U.S. patent number 3,661,622 [Application Number 05/020,038] was granted by the patent office on 1972-05-09 for method of improving resistance to corrosion of metal surfaces and resultant article.
This patent grant is currently assigned to Continental Oil Company. Invention is credited to Lynn C. Rogers.
United States Patent |
3,661,622 |
Rogers |
May 9, 1972 |
METHOD OF IMPROVING RESISTANCE TO CORROSION OF METAL SURFACES AND
RESULTANT ARTICLE
Abstract
A method of improving resistance to corrosion of metal surfaces
is disclosed, wherein said method comprises: a. applying to the
metal surface a composition comprising (1) a major amount (e.g. at
least 75 weight percent) of a thixotropic, grease-like composition
consisting essentially of a non-volatile diluent, an oil-soluble
dispersing agent and an alkaline earth metal carbonate and (2) a
minor amount (e.g. 0.1 to 25 weight percent) of a polymer, and b.
applying to the coated metal surface a conventional paint. An
important feature is the use of the composition described in step
(a) as a primer coating.
Inventors: |
Rogers; Lynn C. (Ponca City,
OK) |
Assignee: |
Continental Oil Company (Ponca
City, OK)
|
Family
ID: |
21796396 |
Appl.
No.: |
05/020,038 |
Filed: |
March 16, 1970 |
Current U.S.
Class: |
428/467;
252/389.61; 427/410; 428/413; 428/424.4; 428/424.8; 428/483;
428/497; 428/500; 428/501; 524/427; 524/556; 524/563; 524/567;
524/579; 524/583; 524/586; 428/484.1; 428/471 |
Current CPC
Class: |
C10M
1/08 (20130101); C09D 5/08 (20130101); C10M
2205/16 (20130101); C10M 2207/402 (20130101); C10N
2050/02 (20130101); Y10T 428/31576 (20150401); Y10T
428/31801 (20150401); C10M 2205/024 (20130101); C10M
2207/34 (20130101); C10M 2219/082 (20130101); C10M
2213/02 (20130101); C10N 2020/01 (20200501); Y10T
428/31859 (20150401); C10M 2207/125 (20130101); C10M
2207/129 (20130101); C10N 2030/12 (20130101); C10M
2201/02 (20130101); B05D 7/16 (20130101); C10M
2209/084 (20130101); C10M 2209/04 (20130101); Y10T
428/31714 (20150401); C10M 2207/40 (20130101); C10M
2205/022 (20130101); C10M 2207/282 (20130101); C10M
2211/06 (20130101); C10M 2205/00 (20130101); Y10T
428/31797 (20150401); C10M 2219/046 (20130101); Y10T
428/31844 (20150401); C10M 2201/062 (20130101); C10M
2219/044 (20130101); C10M 2205/17 (20130101); C10M
2207/021 (20130101); C10M 2207/16 (20130101); C10M
2209/06 (20130101); C10M 2207/18 (20130101); C10M
2205/14 (20130101); Y10T 428/31511 (20150401); C10N
2050/10 (20130101); B05D 7/54 (20130101); C10M
2207/046 (20130101); C10M 2213/062 (20130101); C10M
2209/104 (20130101); C10M 2209/062 (20130101); C10N
2010/00 (20130101); Y10T 428/31587 (20150401); C10M
2205/026 (20130101); C10M 2207/404 (20130101); C10N
2010/04 (20130101); C10N 2070/00 (20130101); Y10T
428/31855 (20150401) |
Current International
Class: |
B05D
7/14 (20060101); B05D 7/16 (20060101); C09D
5/08 (20060101); B44d 001/14 (); B32b 015/04 () |
Field of
Search: |
;117/75,89,92,72,134,132R,132C,219,224,DIG.5
;252/388,389,33,39 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Martin; William D.
Assistant Examiner: Husack; Ralph
Claims
The invention having thus been described, what is claimed and
desired to be secured by Letters Patent is:
1. A method of improving resistance to corrosion of metal surfaces
wherein the method comprises:
A. applying to the metal surface a primer composition which
comprises, in parts by weight:
1. from about 75 to about 99.9 parts of a thixotropic, grease-like
composition consisting essentially of:
i. from about 2 to about 80 parts nonvolatile diluent selected from
the group consisting of mineral lubricating oils, synthetic
lubricating oils, and petroleum waxes,
ii. from about 5 to about 55 parts oil-soluble dispersing
agent,
iii. from about 1 to about 45 parts alkaline earth metal carbonate,
said grease-like composition being characterized further in that it
has an acetic base number of at least 50, does not flow at
210.degree. F, and has a dropping point of at least 480.degree.
F
2. from about 0.1 to about 25 parts polymer, said polymer being
characterized as having a crystallinity of less than 50 percent, a
molecular weight in the range of from about 3,000 to about 1
million and a high solubility in predominantly aliphatic
hydrocarbon solvents,
B. allowing the coated metal surface to become substantially free
of any volatile solvent which may be present, and
C. applying to the coated metal surface a conventional paint
wherein said paint adheres to said primer.
2. The method of claim 1 wherein the oil-soluble dispersing agent
is a sulfonic acid, or a metal salt thereof.
3. The method of claim 2 wherein the alkaline earth metal carbonate
is calcium carbonate.
4. The method of claim 3 wherein the polymer is selected from the
group consisting of polyterpenes, amorphous polypropylenes, low
molecular weight polyethylenes, and ethylene-vinyl acetate
copolymers.
5. The method of claim 4 wherein the conventional paint is selected
from the group consisting of two-component amine cured epoxy,
two-component urethane, alkyd enamel, phenolic enamel, acrylic
water emulsion, and vinyl.
6. The method of claim 5 wherein the polymer is a polyterpene.
7. The method of claim 5 wherein the polymer is an amorphous
polypropylene.
8. The method of claim 5 wherein the polymer is a low molecular
weight polyethylene.
9. The method of claim 5 wherein the polymer is an ethylene-vinyl
acetate copolymer.
10. A method of improving resistance to corrosion of metal
surfaces, wherein the method comprises:
A. applying to the metal surface a primer composition which
comprises, in parts by weight:
1. from about 90 to about 99.8 parts of a thixotropic, grease-like
composition consisting essentially of:
i. from about 20 to about 70 parts nonvolatile diluent selected
from the group consisting of mineral lubricating oils, synthetic
lubricating oils and petroleum waxes,
ii. from about 6 to about 35 parts calcium salt of an oil soluble
sulfonic acid,
iii. from about 5 to about 30 parts calcium carbonate, said
grease-like composition being characterized further in that it has
an acetic base number of at least 50, does not flow at 210.degree.
F, and has a dropping point of at least 480.degree. F,
2. from about 0.2 to about 10 parts polymer, said polymer being
characterized as having a crystallinity of less than 50 percent, a
molecular weight in the range of from about 3,000 to about 1
million and a high solubility in predominantly aliphatic
hydrocarbon solvents,
B. allowing the coated metal surface to become substantially free
of any volatile solvent which may be present, and
C. applying to the coated metal surface a conventional paint
wherein said paint adheres to said primer.
11. The method of claim 10 wherein the nonvolatile diluent is a
mineral lubricating oil.
12. The method of claim 11 wherein the polymer is selected from the
group consisting of polyterpenes, amorphous polypropylenes, low
molecular weight polyethylenes, and ethylene-vinyl acetate
copolymers.
13. The method of claim 12 wherein the polymer is a
polyterpene.
14. The method of claim 12 wherein the polymer is an amorphous
polypropylene.
15. The method of claim 12 wherein the polymer is a low molecular
weight polyethylene.
16. The method of claim 12 wherein the polymer is an ethylene-vinyl
acetate copolymer.
17. The method of claim 12 wherein the conventional paint is
selected from the group consisting of two-component amine cured
epoxy, two-component urethane, alkyd enamel, phenolic enamel,
acrylic water emulsion, and vinyl.
18. The method of claim 17 wherein the polymer is a
polyterpene.
19. The method of claim 17 wherein the polymer is an amorphous
polypropylene.
20. The method of claim 17 wherein the polymer is a low molecular
weight polyethylene.
21. The method of claim 17 wherein the polymer is an ethylene-vinyl
acetate copolymer.
22. A method of coating a substrate which comprises:
A. applying to the substrate a primer composition which comprises
in parts by weight:
1. from about 75 to about 99.9 parts of a thixotropic, grease-like
composition consisting essentially of:
i. from about 2 to about 80 parts nonvolatile diluent selected from
the group consisting of mineral lubricating oils, synthetic
lubricating oils, and petroleum waxes,
ii. from about 5 to about 55 parts oil-soluble dispersing
agent,
iii. from about 1 to about 45 parts alkaline earth metal carbonate,
said grease-like composition being characterized further in that it
has an acetic base number of at least 50, does not flow at
210.degree. F, and has a dropping point of at least 480.degree.
F,
2. from about 0.1 to about 25 parts polymer, said polymer being
characterized as having a crystallinity of less than 50 percent, a
molecular weight in the range of from about 3,000 to about 1
million and a high solubility in predominantly aliphatic
hydrocarbon solvents,
B. allowing the coated substrate to become substantially free of
any volatile solvent which may be present, and
C. applying to the coated substrate a conventional paint wherein
said paint adheres to said primer.
23. A metal article, one surface of which has been coated with a
primer composition and a conventional paint adhered to said primer,
said primer composition comprising in parts by weight:
1. from about 75 to about 99.9 parts of a thixotropic, grease-like
composition consisting essentially of:
i. from about 2 to about 80 parts nonvolatile diluent selected from
the group consisting of mineral lubricating oils, synthetic
lubricating oils, and petroleum waxes,
ii. from about 5 to about 55 parts oil-soluble dispersing
agent,
iii. from about 1 to about 45 parts alkaline earth metal carbonate,
said composition being characterized further in that it has an
acetic base number of at least 50, does not flow at 210.degree. F,
and has a dropping point of at least 480.degree. F,
2. from about 0.1 to about 25 parts polymer, said polymer being
characterized as having a crystallinity of less than 50 percent, a
molecular weight in the range of from about 3,000 to about 1
million and a high solubility in predominantly aliphatic
hydrocarbon solvents.
Description
RELATED APPLICATIONS
The following applications have the same assignee as the present
application:
Ser. No. 727,719, filed May 8, 1968, now abandoned concerns a
method of preparing the thixotropic, grease-like composition.
Ser. No. 729,875, filed May 8, 1968, now U.S. Pat. No. 3,565,672
concerns the use of a thixotropic, grease-like composition as a
primer for paints.
The teachings of these applications will be discussed more
completely hereinafter.
Ser. No. 20,039, filed the same day as the present application,
concerns grease compositions comprising a major amount of a
thixotropic, grease-like composition and a minor amount of a
polymer.
BACKGROUND
The use of surface coatings (e.g. paint) to protect metals from
corrosion is well-known. Usually, the corrosion protection is due
more to the use of particular primers than to the paint itself.
While most of the surface coatings (including primers) of the prior
art afford a satisfactory degree of protection, they have the
disadvantage that the surface requires a relatively high degree of
preparation prior to the application of the primer. The high cost
of the labor used in preparing the surface makes the total job of
coating the metal surface quite expensive.
It is thus apparent that it would be highly desirable to have a
primer which affords good corrosion protection and yet requires
only a minimum amount of preparation of the metal surface prior to
application. Application Ser. No. 729,875, referred to in the
foregoing, teaches the use of a thixotropic, grease-like
composition as a primer which meets these requirements. My
invention provides a composition which gives improved results as a
primer. Briefly stated, the composition of my invention comprises
(1) a major amount of a thixotropic, grease-like composition and a
minor amount (e.g. 0.1 to 25 weight percent) of a polymer having
certain characteristics. The use of such a composition as a primer
results in a film which is harder, tougher and less tacky than the
use of the composition of application Ser. No. 729,875.
PRIOR ART
The most pertinent prior art is believed to be the following:
U.S. Pat. No. 3,384,586 teaches the addition of a thixotropic,
grease-like composition to a polymer. More specifically, this
patent teaches a composition comprising a major amount of a polymer
and a minor amount of the thixotropic, grease-like composition.
U.S. Pat. No. 3,372,114 teaches that gelled materials useful as a
lubricant additive in greases are prepared by contacting (A) a
fluid mineral oil solution of a carbonated, basic complex of an
alkaline earth metal and an organic carboxylic or sulfonic acid,
salt thereof, or carboxylic ester containing at least 12 aliphatic
carbon atoms, the complex being characterized by a metal ratio of
at least 4:5, with (B) oxygen at a temperature of about 150.degree.
C. to about 300.degree. C. The patent further teaches that in some
instances the product is a grease and that small compatible
hydrocarbon resins can be added to the product.
Neither of these patents contain any teachings that the
compositions taught therein can be used as a primer for
conventional paints.
Application Ser. No. 729,875 has been discussed in the section in
the immediate foregoing.
BRIEF SUMMARY OF THE INVENTION
Briefly, the present invention concerns a method of improving
resistance to corrosion of metal surfaces wherein the method
comprises:
a. applying to the metal surface a composition comprising (1) a
major amount (at least 75 weight percent) of a thixotropic,
grease-like composition consisting essentially of a nonvolatile
diluent, an oil-soluble dispersing agent and an alkaline earth
metal carbonate and (2) a minor amount (0.1 to 25 weight percent)
of a polymer, which, preferably, has the following properties:
i. a low degree of crystallinity,
ii. a molecular weight in the range of from about 3,000 to about 1
million, and
iii. a high solubility in predominantly aliphatic hydrocarbon
solvents,
b. applying to the coated metal surface a conventional paint.
Preferably, the composition applied in step (a) should be
substantially free of volatile solvents before applying the paint
in step (b).
In another aspect, the present invention concerns a metal article
having improved resistance to corrosion, said metal article having
the exterior surface coated with the composition, described in the
foregoing, as the primer coat and a conventional paint as the
external coat.
In still another aspect, the present invention concerns the use of
the composition, described in the foregoing, as a primer coating
when used in conjunction with conventional paints on any of the
surfaces normally coated by conventional paints.
DETAILED DESCRIPTION
The composition used in my invention comprises a major amount of a
thixotropic, grease-like composition and a minor amount of a
polymer having certain properties.
The thixotropic, grease-like composition consists essentially of
the following materials in the amounts stated:
Parts by Weight
__________________________________________________________________________
Suitable Preferred
__________________________________________________________________________
Nonvolatile diluent* 2-80 20-70 Oil-soluble dispersing agent* 5-55
6-35 Alkaline earth metal carbonate* 1-45 5-30
__________________________________________________________________________
*The specific nature of these materials will be described
hereinafter in connection with the preparation of this
composition.
The thixotropic, grease-like composition has the following
properties:
An acetic base number of at least 50, preferably at least 135,
Dropping point, ASTM, of at least 480.degree. F., Does not flow at
210.degree. F.*(*Another way of stating this property is that the
composition has no apparent (i.e. cannot be measured) viscosity at
210.degree. F.)
In order to described more fully the nature of the thixotropic,
grease-like composition we will now describe methods of preparing
the composition. In so doing we will describe the nature of the
materials present in the composition.
Basically, there are two general methods of preparing the
composition. The first method is called simply a "two-step" method.
According to this method, a colloidal dispersion of alkaline earth
metal carbonate is formed first. The dispersion is then treated,
preferably, with a small amount of water in the presence of a small
amount of alcohol. The second method is called simply a "one-step "
method. According to this method, an admixture is formed of
oil-soluble dispersing agent, nonvolatile diluent, alkaline earth
metal compound, alcohol, and water. After treating the admixture
with CO.sub.2, the volatile materials are removed by distillation.
The two-step method will be described in detail first.
TWO-STEP METHOD OF PREPARATION
Starting Materials
The charge (or starting) material for this method of preparing the
thixotropic, grease-like composition is a colloidal dispersion of
an alkaline earth metal carbonate in a suitable diluent and having
an acetic base number of at least 50. The term "alkaline earth
metal" as used herein refers only to those of this group which are
more commonly available, namely, magnesium, calcium, strontium and
barium. Of these, calcium and barium are more suitable, with
calcium being preferred.
While we have used the term alkaline earth metal carbonate it may
be well to mention that, although carbonate is the predominant
anion, traces of other anions, e.g. hydroxide, oxide, and alkoxide,
can be present. This is due to the fact that many processes of
preparing dispersions of alkaline earth metal carbonates prepare
the carbonate by carbonation of an alkaline earth metal hydroxide,
oxide or alkoxide.
Many processes are known for preparing colloidal dispersions of
alkaline earth metal carbonates. Also, several processes are known
for preparing colloidal dispersions of alkaline earth metal
carbonates, wherein the metal carbonate is formed in situ in the
presence of the dispersing agent. It is characteristic of the
products prepared by the in situ method that they have a uniform
and small (i.e. 0.25 micron or less, and usually 0.10 micron or
less) particle size.
The following U.S. patents are concerned with the preparation of
colloidal dispersions, wherein the alkaline earth metal compound is
formed in situ: U.S. Pat. No. 3,150,089, to Mack W. Hunt, which
issued Sept. 22, 1964 and is entitled "Highly Basic
Magnesium-Containing Additive Agent"; U.S. Pat. No. 3,150,088, to
Mack W. Hunt et al., which issued Sept. 22, 1964 and is entitled
"Highly Basic Calcium-Containing Additive Agent"; U.S. Pat. No.
2,956,018 to Robert L. Carlyle et al., which issued Oct. 11, 1960
and is entitled "Metal Containing Organic Compositions and Method
of Preparing the Same"; U.S. Pat. No. 2,937,991, to Robert L.
Carlyle, which issued May 24, 1960 and is entitled "Method of
Dispersing Calcium Carbonate in a Non-Volatile Carrier"; and U.S.
Pat. No. 2,895,913, to Robert L. Carlyle et al., which issued on
July 21, 1959 and is entitled "Magnesium Containing Organic
Compositions and Method of Preparing the Same."
The colloidal dispersions which are used as a starting material
consist essentially of a nonvolatile diluent, an oil-soluble
dispersing agent, and an alkaline earth metal carbonate. These
materials are present in the following range:
Parts by Weight
__________________________________________________________________________
Suitable Preferred
__________________________________________________________________________
Nonvolatile diluent 2-80 20-70 Dispersing agent 5-55 6-35 Alkaline
earth metal carbonate 1-45 5-30
__________________________________________________________________________
In addition to the nonvolatile diluent, oil-soluble dispersing
agent, and basic metal compound, the colloidal dispersions may
contain minor amounts of the alcohol which is employed in
manufacturing the colloidal dispersion, and of the metal-containing
intermediate which may be employed in manufacturing the colloidal
dispersion.
A wide variety of nonvolatile diluents are suitable in the
colloidal dispersions used as the starting material. The principal
requisite desired in the nonvolatile diluent is that it will act as
a solvent for the dispersing agent which is used. Examples of
nonvolatile diluents which can be used include mineral lubricating
oils obtained by any of the conventional refining procedures;
liquid synthetic lubricating oils, vegetable oils, such as corn
oil, cotton seed oil, and castor oil; animal oils, such as lard oil
and sperm oil; and waxes, such as the petroleum waxes. Of the
waxes, the microcrystalline waxes are preferred. Of the oils in the
preceding examples, the mineral lubricating oils are preferred.
It should be noted that when a wax is used as the nonvolatile
diluent, the colloidal dispersion is a solid at room
temperature.
A variety of oil-soluble dispersing agents are suitable in the
colloidal dispersions which are used in preparing the product used
in my invention. Generic examples of suitable dispersing agents
include oil-soluble sulfonic acids, carboxylic acids, and the metal
salts thereof. The preferred dispersing agents for preparing the
grease-like product used in my invention, are the oil-soluble
sulfonic acids and metal sulfonates.
The term "metal" as used in "metal sulfonates," refers to those
metals which are conventionally used to prepare the metal
sulfonates of commerce. This includes metal sulfonates wherein the
metal is sodium, potassium, magnesium, calcium, and barium. The
more suitable sulfonates are those wherein the metal is calcium or
barium. Preferably, the metal of the metal sulfonate is the same as
the metal of the basic metal compound.
The term "oil-soluble sulfonates," as used herein, refers to those
sulfonates wherein the hydrocarbon portion of the molecule has a
molecular weight in the range of about 300 to about 1,000.
Preferably, this molecular weight is in the range of about 370 to
about 700. These oil-soluble sulfonates can be either synthetic
sulfonates or the so-called mahogany or natural sulfonates. The
term "mahogany sulfonates" is believed to be well understood, since
it is amply described in the literature. The term "synthetic
sulfonates" refers to those sulfonates which are derived from
sulfonation feedstocks which are prepared synthetically. The
synthetic sulfonates include alkyl sulfonates and alkaryl
sulfonates. The alkaryl radical can be derived from benzene,
toluene, ethyl benzene, xylene isomers, or naphthalene. Preferably,
the alkyl groups are branched chain.
Mixtures of sulfonates derived from alkaryl hydrocarbons having
straight-chain alkyl groups and alkaryl hydrocarbons having
branched-chain alkyl groups, and wherein the amount of sulfonate
derived from branched-chain alkaryl hydrocarbons is at least 40
percent by weight, are particularly suitable. Preferably, the
amount of sulfonate derived from branched chain alkaryls is at
least 60 percent by weight.
An example of an oil-soluble alkaryl sulfonate (a synthetic
sulfonate) which has been particularly useful in preparing
colloidal dispersions is the material known as post-dodecylbenzene
sulfonate. Postdodecylbenzene is a bottoms product of the
manufacture of dodecylbenzene. The alkyl groups of
postdodecylbenzene are branched chain. Postdodecylbenzene consists
of monoalkylbenzenes and dialkylbenzenes in the approximate mole
ratio of 2:3 and has typical properties as follows:
Specific gravity at 38.degree. C. 0.8649 Average molecular weight
385 Percent sulfonatable 88 A.S.T.M. D-158 Engler: I.B.P.,
.degree.F. 647 5 .degree.F. 682 50 .degree.F. 715 90 .degree.F. 760
95 .degree.F. 775 F.B.P. .degree.F. 779 Refractive index at
23.degree. C. 1.4900 Viscosity at: -10.degree. C., centipoises 2800
20 centipoises 280 40 centipoises 78 80 centipoises 18 Aniline
point, .degree. C. 69 Pour point, .degree.F. -25
an example of another oil-soluble synthetic alkaryl sulfonate,
which is particularly useful for preparing colloidal dispersions,
is the sulfonate derived from a sulfonation feedstock known as
"dimer alkylate." "Dimer alkylate" has branched-chain alkyl groups
as does postdodecylbenzene. Briefly described, dimer alkylate is
prepared by the following steps:
1. Dimerization of a suitable feedstock, such as cat poly
gasoline,
2. Alkylation of an aromatic hydrocarbon with the dimer formed in
step (1).
Preferably, the dimerization step uses a Friedel-Crafts alkylation
sludge as the catalyst. This process and the resulting product are
described in U.S. Pat. No. 3,410,925.
An example of still another oil-soluble synthetic alkaryl
sulfonate, which is particularly useful for preparing colloidal
dispersions, is the sulfonate derived from a sulfonation feedstock
which I refer to as "NAB Bottoms." NAB Bottoms are predominantly
di-n-alkaryl, wherein the alkyl groups contain from eight to 18
carbon atoms. They distinguish primarily from the preceding
sulfonation feedstocks in that they are straight-chain and contain
a large amount of di-substituted material. The process of preparing
these materials and the resulting product are described in
application Ser. No. 521,794 filed Jan. 20, 1966, now abandoned,
and having the same assignee as the present application. Another
process of preparing a di-n-alkaryl product is described in
application Ser. No. 529,284, filed Feb. 23, 1966, now abandoned
and having the same assignee as the present application.
Mixtures of sulfonates derived from "dimer alkylate" and "NAB
Bottoms" are suitable for preparing the grease-like compositions
used in my invention.
In order to make my disclosure even more complete, U.S. Pat. No.
3,410,925 and application Ser. Nos. 521,794 and 529,284 are made a
part of this disclosure.
Other sulfonates which can be used in the colloidal dispersion
employed as a starting material include, for example, mono- and
poly-wax substituted naphthalene sulfonates, dinonyl naphthalene
sulfonates, diphenyl ether sulfonates, naphthalene disulfide
sulfonates, diphenyl amine sulfonates, dicetyl thianthrene
sulfonates, dilauryl betanaphthol sulfonates, dicapryl
nitro-naphthalene sulfonates, unsaturated paraffin wax sulfonates,
hydroxy substituted paraffin wax sulfonates, tetramylene
sulfonates, mono- and poly-chloro-substituted paraffin wax
sulfonates, nitrosoparaffin wax sulfonates; cyclo-aliphatic
sulfonates, such as lauryl-cyclohexyl sulfonates, mono- and poly-
wax substituted cyclohexyl sulfonates, and the like.
In addition, it is to be understood that the metal salts of the
preceding sulfonates can be formed in situ during preparation of
the colloidal dispersion by neutralization of the corresponding
sulfonic acid.
Suitable carboxylic acids which can be used in preparing the
colloidal dispersion used as a starting material include naphthenic
acids, such as the substituted cyclopentane monocarboxylic acids,
the substituted cyclohexane monocarboxylic acids and the
substituted aliphatic polycyclic monocarboxylic acids containing at
least 15 carbon atoms. Specific examples include cetyl cyclohexane
carboxylic acids, dioctyl cyclopentane carboxylic acids, dilauryl
decahydronaphthalene and stearyloctahydro indene carboxylic acids
and the like and oil-soluble salts thereof. Suitable oil-soluble
fatty acids are those containing at least eight carbon atoms. For
producing the colloidal dispersion in liquid form, I prefer fatty
acids which are liquids at ambient temperatures down to about
15.degree. C. Specific examples include 2-ethyl hexanoic acid,
pelargonic acid, oleic acid, palmitoleic acid, linoleic acid and
ricinoleic acid. Naturally occurring mixtures of predominantly
unsaturated fatty acids, such as tall oil fatty acids, are
particularly suitable.
In addition, it is to be understood that the metal salts of the
preceding carboxylic acids can be formed in situ during preparation
of the colloidal dispersion by neutralization of the corresponding
carboxylic acid.
Process Conditions (Two-step Method)
The thixotropic grease-like composition used to prepare the
composition of my invention can be prepared by treating the
colloidal dispersion with a small amount of water in the presence
of a small amount of an alcohol. From a practical viewpoint, the
amount of water which is used should be at least about 3 percent,
preferably about 7 percent, by weight, based on the colloidal
dispersion. Preferably, the amount of water should not be above 12
percent, and usually not above 20 percent, by weight, based on the
colloidal dispersion. (Larger amounts can be used conceivably, but
no advantage results therefrom. Also, if an extremely long reaction
time can be tolerated, an amount of water less than 3 percent might
be used.) It should be noted that I have found that increasing the
amount of water from 4 or 5 percent to about 7 or 8 percent
provides a pronounced increase in rate of reaction.
The amount of alcohol which is used is in the range of about 0.5 to
about 10 percent, preferably from about 1 to about 5 percent, by
weight, based on the colloidal dispersion. These aforementioned
amounts of alcohol include the residual alcohol present in the
colloidal dispersion which runs from about 0.5 percent to about 3
percent by weight, usually.
It is apparent from the preceding that some colloidal dispersions
have sufficient residual alcohol so that additional alcohol is not
required. Sometimes, the use of additional alcohol will accelerate
the reaction rate. Also, the amount of alcohol required varies with
the type of dispersing agent, in that some dispersing agents
require more alcohol than others. Furthermore, the alcohol which is
added does not have to be the same species of alcohol which is
present as the residual alcohol.
A wide variety of alcohols can be used in the conversion of the
colloidal dispersion to the thixotropic, grease-like composition
used in my invention. Examples of suitable alcohols include the
C.sub. 1 -C.sub. 10 alkanols, the monoether alcohols of ethylene
glycol containing up to eight carbon atoms, and the monoether
alcohols of diethylene glycols containing up to eight carbon atoms.
Preferably, the alcohols have boiling points of at least about that
of water. Examples of suitable alcohols include methanol, ethanol,
propanol, isobutanol, pentanol, hexanol, octanol, decanol,
2-methoxy ethanol, and 2-ethoxy ethanol. Of these isobutanol and
2-methoxy ethanol are preferred.
As is apparent from the preceding discussion, an important feature
of the process of preparing the grease-like composition is the use
of a combination of water and an alcohol to effect a modification
reaction. By "modification reaction" is meant the change from a
fluid, clear colloidal dispersion to a viscous, tacky material.
In the preparation of the composition, heat is applied to the
admixture containing colloidal dispersion, water, alcohol (and,
possibly, volatile solvent or nonvolatile diluent oil). The heat is
applied until the modification reaction occurs which is apparent by
a rapid change in viscosity of the reaction admixture. The
modification reaction occurs at a temperature slightly above
170.degree. F. Usually a temperature of 190.degree.-210.degree. F
is sufficient to cause the reaction to go to completion
rapidly.
In practicing the method of my invention it is often convenient to
use a solution of the composition in a volatile solvent. When the
composition is to be used thusly it is often convenient to prepare
the thixotropic, grease-like composition in the presence of the
volatile solvent. The polymer is then added to the solution. When
the "modification reaction" is conducted in the presence of the
volatile solvent, the occurrence of the reaction is still visible
in that the viscosity changes and the solution changes from a
bright, clear solution to a hazy or cloudy solution. The
temperature employed and the total amount of heat used are not
critical in the two-step method.
ONE-STEP METHOD OF PREPARATION
Starting Materials
The nature and amounts of the starting materials, which are used to
prepare the thixotropic, grease-like composition which is used in
the compositions of our invention, are shown in the following
table:
Parts by Weight
__________________________________________________________________________
Material Suitable Preferred
__________________________________________________________________________
Nonvolatile Diluent 2-80 5-30 Dispersing Agent 2-65 5-35 Alkaline
earth metal (Present as alkaline earth metal carbonate complex)
2-40 10-30 Water 1-6 2-4 Alcohol 10-40 20-30 Volatile Solvent
(Optional*) 0-60 25-55
__________________________________________________________________________
*Previously, in discussing the process conditions for the two-step
method I stated that a volatile solvent, which often is used in
applying the grease-like composition, can be present during the
preparation. Preferably, however, in the two-step method the
grease-like composition is prepared first and dissolved in the
volatile solvent. In the one-step method there is no advantage in
first preparing the grease-like composition and then dissolving it.
In view of this having the volatile solvent present during the
preparation of the composition is a matter of choice dependent on
other factors. The nature of the volatile solvent is described
hereinafter.)
It should be emphasized that the above-stated ranges apply solely
to the one-step process of preparing the grease-like composition.
The ranges differ from those given hereinafter for the grease-like
composition per se, primarily, due to the inclusion of volatile
materials. For this reason the ranges are stated solely to
illustrate the process. Insofar as the above-stated ranges differ
from those given for the grease-like composition per se my
invention is limited only to the ranges stated for the
composition.
Suitable and preferred nonvolatile diluent, dispersing agent and
alkaline earth metal are the same as described previously in
connection with the two-step method.
An alkaline earth metal carbonate, which is formed in situ, is used
in the process. In forming the alkaline earth metal carbonate, an
admixture is prepared of alkaline earth metal basic compound,
selected from the group consisting of oxides, hydroxides, and
alcoholates, dispersing agent, nonvolatile diluent, and alcohol.
The admixture is then treated with CO.sub. 2 to form the carbonate.
Alternatively and preferably, the alkaline earth metal carbonate is
formed by adding an alcoholic slurry of the alkaline earth metal
basic compound to an admixture of the other materials. The total
admixture is then treated with CO.sub. 2 to form the carbonate.
Suitable alcohols for use in the "one-step" process include C.sub.
1 -C.sub. 10 alkanols, the monoether alcohols of ethylene glycol
containing up to eight carbon atoms, and the monoether alcohols of
diethylene glycol containing up to eight carbon atoms. Examples of
suitable alcohols include methanol, ethanol, propanol, isobutanol,
pentanol, hexanol, octanol, decanol, 2-methoxy ethanol, and
2-ethoxy ethanol. The preferred alcohols are the C.sub. 1 -C.sub.
10 alkanols, with the C.sub. 1 -C.sub. 3 alkanols being more
preferred.
Process Conditions
In carrying out the one-step method, the oil soluble dispersing
agent (whether pre-formed, or formed in situ), nonvolatile diluent
and alcohol-alkaline earth metal basic compound slurry are
intimately admixed preparatory to carbonation. The water component
of the mixture may be added at any time prior to the final
controlled heating step, and may be added at different times in two
or more increments, if desired. The same is true of any alcohol
which is added in addition to that introduced with the slurry. In
the case of the water, however, it is preferred to add the entire
amount of water at the outset and prior to carbonation since
thicker products appear to be yielded when this procedure is
followed.
In carrying out the carbonation of the mixture to form the
carbonate, about 1.5 moles of carbon dioxide must be introduced to
the mixture for each mole of alkaline earth metal present. In
addition, the gas necessary to complete carbonation (as described)
must be introduced to the mixture within about 90 minutes in order
to obtain the high viscosity grease-like product sought, and it is
preferred that this amount be introduced at a sufficient rate to
achieve completion of carbonation and formation of the complex
within from 20 to 40 minutes.
The carbon dioxide required may be introduced into the mixture by
blowing or bubbling the gas through the mixture, or by immersing
dry ice in the mixture. The reaction is exothermic and its progress
can be followed by observation of the change in temperature of the
reaction mixture. It is preferred that the temperature be retained
below about 50.degree. C during carbonation.
Upon completion of carbonation, the mixture, which then contains
the oil-soluble dispersing agent, the nonvolatile carrier material,
and the alkaline earth metal carbonate resulting from carbonation
is subjected to a controlled heating step. Between the carbonation
procedure and the heating step, water and/or alcohol may be added
to the mixture in order to bring the total content of these two
components in the mixture up to that which has been hereinbefore
described as the operative requirements in this respect. The
heating step with which the one-step method is concluded is quite
important, and the manner in which it is conducted determines
whether the desired high consistency-low penetration grease-like
compositions are yielded, or whether a fluid dispersion of the
general type described in U.S. Pat. Nos. 2,956,018 and 2,861,951 to
Carlyle and also in U.S. Pat. Nos. 3,150,088 and 3,027,325 to
McMillen are formed.
In the final heating step of the process, two objectives are sought
by the heating. First, the light solvents must be stripped from the
mixture, except, perhaps, for small amounts of water and alcohol
and such light hydrocarbon carrier material as it is desired to
have remain in the final product for purposes of enhancing the ease
of processing. Thus, the heating will remove substantially all of
the alcohol and water which are not consumed in the grease
producing reaction, and any very light hydrocarbon solvents, such
as hexane, which are incorporated in the mixture in order to
facilitate the carbonation of the alkaline earth metal base
compound.
The second function of the heating is to supply the heat of
reaction which is necessary to effect the conversion of the mixture
to a high consistency grease-like composition.
To then describe the specific parameters which are critical in the
heating of the heterogeneous mixture which exists after carbonation
in order to form the described grease-like compositions, it is
necessary that the mixture be heated to a temperature above about
50.degree. C.
After reaching the threshold temperature of about 50.degree. C for
effecting the conversion reaction, it is then desirable to
gradually increase the temperature of the reaction mixture to above
100.degree. C, and preferably ultimately to about 160.degree. C.
This is because water in the mixture commences to be stripped or
driven off at 100.degree. C, and the total processing time becomes
unacceptably long when temperatures exceeding this level are never
attained during the final heating step. On the other hand, it is
critical to the formation of the desired grease products that the
temperature zone of 50.degree. C to 100.degree. C not be traversed
too rapidly. The effect of increasing the temperature of the
mixture at an excessive rate is to drive an excessive amount of the
water from the mixture before it has had an opportunity to enter
into the reaction necessary to convert the mixture to grease. From
this it follows that the greater the amount of water in the mixture
within the operative range of water content hereinbefore described,
the higher may be the rate at which the temperature is raised from
50.degree. C to 100.degree. C.
A definite relationship exists between the amount of water in the
heated mixture and the time required to traverse the temperature
zone of from 50.degree. C to 100.degree. C. For example, where the
minimum operative quantity of water is present in the mixture at
the inception of the final heating step (that is, 0.25 mole of
water per mole of overbasing alkaline earth metal present), the
time within which the mixture must be maintained between 50.degree.
C and 100.degree. C is at least 4.5 hours. This time period
decreases in a fairly regular uniform fashion as the amount of
water present in the mixture with respect to the amount of alkaline
earth metal present increases. Thus, when a water level of about
2.5 moles of water per mole of alkaline earth metal is reached, a
time period of only about 45 minutes in the temperature range of
50.degree. C to 100.degree. C is required in order to effect the
desired conversion to the grease-like product. At this and higher
water levels, the time requirement to effect the desired conversion
drops off very sharply so that the reaction mixture may be heated
from 50.degree. C to 100.degree. C at as rapid rate as may be
desired. This relationship between the transition time for
elevating the temperature of the reaction mass from 50.degree. C to
100.degree. C in instances where the water content of the reaction
mixture is in the range of from about 0.25 mole of water per mole
of alkaline earth metal (present in an overbasing capacity) to
about 2.5 moles of water per mole of the metal can be approximated
by the expression:
t = 0.75 + 1.7 .times. (2.5 - m)
where t equals the time in hours within which the mixture must be
retained in the temperature range of between 50.degree. C and
100.degree. C, and m is the number of moles of water present in the
mixture per mole of alkaline earth metal present in the mixture in
an overbasing capacity.
Where the reaction mixture is heated too rapidly to above
100.degree. C, the water appears to be stripped from the mixture
too fast to permit the completion of reaction. The result then is
that there is formed a homogeneous dispersion of alkaline earth
metal carbonate which is quite fluid and is similar to the
lubricating oil additives which are yielded by the processes
described in U.S. Pat. Nos. 2,956,018 and 2,861,951 to Carlyle and
also in U.S. Pat. No. 3,150,088 to Hunt.
The formation of the desired grease-like product is clearly
evidenced by the marked and rapid change in the observable physical
properties of the mixture. The most striking change, perhaps, is in
the viscosity of the mixture, which increases rapidly as the
conversion to grease-like product occurs. The grease-like product
is tacky and opaque and is macroscopically homogeneous. It is
highly basic in terms of its acetic base number. (This term is
well-known in the art, being described in U.S. Pat. No.
3,150,088.)
As the starting mixture undergoes conversion or modification to
yield the grease-like product, it will often be desirable to add a
volatile solvent to the mixture in order to maintain its viscosity
within a manageable range.
In the heating step, it is not necessary to remove all of the water
and alcohol from the mixture, particularly where the product is to
be used as a rust inhibitor.
It is to be understood that the one-step method of preparing the
grease-like composition is not part of my invention. This method is
disclosed and claimed in application Ser. No. 727,719 filed May 8,
1968.
The Polymer
The term polymer as used herein includes certain copolymers which
meet the specified requirements. Suitable polymers for use in our
invention have the following properties:
a. a low degree of crystallinity; i.e., less than 50 percent,
preferably less than 25 percent, crystallinity,
b. a molecular weight in the range of from about 3,000 to about 1
million,
c. a high solubility in predominantly aliphatic hydrocarbon
solvents, such as hexane, n-decane, Stoddard solvent, kerosene and
petroleum lubricating oils.
Polymers meeting the above-listed description are often termed
atactic or amorphous.
Examples of suitable types of polymers include low molecular weight
or low density polyethylene, amorphous polypropylene,
polyisobutylene, polyterpenes; copolymers of the foregoing with
vinyl monomers, such as vinyl chloride, and vinyl esters, such as
vinyl acetate; polyacrylic acids, and polymethacrylic acids.
Specific examples of suitable polymers include the following:
Supplier Tradename Polymer Type
__________________________________________________________________________
Dow Zetafax Ethylene-isobutyl acrylate copolymer DuPont Elvax
Ethylene-vinyl acetate copolymer DuPont Alathon Low molecular
weight polyethylene Eastman Eastobond Polyolefin hot melt adhesive
Eastman Epolene Low molecular weight polyethylenes and amorphous
polypropylenes Goodyear "Wing Tack" Polyterpene Neville Nevillac
Phenol modified Coumaroneindene resin Rohm and Haas Acryloid
Polymethyl meth-acrylate Kenrich Kenflex Synthetic thermoplastic
resin from condensation of high boiling aromatics with Formaldehyde
__________________________________________________________________________
Particularly suitable polymers include polyterpenes, amorphous
polypropylenes, polyolefins, ethylene-isobutyl acrylate copolymers
and ethylene-vinyl acetate copolymers. Preferred polymers are the
polyterpenes, amorphous polypropylenes, low molecular weight
polyethylenes, and ethylene-vinyl acetate copolymers.
Relative Amounts of Polymer and Thixotropic, Grease-Like
Composition in Our Composition
Parts by Weight Polymer Thixotropic Composition Suitable 0.1-25
75-99.9 Preferred 0.2-10 90-99.8
Preparation of Blend of Polymer and Thixotropic, Grease-like
Composition
No particular technique is required to prepare the blend of polymer
and thixotropic, grease-like composition. This is particularly true
since usually the amount of polymer used is relative small. After
adding the required amount of polymer to the thixotropic,
grease-like composition, preferably slowly in incremental amounts,
the admixture is stirred sufficiently to provide a homogeneous
composition.
Application of the Composition to Metal Surfaces
The composition used in my invention can be applied "as is" to the
metal surface, usually, by means of a brush. Preferably, the
composition is diluted in a volatile solvent for application to the
surface. The use of a volatile solvent provides a more uniform film
on the metal surface and enables the use of a spray. The latter can
reduce substantially the cost of applying the composition.
The nature of the volatile solvent used is not a salient feature of
my invention, and it is believed those skilled in the art, without
undue experimentation, can readily ascertain suitable solvents.
Examples of suitable solvents include volatile hydrocarbon
solvents, such as Stoddard solvent, kerosene, petroleum naphtha and
the like. Also, certain nonflammable chlorohydrocarbons are
suitable. For reasons of safety, it is preferable to use solvents
having a flash point of at least 100.degree. F and even higher. The
amount of solvent is dependent on the particular method of
application. Usually, a suitable amount of solvent is in the range
of from about 40 to about 90 percent by weight. Preferably, it is
from about 50 to about 80 percent by weight.
The composition of my invention can be used as a primer on any type
of metal surface which is to be coated with a conventional paint.
Preferably it is used on metals which are subject to severe
corrosion, such as ferrous metals.
A particular advantage of the composition used in my invention is
that the metal surface requires little or no preparation prior to
application. Many primers require that the surface be meticulously
clean (e.g. by chemical cleaning or sand-blasting to white metal)
prior to application. By contrast, the composition, used in my
invention, when applied to rusted surfaces result in a satisfactory
film. Usually, the surface is treated moderately, e.g. by scraping
or brushing sufficiently to remove loose scale prior to application
of the grease-like composition.
The amount of composition which is applied can be readily
determined by those skilled in the art. A thicker film usually
provides better protection but, obviously, is more expensive. A
film having a thickness of about 2.5 mils has been found to be
optimum with respect to both performance and economics.
The composition should be substantially solvent-free before
applying the conventional paint. Usually, the composition is
solvent-free in 18-72 hours.
Suitable Paints
A variety of conventional paints have been found to be
satisfactorily applied over the composition used in my invention.
Examples of suitable generic-type paints include the following:
Amine cured epoxy (2 component)
Polyamide cured epoxy
Urethane (2 component)
Alkyd enamel
Phenolic enamel
Acrylic water emulsion
Vinyls (solvent or emulsion based)
Knowing that the composition described herein is satisfactory as a
primer for conventional paints anyone skilled in this art can
readily select a suitable paint for the outer surface. Similarly,
the selection of a paint to provide optimum results can be made
readily.
Advantages of My Invention
As indicated previously, a primary advantage of the use of the
composition as a primer is that the metal surface requires little,
or no, preparation prior to being coated with the composition.
Secondly, use of the composition as a primer provides an improved
resistance to corrosion of metal surfaces.
Thirdly, use of the composition as a primer permits an increase in
the thickness of a single-coat film, particularly with alkyd
paints.
Fourthly, use of the composition as a primer results in a film
which is harder, tougher and less tacky than the use of the
composition of application Ser. No. 729,875 as a primer.
In order to disclose the nature of the present invention still more
clearly, the following illustrative examples will be given. It is
to be understood that the invention is not to be limited to the
specific conditions or details set forth in these examples except
insofar as such limitations are specified in the appended claims.
Unless stated otherwise, all parts stated are by weight.
EXAMPLE 1
This example illustrates the reduction in tackiness of the
polymer-thixotropic, grease-like composition as compared to the
thixotropic, grease-like composition alone.
The thixotropic grease-like composition was prepared using the
"one-step" method described hereinbefore.
The sulfonic acid solution employed contained 27 percent (by wt.)
mixed sulfonic acids, 60 percent (by wt.) n-hexane and 13 percent
(by wt.) nonvolatile mineral oil (pale oil). The mixed sulfonic
acids contained 70 percent (by wt.) oil-soluble sulfonic acids
derived from "dimer alkylate" and 30 percent (by wt.) oil-soluble
sulfonic acids derived from "NAB" Bottoms. Both "dimer alkylate"
and "NAB" Bottoms have been described in the foregoing.
The following materials were added to a 12-liter flask:
2,000 parts Stoddard solvent
15 parts water
1,582 parts sulfonic acid solution
To the above-listed admixture was added a slurry of the
following:
345 parts Ca(OH).sub.2
1,587 parts methanol
While stirring the resulting admixture it was blown with CO.sub.2.
Using a large flow meter, with a reading of 10, (approximately
9,250 cc's/minute) it was blown with CO.sub.2 until the temperature
peaked. Then the rate of blowing was reduced to a meter reading of
5 and continued for 15 minutes. The time-temperature data for the
CO.sub.2 blowing were as follows:
Begin CO.sub.2 28.degree. C. After 5 min. 36.degree. C. After 10
min. 48.degree. C. After 11 min. 49.degree. C. After 12 min.
51.degree. C. (peak) Following peaking 5 min. 44.degree. C. 10 min.
40.degree. C. 15 min. 36.degree. C.
the carbonated admixture was then heated to reflux temperature
(67.degree. C) and maintained at this temperature for 15
minutes.
The carbonated admixture was cooled to about 55.degree. C,
whereupon 140 parts water were added over a 15-minute period.
The resulting admixture was heated to reflux temperature and
maintained at this temperature for 15 minutes.
The admixture was then heated slowly to a temperature of
160.degree. C. to remove the lower boiling solvents.
The yield of product was 2,720 parts.
To the product was added 700 parts Stoddard solvent to product a
final product of 3,420 parts.
The final product had the following composition:
12.2 percent Calcium sulfonate
12.2 percent Calcium carbonate*(*Acetic base
number=.apprxeq.137)
9.1 percent 100 Pale oil
66.5 percent Stoddard solvent
Various polymers were added to the product at a concentration of 1
to 5 weight percent based on the nonvolatile content. Blending of
the polymer and thixotropic, grease-like product was obtained by
adding the polymer to the heated (80.degree. to 150.degree. C)
product, described above, and stirring until all of the polymer
dissolved. The nature of the various polymers used is shown in
Table I.
In order to evaluate the tackiness of the various compositions
(thixotropic, grease-like composition plus polymer), a solution of
the compositions were applied to steel "Q" panels. Upon evaporation
of the volatile solvent, a film of the composition (thixotropic,
grease-like composition plus polymer) formed on the panels. The
films of the various compositions were evaluated for tackiness with
an Instron machine using the following procedure. A brass plunger,
0.500 inch in diameter and weighing 243.5 grams was lowered onto
the surface of a coated panel and its weight allowed to rest on the
panel for about 30 seconds. Then the plunger was lifted from the
panel. A surface with no tackiness or adhesiveness would require a
force of 243.5 grams to lift the brass plate off the surface. The
amount of force required, in excess of 243.5 grams, to lift the
brass weight was a measure of the tackiness of the coated
surface.
The nature of the polymers tested and the excess force data are
shown in Table I.
TABLE I
Instron Test Measurement of Tackiness of Coatings
Film Excess Thickness Force Composition Mils Grams*
__________________________________________________________________________
Thixotropic, Grease-like Composition alone (TGC) 7.3 72.4.+-.13
TGC+5% "Nevillac" 10 (1) 7.3 38.7.+-.12 TGC + 5% "Eastobond" M-3
(2) 2.5 27.3.+-.10 TGC + 5% "Acryloid" 917 (3) 2.5 54.8.+-.9 TGC +
5% "Kenflex" A (4) 2.0 5.8.+-.1 TGC + 5% "Epolene" D-11 (5) 4.6
14.3.+-.3 TGC + 5% "Zetafax" 1278 (6) 3.4 6.5.+-. 1 TGC + 5%
"Zetafax" 1275 (6) 5.3 10.9.+-.3 TGC + 2% "Epolene" C-16 (7) 2.4
16.7.+-.6
__________________________________________________________________________
*Lower values indicate improved performance. (1) A phenol modified
coumarone-indene resin from Neville Chemical Company. (2) A
polyolefin based hot melt adhesive resin from Eastman Chemical
Products, Inc. (3) A polymethyl methacrylate from Rohm and Haas
Company (4) A synthetic thermoplastic resin from condensation of
high boiling aromatics with formaldehyde from Kenrich
Petrochemicals, Inc. (5) An amorphous polypropylene from Eastman
Chemical Products, Inc. (6) An ethylene-isobutyl acrylate copolymer
from Dow Chemical Co. (7) A low molecular weight polyolefin from
Eastman Chemical Products, Inc.
EXAMPLE 2
This example illustrates the improved mechanical performance of a
conventional paint over the composition of my invention as compared
to the composition of application Ser. No. 729,875.
The following compositions were tested:
A -- the composition of Ser. No. 729,875
B -- the thixotropic, grease-like composition of Example 1 --
similar to A but containing less nonvolatile diluent oil
C -- composition B plus 3 percent "Eponlene" C-16
D -- composition B plus 5 percent "Eastobond" M-5W (amorphous
polypropylene)
Films of the compositions were cast on 4 in. .times. 8 in. mild
steel "Q" panels. The coated panels were painted over with a
conventional white alkyd enamel. It was noted that the coatings
from compositions C and D accepted the paint top coat more readily
and covered more smoothly than did the coatings from compositions A
and B. The alkyd enamel top coat was dry in 24 hours over all the
compositions.
The coatings were subjected to adhesion and abrasion resistance
tests. Adhesion was evaluated by a "scotch tape" test. In this test
a grid 3/4 in. .times. 3/4 in. was cut through the coating down to
bare metal. The grid consisted of 7 lines 1/8 in. apart intersected
at right angles by another 7 lines at 1/8 in. spacing. A 3/4 in.
wide strip of "Scotch" magic transparent tape was placed over the
grid and pressed firmly in place with a finger. Then the tape was
lifted, quickly and smoothly. The number of squares, out of the
total of 36, in which the coating separated from the metal and
adhered to the tape was counted. A lower value in this test
indicates improved results.
The abrasion resistance was measured by determining the amount of
force that must be applied to 1 square inch of No. 100 grit
sandpaper being pulled over the surface of the coating before bare
metal is revealed. In this test a higher value indicates improved
results.
The results of the test in this example are shown in Table II.
TABLE II
Adhesion and Abrasion Tests of Coatings
Thick- Thickness ness Adhesion Abrasion Topcoat Mils Primer Mils
Test Test
__________________________________________________________________________
White alkyd enamel 3.2.+-.0.3 None 0 15 >14 White alkyd enamel
.apprxeq.3 Comp. A 2.58.+-.0.08 21 .apprxeq.6 White alkyd enamel
enamel .apprxeq.3 Comp. B 3.19.+-.0.13 8 .apprxeq.71/2 White alkyd
enamel .apprxeq.3 Comp. C 3.91.+-.0.17 1 .apprxeq.10 White alkyd
enamel .apprxeq.3 Comp. D 4.37.+-.0.16 0 .apprxeq.9
__________________________________________________________________________
EXAMPLE 3
This example shows the improvement obtained when using the primer
of my invention (which contains a minor amount of polymer) as
compared to the composition of U.S. Pat. No. 3,384,586 (which
contains a major amount of polymer) when the latter is used as a
primer.
The thixotropic, grease-like composition was prepared using the
"two-step" method.
The colloidal dispersion of calcium carbonate used as a starting
material had the following composition:
30 percent calcium sulfonate
43 percent nonvolatile diluent (170 pale oil)
27 percent calcium carbonate*(*The material had an acetic base
number of about 300.
To a 10-quart Hobart mixer bowl were added 6,000 parts of the
colloidal dispersion of calcium carbonate. The material was heated
to 150.degree. F whereupon the following were added:
600 parts water
30 parts methoxy ethanol
The admixture was heated slowly to 200.degree. to 210.degree. F and
then heated. The total time of heating from 150.degree. to
210.degree. F was about 1 hour. The solvents were removed by
heating to 315.degree. F using a reduced pressure (partial house
vacuum).
The resulting product was a thixotropic, grease-like composition
having an ASTM penetration of 133 at 77.degree. F.
Using a planetary type grease mixer the following compositions were
prepared:
Composition A -- parts
78.4 Stoddard solvent
53.4*(*This composition is typical of U.S. Pat. No. 3,384,586.)
90 polyvinyl chloride
34 dioctyl phthalate
10 TGC**(**Thixotropic, grease-like composition prepared in this
example.)
Composition B -- parts
61.4 Stoddard solvent
38.6*(*This composition is comparative to U.S. Pat. No. 3,384,586
and illustrates the properties of a composition containing a minor
amount of polymer.)
10 polyvinyl chloride
3.8 dioctyl phthalate
90 TGC
Using a Waring blender the following compositions were
prepared:
Composition C -- parts
105.5 Stoddard solvent
70.3 of:
90 polyterpene resin ("Wing Tack" 95)
10 TGC
Composition D -- parts
60.9 Stoddard solvent
39.1 of:
10 polyterpene resin ("Wing Tack" 95)
90 TGC
Composition E -- parts
61.7 Stoddard solvent
38.3 TGC
The viscosity characteristics of the above-described compositions
are shown in Table III.
---------------------------------------------------------------------------
TABLE III
Brookfield Viscosity at 77.degree. F. No. 2 Spindle, cps. Comp- Wt.
% Non- 12 30 osition volatile RPM RPM Ratio
__________________________________________________________________________
A 40.5 311 148 2.10 B 38.6 467 275 1.70 C 40.0 <25 <10 -- D
39.1 611 317 1.93 E 38.3 1016 522 1.95
__________________________________________________________________________
the data listed above shows that blends containing a large amount
of thixotropic, grease-like compositions (e.g. B and D) have a much
higher viscosity than do blends containing a small amount of
thixotropic, grease-like composition (A and C).
EXAMPLE 4
This example shows the film properties of various compositions
similar to those described in Example 3. The compositions were the
same with the exception that the amount of Stoddard solvent was
different in Compositions A and C. In these compositions the amount
of Stoddard solvent was as follows:
Composition A -- 46.6 parts
Composition B -- 29.7 parts
A panel was dipped in the composition. After allowing the solvent
to evaporate the film was measured and the coated panel was
evaluated. The results are shown below:
---------------------------------------------------------------------------
TABLE IV
Compositions
__________________________________________________________________________
A B C D E Dip Film, Thickness, mils 5.93 2.45 3.00 2.77 3.64 Film
prop- erties: Appearance and Feel Opaque, Tan, Tan, Tan, Tan,
white, trans- trans- trans- trans- soft lucent, parent, parent,
parent, tacky, hard, flexible, flexible, brittle slightly tacky
tacky Paint Adhesion Poor Good Very Very Good Poor Good
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EXAMPLE 5
This example shows the performance as primer of the compositions
described in Example 4. First, the steel panels were coated with
the compositions as a primer; then they were coated with a white
alkyd enamel. The panels were evaluated in the ASTM B-117 Salt Fog
Test after 100 hours exposure. The results are shown in Table V.
##SPC1##
EXAMPLE 6
This example illustrates another variation of the one-step method
of preparing the colloidal dispersion of calcium carbonate, which
is used to prepare the thixotropic, grease-like composition.
The methoxy ethanolic solution of Ca methoxy ethoxide was prepared
in accordance with the procedure described in U.S. Pat. No.
3,150,088.
The sulfonic acid solution employed in this example contained 27
percent (by wt.) mixed sulfonic acids, 60 percent (by wt.) n-hexane
and 13 percent (by wt.) nonvolatile mineral oil (pale oil). The
mixed sulfonic acids contained 60 percent (by wt.) oil-soluble
sulfonic acids derived from "dimer alkylate" and 40 percent (by
wt.) oil-soluble sulfonic acids derived from "NAB" Bottoms. Both
"dimer alkylate" and "NAB" Bottoms have been described in the
foregoing.
To a one-liter flask were added:
150 g. -- sulfonic acid solution
49 g. -- 100 pale oil
The admixture was heated to 35.degree. C and the sulfonic acid was
neutralized by adding 31 grams of a methoxy ethanolic solution of
Ca methoxy ethoxide-carbonate, containing 6.95 percent Ca. The
temperature was adjusted to 40.degree. C and the following
solutions were added concurrently at constant rates:
252 g. -- methoxy ethanolic solution of Ca methoxy
ethoxide-carbonate (containing 6.95 percent Ca)
59.4 g. -- solution containing:
29.3 percent methoxy ethanol
14.2 percent methanol
56.5 percent water
After the addition, the admixture was heated at reflux temperature
for 5 hours. Then 170 grams of Stoddard solvent were added and the
major portion of the solvents were removed by heating to
150.degree. C.
Removal of the Stoddard solvent from a portion of the product
resulted in a thixotropic, grease-like composition having an ASTM
penetration of 187.
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