WO1992002665A1 - Process for cleaning and degreasing, spontaneously emulsifying premix for use at the process and the resulting emultion - Google Patents

Abstract

Process for cleaning and degreasing with the aid of a water containing emultion, especially a micro emulsion. The emulsion is prepared at the site of use by the mixing of a water free or nearly water free (below 10 weight %) composition, which contains one or more nonionic tensides, one or more organic solvents and eventually one or more tensides with charge giving function and eventually electrolytes in solution or in the shape of solid state, dispersed, finely divided particles, with water and eventually solid state electrolyte, liquid electrolyte or electrolyte solution at the site of use. The invention also concerns a spontaneously emulsifying composition intended to be used at the process, the emulsion obtained and its use.

Description

Process for cleaning and degreasing, spontaneously emulsifying premix for use at the process and the resulting emulsion.

For a long time there have been automatic car cleaning

equipments which to large extent have been based upon different kombinations of brushes together with spraying of cleaning solutions, run off and polish compositions etc. The differing designs of the cars makes automatic control of the movements of the brushes very problematic and one has tried to use pressure water jets instead, which give better accessibility with respect to hardly accessible corners. For the cleaning of motors, chassis, wheel houses etc. high pressure jets are the only realistic alternative to manual washing.

With regard to heavier vehicles as trucks, lorries and busses the problem of automation of the brush movements is mainly still unsolved. If brushes are used the equipment is run manually.

High demands must be met by the person who is running the equipment. One has often found it necessary to rely upon manual washing eventually assisted with manually directed high pressure guns. The road safety and the maintenance of the vehicles, however, demands very efficient cleaning at the same time as the costs of manual cleaning accelerate. New equipments for

automatic cleaning of heavy vehicles work with ramps of high pressure jets.

Though modern high pressure jets are very efficient the

mechanichal work they are able to bring about is significantly less than what will be effected by brushes. The demand for efficient cleaning is, however, the same in both cases. The reduced mechanical work thus must be compensated by cleaning agents with higher efficiency. The agents must at the same time be mild against finishes, plastics, bright metals etc. To this is added that the wastes from the cleaning plants must be environmentally acceptable. The earlier use of huge amounts of solvents of the cold degreasing agent type is therefore no longer possible. Most manufacturers of agents intended for use at vehicle

cleaning have chosen to solve the problem by using emulsions, especially so called microemulsions, which in themselves combine the activity of a solvent of the cold degreasing agent type and a tenside mixture and make it possible to reduce the solvent quantity to a fraction of what is needed, when using a

conventional cold degreasing agent.

Emulsions and microemulsions have been used as agents for textile cleaning and for enhanched oil recovery. Most of these emulsions have been based on anionic tensides, often in

combination with nonionic tensides, especially of the etoxylated alkyl phenol type. Emulsions for cleaning purposes have been considered very critical systems with high demand for mixing exactitude not to be instabile. Therefore they have been

delivered ready-mixed with comparatively high water contents. This has caused heavy costs for transport and storage.

A system that from one or a few waterfree or low water

containing components is able to produce an emulsion and far less a microemulsion for cleaning purposes at the site of use has so far not been found.

The inventor has studied the problem carefully and thereby found that a waterfree mixture of nonionic tensides and solvents may be formulated in such a way that it becomes easily pour- and pumpable and at mixing with water spontanously forms a

microemulsion with a minimum of agitation that may be achieved by the added water either directly or via a simple propeller which is driven by the water pressure.

The emulsion formed is particularly stabile at both low and high pH and may be completed with a big number of basic, acid or neutral electrolytes, especially of the complex forming type, which make the cleaning efficiency still better.

A typical example of earlier technic regarding use of emulsions for cleaning purposes is the Swedish patent no 143534. According to this patent one uses a concentrate emulsion consisting of solvents, water and an emulsifying agent, which consists of a nitrogenholding nonionic tenside. Nothing is said about the character of the emulsion. The concentrate solution is a ready-mixed emulsion and holds 25 to 50 % water. Nothing is said about the method of making the emulsion and one may

therefore believe that conventional technic with high intensity agitation and homogenizing is used.

Another example of earlier technic is Swedish patent no 149594 The applicant is the same as the one of the patent mentioned before and it seems to be a further development of the earlier invention. It is said in the publication that emulsions

according to the earlier patent are not absolutely stabile.

According to this new invention the emulsifying agent is a combination of a nonionic tenside and an anionic tenside. As examples etoxylated fatty alkohol and derivative of sulfamide acetic acid are mentioned. The water content of the concentrate emulsion is said to be 35 to 40 %.

European patent no 52275 concerns a water in oil emulsion intended for cleaning of cars in connection with repare and refinishing jobs. The emulsion has an inner phase consisting of water and amounting to 70 to 85 % of the total composition and an outer, continous phase consisting of solvents and amounting to 10 to 25 % of the total quantity. The emulsifier consists of a nonionic tenside combination. At the preparation one makes us of the, within the emulsion technology, usual method first to prepare one water phase and one oil phase, which thereafter are mixed under carefully controlled conditions. The description of the mixing method makes clear that the composition is not emulsifying spontanously. The mixing is done, while adding the water phase successively to the oil phase, which at the same time is agitated vigorously.

The german laid open patent publication no 1206265 concerns an emulsion intended for cleaning of metal details. The production method is described briefly and is relatively complicated. To a mixture of solvents are added an amine salt of an alkyl benzen sulfonic acid and a nonionic emulsifier consisting of a

polyglykol ester of an unsaturated fatty acid. To the mixture added water while agitating. To the resulting sluggish mixture are added a neutral salt, more water and finally a short chained amine all while agitating continously. The final emulsion is completely clear and might be called a microemulsion according to the terminology used nowadays. It contains huge amounts of water. In the examples above 65 %.

The American patent no 3536529 concerns a method for removing oil remains from the walls of oil tanks. At the process a composition containing 75 to 95 % of a highly aromatic solvent and 5 to 25 % of a nonionic tenside is applied. No emulsion formation is on the whole mentioned. The composition is used full strength, injected in water in connection with spraying on or is added to a solution for dipping of oil-dirtied details. In these cases eventual instability problems may be ignored as the water seems to have solely a carrying function. Instability might even be an advantage as the intention is that the aromatic solvent and the tenside will diffuse into the oil remains and make the removal easier at the following water wash. After application the objects are left standing 15 minutes to 3 hours preferably 45 minutes to 1.5 hours before the water wash. The process is entirely aimed at the removal of oils hence the high content of solvents. No electrolytes are added.

The American patent publication no 4640719 concerns a process for removal of soldering flux and tape remains from different types of electronic circuit boards. The removal is done by terpene compounds eventually in combination with tensides. The application is made full strength or in the form of a water diluted solution. Nothing is said about emulsion formation and stability. Here too the water seems to have primarily a carrying funktion. The process is entirely aimed at cleaning of

electronic components. No addition of elektrlytes of any kind is mentioned. The Swedish laid open patent publication no 441531 concerns a de- greasing agent based on solvents with a high content of aromatics, alkyl phenol etoxylate, alkane sulphonate,

emulsifier, potassium hydroxide, potassium silicate, phosphoric acid, eventually EDTA and glycol/isopropanol. The substances that in claims and summary are described as emulgators prove at scrutinizing the description to be what, with within the branch usual terminology, is described as thickeners. The stability problems which probably would have accured with the actual composition have been circumvented by using a thickened product.

The present invention concerns a method to produce at the site of use an inter alia for cleaning purposes suitable, stabile, water containing emulsion, especially a microemulsion, by mixing a premix, which is waterfree or contains relatively small amounts of water (below 10 weight %, preferably below 5 weight % ) and based upon a liquid mixture of one or more nonionic tensides, eventually one or more tensides with charge function and one or more organic solvents, with water and eventually electrolyte in solid or water solved state, at which the

emulsification will take place spontanously, that is with the minimum of agitation that is necessary to avoid layering caused by the different densities of the liquids. The resulting

emulsion should contain electrolyte, which is added as a

separate component at the mixing or is part of the premix.

Further the invention concerns a cleaning method consisting of application of an emulsion produced according to the invention followed by a wash with water, which may contain cleaning agent. Those steps may be followed by rinsing, application of polish and run off agents etc. in known way.

It concerns a premix too, which contains one or more nonionic tensides, eventually one or more tensides with charge function and one or more organic solvents in for spontanous formation of an emulsion at mixing with water suitable proportions.

Electrolytes may be added at the mixing or be present as water free particles homogenouεly dispersed in the tenside/solvent mixture.

Further the invention concerns the resulting emulsion which contains electrolytes too, preferably in the form of alkaline alkali metal salts and/or salts of ammonium or substituted ammonium or acids and/or acid metal salts and/or complex forming agents for multivalent metal ions, which improve the cleaning efficiency.

That the composition is water free or almost water free shall be understood in the way that water is not an essential component of the mixture. Part of the raw materials may be available only as water solutions or dispersions or may be needing small amounts of water for their solution. These solutions or

dispersions may be used without problem in the premix and give then rise to the small amounts of water (below 10, preferably below 5 weight %) mentioned above.

Preparation of the emulsion at the site of use may be done with all known methods for the mixing of two or more liquids. Even the agitation that is brought forward by the addition of water to the beforehand added premix is often enough. Another

alternative is agitation with pressurized air but this is not preferred as some evaporation of solvents then may occur and bring with it a less good working environment. If mechanical agitation is deemed proper simple propeller agitators are preferred.

A preferred mixer for the making of an emulsion according to the invention is constituted of a tank, which in its simplest version may be a slightly modified sheet-metal or plastic barrel, equipped with an upon the tank top mounted agitator. The agitator, which may have two or more blades, has a bearing in the shape of a tube connected to a pressure water tube. The shaft of the agitator is hollow and the cavity is branched along the blades to at least two diametrally opposite blade points and opens out there in against the radius perpendicular directions in such a way that the reaction force caused by the escaping water makes the agitator rotate. Such an agitator is the subject of Swedish patent application no 9002609-7.

As an equivalent alternative to agitators may be used a

specially designed supply arrangement for the water with

distribution in different jets, which give water movement in the entire tank to avoid local stagnant areas where layering may be retained.

The demand for accuracy at dosing at the final mixing is not large. It may for instance be sufficient with a simple level measurement, which may be made manually. Another preferred alternative is to use the packing volume as an estimate of premix and eventual liquid electrolyte volume and dilute with water to a fixed level afterwards.

The application of the final emulsion on the surfaces that are to be cleaned may be done by all known methods. For vehicles, for instance, manual guns, spray ramps, application as additiv to the water that sprinkles through the brushes and injection into the conduits that supply high pressure water may be proper alternatives. For other purposes as fire sanifying, degreasing etc application by sprinkling or dipping may be appropiate. It is of course advantageous if the emulsion after the appl i cati on may have a suitable short time period to work before the next step of the cleaning process follows.

The essential components of the premix are nonionic tenside and solvent. The choice of nonionic type tenside is not critical. All known nonionic tenside types may be used. The choice is first-hand dictated by economic and environmental

considerations. Where the disposition of waste water so allows, that is if there are no restrictions with the regard of tenside choice or if tenside and solvents may be removed from the waste water before treatment in waste water plants, alkoxylated alkyl phenols, especially those that are etoxylated or propoxylated and etoxylated are preferred. Such nonionic tensides give the best performance in proportion to their price. Other preferred nonionic tensides are alkoxylated higher alcohols, alkoxylated higher fatty acids and alkyl glycosides, which are environmentally better accepted and may be used in compositions that are equally effective as the alkyl phenol based ones but less favorable economically. Both primary and secundary alcohols may be used as well as so called oxo- alcohols.

Even nitrogen-containing nonionic tensides such as alkoxylated alkyl amides, alkoxylated alkyl amines and tertiary alkyl amine oxides may be used but are as a rule so expensive that they cannot be a dominating part of the composition. Small addition to modify the tenside properties may be of interest.

To the extent that those tensides are able to add hydrogen to a tertiary nitrogen atom and at least temporarily assume a quarternary configuration they are regarded as potential cationic tensides in connection with the invention.

Suitable nonionic tensides are relatively hydrophobe. With regard to the etoxylates mentioned above they belong to the categories that normally are called low etoxylated to middle etoxylated ones. With regard to the alkyl phenols the proper range is 1 to 10 moles, preferably 2 to 9 moles ethylene oxide if the alkyl part consists of 6 to 10 carbon atoms. With regard to alkanols the proper alkyl chain length is 8 to 18 carbon atoms and the nunber of ethylene oxide units 1 to 9, preferably 2 to 7. Alkoxylated nonionic tensides containing propylene and/or butylene oxide may be used if the ethylene oxide part is molarly in surplus. Other usable tensides are the so called end group capped alkoxylated nonionic tensides, that is tensides, where the end OH-group has been esterified or eterified with conservation of the nonionic character.

A nonionic tenside with a unitary degree of etoxylation may be used but mixtures give advantages with regard to cold

temperature stability and reduced gelling tendencies. An especially preferred mixture is nonyl phenol etoxylate with 9 moles ethylene oxide together with nonyl phenol etoxylate with moles ethylene oxide. Another preferred environmentally better mixture is fatty alcohol etoxylate with alkyl chain length 11 carbon atoms and 5 moles ethylene oxide together with fatty alcohol etoxylate of the same fatty alcohol and 7 moles ethylene oxide in the proportions 1:1 to 2:1. The performance of this latter mixture may be improved even further by adding a fatty alcohol etoxylate with alkyl chain length 11 carbon atoms and 3 moles of ethylene oxide in quantities up to 45 % of the total quantity of nonionic tensides.

Nonionic tensides with lower degrees of etoxylation are useable but not preferred as the content of unetoxylated material increases and may cause working environment problems inter alia with regard to smell. This is especially obvious with regard to etoxylated fatty alcohols. To the extent that so called narrow range alkoxylateβ becomes available to commersially acceptable prices the proper area of etoxylation degree will probably be displaced downwards.

In preferred composition there are one or more tensides with capacity to give the tenside micelles and thereby the emulsion particles a positive or negative charge included too. These other tensides are either cationic or anionic in character.

Cationic tenside should in this connection be interpreted in a broad sense and be considered to include all tensides that under the actual conditions of use are at least potential cationic tensides that is may assume cationic character and give the emulsion particles a positive charge. This is especially

relevant of the group alkoxylated alkyl amines. Those are in this case regarded as cationic tensides.

The category cationic tensides above thus will include a large number of different long chain compounds, which are able to give tenside micelles a positive charge, especially those that have a quaternary nitrogen atom already or those that are able by adding of hydrogen to a tertiary nitrogen atom to assume at least temporarily cationic function. Besides the conventional cationic tensides such as quaternary ammonium compounds, quaternary imidazolium compounds, long chain amines and long chain pyridines for example ampholyte tensides such as betaines and sultaines and zwitterionic tensides are included too.

Besides long and short alkyl chains the cationic tensides may contain benzyl and phenyl gruops and also hydroxy, ester and ether groups, especially polyglycol ether gruops as polyethylene glycol ether groups with chain length 2 to 20 ethylene oxide units.

From the economic and availability points of view quaternary ammonium compounds with a long alkyl chain (8 to 18 carbon atoms) and two short chained alkyl groups (1 to 4 carbon atoms) are preferred. The fourth group may be a short chain alkyl group too or consist of an etoxy chain with 2 to 20 ethylene oxide groups. Etoxylation improves the hydrotrop qualities of the tenside and reduces the tendencies of gelling at dilution with water. At least a certain part (5 to 50 weight % ) of the total quantity cationic tenside should consist of cationic tensides containing hydroxy and/or ether groups.

The counter ions to the cationic tensides may be the usual, that is halogenides, sulphates etc. If the compositons are used under circumstances where corrosion is a serious problem organic counter ions such as citrate and propionate ions may be

preferred. It is within the scoop of the invention to let part of the counter ions consist of anionic tensides. Generally speaking it is preferred in this case to let one tenside type be present in excess molarily seen.

Anionic tensides suitable for use in premixes and emulsion according to the invention may be found among all anionic

tenside types. In combinations where the anionic tensides is used as counter ion to cationic tensides relative cheap tensides as alkyl benzen sulphonate, alkansulphonate, olefin sulphonate and alkyl sulphate with alkyl chains within the range 8 to 22 carbon atoms are preferred. To the extent that anionic tensides are used without being combined with cationic tensides or potential cationic tensides generally more sofisticated anionic tenside types are preferred especially those that beside the anionic group contain alkylene oxide gruops for example alkyl ether sulphates and phosphoric acid esters. An especially preferred group consists of alkyl phenols respective fatty alcohols that have been esterified with phosphoric compounds.

Suitable solvents are low polar or nonpolar. Among those the choice from the technical point ov view is rather free. Solvents based on hydrocarbon with high aromatic content works well but are not suitable from outer and inner environmental point of view. Completely de-aromatized hydrocarbon solvents (below 0.5 % aromatic content) and normal paraffines are usable but not preferred with respect to the combination of cost and

performance. An often acceptable compromise with respect to environment and efficiency is low aromatic hydrocarbon solvents with up to 20 weight % aromatics.

More preferred solvent are iso-paraffins and cycloparaffins.

Especially the latter ones combine a serie of big advantages as excellent solution ability, freeedom of smell, low toxicity and as a consequence relatively high hygienic limits in air and relatively risk free skin contact, together with good

compatibility with other components.

Other preferred solvents are terpenes as D-limonene. Further pyrrol idones, caprolactames, esters, ethers, glycolethers etc. may be solvent components or dominating solvent. Combinations of solvents import often advantages with respect to gelling point, cold stability etc. On the other hand, for environmental

reasons, one tries to keep the number of components down to avoid unforeseen conspiring consequences. A preferred solvent combination is based upon a main part of cycloparaffin and a small amount of an ester of a lower alcohol as propanol and a short chained carboxylic acid as lactic acid. The ester addition lowers the turbidity point and gives increased cold stability. Emulsions according to the invention contain different

electrolytes as alkali, acids, complex formers etc. For the cleaning of road vehicles pH should generally be within the range 8 to 12. For passenger cars the proper range is within the lower or middle part of this range. For lorries and other heavier vehicles within the middle and higher part. The

composition should contain a sufficient alkali reserv not to allow pH being effected by eventual acid components of the vehicle soil. pH adjustment and regulation of the alkalinity may be done by using a complex former solution with a surplus of alkali, addition of a solution of alkali metal hydroxide and/or ammonium or solid alkali as alkali metal carbonate.

An interesting method is to let the premix be relatively acid for instance by the use of the acid form of one or more anionic tensides or by the addition of a hydrotrop in acid form.

Premixes containing anionic tensides often show improved

stability if they are present in acid form. Required alkalinity in the final mixture may be obtained by adjusting the

electrolyte addition.

For railway vehicles, where significant amounts of metal oxides especially iron oxide from the friction between wheels and rails may be a problem, acid composition are often preferred. The conditions may be of the same kind concerning cleaning of containers and goods, for instance cars and car parts that have been transported by rail. Acid compositions may also be

preferred at a number of other potential areas of use of the invention as enhanched oil recovery, cleaning within the food and other industries etc. The choice of proper acid depends upon the area of use. Where strongly acid compositions are needed and corrosion no important concern strong inorganic acids as

hydrochloric acid, sulphuric acid and nitric acids are prefered. In other cases relatively weaker unorganic acids as phosphoric acid, sulphamic acid and acid metal salts as sodium bi-sulphate are suitable choices. In still other cases moderately strong to strong organic acids as formic acid, oxalic acid, citric acids etc. may be appropiate. pH in acid compositions according to the invention may be between .5 and 4, preferably between .5 and 3.0.

Addition of complex formers to break the the bonds caused by multi valent metal ions is generally appropiate as soon as alkaline compositions are concerned. The complex formers may be oligomer or polymer phosphates as pyrophosphate,

tripolyphosphate, metaphosphate etc., amine polycarboxylates as nitrilo triacetic acid (NTA), ethylene di-amine tetraacetic acid (EDTA) etc., phosphonates and aminosphophonates. Part of these may in several cases be replaced by oligomer or polymer carboxylate compounds and/or cation exchanging zeolites. In acid compositions the need for complex formers is generally less.

To the extent that the electrolyte in its water free state is solid it may be present as dispersed small particles suspended in the tenside/solvent mixture, but this requires generally an advanced mixing apparatus including fine-grinding of the

particles and is not preferred. In water free state is included the cases too, where the main part of the water is present as crystal water. Most suitable complex formers are available on the market in the form of concentrated solutions at a price per active substance that is below the price of the water free product.

In these cases it is preferred to add the complex former as a concentrated water solution directly at the mixing of the water containing microemulsion. Even when the complex former may be bought to competitive price in its water free state it is usually preferred to add it in connection with the final mixing either as powder or as water solution as the presence of finely ground particles strongly increases the viscosity of the

tenside/solvent mixture, rises the turbidity point and reduces the stability and gives the mixture increased tendencies to gelling.

Besides the additives mentioned the mixtures according to the invention may contain other common additives to this type of agents as fluor tensides to enhance the wetting of plastic surfaces etc., corrosion inhibitors, stabilizing agents, solubilizers (hydrotropes), viscosity adjusters, freezing point reducing agents etc.

The proportion of nonionic tenside to cationic tenside if it is added should be at least 2:3 and preferably at least 1:1. As the nonionic tenside is less costly than the cationic tenside it is preferred to increase its proportion as much as possible without seriously deteriorating the performance of the product. The possibilities of this are far better, when the nonionic tenside wholly or to considerable extent consists of alkoxylated nonyl phenols. In these cases one is able to create very efficient mixtures with a proportion nonionic tenside to cationic tenside of 100:1 or sometimes even higher. Concerning mixtures based upon alkoxylated higher alcohols the conditions are not equally favorable and appropiate mixing proportions are therefore close to the lower values above. Suitable mixing proportions

concerning nonionic tensides to cationic tensides are thus from 2:3 to 150:1, preferably from 1:1 to 100:1 and more preferably from 1:1 to 80:1.

To the extent that anionic tensides are used as charge giving tensides that is not solely as counter ions to cationic tensides the proportion nonionic tenside to anionic tenside should be at least 2:3, preferably 1:1. In this case too the proportion of charge giving tenside may be rather small. Proportions nonionic tenside to anionic tenside of 100:1 are well usuable. Generally seen, however, the proportion should not exceed 80:1.

Generally seen one is striving to keep the content of organic solvents as high as possible in proportion to other components. The limit is usually set by the possibilities of incorporating the solvents into the composition. Concerning the present water free compositions the upper limit of solvent addition with the mai ntenace of a clear, easy-flowing mixture is as highest about 50 weight %, usually it is lower as 40, 30 or 20 weight %. The lower level of solvent addition is about .5 weight %. Besides the already mentioned areas of use , cleaning of road vehicles and railway vehicles, processes and agents according to the invention are suitable for a large number different

applications as degreasing within the industry, cleaning of machines in work shops and industry, cleaning of agricultural and excavating machines, cleaning of aeroplanes, sanifying after fires, enhanched oil recovery etc. The tenside/solvent

containing mixture does in most cases not need any separate adjustment but has a generally seen universal usability. The adjustment to special areas of use is mainly done by the choice of electrolyte additives. This adjustment is thus to a high degree simplified by the method of final mixing directly in connection with the site of use.

Compositions according to the invention will to large extent be used in locations, where the temperature at winter may be very low. Therefore it is advantageous if both the concentrate and the ready-made emulsions remain stable down to or below the freezing point. Starting instability is shown by turbidity.

Stability should be present down to +10 °C, preferably down to 0 °C, and more preferably to -8 °C. Empirically, compositions with good stability in the final emulsion seems to be satisfactory regarding stability in concentrate form too.

Further the compositions should be able of being diluted with cold water without showing gelling tendencies. As a fast test of suitability mixing of 15 grammes concentrate, 3 grammes 38 % NTA-solution and diluting to 1 liter with tap water (+8 °C) while agitating with a magnetic stirrer is applied. Under those conditions a period of 1 minute to complete dispersion and formation of a clear, slightly opalescent liquid is considered as satisfactory.

It should, however, be noticed that compositions with less good cold stability and cold water dispersability are well usable where the conditions regarding cold stability respective

diluting qualities with cold water are less stringent. Example 1. A mixture consisting of

24.6 weigt % alkyl phenol etoxylate with about 10 carbon atoms in the alkyl part and 4 moles of ethylene oxide,

20.5 weight % nonyl phenol etoxylate with 9 moles ethylene oxide,

23.0 weight % phenol etoxylate with 4 moles ethylene oxide,

1.2 weight % quaternary cocoa fatty amine etoxylate with about 10 moles ethylene oxide,

.4 weight % cetyl tributyl ammonium bromide,

30.3 weight % cycloparaffin hydrocarbon solvent with starting boiling point 157 °C and flame point 43 °C, was made. The mixture was a clear, easy-flowing liquid.

250 litres of the mixture were mixed with 25 litres of NTA- solution (38 weight %) , which also contained a lye surplus of 1 to 5 weight %. The mixture was diluted to 1000 litres with cold water from a tap. No gelling tendencies were noticed at the dilution. The composition, which was a clear liquid with very slight opalescensce, was applied by spraying upon greasy and dirty machine parts. After flushing with high pressure water the parts were both clean and effectively de-greased.

150 litres of the mixture were mixed with 25 litres NTA-solution (38 weight %) containing lye surplus. The mixture was diluted to 1000 litres with cold water. The composition was a clear liquid with very slight opalescence and was applied by spraying upon dirty car chassis. Flushing with high pressure jets gave an extraordinarily efficient cleaning. The composition was used for injection into a high pressure wash for passenger cars too and showed highly improved cleaning efficiency.

50 litres of the mixture were mixed with 5 litres NTA-solution (38 weight %). The mixture was diluted to 1000 litres with cold water. The composition was like in other cases a clear, very slightly opalescent solution. It was applied by a spray ramp upon covered lorries. Following wash in a wash plant with high pressure jets completed with manually operated hand operated guns at for ramp-mounted guns in-accessible places showed improved result compared with microemulsions that were delivered ready-mixed.

5 litres of the mixture were mixed with 2.5 litres NTA-solution (3B weight %) and diluted to 1000 litres with cold water. The composition was like in other cases a clear, very slightly opalescent solution. It was applied by a spray ramp upon

passenger cars. The following wash in a brush washing plant showed improved result compared with microemulsions that were delivered ready-made.

Example 2. A mixture of

13 weight % etoxylated fatty alcohol with 11 carbon atoms in the alcohol chain and 7 moles ethylene oxide per mole fatty alcohol ,

26 weight % etoxylated fatty alcohol with 11 carbon atoms in the alcohol chain and 5 moles ethylene oxide per mole fatty alcohol,

33 weight % cationic tenside of the quaternary cocoa fatty amine etoxylate type with about 15 moles ethylene oxide, .4 weight % mono cetyl tributyl ammonium bromide,

20,2 weight % cykloparaffin hydrocarbon with starting boiling point at 182 °C and flame point 60 °C,

2,0 weight % propylene glycol

5,2 weight % sodium-N-lauryl sarcosinate (35 % solution), was prepared. The product was a clear, easy-flowing liquid. It was used in the same way as the product according to example 1 och and showed equivalent qualities with respect of dispersion without gel formation and cleaning result.

Example 3.

Experiment 2 was repeated with the difference that the

concentration of nonionic tenside was increased to 44,2 weight % and entirely constituted of fatty alcohol etoxylate with 11 carbon atoms in the alcohol chain and 5 moles ethylene oxide per mole fatty alcohol at the same time as the addition of sodium-N-lauryl sarcosinate fell away. The composition was a clear liquid and could be used in the same way and with comparable results as the composition according to example 2. Samples of the

composition according to example 2 and example 3 were diluted in the proportions 15 grammes premix, 3 grammes NTA-solution (38 weight %) and cold water to 1 litre. The obtained emulsions were subjected to cooling tests. The composition according to example

2 did not become turbid until -5 °C the one according to example

3 became turbid at +8 °C.

Example 4.

Experiment 3 was repeated with the difference that the nonionic tensid quantity now was constituted of fatty alcohol etoxylate with 11 carbon atoms in the alcohol chain and 7 moles ethylene oxide per mole fatty alcohol. The composition was diluted in the same way as according to example 3. The emulsions obtained showed better cold stability than those according to example 3 but also encreased tendencies to gelling at dilution with water (did not pass the gelling test above).

Example 5. A mixture of

49 weight % etoxylated fatty alcohol with 11 carbon atoms in the alcohol chain and 5 moles ethylene oxid per mole fatty alcohol,

4,4 weight % fatty alcohol with 9 carbon atoms in the alcohol chain and alkoxylated with 3 moles propylene oxide and 9 moles ethylene oxide,

14,5 weight % cationic tenside of the quaternary cocoa fatty amine etoxylate type with about 15 moles ethylene oxide,

2,3 weight % mono-cetyl tri-butyl ammonium bromide,

29,8 weight % cykloparaffin hydrocarbon with starting boiling point at 182 °C and flame point 60 °C,

was prepared. The product was a clear, easy-flowing liquid. It was used in the same way as the product according to example 1 and showed comparable result. Example 6.

The experiment according to example 1 was repeated with the difference that the solvent, cykloparaffin hydrocarbon, was exchanged against D-limonene. The compositions were used in the same way and showed comparable performances.

Example 7. A premix was prepared of

31 weight % fatty alcohol etoxylate with 11 carbon atoms in the alcoholic chain and on an average 5 mol ethylene oxide,

10,5 weight % fatty alcohol etoxylate with 11 carbon atoms in the alcoholic chain and on an average 7 mol ethylene oxide,

32,5 weight % quaternary cocoa fatty amine etoxylate with about 15 moles ethylene oxide,

5,2 weight % sodium-N-lauryl sarcosinate (35 % solution),

20,2 weight % cykloparaffin hydrocarbon solvent with starting boiling point at 157 °C and flame point 43 °C

The product was a clear, easy-flowing liquid. It was used in the same way as the product according to example 1 and and showed equivalent qualities.

Example 8. A premix was prepared of

23 weignt % fatty alcohol alkoxylate containing a mixture of ethylene oxide and propylene oxide (Miravon B12DF,

biologically degradeable low foaming nonionic tenside),

31 weight % fatty alcohol alkoxylate containing a mixture of ethylene oxide and propylene oxide (Miravon B79R),

biologically degradeable nonionic tenside),

8 weight % cumene sulphonate (water free),

8 weight % water,

15 weight % sodium-N-lauryl sarcosinate (35 % solution),

15 weight % cykloparaffin hydrocarbon solvent with

starting boiling point 157 °C and flame point 43 °C.

The mixture was a clear, easy-flowing solution. It was used in the same way as the product according to example 1 and and showed equivalent qualities. Example 9. A premix was prepared using

7 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 5 moles ethylene oxide,

9 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol and 7 moles ethylene oxide,

11 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 3 moles etylene oxide,

12 weight % phosphate ester of nonyl phenol etoxylate with moles ethylene oxide,

10 weight % di-propylene glycol metyl ether,

9 weight % cumene sulphonate (water free),

3 weight % water,

19 weight % cykloparaffin hydrocarbon solvent with starting boiling point at 182 °C and flame point 60 °C.

The mixture was a clear, easy-flowing solution. It was used in the same way as the mixture according to example 1 and and showed equivalent qualities.

Example 10. A premix was prepared using

7 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 5 moles ethylene oxide,

9 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol and on an average 7 moles ethylene oxide,

11 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 3 moles ethylene oxide,

12 weight % phosphate ester mixture consisting of 50 weight % phosphate ester of a fatty alcohol etoxylate of a fatty alcohol with 12 to 14 carbon atoms and etoxylated with 3 moles ethylene oxide and 50 weight % phosphate ester of a fatty alcohol etoxylate of a fatty alcohol with 14 to 20 carbon atoms and etoxylated with 8 to 12 moles ethylene oxide, 10 weight % di-propylene glycol metyl ether,

9 weight % cumene sulphonate (water free),

3 weight % water,

19 weight % cykloparaffin hydrocarbon with starting boiling point at 162 °C and flame point 60 °C.

The mixture was a clear, easy-flowing solution. It was used in the same way as the mixture according to example 1 and and showed equivalent qualities.

Example 11. A premix was prepared of

32,1 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 5 moles ethylene oxide,

9,5 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol and on an average 7 moles ethylene oxide,

11,9 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the alcohol chain and on an average 3 moles ethylene oxide,

16,7 weight % phosphate ester of nonyl phenol etoxylate with

4 moles ethylene oxide,

9.5 weight % di-propylene glycol metyl ether,

3.6 weight % cumene sulphonate (water free),

16,7 weight % cykloparaffin hydrocarbon solvent with starting boiling point at 182 °C and flame point 60 °C.

The mixture was a clear, easy-flowing solution with pH between 3 and 4. 15 g of the mixture was mixed with 2 g NTA (38 %

solution) and diluted to 100 ml with tap water. The mixture was turbid but cleared up at addition of small amounts of potassium lye. If the potassium lye was added to the NTA-solutionen

instead the mixture became clear direktly at the dilution.

Example 12.

To test different cold stabilizing additives the following experiment was made. A start mixture containing 41,5 weight % fatty alcohol etoxylate with on an average 11 carbon atoms in the fatty alcohol and on an average 5 moles ethylene oxide,

33.0 weight % quaternary cocoa fatty amine etoxylate with about 15 moles ethylene oxide,

0,4 weight % mono-cetyl tri-butyl ammonium bromide,

20.1 weight % cykloparaffin hydrocarbon solvent with starting boiling point 157 °C and flame point 43 °C, was prepared. The missing 5 weight % consisted of a row of different solvents respektively other additives that usually are thought to be cold stabilizing. The mixtures were diluted in the earlier mentioned proportions 15 g premix, 3 g NTA (38 weight %) and rest to 1 liter tap water.

The zero sample, where the extra 5 weight % were constituted of water, became turbid at +10 °C, while the samples with each 5 weight % addition of propyl lactate, sodium-N-lauryl sarcosinate (35 weight %) and fatty alcohol with on an average 11 carbon atoms etoxylated with on an average 7 moles ethylene oxide did not become turbid until at -5 °C. Other additives had as a rule a certain effect upon the cold stability but this effect was less than the effect of those three mentioned. A number of different dilution proportions were tested besides those mentioned. The turbidity point showed to be generally

independent of the dilution proportions.

Example 13.

The premix according to example 1 was mixed with oxalic acid in the weight proportions premix to oxalic acid 10:1 and was

diluted with vatten in the weight proportions premix to vatten 1:6. The composition obtained had pH about 2 and was used for the cleaning of railway cars and showed an excellent efficiency especially for the removement of hard to remove iron oxide.

Claims

Patent claims

1. Process for cleaning and de-greasing with the aid of a water containing emulsion, especially a microemulsion characterized in that the emulsion is prepared at the site of use by the mixing of an easy-flowing water free or nearly water free (below 10 weight %) composition, containing one or more nonionic tensides, one or more organic solvents and eventually one or more tensides with charge giving function and eventually electrolyte in solution or in the shape of solid state, dispersed, finely divided particles, with water and eventually solid state electrolyte, liquid electrolyte or electrolyte solution at the site of use, at which the final emulsion will contain electrolyte and the emulsion formation will occur spontanously that is without agitation or with the minimum of agitation only that is needed for the

elimination of layering caused by the different densities of the liquids.

2. Process according to claim 1 characterized in that the process comprises treatment with the water containing

emulsion followed by wash with water, which may contain cleaning agents.

3. Process according to claim 1 och 2 characterized in that the emulsion is applied with low pressure guns and the rinsing is done with high pressure guns or water sprinkling brushes.

4. Process according to claim 1 characterized in that the emulsion is used as additive to a wash solution, which is applied with high pressure guns or used as sprinkling

solution for wash brushes.

5. Process according to claim 1 characterized in that charge giving tenside is present and is cationic and that the proportion between the total content of nonionic tensides, apart from nitrogen containing nonionic tensides that are able to assume cationic charge, and cationic tenside lies within the range 2:3 to 150:1, preferably within the range 1:1 to 100:1 and more preferred 1:1 to 80:1.

6. Process according to claim 1 characterized in that charge giving tenside is present and is anionic and that the proportion between the total content of nonionic tenside and anionic tenside lies within the range 2:3 to 100:1,

preferably within the range 1:1 to B0:1.

7. Process according to claim 1 to 6 characterized in that the content of organic solvents in the water free or nearly water free mixture is between .1 and 50 weight %, preferably between 10 and 30 weight %.

8. Process according to claim 1 to 7 characterized in that complex former for multivalent metal ions is added as a separate additive at the mixing of the water free or nearly water free composition with water.

9. Process according to claim 1 to 7 characterized in that separate electrolyte or electrolyte is added at the mixing and contain alkaline substance and/or complex former for multivalent metal ions and that pH in the final emulsion lies within the range 8 to 12.

10. Process according to claim 1 to 7 characterized in that separate electrolyte or electrolyte solution is added at the mixing and contains acid and/or acid salt and/or complex former and that pH in the final emulsion lies between .5 and 4.0, preferably between 1.0 and 3.0.

11. Process according to claim 1 to 9 characterized in that the solvent to a significant part is constituted of cyclo paraffin hydrocarbons with starting boiling point within the range 150 to 185 °C and flβmpunkt over 40 °C.

12. Process according to claim 1 to 9 characterized in that the solvent to a significant part is constituted of terpenes with flams point above 40 °C.

13. Process according to claim 1 to 9 characterized in that the solvent to a significant part is constituted of low aromatic hydrocarbon solvents with starting boiling point at 150 to 200 °C and flame point above 40 °C.

14. Spontanously emulsifying composition intended as premix for the preparation of a stabile, water containing,

electrolyte containing emulsion, especially a microemulsion, with a simple mixing equipment at the site of use

characterized in that the composition is easy-flowing and water free or nearly water free and contains one or more nonionic tensides, one or more solvents and eventually one or more tensides with charge giving function and/or one or more electrolytes in solution or in the shape of solid state, finely divided particles, at which the emulsion is containing electrolyte and the emulsion formation will occur

spontanously that is witout agitation or with the minimum of agitation that may be needed to avoid layering caused by the different densities of the liquids.

15. Composition according to claim 14 characterized in that charge giving tenside is present and is cationic and that the proportion between the total content of nonionic tensides, apart from nitrogen containing nonionic tensides that are able to assume cationic charge, and cationic tenside lies within the range 2:3 to 150:1, preferably within the range 1:1 to 100:1 and more preferred 1:1 to 80:1.

16. Composition according to claim 14 characterized in that charge giving tenside is present and is anionic and that the proportion between the total content nonionic tenside and anionic tenside lies within the range 2:3 to 100:1,

preferably within the range 1:1 to 80:1.

17. Composition according to claim 14 to 16 characterized in that the content of organic solvents in the water free or nearly water free mixture is between .1 and 50 weight %, preferably between 10 and 30 weight %.

18. Water containing emulsion, especially microemulsion, obtained by the mixing of a spontanously emulsifying

composition with water and eventually electrolyte

characterized in that the preparation is made in a mixing equipment at the site of use and that the composition is easy-flowing and water free or nearly water free and contains one or more nonionic tensides, one or more solvents,

eventually one or more tensides with charge giving function and eventually one or more elektrolytes and that the emulsio is containing electrolyte and the emulsification will occur spontanously, that is without agitation or with the minimum of agitation that may be needed to avoid layering caused by the different densities of the liquids.

19. Use for claning purposes of a water containing emulsion, especially a microemulsion, characterized in that the

emulsion is obtained by the mixing of a spontanously

emulsifying composition with water and eventually electrolyte, at which the preparation is made in a mixing equipment at the site of use and the composition is easy-flowing and water free or nearly water free and contains one or more nonionic tensides, one or more solvents, eventually one or more tensides with charge giving function and eventually one or more electrolytes in solution or in the shape of solid state finely divided particles and that the emulsion is containing electrolyte and the emulsification occurs

spontanously that is without agitation or with the minimum of agitation that may be needed to avoid layering caused by the different densities of the liquids.