JP3606765B2 - Rubber composite and production method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rubber composite and a method for producing the same.
[0002]
[Prior art]
Rubber-based composites in which a rubber member is vulcanized and bonded to a metal member or a synthetic resin member are widely known. In the vulcanization bonding, an adhesive is applied to the bonding surface of the metal member or the synthetic resin member, an unvulcanized rubber material is stacked thereon, and the unvulcanized rubber material is pressurized and heated with a molding hot platen. Alternatively, a method of placing in a vulcanizing can and heating under pressure is generally employed.
[0003]
[Problems to be solved by the invention]
However, the obtained rubber-based composite has a metal member or a synthetic resin member and a rubber member adhered to the entire surface. However, if the rubber composite is used for a long time in an atmosphere exposed to oil splashes or in a state immersed in oil, the adhesion There is a problem that the rubber member easily peels off due to oil entering the interface.
[0004]
Then, this invention makes it a subject to raise the adhesive strength of the rubber member in a rubber-type composite.
[0005]
[Means for Solving the Problems]
The present inventor has found that the above problem of peeling can be solved if the cross-linking density of the adhesive is increased at the peripheral edge of the adhesive surface, and the present invention has been completed. It is.
[0006]
That is, the invention according to claim 1 is a rubber-based composite formed by vulcanizing and bonding a rubber member to an adherend member formed of metal or synthetic resin,
The crosslink density of the adhesive at the peripheral portion of the adhesive surface is higher than the crosslink density of the adhesive at the central portion of the adhesive surface between the rubber member and the adherent member.
[0007]
The high crosslink density of the adhesive means that the adhesive strength between the rubber member and the adherend is high, and the crosslink density is particularly high at the periphery of the adhesive surface. Even if it is exposed to the atmosphere, the oil does not easily enter the adhesive interface between the rubber member and the adherend member, and the rubber member is prevented from peeling off from the adherend member.
[0008]
Further, if the cross-linking density of the adhesive is increased over the entire adhesive surface, for example, it is necessary to increase the time for heating and pressurizing the rubber member, which may impair the physical properties of the entire rubber member. On the other hand, the invention according to claim 1 is a configuration in which the cross-linking density of the adhesive at the peripheral portion of the adhesive surface is made higher than that at the central portion of the adhesive surface, so there is no need to heat the entire rubber member excessively. Accordingly, it is possible to prevent the rubber member from peeling without deteriorating the physical properties of the rubber member.
[0009]
That is, conventionally, the vulcanization conditions are determined from the physical property requirements of the rubber member. Therefore, the crosslinking density of the adhesive is not particularly problematic, and as a result, the adhesive is applied with a relatively low crosslinking density. Sulfur was stopped. On the other hand, the present invention can further increase the cross-linking density of the adhesive, thereby reviewing the rubber-based composite from the viewpoint that the adhesive strength between the rubber member and the adherent member is increased, and the adhesive surface It has been found that if the crosslink density of the adhesive at the peripheral edge is made higher than that at the center of the adhesive surface, the adhesive strength can be increased without impairing the rubber physical properties.
[0010]
The invention according to claim 2 is the rubber composite according to claim 1,
A groove extending along the periphery of the rubber member is formed in the adherent member,
The groove is provided with a sealing material that covers the adhesive interface between the rubber member and the adherend member from the side.
[0011]
Therefore, in the case of this invention, since the sealing material prevents oil from penetrating into the adhesive interface between the rubber member and the adherend member, peeling of the rubber member is more reliably prevented. become.
[0012]
The invention according to claim 3 is a method for producing a rubber-based composite in which a rubber member is vulcanized and bonded to an adherend member formed of metal or synthetic resin,
An unvulcanized rubber material for forming the rubber member is stacked on the adherend member via an adhesive,
By pressing a hot platen having a molding surface for vulcanizing and molding the rubber member and a protrusion extending along the periphery of the molding surface onto the adherend member from above the unvulcanized rubber material,
While the unvulcanized rubber material is heated on the molding surface, a groove is formed in the adherend member by the protrusion, and the adhesive is heated from the side by the protrusion, so that the rubber member, the adherent member, The cross-linking density of the adhesive at the peripheral portion of the adhesive surface is higher than the cross-linking density of the adhesive at the central portion of the adhesive surface.
[0013]
Therefore, according to the present invention, since the groove along the periphery of the unvulcanized rubber material is formed in the adherend member by the protrusion that is a part of the hot platen, the unvulcanized rubber material and the adherend are formed. The adhesion interface with the member can be directly heated from the side surface by the protrusion. Therefore, the crosslink density of the adhesive existing at the peripheral edge portion of the adhesive interface is higher than that of the central portion and is cured. And the strong adhesive force which prevents the penetration | invasion of oil between the peripheral part of a rubber member and a to-be-adhered member is obtained by hardening of this adhesive peripheral part.
[0014]
When an unvulcanized rubber material is stacked on an adherent member via an adhesive, the adhesive is applied to the adhesive surface of the rubber member of the adherend member, the unvulcanized rubber material is stacked thereon, and then a heating plate A method in which an unvulcanized rubber material is applied on top of the rubber member, an adhesive is applied to the adhesion surface of the rubber member of the adherend member, and a hot platen is placed on the adherend member to form a molding surface of the hot platen and the adherend member. Any method of forming a rubber member molding cavity in between and then injecting an unvulcanized rubber material into the cavity can be employed.
[0015]
In addition, in the case where a continuous protrusion is formed on the periphery of the molding surface of the hot platen over the entire circumference, the groove is formed by biting the projection into the adherend member. The space between the contact member and the adhesive member is securely sealed over the entire periphery, and the adhesive and the unvulcanized rubber material will not leak from the periphery of the molding surface. This means that for the adhesive, the peripheral portion is also pressurized at a high pressure as in the central portion, and this is advantageous in increasing the cross-linking density of the peripheral portion in combination with the heating by the protrusions. To work. In addition, since the pressure is uniformly applied to the entire unvulcanized rubber material, it works advantageously in obtaining a homogeneous rubber member.
[0016]
In addition, the rubber-type composite_body | complex which concerns on Claim 1 is not restricted to the said manufacturing method, For example, it can manufacture also with the following method.
[0017]
That is, it
An unvulcanized rubber material for forming the rubber member is stacked on the adherend member via an adhesive,
After performing the vulcanization molding of the rubber member by pressurizing and heating the unvulcanized rubber material,
By heating the adhesive interface between the rubber member and the adherend member from the periphery of the rubber member,
The crosslink density of the adhesive at the peripheral edge of the adhesive surface between the rubber member and the adherent member is made higher than the crosslink density of the adhesive at the central portion of the adhesive surface.
[0018]
Therefore, according to this method, the cross-linking density of the adhesive at the peripheral edge of the adhesive surface can be made higher than that at the central portion of the adhesive surface by local heating after vulcanization molding.
[0019]
【The invention's effect】
As described above, according to the invention relating to the rubber-based composite of this application, the adhesive between the rubber member and the adherend member has a cross-linking density at the peripheral portion of the adhesive surface rather than a cross-link density at the central portion of the adhesive surface. Therefore, even if the rubber-based composite is exposed to an oil atmosphere, it is difficult for the oil to enter the adhesive interface between the rubber member and the adherent member, and the rubber physical properties required for the rubber member The rubber member can be prevented from peeling without impairing the resistance.
[0020]
Further, according to the adherend member, a groove extending along the periphery of the rubber member is formed, and a sealing material that covers the adhesive interface between the rubber member and the adherend member from the side is provided in the groove. The entry of oil into the bonding interface is hindered by the sealing material, which is advantageous for preventing the rubber member from peeling off.
[0021]
Further, according to the invention relating to the method for producing a rubber-based composite of this application, a protrusion extending along the periphery of the molding surface is provided on the heating plate for vulcanization molding of the rubber member, and the projection is attached to the adherend member by the protrusion. Since the groove is formed and the adhesive between the unvulcanized rubber material and the adherend member is heated from the side surface by the projection, the cross-linking density of the adhesive at the peripheral portion of the adhesive surface is set at the central portion of the adhesive surface. It becomes easier to increase the cross-linking density of the adhesive.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
<Embodiment 1>
FIG. 1 shows a rubber-based composite 1, which is used in a state where it is immersed in automobile brake oil, and a rubber member 2 is bonded to the surface of a metal plate-like adherent member 3 with an elastomeric adhesive. It is vulcanized and bonded via an agent. As shown in an enlarged view in FIG. 2, a groove 4 having a V-shaped cross section is formed in the adherend member 3 along the peripheral edge of the rubber member 2 over the entire circumference. The groove 4 is filled with a sealing material 5 that covers the adhesive interface between the rubber member 2 and the adherend member 3 from the side. In this case, the sealing material 5 is provided so as to straddle the main body (a portion excluding the adhesive 2 a) of the rubber member 2 and the adherend member 3 with the adhesive 2 a interposed therebetween.
[0024]
The cross-linking density of the adhesive 2 a is higher at the peripheral portion of the adhesive surface than at the central portion of the adhesive surface between the rubber member 2 and the adherend member 3. The sealing material 5 is a butadiene-based elastic sealing material having an isocyanate group.
[0025]
FIG. 3 shows a mold for producing the rubber composite 1. In the figure, 6 is a lower mold (heat plate), and 7 is an upper mold (heat plate). A recess 8 into which the adherend member 3 is fitted is formed on the upper surface of the lower mold 6. A molding surface 9 for molding the rubber member 2 is formed on the upper die 7, and a lower portion for forming the groove 4 on the periphery of the molding surface 9 as shown in FIG. A protrusion 10 having a V-shaped cross section projecting toward the top is formed continuously over the entire circumference. Further, a hole 11 is formed in the center of the upper die 7 to allow air and rubber to escape in the cavity during molding.
[0026]
In the production of the rubber composite 1, first, the surface of the adherend member 3 is undercoated and overcoated with the adhesive 2a, and the unvulcanized rubber is overlaid thereon. This is supported by being fitted in the recess 8 of the lower die 6, and the heated upper die 7 is lowered and pressed against the lower die 6. The temperature of the upper mold 7 is, for example, 150 to 160 ° C., and the pressing time is, for example, 2 to 3 minutes.
[0027]
As a result, the unvulcanized rubber is molded into a product (rubber member 2) shape by the molding surface 9 of the upper mold 7, and is heated from the surface by the heat from the molding surface 9 so that vulcanization proceeds. Further, the protrusion 10 following the periphery of the molding surface 9 is pressed against the surface of the adherend member 3 at the periphery of the unvulcanized rubber to form a groove 4, and the unvulcanized rubber and the adherent member 3 The adhesive interface is directly heated from the side (from the side).
[0028]
That is, the portion of the upper mold 7 that extends from the molding surface 9 to the protrusion 10 comes into contact with the bonding interface from the side and directly heats the peripheral edge of the layer of the adhesive 2a. Vulcanization proceeds efficiently. Further, the side surface of the protrusion 10 heats the side surface of the groove 4 of the adherend member 3, and the heat of the protrusion 10 is transmitted to the peripheral portion of the layer of the adhesive 2 a through the adherend member 3. The vulcanization of the peripheral portion proceeds efficiently. On the other hand, since the central portion of the adhesive surface, that is, the central portion of the layer of the adhesive 2a is heated by heat transfer from the unvulcanized rubber surface, the progress of vulcanization is slower than the peripheral portion of the adhesive surface.
[0029]
Also, the adhesive 2a layer is sealed around by fitting the protrusions 10 and the grooves 4 (biting the protrusions 10), and there is no escape space when pressurized, so the peripheral part is the same as the central part. Therefore, vulcanization of the adhesive 2a at the peripheral portion proceeds efficiently. Moreover, since the whole unvulcanized rubber material is also uniformly pressurized, it is easy to finish the homogeneous rubber member 2.
[0030]
Therefore, in the obtained rubber-based composite 1, the crosslinking density at the peripheral portion of the adhesion surface of the rubber member 2 is higher than the crosslinking density at the central portion of the adhesion surface. In this case, the adhesive strength (peeling resistance) of the peripheral edge of the rubber member 2 is set to be 5 to 6 times that of the central portion.
[0031]
After that, the sealing material 4 is filled in the groove 4 so as to cover the adhesive interface and cured.
[0032]
Accordingly, even if the rubber-based composite 1 is immersed in the brake oil for a long time, the sealing material 5 prevents the brake oil from entering the adhesive interface. Further, even when the brake oil enters from the periphery of the sealing material 5 and reaches the periphery of the adhesive interface, the crosslinking density of the adhesive 2a at the peripheral portion of the adhesive surface is high, and the rubber member 2 exerts a strong force on the adherend member 3. Since it is bonded, the brake oil cannot enter the bonding interface. For this reason, the state in which the rubber member 2 is bonded to the adherend member 3 is maintained for a long time.
[0033]
In addition, when the unvulcanized rubber material is stacked on the adherend member 3 via the adhesive 2 a, the adhesive 2 a is applied to the rubber member adhesion surface of the adherend member 3 and the upper die 7 is covered on the adherend member 3. Then, after forming a rubber member molding cavity between the molding surface 9 of the upper mold 7 and the adherend member 3, a method of injecting an unvulcanized rubber material into the cavity can be employed. In that case, a rubber material injection hole is separately formed in the central portion of the upper mold 7 and an unvulcanized rubber material is injected into the cavity from the injection hole.
[0034]
<Embodiment 2>
In this configuration, the groove 4 as described above is not formed, and the crosslink density at the peripheral portion of the adhesive surface of the rubber member 2 is made higher than the crosslink density at the central portion of the adhesive surface. The method is as follows.
[0035]
That is, in this embodiment, the upper die 7 shown in FIG. 3 is a mold having no protrusions, and the rubber member 2 shown in FIG. 5 is vulcanized and bonded to the adherend member 3 in the same manner as in the first embodiment. A system complex 1 is obtained. Thereafter, the peripheral edge portion of the adhesive interface between the rubber member 2 and the adherend member 3 of the rubber composite 1 is locally heated from the periphery of the rubber member 2 by an electron beam or other local heating means 12.
[0036]
Accordingly, the obtained rubber-based composite 1 has a higher cross-linking density of the adhesive at the peripheral portion of the adhesive surface between the rubber member 2 and the adherend member 3 than in the central portion of the adhesive surface, as in the first embodiment. Thus, the peel resistance of the rubber member 2 is increased as in the first embodiment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a rubber-based composite according to Embodiment 1 of the present invention.
FIG. 2 is an enlarged sectional view showing a part of the rubber-based composite.
FIG. 3 is a cross-sectional view showing a mold for producing the rubber-based composite.
FIG. 4 is an enlarged sectional view showing a part of the mold.
FIG. 5 is a cross-sectional view showing a locally heated state after vulcanization molding of a rubber-based composite according to Embodiment 2 of the present invention.
[Explanation of symbols]
1 Rubber Composite 2 Rubber Member 2a Adhesive 3 Adhering Member 4 Groove 5 Sealing Material 6 Lower Mold 7 Upper Mold 8 Recess 9 Molding Surface 10 Projection 12 Local Heating Means

Claims (3)

A rubber-based composite formed by vulcanizing and bonding a rubber member to an adherent member formed of metal or synthetic resin,
A rubber-based composite in which the crosslink density of the adhesive at the peripheral portion of the adhesive surface is higher than the crosslink density of the adhesive at the central portion of the adhesive surface between the rubber member and the adherent member. In the rubber-based composite according to claim 1,
A groove extending along the periphery of the rubber member is formed in the adherent member,
A rubber-based composite in which a sealing material that covers the adhesive interface between the rubber member and the adherend member from the side is provided in the groove. A method for producing a rubber-based composite in which a rubber member is vulcanized and bonded to an adherent member formed of metal or synthetic resin,
An unvulcanized rubber material for forming the rubber member is stacked on the adherend member via an adhesive,
By pressing a hot platen having a molding surface for vulcanizing and molding the rubber member and a protrusion extending along the periphery of the molding surface onto the adherend member from above the unvulcanized rubber material,
While the unvulcanized rubber material is heated on the molding surface, a groove is formed in the adherend member by the protrusion, and the adhesive is heated from the side by the protrusion, and the rubber member and the adherent member are The manufacturing method of the rubber-type composite which raises the crosslinking density of the adhesive agent of the adhesive surface peripheral part of this to the crosslinking density of the adhesive agent of the adhesive surface center part.

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