CA1135147A - Detergent composition - Google Patents

Abstract

ABSTRACT

A detergent composition for personal use such as skin cleansing or care of the hair, comprising at least two surfacants, one being of a particular nonionic type and another being of a different type such as an amphoteric/anionic surfactant. The nonionic surfactant has a thickening effect and is typified by diabasic and tribasic acid reaction products of alkoxylated polyol fatty esters.

Description

1135147 J~J 985 .
DETERGENT COlrlPOSI~ION
The present invention relates to liquid detergent compositions ~or personal use, that is to say capable of use in contact with the skin of the person, usually for cleansing the skin or hair, such as a shampoo formulation or 8 bath additive. The invention iinds application in such compositions generally, but i9 especially useiul in those detergent compositions which have relatively low ocular irritation and yet have large ioam volume and improved ioam stability.
Detergent compositions, like most types oi liquid cleaning agents, generally comprise a m~xture of one or ~ more surfactants as the active ingredient, perfumes, - colouring agents, thickeners, etc. The suriactants have two portions: (1) hydrophobic hydrocarbon chain miscible with organic materials and (2) a hydrophilic end-group miscibIé with water. ~Jhen such a 6urfactant contacts a particle of soil, the hydrocarbon chains mix therewith and the hydrophilic end-groups are presented to the aqueous solution. This proces~ of emulsification allows the soil, which otherwise would resist removal by the water, to be cleaned from the body thereby. The surfacta~t~ may be classiiied as anionic, cationic, nonionic, or amphoteric, - depeDding upon the character of the end-groups.
It ie desirable that detergent compositions have high ioam volume and ioam stability, particularly ii they are ueed a~ ehampoo~. ~he ~mount of ~oam or lather produced by a ~hampoo has a direct bearing on the perceived ofiiciency with which it clean~ the hair. The stæbility Or that ioam indicates how long it will keep the hair lathered. Generally epeaking, the larger the volume oi ioam produced and the more stable the foam, the more efricient the perceived cleaning action Or the shampoo.
i ~ further desirable property for a shampoo, e~pecially o~e designed for use by children,is that it have low ocular ! 35 irritation. Because a shampoo may accidentally contact the I ocular mucoea during use, especiallg use by children, one t :' , , ' -,:~. ' : .

,- - ' :' ' . ' '.:'' ' ' ' ,.' .. ''':' .'.'. , ', .,", :
, ~ ' '' ' " ' . ~ : ' ,' 135~7 which cau~es relatively little irritation is both desirable and useful.
Non-irritating detergent compositions have been known and ha~e been in use for some time. United States Patentæ 2,999,069 and 3,055,836 are representati~e of such prior art non-irritating detergent composition~. ~hese compositions generally comprise an amphoteric ~ur~actant combined with an anionic suriactant and a nonionic surfactænt in admi~ture with other ingredients. The 10 ampho~eric-anionic suriactant consi8ts e~sentially of:
O ~ H
~ CH2CH - OH
R - C - N - Ro- N ~ 2 ~ CH2C~q R1 - (OC~2CH2)n 0 - S03 where R i~ a 9-17 carbon alkyl radic~1, Ro is an alkylene group of 2-4 carbon atoms, R1 is a member of the group ; con~i~ting of alkali metal~, triethanolamine, mixtures of 15 an a1k~1i metal with hydrogen and mi~tures of triethanol-amine with hydrogen. The nonionic surfactant portion of s the composition is usually a derivative of a 9-18 carbon atom iatty acid monoester of an aliphatic polyhydric alcohol reacted with 10-20 moles oi ethylene o~ide. ~he 20 method Or ~orming these compounds is taught in U.S.
~atent 2,781,384.
i In the reaction products of the formation of the amphoteric ~urfactant there may also be present some amount j oi the compound oi the iormula:
5, O H
¦ CH2CH20H
R-!C - N - Ro -- ~
which when reacted with the anionic surfactant forms:
0 Hl CH CH OH
R C N - Ro- N 2 2 . , I
~ R~( C~2CH2)n S03 .. :, . . .
- , . :. ' ~ :
.: . ~ ; .. .. , ,- . , ..
. - .

Detergent compositions relatively non-irritating to the eye while providing high foam volume and improved foam stability have also been proposed comprising certain surfactant betaines, an anionic surfactant and a suitable non-ionic surfactant.
These prior art compositions, although they are non-irritating and have good foaming characteristics, have generally low viscosities. Increasing the viscosity of the compositions by employing viscosity building additives or thickeners results in a deterioration of the foaming characteristics of the compositions. Increased viscosity without foam degeneration is desirable in order to formulate detergent compositions, especially non-irritating champoo compositions.
It has accordingly been the practice hitherto to include in shampoo formulations an ingredient acting as a thickening agent. In the case of the non-irritant compositions already referred to, such thickening agents are typified by polyethylene glycol distearate, for instance polyethylene glycol distearate 6000. The range of substances which can be used for this purpose is non-irritant compositions is somewhat restricted and it is by no means easy to thicken such compositions. Moreover the compatibility of additives to shampoo or other compositions for personal use is hard to predict, especially with regard to irritant properties.
A major drawback involved in the use of thickening agents such as polyethylene glycol distearate, especially if it is desired to adopt a continuous production process for a detergent composition, is that such thickeners are solids.
In order to incorporate them into liquid compositions it is necessary to bring them into liquid form, as by melting the thickener and mixing it into the heated composition.
It is an object of the invention to provide a detergent composition formulated from liquid ingredients and fulfilling a desired viscosity requirement.
It is a preferred object of the invention to provide such a composition which is suitable as a non-irritant type ~ 35 ~7 ; -4-of shampoo.
The invention is based on the concept of incorporating in a surfactant ingredient of the composition a chemical _tructure imparting thickening properties to the substance, 5 for example by introducing groupings characteristic of thickening agents, while maintaining the de~ired surfactant - properties, to provide a liquid ingredient which iæ thuæ
- bifunctional and compatible with the rest of the composition.
: We have previ~usly proposed to increase the vi~cosity oi detergent compositions of this type to a con~i tency ~quitable ~or marketing as a concentrate in tubee, by employing as non-ionic Qurfactantæ the reaction products o~ certain fatty ! acid monoesters with a relati~ely high molar ratio o~ an alkylene oxide, yielding formulations o~ viscosity greater than 4000 centipoise at 22-25C. In the present in~ention . the concept i8 extended, to provide alternative and liquid ,~ thickening aBent8 in ~ormulations o~:normal pourable liquid type~ by modifying the chemical structure o~ a non-ionic suriactant in 8uch a way that it pre8ent8 the a3pect of a known thickening agent in having an alkoxylated chain or chains each end oi which terminate8 in certain ~atty acid ester groups. Thi8 modification i~ brought about by ! employing a polybaæio acid as a bridge between the chains of alko~ylated non-ionic 8ur~actant compouna~ oi a type 325 previously uæed in detergent COmpOQition~ ior personal use.
5~ccording to the present invention we provide a . detergent compo~ition ior personal uæe comprising at least two suriactants, at least one Or said qurfactants being of jthe.non-ionic type de~ined below and at leaæt one of qaid ~0 surractants being of another type. The surfactant of ¦deiined type acts as thickening aeent and is ~sharacterised by the iollo~inz general ~orm~la:

.~___ , _ ..... . . .

. . , .. ,.;, ., ~ ~ ~, ``~ 1135~'7 ~ ' , o~

,1.. ~ /'' I
' ~o O
J ~
h P~ O
ô~/

' L.~.~ C~o . , . -I ~ 1~ 1 ~`; 1i.35~'7 Where R is a di- or trivalent hydrocarbon group;
R' ls di- or higher-valent hydrocarbon group or heterocyclic group;
` R~ is a monovalent hydrocarbon group containing at lea~t eight carbon atoms;
r and 8=0 or an integer;
~, m, p and q are integers, being at least 1;
provided that:
n ~ pm ~ rs = 4 to 100 inclusive r + p = 2 to 7 inclusive ~ q = 1 or 2 ; and iurther provided that up to 20 mole per cent oi the ethylene oxide groups mag be replaced by propylene oxide groups.
~ ~Ereferably R i8 the hydrocarbon residue o~ a dibasic or tribasic acid. Esamples of such acids are poly-ethylene diacids such as malonic, suocinic, adipic,pimelio, suberic and azelaic acidæ, polybasic acidæ or h~drogy acids 8uch as malic, tartaric or citric acids, aromatic ac$ds such as phthalic or trlmellitic acids, and ~; unsaturated diacids such as maleic or fumaric acid.
Preierably R' 18 the hydrocarbon residue or hetero-cyclic ring-conta1ning reRidue oi a polyol.
E~ample3 o~ ~uch polyols are ~orbitol, 80rbitan, i80sorbide and misture8 thereoi, other pentitol or he~itols or their anhydro-derivative~, pentaerythritol, glycerol or glycols, euch as ethylene glycol or propylene glycol.
Preierably R" ie a Cg 22 saturated or unsaturated hydrocarbon group, such as may be derived irom ~ono carboxylic acids having a Cg 22 hgdrocarbon group attached to the acid group. Examples oi these are acids derived irom natural sources, including lauric, p~mitic, oleic, etearic, and mgristic acids.
- Examples oi the non-ionic sur~actants thus defined are diba~ic acid reaction products ~f alkosylated sorbitan iatty e~ters, ior instance, the product having approsim~tely two ethosylated sorbitan monolaurate groups per succin~c acid group.

- ~ :. . ; - , .

1~3~4~7 ~ he non-ionic sur~actants to be employed in the inven-tion may be made from their component~ by processe~ of etherification and esteriiication.
Many o~ the #urfactants thus defined possess an unus~al property when mixed with water. It is known that certain ethoxglated materi~ls which are miscible with water show an increase in viscosity as the amount of water in the mixture increases. Typically this increase may be of the order of ten times the viscosity oi the undiluted ~urfactant. When a certain critical viscosity is reached, the ~iæcosity ralls again at higher ~ater concentrations.
With the suriactants deiined above the critical viscosity may be a hundred or moretimes higher than the undiluted surractant. This viæcosity increase effect i8 advantageous ~5 in the preparation of detergent compositions ior personal use s~Gh as shampoos. The viscosity increasing effect is noted in the presence o~ ionic and nonionic surfactants.
These nonionic suriactants may be u~ed with another type of suriactant of the most widely varied kinds suitable ior person 1 uæe. ~he proportion oi the deiinea nonionic suriactant uæed in compoæitions Or the invention Lay vary widely but will generally be in the range from to 20 per cent by weight oi the composition, more us~ y rrom 5 to 15 . Preierred compositions according to the invention may be baæed, as to the eurractant oi another t~pe, for instance on the combinations oi amphoteric suriactants or betaine surfactant~ with anionic surfactants already mentioned in connection with ~on-irritant iormulationæ.
~0 Partlcularly preierred iormulation~ comprise an amphoteric surractant combined with an anionic surfactant and a nonionic surractant Or the type herein defined in admixture with other ingredients. ~he amphoteric/anionic ¢omponent is described above.
It is envisaged that any anionic surfactant may be used in the detergent composition of the invention such as, ior example, an ~l~yl suliate of iormula R-CH2-OS03~, an alkylether suliate oi iormula R(OCH20H2)p-OS03~, an alkyl-113S1~7 monoglyceryl et~er sulfonate of iormula R-ocH2clE-aH
OH
an alkyl monoglyceride sulfate of formula RCOOC~ CH-C~ OS03~, OH
an alkyl monoglyceride sulfonate of iormula RCOOCH2C~H-CH2~0~X, an alkyl sul~onate of formula RSO ~, an OH
alkylaryl sulfonate oi ~ormula R

O o an alkyl sulfosuccinate of formula R-CH2-0-C- ~ - CH2-C-~, an alkyl saroosinate o~ formula R-C-N -CH2-COOS, an-acyl isethionate of formula R-C-O-CH2CH2S03X, an alkyl ~ ~H3 methyl tauride of formula R-C-N -C~2-C~2S03X, a ~atty acid proteln condensate of formula R~-(N~-CH-~ o~)r-aoo~, an alcohol ether carboxylate oi iormula R(CH2CH20)q~COO~

and the like; wherein R is higher ~lkyl having from 8 to 18 ¢arbon atoms; R' and R" are each hydrogen, lower alkyl, hydro~g-lower alkyl, thio-lower ~lkyl, carbo2y-lower alkyl, amino-lower alkyl, benzyl, or p-hydro2ybenzyl; X i8 an alk~li metal ion, alkaline earth metal ion, ammonium ion, or ammonium ion substitutea by ~rom o~e to three lower alkyls;
p iB an integer from 2 to 6; q is an integer from 2 to 6 and r i~ an integer irom 2 to 10.
The preferred type oi anionic surfactant is a~ alkyl ether sul~ate, more pre~erably sodium tridecylalcohol ether sul~ate in which q 18 about ~.0, known as tridecyl alcohol ether (~.0) sul~ate.
.

- . . . .
.

:``` ~'135~7 g The relative amounts of the amphoteric-anioni¢ surfac-tant that may be used in the pre~erred final formulation iB
from about 3 to about 20 per cent by wei~ht, for a 34 per cent active product and based on the total weight of the composition, the preferred amounts being ~rom 5 to 10 per cent. The nonionic surfactant may be present in an amount of from 1 to 20 per cent by weight of bhe total weight o~
the composition, the pre~erred amounts being from 5 to 15 per cent. The other ingredients in the formulation may include other surfactants, water, stabilizers, additional thickeners, dyes and an acid such as hydrochloric acid to neutralize the ~ormulation. Other ingredients commonly used in the de~ergent formulatione may also be present.

~5 In evaluating the compositions, the irritation test to be employed is the ~ollowing modified Draize test (see J.H.Draize, et al., Toilet Goods Associations No. 17, May, 1952, No. 1 Proc. Sci. Sect.):

~ 0.1 mi. o~ the undiluted sample of the neutral composition under test i~ dropped into one eye o~ each Or si~ rabbits. Daily administration of the same quantity o~
each Or the ~amples is continued for 3 consecutive days.
~ Ob~ervations are recorded after one hour, one day,; two days, three day~, four day~ and seven days after samples are dropped into the eyes. ~he extremes of the re~ults will either show substantially no change or only a slight irritation (ioreign body eifect) in the appearance Or the rabbit8' eye~ aiter 8even days, or severe irritation or complete corneal opacity, as the ca~e may be.

The foam le~el8 are measured by the rollowiDg met~od:

The following ingredie~ts are melted together to produce a ~5 eynthetic sebum:--- . , -: ':: ' ~ :

'`-"" 113S14'7 -lo-Per cent w/w ~auric ~cid 1.0 Myri~tic acid 2.0 Palmitic acid 7.0 Stearic acid 5.0 Oleic acid 15.0 Coconut oi.l 15.0 Olive oil 20.0 ~Squalene 5.0 1~0 ~Super Hartolan 5.0 ~ , ight~liquid para~fin 10.0 Spermaceti ` 15.0 ~ ~ 1 00 . O
15~ O.S~gramæ syntheti¢~eebum~and~200~ml tap water are added~to 12 g. of~the~material under be~t, and~the mixture i8 placed in~a lOOO ml stoppered graduated ' ~ cylinder and i~verted once per second ior one mlnut~e. The ~in 1 foam volume~and,lts decay~ oYer '~ 20 ~ ;one minute, are noted. ~ '-.
-~ The pre$erred detergent compo8ition8 of the invention may~be prepared;by firot~mixing the~a~photer.~c sur~actant ~'~ and the~anionic surfactant at ambient témperature until a 25- homogeneous mi~ture~is formed, and then adding the nonionic ~urfactant~and mixing the~whole at elevated temperatureæ
, ~ (about 50C) ror~about ten minute~ until a homogeneous mlsture i8 iormed. The~pH i8~then ad~usted to 7.2 + 0.3 by a,ddition oi a 8trong aoid (e!g. hydrochloric acid) or a ~'~ 30 étrong base (e.g. aqueou8 80dium hydroside 801utio~) a~
~;~ nee'ded.
: ':
~he preferre~ detergent compositionæ oi the invention may be w ed to clean hair and produce high foam volume and good foam stability while also having low ocular irritation and satisractory ~i8coæity. The detergent compo~ition~ of ~, ; , , . ,, ,: , ~, i: , : -. . .--,: ,. . .
., , - , , , ~ :

.. .. . .. ..

` ~13Sl~'7 the invention may also be used a~ uid soaps or cleansers for cleaning other parts of the human body, animals, inanimate objects and the like.
, The preferred detergent composition of the invention may be combined with water or other suitable solvents to yield the high lathering shampoo~ of the invention, which have good foam stability and low ocular irritation.

The remainder of the composition when used a~ a shampoo ~ normally essen~ially water, but the shampoo may al~o contain other thickeners, dye~, perfumes, preservative~, pH adjusters, and the like, a~ desired.

The invention i8 illustrated by the following Example~, the nonionic surfactant referred to being the reaction product of succinic acid and ethoxylated sorbitan mono-laurate in which there is an average of 20 mols of ethylene o~ide per mol of sorbitan and about two ethoxylated sorbitan monolaurate group~ per succ~n~c group.

A detergent iormulation was prepared from an aqueous ~olution of an amphoteric anionic surfactant complex and other detergent~. The amphoteric portion of the surfactant was:
~ H / H2 CH2 OH
3 C11 H23 ~ C - ~ - CH2 - CH2 - N
CH2 C 00 Na and was reacted with sodium tridecyloxydiethyleneoxyethyl ~ulphate as set forth in U.S. Patent No. 2,781,384.

: ' "

"

.
, 3S ~47 ~ he amount~ o~ the amphoteric-anionic surfactant, shown as a ~4 per cent active aqueous solution, and the nonionic surfactant as 100 per cent, are shown in Formula 1 below.
The anionic detergent is a 70 per ce~t active aqueou~
~olution of the same material used in the above comple~.

The betaine is a 30 per cent active aqueous solution o~
lauric/myristic dimethyl betaine. ~he pE of the composition wa9 ad~usted to 7.0 ~ 0.1 by the addition of hydrochloric acid. Sufficient deionised wate~ was added 80 tha~ the total sample weighted 100 grams. ~he viscosity of the 8ample, determined at 25~ by the Brookfield methoa was 520 cP. The sample wa8 tested for foaming and found to gi~e an initial foam volume of 500 ml decaying to 220 ml at ~5 one minute.

Formula 1 Per cent ~/w ~mphoteric/anionic 13.7 ~nionic 2.5 Betaine 2.0 Nonioni¢ ~uriactant 12.0 Preservati~e system 0.6 Dye and periume 0.2 Deionised water to100.0 per cent EXAMæLE 2 ~ detergent formulation was prepared using the same amphoteric-a~onic surfactant and nonionic detergent as in E%ample 1, the a~ount~ being as shown in ~ormula 2 below.
The pH ~ra8 adju8ted in the same way and water added so that the ~ample weighed 100 grams. The viscosity of the sample, deter~ined by the Brookfield method, was 680 cP. The . . - .,: -:, ~, .
. ~., , ~ . ; . .
- . .. . , -. . ~ ~ . : : . :

3 ~7 ~ample was tested ~or.foaming and found to give an initial foam volume of 550 ml, decaying to 230 at one minute.

. Formula 2 Per cent w/w Amphoteric/anionic 30.1 Nonio~ic surfactant 11.0 Preservative system 0.6 Dye and perfume 0.3 Sorbitan monolaurate 0.9 Deionised water to 100.0 per cent _ . _ . . . . . . . . ..................... .

,

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A detergent composition for personal use comprising at least two surfactants, wherein at least one of said surfactants is of the non-ionic type of the following general formula:

where R is a di- or trivalent hydrocarbon group, R1 is a di- or higher-valent hydrocarbon group or heterocyclic group, R" is a monovalent hydrocarbon group containing at least eight carbon atoms, r and s = O or an integer, n, m, p and q are integers, pro-vided that n + pm + rs = 4 to 100 inclusive, r + p =
2 to 7 inclusive, q = 1 or 2, and further provided that up to 20 mole per cent of the ethylene oxide groups may be replaced by propylene oxide groups, and wherein at least one of said surfactants is of another type which includes a non-irritant amphoteric/anionic or betaine/
anionic surfactant compound.

2. A detergent composition according to Claim 1 wherein R is the hydrocarbon residue of a dibasic or tribasic acid, R1 is the hydrocarbon residue or heterocyclic ring-containing resi-due of a polyol and R" is a C9-22 saturated or unsaturated hydro-carbon group derived from a mono-carboxylic acid having a C9-22 hydrocarbon group attached to the acid group.

3. A detergent composition according to Claim 2 wherein said nonionic surfactant is a dibasic acid reaction product of an alkoxylated sorbitan fatty ester.

4. A detergent composition according to Claim 3 wherein said dibasic acid is succinic acid and said alkoxylated ester is ethoxylated sorbitan monolaurate having an average of 20 mols of ethylene oxide per mol of sorbitan.

5. A detergent composition according to Claim 1 contain-ing from 1 to 20 per cent of said nonionic surfactant by weight of the composition.

6. A detergent composition according to Claim 3 or 4 containing from 5 to 15 per cent of said nonionic surfactant by weight of the composition.