JP3753241B2 - Planar laminated molded body - Google Patents

Description

なお、上記の表１において、ＰＥはポリエチレンを、ＨＭはホットメルトシートを、ＣＰはスナップボタン型のＰＰ製綴じ具を、ＮＥは粘着シートを、ＦＥはフィッシュアイをそれぞれ意味する。
【００２７】
実施例３
ダイを介して２台の押出機を連結し、一方の押出機に実施例１のポリプロピレンを供給し、他方の押出機に実施例１のポリプロピレン系熱可塑性エラストマーと発泡剤Ａとの混合物を供給し、その他は実施例１と同様に押出し、この押出しと同時に厚さ２mmのポリプロピレンシートと厚さ２mmの熱可塑性発泡シートとを直接積層し、上記のポリプロピレンシートを表皮層とし、ポリプロピレン系の熱可塑性発泡シートをクッション層とする実施例３の面状積層成形体を得た。得られた面状積層成形体は、表皮層とクッション層の密着性が良好であり、１８０度剥離テストでは、クッション層の熱可塑性発泡シートが破断した。
【００２９】
【発明の効果】
上記のとおり、この発明に係る面状積層成形体は、従来品と同様に自動車の内装品、家電製品その他の部品として用いることができ、しかもリサイクルのために再溶融を行った際にゲル点やフィッシュアイが発生しないので、外観が良好で、伸度等の物性低下が少ないリサイクル品が得られる。 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recyclable planar laminate formed by backing a thermoplastic resin skin layer with a thermoplastic foam layer.
[0002]
[Prior art]
Thermoplastic resins such as polypropylene, polystyrene, ABS resin, and polycarbonate are widely used in automobile interior parts, home appliances, and other fields because of their good moldability. In order to improve the tactile sensation of products made of these thermoplastic resins or to prevent unpleasant squeak noise caused by vibrations of automobiles, etc., foam of rubber, polyurethane, etc. on the skin layer made of the above thermoplastic resins It is known to provide a cushion layer by lining a sheet.
[0003]
However, conventionally, a crosslinked foam that has been crosslinked at the same time as foaming is used as the foam, and a sheet made of the crosslinked foam is pasted to the back surface of the molded article made of the thermoplastic resin with a gel-based pressure-sensitive adhesive sheet. Therefore, when melted for recycling, gel points and fish eyes are generated in the melt, and in order to prevent this, the cross-linked foam is peeled off prior to melting, and only the skin layer, which is a molded body of thermoplastic resin, is removed. It had to be melted and was generally considered unrecyclable.
[0004]
[Problems to be solved by the invention]
The present invention is a planar laminated molded body in which a skin layer of a thermoplastic resin is lined with a foam layer, and can be recycled. It is not necessary to peel off the foam layer at the time of recycling. It is intended to obtain a recycled product which does not generate gel points or fish eyes when remelted, has a good appearance, and has little deterioration in physical properties such as elongation.
[0005]
[Means for Solving the Problems]
Planar molded laminate according to the present invention, a cushion layer on the rear surface of the skin layer of a thermoplastic resin composed of a thermoplastic foam of a thermoplastic elastomer are the product layer by adhesion directly above the skin layer is a polypropylene resin It consists, characterized Rukoto such subjected to dynamic crosslinking to the mixture of the thermoplastic elastomer constituting the cushion layer is polypropylene and ethylene-propylene rubber or butyl rubber. However, the above skin layer and cushion layer can be bonded via a hot melt adhesive having compatibility with the skin layer and cushion layer instead of the above direct bonding.
[0006]
In the above-mentioned planar laminated molded body, the skin layer made of thermoplastic resin is lined with a cushion layer made of thermoplastic foam of thermoplastic elastomer, so this molded body is used for automobile interior parts, home appliances and other parts. When used as, it is possible to give a flexible tactile sensation as in the conventional case, and no unpleasant sound due to vibration is generated. And, since the skin layer and the cushion layer are compatible with each other, when remelting for recycling, gel points and fish eyes do not occur. And a recycled product with little deterioration in physical properties such as elongation can be obtained.
[0007]
The thermoplastic resin and the thermoplastic elastomer used in the present invention are arbitrary as long as they are compatible with each other. However, the thermoplastic resin is easy to mold, has excellent molded product performance, and is easily available. In view of the above, olefinic resins, particularly polypropylene resins and polyethylene resins are preferred. On the other hand, any thermoplastic elastomer may be used as long as it is dynamically cross-linked and does not produce fish eyes when melted, and is compatible with the above thermoplastic resin. As the thermoplastic elastomer in the case of the system, olefin type and styrene type thermoplastic elastomers are preferable, and a mixture of polypropylene and ethylene propylene rubber and a mixture of polypropylene and butyl rubber are particularly preferable .
[0008]
In the present invention, the thermoplastic resin is molded into an arbitrary shape composed of a combination of a plane and a curved surface having a substantially constant thickness, while the thermoplastic elastomer is cushioned on the back surface of the molded body made of the thermoplastic resin. The material is lined in the form of a planar foam or foam sheet having a substantially constant thickness. However, the foam of the present invention is not a crosslinked foam that is crosslinked at the same time as foaming, but needs to be a thermoplastic foam that foams without crosslinking and maintains its thermoplasticity.
[0009]
Therefore, it is necessary to set the foaming conditions for the thermoplastic elastomer of the present invention so that crosslinking does not occur during foaming. As a means for that, as described above, the above-mentioned dynamic crosslinking is performed at the time of production, and a thermal decomposition type foaming agent is used, and a sheet is formed by kneading at a low temperature at which the decomposition does not occur. As described above, foaming is performed by heating above the decomposition temperature, non-decomposable foaming agents such as water, inert gas, microsphere foaming agents, etc. are used, and a thermoplastic elastomer having a high melt viscosity is selected. For example, the temperature during foaming is set low, or the blending amount of the foaming agent is set small.
[0010]
The planar laminated molded body of the present invention is formed by molding the skin layer and the cushion layer by means of two-color molding, co-extrusion molding or integral molding of the thermoplastic resin and the thermoplastic elastomer, and simultaneously forming both at the interface. In this case, the thermoplastic resin or thermoplastic elastomer itself becomes the bonding means, but the outer layer is formed into a desired shape by the thermoplastic resin alone, while the thermoplastic resin is molded. elastomer made a foamed sheet, the foamed sheet may be bonded to the thus stacked state e Ttomeruto adhesive to the back surface of the skin layer.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
Using polypropylene as the resin component and ethylene propylene rubber as the rubber component, the above resin component and rubber component were weighed to a weight ratio of 90/10 to 10/90 and charged into a kneader. Appropriate compounding agents are added to 100 parts by weight, for example, 0 to 50 parts by weight of process oil, 0.05 to 5 parts by weight of organic peroxide, 0 to 10 parts by weight of crosslinking aid, and others. The rubber component is kneaded at a temperature of 150 to 220 ° C. for 0.5 to 10 minutes, and the rubber component is dynamically vulcanized to obtain a polypropylene-based thermoplastic elastomer composition.
[0012]
The obtained thermoplastic elastomer composition is melted at a temperature of 150 to 190 ° C., and 0.1 to 10 parts by weight of a pyrolytic foaming agent having a decomposition temperature of 160 to 220 ° C. is added to 100 parts by weight of the composition and kneaded. Subsequently, it is molded into a sheet at a temperature of 150 to 210 ° C. and foamed at the same time to obtain a foamed sheet having a thickness of 0.5 to 5 mm. The obtained foamed sheet is laminated on the back surface of a sheet-like molded body formed beforehand with a polypropylene sheet having a thickness of 0.05 to 2.0 mm via a sheet-like hot melt adhesive made of a polyethylene / vinyl acetate copolymer. A planar laminated molded body having pressure-bonded at a temperature of 100 to 150 ° C., having a planar molded body made of polypropylene as a skin layer, and a thermoplastic foamed sheet of polypropylene thermoplastic elastomer using EPDM as a rubber component as a cushion layer. obtain.
[0013]
Embodiment 2
In the first embodiment, when producing the thermoplastic elastomer composition, butyl rubber is used in place of ethylene propylene rubber, and other than that, polypropylene is used as a skin layer in the same manner as in the first embodiment, and polypropylene using butyl rubber as a rubber component. A planar laminated molded body having a thermoplastic foamed sheet of a thermoplastic elastomer as a cushion layer is obtained.
[0015]
Embodiment 3
Two extruders are connected via a die, polypropylene for the skin layer is extruded with one extruder, and the polypropylene-based thermoplastic elastomer for the cushion layer containing the foaming agent of Embodiment 1 is used with the other extruder. The composition is extruded to obtain a planar laminated molded body having a skin layer made of polypropylene and a thermoplastic foamed sheet of polypropylene-based thermoplastic elastomer as cushion layers.
[0017]
【Example】
Example 1
Polypropylene PP (Grand Polypro F327D manufactured by Grand Holmer) was used to form a sheet having a thickness of 2 mm, and this was used as the skin layer. Also, 30 parts of the above polypropylene, 70 parts of EPDM (“EP57P” manufactured by JSR) and 30 parts of process oil (“Diana Process Oil PW9D” manufactured by Idemitsu Kosan Co., Ltd.) are kneaded and subjected to dynamic crosslinking to form a completely crosslinked type. A polypropylene-based thermoplastic elastomer (TPO-A) was produced.
[0018]
After dry blending 5 parts of foaming agent A (Azodicarbonamide thermal decomposition type foaming agent “Vinole AC # 3”, decomposition temperature 208 ° C., manufactured by Eiwa Kasei Kogyo Co., Ltd.) to 100 parts of the obtained polypropylene-based thermoplastic elastomer Using a single screw extruder (Plastics Engineering Laboratory, 40mm diameter), molded and foamed at a temperature of 180-220 ° C, 3mm thick thermoplastic foam sheet (density: 0.60g / ml, Hs: 60C) Got.
[0019]
As a joining means for laminating the above thermoplastic foam sheet on the back surface of the polypropylene skin layer, a thickness of 0.05 made of polyethylene ("Evertate K2010" manufactured by Sumitomo Chemical Co., Ltd.) copolymerized with 20% by weight of vinyl acetate monomer mm hot melt sheet HM is prepared, and the above thermoplastic foam sheet is pressure-bonded to the back surface of the polypropylene skin layer at 130 ° C. through the hot melt sheet HM, and a 2 mm thick polypropylene sheet is used as the skin layer. Thus, a planar laminated molded body of Example 1 having a 3 mm thick thermoplastic foam sheet as a cushion layer was obtained.
[0020]
Example 2
Example except that foaming agent B (Microsphere type foaming agent “Expansel 093-120” manufactured by Nippon Philite Co., Ltd.) was used in place of the foaming agent A of Example 1 and the addition amount was 0.5 parts. In the same manner as in Example 1, a planar laminated molded body of Example 2 was obtained.
[0023]
Comparative Example 1
Instead of the thermoplastic foamed sheet made of the polypropylene-based thermoplastic elastomer constituting the cushion layer of Example 1, a polyethylene foam PEF having a thickness of 3 mm obtained by crosslinking and foaming a polyethylene sheet with an electron beam (manufactured by Toray Industries, Inc.) A 2 mm thick polypropylene sheet was used in the same manner as in Example 1 except that the adhesive sheet NE made of a synthetic rubber adhesive (“Thermal Adhesive Tape M5250” manufactured by Nitto Denko Corporation) was used as a joining means. A planar laminated molded body of Comparative Example 1 was obtained which had a 3 mm thick crosslinked foamed sheet made of polyethylene foam as a skin layer and a cushion layer.
[0024]
Comparative Example 2
In place of the adhesive sheet NE (joining means) of Comparative Example 1 above, the snap button-like polypropylene binding tool CP of Example 3 was used, and this was arranged in the same manner as in Example 3. A planar laminated molded body of Comparative Example 2 was obtained using a polypropylene sheet having a thickness of 2 mm as a skin layer and a crosslinked foamed sheet having a thickness of 3 mm made of polyethylene foam as a cushion layer.
[0025]
The planar laminated molded bodies of Examples 1 and 2 and Comparative Examples 1 and 2 were each pulverized by a pulverizer, the same amount of polypropylene was added to the obtained pulverized product, dry blended, and then the extrusion A sheet with a thickness of 0.5mm was formed by a machine, and the number of fish eyes on the surface, the number of gels , and the elongation retention (ratio between the elongation of the recycled sheet and the elongation of the polypropylene sheet of the skin layer) were compared. did. The results are shown in Table 1 together with the raw material composition of the original planar laminated molded body.
[0026]
[Table 1]

In Table 1, PE means polyethylene, HM means a hot melt sheet, CP means a snap button type PP binding tool, NE means an adhesive sheet, and FE means fish eye.
[0027]
Example 3
Two extruders are connected via a die, the polypropylene of Example 1 is supplied to one extruder, and the mixture of the polypropylene-based thermoplastic elastomer and foaming agent A of Example 1 is supplied to the other extruder. Other than the above, extrusion was performed in the same manner as in Example 1, and simultaneously with this extrusion, a polypropylene sheet having a thickness of 2 mm and a thermoplastic foam sheet having a thickness of 2 mm were directly laminated. The planar laminated molded body of Example 3 which uses a plastic foam sheet as a cushion layer was obtained. The obtained sheet laminate molded article had good adhesion between the skin layer and the cushion layer, and in the 180 degree peel test, the thermoplastic foam sheet of the cushion layer was broken.
[0029]
【The invention's effect】
As described above, the planar laminated molded body according to the present invention can be used as an interior part of automobiles, home electric appliances and other parts as in the case of conventional products, and has a gel point when remelted for recycling. Since no fish eyes are generated, a recycled product having a good appearance and less physical properties such as elongation can be obtained .

Claims (2)

Cushion layer on the rear surface of the skin layer of a thermoplastic resin composed of a thermoplastic foam of a thermoplastic elastomer which is a product layer by direct bonding, a thermoplastic elastomer in which the skin layer is a polypropylene resin, constituting the cushion layer There planar molded laminate according to claim Rukoto such subjected to dynamic crosslinking to a mixture of polypropylene and ethylene-propylene rubber or butyl rubber. The planar laminated molded article according to claim 1, wherein the skin layer and the cushion layer are bonded via a hot melt adhesive having compatibility therewith .