Environment-friendly gas-phase composite rust inhibitor suitable for multiple metals and preparation method thereof
Technical Field
The invention relates to the field of metal rust resistance and rust resistance, in particular to an environment-friendly gas-phase composite rust inhibitor suitable for multiple metals and a preparation method thereof.
Background
The gas phase corrosion of metal is a global problem, which comprises natural gas corrosion and industrial gas corrosion, and with the development of modern industry and the improvement of the living standard of people's materials, the consumption of coal and petroleum fuels is increased, and the discharged CO is increased2、SO2、SO3And atmospheric pollutants such as oxynitride not only affect human health, but also part of acidic substances in the atmospheric pollutants can severely corrode metal equipment and equipment. The gas phase rust-resisting technology is a technology for using gas phase rust-resisting agent to make anticorrosion protection of metal, said gas phase rust-resisting agent also is called gas phase rust-resisting agent, can automatically volatilize gas and adsorb it on the surface of metal to form stable protective film, and can inhibit corrosion process by means of passivation or shielding, etcOne of the ideal means of atmospheric corrosion is widely applied to the corrosion protection of industrial equipment and parts. In the past thirty years, China experiences a rapid large-scale infrastructure stage, and then enters a maintenance stage in a period, wherein rust prevention maintenance of a large number of metal components and equipment is not lacked, and the gas-phase rust inhibitor has a good development prospect as a simple, cheap and efficient maintenance technology.
Patent CN02815037.6 discloses a vapor phase rust inhibitor and a preparation method thereof, which contains: (1) inorganic salts of nitrous acid, (2) water-soluble polysubstituted phenols, (3) aliphatic dihydroxy-benzoates, and (4) tocopherols (2, 5, 7, 8-tetramethyl-2- (4 ', 8 ', 12 ' -trimethyltridecyl) chroman-6-ol). The main component of the gas phase rust inhibitor in the patent is inorganic salt of nitrous acid, the inorganic salt of nitrous acid is strong carcinogenic substance, has very big harm to human body, along with the enhancement of people's safe environmental protection consciousness, the research and development direction begins to turn to the harmless gas phase rust inhibitor of human body of environmental protection, for example patent CN201410041375.2 discloses a green environmental protection gas phase rust inhibitor and its preparation method for carbon steel, by sodium silicate, alanine, sodium benzoate, ammonium benzoate and distilled water as the solvent composition, each component quality-volume concentration is in the gas phase rust inhibitor: 0.8g/L-1.2g/L sodium silicate, 1.8g/L-2.3g/L alanine, 6.8g/L-8.3g/L sodium benzoate and 3.8g/L-4.5g/L ammonium benzoate. Patent CN201410698364.1 discloses a copper alloy gas phase rust inhibitor and a preparation method thereof, wherein the copper alloy gas phase rust inhibitor is prepared from the following raw materials in parts by weight: 1-2 parts of benzotriazole, 2-4 parts of nutmeg oil, 1-2 parts of liquid paraffin, 1-2 parts of garlic oil, 1-2 parts of caprylic/capric glyceride, 6-8 parts of chitosan, 1-2 parts of konjac mannan, 3-5 parts of sodium benzoate, 0.2-0.4 part of nonylphenol polyoxyethylene ether, 0.3-0.5 part of petroleum sodium sulfonate, 6-8 parts of sodium tripolyphosphate, 1-2 parts of water-soluble lanolin, 8-10 parts of a modification auxiliary agent and 40-50 parts of water; the modified auxiliary agent is prepared from the following raw materials in parts by weight: 5-10 parts of medical stone powder, 3-5 parts of diatomite, 0.3-0.5 part of dodecyl trimethyl ammonium chloride, 0.2-0.4 part of tea tree oil, 0.1-0.2 part of tannic acid, 0.05-0.1 part of tocopherol and 0.1-0.2 part of isopropyl myristate. Although the above patent is safe and environment-friendly and harmless to human bodies, the protection method has strong pertinence on protected metal materials and poor universality, and can not protect various metals. Patent CN201410833287.6 discloses a phytic acid type gas phase antirust master batch, a preparation method and application thereof, wherein the mass percentages of the components are as follows: 30-50% of a compound antirust agent, 40-60% of carrier plastic and 10-20% of an auxiliary agent; the compound antirust agent is prepared from sodium benzoate, phytic acid, triethanolamine borate and monoethanolamine benzoate according to the mass ratio of 1.0-1.5: 2.5-3.2: 2.0-3.0: 1.0-1.3; the auxiliary agent is prepared from sodium silicate, silicon dioxide, stearic acid amide and an antioxidant 1076 in a mass ratio of 1.0-1.3: 5.0-6.5: 2.5-3.3: 0.8-1.1; the method for processing the phytic acid comprises the following steps: preparing a commercial phytic acid solution and distilled water into a certain concentration, adjusting the pH value of the solution to be about 9.0 by using ammonia water, distilling the solution under reduced pressure to remove a solvent, and drying the solution in vacuum at the temperature of 60 ℃. The patent can protect various metals from corrosion, but has poor rust resistance in an acidic environment.
CN103739229B is a previous patent application of the present inventor, which discloses a migration type rust inhibitor, which is prepared from the following components in parts by weight: 50-150 parts of rust-resisting component, 15-30 parts of water reducing agent, 5-45 parts of retarding component, 0.5-3 parts of air entraining component and 800 parts of water 200-plus.
In a word, the rust inhibiting effect of the gas phase rust inhibitor in the prior art needs to be improved, and particularly, the problem of developing the multi-metal broad-spectrum gas phase rust inhibitor in various special environments needs to be solved urgently.
Disclosure of Invention
Aiming at the problems that the rust inhibitor lacks wide applicability to various metals, has poor acid resistance and cannot exert excellent rust resistance under an acidic condition, the invention provides the environment-friendly gas-phase composite rust inhibitor suitable for the various metals, which has excellent rust resistance, enhanced rust resistance under the acidic condition, capability of comprehensively protecting various metals, no nitrite, safety, environmental protection and long-term gas-phase rust resistance.
The purpose of the invention is realized by the following technical scheme:
the gas-phase composite rust inhibitor suitable for multi-metal environment-friendly comprises the following components in parts by weight: 55-90 parts of amine vapor phase rust inhibitor, 1-5 parts of benzotriazole and 5-15 parts of hydrophobic modified fumed silica.
The amine gas-phase rust inhibitor is prepared from the following raw materials: hydroxypolyamine, dimethylaminopropylamine, benzoic acid, and p-aminobenzoic acid.
10-30 parts of hydroxyl polyamine, 5-10 parts of dimethylaminopropylamine, 50-70 parts of benzoic acid and 0.5-2 parts of p-aminobenzoic acid.
The structural formula of the hydroxyl polyamine is shown as the following formula (I):
wherein n is 1 to 5.
The hydrophobic modified fumed silica is high-purity white powder subjected to hydrophobic modification treatment on the surface of a silane coupling agent, and the specific surface area of the hydrophobic modified fumed silica is 100-250m2Examples include, but are not limited to, Cambot TS-530, Yingchuang AEROSILR 202, Degussa R972, and Yuejiang HL-612.
The invention also provides a preparation method of the environment-friendly gas-phase composite rust inhibitor suitable for multiple metals, which comprises the following steps:
s1: preparation of amine gas phase rust inhibitor: adding benzoic acid, hydroxyl polyamine, dimethylaminopropylamine and p-aminobenzoic acid into a reaction kettle under an inert atmosphere, reacting under a stirring condition, purifying and drying to obtain an amine gas phase rust inhibitor;
s2: fully mixing the product obtained in the step S1 with benzotriazole, grinding the mixture into powder, and taking out the powder for later use;
s3, fully mixing the powdery material obtained in the step S2 with the hydrophobic modified fumed silica.
In the S1, the reaction conditions in the reaction kettle are as follows: the pressure is 1.2-1.6MPa, the rotating speed of a stirrer used for stirring is 100-300r/min, and the reaction process comprises 2-5 times of constant-pressure drainage and is used for controlling the temperature in the reaction kettle. The reaction process of the invention is an exothermic reaction, and no external heating is needed.
And in the step of purification and drying in the step of S1, extracting the solid obtained by the reaction with diethyl ether for 12-24h, and drying in vacuum at 40-60 ℃ to finally obtain a light yellow solid amine gas phase rust inhibitor product.
And grinding in the S2 for 12-30h to finally obtain fine powder with the particle size of 10-100 nm.
The hydrophobic fumed silica in the S3 is premixed for 5-10min at 50-100r/min and then mixed for 10-30min at the rotating speed of 200-600 r/min.
The invention provides application of the gas-phase composite rust inhibitor, which is used for rust inhibition of equipment containing multiple metal products and having a complex internal space.
Compared with the prior art, the invention has the beneficial effects that:
the environment-friendly gas-phase composite rust inhibitor has wide application range and good gas-phase rust inhibiting capability on various metals including black metal and nonferrous metals such as aluminum, copper, magnesium and the like.
The composite rust inhibitor contains a self-made amine gas phase rust inhibitor, and the rust inhibiting performance in an acidic environment is not excessively and adversely affected.
Thirdly, the gas phase silicon dioxide loaded rust inhibitor has good volatility and gas phase diffusion capacity, and the rust inhibition effect of the gas phase rust inhibitor is further improved.
And fourthly, the composite rust inhibitor is safe and environment-friendly, and is suitable for long-term rust prevention.
Detailed Description
The present invention will be further described with reference to the following examples, but the present invention is not limited to the descriptions in the following. Unless otherwise specified, the parts of the reagents are parts by weight. All reagents used are commercially available in the art.
Example 1
S1: in the feeding stage, the air in the kettle is replaced by nitrogen for 3 times, so that the reaction kettle is filled with the nitrogen, and 50 parts of benzoic acid powder is added into the reaction kettle; in the reaction stage, 10 parts of hydroxyl polyamine powder (n value in the compound of the formula I is 1), 5 parts of dimethylaminopropylamine liquid and 0.5 part of para aminobenzoic acid powder are weighed and added into the reaction kettle with benzoic acid at one time, the pressure is increased to 1.2MPa, the stirring is kept at the rotating speed of 150r/min, the temperature in the reaction kettle is controlled by draining water for 3 times at constant pressure, the reaction is stopped after the temperature in the reaction kettle is reduced to the room temperature for full reaction for 4 days, and a solid is obtained; a purification stage, extracting the solid obtained in the reaction stage with ether for 24h, and vacuum-drying at 40 ℃ to obtain a light yellow solid product;
s2: adding the dried solid product obtained in the step one and 1 part of benzotriazole into a ball mill, grinding for 24 hours to obtain fine powder with the particle size of 20-30nm, and taking out for later use;
s3: 60 parts of the fine powder obtained in S2 were mixed with 5 parts of hydrophobic fumed silica of Degussa R972 (specific surface area 110 m)2And/g) are added into a stirrer together, and are premixed and mixed for 10min at the rotating speed of 50r/min and then mixed for 20min at the rotating speed of 400 r/min.
Example 2
S1: in the feeding stage, air in the kettle is replaced by nitrogen for 5 times, so that the reaction kettle is filled with nitrogen, and 60 parts of benzoic acid powder is added into the reaction kettle; in the reaction stage, 20 parts of hydroxyl polyamine powder, 8 parts of dimethylaminopropylamine liquid and 1.5 parts of para aminobenzoic acid powder are weighed and added into the reaction kettle with benzoic acid at one time, the pressure is increased to 1.3MPa, the stirring is kept at the rotating speed of 200r/min, the temperature in the reaction kettle is controlled by draining water at constant pressure for 3 times, the reaction is fully carried out for 4 days, and the reaction is stopped when the temperature in the reaction kettle is reduced to the room temperature, so that a solid is obtained; a purification stage, extracting the solid obtained in the reaction stage with ether for 24h, and vacuum-drying at 40 ℃ to obtain a light yellow solid product;
s2: adding the dried solid product obtained in the step one and 2.5 parts of benzotriazole into a ball mill, grinding for 24 hours to obtain fine powder with the particle size of 20-30nm, and taking out for later use;
s3: 60 parts of the fine powder obtained in S2 were mixed with 5 parts of hydrophobic fumed silica of Degussa R972 (specific surface area 110 m)2/g) are added into a stirrer together, premixed and mixed for 10min at the rotating speed of 50r/min and then at the rotating speed of 400r/minMixing at rotating speed for 20 min.
Example 3
The process is the same as in example 1 except that 30 parts of hydroxypolyamine, 10 parts of dimethylaminopropylamine, 70 parts of benzoic acid, 2 parts of p-aminobenzoic acid and 5 parts of benzotriazole are used.
Example 4
The procedure is as in example 1 except that 30 parts of benzoic acid is used in the production of the amine vapor phase rust inhibitor.
Example 5
The procedure is as in example 1 except that 80 parts of benzoic acid is used in the preparation of the amine vapor phase rust inhibitor.
Example 6
The same as in example 1, except that the value of n in the hydroxypolyamine represented by the formula (I) is 5.
Comparative example 1
The same as example 1 except that dimethylaminopropylamine was not added in the preparation of the amine vapor phase rust inhibitor.
Comparative example 2
The same as example 1, except that p-aminobenzoic acid was not added in the preparation of the amine vapor phase rust inhibitor.
Comparative example 3
The rest is the same as in example 1, except that the fumed silica is not hydrophobically modified.
The gas phase rust inhibitor prepared in the above examples and comparative examples was subjected to a rust inhibition efficiency test, a gas phase rust inhibition screening test and a gas phase rust inhibition capability test, and the results are shown in table 1:
and (3) rust inhibition efficiency experiment:
1. neutral salt spray testAccording to the national standard GB/T10125-2012, sodium chloride is dissolved in deionized water, the mass concentration is (50 +/-5) g/L, the temperature is 35 ℃, the pH value collected after spraying is 6.5-7.2, 24h is an observation period, intermittent spraying is carried out for 8h and is stopped for 16h, the experiment of 15d is carried out, corrosion products are removed, the mixture is washed, dried and weighed,and calculating the rust resistance rate.
The rust inhibition rate is calculated according to the following formula:
R=(△G0-△Gi1)/△G0×100%
wherein R is the rust resistance (%); delta G0The mass difference (g) between the before and after the experiment of the pig iron sample without adding the gas phase rust inhibitor is as follows: delta Gi1The mass difference (g) between the sample added with the gas phase rust inhibitor before and after the test.
2、Acetic acid salt spray testReferring to the national standard GB/T10125-2012, the difference is that a proper amount of glacial acetic acid is added into the salt solution to ensure that the pH value of the collected solution is 3.1-3.3, the collected solution is taken out and weighed every 24 hours, the experiment time is 240 hours, corrosion products are removed, and the corrosion inhibition rate is calculated after the collected solution is washed, dried and weighed.
The rust inhibition rate is calculated according to the formula:
R=(△G0-△Gi1)/△G0×100%
wherein R is the rust resistance (%); delta G0The mass difference (g) between the before and after the experiment of the pig iron sample without adding the gas phase rust inhibitor is as follows: delta Gi1The mass difference (g) between the sample added with the gas phase rust inhibitor before and after the test.
Gas-phase rust-proof screening experiment:the method is used for checking the non-contact protection capability of the gas phase antirust agent on different metals under the conditions of high temperature and high humidity.
The test is carried out according to JB/T6071-1992 technical conditions of gas phase rust inhibitor: 1g of the gas phase rust inhibitor is uniformly distributed on a shallow vessel, and then the shallow vessel is placed in a conical flask. A50 mm. times.25 mm. times.2 mm test piece was hung in a conical flask. Placing the conical flask into a 50 ℃ oven for constant temperature saturation for 2h, then injecting 15ml of distilled water into the conical flask by using a pipette, placing the conical flask into a 50 ℃ incubator, keeping the humidity RH equal to or more than 90%, and keeping the temperature for 8h every day. The corrosion was recorded by observing 1 time per day for a period of one day, and the earliest occurrence of corrosion was recorded.
Gas phase rust inhibition ability experiment:the method is used for simulating the evaluation of the gas-phase rust-proof capability of the gas-phase rust inhibitor in a specified time under the normal-temperature condensation condition.
The test is carried out according to JB/T6071-1992 technical conditions of gas phase rust inhibitor: pressing the polished 45# steel test piece into a rubber stopper, wherein the exposed height of the test piece surface is not more than 3mm, degreasing with diethyl ether, blow-drying with cold air, injecting 10ml of 35% glycerol aqueous solution into a 1000ml wide-mouth bottle, and controlling the relative humidity in the bottle to be 90%. 0.5g of the gas phase rust inhibitor was uniformly spread on a culture dish having a diameter of about 40m and the dish was placed in a people jar. Then the whole experimental device is placed in a constant temperature bath at (20 +/-2) DEG C, ice water at 20 ℃ is filled in an aluminum pipe at the upper part of the test piece after 20h, the device is placed at (20 +/-2) DEG C and kept for 3h, the test piece is taken out and scrubbed by an alcohol cotton ball, and the surface of the test piece is immediately checked for corrosion after being dried.
TABLE 1
As can be seen from the above table, the gas phase rust inhibitor provided by the invention has good rust inhibiting and rust preventing effects on various metals including 45# steel, red copper, aluminum-magnesium alloy, pig iron and the like, also has a good slow release effect under an acidic condition, has a rust inhibiting rate of more than 85%, does not cause corrosion on the surface of the metal in a gas phase rust inhibiting capability test, and is suitable for long-term rust prevention of multiple metals.
The above detailed description is specific to one possible embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention should be included in the technical scope of the present invention.