JP3172281B2 - Manufacturing method of 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 a method for producing an automobile interior material. More specifically, it has a luxurious feeling unique to the fibrous skin and a soft touch, such as car door materials, instrument panels, sun visors, ceiling materials,
Door trim, rear package, knee bolster, airbag door, headrest, armrest, various pillars,
Quarter trim, front side trim, front seat back, crash pad, console box,
The present invention relates to a method for manufacturing an interior material for an automobile that can be suitably used as a console lid, a luggage floor cover, a partition board, a center console, a console box lid, and the like.

[0002]

2. Description of the Related Art Conventionally, automotive interior materials have been manufactured by a method in which an in-mold foam is prepared in advance, an adhesive is applied to the foam, and a skin material is then attached. However, according to such a method, a manufacturing process is complicated because it requires three steps of a step of producing an in-mold foam, a step of applying an adhesive, and a step of attaching a skin material to the in-mold foam. However, there is a disadvantage that the production efficiency is not good.

[0003] As a method that can solve the disadvantages of the above method,
A pair of molds having a plurality of steam holes are provided with a porous sheet having air permeability on at least the steam hole surfaces, filled with thermoplastic resin foam particles, and then steam is introduced from the steam holes to form the porous sheet and foam. A method is known in which particles are fused by heating and integrated (Japanese Patent Application Laid-Open No. HEI 3-190723).

The above method is effective when the skin material is a porous sheet. However, when the skin material is a sheet having no air permeability, the steam introduced from the steam holes is not effective. Because the sheet is hindered by the sheet and does not reach the foamed particles, the foamed particles are not sufficiently heated, causing poor fusion. There is a problem that it is inferior to that fused with an adhesive.

[0005] In recent years, interior materials for automobiles having a conventional fibrous skin have a high-grade feel and soft touch peculiar to the fibrous skin. There is a long-awaited need for development of interior materials for automobiles that give a supple feel when done.

[0006]

The inventors of the present invention have conducted intensive studies in view of the above-mentioned prior art, and as a result, have found that a laminate of a fibrous skin and an extruded polypropylene resin foam sheet can be foamed in a polypropylene resin mold. It has been found that the laminate laminated on the body has a high-grade feel and soft touch peculiar to the fibrous skin, gives a supple feel when pressed, and can be suitably used as an interior material for automobiles. ing.

However, although the fibrous skin of the laminate has air permeability, the extruded polypropylene resin foam sheet does not have air permeability, so that the fibrous skin and the polypropylene resin extruded in the mold as described above. When the method of integrating the foamed sheet laminate with the molding of the foam in the polypropylene resin mold at the same time is adopted, there is a problem that a fusion defect occurs in the foamed mold in the mold. A complicated means of forming each of the foamed molded articles in advance and bonding and integrating them by using, for example, an adhesive or the like had to be adopted.

The present invention has been made in view of the above situation, and uses a breathable fibrous skin, which is formed by laminating an extruded polypropylene resin foam sheet having no breathability on the fibrous skin. In this case, the in-mold foam can be produced from the pre-expanded particles and the fibrous skin and the laminate of the extruded foam sheet can be integrated at the same time. It is an object of the present invention to provide a method for manufacturing an interior material for an automobile having no poor wearing.

[0009]

That is, the present invention provides a laminate of a breathable fibrous skin and an extruded polypropylene resin foam sheet so that the fibrous skin is in contact with the inner surface of the mold A. After the holding material is provided on the inner surface of the mold B, the mold A and the mold B are clamped to form a molding die.
Filling the molding die with the polypropylene resin pre-expanded particles, supplying steam from the vapor holes of the mold B, and pre-heating the pre-expanded particles at a temperature lower than the temperature at which the pre-expanded particles fuse together. After that , the pre-expanded particles are steamed with steam, and then the pre-expanded particles are fully heated from a mold B at a temperature not lower than a temperature at which the pre-expanded particles are fused to each other. And a laminate of an air-permeable fibrous skin and an extruded polypropylene resin foam sheet is provided so that the fibrous skin contacts the inner surface of the mold A, and the mold A and the mold B are molded. After tightening to form a molding die, the polypropylene resin pre-expanded particles are filled into the molding die, and steam is supplied from a vapor hole of the die B,
After preheating the pre-expanded particles at a temperature lower than the temperature at which the pre-expanded particles fuse to each other, the pre-expanded particles are steamed with steam, and then at a temperature higher than the temperature at which the pre-expanded particles are fused to each other. The pre-expanded particles are fully heated from the mold B at the temperature, and the mold is opened to form a product of the in- mold foam obtained.
The present invention relates to a method of manufacturing an interior material for an automobile, wherein a shape maintaining material is provided on a surface on which a layer body is not provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for manufacturing an automotive interior material according to the present invention requires that the pre-expanded particles be heated from both sides in a molding die with steam or the like in order to eliminate defective fusion between the pre-expanded particles. It is a completely new method of manufacturing interior materials for automobiles that breaks down the conventional wisdom that had never been considered.

[0011] Further, although the reason why the method for producing an interior material for automobiles of the present invention can produce an in-mold foam molded article having no defective fusion between particles is not clear, it has not been clarified yet. In addition to heating by steam, a step of performing pre-heating under specific conditions and then steaming is adopted, so that the pre-expanded particles on the side of the mold into which steam is introduced and the pre-expanded particles on the laminate side It can be inferred that the difference in temperature between the foamed particles is reduced and the fusion property by the main heating is improved.

An embodiment of the method for producing an interior material for a vehicle according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory view showing one embodiment of a mold used in the production method of the present invention.

In FIG. 1, a mold A1 is clamped to a mold B2. In FIG. 1, a mold A1 having no steam hole is used. However, in the present invention, a steam hole may be provided since there is no particular problem. The mold A1 is, for example, a cylinder 3
The mold A1 and the mold B2 can be clamped and opened by moving the mold A1. A plurality of steam holes 4 are provided on the inner surface of the mold B2, and the steam introduced from the steam inlet 5 passes through the steam holes 4 through the interior 6 of the mold B2 to the molding chamber 7. be introduced. Further, a feeder 8 is provided in the mold B2, and the polypropylene resin pre-expanded particles as a raw material are introduced into the molding chamber 7 by the feeder 8.

On the inner surface of the mold A, a laminate 11 of a fibrous skin 10 having air permeability and an extruded polypropylene resin sheet 9 is provided.

Examples of the air-permeable fibrous skin 10 include woven fabric, non-woven fabric and knitted fabric.
The present invention is not limited to only such examples. In the present invention, the type of the fibrous skin 10 may be appropriately selected and used depending on the type of the target interior material for automobiles and the like. As an example, for example, when an interior material for automobiles having a soft brushed feel is to be obtained, a needle-punched nonwoven fabric may be used as the fibrous skin 10, and an automobile having a so-called backskin-like luxury When the interior material is used, a suede-like artificial leather such as Exeine (trade name) manufactured by Toray Industries, Inc. can be used as the fibrous skin 10.

The type of fiber used for the fibrous skin 10 is not particularly limited, and examples thereof include polyester fiber, polyethylene fiber, polypropylene fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyamide fiber, and ethylene-vinyl acetate copolymer. Synthetic fibers such as coalesced fibers; semi-synthetic fibers such as rayon fibers and acetate fibers; and natural fibers such as cotton and wool. Among these fibers, polyester fibers are preferable in terms of heat resistance, light resistance, abrasion resistance, and the like. Polypropylene fibers and polyethylene fibers, particularly polypropylene fibers, have an adhesive property with the extruded polypropylene resin foam sheet 9. It is preferable from the viewpoint of recyclability.

The thickness of the fibrous skin 10 is
What is necessary is just to adjust suitably according to ten kinds, the target surface state of the obtained interior material for automobiles, etc.

The extruded polypropylene resin sheet 9 is a sheet formed by extrusion foaming of a polypropylene resin, and has no air permeability. The extruded foam sheet 9 is used as an intermediate layer between the fibrous skin 10 and the in-mold foam, and imparts a supple feel to the obtained automobile interior material when pressed. When the expansion ratio of the extruded foam sheet 9 is too small, the feel of the obtained interior material for automobile tends to be too hard, and when it is too large, the obtained interior material for automobile tends to be too hard. Since the feel tends to be too soft, it is preferably about 10 to 30 times, especially about 15 to 25 times.

If the thickness of the extruded foam sheet 9 is too small, the resulting interior material for automobiles tends to have a hard feel or a small cushioning property. If it is too large, the resulting interior material for automobiles tends to be too soft, so that it is preferably about 1-4 mm, especially about 1.5-3.5 mm.

The fibrous skin 10 and the extruded foam sheet 9 are integrated by, for example, a method of integrating the two with an adhesive. The fibrous skin 10 is made of a thermoplastic resin fiber, especially a polyolefin resin fiber. In some cases, the two can be performed by a method of heat-melting and integrating the two, and the present invention is not limited by such an integrating method.

In the present invention, the fibrous epidermis is used.
A laminate in which the extruded foam sheet 9 and the extruded foam sheet 9 are integrated in advance is prepared, and this can be integrated with the in-mold foam.

The laminated body 11 of the fibrous skin 10 and the extruded foam sheet 9 is formed in advance into a desired shape by, for example, vacuum forming or the like so as to be adapted to the inner surface shape of the mold A1. Alternatively, the laminate 11
When is flexible, it is mounted in a mold, and molded into a desired shape by, for example, a vacuum molding method, and then pre-expanded particles are filled into the mold and molded. Is also good.

In order to improve the adhesiveness between the extruded foam sheet 9 and the pre-expanded particles, an adhesive may be provided in advance on the surface of the extruded foam sheet 9 which comes into contact with the pre-expanded particles. Examples of such an adhesive include a resin dissolved in an organic solvent, a resin emulsion, a resin powder and the like. Examples of the resin include ethylene-vinyl acetate resin, polypropylene, polyethylene, ethylene-propylene copolymer, chlorinated polypropylene, chlorinated polyethylene, ethylene-propylene-
Examples thereof include polyolefin-based resins such as butter polymers and mixtures thereof, but the present invention is not limited to these examples. The amount of the adhesive used is
There is no particular limitation, and it may be appropriately adjusted according to the type of the adhesive, the desired adhesive strength, and the like.

In the present invention, the foam in the mold shrinks immediately after being taken out of the molding die.
On the surface where is provided, shrinkage of the in-mold foam is suppressed by the polypropylene resin extruded foam sheet 9, whereas on the surface where the laminate 11 is not provided, shrinkage proceeds,
As a result, the automotive interior material is deformed.

In order to prevent such deformation of the interior material for automobiles, that is, to impart a deformation preventing function, a surface of the interior material for automobiles where the laminate 11 is not provided, that is, the in-mold foam , The shape-retaining material is provided by attaching the shape-retaining material to the surface on the side where the laminate is not provided , or by embedding the shape-retaining material in an in-mold foam.

The interior material for automobiles used in the present invention can have a reinforcing function, an assembly material attaching function, and the like in addition to the deformation preventing function.

As a method of providing the shape-retaining material, for example, a shape-retaining material is provided on the inner surface of the mold B in advance, and the shape-retaining material and the in-mold foam are integrated during the in-mold foaming of the pre-expanded particles. After laminating the laminate of the fibrous skin and the extruded polypropylene resin foam sheet and the in-mold foam in a molding die and taking out the molded product from the molding die, a shape-retaining material is provided on the surface of the in-mold foam. Method.

The shape of the shape-retaining material may be adjusted according to the shape of the interior material for an automobile or the like. Examples of the material for the shape-retaining material include paper, metal, wire mesh, wood, thermoplastic resins such as polyethylene, polypropylene, and ABS resins, phenol resins, thermosetting resins such as formaldehyde resins, and FRP. The present invention is not limited to only such examples. Among such materials, for example, polypropylene is particularly preferable in consideration of the recyclability of the obtained interior material for automobiles.

In the former method, when the shape holding material is integrated with the in-mold foam during molding of the in-mold foam, the shape holding material is softened and melted by heating during molding. Since the function of preventing deformation of the material is not sufficiently exhibited, it is preferable to use a material that can withstand heating during molding as the shape maintaining material.

Also, in the interior material for automobiles , foaming in the mold is required.
Body, when sticking the shape-retaining material on the surface on the side where the laminate 11 is not provided, then provided with a shape-retaining material to the inner surface of the mold B, closing the mold, the mold the pre-expanded particles In this case, in order to firmly adhere the in-mold foam and the shape-retaining material during the in-mold foam molding of the pre-expanded particles, the pre-expanded particles of the shape-retaining material are used. For example, the adhesive or the like may be attached in advance to the surface in contact with.

In the case where only the deformation preventing function is given to the interior material for automobile, in order to reduce the weight, the material of the shape retaining material is made of a material which is itself lightweight such as paper. Preferably, it is used.

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

When embedding the shape retaining material in the in-mold foam of the interior material for automobiles, for example, as shown in FIG.
After providing the shape retaining material 12 on the inner surface of the mold B2, the molding die is closed, the pre-expanded particles are filled in the molding die, and then molded. In order to be embedded in the body, for example, a groove is provided in a part of the mold B2, and an attachment portion 13 for connecting to, for example, another member is inserted into the groove. May be embedded. In addition, the mounting portion 13
There is no particular limitation on the shape, and if such a mounting portion 13 is not required, it may not be provided.

In order to improve the adhesiveness with the pre-expanded particles, the adhesive may be applied to the surface of the shape-retaining material 12 as described above, for example.

The latter method of providing the shape retaining material, that is , a laminate of an in-mold foam obtained by opening a mold.
When the method of providing the shape holding material on the surface on which the is not provided is adopted, the shape holding material and the in-mold foam surface may be bonded using, for example, the adhesive.

In the two methods of providing the shape retaining material on the surface of the foam in the mold, shrinkage of the foam in the mold generally starts immediately after the mold is opened, and such shrinkage is sufficiently prevented. In the present invention, the former method is particularly preferable.

After the mold A1 and the mold B2 are clamped, the pre-expanded polypropylene resin particles are filled into the mold via the feeder 8.

Examples of the polypropylene resin used in the polypropylene resin pre-expanded particles include propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-butene random terpolymer, and propylene-vinyl chloride copolymer. , Propylene-
Resins having a propylene content of 50% by weight or more, such as butene copolymers and propylene-maleic anhydride copolymers, may be used, and these may be used alone or in combination of two or more.

The polypropylene resin is preferably in a non-crosslinked state, but may be crosslinked by peroxide or radiation.

Further, as the polypropylene resin,
A mixture of other thermoplastic resins that can be mixed with the polypropylene resin may be used. Specific examples of such other thermoplastic resins include, for example, low-density polyethylene,
Examples thereof include linear low-density polyethylene, polystyrene, polybutene, and ionomer. These thermoplastic resins are usually used in an amount of 20 parts or less, especially 5 parts by weight, based on 100 parts of the polypropylene resin (parts by weight, hereinafter the same).
Preferably, the amount is up to 10 parts.

The polypropylene resin is usually melted in advance using, for example, an extruder, a kneader, a Banbury mixer, a roll, or the like so as to be easily prefoamed. In the desired particle shape, the average particle size of the particles is 0.1 to 10 m
m, preferably 0.7 to 5 mm.

As a method for producing the pre-expanded polypropylene resin particles, for example, a volatile foaming agent is added to the polypropylene resin particles in a pressure vessel, dispersed in water with stirring, and then heated under a predetermined foaming temperature. After the heating, the water dispersion is discharged into a low pressure region. However, the present invention is not limited to such a method.

If the expansion ratio of the polypropylene resin pre-expanded particles is too large, the resulting in-mold expanded molded article tends to shrink or become too soft, and is also too small. In such a case, the buffering property tends to be reduced.
Times, preferably 5 to 50 times, more preferably 8 to 45 times,
It is particularly desirable that the ratio be 10 to 35 times.

In filling the polypropylene resin pre-expanded particles into a molding die through the feeder 8,
The pre-expanded particles may be pressurized in advance by using a pressurized gas, and the pressurized gas may be sufficiently permeated into the pre-expanded particles, and filled in a mold under an internal pressure. The particles may be filled in a molding die in a compressed state using a pressurized gas, or the pre-expanded particles may be filled in the molding die as they are without applying an internal pressure or compressing. The present invention is not limited by such a filling method.

After filling the polypropylene-based resin pre-expanded particles into a mold, steam is supplied from the steam holes 4 of the mold B2, and the pre-expanded particles are fused at a temperature lower than the temperature at which the pre-expanded particles fuse together. Preheat the expanded particles.

The present invention is also characterized in that the pre-expanded particles are pre-heated at a temperature lower than the temperature at which the pre-expanded particles fuse with each other. Thus, the pre-expanded particles are pre-heated. In this case, the pre-expanded particles are sufficiently heated without fusion before performing the main heating, and can be uniformly and uniformly fused by the main heating. In the present invention, during the preheating, if the pre-expanded particles are heated to a temperature equal to or higher than the fusion temperature, the pre-expanded particles are preferentially fused from the steam hole side, and as a result, Since the water vapor hardly penetrates to the pre-expanded particles on the skin material side and poor fusion occurs, preheating is performed at a temperature lower than the fusion temperature of the pre-expanded particles. Since the fusion temperature of such pre-expanded particles cannot be unconditionally determined because it differs depending on the type of resin used for the pre-expanded particles, the fusion temperature of the pre-expanded particles is checked in advance, Mold B
It is preferable to set the temperature of the steam introduced from the second steam hole 4.

The above-mentioned fusion temperature means that when a pre-expanded particle is filled in a mold having a depth of about 50 mm and steam at a predetermined temperature (predetermined pressure) is introduced into the mold for 10 to 20 seconds, The minimum temperature at which the pre-expanded particles fuse with each other to maintain the shape of the in-mold foam molded article.

If the temperature of the steam at the time of preheating is too low, the effect of the preheating tends to be insufficient, so that the temperature of the steam is not higher than the fusion temperature of the pre-expanded particles. At least 35 ° C lower than the fusing temperature, preferably 3 ° C lower than the fusing temperature to 30 ° C lower than the fusing temperature, more preferably 5 ° C lower than the fusing temperature to lower than the fusing temperature. Desirably, the temperature is 25 ° C. or lower than the deposition temperature.

The pressure of the steam during the preheating may be appropriately adjusted so that the temperature of the steam is within the above range.

Next, another feature of the present invention is that steam is supplied from the steam hole 4 of the mold B2 and preheated, and then the pre-expanded particles are steamed with steam. When steaming the pre-expanded particles with steam, the steaming may be performed in a state where preheating is performed, or may be performed in a state where the supply of steam is stopped and a drain valve is opened. When the pre-expanded particles are steamed in this way, the latent heat of the steam introduced between the pre-expanded particles in the molding die can be effectively utilized, and a particularly thick in-mold foam is produced. If
There is an advantage that the pre-expanded particles can be heated uniformly. When the pre-expanded particles are steamed in this manner, the time required for the steaming depends on the thickness of the pre-expanded particle layer in the mold, the size and shape of the pre-expanded particles, the shape and the expansion ratio, etc. Since the transmission speed is different, it cannot be unconditionally determined, but usually the thickness of the pre-expanded particle layer is, for example, about 50 mm and is about 3 seconds or more, preferably about 5 seconds or more, and more preferably 10 seconds or more. It is desirable.

After performing the steaming, a drain (water) exists between the pre-expanded particles, and if the main heating is performed in this state, poor fusion of the pre-expanded particles may occur. It is preferable to remove the generated drain. As a method of removing such a drain, for example, the molding chamber 7 is formed by using the steam hole 4 provided in the mold B2.
The inside of the mold A is evacuated by passing high-temperature dry air through the steam holes 4 so that the pre-expanded particles do not fuse.
There is a method in which a gap is provided between the mold 1 and the mold B2, and the drain is removed from the gap. However, the present invention is not limited to such a method.

Next, the pre-expanded particles are fully heated at a temperature equal to or higher than the temperature at which the pre-expanded particles are fused to each other.

The main heating is performed by the steam inlet 5 of the mold B2.
By heating the pre-expanded particles through the steam through the steam hole 4 through the steam hole 4 and simultaneously introducing steam through the steam inlet 14 of the mold A1 to steam heat the mold A1. In addition, as a method of heating the mold A1, a method of heating using a heater or the like, for example, can be adopted in addition to a method of heating with steam.

The pressure of the steam may be adjusted so that the temperature of the steam falls within a temperature range described later.

The temperature of the water vapor may be higher than the temperature at which the pre-expanded particles fuse with each other. If the temperature of the water vapor is too high, the shrinkage of the obtained in-mold foam molded article may be reduced. Since it tends to be too large, it is desirable that the temperature be 30 ° C. or lower than the temperature at which the pre-expanded particles are fused, and preferably 25 ° C. or lower than the temperature at which the pre-expanded particles are fused.

After the pre-expanded particles are fully heated, it is preferable that the pre-expanded particles be kept in this state in order to sufficiently transfer the heat of the steam to the pre-expanded particles. The time required for such holding can not be determined unequivocally because it depends on the thickness of the pre-expanded particle layer and the like, but as an example, for example, when the thickness of the pre-expanded particle layer is about 100 mm, about It is desirable that the time be 3 seconds or more, preferably about 5 seconds or more, but if the time is too long, the obtained in-mold foam molded article shrinks, so that no shrinkage occurs during molding. It is preferable to set appropriately within the range.

Next, by opening the mold, an interior material for an automobile is obtained.

In the present invention, the obtained automobile interior material may be cooled before opening the mold.

The obtained interior material for automobiles contracts immediately after being separated from the molding die.
It is preferable to cure under normal pressure of ~ 80 ° C for about 3 to 24 hours.

According to the method for manufacturing an interior material for an automobile of the present invention, although the extruded foam sheet does not have air permeability, the in-mold foam is produced from the pre-expanded particles, and at the same time, the skin material and the in-mold foam are combined. It is possible to manufacture an automotive interior material that can be integrated and that does not cause the occurrence of defective fusion of pre-expanded particles to the in-mold foam.

The production method of the present invention can also be applied to a case where the in-mold foam having a large thickness and the laminate are integrally formed.
A good automotive interior material can be provided without causing poor fusion of the pre-expanded particles on the surface in contact with the laminate of the in-mold foam, so that the in-mold foam has a relatively large wall thickness, for example, It is possible to suitably manufacture an interior material for automobiles comprising the in-mold foam having an extremely large thickness of about 100 mm and the laminate.

Next, the method for producing the interior material for automobiles of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples.

Example 1 A needle-punched non-woven fabric (thickness: 2 mm) made of polypropylene fiber and a polypropylene resin extruded foam sheet (expansion ratio: 20 times, thickness: 3 mm) were heated and melted at their bonding surfaces, and then laminated. The laminated and integrated laminate was attached so that the nonwoven fabric surface was in contact with the flat mold surface having no vapor holes.

A mold having a steam hole (300 mm long,
An iron frame (diameter: 1 mm, surface coating: 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 width 800 mm, depth 20 mm) Rectangular shape holding material (250 mm long, horizontal) made of ethylene-vinyl acetate resin
750 mm).

Eperan PP (produced by Kane-buchi Chemical Industry Co., Ltd., trade name, expansion ratio: 15 times) was previously placed as a polypropylene resin pre-expanded particle in a pressure vessel, and the internal pressure was 2 kg / cm.
^A mold provided with ² · G by air was used to fill a mold comprising the above-described mold.

Next, steam (steam pressure: 0.6 kg / cm ² · G, temperature: 112 to 115 ° C.) is introduced into the mold from a mold having a steam hole, and preheated, and the pre-expanded particles are formed for about 10 seconds. After steaming, the drain and water vapor were removed by suction using a vacuum pump so that the internal pressure in the mold became 500 mmHg or less.

After that, steam (steam pressure: 3.5 kg / cm ² · G, temperature: 146 to 148 ° C.) was introduced from a mold having a steam hole into the mold, held for 25 seconds, cooled, and cooled. Was opened to obtain interior materials for automobiles.

As the physical properties of the obtained interior material for automobiles, the fusion rate, the adhesion to the laminate, the feel, the cushioning property and the recyclability were examined according to the following methods. Table 1 shows the results.
Shown in

(A) Fusing rate A thin cut was made on the surface of the in-mold foam molded article of the obtained interior material for automobiles with a knife, then bent and fractured, and the fracture surface was observed. The area ratio was expressed as a percentage and evaluated based on the following evaluation criteria.

(Evaluation Criteria) A: The fusion rate is 60% or more B: The fusion rate is 40 to 59% C: The fusion rate is 20 to 39% D: The fusion rate is 19% or less The obtained laminate and the in-mold foam molded product were peeled off, the state of the interface was observed, and the evaluation was performed based on the following evaluation criteria.

(Evaluation Criteria) A: Only material breakage is observed in the foam layer. B: Both material breakage of the foam layer and interfacial peeling between the foam layer and the laminate are observed. C: Interfacial peeling between the laminate and the foam layer is observed. D: The laminate and the foam layer are not bonded.

(C) Feeling As conventional interior materials for automobiles, needle-punched non-woven fabric (thickness: 2 mm) made of polypropylene fiber, flexible polyurethane foam sheet (expansion ratio: 8 times, thickness: 8 mm) and AB
An S resin plate (thickness: 2 to 3 mm) was sequentially laminated, and a product (hereinafter, referred to as a conventional product A) was prepared.

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

(Evaluation Criteria) A: The obtained automotive interior material clearly has a softer and more supple feel than the conventional product A. B: The obtained automotive interior material has a slightly softer and more supple feel than the conventional product A. C: There is almost no difference in the tactile sensation 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.

(D) Buffering property A steel ball having a weight of 100 g is dropped from a position of 50 cm height onto the surface portion of the obtained interior material for automobile and the conventional product A on the skin side, based on the following evaluation criteria. Was evaluated.

(Evaluation Criteria) A: The height of the steel ball when the steel ball is dropped and rebounds is higher in the conventional product A. B: The height of the steel ball when the steel ball is dropped and rebounds is substantially the same for both the conventional product A and the obtained automotive interior material. C: The height of the steel ball when the steel ball was dropped and rebounded was higher in the interior material for automobiles.

(E) Recyclability The recyclability of the obtained interior material for automobiles 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 decomposing it for each constituent material. B: If the obtained automotive interior material is decomposed for each constituent material, all can be used for recycling. C: The obtained automotive interior materials include materials that cannot be used for recycling.

Example 2 In place of the laminate used in Example 1, a suede-like synthetic leather made of polyester fiber (Exaine: trade name, manufactured by Toray Industries, Inc.) and an extruded polypropylene resin foam sheet (expansion ratio: 20) Double, 2.5 mm thick), the synthetic leather surface of the laminated sheet is adhered to the inner surface of a flat mold, and the other mold is made of a polypropylene frame (1.5 mm in diameter). Rectangular shape holder (fresh 25
0 mm, width 750 mm), except that an interior material for an automobile was obtained in the same manner as in Example 1.

Example 1 shows the physical properties of the obtained interior material for automobiles.
It investigated similarly to. Table 1 shows the results.

Example 3 A pile-like sheet (thickness 2) made of polypropylene fiber
mm) and a polypropylene-based resin extruded foam sheet (expansion ratio: 20 times, thickness: 3.5 mm), and the pile-like sheet surface of the laminate was adhered to the inner surface side of a flat mold.

A mold B having a steam hole (300 mm long)
, 800mm wide, 60mm deep)
Except for having a polyolefin-based resin hook (surface coating: chlorinated polypropylene) for fixing a set screw as an attachment portion, the same shape holding material as that used in Example 1 was inserted and fixed.

Eperan PP (produced by Kanegafuchi Chemical Industry Co., Ltd., trade name, expansion ratio: 30) was filled as a polypropylene resin pre-expanded particle into a mold via a feeder.

Next, water vapor (vapor pressure of 0.
5 kg / cm ² · G, temperature 109-113 ° C.) is introduced into the mold, pre-heated, depressurized and steamed the pre-expanded particles for 10 seconds, and then the internal pressure in the mold becomes 260 mmHg or less. Using a vacuum pump, the drain and water vapor were removed by suction.

After that, steam (steam pressure 3.2 kg / cm ² · G, temperature 144-146 ° C.) was introduced into the mold from the molds A and B, kept for 20 seconds, cooled, and then cooled. I opened the mold and got the interior material for the car.

Example 1 shows the physical properties of the obtained interior material for automobiles.
It investigated similarly to. Table 1 shows the results.

Example 4 In Example 3, Eperan PP (manufactured by Kaneka Chemical Co., Ltd., trade name:
Except for using an expansion ratio of 15), in the same manner as in Example 3,
From the filling of the pre-expanded particles to the suction and removal of the drain and water vapor were performed.

Next, water vapor (vapor pressure of 3.
(5 kg / cm ² · G, temperature: 146 to 148 ° C.) was introduced into the mold, kept for 20 seconds, cooled, and then the mold was opened to obtain an automobile interior material.

Example 1 shows the physical properties of the obtained interior material for automobiles.
It investigated similarly to. Table 1 shows the results.

Example 5 In Example 1, polypropylene was used in the same manner as in Example 1 except that a flat mold was used as the mold having the steam holes, and no shape-retaining material was provided on the inner surface of the mold. An in-mold resin foam was obtained.

Next, the in-mold foam surface of the obtained in-mold foam molded product and a polypropylene frame (diameter: 1.5 mm
) Made of rectangular shape (250mm long, 7mm wide)
50 mm) and bonded to each other by heating and melting the respective adhesive surfaces to obtain an automotive interior material.

Example 1 shows the physical properties of the obtained interior material for automobiles.
It investigated similarly to. Table 1 shows the results.

Comparative Example 1 A foamed product in a polypropylene-based resin mold was obtained in the same manner as in Example 1 except that after preheating, the drain and the water vapor were suctioned and removed without steaming.

The physical properties of the obtained in-mold foam molded article were measured in Example 1.
It investigated similarly to. Table 1 shows the results.

Comparative Example 2 A foamed product in a polypropylene resin mold was obtained in the same manner as in Example 3 except that steaming was not performed after preheating.

The physical properties of the obtained in-mold foam molded article were measured in Example 1.
It investigated similarly to. Table 1 shows the results.

Comparative Example 3 In Comparative Example 2, except that the preliminary heating was not performed,
In the same manner as in Comparative Example 2, a foamed product in a polypropylene resin mold was obtained.

The physical properties of the obtained in-mold foam molded article were measured in Example 1.
It investigated similarly to. Table 1 shows the results.

[0100]

[Table 1]

As is evident from the results shown in Table 1, according to the method of manufacturing the interior material for automobiles of Examples 1 to 5 of the present invention, when the extruded foam sheet having no air permeability is used. Even when the in-mold foam is produced from the pre-expanded particles, the laminate and the in-mold foam can be integrated with good adhesiveness in a short time, and the obtained in-mold foam molded article is It can be seen that the pre-expanded particles are excellent in fusing property.

Further, it can be seen that the interior materials for automobiles obtained in Examples 1 to 5 have excellent feel, excellent cushioning property, excellent recyclability and the like at the same time.

Further, since the interior materials for automobiles obtained in Examples 1 to 5 are all lightweight, they can sufficiently respond to the demand for reducing the weight of parts constituting the automobile. there were.

[0104]

According to the method for producing an interior material for an automobile of the present invention, an in-mold foam is produced from pre-expanded particles at the same time that an extruded foam sheet having no air permeability is used. The skin material and the in-mold foam can be firmly integrated, and the interior material for automobiles thus obtained has poor fusion bonding even if the thickness of the in-mold foam layer is large. An excellent effect of no occurrence can be obtained.

The interior material for automobiles obtained by the production method of the present invention has a unique high-grade feel and soft touch to the fibrous skin, and gives a soft and supple feel when pressed. It has many excellent effects such as excellent cushioning, light weight, and easy recycling.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a mold used in a production method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mold A 2 mold B 4 steam hole 9 extruded polypropylene-based resin foam sheet 10 fibrous skin 11 laminate 12 shape retention material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 44/00-44/60 B29C 67/20 B32B 5/00-5/32 B60R 13/02

Claims (8)

(57) [Claims] 1. A laminate of a breathable fibrous skin and an extruded polypropylene resin foam sheet is provided so that the fibrous skin is in contact with the inner surface of a mold A, and a shape maintaining material is provided on an inner surface of a mold B. After the mold A and the mold B are clamped to form a mold, a polypropylene resin pre-expanded particle is filled in the mold, and steam is supplied from a vapor hole of the mold B. After preheating the pre-expanded particles at a temperature lower than the temperature at which the pre-expanded particles fuse to each other, the pre-expanded particles are steamed with steam, and then at a temperature higher than the temperature at which the pre-expanded particles are fused to each other. A method for producing an interior material for automobiles, wherein the pre-expanded particles are fully heated from a mold B at a temperature. 2. A laminate of a fibrous skin having air permeability and an extruded polypropylene resin foam sheet is provided so that the fibrous skin is in contact with the inner surface of a mold A, and the mold A and the mold B are separated from each other. After forming the mold by tightening, the polypropylene resin pre-expanded particles are filled into the mold, steam is supplied from the vapor holes of the mold B, and the temperature is lower than the temperature at which the pre-expanded particles are fused to each other. It was pre-heating the pre-expanded particles at a lower temperature
Thereafter , the pre-expanded particles were steamed with steam, and then the pre-expanded particles were fully heated from the mold B at a temperature equal to or higher than the temperature at which the pre-expanded particles were fused to each other, and the mold was opened to obtain a mold. A method for producing an interior material for an automobile, comprising: providing a shape retaining material on a surface of the in-mold foam on a side where the laminate is not provided. 3. The method according to claim 1, wherein the main heating is performed from the mold A when the main heating is performed from the mold B. 4. The method for producing an interior material for an automobile according to claim 1, wherein the pre-expanded particles are steamed, the drain is removed, and then the main heating is performed. 5. The method for producing an interior material for an automobile according to claim 1, wherein a laminate formed in advance is used. 6. The method for producing an interior material for an automobile according to claim 1, wherein after forming the laminate in a molding die, pre-expanded polypropylene resin particles are filled in the molding die. 7. The fibrous skin is made of a polyolefin resin fiber.
A method for producing an interior material for an automobile according to the above. 8. The method for producing an interior material for an automobile according to claim 1, wherein the fibrous skin is made of a polyester resin fiber.