CA2110413C

CA2110413C - Self-thickened cleaning compositions

Info

Publication number: CA2110413C
Application number: CA002110413A
Authority: CA
Inventors: Stefano Scialla; Peter Rosalia Joannes Geboes; Michel Jean Carrie; Eddy Vos
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1991-06-14
Filing date: 1992-06-08
Publication date: 1997-12-09
Anticipated expiration: 2012-06-08
Also published as: GR3018145T3; JPH06508393A; DE69205730D1; EP0518401B1; EP0518401A1; DK0518401T3; NZ243138A; AU2336492A; CA2110413A1; AU667481B2; WO1992022628A1; ATE129742T1; ES2079138T3; MX9202883A; TR25965A; DE69205730T2; BR9206153A; IE921922A1

Abstract

Self-thickened aqueous cleaning compositions are described which comprise an alkyl sulfate anionic surfactant and an electrolyte system. The compositions are made physically stable, even at low temperature, by incorporating therein a nonionic surfactant from a selected class. The figure compares a composition of the present invention containing UKANIL R, an ethoxylated alcohol the same composition not containing UKANIL R. The present invention shows viscosity stability over a broad temperature range.

Description

~092f226~8 P~T/US92/04772 2 L1~4~3 SELF-THICXENED CLEANING COMPOSITIONS

- Technical field The present invention relates to cleaning compositions.
The compositions according to the present invention are self-thickened, in that they do not require the presenc a thickensr compound; ~urthermore, the compositions according to the present inv~ntion are physically stable, ~;
even at low temperatures. The compositions accordin~ to the present invention are USP-fUl for insta~ce as hard surface cleaning omposltions or as laundry cle~ni~g compositions.

Backqrvund Thickened cleaning composltions are well known in the art, and have found various applications for instance in ~:~ the context of hard surface or laundry cleaniny compositions.

: The simplest ~ay to make such compositions is to add a thickener on top~of a non-viscous product. However, W092/226~8 2 1 1 ~ ~ 1 3 PCT/US92/04772 thickeners can be seen as undesirable in many respects, such as processing issues, long term product stability issues as well as other considerations related to formula cost. It is thus desirable to formulate a cleaning composition which is viscous, but does not necessarily contain a thickener.

The art teaches that it is possible to do so by using a sy~tem where viscosity is built by combining an anionic sur~ac~ant together with an electrolyte in an aqueous medium, wherein the viscosity can be adjusted by balancing both ingredients. This system is very often used in the formulation of ~5~mpO0S, but has also found application in . ,, cleaning compositions. In theory, this solution can be use~
with any anionic surfactant, but the compositions of the present invention only use an alkyl sul~ake anionic surfactan~ derived ~rom natural coconut oil; indeed, this ~:
surfactant provides good performance and is particularly desirable for obvious environmental reasons.
, ~
Thus, self-thickened compositions can be made which comprise such an anionic surfactant derived from natural coconut oil and an ~lectrolyte. The ~iscosity of such a composition is of course sensitive to temperature, and a new technical problem has been identified in that such compositions are not physically stable at low temperature, where the product undergoes phase separation, As a result, -:
the product has an aesthetically unacceptable aspect.
.:
lt has now been found that this problem could be solved :~-.
;by using a specific electrolyte and adding to the system above a nonionic surfactant ~rom~a selected class.
;
Canadian patent CA 1 1~4 381 discloses scouring ~:
compositions containing anionic surfactants, an electrolyte and an ethoxylat~ed alcohol surfactant.

'~

~.

. 3 2~10~13 European patent EP 116 905 ~eaches the use of ~n ethoxylated and/or propoxylated alcohol surfactant to reduce the viscosity of industrial-grade synthetic anionic surfactant concentrates~
European patent application EP 329 209 discloses scouring compositions comprlsing a surfactant, an electrolyke and a solvent to build viscosity.

Summary o~ the invention The compositions according to the present invention are self-thickened a~ueous cleaning compositions havi~g a viscosity of from 50 to 700 cps at~ 60rpm shear r~te at 20~C, which comprise from 1% to 25~ by weigh~ o~ the total compositlon of an alkyl sulphate anionic surfactant derived from natural coconut oil, from 0.1~ to 8~6 ~y weight of the :~
total composition of ammonium salts and ~rom 0.5% to 25% by weight of the total composition of a compound o~ the structure:
:
Rl-~ _ ~(R2o~n~R30)m]--R4l wherein :
,.

- Rl is a Cl_2~ alkyl or alkenyl group;
- R2 is a C2_4 aliphatic hydrocarbon chain;
- ~3 is a methyl or ethyl~monosubstituked C2-C4 aliphatic hydrocarbon chain;
- R4 is a Cl_~5 alkyl or~alkenyl or carboxyl chain, or H;
- n is an integer:of from~ 1 to lO; ..
- m is an integer of ~rom 0 to 20;
.
or mixtures ther,eof~ :

Detailed description of the invention The compositions according to the pre.sent invention comprlse from 1%:~to ~5~ by weight o~ the total composition, :~

~: :

WO~/22628 ~ ~o ~l3 PCT/US~2/~4772 preferably ~rom 2% to 8% by weight of the ~otal composition, most preferably 3% to 5% o~ an alkyl sulphate anionic surfactant derived from natural coconut oil, or mixtures .
thereof. Suitable alkyl sulphate anionic surfactants for use herein can be made by the processes well known to the man skilled in the art. Typically, such surfactants are made from coconut alcohol which is sulfated and possibly ethoxyla~ed. Indeed, ethoxylated alkyl sul ~a~e sur~actants are also suitable for use herein, but the average degree of ethoxylation o~ the anionic sur~actants to be used herein should not be more than 2.

The neutrali2ing cation ~or the alkyl sul~ates d~rived from natural coconut oil to ~e used herein ca~ b~ any o~ the conventional cations used in detergent technology, such as ammonium, potassium or unsubstituted or N-substituted ammonium saltsl or mixtures thereof; preferred are the sodium salts.

The viscosity of the compositions according to the invention is obtain~d by using ammonium salts as an electrolyte; suitable ammonium salts for use in the compositions according to the inYention include alkanolammonium salts, ammonium chloride, ammonium ~cetate, ammonium citrate, ammoniu~ carbonate and the like; it is the electrolyte together with the above described surfactants which builds the viscosity. The viscasity of the composition depends on the proportion of both ingredients, the general rule being tha~ the more electrolyte is added, the more .
viscosity i5 o~tained. The compositions according to the present invention comprise from 0.1% to 8% by weight of the total comp~sition of ammonium salts, preferably from 0.2% to 6%, most preferably 0.3% to 5%. The ratio of ammonium salts :~
to anionic surfactant is adjusted so as to obtain a composition having a visc05ity of from 50 to 700 cps at 60rpm shear rate at 20~C, more preferably 80 cps to 350 cps. The viscosity of the compositions according to the invention allows to use said:compositions on vertical surfaces.

,, ' W092~2262~ PCT/US92/04772 21 i~
Such a product comprising the surfactant and the electrolyte describe~ herein above could be used as such, however, as ~escribed in the background part, physical stability of the product is not ~atisfactory under all conditions, in that the product undergoes phase separation at low temperatures, around 10~C and below~ It has now been found that this problem could be solved by simply adding to the composition a nonionic surfactant from a selected class.
Accordingly, the compositions according to the present invention comprise ~rom 0.5% to 25~ by weight o~ the total composition, prefer~bly from 0.6~ to 10~ , most preferably from 0.7% to 2~ ~f a compound of the formul~

.. . . .
. :

Rl-a _ ~(R2o)n(R3o)m]--R4~ wherein :

- R1 is a C1_2S alkyl or alkenyl chain, preferably C~ 5, preferably alkyl;
- R2 is a C2_4 aliphatic hydrocarbon chain, preferably C2;
- R3 is a methyl or ethyl monosubstituted C2-C4 aliphatic hydrocarbon chain, preferably a methyl substituted ethylene; : :
- R4 is a Cl 25 alkyl or alkenyl or carboxyl chain, or H, ' preferably H;
- n is an integer o~ from 1 to 10, preferably 1 to 5;
- m is an integer o~ from 0: to 20; preferably 0 to 10, most preferably 0 to 3, or mixtures thereof.
:
It is to be understood that, in the chemical formula i above, R20iand R30 groups~may~appear in any sequence in the : :~: molecule; also, when n and m are~greater than 1, dif~ere~t R20 and R30 groups may:appear:in a same molecule. These surfactant are commercially aYailable from ICI under the trade name UKANI~ ~M ~,:or ~rom:BAS~ under the trade name PLURAFAC LF ~. Preferred surfactant where m is 0 are ~: ' ; ~:

, ~
: ~ ' W092/2262~ 2 ~ t3 PCT/US92/04772 available from SHELL under the trade name DOBANOL ~ or ~rom BASF under the trade name LUTEN50L ~. ~

The compositions according to the invention are acidic ;
and have a pH of from 1 to 6, preferably 2.5 to 5. The pH of the compositions according to the invention is partially determined by the amount of e~ectrolyte, but the pH of the ~inal composition can be adjusted by the addition of appropriate acidifiers such as organic or inorganic acids, or acidic salts which buffer pH to an acid value. ~mples of suitable acidifiers are sulfuric acid, phosphoric acids, although somewhat undesirable from an environmental viewpoint, hydrochloric acid, phosphonic acid, citric acid, ~:
acetic acid, tartaric acid, maleic acid~ succinic acid, malonic acid and the like, or mixtures thereof.

In a particularly pxeferred embodiment of the invention, the compositions comprise from 0.5% to 20% by weight o~ the total composition of citric acid, preferably from 1% to 10~
Indeed, it has been found there are many benefits obtainable from the addition of citric acid to the compositions ~.
according to the prPsent invention,:such as limescale ~emoval .~.
performance and improved disinfesting properties. When citric acid is used in the compositions according to the invention, it is possible to form in~situ the ammonium salts described herein~above, in this case ammonium citrate by incorporating ammonium hydroxide~ The presence o~ citric acid also helps to build the product's viscosity; When high le~els of citric acid are used:~to obtain optimal performances, it~:may~be necessary;to adjusk the pH of the composition by adding an alkalinizing agent~

In a preferred embodime'nt,~the compositions according to the invention further comprise~from 0.01~ to 0.5~ by weight .:;
of~the total composition of:a~ capped 1j2:- prop~lene terephthalate polyoxyethylene~polyester of ~he formula: ~
-:
: ~ ' ,':,' ~ ~ ::SUB~ TE SHEE~T

..

W0~2/2~628 ' PCT/US~2/0477~
7 2 1 ~ 3 0 o CH3 o O
CH3(OCH~cH2)n(~c ~ c-CH2CH)uOc ~ Co-(cH2cH2o)n CH3 wherein n is an integer of ~rom about 12 to 43 and u is an integer of from about 2 to 8, and mixtures thereof. These polymers have been extensively described as soil release agents in softening compositions and in liquid detergent compositions and in EP 185 427 and ~P 220 156. However, it has now been found that, the above polymers have a regulating ef~ect on the viscosity of the composikions; indeed, the viscosity of a ~iven product is ~ypically very sensitive to temperature, and the compositions according ~o the present invention, although they remain phase-stable at all temperatures, tend to become more viscous when temperature drops. It has now been found tha~ the above polymers make tha compositionls viscosity Iess sensitive to temperature;
thus the compositions have less tendency to become thicker at low temperatures.

In a preferred embodiment, the compositions according to the present invention ~urther comprise from 1% to 15% by weight of the total composition, preferably from 2% to 10%, most preferably 3% to 8% of hydrogen peroxide. In the compositions of the prior art, i,e. viscous systems consisting of an anionic sur~acta~t and an elec~rolyte, the addition of hydrogen peroxide leads to a severe drop in viscosity; another advantage of the compositions according to the present invention, i.e. comprising the stabilizing nonionic surfactant from the selected class, is that the addition of hydrogen peroxide has little e~ect on the produck's viscosity Thus, bleaching compositions can also be made according to the present invention.

The compositlons according to the present invention may also comprise conventional ingredients such as solvents, chelating agents, fragrance and dyes, provided all these ingredierlts are compatible with the compositions.

SUBS~TU~E S~EET ~' '"~

2 l 1 ~ ~ 1 3 PCT/US92/0477~

The compositions according to th~ present invention can be made by any process where all ingredients are mixed together. However, in the preferred embodiment where the compositions comprise a substantial amount of citric acid, it :~
is preferred to use a process which comprises the st~ps of dissolving the citric acid in water separately ~rom the remainder o~ th~ composition, adjusting the pH o~ the citric acid solution to the target pH value o~ the final composition, and adding said pH-adjusted citric acid ~olution to the remainder o~ khe composition, the pH o~ which having ~:
been separa~ely adjusted ~o sai~ t~rget pH value. In c~se the compositions also comprise hydroge~ p~ro~ide, it is preferred to add the hydrogen peroxide as a final step in the process, on top of the remainder sf the composition including the citric acid.

The compositions according to the present invention can be useful in many di~ferent con~exts where it is desirable to use a viscous product~ For insta~ce, hard surface cleaning :~
compositions are advantageously formulated as Yiscous products in order to optimize their application to vertical surfaces, for instance baththubs or toilet bowls. Indeed, the product's viscosity prevents the product f rom running too quickly down said surface.

The compositions according to the present invention can also be used in the context of laundry cleaning. For instance, a lau~dry pretreatment composition can be advantageously ~ormulated as a viscous product for a most convenient application to the laundry ~abri~s. Indeed, the viscosity o~ the product allsws for a better control of the dlspensing of the product and prevents the spreading o~ the :
dispensed product beyond ~he fabric surface being pretreated.

The following examples will further illustrate the ;.
present invention.

SUBSTITU-ll E SI~EET

.

W092/2262~ PCr~US92/0~772 9 2110~1'3 Examples The following compositions are made, which contain the listed ingredients in the listed propor~ions (weight %).

Compositions~ 2 1 3 1 4 1 5 1 6 NaCnAS ¦ 3-5 ¦ 3-5 ¦ 3-5 ¦ 4~0 ¦ 2.4 ¦ 3.5 Citric Acid ¦ 5.8 ¦ 6.0 ¦ 5.8 ¦ - ¦ 4.0 ¦ 5.7 Ukanil R ¦ 1.5 ¦ 1.5 ¦ 1.0 ~ 1.0 ¦ 2.0 ¦
Dobanol R 23-3 1 _ I _ I _ I - I - I 0.~
A~unonia ~ 0.6 1 0.~ 1 0.7 ~ I 0.32 Ammonium Chloride ~ I 1.0 Sodium Chloride I _ I _ I - 1 4.0 ¦
Tri Ethanol Amine I - ¦ - ¦ 1-5 ¦ - ¦ ~ ¦ ~ ~
Hydrogen Chloride I _ I _ I _ ¦ 9.051 Hydrogen Peroxide I _ 1 6~0 ¦ ~ I _ I _ I _ S~dium Cumene Sulphonate ¦ 1.0 ¦ - ¦ - I _ l - l - ;
Perfume 1 0.5 1 - I 0.5 1 - I - I 0.4 pH ¦ 4.1 ¦ 4~ ¦ 4.5 ¦ 2,5 ¦ 2.2 ¦ 3.6 ~.
Water & minors I ~lp to 100%

Data :
The following data illustrates the benefits obtained from the compositions ac~ording to the present invention. ~ :
composition is made which comprises, by weight o~ the total composition: .
, .
: Sodium coconut alkyl sulfate:3.5% ;
: Ammonia: O.7S~
:
Citric acid: ~ ; 5.8 pH: : 4.3 : Water & minors: up to 100%
:; ~ .
An identical composition is also made, except it comprises in addition 1.5% of Ukanil R.

..
S~ r~TU~E SHEET

;
.

W092/22628 . Pcr/us92/o4772 2110~13 lo The viscosity of both compositions is then measured at 60rpm shear rake, at different temperatures. The results are reported in Fig. 1. This graph shows that the composition without Ukanil R presents the phase stability problem as from .:
13~C and below, whereas in the same time, the composition ..
with Vkanil R raises in viscosity as the temperature decreases, but remains stable. Also, one can notice that, at all temperatures, the composition with Vkanil ~ is somewhat .
mor~ viscous than the composition without.

, .

.

, .
: ' ~UBSTITUTE SHEI~T

Claims

What is claimed is:

1. A self-thickened aqueous cleaning composition having a viscosity of from about 50 to about 700 cps at 60rpm shear rate at 20°C, comprising from about 1% to about 25%
by weight of the total composition of an alkyl sulphate anoinic surfactant derived from natural coconut oil, from about 0.1% to about 8% by weight of the total composition of ammonium salts and from about 0.5% to about 25% by weight of the total composition of a compound of the structure :
, wherein :

- R1 is a C1-C25 alkyl or alkenyl group;
- R2 is a C2-C4 aliphatic hydrocarbon chain;
- R3 is a methyl of ethyl monosubstituted C2-C4 aliphatic hydrocarbon chain;
- R4 is a C1-C25 alkyl or alkenyl or carboxyl chain, or H;
- n is an integer of from 1 to 10:
- m is an integer of from 0 to 20;
or mixtures thereof.

2. A composition according to claim 1, wherein - R1 is a C10-15 alkyl chain;
- R2 is ethylene;
- R3 is a methyl substituted ethylene;
- R4 is H;
- n is an integer of from 1 to 5;
- m is an integer of from 0 to 10, or mixtures thereof.

3. A composition according to claim 1 which comprises from about 0.6 % to about 10% by weight of the total composition of said compound.

4. A composition according to claim 1 which comprises from about 2% to about 8% by weight of the total composition of said alkyl sulphate anionic surfactant.

5. A composition according to claim 1 which comprises from about 0. 2% to about 6% by weight of the total composition of ammonium salts.

6. A composition according to claim 1 which has a viscosity in the range of from about 80 cps to about 350 cps at 60rpm shear rate at 20°C.

7. A composition according to claim 1 which has a pH as is in the range of from about 1 to about 6.

8. A composition according to claim 7 which has a pH as is in the range of from about 2.5 to about 5.

9. A composition according to claim 1 which further comprises from about 0.5% to about 20% by weight of the total composition of citric acid.

10. A composition according to claim 1 which further comprises from about 0.01% to about 0.5% by weight of the total composition of a capped 1,2-propylene terephthalate polyoxyethylene terephthalate polyester of the formula wherein n is an integer of from about 12 to 43 and u is an integer of from about 2 to 8, and mixtures thereof.

11. A composition according to claim 1 which further comprises from about 1% to about 15% by weight of the total composition of hydrogen peroxide.

12. A process for the manufacturing of a composition according to claim 9 which comprises the steps of dissolving the citric acid in water separately from the remainder of the composition, adjusting the pH of the citric acid solution to the target pH value of the final composition, and adding said pH adjusted citric acid solution to the remainder of the composition, the pH of which having been separately adjusted to said pH target value.

13. A process according to claim 12 wherein, as a final step hydrogen peroxide is added on top of the remainder of the composition including the citric acid.

14. The composition according to claim 3, wherein said compound is from 0.7% to 2% by weight of the total composition.

15. The composition according to claim 4 wherein said alkyl sulphate anionic surfactant is from 3% to 5% by weight of the total composition.

16. The composition according the claim 5 wherein said anionic salts is from 0.2% to 6% by weight of the total composition.

17. The composition according to claim 11 wherein said hydrogen peroxide is from 2% to 10% by weight of the total composition.

18. The composition according to claim 17 wherein said hydrogen peroxide is from 3% to 8% by weight of the total composition.