Synthetic resin skin material and method for producing same

Abstract

To provide a synthetic resin skin material which has excellent dirt-wiping property and can demonstrate designability through an appearance different from those of the conventional skin materials and its manufacturing method.SOLUTION: An uneven pattern is formed on a surface of a synthetic resin skin material including a skin layer, and an uneven shape of the surface in a cross section including a point with the largest thickness of unevenness of the surface and a point with the smallest thickness of it satisfies the following conditions (1) to (3). The uneven surface pattern that satisfies the conditions (1) to (3) is formed by embossing a resin sheet. (1) A convex part has a top and an inclined part sloping from the top to a bottom of an adjacent concave part, and of two angles formed by an intersection of a horizontal line touching the top and a line along the inclined part, an angle on a side containing the convex part is 160° to 178°. (2) Horizontal opening length of the concave part is 2 mm to 13 mm. (3) Depth of the concave part is 0.1 mm to 0.4 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a synthetic resin skin material and a method for manufacturing a synthetic resin skin material. [Background technology]

[0002] Synthetic resin skin materials (which may be simply referred to as "skin materials" in this disclosure) that are highly durable are often used in place of natural leather or fiber sheets for automobile interior parts such as instrument panels, door trim, seats, and ceilings, railway car and aircraft interior parts such as trim, seats, and ceilings, furniture, shoes, footwear, bags, interior and exterior components for building decoration, clothing covering materials and linings, wall covering materials, and the like. As an example of a synthetic resin skin material, Patent Document 1 discloses a synthetic leather in which a substrate is pretreated to have a peel strength of 10 g / cm to 300 g / cm, a wet silver layer is formed on the upper surface of the substrate by a normal method, and after post-processing, the substrate is peeled off to produce a wet silver layer product. The surface of the wet silver layer product from which the substrate has been peeled off is then coated with an adhesive or a base fabric is coated with an adhesive, and the base fabric is bonded to the surface, thereby producing a synthetic leather. Such synthetic leather (synthetic resin skin material) generally has an uneven surface, i.e., a grain pattern, similar to that of natural leather, on the outermost surface, and this grain pattern is a major defining feature of the appearance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-031859 Summary of the Invention [Problem to be solved by the invention]

[0004] When dirt adheres to the surface of a synthetic resin skin material, it can be difficult to completely wipe off the dirt depending on the uneven shape of the surface. Furthermore, today's society has become more diverse in its values, and there is a demand for the development of skin materials with new appearances that are different from conventional ones.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a synthetic resin skin material that is excellent in dirt wiping removability and can exhibit designability with an appearance different from that of conventional skin materials, and a manufacturing method thereof. [Means for solving the problem]

[0006] The means for solving the problem include the following embodiments. <1> A synthetic resin skin material including a skin layer containing a synthetic resin, the synthetic resin skin material having a concave-convex pattern formed on the surface thereof, the concave-convex shape of the surface in a cross section including a point where the thickness of the concave-convex on the surface is greatest and a point where the thickness is smallest, satisfies all of the following conditions (1) to (3): (1) The convex portion has an apex and an inclined portion inclined from the apex toward the bottom of the adjacent concave portion, and is in contact with the apex. Of the two angles formed by the intersection of a line perpendicular to the thickness direction of the skin material and a line along the inclined portion, the angle on the side including the convex portion is 160° to 178°. (2) The opening length of the recess in the direction perpendicular to the thickness direction of the skin is 2 mm to 13 mm. (3) The depth of the recess is 0.1 mm to 0.4 mm. <2> The projections and recesses are arranged repeatedly in a constant pattern in at least one of the length direction and the width direction of the synthetic resin skin material. <1> 2. The synthetic resin skin material according to claim 1 . <3> The projections and recesses are repeatedly arranged in a constant pattern in both the length direction and width direction of the synthetic resin skin material. <2> 2. The synthetic resin skin material according to claim 1 . <4> The projections and recesses are arranged over the entire surface of the synthetic resin skin material so as to present a geometric pattern. <1> ~ <3> 10. The synthetic resin skin material according to claim 9, <5> The three-dimensional surface roughness of the surface having the irregularities of the synthetic resin skin material is 1.637 μm or less. <1> ~ <4> 10. The synthetic resin skin material according to claim 9, <6> <1> ~ <5> 2. A method for producing the synthetic resin skin material according to claim 1, comprising the steps of: preparing a synthetic resin sheet including a synthetic resin layer for forming the skin layer; a step of embossing the synthetic resin layer using an embossing roll or an embossing plate to form a concave-convex pattern that satisfies all of the above conditions (1) to (3) on the surface of the synthetic resin sheet; A method for producing a synthetic resin skin material, comprising: Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a synthetic resin skin material that is excellent in ease of wiping off dirt and that exhibits design potential with an appearance that is different from that of conventional skin materials, and a method for manufacturing the same. [Brief description of the drawings]

[0008] [Figure 1] For one example (Example 1) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged by 10 times are shown. [Diagram 2] FIG. 1 shows, for an example (Example 3) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Diagram 3] FIG. 1 shows, for an example (Example 5) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Figure 4] FIG. 1 shows, for an example (Example 7) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Diagram 5]FIG. 13 is a diagram showing, for an example (Example 9) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Figure 6] FIG. 11 is a diagram showing (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged tenfold for an example (Example 11) of a synthetic resin skin material according to the present disclosure. [Figure 7] FIG. 13 is a diagram showing, for an example (Example 13) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Figure 8] FIG. 15 is a diagram showing (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged tenfold for one example (Example 15) of a synthetic resin skin material according to the present disclosure. [Figure 9] FIG. 17 is a diagram showing (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged tenfold for one example (Example 17) of a synthetic resin skin material according to the present disclosure. [Figure 10] FIG. 14 shows, for an example (Example 19) of a synthetic resin skin material according to the present disclosure, (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Figure 11] FIG. 1 shows, for an example of a conventional synthetic resin skin material (Comparative Example 1), (A) a surface on which irregularities are formed, (B) a cross-sectional shape at a measurement position, and (C) a cross-sectional shape in which the depth (thickness) of the cross-sectional shape is enlarged ten-fold. [Figure 12] 1 shows an example of the uneven shape of the surface in a cross section where the unevenness difference is maximum for a synthetic resin skin material according to the present disclosure. [Figure 13] 1 shows an example of the uneven shape in a cross section where the unevenness difference is maximum in a synthetic resin skin material according to the present disclosure. [Figure 14]1 shows an example of a convex shape in a cross section where the difference in unevenness between convex and concave portions is maximum in a synthetic resin skin material according to the present disclosure. [Figure 15] 1 shows an example of a convex shape in a cross section where the difference in unevenness between convex and concave portions is maximum in a synthetic resin skin material according to the present disclosure. [Figure 16] 1 shows an example of a convex shape in a cross section where the difference in unevenness between convex and concave portions is maximum in a synthetic resin skin material according to the present disclosure. [Figure 17] 1 shows an example of the uneven shape in a cross section where the unevenness difference is maximum in a synthetic resin skin material according to the present disclosure. [Figure 18] 1 shows an example of the uneven shape in a cross section where the unevenness difference is maximum in a synthetic resin skin material according to the present disclosure. [Figure 19] 1 shows an example of a layer structure of a synthetic resin skin material according to the present disclosure. [Figure 20] 1 shows an example of a layer structure of a synthetic resin skin material according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The synthetic resin skin material and the method for producing the same according to the present disclosure will be described in detail below. The description of the components described below may be based on representative embodiments of the present disclosure, but the present disclosure is not limited to the following embodiments. 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 present disclosure, in which numerical ranges are described in stages, an upper limit value described in one numerical range may be replaced by an upper limit value of another numerical range described in stages, or a lower limit value described in one numerical range may be replaced by a 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 of the numerical ranges may be replaced with values ​​shown in the examples. In this disclosure, combinations of preferred aspects are more preferred aspects. 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, polyvinyl chloride resin may be referred to as PVC.

[0010] The inventors of the present disclosure have found that when unevenness is formed on the surface of a skin material to form a pattern by the unevenness, it is possible to present an appearance different from that of conventional skin materials, while when dirt adhering to the surface is wiped off with a cloth, the uneven shape may make the dirt difficult to remove or easy to remove. Thus, after carefully examining the shape of the convex parts, the size of the concave parts, the uneven pattern, etc., it has been found that the inclination angle of the convex parts, the opening length of the concave parts, and the depth of the concave parts in a cross section including the points where the thickness of the surface unevenness is greatest and the points where it is smallest have a large effect on the ease of removing dirt, and that when the uneven shape satisfies certain conditions, dirt adhering to the surface can be easily removed by wiping, and the material presents an appearance different from that of conventional skin materials and exhibits design properties.

[0011] <Synthetic resin skin material> The synthetic resin skin material according to the present disclosure includes a skin layer containing a synthetic resin, and has an uneven pattern formed on the surface of the skin material. The uneven shape of the surface in a cross section including the maximum and minimum thicknesses of the unevenness on the surface on which the uneven pattern is formed (sometimes referred to as the "cross section with the maximum unevenness difference" in the present disclosure) satisfies all of the following conditions (1) to (3): (1) The convex portion has an apex and an inclined portion inclined from the apex toward the bottom of the adjacent concave portion, and is in contact with the apex. Of the two angles formed by the intersection of a line perpendicular to the thickness direction of the skin material and a line along the inclined portion, the angle on the side including the convex portion (sometimes referred to in this disclosure as the "inclination angle of the convex portion") is 160° to 178°. (2) The opening length of the recess in a direction perpendicular to the thickness direction of the skin material (sometimes referred to as the "opening length of the recess" in the present disclosure) is 2 mm to 13 mm. (3) The depth of the recess is 0.1 mm to 0.4 mm. When the irregularities formed on the surface of the skin material satisfy all of the above conditions (1) to (3), the material has excellent wipe-off properties and exhibits a design that provides an appearance different from that of conventional skin materials. The skin material according to the present disclosure will be specifically described below with reference to the attached drawings. For the sake of convenience, the shapes, dimensions, angles, and the like in the drawings are exaggerated as appropriate. The direction perpendicular to the thickness direction of the skin material may be referred to as the "horizontal direction."

[0012] Fig. 12 shows an example of the uneven shape of the surface in a cross section where the unevenness difference of the synthetic resin skin material according to the present disclosure is maximum. As shown in Fig. 12, mountain-shaped protrusions 12 are formed at regular intervals along the horizontal direction (direction D) on the surface of the skin material 10. Each protrusion 12 has a shape that is symmetrical with respect to a straight line P in the thickness direction (direction perpendicular to direction D) that passes through the apex, and the uneven shape satisfies the following conditions (1) to (3).

[0013] (1) Of the two angles α and β formed by the intersection of a horizontal line H that contacts the top of the protrusion 12 and a line L that follows the inclined portion of the protrusion 12, the angle α on the side that includes the protrusion 12 is in the range of 160° to 178°. When the angle α is 160° or more, the angle of the inclined portion of the protrusion 12 is gentle, and even if dirt gets into the recess 14, it is easy to remove. On the other hand, when the angle α is 178° or less, the design of the uneven pattern can be exhibited when the surface of the covering material 10 is viewed in plan. From this viewpoint, the angle α is preferably 165° to 175°.

[0014] (2) The opening length X of the recess 14 is in the range of 2 mm to 13 mm. In the present disclosure, the opening length X of the recess 14 means the horizontal distance between the tops of the two protrusions 12 adjacent to the recess 14. In FIG. 12, the height (thickness) of the tops of the two protrusions 12 adjacent to the recess 14 is the same, but even if the heights of the tops of the protrusions on both sides of the recess are different, the horizontal distance between the tops is the opening length X of the recess. When the opening length X of the recess 14 is 2 mm or more, even if dirt gets into the recess 14, it is difficult to cause clogging and is easy to remove. On the other hand, when the opening length X of the recess 14 is 13 mm or less, it is possible to exhibit the design by the uneven pattern when the surface of the skin material 10 is viewed in a plane. From this viewpoint, the opening length X of the recess 14 is preferably 3 mm to 10 mm.

[0015] (3) The depth Y of the recess 14 is in the range of 0.1 mm to 0.4 mm. The depth Y of the recess 14 means the distance in the thickness direction from the tops of the two protrusions 12 adjacent to the recess 14 to the bottom of the recess 14. In FIG. 12, the height (thickness) of the tops of the two protrusions 12 adjacent to the recess 14 is the same, but when the heights of the tops of the protrusions on both sides of the recess are different, the depth Y of the recess is the distance in the thickness direction from the top of the higher (thicker) to the bottom of the recess. When the depth Y of the recess 14 is 0.1 mm or more, the design of the uneven pattern can be exhibited when the surface of the skin material 10 is viewed in a plane. On the other hand, when the depth Y of the recess 14 is 0.4 mm or less, even if dirt enters the recess 14, it is difficult to cause clogging and is easily removed. From this viewpoint, the depth Y of the recess 14 is preferably 0.2 mm to 0.3 mm.

[0016] The measurement points for the unevenness of the surface of the skin material 10 are determined by drawing a straight line connecting the two points with the largest unevenness difference (the point with the largest thickness of the unevenness on the surface and the point with the smallest thickness) in a plan view, and measuring the two points on a cross section along the line. In other words, the unevenness between the two points with the largest unevenness difference is measured. Specifically, the measurement can be performed using a 3D scanner.

[0017] The uneven pattern on the surface of the skin material according to the present disclosure is not particularly limited, but it is preferable that the unevenness is repeatedly arranged in a certain pattern in at least one of the length direction and width direction of the skin material, and the unevenness may be repeatedly arranged in a certain pattern in both the length direction and width direction. By arranging the unevenness pattern in one or both of the length direction and width direction of the skin material, a regular design can be presented by the unevenness pattern, and the design can be improved. Note that the "uneven pattern" in the present disclosure is not limited to the case where unevenness is regularly formed in one or both of the length direction and width direction of the skin material, but means an arrangement of unevenness that presents a design pattern by the unevenness.

[0018] Furthermore, the surface unevenness of the skin material according to the present disclosure may satisfy the above-mentioned conditions (1) to (3) not only in the cross section where the unevenness difference is maximum, but also in cross sections in other directions within the plane. By forming an uneven pattern in which the unevenness in the cross section satisfies conditions (1) to (3) over the entire surface of the synthetic resin skin material, the ease of wiping off dirt can be further improved.

[0019] The unevenness on the surface of the skin material is preferably arranged so as to present a geometric pattern over the entire surface in a plan view. The geometric pattern formed by the unevenness on the surface of the skin material may be a pattern created by continuously developing a combination arrangement of components such as polygons (e.g., triangles, quadrangles, hexagons) and simple figures (e.g., circles, ellipses, and straight lines) while performing operations such as translation, inversion, rotation, enlargement, reduction, and division, or a pattern generated by a geometric curve that can be expressed by a periodic function.

[0020] Examples of patterns based on the concave-convex pattern on the surface of the skin material according to the present disclosure include, but are not limited to, the patterns shown in Figs. 1 to 10 described below as examples.

[0021] From the viewpoint of the ease of wiping off dirt, the uneven surface of the skin material according to the present disclosure preferably has a three-dimensional surface roughness of 1.637 μm or less, and more preferably 1.500 μm or less. The three-dimensional surface roughness (Sa) was determined by measuring the two-dimensional roughness in at least four directions on the surface side of the skin material at a measurement pitch of 20 μm intervals using a skin material 10 mm long and 10 mm wide, and calculating the arithmetic mean roughness according to the following formula (1).

[0022]

number

[0023] In the above formula (1), Z(x, y) represents the surface shape curve Z measured with the average plane as the XY plane and the vertical direction (thickness direction) as the Z axis, dx and dy represent the measured length in the x direction and the measured length in the y direction, respectively, and A represents the measured area.

[0024] Specifically, the three-dimensional surface roughness (Sa) is measured using a contact-type three-dimensional surface roughness meter ("Surfcorder SE-30K" manufactured by Kosaka Laboratory Co., Ltd.), analyzed using three-dimensional surface shape analysis software ("Surf Top Eye" manufactured by Mitani Shoji Co., Ltd.), and calculated using the above formula (1).

[0025] Next, other examples of the uneven shape of the synthetic resin skin material according to the present disclosure will be described. Figs. 13 to 18 each show an example of the uneven shape in a cross section where the unevenness difference is maximum in the synthetic resin skin material according to the present disclosure. In each example, the uneven shape satisfies all of conditions (1) to (3), and the preferred range of each condition is the same as the preferred range described above for the skin material 10 shown in Fig. 12. In addition, the arrangement in the length direction and width direction of the skin material, the geometric pattern formed by the unevenness pattern, and the three-dimensional surface roughness of the surface are also the same as those of the skin material shown in Fig. 12.

[0026] 13, the tops of the protrusions 22 are flat, and the bottoms of the recesses 24 are also flat. In the skin 20 shown in FIG 13, the distance between the tops of adjacent protrusions 22 in the horizontal direction is the opening length X of the recess 14.

[0027] 14 shows a protrusion 32 having a shape in which the angle of the inclined portion changes stepwise. In the protrusion 32 having such a shape, the angle α is defined as a straight line L along the inclined portion of the protrusion 32, which is an extension of the line segment that is closest to the apex among the multiple line segments that constitute the inclined portion of the protrusion 32.

[0028] 15 shows a protrusion 42 having a curved inclined portion. In the protrusion 42 having such a shape, the angle α is defined as a straight line L along the inclined portion that is parallel to a straight line passing through both ends of the inclined portion and is tangent to the inclined portion of the protrusion 42. In addition, when the shape of the convex portion is curved only near the apex, as shown in an exaggerated manner in Figure 2 (C) and Figure 10 (C) in the examples described later, the angle α is defined as a straight line L along the inclined portion, which is an extension of the straight line portion excluding the vicinity of the apex.

[0029] 16 shows an uneven shape in which the convex portions 52 are asymmetric. Each convex portion 52 has two apexes P1 and P2 of different heights, and the inclination angle α of the convex portion 52 is set so that the higher (thicker) apex P1 satisfies condition (1). That is, the angle between the horizontal line H that contacts the apex P1 of the convex portion 52 and the line L1 along the inclined portion on the right side of the paper is α1, and the angle between the line H and the line L2 along the inclined portion on the left side of the paper is α2. Both of these angles α1 and α2 are in the range of 160° to 178°. On the other hand, the opening length X of the recess 54 is the horizontal distance between the tops P1 and P2 of the adjacent protrusions 52. In this disclosure, the "top" of a convexity is a portion that contributes to forming the intended pattern by the concave-convex pattern, and for example, as shown in Figure 6 described below, the portion where the slope is gentle from the convexity to the concave may be considered as part of the slope rather than as the top.

[0030] 17, the convex portions 62 have an asymmetric shape, and the bottom depths of the concave portions 64 vary horizontally. In the case of a skin material 60 having convex portions 62 of this shape, the angle α1 between a horizontal line H that contacts the tops of the convex portions 62 and a line L1 along the inclined portion on the right side of the paper, and the angle α2 between the line H and a line L2 along the inclined portion on the left side of the paper, are both in the range of 160° to 178°. The distance in the thickness direction (vertical direction) from the top of the protrusion 62 to the deepest position of the recess 64 is defined as the depth Y1, Y2 of the recess 64, and both Y1 and Y2 are in the range of 0.1 mm to 0.4 mm. Also, the opening lengths X1, X2 of each recess 64 are both 2 mm to 13 mm.

[0031] 18 shows an example of a concave-convex pattern in which two types of convex portions 72A and 72B with different cross-sectional shapes are alternately formed in the horizontal direction. To the right of the convex portion 72B on the right side of the paper, a convex portion (not shown) similar to the convex portion 72A on the left side is formed. In the case of such a concave-convex shape, all of the following conditions are satisfied.

[0032] (Convex portion 72A and concave portion 74A) Convex portion 72A on the left side when facing the paper surface has an angle α1 between a horizontal line H1 (direction D) contacting the top and a line L1 along the right-side inclined portion in the range of 160° to 178°. Moreover, the opening length X1 of the recess 74A is in the range of 2 mm to 13 mm. Furthermore, the depth Y1 of the recess 74A is in the range of 0.1 mm to 0.4 mm.

[0033] (Convex portion 72B and concave portion 74B) Convex portion 72B on the right side of the drawing forms an angle α2 between a horizontal line H2 (direction D) that contacts the top and a line L2 along the left inclined portion of convex portion 72B, and forms an angle α3 between line H2 and a line L3 along the right inclined portion of convex portion 72B. Both α2 and α3 are in the range of 160° to 178°. Moreover, the opening length X2 of the recess 74B is in the range of 2 mm to 13 mm. Furthermore, the depth Y2 of the recess 74B is in the range of 0.1 mm to 0.4 mm.

[0034] Next, the layer structure and constituent materials of the skin material according to the present disclosure will be described. The skin material according to the present disclosure includes artificial leather, synthetic leather, PVC leather, and the like. The skin material according to the present disclosure includes a skin layer containing a synthetic resin, and the uneven pattern formed on the surface of the skin material only needs to satisfy all of the above-mentioned conditions (1) to (3), and the layer structure is not particularly limited. The skin material according to the present disclosure may be a single-layer product consisting of only a skin layer, or a multi-layer product in which a skin layer is laminated with one or more other layers. In the case of a multi-layer product, it has a layer structure including, for example, a base fabric and a skin layer.

[0035] The skin material according to the present disclosure may be made of the same material as known skin materials. For example, the skin layer is made of synthetic resin such as polyurethane, polyvinyl chloride, etc. The resin constituting the skin material can be selected depending on the application of the skin material, and may contain a plasticizer, a stabilizer, a filler, a colorant, etc. The base fabric may be made of knitted fabric, woven fabric, nonwoven fabric, or the like.

[0036] When the skin material according to the present disclosure has a multi-layer structure, it may include layers other than the skin layer and the base fabric. Fig. 19 shows an example of the layer structure of a skin material according to the present disclosure. The skin material 100 is formed by laminating a base fabric 130 and a skin layer 110 via an adhesive layer 120. The surface of the skin layer 110 is formed with irregularities 114, 112 that satisfy all of the above-mentioned conditions (1) to (3).

[0037] Fig. 20 shows another example of the layer structure of the skin material according to the present disclosure. The skin material 200 further includes a foam layer 140 disposed between the skin layer 110 and the adhesive layer 120 of the skin material 100 shown in Fig. 19. The foam layer 140 can be formed into a layer having a porous structure by foaming a synthetic resin such as PVC with a foaming agent. The inclusion of the foam layer 140 can result in the skin material 200 having high elasticity.

[0038] The skin material according to the present disclosure may have another layer on the surface of the skin layer 110 on which the irregularities are formed. For example, a surface treatment layer for the purpose of imparting a good feel can be included. Even when another layer is formed on the surface of the skin layer 110, the irregularity pattern on the surface of the skin material should satisfy all of the above-mentioned conditions (1) to (3).

[0039] The thickness of the skin material according to the present disclosure is not particularly limited, but from the viewpoints of the strength, handling properties, etc. of the skin material, it is preferably 0.45 mm to 1.8 mm, and more preferably 0.9 mm to 1.2 mm.

[0040] (Method of manufacturing skin material) Although there are no particular limitations on the method for producing a synthetic resin skin material according to the present disclosure, it is preferable to form the irregularities that satisfy conditions (1) to (3) by embossing the surface of the skin material before the irregular pattern is formed using an embossing roll or embossing plate. That is, the method for producing a skin material according to the present disclosure includes the steps of preparing a synthetic resin sheet including a synthetic resin layer for forming the skin layer according to the present disclosure, and embossing the synthetic resin layer using an embossing roll or embossing plate to form an irregularity pattern that satisfies all of conditions (1) to (3) on the surface of the synthetic resin sheet.

[0041] Examples of synthetic resin sheets including a synthetic resin layer for forming a surface layer include a single-layer sheet including only a synthetic resin layer, and a laminated sheet including a synthetic resin layer and a base fabric, etc. The synthetic resin layer may contain, in addition to the synthetic resin, a plasticizer, a stabilizer, a filler, a colorant, an ultraviolet absorbing agent, etc. Next, the synthetic resin layer of the prepared synthetic resin sheet is embossed using an embossing roll or an embossing plate to form a concave-convex pattern on the surface of the synthetic resin sheet.

[0042] For example, when producing a skin material 100 having the layer structure shown in FIG. 19, a skin layer-forming composition containing a synthetic resin or the like is applied to the surface of a release paper using a knife coater to form a skin layer-forming composition layer on the surface of the release paper. A base fabric is attached to the skin layer-forming composition layer via an adhesive to produce a laminate of the base fabric, adhesive layer, and skin layer. The release paper is peeled off from the laminate, and the skin layer is embossed using an embossing roll or embossing plate having a predetermined concave-convex pattern. This makes it possible to produce a skin material 100 having a concave-convex pattern that satisfies conditions (1) to (3) on its surface.

[0043] When manufacturing a skin material 200 having the layer structure shown in Fig. 20, a laminate of a skin layer containing a synthetic resin and a foam layer-forming composition layer containing a synthetic resin, a foaming agent, etc. is formed by a calendaring device or the like, and a base fabric is attached to the foam layer-forming composition layer via an adhesive. Next, the foaming agent is foamed by heating. Next, the skin layer is embossed using an embossing roll or embossing plate having a predetermined concave-convex pattern. This makes it possible to manufacture a skin material 200 having a concave-convex pattern on its surface that satisfies conditions (1) to (3).

[0044] In addition, one method for making the three-dimensional surface roughness of the uneven surface of the skin material 1.637 μm or less is to not form fine unevenness such as pore-like, fiber-like, or hairline-like on the surface.

[0045] The method for producing a skin material according to the present disclosure may include other steps. The other steps may be known steps. For example, the method may include a step of cutting the skin material after embossing into a predetermined shape. EXAMPLES

[0046] The synthetic resin skin material of the present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples.

[0047] (Step I) Formation of the skin material I-(1) Skin material a (PVC leather) Using a calendar device, a laminate was formed of a surface layer made of PVC resin blended with a plasticizer, a stabilizer, a filler, a colorant, etc., and a foam layer-forming composition layer made of PVC resin blended with a foaming agent, a plasticizer, a stabilizer, a filler, a colorant, etc. A knitted fabric was attached to the foam layer-forming composition layer via an adhesive, and the resulting mixture was passed through a heating furnace to foam the foaming agent, thereby forming a foamed resin layer containing bubbles therein, and a skin material a having a thickness of 1.2 mm was obtained.

[0048] I-(2) Skin material b (urethane synthetic leather) A polyurethane resin was diluted with a solvent to prepare a composition for forming a surface layer. The composition for forming a skin layer was applied to the surface of the release paper with a knife coater to form a composition layer for forming a skin layer on the surface of the release paper. A knitted fabric was attached to the layer of the composition for forming a skin layer via an adhesive, and then the resulting mixture was aged and cured to obtain a skin material b having a thickness of 0.9 mm.

[0049] (Step II) Formation of unevenness A predetermined concave-convex pattern was formed on the skin layer side of the skin materials a and b obtained as described above by any one of the following embossing processes. II-(1) Embossing with an embossing roll II-(2) Embossing with an embossing plate

[0050] <Example 1> The concave-convex pattern shown in Figure 1(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0051] <Example 2> The concave-convex pattern shown in FIG. 1(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0052] <Example 3> The concave-convex pattern shown in Figure 2(A) was formed on the skin material a (PVC leather) using an embossing plate.

[0053] <Example 4> The concave-convex pattern shown in FIG. 2(A) was formed on the skin material b (urethane synthetic leather) using an embossing plate.

[0054] <Example 5> The concave-convex pattern shown in Figure 3(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0055] <Example 6> The concave-convex pattern shown in FIG. 3(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0056] <Example 7> The concave-convex pattern shown in Figure 4(A) was formed on the skin material a (PVC leather) using an embossing plate.

[0057] <Example 8> The concave-convex pattern shown in FIG. 4(A) was formed on the skin material b (urethane synthetic leather) using an embossing plate.

[0058] <Example 9> The concave-convex pattern shown in Figure 5(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0059] <Example 10> The concave-convex pattern shown in FIG. 5(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0060] <Example 11> The concave-convex pattern shown in Figure 6(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0061] <Example 12> The concave-convex pattern shown in FIG. 6(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0062] <Example 13> The concave-convex pattern shown in Figure 7(A) was formed on the skin material a (PVC leather) using an embossing plate.

[0063] <Example 14> The concave-convex pattern shown in FIG. 7(A) was formed on the skin material b (urethane synthetic leather) using an embossing plate.

[0064] <Example 15> The concave-convex pattern shown in FIG. 8(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0065] <Example 16> The concave-convex pattern shown in FIG. 8(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0066] <Example 17> The concave-convex pattern shown in FIG. 9(A) was formed on the skin material a (PVC leather) using an embossing plate.

[0067] <Example 18> The concave-convex pattern shown in FIG. 9(A) was formed on the skin material b (urethane synthetic leather) using an embossing plate.

[0068] <Example 19> The concave-convex pattern shown in FIG. 10(A) was formed on the skin material a (PVC leather) using an embossing roll.

[0069] <Example 20> The concave-convex pattern shown in FIG. 10(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0070] <Comparative Example 1> The uneven pattern shown in FIG. 11(A) (conventional uneven pattern) was formed on the skin material a (PVC leather) using an embossing roll.

[0071] <Comparative Example 2> The concave-convex pattern shown in FIG. 11(A) was formed on the skin material b (urethane synthetic leather) using an embossing roll.

[0072] [evaluation] For each of the skin materials after embossing, the shape of the surface irregularities and the three-dimensional surface roughness in a cross section including a line connecting the points where the thickness of the surface irregularities is greatest and the points where the thickness is smallest, i.e., the cross section at observation position D on the plane shown in (A) of each figure, were measured using the device described above, and the dirt wiping ability and designability were also evaluated. In each figure, (B) shows a cross-sectional shape along the measurement position shown in (A), and (C) shows a cross-sectional shape in which the depth (thickness) of the cross-sectional shape shown in (B) is enlarged by 10 times to make the cross-sectional shape at the measurement position easier to understand. For convenience, in each figure, the inclination angle α (α1, α2) of the convex part, the opening length X (X1, X2) of the concave part, and the depth Y (Y1, Y2) of the concave part are shown in the cross-sectional shape of (C) in each figure, but the measurement was performed based on the actual cross-sectional shape shown in (B).

[0073] <Easy to wipe off dirt> (Test Method) 1: Mix 2g of red soil (Kanto Loam layer) with 1.4ml of water to make mud. 2: Rub 0.1g of mud onto the uneven surface of the epidermis layer with your fingers. 3: Gently wipe off the mud that has been rubbed onto the uneven surface of the epidermis layer with a cloth dampened with water.

[0074] (Evaluation method) After the above-mentioned mud test, the color of the surface layer was visually confirmed and evaluated according to the following evaluation criteria. (Evaluation Criteria) A: The color of the epidermis layer of the wiped area is visible. B: The color of the epidermis layer of the wiped area cannot be seen.

[0075] <Design> (Evaluation method) The appearance of the skin material produced in each example was visually observed from a position 50 cm away from the surface of the skin material and evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The appearance exhibited distinctive designs that differed from conventional skin materials. B: Appearance was the same as that of conventional skin materials.

[0076] The results are shown in Tables 1 to 3 below.

[0077] [Table 1]

[0078] [Table 2]

[0079] [Table 3]

[0080] The covering materials of the Examples were all rated higher in terms of ease of wiping off dirt and design than the covering materials of the Comparative Examples. [Explanation of symbols]

[0081] 10, 20 Skin material 12, 22, 32, 42, 52, 62 72A, 72B Convex 14, 24, 54, 64 74A, 74B Recess 100, 200 Skin material 110 Epidermal layer 120 Adhesive layer 130 Base fabric 140 Foam layer

Claims

1. A synthetic resin skin material including a skin layer containing a synthetic resin, the synthetic resin skin material having a concave-convex pattern formed on the surface thereof, the concave-convex shape of the surface in a cross section including a point where the thickness of the concave-convex surface is greatest and a point where the thickness is smallest, satisfies all of the following conditions (1) to (3), and the three-dimensional surface roughness of the surface having the concave-convex surface is 1.637 μm or less: (1) The convex portion has an apex and an inclined portion inclined from the apex toward the bottom of the adjacent concave portion, and is in contact with the apex. Of the two angles formed by the intersection of a line perpendicular to the thickness direction of the skin material and a line along the inclined portion, the angle on the side including the convex portion is 160° to 178°. (2) The opening length of the recess in a direction perpendicular to the thickness direction of the skin is 2 mm to 13 mm. (3) The depth of the recess is 0.1 mm to 0.4 mm.

2. 2. The synthetic resin skin material according to claim 1, wherein the projections and recesses are arranged in a repeated pattern in at least one of the length direction and the width direction of the synthetic resin skin material.

3. 3. The synthetic resin skin material according to claim 2, wherein the projections and recesses are repeatedly arranged in a constant pattern in both the length direction and the width direction of the synthetic resin skin material.

4. 4. The synthetic resin skin material according to claim 1, wherein the projections and recesses are arranged so as to present a geometric pattern over the entire surface of the synthetic resin skin material.

5. A method for producing the synthetic resin skin material according to any one of claims 1 to 4, comprising the steps of: preparing a synthetic resin sheet including a synthetic resin layer for forming the skin layer; a step of embossing the synthetic resin layer using an embossing roll or an embossing plate to form a concave-convex pattern on the surface of the synthetic resin sheet, the concave-convex pattern satisfying all of the conditions (1) to (3) and having a three-dimensional surface roughness of 1.637 μm or less; A method for producing a synthetic resin skin material, comprising:

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