JP2004034326A - Composite molded object of thermoplastic elastomer and metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a composite molded object comprising a flexible thermoplastic elastomer, which has high bonding force, durability and good moldability, and a rigid metal. <P>SOLUTION: The composite molded object comprises the thermoplastic elastomer and the metal. A part or the whole of the metal is coated with a thermoplastic resin having affinity to the thermoplastic elastomer and having a tensile elastic modulus of ≥1 GPa and the metal coated with the thermoplastic resin and the thermoplastic elastomer are subjected to composite molding to obtain the composite molded object of the thermoplastic elastomer excellent in bonding strength with the metal. In a preferable mode, the thermoplastic elastomer is an olefinic thermoplastic elastomer and the thermoplastic resin comprises a polypropylene resin to show excellent bonding properties. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a composite molded article made of a flexible thermoplastic elastomer and a rigid metal. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite molded article of a thermoplastic elastomer and a metal, which are two materials having extremely different properties, but are strongly bonded even in a severe use environment and have excellent durability.
[0002]
[Prior art]
The development of a composite molded body composed of a flexible rubber material and a metal material has been studied for a long time, and an excellent adhesive between the rubber material and the metal has been developed. The metal part coated with the adhesive and the rubber material are chemically bonded by composite molding to obtain a composite molded article of rubber and metal having strong adhesive force, which has been used for a long time as an automobile part or an industrial part. .
[0003]
However, recently, there has been a strong demand for recycling of materials used in automobile parts and the like for preserving the global environment. Also, some home appliances are required by law to recycle materials. In such an environment, there are many problems in recycling a rubber material, and applications of replacing the rubber material with a thermoplastic elastomer that is easily recycled are increasing. In addition, in molding rubber, there is a problem that a molding cycle is long, and burrs are often generated on molded products, and it takes time and labor to remove burrs of molded products, resulting in extremely high processing costs.
Under such circumstances, in a composite molded product made of rubber and metal, the rubber material is replaced with a thermoplastic elastomer having equivalent characteristics, and the bonding strength is strong and the thermoplastic elastomer and metal have excellent durability. There is a strong demand for the development of composite moldings.
[0004]
[Problems to be solved by the invention]
The present invention has been made against the background of the problems of the prior art, and is a combination of a flexible material and a rigid material having completely different properties of a thermoplastic elastomer and a metal. It is an object of the present invention to provide a composite molded article of a thermoplastic elastomer and a metal having a good quality at a low cost.
[0005]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, completed the present invention.
That is, the present invention relates to (1) a composite molded article of a thermoplastic elastomer and a metal, which is a thermoplastic resin having an affinity for the thermoplastic elastomer and having a tensile modulus of 1 GPa or more or a part of the metal. It is a composite molded article of a thermoplastic elastomer and a metal having excellent bonding strength, which is obtained by composite-molding a metal coated with a thermoplastic resin and a thermoplastic elastomer after coating and molding the whole. .
[0006]
In a preferred embodiment, (2) the thermoplastic elastomer is an olefin-based thermoplastic elastomer, and the thermoplastic resin is a polyolefin-based resin. In a more preferred embodiment, (3) the thermoplastic elastomer is an olefin-based thermoplastic elastomer, and the thermoplastic resin is a polypropylene resin.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described specifically.
The thermoplastic elastomer (hereinafter referred to as TPE) in the present invention is an elastic material that does not need to be vulcanized like rubber, and generally comprises a hard component (hard and rigid component) and a soft component (soft and flexible component). It is a composed material. There are many types of TPE, and examples of the TPE used in the present invention include olefin-based TPE, styrene-based TPE, polyester-based TPE, and urethane-based TPE.
[0008]
The olefin-based TPE includes a dynamic cross-linking type, a blend type, and a polymerization type, and any olefin-based TPE can be used. The constituent components of the olefin-based TPE include, for example, polypropylene and polyethylene as hard components, ethylene / propylene copolymer, ethylene / propylene / gen copolymer (EPDM), butyl rubber (IIR) and flexible ethylene copolymer as soft components. It is composed of a polymer or the like.
[0009]
Examples of the styrene-based TPE include styrene / butadiene / styrene block copolymer (SBS), styrene / isoprene / styrene block copolymer (SIS), styrene / ethylene / butylene / styrene block copolymer (SEBS), styrene / Ethylene / propylene / amylene / styrene block copolymer (vinyl SEPS), styrene / butadiene copolymer (HSBR) which is a hydrogenated product of styrene / butadiene copolymer, and the like.
Examples of the polyester-based TPE include, for example, TPE composed of polybutylene terephthalate and polynaphthalene terephthalate as a hard component and polytetramethylene glycol and polycaprolactone as a soft component.
There are many types of polyurethane TPE such as polyester type and polyether type, and any type of polyurethane TPE can be used.
[0011]
Examples of the metal forming a part of the composite molded body in the present invention include various steel materials that are iron alloys, copper alloys, and light metal alloys such as aluminum and magnesium, but are not limited thereto. Not something.
[0012]
In the thermoplastic resin having an affinity for TPE and a tensile modulus of 1 GPa or more in the present invention, having affinity means that the thermoplastic resin has a small difference in solubility parameter value from the solubility parameter value of TPE. , TPE and finely disperse when melt kneaded.
For example, the difference between the solubility parameter values ((cal · cm ⁻³ ) ^1/2 ) is 2 or less, preferably 1 or less. (Chemical Handbook-Advanced Edition, edited by The Chemical Society of Japan, 2nd revised edition, 830 pages, value by Small's method)
The following thermoplastic resins can be given depending on the type of TPE.
[0013]
Examples of the thermoplastic resin having an affinity for TPE with respect to polyolefin-based TPE and having a tensile modulus of 1 GPa or more include polyolefin-based resins, for example, polypropylene resins such as isotactic polypropylene and syndiotactic polypropylene, Examples include polyethylene resins such as ultra-high molecular weight polyethylene, high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, and low-density polyethylene, poly (1-butene) resin, and poly (4-methylpentene-1) resin. Can be done.
[0014]
Examples of the thermoplastic resin having affinity with TPE to styrene-based TPE and having a tensile modulus of 1 GPa or more include polystyrene resins such as general-purpose and impact-resistant resins, acrylonitrile-butadiene-styrene (ABS) resin, and acrylonitrile-styrene ( Styrene resins such as AS) resin. In addition, as a special styrene-based TPE, which is compatible with HSBR TPE and has a modulus of elasticity of 1 GPa or more, in addition to the styrene-based resin, the compatibility with a polypropylene resin is extremely excellent, and a polypropylene resin is used. You can do it.
[0015]
Thermoplastic resins having an affinity for TPE to polyester-based TPE and having a tensile modulus of 1 GPa or more include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) polycarbonate (PC), and polyarylate (PAR), acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, and the like.
[0016]
As a thermoplastic resin having an affinity for TPE to a polyurethane-based TPE and having a tensile modulus of 1 GPa or more, various polyamide resins represented by nylon 6, nylon 66, nylon 12, and the like, or ABS resin, AS resin, and the like. Highly polar polystyrene resin and the like can be given.
[0017]
The thermoplastic resin having an affinity for TPE and having a tensile modulus of 1 GPa or more in the present invention needs to have a tensile modulus of 1 GPa or more. If necessary, a reinforcing material can be added to further increase the elastic modulus.
Examples of the reinforcing material include glass fiber, carbon fiber, ceramic fiber, various whiskers, fibrous inorganic reinforcing materials such as acicular wollastonite, and powders such as silica, alumina, talc, kaolin, quartz, powdery glass, mica, and graphite. Inorganic reinforcing material. These reinforcing materials can be used after being surface-treated with a silane coupling agent or the like in order to enhance the adhesiveness with the thermoplastic resin.
[0018]
The TPE and the thermoplastic resin used in the present invention include a heat stabilizer, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a crystal nucleating agent, a lubricant, Molding agents, pigments, dyes and the like can also be added and blended.
[0019]
In the present invention, a method for producing a composite molded body of TPE and metal is extremely important.
First, it is necessary to cover part or all of the metal with a thermoplastic resin compatible with TPE. This thermoplastic resin has high strength and rigidity, and a metal component is tightened by a shrinkage force during molding to obtain a bonding force. The molding method for coating the thermoplastic resin is generally insert molding by injection molding, but is not necessarily limited thereto. Although the thickness of the thermoplastic resin to be coated varies depending on the parts to be manufactured, the thickness is generally about 1 mm or more. Most importantly, it is necessary that the coated thermoplastic resin and metal be integrated so that they do not peel or move even under severe use conditions. Therefore, it is effective to make cuts or projections in the metal parts. Further, depending on the use conditions, it is necessary to strengthen the thermoplastic resin with glass fiber or the like, and to increase the bonding strength to the metal with the thermoplastic resin having further increased strength and rigidity.
[0020]
In addition, in the case of small metal parts such as washers, in order to enhance the adhesion to TPE, not only the surroundings of the metal parts are covered with thermoplastic resin but also protrusions such as "collars" are made to make contact with TPE. The area is increased and the adhesive strength can be improved.
[0021]
Next, the metal component covered with the thermoplastic resin is bonded to the TPE by insert molding or the like. Since the surface of the metal component is coated with a thermoplastic resin having excellent compatibility with TPE, a composite molded body in which the metal component and TPE are firmly joined together can be obtained. At the interface between the rigid metal part and the flexible and flexible TPE, there is a thermoplastic resin that has a good affinity with TPE, and this thermoplastic resin tightens the metal part due to its rigidity. Even if stress is concentrated on the metal interface, a composite molded body of metal and TPE having extremely excellent bonding strength can be manufactured without peeling or moving.
[0022]
The composite molded body of TPE and metal in the present invention has a high rigidity thermoplastic resin having excellent affinity with TPE at the interface between the two to reduce stress concentration at the interface generated under severe use conditions. It is possible to produce a composite molded article of TPE and metal having excellent durability by being dispersed with a high thermoplastic resin.
[0023]
【Example】
Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
[0024]
(Method of measuring tensile modulus)
The stress-strain curve of the thermoplastic resin was measured under the following conditions, and the tensile modulus was calculated from the initial slope.
Equipment name: Tensilon UTM-III manufactured by Toyo Seiki
Measurement temperature and humidity: 23 ° C, 50% RH
Pulling speed: 500 mm / min Sample shape: Dumbbell-shaped No. 3 (thickness: 1 mm)
[0025]
(Example 1)
There is a joint part for mounting at the lower two places of a cylindrical cylinder with an inner diameter of about 65 mmφ × outer diameter of about 75 mmφ × height of 25 mm, which is a part of a car dust cover, and a metal washer is joined to the joint part and integrated Parts. This dust cover component has a cylindrical main body made of an olefin-based thermoplastic elastomer, and is a composite molded body of an olefin-based thermoplastic elastomer and a metal washer.
[0026]
As the olefin-based thermoplastic elastomer, "Surlink 3140" (manufactured by DSM, hardness is 40 A in JIS-A hardness) was used. The metal washer was made of steel (S-50C). As the thermoplastic resin having an affinity for the olefin-based thermoplastic elastomer and having a tensile modulus of 1 GPa or more, a polypropylene resin (Sumitomo Chemical Co., Ltd., Sumitomo Noblen W101) reinforced with glass fibers was used. Surlink 3140 is a TPE composed of a hard component polypropylene and a soft component EPDM. Since the hard component of the Surlink 3140 and the thermoplastic resin are the same polypropylene, they have extremely excellent affinity. Although the tensile modulus of the PP resin was 1.8 GPa, in order to further increase the rigidity, 10% by weight of glass fiber (3298 manufactured by PPG) was blended to obtain glass fiber reinforced PP. The tensile modulus of the glass fiber reinforced PP was 3.8 GPa.
[0027]
On the other hand, as shown in FIG. 1, four cuts were made in the outer peripheral portion of the metal washer to improve the bondability with the glass fiber reinforced PP. Next, as shown in the lower part of FIG. 1, the outer periphery of the metal washer is coated with glass fiber reinforced PP to a thickness of about 1 mm, and at the same time, the outer periphery of the metal washer is about 15 mm wide and about 4 mm high at a 45 ° angle. A single "brim" -shaped projection was made to improve the adhesiveness with the surlink 3140.
The molding was performed by insert molding under molding conditions at a cylinder temperature of 200 ° C.
Next, insert molding was performed with a metal washer coated with glass fiber reinforced PP and Surlink 3140 to produce a composite molded body. The molding conditions at this time were a cylinder temperature of 230 ° C. There were no burrs at the metal washer portion, and the moldability was extremely good, and an excellent composite molded article was obtained.
[0028]
This composite molded product was confirmed to be a composite molded product having extremely excellent bonding properties without peeling or loosening of a bonded portion even in a cooling / heating cycle test at −30 ° C. to + 100 ° C. Further, even when a repeated bending deformation test was performed at the interface between the cylindrical portion of the dust cover and the bottom surface where the metal washer was inserted, no peeling of the metal washer component was observed.
As a result, the moldability was good, and an excellent composite molded article was obtained.
[0029]
【The invention's effect】
The composite molded article of the thermoplastic elastomer and metal of the present invention has an extremely excellent joint, and the joint does not peel or loose even in a severe environment. It is preferably used in the application field of a composite product comprising a flexible thermoplastic elastomer and a metal. For example, it is used for automobile parts such as dust cover parts and air duct parts, electric tool parts, various electric parts and industrial parts, but is not limited thereto.
Further, the thermoplastic elastomer is a recyclable material, and since the thermoplastic resin covering the metal component is physically bonded to the metal component, it is possible to separate the two by crushing. Therefore, this composite can be said to be an extremely environmentally friendly material.
[Brief description of the drawings]
FIG. 1 is a view showing one example (Example) of a composite molded article of the present invention.

Claims (3)

A composite molded article of a thermoplastic elastomer and a metal, which has affinity for the thermoplastic elastomer and has a tensile modulus of 1 GPa or more, and is formed by coating a part or the whole of the metal with a thermoplastic resin. A composite molded article of a thermoplastic elastomer and a metal having excellent bonding strength, which is obtained by composite molding the metal coated with a thermoplastic resin and a thermoplastic elastomer. The composite molded article of thermoplastic elastomer and metal having excellent bonding properties according to claim 1, wherein the thermoplastic elastomer is an olefin-based thermoplastic elastomer, and the thermoplastic resin is a polyolefin-based resin. The composite molded article of a thermoplastic elastomer and a metal having excellent bonding properties according to claim 1, wherein the thermoplastic elastomer is an olefin-based thermoplastic elastomer, and the thermoplastic resin is a polypropylene resin.

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