JP2002154122A - Method for manufacturing vulcanized rubber product having excellent fuel oil resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a vulcanized rubber product having an interface releasability resistance in an atmosphere existing a fuel oil such as a gasoline fuel oil, an alcohol mixed fuel oil or the like as a vapor or the like, that is, an excellent fuel oil resistance. SOLUTION: A method for manufacturing the vulcanized rubber product 10 comprises the steps of coating a vulcanizing adhesive for rubber on a rigid member 12, integrally forming an unvulcanized body rubber 12 made of an NBR rubber material with the adhesive coating surface of the member 12, then vulcanizing the rubber 12, and further thereafter heat treating the rubber at 120 to 200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vulcanized rubber product having excellent fuel oil resistance, and more particularly to a method for manufacturing a vulcanized rubber product having excellent resistance to interface in an atmosphere in which fuel oil such as gasoline fuel oil or alcohol-mixed fuel oil exists as steam. The present invention relates to a vulcanized rubber product excellent in peelability and suitably used for a fuel system or the like.

[0002]

2. Description of the Related Art Conventionally, a rubber member having excellent properties such as viscoelasticity and cushioning property as well as flexibility and elasticity as a main rubber is integrally vulcanized and bonded to a rigid member such as a steel material. The obtained rubber products have been widely used in various fields. For example, in a vehicle such as an automobile or a mechanical facility, a vibration-proof rubber that is interposed between members of a vibration or shock transmission system and exhibits vibration-proof or cushioning properties,
Such a rubber product is suitably used, and reliability and durability are improved.

By the way, such a rubber product generally forms an unvulcanized rubber member after a vulcanizing adhesive for rubber is applied to a bonding portion of the rigid member with the rubber member, Then, the vulcanizing operation is performed and the rubber member is vulcanized and adhered to the rigid member, whereby the rigid member and the rubber member are firmly adhered to each other and are integrally formed.

[0004] However, even such an integrally bonded rubber product which is firmly adhered to, comes into contact with liquid or vapor fuel oil in a fuel system such as a fuel tank or an intake manifold. When applied to a portion that is easily damaged, the action of the fuel oil causes the bonded portion between the rigid member and the rubber member to deteriorate, and peeling occurs at the interface (bonding surface) between the rigid member and the rubber member. There was a problem that it became easier.

[0005]

The present invention has been made in view of such circumstances, and a problem to be solved is that fuel oil such as gasoline fuel oil or alcohol-mixed fuel oil exists as steam or the like. An object of the present invention is to provide an effective method for producing a vulcanized rubber product having excellent interfacial peeling resistance in an atmosphere, that is, excellent fuel oil resistance.

[0006]

The present inventors have made intensive studies to solve such a problem, and as a result, formed a main rubber using an NBR-based rubber material, and carried out a vulcanization operation thereof. It has been found that the adhesion between the rigid member and the main rubber can be effectively improved by performing a predetermined heat treatment after performing the vulcanization bonding to the predetermined rigid member.

Accordingly, the present invention has been completed based on such findings, and the gist of the present invention is that
When manufacturing a vulcanized rubber product in which a main rubber made of a BR rubber material is vulcanized and bonded to a predetermined rigid member, a surface of the rigid member to which a rubber vulcanizing adhesive is applied is applied. After integrally forming an unvulcanized main rubber made of an NBR-based rubber material, the main rubber is vulcanized, and the main rubber is vulcanized and bonded to the rigid member. A method for producing a vulcanized rubber product having excellent fuel oil resistance, characterized by performing a heat treatment at a temperature of 200 ° C.

As described above, in the method for producing a vulcanized rubber product excellent in fuel oil resistance according to the present invention, an NBR rubber material having oil resistance is used as the main rubber, while such an NBR rubber material is used. The body rubber made of rubber material
Simultaneously with the vulcanizing operation, a vulcanizing adhesive for rubber is integrally vulcanized and adhered to the applied rigid member, and thereafter, a predetermined heat treatment is performed, so that For rubber products manufactured in this way, even if gasoline, alcohol-mixed fuel, diesel fuel, fuel oil such as fuel kerosene, etc. come in contact, the fuel oil will cause the rubber body to swell or dissolve. The problem of the change in the properties of the rubber, such as the occurrence of such a problem, is not caused, and the adhesive force between the rigid member and the main rubber can be advantageously improved.
Is effectively suppressed, and thereby excellent fuel oil resistance or adhesion reliability can be sufficiently ensured.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method according to the present invention as described above is advantageously applied to the manufacture of a vibration-proof rubber 10 as a vulcanized rubber product as shown in FIG. 1, for example. is there. In this case, a vibration-isolating rubber 10 is a thick disk-shaped body rubber made of an NBR-based rubber material between plate-shaped rigid members 12, 12 which are arranged opposite to each other and have a disk shape made of iron, resin, or the like. 14 is bonded to the rigid members 12 and 12 by vulcanization, so that the rigid members 12 and 12
Has an integrated structure elastically connected.

When manufacturing the vibration damping rubber 10 having such a configuration, first, a predetermined rubber vulcanization is applied to the surfaces (vulcanization bonding surfaces) of the rigid members 12, 12 facing the main rubber 14. The sulfur adhesive is applied and the rigid member 1
The unvulcanized main rubber 14 made of NBR rubber is integrally formed on the surface on which the rubber vulcanizing adhesives 2 and 12 are applied. Next, the main body rubber 1
4, the main rubber 14 is vulcanized and formed, and at the same time, the main rubber 14 and the rigid members 12 and
12 are vulcanized and adhered. Thereafter, by further performing a predetermined heat treatment, the anti-vibration rubber 10 capable of exhibiting desired characteristics is formed.

The anti-vibration rubber 10 manufactured according to the present invention has an intended anti-vibration or cushioning performance by being interposed between two members constituting a vibration transmission system and an impact transmission system. This is shown in FIG.
Reference numeral 6 denotes mounting bolts for separately mounting and fixing the rigid members 12, 12 of the anti-vibration rubber 10 to each of the two predetermined members.

Here, when manufacturing the vibration-proof rubber 10 according to the method of the present invention, the application of the vulcanizing adhesive for rubber to the rigid members 12, 12 is carried out in the same manner as in the prior art. A vulcanized rubber adhesive is generally applied so as to cover the entire surface of the bonding surface between the main rubber 14 and the rigid member 12. In addition, such a main body rubber 1
The adhesive used for bonding between the rigid member 4 and the rigid member 12 is not particularly limited, and various conventionally known vulcanizing adhesives for rubber, for example, a chlorinated rubber-based adhesive and a phenol resin-based adhesive can be used. An adhesive made of a thermosetting rubber or resin such as an adhesive or an isocyanate-based adhesive is used as the rigid member 1
It can be used depending on the materials 2 and 12, the compounding composition of the main rubber 14, and the like. However, in order to ensure the desired properties in the present invention, it is desired to use an adhesive having excellent oil resistance, and among them, particularly, a thermosetting chlorinated rubber-based adhesive and a phenolic resin-based adhesive are preferred. Alternatively, a combination thereof is suitably adopted. By adopting such a vulcanized adhesive for rubber, it is possible to more advantageously secure the adhesion between the main rubber 14 and the rigid member 12 on the bonding surface.

Further, a main rubber 14 made of an unvulcanized rubber composition is integrally formed on the surface of the rigid member 12 to which the predetermined vulcanizing adhesive has been applied as described above, Then, vulcanization molding and vulcanization bonding operations will be performed.In performing such vulcanization, various general methods can be appropriately adopted, for example, using a vulcanization molding die. Then, rigid members 12, 12 coated with a predetermined vulcanizing adhesive for rubber are arranged at predetermined positions in the molding cavity, and an unvulcanized NBR system is placed in the molding cavity of the molding die. By filling a rubber composition made of a rubber material and integrally forming the main rubber 14 into a desired shape, by performing a vulcanizing operation of the main rubber 14,
At the same time as the vulcanization molding, a method of vulcanizing and bonding the rigid members 12 and 12 with the main rubber 14 and a method of uncuring the rigid members 12 and 12 to which a predetermined rubber vulcanizing adhesive has been applied. A method of vulcanizing and bonding the main rubber 14 formed in a desired shape in advance using a rubber composition made of a sulfuric NBR-based rubber material will be adopted.

Incidentally, in the vulcanizing operation of the main body rubber 14,
The vulcanization conditions that have been generally adopted
Time and temperature conditions will be appropriately adopted. Like
In general, using a vulcanization tester such as a rheometer
When a vulcanization curve is created by performing a vulcanization degree test on rubber
At a torque equivalent to 90% of the maximum torque.
Time: T₉₀Is the appropriate vulcanization time, and in the present invention
It is most desirable to adopt such an appropriate vulcanization time.
Preferably, the present invention provides such an appropriate vulcanization time.
The torque is not limited to any
75% to 100% of the maximum value, with 90% of the
For giving torque equivalent to: T₇₅~ T_{Ten 0} smell
Thus, a vulcanization operation is performed. And like this
The vulcanization operation allows vulcanization of the main rubber 14 as well as
And bonding between the main rubber 14 and the rigid members 12
It can be done. Thus, such a vulcanization operation
Between the body rubber 14 and the rigid members 12
As mentioned earlier, the adhesive properties are measured under the condition of contact with fuel oil.
But it was still inadequate.

Therefore, in the present invention, in order to realize the desired excellent fuel oil resistance, a predetermined heat treatment is further performed after the above-mentioned vulcanization operation. This heat treatment is performed by further heating the anti-vibration rubber 10 on which a normal vulcanization operation has been performed in a heating device such as an oven, whereby the bonding between the rigid member 12 and the main rubber 14 is performed. Therefore, the peeling at the interface between the main rubber 14 and the rigid members 12, 12 in a state where the fuel oil is in contact can be advantageously prevented. Although the mechanism for improving the adhesiveness has not been elucidated yet, such a heat treatment may cause the rigid member 1 to lose its rigidity.
It is presumed that the vulcanizing adhesive interposed between the rubber 2 and the main rubber 14 is activated by some action, thereby significantly improving the bonding property.

Here, in the heat treatment required in the present invention, a temperature range of 120 ° C. to 200 ° C. is adopted in order to sufficiently achieve the object. However, if the temperature is lower than 120 ° C., the effect of improvement cannot be obtained to justify the heat treatment, and the interface separation is still caused under the contact of the fuel oil. If a temperature exceeding 200 ° C. is employed, not only does the cost rise, but also the main rubber 14 and the adhesive are deteriorated.

The processing time for such a heat treatment is not particularly limited, and may be appropriately set according to the heat treatment temperature.
0.5 to 48 hours are employed, whereby practical productivity can be achieved with improved properties. If the processing time is less than 0.5 hour,
This is because the improvement of the adhesiveness cannot be advantageously achieved, while if it exceeds 48 hours, not only the productivity is deteriorated, but also the main rubber 14 and the adhesive may be deteriorated. .

In the present invention, the vibration isolating rubber 10
In the rubber composition that provides the main rubber 14 constituting the rubber composition, an NBR (acrylonitrile-butadiene rubber) rubber material having excellent oil resistance is particularly preferably used as a rubber material.
The BR (hydrogenated NBR) material is employed, so that even when fuel oil such as gasoline, alcohol-mixed fuel, diesel fuel, and fuel kerosene contacts the main rubber 14, the main rubber 14 swells. , Etc. can be very advantageously prevented. In addition, in addition to the NBR-based rubber material, various rubber materials such as natural rubber and diene-based synthetic rubber, which are excellent in anti-vibration properties and durability, can be used in the above-mentioned rubber composition without problems such as expansion. It is also possible to mix in the range.

For such NBR-based rubber materials, various known materials such as a reinforcing agent, a softening agent, a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator and an antioxidant can be used in the same manner as before. It is also possible to appropriately mix the rubber compounding agent as required. Among them, vulcanizing agents which are one of such compounding agents for rubber include various vulcanizing agents conventionally known as vulcanizing agents for NBR-based rubbers, such as sulfur-based vulcanizing agents and peroxide-based vulcanizing agents. It is possible to adopt, such a vulcanizing agent is appropriately selected, it will be used in an appropriate amount according to the amount of rubber material used, especially as such a vulcanizing agent, By using a peroxide-based vulcanizing agent such as dicumyl peroxide or di-t-butylperoxydiisopropylbenzene, the settling resistance of the main rubber 14 can be improved.

Further, as the rigid member 14 constituting the vibration isolating rubber 10, any known material having rigidity and oil resistance can be used, and a metal material such as iron or aluminum can be used. It is also possible to use a material made of a resin material. The rigid member 1 made of a metal material
In the case of employing No. 4, it is needless to say that those whose corrosion resistance has been improved by various conventionally known methods such as chemical conversion coating treatment can be suitably used.

As described above, the anti-vibration rubber 10 manufactured according to the present invention uses an oil-resistant NBR-based rubber material as the main rubber 14, and further after the normal vulcanization thereof. Even if a liquid or gaseous (steam) fuel oil comes into contact with a part where the predetermined heat treatment is performed, such a fuel oil swells or dissolves the 14 parts of the main rubber. In addition to the above, the problem of the change in the properties of the rubber is not caused, and the bonding state between the rigid member 12 and the main rubber 14 can be advantageously secured, and the occurrence of peeling at the interface (adhesive layer) therebetween is effective. Thus, excellent fuel oil resistance or adhesion reliability can be effectively realized.

The method of the present invention can be applied to any vulcanized rubber product as long as rubber is integrally vulcanized and bonded to a member made of a rigid material such as a metal material or a resin material. Needless to say, it is possible and the application object is not limited to the example of the vibration-proof rubber at all. Further, the vulcanized rubber product manufactured by such a method of the present invention is extremely advantageous particularly in a fuel system such as a fuel tank or an intake manifold, in other words, in an atmosphere where fuel oil exists as steam or the like. It can be adopted.

Further, even in the case of manufacturing a vibration-proof rubber by applying the method of the present invention, the specific configuration of the vibration-proof rubber is as follows.
It is by no means limited to the example, and for example, the rigid member 12 constituting the vibration isolating rubber 10 is
In addition to the above-mentioned disk-shaped one, an elliptical shape, a square shape, a polygonal shape such as a pentagon, or a shape having a V-shaped cross-section that is gradually depressed toward the center, is also formed into various shapes. The bracket may be any shape, or may be a cylindrical or bush-type anti-vibration rubber. Further, the mounting bolts 16 are not essential, and are provided as needed.

[0024]

Hereinafter, typical examples of the present invention will be described to clarify the present invention more specifically. However, the present invention imposes no restrictions on the description of such examples. It goes without saying that you don't receive anything. In addition, in addition to the following examples, the present invention may further include various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention. , Improvements and the like can be added.

-Preparation of Test Piece- First, in order to prepare test pieces specified in "5. 90 degree peeling test of metal piece and rubber" in JIS-K-6256-1993, respectively, A rubber composition having a compounding composition was prepared. In addition, as a rubber material, hydrogenated acrylonitrile-butadiene rubber (H-
NBR), while the compounding agent for rubber includes a vulcanizing agent (peroxide): Peroximon F-40 (manufactured by Nippon Oil & Fats Co., Ltd.), an antioxidant: Nowguard 445 (USA: manufactured by Uniroyal Corporation), and a softening agent Agent: Thiokol TP95
(USA: manufactured by Thiokol Chemical Co., Ltd.). H-NBR 100 parts by weight Carbon black 50 parts by weight Vulcanizing agent 6 parts by weight Antioxidant 1 part by weight Softening agent 5 parts by weight

Next, a degreased iron plate is used as a metal piece, a phenolic resin-based vulcanizing adhesive is primed on its bonding surface, dried with hot air, and then another chlorinated rubber-based vulcanizing adhesive is used. After overcoating and drying with hot air, the uncured product composed of the rubber composition obtained above was applied to the adhesive surface coated with the adhesive under the vulcanization conditions shown in Table 1 below. After press vulcanization to integrally form a main rubber layer having a predetermined thickness, the heat treatment conditions shown in Table 1 are further employed to carry out a predetermined heat treatment, whereby JIS-
K-6256-1993 "Adhesion test method for vulcanized rubber"
, Test pieces according to Examples 1 to 5 of the present invention and Comparative Examples 1 to 3 as specified in “5. 90 ° Peeling Test of Metal Piece and Rubber”. The bonding area of the bonding surface was set to 25.4 mm × 25.4 mm (1 inch × 1 inch). When the rubber hardness (JIS A) of the obtained test piece was measured,
Both were approximately 60.

Of the test pieces thus produced, each of the test pieces of Examples 3 to 5 of the present invention and Comparative Example 3 was used as a standard fuel oil: Fuel D kept at 40 ° C.
While the test pieces of Inventive Example 2 and Comparative Example 2 were kept in a saturated steam atmosphere of Fuel D at 40 ° C. for 120 hours.

[0028]

[Table 1]

-90-degree peel adhesion test- Examples 1 to 5 of the present invention and Comparative Examples 1 and 2 obtained as described above.
JIS-K-6256- using each test piece of No. 3
In accordance with the test method specified in the above-mentioned “5. 90 ° Peeling Test of Metal Piece and Rubber” in 1993, the main rubber layer adhered to the iron plate is pulled in a direction of 90 ° with respect to the iron plate to be peeled off. The maximum value of the peeling force required for (1) was determined, and the result was shown in Table 2 below as an adhesive force. On the other hand, by observing the state of the peeled portion, the interface peeling ratio was obtained. Note that the interfacial peeling rate refers to the damage of the test piece due to "breakage in the main rubber layer" and "breakage in the adhesive layer between the iron plate and the main rubber layer" caused by performing a 90-degree peel adhesion test. It shows the ratio of "breakage in the adhesive layer" in the situation. For example, an interface peeling rate of 100% means that peeling occurred only at the adhesive interface between the iron plate and the rubber member. You can understand.

[0030]

[Table 2]

As is clear from the results in Table 2,
Under the condition that the fuel oil does not come into contact, the test piece not subjected to the heat treatment (Comparative Example 1) is also the same as the test piece subjected to the heat treatment (Example 1 of the present invention) at the interface between the iron plate and the rubber member. It can be seen that no peeling occurred. However, even if the test pieces are vulcanized under the same vulcanization conditions, the test pieces that have not been subjected to the heat treatment (Comparative Examples 2 and 3) will not come into contact with the fuel oil vapor or liquid. The adhesion between the iron plate and the rubber member is weakened, and the rate of occurrence of peeling at the interface (adhesive layer) is increased as compared with the heat-treated test pieces (Examples 2, 3 to 5 of the present invention). You can see what is being done. It is also understood that by appropriately setting the conditions of the heat treatment, it is possible to reduce the interfacial peeling rate and secure sufficient bonding reliability.

[0032]

As is clear from the above description, in the method for producing a vulcanized rubber product excellent in fuel oil according to the present invention, the adhesive force between the rigid member and the main rubber can be effectively increased. In addition, a decrease in the adhesive force between the rigid member and the main rubber in an atmosphere in which the fuel oil exists as steam or the like can be extremely advantageously prevented or suppressed. Therefore, a vulcanized rubber product that can realize excellent interfacial peeling resistance and adhesion reliability can be produced extremely advantageously.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a vulcanized rubber product to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Anti-vibration rubber 12 Rigid member 14 Body rubber 16 Mounting bolt

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 9:00 B60K 15/02 (72) Inventor Toshiyuki Mihara 1-3-1, Higashi 3-chome, Komaki City, Aichi Prefecture Tokai Rubber Industries (72) Inventor Tomoyasu Arase 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3D038 CC19 3J048 AA01 BD04 BD07 EA07 4F100 AB01B AB01C AB03 AK27A AK29A AL01A AN02A AN02G AT00B AT00C BA03 BA06 BA10 BA10 BA10C CA03 CB00 EJ202 EJ862 GB32 JK06 4F203 AA46 AD34 AE07 AR06 DA11 DB11 DC01 DF01 DF05 DK07 DW06

Claims (1)

[Claims] When manufacturing a vulcanized rubber product in which a main rubber made of an NBR rubber material is vulcanized and bonded to a predetermined rigid member, a vulcanizing adhesive for rubber of the rigid member is applied. After integrally forming an unvulcanized main rubber made of an NBR-based rubber material on the surface formed, vulcanization of the main rubber is performed, and vulcanization bonding of the main rubber to the rigid member is performed. After that, 120 to 20
A method for producing a vulcanized rubber product having excellent fuel oil resistance, comprising performing heat treatment at a temperature of 0 ° C.