DE2733714A1 - LIQUID ANTIOXIDANTS WITH IMPROVED SOLUBILITY IN LUBRICANTS - Google Patents

Description

TLEDTKE - BüHLING - KlNNK - GROUP

273371A 3

Patent attorney:

Dipl.-Ing. Tiedtke Dipl.-Chem. Bühling Dipl.-Ing. Kinne Dipl.-Ing. Grupe Bavarlarlng 4, Postfach 20 24 8000 Munich 2 Tel.:(089)539653-56 Telex: 524 845tipat cable. Germaniapatent Munich

July 26, 1977 B 8326 / case F-5407

UNIROYAL, INC. New York, N.Y., USA

Liquid antioxidants with improved solubility in lubricating oils

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The products according to the invention are liquids, which is easily mixed with oil and in the oil in the right Quantities can be dissolved directly without the need for heating. This leads to a desirable Time and energy savings. Another advantage of such liquid compositions is that they are easier to handle compared to crystalline compositions. Liquids can be stored easily and in the right place Quantities are pumped into the end product. The correct amount can be obtained either by weighing, or what is more convenient is to be determined by measuring the volume.

Although not ordinarily necessary, concentrates of these liquid compositions can if desired for the purpose of adding to the oil, since these products in all proportions both in Liquid hydrocarbons as well as liquid esters are soluble and miscible with them even at low temperatures are. For example, 50% solutions can easily be prepared by simply mixing at room temperature. The solutions remain homogeneous even with strong cooling.

Typical oils produced by the invention Antioxidants that can be protected are:

1. All mineral oils.

2. Synthetic, by polymerizing 1-olefins such as hexene (1), octene (1), decene (1), dodecene (1) or isobutylene produced hydrocarbon oils.

3. Synthetic, liquid esters based on one or more organic carboxylic acid esters, intended for use at an operating temperature of 2O4 ° C (400 ° F) or above.

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Examples of such synthetic lubricants are lubricants based on a Diesters of a dibasic acid and a monohydric alcohol, for example dioctyl sebacate or dinonyl adipate, a lubricant based on a triester of Trimethylolpropane and a monobasic acid or mixture of monobasic acids, for example Trimethylolpropane tripelargonate or trimethylolpropane tricaprylate, lubricant based a tetraester of pentaerythritol and a monobasic acid or a mixture of monobasic acids Acids, for example pentaerythritol tetracaprylate or lubricants based on complexes Esters of monobasic acids, dibasic acids and polyhydric alcohols or lubricants based on mixtures of the esters described above.

The following formulas are an example of the structures used according to the invention:

where the groups R denote wiped propylene trimers.

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Such connections can be made by one either ot ~ or ß-phenylnaphthylamine of exposure a mixture of propylene trimers and a Friedel-Crafts catalyst such as aluminum chloride, boron trifluoride and the like Exposes catalytic converters. The reaction can be carried out in a temperature range from room temperature up to 300 ° C will. The reaction is preferably carried out in an inert atmosphere, but the inert atmosphere is not essential. The product prepared according to the invention contains an alkylating moiety selected from a large number d. H. consists of at least 30 isomers that are propylene trimers. The following structures are typical:

CH ₂ - 6 —CII ₂ - CH - CII ₂ - CH ₂ - CH-CH-CH-CH-

PI ³ I ³

CH ₂ = C - CH ₂ - CH - CH - CH ₃

fj f3 f3
CH ₂ = C - CH - CH ₂ - CH - CII

CH ₃ CH ₃

CH. «C - CH - CH - CH - CH - CH 2 2 2 2 3

CH ₃ CH ₃
CH ₃ -C - CH ₂ - CH - CH s = CH - CH-

CH ₃ CH ₃
- i - CH ₂ - CH - CH- CH «

CH- i - CH ₂ - CH - CH - CH «CH

and similar structures.

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Although it is possible that not all of olefins, which are present in such a mixture, phenyl naphthylamines can be alkylated in the manner described above, so even a large number of olefins is still capable in such a mixture to react to form alkylation. Evidence that the resulting alkylated phenylnaphthylamines are mixtures of various isomers is provided below in connection with a detailed description of the drawings.

The fact that the reaction product is actually a mixture of isomeric compounds, in contrast to the pure, simple connections described according to the prior art, and the asymmetry of the introduced Alkyl groups prevent crystallization of the product using a more pure, more symmetrical compound would have been achieved.

The following can be said about the drawings:

Figure 1 is a gas chromatogram of the mixed propylene trimers (nonene mixture) used in accordance with the present invention were used,

Fig. 2 is a liquid chromatogram of a

distilled nonylphenyl-od-naphthylamine.

In Figs. 1A and 1B, the abscissa units are in minutes expressed, with each division corresponding to two minutes. The units of the ordinate scale are expressed in mV. Each peak corresponds to a single isomer and the total area under each peak is directly proportional to the amount in which the isomer in question is in

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the total mixture is present.

Figs. 1A and 1B are based on a diagram shown at the evaluation of the pro * e in a gas chromatograph (Perkin Elmer 226) was obtained. The device contains a Golay column (91.4 m χ 0.25 mm), which contains 95% squalene and 5% a surface-active substance (designated with ATPET-80) is occupied. The column temperature was 75 ° C. One microliter of the sample was introduced into the injection block of the device, keeping the block at 90 ° C. The following gases with the specified pressures were used:

H ₂ (0.82 atm), air (2.3 atm) and He (2.7 atm).

FIG. 2 is based on a diagram which was obtained when evaluating samples in a liquid chromatograph (DuPont 830). This liquid chromatograph contains a Zorbax ODS column with a length of 0.25 m and an inner diameter of 4.6 mm. The column is packed with a material made by chemically attaching octadecylsilane groups to particles of Zorbax-SIL. The resulting particles containing octadecylsilane groups in chemical bond are spherical and have a diameter of 6 μm to 8 μm. The ordinate and abscissa scales are expressed in the same units as in FIG.

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In all figures, the diagrams are from right (where, according to the course of time, the first peak arose) to left (where the last peak originated) to read.

As mentioned above, alkylated phenylnaphthylamines are prepared by reacting an alkene (R) with phenylnaphthylamine under catalysis by a Friedel-Crafts catalyst such as AlCl or BF _3.

Al Cl.

Obviously, a single, discrete alkylation product is formed if R is a single, discrete connection. Just as obvious is the fact that there is a mixture of alkylation products is formed when R is a mixture of compounds.

In US Patent 3414618 (Example 1), the alkylation of N-phenyl- OC -naphthylamine with a mixture of 75% 2,4,4, -trimethylpentene- (1) and 25% 1,4,4-trimethylpentene- (2).

In fact, only the first of the two isomers is chemically capable of alkylating phenyl-oC-naphthylamine, so that a single alkylation product arises with the following individual structure:

f ₃

- C CHo

I ⁵

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The fact that it is a single compound is indicated by its sharp melting point (76 ° C - 77 ° C, a mixture of compounds would melt over a wide range) and evidenced by Fig. 3 that a single, very showing narrow peak.

In contrast, that is produced according to the invention Alkylation product the result of the reaction of a mixture of alkenes (R), so that also the alkylation product necessarily represents a mixture of compounds. 1A and 1B represent the gas chromatogram according to the invention for the Alkylation of phenylnaphthylamines used mixed propylene trimers. As can be clearly seen, more than 30 Isomers are present in the mixture in large quantities, but not a single one of these isomers reaches a proportion of also only 10% of the total. In connection with Example 1, described below, it should be noted that a twofold molar excess of the mixed trimers is used, since some of the types of isomers present belong to those which are not able to alkylate the pheny! naphthylamines. Since the reaction, as the analysis of the reaction product shows, an almost quantitative amount of monoalkylation product is achieved, it is statistically necessary that a variety of alkylation products be formed. Fig. 2 gives an indication of the number of products available. There is no doubt that the main peak in FIG corresponds to a mixture of isomers. A good resolution could not be obtained because the connections are mutually exclusive are extremely similar, but comparison of the width of this major peak with the peak of Figure 3 shows that the Main peak of Figure 2 is two to three times as wide, suggesting a multitude of isomers present. How one can see directly, there are approximately 6 isomers in the mixture in smaller quantities that are strong enough of

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distinguish between the main components so that they can be clearly separated using the chromatography process used. The fact that the product produced by this invention is a liquid, the statistics and Fig. 3 support the position that the reaction product produced by this invention is a mixture of isomers.

The inventively produced, alkylated phenyl naphthylamines are generally used in an amount between 0.05 and 4 parts, preferably between 0.2 and 2.5 parts per 100 parts of the lubricating oil, the lubricating oil that is to be stabilized, added.

The following examples serve to explain the process according to the invention for the preparation of the compounds described in more detail.

example 1

In a three-necked round bottom flask equipped with a stirrer, reflux condenser and thermometer, 109.5 g (0.5 mol) of phenyl-et- naphthylamine and 126 g (1 mol) of the mixed propylene trimers were combined. A static pressure gradient was maintained in the upper part of the condenser with nitrogen. 1.5 g of AlCl- were added and the mixture was heated to 120 ° C. This temperature was maintained for 24 hours. Thereafter , the reaction mixture was allowed to cool to room temperature and 300 ml of hexane was added. The resulting solution was filtered off to remove insoluble traces of the catalyst and then washed twice with 300 ml portions of 5% sodium hydroxide solution. The hexane solution was washed with water until it became neutral. The solution was dried with MgSO ₄ and the MgSO ₄ was then separated by filtration . The hexane and the excess

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Propylene trimers were distilled off under atmospheric pressure. Finally, a temperature of Reached 250 ° C, whereupon a vacuum of 20 mm was applied to the complete removal of the excess Ensure propylene trimers. The piston residue weighed 165 g. The theoretical yield for a complete monoalkylation is 172 g. The residue was a syrup, which at -78 ° C neither as such nor from a 10% solution crystallized in hexane. The analysis of the piston residue resulted in:

Calculated: (C ₂₅ H ₃₁ N): C: 86.96%; H: 8.98%; N: 4.06% Found: C: 87.76%; H: 8.89%; N: 4.10%.

As can be seen from the analysis, the product consists essentially of monoalkylated phenyl-oG-naphthylamine. Of the Piston residue can almost completely under a vacuum of 0.08 mm in the temperature range between 185 ° C and 188 ° C Distilled off to form a pale cherry red liquid.

Example 2

The procedure described in Example 1 was followed with the difference that phenyl-β-naphthylamine was used became. A mixture of liquid, alkylated phenyl-ß-naphthylamines was obtained.

Example 3

To 100 parts of a liquid from the synthetic Ester trimethylolpropane triheptanoate was 1.5 parts of the

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The reaction product of i added services described above example. The resulting mixture was found to have excellent antioxidant properties when aging was carried out at elevated temperatures.

Example 4

2.5 parts of the reaction product of Example 1 described above were added to 100 parts of mineral oil. By an aging test at elevated temperatures showed that the resulting mixture had excellent antioxidant properties receives.

Example 5

2.0 parts of the reaction product of Example 2 described above was made into 100 parts of a liquid synthetic polyoctene given. An aging test carried out at elevated temperatures showed that the resulting mixture has excellent antioxidant properties.

Example 6

2.0 parts of the reaction product of Example 1 described above were made up to 100 parts of a liquid synthetic polydecene. Aging at elevated temperatures showed the resulting mixture to be excellent Preserves antioxidant properties.

Example 7

1.7 parts of the reaction product of Example 1 described above became 100 parts of a mixture of

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25 parts of polyoctene and 75 parts of trimethylolpropane triheptanoate are added. Aging at elevated temperatures found the resulting mixture to have excellent antioxidant properties Has.

Example 8

1.7 parts of the reaction product of Example 2 described above became 100 parts of a mixture given from 50 parts of polyoctene and 50 parts of a liquid from the synthetic ester trimethylolpropane triheptanoate. Aging at elevated temperatures revealed that the resulting mixture had excellent antioxidant properties receives.

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Claims (10)

27337H - / - B 8326 claims 1. Liquid substances found in mineral oils, synthetic hydrocarbon lubricants and in Synthetic ester lubricants act as antioxidants, characterized in that they have the Contain reaction products of phenylnaphthylamine and mixed propylene trimers, the Reaction in the presence of a Friede1-Crafts catalyst was carried out. 2. Liquid substances according to claim 1, characterized in that the phenylnaphthylamine ct-phenylnaphthylamine is. 3. Liquid substances according to claim 1, characterized in that the phenylnaphthylamine ß-phenylnaphthylamine is. 4. Liquid substances according to one of the preceding claims, characterized in that the propylene trimers contain a variety of isomers. 5. Liquid substances according to one of the preceding claims, characterized in that the propylene trimers contain at least 30 isomers. 6. Liquid substances according to one of the preceding claims, characterized in that the reaction products contain a variety of isomers. 7. Liquid substances according to one of the preceding claims, characterized in that the Friedel-Crafts catalyst Aluminum chloride is. 70988B / 0723 B 8326 8. Liquid substances according to Claims 1 to 6, characterized / that the Friedel-Crafts catalyst Boron trifluoride is 9. Use of the liquid substances according to one of the preceding claims as antioxidants by adding the substances to liquid lubricants synthetic ester, in particular trimethylolpropane triheptanoate, or to liquid lubricants made from mineral oil or to liquid lubricants made from synthetic Hydrocarbon, especially polyoctene or polydecene, in an amount from 0.05 parts to 4 parts of the liquid substances per 100 parts of the liquid lubricant. 10. Use of the liquid substances according to claim 9 as antioxidants for a liquid lubricant, that from about 25 parts to 50 parts of polyoctene and from about 50 parts to 75 parts of trimethylolpropane triheptanoate consists, in an amount of 0.05 part to 4 parts of the liquid substances per 100 parts of the liquid lubricant. 70988R / 0723