Process for the preparation of secondary alkyl sulfate-containing surfactant compositions

This invention relates to a process for preparing secondary alkyl sulfate-containing surface active compositions substantially free of unreacted organic matter and water, which process comprises: a) sulfating a mixture of a detergent range olefin having from about 8 to about 22 carbon atoms and a detergent range alcohol having from about 8 to about 22 carbon atoms with a sulfating agent, b) neutralizing the product of step a) with a base dispersed in a nonionic surfactant having a boiling point higher than that of said detergent range olefin and its corresponding secondary alcohol, c) saponifying the product of step b), d) passing the product of step c) through a thin film evaporator to evaporate unreacted organic matter from said product and recovering said product.

FIELD OF THE INVENTION 
This invention relates to a process for the preparation of secondary alkyl 
sulfate-containing surfactant compositions. 
BACKGROUND OF THE INVENTION 
This invention provides a process for preparing surfactant compositions 
containing secondary alkyl sulfates which are substantially free of 
unreacted organic matter (UOM), and which are substantially free of water, 
thus making the compositions substantially free of inert diluents. 
In conventional practice, secondary alkyl sulfates have been derived from 
both olefins and alcohols using sulfuric acid, followed by neutralization 
of the intermediate secondary alkyl sulfuric acid with the appropriate 
base, although olefin-derived secondary alkyl sulfates have not been as 
extensively investigated as alcohol-derived secondary alkyl sulfates. The 
process is complicated by incomplete reaction of the starting olefin and 
alcohol and by formation of dialkyl sulfates which saponify during the 
neutralization step, noted above, to equal molar amounts of secondary 
alkyl sulfate and secondary alcohol. 
Unreacted olefin and secondary alcohol, which can amount to 50% by weight 
or more of the starting olefin, are generally removed from the secondary 
alkyl sulfate by a process of extraction with an organic solvent as 
described in U.S. Pat. No. 4,175,092. The extraction process can be 
complicated by the formation of undesirable emulsions and gels as well as 
by the dissolution of some of the extracting solvent in the aqueous 
secondary alkyl sulfate phase. Extracting solvents frequently have 
objectionable odors and must be removed from the aqueous surfactant 
solution, an operation which can be accompanied by severe foaming 
difficulties. When extraction is complete, the concentration of secondary 
alkyl sulfate in water is generally in the range of 20-40% by weight (F. 
Asinger, Mono-Olefins: Chemistry and Technology, 1968, pp. 689-694). 
It would therefore be advantageous to have a process for preparing 
surfactant compositions utilizing secondary alkyl sulfates as the anionic 
component which eliminates the problems associated with solvent extraction 
for removal of the non-surface active organic material and which produces 
a product free of water, thus allowing maximum handling and blending 
flexibility. 
An integrated process for preparing surfactant compositions has been found 
in which secondary alkyl sulfates derived from a mixture of olefins and 
alcohols can be generated in a manner such that the non-surface active 
material can be easily stripped from the secondary alkyl sulfates while at 
the same time producing a surfactant and/or detergent composition which is 
particularly useful for household applications. 
It is therefore an object of this invention to prepare surface active 
compositions containing secondary alkyl sulfates derived from a mixture of 
olefins and alcohols, which are substantially free of unreacted olefin and 
substantially free of water, in a nonionic surfactant having a boiling 
point higher than the olefin reaction and its corresponding secondary 
alcohol. In the present invention, a surface active composition is 
prepared by reacting a mixture of one or more detergent range alcohols and 
one or more detergent range olefins with a sulfating agent, removing 
excess sulfating agent, neutralizing and saponifying the mixture in the 
presence of a base dispersed in a nonionic surfactant having a boiling 
point higher than the detergent range olefin and its corresponding 
secondary alcohol, and then passing the mixture through a falling film or 
wiped film evaporator to strip unreacted organic matter from the mixture, 
thereby producing a secondary alkyl sulfate-containing detergent 
composition which is anhydrous and substantially free of inert diluents. 
SUMMARY OF THE INVENTION 
This invention relates to a process for preparing secondary alkyl 
sulfate-containing surface active compositions substantially free of 
unreacted organic matter and water, which process comprises: a) sulfating 
a mixture of a detergent range alcohol having from about 8 to about 22 
carbon atoms and a detergent range olefin having from about 8 to about 22 
carbon atoms with a sulfating agent, and, optionally, removing excess 
sulfuric acid by water wash, b) neutralizing the product of step a) with a 
base dispersed in a nonionic surfactant having a boiling point higher than 
said detergent range olefin and its corresponding secondary alcohol, c) 
saponifying the product of step b), d) passing the product of step c) 
through a thin film evaporator to evaporate unreacted organic matter from 
said product and recovering said product. The unreacted organic matter 
evaporated from the product can be recycled, if desired.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
This invention relates to secondary alkyl sulfate-containing surface active 
compositions substantially free of unreacted organic matter and water 
prepared by a process which comprises sulfation of a mixture of a 
detergent range alcohol and a detergent range olefin by adding a sulfating 
agent followed by water washing to remove excess sulfating agent, 
neutralization with a base dispersed in a nonionic surfactant having a 
boiling point higher than that of said detergent range olefin and its 
corresponding secondary alcohol, saponification, and then distillation of 
unreacted organic matter, thus generating a surfactant composition 
comprising secondary alkyl sulfate and nonionic surfactant. 
As used herein, the phrase "substantially free of unreacted organic matter 
and water" refers to detergent compositions which contain less than about 
10 percent by weight, preferably less than about 5 percent by weight, of 
unreacted organic matter and less than about 5 percent by weight, 
preferably less than about 2 percent by weight, of water. 
The detergent range olefins which are sulfated in step a) of the instant 
invention are olefins containing from about 8 to about 22 carbon atoms. 
These olefins can be alpha olefins or internal olefins and they may be 
linear or branched, but are preferably linear or lightly branched. Single 
cut olefins or mixtures of olefins may also be used. In a particularly 
preferred embodiment, the olefin contains from about 12 to about 18 carbon 
atoms. 
Preferred for use as olefin reactants for the practical reason of 
availability are the commercial olefin products in the C.sub.8 to C.sub.22 
range. While commercial production of such olefins may be carried out by 
the cracking of paraffin wax, commercial production is more commonly 
accomplished by the oligomerization of ethylene using procedures well 
known in the art. The resulting oligomerization products are substantially 
of linear structure and thus products are substantially of linear 
structure. Commercial olefin products manufactured by ethylene 
oligomerization are marketed in the United States by Shell Chemical 
Company under the trademark Neodene and by Ethyl Corporation as Ethyl 
Alpha-Olefins. Specific procedures for preparing suitable linear olefins 
from ethylene are described in U.S. Pat. Nos. 3,676,523, 3,686,351, 
3,737,475, 3,825,615 and 4,020,121, the teachings of which are 
incorporated herein by reference. While most of such olefin products are 
comprised largely of alpha-olefins, higher linear internal olefins are 
also commercially produced, for example, by the 
chlorination-dehydrochlorination of paraffins, by paraffin 
dehydrogenation, and by isomerization of alpha-olefins. Linear internal 
olefin products in the C.sub.8 to C.sub.22 range are marketed by Shell 
Chemical Company and by Liquichemica Company. These commercial products, 
whether predominantly internal or alpha-olefins typically contain about 70 
percent by weight or more, most often about 80 percent by weight or more, 
linear mono-olefins in a specified carbon number range (e.g., C.sub.10 to 
C.sub.12, C.sub.11 to C.sub.15, C.sub.12 to C.sub.13, C.sub.15 to 
C.sub.18, etc.) the remainder of the product being olefin of other carbon 
number or carbon structure, diolefins, paraffins, aromatics, and other 
impurities resulting from the synthesis process. Olefins marketed in the 
United States in the C.sub.12 to C.sub.18 range are considered most 
preferred for use in the instant invention. 
The detergent range alcohols which are suitable for use in the present 
invention are alcohols containing from about 8 to about 22 carbon atoms. 
Acyclic aliphatic alcohols having from about 9 to about 18 carbon atoms 
form a preferred class of reactants, particularly the secondary alcohols, 
although primary alcohols can also be utilized. As a general rule, the 
carbon chains of the alcohols may be of either branched or linear 
(straight-chain) structure, although alcohol reactants in which greater 
than about 50 percent, more preferably greater than about 70 percent and 
most preferably greater than about 90 percent of the molecules are of 
linear (straight-chain) carbon structure are preferred. In large part, 
such preferences relate more to the utility and value of the products than 
to the operability or performance of the process of the invention. 
Specific examples of branched chain or secondary alcohols include 
2-hexadecanol, hexadecanols, tetradecanols and the like. Commercially 
available mixtures of secondary alcohols prepared via the oxidation of 
paraffins, and from internal olefins and alpha-olefins mixtures via 
sulfation and hydrolysis reactions are also suitable. Specific examples of 
commercially available secondary alcohol mixtures include Tergitol 15, a 
trademark of and sold by Union Carbide, in which the main components are 
C.sub.11 to C.sub.15 compounds; Tergitol 45, in which the main components 
are C.sub.14 to C.sub.15 compounds; Softanol 24, a trademark of and sold 
by Nippon Shokubai Kagaku Kogyo Co., Ltd., in which the main components 
are C.sub.12 to C.sub.14 compounds, and the like. 
Specific examples of suitable primary straight-chain monohydric aliphatic 
alcohols include dodecanol, pentadecanol, octadecanol, eicosanol and the 
like. Mixtures of alcohols are also suitable for purposes of the invention 
and are often preferred for reasons of commercial availability. 
Commercially available mixtures of primary monoalcohols prepared via the 
oligomerization of ethylene and the hydroformylation or oxidation and 
hydrolysis of the resulting higher olefins are particularly preferred. 
Specific examples of commercially available alcohol mixtures in the 
C.sub.9 to C.sub.20 range include the NEODOL Alcohols, trademark of and 
sold by Shell Chemical Company, including mixtures of C.sub.9, C.sub.10 
and C.sub.11 alcohols (NEODOL 91 Alcohol), mixtures of C12 and C13 
alcohols (NEODOL 23 Alcohol), mixtures of C.sub.12, C.sub.13, C.sub.14, 
and C.sub.15 alcohols (NEODOL 25 Alcohol), and mixtures of C 14 and C 15 
alcohols (NEODOL 45 Alcohol); the ALFOL Alcohols, trademark of and sold by 
Vista Chemical Company, including mixtures of C.sub.10 and C.sub.12 
alcohols (ALFOL 1012), mixtures of C.sub.12 and C14 alcohols (ALFOL 1214), 
mixtures of C.sub.16 and C.sub.18 alcohols (ALFOL 1618), and mixtures of 
C.sub.16, C.sub.18 and C.sub.20 alcohols (ALFOL 1620); the E Alcohols, 
trademark of and sold by Ethyl Chemical Company, including mixtures of 
C.sub.10 and C.sub.12 alcohols (E 1012 ), mixtures of C.sub.12 and 
C.sub.14 alcohols (E 1214), and mixtures of C.sub.14, C.sub.16, and 
C.sub.18 alcohols (E 1418); and the TERGITOL-L Alcohols, trademark of 
and sold by Union Carbide Corporation, including mixtures of C 12, C13, 
C14, and C15 alcohols (TERGITOL 125). Also very suitable are the 
commercially available alcohols prepared by the reduction of naturally 
occurring fatty esters, for example, the CO and TA products of Procter and 
Gamble Company and the TA alcohols of Ashland Oil Company. 
As used herein, the term "alcohol reactant" is also intended to include 
alcohol ethoxylates such as, for example, ethoxylated fatty alcohols, 
preferably linear primary or secondary monohydric alcohols with about 
C.sub.8 to about C.sub.22, preferably about C.sub.12 to about C.sub.15, 
alkyl groups and an average of about 0.5 to about 15, preferably about 0.5 
to about 9, moles of ethylene oxide per mole of alcohol, and ethoxylated 
alkylphenols with C.sub.8 to about C.sub.12 alkyl groups, preferably about 
C.sub.8 to about C.sub.10 alkyl groups and an average of about 1 to about 
12 moles of ethylene oxide per mole of alkylphenol. 
In a preferred embodiment, the alcohol reactant is a primary alcohol, 
preferably selected from the group consisting of dodecanol, tridecanol and 
their corresponding low molecular weight ethoxylates and mixtures thereof, 
with a blend of C.sub.12 to C.sub.13 alcohols to which one mole of 
ethylene oxide per mole of alcohol has been added being particularly 
preferred. The sulfating agents suitable for use in sulfating the mixture 
of detergent range olefins and detergent range alcohols in step a) include 
those compounds capable of forming the carbon to oxygen to sulfur bonds 
necessary for the formation of an alkyl sulfate. These sulfating agents 
are known in the art and typically include sulfuric acids and sulfuric 
acid salts. In a preferred embodiment, the sulfating agent is concentrated 
sulfuric acid. The concentrated sulfuric acid typically has a 
concentration of from about 75 percent by weight to about 100 percent by 
weight, preferably from about 85 percent by weight to about 98 percent by 
weight, in water. Suitable amounts of sulfuric acid are generally in the 
range of from about 0.3 moles to about 1.3 moles of sulfuric acid per mole 
of olefin and alcohol and from about 0.4 moles to about 1.0 mole of 
sulfuric acid per mole of olefin and alcohol. 
The sulfation reaction in step a) is suitably carried out at temperatures 
in the range of from about -20.degree. C. to about 50.degree. C., 
preferably from about 5.degree. C. to about 40.degree. C., and at 
pressures in the range of from about 1 atmosphere to about 5 atmospheres, 
preferably from about 1 atmosphere to about 2 atmospheres, and more 
preferably, about 1 atmosphere. Suitable residence times for the sulfation 
reaction range from a few minutes to several hours, preferably from about 
2 minutes to about 10 hours and more preferably, from about 5 minutes to 
about 3 hours. 
The sulfation reaction may be illustrated by the following equation: 
##STR1## 
wherein R is an alkyl group having from about 6 to about 20 carbon atoms. 
The products of the sulfation reaction are primarily monoalkyl sulfuric 
acids and dialkyl sulfates along with unreacted olefin, unreacted alcohol, 
unreacted sulfuric acid and water. 
In one embodiment, the sulfation product of step a) may, prior to the 
contact with a base dispersed in a nonionic surfactant in step b) or prior 
to neutralization, be subjected to deacidification for the partial or 
substantially complete removal of the unconverted sulfuric acid or any 
unreacted sulfating agent. Suitable deacidification procedures include 
washing the sulfation reaction product with water or an acid such as 
sulfuric acid having a concentration of from about 75 percent by weight to 
about 90 percent by weight, preferably from about 80 percent by weight to 
about 85 percent by weight, in water. The deacidification is typically 
carried out at the same temperature at which the sulfation reaction in 
step a) is carried out. However, the present invention may be carried out 
with or without deacidification. For example, the deacidification step is 
omitted when the sulfuric acid to olefin and alcohol molar ratio is less 
than 0.8 mole of acid/mole of olefin and alcohol, preferably 0.6 mole of 
acid/mole of olefin and alcohol or less. 
Following the sulfation reaction in step a) and optional deacidification, 
the sulfation product, i.e., monoalkyl and dialkyl sulfates, is contacted 
with a base dispersed in a nonionic surfactant in order to neutralize the 
alkyl sulfuric acid portion of the sulfation product of step a) to form 
the corresponding sulfuric acid salts. 
The neutralization reaction is accomplished using one or more bases such as 
ammonium or alkali metal or alkaline earth metal hydroxides or carbonates 
or bicarbonates dispersed in a nonionic surfactant. Suitable bases include 
sodium hydroxide, sodium carbonate, potassium hydroxide, calcium hydroxide 
and the like, with sodium hydroxide or potassium hydroxide being the 
preferred base. The amount of base added to the nonionic surfactant is 
based on the acidity of the monoalkylsulfuric acid phase after water 
washing and is suitably in the range of from about 1.1 meq/meq acid 
(milliequivalent of base per milliequivalent of acid) to about 2.5 meq/meq 
acid, preferably from about 1.3 meq/meq acid to about 1.9 meq/meq acid. 
The neutralization procedure can be carried out over a wide range of 
temperatures and pressures. Typically, the neutralization procedure is 
carried out at a temperature in the range of from about 20.degree. C. to 
about 65.degree. C., and a pressure in the range of from about 1 
atmosphere to about 2 atmospheres. The neutralization time is typically in 
the range of from about 0.5 hours to about 1.0 hours. 
The nonionic surfactant utilized in the neutralization reaction in step b) 
must have a higher boiling point than the boiling point of the detergent 
range olefin reactant which is sulfated in step a) and its corresponding 
secondary alcohol. The diluent must also be a liquid or at least be 
sufficiently flowable to pass through a thin film evaporator. Suitable 
nonionic surfactants include alkyl ethoxylates and alkylaryl ethoxylates. 
In a preferred embodiment, the nonionic surfactant is an alcohol 
ethoxylate. The general class of alcohol ethoxylates useful in the 
neutralization reaction in step b) as diluent is characterized by the 
chemical formula R.sub.1 --O--(CH.sub.2 --CH.sub.2 O).sub.n --H, wherein 
R.sub.1 is a straight-chain or branched-chain alkyl group having in the 
range of from about 8 to about 18 carbon atoms, preferably from about 12 
to about 18 carbon atoms, or an alkylaryl group having an alkyl moiety 
having from about 8 to about 12 carbon atoms, and n represents the average 
number of oxyethylene groups per molecule and is in the range of from 
about 1 to about 15, preferably from about 2 to about 12 and more 
preferably from about 2 to about 9. The alkyl group can have a carbon 
chain which is straight or branched, and the ethoxylate component can be a 
combination of straight-chain and branched molecules. Preferably, about 75 
percent of the R groups in the instant composition are straight-chain. It 
is understood that R can be substituted with any substituent which is 
inert. Ethoxylates within this class are conventionally prepared by the 
sequential addition of ethylene oxide to the corresponding alcohol (ROH) 
in the presence of a catalyst. 
The alcohol ethoxylate is preferably derived by ethoxylation of primary or 
secondary, straight-chain or branched alcohols. Suitably, the alcohols 
have from about 8 to about 18 carbon atoms, preferably from about 9 to 
about 15 carbon atoms, and more preferably from about 12 to about 15 
carbon atoms. The most common ethoxylates in this class and the ones which 
are particularly useful in this invention are the primary alcohol 
ethoxylates, i.e., compounds of formula I in which R is an alkyl group and 
the --O--(CH.sub.2 --CH.sub.2 O).sub.n --H ether substituent is bound to a 
primary carbon of the alkyl group. 
Alcohols which are suitable to form alcohol ethoxylates for use in the 
present process include coconut fatty alcohols, tallow fatty alcohols, and 
the commercially available synthetic long-chain fatty alcohol blends, e.g. 
. the C.sub.12 to C.sub.15 alcohol blends available as NEODOL 25 Alcohol 
(a registered trademark of product manufactured and sold by Shell Chemical 
Company), the C.sub.12 to C.sub.14 alcohol blends available as Tergitol 24 
L (a registered trademark of product manufactured and sold by Union 
Carbide Corporation), and the C.sub.12 to C.sub.13 alcohol blends 
available, for example, as NEODOL 23 Alcohol (Shell). 
Suitable alcohol ethoxylates can be prepared by adding to the alcohol or 
mixture of alcohols to be ethoxylated a calculated amount, e.g., from 
about 0.1 percent by weight to about 0.6 percent by weight, preferably 
from about 0.1 percent by weight to about 0.4 percent by weight, based on 
total alcohol, of a strong base, typically an alkali metal or alkaline 
earth metal hydroxide such as sodium hydroxide or potassium hydroxide, 
which serves as a catalyst for ethoxylation. The resulting mixture is 
dried, as by vapor phase removal of any water present, and an amount of 
ethylene oxide calculated to provide from about 0.5 mole to about 15 moles 
of ethylene oxide per mole of alcohol is then introduced and the resulting 
mixture is allowed to react until the ethylene oxide is consumed. A 
precalculated amount of ethylene oxide is added to achieve the desired 
level of ethoxylation. This amount can be readily determined by one of 
ordinary skill in the art with a minimal amount of experimentation. After 
the calculated amount of ethylene oxide has been added, the consumption of 
ethylene oxide can then be monitored by the decrease in reaction pressure. 
The ethoxylation is typically conducted at elevated temperatures and 
pressures. Suitable reaction temperatures range from about 120.degree. C. 
to about 220.degree. C. with the range of from about 140.degree. C. to 
about 160.degree. C. being preferred. A suitable reaction pressure is 
achieved by introducing to the reaction vessel the required amount of 
ethylene oxide which has a high vapor pressure at the desired reaction 
temperature. For considerations of process safety, the partial pressure of 
the ethylene oxide reactant is preferably limited, for instance, to less 
than about 60 psig, and/or the reactant is preferably diluted with an 
inert gas such as nitrogen, for instance, to a vapor phase concentration 
of about 50 percent or less. The reaction can, however, be safely 
accomplished at greater ethylene oxide concentration, greater total 
pressure and greater partial pressure of ethylene oxide if suitable 
precautions, known to the art, are taken to manage the risks of explosion. 
A total pressure of between about 40 and 110 psig, with an ethylene oxide 
partial pressure between about 15 and 60 psig, is particularly preferred, 
while a total pressure of between about 50 and 90 psig, with an ethylene 
oxide partial pressure between about 20 and 50 psig, is considered more 
preferred. The pressure serves as a measure of the degree of the reaction 
and the reaction is considered to be substantially complete when the 
pressure no longer decreases with time. 
It should be understood that the ethoxylation procedure serves to introduce 
a desired average number of ethylene oxide units per mole of alcohol 
ethoxylate. For example, treatment of an alcohol mixture with 3 moles of 
ethylene oxide per mole of alcohol serves to effect the ethoxylation of 
each alcohol molecule with an average of 3 ethylene oxide moieties per 
mole alcohol moiety, although a substantial proportion of alcohol moieties 
will become combined with more than 3 ethylene oxide moieties and an 
approximately equal proportion will have become combined with less than 3. 
Specific nonionic surfactant compounds which can be used in the composition 
of the present invention include ethoxylated fatty alcohols, preferably 
linear primary or secondary monohydric alcohols with about C.sub.8 to 
about C.sub.18, preferably about C.sub.12 to about C.sub.15, alkyl groups 
and an average of about 0.5 to about 15, preferably about 0.5 to about 9, 
moles of ethylene oxide per mole of alcohol, and ethoxylated alkylphenols 
with C.sub.8 to about C.sub.12 alkyl groups, preferably about C.sub.8 to 
about C.sub.10 alkyl groups and an average of about 1 to about 12 moles of 
ethylene oxide per mole of alkylphenol. 
A preferred class of nonionic ethoxylates is represented by the 
condensation product of a fatty alcohol having from about 12 to about 15 
carbon atoms and from about 2 to about 12 moles of ethylene oxide per mole 
of fatty alcohol. Suitable species of this class of ethoxylates include: 
the condensation product of C.sub.12 -C.sub.15 oxo-alcohols and 7 moles of 
ethylene oxide; the condensation product of narrow cut C.sub.14 -C.sub.15 
oxo-alcohols and 7 or 9 moles of ethylene oxide per mole of fatty 
(oxo)alcohol; the condensation of a narrow cut C.sub.12 -.sub.13 fatty 
(oxo)alcohol and 6.5 moles of ethylene oxide per mole of fatty alcohol. 
The fatty oxo-alcohols, while primarily linear, can have, depending upon 
the processing conditions and raw material olefins, a certain degree of 
branching. A degree of branching in the range from 15% to 50% by weight is 
frequently found in commercially available oxo-alcohols. Additionally, 
secondary alcohols may also be present. 
The amount of nonionic surfactant in step b) in the present invention is 
such that it is sufficient to disperse in the desired base and such that 
the amount of nonionic surfactant in the final surfactant composition is 
from about 25 percent by weight to about 90 percent by weight, preferably 
from about 30 percent by weight to about 60 percent by weight, and more 
preferably from about 40 percent by weight to about 50 percent by weight. 
Typically, the amount of nonionic surfactant utilized in step b) is in the 
range of from about 35 percent by weight to about 60 percent by weight, 
and preferably from about 40 percent by weight to about 50 percent by 
weight, basis the weight of the final product. 
The product may be de-salted following the neutralization reaction. A 
de-salting treatment may be used in place of or in addition to the 
de-acidification described above depending on the extent of the 
de-acidification. Desalting is typically carried out by using an excess of 
base in the neutralization reaction which neutralizes the unreacted 
sulfuric acid to form the inorganic salts thereof in addition to 
neutralizing the secondary alkyl sulfuric acids. For example, sodium 
sulfate may be present when sodium hydroxide is the base in the 
neutralization. These inorganic salts may be removed as a separate phase 
by known methods such as, for example, filtration. However, removal of the 
inorganic salts in this manner results in a loss of sulfuric acid, since 
the organic salts thereof are normally discarded. For this reason, removal 
of unreacted sulfuric acid by deacidification via water washing following 
sulfation is preferred. 
Following the contact in step b) of the sulfation product of step a) with a 
base dispersed in a nonionic surfactant to effect neutralization, the 
product of step b), is heated in step c) to a temperature in the range of 
from about 70.degree. C. to about 115.degree. C. in order to effect 
saponification or hydrolysis of the dialkyl sulfates to form equimolar 
amounts of alkyl sulfuric acid salts and secondary alcohols. Suitably, the 
neutralization and saponification reactions take place by the addition of 
one or more bases such as amines or ammonium or alkali metal or alkaline 
earth metal hydroxides, carbonates or bicarbonates dispersed in a nonionic 
surfactant, with sodium hydroxide being the preferred base. 
The saponification reaction can be carried out over a wide range of 
temperatures and pressures. The saponification procedure is typically 
carried out at a temperature in the range of from about 70.degree. C. to 
about 115.degree. C., preferably from about 80.degree. C. to about 
105.degree. C., and a pressure of from about 1 atmosphere to about 2 
atmospheres. The saponification reaction is generally carried out over a 
time period ranging from about 0.25 hours to about 5.0 hours. 
The neutralization and saponification reactions may be illustrated by the 
following equations: 
##STR2## 
wherein R.sub.2 is an alkyl group having from about 1 to about 20 carbon 
atoms. 
Following the neutralization and saponification reactions in steps b) and 
c), the product of step c) is passed through a thin film evaporator in 
order to recover unreacted olefin and secondary alcohols. The thin film 
evaporator may suitably be a wiped film evaporator or a falling film 
evaporator. If desired, the secondary alcohol can be separated from 
unreacted olefin by means recognized by those skilled in the art such as, 
for example, distillation. 
After the product is passed through an evaporator to remove unreacted 
organic matter, the resulting product is recovered. The product contains 
primarily secondary alkyl sulfate and nonionic surfactant, at least about 
70 percent by weight to about 95 percent by weight, preferably about 85 
percent by weight to about 95 percent by weight. The product generally 
contains from about 5 percent by weight to about 75 percent by weight, 
preferably from about 20 percent by weight to about 60 percent by weight 
secondary alkyl sulfate, and from about 25 percent by weight to about 90 
percent weight, preferably from about 30 percent by weight to about 60 
percent by weight nonionic surfactant. Some residual level of sodium 
sulfate remains. The product typically contains less than about 12 percent 
by weight, preferably less than about 9 percent by weight, sodium sulfate. 
The weight ratio of secondary alkyl sulfate to nonionic surfactant in the 
resulting surfactant composition can vary widely with weight ratios in the 
range of from about 0.1:1 to about 4:1, preferably from about 1:3 to about 
3:1, and more preferably, from about 1:1 to about 2:1. 
Typically, the compositions of the invention have a surface active material 
content after thin film evaporation, i.e. the percentage of secondary 
alkyl sulfate and primary alkyl sulfate plus the percentage of nonionic 
surfactant, of at least about 70 percent by weight, preferably at least 
about 85 percent by weight, and more preferably, at least about 90 percent 
by weight of said composition. The compositions also contain from about 5 
percent by weight to about 10 percent by weight sodium sulfate. 
The surfactant compositions of the invention can be utilized in a variety 
of detergent applications. The surfactant compositions can be adsorbed at 
relatively low temperatures, about 85.degree. C. or less, onto solid 
detergent materials such as, for example, sodium carbonate, in order to 
form dry detergent powders. The surfactant compositions can also be added 
to water or vice versa in order to form liquid detergents. 
When an alcohol ethoxylate is used as the nonionic surfactant in the 
instant process, the surfactant compositions prepared may suitably be a 
detergent formulation of the general sort as is conventionally made of 
ethoxylate-containing surfactant compositions. Commonly, but not 
necessarily, such a formulation would contain the surfactant composition 
of the instant invention in a quantity between about one and about fifty 
percent by weight. The remainder of such formulation would be comprised of 
one or more additional components which are conveniently used in 
ethoxylatecontaining formulations, such as, for example, water; detergent 
builders; sequestering agents; coloring agents; enzymes; perfumes; and 
other nonionic and anionic as well as cationic detergent active materials. 
The ranges and limitations provided in the instant specification and claims 
are those which are believed to particularly point out and distinctly 
claim the present invention. It is, however, understood that other ranges 
and limitations which perform substantially the same function in 
substantially the same manner to obtain the same or substantially the same 
result are intended to be within the scope of the instant invention as 
defined by the instant specification and claims. 
The invention will be described below by the following examples which are 
provided for purposes of illustration and are not to be construed as 
limiting the invention. 
Illustrative Embodiments 
EXAMPLE 1 
Preparation of Surfactant Compositions 
Sulfation 
To a round-bottomed flask equipped with a paddle stirrer, thermometer, and 
addition funnel topped with a nitrogen blanket was added 250.00 grams of 
C.sub.14/17 internal olefin (C.sub.14, 3.4% weight (%w); C.sub.15, 41.8%w; 
C.sub.16, 36.5%w; C.sub.17, 15.3%w; and C.sub.18, 3.0%w) and 26.96 grams 
of 2-hexadecanol. After cooling to 17.degree. -19.degree. C., 76.70 grams 
of 95% sulfuric acid was added at such a rate that the temperature was 
maintained at 17.degree. -19.degree. C. When acid addition was complete, 
acidity was monitored by titration until it remained essentially constant. 
Neutralization/Saponification 
The mixture from the sulfation above (350.48 grams) was added to a stirred 
mixture of 140 grams of Neodol 23-6.5 alcohol ethoxylate (NEODOL is a 
trademark of Shell Chemical Company) and 89.24 grams of 50 percent by 
weight (%w) sodium hydroxide, at 24.degree. -61.degree. C. over a period 
of eighteen minutes. The alkalinity was 0.61 milliequivalents/gram (meq/g) 
after neutralization. 
After neutralization, the mixture was heated with stirring to reflux 
(approximately 105.degree. C.) and held at reflux for about one hour. 
A sample after about one hour at reflux gave an anionic concentration of 
91.23 meq/100 grams. The alkalinity after one hour was 0.26 meq/gram. 
Thin Film Evaporation 
To a wiped film evaporator at 140.degree. -141.degree. C. and about 50 mm 
Hg pressure, was added 548.63 grams of the neutralized/saponified product 
from the above step. The wiped film evaporator distillation required 
twenty-five minutes and produced 470.43 grams of bottoms product. The 
distillate was a mixture of water and unreacted organic matter, amounting 
to 59.80 g. 
456.59 Grams of the bottoms produced above in the first wiped film 
evaporator distillation was added to a wiped film evaporator at 
141.degree. -142.degree. C. and about 30 mm Hg pressure over a period of 
about forty minutes. 350.01 Grams of bottoms product and 96.57 g of water 
and unreacted organic matter distillate were produced. 
The bottoms product was redistilled through the wiped film evaporator at 
140.degree. C. and a vacuum of 0.25-0.4 mm Hg two times until anionic 
reached a concentration of 138.8 meq/100 g or 47.7%w. 
EXAMPLE 2 
Preparation of Surfactant Compositions 
Sulfation 
The reaction was carried out as described in Example 1 above with 76.88 
grams of 95% sulfuric acid added to a well stirred mixture of 250.00 grams 
of C.sub.14/17 internal olefin (C.sub.14, 3.4% weight (%w); C.sub.15, 
41.8%w; C.sub.16, 36.5%w; C.sub.17, 15.3%w; and C.sub.18, 3.0%w) and 26.96 
grams of Neodol 23-1 alcohol ethoxylate at 17.degree. -25.degree. C. When 
acid addition was complete, acidity was monitored by titration until it 
remained essentially constant. 
Neutralization/Saponification 
The mixture from the sulfation above (350.33 grams) was added to a stirred 
mixture of 96.53 grams of 50%w NAOH and 140.00 of Neodol 23-6.5 alcohol 
ethoxylate at 27.degree. -60.degree. C. 
After neutralization, the mixture was heated with stirring to about 
100.degree. -109.degree. C. and held until anionic titration held 
essentially constant at about 84.8 meq/100g or 28.8 % w anionic. 
Thin Film Evaporation 
To a wiped film evaporator at 139.degree. -140.degree. C. and about 47-49 
mm Hg was added 547.25 grams of the neutralization/saponification product 
from above. The wiped film evaporator distillation required 39 minutes and 
produced 466.54 grams of bottoms product. The distillate was a mixture of 
water and unreacted organic matter, amounting to 59.23 grams. The wiped 
film evaporator distillation of the bottoms product was carried out two 
additional times at 140.degree. -141.degree. C. and vacuums of about 1.2 
and about 0.2-0.35 mm Hg, respectively, producing 89.05 grams of product 
having an anionic content of about 40%w (116.3 meq/100g). 
EXAMPLE 3 
Preparation of Surfactant Compositions 
Sulfation 
The reaction was carried out as described in Example 1 above with 12.88 
grams of 95% sulfuric acid added to a well stirred mixture of 50.00 grams 
of 2-hexadecanol and 50.00 grams of n-heptane at 25.degree. -30.degree. C. 
When acid addition was complete, acidity was monitored by titration until 
it remained essentially constant. 
Neutralization/Saponification 
The mixture from the sulfation above (103.27 grams) was added to a stirred 
mixture of 15.70 grams of 50%w NAOH and 96.40 grams of Neodol 23-6.5 at 
31.degree. -40.degree. C. 
After neutralization, the mixture was heated with stirring to about 
89.degree. -91.degree. C. for about 1-hr. after which a Dean-Stark trap 
was added to the reaction flask and water was removed by azeotropic 
distillation. Anionic titration gave 36.2 meq/100 g or 12.5%w anionic. 
Thin Film Evaporation 
To a wiped film evaporator at about 141.degree. C. and about 0.26-0.40 mm 
Hg was added 167.23 grams of the neutralization/saponification product 
from above. The wiped film evaporator distillation required 21 minutes and 
produced 119.32 grams of bottoms product. The distillate was a mixture of 
heptane and unreacted organic matter, amounting to 29.31 grams. The wiped 
film evaporator distillation of the bottoms product was carried out 
2-additional times at 140.degree. -141.degree. C. and vacuum of about 
0.25-0.31 mm. Hg., producing 68.72 grams of product having an anionic 
content of about 19%w (54 meq/100g).