EP0629234B2 - Lubricants for chain belt conveyors and their use - Google Patents

Abstract

Chain conveyor lubricants, especially for the food industry, which form clear solutions in water and which contain in combinationa) at least one compound corresponding to formula (I): in whichR1 is a saturated or mono- or polyunsaturated, linear or branched alkyl group containing 6 to 22 carbon atoms, which may optionally be substituted by an -OH, -NH2, -NH-, -CO-, halogen or a carboxyl group,R2 is a carboxyl group containing 2 to 7 carbon atoms,M is hydrogen, alkali metal, ammonium, an alkyl group containing 1 to 4 carbon atoms or a benzyl group, andn is an integer of 1 to 6;b) at least one organic carboxylic acid selected from monobasic or polybasic, saturated or mono- or polyunsaturated carboxylic acids containing 2 to 22 carbon atoms; and, optionally,c) at least one of water, additives, and auxiliaries.

Description

The present invention relates to clear water soluble Containing chain conveyor lubricant amphoteric compounds of general Formula (I) and organic carboxylic acids and optionally Water and additives and / or auxiliaries.

The invention further relates to the use such combinations of lubricants as chain conveyor lubricants in the food industry. In particular, the inventive Lubricant here use for lubrication Cleaning and disinfecting automatic Chain conveyor belt systems used during filling of food, preferably beverages, in Glass and plastic bottles, cans, glasses, barrels, Beverage container (KEG), paper and cardboard containers and the like can be used.

In bottle cellars and barrel cellars of beverage companies as well as when filling food are used for the transportation of the appropriate Containers are usually plate conveyor belts or chain conveyor belts used with suitable aqueous lubricant preparations over Dip lubrication systems or automatic Belt lubrication systems lubricated and kept clean become.

Hardly any problems during splash lubrication systems with regard to the application properties prepare when choosing the lubricant, are precipitates of poorly soluble salts and microbiological deposits in the nozzles and filtering the central lubrication systems the continuous ones Operation of filling food especially disturb drinks can so that the plants after a certain Operating time must always be switched off and cleaned have to.

The chain lubricants previously used as lubricants are based on fatty acids in Form of their water-soluble alkali or alkanolamine salts or on fatty amines in the form of their organic or inorganic salts.

DE-A-23 13 330 describes side-based lubricants which contain aqueous mixtures of C ₁₆ -C ₁₈ fatty acid salts and surface-active substances.

In addition to these side-based lubricants are otherwise mainly based on used by primary fatty amines DE-A-36 31 953 a method for lubrication of chain-shaped bottle conveyor belts in Bottling plants, especially in breweries, and to clean the tapes using a liquid detergent, which is characterized is that you have the chain-shaped bottle conveyor belts with belt lubricants based neutralized primary fatty amines, the preferred Have 12 to 18 carbon atoms and an unsaturated Contain more than 10%, lubricates and the bottle conveyor belts with cationic Cleaning mine, namely quaternary Ammonium compounds such as alkyltrimethylammonium, Dialkyldimethylammonium and alkyldimethylbenzylammonium chlorides or organic Acids cleanses.

The main disadvantages of these fatty amines are: The Reaction with anions of water, in particular with sulfates, bicarbonates, phosphates and carbonates from alkaline water and others Water ingredients: a strong reaction with in Water dissolved carbonic acid to poorly soluble Ammonium carbonates, for example in the case of carbonated ones Drinks; it must inevitably Solubilizers are used; the cleaning of the spray and distribution system is regular Intervals necessary; otherwise clogged the entire system and is therefore unusable.

For lubricants based on primary fatty amines is not a continuous 24-hour operation possible. When using such primary The plant can use fatty amines as lubricants can only be driven with little flexibility or in many cases this method can be used do not use as often in existing systems Premix containers are available. The stake of primary fatty amines and the necessary ones two process steps - on the one hand Lubrication, on the other hand cleaning - require high capital investment costs. Finally results through the use of primary amines and the lower alkane carboxylic acids, such as Acetic acid required for the cleaning step are also a significant odor nuisance.

The main disadvantages of the above methods are on the one hand the strong water dependency the soap based lubricant and the System cleaning required on a regular basis of lubricants based on primary Amines. The precipitates in both processes of the prior art must occur be removed. Use one to remove simple acid-base reaction. In the case of soap products based on fatty acids, alkaline, detergents containing complex agents and as technical equivalents to this in products based on primary fatty amines organic or inorganic acids used as cleaners.

Finally, there are others in the prior art Chain lubricant known to the above Disadvantages described do not have. So describes EP-A-0 044 458 lubricant preparations, which are practically free of fatty acid soaps and which is also a carboxylated nonionic Contain surfactant and an acyl sarcosinate. The pH of these products is 7 to 11 and lies thus preferably in neutral to alkaline Area.

DE-A-38 31 448 finally relates to aqueous, clear water-soluble, soap-free lubricant preparations, a process for their manufacture and the use of the lubricant preparations according to the invention, especially as a lubricant for transporting glass bottles or polyethylene terephthalate bottles. The essentially neutral aqueous lubricant preparations (pH in the range from 6 to 8) contain alkylbenzenesulfonates, alkoxylated alkanol phosphates and alkane carboxylic acids, if necessary in addition to usual solubilizers, Solvents. Defoamers and disinfectants.

1. Sie sind mikrobiologisch ungünstig, da sie hervorragende Wachstumsbedingungen für Mikroorganismen schaffen.

2. Weiterhin zeigen sie nur eine geringe Reinigungskraft.

3. Schließlich weisen sie ein schwer zu kontrollierendes Schaumverhalten auf

However, these two products described above also show the following three shortcomings:

1. They are microbiologically unfavorable because they create excellent growth conditions for microorganisms.

2. Furthermore, they show only a low cleaning power.

3. Finally, they have a foam behavior that is difficult to control

DE-A-39 05 548 describes lubricants described having at least one secondary and or tertiary amine and or salts thereof Amines included in these conveyor belt hygiene products however showed up in practical Application certain problems because of some Cases of skin irritation observed this Products have been attributed and because of the formation of toxic secondary products if improper Handling (alkalization). This hydrophobic Connections are due to the low Network effect only in an optimal operating state Belt lubrication system can be used Through organic Soiling or acids, for example through phosphate entry, neutralization occurs of connections.

From US-A-3,574,100 are lubricant compositions known the amphoteric compounds included according to this document as N-fatty alkyl β-aminopropionate and N-fatty alkyl β-iminodipropionate be designated.

When using these connections in Lubricants, however, have had relatively high coefficients of friction notes. In addition, the clear water solubility for use in central lubrication systems in the food industry, in particular permanently installed automatic systems, not sufficient.

The present invention is therefore the object based on new, improved lubricant preparations, in particular clear water-soluble chain conveyor lubricants, to provide that do not have the disadvantages of the prior art. Such lubricants are said to be both good friction, so an excellent one Lubricating effect, low foaming behavior, a good cleaning effect and if possible one have good microbicidal activity.

a) 0,01 bis 95 Gew.-% wenigstens einer oder mehrerer Verbindungen der allgemeinen Formel (I)

wobei

R

für einen gesättigten oder einfach oder mehrfach ungesättigten, linearen oder verzweigten Alkylrest mit 6 bis 22 C-Atomen,

M

für Wasserstoff, Alkalimetall, Ammonium, einen Alkylrest mit 1 bis 4 C-Atomen oder einen Benzylrest und

n

für eine ganze Zahl im Bereich von 1 bis 6 steht,

b) 5 bis 50 Gew.-% wenigstens einer organischen Carbonsäure ausgewählt aus einbasigen oder mehrbasigen, gesättigten oder einfach oder mehrfach ungesattigten Carbonsäuren mit 2 bis 22 C-Atomen,

c) gegebenenfalls Wasser und Zusatz- und/oder Hilfsstoffe.

The present invention relates to clear water-soluble chain conveyor belt lubricants which have a pH in the range from 3 to 6, comprising in combination:

a) 0.01 to 95% by weight of at least one or more compounds of the general formula (I)

in which

R

for a saturated or mono- or polyunsaturated, linear or branched alkyl radical with 6 to 22 carbon atoms,

M

for hydrogen, alkali metal, ammonium, an alkyl radical with 1 to 4 carbon atoms or a benzyl radical and

n

represents an integer in the range from 1 to 6,

b) 5 to 50% by weight of at least one organic carboxylic acid selected from monobasic or polybasic, saturated or mono- or polyunsaturated carboxylic acids with 2 to 22 carbon atoms,

c) optionally water and additives and / or auxiliaries.

By combining amphoteric surfactant and organic carboxylic acid became a chain conveyor lubricant with excellent Get properties. The lubricating effect with Coefficient of friction of µ was less than or equal to 0.12 compared to the amphoteric compounds alone clearly improved.

The setting of a skin pH of the application solution is possible. The invention Chain conveyor belt lubricants are independent on water quality. At usual use concentrations are the lubricant combinations only slightly foaming. Particularly good ones Properties were used when assessing the emergency running properties observed. The ingredients are readily biodegradable and have a good cleaning effect on.

With regard to their application properties show the lubricant combinations according to the invention a very good coefficient of friction, a low one Foaming behavior, a good cleaning effect as well as good skin tolerance. In addition to the positive properties mentioned are the following Boundary conditions met: moderate foaming behavior improves lubrication in problem areas, such as turntables, changers, etc .; high substantivity and therefore high lubrication performance too unfavorable operating conditions (e.g. belt lubrication): low toxicity: generally applicable even with device deficiencies: good cleaning effect; high capillary activity and Film formation on surfaces; even in the present of organic pollution and acids or alkalis effective and also non-corrosive as a concentrate: insensitive to a drink entry.

The lubricant combinations according to the invention are used in the beverage industry in contrast to the chain lubricants previously used both regardless of water quality as well as low foam, stable in storage at depths Temperatures, non-corrosive and special environmentally and skin compatible.

Which in the sense of the present invention using compounds of the general formula (I) can be one of the following as radical R: mentioned alkyl radicals contain: hexyl, heptyl, octyl, Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl Pentadecyl, hexadecyl, heptadecyl, octadecyl, Nonadecyl, Eicosyl, Heneicosyl or Docosyl. They come in the same way corresponding mono- or polyunsaturated Residues or the corresponding branched Isomers in question. According to the invention such compounds are preferred of the general formula (I), which is the radical R a straight chain, saturated or unsaturated Alkyl radical with 8 to 18 carbon atoms, especially with 10 to 18 carbon atoms.

The index "n" in the general formula (I) means an integer ranging from 1 to 6. The group in question is therefore Methylene, ethylene, propylene, butylene, pentylene or Hexylene residues, where the values n = 2 and n = 3 are preferred. Special importance comes the ethylene residue (n = 2). According to the invention it is further preferred that M is hydrogen or an alkali metal atom, being used as alkali metals Sodium or potassium, especially sodium, preferably come into question.

Mixtures of compounds of the general formula (I) can of course also be used for the purposes of the invention. Examples of the compounds of formula (I) to be used according to the invention are: sodium N-lauryl iminodipropionate. Sodium N-cocoalkylimino dipropionate or sodium N-oleyl imanodipropionate. Such compounds can be prepared analogously to the information in US Pat. No. 3,574,100. Such compounds are also commercially available, for example compare DE-RIPHAT ^R 160C from Henkel KGaA.

The selection of the organic carboxylic acid (s) is less critical as long as the clear water solubility ensured under the given circumstances is. Accordingly, there is a preferred one Embodiment of the present invention in that the organic carboxylic acid is selected from Acetic acid, citric acid and glycolic acid, where acetic acid is of particular importance.

The chain conveyor belt lubricant contain 0.01 to 95% by weight of the prebindings of the general formula (I) and 5 to 50 wt.% dor organic carboxylic acids. So it is possible that the chain conveyor lubricant in this Form can be obtained anhydrous. In a particularly preferred embodiment of the present invention contain the chain conveyor belt lubricants 5 to 25% by weight of the compounds of the general formula (I) and 10 to 15% by weight of the organic carboxylic acids. As additional ingredients of the invention Chain conveyor lubricants come alongside Water optionally further additional and / or Excipients in question.

As additives for the invention Lubricant combinations come first secondary and / or tertiary amines and / or Salts of such amines into consideration as in the DE-A-39 05 548 described above are.

If desired, the inventive Lubricants also include N-fatty alkyl beta aminopropionates included as in the above cited US-A-3,574,100. In this The connection is also EP-A-0 372 628, in which also corresponding N-alkyl aminocarboxylic acids in broader Form to be revealed. Such connections too may come as additives for the lubricants of the invention in question.

The amount of such additives, if any the lubricants according to the invention can usually be added to the Range from 0 to 10 wt .-%, preferably in Range from 1 to 5 wt .-%, each based on the overall wording.

Furthermore, the invention Lubricant combinations as auxiliary agents, solubilizers to obtain a homogeneous, clear water soluble Application solution included. As for example, alcohols, Polyalcohols, ethers or polyethers, in particular Isopropanol, butyl glycol, butyl diglycol or ethylene glycol ether. The amount of to use Solubilizer is used in individual cases the betaine used, the specialist is in In individual cases the required amount of solubilizer determine by trying. In general are additions to solution brokers in the field from 1 to 20% by weight. based on the overall formulation, sufficient.

Other auxiliary substances within the meaning of the present invention are also anionic or nonionic surfactants, for example alkoxylated fatty amines, fatty alcohols, alkoxylated fatty alkols, but also alkylbenzenesulfonates soluble in hydrophilic solvents. These surfactants can improve the wetting of the chains and plate conveyor belts, should this be necessary in individual cases. In general, surfactant additives in the range from 1 to 10% by weight, based on the total formulation, are sufficient for this. Nonionic surfactants are preferred, preferably fatty alcohol / ethylene oxide / propylene oxide adducts, in particular C _12/14 fatty alcohol-5EO-4PO- Adducts.

Biocidal active substances are also suitable as further auxiliaries for the purposes of the present invention. According to the invention, quaternary ammonium compounds (QAC) in particular are used as such which have at least one long-chain alkyl radical with in particular 8 to 16 carbon atoms and / or at least one benzyl radical which is optionally substituted by halogen atoms. Cocasalkyl-dimethyl-benzyl-ammonium chloride may be mentioned here by way of example (DODIGEN ^R 226. Commercial product from Bayer AG). In this connection, compounds of the alkyl-aminoethylene-glycine type which have an alkyl radical with 6 to Have 22 carbon atoms, in particular 10 to 16 carbon atoms, and preferably two aminoethylene groups. Such types of compounds are also called TEGO ampholytes and are, for example, commercial products from Goldschmidt AG. An example is [N-dodecyl-bis (aminoethylene)] - N'-glycine. (TEGO ^R 51B, Goldschmidt AG). Such biocidal active ingredients are generally added to the lubricants according to the invention in amounts of 0 to 10% by weight, in particular in amounts of 1 to 5% by weight, based in each case on the total formulation.

If necessary, the invention Lubricants as other auxiliary substances too Defoamers can be added. As such come for example addition products of ethylene oxide and propylene oxide on fatty alcohols as well especially end-capped fatty alcohol polyethylene glycol ethers in question.

The lubricant combinations according to the invention have a pH in the range from 3 to 6. If the pH of the Chain conveyor belt lubricant not already in this range, he can by adding a Acid, preferably an organic carboxylic acid, as defined above, for example with acetic acid set to the desired value become.

With regard to an optimal dosing option it is also advantageous that the lubricant combinations a dynamic viscosity of less than 300 mPa.s, especially less than 150 mPa.s and particularly preferred in the range from 5 to 100 mPa.s - each at 20 ° C. A separate adjustment of the viscosity the stated values are generally not required or, if necessary, by addition appropriate amounts of the preferred diluent Water or a solubilizer.

If the lubricants according to the invention not exclusively from compounds of the general Formula (I) and organic carboxylic acids consist of simple mixing these components with water, if necessary with the addition of the additional and / or Auxiliary materials.

Finally, the present invention relates the use of chain conveyor lubricants of the type described above Lubricant in the food industry, in particular for automatic chain conveyor systems. For this purpose, the Chain conveyor belt lubricant according to the invention generally still diluted with water. Contain such aqueous application solutions in the shelf 0.01 to 1 wt .-% of compounds of the general formula (I), preferably 0.01 to 0.2% by weight and in particular 0.02 to 0.04% by weight of such connections. The ones to be used Amounts of organic carboxylic acid result by simply converting the quantities the concentrates from the amount of compounds of the general formula (I).

The products of the invention cause unlike standard soap products, none Stress corrosion cracking and can therefore be used for PET and PC containers can be used without any problems. (PET = polyethylene terephthalate, PC = polycarbonate), provided no surfactants are used as auxiliary substances find that with such materials too Lead tension cracks.

Examples

The present invention is illustrated by the following Examples explained in more detail. The invention Examples 1 to 9 show formulations of lubricant concentrates as well as various application data with the corresponding dilute aqueous application solutions were determined, these application solutions the respective concentrates in a quantity of 0.4 wt .-% contained. Further explanations to the respective application technology Data - frictional resistance. Foaming behavior. Clear water solubility and emergency dew time - can be found below. The comparative examples serve for comparison 1 to 5.

All percentages in the following Formulation examples relate to percentages by weight.

Flaschentransportgeschwindigkeit: ca 1 m/s

Besprühen des Flaschentransportbandes mit 0,4 Gew.-%iger Bandschmiermittellösung, wie in den Beispielen genannt.

Sprühleistung der Düsen: 4 l/h, 1 Düse pro Band.

The tests for measuring the frictional resistance, hereinafter referred to as "coefficient of friction", were carried out on a pilot bottle conveyor belt under the following conditions: Measurement of the frictional resistance of 20 0.5 l Euro beer bottles filled with water as tensile stress using a dynamometer.

Bottle transport speed: approx. 1 m / s

Spraying the bottle conveyor belt with 0.4% by weight belt lubricant solution, as mentioned in the examples.

Spraying performance of the nozzles: 4 l / h, 1 nozzle per belt.

The coefficient of friction "µ" given below results as the quotient of the measured tensile stress for a bottle to the weight of the bottle in grams.

Furthermore, the products were made with hard water (16d) according to the provisions of DIN 53 902 tested.

0 = schaumfrei

1 = vereinzelte Schaumblasen

2 = geringes Schäumen, nicht störend

3 = Schäumen, störend

4 = starkes Schäumen, nicht akzeptabel, Schaum unter dem Band.

The foam behavior is assessed according to the following classes:

0 = foam-free

1 = isolated foam bubbles

2 = low foaming, not disturbing

3 = foaming, disturbing

4 = strong foaming, not acceptable, foam under the tape.

The coefficient of friction should be sufficient Lubrication is less than 0.15 of 0.15 leaves the lubrication and thus the perfect transportation significantly.

The clear water solubility of the application solutions should also be used over a longer trial period be guaranteed to keep deposits in Ball valve filters, nozzles, spray and distribution system, Avoid belt and cargo. This was done a 0.4 wt .-% solution in 16 · d water stored for 72 h and then assessed visually.

The foam development should be low because Excessive foam doesn't just work (automatic bottle inspector) and occupational safety (Danger of slipping), but beyond also soften the label and put it in that unclosed vessels can penetrate. In addition the coefficient of friction becomes due to excessive foaming tendency worsened. A low level of foaming is an advantage because it is a better one Distribution of the lubricant on the conveyor belts conditionally.

Under experimental conditions, which are also used to determine the coefficient of friction and the foaming behavior were used after a term the chain conveyor lubricant is metered in from 30 min switched off. From now on the bottles are only replaced by adhering chain conveyor lubricant lubricated. It the time was measured in which the lubrication without significant deterioration in the coefficient of friction was maintained. The end of the attempt Was determined by if the coefficient of friction by 20% compared to the original value had decreased.

example 1

15% sodium N-lauryl iminodipropionate

14% acetic acid

71% water

Coefficient of friction: µ = 0.10, foam behavior = 2

Clear water solubility: almost clear

Emergency time: 20 min

Example 2

15% sodium N-lauryl iminodipropionate

14% acetic acid

68% water

3% C _12-14 fatty alcohol with 5EO / 4PO

Coefficient of friction: µ = 0.10, foam behavior = 1

Clear water solubility: absolutely clear

Emergency run time: 25 min

Example 3

15% sodium N-lauryl iminodipropionate

13% citric acid

72% water

Coefficient of friction: µ = 0.11, foam behavior = 2

Clear water solubility: almost clear

Emergency run time: 15 min

Example 4

15% sodium N-lauryl aminodipropionate

10% glycolic acid

75% water

Coefficient of friction: µ = 0.11, foam behavior = 1

Clear water solubility: almost clear

Emergency runtime: not examined

Example 5

86% sodium N-lauryl iminodipropionate

14% acetic acid

Coefficient of friction: µ = 0.10, foam behavior = 1

Clear water solubility: almost clear

Emergency run time: 20 min.

Example 6

15% sodium N-lauryl iminodipropionate

14% acetic acid

68% water

3% cocoalkyl-dimethyl-benzyl-ammonium chloride

Coefficient of friction: µ = 0.10, foam behavior = 1

Clear water solubility: absolutely clear

Emergency run time: 25 min

Example 7

15% sodium N-lauryl iminodipropionate

14% acetic acid

68% water

3% [N · docecyl-bis (aminoethylene] -N'-glycine

Coefficient of friction µ = 0.10, foam behavior = 1

Clear water solubility absolutely clear

Emergency run time: 20 min

Example 8

15% sodium N-coconut iminodipropionate

14% acetic acid

68% water

3% coco-dimethyl-benzyl-ammonium chloride

Coefficient of friction: µ = 0.12, foam behavior = 0

Clear water solubility: absolutely clear

Emergency run time: 20 min

Example 9

15% sodium N-Cacos iminodipropionate

1% sodium N-oleyl iminodipropionate

14% acetic acid

68% water

3% coco-dimethyl-benzyl-ammonium chloride

Coefficient of friction: µ = 0.11, foam behavior = 0

Clear water solubility: absolutely clear

Emergency run time: 20 min

Comparative Example 1: (Lateral chain lubricant)

59% water

10% butyl diglycol

15% fatty acid (oil / linole)

9% ethylenediaminetetraacetate-Na4

4% monoethanolamine

3% potassium hydroxide

Coefficient of friction: µ = 0.12, foam behavior: 3-4

Clear water solubility: with 1% use until 12.5

· D clearly water soluble

Emergency run time: 5 min

Comparative Example 2 : (alkylamine-based chain lubricant)

4% N, N-dimethyl-N-laurylammonium acetate

8% lauryl propylene diammonium acetate

88% water

Coefficient of friction: µ = 0.10, foam behavior = 1

Clear solubility: opaque

Emergency running time: approx. 7 min

Comparative Example 3 (U.S. Patent 3,574,100)

15% N-cocoalkyl aminopropionic acid

85% water

Coefficient of friction: µ = 0.14, foam behavior = 2

Clear solubility: opaque

Emergency run time: 10 min

Comparative Example 4 (U.S. Patent 3,574,100)

15% N-cocoalkyl aminopropionic acid

3% lauryl ether phosphoric acid ester

82% water

Coefficient of friction: µ = 0.13, foaming behavior = 4

Clear water solubility: opaque

Emergency run time: 7 min

Comparative Example 5:

15% sodium N-lauryl iminodipropionate

85% water

Coefficient of friction: 0.12, foaming behavior = 2

Clear water solubility: opaque

Emergency run time: 15 min

Claims (9)

1. Chain conveyor lubricants forming clear solutions in water with a pH of 3 to 6 containing in combination

   a) 0.01 to 95% by weight of at least one or more compounds corresponding to general formula (I):

   

   in which

   R

   is a saturated or mono- or polyunsaturated, linear or branched alkyl group containing 6 to 22 carbon atoms,

   M

   is hydrogen, alkali metal, ammonium, an alkyl group containing 1 to 4 carbon atoms or a benzyl group and

   n

   is an integer of 1 to 6,

   b) 5 to 50% by weight of at least one organic carboxylic acid selected from monobasic or polybasic, saturated or mono- or polyunsaturated carboxylic acids containing 2 to 22 carbon atoms,

   c) optionally water and additives and/or auxiliaries.
2. Lubricants as claimed in claim 1, characterized in that n = 2 or 3, more particularly 2.
3. Lubricants as claimed in claim 1 or 2, characterized in that R in general formula (I) is a linear, saturated or unsaturated alkyl group containing 8 to 18 carbon atoms and more particularly 10 to 18 carbon atoms.
4. Lubricants as claimed in one or more of claims 1 to 3, characterized in that the carboxylic acid is selected from acetic acid, citric acid and glycolic acid, preferably acetic acid.
5. Lubricants as claimed in one or more of claims 1 to 4 containing 5 to 25% by weight of the compounds corresponding to general formula (I) and 10 to 15% by weight of the organic carboxylic acid.
6. Lubricants as claimed in one or more of claims 1 to 5, characterized in that they contain solubilizers, nonionic or anionic surfactants, biocides and/or foam inhibitors as auxiliaries.
7. Lubricants as claimed in claim 6, characterized in that they contain quaternary ammonium compounds and/or alkyl aminoethylene glycines as biocides.
8. Lubricants as claimed in one or more of claims 1 to 7, characterized in that they have a dynamic viscosity of less than 300 mPa.s and more particularly in the range from 5 to 100 mPa.s, as measured at 20°C.
9. The use of the lubricants claimed in one or more of claims 1 to 8, preferably in the form of dilute aqueous solutions, as chain lubricants in the food industry, more particularly for automatic chain conveyor installations.