Three-dimensional knitted fabric

Abstract

Provided is a three-dimensional knitted fabric achieving high durability and the like. The present invention relates to a three-dimensional knitted fabric, a skin material comprising the three-dimensional knitted fabric, a vehicle using the skin material as an interior material, a method for using the three-dimensional knitted fabric, and a method for producing the three-dimensional knitted fabric, the three-dimensional knitted fabric comprising a knitted fabric of a surface layer, a knitted fabric of a back layer, and a connecting yarn that connects the knitted fabric of the surface layer and the knitted fabric of the back layer, and the three-dimensional knitted fabric being characterized by containing 90 mass% or more of polyester and having a hard finish agent on a fiber surface constituting the knitted fabric of the surface layer of the three-dimensional knitted fabric, the maximum stress at 50% compression of the three-dimensional knitted fabric being 500 gf / cm2 or less, and by satisfying formulas (1)-(3) ((1): E1 ≥ 3.0; (2): E2 ≥ 1.0; (3): E1 - E2 ≥ 1.0. [In the formulas, E1 is an abrasion resistance grade based on Taber abrasion of the surface layer surface of the three-dimensional knitted fabric, and E2 is an abrasion resistance grade based on Taber abrasion of the back layer surface of the three-dimensional knitted fabric.]).

Description

3D knitting

[0001] The present invention relates to a three-dimensional knitted fabric, a skin material, a vehicle, and a method for manufacturing the three-dimensional knitted fabric.

[0002] Conventionally, three-dimensional knitted fabrics consisting of two layers of knitted fabric, one on the front side and one on the back side, and a connecting yarn connecting the two layers of knitted fabric have cushioning properties in the thickness direction due to the use of monofilament as the connecting yarn, and further, the knitted fabrics on the front and back sides have a mesh structure to ensure high breathability, so that they are widely used as cool, stuffy-preventing cushioning materials for applications such as seat covers and bedding.

[0003] On the other hand, when three-dimensional knitted fabrics are used as covering materials for seats of vehicles or furniture, or for interior materials of vehicles, high breathability is achieved, but there is room for improvement in durability such as surface abrasion resistance required for covering materials.

[0004] The following Patent Document 1 discloses a three-dimensional knitted fabric for seats that has a surface texture and a soft elastic feel, is highly abrasion-resistant, and shows little change in appearance even after long-term use, by setting the opening rate, stitch density, surface elongation rate, convergence degree of the multi-yarn used in the front knitted fabric, and compression characteristics of the three-dimensional knitted fabric within specific ranges.

[0005] Furthermore, Patent Document 2 below discloses a technique for hardening a three-dimensional knitted fabric using a thermosetting resin or the like when the three-dimensional knitted fabric is used as a sheet for civil engineering work, thereby improving the mechanical strength, and in particular the abrasion resistance and dimensional stability.

[0006] JP 2004-229894 A JP 2008-223152 A

[0007] In Patent Document 1, soft elasticity and durability are achieved by focusing on the yarn and stitch density used in the surface layer of the three-dimensional knitted fabric. However, the abrasion resistance of the fabric measured a grade 3-4 level in the Taber abrasion test after 1,000 abrasions at a low load (4.9 N), which does not meet the standards for skin materials that require high abrasion resistance. In Patent Document 2, mechanical strength is imparted to the three-dimensional knitted fabric by resin processing. Although an equivalent evaluation method for abrasion resistance is not used, high abrasion resistance is estimated based on dimensional stability, etc., but the shape is fixed by the resin processing, making the three-dimensional knitted fabric less susceptible to deformation and resulting in significantly poor cushioning. Interior skin materials face a variety of requirements, including those related to functionality and design, and in particular, a balance between surface abrasion resistance and cushioning is required. These two requirements are contradictory, and no technology has yet been disclosed that satisfies both requirements.

[0008] Under such a state of the art, the problem to be solved by the present invention is to provide a three-dimensional knitted fabric that has both excellent surface abrasion resistance and cushioning properties.

[0009] As a result of extensive research and experimentation to solve the above-mentioned problems, the inventors unexpectedly discovered that the above-mentioned problems could be solved by adjusting the abrasion resistance grade of the front surface (surface layer surface) and the back surface (inner surface) of the three-dimensional knit fabric to a specific range and specific relationship by changing the structure of the three-dimensional knit fabric and applying a hard finishing agent, and thus completed the present invention.

[0010] That is, the present invention is as follows: [1] A three-dimensional knitted fabric including a knitted fabric of a surface layer, a knitted fabric of a back layer, and a connecting yarn connecting the knitted fabric of the surface layer and the knitted fabric of the back layer, wherein the three-dimensional knitted fabric contains 90% by mass or more of polyester, a hard finishing agent is applied to the surface of the fibers constituting the knitted fabric of the surface layer of the three-dimensional knitted fabric, and the maximum stress of the three-dimensional knitted fabric when compressed by 50% is 500 gf / cm ２

[0023] A three-dimensional knitted fabric characterized in that the three-dimensional knitting agent is a polyester-based hard finishing agent or a polyurethane-based hard finishing agent, and the three-dimensional knitted fabric satisfies the following formulas (1) to (3): E1≧3.0 (1) E2≧1.0 (2) E1−E2≧1.0 (3) {wherein E1 is the abrasion resistance grade of the front layer surface of the three-dimensional knitted fabric by Taber abrasion, and E2 is the abrasion resistance grade of the back layer surface of the three-dimensional knitted fabric by Taber abrasion.} [2] The three-dimensional knitted fabric according to [1] above, wherein the hard finishing agent is a polyester-based hard finishing agent or a polyurethane-based hard finishing agent. [3] The three-dimensional knitted fabric according to [1] above, wherein the air permeability from the back layer knitted fabric to the front layer knitted fabric is 50 cm ３ / (cm ２ sec) or more. [4] The three-dimensional knit fabric according to any one of [1] to [3], wherein the amount of application of the hard finishing agent is 0.5% by mass to 10% by mass, relative to 100% by mass of the entire three-dimensional knit fabric. [5] The three-dimensional knit fabric according to any one of [1] to [4], wherein only the knitted fabric of the surface layer has a hard finishing agent. [6] A covering material made of the three-dimensional knit fabric according to any one of [1] to [5]. [7] A vehicle in which the covering material according to [6] is used as an interior material. [8] A method of using the three-dimensional knit fabric according to any one of [1] to [5] as a covering material, wherein the knitted fabric of the surface layer of the three-dimensional knit fabric is used as the outermost surface of the covering material. [9] A method for producing a three-dimensional knitted fabric according to any one of [1] to [5], comprising the following steps: applying a hard finishing agent solution having a concentration of 5% by mass to 40% by mass to the surface of the outer layer of the three-dimensional knitted fabric so that the amount of the solution applied is within the range of 5% by mass to 30% by mass based on the entire three-dimensional knitted fabric.

[10] A method for producing a three-dimensional knitted fabric according to [9], in which a hard finishing agent is not applied to the knitted fabric of the back layer of the three-dimensional knitted fabric.

[0011] According to the present invention, it is possible to provide a three-dimensional knitted fabric that has practical breathability and flexibility, as well as excellent durability and cushioning properties.

[0012] FIG. 10 is a diagram showing the press mold design (concave deformation portion) used in Example 4.

[0013] Hereinafter, an embodiment of the present invention will be described in detail. One embodiment of the present invention is a three-dimensional knitted fabric including a knitted fabric of a surface layer, a knitted fabric of a back layer, and a connecting yarn connecting the knitted fabric of the surface layer and the knitted fabric of the back layer, wherein the three-dimensional knitted fabric contains 90% by mass or more of polyester, a hard finishing agent is applied to the surface of the fiber constituting the knitted fabric of the surface layer of the three-dimensional knitted fabric, and the maximum stress of the three-dimensional knitted fabric when compressed by 50% is 500 gf / cm ２ and satisfying the following formulas (1) to (3): E1≧3.0 (1) E2≧1.0 (2) E1−E2≧1.0 (3) {where E1 is the abrasion resistance grade by Taber abrasion of the front layer surface of the three-dimensional knit fabric, and E2 is the abrasion resistance grade by Taber abrasion of the back layer surface of the three-dimensional knit fabric.}

[0014] Here, "maximum stress at 50% compression" refers to the maximum stress when a three-dimensional knitted fabric is compressed in the thickness direction until it is reduced to 50% of its original thickness (hereinafter also referred to as "compressive stress"). The compressive stress can be determined, for example, by using a compression tester to compress a three-dimensional knitted fabric sample placed on a smooth rigid surface at a constant speed with a disk-shaped compression jig until it is reduced to 50% of its original thickness.

[0015] The compressive stress of the three-dimensional knitted fabric of this embodiment is mainly affected by the connecting yarns used in the three-dimensional knitted fabric. The more thick the yarns used, the higher the compressive stress can be, and the more dramatically the compressive stress increases when a hard finishing agent is applied to the connecting yarns. However, the compressive stress should be 500 gf / cm from the viewpoint of cushioning when sitting. ２ Furthermore, the connecting yarn is important in order to prevent the user from feeling like they are hitting the bottom when sitting down. By adjusting the elasticity and amount of the yarn, it is possible to achieve a value of 200 to 450 gf / cm ２ It is preferable that the range is 250 to 400 gf / cm ２ When a hard finishing agent is applied to the connecting yarn portion of a three-dimensional knitted fabric, the compressive stress of the three-dimensional knitted fabric increases. ２ To achieve the above, it is preferable to reduce the amount of hard finishing agent applied to the connecting yarn portion, or not to apply hard finishing agent to the connecting yarn portion.

[0016] The "Taber abrasion resistance grade" refers to the grade of the abrasion state determined after an abrasion test on the surface of a three-dimensional knitted fabric. The abrasion resistance grade can be determined, for example, in accordance with ASTM 3884-9 (rotating platform double-head method), by performing an abrasion test 1,000 times using a CS-10 abrasion wheel at a load of 1,000 g and a speed of 72 rpm, and then observing the abrasion state of the surface of the test piece, and determining the abrasion state in accordance with JASO M403 A method.

[0017] The abrasion resistance grade E1 of the front surface of the three-dimensional knitted fabric (i.e., the outer layer surface of the three-dimensional knitted fabric) is 3.0 or more from the viewpoint of durability. In particular, the E1 is preferably 3.5 or more, and more preferably 4.0 or more.

[0018] The abrasion resistance grade E2 of the back surface of the three-dimensional knitted fabric (i.e., the back surface of the three-dimensional knitted fabric) is 1.0 or more in order to ensure abrasion resistance and ease of handling, even if it is not as high as that of the front surface of the three-dimensional knitted fabric. Furthermore, from the viewpoint of conformability and smoothness to the shape of the substrate placed underneath, it is preferable that the E2 be in the range of 1.5 to 2.0.

[0019] In the three-dimensional knitted fabric, the difference between E1 and E2 (i.e., E1-E2) in terms of cushioning comfort when sitting is 1.0 or more. In particular, the difference is preferably more than 1.0, more preferably 1.5 or more, and even more preferably 2.0 or more. There is no particular upper limit to the difference (E1-E2), but it can be 3.0 or less.

[0020] E1 and E2 can be adjusted appropriately, for example, by adjusting the stitch density, the amount of hard finishing agent applied, or both, as described below. Although this depends on the knitting pattern, the higher the stitch density, the more likely E1 and E2 will increase. Furthermore, the greater the amount of hard finishing agent applied, the higher E1 and E2 will increase. However, to make the difference (E1 - E2) 1.0 or greater, it is preferable to apply more hard finishing agent to the front knitted fabric than to the back knitted fabric, or to apply hard finishing agent only to the front knitted fabric.

[0021] The three-dimensional knit fabric of this embodiment is composed of a knitted fabric for the front layer, a knitted fabric for the back layer, and a connecting yarn (hereinafter also referred to as the "connecting layer") connecting the two knitted fabrics, and contains 90% by mass or more of polyester. Specific examples of the polyester include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid (PLA), polyethylene naphthalate (PEN), etc. The polyester content is 90% by mass or more, preferably 95% by mass or more, and more preferably 98% by mass or more.

[0022] The polyester may be a copolymer polyester containing one or more third components in its molecular structure. Examples of the third components include aliphatic dicarboxylic acids (such as oxalic acid and adipic acid), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (such as isophthalic acid and sodium sulfoisophthalic acid), aliphatic glycols (such as ethylene glycol, propylene glycol, and tetramethylene glycol), alicyclic glycols (such as cyclohexanediol), aromatic dioxy compounds, aromatic aliphatic glycols, polyether glycols, and even aliphatic oxycarboxylic acids and aromatic oxycarboxylic acids. From the perspective of ease of recycling, such as material recycling and chemical recycling, it is preferable that the polyester does not contain the third component.

[0023] The fibers constituting the three-dimensional knitted fabric of this embodiment may be a composite of various fiber materials, but from the viewpoint of recyclability, it is preferable that the knitted fabric of the surface layer, the connecting yarn, and the knitted fabric of the back layer are all 100% PET fiber. These fibers may be undyed, but it is preferable to use dope-dyed yarns or pre-dyed yarns in order to suppress fluctuations in the properties of the three-dimensional knitted fabric during dyeing processing. Furthermore, it is more preferable to use dope-dyed yarns kneaded with pigments or the like, which can eliminate the need for a dyeing process.

[0024] The fiber material used for the knitted fabric of the front or back layer is not limited, and may be a single material or a composite of multiple materials by blending, plying, blending, interweaving, etc., but from the viewpoints of raw yarn strength and light resistance, long PET fibers are preferably used. Furthermore, from the viewpoint of increasing the pull-out resistance of single fibers so that they are less likely to be pulled out from the knitted fabric surface by protrusions such as hooks of a hook-and-loop fastener, the PET fiber is preferably a false twisted yarn, an interlaced yarn, or a twisted yarn.

[0025] The fineness of the fibers used in the knitted fabric of the front or back layer is preferably in the range of 100 to 350 dtex, for example, in order to optimize the stitch density described below. From the same viewpoint, the total fineness of one stitch made of fibers forming the knitted fabric of the front layer is preferably in the range of 150 to 800 dtex, for example. When the fibers used in the knitted fabric of the front or back layer are multifilament, the single yarn fineness is preferably in the range of 1 to 6 dtex, but a range of 3 to 6 dtex, for example, is more preferable, as this increases the strength of the single yarn.

[0026] The fiber used for the connecting yarn is preferably a monofilament. When a monofilament is used for the connecting yarn, the fineness thereof is preferably within the range of, for example, 30 to 300 dtex, more preferably within the range of 50 to 250 dtex, in order to suppress protrusion of the monofilament onto the knitted fabric surface and maintain good cushioning properties.

[0027] If a monofilament protrudes from the surface of the three-dimensional knitted fabric, it will easily get caught on protrusions such as the hook portion of a hook-and-loop fastener. Therefore, it is preferable that the stitches of the fibers forming the surface knitted fabric press down the stitches of the monofilament so that the monofilament does not protrude from the outer surface of the surface knitted fabric (i.e., the seating surface of the seat cover material).To achieve this, it is preferable that the fineness D2 (dtex) of the monofilament satisfies the following relationship: D1 / D2≧3.

[0028] The thickness of the three-dimensional knit fabric of this embodiment varies as desired and can be set arbitrarily without any particular restrictions. From the viewpoints of sewability, handling, and cushioning properties as a skin material, the thickness is preferably within the range of 3 to 12 mm, and more preferably within the range of 3 to 8 mm. If the thickness is less than 3 mm, the cushioning properties may be deteriorated, and if it is greater than 12 mm, problems may arise, for example, with regard to sewability and handling properties.

[0029] The weight of the three-dimensional knitted fabric of this embodiment is not particularly limited and can be set arbitrarily, but is preferably 400 to 1000 g / m ２ in the range of 500 to 900 g / m ２ The basis weight is within the range of 400 g / m ２ If it is smaller than this, the durability may decrease, and ２ If it is larger, the cushioning effect may be reduced.

[0030] The stitch density of the knitted fabrics of the front and back layers is not particularly limited as long as it has the technical characteristics of the above formulas (1) to (3), but it is suitable to be in the range of 500 to 25,000. In particular, from the viewpoint of abrasion resistance, it is preferable that the stitch density of the front layer is in the range of 11,500 to 20,000, and from the viewpoint of flexibility, it is preferable that the stitch density of the back layer is in the range of 500 to 11,500, and it is more preferable that the stitch density of the front layer is in the range of 14,000 to 19,000, and the stitch density of the back layer is in the range of 750 to 9,000.

[0031] Here, the "mesh density" refers to the density of the mesh per square inch (2.54 cm) ２ ] is the number of stitches of the knitted fabric per stitch, and D is the total fineness (dtex) of the fibers per stitch of the knitted fabric, and M is an index M expressed as M = N × √D. The stitch density M is a measure of the density of the stitches of the knitted fabric.

[0032] The three-dimensional knit fabric of this embodiment has a hardening agent applied to at least the surface of the front layer. The hardening agent may also be applied to the back layer, but it is preferably applied only to the surface of the front layer. Examples of such hardening agents include ester-based hardening agents, urethane-based hardening agents, and acrylic-based hardening agents. Of these, ester-based hardening agents are preferred. From the standpoint of recyclability, it is preferable to use a hardening agent made of the same type of material as the fibers that make up the three-dimensional knit fabric, and to make the three-dimensional knit fabric as a whole a mono-material fabric.

[0033] Examples of the main component of the ester-based hard finishing agent (e.g., a component comprising 50% by mass or more or the component with the highest content; the same applies hereinafter) include ester compounds obtained by the dehydration condensation reaction of a diol component such as ethylene glycol, propylene glycol, 1,3-propanediol, or 1,4-butanediol with a dicarboxylic acid component such as terephthalic acid, isophthalic acid, or phthalic acid, or an anhydride or ester-forming derivative of a dicarboxylic acid. Two or more of these compounds can also be copolymerized. Furthermore, the ester compounds can be used alone or in combination.

[0034] The main component of the polyurethane-based hard finishing agent can be, for example, a polyurethane resin containing a chain-extended product of a neutralized isocyanate-terminated prepolymer, which is a reaction product of an organic polyisocyanate, a polyol, and a polyhydric alcohol, with a polyamine having two or more amino and / or imino groups.

[0035] The amount of the hardening agent applied (the amount applied to the three-dimensional knit fabric of this embodiment) varies depending on the type of hardening agent used and the desired physical properties, and is not particularly limited, but is, for example, in the range of 0.5% to 10% by mass, preferably 0.5% to 5% by mass. If the amount applied is 0.5% by mass or more, the desired abrasion resistance effect is obtained, while if it is 10% by mass or less, good cushioning properties are obtained.

[0036] Furthermore, the ratio of the amount of hard finishing agent applied to the surface layer to the amount applied to the entire three-dimensional knitted fabric is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. This ratio can be calculated by cutting the three-dimensional knitted fabric at the connecting layer, pulling out the connecting yarns knitted into the surface layer, separating the surface layer from the other parts (back layer and connecting layer), and quantifying the amount of hard finishing agent contained in each. The method for quantifying the hard finishing agent can be selected appropriately depending on its properties, but examples include a method in which the hard finishing agent is extracted from the three-dimensional knitted fabric using a solvent, and then the solvent is evaporated and the weight of the residue obtained is measured.

[0037] The three-dimensional knit fabric of this embodiment may further contain additives. Examples of such additives include matting agents (e.g., titanium dioxide), stabilizers (e.g., phosphoric acid), crystallization nucleating agents (e.g., talc), lubricants (e.g., Aerosil), antioxidants (e.g., hindered phenol derivatives), flame retardants, antistatic agents, fluorescent brighteners, ultraviolet absorbers, infrared absorbers, and antifoaming agents. From the perspective of recyclability, it is preferable that such additives are not included.

[0038] The three-dimensional knit fabric of this embodiment is less likely to produce fiber waste on the cut surface after being cut into a predetermined shape. In a three-dimensional knit fabric in which loops are knitted by intertwining them in the warp or weft direction, the fibers that make up the loops are cut along the way, resulting in fiber scraps on the cut surface of the base fabric layer, or fraying from the fiber scraps throughout the fibers of the base fabric layer, generating fiber waste. If the fiber waste is fine, it will stick to the surface of the skin material and remain, causing poor appearance of the skin material. Furthermore, if it is thick, it will deteriorate the feel when touched and lead to contamination of subsequent processes. Therefore, it is preferable that the fiber waste during cutting be less than 10 mg per meter of cut length, and it is most preferable that no cutting waste is generated.

[0039] Another embodiment of the present invention is a method for producing the three-dimensional knitted fabric, comprising the following steps: applying a hard finishing agent solution having a concentration of 5% by mass to 40% by mass to the surface of the outer layer of the three-dimensional knitted fabric, so that the amount of the solution applied is within the range of 5% by mass to 30% by mass based on the entire three-dimensional knitted fabric.

[0040] The three-dimensional knitted fabric of this embodiment can be produced using an appropriate knitting machine, such as a double Russell knitting machine equipped with multiple reeds that can be allocated to each of the front, connecting, and back layers. It is preferable to allocate at least two reeds to each layer. The three-dimensional knitted fabric or its grey fabric of this embodiment can be knitted by supplying yarn in an appropriate arrangement from the reed that forms the front layer fabric, the reed that forms the connecting layer, and the reed that forms the back layer fabric. There are no particular restrictions on the gauge of the knitting machine, but a gauge in the range of 14 to 28 can be preferably used, for example. The on-machine courses, knitting structure, etc. can be appropriately set so that the knitted three-dimensional knitted fabric or its finished product satisfies the above-mentioned technical characteristics of the three-dimensional knitted fabric of this embodiment.

[0041] By applying a hardening agent to the three-dimensional knit fabric of this embodiment, the abrasion resistance of the surface of the three-dimensional knit fabric is increased, essentially imparting durability sufficient for use in car seats, etc. While one method for increasing abrasion resistance involves agents that impart slipperiness and slidability to enhance durability, a material that is applied to the surface of the three-dimensional knit fabric to harden the surface layer and enhance durability is preferred from the perspective of a car seat covering material where a person sits and maintains their posture. However, interior covering materials are required not only to be durable but also to have functionality and design, such as breathability, feel, and cushioning, and it is particularly necessary to enhance durability without compromising cushioning.

[0042] The hardening agent can be applied using a hardening agent containing, for example, a water-soluble or water-dispersible resin as the main component, such as a water-soluble or water-dispersible polyester resin, polyurethane resin, or acrylic resin.

[0043] Depending on the concentration and amount of the agent to be applied, an appropriate amount of the hardening agent solution is applied to the appropriate location of the three-dimensional knit fabric using a roll coater, gravure coater, comma coater, kiss coater, bar coater, spin coater, impregnation, curtain coater, dispenser, spray, foam processing, etc. From the perspective of durability, it is preferable to apply the hardening agent to the entire three-dimensional knit fabric using impregnation or a curtain coater. From the perspective of satisfying the maximum stress and abrasion resistance grade at 50% compression specified in this embodiment and achieving both surface abrasion resistance and cushioning, it is preferable to apply the hardening agent only to the surface layer of the three-dimensional knit fabric. Specifically, it is preferable to apply the hardening agent only to the surface layer of the three-dimensional knit fabric using a method that can apply it from the surface layer of the three-dimensional knit fabric, such as a gravure coater, kiss coater, spin coater, spray, or foam processing. Applying the hardening agent to the connecting yarn portion or back layer portion of the three-dimensional knit fabric may increase the maximum stress and rigidity of the three-dimensional knit fabric more than necessary, and may reduce breathability, thereby compromising comfort such as cushioning. After application, it is appropriate to dry the fabric using, for example, a pin tenter, roll heating, etc. If the surface layer of the three-dimensional knit fabric to which the hardening agent has been applied is placed downward during drying, the spread of the hardening agent onto the connecting yarns, etc. during drying can be minimized, and the maximum stress and abrasion resistance grade at 50% compression specified in this embodiment will be satisfied, tending to improve only the abrasion resistance while maintaining cushioning properties.

[0044] The concentration of the hard finish solution is not particularly limited as long as it does not interfere with application, but is preferably in the range of 5% to 40% by mass. A concentration of 5% by mass or more tends to shorten the drying time after application, while a concentration of 40% by mass or less tends to allow the solution viscosity to be adjusted to an appropriate range, resulting in good application properties. The concentration of the hard finish solution is more preferably in the range of 10% to 20% by mass.

[0045] The solution viscosity of the hard finishing agent solution is preferably in the range of 10 mPa·s to 10,000 mPa·s. When the viscosity is 10 mPa·s or more, when applied to the surface layer of the three-dimensional knitted fabric, it is less likely to spread to the connecting yarns or back layer, and it tends to be easier to apply only to the surface layer. When the viscosity is 10,000 mPa·s or less, the application method is not limited and it tends to be possible to apply a small amount. More preferably, it is in the range of 50 mPa·s to 5,000 mPa·s.

[0046] The amount of hard finish solution applied varies depending on the type of hard finish used and the desired physical properties, and is not particularly limited, but is preferably within the range of 5% to 30% by mass based on the entire three-dimensional knit fabric. If the application amount is 5% by mass or more, it tends to be easier to adjust the desired hard finish application amount, and abrasion resistance tends to be more consistently achieved. On the other hand, if the application amount is 30% by mass or less, when applied to the surface layer of the three-dimensional knit fabric, it tends to be less likely to spread to the connecting yarns and back layer, making it easier to apply only to the surface layer, and also tends to make it easier to appropriately adjust the load in the drying process. The application amount of hard finish solution is more preferably within the range of 5% to 20% by mass based on the entire three-dimensional knit fabric.

[0047] In the finishing process of the three-dimensional knitted fabric of this embodiment, in the case of a three-dimensional knitted fabric using yarn-dyed or spun-dyed yarn, the grey fabric can be finished through processes such as scouring and heat setting, but in terms of simplifying the process, it is preferable to finish by heat setting only. In the case of a three-dimensional knitted fabric in which either the connecting yarn or the fiber used in the front and back two-layer knitted fabric is uncolored, the grey fabric can be finished through processes such as presetting, scouring, dyeing, and heat setting. Furthermore, surface treatments such as embroidery, heat embossing, electric welding, and high-frequency welding can also be performed as necessary.

[0048] In the three-dimensional knitted fabric of this embodiment, after all knitting and finishing processes are completed, the air permeability from the back layer knitted fabric to the front layer knitted fabric is 50 cm or less, as measured by the measurement method described later. ３ / (cm ２sec) or more. Three-dimensional knitted fabrics with low breathability tend to lack flexibility in compression and bending deformation, and are inferior in heat transfer and moisture release as fabrics, resulting in poor properties in various applications. In particular, the application of a hard finishing agent has a large effect on breathability, and if the hard finishing agent is applied in layers to the surface knitted fabric or applied so much that it restricts the movement of the connecting yarns, the breathability will drop significantly. The breathability is preferably 60 cm ３ / (cm ２ sec) or more, more preferably 80 cm ３ / (cm ２ ·sec) or more.

[0049] The three-dimensional knitted fabric of this embodiment can be used, for example, as a skin material or an interior material. Examples of objects to which it can be stretched include seat frames, cushion members, door trims, ceilings, armrests, instrument panels, and carpets of vehicles (cars, airplanes, etc.) and furniture (including office chairs, etc.).

[0050] Another embodiment of the present invention is a method for using the three-dimensional knitted fabric as a skin material, characterized in that the knitted fabric of the surface layer of the three-dimensional knitted fabric is used as the outermost surface of the skin material. Here, the outermost surface means the surface that is touched by people or exposed to the outside air.

[0051] The three-dimensional knit fabric of this embodiment can be laminated with urethane on the backside of the seating surface, as in conventional seat covering materials, but it is preferable to use it without lamination in terms of recyclability. The seat covering material may be composed of the three-dimensional knit fabric of this embodiment alone, or may be combined with other materials by sewing or the like in terms of design and functionality.

[0052] 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 following examples. First, the methods for measuring various physical properties of the three-dimensional knitted fabrics used in the examples will be described below.

[0053] (a) Thickness (mm) This was measured in accordance with JIS L 1913 Method B. The thickness was measured at three or more points under a load of 0.02 kPa, and the average value was calculated.

[0054] (b) Weight (g / m２ The weight per unit area of ​​the three-dimensional knitted fabric was measured in accordance with JIS L 1913.

[0055] (c) Percentage (%) of the amount of hard finish applied to the surface layer relative to the total amount applied. The three-dimensional knitted fabric was cut into squares with sides 1 inch long using a laser cutter, which were then cut at the connecting layer. The connecting threads woven into the surface layer were then pulled out to separate the surface layer from the other parts (back layer and connecting layer). Next, the separated surface layer and other parts were each subjected to a Soxhlet extraction apparatus to dissolve and remove the applied hard finish. The solvent used for Soxhlet extraction was selected depending on the hard finish used and the fiber material used in the three-dimensional knitted fabric. The hard finish was extracted using the Soxhlet extraction apparatus for more than 8 hours, and then the extraction solvents were distilled off and the weight of the resulting residue was measured. The weight of the measured residue was used to calculate the ratio (%) of the amount of hard finishing agent applied to the surface layer to the total amount applied = [(weight (mg) of residue extracted from the surface layer / {total weight (mg) of residue extracted from the surface layer and other areas (back layer and connecting layer)}] × 100.

[0056] (d) Air permeability (cm ３ / (cm ２ sec)) Using a breathability tester FX3300 Lab Air IV manufactured by Takayama Reed Co., Ltd., a test piece size of 15 cm square was placed on the opening of the breathability tester with the surface knitted fabric of a three-dimensional knitted fabric facing downwards, and a 3 mm thick, 20 cm square silicone rubber plate was placed on the outer surface of the back knitted fabric, and the test head of the breathability tester was pressed against it and fixed with a clamp, and under suction conditions in accordance with JIS L1096 breathability test method (method A), the breathability that entered from the connecting layer of the cross section of the four sides of the three-dimensional knitted fabric and penetrated the surface knitted fabric was measured. The test was carried out three times per sample, and the average was taken.

[0057] (e) Air permeability (cm ３ / (cm ２The air permeability of the three-dimensional knitted fabric, which passes from the back layer knitted fabric to the front layer knitted fabric, was measured in accordance with JIS L1096 Air Permeability Test Method (Method A) using an air permeability tester FX3300 Laboair IV manufactured by Takayama Reed Co., Ltd. The test was performed three times per sample, and the average value was taken.

[0058] (f) Taber Abrasion Resistance (ASTM Method) (Grade) In accordance with ASTM 3884-9 method (rotating platform double-head method), a Taber abrasion tester was used, and the test piece was abraded 1000 times with a CS-10 abrasion wheel at a load of 1000 g and a speed of 72 rpm. After the test, the abrasion state of the surface of the test piece was observed, and a grade was determined in 0.5 grade increments based on the following evaluation criteria in accordance with JASO M403 A method. The test was performed twice per sample (twice with different samples), and the lower grade was adopted. (Evaluation Criteria) Grade 5: No change in surface condition Grade 4: Slight fuzzing Grade 3: Heavy fuzzing Grade 2: Heavy fuzzing and thinning of the thread Grade 1: Thread breakage.

[0059] (g) Compression softness (compression stress evaluation) (gf / cm ２ ) Using a KES compression tester (Kato Tech Co., Ltd. KES-G5), ２ The disk-shaped compression tool was used to compress a 15 cm square, 15 cm thick, T ０ A three-dimensional knitted fabric sample (mm) was cut to 50% of its thickness (1 / 2T) at a speed of 5 mm / sec. ０ The test was carried out three times for each sample (three times with different samples), and the average of the maximum stress values ​​was calculated.

[0060] (h) Amount of lint (fiber waste) during cutting (amount of lint per meter of cut) (mg / m) Using a press machine, a circular die cutter with a diameter of 5 cm was used to cut the three-dimensional knitted fabric into a circle, and the cut surface of the circular sample was blown with air to remove lint, and the weight loss was recorded as the amount of lint. Specifically, using an air blow gun with a diameter of 3 mm, air was blown (for 20 seconds) over the entire cut surface of the circular sample under conditions of an air pressure of 0.2 MPa and an air consumption rate of 200 L / min. The weight loss of the circular sample before and after air blowing was recorded as the amount of lint. This was repeated for 10 samples, and the total weight loss was measured. This was then divided by the cut length of 1 m to record the amount of lint (fiber waste) during cutting (mg / m).

[0061] (i) Seating Comfort A seat frame (without a backrest) was prepared, with a seat portion made of a 520 mm wide, 470 mm deep, and 420 mm high metal pipe material. A 1.5 cm thick zelkova board (air-dry specific gravity: 0.68) was fixed to the seat surface. A knitted fabric measuring 500 mm wide (in the weft direction of the knitting) and 470 mm long (in the warp direction of the knitting) was placed on this seat surface (zelkova board). Five panelists (weighing between 50 and 85 kg) sat on the seat for five minutes with their knees aligned along the length of the knitted fabric, and then left the seat. To evaluate seating comfort, the flexibility and fit of the knitted fabric were evaluated sensorily using the following four-point scale. (Evaluation Criteria) 4 points: The knitted fabric had adequate cushioning, resulting in excellent seating comfort. 3 points: The knitted fabric had a hard cushioning, resulting in slightly poor seating comfort. 2 points: The knitted fabric had a hard cushioning, resulting in poor seating comfort. 1 point: The knit fabric has no cushioning, and the bottom feels like a board, making it uncomfortable to sit on. A total score of 18 to 20 points by the five panelists was given as "◎", 15 to 17 points as "○", 12 to 14 points as "△", and 11 points or less as "×".

[0062] Three-dimensional knit fabrics (Examples 1 to 7) of the present embodiment and Comparative Examples 1 to 3 were produced by the following procedure: [Comparative Example 1] Using a double Russell knitting machine equipped with six reeds and having a 22 gauge and a 6 mm shuttle spacing, two false-twisted yarns of 167 dtex 48 filament polyethylene terephthalate fiber (black spun-dyed yarn) were pulled together and combined and supplied in a 1-in-1-out (L2) and 1-out-1-in (L3) arrangement from the two reeds (L2, L3) forming the knitted fabric of the front layer, a monofilament of 110 dtex polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in a 1-in-1-out (L4) arrangement from the reed (L4) forming the connecting portion, and further, a false-twisted yarn of 110 dtex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in an all-in arrangement from the two reeds (L5, L6) forming the knitted fabric of the back layer. A three-dimensional knitted fabric was knitted using the knitting structure shown below with 35 courses per 2.54 cm on the knitting machine. The resulting knitted fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180°C for 1 minute with an overfeed rate of 0%, to obtain a three-dimensional knitted fabric having the physical properties shown in Table 1 below. (Knit structure) L2: 1011 / 2322 / / (1 in 1 out) L3: 2322 / 1011 / / (1 out 1 in) L4: 3410 / 4367 / / (1 in 1 out) L5: 1110 / 1112 / / (all in) L6: 2223 / 1110 / / (all in)

[0063] Example 1 Using the three-dimensional knit fabric prepared in Comparative Example 1, an ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) was applied as follows. Specifically, Kasesol KH-920 was diluted with water to prepare a 15% by mass solution. The solution was then adjusted to a solution temperature of 20°C and a gravure roll was adjusted so that the solution application amount was 10% by mass. The three-dimensional knit fabric was set and transported so that the surface layer was facing downward, and the gravure roll was applied so that it contacted the surface of the surface layer of the three-dimensional knit fabric from below, without applying the solution to the connecting yarns or back surface of the three-dimensional knit fabric. Next, the three-dimensional knit fabric was dried at 120°C for 3 minutes with the surface facing downward using a pin tenter, and then further heated at 150°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0064] Example 2 A three-dimensional knit fabric was obtained in the same manner as in Comparative Example 1, except that the monofilaments forming the connecting portions were changed from 110 dtex to 56 dtex polyethylene terephthalate fibers (black spun-dyed yarn). An ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) was applied using the fabric as follows: Specifically, Kasesol KH-920 was diluted with water to prepare a 15% by mass solution. The solution was then adjusted to a solution temperature of 20°C and the gravure roll was adjusted so that the solution application amount was 10% by mass. The three-dimensional knit fabric was set and transported with the surface layer facing downward, and the solution was applied so that the gravure roll contacted the surface of the surface layer of the three-dimensional knit fabric from below, without applying it to the connecting yarns or back layer of the three-dimensional knit fabric. Subsequently, the fabric was dried at 120°C for 3 minutes with the surface layer facing downward using a pin tenter, and then further heated at 150°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0065] [Example 3] Using a double Russell knitting machine equipped with six reeds and a 22 gauge and a 6 mm shuttle spacing, two false twisted yarns of 167 dtex 48 filament polyethylene terephthalate fiber (black spun-dyed yarn) were pulled together and combined from the two reeds (L1, L2) that formed the surface knitted fabric, and supplied in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement. Two reeds (L3, L4) that formed the connecting portion supplied monofilaments of 56 dtex polyethylene terephthalate fiber (black spun-dyed yarn) in a 1-in-1-out (L3) and 1-out-1-in (L4) arrangement. Furthermore, two reeds (L5, L6) that formed the back knitted fabric supplied false twisted yarns of 110 dtex 36 filament polyethylene terephthalate fiber (black spun-dyed yarn), both in an all-in arrangement. A three-dimensional knitted fabric was knitted with the knit structure shown below, with 35 courses per 2.54 cm on the machine. An ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) was applied using the fabric as follows: Specifically, Kasesol KH-920 was diluted with water to prepare a 20% by mass solution. The solution was then adjusted to a solution temperature of 20°C and the gravure roll was adjusted so that the solution application amount was 15% by mass. The three-dimensional knitted fabric was set and transported with the surface layer facing downward, and the gravure roll was applied to the surface of the surface layer of the three-dimensional knitted fabric from below, avoiding application to the connecting yarns and backside of the three-dimensional knitted fabric. Subsequently, the fabric was tentered 5% with the surface layer facing downward using a pin tenter, and dried at a temperature of 120°C with an overfeed rate of 0% for 3 minutes, and then further heated at a temperature of 180°C for 1 minute to obtain a three-dimensional knitted fabric with the physical properties shown in Table 1 below. (Knit structure) L1: 1011 / 2322 / / (1 in 1 out) L2: 2322 / 1011 / / (1 out 1 in) L3: 3410 / 4367 / / (1 in 1 out) L4: 4367 / 3410 / / (1 out 1 in) L5: 1110 / 1112 / / (all in) L6: 2223 / 1110 / / (all in)

[0066] Example 4 Using the three-dimensional knit fabric prepared in Comparative Example 1, a press mold (W1: 7 mm, W2: 38 mm) with the design shown in Figure 1 was used to heat press the surface layer side at a press mold temperature of 200°C for 6 seconds, resulting in a three-dimensional knit fabric with a concave deformation portion. This was then used to apply an ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) as follows: Kasesol KH-920 was diluted with water to prepare a 13% by mass solution. The solution was then adjusted to a liquid temperature of 20°C and the gravure roll was adjusted so that the solution application amount was 12% by mass. The three-dimensional knit fabric was set and transported with the surface layer facing downward, and the solution was applied so that the gravure roll contacted the surface of the surface layer of the three-dimensional knit fabric from below, avoiding application to the connecting yarns and back surface of the three-dimensional knit fabric. Subsequently, the three-dimensional knit fabric was dried at 120°C for 3 minutes with the surface layer facing downward using a pin tenter, and then further heated at 150°C for 1 minute to obtain a three-dimensional knit fabric with the physical properties shown in Table 1 below.

[0067] Example 5 A three-dimensional knit fabric was prepared in the same manner as in Comparative Example 1, except that the interval between the kettle assemblies was changed to 3 mm. A urethane-based hard finishing agent (Evafal HA-207, NICCA Chemical Co., Ltd.) was applied to the fabric as follows: Specifically, Evafal HA-207 was diluted with water to prepare a 30% by mass solution. The gravure roll was then adjusted so that the solution was applied in an amount of 25.2% by mass at a liquid temperature of 20°C. The three-dimensional knit fabric was set and transported with the surface layer facing downward, and the solution was applied so that the gravure roll contacted the surface of the surface layer of the three-dimensional knit fabric from below, avoiding application to the connecting yarns and back surface of the three-dimensional knit fabric. Subsequently, the fabric was dried at 120°C for 3 minutes using a pin tenter with the surface layer facing downward, and then further heated at 150°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0068] [Example 6] Using a double Russell knitting machine equipped with six reeds, 18 gauge, and a 10 mm shuttle interval, two false twisted yarns of 334 dtex 96 filament polyethylene terephthalate fiber (black dope-dyed yarn) were pulled together and combined from two reeds (L1, L2), and supplied in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement. Two reeds (L3, L4) that form the connecting portion supplied 200 dtex polyethylene terephthalate fiber (black dope-dyed yarn). The monofilaments were supplied in a 1-in-1-out (L3) and 1-out-1-in (L4) arrangement, and furthermore, false twisted yarn of 334 dtex 96 filament polyethylene terephthalate fiber (black dope-dyed yarn) was supplied in an all-in arrangement from two reeds (L5, L6) forming the back layer knitted fabric, to form a roughly hexagonal mesh knitted fabric, with the relative phase of the front and back knitted fabrics being the same pitch, and a grey machine with 6 on-machine courses per 2.54 cm was obtained.

[0069] Next, an ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) was applied as follows. Specifically, Kasesol KH-920 was diluted with water to prepare a 40% by mass solution. Then, the bar coater was adjusted so that the solution was applied in an amount of 5.5% by mass at a liquid temperature of 20°C. The solution was quickly applied to the surface layer of the three-dimensional knit fabric, while being careful not to apply it to the connecting yarns or back surface of the three-dimensional knit fabric. Next, the fabric was dried at 100°C for 2 minutes with the surface layer facing down using a pin tenter, and then further heated at 180°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0070] [Example 7] Using a double Russell knitting machine equipped with six reeds, 18 gauge, and a 10 mm hook interval, two false twisted yarns of 480 dtex 144 filament polyethylene terephthalate fiber (black dope-dyed yarn) were pulled together and combined from two reeds (L1, L2), and supplied in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement. Two reeds (L3, L4) that form the connecting portion were used to knit two false twisted yarns of 200 dtex polyethylene terephthalate fiber (black dope-dyed yarn). Monofilaments were supplied in a 1-in-1-out (L3) and 1-out-1-in (L4) arrangement, and furthermore, false twisted yarn of 480 dtex 144 filament polyethylene terephthalate fiber (black dope-dyed yarn) was supplied in an all-in arrangement from two reeds (L5, L6) forming the back layer knitted fabric, forming an approximately hexagonal mesh knitted fabric, with the relative phase of the front and back knitted fabrics being the same pitch, and a grey machine with 12 courses / 2.54 cm on the machine was obtained.

[0071] Next, an ester-based hard finishing agent (Kasesol KH-920, Nicca Chemical Co., Ltd.) was applied as follows. Specifically, Kasesol KH-920 was diluted with water to prepare a 35% by mass solution. Then, the roll coater was adjusted so that the solution was applied in an amount of 10% by mass at a liquid temperature of 20°C. The three-dimensional knit fabric was set and transported so that the surface layer was facing downward, and the solution was applied so that the roll coater contacted the surface of the surface layer of the three-dimensional knit fabric from below, without applying the solution to the connecting yarns or back surface of the three-dimensional knit fabric. Subsequently, the three-dimensional knit fabric was dried at 100°C for 2 minutes with the surface layer facing downward using a pin tenter, and then further heated at 180°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0072] Comparative Example 2 An ester-based hard finishing agent (Kasesol KH-920, manufactured by Nicca Chemical Co., Ltd.) was diluted with water to prepare a 15% by mass solution. The solution was placed in a bath at a liquid temperature of 20°C, and the three-dimensional knit fabric produced in Comparative Example 1 was impregnated with the solution. The fabric was then squeezed with a mangle to coat the fabric with a solution amount of 28% by mass. The fabric was then dried at 120°C for 3 minutes using a pin tenter, and then further heated at 180°C for 1 minute to obtain a three-dimensional knit fabric having the physical properties shown in Table 1 below.

[0073] [Comparative Example 3] Using a double Russell knitting machine equipped with six reeds, 18 gauge, and a 4 mm hook interval, two false twisted yarns of 167 dtex 48 filament polyethylene terephthalate fiber (black dope-dyed yarn) were pulled together and combined from two reeds (L1, L2), and supplied in a 1-in-1-out (L1) and 1-out-1-in (L2) arrangement. Two reeds (L3, L4) that form the connecting portion were used to supply two false twisted yarns of 200 dtex polyethylene terephthalate fiber (black dope-dyed yarn). Monofilaments were supplied in a 1-in-1-out (L3) and 1-out-1-in (L4) arrangement, and a false twisted yarn of 167 dtex 48 filament polyethylene terephthalate fiber (black spun-dyed yarn) was supplied in an all-in arrangement from the two reeds (L5, L6) forming the back layer knitted fabric, forming a roughly hexagonal mesh knitted fabric. The relative phase of the front and back knitted fabrics was the same pitch, and the on-machine course was 12 courses / 2.54 cm. The resulting green fabric was removed from the knitting machine, widened by 5% using a pin tenter, and dry-heat set at 180 ° C for 1 minute with an overfeed rate of 0%, to obtain a three-dimensional knitted fabric with the physical properties shown in Table 1 below.

[0074]

[0075] All of the three-dimensional knitted fabrics of this embodiment exhibited excellent comfort and durability. Surprisingly, it was found that the greater the absolute values ​​of the abrasion resistance grade (E1) of the top layer surface and the abrasion resistance grade (E2) of the bottom layer surface, as well as the greater the difference between them (E1 - E2), the greater the cushioning effect of the three-dimensional knitted fabric when sitting.

[0076] The three-dimensional knitted fabric of the present invention has practical breathability and flexibility while also having excellent durability and cushioning properties, and is therefore useful, for example, as interior and covering materials for vehicles (such as automobiles) and furniture, and can also be used in nursing care products, bedding, clothing, household goods, etc.

[0077] W1: Recess width W2: Non-recess width

Claims

1. A three-dimensional knitted fabric comprising a surface knitted fabric, a back knitted fabric, and a connecting yarn connecting the surface knitted fabric and the back knitted fabric, wherein the three-dimensional knitted fabric contains 90% by mass or more of polyester, a hard finishing agent is applied to the surface of the fibers constituting the surface knitted fabric of the three-dimensional knitted fabric, and the maximum stress of the three-dimensional knitted fabric when compressed by 50% is 500 gf / cm ２ A three-dimensional knitted fabric, characterized in that it is below the above-mentioned and satisfies the following formulas (1) to (3): E1 ≥ 3.0 (1) E2 ≥ 1.0 (2) E1 - E2 ≥ 1.0 (3) {wherein E1 is the abrasion resistance grade by Taber abrasion of the front layer surface of the three-dimensional knitted fabric, and E2 is the abrasion resistance grade by Taber abrasion of the back layer surface of the three-dimensional knitted fabric.} 2. The three-dimensional knit fabric according to claim 1, wherein the hard finish is a polyester-based hard finish or a polyurethane-based hard finish.

3. The air permeability from the back knitted fabric to the surface knitted fabric is 50 cm ３ / (cm ２ 3. The three-dimensional knitted fabric according to claim 1 or 2, wherein the knitting time is equal to or more than 1 / 2 sec.

4. A three-dimensional knitted fabric according to claim 1 or 2, wherein the amount of the hard finishing agent applied is 0.5% by mass to 10% by mass relative to 100% by mass of the entire three-dimensional knitted fabric.

5. The three-dimensional knitted fabric according to claim 1 or 2, wherein only the surface knitted fabric has a hard finish.

6. A surface material made of the three-dimensional knitted fabric according to claim 1 or 2.

7. A vehicle in which the skin material according to claim 6 is used as an interior material.

8. A method for using the three-dimensional knitted fabric according to claim 1 or 2 as a skin material, characterized in that the surface knitted fabric of the three-dimensional knitted fabric is used as the outermost surface of the skin material.

9. A method for producing a three-dimensional knitted fabric according to claim 1 or 2, comprising the following step: applying a hard finishing agent solution having a concentration of 5% to 40% by mass to the outer surface of the three-dimensional knitted fabric so that the amount of the solution applied is within the range of 5% to 30% by mass based on the entire three-dimensional knitted fabric.

10. The method for producing a three-dimensional knitted fabric according to claim 9, wherein no hard finishing agent is applied to the knitted fabric of the back layer of the three-dimensional knitted fabric.

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