JPS6024384A - Anticorrosive having stability to hard water - Google Patents

Abstract

PURPOSE:To provide an anticorrosive having high stability to hard water and superior rust preventing power and forming hardly bubbles by using one or more kinds of reaction products each prepd. by reacting a compound having a succinic anhydride group in the molecule with a salt of alpha-amino acid. CONSTITUTION:A compound having a succinic anhydride group in the molecule is reacted with a salt of alpha-amino acid such as the Na salt of glycine at about 70-95 deg.C in water or a mixture of water with other solvent to prepare a compound (imidocarboxylate) represented by formula I or a compound (amidocarboxylate) represented by formula II. Maleopimaric acid, a styrene-maleic anhydride copolymer or the like is used as said compound having a succinic anhydride group. The desired anticorrosive having stability to hard water can be provided by using one or more kinds of compounds selected among the compounds represented by the formula I , II.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a corrosion inhibitor that is stable in hard water and contains as an active ingredient a reaction product of a compound having a succinic anhydride group and an α-amino acid salt.

BACKGROUND OF THE INVENTION Organic corrosion inhibitors have been used to prevent corrosion of metals in systems where aqueous media and interplatform surfaces come into contact.

Among inorganic corrosion inhibitors, chromic acid compounds such as dichromate have an excellent corrosion-preventing effect but are toxic, and nitrite, which is effective in closed circulating water systems, remains as it is (reduced by r1). Both are undesirable because they become nitroso compounds and are carcinogenic, and phosphates cause eutrophication of stratiform rivers.

As organic corrosion inhibitors, those having a polar functional group in the molecule that can coordinate to the metal surface are basically used, such as fatty acid salts, oxycarboxylic acid compounds, benzoates, diex/- There are drugs such as ruamine and mercaptobenzothiazole, but few of them show a satisfactory IK eating prevention effect as a single drug, and usually several drugs are used in combination. Among these, fatty acid salts have particularly excellent anti-corrosion properties, but have the drawbacks of being prone to foaming, poor hard water resistance, and precipitation of calcium soap, magnesium soap, and the like. Japanese Patent Publication No. 56-58978, same number 57-39177
As a countermeasure for these problems, the use of special acylated amino acid salts is described in the issue, and the compound of Kono L. et al. is produced by the Schotten-Bacman reaction between an acid chloride and an amino acid salt. Therefore, not only is it a big problem to remove a large amount of by-product salt (generally sodium chloride), but also special and expensive acid chlorides such as branched fatty acids must be used to prevent foaming. It has certain drawbacks.

On the other hand, compounds containing a succinic anhydride group in the molecule and an alkali or amine have an excellent antirust effect, but similarly have the drawback of insufficient hard water stability.

Purpose of the Issue In view of the above-mentioned -π bond, the purpose of the present invention is to provide a stable corrosion inhibitor for hard water.

As a result of intensive research, the present inventors have found that the reaction product of a compound with a succinic anhydride group in the molecule and an α-amino acid salt has better stability against hard water and foams less. The present invention was completed after 1 year of discovery.

When the above reaction product is represented by a general formula, only one carboxyl group of succinic acid is an amide, or an Izu circle with a 16-shape.

However, X is a molecule with a succinic anhydride group in the molecule,
Residue i excluding succinic anhydride group R1 is an alkyl group;
Y is a cation excluding amino acid residue i M1i4YH”;
142 represents positive/r-on.

It goes without saying that the reaction product includes a mixture of both.

As a compound having a succinic anhydride group in the molecule, (1
) Maleic anhydride is added by Diels, Alder or ene reaction to a compound with a double content of 11 units in the molecule, such as maleated rosin, maleopimaric acid, maleated fatty acids, maleated and maleic anhydride. Copolymers such as ethylene, propylene, n-butylene, 1-
Butylene, n-pentene, i-pentene, isoprene,
1,3-pentadiene, 2,3-dimethylbutadiene,
2.5-hepcudiene, 2-methyl-1,3-hexadiene, 1°3-octadiene, cyclohexene, styrene, vinyl acetate, acrylonitrile, vinyl chloride, acrylic acid, acrylic esters, butyl vinyl ether, 1-butyl vinyl ether Examples include copolymers of maleic anhydride and the like, but the compound is not necessarily limited to the above compound group as long as it polymerizes with maleic anhydride, and also includes polymaleic anhydride and the like.

α7-mi, /As an acid (ha, glycine, alanine, valine, leucine, isoleucine, methionine, cystine, cysteine, α-aminobutyric acid, phenylalanine, tyrosine, tryptophan, threonine, serine, glutamic acid, asparagus Fonjiang, oxyglutamic acid, γ-Methylglutamic acid, cystic acid, homocystine, lysine, ornithine, histidine, etc., and the 29-alkyl chain Q form of α-amino acids include α-methylalanine, α-methylvaline, sarcosine, etc. It will be done.

Next, bases that neutralize amino acids include alkali metal hydroxides (Na0I, KOI, etc.), alkaline earth metal hydroxides (Ca(on)2, Mg(OH)2, etc.), aluminum, etc. trivalent metal hydroxides, ammonia and ff2-converted ammonia (amines, alkanolamines, diamines, dialkanolamines, polyamines,
morpholine, etc.).

The above-mentioned compound (I) and wholesaler are prepared by combining the above-mentioned compound having a succinic anhydride group in the molecule and the α-amino acid salt in a coexisting system of water or water and a solvent other than water at temperatures ranging from about 70°C to 9
By incubating at 5°C, imidocarboxylate,
Alternatively, it can be easily produced by adding an amide carboxylic acid group.

Among the corrosion inhibitors of the present invention, 7λ imidocarboxylate and amide carboxylate derived from maleic anhydride-fonic acid polymers and copolymers of maleic anhydride and other monomers are:
6', it is noteworthy that it has a scale prevention effect and further increases reliability.

Corrosion inhibitors are mainly added to systems where aqueous bodies come into contact with metals, such as cooling system water, water pressure water for tanks, water stored at full capacity, and machining liquid for nap processing. Used as a water-soluble abrasive or mixed with known rust preventives.

Examples Eight typical corrosion inhibitors of the present invention (A-H below),
Table 1 shows the test results for two comparative samples (■ and J below).

A, reaction product of glycine sodium salt and maleopimaric acid B, reaction product C of alanine calicum salt and maleopimaric acid. Reaction product of sodium glutamic acid and maleobimaric acid. Reaction product E of leopimaric acid with the sodium salt of sarcosine, sodium glutamic acid j71. and styrene-u
iif.

Reaction product F with hydromaleic acid group polymer. 7-butyl reaction product G of glucumic acid with triethylamine nx and isonokun (isobutylene-maleic anhydride co-existence compound). Reaction product of triphenolamine salt of methynic acid and inbutyl vinyl ether-maleic anhydride copolymer VII, reaction product of glucumic acid sodium salt and maleated fatty acid, sodium salt of maleopimaric acid J, Table 1 shows the test results obtained for the calicum salt of maleated tall fatty acid.

However, the test method is as follows.

(1) Stability against hard water A test sample of 0.2% water/swamp solution (pH ~10) was prepared with 400 ppm of calcium chloride and ]O,oOo1)p
Mixed with hard water of 200 ppm, respectively.
5,000"opm solution and check for presence of precipitate.
(7b0e) Tested for 100m1 graduated cylinder with stopper)': 1 of 0
．． 2% aqueous solution (pH! J~IOK') 25ml
The foam was shaken vigorously downward for 35 people 7"L 80 times, then stood still, and the foam height was measured after 10 minutes.

(3) Rust prevention test (annealed copper plate immersion method) Add 100 ml of test water to a 100 ml wide-mouthed bottle and use treated annealed copper ik (J-K5G3141.5PCC-B, -
! / Chair 70 x 30 x 0.8 (mm) was washed with sawn paper, washed with toluene, acetone, and water, and then dried), covered and left at room temperature for 30 minutes, and then removed the sample paper. I looked into KL outside of this and found it to be 1.

From the above explanation and examples, it can be seen that Raikou E! 1) The nail bite prevention agent has good stability in hard water, has little foaming,
It can be seen that it has excellent anti-rust properties.

In addition, the N4 anti-corrosion agent of Kibatso is an amino acid compound, has low resistance to Omachi, and can be used as a low-pollution IIF anti-corrosion pre-preventive agent. It is something that should be done.

Table 1

Claims (1)

[Claims] Succinic anhydride group in the molecule? A compound with αa (in the formula,
or the residue of a molecule having a succinic anhydride group in the molecule, excluding the succinic anhydride group, R1 is an alkyl group, Y is an amino acid residue, Ml is a cation excluding H, MZ is a cation . ) A corrosion inhibitor stable in hard water, characterized in that it contains one or more compounds selected from the group consisting of: