Automotive ceiling materials

Abstract

To provide an automobile ceiling material that is both easy to recycle and lightweight, in which a glass fiber sheet used as a reinforcing material is replaced with a film having a surface roughness similar to that of the glass fiber sheet. [Solution] An automobile ceiling material comprising a laminate formed by laminating a fiber material / a film / a porous body / a film in this order, wherein the fiber material, the film, and the porous body are made of a thermoplastic resin, and the film has an embossed pattern with an arithmetic mean roughness Sa of 100 μm or more.

Description

[Technical Field]

[0001] The present invention relates to an easily recyclable automobile ceiling material in which the glass fiber sheet used as a reinforcing material is replaced with a film having a surface roughness similar to that of the glass fiber sheet, and to a method for manufacturing the same. [Background technology]

[0002] In response to growing societal demand for a circular economy, the automotive industry is increasingly using recycled materials, but at the same time, there is also a growing need to make automotive components, including interior and exterior materials, more easily recyclable.

[0003] In response to this need, material manufacturers are considering replacing existing difficult-to-recycle materials with easily recyclable materials. For example, in the case of automobile interior materials, efforts have been made to replace glass fiber sheets, one of the components that are difficult to recycle, with easily recyclable materials.

[0004] Glass fiber sheets function as a reinforcing material in automotive headliners, thereby preventing sagging of the headliner due to the weight of the headliner itself. Therefore, when replacing glass fiber sheets, it is necessary to search for a material with bending resistance properties equivalent to those of glass fiber sheets. Patent Document 1 therefore discloses an invention in which glass fiber sheets are replaced with polyester sheets that have been strengthened by promoting crystallization using a crystal nucleating agent. Patent Document 2 also focuses on the fact that uniaxially stretched films exhibit high strength against deformation in the stretching direction, and discloses an invention in which glass fiber sheets are replaced with polyester films that have been strengthened by uniaxial stretching, laminated together so that the stretching directions of adjacent films are different. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-214293 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-254557 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the invention of Patent Document 1 requires the addition of a large amount of talc to promote crystallization, but because talc is also an inorganic material, there is a problem that the improvement in recyclability is insufficient.Furthermore, the invention of Patent Document 2 involves laminating multiple stretched films, which increases the basis weight of the laminated film itself, which is not a desirable solution from the perspective of recent efforts to reduce the weight of automobiles.

[0007] In view of the above problems, the present invention aims to provide an automobile ceiling material that is both easy to recycle and lightweight by replacing the glass fiber sheet with a film having a basis weight similar to that of the glass fiber sheet. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an automobile ceiling material having the following configuration. (1) An automobile ceiling material including a laminate formed by laminating a fiber material / a first film / a porous body / a second film in this order, wherein the fiber material, the first film, the porous body, and the second film are all made of a thermoplastic resin, and the first film and the second film each have an embossed pattern with an arithmetic mean roughness Sa of 100 μm or more. (2) The automobile ceiling material according to (1), wherein the first film and the second film are both polyester films. (3) The automobile ceiling material according to (2), wherein the fiber material and the porous body are both made of polyester. [Effects of the Invention]

[0009] According to the present invention, by replacing a glass fiber sheet with a film having a basis weight similar to that of the glass fiber sheet, it is possible to provide an automobile ceiling material that is both easy to recycle and lightweight. DETAILED DESCRIPTION OF THE INVENTION

[0010] The automobile ceiling material of the present invention is described in detail below. The automobile ceiling material of the present invention includes a laminate formed by laminating a fiber material / a first film / a porous body / a second film in this order, and the fiber material, the first film, the porous body, and the second film are all made of a thermoplastic resin. The film in the laminate of the present invention has an embossed pattern with an arithmetic mean roughness Sa of 100 μm or more. Because the fiber material, the film, and the porous body are made of a thermoplastic resin, the used automobile ceiling material can be crushed and re-pelletized, or returned to its monomer unit by chemical recycling, thereby allowing it to be reused as a raw material for the fiber material, the film, or the porous body. Furthermore, the film having such an embossed pattern can exhibit high resistance to forces applied perpendicular to the film surface. The detailed mechanism is as follows.

[0011] The embossed areas of embossed film have areas that are deformed perpendicular to the film surface, and in these areas, forces applied perpendicular to the film surface act to stretch or compress the film. With unembossed film, forces applied perpendicular to the film surface cause bending deformation, but with embossed film, bending deformation and stretching or compression deformation coexist, and this synergistic effect allows the embossed film as a whole to exhibit high resistance to forces applied perpendicular to the film surface, on a level comparable to that of glass fiber sheeting. It is believed that this results in reduced sagging of automotive headliners using embossed film.

[0012] <First film and second film> The automobile ceiling material of the present invention has a first film and a second film as reinforcing materials. First, the first film will be described. The first film provided in the automobile ceiling material of the present invention is made of a thermoplastic resin. The type of thermoplastic resin constituting the first film is not particularly limited, and examples include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; and polyamides such as 6-nylon and 6,6-nylon. Among these, polyesters are preferred from the viewpoint of excellent strength and strength stability when humidified, and polyethylene terephthalate is particularly preferred from the viewpoint of the ability to further increase the strength of the film by biaxial stretching, etc.

[0013] The first film may be in the form of a non-stretched film or a stretched film, but a stretched film is preferred from the viewpoint of achieving the high strength characteristics required for automobile ceiling materials, and a biaxially stretched film is particularly preferred from the viewpoint of minimizing variations in strength in the in-plane direction.

[0014] The basis weight (1 m ) of the first film provided in the automobile ceiling material of the present invention 2 Weight per unit is 50-200g / m 2 The basis weight is preferably 50 g / m 2 By satisfying the above conditions, the film is given stiffness, and when the automobile ceiling material of the present invention is installed on the ceiling of an automobile, sagging due to its own weight can be suppressed. 2 By setting the film weight as follows, a lightweight automobile ceiling material can be obtained. From the viewpoint of achieving both suppression of sagging and lightness, the film weight is set to 100 to 200 g / m 2 It is more preferable that:

[0015] It is important that the first film included in the automotive ceiling material of the present invention has an arithmetic mean roughness Sa of 100 μm or more, from the viewpoint of being able to exhibit high resistance to forces applied in a direction perpendicular to the film surface. From the viewpoint of being able to exhibit even higher resistance, the arithmetic mean roughness is more preferably 150 μm or more. The arithmetic mean roughness Sa can be adjusted to a value within the above range by changing the shape of the embossing roll or adjusting the temperature and speed during embossing. On the other hand, the upper limit of the arithmetic mean roughness of the first film is not particularly limited, but is preferably 500 μm or less, from the viewpoint that if the arithmetic mean roughness is too large, the embossed portion becomes too thin and is unable to exhibit sufficient resistance to forces applied in a direction perpendicular to the film surface.

[0016] Here, the explanation of the second film provided in the automobile ceiling material of the present invention is omitted because it is the same as the explanation of the first film described above.

[0017] The first film and the second film may be the same or different. From the viewpoint of improving productivity of the automobile ceiling material of the present invention, it is preferable that the first film and the second film are the same.

[0018] <Porous body> The automobile ceiling material of the present invention has a porous body as a heat insulating material. The porous body is made of a thermoplastic resin from the viewpoint of recyclability. The types of thermoplastic resins constituting the porous body include the same as those of the film described above. From the viewpoint of further improving recyclability by unifying the materials constituting the automobile ceiling material into a single material, polyester is preferred, and polyethylene terephthalate is particularly preferred. Here, since the fiber material, first film, porous body, and second film contained in the automobile ceiling material of the present invention are all made of a thermoplastic resin, it can be said that the materials constituting the automobile ceiling material are all made of a single material (thermoplastic resin). Furthermore, since the fiber material, first film, porous body, and second film contained in the automobile ceiling material of the present invention are all made of polyester, it can be said that the materials constituting the automobile ceiling material are all made of a single material (polyester).

[0019] The porous body of the present invention also functions as a heat insulating layer in automobile ceiling materials. 2 ·K / W or more is preferable.

[0020] The specific form of the porous body of the present invention is not particularly limited as long as it satisfies the above-mentioned thermal resistance, and may be any of a foam, a woven fabric, a nonwoven fabric, and a sintered body.

[0021] <Textile materials> The automobile ceiling material of the present invention has a fiber material as a skin material. The fiber material of the present invention, like the film and porous body, is made of a thermoplastic resin from the viewpoint of recyclability. The thermoplastic resin constituting the fiber material may be the same as that of the film. From the viewpoint of further improving recyclability by unifying the material constituting the automobile ceiling material into a single material, polyester is preferred, and polyethylene terephthalate is particularly preferred.

[0022] Furthermore, the specific form of the fiber material of the present invention is preferably any one of woven fabric, knitted fabric, and nonwoven fabric, since it is placed in the outermost layer of the interior side of an automobile ceiling material and therefore requires a smooth feel. [Example]

[0023] The present invention will be described in more detail below with reference to examples. The property values ​​shown in the examples were measured by the following methods.

[0024] A. Arithmetic mean roughness Sa of the first film and the second film The arithmetic mean surface roughness Sa (um) of the embossed film surface was measured using a one-shot 3D shape measuring instrument "VR-3000" (manufactured by Keyence Corporation). The specific measurement conditions are as follows:

[0025] ·Magnification: 12x ·Analysis area: Entire area of ​​measurement surface Cutoff wavelength: None If the film was transparent, the film surface was painted with a 3D scanning spray before measurement.

[0026] B. Basis weight of the first film, the second film and the glass fiber sheet Ten 10cm square test pieces were cut out from the film or glass fiber sheet, and the ten test pieces were stacked and weighed. The weight obtained was multiplied by 10 to determine the basis weight of the film (g / m 2 ) was decided.

[0027] C. Bending resistance of the first film, the second film, and the glass fiber sheet Measurements were performed with reference to JIS-K7171:2016. Specifically, a 10 cm square test piece cut from the film was placed on the support stand of a vertical load manual test stand HV-500N II (manufactured by IMADA Co., Ltd.), and the repulsive force detected when the indenter was pressed 5 mm was measured. Measurements were performed on one test piece in two ways: with the longitudinal direction of the film positioned parallel to the indenter, and with the width direction positioned parallel to the indenter. The average of the two measured values ​​obtained was taken as the bending resistance (gf) of the film. Tip radius of indenter: 2mm Corner radius of support base: 2mm Distance between supports: 40mm D. Thermal resistance of porous media Thermal conductivity was measured in accordance with JIS A 1412-2 (1999) 6.2, and the thermal resistance was calculated by multiplying the obtained thermal conductivity by the thickness. Specifically, a 30cm square sample cut from the porous body was placed in a thermal conductivity measuring device HC-074 (manufactured by Eiko Seiki Co., Ltd.), and measurements were performed under conditions of a plate temperature difference of 25°C and an average temperature of 20°C (high temperature plate temperature 32.5°C, low temperature plate temperature 7.5°C). The thermal conductivity (W / m·K) was calculated from the average value of three tests. The thermal resistance (m 2 ·K / W).

[0028] [Example 1] A biaxially stretched polyethylene terephthalate film (Toray Industries, Inc., "Lumirror #100-S10," 100 μm thick) was preheated to 200°C and then pressed between an embossing roll (engraved with a striped pattern) heated to 110°C and a nip roll to obtain an embossed film with an arithmetic mean roughness Sa of 231 μm. The basis weight and bending resistance of this embossed film are shown in Table 1. Next, two 50 cm square pieces of this embossed film were prepared as the first and second films. A 50 cm square polyethylene terephthalate fabric, which had been prepared separately as a skin material for an automotive headliner, and a 50 cm square urethane foam, which had been prepared as an insulating material, were bonded with an adhesive in the following order: polyethylene terephthalate fabric / first film / urethane foam / second film, to produce a laminate simulating an automotive headliner. For this bonding, 3M's styrene butadiene rubber spray adhesive "Spray Glue 99" was used, and the amount applied to each interface was 3g / m 2 The obtained laminate was held at the four corners and hung in an oven at 80°C for 200 hours, after which the presence or absence of sagging in the center was visually confirmed. The details of the structure of the automobile ceiling material of this example and the evaluation results are shown in Table 1.

[0029] [Comparative Example 1] In Example 1, except that a pre-embossed biaxially stretched film made of polyethylene terephthalate ("Lumirror #100-S10" manufactured by Toray Industries, Inc., thickness 100 μm) was used instead of the embossed film, the arithmetic mean roughness, basis weight, and bending resistance of the film were measured in the same manner as in Example 1. A laminate with urethane foam and polyethylene terephthalate fabric was also produced and the amount of sagging at the center after maintaining it at 80°C for 200 hours was measured. The details of the configuration of the automobile ceiling material of this comparative example and the evaluation results are shown in Table 2.

[0030] Comparative Example 2 In Example 1, instead of the two embossed films (the first film and the second film), a 150 g / m 2The glass fiber sheet was used in the same manner as in Example 1, except that the glass fiber sheet was used. The basis weight and bending resistance of the glass fiber sheet were measured, and a laminate was prepared with urethane foam and polyethylene terephthalate fabric, and the amount of sagging at the center after maintaining it at 80°C for 200 hours was measured. Table 2 shows the details of the configuration of the automobile ceiling material of this comparative example and the evaluation results.

[0031] Comparative Example 3 In Example 1, the embossing roll was changed to obtain an embossed film with an arithmetic mean roughness Sa of 67 μm. The arithmetic mean roughness, basis weight, and bending resistance of the embossed film were measured in the same manner as in Example 1, and a laminate with urethane foam and polyethylene terephthalate fabric was produced and the amount of sagging at the center after maintaining it at 80° C. for 200 hours was measured. Table 2 shows the details of the configuration of the automobile ceiling material of this comparative example and the evaluation results.

[0032] [Example 2] In Example 1, except that the embossing roll was changed to obtain an embossed film with an arithmetic mean roughness Sa of 112 μm, the basis weight and bending resistance of the embossed film were measured in the same manner as in Example 1. A laminate with urethane foam and polyethylene terephthalate fabric was also prepared and the amount of sagging at the center after maintaining it at 80° C. for 200 hours was measured. The details of the configuration of the automotive ceiling material of this example and the evaluation results are shown in Table 1.

[0033] [Example 3] In Example 1, except that a nonwoven fabric made of polyethylene terephthalate was used instead of the urethane foam prepared as a heat insulating material, a laminate made entirely of polyethylene terephthalate was prepared by laminating a polyethylene terephthalate woven fabric and a polyethylene terephthalate nonwoven fabric in the same manner as in Example 1, and the amount of sagging at the center after maintaining it at 80°C for 200 hours was measured. The details of the configuration of the automobile ceiling material of this example and the evaluation results are shown in Table 1.

[0034] [Table 1]

[0035] [Table 2] [Industrial Applicability]

[0036] The automobile ceiling material of the present invention is easily recyclable and can be used as an automobile ceiling material in various types of mobility such as automobiles, trains, buses, and ships.

Claims

1. An automobile ceiling material comprising a laminate formed by laminating a fiber material / a first film / a porous body / a second film in this order, wherein the fiber material, the first film, the porous body and the second film are all made of a thermoplastic resin, and the first film and the second film each have an embossed pattern with an arithmetic mean roughness Sa of 100 μm or more.

2. 2. The automobile ceiling material according to claim 1, wherein the first film and the second film are both polyester films.

3. 3. The automobile ceiling material according to claim 2, wherein the fibrous material and the porous body are both made of polyester.

Images