EP3449039A1

EP3449039A1 - Rust dissolver for dissolving corrosion layers

Info

Publication number: EP3449039A1
Application number: EP17723932.4A
Authority: EP
Inventors: Thomas Isleib; Hans Götz; René Dieter WEBER
Original assignee: Kerona GmbH
Current assignee: Kerona GmbH
Priority date: 2016-04-26
Filing date: 2017-04-26
Publication date: 2019-03-06
Also published as: WO2017186791A1; DE102016107681A1

Abstract

The invention relates to a rust dissolver (50) for dissolving a corroded mechanical connection of metallic surfaces. The rust dissolver (50) comprises at least one solvent (51), at least one thickener (54), at least one complexing agent (53) for metal ions and at least a non-ionic surfactant (52). The invention further relates to a method for dissolving a corroded mechanical connection of metallic surfaces using the rust dissolver (50).

Description

Rust remover for dissolving corrosion layers

Description

The invention relates to a rust remover for releasing a corroded mechanical connection of metallic surfaces and to a method for using the rust remover.

Metals have the property to corrode at their surfaces, ie the metals enter into a chemical compound with oxygen from the environment and form an oxide layer. For a number of metals such as zinc, copper, chromium, etc., this is not a big problem because the oxide layer formed in this way shields the surface from the surrounding atmospheric oxygen and prevents further corrosion. As a rule, corrosion of such metals comes to a standstill.

Corrosion is the reaction of a metallic material with its surroundings, which causes a measurable change in the material, in particular a formation of a porous oxide layer, and can lead to an impairment of the function of a mechanical component or an entire system. This is particularly problematic if the formed porous oxide layer does not inhibit further corrosion and the decomposition of the metallic material continues.

It may happen that an oxide layer changes the material properties such that further processing is difficult and therefore the oxide layer must be removed again, e.g. during electrical contacting or soldering with aluminum.

With rust is commonly called the corrosion of metal objects, eg. As red rust (iron), white rust (zinc, aluminum), by oxidation with oxygen in the presence of water.

The problem is particularly serious in many mechanical connections with metallic, especially iron-containing, fasteners, especially in screw, for example, screws and nuts. The oxidation causes an increase in mass and volume and forms a loose structure of lesser strength. If such screw joints are corroded, they are roughened on their abutting surfaces and literally baked together, if necessary, or only with great effort solvable. With regard to other materials, rust does not prevent further oxidation, but continues and therefore causes long-term damage. To treat such oxidized surfaces, several methods have been established.

Thus, the oxide layer can be mechanically removed by brushing or grinding. This requires access to the corroded point and the further process is expensive.

Another method of treating an oxide layer, especially on rusty surfaces, is the application of liquid actives which are suitably applied and act on the corroded site.

Here, a distinction is made roughly between rust transducers, rust pickling and rust erosion.

Rust converters are liquid mixtures that convert the rust into stable, non-porous iron (III) oxide compounds through a chemical conversion process. This reduces moisture absorption and suppresses further corrosion. Rust converters can still be thickened with suitable agents due to the usually aqueous composition above the given viscosity in order to increase the viscosity, so that the rust converter preferably does not flow away or drips, but remains long on the object at the problem zone and acts there in order to achieve the desired the desired change usually required to have a longer time available. In the case of rust conversion, the material thus treated remains on the corresponding object. However, this contributes to a further thickness structure, so that the problem of a tight threaded connection is further aggravated.

Rust pickles are used to dissolve the rust and expose the bare metal surface. In the basic structure, these usually consist of organic and inorganic acids, which however also attack the metallic, in particular iron-containing, base material. For the general application on Rusty screw connections pickling are also less suitable because necessary creep properties are not present in order to penetrate into the smallest openings or in the smallest spaces can.

For seized screw connections rust removers are therefore most suitable. Commercially available rust removers are produced on the basis of creep oils. These oils are so called because they are very low viscosity and can penetrate by capillary action against gravity in the finest openings or cracks. They can infiltrate moisture, whereby existing dirt or oxide particles are dispersed in the liquid. Frequently the common rust removers contain additives such as graphite dust or M0S2 in order to increase the lubricating effect of the oil and to guarantee it even under high pressure. In rust removers according to the prior art, however, an improvement in the actual disengagement of a screw connection is achieved due to the composition, but it is only the friction value is reduced when a compound has already been solved. That First, the force must be applied to release the connection and only after a first minimal release of the rust remover can act according to the prior art and support further detachment.

Another example of prior art rust remover is described in US 2005 027 26 14 A1 and discloses a surface treatment for metals having a composition of an acid rust inhibitor, a neutral one

Alkaline earth metal sulfonate as a first corrosion inhibitor component, a second phosphorus-based corrosion inhibitor component, and a creepable mineral oil as a solvent.

The fact that the commercially available rust removers are low viscous due to the mineral oil used, they have a desired creep to penetrate in use in practice in the smallest gaps. The disadvantage of this is that such a rust remover just by this property after application also runs away quickly or drips off. As a result, the rust remover in the problem zone is no longer sufficiently available and can no longer act there or only insufficiently. The effluent or dripping liquid contaminates other areas and can ultimately endanger the health or pose a risk of accident upon contact with the user. An overhead application is therefore difficult to perform. An increase in the viscosity of such a non-aqueous composition with the aid of thickeners, for example with long-chain polymers (inter alia polyolefins (PAO)) leads to a simultaneous reduction of creep. This means that the product can no longer penetrate into the smallest gaps and is thus not effective in the critical areas. The object of the invention is therefore to provide an improved rust remover for releasing corroded mechanical connections of metallic surfaces and a method for using such a rust remover.

The problem underlying the invention is solved by the features of the independent claims. Embodiments of the invention are indicated in the dependent claims.

According to the invention, a rust remover is provided for releasing a corroded mechanical connection of metallic surfaces. The rust remover comprises at least one solvent, at least one thickener, at least one nonionic surfactant and at least one complexing agent for metal ions, for example iron. Embodiments may have the advantage of providing a rust solvent free of mineral oil, with which metal oxides, in particular iron oxide (rust) or aluminum oxide, are converted by chemical reaction into corresponding metal complexes. The metal oxide or the metal complexes thus formed are thereby released from the substrate and the corrosion layer comprising the oxides is at least partially removed. In particular, embodiments may provide an acid-free rust remover. The corroded mechanical connection of metallic surfaces may, for example, be a positive and / or non-positive connection between at least two connecting elements, each of which has a metallic surface. According to embodiments, the two metallic surfaces of the two connecting elements abut each other. According to embodiments, the corroded mechanical connection comprises at least one corrosion or oxide layer between the metallic surfaces of the connection. According to embodiments, the corrosion layer, in particular by increasing the static friction, increases the force necessary for releasing the positive and / or non-positive connection.

If the rust remover is used, for example, to loosen a screw connection, the release of the firmly corroded surface layers is actively supported. The creeping ability of the rust remover is ensured by means of the non-ionic surfactant or soap contained, which also lubricate the primary dissolved connecting elements in the further separation and thus further support the Lösepro- process.

According to embodiments, the rust remover is acid and / or anhydrous. Embodiments may have the advantage that the rust remover does not attack the metallic surfaces of the mechanical connection and thus they are protected. In contrast, in the case of an acidic and in particular an acid and water-containing rust remover, there is the danger that acid will attack the metallic surfaces. Acids act as proton donors whose reactant in aqueous solution is essentially the water and form the oxonium ion, ie H3O ⁺ ions. An acid can therefore be considered as a chemical compound that has the ability to form H3O ⁺ ions in aqueous solution or to convert OH ^~ ions to water molecules. The chemical effect in the practical use of an acid in this case goes back to the HsO ⁺ ions. If it is lacking in water, the acid can not develop its chemical effect in practical use. According to embodiments, the rust remover contains 50-90 wt%, preferably 70-90 wt% solvent.

The statement wt% stands for weight percent, ie the percentage of the component of its weight in the total weight of the rust remover.

According to embodiments, the solvent is a polar solvent.

According to embodiments it is provided that the solvent contains water, alcohol, ester, ether or another polar solvent, or that the solvent is formed from one or more of these substances.

According to embodiments, the alcohol consists of methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, heptan-1-ol and / or from their homologues propan-2-ol, butan-2-ol , 2-methylpropan-1-ol, 2-methylpropan-2-ol, pentan-2-ol, ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, butane-1 , 2-diol, butane-1, 3-diol, butane-1, 4-diol or butane-2,3-diol and / or from other conventional alcohols according to the prior art.

According to embodiments, the ester consists of acetic acid, stearic acid, palmitic acid or oleic acid esters and / or other esters customary in the art.

According to embodiments, the ether consists of diethyl ether, dihexyl ether, dioctyl ether, didecyl ether, tetrahydrofuran, 1,4-dioxane, oxetane, tetrahydropyran or methylal and / or further ethers customary according to the prior art. According to embodiments, another polar solvent contains dimethylsulfoxide and / or propylene carbonate and / or consists of further polar solvents customary in the prior art.

According to embodiments, the rust remover contains 0.1-5 wt%, preferably 0.1-1, 0 wt% of nonionic surfactants.

According to embodiments, the nonionic surfactants contain fatty alcohol-based surfactants, fatty alcohol ethoxlates, fatty alcohol propoxylates or fatty alcohol polyglucosides or are formed from one or more of these or chemically comparable constituents.

Surfactants or soaps give the rust remover an excellent creep and lubricity, so that the solvent and other functional admixtures, in particular the complexing agent can penetrate into the smallest gaps. Furthermore, the friction forces between the surfaces as such and between particles of dirt or rust or of complexes dissolved from the substrate can be significantly reduced by the lubrication.

According to embodiments, the fatty alcohol-based surfactants are based on 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 1-dodecanol (lauryl alcohol), 1-tetradecanol (myristyl alcohol), 1-hexadecanol (cetyl alcohol), 1-heptadecanol (margaryl alcohol). , 1-octadecanol (stearyl alcohol), 1-eicosanol (arachidyl alcohol), 1-docosanol (behenyl alcohol), 1-tetracosanol (lignoceryl alcohol), 1-hexacosanol (ceryl alcohol), 1-octacosanol (montanyl alcohol), 1-triacontanol (melissyl alcohol ), cis-9-hexadecene-1-ol (palmitoleyl alcohol), cis-9-octadecene-1-ol (oleyl alcohol), trans-9-octadecene-1-ol (elaidyl alcohol), cis-1 1-octadecene-1 - ol or 6,9,12-octadecatrien-1-ol (γ-linolenyl alcohol). According to embodiments, the fatty alcohol ethoxylates and fatty alcohol propoxylates are polyoxyethylene (4) octyl ether, polyoxyethylene (9) decyl ether, polyoxyethylene (23) lauryl ether, polyoxypropylene (9) lauryl ether, polyoxyethylene (10) cetyl ether, polyoxypropylene (10) cetyl ether, Polyoxyethylene (10) stearyl ether, polyoxyethylene (20) oleyl ether or polyoxyethylene (10) tridecyl ether or formed from one or more of these or chemically comparable constituents.

According to embodiments, the fatty alcohol polyglucosides include hexyl, heptyl, octyl, nonyl, decyl, dodecyl, hexadecyl or octadecyl polyglucosides or are formed from one or more of these or chemically comparable ingredients. Thus, other, not listed here nonionic surfactants can be used.

According to embodiments, the rust remover contains 2-30 wt%, preferably 5-20 wt% complexing agent.

According to embodiments, the complexing agent is formed from a hydroxycarboxylic acid or its ester, ketocarboxylic acid or its esters, diketones, amines or their derivatives or from further complexing agents or from one or more of these or chemically comparable constituents.

According to embodiments, in the case of a hydroxycarboxylic acid, the complexing agent is gluconic acid, tartaric acid, tartronic acid, lactic acid, mandelic acid, iso-citric acid, glycolic acid, citric acid, malic acid, beta-hydroxybutyric acid, mevalonic acid, gallic acid, salicylic acid or 4-hydroxybutanoic acid or their respective esters or formed from one or more of these or chemically comparable components.

According to embodiments, in the case of a ketocarboxylic acid, the complexing agent is acetoacetic acid, pyruvic acid, mesoxalic acid or oxalic acid or their respective esters or one or more of these or chemically comparable constituents.

According to embodiments, the diketones are from 2,3-butanedione, 2,4-pentanedione, 2,5-hexanedione, 2,6-heptanedione, 2,7-octanedione or 2,8-nonanedione or from one or more of these or chemically comparable constituents educated.

According to embodiments, the amines are ethylenediamine, diethylenetriamine, triethylenetetramine, triaminotriethylamine, bis (salicylidene) ethylenediamine, ethylenediamine, 2- (2-aminoethylamino) ethanol, diethylenetriamine, iminodiacetate, triethylenetetramine, triaminotriethylamine, nitrilotriacetate, bis (salicylidene) ethylenediamine, ethylene diaminotriacetate , Ethylenediaminetetraacetate, diethylenetriamine pentaacetate, 1, 4,7,10-tetraazacyclododecane-1, 4,7,10-tetraacetate, 2,2'-bipyridine, 1, 10-phenanthroline, dimethylglyoxime or 8-hydroxyquinoline or from the respective derivatives or formed from one or more of these or chemically comparable components.

According to embodiments, further complexing agents contain dimercaptosuccinic acid or 1,2-bis (diphenylphosphino) ethane or are formed from one or more of these or chemically comparable constituents.

According to embodiments, the complexing agent is acid-free.

It is further proposed that at least one corrosion inhibitor is contained.

According to embodiments, the corrosion inhibitor contains a sulphonate, benzoate and / or succinate or is formed from one or more of these or chemically comparable constituents, in particular from constituents based on phosphorus. For example, the corrosion inhibitor comprises an alkaline earth sulfonate or ammonium benzoate. In this way, the rust remover can also be filled with an aqueous solvent in containers made of metal, eg compressed gas packages without attacking the inner wall of such containers. Even without the addition of a corrosion inhibitor rust remover can be much easier filled into normal plastic containers and stored, since the rust remover does not attack plastics as otherwise comparable agents based on mineral oil.

According to embodiments, at least one fragrance is contained in the rust remover.

According to embodiments, the rust remover contains up to 10 wt% fragrances.

According to embodiments, the thickener is a thixotropic and / or pseudoplastic thickener. Embodiments may have the advantage that the viscosity of the rust remover increases by the thickener after application and thus the rust remover adheres drip-free and / or flow inhibited at the application location. For a thixotropic liquid, the viscosity decreases due to prolonged mechanical stress, i. Shear, off. After completion of the stress, the viscosity increases again. In other words, the thixotropic liquid becomes less viscous with the duration of its deformation: With a constant shear, the viscosity decreases with time, and after the end of the shear stress, the viscosity increases again with time.

A pseudoplastic liquid has a decreasing viscosity at high shear forces. In other words, the stronger the shear acting on the liquid, the lower the viscosity of the liquid.

The cause of thixotropy and intrinsic viscosity is similar: as a result of the shear force, the structure in the fluid changes, causing smaller interactions between the particles encompassed by the fluid. After As a result of the shear force, these structural changes are more or less rapidly reflected.

According to embodiments, in the rust remover 0.5-20 wt%, preferably 5-10 wt% thickener included.

According to embodiments, the thickener is based on synthetically organic, naturally organic or inorganic constituents.

Embodiments in which the thickener is an inorganic thickener may be advantageous because inorganic thickeners may form spongy, three-dimensional networks. In the pores of such a network, the solvent with the complexing agent contained therein and the nonionic surfactant as a liquid component can be kept in stock. Because of its resulting gel-like properties, the rust remover can form a depot during application, in particular a depot which is flow-inhibited and / or drip-free by the viscosity of the thickener, for the active ingredients contained. In particular, such a depot can be provided with the solvent, the complexing agent and the nonionic surfactant. The solvent may creep out of the pores along with the complexing agent due to the creep capability of the contained surfactant and penetrate, for example, assisted by the capillary effect, into crevices of the corroded mechanical compound. Due to the gel-like properties of the rust remover, the creeping ability of the liquid component, ie of the solvent with complexing agent and surfactant, is not or only negligibly impaired by the thickener. This can be particularly advantageous if the solvent with the active ingredients contained therein is to penetrate into a deep gap of a corroded mechanical connection: the reservoir can hold a sufficient supply of the liquid component so that it can penetrate deep into the gap. In contrast, in the case of organic thickeners in the solvent, which generally do not form a gel or a depot, and their individual particles or molecular aggregates in the solvent rather are dispersed, missing from a comparable creep ability of the rust remover.

According to embodiments, the synthetic organic constituents contain polyvinyl alcohols, polymethacrylic acids, polyacrylamides, polyvinylpyrrolidone, polyethylene glycols, methylcellulose, hydroxyethylcellulose or carboxymethylcellulose or are formed from one or more of these or chemically comparable constituents.

According to embodiments, the naturally-occurring organic constituents contain starch, pectin, gum arabic, locust bean gum, gelatin, casein or agarose or are formed from one or more of these or chemically comparable constituents.

According to embodiments, the inorganic constituents contain silica gel, kieselguhr, bentonite or graphite or are formed from one or more of these or chemically comparable constituents.

According to embodiments, the rust remover is a gel. The thickener forms as a solid component of the gel a sponge-like, three-dimensional network. In other words, molecular aggregates of the thickener form a three-dimensional reticular matrix. The pores of the network formed by the thickener comprise the solvent with the complexing agent contained therein and the nonionic surfactant as the liquid component of the gel.

According to embodiments, when applied to the corroded mechanical bond by the thickener at the point of application, the gel forms a drip-free and / or flow-inhibited depot. Furthermore, the gel at an interface between the depot and the metallic surfaces of the corroded mechanical For example, the nonionic surfactant compound provides a creep capability of the solvent with the surfactant and complexing agent contained therein.

According to embodiments, the rust remover is formed by the thickener after application to an object drip-free and flow inhibited and thus adheres in the form of a depot, wherein at the interface between the rust remover and the surface to be treated by the nonionic surfactants creep capability is provided. Thus, the solvent and contained Funktionsbeimengungen, in particular surfactants and complexing agents in the form of a capillary film from the depot exit.

The capillary action produced by means of the nonionic surfactants or soaps is surprisingly not impaired here despite the addition of the thickener or can be matched to one another by adjusting the respective weight proportions, in particular by the ratio of the weight proportions of the surfactants to the proportions by weight of the thickener.

According to embodiments, the rust remover contains at least one propellant.

According to embodiments in the rust remover 0-30 wt%, preferably 15-30 wt% propellant.

According to embodiments, the blowing agent contains dimethyl ether, propane, butane, isobutane, carbon dioxide, nitrogen or nitrous oxide or is formed from one or more of these or chemically comparable substances.

According to embodiments, the rust remover contains at least one lubricant.

According to embodiments, 5-40 wt% lubricants are included. According to embodiments, the lubricant contains fatty acid ester or dialkyl ether or is formed from one or more of these or chemically comparable substances.

In a further aspect, the invention relates to a method for releasing a corroded mechanical connection of metallic surfaces with a rust remover according to one of the embodiments described above. The method comprises:

Applying the rust remover to the corroded mechanical connection;

• action of the rust remover on the corroded mechanical connection,

Moving at least a first of the metallic surfaces relative to a second one of the metallic surfaces so that the corroded mechanical

Connection between first and second mechanical surface is solved.

The rust remover is used in particular for the treatment of oxide layers. For example, the rust remover is applied to the rust-infested surface of an object, allowed to act and then removed. This can be done, for example, by washing with water, with a cloth or a cleaning agent.

According to embodiments, the action comprises:

Forming a depot of the rust remover at the point of application by the thickener,

• leakage of the solvent with the surfactant contained therein and

Complexing agent in at least one capillary film between the metallic surfaces of the corroded mechanical compound,

At least partially complexing and releasing a corrosion layer between the metallic surfaces of the corroded mechanical compound by the complexing agent,

• Dissolving and / or dissolving particles of the dissolved complexes in the

Solvent and the nonionic surfactant contained therein,

Reduction of the frictional resistance between the metallic surfaces, wherein the reduction of the frictional resistance comprises smearing of the dissolved complexes by the nonionic surfactant. According to embodiments, the viscosity of the rust remover increases after application to the surface.

According to embodiments, the rust remover adheres to the object after application to the object, in particular, the rust remover adheres drip-free and / or flow inhibited.

According to embodiments, the rust remover forms a depot after application at the point of application.

According to embodiments, solvent and the functional admixtures contained in the solvent, in particular surfactants and complexing agents, emerge from the depot in a capillary film.

According to embodiments, the oxide layer is at least partially complexed by the complexing agent contained in the solvent. That the metal ion from the oxide layer forms a chelate complex with the complexing agent.

According to embodiments, the complexes of the oxide layer formed are at least partially detached from the substrate, so that surfaces of adjacent objects which are firmly corroded to one another can be detached from one another or can be loosened with little effort.

According to embodiments, particles of the dissolved complexes as well as dirt particles in the solvent and the nonionic surfactants contained therein are dispersed and lubricated, thus supporting the loose process of the adjacent objects until complete separation.

According to embodiments, the rust remover is used as a screw release for releasing a corroded mechanical connection comprising a threaded connection. For example, the rust remover for releasing a screw or other screw with screw thread from a recording with

Screw thread for receiving the screw or the screw. After exiting Guides both threads have a metallic surface and form a positive and / or non-positive mechanical connection.

According to embodiments, the rust remover is used as an injector remover for releasing an injector from a corroded mechanical connection with an injector housing, for example in a cylinder head. An injector may generally serve to inject reagents into a process chamber, for example, fuel into a combustion chamber of an engine. Under an injector, here e.g. an injection valve of a diesel engine understood, which is also referred to as an injection nozzle and is arranged in a receptacle in a cylinder head of the diesel engine. An injection nozzle generally consists of a nozzle body and a nozzle needle. An injector is fixed in the cylinder head, for example, by frictional engagement, in particular negative pressure, and / or by positive locking using a holding element, such as a clamping claw. Embodiments may have the advantage that the rust remover assists in releasing an injector in which the screw for fixing the clamping claw to the cylinder head, the clamping claw on the injector or the injector itself stuck in the seat of the cylinder head due to corrosion. In this case, the rust dissolver can have the advantage, in particular with regard to the elongated geometrical configuration of the injector, that the rust remover can adhere and act on its application site due to its gel-like properties and the viscosity provided by the thickener. Further, by virtue of its gel-like properties, in particular the provision of a depot, and the penetrability provided by the surfactant, the rust-proofing due to capillary action can penetrate as a film between the surface of the injector and the surface of the injector receptacle, preferably over the entire length of the injector and act. This allows an efficient and effective release of the injector from the recording.

According to further embodiments, the rust remover is used, for example, for releasing a glow plug or a spark plug from a corroded mechanical connection with a glow plug or spark plug receptacle of a cylinder head. Further features, details and advantages of the invention will become apparent from the claims, the wording of which is incorporated by reference into the content of the description. The abovementioned features and those to be explained below can be used not only in the particular combination specified, but also in other combinations or in isolation, without departing from the scope of the present invention.

In a first embodiment for a treatment of iron-containing materials with a spray, the rust remover is formed from:

In a third embodiment, the rust remover is for a treatment of aluminum objects with a spray formed from: C6 alcohol ethoxylate 0.3%

Ethanol 52.5%

Water 13.1%

Silica gel hydrophilic 14.4%

Citric acid 3.9%

In a fourth embodiment, the rust remover for a spray is anhydrous formed from:

Constituent wt%

Propane / butane 25

C12 alcohol ethoxylate 0.6

Ethanol 49

Dipropylene glycol 1, 1

Didodecyl ether 12.3

Silica gel hydrophilic 4.3

Gallic acid methyl ester 0.7

2,3-Butanedione 7.0 In a fifth exemplary embodiment for a coating of ferrous materials, the rust remover is anhydrous as an aqueous product of:

Embodiments of the invention are illustrated in the following drawings and are explained in more detail in the following description. Hereby show:

Fig. 1 object with a partial section containing a thread, a

Screw, 2 object with rust remover applied,

3 object with rust remover after exposure time,

Fig. 4 partial section of Fig. 3 with an enlarged view

Fig. 5 object with rust remover after further exposure.

Fig. 6 partial detail of Fig. 5 with an enlarged view

Fig. 7 reaction equation

Fig. 1 shows schematically an object 10 with an internal thread 1 1, in which a screw 20 is screwed. It is assumed that a screw connection of ferrous materials. From the material of the object 10, rust 40 has formed on the surface of the internal thread as well as on the thread of the screw 20. The facing or abutting, corroded surfaces are at least partially fused together or hooked by the volume increase and increased roughness associated with the corrosion. By bonding the rust layers to the respective substrate object and screw can not move relative to each other, they are festkorroded together. As a result, the screw 20 is seized in the threaded hole and normally can be solved again only with great effort.

Fig. 2 shows the applied to the screw rust remover 50 in the form of a rust remover. The rust remover 50 is optimally applied so that it is placed at the boundary object / screw. The thickener 54 prevents the agent from draining or dripping even in overhead applications (Figure 2b) and on vertical surfaces (Figure 2c). In the case of thixotropic thickeners 54, the effect is particularly pronounced in the spray can application, in which the high shear during spraying leads to a greatly reduced viscosity. Thus, the rust remover 50 is less viscous and can be applied more easily from a compressed gas package. On the way to the object 10 and its surface already evaporates a part of the solvent and blowing agent. The resulting shearing action leads within a very short time to the increase in viscosity, so that the rust remover 50 in contact with the object 10 or its surface adheres well there and a kind Depot 60 forms. The same would apply to a rust remover without propellant, although not so pronounced here, since the effect of the outgassing propellant is missing here. Usually, polymer-based thickeners are used. Polymeric thickeners are dissolved in the liquid and, so to speak, act on the liquid as a whole. However, this prevents the further escape of low-viscosity components, namely the solvent together with the functional admixtures. Fig. 3 shows the applied rust remover 50 of FIG. 2 after a certain exposure time. The figures are only schematic and in particular the dimensions are shown here only approximately proportionally. At the boundary object 10 / screw 20 is a gap 30. The rust remover 50 is preferably applied so that the depot 60 is in the vicinity of the gap 30.

The (inorganic) thixotropic thickener or thixotropic agent 54 is a non-soluble, solvent-dispersed solid, so that unlike (organic) polymeric thickening agents, the solvent together with the other admixtures of the thickened and adhesive suspension still as creep, low-viscosity liquid in Form of a capillary film 70 can escape. According to further embodiments, it is a pseudoplastic thickener 54, which also allows the formation of a capillary film 70. As a result of the gel-like properties of the rust remover provided by the thickener 54, the depot 60 is formed and held together by the sponge-like, three-dimensional network constituting the molecular aggregates of the thickener 54. The liquid contained in the capillary film 70 is always in contact with the depot 60, wherein the volume required for further expansion is taken from the depot 60. The further the extent of the capillary film, the more stretch the solvent has to travel from the depot 60. The liquid contained in the capillary film 70 therefore runs progressively more slowly at a greater distance from the depot and finally stops altogether when no more supplies are coming from the depot. The liquid or the solvent 51 and the contained therein Active substances, in particular the surfactants 52 and the complexing agent 53, therefore only extend to a certain extent. In this case, the leaked and very low-viscosity solvent does not drip even under the influence of gravity G, since it is completely contained in a capillary layer 70 after leaving the depot 60.

The capillary layer also extends into the gap 30, transporting the low-viscosity solvent 51 leaving the depot 60 together with the further constituents contained therein and thus the active substances, in particular the surfactants 52 and the complexing agent 53, due to the particularly strong in the gap acting capillary forces K. Thus, the solvent 51 moves down with the active substances contained therein along the entire screw down. The thickener 54 remains in the depot 60. The volume of the depot decreases as long as solvent still emerges.

As soon as the complexing agents come into contact with the rust layers 40, the rust layers 40 or rust particles are transformed into complexes 45 (FIG. 4). This happens at the two opposite surfaces of the object 10 and screw 20 at the same time.

The complexes are at least partially detached from the substrate and dissolved or dispersed in the gap or in the thread penetrated solvent (Fig. 6). The opposing surfaces of the object 10 and the screw 20 are thus no longer fixed to each other via the rust layers 40 of the opposite surfaces (FIG. 5). The screw 20 can be rotated relative to the object 10 again and so remove a total of the internal thread 1 1. In this case, the surfaces are lubricated by the surfactants 52 contained in the solvent 51, as well as the dispersed soil, rust and complex particles 40 and 45, so that the dissolving process is further assisted.

After separation or after successful treatment of oxidized surfaces, for example, they are cleaned with water and, as a precaution, protected against renewed oxidation. FIG. 7 shows the corresponding reaction equation with a complexing agent for iron ions or against red rust.

Possible embodiments include, for example, the following feature combinations: 1. Substance 50, in particular a rust remover, for application to an object 10 with a surface oxide layer 40, in particular on a connecting element, in particular on a connecting element with a thread 20, comprising a solvent 51, nonionic surfactants 52 and at least one complexing agent 53 for metal ions. 2. Substance 50 according to item 1, characterized in that 50-90 wt%,

preferably 70-90 wt% of solvent 51 are contained.

Substance 50 according to item 1 or 2, characterized in that the solvent 51 is a polar solvent.

Substance 50 according to one of the preceding points, characterized

in that the solvent contains water, alcohol, ester, ether or another polar solvent, or that the solvent is formed from one or more of these substances.

Substance 50 according to one of the preceding points, characterized

in that 0.1-5% by weight, preferably 0.1-1.0% by weight, of nonionic surfactants 52 are contained.

6. Substance 50 according to the preceding point, characterized in that the nonionic surfactants contain fatty alcohol-based surfactants, fatty alcohol ethoxlates and propoxylates or fatty alcohol polyglucosides or are formed from one or more of these or chemically comparable components.

7. Substance according to one of the preceding points, characterized in that 2-30 wt%, preferably 5-20 wt% complexing agent 53 are included.

8. Substance 50 according to the preceding point, characterized in that the complexing agent 53 is formed from a hydroxycarboxylic acid or its ester, ketocarboxylic acid or its esters, diketones, amines or derivatives thereof or from further complexing agents or from one or more of these or chemically comparable constituents ,

9. Substance 50 according to one of the preceding points, characterized

characterized in that at least one corrosion inhibitor is included.

10. Substance 50 according to the preceding point, characterized in that the corrosion inhibitor contains alkaline earth sulfonates, sodium benzoate or succinates or from one or more of these or chemically comparable constituents, in particular from constituents

Phosphorus base is formed.

1 1. Substance 50 according to one of the preceding points, characterized

characterized in that fragrances are included.

12. Substance 50 according to one of the preceding points, characterized

characterized in that at least one thickener 54, in particular a

Thixotropic agent is included. Substance 50 according to the preceding point, characterized in that preferably 0.5-20 wt%, more preferably 5-10 wt% thickener 54 are included.

Substance 50 according to the preceding point, characterized in that the thickener 54 based on synthetic organic, natural organic or inorganic constituents.

Substance 50 according to any one of the preceding items 1 1 -13, characterized in that the substance 50 after application by the thickener 54 is drip-free and flow-inhibited, wherein at the interface between substance 50 and a surface by the nonionic surfactants 52, a creep capability is provided ,

Substance 50 according to one of the preceding points, characterized

characterized in that propellant is included.

Substance 50 according to the preceding point, characterized in that up to 0-30 wt%, preferably 15-30 wt% propellant are included.

Substance 50 according to the preceding point, characterized in that the propellant contains dimethyl ether, propane, butane, isobutane, carbon dioxide, nitrogen or nitrous oxide or is formed from one or more of these or chemically comparable substances.

Method for treating objects 10 with an oxide layer 40, characterized in that the substance 50 is applied to a surface according to one of the items 1 to 18, allowed to act and then removed. Method for treating objects 10 according to the preceding point, characterized in that the viscosity of the substance 50 increases after application to the surface.

Method for the treatment of objects 10 according to one of the preceding points 19-20, characterized in that the substance 50 adheres to the object 10 after being applied to the object 10, in particular that the substance 50 adheres drip-free.

Method for the treatment of objects 10 according to one of the preceding points 19-21, characterized in that the substance 50 forms a depot 60 after application at the point of application.

Method for treating objects 10 according to one of the preceding points 19-22, characterized in that the depot 60

Solvent 51 and those contained in the solvent

Functional admixtures, in particular surfactants 52 and complexing agent 53 in a capillary film 70 emerges.

Method for the treatment of objects 10 according to one of the preceding points 19-23, characterized in that the oxide layer 40 is at least partially complexed.

Method for the treatment of objects 10 according to the preceding point, characterized in that the formed complexes 45 of the oxide layer 40 are at least partially detached from the substrate so that surfaces of adjacent objects 10 solidly corroded to each other are loosened

be solved from each other. Method for the treatment of objects 10 according to one of the preceding points 19-25, characterized in that particles of the dissolved complexes 45 and dirt particles in the solvent 51 and the nonionic surfactants 52 contained therein are dispersed and lubricated one another, and thus the loose process of the adjacent objects 10 support until complete separation.

Numeral 1 iste

10 object

11 internal thread

20 screw

30 gap

40 oxide particles

45 metal complex

50 substance

51 Solvent

52 surfactants

53 complexing agents

54 thickener

60 depot

70 capillary film

K capillary force

G gravity

Claims

Patent claims

1 . Rust remover (50) for releasing a corroded mechanical connection of metallic surfaces, the rust remover (50) comprising: at least one solvent (51), at least one thickener (54), at least one complexing agent (53) for metal ions and at least one nonionic surfactant (52).

2. rust remover (50) according to claim 1, wherein the rust remover (50) is acid and / or anhydrous.

3. rust remover (50) according to any one of claims 1 or 2, wherein the thickener (54) is a thixotropic and / or pseudoplastic thickener (54).

4. rust remover (50) according to any one of the preceding claims, wherein the thickener (54) is an inorganic thickener (54).

5. rust remover (50) according to claim 4, wherein the thickener (54) comprises silica gel, diatomaceous earth, bentonite and / or graphite.

6. rust remover (50) according to any one of the preceding claims, wherein the rust remover (50) is a gel and wherein the thickener (54) as a solid component of the gel forms a sponge-like, three-dimensional network, the pores of the solvent (51) with the therein comprising complexing agent (53) and nonionic surfactant (52) as a liquid component of the gel.

The rust remover (50) of claim 6, wherein the gel, when applied to the corroded mechanical bond by the thickener (54) at the application site, forms a drip-free and / or flow-inhibited deposit (60) and wherein the gel is interposed at an interface the depot (60) and the metallic surfaces of the corroded mechanical connection through the nonionic surfactant (52) provides a creep capability of the solvent (51) with the surfactant (52) and complexing agent (53) contained therein.

8. rust remover (50) according to any one of the preceding claims, wherein the

Solvent (51) is a polar solvent and in particular comprises alcohol, esters and / or ethers.

9. rust remover (50) according to any one of the preceding claims, wherein the

nonionic surfactant is a fatty alcohol-based surfactant, in particular

Fatty alcohol ethoxylate and fatty alcohol propoxylates and / or fatty alcohol polyglucosides.

10. rust remover (50) according to any one of the preceding claims, wherein the

Complexing agent (53) comprises an ester of a hydroxycarboxylic acid, an ester of a ketocarboxylic acids, a diketone, an amine and / or its derivative.

1 1. Rust remover (50) according to one of the preceding claims, wherein the

Rust remover (50) further comprises at least one corrosion inhibitor, wherein the corrosion inhibitor comprises in particular a sulfonate, benzoate and / or succinate and in particular a component based on phosphorus.

12. Method for releasing a corroded mechanical connection

metallic surfaces with a rust remover (50) according to any one of the preceding claims, the method comprising:

• Apply the rust remover (50) to the corroded mechanical

Connection,

• Exposure of the rust remover (50) to the corroded mechanical

Connection,

Moving at least a first of the metallic surfaces relative to a second one of the metallic surfaces so that the corroded one mechanical connection between the first and second mechanical surface is solved.

13. The method of claim 12, wherein the act comprises:

Forming a depot (60) of the rust remover (50) at the point of application by the thickener (54),

Egress of the solvent (51) with the surfactant (52) and complexing agent (53) contained therein in at least one capillary film (70) between the metallic surfaces of the corroded mechanical compound,

At least partially complexing and releasing a corrosion layer between the metallic surfaces of the corroded mechanical compound by the complexing agent (53),

Dissolving and / or dissolving particles of the dissolved complexes (45) in the

Solvent (51) and the nonionic surfactant (52) contained therein,

• Reduction of frictional resistance between the metallic ones

Surfaces, wherein the reduction of frictional resistance comprises lubricating the dissolved complexes (45) by the nonionic surfactant (52).

14. The method according to any one of claims 12-13, wherein the rust remover (50) after application adheres drip-free and / or flow inhibited at the application site and / or wherein the viscosity of the thickener (54) after the

Application increases.

15. The method according to any one of claims 12-14, wherein the rust remover (50) as

A screw release is used to dislodge a corroded mechanical connection comprising a threaded connection, or wherein the rust remover (50) is used to disengage an injector, a spark plug or a glow plug from a corroded mechanical connection with a receptacle.