CZ20022810A3 - Lubricant containing carbonic acid ester and intended for metal forming - Google Patents

Abstract

The invention relates to the use of carbon dioxide esters of general formula (I) in lubricants for forming metals under the effects of sliding friction. In said formula: R and R' can be identical or different and each represent a linear or branched alkyl group, a cycloalkyl group or an alkyl-cycloalkyl group, each with between 5 and 30 C atoms. The invention also relates to lubricants containing carbon dioxide esters of general formula (I) and one or more components selected from a) mono and/or diesters of mono or oligophosphoric acids with between 1 and 6 P atoms having linear or branched fatty alcohols with between 12 and 22 C atoms, or their non-esterified starting products b) triglycerides of fatty acids with between 12 and 22 C atoms and c) methyl esters of fatty acids with between 12 and 22 C atoms. The lubricants are preferably devoid of mineral oil.

Description

Technical field

The invention relates to the field of cold forming of metals, such as drawing of tubes, wires and profiles, cold forming and cold forming of components, for example deep drawing or cold pressing. Common to these processes is that the forming process is associated with a strong sliding friction between the working tool and the workpiece, whereby initial or adhesive friction can be overcome particularly at the beginning of the forming process. During the forming process, a “Rattern” or “Stick-Slip-Effect” can occur, with the type of friction changing between sliding and adhesive friction at short intervals. Said forming processes thus differ from cold rolling of metal strips, in which mainly friction between the metal substrate and the rollers occurs. In order to avoid sliding and adhesive friction between the tool and the workpiece, a lubricant is used. The present invention relates to such a lubricant.

BACKGROUND OF THE INVENTION

Conventional lubricants for these uses are based on mineral oil or similar hydrocarbons such as petroleum distillates. Such substances are normally biodegradable by industrial or municipal treatment stations and can therefore be difficult and costly to remove.

It is known from EP-A-393 749 to use selected carbonic acid esters for the rolling process, which are referred to as organic carbonates. EP-A-89-709

- 2 ”describes a lubricant containing this carbonic acid ester for lubrication processes without metal forming. Examples are lubricants for internal combustion engines or industrial lubrication, for example in the form of gear oils or compressor oils.

Thus, in the lubrication processes of EP-A-89 709, there is no metal forming and the aim is to minimize the sliding friction between the metal parts as much as possible. The rolling forming processes of EP-A-398 749 are carried out by rolling friction, the sliding friction between the rollers and the metal substrate being also kept to a minimum.

In contrast, the present invention relates to a metal forming process by cold forming, with a strong sliding friction between the working tool and the work item. Since the frictional forces involved are considerably greater than those of EP-A-89 709 and EP-A-393 749, it cannot be assumed that a lubricant suitable for these processes can also be used in cold-forming metals. sliding friction.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide cold forming lubricants that are less expensive to remove and have better lubricating effects than conventional hydrocarbon-based lubricants.

The invention refers to the surprising finding that the carbonic acid esters described in EP-A-89 709 and EP-A-393 749 can also be used for the purpose of solving the intended task. This is particularly true when supplemented with components that serve as a substitute for hydrocarbons such as mineral oil or petroleum distillates.

Thus, in a first aspect, the invention relates to the use of carbonic acid esters of formula (I),

RO-C-OR '

II 0) o

wherein R and R 'may be the same or different and represent a linear or branched alkyl, cycloalkyl or C 5 -C 30 alkyl-cycloalkyl radical in sliding friction metal forming lubricants.

These carbonic esters can be produced by re-esterifying the carbonic esters of lower alcohols (e.g., C 1 -C 3 alcohols) with non-volatile C 5 -C 30 alcohols. Further information for the preparation of these carbonic acid esters can be obtained from both of the above documents.

The alkyl groups R and R 'of the alcohol components of the carbonic esters may correspond to primary, secondary or tertiary alcohols. Preferably, the radicals R and R 'are linear or branched alkyl groups having 6 to 30, in particular 10 to 20, carbon atoms.

Preferably, esters of the formula (I) which contain no mineral oil are used in the lubricants within the meaning of the present invention. For said use, preferably a lubricant is used which, in addition to the carbonic acid ester of formula (i), contains one or more components selected from:

(a) mono- and / or diesters of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched fatty alcohols having 12 to 22 carbon atoms or from their non-esterified starting products,

(b) triglycerides of C 12 -C 22 fatty acids; and

i: ··.

(C) methyl esters of C 12 -C 22 fatty acids.

Furthermore, lubricants for said uses may additionally contain one or more components selected from:

d) terpenes,

(e) flow - reducing means; and

(f) alkylamines of formulas (IIa) and (IIb);

R-NH ₂ (Ha)

R - [NH- (CH ₂ ) _n -] _m NH ₂ (IIb) wherein R represents a linear or branched, saturated or mono- or polyunsaturated alkyl group having 8 to 22 carbon atoms, n represents an integer from 1 to 4 and m represents an integer number 1 to 4.

With a suitable choice of components, lubricants containing carbonic acid esters of formula (I) can be used not only for forming metals under sliding friction, but generally for lubrication purposes. Accordingly, in a further aspect, the invention relates to a lubricant comprising a carbonic acid ester of formula (I),

RO - C - OR ^'11 (O

Wherein R and R 'may be the same or different and represent a linear or branched alkyl radical, a cycloalkyl radical or an alkyl-cycloalkyl radical of 5 to 30 carbon atoms, and one or more components selected from:

- 5 (a) mono- and / or diesters of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched fatty alcohols having 12 to 22 carbon atoms or from their non-esterified starting products,

(b) triglycerides of C 12 -C 22 fatty acids; and

c) methyl esters of C 12 -C 22 fatty acids.

It is also preferred that the new lubricant additionally comprises one or more components selected from:

d) terpenes,

(e) flow - reducing means; and

(f) alkylamines of formulas (IIa) and (IIb);

R - NH ₂ (ila)

R - [NH- (CH ₂ ) n -] m NH ₂ (IIb) wherein R is a linear or branched, saturated or mono- or polyunsaturated alkyl group of 8 to 22 carbon atoms, n is an integer of 1 to 4 and m is an integer number 1 to 4.

These compositions are also mineral oil-free within the meaning of the present invention.

In particular, the lubricant according to the invention is characterized in that it contains from 8 to 15 wt. of a carbonic acid ester of formula (I) and one or more of the following:

a) 8 to 42 wt. mono- and / or diesters of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched fatty alcohols having 12 to 22 carbon atoms or non-esterified starting products thereof, »

I * # ^w- »• * i •. * · ·

6 · ♦ · · · · ·. i · · · · · · ·

b) 20 to 38 wt. C12-22 fatty acid triglyceride

c) 3 to 25 wt.%, preferably 5 to 25 wt. methyl ester of C 12 -C 22 fatty acids, and it is preferred that the lubricant additionally contains one or more of the following:

d) 5 to 25 wt.%, preferably 5 to 10 wt. terpenes,

e) 0.1 to 0.5 wt. means for lowering the pour point,

f) 3 to 8 wt. % of the alkylamine of formulas (IIa) and (IIb), wherein the proportions are selected such that their sum is not more than 100% by weight. and wherein the remainder to 100 wt. consists of other active and / or excipients.

In particular, component a) can assume the role of so-called high pressure additives (EP additives). In conventional lubricants, oraganic compounds containing chlorine or sulfur or heavy metal compounds such as tin, molybdenum or tungsten compounds are often used for this function. As a result of the use of component a), additives which make it difficult to remove the used lubricant can be dispensed with. Therefore, a preferred embodiment of the lubricant according to the invention is that it is free of heavy metals and chlorine and sulfur containing compounds.

Subsequently, components a) to f) will be described in more detail.

DETAILED DESCRIPTION OF THE INVENTION

Component a) is a mono- and / or diester of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched C 12 -C 22 fatty alcohols or non-esterified starting products thereof. In practice, this component is incorporated into a lubricant where the mono- or oligophosphoric acid having from 1 to 6 phosphorus atoms or its anhydrides is mixed with fatty alcohols. In this case, at least in part, the formation of an ester between phosphoric acids and / or phosphoric acids occurs, in part, already during the production of the lubricant, but also partly at elevated operating temperatures. their anhydrides and fatty alcohols. It is therefore not desirable to synthesize esters in a separate step prior to the manufacture of the lubricant of the invention. On the basis of the thermodynamics and kinetics of ester formation, it is expected that the lubricant will contain a mixture of mono- and diesters and possibly unesterified phosphoric acid or a non-esterified phosphoric acid. alcohols. As phosphoric acid, for example, tetrafosphoric acid having 4 phosphorus atoms can be used. Their anhydrides are also suitable. For example, the alcohol component may be a technical blend of fatty alcohols that is available by cleavage and reduction of natural oils and fats. These reaction products of natural fats and oils usually contain a mixture of fatty alcohols with different carbon chain lengths. For example, C až až 20 20 složky složky složky k složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky složky 14 složky 14 složky složky 14 složky složky složky složky 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 složky složky 14 složky složky složky složky složky složky složky složky složky 14 14 14 14 14 14 14 16 16 16 16 16 16. For example, the components of the useful lubricant may consist of a) 60 to 80% monoester, 10 to 20% diesters and 10 to 20% free phosphoric acid. If an anhydride is used instead of phosphoric acid, the free acid content of the useful lubricant is reduced in favor of the phosphoric acid ester. Thus, products can be obtained in which component a) consists, for example, of 60 to 70% of diesters and 30 to 40% of a monoester and almost no free acid content.

Component (b) is one of the components that allows the renunciation of mineral oil. These may be natural oils or fats or their conversion products, provided they are either liquid at the temperature of use or dissolve in the remaining liquid components. Liquids are preferred as component b) at room temperature. That is, the triglyceride fatty acid components are preferably at least partially unsaturated. For example, triglycerides having a high proportion of oleic acid are suitable. As is common with natural oils and fats and their downstream products, there are triglycerides as mixtures of molecules containing various fatty acid components.

Component c) is methyl esters of C 12 -C 22 fatty acids. They are available by re-esterification of natural fats and oils with methanol. Accordingly, there are also, as a rule, products which are mixtures of a methyl ester with fatty acids of different chain lengths. These fatty acid methyl esters are also known as 'biodiesel' because they are alternatively suitable for use as diesel fuel for internal combustion engines. Together with or instead of component b), the methyl esters serve as a mineral oil substitute for the lubricants of the invention.

Component (d) may be a mixture of terpenes, optionally with other natural substances. These terpene mixtures are technically available by distillation of plant seeds. In these plant seed distillation products, there is usually a very complex mixture of individual molecules, in addition to terpenes, there are also linear unsaturated hydrocarbons, alcohols and aldehydes. Terpene distillates such as Globeoil (R) - products from DE.FI.LU (Italy) are commercially available as lubricant components. These terpenes can also be regarded as mineral oils in the formulations of the invention.

Component e) is a flow point lowering agent that can be added to the lubricants of the invention when its pour point or flow temperature is to be reduced. freezing point. This depends on the choice of the remaining components as to whether these means will be necessary. Suitable products are known in the art of preparing lubricating oils. For example, ethylenediaminetetraacetate tetraamide or derivatives thereof may be used.

• ·

- 9 The alkylamines of component (f) may in turn be regarded as a mineral oil substitute. For example, these mono- or oligoamines are known as belt lubricant components in the beverage industry. Oligoamines of formula (IIb) can be used as component f). However, for economic reasons, the monoamines of formula (IIa) are preferred. These alkylamines are generally derived from fatty alcohols which are available by cleavage and reaction of natural fats and oils. Therefore, these amines often exist in the form of molecular mixtures with different R radicals. The R radicals can be saturated or unsaturated one or more times. Particularly suitable amines are those wherein the radical R contains 12 to 20 carbon atoms. An example of this is the oleyl residue.

The products according to the invention can be produced free of mineral oils and at the same time free of heavy metals and compounds containing chlorine and sulfur. The lubricating components are based at least largely on renewable raw materials, such as vegetable or animal oils and fats. Their removal is simplified because the substances are degradable in industrial or municipal cleaning stations. In addition to these environmental benefits, the lubricants of the invention also have technical advantages. Compared to conventional oil-based products, their viscosity is up to 25% lower, making application easier. Compared to mineral oil-based products, the drawing speed can be increased, even achieving a lower surface roughness than with mineral oil-based products. When drawing the tubes, a 40 to 50% reduction in the drawing step is achieved.

Claims (4)

Patent claims Use of a composition comprising (i) carbonic acid ester of general formula (I); RO-C-OR 'il (!) Wherein R and R 'may be the same or different and represent a linear or branched alkyl, cycloalkyl or C 5 -C 30 alkylcycloalkyl radical; ii) one or more components selected from: (a) mono- and / or diesters of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched C 12 -C 22 fatty alcohols or non-esterified starting products thereof, (b) C 12 -C 22 triglycerides; and (c) methyl esters of C 12 -C 22 fatty acids; and (iii) one or more components selected from: (d) terpenes; and (f) alkylamines of formulas (IIa) and (IIb); R - NH ₂ (IIa) - 11 R - [NH- (CH ₂ ) n -] m NH ₂ (IIb) wherein R represents a linear or branched, saturated or mono- or polyunsaturated alkyl group of 8 to 22 carbon atoms, n represents an integer of 1 to 4 am means an integer of 1 to 4 in lubricating agents for forming metal by sliding friction, the lubricants containing no mineral oil. 2. A lubricant comprising (i) carbonic acid ester of general formula (I); RO-C-OR ' II o (i) wherein R a R 'may be the same or different and represent a linear or branched alkyl radical, a cycloalkyl radical or an alkylcycloalkyl radical of 5 to 30 carbon atoms; ii) one or more components selected from: (a) mono- and / or diesters of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched C 12 -C 22 fatty alcohols or non-esterified starting products thereof, (b) triglycerides of C 12 -C 22 fatty acids; and (c) C12-C22 fatty acid methyl esters; and - 12 (iii) one or more ingredients selected from: (d) terpenes; and (f) alkylamines of formulas (IIa) and (IIb); R-NH ₂ (IIa) R '' - [NH- (CH ₂ ) _n -] mNH ₂ (IIb) wherein R is a linear or branched, saturated or mono- or polyunsaturated C 8 -C 22 alkyl group, n is an integer from 1 to 4 am an integer of 1 to 4, wherein the lubricant is mineral oil free. Lubricant according to claim 2, characterized in that it contains, based on the total amount of lubricant (i) 8 to 15% by weight of a carbonic acid ester of formula (I); (ii) one or more components selected from: (a) 2 to 42% by weight of mono- and / or diester of mono- or oligophosphoric acid having 1 to 6 phosphorus atoms with linear or branched C 12 -C 22 fatty alcohols or their non-esterified starting products, - 13 (b) 20 to 38% by weight of C 12 -C 22 triglyceride, (c) 3 to 25% by weight of a C 12 -C 22 fatty acid methyl ester; and (iii) one or more components selected from: (d) 5 to 25% by weight of terpenes; f) 3 to 8% by weight of alkylamines of formulas (IIa) and (Hb), wherein the proportions are selected such that their sum is not more than 100% by weight and the remainder to 100% by weight consists of further active and / or excipients. Lubricant according to one or both of Claims 2 and 3, characterized in that it is free of heavy metals and compounds containing chlorine and sulfur.