JP2001158824A - Method for vulcanizing and bonding unvulcanized rubber, and rubber composition for vulcanization and bonding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly vulcanize and bond unvulcanized rubbers mutually without negatively affecting physical properties or characteristics. SOLUTION: In this method for vulcanizing and bonding unvulcanized rubbers mutually, each unvulcanized rubber is compounded with 3-20 PHR wax. The rubber composition for vulcanization and bonding contains 3-20 PHR wax.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laminating unvulcanized rubbers together and vulcanizing them together, and a vulcanized adhesive rubber composition. The present invention relates to a rubber bonding method and a vulcanized bonding rubber composition therefor.

[0002]

2. Description of the Related Art Conventionally, as a general method for producing a thick rubber product (a rubber product having a thick gauge), a method in which a rubber product having a predetermined shape is formed in advance by injection molding or extrusion molding and vulcanized; There is a method in which unvulcanized rubber molded into a thin sheet is laminated and vulcanized and bonded. Of these, the injection molding and extrusion molding methods do not have a joint surface because the molded article is an integral body, and therefore have no problem such as separation at the joint interface, but require a large-sized molding apparatus. However, there is a disadvantage that the cost of the product is high.

[0003] For this reason, the vulcanization method is advantageous from the viewpoint of cost. However, the vulcanization method has a bonding surface in the manufactured rubber product, and the bonding strength at the bonding interface is not sufficient. Therefore, there is a disadvantage that the mechanical strength of the product is deteriorated. This adhesive strength tends to decrease especially when different types of unvulcanized rubber are bonded to each other.

[0004] As a method of increasing the adhesive strength by vulcanization, there is a method of compounding a large amount of sulfur as a vulcanizing agent in a rubber composition.
In addition to the problem of scorch due to early vulcanization, there is a drawback that the properties of the obtained vulcanized rubber (elongation at break (E _B ) and strength at break (T _B )) are adversely affected.

[0005] In some cases, the adhesiveness can be improved by selecting the resin components to be blended and the blending amounts thereof.
In this case also, the properties of the unvulcanized rubber or vulcanized rubber may be impaired.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides an unvulcanized rubber capable of firmly vulcanizing and bonding unvulcanized rubbers without adversely affecting physical properties or characteristics. It is an object of the present invention to provide a vulcanization bonding method and a rubber composition therefor.

[0007]

According to the present invention, there is provided a method for vulcanizing and adhering unvulcanized rubber, which comprises vulcanizing and adhering unvulcanized rubber to each other.
It is characterized by HR blending.

The vulcanized adhesive rubber composition of the present invention is characterized by containing 3 to 20 PHR of wax.

[0009] The wax is usually blended with a rubber product as a skin member such as a tire side rubber to prevent static ozone cracks, but is blended with a rubber product as an internal member. In fact, no compounding has been performed at all in order to improve the adhesion in the vulcanization bonding between unvulcanized rubbers. this is,
It was thought that the wax was compounded at the bonding interface during vulcanization, causing wax to leach out and causing poor adhesion. For this reason, conventionally, wax was compounded with unvulcanized rubber for vulcanization bonding. Was to be rather avoided.

The present inventors have conducted intensive studies to improve the adhesive strength in the vulcanization bonding between unvulcanized rubbers. As a result, a predetermined proportion of wax, which was conventionally considered unsuitable, was added. By doing so, it was found that the adhesive strength was dramatically improved without adversely affecting the physical properties or characteristics of the rubber, and the present invention was completed.

In the present invention, the details of the mechanism of the effect of improving the adhesive strength by blending the wax are not clear, but are presumed as follows. That is, sulfur greatly contributes to the vulcanization adhesion of the unvulcanized rubber, and as described above, it is preferable to mix a large amount of sulfur in order to improve the adhesion strength by the vulcanization adhesion. Mixing is not preferred in terms of deterioration of physical properties. On the other hand, when the wax is blended, the sulfur oozes out at the bonding interface with the wax at the time of vulcanization, and the amount of sulfur at the bonding interface increases, thereby increasing the amount of sulfur contributing to the vulcanization adhesion in the rubber. It is considered that the adhesive strength is improved.

In the present invention, the compounding amount of the wax in the unvulcanized rubber is particularly preferably 3 to 10 PHR.

Further, according to the present invention, the sulfur content is 2 PHR.
It is particularly effective when it is suppressed to below (however, 0.5 PHR or more).

By the way, the compounding of the resin component is effective for improving the rubber properties. However, when the resin component is compounded, especially the resin component consumes sulfur to reduce the sulfur contributing to vulcanization, thereby reducing the adhesive strength. Tends to decrease.

The present invention is particularly effective when a resin component is blended for improving physical properties, particularly when a resin component having a PHR of 15 PHR or more is blended. In addition, it is preferable that the compounding quantity of a resin component is 30-50 PHR.

The method for vulcanizing and bonding unvulcanized rubber according to the present invention is particularly suitable for producing high-damping rubber or laminated rubber for bridges or buildings.

[0017]

Embodiments of the present invention will be described below in detail.

The rubber composition for vulcanization bonding of the present invention can be used with natural rubber and / or synthetic rubber, together with wax, reinforcing materials such as carbon black and silica, fillers such as talc and clay, resin, oil (for example, Aromatic oils, naphthenic oils,
(Paraffin oil), sulfur, a vulcanization accelerator, a vulcanization aid, and the like.

In the present invention, the type of wax to be added to the unvulcanized rubber is not particularly limited. For example, paraffin wax, microcrystalline wax, liquid paraffin wax, paraffin-based synthetic wax, polyethylene wax, hydrocarbon-based wax, etc. But are not limited to these. Such waxes may be used alone or as a mixture of two or more.

The compounding amount of the wax in the unvulcanized rubber is 3 to 2
0 PHR. If the compounding amount is less than 3 PHR, the effect of improving the adhesive strength due to the compounding of the wax cannot be sufficiently obtained, and if it exceeds 20 PHR, the physical properties, particularly the breaking strength, decrease. It is particularly preferable that the amount of the wax is 3 to 10 PHR.

In the present invention, the rubber compounding of the unvulcanized rubber to be bonded is not particularly limited except that the wax is compounded in a predetermined compounding amount.
R), styrene-butadiene rubber, butadiene rubber, isoprene rubber, ethylene-propylene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, isobutylene-isoprene rubber, other synthetic rubbers, and blended rubbers of two or more of these rubbers Either may be used.

The amount of sulfur as a vulcanizing agent is not particularly limited, but the present invention is particularly effective for rubber compounding in which the amount of sulfur is suppressed to 2 PHR or less, especially 1 PHR or less, in order to improve physical properties. It is.

Further, the resin component is not less than 15 PHR, especially 3 PHR.
It is effective for rubber compounding of 0 to 50 PHR. By blending the resin in this manner, the rubber is given a vibration energy absorbing property, and the rubber can be suitably used as a seismic isolation rubber, an anti-vibration rubber, an anti-vibration rubber and the like.

As the resin, a petroleum resin obtained by thermally decomposing petroleum naphtha and polymerizing a C _{9 to} C ₁₀ fraction obtained by distillation, such as dicyclopentadiene resin, is suitable. If the amount of the petroleum resin is less than 15 PHR, the ability to absorb vibration energy is insufficient and the damping ability is deteriorated, and if it exceeds 50 PHR, the creep becomes large.

Preferred examples of the rubber compounding of the rubber composition for vulcanization bonding of the present invention include the following compounding compounds. [Rubber compounding (PHR)] Rubber: 100 Carbon black: 50 to 200 Oil: 5 to 40 Resin component: 15 or more, preferably 30 to 50 Wax: 3 to 20, preferably 3 to 10 Sulfur: 2 or less, preferably 1 or less Vulcanization accelerator: 0.5 to 5 Plasticizer (stearic acid, etc.): 1 to 10 Zinc oxide: 2 to 20 Note that the unvulcanized rubbers to be bonded are different even if they have the same rubber type. The rubber composition may be the same or different.

To vulcanize and bond unvulcanized rubbers by the method of the present invention, unvulcanized rubbers containing a predetermined amount of wax may be superposed and vulcanized and bonded according to a conventional method.
There is no particular limitation on the shape, dimensions, etc. of the unvulcanized rubber to be bonded. The bonding may be bonding between sheet materials, bonding between extruded materials, or bonding between sheet materials and extruded materials.

The vulcanization conditions vary depending on the size and shape of the product, but are usually from 130 to 160 ° C. and from 1.0 × 10 ⁶ to 1.0.
The pressure is 1.5 × 10 ⁸ Pa for about 1 to 20 hours.

The method of the present invention is suitable for producing a high damping rubber having an equivalent damping constant heq of 0.15 or more and a shear modulus G of 6 or more. In particular, the method of the invention has a thickness of 10 m.
It is suitable for the production of a laminated rubber for bridges having a thickness of about m or a laminated rubber for construction having a thickness of 2 mm or more. The present invention is also applicable to the production of all rubber products requiring vulcanization bonding, such as internal rubber of laminated rubber, skin rubber, fenders, conveyor belts, hoses, air springs, waterproof sheets, rubber dams, oil fences, etc. is there.

[0029]

The present invention will be described more specifically below with reference to examples and comparative examples.

Examples 1 to 3, Comparative Examples 1 and 2 Unvulcanized rubber (25 mm × 25 mm) having a rubber composition shown in Table 1
× 1.2 mm thick sheet-like material)
Vulcanization bonding was performed at 145 ° C. and 5.0 × 10 ⁶ Pa for 60 minutes. Various properties of the obtained adhesive rubber were measured by the following methods, and the results are shown in Table 1.

[Adhesive fatigue] Shear strain γ = 10 at a temperature of 20 ° C.
0% was repeatedly applied, and the number of repetitions leading to crack generation was examined.

[0032] In accordance with [strength at break _{T B]} JIS 6251, was measured at a tensile speed of 500mm / min.

[Attenuation] heq (equivalent damping constant), G (shear elastic modulus): 0.2 Hz, 100
It was measured under the condition of% strain.

From Table 1, it can be seen that according to the present invention, a high attenuation laminated rubber can be produced by firmly vulcanizing and bonding unvulcanized rubbers.

[0035]

[Table 1]

[0036]

As described above in detail, according to the vulcanization bonding method for unvulcanized rubber and the rubber composition for vulcanization bonding of the present invention, unvulcanized rubber can be bonded without adversely affecting physical properties or properties. Can be firmly vulcanized and bonded. The present invention, especially high damping laminated rubber for seismic isolation and bridge or building laminated rubber,
It is effective in unifying unvulcanized rubber sheets by vulcanizing and bonding them together in the production of thick rubber products such as fenders and other materials. It is possible to produce a rubber product having extremely good durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 5/00 C09J 5/00 // (C08L 21/00 (C08L 21/00 91:06) 91:06 B29K 21:00 B29K 21:00 105: 24 105: 24 F term (reference) 4F070 AA04 AA05 AA63 AC20 AC94 AE08 GC01 GC08 4F071 AA11 AA11B AA12 AA12B AA13 AA13B AA71 AA71B AA74 AA74B AB04 4 DB01 DC01 DD01 DF02 4J002 AC001 AC011 AE052 BA013 DA046 FD010 FD146 GF00 GL00 4J040 BA172 BA182 CA011 CA051 CA071 CA081 CA101 CA151 DA022 DA121 DN032 HA026 HA046 HA306 HA356 HB02 KA16 KA17 KA26 KA42 LA12 MA12 NA12

Claims (16)

[Claims] 1. A method of vulcanizing and bonding unvulcanized rubbers, wherein each unvulcanized rubber contains 3 to 20 PW of wax.
A vulcanization bonding method for an unvulcanized rubber, wherein HR is blended. 2. The method for vulcanizing and bonding an unvulcanized rubber according to claim 1, wherein the compounding amount of the wax in the unvulcanized rubber is 3 to 10 PHR. 3. The method for vulcanizing and bonding an unvulcanized rubber according to claim 1, wherein the amount of sulfur in the unvulcanized rubber is 2 PHR or less. 4. The method according to claim 1, wherein the amount of the resin component in the unvulcanized rubber is 15 PHR or more. 5. The method for vulcanizing and bonding an unvulcanized rubber according to claim 4, wherein the compounding amount of the resin component in the unvulcanized rubber is 30 to 50 PHR. 6. The method for vulcanizing and bonding an unvulcanized rubber according to claim 1, wherein the high attenuation rubber is produced by vulcanization bonding. 7. The high damping rubber according to claim 6, wherein the high damping rubber has an equivalent damping constant heq of 0.15 or more and a shear modulus G of 6 or more.
A vulcanization bonding method for unvulcanized rubber, characterized by the above. 8. The method for vulcanizing and bonding unvulcanized rubber according to claim 1, wherein vulcanized rubber for bridges or buildings is manufactured by vulcanization bonding. 9. A rubber composition for vulcanization bonding comprising a wax in an amount of 3 to 20 PHR. 10. The vulcanizing adhesive rubber composition according to claim 9, wherein the wax content is 3 to 10 PHR. 11. The rubber composition for vulcanization bonding according to claim 9, wherein the content of sulfur is 2 PHR or less. 12. The vulcanized adhesive rubber composition according to claim 9, wherein the content of the resin component is 15 PHR or more. 13. The vulcanizable adhesive rubber composition according to claim 12, wherein the content of the resin component is 30 to 50 PHR. 14. The vulcanized adhesive rubber composition according to claim 9, which is an unvulcanized rubber composition for producing a high-damping rubber. 15. The shear elastic modulus G according to claim 14, wherein the high damping rubber has an equivalent damping constant heq of 0.15 or more.
Is 6 or more. 16. The vulcanized adhesive rubber composition according to claim 9, which is an unvulcanized rubber composition for producing a laminated rubber for bridges or buildings.