Synthetic resin skin material

Abstract

To provide a synthetic resin skin material having good moldability at ordinary temperature.SOLUTION: A synthetic resin skin material comprises a skin layer containing a resin, and the skin layer has a 1 kgf constant load elongation rate at 23°C in a width direction measured under a load of 1 kgf in accordance with ASTM D 3107 (2019) of 7% to 100% and a 1 kgf constant load set rate at 23°C in the width direction of 0.5% to 15%.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to synthetic resin skin materials. [Background technology]

[0002] 2. Description of the Related Art Synthetic resin skin materials, which have excellent durability, are often used in place of natural leather, fiber sheets, etc. for automobile interior parts such as instrument panels, door trims, seats, and ceilings, railway car and aircraft interior parts such as trims, seats, and ceilings, furniture, shoes, footwear, bags, interior and exterior components for building decoration, clothing coverings and linings, wall coverings, etc.

[0003] For example, when a synthetic resin skin material is used instead of natural leather, the outermost surface of the synthetic resin skin material is formed with an unevenness similar to that of natural leather, i.e., a grain pattern. In addition, the synthetic resin skin material may be required to have a deeper unevenness pattern in order to further enhance the design.

[0004] Conventionally, when forming a concave-convex pattern on a skin material such as synthetic leather, it is necessary to carry out molding processing at room temperature, such as compression molding, stamping molding using a pair of dies, etc. Furthermore, when a synthetic resin skin material is used for the interior of an automobile, for example, since parts such as an automobile door have three-dimensional shapes in both the up-down and left-right directions, it is preferable that the synthetic resin skin material used for the door has a certain degree of stretchability in both the up-down and left-right directions.

[0005] When providing a synthetic resin skin with irregularities, when fixing the synthetic resin skin to a substrate having a three-dimensional shape for interior use, etc., hot molding can impart thermal extensibility to the synthetic resin skin. However, with hot molding, there are concerns that the appearance and texture of the resin used in the synthetic resin skin may be affected by heat, and that the substrate having a three-dimensional shape may be affected by heat, so the moldability of the synthetic resin skin at room temperature is important.

[0006] However, known synthetic resin skin materials do not have sufficient elasticity, and therefore there is concern that wrinkles, sagging, etc. may occur during molding when compression molding, stamping molding, etc. are performed at room temperature.

[0007] A wet-process synthetic leather has been proposed as a synthetic leather with good appearance, texture, breathability, and mechanical properties. In this synthetic leather, a surface layer is formed on a pretreated substrate using a wet process, the substrate is peeled off from the surface layer, and a base fabric is bonded to the peeled surface with an adhesive (see Patent Document 1).

[0008] The wet-laid synthetic leather described in Patent Document 1 is described as being able to be distributed as a laminate prior to attachment to a base fabric by pretreating the substrate, and also as having good adhesion to the base fabric after attachment to the base fabric.

[0009] A thermoplastic polymerizable composition has been proposed for obtaining a skin material that has good shape conformability and flexibility at room temperature and is less likely to wrinkle when applied to a substrate (see Patent Document 2). The thermoplastic polymerizable composition described in Patent Document 2 contains a 4-methyl-1-pentene / α-olefin copolymer and a propylene-based resin having specific physical properties, and is described as being suitable for use as a skin layer in a skin material. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 09-031859 [Patent Document 2] JP 2014-214227 A Summary of the Invention [Problem to be solved by the invention]

[0011] However, the synthetic resin skin material described in Patent Document 1 uses a wet method and requires special processing equipment, which is not preferable from the viewpoint of productivity. Furthermore, according to the inventor's investigation, the synthetic leathers described in Patent Documents 1 and 2 have good flexibility. However, they are still insufficient in terms of moldability at room temperature and the effect of suppressing wrinkles when subjected to stamping molding at room temperature.

[0012] An object of one embodiment of the present invention is to provide a synthetic resin skin material that has good moldability at room temperature. [Means for solving the problem]

[0013] The means for solving the problems include the following aspects. <1> A synthetic resin skin material having a skin layer containing resin, and a constant load elongation rate of 1 kgf (9.8 N) in the width direction at 23°C, measured at a load of 1 kgf (9.8 N) in accordance with ASTM D 3107 (2019), of 7% to 100%, and a constant load set rate of 1 kgf (9.8 N) in the width direction at 23°C of 0.5% to 15%. <2> The synthetic resin skin material has a 1 kgf constant load elongation rate in the length direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the length direction at 23°C of 0.5% to 15%. <1> 2. The synthetic resin skin material according to claim 1 . <3> The resin includes at least one selected from the group consisting of a urethane resin and a polyvinyl chloride resin. <1> or <2> 2. The synthetic resin skin material according to claim 1 . <4> Further, the base fabric <1> ~ <3> 10. The synthetic resin skin material according to claim 9, <5> The base fabric is a knitted fabric. <4> 2. The synthetic resin skin material according to claim 1 . <6> The base fabric is a knitted fabric having a 10 kgf (98 N) constant load elongation rate in the width direction at 23°C, measured at a load of 10 kgf (98 N) in accordance with ASTM D 3107 (2019), of 40% to 150%, and a 10 kgf (98 N) constant load set rate in the width direction at 23°C of 0.5% to 15%. <4> or <5> 2. The synthetic resin skin material according to claim 1 . Effect of the Invention

[0014] According to one embodiment of the present invention, a synthetic resin skin material having good moldability at room temperature can be provided. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a synthetic resin skin material according to the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing another embodiment of the synthetic resin skin material of the present disclosure. [Diagram 3] FIG. 1 is a perspective view of a molding die A, which is one embodiment of a die used when molding a synthetic resin skin material in an embodiment of the present disclosure. [Figure 4] FIG. 2 is a perspective view of a molding die B, which is another embodiment of a die used when molding a synthetic resin skin material in an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The synthetic resin skin material of the present disclosure will be described in detail below. The following description of the configuration elements may be based on representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.

[0017] In the present disclosure, the use of "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower limit and upper limit. In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.

[0018] In the present disclosure, combinations of two or more preferred embodiments are more preferred embodiments. In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0019] In the present disclosure, the term "step" refers not only to an independent step, but also to a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved. In this disclosure, the length direction of a synthetic resin skin material refers to the direction parallel to the conveying direction of a manufacturing device that manufactures a long synthetic resin skin material, and the width direction refers to the direction perpendicular to the length direction on the surface of the synthetic resin skin material.

[0020] The length and width directions of the synthetic resin skin material can be confirmed by observing the orientation of the resin under a transmission electron microscope in the case of a single-layer or multi-layer skin material containing resin, and when the synthetic resin skin material has a base fabric, the length and width directions can be confirmed by observing the structure of the base fabric.

[0021] In this disclosure, 1 kgf is equal to 9.8 N. In this disclosure, "room temperature" refers to 23°C unless otherwise specified. In the present disclosure, the moldability at room temperature (room temperature processability) refers to the moldability when the temperature of the synthetic resin skin material to be processed is room temperature.

[0022] In the present disclosure, the term "layer containing a resin" refers to a "layer formed containing a resin that is the main component of the layer." In other words, the term "layer containing a resin" in the present disclosure is used to include both a resin layer containing only a resin, and a layer formed of a resin composition that further contains optional components such as a plasticizer, a colorant, and an ultraviolet absorber in addition to the resin that is the main component.

[0023] Here, the term "resin as a main component" in the present disclosure refers to a resin that is contained in an amount of 60 mass% or more based on the total amount of the resin composition containing the component. In the present disclosure, the resin as a main component constituting the layer is also referred to as a "base resin".

[0024] In the present disclosure, the term "molded article" refers to a molded article (a base of a molded article) before decoration. Hereinafter, in this disclosure, the synthetic resin skin material may be simply referred to as the "skin material." [Synthetic resin skin material] The synthetic resin skin material of the present disclosure (hereinafter sometimes simply referred to as "the skin material of the present disclosure") has a skin layer containing a resin, and has a 1 kgf (9.8 N) constant load elongation in the width direction at 23°C measured at a load of 1 kgf in accordance with ASTM D 3107 (2019) of 7% to 100%, and a 1 kgf (9.8 N) constant load set rate in the width direction at 23°C of 0.5% to 15%.

[0025] Synthetic resin skin materials are often used for molded articles having a three-dimensional shape in both the vertical and horizontal directions, such as vehicle doors. In this case, it is preferable for the skin material to have a certain degree of stretchability in both the vertical and horizontal directions. According to the inventor's research, it has been found that by having a certain degree of stretchability in the vertical direction of the molded article, i.e., in the width direction of the skin material, as described below in detail, the molding processability at room temperature when used for the molded article is good.

[0026] The skin material of the present disclosure has at least a skin layer containing a resin. As described in detail below, the skin material of the present disclosure may have a single-layer structure consisting of only the skin layer, or may have a multi-layer structure including the skin layer and any other layers.

[0027] In both the single-layer structure and the multi-layer structure, the skin material of the present disclosure has a 1 kgf constant load elongation in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

[0028] Since the elongation rate at 1 kgf constant load at 23° C. in the width direction of the skin material and the set rate at 1 kgf constant load at 23° C. in the width direction are both within the above-mentioned ranges, the stretchability properties in the width direction of the skin material of the present disclosure are adjusted to a suitable range, and the molding processability at room temperature is good. (1kgf constant load elongation rate) The 1 kgf constant load elongation of the skin material of the present disclosure is measured in accordance with ASTM D 3107 (2019).

[0029] The 1 kgf constant load elongation rate can be measured using a constant load elongation tester. In the present disclosure, the values ​​measured using a constant load elongation tester (FLM-6M (product name), manufactured by Daiei Scientific Instruments Manufacturing Co., Ltd.) are used.

[0030] The measurement sample is a test piece cut from the skin material to a width of 80 mm and a length of 200 mm. The test piece is fixed to the constant load elongation tester and measured at a load of 1 kgf (9.8 N) in accordance with ASTM D 3107 (2019). The measurement conditions are as follows.

[0031] Gauge line spacing 100mm Grip distance 150mm Load 1kgf(9.8N) Time Loading 10 minutes Weight removal 10 minutes Ambient temperature: 23℃±2℃ The 1 kgf constant load elongation is calculated using the following formula.

[0032] Constant load elongation rate (%) = {(L1-L0) / L0} x 100 In the above formula, L0 represents the gauge length (mm) before the test, and L1 represents the gauge length (mm) 10 minutes after the load is applied.

[0033] The elongation percentage at a constant load of 1 kgf at 23° C. in the width direction calculated by the above formula is from 7% to 100%, and preferably from 15% to 60%. (1kgf constant load set rate) The 1 kgf constant load set rate of the skin material of the present disclosure is measured at a load of 1 kgf in accordance with ASTM D 3107 (2019).

[0034] The 1 kgf constant load set rate can also be measured using a constant load elongation tester. In the present disclosure, the 1 kgf constant load set rate is measured using the same testing machine as that used to measure the 1 kgf constant load elongation rate.

[0035] The measurement samples and measurement conditions are also the same. The 1kgf constant load set rate is calculated using the following formula. Constant load set rate (%) = {(L2-L0) / L0} x 100 In the above formula, L0 represents the gauge length (mm) before the test, and L2 represents the gauge length (mm) 10 minutes after the weight was removed.

[0036] The set rate in the width direction under a constant load of 1 kgf at 23° C. calculated by the above formula is 0.5% to 15%, and preferably 0.5% to 10%. The skin material of the present disclosure preferably has a 1 kgf constant load elongation in the longitudinal direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the longitudinal direction at 23°C of 0.5% to 15%.

[0037] The elongation rate at 1 kgf constant load and the set rate at 1 kgf constant load at 23° C. in the longitudinal direction can be measured in the same manner as in the transverse direction, by changing the width direction of the test piece to the longitudinal direction.

[0038] The measured elongation rate under a constant load of 1 kgf at 23° C. in the length direction is preferably 7% to 100%, and more preferably 15% to 60%. The set rate measured in the length direction under a constant load of 1 kgf at 23° C. is preferably 0.5% to 15%, and more preferably 0.5% to 10%.

[0039] Since the elongation rate at 1 kgf constant load at 23° C. in the lengthwise direction as well as the widthwise direction of the skin material and the set rate at 1 kgf constant load at 23° C. in the lengthwise direction are all within the above-mentioned ranges, the stretch properties in the lengthwise and widthwise directions of the skin material of the present disclosure are adjusted to fall within suitable ranges, resulting in better moldability at room temperature. [Layer structure of skin material] Next, the layer structure of the skin material will be described.

[0040] As described above, the skin material of the present disclosure may be a single-layer structure consisting of only a skin layer containing a resin, or may be a multi-layer structure including any other layer in addition to the skin layer. Fig. 1 is a schematic cross-sectional view showing one embodiment of a skin material of the present disclosure. The skin material 10 shown in Fig. 1 has a skin layer 12 and a surface treatment layer 14 provided on one side of the skin layer 12. The surface treatment layer 14 in Fig. 1 is an optional layer provided to adjust at least one of the appearance and the feel of the skin material 10.

[0041] In addition, in each drawing of this disclosure, components indicated by the same reference numerals are meant to be the same components. Fig. 2 is a schematic cross-sectional view showing another embodiment of the skin material of the present disclosure. The skin material 20 shown in Fig. 2 has a layer structure in which, in a laminate of the skin layer 12 and the surface treatment layer 14 as shown in Fig. 1, the skin layer 12 has an adhesive layer 16 on the surface opposite to the surface treatment layer 14, and the skin layer and the base fabric 18 are bonded via the adhesive layer 16. The skin material 20 shown in Fig. 2 has, on the base fabric 18, the adhesive layer 16, the skin layer 12, and the surface treatment layer 14 in this order from the base fabric 18 side. The surface treatment layer 14, the adhesive layer 16, and the base fabric 18 shown in Fig. 2 are optional layers that are provided as desired. [Epidermal layer] The skin layer is a required layer of the skin of the present disclosure.

[0042] The skin layer is a layer containing a resin. -resin- There is no particular limitation on the resin contained in the surface layer, and any resin that can be molded into a sheet can be used. Examples of the resin include urethane resin, polyvinyl chloride resin (hereinafter sometimes abbreviated as PVC), acrylic resin, polyester resin, silicone resin, polyolefin resin, polystyrene elastomer resin, etc.

[0043] Among these, it is preferable to use at least one resin selected from the group consisting of urethane resins and polyvinyl chloride resins, from the viewpoints that the 1 kgf constant load elongation percentage and 1 kgf constant load set percentage under 23° C. conditions can be easily adjusted to fall within preferred ranges, and various performance properties required of a skin material can be easily obtained.

[0044] Examples of the urethane resin contained in the surface layer include polycarbonate-based polyurethane, polyether-based polyurethane, polyester-based polyurethane, and modified products thereof. Among these, polycarbonate-based polyurethane is more preferable from the viewpoint of easily achieving various performances required for the surface material.

[0045] When the surface layer contains urethane resin, the urethane resin should have a hardness of 4 MPa (4 × 10) at 100% modulus measured at 20°C in accordance with JIS K 6251 (1993). 6N / m 2 It is preferable that the pressure is in the range of 100 to 40 MPa.

[0046] When the hardness of the resin measured at 20° C. is within the above range, the skin material obtained using the resin can be easily controlled to have preferable stretch properties, that is, the constant load elongation rate and constant load set rate, within preferable ranges.

[0047] Methods for adjusting the hardness (100% modulus) of the urethane resin include, for example, increasing the ratio of the polyol component that becomes the soft segment or increasing the molecular weight of the polyol to make it softer, and increasing the number of urethane bonds or urea bonds that become the hard segments to make it harder, and adding a crosslinking agent such as hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI) to impart energy and form a crosslinked structure.

[0048] Examples of PVC contained in the skin layer include vinyl chloride homopolymers having an average degree of polymerization of 650 to 1800, ethylene / vinyl chloride copolymers, and the like. -Other additives- In addition to the above resin, known additives may be added to the surface layer, if necessary, so long as the effect is not impaired.

[0049] Examples of additives that the skin layer may contain include colorants, crosslinking agents, crosslinking accelerators, film-forming assistants, flame retardants, and foaming agents. -Coloring agent- The surface layer may contain a colorant. By containing a colorant, a desired hue can be imparted to the surface layer, and design properties can be improved.

[0050] There are no particular limitations on the colorant, and it can be appropriately selected from pigments, dyes, etc. depending on the purpose. Examples of colorants include inorganic pigments such as titanium white (titanium dioxide), zinc white, ultramarine, cobalt blue, red iron oxide, vermilion, yellow lead, titanium yellow, and carbon black, organic pigments or dyes such as quinacridone, permanent red 4R, isoindolinone, Hansa Yellow A, phthalocyanine blue, indanthrene blue RS, and aniline black, metal pigments selected from the group consisting of foil powder of metals such as aluminum and brass, and pearlescent (pearl) pigments selected from the group consisting of foil powder of titanium dioxide-coated mica and basic lead carbonate, etc. Among these, pigments are preferred as colorants from the viewpoint of better durability and light resistance.

[0051] When the surface layer contains a pigment as the colorant, a pigment dispersant such as a surfactant or a polymer dispersant may be used in combination. When the skin layer contains a colorant, the content of the colorant can be, for example, in the range of 0.5% by mass to 50% by mass, and preferably in the range of 5% by mass to 25% by mass, relative to the total mass of the skin layer. -Additives other than colorants- The skin layer may further include additives other than colorants.

[0052] For example, the surface layer may contain a known flame retardant such as a phosphorus-based, halogen-based, or inorganic metal-based flame retardant, thereby improving the flame retardancy of the surface material. [Formation of epidermal layer] The skin layer can be formed by a known method.

[0053] The surface layer can be formed by preparing a composition for forming a surface layer containing a resin and, if desired, additives such as a colorant and a solvent, and molding the resulting composition for forming a surface layer.

[0054] The composition for forming the surface layer can be prepared by dissolving the resin in a solvent. Examples of the solvent that can be used to prepare the composition for forming the surface layer include dimethylformamide (DMF), methyl ethyl ketone (MEK), isopropyl alcohol (IPA), toluene, and the like, and a mixed solvent of two or more of these.

[0055] Hereinafter, the solvents may be referred to by the above-mentioned abbreviations. The surface layer can be formed by forming a film from a composition for forming a surface layer by a known film forming method such as a calendar method, a paste processing method, or a melt extrusion method.

[0056] Alternatively, the skin layer can be formed by applying the composition for forming the skin layer onto a release paper. As the release paper, either a release paper for transferring a grain pattern or a smooth release paper can be used. By using a release paper for transferring a grain pattern, a concave-convex pattern called a grain pattern can be formed on the surface of the skin layer.

[0057] The thickness of the skin layer is appropriately selected depending on the intended use of the skin material. From the viewpoint of improving the moldability and texture of the skin material, the thickness of the skin layer after drying is preferably 10 μm to 500 μm, and more preferably 20 μm to 150 μm.

[0058] When there are two or more skin layers, the thickness of the skin layer refers to the total thickness of the multiple skin layers. The thickness of the substrate layer and the thickness of each layer of the skin material described below can be measured by observing a cut surface of the skin material cut perpendicular to the surface direction. In the present disclosure, the thickness of the skin layer is measured at five randomly selected points on the cut surface, and the arithmetic average value is defined as the thickness of the skin layer. The thicknesses of the other layers can be measured in the same manner.

[0059] Therefore, in this disclosure, the thickness of each layer in the skin material refers to the thickness of each layer after it has been dried. As described above, the skin material of the present disclosure may have a single-layer structure consisting of a skin layer containing a resin. In the case of a single-layer skin material, the physical properties of the skin layer itself are preferably such that the elongation rate at 1 kgf constant load in the width direction at 23°C is 7% to 100%, and the set rate at 1 kgf constant load in the width direction at 23°C is 0.5% to 15%.

[0060] In the case of a single-layer skin material, the above physical properties can be achieved by controlling the type, molecular weight, and content of the resin contained in the skin layer, as well as the formulation and thickness of the composition for forming the skin layer, including additives that are optionally contained. The thickness of the skin layer is appropriately adjusted within the above range. [Other layers] The skin material of the present disclosure may further include layers other than the skin layer (hereinafter, sometimes referred to as "other layers").

[0061] Examples of the other layers include a base fabric that serves as the substrate for the skin material, an adhesive layer, a surface treatment layer, a primer layer, an intermediate layer, and the like. (base fabric) The covering material of the present disclosure may have a base fabric.

[0062] There are no particular limitations on the base fabric, so long as it has the necessary strength and flexibility, and the resulting skin material has the desired stretchability. Examples of fibers used for the base fabric include synthetic fibers such as polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol, and natural fibers such as cotton and hemp, and may be selected according to the purpose.

[0063] In addition, when the skin material has a base fabric, the elasticity of the skin material may be affected by the elasticity of the base fabric, so it is preferable to select the base fabric taking into consideration not only its strength and flexibility, but also the elasticity of the base fabric alone.

[0064] The base fabric may be any of woven fabric, knitted fabric, and nonwoven fabric. Among them, knitted fabric is preferred from the viewpoint of easily imparting a certain degree of stretchability in the width direction of the skin material. Examples of knitted fabrics include warp knitted tricot knitted fabrics, double raschel knitted fabrics, circular knitted pique knitted fabrics, interlock knitted fabrics, mocrody knitted fabrics, and weft knitted fabrics, with interlock knitted fabrics, which are a type of double-sided knitting, being more preferred.

[0065] The basis weight of the base fabric used for the skin material is set to 30 g / m from the viewpoints of better moldability, appearance after molding, and texture.2 ~400g / m 2 is preferred, and 30 g / m 2 ~300g / m 2 is more preferred.

[0066] The basis weight of the base fabric, for example, in the case of a knitted fabric, can be adjusted by the structure of the knitted fabric, the thickness of the fibers used in knitting, the structure, the density of the fibers, and the like. The thickness of the base fabric used for the skin material is preferably 0.2 mm to 1.4 mm, and more preferably 0.2 mm to 1.0 mm, from the viewpoints of better molding processability, and better appearance and feel after molding.

[0067] From the viewpoint of the stretchability of the base fabric, the 10 kgf constant load elongation at 23°C measured at a load of 10 kgf (98 N) in accordance with ASTM D 3107 (2019) of the base fabric alone is preferably 40% to 150% in the width direction, more preferably 40% to 130%. In addition, the constant load set rate at 23°C measured at a load of 10 kgf (98 N) in accordance with ASTM D 3107 (2019) of the base fabric alone is preferably 0.5% to 15% in the width direction, more preferably 3% to 10%.

[0068] Furthermore, the constant load elongation at 23°C measured on the base fabric alone in the same manner as above is preferably 40% to 150%, more preferably 40% to 130%, in the length direction, and the constant load set rate at 23°C is preferably 0.5% to 15%, more preferably 3% to 10%, in the length direction.

[0069] When the constant-load elongation rate and constant-load set rate of the base fabric alone, measured by the above-mentioned method, are within the above-mentioned ranges, it tends to be easier to adjust the constant-load elongation rate and constant-load set rate of the skin material having the base fabric to the above-mentioned physical properties.

[0070] The constant load elongation rate and constant load set rate of the base fabric alone can be measured in accordance with ASTM D 3107 (2019) using a constant load elongation tester, for example, FLM-6M (product name) manufactured by Daiei Scientific Instruments Co., Ltd. For the measurement, a test piece cut from the base fabric to a width of 80 mm and a length of 200 mm is used.

[0071] The constant load elongation rate and constant load set rate of the base fabric are calculated using the following formulas. Constant load elongation rate (%) = {(L1-L0) / L0} x 100 Constant load set rate (%) = {(L2-L0) / L0} x 100 In the above formula, L0 represents the gauge length (mm) before the test, L1 represents the gauge length (mm) 10 minutes after the load was applied, and L2 represents the gauge length (mm) 10 minutes after the load was removed.

[0072] The measurement conditions when the base fabric is measured alone are as follows. Gauge line spacing 100mm Grip distance 150mm Load 10kgf(98N) Time Loading 10 minutes Weight removal 10 minutes Ambient temperature: 23℃±2℃ That is, the constant load elongation rate and constant load set rate measured on the base fabric alone are values ​​measured under load conditions different from those in the measurements on the skin material. (Adhesive layer) The skin material of the present disclosure may have an adhesive layer. For example, when the skin material has a base fabric, the adhesive layer may be provided between the skin layer and the base fabric to improve the adhesion between the base fabric and the skin layer. Also, when an optional layer is provided between the skin layer and the base fabric, the adhesiveness between the optional layer formed adjacent to the base fabric and the base fabric can be improved.

[0073] The adhesive constituting the adhesive layer is not particularly limited, and examples thereof include adhesives containing resins such as urethane resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, and acrylic resins.

[0074] Examples of the urethane resin contained in the adhesive include resins selected from polycarbonate-based polyurethanes, polyether-based polyurethanes, polyester-based polyurethanes, and modified versions of these.

[0075] Among these, from the viewpoint of improving the various performances required of the skin material, adhesives containing urethane resin or polyvinyl chloride resin are preferred, and adhesives containing polycarbonate-based polyurethane are more preferred.

[0076] From the viewpoint of improving adhesion between the base fabric and the adjacent layer and improving moldability, the resin contained in the adhesive preferably has a 100% modulus at 20°C of 1.0 MPa to 6.0 MPa, and more preferably 1 MPa to 3 MPa.

[0077] The thickness of the adhesive is preferably from 2.0 μm to 80.0 μm, and more preferably from 25.0 μm to 60.0 μm, from the viewpoints of further improving the adhesion between adjacent layers and improving the texture.

[0078] The thickness of the adhesive layer can be controlled by the amount of adhesive applied. (Surface treatment layer) The skin material of the present disclosure may have a surface treatment layer. For example, when the skin material of the present disclosure has a base fabric, the surface treatment layer may be provided on the surface of the skin layer opposite to the surface on the base fabric side. The surface treatment layer is generally provided on the outermost surface of the skin material for the purpose of improving at least one of the appearance, texture (feel), and abrasion resistance of the skin material.

[0079] Examples of the resin contained in the surface treatment layer include polyurethane, acrylic resin, fluororesin, polyvinyl chloride resin, etc., and from the viewpoint of further improving abrasion resistance and texture, it is preferable to contain polyurethane as the main component.

[0080] The polyurethane may be a polycarbonate-based polyurethane, a polyether-based polyurethane, a polyester-based polyurethane, or a modified product thereof. From the viewpoint of various performances required of the skin material, it is preferable that the surface treatment layer contains a polycarbonate-based polyurethane.

[0081] The method for producing the surface treatment layer is not particularly limited, and the surface treatment layer is formed by applying a composition for forming the surface treatment layer obtained by dissolving the above-mentioned resin in an appropriate solvent, or a surface treatment agent composition containing the above-mentioned resin in the form of an aqueous emulsion or dispersion, to the surface of the epidermis layer.

[0082] When preparing the composition for forming the surface treatment layer, examples of non-aqueous organic solvents that can be used to dissolve the resin include dimethylformamide (DMF), methyl ethyl ketone (MEK), isopropyl alcohol (IPA), toluene, etc., and mixed solvents of two or more of these.

[0083] The aqueous emulsion resin or dispersion resin is a resin dispersion in which the resin is contained in a uniform emulsion state in an aqueous medium or a non-aqueous organic solvent (or dispersion medium). Examples of the aqueous medium used in the resin dispersion include water, alcohol, and a mixed medium of two or more of these. The non-aqueous solvent used in the resin dispersion can be the same as the above-mentioned solvents.

[0084] The surface treatment layer may contain other components in addition to the above-mentioned resin and solvent (dispersion medium). Examples of other components include a crosslinking agent, an organic filler, a lubricant, a flame retardant, etc. For example, when the surface treatment layer contains an organic filler, a lubricant, etc., the surface material is given a smooth feel and the abrasion resistance is further improved.

[0085] From the viewpoint of obtaining a sufficient effect of improving the abrasion resistance and texture of the skin material, the thickness of the surface treatment layer is preferably in the range of 1.0 μm to 10.0 μm, and more preferably in the range of 1.0 μm to 7.5 μm. (Method of manufacturing skin material) The method for producing the skin material of the present disclosure is not particularly limited, and the skin material can be produced by any known method.

[0086] When the skin material of the present disclosure has a single-layer structure, a layer preferably containing a urethane resin may be formed by the above-mentioned known method such as extrusion or coating in accordance with the method for forming the skin layer.

[0087] When the skin material of the present disclosure has a multi-layer structure, for example, a method can be used in which a skin layer is first formed on the surface of a release paper, and then any desired layers are sequentially formed. When the multi-layered skin material has a base fabric, the skin material can be obtained by contacting the adhesive layer side of a laminate of a skin layer formed on the surface of a release paper and an adhesive layer formed as required with the prepared base fabric and pressing the laminate together to adhere the adhesive layer to the base fabric.

[0088] The skin layer may or may not be formed using a release paper. The release paper may be selected from known release papers according to the purpose. The release paper may be a release paper for transferring a grain pattern or a smooth release paper.

[0089] The method of forming the skin layer on the surface of the release paper can be a known method. In general, the method of forming the skin layer includes a method of applying the composition for forming the skin material described above to the surface of the release paper and drying it to form the skin layer. In addition, if there is no problem with the transfer of the grain pattern, the skin layer may be provided on the surface of the release paper by a transfer method.

[0090] The adhesive layer, which is an optional layer, can be formed by applying the above-mentioned adhesive layer-forming composition to the surface of the skin layer. The method for applying the adhesive layer-forming composition to the surface of the skin layer may be a coating method or a transfer method.

[0091] A heat treatment may be carried out when the laminate and the base fabric are pressed and bonded together, or after the press and bond. The laminate including the base fabric, the adhesive layer, and the surface layer can be heated by a known method. There are no particular limitations on the heating means, and any known heating means such as heating using a heated roll, heating with hot air, or heating in a heating and drying oven may be used.

[0092] Here, it can be said that one of the preferred embodiments is to bond the adhesive layer to the base fabric and perform the heat treatment while the adhesive layer is still uncured. By contacting the adhesive layer formed on the surface of the skin layer with the base fabric and applying pressure to bond the adhesive layer, some of the fibers contained in the base fabric can easily penetrate into the adhesive layer, and the adhesive layer and the base fabric can be more firmly attached. Furthermore, the adhesive layer is hardened by the subsequent heat treatment, which improves the adhesiveness with the base fabric and improves the peel strength between the base fabric and the skin layer in the obtained skin material.

[0093] After the adhesive layer and the skin layer are cured by the heat treatment, the release paper is peeled off from the surface of the skin layer to obtain the skin material. The above-mentioned method for manufacturing the skin material is merely an example, and other known methods for manufacturing skin materials may be used.

[0094] The skin material of the present disclosure has favorable elastic properties, and therefore has good processability at room temperature. It can be applied to the surfaces of various three-dimensional molded articles to give them a good appearance, and has a wide range of applications. Examples of three-dimensional molded articles to which the skin material of the present disclosure can be applied include vehicle interior materials for automobiles, trains, etc., furniture, aircraft, ships, building decorations, wall decorations, etc., and the skin material of the present disclosure can be suitably used for decorating various molded articles. EXAMPLES

[0095] The skin material of the present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the following specific examples. In the following examples, the percentages indicating the concentrations and contents of each component are by mass unless otherwise specified. Example 1 (Step I: Formation of epidermal layer) The components were thoroughly mixed according to the following recipe to obtain a surface layer forming composition 1 with a solid content of about 13%. The following "(1) one-component resin, polycarbonate-based polyurethane resin with a solid content of 20%" is the main resin in the surface layer. (Epidermal layer forming composition 1 formulation) (1) One-component resin: Polycarbonate-based polyurethane resin with 20% solids (100% modulus at 20°C: 5MPa) 100 parts by mass (2) Solvent (DMF) 20 parts by weight (3) Solvent (PGM) 15 parts by weight (4) Solvent (IPA) 5 parts by weight (5) Colorant (black pigment: carbon black) 15 parts by mass The skin layer forming composition 1 was applied to a release paper using a knife coater in a wet coating amount of 150 g / m 2 The coating was applied so that the result was as follows.

[0096] The formed coating layer of the composition 1 for forming a surface layer was dried at 100° C. for 2 minutes using a hot air dryer to form a surface layer on the release paper. The thickness of the surface layer after drying was about 20 μm. (Step II: Maturation of the surface layer and removal of the release paper) The surface layer formed in step I was aged at 50° C. for 48 hours, and then the release paper was peeled off. (Step III: Formation of surface treatment layer) The components were thoroughly mixed according to the following recipe to obtain a composition 1 for forming a surface treatment layer having a solid content of about 14%. (Surface treatment layer forming composition 1 formulation) (1) One-component resin: Polycarbonate-based polyurethane resin with 15% solids 100 parts by mass (2) Solvent (MEK) 5 parts by weight After peeling off the release paper obtained in step II, the composition for forming the surface treatment layer obtained above was applied in a wet amount of 10 g / m to one side of the surface layer. 2 The coating was applied so that the result was as follows.

[0097] The coating was heated at 90° C. for 1 minute using a hot air dryer to form a surface treatment layer having a thickness of 1.4 μm on the surface layer. In this manner, a skin material of Example 1 having the skin layer and the surface treatment layer and having the layer structure shown in FIG. 1 was obtained. Example 2 The (1) polyurethane resin (main resin) in the composition 1 for forming a skin layer used in the formation of the skin layer in step I of Example 1 was changed to (1-2) a one-component polycarbonate-based polyurethane resin having a solid content of 30% (100% modulus at 20°C: 10 MPa), to obtain a composition 2 for forming a skin layer having a solid content of approximately 16%.

[0098] A skin material of Example 2 having a skin layer and a surface treatment layer was obtained in the same manner as in Example 1, except that composition 2 for forming a skin layer was used instead of composition 1 for forming a skin layer. Example 3 The (1) polyurethane resin (main resin) in the composition 1 for forming a skin layer used in the formation of the skin layer in step I of Example 1 was changed to (1-3) a one-component polyester polyurethane resin having a solid content of 20% (100% modulus at 20°C: 35 MPa), to obtain a composition 3 for forming a skin layer having a solid content of approximately 13%.

[0099] A skin material of Example 3 having a skin layer and a surface treatment layer was obtained in the same manner as in Example 1, except that composition 1 for forming a skin layer was changed to composition 3 for forming a skin layer. Example 4 After step I and before step II of Example 1, the following steps IV and V were carried out in this order. (Step IV: Formation of adhesive layer) The components were thoroughly mixed according to the following recipe to obtain a composition 1 for forming an adhesive layer having a solid content of about 45%. (Adhesive layer forming composition 1 formulation) (1) Two-component resin: Polycarbonate-based polyurethane resin with 70% solids (100% modulus at 20°C: 2.5MPa) 100 parts by mass (2) Solvent (DMF) 50 parts by weight (3) Isocyanate-based crosslinking agent: 6 parts by mass The adhesive layer-forming composition 1 was applied in a wet amount of 100 g / m to the surface of the skin layer formed on the release paper obtained in the step I. 2 The coating was performed so as to form a coating layer.

[0100] The coating layer was heated at 120° C. for 2 minutes using a hot air dryer to form an adhesive layer having a thickness of 45 μm on the surface of the skin layer. (Process V: Laminating the base fabric) As the base fabric, interlock knit fabric (weight: 110g / m 2 A 0.7 mm thick plate was prepared.

[0101] The adhesive layer formed in step IV was laminated to the above-mentioned base fabric prepared in step IV. The heating temperature during lamination was 130°C. (Stretchability of base fabric) For the interlock knit fabric used in Example 4, the base fabric alone was measured for the 10 kgf constant load elongation rate in the width direction and length direction at 23 ° C. and the 10 kgf constant load set rate in the width direction and length direction at 23 ° C. in accordance with ASTM D 3107 (2019). The results are shown in Table 1 below.

[0102] Thereafter, in the same manner as in step III of Example 1, a surface treatment layer was formed on the surface of the skin layer opposite the adhesive layer, to obtain the skin material of Example 4 having the layer structure shown in FIG. 2 , which has the adhesive layer, the skin layer, and the surface treatment layer in this order on the base fabric. Example 5 Instead of the interlock knit fabric used in Example 4, a mocrody knit fabric (weight: 390 g / m 2 A skin material of Example 5 having an adhesive layer, a skin layer and a surface treatment layer in this order on a base fabric was obtained in the same manner as in Example 4, except that a 1.2 mm thick polyester fiber sheet (thickness: 1.2 mm) was used.

[0103] The stretch properties of the mocrody knit fabric used in Example 5 were measured in the same manner as in Example 4. The results are shown in Table 1 below. Example 6 Instead of the interlock knit fabric used in Example 4, a tricot knit fabric (weight: 280 g / m 2A skin material of Example 6 having an adhesive layer, a skin layer and a surface treatment layer in this order on a base fabric was obtained in the same manner as in Example 4, except that a 100 mm thick polyester fiber sheet (thickness: 0.9 mm) was used.

[0104] The stretch properties of the tricot knit fabric used in Example 6 were measured in the same manner as in Example 4. The results are shown in Table 2 below. Example 7 (Step I: Formation of epidermal layer) The components were thoroughly mixed according to the following recipe to obtain a skin layer-forming composition 4 having a solid content of about 100%. The following “(1) polyvinyl chloride resin (average polymerization degree 1300)” is the main resin in the skin layer-forming composition 4. (Epidermal layer forming composition 4 formulation) (1) Polyvinyl chloride resin (average degree of polymerization: 1300) (100% modulus at 20℃: 7MPa) 100 parts by mass (2) Plasticizer (dialkyl phthalate) 75 parts by mass (3) Stabilizer (Ba-Zn-based composite stabilizer) 2 parts by mass (4) Filler (calcium bicarbonate) 10 parts by weight (5) Colorant (black pigment: carbon black) 5 parts by mass The composition 4 for forming the surface skin layer was applied to the release paper using a knife coater in a wet coating amount of 150 g / m 2 The coating was applied so that the result was as follows.

[0105] The formed coating layer of the composition 4 for forming a surface skin layer was dried at 100° C. for 2 minutes using a hot air dryer to form a surface skin layer on the release paper. The thickness of the surface skin layer after drying was about 150 μm.

[0106] A skin material of Example 7 having a skin layer and a surface treatment layer was obtained in the same manner as in Example 1, except that the obtained skin layer was used. Comparative Example 1 The (1) polyurethane resin in the composition 1 for forming a skin layer used in the formation of the skin layer in step I of Example 1 was changed to (1-C1) a one-component polyester polyurethane resin having a solid content of 20% (100% modulus at 20°C: 2 MPa), to obtain a composition C1 for forming a skin layer having a solid content of approximately 13%.

[0107] A skin material of Comparative Example 1 having a skin layer and a surface treatment layer was obtained in the same manner as in Example 1, except that the skin layer-forming composition 1 was changed to the skin layer-forming composition C1. Comparative Example 2 The (1) polyurethane resin in the composition 1 for forming a skin layer used in the formation of the skin layer in step I of Example 1 was changed to (1-C2) a one-component polyester polyurethane resin having a solid content of 20% (100% modulus at 20°C: 50 MPa), to obtain a composition C2 for forming a skin layer having a solid content of approximately 13%.

[0108] A skin material of Comparative Example 2 having a skin layer and a surface treatment layer was obtained in the same manner as in Example 1, except that the skin layer-forming composition 1 was changed to the skin layer-forming composition C2. Comparative Example 3 Instead of the interlock knitted fabric used in Example 4, a woven fabric (weight: 365 g / m 2 A skin material of Comparative Example 3 having an adhesive layer, a skin layer and a surface treatment layer in this order on a base fabric was obtained in the same manner as in Example 4, except that a 100 mm thick polyester fiber sheet (thickness: 0.95 mm) was used.

[0109] The stretch properties of the woven fabric used as the base fabric in Comparative Example 3 were measured in the same manner as in Example 4. The results are shown in Table 2 below. [Evaluation of skin material] The following items were evaluated for the skin materials of Examples 1 to 7 and Comparative Examples 1 to 3. The results are shown in Tables 1 and 2. (1. Measurement of elongation rate and set rate at 1kgf constant load in the width and length directions at 23℃) Using the method described above, the 1 kgf constant load elongation rate and 1 kgf constant load set rate of the skin material were measured in the width direction and length direction at 23°C under a load of 1 kgf in accordance with ASTM D 3107 (2019). (2. Evaluation of light resistance) A light resistance test was carried out under the following conditions in accordance with JIS D 0205 (1987), and the covering material was visually observed before and after the test and evaluated according to the following criteria.

[0110] Testing machine: Light fastness testing machine (U48AUH (product name) manufactured by Suga Testing Machine Co., Ltd.) (Test conditions) Black panel temperature 83℃ Time 400 hours Irradiance 500W / m 2 (300nm~700nm) (Evaluation Criteria) A: No visible discoloration of the skin B: Slight discoloration is confirmed visually on the surface material. C: The surface material is clearly discolored. In the above evaluation criteria, levels A and B are practically acceptable, with level A being preferred. (3. Evaluation of humidity and heat resistance) The moist heat resistance test was conducted in accordance with JIS C 60068-3-4 (2004).

[0111] Testing machine: Constant temperature and humidity testing machine (PL-3J (product name) manufactured by Espec Corporation) (Test conditions) Temperature / humidity 70℃×95%RH Time 840 hours (Evaluation method) A tensile test was carried out on the skin material before and after the moist heat resistance test, and the strength retention rate (%) after the test relative to the strength before the test was calculated.

[0112] The tensile tests were carried out in accordance with JIS K 7139 (2009). Testing machine: Tensile testing machine (Shimadzu Corporation, Autograph AGS-100NX (product name)) (Measurement conditions) Test piece: Width 30mm, length 150mm Grip interval: 100mm Grip width 50mm Tensile speed: 100mm / min (Evaluation Criteria) A: Strength retention is 80% or more B: Strength retention rate is 50% or more but less than 80% C: Strength retention is less than 50% In the above evaluation criteria, levels A and B are practically acceptable, with level A being preferred. (4. Molding processability) Compression molding was carried out under the following conditions using a compression molding machine (HC300-05 (product name) manufactured by AS ONE Corporation).

[0113] The surface temperature of the skin material was adjusted to 23°C. The molds used were mold A shown in a perspective view in Fig. 3 and mold B shown in a perspective view in Fig. 4. The symbols M and C written next to each mold indicate the length direction and width direction of the skin material, respectively.

[0114] Mold A has convex portions parallel to the length direction and with smooth tops, while mold B has convex portions formed of densely packed quadrangular pyramids in the length direction and width direction, and mold B has a more complex shape in the left-right direction (width direction) compared to mold A.

[0115] The base of the molded body is made of ABS (acrylonitrile / butadiene / styrene copolymer) resin, and a chloroprene adhesive is applied to the surface of the base at a rate of 150 g / m. 2 After coating, a dry substrate was applied.

[0116] The skin material was set so that its width direction was set as the C direction of the mold. The mold temperature was 40° C. (surface measurement temperature), the molding pressure was 0.25t, and the pressing time was 60 seconds.

[0117] Under the above conditions, the molded body before decoration (base of the molded body) was placed in a mold, the obtained skin material was laminated on the adhesive-coated surface of the molded body, and the compression molding machine was used to simultaneously form an uneven shape on the molded body using the mold and to compress the skin material onto the molded body, thereby obtaining a molded product with an uneven shape on its surface decorated with the skin material.

[0118] The appearance of the obtained molded article was visually evaluated according to the following criteria. (Evaluation Criteria) A: No visible wrinkles or sagging B: Slight wrinkles or sagging was observed by visual inspection. C: Wrinkles and sagging were evident, and the appearance was questionable. In the above evaluation criteria, levels A and B are practically acceptable, with level A being preferred.

[0119] [Table 1]

[0120] [Table 2]

[0121] From the results in Tables 1 and 2, it can be seen that the skin materials of Examples 1 to 7 all had good light resistance, moist heat resistance, and moldability at room temperature, and were at a level that presented no practical problems. In contrast, Comparative Example 1, in which the constant load elongation rate was too high, and Comparative Example 2, in which the constant load elongation rate was too low, both had poor molding processability. In addition, Comparative Example 3, which used a base fabric with poor elasticity properties even though the skin layer was good, did not satisfy the constant load elongation rate specified in the present disclosure, and therefore had good light resistance and moist heat resistance but poor molding processability.

[0122] From the above results, the skin materials of the Examples have good moldability when molded without any special heating, and are also excellent in light resistance and moist heat resistance, and are therefore expected to be suitable as skin materials for molded bodies.

[0123] The technical concept is described below. (1) having a surface layer containing a resin, A synthetic resin skin material having a 1 kgf constant load elongation rate in the width direction at 23°C of 7% to 100%, as measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

[0124] (2) The synthetic resin skin material according to technical idea (1), wherein the synthetic resin skin material has a 1 kgf constant load elongation in the length direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the length direction at 23°C of 0.5% to 15%.

[0125] (3) The synthetic resin skin material according to the technical concept (1) or (2), wherein the resin comprises at least one selected from the group consisting of urethane resin and polyvinyl chloride resin. (4) The synthetic resin skin material according to any one of the technical concepts (1) to (3) further comprises a base fabric.

[0126] (5) The synthetic resin skin material according to the technical idea (4), wherein the base fabric is a knitted fabric. (6) The synthetic resin skin material according to technical idea (4) or (5), wherein the base fabric is a knitted fabric having a 10 kgf constant load elongation in the width direction at 23°C of 40% to 150% when measured at a load of 10 kgf in accordance with ASTM D 3107 (2019) and a 10 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%. [Explanation of symbols]

[0127] 10, 20 Synthetic resin skin material (skin material) 12 Epidermal layer 14 Surface treatment layer 16 Adhesive layer 18 Base fabric

Claims

1. A surface layer containing a resin, A synthetic resin skin material having a 1 kgf constant load elongation rate in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

2. A surface layer containing a resin, The resin includes a polycarbonate-based polyurethane or a polyester-based polyurethane, and the hardness of the polycarbonate-based polyurethane or the polyester-based polyurethane, measured at 20°C in accordance with JIS K 6251 (1993), is in the range of 4 MPa to 40 MPa at 100% modulus; A synthetic resin skin material having a 1 kgf constant load elongation rate in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

3. A synthetic resin skin material having a skin layer containing a resin, a base fabric, and an adhesive layer provided between the skin layer and the base fabric, the surface layer comprises a polycarbonate-based polyurethane or a polyester-based polyurethane, the polycarbonate-based polyurethane or the polyester-based polyurethane having a hardness of 4 MPa to 40 MPa at 100% modulus measured at 20°C in accordance with JIS K 6251 (1993); The basis weight of the base fabric is 30 g / m ２ Up to 400 g / m ２ The thickness of the base fabric is 0.2 mm to 1.4 mm; The synthetic resin skin material has a 1 kgf constant load elongation rate in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

4. A surface layer containing a resin, The resin comprises polyvinyl chloride, A synthetic resin skin material having a 1 kgf constant load elongation rate in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

5. A synthetic resin skin material having a skin layer containing a resin, a base fabric, and an adhesive layer provided between the skin layer and the base fabric, the skin layer comprises polyvinyl chloride; The basis weight of the base fabric is 30 g / m ２ Up to 400 g / m ２ The thickness of the base fabric is 0.2 mm to 1.4 mm; The synthetic resin skin material has a 1 kgf constant load elongation rate in the width direction at 23°C, measured at a load of 1 kgf in accordance with ASTM D 3107 (2019), of 7% to 100%, and a 1 kgf constant load set rate in the width direction at 23°C of 0.5% to 15%.

6. The synthetic resin skin material according to any one of claims 1 to 5, wherein the synthetic resin skin material has a 1 kgf constant load elongation rate in the length direction at 23°C measured at a load of 1 kgf in accordance with ASTM D 3107 (2019) of 7% to 100%, and a 1 kgf constant load set rate in the length direction at 23°C of 0.5% to 15%.

7. 2. The synthetic resin skin material according to claim 1, further comprising a base fabric.

8. 8. The synthetic resin skin material according to claim 3, claim 5 or claim 7, wherein the base fabric is a knitted fabric.

9. The base fabric has a 10 kgf constant load elongation rate in the width direction at 23 ° C., measured at a load of 10 kgf in accordance with ASTM D 3107 (2019), of 40% to 150%, and a 10 kgf constant load set rate in the width direction at 23 ° C. of 0.5% to 15%. The synthetic resin skin material according to claim 7 or 8.

10. 6. The synthetic resin skin material according to claim 3, wherein the adhesive layer contains an adhesive containing a urethane resin or a polyvinyl chloride resin, and has a thickness of 2.0 μm to 80.0 μm.

11. Further, the surface treatment layer is provided. The synthetic resin skin material according to any one of claims 1 to 10, wherein the surface treatment layer is a layer containing a polycarbonate-based polyurethane and having a thickness of 1.0 µm to 10.0 µm.

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