DE4315271A1 - Lubricant compositions - Google Patents

Description

The present invention relates generally to polyamine Lubricant compositions. In particular concerns they lubricant compositions and their use in the food and beverage industry for the lubrication of Conveyor belts.

In the food and beverage industry, such as B. in Breweries, bottle cleaning, filling the same and the labeling etc. predominantly automatically carried out. Lubricants are prevalent in these applications all necessary when there is friction between solid upper surfaces occur, such as B. between glass and metal, art fabric (e.g. PET) and metal or metal and metal which need to be reduced. Lubricants are very common in Bottling and bottle conveying systems for Schmie tion of the conveyor and conveyor belts used to a poss best possible trouble-free transportation of the bottles on the Ensure conveyor belt.

Potash lubricating soaps are frequently used as belt lubricants in the above-mentioned systems. B. synthetic non-ionic or ionic surfactants can be added ver used. A major disadvantage of these potash lubricating soaps is their sensitivity to hard water. Such Fen are tend to with the present in hard water Katio such. As calcium ²⁺ to form poorly soluble deposits, which on the one hand reduce the efficiency of the lubrication and on the other hand lead to considerable contamination of the transport device. Since these deposits require frequent, costly and time-consuming cleaning of the system, the water hardness must be masked by complexing agents (usually EDTA) when using alkaline lubricating soaps or soft water must be used.

It is known that instead of potash lubricating soaps syntheti cal lubricants can be used, especially those on Amine base that does not have the disadvantages of potash soaps sen. A large number of such ver bonds described. In this context, the Patents and patent applications DE-A-36 31 953, US-A- 4,839,067, JP-A-74/010794, JP-A-89/096294, US-A-4,521,321, US-A-4,604,720, AU-A-10004/83, EP-A-0 260 508, EP-A-0 384 282 and EP-A-0 260 508. The synthe described there Table lubricants generally have an improvement compared to potash lubricating soaps, but often tend to in addition, difficult to dissolve in polyvalent anions in hard water to form precipitates. This leads to anion sensitivity to so-called cloudiness and especially pollution and clogging of the nozzles through which the lubricants add compositions are dosed onto the conveyor belts. This Precipitates must be removed from the plant regularly, often daily be removed as they block the dosing nozzles can and on the other hand the lubricating and sliding effect of Reduce lubricant. This behavior is most important then very critical if the water used is high Contains polyvalent anions. This is why it often requires the water, which is called dilution is used with ion exchange materials to treat.

In order to improve the above-mentioned disadvantages Patent application EP-A-0 372 628 a lubricant composition tion proposed that the at least one amine compound Formulas (II) or (III)

contains, wherein R¹ is a saturated or unsaturated linea rer or branched alkyl radical having 8 to 22 carbon atoms, R² Hydrogen, an alkyl group or hydroxyalkyl group with 1 up to 4 carbon atoms or A-NH₂, A is a linear or branched Alkylene group with 1 to 8 carbon atoms and A¹ is a linear or branched alkylene group having 2 to 4 carbon atoms. This However, lubricants taught in EP-A-0 372 628 solve the existing disadvantages only partially.

Another disadvantage of those used in the prior art amine-containing lubricant solutions is the drawback certain goods. For example, from EP A-0 372 628 and EP-A-0 384 282 known amine lubricants medium so-called stress corrosion cracking on polyethylene tere phthalate (PET) and polycarbonate (PC) containers.

There is therefore a need to lubricate Trans conveyor belts in the food and beverage industry, ins especially with regard to PET and PC containers.

The object of the invention was to provide a lubricant means for the lubrication of such conveyor belts, in which the disadvantages of the prior art at least partially be avoided. The object of the invention was, in particular Development of a lubricant that is excellent Has a lubricating effect without stubborn, harmful Deposits are formed and stress cracks on PET and PC containers are caused.

This object was achieved by a Lubricant composition, especially for lubricating Conveyor belts in the food and beverage indu strie, which is characterized in that it at least an amine compound of the general formula (I)

R¹- (NH-CH₂-CH₂-CH₂) _x -NH₂ (I),

where x is a positive integer from 2 to 4,
R¹ is a linear or branched alkyl group with 8 to 22 carbon atoms, which can be mono- or polyunsaturated and optionally contains a diluent and / or auxiliaries or additives.

A particular advantage of the lubricants according to the invention compositions is that, in contrast to those in the State-of-the-art lubricants containing amine, especially with high carbonate and non-carbonate hardness (e.g. sulfate hardness) of water in the range of 25 ° dH, a significantly lower tendency to form milky cloudiness and have flocculation. This will keep you going even at high Water hardness and the associated high levels polyvalent anions (e.g. carbonate, sulfate and phosphate) for example, blockages of the spray nozzles for application gene of the tape lubricant solution according to the invention on the Conveyor belt reduced or largely prevented, so that the Be conventionally associated with the precipitates failure to drive.

In addition, it has been found that the inventive Compositions are capable of poorly soluble salts, the lubricants containing amine of the prior art, for example by fatty alkyl monoamines and N-fatty alkyl 1,3- diaminopropanes are formed to disperse. This is it is possible to assemble the lubricant of the invention tongues also for the suppression and removal of amine precipitations to use.

Furthermore, it was completely surprising that the inventor lubricant compositions according to the invention in use few during the transport of PC and PET containers  or no corrosion (stress cracking) on them chen. By reducing the corrosiveness of the Invention according to band lubricant solutions, the lifespan of refillable PC and PET containers increases.

The alkyl radical R¹ in formula (I) contains 8 to 22, preferably 12 to 20, particularly preferably 16 to 20 carbon atoms and can be made of natural or synthetic fats. R1 can e.g. B. Coconut fatty alkyl, tallow fatty alkyl, stearyl, lauryl and others mean natural or synthetic fatty alkyl groups.

Preferably, x in formula (I) is 2 or 3, whereby the formula (I) the meaning of a linear dipropylene tri has amine or a linear tripropylenetetramine, where x 3 is particularly preferred. The amines according to the invention can also be used in a mixture with other suitable amines be set.

Typical suitable for the compositions according to the invention Nete amines are, for example, the commercial products amine 680, Amin 660, Amin 760 from Berol.

The lubricant compositions according to the invention are mostly in aqueous solution and continue to contain as Auxiliary or additive one or more acids, preferably two se physiologically compatible acids, which with amines of Formula (I) does not form poorly soluble precipitates. Especially The preferred examples are acetic acid and glycolic acid. The addition of acid serves to adjust the pH of the Composition which preferably has a pH in the range of Is 4 to 8.

In a preferred embodiment of the invention Lubricant composition is used in an aqueous Solution in addition to at least one amine compound of the general  Formula (I) and the above acid further auxiliary and Additives such as surfactants, preferably non-ionic surfactants de such as, for example, fatty alcohol polyalkylol ethers, and / or Defoamers, such as fatty acid esters.

Particularly preferred lubricants together according to the invention Settlements contained in an aqueous solution, based on the Total formulation 0.001 to 30 wt .-% amine compounds Formula (I), 0.001 to 20 wt% acid, e.g. B. acetic acid or / and glycolic acid, 0 to 5% by weight of surfactants and 0 to 2 % By weight defoamer.

The lubricant compositions of the invention are preferably manufactured and stored as a concentrate, and can then diluted if necessary in an application-oriented manner. Typical concentrates of this type contain 5 to 20%, min at least one amine compound of the general formula (I)

R¹- (NH-CH₂-CH₂-CH₂) _x -NH₂,

where x is a positive integer from 2 to 4, R¹ is a linear or branched alkyl group with 8 to 22 C- Is atoms that can be mono- or polyunsaturated, 3 to 12% acetic acid and / or glycolic acid, 0 to 5% not ionic surfactants, such as fatty alcohol polyalkylol ether, 0 to 2% defoamer, such as fatty acid ester and 61 to 92% water.

The amine is used to produce the lubricant concentrate suspended in water and then consecutively the surfactants, the defoamers and the acid are added and stirred until a clear solution is obtained. The pH of the Concentrate is preferably between 4 and 8.  

The lubricant compositions of the invention are particularly suitable as a belt lubricant in food medium or beverage industry. For this purpose the above-mentioned lubricant concentrates are preferred wise in automatic dosing systems in dilution from 0.1 to 1% via spray nozzles on the conveyor belts applied, the pH preferably between 5 and 8 lies.

The above-mentioned aqueous lubricants according to the invention indicate when used in conventional bottling were, for example, in DE-A-36 31 953 and US-A- 4,839,067 are described as having excellent properties Conveyor chain lubricant.

The invention is further illustrated by the following examples become clear.

Examples

For the production of the band lubricant con Centrates were placed in a mixer with water and the amine suspended in it. Subsequently, surfactants were optionally or / and defoamer added and with the acid a pH Concentrate value set between 4 and 8. The Ge the mixture was stirred until a clear solution was obtained.

example 1

Typical compositions of the invention made by the general process included
5-20% of an amine of formula (I) with x = 2-4
3-12% acetic acid or glycolic acid
0-5% non-ionic surfactants (e.g. fatty alcohol polyalkyl ether)
0-2% defoamer (e.g. fatty acid ester)
61-92% water.

Examples 2 to 4

Following the general procedure above, three aqueous lubricant concentrates according to the present Er produced, which, based on the overall formulation, in each case 10% by weight of an amine of the formula (I) with x = 2, 3 or 4.8% by weight of acetic acid and 82% by weight of water.

The belt lubricant concentrates were then by means of automatic dosing systems in dilutions of 0.1 up to 1.0% by weight via spray nozzles on the conveyor belts applied, the pH of the application solution between 5 and 8 lies.

In all cases, an equally good lubricating effect was observed kung, without having to store the tapes for a long time residues of lubricant or precipitates ten.

The same results were obtained when used for lubrication a lubricant produced according to the above-mentioned process telzentrat was used, the 10 wt .-% of a mixture of amines of formula (I) with x = 2, 3 or / and 4 contained.

Example 5 Production of 1000 kg belt lubricant concentrate

770 l (77%) of demineralized water are pre-mixed sets and with stirring 100 kg (10%) of tallow fat dipropylenetriamine (Amine 660, Berol) added and suspended. Then be 30 kg (3%) of nonionic surfactant (Synperonic LF / RA 30, ICI) and 100 kg (10%) 60% acetic acid under  added constant stirring. It is recommended to continue for approx. 1 hour stir, after which a yellowish clear concentrate is obtained becomes.

The belt lubricant concentrate was automatically working dosing systems in dilutions of 0.1 to 1.0% Spray nozzles applied to the conveyor belts. The pH the application solution is between 5 and 8.

Example 6 (comparative measurements)

In waters with high water hardness and the associated high levels of hydrogen carbonate, sulfate and possibly phosphate leads the use of amines (I) with x <1, preferably x = 2 or 3, to significantly lower precipitates in the form of amine salt compared to application solutions of amines (I) x = 0 or 1.

Application solutions of amines of structure (I) tend to Dependence on the alkyl radical R₁ and the variable x and the anion content (sulfate, hydrogen carbonate) of the used Water more or less strong to cloud down to Flocculation. To examine the tendency to clouding various amine derivatives of structure (I) were in the form their acetates at a concentration of 333 ppm in one standardized water with 250 ppm sulfate (14.6 ° dH) and 250 ppm hydrogen carbonate (11.5 ° dH) dissolved. The occurring Turbidity became photometric depending on the time measured. The following commercially available amines were: examined (Table 1):  

Table 1

Amine types, trade names and manufacturers

The amine acetate solutions with x = 0 spontaneously formed milky cloudy solutions that flocculated after a short time. This Amine solutions were not examined further photometrically.

Of the amine salt solutions listed in Table 2 were Absorbance values measured several times within 72 h (photo Meter PF 10 from Macherey and Nagel, 380 nm, layer thickness 1 cm). Table 2 contains the determined extinction values, where the value 0.020 of a clearly visible turbidity corresponds.

Table 2

Absorbance values of amine acetate solutions as a function of time

Table 2 shows:

• - With constant R₁, the cloudiness decreases with increasing x
• - if x remains the same, the opacity will decrease supply by shortening the alkyl chain R₁
• - In comparison of the isomeric tallow fat dipropylene triamine brings the branching to N₁ a clear Increase in the tendency to cloud.

Example 7 (comparative measurements)

The use of amines (I) with x <1 reduces the corro sensitivity of the belt lubricant solutions to plastics, preferably PET, compared to solutions of the amines (I) with x = 0 or 1.

To investigate the corrosiveness of the tape lubricant solution New refillable 1.5 l PET bottles with 1470 were used ml of deionized water and 20 ml of 75% sulfuric acid filled. To simulate Erfri's carbonic acid pressure 10 g sodium carbonate were added quickly and tightly closed the bottle. The bottoms were then up to approx. 5 cm from the base approx. 10 sec investigating 10% amine acetate solution and then immersed in hanging in a tempered cabinet at 40 ° C for 1 week kept. Then the bottoms were desalted water and the resulting corrosion cracks visually counted. The corresponding standard was demonstrated No corrosion cracks on completion of the test. Table 3 contains the determined corrosion data.  

Table 3

Corrosiveness of 10% fatty amine acetate solutions compared to 1.5 l PET bottles

Table 3 shows:

• - Irrespective of the variable x, short-chain (R₁ = C _12/14 ) amine acetates are highly corrosive to PET
• - With long-chain amine acetates (R₁ = C _16/18 ), the corrosivity decreases with increasing x
• - if the x remains the same, the corrosiveness decreases by extending the alkyl chain R₁

Example 8

The suitability of the amines (1) with x = 2 or 3 as lubricants for bottle transport in the beverage industry an in-house pilot plant under practical conditions gene determined. In continuous operation, regarding off flocculation and corrosion achieved excellent results.

Claims (11)

1. Lubricant composition, especially for lubricating conveyor belts in the food and beverage industry, characterized in that it contains at least one amine compound of the general formula (I) R¹- (NH-CH₂-CH₂-CH₂) _x -NH₂, where x is a positive is an integer from 2 to 4,
R¹ is a linear or branched alkyl group with 8 to 22 carbon atoms, which can be mono- or polyunsaturated and optionally contains a diluent and / or auxiliary agents or additives. 2. Lubricant composition according to claim 1, characterized, that x is 2 or 3. 3. Lubricant composition according to claim 1 or 2, characterized, that it is an aqueous solution. 4. Lubricant composition according to claim 1, 2 or 3, characterized, that it contains an acid as an auxiliary or additive. 5. Lubricant composition according to claim 4, characterized, that it contains acetic acid and / or glycolic acid.   6. Lubricant composition according to claim 4 or 5, characterized, that the acidity is sufficient to maintain a pH from 4 to 8. 7. Lubricant composition according to one of the preceding the claims characterized, that they 0.001 to 30 wt .-% amine compounds of the formula (I) contains. 8. The lubricant composition according to claim 7, characterized, that it contains 0.001 to 20 wt .-% acid. 9. Lubricant composition according to one of the preceding the claims characterized, that they are 0 to 5 as further auxiliaries and additives % By weight of surfactants and / or 0 to 2% by weight of defoamer holds. 10. Use of a lubricant composition according to a of claims 1 to 9 in the food or Ge beverage industry. 11. Use according to claim 10 as a belt lubricant.