JP2004359920A - Welding material for repairing broken part of resin, having improved bonding property with rigid resin material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the bonding property of a welding material for repairing a broken part of a polyolefin resin molded article at a boundary surface with the broken part. <P>SOLUTION: The bonding property of boundary of the both materials is improved by saturating the double bond of conjugated diene part of an SEBS (styrene/ethylene/butadiene/styrene block copolymer) used as a welding material of a polypropylene composite material by ≥60% so as to have a high compatibility with a PP component and an EP rubber component in the polyolefin-based hard resin at the broken part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molded part for automobile interior and exterior using a polyolefin resin, and more particularly, to an automobile bumper, an aero part, a dashboard, a door trim, a trim and a floor console.
[0002]
2. Description of the Related Art Polyolefin resins frequently used in automotive interior and exterior parts are difficult to adhere to each other, and when damaged by collision or the like, there is no appropriate repair method such as welding for sheet metal parts. Has been disposed of. Some have attempted to use materials of the same quality and weld them with hot air or the like. However, since there is no compatibility between the two materials, sufficient strength cannot be obtained and the application cannot be expanded. On the other hand, due to recent environmental considerations, waste reduction has become an urgent task, and interest in repairs is increasing. Against this background, there is a demand for a suitable repair material for polyolefin resin parts.
[0003]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a repair resin welding material having an oil component which does not contain an oil component and which has improved compatibility with a polyolefin resin which is a hard resin material. Alternatively, by applying SEBC alone or a blended material with polyolefin resin, it can be easily melted by hot air, infrared irradiation, etc., and has high adhesion to the hard resin material on the mating side for repair. I will provide a.
[0004]
Means for Solving the Problems In order to achieve the above object, the saturation of the double bond of the conjugated diene portion of SEBS or SEBC (hereinafter referred to as the saturation) is saturated by 60% or more, so that the polyolefin resin and To improve the compatibility at the interface.
[0005]
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist thereof.
[0006] SEBS, polyolefin, and talc are kneaded as a repair welding material, and a rod-shaped molded product is prepared using an extruder. On the other hand, two polyolefin hard resins molded by an injection molding machine were attached to each other, and the area between them was bonded as shown in FIG. 1 with a repair welding material melted by hot air to evaluate the bonding strength. SEBS prepared several kinds from which the saturation of the double bond of a conjugated diene part differs. For comparison, a test piece was prepared in which a polyolefin hard resin serving as a mating partner was used as a welding material. Both ends of these test pieces were gripped, stretched at a speed of 50 mm / min, and a load was applied to the joint interface to cause breakage. The quality of the adhesiveness was determined based on the following criteria.
：: 100% cohesive failure (putty material destroyed)
△: Cohesive failure and interfacial fracture mixed ×: 100% interfacial fracture (peeling off at interface between hard resin material and putty material)
In the case of SEBS having different degrees of saturation, the adhesiveness to the hard resin material was improved from a point where the degree of saturation exceeded 40%, and stabilization was observed when the degree of saturation exceeded 60%. On the other hand, in the case where the polyolefin-based hard resin was used as the welding material, 100% interfacial peeling occurred, and no adhesiveness was observed. FIG. 2 shows the evaluation results.
[Brief description of the drawings]
FIG. 1 is a diagram of a test piece for evaluating adhesiveness.
FIG. 2 is a diagram of an evaluation result.

Claims (1)

The following (A) is defined as a mating hard resin material, and a composition comprising (A) 0 to 95% by mass and (B) 100 to 5% by mass is defined as a repair resin welding material.
The composition may contain various additives as necessary, for example, an antioxidant, a light-resistant material, a light stabilizer, and a reinforcing material such as talc.
(A) Polyolefin-based resin (b) A hydrogenated diene-based copolymer having a number average molecular weight of 50,000 to 700,000, wherein the double bond of the conjugated diene portion of the conjugated diene-based copolymer is saturated by 60% or more. For example, it refers to a styrene ethylene butadiene styrene block copolymer (hereinafter, referred to as SEBS) or a styrene ethylene butadiene olefin crystal block copolymer (hereinafter, referred to as SEBC).

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