JP2905037B2 - Laminated sheet for automotive interior materials suitable for thermoforming - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle interior material for securing heat insulation, sound absorption and sound insulation, safety, and the like.
In particular, the present invention relates to automotive interior materials such as ceiling materials and rear shelves.

[0002]

2. Description of the Related Art As a conventional automobile interior member,
A molded article formed by bonding a film of a styrene-maleic anhydride copolymer to both sides of a foamed sheet of a styrene-maleic anhydride copolymer and molding it into a predetermined shape, and further laminating a surface covering material such as a urethane foam to the molded article Are widely used for automobile ceiling materials and the like. Such automotive interior parts according to the prior art are characterized by being lightweight and having a high heat insulating effect, but on the other hand, they use a copolymer of styrene-maleic anhydride as a resin, so they have a high heat resistance when used as an automobile ceiling material. In particular, there was a risk that the roof would hang down or deform under its own weight due to a rise in the temperature of the roof during the daytime.

In Japanese Utility Model Laid-Open No. 4-1162,
Using a mixture of polyphenylene ether resin and polystyrene resin instead of styrene-maleic anhydride copolymer as the resin used for the foamed sheet, heat-press molding both sides of this foamed sheet to homogenous polyphenylene ether resin and polystyrene An automotive ceiling material is described which is formed by laminating a film of a mixture with a base resin into a predetermined shape. This automobile ceiling material is said to improve deformation and sagging due to a rise in temperature of the roof by using a modified polyphenylene ether resin having high heat resistance.

However, when laminating homogeneous films on both sides of a foam of a mixture of a polyphenylene ether resin and a polystyrene resin, the foaming agent escapes during and after lamination, thereby causing the film to escape. There is a problem that air pockets are easily generated between the layer and the foam layer, and this cannot be used as a ceiling material or the like. Further, when molded as an automobile interior material, the thickness of a ceiling material of an automobile or the like is generally not constant, and the thickness is particularly small around a through hole. In addition, when attaching an accessory to a ceiling material, the thickness of this part is thin, and a high-precision one is required. The reality is that nothing in line with such a request has yet been revealed.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned drawbacks, and as a result, have found that a mixed resin foam of a polyphenylene resin and a polystyrene resin is obtained. The inventors have found out that the problem can be solved by making the thickness, residual foaming agent, and open cell ratio specific, and have completed the present invention. That is, the present invention relates to a mixture of 10 to 60% by weight of a polyphenylene ether resin and 90 to 40% by weight of a polystyrene-based resin, or a polyphenylene ether-based copolymer obtained by graft copolymerizing a styrene-based monomer to a polyphenylene ether resin and a polystyrene-based copolymer. In a mixture with a resin, a mixture in which the phenylene ether resin component accounts for 10 to 60% by weight and the polystyrene-based resin component accounts for 90 to 40% by weight in the mixture is used as a base resin,
A foaming agent was added to the base resin and the mixture was extruded and foamed. The thickness was 2 to 6 mm, the expansion ratio was 5 to 20 times, and the open cell ratio was 5 to 25.
%, A foamed sheet having a residual foaming agent amount of 0.8 to 3.0% by weight, a mixture of 10 to 70% by weight of a polyphenylene ether resin and 90 to 30% by weight of a polystyrene resin, or a polyphenylene ether resin. A mixture of a polyphenylene ether copolymer obtained by graft copolymerizing a styrene monomer and a polystyrene resin, wherein the phenylene ether resin component accounts for 10 to 70% by weight of the mixture and the polystyrene resin accounts for 90 to 30% by weight. A laminated sheet for automotive interior materials suitable for thermoforming, characterized by laminating a resin film composed of a mixture as described above.

Hereinafter, the present invention will be described in more detail. The foam sheet in the present invention is made of polyphenylene ether resin 10
Or a mixture of polystyrene-based resin and polyphenylene ether-based copolymer obtained by graft copolymerization of styrene-based monomer with polyphenylene ether-based resin and polystyrene-based resin. The phenylene ether resin component accounts for 10 to 6
0% by weight, 90-40% by weight of polystyrene resin component
Is used as the base resin. The polyphenylene ether resin referred to in the present invention refers to a resin represented by the following general formula 1.

Embedded image (Here, R1 and R2 represent an alkyl group having 1 to 4 carbon atoms or a halogen atom, and n represents the degree of polymerization.)
Specific examples of polyphenylene ether include poly (2,6-dimethylphenylene-1,4-ether),
Poly (2,6-diphenylphenylene-1,4-ether), poly (2,6-dichlorophenylene-1,4-ether), poly (2,6-dibromophenylene-1,4)
Poly (2-methyl-6-ethylphenylene-1,4-ether), poly (2-chloro-6-methylphenylene-1,4-ether), poly (2-methyl-6-isopropylphenylene-1,4-ether),
Poly (2,6-di-n-propylphenylene-1,4-ether), poly (2-blemu 6-methylphenylene-1,4-ether), poly (2-chloro-6-bromophenylene-1,4-ether), poly (2 -Chlorou-6-ethylphenylene-1,4-ether) and the like.
Those having a polymerization degree n in the range of usually 10 to 5000 can be used.

In the present invention, the styrene monomer for graft polymerization to the polyphenylene ether includes a styrene monomer, a derivative such as alkylation or halogenation of styrene, and specific examples thereof include styrene and α-methylstyrene. 2,4-dimethylstyrene, monochlorostyrene, dichlorostyrene, P-methylstyrene,
P-tert-butylstyrene, ethylstyrene and the like.

[0008] The polyphenylene ether copolymer in the present invention refers to a copolymer obtained by graft copolymerizing the styrene monomer with the polyphenylene ether resin.

In the present invention, a polystyrene resin mainly mixed with a polyphenylene ether copolymer refers to a homopolymer of the styrene monomer or a vinyl compound copolymerizable at the time of polymerization, for example, methyl methacrylate, acrylonitrile, methacryloyl. Copolymers such as nitrile and butyl acrylate may be used, or these may be used in combination.

Also, a high impact polystyrene resin, a styrene butadiene copolymer,
A styrene butadiene-styrene block copolymer or the like can be used in combination.

The foamed sheet of the present invention comprises 10 to 60% by weight of polyphenylene ether resin and 90% of polystyrene resin.
-40% by weight or a mixture of a polyphenylene ether copolymer obtained by graft copolymerizing a styrene monomer with a polyphenylene ether resin and a polystyrene resin, wherein the phenylene ether resin component in the mixture is 10%. ~ 60% by weight, polystyrene resin component is 9
A mixture of 0 to 40% by weight is used as a base resin, and a foaming agent is added to the mixture to perform extrusion foaming. When the phenylene ether resin component contained in the foamed sheet of the present invention is less than 10% by weight, sufficient heat resistance for use as an automobile interior material cannot be obtained, and when the phenylene ether resin component is more than 60% by weight, extrusion does not occur. This is because the foaming property deteriorates and a good foam sheet cannot be obtained, which is not preferable.

The foamed sheet of the present invention has a thickness of 2 to 6
mm, the expansion ratio is 5 to 20 times, the open cell ratio is 5 to 25%, and the contained residual foaming agent must be 0.8 to 3.0% by weight.

In the present invention, the open cell ratio of the foamed sheet is 5 to 2
The reason for setting it to 5% is to perform the molding with high precision when molding a part having a different thickness. By setting the open cell ratio of the foamed sheet to 5 to 25%, when the resin film is laminated and between the film layer and the foamed layer formed by the foaming agent after the lamination, the foaming agent that escapes from the foamed sheet is used. It is possible to prevent a phenomenon that an air pocket is generated. Further, the obtained molded article is extremely excellent in strength, heat insulating property and sound insulating property. Extruded foamed sheets having an open cell ratio of more than 25% are not preferred because they have low stiffness and have a low secondary foaming rate even when heated in a heating furnace, and therefore have poor moldability. An extruded foamed sheet having an open cell ratio of less than 5%, that is, a sheet having a high closed cell ratio, cannot sufficiently perform molding with a different thickness at the time of molding, and the thickness accuracy is deteriorated. Further, air bubbles are generated between the film layer and the foam layer by the foaming agent when and after laminating the resin films, which is not preferable.

The amount of the foaming agent contained in the foamed sheet is 0.8 to
The reason why the amount is controlled within the range of 3.0% by weight is to prevent a phenomenon that air pockets are generated between the film layer and the foam layer due to the foaming agent when the resin film is laminated and after the lamination, and This is because the amount of the foaming agent remaining in the interior material of the automobile after the thermoforming is reduced, and the heat resistance and the dimensional stability over time are improved. In order to reduce the amount of the remaining foaming agent and prevent the phenomenon that the air pockets are generated, and to sufficiently and sufficiently perform secondary foaming, the amount of the foaming agent remaining in the foamed sheet is 0.8 to 0.8%.
It must be in the range of 3.0% by weight. A foamed sheet containing less than 0.8% by weight of the residual foaming agent has too low a secondary foaming rate and cannot be molded well. When a foamed sheet containing more than 3.0% by weight of the residual foaming agent is used, when the resin film is laminated and after the lamination, a phenomenon that air pockets are generated between the film layer and the foamed layer by the foaming agent due to the foaming agent. It is not preferable because it easily occurs and heat resistance and dimensional stability over time deteriorate.

The thickness of the foam sheet of the present invention is 2 to 6 mm.
It is necessary to be. It is thermoformed after secondary foaming by heating, but if the thickness is less than 2 mm, even if it is secondary foamed and molded, it will not be thin and will not be excellent in strength, heat insulation, sound insulation, and thickness. If the thickness is larger than 6 mm, it is difficult to obtain a foam having a low open cell ratio, and the moldability is significantly deteriorated.

Further, the expansion ratio of the foam sheet in the present invention needs to be 5 to 20 times, and preferably the expansion ratio is 7 to 15 times. If the expansion ratio is lower than 5 times, sufficient heat insulation and sound insulation cannot be exhibited, and a light-weight product cannot be obtained. If the ratio exceeds 20 times, sufficient strength and good moldability cannot be obtained, which is not preferable as an extruded foam sheet.

These foamed sheets can be obtained by subjecting the resin to foam molding using an extruder. For example, a resin mixed to be 10 to 60% by weight of a polyphenylene ether resin and 90 to 40% by weight of a polystyrene-based resin is put into an extruder and mixed under heating, and at the same time, a foaming agent is pressed in from the middle of the extruder. After mixing, extruding into a low-pressure area to form a foam, or after adjusting the foaming agent to the base resin in advance to form a foamable mixture, put into an extruder, mix under heating and extrude into the low-pressure area to foam A body-forming method is preferably used.

As the foaming agent used for obtaining the foamed sheet of the present invention, a volatile foaming agent is preferable. In particular, a KB value indicating the solubility of a foaming agent such as ethane, propane, butane, pentane or the like is 20 or more, and 50 or more. The following are preferred. Further, those having a KB value higher than the above range and those having a lower KB value may be suitably used by appropriately mixing two or more kinds. This is because if a foaming agent having a high solubility is used, it is difficult to obtain an extruded foam sheet having a residual foaming agent amount of 0.8 to 3.0% by weight. Further, when a foaming agent having a low solubility is used, a foam having a high open cell ratio is likely to be obtained.

At the time of extrusion foaming, an inorganic fine powder such as talc, a metal salt of a fatty acid such as a metal salt of stearic acid, a flame retardant, a lubricant and the like can be used as needed as a cell regulator.

The resin film laminated on both sides of the foamed sheet of the present invention obtained as described above is composed of 10 to 70% by weight of polyphenylene ether resin and 90 to 90% of polystyrene resin.
30% by weight or a mixture of a polyphenylene ether copolymer obtained by graft copolymerization of a styrene monomer with a polyphenylene ether resin and a polystyrene resin, wherein the phenylene ether resin component in the mixture is 10 to 10% by weight. 70% by weight, 90-3 polystyrene resin
A resin consisting of a mixture which is 0% by weight is used. These resin films are laminated for improving rigidity, strength, dimensional stability and the like.

In order to improve the brittleness of the resin film, a high-impact polystyrene resin, a styrene-butadiene copolymer, a styrene-butadiene-styrene block copolymer is used as a rubber component with respect to 100 parts by weight of the resin. It is preferable to use 20 parts by weight or less of coalescing or the like. In particular, high impact polystyrene resin is mixed with polyphenylene ether resin to
The content is preferably 0 parts by weight or less, and if the content exceeds 20 parts by weight, the improvement in bending strength and rigidity is not so much seen, which is not preferable.

The resin film has a thickness of 0.1 to 0.5 m.
When the thickness is less than 0.1 mm, a sufficient improvement in strength is not seen, and when the thickness is more than 0.5 mm, the material becomes too heavy as an automobile interior material and the cost is increased, which is not preferable.

As a method of laminating the resin film,
A method of heat bonding is preferable, for example, a method of bonding a film formed in advance to a foamed sheet by a hot roll, a method of laminating immediately after extruding the film, a co-extrusion laminating method using a multilayer extrusion die, and the like can be adopted. In particular, a method of laminating immediately after extruding a film and bonding the extruded film by heat is preferable. Above all, a method in which extrusion foaming of a foamed sheet and extrusion of a film are performed in-line to perform lamination, or a co-extrusion lamination method is particularly preferable. In addition, since the laminated sheet bonded by heat does not use an adhesive, scraps such as scrap generated in a production process can be collected and processed as it is in the form of a laminated body to form a repellet. The collected pellets can be reused as a foam sheet or film.

Further, on the laminated sheet, a surface covering material used as a conventional automobile interior material, for example, a woven fabric, a nonwoven fabric, a cushion material, or the like can be laminated as necessary using an appropriate adhesive.

The laminated sheet obtained by laminating the resin film, the surface material and the like on a foamed sheet can be formed into an automobile interior material by thermoforming. In particular, when performing secondary foaming in a heating furnace and performing thermoforming, a method of performing thermoforming while controlling in a mold so as to be 50 to 90% of the maximum foaming thickness is preferable, and a complicated shape having a partially different thickness is preferred. Can be formed with high precision. In addition, after the secondary foaming is performed in advance, it is also possible to compress by 10 to 50% of the thickness of the secondary foam when performing thermoforming. Furthermore, since the extruded foamed sheet has an open cell ratio of 5 to 25%, the residual foaming agent during molding is further reduced, heat resistance is improved, and the dimensional change rate with time is 2/1.
A remarkable effect that it can be less than 000 can be exhibited. In addition, air pockets that are likely to be generated at the time of laminating the resin film and at the time of secondary foaming can be suppressed if they are fine, and the molding cycle can be shortened.

[0026]

The present invention will be described below in more detail with reference to examples.
The properties of the thermoformed product were measured and evaluated according to the following methods. The laminated sheet was aged at room temperature for 2 weeks, then heated and subjected to secondary foaming to compress and mold the sheet. (1) Dimensional stability After heating for 4 hours in an air thermostat at 80 ° C., the mixture was naturally cooled to room temperature, and dimensions in two directions, longitudinal and lateral, were evaluated by a dimensional change rate before and after heating. The evaluation criteria are as follows. ◎: Dimensional change rate of less than 1/1000 in both the vertical and horizontal directions 寸 法: Dimensional change rate of the larger one in the vertical and horizontal directions is 1 /
1000 or more and less than 2/1000 Δ: dimensional change rate of the larger one in the vertical and horizontal directions is 2 /
1000 or more and less than 3/1000 x: dimensional change rate of the larger one in the vertical and horizontal directions is 3 /
Thousands or more

(2) Maximum bending strength of a molded product Measured by a method according to JIS A-9511.

The thickness of the above-mentioned maximum secondary foam is as follows: a three-layer laminate in which no surface material is laminated is 100 mm × 100 mm ×
After cutting to a thickness, the sheet was heated in an air thermostat at 130 ° C. for 15 minutes, cooled naturally and cooled to room temperature, and the thickness was measured.

The open cell ratio, expansion ratio, residual foaming agent amount, and Vicat softening point were measured by the following methods. (Open cell ratio): Measured using an air pycnometer in accordance with ASTM D2856. On this occasion,
The measurement sample was cut into 3 cm in vertical and horizontal dimensions, and several of these were superimposed to have a height of about 4 cm, which was used as a test sample. (Expansion ratio): Calculated using the following equation. (Amount of residual foaming agent): Measured using Yanagimoto gas chromatograph G80. (Vicat softening point): Measured by a method according to JIS K7206.

Example 1 A mixture of a polyphenylene ether resin and a polystyrene resin (trade name: NORYL MX4752, manufactured by GE Plastics) and a polystyrene resin (trade name: Denkastyrol HRM-2, manufactured by Denki Kagaku) Mixing was performed so that the phenylene ether resin component was 25% by weight and the polystyrene resin component was 75% by weight. The Vicat softening point of this mixed resin was 131 ° C. To 100 parts by weight of the mixed resin, 0.8 part by weight of talc as an additive was added, and the mixture was stirred and mixed. Then, 3.8 parts by weight of a mixture having a mixing ratio of isobutane and normal butane of 35:65 was used as a foaming agent. To obtain a foam sheet by extrusion foam molding. The obtained foamed sheet had an expansion ratio of 14.3 times, an open cell ratio of 18.5%, and a residual foaming agent amount of 2.8 parts by weight. After standing at room temperature for 2 weeks, the residual foaming agent amount was 2.2 parts by weight. Department. Further, a mixture of polyphenylene ether resin and polystyrene resin (trade name: NORYL MX475)
2, GE Plastics), polystyrene resin (trade name: Denka Styrol HRM-2, manufactured by Denki Kagaku) and high impact polystyrene resin (trade name: Denka Styrol HI-E-4, manufactured by Denki Kagaku) The resin which was mixed and stirred and mixed so that the phenylene ether resin component was 25% by weight, the polystyrene resin component was 73.5% by weight, and the rubber component was 1.5% by weight was extruded into a film using an extruder, and the above foamed sheet was extruded. Immediately after foam molding, a three-layer laminated sheet was obtained by a method of laminating on both sides in-line. FIG. 1 shows a sectional view of the obtained laminated sheet. The rubber component content of the resin mixture for the film,
It was 1.5% by weight. In the obtained three-layer laminated sheet, the thickness of the foam layer was 2.67 mm, and the thickness of each of the film layers was 0.165 mm. The obtained three-layer laminated sheet was a good sheet without generating air pockets between the film layer and the foam layer. Table 1 shows the maximum secondary foam thickness and the properties of the thermoformed test product.

Example 2 A mixture of a polyphenylene ether resin and a polystyrene resin (trade name: NORYL MX4752, manufactured by GE Plastics) and a polystyrene resin (trade name: Denkastyrol HRM-2, manufactured by Denki Kagaku) An impact polystyrene resin (trade name: Denkastyrol HIE-4, manufactured by Denki Kagaku) was mixed, and a phenylene ether resin component 35% by weight and a polystyrene resin component 6 were mixed.
They were mixed so that 3.5% by weight and 1.5% by weight of the rubber component were obtained. The Vicat softening point of this mixed resin was 142 ° C. To 100 parts by weight of the mixed resin, 0.8 part by weight of talc as an additive was added, and the mixture was stirred and mixed. Then, 3.8 parts by weight of a mixture having a mixing ratio of isobutane and normal butane of 35:65 was used as a foaming agent. To obtain a foam sheet by extrusion foam molding. The obtained foam sheet has an expansion ratio of 1.
4.3 times, open cell ratio 18.8%, residual foaming agent amount 2.7
Parts by weight, and the amount of the residual foaming agent after standing at room temperature for 2 weeks was 2.1 parts by weight. Further, a mixture of polyphenylene ether resin and polystyrene resin (trade name: NOR)
YL MX4752, manufactured by GE Plastics Co., Ltd.) and a high impact polystyrene resin (trade name: Stylon 495, manufactured by Asahi Kasei Co., Ltd.), 40% by weight of a phenylene ether resin component, 55.5% by weight of a polystyrene resin component, and a rubber component 4. The resin mixed and stirred at 5% by weight was extruded into a film using an extruder, and immediately after the foamed sheet was extruded and foamed, three layers of laminated sheets were obtained by in-line lamination on both sides. The rubber component content of the resin mixture for a film was 1.5% by weight. The obtained three-layer laminated sheet had a foam layer thickness of 2.67 mm and a film layer of 0.165 mm each.
Met. The resulting three-layer laminated sheet was a good sheet without air pockets between the film layer and the foam layer. Table 1 shows the maximum secondary foam thickness and the properties of the thermoformed test product.

Comparative Example 1 A mixture of a polyphenylene ether resin and a polystyrene resin (trade name: NORYL MX4752, manufactured by GE Plastics) and a polystyrene resin (trade name: Denkastyrol HRM-2, manufactured by Denki Kagaku) Mixing was performed so that the phenylene ether resin component was 25% by weight and the polystyrene resin component was 75% by weight. The Vicat softening point of this mixed resin was 131 ° C. 0.8 parts by weight of talc as an additive is added to 100 parts by weight of the mixed resin, and after stirring and mixing, 5.5 parts by weight of a mixture in which a mixing ratio of isobutane and normal butane is 35:65 is used as a foaming agent. To obtain a foam sheet by extrusion foam molding. The obtained foamed sheet had an expansion ratio of 14.3 times, an open cell ratio of 44.5%, and a residual foaming agent amount of 2.0 parts by weight. After leaving at room temperature for 2 weeks, the residual foaming agent amount was 0.7 wt. Department. Further, a mixture of polyphenylene ether resin and polystyrene resin (trade name: NORYL MX475)
2, GE Plastics), polystyrene resin (trade name: Denka Styrol HRM-2, manufactured by Denki Kagaku) and high impact polystyrene resin (trade name: Denka Styrol HI-E-4, manufactured by Denki Kagaku) The resin which was mixed and stirred and mixed so that the phenylene ether resin component was 25% by weight, the polystyrene resin component was 73.5% by weight, and the rubber component was 1.5% by weight was extruded into a film using an extruder, and the above foamed sheet was extruded. Immediately after foam molding, a three-layer laminated sheet was obtained by a method of laminating on both sides in-line. The rubber component content of the resin mixture for a film was 1.5% by weight. In the obtained three-layer laminated sheet, the thickness of the foam layer was 2.67 mm, and the thickness of each of the film layers was 0.165 mm. Table 1 shows the thickness of the secondary foam and physical properties of the thermoformed test product of the obtained three-layer laminated sheet.

Comparative Example 2 A mixture of a polyphenylene ether resin and a polystyrene resin (trade name: NORYL MX4752, manufactured by GE Plastics) and a polystyrene resin (trade name: Denkastyrol HRM-2, manufactured by Denki Kagaku) Mixing was performed so that the phenylene ether resin component was 25% by weight and the polystyrene resin component was 75% by weight. The Vicat softening point of this mixed resin was 131 ° C. To 100 parts by weight of the mixed resin, 0.8 part by weight of talc as an additive was added and stirred and mixed. Then, 6.0 parts by weight of a mixture having a mixing ratio of isobutane and normal butane of 35:65 was used as a foaming agent. To obtain a foam sheet by extrusion foam molding. The obtained foamed sheet had a foaming ratio of 14.3 times, an open cell ratio of 13.5%, and a residual foaming agent amount of 3.9 parts by weight. After leaving at room temperature for 2 weeks, the residual foaming agent amount was 3.5 parts by weight. Department. Further, a mixture of polyphenylene ether resin and polystyrene resin (trade name: NORYL MX475)
2, GE Plastics), polystyrene resin (trade name: Denka Styrol HRM-2, manufactured by Denki Kagaku) and high impact polystyrene resin (trade name: Denka Styrol HI-E-4, manufactured by Denki Kagaku) The resin which was mixed and stirred and mixed so that the phenylene ether resin component was 25% by weight, the polystyrene resin component was 73.5% by weight, and the rubber component was 1.5% by weight was extruded into a film using an extruder, and the above foamed sheet was extruded. Immediately after foam molding, a three-layer laminated sheet was obtained by a method of laminating on both sides in-line. The rubber component content of the resin mixture for a film was 1.5% by weight. In the obtained three-layer laminated sheet, the thickness of the foam layer was 2.77 mm, and each of the film layers was 0.165 mm. In the obtained three-layer laminated sheet, several air pockets were generated between the film layer and the foam layer. Table 1 shows the maximum secondary foam thickness and the properties of the thermoformed test product.

Examples 3 and 4 Each of the laminated sheets obtained in Examples 1 and 2 was subjected to extrusion molding for two weeks, and then a nonwoven fabric was laminated as a surface material using a hot-melt type adhesive. The automobile ceiling material shown in FIG. 3 was formed. As a result of the molding, the obtained car ceiling material did not have any air pockets between the film layer and the foam layer, and the room mirror mounting hole 4, the sun visor mounting hole 5, the mounting hole 6, the interior light mounting hole 7 The periphery of the car was thin and precisely molded, and was a good automotive ceiling material. Also, the step forming portion provided around the interior light mounting hole 7 was formed sharply and had a good appearance.

Comparative Examples 3 and 4 Each of the laminated sheets obtained in Comparative Examples 1 and 2 was laminated with a nonwoven fabric as a surface material using a hot-melt type adhesive two weeks after extrusion molding. The automobile ceiling material shown in FIG. 3 was formed. As a result of molding, in the automotive ceiling material using the laminated sheet of Comparative Example 1, the shape of the step molding portion provided around the interior light mounting hole 7 was not clear, and in particular, the room mirror mounting hole 4, the sun visor mounting hole 5, The periphery of the mounting hole 6 and the interior light mounting hole 7 could not be precisely formed. In addition, the overall thickness was too small to be used as an automobile ceiling material. Also, in the automotive ceiling material using the laminated sheet of Comparative Example 2, several large air pockets were formed between the film layer and the foam layer by thermoforming, and large air pockets were partially generated.
Even if the periphery of the rear-view mirror mounting hole 4, the sun visor mounting hole 5, the mounting hole 6, and the interior light mounting hole 7 are thinly formed, the thickness naturally recovers after the formation and lacks precision. Became unusable.

[0036]

[Table 1]

[0037]

The laminated sheet for automobile interior materials according to the present invention has a specific thickness of 2 to 6 mm, a specific expansion ratio of 5 to 20 times, a specific low open cell ratio of 5 to 25%, A foam sheet having a residual foaming agent amount as low as 0.8 to 3.0% by weight, and a resin film laminated on both sides of the foam sheet, thereby forming portions having different thicknesses and further a perforated portion therein. It is possible to obtain a laminated sheet for an automobile interior material in which an automobile interior material can be suitably thermoformed. Further, it is possible to prevent a phenomenon that air is trapped between the film layer and the foamed layer, which is likely to occur when laminating a film on an extruded foamed sheet and after laminating.

Further, since the amount of the remaining foaming agent in the foamed sheet is as small as 0.8 to 3.0% by weight, after thermoforming, it is further reduced to obtain an automobile interior material excellent in heat resistance and dimensional stability. Can be. In particular, the dimensional change rate over time is 2 /
A remarkable effect of less than 1,000 can be exhibited.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a laminated sheet for an automobile interior material according to the present invention.

FIG. 2 is a plan view of an automobile ceiling material formed in Examples 3 and 4 and Comparative Examples 3 and 4. The molded bodies that can be used as automobile ceiling materials include the room mirror mounting hole 4, the sun visor mounting hole 5, the mounting hole 6, and the interior light mounting hole 7 in the figure.
Is required to be thin and precisely formed, and that the step forming portion around the interior light mounting hole be precisely formed.

FIG. 3 is a perspective sectional view of an automobile ceiling material formed in Examples 3 and 4 and Comparative Examples 3 and 4.

[Explanation of symbols]

 1. Film layer 2. Foam sheet 3. Automotive ceiling materials 4. Room mirror mounting hole 5. Sun visor mounting hole 6. Mounting hole 7. 7. Interior light mounting hole Step formation around the interior light mounting hole

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 5/18 B32B 27/30 B60R 13/02

Claims (1)

(57) [Claims] 1. A mixture of 10 to 60% by weight of a polyphenylene ether resin and 90 to 40% by weight of a polystyrene resin, or a polyphenylene ether copolymer obtained by graft copolymerizing a styrene monomer to a polyphenylene ether resin and a polystyrene resin. And a mixture comprising 10 to 60% by weight of a phenylene ether resin component and 90 to 40% by weight of a polystyrene-based resin component in the mixture. 2-6 mm in thickness, foaming ratio 5-2 obtained by extrusion foaming
0 times, open cell ratio 5-25%, residual foaming agent amount 0.8-
A mixture of 10 to 70% by weight of a polyphenylene ether resin and 90 to 30% by weight of a polystyrene-based resin or a polyphenylene ether obtained by graft-copolymerizing a styrene-based monomer to a polyphenylene ether resin on both sides of a foamed sheet of 3.0% by weight. A mixture of a styrene copolymer and a polystyrene resin, wherein the phenylene ether resin component accounts for 10 to 70% by weight of the mixture and the polystyrene resin accounts for 9%.
A laminated sheet for automotive interior materials suitable for thermoforming, characterized in that a resin film composed of a mixture of 0 to 30% by weight is laminated.