Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
1999-06-04
2002-03-26
Kelly, Cynthia H (Department: 1774)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S438000, C510S441000, C424S059000, C424S070900
Reexamination Certificate
active
06362146
ABSTRACT:
The present invention relates to personal washing compositions.
Increased awareness of the problems associated with exposure to UV radiation in sunlight has led to the much greater use of sunscreens.
Commercially available organic sunscreen products typically contain from about 3 to about 26% of one or more UV absorbing chemicals. These products are applied to the surface of the skin as a thin film, typically 10-15 &mgr;m, and the chemicals act as a filter to diminish the penetration of the harmful UV radiation to the cells of the epidermis. These sunscreens are typically applied in the form of a cream, oil, lotion, alcohol or gel carrier. However, the US Food and Drug Administration has only approved a limited number of such chemicals as “safe and effective” agents in protecting skin against UV radiation, and is now limiting the amount of such agents in compositions for topical administration.
Physical or inorganic sunscreens, on the other hand, comprise particles of a relatively physiologically inert sunblock, i.e. UV-absorbing, compound typically suspended in a cream or lotion. Materials frequently utilized for this purpose include kaolin, talc, titanium dioxide and zinc oxide. These physical sunscreens are typically messy and occlusive. Moreover they form a visible, opaque or coloured layer on the surface of the skin which may be cosmetically unacceptable. These products may also promote undesirable skin complaints.
In addition, such commercially available sunscreen products are only usually applied when the user thinks that they will be at risk from prolonged exposure to the sun. However, incidental exposure to the sun of skin which is not normally covered by clothing is also deleterious, and very few people bother to apply sunscreen to account for this.
Therefore, it is desirable to provide means of applying sunscreens to the skin or hair on a regular basis, to protect the skin from the deleterious effects of UV irradiation during casual exposure to sunlight without the need for separate application. The incorporation of sunscreens into personal washing compositions has been suggested. However, personal washing compositions are designed to remove any particulate or oily soil adhering to the skin or hair and, therefore, it is difficult to deliver oily or particulate materials, particularly sunscreens to the skin or hair from personal washing compositions.
Detergent compositions, for example shampoos, comprising an anionic surfactant, water-insoluble particles and a cationic polymer have been described in U.S. Pat. No. 3,580,853 (Parran), with the aim of depositing the particles onto the hair. In the detergent compositions described in that patent the cationic polymers are water-soluble cationic nitrogen containing polymers that have a molecular weight within the range from 2,000 to 3,000,000 and have a cationic charge density greater than 0.001 in aqueous solution. The “cationic charge density” of a polymer refers to the ratio of the number of positive charges on a monomeric unit of which the polymer is comprised to the molecular weight of said monomeric unit. The cationic charge density multiplied by the polymer molecular weight determines the number of positively charged active sites of a given polymer chain.
Although this patent gives an example of a toilet soap bar containing an organic sunscreen, a benzophenone based compound, the amount of deposition of the sunscreen onto the skin is not revealed.
EP-A-386 898 describes a shampoo composition which contains sunscreen materials. In order to increase their deposition onto the hair, a cationic polymer is added, and the preferred polymer is a cationic derivative of a polygalactomannan gum.
We have now found that the use of an encapsulated sunscreen provides better deposition than the use of solid or liquid sunscreens. Further, surprisingly, we have found that the higher proportion of encapsulating material to sunscreen, while maintaining the amount of sunscreen in the final product constant, greatly enhances the proportion of sunscreen deposited.
Thus, according to a first aspect of the present invention, there is provided a personal washing composition containing
a) surface active agent selected from anionic, nonionic, zwitterionic and cationic surfactants, soaps and mixes thereof;
b) polymeric deposition aid;
c) encapsulated sunscreen.
In further aspects this invention provides a process for washing human skin, using such a composition, and the use of such a composition for cleaning skin whilst depositing sunscreen on the skin.
Features of the invention, including various optional and preferred possibilities will now be discussed in more detail.
In personal washing compositions of the invention, the surface active agent can be selected from any known surfactant suitable for topical application to the human body. Mild surfactants, i.e. surfactants which do not damage the stratum corneum, the outer layer of skin, are particularly preferred.
One preferred anionic surfactant is fatty acyl isethionate of formula:
RCO
2
CH
2
CH
2
SO
3
M
where R is an alkyl or alkenyl group of 7 to 21 carbon atoms and M is a solubilising cation such as sodium, potassium, ammonium or substituted ammonium. Preferably at least three quarters of the RCO groups have 12 to 18 carbon atoms and may be derived from coconut, palm or a coconut/palm blend.
Another preferred anionic surfactant is alkyl ethoxy sulphate of formula:
RO(CH
2
CH
2
O)
n
SO
3
M
where R is an alkyl group of 8 to 22 carbon atoms, n ranges from 0.5 to 10 especially 1.5 to 8, and M is a solubilising cation as before.
Other possible anionic surfactants include alkyl glyceryl ether sulphates, sulphosuccinates, taurates, ethoxylated taurates, sarcosinates, sulphoacetates, alkyl phosphate, alkyl phosphate esters and acyl lactylate, alkyl glutamates, alkyl glycinates, alkyl sulphates, alkyl succinates, N-alkoyl sarcosinates, alkyl ether carboyxlates, alpha-olefin sulphonates, mono and di-alkyl phosphates, especially their sodium, magnesium, ammonium, and mono-, di, and triethanolamine salts, and mixtures thereof.
Sulphosuccinates may be monoalkyl sulphosuccinates having the formula: R
5
O
2
CCH
2
CH(SO
3
M)CO
2
M; and amido-MEA sulphosuccinates of the formula: RCONCH
2
CH
2
O
2
CCH
2
CH(SO
3
M)CO
2
M; wherein R
5
ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl and M is a solubilising cation.
Sarcosinates are generally indicated by the formula: R
5
CON(CH
3
)CH
2
CO
2
M, wherein R ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl and M is a solubilising cation.
Taurates are generally identified by the formula: R
5
CONR
6
CH
2
CH
2
SO
3
M, wherein R
5
ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl, R
6
ranges from C
1
-C
4
alkyl, and M is a solubilising cation.
If the surface active agent comprises soap, the soap is preferably derived from materials with a C
8
to C
22
saturated and/or unsaturated carbon chain and, preferably, is a potassium soap with a C
12
to C
18
carbon chain.
Mixtures of any of the foregoing surface active agents may also be used.
It is also preferable that the composition includes at least one cosurfactant agent with skin-mildness benefits. Suitable materials are zwitterionic detergents which have an alkyl or alkenyl group of 7 to 18 carbon atoms and comply with an overall structural formula
where R
1
is alkyl or alkenyl of 7 to 18 carbon atoms; R
2
and R
3
are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms; m is 2 to 4; n is 0 or 1; X is alkylene of 1 to 3 carbon atoms optionally substituted with hydroxyl; and Y is —CO
2
or —SO
3
.
Zwitterionic detergents within the above general formula include simple betaines of formula:
and amido betaines of formula:
where m is 2 or 3.
In both formulae R , R and R are as defined previously. R
1
may, in particular be a mixture of C
12
and C
14
alkyl groups derived from coconut so that at least half, preferably at least three quarters of the groups R
1
have 10 to 14 carbon atoms. R
2
and R
3
are preferably methyl.
A further possibility is a sulphobet
Garrett Dawn
Kelly Cynthia H
Koatz Roland A.
Unilever Home & Personal Care USA , division of Conopco, Inc.
LandOfFree
Personal washing compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Personal washing compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Personal washing compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2843277