JP2000272353A - Weather strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weather stripe with excellent recycling suitability and water tightness. SOLUTION: A weather strip WS2 is produced by integral molding of a relatively thick base bottom part 11, a relatively thin hollow seal part 12, and a vehicle outer side seal strip part 13. Since at least the hollow seal part 12 comprises a foamed member produced by foaming a thermoplastic elastomer composition with water serving as a foaming agent, and a coated film CL provided on the surface of the foamed member with a water repellent property of a 90 deg. or more contact angle with respect to water, the coat film CL with a rich water repellent property covers the surface of the foamed member at least in the part providing the hollow seal part 12 so as to seal open cells for maintaining the water absorbency of the foamed member at a low level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip mounted around a door of a vehicle to seal between the door and the vehicle body.

[0002]

2. Description of the Related Art In a vehicle, especially a passenger car, a weatherstrip door fixed to a frame around a door periphery to seal a space between the door and the vehicle body is usually provided on a front pillar, a roof panel, a center pillar, a rear pillar, etc., as shown in FIG. Peripheral edges of the facing front door FD and rear door RD are made of a synthetic solid rubber material made of, for example, ethylene propylene rubber material.
It is extruded and molded from a synthetic sponge rubber material and / or a synthetic resin material, and is connected endlessly at a connection portion of each of their opposite terminals.

In the conventional weather strip WS ₁ , the extruded portion 1 is used in a substantially linear and long region, and one molding corner 5 is used in a relatively curved and relatively short region. In addition, the said molding | molding corner part 5 produces | generates the said synthetic solid rubber material by the molding method with the special shape which is unsuitable by extrusion molding.
It is molded from a synthetic sponge rubber material and / or a synthetic resin material.

FIG. 3 is a perspective view showing a main part of the extruded part 1 of the conventional weather strip WS ₁ with a part thereof cut away. The extruded portion 1 of the conventional weather strip WS ₁ has a relatively thick base portion 2, a relatively thin hollow seal portion 3, and a vehicle exterior seal lip portion 4. On the other hand, the molding corner 6 also has some changes in the extruded part 1 and its cross-sectional shape, but basically, similarly to the extruded part 1, a relatively thick base part. And a relatively thin hollow seal portion and a vehicle exterior seal lip portion (both not shown). recent years,
It is strongly desired to increase recyclability, and as a result, the weather strip WS ₁ to which a foam obtained by foam-forming a thermoplastic elastomer composition using water as a foaming agent is applied.
Attracted attention.

[0005]

However, since the water foam has open cells, it has a significantly higher water absorption than a vulcanized rubber foam, and thus has a problem in water sealability. In order to solve the difficulties related to the water sealing property, it has been proposed to apply a urethane resin, a silicone resin, or the like having a hydrophobic property and a small frictional resistance to the surface of the water foam. Since the body has a large number of pinholes on its surface, a desired water-sealing property could not be obtained only by imparting hydrophobicity.

US Pat. No. 5,192,586 discloses a method of co-extrusion of the water foam and the hard resin. However, the surface of the water foam is easily formed into a wavy shape.
Further, the two layers were easily separated. On the other hand, in order to avoid the occurrence of the waving and peeling phenomena, it is necessary to cope with the foaming in the high specific gravity region in which the degree of foaming is suppressed, and as a result, the degree of freedom regarding the specific gravity of the water foam is reduced. Invited disadvantages.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a weather strip excellent in recyclability and water sealability.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a weather strip in which a relatively thick base portion, a relatively thin hollow seal portion and an outer seal lip portion are integrally formed. The hollow seal portion has a foam formed by foaming a thermoplastic elastomer composition using water as a foaming agent, and a water repellent having a contact angle with water of 90 ° or more, and a layer formed on the surface of the foam. This is attained by a weatherstrip characterized by comprising a coating film provided.

Further, the object of the present invention is that the coating film is prepared by diluting a fluororesin, polyethylene, polypropylene, a compound obtained by chemically modifying these polymers, or a mixture of two or more of these polymers with a solvent, This is achieved by a weatherstrip characterized by being dry.

[0010] Further, the object of the present invention is that the solvent comprises:
This is achieved by a weatherstrip characterized by one or more selected from xylene, methyl isobutyl ketone, isopropyl alcohol, or methyl ethyl ketone.

[0011]

The weather strip according to the present invention is a weather strip in which the relatively thick base portion, the relatively thin hollow seal portion and the outer seal lip portion are integrally formed, and at least the hollow portion is formed. The foamed seal is formed by foaming the thermoplastic elastomer composition using water as a foaming agent, and a layer having a water repellency having a contact angle with water of 90 ° or more is formed on the surface of the foam. The coating film having high water repellency covers at least the surface of the foam forming the hollow seal portion and seals open cells to reduce the water absorption of the foam. Keep low.

Further, in the weather strip of the present invention, the coating film may be prepared by diluting a fluororesin, polyethylene, polypropylene, a compound obtained by chemically modifying these polymers, or a mixture of two or more of these polymers with a solvent. ,
Since the coating film is dried, the coating film maintains a high contact angle with water, has a large water repellency, and imparts a desired water sealing property to the foam.

Further, in the weather strip of the present invention, since the solvent is selected from one or more of xylene, methyl isobutyl ketone, isopropyl alcohol, and methyl ethyl ketone, the solution of the coating film is relatively inexpensive and easy to handle. Become.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the weather strip of the present invention will be described below in detail with reference to the accompanying drawings. Figure 1 is a perspective view of an essential part shown broken away portion of the extruded portion 10 in the weather strip WS ₂ of the present invention. The essential part of the weather strip WS ₂ of the present invention is the same as the conventional weather strip W described above except for a coating film CL described later.
Since it is equivalent to the main part of S _1, illustrating a feature point of the weather strip WS ₂ of the present invention with a extruded section 10.

The extruded portion 10 of the weather strip WS ₂ of the present invention is formed by foaming a thermoplastic elastomer composition by using water as a foaming agent while extruding the thermoplastic elastomer composition, and then cooling the foamed material. The base portion 11 of the meat, the hollow seal portion 12 and the seal lip portion 13 having a relatively thin thickness are integrally formed, and the base portion 11 has a water repellency having a contact angle with water of 90 ° or more. , Hollow seal part 1
2 and a coating film CL layered on the outer surface of the outer seal lip portion 13.

The coating film CL is made of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether copolymer, or tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. Polymer, ethylene / tetrafluoroethylene copolymer, polychlorotrifluoroethylene, ethylene / chlorotrifluoroethylene copolymer,
Polyvinylidene fluoride, fluorine resin such as polyvinyl fluoride, polyethylene, polypropylene, a compound obtained by chemically modifying these polymers, or a mixture of two or more of these polymers as a solvent such as xylene, methyl isobutyl ketone, isopropyl alcohol, or the coating solution obtained by diluting with one or more selected solvents of methyl ethyl ketone, applied to the outer surface of the weather strip WS _2, formed by drying.

Further, the contact angle of each component for forming the coating film CL with water is as follows.
-113 °, polyethylene 92-96 °, polypropylene 95-98 °, ethyl ester-modified polyethylene 116 °, octyl ester-modified polyethylene 125 °, and a mixture of two or more of these polymers. The contact angle with water is estimated based on the sum of the components distributed according to the ratio of each component.

The coating film CL is applied as a lower layer of a urethane resin or silicone resin coating film provided on the outer surface of a weather strip made of vulcanized rubber, or as a mixture with a urethane resin, a silicone resin or the like. Can be worn. Further, the coating film CL can be applied to a foam obtained by foaming a thermoplastic elastomer composition using a chemical agent as a foaming agent. Further, the coating film CL
According to the conditions such as the arrangement position of the weather strip WS ₂ , it is also possible to form a layer only on the outer surface of the hollow seal portion 12 without layering the entire outer surface thereof.

[0019]

The weatherstrip of the present invention described above has the following novel effects. That is, the weather strip of the present invention is a weather strip in which the relatively thick base portion, the relatively thin hollow seal portion and the outer seal lip portion are integrally formed, and at least the hollow A sealing portion formed on the surface of the foam by foaming the thermoplastic elastomer composition using water as a foaming agent; and a water repellent having a contact angle of 90 ° or more with water. The coating film having high water repellency covers at least the surface of the foam forming the hollow seal portion and seals open cells to reduce the water absorption of the foam. It became possible to keep.

Further, in the weather strip of the present invention, the coating film is formed by diluting a fluororesin, polyethylene, polypropylene, a compound obtained by chemically modifying these polymers, or a mixture of two or more of these polymers with a solvent. ,
Since the coating film is dried, the coating film maintains a high contact angle with water, has a large water repellency, and can impart a desired water-sealing property to the foam. .

Furthermore, in the weather strip of the present invention, since the solvent is selected from one or more of xylene, methyl isobutyl ketone, isopropyl alcohol, and methyl ethyl ketone, the solution of the coating film, which is relatively inexpensive and easy to handle, can be used. It became possible to obtain. The novel effects of the weather strip of the present invention described above are further clarified by Examples and Comparative Examples.

[Embodiment] The hollow seal portion 1 in FIG.
Sample No. 2 was molded from a foam obtained by foaming a thermoplastic elastomer composition using water as a foaming agent, and various coating films were layered on its outer surface, and the water absorption of the hollow seal portion was measured and compared. Table 1 shows the results of the measurements of the foam materials, coating film composition conditions, and water absorption.

[Comparative Example] The hollow seal portion 3 in FIG.
And a hollow seal portion in which a foam formed by vulcanizing a thermoplastic elastomer composition using water as a foaming agent and water as a foaming agent is molded into two types, and a coating film is not layered on the outer surface thereof. Then, the water absorption of the hollow seal portion provided with the coating film was measured and compared. Table 1 shows the results of the measurements of the foam materials, coating film composition conditions, and water absorption.

[0024]

[Table 1]

As is apparent from Table 1, Examples 1 and 2 in which a coating film made of polytetrafluoroethylene was provided on the outer surface of a foam obtained by foaming a thermoplastic elastomer composition using water as a foaming agent were formed. It was confirmed that Example 2 exhibited much better water absorption than the hollow seal portions of Comparative Examples 1 to 3.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a weather strip of the present invention in a partially cutaway manner.

FIG. 2 is a side view of a weather strip mounted around a door of a passenger car.

FIG. 3 is a perspective view showing a main part of a conventional weather strip with a part thereof cut away.

[Description of Signs] FD Front door RD Rear door WS ₁ Conventional weather strip 1 Extruded part 2 Base part 3 Hollow seal part 4 Outside seal lip part 5 Mold forming corner WS ₂ Weather strip of the present invention 10 Extruded part Reference Signs List 11 base 12 hollow seal 13 exterior seal lip CL coating

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B60R 13/06 B60R 13/06 C08J 9/224 CEQ C08J 9/224 CEQ 9/36 CEQ 9/36 CEQ C09D 123/06 C09D 123/06 123/12 123/12 127/12 127/12 // C08L 21:00 F term (reference) 3D024 AA06 AB04 AB17 AB21 AB33 AB36 AB57 4D075 CA36 DA23 DB31 DC13 EA05 EB13 EB16 EC30 4F074 AA05 BA34 CE02 CE16 CE27 CE33 CE34 CE46 CE47 CE50 CE83 DA39 4J038 CD091 CD101 CD111 CD121 CD131 JA05 JA19 JA33 KA06 MA07 MA09 MA12 NA07 PA16 PB07 PC07

Claims (3)

[Claims] A weather strip (W) in which a relatively thick base portion (11), a relatively thin hollow seal portion (12) and an outer seal lip portion (13) are integrally formed.
S ₂ ) wherein at least the hollow seal portion (12) has a water-repellent property in which a foam obtained by foam-forming a thermoplastic elastomer composition using water as a foaming agent has a contact angle of 90 ° or more with water. A weather strip comprising a coating film (CL) layered on a surface of the foam body. 2. The coating film (CL) is prepared by diluting a fluororesin, polyethylene, polypropylene, a compound obtained by chemically modifying these polymers, or a mixture of two or more of these polymers with a solvent, coating and drying. The weatherstrip according to claim 1, wherein the weatherstrip is formed. 3. The weather strip according to claim 2, wherein the solvent is at least one selected from xylene, methyl isobutyl ketone, isopropyl alcohol, and methyl ethyl ketone.