DE102016107681A1 - Substance for dissolving corrosion layers - Google Patents

Abstract

Substance for application to an object with a superficial oxide layer, in particular on a connecting element, in particular on a connecting element with a thread, comprising a solvent, nonionic surfactants and at least one complexing agent for metal ions.

Description

The invention relates to a substance for dissolving corrosion layers and to a method for using this substance.

Metals have the property of corroding on their surfaces, i. the metals form a chemical compound with oxygen from the environment and form an oxide layer. For a number of metals, e.g. Zinc, copper, chrome, etc., this is not a major problem, because the oxide layer thus formed shields the surface of the surrounding atmospheric oxygen and prevents further corrosion. As a rule, corrosion of such metals comes to a standstill.

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).

The problem is especially serious in many mechanical connections with ferrous 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 one differentiates roughly between rust converters, rust pickling and rust removers.

Rust converters are liquid mixtures that convert the rust into stable, non-porous ferric oxide compounds through a chemical conversion process. This reduces moisture absorption and suppresses further corrosion. Rust converter can be due to the most aqueous composition on the given viscosity still thickened with suitable means to increase the viscosity, so that the substance does not flow away or dripping, but long on the object to the problem zone and there acts to those for the desired Change most needed 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 iron-containing base material. For general application to 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 commercially available rust removers contain additives such as graphite dust or MoS ₂ in order to increase the lubricating effect of the oil and also to ensure it under high pressure. However, with rust removers of the prior art, the composition is hardly improved because of the composition achieved in the actual disengagement of a screw connection, but it is only the friction value is reduced when a connection has already been solved. That is, 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.

An example of prior art rust remover is disclosed in U.S. Pat US 2005 027 26 14 A1 describes and discloses a surface treatment for metals comprising a composition of an acid rust inhibitor, a neutral alkaline earth metal sulfonate as a first corrosion inhibitor component, a second corrosion inhibitor component based on phosphorus and a creepable mineral oil as a solvent.

The fact that the commercial rust remover are low viscosity by 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 substance 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 by means of thickening agents, e.g. with long-chain polymers (including 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 thus to provide an improved substance for the treatment of oxide layers and a method for the use of such a substance.

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

The invention provides a substance for application to an object with a surface oxide layer comprising a solvent, nonionic surfactants and at least one complexing agent for metal ions, e.g. Iron.

The advantage of this substance is one of mineral oil and in its initial version also kept free of acids substance with the metal oxides, mainly iron oxide (rust) or alumina are converted by chemical reaction into corresponding metal complexes. The metal oxide thus treated or the complexes formed are thereby dissolved from the substrate, the oxide layer is at least partially removed. If the substance is used for loosening a screw connection, the release of the firmly corroded surface layers is actively supported. The creeping ability of the substance is ensured by means of the contained nonionic surfactants or soaps, which also lubricate the parts which are primarily dissolved from one another during the further separation and thus further support the dissolving process.

In a further development of the invention it is provided that 50-90 wt%, preferably 70-90 wt% solvent are included.

The expression wt% stands for weight percent, ie the percentage of the component of its weight in the total weight of the substance.

In a further development of the invention, the solvent is a polar solvent.

In a further development of the invention, 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.

It is particularly advantageous that the alcohol from methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, heptan-1-ol, and / or from their homologues propan-2-ol, butane 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 other, conventional in the art alcohols.

It is particularly advantageous that the ester consists of acetic acid, stearic acid, palmitic acid or oleic acid esters and / or of further conventional esters according to the prior art.

It is particularly advantageous that the ether consists of diethyl ether, dihexyl ether, dioctyl ether, didecyl ether, tetrahydrofuran, 1,4-dioxane, oxetane, tetrahydropyran or methylal, and / or other, customary according to the prior art ethers.

It is particularly advantageous that another polar solvent contains dimethyl sulfoxide and / or propylene carbonate and / or consists of other conventional polar solvents according to the prior art.

In a further development of the invention, it is proposed that 0.1-5% by weight, preferably 0.1-1.0% by weight, of nonionic surfactants are contained.

It is advantageous 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 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.

It is advantageous that 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-hexadecen-1-ol (palmitoleyl alcohol), cis-9-octadecen-1-ol (oleyl alcohol), trans-9-octadecen-1-ol (elaidyl alcohol), cis-11-octadecen-1-ol or 6,9,12-octadecatrien-1-ol (γ-linolenyl alcohol).

It is particularly advantageous that the fatty alcohol ethoxylates and propoxylates of 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 ethers, polyoxyethylene (20) oleyl ethers or polyoxyethylene (10) tridecyl ethers or are formed from one or more of these or chemically comparable constituents.

It is particularly advantageous that the fatty alcohol polyglucosides hexyl, heptyl, octyl, nonyl, decyl, dodecyl, hexadecyl or octadecyl polyglucosides contain or are formed from one or more of these or chemically comparable components. Thus, other, not listed here nonionic surfactants can be used.

In a further development of the invention it is proposed that 2-30 wt%, preferably 5-20 wt% complexing agent is included.

It is preferred that the complexing agent is formed from a hydroxycarboxylic acids or their esters, keto-carboxylic acids or their esters, diketones, amines or derivatives thereof or from further complexing agents or from one or more of these or chemically comparable constituents.

Particularly advantageous is that the hydroxycarboxylic acid, from 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 one or more of these or chemically comparable constituents.

It is particularly advantageous that the ketocarboxylic acid is formed from acetoacetic acid, pyruvic acid, mesoxalic acid or oxalic acid or their respective esters or from one or more of these or chemically comparable constituents.

It is particularly advantageous that the diketones of 2,3-butanedione, 2,4-pentanedione, 2,5-hexanedione, 2,6-heptanedione, 2,7-octanedione or 2,8-nonanedione or one or more of these or chemical comparable components are formed.

It is particularly advantageous that the amines of ethylenediamine, diethylenetriamine, triethylenetetramine, triaminotriethylamine, bis (salicylidene) ethylenediamine, ethylenediamine, 2- (2-aminoethylamino) ethanol, diethylenetriamine, iminodiacetate, triethylenetetramine, triaminotriethylamine, nitrilotriacetate, bis (salicylidene) ethylenediamine, ethylenediaminotriacetat , 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 from one or more of these or chemically comparable components are formed.

It is particularly advantageous that the 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.

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

It is preferred that the corrosion inhibitor contains alkaline earth sulfonates, sodium benzoate or succinates or is formed from one or more of these or chemically comparable constituents, in particular from constituents based on phosphorus.

As a result, the substance can also be mixed with an aqueous solvent in containers of metal, e.g. Aerosols are filled without attacking the inner wall of such containers. Even without the addition of a corrosion inhibitor, the substance can be much easier filled into normal plastic containers and stored, since the substance does not attack plastics as otherwise comparable mineral oil-based agents.

It is advantageous that fragrances are included.

It is particularly advantageous that up to 10 wt% fragrances are included.

In a development of the invention, at least one thickener, in particular a thixotropic agent, is contained.

It is preferred that preferably 0.5-20 wt%, more preferably 5-10 wt% thickener are included.

It is advantageous that the thickener is based on synthetically organic, naturally organic or inorganic constituents.

It is particularly advantageous that 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.

It is particularly advantageous that the naturally 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.

It is particularly advantageous that the inorganic constituents contain silica gel, kieselguhr, bentonite or graphite or are formed from one or more of these or chemically comparable constituents.

It is advantageous that the substance 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 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 the coordination of the respective weight fractions, in particular by the ratio of the proportions by weight of the surfactants to the proportions by weight of the thickener.

In a further development of the invention it is proposed that propellant is included.

It is preferred that 0-30 wt%, more preferably 15-30 wt% propellant are included.

It is particularly advantageous 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.

In a further development of the invention it is proposed that at least one lubricant is contained.

It is preferred that 5-40 wt% lubricant are included.

It is particularly advantageous that the lubricant contains fatty acid esters or dialkyl ethers or is formed from one or more of these or chemically comparable substances.

In another aspect, the invention relates to a method of treating oxide layers. The substance is applied to the rust-infested surface of an object, left to work and then removed. This can be done by washing with water, cloth or detergent.

It is advantageous that the viscosity of the substance increases after application to the surface.

It is advantageous that the substance adheres to the object after application to the object, in particular that the substance adheres drip-free.

It is particularly advantageous that the substance forms a depot after application at the place of application.

It is preferred that solvents and the functional admixtures contained in the solvent, in particular surfactants and complexing agents, emerge from the depot in a capillary film.

It is advantageous that 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.

It is particularly advantageous that the formed complexes of the oxide layer are at least partially detached from the substrate so that surfaces of adjacent objects which are firmly corroded to one another are detached from one another.

It is particularly advantageous that particles of the dissolved complexes and dirt particles in the solvent and the nonionic surfactants contained therein are dispersed and lubricated each other, and thus support the dissolution process of the adjacent objects until complete separation.

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 indicated, but also in other combinations or alone, without departing from the scope of the present invention.

In a first embodiment for a treatment of iron-containing materials with a spray, a substance according to the invention is formed from: component wt% Propane / butane 25 C10 alcohol ethoxylate 0.6 butanol 9 dipropylene 1.1 water 40 stearate 11.3 Silica gel hydrophilic 5.3 propyl salicylate 0.2 Pentane-2,4-dione 7.5

In a second example of a coating of ferrous materials, a substance according to the invention is formed from: component wt% C8-C10 polyglucoside 3.8 isopropanol 9.4 Propyleneglycolmethylether 9.4 water 47.1 didecyl 18.8 Silica gel hydrophilic 7.5 acetoacetic 0.2 methyl salicylate 3.8

In a third embodiment, a substance according to the invention for a treatment of objects made of aluminum with a spray is formed from: component wt% Propane / butane 15.7% C6 alcohol 0.3% ethanol 52.5% water 13.1% Silica gel hydrophilic 14.4% citric acid 3.9%

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

Hereby show:

1 Object with a partial section, containing a thread, a screw,

2 Object with applied substance,

3 Object with substance after exposure,

4 Partial section off 3 with enlarged view

5 Object with substance after further exposure.

6 Partial section off 5 with enlarged view

7 reaction equation

1 schematically shows an object 10 with an internal thread 11 in which a screw 20 is screwed. It is assumed that a screw connection of ferrous materials. From the material of the object 10 Has on the surface of the internal thread as well as on the thread of the screw 20 rust 40 educated. 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. This causes the screw 20 is seized in the threaded hole and normally can be solved again only with great effort.

2 shows the substance applied to the screw connection 50 in the form of a rust remover. The substance 50 is optimally applied so that it is placed at the boundary object / screw. The thickener 54 prevents draining or dripping of the agent even in overhead applications ( 2 B ) and on vertical surfaces ( 2c ). For thixotropic thickeners 54 In the case of spray can application in particular, the effect is clear, in which the strong shear during spraying leads to a greatly reduced viscosity. That's the substance 50 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 substance 50 when in contact with the object 10 or its surface adheres well there and a kind of depot 60 forms. The same would apply to a substance 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.

3 shows the applied substance 50 from the 2 after a certain exposure time. The figures are only schematic and in particular the dimensions are shown here only approximately proportionally. At the border object 10 / Screw connection 20 there is a gap 30 , The substance 50 is preferably applied so that the depot 60 near the gap 30 located. The thixotropic agent selected according to the invention 54 is a non-soluble solid dispersed in the solvent, so unlike polymeric thickeners, the solvent, along with the other admixtures of the thickened and adherent suspension, still acts as a creepable, low viscosity liquid in the form of a capillary film 70 can escape. The capillary film 70 contained liquid is always in contact with the depot 60 , where the volume necessary for further expansion from the depot 60 is related. The further the expansion of the capillary film, the more stretch the solvent from the depot 60 return. The capillary film 70 The liquid contained in the deposit therefore runs progressively more slowly at a greater distance from the depot and ultimately stops altogether when the depot is no longer supplied. The liquid or the solvent 51 as well as the active substances contained therein, in particular the surfactants 52 and the complexing agent 53 , therefore runs only to a certain extent. In this case, the leaked and very low viscosity solvent does not drip even under the influence of gravity G, as it exits from the depot 60 completely in a capillary layer 70 is included.

The capillary layer also extends into the gap 30 into it and transports the low-viscosity, from the depot 60 leaking solvents 51 together with the other constituents contained therein and thus the active substances, in particular the surfactants 52 and the complexing agent 53 , due to the capillary forces K acting particularly strongly in the gap, the solvent migrates 51 with the active substances contained in it down the whole screw. The thickener 54 remains in the depot 60 , The volume of the depot decreases as long as there is still solvent leakage.

Once the complexing agent with the rust layers 40 come in contact, the rust layers 40 or rust particles transformed into complexes ( 4 ). This happens on the two opposite surfaces of the object 10 as well as screw 20 simultaneously.

The complexes are at least partially detached from the substrate and dissolved or dispersed in, penetrated into the gap or in the thread solvent. ( 6 ). The opposite surfaces of the object 10 and the screw 20 are no longer so about the rust layers 40 the opposite surfaces festkorroded ( 5 ). The screw 20 can be compared to the object 10 turn it again and so out of the internal thread 11 remove. The surfaces are going through those in the solvent 51 contained surfactants 52 as well as the dispersed soil, rust-40 and complex particles 45 lubricated, so that the dissolution process is further supported.

After separation or after successful treatment of oxidized surfaces they are cleaned with water and protected as a precaution against re-oxidation.

7 shows the corresponding reaction equation with a complexing agent for iron ions or against red rust.

LIST OF REFERENCE NUMBERS

10

object

11

inner thread

20

screw

30

gap

40

oxide particles

45

metal complex

50

substance

51

solvent

52

surfactants

53

complexing

54

thickener

60

depot

70

capillary

K

capillary force

G

gravity

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 20050272614 A1 [0013]

Claims (26)

substance 50 for application to an object 10 with a superficial 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. substance 50 according to claim 1, characterized in that 50-90 wt%, preferably 70-90 wt% solvent 51 are included. substance 50 according to claim 1 or 2, characterized in that the solvent 51 is a polar solvent. substance 50 according to any one of the preceding claims, 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 any one of the preceding claims, characterized in that 0.1-5 wt%, preferably 0.1-1.0 wt% nonionic surfactants 52 are included. substance 50 according to the preceding claim, 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 constituents. Substance according to one of the preceding claims, characterized in that 2-30 wt%, preferably 5-20 wt% complexing agent 53 are included. substance 50 according to the preceding claim, characterized in that the complexing agent 53 from a hydroxycarboxylic acids or their esters, keto-carboxylic acids or their esters, diketones, amines or derivatives thereof or from further complexing agents or from one or more of these or chemically comparable constituents. substance 50 according to any one of the preceding claims, characterized in that at least one corrosion inhibitor is contained. substance 50 according to the preceding claim, characterized in that the corrosion inhibitor contains alkaline earth sulfonates, sodium benzoate or succinates or is formed from one or more of these or chemically comparable constituents, in particular from components based on phosphorus. substance 50 according to one of the preceding claims, characterized in that fragrances are contained. substance 50 according to one of the preceding claims, characterized in that at least one thickener 54 , in particular a thixotropic agent is contained. substance 50 according to the preceding claim, characterized in that preferably 0.5-20 wt%, particularly preferably 5-10 wt% thickener 54 are included. substance 50 according to the preceding claim, characterized in that the thickener 54 based on synthetically organic, naturally organic or inorganic components. substance 50 according to any one of the preceding claims 11-13, characterized in that the substance 50 after application by the thickener 54 drip-free and flow-inhibited, being at the interface between substance 50 and a surface by the nonionic surfactants 52 a creep capability is provided. substance 50 according to any one of the preceding claims, characterized in that blowing agent is contained. substance 50 according to the preceding claim, characterized in that up to 0-30 wt%, preferably 15-30 wt% propellant are included. substance 50 according to the preceding claim, characterized in that 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. Method of treating objects 10 with an oxide layer 40 , characterized in that the substance 50 according to any one of claims 1-18 applied to a surface, left to act and then removed. Method of treating objects 10 according to the preceding claim, characterized in that the viscosity of the substance 50 after application to the surface increases. Method of treating objects 10 according to one of the preceding claims 19-20, characterized in that the substance 50 after applying to the object 10 at the object 10 adheres, in particular, that the substance 50 adheres drip-free. Method of treating objects 10 according to one of the preceding claims 19-21, characterized in that the substance 50 after application at the place of application a depot 60 forms. Method of treating objects 10 according to one of the preceding claims 19-22, characterized in that from the depot 60 solvent 51 and the functional admixtures contained in the solvent, in particular surfactants 52 and complexing agents 53 in a capillary film 70 exit. Method of treating objects 10 according to one of the preceding claims 19-23, characterized in that the oxide layer 40 is at least partially complexed. Method of treating objects 10 according to the preceding claim, characterized in that the complexes formed 45 the oxide layer 40 be at least partially detached from the substrate, so that festkorroded surfaces of adjacent objects 10 be solved from each other. Method of treating objects 10 according to any one of the preceding claims 19-25, characterized in that particles of the dissolved complexes 45 as well as dirt particles in the solvent 51 and the nonionic surfactants contained therein 52 dispersed and lubricated each other, and so the dissolving process of the adjacent objects 10 support until complete separation.

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