EP3375850A1 - High-temperature lubricant for the food industry - Google Patents

Abstract

The invention relates to a food-grade high-temperature lubricant, in particular a high-temperature oil and a high-temperature fat comprising the following components:
a) at least one oil selected from a trimellitic acid ester or a mixture of different trimellitic esters, alkylaromatics, preferably an aliphatically substituted naphthalene or estolides;
b) a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene and;
c) additives individually or in combination.

In the case of high-temperature fat, a thickening agent is added.

Description

The invention relates to a high-temperature lubricant, in particular a high-temperature oil based on an aromatic ester, such as a trimellitic acid ester and mixtures of various trimellitic acid esters, heteroaromatics, estolides and a fully hydrogenated or hydrogenated polyisobutylene or a mixture thereof. Furthermore, the high-temperature lubricant may be a high-temperature grease when a thickening agent is added to the above-mentioned components. The invention further relates to the use of these high temperature lubricants for lubricating implements used in the processing of food.

In addition to the lubricating effect, the lubricants must fulfill a variety of other tasks: they must cool, reduce friction, wear and power transmission, protect against corrosion and at the same time have a sealing effect.

Conventional lubricants are not suitable for high temperature applications because they are destroyed at high temperatures, for example by oxidation and / or thermal decomposition reactions and polymerizations and their lubricating properties are severely limited. In decomposition reactions, the lubricant becomes volatile in low molecular weight Components split. Their evaporation leads to undesirable viscosity changes, oil loss and excessive vapor formation. This results in a loss of lubricity. Also by polymerization, the lubricants lose their lubricating effect due to the formation of insoluble polymerization products.

The removal of these contaminants increases the maintenance work and produces chemical waste, which must be disposed of consuming. Due to the increased cleaning and maintenance work, the downtime increases. Overall, the use of unsuitable lubricants in high-temperature applications leads to higher costs, as the tools pollute and there is a greater need for lubricants. In addition, the product quality decreases.

Synthetic esters are often used as base oils for high-temperature applications since they have very good oxidative, hydrolytic and thermal stability.

In order to meet the diverse requirements of high-temperature applications, the lubricants must have, among other things, high stability, low friction coefficients and high wear resistance. In order to ensure uniform lubrication even at high temperatures, a liquid lubricant film must remain between metal parts during the entire processing process. Therefore, the lubricant must evaporate only slightly at the maximum processing temperature, form little residue and form as few cracking residues as possible.

High processing temperatures often occur during food processing, such as cooking, baking, boiling, roasting, braising, sterilizing, frying and steaming. In these processes, various tools are used. To lubricate these tools high temperature resistant lubricants are necessary.

To the base oils for lubricating equipment for the processing of Foods are subject to special environmental and toxicity requirements. In principle, a food-grade lubricant H1 should be suitable if the lubricant can come into direct or indirect contact with foodstuffs, food and groceries. Preferred applications in the food industry include chains in ovens and other high temperature applications, as well as conveyor hangers, especially trolleys and their bearings.

These lubricants are subject to regulatory requirements such as NSF / H1 or NSF / H2 certification.

The classification "H1" is to be obtained from lubricants that are in "incidental food contact", that is to say in an occasional technically unavoidable contact with foodstuffs. However, intentional or permanent contact should also be excluded when using "H1" lubricants. An "H2" classification can produce lubricants that are non-toxic and non-carcinogenic. When using "H2" lubricants, however, any contact with the food must be excluded.

A disadvantage of the known food-grade lubricants that are used in the high temperature range, is that they often have an unsatisfactory, technical performance. Although the food-compatible lubricants used hitherto have a good oxidation resistance and an acceptable pour point, their residue behavior after complete evaporation does not correspond to the high demands demanded in high-temperature applications. The resulting cracking residues form deposits, which must be removed again after some time. As a rule, the operation of the plant must be stopped and the residue removed or the components replaced. There is therefore a need for a high-temperature lubricant in which the evaporation of individual base oil components of the oil are greatly reduced and at constant higher temperature over a long period of time, the lubricating effect is not lost.

The object of the present invention is to provide a high-temperature oil and a high-temperature grease, which meets the standards of NSF / H1 lubricant and moreover has satisfactory tribological properties. In particular, the lubricant should show a good lubricating effect at high temperature over a long period of time. Furthermore, the Vercrackungsrückstände should not be laked, but be redissolvable by fresh oil. Furthermore, the high-temperature lubricant should have a good hydrolytic stability, be resistant to corrosion and wear, and have a good oxidation resistance and adapted to the requirements of low-temperature behavior.

1. a) 93,9 bis 45 Gew.-% mindestens eines Öls, ausgewählt aus der Gruppe bestehend aus einem Gemisch aus Trimellitsäure-tri(iso-C₁₀)ester (1) und Trimellithsäure-tri(iso-C₁₃)ester (2), wobei das Mischungsverhältnis von (1) zu (2) bei 99:1 bis 1:99, Alkylaromaten, vorzugsweise aliphatisch substituiertes Naphthalin, Estoliden;
2. b) 6 bis 45 Gew.-% eines Polymers, nämlich eines hydrierten oder vollhydrierten Polyisobutylen oder einer Mischung aus hydrierten oder vollhydrierten Polyisobutylen;
3. c) 0,1 bis 5 Gew.-% Additive einzeln oder in Kombination, ausgewählt aus der Gruppe bestehend aus Korrosionsschutzadditiven, Antioxidanten, Verschleißschutzadditiven, UV-Stabilisatoren, anorganischen oder organischen Feststoffschmierstoffen.

This object is achieved by a food-compatible high-temperature oil comprising the following components:

1. a) 93.9 to 45 wt .-% of at least one oil selected from the group consisting of a mixture of trimellitic acid tri (iso-C ₁₀ ) ester (1) and trimellitic tri (iso-C ₁₃ ) ester (2 ), wherein the mixing ratio of (1) to (2) at 99: 1 to 1:99, alkylaromatics, preferably aliphatically substituted naphthalene, estolides;
2. b) 6 to 45 wt .-% of a polymer, namely a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene;
3. c) 0.1 to 5 wt .-% of additives individually or in combination, selected from the group consisting of corrosion protection additives, antioxidants, anti-wear additives, UV stabilizers, inorganic or organic solid lubricants.

1. a) 91,9 bis 30 Gew.-% mindestens eines Öls, ausgewählt aus der Gruppe bestehend aus einem Gemisch aus Trimellitsäure-tri(iso-C₁₀)ester (1) und Trimellithsäure-tri(iso-C₁₃)ester (2), wobei das Mischungsverhältnis von (1) zu (2) bei 99:1 bis 1:99, Alkylaromaten, vorzugsweise aliphatisch substituiertes Naphthalin, Estoliden;
2. b) 6 bis 45 Gew.% eines Polymers, nämlich eines hydrierten oder vollhydrierten Polyisobutylen oder einer Mischung aus hydrierten oder vollhydrierten Polyisobutylen;
3. c) 0,1 bis 5 Gew.-% Additive einzeln oder in Kombination, ausgewählt aus der Gruppe bestehend aus Korrosionsschutzadditiven, Antioxidanten, Verschleißschutzadditiven, UV-Stabilisatoren, anorganischen oder organischen Feststoffschmierstoffen und
4. d) 2 bis 20 Gew.-% Verdickungsmittel.

The food-grade high-temperature fat according to the invention comprises:

1. a) 91.9 to 30 wt .-% of at least one oil selected from the group consisting of a mixture of trimellitic acid tri (iso-C ₁₀ ) ester (1) and trimellitic acid tri (iso-C ₁₃ ) ester (2 ), wherein the mixing ratio of (1) to (2) at 99: 1 to 1:99, alkylaromatics, preferably aliphatically substituted naphthalene, estolides;
2. b) 6 to 45% by weight of a polymer, namely a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene;
3. c) 0.1 to 5 wt .-% of additives individually or in combination, selected from the group consisting of anti-corrosion additives, antioxidants, anti-wear additives, UV stabilizers, inorganic or organic solid lubricants and
4. d) 2 to 20 wt .-% thickener.

Surprisingly, it has been found that the high-temperature oil according to the invention and the high-temperature fat according to the invention are both suitable for an H1 classification and are distinguished by outstanding performance. Thus, the high-temperature oil or high-temperature grease according to the invention exhibits high thermal stability combined with a long service life and good lubricating properties.

The high-temperature oil and the high-temperature fat of the present invention comprise as an ester compound a trimellitic acid ester or a mixture of various trimellitic acid esters, wherein the alcoholic group of the ester is a linear or branched alkyl group having 8 to 16 carbon atoms. Depending on the choice of the aromatic ester, the properties of the lubricant, for example the viscosity, the viscosity-temperature behavior, the oxidation resistance and residue behavior can be adjusted.

According to a particularly preferred embodiment of the invention, the aromatic ester comprises a sterically hindered alcohol as alcohol component, preferably an alcohol having 8 to 16 carbon atoms, in particular 10 to 13 carbon atoms, in particular trimellitic tri (iso-C ₁₀ ) ester (1) and trimellitic acid tri (iso-C ₁₃ ) ester (2). The mixing ratio of (1) to (2) is 99: 1 to 1:99, more preferably, the mixing ratio of (1): (2) is 87.12.

The high-temperature oil according to the invention or the high-temperature fat according to the invention may contain a second oil which comprises an aromatic.

According to the invention, an aromatic means a monocyclic, bicyclic or tricyclic ring system having four to fifteen carbon atoms, the monocyclic ring system being aromatic or at least one of the rings being aromatic in a bi- or tricylic ring system. Preference is given to using a bicyclic ring system which preferably has 10 carbon atoms.

Preferably, the aromatic is substituted with one or more aliphatic substituents. The aromatic is particularly preferably substituted by one to four aliphatic substituents and in particular by two or three aliphatic substituents.

An alkyl group according to the invention is a saturated aliphatic hydrocarbon group having 1 to 30, preferably 3 to 20, more preferably 4 to 17 and especially 6 to 15 carbon atoms. An alkyl group may be linear or branched and is optionally substituted with one or more of the abovementioned substituents.

Practical experiments have shown that mixtures of differently substituted naphthalenes, ie mixtures of naphthalenes, which have a different degree of substitution and different aliphatic substituents, are particularly suitable. In this case, by varying the mixture composition, the properties, such as the viscosity, of the high-temperature lubricant can be set particularly easily. Aliphatic-substituted naphthalenes are also characterized by excellent dissolution properties and high thermo-oxidative stability.

The viscosity, measured at 40 ° C, of the aliphatically substituted naphthalene is preferably 30 to 600 mm ² / s, more preferably 30 to 300 m ² / s.

Furthermore, estolides can also be used as component a). Preferred viscosities, measured at 40 ° C are between 30 and 500 mm ² / sec. Viscosities of 30 to 140 mm ² / sec are particularly preferred.

Estolides are ester compounds which are acid or enzymatically catalyzed from fatty acids, preferably oleic acid or dicarboxylic acids. The acid function attacks the double bond of an adjacent fatty acid molecule, resulting in a higher molecular weight ester compound. The terminal acid group is then usually esterified with an alcohol, preferably 2-ethyl-hexanol, and then the remaining double bonds are hydrogenated or with carboxylic acid, e.g. Acetic acid esterified. Other alcohols such as e.g. Isoamyl alcohol or Guebert alcohols are also conceivable for the esterification of the terminal acid group.

Other estolides can also be synthesized via a condensation of hydroxycarboxylic acids, for example oleic or stearic acid derivatives. The chain length of the hydroxycarboxylic acids or unsaturated acids used can range from C ₆ to C ₅₄ . The acids may contain other functional groups such as amines, ethers, sulfur-containing groups. In addition, an esterification with alpha-olefins or ß-Farnesen is conceivable.

The high-temperature oil or high-temperature grease according to the invention furthermore comprises a polyisobutylene. By suitable choice of the polyisobutylene, in particular with regard to the degree of hydrogenation and molecular weight, the properties of the oil and fat according to the invention, for example their kinematic viscosity, can be influenced in a desired manner. The polyisobutylene can be used in hydrogenated or fully hydrogenated form, as well as a mixture of hydrogenated and fully hydrogenated polyisobutylene can be used. Fully hydrogenated polyisobutylenes are preferably used. The polyisobutylene is present in an amount of 6 to 45 wt .-% in the composition, preferably 10 to 45 wt .-%, in particular 15 to 45 wt .-% are used.

According to a further preferred embodiment, the polyisobutylene has a number average molecular weight of 115 to 10,000 g / mol, preferably from 160 to 5000 g / mol.

The high-temperature oil or high-temperature grease according to the invention comprise further from 0.1 to 5 wt .-%, additives which are used individually or in combination and are selected from the group consisting of anti-corrosion additives, antioxidants, anti-wear additives, UV stabilizers, inorganic or organic solid lubricants.

The high-temperature fat according to the invention further comprises a thickener. The thickener in the high-temperature grease of the lubricant composition according to the invention is either a reaction product of a diisocyanate, preferably 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane, 2,4'-diisocyanatophenylmethane, 4,4'-diisocyanatodi phenyl, 4,4'-diisocyanato-3,3'-dimethylphenyl, 4,4'-diisocyanato-3,3'-dimethylphenylmethane, which may be used singly or in combination with an amine of the general formula R ' ₂ -NR , or a diamine of the general formula R ' ₂ -NR-NR' ₂ , wherein R is an aryl, alkyl or alkylene radical having 2 to 22 carbon atoms and R 'identically or differently a hydrogen, an alkyl, alkylene or aryl radical is, or with mixtures of amines and diamines
or
is selected from among Al complex soaps, metal soaps of the first and second main group elements of the perriodic system, metal complex soaps of elements of the first and second main group of the periodic table, bentonites, sulfonates, silicates, aerosil, polyimides or PTFE or a mixture of the foregoing thickener.

In order to comply with the legal requirements regarding the use of lubricants for lubricating equipment for processing food, it is useful if the additives used have an H1 classification.

The addition of antioxidants can reduce or even prevent the oxidation of the oil or fat according to the invention, in particular when it is used. Oxidation can lead to undesirable free radicals and, as a result, decomposition reactions of the high-temperature lubricant can occur. The addition of antioxidants turns the high-temperature oil or grease stabilized.

Particularly suitable antioxidants according to the invention are the following food-compatible compounds:
diaromatic amines, phenolic resins, thiophenol resins, phosphites, butylated hydroxytoluene, butylated hydroxyanisole, phenyl-alpha-naphthylamine, phenyl-betanaphthylamine, octylated / butylated diphenylamine, di-alpha-tocopherol, di-tert-butyl-phenyl, benzenepropanoic acid and mixtures of these components.

• IRGANOX® 1010 (Benzolpropansäure, 3,5-bis(1, 1-Dimethylethyl)-4-hydroxy-2,2-bis[[3-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propandiylester; IRGANOX® L06 (alkyliertes Phenyl-alpha-naphthylamin oder N-Phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthalenamin;
• IRGANOX® L01 (dioctyliertes Diphenylamin);
• IRGANOX® L57 (Mischung aus alkylierten Diphenylaminen);
• IRGANOX® L06;
• IRGANOX® L 115;
• IRGANOX® L150 (Mischung aus aminischen und phenolischen Antioxidantien mit hohem Molekulargewicht);
• IRGANOX® L64 (Mischung aus Mono- und Dialkyl- butyl/octyl -diphenylamin);
• IRGANOX® 1035; (Mischung bestehend aus Thiodiethylenbis(3,5-di-tert-butyl-4-hydroxyhydrocinnamat);
• IRGANOX® 1010;
• IRGANOX® L101 (Mischung bestehend aus Tetrakis[methylen-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionat]methan);
• IRGANOX® L109 (Benzolpropansäure, 3,5-bis(1,1-dimethyl)-4-hydroxy-1,6-Hexandiylester);
• IRGANOX® L57;
• IRGANOX® L109;
• Irgalube® TPPT;
• IRGANOX® L115 (Benzolpropansäure, 3,5-Bis(1,1-dimethylethyl)-4-hydroxy-, thiodi-2, 1- Ethandiylester);
• IRGANOX® E201 (flüssiges DL-alpha-tocopherol, 2H-1-Benzopyran-6-ol,3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-Trimethyltridecyl);
• IRGAFOS® 168 (Mischung enthaltend Tris(2,4-di-tert-butylphenyl)Phosphat); ADDITIN® RC7130 (N-Phenyl-1-naphthylamin);
• Na-LUBE® A0142 (flüssiges Diphenylamin basiertes Antioxidant);
• VANLUBE® 961 (Mischung aus octyliertem und butyliertem Diphenylamin oder Benzolamin, N-Phenyl, Reaktionsprodukt aus 2,4-Trimethylpentan und 2-Methylpropen);
• VANLUBE® PCX (Mischung enthaltend 1-Hydroxy-4-methyl-2-6-di-tert-Butylbenzol); Hexamethylenbis(3,5-di-tert-butyl-4-Hydroxyhydrocinnamt);
• Irgafox® 168; Reaktionsprodukt aus N-Phenylbenzolamin mit 2,4,4-Trimethylpenten; Thiodiethylenbis(3,5-di-tert-butyl-4-hydroxyhydro-Cinnamatmethan); Bis(4-(1,1,3,3-tetramethylbutyl)phenyl)amin;
• 3,5-Bis(1,1-dimethylethyl)-4-hydroxyester;
• Thiodi-2,1-Ethandiylester.

Commercially available food-grade additives are:

• IRGANOX® 1010 (benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy-2,2-bis [[3- [3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] 1-oxopropoxy] methyl] -1,3-propanediyl ester; IRGANOX® L06 (alkylated phenyl-alpha-naphthylamine or N-phenyl-ar (1,1,3,3-tetramethylbutyl) -1-naphthalenamine;
• IRGANOX® L01 (dioctylated diphenylamine);
• IRGANOX® L57 (mixture of alkylated diphenylamines);
• IRGANOX® L06;
• IRGANOX® L 115;
• IRGANOX® L150 (mixture of high molecular weight amine and phenolic antioxidants);
• IRGANOX® L64 (mixture of mono- and dialkylbutyl / octyldiphenylamine);
• IRGANOX® 1035; (Mixture of thiodiethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate);
• IRGANOX® 1010;
• IRGANOX® L101 (mixture consisting of tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane);
• IRGANOX® L109 (benzenepropanoic acid, 3,5-bis (1,1-dimethyl) -4-hydroxy-1,6-hexanediyl ester);
• IRGANOX® L57;
• IRGANOX® L109;
• Irgalube® TPPT;
• IRGANOX® L115 (benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy, thiodi-2, 1-ethanediyl ester);
• IRGANOX® E201 (liquid DL-alpha-tocopherol, 2H-1-benzopyran-6-ol, 3,4-dihydro-2,5,7,8-tetramethyl-2- (4,8,12-trimethyltridecyl);
• IRGAFOS® 168 (mixture containing tris (2,4-di-tert-butylphenyl) phosphate); ADDITIN® RC7130 (N-phenyl-1-naphthylamine);
• Na-LUBE® A0142 (liquid diphenylamine based antioxidant);
• VANLUBE® 961 (mixture of octylated and butylated diphenylamine or benzene amine, N-phenyl, reaction product of 2,4-trimethylpentane and 2-methylpropene);
• VANLUBE® PCX (mixture containing 1-hydroxy-4-methyl-2-6-di-tert-butylbenzene); Hexamethylene bis (3,5-di-tert-butyl-4-Hydroxyhydrocinnamt);
• Irgafox® 168; Reaction product of N-phenylbenzolamine with 2,4,4-trimethylpentene; Thiodiethylene bis (3,5-di-tert-butyl-4-hydroxyhydro-Cinnamatmethan); amine (4- (1,1,3,3-tetramethylbutyl) phenyl) up;
• 3,5-Bis (1,1-dimethylethyl) -4-hydroxy ester;
• Thiodi-2,1-ethanediyl.

Furthermore, the high temperature oil or grease may contain corrosion inhibiting additives, metal deactivators or ion complexing agents. These include triazoles, imidazolines, N-methylglycine (sarcosine), benzotriazole derivatives, N, N-bis (2-ethylhexyl) -ar-methyl-1H-benzotriazole-1-methanamine; N-methyl-N (1-oxo-9-octadecenyl) glycine, mixture of phosphoric acid and mono- and Diisooctylester reacted with (C _11-14 ) alkylamines, mixture of phosphoric acid and mono- and Diisooctylester reacted with tert-alkylamine and primary (C _12-14 ) amines, dodecanoic acid, triphenyl phosphorothionate and amine phosphates. Commercially available additives are as follows: IRGAMET® 39, IRGACOR® DSS G, amine O; SARKOSYL® O (Ciba), COBRATEC® 122, CUVAN® 303, VANLUBE® 9123, CI-426, CI-426EP, CI-429 and CI-498.

Further conceivable anti-wear additives are amines, amine phosphates, phosphates, thiophosphates, phosphorothionates and mixtures of these components. Commercially available anti-wear additives include IRGALUBE® TPPT, IRGALUBE® 232, IRGALUBE® 349, IRGALUBE® 211 and ADDITIN® RC3760 Liq 3960, FIRC-SHUN® FG 1505 and FG 1506, NA-LUBE® KR-015FG, LUBEBOND®, FLUORO ® FG, SYNALOX® 40-D, ACHESON® FGA 1820 and ACHESON® FGA 1810.

In addition, the oil or the fat may contain food grade solid lubricants such as PTFE, BN, Na pyrophosphate, Zn oxide, Mg oxide, Zn pyrophosphate, Na thiosulfate, Mg carbonate, Ca carbonate, Ca stearate, Zn oxide. Sulfide or a mixture thereof.

Practical experiments have shown that the high-temperature oil or fat according to the invention up to a temperature of 250 ° C has no or negligible decomposition phenomena. By this is meant that less than 10% of the lubricant decomposes.

The high-temperature oil or fat according to the invention may contain, as another food-compatible base oil, an oil, preferably selected from the group consisting of mineral oil, aliphatic carboxylic acid and dicarboxylic acid esters, fatty acid triglycerides and / or poly-alpha-olefins.

In a particular embodiment, the high temperature oil or fat according to the invention contains an estolide, preferably the main constituents of the estolide being obtained by chemical or enzymatic processes starting from native oils from the group of sunflower oil, rapeseed oil, castor oil, linseed oil, corn oil, diest oil, soybean oil, linseed oil , Peanut oil, "Lesqueralle" oil, palm oil, olive oil or mixtures of the aforementioned oils.

Practical tests have shown that the high-temperature oil or fat according to the invention, due to its physical and chemical properties, can be used excellently for lubricating working devices for processing foodstuffs. Due to its good temperature resistance, it can also be used at high use temperatures up to 260 ° C, preferably at temperatures of 150 to 250 ° C, e.g. Chains in ovens.

The invention further relates to a process for the preparation of the above-described high-temperature oil or grease, in which the base oils and the additives are mixed together.

The invention will now be explained in more detail with reference to the following examples.

Examples 1 to 7 Production of a high-temperature oil according to the invention for the food industry

Two trimellitic acid esters are placed in a stirred tank. At 100 ° C, the polyisobutylene and optionally a further oil is added with stirring. Subsequently, the mixture is stirred for 1 h to obtain a homogeneous mixture. The anti-wear agents and the antioxidant are added to the kettle at 60 ° C with stirring. After about 1 hour, the finished oil can be filled into the containers provided.

Composition of high-temperature oils:

Table 1 shows the compositions of the high temperature oils and the redissolvability of the oil residue after complete evaporation of the oil, depending on the added amount of polyisobutylene. <u> Table 1 </ u> Ex.1 Ex. 2 Example 3 Example 4 Example 5 Example 6 Example 7 Fully hydrogenated polyisobutylene 24.41 22.0 19,53 17.1 14.63 12.2 9.76 C ₁₀ - branched trimellitic acid ester (1) 71.52 73.91 76.35 78.76 81.2 83.61 86.02 C ₁₃ branched trimellitic acid esters (2) 0.72 0.74 0.77 0.79 0.82 0.84 0.87 Viscosity 40 ° C mm ² / s 426.8 375.5 328.7 292.7 259 228.8 202.8 Solubility of the residue after 72h / 250 ° C. 4 3 3 2 1 (paint) 1 (paint) 1 (paint) 4 = residue after complete evaporation very good dissolvable
3 = residue readily dissolvable after complete evaporation
2 = residue partially soluble after complete evaporation
1 = residue can not be dissolved after complete evaporation

All figures are in% by weight. The remainder to 100% by weight results from the addition of additives, in particular aminic and / or phenolic antioxidants, corrosion protection additives, wear protection additives EP / AW and metal deactivators.

These results show that, up to a kinematic viscosity at 40 ° C. of 292.7 mm ² / s, it is possible to re-dissolve the residues that have formed after complete evaporation with fresh oil. The composition according to Example 1 shows the best properties in terms of viscosity and re-solubility.

The following Examples 8 to 10 show, in comparison with Comparative Examples 1 to 3, the excellent properties of the food grade high temperature oil of the present invention in view of solubility when different components a) are used as the oil.

Examples 8 to 10 Composition of the oils (all data are in% by weight)

Table 2 Example 8 Comparative Example 1 Trimellitate 1 70.0 52,65 Trimellitate 2 0.7 44.0 hydrogenated PIB 25.95 0.0 Amine Antioxidant 0.5 0.5 phenolic antioxidant 1.5 1.5 Wear protection EP / WA 1.0 1.0 Corrosion protection 0.25 0.25 Metal deactivator 0.1 0.1 solvent resistance very good (4) bad (1) Table 3 Example 9 Comparative Example 2 Trimellitate 1 0.0 52,65 Trimellitate 2 0.0 44.0 alkylated naphthalene 70.65 0.0 hydrogenated PIB 26.0 0.0 Amine Antioxidant 0.5 0.5 phenolic antioxidant 1.5 1.5 Wear protection EP / WA 1.0 1.0 Corrosion protection 0.25 0.25 Metal deactivator 0.1 0.1 solvent resistance very good (4) bad (1) Table 4 Example 10 Comparative Example 3 Trimellitate 1 0.0 52,65 Trimellitate 2 0.0 44.0 Estolid 1 40.4 0.0 Estolid 2 23.25 0.0 hydrogenated PIB 33,00 0.0 Amine Antioxidant 0.5 0.5 phenolic antioxidant 1.5 1.5 Wear protection EP / WA 1.0 1.0 Corrosion protection 0.25 0.25 Metal deactivator 0.1 0.1 solvent resistance very good (4) bad (1)

Table 5 below describes the food-compatible high-temperature fats according to the invention by way of example. <u> Table 5 </ u> Bsp.11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Trimellitate 1 46.3 0.0 46.3 39.0 46.3 46.3 Trimellitate 2 17.1 0.0 17.1 20.0 17.7 17.7 Estolid 1 0.0 38.4 0.0 0.0 0.0 0.0 Estolid 2 0.0 25.6 0.0 0.0 0.0 0.0 alkylated naphthalene 0.0 0.0 0.0 0.0 0.0 0.0 fully hydrogenated PIB 25.0 25.0 25.0 25.0 25.0 25.0 Antioxidant 1.0 1.0 1.0 1.0 1.0 1.0 thickener 10.6 10.0 10.6 15.0 10.0 10.0

To determine the re-solubility, the samples were annealed at 250 ° C for 72 hours. The residue was redissolved with the respective base oil of the fat pattern. In all examples the re-solubility was good.

The thickeners used in Examples 11 to 16 are Li complex (Ex 11 and 12), Al complex (Ex 13), bentonite (Ex 14), Ca single (Ex 15), Li-Simple (Ex. 16) and Urea (Ex.17). <u> Continued Table 5 </ u> Bsp.17 Trimellitate 1 46.3 Trimellitate 2 18.7 Estolid 1 0.0 Estolid 2 0.0 alkylated naphthalene 0.0 fully hydrogenated PIB 25.0 Antioxidant 1.0 thickener 9.0

Furthermore, the remissibility of the oil residue after complete evaporation at two different temperatures (220 ° C / 120h) and (250 ° C / 72h) depending on the mixing ratio of the two trimellitic acid esters (1) and (2) was examined. The concentration of fully hydrogenated PIB was kept constant at 25% by weight. It was surprisingly found that for both temperatures the re-solubility depends on the mixing ratio of the two trimellitic acid esters. At a mixing ratio of 0.02, ie a high proportion of the iso-C ₁₃ trimellitic ester compared to the iso-C ₁₀ ester, the residue can not be redissolved with fresh oil, but the solubility increases with increasing content of iso-C ₁₀ - Trimellithsäureester clearly like the illustration 1 can be seen. At a mixing ratio of 1: 1, a saturation point is reached. The values are also shown in Table 6. <u> Table 6 </ u> Ratio iso-C10 / iso-C13 Solubility of the residue after complete evaporation (aging) 250 ° C / 72h 220 ° C / 120h 0.02 1 1 0.33 2 3 1.00 3 4 2.97 3 4 87.12 3 4 4 = residue after complete evaporation very good dissolvable
3 = residue readily dissolvable after complete evaporation
2 = residue partially soluble after complete evaporation
1 = residue can not be dissolved after complete evaporation

It could therefore be shown that the solubility of the residues not only depends on the degree of hydrogenation of the polyisobutylene, but also on the mixing ratio of the two esters. Both esters must be used in combination to ensure the H1 capability of the high temperature oil. The mixing ratios are freely selectable, starting from a 1: 1 mixture begin the preferred areas. Particularly preferred is the ratio of 87.12 (iso-C ₁₀ / iso-C ₁₃ ).

The above-described food grade high temperature oils and high temperature greases can also be used to lubricate implements that are subject to similar lubricant requirements. These include the cosmetics and pharmaceutical industries as well as the animal feed industry.

With regard to the food industry, the high-temperature lubricants according to the invention can be used for lubricating implements in food processing, as hydraulic oils for the food industry, for transport and timing chains in the food industry, and for devices for the processing of cereals, flour and animal feed and for ovens.

In some applications, use in the form of a spray is advantageous.

Claims (7)

Food-compatible high-temperature oil comprising the following components: a) 93.9 to 45 wt .-% of at least one oil selected from the group consisting of a mixture of trimellitic acid tri (iso-C ₁₀ ) ester (1) and trimellitic tri (iso-C ₁₃ ) ester (2 ), wherein the mixing ratio of (1) to (2) is 99: 1 to 1:99, alkylaromatics, estolides; b) from 6 to 45% by weight of a polymer selected from the group consisting of a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene; c) 0.1 to 5 wt .-% of additives individually or in combination, selected from the group consisting of corrosion protection additives, antioxidants, anti-wear additives, UV stabilizers, inorganic or organic solid lubricants. Food-grade high-temperature fat comprising the following components: a) 91.9 to 30 wt .-% of at least one oil selected from the group consisting of a mixture of trimellitic acid tri (iso-C ₁₀ ) ester (1) and trimellitic acid tri (iso-C ₁₃ ) ester (2 ), wherein the mixing ratio of (1) to (2) is 99: 1 to 1:99, alkylaromatics, estolides; b) from 6 to 45% by weight of a polymer selected from the group consisting of a hydrogenated fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene; c) 0.1 to 5 wt .-% of additives individually or in combination, selected from the group consisting of anti-corrosion additives, antioxidants, anti-wear additives, UV stabilizers, inorganic or organic solid lubricants and d) 2 to 20 wt .-% thickener. High-temperature oil or high-temperature grease according to claim 1 or 2, wherein the alkylaromatic compound is an aliphatic-substituted naphthalene. High-temperature oil or high-temperature fat according to claim 1 or 2, wherein the component comprises a) as a further food-compatible oil, a compound selected from the group consisting of mineral oil, aliphatic carboxylic acid and dicarboxylic acid esters, fatty acid triglycerides and poly-alpha-olefins A high temperature grease according to claim 2, wherein component d) is selected from the group consisting of urea, Al complex soaps, metal soaps of the elements of the first and second main groups of the perriodic system, metal complex soaps of the elements of the first and second main group of the periodic table, Bentonites, sulfonates, silicates, aerosil, polyimides, PTFE or a mixture of the aforementioned thickeners. Use of the high-temperature oil or high-temperature grease according to one of the preceding claims for lubricating work tools in food processing, as hydraulic oil in the food industry, for transport and timing chains, for devices for processing grain, flour and animal feed, and in ovens. Use of the high-temperature oil according to one of the preceding claims as oil in the form of a spray.

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