Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Organic phosphorus compound – wherein the phosphorus is...
Reexamination Certificate
2002-10-31
2004-08-24
McAvoy, Ellen M (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Organic phosphorus compound, wherein the phosphorus is...
C508S279000, C508S433000, C508S440000, C508S459000, C508S530000, C508S539000, C508S579000, C508S583000, C252S389200, C252S396000, C516S056000, C516S057000, C516S075000, C516S076000
Reexamination Certificate
active
06780824
ABSTRACT:
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention relates to an emulsifier system, which is suitable for the production of low-foaming oil-in-water emulsions in soft and in hard water. The emulsifier system can be supplemented with suitable carboxylic acids to form an anti-corrosive system. The invention further relates to an oil-containing, water-miscible emulsion concentrate containing the emulsifier system according to the invention, and ready-to-use oil-in-water emulsions made therefrom. These emulsions display only a low tendency to foam, even in soft water and can be used for various technical metalworking processes, e.g. as cleaning, anti-corrosive or low-temperature lubricant emulsions. The emulsions can also be used with hard water. They are stable even at quite high levels of water hardness and have the additional advantage that they hold water hardness (calcium carbonate) in dispersion.
Anti-corrosive emulsions are used as passivating agents for the temporary protection of metallic workpieces against atmospheric influences causing corrosion. They contain substantially non-polar or polar oils, emulsifiers, corrosion inhibitors and water. Commercial systems are based on oil concentrates containing emulsifiers and corrosion inhibitors, but little or no water. The emulsifiers and corrosion inhibitors used must therefore be oil-soluble. For the production of oil-in-water emulsions (“O/W emulsions”), which are used in water-diluted form, these systems must be self-emulsifying.
Low-temperature lubricant emulsions, which are used in shaping metallic workpieces with or without cutting, have a similar composition to anti-corrosive emulsions, since they also have to display a corrosion-inhibiting action. By adding suitable lubricant additives, the lubricant action can be improved.
All these types of emulsion have in common the fact that they tend to foam owing to the emulsifiers used. The tendency to foam is particularly marked if the emulsifier system contains anionic surfactants. When used in hard water, the tendency to foam is reduced by the fact that the anionic surfactants can form sparingly soluble salts with calcium ions, which have a foam-inhibiting effect. In soft to moderately hard water, i.e. in water with less than 120°and especially with less than 80° dH, these emulsions cannot be used because of the high tendency to foam, at least when working by a spray method.
DESCRIPTION OF RELATED ART
DE-A-197 03 083 discloses a low-foam emulsifier system consisting of
a) ethoxylates/propoxylates of fatty alcohols with 8 to 18 C atoms in the alcohol with 2 to 6 ethylene oxide units and 4 to 8 propylene oxide units and
b) fatty alcohols and/or fatty alcohol propoxylates with 12 to 24 C atoms in the alcohol and 0 to 3 propylene oxide units and/or distillation residue of these fatty alcohols in a weight ratio of a:b=1:0.3 to 0.3:1. This emulsifier system is suitable for the production of emulsions with soft water, since it imparts only a very low foaming tendency to these emulsions. For the production of emulsions with moderately hard or hard water, i.e. with water having a hardness of more than 8° dH, especially with more than 12° dH, however, this emulsifier system is less suitable, since the emulsions with this type of water added do not exhibit satisfactory stability.
This is improved according to the teaching of DE-A-19956237. This document describes an emulsifier system consisting of
a) ethoxylates/propoxylates of fatty alcohols with 8 to 18 C atoms in the alcohol with 2 to 6 ethylene oxide units and 4 to 8 propylene oxide units,
b) fatty alcohols and/or fatty alcohol propoxylates with 12 to 24 C atoms in the alcohol and 0 to 3 propylene oxide units and/or distillation residue of these fatty alcohols and
c) ether carboxylic acids of the general formula (I) or the anions thereof
R—O—(CHA—CH
2
O)
n
—(CH
2
)
m
—COOH (I),
wherein R denotes a saturated or unsaturated, linear or branched alkyl residue with 5 to 22 C atoms,
A denotes hydrogen or a methyl group,
n denotes a number in the range of 1.5 to 15 and
m denotes an integer in the range of 1 to 3,
in the weight ratio a:b:c=1:0.3:0.1 to 1:4:1.
The above document also discloses an anti-corrosive and emulsifier system consisting of
8 to 40 parts by weight of one or more straight-chained or branched carboxylic acids with 6 to 12 C atoms or the anions thereof, and
7 to 50 parts by weight of emulsifier component composed of
a) ethoxylates/propoxylates of fatty alcohols with 8 to 18 C atoms in the alcohol with 2 to 6 ethylene oxide units and 4 to 8 propylene oxide units,
b) fatty alcohols and/or fatty alcohol propoxylates with 12 to 24 C atoms in the alcohol and 0 to 3 propylene oxide units and/or distillation residue of these fatty alcohols and
c) ether carboxylic acids of the general formula (I) or the anions thereof.
The said document also provides oil-containing emulsion concentrates and anti-corrosive and low-temperature lubricant emulsions obtainable therefrom.
Emulsions according to the document cited above, which contain ether carboxylic acids, display good initial foam properties when used in practice. However, it has been shown in practice that the foam behaviour deteriorates with an increasing period of use. In low-temperature lubricant equipment filled with corresponding emulsions, only negligible foaming occurs at first. After a period of use of several days, however, undesirable foaming of varying intensity can occur. The present invention is based on the object of providing an improved emulsifier system, emulsion concentrates containing this and anti-corrosive and low-temperature lubricant emulsions obtainable therefrom.
BRIEF SUMMARY OF THE INVENTION
In a first aspect the invention relates to an emulsifier system containing
a) ethoxylates/propoxylates of fatty alcohols with 8 to 18 C atoms in the alcohol with 2 to 6 ethylene oxide units and 4 to 8 propylene oxide units,
b) fatty alcohols and/or fatty alcohol propoxylates with 12 to 24 C atoms in the alcohol and 0 to 3 propylene oxide units and
c) phosphates, selected from
c1) mono- and/or diesters of phosphoric acid with alkanols with 10-20 C atoms,
c2) mono- and/or diesters of phosphoric acid with ethoxylated and/or propoxylated alkanols with 10-20 C atoms and/or
c3) phosphates of polyethylene glycol ethers and/or polypropylene glycol ethers
and the water-soluble salts of each of these, in a weight ratio a:b:c=1:0.3:0.1 to 1:4:1, preferably in a weight ratio of 1:1:0.1 to 1:3:0.5. All the alcohols mentioned can be straight-chained, branched, saturated or unsaturated. Straight-chained alcohols are particularly preferred. The monoesters of phosphoric acid with ethoxylated, straight-chained alcohols with 10-20 C atoms are preferably used as the phosphates of group c). In addition to the acid esters of group c), their water-soluble salts can be used, i.e. salts that are water-soluble in the concentration ranges described below at conventional working temperatures of between 15 and 95° C. The sodium, potassium, ammonium or alkanolamine salts are particularly suitable for this.
DETAILED DESCRIPTION OF THE INVENTION
The use of phosphates c) in cleaning and anti-corrosive agents is known from EP-B-124 851. The esters listed there can also be used within the framework of the present invention. As phosphates with ethoxylated and/or propoxylated alkanols with 10-20 C atoms (group c2), those having 2 to 20, preferably 4 to 14, ethylene oxide and/or propylene oxide units are particularly suitable. Phosphates of group c3) can be obtained e.g. by reacting 10 parts of dipropylene glycol with 282 parts of propylene oxide and 30.5 parts of polyphosphoric acid. By varying the quantitative ratios, correspondingly modified esters are obtained.
Narrow requirements have therefore to be laid down for the composition of the emulsifier system and the molecular structure of the emulsifiers used. On the one hand, according to a) fatty alcohol ethoxylates/propoxylates having both 2 to 6 ethylene oxide units and 4 to 8 propylene oxide units must
Geke Juergen
Oelscher Hans-Peter
Henkel Kommanditgesellschaft auf Aktien (Henkel KGaA)
McAvoy Ellen M
LandOfFree
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