GB2316087A

GB2316087A - Lotion bar

Info

Publication number: GB2316087A
Application number: GB9616479A
Authority: GB
Inventors: Pravin Chauhan; Mark Davey; May Yang
Original assignee: Cussons International Ltd
Current assignee: Cussons International Ltd
Priority date: 1996-08-06
Filing date: 1996-08-06
Publication date: 1998-02-18
Also published as: GB9616479D0

Abstract

A lotion bar comprises from 5 to 40% by weight of a surfactant system comprising anionic surfactant and nonionic surfactant selected from alcohol ethoxylates, alkyl polyglucosides or fatty acid esters. The lotion bar further comprises from 10 to 80% by weight of water-insoluble material.

Description

LOTION BAR The present invention relates to a lotion bar.

Traditional cleansing can be broadly divided between the use of liquid products such as shower gels, liquid soaps and facial washes, and the use of solid products, for example soap and syndet bars. Although bars have traditionally been the main cleansing product used by the consumer, a trend is now very apparent in many of the more developed countries towards the use of liquid products. Much of this is down to the convenience aspect, for example of shower gels, and also to the perceived image of soap bars, soap having a reputation for drying the skin.

This trend is particularly highlighted by the growth of facial cleansing products as replacements for soap for facial washing. Although bars based on synthetic detergents, such as sodium cocoylisethionate, instead of soap have been developed and are proven to be milder than soap, the perception of these products is that they are still soap (albeit milder) and thus they have not stopped this trend for facial washing.

The alternative to this is the development of lotion bars which produce a lotion of composition similar to commercial cleansing lotions. Such products do exist and are best exemplified by Patent Application No. WO 89/08444.

Although these bars are obviously formulated to give gentler cleansing, the key performance criteria must still remain that the skin is cleansed. With their usage being in a large part for the face, the removal of make-up is obviously a key factor. The problem with this technology is that cleansing is compromised as compared to standard toilet bars.

The other disadvantage with the technology is that the sole use of the anionics used does not allow for the development of soap-free bars which deliver satisfactory lotion characteristics.

The present invention has been made from a consideration of these problems and seeks to provide lotion bar technology which has a better cleansing performance than current, known technology whilst delivering a lotion bar which is still acceptable to the consumer. These bars may, or may not, be soap-free. Equivalent lotion characteristics can be coloured with either soap-free bars or bars containing soap.

According to the present invention there is provided a lotion bar comprising from 5 to 40 MO by weight of the total composition of a surfactant system consisting essentially of at least one anionic surfactant and at least one nonionic surfactant, said lotion bar further comprising from 10 to 80% by weight of the total composition of at least one water-insoluble material, wherein the said nonionic surfactants are selected from any of the following: alcohol ethoxylates, alkyl polyglucosides or fatty acid esters.

The combination of the anionic surfactant, the selected nonionic surfactants and the water insoluble materials acts to enhance the cleansing performance of the lotion produced whilst building the lotion structure which is perceived by the consumer as creaminess (compared to technology in which the sole surfactant type is anionic). These bars may or may not, be soap-free, equivalent lotion characteristics being achievable with both bar types. The lotion bars of the invention further exhibit enhance skin feel attributes.

In a preferred embodiment of the invention an amphoteric surfactant of chemical composition is used to give considerably enhanced bar hardness and lotion characteristics; i.e. lotion structure and skin feel. The bar of the invention preferably comprises from 0 to 20% by weight of amphoteric surfactants and more preferably from 5 to 15% by weight.

Bars of the present invention of good quality can be prepared on a standard production line.

The nonionic surfåctants preferably comprise any of the following either alone or in combination: alcohol ethoxylates having a chain length in the range C0 20 and ethoxylation in the range 3 to 50, more preferably C8.15 material of ethoxylation range 5 to 25, and still more preferably C9 1s material of ethoxylation 5 to 15; alkyl polyglucosides (APG) of chain length Cm ,6 with a polymerisation no. between 1.1 to 2.0 which give enhanced lotion characteristics and more preferably C8.14 material of polymerisation number 1.1 to 1.6; fatty acid ester such as sorbitan monostearate which is particularly beneficial for the building of lotion structure and emulsification. To maximise these properties the material may be ethoxylated so as to yield a HLB in the range of 4.0 to 16.0.

The anionic surfactant material preferably comprises any of the following either alone or in combination: monocarboxylic acid salts, ideally C12.18 fatty acids at levels from 1 to 50% by weight, more preferably between 10 and 40%, most preferably between 15 and 35%.

These salts are found to be very efficient at delivering the required lotion.characteristics; acylisethionates, ideally salts of C, l,; isethionates at levels between 1 and 20%, more preferably 5 and 15%, most preferably 5 and 12% which are found to be efficient at enhancing lotion characteristics in the soap-free bars of the invention; alkyl sulphates, ideally C,." alkyl sulphates (which may be substituted e.g.

ethoxylated ) at levels between 1 and 20%, more preferably between 5 and 15%, most preferably between 5 and 12%. These sulphates are found to be efficient at enhancing lotion characteristics. The use of magnesium lauryl sulphate, in particular was found to have benefits in soap-free formulations; C,,, alkyl sulphonates, alkylbenzene sulphonates or ether carboxylates.

The lotion bar preferably comprises from 15 to 40 /O by weight of the said surfactant system and more preferably from 25 to 40% by weight.

The water insoluble material preferably comprises C12/20 fatty alcohol and/or Cm2/20 fatty acid and their derivatives. The bar preferably comprises from 10 to 80% by weight, more preferably from 20 to 75% by weight and most preferably from 30 to 70% by weight of the water insoluble material.

In order to improve the binding ability of the product such-as to improve processability of the bar, the use of polyethylene glycol (PEG) material, preferably of minimum molecular weight 500 in combination with starch was found to be particularly beneficial. The use of these two materials in combination was found to exhibit a synergistic effect in improving the processability of the bar.

The use of certain amphoteric surfactants in these compositions was also found to be advantageous. Incorporation of a betaine surfactant was found to build lotion structure and also improve the hardness of the bar.

The skin feel of the product can be modified by the use of a range of known materials. Dimethicone was found to be particularly useful in enhancing the cushioned feel of the skin.

The invention will be described further by way of the following examples: Example 1 The following formulations were evaluated for their cleaning performance.

In all cases, the minor ingredients may include perfume, preservative system, salt, optical brightener, and water.

A B Soap* 31.2 26.5 Cetyl alcohol 26.8 27.5 Stearic acid 25.7 27.2 Cl38X5 7EO 0.0 4.5 alcohol ethoxylate Paraffin wax 4.0 3.2 Cetyl dimethicone 0.0 1.0 Glycerine 0.0 2.0 PEG 1000 1.5 0.0 Starch 1.5 0.0 TiO2 5.0 2.2 Minors 4.3 59 * - made from a blend of coconut and tallow fatty acids.

The method used to determine the cleaning performance of the products was the use of the Minolta chromameter to measure to determine the % of certain make-ups removed after washing. The make-ups used were lipstick, mascara, and eyeshadow - and oil soluble and water-soluble version of each was used.

An average was then taken of the results. From these results formulation B was shown to have a 30% improvement in the amount of make-up removed.

Example 2 The following examples are given to show the application of this technology to soap-free bars.

A B APG C10/12 7.5 9.0 MgLS 9.5 5.0 SCI 10.0 0.0 CAPB* 0.0 12.0 C11113 7EO 4.5 4.5 alcohol ethoxylate Cetyl alcohol 31.0 27.0 Stearic acid 27.0 27.0 Paraffin wax 3.0 3.0 Cetyl dimethicone 0.0 1.0 Glycerine 0.0 2.0 PEG 4000 2.0 0.0 PEG 1500 0.0 3.0 Starch 1.0 00 TiO2 0.6 2.0 Minors 3.9 4.5 * CAPB = cocamidopropyl betaine (Tegobetaine CK-D) Both of the above formulations gave bars that produced a lotion of the quality comparable to that produced using soap-containing formulations. The use of the betaine (B) gave a bar which was harder and had enhanced lotion characteristics (namely structure and skin feel).

Example 3 The following comparison demonstrates the benefit of using high levels of PEG in the formulation.

A B Soap* 27.0 22.0 Cetyl alcohol 28.0 22.0 Stearic acid 27.0 20.0 Cl 3 7EO 4.5 3.0 alcohol ethoxylate Paraffin wax 3.2 0.7 Cetyl dimethicone 1.0 0.0 Glycerine 2.0 2.0 TiO2 2.2 2.2 PEG 1000 0.0 25.0 Minors 5.1 3.1 The lotion from formulation B was a lot easier to produce than from A. This was confirmed by a rate of wear test - A had a r.o.w. of 4% whilst B had a r.o.w. of 13%.

No loss in the quality of the lotion or bar hardness was seen. Similar benefits were achieved by partial replacement of the stearic acid with coconut fatty acid.

It is to be understood that the above defined example of the invention is by way of illustration only. Many modifications and variations are possible.

Claims

1. A lotion bar comprising from 5 to 40% by weight of the total composition of a surfactant system consisting essentially of at least one anionic surfactant and at least one nonionic surfactant, said lotion bar further comprising from 10 to 80% by weight of the total composition of at least one water-insoluble material, wherein the said at least one nonionic surfactant is selected from any of the following: alcohol ethoxylates, alkyl polyglucosides or fatty acid esters.

2. A lotion bar as claimed in claim 1, wherein the lotion bar further comprises up to 20% by weight of amphoteric surfactant.

3. A lotion bar as claimed in claim 2, wherein the lotion bar comprises from 5 to 15% by weight of the amphoteric surfactant.

4. A lotion bar as claimed in any preceding claim, wherein the nonionic surfactant comprises any of the following either alone or in combination: alcohol ethoxylates having a chain length in the range C6 20 and ethoxylation in the range 3 to 50; alkyl polyglucosides of chain length Cm ,6 with a polymerisation number in the range from 1.1 to 2.0; or fatty acid ester.

5. A lotion bar as claimed in any preceding claim, wherein the nonionic surfactant comprises material which is ethoxylated so as to yield a HLB in the range of 4.0 to 16.0.

6. A lotion bar as claimed in any preceding claim, wherein the anionic surfactant comprises any of the following either alone or in combination: monocarboxylic acid salts, acylisethionates, alkyl sulphates, C8.18 alkyl sulphonates, alkylbenzene sulphonates or ether carboxylates.

7. A lotion bar as claimed in any preceding claim, wherein the water insoluble material comprises Cm2 20 fatty alcohol and/or C12.20 fatty acid, C12.20 fatty alcohol derivatives and Cm2 20 fatty acid derivatives.

8. A lotion bar as claimed in any preceding claim, wherein the bar comprises from 10 to 80% by weight of said water insoluble material.

9. A lotion bar as claimed in any preceding claim, wherein the lotion bar further comprises polyethylene glycol and starch.

10. A lotion bar substantially as described herein with reference to any of the examples.