JP2006321319A - Thermoplastic resinous core material, automobile weather strip, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resinous core material capable of having light weight and a good recycle property, facilitating molding, and showing sufficient installing strength; an automobile weather strip wherein the thermoplastic resinous core material is buried, and a manufacturing method thereof. <P>SOLUTION: The core material 10 with a U-shaped cross-section buried in rubber of the automobile weather strip 1 or a holding portion 3 made from a thermoplastic elastomer is manufactured by extruding crystalline thermoplastic resin into a band shape in an amorphous state, molding in a lightening shape such as a fish bone or a number sign shaped at the time of extruding or thereafter, and heating the core material 10 to a crystallizing temperature to crystalize after curving that so as to have the U-shaped cross section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a core material made of a thermoplastic resin, a weather strip for automobiles in which the core material is embedded, and a method for producing them.

  Conventionally, as shown in FIGS. 1 to 3, in an automotive weather strip 20, a weather strip body portion formed of rubber R or a thermoplastic elastomer T in order to securely and firmly attach to a vehicle body opening flange 51. In addition, a metal core material 30 embedded and integrally molded is often used. In addition, 52 is an interior material, 60 is a door, 21a is a claw part, and 23 is a lip piece.

  Such a weather strip 20 is formed by punching a strip-shaped metal flat plate into a hollow shape and processing the core material 30, and then coating the core material 30 with rubber R or thermoplastic elastomer T in an extrusion process. The holding part 21 with the part 21a, the seal part 22, and the lip piece 23 are formed and then vulcanized (in the case of the thermoplastic elastomer T, it is cooled). Finally, the holding portion 21 in which the core member 30 is embedded is bent into a U-shaped cross section.

On the other hand, in recent years, due to increasing awareness of environmental problems, attempts have been made to change the core material of automobile weather strips from metal to resin to improve weight reduction and recyclability (for example, Patent Document 1). reference).
JP 2004-306932 A

  However, when the core material of the weather strip for automobiles is made of resin, it is difficult to bend and mold it into a U-shaped cross section in a post-process after extrusion molding. When the core material is made of resin, a resin having a high melting point and a glass transition temperature equivalent resin transition temperature is inevitably selected in consideration of rigidity and heat resistance. For this reason, rubber R or thermoplastic elastomer T is used as the core material. This is because if the resin is molded into a U-shaped cross section after coating, it is necessary to apply high heat, and the heat causes deformation of the rubber R and the like.

  Therefore, as shown in FIG. 4, after the resin core material 40 is extruded into a U-shaped cross section, it is shaped like a grid shown in FIG. 5 (a) or a fishbone shape shown in FIG. 5 (b). At the same time as coating with rubber or thermoplastic elastomer in the subsequent extrusion process, a holding portion and a seal portion are formed, and a weather strip 20 as shown in FIG. 2 is formed.

  The resin core member 40 and the weather strip 20 thus formed have a new problem. The problem of the core material 40 is that it is difficult to process because it is processed into a hollow shape after being formed into a U-shaped cross section. Further, the problem with the weather strip 20 is that the resin core material 40 is extruded in advance in a U-shaped cross section, and the core material 40 is coated with the rubber R and the thermoplastic elastomer T by further extrusion molding. It is technically difficult for extrusion to set the interval between the holding portions 21 in which 40 is embedded, so that the interval D between the left and right claw portions 21a is increased as shown in FIG. The problem of lack of mounting retention occurs.

As a means for solving this problem, as shown in FIG. 7, a method is proposed in which the inside of the claw portion 21 a is formed by the outside extension portion of the covering portion having a U-shaped cross section and then pushed into the inside of the covering portion. (For example, refer to Patent Documents 2 to 5).
JP 2004-142716 A JP 2004-168019 A JP 2004-224322 A JP 2004-338688 A

  However, this means has a problem that it is difficult to process because it is necessary to process the core material 40 into a U-shaped section after forming the core material 40 into a U-shaped section, as in the above-described problem. Moreover, since the core member 40 and the inside of the claw portion 21a are not bonded, there is a problem that the mounting strength is insufficient.

  The present invention has been devised in view of these points, and is a lightweight thermoplastic resin core material that is excellent in recyclability, that can be easily molded, and that can exhibit sufficient mounting strength, and a weather strip for an automobile in which it is embedded. Furthermore, it is an object to provide a manufacturing method thereof.

  This will be described with reference to FIGS. The thermoplastic resin core material 10 according to claim 1 is a core material having a U-shaped cross section embedded in the holding portion 2 of the weather strip 1 for an automobile, and the core material 10 is a crystalline thermoplastic resin. The resin is extruded into a strip shape in an amorphous state, further bent into a U-shaped cross section, and then heated to a crystallization temperature to be crystallized.

  The thermoplastic resin core material according to claim 2 is characterized in that, in the invention according to claim 1, the glass transition temperature equivalent resin transition temperature of the crystalline thermoplastic resin is not less than room temperature. It is.

  The automobile weather strip 1 according to claim 3 is made by embedding a core material 10 made of a thermoplastic resin and having a U-shaped cross section in the holding portion 2, and the core material 10 is formed in the first extrusion molding step. The crystalline thermoplastic resin is extruded into a strip shape in an amorphous state, and the holding portion 2 is formed in a second extrusion process, after the core material 10 is coated with the rubber R or the thermoplastic elastomer T, The core material 10 is formed by being bent into a letter shape and then heated to the crystallization temperature and crystallized.

  The weather strip 1 for an automobile according to claim 4 is the invention according to claim 7, wherein the glass transition point equivalent resin transition temperature of the crystalline thermoplastic resin forming the core material 10 is not less than room temperature. It is a feature.

  Since the thermoplastic resin core material 10 according to claims 1 and 2 is made of resin, it is lighter than the metal core material 30 and is excellent in recyclability.

  Further, the core material 10 is formed by extruding a crystalline thermoplastic resin into a strip shape in an amorphous state, processing into a hollow shape at the time of the extrusion molding or after the extrusion molding, and then bending it into a U-shaped cross section. Therefore, it is easier to form compared to the case where it is processed into a hollow shape after being formed into a U-shaped cross section.

  Since the core material 10 is crystallized by heating to the crystallization temperature, it is excellent in rigidity and heat resistance, and can exhibit a stable and high mounting strength in any environment.

  The invention described in claim 2 uses the thermoplastic resin forming the core material 10 having a glass transition temperature equivalent resin transition temperature of room temperature or higher, and therefore deforms at room temperature during handling. There is nothing.

  In the automobile weather strip 1 according to claims 3 and 4, since the core material 10 embedded in the holding portion 2 is made of resin, it is lighter than the metal core material 30 and is excellent in recyclability.

  Further, in the first extrusion molding process, the core material 10 is formed by extruding a crystalline thermoplastic resin into a strip shape in an amorphous state, and processing into a hollow shape at the time of the extrusion molding or after the extrusion molding. Since it is bent into a letter shape, it is easier to mold compared to the case where it is processed into a hollow shape after being formed into a U-shaped section as in the prior art.

  In addition, since the core material 10 is formed by bending the core material 10 with the rubber R or the thermoplastic elastomer T and then bending into a U-shaped cross section in the second extrusion molding step, the spacing d between the holding portions 2 is sufficient. Can be set small. Thereby, sufficient mounting strength can be given.

  Further, since the core material 10 is crystallized by heating to the crystallization temperature, the core material 10 is excellent in rigidity and heat resistance, and exhibits stable and high mounting strength in any environment.

  In the invention according to claim 4, since the thermoplastic resin forming the core material 10 has a glass transition temperature equivalent resin transition temperature of room temperature or higher, it deforms at room temperature during handling. There is nothing.

  Embodiments of the thermoplastic resin core material according to the present invention are shown in FIGS. FIG. 8 shows a fishbone shape, and FIG. 9 shows a cross-beam shape. This core material 10 is manufactured by the method for manufacturing a thermoplastic core material according to the present invention.

  The core material 10 has a U-shaped cross section embedded in the holding part of an automotive weather strip including a holding part 2 with a claw part 2 a having a U-shaped cross section, a hollow seal part 3, and a lip piece 4. is there. This core material 10 is formed by extruding a crystalline thermoplastic resin into a strip shape in an amorphous state, then processing it into a hollow shape such as a fishbone shape or a cross-beam shape, and then bending it into a U-shaped cross section. is there. This bending is performed by heating the core material 10 to a glass transition temperature equivalent resin transition temperature or higher. Finally, it is heated to the crystallization temperature and crystallized.

  Since the core member 10 is made of resin, it is lighter than metal and has excellent recyclability. In addition, after being processed into a hollow shape in a belt-like state, it is bent into a U-shaped cross section, so that processing is easy. Furthermore, since it is heated to the crystallization temperature for crystallization, it has excellent rigidity and heat resistance, and exhibits stable and high mounting strength in any environment.

  In addition, since the thermoplastic resin core material 10 according to the present embodiment uses polyethylene terephthalate (PET) or polylactic acid (PLA) having a glass transition temperature equivalent resin transition temperature of room temperature or higher, the moldability is improved. Excellent. Use of polylactic acid (PLA) is also preferable in terms of environment.

  Incidentally, the melting point of polyethylene terephthalate (PET) is 260 ° C., the crystallization temperature is 133 ° C., the glass transition temperature equivalent resin transition temperature is 78 ° C., the melting point of polylactic acid (PLA) is 160 ° C., and the crystallization temperature is 120 ° C. The glass transition temperature equivalent resin transition temperature is 60 ° C. Therefore, in the former case, it is bent into a U-shaped section at about 80 to 120 ° C. and crystallized at 120 to 140 ° C., and in the latter case, it is bent at about 60 to 100 ° C. Crystallize at 130 ° C. At this time, if the temperature at the time of bending is too close to the crystallization temperature, crystallization proceeds quickly, so that it is difficult to bend, so care must be taken. Further, the temperature at which the resin is crystallized may be kept at 10 ° C. before or after the crystallization temperature because the crystallization speed is slowed if the temperature is too low or too high. Since these temperatures are slightly different depending on the grade, the molding and crystallization temperatures are also different accordingly.

  The thermoplastic resin forming the core material 10 is a crystalline resin other than polyethylene terephthalate (PET) or polylactic acid (PLA), and can form an amorphous belt-like sheet and bend. A material having a relatively low crystal acceleration that does not cause excessive crystallization during molding is suitable.

  In addition, a crystal nucleating agent and a crystallization accelerator can be added to these thermoplastic resins for the purpose of adjusting the crystallization speed. Also, other resins such as amorphous resin can be added as long as heat resistance can be imparted. Furthermore, in order to increase rigidity and heat resistance and reduce the linear expansion coefficient, reinforcing agents such as glass fiber, carbon fiber, talc and mica may be added, and generally used thermal stabilizers. Plasticizers, lubricants, colorants, antioxidants, and UV inhibitors can also be added.

  FIG. 10 shows an embodiment of an automotive weather strip 1 according to the present invention. The weather strip 1 is manufactured by the method for manufacturing a weather strip for automobiles according to the present invention.

  This automobile weather strip 1 is made by embedding a core material 10 made of a thermoplastic resin and having a U-shaped cross section in a holding section 2 having a U-shaped cross section. Note that a hollow seal portion 3 and a tongue-like lip portion 4 are integrally formed on the holding portion 2 by extrusion.

  The weather strip 1 is obtained by extruding a core material 10 in a first extrusion molding process in which a crystalline thermoplastic resin is formed into a strip shape in an amorphous state and processed into a hollow shape after the extrusion molding. Further, the holding part 2 is formed into a U-shaped cross section after the core material 10 is covered with the rubber R or the thermoplastic elastomer T in the second extrusion molding step. At this time, the seal portion 3 and the lip portion 4 are formed simultaneously. And the core material 10 is heated and crystallized to the crystallization temperature.

  The core material 10 can be bent into a U-shaped cross section by heat when the core material 10 is coated with the rubber R or the thermoplastic elastomer T, and the glass transition equivalent resin transition. It can also be performed by heating above the point temperature. Since the core material 10 in the amorphous state can be easily deformed and re-formed at a temperature equal to or higher than the glass transition temperature equivalent resin transition temperature, the bending to the U-shaped cross section can be easily performed.

  The automobile weather strip 1 is lightweight because the core material 10 embedded in the holding portion 2 is made of resin, and is excellent in recyclability. Further, the core material 10 is formed by extruding a crystalline thermoplastic resin into a strip shape in an amorphous state, processing into a hollow shape at the time of the extrusion molding or after the extrusion molding, and then bending it into a U-shaped cross section. Therefore, compared with the case where it forms in the shape of a hollow after forming in U-shaped cross section, shaping | molding is easy.

  In addition, since the core material 10 is formed by bending the core material 10 with the rubber R or the thermoplastic elastomer T and then bending into a U-shaped cross section in the second extrusion molding step, the spacing d between the holding portions 2 is sufficient. Can be set small. Thereby, sufficient mounting strength can be given.

  Further, since the core material 10 is crystallized by heating to the crystallization temperature, the core material 10 is excellent in rigidity and heat resistance, and exhibits stable and high mounting strength in all situations.

  The thermoplastic resin forming the core material 10 uses polyethylene terephthalate (PET) or polylactic acid (PLA) having a glass transition temperature equivalent resin transition temperature of room temperature or higher. Thereby, it does not deform | transform easily with temperature, and it is excellent also in a moldability. In addition, since polylactic acid (PLA) is obtained by polymerizing lactic acid obtained from a plant, it is excellent in terms of environment.

  Using a first extruder, glass fiber reinforced polyethylene terephthalate (RYNITE 415HP, manufactured by DuPont Co., Ltd.) was extruded and quenched, and formed into a strip shape having a width of 40 mm and a thickness of 1 mm in an amorphous state. Thereafter, it was processed into a fishbone shape to obtain a resin core material as shown in FIG. Next, the resin core material is coated with a thermoplastic elastomer (Santoprene 101-73, manufactured by AES Japan Co., Ltd.) using a second extruder, and the seal portion 3, the lip portion 4, and the claw portion 2a. Were molded at the same time. Subsequently, the core material coated with the thermoplastic elastomer is heated to 100 ° C. and bent into a U-shaped cross section, and then heated to 130 ° C. to crystallize the core material, as shown in FIG. A weather strip for automobiles was obtained. The automobile weather strip manufactured in this manner has a sufficiently small distance d between the holding portions 2 and can be firmly attached to the vehicle body opening flange 51.

  The resin used for the core material was changed to polylactic acid (Teramac HV-6200, manufactured by Unitika Ltd.) and extruded, and the temperature for crystallization of the core material was set to 120 ° C. A weather strip was obtained. The automobile weather strip manufactured in this manner has a sufficiently small distance d between the holding portions 2 and can be firmly attached to the vehicle body opening flange 51.

  In the above-described embodiment, the weather strip having the lip piece 4 has been described, but it is needless to say that the present invention can be applied to a weather strip without the lip piece 4.

It is a side view of a motor vehicle. It is YY sectional drawing of FIG. It is sectional drawing which shows the weather strip for motor vehicles which embed | buried the metal core material which concerns on a prior art example. It is a perspective view which shows the resin-made core materials which concern on a prior art example. It is a perspective view which shows the resin-made and hollow core materials which concern on a prior art example. It is sectional drawing which shows the weather strip for motor vehicles which embed | buried the resin-made core materials which concern on a prior art example. It is sectional drawing which shows the weather strip for motor vehicles which embed | buried the resin-made core materials which concern on another prior art example. It is a perspective view which shows embodiment of the thermoplastic resin core material which concerns on this invention. It is a perspective view which shows other embodiment of the thermoplastic resin core material which concerns on this invention. It is the perspective view and sectional drawing which show embodiment of the weather strip for motor vehicles based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automotive weather strip 2 Holding part 2a Claw part 3 Seal part 4 Lip piece 10 Thermoplastic resin core material 20 Automotive weather strip 21 Holding part 21a Claw part 22 Seal part 23 Lip piece 30 Metal core material 40 Resin core Material 50 Car body 51 Flange 52 Interior material 60 Door D distance d distance R Rubber T Thermoplastic elastomer

Claims (4)

  A core material (10) having a U-shaped cross section embedded in a holding portion (2) of a weather strip (1) for an automobile, wherein the core material is formed by extruding a crystalline thermoplastic resin into a band shape in an amorphous state. A thermoplastic resin core material, wherein the core material is further bent into a U-shaped cross section and then heated to a crystallization temperature to be crystallized.   The thermoplastic resin core material according to claim 1, wherein the crystalline thermoplastic resin forming the core material has a glass transition temperature equivalent resin transition temperature of room temperature or higher.   An automotive weather strip made of a thermoplastic resin and having a U-shaped core material (10) embedded in a holding part (2), the core material being a crystalline thermoplastic resin in the first extrusion process In the second extrusion process, the holding part (2) has a U-shaped cross section after the core material is coated with rubber (R) or thermoplastic elastomer (T). A weather strip for automobiles, wherein the core material is formed by bending to a crystallization temperature and then being crystallized. The weather strip for automobiles according to claim 3, wherein the crystalline thermoplastic resin forming the core material has a glass transition temperature equivalent resin transition temperature of room temperature or higher.

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