JPH0324947A - Rubber laminate equipped with finish film layer - Google Patents

Abstract

PURPOSE:To obtain a wrinkle-free finish film layer improved in close adhesiveness by interposing an adhesive layer composed of a specific blend polymer or a rubber compound thereof between a rubber substrate and the finish film layer and forming the finish film layer on a sponge part from a PVC gel having a foaming recipe. CONSTITUTION:The rubber substrate 1 of a body mounting type door weather strip is made of EPDM and a finish film layer 7 is formed on the design surfaces of both of the solid part 3 and sponge part 5 of the substrate 1 using a PVC gel of a foaming recipe. The blend polymer constituting an adhesive layer 9 is formed by adding 5 - 20pts.wt. of at least one of a styrenic polymer and a polyalkenamer to 100pts.wt. of a mixture of NBR/EPDM=80/20 - 40/60. The rubber substrate 1 and the adhesive layer 9 are co-extruded using respective materials to be vulcanized under heating and the PVC gel of the foaming recipe is applied to the design surface of the rubber substrate 1 and gelled under heating to form the finish film layer 7. As a result, the finish film layer generat ing no wrinkles composed of PVC can be formed to the rubber substrate com posed of the sponge part with good close adhesiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rubber laminate in which a finish coating layer of PVC gel is formed on a rubber substrate made entirely or partially of EPDM. Products to which the rubber laminate with a finish coating layer of the present invention can be applied include door-mounted door weather strips (first and second
Weather strips include body-mounted door weather strips (Figure 2), body-mounted door weather strips (Figure 3), and roof side rail weather strips (Figure 4). A list of polymer/plasticizer abbreviations used in this specification is shown below. NBR...Nitrile rubber, EPDM...Ethylene propylene rubber (sulfur vulcanizable type), PVC...Polyvinyl chloride, PP...Polypropylene, ABS...Acrylonitrile-butadiene-styrene resin, SBS...・Styrene-butadiene-styrene block copolymer DOP...dioctyl phthalate. Moreover, in the following explanation, r part J indicating a blending unit means "part by weight".

<Conventional technology> Here, weather strips are used as rubber laminates.
Example C will be used for explanation, but it is not limited to this. For example, the body-mounted Queza Strip is
As shown in Figure 2, the rubber base 1 consists of a solid base 3 which is a U-shaped mounting base, and a sponge part 5 which is a hollow seal part. The main bodies of weather strips used in automobiles and the like are usually made of EPDM due to its weather resistance, ozone resistance, heat resistance, etc. In addition, due to the increasing demand for improved design in automobiles these days, weather strips with bright and deep black or chromatic colors have been eagerly awaited. Note that Japanese Patent Publication No. 187/1987/1299 and the like describe a technique for forming a colored rubber layer on an EPDM substrate.

However, it has been difficult to obtain a vivid and deep black or chromatic color on the molded surface of the rubber laminate due to the characteristics of the rubber material itself. For this reason, the inventor
As a result of our earnest efforts in development, we have developed a PVC gel that is easy to color brightly, can easily form thick coating layers (approx. 50 μm or more), has good weather resistance, and is easy to adjust its rigidity and hardness. (See Japanese Patent Application Nos. 63-334550 and 334551: Unpublished at the time of filing.) <Problems to be Solved by the Invention> However, when the rubber base is made of EPDM, It has been difficult to form a PVC gel with good vEs properties directly on a rubber substrate.For this reason, pretreatment such as puffing and primer treatment of the vulcanized rubber surface is necessary. It requires a lot of man-hours. In addition, solid-formulation PVC gel has difficulty imparting a soft feel to the touch and texture, and has not been able to adequately meet the demands of high-end products.

Furthermore, if the rubber base is a sponge formulation, the finish is made of a solid formulation PVC gel! ! ! Wrinkles tend to occur on the surface due to the difference in thermal expansion coefficient between the film layer and the film layer, making it impractical to form the finishing film layer on the sponge part. In view of the above, the present invention makes it possible to form a wrinkle-free finish coating layer made of PVC gel with good adhesion on a rubber substrate made of a sponge portion without the need for pretreatment that requires a lot of man-hours, and at the same time. The purpose of the present invention is to provide a rubber laminate with a finish coating layer that can impart a soft feel to the finish coating layer and can fully meet the demand for high-end products. <Means for Solving the Problems> The rubber laminate with a finish coating of the present invention solves the above problems by the following precautions. All or part of E
In a rubber laminate in which a PVC gel finish coat layer is formed on a PDM rubber base, NBR/EPDM (weight ratio) is present between the rubber base and the finish coat layer. lI
An adhesive layer made of a blend polymer or a rubber compound thereof, in which 5 to 20 parts by weight of at least one of a styrene polymer and a polyalganamer is added to 100 parts by weight of a mixture of 8o/2o to 40/60, is interposed. It is characterized in that a finishing coating layer is formed of foamed PVC gel at least on the sponge part.

<Detailed explanation of the means> The means of the present invention will be explained in detail below. In addition, in the following description, "r part" indicating a blending unit means "part by weight".

FIG. 1 shows an example of application of the present invention, in which a finish coating layer 7 is formed over the design surfaces of both the solid portion 3 and the sponge portion 5 in the rubber base 1 of a body-mounted door weather strip. It is. Further, FIG. 2 shows an example in which the C finish coating layer 7 is formed only on the sponge portion 5 on the same rubber base as in FIG. 1. Further, FIGS. 3 and 4 show examples in which the rubber bases IA and IB are applied to a door weather strip (door-mounted type) and a roof side rail weather strip, respectively, in which the rubber bases IA and IB are made up of only the sponge portion 5.

(1) Rubber base 1 is EPD! It is made by 111.

Here, EPDM refers to ethylene, brobylene, ethylidene norbornene, cyclobentadiene as a third component,
1. Adding a trace amount of non-conjugated diene such as 4-hexadiene,
It is copolymerized to introduce a double bond into the side chain, making it sulfur vulcanizable. The polymer usually contains a reinforcing filler (carbon black or white carbon),
Auxiliary materials such as plasticizers, lubricants, and vulcanizing agents are added, and in the case of sponge formulations, an appropriate amount of foaming agent is added.

Tables 1 and 2 (showing the formulations of solid sponges made of EPDM rubber compound that can be used in this example. (2) and
On the designed surfaces of the rubber substrate, that is, the solid part 3 and the sponge part 5, a finishing coating layer 3 is formed of foamed PVC gel. Here, PVC, which is the raw material for PVC gel,
Paste is blastisol or organosol made into a paste by dispersing fine base resin with a particle size of several μm or less in a plasticizer or in a dispersion medium containing a plasticizer and a diluent. After that, gelation is achieved by heating and melting (
When used as a paint, compared to solvent-based paints, there is no change in weight due to film formation (solid content concentration approximately 100%), the amount of adhesion per coat is large, and , there is almost no fire or hygiene hazard (
(See "Plastic Processing Technology Handbook," Nikkan Kogyo Shimbun, December 20, 1971, pages 485-486).

This PVC paste is usually mixed with auxiliary materials such as stabilizers, carbon black, or colorants (pigments, dyes), and furthermore, a foaming agent. As the blowing agent, azodicarbonamide (ADCA
), azobisisobutyronitrile (azo type), diphenylsulfone-3,3'-disulfonehydrazine (hydrazine type), 5-morpholyl-1,2,3,4-thiatriazole (triazole type), N, Examples include N'-dinitrosobentamethylenetetramine (N-nitroso type). The amount of these foaming agents is such that the final foaming ratio of the paste layer is 1.5 to 4.
1 to 3.5 parts. If the foaming ratio is less than 1.5, it will be difficult to obtain the desired soft feel in the finish coating layer 3, and if it exceeds 4, the strength of the finish coating layer 3 will decrease, causing problems in abrasion resistance, scratch resistance, etc. more likely to occur.

(3) In the present invention, an adhesive layer (glue line) 9 made of the following blended polymer or a rubber compound thereof is interposed between the rubber substrate 1 and the finish coating layer 7.

rNBR/EPDM (weight ratio) 80/20-40/
A blend polymer, in which 5 to 20 parts by weight of at least one of a styrene polymer and a polyalkenamer is added to 100 parts by weight of the mixture of No. 60. ” The blend polymer is disclosed in Japanese Patent Application Laid-Open No. 61-53340, 5
This is a part of those disclosed in Japanese Patent No. 3341, and those prepared by emulsion polymerization are usually used. ■ Doki NBR may be a general-purpose one, but ΔTg 63~
It is desirable to meet the requirements of 90°C and a bound nitrile amount of -10 to 50% (see JP-A-61-53340).
．． ■In NBR/EPDM, if NBR is excessive,
Adhesion to the rubber substrate and ozone resistance are poor, and excessive EPDM tends to cause problems in adhesion to the finish coating layer (PVC gel) 7. (2) Examples of the styrene polymer include ABSSBS, and examples of the polyalkenamer include transpolypentenamer and transpolyoctenamer.

■The above blended polymer usually contains auxiliary materials such as reinforcing filler (carbon plaque or white carbon), plasticizer, lubricant, vulcanizing agent, and if necessary, coloring agent. Tables 3 and 4 show the formulations of the carbon plaque compound system and the white filler compound system (for colored rubber), respectively. however,
When the thickness of the adhesive layer is made to be a thin layer of less than 0.5 IIm, if migration of auxiliary materials such as vulcanizing agent from the solid part 3 and/or sponge part 5 can be expected, it is not inevitable. (2) The thickness of the adhesive layer is 0.1 to 2 (2). 0.1
If it is less than 2 ms, it is difficult for the adhesive layer to function properly, and if it exceeds 2 ms, the material cost increases and the characteristics of the rubber base are lost, which is not desirable. (4) Methods for manufacturing the rubber laminate of the present invention include the following methods.

■Rubber base (weather strip body) 1 and adhesive 1
19 is coextruded using each material. In addition, adhesive N9
The chisel may be formed by other coating methods such as knife coating. Alternatively, the rubber substrate may be prepared by molding such as injection, transfer, or combination, and the adhesive layer may be formed from coglue, a thin sheet, etc. by means such as coating or pressing. ■Subsequently, after heating and vulcanizing the rubber base l and adhesive layer 9,
A foamed PVC gel is applied to the designed surface D of the rubber substrate 1 and heated to gel to form a finish coating layer 3.

The above PVC gel application method is one of the general-purpose application methods.
Flow coating, brush coating, roller coating, dip coating, spray coating, etc. can be applied, but flow coating is preferable if the coated surface has an uneven shape or is easily deformed. The coating amount at this time is such that the coating thickness is 50 to 2000 μm depending on the desired design. The thickness of the finished coating layer 7 after heating and gelling is 50 to 2000 μm, which is almost the same as the coating thickness before gelling.

This heat gelling process of the PVC paste may be performed after the completion of vulcanization of the rubber base 1 and the adhesive layer 9, but from the viewpoint of thermal efficiency and productivity, the process of heating and gelling the rubber base 1 and the adhesive layer 9 It is desirable that the vulcanization conditions for the EPDM rubber and the heating gelling conditions for the PVC gel be approximately the same. In this case, each step of extruding the rubber laminate, covering the adhesive layer, forming the final coating layer (foamed PVC paste layer), and vulcanizing or heating and gelling them can be made continuous. That is, after the rubber substrate 1, adhesive layer 9, and finish coating layer 7 are continuously extruded or coated, the rubber substrate 1, adhesive layer 9, and finish coating layer 7 may be continuously extruded or coated, and then transferred to a vulcanization (heat gelling) step. Effects and Effects of the Invention> The rubber laminate with a finish coating layer of the present invention has the above-mentioned
A rubber laminate in which a finishing coating layer of PVC gel is formed on a rubber base including a PDM sponge part,
NBR/EPDM (
Weight ratio) = 80/20 to 40/60 mixture 100
NBR, in which 5 to 20 parts of at least one of a styrene polymer and a polyalkenamer are added to
/E PDM Since it has an adhesive layer made of a blended polymer or a rubber compound thereof, and the PVC gel is a foamed type, it has the following functions and effects. The rubber laminate with a finish coating of the present invention comprises a rubber base and P.
Conventionally, in order to obtain good adhesion between the VC gel and the final coating layer, time-consuming pretreatments such as puff treatment and brimer treatment were required. On the other hand, the rubber laminate with a finish coating of the present invention can be applied to the sponge portion by simply interposing an adhesive layer with a specific polymeric rubber or its rubber compound, without the need for such a time-consuming pretreatment. A wrinkle-free finish coating layer made of PVC can be formed with good adhesion on a rubber substrate made of PVC.

In addition, since a foaming PVC gel is used, it is possible to easily impart a soft feeling to the touch and feel to the finished coating layer, making it possible to fully meet the demands for high-end products.

Therefore, it is possible to perform various decorative processes on the rubber base including the sponge portion.

Examples> Examples carried out to confirm the effects of the present invention will be described below. Example ■: Crosshead extruder (specifications: cylinder diameter 60II)
φ, compression ratio 1.5), rubber materials with the respective compounding formulations shown in Tables 2 and 3 were used, and in the cross section shown in Figure 3, the adhesive layer 9 (adhesive layer thickness: 0.4 m+a) Design side D
A rubber substrate (weather strip) 1 coated with was extruded (conditions: extrusion speed 5 m/min).

Subsequently, the extrudate (rubber base) 1 was coated with a foamed PVC paste (pigment: Rikiichi Bon Black) having the formulation shown in Table 5. After vacuum foaming, a shower coat method was applied to form a film with a film thickness of 100.
A final coating layer (CPVC paste layer) 7 was formed by applying the product to a thickness of 200 μm.
Vulcanization of the rubber substrate 1 and adhesive layer 9 and heating (foaming) and gelation of the base layer were simultaneously carried out under the conditions of 10 minutes at ℃. Example ■: In the above example, after extruding the rubber substrate 1, the rubber substrate 1 was carried into a hot air tank, and the rubber substrate 1 and the adhesive layer 9 were vulcanized under the conditions of 220 ° C. x 5 minutes. Thereafter, a finishing coating layer 7 was formed using PVC paste (pigment: red iron oxide) in the same manner as above, and heated and gelled under the same conditions. The thus prepared Examples ① and ②C were allowed to stand at room temperature for 24 hours, and then the adhesive strength between the finish coating layer 7 and the weatherstrip main body 1 was determined by a 180° peel test (tensile speed: 1 0
cm/min), the peel strength was 2.3.
kg/am, ■1.9kg/cm (both PVC
The adherend was broken i1). The finished coatings were deep black and red with a rich texture. Table 1 (Vehicle position: part) *Manufactured by Japan Synthetic Rubber ■Table 2 Table 1. Place: parts) Table 4 (Unit: 2 parts) *Japanese Synthetic Rubber ■Manufacturing Table 3 (Car position: parts) *Japanese Synthetic Rubber ■Manufacturing white filler compound system (N B R
/ EPDM = 70/30) Table 5 (41st place 2nd part) *Sumitomo Chemical ■Manufacturing compounding system (NBR/EPDM Yo 70/30)

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a door-mounted door weather strip to which the present invention is applied, FIG. 2 is a sectional view showing another example, and FIG. 3 is a sectional view of a body-mounted door weather strip to which the present invention is applied. FIG. 4 is a sectional view showing an example of a door weather strip, and FIG. 4 is a sectional view of a roof side rail weather strip to which the present invention is applied. 1, IA, IB...Rubber base, 3...Solid part, 5...Sponge part, 7...Finish coating layer, 9...Adhesive layer. Patent applicant

Claims (1)

[Scope of Claims] A rubber laminate, in which a finishing coating layer is formed of a gelled product of PVC paste (hereinafter referred to as "PVC gel") on a rubber base made of EPDM, which is wholly or partially a sponge part. between the rubber substrate and the finish coating layer, NBR/EPD
M (weight ratio) = 80/20 to 40/60 mixture 100
An adhesive layer made of a blended polymer or a rubber compound thereof, in which 5 to 20 parts by weight of at least one of a styrene polymer and a polyalkenamer is added based on the weight part, is interposed, and at least on the sponge part, A rubber laminate with a finishing coating layer, characterized in that the finishing coating layer is formed of a foamed PVC gel.