US20140200169A1

US20140200169A1 - High Temperature Oil

Info

Publication number: US20140200169A1
Application number: US14/119,015
Authority: US
Inventors: Thomas Kilthau; Karl Egersdorfer; Martin Schmidt-Amelunxen
Original assignee: Klueber Lubrication Muenchen SE and Co KG
Current assignee: Klueber Lubrication Muenchen GmbH and Co KG
Priority date: 2011-05-26
Filing date: 2012-05-22
Publication date: 2014-07-17
Also published as: WO2012159738A1; KR101539218B1; AU2012261221A1; SI2714872T1; BR112013030286B1; DE102011102540B4; AU2012261221B2; KR20140009499A; JP2014515412A; EA201301331A1; CN103764808A; ES2601401T3; EP2714872A1; EA026445B1; EP2714872B1; DE102011102540A1; BR112013030286A2; MY164068A; PL2714872T3; CL2013003397A1

Abstract

The invention relates to novel high temperature oils based on aromatic esters, such as trimellitic acid esters, pryomellitic acid esters, trimesic acid esters or a mixture thereof or derivatives of phloroglucinol and a fully hydrated or a hydrated polyisobutylene or a mixture thereof.

Description

The invention relates to novel high-temperature oils based on aromatic esters such as trimellitic esters, pyromellitic esters, trimesic esters or a mixture, or derivatives of phloroglucinol such as phloroglucinol trioctanoate, phloroglucinol tridecanoate and phloroglucinol tridodecanoate thereof, and a fully hydrogenated or a hydrogenated polyisobutylene or a mixture thereof.
High-temperature oils which are used in the field of industrial chain lubrication, for example in conveying systems, painting lines, the textile industry, the insulating materials industry, the glass industry, etc., and belt lubrication in continuous wood pressing plants, typically consist of a three-component system.
This three-component system generally consists of an aromatic ester, a synthetic hydrocarbon and a polymer based on polyisobutylene. The synthetic hydrocarbon is used as a solubilizer. Also added to this lubricant system are commercial additives. However, a disadvantage of these systems is that the use of the synthetic hydrocarbon limits the working temperature of the oil, since it vaporizes very rapidly at temperatures >200° C.
A three-component system is described, for example, in EP 1 154 011 B1. Here, a lubricant oil composition comprising an aromatic ester compound and, as a further base oil, an α-olefin oligomer, and also a polyisobutene, is provided.
As already stated above, the loss of performance for a three-component lubricant composition is high as a result of the vaporization of the solubilizer. The vaporization results in formation of a deposit or a residue formed from the remaining constituents of the lubricant on the application surface or the application area, as a result of which full lubrication can no longer be ensured. This deposit then has to be dissolved again. In general, operation has to be stopped and the residue has to be removed. There is thus a need for a high-temperature oil in which the vaporization of individual constituents of the oil is greatly reduced and hence the lubricity is not lost at constantly high temperature over a long period.
Such a high-temperature oil is especially required for chain and belt lubrication of wood presses, as present, for example, in Contipressen™ continuous presses for the production of laminate floors.
It was an object of the present invention to provide a high-temperature oil with which good lubricity is achieved at constantly high temperature over a long period and which can be provided in different viscosities according to the application.
This object is surprisingly achieved by the provision of a high-temperature oil which consists, as a two-component system an aromatic ester of the general formula (I)
where R1 is a linear or branched alkyl group having 6 to 16 carbon atoms and n is 3 or 4, or a compound of the general formula (II)
where R is a linear or branched alkyl group having a chain length of 8 to 16 carbon atoms and n is equal to 3,
and
a hydrogenated polyisobutylene, a fully hydrogenated polyisobutylene or a mixture of a fully hydrogenated and a hydrogenated polyisobutylene. Preferably, a fully hydrogenated polyisobutylene is included.
In general, the high-temperature oil comprises 40 to 91.9% by weight of the aromatic ester of the general formula (I) or of the compound of the general formula (II) and 50 to 5% by weight of the hydrogenated, fully hydrogenated polyisobutylene or of a mixture of hydrogenated and fully hydrogenated polyisobutylene.
In addition, the high-temperature oil may comprise 0.1 to 6% by weight, especially 2 to 5% by weight, of an antioxidant.
The high-temperature oil may also comprise 0 to 4% by weight, especially 0.3 to 3.5% by weight, of an antiwear agent, 0.1 to 1.0% by weight of an anticorrosive, and 0 to 2% by weight, especially 0.1 to 1.5% by weight, of an ionic liquid.
The ester compound of formula (I) present in the high-temperature oil is preferably selected from the group consisting of esters of trimellitic acid, pyromellitic acid, trimesic acid or mixtures thereof. The compound of the general formula (II) is a derivative of phloroglucinol (benzene-1,3,5-triol), preferably phloroglucinol trioctanoate, phloroglucinol tridecanoate and phloroglucinol tridodecanoate.
The antioxidant present in the high-temperature oil, which may contain sulfur and/or nitrogen and/or phosphorus in the molecule, is selected from the group consisting of aromatic aminic antioxidants such as alkylated phenyl-alpha-naphthylamine, dialkyldiphenylamine, sterically hindered phenols such as butylhydroxytoluene (BHT), phenolic antioxidants having thioether groups, zinc dialkyldithiophosphates or molybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates, and phosphites.
The antiwear agent present in the high-temperature oil is selected from the group consisting of antiwear additives based on diphenyl cresyl phosphate, amine-neutralized phosphates, alkylated and nonalkylated triaryl phosphates, alkylated and nonalkylated triaryl thiophosphates, zinc dialkyldithiophosphates or molybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates, carbamates, thiocarbamates, zinc dithiocarbamates or molybdenum dithiocarbamates or tungsten dithiocarbamates, dimercaptothiadiazole, calcium sulfonates and benzotriazole derivatives.
The anticorrosive present in the high-temperature oil is selected from the group consisting of additives based on “overbased” calcium sulfonates having a TBN of 100 to 300 mg KOH/g, amine-neutralized phosphates, alkylated calcium naphthalenesulfonates, oxazoline derivatives, imidazole derivatives, succinic monoesters, N-alkylated benzotriazoles.
The ionic liquid (IL) used in the high-temperature oil comprises what are called salt melts which, by definition, are liquid at temperatures below 100° C. Many ionic liquids are also liquid at room temperature or at lower temperatures. Suitable cations for ionic liquids have been found to be a quaternary ammonium cation, a phosphonium cation, an imidazolium cation, a pyridinium cation, a pyrazolium cation, an oxazolium cation, a pyrrolidinium cation, a guanidinium cation, a morpholinium cation or a triazolium cation, which may be combined with an anion selected from the group consisting of [PF₆]⁻, [BF₄]⁻, [CF₃CO₂]⁻, [CF₃SO₃]⁻. [(CF₃SO₂)₂N]⁻, [(R⁴SO₂) (R⁵SO₂)N]⁻, [(CF₃SO₂) (CF₃COO)N]⁻, [R⁴—SO₃]⁻, [R⁴—O—SO₃]⁻, [R⁴—COO]⁻, Cl⁻, Br⁻, [NO₃]⁻, [N(CN)₂]⁻, [HSO₄]⁻, or [R⁴R⁵PO₄]⁻, and the R⁴and R⁵radicals are each independently selected from hydrogen; linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbon atoms; heteroaryl groups, heteroaryl-C₁-C₆-alkyl groups having 3 to 8 carbon atoms in the heteroaryl radical and at least one heteroatom from N, O and S which may be substituted by at least one group selected from C₁-C₆-alkyl groups and/or halogen atoms; aryl groups, aryl-C₁-C₆-alkyl groups having 5 to 12 carbon atoms in the aryl radical, which may be substituted by at least one C₁-C₆-alkyl group, partly and fully fluorinated alkyl radicals. However, further combinations are also possible. Anions of [PF_(6-x)R⁷ _x], [R⁷—SO₃]⁻ type are also known. R⁷here represents partly or fully fluorinated radicals such as pentafluoroethyl or perfluorobutyl.
The following anion type is likewise quite thermally stable: (FSO₂)₂N.
In order to display positive action in oils, the ionic liquids should firstly show solubility in the oils, although complete miscibility is not absolutely necessary. The ionic liquids should be thermally stable and not promote corrosion, for example by forming reaction products which are noncorrosive or corrosive only in a very delayed manner in the presence of water.
Particularly advantageous ionic liquids have been found to be those such as tetraalkylammonium bis(trifluoromethylsulfonyl)imides and tetraalkylphosphonium bis(trifluoromethylsulfonyl)imides, for example trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (HPDimide) and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide (Moimide). Ionic liquids which have likewise been found to be particularly advantageous are those such as tetraalkylammonium tris(perfluoroethyl)trifluorophosphate and tetraalkylphosphonium tris(perfluoroethyl)trifluorophosphate, for example tetrabutylphosphonium tris(perfluoroethyl)trifluorophosphate (BuPPFET), trihexyl(tetradecyl) tris(perfluoroethyl)trifluorophosphate (HDPPFET). It has likewise been found that pyrrolidinium tris(perfluoroethyl)trifluorophosphates are particularly advantageous. Also particularly advantageous are tetraalkylammonium perfluorobutanesulfonates and tetraalkylphosphonium perfluorobutanesulfonates such as trihexyl(tetradecyl)phosphonium perfluorobutanesulfonate (HDPnonaflate).
It is also possible to use any desired mixtures of the ionic liquids.
The inventive two-component system has a much higher performance in terms of thermal stability and residue formation or residue characteristics. The enormous rise in thermal stability is manifested particularly in a distinct increase in lubrication characteristics. The relubrication intervals were extended and an energy saving of up to a 30% power saving was achieved.
As already mentioned, the formation of residues is distinctly reduced. As a result, the formation of cracking residues is also reduced and the residues formed can be very easily dissolved with fresh oil.

The appended figures show the advantages of the inventive high-temperature oil based on two components.

FIG. 1 shows the friction values as a function of temperature at a load of 250 N for an inventive high-temperature oil based on two components from example 1 compared with a known oil based on three components from comparative example 1 at a kinematic viscosity at 40° C. of about 260 mm²/sec;

FIG. 2 shows the vaporization losses for an inventive high-temperature oil based on two components from example 1 compared with a known oil based on three components from comparative example 1 at a kinematic base oil viscosity at 40° C. of about 260 mm²/sec;

FIG. 3 shows the increase in the apparent dynamic viscosity of an inventive high-temperature oil based on two components from example 1 compared with a known oil based on three components from comparative example 1 at a kinematic base oil viscosity at 40° C. of about 260 mm²/sec;

FIG. 4 shows the friction values as a function of temperature at a load of 250 N for an inventive high-temperature oil based on two components from example 2 compared with a known oil based on three components from comparative example 2;

FIG. 5 shows the vaporization losses for an inventive high-temperature oil based on two components from example 2 compared with a known oil based on three components from comparative example 2 at a kinematic base oil viscosity at 40° C. of about 100 mm²/sec;

FIG. 6 shows the increase in the apparent viscosity of an inventive high-temperature oil based on two components from example 2 compared with a known oil based on three components from comparative example 2 at a kinematic base oil viscosity at 40° C. of about 100 mm²/sec;

FIG. 7 shows the friction values as a function of temperature at a load of 250 N for an inventive high-temperature oil based on two components from example 3 compared with a known oil based on three components from comparative example 3;

FIG. 8 shows the vaporization losses for an inventive high-temperature oil based on two components from example 3 compared with a known oil based on three components from comparative example 3 at a kinematic base oil viscosity at 40° C. of about 680 mm²/sec;

FIG. 9 shows the increase in the apparent dynamic viscosity of an inventive high-temperature oil based on two components from example 3 compared with a known oil based on three components from comparative example 3 at a kinematic base oil viscosity at 40° C. of about 680 mm²/sec;

FIG. 10 shows the vaporization losses for an inventive high-temperature oil based on two components with an ionic liquid from example 4 compared with comparative example 4, which corresponds to example 1 at a kinematic base oil viscosity of about 260 mm²/sec;

FIG. 11 shows the increase in the apparent dynamic viscosity of an inventive high-temperature oil based on two components with an ionic liquid from example 4 compared with comparative example 4, which corresponds to example 1 at a kinematic base oil viscosity of about 260 mm²/sec;

FIG. 12 shows the experimental setup for the high-performance chain test bed.

The invention is now illustrated in detail by the examples which follow.

EXAMPLE 1

Production of an inventive two-component high-temperature oil
Composition of the high-temperature oil:
63.4% by weight of aromatic trimellitic ester
30.0% by weight of fully hydrogenated polyisobutylene
3.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.1% by weight of anticorrosive
As the aromatic ester, trimellitic ester is initially charged in a stirred tank. At 100° C., the polyisobutylene is added while stirring. Subsequently, the mixture is stirred for one 1 hour in order to obtain a homogeneous mixture. The antiwear agent and the antioxidant are added to the tank at 60° C. while stirring. After about 1 hour, the finished oil can be dispensed into the containers provided.

COMPARATIVE EXAMPLE 1

Production of a known three-component high-temperature oil
Composition of the high-temperature oil:
47.4% by weight of aromatic trimellitic ester
16.0% by weight of polyisobutylene
30.0% by weight of synthetic hydrocarbon
3.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.1% by weight of anticorrosive
As the aromatic ester, trimellitic ester is initially charged in a stirred tank together with the poly-α-olefin as the synthetic hydrocarbon. At 100° C., the polyisobutylene is added while stirring. Subsequently, the mixture is stirred for 1 hour in order to obtain a homogeneous mixture. The antiwear agent and the antioxidant are added to the tank at 60° C. while stirring. After about 1 hour, the finished oil can be dispensed into the containers provided.
The advantages of the inventive high-temperature oil are shown hereinafter.
The base data for the oil according to example 1 and comparative example 1 are shown in table 1.

TABLE 1

		Comparative
	Example 1	example 1

Appearance

clear

Kinematic viscosity	271	mm²/sec	275	mm²/sec
40° C.
Kinematic viscosity	24	mm²/sec	25	mm²/sec
100° C.
Flashpoint	>250°	C.	>250°	C.
Pour point	−30°	C.	−30°	C.

1.1. Thermal Stability Studies
Studies were conducted with regard to vaporization and viscosity under thermal stress on a starting weight of 5 g in an aluminum pan at 230° C. For this purpose, the oils according to example 1 and comparative example 1 were compared with one another.

	TABLE 2

		Comparative
	Example 1	example 1

Vaporization loss	16%	30%
after 24 h/230° C.
Vaporization loss	25%	49%
after 48 h/230° C.
Vaporization loss	35%	62%
after 72 h/230° C.

Increase in	970 mPas	1300	mPas
apparent dynamic
viscosity after
24 h/230° C.
Increase in	1400 mPas	4400	mPas
apparent dynamic
viscosity after
48 h/230° C.
Increase in	3200 mPas	41 000	mPas
apparent dynamic
viscosity after
72 h/230° C.

The above results show that the use of fully hydrogenated polyisobutylene in a two-component high-temperature oil can distinctly reduce the rise in viscosity and in the vaporization loss compared to the known three-component oil. These results are also shown in the form of graphs in FIGS. 2 and 3.
1.2. Comparison of the Friction Values
The oils produced in example 1 and comparative example 1 were used for determination of the friction values. For this purpose, an oscillating frictional wear test (SRV) was conducted based on DIN 51834, ball/disk test condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165 min. The results are shown in table 3.

TABLE 3

		Comparative
	Example 1	example 1
SRV TST 250N point	Friction number	Friction number

50 to 120° C.	0.104	0.109
to 140° C.	0.105	0.109
to 160° C.	0.102	0.118
to 180° C.	0.096	0.128
to 200° C.	0.090	0.138
to 210° C.	0.087	0.145
to 220° C.	0.087	0.151
to 230° C.	0.091	0.159
to 240° C.	0.102	0.166
to 250° C.	0.110	0.169

These results, which are also shown in FIG. 1, show the positive effect of the high-temperature oil based on two components on the friction number compared to the three-component system.
1.3. Residue Characteristics After Complete Vaporization of the Oil at 250° C.
The formation of residues and the behavior of the residues with regard to solubility were studied.
The oil to be tested is weighed to 5 g onto a steel sheet which has been bent to size and cleaned with solvent beforehand, and then vaporized off at 250° C. in an air circulation drying cabinet for min. 72 h. The square sheet is bent manually on all four sides, so as to give a dish shape.
After cooling, the results of the re-weighing are documented.
Important features for this test are the determination of the dissolvability of the residue surface with fresh oil and the amount of residue formed. For this purpose, a drop of the fresh oil is applied to the residue and rubbed in gently by means of a rounded glass rod with circular movements.
The results show that the inventive high-temperature oil forms a lower level of residue at 4.8% than the known oil, which has a residue of 6.0%. The residue formed from the inventive high-temperature oil has very good surface dissolvability, which means that these residues are easy to dissolve with fresh oil. In contrast, the residue of the known oil has much poorer surface redissolvability with fresh oil.
1.4. High-Performance Chain Test Bed
FIG. 12 shows the high-performance chain test bed, which works under the following test conditions:
Temperature: 220° C.
Speed: 2 m/sec
Load: 2600 N
Run time after 0.1% chain lengthening 22 hours for example 1, and 17 hours for comparative example 1.
Before the test, the chain is immersed into the lubricant oil to be tested. After the immersion, the chain is suspended, such that the excess lubricant can drip off. Subsequently, the chain is installed into the chain test bed (see FIG. 10) and the test is started under the conditions defined. It is possible to vary the temperature, the speed and the load.
The run time is fixed at a chain lengthening of 0.1%. The lengthening of the chain arises through wear at the chain members during the test run.

EXAMPLE 2

Composition of the inventive high-temperature oil:
82% by weight of aromatic trimellitic ester
12.7% by weight of fully hydrogenated polyisobutylene
0.3% by weight of antiwear agent
4.5% by weight of antioxidant
0.5% by weight of anticorrosive
The production is effected as described in example 1.

COMPARATIVE EXAMPLE 2

Composition of the three-component high-temperature oil:
55.7% by weight of aromatic trimellitic ester
7% by weight of polyisobutylene
33.20% by weight of synthetic hydrocarbon
0.30% by weight of antiwear agent
3.7% by weight of antioxidant
0.10% by weight of anticorrosive
The production is effected as described in comparative example 1.
The advantages of the inventive high-temperature oil are shown hereinafter.
The base data for the oil according to example 2 and comparative example 2 are shown in table 4.

TABLE 4

Viscosity at 40° C.,		Comparative
100 mm²/sec	Example 2	example 2

Appearance

clear

Kinematic viscosity	120.0	mm²/sec	107.0	mm²/sec
40° C.
Kinematic viscosity	14	mm²/sec	13.5	mm²/sec
100° C.
Flashpoint	>250°	C.	>250°	C.
Pour point	−20°	C.	−30°	C.

2.1. Thermal Stability Studies
Studies were conducted with regard to the vaporization and viscosity under thermal stress on a starting weight of 5 g in an aluminum pan at 230° C. For this purpose, the oils according to example 2 and comparative example 2 were compared with one another.

	TABLE 5

		Comparative
	Example 2	example 2

Vaporization loss	18%	36%
after 24 h/230° C.
Vaporization loss	37%	57%
after 48 h/230° C.
Vaporization loss	52%	71%
after 72 h/230° C.

Increase in	340 mPas	430	mPas
apparent dynamic
viscosity after
24 h/230° C.
Increase in	1250 mPas	200	mPas
apparent dynamic
viscosity after
48 h/230° C.
Increase in	4700 mPas	23 000	mPas
apparent dynamic
viscosity after
72 h/230° C.

The above results show that the use of fully hydrogenated polyisobutylene in a two-component high-temperature oil can distinctly reduce the rise in viscosity and in the vaporization loss compared to the known three-component oil. These results are also shown as graphs in FIGS. 5 and 6.
2.2. Comparison of the Friction Values
The oils produced in example 2 and comparative example 2 were used to determine the friction values. For this purpose, an oscillating frictional wear test (SRV) was conducted based on DIN 51834, ball/disk test condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165 min.
The results are shown in table 6.

TABLE 6

		Comparative
	Example 2	example 2
SRV TST 250N point	Friction number	Friction number

50 to 120° C.	0.097	0.105
to 140° C.	0.093	0.112
to 160° C.	0.122	0.129
to 180° C.	0.133	0.136
to 200° C.	0.138	0.143
to 210° C.	0.139	0.157
to 220° C.	0.136	0.175
to 230° C.	0.138	0.186
to 240° C.	0.136	0.196
to 250° C.	0.136	0.205

These results, which are also shown in FIG. 4, show the positive effect of the high-temperature oil based on two components on the friction number compared to the three-component system.
2.3. Residue Characteristics after Complete Vaporization of the Oil at 250° C.
The formation of residues and the behavior of the residues in terms of solubility were studied. The method is described in example 1.
Both the inventive high-temperature oil and the known oil had a residue of 3.0%; the residue formed from the inventive high-temperature oil had very good surface dissolvability, which means that these residues can be dissolved easily with fresh oil. In contrast, the residue of the known oil has much poorer surface redissolvability with fresh oil.
2.4. High-Performance Chain Test Bed
The test on the high-performance chain test bed was conducted at 220° C., a speed of 2.0 m/sec and a load of 2600 N. The run time after chain lengthening 0.1% is 19 h for example 2, and that for comparative example 2 is 17 h.
The test was conducted as described in example 1.

EXAMPLE 3

Composition of the Inventive High-Temperature Oil:
45.4% by weight of aromatic trimellitic ester
48.00% by weight of fully hydrogenated polyisobutylene
2.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.1% by weight of anticorrosive
The production was effected as described in example 1.

COMPARATIVE EXAMPLE 3

Composition of the Three-Component High-Temperature Oil:
47.0% by weight of aromatic trimellitic ester
17.4% by weight of polyisobutylene
29.0% by weight of synthetic hydrocarbon
3.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.10% by weight of anticorrosive
The production was effected as described in comparative example 1.
The advantages of the inventive high-temperature oil are shown hereinafter.
The base data for the oil according to example 3 and comparative example 3 are shown in table 7.

TABLE 7

Viscosity at 40° C.,		Comparative
680 mm²/sec	Example 3	example 3

Appearance

clear

Kinematic viscosity	690	mm²/sec	690	mm²/sec
40° C.
Kinematic viscosity	24	mm²/sec	47	mm²/sec
100° C.
Flashpoint	>250°	C.	>250°	C.
Pour point	−30°	C.	−30°	C.

3.1. Thermal Stability Studies
Studies were conducted with regard to vaporization and viscosity under thermal stress on a starting weight of 5 g in an aluminum pan at 230° C. For this purpose, the oils according to example 3 and comparative example 3 were compared with one another.

TABLE 8

		Comparative
	Example 3	example 3

Vaporization loss	18%	20%
after 24 h/230° C.
Vaporization loss	28%	38%
after 48 h/230° C.
Vaporization loss	37%	53%
after 72 h/230° C.

Increase in	3400	mPas	2800	mPas
apparent dynamic
viscosity after
24 h/230° C.
Increase in	6000	mPas	13 250	mPas
apparent dynamic
viscosity after
48 h/230° C.
Increase in	12 700	mPas	47 000	mPas
apparent dynamic
viscosity after
72 h/230° C.

The above results show that the use of fully hydrogenated polyisobutylene in a two-component high-temperature oil can reduce the rise in viscosity and in the vaporization loss compared to the known three-component oil. These results are also shown as graphs in FIGS. 8 and 9.
3.2. Comparison of the Friction Values
The oils produced in example 3 and comparative example 3 were used to determine the friction values. For this purpose, an oscillating frictional wear test (SRV) was conducted based on DIN 51834, ball/disk test condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165 min.
The results are shown in table 9.

TABLE 9

		Comparative
	Example 3	example 3
SRV TST 250N point	Friction number	Friction number

50 to 120° C.	0.119	0.118
to 140° C.	0.116	0.115
to 160° C.	0.119	0.114
to 180° C.	0.115	0.110
to 200° C.	0.105	0.108
to 210° C.	0.098	0.105
to 220° C.	0.096	0.102
to 230° C.	0.099	0.102
to 240° C.	0.112	0.089
to 250° C.	0.126	0.086

These results, which are also shown in FIG. 7, show the positive effect of the high-temperature oil based on two components on the friction number compared to the three-component system.
3.3. Residue Characteristics After Complete Vaporization of the Oil at 250° C.
The formation of residues and the behavior of the residues in terms of solubility were studied. The test was conducted as described in example 1.
The results show that the inventive high-temperature oil forms a lower level of residues at 4.8% than the known oil, which has a residue of 11.8%. The residue formed from the inventive high-temperature oil has very good surface dissolvability, which means that these residues can be dissolved easily with fresh oil. In contrast, the residue of the known oil has much poorer surface redissolvability with fresh oil.
3.4. High-Performance Chain Test Bed
The test on the high-performance chain test bed was conducted at 220° C., a speed of 2.0 m/sec and a load of 2600 N. The run time after chain lengthening 0.1% was 17 h for example 3 and 15 h for comparative example 3. The test was conducted as described in example 1.

EXAMPLE 4

Composition of the Inventive High-Temperature Oil:
62.90% by weight of aromatic trimellitic ester
30.00% by weight of fully hydrogenated polyisobutylene
3.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.1% by weight of anticorrosive
0.50% by weight of ionic liquid
The production was effected as described in example 1.
The ionic liquid used was HDP imide (=trihexyl(tetradey-phosphonium bis(trifluoromethylsulfonyl)imide).

COMPARATIVE EXAMPLE 4

Corresponds to Example 1

Composition of the inventive high-temperature oil:
63.40% by weight of aromatic trimellitic ester
30.00% by weight of fully hydrogenated polyisobutylene
3.5% by weight of antiwear agent
3.0% by weight of antioxidant
0.1% by weight of anticorrosive
The production was effected as described in example 1.
The base data for the oil according to example 4 and comparative example 4 are shown in table 10.

TABLE 10

Viscosity at 40° C.,		Comparative example 4
200 mm²/sec	Example 4	(corresponds to ex. 1)

Appearance	clear	clear

Kinematic viscosity	270.0	mm²/sec	271.0	mm²/sec
40° C.
Kinematic viscosity	24	mm²/sec	25	mm²/sec
100° C.
Flashpoint	>250°	C.	>250°	C.
Pour point	−30°	C.	−30°	C.

4.1. Thermal Stability Studies
Studies were conducted with regard to the vaporization and viscosity under thermal stress on a starting weight of 5 g in a closed aluminum pan at 250° C. The vaporization loss after 72 h/250° C. was 19%. The increase in apparent dynamic viscosity in mPas after 72 h/250° C. was 2300 mPas.

	TABLE 11

		Comparative example 4
	Example 4	Corresponds to example 1

Vaporization loss	19%	46%
after 72 h/250° C.
Increase in	2300 mPas	27 000 mPas
apparent dynamic
viscosity after
72 h/250° C.

The above results show that the use of HDP imide can once again significantly improve the thermal stability of a two-component system. These results are also shown as graphs in FIGS. 10 and 11.

EXAMPLE 5

Composition of the Inventive High-Temperature Oil:
63.5% phloroglucinol tridecanoate
30.0% fully hydrogenated polyisobutylene
3.5% antiwear agent
3.0% antioxidant
0.1% by weight of anticorrosive
The production was effected as described in example 1.
It was also possible to obtain the results described in detail above with the high-temperature oil based on a derivative of phloroglucinol.
The above experimental results show that the inventive high-temperature oil in all studies conducted gave much better values than in the case of the known high-temperature oils.
In summary, it can be stated that the inventive two-component system has much higher performance with regard to thermal stability and residue formation or residue characteristics. The enormous rise in thermal stability is manifested particularly in a distinct rise in lubrication characteristics. The relubrication intervals were extended and an energy saving of up to a 30% power saving was achieved.

Claims

1. A high-temperature oil for lubrication of chains, chain rollers and belts of continuous presses, comprising

40 to 91.9% by weight of an aromatic ester of the general formula (I)

where R1 is a linear or branched alkyl group having 6 to 16 carbon atoms and n is an integer of 3 to 4,

or 40 to 91.9% by weight of a compound of the general formula (II)

where R is a linear or branched alkyl group having a chain length of 8 to 16 carbon atoms and n is equal to 3,

and 5 to 50% by weight of a hydrogenated polyisobutylene, of a fully hydrogenated polyisobutylene or of a mixture of a fully hydrogenated and a hydrogenated polyisobutylene.

2. The high-temperature oil as claimed in claim 1, further comprising 0.1 to 6% by weight of an antioxidant.

3. The high-temperature oil as claimed in claim 1, further comprising 1 to 4% by weight of an antiwear agent.

4. The high-temperature oil as claimed in claim 1, further comprising 0.1 to 0.5% by weight of an anticorrosive.

5. The high-temperature oil as claimed in claim 1, further comprising 0 to 2% by weight of an ionic liquid.

6. The high-temperature oil as claimed in claim 1, wherein the ester compound of the general formula (I) is selected from the group consisting of esters of trimellitic acid, pyromellitic acid, trimesic acid or of a mixture thereof.

7. The high-temperature oil as claimed claim 1, wherein the compound of the general formula (II) is a derivative of phloroglucinol (benzene-1,3,5-triol).

8. The high-temperature oil as claimed in claim 7, in which the derivative of phloroglucinol is phloroglucinol trioctanoate, phloroglucinol tridecanoate or phloroglucinol tridodecanoate.

9. The high-temperature oil as claimed in claim 2, wherein the antioxidant bears sulfur and/or nitrogen and/or phosphorus in the molecule, and is selected from the group consisting of aromatic aminic antioxidants such as alkylated phenyl-alpha-naphthylamine, dialkyldiphenylamine, sterically hindered phenols such as butylhydroxytoluene (BHT), phenolic antioxidants having thioether groups, zinc dialkyldithiophosphates or molybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates, and phosphites.

10. The high-temperature oil as claimed in claim 3, wherein the antiwear agent is selected from the group consisting of antiwear additives based on diphenyl cresyl phosphate, amine-neutralized phosphates, alkylated and nonalkylated triaryl phosphates, alkylated and nonalkylated triaryl thiophosphates, zinc dialkyldithiophosphates or molybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates, carbamates, thiocarbamates, zinc dithiocarbamates or molybdenum dithiocarbamates or tungsten dithiocarbamates, dimercaptothiadiazole, calcium sulfonates and benzotriazole derivatives.

11. The high-temperature oil as claimed in claim 4, wherein the anticorrosive is selected from the group consisting of additives based on overbased calcium sulfonates, amine-neutralized phosphates, alkylated calcium naphthalenesulfonates, oxazoline derivatives, imidazole derivatives, succinic monoesters, N-alkylated benzotriazoles.

12. The high-temperature oil as claimed in claim 5, wherein the ionic liquid is selected from the group consisting of tetraalkylammonium bis(trifluoromethylsulfonyl)imides and tetraalkylphosphonium bis(trifluoromethylsulfonyl)imides, for example trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (HPDimide) and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide (Moimide), and tetraalkylammonium tris(perfluoroethyl)trifluorophosphate and tetraalkylphosphonium tris(perfluoroethyl)trifluorophosphate, especially tetrabutylphosphonium tris(perfluoroethyl)trifluorophosphate (BuPPFET), trihexyl(tetradecyl) tris(perfluoroethyl)trifluorophosphate (HDPPFET), pyrrolidinium tris(perfluoroethyl)trifluorophosphates, tetraalkylammonium, tetraalkylphosphonium perfluorobutanesulfonates, trihexyl(tetradecyl)phosphonium perfluorobutanesulfonate (HDPnonaflate).

13. The use of the high-temperature oil as claimed in any of claim 1 for industrial chain lubrication in conveying systems, painting lines, the textile industry, the insulating materials industry, the glass industry, or for belt lubrication in continuous wood pressing plants.

14. The high-temperature oil as claimed in claim 2, further comprising 1 to 4% by weight of an antiwear agent.

15. The high-temperature oil as claimed in claim 2, further comprising 0.1 to 0.5% by weight of an anticorrosive.

16. The high-temperature oil as claimed in claim 3, further comprising 0.1 to 0.5% by weight of an anticorrosive.

17. The high-temperature oil as claimed in claim 2, further comprising 0 to 2% by weight of an ionic liquid.

18. The high-temperature oil as claimed in claim 3, further comprising 0 to 2% by weight of an ionic liquid.

19. The high-temperature oil as claimed in claim 4, further comprising 0 to 2% by weight of an ionic liquid.