, various resin finishing processes can be performed after dyeing, as needed.

[0162] Post-processing steps

[0163] In addition, the surface of the aforementioned artificial leather can be customized as needed. For example, post-processing treatments such as perforation, embossing, laser processing, Pinsonic processing, and printing can be applied.

[0164] The artificial leather of the present invention, obtained by the manufacturing method described above, has a soft touch similar to natural leather and excellent strength, quality, and density. It can be widely used in a wide range of applications, from furniture, chairs, and vehicle interior materials to clothing. In particular, considering its excellent strength, it is suitable for use in vehicle interior materials.

[0165] Example

[0166] The artificial leather of the present invention will be further described in detail below using examples, but the present invention is not limited to these examples. The evaluation methods and measurement conditions used in the examples will be described below. Unless otherwise specified, the measurements of each physical property were performed based on the methods described above.

[0167] [Determination methods and processing methods for evaluation]

[0168] (1) Average single fiber diameter (μm) of ultrafine fibers:

[0169] In determining the average single fiber diameter of ultrafine fibers, the ultrafine fibers were observed using a scanning electron microscope manufactured by KEYENCE Co., Ltd. (Type VHX-D500 / D510), and the average single fiber diameter was calculated using the method described above.

[0170] (2) Average particle size (μm) of manganese compounds contained in the ultrafine fibers:

[0171] The measurements were performed using the method described above. It should be noted that ultrathin sections with a cross-sectional direction perpendicular to the length of the extremely fine fibers were prepared using a Sorvall MT6000 ultramicrotome. The resulting sections were observed using a transmission electron microscope (Hitachi High Technologies H7700) using the same method. Next, regarding the particle size of the manganese compounds, all observed particles were measured using image analysis software (WinROOF, Mitani Corporation).

[0172] (3) Mass percentage (ppm) of manganese in the ultrafine fibers:

[0173] The mass ratio of manganese in the ultrafine fibers was determined using the ICP luminescence spectrophotometer "PS3520VDDII" manufactured by Hitachi High-Tech Science Co., Ltd., using the method described above. The mass ratio was then calculated and molar conversion was performed.

[0174] (4) Mass percentage (ppm) of phosphorus in the ultrafine fibers:

[0175] The mass ratio of phosphorus contained in the ultrafine fibers was determined using the ICP luminescence spectrophotometer "PS3520VDDII" manufactured by Hitachi High-Tech Science Co., Ltd., using the method described above. The mass ratio was then calculated and molar conversion was performed.

[0176] (5) Compression recovery rate of fiber web (%):

[0177] As a thick plate placed on the test piece, a 20×20cm plate with a 0.93g / cm thickness was used. 2 In addition to the flat plate, the compression recovery rate of the fiber web was determined according to JIS L1097:1982 "Test Method for Filling Synthetic Fibers". A compression recovery rate of 85% or higher was considered good performance.

[0178] (6) The nap coverage rate (%) of the artificial leather surface:

[0179] In the above determination of villous coverage, a scanning electron microscope manufactured by KEYENCE Co., Ltd., "VHX-D500 / D510" was used as the scanning electron microscope, and "ImageJ" (National Institutes of Health, USA) was used as the image analysis software.

[0180] (7) Pile length (μm) of artificial leather:

[0181] In the determination of the nap length of the aforementioned artificial leather, a scanning electron microscope manufactured by KEYENCE Co., Ltd., "VHX-D500 / D510 type", was used.

[0182] (8) Abrasion resistance of artificial leather:

[0183] The abrasion resistance test was conducted using the James H. Heal & Co. Ltd. "Model 406" abrasion tester and the company's "Abrastive CLOTH SM25" abrasion cloth. Artificial leather with an abrasion reduction of less than 10mg was considered qualified.

[0184] (9) Tensile strength of artificial leather:

[0185] For any orientation of the artificial leather, two 2cm × 20cm test pieces were collected, and the tensile strength specified in "6.3.1 Tensile Strength and Elongation (ISO Method)" of JIS L1913:2010 "General Nonwoven Fabrics Test Methods" was determined. The average of the two pieces was taken as the tensile strength of the sheet.

[0186] (10) Appearance and taste of flaky substances:

[0187] Regarding the aesthetic appeal of the sheet-like product, 20 evaluators (10 healthy adult males and 10 adult females) were selected. The following evaluations were assessed visually, and the highest number of evaluations was taken as the aesthetic appeal of the sheet-like product. In cases of equal numbers of evaluations, the higher evaluation was taken as the aesthetic appeal of the sheet-like product. The goodness level of this invention is designated as "A" or "B".

[0188] A: Very uniform appearance and taste

[0189] • B: Uniform appearance and taste

[0190] • C: Significant deviations in appearance and taste

[0191] • D: A very large deviation in appearance and taste.

[0192] (11) The dense feel of sheet-like objects:

[0193] Regarding the density of the sheet-like material, 20 healthy adult males and 10 healthy adult females (totaling 20 participants) were used as evaluators. The following evaluations were assessed using touch, and the highest number of evaluations was considered the density of the sheet-like material. When the number of evaluations was the same, the higher evaluation was considered the density of the sheet-like material. The good level of this invention is designated as "A" or "B".

[0194] • A: A very uniform density

[0195] • B: Uniform density

[0196] • C: A dense feel with large deviations

[0197] • D: A very high degree of density.

[0198] Polyethylene terephthalate (PET)

[0199] Regarding the use of polyethylene terephthalate A to K in the following examples and comparative examples, the manganese(II) acetate tetrahydrate, phosphoric acid, trimethyl phosphate, polyethylene terephthalate F, and carbon black, with average particle sizes as shown in Table 1, were added in the manner shown in Table 1 (calculated by ICP determination, with the total of polyethylene terephthalate, manganese(II) acetate tetrahydrate, phosphoric acid, trimethyl phosphate, and carbon black being 100% by mass, wherein the content of phosphoric acid and trimethyl phosphate was calculated based on the ratio of phosphorus content to the amount of each component added). It should be noted that in Table 1, polyethylene terephthalate A is labeled "PET A," and the same applies to polyethylene terephthalate B to K. Furthermore, the intrinsic viscosity (IV value) is the value measured after adding the aforementioned manganese(II) acetate, etc.

[0200] [Table 1]

[0201] Table 1

[0202]

[0203] [Example 1]

[0204] <Processes for forming island-type composite fibers>

[0205] Melt spinning of island-type composite fibers with island and sea components was performed under the following conditions.

[0206] • Island component: Polyethylene terephthalate A

[0207] • Sea composition: Polystyrene with an MFR (melt flow rate, determined by the test method specified in ISO 1133:1997) of 65 g / 10 min.

[0208] • Spinneret: Island-type spinneret for composite fibers with 16 islands / hole

[0209] • Spinning temperature: 285℃

[0210] • Island component / ocean component mass ratio: 80 / 20

[0211] • Dispensing volume: 1.2g / (min·hole)

[0212] Spinning speed: 1100m / minute.

[0213] Next, the island-type composite fiber was stretched to 2.81 times its original length in a steam chamber set at 150°C.

[0214] <Process for forming fibrous complexes>

[0215] First, the island-type composite fibers obtained above are crimped using a crimping machine, and then cut into 51mm lengths to form an island-type composite fiber web with a single fiber fineness of 4.2 dtex. The average single fiber diameter of the ultrafine fibers obtained from this island-type composite fiber is 4.4 μm, the strength of the ultrafine fibers is 3.5 cN / dtex, the average particle size of the manganese compounds in the ultrafine fibers is 0.10 μm, the manganese content is 3.6 ppm, and the molar ratio of manganese molar equivalent (A) to phosphorus molar equivalent (B) (B / A, the same below) is 22.2.

[0216] Then, using the island-type composite fiber web obtained as described above, a laminated web is formed through carding and cross-laying processes. Then, at a density of 2500 threads / cm... 2 The number of perforations was needle-punched to obtain a mass per unit area of ​​440 g / m². 2 A nonwoven fabric (fiber complex) with a thickness of 1.94 mm. The compression recovery rate of the fiber complex here is 89.3%. The fiber complex is not prone to softening in the thickness direction during the initial needle punching stage, which can improve the complexing properties.

[0217] <Processes for forming ultrafine fibers>

[0218] The nonwoven fabric obtained as described above is shrunk using hot water at 96°C. Then, an aqueous solution of polyvinyl alcohol (hereinafter sometimes simply referred to as PVA) with a saponification degree of 88%, prepared at a concentration of 12% by mass, is impregnated into the fiber complex that has been shrunk using hot water. Next, it is extruded using rollers and dried using hot air at 125°C for 10 minutes to allow PVA migration, resulting in a sheet containing PVA with a PVA content of 45% by mass relative to the sheet mass. The resulting PVA-containing sheet is then impregnated in trichloroethylene and subjected to 10 cycles of extrusion and compression using a rolling mill. This process removes seaweed components (de-seaweed) and compresses the PVA-containing sheet, resulting in a PVA-containing sheet composed of extremely fine fiber bundles.

[0219] <Process for imparting polymer elastomers>

[0220] A polyurethane dimethylformamide (DMF) solution, prepared in a manner where the concentration of the solid component with polyurethane as the main component is 12% by mass, is impregnated into the PVA-containing sheet obtained above. Then, the PVA-containing sheet impregnated with the polyurethane DMF solution is rolled using rollers. Next, the sheet is impregnated in a 30% by mass DMF aqueous solution to allow the polyurethane to solidify. Then, the PVA and DMF are removed with hot water, and an organosilicon oil emulsion with a concentration adjusted to 1% by mass is impregnated. An organosilicon lubricant is applied at an amount of 0.5% by mass relative to the combined mass of the fiber complex and the polyurethane, and the sheet is dried with hot air at 120°C for 10 minutes. This yields a polyurethane-containing sheet with a thickness of 1.4 mm and a polyurethane mass of 34% by mass relative to the mass of the fiber complex.

[0221] <The process of cutting in half and brushing>

[0222] The polyurethane-coated sheet obtained above is cut in half, with each half having a thickness of 1 / 2. Next, the surface of the cut half is roughened by grinding 0.25mm with 240 grit ring sandpaper to obtain a 0.45mm thick pile sheet.

[0223] <Dyeing and finishing processes>

[0224] The above-obtained fluff sheet was dyed using a liquid flow dyeing machine. Then, it was dried at 100°C for 7 minutes to obtain ultrafine fibers with an average single fiber diameter of 4.4 μm and a unit area mass of 175 g / m². 2 Artificial leather with a thickness of 0.55 mm, a pile coverage of 85%, and a pile length of 330 μm was obtained. The resulting artificial leather exhibits excellent abrasion resistance and high strength, as well as superior taste and density. The results are shown in Table 2.

[0225] [Example 2]

[0226] Using the island-type composite fiber web described in Example 1, after forming a laminated web through carding and cross-laying processes, the following plain weave fabric is laminated on top and bottom of the laminated web. The plain weave fabric is: a plain weave fabric with a weave density of 95 warp ends / 2.54cm and 76 weft ends / 2.54cm, using twisted yarns containing polyethylene terephthalate with an intrinsic viscosity (IV value) of 0.65 twisted at 2500T / m for both weft and warp yarns (average single fiber diameter: 11μm, total fineness: 84dtex, 72 filaments). The fabric has a surface area mass of 75g / m². 2 Then, at 2500 roots / cm 2 The number of perforations was needle-punched to obtain a mass per unit area of ​​700 g / m².2 A fiber complex with a thickness of 3.0 mm was obtained. Otherwise, similarly to Example 1, the average single fiber diameter of the ultrafine fibers was 4.4 μm, and the unit area mass was 320 g / m². 2 Artificial leather with a thickness of 0.9 mm, a pile coverage of 85%, and a pile length of 330 μm was obtained. The resulting artificial leather exhibits excellent abrasion resistance and very high strength, as well as excellent texture and density. The results are shown in Table 2.

[0227] [Example 3]

[0228] As the island component, polyethylene terephthalate B was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a web compression recovery rate of 87.3%, a fine fiber strength of 3.1 cN / dtex, an average particle size of 0.16 μm for manganese compounds in the fine fibers, a manganese content of 3.6 ppm, and a molar ratio (B / A) of 11.7 for manganese to phosphorus molar equivalents. The resulting artificial leather exhibited slightly lower abrasion resistance and strength, but possessed excellent texture and density. The results are shown in Table 2.

[0229] [Example 4]

[0230] As the island component, polyethylene terephthalate C was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a web compression recovery rate of 85.4%, a fine fiber strength of 2.8 cN / dtex, an average particle size of 0.04 μm for manganese compounds in the fine fibers, a manganese content of 1.2 ppm, and a molar ratio (B / A) of 140.3 for manganese to phosphorus molar equivalents. The resulting artificial leather exhibited slightly lower abrasion resistance and strength, but possessed excellent quality and high density. The results are shown in Table 2.

[0231] [Example 5]

[0232] The island-type composite fiber having an island-type composite structure containing island and sea components was melt-spun under the following conditions. Then, the ultrafine fiber-manifested fiber was stretched to 3.4 times in a spinning oil bath set at 90°C. Otherwise, artificial leather was obtained in the same manner as in Example 1.

[0233] • Island component: Polyethylene terephthalate A

[0234] • Sea composition: Polystyrene with an MFR (melt flow rate, determined by the test method specified in ISO 1133:1997) of 65 g / 10 min.

[0235] • Spinneret: Island-type spinneret for composite fibers with 16 islands / hole

[0236] • Spinning temperature: 285℃

[0237] • Island component / ocean component mass ratio: 55 / 45

[0238] • Ejection rate: 1.0g / (min·hole)

[0239] Spinning speed: 1100 m / min

[0240] The compression recovery rate of the fiber web was 86.9%, and the nonwoven fabric in the initial stage of needle punching did not easily become weak in the thickness direction, thus improving its complexing properties. The average single fiber diameter of the ultrafine fibers constituting this artificial leather was 2.9 μm, the strength of the ultrafine fibers was 3.5 cN / dtex, the average particle size of the manganese compounds in the ultrafine fibers was 0.12 μm, the manganese content was 3.6 ppm, and the molar ratio (B / A) of manganese to phosphorus was 22.2. The artificial leather obtained using this ultrafine fiber exhibited excellent abrasion resistance, as well as excellent texture and density. The results are shown in Table 2.

[0241] [Example 6]

[0242] As the island component, polyethylene terephthalate D was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 88.2%, a fine fiber strength of 3.4 cN / dtex, an average particle size of 0.08 μm for manganese compounds in the fine fibers, a manganese content of 1.2 ppm, and a molar ratio (B / A) of 62.5 for manganese to phosphorus molar equivalents. The resulting artificial leather exhibits excellent abrasion resistance and very high strength, as well as excellent texture and density. The results are shown in Table 2.

[0243] [Example 7]

[0244] The island-type composite fiber containing island and sea components was melt-spun under the following conditions, and then stretched to 3.0 times in a spinning oil bath set at 90°C. Otherwise, artificial leather was obtained in the same manner as in Example 1.

[0245] • Island component: Polyethylene terephthalate A

[0246] • Sea composition: Polystyrene with an MFR (melt flow rate, determined by the test method specified in ISO 1133:1997) of 65 g / 10 min.

[0247] • Spinneret: Island-type spinneret for composite fibers with 16 islands / hole

[0248] • Spinning temperature: 285℃

[0249] • Island component / ocean component mass ratio: 90 / 10

[0250] • Ejection rate: 1.8g / (min·hole)

[0251] Spinning speed: 1100 m / min

[0252] The compression recovery rate of the fiber web was 86.2%, and the nonwoven fabric in the initial stage of needle punching did not easily become weak in the thickness direction, thus improving its complexing properties. The average single fiber diameter of the ultrafine fibers constituting this artificial leather was 5.7 μm, the strength of the ultrafine fibers was 3.3 cN / dtex, the average particle size of the manganese compounds in the ultrafine fibers was 0.13 μm, the manganese content was 3.6 ppm, and the molar ratio (B / A) of manganese to phosphorus was 22.2. The artificial leather obtained using this ultrafine fiber exhibited excellent abrasion resistance, as well as excellent texture and density. The results are shown in Table 2.

[0253] [Example 8]

[0254] As the island component, polyethylene terephthalate E was used instead of polyethylene terephthalate A. Otherwise, similarly to Example 1, an artificial leather was obtained with a web compression recovery rate of 85.1%, a fine fiber strength of 2.9 cN / dtex, an average particle size of 0.20 μm for manganese compounds in the fine fibers, and a manganese content of 3.6 ppm. The resulting artificial leather exhibited slightly lower abrasion resistance and strength, but possessed a high-quality feel and density. The results are shown in Table 2.

[0255] [Example 9]

[0256] As the island component, polyethylene terephthalate F was used instead of polyethylene terephthalate A. Otherwise, similarly to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 89.0%, a fine fiber strength of 3.6 cN / dtex, an average particle size of 0.10 μm for manganese compounds in the fine fibers, a manganese content of 3.6 ppm, and a molar ratio (B / A) of 22.2 for manganese to phosphorus molar equivalents. The resulting artificial leather exhibits excellent abrasion resistance, high strength, a deep and very uniform color development, and excellent taste and density. The results are shown in Table 2.

[0257] [Table 2]

[0258] Table 2

[0259]

[0260] [Comparative Example 1]

[0261] As the island component, polyethylene terephthalate G, which does not contain manganese compounds, was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather with a fiber web compression recovery rate of 80.5% and a fine fiber strength of 2.8 cN / dtex was obtained. The resulting artificial leather exhibits high strength, but suffers from poor complexation due to needle punching, resulting in poor abrasion resistance, appearance, and density. The results are shown in Table 3.

[0262] [Comparative Example 2]

[0263] As the island component, polyethylene terephthalate H was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 83.2%, a fine fiber strength of 2.9 cN / dtex, an average particle size of 0.003 μm for manganese compounds in the fine fibers, a manganese content of 1.2 ppm, and a molar ratio (B / A) of 210.2 for manganese to phosphorus molar equivalents. The obtained artificial leather exhibits high abrasion resistance, but suffers from poor complexation during needle punching, resulting in poor strength, appearance, and density. The results are shown in Table 3.

[0264] [Comparative Example 3]

[0265] As the island component, polyethylene terephthalate I was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 84.1%, a fine fiber strength of 2.2 cN / dtex, an average particle size of 0.3 μm for manganese compounds in the fine fibers, a manganese content of 3.6 ppm, and a molar ratio (B / A) of 7.5 for manganese to phosphorus molar equivalents. The obtained artificial leather has a high aesthetic appeal, but poor bonding properties due to needle punching, resulting in poor strength, abrasion resistance, and density. The results are shown in Table 3.

[0266] [Comparative Example 4]

[0267] As the island component, polyethylene terephthalate J was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 82.1%, a fine fiber strength of 3.0 cN / dtex, an average particle size of 0.06 μm for manganese compounds in the fine fibers, a manganese content of 0.04 ppm, and a molar ratio (B / A) of 106.5 for manganese to phosphorus molar equivalents. The obtained artificial leather exhibits high abrasion resistance, but suffers from poor complexation during needle punching, resulting in poor strength, appearance, and density. The results are shown in Table 3.

[0268] [Comparative Example 5]

[0269] As the island component, polyethylene terephthalate K was used instead of polyethylene terephthalate A. Otherwise, similar to Example 1, an artificial leather was obtained with a fiber web compression recovery rate of 83.4%, a fine fiber strength of 2.4 cN / dtex, an average particle size of 0.14 μm for manganese compounds in the fine fibers, a manganese content of 60.0 ppm, and a molar ratio (B / A) of 24.2 for manganese to phosphorus molar equivalents. The obtained artificial leather has a high aesthetic appeal, but its poor bonding properties due to needle punching result in poor strength, abrasion resistance, and density. The results are shown in Table 3.

[0270] [Table 3]

[0271] Table 3

[0272]

[0273] As shown in Table 2, the artificial leathers of Examples 1-9 are considered to have improved rigidity by ensuring that the average particle size of the manganese compounds contained in the ultrafine fibers constituting the artificial leather is within a specific range. This allows the presence of manganese compounds at the interface between the island and marine components, thereby deactivating free radicals generated by oxidative decomposition and improving the rigidity of the composite fibers. Furthermore, by maintaining the content of manganese compounds in the ultrafine fibers constituting the artificial leather within a specific range, the rigidity of both the ultrafine fibers and the composite fibers is improved. Therefore, the fibers are less prone to fatigue in the thickness direction during the initial needle punching stage, resulting in highly complexed artificial leather with excellent appearance, texture, and density. Consequently, artificial leather with excellent stability and fiber strength during spinning can be obtained.

[0274] On the other hand, as shown in Table 3, when the fine fibers constituting the artificial leather, such as the artificial leather of Comparative Example 1, do not contain manganese compounds, when the average particle size of the manganese compounds contained in the fine fibers, such as the artificial leather of Comparative Examples 2 and 3, is outside the specified range, or when the content of manganese compounds contained in the fine fibers, such as the artificial leather of Comparative Examples 4 and 5, is outside the specified range, the strength of the fine fibers is significantly reduced, they tend to weaken in the thickness direction during the initial needle punching stage, and their complexing ability decreases. Therefore, they become artificial leather with poor wear resistance, strength, appearance, and density.

Claims

1. Artificial leather which is artificial leather comprising a fiber complex and a high molecular elastomer, the fiber complex comprising a nonwoven fabric containing ultrafine fibers having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less as a constituent element, wherein, The artificial leather satisfies the following requirements: (1) The ultrafine fibers contain a polyester-based resin containing a manganese-based compound; (2) The average particle diameter of the manganese-based compound is 0.01 μm or more and 0.20 μm or less; (3) In 100 mass% of the ultrafine fibers, the ultrafine fibers contain 0.1 ppm or more and 50.0 ppm or less of manganese element; (4) The ultrafine fibers further contain a phosphorus-based compound; (5) The molar ratio of the molar equivalent A of the manganese element contained in the ultrafine fibers to the molar equivalent B of the phosphorus element contained in the ultrafine fibers satisfies the following formula (I), 20 ≤ B / A ≤ 200 … (I).

2. The artificial leather according to claim 1, wherein, The ultrafine fibers further contain carbon black.

3. The artificial leather according to claim 1 or 2, wherein, The fiber complex contains only the nonwoven fabric.

4. The artificial leather according to claim 1 or 2, wherein, The fiber complex further contains a woven fabric, and is a complex of the nonwoven fabric and the woven fabric.

5. A method for producing the artificial leather according to any one of claims 1 to 4, comprising: an island-in-sea composite fiber forming step of performing island-in-sea composite spinning using a polyester-based resin containing a manganese-based compound having an average particle diameter of 0.01 μm or more and 0.20 μm or less as an island component and a thermoplastic resin different from the island component in solvent solubility as a sea component; a fiber complex forming step of forming a fiber complex containing the island-in-sea composite fiber; an ultrafine fiber forming step of dissolving and removing the sea component from the island-in-sea composite fiber to form an ultrafine fiber having an average single fiber diameter of 1.0 μm or more and 10.0 μm or less; and a high molecular elastomer imparting step of imparting a high molecular elastomer to the fiber complex.

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