JPH0818521B2 - Weather strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a weather strip made of ethylene propylene rubber.

Here, the weather strip includes door weather strips, trunk-lid weather strips, sunroof weather strips, and the like, which are directly referred to as weather strips, and glass runs and window frame rubbers. It is a concept that also includes etc.

<Prior Art> Generally, the weather strip substrate material as described above is required to have weather resistance, ozone resistance, heat resistance, and the like.
They are often formed of EPDM rubber vulcanizates that have excellent physical properties and are capable of sulfur vulcanization.

The EPDM polymerization catalyst is generally an organoaluminum-based and vanadium chloride-based combination type ("Synthetic Rubber Processing Technology Complete Book, Ethylene / Propylene Rubber", issued July 10, 1972, Taiseisha Co., Ltd.). Pp. 7-8).

On the other hand, on the design side of these weather strips,
With the recent trend toward high-grade automobiles, stricter quality of appearance is required more than ever before.

<Problems to be Solved by the Invention> As one of the requirements for the appearance quality, fine foreign matter (0.1
~ 0.5 mm) may not appear on the surface of the design surface.

In view of the above, an object of the present invention is to provide a weather strip in which minute foreign matter does not appear on the surface of the design surface.

<Means for Solving the Problems> In order to solve the above problems, the inventors of the present invention have determined that the main constituent of the minute foreign matter that appears on the design surface surface of the weather strip is the polymerization catalyst residue in the polymer. The present invention has been found out, and the present invention having the following constitution was conceived.

At least the design surface of the weather strip body is formed of a rubber vulcanizate of EPDM, and the EPDM is a weather strip whose polymerization catalyst is a combination type of vanadium chloride and organoaluminum, and 80 meshes of the polymerization catalyst residue in EPDM. The remaining number is 25 pieces / 3 kg or less.

<Detailed Description of Means> Hereinafter, embodiments of the present invention will be described. Here, “parts” and “%” indicating a combination unit are, unless otherwise specified,
It is a unit of weight.

Here, as the weather strip, a door weather strip including a mounting portion 1 made of solid rubber having a U-shaped cross section as shown in FIG. 1 and a hollow seal portion 3 made of tubular sponge rubber will be described as an example. , But is not limited to this.

(1) The attachment portion 1 and the hollow seal portion 3 are made of a vulcanized product of EPDM compounded with a solid rubber / foamed rubber compounding formulation. The EPDM used here is not necessarily the EPDM described later.
The residual polymerization catalyst may not satisfy the requirements of the present invention.

(2) At least the design surface D of the weather strip body is EP
The EPDM is formed of rubber vulcanizate of DM, and the polymerization catalyst of EPDM is a combination type of vanadium chloride and organic aluminum.
As shown in the figure, the design rubber layer 5 may be formed only on the design surface,
It may be integrated with the mounting portion main body 1.

The above-mentioned vulcanizate compound is usually an auxiliary material compounded in a rubber compound for extrudates, for example, carbon black, processing aids, plasticizers, zinc white, antioxidants, vulcanizing agents, Inorganic fillers and the like are appropriately mixed.

The production of the extruded product of the present invention is carried out by multicolor extrusion using a crosshead extruder, and the weather strip body 1,
It is molded in a state where the design rubber layer 5 is formed on 3 and vulcanized by a conventional method.

 Up to this point, the configuration is the same as the conventional configuration.

(3) A characteristic constitution of the present invention is that, in the weather strip having the above constitution, the number of residual 80 mesh of the polymerization catalyst residue in EPDM is 25/3 kg or less.

Here, the 80 mesh residual number means the result measured by the following method.

Using an extruder with an 80 mesh wire mesh attached at the tip of an extrusion die (diameter: 5 cm), 3 kg of weighed polymer was adjusted to an extrusion head temperature of 80 ° C and extruded at a screw rotation speed of 50 RPM. Remove and count the number of foreign substances attached to the wire mesh.

Further, in order to set the 80 mesh residual number of the polymerization catalyst residue to the condition of the present invention, EPDM is polymerized (usually solution ion polymerization) and then washed with water. If a single washing is not enough, the water is replaced with fresh one, or the washing is repeated, so that the residual rate of the polymerization catalyst residue conforms to the conditions of the present invention.

<Operations and Effects of the Invention> As described above, the weather strip of the present invention has a residual ratio of the polymerization catalyst residue in the polymer component as a predetermined amount or less as a polymer of the EPDM vulcanizate that forms at least the design surface of the weather strip. Therefore, as shown in the following test example,
The appearance rate of minute foreign matter on the design surface of the weather strip is significantly reduced. Therefore, it is possible to manufacture a weather strip that meets the strict requirements for appearance quality with good productivity, that is, with a low defect occurrence rate.

<Test Example> In EPDM having the following formulation, strips having a cross section of 20 mm × 20 mmt were extruded by using each polymer having the residual ratio of the polymerization catalyst shown in Table 1. Then, the appearance rate of the minute foreign matter per 1 m was visually determined. The results are shown in Table 1. It can be seen that when the residual number of 80 mesh mesh wire is 25 pieces / 3 kg or less, the appearance rate of the minute foreign matter on the surface of the rubber extrudate is significantly reduced. EPDM compounded polymer 100 parts Carbon black 60 parts Process oil 50 parts Zinc white 5 parts Stear powder 1 part Calcium oxide 5 parts Vulcanization accelerator 4.5 parts Sulfur 1.5 parts

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view of a weather strip, which is an example of the weather strip to which the present invention is applied. 1 ... Attachment part, 3 ... Hollow seal part, 5 ... Design rubber layer, D ... Design surface.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area B29K 105: 24 B29L 31:58

Claims (1)

[Claims] 1. A weather vulcanized product of an ethylene-propylene-diene terpolymer (hereinafter abbreviated as "EPDM") on at least the design surface of the weather strip body, wherein the EPDM is used.
In a weather strip whose polymerization catalyst is a combination type of vanadium chloride and organoaluminum, the residual number of 80 meshes of the polymerization catalyst residue in EPDM is
The weather strip is characterized in that the number is 25 pieces / 3 kg or less.