JP2000246759A - Manufacture of automotive component made of resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for manufacturing a recyclable automotive component made of resin for utilizing not only a sense of softness of a thermoplastic elastomer but also a sense of a repulsion elasticity and integrally molding a skin material. SOLUTION: A preshaped olefin sheet-like skin material is previously set solely or additionally with a core material in a core mold in a cavity mold, the cavity mold and the core mold are closed. Then, a molten resin of a thermoplastic elastomer(TPE) obtained by kneading master batch or powder-like thermally expansible microcapsule obtained by machining the microcapsule in a pellet-like state is injection molded in a cavity between an olefin sheet-like skin material or a sheet-like skin material and a core material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a recycling method that utilizes not only the softness of a thermoplastic elastomer but also the resilience of a thermoplastic elastomer and integrally forms a skin material (a conventional product is provided and brought before). In particular, the present invention relates to a method for manufacturing a resin-made automobile component, particularly, a method in which thermally expandable microcapsules are once pelletized to form a master batch, or powdery thermally expandable microcapsules are mixed with thermoplastic elastomer (TPE) pellets. Injection molding of automobile parts with the material obtained, microcapsules expand and injection molding of automobile parts, and microcapsules expand to give the automobile parts fine hollow spheres. Provide parts.

[0002]

2. Description of the Related Art Conventionally, the following method has been employed as a method for enhancing the feel of interior parts of an automobile and obtaining a soft feeling on the surface. In this conventional method, a sheet-like skin material is formed into a desired shape by vacuum forming. The skin material thus shaped to some extent is set in the lower mold of the mold, and the core material separately molded by injection molding is set in the upper mold. Next, after closing the upper and lower molds, a urethane raw material is injected between the two, and foamed to integrate the base material and the core material. By doing so, it is possible to obtain an interior part for an automobile having a feeling and a soft feeling integrally formed with the skin material.

[0003] As the material of the core material, PP (polypropylene) which is inexpensive and easy to mold, and EPR is used.
For example, PP with a filler having improved strength, rigidity and impact resistance by adding a filler such as (ethylene / propylene / rubber) or talc, and modified PPE (polyphenylene ether) having high heat resistance are used. Generally, a filler-filled PP having a low material cost is often used.

[0004] The above-mentioned skin material which is directly exposed to the occupant's sight and tactile sensation is required to have the following performance. (1) Anti-glare properties that suppress sunlight reflection (2) Weather resistance that prevents discoloration and property deterioration due to ultraviolet rays (3) Shock absorption properties that ensure safety in the event of impact (4) Good appearance and feel

As a material satisfying the above required performance,
Most commonly, a semi-rigid P with a textured surface
VC (polyvinyl chloride) / ABS sheet or soft P
VC compacts are used.

[0006] A polyurethane foam is used as a cushion material.

On the other hand, a method for obtaining an injection-molded product by using a heat-expandable microcapsule is disclosed in Japanese Patent Application Laid-Open No. 9-234.
No. 758. The gist is that injection molding is performed using a polymer material that can be injection-molded and thermoplastic resin heat-expandable microspheres (or a pre-expanded product thereof), so that microsphere balloons are formed in a matrix made of the polymer material. This is a method for producing a foamed injection molded article three-dimensionally and uniformly dispersed.

That is, a method of manufacturing a foamed injection molded article in which thermoplastic resin heat-expandable microspheres (or a pre-expanded product thereof) are three-dimensionally and uniformly dispersed in a matrix made of a polymer material is disclosed. It merely describes general usage and does not describe how it was used to achieve any particular technical advantage.
Further, as for the method for obtaining the rebound resilience required for an automobile part aimed at by the present invention, it is merely described that various general thermoplastic elastomers are used. In particular, there is no mention of how to use this injection molding method from the viewpoint of recycling required for recent automotive parts.

[0009]

(1) Recycle (cross-linked) urethane that has been reactively foamed and cross-linked because urethane is used as the foam and that is injected and foamed.
At present, it is difficult to do so and it has to be treated as industrial waste. (2) The core material is made of PP with filler, the foam is urethane, the skin is PVC / ABS or a soft PVC molded body. Since it is a three-material composition and is integrally molded, it cannot be recycled and must be treated as industrial waste. Is gone. (3) Since PVC is used for the skin material, recycling is not possible, and chlorine-based gas is generated at the time of incineration, which is not preferable in the global environment.

[0010]

In order to solve the above-mentioned problems, the present invention provides an olefin-based sheet-like skin material preliminarily formed in a mold mold alone or in addition to the core material into a core mold. , The mold mold and the core mold are closed, and a master batch obtained by processing the heat-expandable microcapsules into pellets in advance or a thermoplastic elastomer (TP) obtained by kneading powdered heat-expandable microcapsules is set.
E) Injecting the molten resin into an olefin-based sheet-like skin material or a cavity between the sheet-like skin material and the core material to form an automobile part, thereby enabling a resin-made automobile part to be recycled. Is provided.

That is, in the first invention, after the preformed olefin-based sheet-like skin material 2 is set in the mold, the mold and the core are closed, and then the molded resin material is heated in advance. A master batch obtained by processing expandable microcapsules into pellets or a thermoplastic elastomer (TPE) obtained by kneading powdery heat-expandable microcapsules is prepared, and the heat-expandable microcapsules are prepared in a cylinder of an injection molding machine. The expansion of the gas contained in the capsule is almost completed, and the molten resin of the thermoplastic elastomer (TPE) including the expanded hollow sphere is injected into the cavity between the olefin-based sheet-like skin material 2 and the thermoplastic resin. Thermoplastic elastomer molded integrally with skin material 2 such that fine hollow spheres are uniformly dispersed in molded article 1 of elastomer (TPE) A method for producing a resin-made automobile parts, characterized in that to obtain a molded product 3 of (TPE).

Further, the second invention is to set a preformed olefin-based sheet-like skin material 2 in a mold, and to insert a filler such as EPR (ethylene propylene rubber) or talc in a core mold. After setting the core material 4 formed by the added PP (polypropylene), the mold mold and the core mold are closed, and then, as a molding resin material, a masterbatch or powdered form in which the thermally expandable microcapsules are previously processed into pellets A thermoplastic elastomer (TPE) prepared by kneading the thermally expandable microcapsules of the above is prepared, and in a cylinder of an injection molding machine, the expansion of the gas contained in the thermally expandable microcapsules is substantially completed,
Thermoplastic elastomer containing expanded hollow spheres (TP
E) The molten resin is injected into the cavity between the olefin-based sheet-like skin material 2 and the core material 4 to uniformly disperse the fine hollow spheres in the molded article 1 of the thermoplastic elastomer (TPE). The thermoplastic elastomer (TP) obtained by integrally molding the olefin-based core material 4 and the skin material 2 in the above manner
This is a method for producing a resin-made automobile part, which comprises obtaining the molded article 5 of E).

[0013] In a third aspect of the present invention, a master batch is provided.
After mixing the low-melting polyethylene and the heat-expandable microcapsules, they are supplied to an extruder, melt-kneaded, extruded and pelletized at the same time. Rate 50
3. The method for producing a resin-made automobile part according to claim 1, wherein a masterbatch having a weight of not more than part by weight is kneaded with a thermoplastic elastomer (TPE) and injection molded to obtain a molded product.

In a fourth aspect of the present invention, the masterbatch has a hard segment of 50 to 95 parts by weight of an olefinic thermoplastic elastomer (TPE) made of polypropylene and a soft segment made of EPDM (ethylene / propylene rubber). After mixing 5 to 50 parts by weight of the capsule, the mixture is supplied to an extruder, melt-kneaded and extruded, and at the same time, the master batch formed into a pellet is kneaded with a thermoplastic elastomer (TPE) and injection molded to obtain a molded product. A method for manufacturing a resin-made automobile component according to claim 1 or 2.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation and effects of the present invention will be described based on embodiments of the present invention. (1) The present invention is composed of an olefin-based skin material, a thermoplastic elastomer containing a heat-expandable microcapsule, and a PP-based core material. Is recyclable. Note that the core material is appropriately used depending on the applied part. Therefore, it is not always necessary depending on the use site.

(2) Since the foam giving the rebound resilience is a thermoplastic material and is formed by injection molding with good productivity, the productivity is good.

(3) The thermally expandable microcapsules are uniformly dispersed in the thermoplastic elastomer and have the following features.

Thermoplastic elastomers have been increasingly applied as materials to replace vulcanized rubber, and have characteristics of good moldability and rubber-like elasticity. However, an elastomer alone could not provide a feeling of elasticity comparable to that of urethane which has been conventionally used as an elastic material for interior parts of automobiles. In order to obtain a feeling of elasticity comparable to that of urethane, it is necessary for the material to have a certain amount of closed or open cells. It is not possible with an elastomer alone to impart elasticity to a part of the automobile parts, which is an object of the present invention, that is frequently touched by an occupant. The elastomer alone can exhibit the elasticity of rubber, but cannot exhibit the resilience of urethane. Accordingly, in the present invention, by uniformly dispersing microballoons in a thermoplastic elastomer, deformation of the balloon with respect to external stress, that is, compression of air inside the balloon occurs, so that softness that cannot be obtained with an elastomer alone can be obtained. A feeling and elasticity can be obtained. Usually, the specific gravity of the olefin-based thermoplastic elastomer having a specific gravity of 0.9 to 1.0 is 0.1 because the heat-expandable microcapsules are uniformly dispersed in the resin.
It becomes 2 to 0.8, so that a great reduction in weight can be achieved.

When imparting elasticity, low-melt PE, which is a binder component of the masterbatch, affects the elasticity of the material. That is, when a masterbatch is formed, as the amount of the binder increases, the productivity improves, but from the viewpoint of rebound resilience, the component of the low-melting PE as the binder is 50%.
If the amount is more than 10 parts by weight, the rebound resilience will be reduced.
５０50 parts by weight.

When making a masterbatch for the same reason,
If the binder is the same thermoplastic elastomer, it is the same material as the molded article main body, and does not reduce the elasticity of the thermoplastic elastomer. For this reason, it is an effective method to use a thermoplastic elastomer as the binder in forming a master batch.

As will be understood from the above description, the present invention relates to a method in which the thermally expandable microcapsules are pelletized into a masterbatch or the powdery thermally expandable microcapsules are combined with thermoplastic elastomer (TPE) pellets. The present invention relates to a method of manufacturing an automobile part in which an automobile part is injection-molded from a mixed material so that the microcapsules expand to present fine hollow spheres in the automobile part. It is an integral part of the skin material while taking advantage of the elasticity, and because it is lightweight, it has a very large practical effect, such as improved quality, improved productivity, and recyclability without disassembly. is there.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a resin-made automobile component showing one embodiment of the present invention.

FIG. 2 is a sectional view of a resin-made automobile component showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Molded article of thermoplastic elastomer in which fine hollow spheres are uniformly dispersed inside 2 Sheet-shaped skin material 3 Molded article 4 Core material 5 Molded article

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B29K 623: 00 B29L 31:30 F term (reference) 3D023 BA01 BB01 BC00 BD00 BE04 BE06 BE22 BE31 4F202 AA45 AB20 AD05A AD08 AD35 AG03 AG20 AH25 AH26 CA11 CB01 CB13 CB20 4F206 AA45 AB20 AD05A AD08 AD35 AG03 AG20 AH25 AH26 JA07 JB13 JB20 JF02 JF13 JF21 JF23 JF51 JL02 JM04

Claims (4)

[Claims] 1. An olefin-based sheet-like skin material (2) preliminarily shaped is set in a mold, and then the mold and the core are closed. A thermoplastic elastomer (TPE) prepared by kneading a masterbatch or a powdery heat-expandable microcapsule prepared by processing into a pellet form is contained in the heat-expandable microcapsule in a cylinder of an injection molding machine. The expansion of the gas is almost completed, and the molten resin of the thermoplastic elastomer (TPE) including the expanded hollow spheres is injected into the cavity between the olefin-based sheet-like skin material (2) and the thermoplastic elastomer ( Thermoplastic elastomer (T) formed integrally with a skin material (2) so as to uniformly disperse fine hollow spheres in a molded product (1) of TPE). E)
A method for producing a resin-made automobile part, characterized in that a molded article (3) is obtained. 2. A preform-molded olefin sheet-like skin material (2) is set in a mold mold, and PP (ethylene, propylene, rubber) or filler such as talc is added to a core mold (PP). After setting the core material (4) molded from polypropylene), the mold mold and the core mold are closed, and then, as a molding resin material, a masterbatch or powdered heat-treated pre-processed thermally expandable microcapsules are pelletized. A thermoplastic elastomer (TPE) prepared by kneading expandable microcapsules is prepared, and in a cylinder of an injection molding machine, expansion of a gas contained in the heat expandable microcapsules is almost completed, and the expanded hollow sphere is formed. The molten resin of thermoplastic elastomer (TPE) containing olefin is filled with a cap between the olefin-based sheet-like skin material (2) and the core material (4). The olefin core material (4) and the skin material (2) are integrally formed by injecting into the tee and uniformly dispersing the fine hollow spheres in the thermoplastic elastomer (TPE) molded product (1). A method for producing a resin-made automobile part, characterized in that a molded article (5) of a thermoplastic elastomer (TPE) is obtained. 3. The masterbatch is prepared by mixing low-melting polyethylene and heat-expandable microcapsules and then feeding the extruder to melt-knead and extrude the material into pellets at the same time as the heat-expandable microcapsules. 3. The method according to claim 1, wherein a masterbatch having a low melting PE content of 50 parts by weight or less is kneaded with a thermoplastic elastomer (TPE) and injection molded to obtain a molded product. Of manufacturing resin-made automotive parts. 4. 50 to 95 parts by weight of an olefin-based thermoplastic elastomer (TPE) having a hard segment of polypropylene and a soft segment of EPDM (ethylene / propylene rubber) in a masterbatch and 5 to 50 parts by weight of thermally expandable microcapsules. 2. A mixture is supplied to an extruder, melt-kneaded and extruded, and at the same time, a pelletized master batch is kneaded with a thermoplastic elastomer (TPE) and injection molded to obtain a molded product. A method for producing a resin-made automobile component according to claim 2.