JPH0255471B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to sealing leaks in pipes, conduits, closed vessels, tanks, and closed systems suitable for containing or transporting fluids. In particular, the invention is suitable for sealing leaks in buried pipes for the transportation of fuel gases and for sealing leaks in telephone line conduits containing nitrogen or other inert gases under pressure. It is something. American Gas Journal
Detection of Gas Leaks (Gas Journal), August 1959, pp. 16-28.
The paper, titled ``Repair, and Prevention of Gas Leaks'', shows that the loss of fuel gas through pipeline leaks poses a significant economic burden as well as a safety risk. Additionally, fuel gas leaks reduce the effective capacity of the gas distribution system. Furthermore, another disadvantage of this gas leakage is that it reduces the pressure level within the distribution main below the desired limit. U.S. Patent No. 3507725 to Hylak et al.
No. 1, 2006, discloses a method for repairing gas mains whose joints are filled with fibers using a liquid sealing material. This method involves introducing a liquid monomer, such as styrene monomer, into the gas mains and at a low point in the system where leaky joints exist.
The monomer is flowed to saturate the packing area with a sealant and then polymerized over a relatively long period of time, ie, from 6 weeks to 3 months. Styrene is used as a liquid and no specific catalyst is listed in this patent. U.S. Patent No. 3578479 for Packo
No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, 2003, 2006, discloses the use of a silicon hydride, boron hydride, or alkoxyborane sealing material in conjunction with an alkyl metal to seal leaks in containers and the like. However, the success of this process requires the use of metal alkyls, which are dangerous pyrophoric substances, as co-reactants. Furthermore, such alkyl metals have the drawback of poor shelf life and being easily contaminated. The seal created by this co-reaction is due to the inevitable stratification of the components in the mixture and the fact that the volatilization curves of the components are different and therefore the relative concentrations of each component are different at different temperatures. Therefore, it tends to be brittle and lack stickiness and homogeneity. Similarly, U.S. Pat. No. 3,608,000 to Anderson discloses that volatile compounds that chemically react to form solid products according to the reaction equation shown in column 2, lines 4-5 thereof, It is disclosed that a sealant, which is a mixture of an organosilane and an alkyl metal, is introduced into the container. These systems also require alkyl metal coreactants similar to those required in US Pat. No. 3,578,479 and suffer from similar disadvantages. U.S. Pat. No. 2,265,962 to Bent et al.
In general, reference is made to the use of silane to seal leaks by forming an insoluble shield or plug by reaction of the silane with water. Some of the silanes described there have a nitrogen group containing four compounds: Si(NH ₂ )(OC ₂ H ₅ ) ₃ ; Si(NH ₂ )
( _OCH3 ) ₃ ;Si( _NO2 )( _OC2H5 ) ₃ ; _{Si
( OC2H4NH2 )4 .} These compounds are either very unstable or have very poor volatility, making them impractical for use in gas phase seals. Similarly, Bent et al.
No. 2,259,875 also relates to a method for treating leaks in the walls of gas holes with silane compounds, but only the four compounds disclosed therein contain nitrogen; they are aminosilanes. isn't it. Ceyzeriat U.S. Patent No.
No. 3,580,939 discloses the use of aminosilanes as crosslinking agents for diorgano-polysiloxane compositions. These liquid compositions, which naturally harden in the presence of water, have been proposed for joining slabs and pipes. Anderson, U.S. Pat. No. 4,026,976, shows the use of volatile organic monomers that can be polymerized in the presence of a catalyst to seal leaks in pipes, but this process results in Undesirably, a catalyst must be used which complicates the process and increases cost. In addition to the Anderson patent mentioned above, numerous other prior patents demonstrate the use of volatile mixtures to seal pipes. These include Anderson Patent Nos. 3634560, 3711305, and Anderson Patent Nos.
3716384, Patsuko No. 3483735 and Anderson No. 3660984. Also of interest in this regard is US Pat. No. 3,709,712 to Rossman, which relates to the use of volatile organic amines. and U.S. Pat. No. 3,711,309 to Patsko, which relates to the use of volatile alcohols or glycol ethers. Of little interest are US Pat. Nos. 3,483,736 and 3,523,771 to Anderson, and US Pat. Although much work has been done in the field of gas-phase sealing, as mentioned above, most sealing of gas-containing pipes relies on traditional leak point detection and We are continuing to dig up the area and physically patch the leaked area to repair it. Although flame ionization is often used, dogs are still being trained to smell gas leaks. All of these methods are expensive and often do not accurately locate leaks. However, the gas can travel a considerable distance along the pipe from the point of leak to a point where it can be detected at the surface. Also, the digging method is not only expensive, but also impossible where gas lines run under large buildings. The importance of sealing problems occurs in other moth-containing conduits as well. Moisture is also not tolerated in both above and underground telephone line conduits.
However, moisture tends to seep into the dielectric material separating telephone wires, resulting in interference between adjacent wires. Because of this problem, telephone line conduits are managed by constantly supplying a dry gas, such as nitrogen, under pressure, which requires high maintenance costs. Gas leakage problems also occur in many other situations, such as in chemical process plants and air conditioning units. It is therefore an object of the invention to overcome the drawbacks of the prior art as mentioned above. Another object of the invention is to provide pipes, pipelines,
The present invention is an improvement in sealing leaks in conduits, pipes, and containers using gaseous aminosilanes or mixtures of gaseous aminosilanes. Another object of the invention is an improved method for sealing leaks in pipes, pipelines and vessels under pressure, which provides a better seal, is safer, more stable and non-spontaneous. An object of the present invention is to provide a sealing method using a substance that is resistant to water. A further aim is to create a pipe that is more flexible and less brittle and therefore does not break easily when the pipe is moved, e.g. ground movement, and the seal is more homogeneous. The object of the present invention is to provide an improved method for seals. It is a further object of the present invention to provide an improved method of sealing containers using volatile, volatile or gaseous sealing compounds that are shelf stable and not easily contaminated. Another object of the invention is that it does not require the presence of any gaseous pyrophoric metal compound or catalyst;
The object of the present invention is to provide a volatile, volatilized or gaseous sealing composition that can be used on its own. In accordance with the present invention, pipes, pipelines, pipe systems, conduits, closed containers, tanks, and closed systems of air conditioning units suitable for containing gaseous fluids, all of which are generally A novel process is provided for sealing leaks in (considered as). The process of the invention is particularly useful for sealing leaks in underground pipe systems for fuel gas transportation, in telephone lines containing nitrogen gas or other inert gases under pressure, and in air conditioning systems containing chlorofluorocarbons. units and other gas systems such as chemical plants and refrigeration units. The present invention not only eliminates gas leakage into the atmosphere, but also eliminates gas leakage into the surrounding soil or through the bonding packing material. Air and other surrounding materials involved in the sealing operation are
Appropriately, the surrounding environment is relevant here. The sealing method of the invention has particular, but not exclusive application in sealing leaks in pipe systems using joints of the type sealed with fibrous packing material. Fibrous filling joints are widely used in city gas distribution systems. In this distribution system, sections of cast iron pipe are connected with bell-and-spigot type joints padded with fiber packing, generally jute fibers. However, the method of the invention can also be applied to seal small hole-type leaks in the body of each section of pipe, such as those caused by corrosion. Seals made in this manner tend to resist corrosion beyond that induced by electrical effects because they exhibit electrically insulating properties. According to the invention, a sealant precursor is first introduced under pressure into the container, either in gaseous form or in volatile liquid form that evaporates inside the container, preferably at ambient temperature. When the sealant compound begins to escape from a leak present in the container, the sealant reacts with the external dirt or moisture surrounding the leak in the container and polymerizes, leaving a solid material at the location where the leak is to be sealed. Form. In embodiments disclosed in the parent application of US Patent Application No. 966,327, the sealant precursor is an aminosilane or a mixture of aminosilanes. However, it is understood that the essential properties of the present invention are maintained even if a significant portion of the aminosilane is replaced by other silanes, and dangerous pyrophoric materials are avoided in any case. Certain advantages, particularly economic advantages, are achieved by mixing aminosilanes with other low cost silanes such as alkoxysilanes. The present invention provides for the use of organic silane monomers, typically gaseous or volatile, within the container that can polymerize upon contact with surrounding materials such as moisture, dirt, or sand, or combinations thereof. It uses a novel principle of sealing leaks in vessels or pipelines or the like by introducing it in vapor form. Polymerization takes place by contacting the polymerization inducer at the leak, and the monomer forms a solid polymerization product that acts as a sealant. Where desirable, pipelines and vessels are
Before introducing the monomers, it is first flushed with an inert gas. The organic monomer vapor is preferably introduced in a mixture with a gaseous vehicle or carrier that is inert towards the monomer. Inert gaseous media or flash gases are, for example, nitrogen, helium, natural gas or, in the case of air conditioning units, chlorofluorocarbons. The concentration of monomer vapor used will depend on the type of monomer, the type of sealing problem present, the size and nature of the leak, the environmental conditions of the vessel or pipeline,
It depends, inter alia, on the degree of humidity and the pressure and temperature of the carrier gas in the container or the like. Generally, the monomer concentration will be on the order of about 100-50,000 ppm, desirably 200-25,000 ppm, preferably less than 10,000 ppm, and ideally less than 5,000 ppm, but this should be considered as an example. However, it should not be limited to this. Polymerization reactions occur in a relatively short time, typically a few hours. On the other hand, when the sealing operation is performed dynamically as described below and the monomer concentration in the system is maintained below the most preferred 1000 ppm, the process can be carried out for an extended period of time, e.g. 2 months. It is done beyond. Where gas pipelines are sealed in relatively high humidity environments, the monomer concentration must be sufficiently low to prevent sealing of the gas consumer's gas burner tips. The concentration of such gases should then be reduced to, for example, 100-500 ppm under these conditions. Thus, as shown in the polymerization system below in Example 1, in accordance with one embodiment of the practice of the present invention, the aminosilane is in vapor form or in a volatile liquid such that the vapor can reach the location where the leak is occurring. is introduced into the container in the form of In the case of underground pipelines or gas mains, leaks can occur at jute-filled joints or at corroded areas and escape into the surrounding soil. In such cases, a matrix of either jute or earth is utilized to absorb aminosilane vapors and provide a site for polymerization to occur. The monomer is introduced into the container under sufficient pressure so that its vapor escapes through the leak into the surrounding environment. Sealing can be either static or dynamic. In static sealing, the portion of the container (e.g. gas line) to be sealed is isolated from the rest of the container,
Such areas are then purged of their contents by displacement with a carrier gas under pressure (carrier gas containing aminosilane vapor).
The carrier gas is a gas inert to the aminosilane, for example natural or fuel gas where the container is in the gas line. Under suitable conditions, a pre-flushing or pre-humidification is first carried out. After the mixture of carrier gas and aminosilane has been supplied, the end of the container in which the mixture has been supplied is closed and the gas is allowed to escape through the leak hole. The container is then checked for airtightness. The above process of static sealing is repeated multiple times until the container is sufficiently sealed. Static sealing proceeds quickly and is preferred when the vessel is relatively small, for example when the pipeline is short. However, dynamic seals are commonly used.
sealing) is preferred. The method involves feeding aminosilane monomer continuously or intermittently into the container along with the usual ingredients carried in the container. The component is, for example, natural gas or fuel gas as carrier in the case of gas pipelines, or nitrogen as carrier in the case of telephone line conduits. Such supply may be carried out in a manner similar to the conventional method of mixing odorants into natural gas or fuel gas. For example, by wicking, spraying, atomizing,
Alternatively, the monomer may be simply pumped into a container in liquid form and volatilized by a flow of carrier gas. In such dynamic seals, a carrier gas containing aminosilane vapor leaks through a leak hole and continues to leak until the leak hole is sealed. In many cases, in both static and intermittent dynamic seals, polymerization occurs more effectively after the flow of aminosilane monomer at the leak has ceased. Therefore, if a dynamic seal is required, it is desirable to add the aminosilane intermittently or alternately with a moist carrier gas. Intermittent supply methods are also desirable from an economic standpoint. In either case, the aminosilane is fed continuously or for a period sufficient to form a polymer and form a solid seal at the leak. This point is usually indicated by the pressure within the container reaching a certain value. In small closed systems, such as automotive air conditioning units, the aminosilane monomers are incorporated into the actual fluid material, such as a chlorofluorocarbon. In such cases, the unit will self-seal as it spreads to the leak. When this system is used to seal a pipeline, such as a gas main distribution system utilizing jute-filled joints, consideration must be given to the mode of operation of the line. Some gas systems are used to transport dry natural gas, and in such cases, these jute packings are hardened, making it difficult for aminosilanes to be incorporated into the juutes. Similarly, similar problems arise when pipelines are buried under very dry conditions. Under these circumstances, in order to secure sufficient moisture in the soil surrounding the area where the leak is located, it is necessary to either provide the packing with the amount of moisture that can be absorbed, or to add enough water to the soil surrounding the leak to initiate polymerization. It is desirable to pre-treat the line by adding moisture or injecting moisture to the required level. Although soil often contains some moisture, under dry conditions it is desirable to introduce sufficient moisture into the system to ensure proper polymerization conditions. However, if there is sufficient silica adjacent to the leak hole, the moisture problem becomes less important. Injection of aminosilane must be repeated many times until a leak-free condition is reached. For example, when performing static sealing, the internal pressure becomes a stable value by sealing the leakage part. As mentioned above, the sealant aminosilane gas may be introduced intermittently, alternating with the supply of moistened carrier gas. When the carrier gas is a natural or fuel gas, the aminosilane can be introduced at the same time as the odorant in a similar manner. This system is particularly useful when it is desired to simultaneously treat an entire gas distribution system where leaks already exist and where there are several growing leaks. The key to this invention lies in the proper selection of the sealing compound. In this invention, such suitable materials are
It is an aminosilane that is volatile under water and polymerizes on contact with moisture or soil in the leak area. Aminosilanes generally hydrolyze rapidly and
It is desirable because it has good volatility, forms a strong polymeric seal, and is substantially non-corrosive. In particular, such sealant compounds must: (1) It is an aminosilane; (2) It has a sufficiently high vapor pressure and pressure inside the container at an ambient temperature of 30 to 190°C (approximately -1.1 to 88°C, and the sealant vapor concentration is at least 100 ppm when mixed with the carrier gas. , more preferably at least
(3) the compound is monomeric and can be polymerized in the vapor state in the presence of moisture or soil to form a solid silicone polymer, or polysiloxane; , preferably a co-sealant,
It can be used in place of a portion of aminosilane. For example, a co-sealant can replace up to 90 mole percent of the aminosilane. However, the co-sealant must also be a silane and not a dangerous pyrophoric material, and also meet requirements (2) and (3) above when used in conjunction with aminosilanes. must be understood. Additionally, it is desirable that the volatile aminosilane monomer as well as the co-sealant be environmentally acceptable. It is further desirable that such monomers be non-corrosive and stable enough to be stored with little difficulty. A compound of the following formula was found as a substance meeting the above conditions. Therefore, it is necessary to select an alkyl group with a relatively short chain length.
It should be noted that otherwise the aminosilane will not volatilize at ambient temperature. Here, R is hydrogen, halogen, or R'(R' is an alkyl group having 1 to 4 carbon atoms or vinyl), and R ₁ is halogen, R', -OR', -NHR', or -N
(R') ₂ , preferably R' or -OR', _R2 is halogen, R', -OR', -NHR' or -N
(R') ₂ , preferably -OR' or -N(R') ₂
and R ₃ is -NHR' or -N(R') ₂ , preferably -N(R') ₂ . Amino-substituted silanes obtained by the reaction of primary amines with chlorosilane monomers include, for example,
Included are those in which one or more of R ₁ to R ₃ is NHR'. For example, the following compounds. Bis(isopropylamino)methylsilane Bis-isopropylaminomethoxymethylsilane However, in general, aminosilanes obtained from primary amines are less stable than those obtained from secondary amines, making these monomers less practical. Undesirable. Also included are amino-substituted silane monomers in which a halogen is bonded to a silicon atom. Examples include dimethylaminomethylchlorosilane, dimethylaminodimethylchlorosilane, dimethylaminomethyldichlorosilane, dimethylaminomethyldifluorosilane, dimethylaminodimethylfluorosilane, and the like. However, they also have significant effects, not to mention their toxicity and negative impact on the environment.
This is particularly undesirable if the container to be sealed is metal because of the problem of corrosion. It is also possible to use mixtures of the above compounds and mixtures of the above halogen-containing compounds, as long as they have poor volatility but are volatile at the temperature and pressure used. Generally, it is desirable that the aminosilane or mixture thereof be volatile at 30°C (approximately -1.1°C). That is, in a gas atmosphere,
It is desirable to have such volatility that the amount is at least 100 ppm, more preferably 200 ppm. Among the general formulas of usable substances mentioned above, bis(dimethylamino)methylsilane of the following formula is most preferred.

[Formula] MW=132.3 BP=112-113°C Other useful aminosilanes and mixtures thereof are as follows.

【formula】

[Formula] A combination of bis(dimethylamino)dimethylsilane and tris-(dimethylamino)methylsilane, the latter being used in an amount ranging from 1 to 5% of the silane mixture, a mixture of the aminosilanes described above. , etc. Co-sealant monomers can be selected from a wide variety of alkoxysilanes. A mixture of approximately 30% by weight aminosilane, particularly preferably bis(dimethylamino)methylsilane, approximately 60% by weight vinyltrimethoxysilane and approximately 10% by weight tetramethoxysilane has been found to be particularly effective. Ta. Other possible mixtures include acetoxysilane with aminosilane. Although acetoxysilanes such as dimethyldiacetoxysilane (bP = 170°C) and methyltriacetoxysilane (bP = 210°C) are less volatile than aminosilanes, they are relatively diluted
It can be used in dynamic methods at a concentration of 1000 ppm. On the other hand, acetoxysilane is not suitable for use in environments where acetic acid cannot be tolerated since acetic acid will be formed upon hydrolysis of the silane. Another group of co-sealants used with aminosilanes are thioesters formed from mercaptans. These are, for example, dimethylbis(methylmercapto)silane or methyltris(methylmercapto)silane. however,
The co-sealants have a higher volatility than is desirable and have a strong unpleasant odor, although not so high as to preclude their use at low levels in dynamic processes, and are commercially available. They don't like it because they can't do it. The present invention will be further clarified with reference to Examples below, but the present invention is not limited in any way by these descriptions. Reference Example 1 Bis(dimethylamino)methylsilane was produced according to the following reaction formula. 1 mole of gaseous dimethylamine
The reaction was passed into 700 ml of kerosene containing MeHSiCl ₂ until completion. Amine hydrochloride precipitated out and was removed by filtration. The product was obtained by distillation under reduced pressure. Example 1 A 1/2 x 50 inch (1.27 x 12.7 cm) pipe,
Two 1/8" (3.2mm) holes, two 1/16" (1.6mm) holes, 8" (20.3cm) apart,
Two 1/32 inch (0.8 mm) holes were drilled. This was filled with moist sand (15.2% water content) to a thickness of 8 inches (20.3 cm) from top to bottom. The pipe was then moistened by passing nitrogen through the pipe for one hour. Next, nitrogen gas was bubbled into the container containing bis(dimethylamino)methylsilane, the product of Reference Example 1 [cylinder pressure ~
5 psi (approximately 0.35 Kg/cm ² )], the silane was volatilized and the nitrogen was then passed through the pipe. A total of 49.0 g of silane was used during the 3 hour sealing period. After stopping the flow of nitrogen carrying gaseous aminosilane, the system was left undisturbed for 88 hours. The pipe was found to have no leaks and to hold a pressure of 15 psi (1.055 Kg/cm ² ). I removed the sand and took out the pipe. Small spherical polymers were formed at each hole location. The seal polymer had the appearance of sandy lumps and there was clearly sand in the polymer. When the polymer covering one of the 1/16 inch (1.6 mm) holes was cut away with a knife, the polymer was found to be a strong, hard material. The partially cut seal was removed until it was almost the original hole. The system was then pressurized with nitrogen and checked for leaks by increasing the pressure by 10 psi (0.7 Kg/cm ² ) each time. 60psi (4.2Kg/
cm ² ), the system was leak-free, but at 70 psi
(4.9Kg/cm ² ), the partially cut off seal burst. Connect this hole to a hose clamp (hose clamp).
clamp) and gasket, and apply 100 psi to the system.
(7.03 Kg/cm ² ), but there was no leakage in the remaining five seals. An experiment similar to the above was performed using bis-(dimethylamino)
It was carried out using 95 parts by weight of methylsilane and 5 parts by weight of methyltrimethoxysilane. Example 2 1/2 x 50 inches (1.27 x 12.7) with six 1/16 inch (1.6 mm) holes spaced 8 inches (20.3 cm) apart.
cm) pipes and one of these holes was filled with wet mud (clay-based soil with water content ~20 cm).
%), two holes were filled with dry sand ((0.2% water content), two holes were filled with wet sand (~10% water content), and the remaining one was filled with a gasket and hose clamp. Nitrogen gas containing bis(dimethylamino)methylsilane was blown continuously for 12 hours at a rate of 1.5 (~0.3/min) using a flow meter, and a total of 205 g of silane was used. It was stopped and left as it was for 64 hours.In the early stages of the experiment, the nitrogen gas pressure regulator was not used due to large pipe leaks.
At the end of the experiment, it took 3 seconds for the pressure to drop from 5 psi (0.35 Kg/cm ² ) to 0, even though no pressure was created in the pipe even when set to 10 psi (0.7 Kg/cm ² ). It took. An experiment similar to the above was performed using bis-(dimethylamino)
It was carried out using 85 parts of methylsilane and 15 parts of _H3CSi ( _OCOCH3 ) ₃ . Example 3: Use the bell end of a 3-inch bell spigot pipe to effectively wrap around a straight section (not a flared section) of the pipe. I tried to see if I could seal it. The two sections of pipe were tightened with a pipe stopper and the opening in the joint was filled with dry (unoiled) Oakum soaked in water. No other sealing materials were used, such as lead, which is often used in joints. When nitrogen gas was passed through the pipe, a large amount of leakage was observed at the jute seal. Even with the nitrogen pressure regulator set to 10 psi (0.7 Kg/cm ² ), the pressure in the pipe did not increase at all. 8. Place the pipe in damp sand (containing 10-12% water).
It was buried to a depth of 1 inch (20.3 cm) and nitrogen gas containing bis(dimethylamino)methylsilane was flushed through it. The flow meter was adjusted to read 1.0 (0.25/sec) and the nitrogen and silane mixture was flowed for 54 hours. During this time 215g of silane was used. After stopping the flow of nitrogen gas, it was allowed to stand for 66 hours. The nitrogen and silane mixture was again flowed at 0.25/min. After 24 hours, the flow was stopped and nitrogen was passed through the water.
The pipe was treated under a pressure of 1 psi (0.07 Kg/cm ² ) for 20 hours. 0.25 nitrogen/silane mixture for a further 54 hours.
/min. In 78 hours during this last two step process, 306 g of bis(dimethylamino)methylsilane was consumed. The originally large leak in the pipe was observed to be reduced to a small through hole. That is, a slight pressure (~2 psi (0.14 Kg/cm ² )) was achieved in the pipe, and it took several seconds for the leak to stop. Sand was removed for inspection of the jute joint. A tough polymer is formed completely around the joint and leak tests show that
It was confirmed that a seal of 90% or more was achieved at 10 psi (0.7 Kg/cm ² ). An experiment similar to the above was performed using bis-(dimethylamino)
50 parts of methylsilane and dimethylbis-(methyl-
Mercapto) was repeated using 50 parts of silane. Although bis(dimethylamino)methylsilane is used in all of the above examples, it is clear that similar results can be obtained using other aminosilanes or mixtures within the scope of the present invention. In fact, suitable mixtures, such as mixtures of bis(dimethylamino)dimethylsilane and tris(dimethylamino)methylsilane, can also be cured by cohydrolysis, similar to how silicone rubber is vulcanized at room temperature. Gives union. Sand and soil in pipe leaks act as a weak reinforcing filler, increasing seal strength. The above tris compound is
Only 1-5% of the silane mixture, although with a higher boiling point, i.e., lower vapor pressure, than desired.
When using small amounts of , its partial pressure in the gas mixture gives it a volatility similar to that of bis(dimethylamino)dimethylsilane. Example 4 An underground gas pipe was dynamically sealed using a mixture of 30% by weight bis(dimethylamino)methylsilane, 60% by weight vinyltrimethoxysilane and 10% by weight tetramethoxysilane. Dynamic seals were performed for approximately two months using sealant levels ranging from 200 to 500 parts by weight of sealant composition per million parts of gas. As a result of this test, excellent effectiveness was achieved. Example 5 The following aminosilane sealant combination is suitable for natural gas distribution systems. Examples 6-20 The following aminosilane sealant combinations are suitable for use in the present invention. Each of the (a) components mentioned in the following examples is bis-(isopropylamino)methylsilane; dimethylaminochlorosilane; dimethylaminodimethylchlorosilane; bis-(dimethylamino)methylsilane; methylmethoxydimethylaminosilane as component (b). in combination with aminosilane monomers such as; methyldimethoxydimethylaminosilane; dimethylmethoxydimethylaminosilane or mixtures thereof;
used. (6) Methyltrimethoxysilane (7) Methyltriethoxysilane (8) Dimethyldipropoxysilane (9) Butyldimethoxysilane (10) Methylbutyldiethoxysilane (11) H ₃ CSi (OCOCH ₃ ) ₃ (12) H ₃ CSiH (OCOCH ₃ ) ₂ (13) H ₃ CH ₂ CSi (OCOCH ₃ ) ₂ (OCH ₃ ) (14) H ₃ CSi (OCOCH ₃ ) (OCH ₃ ) ₂ (15) Dimethylbis-(methyl-mercapto) Silane (16) Methyl-tris-(methyl-mercapto)
Silane (17) amyl-tris-(methyl-mercapto)
Silane (18) Propylbis-(methyl-mercapto)silane (19) Dibutylbis-(ethyl-mercapto)silane (20) Methylmethoxybis-(ethyl-mercapto)silane Example 21 Methylmethoxydimethylaminosilane is prepared as follows. Prepared: In a 100 gallon glass lined kettle, add n-pentane solvent.
40 gallons (approximately 151) of methyldichlorosilane
I put 173 pounds (about 78.5Kg) (1.5 pounds mole) into it. It took over two hours to make a total of 48 pounds (approx.
21.8 Kg) (1.5 lb-mol) of anhydrous methyl alcohol was added to the kettle. The reaction mixture was heated to reflux to complete the esterification step and to remove hydrogen chloride. At this point, the reaction mixture is allowed to cool to low room temperature and 140 pounds (3.1 pound moles) of dimethylamine are added to the pentane solution of the partial ester, with cooling maintained during the addition. It was done. The reaction mixture was filtered to remove dimethylamine-HCl. A solution of the crude product in pentane was distilled to remove pentane and free dimethylamine. The crude product was distilled to obtain a fraction consisting primarily of the desired product. Methyldimethoxysilane: Bis(dimethylamino)methylsilane: In such a reaction, the compounds methyldimethoxydimethylaminosilane and methylmethoxybis(dimethylamino)silane are
It was formed in varying amounts as a by-product. However, since all of these compounds can be used in the aminosilane sealant compositions of the present invention, it should be understood that the crude product is used as is. Methyldimethoxydimethylaminosilane and dimethylmexydimethylaminosilane were prepared in a similar manner. The present invention achieves many benefits through the use of the previously mentioned materials. For example, the final product is better, softer, and even more homogeneous. The starting materials are safer, more stable and non-pyrophoric. No catalysts or gaseous organometallic compounds are required. Easily volatile compounds that react with water or sand under normal use conditions to form leak sealing polymers are utilized to form the self-sealing polysiloxane. The foregoing description of specific embodiments has sufficiently revealed the general nature of the invention that a third party, by applying his or her ordinary knowledge, may be able to ascertain the general nature of the invention. Such specific implementations may be easily modified and/or adapted to various applications without departing from the concept. It is therefore intended and intended that such adaptations and modifications be encompassed within the meaning and range of equivalents of the disclosed embodiments. It should be understood that the terminology or terminology used herein is for descriptive purposes only and is not intended to be limiting in any way.

Claims (1)

[Scope of Claims] 1. A method for forming a seal at a leakage site by polymerizing an organic monomer at the leakage site in a container, the method comprising: (a) an alkoxysilane monomer, an acetoxysilane monomer; and up to 90 mol% of at least one of mercaptosilane monomers;
(b) readily volatile at the ambient temperature of the container; [Here, R is H, halogen or R' (wherein R' is alkyl or vinyl having 1 to 4 carbon atoms), and R ₁ is halogen, R', -OR', -NHR' or - N
(R′) ₂ , where R ₂ is halogen, R′, −OR′, −NHR′ or −N
(R') ₂ and R ₃ is -NHR' or -N(R') ₂ ], and no alkyl metal or catalyst is present.
introducing a sealant composition into said container, said sealant composition being introduced under sufficient pressure for a sufficient period of time to contact said leakage portion with said monomers in a vapor state; A method characterized in that the leakage portion is sealed by polymerizing the monomer. 2. The method of claim 1, further comprising flushing the container with a humid gas inert to the sealant composition in a preliminary step. 3. The method of claim 1, wherein the container is a pipe buried in sand. 4. The method according to claim 1, wherein the container is a pipe buried in moist soil. 5 The aminosilane is bis(dimethylamino)
The method according to claim 1, wherein the methylsilane is methylsilane. 6 The aminosilane is bis(dimethylamino)
2. The method of claim 1, wherein the silane is selected from the group consisting of dimethylsilane, methoxydimethylaminomethylsilane, methoxybis(dimethylamino)methylsilane, dimethoxydimethylaminomethylsilane, and methoxydimethylaminodimethylsilane. 7. The method of claim 1, wherein the composition comprises about 30% by weight bis(dimethylamino)methylsilane, about 60% by weight vinyltrimethoxysilane and about 10% by weight tetramethoxysilane. 8. The method of claim 1, wherein the silane is conveyed in a gas inert thereto. 9 The sealant composition has a monomer vapor concentration of
9. A method as claimed in claim 8, in which a proportion ranging from 100 to 1000 ppm is introduced into the container in a continuous manner. 10. The method according to claim 1, which is carried out at a temperature of 1030 to 190 °C (-1.1°C to 88°C). 11 R ₁ is R' or -OR'; and R ₂ is -
OR' or -N(R') ₂
The method described in section. 12. Claim 1, wherein the container is a natural or fuel gas pipe and the aminosilane is introduced in an intermittent manner into the natural or fuel gas continuously conveyed in the gas pipe. the method of. 13. The method according to claim 1, wherein vinyltrimethoxysilane and tetramethoxysilane are used as the component a.