JP2000328272A - Anticorrosive composition for aluminum material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the composition to exhibit excellent anticorrosive effect over a long period even in the case of being exposed to severe corrosive environment such as a salt damage area by allowing it to contain acidic phosphoric esters as effective components. SOLUTION: This compsn. contains at least one of acidic phosphoric esters shown by formula I and II. In both formulae, R1, R2 and R3 each denote a substitutional group selected from the groups consisting of a 20 to 40C branched or nonbranched alkyl group, an alkenyl group, an alkinyl and an aryl group, in the case of being an alkyl group, an alkenyl group or an alkinyl group, they may be the one in which a polar substitutional group such as a nitro group, a hydroxy group and a carboxyl group has been substituted, and in the case of being an aryl group, it may be the one in which a lower alkyl group, a lower alkenyl group or a polar substitutional group such as a hydroxy group, a nitro group and a carboxyl group has been substituted. The content of the acidic phosphoric esters in the compsn. is optional, but, particularly suitably, it is controlled to 0.5 to 3 pts.wt. to 100 pts.wt. of the compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an anticorrosive composition for aluminum materials. More specifically, aluminum materials for various aluminum facilities, structures, parts, products, etc., especially aluminum power distribution lines, steel core aluminum stranded wires, aluminum covered steel stranded wires,
Aluminum wire that constitutes twisted wire such as optical fiber composite overhead ground wire,
The present invention relates to an anticorrosive composition for aluminum materials suitable for aluminum-coated steel wires, aluminum pipes and the like.

[0002]

2. Description of the Related Art Among various applications in which aluminum materials are used, fields requiring high corrosion resistance include the above-mentioned various aluminum electric wires and optical fiber composite ground wires. Generally, it is said that aluminum corrosion is small in a neutral region of pH 4 to 8, since a hydrated oxide (Al 2 O 3 .3H 2 O) is densely covered with a hydrated oxide and passivated. However, especially in the so-called salt-damaged areas near the coast, even in the neutral region, the aluminum material used for aluminum electric wires and optical fiber overhead ground wires causes local corrosion (pitting corrosion) and mechanical strength. Problems, such as lowering of the wiring, and further, disconnection.

[0003] As a countermeasure, a method of applying or filling an anticorrosive grease to an aluminum material is usually employed. However, since anti-corrosion grease has poor heat resistance, it has problems such as falling off due to long-term use or squeezing out due to the compressive force between stranded wires and reducing the anti-corrosion effect. I was

Further, an anticorrosion film is formed on an aluminum surface by using a specific anticorrosion agent composition other than the anticorrosion grease,
Methods of controlling corrosion have also been studied as one of the measures. Anticorrosive compositions which can be used for this purpose include those containing various alkyl phosphate compounds as active ingredients (for example, JP-A-49-96941, JP-A-53-14623).
No. 7, JP-A-5-156473, etc.), but it cannot be said that sufficient effects are still obtained in severe environments such as salt-affected areas.

[0005]

In recent years, there has been an active movement to use aluminum as a power distribution material even in salt-affected areas, so that corrosion resistance required for aluminum electric wires and optical fiber overhead ground wires has been required. The performance is becoming increasingly severe, and there is a strong demand for anticorrosive agents that provide higher corrosion resistance and a longer period of continuous use as compared with conventionally used anticorrosive greases and anticorrosive compositions.

[0006] An object of the present invention is to solve the above-mentioned problems, and by applying it to an aluminum material such as an aluminum wire, an aluminum-coated steel wire or an aluminum tube, a strong anticorrosive film is formed on the surface of the aluminum material, thereby preventing salt damage. An object of the present invention is to provide an anticorrosive composition which exhibits an excellent anticorrosion effect for a long period even when exposed to a severe corrosive environment such as an area.

[0007]

As a result of various studies conducted by the present inventor to solve the above-mentioned problems, it has been found that a composition containing a specific acidic phosphate as an active ingredient can cause corrosion of aluminum material for a long period of time. The inventor has found that it can be prevented with excellent performance, and reached the present invention.

That is, the present invention provides a compound represented by the general formula (1):

Embedded image And general formula (2)

Embedded image (Wherein R1, R2, and R3 are substituents selected from the group consisting of branched or unbranched alkyl, alkenyl, alkynyl, and aryl groups containing 20 to 40 carbon atoms, and include alkyl groups, alkenyl groups Or, in the case of an alkynyl group, a nitro group, a hydroxy group, those substituted with a polar substituent such as a carboxyl group, and in the case of an aryl group, a lower alkyl group, a lower alkenyl group, or a hydroxy group,
It may be substituted with a polar substituent such as a nitro group or a carboxyl group. The gist of the present invention is an anticorrosive composition for aluminum materials containing at least one of the acidic phosphates represented by the formula (1) as an active ingredient.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The acid phosphates used in the anticorrosive composition of the present invention are a generic term for partial ester compounds of phosphoric acid, and are acid phosphates (acid p).
Also referred to as a “host”. In general, although there is some variation in composition, commercially available mixtures of mono- and diesters are easily available, and even if they contain trace amounts of impurities such as metaphosphoric acid, pyrophosphoric acid, and phosphoric acid, there is no problem in use. Absent.

The type of R1, R2 and R3 in the above general formula is a substituent selected from the group consisting of branched or unbranched alkyl, alkenyl, alkynyl and aryl groups containing 20 to 40 carbon atoms. A nitro, hydroxy, or carboxyl group substituted for an alkyl, alkenyl, or alkynyl group; a lower alkyl, lower alkenyl, hydroxy, nitro, or carboxyl group for an aryl group May be substituted. From the viewpoints of availability of raw materials and anticorrosion effect, those having an unbranched alkyl or alkenyl group containing 21 to 30 carbon atoms are more preferable.

Specific examples of acidic phosphates include n
-Eicosyl acid phosphate, di-n-eicosyl acid phosphate, n-heneicosyl acid phosphate, di-n-heneicosyl acid phosphate, n-tricosyl acid phosphate, di-n-tricosyl acid phosphate, n -Tetracosyl acid phosphate, di-n-tetracosyl acid phosphate, n-hexacosyl acid phosphate, di-n-hexacosyl acid phosphate, n-heptacosyl acid phosphate, di-n-heptacosyl Acid phosphate, n-octactocosyl acid phosphate, di-n-octacosyl acid phosphate, and the like, but are not limited thereto, and any acid phosphates represented by the above general formula can be used. Can be used. These acid phosphates are commercially available products, those obtained by reacting the corresponding alcohols or phenols with diphosphorus pentoxide, and the reaction of the corresponding alcohols or phenols with the phosphorus oxyhalide, Then, it can be obtained by any method such as a product obtained by hydrolysis or a product obtained by reacting triphosphate with phosphorus oxyhalide to form a pyrophosphate ester and then hydrolyzing. .

The organic solvent which can be used in the anticorrosive composition of the present invention is not particularly limited as long as it is a good solvent of the above-mentioned acidic phosphates. Examples of such a solvent include saturated linear or branched aliphatic alcohols having 1 to 10 carbon atoms such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, and 1,1. , 1-trichloroethane,
Chlorinated hydrocarbons such as methylene chloride, saturated linear or branched hydrocarbons having 5 to 14 carbon atoms such as n-decane, propylene glycol monomethyl ether,
Various organic solvents such as propylene glycol solvents such as propylene glycol monoethyl ether can be exemplified.

Although the content of the acid phosphates in the anticorrosive composition of the present invention is optional, it is more preferable that the content of the acid phosphates is 0.1 to 10 parts by weight per 100 parts by weight of the anticorrosive composition. , 0.5 to 3 parts by weight. When the compounding ratio is 0.1 part by weight or more, the anticorrosion effect of the acid phosphates becomes clearer. However, even if it exceeds 10 parts by weight, the formed anticorrosion film is not further strengthened, and the anticorrosion effect is saturated. Reach

These mixing ratios are the mixing ratios when used as an anticorrosive. When the solubility of each component in an organic solvent is high, a solid or high-concentration solution is prepared during transportation.
It does not prevent dissolving or diluting to a predetermined concentration at the time of use. Further, the anticorrosive composition of the present invention and another anticorrosive may be mixed or used in combination.

The method of applying the anticorrosive composition of the present invention to an aluminum material includes a method of spraying or flowing down the anticorrosive composition on the aluminum material, a method of dipping the aluminum material in the anticorrosive composition, and a method of applying the anticorrosive composition. A suitable method can be selected, such as a method in which a felt material or a sponge material impregnated with a material is brought into contact with an aluminum material.

[0016]

The present invention will be specifically described below with reference to examples and comparative examples. Note that the present invention is not limited to these examples.

(Preparation of anticorrosion film forming test piece) As an aluminum test piece used in the anticorrosion performance test, an aluminum wire actually used for an aluminum distribution line was used. The aluminum wire was cut so as to have a length of 20 cm. First, as a pretreatment, methylene chloride was washed to remove the drawn wire oil, and then dried. The pretreated aluminum wire was immersed in the anticorrosive composition for 2 seconds at room temperature, and then dried at room temperature for 24 hours to obtain a test piece for forming an anticorrosion film.

(Anti-corrosion performance test) The anti-corrosion film-forming test piece obtained above was immersed in a 5% by weight saline solution at 75 ° C. for one day so as to be 80% of the entire length, and then it was to be 50% of the entire length. Soak for 6 days. The immersion method was repeated five times and then taken out. First, the condition of the surface of the aluminum test piece was visually observed, and the occurrence of corrosion products and pitting corrosion was determined. Depending on the degree of the corrosion product and pitting corrosion occurrence status judgment result,
It is indicated by the following symbols. Next, the test piece, for which the determination of the state of occurrence of corrosion products and pitting corrosion has been completed, is immersed in boiling water containing 5% by weight of phosphoric acid and 3% by weight of chromic acid for 3 minutes to remove the corrosion products. After rinsing, drying and weighing, the weight loss due to corrosion was determined. Table 1 shows the results obtained.

(Determination of the state of occurrence of corrosion products) ：: No discoloration and no generation of corrosion products are observed. Δ: Partial discoloration and generation of corrosion products are observed. Product generation is observed

(Judgment of Pitting Corrosion Occurrence) ：: No pitting is observed. Δ: One to several pits are observed.

Examples 1-4, Comparative Examples 1-4 Anticorrosive compositions containing the components shown in Table 1 were prepared.
The above anticorrosion performance test was performed. Table 2 shows the results of the anticorrosion performance test.

[0022]

[Table 1]

[0023]

[Table 2]

As is clear from Table 2, the anticorrosive composition of the present invention using an acidic phosphate having 20 or more carbon atoms is more effective than the comparative example using an acidic phosphate having less than 20 carbon atoms. It can be seen that is significantly improved. In particular, n-tetracosyl acid phosphate and di-
The anticorrosive composition containing n-tetracosyl acid phosphate has a remarkable reduction in corrosion weight loss, and the occurrence of corrosion products and pitting corrosion is well suppressed. It can be seen that the components work effectively and significantly improve the anticorrosion performance.

[0025]

By treating an aluminum material such as an aluminum wire, an aluminum-coated steel wire or an aluminum pipe with the anticorrosive composition for an aluminum material of the present invention, a strong anticorrosion film is formed on the surface of the aluminum material. By forming it, the corrosion resistance of the aluminum material could be significantly improved over a long period of time.

Claims (1)

[Claims] 1. A compound of the general formula (1) And the general formula (2) (Wherein R1, R2, and R3 are substituents selected from the group consisting of branched or unbranched alkyl, alkenyl, alkynyl, and aryl groups containing 20 to 40 carbon atoms, and include alkyl groups, alkenyl groups Alternatively, in the case of an alkynyl group, a nitro group, a hydroxy group or a carboxyl group may be substituted, and in the case of an aryl group, a lower alkyl group, a lower alkenyl group, a hydroxy group, a nitro group or a carboxyl group may be substituted. An anticorrosive composition for an aluminum material, comprising at least one acidic phosphoric acid ester represented by the formula: