JP3003445B2 - Automotive interior materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automotive interior materials such as automotive ceiling materials, door trims and pillar trims.

[0002]

2. Description of the Related Art Conventionally, as a core material of an interior material for an automobile, a wood board and a felt using a thermosetting binder such as a phenol resin as a recycled fiber or A thermoplastic resin or the like containing an inorganic fiber such as a glass fiber has been used by hot pressing or cold pressing. Therefore, most of the final appearance of the interior material is such that the above-mentioned wooden board or felt is used as a core material and a skin layer composed of a pad and a skin material is laminated and adhered to the surface thereof.

FIG. 2 shows an example of a conventional headlining. In FIG. 2, the conventional headlining includes a felt 6 for preventing contact noise, a urethane foam 4 and a felt 5 impregnated with a thermosetting resin between the roof panel 1 and the skin 2.

[0004]

However, such conventional interior materials have the following disadvantages. First, in addition to having a multi-layer structure, since the material is different for each layer, it is necessary to separate and collect each layer in order to reuse the used material, and it is practically difficult to reuse. In particular, it is difficult to incinerate a resin or the like containing a glass fiber in a core material, and there is a concern about environmental friendliness.

Second, the core material is generally inexpensive, and at the same time, it is necessary to have a high rigidity to maintain its shape. Met. For this reason, there is a disadvantage that the sound in the room is reflected and the noise cannot be reduced.

Third, since the core material generally has a high elastic modulus, the surface hardness is high. For this purpose, the panels of the body (often steel), often installed in the vehicle
Interfered with each other, causing the problem of abnormal noise. As a measure against this,
In most cases, a soft nonwoven fabric or urethane foam is interposed between the interference surface between the interior core material and the panel. But,
This countermeasure has a problem that the number of steps for sandwiching the nonwoven fabric is enormous and uneconomical. Therefore, the object of the present invention is to
An object of the present invention is to provide an interior material that can be manufactured at lower cost and has improved sound absorption and reusability.

[0007]

In the present invention, the above object is achieved by changing the material used as the core material of the interior material for automobiles from a conventional wooden board and felt to a thermoplastic nonwoven fabric. Softening point 80 ℃ ~ 22 as this non-woven fabric
By using the thermoplastic fiber at 0 ° C., heat molding can be performed again, and an interior material having high recyclability can be provided. Since the core material occupying the main component of the interior material is the above-mentioned thermoplastic fiber, it is natural that energy recycling or the like by combustion or the like is easy. As the fibers used, thermoplastic polymers such as polyamide, copolymerized polyamide, polyester, copolymerized polyester, polyacrylonitrile, copolymerized polyacrylonitrile, polyolefin, polyvinyl chloride, polyvinylidene chloride, and polychloral are used alone, mixed or composited. Fibers obtained by spinning are mentioned, and the core material needs to contain 90% by weight or more of these fibers. Among the fiber types,
Considering the high crystal melting point (Tm) and the relatively low cost, polyester fibers are optimal, but are not particularly limited.

The smaller the diameter of the fiber is, the more preferable it is.
In the present invention, it is 30 denier or less. From the viewpoint of fiber composition, it is convenient to mix fibers having different softening points in order to firmly bond the fibers to each other. Therefore,
By molding near the softening point of the low softening point fiber, the fibers are firmly bonded to each other, and a nonwoven fabric having excellent strength can be obtained. The difference in the melting points of the fibers may be at least 20 ° C, but is preferably at least 50 ° C.

Next, the sound absorbing effect of the interior material will be described. The interior material of the automobile belongs to the position closest to the occupant's ear, and if this portion has a sound absorbing effect, it can contribute to the quietness of the vehicle efficiently. However, since conventional felts are often used by being crushed thinly, the surface density increases and the sound is reflected, so that almost no sound absorbing effect can be expected. A non-porous material such as a wood board cannot essentially expect a sound absorbing effect. In the present invention, since the nonwoven fabric layer is a thicker layer than before, the sound absorbing effect is excellent. The thickness must be 5 to 40 mm, especially 10
It is preferably not less than mm and not more than 30 mm. If the thickness is less than 5 mm, no sound absorbing effect can be expected. On the other hand, if the thickness is more than 40 mm, it is not realistic when viewed from the space of the vehicle. In terms of weight, it is necessary that the area density of the nonwoven fabric is 0.5 to 3.0 kg / m ² . At 0.5 kg / m ² or less, the sound absorbing effect is low and not suitable. When the surface density is 3.0 kg / m ² or more, not only is the part too heavy but also the density is too high, so that sound reflection on the surface increases and the sound absorbing effect decreases, which is not preferable. When limited to the head lining automotive, nonwoven surface density is preferably 0.8 to 1.8 Kg / m ^2, thickness 5
20 mm is suitable, but not particularly limited.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows a headlining according to the present invention. In FIG. 1, this headlining comprises a thermoplastic fiber core material 3 according to the invention between a roof panel 1 and a skin 2. In the present invention, since the abutting sound preventing felt 6 and the urethane foam 4 are not required, the head lining can be formed in a simple structure, recycling can be facilitated, the number of working steps can be reduced, and the cost can be reduced. Can be done.

[0011]

Next, the operation will be described. The performance requirement for the core material of the interior material is firstly rigidity. In order to obtain sufficient rigidity, in the prior art, the bending rigidity was improved by crushing the felt core material as thinly as possible and increasing the elastic modulus. It is well known that bending stiffness is proportional to the cube of the elastic modulus and thickness of a material. this is,
When the thickness is doubled, the bending rigidity is increased eight times. That is, when the same bending stiffness is required, the elastic modulus required for the material when the thickness is doubled is only 1/8. Since the interior material of the present invention has a sufficient thickness, sufficient rigidity can be ensured even at a low elastic modulus. Therefore, the nonwoven fabric used in the present invention has a low modulus of elasticity, so that the feel when pressed is soft, and the skin urethane foam layer conventionally used to improve the feel is unnecessary, thereby reducing the cost. Can be. On the other hand, in the case of felt, the interior material cannot be made according to the present invention.
This is because, in the felt, the recycled fiber and the thermosetting resin are simply mixed, and the wetness is not good, so that the fiber and the resin do not sufficiently adhere to each other unless crushed thinly. Because there is.

Further, by lowering the elastic modulus, there is obtained an advantage that rubbing noise can be suppressed. Since the conventional core material has a high elastic modulus, an abutment sound is generated at the interference surface with the panel during the running of the vehicle. For this reason, in the prior art, a flexible felt or the like is interposed on the interference surface when actually used. Since the core material used in the present invention has a low elastic modulus, it does not generate a contact sound with the panel, and therefore, no inclusion such as felt is required. This is a huge advantage in terms of reusability and cost. Further, in order to impart rigidity, a resin plate, a film, rigid paper, or the like can be attached to the back side (skin side and the opposite side) of the core material and the inside of the core material layer.

[0013]

The present invention will be described below with reference to examples, comparative examples and test examples. In addition, unless otherwise indicated, all% in an example shows weight%. Examples 1 to 4 70% of polyester fiber having a fiber diameter of 2 denier (hereinafter referred to as polyester 2d fiber) (softening point 220 ° C.) and 30% of copolymerized polyester 3d fiber (softening point 110 ° C.) 30% Then, a core material (polyester non-woven fabric) having the thickness and the surface density shown in Table 1 was prepared, pre-heated at 180 to 200 ° C., and a skin material in which a polyethylene hot melt adhesive was adhered to the back surface was used. It was stacked and formed into a desired shape and thickness by a cooling mold (vehicle headlining mold), or trimmed into a desired shape to obtain an automobile headlining. The headlining thus obtained was fixed to the ceiling of the vehicle by pressing both armpits, and attached to the vehicle by screwing together with a room lamp and a sun visor.

Example 5 Polyester 2d fiber in Example 1 (softening point 220
° C) and copolymerized polyester 3d fiber (softening point 110 ° C) were changed to 60% to 40%, and the thickness and areal density were changed as shown in Table 1.
The procedure was the same as that of Example 1 except that the procedure was as shown in FIG.

Examples 6 to 9 The procedure of Example 1 was repeated except that the fibers used for the core material were as shown in Table 1, and the area density of the core material was 1.2 kg / m ² .

Example 10 The procedure of Example 9 was repeated except that the thickness of the core material was changed to 15 mm.

Example 11 The procedure of Example 1 was repeated, except that the surface density of the core material was changed to 3.0 kg / m ² .

Example 12 In Example 11, the thickness of the core was 40 mm and the area density was 1.8 k.
The same operation as in Example 11 was performed except that g / m ² was used.

Example 13 In Example 5, the thickness of the core material was 22 mm and the area density was 0.6 k.
The procedure was the same as in Example 5, except that g / m ² was used.

Example 14 The procedure of Example 6 was repeated, except that the diameter of the polyester fiber used for the core was changed to 13d.

Example 15 Example 14 was carried out in the same manner as in Example 14, except that the diameter of the polyester fiber used for the core was changed to 26d.

Example 16 In Example 15, the copolymer polyester 3d used for the core material was used.
Example 15 was repeated except that the softening point of the fiber was set to 200 ° C.

Comparative Example 1 A core material (felt) having a thickness of 2.5 mm and an areal density of 1.4 kg / m ² was prepared by blending 70% of recycled fiber and 30% of a phenol resin. A skin material with a hot melt adhesive bonded to the back is laminated and molded into a desired shape and thickness by a mold (vehicle headlining mold) preheated to 180 to 200 ° C, or trimmed to a desired shape. Thus, an automotive headlining was obtained.

The headlining thus obtained was mounted on a vehicle in the same manner as in Example 1.

Comparative Example 2 Comparative Example 1 was carried out in the same manner as in Comparative Example 1 except that the area density of the core was 1.2 kg / m ² and the roof insulator was not used.

Comparative Example 3 The procedure of Example 5 was repeated, except that the thickness of the core material was changed to 4 mm.

Test Examples The following tests were performed on the automotive headlinings obtained in Examples 1 to 16 and Comparative Examples 1 to 3. Squeaking sound: The created headlining was mounted on a vehicle, and the vehicle was run on a rough road at 30 km / h to evaluate the presence or absence of squeaking noise. ◎ ---- No squeaks at all. 〇 ---- I can hear a slight squeak, but I don't notice much. × ---- A squeaky sound is always heard, which is bothersome.

Maximum load: A method for evaluating the rigidity of a sample. A uniform thickness portion was cut out from the prepared headlining to obtain a 50 mm × 120 mm sample. This sample was placed on two supports at a distance of 100 mm, and the test piece was bent by compressing the central part between the two supports with the pressing body of a pressure wedge moving at a compression speed of 50 mm / min. Then, the maximum bending load was determined. Usually, a value of about 2.5kgf is required for interior materials for automobiles.

Recyclability: Evaluated according to the following criteria. ◎ ---- From the skin to the core material, it is composed of the same type of thermoplastic resin at 80% by weight or more. 〇 ---- 80% by weight or more of thermoplastic resin from skin to core. × ---- The thermosetting resin is contained in the core material from the skin. Remaining room method sound absorption coefficient; Place the prepared sample in the remaining room, JISA
The sound absorption coefficient was measured by the method specified in 1409. In the table, 1kH
Only the sound absorption coefficient at z is shown. Constant speed noise: The sample was mounted on a vehicle, the vehicle ran at a speed of 100 km / h, and the actual noise was measured at the driver's seat occupant's ear. Table 1 shows the results of each test. In addition, "2d fiber" in Table 1
Means fibers having a fiber diameter of about 15-17 μm.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

[0034]

As described above, in the present invention, the use of a thermoplastic non-woven fabric as the core material of an automobile interior material improves sound absorption, reduces cost, and further improves reusability. The advantage is that it can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a headlining according to the present invention.

FIG. 2 is a sectional view of a conventional headlining.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roof panel 2 Skin 3 Thermoplastic fiber core material by this invention 4 Urethane foam 5 Thermosetting resin impregnated felt 6 Felt for preventing contact noise

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Claims (3)

(57) [Claims] 1. An automobile interior material comprising a nonwoven fabric layer serving as a core material, a skin layer facing the interior of a vehicle cabin, and an adhesive layer interposed between the two layers, wherein a diameter of a fiber constituting the nonwoven fabric layer is 30. 90% by weight or more of the fiber has a softening point of 80 to 220 ° C., and the fiber comprises a fiber having a softening point different by 20 ° C. or more,
Their weight ratio is 10:90 to 90:10, and the areal density of the nonwoven fabric layer is 0.5 to 3.0 kg / m ² and the thickness is 5 to 40 mm.
An interior material for automobiles, wherein the skin layer is mainly composed of polyester fibers. 2. The interior material for an automobile according to claim 1, wherein said nonwoven fabric is made of polyester fiber. 3. The interior material for a vehicle according to claim 1, wherein the laminate is a head lining for a vehicle.