JP2011047028A - Composition of volatile corrosion inhibitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition of a volatile corrosion inhibitor, which effectively exerts an antirust effect on metal for a long period of time by generating ammonia gas, and is highly safe for the human body. <P>SOLUTION: The solid composition of the volatile corrosion inhibitor includes a not-self-decomposable ammonium salt as a component A, and a non-deliquescent salt of an alkali metal and/or an alkaline earth metal as a component B, and does not include a nitrous acid and a salt thereof. The mass ratio of the component A to the component B is in the range of 1/10 to 10/1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vaporizable rust inhibitor composition having a rust preventive effect on metals.

  Conventionally, application of rust preventive oil and vaporizable rust preventive are known as rust preventive means for metal products. Rust preventive oil and vaporizable rust preventives are used to prevent metal surfaces from oxidizing and rusting when storing and transporting metal automobile parts such as steel and various machine parts. In particular, in recent years, vaporizable rust preventives that exhibit an excellent rust preventive effect in a small amount and can be easily removed after use have been widely put into practical use.

As a vaporizable rust inhibitor, diisopropylamine nitrite [((CH ₃ ) ₂ CH) ₂ NH · HNO ₂ : DIPAN] is known. However, although diisopropylamine nitrite is satisfactory in terms of rust prevention effect, there is a problem that when it is left in the air, diisopropylnitrosamine, which is a dehydrated product, is generated and has carcinogenic properties. In addition, dicyclohexylamine nitrite [(C ₆ H ₁₁ ) ₂ NH · HNO ₂ : DICHAN] is also known as a vaporizable rust preventive, but dicyclohexylamine nitrite has no carcinogenicity, The vaporization property is low, and the rust prevention effect may be insufficient.

  Patent Document 1 discloses that ammonium carbonate, ammonium sesquicarbonate, or ammonium hydrogen carbonate is used as a vaporizable rust inhibitor for steel. The vaporizable rust preventive disclosed in Patent Document 1 generates ammonia gas to prevent rusting of steel, but is highly self-decomposable and quickly vaporizes and disappears when exposed to the environment. Resulting in. In addition, ammonia gas is generated regardless of temperature and humidity, and it is difficult to control the generation of ammonia gas.

JP-A 61-26789

  The present invention has been made in view of the above circumstances, and an object thereof is a vaporizable rust preventive composition that generates ammonia gas and exhibits a rust preventive effect on a metal, and effectively prevents rust over a long period of time. An object of the present invention is to provide a vaporizable rust preventive composition that exerts an effect and has high safety to the human body.

  The vaporizable rust preventive composition of the present invention capable of solving the above-mentioned problems is a non-self-decomposable ammonium salt as component A and a non-deliquescent alkali metal salt and / or alkaline earth as component B. It contains a metal salt, does not contain nitrous acid or its salt, has a mass ratio of the component A to the component B in the range of 1/10 to 10/1, and is characterized by being a solid. In the vaporizable rust preventive composition of the present invention, the component B reacts with moisture in the air and exhibits neutrality to alkalinity in the environment where the metal is easily rusted due to the above-described configuration. Generation | occurrence | production of the ammonia gas which originates in and has a rust prevention effect is accelerated | stimulated. On the other hand, in a low-humidity environment where the metal is not easily rusted, the reaction between component B and moisture in the air is suppressed, and as a result, ammonia gas is less likely to be generated from component A. Therefore, the vaporizable rust preventive composition of the present invention can effectively prevent metal from being rusted, and the rust preventive effect lasts for a long time. In addition, since it does not contain nitrite or its salt, there is no concern about carcinogenicity derived from nitrosamine, and safety to the human body is high.

  As the component A, ammonium sulfate, ammonium hydrogen sulfate, ammonium sulfite, ammonium amidosulfate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium nitrate, ammonium borate, diammonium citrate, ammonium hydrogen citrate, ammonium adipate, At least one selected from the group consisting of ammonium acetate, ammonium benzoate, ammonium tartrate, ammonium hydrogen tartrate, ammonium succinate, ammonium formate, ammonium lactate, ammonium oxalate, ammonium salicylate, and diammonium ethylenediaminetetraacetate is preferred. The component B includes calcium hydroxide, magnesium oxide, magnesium hydroxide, sodium carbonate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium borate, and sodium metaborate. At least one selected from is preferred. Particularly preferably, the component A is at least one selected from the group consisting of diammonium hydrogen phosphate and ammonium benzoate, and the component B is selected from the group consisting of calcium hydroxide, magnesium oxide, and sodium carbonate. At least one selected. By appropriately selecting the compounds of component A and component B as described above, a vaporizable rust preventive composition that is highly safe and easy to handle can be obtained.

  The vaporizable rust preventive composition of the present invention promotes the generation of ammonia gas having a rust-preventing effect in a high humidity environment where the metal is easily rusted, and generates ammonia gas in a low humidity environment where the metal is not easily rusted. Therefore, the metal can be effectively rust-prevented, and the rust-preventing effect can be maintained over a long period of time. Moreover, the safety to the human body is high.

  The vaporizable rust preventive composition of the present invention contains a non-self-decomposable ammonium salt as component A and a non-deliquescent alkali metal salt and / or alkaline earth metal salt as component B, and contains nitrous acid or The salt is not contained, the mass ratio of the component A to the component B is in the range of 1/10 to 10/1, and is solid.

  First, the non-self-decomposable ammonium salt used as component A will be described. The ammonium salt is not particularly limited as long as it is non-self-decomposable and has an ammonium ion as a cation. The anion as a counter ion is not particularly limited. In the vaporizable rust preventive composition of the present invention, the ammonia gas generated from the ammonium salt exhibits a rust preventive effect on the metal.

  In the present invention, the non-self-decomposable ammonium salt is preferably an ammonium salt having a residual ratio of 90% by mass or more when left in the air at 60 ° C. for 24 hours. If a non-self-decomposable ammonium salt is used as Component A, a vaporizable rust preventive composition that can easily control the generation of ammonia gas can be obtained. That is, it is possible to obtain a vaporizable rust preventive composition that is less likely to generate ammonia gas in a low humidity environment where the metal is less likely to rust, and more likely to generate ammonia gas in a higher humidity environment where the metal is more likely to rust.

  As the non-self-decomposable ammonium salt, an ammonium salt having no carbonate ion or hydrogen carbonate ion as a counter ion is preferably employed. Since ammonium salts having carbonate ions or hydrogen carbonate ions are easily self-decomposed, ammonia gas is easily generated under low and high humidity conditions, and it is difficult to control the generation of ammonia gas. Examples of the ammonium salt having carbonate ion or hydrogen carbonate ion include ammonium carbonate, ammonium sesquicarbonate, ammonium carbamate, and ammonium hydrogen carbonate.

  Ammonium salts are non-self-degradable and relatively easy to obtain and handle. Ammonium sulfate, ammonium hydrogen sulfate, ammonium sulfite, ammonium amidosulfate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium nitrate, boric acid Ammonium, diammonium citrate, ammonium hydrogen citrate, ammonium adipate, ammonium acetate, ammonium benzoate, ammonium tartrate, ammonium hydrogen tartrate, ammonium succinate, ammonium formate, ammonium lactate, ammonium oxalate, ammonium salicylate, and ethylenediamine tetra It is preferable to use at least one selected from the group consisting of diammonium acetate. These ammonium salts may use only 1 type and may use 2 or more types together. Among these, diammonium hydrogen phosphate and ammonium benzoate are preferably used because they are highly safe and the counter-ion phosphoric acid and benzoic acid are less corrosive as acids. For example, diammonium hydrogen phosphate is used as a food additive, and benzoic acid and ammonia, which are raw materials of ammonium benzoate, are also used as a food additive, and its safety is widely recognized.

  Next, the non-deliquescent alkali metal salt and / or alkaline earth metal salt used as component B will be described. The vaporizable rust preventive composition of the present invention generates ammonia gas derived from the ammonium salt of component A, and this ammonia gas exhibits a rust preventive effect on metals. In general, rust is unlikely to occur in metal in a low humidity environment, and rust is likely to occur in a high humidity environment. Therefore, if the vaporizable rust preventive composition can suppress the generation of ammonia gas in a low-humidity environment and promote the generation of ammonia gas in a high-humidity environment, it can effectively rust prevent metals. And the rust preventive effect will last for a long time. Therefore, the vaporizable rust preventive composition of the present invention has, as Component B, a non-deliquescent alkali metal salt and / or alkaline earth metal salt.

  Alkali metal salts and alkaline earth metal salts generally exhibit neutrality to alkalinity when dissolved in water. On the other hand, the ammonium salt used as component A is generally decomposed and promoted to generate ammonia gas as the pH becomes higher. Therefore, the vaporizable rust preventive composition of the present invention has a neutral to alkaline reaction when component B reacts with moisture in the air under a high humidity environment. As a result, ammonia gas is derived from component A. The generation of rust is promoted, and the rust prevention effect is enhanced. On the other hand, in a low humidity environment, reaction between component B and moisture in the air is suppressed, and as a result, ammonia gas derived from component A is less likely to be generated.

  The alkali metal salt and / or alkaline earth metal salt used as component B is not particularly limited as long as it is non-deliquescent. Deliquession generally occurs when the water vapor pressure of a saturated aqueous solution of a substance is less than the partial pressure of atmospheric water vapor in contact with it. In the present invention, the non-deliquescent alkali metal salt and / or alkaline earth metal salt is water having a water vapor pressure of 40 ° C. in a saturated aqueous solution of the alkali metal salt and / or alkaline earth metal salt used as Component B. It is preferable that the compound has a vapor pressure of less than 55 Torr (7.3 kPa).

  If a deliquescent alkali metal salt and / or alkaline earth metal salt is used, component B is easy to absorb moisture in the air even in a low humidity environment, and low humidity is unlikely to cause metal rusting. Even in the environment, ammonia gas is likely to be generated from component A. In this case, the rust preventive agent is consumed even under conditions where rust prevention is unnecessary, which is inefficient. In addition, when using the vaporizable rust inhibitor composition, the vaporizable rust inhibitor composition becomes liquid and handling properties deteriorate, or the liquid vaporizable rust inhibitor composition hangs down on the metal product. May adversely affect metal products.

  However, since the vaporizable rust preventive composition of the present invention uses a non-deliquescent alkali metal salt and / or alkaline earth metal salt as the component B, the component B is in the air under a low humidity environment. It is difficult to absorb moisture, and ammonia gas derived from component A is less likely to be generated in a low humidity environment. Therefore, it is possible to efficiently prevent the metal from being rusted. That is, the vaporizable rust preventive composition of the present invention does not contain a deliquescent alkali metal salt or a deliquescent alkaline earth metal salt.

  The alkali metal salt and / or alkaline earth metal salt used as component B is preferably a salt that dissolves in water and exhibits alkalinity from the viewpoint of facilitating generation of ammonia gas. Specifically, as component B, considering availability and handling ease, calcium hydroxide, magnesium oxide, magnesium hydroxide, sodium carbonate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, tripolylin It is preferable to use at least one selected from the group consisting of sodium acid, sodium borate, and sodium metaborate. These alkali metal salts or alkaline earth metal salts may be used alone or in combination of two or more. Among these, calcium hydroxide, magnesium oxide, and sodium carbonate are preferably used in terms of high safety such as being used as food additives.

  The vaporizable rust preventive composition of the present invention preferably contains Component A and Component B in a uniform mixed state. Specifically, the vaporizable rust preventive composition is preferably obtained by uniformly mixing the powdery component A and the powdery component B. When component A and component B are contained in a mixed state, ammonia gas derived from component A is likely to be generated quickly following moisture absorption of component B. The vaporizable rust preventive composition of the present invention may be in powder form as long as it contains component A and component B in a uniform mixed state, granulated by any method, or any method. The pellet shape etc. which were shape | molded with may be sufficient.

  Component A and component B are preferably used as a raw material for the vaporizable rust preventive composition, and the ratio of passing through a sieve having an aperture of 2.00 mm (9 mesh) is preferably 90% by mass or more, and 95% by mass. The above is more preferable, and 100% by mass is even more preferable. That is, the powdery degree of component A and component B may be a particle size that most passes through a sieve having an aperture of 2.00 mm (9 mesh), and component A and component B of the particle size are It is preferable that they are mixed uniformly.

  The vaporizable rust preventive composition of the present invention contains component A and component B in a mass ratio (A / B) of component A to component B in the range of 1/10 to 10/1. The mass ratio of component A to component B is preferably 1/5 or more, more preferably 1/3 or more, and is preferably 5/1 or less, more preferably 3/1 or less. If the mass ratio of component A to component B is less than 1/10, the amount of ammonium salt (component A) contained in the vaporizable rust preventive composition is reduced, and ammonia gas necessary for rust prevention is sufficiently generated. Or a large amount of a vaporizable rust preventive composition may be required. If the mass ratio of component A to component B exceeds 10/1, the amount of non-deliquescent alkali metal salt and / or alkaline earth metal salt (component B) contained in the vaporizable rust preventive composition is small. Therefore, there is a risk that ammonia gas necessary for rust prevention is not sufficiently generated, or an unreacted ammonium salt (component A) increases, resulting in inefficiency.

  As described above, the vaporizable rust preventive composition of the present invention contains a non-self-decomposable ammonium salt as component A and a non-deliquescent alkali metal salt and / or alkaline earth metal salt as component B. To do. However, the vaporizable rust preventive composition of the present invention does not contain nitrous acid or a salt thereof. This is because a vaporizable rust preventive containing nitrous acid or a salt thereof may generate nitrosamine having harmfulness such as carcinogenicity. Therefore, the vaporizable rust preventive composition of the present invention that does not contain nitrous acid or a salt thereof has no concern about carcinogenicity derived from nitrosamine, and has high safety to the human body.

  The vaporizable rust preventive composition of the present invention may further contain at least one selected from the group consisting of benzotriazole and tolyltriazole. If the vaporizable rust preventive composition further contains benzotriazole or tolyltriazole, discoloration of non-ferrous metals such as copper and copper alloys can be prevented, and the corrosion effect can be enhanced. Moreover, the vaporizable rust preventive composition may contain a binder, an extender, a pigment, a coloring matter, and the like, if necessary.

  The vaporizable rust preventive composition of the present invention is solid at normal temperature and normal pressure (25 ° C., 1 atm). The vaporizable rust preventive composition simply generates a rust preventive effect on metals, particularly steel, by generating ammonia gas having a rust preventive effect according to the humidity in the atmosphere. Moreover, since the vaporizable rust preventive composition does not have deliquescence and is a solid, it is easy to handle.

  When using the vaporizable rust preventive composition of the present invention, it may be used as it is, but in order to improve the handleability, such as a breathable nonwoven fabric, a perforated film or an open-cell type foam film It is preferable to use an appropriate amount packaged in a bag made of a breathable film. The kind of non-woven fabric or breathable film used here is not particularly limited. Non-woven fabrics such as ordinary vegetable fiber, animal fiber, regenerated fiber, synthetic fiber, etc., as long as it allows passage of gas having a rust preventive effect while preventing leakage of the vaporizable rust preventive composition Resin continuous foam sheets, perforated films, and the like can be used.

  Before using the vaporizable rust inhibitor composition, the bag containing the vaporizable rust inhibitor composition or vaporizable rust inhibitor composition is impermeable to water vapor such as polyethylene, polyester, polypropylene, polystyrene, polycarbonate, polyimide, etc. It is better to seal or store or transport the film or metal can in a water-resistant film or metal can, and use it after opening the film or can. By sealing and storing the vaporizable rust preventive composition, component B is prevented from absorbing moisture in the air during storage, and deterioration of the function as a rust preventive can be prevented.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited thereto.

(1) Preparation of vaporizable rust preventive composition According to the blending ratio shown in Tables 1 and 2, the vaporizable rust preventive composition No. 1-13 were produced. In Table 1, diammonium hydrogen phosphate and ammonium benzoate correspond to Component A, and magnesium oxide, calcium hydroxide, and sodium carbonate correspond to Component B.

  Each reagent was powdery or crystalline. Diammonium hydrogen phosphate is used for food additives manufactured by Taihei Chemical Industry Co., Ltd., ammonium benzoate, ammonium carbonate and ammonium hydrogen carbonate are reagent grades manufactured by Kanto Chemical Co., Ltd., and magnesium oxide is Kyowa Chemical Industry Co., Ltd. Calcium hydroxide is used for food additives manufactured by Tomita Pharmaceutical Co., Ltd., and sodium carbonate is used for food additives manufactured by Soda Ash Japan Co., Ltd., and benzotriazole and DICHAN (dicyclohexylamine) Nitrite) was manufactured by Kirest Co., Ltd.

(2) Test method (2-1) Rust prevention test The vaporizable rust inhibitor composition prepared in (1) above was weighed out into a non-woven bag and sealed in a predetermined amount shown in Table 1. Then, a rust preventive bag was obtained. An acrylic resin (PMMA) container with a 60 mm diameter hole on the upper surface (As One Co., Ltd., portable desiccator standard PL, outer dimensions 400 mm x 317 mm x 338 mm, capacity 33 L) is installed in a thermostat adjusted to 20 ° C. Then, the rust preventive bag was suspended almost in the middle of the container. The hole on the upper surface of the container was plugged with a rubber stopper with a test piece prepared according to JIS Z 1519-1994 5.4 “Vaporization and rust prevention”. The rubber plug with the test piece is an aluminum tube that penetrates the rubber plug, and a test piece (general steel material SGB3 for polished steel bars) is attached to one end of the aluminum pipe, and the test piece is in contact with the atmosphere in the container. It was. Note that the aluminum tube and the test piece were both fixed by a separate perforated rubber stopper. At the bottom of the container, 200 mL of 35% glycerin water was added, and the inside of the container was adjusted to a relative humidity of 90%. In accordance with JIS Z 1519-1994 5.4 “Vaporization and rust prevention” 5.4.5 “Operation”, let stand at 20 ° C. for 20 hours, then put cold water of 0 ° C. to 2 ° C. into aluminum tube and test Condensation was generated on the piece, and after standing at 20 ° C. for 3 hours, the state of rust generation on the test piece was confirmed with a 5-fold magnifier. The evaluation of the rust occurrence state is shown in the column of “rust prevention test” in Tables 1 and 2 in accordance with the following criteria.
◎: No corrosion, no discoloration ○: Slight corrosion or point rust occurs 1-3, discoloration area less than 10% △: Mild corrosion or point rust occurs 4-9, discoloration area 10% or more Less than 30% ×: 10 or more clear corrosion or point rust occurs, discoloration area is 30% or more and less than 50% XX: Overall corrosion, discoloration area is 50% or more

(2-2) Measurement of ammonia gas concentration during rust prevention test In the above rust prevention test, when 20 hours had elapsed, a gas detector tube (for ammonia, No. 3L, 3La, 3M) made of acrylic was used. The ammonia gas concentration in the resin container was measured. The results are shown in the column of “Ammonia gas concentration” in Tables 1 and 2.

(2-3) Effect of temperature and humidity on ammonia gas generation amount Composition No. 0.10 g of 1, 5, 12 or 13 vaporizable rust inhibitor composition was placed in a 30 mL beaker and placed inside a 1 L test bottle. 10 mL of glycerin water was added to the lower part of the test bottle to adjust the humidity inside the test bottle. The test bottle was sealed with a rubber stopper and allowed to stand at 20 ° C., 30 ° C. or 40 ° C. for 20 hours, and then the ammonia gas concentration in the test bottle was adjusted to a gas detection tube (for ammonia, No. 3L, 3La, 3M, 3HM). The concentration of glycerin water for humidity adjustment is 86.2% by mass on the condition of 40RH% relative humidity, 80.4% by mass on the condition of 50RH% relative humidity, 72.7% by mass on the condition of relative humidity 60RH%, relative The content was 64.1% by mass under the condition of 70RH% humidity, 51.5% by mass under the condition of 80RH% relative humidity, and 34.7% by mass under the condition of 90RH% relative humidity. The results are shown in Table 3.

(2-4) Stability evaluation Composition No. 1, 12 or 13 vaporizable rust preventive composition was put into a 100 mL beaker, and this was put into a 60 degreeC thermostat, and the mass change with progress of time was seen. The results are shown in Table 4. In Table 4, the initial mass is 100%, and the mass at each elapsed time is expressed as a percentage.

(3) Test results In the rust prevention test results shown in Tables 1 and 2, No. 1 in which the vaporizable rust inhibitor composition was not installed in the container. In No. 14, the evaluation of the rust prevention test was “XX”. On the other hand, composition No. which contains component A and component B in the range of mass ratio 1/10 to 10/1. As for 1-8, the quantity of 2g or 4g was installed in the container, and the evaluation of the rust prevention test was "(double-circle)". In addition, the ammonia gas concentration when the evaluation was “◎” was at least 23 ppm (Composition No. 4). Although it contains component A and component B, composition No. in which the mass ratio of component A to component B is outside the range of 1/10 to 10/1. 9 and 10, even if an amount of 10 g was placed in the container, the ammonia gas concentration was 11 ppm at the highest, and the evaluation of the rust prevention test was “Δ” or “×”. DICHAN (Composition No. 11) frequently used as a general vaporizable rust preventive was evaluated as “Δ” even when an amount of 10 g was placed in the container.

  Composition No. using ammonium carbonate or ammonium bicarbonate In Nos. 12 and 13, the generation of sufficient ammonia gas was observed in the results of the rust prevention tests shown in Tables 1 and 2, and the evaluation of the rust prevention test was “◎”. However, generation of a large amount of ammonia gas was observed even in a low-temperature and low-humidity environment, and the stability (non-self-decomposability) was not sufficient. This will be described with reference to Tables 3 and 4.

  Table 3 shows composition no. About the vaporizable rust preventive composition of 1,5,12,13, the result of having investigated the influence of the temperature and humidity of ammonia gas generation amount was shown. Composition No. In Nos. 1 and 5, the amount of ammonia gas generated was small in a low-temperature and low-humidity environment where rusting was difficult, and the amount of ammonia gas generated increased as the temperature and humidity increased. On the other hand, composition no. In Nos. 12 and 13, generation of a large amount of ammonia gas was observed even in a low temperature and low humidity environment of 20 ° C. and 40 RH%. That is, the composition No. 12 and 13 were found to be inefficient as rust inhibitors.

  Table 4 shows composition no. The result of the stability evaluation test of the vaporizable rust preventive composition of 1,12,13 was shown. Composition No. No. 1 showed a high stability with almost no decrease in mass even after 120 hours. On the other hand, composition no. 12 disappeared almost completely in 18 hours. 13 almost disappeared in 24 hours and almost completely disappeared in 120 hours. That is, the composition No. 12 and 13 were found to be inferior in stability (non-self-decomposability).

  The vaporizable rust inhibitor composition of the present invention can be applied to metal rust prevention applications.

Claims (4)

A non-self-decomposable ammonium salt as component A and a non-deliquescent alkali metal salt and / or alkaline earth metal salt as component B;
Does not contain nitrous acid or its salts,
Solid vaporizable rust preventive composition, wherein mass ratio of component A to component B is in the range of 1/10 to 10/1.   Component A is ammonium sulfate, ammonium hydrogen sulfate, ammonium sulfite, ammonium amidosulfate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium nitrate, ammonium borate, diammonium citrate, ammonium hydrogen citrate, ammonium adipate, acetic acid 2. At least one selected from the group consisting of ammonium, ammonium benzoate, ammonium tartrate, ammonium hydrogen tartrate, ammonium succinate, ammonium formate, ammonium lactate, ammonium oxalate, ammonium salicylate, and diammonium ethylenediaminetetraacetate. The vaporizable rust preventive composition described in 1.   Component B is selected from the group consisting of calcium hydroxide, magnesium oxide, magnesium hydroxide, sodium carbonate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium borate, and sodium metaborate. The vaporizable rust preventive composition according to claim 1 or 2, which is at least one selected. Component A is at least one selected from the group consisting of diammonium hydrogen phosphate and ammonium benzoate,
The vaporizable rust preventive composition according to claim 1, wherein the component B is at least one selected from the group consisting of calcium hydroxide, magnesium oxide, and sodium carbonate.