JPH05194756A - Production of automotive interior material - Google Patents

Abstract

PURPOSE:To diminish production steps by using an adhesive which does not need a high temp. for application or for bonding to an adherend, has good heat resistance, and shows good workability in application and bonding. CONSTITUTION:A moisture-curable hot-melt adhesive 3 containing at least 30wt.% isocyanate-terminated urethane prepolymer is applied to a substrate 2 at 70-140 deg.C. A surface material 4 is then pressed against the substrate 2 at an adhesive layer temp. of 40-150 deg.C to thereby produce an automotive interior material having a muitilayer structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an automobile interior material having a laminated structure in which a skin material is attached to a base material with an adhesive.

[0002]

2. Description of the Related Art For automobile interior materials such as ceiling materials, door interior materials, sheets, panels, etc., a skin material is adhered to various base materials having irregularities for soundproofing, heat insulation, decoration, shock absorption and the like. A laminated body having a laminated structure is used.

To bond the base material and the skin material, a solvent type adhesive such as urethane type or chloroprene type, or a film type hot melt type adhesive such as polyamide or nylon is used.

[0004]

However, solvent-type adhesives are uneconomical in terms of equipment, such as 1) requiring a drying step, 2) requiring explosion-proof equipment for fire prevention, and There are also problems such as the possibility of pollution caused by solvents.

In addition, a usual hot melt type adhesive requires a high temperature of 150 ° C. to 200 ° C. for application and adhesion, and since this adhesive is a thermoplastic resin having a low heat resistant temperature, it is heat resistant. The places to be used are limited in places where sex is required and where force is applied.

[0006] As a solvent-free and heat-resistant adhesive agent, an epoxy type adhesive agent, a one- or two-component urethane type adhesive agent, etc. can be mentioned. When it is used for bonding, peeling easily occurs, and therefore it is necessary to fix the base material to be bonded and the skin material by a clip or press for a long time.
In addition, there is a problem that the base material is deformed or damaged because it is heated to a high temperature of 150 ° C. or higher during thermosetting.

In view of the above points, the present invention is not required to be applied and adhered at a high temperature, has good heat resistance, has good workability during application and adhesion, has high safety, and shortens the manufacturing process. It is an object of the present invention to provide a method for manufacturing a possible automobile interior material.

[0008]

The method for producing an automobile interior material of the present invention is a method for producing an automobile interior material having a laminated structure by laminating a skin material on a base material with an adhesive. In the above, a moisture-curable hot melt adhesive containing at least 30% by weight or more of a urethane prepolymer having an isocyanate group at a terminal is used as a base material at 70 ° C to
It is characterized in that it is applied at an application temperature of 140 ° C., then the temperature of the applied adhesive is adjusted to 40 ° C. to 150 ° C., and the skin material is pressure-bonded to the base material.

As the base material, fibers are impregnated with a thermosetting resin such as urea resin, melamine resin or phenol resin,
A flat plate or one molded into a predetermined shape, or a thermoplastic resin such as polyethylene, polypropylene, noryl, ABS or the like, or a flat plate or a predetermined plate obtained by impregnating these thermoplastic resins with glass fiber, an inorganic filler, a fiber waste, or the like. It is possible to use those molded in the above shape.

As the skin material, a foamed material made of a thermoplastic resin such as urethane, polyethylene, polypropylene or vinyl chloride resin, or a cloth material such as a non-woven fabric, a woven fabric or a knitted fabric can be used alone or in combination. Further, a knit, a cloth, a leather or a thermoplastic resin sheet made of a thermoplastic resin such as a vinyl chloride resin or a TPE resin may be used, or these may be laminated on the above skin material.

In the present invention, the urethane prepolymer refers to a urethane prepolymer having an isocyanate group at the terminal obtained by the reaction of a polyol having a hydroxyl group at the molecular terminal and a polyisocyanate having an isocyanate group at the molecular terminal.

As the above-mentioned polyol, it is possible to use a known polyol which is usually used in the production of polyurethane. Examples of such polyols include polyethylene adipate, polydiethylene adipate, polytetramethylene adipate, polyneopentyl adipate, polyhexamethylene adipate, polymethylpentane adipate, polyethylene succinate, polyethylene sebacate, polytetramethylene sebacate, polyhexahexene. There are polyolefin polyols such as methylene sebacate, polyhexamethylene decandioate, polyester polyols such as poly-ε-caprolactoneol, polyethylene glycol, polyether polyols such as polytetramethylene glycol, polybutadiene polyol and hydrogenated products thereof, etc., These may be used alone or in combination of two or more.

Further, as the above polyisocyanate,
It is possible to use a known polyisocyanate which is a compound having at least two isocyanate groups in the molecule and which has been conventionally used for producing polyurethane.

Examples of such polyisocyanates include:
Examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, liquid modified products of diphenylmethane diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate.

Moisture-curable hot melt adhesives include, as compounds other than the above urethane prepolymer, tackifying resins such as rosin-based resins, terpene-based resins, aliphatic and aromatic petroleum resins, ethylene-vinyl acetate resins, Ethylene
Saponified vinyl acetate resin, ethylene-acrylic acid (ester) copolymer resin, ethylene-acrylic acid (ester) -carbon monoxide copolymer resin, styrene-isoprene-
Styrene copolymer (SIS), styrene-butadiene-
Thermoplastic resins such as styrene copolymer (SBS), styrene-ethylene-butadiene-styrene copolymer (SEBS), α-olefin copolymer, paraffin wax,
Waxes such as microcrystalline wax, catalysts such as organometallic compounds and tertiary amine compounds may be added.

As a coating method, the base material or the skin material or both surfaces thereof can be applied by spraying or rolls. Also, a coating method combining both of them may be used.

The application temperature of the moisture-curable hot melt adhesive used in the present invention is more preferably 90 ° C to 130 ° C. This is because when applied in this temperature range, a melt viscosity suitable for application, that is, a melt viscosity of 500 to 30,000 cps can be obtained.

It is more preferable that the base material and the skin material are adhered to each other while the temperature of the adhesive is maintained within the range of 60 ° C to 130 ° C. For reheating the adhesive for this purpose, far infrared rays or a heating furnace can be used.

Further, it is also possible to form the base material at the same time as adhering the skin material to the base material, without using the base material previously formed into the predetermined shape to form the interior material into the predetermined shape. In this case, after the adhesive is applied to the base material, the skin material, or both, molding of the base material and adhesion of the skin material to the base material are simultaneously performed by hot pressing or the like. In this case, the molding temperature of the heat press molding falls within the temperature range of 40 ° C. to 150 ° C. of the adhesive required for bonding, so that the condition of the adhesive temperature is inevitably satisfied.

[0020]

By using a moisture-curable hot melt adhesive containing at least 30% by weight or more of urethane prepolymer having an isocyanate group at the terminal, 70 ° C to 140 ° C
The required amount of adhesive can be applied to the substrate or the skin material or both at a coating temperature of ° C. Further, the base material and the skin material can be bonded at an adhesive temperature of 40 ° C to 150 ° C. Therefore, at the time of application and adhesion, 150 ℃ -200 ℃
It is not necessary to use an adhesive that requires a high temperature such as, and the bonding between the base material and the skin material can be performed at a low temperature.

[0021]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. The moisture-curable hot melt adhesive containing at least 30% by weight or more of the urethane prepolymer having an isocyanate group at the terminal used in the present invention was prepared as follows.

(Preparation of Adhesive) Equivalent ratio to the hydrogenated polyolefin polyol (Mitsubishi Kasei Co., Polytail HA) [NC
Diphenylmethane diisocyanate (MDI) was mixed at 80 ° C. so that O] / [OH] = 2.1 and reacted for 5 hours under a nitrogen atmosphere to obtain a viscous urethane prepolymer at room temperature. Aromatic petroleum resin (FTR-6100, Mitsui Petrochemical Co., Ltd.) was added to 200 g of this urethane prepolymer.
250 g, ethylene-butyl acrylate-carbon monoxide copolymer resin (DuPont, EP4043) 50 g, and tertiary amine compound (San Apro, U-2041) 2 g
Was heated and mixed at 150 ° C. and deaerated under reduced pressure to obtain a moisture-curable hot melt adhesive. The obtained adhesive has a melt viscosity of 3
000 cps (at 120 ° C), R & B method (JIS K
The softening point according to 2207) was 65 ° C.

Next, examples and comparative examples of the present invention using this moisture-curable hot melt adhesive will be described. (Example 1) A molded into a shape as shown in FIGS.
The base material 1 made of BS was spray coated with the above adhesive at 120 ° C. so as to have a weight of 50 g / m ² . After that, the base material 1 spray-coated with a far infrared device is heated for 45 seconds, and immediately the polyethylene foam side of the skin material made of polyethylene foam laminated with a soft vinyl chloride sheet is directed toward the base material 1 and 0.4 kg / cm ² The pressure was applied to the base material 1 for 20 seconds. Then, it was cured for 24 hours in an atmosphere of 20 ° C. and a relative humidity of 65% (RH). The temperature of the adhesive at the time of adhesion was 70 ° C. when measured with a surface thermometer.

Comparative Example 1 After applying the adhesive, the above skin material was adhered to the substrate 1 without reheating the adhesive with a far infrared device. Otherwise, the same method as in Example 1 was carried out. The temperature of the adhesive at the time of adhesion was 30 ° C.

Example 2 As shown in FIGS. 3 and 4,
Rolled on a flat plate substrate 2 (1.5 m x 2 m x 5 mm) in which glass fibers are laminated on a polystyrene board with a roll of 70 g / m
^The above adhesive 3 was applied at 120 ° C. so as to be ² .
This is heated in a heating furnace at 130 ° C. for 1 minute, and immediately a skin material 4 (1.7 m × 2.2 m × 3 mm) made of a non-woven fabric is overlaid, and a pressure of 0.5 kg / cm ² is applied with a mold having a predetermined shape. And press molded for 30 seconds. Then, it was cured for 24 hours in an atmosphere of 20 ° C. and a relative humidity of 65% (RH). The temperature of the adhesive at the time of adhesion was 100 ° C.

(Comparative Example 2) A one-component urethane adhesive (Esdyne 505, Sekisui Chemical Co., Ltd.) was applied as an adhesive with a roll at room temperature. Except for this, the same method as in Example 2 was used.

Next, Table 1 shows the results of initial appearance, material breakage rate and heat resistance of Examples 1 and 2 and Comparative Examples 1 and 2. The evaluation method was as follows.

Initial appearance The interior material immediately after bonding was left in an atmosphere of 30 ° C. for 1 hour and the skin material was visually observed for floating, peeling and damage. Destruction rate 24 hours The skin material of the interior material that has been cured is peeled off from the end by hand, and the destructed state of the skin material (destructed state of the skin material) is observed. It was divided by the area and expressed in%.

Heat resistance: 9 hours of interior material cured for 24 hours
After standing in an oven at 0 ° C. for 24 hours, the skin material was visually observed for floating, peeling and breakage.

[0030]

[Table 1]

^* The skin material in the deeply squeezed portion was peeled off from the adhesive interface and floating occurred. ^{** The} skin material peeled off due to cohesive failure of the adhesive. No abnormalities were found in the initial appearance and heat resistance in Examples 1 and 2,
The material breakage rate was also good and good results were obtained.

[0032]

EFFECT OF THE INVENTION By using a moisture-curable hot melt adhesive containing at least 30% by weight or more of urethane prepolymer having an isocyanate group at the terminal, the base material and the skin material can be adhered at a low temperature. Therefore, problems such as deformation and damage of the interior material caused by using the adhesive which requires high temperature are solved.

Since the work of applying the adhesive and the work of adhering the base material and the skin material can be performed at a low temperature, workability is improved and the time required for heating is shortened, and the manufacturing process can be shortened.

Since the adhesiveness is good, the skin material can be adhered to the base material while maintaining the strength of the skin material. Since it has good heat resistance, it can be used in places where heat resistance is required or where force is applied.

Since no solvent is used, there is no risk of pollution caused by the solvent, and the product can be manufactured safely.

[Brief description of drawings]

FIG. 1 is a plan view of a base material used in Example 1 of the present invention.

2 is a cross-sectional view of the substrate of FIG.

FIG. 3 is a plan view of an automobile interior material obtained in Example 2 of the present invention.

4 is a cross-sectional view of FIG.

[Explanation of symbols]

 1, 2 Base material 3 Adhesive 4 Skin material

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Claims (1)

[Claims] 1. A method for producing an automobile interior material having a laminated structure by laminating a skin material to a base material using an adhesive, wherein at least 30 parts by weight of a urethane prepolymer having an isocyanate group at a terminal is used. %
Moisture-curable hot melt adhesive containing the above is used as a base material at 70 ° C.
A method for producing an automobile interior material, which comprises applying the coating material at a coating temperature of 140 ° C to 140 ° C, and then applying pressure of the applied adhesive to 40 ° C to 150 ° C to press-bond the skin material to the base material.