JPH0647854A - Interior material for automobile - Google Patents

Abstract

PURPOSE:To provide an interior material for an automobile which gives a soft flexible tactual sense in pressing, is excellent in shock-absorbing property, has a depth impression, does not an offensive odor at high temperature, generates little quantity of harmful gas in burning, is light in weight, and easy to be recycled. CONSTITUTION:An interior material for an automobile is prepared as follows; a polypropylene resin sheet, a polypropylene resin extrusion foamed sheet, and a polypropylene resin internal die foamed material are successively laminated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an automobile interior material. More specifically, for example, automotive door materials, sun visors, ceiling materials, door trims, rear packages, knee bolsters, airbag doors, headrests, armrests, various pillars, quarter trims, front side trims, front seat backs, crash pads, consoles. Automotive interior materials such as boxes, console lids, luggage floor covers, partition boards, center consoles, and console box lids.

[0002]

2. Description of the Related Art Conventionally, as an interior material for automobiles, a leather sheet such as polyvinyl chloride, a foam sheet such as polypropylene foam, and a core material such as ABS resin are sequentially polymerized, and are integrally formed by using an adhesive. There is known one in which a bound laminate is heated and softened and pressure-molded by a mold (Japanese Patent Laid-Open No. 54-158471).

However, although the interior material for automobiles has a foam sheet, it has the drawbacks that it has a hard tactile sensation when pressed, is poor in cushioning property, and has no profound feeling.

As a material capable of eliminating the drawbacks of the interior materials for automobiles, a leather sheet made of polyvinyl chloride, a foam sheet such as polypropylene foam, a polyurethane foam layer and a core material such as ABS resin are sequentially laminated, Integrated laminates are known.

Since the laminate has a foamed polyurethane layer in its intermediate layer, a soft tactile sensation is surely imparted when pressed, and the cushioning property is improved as compared with the automobile interior material. However, its weight is larger than that of the interior material for automobiles, and there is a drawback that a bad odor based on polyvinyl chloride is emitted at a high temperature and a harmful gas is generated at the time of combustion.

Further, in recent years, in the automobile industry, in order to improve the fuel efficiency of automobiles, it has been strictly demanded to reduce the weight of parts constituting the automobile, and as a part thereof, further reduction in weight has been achieved. The development of automobile interior materials and automobile interior materials that are easy to recycle from the viewpoint of reusing resources is highly desired.

[0007]

Therefore, the present inventors have found that
In view of the above-mentioned prior art, a soft and supple touch is imparted when pressed, excellent cushioning, there is a profound feeling, does not generate a bad odor at high temperature, produces a small amount of harmful gas at the time of combustion, and is lightweight. As a result of earnest research to develop an automobile interior material that can satisfy many requirements such as high efficiency and easy recycling, it is finally possible to obtain a completely new automobile interior material that can satisfy all of these requirements at the same time. Heading, it came to complete the present invention.

[0008]

That is, the present invention relates to an automobile interior material in which a polypropylene resin sheet, a polypropylene resin extruded foam sheet, and a polypropylene resin in-mold foam are sequentially laminated.

[0009]

OPERATION AND EXAMPLE The interior material for automobiles of the present invention, which does not require a core material made of ABS resin or the like, which has been required in the prior art, has a significantly improved weight saving. It was done. The present invention eliminates the need for such a core material in view of the characteristics of the interior material for automobiles, in view of the mechanical properties required for the interior material for automobiles, particularly the compressive strength and the bending strength. It is based on the fact that the polypropylene resin in-mold foam has a sufficient amount.

Further, in the automobile interior material of the present invention, when pressed, the polypropylene resin extruded foam sheet formed on the back surface of the polypropylene resin sheet forming the skin first imparts a soft touch, and The polypropylene-based resin in-mold foam formed on the back surface of the polypropylene-based resin extruded foam sheet is slightly harder than the extruded foamed sheet, but imparts a very soft touch to the core material made of conventional resin. By providing a so-called two-step soft touch feeling, and by giving a soft and supple touch feeling to the fingers and the like that come into contact with the automobile interior material of the present invention, the automobile interior material has a profound feeling and a high-grade feeling. Is brought about.

Further, as described above, the automobile interior material of the present invention is provided with the two shock-absorbing layers of the polypropylene-based resin extruded foam sheet and the polypropylene-based resin in-mold foam. It is also excellent in sex.

Further, in the conventional interior materials for automobiles of the present invention, since the leather sheet mainly made of polyvinyl chloride is used for the outer skin, the temperature inside the automobile reaches a high temperature such as in summer. Although a nasty odor was sometimes emitted, the problem of odor at a high temperature was solved because a substrate that generates such a bad odor was not used.

Furthermore, the automobile interior material of the present invention comprises:
Since all the base materials that make up this are made of polypropylene resin, it is easy to recycle it, and moreover, it is said that when the foamed polyurethane burns, it emits harmful gas that is harmful to the human body. Is less, and the amount of gas that is harmful to the human body is small.

As described above, the interior material for automobiles of the present invention comprises a polypropylene resin sheet, a polypropylene resin extruded foam sheet, and a polypropylene resin in-mold foam laminated in this order.

The polypropylene resin is a propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-butene random terpolymer, propylene-vinyl chloride copolymer, propylene-butene copolymer, propylene-maleic anhydride. It refers to a resin having a propylene content of 50% by weight or more, such as an acid copolymer, and these resins are used alone or in combination of two or more kinds. The polypropylene-based resin is preferably in a non-crosslinked state, but may be crosslinked with peroxide or radiation.

As the polypropylene resin,
You may use what mixed the other thermoplastic resin which can be mixed with this polypropylene resin. Specific examples of such other thermoplastic resins include, for example, low density polyethylene,
Examples thereof include polystyrene, polybutene, and ionomers, and the amount of these thermoplastic resins compounded is usually 20 parts with respect to 100 parts of the polypropylene resin (parts by weight, the same applies hereinafter).
It is preferable that the amount is not more than 5 parts, especially about 5 to 10 parts.

The thickness of the polypropylene-based resin sheet is not particularly limited, but if it is too small, the profound feeling becomes poor, and if it is too large, the flexibility becomes poor. Therefore, it is usually 0.3 to 2 mm, preferably 0.5 to 1.5 mm.

The polypropylene resin extruded foam sheet is an extruded foam sheet obtained by molding a polypropylene resin by an extrusion foaming method. If the expansion ratio of such an extruded foam sheet is too small, the obtained automobile interior material tends to be too hard to touch, and if it is too large, the obtained automobile interior material has a touch feeling. Since it tends to be too soft, it is preferably about 10 to 30 times, especially about 15 to 25 times.

When the thickness of the extruded foamed sheet is too small, the obtained automobile interior material tends to have a hard tactile sensation and tends to have a low cushioning property. If it's too big,
Since the obtained automobile interior material tends to be too soft to the touch, it is preferably about 1 to 4 mm, more preferably about 1.5 to 3.5 mm.

The polypropylene-based resin sheet and the polypropylene-based resin extruded foamed sheet can be integrated by, for example, a method of heat-melting integration or a method of integrating both with an adhesive. The method of integration is not limited.

In the present invention, the polypropylene-based resin sheet and the polypropylene-based resin extruded foamed sheet which are previously integrated are prepared,
This may be integrated with the polypropylene-based resin in-mold foam.

The polypropylene resin in-mold foam is
It is obtained by in-mold foam molding of polypropylene resin pre-expanded particles.

When the polypropylene resin pre-expanded particles are filled into the in-mold expansion molding die through the feeder, the pre-expanded particles are preliminarily pressurized with a pressurized gas, and the pressurized gas is contained in the pre-expanded particles. May be filled into the in-mold foaming mold while being sufficiently penetrated into the mold, and the pre-expanded particles may be compressed into the in-mold foaming mold by being compressed with a pressurized gas. Alternatively, the pre-expanded particles may be filled in the in-mold foaming mold without applying internal pressure or compression, and the present invention is not limited by the filling method. Absent.

If the expansion ratios of the polypropylene resin pre-expanded particles and the polypropylene resin in-mold foam are too large, the obtained interior material for automobiles will be too soft to the touch, and too much. If it is too small, the feel of the obtained automobile interior material tends to be too hard, so it is usually 5
~ 30 times, preferably 7 to 27 times, more preferably 10 to 25 times
It is desirable to be doubled.

If the thickness of the polypropylene-based resin in-mold foam is too small, the resulting automobile interior material will have inferior mechanical properties such as compressive strength and bending strength, and will be too small. If too large,
Since it tends to cause problems in the design of the obtained automobile interior materials, it is usually 3 to 50 mm, preferably 5 to 50 mm.
It is desirable that the distance is 30 mm, more preferably 5 to 20 mm.

The polypropylene-based resin extruded foam sheet and the polypropylene-based resin in-mold foam may be integrated by, for example, heating and melting the contact surfaces of the extruded foam sheet and the in-mold foam, respectively, and then stacking and melting them. It can be carried out by a method of attaching and integrating, a method of integrating the extruded foam sheet with an in-mold foam with an adhesive, etc., but in the present invention, a polypropylene resin sheet and a polypropylene resin extruded foam sheet are further added. A laminate is prepared in advance, and this is mounted in an in-mold foam molding die, and then filled with polypropylene resin pre-expanded particles, and at the same time as molding of the in-mold foam molded article, the laminate is placed in the mold. For example, a method of integrating with the foamed molded product can be adopted.

Thus, the automobile interior material of the present invention can be obtained. In the present invention, a laminate of the polypropylene resin sheet and the polypropylene resin extruded foam sheet is formed into a desired shape by, for example, a vacuum forming method. After that, this is mounted in a mold for in-mold foam molding, and then pre-expanded particles are filled and in-mold foam-molded to be integrated to obtain an automobile interior material having a desired shape. The above-mentioned laminate softened by heating may be superposed on and integrated with the in-mold foam molded article to obtain an automobile interior material having a desired shape.

Next, FIG. 1 is a schematic cross-sectional view of the automobile interior material of the present invention.

In FIG. 1, 1 is a polypropylene resin sheet, 2 is a polypropylene resin extruded foam sheet, 3
Is a polypropylene resin in-mold foam. A polypropylene resin extruded foam sheet 2 is formed on the lower surface of the polypropylene resin sheet 1, and a polypropylene resin in-mold foam body 3 is formed on the lower surface of the extruded foam sheet 2. Since the polypropylene-based resin in-mold foam body 3 does not directly appear as an outer skin to the outside, a meat steal 5 may be formed in the inside for the purpose of reducing the weight, and for connecting with other members. An insert material 4 such as a fixture may be provided. The insert material 4 such as the fixture can be integrated with the in-mold foam when manufacturing the in-mold foam.

Next, the automobile interior material of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1 Polypropylene resin sheet (thickness 0.75 mm) and polypropylene resin extruded foam sheet (foaming ratio 20 times, thickness 3 m)
m) and the laminated product were integrated so that the surface of the resin sheet was in contact with the mold surface having no steam holes.

Further, a die having a steam hole (vertical 300 mm,
An iron hook (surface coating: ethylene-vinyl acetate resin) for fixing the set screw was fixed as an insert material to a part of the inner surface of the width 500 mm, depth 200 mm).

As pre-expanded polypropylene resin particles, Eperan PP (manufactured by Kanegafuchi Chemical Industry Co., Ltd., trade name, expansion ratio 15 times) was placed in a pressure vessel in advance and the internal pressure was 2 kg / cm.
² · G was given by air, and it was filled in the in-mold foaming mold made of the above-mentioned mold.

Next, steam (steam pressure 0.6 kg / cm ² · G, temperature 112 to 115 ° C.) is introduced into the in-mold foaming mold from a mold having steam holes and preheated for about 10 seconds. After steaming the expanded particles, the internal pressure in the in-mold foam molding die was reduced to 50%.
The drain and water vapor were sucked and removed using a vacuum pump so that the pressure became 0 mmHg or less.

After that, steam (steam pressure 3.5 kg / cm ² · G, temperature 146 to 148 ° C.) was introduced into the in-mold foaming mold from a mold having steam holes, kept for 25 seconds, and then cooled. Then, the in-mold foaming mold was opened to obtain an automobile interior material.

As the physical properties of the obtained automobile interior material, the feel, cushioning property, odor at high temperature, recyclability, and generation of harmful gas during combustion were examined according to the following methods. The results are shown in Table 1.

(B) Tactile feeling As conventional interior materials for automobiles, polyvinyl chloride sheet (thickness 0.5 mm), polypropylene resin extruded foam sheet (foaming ratio 20 times, thickness 3 mm) and ABS resin plate (thickness 2). (Hereinafter, referred to as conventional product A) was prepared by sequentially stacking up to 3 mm.

Next, the tactile sensation of the obtained automobile interior material was examined by pressing it with a finger, and compared with the conventional product A, it was evaluated based on the following evaluation criteria.

(Evaluation Criteria) A: The obtained automobile interior material is clearly the conventional product A.
It has a softer and more supple texture than that.

B: The obtained automobile interior material is slightly softer and more supple than the conventional product A.

C: There is almost no difference in the feeling of touch between the obtained automobile interior material and the conventional product A.

D: The conventional product A has a better tactile sensation than the obtained automobile interior material.

(B) Cushioning property A steel ball weighing 100 g was dropped from a height of 50 cm onto the flat surface portion of the obtained automobile interior material and the conventional product A on the skin side, based on the following evaluation criteria. And evaluated.

(Evaluation Criteria) A: The height of the steel ball when the steel ball is dropped and rebounded is higher in the conventional product A.

B: The height of the steel ball when the steel ball is dropped and rebounded is almost the same in both the conventional product A and the obtained automobile interior material.

C: The height of the steel ball when the steel ball is dropped and rebounded is higher in the automobile interior material.

(C) The interior materials for automobiles and the test pieces (20 × 20 cm) of the conventional product A, which had an odor at high temperature, were separately heated at a temperature of 60 ° C. and relative humidity of 50
After being left for 24 hours in a constant temperature and humidity chamber, the evaluation was performed based on the following evaluation criteria.

(Evaluation Criteria) A: When the door of the constant temperature and constant humidity chamber is opened, no odor is felt by the obtained automobile interior material.

B: When the door of the constant temperature and constant humidity chamber is opened, the odor due to the obtained interior material for automobile is felt, but the conventional product A
Weaker than.

C: When the door of the constant temperature and constant humidity chamber is opened, the odor caused by the obtained automobile interior material is almost the same as that of the conventional product.

D: When the door of the constant temperature and constant humidity chamber is opened, the odor caused by the obtained automobile interior material is stronger than that of the conventional product A.

(D) Recyclability The recyclability of the obtained automobile interior material was evaluated based on the following evaluation criteria.

(Evaluation Criteria) A: The obtained automobile interior material can be used as it is for recycling without disassembling it for each constituent material.

B: If the obtained automobile interior material is decomposed into its constituent materials, any of them can be used for recycling.

C: The obtained automobile interior materials include materials that cannot be recycled.

(E) Generation of harmful gas It is examined whether or not the constituent material of the obtained automobile interior material generally contains a material which is said to generate a harmful gas at the time of combustion, and evaluated based on the following evaluation criteria. Was done.

(Evaluation Criteria) A: Materials that are generally said to generate harmful gas during combustion are not included.

B: A part of materials which are generally said to generate harmful gas during combustion are included.

C: All materials are generally said to generate harmful gas upon combustion.

Example 2 Instead of the laminate used in Example 1, a laminate of a polypropylene resin sheet (thickness 0.5 mm) and a polypropylene resin extruded foam sheet (expansion ratio 20 times, thickness 2.5 mm) An automobile interior material was obtained in the same manner as in Example 1 except that a sheet was used and the resin sheet surface of the laminated sheet was attached so as to be in contact with the die surface having no steam holes, and no insert material was used.

The physical properties of the obtained automobile interior material are shown in Example 1.
I examined it in the same way. The results are shown in Table 1.

Example 3 A polypropylene resin sheet (having a thickness of 0.75) was used as a skin material.
mm) and a polypropylene-based resin extruded foam sheet (foaming ratio: 20 times, thickness: 3.5 mm), and affixed so that the resin sheet surface of the laminated sheet is in contact with the mold surface having no steam holes. .

Further, a die having a steam hole (vertical 300 mm,
A polyolefin resin hook (surface coating: chlorinated polypropylene) for fixing the set screw was fixed as an insert material to a part of the inner surface of the horizontal 800 mm, depth 20 mm).

As pre-expanded polypropylene resin particles, Eperan PP (manufactured by Kanegafuchi Chemical Industry Co., Ltd., trade name, foaming ratio 30 times) was filled into the in-mold foaming mold through a feeder.

Next, steam (vapor pressure of 0.
5 kg / cm ² · G, temperature 109-113 ℃) was introduced into the in-mold foaming mold to preheat, depressurize and steam the pre-expanded particles for 10 seconds, and then the in-mold foaming mold The internal pressure inside
The drain and water vapor were removed by suction using a vacuum pump so that the pressure was 260 mmHg or less.

After that, steam (vapor pressure: 3.2 kg / cm ² · G, temperature: 144 to 146 ° C.) was introduced into the in-mold foaming mold through the steam holes of the mold, held for 20 seconds, and then cooled. Then, the in-mold foaming mold was opened to obtain an automobile interior material.

The physical properties of the obtained automobile interior material are shown in Example 1.
I examined it in the same way. The results are shown in Table 1.

Example 4 In Example 3, as the polypropylene resin pre-expanded particles, Eperan PP (manufactured by Kanegafuchi Chemical Industry Co., Ltd., trade name,
The process from filling the pre-expanded particles to suction removal of the drain and water vapor was performed in the same manner as in Example 3 except that the expansion ratio was 15 times) and the insert material was not used.

Next, steam (vapor pressure 3.
5 kg / cm ² · G, temperature 146 to 148 ℃) was introduced into the in-mold foam molding die, held for 20 seconds, then cooled, and then the in-mold foam molding die was opened to give the interior material for automobiles. I got it.

The physical properties of the obtained automobile interior material are shown in Example 1.
I examined it in the same way. The results are shown in Table 1.

Comparative Example 1 As a conventional automobile interior material, a leather sheet made of polyvinyl chloride (thickness 0.5 mm), a polypropylene resin extruded foam sheet (foaming ratio 20 times, thickness 3 mm), foamed polyurethane layer (thickness) 10 mm) and ABS resin plate (thickness 2 mm)
Were sequentially laminated and integrated to obtain a laminate (hereinafter referred to as conventional product B).

The physical properties of the obtained conventional product B were examined in the same manner as in Example 1. The results are shown in Table 1.

[0073]

[Table 1]

From the results shown in Table 1, the automobile interior materials of the present invention obtained in Examples 1 to 4 could not have all of the conventional products A and B, and had an excellent tactile sensation. It can be seen that, at the same time, it has excellent buffering properties, odorless at high temperature, excellent recyclability, and no generation of harmful gas during combustion.

The interior materials for automobiles of the present invention obtained in Examples 1 to 4 all had a profound feeling, but were lighter in weight than the conventional product B, and thus constituted automobiles. It was able to fully meet the demand for weight reduction of existing parts.

[0076]

Industrial Applicability The automobile interior material of the present invention provides a soft and supple feel when pressed, has excellent cushioning property, has a profound feeling, does not generate a bad odor at high temperature, and emits noxious gas when burning. It produces a number of excellent effects, such as a small amount of waste generated, weight reduction, and easy recycling.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an example of an automobile interior material of the present invention.

[Explanation of symbols]

 1 Polypropylene resin sheet 2 Polypropylene resin extruded foam sheet 3 Polypropylene resin in-mold foam

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[Procedure amendment]

[Submission date] April 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

C: When the door of the constant temperature and constant humidity chamber is opened, the odor caused by the obtained interior material for automobile is almost the same as that of the conventional product A.

Claims (4)

[Claims] 1. An interior material for an automobile, comprising a polypropylene resin sheet, a polypropylene resin extruded foam sheet, and a polypropylene resin in-mold foam laminated in this order. 2. The automobile interior material according to claim 1, further comprising an insert material. 3. The interior material for automobiles according to claim 1 or 2, wherein the polypropylene resin in-mold foam has a foaming ratio of 5 to 30 times. 4. The interior material for an automobile according to claim 1, 2 or 3, wherein the polypropylene resin extruded foam sheet has a foaming ratio of 10 to 30 times.