U.S. patent number 4,528,144 [Application Number 06/584,184] was granted by the patent office on 1985-07-09 for terpene sulfonate hydrotropes.
This patent grant is currently assigned to Lever Brothers Company. Invention is credited to Eddie N. Gutierrez, Vincent Lamberti.
United States Patent |
4,528,144 |
Gutierrez , et al. |
July 9, 1985 |
Terpene sulfonate hydrotropes
Abstract
p-Menthane-7-sulfonic acid and p-menthane-2-sulfonic acid and
their alkali metal, alkaline earth metal, ammonium and
alkylolammonium salts are disclosed. A method for increasing the
solubility of an only partially water-soluble material is presented
comprising combining the material in water with the salts of
p-menth-6-ene-2-sulfonic acid, p-menth-1-ene-7-sulfonic acid and
their saturated derivatives as hydrotropes.
p-Menth-6-ene-2-sulfonate salts are prepared from .alpha.-pinene
and sulfite or bisulfite salt in the presence of a phase transfer
catalyst under free radical conditions.
Inventors: |
Gutierrez; Eddie N. (Fort Lee,
NJ), Lamberti; Vincent (Upper Saddle River, NJ) |
Assignee: |
Lever Brothers Company (New
York, NY)
|
Family
ID: |
24336245 |
Appl.
No.: |
06/584,184 |
Filed: |
February 27, 1984 |
Current U.S.
Class: |
562/30;
252/363.5; 510/235; 510/427; 510/495; 562/114 |
Current CPC
Class: |
C11D
3/3409 (20130101); C07C 309/00 (20130101) |
Current International
Class: |
C11D
3/34 (20060101); C07C 143/22 () |
Field of
Search: |
;260/503,501.19 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Traynor et al., J. Org. Chem., vol. 44, p. 1557, (1979). .
Starks, J. Amer. Chem. Soc., vol. 93, p. 195, (1971)..
|
Primary Examiner: Chan; Nicky
Attorney, Agent or Firm: Honig; Milton L. Farrell; James
J.
Claims
What is claimed is:
1. p-Menthane-7-sulfonic acid or its alkali metal, alkaline earth
metal, ammonium or alkylolammonium salt.
2. p-Menthane-2-sulfonic acid or its alkali metal, alkaline earth
metal, ammonium or alkylolammonium salt.
3. The compound of claim 1 wherein said salt has a cation component
that is sodium or ammonium.
4. The compound of claim 2 wherein said salt has a cation component
that is sodium or ammonium.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to novel p-menthane sulfonates and their use
as hydrotropes in aqueous compositions.
2. The Prior Art
Many aqueous compositions contain organic components of poor water
solubility. Hydrotropes are formulated into these liquids to
increase the aqueous solubility of the hydrophobic organic
components. Commonly employed hydrotropes include the salts of
toluene, xylene or cumene sulfonates. While these commercial
compounds perform satisfactorily, there is a need for lower cost
alternatives, especially materials not derived from petrochemical
feedstocks.
Among the relatively low-cost renewable raw materials is
turpentine, an extract of pine trees. The .alpha. and
.beta.-pinenes, which are major components of turpentine, when
reacted with pyrosulphuryl chloride yield sulfonate compounds as in
U.S. Pat. No. 2,220,678. Traynor et al, J. Org. Chem., Vol. 44,
1557, 1979, reports that sodium p-menth-6-ene-2-sulfonate (I) can
be formed from the dehydration of the reaction product between
sodium sulfite and the .alpha.-pinene derivative limonene oxide.
This publication further discloses that .beta.-pinene will react
with sodium bisulfite to form sodium p-menth-1-ene-7-sulfonate
(II). The saturated analogs of I and II, i.e., III and IV
respectively, have apparently not yet been reported. Little is
known concerning the utility of these sulfonated pinene
derivatives. U.S. Pat. Nos. 4,224,240 and 4,283,347, however,
mention the possible utility of p-menth-1-ene-7-sulfonate salts as
detergents and surfactants.
It is an object of the present invention to provide nonpetroleum
derived sulfonate salts useful as hydrotropes in aqueous
formulations.
It is a further object of this invention to disclose novel menthane
sulfonate salts.
SUMMARY OF THE INVENTION
p-Menthane-7-sulfonic acid and p-menthane-2-sulfonic acid and their
alkali metal, alkaline earth metal, ammonium and alkylolammonium
salts are hereby disclosed.
Furthermore, a method for increasing the solubility of an only
partially water-soluble material is provided comprising combining
with said material in water a hydrotrope selected from the group
consisting of the alkali metal, alkaline earth metal, ammonium and
alkylolammonium salts of p-menth-6-ene-2-sulfonic acid,
p-menth-1-ene-7-sulfonic acid and their saturated derivatives.
DETAILED DESCRIPTION OF THE INVENTION
Salts of four .alpha.- and .beta.-pinene derived sulfonates have
been identified as effective hydrotropes in aqueous media. These
compounds are identified by their structural formulas below:
##STR1## where M is an alkali metal, alkaline earth metal, ammonium
or alkylolammonium cation.
According to Traynor et al in the J. Org. Chem. article, compound I
could not, by sulfonation, be prepared directly from
.alpha.-pinene. Competitive acid isomerization and hydration to
.alpha.-terpineol was said to occur. These investigators were
forced to prepare compound I by the circuitous route of epoxidizing
.alpha.-pinene. The epoxide was then reacted with sulfite,
acidified by ion-exchange chromatography and dehydrated to obtain
I.
Now it has been found that compound I can be directly prepared from
.alpha.-pinene at atmospheric pressure. The procedure involves
incremental additions of bisulfite or sulfite to aqueous or mixed
aqueous-organic co-solvent, pinene solutions in the presence of air
or a free radical initiator.
Where the ammonium salts of sulfite or bisulfite are employed,
oxygen is the preferable free radical initiator. These reactions
readily occur at atmospheric pressure.
Sodium sulfite or bisulfite reactions are preferably initiated by
organic or inorganic peroxides. Representative of the former type
free radical initiators are tert-butyl peroxide, benzoyl peroxide,
cumene hydroperoxide, tetralin hydroperoxide, isopropylbenzene
hydroperoxide, acetyl peroxide, urea peroxide, methylethyl ketone
peroxide, diisopropyl ether peroxide, diisopropyl peroxy
dicarbonate, and, preferably tert-butyl peroxy benzoate. Inorganic
initiators such as hydrogen peroxide, hydrazine sulphate, sodium
percarbonate and sodium persulphate are also useful. Organic diazo
initiators, such as azobisisobutyronitrile, may similarly be
employed. The free radical initiators are preferably combined with
the sulfite or bisulfite and incrementally added to the .alpha.- or
.beta.-pinene. Generally, from about 0.1 to about 10 mole %, based
on moles pinene, of the free radical initiator are used in the
reaction mixture. Additionally, ultraviolet radiation may serve to
establish the free radical conditions, including when a ultraviolet
photo-initiator is added to the reaction mixture.
Although water can be used as the exclusive solvent, mixed
water-organic co-solvent systems are preferred. The organic
co-solvents should be non-reactive in the process. Such solvents
include alcohols, ethers, glycol ethers, esters, glycols, amines,
amino alcohols and mixtures thereof. A combination of water with
isopropanol is preferred. Mixed aqueous-organic co-solvent systems
may be combined in ratios ranging from 100:1 to 1:100. Preferably,
the ratio of water to co-solvent should range from about 1:4 to
1:1. Water is present to assist the solubilization of the sulfite
or bisulfite salt. Organic co-solvent is present for solubilizing
the pinene. The amount of solvent, either water, organic co-solvent
or mixtures thereof, relative to the pinene reactant will range
from 100:1 to 1:100, respectively.
Reaction temperatures should range from at least 40.degree. C. to
about 300.degree. C. Preferably, the range should be from about
80.degree. C. to 150.degree. C.
Relative molar ratios of sulfite or bisulfite to pinene can range
broadly from about 2:1 to 0.8:1. Preferably, their relative amounts
should range from about 0.95:1 to 1.4:1, sulfite or bisulfite to
pinene, respectively.
Yields of these reactions can be markedly improved where small
amounts of phase transfer catalysts are included. Phase transfer
catalysts are organic soluble quaternary ammonium or phosphonium
salts. The cations assist in the transport of reactive anions from
aqueous to organic phase. The phosphonium or ammonium cations
generally contain at least one hydrophobic moiety such as a C.sub.7
-C.sub.24 alkyl, phenyl or benzyl group. Illustrative of these
materials are tricaprylylmethylammonium chloride and
hexadecyltributylphosphonium bromide. Particularly effective in the
instant invention is benzyltrimethylammonium hydroxide. Their
concentration can vary from 0.01 to 20 mole percent, based on
pinene reactant. Preferably, they are present from 0.5 to 10 mole
percent. Yields are increased by a factor of 10 in the sodium
bisulfite reactions with .alpha.-pinene. Smaller, but still
significant, yield increases are noted where the reactant is
.beta.-pinene.
Ammonium sulfite provides better yields than alkali metal sulfites
or bisulfites. Ammonium bisulfite further improves yields and
permits reaction to occur at lower temperatures, i.e.,
40.degree.-50.degree. C. Aqueous 45% ammonium bisulfite solutions
may be utilized at the commercially available pH of 5.0-5.2 or
adjusted to pH 5.6-6.0 with ammonia. Upon completion of the
reaction, solvent is removed. In the .alpha.-pinene reaction, a
crystalline monohydrate of the trans isomer of compound I is
isolated. Some cis isomer is separated as a resinous dark yellow
material. With ammonium bisulfite solutions of pH above 5.5, the
trans isomer is formed in high specific purity. Trace amounts of
cis isomer form at pH 5.0-5.3. The cis-sulfonate behaves
differently from the trans, the former being susceptible to
autooxidation.
Compounds I and II can be converted to their saturated analogs III
and IV through hydrogenation. A variety of hydrogenation methods
and catalysts can be employed. Both soluble and heterogeneous
catalysts are suitable. Among the heterogeneous variety are
included platinum, palladium, rhodium, ruthenium, iridium and
nickel, each metal being supported on suitable substrates to
facilitate in the uptake of gaseous hydrogen. Particularly
preferred is 5% palladium on charcoal. With this catalyst, hydrogen
is preferably held at about 100 psi. Temperature is maintained
around 80.degree. C. over a 1-5 hour period.
In certain instances, to save expensive catalyst, it becomes
advisable to remove sulphur poisons by pre-treatment with Raney
Nickel. Pre-treatment involves stirring I or II with Raney Nickel
in water at 45.degree.-50.degree. C.
Ammonium and alkylolammonium salts of III and IV may be obtained by
treatment of the corresponding hydrogenated sodium salt by passage
through an ion exchange column and neutralization of the liberated
sulfonic acid with the appropriate base (e.g., ammonium hydroxide
or alkylolamines such as ethanolamine, diethanolamine and
triethanolamine).
Sulfonates III and IV have better storage stability than their
unsaturated precursors. Upon prolonged storage, compounds I and II
developed a yellow color.
Compounds I through IV are here shown to be effective hydrotropes
for solubilizing only partially water-soluble materials into
aqueous systems. Hydrotropes are commercially important, in
particular, as components in aqueous cleaning compositions. These
compositions frequently contain surfactants such as anionic,
nonionic, cationic, zwitterionic or amphoteric actives or mixtures
thereof. These surfactants are set forth in "Surface Active Agents
and Detergents" by Schwartz, Perry & Berch, Vol. II,
Interscience Publishers, Inc., 1958, herein incorporated by
reference. These surfactants are generally employed at from 1% to
50% by weight of the total cleaning formulation.
STABILITY PERFORMANCE EVALUATION
A measure of the effectiveness of a hydrotrope is the amount
required to stabilize a liquid composition undergoing freeze-thaw
cycling.
The procedure for evaluating freeze-thaw stability involves
subjecting a sample in a glass jar to six controlled freeze-thaw
cycles between 0.degree. F. and 70.degree. F. Typically, inspection
of samples is performed after each 1, 2, 3 and 6 cycles. Cycling
time between 0.degree. F. and 70.degree. F. is 24 hours, except
over weekends when temperature is maintained at 70.degree. F. for
48 hours. Six hours are necessary for the temperature in the room
to drop from 70.degree. F. to 0.degree. F. and 4 hours to rise from
0.degree. F. to 70.degree. F. These cycles are thought to simulate
the most extreme conditions for storage and transportation of
hydrotrope containing commercial products during winter months.
The following examples will more fully illustrate the embodiments
of this invention. All parts, percentages and proportions referred
to herein and in the appended claims are by weight unless otherwise
indicated.
EXAMPLE 1
A typical light duty liquid dishwashing formulation is outlined in
Table I. Into this base formulation were incorporated the various
hydrotropes of this invention.
TABLE I ______________________________________ Base Formulation
Components Weight % ______________________________________ Ammonium
linear C.sub.10 -C.sub.15 alkylbenzene sulfonate 24.1 Ammonium
linear C.sub.10 -C.sub.15 alcohol triethoxysulfate 4.7 Lauric
diethanolamide 3.0 Hydrotrope* -- Water to 100
______________________________________ *Identity and amounts as per
following Examples.
EXAMPLE 2
Compounds I, II, III and IV were evaluated for their efficiency as
hydrotropes in freeze-thaw stability tests. These compounds were
incorporated into the base formulation of Table I at several
concentrations to determine the minimum amount hydrotrope needed to
provide adequate stability. Ammonium xylene sulfonate served as the
reference hydrotrope.
TABLE II ______________________________________ Freeze-Thaw
Stability Performance Freeze-thaw Concen- Stability Form- tration
(6 cycles at ulation Hydrotrope Weight % 0-70.degree. F.)
______________________________________ 1 Control Ammonium xylene 8
Stable sulfonate 2 Sodium salt of I 8 Stable 3 Ammonium salt of I 8
Stable 4 Sodium salt of III 8 10-15% gel 5 Ammonium salt of III 8
20% gel 6 Ammonium salt of III 12 12% gel 7 Sodium salt of II 8 10%
gel on top 9 Ammonium salt of II 8 8% gel on top 10 Ammonium salt
of II 9 10% gel on top 11 Ammonium salt of II 10 thin film of gel
12 Ammonium salt of II 12 Stable 13 Sodium salt of IV 8 10-15% gel
14 Ammonium salt of IV 8 15% gel 15 Ammonium salt of IV 10 3-5% gel
16 Ammonium salt of IV 12 Stable
______________________________________
Table II indicates that compounds I-IV all display hydrotrope
properties. They approach ammonium xylene sulfonate in performance.
At the 12% level, compound II and its saturated analog IV provided
stable liquids under freeze-thaw conditions. Compound I provided
equivalent stability to that of the control at 8% active
concentration. The saturated analog, III, was less effective.
EXAMPLE 3
Preparation of (-)Sodium(2S,4R)p-menth-6-ene-2-sulfonate (I)
Method (1)
In a 2 liter, 3-neck Morton flask equipped with stirrer and reflux
condenser, 136 g (1 mole) .alpha.-pinene and one liter
isopropanol:water in the ratio 1:1 were brought to reflux. Sodium
bisulfite, 110 grams (1.06 mole) was added at the rate of 26 grams
per hour along with several additions of 2-3 drops t-butyl
peroxybenzoate. The solution was refluxed for 10 hours.
Thereafter, the solution was evaporated to dryness and the residue
extracted with hot 3A ethanol. Extraction was done three times with
500 ml solvent each time. The combined extracts were evaporated and
the residual solids were then dried in vacuo over phosphorus
pentoxide. A yield of 6% was obtained. The NMR spectrum exhibited
the following peaks: CH.sub.3 (doublet, 0.75 and 0.86.delta.);
CH.sub.3 (singlet, 1.84.delta.); CH.sub.2 and CH (multiplet,
1.00-2.40.delta.); CH (multiplet, 3.23-3.50.delta.); and CH
(multiplet, 5.50-5.62.delta.).
Method (2)
In a 1-liter, 3-neck Morton flask, 130 g of .alpha.-pinene and 10 g
of t-benzyltrimethyl ammonium hydroxide were dissolved in 400 ml of
1:1 isopropanol:water and brought to reflux. Sodium bisulfite, 120
g (1.15 mole) was added at the rate of 10 grams per hour along with
several additions of 2-3 drops t-butyl peroxybenzoate. The solution
was heated for 14 hours. The solvents were then removed by
distillation. The residue was extracted with 3A ethanol. Extracts
were combined and evaporated to dryness. Residues were dried in
vacuo over phosphorus pentoxide. Crude product in the amount of 130
grams was obtained. Karl Fisher analysis indicated the presence of
2.9% water. NMR indicated 58% purity.
EXAMPLE 4
Preparation of (-)Ammonium(2S,4R)p-menth-6-ene-2-sulfonate (I)
Ammonium Sulfite Method
In a 3 liter flask equipped with stirrer, 136 g (1.0 mole)
.alpha.-pinene was dissolved in 800 g isopropanol and 200 g water.
The solution was brought to reflux. Ammonium sulfite monohydrate,
132 g (0.97 mole), was added at the rate of about 0.5 grams per
minute. This solution was then refluxed for 15 hours. Thereafter,
the solution was filtered, evaporated to dryness in vacuo and dried
over phosphorus pentoxide. A product weighing 179 grams was
obtained. NMR analysis indicated 81% purity (62% yield). Karl
Fisher analysis showed 1.6% water present.
EXAMPLE 5
Preparation of (-)Ammonium(2S,4R)p-menth-6-ene-2-sulfonate (I)
Ammonium Bisulfite Method
Into a 500 ml flask equipped with a magnetic stirrer was placed 55
g .alpha.-pinene, 100 ml isopropanol, 150 ml water and 2 g (60%)
benzyltrimethyl ammonium chloride. While stirring, 120 g (45%)
ammonium bisulfite was gradually added. The mixture was stirred for
24 hours at 40.degree.-45.degree. C. Solvents were then removed by
distillation in vacuo. The residue was dissolved in 300 ml
isopropanol. The isopropanol solution was filtered and evaporated
to dryness. A product weighing 93 grams was isolated. Its purity
was 82.5% corresponding to an 81% yield.
EXAMPLE 6
Preparation of (-)Sodium(4S)-p-menth-1-ene-7-sulfonate (II)
Experiment (1)
A mixture of 140 g (1.03 moles) .beta.-pinene and 650 ml water was
heated to reflux in a 2 liter, 3-necked flask equipped with stirrer
and reflux condenser. Then, 125 g (1.2 moles) sodium bisulfite was
added in 25 gram increments per hour along with several additions
of 2-3 drops t-butyl peroxybenzoate. Heat was applied to the
mixture for a period of 71/2 hours. The solution was allowed to
stand overnight. Crystals which had formed were filtered off and
dried in vacuo over phosphorus pentoxide. A total of 89 grams were
collected having 91% purity (NMR analysis) indicating a 32% yield.
The NMR spectrum of the compound included signals at: CH.sub.3
(doublet, 0.75 and 0.85.delta.); CH and CH.sub.2 (multiplets,
1.00-2.40.delta.); CH.sub.2 (singlet, 3.40.delta.); and CH (broad
singlet, 5.80-5.90.delta.).
Experiment (2)
In a 1 liter, 3-neck flask, 70 grams (0.51 mole) .beta.-pinene and
325 ml water was heated to reflux. Sodium bisulfite, 70 grams, was
added at the rate of 13 grams per hour. The solution was refluxed
for 7 hours and allowed to stand overnight.
Excess .beta.-pinene, 3.8 grams, was removed by distillation along
with 100 ml of water. Upon cooling the solution, 106 grams (95%
pure) of product was crystallized. The solution was evaporated to
dryness and residue extracted with 300 ml hot ethanol. Ethanol was
removed by distillation and residual solvent evaporated in vacuo.
The product remained as a residue of 6.7 grams weight and 21.2%
purity. Total yield was 87%.
EXAMPLE 7
Preparation of (-)Ammonium(4S)-p-menth-1-ene-7-sulfonate (II)
Ammonium Sulfite Method
A solution of 136 g (1 mole) .beta.-pinene in 600 g isopropanol and
200 g water was heated to reflux in a 2 liter, 3-neck Morton flask.
Ammonium sulfite monohydrate, 132 g (0.99 mole) was added at the
rate of about 0.5 grams per minute. The solution was refluxed for a
total of 15 hours. Thereafter, the solution was filtered, the
filtrate being evaporated to dryness. There was obtained 156 grams
product having 72.1% purity (47% yield).
The solid product was redissolved in 3A ethanol. Solvent insoluble
residues were filtered off. Filtrate solvent was evaporated to
dryness. Residue product was dried in vacuo over phosphorus
pentoxide. A product was obtained having 74.7% purity by NMR
analysis. Karl Fisher titration indicated 1.5% water.
EXAMPLE 8
Preparation of (-)Ammonium(4S)-p-menth-1-ene-7-sulfonate (II)
Ammonium Bisulfite Method
Into a 1 liter flask equipped with magnetic stirrer were placed 450
ml isopropanol, 240 ml water and 54.4 grams (0.4 mole)
.beta.-pinene. Ammonium bisulfite, 105 grams (45%) was then added
thereto. The mixture was stirred at 40.degree.-45.degree. C. for 22
hours. Thereafter, the solution was evaporated to dryness. Residue
was extracted with methanol. The methanolic solution was filtered,
and the resultant filtrate evaporated to dryness. Obtained were 84
grams product (85.8% purity; 77% yield).
EXAMPLE 9
Preparation of Sodium p-menthane-2-sulfonate (III)
Sodium p-menth-6-ene-2-sulfonate (51.2 g) as prepared in Method 2
was dissolved in 500 ml water and mixed with 22.08 grams of Raney
Nickel catalyst at 45.degree.-50.degree. C. Sulphur poisons were
removed by this pre-treatment.
After 2 hours, the mixture was filtered and transferred to a 1
liter Parr bomb. Twelve grams of 5% palladium on carbon were added
to the mixture. The bomb was sealed and flushed several times with
hydrogen. Hydrogenation was performed at 75.degree.-80.degree. C.
for 3-4 hours at 100 psi. Thereafter, the bomb was cooled, opened
and the solution filtered. Filtrate was evaporated to dryness and
the residue stored over phosphorus pentoxide. The product weighing
42.4 grams, was 95.4% pure by NMR analysis. The NMR spectrum
exhibited signals at: CH.sub.3 (doublet, 1.04 and 1.12.delta.);
CH.sub.2 and CH (multiplet, 1.20-2.50.delta.); CH.sub.3 (multiplet,
1.60.delta.); and CH (multiplet, 3.00-3.20.delta.).
EXAMPLE 10
Preparation of Ammonium p-menthane-2-sulfonate (III)
Sodium-p-methane-2-sulfonate, 35 grams, prepared as in Example 9
was passed through an ion-exchange column. The eluate containing
p-methane-2-sulfonic acid was neutralized with dilute ammonium
hydroxide. The solution was evaporated to dryness and the residue
stored in vacuo over phosphorus pentoxide. The product was 91.7%
pure by NMR analysis.
EXAMPLE 11
Preparation of Sodium(4S)-p-menthane-7-sulfonate (IV)
Sodium(4S)-p-menth-1-ene-7-sulfonate, 75 grams, was dissolved in
500 ml of water. The solution was then placed into a 1 liter Parr
Reactor together with 12 grams (5%) palladium on carbon. The Parr
Reactor was sealed and flushed with hydrogen gas several times to
remove oxygen. Hydrogen was charged to the bomb at 100 psi and the
contents heated to 75.degree.-80.degree. C. for 2 hours.
Subsequently, the bomb was cooled, opened and the solution filtered
to remove catalyst. Solvent was evaporated from the solution and
the residue dried in vacuo over phosphorus pentoxide. Seventy grams
of product with NMR purity of 99.3% was obtained. The NMR spectrum
exhibited signals at: CH.sub.3 (doublet, 1.00 and 1.14.delta.); CH
and CH.sub.2 (multiplet, 1.00-1.30.delta.); and CH.sub.2 (triplet,
centered at 3.07.delta.).
EXAMPLE 12
Preparation of Ammonium(4S)-p-menthane-7-sulfonate (IV)
An aqueous solution of 30 grams sodium (4S)-p-menthane-7-sulfonate,
prepared according to Example 11, was passed through a Permutit
Q101 cationic exchange column to remove sodium ions. The eluate
containing (4S)-p-menthane-7-sulfonic acid was neutralized with
ammonium hydroxide solution. The resultant residue was dried over
phosphorus pentoxide. Obtained were 29 grams product of 99.9%
purity.
The foregoing description and examples illustrate selected
embodiments of the present invention and in light thereof
variations and modifications will be suggested to one skilled in
the art, all of which are in the spirit and purview of this
invention.
* * * * *