JPH03240536A - Cloth like finish of rubber extruded product - Google Patents

Abstract

PURPOSE:To improve the productivity by bonding strip cloth to the design surface of a solid rubber part to finish the design surface of a rubber extruded product in a cloth like manner. CONSTITUTION:The first adhesive layer 7 composed of blend rubber or a rubber compound thereof is formed to the design surface D of a solid rubber part 3 to extrude an extruded product main body 1. The main body is formed from a composition of NBR : 40 - 80wt.%, EPDM 20 - 60wt.% and SBR : 0 - 35wt.%. Immediately after the extrusion of the extruded product main body 1, PVC paste is applied to the first adhesive layer 7 and strip cloth 9 is bonded to this second adhesive layer 8 under pressure. Next, the second adhesive layer 8 is heated and gelled in a vulcanizing process to complete the integral bonding of the strip cloth 9 to a rubber extruded product.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for texture finishing a rubber extrudate, the extrudate body of which includes a solid rubber portion made of EPDM. In particular, the present invention relates to a method suitable for finishing the design surface of automobile interior rubber products such as weather strips and trims in a textured manner.

A list of polymer/plasticizer abbreviations used in this specification is shown below.

NBR...Nitrile rubber, EPDM...Ethylene propylene rubber (sulfur vulcanizable type), SBR...Styrene butadiene rubber, PVC...Polyvinyl chloride, DOP...Dioctyl phthalate.

<Prior Art> Here, explanation will be given using a door weather strip as shown in FIGS. 2 and 3 as an example of a rubber extruded product, but the present invention is not limited to these.

The weatherstrip body (extrusion body) is usually weather resistant.
Many are made of EPDM from the standpoint of ozone resistance, heat resistance, etc.

In addition, due to the increasing demand for improved design in automobiles these days, there are cases where it is desired to finish the design of the weather strip in a similar manner to the interior design. In such cases, there is a method of pasting cloth on the design surface (Utility Model Publication No. 62-8865).
(See Publication No. 5, etc.)

<Problems to be Solved by the Invention> However, in the above method, in order to finish the designed surface of the rubber extruded product into a mold, the designed surface of the rubber extruded product after vulcanization must be puff-finished, degreased, coated with a primer, and bonded. agent application, pasting on cloth,
Many man-hours were required for curing the adhesive, and productivity was poor.

In view of the above, the present invention provides a cloth-like finish for rubber extrusions that can finish the rubber extrusions into shapes with good productivity by pasting cloth on the design surface of the solid rubber part. The purpose is to provide a method.

<Means for Solving the Problems> The method for finishing the texture of rubber extrudates of the present invention solves the above problems.
This problem is solved by the following configuration.

In a rubber extrusion product whose extrusion body includes a solid rubber part made of EPDM, a cloth is pasted on the designed surface of the solid rubber part to form the designed surface of the rubber extrusion into a shape. , on the designed surface of the solid rubber part, NBR:
forming a first adhesive layer consisting of a blended rubber or a rubber compound thereof containing 40 to 80% by weight, EPDM: 20 to 60% by weight, and SBR: 0 to 35% by weight, and extruding the extrudate body; Immediately after, apply the PVC paste to the first
coating on the adhesive layer to form a second adhesive layer;
A band cloth is crimped onto the second adhesive layer, and in the step of vulcanizing the extrudate main body, the second adhesive layer is heated to gel, and the band cloth is integrally attached to the rubber extrusion product. It is characterized by completing.

Detailed explanation of the method The means of the present invention will be explained in detail below.

In addition, "%" and "part" indicating the compounding unit in the following explanation are
Units are by weight unless otherwise specified.

(1) In the method of the present invention, basically, the extruded product body 1 is
In a rubber extrusion product including a solid rubber part 3 made of PDM, a method of finishing the design surface of the rubber extrusion product into a shape by pasting cloth (banding cloth) 9 on the design surface of the solid rubber part 3. be.

On the national side, the extruded product main body 1 is a door weather strip consisting of a solid rubber part 3 and a sponge rubber part 5, each made of EPDM.

■Here, EPDM is made by adding a trace amount of non-conjugated diene such as ethylidene norbornene, dicyclopentadiene, or 1,4-hexadiene as a third component to ethylene or propylene, and copolymerizing it to form a double bond in the side chain. This made it possible to vulcanize with sulfur.

The polymer usually contains a reinforcing filler (carbon black or white carbon), a plasticizer, a lubricant,
Add auxiliary materials such as vulcanizing chemicals.

Tables 1 and 2 show the formulations of EPDM solid rubber/sponge rubber compounds that can be used in the present invention.

■The above-mentioned PVC base is plastisol or organosol, which is made into a paste by dispersing fine paste resin with a particle size of several μm or less in a plasticizer or a dispersion medium containing a plasticizer and a diluent. After forming, it is gelled (cured) by heating and melting, and when used as a paint, there is no weight change due to film formation compared to solvent-based paints (solid content concentration approximately 100%), - The amount of adhesion after multiple coatings is large, and there is almost no fire or hygiene hazard ("Plastic Processing Technology Handbook" Nikkan Kogyo Shimbun Materials, published December 20, 1978, Nos. 485-48)
(See page 6). This PVC paste usually contains auxiliary materials such as stabilizers, carbon black, or colorants (pigments, dyes).

(2) The type of the band cloth 9 is not particularly limited, and may be a woven fabric, a non-woven fabric, or the like. Furthermore, the type of fibers constituting the band cloth can also be determined by the second adhesive layer 8.
Particularly poor adhesion with 1. +) There are no particular limitations, and polyester fibers, nylon fibers, etc. are usually used from the viewpoint of weather resistance, abrasion resistance, economic efficiency, etc.

(3) The first feature of the method of the present invention is that a first adhesive layer 7 made of the following specific blend rubber or a rubber compound thereof is formed on the designed surface of the solid rubber portion 3 to form the extruded product body. Extrude 1. That is, the solid sponge rubber portion 3.5 of the weatherstrip body 1 and the first adhesive layer 7 are coextruded using each material. That is, the extruders 11, 12 and 13 for the solid sponge rubber part and the first adhesive layer are connected to the multicolor extrusion head 15 to perform coextrusion. In front of the extrusion head 15, a roll 16 for feeding out the insert 2 is arranged.

The above blended rubber is NBR・40~80%, EPDM
: 20 to 60%, and SBR: 0 to 35%.

The blended rubber is the same as that disclosed in JP-A-62-172043, and is usually prepared by emulsion polymerization.

■If the NBR is less than 40%, there will be a problem in adhesion with the second adhesive layer (PVC paste layer) 8, and if it exceeds 80%, the adhesion with the EPDM solid rubber part and ozone resistance will be poor. bad.

■If EPDM is less than 20%, ozone resistance is poor and 60%
%, a problem will arise in the adhesion with the second adhesive layer (PVC paste layer) 8.

(2) If the SBR exceeds 35%, the adhesion to the PVC paste layer will deteriorate and the ozone resistance will also deteriorate. In addition, SBR may be 0%, but if it is mixed with 2% or more,
This is desirable because it increases the adhesion to the solid rubber part (EPDM base).

(2) The above blended rubber usually contains auxiliary materials such as a reinforcing filler (carbon black or white carbon), a plasticizer, a lubricant, a vulcanizing agent, and, if necessary, a coloring agent.

Table 3 shows the formulation of the carbon black compounding system that can be used in the present invention. At this time, if the thickness of the first adhesive layer 7 is set to be a thin layer of less than 0.5 mm so that migration of auxiliary materials such as vulcanizing agent from the solid rubber part 3 can be expected, the mixture of auxiliary materials can be improved. This is unnecessary and desirable.

(2) The thickness of the first adhesive layer 7 is 0.1 to 2 mm. If the thickness is less than 0.1 mm, the adhesive layer will not be able to function properly, and 2
If it exceeds mm, the material cost will increase and the properties of the solid rubber part will be lost, which is undesirable. Apply PVC paste according to step 17.

■As for the application method, among the general-purpose methods, various methods such as flow coating (shower coat), brush coating, roller coating, dip coating, and spray coating can be applied, but if the coating surface has an uneven shape, , if it is easily deformed, flow painting is recommended.

(2) The thickness of the second adhesive layer 8 is 50 to 100 μm. If it is less than 50 μm, it is difficult to obtain sufficient adhesive strength;
When the thickness exceeds 0 μm, not only can no increase in adhesive strength be expected, but the adhesive strength actually decreases, and material costs also increase.

(4) Next, the band 9 is pressed onto the second adhesive layer 8.

This crimping step is carried out on the national side by crimping the band 9 fed out from the band fabric feeding roll 18 onto the second adhesive layer 8 by a pair of crimping rolls 19. Further, the crimping step is performed before the microwave vulcanization bath (UHF tank) 21, but may be performed between the UHFHF tank and the 1-air vulcanization tank (HAV tank) 22. (4) The above-mentioned second adhesion The extruded product main body 1 with the band 9 crimped onto the adhesive layer 8 is transported to a vulcanization process, and in the vulcanization process, the second adhesive layer 8 is heated to gel,
The attachment and integration of the band cloth 9 to the rubber extrusion product is completed.

On the national side, the vulcanization process consists of UHF, JI21, and two HAV tanks. After the vulcanization process, the band 9 is embossed using an embossing roll 24 as required by the Japanese government, and then transported to a water cooling process and a bending process.

The above vulcanization conditions are usually 200° C. for 3 to 10 minutes.

These conditions are sufficient for heating and gelling the PVC paste.

In the case of the fabric finishing method of the present invention, it is possible to apply a continuous process of extruding and vulcanizing the weatherstrip, resulting in good productivity. That is, immediately after extruding the extruded product body 1 provided with the first adhesive layer 7, a PVC base is applied and a second adhesive layer 7 is applied.
It is only necessary to shape the adhesive layer 8, then press the strip onto the second adhesive layer and transport it to the vulcanization process.

<Operations and Effects of the Invention> As described above, the cloth finishing method for rubber extrudates of the present invention is as follows.
In a rubber extrusion product whose main body includes a solid rubber part made of EPDM, a method for finishing the design surface of the rubber extrusion product to be made of cloth by pasting cloth on the design surface of the solid rubber part, the solid rubber NBR: 4 on the design surface of the section.
0-80%, EPDM: 20-60%, and SBR: 0
The extrudate body is extruded by forming a first adhesive layer of ~35% blended rubber or a rubber compound thereof, and immediately after the extrusion, a PVC paste is applied onto the first adhesive layer to form a second adhesive layer. forming an adhesive layer, then pressing a band on the second adhesive layer, and vulcanizing the extrudate body;
Since the configuration is characterized in that the second adhesive layer is heated and gelled to complete the attachment of the band cloth to the rubber extrusion product, the following functions and effects are achieved.

Conventionally, in order to apply cloth finishing to the designed surface of a rubber extrusion product, the designed surface of the rubber extrusion product after vulcanization was puff finished and degreased with IA.
This required a lot of man-hours, such as cleaning, applying brimer, applying adhesive, attaching fabrics, and curing the adhesive.

In contrast to this conventional method, the method of the present invention is based on the first adhesive layer 7.
Immediately after extrusion of the extruded product body 1 with It can be transported easily and productivity is greatly improved.

The first adhesive layer 7 is applied to the solid rubber portion 3 of the extruded body, the second adhesive layer 8 is applied to the first adhesive layer 7, and the band 9 is applied to the second adhesive layer 8. As shown in the examples below, it has a sufficient practical strength of 1.

In addition, when it is desired to finish different fabrics in which predetermined colors are arranged alternately at predetermined lengths in the extrusion direction, or when finishing different fabrics in parallel in the extrusion direction, parallel or Good productivity is achieved by simply crimping the band fabric alternately (Example) Below are examples and comparative examples conducted to confirm the adhesive strength between the extruded product body and the band fabric in the method of the present invention. I will explain about it.

Crosshead type extruder (specification cylinder diameter 60mmφ
, a compression ratio of 1.5) to form the solid rubber portion 3, sponge rubber portion 5, and first adhesive layer 7, respectively. Second
Weatherstrip with the cross section shown in the figure (however, excluding the second adhesive layer 8 and band 9. First adhesive layer thickness: 0.4 mm
) (conditions: extrusion speed 5 m/min), PVC paste (after vacuum degassing) having the formulation shown in Table 4 was applied to a film thickness of 100 μm using the shower coat method.
An adhesive layer (PVC paste layer) 8 was formed, and a band cloth (width: 40 mm,
After crimping the extrudate (thickness: 2mmt), the extrudate was
The main body 1 and the adhesive layer 8 were simultaneously vulcanized and heated to gelatinization at 200° C. for 10 minutes to complete the integral attachment of the band 9 to the rubber extrusion.

After leaving the example thus prepared at room temperature for 24 hours,
The adhesion strength of the band cloth 9 to the base material (rubber extrusion product) was determined by gripping the cloth piece 9 and performing a 180° peel test (tensile speed: 10
The peel strength was measured at 2.3 k/min).
g/cm (base material failure).

(unit parts by weight) Vermilion table (unit parts by weight) *Manufactured by Japan Synthetic Rubber *Manufactured by Japan Synthetic Rubber No. table *Manufactured by Japan Synthetic Rubber *Manufactured by Sumitomo Chemical

[Brief explanation of drawings]

Fig. 1 is a schematic process diagram showing an example of the method for finishing the right side of a rubber extruded product according to the present invention; Fig. 2 is a cross-sectional perspective view showing an example of a weather strip finished on the right side by the method of the present invention; FIG. 3 is a cross-sectional perspective view of a trim portion of the weather strip shown in FIG. 2 which is bent. DESCRIPTION OF SYMBOLS 1... Weatherstrip body, 3... Solid rubber part, 5... Sponge rubber part, 7... First adhesive layer, 8... Second adhesive layer, 9... Banding fabric , 17...Paste application device, 18...Band cloth feeding roll, 19...Band fabric pressure bonding roll, 22...Hot air vulcanization tank (I(A vat) D...Design surface. Patent Applicant Toyoda Gosei Co., Ltd. 1″ (

Claims (1)

[Claims] In a rubber extrusion product whose main body includes a solid rubber part made of EPDM, a cloth is attached onto the designed surface of the solid rubber part to give the designed surface of the rubber extrusion a cloth-like appearance. In the finishing method, NBR: 40 to 8 is applied to the designed surface of the solid rubber part.
0% by weight, EPDM: 20-60% by weight, and SBR:
forming a first adhesive layer consisting of 0 to 35% by weight of blended rubber or a rubber compound thereof and extruding the extrudate body; immediately after the extrusion, applying a PVC paste on the first adhesive layer; forming a second adhesive layer, then pressing a predetermined band on the second adhesive layer, and heating and gelling the second adhesive layer in the vulcanization process of the extruded body; A method for finishing the texture of a rubber extruded product, comprising: completing the integration of adhesion of the band cloth to the rubber extrusion.