A method for treating the inner wall of a sampling steel cylinder, a silanization treatment agent and a sampling steel cylinder

Abstract

The present invention relates to the field of metal treatment, and specifically to a method for treating the inner wall of a sampling steel cylinder, a silanization treatment agent and a sampling steel cylinder. The present invention provides a silanization treatment agent for the inner wall of a sampling steel cylinder, comprising: 2wt% to 10wt% of a silane coupling agent; 10wt% to 20wt% of a modifier; 10wt% to 20wt% of an alcohol solvent; and the balance is water. The silanization treatment agent provided by the present invention can form a composite film layer on the inner surface of the sampling steel cylinder, effectively avoiding the adsorption of active impurities by the inner wall of the steel cylinder, while the inner wall is passivated firmly, so that the long-term use of the steel cylinder can be achieved. Experiments show that the impurity gas content of the sampling steel cylinder treated with the above-mentioned silanization treatment agent at different storage times is analyzed and detected. After the gas is stored in the sampling steel cylinder for 72 hours, the content of various impurity gases such as hydrogen sulfide, ethylene, formic acid, methanol and hydrogen chloride is basically unchanged.

Description

Technical Field

[0001] The invention relates to the field of metal treatment, in particular to a method for treating the inner wall of a sampling steel cylinder, a silanization treatment agent and a sampling steel cylinder. Background Art

[0002] The material of the sampling cylinder is generally stainless steel. For the sample gases such as refinery gas and hydrogen in the petrochemical industry, which contain impurities such as sulfides, unsaturated hydrocarbons, organic acids, aldehydes, halides, etc., when the impurity content is only at the ppm or even ppb level, the impurities in the sample gas to be analyzed can easily react chemically with the inner wall of the sampling cylinder or be adsorbed on the inner wall of the cylinder, thereby affecting the gas detection and analysis results, especially causing a large detection deviation in the factory analysis of some product gases. At present, the conventional method to reduce the influence of the cylinder on the impurity content of the gas is to treat the inner wall of the cylinder with polytetrafluoroethylene, thereby reducing the influence of the cylinder material on the impurity content of the gas. Although the effect of the inner wall of the cylinder treated with polytetrafluoroethylene is obvious and the analysis accuracy is effectively improved, the internal coating of polytetrafluoroethylene has certain restrictions on the ambient temperature and number of uses of the sampling cylinder. Too high or too low temperature can easily cause the polytetrafluoroethylene coating to deform or fall off. Too many sampling times can easily cause the polytetrafluoroethylene coating to become thinner or fall off after multiple filling and discharging flushing, resulting in the stainless steel inner wall of the sampling cylinder affecting the impurity content in the sample gas. Summary of the invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a method for treating the inner wall of a sampling cylinder, a silanization treatment agent and a sampling cylinder. The silanization treatment agent provided by the present invention can form a composite film layer on the inner surface of the sampling cylinder, effectively preventing the adsorption of active impurities by the inner wall of the sampling cylinder. At the same time, the inner wall is passivated firmly, so that the long-term use of the sampling cylinder can be achieved.

[0004] The present invention provides a silanization treatment agent for the inner wall of a sampling steel cylinder, comprising:

[0005] 2wt% to 10wt% of a silane coupling agent;

[0006] 10 wt% to 20 wt% of a modifier;

[0007] 10 wt% to 20 wt% of an alcohol solvent;

[0008] The balance is water.

[0009] Specifically, the silane coupling agent of the present invention is selected from one or more of vinyl triethoxysilane, β-aminoethyl γ-aminopropyl trimethoxysilane, epoxy silane, aminosilane, mercaptosilane, and chlorosilane, preferably vinyl triethoxysilane and β-aminoethyl γ-aminopropyl trimethoxysilane. In one embodiment, the silane coupling agent is selected from vinyl triethoxysilane and β-aminoethyl γ-aminopropyl trimethoxysilane in a mass ratio of 1:3. In one embodiment, the silane coupling agent is selected from vinyl triethoxysilane and β-aminoethyl γ-aminopropyl trimethoxysilane in a mass ratio of 2:8.

[0010] The modifier of the present invention is selected from one or more of malonic acid, succinic acid, pyruvic acid, and glycine. In one embodiment, the modifier is selected from malonic acid and glycine in a mass ratio of 1:1. The alcohol solvent of the present invention is selected from one or more of methanol or ethanol, preferably methanol.

[0011] In one embodiment of the present invention, the silanization agent comprises: 2wt% of silane coupling agent; 10wt% of modifier; 10wt% of alcohol solvent; the balance is water. In another embodiment of the present invention, the silanization agent comprises: 10wt% of silane coupling agent; 20wt% of modifier; 20wt% of alcohol solvent; the balance is water.

[0012] In one embodiment, the silanization agent comprises: 0.5 wt% of vinyl triethoxysilane; 1.5 wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; 5 wt% of malonic acid; 5 wt% of glycine; 10 wt% of methanol; the balance is water. In another embodiment, the silanization agent comprises: 2 wt% of vinyl triethoxysilane; 8 wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; 10 wt% of malonic acid; 10 wt% of glycine; 20 wt% of methanol; the balance is water.

[0013] The silanization agent provided by the present invention does not contain harmful heavy metals such as chromium, nickel, and copper. The silanization agent is used to perform silanization treatment on the inner surface of the sampling steel cylinder, which can form a composite film layer on the inner surface of the sampling steel cylinder, effectively avoiding the adsorption of active impurities on the inner wall of the sampling steel cylinder, and at the same time, the inner wall is passivated firmly, so that the long-term use of the sampling steel cylinder can be achieved; at the same time, the chemicals used in the silanization treatment process of the sampling steel cylinder using the silanization agent do not contain phosphorus, sulfur and other environmentally unfriendly elements.

[0014] The present invention provides a method for processing the inner wall of a sampling cylinder, comprising the following steps:

[0015] The sampling steel cylinder is immersed in a silanization agent and cured, and the obtained sampling steel cylinder is annealed to form a composite film layer on the inner wall surface of the steel cylinder; the silanization agent is the above-mentioned silanization agent.

[0016] The present invention first soaks the sampling steel cylinder in the above-mentioned silanization treatment agent and performs a curing treatment. Specifically, the present invention first soaks the sampling steel cylinder in the above-mentioned silanization treatment agent and then performs a curing treatment. In one embodiment, the soaking time is 5min to 10min; the soaking temperature is 20°C to 40°C. In one embodiment, the curing treatment temperature is 80°C to 120°C; the curing treatment time is 1h to 3h. The present invention soaks the sampling steel cylinder in the silanization treatment agent to perform a silanization treatment on the inner wall surface of the sampling steel cylinder. The SiOH group in the silane coupling agent condenses with the MeOH group on the metal surface to form a firm film structure, and then performs a curing treatment to form a silanized film layer on the inner surface of the sampling steel cylinder. The formed silanized film layer has a certain passivation performance and can be used for sampling and storage of gases with impurity content at the ppm level.

[0017] The present invention immerses the sampling steel cylinder in the above-mentioned silanization treatment agent and performs a curing treatment, and then anneals the sampling steel cylinder obtained after the immersion and curing treatment to form a composite film layer on the inner wall surface of the steel cylinder. Specifically, the present invention anneals the sampling steel cylinder obtained after the immersion and curing treatment in a protective gas atmosphere, so that the above-mentioned silanization film layer is further decarburized and dehydrogenated, and a silicon nitride layer is formed on the surface of the above-mentioned silanization film layer, and finally a silane-silicon nitride composite film layer is formed on the inner wall surface of the steel cylinder. In one embodiment, the protective gas is selected from at least one of nitrogen, helium or argon, preferably nitrogen. In one embodiment, the temperature of the annealing treatment is 500°C to 800°C; the time of the annealing treatment is 1h to 2h. The present invention performs annealing treatment on the sampling steel cylinder obtained after the immersion and curing treatment, and the silanized film layer on the inner wall of the steel cylinder is further decarburized and dehydrogenated, thereby increasing the density, corrosion resistance, high temperature resistance and wear resistance of the silanized film layer, while maintaining the same passivation performance as the traditional polytetrafluoroethylene coating, increasing the service life of the sampling steel cylinder, and being suitable for frequent filling and deflation of the sampling steel cylinder.

[0018] The present invention further includes degreasing and derusting the sampling cylinder before the immersion and curing treatment. Specifically, the present invention sequentially degreases and derusts the sampling cylinder. In certain embodiments of the present invention, a non-phosphorus alkaline cleaning agent is first used to ultrasonically degrease the inner wall surface of the sampling cylinder to remove residual lipid pollutants on the inner wall surface of the cylinder, and then washes with water; after degreasing, a weak acid cleaning agent is used to ultrasonically derust the inner wall surface of the degreased sampling cylinder to remove metal oxides on the inner wall surface of the cylinder, and then washes with water. In one embodiment, the temperature of the degreasing treatment is 40°C to 60°C; the time of the degreasing treatment is 20min to 30min; the temperature of the derusting treatment is 40°C to 60°C; the time of the derusting treatment is 20min to 30min. In one embodiment, the non-phosphorus alkaline cleaning agent is selected from at least one of deconex 12BASIC, deconex 15PF-x, and deconex formula 1; the weak acid cleaning agent is selected from at least one of citric acid and oxalic acid. The present invention further improves the firmness of the film structure formed by condensation of SiOH groups in the silane coupling agent and MeOH groups on the metal surface in the silanization treatment by degreasing and derusting the inner wall of the steel cylinder, and the inner wall of the steel cylinder that has been degreased and derusted is easier to clean, and the inner wall is smoother without metal debris.

[0019] The present invention also provides a sampling steel cylinder, comprising a steel cylinder body and a composite film layer composited on the inner surface of the steel cylinder body; the composite film layer is obtained by treating the inner surface of the steel cylinder body with an aqueous solution of a silane coupling agent, a modifier and an alcohol solvent. The silane coupling agent, the modifier and the alcohol solvent described in the present invention are the same as those described above and will not be repeated; the treatment method is the same as the treatment method for the inner wall of the sampling steel cylinder described above and will not be repeated. The composite film layer composited on the inner surface of the steel cylinder body described in the present invention is a silane-nitride composite film layer; the silane-nitride composite film layer comprises a silane film layer and a silicon nitride film layer composited on the surface of the silane film layer. In certain embodiments of the present invention, the sampling steel cylinder comprises a steel cylinder body, a silane film layer composited on the inner surface of the steel cylinder body and a silicon nitride film layer composited on the surface of the silane film layer.

[0020] The present invention provides a silanization treatment agent for the inner wall of a sampling steel cylinder, comprising: 2wt% to 10wt% of a silane coupling agent; 10wt% to 20wt% of a modifier; 10wt% to 20wt% of an alcohol solvent; and the balance is water. The silanization treatment agent provided by the present invention can form a composite film layer on the inner surface of the sampling steel cylinder, effectively preventing the adsorption of active impurities by the inner wall of the sampling steel cylinder, while the inner wall is passivated firmly, and the long-term use of the sampling steel cylinder can be achieved. Experiments show that after the inner surface of the sampling steel cylinder is treated with the silanization treatment agent provided by the present invention, the impurity gas content of the sampling steel cylinder at different storage times is analyzed and detected. After the gas is stored in the sampling steel cylinder for 72 hours, the content of various impurity gases such as hydrogen sulfide, ethylene, formic acid, methanol and hydrogen chloride is basically unchanged. DETAILED DESCRIPTION

[0021] The present invention discloses a method for treating the inner wall of a sampling cylinder, a silanization treatment agent and a sampling cylinder. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention.

[0022] The present invention will be further described below in conjunction with embodiments:

[0023] Example 1

[0024] This embodiment provides a silanization treatment agent for the inner wall of a sampling cylinder, the treatment agent comprising: 2wt% of a silane coupling agent, 10wt% of a modifier, 10wt% of methanol, and deionized water to make up the balance to 100wt%. The silane coupling agent is specifically 0.5wt% of vinyl triethoxysilane and 1.5wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; the modifier is specifically malonic acid and glycine in a mass ratio of 1:1.

[0025] The inner wall of the sampling cylinder is treated with the above-mentioned treatment agent according to the following treatment process:

[0026] Step 1: Pre-degreasing the inner wall of the sampling cylinder, using Deconex 12BASIC to ultrasonically degrease the inside of the cylinder for 30 minutes at a solution temperature of 60°C to remove residual lipid pollutants on the inner wall of the cylinder, and then washing with water after degreasing;

[0027] Step 2: pre-rust removal treatment of the inner wall of the sampling cylinder, using citric acid at a dissolving temperature of 60°C to perform ultrasonic rust removal treatment on the inner wall of the cylinder obtained in step 1 for 30 minutes to remove the metal oxide inside the cylinder, and then washing with water after rust removal;

[0028] Step 3: The inner wall of the sampling cylinder is subjected to silanization treatment. The cylinder obtained in step 2 is immersed in the above-mentioned silanization treatment agent and the silanization treatment is performed for 10 minutes;

[0029] Step 4: Curing treatment: placing the steel cylinder after silanization treatment obtained in step 3 in a vacuum drying oven at 120° C. for curing treatment for 1 hour;

[0030] Step 5: high temperature furnace annealing treatment, the sampling cylinder obtained in step 4 is sent into a nitrogen atmosphere heating furnace to control the furnace temperature at 500 ° C for decarburization and dehydrogenation for 2 hours, a silicon nitride layer is formed on the surface of the silanized film layer, and finally a silane-silicon nitride composite film layer is formed.

[0031] The sample cylinders obtained by the above process steps were sampled and analyzed, and the storage time in the cylinders was 12 hours, 24 hours and 48 hours. The impurity content in the gas was analyzed by chromatographic detection, and the test results are shown in Table 1, which is a table of analysis and detection data of different storage times of cylinders after the process of Example 1.

[0032] Table 1 Analysis and test data of different storage time

[0033]

[0034] As can be seen from Table 1, the impurities detected in the gas are within 5% of the corresponding deviation of the corresponding values ​​of the chromatogram, which can determine that the gas is not adsorbed in the sampling cylinder.

[0035] Example 2

[0036] This embodiment provides a silanization treatment agent for the inner wall of a sampling steel cylinder, the treatment agent comprising: 10wt% of a silane coupling agent, 20wt% of a modifier, 20wt% of methanol, and deionized water to make up the balance to 100wt%. The silane coupling agent is specifically 2wt% of vinyl triethoxysilane and 8wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; the modifier is specifically malonic acid and glycine in a mass ratio of 1:1.

[0037] The inner wall of the sampling cylinder is treated with the above-mentioned treatment agent according to the following treatment process:

[0038] Step 1: Pre-degreasing the inner wall of the sampling cylinder, using a phosphorus-free alkaline cleaning agent at a temperature of 60°C to ultrasonically degrease the inside of the cylinder for 30 minutes to remove residual lipid pollutants on the inner wall of the cylinder, and then washing with water after degreasing;

[0039] Step 2: Pre-rust removal treatment of the inner wall of the sampling cylinder, using a weak acid cleaning agent at a dissolving temperature of 60°C to perform ultrasonic rust removal for 30 minutes on the inner wall of the cylinder obtained in step 1 to remove the metal oxide inside the cylinder, and then washing with water after rust removal;

[0040] Step 3: Silanization treatment, immersing the steel cylinder obtained in step 2 in a silanization treatment agent, and silanization treatment for 5 minutes;

[0041] Step 4: curing treatment, placing the steel cylinder after silanization treatment obtained in step 3 in a vacuum drying oven at 80° C. for curing treatment for 3 hours;

[0042] Step 5: high temperature furnace annealing treatment, the sampling cylinder after silanization treatment obtained in step 4 is sent into a nitrogen atmosphere heating furnace to control the furnace temperature to 800 ° C temperature range for decarburization and dehydrogenation treatment for 1 hour, a silicon nitride layer is formed on the surface of the silanization film layer, and finally a silane-silicon nitride composite film layer is formed.

[0043] The sample cylinders obtained by the above process steps were sampled and analyzed, and the storage time in the cylinders was 12 hours, 24 hours and 48 hours. The impurity content in the gas was analyzed by chromatographic detection, and the test results are shown in Table 2, which is a table of analysis and detection data of different storage times of the cylinders after the process of Example 2.

[0044] Table 2 Analysis and test data of different storage time

[0045]

[0046]

[0047] As can be seen from Table 2, the impurities detected in the gas are within 5% of the corresponding deviation of the corresponding values ​​of the chromatogram, which can determine that the gas is not adsorbed in the sampling cylinder.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for processing the inner wall of a sampling cylinder, comprising the following steps: The sampling steel cylinder is immersed in a silanization treatment agent and cured, and the obtained sampling steel cylinder is annealed to form a silane-silicon nitride composite film layer on the inner wall surface of the steel cylinder; The silanization agent comprises: 0.5 wt% vinyltriethoxysilane; 1.5 wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; 5 wt% malonic acid; 5 wt% glycine; 10 wt% methanol; The balance is water; or, 2 wt% vinyltriethoxysilane; 8 wt% of β-aminoethyl γ-aminopropyl trimethoxysilane; 10 wt% malonic acid; 10 wt% glycine; 20 wt% methanol; The balance is water.

2. The method according to claim 1, characterized in that The soaking temperature is 20°C to 40°C; The soaking time is 5 min to 10 min.

3. The method according to claim 1, characterized in that The curing temperature is 80°C to 120°C; The curing time is 1 h to 3 h.

4. The method according to claim 1, characterized in that The temperature of the annealing treatment is 500°C to 800°C; The annealing time is 1 h to 2 h.

5. A sampling cylinder, characterized in that: The method is obtained by treating a sampling cylinder using the method described in any one of claims 1 to 4.

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