WO1994019442A1

WO1994019442A1 - Toiletries composition

Info

Publication number: WO1994019442A1
Application number: PCT/EP1994/000491
Authority: WO
Inventors: David Anthony Clubley
Original assignee: The Boots Company Plc
Priority date: 1993-02-20
Filing date: 1994-02-18
Publication date: 1994-09-01
Also published as: AU6204094A

Abstract

A toilet bar comprises soap and/or detergent and a hydrophilic ionic acrylic copolymer in an amount sufficient to generate a moisturising lather when the bar is used with water and/or to reduce skin irritation/roughening. Preferably, the bar further comprises a medicinal grade white oil.

Description

TOILETRIES COMPOSITION

The present invention relates to a toiletries composition in the form of a toilet bar, and to a method of preparation of such a toilet bar.

The term 'toilet bar' as used herein denotes a substantially solid bar comprising soap and/or detergent. Such a bar is to be distinguished from liquid soaps and liquid detergent formulations. In particular, the term 'toilet bar' as used herein denotes a bar having a total surfactant content (whether soap and/or detergent) of at least 30% by weight and a water content of not more than 20% by weight.

A considerable interest has developed in the art in toilet bars having moisturising properties.

The present Applicant (The Boots Company PLC) has marketed soap bars comprising about 0.25% by weight of a cold cream concentrate comprising beeswax, light liquid paraffin, borax, chloroxylenol and water.

The Applicant has also marketed soap bars comprising between 1 and 2% of mineral oil (so-called 'Baby Soaps' ) .

However, as noted in WO90/13283 (Unilever PLC) , the use of moisturising agents in traditional toilet bars is limited inter alia by processing constraints. Thus, it is stated in this Unilever publication that: "Usually bars with a high content of moisturiser are sticky and cannot be easily stamped. Some of the difficulties of formulating a good personal washing product with high levels of moisturizers were eliminated by using liquid products to avoid the stamping problem" . Allied Colloids has described, in its marketing literature, a liquid hand soap and a facial wash comprising 7.2% and 7.7% by weight respectively of a blend of an anionic acrylic copolymer and a mineral oil available under the trade name 'Salcare SC91'. The blend used is described primarily as a thickener. It is suggested that the blend ^'may also give moisturising and softening effects and enhanced spreading.

At a presentation entitled "Liquid Grade Rheology Modifiers for Cosmetic Products" at the In-Cosmetics

Conference, Frankfurt (author N Ambrose, 4 March 1992), the properties of "Salcare" copolymer/oil blends were further discussed. The blends were described as

"rheology modifiers/thickeners" and it was stated that "creams and lotions" are "the obvious areas of use".

The functions of the blends were described as viscosifying, rheology altering, suspending/stabilising, gelling, conditioning (when cationic copolymers used) and opacifying. Various formulations were listed, including a liquid hand soap, post-perm conditioner, protein conditioner, moisturising lotion (in combination with Lanolin Alcohol and PEG-75 Lanolin) and hair conditioner.

EP-A-0526520 (3M) discloses a skin-cleansing composition comprising a non-water-soluble acrylate polmer that is soluble in poorly hydrogen bonding solvents or solvent blends.

EP-A-0186148 (Goodrich) discloses a toilet soap comprising a homopolymer of acrylic acid as a thickener.

According to the present invention, there is provided a toilet bar comprising a hydrophilic acrylic polymer comprising at least 10% by monomer mole ratio of monomer residues of formula I

R-.

wherein R^ to R^ are each independently C-_j__4 alkyl and n is an integer from 1 to 4 and X is a counter ion, such as a chloride or bromide ion; said polymer being present in the toilet bar in an amount sufficient to generate a moisturising lather when the bar is used with water and/or to reduce skin irritation.

The toilet bar generates an excellent creamy, moisturising lather in use, with excellent substantivity.

Preferably n is 2 and preferably R-_j_ to R₄ are each methyl.

Suitably, the polymer is a homopoly er, comprising substantially 100% monomer residues of formula I.

Alternatively, the polymer may be a copolymer of monomers based on formula I with other acrylate monomers, for example 2-propenamide.

The term "polymer" as used herein includes homopolymers and copolymers. For example, the polymer may be an ionic copolymer, preferably made up of ionic and non-ionic monomer units. Preferably, the polymer material is particulate and has a particle diameter range of from about 0.1 to about 2.0 microns, suitably from about 0.5 to about 1.0 microns, swelling to a range from about 0.5 to about 10 microns, suitably about 2.5 to about 5.0 microns when added to water. Suitably, the polymer is cross-linked.

Preferably, the ^' toilet bar further comprises an oil, suitably in the form of a medicinal grade white oil, suitably a vegetable oil, an ester, a silicone oil and/or a mineral oil such as a paraffin oil. This helps produce the excellent moisturising lather desired. Preferably the polymer is substantially insoluble in the oil.

Suitably, the polymer is present in the bar in an amount of from about 0.05 to 5% by weight.

Suitably, the oil is present in the bar in an amount of from about 0.05 to 5% by weight.

Suitably, the polymer and any oil are present in a ratio of between 5:1 to 1:5 suitably between about 2:1 to 1:2, preferably about 1:1 by weight.

Preferably, the toilet bar further comprises an activator in the form of a high HLB (hydrophilic/lipophilic balance) non-ionic surfactant such as a fatty alcohol ethoxylate.

A preferred source of both the polymer and the oil (in suitable proportions), is one or more of the formulations available under the trade name 'Salcare' from Allied Colloids, Bradford, UK. The polymer/oil blend 'Salcare SC91' includes an anionic acrylic copolymer, whilst the polymer/oil blend 'Salcare SC92' includes a cationic acrylic copolymer and the polymer/oil blend "Salcare SC95" includes a cationic acrylic homopoly er. Suitably, the toilet bar comprises between 0.1% and 10%, suitably between about 0.25% and 5%, suitably about 3% by weight of 'Salcare SC91', 'Salcare SC92' or "Salcare SC95", or a combination thereof.

The polymer/oil blend "Salcare SC92" comprises a cationic acrylic copolymer (having the CTFA designation "polyquaternium 32") dispersed in a medicinal grade white oil. More specifically it comprises a copolymer of ethanaminium,N,N,N-trimethyl-2-[ (2-methyl-l-oxo-2- propenyl)oxy] -chloride and 2-propenamide (CAS Number 35429-19-7) as a 50% dispersion in a carrier mineral oil meeting the requirements of 21 CFR Part 178.3620(a) and USP. It further comprises approximately 6% of a fatty alcohol ethoxylate as activator. The blend is manufactured by water-in-oil dispersion polymerisation.

The polymer/oil blend "Salcare SC95" comprises a cationic acrylic homopolymer (having the CTFA designation "polyquaternium 37") dispersed in a medicinal grade white oil. More specifically it comprises a polymer of ethanaminium-N,N,N-trimethyl-2-

[ (2-methyl-l-oxo-2-propenyl)oxy]chloride as a • 50% dispersion in a carrier mineral oil meeting the requirements of 21 CFR Part 178-3620(a) and USP. It further comprises approximately 6% of a fatty acid ethoxylate as activator. The blend is manufactured by water-in-oil dispersion polymerisation.

As noted above, the toilet bar of the present invention has a reduced skin irritancy (as measured, for example, by the so-called "Zein" test) .

As noted above, the toilet bar may comprise soap, detergent or a combination of both. There is also provided a method for producing a toilet bar as defined above by combining an effective amount of a polymer as defined above with soap and/or detergent as desired. Preferably, the polymer is added as a copolymer/mineral oil blend, such as the blend available from Allied Colloids (UK) under the trade name "Salcare".

In a further aspect, the invention provides a toilet bar comprising a hydrophilic acrylic polymer and a mineral oil. Suitably the polymer is part-neutralised polyacrylic acid.

The term 'soap' as used herein denotes the alkali metal or alkanol ammonium salts of aliphatic alkane monocarboxylic acids or alkene monocarbocylic acids, such as sodium, potassium, mono-ethanol ammonium cations, di-ethanol ammonium cations and tri-ethanol ammonium cations, or mixtures thereof. Sodium soaps are normally preferred but up to about 25% of the soaps used may be potassium soaps. Preferably the soaps are alkali metal salts of natural or synthetic alkanoic or alkenoic acids having from about 12 to 20 carbon atoms, preferably from about 12 to 18 carbon atoms.

Suitably, soaps having the fatty acid distribution of coconut oil may be used to supply the lower end of the broad molecular weight range. Soaps having the fatty acid distribution of tallow or palm oil may be used to supply the corresponding upper end of the range.

Preferred soaps have the fatty acid distribution of coconut oil or tallow, or mixtures thereof. In coconut oil soap, the proportion of fatty acids having at least 12 carbon atoms is about 85%. This proportion will be greater when mixtures of coconut oil and fats such as tallow, palm oil, or non-tropical nut oils or fats are used, since in the latter oils/fats the principal chain lengths are C-^g and higher. Preferred soap for use in the present compositions has at least about 85% fatty acids having 12 to 18 carbon atoms.

Coconut oil employed for the soap may be substituted in whole or in part by other "high-lauric" oils, that is, oils or fats in which at least 50% of the total fatty acids are lauric or rrryristic acids. Normally such oils are provided by the tropical nut oils of the coconut oil class, such as palm kernel oil, cohune oil, ouricuri oil, khakan kernel oil, tucum oil, murumuru oil, jaboty kernel oil, dika nut oil and babassu oil.

Suitably, the soap used is a mixture of about 10% to about 50% coconut oil and about 50% to about 90% tallow. These mixtures typically contain about 95% fatty acids having from about 12 to 18 carbon atoms.

The soaps may exhibit unsaturation but high levels of unsaturation are undesirable.

Soaps may be manufactured by the traditional "kettle boiling process" or more contemporary continuous soap manufacturing process in which natural oils and fats such as tallow or coconut oil or their equivalents are saponified by use of an alkali metal hydroxide in the manner well known to the skilled worker. Alternatively, the soaps may be made by neutralising fatty acids, such as lauric (C^)_* myristic (C-^) , palmitic (C₁₆) or stearic (C₁₈) acids by use of an alkali metal hydroxide or carbonate.

Detergents other than soap may be present in the composition either in addition to or in place of soap. Detergents may be selected from the alkali metal, magnesium or ammonium salts of C₁₂ - C₁₆ hydroxyalkane sulfonates, Cg - C-_j_g acyl isethionates, Cg - C_lg N-acyl taurinates, C₁₂ - C₁₈ alkyl sulfates, C-_₂ ~ C_lg alkyl ether sulfates, C-^ ~ i alkyl phosphonates and phosphates, C-_j_2 - ^g mono-alkyl succinates and aleates, Cg - C-^ dialkylsulfo-succinates, C^g - C_2Q alkane disulfonates, Cg - C-_]_ alkene sulfonates, and Cg- C^g sarcosinates.

Such detergents may act as skin mildness improvers and may be present in an amount of from about 0.5% to about 50% by weight of the bar, suitably from about 1% to about 25% by weight, preferably from about 2% to about 15% by weight, suitably from about 6% to about 15% by weight.

It will be appreciated by one skilled in the art that numerous further additives may also be included in the toilet bar. For example, a foam-boosting detergent salt may be incorporated, such as an alkali metal or organic amine higher aliphatic fatty alcohol sulfate, alkyl aryl sulfonate, or a higher aliphatic fatty acid taurinate.

A superfatting agent may be included to further enhance the lathering properties, for example, a Cg - C-_|_g, preferably a C_]__Q - C-^g fatty acid. Suitably such a superfatting agent is included in an amount of up to 25% by weight of the composition. For example, stearic acid may be incorporated to give enhanced skin feel and improved creaminess.

Preservatives may be included, such as organic sequestrants (e.g. EDTA and EHDP (ethanehydroxydiphos- phonic acid)), magnesium suphate and sodium silicate. Suitably, such preservatives are included in an amount of from 0.05% to 1% by weight, for example, about 0.1% by weight.

Fragrance may be included, suitably in an amount of from 0.25% to 2% by weight, for example, about 1% by weight.

Colouring agents may be included, such as water soluble dyes and/or pigments and pearlising agents such as titanium coated micas. Suitably such colouring agents are included in an amount of from 0.0001% to 0.01% by weight, for example, about 0.001% by weight.

Opacifying agents may be included, such as titanium dioxide, zinc oxide and magnesium carbonate. Suitably, such opacifying agents are included in an amount of from 0.01% to 2% by weight, for example, about 0.2% by weight.

Optical brightening agents may be included, such as disodium distyrylbiphenyl disulphonate (e.g. available under the trade name 'Tinopal CBS-X'). Suitably, such brightening agents are included in an amount of from 0.0005% to 0.01% by weight, for example, about 0.005% by weight.

Germicides may be included, such as triclosan, 3,4,4'-trichlorocarb-anilide and 3,4, 5-tribromo- salicylanilide. Suitably, these are included in an amount of from about 0.1% to 5% by weight, for example, about 1.5% by weight. Where triclosan is present, it is preferably included in an amount of about 0.3% by weight.

Scum dispersants may be included, such as sodium alkylbenzene sulphonates. Suitably, these are included in an amount of from about 0.5% to 10% by weight, for example, about 5% by weight.

Humectants may be included, such as glycerin. Suitably, these are included in an amount of from about 0.5% to 10% by weight, for example, about 2% by weight.

The invention also provides the use of a copolymer or copolymer/oil blend as defined above in a toilet bar to confer moisturising properties in use.

There is further provided a method of cleansing and/or moisturising the skin by use of a toilet bar as defined above.

It has also been found that, suprisingly, the polymer of the present invention reduces the skin irritancy of toilet bars.

Thus, there is further provided the use of a polymer or polymer/oil blend as defined above to reduce the skin irritancy of a chemical composition, preferably a toiletries or cosmetics composition such as a toilet bar.

The present invention will be understood with reference to the following non-limiting examples.

EXAMPLE 1

SOAP TOILET BAR

A soap toilet bar was formulated as follows:

Component % by weight

Toilet soap noodles

(sodium tallowate, sodium cocoate) 97.8

Tetrasodium EDTA 0.1

Titanium dioxide 0.1

Perfume 1.0 Blend of anionic acrylic copolymer and mineral oil (available from Allied

Colloids, UK, under the trade name

'Salcare SC91' ) 1.0

Pigment Yellow 1 0.0012 Pigment Green 7 0.0019

The 'Salcare' copolymer/oil blend, dye, titanium dioxide, EDTA and perfume were added to the soap noodles and mixed with a spatula until the noodles were evenly coated with the ingredients. The coated noodles were then milled to ensure thorough mixing before being plodded and stamped to provide the toilet bar.

EXAMPLE 2

SOAP TOILET BAR

A soap toilet bar was formulated as follows:

Component % by weight Toilet soap noodles

(sodium tallowate, sodium cocoate) 98.1

Tetrasodium EDTA 0.1

Titanium dioxide 0.1

Perfume 0.7 Blend of cationic acrylic copolymer and mineral oil (available from Allied Colloids, UK, under the trade name 'Salcare SC92') 1.0

Pigment Red 5 0.015

EXAMPLE 3

SOAP TOILET BAR

A soap toilet bar was formulated as follows:

Component % by weight

Toilet soap noodles 94.74 (sodium tallowate, sodium cocoate)

Tetrasodium EDTA 0.26

Titanium dioxide 1.0

Perfume 1.0 Blend of anionic acrylic copolymer and 3.0 mineral oil (available from Allied Colloids, UK, under the trade name "Salcare SC91")

The "Salcare" copolymer/oil blend, dye, titanium dioxide, EDTA and perfume were added to the soap noodles and mixed with a spatula until the noodles were evently coated with the ingredients. The coated noodles were then milled to ensure thorough mixing before being plodded and stamped to provide the toilet bar.

EXAMPLE 4

SOAP TOILET BAR

A soap toilet bar was formulated in the manner described above to the following composition:

Component % by weight

Toilet soap noodles (sodium tallowate, 94 . 74 sodium cocoate)

Tetrasodium EDTA 0 . 26

Titanium dioxide 1 . 0 Perfume 1 . 0

Blend of cationic acrylic copolymer and 3 . 0 mineral oil (available from Allied Colloids, UK, under the trade name "Salcare SC92")

EXAMPLE 5

DETERGENT TOILET BAR

A detergent toilet bar was formulated in the manner described above to the following composition:

Component % by weight Blend of sodium cocoylisethionate, sodium lauryl sulphosuccinate, superfatting and binding agents (available under the trade name 'Tensianol 399 SCI/LSA') 97.75 Blend of anionic acrylic copolymer and mineral oil (available from Allied Calloids, UK, under the trade name 'Salcare SC91') 1.0

Perfume 0.75 Titanium dioxide 0.5 EXAMPLE 6

SOAP TOILET BAR

Component % by weight

Toilet soap noodles (sodium tallowate, 94.79 sodium cocoate)

Titanium dioxide (available under the 1.0 Trade Designation "A-HR") Tetrasodium EDTA 0.26

Fragrance 1.25v

Blend of cationic acrylic homopolymer 2.7 and mineral oil (available from Allied Colloids, UK, under the Trade Name "Salcare SC95")

The toilet bar produced was observed to become less 'mushy' in use compared to corresponding toilet bars produced without the 'Salcare' blend of polymer and mineral oil.

COMPARATIVE TEST A

"Zein" skin-irritancy test

A "Zein" skin-irritancy test was carried out as described in Invittox Protocol Number 26 ("The Zein Test"; Invittox, (F.R.A.M.E. ) , 34 Stoney Street, Nottingham NG1 INB, England) . The test compared toilet bar A (prepared as in Example 4 above) with a corresponding toilet bar (B) from which the copolymer/oil blend only had been omitted. The Zein test determines the extent to which surfactants cause solubilisation of a water insoluble corn protein called zein. Zein is similar to the proteins of human hair and skin. It has been found that zein solubility in surfactant solutions correlates with surfactant skin irritation (Gott E, "Hautvertalichkeit von tensiden, gemessen an lόsevermόgen fur zein, 4th International Congress on Surfactants, Volume III, p 83) .

The results of the test were as follows:

Zein number (mg N/100 ml)

Toilet bar A 445 Toilet bar B 561

A lower zein number predicts reduced skin irritation/skin roughness when a particular surfactant solution is applied to skin. Thus, this test suggests that a toilet bar prepared in accordance with the present invention will exhibit reduced skin irritancy in use.

Claims

1) A toilet bar comprising a hydrophilic acrylic polymer comprising at least 10% by monomer mole ratio of monomer residues of formula I

CCH₂)n

E₂-N-R₄

R-

wherein R-_ to R₄ are each independently -^_^ alkyl and n is an integer from 1 to 4 and X is a counter ion; said polymer being present in an amount sufficient to generate a moisturising lather when the bar is used with water and/or to reduce skin irritation.

2) A toilet bar as claimed in Claim 1 wherein n is 2 and R-_ to R₄ are each methyl.

3) A toilet bar as claimed in Claim 1 or Claim 2 wherein the polymer is a homopolymer, comprising substantially 100% monomer residues of formula I.

4) A toilet bar as claimed in Claim 1 or Claim 2 wherein the polymer is a copolymer with 2-propenamide.

5) A toilet bar as claimed in any one of the preceding claims wherein the polymer is cross-linked.

6) A toilet bar as claimed in any one of the preceding claims wherein the polymer is particulate and has a particle diameter range of from about 0.1 to about 2.0 microns .

7) A toilet bar as claimed in any one of the proceding claims wherein the polymer is present in the bar in an amount of from about 0.05 to 5% by weight.

8) A toilet bar as claimed in any one of the preceding claims which further comprises a medicinal grade oil.

9) A toilet bar as claimed in Claim 8 wherein the polymer and oil are present in a ratio of from between about 5:1 to about 1:5 by weight.

10) A toilet bar as claimed in Claim 8 or Claim 9 wherein the medicinal grade oil is mineral oil .

11) A toilet bar as claimed in any one of the preceding claims which further comprises an activator in the form of a high HLB non-ionic surfactant.

12) A toilet bar as claimed in any one of the preceding claims which comprises a mixture of homopolymers and copolymers .

13) The use of a polymer as defined in Claim 1 to reduce skin irritation and/or to assist in lather generation in a toilet bar.

14) A toilet bar comprising a hydrophilic acrylic polymer and a mineral oil.

15) A toilet bar as claimed in Claim 14 wherein the acrylic polymer is part-neutralised polyacrylic acid.