Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Description
AQUEOUS LUBRICANT AND PROCESS FOR COLD FORMING METAL,
WITH IMPROVED FORMED SURFACE QUALITY
BACKGROUND OF THE INVENTION
This invention relates to aqueous liquid lubricant compositions suitable for
form-
ing a coating containing an organic binder material on metal surfaces that are
coated
with a layer of the liquid composition and then dried without rinsing, so that
the solids
s content of the aqueous composition forms on the metal surface a solid layer
that
lubricates the surface during subsequent cold working operations. The solid
film thus
deposited is protective against mechanical damage during cold working of the
un-
derlying metal. The metal surface processed as described above may or may not
have
other surtace layers, such as phosphate or chromate conversion coatings,
coatings
formed by anodization, complex oxide layers such as those that can be formed
with a
commercially available product named BONDERITE~ 770X from the Henkel Surface
Technologies Div. of Henkel Corp., Madison Heights, Michigan, or the like,
underlying
the coating produced on the surface by using this invention. This invention is
generally
applicable to cold working most metals, especially steel and aluminum alloys.
,5 Many aqueous liquid compositions that form coatings on metal surfaces that
pro-
test the metal surface while it is being cold worked are known. The previously
most ef-
fective ones have generally been zinc, calcium, andlor sodium soaps applied
over a
preceding heavy phosphate conversion coating on steel substrates or over a
complex
calcium aluminate conversion coating on aluminum substrates. (Normally, a
sodium
zo stearate or other sodium soap salt is applied over a zinc phosphate coating
or a calcium
aluminate coating. Reaction between the sodium soap and the zinc or calcium in
the
previous conversion coating is believed to result in both zinc or calcium soap
and
sodium soap layers.) However, this combination is environmentally
disadvantageous,
especially when used over phosphate coatings, because the liquid compositions
used
zs to form phosphate coatings generally contain some types of metal ions, such
as those
of zinc, nickel, manganese, and/or the like, that are regarded as polluting,
and the phos-
phate ions themselves, which are required in phosphate conversion coating
forming li-
quid compositions, are environmentally undesirable in waste waters because of
their
promotion of eutrophication of natural bodies of water. Zinc and calcium soaps
are
so substantially insoluble in water, but cause workplace nuisances at best and
hazards at
worst because they tend to form fine dust particles in the air around sites of
cold working
processes when used as cold working lubricants.
1
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Various polymer based lubricants have been taught in the art as replacements
for the combination of stearates over zinc phosphate conversion coatings, but
heretofore
none of the polymer based lubricants have proved to be commercially acceptable
in all
applications. A frequently objectionable feature of commercial use of prior
polymeric
s lubricants is.the.presence-of.scratches-on-the.surface-of-the-cald.worked
article_
A major object of this invention is to provide lubricants and processes that
will
eliminate or at least reduce the environmental disutilities noted above while
still achiev-
ing cold working performance that is adequate when compared with the prior art
use of
phosphate conversion coatings followed by zinc soap application. Other
alternative or
concurrent objects are to reduce total energy andlor other costs of cold
forming
operations, particularly by reducing process related waste of objects being
cold worked,
more particularly because of rejection for scratched surfaces, and/or by
achieving higher
production rates per unit time. Still another alternative or concurrent object
is to provide
a lubricant satisfactory for extruding under the more severe conditions in
current com-
,s mercial practice.
Except in the claims and the operating examples, or where otherwise expressly
indicated, all numerical quantities in this description indicating amounts of
material or
conditions of reaction and/or use are to be understood as modified by the word
"about"
in describing the broadest scope of the invention. Practice within the
numerical limits
zo stated is generally preferred. Also, throughout this description, unless
expressly stated
to the contrary: percent, "parts of', and ratio values are by weight; the term
"polymer"
includes "oligomer", "copolymer", "terpolymer", and the like; the description
of a group
or class of materials as suitable or preferred for a given purpose in
connection with the
invention implies that mixtures of any two or more of the members of the group
or class
z5 are equally suitable or preferred; description of constituents in chemical
terms refers to
the constituents at the time of addition to any combination specified in the
description
or of generation in situ by chemical reactions specified in the description,
and does not
necessarily preclude other chemical interactions among the constituents of a
mixture
once mixed; specification of materials in ionic form additionally implies the
presence of
so sufficient counterions to produce electrical neutrality for the composition
as a whole (any
counterions thus implicitly specified should preferably be selected from among
other
constituents explicitly specified in ionic form, to the extent possible;
otherwise such
counterions may be freely selected, except for avoiding counterions that act
adversely
to the objects of the invention); and the term "mole" and its grammatical
variations may
35 be applied to elemental, ionic, and any other chemical species defined by
number and
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type of atoms present, as welt as to compounds with well defined molecules.
BRIEF SUMMARY OF THE INVENTION
It has been found that a lubricant composition comprising, preferably
consisting
essentially of, or more preferably consisting of, a combination of:
s (A) a component selected from the group consisting of ethoxylated straight
chain
aliphatic alcohol molecules, wherein the initial alcohol molecules have a
single
-OH moiety and at least 18 carbon atoms; and
(B) a component selected from the group consisting of lithium salts, sodium
salts,
and calcium salts of fatty organic acids; and, optionally but preferably,
(C) a component selected from the group consisting of inorganic boron
containing
acids and salts thereof; and, optionally, one or more of the following
components:
(D) a component selected from the group consisting of condensation products of
ethylene oxide and/or propylene oxide with triglycertdes of fatty acids that
~5 include moieties condensable with ethylene oxide;
(E) a component of at least partially neutralized copolymers of (i) an alkene
that con
tains no carboxyl or carboxylate group and (ii) a comonomer that is an organic
acid including the moiety C=C-COOH, such at least partially neutralized copoly
mers of organic acids often being denoted in the art generally and hereinbelow
Zo as "ionomers";
(F) a component of organic corrosion inhibitors that are not part of any of
immediately previously recited components (A) through (E);
(G) a component of surfactant molecules that are not part of any of
immediately
previously recited components (A) through (F); and
25 (H) a component of antifoam agent molecules that are not part of any of
previously
immediately recited components (A) through (G)
effectively achieves at least one of the objects of the invention as stated
above.
Embodiments of the invention include working aqueous liquid compositions suit-
able for contacting directly with metal surtaces to provide protective
coatings thereon af-
ao ter drying; liquid or solid concentrates that will form such working
aqueous liquid compo-
sitions upon dilution with water only; processes of using working aqueous
liquid compo-
sitions according to the invention as defined above to form protective
coatings on metal
surfaces and, optionally, to further process the metal objects with surfaces
so protected;
protective solid coatings on metal surtaces formed in such a process, and
metal articles
35 bearing such a protective coating. In addition to the essential ingredients
noted above,
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aqueous compositions according to the invention will of course contain water,
but most
if not all of the water is normally removed by drying before lubricating
coating formed in
a process according to the invention is actually utilized for its major
lubricating function
in cold working.
s DETAILED DESCRIPTION OF THE INVENTION
For various reasons, almost always including at least a cost saving from
elimina-
tion of an unnecessary ingredient, it is preferred that a composition
according to this in-
vention should be largely free from various materials often used in prior art
composi-
tions. In particular, compositions according to this invention in most
instances preferably
do not contain, with increasing preference in the order given, and with
independent pref
erence for each component named, more than 5, 4, 3, 2, 1, 0.5, 0.25, 0.12,
0.06, 0.03,
0.015, 0.007, 0.003, 0.001, 0.0005, 0.0002, or 0.0001 % of each of (i)
hydrocarbons, (ii)
fatty oils of natural origin that have not been modified by chemical reaction
from their
naturally occurring form, (iii) other ester oils and greases that are liquid
at 25° C, (iv)
,s metal salts of fatty acids, (v) hexavalent chromium, (vi} nickel cations,
(vii) cobalt rat-
ions, (viii) copper rations, (ix} manganese in any ionic form, (x) graphite,
(xi) molyb-
denum sulfide, (xii) copolymers of styrene and malefic moieties, (xiii)
oxidized polyethyl-
ene, (xiv) urethane polymers and copolymers, (xv) alkoxylates of Guerbet
alcohols, and
(xvi) polyoxyalkylene polymers not containing an end group having at least 17
carbon
2o atoms in a chain without any intervening carbon-oxygen bonds. (For purposes
of this
description, the term "malefic moiety" is defined as a portion of a polymer
chain that con-
forms to one of the following general chemical formulas:
H H O-Q1
zs -C- C=O -C- C=O
O
-C- C=O -C- C=O
30
H H O-Qz
wherein each of Q~ and Qz, which may be the same or different, is selected
from the
group consisting of hydrogen, alkali metal, ammonium, and substituted ammonium
rat-
ions.) For possible constituents (xii) - (xvi) as noted above, it is
independently preferred
3s that the ratio of the concentration in a composition according to the
invention of each of
these possible constituents to the concentration of necessary constituent (A)
as noted
above is, with increasing preference in the order given, not more than 2, 1.5,
1.0, 0.9,
0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.15, 0.10, 0.07, 0.05, 0.03, 0.02, 0.01,
0.007, 0.005,
0.003, or 0.002. However, all the preferences stated in this paragraph are
subordinated
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to the explicit descriptions of specific materials herein as a necessary,
preferred, or
optional constituent of a composition according to this invention, so that a
material
specifically described as necessary, optional, or preferred may be present in
a
composition according to this invention even if it is a member of some larger
class that
s is unpreferred as noted earlier in this paragraph.
The absolute concentrations of the various necessary, preferable, and optional
ingredients in aqueous working or concentrate compositions according to the
invention
are not at all narrowly limited, and the preferences for concentrations of
their
predominant constituents are largely determined by the viscosity for both
working and
,o concentrate compositions. In a concentrate composition, the concentration
of non-
volatile ingredients preferably is as high as can be effectively utilized by
the equipment
available for removing the concentrate from its container and mixing the
concentrate
composition with water, and sometimes other materials, to form a working
composition.
In a working composition itself, the preferred viscosity is one that will form
an at least
~s temporarily adherent liquid film, on a substrate coated with the working
composition, that
when dried will contain the preferred amounts--of non-vola#ile lubricant
constituents:
These preferred amounts vary widely with the exact choice of substrate and
cold
working conditions, but can readily be determined with minimal experimentation
by those
skilled in the art. The numerical preferences stated below are believed to be
correct for
zo most uses but should be regarded only as general guidelines for exceptional
uses.
In a working aqueous composition according to the invention, the combined con-
centrations of components (A) and (E), if the latter is present, or the
concentration of
component (A) if component (E) is not present, preferably is at least, with
increasing
preference in the order given, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, or 7.5 %.
There is no
zs known technical disadvantage, although there is obviously a possible
economic
disadvantage, to a concentration of component (A) of at least as much as 15 %.
The molecules of component (A) preferably have a chemical structure that can
be produced by condensing ethylene oxide with primary, most preferably
straight chain,
aliphatic monoalcohols that have, with increasing preference in the order
given, at least
so 25, 30, 35, 40, 43, 46 or 48 carbon atoms per molecule and independently,
with
increasing preference in the order given, not more than 65, 60, 57, 55, 52, or
51 carbon
atoms per molecule. Independently, these actual or hypothetical precursor
aliphatic
alcohols preferably have no functional groups other than the single -OH
moiety, and,
optionally but less preferably, also fluora and/or chloro moieties.
Independently, it is
35 preferred that the molecules of ethoxylated alcohols used in a composition
according
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WO 00/12655 PCTNS98/17345
to this invention contain, with increasing preference in the order given, at
least 20, 30,
35, 40, 43, 47, or 49 %, and independently preferably contain, with increasing
pref
erence in the order given, not more than 80, 70, 62, 57, 54, or 51 %, of their
total mass
in the oxyethylene units.
s In component (B), the anions preferably contain a number of carbon atoms in
each anion that is at least, with increasing preference in the order given,
10, 12, 14, 16,
or 18 and independently preferably is not more than, with increasing
preference in the
order given, 40, 35, 30, 26, 24, 22, or 20. The number of carbon atoms over
the whole
of component (B) will be averaged and therefore will not necessarily be
integral, as will
the number for each.molecule; but the.preferences for the.average.are.the same-
as for-
the individual anions within the number of significant figures stated.
Independently, salts
of saturated acids and those without functional groups other than the
necessary carbox-
ylate group are preferred, to minimize susceptibility to degradation upon
storage in con-
tact with the ambient natural atmosphere. For both economy and good
performance,
~s sans of commercial stearic acid, which usually contains at least a few
percent of palmitic
acid also, and may contain small amounts of other fatty acids, is most
preferred.
The rations in component (B) may be sodium, lithium, or calcium. The rations
more preferably are lithium andlor calcium and still more preferably are a
mixture of both
lithium and calcium in a molar ratio for lithium to calcium that is at least,
with increasing
zo preference in the order given, 0.2:1.0, 0.4:1.0, 0.6:1.0, 0.70:1.0,
0.80:1.0, 0.85:1.0,
0.90:1.0, or 0.95:1.0 and independently preferably is not more than, with
increasing
preference in the order given, 5:1.0, 3.0:1.0, 2.5:1.0, 2.0:1.0, 1.7:1.0,
1.4:1.0, or 1.1:1Ø
Independently, total component (B) preferably has a ratio to a total of
components (A)
and (E), if the latter optional component is present, or to component (A) if
component
25 (E) is not present, that is at least, with increasing preference in the
order given, 0.02:1.0,
0.04:1.0, 0.06:1.0, 0.08:1.0, 0.10:1.0, 0.12:1.0, or 0.14:1.0 and
independently preferably
is not more than, with increasing preference in the order given, 2.0:1.0,
1.5:1.0, 1.0:1.0,
0.8:1.0, 0.6:1.0, 0.4:1.0, or 0.2:1Ø
Component (C) is preferably selected from the group consisting of metaboric
so acid (i.e., HB02), orthoboric acid (H3B03), and alkali metal and ammonium
salts of met-
aboric and orthoboric acids and of the hypothetical tetraboric acid (i.e.,
H2B40~). More
preferably, component (C) is selected from orthoboric acid, salts of
tetraboric acid, and
salts of orthoboric acid; most preferably a mixture of orthoboric acid and
tetraborate
anions and, optionally, orthoborate anions is used, and in such a mixture the
molar ratio
ss of the total of orthoborate anions (if any) and of orthoboric acid to
tetraborate anions
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preferably is, with increasing preference in the order given, at least
1.0:1.0, 2.0:1.0,
3.0:1.0, 3.5:1.0, 4.0:1.0, 4.5:1.0, 5.0:1.0, 5.4:1.0, 5.7:1.0, 5.9:1.0, or
6.0:1.0 and inde-
pendently preferably is, with increasing preference in the order given, not
more than
20:1.0, 15:1.0, 12:1.0, 10:1.0, 9:1.0, 8.0:1.0, 7.5:1.0, 7.0:1.0, 6.7:1.0,
6.4:1.0, or 6.1:1Ø
s Independently, the ratio of the total amount of boron in component (C) to
the total of
component (E), if any, and of component (A) preferably is, with increasing
preference
in the order given, not less than 0.002:1.0, 0.005:1.0, 0.007:1.0, 0.009:1.0,
0.011:1.0,
0.013:1.0, 0.015:1.0, 0.017:1.0, 0.019:1.0, 0.021:1.0, 0.023:1.0, 0.027:1.0,
0.030:1.0,
0.035:1.0, 0.040:1.0, 0.045:1.0, or 0.050:1.0 and independently preferably is
not more
o than 1.0:1.0, 0.5:1.0, 0.3:1.0, 0.20:1.0, 0.17:1.0, 0.14:1.0, 0.11:1.0,
0.100:1.0, 0.090:1.0,
0.085:1.0, 0.080:1.0, 0.075:1.0, 0.070:1.0, 0.065:1.0, 0.060:1.0, 0.055:1.0,
or 0.052:1Ø
The presence in a composition according to the invention of optional
alkoxylated
triglyceride component (D) is preferred. When component (D) is present in a
composi
tion according to the invention, the amount of it preferably has a ratio to
the total amount
,5 of components (A) and (E) in the same composition that is at least, with
increasing pref
erence in the order given, 0.05:1.0, 0.10:1.0, 0.20:1.0, 0.30:1.0, 0.35:1.0,
or 0.38:1.0 and
independently preferably is not more than, with increasing preference in the
order given,
2.0:1.0, 1.0:1.0, 0.90:1.0, 0.70:1.0, 0.60:1.0, 0.55:1.0, 0.50:1.0, or
0.45:1Ø
Independently of its concentration, component (D) is preferably, at least for
rea-
zo sons of economy, selected from materials made by condensing alkylene oxide
mole-
cules with one of the naturally available fat or oil triglyceride molecule
mixtures, most
preferably with castor oil; independently, only ethylene oxide preferably is
condensed
with the triglyceride used to make component (D), and the amount of ethylene
oxide
preferably is such as to result in a hydrophile-lipophile balance for
component (D) as a
Zs whole that is at least, with increasing preference in the order given, 4,
6, 8, 10.0, 10.5,
11.0, or 11.5 and independently preferably is not more than, with increasing
preference
in the order given, 20, 18, 16, 14, 13.0, 12.5, or 12Ø
The presence in a composition according to the invention of optional ionomer
component (E) is also preferred. When component (E) is present, the amount of
it pres-
ao ent preferably has a ratio to the amount of component (A) in the same
composition that
is at least, with increasing preference in the order given, 0.1:1.0, 0.3:1.0,
0.5:1.0, 0.7:1.0,
0.9:1.0, or 1.05:1.0 and independently preferably is not more than, with
increasing
preference in the order given, 5:1.0, 3:1.0, 2.0:1.0, 1.8:1.0, 1.6:1.0,
1.4:1.0, or 1.2:1Ø
Independently of the amount of component (E), an alkene molecule polymerized
35 to make a molecule of component (E) preferably is selected from the group
consisting
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of ethene (more commonly called "ethylene"), propane, 2-methyl propane, and 1-
and
2-butanes; more preferably it is ethane or propane, most preferably ethane.
For the un-
saturated organic acid comonomer to make component (E), acrylic acid is most
pre-
ferred, and methacrylic acid and other homologs of acrylic acid, i.e.,
molecules differing
s from acrylic acid by the addition of one or more -CH2- groups, with not more
than six,
preferably not more than four, carbon atoms per molecule are next most
preferred. The
fraction of.the mass of the polymer made-up of alkene residues preferabfy-is~
within-
creasing preference in the order given, not less than 1, 2, 4, 15, 30, 40, 50,
55, 60, 65,
70, 75, 80, or 84 %; independently, the fraction of the mass of the polymer
made up of
,o alkene residues preferably is, with increasing preference in the order
given, not more
than 99, 97, 95, 92, 90, 89, 87, or 86 %. Independently, the fraction of the
mass of the
polymer made up of acrylic acid and/or acrylate residues preferably is, with
increasing
preference in the order given, not less than 1, 2, 4, 6, 8, 10, 11, 12, 13, or
14 %; inde-
pendently, the fraction of the mass of the polymer made up of acrylic acid
andlor
,s acrylate residues preferably is, with increasing preference in the order
given, not more
than 50, 40, 35, 30, 25, 20, 18, or 16 %.
Normally, commercially available polymers in latex form are preferred for com-
ponent (E); a variety of such commercial products are available. Such products
normal-
ly contain small amounts of surfactants for stabilizing the polymers in
suspension; these
surfactants normallyhavev o adverse effect owcompositions according to this
invention:
The counterions for the neutralized acrylic acid units in the polymers of
component (E) are preferably selected from the group consisting of magnesium,
calcium, zinc, and alkali metal ions; more preferably zinc, magnesium, and
calcium;
most preferably calcium.
25 Aqueous compositions containing ethoxylated alcohols sometimes stain or
other-
wise discolor metal surfaces exposed to them. If this is undesirable, it can
generally be
prevented by including in the working composition a suitable corrosion
inhibitor as an
optional component (F). A particularly preferred component (F) comprises, more
pref-
erably consists essentially of, or still more preferably consists of:
so (F.1) a primary inhibitor component selected from the group consisting of
non-sulfur-
containing organic azole compounds, preferably organic triazoles, more prefer-
ably benzotriazole andlor tolyltriazole; and
(F.2) a secondary inhibitor component selected from the group consisting of
organic
azoles that also contain mercapto moieties, preferably mercaptobenzothiazole
s5 or mercaptobenzimidazole.
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With this preferred corrosion inhibitor, the concentration of component (F.1)
in
a working aqueous liquid composition according to this invention preferably
is, with in-
creasing preference in the order given, not less than 0.10, 0.20, 0.30, 0.40,
0.50, 0.60,
0.70, 0.80, 0.90, or 1.00 part per thousand (hereinafter usually abbreviated
"ppt") of the
s total composition and independently, primarily for reasons of economy,
preferably is,
with increasing preference in the order given, not more than 20, 10, 5.0, 4.0,
3.0, or 2.0
ppt. For a concentrate, these concentrations should be increased to correspond
to the
expected dilution factor when the concentrate is used to make a working
composition.
Independently; as already noted above; it is preferred for component (F.1 ) to
be
o selected from benzotriazole and tolyltriazole, and in fact a mixture of
these two is more
preferred than either of them alone. The amount of each of benzotriazole and
tolyltriaz
ole in a composition according to the invention, expressed as a percentage of
the total
of component (F.1), preferably is, with increasing preference in the order
given,
independently for each of these iwo triazoles, not less than 5, 10, 15, 20,
25, 30, 35, 38,
,s 41, 43, 45, 47, 48, or 49 % and independently preferably is, with
increasing preference
in the order given, not more than 95, 90, 85, 80, 75, 70, 65, 62, 59, 57, 55,
53, 52, or 51
%. These ratios, unlike the concentration preferences stated above, apply
exactly to
concentrates as well as to working compositions.
When present, the concentration of component (F.2) in a composition according
zo to this invention preferably has a ratio to the concentration of component
(F.1) in the
same composition that preferably is, with increasing preference in the order
given, not
less than 0.001:1, 0.002:1, 0.004:1, 0.007:1, 0.015:1.0, 0.030:1.0, 0.040:1.0,
0.045:1.0,
0.050:1.0, 0.053:1.0, 0.056:1.0, or 0.059:1.0 and independently preferably is,
with
increasing preference in the order given, not more than 2:1, 1:1, 0.5:1,
0.3:1, 0.2:1,
zs 0.15:'f.0, -0.1-0:1.0, -0.080:1-.00; -0:070:1-.00; 0.067:T00; 0.065:1-.00; -
0.063:'f.00; or
0.061:1.00.
Optional components (G) and (H) as described above are not generally needed
in a composition according to the invention and therefore are preferably
omitted in such
instances. However, in unusual instances, a wetting agent may be needed to
promote
so uniform application of a liquid composition according to the invention to a
substrate,
and/or an antifoam agent may be needed to prevent excessive foaming during
some
part of a process. In any such instances, suitable material for these purposes
can be
readily selected by those skilled in the art.
The pH of working compositions according to this invention preferably is, with
in-
ns creasing preference in the order given, not less than 3, 4, 5, 6, 7, 7.3,
7.5, 7.7, 7.8, 7.9,
9
CA 02342359 2001-02-28
WO 00/12655 PCT/US98/17345
or 8.0 and independently preferably is, with increasing preference in the
order given, not
more than 11, 10, 9.7, 9.4, 9.1, 9.0, 8.9, 8.8, 8.7, 8.6, or 8.5. If necessary
to obtain a pH
within the preferred range, alkaline or acid materials may be added to the
other ingredi-
ents of a composition according to the invention as specified above. Normally,
addition
s of alkaline materials to the other ingredients specified above will be
needed in order to
obtain the most preferred pH values for a working composition according to the
inven-
tion, and sodium hydroxide is nom~ally preferred as the alkaline material
because it is
effective and relatively inexpensive. However, other soluble alkali and
alkaline earth
metal hydroxides, ammonia, mono-, di- and tri-ethanol amines, and dimethyl-
and dieth-
o yl-ethanol amines are also suitable for raising the pH if needed to bring it
into a preferred
range.
The specific areal density (also often called "add-on weight [or mass]") of a
com-
position according to this invention, after application from a liquid
composition to the
metal surface and drying into place on the liquid-coated treated surface of
the solid con-
,5 stituents of the liquid coating thus applied, preferably is, with
increasing preference in
the order given, at least 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0,
5.5, 6.0, 6.5, or 7.0
grams of dried lubricating composition per square meter of surface (this unit
of areal
density or add-on weight being hereinafter usually abbreviated as "g/m2").
Substantially
larger amounts than this may be used without any technical disadvantage, but
the spe-
zo cific areal density independently preferably is, with increasing preference
in the order
given, not more than 100, 80, 75, 70, 65, 60, 55, 50, 45, 40, or 35 glm2, and
if maximum
economy is desired more preferably is, with increasing preference in the order
given, not
more than 30, 25, 20, 15, 10, or 9.0 g/mz.
Generally, in order to speed the drying process and possibly to promote some
z5 favorable chemical interaction among the nonvolatile components of a
working composi-
tion according to this invention, it is preferred to expose the liquid coating
formed in a
process according to this invention to heat in the course of, or after, drying
this liquid
coating. The maximum temperature to which the coating is exposed preferably
is, with
increasing preference in the order given, not less than 30, 40, 50, 60, or 70
°C and inde-
so pendently preferably is, with increasing preference in the order given, not
more than
180, 160, 150, 140, 130, or 120 °C. Independently, the melting point of
component (A)
in the composition should not be exceeded; for the most preferred examples of
compon-
ent (A), the melting point is about 115° C. The time during which the
casting is exposed
to the maximum temperature used to dry it preferably is, with increasing
preference in
35 the order given, not less than 3, 5, 7, 10, 12, 14, 16, 17, 18, 19, or 20
minutes (hereinaf-
CA 02342359 2001-02-28
WO 00/12655 PCT/US98/17345
ter usually abbreviated "min") and independently preferably is, with
increasing prefer-
ence in the order given, not more than 90, 80, 70, 60, 55, 50, or 45 min.
However, the
process may also be satisfactorily applied with only drying in the ambient
atmosphere,
without any elevated temperature, particularly if the working treatment
composition is
s applied while at a temperature that is at least, with increasing preference
in the order
given, 50, 60, 68, or 72 °C.
At least for reasons of economy, a lubricant composition according to the
inven-
tion preferably is used on a metal substrate that does not have any
intermediate coating.
However, a composition according to the invention can also be used over an
underlying
,o conversion coating layer formed on the metal substrate. The conversion
coating may
be formed by methods known per se in the art.
The practice of this invention may be further appreciated by consideration of
the
following, non-limiting, working examples, and the benefits of the invention
may be fur-
ther appreciated by reference to the comparison examples.
~5 EXAMPLE AND COMPARISON EXAMPLE 1
In this group, the substrates were cylindrical steel tubes with outside
diameters
ranging from 5 to 25 centimeters and wall thicknesses ranging from 0.6 to 3
centimeters.
The tubes were made of one of the alloys having American Society for Testing
and
Materials type numbers 1026, ST52C, and 4130 and were reduced in cross-
sectional
2o area during drawing by percentages ranging from 2 to 35 %. A commercial
drawing
operation was used for the testing, enabling the testing of a very large total
surface area
of tubes with a mass of over 350 tonnes.
Concentrate Example and Comparison Example 1 had the compositions shown
in Table 1 below, identical in ingredients other than water except for the
presence of lithi-
is um stearate in the Example according to the invention. The ethoxylated
alcohol used
was obtained commercially from Petrolite Corporation under their name
UNITHOXT""
750, which is reported by its supplier to consist of products of reaction
between ethylene
oxide and straight chain primary alcohols with an average carbon number of 50,
in rela-
tive amounts such that about 50 % of the mass of the products consists of
poly(oxyethyl-
so ene) residues from the ethylene oxide molecules reacted and the hydroxyl
groups pres-
ent in the reacted alcohol molecules, the remainder of the product mass being
alkyl
moieties derived from the alcohol moieties reacted.
The tubes were conventionally cleaned and pickled, then coated with a working
composition consisting of a solution in water containing from about 20 to
about 33 % of
as one of the concentrates shown in Table 1. The coated tubes were then dried
and baked
11
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WO OO/I2655 PCT/US98/17345
Table 1
Ingredient Concentration in Grams
Per Liter of Ingredient
in:
Comparison Example Example Concentrate
Concentrate 1 1
Ethoxylated alcohol96 96
Boric acid 24 24
Sodium tetraborate 24 24
decahydrate
Sodium hydroxide 3.6 3.6
2-Mercaptobenzimidazole0.3 0.3
Tolyltriazole 2.5 2.5
Benzotriazole 2.5 2.5
Lithium stearate 0 14
Water Balance Balance
for 30 minutes in a tube dryer maintained at 104 to 116 °C before being
drawn. After be-
ing drawn, the tubes were examined for surtace quality according to normal
commercial
standards. The rejection rate was about 10 % overall for tubes lubricated with
dried resi-
dues of working compositions made from Comparison Example Concentrate 1. For
s tubes lubricated with dried residues of working compositions made from
Example Con-
centrate 1, the rejection rate was only about 0.5 %.
EXAMPLE AND COMPARISON EXAMPLE GROUP 2
In this group, the substrates were aluminum slugs that, after being
lubricated, are
extruded into automobile air bag propellant canisters. Four working
compositions were
prepared with the ingredients shown in Table 2 below.
The substrate slugs were conventionally cleaned according to a PARCO~
Cleaner 703 process, directions and chemicals for which are commercially
available
from the Henkel Surface Technologies Div. of Henkel Corp., Madison Heights,
MI, then
were conventionally deoxidized in 20 % by mass nitric acid solution in water,
and then
is were coated with one of the working compositions listed in Table 2, or with
a slightly
diluted working composition made from one of those listed in Table 2, in order
to obtain
a dry coating weight in a range from 7 to 9 grams per square meter of surface
coated.
The working compositions were maintained at 74 °C during use, and after
coating the
slugs were allowed to dry spontaneously in the ambient natural atmosphere
before
2o being extruded, all under the same conditions. The quality of extrusion was
determined
by examining the inside and outside surfaces of the extruded canisters for
scratches.
12
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WO 00/12655 PCT/US98/17345
Table 2
Ingredient Percent by
Weight of
Ingredient
in:
Comparison Example Example 2.2 Example
Example 2 2.1 2.3
Sodium 0.65 0.65 0.70 0.70
Hydroxide
Boric Acid 1.7 1.7 2.1 2.1
Borax 0.84 0.84 2.1 2.1
DK 100TM 0 0 0.03 0
defoamer
ZONYLTM 0 0 0.14 0
FSN 100
surfactant
UNITHOXTM 27 27 15.3 11
D300 latex
ACquaTM 25 25 21.4 21
250
ionomer
Lithium 0 1.6 0.7 0.7
stearate
Calcium 0 0 1.4 1.4
stearate
ETHOXTM 0 0 0 2.8
C030
surfactant
Water Balance Balance Balance Balance
NOTES FOR TABLE 2
DK 1 OOTM defoamer was obtained commercially from Genese Polymers Core. and
was reported
by its supplier to consist primarily of aliphatic hydrocarbons; ZONYLTM FSN
100 surfactant was
obtained commercially from Du Pont and described by its suppler as a
fluorinated nonionic
surfactant; UNITHOXTM D300 latex was commercially supplied by Petrolite Corp.,
Tulsa, Okla-
homa, USA, and is reported by its supplier to be a dispersion in water of a
condensation product
of aliphatic monohydroxy primary alcohols with an average number of 50 carbon
atoms per mol-
ecule with an approximately equal mass of ethylene oxide, with a solids
content of 23:5- t 0.5 %;
ACquaTM 250 ionomer was obtained commercially from Allied Signal Corp. and was
reported
by its supplier to contain 25 % solids of a calcium neutralized copolymer of
acrylic acid and
ethylene in which about 15 % of the mass of the copolymer is made up of
residues of acrylic
acid; ETHOXTM C030 surfactant was obtained commercially from Ethox Corp. and
was reported
by its supplier to consist of ethoxylated castor oil with a hydrophile-
lipophile balance of 11.8;
and "borax" means Na2B40~ ~ 10 H20.
Results are shown in Table 3.
13
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WO 00/12655 PCT/US98/17345
Table 3
Percent Comparison Example Example 2.2 Example
of 2.1 2.3
Substrates Example 2
Showing
Scratches
When
Lubricated
with:
Scratches 90 50 10 0
On
Inside
Scratches 80 50 0 10
On
Outside
The examples according to the invention clearly give better lubrication
perform-
ance than the comparison example.
14
