JPH0647856A - 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 generate an offensive odor at high temperature, generates little quantity of harmful gas in burning, is light in weight, and easy to be recycled. CONSTITUTION:A facing material is made of polypropylene resin, and an interior material for an automobile is made of a polypropylene resin internal die foamed material and a shape-holding material.

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.

[0006] In recent years, in the automobile industry, in order to improve the fuel efficiency of automobiles, there is a strict demand for weight reduction of parts (parts) constituting the automobile, and as a part thereof, further weight reduction is achieved. From the viewpoint of resource recycling, development of easily recyclable interior materials for automobiles has been awaited.

[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 intensive research to develop an automobile interior material that can satisfy many requirements at the same time, such as easy recycling, a completely new automobile interior material that can satisfy all of these requirements at the same time. Finally, he came to complete the present invention.

[0008]

That is, the present invention relates to an automobile interior material composed of a polypropylene resin skin material, a polypropylene resin extruded foam sheet, and a shape-retaining material.

[0009]

OPERATION AND EXAMPLES When the interior material for automobiles of the present invention is pressed, the polypropylene resin in-mold foam formed on the back surface of the skin material made of polypropylene resin forming the skin is made of the conventional resin. By imparting a soft tactile sensation to the core material, the interior material for automobiles has a profound feeling and a high-class feeling. In particular, when the skin material is a polypropylene resin extruded foam sheet, a very soft and supple touch is obtained.

Further, since the interior material for automobiles of the present invention is provided with the polypropylene resin in-mold foam, which is a layer capable of absorbing impact, as described above, it is also excellent in cushioning property. In particular, when a polypropylene resin extruded foam sheet is provided, a better cushioning property is imparted.

Further, in the conventional automobile interior material 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. It has an excellent property that the amount of gas that is harmful to the human body is small and the amount of gas that is harmful to the human body is small.

As described above, the automobile interior material of the present invention is composed of a polypropylene resin skin material, a polypropylene resin in-mold foam and a shape-retaining material.

The polypropylene resin means 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 include polystyrene, polybutene, and ionomers, and the blending amount of these thermoplastic resins is usually 100 parts by weight of the polypropylene resin (weight part, the same applies hereinafter).
It is preferably 20 parts or less, especially about 5 to 10 parts.

Examples of the skin material made of the polypropylene resin include a polypropylene resin sheet and a laminated sheet of the polypropylene resin sheet and the polypropylene resin extruded foam sheet.

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-based resin extruded foam sheet is an extruded foam sheet formed by extrusion-foaming a polypropylene-based resin, and is capable of imparting a soft touch to the obtained automobile interior material. 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. Tend to be too soft, so 10
It is preferably about 30 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,
The obtained automobile interior materials tend to feel too soft, so 1 to 4 mm, especially 1.5 to 3.
It is preferably about 5 mm.

In the laminated sheet, the polypropylene-based resin sheet and the polypropylene-based resin extruded foamed sheet are integrated by, for example, a method of heat-melting integration,
It can be carried out by a method of integrating the both with an adhesive, and the present invention is not limited by such a method of integration.

The polypropylene-based 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 a 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 ratio of the polypropylene resin pre-expanded particles and the polypropylene resin in-mold foam is too large, the resulting automobile interior material will be too soft to the touch and will be too soft. If it is too small, the feel of the obtained automobile interior material tends to be too hard, so 5-30
It is desirable that the number is twice, preferably 7 to 27 times, and more preferably 10 to 25 times.

If the thickness of the polypropylene-based resin in-mold foam is too small, the mechanical properties such as compressive strength and flexural strength of the obtained automobile interior material become inferior, and too much. If too large,
Since there is a tendency for problems to occur in the design of automobile interior materials, it is usually 3 to 50 mm, preferably 5 to 30 mm, more preferably 5 to 20 mm.

The surface material made of the polypropylene resin and the polypropylene resin in-mold foam can be integrated by, for example, heating the contact surfaces of the skin material and the in-mold foam, respectively, and then stacking and melting them. It can be carried out by a method of wearing and integrating, or a method of integrating the above-mentioned skin material with an in-mold foam with an adhesive agent. In the present invention, a skin material is further prepared in advance and this is used in the mold. After being mounted in the foaming mold, the polypropylene resin pre-expanded particles are filled into the in-mold foaming mold, and at the same time as molding of the in-mold foaming mold, the skin material and the in-mold foaming mold are formed. A method of integrating them can be adopted.

When an adhesive is used to integrate the skin material and the molded in-mold foam, as the adhesive, for example, chlorinated polypropylene dissolved in an organic solvent such as toluene. Etc., and this may be applied to the surface of the skin or the adhesive surface of the in-mold foam in an appropriate amount.

In addition, after mounting the skin material in the in-mold foam molding die, when molding the in-mold foam molding and simultaneously integrating the skin material and the in-mold foam molding, the adhesive is used. For example, a suitable amount of chlorinated polypropylene may be previously attached to the adhesive surface of the skin material.

The shape-retaining material is mainly capable of imparting a deformation preventing function, a reinforcing function, an assembly material attaching function, etc. to an automobile interior material.

The shape of the shape-retaining material may be adjusted according to the shape of the interior material for automobiles and the like. Examples of the material of the shape-retaining material include metal, wire mesh, wood, thermoplastic resin such as polyethylene, polypropylene, ABS resin, thermosetting resin such as phenol resin and formaldehyde resin, FRP, and the like. Is not limited to only these examples.

As will be described later, when the shape-retaining material is integrated with the in-mold foam during molding of the in-mold foam, the shape-retaining material is softened and melted by heating during molding. Then, since the function of preventing deformation of the shape-retaining material is not sufficiently exhibited, it is preferable to use a material that can withstand heating during molding as the shape-retaining material.

Considering the recyclability of the obtained automobile interior material, the material of the automobile interior material is
For example, polypropylene is particularly preferable.

Generally, in the interior materials for automobiles, the in-mold foam material shrinks immediately after being taken out from the in-mold foam molding die.
On the surface where the skin material is provided, the shrinkage of the in-mold foam is suppressed by the skin material, whereas on the surface where the skin material is not provided, the shrinkage proceeds, and as a result, the interior material for automobile is It will be transformed.

In order to prevent such deformation of the automobile interior material, that is, to impart a deformation preventing function, a shape-retaining material is attached to the surface of the automobile interior material on which the skin material is not provided, Alternatively, the shape retention material is embedded in the in-mold foam.

The shape retaining material is attached to the surface of the automobile interior material on which the skin material is not provided. For example, as shown in the schematic sectional view of the automobile interior material of FIG. The shape-retaining material 3 is attached to the surface on which the skin material 2 is not provided. Thus, when the shape-retaining material 3 is attached to the surface of the interior material for automobiles where the skin material 2 is not provided, for example, in an in-mold foam molding die, the inner surface of the die on the side where steam is not introduced is After providing the skin material 2 and the shape-retaining material 3 on the inner surface of the die on the side where steam is introduced, the in-mold foam molding die is closed and pre-expanded particles are filled in the in-mold foam molding die. Then, a method of molding can be adopted. In this case, in order to firmly bond the in-mold foam 1 and the shape-retaining material 3 to each other, the surface of the shape-retaining material 3 in contact with the in-mold foam 1 should be preliminarily coated with an adhesive. Is preferred.

Examples of such an adhesive include resin dissolved in an organic solvent, resin emulsion and resin powder. Examples of the resin include ethylene-vinyl acetate resin, polypropylene, chlorinated polypropylene, polyethylene, ethylene-propylene copolymer, chlorinated polypropylene, chlorinated polyethylene, ethylene-propylene-butene terpolymer, and polyolefin resins such as a mixture thereof. I can give you
The present invention is not limited to only these examples. The amount of the adhesive used is not particularly limited and may be appropriately adjusted according to the type of adhesive, the desired adhesive strength, and the like.

In the case of imparting only the above-mentioned deformation preventing function to an automobile interior material, in order to reduce the weight, as a material of the shape-retaining material, a material such as polypropylene which is itself lightweight is used. It is preferable to use.

When a shape-retaining material having a high hardness is used, not only the deformation preventing function but also the strength of the automobile interior material itself, that is, the reinforcing function can be enhanced.

In the automobile interior material shown in FIG. 1, a plate-shaped material is used as the shape-retaining material. For example, an attachment tool for connecting to another member is the shape-retaining material. 1 may be provided.

As the in-mold foam of an automobile interior material in which a shape-retaining material is embedded, for example, as shown in the schematic sectional view of the automobile interior material of FIG. An example is one in which the shape-retaining material 3 is embedded.
Note that, in FIG. 2, reference numeral 4 denotes a mounting portion provided so as to be able to be connected to another member, for example, but the present invention is not limited to the shape of the mounting portion 4. . Further, in the present invention, if the mounting portion 4 is not necessary, it may not be provided.

As a method of embedding the shape-retaining material 3 in the in-mold foam 1 of an automobile interior material, for example, in the in-mold foam molding die, the skin material 2 is provided on the inner surface of the die on the side where steam is not introduced, Further, it is possible to adopt a method in which after the shape-retaining material 3 is provided on the inner surface of the mold on the side where the steam is introduced, the mold is closed, pre-expanded particles are filled in the in-mold foaming mold, and then the mold is molded. However, in this case, in order to embed the molding holding material 3 in the in-mold foam body 1, for example, a groove is provided in a part of the mold, and the mounting portion 4 of the shape holding material 3 is inserted into the groove. It is preferable that the shape-retaining material 3 is embedded in the in-mold foam body 1 without being embedded in the mounting portion 4 during molding.

In order to improve the adhesiveness with the in-mold foam body 1, it is preferable that the same adhesive agent as described above is previously attached to the surface of the shape-retaining material 3.

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 A polypropylene resin sheet (thickness 0.75 mm) was attached to a mold surface having no steam holes.

Further, a die having a steam hole (vertical 300 mm,
An iron shape retention material (vertical 280 mm, horizontal) with an iron hook (surface coating: ethylene-vinyl acetate resin) for fixing a set screw as a mounting part in a groove provided on the inner surface of the horizontal 500 mm, depth 200 mm The hook (480 mm, depth 180 mm) was inserted and fixed.

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 resistant container in advance and the internal pressure was 2 kg / cm.
^{Using the one in which 2} · G was given by air, 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.) was introduced into the in-mold foaming mold from a mold having steam holes, and preheated, and a preliminary operation was performed for about 10 seconds. After steaming the foamed particles, the internal pressure in the mold
The drain and water vapor were sucked and removed using a vacuum pump so that the pressure was 500 mmHg or less.

Then, 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 20 seconds, and then cooled. ,
The in-mold foaming mold was opened to obtain an automobile interior material having a cross-sectional shape as shown in FIG.

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.

(A) Tactile feeling As conventional automobile interior materials, 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). ~ 3 mm) obtained by laminating in order (hereinafter, conventional product A
Prepared).

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, evaluation was made based on the following evaluation criteria.

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

B: The obtained automobile interior material is softer than the conventional product A, but does not have a two-level soft touch.

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

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

E: Conventional product A has a better tactile sensation than the obtained automobile interior material.

(B) Buffering property A steel ball weighing 100 g was dropped from a position of 50 cm in height on the 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 was dropped and rebound was higher in the conventional product A.

B: The height of the steel ball when the steel ball is dropped and repelled is almost the same in both the conventional product A and the obtained instrument panel.

C: The height of the steel ball when the steel ball is dropped and rebounded is higher in the instrument panel.

(C) The interior material for automobiles and the test piece (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 a 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 due to the obtained automobile interior material.

B: When the door of the constant temperature and constant humidity chamber is opened, an odor is felt due to the obtained interior material for automobiles.
Weaker than.

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.

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: By disassembling the obtained automobile interior material for each constituent material, any of them can be used for recycling.

C: The obtained automobile interior material contains materials that cannot be used for recycling.

(E) Generation of harmful gas It was examined whether or not the constituent materials of the obtained automobile interior material include a material which is generally 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 material, which is said to generally generate a harmful gas during combustion, is partially contained.

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

Example 2 A polypropylene resin sheet (thickness: 0.5 mm) was used in place of the resin sheet used in Example 1, and the resin sheet was attached to the inner surface side of a mold having no steam holes to obtain polypropylene. Shape retention material (vertical 280 mm, width 480 mm, depth 180 m)
m) was used to fix the shape-retaining material to the other mold having steam holes, and an automobile interior material having a cross-sectional shape as shown in FIG. 1 was obtained in the same manner as in Example 1.

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) were used, and the resin sheet surface of the laminated sheet was attached to the inner surface side of a mold having no steam holes.

Further, a die having a steam hole (vertical 300 mm,
A shape-retaining material similar to that used in Example 1 was inserted and fixed in a groove on the inner surface having a width of 500 mm and a depth of 200 mm.

Eperan PP (manufactured by Kanegafuchi Chemical Industry Co., Ltd., trade name, foaming ratio 30 times) was filled as a pre-expanded polypropylene resin particle 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-foamed particles for 10 seconds, then 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 500 mmHg or less.

After that, steam (steam 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, and after holding for 20 seconds, it was 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 (trade name, manufactured by Kanegafuchi Chemical Industry Co., Ltd.,
Except that a foaming ratio of 15) was used,
From the filling of the pre-expanded particles to the suction removal of the drain and water vapor.

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, and the interior material for automobiles was opened. 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 extruded foam sheet (foaming ratio 20 times, thickness 3 mm), foamed polyurethane layer (thickness 10 mm). ) And an 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.

[0086]

[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 than the conventional product B, so they were used to construct automobiles. It was able to fully meet the demand for weight reduction of existing parts.

[0089]

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.

FIG. 2 is a schematic cross-sectional view of an example of an automobile interior material of the present invention.

[Explanation of symbols]

 1 Polypropylene resin in-mold foam 2 Skin material 3 Shape retention material

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[Procedure amendment]

[Submission date] April 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

After mounting the skin material in the in-mold foam molding die , an adhesive is used when molding the in-mold foam molding and at the same time integrating the skin material and the in-mold foam molding. /> the case, with such adhesives, for example using a chlorinated polypropylene, which it is sufficient deposited at pre proper amount to the bonding surface of the skin material.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0063

[Correction method] Change

[Correction content]

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

Claims (8)

[Claims] 1. A skin material made of polypropylene resin,
An interior material for automobiles, which comprises a polypropylene-based resin in-mold foam and a shape-retaining material. 2. The interior material for automobiles according to claim 1, wherein the skin material made of polypropylene resin is a polypropylene resin sheet. 3. The automobile interior material according to claim 1, wherein the skin material made of polypropylene resin is a laminated sheet of a polypropylene resin sheet and a polypropylene resin extruded foam sheet. 4. The interior material for automobiles according to claim 3, wherein the polypropylene resin extruded foam sheet has a foaming ratio of 10 to 30 times. 5. The interior material for automobiles according to claim 1, 2, 3 or 4, wherein the expansion ratio of the polypropylene resin in-mold foam is 5 to 30 times. 6. The interior material for automobile according to claim 1, wherein the shape-retaining material is adhered to the surface of the polypropylene-based resin in-mold foam. 7. The automobile interior material according to claim 1, wherein the shape-retaining material is embedded in a polypropylene-based resin in-mold foam. 8. The automobile interior material according to claim 6, wherein the shape-retaining material has a mounting portion.