JP2002283521A - Laminated resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a laminated resin molding capable of reducing a using amount of an expensive resin material for constituting a skin material without interposing an adhesive between the skin material and a foamed layer and further enhancing the heat resistance of the skin material. SOLUTION: The laminated resin molding 1 comprises the skin material 7 made of a plurality of thermoplastic resin layers and powder slush molded, and the foamed layer 8 made of a polyurethane resin and integrally molded. The skin material 7 is integrally molded with a skin surface layer 7a made of an olefin resin material, and a skin rear surface layer 7b made of a resin material obtained by mixing one or more types of heat resistance imparting resin selected from the group consisting of a blended resin of a polypropylene and an ethylene propylene diene copolymer and a polyethylene resin and an adhesive imparting resin formed of a copolymer of an olefin having a carboxyl group and an ethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a powder slash-molded skin material comprising a plurality of thermoplastic resin layers,
The present invention relates to a laminated resin molded article obtained by integrally molding a foamed layer made of a polyurethane resin.

[0002]

2. Description of the Related Art Instrument panels of automobiles include:
There is a laminated resin molded body in which a powder slush molded skin material made of a thermoplastic resin layer and a foamed layer made of a polyurethane resin are integrally molded.

[0003] As such a laminated resin molded product, Japanese Patent Application Laid-Open No. 8-
No. 48201 discloses a non-foamed upper skin layer made of a soft synthetic resin such as a thermoplastic polyolefin elastomer,
A vehicle interior side in which a foam layer such as a polyurethane resin is integrally formed on the back side of a skin material in which the upper skin layer and a subcutaneous layer made of a foamed synthetic resin such as a thermoplastic polyolefin elastomer having compatibility are integrally formed by powder slush molding. A member airbag door structure is disclosed.

[0004] By the way, in order to minimize industrial waste, it is required to use a recyclable resin material. When a recyclable resin material is used for the skin material of the laminated resin molded article as described above, depending on the type of the resin material, the compatibility with the polyurethane resin foam layer on the back surface side is poor and an adhesive is used between the two. In some cases.

[0005] In addition, since the skin material is a portion exposed on the surface and it is desired that the appearance of the skin material is good, an expensive resin material is generally used.

Further, for example, a laminated resin molded article such as an instrument panel of an automobile may be used after being exposed to a high temperature of 110 ° C. or higher.

[0007]

On the other hand, interposing an adhesive between the skin material and the foamed layer of the polyurethane resin requires a large number of man-hours and equipment for the step of applying the adhesive. Therefore, it is not preferable from the viewpoint of mass productivity and manufacturing cost. Further, since an organic solvent harmful to the human body is mixed in the adhesive, it is not preferable from the viewpoint of working environment, and improvement has been demanded.

Further, there has been a demand for an inexpensive skin material having good appearance.

Further, when the laminated resin molded article is exposed to a high temperature, the surface of the skin material is undulated and the appearance is deteriorated, so that the skin material is required to have heat resistance.

The present invention has been made in view of the above points, and has as its object to eliminate the need for an adhesive between a skin material and a foamed layer, and to use an expensive material for forming the skin material. It is possible to reduce the amount of resin material used,
An object of the present invention is to obtain a laminated resin molded article having improved heat resistance of a skin material.

[0011]

In order to achieve the above object, the present invention comprises a plurality of skin materials, of which a back surface layer which comes into contact with a foam layer is made of a heat-resistant resin and an adhesive. It is made of a resin material mixed with a resin to be applied.

Specifically, the present invention provides a powder slush-molded skin material comprising a plurality of thermoplastic resin layers,
It is assumed that a laminated resin molded body is formed by integrally molding a foamed layer made of a polyurethane resin.

The skin material comprises a skin surface layer made of an olefin-based resin material and polypropylene (hereinafter referred to as “P”).
P ") and a blended resin of ethylene-propylene-diene copolymer (hereinafter referred to as" EPDM ") (hereinafter referred to as" PP-EPDM resin ") and a polyethylene resin (hereinafter referred to as" PE resin "). And a skin back surface layer made of a resin material obtained by mixing one or two kinds of heat-resistance-imparting resins and an adhesion-imparting resin formed by a copolymer of an olefin having a carboxyl group and ethylene with each other. It is characterized by the following.

According to the above construction, the adhesion-imparting resin formed of a copolymer of an olefin having a carboxyl group and ethylene is contained in the back surface layer of the skin, and the adhesion-imparting resin is formed by foaming the polyurethane resin. Since it has high adhesiveness to the layer, the skin material and the foam layer are firmly adhered to each other and are integrally formed, and it is not necessary to interpose an adhesive between the skin material and the foam layer. This eliminates the need for an adhesive application step in the manufacturing process, thereby improving the working environment as compared with the conventional method, and also eliminates the need for consumables such as the adhesive itself and a masking material, thereby reducing the manufacturing cost compared to the conventional method. can do. On the other hand, the skin surface layer and the skin back layer are mutually interdiffused at the interface between the two layers by powder slush molding so as to be tightly integrated.

Further, since the skin material is composed of a plurality of layers, an expensive olefin resin is used only for a surface surface layer exposed on the surface, and an inexpensive resin material is used for a back surface layer of the skin. A less expensive skin material can be obtained.

Furthermore, since one or two kinds of heat-resistance-imparting resins selected from PP-EPDM resin and PE resin are contained in the back surface layer of the skin, the heat resistance is enhanced, and Even when exposed to a high temperature, generation of waving on the surface of the skin material due to softening of the skin back surface layer can be suppressed, and deterioration of the appearance of the skin material can be suppressed.

Here, the olefin resin is a resin obtained by polymerizing an alkane, and may be a single olefin polymer such as PP or a copolymer of a plurality of olefins. Alternatively, it may be a mixture of a plurality of polymers such as a PP-EPDM resin.

The adhesiveness-imparting resin formed of a copolymer of an olefin having a carboxyl group and ethylene is not particularly limited. For example, an ethylene methyl acrylate resin (hereinafter referred to as "EMA resin") , Ethylene ethyl acrylate resin (hereinafter "EE
A resin), ethylene acrylic acid resin (hereinafter referred to as “E resin”).
AA resin "), ionomer resin and the like. Each of these resins has a carboxyl group or a carboxyl group derivative at the terminal, and by forming an ester bond with a hydroxyl group of the polyurethane resin, a high adhesive force is formed between the back skin layer and the foam layer. It is considered to be obtained.

The PE resin is not particularly limited. Even if it is a high-density PE (HDPE), a low-density P
E (LDPE) may be used.

The olefin resin, the heat resistance-imparting resin, and the adhesiveness-imparting resin constituting the skin material are all thermoplastic resins and can be recycled.

It is preferable that the mixing mass ratio of the heat-resistance-imparting resin to the adhesion-imparting resin constituting the back skin layer is 8: 2 to 2: 8. According to such a configuration, the balance between both the heat resistance of the back skin layer and the adhesiveness to the foamed layer is improved. That is, when the amount of the heat-resistance-imparting resin is larger than the range of the mixing mass ratio, the adhesiveness to the foamed layer is slightly deteriorated. The properties are slightly inferior. Preferably, the mixing mass ratio is 4: 6 to 6: 4.

Further, both the skin surface layer and the skin back layer may be non-foamed layers. According to this configuration, since the skin back surface layer, which is a non-foamed layer, is hard and has a high shape retention ability, when the foamed layer is molded in the molding process of the laminated resin molded article, the foamed layer is pressed against the foamed layer. Irregularities on the back surface layer of the skin can be prevented from appearing as undulations on the surface layer of the skin and the appearance of the surface of the skin material deteriorating.In addition, the shape retention ability of the skin surface layer is somewhat lower. The thickness can be reduced as much as possible, and an inexpensive skin material can be obtained.

Further, the skin surface layer may be a non-foamed layer, while the skin back layer may be a soft foamed foam layer. According to this configuration, since the skin back surface layer is a soft foamed foam layer, the skin material is rich in elasticity, and the appearance is also soft.

[0024]

As described above, according to the present invention,
The skin material and the foam layer are firmly adhered to each other and are integrally molded, so that there is no need to interpose an adhesive between the skin material and the foam layer, and therefore, an adhesive application step is not required in the manufacturing process. In addition, the working environment can be improved as compared with the related art, and consumables such as the adhesive itself and a masking material are not required, so that the manufacturing cost can be reduced as compared with the related art.

Further, since the skin material is composed of a plurality of layers, an expensive olefin resin is used only for the surface layer exposed on the surface, and an inexpensive resin material is used for the back surface layer. A less expensive skin material can be obtained.

Furthermore, since one or two kinds of heat resistance-imparting resins selected from PP-EPDM resin and PE resin are contained in the back surface layer of the skin, the heat resistance is enhanced, and the appearance of the skin material is improved. The appearance can be prevented from deteriorating.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

(Structure of Instrument Panel) FIGS. 1 and 2 show an instrument panel with partial pads of an automobile as a laminated resin molding according to an embodiment of the present invention.

As shown in FIG. 1, the instrument panel 1 has a pad 3 partially formed integrally with a panel body 2 as a base material.

As shown in FIG. 2, the pad 3 has a skin material 7 on the surface and side surfaces in a concave receiving portion 6 formed of a bottom wall 4 and a side wall 5 formed in the panel body 2. An integrally laminated foam layer 8 is integrally formed on the bottom wall 4.

The skin material 7 is composed of two layers, a skin surface layer 7a and a skin back layer 7b. The skin surface layer 7a is made of PP resin,
It is a non-foamed layer made of a thermoplastic olefin resin material such as a PP-EPDM resin and formed by slush molding the powdered resin material. The back skin layer 7b is
PP-EPDM resin, one or two kinds of heat resistance imparting resin selected from PE resin, EMA resin, EEA resin,
It is made of a resin material obtained by mixing an adhesion-imparting resin formed by a copolymer of ethylene and an olefin having a carboxyl group such as an EAA resin or an ionomer resin, and is formed in a powder form so as to form a layer on the back side of the skin surface layer 7a. Is a non-foamed layer formed integrally with the skin surface layer 7a by slush molding the resin material. The ratio of the heat-resistance-imparting resin to the adhesion-imparting resin, which is the mixing mass ratio of the heat-resistance-imparting resin to the adhesion-imparting resin, is from 8: 2 to 2: 8. Skin surface layer 7
Since the resin material constituting both the layer a and the skin backside layer 7b is an olefin-based resin, the compatibility is high, and the resin is interdiffused at the interface between them, and the two are tightly adhered and integrated. The edge of the skin material is a skin bent portion 7c bent to the back surface
The surface of the skin bending portion 7c is in thick contact with the side wall 5 of the storage portion 6 by the force of the foam layer to expand.

The foam layer 8 is a hard layer made of a polyurethane resin formed by reacting and curing a polyurethane resin material obtained by adding a foaming agent to a polyol and a polyisocyanate.

The panel body 2 is formed by injection-molding a PP resin material. The bottom wall 4 of the housing section 6 has an opening 6a into which a polyurethane resin material is injected when the pad 3 is formed.

(Method of Manufacturing Instrument Panel) Next, a method of manufacturing the instrument panel will be described.

<Skin-forming step> A powdery olefin-based resin material is put into a heated skin-forming mold, and the powdered olefin-based resin material is mutually welded to form a skin surface layer 7a.

Next, a powdery resin material obtained by mixing a heat-resistance-imparting resin and an adhesion-imparting resin is put on the semi-molten skin surface layer 7a formed in the skin mold, and the powder-like resin material is removed. The skin back surface layer 7b is formed by mutually welding. At this time, the skin surface layer 7a and the skin back layer 7b are integrated by interdiffusion of the respective resin materials at the interface between the two layers.

After the mold is cooled, the skin material 7 in which the skin surface layer 7a and the skin back layer 7b are integrally formed is taken out of the mold.

<Panel Body Molding Step> A pellet-shaped PP resin material is put into a hopper of an injection molding machine, melted and kneaded in a cylinder, and the molten PP resin is injected into a panel body molding die.

After the mold is cooled, the mold is opened,
The molded panel body 2 is taken out of the mold.

<Foam Layer Forming Step> The powder slush-molded skin material 7 is set so that the skin surface layer 7a is in contact with the lower mold of the mold. Further, the injection molded panel main body 2 is set so that the back surface thereof is in contact with the upper mold of the molding die.

Subsequently, the upper mold and the lower mold are closed, and thereafter, the back surface layer 7b of the skin material 7 and the bottom wall 4 of the panel body 2 are closed.
The foamable polyurethane resin material is injected from the injection port 6a into the storage section 6 formed between the above. At this time, the polyurethane resin material undergoes a curing reaction while foaming, and the housing portion 6 is filled with the polyurethane resin. Further, the skin material 7 and the foam layer 8 are integrated by reacting a carboxyl group of the adhesion-imparting resin contained in the skin back surface layer 7b with a hydroxyl group of the polyurethane resin of the foam layer 8 to form an ester bond. .

Then, the mold is opened, and the instrument panel 1 on which the pad 3 is integrally formed is taken out of the forming die.

(Function / Effect) According to the instrument panel 1 having the above structure, the adhesion imparting resin formed by the copolymer of olefin having a carboxyl group and ethylene is contained in the back skin layer 7b. Since this adhesiveness-imparting resin shows high adhesiveness to the polyurethane resin foam layer 8, the skin material 7 and the foam layer 8 are firmly adhered to each other and are integrally formed, and the skin material 7 and the foam layer 8 are formed. There is no need to interpose an adhesive between them. This eliminates the need for an adhesive application step in the manufacturing process, thereby improving the working environment as compared with the conventional method, and also eliminates the need for consumables such as the adhesive itself and a masking material, thereby reducing the manufacturing cost compared to the conventional method. can do.

Further, since the skin material 7 has a plurality of layers,
By using an expensive olefin-based resin only for the skin surface layer 7a exposed on the surface and using an inexpensive resin material for the skin back layer 7b, it is possible to obtain the skin material 7 as a whole which is less expensive than before.

Further, since one or two kinds of heat-resistance-imparting resins selected from PP-EPDM resin and PE resin are contained in the skin back surface layer 7b, the heat resistance is enhanced.
Even if the instrument panel 1 is exposed to a high temperature, generation of waving on the surface of the skin material 7 due to softening of the skin back surface layer 7b can be suppressed, and deterioration of the appearance of the skin material 7 can be suppressed.

In addition, since the mixing mass ratio of the adhesiveness-imparting resin to the heat-resistance-imparting resin constituting the skin-backside layer 7b (adhesion-imparting resin: heat-resistance-imparting resin) is 2: 8 to 8: 2, The balance between both the heat resistance of the layer 7b and the adhesiveness to the foam layer 8 is improved.

Further, the skin surface layer 7a and the skin back layer 7b
Are non-foamed layers, and the skin back surface layer 7b, which is a non-foamed layer, is hard and has a high shape retention ability, so that the foamed layer 8 is formed in the step of forming the pad 3 of the instrument panel 1. In this case, the influence of foaming is
a can be prevented from deteriorating the appearance of the skin material 7 due to the appearance of the skin material 7 as a wave, etc.
Since the shape retention ability of a may be low, the thickness can be reduced as much as possible, and an inexpensive skin material 7 can be obtained.

Further, all of the olefin resin, the heat resistance-imparting resin and the adhesiveness-imparting resin constituting the skin material 7 are thermoplastic resins, which can be recycled, and are preferable from the viewpoint of reducing industrial waste.

(Other Embodiments) In the above embodiment,
Although the outer skin layer 7b of the outer skin material 7 is a non-foamed layer, the present invention is not limited to this. By adding a foaming agent to a resin material constituting the outer skin layer and subjecting it to powder slush molding, The back surface layer of the skin material may be a soft foam layer. According to this configuration, the appearance of the skin surface layer of the skin material has a soft appearance.

In the above embodiment, the laminated resin molded body and the instrument panel 1 are used. However, the present invention is not limited to this. For example, a door trim of an automobile, a console lid, or the like may be used.

[0051]

EXAMPLES (Test evaluation sample) PP-E
PDM resin and the back surface layer of the skin
A plate-like sample for test evaluation was prepared by integrally molding a skin material formed of E resin and a foam layer made of polyurethane urethane resin.

Further, a skin material and a polyurethane urethane resin are respectively formed by molding the surface layer of the skin with a PP-EPDM resin and the back layer of the skin with a blend resin of a PE resin as a heat resistance-imparting resin and an EAA resin as an adhesion-imparting resin. A plate-like sample for test evaluation was prepared by integrally molding a foam layer made of At this time, nine kinds of test evaluation samples were prepared in which the mixing mass ratio of the PE resin and the EAA resin was changed from PE resin: EAA resin = 9: 1 to 1: 9. Nine types of test evaluation samples were prepared for each of those using an ionomer resin instead of the EAA resin and those using the EEA resin.

Further, a plate-like test in which a skin material formed of a PP-EPDM resin for the skin surface layer and an EAA resin which is an adhesion-imparting resin for the skin back layer, respectively, and a foamed layer made of polyurethane urethane resin were integrally formed. An evaluation sample was prepared. For those using an ionomer resin instead of EAA resin and those using EEA resin,
Each sample for test evaluation was prepared.

(Test Evaluation Method) With respect to each test evaluation sample, the adhesive strength when a 25 mm-wide skin material was peeled from the foam layer was measured.

The temperature of each sample for test evaluation was raised in a gear oven, and the temperature at which appearance defects such as undulation, bleeding, gloss (bleeding), or chemical bleeding appeared on the surface of the skin material was recorded. did.

(Test Evaluation Results) FIG. 3 and Table 1 show the relationship between the mixing mass ratio of the heat resistance-imparting resin and the adhesion-imparting resin and the adhesive strength for each type of the adhesion-imparting resin.

FIG. 3 shows that among the three types of adhesiveness-imparting resins, the EAA resin has the highest adhesive strength, and then the ionomer resin and the EEA resin have the lowest adhesive strength. In addition, it can be seen that the case where the back surface layer of the skin is formed of PE resin alone does not adhere to the foam layer. Further, in the case of any of the adhesiveness-imparting resins, up to about 5: 5 of the heat-resistance-imparting resin: the adhesiveness-imparting resin, the adhesive strength is improved as the mixing ratio of the adhesiveness-imparting resin is increased, but the adhesion is further increased. It can be seen that even if the mixing ratio of the property-imparting resin is increased, the adhesive strength cannot be further improved. This is because the adhesive strength between the skin back layer and the foam layer increases, and when the skin material is peeled off, the foam layer is mainly broken, and the strength of the foam layer is measured as the adhesive strength. Conceivable. The destruction of the foamed layer occurred when the adhesive strength became greater than 5N, that is, when the heat-resistance-imparting resin was composed of 80% or more and the adhesiveness-imparting resin was composed of 20% or less of the skin back layer.

FIG. 4 and Table 2 show the relationship between the mixing mass ratio of the heat-resistance-imparting resin and the adhesion-imparting resin and the temperature at which the appearance failure occurs for each type of the adhesion-imparting resin.

FIG. 4 shows that among the three types of adhesion-imparting resins, the EAA resin has the highest heat resistance, and then the ionomer resin and the EEA resin have the lowest heat resistance. In addition, in any of the adhesiveness-imparting resins, it can be seen that the heat resistance decreases as the mixing ratio increases. For example, the instrument panel of a car is 110
The temperature rises to at least ℃, and in order to withstand such a temperature, the heat-resistance-imparting resin may be constituted by 20% or more and the adhesion-imparting resin is constituted by 80% or less.

[0060]

[Table 1]

[0061]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a perspective view of an instrument panel as a laminated resin molded product according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a graph showing a relationship between a mixing mass ratio of a heat resistance imparting resin and an adhesion imparting resin and an adhesive strength.

FIG. 4 is a graph showing a relationship between a mixing ratio of a heat-resistance-imparting resin and an adhesion-imparting resin and an appearance deterioration temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument panel (laminated resin molded body) 2 Panel main body 3 Pad (laminated resin molded body) 4 Bottom wall 5 Side wall 6 Housing part 6a Injection hole 7 Skin material 7a Skin surface layer 7b Skin back layer 7c Skin bending part 8 Foam layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B32B 27/40 B32B 27/40 B60K 37/00 B60K 37/00 A // B29K 23:00 B29K 23:00 75:00 75:00 105: 04 105: 04 B29L 31:58 B29L 31:58 F-term (reference) 3D044 BA01 BA11 BB01 BC04 4F100 AK01C AK03B AK04C AK07C AK51A AK70C AK71C AK75C AL05C AL07C BA03 BA07 BA10A BA01B DJ01E01 EC03 DJ01E01 EH312 EJ02 EJ022 GB33 JJ03 JJ03C JL12C 4F213 AA03 AA04 AA04E AA09K AA11K AA20E AA22 AA31 AH26 WA03 WA05 WA18 WA43 WA92 WB01 WB22 WC01 WE02 WE06 WE07 WF01 WF06 WK03 WW01

Claims (4)

[Claims] 1. A laminated resin molded article obtained by integrally molding a powder slush molded skin material composed of a plurality of thermoplastic resin layers and a foamed layer composed of a polyurethane resin, wherein the skin material is an olefin-based resin. A skin surface layer made of a material, a blend resin of polypropylene and an ethylene-propylene-diene copolymer, one or two kinds of heat-resistance imparting resins selected from polyethylene resins, and an olefin having a carboxyl group and ethylene. And a skin back surface layer made of a resin material mixed with an adhesiveness-imparting resin formed of a copolymer of (1) and (2). 2. The laminated resin molding according to claim 1, wherein a mixing mass ratio of the heat resistance-imparting resin to the adhesiveness-imparting resin constituting the back skin layer is 2: 8 to 8: 2. body. 3. The laminated resin molded product according to claim 1, wherein the skin surface layer and the skin back layer are both non-foamed layers. 4. The laminated resin molded article according to claim 1, wherein the skin surface layer is a non-foamed layer, while the skin back layer is a soft foamed foam layer.