U.S. patent application number 14/254026 was filed with the patent office on 2016-09-15 for novel sulphur-bridged comppounds, use thereof and process for production thereof.
The applicant listed for this patent is Rhein Chemie Rheinau GmbH. Invention is credited to Sandra HORSTMANN, Michael KOENIG, Markus KUILDER, David LAREM, Thomas ROSSRUCKER.
Application Number | 20160264903 14/254026 |
Document ID | / |
Family ID | 48182770 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160264903 |
Kind Code |
A2 |
LAREM; David ; et
al. |
September 15, 2016 |
NOVEL SULPHUR-BRIDGED COMPPOUNDS, USE THEREOF AND PROCESS FOR
PRODUCTION THEREOF
Abstract
The present invention relates to novel sulphur-bridged
compounds, in which within the molecule there is at least one fatty
acid bonded by way of at least one sulphur bridge to at least one
polyalkylene glycol ester, the reaction product of a fatty acid
with a polyalkylene glycol, and these have from 8 to 29% by weight
sulphur content, to use of these as sulphur carrier and lubricant
additive and to production of the said compounds.
Inventors: |
LAREM; David;
(Eppertshausen, DE) ; HORSTMANN; Sandra;
(Mannheim, DE) ; ROSSRUCKER; Thomas; (Oestringen,
DE) ; KUILDER; Markus; (Oftersheim, DE) ;
KOENIG; Michael; (Mannheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rhein Chemie Rheinau GmbH |
Mannheim |
|
DE |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140323373 A1 |
October 30, 2014 |
|
|
Family ID: |
48182770 |
Appl. No.: |
14/254026 |
Filed: |
April 16, 2014 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 135/06 20130101;
C07C 323/52 20130101; C10M 135/26 20130101; C10M 2219/024 20130101;
C10N 2070/00 20130101; C10M 2219/085 20130101 |
International
Class: |
C10M 135/06 20060101
C10M135/06 |
Claims
1. Sulphur-bridged compounds, characterized in that within the
molecule there is at least one fatty acid bonded by way of at least
one sulphur bridge to at least one polyalkylene glycol ester, the
reaction product of at least one fatty acid with a polyalkylene
glycol, and these have from 8 to 29% by weight sulphur content.
2. Sulphur-bridged compounds according to claim 1, characterized in
that the polyalkylene glycol ester is polyethylene glycol ester,
polypropylene glycol ester, polybutylene glycol ester and/or
polyalkylene glycol esters in which the ethylene oxide units,
propylene oxide units and/or butylene oxide units are in random
and/or blockwise arrangement, preferably being polyethylene glycol
ester.
3. Sulphur-bridged compounds according to claim 1 or 2,
characterized in that they comply with the following formulae:
##STR00005## where a, b, c, d, e, f, g, h, p, q, r, s, t, u, v and
w correspond mutually independently to values of from 3 to 29,
preferably from 5 to 12 and n, k, j and y correspond mutually
independently to values of from 2 to 10, preferably from 4 to 8,
m=from 4 to 10, preferably from 8 to 16, x=from 1 to 10, preferably
from 2 to 4.
4. Mixtures comprising at least one of the sulphur-bridged
compounds according to any of claims 1 to 3, and additionally
further lubricant additives and/or carrier liquids.
5. Process for the production of sulphur-bridged compounds
according to any of claims 1 to 4, characterized in that the
unsaturated fatty acid, preferably the monocarboxylic acid, is
first reacted with sulphur and/or hydrogen sulphide to give the
sulphur-bridged fatty acid and then this sulphur-bridged fatty acid
is reacted with polyalkylene glycol in such a way that at least one
carboxylic acid unit of the fatty acid is present within the
sulphur-bridged compounds.
6. Process according to any of claims 1 to 4, characterized in that
a molar excess of unsaturated fatty acid, preferably the
unsaturated monocarboxylic acid, is first reacted with polyalkylene
glycol to give the intermediate product composed of unsaturated
polyalkylene glycol ester and unsaturated fatty acid, and then this
intermediate product is reacted with sulphur and/or hydrogen
sulphide in such a way that at least one carboxylic acid unit of
the fatty acid is present within the sulphur-bridged compounds.
7. Process according to any of claims 1 to 4, characterized in that
the unsaturated fatty acid, preferably unsaturated monocarboxylic
acid, is first mixed with at least one unsaturated fatty acid
polyalkylene glycol ester and then this mixture is reacted with
sulphur and/or hydrogen sulphide in such a way that at least one
carboxylic acid unit of the fatty acid is present within the
sulphur-bridged compounds of the invention.
8. Process according to any of claims 5 to 7, characterized in that
preferred unsaturated fatty acids used are unsaturated
monocarboxylic acids having a carbon-chain length of from 6 to 32 C
atoms, and/or mixtures of unsaturated fatty acids, preferably
unsaturated monocarboxylic acids, where these can comprise
saturated fatty acids as ancillary constituent.
9. Process according to any of claims 5 to 8, characterized in that
the sulphur is added in elemental form and/or as hydrogen
sulphide.
10. Process according to any of claims 5 to 9, characterized in
that polyalkylene glycol used comprises bifunctional polyethylene
glycol.
11. Use of the sulphur-bridged compounds according to any of claims
1 to 4 as sulphur carrier and/or lubricant additive.
Description
[0001] The present invention relates to novel sulphur-bridged
compounds, in which within the molecule there is at least one fatty
acid bonded by way of at least one sulphur bridge to at least one
polyalkylene glycol ester, the reaction product of a fatty acid
with a polyalkylene glycol, and these have from 8 to 29% by weight
sulphur content, to use of these as sulphur carrier and lubricant
additive and to production of the said compounds.
[0002] In Lubricant Additives, 2003, pp. 259 and 260 it is said
that sulphur carriers are of a class of organic compounds in which
the oxidation state of the sulphur is 0 or -1 and the sulphur atom
is bonded either to a hydrocarbon or to a sulphur atom. It is
moreover explained that sulphur carriers have no other heteroatoms
except for oxygen. The sulphur carriers are produced by adding
sulphur to any of the types of unsaturated compounds which comprise
double bonds.
[0003] Sulphur carriers are mainly used as additive in lubricants.
According to the customary classification of lubricant additives,
sulphur carriers are classified with the high-pressure additives
(=EP Additive) group, on the basis of their superior effectiveness.
Sulphur carriers primarily prevent the fusion of two metallic
materials in frictional contact with one another, and specifically
under high loading and at high temperature. In Lubricants and
Lubrication, 2001, p. 107, it is said that the sulphur present
reacts with the metal surface, the temperatures at which this
reaction takes place generally being above 600.degree. C. The
low-friction layers resulting from the reaction are continuously
sheared away by a type of controlled wear process, and this
prevents fusion of the metal surfaces.
[0004] Sulphur carriers also reduce friction between two metallic
materials in frictional contact with one another, this effect being
mainly important under low loading and at low temperature. The
lubricant power of the sulphur carrier is a decisive factor in
friction reduction. In Lubricant Additives, 2003, p. 277 it is said
that the lubricant power of sulphur carriers generally rises with
increasing polarity.
[0005] Sulphur carriers composed of sulphur-bridged triglycerides
and/or fatty acid alkyl esters are produced from unsaturated
triglycerides and/or unsaturated fatty acid alkyl esters which are
then sulphur-bridged. Sulphur-bridged triglycerides and/or fatty
acid alkyl esters have the disadvantage of being immiscible with
water. When they are used in water-miscible lubricants it is
therefore necessary to add emulsifiers.
[0006] Sulphur carriers composed of sulphur-bridged fatty acids are
produced from unsaturated fatty acids which are sulphur-bridged.
The sulphur-bridged fatty acids are primarily used as additive for
water-miscible lubricants. In the production of water-miscible
lubricants, the sulphur-bridged fatty acids are normally
neutralized to give soaps, because the standard procedure adds
bases, for example triethanolamine or aqueous potassium hydroxide
solution, in order to establish an alkaline pH. The resultant
sulphur-bridged soaps are water-miscible and require no addition of
emulsifier, but instead can themselves act as emulsifier. They are
moreover strongly polar and have high lubricant power on metallic
materials. However, sulphur-bridged soaps have the disadvantage
that in hard water they can produce soap scum deposit, as by way of
example described in Lubricant Additives, 2003, p. 281. Various
approaches to a solution, for example adapting the lubricant
formulation to be appropriate to a prescribed water-hardness range
or the use of complexing agents, have hitherto been found to
provide only a partial solution. Satisfactory use of
sulphur-bridged fatty acids as additive for water-miscible
lubricants is generally possible only at high cost. This greatly
restricts their use.
[0007] In U.S. Pat. No. 4,172,800 and U.S. Pat .No. 3,822,299,
unsaturated fatty acids are first ethoxylated and then reacted with
sulphur to give sulphur-bridged fatty acid polyalkylene glycol
esters. The products described have no carboxylic acid unit. These
products cannot be used cost-effectively, because of low sulphur
content of less than 8% by weight, and/or are not fully
water-miscible. In Example 2 of U.S. Pat. No. 3,822,299, a
comparatively high sulphur content of 10.9% by weight is achieved.
Calculation of the HLB value according to W. C. Griffin gives an
HLB value of 7.5. Accordingly, when the product from Example 2 has
been diluted in water it forms a semi-stable emulsion, and it is
therefore not fully water-miscible.
[0008] All of the sulphur carriers known hitherto require addition
of emulsifiers for full miscibility in water and/or have low
polarity and/or tend to form soap scum deposit in hard water and/or
have low sulphur content. For the purposes of the invention, hard
water means a hardness level, expressed in German degrees, of at
least 8,4.degree. dH. This corresponds to the "moderate" and "hard"
hardness ranges according to the German "Wasch- and
Reinigungsmittelgesetz [Washing and Cleansing Agents Act]",
2007.
[0009] The object of the present invention therefore consisted in
providing sulphur-bridged compounds which are fully water-miscible
without addition of emulsifiers and moreover have strong polarity,
have no, or no significant, tendency toward formation of soap scum
deposit in hard water and have sulphur content of at least 8% by
weight.
[0010] Surprisingly, it has now been found that this object is
achieved via sulphur-bridged compounds in which within the molecule
there is at least one fatty acid bonded by way of at least one
sulphur bridge to at least one polyalkylene glycol ester, the
reaction product of a fatty acid with a polyalkylene glycol, and by
virtue of the sulphur bridge(s) these compounds have from 8 to 29%
by weight sulphur content.
[0011] The present invention provides sulphur-bridged compounds in
which within the molecule there is at least one fatty acid bonded
by way of at least one sulphur bridge to at least one polyalkylene
glycol ester, the reaction product of a fatty acid with a
polyalkylene glycol, and by virtue of the sulphur bridge(s) these
compounds have from 8 to 29% by weight sulphur content.
[0012] The polyalkylene glycol ester is preferably polyethylene
glycol ester, polypropylene glycol ester, polybutylene glycol ester
and/or polyalkylene glycol esters in which the ethylene oxide
units, propylene oxide units and/or butylene oxide units are in
random and/or blockwise arrangement. Particular preference is given
to polyethylene glycol ester. In the text hereinafter, another term
used for the polyalkylene glycol esters is
polyalkylene-glycol-esterified fatty acids.
[0013] The sulphur-bridged compounds of the invention, based on
monofunctional polyethylene glycol and on monounsaturated
monocarboxylic acids can be represented diagrammatically by the
following formula (I):
##STR00001##
[0014] The sulphur-bridged compounds of the invention, based on
bifunctional polyethylene glycol and on monounsaturated
monocarboxylic acids can be represented diagrammatically by the
following formula (II):
##STR00002##
[0015] The sulphur-bridged compounds of the invention, based on
trifunctional polyethylene glycol and on monounsaturated
monocarboxylic acids can be represented diagrammatically by the
following formula (III):
##STR00003##
[0016] The sulphur-bridged compounds of the invention, based on
tetrafunctional polyethylene glycol and on monounsaturated
monocarboxylic acids can be represented diagrammatically by the
following formula (IV):
##STR00004##
[0017] For the indices stated, preference is given to the numerical
ranges below:
TABLE-US-00001 Preferred Index Numerical range numerical range a
from 3 to 29 from 5 to 12 b from 3 to 29 from 5 to 12 c from 3 to
29 from 5 to 12 d from 3 to 29 from 5 to 12 e from 3 to 29 from 5
to 12 f from 3 to 29 from 5 to 12 g from 3 to 29 from 5 to 12 h
from 3 to 29 from 5 to 12 p from 3 to 29 from 5 to 12 q from 3 to
29 from 5 to 12 r from 3 to 29 from 5 to 12 s from 3 to 29 from 5
to 12 t from 3 to 29 from 5 to 12 u from 3 to 29 from 5 to 12 v
from 3 to 29 from 5 to 12 w from 3 to 29 from 5 to 12 n from 2 to
10 from 4 to 8 m from 4 to 20 from 8 to 16 k from 2 to 10 from 4 to
8 j from 2 to 10 from 4 to 8 x from 1 to 10 from 2 to 4 y from 2 to
10 from 4 to 8
[0018] The formulae II, III and IV can also comprise further units,
for example polyethylene glycol esters, sulphur bridges and/or
saturated monocarboxylic acids. The sulphur-bridged compounds
represented in all of the formulae are based on polyethylene
glycols. The invention also encompasses, alongside the polyethylene
glycols, polypropylene glycols, polybutylene glycols and/or
polyalkylene glycols in which the ethylene oxide units, propylene
oxide units and/or butylene oxide units are in random and/or
blockwise arrangement. It is moreover possible to use the
monofunctional, bifunctional, trifunctional and tetrafunctional
polyalkylene glycols in the form of mixture. It is also possible to
use, alongside the monounsaturated monocarboxylic acids,
unsaturated fatty acids which have any desired number of double
bonds, triple bonds and/or carboxylic acid units.
[0019] The sulphur-bridged compounds of the invention can be
produced by way of the 3 embodiments specified below, preference
being given here to the first embodiment:
[0020] 1) The sulphur-bridged compounds obtainable via the reaction
of the unsaturated fatty acids with sulphur and/or hydrogen
sulphide to give sulphur-bridged fatty acids, preferably
sulphur-bridged saturated fatty acids, and the subsequent reaction
of these sulphur-bridged fatty acids with polyalkylene glycol.
[0021] 2) The sulphur-bridged compounds are obtainable via the
reaction of the unsaturated fatty acids with polyalkylene glycol to
give the intermediate product composed of unsaturated polyalkylene
glycol ester and unesterified unsaturated fatty acid, and the
subsequent reaction of this intermediate product with sulphur
and/or hydrogen sulphide.
[0022] 3) The sulphur-bridged compounds are obtainable via mixing
of the unsaturated fatty acids with unsaturated fatty acid
polyalkylene glycol esters which result from a reaction of
unsaturated fatty acids with polyalkylene glycol or with alkylene
oxides, and the subsequent reaction of this mixture with sulphur
and/or hydrogen sulphide.
[0023] For the purposes of this invention, polyalkylene glycol is a
monofunctional, bifunctional, trifunctional and/or tetrafunctional
polyalkylene glycol.
[0024] The monofunctional polyalkylene glycols are preferably
linear polylalkylene glycols which have one hydroxy group, where
alkylene is preferably ethylene, propylene and/or butylene,
particularly preferably ethylene. The molar mass of the
monofunctional polyalkylene glycols is preferably from 100 to 500
g/mol. These can be produced via the reaction of monofunctional
alcohols, preferably methanol, with alkylene oxides. The
monofunctional polyalkylene glycols are by way of example
obtainable with trade name Polyglykol M from Clariant International
AG.
[0025] The bifunctional polyalkylene glycols are preferably linear
polylalkylene glycols which have two hydroxy groups, where alkylene
is preferably ethylene, propylene and/or butylene, particularly
preferably ethylene. The molar mass of the bifunctional
polyalkylene glycols is preferably from 200 to 1000 g/mol. These
can be produced via the reaction of bifunctional alcohols,
preferably ethylene glycol or diethylene glycol, with alkylene
oxides. The bifunctional polyalkylene glycols are by way of example
obtainable with trade name Pluriol.RTM. E from BASF SE.
[0026] The trifunctional polyalkylene glycols are preferably
branched polylalkylene glycols which have three hydroxy groups,
where alkylene is preferably ethylene, propylene and/or butylene,
particularly preferably ethylene. The molar mass of the
trifunctional polyalkylene glycols is preferably from 300 to 1500
g/mol. These can be produced via the reaction of trifunctional
alcohols, preferably glycerol, with alkylene oxides. The
trifunctional polyalkylene glycols are by way of example obtainable
with trade name Ucon TPEG from The Dow Chemical Company.
[0027] The tetrafunctional polyalkylene glycols are preferably
branched polylalkylene glycols which have four hydroxy groups,
where alkylene is preferably ethylene, propylene and/or butylene,
particularly preferably ethylene. The molar mass of the
tetrafunctional polyalkylene glycols is preferably from 400 to 2000
g/mol. These can be produced via the reaction of tetrafunctional
alcohols, preferably pentaerythritol, with alkylene oxides. The
tetrafunctional polyalkylene glycols are by way of example
obtainable with trade name Polyglykol P41 from Clariant
International AG.
[0028] Among the abovementioned alkylene oxides, preference is
given to ethylene oxide, propylene oxide and/or butylene oxide.
These are obtainable commercially by way of example from BASF
SE.
[0029] The production of polyalkylene glycols is described in
general terms in Lubricants and Lubrication, 2001, p. 75.
[0030] The at least one fatty acid and the at least one
polyalkylene-glycol-esterified fatty acid (polyalkylene glycol
ester) preferably involves unsaturated carboxylic acids, preferably
unsaturated monocarboxylic acids, which preferably have a
carbon-chain length of from 6 to 32 C atoms. Starting materials
that can be used are not only pure unsaturated monocarboxylic acids
but also mixtures of monocarboxylic acids which comprise
unsaturated monocarboxylic acids as main constituents and saturated
monocarboxylic acids as ancillary constituents.
[0031] The reaction with sulphur and, respectively, polyalkylene
glycol uses unsaturated fatty acids, preferably unsaturated
monocarboxylic acids. Preference is given here to oleic acid and
linoleic acid, which are used as main constituents of a fatty acid
mixture in one particularly preferred embodiment of the
invention.
[0032] The fatty acid mixtures are preferably obtained from oils of
natural origin, and can also comprise a proportion of saturated
fatty acids alongside the unsaturated fatty acids. Examples of oils
of natural origin are babassu oil, cottonseed oil, borage oil,
safflower oil, peanut oil, blackcurrant seed oil, hazelnut oil,
herring oil, tung oil, jojoba oil, coconut oil, neatsfoot oil, bone
oil, lard oil (=pork lard), liver oil, linseed oil, corn oil,
almond oil, olive oil, palm oil, palm kernel oil, rapeseed oil,
beef tallow oil (=beef lard), castor oil, sardine oil, mustard seed
oil, soya bean oil, sunflower oil, shea butter, tall oil, grapeseed
oil, whale oil and walnut oil. Refined variants of these are
preferably used. Preference is given here to fatty acid mixtures
which include more than 80% by weight of unsaturated fatty
acids.
[0033] The unsaturated fatty acid polyalkylene glycol esters which
are used as starting material according to the third embodiment are
produced via the reaction of unsaturated fatty acids with
polyalkylene glycols or alkylene oxides. These are products which
are obtainable commercially but which however, as mentioned above,
can also be produced via the reaction of unsaturated fatty acids
with polyalkylene glycols or alkylene oxides. In this connection,
in relation to the preferred unsaturated fatty acids, polyalkylene
glycols and alkylene oxides reference is made to what has been said
above. This reaction of unsaturated fatty acids with polyalkylene
glycols is preferably carried out at temperatures of from 120 to
200.degree. C. and at pressures of from 20 mbar to atmospheric
pressure and with a reaction time of from 4 to 24 h with use of an
acidic catalyst. The reaction of unsaturated fatty acids with
alkylene oxides is preferably carried out at a temperature of from
100 to 190.degree. C. and at a pressure of from 1 to 6 bar with use
of a nucleophilic catalyst. The unsaturated fatty acid polyalkylene
glycol esters are obtainable by way of example from Sasol Germany
GmbH with trademarks Marlosol.RTM. and Marlowet.RTM..
[0034] The production of fatty acid polyalkylene glycol esters is
described in general terms in Chemistry and Technology of
Surfactants, 2006, pp. 139 and 140.
[0035] The sulphur-bridged compounds of the invention can also be a
constituent of a mixture.
[0036] The invention further provides mixtures comprising the
sulphur-bridged compounds of the invention and additionally further
additives and/or carrier liquids.
[0037] Preference is given here to further high-pressure additives,
sulphur additives, antiwear additives, phosphorus additives,
corrosion inhibitors, sulphonates, sulphonic acids, sulphonic
esters, carboxylates, carboxylic acids, carboxylic esters,
nonferrous-metal deactivators, triazoles, triazole derivatives,
surfactants, emulsifiers, dispersing agents, solubilizers,
carboxylic acid alkoxylates, carboxamides, fatty alcohols, fatty
alcohol alkoxylates, ether carboxylic acids, glycols, glycol
ethers, polyalkylene glycols, alkalizers, alkylamines,
alkanolamines, lubricity improvers, monoglycerides, diglycerides,
triglycerides, biocides, antifoams, antioxidants, complexing
agents, sequestering agents, demulsifiers, viscosity-index
improvers, flame retardants, dyes, odorants, and also Group Ito V
oils according to the definition of the American Petroleum
Institute (API).
[0038] The present invention further provides processes for the
production of the sulphur-bridged compounds of the invention:
[0039] Preference is given here to the 3 embodiments specified
below.
[0040] 1) The unsaturated fatty acid, preferably the unsaturated
monocarboxylic acid, is first reacted with sulphur and/or hydrogen
sulphide to give the sulphur-bridged fatty acid, preferably
sulphur-bridged saturated fatty acid, and then this sulphur-bridged
fatty acid is reacted with at least one polyalkylene glycol in such
a way that at least one carboxylic acid unit of the fatty acid is
present within the sulphur-bridged compounds of the invention.
[0041] 2) A molar excess of unsaturated fatty acid, preferably of
unsaturated monocarboxylic acid, is reacted with at least one
polyalkylene glycol to give the intermediate product composed of
unsaturated polyalkylene glycol ester and unesterified unsaturated
fatty acid, and then this intermediate product is reacted with
sulphur and/or hydrogen sulphide in such way that at least one
carboxylic acid unit of the fatty acid is present within the
sulphur-bridged compounds of the invention.
[0042] 3) The unsaturated fatty acid, preferably the unsaturated
monocarboxylic acid, is mixed with at least one unsaturated fatty
acid polyalkylene glycol ester and then this mixture is reacted
with sulphur and/or hydrogen sulphide in such a way that at least
one carboxylic acid unit of the fatty acid is present within the
sulphur-bridged compounds of the invention.
[0043] The determination of the carboxylic acid unit takes place by
way of the acid number according to ASTM D664 or DIN 53402. In the
first and second embodiments of the process of the invention, the
reaction of the fatty acid and/or sulphur-bridged fatty acid with
the polyalkylene glycol is detected via the acid-number. The
juncture at which the reaction is terminated is no later than that
at which at least one carboxylic acid unit is still present.
[0044] The first and second embodiment of the process of the
invention preferably use the starting materials in the following
ratios:
[0045] a) Based on 1 g of unsaturated fatty acid, preferably
unsaturated monocarboxylic acid, from 0.05 g to 1 g of polyalkylene
glycol is used; and
[0046] b) based on 1 g of unsaturated fatty acid, preferably
unsaturated monocarboxylic acid, from 0.05 g to 0.5 g of sulphur is
used.
[0047] The third embodiment of the process of the invention
preferably uses the starting materials in the following ratios:
[0048] a) Based on 1 g of unsaturated fatty acid, preferably
unsaturated monocarboxylic acid, from 0.2 g to 4 g of unsaturated
fatty acid polyalkylene glycol ester is used; and
[0049] b) based on 1 g of unsaturated fatty acid, preferably
unsaturated monocarboxylic acid, from 0.05 g to 0.5 g of sulphur is
used.
[0050] In all of the embodiments of the processes of the invention,
the reaction with sulphur and/or hydrogen sulphide
("sulphurization") is preferably carried out at pressures from
atmospheric pressure (i.e. in the range from 0.9 to 1.1 bar) to 15
bar and at temperatures of from 119 to 170.degree. C. and with a
reaction time of from 4 to 24 h.
[0051] In the first and second embodiment of the process of the
invention, it is preferable that the esterification is carried out
at atmospheric pressure (i.e. in the range from 0.9 to 1.1 bar),
with subsequent reduction to pressures extending as far as 10 mbar,
the reaction being carried out at temperatures of from 120 to
200.degree. C. and with a reaction time of from 4 to 24 h.
[0052] In the third embodiment of the process of the invention, the
mixing is preferably carried out at atmospheric pressure and at
temperatures of from 15 to 100.degree. C. and with a mixing time of
from 5 to 30 min.
[0053] In further embodiments of the present invention, preference
is given to the reaction conditions specified below:
[0054] In the first embodiment of the process of the invention, it
is preferable that the unsaturated fatty acid, preferably the
unsaturated monocarboxylic acid, is first reacted with sulphur
and/or hydrogen sulphide and then with polyalkylene glycol,
preferably polyethylene glycol, to give the sulphur-bridged
compounds of the invention. In the first step, the unsaturated
monocarboxylic acid is sulphurized with sulphur and/or hydrogen
sulphide in a pressure reactor at from atmospheric pressure to 15
bar, preferably 4 bar, and at from 119 to 170.degree. C.,
preferably 130.degree. C. The sulphurization is preferably
catalysed by amines, metal oxides or acids. In the second step, the
intermediate product is esterified with polyalkylene glycol,
preferably polyethylene glycol at from atmospheric pressure to 10
mbar and at from 120 to 200.degree. C., preferably 180.degree. C.
The esterification is preferably continued until no further water
is removed by distillation. The esterification is preferably
catalysed by tin salts or by acids, preferably by phosphoric acid
and/or p-toluenesulphonic acid.
[0055] In the second embodiment of the process of the invention, it
is preferable that a molar excess of unsaturated fatty acid,
preferably the unsaturated monocarboxylic acid, is first reacted
with polyalkylene glycol, preferably polyethylene glycol, and then
with sulphur and/or hydrogen sulphide to give the sulphur-bridged
compounds of the invention. In the first step, the unsaturated
monocarboxylic acid is esterified with polyalkylene glycol,
preferably polyethylene glycol, at from atmospheric pressure to 10
mbar and at from 120 to 200.degree. C., preferably 180.degree. C.
The esterification is preferably continued until no further water
is removed by distillation. The esterification is preferably
catalysed by tin salts or by acids, preferably by phosphoric acid
or p-toluenesulphonic acid. In the second step, the intermediate
product which comprises unsaturated polyalkylene glycol ester and
unesterified unsaturated fatty acid is sulphurized with sulphur
and/or hydrogen sulphide in a pressure reactor at from atmospheric
pressure to 15 bar, preferably 4 bar, and at from 119 to
170.degree. C., preferably 130.degree. C. The sulphurization is
preferably catalysed by amines, metal oxides or acids.
[0056] In the third embodiment of the process of the invention, the
unsaturated fatty acid, preferably the unsaturated monocarboxylic
acid, is first mixed with the unsaturated fatty acid polyalkylene
glycol ester and then reacted with sulphur and/or hydrogen sulphide
to give the sulphur-bridged compounds of the invention. In the
first step, the unsaturated monocarboxylic acid is mixed with the
unsaturated fatty acid polyalkylene glycol esters at atmospheric
pressure and from 15 to 100.degree. C., preferably 40.degree. C. In
the second step, the mixture is sulphurized with sulphur and/or
hydrogen sulphide in a pressure reactor at from atmospheric
pressure to 15 bar, preferably 4 bar, and at from 120 to
170.degree. C., preferably 130.degree. C. The sulphurization is
preferably catalysed by amines, metal oxides or acids.
[0057] The present invention further provides a process for the
production of a mixture according to which lubricant additives and
carrier liquids are additionally added before, during or after the
production of the sulphur-bridged compounds of the invention.
[0058] The addition process can use commercially available mixing
assemblies, preferably stirred tanks.
[0059] The present invention further provides the use of the
sulphur-bridged compounds of the invention as sulphur carrier
and/or as lubricant additive in all lubricants according to ISO
6743, for example preferably lubricants for metalworking or
lubricants for machinery.
[0060] The sulphur-bridged compounds of the invention are
preferably used as lubricant additive in water-miscible or
water-mixed cutting fluids. These are described in DIN 51385.
[0061] The scope of the invention encompasses combinations of all
of the moiety definitions, indices, parameters and explanations
provided above and listed below in general terms or in preferred
ranges, i.e. also encompasses any desired combination between the
respective ranges and preferred ranges.
[0062] The examples below serve to illustrate the invention without
any resultant limiting effect.
INVENTIVE EXAMPLES
[0063] In the Example that follows, the percentages relate to % by
weight.
[0064] Reagents:
[0065] Additin.RTM. RC 5250, sulphur-bridged fatty acids based on a
vegetable fatty acid mixture (composed of: >90% by weight of
unsaturated fatty acids, main constituents oleic acid and linoleic
acid), with sulphur content about 15% by weight; producer: Rhein
Chemie Rheinau GmbH.
[0066] Pluriol.RTM. E 600, linear bifunctional polyethylene glycol,
average molar mass: about 600 g/mol; producer: BASF SE.
[0067] The following components were mixed by means of a magnetic
stirrer at about 25.degree. C. (Mixture A1): 20.00 g of
Additin.RTM. RC 5250
[0068] 10.00 g of Pluriol.RTM. E 600
[0069] 0.03 g of phosphoric acid, 75% by weight
[0070] The acid number was 115.9 mg of KOH/g.
[0071] The method for the Examples was as follows:
[0072] 5 drops were taken from the Mixture A1 and added to about 50
ml of drinking water of hardness 20.degree. dH (sample A1) at about
25.degree. C. After sample A1 had been mixed by stirring, insoluble
droplets remained in the water.
[0073] 20 g of the Mixture A1 were then heated in an open glass
beaker at 120.degree. C. with the use of a magnetic stirrer. After
a reaction time of 6 hours, the reaction product, i.e. a mixture of
the sulphur-bridged compounds of the invention, and where
appropriate of unreacted starting materials and by-products, was
cooled to room temperature (Mixture A2). 5 drops were likewise
taken from the Mixture A2 and added to about 50 ml of drinking
water of hardness 20.degree. dH (sample A2). After the sample A2
had been mixed by stirring, the droplets were emulsified in water
and formed an emulsion with coarse disperse phase.
[0074] Finally, a few drops of aqueous potassium hydroxide solution
were added to each of the samples A1 and A2 until a pH>10 had
been reached. In the neutralized sample A1, voluminous precipitate
formed, and in the neutralized sample A2 an emulsion with fine
disperse phase formed and exhibited a slight, fine sediment only
after some days.
[0075] The table below collates the results of the Examples:
TABLE-US-00002 Mixture A1 Mixture A2 (Comparison) (Of the
invention) Solubility in drinking Insoluble Emulsion with coarse
water disperse phase Solubility in drinking Voluminous Emulsion
with fine water after neutralization precipitate disperse phase
Acid number measured 115.9 mg of KOH/g 85.4 mg of KOH/g after 6
hours Corrected acid number 114.6 mg of KOH/g 84.1 mg of KOH/g
(=measured acid number after deduction of the calculated acid
number of the phosphoric acid content) Measured sulphur content
10.3% by weight 10.3% by weight
[0076] The Mixture A1 had reacted after a reaction time of 6 hours
to give the product of the invention (Mixture A2). The
sulphur-bridged compounds of the invention have 10.3% by weight
sulphur content. The acid number of the product of the invention is
85.4 mg of KOH/g. The reduced acid number proves that within the
sulphur-bridged compounds there are not only unesterified fatty
acids but also polyethylene-glycol-esterified fatty acids
(polyethylene glycol esters). The value for the Mixture A1
(Comparison) remained unchanged.
[0077] Quantitative studies were moreover carried out to determine
soap scum deposit. To this end, each of the Mixtures A1 and A2 was
dissolved at 0.3% by weight at about 25.degree. C. in water
according to DIN 51367 with a defined total hardness of 3.58
mmol/litre, corresponding to 20.degree. dH. Aqueous potassium
hydroxide solution (45% by weight) was admixed with each of these
solutions until a pH of 11.0.+-.0.2 had been achieved. In order to
facilitate dissolution of the Mixtures A1 and A2 in water, most of
the aqueous potassium hydroxide solution required was first
dissolved in water. Each of the Mixtures A1 and A2 was then slowly
added dropwise during constant stirring. Finally, a pH of 11.0
.+-.0.2 was established with the aqueous potassium hydroxide
solution.
[0078] The 0.3 per cent by weight solution of the Mixture A1 is
termed Solution A1, and the 0.3 per cent by weight solution of the
Mixture A2 is termed Solution A2. The pH of the Solutions A1 and A2
was 11.0.
[0079] The freshly mixed Solution A1 comprised voluminous suspended
precipitate; after 24 h the precipitate sunk to the bottom, and
above the sediment there was an emulsion visible with fine disperse
phase. The freshly mixed Solution A2 was an emulsion with fine
disperse phase; after 24 h the emulsion still had a fine disperse
phase, but a slight, fine sediment was apparent.
[0080] After 24 h, the matured Solutions A1 and A2 were filtered by
using prepleated filters (Macherey-Nagel 615 1/4). The residues
(soap scum) in the filter were dried at 105.degree. C. for 2 h and
analysed gravimetrically.
TABLE-US-00003 Mixture A1 Mixture A2 (Comparison) (Of the
invention) Mass of residue (scum) 0.89 g 0.36 g Input weight of
mixture 1.50 g 1.50 g Ratio of mass of residue to 59% by weight 24%
by weight input weight of mixture
[0081] In the case of the Mixture A1 the mass of the residue was
0.89 g. In the case of the Mixture A2 of the invention the mass of
the residue was only 0.36 g.
[0082] Summary:
[0083] With the Inventive Examples it was possible to show clearly
that when the product of the invention (Mixture A2) is used there
was significantly less soap scum deposit.
[0084] Experiments have shown that the object of the present
invention has been achieved. After adequate reaction time, the
Mixture A1 was modified in such a way as to provide a product
(Mixture A2) which is water-miscible without addition of
emulsifier, and has high polarity, has no, or no significant,
tendency towards formation of soap scum deposit in hard water, and
has high sulphur content.
* * * * *