GB1563089A

GB1563089A - Surface active agents

Info

Publication number: GB1563089A
Application number: GB28242/75A
Authority: GB
Original assignee: Albright and Wilson Ltd
Current assignee: Solvay Solutions UK Ltd
Priority date: 1975-07-04
Filing date: 1975-07-04
Publication date: 1980-03-19
Also published as: ZA763959B; IT1063137B; AU506059B2; NO762270L; FR2316222B3; DE2629849A1; NL7607321A; SE7607568L; AU1556676A; DK299576A; FR2316222A1; BE843719A

Description

(54) SURFACE ACTIVE AGENTS (71) We, ALBRIGHT & WILSON LIMITED, a British Company of P.O. Box 3, Oldbury, Warley, West Midlands, England do hereby declare the invention, for which we pray that a Patent may be granted to us and performed to be particularly described in and by the following statement: The present invention provides improved surface active agents which are useful in shampoo formulations.

It has been proposed to incorporate into shampoo formulations certain amphoteric, nitrogen containing ether sulphates, such as fatty acid amide ether sulphates of the formula RCONH(C2H4O)nSO3X, and amine ether sulphonates of the formula RNH(C2H40)nS03X, where R is alkyl, n is from 2 to 20 and X is alkali metal or ammonium. The alkyl amine ether sulphates have been prepared by the reaction of an amine RHN2 with ethylene oxide followed by sulphation of the resulting amine ether. The foregoing preparation forms, predominantly, an amine ether sulphate of the above formula when R is, for example, a tertiary alkyl group. However, when R is a primary alkyl group, we believe that the second hydrogen of the amine RNH2 is more labile so that the product may contain a substantial proportion of at least one of the amine bis (polyalkyleneoxy) sulphates

In practice it is found that primary alkyl amine ether sulphates prepared by the foregoing methods tend to possess a degree of skin irritancy. We believe that the irritancy is, at least in part, due to the small proportion of primary alkylamine RNH2 and/or the alkylamine mono (polylakyleneoxy) sulphate RNH(C2H2O)nSO3X in the product. We believe that the free amine hydrogen of these compounds is liable to cause skin irritation.

We have now discovered a novel product which, although almost identical with the amine ether sulphates having regard to their desirable surface active properties is surprisingly mild to the skin in comparison with the known products.

Our invention provides N-alkylated dialkanolamine sulphates and N-alkylated dialkanolamine ether sulphates, substantially free from primary and secondary amines.

"Substantially free from primary and secondary amines" means that the product does not contain sufficient of these materials to cause significant irritation on normal skin. "Alkylation" as used herein means the reaction of a secondary amine with a compound of the formula RX (where R is an alkyl group, or an interrupted alkyl group containing one or more ether linkages and/or a benzene ring or an aralkyl group and Xis the residue of a strong acid HX) to form a tertiary amine containing the group R.

"Alkylated" describes a secondary amine which has been subjected to such alkylation, and derivatives thereof.

The novel alkylated dialkanolamine sulphates of our invention are prepared by alkylating a dialkanolamine, preferably diethanolamine, for example by reaction with an alkyl halide, e.g.

an alkyl chloride, or preferably an alkylsulphate or alkyl sulphuric acid followed by sulpha tion of the hydroxy alkyl side cham. Preterably, however, the alkylated dialkanolamine (preferably alkylated diethanolamine) is alkoxylated, e.g. by reaction with ethyleneoxide before the sulphation to provide the alkylated dialkanolamine ether sulphates. Alternatively, the latter products are obtained by alkylating a bis (polyoxyalkyl) amine, and sulphating the resulting alkylated dialkanolamine ether.

Preferably the alkyl group is an N-alkyl group having from 8 to 23, preferably 10 to 16 carbon atoms. Alkylating agents with branched chain, including tertiary, alkyl groups, alkaralkyl and aralkyl groups may also be used. Alkyl groups interrupted by one or more ether linkage are also operative, e.g. groups of the formula R(OR')n where R is an alkyl group having from 8 to 23 and preferably 10 to 16 carbon atoms, R' is an alkylene group (preferably ethylene) and n is a number from 1 to 10, e.g. 1 to 5. Alkylation of the dialkanolamine or dialkanolamine ether may be performed by any of the methods well known in the art for alkylating amines, for example by reaction of the dialkanolamine, e.g. diethanolamine, with the corresponding halide, e.g. an alkyl chloride or bromide. However, preferably, an alkyl sulphuric acid of the type formed when a fatty alcohol or ethoxylated fatty alcohol is reacted with a sulphating agent such a chlorosulphonic acid is neutralised with an excess of the dialkanolamine ether. Other sulphating agents such as sulphamic acid or preferably sulphur trioxide may be used to form the alkyl sulphuric acid. Typically the mixture is heated in an inert atmosphere (e.g. under nitrogen) for a sufficient time substantially to complete the reaction. Typically the mixture is heated at a temperature above 100"C and up to 300"C, e.g.

200 - 250"C, preferably about 220"C for from 2 to 10 hours e.g. 5 hours. Preferably a stoichiometric excess (e.g. from 3 to 10 molar excess) of the alkanolamine is employed whereupon the mixture separates into two phases and the excess phase is separated for recovery of alkanolamine. The product must be purified e.g. by washing with hot water to remove any residual dialkanolamine or dialkanolamine ether. The alkylated dialkanolamine or alkylated dialkanolamine ether is preferably dried e.g. by heating under vacuum.

Alkoxylation of the alkylated dialkanolamine (or alkylated dialkanolamine ether) may be carried out by any of the methods for alkoxylating alcohols, which are well known in the art.

Preferably the alkylated dialkanolamine is reacted with propylene oxide or more preferably ethylene oxide. The alkoxylated product may typically contain an average of up to 20 total ethylene oxy units per molecule, e.g. 1 to 6 preferably 2 to 4.

According to a typical procedure the alkylated dialkanolamine is charged to a reactor and contacted with an excess of the alkylene oxide in the presence of a basic catalyst (e.g. an alkali metal hydroxide or alkoxide such as sodium methoxide). Preferably the alkylene oxide is added at a sufficiently slow rate to maintain a maximum reaction pressure of 50 p.s.i. at throughout the reaction. The mixture may be heated e.g. to temepratures of 100 - 200"C preferably about 1200C for up to 5 hours, and any excess alkylene oxide may then be stripped off e.g. by heating under vacuum.

Sulphation of the alkylated dialkanolamine or its ether may readily be effected by any of the means for sulphating alcohols which are well known in the art, e.g. by means of chlorosulphonic acid, concentrated sulphuric acid, sulphamic acid, or preferably sulphur trioxide.

The products are preferably prepared as their sodium, potassium lithium, ammonium or amine salts by methods well known in the art, e.g. the ammonium salt may be prepared by using sulphamic acid in the sulphation step, and may be converted into the corresponding alkali metal salts by boiling with the appropriate alkali metal hydroxides. Alternatively, the sulpho-acid prepared by sulphating the alkylated dialkanolamine or alkylated dialkanolamine ether may be neutralised with an aqueous base such as aqueous sodium hydroxide, potassium hydroxide or ammonium hydroxide or a corresponding carbonate.

The invention therefore, according to a further aspect provides a method for the preparation of our novel surface active agents, which comprises the steps of (i) alkylating (as herein defined) a dialkanolamine or bis (polyoxyalkyl) amine of the formula:

wherein each R' is an alkylene group having from 2 to 4, preferably 2 carbon atoms, and n and m are each whole numbers from 1 to 20 which may be the same or different, to introduce a group of the formula R(OR')q wherein R is an alkyl or alkaralkyl or aralkyl group having 8 to 23 carbon atoms, R' has the same significance as above and q is from 0 to 20 preferably 0 to 5, (ii) separating any unreacted dialkanolamine or dialkanolamine ether from the alkylated dialkanolamine or alkylated dialkanolamine ether, (iii) optionally reacting the product with sufficient alkylene oxide. preferably ethlylene oxide to provide a total or up to 20 oxyalkylene units per mole and (iv) sulphating the product to provide a compound or mixture of compounds of the formula (or average formula):

where R, R', q, n and m have the same significance as before, p is from 0 to 1 and X is sodium, potassium, lithium, ammonium or a substituted ammonium ion.

A further embodiment of our invention provides a hair shampoo formulation comprising the novel products of our invention. Such shampoo formulations may typically contain other surface active ingredients commonly used in shampoos. The other ingredient which may be present in the shampoo formulation include detergents, especially the milder anionic or amphoteric detergents, or cationic detergents. For example, alkyl ether sulphates, such as sodium lauryl ethoxy or polyethoxy sulphate are preferred on grounds of mildness to alkyl sulphates, such as sodium stearyl sulphate, although the latter may be present. Alkyl benzene sulphonates such as sodium dodecyl benzene sulphonate, alkyl sulphonates and olefine sulphonates are all normally considered too harsh but may optionally present, preferably in small amounts. Alkyl betains, such as laury, myristyl, cocoyl, cetyl or oleyl dimethyl betaines are very suitable for use in the present formulations, as are alkyl amide betaines, alkyl amine oxides, (e.g. coconut dimethyl amine oxides) alkyl ether amine oxides and amide ether sulphates.

Our shampoo formulations according to our invention preferably contain cationic detergents, especially where there is little or no anionic detergent present. For example, we may use alkyl trimethyl ammonium halides, where the alkyl group has from 8 to 22 carbon atoms, such as cetyl trimethyl ammonium chloride, alkyl pyridinium halides, alkyl trimethyl ammonium methosulphate or alkyl dimethyl benzyl ammonium halides. The novel surfactants of our invention are especially compatible with high molecular weight cationic resins such as quaternised polyvinyl pyrrolidone.

Our shampoo formulations may also contain non-ionic detergents, although these are generally less preferred and are only present normally as minor components of the formulation if at all. For example, we may include fatty diethanolamides such as coconut diethanolamide, or fatty monoethanolamides such as stearic monoethanolamide or fatty isopropanolamides. Other non-ionic detergents include alkyl ethoxylates and poly ethoxylates, fatty acid ethoxylates and ethoxylated monoesters of ethylene glycol, glycerol or sorbitul.

The formulations may also include opacifiers such as ethylene glycol monostearate, inorganic salts such as sodium chloride, perfumes, solvents such as ethylene glycol, or isopropanol, colouring matter, lanolin and its derivatives, formalin and other preservatives, antiseptics, foam stabilisers, conditioning agents and oils.

The pH of the formulation is preferably from 4 to 7, most preferably 4.5 to 6 which may be achieved by addition of weak acids such as acetic, citric or tartaric acid.

The shampoo is usually in the form of an aqueous solution containing from 5 to 50% by weight of surfactants preferably 10 to 35% by weight. The novel surfactants of our invention typically constitute from 20 to 80%, e.g. 50% by weight of the active ingredients.

The invention will be illustrated by the following examples: Example I 300 gms of chlorosulphonic acid was added with stirring over 30 minutes to 496 gms of a mixture comprising 70% dodecyl and 30% myristyl alcohol. The mixture was maintained under 15 to 20 inches mercury vaccum at 30"C for 30 minutes to strip off hydrogen chloride and 700 gms of sulpho-acid was recovered.

The sulpho-acid was neutralised by adding slowly to 2192 gms of anhydrous diethanolamine slowly at 30"C. The mixture was stirred under an atmosphere of nitrogen for 5 hours at 220"C and the product was then allowed to cool and separate into layers. The lower layer was discarded.

The upper layer was recovered and washed with three portions of 500 cc each hot water. A small amount of ethanol was added to break the emulsion which formed at this stage. The washed alkylated dialkanolamine was dried under vacuum at 90"C for 4 hours giving 653 gms of the intermediate product against a theoretical yield of 720 gms e.g. 91% recovery. The intermediate product had a base value of 199 mgs. KOH per gm.

The intermediate product was mixed with 4 molar portions of ethylene oxide and a catalytic amount of potassium hydroxide in a sealed reaction vessel maintained at 1100C. The temperature was allowed to rise to 1400C while the pressure was maintained at 50 lbs per square inch. The base value of the ethoxylated amine ether was 126 mg. KOH/gm compared with a theoretical value of 122. The composition contained 4% polyethylene glycol.

128 gms of chlorosulphonic acid was added slowly to 445 gms of the ethoxylated amine ether with stirring under 15 to 25 inches of mercury vacuum at 300C over a period of 75 minutes. The mixture was held for a further 30 minutes at 300C under vacuum and the product finally added slowly to a stirred solution of 95 gms 48 aqueous sodium hydroxide, in 1,000 gms water maintained below 30"C. 1,608 gms of neutralised product was recovered containing 22.7% active matter, 6.7% free unsulphated ether, 1.6% sodium sulphate, 3.4% sodium chloride and 66% water.

Example 2 75 gms of diethanolamine were charged to a sealed reactor 176 gms of ethylene oxide were added in the presence of sodium methoxide catalyst, in a proportion of 0.25 % based on the diethanolamine. The temperature of the mixture rose to 140"C under a pressure of 50 Ibs per square inch until the reaction was complete.

An 8 mole excess of the alkoxylated diethanolamine was left in the reactor and the mixed dodecyl myristyl sulpho-acid prepared as according to Example 1 was added slowly at 300C.

The mixture was heated at 2200C under nitrogen with stirring for 5 hours and then separated and washed with hot water as described in Example 1. The product was then dried, sulphated and neutralised as described in Example 1.

WHAT WE CLAIM IS: 1. A sulphate of an alkylated dialkanolamine or alkylated dialkanolamine ether, as herein defined, substantially free from primary and secondary amines.

2. A sulphate according to claim 1 having the molecular formula:

wherein R is an alkyl, alkaralkyl or aralkyl group having 8 to 23 carbon atoms or a group R(OR') n-, R' is an alkylene group, each n is from I to 20 and Xis alkali metal or ammonium.

3. A sulphate according to claim 2 wherein R is an n-alkyl group.

4. A sulphate according to either of claims 2 and 3 wherein R' is an ethylene group.

5. A method for the manufacture of sulphates of alkylated dialkanolamines comprising: (i) alkylating, as herein defined, a dialkanolamine or dialkanolamine ether; (ii) separating any free dialkanolamine or dialkanolamine ether from the alkylate; (iii) optionally alkoxylating the alkylate; and (iv) sulphating the alkylate or alkoxylated alkylate.

6. A method according to claim 5 wherein the dialkanolamine is diethanolamine.

7. A method according to either of claims 5 and 6 wherein step (i) comprises neutralising an alkyl sulphuric acid with an excess of the dialkanolamine or dialkanolamine ether.

8. A method according to claim 7 wherein at least part of the excess dialkanolamine forms a separate phase which is separated from the phase containing the alkylate.

9. A method according to any of claims 5 to 8 wherein the step (ii) comprises washing the phase containing the alkylate with water at an elevated temperature, and drying the alkylate.

10. A method according to any of claims 5 to 9 wherein step (iii) comprises heating the alkylate with from 1 to 20 moles of ethylene oxide per mole of alkylate.

11. A method according to any of claims 5 to 10 wherein the alkylate or alkoxylated alkylate is sulphated with chlorosulphonic acid, concentrated sulphuric acid, sulphamic acid or sulphur trioxide.

12. A method according to any of claims 5 to 10 wherein the product of step (iv) is neutralised with the aqueous hydroxide or carbonate of sodium or potassium.

13. A method according to any of claims 5 to 12 substantially as described herein with reference to any of the examples.

14. A sulphate of an alkylated dialkanolamine or alkylated dialkanolamine ether pre pared by the method of any claims 5 to 13.

15. A hair shampoo composition containing a sulphate according to any of claims to 1 to 5 and 14.

YS Y Ts

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

with a theoretical value of 122. The composition contained 4% polyethylene glycol.

128 gms of chlorosulphonic acid was added slowly to 445 gms of the ethoxylated amine ether with stirring under 15 to 25 inches of mercury vacuum at 300C over a period of 75 minutes. The mixture was held for a further 30 minutes at 300C under vacuum and the product finally added slowly to a stirred solution of 95 gms 48 aqueous sodium hydroxide, in 1,000 gms water maintained below 30"C. 1,608 gms of neutralised product was recovered containing 22.7% active matter, 6.7% free unsulphated ether, 1.6% sodium sulphate, 3.4% sodium chloride and 66% water.

Example 2

75 gms of diethanolamine were charged to a sealed reactor 176 gms of ethylene oxide were added in the presence of sodium methoxide catalyst, in a proportion of 0.25 % based on the diethanolamine. The temperature of the mixture rose to 140"C under a pressure of 50 Ibs per square inch until the reaction was complete.

An 8 mole excess of the alkoxylated diethanolamine was left in the reactor and the mixed dodecyl myristyl sulpho-acid prepared as according to Example 1 was added slowly at 300C.

The mixture was heated at 2200C under nitrogen with stirring for 5 hours and then separated and washed with hot water as described in Example 1. The product was then dried, sulphated and neutralised as described in Example 1.

WHAT WE CLAIM IS: 1. A sulphate of an alkylated dialkanolamine or alkylated dialkanolamine ether, as herein defined, substantially free from primary and secondary amines.
2. A sulphate according to claim 1 having the molecular formula:

wherein R is an alkyl, alkaralkyl or aralkyl group having 8 to 23 carbon atoms or a group R(OR') n-, R' is an alkylene group, each n is from I to 20 and Xis alkali metal or ammonium.
3. A sulphate according to claim 2 wherein R is an n-alkyl group.
4. A sulphate according to either of claims 2 and 3 wherein R' is an ethylene group.
5. A method for the manufacture of sulphates of alkylated dialkanolamines comprising: (i) alkylating, as herein defined, a dialkanolamine or dialkanolamine ether; (ii) separating any free dialkanolamine or dialkanolamine ether from the alkylate; (iii) optionally alkoxylating the alkylate; and (iv) sulphating the alkylate or alkoxylated alkylate.
6. A method according to claim 5 wherein the dialkanolamine is diethanolamine.
7. A method according to either of claims 5 and 6 wherein step (i) comprises neutralising an alkyl sulphuric acid with an excess of the dialkanolamine or dialkanolamine ether.
8. A method according to claim 7 wherein at least part of the excess dialkanolamine forms a separate phase which is separated from the phase containing the alkylate.
9. A method according to any of claims 5 to 8 wherein the step (ii) comprises washing the phase containing the alkylate with water at an elevated temperature, and drying the alkylate.
10. A method according to any of claims 5 to 9 wherein step (iii) comprises heating the alkylate with from 1 to 20 moles of ethylene oxide per mole of alkylate.
11. A method according to any of claims 5 to 10 wherein the alkylate or alkoxylated alkylate is sulphated with chlorosulphonic acid, concentrated sulphuric acid, sulphamic acid or sulphur trioxide.
12. A method according to any of claims 5 to 10 wherein the product of step (iv) is neutralised with the aqueous hydroxide or carbonate of sodium or potassium.
13. A method according to any of claims 5 to 12 substantially as described herein with reference to any of the examples.
14. A sulphate of an alkylated dialkanolamine or alkylated dialkanolamine ether pre pared by the method of any claims 5 to 13.
15. A hair shampoo composition containing a sulphate according to any of claims to 1 to

5 and 14.

YS Y Ts