JPH08300577A - Precoating skin material for automobile internal trim - Google Patents

Abstract

PURPOSE: To rationalize sticking work by precoating a skin material side with an adhesive having, as main components, a styrene copolymer endowed with a functional group and a crosslinker for sticking the skin material which forms an automobile part to a base material and heating and sticking it, and to provide an automobile trim material part having excellent heat resistance and complicated shape. CONSTITUTION: An adhesive having a styrene copolymer endowed with a functional group and a crosslinker as main components is previously applied on a polyolefin foam of a skin material having a polyolefin foam layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-coated skin material for automobile interiors, which is capable of greatly simplifying the bonding process for producing automobile interior materials.

[0002]

2. Description of the Related Art Interior materials such as doors and instrument panels are used in automobiles. These interior materials are generally composed of a skin material and a base material. Usually, a solvent type adhesive is used to bond the two, and the skin material is heat-molded and bonded to the shape of the base material. The skin material used here is polyvinyl chloride,
Thermoplastic olefin and other plastic sheets and surface materials such as tricot, cloth and non-woven fabric and other fiber materials are laminated with polypropylene, polyethylene, polybutylene, and foams made from these copolymers as the main component, and bonded by heat. It is a material that is laminated by fusion or the like. The thickness of the surface coating is about 0.5 mm to 1.5 mm,
The thickness of the polyolefin foam is 1.5 mm to 3.0 m
Those of about m are generally used. The base material used here is an injection-molded product of various plastics such as acrylonitrile / butadiene / styrene (ABS) and polypropylene resin, and wood made by thermopressing wood chips, wood powder, etc. with thermosetting resin. It means molded products such as boards.

[0003]

At this time, the solvent-based adhesive is directly applied to a molding base material such as a door, and immediately after being dried, it is transferred to a vacuum molding step. As the adhesive, for example, a chloroprene rubber type, a nitrile rubber type, a urethane type, an acrylic type, a polyester type or the like is used. These adhesives are used by spray coating, but they are a major problem because they have many losses due to scattering, are prone to uneven coating, and are toxic to the human body due to volatilization of organic solvents. It was However, since the interior material has a complicated shape, there is no good means other than spraying, and with the conventional adhesive, good solution to the base material surface is required unless the solution is directly applied to the molding base material. There was a serious problem that the adhesiveness could not be obtained.
For this reason, continuous coating of the adhesive is impossible, and it is the current situation that the coating operation must be performed on each of the formed substrates.

[0004]

DISCLOSURE OF THE INVENTION The present invention has found that pre-coating an adhesive on a skin material makes it possible to largely omit the bonding step, and further, the above drawbacks can be greatly improved. is there. The present invention, an adhesive containing a functional group-added styrene copolymer and a crosslinking agent as main components, of a skin material having a polyolefin foam layer,
The present invention relates to a pre-coated skin material for an automobile interior, which is applied on a polyolefin foam in advance.

According to the pre-coated skin material of the present invention, at the time of heat-molding the skin material, at the same time, the pre-coated adhesive can be softened and then the skin material and the base material can be bonded to each other.

The styrene copolymer used in the present invention means styrene / isoprene / styrene copolymer, styrene / butadiene / styrene copolymer, styrene / ethylene / butylene / styrene copolymer, styrene / ethylene / propylene / styrene. It is a copolymer or the like. As the styrene copolymer having a functional group here, for example, a copolymer having a carboxyl group and the like are known.
The functional group may be subjected to an addition reaction in a solution or emulsion.

Regarding such addition reaction, (meth) acrylic acid, itaconic acid, maleic acid, salicylic acid, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) ) Acrylate, glycidyl allyl ether, acrylamide, dimethylaminoethyl methacrylate, (anhydrous) phthalic acid, vinyl alcohol and the like can be obtained by addition reaction using a radical initiator. Similarly in an emulsion obtained by emulsifying the copolymer,
The functional group and the like may be reacted.

The cross-linking agent may be any one capable of reacting with the above-mentioned functional group, for example, a functional group having active hydrogen,
Polyisocyanate, melamine resin, epoxy resin, oxazoline, etc., or polyamine, dicyandiamide, imidazole, urea resin, dialdehyde, oxazoline, etc. can be used as long as they are glycidyl groups. Since the cross-linking agent needs to be coated with the adhesive in advance to form a film, it is necessary to adjust it so that it is activated later.
It is preferable that the gel fraction of the adhesive is in the range of about 5 to 50%. If the gel content is less than 5%, the heat resistance of the adhesive will be insufficient and peeling of the skin material will occur.
When it exceeds, the adhesive film is too tough and the adhesiveness to the substrate cannot be obtained.

In order to obtain adhesion to the substrate, it is preferable to add an adhesion-imparting resin. For example, aliphatic petroleum resin, aromatic petroleum resin, terpene resin, coumarone-indene resin, rosin resin, epoxy resin, phenol resin, acrylic resin, butyral resin, chlorinated olefin resin,
Adhesiveness can be obtained by selecting one or more of vinyl acetate resins and modified resins thereof and mixing them in appropriate amounts. The preferred blending amount is 50 to 150 parts by weight.
Parts by weight.

In addition to these, stabilizers, pigments, fillers, antiblocking agents and the like can be added as required. In applying the thus obtained precoat adhesive to the polyolefin foam surface of the skin material, after the skin material is manufactured, it may be directly applied using a knife coater, a reverse coater, a gravure coater, a curtain coater or the like and dried. Alternatively, it may be dried on the release paper and then transferred to the surface of the foam by heat transfer. The present invention thus has a great advantage that the adhesive layer can be provided on the surface material by continuous coating.

[0011]

The pre-coated skin material for automobile interior obtained by applying the pre-coat adhesive can be cut into a predetermined size and mounted in a vacuum forming machine to be immediately molded. In vacuum forming, the attached pre-coated skin material is heated and softened by hot air drying or far-infrared heating, and the pre-coated skin material is adhered while vacuum is drawn from the surface of the pre-formed base material attached to the convex mold of molding. The agent surface is closely adhered to the base material for adhesion. At this time, the base material is more preferably heated to about 30 to 60 ° C., and the precoat skin material is required to be heated to the range of 100 to 140 ° C. at the time of bonding. Furthermore, upon vacuum suction adhesion, a method of applying pressure from the surface of the skin with a compressed air, a concave type, a membrane, etc. is also common and a preferable result can be obtained.

[0012]

EXAMPLES Next, the present invention will be described in more detail by way of examples and comparative examples, and the results of these specific examples are shown in Table 1, but the present invention is not limited to these examples. In the text, all parts are parts by weight.

(Example 1) 100 parts of a styrene / butadiene / styrene copolymer (Califlex KX65; manufactured by Shell Chemical Co.) was dissolved by heating and stirring at 80 to 100 ° C in a flask in which 300 parts of toluene was replaced with nitrogen. After that, a solution of 0.5 part of benzoyl peroxide was added dropwise using 20 parts of acrylic acid as a radical initiator to carry out graft polymerization. Keep the inside of the flask at 80-100 ° C for 3
The mixture was heated and stirred for a period of time, and 0.5 part of hydroquinone was added as a terminating agent to stop the reaction. After cooling, 50 parts of rosin resin (Super Ester A115; manufactured by Arakawa Chemical Co., Ltd.) and 50 parts of petroleum resin (Alcon P125; same) were added and dissolved. Further, 1 part of a stabilizer (Tinuvin 326; manufactured by Sumitomo Bayer) was added to obtain an adhesive (I). Adhesive (I) solid content 10
1 part of solid content of oxazoline (1,3PBO; manufactured by Takeda Yakuhin Kogyo Co., Ltd.) was added to 0 parts by weight, and the mixture was stirred and mixed to form an automobile interior skin material (a surface material made of a polyvinyl chloride sheet and 20 times foaming mainly composed of polypropylene). A laminated product having a thickness of 2 mm; manufactured by Okamoto Co., Ltd.) was coated on a polypropylene foam surface using a knife coater, and dried for 2 minutes in a drying oven set at 80 ° C. to form an adhesive coating film of 80 μm. A precoated skin material for automobile interior was obtained. The precoated skin material was heated to a surface temperature of 140 ° C. and bonded to a polypropylene molding substrate that had been previously molded by vacuum molding. The adhesive was cured by oxazoline, and a final bond having high strength and excellent heat resistance was obtained.

(Example 2) In the same manner as in Example 1, 80 parts of a styrene / butadiene / styrene copolymer (Califlex KX65; manufactured by Shell Chemical Co.), a styrene / ethylene / butylene styrene copolymer (Kraton G165) were used.
0: Shell Chemical Co., Ltd.) was graft-polymerized with 20 parts of hydroxyethyl acrylate. After cooling, 80 parts of petroleum resin (Alcon P125; manufactured by Arakawa Chemical Co., Ltd.) and 20 parts of terpene resin (Clearon P105; manufactured by Yasuhara Yushi Kogyo Co., Ltd.) were added and dissolved. Further, 1 part of a stabilizer (Tinuvin 326; manufactured by Sumitomo Bayer Co., Ltd.) was added to obtain an adhesive (II). To 100 parts by weight of the solid content of the adhesive (II), 4 parts by weight of polyisocyanate (Coronate L; manufactured by Nippon Polyurethane Industry Co., Ltd.) was added and mixed by stirring. The adhesive was cured by polyisocyanate, and a final bond having high strength and excellent heat resistance was obtained.

(Example 3) In the same manner as in Example 1, 50 parts of styrene / butadiene / styrene copolymer (Califlex KX65; Shell Chemical Co.), styrene / isoprene / propylene styrene / styrene copolymer (Septone) 2063; 20 parts of glycidyl acrylate was graft-polymerized to 50 parts of Kuraray Co., Ltd.). After cooling, 100 parts of petroleum resin (Alcon P125; manufactured by Arakawa Chemical Co., Ltd.) was added and dissolved. Further, 1 part of a stabilizer (Tinuvin 326; manufactured by Sumitomo Bayer) was added to obtain an adhesive (III). Adhesive (II
To 100 parts by weight of the solid content of I), 1 part of imidazole (Curezole 2PZ-CNS; manufactured by Shikoku Chemicals Co., Ltd.) solid content was added and dissolved by stirring. Upon curing, the adhesive gave a final bond having high strength and excellent heat resistance.

[0016]

[Comparative example]

(Comparative Example 1) The cross-linking agent was not added to the adhesive obtained in Example 1 and pre-coated on the polypropylene foam surface of the skin material for automobile interiors and laminated with the substrate. (Adhesive strength) A skin material laminated with a base material was cut into a width of 25 mm, and a pulling speed of 200 mm / min was applied at 1 at each temperature.
Peeling was performed at 80 degrees, and the strength and the fracture state were tested. 20
Material peeling of the skin material was observed during peeling in an atmosphere of 90 ° C., but cohesive failure of the adhesive resulted in peeling in the atmosphere of 90 ° C., resulting in a decrease in adhesiveness.

(Comparative Example 2) The adhesive obtained in Example 2 was precoated on the polypropylene foam surface of a skin material for automobile interior without attaching a functional group to the adhesive, and the adhesive was bonded to a substrate. (Adhesive strength) In the same manner as in Comparative Example 1, the material destruction of the skin material was observed at 20 ° C peeling, but the adhesive was cohesively destroyed at 90 ° C peeling, and the adhesiveness was deteriorated.

[0018]

[Table 1]

[0019]

As described above, the pre-coated skin material for automobile interiors, which is capable of greatly simplifying the bonding process for producing automobile interior materials, has good moldability and does not cause floating. Showed good adhesion.

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Claims (1)

[Claims] 1. A styrene copolymer having a functional group and an adhesive containing a cross-linking agent as a main component, which is applied in advance on a polyolefin foam of a skin material having a polyolefin foam layer. A pre-coated skin material for automobile interiors.