DE1096529B - Lubricant for the non-cutting deformation of metals - Google Patents

Description

The invention relates to the use of certain alkylation residues as lubricants for the non-cutting deformation of metals.

During the non-cutting deformation of metals, such as cold rolling or pressing, lubricants are used are used, which must be subject to special requirements: On the one hand, they should have a high pressure absorption capacity have to allow a high degree of deformation per operation; on the other hand they should be completely and during the heat treatment, which in many cases follows cold deformation especially evaporate without leaving any residue.

In general, mineral oils, with or without additives, are used for this purpose. To get the required To achieve pressure absorption, mineral oils of higher viscosity are used. The boiling range of such However, mineral oils are then above the temperatures that are in many cases during heat treatment be applied so that they do not evaporate completely; at higher heat treatment temperatures in turn, they often leave resinous to carbonaceous residues. The well-known lubricating oil additives that affect the pressure absorption capacity also tend to provide evaporation residue.

It is known that cyclic organic compounds have a lower boiling range for the same viscosity have as straight chain. Accordingly, the preferred lubricant for non-cutting cold working is naphthenic Mineral oils versus the paraffinic ones. However, the above requirements can also be met thus not meet to a satisfactory degree.

In the French patent specification 980 058 lubricants are described which consist of a minor proportion of a fatty acid with a chain length of C ₈ to C ₁₆ and a major proportion of a synthetic organic solvent of, for example, an alkyl aromatic structure. As a result of the fatty acid content, however, they also have the disadvantage that under certain circumstances they leave behind evaporation residues, especially when the higher molecular weight fatty acids from the range mentioned are used to achieve a high pressure absorption capacity.

It has now been found that in the monoalkylation of aromatic hydrocarbons to Introduction of an alkyl group with at least 8 carbon atoms resulting alkylation residues or the products obtained therefrom by distillation in particular as a lubricant for non-cutting Deformation of metals are suitable. In particular, falls in the condensation of benzene with propylene tetramer in addition to the monoalkylbenzene, which is the main product, a higher-boiling portion of which is good suitable as a lubricant for this purpose.

These alkyl aromatic synthetic lubricants

Lubricant for the chipless
Deformation of metals

Applicant:

Shell International Research
Maatschappij NV, The Hague

Representative: Dr. K. Schwarzhans

and Dipl.-Chem. Dr. phil. E. Jung, patent attorneys,

Munich 19, Romanplatz 9

Dr. Hellmuth Grosse-Oetringhaus, Hamburg-Harburg, and Dr. Rolf Konau, Hamburg-Fuhlsbüttel,

have been named as inventors

meet the above requirements better than the previously used lubricants for non-cutting deformation: They evaporate at lower temperatures than mineral oils of the same viscosity, and they evaporate, without leaving any residue. Another advantage is that they are as a result of their compared to mineral oils very low sulfur content do not attack the metal surface even at elevated temperatures. A Viscosity range of over 10 cSt and in particular over 20 cSt at 50 ° C has been shown to be useful; a For example, alkylbenzene lubricating oil of this last viscosity can be beneficial in cold rolling aluminum to be used. However, a lower viscosity rolling oil is often required; for these purposes the viscosity can be adjusted by mixing with up to 50 percent by weight, based on the finished lubricant

4.0 medium, lower viscous petroleum products, such as Kerosene, without impairing the favorable properties of the synthetic lubricant will. Such mixtures are more suitable as rolling oils than pure alkyl aromatic hydrocarbons the same viscosity.

It is known per se, relatively high molecular weight oily condensation products in the form of distillation residues from the implementation of certain gasoline, medium oil, diesel oil or lubricating oil fractions resulting from thermal decomposition of solid, bituminous substances, to be obtained with acidic condensing agents. Such fractions include cyclical ones Compounds and aliphatic, unsaturated and / or tertiary bonded carbon atoms containing sub-

009 697/464

I 096 529

punch before, the mixtures of singly and multiply alkylated aromatics resp. Form naphthenes, the alkyl substituents being short and long chain. Such products should be under Suitable as pour point depressants, as intermediates for plasticizers and as paint raw materials. In contrast to this known prior art, the lubricants according to the invention are used products used for non-cutting metal deformation to remove distillation residues, which in the Monoalkylation of pure aromatic hydrocarbons incurred, the introduced alkyl substituents contain at least 8 carbon atoms.

Example I.

In the production of alkylbenzenes from benzene and straight-chain α-olefins with a chain length of C ₈ to C ₁₄ , a higher-boiling product is obtained in addition to the monoalkylbenzene, from which a lubricant with the following data can be obtained by distillation:

Density 20 ° C 0.870

Refractive index n ²⁰ ° ^c 1.4889

Flash point at 185 ° C

Viscosity 50 ° C 23.8 cSt

Pour point -40 ° C

Sulfur content 0.07%

Ash content 0.00%

This lubricant is compared to the following common lubricants as follows:

A. Mineral oil lubricants

Density 20 ° C 0.925

Flash point at 180 ° C

Viscosity 50 ° C 18 cSt

B. Lubricant according to French patent specification 980 058

1. Dodecylbenzene 95%

C ₁₂ fatty acid 5%

2. Dodecylbenzene 95%

C ₁₆ fatty acid 5%

For the experiment, the lubricants are spread on bare iron sheet strips and exposed to an elevated temperature of 350 ° C. at the beginning to 400 ° C. at the end of the heating period for 1 hour. After the heat treatment, the metal surface in the case of the lubricant according to the invention is oil-free and bare, while the mineral oil A leaves a carbonaceous residue which coats the entire metal surface. The lubricant B _{1 also} leaves residues, but in the form of stains on the rest of the bare surface; lubricant B ₂ also stains, but to a much greater extent than B ₁ .

Example II

In the condensation of benzene and tetramerpropylene, in addition to dodecylbenzene, a higher-boiling product is obtained which mainly contains dialkylbenzenes with chain lengths of C ₁₂ and monoalkylbenzenes with chain lengths of C ₂₀ to C ₂₄ . For this product

a lubricant with the following data can be obtained by distillation:

Density 20 ° C, 0.875

Refractive index n ^z0 ° ^c 1.4896

Flash point at 173 ° C

Viscosity 50 ° C 20.3 cSt

Pour point -42 ° C

Sulfur content 0.02%

Ash content 0.00%

This lubricant gives an equally good result under the same test conditions as in Example I.

Example TII

68 parts by volume of the lubricant according to the invention from Example I are mixed with 32 parts by volume of a naphthenic Mineral oil product from the boiling range 180 to 220 ° C. The product is as low viscosity Lubricant well suited for cold rolling aluminum. It has the following data:

Density 20 ° C 0.868

Refractive index n * °° ^c -. 1.4823

Flash point at 81 ° C

Viscosity 20 ° C 12.5 cSt

Pour point '. -65 ° C

Sulfur content 0.10%

Ash content 0.00%

In an aluminum cold rolling test, this lubricant is mixed with dodecylbenzene, which is exactly the same Viscosity, compared. With the lubricant of the present invention, there was a better rolling effect achieved than with the monoalkylbenzene.

Claims (4)

Patent claims: 1. Use of in the monoalkylation of aromatic hydrocarbons for introduction an alkyl group with at least 8 carbon atoms resulting alkylation residues or of the products obtained therefrom by distillation as a lubricant or lubricant base for the non-cutting deformation of metals. 2. Use of Alkyh'erungsrückstands according to claim 1, characterized in that the same Residues from the alkylation of benzene with propylene tetramer. 3. Use of alkylation residues according to claim 1 and 2, characterized in that the same a viscosity of at least 10 cSt at 50 ° C, e.g. B. 20 cSt at 50 ° C. 4. Use of alkylation residues according to claim 3, characterized in that the Lubricant a mixture of an alkylation residue with a viscosity of at least 20 cSt 50 ° C with less than 50 percent by weight, based on the total mixture, of a mineral oil fraction low viscosity. Considered publications:
German Patent No. 812 311.