Artificial leather, and vehicle interior surface materials containing the same.

Abstract

To provide artificial leather that contains plant fibers and has both flexibility and abrasion resistance by increasing the degree of intertwining of the fibers, and to provide a covering material for vehicle interiors that includes the artificial leather.SOLUTION: This invention relates to an artificial leather comprising a substrate made of fiber cloth and a surface fiber layer laminated on the substrate, which satisfies the following characteristics (1) to (3): (1) the substrate and the surface fiber layer both contain plant fibers; (2) the plant fiber content in the artificial leather is 50 mass% or more relative to the total mass of the artificial leather; and (3) the peel strength between the substrate and the surface fiber layer is 2 N / cm or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to artificial leather and a surface material for vehicle interiors containing the same. [Background technology]

[0002] Traditionally, artificial leather made from synthetic fibers has been widely used in furniture, clothing, automotive interiors, shoes, bags, and other applications. However, in recent years, there has been a growing demand for artificial leather made from plant fibers.

[0003] Patent Document 1 discloses that by mixing leaf fibers and curable polymer fibers in a certain ratio and thermally fusing the curable polymer fibers, artificial leather with a certain tensile strength can be obtained using plant-based raw materials. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-106158 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the invention described in Patent Document 1 does not take into account the entanglement state of the fibers to suppress surface wear, and without a resin coating on the surface, the wear resistance is insufficient. Furthermore, while the wear resistance of the invention described in Patent Document 1 improves when a resin coating is applied to the surface, flexibility is greatly reduced, making it difficult to obtain a good texture.

[0006] In view of the level of prior art described above, the problem that the present invention aims to solve is to provide an artificial leather that solves the problems of the prior art described above and achieves both flexibility and abrasion resistance by including plant fibers and increasing inter-fiber entanglement, and a vehicle interior surface material containing the same. [Means for solving the problem]

[0007] As a result of intensive studies and repeated experiments to solve the above problems, the present inventor unexpectedly found that an artificial leather having the following constitution can solve the above problems in an artificial leather containing plant fibers, and thus completed the present invention.

[0008] That is, the present invention is as follows. [1] An artificial leather comprising a base material made of a fiber cloth and a surface fiber layer laminated on the base material, having the following features (1) to (3): (1) Both the base material and the surface fiber layer contain plant fibers; (2) The content rate of plant fibers in the artificial leather is 50% by mass or more based on the total mass of the artificial leather; and (3) The peel strength between the base material and the surface fiber layer is 2 N / cm or more; An artificial leather satisfying the above. [2] The artificial leather according to [1], wherein the content rate of plant fibers in the base material is 50% by mass or more based on the total mass of the base material. [3] The artificial leather according to [1] or [2], wherein the artificial leather contains a binder resin. [4] The artificial leather according to [3], wherein the content rate of the binder resin is more than 0% by mass and 20% by mass or more based on the total mass of the artificial leather. [5] The artificial leather according to [3] or [4], wherein the binder resin is a polyurethane resin. [6] The artificial leather according to [5], wherein the polyurethane resin is an aqueous dispersion polyurethane resin. [7] The artificial leather according to any one of [1] to [6], wherein the value of the ratio L / D of the fiber length L to the single fiber diameter D of the plant fibers contained in the surface fiber layer is 50 or more and 4000 or less. [8] The artificial leather according to any one of [1] to [7], wherein the surface fiber layer contains cellulose fibrils. [9] The artificial leather according to any one of [1] to [8], wherein the specific surface area of the fibers constituting the surface fiber layer is 0.10 m 2 / g or more.

[10] Further, the following feature (4): (4) The surface fiber layer contains cellulose fibrils having a specific surface area of 0.5 m 2 / g or more and 1.5 m 2 / g or less; The artificial leather according to any one of the above [1] to [9] that satisfies the above conditions.

[11] The artificial leather according to any one of the above [1] to

[10] , wherein the surface fiber layer contains synthetic fibers.

[12] The artificial leather according to

[11] , wherein the content rate of the synthetic fibers in the surface fiber layer is 25% by mass or more and 50% by mass or less with respect to the total mass of the fibers contained in the surface fiber layer.

[13] The artificial leather according to any one of the above [1] to

[12] , wherein the base material is a woven fabric.

[14] The artificial leather according to

[13] , wherein the cover factor CF of the woven fabric is 15 or more and 40 or less.

[15] The artificial leather according to any one of the above [1] to

[13] , wherein the height Sz of the surface irregularities of the artificial leather is 200 μm or more and 600 μm or less.

[16] The artificial leather according to any one of the above [1] to

[15] , wherein the surface of the artificial leather is raised.

[17] The artificial leather according to any one of the above [1] to

[16] , wherein the artificial leather is dyed.

[18] An interior trim material for a vehicle containing the artificial leather according to any one of the above [1] to

[17] .

Advantages of the Invention

[0009] The artificial leather of the present invention and the interior trim material for a vehicle containing the same include plant fibers and achieve both flexibility and wear resistance.

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail. One embodiment of the present invention is an artificial leather including a base material made of a fiber cloth and a surface fiber layer laminated on the base material, and having the following features (1) to (3): (1) The base material and the surface fiber layer both contain plant fibers; (2) The plant fiber content in the artificial leather is 50% by mass or more of the total mass of the artificial leather; and (3) The peel strength between the substrate and the surface fiber layer is 2 N / cm or more; It is artificial leather that satisfies the requirements.

[0011] [Artificial leather] The artificial leather of this embodiment includes a base material made of fibrous fabric and a surface fiber layer laminated on the base material, wherein the surface fiber layer may be laminated on only one side of the base material or on both sides of the base material. The artificial leather of this embodiment is manufactured, for example, by laminating short fibers on one or both sides of the base material by a papermaking method, and then entangling the short fibers with each other and with the base material by an entanglement process. In this specification, "artificial leather" means an artificially manufactured leather-like sheet material.

[0012] Both the base material and the surface fiber layer contain plant fibers. Examples of plant fibers include natural cellulose fibers such as cotton, linen, ramie, hemp, pulp, bamboo, pineapple, banana, coconut, kapok, kenaf, and ginger lily.

[0013] The plant fiber content in the artificial leather of this embodiment is 50% by mass or more of the total mass of the artificial leather. The higher the plant fiber content, the lower the environmental burden during manufacturing and disposal, and furthermore, the high thermal conductivity of plant fibers results in a good tactile feel.

[0014] The artificial leather of this embodiment has a peel strength of 2 N / cm or more between the base material and the surface fiber layer, preferably 3 N / cm or more. When the peel strength is 2 N / cm or more, the entanglement strength between fibers is increased, so sufficient abrasion resistance is obtained to suppress surface damage in actual use even without resin coating, and flexibility is also increased.

[0015] To achieve a peel strength of 2 N / cm or more between the surface fiber layer and the substrate, it is preferable to adjust the type of short fibers and spun yarn used in the surface fiber layer and substrate, the length, thickness, and number of twists of the single fibers, the basis weight, thickness, and density of the surface fiber layer and substrate, and the processing conditions in the entanglement process. While methods such as water flow entanglement and needle punching are known for entanglement, water flow entanglement is preferred from the viewpoint of preventing damage to the substrate. In the case of water flow entanglement, the peel strength can be adjusted by adjusting the diameter of the nozzle that sprays the water, the water pressure of the sprayed water, and its direction. Furthermore, a binder resin can be added to improve the peel strength between the surface fiber layer and the substrate. To achieve a peel strength of 2 N / cm or higher, it is particularly important to implement water flow entanglement.

[0016] [Surface fiber layer] The L / D value, which is the ratio of the fiber length L to the single filament diameter D of the plant fibers contained in the surface fiber layer, is preferably 50 or more, more preferably 100 or more, and also preferably 4000 or less, more preferably 3000 or less, and even more preferably 2000 or less. When the L / D value is 50 or more and 4000 or less, the dispersibility and unfiber properties of the short fibers in the slurry when the short fibers are dispersed in water to prepare the slurry are good, the strength of the surface fiber layer is good, and pilling due to friction is less likely to occur. Furthermore, setting the range as described above is effective in ensuring that the peel strength between the surface fiber layer and the substrate is 2 N / cm or more.

[0017] The surface fiber layer preferably contains cellulose fibrils, from the viewpoint of increasing static friction and thereby enhancing inter-fiber entanglement. Here, cellulose fibrils refer to fibers or aggregates thereof, which are made from natural cellulose and have a fiber diameter of several hundred nanometers to several millimeters. Examples of cellulose fibrils include fibrillated cellulose. Examples of fibrillated cellulose include independent fibrils peeled from the fiber surface or fine fibers formed by the convergence of fibrils, obtained by micronizing plant-derived materials such as pulp using a device that applies a high shear force, such as a high-pressure homogenizer, an ultra-high-pressure homogenizer, or a grinder.

[0018] The specific surface area of the fibers constituting the surface fiber layer is preferably 0.10 m 2 / g or more, more preferably 0.20 m 2 / g or more, still more preferably 0.50 m 2 / g or more, most preferably 0.80 m 2 / g or more, and preferably 2.0 m 2 / g or less, more preferably 1.6 m 2 / g or less, still more preferably 1.2 m 2 / g or less. Here, the specific surface area of the fibers constituting the surface fiber layer is a value measured by the BET method.

[0019] The surface fiber layer preferably contains cellulose fibrils having a specific surface area of 0.5 m 2 / g or more and 1.5 m 2 / g or less. The specific surface area of the cellulose fibrils contained in the surface fiber layer is more preferably 0.6 m 2 / g or more and 1.0 m 2 / g or less, still more preferably 0.6 m 2 / g or more and 0.8 m 2 / g or less. The content of the cellulose fibrils having a specific surface area of 0.5 m 2 / g or more and 1.5 m 2 / g or less contained in the surface fiber layer is preferably 20% by mass or more, more preferably 50% by mass or more based on the total mass of the fibers contained in the surface fiber layer.

[0020] The surface fiber layer may contain synthetic fibers to improve mechanical properties such as tensile strength and flame retardancy. When the fiber layer contains synthetic fibers, it is preferable that the synthetic fiber content is 25% by mass or more and 50% by mass or less of the total mass of fibers contained in the surface fiber layer. If the synthetic fiber content is 25% by mass or more, the effects obtained by compounding with synthetic fibers will be fully realized, and if it is 50% by mass or less, the proportion of plant fibers will be sufficiently high, which will reduce the environmental burden during manufacturing and disposal, and the high thermal conductivity of plant fibers will result in a good tactile feel. Furthermore, by containing synthetic fibers with different dyeability from plant fibers, the surface fiber layer can achieve an excellent melange-like design due to the difference in dyeability. Examples of synthetic fibers that can be contained in the surface fiber layer include polyester, nylon 6, nylon 66, acrylic, polyurethane, and polylactic acid.

[0021] [Base material] The plant fiber content in the base material of the artificial leather of this embodiment is preferably 50% by mass or more relative to the total mass of the base material. More preferably, it is 60% by mass or more, and even more preferably 80% by mass or more. If the content is 50% by mass or more, the environmental burden during manufacturing and disposal is reduced, and the high thermal conductivity of plant fibers results in a good tactile feel. The base material may contain fibers other than plant fibers, preferably in an amount of 50% by mass or less relative to the total mass of the base material, for the purpose of improving mechanical properties such as tensile strength and flame retardancy. When the base material contains fibers other than plant fibers, for example, synthetic fibers such as polyester, nylon 6, nylon 66, acrylic, polyurethane, and polylactic acid, semi-synthetic fibers such as acetate, triacetate, and promix, regenerated fibers such as rayon, cupro, and lyocell, and inorganic fibers such as glass fibers and carbon fibers can be used. In particular, from the viewpoint of mechanical properties, the use of synthetic fibers is preferable.

[0022] The base material is not particularly limited as long as it is a fibrous fabric, and can be, for example, woven fabrics, knitted fabrics, and nonwoven fabrics. Furthermore, the fibers constituting the base material may be a single type or multiple types. For example, the base material may be a woven or knitted fabric using a composite spun yarn made from multiple types of short fibers, or a woven or knitted fabric using multiple types of spun yarns or filament yarns of different materials. From the viewpoint of achieving a peel strength of 2 N / cm or more between the surface fiber layer and the base material, the base material is preferably a woven fabric.

[0023] If the base material is a woven fabric, the following formula applies to the woven fabric:

number

[0024] [Binder resin] The artificial leather of this embodiment may contain a binder resin to further enhance the inter-fiber entanglement strength. On the other hand, if the artificial leather does not contain a binder resin, it has the advantage of achieving extremely high conformability to the shape of automobile interiors, furniture, etc. Therefore, it is possible to appropriately select whether or not to include a binder resin depending on the characteristics required for each application.

[0025] When artificial leather contains binder resin, the binder resin content is preferably more than 0% by mass and 20% by mass or less, and more preferably more than 0% by mass and 15% by mass or less, relative to the total mass of the artificial leather. If the binder resin content is 20% by mass or less, the flexibility of the artificial leather is sufficiently high while improving mechanical properties such as abrasion resistance and tensile strength, resulting in a good texture and good conformability to complex shapes such as those found in automobile interiors and furniture. Furthermore, from the viewpoint of strengthening the bonding strength between the fibers constituting the surface fiber layer, the binder resin content is preferably 5% by mass or more, and more preferably 8% by mass or more.

[0026] The type of binder resin is not particularly limited, but for example, acrylic resin, urethane resin, polyester resin, vinyl acetate resin, etc. can be used. From the viewpoint of achieving both flexibility and durability, urethane resin is preferred as the binder resin, and from the viewpoint of reducing environmental impact, water-dispersible urethane resin is particularly preferred.

[0027] [Other preferred embodiments of artificial leather] In this embodiment, the artificial leather has a surface unevenness height Sz that is preferably 200 μm or more and 600 μm or less, more preferably 500 μm or less, and even more preferably 450 μm or less, from the viewpoint of providing a smooth feel like suede or nubuck. When Sz is 200 μm or more, the surface has an appropriate unevenness, so a soft feel can be obtained. On the other hand, when Sz is 600 μm or less, the surface is less likely to have a rough feel.

[0028] To achieve a Sz of 200 μm to 600 μm, it is preferable that the surface is napped, and the Sz can be appropriately adjusted by the napping conditions, etc. Furthermore, the Sz can also be adjusted by the type of short fibers and spun yarn used in the surface fiber layer and base material, the length, thickness, and number of twists of the single fibers, the basis weight, thickness, and density of the surface fiber layer and base material, the type and amount of binder resin applied, and the processing conditions in the entanglement process.

[0029] The artificial leather of this embodiment is preferably dyed. As for the dyeing method, a liquid jet dyeing machine is preferred from the viewpoint of improving the texture.

[0030] The artificial leather of this embodiment can have a resin layer formed on its surface to improve abrasion resistance and flame retardancy. It can also be colored by mixing pigments into the resin layer. The method for forming the resin layer is not particularly limited and includes methods such as applying a resin solution in which resin is dissolved in a solvent and then drying the solvent to form the resin layer, applying a resin solution and then reacting the resin to form the layer (dry method), attaching a resin film made of synthetic resin (laminating method), and applying a resin solution and then guiding it to a solidification bath to solidify it (wet method).

[0031] [Interior covering material for vehicles] Another embodiment of the present invention is a vehicle interior surface material including the artificial leather described above. The vehicle interior surface material of this embodiment can be suitably used as a surface material to be attached to seats, door trims, instrument panels, ceilings, etc.

[0032] The vehicle interior surface material of this embodiment may have urethane foam laminated on its back surface to provide cushioning. Furthermore, embossing or embroidery may be applied for design and functionality. [Examples]

[0033] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the examples. The methods used to measure the various physical properties of the artificial leather used in the following examples were as follows.

[0034] (a) Peel strength between the fiber layer and the substrate (N / cm) Two rectangular samples, each measuring 2.5 cm on the short side and 10 cm on the long side, were cut from the artificial leather, with the long sides perpendicular to each other (referred to as Sample A and Sample B). 50 mg / cm² of ThreeBond 1521 synthetic rubber adhesive was then applied to the entire surface of both samples (the napped side in the case of napped artificial leather). 2 Apply the adhesive in the specified amount. Immediately after application, bond the adhesive-coated surfaces of the two samples together so that their long and short sides align. Compress the bonded samples with a mangle at 0.4 MPa, then leave them at 20°C and 50% RH for at least 5 hours. Cut 2.5 mm from both ends of the short side of the bonded samples with scissors to make them 2.0 cm (width) x 10 cm (length). Make an incision with a razor blade at the boundary between the substrate and the surface fiber layer of sample A from the short side, then peel the substrate and the surface fiber layer apart by about 2 cm with your fingers. Next, using an A&D Tensilon universal tester (model RTC-1210A), grip the substrate and the surface fiber layer with a gripping length of 2 cm each, pull at a crosshead speed of 100 mm / min and a recording paper speed of 50 mm / min to separate the substrate and the surface fiber layer, and measure the stress at that time. From the multiple peaks obtained in the stress-displacement chart, the peak values ​​of the three largest peaks (starting from the largest) and the three smallest peaks (starting from the smallest) are read, and the average value of these six points is calculated. Using the aforementioned bonded sample, a cut is made at the boundary between the substrate and the surface fiber layer of sample B, and the same measurement is performed again. The peel strength is calculated by dividing the average of the two obtained results by the sample width (2 cm).

[0035] (b) Coverage Factor CF The cover factor CF is given by the following formula:

number

[0036] (c) Plant fibers used as raw materials for the surface fiber layer, and the specific surface area (m²) of the fibers contained in the surface fiber layer 2 / g) The specific surface area was measured using an automatic specific surface area analyzer (Gemini2360, Shimadzu Corporation). The sample mass used for measurement was 0.20 to 0.60 g. The cell containing the sample was dried at 60°C for 30 minutes, followed by cooling for 10 minutes. Then, the cell was set in the above-mentioned specific surface area analyzer, and the specific surface area was measured by nitrogen gas adsorption onto the sample surface using the following BET formula: P / {V(P0-P)}=1 / (Vm×C)+{(C-1) / (Vm×C)}(P / P0) The specific surface area was calculated using the formula {wherein P: pressure, P0: saturated water vapor pressure (Pa), V: nitrogen adsorption amount (mg / g), Vm: monolayer adsorption amount (mg / g), and C: parameters related to heat of adsorption, etc. (-) < 0.}. The sample for measurement was prepared as follows.

[0037] <Plant fibers used as raw materials for the surface fiber layer> Using an aqueous dispersion of plant fibers, the procedure of centrifugation, removal of supernatant, and dilution with ethanol was repeated three times. Next, using the ethanol dispersion of plant fibers obtained above, the procedure of centrifugation, removal of supernatant, and dilution with t-butanol was repeated twice. Then, the t-butanol dispersion of plant fibers obtained above was centrifuged, the supernatant was removed, a small amount of t-butanol was added, and the mixture was freeze-dried to prepare a sample for measurement. <Fibers in the surface fiber layer> A sample for measurement was prepared by peeling off the surface fiber layer from artificial leather, and if the surface fiber layer had a binder resin and / or surface resin layer, dissolving and removing the binder resin and / or surface resin layer using a solvent that could dissolve the binder resin and / or surface resin layer but did not dissolve the fibers.

[0038] (d) Height of surface irregularities Sz of artificial leather Using a one-shot microscope (Keyence VR-3200), a sample of artificial leather measuring 15 cm square was observed and photographed at 40x magnification. To eliminate irregularities not originating from the surface fiber layer, the entire measurement range was specified, and surface shape correction (quadratic surface correction) was performed on the captured data. Then, the "Surface Roughness Measurement" function on the analysis screen was executed with the entire measurement range specified as the measurement area, and with the filter settings of low-pass filter: none, high-pass filter: none, to obtain the maximum height Sz. Ten measurements were taken by changing the measurement area within the sampled artificial leather, and the average value was taken as the result. In this measurement, if the artificial leather surface has deformation due to embossing or embroidery, 10 locations excluding the deformed areas were measured.

[0039] (e) Abrasion resistance JIS-L-1096 (2015 edition) 8.19 "Abrasion strength" (Method E: Martindale) In accordance with the law, an abrasion resistance test was conducted on the surface fiber layer of artificial leather under a pressing load (12 kPa). The relationship between the number of abrasion cycles and the exposed state of the base material was judged according to the following evaluation criteria, with ○ and ◎ being considered passing grades. ×: The substrate is exposed after 30,000 cycles. △: The substrate is not exposed after 30,000 cycles, but the scrim is exposed after 40,000 cycles. ○: The substrate is not exposed at 40,000 cycles, but the scrim is exposed at 50,000 cycles. ◎: The substrate is not exposed after 50,000 cycles.

[0040] (f)Flexibility Artificial leather samples, measuring 25cm square, were placed in a room at 20°C and 65% humidity for over 10 hours to allow for humidity control. Afterward, the feel of handling the samples in the same room was evaluated using the following criteria, determining their flexibility. The evaluation was done in 0.5 grade increments. Grade 5: Quite flexible Grade 4: Flexible Level 3: Somewhat flexible Level 2: Slightly hard Grade 1: Quite hard

[0041] (g)Tactile sensation Artificial leather samples, measuring 25 cm square, were placed in a room at 20°C and 65% humidity for over 10 hours to allow for humidity control. Afterward, the tactile sensation was evaluated by grading the sample surface with bare hands using the following criteria. The grading was done in 0.5-grade increments. Grade 5: Very pleasant to the touch Grade 4: Very good to the touch Grade 3: Good texture Grade 2: Slightly poor texture Grade 1: Poor texture

[0042] [Example 1] Fibrillated, with a specific surface area of ​​0.67 m². 2 A slurry for the surface fiber layer was prepared by mixing cotton staple fibers with a weight / g and L / D value of 250 with polyester staple fibers with a fiber length of 3 mm and a fiber diameter of 4 μm in a mass ratio of 70:30 and dispersing them in water. A fabric made of 20 count cotton / PET (65 / 35) spun yarn with a density of 55 threads / 2.54 cm warp and 60 threads / 2.54 cm weft was used as the base material, and a basis weight of 140 g / m² was applied to one side of the base material (hereinafter referred to as the "surface layer"). 2 To achieve this, the opposite side (hereinafter referred to as the "back layer") has a weight of 60g / m². 2 To achieve this, short fibers were deposited by papermaking using the slurry, and a nonwoven fabric sheet with a three-layer laminated structure was continuously manufactured. Next, a water stream was sprayed from the surface at a pressure of 4.0 MPa and from the back at a pressure of 3.0 MPa using a straight-flow spray nozzle with a pore diameter of 0.1 mm to perform entanglement treatment, and the sheets were dried in a pin tenter to obtain a basis weight of 330 g / m². 2A sheet was manufactured. The surface of this sheet was buffed with #400 sandpaper, and then the sheet was impregnated with an aqueous dispersion containing 9% by mass of polyether-based aqueous polyurethane resin and 3% by mass of Glauber's salt, such that the polyurethane resin adhesion rate was 14.3% by mass of the sheet's mass after impregnation. The sheet was then heated and dried in a pintenter dryer for 3 minutes to produce a raw material for artificial leather. This raw material was dyed black in a liquid flow dyeing machine to produce suede-like artificial leather.

[0043] [Example 2] Instead of cotton staple fibers, it has a specific surface area of ​​0.53 m². 2 Artificial leather was manufactured in the same manner as in Example 1, except that pineapple short fibers with a density of / g and an L / D value of 250 were used, a woven fabric consisting of 20-count pineapple fiber / PET(45 / 55) spun yarn with a density of 55 threads / 2.54cm in the warp and 60 threads / 2.54cm in the weft was used as the base material, and the sheet was impregnated so that the polyurethane resin adhesion rate was 4.1% by mass relative to the sheet mass after impregnation.

[0044] [Example 3] Specific surface area 0.67m 2 Instead of cotton staple fibers with a specific surface area of ​​1.42 m² / g and an L / D value of 250, use a different fiber. 2 Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with a density of / g and an L / D value of 250 were used, and that the fibers were not impregnated in an aqueous dispersion of water-based polyurethane resin.

[0045] [Example 4] In the manufacture of nonwoven fabric sheets, the surface weight is 100 g / m². 2 , and the basis weight of the backing layer is 35g / m 2 Artificial leather was manufactured in the same manner as in Example 1, except that the papermaking process was carried out in such a manner, and a solvent-based polyurethane resin was used instead of a water-based polyurethane resin, and the polyurethane resin was impregnated so that the adhesion rate of the polyurethane resin was 23.6% by mass relative to the sheet mass.

[0046] [Example 5] Specific surface area 0.67m 2Instead of cotton staple fibers with a specific surface area of ​​0.30 m² / g and an L / D value of 250, use a different fiber. 2 Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with a density of / g and an L / D value of 3500 were used.

[0047] [Example 6] Instead of cotton staple fibers, it has a specific surface area of ​​0.58 m². 2 Artificial leather was manufactured in the same manner as in Example 1, except that short wool fibers with a density of / g and an L / D value of 2500 were used.

[0048] [Example 7] As a slurry, it has a specific surface area of ​​0.67 m². 2 Artificial leather was manufactured in the same manner as in Example 1, except that a slurry was used in which only cotton staple fibers with a density of / g and an L / D value of 250 were dispersed in water, and a woven fabric made of 30-count cotton spun yarn with a density of 48 threads / 2.54cm in the warp and 50 threads / 2.54cm in the weft was used as the base material.

[0049] [Example 8] Artificial leather was manufactured in the same manner as in Example 1, except that the mixing ratio of cotton staple fibers to polyester staple fibers in the slurry was 35:65, and a fabric made of 20-count cotton spun yarn with a density of 55 threads / 2.54cm in the warp and 60 threads / 2.54cm in the weft was used as the base material.

[0050] [Example 9] Artificial leather was manufactured in the same manner as in Example 1, except that a fabric made of 30-count cotton / PET (65 / 35) spun yarn with a density of 35 threads / 2.54cm in the warp and 40 threads / 2.54cm in the weft was used as the base material.

[0051] [Example 10] The sheets were impregnated with polyurethane resin so that the adhesion rate was 6.6% by mass relative to the sheet mass, and instead of dyeing the raw material, a water-dispersible polyurethane resin containing pigment was applied to the surface of the raw material using a knife coater at a rate of 25 g / m². 2Artificial leather was manufactured in the same manner as in Example 1, except that the amount applied to the surface was specified.

[0052] [Example 11] Specific surface area 0.67m 2 Instead of cotton staple fibers of / g, a specific surface area of ​​0.15m² 2 Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with a weight of / g were used.

[0053] [Example 12] Specific surface area 0.67m 2 Instead of cotton staple fibers of / g, a specific surface area of ​​0.3m² 2 Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with a weight of / g were used.

[0054] [Example 13] Specific surface area 0.67m 2 Instead of cotton staple fibers at / g, a specific surface area of ​​1.8m² 2 Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with a weight of / g were used.

[0055] [Example 14] Artificial leather was manufactured in the same manner as in Example 1, except that cotton staple fibers with an L / D value of 80 were used instead of cotton staple fibers with an L / D value of 250.

[0056] [Comparative Example 1] Using the same slurry as in Example 1, the basis weight was 200 g / m². 2To achieve this, single-layer nonwoven fabric sheets were continuously manufactured by papermaking. Next, a water stream was sprayed from the surface at a pressure of 4.0 MPa and from the back at a pressure of 3.0 MPa using a straight-flow spray nozzle with a pore diameter of 0.1 mm to perform entanglement treatment, and the sheets were dried in a pin tenter to produce sheets. The surface of these sheets was buffed with #400 sandpaper, and then the sheets were impregnated in a solvent-based polyurethane resin solution so that the polyurethane resin adhesion rate was 40% by mass relative to the sheet mass after impregnation, and the sheets were heated and dried in a pin tenter dryer for 3 minutes to produce artificial leather raw material. On the surface of the raw material, a solvent-based polyurethane resin containing pigment was applied at a rate of 25 g / m² using a knife coater. 2 The material was applied to the surface in the specified amount to produce artificial leather.

[0057] [Comparative Example 2] Artificial leather was manufactured in the same manner as in Comparative Example 1, except that the adhesion rate of the solvent-based polyurethane was set to 4.8% by mass relative to the sheet mass after impregnation, and that instead of applying a solvent-based polyurethane resin containing pigment to the surface, the raw material was dyed black using a liquid flow dyeing machine.

[0058] [Comparative Example 3] Artificial leather was manufactured in the same manner as in Example 1, except that the mixing ratio of cotton staple fibers to polyester staple fibers in the slurry was set to 35:65, and a fabric made of 20-count polyester spun yarn with a density of 55 threads / 2.54cm in the warp and 60 threads / 2.54cm in the weft was used as the base material.

[0059] The various physical properties and evaluation results of the artificial leather produced in the above examples and comparative examples are shown in Tables 1 to 3 below.

[0060] [Table 1]

[0061] [Table 2]

[0062] [Table 3] [Industrial applicability]

[0063] The present invention is an artificial leather that contains a large amount of plant fibers and achieves both softness and abrasion resistance, and can therefore be widely used in applications such as furniture, clothing, the automotive industry, shoes, and bags, and is particularly suitable for use as a surface material for vehicle interiors.

Claims

1. Artificial leather comprising a woven base material and a surface fiber layer laminated on the base material, characterized by the following features (1) to (3): (1) The base material and the surface fiber layer both contain plant fibers; (2) The plant fiber content in the artificial leather is 50% by mass or more of the total mass of the artificial leather; and (3) The peel strength between the substrate and the surface fiber layer is 2 N / cm or more; Artificial leather that satisfies the above conditions, and whose L / D value, which is the ratio of the fiber length L to the single filament diameter D of the plant fibers contained in the surface fiber layer, is 50 or more and 4000 or less.

2. Artificial leather comprising a woven base material and a surface fiber layer laminated on the base material, characterized by the following features (1) to (3): (1) The base material and the surface fiber layer both contain plant fibers; (2) The plant fiber content in the artificial leather is 50% by mass or more of the total mass of the artificial leather; and (3) The peel strength between the substrate and the surface fiber layer is 2 N / cm or more; The following conditions are satisfied, and the specific surface area of ​​the fibers constituting the surface fiber layer is 0.10 m². ２ Artificial leather with a weight of 1g or more.

3. The artificial leather according to claim 1 or 2, wherein the plant fiber content in the base material is 50% by mass or more relative to the total mass of the base material.

4. The artificial leather according to claim 1 or 2, wherein the artificial leather contains a binder resin.

5. The artificial leather according to claim 4, wherein the content of the binder resin is greater than 0% by mass and greater than 20% by mass with respect to the total mass of the artificial leather.

6. The artificial leather according to claim 4, wherein the binder resin is a polyurethane resin.

7. The artificial leather according to claim 6, wherein the polyurethane resin is a water-dispersible polyurethane resin.

8. The artificial leather according to claim 1 or 2, wherein the surface fiber layer comprises cellulose fibril.

9. Furthermore, the following feature (4): (4) The surface fiber layer has a specific surface area of ​​0.5 m² ２ / g or more 1.5m ２ Contains cellulose fibrils of less than / g; Artificial leather according to claim 1 or 2, which satisfies the condition.

10. The artificial leather according to claim 1 or 2, wherein the cover factor CF of the fabric is 15 or more and 40 or less.

11. The artificial leather according to claim 1 or 2, wherein the height Sz of the surface irregularities of the artificial leather is 200 μm or more and 600 μm or less.

12. The artificial leather according to claim 1 or 2, wherein the surface of the artificial leather is napped.

13. The artificial leather according to claim 1 or 2, wherein the artificial leather is dyed.

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