JPH0913008A - Sealing material and pipe fitting - Google Patents

Abstract

PURPOSE: To obtain a sealing material which can prevent machine components or pipes made of copper or its alloy from suffering from corrosion or erosion- corrosion under submarine conditions. CONSTITUTION: This rubbery sealing material is prepared by incorporating or adhering 0.005-0.10 pt.wt. at least one organic heterocyclic compound selected from among benzotriazole, triazole, alkyloxybenzotriazoles or benzimidazole in a base material or to its surface. The base material is a rubber prepared by mixing an ethylene/propylene rubber with its diene compound and contains 0.1-0.5 pt.wt. at least one member selected from among phthalyl dihydrazide, isophthalyl dihydrazide and terephthalyl dihydride. It is also possible to add a nondrying polymeric substance containing a nondrying oil added and kneaded together with 70-95wt.% fine zinc powder. The nondrying oil is the one prepared by adding polyethylene glycol, lauryl ether or polyoxyethylene sorbitan as a stabilizer to castor oil, olive oil or a hydrocarbon oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing material and a pipe joint, and more particularly to a sealing material and a pipe joint which are suitable for preventing corrosion of a seawater pump made of copper or a copper alloy and a fluid transportation pipe.

[0002]

BACKGROUND OF THE INVENTION Steam returning from a steam turbine is either reheated for reuse or is directed to a condenser to be cooled and returned to distilled water. A large amount of seawater is used to cool the steam in the condenser. Usually, the introduction and drainage of seawater into the condenser are often performed by a stainless steel pump or pipe from the viewpoint of corrosion resistance. In addition, pumping pumps and pipes that are used while performing maintenance in a short period of time include anti-corrosion construction such as painting.

By the way, when using seawater, marine organisms inhabiting the seawater and bottom mud float and are taken into the pumps and pipes. For example, marine organisms such as mussels and barnacles attach to and grow on the impeller surface of pumping pumps and inside pipes. Marine organisms such as blue mussels and barnacles that adhere to the surface of the pump and the inner wall of the pipe not only hinder the flow velocity in the pipe due to the resistance of the seawater fluid, but also cause damage such as biting on the rotary shaft sealing part of the pump. There is a problem that causes it.

Although a method of injecting a halogen gas such as chlorine into a pipe is currently adopted as a means for suppressing the adhesion and reproduction of marine organisms, it is not effective but finally requires a large amount of personnel. The problem remains that the cost must be spent and mechanically scraped.

[0005]

As means for solving such a problem, a seawater contact surface of a pump or a pipe is a copper alloy having good seawater corrosion resistance, for example, 66 to 90% Cu,
If a copper alloy having a basic composition of 30 to 10% Ni is used, the problem of marine mussels, barnacles, and other marine organisms adhering to the surface is significantly reduced. In this respect, the damage caused by the attachment of marine organisms, which has been a problem in the prior art, is avoided.

On the other hand, in the case of copper and copper alloy pipes, brazing or welding must be used as the sealing method for the pipe connecting portions. Sealing the pipe connection by these methods makes maintenance of pumping pumps and pipes extremely difficult, and the construction cost thereof is significantly increased, making it impractical. Here, if a rubber packing or a rubber seal ring can be used as a sealing method for the pipe connection portion, the construction of the entire system can be performed relatively easily, and the maintenance thereof can also be performed easily.

However, in general, when a rubber packing or a rubber seal ring is brought into contact with copper and a copper alloy, it is feared that the rubber-like material gradually becomes brittle and causes water leakage. Rubber materials can be used in oxidizing environments such as seawater or at high temperatures.
As shown in the following formula (1), the radical main chain bridging the rubber molecules is oxidized to be a peroxide, and the rubber material tends to be brittle.

[0008]

[Image Omitted] RH → R + HR R + O ₂ → ROO ROO + RH → ROOH + R where R: radical (rubber molecule) RH: rubber molecule cross-linked with radical main chain ROOH: rubber molecule cross-linked with radical main chain ROO: It is a rubber molecule that has been converted to peroxide by oxidation.

When the rubber-like material is in contact with copper or a copper alloy, the eluted copper ions tend to accelerate the oxidation of the radical main chain as shown in the following formula (2). is there.

[0010]

Embedded image

Therefore, when the rubber-like material is in contact with copper or a copper alloy for a long period of time, deterioration is advanced, and as a result, water leakage from the sealing portion may occur. Particularly, in the case of a rubber cross-linked with a sulfur compound, such as nitrile butadiene rubber and styrene butadiene rubber, when the rubber molecular layer deteriorates, sulfurous acid, etc. may be added to the metal interface in contact with the rubber material. Are produced and the environment shifts to acidic. Of the environmental conditions that affect the corrosion of copper and copper alloys, pH is sensitive,
It is known that when the pH shifts to acidic, the corrosion of copper and copper alloys is significantly accelerated.

[0012] As described above, when copper or a copper alloy having a property that marine organisms are hard to attach is used for pump equipment or piping for handling seawater, the rubbery material does not deteriorate for a long period of time. A method of providing a rubber-like material with a function of preventing corrosion of copper and copper alloys is a technical problem to be solved. There are currently no examples that disclose these issues.

An object of the present invention is to provide a rubber-like sealing material which does not easily deteriorate even when contacted with copper or a copper alloy in a seawater environment, and to provide a stable compound on the surface of the copper and the copper alloy in contact therewith. A rubber sealing material with the function of forming a seal is installed on the curved portion of the bent pipe to prevent repeated erosion and corrosion, and to prevent corrosion in minute spaces and gaps such as flange sealing parts. It is to provide a pipe joint.

[0014]

In order to achieve the above object, the sealing material of the present invention comprises a benzotriazole, tritriazole, and alkoxyl benzotria in a rubbery substrate or on the surface of a rubbery substrate. It is characterized in that an organic heterocyclic low compound consisting of sol or benzimidazole is added individually or in a composite form and attached.

The low organic heterocyclic compound is 0.0
It is characterized in that 05 parts to 0.10 parts are added and adhered, and the rubber-like base material is a rubber obtained by blending ethylene propylene rubber with the diene compound thereof, and phthalyl dihydrazide and isophthalic acid are added thereto. It is characterized in that luji hydrazide or terephthalyl dihydrazide is blended individually or in a combination of 0.1 part to 0.5 part.

Further, benzotriazole, tritriazole, alkoxylbenzotriazole or benzo is added to a non-drying polymer substance containing non-drying oil which is obtained by kneading 70% to 95% of zinc fine powder. The present invention is characterized in that an organic heterocyclic low compound containing imidazole is added individually or in combination of 0.005 to 0.10 parts.

The non-drying oil is castor oil, olive oil or hydrocarbon oil, and polyethylene glycol, auryl ether, or polyoxyethylene sorbita is added as a stabilizer. To do. Further, the non-drying polymer substance containing the non-drying oil uses a surfactant such as ethylene ester or zinc stearate which is a simple substance or a complex of polybutene, polyalkylethylene glycol, or a derivative thereof. Is characterized in that.

Further, specifically, the following configuration is adopted. What is claimed is: 1. A sealing material comprising a rubber-based base material for corrosion prevention, which is used for equipment members made of copper or copper alloy, wherein the rubber-based base material is benzotriazole or tritriazole in the base material or on the surface layer of the base material. , An organic heterocyclic low compound consisting of alkylylbenzotriazole or benzimidazole, individually or in combination, and
It is characterized in that 5 to 0.10 parts are added and adhered.

Further, a sealing material made of a rubber-like base material for corrosion prevention used in equipment and piping made of copper or copper alloy used in a seawater environment, wherein the rubber-like base material is ethylene propylene rubber and its diene A rubber compounded with phthalyl dihydrazide, isophthalyl dihydrazide or terephthalyl dihydrazide as an antioxidant is added individually or in combination to give 0.1 part to 0.5 part. 0.005 parts by weight of an organic heterocyclic low compound consisting of benzotriazole, tritriazole, alkylylbenzotriazole or benzimidazole, individually or in combination, in the rubber base material or the surface layer thereof. Or 0.10 parts are added and adhered.

Further, it is a sealant for equipment and pipes mainly made of copper or copper alloy, and is a non-drying oil made of castor oil, olive oil or hydrocarbon oil, and polyethylene glycol, auryl ether or polyoxyethylene sol as a stabilizer. Vita was added, and zinc fine powder was added to 7
An organic heterocyclic low compound consisting of benzotriazole, tritriazole, alkylylbenzotriazole or benzimidazole is added to a non-drying polymer substance obtained by adding 0% to 95% and kneading, respectively, or a compound thereof. 0.005 part to 0.10 part is further added, and ethylene ester, zinc stearate, etc., which is a simple substance or a complex of polybutene, polyalkylethylene glycol or a derivative thereof, is added to the non-drying polymer substance. It is characterized by using the surfactant of.

[0021] Further, the above object is to provide a benzotriazole, tritriazole, alkoxyl benzotriazole, or a mixture thereof in a joint portion of a metal tube made of copper or a copper alloy, in a rubber base material or on a surface layer of a rubber base material. This is achieved by a pipe joint characterized in that an organic heterocyclic low compound composed of benzimidazole is added individually or in combination in an amount of 0.005 to 0.10 parts. Further, the rubber base material is attached as a sealing material to a curved pipe joint portion of the metal pipe or to a flange joint of the metal pipe.

Further, the pipe joint of the present invention comprises a non-drying polymer substance composed of castor oil, olive oil or hydrocarbon oil as a single substance or a complex, and benzotrifazole, tritriazole, alkoxylbenzotriazole or benzo. An organic heterocyclic low compound consisting of imidazole, individually or in combination, may be used in an amount of 0.005 to 0.10 parts.
The sealing material added in the section is used for a flange joint of a metal pipe made of copper or a copper alloy.

[0023]

[Function] Generally, when a rubber material is used in a seawater environment or a high temperature environment for a long period of time, the radical main chain bridging the rubber molecule tends to be oxidized and deteriorated. It has already been described that the oxidative action is promoted to cause embrittlement. For these things,
According to the constitution of the above-mentioned sealing material according to the present invention, benzotriazole, tritriazole, alloylbenzotriazole, and benzimidazole, which are low organic heterocyclic compounds contained in the rubber base material or in the surface layer thereof, are , Has a function of forming a hydrophobic and stable complex compound preferentially with copper or a copper alloy, thereby preventing crevice corrosion of copper or a copper alloy.

Further, it is assumed that the rubber base material is ethylene propylene rubber and the cross-linking of the rubber molecular layer is strengthened by oxidation, and isophthalyl dihydrazide or phthalyl dihydrazide is added as an antioxidant hydrogenated thereto. By combining them individually or in combination,
Before the bridging structure of rubber molecules becomes brittle due to oxidation in a seawater environment, the action of reducing them and maintaining them in a stable state occurs.

On the other hand, the non-drying high-polymer substance metal to which zinc fine powder is added and kneaded is effective when the gap between the equipment member and the pipe is so small that the rubber sealing material cannot be inserted. Corrosion protection is achieved by the water-repellent oil film, and benzotriazole, tritriazole, alkylylbenzotriazole, benzimidazole, etc., which are added as low-organic heterocyclic compounds, are stable complexes on the surface of the metal as the water gradually advances. A compound is formed to achieve corrosion protection. Further, the zinc fine powder is selectively dissolved to make the environment of the minute gaps alkaline to maintain the surface of the metal copper or copper alloy in a stable state.

Further, according to the above-mentioned structure of the pipe joint of the present invention, by installing the rubber sealing material on the equipment part or the pipe made of copper or copper alloy or the curved portion thereof, the erosion or corrosion of the pipe surface can be achieved. Can be prevented, and the anticorrosive action will be described below.

In a neutral water environment at room temperature, a tube made of copper or copper alloy has a thin and dense oxide film (Cu ₂ O) on its surface.
To prevent corrosion. The thermodynamic stability of these oxide films largely depends on the pH of environmental water and becomes extremely unstable as the pH changes from neutral to acidic, resulting in significant corrosion.

According to the pipe joint of the present invention, by covering with the above-mentioned rubber-based sealing material according to the present invention, the pipe surface is protected against crevice corrosion and the pipe is protected against corrosion. Erosion and corrosion of this portion can be prevented. Also, for large-diameter pipes, connection by a flange joint is simple and economical.

Here, when a commonly used rubber-like sealing material such as a vulcanizing agent for vulcanization or a crosslinking agent for chlorine is used as a sealing material for a flange joint made of copper or copper alloy, Although there is a problem that crevice corrosion may occur in the sealing portion and its surroundings, in the pipe joint made of copper or copper alloy of the present invention, for example, in the sealing portion of the flange joint, the rubber sealing according to the present invention. By sealing with a material or a non-drying polymer substance, a stable compound consisting of copper and, for example, benzotriazole, is formed on the surface of the copper or copper alloy in the sealing portion, and it acts to prevent corrosion of the underlying metal. Have

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show an embodiment of a sealing material of the present invention, in which FIG. 1A is a top view and FIG. 1B is a sectional view, in which a bolt hole 2 for fastening and a flow path 3 are formed in the sealing material 1. Has been done. In this example, in order to prevent crevice corrosion of copper or a copper alloy while suppressing the embrittlement of the rubber base material by copper, the rubber sealant 1 was added with benzotriazole as an organic heterocyclic low compound. It is attached.
Benzotriazole is a typical example of the low organic heterocyclic compound to be added and attached, and other derivatives such as tritriazole, alkylylbenzotriazole and benzimidazole are effective. Further, as the amount of these organic heterocyclic low compounds added and attached,
When the amount is 0.005 parts or less, the copper complex compound film thickness is small and there is no anticorrosion effect, and when it is 0.10 parts or more, it becomes uneconomical.
05 to 0.10 part is preferable.

As described above, when the rubber material is in contact with copper or a copper alloy for a long period of time, as a method for preventing the rubber material from becoming brittle, when the rubber molecular layer becomes a peroxide, It is advisable to add an antioxidant having an action of reducing or suppressing the above to the rubber base material. As such an antioxidant, for example, if phthalyl dihydrazide, isophthalyl dihydrazide, or terephthalyl dihydrazide is added as a hydrogenated metastable compound, the time to embrittlement becomes long. It is considered that these antioxidants prevent the rubber molecular layer from becoming a peroxide due to its reducing action. As will be described later, it has been found that the effect of simply adding isophthalyl dihydrazide as an antioxidant has no effect on the results of measuring the surface potential and surface roughness of copper.

By the way, as the rubber molecular layer which is cross-linked by peroxide, ethylene propylene rubber or ethylene propylene rubber mixed with a small amount of a diene compound (EPT) for improving the cross-linking property is used. desirable. As an example thereof, the above-mentioned ethylene propylene rubber, or a rubber base material in which a small amount of a diene compound (EPT) is mixed with ethylene propylene rubber to improve crosslinkability, is used as an antioxidant, and phthalyl dihydrazide or isophthalic acid is used. Ruji hydrazide and terephthalyl dihydrazide, individually or in combination, are 0.1 to 0.
Add 5 parts. If the content is less than 0.1 part, the effect is small, and if more than 0.5 part, it is uneconomical.
0.5 part is preferred.

The above-mentioned rubber base material is used in a seawater environment.
When it is in contact with copper or copper alloy for a long period of time, its embrittlement is suppressed, but it does not have the function of preventing corrosion of the contacting copper or copper alloy equipment or piping in this state. it is conceivable that. In the rubber sealing material according to the present invention, an organic heterocyclic low compound which forms a stable complex compound polymer with copper ions is added to and adhered to the rubber substrate in the rubber substrate or the surface layer portion thereof. When a copper or a copper alloy is brought close to or in contact with, a stable copper complex compound is formed on the surface of the copper or the copper alloy, and the function of preventing corrosion is added. As an organic heterocyclic low compound that forms a complex compound with copper or a copper alloy,
As described above, there are benzotriazole, tritriazole, alkylylbenzotriazole and benzimidazole having a hydrogen bond at the 1-position.

The copper ion forms a covalent bond by substituting hydrogen at the 1-position of the organic heterocyclic low compound, and forms a coordination bond with the lone electron pair of the nitrogen atom at the 3-position. The copper complex compound, which is inactive against corrosion, is formed in a net-like shape by alternately repeating and the coordinate bond. The present inventors have found that this is extremely effective in preventing crevice corrosion.

On the other hand, as another embodiment of the present invention, zinc fine powder is used in the joint of equipment members or pipes made of copper or copper alloy for sealing the minute gaps so that the rubber sealing material cannot be inserted. The mixture was added and kneaded to obtain a sealing material. This is 70% fine zinc powder as a sealing base.
The non-drying oil kneaded by adding ~ 95% is castor oil,
It is a non-drying high-molecular substance consisting of olive oil or hydrocarbon oil, to which benzotriazole, tritriazole, alkylylbenzotriazole, benzimidazole, etc., as organic heterocyclic low compounds, are used individually or in combination. Then, 0.005 to 0.10 part was added.

If the zinc fine powder content is 70% or less, no anticorrosive effect is provided, and if it is 95% or more, the sealing material itself loses plasticity and is impractical. Therefore, the amount of zinc fine powder added is 7%.
0 to 95% is preferable. When the amount of the organic heterocyclic low compound added is 0.005 parts or less, there is no anticorrosion effect and
Since it is uneconomical if it is 0 part or more, 0.005 to 0.10 part is preferable.

Here, in order to investigate the effect of the sealing material of the present invention, the test rubber materials shown in Table 1 were prepared.

[0038]

[Table 1]

Among these test rubber materials, the test rubber materials according to the present invention are test pieces No. 1 to No. 3. Among them, test pieces No. 1 to No. 3 are obtained by blending 0.005-0.10 part of benzotriazole with an ethylene-propylene rubber base material. Also, the test piece No.
No. 4 is the one to which only the antioxidant is added without adding the anticorrosive agent. Further, the test piece No. 5 is a non-drying material made of paraffin oil in which a surfactant such as polyethylene glycol, ethylene ester or zinc stearate added with 70% zinc fine powder is kneaded instead of the rubber sealing material. It is an anticorrosion sealing material in which 0.05 parts of benzotriazole as an organic heterocyclic low compound is added to a polymer substance. Further, the test pieces No. 6 to No. 8 are commercially available rubbery materials, which are styrene butadiene, nitrile butadiene and chloroprene rubber, respectively.

From these test rubber materials, as shown in FIG.
The sealing test piece 10 having the shape shown in FIG.
It was assembled into a pipe-shaped corrosion test piece as shown in FIG.
The ring 11 of the metal corrosion test piece was machined from a copper alloy composed of 90% copper and 10% nickel, and a lead wire 12 for measurement was connected to the end portion thereof. Further, while maintaining the artificial seawater shown in Table 2 at 25 ° C. on the inner surface of the crevice constituted by the ring 11 of the corrosion test piece, it was made to flow as a corrosion test water from the direction of the arrow by a pump and circulated for 2000 hours. .

[0041]

[Table 2]

After the immersion for 500 hours, the potential and polarization of the inner surface of the gap of the ring 11 were measured by the glass capillary 13 and the platinum counter electrode 14 in the ring 11. In order to prevent the test water from leaking from the flow channel, the plastic container 15 was sealed with the rubber cap 16 and the ring 11 was tightened with the bolt 17.

FIG. 3 shows the measurement results of the electrode potential. From the figure, the test piece No. with the conventional rubber sealing material attached.
In No. 6 and No. 8, the electrode potential hardly changed, but in the case where the test pieces No. 1 and No. 2 according to the present example were mounted, it was observed that the electrode potential shifted to the noble potential side with the holding time. . It is considered that this is because the benzotriazole eluted from the test piece of this example formed a stable complex compound (Cu-BTA) on the surface of the copper alloy, so that the surface potential thereof shifted to the noble potential side.

FIG. 4 shows an example of polarization measurement of the inner surface of the gap of the corrosion test piece. From the same figure, in the case where the test piece No. 2 of the present example is mounted, there is a tendency that the cathode polarization current density in the cathode polarization characteristic line increases with the holding time. It is considered that this is because the complex compound formed on the surface of the copper alloy is dissociated by the cathodic polarization as shown in the following formula (3).

[0045]

Embedded image

From this, it is considered that the complex compound formed on the surface of the copper alloy increases with the holding time. On the other hand, in the anodic polarization characteristic line of the test piece No. 2 of the present example mounted, it is confirmed that the anodic polarization current is reduced. It is considered that this is because the copper complex compound formed on the surface of the copper alloy acts as anodic resistance for anodic dissolution. From the above, it was confirmed that the sealing materials of these examples have an electrochemical effect as an anticorrosive material.

Further, Table 3 shows the results of observing the sealing material of the pipe 3 by disassembling the test piece immersed in artificial seawater for 2000 hours. As is clear from the table, the test pieces (No. 1 to No. 1) equipped with the sealing material of this example.
In 5), anticorrosion was achieved.

[0048]

[Table 3]

FIG. 5 is a view showing the influence of the sealing material on the surface potential of the copper gap. As is apparent from FIG. 5, the test piece No. 1 or No. 1 according to the present embodiment described above.
The sealing materials 21 and 22 equipped with No. 2 are the sealing materials 2 equipped with test pieces No. 6 to No. 8 which are conventional materials.
It can be seen that the potential is higher than 3, 24 and 25. Further, as described above, the sealing material 2 in which isophthalyl dihydrazide is simply added as an antioxidant to the rubber base material 2
It can be seen that 6 has almost no effect.

6 and 7 are sectional views showing an embodiment of the pipe joint of the present invention. The three flange joints 30 shown in FIG.
With an O-ring 31 and a sheet packing 32 as a rubber sealing material between them, and the bolt 3
3 and the nut 34 to tighten, as shown in FIG.
It is assembled.

Further, this pipe joint was connected to the model loop shown in FIG. 7, and artificial seawater (room temperature) shown in Table 2 was circulated for 90 days to carry out a corrosion test. The model loop shown in FIG. 7 uses the artificial seawater stored in the water storage tank 35 as
It is sent to the flange joint 30 by the pump 36 via the flow rate adjusting valve 37, and is circulated again in the water storage tank 35. Further, the temperature of the artificial seawater in the water storage tank 35 is adjusted by the heat exchanger 38.

The flange joint 30 in this embodiment is used.
Is a copper alloy composed of 90% Cu-10% Ni, and the rubber sealing material installed on the connection flange surface of the flange joint 30 is an ethylene propylene rubber group as shown in Table 1 above. 0.5 parts of isophthalyl dihydrazide was mixed with the material and kneaded to form a plate, while sodium chloride was dispersed on the surface and cured. After that, the rubber plate was washed with water, and sodium chloride adhering to the surface thereof was washed away, and benzotriazole was added to methyl alcohol in an amount of 0.
Benzotriazole was attached to the surface layer of a rubber plate by a method of pouring a solvent having a concentration of 5M dissolved therein.

Also in the results of this corrosion test, with chloroprene rubber, styrene butadiene rubber, etc., corrosion damage was found on the flange surface and its vicinity, however, on the flange surface equipped with the sealing material of this example. No corrosion damage was observed, and as a result, it was found that the same anticorrosion effect as in Table 3 was achieved.

Further, FIG. 8 shows an apparatus similar to that of FIG. 2, but in order to investigate the effect of the rubber sealing material on the surface potential and the impedance (corrosion resistance) of the clearance of the flange joint, A glass capillary tube 40 made of potassium chloride and agar connected to a silver chloride electrode was installed in the gap portion, and the potential impedance (corrosion resistance) of the inner surface of the gap was measured.
The impedance (corrosion resistance) of the inner surface of the gap is guided to the potentiostat 42 by using the platinum electrode 41, a constant potential is applied to the inner surface of the gap at an arbitrary frequency by the frequency converter 43, and the response is personalized by the GPIB44 code. Measurements were taken in the computer 45.

As shown in the vector diagram shown in FIG. 9, the impedance (corrosion resistance) of the inner surface of the crevice was measured using a silver chloride electrode, and the result is that of the flange joint using the rubber sealing material according to the present invention. The impedance (corrosion resistance) Rf1 was larger than the impedance (corrosion resistance) Rf2 due to chloroprene rubber, and the anticorrosion effect was also recognized in this respect.

[0056]

As described above, according to the sealing material of the present invention, when it is used for equipment parts or pipes made of copper or copper alloy, it is possible to prevent the corrosion and erosion of the sealing material. Become. Further, according to the pipe joint of the present invention, there is an excellent effect in preventing crevice corrosion of a joint having a minute gap structure such as a bending joint or a flange joint in a piping system or piping equipment made of copper or a copper alloy.

[Brief description of the drawings]

1A and 1B show an embodiment of a sealing material of the present invention, in which FIG. 1A is a top view and FIG. 1B is a sectional view.

FIG. 2 is a configuration diagram of a test device in which the sealing material of the present invention is assembled into a pipe-shaped corrosion test piece.

FIG. 3 is a diagram showing measurement results of immersion time and electrode potential in a gap of a test piece.

FIG. 4 is a diagram showing the relationship between the potential of the inner surface of the gap of the corrosion test piece and the corrosion current density.

FIG. 5 is a diagram showing the effect of a sealing material on the surface potential of copper.

FIG. 6 is a sectional view showing the assembly of an embodiment of the pipe joint of the present invention.

FIG. 7 is a cross-sectional view showing an experimental model loop of an embodiment of the pipe joint assembled in FIG.

FIG. 8 is a configuration diagram of a test device for performing electrochemical measurement of the inner surface of the clearance of the flange joint in the pipe joint of the present invention.

FIG. 9 is a vector diagram showing the effect of the rubber sealing material on the impedance of the inner surface of the gap.

[Explanation of symbols]

1 Rubber Sealing Material 2 Bolt Hole 3 Flow Path 10 Sealing Test Piece 11 Metal Corrosion Test Piece Ring 12 Lead Wire 13 Glass Capillary 14 Platinum Counter Electrode 15 Plastic Container 16 Rubber Cap 17 Bolt 21, 22, 23, 24, 25, 26 Sealing Material 30 Flange joint 31 O-ring 32 Sheet packing 33 Bolt 34 Nut 35 Water tank 36 Pump 37 Flow rate adjusting valve 38 Heat exchanger 40 Glass capillary tube 41 Platinum electrode 42 Potentiostat 43 Frequency converter 44 GPIB 45 Personal computer Rf1 Impedance of the inner surface of the crevice when a sealant is applied Rf2 Impedance of the inner surface of the crevice when chloroprene rubber is applied

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyoyuki Okamura 603, Kamidate-cho, Tsuchiura-shi, Ibaraki Hitate Factory Tsuchiura Plant

Claims (14)

[Claims] 1. A low organic heterocyclic compound consisting of benzotriazole, tritriazole, alkylylbenzotriazole or benzimidazole, either alone or in combination, in a rubbery substrate or on the surface of a rubbery substrate. A sealing material characterized by being added and attached. 2. The organic heterocyclic low compound is 0.005.
The sealing material according to claim 1, wherein 1 part to 0.10 part is added and adhered. 3. The rubber base material is a rubber obtained by blending ethylene propylene rubber with the diene compound, and
2. A phthalyl dihydrazide, an isophthalyl dihydrazide or a terephthalyl dihydrazide, each of which is used alone or in a combination of 0.1 part to 0.5 part. Or the sealing material described in 2. 4. A non-drying polymer substance containing non-drying oil, which is obtained by kneading by adding 70% to 95% of fine zinc powder,
Sealing characterized by adding 0.005 part to 0.10 part of an organic heterocyclic low compound consisting of benzotriazole, tritriazole, alkoxylbenzotriazole or benzimidazole, individually or in combination. Material. 5. The non-drying oil is castor oil, olive oil, or hydrocarbon oil.
Sealing material described. 6. The sealing material according to claim 4, wherein the non-drying oil has polyethylene glycol, auryl ether, or polyoxyethylene sorbita added as a stabilizer. 7. The non-drying polymer material containing the non-drying oil is polybutene, polyalkylethylene glycol,
7. The sealing material according to claim 4, 5 or 6, wherein a surfactant such as ethylene ester or zinc stearate, which is a simple substance or a complex of a derivative thereof, is used. 8. A sealing material comprising a rubber-based base material for corrosion prevention, which is used for a device member made of copper or copper alloy, wherein the rubber-based base material is benzotria in a base material or a surface layer of the base material. Characterized in that an organic heterocyclic low compound consisting of sol, tritriazole, alkylylbenzotriazole or benzimidazole is added individually or in a combination of 0.005 to 0.10 part. Sealing material. 9. A sealant comprising a rubber-based base material for corrosion prevention used in equipment or pipes made of copper or copper alloy, which is used in a seawater environment, wherein the rubber-based base material is ethylene propylene rubber and its diene A rubber compounded with phthalyl dihydrazide, isophthalyl dihydrazide or terephthalyl dihydrazide as an antioxidant, and 0.1 to 0.5 parts of them are compounded individually or in combination. However, an organic heterocyclic low compound consisting of benzotriazole, tritriazole, alkylylbenzotriazole or benzimidazole, individually or in combination, in the rubber base material or the surface layer thereof is used in an amount of 0.005 parts or more. A sealing material comprising 0.10 parts added and adhered. 10. A sealant for equipment and pipes mainly made of copper or copper alloy, which is a non-drying oil made of castor oil, olive oil or hydrocarbon oil, and polyethylene glycol, auryl ether or polyoxyethylene sol as a stabilizer. Vita was added, and zinc fine powder was added to 70
% To 95% by kneading and adding to the non-drying polymer substance, an organic heterocyclic low compound consisting of benzotriazole, tritriazole, alkylylbenzotriazole, or benzimidazole is used alone or in combination. 0.005 to 0.10 parts, and
A sealing material, wherein a surfactant such as ethylene ester or zinc stearate, which is a simple substance or a complex of polybutene, polyalkylethylene glycol or a derivative thereof, is used for the non-drying polymer substance. 11. A benzotriazole, tritriazole, alkoxylbenzotriazole or benzimidazole in a joint portion of a metal tube made of copper or a copper alloy, in a rubbery substrate or on a surface layer of a rubbery substrate. Organic heterocyclic low compounds are used individually or in combination of 0.0
A pipe joint equipped with a sealing material added at 05 parts to 0.10 parts. 12. The pipe joint according to claim 11, wherein the rubber base material is attached to a curved pipe joint portion of the metal pipe as a sealing material. 13. The pipe joint according to claim 11, wherein the rubber base material is attached to a flange joint of the metal pipe as a sealing material. 14. A non-drying high-molecular substance comprising castor oil, olive oil, or a hydrocarbon oil as a simple substance or a complex, and an organic heterocyclic ring low-molecular compound comprising benzotrifazole, tritriazole, alkylylbenzotriazole, or benzimidazole. A pipe joint, characterized in that a sealing material containing 0.005 to 0.10 part of the compound added individually or in combination is used for a flange joint of a metal pipe made of copper or a copper alloy.