[0002] In the food industry, in particular in beverage plants, the containers that are to be filled in the filling plants are transported by means of conveyors in a wide variety of designs and materials, for example by means of apron conveyors or chain-type arrangements, which will be referred to in general terms below as conveyor chains. The conveyor chains are made of different materials, i. e. plastic or metal. The conveyors link the various optional treatment stages of the filling process, such as e. g. unpacker, bottle washing machine, filler, sealer, labeler, packer, etc. The containers can come in a wide variety of forms, in particular glass and plastic bottles, cans, jars, casks, drink containers (KEG), paper and cardboard containers. To ensure that the operation proceeds smoothly, the conveyor chains must be lubricated by suitable means such that excessive friction on the contain- ers is avoided. Diluted aqueous solutions containing suitable antifriction agents are conventionally used for lubrication. The conveyor chains are brought into contact with the aqueous solutions by immersion or spraying, for example, whereby refer- ence is then made to splash lubrication plants or automatic belt lubrication sys- tems.

[0003] In order to minimize the abrasion of the chains, a lubricant is applied to the surface of the chains, whereby the friction coefficient of the chain with the container should not exceed a specific value. Otherwise the chain will be damaged involving further costs. Moreover, the container can fall down on the chains during transportation which will result in ceasing of filling said container since such bottles and cans have to be removed manually. Thus, a reliable lubrication of the chains with the lubricant used is very important.

[0004] The chain lubricants that have been used so far and are still used today as lubricating agents for conveyor belt systems are mainly based on fatty acids in the form of their water-soluble alkali or alkanol amine salts or on fatty amines, preferably in the form of their organic or inorganic salts, i. e. their acetates.

Such lubricants are for example described in DE-A-36 31 953, EP-A-0 372 628, DE-A-39 05 548, DE-A-42 06 506, and WO 94/03562.

[0005] Also, amine-free lubricants are known and described for example in WO 03/027217 A1. This document relates to the use of an oil-in-water emulsion for lubricating a conveyor belt system. It contains wax esters, like cetyl palmitat, hydrogenated castor oil, glyceryl stearate, ethoxylated behenyl alcohol, formic ac- ids and betaines as zwitterionic amphoteric surfactants.

[0006] From the point of view of the user, however, the chain lubricants used still present the problem that they either adhere too poorly to the chains or attach too. strongly to the chains.

[0007] Where chain lubricants adhere too poorly to the chains they drip onto the ground soon after application, with the result that the lubricating effect on the chains, which are several meters in length, is extremely dependent on the proxim- ity to the metering point. The same problem occurs at places where there is a risk of the lubrication film rapidly being removed from the surface by spilled beverage.

The consequence is that very different qualities of lubrication can occur from one section to another. In critical sections this commonly leads to bottles falling over and even to interruption of the filling operation.

[0008] Where chain lubricants adhere very well to the chains, as is the case with fluoro groups containing surfactants, for example, which have very good wet- ting properties, a firmly adhering film is formed on the conveyor chains, which cannot easily be removed by rinsing with water.

[0009] Residues and abraded material can collect in this film and lead to hygiene problems and breakdowns in operation.

[0010] Generally, container are made of glass or a plastic material such as a polyester. Poly (ethylene terephthalate) (PET) is very often used to manufacture plastic bottles.

[00111 In case that glass bottles are transported the lubrication of the com- position according to the state of the art is not sufficient. Glass bottles can fall off the conveyor chain and thus a secure transportation of glass bottles can not be assured. Furthermore, due to an insufficient lubrication the abrasion of the chains used is not acceptable.

[0012] Other lubricants known in the prior art show a similar behavior. They are either suitable as lubricant for transporting container made of a plastic material or container made of glass. None of the compositions known in the prior art are capable of serving as lubricant in a bottling plant for all types of container material such as glass bottles, plastic bottles as well as cans.

[0013] For convenience reasons a manufacturer of for instance beverage wants to fill all kinds of containers like glass bottles, plastic bottles as well as cans with the same bottling plant. At present he has to use a specific lubricant for each type of container to be filled. Thus, further costs and a significant downtime of the bottling plant are due to the specific selection or exchange of lubricants for each type of container to be filled.

[0014] The technical problem underlying the present invention is the provi- sion of a lubricant suitable for container such as bottles made of glass, bottles made of a plastic material such as polyester or cans in a bottling plant, whereby the chains used in the bottling plant may be made of a metal and/or a plastic mate- rial. Furthermore, the lubricant shall provide good adhesion to the chains, display

good lubricating properties and shall form a film on the chains that can easily be removed, if necessary.

[0015] The technical problem underlying the present invention is solved by a concentrate for use as chain lubricant comprising: a) at least one ester selected from the group consisting of monoesters and diesters represented by the aa) general formula (1) R1-COOR2 (1) ab) general formula (2) R1OOC-R3-COOR2 (2) ac) general formula (3) R1-COOR3OOC-R2 (3), and mixtures thereof, whereby R1 is a C1-C22-alkyl group or a C8-C22-alkenyl group, R2 is a C1-C22-alkyl group or a C8-C22-alkenyl group, R1 and R2 being the same or a different, R3 is a C2-C16-alkylene group, and the sum of carbon atoms present in R', R2 and R3 of each monoester or diester being at least 10, and b) at least one anionic surfactant.

[0016] Preferably, R1 is an alkyl group having 1,2, 3,4, 5,6, 7,8, 9,10, 11, 12,13, 14,15, 16,17, 18,19, 20,21 or 22 carbon atoms or R1 is an alkenyl group having 8,9, 10,11, 12,13, 14,15, 16,17, 18,19, 20,21, or 22 carbon atoms.

[00171 Preferably, R 2 is an alkyl group having 1,2, 3,4, 5,6, 7,8, 9,10, 11, 12,13, 14,15, 16,17, 18,19, 20,21 or 22 carbon atoms or R2 is an alkenyl group having 8,9, 10,11, 12,13, 14,15, 16,17, 18,19, 20, 21, or22 carbon atoms.

[0018j Preferably R3 is an alkylen group having 2,3, 4,5, 6,7, 8,9, 10,11, 12,13, 14,15, or 16 carbon atoms.

[0019] Preferably, the concentrate further comprises at least one amphoteric surfactant.

[0020] In a preferred embodiment the sum of carbon atoms present in R', R2 and R3 of each monoester or diester is at least 12, even more preferred at least 15, and most preferred at least 20.

[0021] The concentrate may be an emulsion or microemulsion being pref- erably an oil-in-water or a water-in-oil emulsion.

[0022j Preferably, the concentrate comprises 0,001 to 20 wt.-% of the ester and/or 0,001 to 20 wt. -% of the anionic surfactant and/or 0,001 to 20 wt. -% of the amphoteric surfactant, whereby optionally the balance is a liquid being preferably water.

[0023] In a preferred embodiment 0,01 to 15 wt-% of the ester is present in the concentrate. Preferably, 0,1 to 12 wt.-%, even more preferred 0,15 to 10 wt.- %, preferably 0,2 to 8 wt. -% and even more preferred 0,25 to 6 wt. -% of the ester is present in the concentrate.

[0024] Preferably, 0,01 to 15 wt. -%, even more preferred 0,1 to 12, wt.-%, preferably 0,15 to 10 wt. -%, even more preferred 0,2 to 8 wt. % and most pre- ferred 0,25 to 6 wt-% of the anionic surfactant is present in the concentrate.

[0025] Preferably, 0,01 to 15 wt.-%, even more preferred 0,1 to 12, wt.-%, preferably 0,15 to 10 wt. -%, even more preferred 0,2 to 8 wt. % and most pre- ferred 0, 25 to 6 wt-% of the amphoteric surfactant is present in the concentrate.

[0026] The ester is preferably selected from the group consisting of methyl ester or isopropyl ester of fatty acids having 12 to 22 carbon atoms, methyl laura- te, methyl stearate, methyl oleate, methyl erucate, isopropyl palmitat, isopropyl myristate, isopropyl stearate, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl palmitat, isononyl isononanoate, 2-ethylhexyl palmita- te, 2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitat, oley oleate, oleyl erucate, erucyl erucate, cetyl palmitat, beheneth-10, esters of tech- nical aliphatic alcohol mixtures with technical aliphatic carboxylic acids, esters of saturated and/or unsaturated fatty alcohols having 12 to 22 carbon atoms with saturated and/or unsaturated fatty acids having 12 to 22 carbon atoms, naturally occurring monoester or waxy ester mixtures as occurring in jojoba oil or sperm oil, di-n-butyl adipate, di-n-butyl sebacate, di- (2-ethylhexyl) adipate, di- (2-hexyldecyl) succinate, di-isotridecyl acealate, ethylenglycol dioleate, ethylenglycol-di- isotridecanoate, propyleneglycol-di- (2-ethylhexanoate), butanediol-di-isostearate, neopentylglycol-di-caprylate and mixtures thereof.

[0027] The anionic surfactant is preferably selected from the group consist- ing of sulfonate salt, alkali sulfonate salt, alkyl benzene sulfonic acid, alkali alkyl benzene sulfonate, alkyl sulfonic acid, alkali alkyl sulfonate, alkali alkyl sulfate, alkali alkenyl sulfate, fatty acid ether sulfate, fatty alcohol sulfonate, secondary alkane sulfonate sodium salt and mixtures thereof.

[0028] The amphoteric surfactant is preferably selected from the group consisting of ampholyte, betaine, alkylbetaine, N-alkylbetaine, glycinate, am- phoacetate, amphodiacetate, hydroxysultaine, amine oxide, lecithine, carboxyclic acid, sphingomyceline, amino alkene acid, sodium alkyl iminopropionate and mix- tures thereof.

(0029) Optionally, the concentrate further comprises at least one glyceride selected from the group consisting of triglyceride, diglyceride, monoglyceride, fatty acid triglyceride of fatty acids having 8 to 22 carbon atoms, glyceryl stearate and mixtures thereof. The glycerides can be naturally occurring vegetable oils such as olive oil, raps seed oil, sunflower oil, soy oil, peanut oil, almond oil, palm kernel oil or the fluid part of coconut oil or palm kernel oil. Moreover the glycerides can be of animal occurrence. In a preferred embodiment the glycerides are castor oil, prefer- rably hydrogenated castor oil. Preferably, the mono and diesters and glycerides as oily components of the composition according to the present invention are liquid at a temperature of 20 °C. It is also possible that higher melting fats and esters of the general formulae (1), (2) or (3) as given above are used in an amount so that the mixture of the oily compounds is liquid at a temperature of 20 °C.

/U03Q/Preferably, the concentrate according to the present invention com- prises of from 0,015 to 15 wt. -% of the glyceride.

[0031] Preferably, 0,05 to 10 wt-%, even more preferred 0,1 to 5 wt.-%, even more preferred 0,2 to 3 wt. -% and most preferred 0,3 to 2 wt. -% of the glyc- eride is present in the concentrate.

[0032] In a preferred embodiment the concentrate further comprises a hy- drocarbon oil, whereby preferably 0,01 to 15 wt. -% of the hydrocarbon oil, more preferred 0,015 to 10 wt. -%, even more preferred 0,05 to 5 wt. -%, most preferred, 0,1 to 3 wt. -% of the hydrocarbon oil is present in the concentrate. In a further preferred embodiment 0,2 to 2 wt. -% and even more preferred 0,3 to 1,5 wt. -% of the hydrocarbon oil is present in the concentrate.

[0033] The concentrate may comprise at least one further emulsifier being different from the compounds as defined above.

/U034/Preferably, the emulsifier is selected from the group consisting of nonionic emulsifier, ethylene oxide adducts with fatty alcohols having 16 to 22 car-

bon atoms, partial esters of polyols having 3 to 6 carbon atoms with fatty acids having 14 to 22 carbon atoms and mixtures thereof.

/U035/ In case the further emulsifier is present in the concentrate according to the present invention, preferably 0,005 to 20 wt. -% of the emulsifier is present in the concentrate. Preferably 0,01 to 15 wt. -%, more preferred 0,025 to 10 wt.-%, even more preferred 0,05 to 5 wt. -% and most preferred 0,075 to 3 wt-% of the emulsifier is present in the concentrate.

[0036] The concentrate may comprise a further co-emulsifier, whereby the co-emulsifier is preferably of the type of a saturated fatty alcohol having 16 to 22 carbon atoms and/or a partial ester of polyols having 3-6 carbon atoms with a fatty acid having 14 to 22 carbon atoms.

[0037] The concentrate may further comprise at least one additive selected from the group consisting of disinfectant, preservative, thickener, solubilizer, antifoaming agent, corrosion inhibitor, alkaline substance, sequestering agent, complexing agent and mixtures thereof.

[0038] Preferred preservatives are formic acid, benzoic acid, and peracetic acid.

[00391 Another suitable additive is preferably glyceride stearate, glycerine diglycerine, a diglycerine monoester, a glycerine diester, glycerine and mixtures thereof.

[0040] A preferred disinfectant is selected from the group of alcohols, alde- hydes, antimicrobial acids, carboxylic acid esters, acid amides, phenols, phenol derivatives, biphenylenes, biphenyl alkanes, urea derivatives, oxygen acetales, nitrogen acetales, oxygen formales, nitrogen formales, benzamidines, isothi- azolines, phthalimide derivatives, pyridine derivatives, antimicrobial surface active compounds, guanidines, antimicrobial amphoteric compounds, quinolines, 1,2-

dibromo-2,4-dicyano butane, iodo-2-propynyl-butyl-carbamate, iodine, iodophores, peroxides, peracids, peracetic acid, C102, quatenary ammonium compounds, glu- coprotamine and mixtures thereof.

[0041] The present invention is directed further to a lubricant solution com- prising the concentrate as defined above and a suitable diulent.

[0042] The diluent is preferably water and a degree of dilution of the con- centrate with water is preferably of from 1: 20 to 1: 5. 000. In another preferred em- bodiment the degree of dilution of the concentrate with water is of from 1: 30 to 1: 2000, more preferred 1: 40 to 1: 1000 and most preferred 1: 50 to 1: 500.

[0043] The concentrate or the lubricant solution according to the present invention can be used as a lubricant.

[0044] Preferably, a chain being preferably a part of a bottling plant which is preferably a conveyer chain or a conveyer belt is lubricated with the concentrate or lubricant solution according to the present invention.

[0045] In a preferred embodiment the chain has an outer surface comprising a metal and/or a plastic material. With said chain container such as bottles and/or cans are transported.

[0046] In case that container such as bottles are transported with the chain, the container or bottles are preferably made of glass or a plastic material, being preferably a polyester such as poly (ethylene terephthalate) or polycarbonate, poly (ethylene naphthenate) or polyurethane. Preferably, the container such as cans are made of a metal. It is preferred that the bottle is a refillable bottle being preferably a refillable plastic bottle such as a refillable poly (ethylene terephthalate) bottle (REFPET).

[0047] Preferably, when transported with the chain the container being pref- erably bottles and/or cans are empty or filled with preferably food or beverage [0048] Preferably, the concentrate or lubricant solution is used as antistatic agent.

[0049] A further object of the present invention is the provision of a process of conveying container being preferably bottles and/or cans on a chain being pref- erably a conveyer chain or a conveyer belt, whereby the concentrate or lubricant solution is applied to the chain, preferably on the area of the chain with which the container being preferably bottles and/or cans are transported.

[0050] The concentrate or lubricant solution can be applied to the chain by application means customary to a person skilled in the art. Preferably, the con- centrate or lubricant solution is sprayed to the chain by means of a nozzle or ap- plied by immersion of the chain. Alternatively, the concentrate or lubricant solution can be applied to the bottom of the container to be conveyed. This can be done by spraying or immersing the bottom of the container in the concentrate or lubricant solution.

[0051] In a preferred process, the concentrate or lubricant solution is not applied continuously but periodically to the chain. Preferably, for each period the time in which the concentrate or lubricant solution is applied to the chain is shorter than the time in which no concentrate or lubricant solution is applied to the chain.

Preferably, the time in which no concentrate or lubricant solution is applied to the chain is twice as long, preferably three times as long, more preferred four-times as long and most preferred five times as long as the time in which the concentrate or lubricant solution is applied to the chain. Preferably, for each period the sum of the time in which the concentrate or lubricant solution is applied to the chain with the time in which the concentrate or lubricant solution is not applied to the chain is less than 10 minutes, more preferred less than 8 minutes, even more preferred less than 6 minutes and most preferred less than 4 minutes.

[0052] The concentrate and lubricant solution according to the present in- vention is superior compared with the compositions known in the prior art. Due to an extremely high lubricant persistency on the chains such as conveyor chains or conveyor belts compared with conventional state of the art techniques the lubri- cant dosage can be adjusted very flexibly to approximately 1 minute dosage and 5 minutes pause. The frequency of dosing can be extended according to the cus- tomer's condition and demands to a wider time frame or to a combination of lubri- cation dosage, followed by pure water dosage until the lubrication film is used up.

[0053] Unexpectedly, the concentrate and lubricant solution according to the present invention has an excellent emergency lubrication behavior, which means that a dried lubrication film is capable of lubricating sufficiently. Moreover, a dried lubrication film can be reanimated only with a small amount of water.

[0054] Advantageously, the formulations according to the present invention are foam-free or very low on foam so that very high use-concentrations during the application are possible.

[0055] In a preferred embodiment a cleaning and/or disinfecting substance can be integrated into the concentrate or lubricant solution.

[0056] A further advantage of the concentrate and lubricant solution ac- cording to the present invention is that the lubricant comprises compounds only which are compatible with milk, soft-drinks and beer.

[0057] Due to the flexible dosage concept, the new concentrate and lubri- cant solution offers an environmentally favorable concept with significant lubricant and water savings up to 70 to 80 % which influences also, to a large extent, waste water treatment costs and provides energy saving opportunities.

[0058] Unexpectedly, there is no influence of the water hardness on the ca- pability of the concentrate and lubricant solution according to the present invention

over a wide range of water hardnesses, i. e. between 0° and 25° German hard- ness.

[0059] The new concentrate and lubricant solution according to the inven- tion displays a new range of amine free lubricants for all kind of containers and is suitable for plastic and metal conveyors. It can be applied as a one part solution with integrated disinfectants as well as a two component system in combination with a disinfecting product. The lubrification is excellent compared to the known amine acetate lubricants. Furthermore, when using the product according to the invention in the case of PET bottles and plastic container reduced stress cracking is observed. The lubricant has high water hardness and ion compatibility.

[0060] The following examples describe the invention in more detail without limiting it to the specific scope mentioned in the examples.

Examples 1. Preparation of the concentrate and lubricant solution The concentrate was manufactured by mixing the ingredients given in table 1 ac- cording to methods known to a person skilled in the art. First, Lamesoft PW 45 BENZ, the alkyl betaine and the secondary alkane sufonate sodium salt are mixed.

Subsequently water is added and the obtained solution is stirred. At last formic acid is added under stirring. Optionally, the concentrate can be filtered at any step of production of the concentrate.

Table 1 Compound Parts by weight [wt-%] Lamesoft PW 45 BENZ1) 6 alkyl betain, amphoteric surfactant 2 secondary alkane sufonate sodium salt, anionic surfactant 2,4 Formic acid 0,2 Water rest

1) Lamesofto PW 45 BENZ was purchased from Cognis Deutschland GmbH & Co. KG and is produced according to the teaching of EP 0 345 586, (emulsion of nonionic wax-like constituents and emulsifier comprising >20-40 wt-% cetyl palmitat, >5-10 wt-% beheneth-10, >1-5 wt-% hydrogenated castor oil, >1-5 wt-% glyceryl stearate, > 40-70 wt-% water, 0,2 wt-% benzoic acid). Alterna- tively, Lamesofto PW 45 can be used (same composition as Lamesoft PW 45 BENZ with the exception that formic acid is present instead of benzoic acid) The concentrate according to table 1 was diluted with water in a ratio of concen- trate to water of 1: 333 (0,3 wt-% of the concentrate in water) to obtain a lubricant solution for use as lubricant in the test run.

2. Test run in a bottling plant The obtained lubricant solution was applied to a conveyor chain of a bottling plant by means of a nozzle. The bottling plant had a conveyer chain made of metal. An

obstacle having a load cell was positioned at the end of the conveyor chain so as to measure the tensile stress of the bottles pushed against said obstacle. Either bottles made of glass or refillable bottles made of poly (ethylene terephthalate) (REFPET; 1L or 1,5L volume) were transported with the conveyer chain. The lu- bricant solution was either dosed for 50 seconds to the chain and subsequently 50 seconds no lubricant solution was applied to the chain or the lubricant solution was applied for 1 minute to the chain followed by a 5 minute pause of dosage. The fric- tion coefficient is the quotient of the tensile stress measured with the weight of the bottles pushed against the obstacle (table 2, 4th column).

The friction coefficient for the emergency run was measured as follows : The ob- tained lubricant solution was applied for 5 minutes to the running conveyor chain.

Subsequently, for each test run several test bottles characterized in table 2 were positioned on the conveyor chain. The bottles were transported on the conveyor chain and pushed against the obstacle positioned at the end of the conveyor chain. For 35 minutes the lubricant solution was applied to the chain in a 10 sec- ond dosage/10 second pause sequence.

Subsequently, the dosage of the lubricant solution was ceased and after 15 min- utes the tensile stress of the bottles with the obstacle was measured. The friction coefficient for the emergency run is the quotient of the measured tensile stress with the weight of the bottles pushed against the obstacle (table 2, 5th column).

Table 2 chain bottle Dosage friction coef-friction coeffi- material material ficients cient of emer- [1] gency run [1] Metal glass 50 s lubricant solu-0, 35-0,06 0,06 tion/ 50 s pause Metal glass 1 min lubricant solu-0, 05-0,06 0,07-0, 09 tion/ 5 min pause Metal REFPET, 50 s lubricant solu-0, 05-0,06 0,08-0, 1 1 L volume tion/ 50 s pause Metal REFPET, 1 min lubricant solu-0, 06-0,07 0,08-0, 1 1 L volume tion/ 5 min pause Metal REFPET, 50 s lubricant solu-0, 04-0,05 0,07-0, 09 1, 5 L volume tion/ 50 s pause Metal REFPET, 1 min lubricant solu-0, 06-0,07 0,07-0, 1 1,5 L vo-tion/ lume 5 min pause

As can be seen from table 2 the friction coefficients measured do not significantly depend on the material of the bottle. The lubrication of the conveyer chain was sufficient in the entire test run. Furthermore the emergency run, which means that the application of lubricant to the chain was ceased, was successful over a suffi- cient period of time (15 minutes), since the friction coefficient was sufficiently low.

A further test exhibited that the emergency run was successful for a longer period of time such as 1,5 to 2 hours. Furthermore, no bottle fell down onto the chain during the entire test runs.

Since the lubrication solution is applied to the chain in a 50 second lubrication dosage followed by a 50 second pause or, alternatively, in a 1 minute lubrication dosage followed by a 5 minute pause the lubricant solution according to the pres- ent invention offers a superior dosing concept.

Due to said novel dosage concept, the amount of lubricant necessary is decreased significantly which results in a waste water reduction and, thus, in a significant cost reduction. Furthermore, a persistent film build up after drying of the lubricant solu- tion on the surface of the conveyer chain. Said film can easily be reactivated by spraying water onto said film.

The efficiency of the concentrate and lubricant solution according to the present invention was not depending on the hardness of the water used.

3. TNO test The TNO method was performed to determine the material compatibility (TNO Nutrition and Food Research, Code of Practice, "Guidelines for an Industrial Code of Practice for Refillable Polyester Based Bottles", Edition 2,2000).

Three new test bottles made of PET are filled with tap water. The bottom of the bottles is dipped for a short moment (approx. 5 s) in the concentrate of table 1 so that the whole bottom of the bottle is in contact with the concentrate (approx. 5 cm

deep). Excess concentrate is drained off the bottle (approx. 10s). Subsequently, each test bottle is pressurized with carbon dioxide via a connecting tube and the pressure is increased to approx. 7,5 bar for 30 s. The test bottles are stored under a constant pressure of 7,5 0,2 bar for 72 hours at room temperature and after- wards the pressure is decreased in approx. 30 s to zero. The bottles are emptied and rinsed thoroughly, first with tap water and finally with demineralized water. After drying, the bottom of each bottle is examined visually whether deviations (e. g. haziness, whitening, cracks) occurred.

The concentrate of the present invention exhibited a superior test result compara- ble with the best lubricants known in the prior art. The test bottles were not detri- mentally affected by the concentrate of the present invention. No cracks in the test bottles occurred. The test bottles remained clear which means that no haziness occurred during testing. Thus, the concentrate of the present invention is superior compared with the compositions known in the prior art.