Vehicle interior materials and seat back panels

Abstract

The example of the vehicular interior trim according to the present application is multilayer structure including at least a base material and a skin layer. The multilayer structure is configured to satisfy the relationships in the following expressions (1) and (2), where RSm (mm) is the average surface roughness of the base material in the horizontal direction, E1_80is the Young's modulus of the base material at 80°C, d1 (mm) is the thickness of the base material, E2_80 (GPa) is the Young's modulus of the skin layer at 80°C, and d2 (mm) is the thickness of the skin layer. Expression (1): Expression (2):

Description

[Technical Field]

[0001] The present application relates to a vehicle interior material and a seat back panel using the same. [Background technology]

[0002] For example, Patent Document 1 describes a press-molded body that can be used as a seat back for a vehicle. The press-molded body in Patent Document 1 has a surface skin fixed to a nonwoven fabric via an adhesive layer, and Patent Document 1 describes that natural leather, synthetic leather, fabric, or the like can be used as the surface skin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-121551 Summary of the Invention [Problem to be solved by the invention]

[0004] Materials used as vehicle interior materials such as seat back panels are desired to have both strength as an interior material and a luxurious appearance. However, the press-molded body described in Patent Document 1 aims to ensure ease of sewing and strength, but does not focus on improving the luxurious appearance, and in this respect there is room for improvement.

[0005] The present application aims to solve the above-mentioned problems by providing an improved vehicle interior material that achieves both a good appearance and sufficient strength, and a seat back panel formed using the same. [Means for solving the problem]

[0006] One example of a vehicle interior material in the present application is a laminated structure including at least a substrate and a skin layer, which is configured to satisfy the relationships of the following formulas (1) and (2), where RSm (mm) is the average horizontal surface roughness of the substrate, E1_80 is the Young's modulus of the substrate at 80°C, d1 (mm) is the thickness of the substrate, and E2_80 (Gpa) is the Young's modulus of the skin layer at 80°C and d2 (mm) is the thickness. The values 0.15 and 135 in the formulas (1) and (2) are in units of 1 / GPa.

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[0007] A seat back panel according to another aspect of the present application is formed using the vehicle interior material according to any one of the aspects of the present application. [Effects of the Invention]

[0008] According to one example of a vehicle interior material of the present application, the thickness of the surface skin layer is adjusted according to the surface roughness of the substrate, within a range that ensures sufficient strength with the substrate. Therefore, the vehicle interior material can be made to have a good appearance while ensuring sufficient strength. Furthermore, by using a seat back panel formed using this vehicle interior material in a vehicle seat, the interior space of the vehicle can be made to have a luxurious feel. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram schematically illustrating a seat arranged in a vehicle. [Figure 2] 1 is a diagram schematically showing a cross-sectional configuration of a vehicle interior material according to a first embodiment of the present application. [Figure 3] FIG. 3 is a diagram showing an outline of the relationship between the average surface roughness (mm) in the horizontal direction of the substrate of the vehicle interior material according to the first embodiment of the present application and the thickness (mm) of the skin layer. [Figure 4]FIG. 3 is a diagram showing the relationship between the height of the irregularities in the vehicle interior material according to the first embodiment of the present application and the ratio of the average horizontal surface roughness of the substrate to the thickness of the skin layer. [Figure 5] FIG. 1 is a diagram showing a method for calculating the average surface roughness RSm in the horizontal direction of a substrate. [Figure 6] Specific sample examples of the vehicle interior material according to the first embodiment of the present application will be shown. [Figure 7] FIG. 10 is a diagram schematically showing a cross-sectional configuration of a vehicle interior material according to a third embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the vehicle interior material according to the present application will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and the description thereof will be simplified or omitted.

[0011] Embodiment 1 FIG. 1 is a diagram showing an example of a seat arranged in a vehicle. A vehicle interior material 10 according to this embodiment is used, for example, as shown in FIG. 1, as a material for a seat back panel 2 of the vehicle seat 1. The seat back panel 2 is located in a conspicuous location, particularly in front of passengers sitting in the rear seats, and occupies a large area in the vehicle interior. Therefore, by applying the vehicle interior material 10 according to this embodiment to the seat back panel 2, the exterior appearance of the vehicle interior space can be effectively made luxurious.

[0012] However, the vehicle interior material 10 can be suitably used for other parts installed inside a vehicle, particularly parts that are likely to be touched by people or that are easily visible to people. Specifically, the vehicle interior material 10 can be used as a material that constitutes the whole or part of, for example, a dashboard, an instrument panel, a door trim, a pillar trim, a rear parcel shelf, etc., in addition to the seat back panel.

[0013] Fig. 2 is a diagram showing a cross-sectional configuration of a vehicle interior material according to the present embodiment. As shown in Fig. 2, the vehicle interior material 10 is a laminated structure in which a base material 11 and a surface layer 12 are bonded together.

[0014] The substrate 11 is made of a relatively light material whose composition is adjusted to ensure the necessary rigidity, and the substrate 11 ensures sufficient strength of the vehicle interior part. The substrate 11 is formed using a material that is lighter (has a lower density) than at least the skin layer 12. Specifically, the substrate 11 may be made of, for example, fiber, felt such as compressed felt and knitted felt, or a resin foam such as urethane foam, or a hollow resin structure (e.g., a honeycomb structure). The substrate 11 may also be made of a laminate of felt and resin.

[0015] The surface layer 12 is made of, for example, synthetic leather containing PVC (polyvinyl chloride). Synthetic leather containing PVC includes synthetic leather made only of PVC and synthetic leather whose main component is PVC. Examples of synthetic leather whose main component is PVC include synthetic leather in which a resin such as nylon or polyurethane is applied to the surface of PVC. The surface layer 12 may also be made of synthetic leather containing other materials such as PP (polypropylene), fibers such as nonwoven fabric and woven fabric, and natural leather. Using these materials can give the vehicle interior material 10 a luxurious appearance.

[0016] 3 is a diagram showing an outline of the relationship between the average surface roughness RSm (mm) in the horizontal direction of the substrate 11 of the vehicle interior material 10 and the thickness d2 (mm) of the skin layer 12. In FIG. 3, the vertical axis represents the average surface roughness RSm in the horizontal direction of the substrate 11, and the horizontal axis represents the thickness d2 of the skin layer 12 relative to the temperature 80°C of the material constituting the skin layer 12. ℃3. In the following embodiments, the average surface roughness of the substrate 11 in the horizontal direction is also referred to simply as the "roughness average." In the vehicle interior material 10 of this embodiment, the relationship between the roughness average RSm and the thickness d2 of the skin layer 12 is adjusted so that the vehicle interior material 10 is included in the region between the solid lines A and B in FIG.

[0017] 3 shows the relationship between the roughness average RSm, which is set in consideration of the allowable weight, and the thickness d2 of the skin layer 12. If the thickness d2 of the skin layer 12 is excessively thick relative to the substrate 11, the smooth appearance can be ensured, but the overall thickness increases, resulting in an increase in the weight of the component formed from the vehicle interior material 10. In the first embodiment, the solid line A, which represents the lower limit, is determined in consideration of the thickness and weight of conventional PP, so that the vehicle interior material 10 is at least lighter than an interior material made of PP.

[0018] The solid line B in FIG. 3 shows the relationship between the average roughness RSm, which is set in consideration of the target roughness of the exterior of the vehicle interior material 10 in the first embodiment, and the thickness d2 of the skin layer 12. Both the surface roughness of the substrate 11 and the thickness of the skin layer 12 affect the magnitude of the irregularities that appear on the exterior of the vehicle interior material 10. To ensure the surface smoothness of the vehicle interior material 10, the larger the average roughness RSm, the greater the thickness d2 of the skin layer 12 must be. On the side where the average roughness RSm is larger than the solid line B in FIG. 3, the roughness of the substrate 11 cannot be sufficiently hidden by the skin layer 12, and the vehicle interior material 10 has noticeable irregularities on the exterior, resulting in a lack of a luxurious feel. Therefore, the vehicle interior material 10 in this embodiment is set so that the ratio of the average roughness RSm is smaller than that of the solid line B.

[0019] 4 is a diagram showing the relationship between the average height Rz of the irregularities on the surface of the vehicle interior material 10 and the ratio of the average roughness RSm of the base material 11 to the thickness d2×80°C Young's modulus E2_80 of the skin layer. As shown in FIG. 4, in the first embodiment, the target is to make the average height Rz (mm) of the irregularities on the surface of the vehicle interior material 10 smaller than 0.04 (mm). In response to this target, the upper limit of the ratio of the average roughness to the thickness of the skin layer 12 (α2=RSm / (d2×E2_80)) is set to 135.

[0020] Specifically, the vehicle interior material 10 of this embodiment is configured so that the roughness average RSm (mm) and the thickness d2 (mm) of the skin layer 12 satisfy the relationship of the following formula (3). The values 0.15 and 135 in formula (3) are in units of 1 / GPa. This allows the weight to be kept within an acceptable range while still ensuring a sufficiently smooth surface.

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[0021] The Young's modulus E2_80 at 80°C of the skin material of the skin layer 12 is used because it corresponds to the maximum temperature of 80°C in the thermal cycle test. By specifying the thickness d2 when the skin is at its softest, it is possible to maintain sufficient surface smoothness even in the most severe high-temperature environment. Furthermore, if the skin layer 12 is a hollow structure, the Young's modulus may be anisotropic. In such cases, the Young's modulus in one of the different directions is used.

[0022] The roughness average RSm used in each formula is a value calculated based on the definition specified in "JIS B 0601 (ISO 4287)." Fig. 5 is a diagram showing a method for calculating the roughness average RSm of the substrate 11. As shown in Fig. 5, the roughness average RSm is calculated by the following formula (4).

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[0023] The roughness average RSm is a value that indicates the average of the lengths Xsi of the profile curve elements over the reference length. The peaks and valleys that make up the profile elements here have minimum heights and lengths, and any peaks or valleys whose height or depth is 10% or less of the maximum height, or whose length is 1% or less of the length of the calculation block, are considered noise and are treated as part of the peaks that follow.

[0024] Conventional vehicle seat back panels are known to be formed by injection molding PP (polypropylene). However, parts made from PP have a hard feel and a rough surface. Therefore, when PP is widely used as a vehicle interior material and the number of exposed PP parts inside the vehicle increases, the luxury feel of the vehicle interior space is diminished. Furthermore, when relatively large parts such as seat backs are made from PP, a certain thickness is required, making them heavy. However, due to the need to ensure the strength and shape of the parts, it is not possible to simply reduce the thickness of the PP plate to reduce weight. Typically, to achieve both weight reduction and strength in PP parts, measures such as adding multiple ribs to the inside of the parts are taken, but there are limits to how much weight can be reduced.

[0025] In contrast, in the vehicle interior material 10 of this embodiment, the substrate 11 is made of a light material that ensures strength, and the overall weight is kept within an allowable range while the surface of the substrate 11 is covered with a skin layer 12 of a sufficient thickness according to the roughness average RSm of the substrate 11. As a result, the vehicle interior material 10 is lightweight, has a good appearance, and ensures sufficient strength.

[0026] Fig. 6 shows a specific sample example of a vehicle interior material 10 according to this embodiment. Specific examples of this embodiment will be described below with reference to Fig. 6. Note that the top row of the table in Fig. 6 shows values for an interior material made of a single layer of PP as a comparative example.

[0027] Example 1 Sample 1 is a vehicle interior material 10 that uses felt with an average roughness RSm = 0.62 (mm) as the substrate 11 and PP with a thickness d2 = 2.5 (mm) as the skin layer 12. The Young's modulus E2_80 of the skin layer 12 is 1520 (MPa). α1 = RSm / (E2_80 × d2) of Sample 1 is 0.163, and Sample 1 is a vehicle interior material 10 that satisfies formula (3). As described above, in formula (3), the Young's modulus is expressed in units of "GPa" (in the case of Sample 1, E2_80=1.520), and the unit of α1 is "1 / GPa."

[0028] Example 2. Sample 2 is a vehicle interior material 10 that uses felt with an average roughness RSm = 0.905 (mm) as the substrate 11 and PVC with a thickness d2 = 1.22 (mm) as the skin layer 12. The Young's modulus E2_80 of the skin layer 12 is 6.3 (MPa). α1 = RSm / (E2_80 × d2) of Sample 2 is 124.2, and Sample 2 is a vehicle interior material 10 that satisfies the relationship of equation (3). As described above, in the formula (3), the Young's modulus is expressed in units of "GPa" (in the case of Sample 2, E2_80=0.0063), and the unit of α1 is "1 / GPa."

[0029] Example 3 Sample 3 is a vehicle interior material 10 that uses felt with an average roughness RSm = 0.62 (mm) as the substrate 11 and fiber with a thickness d2 = 0.42 (mm) as the skin layer 12. The Young's modulus E2_80 of the skin layer 12 is 107.5 (MPa). α1 = RSm / (E2_80 × d2) of Sample 3 is 13.73, and Sample 3 is a vehicle interior material 10 that satisfies the relationship of formula (3). As described above, in the formula (3), the Young's modulus is expressed in units of "GPa" (in the case of Sample 3, E2_80=0.1075), and the unit of α1 is "1 / GPa."

[0030] Example 4. Sample 5 is a vehicle interior material 10 that uses urethane foam with an average roughness RSm = 1.15 (mm) as the base material 11 and PVC with a thickness d2 = 1.22 (mm) as the skin layer 12. The Young's modulus E2_80 of the skin layer 12 is 6.3 (MPa). α1 = RSm / (E2_80 × d2) of Sample 5 is 121.2, and Sample 5 is a vehicle interior material 10 that satisfies the relationship of formula (3). As described above, in the formula (3), the Young's modulus is expressed in units of "GPa" (in the case of Sample 5, E2_80=0.0063), and the unit of α1 is "1 / GPa."

[0031] Sample 4 is a vehicle interior material 10 that uses felt with an average roughness RSm of 1.22 (mm) as the substrate 11 and PVC with a thickness d2 of 1.11 (mm) as the skin layer 12. The Young's modulus E2_80 of the skin layer 12 is 7.6 (MPa). α1=RSm / (E2_80×d2) of Sample 4 is 160, and Sample 4 does not satisfy the relationship of formula (3), and does not correspond to the vehicle interior material 10 of this embodiment. As described above, in the formula (3), the Young's modulus is expressed in units of "GPa" (in the case of Sample 4, E2_80=0.0076), and the unit of α1 is "1 / GPa."

[0032] Embodiment 2 The vehicle interior material 10 of the second embodiment is a laminated structure in which a base material 11 having a thickness d1 and a skin layer 12 having a thickness d2 are laminated together, similar to the vehicle interior material 10 of the first embodiment. In the first embodiment, the relationship between the thickness d2 of the skin layer 12 and the roughness average RSm of the base material 11 is specified, whereas in the vehicle interior material 10 of the second embodiment, the relationship between the overall thickness (d1 and d2) and the roughness average RSm of the base material 11 is specified.

[0033] Specifically, in the vehicle interior material 10 of the second embodiment, the relationship between the roughness average RSm of the base material 11 and the thicknesses (d1 and d2) of the layers is defined as in the following formula (5). The values 0.15 and 135 in formula (5) are in units of 1 / GPa.

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[0034] The substrate 11 and the skin layer 12 of the vehicle interior material 10 are essential components, and therefore, the thicknesses d1 and d2 are at least greater than 0. Furthermore, E1_80 and E2_80 are the Young's moduli of the substrate 11 and the skin layer 12 at 80°C, respectively. As explained in the first embodiment, when the substrate 11 or the skin layer 12 is a hollow structure or the like, the Young's modulus may be anisotropic. In that case, the Young's modulus in one of the different directions is used.

[0035] The vehicle interior material 10 of the second embodiment is the same as that of the first embodiment except that the substrate 11 and the skin layer 12 satisfy the relationship of the above formula (5), and therefore the explanations of the constituent materials of each layer and the intended uses, etc., explained in the first embodiment also apply directly to the vehicle interior material 10 of the second embodiment. Even when the relationship between the substrate 11 and the skin layer 12 is specified as in formula (5), it is possible to obtain a vehicle interior material 10 that has a good appearance and is lightweight, just like the first embodiment.

[0036] Embodiment 3 Fig. 7 is a diagram showing a schematic configuration of a vehicle interior material 30 according to the third embodiment. As shown in Fig. 7, the vehicle interior material 30 has an intermediate layer 13 between a substrate 11 and a skin layer 12. The intermediate layer 13 functions to bond the substrate 11 and the skin layer 12 and to improve the adhesion of the vehicle interior material 30. 3 The intermediate layer 13 is disposed to reinforce the outer periphery of the inner periphery of the frame 0. The intermediate layer 13 is made of nonwoven fabric, fiber, PP, or the like.

[0037] Assuming that the thickness of the skin layer 12 is d2, the thickness of n-layered intermediate layers 13 (n is a natural number greater than or equal to 1) is dMn (mm), the Young's modulus of the skin layer 12 at 80°C is E2_80, and the Young's modulus of the n-layered intermediate layers 13 at 80°C is EMn_80 (Gpa), the vehicle interior material 30 of embodiment 3 is configured so that the roughness average RSm of the base material 11, the thickness d2 of the intermediate layer 13, and the thickness d2 of the skin layer 12 satisfy the relationship of the following formula (6). The values 0.15 and 135 in formula (6) are in units of 1 / GPa.

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[0038] As in the case of the substrate 11 and the surface layer 12, if the intermediate layer 13 has a hollow structure or the like and has anisotropy in its Young's modulus, the Young's modulus in any of the different directions is E Used as Mi_80.

[0039] When the vehicle interior material 30 is configured to have an intermediate layer 13, by taking into account the thickness d3 of the intermediate layer 13 and the thickness d2 of the skin layer 12 as shown in the above formula (6), it is possible to obtain a vehicle interior material 30 that has a good appearance, is lightweight, and has high strength, as in embodiments 1 and 2.

[0040] The vehicle interior material 30 may be configured so that the roughness average RSm of the substrate 11 and the thickness d2 of the skin layer 12 satisfy the relationship of formula (3), without including the thickness d3 of the intermediate layer 13. By configuring the vehicle interior material 30 to satisfy the relationship of formula (3), the vehicle interior material 30 can be made to have a good appearance, be lightweight, and have high strength, as in the first embodiment.

[0041] Alternatively, the vehicle interior material 30 may be one in which the thicknesses dMn of the n intermediate layers 13, the thickness d2 of the skin layers 12, and the thickness d1 of the base material 11 are all taken into consideration, and the thicknesses and the roughness average RSm are adjusted to satisfy the relationship of the following formula (7). The values 0.15 and 135 in formula (7) are in units of 1 / GPa.

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[0042] Other embodiments Here, when the vehicle interior material 10 is composed of two layers, a substrate 11 and a skin layer 12, the thickness of the substrate 11 is d1, the thickness of the skin layer 12 is d2, and α1 and α2 are the values shown in the following equations (8) and (9) corresponding to the above equations (3) and (5). The units of α1 and α2 in formulas (8) and (9) are "1 / GPa."

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[0043] In the first embodiment, a case where α1 satisfies the relationship of formula (3) (0.15<α<135) will be described, and in the second embodiment, a case where α2 satisfies the relationship of formula (5) (0.15<α<135) will be described. α2However, the vehicle interior material 10 may be one in which the relationship between the substrate 11 and the skin layer 12 is adjusted so as to at least satisfy the relationships 0.15<α1 and α2<135.

[0044] Furthermore, it is more preferable that the base material 11 and the skin layer 12 of the vehicle interior material 10 are adjusted so as to satisfy the relationships 0.15<α2 and α1<135. Since α1>α2, by making 0.15<α2 and α1<135, the relationship 0.15<α2<α1<135 is established. Therefore, it is possible to obtain a vehicle interior material 10 with a better appearance that satisfies both the relationship of formula (3) in the first embodiment and the relationship of formula (5) in the second embodiment.

[0045] Furthermore, when the vehicle interior material 30 is composed of three or more layers, namely, a substrate 11, a skin layer 12, and n intermediate layers 13, the thickness of the substrate 11 is defined as d1, the thickness of the skin layer 12 as d2, and the thickness of the intermediate layer 13 as dMn, α1 is defined as in the above formula (8) corresponding to the above formula (3), and α3 and α4 are defined as the values shown in the following formulas (10) and (11), respectively, corresponding to the formulas (6) and (7) described in embodiment 3. The units of α3 and α4 in equations (10) and (11) are "1 / GPa."

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[0046] In the third embodiment, formula (6) has been described for the case where the roughness RSm of the substrate and the thicknesses of the skin layer 12 and intermediate layer 13 are adjusted to satisfy the relationship of 0.15<α3<135. However, the vehicle interior material 30 only needs to have each of the layers 11 to 13 adjusted to satisfy at least the relationships of 0.15<α1 and α4<135. The values 0.15 and 135 are in units of 1 / GPa.

[0047] Furthermore, the vehicle interior material 30 may be adjusted to satisfy, for example, the relationship 0.15<α1 and α3<135, or may be adjusted to satisfy the relationship 0.15<α3 and α4<135. The values 0.15 and 135 are in units of 1 / GPa.

[0048] More preferably, each of the layers 11 to 13 is adjusted to satisfy the relationships 0.15<α4 and α1<135. Since α1>α3>α4, by making 0.15<α4 and α1<135, the relationship 0.15<α4<α3<α1<135 is established, and it is possible to obtain a vehicle interior material 30 with a better appearance that satisfies both of the formulas (6) and (7) of embodiment (3). The values 0.15 and 135 are in units of 1 / GPa.

[0049] In the above embodiments, when the number, quantity, amount, range, etc. of each element is mentioned, the present invention is not limited to the mentioned numbers unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the embodiments are not necessarily essential to the present invention unless otherwise specified or clearly specified in principle. [Explanation of symbols]

[0050] 1 sheet 2 Seat back panel 10, 30 Vehicle interior materials 11 Base material 12 Epidermal layer 13 Middle class

Claims

1. A laminated structure including at least a substrate and a surface layer, The average surface roughness of the substrate in the horizontal direction is RSm (mm), the Young's modulus of the substrate at 80°C is E1_80 (Gpa), and the thickness of the substrate is d1 (mm), When the Young's modulus of the skin layer at 80°C is E2_80 (Gpa) and the thickness of the skin layer is d2 (mm), A vehicle interior material characterized in that the value calculated by the following formula (1) is greater than 0.15 (1 / GPa) and the value calculated by the following formula (2) is less than 135 (1 / GPa): [Equation 1] [Equation 2]

2. 2. The vehicle interior material according to claim 1, further comprising a structure in which a value calculated by the following formula (3) is greater than 0.15 (1 / GPa): [Equation 3]

3. A laminated structure including at least a substrate and a surface layer, The average surface roughness of the substrate in the horizontal direction is RSm (mm), When the Young's modulus of the skin layer at 80°C is E2_80 (Gpa) and the thickness of the skin layer is d2 (mm), A vehicle interior material characterized in that the value calculated by the following formula (4) is greater than 0.15 (1 / GPa) and less than 135 (1 / GPa): [Equation 4]

4. 4. The vehicle interior material according to claim 1, wherein the substrate is made of a fiber, a felt, a foamed resin, or a hollow resin structure.

5. 5. The vehicle interior material according to claim 1, wherein the surface layer is made of synthetic leather, nonwoven fabric, woven fabric, or natural leather.

6. 6. The vehicle interior material according to claim 1, further comprising a single or multiple intermediate layer between the surface layer and the substrate.

7. The vehicle interior material according to claim 6, wherein the intermediate layer includes a layer made of any one of a nonwoven fabric, a resin sheet, a fiber, and polypropylene.

8. When the intermediate layer is an n-layer, 8. The vehicle interior material according to claim 6 or 7, characterized in that the value calculated by the following formula (5) is greater than 0.15 (1 / GPa) and less than 135 (1 / GPa), where EMn_80 (Gpa) is the Young's modulus of the intermediate layer at 80°C and dMn (mm) is the thickness of the intermediate layer: [Equation 5]

9. When the intermediate layer is an n-layer, 8. The vehicle interior material according to claim 6 or 7, wherein the intermediate layer is configured so that a value calculated by the following formula (6) is greater than 0.15 (1 / GPa) and less than 135 (1 / GPa), where EMn_80 (Gpa) has a Young's modulus at 80°C and dMn (mm) has a thickness: [Equation 6]

10. A seat back panel formed using the vehicle interior material according to any one of claims 1 to 9.

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