CZ287586B6 - Rust preventers and use thereof - Google Patents

Abstract

In the present invention there are disclosed rust preventers containing a polyester salt of alkyl succinic acid or alkenyl succinic acid that is free of amine groups and whose alkyl or alkenyl substituents contain 8 to 15 carbon atoms. The invented rust preventers are usable as corrosion inhibitors, further as a component of coolants and lubricants, optionally auxiliary preparations for working metals that are not harmful to health.

Description

Anti-corrosion agents and their use

Technical field

The invention relates to anti-corrosion agents for use in many metal processing fields where it is concerned to protect used metal parts from rust. It further relates to their use for the production of cooling and lubricating fluids.

BACKGROUND OF THE INVENTION

Conventional anticorrosive agents include components such as petroleum fraction sulfonates, alkylsulfonamidocarboxylic acid salts, and amine salts of alkyl succinic acid or alkenylsuccinic acid semi-ester.

DE-A-26 40 854 discloses lubricant formulations having anticorrosive properties based on the amine salts of the alkyl succinic or alkenylsuccinic acid semi-ester partial ester.

EP-A-336 467 discloses anti-corrosion agents based on alkylarylsulfonic acids, alkanolamine and a semi-ester of alkyl succinic or alkenylsuccinic acid.

It has been shown that sulfur-containing compounds such as alkylarylsulfonic acids, petroleum fraction sulfonates or alkylsulfonamidocarboxylic acid salts can be readily degraded by microorganisms such as sulfur reducing bacteria. Nitrogen-containing corrosion protection agents, in particular secondary amines, can, for example, be chemically converted into health-threatening nitrosamines.

It is precisely with regard to the use of non-corrosive anti-corrosion agents that it is important to prepare compositions which, in their use, avoid health hazards and which do not contain nitrogen, in particular which do not contain amines.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide amine-free corrosion-preventing agents for use which prevent the formation of health-threatening substances such as nitrosamines.

It has surprisingly been found that salts, in particular alkali metal salts and alkaline earth metal salts of alkyl succinic or alkenylsuccinic acid semi-esters can be used as anti-corrosion agents and thus the risk of nitrosamines can be avoided.

The present invention provides anti-corrosion agents comprising salts of an alkylsuccinic or alkenylsuccinic acid semi-ester of which the alkyl or alkenyl substituents contain 8 to 15 carbon atoms, preferably 9 to 15 carbon atoms, and which do not contain an amino group.

Salts which do not contain an amino group, in particular alkali metal salts and alkaline earth metal salts, are obtained by esterification of an alkyl succinic or alkenyl succinic anhydride with an alcohol, preferably in equimolar amounts, optionally using a catalyst additive such as an alcoholate solution at temperatures up to the boiling point , preferably 20 ° C to boiling point, particularly preferably 40 to 80 ° C. The reaction is preferably carried out under a nitrogen atmosphere. A preferred embodiment is stirring the solution after addition of the alcohol at a temperature up to the boiling point of the solution, preferably 60 ° C to the boiling point of the solution. The semi-products obtained are then

They are treated by treatment with dilute caustic up to a pH of greater than 7, preferably up to a pH in the region of about 9.

The semi-ester is derived from an alkylsuccinic or alkenylsuccinic acid in which the alkyl or alkenyl substituent contains 8 to 15 carbon atoms, preferably 9 to 15 carbon atoms. Examples of such succinic acids are octenylsuccinic or dodecenylsuccinic acid. The substituent groups may also be polyolefinic groups such as a tripropenyl, tetrapropenyl or pentapropenyl radical.

The alcohol used to form the semi-ester preferably has 1 to 15 carbon atoms and preferably contains an alkyl alcohol (alkanol) such as methanol, ethanol, propanol or butanol.

The lyes to which the substituted succinic acid semi-esters react are preferably aqueous hydroxide solutions such as sodium hydroxide or potassium hydroxide. Aqueous solutions of polyvalent metal hydroxides such as alkaline earth metal hydroxides are also suitable.

The aqueous solutions of the salts of alkylsuccinic or alkenylsuccinic acid which do not contain an amine group can be used directly as anti-corrosion agents without further purification.

Salts which do not contain an amino group are useful as aqueous anti-corrosion agents, and are preferably used in a concentration of 0.5 to 65% by weight, particularly preferably 1 to 10% by weight, based on the aqueous solution. The pH of the aqueous anti-corrosion agents is higher than pH 7, preferably having a pH of about 9.

Salts which do not contain an amino group can also be used as anti-corrosion agents in admixture with other compounds.

Such anti-corrosion agents consist, for example, of:

40 to 80% by weight 30 to 1% by weight salts of alkyl succinic or alkenylsuccinic acid semi-ester of oxethylates of the formula R * -O- (CH ₂ CH ₂ O) _n H, wherein R ¹ is an alkyl having a carbon number of C ₁₀ -C ₂₂ , alkenyl having a carbon number of C ₁₀ -C 22 or C ₁₀ -C 22 alkaryl and 1 to 10, preferably 1 to 5 30 to 1% by weight fatty acids of formula R ² -COOH, wherein R ² is an alkyl having a carbon number of C10-C22 or an alkenyl having a carbon number of C10-C30 30 to 0% by weight ether carboxylic acids of the formula R ³ -O- (CH 2 CH ² O) _n -CH ₂ COOH, wherein R ³ is an alkyl having a carbon number of C10-C22, alkenyl having a carbon number of C10-C22 or an alkaryl and is 1 to 10, preferably 1 to 5.

Such anticorrosive agents are characterized by perfect "solubility" in combination with water. When mixed with water, they form finely dispersed emulsions, which may be clear (opaque), opal or milky.

Mixtures of the aforementioned non-amine salts of alkyl succinic or alkenyl succinic polyesters with oxethylates, fatty acids and optionally ether carboxylic acids are preferably used with mineral oils in an amount of up to 70% by weight of the mineral oil based on the total weight and exhibit good anti-corrosion properties.

Suitable mineral oils are mineral oils which consist of paraffin, naphthenes as well as partially aromatics and usually have a viscosity of 25 to 30 mm ² / s measured at 20 ° C.

The foregoing mixtures of amine-free salts, oxethylates, fatty acids and optionally ether carboxylic acids exhibit an emulsifying and corrosion-inhibiting effect in aqueous mineral oil processing aids.

The term metal processing aids also includes cooling and lubricating agents.

Aqueous solutions of salts not containing an amine group having a concentration of 0.1 to 10% by weight, preferably 1 to 5% by weight, of polyesters of alkyl succinic or alkenylsuccinic acid with oxethylates, fatty acids and optionally ether carboxylic acids and mineral oils are preferably used as anticorrosive agents, in particular with regard to good stability in hard water environments, they show good results.

The test results below show that the amine-free salts of the invention are effective as anti-corrosion agents.

Table 1 shows the corrosion inhibiting effects of an aqueous alkaline solution of amine-free salts.

Table 2 shows the corrosion inhibiting effect of the composition.

In the tables, EO denotes ethylene oxide and ° dH denotes the degrees of German hardness.

The corrosion inhibiting effect was determined based on the Herbert test (DL 51360/1) and the filter paper test (DIN 51360/2).

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Sodium tripropenylsuccinic acid monomethyl ester

224.0 g (1.0 mol) of tripropenylsuccinic anhydride and 0.5 g (30% by weight) of sodium methanolate solution are used as feed. At a temperature of 45-55 ° C, 35.2 g (1.1 mol) of methanol (technical) are added dropwise over 15 minutes under a nitrogen atmosphere. It is then stirred for 5 hours at 65 ° C. At a pressure of about 40 mm Hg, excess methanol (distillate: 3.3 g) is distilled off at an internal temperature of up to 100 ° C. 250.0 g of an orange-colored product are obtained, which is converted to the sodium salt by addition of a 33% aqueous sodium hydroxide solution (pH ca. 9).

Example 2

Sodium triphenylsuccinic acid monoisobutyl ester

224.0 g (1.0 mol) of tripropenylsuccinic anhydride are introduced and preheated to 80 ° C. At 80 ° C, 74.1 g (1.0 mol) of isobutanol are added dropwise over 30 minutes under a nitrogen atmosphere. It is then stirred for 5 hours at 105 ° C. 297.4 g of an orange-colored clear liquid are obtained, which is converted to the sodium salt by addition of a 33% aqueous sodium hydroxide solution (pH ca. 9).

Example 3

Tetrapropenylsuccinic acid monoisopropyl ester sodium

266.0 g (1.0 mol) of tetrapropenylsuccinic anhydride are introduced and preheated to 80 ° C. At 80 ° C, 60.1 g (1.0 mol) of isopropanol are added dropwise over 30 minutes under a nitrogen atmosphere. It is then stirred for 12 hours at 80 ° C. 299.2 g clear

The oil was converted to the sodium salt by the addition of 33% aqueous sodium hydroxide solution (pH ca. 9).

Example 4

Tetrapropenylsuccinic acid monoisobutyl ester sodium salt

266.0 g (1.0 mol) of tetrapropenylsuccinic anhydride are introduced and preheated to 80 ° C. At 80 ° C, 74.1 g (1.0 mol) of isobutanol are added dropwise over 30 minutes under a nitrogen atmosphere. It is then stirred for 5 hours at 105 ° C. 338.4 g of a clear oily substance are obtained, which is converted to the sodium salt by addition of a 33% aqueous NaOH solution (pH ca. 9).

Example 5

Pentapropenylsuccinic acid monomethyl ester sodium salt

348.0 g (1.0 mol) of pentapropenylsuccinic anhydride and 0.5 g (30% by weight) of sodium methoxide solution are introduced as catalyst. At 50 ° C, 26.9 g (0.84 mol) of methanol (technical) are added dropwise (slightly exothermic reaction) under nitrogen atmosphere over 30 minutes. Subsequently, it is stirred for 4 hours at 105 ° C. 372.4 g of a brown clear oily liquid are obtained, which is converted to the sodium salt by adding 33% aqueous sodium hydroxide solution (pH ca. 9).

Example 6

Pentapropenylsuccinic acid monoisopropyl ester sodium salt

348.0 g (1.0 mol) of pentapropenylsuccinic anhydride are introduced. At 80 ° C, 50.5 g (0.84 mol) of isopropanol are added dropwise over 40 minutes under a nitrogen atmosphere. It is then stirred for 12 hours at 80 ° C. 394.6 g of a brown clear oil is obtained, which is converted to the sodium salt by addition of a 33% aqueous NaOH solution (pH ca. 9).

Example 7

Cn / u-alkenylsuccinic acid monomethyl ester sodium salt

Initially introduce 138.0 g (0.5 mol) of acid anhydride Cl2 / i -alkenyljantarové ₄ and 0.5 g (30 wt.%) Of sodium methoxide solution and heated to 50 ° C. At 50 ° C, 16.1 g (0.5 mol) of methanol are added dropwise over 15 minutes under a nitrogen atmosphere. It is then stirred for 5 hours at 65 ° C. 148.2 g of a yellowish clear liquid are obtained, which is converted to the sodium salt by addition of a 33% aqueous NaOH solution (pH ca. 9).

Example 8

Sodium salt of monoisopropenyl Cn / u-alkenylsuccinate

414.0 g (1.5 mol) of C 12 H ₁₄ -alkenylsuccinic anhydride are introduced and heated to 80 ° C. At 80 ° C, 90.2 g (1.5 mol) of isopropanol are added dropwise over 30 minutes under a nitrogen atmosphere. It is then stirred for 12 hours at 80 ° C. 503 g of a yellow clear product are obtained, which is converted to the sodium salt by addition of a 33% aqueous NaOH solution (pH ca. 9).

-4GB 287586 B6

Table 1

Example 1 2 3 4 Appearance / 20 ° C red red red red Brown Brown Brown Brown clear clear clear clear liquid liquid liquid liquid pH value of 1 wt.%, solution in dest. H ₂ O 9.0 9.1 9.1 8.9 Emulsion stability 3% by weight, 0 ° dH instant solution clear clear clear clear 0 ° dH after 24 h opal opal opal opal 20 ° dH instantaneous strongly strongly strongly strongly opal opal opal opal 20 ° dH for 24 h dairy dairy dairy dairy Protection against co- none none none none rozi podle rust, rust, rust, rust, DIN 51360/1 none none none none 2 wt. black black black black spots spots spots spots DIN 51360/2 none none none none 2 wt. rust rust rust rust Example 5 6 7 8 Appearance / 20 ° C red red yellow- yellow- Brown Brown Brown Brown clear clear paste paste liquid liquid pH value of 1 wt.%, solution in dest. H ₂ O 9.0 9.0 9.1 8.9 Emulsion stability 3% by weight, 0 ° dH instant solution clear clear clear clear 0 ° dH after 24 h opal opal clear clear 20 ° dH instantaneous strongly strongly opal opal opal opal 20 ° dH for 24 h dairy dairy opal opal Protection against co- none none none none rozi podle rust, rust, rust, rust, DIN 51360/1 none none none none 2 wt. black black black black spots spots spots spots DIN 51360/2 none none none none 2 wt. rust rust rust rust

-5GB 287586 B6

Table 2

Example 1 2 3 4 Emulgovaný končen- Brown, Brown, Brown, Brown, % 30 wt. according to clear clear clear clear %, 5 wt. % oleyl alcohol + 2 moles EO, 5 wt. % talic acid, 60 wt. oil, mineral, oil liquid liquid liquid liquid Emulsifiability spontaneous spontaneous spontaneous spontaneous Emulsion stability 3 wt. 0 ° dH solution dairy, dairy, dairy, dairy, opalescent opalescent opalescent opalescent emulsion emulsion emulsion emulsion 0 ° dH after 24 h unchanged unchanged unchanged unchanged 20 ° dH instantaneous dairy, dairy, dairy, dairy, opalescent opalescent opalescent opalescent emulsion emulsion emulsion emulsion 20 ° dH for 24 h unchanged unchanged unchanged unchanged Protection against co- none none none none rozi podle rust, rust, rust, rust, DIN 51360 / 1.3% none none none none black black black black spots spots spots spots DIN 51360 / 2.3% none none none none rust rust rust rust Example 5 6 7 8 Emulgovaný končen- Brown, Brown, yellow- yellow- % 30 wt. according to clear clear Brown, Brown, %, 5 wt. liquid liquid clear clear % oleyl alcohol + 2 moles EO, 5 wt. % talic acid, 60 wt. oil, mineral, oil liquid liquid Emulsifiability spontaneous spontaneous through the gel phase through the gel phase Emulsion stability 3 wt. 0 ° dH solution dairy, dairy, dairy, dairy, opalescent opalescent opalescent opalescent emulsion emulsion emulsion emulsion 0 ° dH after 24 h unchanged unchanged unchanged unchanged 20 ° dH instantaneous dairy, dairy, dairy, dairy, opalescent opalescent opalescent opalescent emulsion emulsion emulsion emulsion 20 ° dH for 24 h unchanged unchanged unchanged unchanged

-6GB 287586 B6

Table 2 (continued)

Example 5 6 7 8 Protection against co- none none none none rozi podle rust, rust, rust, rust, DIN 51360 / 1.3% none none none none black black black black spots spots spots spots DIN 51360 / 2.3% none none none none rust rust rust rust

Industrial applicability

The anticorrosion compositions of the present invention based on salts of the alkyl ester of alkali succinic acid or alkenylsuccinic acid which do not contain an amine group and can be used as corrosion inhibitors in aqueous metal working aids, as cooling and lubricating liquids, while showing good stability and no health hazard.

Claims (9)

CLAIMS 1. Corrosion agents, characterized in that they contain salts of the alkyl ester of alkyl succinic acid or alkenylsuccinic acid which do not contain an amino group whose alkyl or alkenyl substituents contain 8 to 15 carbon atoms, preferably 9 to 15 carbon atoms. The composition of claim 1, wherein the salt is an alkali metal or alkaline earth metal salt. Composition according to claim 1 or 2, characterized in that the semi-ester is a semi-ester of an alkylsuccinic or alkenylsuccinic acid and an alcohol having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. Composition according to one of Claims 1 to 3, characterized in that the succinic acid semi-ester consists of a polyolefinjantaric acid semi-ester, preferably of tri-, tetra- or pentapropenyl 1, antaric acid. Composition according to one of Claims 1 to 4, characterized in that it contains 0.5 to 65% by weight, preferably 1 to 10% by weight, of the salt not containing the amino group of the alkyl or alkenylsuccinic acid semi-ester, based on the aqueous solution. 6. A composition according to claim 1 comprising 40 to 80% by weight alkyl- or alkenylsuccinic acid semi-ester salts as defined in claim 1 30 to 1% by weight oxethylate of formula R'-O- (CH 2 CH 2 O) _n H, wherein R ¹ is an alkyl having a carbon number of C ₁₀ -C ₂₂ , an alkenyl having a carbon number of C ₁₀ -C ₂₂ or an alkaryl having a carbon number of C ₁₀ -C _{22 n} is 1 to 10; preferably 1 to 5 30 to 1% by weight a fatty acid of the formula R ² -COOH wherein R ² is alkyl having a carbon number of C ₀ -C ₂ 2 or alkenyl group having a carbon number of C10-C30 30 to 0% by weight of an ether carboxylic acid of the formula R ³ -O- (CH 2 CH 2 O) n -CH 2 -COOH, wherein R ³ is an alkyl of C 10 -C 22, alkenyl of C 10 -C ₂₂ or alkaryl and n is 1 to 10 , preferably 1 to 5. Composition according to claim 6, characterized in that it contains up to 70% by weight of mineral oil, based on the total weight of the composition. Composition according to claim 6 or 7, characterized in that it contains 0.1 to 10% by weight, preferably 1 to 5% by weight, of a mixture of an amine-free oxethylate salt, fatty acids and optionally ether carboxylic acid and a mineral oil based on aqueous solution. Use of the compositions according to claims 1 to 8 for the production of cooling lubricants or metal processing aids.