Molding for automobile and its manufacturing method

A molding for automobile includes a molding body (1, 25) comprising a vertical supporting portion (2, 26) made of a synthetic resin, a decorative portion (3, 27) made from synthetic resin and integrally connected to the vertical supporting portion (2, 26), and a metal piece (5, 28) embedded in the vertical supporting portion (2, 26) and decorative portion (3, 27), wherein the metal piece (5, 28) is rigidly and integrally joined to the molding body (1, 25) via an adhesive resin layer (6, 29) of a polar group containing thermoplastic resin composition. A manufacturing method for the molding for an automobile comprises the steps of feeding a metal piece (5, 28) to a molding die (17, 21, 22), fusibly bonding an adhesive resin layer (6, 29) of a polar group containing thermoplastic resin composition to the metal piece (5, 28) in the molding die (17, 21), fusibly bonding a synthetic resin of the molding body (1, 25) to the adhesive resin layer (6, 29) laminated on and bonded to the metal piece (5, 28) in the molding die (17, 22), and forming a molding by integrally joining the metal piece (5, 28) to the molding body (1, 25) via the adhesive resin layer (6, 29).

FIELD OF THE INVENTION
 The present invention relates to a molding for an automobile and its
 manufacturing method. Particularly, the molding is a window molding, an
 outer molding, an inner molding, or a roof molding of weatherstrip to be
 mounted on vehicles like automobiles, wherein a metal piece is embedded in
 a molding body made of a synthetic resin and is joined rigidly and
 integrally to the synthetic resin of the molding body.
 DESCRIPTION OF PRIOR ART
 The known moldings of this kind which have an embedded metal piece are
 commonly formed so as to integrally join a molding body made of a
 polyvinyl chloride to the metal piece by using an adhesive to adhere the
 metal piece to the molding body.
 In the known molding as described above, it is difficult to uniformly apply
 the adhesive onto the periphery of the metal piece, and it is required to
 set up a separate manufacturing line for performing a drying process to
 volatilize a solvent contained in the adhesive. Thus, the production
 efficiency is reduced considerably depending on the time required for the
 drying process, and an unpleasant odor caused by the volatilization of the
 adhesive solvent in the drying process results in a harmful environment in
 the manufacturing factory, and also results in air pollution. Thus, from
 an environmental perspective it is desirable that the adhesive with
 solvent be eliminated.
 SUMMARY OF THE INVENTION
 An object of the present invention is, in order to resolve the problems of
 the prior art as described above, to provide a molding for an automobile
 and its manufacturing method, wherein a metal piece to be embedded in a
 molding body made of a synthetic resin is joined integrally and rigidly to
 the molding body without using any adhesive containing a solvent. This is
 accomplished by employing a polar group containing thermoplastic resin
 composition that is capable of bonding efficiently to a metal while the
 resin is in a molten condition.
 Another object of the present invention is to provide a molding for an
 automobile and its manufacturing method, wherein the molding body is made
 of an olefin based resin or a styrene based resin, which does not pollute
 the environment as does a dioxin or the like, and which contributes to
 lessening the automobile's weight because of its low specific gravity. The
 olefin based resin or styrene based resin is fusibly joined to a polar
 group containing thermoplastic resin composition that is fusibly bonded on
 the periphery of a metal piece.
 Still another object of the present invention is to provide a molding for
 an automobile and its manufacturing method, wherein a polar group
 containing thermoplastic resin composition is fusibly bonded to the
 periphery of a metal piece except for a portion thereof, and a synthetic
 resin of the molding body is extruded onto the polar group containing
 thermoplastic resin composition bonded to the metal piece, whereby the
 metal piece is exposed along the longitudinal direction of the molding
 body and provides a decorative effect.
 A molding for an automobile according to the present invention includes a
 molding body comprising a vertical support made of a synthetic resin, and
 a decorative section made of a synthetic resin formed integrally with the
 vertical support, along with a metal piece embedded in the vertical
 support and the decorative section, wherein the metal piece is joined
 integrally to the molding body by use of a polar group containing
 thermoplastic resin composition. The molding body according to the present
 invention includes a longitudinal aperture in the decorative section to
 outwardly expose the metal piece.
 A manufacturing method for the molding for an automobile comprises the
 steps of: feeding continuously a metal piece to a molding die; fusibly
 bonding an adhesive resin layer of a polar group containing thermoplastic
 resin composition, which has been poured into a first extrusion molding
 machine, to the metal piece in the molding die; fusibly joining an olefin
 based resin or styrene based resin which has been poured into a second
 extrusion molding machine, to the adhesive resin layer laminated on and
 bonded to the metal piece; continuously forming a molding having the metal
 piece bonded integrally and rigidly to the olefin based resin or styrene
 based resin via the adhesive resin layer; feeding the molding by a
 transporting device into a cooling water pool to vulcanize or cure the
 resin; and cutting the molding to a given dimension by using a cutter. The
 adhesive layer of the polar group containing thermoplastic resin
 composition is bonded onto the metal piece, and the resin or the molding
 is joined to the adhesive layer such that a portion of the metal piece is
 outwardly exposed.
 A modification of the manufacturing method for the molding for an
 automobile according to the present invention comprises the steps of:
 feeding a metal piece continuously to a first molding die and a second
 molding die; fusibly bonding a polar group containing thermoplastic resin
 composition, which has been poured into a first extrusion molding machine,
 to the metal piece in the first molding die; fusibly joining an olefin
 based resin or styrene based resin, which has been poured into a second
 extrusion molding machine, to the adhesive resin layer laminated on and
 bonded to the metal piece in the second molding die; continuously forming
 a molding having the metal piece joined integrally via the adhesive layer;
 feeding the molding into a cooling water pool by a transporting device to
 vulcanize or cure the resin; and cutting the molding to a given dimension
 by operating a cutter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 FIG. 1 shows a molding body 1 mounted on the upper end of a door panel 10
 for guiding and supporting a window glass 12, which moves upwardly and
 downwardly in a door 11 of a vehicle like an automobile. Another molding
 body 25 is mounted between the outer circumference of a window glass 31
 and a body panel 32.
 The molding body 1 is a molding body for the inner molding and the outer
 molding for a weatherstrip provided respectively on the inner side and
 outer side of the glass window 12 as shown in FIG. 2. Each molding body 1
 includes a vertical supporting portion 2 made of a synthetic resin, a
 decorative portion 3 also made of a synthetic resin connected at an
 inclined angle relative to the vertical supporting portion, and a metal
 piece 5 embedded in both of the supporting portion 2 and the decorative
 portion 3. The metal piece 5 is joined integrally and rigidly to the
 molding body 1 made of synthetic resin via an adhesive resin layer 6
 consisting of a polar group containing thermoplastic resin composition
 capable of bonding efficiently to metals in a molten condition.
 The molding body 1 of the inner molding for the weatherstrip as shown in
 FIG. 3 includes a vertical supporting portion 2 made of a synthetic resin
 which is located between the window glass 12 and the inner door panel 10,
 a decorative portion 3 made of a synthetic resin which is located on the
 interior side of the vehicle 13 far away from the window glass 12 and is
 connected at an inclined angle to the vertical supporting portion 2, and a
 metal piece 5 embedded inside the supporting portion 2 and decorative
 portion 3. The metal piece 5 is joined, integrally to the molding body
 made of the synthetic resin by fusibly bonding an adhesive resin layer, of
 a polar group containing thermoplastic resin composition capable of
 bonding efficiently to metal over the whole periphery of the metal piece
 5.
 The synthetic resin for the molding body 1 consists of an olefin based
 resin such as a polypropylene resin, an olefin based thermoplastic
 elastomer resin composition, a styrene based thermoplastic elastomer resin
 composition, etc. The metal piece 5 is stainless steel, iron, steel,
 aluminum, etc.
 The polar group containing thermoplastic resin composition used for the
 adhesive resin layer 6 is an ethylene methacrylic acid copolymer or a
 metal salt thereof, compositions including an ethylene methacrylic acid
 copolymer or a metal salt thereof, a maleic anhydride, an acid
 denaturation of carboxylic acid, a denatured olefin based resin
 composition, or a denatured styrene based resin composition owing to epoxy
 denaturation.
 A draining foot 8 is mounted to the vertical supporting portion 2 of the
 molding body 1 to press against the glass window 12 as shown in FIG. 2 to
 FIG. 4. The draining foot 8 is made of a flexible olefin based
 thermoplastic elastomer composition or a flexible styrene based
 thermoplastic elastomer composition. The draining foot 8 is provided with
 a pressure laminate layer 9 in contact with the glass window 12. The
 pressure laminate layer 9 is made of a implanted flocculus or pile of
 nylon, etc., having low frictional resistance and excellent wear
 resistance, and a urethane coating, or a rough surface with a plurality of
 protrusions formed from a mixture of two sorts of polyethylene resins of
 different melting viscosities.
 The molding body 1 of an outer molding for weatherstrip shown in FIG. 4
 includes a vertical supporting portion 2 made of an olefin based resin or
 a styrene based resin which is located between the glass window 12 and the
 outer door panel 10, a decorative portion 3 made of an olefin based resin
 or a styrene based resin which is connected at an inclined angle relative
 to the vertical supporting portion 2 and is located outside of the outer
 door panel 10, and a metal piece 5 embedded in both of the vertical
 supporting portion 2 and decorative portion 3. The metal piece 5 is joined
 integrally to the synthetic resin of the molding body 1 via an adhesive
 resin layer 6 consisting of a polar group containing thermoplastic resin
 composition capable of bonding efficiently to metals. The decorative
 portion 3 of the molding body 1 is provided on its front surface with an
 aperture 7, through which the metal piece 5 is exposed and not covered
 with the adhesive resin layer 6 as well as the synthetic resin of the
 molding body 1, whereby a decorative effect is enhanced.
 FIG. 5 shows a molding body 25 mounted between a window glass 31 and body
 panel 32 of an automobile, wherein the molding body 25 includes a vertical
 supporting portion 26 made of an olefin based resin or a styrene based
 resin, a decorative portion 27 made of an olefin based resin on a styrene
 based resin and connected vertically to the vertical supporting portion
 26, and a metal piece 28 embedded in both of the supporting portion 26 and
 decorative portion 27 and integrally joined to the synthetic resin of the
 molding body 25 via an adhesive resin layer 29 of a polar group containing
 thermoplastic resin composition capable of bonding efficiently to metals.
 The decorative portion 27 of the molding body 25 is provided on its front
 surface with an aperture 30, through which the metal piece 28 is exposed
 and not covered with the adhesive resin layer 29 as well as the synthetic
 resin of the molding body 25, whereby a decorative effect is enhanced. The
 reference numeral 33 indicates an adhesive to seal the molding body 25 in
 a gap between the window glass 31 and the body panel 32.
 FIG. 6 shows a first embodiment of the manufacturing method of the molding
 according to the present invention. A first extrusion molding machine 15
 is connected through a flow pipe 14 to a molding die 17. A second
 extrusion molding machine 16 is also connected through another flow pipe
 14 to the molding die 17. An adhesive resin of a polar group containing
 thermoplastic resin composition is poured into and melted in the first
 extrusion molding machine 15, and similarly, an olefin based resin or a
 styrene based resin is poured into and melted in the second extrusion
 molding machine 16. When a metal piece 5 is fed continuously into the
 molding die 17, the melted adhesive resin poured into the first extrusion
 molding machine 15 is supplied through the flow pipe 14 to the molding die
 17 and fuslsibly bonded to the periphery of the continuously fed metal
 piece 5 in the molding die 17. Then the melted olefin based resin or
 styrene based resin of the molding body poured into the second extrusion
 molding machine 16 is supplied through the flow pipe 14 to the molding die
 17 and fisibly joined to the adhesive resin layer 6 laminated on and
 bonded to the periphery of the metal piece 5. Consequently, a molding is
 formed by integrally joining the metal piece via the adhesive resin layer
 to the molding body. Then, the molding is fed by transporting device 19 to
 a cooling water pool 18 to vulcanize or cure the molding, and is cut to a
 given dimension by a cutter 20 to form the desired molding. The molding
 die 17 is designed in such a manner that the melted adhesive resin layer
 and the melted synthetic resin of the molding body can be coated over the
 whole periphery of the metal piece 5, and can also be coated partially
 onto the periphery of the metal piece 5 so that an aperture 7 is formed in
 the molding body 1.
 FIG. 7 shows a second embodiment of the manufacturing process for the
 molding according to the present invention. A first extrusion molding
 machine 15 is connected through a flow pipe 14 to a first molding die 21,
 and a second extrusion molding machine 16 is connected through another
 flow pipe 14 to a second molding die 22. An adhesive resin of a polar
 group containing thermoplastic resin composition is poured into and melted
 in the first extrusion molding machine 15, and similarly an olefin based
 resin or styrene based resin of the molding body is poured into and melted
 in the second extrusion molding machine 16. Upon feeding a continuous
 metal piece 5 to the first molding die 21, the adhesive resin poured into
 the extrusion molding machine 15 is fed through the flow pipe 14 to the
 first molding die 21 and is fusibly bonded to the periphery of the metal
 piece 5 in the first molding die 21. Then the metal piece 5 laminated with
 the adhesive resin layer 6 is fed into the second molding die 22, and the
 olefin based resin or styrene based resin of the molding poured into the
 second extrusion molding machine 16 is fed through the flow pipe 14 to the
 second molding die 22 and is fusibly bonded to the adhesive resin layer 6
 laminated on and bonded to the periphery of the metal piece 5.
 Consequently the synthetic resin of the molding body is integrally joined
 via the adhesive resin layer 6 to the metal piece 5 to form a continuous
 molding. The continuous molding is then fed by a transporting device 19 to
 a cooling water pool 18 to vulcanize or cure the molding, and is cut by a
 cutter 20 to a given dimension to form a molding. The first molding die 21
 is designed such that the melted adhesive resin can be coated over the
 whole or a portion of the periphery of the metal piece 5, and the second
 molding die 22 is likewise designed so that the melted synthetic resin of
 the molding body can be coated over the whole or a portion of the
 periphery of the adhesive resin layer 6 laminated on and bonded to the
 metal piece 5.
 FIG. 8 shows a modification of the manufacturing process for the molding
 shown in FIG. 7. In this modification, a roll forming device 23 is
 disposed between the first molding die 21 and the second molding die 22 to
 form a bending portion 24 on the metal piece 5 laminated with the adhesive
 resin layer 6.
 In the manufacturing process for the molding shown in FIG. 6 and FIG. 7,
 the roll forming device 23 can be disposed upstream of the molding die 17
 and the first molding die 21 to form the bending portion 24 on the metal
 piece 5 before the metal piece 5 is fed to the molding die 17 and the
 first molding die 21.
 FIGS. 9(a)-9(c) show a processing sequence for products in the
 manufacturing process for the molding, wherein FIG. 9 (a) shows a
 condition in which the adhesive resin layer 6 is fusibly bonded on the
 periphery of the metal piece 5, FIG. 9 (b) shows a condition in which a
 bending portion 24 is formed on the metal piece 5 laminated with the
 adhesive resin layer 6 by the roll forming device 23, and FIG. 9 (c) shows
 a condition in which the synthetic resin of the molding body is fusibly
 joined to the periphery of the adhesive resin layer 6 laminated on the
 metal piece 5.
 In the manufacturing method for the molding according to the present
 invention, the polar group containing thermoplastic resin composition of
 the adhesive resin layer 6 poured into the first extrusion machine 15 is
 heated at a temperature of 150 to 240.degree. C., and the olefin based
 resin or the styrene based resin poured into the second extrusion molding
 machine 16 is heated at a temperature of 160 to 240.degree. C. The molding
 can be formed in one molding die 17, or two molding dies 21, 22 by
 operating the two molding dies simultaneously.
 In the molding for an automobile and its manufacturing method according to
 this invention, the metal piece can be rigidly and integrally joined to
 the synthetic resin of the molding body by using the adhesive resin of the
 polar group containing thermoplastic resin composition without causing any
 hannful environment in the manufacturing factory, and without causing any
 atmospheric pollution The use of the olefin based resin or styrene based
 resin for the molding body can serve for lessening an automobile's weight,
 and allows for simple enhancement of a decorative effect of the molding.