JP2003183626A - Thread-link sealing material for joining pipe and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thread-like sealing material for joining pipes without causing drooping of liquid, exhibiting a high working property, having less shavings caused by an over-winding and less leak even on re-tightening and capable of easily improving a work-performing capability even if there is no sufficient work performing capability. <P>SOLUTION: This sealing material for joining the pipes is obtained by impregnating or coating a fluorine-based resin power to a thread-like base material consisting of a natural fiber by 30-98 wt.% content, and the method for producing the sealing material for joining the pipes is characterized by immersing the thread-like material consisting of the natural fiber into an aqueous medium suspended or dispersed with the fluorine-based resin powder, pulling up and drying to impregnate or coat the fluorine-based resin powder on the thread-like base material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread-like sealing material for pipe connection, which is free from liquid dripping, has little scraps due to overwinding, has little leakage even when re-tightened, and can be constructed with high workability. The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a general pipe connecting method using a metal pipe member and a joint member, a metal pipe member,
For example, zinc-plated steel pipe for water supply (SGPW), hard vinyl chloride lining steel pipe for water supply (SGP-VB), polyethylene powder lining steel pipe for water supply (SGP-PB), stainless steel pipe (SUS-304), copper and copper alloy joints Steel pipes for waterworks such as pipes, carbon steel pipes for pipes (SGP), stainless steel pipes (SUS-304), seamless pipes of copper and copper alloys, gas pipes such as carbon steel pipes for pressure pipes (SGP), steam pipes A pipe can be formed by combining various pipes such as oil pipes and their joint members, for example, sockets, elbows, cheeses, etc., and screw-joining them. When joining a metal pipe member and a joint member like this, in order to prevent leakage of gas or liquid, conventionally, a liquid sealing agent is applied to the screw portion of the metal pipe member, a tape-shaped sealing material, or the like. I wound it up and connected it.

[0003]

However, in the above liquid sealant, there are coating spots, liquid dripping, and long drying time when the metal pipe member is applied to the screw portion. Therefore, in order to improve the work performance, a high work construction capability that enables accurate and leak-free connection in a short time is required. Further, in the work of the tape-shaped sealing material, particularly when the winding work is continued without winding the winding start around the screw portion of the metal pipe member, the tape-shaped sealing material itself is not Rolling up occurs together, it moves together with the joint member so that it cannot fully function as a seal material, or the tape-shaped seal material is overwound. Excessive debris also caused dirt on the work site. Therefore, even in the case of the work of such a tape-shaped sealing material, since a high work construction capability is required, it cannot be easily done by anyone.

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventor has found that a thread-shaped sealing material for pipe connection, in which a thread-shaped base material is coated with a fluororesin, is used for a screw portion of a metal tube member. The present invention has been completed based on the finding that leakage can be sufficiently prevented only by winding along the screw groove. That is, the thread-shaped sealing material for a pipe of the present invention is a thread-shaped sealing material obtained by impregnating or coating a thread-shaped base material with a fluorine-based resin powder, and the content of the fluorine-based resin powder in the thread-shaped sealing material is 30 to 98% by weight. There is a feature. Further, the method for producing a thread-shaped sealing material for pipe connection, which is another invention of the present invention, comprises immersing a thread-shaped base material made of natural fibers in an aqueous medium in which a fluororesin powder is dispersed or suspended, The filamentous base material is pulled up and dried to impregnate or coat the thread-like base material with a fluorine-based resin powder.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION [I] Thread-shaped sealing material for pipe connection (1) Structure The thread-shaped sealing material for pipe connection of the present invention is obtained by impregnating or coating a fluorine-based resin powder into a thread-shaped substrate made of natural fiber. It is what was coated. (A) Filamentous base material As a fibrous base material made of natural fibers, not only holding the fluororesin powder layer, but also applying tensile force to the entire thread connecting material for pipe connection, or screwing the screw part of the metal tube member. It is important to have a thread-like shape in order to enter the groove. As such a filamentous substrate, a monofilament or a multifilament of natural fiber is usually used. However, a multifilament is easier to impregnate or coat with a fluororesin powder in a filamentous substrate composed of natural fibers. It is preferable because it is difficult to separate from the powder layer.

(B) Fluorine-based resin powder The fluorine-based resin powder impregnated in or coated on the filamentous base material made of natural fibers is impregnated into the filamentous base material made of natural fibers, or Is coated on. It is important that the coated fluororesin powder is a resin powder, and the fluororesin layer solidified by heating and melting and solidifying is too hard to be used as a thread-shaped sealing material.

(C) Content The proportion of the fluororesin powder contained in the thread-shaped sealing material is 30 to 98% by weight, preferably 75 to 95% by weight, particularly preferably 90 to 95% by weight, based on the total weight. %
Within the range of. If the ratio of the fluorine-based resin powder contained in the filamentous sealing material is less than the above range, sufficient sealing performance cannot be obtained, and the problem of galling between the metal pipe member and the joint member occurs. Further, if it exceeds the above range, protrusion from the screw groove occurs, which causes a problem that it becomes difficult to join with a scrap and a joint member.

(D) Thickness of thread-shaped sealing material The thickness of the thread-shaped sealing material obtained by impregnating or coating the fluorine-based resin powder in or on the thread-shaped substrate made of the above-mentioned natural fiber is as follows. Its diameter is generally 60
0 to 1,000 μm, preferably 700 to 900 μm,
Particularly preferably, it is about 750 to 850 μm. If the thickness of the filamentous sealing material is less than the above range, it tends to be difficult to contribute to the sealing property by being inserted into the bottom of the thread groove even if wound along the thread groove of the pipe. However, although it can be used by winding it in layers, it has a drawback that the work becomes complicated. Also,
If it exceeds the above range, the joint member tends to be difficult to join after being wound along the screw groove because it is too thick.

(2) Element material (A) Thread-like base material made of natural fiber (a) Examples of the thread-like base material made of natural fiber include monofilaments or multifilaments of natural fibers such as cotton, wool and hemp. be able to. Among the filamentous base materials made of these natural fibers, it is preferable to use cotton fibers. Also,
It is preferable to use these multifilaments.

(B) Properties Thread-like substrates made of these natural fibers are generally 100 to
A thickness of 1,000 denier, preferably 150 to 800 denier, particularly preferably 400 to 480 denier is used.

(B) Fluorine-based resin As the fluorine-based resin, tetrafluoroethylene resin, trifluorochloroethylene resin, perfluoroalkoxy resin, tetrafluoroethylene / ethylene copolymer resin, vinyl fluoride resin, fluorinated resin Examples thereof include vinylidene resin and dichlorodifluoroethylene resin. Among these fluororesins, it is preferable to use tetrafluoroethylene resin, trifluorochloroethylene resin, particularly tetrafluoroethylene resin. In particular, it is desirable to use a fluororesin powder having a particle size of 0.1 to 0.5 μm, preferably 0.15 to 0.35 μm.

(C) Other components In addition to the above components, components such as a dispersant, a dispersion aid and a binder can be used if necessary. Binder It is preferable to add a binder in addition to the above fluororesin. As the binder, specifically, for example, an adhesive such as latex or acrylic emulsion,
Alternatively, glycols, surfactants, oils and fats such as silicone oil, and the like can be given. The addition amount of the binder is generally 10% by weight or less, preferably 0.5 to 5% by weight, and particularly preferably 1 to 3% by weight.

(3) Usage The above-mentioned thread-like sealing material for pipe connection is used by cutting it into different lengths depending on the diameter of the metal pipe member used. Specifically, as the thread-shaped sealing material for pipe connection used for a metal pipe member having a diameter of 1 inch (inner diameter 25 mm), a thickness of 800 μm having a length of 300 mm,
As the thread-shaped sealing material for pipe connection used for a metal pipe member having a diameter of 2 inches (inner diameter 50 mm), a thickness of 800 μm is 900 mm in length, and a metal having a diameter of 3 inches (inner diameter 80 mm). As a thread-shaped sealing material for pipe connection used for pipe members, thickness 800 μm
It is usually used by cutting each of them into a length of 1500 mm.

[II] Method for producing thread-shaped sealing material for pipe connection As a method for producing the thread-shaped sealing material for pipe connection, various methods can be used. Basically, a fluororesin powder is dispersed. Or, in a suspended aqueous medium, after immersing the filamentous substrate made of natural fibers, then pulling up,
It is preferable to manufacture a thread-shaped sealing material for pipe connection by drying and impregnating or coating the thread-shaped base material made of natural fiber with a fluororesin.

(1) Dispersion or Suspension (A) Aqueous Medium As the aqueous medium for dispersing or suspending the fluororesin powder used in the method for producing the thread-shaped sealing material for pipe connection, water or lower alcohols is used. And water-containing lower alcohols. Among these, it is preferable to use water containing a dispersant. In addition to the above-mentioned dispersant, it is preferable to use a dispersion aid for imparting wettability to the fluororesin powder.

(A) Dispersant Examples of the above-mentioned dispersant include surfactants such as nonionic surfactants. The surfactant used here can exhibit the action and effect as a binder described later after drying. (b) Dispersion Aid As the above-mentioned dispersion aid, ethers such as ethyl ether, alcohols such as methyl alcohol, ethyl alcohol and the like can be mentioned.

(C) Binder It is preferable to mix a binder in the above aqueous medium, if necessary. Such binders are generally
The fluorine-based resin powder impregnated or coated on the filamentous base material made of natural fibers is softly attached and easily peels off or falls off.To prevent this, a binder is added to the fluorine-based resin powder to make it sticky. Is given. As a result, the impregnated or coated fluororesin powder is firmly attached to the thread-like base material made of natural fiber,
Since more filamentous resin powder can be coated on the filamentous substrate made of natural fiber, the above dipping,
The number of operations of pulling up and drying can be reduced.
Specific examples of such a binder include an adhesive such as latex and acrylic emulsion, or
Examples thereof include glycols, surfactants, and oils and fats such as silicone oil.

(B) Fluorine Resin Powder Examples of the fluorine resin powder include tetrafluoroethylene resin, trifluorochloroethylene resin, perfluoroalkoxy resin, tetrafluoroethylene / ethylene copolymer resin and the like. . Among these, it is particularly preferable to use a powder of tetrafluoroethylene resin.

(C) Dispersion or Suspension In order to disperse or suspend the fluororesin powder in the above aqueous medium, it is generally desirable to mix and disperse the above-mentioned dispersant and dispersion aid. In order to satisfactorily disperse or suspend the fluororesin powder in the aqueous medium, it is generally 30 to 5
Temperature of 0 ° C., generally pH 9-12, preferably 9-10
It is desirable to stir under the conditions of.

(2) Impregnation or Coating (A) Immersion By impregnating the filamentous substrate made of natural fibers in an aqueous medium in which the above-mentioned fluororesin powder is dispersed or suspended, Fluorine-based resin powder can be impregnated or coated between the filaments.

(B) Pull-up-Dry fluorocarbon resin powder dispersed or suspended in an aqueous medium impregnated or coated with a filamentous base material made of natural fibers is pulled up and quickly dried to obtain a filamentous base material made of natural fibers. The material can be impregnated or coated with a fluororesin powder. Drying is preferably performed under warm air generally heated to a temperature of room temperature to 100 ° C, preferably 40 to 60 ° C.

(C) Repeated Operation By repeating the above-mentioned operations of dipping, pulling up and drying, the thickness of the fluororesin powder layer impregnated or coated on the filamentous base material made of natural fiber can be increased. These operations are generally 2 to 80 times, preferably 2 to
The thread-like sealing material for pipe connection can be obtained by performing 20 times, particularly preferably 3 to 10 times.

[III] Applications (connection of pipes) The thread-shaped sealing material for pipe connection of the present invention obtained by the above-mentioned method is basically a thread-shaped base material made of natural fibers impregnated or coated with a fluororesin. After winding the thread-shaped sealing material for pipe connection along the screw groove of the screw portion of the metal pipe member, the metal pipe members can be connected to each other by screwing the joint member into the screw portion of the metal pipe member. .

(1) Metal Pipe Member (A) Screw Part As the screw groove part of the screw part of the metal pipe member used in the connection of the above pipe, a zinc-plated steel pipe for water supply (SGP)
W), hard vinyl chloride lining steel pipe for water supply (SGP-
VB), polyethylene powder lining steel pipe for water supply (SG
P-PB), stainless steel pipe (SUS-304), copper and copper alloy seamless pipe, etc., steel pipe for water supply, carbon steel pipe for piping (SGP), stainless steel pipe (SUS-304), copper and copper alloy seamless These are screw groove portions of screw portions formed at both ends of metal pipe members of various pipes such as pipes, gas pipes such as carbon steel pipes for pressure pipes (SGP), steam pipes, oil pipes. The depth of these screw groove portions is generally 1.479 mm in both cases of water pipes and gas pipes.

(2) Thread-shaped sealing material for pipe connection The thread-shaped sealing material for pipe connection, which is obtained by impregnating or coating a fluorine-based resin on a thread-shaped base material made of natural fiber wound along the screw groove of the above-mentioned screw part, is as described above. A thread-shaped sealing material for pipe connection as described above is used.

(3) Winding operation of thread-shaped sealing material The operation of winding the thread-shaped sealing material 3 for pipe connection around the screw groove portion 2 of the metal pipe member 1 is performed by screwing the screw portion 1a of the metal pipe member 1 as shown in FIG. The winding is started from the first groove portion 2a of the screw groove portion 2 which is considered to be effective in the screw groove portion 2. At this time, the thread-shaped sealing material 3 for connecting the pipe is screwed into the thread groove 2
It is indispensable for the thread-shaped sealing material 3 for connecting pipes to exert sufficient sealing performance to start winding in such a manner that it is pressed into the screw groove portion 2 with a fingertip or a nail tip so as not to cause a deviation due to winding. This is one of the major work processes. Thread-like sealing material 3 for pipe connection to thread groove 2
In the work process in which the winding work is performed along the spiral, the work is advanced while confirming whether the filamentous sealing material 3 for pipe connection does not float up from the screw groove portion 2, and the winding operation is completed. At the end of this winding operation, it is an essential work to exert the sealing performance that the thread-like sealing material 3 for pipe connection is pressed into the thread groove portion 2 just as at the start of winding. Further, if necessary, a liquid sealing material can be further applied.

(4) Joint member A joint which is threaded onto a thread-shaped sealing material for pipe connection 3 in which a fluorine-based resin 3 is coated on a thread-shaped base material made of a natural fiber wound along the screw groove portion 2 of the screw portion 1a. As the member 4, a joint member such as a socket, an elbow or cheese is used.

(5) Hand-tightening work The fitting of the joint member can be carried out in the same manner as the pipe connection using a normal liquid sealant. That is, it is important to perform sufficient tightening by hand tightening without using a tool such as a pipe wrench from the initial stage. This work is
It is also to prevent "biting".

(6) Mechanical tightening work When the tightening of the joint member 4 by the manual tightening work is completed, the tightening work is started by the pipe wrench. However, since the thread-shaped sealing material 3 for connecting pipes is formed by forming the fluorine-based resin layer 3b formed by coating the fluorine-based resin on the thread-shaped base material 3a made of natural fibers, the tightening of the joint member 4 is usually performed. Sufficiently tighten the screw portion 1a of the metal pipe member 1 and the screw portion 4a of the joint member 4 to which the liquid sealing agent is applied with a lower force (torque) than the tightening force (torque) due to the tightening work. You can Therefore,
When the work is performed by controlling the tightening force, there is a risk that the tightening will be excessive and the incomplete screw groove part may enter, so it is desirable to perform the tightening work under the control of the number of remaining screw groove parts 2. . At the connection between the metal pipe member 1 and the joint member 4 when the joint member 4 is tightened, the thread-like sealing material 3 for pipe connection, which is almost in the form of a thread, has entered the joint member 4, so shavings and the like Can hardly be seen.

(7) Formation of Pipe Line A pipe line can be formed and piped by screwing the screw portion of the metal pipe member and the screw portion of the joint member.
Further, the tightened screw portion can be re-tightened by a re-tightening operation if necessary.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following examples and comparative examples.

[I] Evaluation method (1) Sealing performance test of thread-shaped sealing material A zinc-plated steel pipe for water supply (SGP), which is the most used metal pipe member, is used, and it seems that the diameter is also the most used. A steel pipe member having a diameter of 2 inches (50 A) is cut into an appropriate length (150 to 200 mm), and screws are cut at both ends. After the taper screw cutting, the screw portion of the steel pipe member was completely washed off the cutting oil from the screw portion of the steel pipe member using a degreasing detergent or the like, and dried at room temperature. The thread-shaped sealing material was wound along the screw groove of the steel pipe member while the screw groove portion of the steel pipe member was completely degreased and dried. Then
As the joint member, a commercially available socket having the same diameter as the steel pipe member and a deformed socket are used as they are.
The steel pipe member and the joint member were combined and tightened, basic test pipes were assembled, and a leak test was performed. The contents of the leak test include a basic test that tests immediately after assembling and a test that performs testing after 24 hours (see Table 1), and a 45 degree angle back tightening of each connection after assembly, and 90 A tightening test (see Table 2) was carried out, and a seal performance test (see Table 3) was conducted when an open time was taken, in which a thread-shaped sealing material and a liquid sealing agent were used in combination. The sealing performance as a thread-shaped sealing material is judged by each test content, and it is tested whether it can be used as a sealing material. The test conditions are as shown below. Pressure Water pressure: 10MPa, 20MPa, 30MPa, 40MP
a, Air pressure: 10 MPa, 20 MPa, holding time Water pressure: 60 minutes Air pressure: 60 minutes

[II] Examples and Comparative Examples Example 1 (1) Preparation of mixed solvent of fluorine-based resin Tetrafluoroethylene resin powder having a particle size of 0.15 to 0.35 μm was added to a nonionic surfactant and acryl. A milky white fluororesin consisting of 60% by weight of tetrafluoroethylene resin powder, 35% by weight of water, 3.5% by weight of surfactant, and 1.5% by weight of binder by mixing and stirring an emulsion binder and water. A powder suspension was prepared.

(2) Manufacture of thread-shaped sealing material The above-mentioned milky white fluororesin powder suspension has a thickness of 480.
A denier (0.2 mm ± 0.1 mm) cotton thread is dipped to impregnate the cotton thread with a fluororesin powder suspension, then pulled up and dried under hot air at 50 ° C. Dipping and coating By repeating the work 5 times,
Fluorine-based resin powder was impregnated and coated at a ratio of 90% by weight to manufacture a thread-shaped sealing material for pipe connection having a diameter of 800 μm.

(3) Connection of pipes A zinc-plated steel pipe for water supply (SGP), which is the most commonly used metal pipe member, is used, and the diameter used is also considered to be 2 inches (50A). The steel pipe member is cut to an appropriate length of 150 to 200 mm, and screw grooves are cut at both ends. After the taper screw groove is cut, the thread portion of the steel pipe member is thoroughly rinsed with cutting oil using a degreasing detergent or the like, and dried at room temperature. Then, after the thread groove portion of the steel pipe member was completely degreased and dried, the thread sealing material for pipe connection described above was wound along the thread groove of the steel pipe member. Next, the socket having the same diameter and the odd-shaped socket used as the joint member were used as they were on the market. When the combination of both members with the joint member is ready, the steel pipe member and the joint member are combined and tightened to assemble the basic test pipe. Regarding the contents of the leak-proof test, a test to be performed immediately after assembly, a basic test to be performed after 24 hours, and a 45-degree angle re-tightening and a 90-degree angle re-tightening of each connection portion after assembly were performed. A tightening test and a sealing performance test in the case of taking an open time to perform a test using both a thread-shaped sealing material and a liquid sealing agent are performed. The sealing performance was measured to determine whether it could be used as a thread-shaped sealing material for pipe connection. The results are shown in Tables 1 to 3.

Comparative Example 1 A tape-shaped Teflon (registered trademark) sealing material having a thickness of 0.1 mm and a width of 13 mm was half-lapped (lapped with 6 to 7 mm) from the screw tip of the steel pipe member to form a screw thread of the steel pipe member. Was carried out in the same manner as in Example 1 except that the sample was wound in one direction for 4 to 5 weeks. The results are shown in Table 4. Example 1 was carried out in the same manner as in Example 1 except that the steel pipe member wound with the tape-shaped Teflon (registered trademark) sealing material was refastened to the angle shown in Table 4 by the above method. The results are shown in Table 5.

Comparative Example 2 A tape-shaped Teflon (registered trademark) sealing material having a thickness of 0.1 mm, a width of 13 mm, and a length of 900 mm, cut into 5 to 6 mm, and twisted into a thread shape was used as a screw groove portion of a steel pipe member. Example 1 was carried out in the same manner as in Example 1 except that the film was wound along it. The results are shown in Table 6.

Comparative Example 3 Example except that a tape-shaped Teflon (registered trademark) sealing material having a thickness of 0.1 mm, a width of 13 mm and a length of 900 mm, which was twisted into a thread shape, was wound along the screw groove portion of the steel pipe member. 1
It carried out similarly to. The results are shown in Table 7. Example 1 was carried out in the same manner as in Example 1 except that the steel pipe member having the tape-shaped Teflon (registered trademark) sealing material twisted into a thread shape and wound around the steel tube member was refastened to the angle shown in Table 8. The results are shown in Table 8.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

[Table 7]

[0046]

[Table 8]

[0047]

EFFECTS OF THE INVENTION The thread-like sealing material for pipe connection according to the present invention does not cause dripping even when used for connecting pipes, has high workability, has less scraps due to overwinding, and can be refastened. There is an advantage that there is little leakage and the work construction capacity can be easily improved even if the work construction capacity is not sufficient.

[Brief description of drawings]

FIG. 1 is a partially cutaway partial sectional view of a metal pipe member and a joint member in which a thread-shaped sealing material for pipe connection of the present invention is wound around a screw groove portion of a screw portion.

[Explanation of symbols]

1 Metal tube member 1a screw part 2 screw groove 2a first groove 3 Thread sealing material for pipe connection 4 joint members 4a screw part

Claims (7)

[Claims] 1. A thread-shaped sealing material obtained by impregnating or coating a fluorine-based resin powder on a thread-shaped substrate made of natural fibers, wherein the content of the fluorine-based resin powder in the thread-shaped sealing material is 30 to 98% by weight. Characteristic thread sealing material for pipe connection. 2. The thread-shaped sealing material for pipe connection according to claim 1, wherein the thread-shaped sealing material contains a binder in an amount of 10% by weight or less. 3. The thread sealing material has a diameter of 600 to 1.0.
The thread-shaped sealing material for pipe connection according to claim 1 or 2, which has a diameter of 00 μm. 4. A filamentous base material made of natural fibers is immersed in an aqueous medium in which a fluororesin powder is dispersed or suspended,
A method for producing a thread-shaped sealing material for pipe connection, which comprises pulling up and drying to impregnate or coat the thread-shaped base material with a fluorine-based resin powder. 5. The method for producing a thread-shaped sealing material for pipe connection according to claim 4, wherein the aqueous medium is water containing a fluororesin powder, a dispersant and a dispersion aid. 6. The method for producing a thread-shaped sealing material for pipe connection according to claim 4, wherein the binder is contained in the aqueous medium in an amount of 10% by weight or less. 7. The process of dipping, lifting and drying a filamentous substrate made of natural fibers is repeated 2 to 20 times.
7. The method for manufacturing the thread-shaped sealing material for pipe connection according to any one of 6 to 6.