EP0666897B1 - Method and composition for degreasing the surface of an object - Google Patents

Abstract

A method for degreasing the surface of a metal object by applying a composition containing at least 25 wt % of an amphiphilic compound, then rinsing the surface with water.

Description

The present invention relates to the degreasing of the surface of a metal, ceramic, glass, or made of plastic.

The most effective degreasing processes are carried out using chlorinated solvents, in particular 1,1,1 trichloroethane. These are harmful products to the environment, especially the ozone layer stratospheric. It is planned to prohibit its use in the years to come. We also know processes aqueous less effective despite their complex formulations to water base, saponification agents (soda, potash, silicate, phosphate, borate or carbonate), chelation and surfactants.

EP-A-0 564 402, published after the priority date which benefits part of this application, describes in synthesis examples 2 and 3 of detergents added, after purification, to water (15% by weight of the final composition).

Now we have now found a process and a composition which can be used to degrease the surface of an object more efficiently than the 1,1,1 trichloroethane, without having the disadvantages and without needing to be associated according to formulations complex.

The subject of the invention is therefore a method of degreasing the surface of a metallic object, ceramic, glass or plastic, which consists of apply to it a composition comprising a compound amphiphilic formula A-B, A being a lipophilic radical and hydrophobic and B a hydrophilic radical. The process is characterized in that it consists in using a composition comprising at least 25% and preferably at least 60% by weight of the amphiphilic compound of formula A-B then serving as solvent, so as to form an oil or fat amalgam - compound A-B thanks to the radical A, then rinse the surface to water so as to remove the amalgam from the surface, this elimination being made possible thanks to the hydrophilicity of the amalgamation due to the presence of the radical B.

The amphiphilic solvent of structure A-B is chosen so that Part A has the best affinity for the oil considered. A priori, this amphiphilic solvent will be used pure. If this is not possible, it will be added of one or of co-solvents, taking care to put the least possible. Indeed, if the amphiphilic solvent is too diluted, it will no longer be able to play its role of amalgam formation and will play the classic (non-performing) role of surfactant. In conventional detergency, the surfactant comes adsorb on oil to minimize tension interfacial between the oil and the aqueous solution. Task oil comes off giving a drop so as to minimize interfacial tension. The surfactant thus makes it possible to obtain an oil dispersion in the aqueous solution. The rates of surfactants used are generally weak (some for hundred).

Addition of amphiphilic solvent on the layer fat aims to increase the hydrophilicity of this layer. The amphiphilic solvent dissolves the fatty layer well or is very miscible with it, due to its segment A having a very good affinity for oils and fats. This very good dissolution or miscibility leads to the formation of an amalgam of oil-amphiphilic solvent. As a result of its hydrophilicity, this amalgam is easily eliminated by a simple rinse with water. Part B of the amphiphilic solvent is for example an ionic head or an ethoxylated chain.

dans laquelle

R₁ est un atome d'hydrogène ou un groupe hydrocarboné, éventuellement substitué, ayant de 1 à 20 atomes de carbone ou un groupe hydrocarbylcarbonyle (R₇-COO-, R₇ étant H, alcoyle ou alcényle de 1 à 20 atomes de carbone; cette définition s'applique aussi aux autres groupes hydrocarbonés) ayant de 1 à 21 atomes de carbone, R₂ est un atome d'hydrogène ou un groupe hydrocarboné, éventuellement substitué, ayant de 1 à 20 atomes de carbone, l'un au moins de R₁ et R₂ ayant au moins 10 atomes de carbone,

R₃, R₄, R₅ et R₆, qui peuvent être identiques ou différents, sont l'hydrogène ou un groupe hydrocarboné, éventuellement substitué, ayant de 1 à 6 atomes de carbone, et n est un nombre entier de 1 à 12.

As amphiphilic solvents, it is possible in particular to use alkyl sulphates, alkyl ether sulphates, nonylphenyl ether sulphates, sulphosuccinates, hemi sulphosuccinates, alkyl benzenesulphonates, derivatives of amino acids or proteins, ethoxylated fatty alcohols, ethoxylated fatty acids, ethoxylated fatty acids , sorbitan esters, ethoxylated sorbitan esters, ethoxylated alkylphenols, fatty amides, fatty esters, oxyethylated primary monoamines, oxyethylated diamines, primary monoamine acetates, diamine diacetates, diamine dioleates, salts quaternary ammonium, amine oxides, etheramines, etherdiamines. It is particularly preferred to use alkylene glycol etheroxides of formula

in which

R ₁ is a hydrogen atom or an optionally substituted hydrocarbon group having from 1 to 20 carbon atoms or a hydrocarbylcarbonyl group (R ₇ -COO-, R ₇ being H, alkyl or alkenyl of 1 to 20 carbon atoms ; this definition also applies to other hydrocarbon groups) having from 1 to 21 carbon atoms, R ₂ is a hydrogen atom or an optionally substituted hydrocarbon group having from 1 to 20 carbon atoms, one to less than R ₁ and R ₂ having at least 10 carbon atoms,

R ₃ , R ₄ , R ₅ and R ₆ , which may be the same or different, are hydrogen or an optionally substituted hydrocarbon group having from 1 to 6 carbon atoms, and n is an integer from 1 to 12 .

It has been found, in fact, that these alkylene glycol etheroxides, because of their long hydrocarbon chain, in particular having 11 to 18 carbon atoms, and the presence of an ethoxylated segment, are very effective in degreasing a surface. Particularly preferred are alkylene glycol etheroxides, in which R ₁ has at least 10 carbon atoms. The hydrocarbon group which constitutes R ₁ or R ₂ may in particular be alkyl, alkenyl, cycloalkyl, alkylaryl and aralkyl, and in particular substituted by a hydroxyl group or by a hydroxyalkoxyl group. R ₁ can come from an acetate, a propionate, a butyrate, a valerate, a cyclopentacarboxylate, a caproate, a cyclohexacarboxylate, an enanthoate, a benzoate, d 'a caprylate, a perlagonate, a caprate, a laurate, a myristate, a palmitate, a stearate, an oleate. R ₂ can be methyl, ethyl, propyl, amyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, vinyl, octyl, pentadecyl, oleyl. When R ₁ is a ricinyl radical, it is a product derived from castor oil of natural origin. The most common and therefore preferred alkylene glycol etheroxides are those in which R ₃ , R ₄ , R ₅ and R ₆ are hydrogen atoms.

The invention also relates to a composition of degreasing as defined in claim 4. When the oil to be removed from the surface is very viscous, the composition makes it more fluid, and therefore, to facilitate its subsequent elimination by water. When using mixtures of alkylene glycol etheroxide in the composition, the composition is heterogeneous. A simple shaking makes it homogeneous for many hours. This homogenization can be facilitated by heating at a temperature between 30 and 60 ° C and preferably between 30 and 40 ° C. For homogenize the composition permanently, we add 15 to 20% water and preferably 15 to 18% of water by weight. No more than 20% should be added of water under penalty of observing a formation of gel and obtaining viscous and heterogeneous mixtures, instead of a product oily.

Once the composition has been deposited on the surface to degrease, the step of rinsing with water often gives a gel viscous, which can be removed by mechanical action (friction or jet under high pressure). To overcome this disadvantage, we can add to the composition from 10 to 20% by weight of an agent promoting the miscibility of compound A-B, especially alkylene glycol etheroxide, in water. This agent can be a lower alcohol, in particular an alkanol or a glycol. Diacetone alcohol, a alkylene glycol such as an alkyl glycol, hexylene glycol, a branched alkanol such as secondary butanol, or even etheroxides such as monobutyl oxide diethylene glycol or other glycol etheroxides particularly interesting due to their low toxicity. The amount of miscibility promoting agents is advantageously between 10 and 20% by weight. Under his most completed form, a composition according to the invention may comprise by weight from 60 to 75% of the etheroxide alkylene glycol or a mixture thereof, from 15 to 20% of water and 10 to 20% of an agent promoting the miscibility of alkylene glycol etheroxide in water.

The invention also relates to a method of degreasing the surface of an object, which consists of apply per square centimeter of the surface, from 0.2 to 1 mg of a compound A-B, in particular of an alkylene glycol etheroxide as mentioned above, or of a composition such as mentioned above. The duration of application of the product amphiphilic A-B on the fatty layer can be between at least about a second and 10 minutes or more following the extent of the surface to be cleaned. After that, we eliminate alkylene glycol etheroxide from the surface by applying it water, this application can be carried out by immersion, by sprinkling or rubbing the surface using a damp cloth. You can also use a water jet.

There is a process for preparing alkylene glycol etheroxides used according to the invention in the United States patent US-A-4,022,808, and to European patent application EP-A-0 335 295.

The following examples illustrate the invention.

Alkylene glycol etheroxides called "ethoxylated metiloils" were used which can be obtained from the company Seppic, 75 quai d'Orsay, Paris France. These compounds have 2 to 5 moles of ethylene oxide. R ₂ is methyl there and R ₁ is a mixture of C 11, C 13 and C 18 monocarbonylated hydrocarbons. They are essentially methyl esters. On average, either 2 moles of ethylene oxide or 5 moles of ethylene oxide were added to the metiloil.

Ethoxylated metiloils are therefore mixtures complex by the composition of the metiloil and by the degree of ethoxylation. This complexity leads to heterogeneity of the product for metiloil 5 OE. So we have initially sought to make this product homogeneous (existence of a single phase at room temperature either 20 ° C).

This mixture becomes homogeneous by adding 15 to 18% water. But if we add 20% water or more, we observe the formation of lamellar phases (gel) and we obtain viscous and heterogeneous mixtures. These gels seem all the more more persistent than the number of EO is higher (8 EO, 10 EO and 12 EO). Metiloil 2 OE gives emulsions milky with water in all proportions which become very quickly viscous.

Métiloil 5 OE remains heterogeneous at temperature ambient. Above 20% water, it leads to a gel. We therefore prefer to use the minimum possible rate of 15% of water by weight.

The second step of the process consists in rinsing with water the coated surface of the amalgam oil - amphiphilic solvent. This amounts, among other things, to adding water to the Metiloil 5 OE formula, therefore to obtaining a percentage of water greater than 20% and relapsing into the formation of the lamellar phases. This is indeed what happens during rinsing with water: we observe the formation of a viscous gel on the surface. To remedy this drawback, if desired, a co-solvent of the alcohol or glycol type can be added. Diacetone alcohol, hexylene glycol, secondary butanol or even diethylene glycol monobutyl ether can be used, for example. This latter solvent, which is part of the family of glycol ethers, turns out to be particularly advantageous because of its very low toxicity and its superior performance compared to other alcohols or glycols. The minimum amount of diethylene glycol monobutyl ether (DGB) is 15% by weight. The following mixtures were made: 77% Metiloil 5 OE + 15% water + 8% BDG. 75% Metiloil 5 OE + 15% water + 10% BDG. 70% Metiloil 5 OE + 15% water + 15% BDG.

The dilution in water of the first two formulas leads to the formation of a milky emulsion. The dilution in the water of the 3rd formulation leads to obtaining a translucent phase characteristic of microemulsions. It is the desired result.

Thus, typically, 70% by weight of the amphiphilic solvent (Metiloil 5 OE) added with 15% water and 15% of BDG.

For any other amphiphilic solvent, this study of formulation must be done taking into account the two properties sought: homogeneity of the initial product and miscibility in all proportions with water.

Examples Example 1

The following wording was used: Metiloil 5 OE 70% diethylene glycol monobutyl oxide 15% water 15%

On a NM 22 S steel plate, dimensions 10 x 10 cm, degreased by the hot trichloroethane cycle, cold, vapor phase, deposit a thin layer of petroleum jelly. Using a cloth soaked in the above mixture, the plate coated with vaseline oil is rubbed. After 2 or 3 successive passages, the plate is placed under a jet of water (15 seconds). We then obtain a very good spreading of the film of water which is significant of a clean surface. The angle of contact with a drop of water deposited on such a surface is between 50 and 60 °.

With trichloroethane (T111) and only 2 successive rags, there remains a greasy film on which water is in the form of droplets, which is significant of a fatty surface (the contact angle of a drop of water deposited on such a surface is much higher at 60 °).

Two successive passes with the T111 are not enough. Only by using a lot more T111 (because it evaporates) and by multiplying the friction, that we arrive at a result comparable to that obtained with the formula above.

Example 2

The formula of Example 1 is diluted for half with water. We therefore prepared and used in this example, the following formulation: Métiloil 5 OE 35% diethylene glycol monobutyl oxide 7.5% water 57.5%

Under these conditions, the amount of water compared with Métiloil 5 OE is much higher than 15%. So is even for the amount of monobutyl oxide in the diethylene glycol (21% compared to Métiloil 5 OE).

We are therefore in the conditions defined to have the miscibility of all constituents with infinite dilution.

As described in example 1, the test is carried out degreasing. We obtain an efficiency similar to Example 1.

Example 3 (for comparison)

The formula of Example 2 is diluted for half with water. We therefore use, in this example, the following formulation: Metiloil 5 OE 17.5% diethylene glycol monobutyl oxide 3.5% water 79%

The amounts of monobutyl oxide in diethylene glycol and water compared to Métiloil 5 OE are well above 15%. We stay in the conditions defined to have the miscibility of all the constituents infinite dilution.

In this example, the amount of Metiloil 5 OE is greatly reduced and we arrive in the area of use of a surfactant (maximum rate) in detergency.

Analogously to Example 1, but using this new formulation, performance is poor and comparable to those of the T111 with only 2 passes successive rag. Therefore, when using the Métiloil 5 OE at a rate corresponding to the maximum of what used in conventional detergency (15 to 20% of the surfactant), the efficiency is zero.

Example 4

In this new example, sodium dodecylbenzenesulfonate is used as the amphiphilic solvent. This compound AB has a lipophilic part (dodecylbenzene) and a hydrophilic part (ionic head sulfonate of Na). This compound is a solid at room temperature. It must therefore be dissolved in a liquid before it can be used. The following formulation was prepared and used: Na dodecylbenzenesulfonate 42.5% diethylene glycol monobutyl oxide 15% water 42.5%.

The mixture obtained is much more fluid than the 50% mixture of Na dodecylbenzenesulfate + 50% water. This is due to the 15% monobutyl oxide in the diethylene glycol. This fluidity allows good spreading cloth as in example 1.

As described in example 1, the test is carried out degreasing. We obtain an efficiency similar to Example 1.

8 mixtures called MeT 1 to MeT 8 are carried out, in accordance with the weight formulations indicated below. These mixtures are homogeneous products, which are stable at low temperature (around 5 °) and which are not destabilized by infinite dilution with water (with the exception of Met 1). MeT 1 Métiloil 5 OE 100% MeT 2 Métiloil 5 OE 70% diethylene glycol monobutyl oxide 15% Water 15% MeT 3 Métiloil 5 OE 70% Hexylene glycol 15% Water 15% MeT 4 Métiloil 5 OE 70% diethylene glycol monobutyl oxide 8% Diacetone alcohol 8% Water 14% MeT 5 Métiloil 5 OE 70% Hexylene glycol 8% Diacetone alcohol 8% Water 14% MeT 6 Métiloil 5 OE 70% Secondary butanol 10% Water 20% MeT 7 Métiloil 5 OE 50% Métiloil 2 OE 20% diethylene glycol monobutyl oxide 15% Water 15% MeT 8 Métiloil 5 OE 70% ethyl alcohol 15% water 15%

Example 5

We use example 1 again, but using the MeT 7 mix instead of MeT 2 mix. Performance obtained are excellent and comparable to those found for MeT 2.

Example 6

We use example 1 again, but using the MeT 3, MeT 4, MeT 5 or MeT 6 mixtures. obtained are very good and comparable to good degreasing to T 111 (cloth, rubbing vigorously and several successive passages).

Example 7

The procedure is as in Example 1, but by rinsing successively the plate with methanol and water; MeT 1 gives good degreasing performance.

Example 8

We operate as in Example 1 and using the MeT 2 or MeT 7 mixtures, but applying the product by spray or soak (and no longer with a cloth), results are absolutely identical to those obtained at Example 5.

Example 9

50 % huile de vaseline,

25 % huile ALEDA (huile minérale phosphochlorée),

25 % huile ETIRELF (huile entièrement sans chlore).

Example 1 is used again, but using a mixture of 3 oils:

50% petrolatum oil,

25% ALEDA oil (phosphochlorinated mineral oil),

25% ETIRELF oil (completely chlorine-free oil).

The results are still as good with MeT 2 and MeT 7.

Example 10

We proceed as in Example 1, but using KFP 5/8 impact oil, the performances obtained are still as good with MeT 2 and MeT 7.

Example 11

We use example 1 again, but using the MeT 8 mixture:

We obtain results similar to those of Example 5.

Claims (4)

1. Process for degreasing the surface of a metal, ceramic, glass or plastic object, which comprises applying thereto a composition comprising an amphiphilic compound of formula A-B, wherein A is a lipophilic and hydrophobic radical and B is a hydrophilic radical,
   characterised in that it comprises

   using an oily composition comprising at least 25% and preferably at least 60% by weight of the amphiphilic compound of formula A-B acting as solvent, so as to form an amalgam of oil or grease with compound A-B thanks to the radical A,

   then rinsing the surface of the water so as to eliminate the amalgam from the surface, this elimination being made possible by the hydrophilic nature of the amalgam due to the presence of the radical B.
2. Process according to claim 1, characterised in that the compound is an alkylsulphate, and alkylether sulphate, and nonylphenylether sulphate, a sulphosuccinate, a hemisulphosuccinate, an alkylbenzene sulphonate, an amino acid or protein derivative, an ethoxylated fatty alcohol, an ethoxylated fatty acid, an ethoxylated fatty ester, a sorbitan ester, an ethoxylated sorbinate ester, an ethoxylated alkylphenol, a fatty amide, a fatty ester, an oxyethylenated primary monoamine and an oxyethylenated diamine, a primary monoamine acetate, a diamine diacetate, a diamine dioleate, a quaternary ammonium salt, an amine oxide, an ether amine or an ether diamine.
3. Process according to claim 1, characterised in that the amphiphilic compound is an alkyleneglycol ether oxide of the formula

   

   wherein

   R₁ is a hydrogen atom or a hydrocarbon group, optionally substituted, having 1 to 20 carbon atoms, or a hydrocarbylcarbonyl group having 1 to 21 carbon atoms, R₂ is a hydrogen atom or a hydrocarbon group, optionally substituted, having 1 to 20 carbon atoms, at least one of R₁ and R₂ having at least 10 carbon atoms,

   R₃, R₄, R₅ and R₆, which may be identical or different, denote hydrogen or a hydrocarbon group, optionally substituted, having 1 to 6 carbon atoms, and n is an integer from 1 to 12.
4. Oily composition comprising an amphiphilic compound of formula A-B, wherein A is a lipophilic and hydrophobic radical and B is a hydrophilic radical and preferably an alkyleneglycol ether oxide as defined in claim 3, characterised in that the composition contains 60 to 75% by weight of the amphiphilic compound of formula A-B, 15 to 20% of water and 10 to 20% of an agent which promotes miscibility of the amphiphilic compound of formula A-B in water, in which in the agent which promotes the miscibility of the compound of formula A-B in water is a lower alcohol, diacetone alcohol, a glycol and/or a glycol ether oxide.