DE1546161B2 - METHOD FOR CLEANING METAL OBJECTS AND CLEANING COMPOUNDS - Google Patents

Description

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Cleaning, oxide layer removal and degreasing 4 which facilitate the implementation of the process, of metal objects to be plated. This combination of substances causes rapid and no, why the creation of a novel and at the same time the different and so far separated improved cleaning compound was necessary. The degreasing operations carried out, the drive should be carried out in a single container - 5 oxide layer removal, dirt removal and des be barely to ensure a great economy of etching, while negating the problem of hydrogen. It should thereby practically eliminate constant and careful brittleness. The cleaning supervision several treatment baths and the mass is made up of the water-soluble mixture Transfer of metal objects from a bath to one suitable for removing metal oxides to make the other superfluous and eliminate it. io acid, an inhibitor that inhibits hydrogen inhibition In addition, the new cleaning process had to be able to inhibit, and a superficial one simple, cheap and with reproducible yield-active means that combine the functions of the ness be feasible. Metal wetting, oxide layer removal, dirt

The invention relates to a process for removing and emulsifying oils. Cleaning of metal objects for the subsequent 15 In the case of the acid used in the cleaning solution for the Oxidden coating with metals, the objects layer removal, it can be in a rotating drum or the like, the solid medium can be a mineral acid or an organic mechanically acting acid Cleaning particles and an aqueous acid act. Mineral acids have the advantage of being acidic, a surface-active agent and, if applicable, that they are relatively cheap, while degreasing and niche acids containing an inhibitor, if necessary, allow easier regulation of the process; this method is characterized by an eroding effect. To remove the oxide layer and to use an intimate mixture as a surface-active agent for the etching of 10,000 g of typical metal objects from practically equal amounts of a dispersant, an amount of acid is required that is 1 to 5 g »vertels with an HLB value greater than 17, a cleaning agent Capable of delivering 25 connectable hydrogen ions. Both monobasic and polybasic 12 to 17, an emulsifying agent with an HLB acid, can be used with an HLB value in the range of, but for the invention value in the range of 12 to 17 and for a purpose according to the invention, a Hydrogen ion viewed as a "crosslinking agent with an HLB value in the addable range" when used for dissociation from 1 to 5. 30 of this hydrogen ion valid ionization constant

To carry out this method, an at least 10- ⁶ is. In order to reduce the hydrogen embrittlement surface-active cleaning compound to a minimum, it is further characterized in that the compound prefers the incorporation of an inhibitor which is able to inhibit the hydrogen embrittlement essentially from a water-soluble mixture. Whether an acid with a dissociation constant greater than 35 inhibitor ^{is effective or not in connection with the one used as 10 - 6} for the purpose of delivering 1 to 5 parts by weight of specific acid, can be determined by known methods an acid-stable surface, as in the example below is an area-active system, which is explained in practice. .

40 In general, the surface can be composed of equal parts of the following components: a dispersant with an HLB active agent required range of properties A value greater than 17, a detergent can best be achieved by using different types of detergent HLB value in the range from 12 to 17, surface-active agents mixed with one another, which in f Γ) Sufficient emulsifier to make 150 parts by weight of oil similar in ionic nature but different "" "emulsify, the emulsifying agent having an HLB-45 surface-active property. A be value in the range of 12 to 17, and a known method of classifying surface wetting agents for ferrous metals with an HLB active agent consists in determining the Ver value from 1 to 5. ratio between your hydrophilic and yours

The metal objects to be cleaned are given in lipophilic properties, according to the English leg container (which is the 5 ° drawing "hydrophilic lipophile balance" under the same drum as in mechanical plating, known as the abbreviation "HLB value". This can be) , and it will be a relatively trial and error procedure which describes in detail small amounts of aqueous cleaning solution, added William C. Griff in (see, for example, Journal of the cited ingredients, the Society of Cosmetic Chemists, Vol . I, 1949, p. The objects and the solution are discussed for as long as 55 to 326, and Vol. V, 1954, pp. 249 to 256) are moved or stirred until the objects have been cleaned. A somewhat more theoretical method, after which the cleaning solution is drained, is to determine the value Φ, ·, the interweaving of the cleaned, degreased, freed from the oxide ratio of the oil volume to the water volume at the layer, soiled and etched reversal point between oil -in-water and water-in-oil items remain ready for plating. With ^{the help of sixty} emulsions and the graphic determination of what would be beneficial in an immersion cleaning process - HLB value (cf. JT D a vies and EK Ride al, economically unacceptable) - carried out with the help of known companies discarding the cleaning solution used Contamination- "Interfacial Phenomena", 1961, Academic Press, avoided and quality control- New York and London, pp. 378 to 383). eases. For the cleaning of metal objects ⁶ 5 surface-active agents are compounds which, with the aid of the method according to the invention, have a hydrophilic part and a hydrophobic or novel metal cleaning compound, have lipophilic part, so that, in other words, they consist of a combination of components the HLB value on the ratio between

refers to the hydrophilic and lipophilic groups in the molecule. Surfactants in which the predominant lipophilic groups are oil-soluble and therefore extremely effective for wetting surfaces, those with inorganic substances, such as. B. with oils, are contaminated; such surfactants Means have an HLB of 5 or less. Surfactants that are about the same number contain hydrophilic and lipophilic groups

drive described for their manufacture. Unless otherwise stated, all parts are parts by weight.

example

Hydrogen embrittlement inhibitor

32.0 parts of a water-soluble polyoxyethylene glycol are added to 50.2 parts of deionized water. The mixture is heated ^{to 50 0 C}

Heat and hold an HLB value within the approximate range io until it ranges from 12 to 17 and act as detergents when all of the polyoxyethylene glycol has dissolved and one of its molecular weight is relatively low and has formed a uniform solution. The temperature as an emulsifier, when its molecular weight is reduced, then reduced to 25 ° C, whereupon 4.8 parts is relatively high. Surfactants, in concentrated hydrochloric acid, 6.5 parts of o-toluidine and which predominate the hydrophilic groups, have 15 6.5 parts of 37% formaldehyde added, an HLB value of over 17 and act as a disperser and the reaction vessel is closed . When the exothermic reaction has ended for carbonaceous and other such lubricants, the substances will be. Destiny heated briefly to 50 ⁰ C to 3O ⁰ C-abge According to the invention cools a mixture of surface and withdrawn from the container. This mass used surfactants. One of these upper 20 is referred to hereafter as "mass A", surface-active agent - a wetting agent that contains oil and

Making the metal cleaning compound The following ingredients are put into a kettle

Dissolves dirt and supports the acid in evenly touching the metal oxide layer

an HLB value within the range of 1 to 5 .... - ,,,

Another surfactant - given a clean 25 ^{made of stainless steel} :

agent that helps suspend dirt and oxide layer components - has one HLB value within the range of 12 to 17; and a third surfactant - a

medium with an average molecular weight of about 2900, of which the Polyoxypropylene core 1750, and

an HLB value of about 12 1.8

Liquid wetting and antifoaming agent with an average molecular weight of 3500, of which the polyoxypropylene core makes up about 3250, and an HLB value of about 1 1.8

70% glycolic acid 84.4

Heat and acid-resistant, non-toxic, non-ionic surfactants with a hy-

Emulsifier that emulsifies residual oils - has 30 drophobic polyoxypropylene core and two hyebenfells an HLB value within the range of drophilic polyoxyethylene chains from 12 to 17 on. Furthermore, a fourth superfluous carbon dirt removal

Surface active agent - a dispersant that prevents the agglomeration and redeposition of the Prevents particles and has an HLB value above 17 - present.

As explained in the preceding paragraph, the cleaning composition according to the invention must have an emulsifying capacity own. The objects to be cleaned are often treated in a very oily condition supplies. 10,000 g of metal objects can e.g. B. 150 g or more of oil. A convenient option To predict the emulsifying power of an Es, stirring is started, and the following surface-active By means of the determinant there is normally solid surface-active involvement of the value Φ, - (and from this the HLB value) 45 tel are added in molten form: with the aid of an emulsifying machine of the type described on p. 378 and f. of the above-mentioned book by D a vie s and ride al is described. In this machine, ligroin and water are flow metered pumped in from separate storage containers at controlled speeds and between two shear plates made of polymethyl methacrylate inserted. A stream of the emulsion hits a window made of polymethyl methacrylate, and a continuous white film appears when the oil phase con- 55

is continuous or white drops appear. Mixing continues until the solution is dissolved

when the water phase is continuous. A precise is uniform. At this point it will be 4.4 This method for determining the reversal point slowly added parts of the "mass A". The mismatch in the measurement of the conductivity of the emul- see is continued until the solution is complete sion that is uniform with the transition from the water-in-oil system 60. The final mass has a specific to the oil-in-water system decreases sharply and the weight of 1.23 increases.

reverses at the transition from the oil-in-water system to The cleaning compound described is for the

Water-in-oil system rises steeply. The most fluid metal cleaning operations at extremely high speeds are set so that the oil can be used. Although metal objects in terms of water ratio at the phase reversal point, ie the 65 their surface area and the amount that is obtained to value 0 _h . their oxide layer can vary,

To further explain the invention, and although such items are often not fully following a cleaning compound and the mind are contaminated with oil, the above is

Detergents with an average molecular weight of about 4500, of which the core is about 2250, and

with an HLB value of about 20 1.8

Emulsifiers having an average molecular weight of about 5500, of which the core is about 3250, and with an HLB of about 17 1.8

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written cleaning compound but for cleaning hose clamps were as described above

operations under the most difficult conditions, cleans, covered with a copper anchoring coating

which are conceivable, suitable. ' see and immediately mechanically, plated with zinc.

With the aid of the novel method of the invention 4 hours after plating, fifty of the can be carried out a simultaneous mechanical and marriage clamping on a test rod with a Dürchmesmischen cleaning of metal objects carried out of 2.421 cm, within ren, the following should be coated. The 24 hours none of the clamps broke. 24 hours objects are in 'an aqueous oxide layer - after plating, the other 100 Klementf ernungs- and degreasing liquid were brought, the men attached to the test rod; in turn, vigorously stirred. is moved, no breakage of any of the objects to loosen the oxide layer and clamps in for io half of 24 hours. ....:. _.....- of the oil, mechanically .'cleaned. According to Verr The above example is of course only used to complete the cleaning process. Against the explanation, and there were numerous intervals flushed and then: how. desired overdrawn, changes made. Zürn example of the cleaning and. is $ puiyorgang, within easy i ^ numerous other acids-harvester mixtures example, in an inclined rotating drum with qffeneih of acids - used werden.-Mineralsäüre'n, by the end, the wobfei While abi 'rotation as sulfur and. - Phosphoric acid,. are strong and the drum entering. The objects are relatively cheap and offer obvious on each other and on dio. Walls of the drum economic advantages ". Since such mineral acids for loosening" the oil, the oil and the Io in concentrated form serve even very permanent over-dirt, ydmit ^ deri, metal objects, surface-active Attack agent, .is ^; it is often too contaminated. The mechanical V ^ cleaning can be advantages 'that make the acid and the other components more effective, "wetfri'one"'ofthe-' loading to the Time of cleaning to be added separately; small particles or impact media incorporated. In general, the use of the

In a typical cleaning operation, as stronger inorganic acids, a quick dissolving of 170 liters of metal objects to be cleaned in a solution of the metal, and often - especially obliquely attached octagonal 760-liter rotating tubs - for steel objects with a high carbon content. Then 3 liters or heat-treated steel objects are put into the drum - using the cleaning solution of the above example, 115 liters of carbon dirt remains on the surface. Water and 170 liters of impact media (such as a 30 These phenomena can be prevented by adding a mixture of glass beads, 90% of which contain a small amount of one or more soluble salts, average diameter from 0.30 to such. the sulfates of tin, lead, cadmium, 0.56 mm and 10% have a diameter of 0.15 to be tempered to mercury etc. It is given below the -0.18 mm). Fresh conditions are then made to ensure that the vapor is introduced to bring the feed to nearly 35mixing of the surfactants at a dispersing temperature of -100 ° C, and the drum is set in the agent for carbon soiling, ie a surface clearing . After about 15 minutes of operation, active agent with a high HLB value will be included. The drum is turned to the rinsing position and rotating. The dispersant with a high HLB value settles calmly, while rinse water strongly reduces the formation of "carbon dirt" without interruption. 5 minutes at a rate of about 45 Li-40 phosphoric acid offers - as is known - special tern per minute is supplied. The excess benefits, if the surface to be cleaned of liquid is then decanted, and it is finally to be provided with a coat of paint. - if the mechanical plating is to be carried out in the same way, it is convenient to drum the acidic salts - a usual one of mineral acids (such as sodium bisulfate or anchoring solution (such as a copper-based 45 monobasic sodium phosphate) or Salts to dissolve) and a charge for mechanical turning, which are introduced one after the other to form "available" what-plating. If the hydrogen ions hydrolyze (such as painted aluminum-cleaned objects, electroplated chloride or ammonium sulfate),
or are to be coated in some other way. Many other organic acids, namely they are both screened off by the impact media and transported to the monobasic as well as the polybasic, can be transported to the next treatment station. be det. For example, tartaric acid, citric

In a test (cf. Society of Autoenenic Acid, Diglycolic Acid, Chlorosulfonic Acid, Ameisenmotive Engineering Test Procedure SAE 1065-1080) acid, acetic acid and mono-, di- or trichloro are used to determine the acetic acid produced by cleaning. In the calculation of the called hydrogen embrittlement is a standard 55 available hydrogen ions, which provide an acid dard spring wire hose clamp made of steel, may be only those acid residues with a Dishohem carbon content, the ciation constant a Rockwell C hardness of at least 10. ⁶ considered effective of at least 53, cleaned, plated and sampled. Acids that may be viewed as too weak after a given length of time with a get higher potency Standard instrument pulled apart and above 60 at the preferred elevated cleaning temperature, a stick pulled which has a slightly larger through-glycolic acid has the advantage of being a Has commesser than the inner diameter of the plexifying agent. If that continues to be for the clamp. If water used for cleaning in the hose clamp contains ions which have caused hydrogen embrittlement, the cleaning effect will be disrupted, the glycolic acid in the hose clamp helps bind these ions either immediately or within 24 hours by forming complexes that break. In general, if an acid is used, which does not have this characteristic of fracture, the shorter the time period, the greater the addition of a complex balance before the test. If you want a total of 150 No. 15 remedies, others may

acid-resistant complexing agents are added. So can the sodium salt of diethylenetriaminepentaacetic acid be used.

With the surfactants of the above Example can - due to their constancy, their chemical similarity and their physical properties work in an excellent way. The mixture of surfactants in the cleaning solution described can, however contain all acid-resistant substances with a suitable HLB value that have the following ionic. Have nature: all anionic; a mixture of anionic and non-ionic; all non-ionic; a mixture of nonionic and cationic; or all cationic. Surface active Amides derived from oils, e.g. coconut oil amide modified with ethylene oxide, or hydrogenated TaIgamide modified with ethylene oxide are adsorbed on metal surfaces and help with the otherwise difficult cleaning of Metal objects that have a thin, firmly adsorbed film, such as B. from a sulfonated oil, exhibit. ..'...

A number of substances have been empirically proven to inhibit hydrogen embrittlement proved suitable. The "mass A" described in connection with the example above contains a Combination of substances that are individually effective in this regard. Both the polyoxyethylene glycol as. the o-toluidine are also able to to reduce or suppress hydrogen embrittlement even at high temperatures. In the

ίο. »Mass Ä«, some of these substances have been reacted with one another, resulting in an adduct of o-toluidine and formaldehyde, which is stable and has an excellent inhibiting effect. In practice, however, a wide variety of commercially available inhibitors, such as ethylene oxide modified tree resin amine, 2-hexyn-3-ol, substituted thioureas, and most amines, or proteins, can be used with at least some degree of success. Are inhibitors

ao, however, at least to some extent selective, and a given inhibitor can be used in conjunction Be more effective with one acid than with another.

Claims (4)

1 2 the objects are first to remove patent claims: cleaned of metal oxide, oil and dirt, etched and then together with finely divided metal powder, 1. Process for the purification of metal against a promoter chemical and, in general, stands for subsequent coating with Me- 5 impact or impact media in a plating drum falling, moving the objects in a rotating manner, the metal powders become Drum or the like, the solid mechanically we- particles flatten against the surface of the objects Cleaning particles and an aqueous acidic, pressed and form a coherent a surfactant and optionally a coating. Though mechanical plating legs Inhibitor-containing degreasing and io quem and requires little work Contains oxide film removal solution, treated to clean surfaces prior to plating, characterized in that ren required device an inadequate as a surface-active agent, an intimate mixture, a large proportion of the available in the plants Taken from practically equal amounts of a dispersing space. means with an HLB value greater than 17, a 15 For many years it has been common practice to use metal surfaces Detergent with an HLB value in the process with the help of a number of stages, range from 12 to 17 to purify an emulsifier with batch process, an HLB value in the range of 12 to 17 and The items to be cleaned are initially a wetting agent with an HLB value to remove oil and organic contaminants Range from 1 to 5 is used. 20 greases, which can be done either with the help of 2. Surface-active cleaning composition for chloroethylene vapor or by immersion in an implementation of the method according to claim 1, container happens which contains an alkali solution. The characterized in that the mass in the we- defatted objects are then removed from a water-soluble mixture, rinsed in a second container, removed from an acid with a dissociation constant 25, derusted or their oxide coating greater than 10 - ⁶ for the purpose of delivery of 1 until free, pickled by treatment with an acid, 5 parts by weight of hydrogen ions per 10,000 parts by dipping into a third container by weight of metal objects and one happens, removed and rinsed again, which consists of an acid-stable surface-active system, often done in a fourth container is made up of practically equal parts of the fol- lowing 30. The containers occupy a considerable amount of constituent parts: a space, which inevitably increases the cost of the dispersant having an HLB greater than process. In this manner of 17, a cleaning agent with an HLB value cleaning, constant monitoring of the emulsifying strength and contamination of the treatment baths medium in the range from 12 to 17 is sufficient to emulsify 150 parts by weight of oil, 35 and The open containers represent an HLB value in which the emulsifier represents a serious hazard to workers. If it has a range of 12 to 17, and a further high carbon steels or wetting agents for ferrous metals with an HLB value - inappropriately degreased metal objects pickled value from 1 to 5. leave the ones used for pickling 3. Cleaning composition according to claim 2, characterized 40 inorganic acids often a carbon, that the wetting agent from dirt on the metal surface, whereby the Ereinem ethylene oxide-modified grease or oil targeting an even · coating with the amide such as coconut oil amide or hydrogenated coating material becomes extremely difficult. Farther Tallow amide. gets through that done with the acids 4. Cleaning compound according to claim 2 or 3, 45 pickling hydrogen in the metal grid, whereby the characterized in that each of the constituent metals becomes more brittle (this phenomenon is called parts of the surface-active system are called hy- »hydrogen embrittlement«), which often leads to Drophobic polyoxypropylene core, which breaks the cleaned and then elekdurch Graft copolymerization obtained hydro-plated metal article leads. wears drophile polyoxyethylene chains. 50 From the German patent specification 621732 is a Process for polishing small metal parts knows, in which the degreasing and removal of the Metal oxides in one operation and in a container rotating around its axis by means of such The invention relates to a method for cleaning 55 baths, which draw a water-insoluble metal objects to the subsequent over- or -sparingly soluble solvent and a drag with metals, the objects in an acid-resistant capillary-active substance, rotating drum or the like solid mechanically Specifically, these aqueous solvents contain cleaning particles and an aqueous, acidic, potassium hydrogen sulfate, pine oil and sulfonate of fatty surfactant and optionally ⁶ ° alcohols. degreasing and oxide containing an inhibitor The use of solid mechanically acting, contains delamination solution, d. H. abrasive cleaning compounds are general as well as a surface-active cleaning compound known and customary (see, for example, »GaI series of publications this procedure. vanotechnik ", Vol. 7," Metal cleaning and cutting in recent years, mechanical plating "[A. Pollack and P. Westphal], 1961, use electroplating in many areas (p. 81, etc.). urges, especially in the case of relatively small Metal objects. For mechanical plating, better one-step process to complete