Interior materials for vehicles

Abstract

To provide an interior material for a vehicle, which can be used without losing a material texture or touching of a natural material itself on a design surface while ensuring high shock resistance.SOLUTION: An interior material 20 for a vehicle, which is plate-shaped and which includes a thermoplastic resin, a plant fiber, and a high-strength fiber higher in melting point than the thermoplastic resin and higher in tensile elastic modulus than the plant fiber, comprises: a design side layer 22 constituting a design surface 21A in the vehicle; and an opposite side layer 23 disposed outside the vehicle of the design side layer 22. The content of the plant fiber on the design side layer 22 is higher than that on the opposite side layer, and the content of the high-strength fiber on the opposite side layer 23 is higher than that on the design side layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to interior materials for vehicles.

Background Art

[0002] Fiber boards having a structure in which vegetable fibers are bound by a thermoplastic resin are known (for example, Patent Document 1). This type of fiber board is lightweight and has high rigidity, and is widely used as an interior material for vehicles such as vehicle door trims. In addition, by mixing high-strength fibers together with vegetable fibers, a fiber-containing resin molded body having both rigidity and impact resistance is known (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, there is a desire to utilize the unique texture and feel of natural materials of fiber boards containing vegetable fibers as the design of interior materials for vehicles. However, when high-strength fibers are blended to improve the impact resistance of the fiber board and the blending ratio is increased, the texture and feel of natural materials in terms of design may decrease.

[0005] The technology disclosed in this specification has been achieved in view of the above circumstances, and an object thereof is to provide an interior material for vehicles that can ensure high impact resistance and can be utilized without impairing the unique texture and feel of natural materials in terms of design.

Means for Solving the Problems

[0006] To solve the above problems, the technology disclosed herein provides a vehicle interior material in the form of a plate, comprising a thermoplastic resin, plant fibers, and high-strength fibers having a higher melting point than the thermoplastic resin and a higher tensile modulus than the plant fibers, comprising a design side layer constituting a design surface inside the vehicle interior, and an opposite layer disposed on the outside of the vehicle interior of the design side layer, wherein the proportion of plant fibers in the design side layer is higher than that of the opposite layer, and the proportion of high-strength fibers in the opposite layer is higher than that of the design side layer.

[0007] According to the above configuration, by setting the proportion of plant fibers in the design-side layer higher than that of the opposite layer, rigidity can be ensured in the design-side layer, while preserving the unique texture and feel of natural materials, making it possible to use it as a design surface. On the other hand, by setting the proportion of high-strength fibers in the opposite layer higher than that of the design-side layer, impact resistance for use as an interior material for vehicles can be ensured.

[0008] A molded body made of thermoplastic resin is integrally provided on the opposite side of the design surface, and the opposite layer is composed of an opposite outer layer that constitutes the opposite surface and an opposite inner layer located between the opposite outer layer and the design side layer, and the opposite outer layer may be configured not to contain the high-strength fibers.

[0009] According to the above configuration, the attachment strength of the molded body to the plate-shaped portion of the interior material for vehicles can be increased.

[0010] The opposite inner layer does not necessarily have to contain the plant fibers and the thermoplastic resin. With this configuration, even if the opposite outer layer does not contain high-strength fibers, impact resistance can be ensured for the entire interior material for vehicles by constructing the opposite inner layer with high-strength fibers.

[0011] The aforementioned design surface may be made visible through a translucent protective layer. With such a configuration, the design properties of the design side layer surface can be preserved while protecting the surface of the design side layer. [Effects of the Invention]

[0012] The technology disclosed herein makes it possible to provide interior materials for vehicles that can be used without compromising the unique texture and feel of natural materials in terms of design, while ensuring high impact resistance. [Brief explanation of the drawing]

[0013] [Figure 1] Front view of the door trim of Embodiment 1 [Figure 2] Cross-section of an ornament board [Figure 3] Cross-sectional view of the ornament board of Embodiment 2 [Figure 4] Perspective view of the clip mount on the ornament board. [Modes for carrying out the invention]

[0014] <Embodiment 1> Embodiment 1 will be described with reference to Figures 1 and 2. In each figure, the IN and OUT arrows may indicate the interior (vehicle interior) side and the exterior (vehicle exterior) side. The technology disclosed herein is not limited to the embodiments described below, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0015] The interior material for a vehicle in this embodiment is a door trim 10 for a vehicle, as shown in Figure 1. This door trim 10 constitutes the interior portion of the vehicle's side door and is attached to the door inner panel from the interior side. The door trim 10 is mainly composed of a trim board 11 that is generally rectangular in shape, and in addition to the trim board 11, it includes various functional components such as an inside handle 12, an armrest 13, a door pocket 14, and a speaker grille 15, which are provided on the trim board 11.

[0016] The trim board 11 is formed by assembling a plurality of board members together, and is mainly composed of an upper board 17, a lower board 18, an ornament board 20, an armrest board 19, etc. Among these, the ornament board 20 is disposed between the upper board 17 and the armrest board 19, and extends in the front-rear direction of the vehicle door. The surface (the interior surface of the vehicle cabin) of the ornament board 20 is not covered with a skin material, and is configured to utilize the texture and feel of the base material 21 described later as a design. Note that the board members other than the ornament board 20 are configured such that the surface of the plate-like base material is covered with a skin material.

[0017] The ornament board 20 is made of a plate-like member having a predetermined thickness. As shown in FIG. 2, the ornament board 20 includes a plate-like base material 21, a colored layer 25 made of a non-woven fabric laminated on the interior surface of the vehicle cabin (design surface 21A) of the base material 21, and a transparent or semi-transparent film layer (an example of a protective layer) 26 laminated on the interior surface of the vehicle cabin of the colored layer 25 and the exterior surface of the vehicle cabin (an example of the opposite surface) 21B of the base material 21. The film layer 26 has waterproof and odor-proof properties, protects the surface of the base material 21, and has a function of enhancing the design property of the base material 21 by exhibiting an effect like clear coating. Examples of the film constituting the film layer 26 include a three-layer film of polypropylene-nylon-polypropylene.

[0018] Note that the colored layer 25 and the film layer 26 are extremely thin with respect to the unevenness of the surface of the base material 21, and while utilizing the texture and feel of the surface of the base material 21, the surface of the base material 21 is made visible.

[0019] The base material 21 of the ornament board 20 described above contains vegetable fibers and high-strength fibers, and these fibers are joined to each other or one and the other of these fibers are joined to a thermoplastic resin as a binder.

[0020] Plant fibers are fibers derived from plants. Examples of plant fibers include fibers obtained from various plant bodies such as kenaf, jute, Manila hemp, sisal, ganpi, mitsumata, kozo, banana, pineapple, coconut, corn, sugarcane, bagasse, palm, papyrus, reed, esparto, survivalgrass, wheat, rice, bamboo, various coniferous trees (such as cedar and cypress), broad-leaved trees, and cotton. These plant fibers may be used individually or in combination of two or more. Kenaf fiber is preferred as a plant fiber. Kenaf is an extremely fast-growing annual plant with excellent carbon dioxide absorption capabilities, thus contributing to the reduction of carbon dioxide in the atmosphere and the effective use of forest resources. Furthermore, there are no particular limitations on the part of the plant body used as plant fiber; any part that can be used to extract fibers, such as non-woody parts, stems, roots, leaves, and woody parts, may be used. Furthermore, it is possible to use only a specific area, or to use two or more different areas in combination.

[0021] Thermoplastic resins primarily function as binder resins, and various types of thermoplastic resins can be used. Examples of thermoplastic resins include polyolefin resins, polyester resins, polystyrene, acrylic resins (resins obtained using methacrylate and / or acrylate, etc.), polyamide resins, polycarbonate resins, polyacetal resins, and ABS resins. Among these, polyolefin resins include polypropylene, polyethylene, and ethylene-propylene copolymers (ethylene-propylene block copolymers, ethylene-propylene random copolymers). Polyester resins include aliphatic polyester resins such as polylactic acid, polycaprolactone, and polybutylene succinate, as well as aromatic polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. These thermoplastic resins may be used individually or in combination of two or more.

[0022] The high-strength fiber is made of a resin that has a higher melting point than the thermoplastic resin described above and a higher tensile modulus than the plant-based fiber described above. Preferably, the high-strength fiber has a tensile modulus of 4000 MPa or higher, as measured according to JIS L 1013. Synthetic fibers, particularly thermoplastic resin fibers, can be suitably used as the high-strength fiber. Specifically, examples of high-strength fibers include high-strength polyester fibers (such as high-strength polyethylene terephthalate fibers, referred to as PET fibers), aromatic polyamide fibers (such as meta-aramid fibers), and aliphatic polyamide fibers (such as nylon 66, nylon 6, and nylon 46). Among polyamide fibers, aromatic polyamide fibers with higher heat resistance are more preferable than aliphatic polyamide fibers. Furthermore, from the viewpoint of productivity of the base material 21, PET fibers, which are generally less expensive than polyamide fibers, are particularly preferred. As PET fibers, high-strength fibers with a higher tensile modulus than unreinforced polyethylene terephthalate resin (tensile modulus: approximately 3000-3700 MPa), which are also used in airbags and seat belts, can be suitably used.

[0023] Incidentally, when attempting to impart impact resistance to a rigid base material made of plant fibers and thermoplastic resin by adding high-strength fibers, if the proportion of high-strength fibers in the base material is low, the dispersion state of the high-strength fibers in the base material tends to become uneven, which can lead to variations in the resulting impact resistance. Furthermore, there has been an increasing demand for higher impact resistance in recent years. However, if the proportion of high-strength fibers in the base material increases, there is a problem in terms of design: the unique texture and feel of the natural material obtained from plant fibers is reduced.

[0024] Therefore, in this embodiment, the base material 21 of the ornament board 20 is configured with different proportions of plant fibers, thermoplastic resin, and high-strength fibers in the thickness direction. Specifically, as shown in Figure 2, the base material 21 of this embodiment is configured by laminating two types of layers with different proportions of plant fibers, thermoplastic resin, and high-strength fibers. Hereinafter, the layer located on the vehicle interior side of the two layers will be referred to as the design side layer 22, and the layer laminated on the vehicle exterior side of the design side layer 22 will be referred to as the opposite side layer 23.

[0025] The decorative side layer 22 is a layer that has good aesthetic appeal as the decorative surface 21A of the door trim 10, while ensuring crack resistance (impact resistance) to enhance the safety of occupants, for example, in the event of a side collision, and is a layer with a high content of plant fibers and a low content of high-strength fibers. Preferably, the content ratios of plant fibers, thermoplastic resin, and high-strength fibers in the decorative side layer 22 are 30-50% by mass, 30-55% by mass, and 15-25% by mass, respectively, totaling 100% by mass, based on the total mass of the decorative side layer 22 (the total mass of plant fibers, thermoplastic resin, and high-strength fibers).

[0026] When the plant fiber content is less than 30% by mass, the unique texture and feel of the natural material tend to diminish on the design surface 21A. Furthermore, when the plant fiber content exceeds 50% by mass, the proportion of high-strength fibers decreases, which may result in insufficient impact resistance as the design side layer 22.

[0027] If the thermoplastic resin content falls below 30% by mass, the bonding force between fibers weakens, resulting in reduced rigidity. Conversely, if the thermoplastic resin content exceeds 55% by mass, the proportion of high-strength fibers decreases, which may result in insufficient impact resistance as the design side layer 22.

[0028] Furthermore, in order to ensure impact resistance as the design side layer 22 without impairing the design quality of the design surface 21A (the unique texture and feel of natural materials), it is preferable that the high-strength fibers be 15 to 25% by mass.

[0029] In this embodiment, a specific example of the decorative side layer 22 is that the content ratios of plant fibers (kenaf fibers), thermoplastic resin (polypropylene), and high-strength fibers (PET fibers) are 45% by mass, 40% by mass, and 15% by mass, respectively, based on the total mass of the decorative side layer 22. The basis weight of the decorative side layer 22 is 1200 g / m². 2 It is said that...

[0030] By the way, in order for the base material 21 as a whole to have both sufficient rigidity and impact resistance, it is preferable that the content ratios of plant fibers, thermoplastic resin, and high-strength fibers in the base material 21 be 25-45% by mass, 25-50% by mass, and 20-35% by mass, respectively, totaling 100% by mass, based on the total mass of the base material 21 (the combined mass of plant fibers, thermoplastic resin, and high-strength fibers).

[0031] The opposite layer 23 is a layer set up so that the entire base material 21, including the design side layer 22 described above, satisfies these conditions, and is a layer in which the proportion of high-strength fibers is higher than that of the design side layer 22. In other words, it is a layer with higher impact resistance than the design side layer 22. The proportions of plant fibers, thermoplastic resin, and high-strength fibers in the opposite layer 23 are preferably 5-30% by mass, 15-30% by mass, 45-75% by mass, and 100% by mass in total, relative to the total mass of the opposite layer 23 (the total mass of plant fibers, thermoplastic resin, and high-strength fibers). In particular, it is more preferable to have proportions of 10-25% by mass, 20-25% by mass, and 50-70% by mass, and 100% by mass in total.

[0032] In this embodiment, a specific example of the opposite layer 23 is that the content ratios of plant fibers (kenaf fibers), thermoplastic resin (polypropylene), and high-strength fibers (PET fibers) are 10% by mass, 20% by mass, and 70% by mass, respectively, based on the total mass of the opposite layer 23. The basis weight of the opposite layer 23 is 300 g / m². 2 It is said that...

[0033] Furthermore, the design side layer 22 and the opposite side layer 23 have similar densities, and the ratio of the thicknesses of the design side layer 22 and the opposite side layer 23 is approximately 4:1.

[0034] According to this embodiment, the base material 21 can be made to have sufficient rigidity and impact resistance as a whole, thanks to the design side layer 22 which has relatively high rigidity and the opposite side layer 23 which has relatively high impact resistance. Moreover, since the design side layer 22 contains a high proportion of plant fibers, the unique texture and feel of the natural material possessed by the design side layer 22 can be used as a design element for the ornament board 20.

[0035] Furthermore, by providing an opposite layer 23 in which the proportion of high-strength fibers is higher than the proportion of high-strength fibers in the entire base material 21, the impact resistance required for the base material 21 as a whole can be obtained with a smaller amount of high-strength fibers than when the base material is constructed with a single layer. As a result, the total amount of high-strength fibers can be reduced compared to when it is constructed with a single layer, making it possible to lighten the base material 21 and reduce material costs.

[0036] Furthermore, since the interior surface (design surface 21A) of the base material 21 (design side layer 22) is visible through a translucent or semi-translucent film layer 26, the design of the design side layer 22 can be preserved while protecting the surface of the design side layer 22.

[0037] <Embodiment 2> Embodiment 2 will be described with reference to Figures 1 and 3-4. In this embodiment, a clip seat (an example of a molded body) 28 is provided on the exterior surface of the ornament board 20 (an example of the opposite surface) 21B. The clip seat 28 is formed of a thermoplastic resin such as polypropylene, and as shown in Figure 4, it is provided integrally with the base material 21 in such a way that it protrudes from the exterior surface of the base material 21 21. Note that in Figure 4, the colored layer 25 and the film layer 26 are omitted from the display.

[0038] The clip seat 28 is formed by setting a pre-board, which serves as the base material 21, into a mold and, while it is pressed, injecting molten resin into the clip seat molding space provided in the mold. The ornament board 20 is configured to be attached to the door inner panel (not shown) via a clip attached to this clip seat 28.

[0039] By the way, when the clip seat 28 is integrally provided on the base material 21 by injection molding, if the mounting surface of the base material 21 (exterior surface 21B of the vehicle interior) contains the high-strength fibers described in Embodiment 1, the mounting strength of the clip seat 28 to the base material 21 may decrease.

[0040] Therefore, in this embodiment, the opposite layer 23 described in Embodiment 1 is made into a two-layer structure consisting of an opposite outer layer 23A that constitutes the outer surface 21B of the vehicle interior of the base material 21, and an opposite inner layer 23B located between the opposite outer layer 23A and the design side layer 22. The opposite outer layer 23A is made without high-strength fibers, that is, it is made only of plant fibers and thermoplastic resin. Furthermore, in order to ensure impact resistance, the opposite inner layer 23B is made only of high-strength fibers.

[0041] Specifically, the design side layer 22 is the same as in Embodiment 1 above, and the content ratios of plant fibers, thermoplastic resin, and high-strength fibers in the design side layer 22 are preferably 30-50% by mass, 30-55% by mass, and 15-25% by mass, respectively, with a total of 100% by mass, based on the total mass of the design side layer 22 (the combined mass of plant fibers, thermoplastic resin, and high-strength fibers).

[0042] In this embodiment, a specific example of the decorative side layer 22 is that the content ratios of plant fibers (kenaf fibers), thermoplastic resin (polypropylene), and high-strength fibers (PET fibers) are 45% by mass, 40% by mass, and 15% by mass, respectively, based on the total mass of the decorative side layer 22. The basis weight of the decorative side layer 22 is 1200 g / m². 2 It is said that...

[0043] On the other hand, the proportions of plant fibers, thermoplastic resin, and high-strength fibers in the opposite outer layer 23A are preferably 45-55% by mass, 45-55% by mass, and 0% by mass, respectively, with a total of 100% by mass, based on the total mass of the opposite outer layer 23A.

[0044] Furthermore, it is preferable that the proportions of plant fibers, thermoplastic resin, and high-strength fibers in the opposite inner layer 23B be 0% by mass, 0% by mass, and 100% by mass, respectively, based on the total mass of the opposite inner layer 23B.

[0045] In this embodiment, a specific example of the opposite outer layer 23A is that the content ratios of plant fibers (kenaf fibers), thermoplastic resin (polypropylene), and high-strength fibers (PET fibers) are 50% by mass, 50% by mass, and 0% by mass, respectively, based on the total mass of the opposite outer layer 23A. The basis weight of the opposite outer layer 23A is 200 g / m². 2 It is said that...

[0046] Furthermore, as a specific example of the opposite inner layer 23B in this embodiment, the content ratios of plant fibers (kenaf fibers), thermoplastic resin (polypropylene), and high-strength fibers (PET fibers) are 0% by mass, 0% by mass, and 100% by mass, respectively, relative to the total mass of the opposite inner layer 23B. In addition, the basis weight of the opposite inner layer 23B is 200 g / m². 2 It is said that...

[0047] Furthermore, the design side layer 22, the opposite inner layer 23B, and the opposite outer layer 23A are said to have similar densities to each other, and the ratio of the thicknesses of the design side layer 22, the opposite inner layer 23B, and the opposite outer layer 23A is approximately 6:1:1.

[0048] According to this embodiment, in addition to the same effects as in Embodiment 1, even when the clip seat 28 is integrally provided on the outer surface 21B of the base material 21, the mounting strength of the clip seat 28 to the base material 21 can be increased by making the opposite outer layer 23A not contain high-strength fibers.

[0049] Furthermore, by making the opposite inner layer 23B composed of high-strength fibers and not containing plant fibers or thermoplastic resin, the impact resistance of the opposite layer 23, and consequently the entire base material 21, can be ensured. <Other Embodiments> The technologies disclosed herein are not limited to the embodiments described above in the description and drawings, but also include, for example, the following embodiments.

[0050] (1) In the above embodiment, a door trim as an interior material for a vehicle was used as an example, but the technology disclosed herein is not limited to door trims for vehicles and can be applied to pillar garnishes, ceiling materials, console boxes, dashboards, various instrument panels, deck trims, etc., with various modifications.

[0051] (2) The basis weight of the base material is not limited to the above embodiment and can be changed as appropriate depending on the application.

[0052] (3) The interior material for vehicles may contain other components of the fiber and thermoplastic resin (e.g., colorants, fillers, additives, etc.) as long as it does not impair the purpose of the present invention. [Explanation of Symbols]

[0053] 10: Door trim, 11: Trim board (vehicle interior material), 20: Ornament board (vehicle interior material), 21: Base material, 21A: Design surface, 21B: Exterior surface of the vehicle interior (opposite side), 22: Design side layer, 23: Opposite side layer, 23A: Opposite outer layer, 23B: Opposite inner layer, 25: Coloring layer, 26: Film layer (protective layer), 28: Clip base (molded body)

Claims

1. A vehicle interior material having a plate-like shape and comprising a thermoplastic resin, plant fibers, and high-strength fibers having a higher melting point than the thermoplastic resin and a higher tensile modulus than the plant fibers, It comprises a design side layer that constitutes the design surface inside the vehicle interior, and an opposite layer positioned on the outside of the vehicle interior of the design side layer, An interior material for vehicles, wherein the proportion of plant fibers in the design side layer is higher than that of the opposite layer, and the proportion of high-strength fibers in the opposite layer is higher than that of the design side layer.

2. A molded body made of thermoplastic resin is integrally provided on the opposite side of the design surface. The opposite layer is composed of an opposite outer layer that constitutes the opposite surface and an opposite inner layer located between the opposite outer layer and the design side layer. The vehicle interior material according to claim 1, wherein the opposite outer layer does not contain the high-strength fibers.

3. The vehicle interior material according to claim 2, wherein the opposite inner layer does not contain the plant fibers and the thermoplastic resin.

4. The interior material for a vehicle according to any one of claims 1 to 3, wherein the design surface is visible through a translucent protective layer.

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