Surface covering material

Abstract

A surface covering material 30 is provided with fiber layers 41 composed of a plurality of fibers 42 arranged in a planar shape. The fiber layers 41 are layered in at least 30 layers in the front-back direction. The maximum outer dimensions L1 in the cross section of the fibers 42 constituting the fiber layers 41 is 1-6 μm. With such a configuration, it is possible to provide a surface covering material capable of reflecting light without forming a metal vapor deposition film.

Description

Skin material

[0001] The technology disclosed in this specification relates to a skin material.

[0002] Conventionally, a skin material constituting the surface of a vehicle interior material or the like is known from the following Patent Document 1. The skin material described in Patent Document 1 has a reflective layer made of a metal vapor deposition film. The reflective layer reflects sunlight that has entered the vehicle interior, thereby preventing heat from accumulating in the vehicle interior material. This makes it possible to prevent a temperature rise in the vehicle interior material.

[0003] Japanese Patent Application Laid-Open No. 2004-358664

[0004] The skin material described in Patent Document 1 requires a metal vapor deposition film to be formed in a manner that covers the support layer (fabric or the like), which poses the problem of increased man-hours and costs involved in the formation.

[0005] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a skin material that can reflect light without forming a metal vapor deposition film.

[0006] As a means for solving the above-mentioned problems, the skin material disclosed in this specification is characterized in that it includes a fiber layer composed of a plurality of fibers arranged in a plane, the fiber layers being stacked in 30 or more layers in the front-to-back direction, and the maximum outer dimension of the cross section of the fibers constituting the fiber layers being 1 to 6 μm.

[0007] By constructing a fiber layer using fibers with small maximum cross-sectional dimensions, the fiber arrangement density can be increased, thereby increasing the total surface area (area of ​​the light-reflecting surface) of the fibers in the fiber layer, thereby ensuring reliable light reflection. The inventors of the present application have confirmed that by setting the maximum cross-sectional dimension of the fibers constituting the fiber layer to 6 μm or less, near-infrared rays can be sufficiently reflected, improving heat-shielding performance. However, if the fibers constituting the fiber layer are damaged by friction, the gaps between the fibers constituting the fiber layer become larger, increasing light transmittance, and there is a concern that light reflection performance will decrease. In particular, as in the above configuration, thinner fibers are more susceptible to damage. In the above configuration, by stacking 30 or more fiber layers, even if the fiber layer on the design surface is damaged and light reflection performance is reduced, light reflection performance can be maintained in the remaining fiber layers. Furthermore, by setting the maximum cross-sectional dimension of the fibers to 1 μm or more, fiber strength and durability can be ensured.

[0008] Furthermore, the fibers constituting the fiber layer may have a triangular cross section. If the cross section of the fibers were circular, there would be a concern that light would be reflected in various directions from the surface of the fibers, resulting in light passing through the fiber layer. By making the cross section of the fibers triangular, the surface of the fibers can be made flat, which prevents light from being reflected in various directions from the surface of the fibers and thus prevents light from passing through the fiber layer.

[0009] The fiber layer may be made of a woven fabric, and the density of the warp threads constituting the fiber layer may be 330 threads / inch or more, and the density of the weft threads constituting the fiber layer may be 45 threads / inch or more.

[0010] By forming the fiber layer from a woven fabric, the fibers constituting the fiber layer can be aligned and arranged, resulting in a stronger gloss. Furthermore, by setting the densities of the warp and weft yarns to the above values ​​or more, the fiber density can be ensured, preventing light from passing through the fiber layer and ensuring sufficient light reflecting performance.

[0011] Furthermore, among the plurality of fiber layers, each of the first N fiber layers from the design surface side is subjected to a raising treatment, and when the total number of the fiber layers is X, X-N≧30 can be satisfied.

[0012] By applying a nap-raising treatment to each of the fiber layers arranged on the design surface side, it is possible to soften the feel of the design surface and impart a three-dimensional effect. However, by applying a nap-raising treatment to the fibers, the gaps between the fibers become larger, which increases light transmittance, and there is a concern that the light reflectivity of the fiber layers may decrease. In the above configuration, by including 30 or more fiber layers that have not been subjected to a nap-raising treatment, sufficient light reflectivity can be ensured.

[0013] According to the present invention, it is possible to provide a surface material that is capable of reflecting light without forming a metal vapor deposition film.

[0014] Photographs showing cross sections of the first and second layers of the skin material. A diagram showing a lamp irradiation test method. A graph showing the test results of the lamp irradiation test shown in FIG. 4. A photograph showing a cross section of the first layer in the skin material according to embodiment 2 of the present invention. A photograph showing a cross section of the first layer in the skin material according to a modified example.

[0015] <Embodiment 1> Embodiment 1 of the present invention will be described with reference to Figures 1 to 3. In this embodiment, a skin material used in a vehicle interior material to be installed in a vehicle or the like is exemplified. As shown in Figure 1, vehicle interior material 10 includes a substrate 20 and a skin material 30. The substrate 20 is in the form of a plate and is formed from a synthetic resin material (e.g., a thermoplastic resin such as polypropylene), a mixture of a synthetic resin material and a wood-based material (e.g., natural fibers such as kenaf), or the like.

[0016] Examples of the vehicle interior material 10 include interior materials arranged in locations of a vehicle that are likely to be exposed to sunlight, such as door trim, roof trim, instrument panel, package tray, etc. The skin material 30 includes a first layer 40 that forms the design surface 40A of the skin material 30, and a second layer 50 that is arranged on the substrate 20 side of the first layer 40.

[0017] As shown in FIG. 3 , the first layer 40 includes a fiber layer 41 composed of a plurality of fibers arranged in a plane. Thirty or more fiber layers 41 are stacked in the front-to-back direction (thickness direction) of the skin material 30. FIG. 3 illustrates an example in which 39 fiber layers 41 are stacked. In other words, 39 fibers 42 constituting the fiber layer 41 are aligned in the front-to-back direction, as indicated by the black circles in FIG. 3 . The number of layers of the fiber layer 41 can be changed as appropriate. However, the greater the number of layers, the higher the light reflectivity and strength, but the greater the weight and material costs. Therefore, it is more preferable that the number of layers of the fiber layer 41 be in the range of, for example, 30 to 70 layers.

[0018] The fibers 42 (single fibers) constituting the fiber layer 41 preferably have a triangular cross-sectional shape. The maximum outer dimension L1 (single fiber diameter, see FIG. 2) of the fiber 42 in the cross section is set within the range of 1 to 6 μm. The fiber layer 41 is a woven fabric made of warp and weft yarns composed of the fibers 42. The density of the warp yarns (fibers 42) constituting the fiber layer 41 is preferably set within the range of 330 to 410 yarns / inch, and the density of the weft yarns (fibers 42) constituting the fiber layer 41 is preferably set within the range of 45 to 120 yarns / inch. By setting the densities of the warp and weft yarns within the above ranges, sufficient heat-shielding performance can be achieved. The density of the warp yarns constituting the fiber layer 41 is more preferably set within the range of 360 to 405 yarns / inch, and the density of the weft yarns constituting the fiber layer 41 is more preferably set within the range of 85 to 97 yarns / inch. In this embodiment, the fibers 42 are used in both the warp and weft threads, but the fibers 42 may be included in at least one of the warp and weft threads.

[0019] Various synthetic fibers can be used as the material for the fiber 42, including polyester fibers such as polyethylene terephthalate (PET) fiber, polybutylene terephthalate fiber, polytrimethylene terephthalate fiber, and polylactic acid fiber, polyamide fibers such as polyamide 6 fiber and polyamide 66 fiber, and polyolefin fibers such as polyacrylic fiber and polypropylene fiber. Of these synthetic fibers, polyester fibers, and particularly PET fibers, are preferred from the viewpoints of versatility and cost.

[0020] As a manufacturing method for the fibers 42 constituting the fiber layer 41, for example, as shown in FIG. 2 , a method can be used in which a composite fiber 60 having a circular cross section is split into a plurality of thin fibers 42. More specifically, the composite fiber 60 is formed by melt spinning and includes radial portions 61 extending radially from the center in a cross section, and a plurality of (eight in this embodiment) fibers 42 having a triangular cross section that fills the spaces between the radial portions 61. The radial portions 61 are made of, for example, nylon or polyamide. By subjecting the composite fiber 60 to an alkali treatment, the radial portions 61 are dissolved, leaving only the plurality of fibers 42. The fiber 42 manufactured by this method is sometimes called a split yarn.

[0021] In this embodiment, a woven fabric is formed using warp and weft yarns made of composite fibers 60, and then the woven fabric is subjected to an alkali treatment to dissolve the radial portions 61 and leave only the fibers 42, thereby forming the fiber layer 41. By forming the fibers 42 into a triangular cross-sectional shape, the arrangement density of the fibers 42 can be increased in a composite fiber 60 having a circular cross-sectional shape. In other words, a larger number of fibers 42 can be formed from a single composite fiber 60, thereby increasing the density of the fibers 42. Note that when the composite fiber 60 is used, the densities of the warp and weft yarns described above refer to the densities of the warp and weft yarns before the composite fiber 60 is subjected to the alkali treatment.

[0022] The second layer 50 is a woven fabric formed using warp and weft yarns made of fibers. The material of the fibers constituting the second layer 50 can be the same as that of the fibers 42, but may be a different material. Note that the second layer 50 does not use splitting yarns, and the fibers 51 constituting the second layer 50 have a circular cross-sectional shape as shown in FIG. 3, and the maximum outer dimension (fiber diameter) of the cross-section is set to a value larger than the maximum outer dimension L1 of the fibers 42.

[0023] Next, the effects of this embodiment will be described. In this embodiment, by forming the fiber layer 41 using fibers 42 with a relatively small maximum cross-sectional outer dimension, the arrangement density of the fibers 42 can be increased, and the total surface area (area of ​​the light-reflecting surface) of each fiber 42 in the fiber layer 41 can be increased, thereby ensuring reliable light reflection. The inventors of the present application have confirmed that by setting the maximum cross-sectional outer dimension of the fibers 42 constituting the fiber layer 41 to 6 μm or less, near-infrared rays can be sufficiently reflected, thereby improving heat-shielding performance. Furthermore, since the fiber layer 41 can effectively reflect visible light, a stronger glossiness can be achieved on the design surface 40A.

[0024] The heat-shielding performance of the vehicle interior material 10 of this embodiment was confirmed by carrying out a lamp irradiation test shown in Fig. 4. In this lamp irradiation test, as shown in Fig. 4, a reflector lamp 84 (1000 W / m ２ ) was irradiated onto the vehicle interior material 10, and the temperature was measured with a thermocouple 82 (temperature sensor) disposed on the back surface of the vehicle interior material 10. Note that this test was carried out at room temperature. The measurement results are shown in FIG. 5. In the measurement results of FIG. 5, the horizontal axis represents the time since the light from the reflector lamp 84 was irradiated onto the vehicle interior material 10, and the vertical axis represents the temperature measured by the thermocouple 82. As shown in FIG. 5, in the vehicle interior material 10, even after a sufficient time (for example, 20 minutes) had passed since the light from the reflector lamp 84 was irradiated, the temperature was able to be kept at about 40°C, confirming an excellent heat-shielding effect.

[0025] However, if the fibers 42 constituting the fiber layer 41 are damaged by friction, the gaps between the fibers 42 constituting the fiber layer 41 become larger, increasing light transmittance, and there is a concern that light reflectivity may be reduced. This is particularly true when the fibers 42 are thin, as in the present embodiment. In the above configuration, by stacking 30 or more fiber layers 41, even if the fiber layer 41 on the design surface side is damaged and light reflectivity is reduced, the remaining fiber layers 41 of the first layer 40 closer to the second layer 50 can maintain light reflectivity. Furthermore, by setting the maximum outer dimension of the cross section of the fibers 42 to 1 μm or more, the strength of the fibers 42 can be ensured, thereby ensuring durability.

[0026] Furthermore, the fibers 42 constituting the fiber layer 41 have a triangular cross-section. If the cross-sectional shape of the fibers 42 were circular, there would be a concern that light would be reflected in various directions on the surfaces of the fibers 42, resulting in light passing through the fiber layer 41 (and ultimately the first layer 40). By making the cross-sectional shape of the fibers 42 triangular, the surfaces of the fibers 42 can be made flat, which prevents light from being reflected in various directions on the surfaces of the fibers 42 and prevents light from passing through the fiber layer 41.

[0027] The fiber layer 41 is made of woven fabric, and the density of the warp threads constituting the fiber layer 41 is 330 threads / inch or more, and the density of the weft threads constituting the fiber layer 41 is 45 threads / inch or more. By forming the fiber layer 41 from woven fabric, the fibers 42 constituting the fiber layer 41 can be aligned and arranged, resulting in a stronger glossy appearance. Furthermore, by setting the densities of the warp threads and weft threads to be equal to or greater than the above values, the density of the fibers 42 can be ensured, and light transmission through the fiber layer 41 can be suppressed, ensuring sufficient light reflecting performance.

[0028] Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. 6. The same components as those in the above embodiment are designated by the same reference numerals, and redundant description will be omitted. In this embodiment, the configuration of the first layer of the upholstery material differs from that of the above embodiment. The first layer 140 of this embodiment is brushed from the design surface side (the upper side in FIG. 4). FIG. 6 illustrates a case in which, of the 56 fiber layers 41, each of the first 12 fiber layers 41A from the design surface side (12 fiber layers 41A) is brushed. In other words, the 44th fiber layer 41B arranged on the back side is not brushed.

[0029] The number of layers to be brushed among the plurality of fiber layers 41 can be determined as appropriate, but it is preferable that 30 or more fiber layers 41B are not brushed. In other words, it is preferable that the Nth fiber layer from the design surface side is brushed, and where X is the total number of fiber layers, X-N≧30. From the viewpoint of weight reduction, it is preferable that the total number of fiber layers 41 is 60 or less, and therefore it is preferable that the total number of brushed fiber layers 41A is 30 or less.

[0030] The nap-raising treatment can be performed, for example, by pressing a roller equipped with multiple needles against the surface of the first layer 140 while rotating. As the first layer 140 passes over the surface of the roller, the needles scratch the fibers 42 of the first layer 140, causing the fibers 42 to be partially cut and raised, as shown in FIG. 6 . Note that the number of layers to be nap-raised (the aforementioned N) can be increased by increasing the number of times the first layer 140 passes over the roller. Note that in FIG. 6 , a dashed line L2 is drawn at the boundary between the nap-raised fiber layer 41A and the unpasteurized fiber layer 41B.

[0031] In this embodiment, by applying a nap-raising treatment to each of the fiber layers 41 arranged on the design surface side, it is possible to soften the feel of the design surface and impart a three-dimensional appearance to the first layer 140. However, by applying a nap-raising treatment to the fibers 42, the gaps between the fibers 42 become larger, which increases light transmittance, and there is a concern that the light reflectivity of the fiber layer 41 may decrease. In the above configuration, by providing 30 or more layers of fiber layers 41B that have not been subjected to a nap-raising treatment, sufficient light reflectivity can be ensured.

[0032] Other Embodiments The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings. The following embodiments, for example, are also within the technical scope. (1) The total number of fiber layers 41 and the number of fiber layers 41 that are brushed can be varied as appropriate. Figure 7 illustrates a modified example in which, of the 62 fiber layers 41 that make up the first layer 240 of the covering material, the first 22nd fiber layer 41A from the design surface side are brushed. (2) The cross-sectional shape of the fibers 42 is not limited to a triangular shape and can be varied as appropriate. For example, the cross-sectional shape of the fibers 42 may be circular. When the cross-sectional shape of the fibers 42 is circular, the maximum outer dimension of the cross-section of the fibers 42 is equal to the diameter of the cross-section. (3) While the above embodiment illustrates a woven fiber layer 41, the present invention is not limited to this. The fiber layer 41 may be a fiber aggregate, such as a nonwoven fabric or a knitted fabric. (4) The skin material of this embodiment is not limited to use in vehicle interior materials, and can also be used, for example, as seat covers or sunshades. (5) The skin material of this embodiment can be used in vehicles other than cars, and can also be used for purposes other than vehicles.

[0033] 30...Surface material, 40A...Design surface, 41...Fiber layer, 42...Fiber, L1...Maximum outer dimension

Claims

1. An epidermal material comprising a fiber layer composed of a plurality of fibers arranged in a planar shape, wherein the fiber layer is laminated in 30 or more layers in the front-back direction, and the maximum outer dimension in the cross-section of the fibers constituting the fiber layer is 1 to 6 μm.

2. The epidermal material according to claim 1, wherein the fibers constituting the fiber layer have a triangular cross-sectional shape.

3. The epidermal material according to claim 1 or 2, wherein the fiber layer is composed of a woven fabric, the density of the warp threads constituting the fiber layer is 330 threads / inch or more, and the density of the weft threads constituting the fiber layer is 45 threads / inch or more.

4. Among the plurality of fiber layers, each of the fiber layers from the Nth to the outermost layer on the design surface side is subjected to a raising treatment, and when the total number of the fiber layers is X, X - N ≥ 30. The epidermal material according to claim 1 or 2.

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