JPS63291748A - Trim for automobile - Google Patents

Abstract

PURPOSE:To obtain an even product surface as for a trim consisting of a foaming body with a surface skin layer and a core material press-attached in a body to its back, by stick-attaching a compressed urethane given a compressed processing of a specific compressibility to the strike-contacting surface side of the foaming body of the core material. CONSTITUTION:A surface skin layer 11 is formed along the mold surface of a mold after PVC resin powder has been stuck to the slush formation mold and then heating and gelation have been done. Also, a foaming body 12 is formed as a layer to the surface skin layer 11 by mixing a proper quantity of a foaming agent into PVC resin powder and foaming it and cooling it into solidification. Meanwhile, a sheeting consisting of polypropylene compound resin material is heated and softened, and then formed into a needed shape by means of cold press forming and a core material 14 is made, and a compressed urethane 13 is stuck in a body to the core material 14 through an adhesive agent 15. And this core material 14 is united with the foaming body 12 through an adhesive agent 16 and a trim desired is obtained. This compressed urethane 13 is made to be of 50-80% compressibility and of 0.05-0.10g/cm<3> density.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to interior parts for automobiles such as door trims and instrument pads, and particularly to interior parts for automobiles that have good product appearance and ensure uniform product thickness.

(Prior art and its problems) Slash molding has traditionally been widely used as a manufacturing method for interior parts that require relatively good surface appearance and surface feel, such as automotive interior parts such as door trims and instrument pads. has been done.

An example of a method for producing interior parts for automobiles using this type of slush molding is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-32720@.

As shown in Fig. 5, a non-foaming sol is attached to the inner surface of a slush molding mold and gelled to form a skin layer 2 on the inner surface of the mold 1. Plastisol mixed with a foaming agent is gelled on the upper surface of the layer 2 to form a foam @3, and when the foamed layer 3 is in a softened state, a core material 4 made of a resin molded body or a composite resin molded body is added from above. is set, the foam layer 3 and this core material 4 are integrated, cooled and demolded to obtain an automobile interior part.

However, according to this manufacturing method, due to variations in the mold temperature of the slush mold, the PVC resin powder does not adhere uniformly within the mold, and in particular, the thickness of the foam layer 3 cannot be uniformly controlled. When integrated with the foam, there is a problem that variations occur in the product board thickness, and furthermore, air is present at the bonding surface between the foamed @ 3 and the core material 4, causing unevenness on the surface of the skin layer 2. There was a drawback that a good product appearance could not be obtained.

Furthermore, since the core material 4 is set from above when the foamed M3 is in a softened state, there is no place for the gas produced by the foaming reaction of the foamed layer 3 to escape, causing voids, which deteriorate the product appearance as described above. It also becomes the basis of defects.

In addition, a so-called mold forming method in which a hard urethane resin liquid is poured into a mold has been proposed as a method for forming the core material, but this method does not improve the bonding strength between the foam and the core material and the surface appearance. However, the core material made of hard urethane has strength problems, and in order to obtain the necessary mechanical strength, it must be made thicker, which limits the shape of the material.
It also has the disadvantage of increasing weight.

Moreover, the hard urethane core material requires large-scale specialized equipment for urethane injection and foaming, which has been pointed out as a problem that increases costs.

As a countermeasure for these issues, the applicant first filed a patent application in 1986-230.
No. 779 discloses an automobile in which a cushioning material is laminated on the surface of the core material that is bonded to the back surface of the foam, and by utilizing the elasticity of the cushioning material, the product appearance is good and the thickness of the product is uniform. The company has filed an application for interior parts.

However, even in this case, when a slab urethane foam is used as a cushioning material, the adhesive between the foam layer and the slab urethane foam (particularly the solvent in the adhesive) may enter the slab urethane foam during pressure molding. However, some of the cells are adhered while being pressed into a flat shape, resulting in problems such as unevenness on the product surface.

Furthermore, the adhesive between the slab urethane foam and the core material binds the press-molded parts together, and also penetrates into the slab urethane foam and binds the cells in the slab urethane foam, but due to changes over time, Particularly in high temperature conditions, this adhesive force weakens, and the slab urethane foam recovers due to its elastic force, resulting in similar unevenness on the surface of the product.

In addition, these soft slab urethane foams gave a feeling of bottoming out when pressed strongly, and the surface feel was not very satisfactory.

(Object of the invention) The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to improve the product surface of the previous application so that unevenness does not occur on the surface of the product, and the product has a bottom. To provide interior parts for automobiles that have an extremely excellent surface feel without feeling.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention includes a skin layer formed by adhering PVC resin powder to the mold surface of a slush mold, and a foaming agent applied to the upper surface of this skin layer. Contaminated PV
For automobiles, it is composed of a foam with a skin layer, which is formed by laminating a foam with C resin powder adhered thereto, and a core material, which is bonded to the back side of the foam and integrated with the foam with a skin layer by pressure bonding. The interior parts are characterized in that compressed urethane having a density of 0.05 to 0.109/cm 3 and subjected to compression processing with a compression rate of 50 to 80% is adhered to the foam contacting surface of the core material. shall be.

That is, according to the above configuration, the foam abutting surface of the core material has a density of 0.05 to 0.05% compressed to a compression ratio of 50 to 80%.
Since the compressed urethane of 109/cm3 is attached, at the stage of forming the foam by slush molding,
Even if the wall thickness of the foam becomes uneven, or even if so-called voids occur, where the gas generated during the foaming reaction remains inside the foam, the elastic action of compressed urethane will prevent the wall thickness variation of these foams from occurring. In addition, in conventional slab urethane foam, both the adhesive for the foam and the adhesive for the core material migrate into the slab urethane foam, causing unevenness on the surface. occurs or
There were problems such as not being able to obtain the specified thickness due to the urethane foam being restored, but in this application, the urethane foam is compressed at a predetermined magnification to make it highly dense, so the negative effects of these adhesives can definitely be avoided. This has the advantage that an extremely good product appearance can be obtained without causing similar unevenness on the surface of the skin layer, and that the thickness of the product can be maintained almost uniform.

Furthermore, compressed urethane, which is made by compressing urethane foam, is superior to general-purpose slab urethane foam in terms of strength such as tensile strength, so it can handle more complex shapes of products and has a greater degree of freedom in shaping. In addition to this, even when the product surface is pressed strongly, there is no feeling of bottoming out and the product has a good feel.

(Description of Examples) Hereinafter, examples in which the present invention is applied to an automobile door trim will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a door trim for an automobile to which the present invention is applied, and FIGS. 2 to 4 are explanatory views showing the manufacturing process of the door trim.

In FIG. 1, an automobile door trim 10 has a skin layer 1.
11 Foam 12. Compressed urethane 13. It is generally composed of a laminated structure of a core material 14.

More specifically, the skin @ 11 is formed along the mold surface of the mold by attaching PVC resin powder to a slush molding mold, which will be described later, and then heating it to gel. An appropriate amount of a foaming agent such as azodicarbonamide is mixed into the powder, foamed by a heating means such as a heater, and then cooled and solidified to form the foam 1 on the skin layer 11.
2 are laminated.

In this embodiment, a polypropylene composite resin material is used as the core material 14, and a mixture of polypropylene resin and wood powder filler in an appropriate mixing ratio is extruded into a sheet by an extrusion molding machine, and at the same time, it is applied to the mold surface. A film-like hot melt adhesive 15 is laminated. After softening the sheet by heating, it is molded into a desired shape by cold press molding, and compressed urethane 13 is integrally attached via adhesive 15.

The elastic action of the compressed urethane 13 can effectively absorb variations in the thickness of the foam 12 and voids caused by gas generated during the foam 12 formation stage.

Furthermore, this compressed urethane 13 is characterized by compressing a thermocompression molding type urethane foam to improve its density and tensile strength.For example, in this embodiment, thermoforming foam 330F (LBL ) r
The material used is one manufactured by Jishiki Boseki Co., Ltd., which is 6M thick and has been compressed by 50% to a plate thickness of 3Mn by heat compression.

Note that the material of the compressed urethane 13 is not limited to that of the above-mentioned embodiments, and may have a density of 0.0 after compression processing.
It has been found through tests by the inventors that a compression ratio of 5 to 0.10 g/cm3 is sufficient, and that good results can be obtained if the compression ratio is 50 to 80%.

As shown in FIG.
Although the thickness of the foam 12 is not uniform, such as in the areas 2a and 12b where the thickness is thin, when the foam 12 and the core material 14 are bonded together using the adhesive 16, the thickness of the foam 12 is not uniform. The compressed urethane 13 at the portions corresponding to the thicker portions 12a is strongly compressed, and conversely, the thinner portions 12 of the foam 12
Since the compressed urethane 13 in the portion corresponding to b is not compressed so much, the thickness of the product as a product is unified to be approximately uniform.

Furthermore, since the compressed urethane 13 is made by compressing urethane foam and has dense internal cells, it is extremely unlikely that the solvent in the adhesive 15 or 16 will migrate into the compressed urethane 13. Epidermal layer 11 due to the influence of
It is possible to provide a product with extremely good surface appearance and surface feel without unevenness or swelling and recovery of the compressed urethane 13.

And, while this compressed urethane 13 has a maximum elongation of 180% for high-density urethane (those with a density of 0.05'ii/ctn3), the elongation of this compressed urethane 13 is 250 to 260% at the same density. When integrally molded with the core material 14, it easily follows even if the shape of the core material is a complicated curved surface, and there is no problem such as tearing of the compressed urethane 13.

Furthermore, after conducting a thermal cycle test under the following conditions on a laminate in which the compressed urethane 13 of the present invention was laminated to the core material 14 and a laminate in which the core material was laminated with a normal slab urethane foam, it was found that the compressed urethane 13 of the present invention was tested under the following conditions. The thickness of the slab urethane frame has only slightly recovered from 2 mm to 2.1 mm, whereas the conventional product has a slab urethane frame thickness of 2.0 mm.
．． It has become clear that the results are significantly restored in order of 6.

(Heat cycle test) 90'C/4h → room temperature 0.5h → -40°C/1°5h →
Room temperature 10.5h → 70℃, 95%RH/3h → Room wet 10
．． Changes in the thickness of the compressed urethane and slab urethane foams were measured after 4 cycles, where one cycle was 5 hours→-40'C/1.5 hours→room temperature 10.5 hours.

As a result of the above, when the compressed urethane 13 of the present invention is used, since the cells have a dense structure, there is almost no migration from the adhesive 15, 16, no unevenness occurs on the surface of the skin layer 11, and there is no change over time. Restoration due to cell separation does not occur, and uniform board thickness can be guaranteed over a long period of time.

And since it is made of high-density urethane that has been compressed, its tensile strength is increased, which improves the degree of freedom in molding.
In addition, since it has a suitable amount of stiffness, it does not give the feeling of bottoming out when pressed hard, and can provide good cushioning properties, so the product of the present invention has high practical value.

Next, the manufacturing process of the automobile door trim 10 will be explained based on FIGS. 2 to 4 for reference.

The manufacturing process of the door trim 10 is roughly divided into the following three processes.

■ Molding process of foam with skin layer.

■Molding process of core material.

■Integration process of foam and core material.

Next, each step will be explained in detail.

■ Molding process of foam with skin layer.

First, after heating the slush molding mold 17 to a temperature higher than the melting point of the PvC resin (230° C. in this example), PVC resin powder is deposited inside the slush molding mold 17. If you let it gel,
A soft skin layer 11 is formed in a shape along the mold surface of the mold 17 (see Figure 2 (a)).The excess PVC resin powder is recovered by reversing the mold 17. .

Thereafter, PVC resin powder mixed with a foaming agent such as azodicarbonamide is attached to the upper surface of this skin layer 11, and after recovering the excess powder by inverting the mold 17, the foaming agent is heated by the heater 18. The powder is allowed to undergo a free foaming reaction, and as shown in FIG. 2(b), the foam 12 is laminated on the upper surface of the skin layer 11 to form a foam with a skin layer.

■Molding process of core material.

The core material 14 is made by extruding a mixture of polypropylene resin and wood powder filler in an appropriate ratio into a sheet using a T-die extrusion molding machine, and during the core material extrusion molding, a film-like hot melt adhesive 15 is applied to one side. Laminate it.

After heating and softening the core material 14, the core material is compressed urethane 13, which is obtained by heat-compressing the above-mentioned aged type fume 330F (LBL) with a thickness of 6 cm to a thickness of 3 mm. 14 Hot melt adhesive 15 Overlaid on the laminate side, cold press mold 19 of desired shape
The compressed urethane 13 is integrated into the core material 14 by press molding (see FIG. 3). At this time, the thickness of the compressed urethane 13 is approximately 2 mm.

■Integration process of foam and core material.

A foamed body 12 with a skin layer 11 formed in the above steps ① and ②, and a core material 14 with compressed urethane 13 attached to the negative side.
are integrated via adhesive 16.

That is, the foam 12 is placed on the lower mold 2Oa of the mold 20 so that the skin layer 11 is located on the lower side.

On the other hand, the core material 14 is set in the press upper die 20b so that the compressed urethane 13 faces downward.

After applying the adhesive 16 to the surface of the foam 12,
The upper press mold 20b is engaged with the lower press mold 20a, and the skin layer 11 is formed within the clearance between the upper and lower press molds 20a and 20b.
The foamed body 12 and the core material 14 may be integrally bonded together.

At this time, as described above, variations in the wall thickness of the foam 12 and voids within the foam 12 are effectively absorbed by the elastic action of the compressed urethane 13, and the product thickness of the automobile door trim 10 is maintained almost uniform. In addition, since the compressed urethane 13 has a high density, the adhesive 15, 16 does not migrate into the compressed urethane 13, and the compressed urethane 13
does not swell even over time. Therefore, an automobile door trim with extremely good surface appearance can be obtained. Moreover, the compressed urethane 13 has excellent cushioning properties and moldability, improves the surface feel, and dramatically increases the degree of freedom in shaping the product.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an automobile door trim to which the present invention is applied, Figs. 2 to 4 are explanatory diagrams showing the manufacturing process of the automobile door trim, and Fig. 5 shows the structure of a conventional automobile interior part. FIG. 10...Automotive door trim 11...Skin layer 12...Foam 13...Compressed urethane 14...Core material 15.16...Adhesive 17...Mold for slush molding 18. ... Heater device 19 ... Cold press mold 20 (20a, 20b) ... Press mold patent applicant Kasai Kogyo Co., Ltd. agent Patent attorney Kazu 1) Rules Figure 1 Figure 2 (Q) l Figure 2(b) Figure 4

Claims (1)

[Claims] (1) A skin layer formed by adhering PVC resin powder to the mold surface of a slush mold, and a laminated foam formed by adhering PVC resin powder mixed with a foaming agent to the upper surface of this skin layer. An interior part for an automobile comprising a foam with a skin layer, and a core material that is bonded to the back side of the foam and integrated with the foam with a skin layer, wherein the foam contacting surface of the core material An interior part for an automobile, characterized in that compressed urethane having a density of 0.05 to 0.10 g/cm^3 is adhered to a material that has been subjected to compression processing with a compression rate of 50 to 80%.