JPH0768721A - Bonding film for automotive interior finish material, and automotive interior finish material - Google Patents

Abstract

PURPOSE:To improve the efficiency of bonding a skin material and a base material together, to rationalize a bonding operation and to provide excellent air shut-off performance and function. CONSTITUTION:An interior finish material bonding film 1A (1B) for an automobile comprises an outer layer 10a (10b) and an inner layer 12 made of polyethylene resin, and an intermediate layer 11 made of synthetic resin having a melting point higher by 30 deg.C or more than that of the polyethylene resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film used for laminating a base material for an automobile interior material and a cosmetic skin material such as a nonwoven fabric, and an automobile interior material using the film. is there.

[0002]

2. Description of the Related Art Conventionally, as an interior material (interior ceiling material) applied to an interior of an automobile, for example, an interior base material having various functions such as heat resistance, heat insulation, rigidity, sound absorption, moldability, and the like,
There is used a material formed by laminating an interior skin material having excellent moldability, abrasion resistance, aesthetics, texture, etc. and breathability.

For bonding the base material and the skin material, there is a step of applying an adhesive containing an organic solvent, a step of applying a hot melt adhesive capable of adhering in a short time, and a heat-sensitive adhesive property. A method including any step such as a step of heating and pressure bonding through a film is often used. However, particularly in the above two steps, there are cases where the shaping of the base material by press molding and the skin adhesion cannot be performed at the same time. For this reason, at least three steps are required: a step of forming the base material by press molding first, a step of applying an adhesive agent to the base material and a step of sticking a skin to the base material, following the above steps.

Further, when the base material used is a material which does not have an air blocking function, PVC or PBT which is expected only to have an air blocking function is provided for the purpose of imparting the air blocking function to this base material. A method of attaching a film such as the above to the back surface of the skin material, the surface of the base material, the intermediate layer of the base material, or the back surface of the base material with an adhesive, a thermoplastic resin, or the like is often used.

If the base material does not have a sufficient air blocking function, the following problems may occur.
That is, for example, when a vehicle is running, the pressure difference between the interior of the interior material and the exterior of the interior material, such as dust, cigarette smoke, causes contamination of the interior of the vehicle interior due to the pressure difference. Air may pass through the skin material and the base material and flow to the back side of the interior material, or conversely, contaminated air outside the passenger compartment may flow into the passenger compartment. For this reason, the pollutants sometimes come into contact with and adhere to the surface of the skin material and become easily soiled.

[0006]

[Problems to be Solved by the Invention]

(1) In the case of producing an automobile interior material, when the air-permeable interior skin material and the base material are heat-pressed with a heat-sensitive adhesive film together with a heat-sensitive adhesive film interposed therebetween, the heat-sensitive material is used. Since the adhesive film melts, a part of the melt penetrates into the base material side, or is stretched and torn off, the resin layer forming the heat-sensitive adhesive film easily collapses, and It is difficult to obtain a stable air blocking function. (2) In addition, in the case of manufacturing an automobile interior material that usually has a complicated shape, in order to improve productivity, the three steps are
In order to reduce the number of steps, the step of attaching the heat-sensitive adhesive film to the interior skin material is followed by two steps, namely, the step of attaching the surface of the heat-sensitive adhesive film and the interior base material. The step of forming into the shape of the interior material can be performed at the same time.

In this case, however, in the step of bonding the heat-sensitive adhesive film to the skin material, when both are pressure-bonded with a heat roll, the heat-sensitive adhesive film is melted to prevent the air-blocking property from being deteriorated. If the heat quantity is suppressed, adhesion failure due to insufficient heat quantity tends to occur, and conversely, if heat quantity is given to solve the adhesion failure, the air blocking function as an automobile interior material is impaired and the heat-sensitive adhesive film heats the heat roll. The problem of sticking to the pressure-bonded surface and remarkably lowering workability and processing efficiency was likely to occur. (3) Also, when the epidermis is adhered with a hot melt adhesive or the like, the adhesiveness is very likely to change due to changes in the coating amount, atmosphere temperature and temperature, etc., and it is very complicated and expensive to try to control them appropriately. It is not economical because it requires various facilities. Moreover, since the reaction time of the adhesive is relatively long, high moldability of the skin is highly required, and if it is not satisfied, there is a problem that adhesion failure of the skin material is very likely to occur.

The present invention solves the above problems, improves the efficiency of laminating a skin material and a base material and rationalizes the laminating work, and also laminates an automobile interior material having an excellent air barrier property and function. An object is to provide a film for automobiles and an automobile interior material.

[0009]

Means for Solving the Problems The present inventor uses a polyethylene-based resin whose melting point and melt index are appropriately different from each other as an outer layer and an inner layer of a film, and thus, it is possible to obtain good quality when heat-pressing with a skin material for automobile interior. Adhesiveness and good adhesiveness at the time of thermocompression molding with a base material are obtained, and by using a synthetic resin having a melting point higher than that of each of the polyethylene-based resins as the intermediate layer, the obtained interior material is air-bonded. The inventors have found that they have excellent barrier properties and have made the following inventions. (1) The film for laminating an automobile interior material according to the first invention is characterized in that the outer layer and the inner layer are made of a polyethylene resin, and the intermediate layer is made of a synthetic resin having a melting point higher by 30 ° C. or more than the polyethylene resin. .

Preferred modes 1 to 3 of the first invention are shown below. That is, in aspect 1, in the first invention, the outer layer has a melt index of 5.0 to 30.0 g / 10 m.
in, melt index is 5.0g / 10mi in the inner layer
A polyethylene resin of less than n is used. Aspect 2 is characterized in that in the above aspect 1, the melting point of the polyethylene-based resin used for the inner layer is 10 ° C. or more higher than the melting point of the polyethylene-based resin used for the outer layer.

Aspect 3 is characterized in that, in the above Aspects 1 and 2, the synthetic resin of the intermediate layer is nylon or ethylene-vinyl alcohol copolymer resin. (2) In the automobile interior material of the second invention, the outer layer and the inner layer are made of polyethylene resin, and the intermediate layer is made of a synthetic resin having a melting point of 30 ° C. or more higher than that of the polyethylene resin. The material and the base material are bonded together.

The laminating film (hereinafter, referred to as a film) of the first invention and the second invention is an outer layer, an intermediate layer,
It is composed of three layers including an inner layer, and the outer layer is used by being adhered to the skin material of the interior material, and the inner layer is being used by being adhered to the base material of the interior material. Outer layer, intermediate layer, which constitutes the film,
Terms such as the inner layer do not indicate the position at the time of film production, but the outer layer represents the film surface in contact with the skin material, and the inner layer represents the film surface in contact with the base material.

The polyethylene resin used for the outer layer and the inner layer is not particularly limited as long as it is a resin having heat-sensitive adhesive property. For example, not only low density polyethylene, linear low density polyethylene and high density polyethylene, Ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin, ethylene-acrylic acid copolymer resin, ethylene-methyl acrylate copolymer resin, ethylene-methyl methacrylate copolymer resin, ethylene-methacrylic acid copolymer resin and blends thereof. Things can be mentioned.

In particular, the outer layer has a melt index (hereinafter referred to as MI) of 5.0 to 30.0 g / 10 mi.
It is preferable to use polyethylene resin of n and polyethylene resin having MI of less than 5.0 g / 10 min for the inner layer. In this case, as compared with the heat fluidity of the outer layer in the portion in contact with the skin material, the heat fluidity of the inner layer in the portion in contact with the base material is low, so that the resin of the inner layer is melted on the thermocompression bonding roll or the heating plate at the time of bonding. It is possible to reduce adhesion and adhesion, and improve workability and production efficiency. Moreover,
An automobile interior material having a stable adhesive force and a stable air blocking function can be obtained.

For these reasons, it is most preferable that the polyethylene resin used for the inner layer has a melting point higher than that of the polyethylene resin forming the outer layer by 10 ° C. or more. The synthetic resin used for the intermediate layer is not particularly limited as long as it is a synthetic resin having a melting point of 30 ° C. or more higher than that of the polyethylene resin used for the outer layer and the inner layer. It is particularly preferable to use a nylon or ethylene-vinyl alcohol copolymer which is also excellent in adhesiveness.

The film is formed by an inflation molding method, T
Can be manufactured by any of the die-cast molding methods,
The thickness is preferably 40 to 120 μm. The intermediate layer preferably has a thickness of 5 to 50 μm, and particularly 1
Most preferably, the thickness is 0 to 30 μm. If the thickness of the intermediate layer is less than 5 μm, the intermediate layer may be locally stretched at the time of laminating and forming a hole and the air blocking function may be impaired. This results in problems such as high cost, uneconomical, and a large amount of heat required at the time of molding to deteriorate moldability.

The film can be bonded to various skin materials and substrates described below, or can be bonded and molded at the same time. That is, the film can be attached to one surface with high efficiency by using a heating roll or the like as a skin material such as polyester-based nonwoven fabric, raised knit, PVC leather, TPO leather, or the like.

Further, the film is obtained by laminating the skin material on one surface and subjecting the other surface to, for example, needle punching as a base material on at least one surface of the mat-like material containing inorganic fibers as a main component. One having a thermoplastic resin film such as polyethylene, one impregnated with a thermoplastic resin on at least one side, or one having a thermoplastic resin containing a foaming material on at least one side,
Alternatively, one having at least one surface thereof an inorganic fiber or a thermoplastic resin mixed with a filler, or a mat having an inorganic fiber as a main component instead of the mat-like substance having the inorganic fiber as a main component in the same base material. A material impregnated with an emulsion type adhesive, a foaming agent or a thermoplastic resin, or a material having a resin foam such as urethane having a film layer mainly composed of a thermoplastic resin on at least one side as a core material,
Further, a felt or a mat-like material mainly composed of an inorganic fiber impregnated with at least one kind of thermosetting resin or thermoplastic resin or a foaming agent is heat-pressed together with the skin material after being bonded to the one surface. It is possible to manufacture and provide an automobile interior material having an excellent air-blocking property by performing hot pressing or molding and laminating at the same time.

[0019]

In the film for laminating automobile interior materials according to the first aspect of the invention, the outer layer and the inner layer are made of polyethylene resin, and the intermediate layer is made of three layers made of synthetic resin having a melting point higher than that of polyethylene resin by 30 ° C. or more. There is. Therefore, the automobile interior material of the second invention obtained by adhering the skin material and the base material via the film has a surface portion where the outer layer adheres to the skin material and a surface portion where the inner layer adheres to the base material. Even if the intermediate layer is melted, the intermediate layer does not melt and maintains a sheet shape, so that the intermediate layer itself can maintain the air blocking function and the airtightness as the interior material.

[0020]

EXAMPLES Hereinafter, the film for laminating an automobile interior material of the first invention and the automobile interior material of the second invention will be described with reference to examples. (Example 1) As shown in Fig. 1, a film for laminating automobile interior materials of Example 1 (hereinafter referred to as "film")
1A is manufactured by an inflation molding method, and is composed of three layers including an outer layer 10a, an intermediate layer 11, and an inner layer 12, and has a total thickness of 75 μm (the outer layer 10, the intermediate layer 11, and , The thickness composition ratio with the inner layer 12 is 2:
1: 2).

The outer layer 10 is a linear low-density polyethylene (MI: 0.8 g / 10 min, density: 30 μm, density:
0.919 g / cm ³ , melting point: 120 ° C.). The intermediate layer 11 is made of a nylon 6/66 copolymer having a thickness of 15 μm (relative viscosity: 4.2, density: 1.12 g / cm ³ , melting point: 200 ° C.). The inner layer 12 has a thickness of 30 μm
Linear low-density polyethylene (MI: 0.8g / 10m
in, density: 0.919 g / cm ³ , melting point: 120 ° C.)
Consists of.

The film 1A comprises an outer layer 10a and an inner layer 12
Then, a skin material 2 for interior and a base material 3 for interior, which are prepared in advance and shown below, are adhered to each other to manufacture an automobile interior material 4A. The skin material 2 is made of a polyester non-woven fabric having a basis weight of about 170 g / m ² . The base material 3 was obtained by impregnating both surfaces of a mat-like material obtained by needle-punching glass fibers and thermoplastic fibers with high-density polyethylene and having a basis weight of about 650 g / m ^2.
belongs to.

The skin material 2 is the outer layer 10a of the film 1A.
, And they are placed on top of each other. Then, the skin material 2 and the film 1A are heat-bonded and integrated by a heat roller (not shown) having a surface temperature of about 130 ° C. The base material 3 is placed on the inner layer 12 of the film 1A integrated with the skin material 2 so as to overlap with each other,
After heating the surface of the inner layer 12 to about 170 ° C., an automobile interior material 4A was manufactured by press molding for 18 seconds with a clearance of about 4 mm using a molding die (not shown) having a surface temperature of about 50 ° C.

In the automobile interior material 4A obtained by using the film 1A of Example 1 and adhering the skin material 2 and the base material 3 with the film 1A interposed therebetween, the outer layer 10a of the film 1A has the skin material 2 Surface part and film 1 to be adhered to
Even if the inner layer 12 of A melts at the surface portion where it adheres to the base material 3, the intermediate layer 11 does not melt and maintains a sheet shape, so that the air barrier property of the intermediate layer 11 itself and the air barrier function as the interior material 4A. Excellent and can maintain airtightness.

Example 2 As shown in FIG. 1, a film for laminating an automobile interior material (hereinafter referred to as a film) 4B of Example 2 was produced by an inflation molding method and had an outer layer 10b. And the middle layer 11 and the inner layer 12
The total thickness is 7
5 μm (thickness composition ratio of outer layer 10b, intermediate layer 11, and inner layer 12 is 2: 1: 2). The film 1B of Example 2 is the same except that the outer layer 10b is different from the outer layer 10a of the film 1A of Example 1 above.

The outer layer 10b is made of low-density polyethylene (MI: 13 g / 10 min, density: 0.9) having a thickness of 30 μm.
19 g / cm ³ , melting point: 106 ° C.). Similar to the film 1A of Example 1, the film 1B is press-molded at the same time that the interior skin material 2 is adhered to the outer layer 10b and then the interior base material 3 is adhered to the inner layer 12. Car interior material 4B was manufactured.

An automobile interior material 4B obtained by using the film 1B of Example 2 and adhering the skin material 2 and the base material 3 via the film 1B has an outer layer 10b of the film 1B. Surface part and film 1 to be adhered to
Even if the inner layer 12 of b melts at the surface portion where it adheres to the base material 3, the intermediate layer 11 does not melt and maintains a sheet shape, so that the intermediate layer 11 itself has an air barrier property and an air barrier function as the interior material 4B. Excellent and can maintain airtightness.

Comparative Example Here, the film 1A of Example 1 was used.
In order to confirm the effects of the automobile interior materials 3A and 3B produced by using the film 1B of Example 2 and the film 1B of Example 2, respectively, the following films for laminating automobile interior materials of Comparative Examples 1 and 2 (hereinafter, referred to as film and Table 1 to 8 show the characteristics and characteristic values of the respective interior materials in the case of manufacturing an automobile interior material by using (hereinafter referred to as) and in the cases of the above-mentioned Examples 1 and 2.

Table 1 shows the workability of bonding to the skin material.
The air barrier property is shown in Table 2, the adhesive property with the skin material is shown in Table 3, Table 4, Table 5, and Table 6, and the hot adhesion retention property between the film and the substrate after the molding press is shown in Table 7. Table 8 shows the flammability after press molding. Comparative Example 1 Comparative Example 1 is a linear low-density polyethylene (MI: 0.8 g / 10 min, density: 0.919 g /
cm ³ , melting point: 120 ° C.) overall thickness of single layer 75
A film for bonding having a thickness of μm is manufactured by an inflation molding method, and under the same conditions as in Examples 1 and 2, a skin material is bonded to one surface of the film and a base material is bonded to the other surface, and press molding is performed. The obtained interior material is obtained by simultaneously performing.

Comparative Example 2 In Comparative Example 2, the intermediate layer was replaced with nylon 6/66 copolymer, and high density polyethylene (M
I: 0.6 g / 10 min, density: 0.950 g / cm
³ , melting point: 129 ° C.), a film having an overall thickness of 75 μm (thickness composition ratio 2: 1: 2) was produced by an inflation molding method in the same manner as in Example 2, and then, Examples 1 and 2 were used. Under the same conditions as described above, a skin material is adhered to one surface of the film, a base material is adhered to the other surface, and press molding is simultaneously performed, which is an interior material obtained.

[0031]

[Table 1] The case where the workability of laminating the film and the skin material was good was marked with ◯, the case where it was a little bad was marked with Δ, and the bad case was marked with x.

[0032]

[Table 2] <Air barrier property> The following numerical values show the air permeation amount per minute in an area of 28 mm under a pressure of 40 KPa. The airflow rates of Example 1, Comparative Example 1, and Comparative Example 2 are average values of four samples each, and the airflow rates of Example 2 are average values of 38 sample numbers.

[0033] Regarding dirt, the case where it was not found was marked with a mark, the case where it was found to be slightly marked, and the case where it was clearly found was marked with a mark.

[0034]

[Table 3] <Adhesiveness to skin material> Table 3 shows the evaluation when a peeling test was performed at room temperature (23 ° C) after the film was attached to a skin material for interior by a heat roll. The case where the adhesive strength with the epidermis was sufficiently obtained was evaluated as ◯.

[0035]

[Table 4] <Adhesiveness to Base Material After Molding Press> Table 4 shows that after the film was attached to the interior skin material by a heat roll, the film was further laminated and molded on the interior base material, Then, it is an evaluation when a peeling test between the film and the base material is performed at room temperature (23 ° C.).

[0036] When the adhesive strength with the substrate was sufficiently obtained, it was evaluated as ◯.

[0037]

<Table 5><After heat aging> Table 5 shows the evaluation when the same peeling test as in the case of the above Table 4 was performed after standing in an atmosphere of 85 ° C for 400 hours. When the adhesive strength with the substrate was sufficiently obtained, it was evaluated as ◯.

[0038]

[Table 6] <After wet aging> Table 6 shows the evaluation when a peeling test similar to the case of the above Table 4 was performed after the sample was left in an atmosphere having an atmospheric temperature of 50 ° C and a humidity of 90% for 400 hours. When the adhesive strength with the substrate was sufficiently obtained, it was evaluated as ◯.

[0039]

[Table 7] <Heat adhesion retention with base material after molding press> Table 7 shows that after a film is attached to the interior skin material by a heat roll, the film is further laminated on the interior base material. After molding, apply a constant load of 100g to the skin material side, then 85
It is an evaluation when a hot adhesion retention test between the film and the base material was carried out by leaving it in an atmosphere at a temperature of 24 hours for 24 hours.

[0040] The case where sufficient hot adhesion retention with the base material was obtained was evaluated as ◯.

[0041]

<Table 8><Combustibility after molding press> Table 8 shows that after the film is laminated on the interior skin material by a heat roll, the film is further laminated and molded on the interior base material, and then the combustion test is performed. It is an evaluation when performing. In addition, the combustion test,
FMVSS No. Evaluation was performed according to the test method specified in 302, and when the standard was satisfied, it was marked as ◯.

[0042]

【effect】

(1) The film for laminating an automobile interior material of the first invention is heated between an outer layer and an inner layer, and a part of the outer layer and the inner layer which are melted at the time of heating and reliably adhere to the skin material and the base material for the interior. Since it is provided with an intermediate layer that does not melt even if it is crushed, excellent air barrier properties can be maintained.

Further, according to the laminated film of the first invention, when various kinds of interior covering materials are heat-pressed with a heat roller or the like, stable adhesiveness can be obtained without impairing the air-blocking property, and heating can be performed. Workability at the time of crimping is good and it is possible to bond with high efficiency. Further, after the thermocompression bonding with the skin material, the molding process and the thermoforming press can be bonded to the substrate at the same time as shaping, so that the molding process can be rationalized. (2) An automobile interior material of the second invention comprises a film of the first invention which retains the excellent air barrier property, and an interior skin and a base material which are respectively bonded to the outer layer and the inner layer through the film. As a result, the overall strength of the interior material can be improved, and an excellent air barrier function and moisture barrier function can be obtained.

In the case of the automobile interior material of the second invention,
Even if the base material is made of a material that does not have an air blocking function and has air permeability, a highly efficient and stable air blocking function can be obtained by bonding and using the laminating film of the first invention to the base material. To be Therefore, according to the automobile interior material of the second aspect of the present invention, polluted air contaminated with dust, cigarette smoke, and the like inside the vehicle interior, and polluted air outside the vehicle interior do not penetrate the interior material, so It is possible to prevent the interior material from being contaminated due to the penetration and contact of the interior material.

Further, according to the automobile interior material of the second invention,
Since it does not require a film that is used only for the air blocking function that is often used for conventional interior materials and an adhesive application process dedicated to bonding skin materials, it has excellent productivity and does not require the use of an adhesive. Therefore, it is economical and can be made lighter than the conventional interior material.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an enlarged cross section of a main part of a film for laminating an automobile interior material and an automobile interior material in Examples 1 and 2 of the present invention.

[Explanation of symbols]

1A, 1B ... Laminating films 10a, 10b
Outer layer 11 ... Middle layer 12 ... Inner layer 2 ... Skin material 3 ... Base material 4A, 4B ... Interior material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiki Uehara 2-9-3 Miyawakicho, Takamatsu City, Kagawa Prefecture

Claims (5)

[Claims] 1. A film for laminating automobile interior materials, wherein the outer layer and the inner layer are made of a polyethylene resin, and the intermediate layer is made of a synthetic resin having a melting point higher by 30 ° C. or more than the polyethylene resin. 2. The melt index of the outer layer is 5.0 to 3.
0.0 g / 10 min. , The melt index in the inner layer is 5.0 g / 10 min. The film for laminating automobile interior materials according to claim 1, wherein a polyethylene resin of less than 1 is used. 3. The melting point of the polyethylene resin used for the inner layer is 10 ° C. higher than the melting point of the polyethylene resin used for the outer layer.
The film for laminating an automobile interior material according to claim 1 or 2, which is higher than the above. 4. The film for laminating automobile interior materials according to claim 1, 2 or 3, wherein the synthetic resin of the intermediate layer is nylon or ethylene-vinyl alcohol co-polymer synthetic resin. 5. An outer layer and an inner layer are made of a polyethylene-based resin, and an intermediate layer is bonded to a skin material and a substrate through a laminating film made of a synthetic resin having a melting point higher than that of the polyethylene-based resin by 30 ° C. or more. Interior materials for automobiles, which are characterized by being