WO2017045764A1

WO2017045764A1 - Biodegradable lubricant compositions having high compatibility with elastomers for use in marine applications, in particular in the area of stern tube lubrication

Info

Publication number: WO2017045764A1
Application number: PCT/EP2016/001568
Authority: WO
Inventors: Christof Schmitz; Patrick WITTMEYER; Petra Schwarz; Stefan Seemeyer; Thomas Kilthau; Maria FRACKOWIAK
Original assignee: Klüber Lubrication München Se & Co. Kg
Priority date: 2015-09-17
Filing date: 2016-09-16
Publication date: 2017-03-23
Also published as: DE102016011022A1

Abstract

The invention relates to the use of lubricant compositions based on estolides in marine applications, in inland water and in offshore systems, i.e. for the lubrication of bearings, propeller paddles, propeller shafts, machine components and systems, which come into contact with salt water in marine applications or with water and/or aqueous media in inland water applications. The lubricant compositions are biodegradable and have high compatibility with elastomers. The lubricant compositions are based on trimethylol complex esters or poly(iso)butene and estolides for use in marine applications, as well as in the area of stern tube lubrication.

Description

Biodegradable lubricant compositions with high elastomer compatibility for use in the marine sector, especially in the field of

Stern tube lubrication

description

The present invention relates to the use of

Lubricant compositions based on trimethylol complex esters or poly (iso) butene and marine estolides, in the area of inland waters and offshore installations, i. For lubrication of plain bearings, propeller stems, propeller shafts, machine components and systems that come into contact with salt water in the marine sector or with water or aqueous media in inland waters. The lubricant compositions are biodegradable and have high elastomer compatibility.

In marine applications, which are mostly below the waterline, there is a risk of contaminating the marine environment by leaking lubricants. Although attempts are made to seal the water side in these applications as well as possible, lubricant losses are commonplace. According to a source of the United States Environmental Protection Agency in 2011, shipbuilding varies from less than one liter of lubricant to as much as 20 liters per day per ship.

For example, in order to reduce the amounts of different lubricants on board a ship, lubrication of the stern tube has usually been done with the same lubricant as the main engine. In turn, this lubricant is often based on mineral oils and contains a high proportion of basic additives that have a strong toxic effect on the marine environment.

In recent years, the protection of the marine environment has become increasingly important, which is reflected in much tighter legislation. In the US, for example, so-called EAL s (Environmentally Appropriate Lubricants) are required, which have low aquatic toxicity and high biodegradability and, moreover, have no bioaccumulating effect.

But in all other applications contamination of the environment can not be excluded. Especially with exposed components, the lubricant can reach the environment by washing out.

The above-mentioned lubricant, a lubricating oil, is used in marine applications for sterntube lubrication. This is a bore through the hull through which the propeller shaft passes. There, the propeller shaft is supported by a propeller shaft bearing, the so-called stern tube bearing.

The primary task of the propeller shaft is the transmission of the drive movement through the hull to the screw. The bearing ensures low-friction movement and the seals for the sealing of the drive shaft, both to the engine room and the sea side. This seal is accomplished by a seal made of elastomeric material, such as e.g. FKM exists. Nevertheless, it can be expected both with the leakage of the lubricant into the marine environment, as well as with the penetration of the water into the stern tube.

In general, the above machines are lubricated with lubricating oils. These are usually based on mineral oils, synthetic hydrocarbons, silicone oils and various polyethers and polyglycols.

Since the above-mentioned machines and their components are lubricated mainly based on mineral oil and therefore not current environmental regulations There is a high demand for ecologically safer lubricants.

The common biodegradable lubricants on the market are mainly composed of the following base oils. i) Natural vegetable oils, consisting mainly of mono-, di- and triglycerides of fatty acids and a small proportion of glycerol and free fatty acids. These may contain saturated as well as unsaturated hydrocarbon chains. Disadvantages of natural vegetable oils are their poor low-temperature behavior and the low thermo-oxidative stability. ii) Synthetic esters, which are prepared mainly by acid-catalyzed reaction of carboxylic acids with alcohols. These starting materials can be obtained from biomaterials as well as from petroleum products. In contrast to the natural vegetable oils, synthetic ester oils are generally very temperature-stable. Your performance can be adapted to the respective requirements. iii) Polyglycols consisting of predominantly linear, but also partially branched polyethers, which are usually synthesized by ring-opening polymerization of ethylene oxides or propylene oxides. The higher the proportion of ethylene oxide, the more water the lubricant can absorb.

The above oils can be used pure or as a mixture. Low viscosity polyalphaolefins or polymeric systems can be used to adjust viscosity, among other things. The addition of certain additives may improve certain properties, such as, but not limited to, oxidative stability.

A major problem is the elastomer compatibility of biodegradable lubricants in the presence of water. The object of the present invention is therefore to provide a lubricant composition which may come into contact with sea water, water and / or aqueous media in the marine sector, in offshore installations and / or in the area of inland waters. This means that these lubricating compositions can be used to lubricate slide bearings, propeller rotors, propeller shafts, in machinery, machine components and equipment, which lubricant composition must be biodegradable and compatible with elastomeric materials such as FKM, NBR, HNBR, ACM / AEM and polyurethanes.

This object is achieved in that the lubricant composition, which is used in the marine sector, in the area of inland waters and offshore installations, contains as base oil Trimethylolpropankomplexester and / or poly (iso) butene and Estolid and certain additives.

The lubricant compositions of this invention have good biodegradability (e.g., biodegradability of Estolide ISO VG 100> 60% in 28 days according to OECD 301F). Estolides are ester compounds which are acid-catalyzed or enzymatically produced from fatty acids. In the acid-catalyzed production of estolides from unsaturated fatty acids, the acid function of the fatty acid attacks a double bond of an adjacent fatty acid molecule and thus forms an addition product. The addition product can in turn react with another fatty acid. This results in higher molecular ester compounds, so-called estolides. In the synthesis, oleic acid is preferably used. The terminal acid group of the estolide is usually esterified with an alcohol, preferably 2-ethyl-hexanol and then hydrogenated, the remaining double bonds. Other alcohols, such as e.g. Isoamyl alcohol or Guebert alcohols can also be used.

The inventively used estolides have viscosities up to 2500 mm ² / s at 40 ° C, preferred viscosities are in the range of 20 to 500 mm ² / s at 40 ° C, particularly preferred viscosities are in the range of 30 to 140 mm ² / s at According to the invention, a biodegradable and elastomer-compatible lubricant composition comprising (A) 0.5 to 50% by weight of a component selected from the group of one or more trimelthylol complex esters and / or partially hydrogenated and / or fully hydrogenated poly (iso) butene,

(B) 0.5 to 10% by weight of an additive package and

(C) Estolid compounds used to fill the composition up to 100% by weight for lubrication of plain bearings, propeller rotors, propeller shafts in machinery, machinery components and installations used in marine, inland waters, offshore installations with seawater, water and / or aqueous media come into contact.

In a preferred embodiment of the invention

A lubricant composition comprising (A) 5 to 50% by weight of a component selected from the group of one or more trimelthylol complex esters and / or partially hydrogenated and / or fully hydrogenated poly (iso) butene,

(B) 0.5 to 10% by weight of an additive package and

In a particularly preferred embodiment of the invention, component (A) used is a trimethylol complex ester in a range from 5 to 40% by weight. The lubricant composition of the invention is preferably used for stern tube lubrication.

Component (A) is selected from the group consisting of

Poly (iso) butenes, polymeric systems, such as non-hydrogenated, partially hydrogenated or fully hydrogenated polybutene and / or polyisobutene,

Trimethyloipropane complex esters, completely or partially esterified with saturated and / or unsaturated carboxylic acids and dicarboxylic acids in any desired mixture with a chain length of 6 to 36 carbon atoms, these may be linear or branched.

The trimethylolpropane complex esters whose kinematic viscosity is at least 400 mm ² / s at 40 ° C. are preferred, trimethyloipropane complex esters having a kinematic viscosity of at least 800 mm ² / s at 40 ° C. are particularly preferred.

Preferred are trimethylolpropane complex esters whose acid number is less than 1 mg KOH / g, particularly preferred are those whose acid number is less than 0.5 mg KOH / g.

Preference is given to using poly (iso) butenes having viscosities at 100 ° C. of at least 100 mm ² / s, particularly preferably using viscosities at 100 ° C. of 500 mm ² / s. Poly (iso) butenes (PIB) are polymers which have the following structure: ί f ^>'

4, - c- · - [,

PIB differs from polybutene (PB) in that PIB are branched and PB is linear and largely isotactic.

The lubricant composition according to the invention contains as component (B) an additive package which is selected from additives for improving the oxidative Stability, load carrying capacity, wear protection, friction reduction, UV stability, pour point, viscosity-temperature behavior, corrosion protection and additives to improve the foam behavior, as well as emulsifiers.

Examples of the additives mentioned are:

Antioxidants, e.g. linear and / or branched alkylated, arylated, aliphatic and aromatic amines, phenols and their derivatives, phosphites, sulfur-containing compounds and mixtures of these components,

Anticorrosion additives (metal and non-ferrous metal deactivators and ion complexing agents): e.g. Sulfonic acids and salts of sulfonic acids, overbased sulfonates, succinic acids and salts of succinic acids, linear salicylic acids and their salts, benzotriazoles and tolyltriazoles and theirs

Derivatives, and mixtures thereof,

Anti-wear additives, extreme pressure additives and friction modifiers and components, such as amine phosphates, phosphates, thiophosphates, alkylated polysulfides, amine compounds, copolymers of esters and polyalphaolefins, sulfurized esters, and mixtures of these components,

Pour point and viscosity improvers, such as linear and / or branched alkylated, acrylated and aliphatic polymers and copolymers, as well as polymerized fatty acid esters,

Emulsifiers and

Defoamers.

Furthermore, fluorescent dyes can be added to the lubricant composition, thus enhancing the existing fluorescent property of the estolides, so that the lubricant composition can also be used to detect leaks. The lubricant compositions of the invention have kinematic viscosities at 40 ° C of 30 mm ² / s to 220 mm ² / s, particularly preferred viscosities of 68 mm ² / s to 150 mm ² / s.

The lubricant compositions according to the invention will now be explained in more detail below with reference to the examples. The viscosity of all the examples listed below is in the range of ISO VG 100. Examples

Production process for an oil formulation:

The Estolid is presented in the boiler. The viscosity-providing component and / or one or more further base oils are added and a clear solution is produced with stirring and optionally heating to a defined temperature. Solid additives are added at a temperature above their melting point and stirred in until they are dissolved. The contents of the kettle are then cooled to a maximum of 60 ° C. and the liquid additives are added. After another hour of stirring, the oil can be filled.

example 1

Example 2

Comparative Example 1

Comparative Example 2

The example formulations were tested for elastomer compatibility. To test the elastomer compatibility, the elastomeric material was exposed to the action of the respective lubricating oils, which had been admixed with 5% by weight of water, at one at a temperature of 80 ° C. and with stirring for 336 hours. To determine the elastomer compatibility, a standard marine elastomer was used.

The elastomer was then subjected to the following tests in accordance with the applicable standards:

- Volume change DIN ISO 1817

- Change of Shore A hardness DIN ISO 7619-1 Volume change:

The change in the volume of the test specimens gives rise to the migration of the test liquid into the interior of the material or the dissolution or possibly also dissolution of the material.

Shore A hardness:

Hardness is generally referred to as the mechanical resistance of the material when a harder specimen penetrates.

Table 1

Results of static elastomer incorporation

As Table 1 shows, the lubricant according to the invention meets the requirements both in terms of volume change as well as with respect to the change of the Shore A. Hardness, whereas the lubricant compositions of the comparative examples exceed the maximum tolerated limits, eg in the range of volume change.

Experience has shown that it is concluded from the oil formulations that formulations with a higher viscosity also have an improved elastomer behavior.

Claims

claims

Use of a biodegradable and elastomer compatible lubricant composition consisting of

(A) 0.5 to 50 wt .-% of a component selected from the group of one or more Trimelthylolkomplexester and / or partially hydrogenated and / or fully hydrogenated poly (iso) butene,

(B) 0.5 to 10% by weight of an additive package and

(C) Estolid compounds with which the composition is made up to 100% by weight

for the lubrication of slide bearings, propeller rudders, propeller shafts in machines, machine components and installations which come into contact with seawater, water and / or aqueous media in the marine sector, in the area of inland waters, in offshore installations.

(A) 5 to 50 wt .-% of a component selected from the group of one or more Trimelthylolkomplexester and / or partially hydrogenated and / or fully hydrogenated poly (iso) butene,

(B) 0.5 to 10% by weight of an additive package and (C) Estolid compounds with which the composition is made up to 100% by weight

(A) 5 to 40% by weight of a component selected from the group of one or more trimelthylol complex esters and / or partially hydrogenated and / or fully hydrogenated poly (iso) butene,

(B) 0.5 to 10% by weight of an additive package and

(C) Estolid compounds with which the composition is made up to 100% by weight

Use according to any one of claims 1 to 3, wherein the additive package is selected from the group consisting of antioxidants, anti-corrosion additives, metal deactivators and / or ion complexing agents, anti-wear additives, extreme pressure additives and friction modifiers, pour point and viscosity improvers, UV stabilizers, Emulsifiers, defoamers, used individually or in combination.

Use of the lubricant composition according to any one of claims 1 to 4, for stern tube lubrication.