WO2019013340A1

WO2019013340A1 - Anticorrosion structure and anticorrosion construction method, and member for anticorrosion structure

Info

Publication number: WO2019013340A1
Application number: PCT/JP2018/026580
Authority: WO
Inventors: 佐藤　昭良; 和弘棚木; 総一郎二坂; 宏之桜井; 貴男中村; 浩輔白方
Original assignee: 信越ポリマー株式会社
Priority date: 2017-07-14
Filing date: 2018-07-13
Publication date: 2019-01-17

Abstract

An anticorrosion structure provided with metal pipes and a self-adhesive silicone-based member or a self-fusing silicone-based member which is wound around a connection portion of the metal pipes.

Description

Corrosion-resistant structure, corrosion-resistant construction method, and corrosion-resistant structural member

The present invention relates to an anticorrosion structure and an anticorrosion method, and a member for the anticorrosion structure, for the purpose of preventing the corrosion of a connection portion of a pipe. Priority is claimed on Japanese Patent Application Nos. 2017-138287 and 2017-138288, filed July 14, 2017, the content of which is incorporated herein by reference.

Conventionally, in iron piping installed in railway facilities, factories, buildings, etc., a compound containing petrolatum or this compound is carried on a base material to prevent corrosion of the connection where the metal part is exposed. Anticorrosion tapes may be used. Petrolatum is a semi-solid mixture of a soft wax obtained by solvent dewaxing a lubricating oil fraction of petroleum and a heavy fraction of lubricating oil, which has excellent water repellency and suppresses water permeation. Excellent in effect. However, since the softening temperature is low, it melts in summer or under high temperature environment, and the phenomenon that the liquid component exudes to the surface (bleed out phenomenon) becomes a problem. Further, even at normal temperature, petrolatum is sticky and sticky, so soil is likely to be attached to the surface of the anticorrosion tape to be stained. As an invention for solving these problems, an anticorrosion tape containing a specific boiled oil and an inorganic filler is proposed instead of petrolatum (see Patent Document 1).

Japanese Patent No. 6027795

However, the anticorrosion tape of Patent Document 1 has the following problems. First, since it is not dry at the time of construction, it takes about 24 to 72 hours of drying time after construction in a state where contamination by soil dust is prevented, and a prolonged construction period becomes a problem. Moreover, although it contains the inorganic particle as a flame retardant, since it is a non-woven fabric impregnated with oil essentially, there is a concern in terms of fire resistance. Furthermore, it is said that it is preferable to add beforehand the component used as the polymeric compound hardened | cured after drying to the anti-corrosion tape of patent document 1. In this case, the deterioration of the anticorrosion tape with age is rapid, and the useful life of the anticorrosion tape is shorter than the life of the target metal to be installed, such as a steel pipe. If it does so, it will be necessary to remove the anticorrosion tape which deteriorated over time, and to perform maintenance inspections, such as a steel pipe etc., but it may be difficult to remove the hardened anticorrosion tape and to perform maintenance inspection.

The present invention provides a corrosion-resistant structure and a corrosion-resistant construction method using a silicone-based member that is easy to apply, and a member for corrosion-resistant structure.

[1] A corrosion resistant structure provided with a metal pipe and a self-adhesive or self-fusion type silicone-based member wound around a connection part of the metal pipe.
[2] A first silicone-based member wound around the connection portion, and a second silicone-based member wound on the first silicone-based member in an overlapping manner, are provided. The corrosion-resistant structure according to [1], wherein the silicone-based member is a self-adhesive silicone-based member and the second silicone-based member is a self-bonding silicone-based member.
[3] A first silicone-based member wound around the connection portion, and a second silicone-based member wound on the first silicone-based member in an overlapping manner, are provided. The corrosion-resistant structure according to [1], wherein the silicone-based member is a self-bonding silicone-based member, and the second silicone-based member is the self-adhesive silicone-based member.
[4] The first silicone-based member is a tape-like member, and the second silicone-based member is in the form of a tape or sheet wider than the first silicone-based member, and the second silicone is used. The corrosion resistant structure according to [2] or [3], wherein the base member is wound so as to cover the whole of the first silicone base member.
[5] A corrosion-resistant method in which a self-adhesive or self-bonding silicone-based member is wound around a metal pipe connection.
[6] The step of placing the self-adhesive type silicone-based member on a support film and exposing the adhesive surface of the silicone-based member to the surface, and bringing the adhesive surface into intimate contact with the first portion of the connection portion Of the first set of the first end portion and the second end portion of the first support film while the first end portion side of the first support film is wound toward one side as viewed from the first portion, While pulling the second end of the support film toward the other as viewed from the first portion while pulling the second end toward the back of the first portion. And pressing the self-adhesive type silicone-based member against the connection portion including the first portion, and winding the self-adhesive type silicone-based member in close contact with the connection portion, the method according to [5].
[7] A corrosion-resistant structural member wound around a connecting portion of a metal pipe, which is formed of a self-adhesive or self-bonding silicone-based member.
[8] A non-silicone sealing tape wound around the connection portion of the metal pipe, and the self-bonding type silicone system member wound and stacked on the sealing tape are provided. Corrosion resistant structure according to [1].
[9] The corrosion resistant structure according to [8], wherein the international rubber hardness (IRHD hardness) defined by JIS K 6253 of the self-bonding type silicone based member is 10 to 50.
[10] The corrosion-resistant structure according to [8], wherein a durometer hardness (A) defined by JIS K 6253 of the self-bonding type silicone-based member is 10 to 50.
[11] The preservative as set forth in any one of [8] to [10], wherein the self-bonding type silicone-based member is in the form of a tape and is spirally wound on the connection portion. Food structure.
[12] A corrosion-resistant method of spirally winding a tape-like self-bonding type silicone-based member at a connection portion of metal piping, which is based on JIS K 6253 of the self-bonding-type silicone based member The specified international rubber hardness (IRHD hardness) is 10 to 50, and the ratio (W2 / W1) of the width W1 before winding of the self-bonding type silicone based member to the width W2 after winding is 0. The corrosion-resistant construction method according to [5], which is wound so as to be 5 to 0.8.
[13] It is wound around a metal pipe connection portion formed of a self-bonding type silicone-based member having an international rubber hardness (IRHD hardness) specified by JIS K 6253 of 10 to 50, [ The member for corrosion-resistant structure as described in 7].
[14] The corrosion resistant structural member according to [7], wherein the silicone based member is transparent.

In the corrosion resistant structure of the present invention, since the silicone-based member is wound around the connection portion of the metal pipe, it prevents corrosion of water or oxygen causing the corrosion to the contact portion, thereby preventing corrosion, Excellent weather resistance and durability. In addition, it is advantageous in terms of fire resistance as compared to conventional anticorrosion tapes impregnated with oil. Furthermore, since it does not exhibit a sticky viscosity after construction, it is possible to prevent the contamination of the connection even in a dusty environment. Moreover, the silicone-based member after construction can be easily removed as needed.
In the corrosion-resistant construction method of the present invention, the construction can be completed by winding the silicone-based member not exhibiting the viscosity around the connection portion, so that the construction can be completed simply and in a short period of time without requiring a drying time.
In addition, since the silicone-based member after construction can be easily removed as necessary, maintenance and inspection of the connection portion of the pipe can be easily performed.
The corrosion resistant structural member of the present invention is useful in the above-described corrosion resistant construction and corrosion resistant construction method.

It is a side view which shows an example of the connection part of metal piping. It is a side view which shows an example which covered the single tape-like member in the shape of a spiral in the connection part of metal piping. It is a side view showing an example which piled up a plurality of tape-like members on the connection part of metal piping, and was covered spirally. It is a perspective view which shows an example of the construction method which winds a silicone type member around the connection part of metal piping installed in the groove | channel.

«Corrosion resistant structure (1)»
A first aspect of the present invention is a corrosion-resistant structure provided with a metal pipe and a self-adhesive silicone-based member wound around a connection part of the metal pipe.
Hereinafter, embodiments of the present invention will be illustrated with reference to the drawings.

<Metal piping>
As shown in FIG. 1, the threaded portion A of the metal pipe 10 is a portion where the groove 11 of the external thread is formed at the end of the first pipe 10, and is generally a portion where corrosion is likely to occur. The internal thread of the second pipe 20 may be superimposed on the external thread 11, and the threaded portion A in this case is called a pipe connection.
The connection portion of the metal pipe is not limited to threading but may be a portion connected by welding.
The shape in the longitudinal direction of the first pipe 10 and the second pipe 20 is not particularly limited, and may be linear or bent. Further, the length in the longitudinal direction is also not particularly limited, and may be, for example, about 30 cm to 1 m. The diameters of the first pipe 10 and the second pipe 20 are not particularly limited, and may be, for example, about 1 cm to 1 m. Tube walls other than the threaded portion A of the first pipe 10 and the second pipe 20 may be coated with a resin.

First Embodiment
As shown in FIG. 2, the corrosion-resistant structure of the first embodiment is provided with a self-adhesive silicone-based member 30 wound around a threaded portion A of a metal pipe 10.
The threaded portion (connection portion) A of the first pipe 10 and the second pipe 20 is made of metal, and in the state in which the self-adhesive type silicone-based member 30 is wound, the threaded portion A is formed by the silicone-based member 30. It is coated and protected from oxygen and moisture causing corrosion. On the other hand, in a state in which the silicone-based member 30 is removed (see FIG. 1), at least a part of the metal of the threaded portion (connection portion) A is exposed.

(Self-adhesive silicone type member)
The self-adhesive silicone-based member 30 used in the present embodiment is a member made of a curable silicone rubber which is in an uncured state before use and is cured after being wound around a connection portion.
The curable silicone rubber is generally classified into two types. One is a so-called addition-curable silicone rubber which is stored at a low temperature when not in use and is cured by heating to a temperature above normal temperature during curing. The other is a so-called condensation type silicone rubber which is stored in a dry environment (moisture-proof environment) when not in use and is cured by absorbing moisture in the air when it is cured. The self-adhesive silicone-based member 30 of this embodiment may be an addition curing type or a condensation curing type.
The curable silicone rubber can be molded into the desired shape and retain the shape after molding. The curable silicone rubber is non-flowable and has the property of being deformed by compression. The curable silicone rubber preferably has a Williams plasticity (25 ° C.) of 50 to 450, and particularly preferably 50 to 300. If the degree of deformation is within the above range, it can be molded into a desired shape in an uncured state, and it can be easily deformed when compressed although it can retain its shape. If the degree of William plasticity is above the lower limit value, it can be molded without flowability, and if it is below the above upper limit value, it can be easily deformed when compressed. The degree of Williams plasticity is measured according to JIS K 6249: 1997 "Test method of uncured and cured silicone rubber". That is, a parallel-plate plasticity meter ("Uriam Plus and Meter" manufactured by Ueshima Seisakusho Co., Ltd.) with a dial gauge by using a spherical test piece of 2 g of a curable silicone rubber under an environment of 25 ° C and sandwiching this test piece in cellophane paper The test piece is placed in the container and loaded for 3 minutes under a load of 5 kg, and then the dial gauge is read to a millimeter, the thickness of the test piece is recorded, and this value is multiplied by 100 to obtain the degree of freedom.

From the viewpoint of enhancing the adhesion of the self-adhesive silicone-based member 30 to the threaded portion A, the threaded portion A is preferably subjected to primer treatment in advance. The selection of the primer agent can be optionally selected from known primer agents depending on the type of curable silicone rubber constituting the silicone-based member 30 used.
The adhesive strength of the curable silicone rubber to the primer-treated SUS 304 is preferably 10 N / mm or more when evaluated based on, for example, the “90-degree peel test adhesive strength” of JIS K 6854-1: 1999. . The upper limit value is not particularly limited, but in consideration of removing the silicone-based member 30 from the threaded portion A for maintenance inspection, for example, about 100 N / mm may be mentioned as the upper limit.

From the viewpoint of enhancing the protection performance of the threaded portion A by the self-adhesive type silicone-based member 30, the hardness after curing of the curable silicone rubber constituting the silicone-based member 30 is referred to as "Part 3: JIS K 6253: 2012". When it evaluates based on durometer hardness (type A), it is preferable that it is A40 or more. Although the upper limit value is not particularly limited, in consideration of removing the silicone-based member 30 from the threaded portion A for maintenance and inspection, for example, about A90 may be mentioned as the upper limit.

As a suitable self-adhesive silicone-based member having the above-mentioned William's plasticity, adhesive strength and hardness, for example, HR-2388S (addition-curable type, room temperature curing, sold as “Polymer Ace” manufactured by Shin-Etsu Polymer Co., Ltd. HR-120S (addition curing type, heat curing), HR-120NP (addition curing type, heat curing), HJ-14S (condensation curing type), HJ-1588L (condensation curing type), and the like.

In the example of FIG. 2, a tape-like, self-adhesive silicone-based member 30 is spirally wound around the threaded portion A. The width and length of the tape are appropriately set in accordance with the length of the threaded portion A. For example, when the length along the longitudinal direction of the pipe (diameter 5 cm) of the threaded portion A is 15 cm, the width 2 mm of the tape The length of the tape may be about 100 cm to about 20 cm to 30 cm. The self-adhesive silicone-based member 30 cut into a wide sheet shape may be wound. The thickness of the self-adhesive silicone-based member 30 is preferably 0.3 to 10 mm, more preferably 1 to 2 mm.

The above self-adhesive silicone-based member is excellent in adhesion, durability, and handleability, and thus is extremely useful as a corrosion-resistant structural member wound around a connection portion of metal piping.

It is preferable that the above-mentioned self-adhesive type silicone system member is transparent. By being transparent, it is possible to see through the wound self-adhesive silicone-based member and observe the state of the connection inside the corrosion-resistant structure. Since the appearance of the connection can be observed without removing the corrosion resistant structure, the necessity of maintenance of the piping including the connection can be easily examined.

According to the corrosion-resistant structure of the present embodiment, since the self-adhesive silicone-based member 30 is directly wound around the threaded portion A of the

metal pipe

10, 20, the silicone-based member relative to the threaded portion A 30 adheres well. As a result, it is possible to prevent water or oxygen causing corrosion from coming into contact with the threaded portion A, so that the corrosion resistance, weather resistance and durability of the threaded portion A can be sufficiently obtained. In addition, since the self-adhesive type silicone-based member 30 after curing does not exhibit a sticky viscosity, it is possible to prevent the contamination of the threaded portion A even in a dusty environment. In addition, by cutting the wound silicone-based member 30 with a cutter or the like along the longitudinal direction of the threaded portion A, it can be easily removed after construction if necessary.

Second Embodiment
As shown in FIG. 3, in the corrosion resistant structure according to the second embodiment, the first silicone-based member 30 wound around the threaded portion A of the metal pipe and the first silicone-based member 30 are stacked. And the second silicone-based member 40 that is wound.
In the example of FIG. 3, the first silicone-based member 30 is completely covered by the second silicone-based member 40 and is not exposed to the outside.

The first silicone-based member 30 may be the self-adhesive silicone-based member described above, or may be the self-bonding silicone-based member described later.
The second silicone-based member 40 may be the self-adhesive silicone-based member described above, or may be a self-bonding silicone-based member described later.

As a specific combination, (a) a combination in which the first silicone-based member 30 is a self-adhesive silicone-based member and the second silicone-based member 40 is a self-fusion-type silicone-based member; (b) a first And the second silicone-based member 40 is a self-adhesive silicone-based member; and (c) the first silicone-based member 30 is a self-adhesive silicone-based member. And a combination in which the second silicone-based member 40 is also a self-adhesive silicone-based member.
Among them, (a) or (c) is preferable because the first silicone-based member 30 is excellent in adhesion to the metal threading portion A in the uncured state, and the second silicone-based member 40 is overlapped. (A) is more preferable because the first silicone-based member 30 is compressed and the adhesion of the entire corrosion-resistant structure to the metal threaded portion A is further excellent.

In the example of FIG. 3, the tape-shaped first silicone-based member 30 is spirally wound so as to cover the threaded portion A, and the tape-shaped second silicone-based member 40 is further formed thereon. It is spirally wound so as to cover one silicone-based member 30.

The relationship between the width of the first silicone-based member 30 and the width of the second silicone-based member 40 is not particularly limited. For example, both may be in the form of a tape having a width of about 1 cm to 3 cm, or any one May be wider than the other tape shape, for example, in the form of a tape or sheet having a width of 4 cm to 20 cm. Here, the length of the tape-like member is longer than the width of the tape-like member, and the length of the sheet-like member is the same as or longer than the width of the sheet-like member.

From the viewpoint of improving the corrosion resistance, durability, adhesion and the like of the corrosion resistant structure of the present embodiment, the first silicone-based member 30 is in the form of a tape, and is spirally wound at least around the threaded portion A. Is preferred. Further, the second silicone-based member 40 is in a sheet-like or tape-like shape wider than the tape-like shape of the first silicone-based member 30, and wound so as to cover the entire first silicone-based member 30. It is more preferable that

(Self-fusion type silicone based member)
The self-bonding type silicone-based member of this embodiment is preferably a member made of a self-bonding type silicone rubber. The self-bonding silicone rubber is used in a pre-cured state without requiring a curing treatment at the time of use. As a self-bonding silicone rubber, for example, a silicone composition containing a diorganopolysiloxane shown by the following average composition formula (I) and a boric acid compound, which is disclosed in JP-A-2016-114180 A cured product obtained by curing

R ¹ _n SiO _(4-n) (I)
[In Formula (I), R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents any number in the range of 1.98 to 2.02. ]

R ¹ in the formula (I) is a hydrocarbon group having 1 to 10, preferably 1 to 8 carbon atoms. As a hydrocarbon group, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group etc. are mentioned. As an alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group etc. are mentioned, for example. As a cycloalkyl group, a cyclohexyl group etc. are mentioned, for example. As an alkenyl group, a vinyl group, an allyl group, a butenyl group, a hexenyl group etc. are mentioned, for example. As an aryl group, a phenyl group, a tolyl group, etc. are mentioned, for example.
R ¹ may be a group in which part or all of the hydrogen atoms of the hydrocarbon group are substituted with a halogen atom, a cyano group or the like.
R ¹ is an alkenyl group in the case of promoting the curing with an organic peroxide such as hydroperoxide, dialkyl peroxide, peroxy ester, diacyl peroxide, peroxy dicarbonate, etc. when curing the silicone composition Or a group in which part or all of the hydrogen atoms of the alkenyl group are substituted with a halogen atom or a cyano group.
N in the formula (I) is preferably 1.98 to 2.02 from the viewpoint of sufficiently obtaining the self-bonding property.

The kinematic viscosity at 25 ° C. of the diorganopolysiloxane is preferably 100 to 100,000,000 cSt, and more preferably 100,000 to 10,000,000 cSt. It is preferable for the dynamic viscosity at 25 ° C. of the diorganopolysiloxane to be in the above-mentioned range because the mechanical properties after curing are excellent.

Examples of the boric acid compound include boric acids such as boric anhydride, pyroboric acid and orthoboric acid; derivatives of boric anhydride such as trimethyl borate, triethyl borate and trimethoxyboroxine, and the like. Further, as the boric acid compound, for example, a polyorganoborosiloxane obtained by condensing an organoalkoxysilane such as dimethyldimethoxysilane or dimethyldiethoxysilane with boric anhydride can also be used.
The boric acid compounds may be used alone or in combination of two or more.

The content of the boric acid compound in the self-bonding type silicone-based member is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the diorganopolysiloxane. Is more preferable, and 1 to 5 parts by mass is more preferable. If the content ratio of the boric acid compound is equal to or more than the lower limit value, sufficient self-bonding property can be secured, and if it is equal to or less than the upper limit value, a decrease in mechanical physical properties can be suppressed.

The tensile strength (unit: N) along the longitudinal direction of the tape-like or sheet-like self-bonding type silicone-based member is preferably larger than the maximum load of the self-adhesive-type silicone-based member after curing, for example, 70 N It is preferable that it is more than, It is more preferable that it is 80 N or more, It is more preferable that it is 100 N or more.
The tensile elongation along the longitudinal direction of the tape-like or sheet-like self-bonding type silicone-based member is preferably larger than the tensile elongation of the self-adhesive type silicone-based member after curing, for example, 300% or more Is preferably 400% or more, and more preferably 500% or more.
If the above tensile strength and tensile elongation rate are above the lower limit value, sufficiently high self-bonding property can be exhibited, and it is more preferable for a threaded portion of a pipe or a self-adhesive silicone-based member wound there It can be in close contact.
The above tensile strength and tensile elongation are values measured at 23 ° C. at a tensile speed of 500 mm / min along the longitudinal direction of the tape-like or sheet-like silicone-based member using a tensile tester.

The above self-bonding type silicone-based member is preferably transparent. By being transparent, it is possible to see through the wound self-bonding type silicone based member and observe the state of the connection inside the corrosion resistant structure. Since the appearance of the connection can be observed without removing the corrosion resistant structure, the necessity of maintenance of the piping including the connection can be easily examined.

<< Anti-corrosion method (1) >>
A second aspect of the present invention is an anti-corrosion method in which a self-adhesive silicone-based member is wound around a connection portion of metal piping. By this construction method, the corrosion resistant structure of the first aspect can be formed.

As a method of winding the self-adhesive silicone-based member around the threaded portion A of the metal pipe 10 of FIG. 1, for example, a tape-like or sheet-like self-adhesive silicone-based member is used. There is a method of spirally winding to the side.

As an example, a tape-like or sheet-like first silicone-based member 30 is spirally wound on the threaded portion A of the pipe 10 of FIG. 1 (the pipe connection portion A of the pipes 10 and 20). Is covered, it becomes the form shown in FIG. Then, the tape-like or sheet-like second silicone-based member 40 is superimposed on the first silicone-based member 30 covering the screw-off portion A and wound in a spiral, thereby covering the first silicone-based member 30. The form shown in FIG. Here, it is preferable that the longitudinal direction of each of the silicone-based members to be spirally wound be along the spiral circumferential direction.

The first silicone-based member 30 and the second silicone-based member 40 may be independently a self-adhesive silicone-based member or a self-fusion-type silicone-based member. Preferred combinations include (a) to (c) described above.

Curing of the self-adhesive silicone may be promoted by heating the self-adhesive silicone-based member after being wound around the threaded portion A. This is because the properties of the self-adhesive silicone-based member are sufficiently exhibited after curing. As a method of heating, for example, a method of blowing hot air with a dryer can be mentioned.
When winding the self-bonding type silicone-based member around the threaded portion A, it is preferable to wind the self-bonding-type silicone-based member while stretching it in the longitudinal direction, from the viewpoint of enhancing adhesion and self-bonding power.

The following method may also be mentioned as a method of winding a self-adhesive silicone-based member around the threaded portion A (see FIG. 4). First, the non-adhesive surface of the self-adhesive silicone-based member 60 is placed on the support film 50 so as to be in contact with it, and the intermediate 70 is obtained with the adhesive surface 60a opposite to the non-adhesive surface exposed on the surface. The adhesive surface 60a of the intermediate body 70 is brought into close contact with the first portion Aa of the threaded portion A (portion on the back side of the drawing of FIG. 4), and the support film 50 of the pair of

end portions

50a and 50b of the support film 50. While winding the first end 50a side toward one side as viewed from the first portion Aa of the threaded portion A (directed from the left to the right with respect to the pipe of FIG. 4), the first end 50a is first portion Pull to the back side of Aa (opposite direction), that is, the near side of the paper surface of FIG. At the same time, while winding the second end 50b side of the support film 50 toward the left as viewed from the first portion Aa of the threaded portion A (from the right to the left with respect to the pipe of FIG. 4), The second end 50b is pulled in the back direction (opposite direction) of the first portion Aa. The direction in which the first end 50a and the second end 50b are pulled is indicated by the arrow in FIG. As a result, the adhesive surface 60a of the self-adhesive silicone-based member 60 can be pressed against the threaded portion A including the first portion Aa, so that winding can be performed while sufficiently adhering closely.
According to the above-described method, even when the

pipes

10 and 20 are installed in narrow spaces (narrow spaces) where it is difficult for workers' hands such as in the groove and in the case to reach, self-adhesive silicone-based members 60 can be wound. After winding, the support film 50 is removed.

As the support film 50, for example, a relatively flexible resin film such as polyethylene, polyolefin, polyester, etc. is preferable. The size of the support film 50 is preferably larger than that of the self-adhesive silicone-based member 60 from the viewpoint of facilitating the winding operation.

«Corrosion resistant structure (2)»
According to a third aspect of the present invention, a metal pipe and a silicone-based member wound around a connection portion of the metal pipe are provided, and the silicone-based member is a self-fusion type silicone-based member. It is a corrosion resistant structure. The self-bonding type silicone-based member may be wound directly to the connection portion or may be wound indirectly via another member.

<Metal pipe> The metal pipe is as described above.

Third Embodiment
Hereinafter, although 3rd embodiment is described using the figure used by description of 1st embodiment, 1st embodiment and 3rd embodiment are mutually independent, and are distinguished.
As shown in FIG. 2, the corrosion resistant structure of the third embodiment is provided with a non-silicone sealing tape 30 spirally wound around the threaded portion A of the metal pipe 10. Furthermore, as shown in FIG. 3, a self-bonding type silicone-based member 40 wound on the sealing tape 30 is provided. In the example of FIG. 3, the sealing tape 30 is completely covered by the self-bonding type silicone-based member 40 and is not exposed to the outside.

The sealing tape 30 of FIG. 2 may be replaced by a self-bonding type silicone-based member. In this case, the self-bonding type silicone-based member is directly wound around the threaded portion A. Another self-bonding type silicone-based member may be further wound on the self-bonding-type silicone-based member.

The threaded portion (connection portion) A of the first pipe 10 and the second pipe 20 is made of metal. In a state in which the sealing tape 30 and the self-bonding type silicone-based member 40 are wound, the threaded portion A is covered with the sealing tape 30 and the self-bonding-type silicone-based member 40 to cause oxygen causing corrosion. And protected from moisture. On the other hand, when the sealing tape 30 and the self-bonding type silicone-based member 40 are removed (see FIG. 1), at least a part of the metal of the threaded portion (connection portion) A is exposed.

The relationship between the width of the sealing tape 30 and the width of the self-bonding type silicone-based member 40 is not particularly limited. For example, both may be in the form of a tape having a width of about 1 cm to 3 cm. It may be in the form of a tape or a sheet, for example, 4 cm to 20 cm in width, which is wider than that of the tape. Here, the length of the tape-like member is longer than the width of the tape-like member, and the length of the sheet-like member is the same as or longer than the width of the sheet-like member.

The width and length of the tape-shaped member are appropriately set in accordance with the length of the threaded portion A. For example, when the length along the longitudinal direction of the pipe (diameter 5 cm) of the threaded portion A is 15 cm, the tape-shaped member 1 cm to 3 cm in width and about 20 cm to 30 cm in length.

From the viewpoint of improving the corrosion resistance, durability, adhesion and the like of the corrosion resistant structure of the present embodiment, the sealing tape 30 is preferably wound in a spiral shape around the threaded portion A. In addition, the self-bonding type silicone-based member 40 is in the form of a sheet or tape that is wider than the tape-like shape of the sealing tape 30, and is wound so as to cover the entire sealing tape 30. preferable. In particular, when the sheet-like self-fusion type silicone-based member 40 having a width and a length capable of covering the entire threaded portion A is wound, the seal tape 30 is reinforced while reducing the thickness of the corrosion resistant structure. Corrosion resistance and durability can be improved.

According to the corrosion-resistant structure of the present embodiment, since the seal tape 30 is directly wound around the threaded portion A of the

metal pipe

10, 20, the seal tape 30 is sufficiently in intimate contact with the threaded portion A. doing. Furthermore, since the self-bonding type silicone-based member 40 excellent in water resistance, durability, and weather resistance is overlapped and wound, adhesion to the threaded portion A of the seal tape 30 is further enhanced, and the seal tape 30 is formed. As it can be protected from external weather, dust, sunlight, etc., corrosion resistance, weather resistance and durability of the threaded portion A can be sufficiently obtained.

The self-bonding type silicone-based member 40 is a self-bonding type, and since it is cured before being wound, it does not exhibit sticky viscosity. Furthermore, by cutting the wound self-bonding type silicone-based member 40 with a cutter or the like along the longitudinal direction of the threaded portion A, it can be easily removed after construction if necessary.

(sealing tape)
The sealing tape used in the present embodiment is a sealing tape made of a non-silicone material. Usually, polytetrafluoroethylene (PTFE) is contained as a main component of 50% by mass or more based on the total mass of the sealing tape. The sealing tape of the present embodiment is preferably a sealing tetrafluoride ethylene resin unbaked tape (green tape) defined in JIS K 6885: 2005.

(Self-fusion type silicone based member)
The description of the self-bonding type silicone-based member that can be used in this embodiment is basically the same as the description of the self-bonding type silicone-based member described in the first embodiment. The points that are specifically stated as the explanation of the self-bonding type silicone-based member of this embodiment will be described below.

The international rubber hardness (IRHD hardness) of the self-bonding type silicone-based member is preferably 10 to 50, more preferably 20 to 45, and still more preferably 30 to 40.
A mechanical strength will increase that it is more than the lower limit of the said range, and the adhesiveness with respect to a threading part will improve that it is less than the upper limit of the said range.

The above international rubber hardness (IRHD hardness) is defined by JIS K 6253 "Vulcanized rubber and thermoplastic rubber-Determination of hardness-Part 2: International rubber hardness (10 IRHD to 100 IRHD)" , M, values measured using a plunger having a tip ball diameter of φ 0.395 mm.

The durometer hardness (A) of the self-bonding type silicone-based member is preferably 10 to 50, more preferably 15 to 45, and still more preferably 20 to 30.
A mechanical strength will increase that it is more than the lower limit of the said range, and the adhesiveness with respect to a threading part will improve that it is less than the upper limit of the said range.

The above durometer hardness (A) is determined by using a type A tester according to the method specified in JIS K 6253 "Vulcanized rubber and thermoplastic rubber-Determination of hardness-Part 3: Durometer hardness". Measured value.

The tensile strength (unit: N) of the self-bonding type silicone-based member is preferably 100 N or less, more preferably 50 to 70 N.
When the tensile strength is 50 to 100 N or less, the self-bonding type silicone based member can be appropriately stretched without being broken when it is wound around the threaded portion, and the structure tends to be more closely attached to the threaded portion.

The tensile strength is determined by clamping a test piece (tape 25 mm wide and 1.0 mm thick) between a pair of chucks 30 mm apart from each other using Tensilon, and the tensile speed 500 mm / min, 20 It is the value measured along the longitudinal direction of the tape under the condition of ° C.
The above-mentioned Tensilon is a tester calibrated based on JIS B 7721 “Tensile tester / Compression tester-Calibration method and verification method of force measurement system”. Examples of the above-mentioned tensilon include a material testing machine manufactured by A & D Co., Ltd.

700% or more is preferable, as for the tensile elongation rate (unit:%) of a self-fusion-bonding type silicone type member, 750% or more is more preferable, and 800% or more is more preferable. The upper limit is not particularly limited, and may be, for example, about 1000% as a guide.
When the tensile elongation rate is 700% or more, since it is possible to wind around the screw in a stretched state while reducing the width while preventing tearing of the self-bonding type silicone based member when winding around the screw, It is easy to become a close structure.

The tensile elongation rate is determined by sandwiching a test piece (25 mm wide, 1.0 mm thick tape-like) with a pair of chucks separated by 30 mm each other using the above-mentioned Tensilon, and a tensile speed of 500 mm / min, It is a value measured along the longitudinal direction of the tape under the condition of 20 ° C.

The self-bonding type silicone-based member satisfying the above-mentioned physical properties, in particular the hardness, is excellent in adhesion, durability and handleability, and further, is excellent in durability at the time of submersion, so it is wound around a metal pipe connection It is very useful as a corrosion resistant structural member.

Self-fusion-type silicone-based member having the above hardness, tensile strength and tensile elongation by appropriately adjusting the kind and blending amount of diorganopolysiloxane and boric acid compound constituting the self-fusion-type silicone-based member Is obtained.

The self-bonding type silicone-based member as the corrosion-resistant structural member is preferably transparent. By being transparent, it is possible to see through the wound self-bonding type silicone based member and observe the state of the connection inside the corrosion resistant structure. Since the appearance of the connection can be observed without removing the corrosion resistant structure, the necessity of maintenance of the piping including the connection can be easily examined.

<< Anti-corrosion method (2) >>
A fourth aspect of the present invention is an anti-corrosion method in which a tape-like self-bonding type silicone-based member is spirally wound around a connection portion of a metal pipe. By this construction method, the corrosion resistant structure of the third aspect can be formed.
The international rubber hardness (IRHD hardness) defined by JIS K 6253 of the self-bonding type silicone-based member is preferably 10 to 50. Further, it is more preferable to satisfy the other physical properties described above.
The ratio (W2 / W1) of the width W1 before winding of the self-fusion bonding silicone member to the width W2 after winding is preferably 0.5 to 0.8. By winding so as to be 7, it becomes easier to form an excellent corrosion resistant structure.
When the ratio is 0.5 or more, it is possible to spirally wind the connecting portion while suppressing the breakage of the self-bonding type silicone-based member.
When the ratio is 0.8 or less, the stretchability and elasticity of the self-bonding type silicone-based member are easily utilized, and the self-bonding-type silicone-based member is spirally wound around the connecting portion while being stretched. By doing this, the adhesion can be further improved.

In this embodiment, the length (W2 / W1) of the above-mentioned ratio (W2 / W1) is 0.5 or less, where L1 is the length of the region in which the thread groove of the threaded portion is formed when viewed in the longitudinal direction Let L2 be the length of the area wound so as to be 0.8. At this time, the ratio of both lengths (L2 / L1) is preferably 2 to 6, and more preferably 3 to 5. That is, it is most preferable to wind the self-bonding type silicone-based member in a suitable range of the above ratio (W2 / W1) in a region longer than the total length of the threaded portion over the entire length of the threaded portion.

Example 1-1
First, a self-adhesive silicone rubber tape (Shin-Etsu Polymer, 20 mm wide, Williams plasticity 200) manufactured by Shin-Etsu Polymer Co., Ltd., as a first silicone-based member, is used for a metal-exposed threaded section of a polyethylene-coated steel pipe (φ 24.7 mm). It was helically wound to cover the thread as shown in FIG.
Subsequently, a self-bonding type silicone rubber tape (manufactured by Shin-Etsu Polymer Co., Ltd., width 25 mm) as a second silicone-based member is overlapped on the first silicone-based member and spirally wound, as shown in FIG. Was coated. Thus, a corrosion resistant structure was formed at the threaded portion of the steel pipe. Three similar specimens were made.
With respect to the above corrosion resistant structure, in a salt spray test in accordance with JIS Z 2371, 1000 hours after the start of the test, the presence or absence of a change in the corrosion resistant structure was visually confirmed.
As a result of the confirmation, there was no particular change except that a small amount of salt was deposited on the surface of the silicone-based member forming the corrosion resistant structure, and peeling did not occur in any of the three test bodies. Next, it was cut with a cutter to remove the corrosion resistant structure, and the metal thread was exposed to confirm visually. As a result, no rust was generated in any of the three test bodies.
From the above results, it is clear that the corrosion resistant structure of Example 1-1 is excellent in corrosion resistance, weather resistance and durability.

Embodiment 1-2
A corrosion resistant structure was formed in the same manner as in Example 1-1 except that the first silicone-based member and the second silicone-based member in Example 1-1 were replaced, and a salt spray test was performed. That is, the same procedure was performed as in Example 1-1 except that a self-bonding type silicone rubber tape was used as the first silicone-based member and a self-adhesive silicone rubber tape was used as the second silicone-based member.
As a result, a small amount of salt was deposited on the surface of the corrosion resistant structure. Next, it was cut with a cutter to remove the corrosion resistant structure, and the metal thread was exposed to confirm visually, but it was slightly rusted.
From the above results, it was found that the corrosion resistance structure of Example 1-2 was inferior to that of Example 1-1 in some cases, but the corrosion resistance, the weather resistance and the durability were generally good.

Embodiment 1-3
A self-adhesive silicone rubber tape (Shin-Etsu Polymer, 25 mm wide, with a degree of plasticity of 100) was spirally wound on the same threaded portion of the same polyethylene-coated steel pipe as in Example 1-1, and then the threaded portion as shown in FIG. Was coated. Thus, a corrosion resistant structure was formed at the threaded portion of the steel pipe. Three similar specimens were made.
A salt spray test was conducted on the above-described corrosion resistant structure in the same manner as in Example 1-1.
As a result, a small amount of salt was deposited on the surface of the silicone-based member forming the corrosion resistant structure. Next, it was cut with a cutter to remove the corrosion-resistant structure, and the metal thread was exposed to confirm visually, but a little rusting occurred.
From the above results, it was found that although the corrosion resistance structure of Example 1-3 was inferior to that of Example 1-1, the corrosion resistance, the weather resistance, and the durability were generally good.

Comparative Example 1
A salt spray test was conducted in the same manner as in Example 1-1 in a state in which the metal threaded portion was exposed without forming the corrosion resistant structure in the same threaded portion of the polyethylene-coated steel pipe as in Example 1-1. As a result, rust was generated on more parts than in Examples 1-2 and 1-3 of the metal threaded portion.

Example 2-1
First, a self-bonding silicone rubber tape (Shin-Etsu Polymer Co., Ltd., width 25 mm) is spirally wound on a metal-exposed threaded portion of a polyethylene-coated steel pipe (φ 24.7 mm) as shown in FIG. The thread was covered. At this time, winding was performed so that the ratio (W2 / W1) = 0.68. Thus, a corrosion resistant structure was formed at the threaded portion of the steel pipe. Three similar specimens were made.
The physical property values measured by the method described above for the self-bonding silicone rubber tape used here are as follows.
· Tensile strength = 54.8 N
・ Tension elongation rate = 780%
Hardness (IRHD) = 30
・ Durometer hardness (A) = 24
With respect to the above corrosion resistant structure, in a salt spray test in accordance with JIS Z 2371, 1000 hours after the start of the test, the presence or absence of a change in the corrosion resistant structure was visually confirmed.
As a result, a small amount of salt was deposited on the surface of the self-bonding type silicone-based member forming the corrosion resistant structure. Next, the corrosion-resistant structure was removed by cutting with a cutter, and the metal thread was exposed to confirm visually. As a result, no rust was generated in any of the three test bodies.
From the above results, the evaluation of the corrosion resistance, weather resistance and durability of the corrosion resistant structure of Example 2-1 was good.

Embodiment 2-2
First, a sealing tape (width 20 mm) conforming to the JIS standard is spirally wound on a threaded portion of a polyethylene-coated steel pipe (φ 24.7 mm) where metal is exposed, and the threaded portion is covered as shown in FIG. did. Subsequently, the same self-fusion type silicone rubber tape (Shin-Etsu Polymer Co., Ltd., width 25 mm) as a silicone-based member is overlapped on the seal tape and spirally wound to cover the threaded portion as shown in FIG. did. Thus, a corrosion resistant structure was formed at the threaded portion of the steel pipe. Three similar specimens were made.
With respect to the above corrosion resistant structure, in a salt spray test in accordance with JIS Z 2371, 1000 hours after the start of the test, the presence or absence of a change in the corrosion resistant structure was visually confirmed.
As a result, there was no particular change except that a small amount of salt was deposited on the surface of the self-bonding type silicone-based member forming the corrosion resistant structure, and peeling did not occur in any of the three test bodies. Next, it was cut with a cutter to remove the corrosion resistant structure, and the metal thread was exposed to confirm visually. As a result, no rust was generated in any of the three test bodies.
From the above results, the evaluation of the corrosion resistance, weatherability and durability of the corrosion resistant structure of Example 2-2 was good as in Example 2-1.

Example 2-3
A corrosion resistant structure was formed in the same manner as in Example 2-1 except that the self-bonding type silicone rubber tape was changed to the following, and a salt spray test was performed. As a result, the same good results as in Example 2-1 were obtained.
The physical property values measured by the method described above for the self-bonding silicone rubber tape used here are as follows.
· Tensile strength = 67.2 N
· Tensile elongation = 871%
Hardness (IRHD) = 40
・ Durometer hardness (A) = 26.6

Example 2-4
A corrosion resistant structure was formed in the same manner as in Example 2-2 except that the self-bonding type silicone rubber tape was changed to the one used in Example 2-3, and a salt spray test was conducted. As a result, the same good results as in Example 2-2 were obtained.

Example 2-5
A corrosion resistant structure was formed in the same manner as in Example 2-1 except that the self-bonding type silicone rubber tape was changed to the following, and a salt spray test was performed.
As a result, unlike in Example 2-1, partial loosening and peeling occurred in one of the three test bodies. When it cut off with a cutter and removed anticorrosion structure and exposed the metal thread part and it checked visually, in one of three test bodies, a little rust had arisen.
The physical property values measured by the above-mentioned method are as follows about the self-bonding silicone rubber tape (Shin-Etsu Polymer Co., Ltd. make, water leak management) used here.
・ Tensile strength = 138.3 N
· Tensile elongation = 733%
Hardness (IRHD) = 61
-Durometer hardness (A) = 61.8
From the above, it was found that the anti-corrosion structure of Example 2-5 has corrosion resistance, weatherability, and durability, but is inferior to Examples 2-1 to 2-4.

Comparative Example 2-1
A salt spray test was carried out in the same manner as in Example 2-1, in a state in which the anticorrosion structure was not formed in the same threaded portion of the polyethylene-coated steel pipe as in Example 2-1, and the thread portion was exposed.
As a result, in any of the three test bodies, rust occurred in a wide range of the metal threaded portion.

Comparative Example 2-2
The seal tape was spirally wound on the same threaded portion of the same polyethylene-coated steel pipe as in Example 2-1 to cover the threaded portion as shown in FIG. Subsequently, another sealing tape was spirally wound on the previously wound sealing tape to cover the threaded portion as shown in FIG. Three similar specimens were made.
A salt spray test was conducted on the above-mentioned test specimens in the same manner as in Example 2-1.
As a result, a small amount of salt was deposited on the surface of the test body, and peeling occurred in a part of the spirally wound sealing tape in three of the three test bodies. Next, the seal tape was removed by cutting with a cutter, and the metal thread portion was exposed and visually confirmed. In three of the three test specimens, rust was observed.
From the above, the structure in which the sealing tape of Comparative Example 2-2 was doubly wound was inferior in the corrosion resistance, the weather resistance and the durability to those of Examples 2-1 to 2-5.

The corrosion resistant structure of the present invention can prevent water and oxygen causing corrosion from coming into contact with the connection portion of the metal pipe.

10 Metal pipe having male thread 20 Metal pipe having female thread A Threaded portion 11 Groove 30 constituting threaded portion A First member wound on the threaded portion 40 Threaded portion overlapped on the second portion Member 50 support film 60 sheet-like self-adhesive silicone member 70 intermediate

Claims

A corrosion resistant structure comprising a metal pipe and a self-adhesive or self-fusion type silicone-based member which is wound around a connection portion of the metal pipe.
A first silicone-based member wound around the connection portion;
And a second silicone-based member wound on top of the first silicone-based member.
The first silicone-based member is the self-adhesive silicone-based member,
The corrosion resistant structure according to claim 1, wherein the second silicone-based member is a self-bonding silicone-based member.
A first silicone-based member wound around the connection portion;
And a second silicone-based member wound on top of the first silicone-based member.
The first silicone-based member is a self-bonding silicone-based member,
The corrosion resistant structure according to claim 1, wherein the second silicone-based member is the self-adhesive silicone-based member.
The first silicone-based member is a tape-like member,
The second silicone-based member is in the form of a tape or sheet wider than the first silicone-based member,
The corrosion resistant structure according to claim 2 or 3, wherein the second silicone-based member is wound so as to cover the entire first silicone-based member.
A corrosion-resistant method in which a self-adhesive or self-bonding silicone-based member is wound around a metal pipe connection.
Placing the self-adhesive silicone-based member on a support film, with the adhesive surface of the silicone-based member exposed to the surface;
The adhesive surface is brought into close contact with the first portion of the connection portion, and the first end portion side of the support film of the pair of first end portions and the second end portion of the support film is viewed from the first portion While winding the first end toward the back side of the first portion while winding toward one side, and winding the second end side of the support film toward the other when viewed from the first portion, Pressing the self-adhesive silicone-based member against the connecting portion including the first portion by pulling the two end portions to the back side of the first portion, and winding the self-adhesive silicone-based member in close contact with the connecting portion. The corrosion resistant construction method according to item 5.
A corrosion-resistant structural member which is formed of a self-adhesive or self-bonding silicone-based member and is wound around a connection portion of metal piping.
A non-silicone sealing tape wound around the connection portion of the metal pipe;
The corrosion resistant structure according to claim 1, further comprising: the self-bonding type silicone-based member wound in an overlapping manner on the sealing tape.
The corrosion resistant structure according to claim 8, wherein the international rubber hardness (IRHD hardness) defined by JIS K 6253 of the self-bonding type silicone based member is 10 to 50.
The corrosion resistant structure according to claim 8, wherein a durometer hardness (A) defined by JIS K 6253 of the self-bonding type silicone based member is 10 to 50.
The corrosion resistant structure according to any one of claims 8 to 10, wherein the self-bonding type silicone-based member is in the form of a tape and is spirally wound on the connection portion.
It is a corrosion-resistant construction method in which a tape-like self-bonding type silicone-based member is spirally wound on a connection portion of metal piping,
The international rubber hardness (IRHD hardness) defined by JIS K 6253 of the self-bonding type silicone-based member is 10 to 50,
The method according to claim 5, wherein the winding is performed such that a ratio (W2 / W1) of the width W1 before winding of the self-fusion bonding silicone member to the width W2 after winding is 0.5 to 0.8. Anti-corrosion method.
8. A metal pipe connection portion formed by a self-bonding type silicone-based member having an international rubber hardness (IRHD hardness) defined by JIS K 6253 of 10 to 50, wound around a metal pipe connection portion. The corrosion resistant structural member as described.
The corrosion resistant structural member according to claim 7, wherein the silicone based member is transparent.