EP1191095B1 - Method for cleaning objects and cleaning fluid - Google Patents

Description

The present invention relates to a method for cleaning objects and Materials made of metal, glass, ceramics, plastic (s) or composites thereof or Textiles. The invention further relates to a cleaning liquid

Cleaning processes in which a liquid is produced by heating a cleaning-active liquid Steam is brought into contact with the objects to be cleaned Use in cleaning a wide variety of objects such as metallic objects, industrially manufactured items, such as printed circuit boards, clothing, etc. of unwanted contaminants such as greases, lapping and polishing pastes, soldering pastes, adhesives, Mixtures of inorganic (e.g. salt-like) and organic (e.g. dirt, etc. from fat residues. Typically, up to Chlorinated hydrocarbons have recently been used for such cleaning tasks. This are now due to their lack of environmental compatibility, especially because of their Ozone depletion potential, their carcinogenicity and their toxic effects prohibited or at least can only be used under very strict conditions. An advantage of using chlorinated Hydrocarbons were found to be at commonly occurring temperatures have no flash point. Because of the above disadvantages, they have been replaced by others Hydrocarbons or solvents such as polypropylene glycol ether, alcohols, acetone etc. These have a flash point in the range of normally occurring temperatures and are therefore at risk of inflammation. They also have a disadvantage in that They hardly remove pigment dirt or dirt with ionic salts as these solvents Due to their ionic character, pigments or salts are very difficult to dissolve.

EP-A-47 55 96 A1 describes a cleaning method in which to be cleaned Items with a non-halogenated organic solvent, the one contains hydrogenated or dehydrogenated analogue of terpene, for example at 35 ° C in Be brought into contact. The residue left on the cleaned items Solvent contamination is removed by the cleaned items at elevated Temperature with an aqueous medium and / or a low boiling solvent Be brought in contact with the solvent contamination as an azeotrope evaporating.

The invention has for its object to provide a cleaning method that under Achieving a good cleaning effect in environmentally friendly and the ones to be cleaned Objects can be carried out gently, in particular mixtures of inorganic and organic dirt can be removed efficiently at the same time can.

The invention is further based on the object of providing a cleaning liquid with which the method according to the invention can be carried out.

The first-mentioned object is achieved with a method having the features of patent claim 1 solved. Advantageous embodiments of the method according to the invention can be found in the Claims 2 to 6.

The second object is achieved with the features of claim 7 8 to 12 characterize advantageous further features of the cleaning liquid according to the invention.

Azeotropic preparations which can be used according to the invention as cleaning-active liquids first have the advantage that their liquid phase due to the water content pigment and dirt with ionic components, such as salts, dissolves well if the azeotropic preparation used as a cleaning active liquid in the liquid state comes into contact with the objects to be cleaned. The lipophilic groups containing Molecules of the at least one further component, which are preferably per se at ambient conditions or is also a liquid at low treatment temperatures, ensure good fat-dissolving power of the azeotropic preparation.

When the azeotropic preparation used as a cleaning active liquid is heated, go because of their azeotropic character (because of the definition of "azeotrope": see Römpps Chemie Lexikon, 9th edition (1989), page 323) both water and the other (n) Component (s) in a composition corresponding to the special azeotrope in the vapor phase over. Upon contact between the vapor of the azeotropic preparation and The objects to be cleaned are reliably cleaned and "rinsed" by everyone contamination of the objects to be cleaned removed by the cleaning process.

It is particularly advantageous that the steam is not flammable because of its high water content is. Protective measures in this regard for carrying out the inventive method Device used in the process are superfluous. The flash point of the Vapor, if such exists at all, is above that in such a cleaning process normally occurring temperatures, but at least above the boiling temperature the liquid and advantageously above about 200 ° C. A temperature above 200 ° C Flash point is particularly advantageous because of the implementation protective measures to be taken in the cleaning process are less extensive than for Use of cleaning-active liquids with lower flash points. The azeotropic Preparation can be done either on the objects to be cleaned or by lowering the Temperature are condensed to the liquid phase, so that complex measures to Protection of the atmosphere surrounding the device for carrying out the method, as they are required in conventional processes, can largely be avoided.

An additional advantage is that it is active as a cleaning agent Liquid used azeotropic preparation because of its extensive use Recondensation is hardly used. So a closed cycle can be created in which the azeotropic preparation used as a cleaning-active liquid does not have to be replenished or only in negligibly small amounts. this will additionally supported by the fact that the liquid used according to the invention as a cleaning-active liquid azeotropic preparation can be free of surfactants, which can be found in a filtration of the active cleaning liquid for dirt separation in conventional processes on the Remove filter surface and require re-sharpening for conventionally used solutions.

Surprisingly, the method according to the invention also makes complexes Types of dirt such as dried-up body fluids or other everyday occurrences Contamination caused by rain or snow Dirt etc. reliably removed from the objects to be cleaned.

The method according to the invention is not restricted to closed systems. It can for example in the form of an open steam jet cleaning.

When selecting the azeotropic preparations according to the invention used as cleaning-active liquid or the further component (s) contained therein with molecules with hydrophilic (eg -OH, -NH ₂ , -COC-, -C (= O) -C-, - C (= O) -O etc.) groups and lipophilic (e.g. CH ₂ chains or C ₁ - to C ₁₂ -alkyl- etc.) groups are in addition to the good cleaning power the following criteria in the foreground: The water content of the azeotrope from water and further component or components must be large enough that there is no flash point or the steam is not combustible. The liquid and the vapor formed from it by heating must not be toxic or ozone-depleting, nor must it pose a water hazard if the preparation accidentally gets into the environment. Water-soluble, homogeneous azeotrope-forming components or water-insoluble, heterogeneous azeotrope-forming components are suitable.

• eine azeotrope Zubereitung aus Wasser und wenigstens einer Komponente mit Molekülen mit hydrophilen und lipophilen Gruppen in einem Gewichtsverhältnis (Komponente(n) mit hydrophilen und lipophilen Gruppen) : Wasser von 0,05 bis 99,95 : 99,95 bis 0,05 bildet;
• die zu reinigenden Gegenstände wenigstens einmal mit der azeotropen Zubereitung in Kontakt bringt und die flüssige azeotrope Zubereitung einschließlich damit entfernter Verunreinigungen von den zu reinigenden Gegenständen ablaufen läßt;
• Reste der azeotropen Zubereitung auf bzw. in den zu reinigenden Gegenständen durch Verdampfen entfernt; und
• den Dampf der azeotropen Zubereitung kondensiert und die durch Kondensation zurückgewonnene azeotrope Zubereitung für einen erneuten Reinigungsschritt verwendet.

In one embodiment, a method for cleaning objects comprises the steps of:

• forms an azeotropic preparation of water and at least one component with molecules with hydrophilic and lipophilic groups in a weight ratio (component (s) with hydrophilic and lipophilic groups): water from 0.05 to 99.95: 99.95 to 0.05;
• brings the objects to be cleaned into contact with the azeotropic preparation at least once and allows the liquid azeotropic preparation including the contaminants removed therefrom to run off from the objects to be cleaned;
• Residues of the azeotropic preparation on or in the objects to be cleaned are removed by evaporation; and
• the vapor of the azeotropic preparation is condensed and the azeotropic preparation recovered by condensation is used for a renewed cleaning step.

It corresponds to a particularly preferred embodiment of the Process, the objects to be cleaned at least once with a vapor of the azeotropic Preparation contact and steam during the duration of the contact allow the azeotropic preparation to condense on the objects to be cleaned. For example, the objects to be cleaned can be used once or several times the liquid azeotropic preparation is brought into contact, for example by immersion, Spraying, sprinkling or comparable, known per se from the prior art Liquid loading procedure. Then you can clean them Objects with the azeotropic preparation in the form of their vapor once or also be brought into contact several times. The azeotropic vapor condenses regularly Preparation on the objects to be cleaned and tears off residues the contaminants removed with the objects to be cleaned. Alternatively, however the procedure be carried out in such a way that the cleaning objects at least once, but preferably several times, with one Contact vapor of the azeotropic preparation. The steam also condenses here for the duration of the contact on the objects to be cleaned and thereby removes the Impurities.

According to a particularly preferred embodiment of the method, an azeotropic Preparation from water and at least one component with molecules with hydrophilic and lipophilic groups used in which the weight ratio (component (s) with hydrophilic and lipophilic groups): water in the range of 1.0 to 35.0: 99.0 to 65.0 is more preferably in the range of 4.0 to 15.0: 96.0 to 85.0.

It corresponds to an embodiment of the method according to the invention, that as an active cleaning liquid an azeotropic preparation in the form of a mixture from water and at least one further component with molecules with hydrophilic and lipophilic groups are used, the further component (s) and the water in the phase transition liquid phase / vapor phase form an azeotrope and the azeotrope Azeotropic with miscibility gap at a temperature between 0 ° C and the temperature of the Phase transition is liquid phase / vapor phase at normal pressure. It was surprising found that azeotropes with mixture gaps have particularly advantageous cleaning properties exhibit. An azeotrope with a miscibility gap is particularly preferred a temperature in the range of 20 ° C and 110 ° C at normal pressure.

In the description and in the claims, the term “at normal pressure” is understood to mean an atmospheric pressure (approximately 1 atm; approximately 10 ⁵ Pa).

Without being limited to a theoretical interpretation of the invention at this point, it has been found that azeotropic preparations which act as cleaning-active liquid in the inventive methods can be used at low temperatures of for example 20 to 25 ° C are clear. In other words, the components are complete resolved into each other. At any temperature, there are defined compositional ratios of the components in the mixing phase. The separated at elevated temperature existing phases can be carried out by suitable process steps, preferably for example by sonication with ultrasound, by intensive agitation when pumping around or stirring etc., into a milky looking emulsion. This emulsion has discontinuous Droplets of the organic component (s) in a continuous aqueous Phase on. The emulsion has excellent fat-dissolving power due to its content on organic components (with molecules with lipophilic groups), but dissolves due to the continuous water phase also water-soluble, e.g. ionic, impurities, for example salts. If the temperature of the azeotropic preparation is further increased this goes into the vapor phase, in which the components in the special, for the respective azeotropic typical composition.

In view of the above criteria, some organic components are the most homogeneous Form azeotropes with water, for use as organic components in the azeotropic preparations preferred for performing the method according to the present Invention can be used. As for professionals in this technical field Easily recognizable, however, the invention is not based on the preferred azeotropes Connections limited.

• R¹ und R³ jeweils unabhängig voneinander stehen für H; geradkettige oder verzweigte gesättigte oder ungesättigte C₁- bis C₁₈- Alkylgruppen, in denen eine oder mehrere nicht benachbarte -CH₂-Gruppen durch -O- ersetzt sein können; gesättigte oder ungesättigte cyclische C₁- bis C₈- Alkylgruppen, in denen eine oder mehrere nicht benachbarte -CH₂-Gruppen durch -O- ersetzt sein können; Hydroxy; C₁- bis C₈- Alkoxy; Amino, worin ein oder beide Wasserstoff(e) durch C₁- bis C₈- Alkylgruppen ersetzt sein können; und
• X steht für -O-; -C(=O)-; -C(=O)-O-; -NH-; -NR¹-; -N(-OH)-; geradkettige oder verzweigte -(C₁- bis C₈-)Alkylengruppen, in denen eine oder mehrere nicht benachbarte -CH₂-Gruppen durch -O- ersetzt sein können; und n für ganze Zahlen von 1, 2, 3, etc. steht.

The preferred compounds can best be described by the following general formula R 1 - [X] n - R 3 wherein

• R ¹ and R ³ each independently represent H; straight-chain or branched saturated or unsaturated C ₁ to C ₁₈ alkyl groups in which one or more non-adjacent -CH ₂ groups can be replaced by -O-; saturated or unsaturated cyclic C ₁ to C ₈ alkyl groups in which one or more non-adjacent -CH ₂ groups can be replaced by -O-; hydroxy; C ₁ to C ₈ alkoxy; Amino in which one or both of the hydrogen (s) can be replaced by C ₁ to C ₈ alkyl groups; and
• X stands for -O-; -C (= O) -; -C (= O) -O-; -NH-; -NR ¹ -; -N (OH) -; straight-chain or branched - (C ₁ - to C ₈ -) alkylene groups, in which one or more non-adjacent -CH ₂ groups can be replaced by -O-; and n stands for integers of 1, 2, 3, etc.

In other words: The organic components of the azeotropic preparations that are in the the method according to the present invention can be chosen from organic compounds belonging to the groups alcohols, glycols, amines, ethers, Glycol ethers, esters, ketones and amino alcohols as well as N-heterocycles or organic acids belong.

In a particularly preferred procedure, compounds of the general formula given above are used as organic component (s) of the azeotropic preparation or as further organic component (s) in which R ¹ and R ³ each independently represent saturated or unsaturated C ₁ - bis C ₁₂ alkyl groups, even more preferably for saturated or unsaturated C ₁ to C ₈ alkyl groups, in which one or more non-adjacent CH ₂ group (s) can be replaced by -O-, for hydroxy, for C ₁ - to C ₈ alkoxy and for unsubstituted or substituted by alkyl groups amino groups; and / or X represents -O-; -C (= O) -; -C (= O) -O-; -NH-; -NR ¹ -; -N (OH) -; -OCH (R ² ) -CH ₂ - (wherein R ^{2 is} H or methyl); and n represents 1 or 2.

Specific examples of the groups represented by R ¹ and R ³ are hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, furfuryl-2, tetrahydrofuryl-2, hydroxy, methoxy, ethoxy and propoxy. Specific examples of the groups represented by X are -O-; -C (= O) -; -C (= O) -O-; -NH-; -NR ¹ -; -N (OH) -; Ethyleneoxy and propyleneoxy.

• (C₁- bis C₁₂-Alkyl) - C(=O)-O - (C₁- bis C₁₂-Alkyl);
• (C₁- bis C₁₂-Alkyl) - O - (C₁- bis C₁₂-Alkyl);
• (C₁- bis C₁₂-Alkyl) - C(=O) - (C₁- bis C₁₂-Alkyl);
• (C₁- bis C₁₂-Alkyl) - [N - (H oder C₁- bis C₁₂-Alkyl) (H oder C₁- bis C₁₂-Alkyl)];
• HO-(CH₂)_1,2,...,etc. - [NH₂ oder NH(C₁- bis C₁₂-Alkyl) oder N(C₁- bis C₁₂-Alkyl)₂];
• H - [O - CH(H oder CH₃) - CH₂]_{1,2, ... etc.} - OH; und
• (H oder C₁- bis C₁₂-Alkyl) - [O - CH(H oder CH₃) - CH₂]_{1, 2,... etc.} - [OH oder O(C₁bis C₁₂-Alkyl)].

Even more preferred methods according to the invention use compounds of the general formula given above as organic component (s) of the azeotropic preparations or as further organic component (s) which are selected from the group

• (C ₁ to C ₁₂ alkyl) - C (= O) -O - (C ₁ to C ₁₂ alkyl);
• (C ₁ to C ₁₂ alkyl) - O - (C ₁ to C ₁₂ alkyl);
• (C ₁ to C ₁₂ alkyl) - C (= O) - (C ₁ to C ₁₂ alkyl);
• (C ₁ to C ₁₂ alkyl) - [N - (H or C ₁ to C ₁₂ alkyl) (H or C ₁ to C ₁₂ alkyl)];
• HO- (CH ₂ ) _{1,2, ..., etc.} - [NH ₂ or NH (C ₁ to C ₁₂ alkyl) or N (C ₁ to C ₁₂ alkyl) ₂ ];
• H - [O - CH (H or CH ₃ ) - CH ₂ ] _{1,2, ... etc.} - OH; and
• (H or C ₁ to C ₁₂ alkyl) - [O - CH (H or CH ₃ ) - CH ₂ ] _{1, 2, ... etc.} - [OH or O (C ₁ to C ₁₂ alkyl) ].

Specific examples of organic components that are used alone or in groups of several mentioned compounds together in azeotropic preparations of the cleaning active Liquid that can be used are selected from propylene glycol ether; dipropylene glycol monomethyl ether; Dipropylene glycol mono-n-propyl ether; tripropylene; 3-methoxy-3-methylbutanol; furfuryl alcohol; tetrahydrofurfuryl; 1-aminobutanol-2; monoisopropanolamine; 2-amino-2-methylpropanol-1; 2-amino-2-methyl propanediol-1,3; 3- (aminomethyl) pyridine; Ethanolamine; furfuryl; methyl; isopropyl; aminoacetaldehyde; 4-aminomorpholine; 1-methylimidazole; 1,2-dimethylimidazole; 1-vinylimidazole; 1,4-diazabicyclo [2.2.2] octane (DABCO); 1,5-diazabicyclo [4.3.0] non-5-ene; and 1,8-diazabicyclo [5.4.0] undec-7-ene.

It corresponds to a further, likewise preferred embodiment that the cleaning-active At least one liquid for the process according to the invention is not self-evaporating cleaning booster. This should preferably be distill with the azeotropic preparation. Such cleaning evaporators which do not evaporate independently are known to the person skilled in the art from the prior art and therefore require no further listing at this point.

It is also preferred according to the invention that the cleaning-active liquid has at least one Add corrosion protection additive. This should preferably be with the azeotropic one Distill the preparation. Such anti-corrosion additives are particularly advantageous if objects made of non-ferrous metals or light metals are to be cleaned. For example aluminum parts can be cleaned excellently with an azeotropic preparation, which includes 1-methylimidazole. This acts as an inhibitor. Cleaning parts out Copper can also advantageously with azeotropes comprising 1-methylimidazole Preparations are carried out. This lightens the surface. Instead of The above compound can also other corrosion protection additives and inhibitors are added, as known to the person skilled in the art from the prior art are.

Methods for cleaning are particularly preferred because they lead to excellent cleaning results Cleaning of objects according to the invention, in which one is used as a cleaning-active liquid an azeotropic preparation of water and an organic component is used. In this case, the organic component is preferably a compound that is selected is from the group dipropylene glycol monomethyl ether; Dipropylene glycol mono-n-propyl ether; tripropylene; 3-methoxy-3-methylbutanoi; furfuryl alcohol; tetrahydrofurfuryl; 1-aminobutanol-2; furfuryl; Methyl lactate and isopropyl lactate.

(A) Glykolether:

• organische Komponente Nr. 1: Dipropylenglykolmonomethylether R¹ = CH₃; R³ = OH; X = OCH₂-CH(CH₃)-; n = 2;
• organische Komponente Nr. 2: Tripropylenglykolmonomethylether R¹ = CH₃; R³ = OH; X = OCH₂-CH(CH₃)-; n = 3;
• organische Komponente Nr. 3: 3-Methoxy-3-methylbutanol R¹ = CH₃; X = O-C(CH₃)₂-(CH₂)₂-; n = 1;
• orgaische Komponente Nr. 4: Dipropylenglykol-n-propylether R¹ = n-C₃H₇; R³ = OH; X = OCH₂-CH(CH₃)-; n = 2;

(B) Alkohole:

• organische Komponente Nr. 5: Furfurylalkohol R¹ = Furfuryl-2; X = O; R³ = H; n = 1;
• organische Komponente Nr. 5: Tetrahydrofurfurylalkohol R¹ = Tetrahydrofurfuryl-2; X = O; R³ = H; n = 1;

(C) Amine:

• organische Komponente Nr. 7: 1-Aminobutanol-2 R¹ = OH; X = sec-Butyl; R³ = NH₂; n = 1;
• organische Komponente Nr. 8: Furfurylamin R¹ = Furfuryl-2; X = -NH-; R³ = H; n = 1;
• organische Komponente Nr. 11: 2-Amino-2-methylpropanol-1 R¹ = CH₃; X = CH₃ - C - CH₂OH; R³ = -NH₂; n = 1;
• organische Komponente Nr. 12: 2-Amino-2-methylpropandiol-1,3 R¹ = HOCH_2-; X = CH₃ - C - CH₂OH; R³ = -NH₂; n = 1;

(D) Ester:

• organische Komponente Nr. 9: Methyllactat R¹ = Hydroxyethyl; X = C(=O)O-; R³ = CH₃; n = 1;
• organische Komponente Nr. 10: Isopropyllactat R¹ = Hydroxyethyl; X = C(=O)O-; R³ = i-C₃H₇; n = 1;

The compounds mentioned belong to the following groups of compounds of the general formula R ¹ - [X] _n - R ³

(A) glycol ether:

• organic component no. 1: dipropylene glycol monomethyl ether R ¹ = CH ₃ ; R ³ = OH; X = OCH ₂ -CH (CH ₃ ) -; n = 2;
• organic component no. 2: tripropylene glycol monomethyl ether R ¹ = CH ₃ ; R ³ = OH; X = OCH ₂ -CH (CH ₃ ) -; n = 3;
• Organic Component No. 3: 3-methoxy-3-methylbutanol R ¹ = CH ₃ ; X = OC (CH ₃ ) ₂ - (CH ₂ ) ₂ -; n = 1;
• organic component no. 4: dipropylene glycol n-propyl ether R ¹ = nC ₃ H ₇ ; R ³ = OH; X = OCH ₂ -CH (CH ₃ ) -; n = 2;

(B) alcohols:

• organic component no. 5: furfuryl alcohol R ¹ = furfuryl-2; X = O; R ³ = H; n = 1;
• Organic Component No. 5: tetrahydrofurfuryl alcohol R ¹ = tetrahydrofurfuryl-2; X = O; R ³ = H; n = 1;

(C) amines:

• organic component no. 7: 1-aminobutanol-2 R ¹ = OH; X = sec-butyl; R ³ = NH ₂ ; n = 1;
• organic component no. 8: furfurylamine R ¹ = furfuryl-2; X = -NH-; R ³ = H; n = 1;
• organic component no. 11: 2-amino-2-methylpropanol-1 R ¹ = CH ₃ ; X = CH ₃ - C - CH ₂ OH; R ³ = -NH ₂ ; n = 1;
• organic component no. 12: 2-amino-2-methylpropanediol-1,3 R ¹ = HOCH _2- ; X = CH ₃ - C - CH ₂ OH; R ³ = -NH ₂ ; n = 1;

(D) ester:

• Organic Component No. 9: methyl lactate R ¹ = hydroxyethyl; X = C (= O) O-; R ³ = CH ₃ ; n = 1;
• Organic Component No. 10: isopropyl lactate R ¹ = hydroxyethyl; X = C (= O) O-; R ³ = iC ₃ H ₇ ; n = 1;

In such to be used as cleaning-active liquid in the method according to the invention Azeotropic preparations are water and an organic component in relative terms Amounts of (100 - x)% by weight: x% by weight. X is in the range of 0 <x 35 35, preferably in the range 3 ≤ x besonders 25, particularly preferably in the range 4 ≤ x ≤ 15.

In a further preferred method, the mixing ratio of water is set and the further component (s) in the azeotropic preparation essentially on the Ratio present in the vapor coming from the liquid azeotropic preparation arises when heated.

According to a further, likewise preferred embodiment, the invention comprises Process for cleaning objects the step that one as cleaning-active Liquid uses an azeotropic preparation of water and two organic components. An azeotropic preparation is particularly preferred as the cleaning-active liquid from water, dipropylene glycol mono-n-propyl ether and another organic component used. Of course, others can also be used in this embodiment Components in the azeotropic preparation used as a cleaning active liquid be included, for example at least one which is not self-evaporating, particularly preferred with the azeotropic preparation of distilling cleaning boosters as such is known from the prior art and has already been mentioned above, and / or at least one (with particular preference distilling with the azeotropic preparation) corrosion protection additive or corrosion protection inhibitor, as it also as such or such is known from the prior art and has already been mentioned above.

According to this preferred embodiment, it is particularly preferably used as another organic component a compound from the group 1-aminobutanol-2; monoisopropanolamine; 2-amino-2-methylpropanol-1; 2-amino-2-methyl propanediol-1,3; 3- (aminomethyl) pyridine; Ethanolamine; aminoacetaldehyde; 4-aminomorpholine; 1-methylimidazole; 1,2-dimethylimidazole; 1-vinylimidazole; 1,4-diazabicyclo [2.2.2] octane (DABCO); 1,5-diazabicyclo [4.3.0] non-5-ene; and 1,8-diazabicyclo [5.4.0] undec-7-ene.

The organic compounds mentioned can be used alone or in combination with one another be used.

It is also particularly preferred that a further organic component from the Group used acetic acid, hydroxyacetic acid, formic acid and butyric acid. Also the mentioned acids can be used alone or in combination with one another or with others, for example the organic components mentioned above can be used.

According to the preferred embodiment described above, the cleaning active is used Liquid an azeotropic preparation of water, a glycol ether (preferred Dipropylenglykolmono-n-propylether) and another organic component in relative amounts of 90% by weight: (10 - y)% by weight y% by weight, where y is in the range of 0 <y 5 5, particularly preferably in the range from 0 <y 2 2.

A device in which the method according to the invention can be carried out is shown in the attached figure shows schematically: a storage tank 2 with a separation chamber 4 and an overflow chamber 6 is connected via a feed pump 8 and a heating device 10 a cleaning device 12 connected. The interior of the structure known per se Cleaning device, which contain cleaning nozzles, a rotating basket, etc. can, in the example shown in the figure, is connected to a pressure compensation vessel 14, however, this is not essential for the function.

A line leads from the bottom of the cleaning device 12 to a filter device 16. The filter device 16 is connected via a line with a feed pump 18 to the top the separation chamber 4 connected. Another line leads from the filter device 16 via a vacuum pump 20 through a condenser 22 and a cooler 24 back to Separation chamber 4.

Furthermore, a line leads from the overflow chamber 6 via a feed pump 26 through a Heat exchanger 28 into a distillation device 30 and from there into the cleaning device 12 or back to the storage tank 2.

In the storage tank 2, a feed line 32 leads to loading the storage tank 2 with cleaning-active Liquid. The storage tank 2 further contains a device, not shown for removing sludge that settles in the separation chamber 4.

A ventilation line leads into the normally tightly sealed cleaning device 12 34th

The structure of the individual components of the cleaning device 12 described Electrical control of the individual assemblies (not shown) is known per se and are therefore not described in detail.

The function of the device described is as follows: after loading the cleaning device 12 with goods to be cleaned is carried out in an exemplary but not restrictive manner Embodiment first a liquid cleaning, in which the feed pump 8 is put into operation and cleaning-active liquid, which may be in the heating device 10 can be tempered, the cleaning device 12 is supplied. In the Cleaning device 12 is an immersion bath of the rotating items to be cleaned and / or spraying the items to be cleaned with liquid. The liquid is pumped through the feed pump 18 withdrawn from the cleaning device 12 through the filter device 16 and the separation chamber 4 fed. The filter device 16 predominantly settles inorganic dirt that is drawn off. In the separation chamber 4 settles mainly greasy dirt, which is also removed.

The liquid cleaning stage described by way of example is followed by rinsing under the same conditions with active cleaning liquid from the tank 6.

This is followed by a steam cleaning stage or steam rinsing stage in which the feed pump 26 is put into operation so that the cleaning-active liquid in the distillation device 30 heated and converted into steam. Due to the azeotropic character the vapor used in the azeotropic preparation used as a cleaning active liquid a predetermined content of water and the further component or the others Components. The liquid azeotropic preparation is preferably already made of it Components put together, as does the content of the corresponding components in the vapor phase. The steam arrives in the cleaning device 12 in intensive contact with the material to be cleaned, taking at least part of the steam condensed. The condensate is removed by means of the feed pump 18 after flowing through the filter device 16 fed to the deposition chamber.

When the steam from the distiller 30 through the condenser 22 and the cooler 24 is returned to the storage tank 6, the liquid can be processed.

Convection drying advantageously follows steam cleaning or steam rinsing or vacuum drying. In this case, 12 steam is sucked off by means of the vacuum pump 20, whereby in the cleaning device 12 forming condensate flows through the filter device 16. The one with the condensate is mixed with steam after flowing through the condenser 22 and Cooler 24 is supplied to the storage tank 2 as liquid again.

After completion of the vacuum drying, the separation chamber 4 is on the ventilation line 34 ventilated, and the cleaned good can be removed.

In an alternative embodiment, which also leads to advantageous results the objects to be treated in the cleaning device 12 with the cleaning active Sprayed liquid used azeotropic preparation. This happens in the Way that the objects to be cleaned soak up the liquid. The subsequent ones Process steps are essentially the same as described above were.

The objects to be treated are in a much better condition after the treatment than after treatment in a conventional process, i.e. using more common organic solvent for the cleaning steps under identical conditions. In particular, it was surprisingly found that not only all organic dirt including Lipophilic or oil-like or fat-like substances is removed, but also all inorganic dirt, especially inorganic salts from sweat, color pigments etc. The treated objects have no unpleasant smell and show an excellent appearance.

As already stated above, azeotropic preparations with a miscibility gap are surprising good and conventional preparations clearly superior cleaning behavior.

In the case of the use of azeotropic preparations with a miscibility gap, in the case of Treatment in the liquid phase of the objects to be cleaned according to the invention with an azeotropic preparation brought into contact, which is in a state in which the components of the azeotropic preparation are present in separate or at least partially separate phases. For example, the liquid azeotropes present in the phase separation state Preparations treated with ultrasound or pumped intensively or stirred, see above that a milky emulsion of the azeotropic preparation forms. This emulsion dissolves not only good fatty or oily components, but also ionic or salt-like impurities.

In the case of treating the objects to be cleaned with the azeotropic preparation in the vapor phase, the azeotropic preparation - as described above - is heated, and a steam is produced in which the components are present in the proportions, which are determined by the characteristic azeotropic properties. The steam condenses at least in part on the objects to be cleaned, and it turns the same milky emulsion like in the liquid phase. In this case too it will be excellent Fat and salt dissolving power observed.

When increasing the temperature of the azeotropic preparation up to the phase transition liquid The components pass phase / vapor phase in the proportion corresponding to the azeotrope into the vapor phase, and the azeotropic preparation can be done easily Prepare by distillation.

The latter embodiment of the method is particularly advantageous for cleaning metal parts. For example, when using Excellent removal of azeotropes with a gap between lapping and polishing pastes from metal parts. For this purpose, for example, an azeotropic preparation mixed with acidic additives used as a cleaning active liquid. The cleaning is done in the above Single-chamber system and can be carried out continuously or in a batch process.

It is also surprisingly easy to use SMD adhesive (SMD = Survace Mount Devices) as they are used in the manufacture of SMD parts with double-sided Assembly is used so that the components are in place during the soldering process not solve. The adhesive is usually applied using dispenser systems or templates, before the circuit boards are attached. Misprinted / dispensed items can be cleaned Printed circuit boards or stencils. Surprisingly, with the invention used azeotropic preparations achieve cleaning results that those with significantly exceed conventional solvents such as butyl acetate or isopropanol. moreover are protective measures (e.g. against explosions in the case of those who are at risk Solvents) superfluous.

In the same way, excess soldering pastes applied in soldering are easier and environmentally friendly way of misprinted plates and stencils with the invention Remove the procedure using the azeotropic preparations mentioned. It is also possible to remove flux residues after soldering. The Cleaning takes place by spraying, spray rinsing and drying the objects to be cleaned preferably in the immersion process with ultrasound (cleaning stage), rinsing with or without Ultrasound (rinsing stage) and drying. Cleaning is preferred at one temperature performed in the range of 40 to 60 ° C, but is not on this temperature range limited. Especially when treating the objects to be cleaned in the cleaning stage with the steam of the azeotropic preparation, the temperature can be significantly higher, for example are also above 100 ° C.

Azeotropic preparations are particularly preferred for cleaning processes used according to Table I below. In this table are also the preferred ones Ratios of organic components (O.K.): water, the boiling points of each azeotropic preparation as well as the temperatures at which to be cleaned Objects with the respective azeotropic preparation are treated as examples can. Of course, the invention is not limited to the specified conditions Components and treatment temperatures limited.

If azeotropes with a mixture gap are used, three-component mixtures of water, dipropylene glycol mono-n-propyl ether and amine compounds or N-heterocyclic compounds or organic acids according to Table II below are particularly preferably used according to the invention. An exemplary, but not restrictive composition of the azeotropes is as follows: water (90% by weight), dipropylene glycol mono-n-propyl ether (10 - y% by weight), y% by weight of the compounds given in Table II. Azeotropelike preparation Boiling point (° C) Treatment temp. (° C) Organ. Component (OK) OK: water ratio No. 1 8.9: 91.1 99.2 60 No. 2 7.9: 92.1 99.1 60 No. 3 11: 89 99-101 65 No. 4 10:90 100 65 No. 5 20:80 98.5 60 No. 6 10.5: 89.5 102 65 No. 7 4.7: 95.3 102 65 No. 8th 30.9: 69.1 100 60 No. 9 20:80 99.5 60 No. 10 34: 76 98 60 No. 11 5: 95 98 65 No. 12 6.5: 93.5 101 60 Organic component y (% by weight) Boiling temperature (° C) 1-aminobutanol-2 0.3 101 monoisopropanolamine 0.8 100 2-amino-2-methyl-propanol-1 1.3 102 2-amino-2-methyl-1,3-propanediol 1.5 101 3- (aminomethyl) pyridine 0.16 101 ethanolamine 0.3 104 Aminoacetaldehyde dimethyl 2.4 101 3.4 4.2 4-aminomorpholine 0.4 101 1-methylimidazole 0.1 101 1,2-dimethylimidazole 0.1 100-102 1-vinylimidazole 0.3 101 DABCO 0.03 101-103 0.08 0.1 1,5-diazabicyclo- [4.3.0] non-5-ene 0.02 100-103 1,8-diazabicyclo- [5.4.0] undec-7-ene 0.02 101-103 Acetic acid (80%) 1.5 100-101 hydroxyacetic 0.5 100-101 formic acid 1.5 100-101 butyric 1.2 100-101

Table II also shows the boiling point (° C) of water, dipropylene glycol mono-n-propyl ether and the specified compounds formed azeotropic preparation.

Two examples are explained below, but are not limited to these to be.

example 1

The drum of the cleaning device 12 described above was also cleaned Material loaded. The material consisting of textiles was in the first step under Liquid cleaning conditions treated with azeotropic preparations at elevated temperatures. The azeotropic preparations and the respective treatment temperatures are in of Table I above. The material was azeotroped while moving in the warm Preparation immersed. The warm azeotropic preparation was in a closed Circulated from the drum of the cleaning device 12 through a filter device 16 and the separation chamber 4 fed. The filter device 16 predominantly settled inorganic dirt (salts) that has been removed. In the deposition chamber 14 mainly fatty dirt settled, which was also removed.

The first treatment step was followed by a second treatment step, which is also under Liquid treatment conditions was performed. Fresh azeotropic preparation (composition: see table I; in each run had the azeotropic preparation of the second Treatment step same composition as that of the first step) was the Drum of the cleaning device 12 fed at an elevated temperature. The material was in a second closed circuit from the drum of the cleaning device 12 fed to the separating chamber 4 via a filter device 16. The deposition of inorganic and organic substances was carried out in the same way as in the first treatment step.

The second treatment step was followed by a third treatment step, in which the one to be treated Material was treated with the steam of the respective azeotropic preparation. This had the composition typical for the respective azeotrope (see Table I). The Azeotropic preparation was made after passing the feed pump into a distiller transferred to the vapor phase. The steam was in intimate contact with the person to be treated Material brought into the drum of the cleaning device 12. At the time A portion of the vapor was condensed from contact with the material. The liquid out the cleaning step after the condensation was removed from the drum and after passing through the filter device 16 to separate the organic substances Separation chamber 4 fed where organic contaminants have been separated. The Steam that was not already condensed in the drum of the cleaning device 12, was withdrawn from the drum, condensed and (after filtration, if appropriate) fed to the storage tanks 2 for further use.

After the vapor of the azeotropic preparation was drawn off, the drum was evacuated, for example to 10 ^-2 bar, and the remaining steam was drawn off in the same manner as described above. The warm treated material released the water and the organic component of the azeotropic preparation in vacuo so that it was dry after 10 minutes of vacuum treatment.

The material to be treated was in much better condition than that of the conventional material Had been treated wisely. Both inorganic and organic contaminants were completely removed. The material had no unpleasant smell and an excellent appearance. It could be ironed or pressed with good results become.

The third step (steam treatment) is not absolutely necessary after liquid cleaning; the same results as described above were obtained even without the steam treatment achieved. It is also possible to follow the steps of the treatment of the cleaning material with liquid azeotropic preparation through treatment steps to be completely or partially replaced with vaporous azeotropic preparation. This one too The same cleaning results were achieved with the procedure.

Example 2

Misprinted printed circuit boards or stencils from SMD production were used with a Three-component mixture of water, dipropylene glycol mono-n-propyl ether or one Treated amine compound or N-heterocyclic compound or organic acids, as can be seen, for example, from Table II. The three-component mixtures that as active cleaning liquids were used, consisted of 90 wt .-% of water, too (10 - y)% by weight of dipropylene glycol mono-n-propyl ether and y% by weight of one of the Compounds listed in Table II. The cleaning was done by spraying.

The circuit boards or stencils were used to remove SMD adhesive in the table II specified boiling temperatures with the liquid azeotropic preparations below Use of ultrasound treated (however, ultrasound is not essential to achieve good cleaning results required). The azeotropic preparations were in the form of a milky emulsion that became almost clear when ultrasound was applied. There was one complete removal of the adhesive without protective devices, for example for protection before explosions, had to be provided in the system.

The cleaning results were significantly better than when using conventional solvents such as butyl acetate or isopropanol. In addition, the latter must be used for occupational safety reasons protection of the system against explosions must be provided.

Claims (12)

1. A method of cleaning an object with a cleaning-active liquid which contains more than 65% of water and at least one organic compound which upon mixing with water at the temperature prevailing in the liquid cleaning operation forms a miscibility gap.
2. A method according to claim 1 characterised in that the contact between the object to be cleaned and the cleaning-active liquid takes place under the effect of ultrasound.
3. A method according to claim 1 or claim 2 characterised in that the organic component is so selected that the miscibility gap occurs upon heating of the cleaning-active liquid.
4. A method according to claim 3 characterised by a method step-in which the vapour of the cleaning-active liquid condenses on the object to be cleaned.
5. A method according to one of claims 1 to 4 characterised in that the organic component is so selected that the cleaning-active liquid forms an azeotrope.
6. A method according to claim 5 characterised in that the cleaning-active liquid is of a composition corresponding to the vapour thereof.
7. A method according to claim 6 characterised in that the cleaning-active liquid is passed in an evaporation-condensation circuit including a filter.
8. A method according to one of claims 1 to 7 characterised in that the solvent used is an organic component of the general formula R¹ - [X]_n - R³ wherein

   R¹ and R³ each represent independently of each other H; straight-chain or branched saturated or unsaturated C₁- to C₁₈-alkyl groups in which one or more non-adjacent -CH₂- groups can be replaced by -O- ; saturated or unsaturated cyclic C₁- to C₈-alkyl groups in which one or more non-adjacent -CH₂- groups can be replaced by -O- ; hydroxy; C₁- to C₈-alkoxy; amino, wherein one or both hydrogen(s) can be replaced by C₁- to C₈-alkyl groups; and

   X stands for -O-; -C(=O)-; -C(=O)-O-; -NH-; -NR¹-; -N(OH)-; straight-chain or branched-(C₁- to C₈-alkylene groups in which one or more non-adjacent -CH₂- groups can be replaced by -O- ; and n stands for integers of 1,2,3 etc.
9. A method according to one of claims 1 to 8 characterised in that the water content of the cleaning-active liquid is > 75% by weight, preferably > 85% by weight.
10. A method according to one of claims 1 to 9 characterised in that the cleaning-active liquid contains a cleaning intensifier which does not spontaneously evaporate and/or an anti-corrosion additive.
11. A method according to one of claims 1 to 10 characterised in that besides a glycolether, preferably dipropylene glycolmono-n-propylether, the cleaning-active liquid contains a further organic component.
12. A method according to one of claims 1 to 11 characterised in that the temperature prevailing in the liquid cleaning operation is in the range of from 40 to 60°C.

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