JPH10114892A - Vaporizable rust-preventive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vaporizable rust preventive composition which can be easily handled, does not stain the substrate and can prevent the substrate from being rusted without fail by mixing a nitrate with a pH buffer, benzotriazole and a resin powder. SOLUTION: This preventive is prepared by uniformly mixing a nitrate (A) with a pH buffer (B), benzotriazole or its derivative (C) and a resin powder (D) and desirably molding the resulting mixture into granules or tablets. Component A is selected among sodium, potassium and calcium nitrates. Component B is selected among boric acid, phosphoric acid, phthalic acid, citric acid, lactic acid, etc. Component C is benzotriazole or tollyltriazole. Although not particularly limited, component D is a polyethylene or polypropylene powder having a particle diameter of about 50-300μm for the sake of pressability. The mixing ratio is preferably such that 5-20wt.% component A, 0.1-5wt.% component B, 5-20wt.% component C and 50-80wt.% component D are used. This preventive exhibits a persistent rust-preventive effect when it is packed into a gas- permeable bag, and this bag is put in e.g. a packaging bag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for storing, transporting, or exporting machinery, equipment and parts made of iron or steel, or non-ferrous metals such as copper and Al which are susceptible to oxidation. The present invention relates to a vaporizable rust-preventive composition for preventing oxidization and rusting, and more particularly to a vaporizable rust-preventive composition that is easy to handle and that stably maintains an excellent rust-preventive effect.

[0002]

2. Description of the Related Art A vaporizable rust preventive is a rust preventive component that evaporates from the rust preventive by inserting a vaporizable rust preventive into the internal space of the package when the object to be rust-proofed is packed. Is chemically or physically adsorbed on the surface of the object to be rust-prevented, thereby preventing oxidation (corrosion) due to oxygen or moisture in the atmosphere. It is widely used for rust prevention control during storage, transportation, and export of machinery and equipment that cannot be performed, precision equipment and electronic components.

[0003] However, since ordinary vaporizable rust preventives volatilize at room temperature and exhibit a rust preventive effect, powdery or liquid vaporizable rust preventives are directly sprayed or coated on the rustproof material. If so, the rust-preventive component volatilizes in a short period of time and loses the rust-preventive effect. Also, in the case of powdery or liquid vaporizable rust preventive, it takes time and effort to spray or apply it to the rust-prevented material, and when the carrier component of the rust-preventive component adheres to the surface of the rust-prevented material, In particular, it may cause a malfunction in precision equipment and the like. In addition, for machines and instruments,
In many cases, a single machine / equipment is constructed by incorporating a plurality of different types of metal members for each part. Such a machine / equipment etc. effectively exhibits the rust-preventive effect for each combined metal. Sometimes it is necessary to use more than one rust inhibitor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to maintain an excellent rust prevention effect over a long period of time and It is easy to handle, does not contaminate the rust-proof material, and even if it is a machine / apparatus etc. incorporating different types of metal materials, it is a vaporizable rust preventive that can reliably protect rust. It is intended to provide a composition.

[0005]

The vaporizable rust preventive composition of the present invention which can solve the above-mentioned problems includes nitrite, p
Its feature resides in containing H buffer, benzotriazole or its derivative and resin powder. Preferred nitrites used herein include sodium nitrite, potassium nitrite, and calcium nitrite, and preferred benzotriazoles or derivatives thereof include benzotriazole and tolyltriazole, each of which can be used alone. If necessary, two or more kinds can be used in combination. Preferred examples of the pH buffer include boric acid, phosphoric acid, phthalic acid, citric acid, succinic acid, tartaric acid, lactic acid and salts thereof, and these can be used alone or in combination of two or more.

The vaporizable rust preventive composition according to the present invention can be put into practical use by inserting a homogeneous mixture of the above components in a powdered state into a breathable bag such as a nonwoven fabric so as not to be scattered. It is preferable to form them into granules or tablets because handling can be further facilitated.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, in the present invention, nitrite, a pH buffer and benzotriazole or a derivative thereof are used in combination as rust preventive components, and they are uniformly mixed with resin powder. If it is put into a breathable bag as it is in a powder state, or if it is made into granules or tablets and then put into practical use, it is easier to handle than a liquid vaporizable rust inhibitor. In addition to this, there is no risk of contaminating the rust-proof material. In addition, a rust-preventive component is mixed with the resin powder to generate rust-preventive gas. This rust-preventive gas is gradually dissipated from the gap between the resin powders, and can maintain an excellent rust-preventive effect for a long time. It will be.

The nitrite used as one of the rust-preventing components in the present invention does not itself have a vaporizing property.
As it is, it does not work effectively as a vaporizable rust inhibitor,
Hydrolysis, in the presence of carbon dioxide as a moisture and acid components in the atmosphere, NO ₂ exhibits excellent anticorrosive effect against iron and steel materials ^- generates gas, exhibits whereby excellent corrosion protection I do. However, since the amount of carbon dioxide gas in the air is very small, the amount and rate of generation of NO ₂ ^- gas as it is without nitrite is small, and thus lacks immediate effect as a rust inhibitor. However, it has been confirmed that when a suitable amount of a pH buffer is contained together with nitrite, the above-mentioned hydrolysis reaction rate is accelerated and the immediate effect as a rust inhibitor is enhanced.

The reason is considered as follows. That nitrite can undergo hydrolysis in the presence of water and acidic components as described above NO ₂ ^- to produce a gas, but as it has a low carbon dioxide concentration in the air causes throat proceed hydrolysis N殆And lacks the immediate effect of rust prevention. Therefore, when'll mixing an acidic component to nitrite NO ₂ ^- gas generating reaction is significantly accelerated immediate is increased, the acidity of the acidic substance is too strong hydrolysis of nitrite occur instantaneously, immediate effect is Although it can be enhanced, the sustainability cannot be obtained. However, when a substance which exhibits a pH buffering action in the acidic range in combination with nitrite, a sudden change in pH is suppressed by the action of the buffer, the results of suppressed progression of the hydrolysis reaction of nitrite with it, NO ₂ ^- gas will be little by little discharged, it is believed to exhibit combined persistence and fast-acting rust effect.

In addition, the granules or tablets are formed in a state where the rust-preventive component is mixed with a resin powder which does not contribute to rust prevention. The rust-preventive gas is released from the gaps while gradually hydrolyzing due to the invading water. It is possible to remarkably enhance the performance.

The type of the nitrite, which is a source of rust-preventive gas for steel members, is not limited as long as it can generate rust-preventive gas by hydrolysis in the presence of water. Among them, sodium nitrite, potassium nitrite, calcium nitrite, ammonium nitrite and the like are particularly preferable in consideration of the rust prevention effect, handleability, economy and the like.

[0012] Further, a pH for imparting durability to the rust prevention effect.
As the buffer, any buffer that exerts a pH stabilizing effect in the presence system of water can be used. Among them, boric acid, phosphoric acid, phthalic acid, citric acid, succinic acid,
Tartaric acid, lactic acid and salts thereof, which may be used alone or, if necessary, in combination of two or more, are effective to further enhance the pH stabilizing effect. Particularly preferred among these are boric acid and sodium dihydrogen phosphate.

[0013] Benzotriazole and its derivatives, which are another rust-preventive component, have vaporization properties themselves, and are components that exhibit an excellent rust-preventive effect on non-ferrous metals such as Al. Of these, benzotriazole and tolyltriazole are particularly preferred, and benzotriazole is particularly preferred.

Next, the type of the resin powder to be mixed with the rust preventive component is not particularly limited. In short, the resin powder can be formed into an arbitrary shape by mixing with the rust preventive component and press-molding. Any resin powder may be used, and it is possible to use many resin powders including polyolefin resin, vinyl chloride resin, vinyl acetate resin, polyamide resin, polyester resin and the like, preferably synthetic resin powder. Although it is possible, it is particularly preferable to put it into practical use by molding it into granules or tablets, and it is particularly preferable to use a resin that can be easily joined to each other by pressure molding or the like and can maintain an arbitrary shape while leaving an appropriate gap. Powders, especially polyolefin-based resins such as polyethylene and polypropylene, vinyl chloride-based resins, vinyl acetate-based resins, and the like are preferred. Olefin-based resin powder.

The resin powder has an average particle size of 10 to 500 μm in consideration of uniform mixing with the rust preventive component, moldability, moderate interparticle gap formation for releasing rust preventive gas, and the like.
m, more preferably about 50 to 300 μm.

The preferred ratio of the above-mentioned rust-preventive component and resin powder is 1 to 40% by weight, more preferably 5 to 20% by weight, based on the total amount of the rust-preventive composition.
H buffer is 0.01 to 10% by weight, more preferably 0.1 to 10% by weight.
The content is 1 to 5% by weight, the content of benzotriazole or a derivative thereof is 1 to 40% by weight, more preferably 5 to 20% by weight, and the content of the resin powder is 10 to 90% by weight, more preferably 50 to 80% by weight. Incidentally, the vaporizable rust preventive composition of the present invention includes:
In addition to the above essential components, if necessary, a coloring agent, another antioxidant, a dehydrating agent, a dispersing agent and the like can be appropriately contained.

[0017] Thus volatile corrosion composition of the present invention obtained in the above a gap between the resin powder mutual NO ₂ ^- will be gas and benzotriazole gas is released little by little, steel members and non-ferrous metal member In any case, an excellent rust prevention effect is exhibited over a long period of time. In particular, those formed into granules or tablets, etc. do not contaminate the product to be rusted like a powdery or liquid vaporizable rust preventive, and can be stored as it is or in an appropriate breathable bag. By inserting the product into the inside of the packaging or packing bag of the product to be rust-proofed, it is possible to maintain an excellent rust-proofing effect for a long time. When the rust preventive composition of the present invention is put into practical use as a powdery mixture, if it is inserted into a breathable bag such as a nonwoven fabric so that it does not scatter, the handleability can be further improved. It is preferred.

[0018]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, but may be appropriately adjusted within a range that can conform to the purpose of the preceding and following examples. Modifications can be made and all are included in the technical scope of the present invention.

Example 1 10 parts by weight of sodium nitrite, benzotriazole 10
Parts by weight, 0.3 parts by weight of boric acid, high-density polyethylene (“HW100P” manufactured by Mitsui Petrochemical Co., Ltd., molecular weight 900) 7
After pulverizing and mixing 9.7 parts by weight using a ball mill,
Using a rotary tablet machine, 700 g of this 0.25 g was used.
It was pressed to kg to obtain a tablet type vaporizable rust inhibitor having a diameter of 10 mm and a thickness of 4.2 mm.

Example 2 The powder before pressure molding in Example 1 was used as it was, and 0.25 g of the powder was woven using a nonwoven fabric (“Unicell BT” manufactured by Teijin Limited).
-070E "), heat sealed and sealed.

Comparative Example 1 In Example 1, the blending of boric acid was omitted, and 10 parts by weight of sodium nitrite, 10 parts by weight of benzotriazole, and high-density polyethylene ("HW10" manufactured by Mitsui Petrochemical Co., Ltd.)
0P ", molecular weight 900) 80 parts by weight, except that 80 parts by weight were used, pulverized, mixed and formulated to obtain a tablet type vaporizable rust inhibitor having a diameter of 10 mm and a thickness of 4.2 mm.

Comparative Example 2 Dicyclohexylammonium nitrite (DICHAN) was used as a commercially available volatile anticorrosive compound, and 0.25 g of the compound was sealed in a nonwoven fabric in the same manner as in Example 2 above.

Comparative Example 3 Benzotriazole was used as a commercially available vaporizable rust preventive compound for nonmetals, and 0.25 g thereof was sealed in a nonwoven fabric in the same manner as in Example 2 above.

[Rust Prevention Test 1] The vaporizable rust preventives obtained in the above Examples and Comparative Examples were subjected to a short-term vaporization rust prevention test. Regarding iron, H of JIS Z 1519 4.4
The rust prevention ability was examined according to the shape test method. For non-ferrous metals (copper, aluminum, cast aluminum),
A test specimen of 40 × 60 × 2 mm was hung on a rubber stopper and sealed in a 1-liter wide-mouthed bottle together with each volatile anticorrosive,
After standing at 30 ° C. for 18 hours, the mixture was cooled to 20 ° C., and 20 ml of deionized water was poured into a jar, sealed, and then sealed at 5 ° C. ×
A heat cycle test was performed for 2 hours-50 ° C. × 3 hours-5 ° C. × 16 hours, and the rusting state was visually evaluated. Table 1 shows the results. ：: No rust was observed at all, ×: Obviously rust was observed.

[0025]

[Table 1]

[Rust Prevention Test 2] Each of the vaporizable rust preventive agents obtained in the above Examples and Comparative Examples was subjected to a long-term vaporization rust prevention test. For both ferrous and non-ferrous metals, a test piece of 40 × 60 × 2 mm was hung on a rubber stopper, and each vaporizable rust inhibitor was washed with water 20
sealed in a 1 liter jar with 1 ml at 30 ° C.
The rusting state after standing for months, April and June was visually evaluated. Table 2 shows the results. ：: No rust was observed at all, ×: Obviously rust was observed.

[0027]

[Table 2]

As is clear from Tables 1 and 2, the vaporizable rust preventives of Examples 1 and 2 satisfying the requirements of the present invention have excellent rust preventive effects not only in short-term tests but also in long-term tests. On the other hand, in Comparative Example 1 (in which no pH buffering agent was blended) and Comparative Example 3 (in which the rust inhibitor for steel was not blended), the rust inhibitory effect on iron was poor, In Comparative Example 2 (commercially available rust preventive agent), a satisfactory rust preventive effect was not obtained for both iron and non-ferrous metals in a short-term volatilizable rust preventive test.

[0029]

Industrial Applicability The present invention is constituted as described above. By using nitrite in combination with a pH buffering agent, a rust-inhibiting gas is gradually released to steel materials to provide a long-term rust-inhibiting effect. In addition to the use of benzotriazole or a derivative thereof, these compounds provide excellent rust-preventing effect even on non-ferrous metal materials. Even if it is formed into granules or tablets, or even if it remains powdered, it can be prevented from being scattered and its handleability can be improved by filling and sealing in a breathable bag such as a nonwoven fabric. The practicality as a rust agent can be significantly improved.

Claims (5)

[Claims] 1. A vaporizable rust preventive composition comprising nitrite, a pH buffer, benzotriazole or a derivative thereof, and resin powder. 2. The vaporizable rust preventive composition according to claim 1, wherein the nitrite is at least one selected from the group consisting of sodium nitrite, potassium nitrite, and calcium nitrite. 3. The vaporizable rust preventive composition according to claim 1, wherein the benzotriazole or a derivative thereof is benzotriazole and / or tolyltriazole. 4. The pH buffer according to claim 1, wherein the pH buffer is at least one selected from the group consisting of boric acid, phosphoric acid, phthalic acid, citric acid, succinic acid, tartaric acid, lactic acid and salts thereof. A vaporizable rust-preventive composition according to any of the above. 5. The vaporizable rust preventive composition according to claim 1, wherein the composition is formed into granules or tablets.