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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention describes acid stable surfactant materials.
2. Description of the Art
Ordinarily surfactant compositions are formulated at an alkaline pH. Thus
most laundry products or bottle cleaning formulations have an in-use pH of
from about 8 to about 12. It is however, desirable when formulating
certain hard surface cleaning compositions to utilize a high acid content
such as a pH of 2 or less.
The highly acid cleaning compositions are often used where there are salt
deposits such as from milk acids (milkstone), or calcium or magnesium
carbonate deposites such as in toilets or in equipment in which relatively
hard wataer is utilized. Iron salts are also ordinarily removed with acid
cleaning compositions.
Conventional surfactants for cleaning hard surfaces are described in U.S.
Pat. No. 3,591,510 to Zenk issued July 6, 1971. An article entitled A
Greasy Soiled Hard Surface Cleaning Test by Morris A. Johnson, JAOCS,
Volume 61, No. 4, pages 810-813 (April 1984), describes a series of
commercially available solvent-based and water-based cleaners useful for
removing greasy soil. Further disclosures of hard surface cleaning
formulations are also discussed in Formulation of Hard Surface Spray
Cleaners by Johnson et al as reported in detergents and specialties, June
1969, pages 28-32 and 56.
Uses and combinations of glycosides are disclosed in Rohm and Haas
publications CS-400 and CS-449 dated January 1978 and November 1979
respectively.
It is also known that oil wells are advantageously acidized to open the
rock formations to allow free drainage of oil into a sump from which it is
more easily pumped. In such formulations, it is desirable that a
surfactant be included to assist in carrying the dissolved rock. This may
be accomplished through a surfactants' foam forming ability. It is also
desirable in the acid treatment of oil bearing strata to have the
surfactant foam sufficiently to fracture the rock. The surfactant
desirably loses its foaming capacity following acidization or
fractionation in that the foam would inhibit the flow of the oil through
the formation which is contrary to the stated purpose of providing free
flow of the oil.
It is known from Arnaudis in European Published Application No. 0077167
dated Apr. 20, 1983 that strong acids in combination with reducing acids
may be used to prepare glycosides. Urfer, in U.S. patent application Ser.
No. 06/668,762 filed Nov. 6, 1984 discloses weak buffering acids in
combination with glycosides.
It has now been found that glycoside surfactants of the type described
herein have excellent stability under highly acid conditions. The
glycosides which are excellent surfactant materials provide sufficient
foaming in hard surface cleaners so that the remainder of the composition
e.g., acid, does not merely run off of the surface being cleaned. It is
also observed that the glycoside surfactant is one which is stable but
which eventually will cease foaming, therefore making it an excellent
acidizing or fracturing surfactant.
Throughout the specification and claims, percentages and ratios are by
weight, temperatures are in degrees of Celsius and pressures are in
KPascals over-ambient unless otherwise indicated. To the extent that the
references cited herein are applicable to the present invention, they are
incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention describes a composition comprising:
(a) from about 1% to about 70% by weight of a monoglycoside;
(b) from about 1% to about 70% by weight of a polyglycoside; and
(c) from about 5% to about 75% by weight of an acid having a K.sub.1 of
2.5.times.10.sup.-4 or greater.
A further embodiment of the present invention is a composition comprising:
(a) a member selected from the group consisting of:
(i) from about 1% to about 70% by weight of a monoglycoside; and
(ii) from about 1% to about 70% by weight of a polyglycoside; and,
(iii) mixtures of (i) and (ii);
(b) from about 5% to about 75% by weight of an acid having a K.sub.1 of
2.5.times.10.sup.-4 or greater.
DETAILED DESCRIPTION OF THE INVENTION
The glycosides with which the present invention is concerned are typically
represented by the formula:
R(OG).sub.x
where R is an organic hydrophobic moiety conveniently containing from about
6 to about 30; preferably 6 to 24; more preferably 8 to 20; and most
preferably 9 to 18 carbon atoms. The organic hydrophobic moiety may be
alkyl, alkylphenol, alkylbenzyl, hydroxyalkyl alkylphenol, hydroxyalkyl
and the like.
The hydrophobic moiety may also include an alkoxy group therein such that
the value R may be formulated from an alcohol which has been alkoxylated
thereby providing an alkoxy group between the glycoside and the
hydrophobic moiety. In the formula given above, O is stated to be an
oxygen atom and provides the linkage (ordinarily formed through an acetal
mechanism) between the hydrophobic moiety and the saccharide (G).
Typical saccharides employed herein are fructose, glucose, mannose,
galactose, talose, gulose, allose, altrose, idose, arabinose, xylose,
lyxose and ribose and mixtures thereof. Preferably, the glycoside is
formed from glucose units. It is further noted within the description
given in the Summary that the respective monoglycoside component need not
necessarily be the same as the polyglycoside component. Therefore, it is
possible that the monoglycoside is based upon glucose whereas the
polyglycoside may be a xyloside-based glycoside. Preferably, both the
monoglycoside (a) and the polyglycoside (b) are both glucose-based. The
saccharide units within the polyglycoside may also be mixed such as using
fructose and glucose to give sucrosyl structure. The glycoside, whether
mono or poly or mixed, is added in a sufficient amount to reduce the
surface tension of the acid.
The value x given in the formula indicates the degree of polymerization
(DP) which is stated to be the average value of the saccharide units
within the glycoside. Thus a polyglucoside having a DP of 2 (x=2)
indicates that the polyglycoside contains two glucose units. More
specifically, the value of x will vary between about 1.1 and about 8;
typically from about 1.2 to about 5, and most preferably from about 1.4 to
about 3.
The unmodified glycosides utilized herein may be prepared according to the
process described in U.S. Pat. No. 4,223,129 issued Sept. 6, 1980 to Roth
et al. Alternatively, the glycosides may be prepared by the route of
Mansfield, U.S. Pat. No. 3,839,318 issued Oct. 1, 1974. A further
disclosure of preparing a glycoside is found in U.S. Pat. No. 3,219,656
issued to Boettner et al on Nov. 23, 1965.
Modified glycosides which are utilized herein contain alkoxy groups pendant
from the saccharide. The preparation of such materials is generally
described in U.S. Pat. No. 3,640,998 to Mansfield issued Feb. 8, 1972 and
herein incorporated by reference. The alkoxylated glycosides of Roth and
Moser described in a U.S. Application Ser. No. 06/704,828 filed Feb. 22,
1985 are also useful herein.
The acids utilized in the present invention are typically strong acids
including sulfuric, hydrochloric, gluconic, nitric, sulfamic, oxalic,
phosphoric, phosphorous or any other strong acid. The acid should have a
dissociation constant at K.sub.1 at 25.degree. C. of equal to or greater
than 2.5.times.10.sup.-4 ; preferably equal to or greater than
1.times.10.sup.-4 ; more preferably equal to or greater than
5.times.10.sup.-3 ; most preferably 1.times.10.sup.-3 or greater. The acid
employed at 0.1N in distilled water at 25.degree. C. should give a pH of
1.8 or less; preferably 1.6 or less.
While other weaker acids may be employed these materials are not favored
for the highly acid conditions normally encountered in acidizing
oil-bearing strata or for the cleaning of toilet bowls or milk (food)
processing equipment.
The amount of monoglycoside utilized in the present composition is
conveniently from about 1% to about 70% by weight; preferably from about
3% to about 55% by weight; and most preferably from about 5% to about 45%
by weight.
The amount of polyglycoside employed herein is conveniently from about 1%
to about 70% by weight; typically from about 3% to about 55% by weight;
and most preferably from about 5% to about 45% by weight. The ratio of
monoglycoside to polyglycoside is preferably from 20:1 to 1:20 to ensure
proper cleaning effect.
The acid utilized herein is typically employed in the composition at from
about 5% to about 70% by weight of the actual acid species e.g., 37%
hydrochloric acid is expressed as a 100% HCl basis. Thus the amount of
acid utilized is conveniently from about 6% to about 50%; and most
preferably from about 8% to about 45% by weight.
As previously noted, the glycosides are typically obtained from the
processes of the references cited herein. The desired average degree of
polymerization of the total glycoside present may be obtained by preparing
a single mixture of glycoside and polyglycoside. Alternatively, separate
glycosides may be obtained and thereafter formulating the product to
obtain the desired DP.
The acid and the glycoside may be mixed to the desired proportions in any
convenient manner. It is also contemplated herein that when using the
acidizing or fracturing aspect of the present invention that the glycoside
surfactant and the acid be mixed at the well site. It is desired that when
mixing the glycoside and the acid, that a minimal amount of agitation be
employed as this tends to cause the glycoside to foam which is not
particularly desirably. As the glycoside and the acid are both compatible
liquid materials, it is possible to form a simple mixture or upon careful
agitation to obtain a true solution of the glycoside and acid.
As most of the acids employed herein are obtained in their concentrated
aqueous form, it is a further desirable variable herein that water be
included within the composition. The amount of water employed herein is
typically from about 10% to about 95%; and preferably from about 15% to
about 75%.
Other materials which may be incorporated within the compositions herein
include, depending upon the use employed, an anionic surfactant such as an
alkylsulfate, paraffin sulfate, paraffin sulfonate, olefin sulfonate,
alkylether sulfate, or an alkylbenzene sulfonate. These anionic
surfactants are typically found in the form of their soidum, potassium or
ammonium salt, however, it is noted herein that due to the high degree of
acidity in the present compositions that the anionic surfactants will
typically be in their acid form to a substantial degree notwithstanding
the cationic salt species employed.
Amines may be included herein at from 0% to 50% by weight to lessen acid
etching of metal surfaces. Preferably, the amines will be a nonaromatic
material. The amine should be used at less than a 10:1 ratio to the
glycoside. Quaternary compounds may be included to provide disinfectant
effect.
Additional ingredients which may be employed herein are materials such as
detergent builders and abrasive materials. Certain abrasive materials,
such as calcium carbonate, would tend to dissolve and liberate carbon
dioxide. Thus it is more preferred that a material such as a silica be
employed as the abrasive to avoid having the abrasive material decompose
upon storage. The amount of detergent builder or abrasive which may
included in the compositions of the present invention is typically from
about 2% to about 40%; typically from about 3% to about 30% by weight.
Suitable builders include the phosphates, NTA, aluminosilicates and the
builders of Valenty disclosed in U.S. applications, Ser. Nos. 06/575,421
and 06/664,451 filed Jan. 31, 1984 and Oct. 23, 1985 respectively.
EXAMPLE I
The following compositions are prepared by obtaining a glycoside of the
average degree of polymerization (DP) and having an alkyl chain length
shown as carbon chain. The acids are presented on an active "solids"
basis.
__________________________________________________________________________
STABILITY OF GLUCOSIDE IN ACID MEDIUM
SURFACE TENSION
SURFACE TENSIONS
(25.degree. C.) (AFTER 7
CARBON (25.degree. C.) INITIAL
DAYS AT 49.degree. C.)
CHAIN DP % GLUCOSIDE
% ACID DYNES/CM DYNES/CM
__________________________________________________________________________
*91 3.0
1.0 10% HCl
27.5 23.7
91 3.0
1.0 5% HCl
27.2 25.4
**23 3.0
0.1 10% HC1
27.3 23.5
23 3.0
0.01 10% HCl
29.5 29.0
23 3.0
1.0 20% HCl
27.3 23.4
23 3.0
1.0 20% H.sub.2 SO.sub.4
27.4 25.4
23 3.0
0.1 10% H.sub.2 SO.sub.4
27.4 25.6
23 3.0
1.0 40% H.sub.3 PO.sub.4
27.8 26.7
23 3.0
0.1 40% H.sub.3 PO.sub.4
29.1 21.0
__________________________________________________________________________
*91 is a mixture of nonyl, decyl and undecyl.
**23 is a mixture of dodecyl and tridecyl.
EXAMPLE II
Aluminum Brighteners and Cleaners
______________________________________
LIQUID ALUMINUM BRIGHTENER
(ACID/GLYCOL ETHER/SURFACTANT/SOLVENT)
Raw Materials Percent by Weight
______________________________________
1. Water 12
2. Phosphoric Acid (85%)
49
3. DP 3 glucoside 10
4. Dowanol DPM Glycol Ether
25
5. Orhto-dichlorobenzene
4
100
______________________________________
EXAMPLE III
Household, Automotive, and Industrial Chemical Formulations
______________________________________
LIQUID ALUMINUM CLEANER
(ACIDS/NITRATE/SURFACTANT)
Raw Materials Percent by Weight
______________________________________
1. Phosphoric Acid (85%)
12.0
2. Oxalic Acid 3.0
3. Sodium Nitrate 8.0
4. DP 2.2 glucoside
3.0
5. Water 74.0
100.0
______________________________________
EXAMPLE IV
Dairy Cleaners
______________________________________
LIQUID DAIRY CLEANER (ACIDS/SURFATROPE)
Raw Materials Percent by Weight
______________________________________
1. Water 45
2. Phosphoric Acid (85%)
36
3. Hydrochloric Acid (20.degree. Be)
17
4. DP 1.5 glucoside
2
100
______________________________________
Formulation Notes
1. Use at 4-12% in diluting out depending on scale.
Key Property
Acid milkstone remover.
EXAMPLE V
______________________________________
LIQUID LIGHT DUTY ACID-TYPE
DAIRY CLEANER (ACID/SURFACTANT)
Raw Materials Percent by Weight
______________________________________
1. Gluconic Acid Solution (50%)
20.0
2. DP 2.2 glucoside 10.0
3. Water 70.0
100.0
______________________________________
Key Properties
Excellent soilremoval qualities.
Good compatibility.
High level of detergency (including degreasing ability) and
dispersibility.
Good hydrotopic properties.
EXAMPLE VI
______________________________________
POWDERED CLEANING
COMPOUND (ACID/SULFATE/SURFATROPE)
Raw Materials Percent by Weight
______________________________________
1. DP 1.8 glucoside/xyloside mixture
3
2. Sulfamic Acid 50
3. Sodium Sulfate 47
100
______________________________________
Key Properties
Recommended for dairy use (removal of milk stone) and metal brightening.
Good, efficient formula.
Acid type for dairy use and metal brightening.
EXAMPLE VII
______________________________________
LIQUID ACID BOWL -PORCELAIN CLEANER (ACID/SURFATROPE)
Raw Materials Percent by Weight
______________________________________
1. Water 90.0
2. Hydrochloric Acid
8.0
3. DP 2.2 glucoside
2.0
100.0
______________________________________
Formulation Notes
1. After proper mixing, material may be dyed and perfumed.
2. For removal of iron stains from porcelain, squirt or apply directly.
Let set for 3-5 minutes. Then scrub and rinse. For lighter stains or
general use, dilute 1:1 with water.
3. Handle with carealways use with rubber gloves.
EXAMPLE VIII
______________________________________
LIQUID ACID BOWL
TOILET CLEANER (ACID/SURFATROPE/POLYMER)
Raw Materials Percent by Weight
______________________________________
1. Water 71.0
2. Hydrochloric Acid (20.degree. Be)
28.0
3. Morton E-153 Polymer Emulsion
0.5
4. DP 2.4 glucoside 0.5
100.0
______________________________________
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