Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-02-28
2002-05-28
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S159000, C510S497000
Reexamination Certificate
active
06395690
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to process for making liquid cleansers having large size droplets (i.e., >20 microns, preferably >50 microns). The process comprises passing a composition containing oil or oil/polymer blend through a screen or screens having openings of varying size.
BACKGROUND
Both the rinsing and after-wash skin sensation a product has on the skin can be perceived by many consumers. In many parts of the world, notably China, Japan and other parts of Asia, a soap-like rinsing property (e.g., soap-like “draggy” feeling) is perceived as being thoroughly cleansing and is highly preferred. Soft, smooth, moisturized after-wash skin feel is highly desirable and also preferred by most consumers around the world.
Deposition technologies to deliver after-wash moisturizing skin feel are widely described in various patents. Among these are included U.S. Pat. No. 5,716,920 to Wayne et al., WO 96/02224 A1 (assigned to Unilever), WO 96/17591 (assigned to Procter & Gamble), U.S. Pat. No. 6,066,608 to Glenn, Jr., U.S. Pat. No. 5,308,526 to Dias et al. and EP 0,648,111 B1 to Torres et al. In order to achieve the desirable after-wash skin benefits noted in these patents, the particle size, as described in the patents, has to be large than 20 micrometers.
In applicants copending application to Tsaur, filed on same date as the subject application, it has been found that the selection of the depositing moisturizing agents can be used to provide moisturizing liquids with soap-like rinsing attributes (e.g., as defined by “draggy” feel after certain number of counts). Specifically, by depositing large (e.g., 20-5000 micrometers), viscous (e.g., higher than 3000 cps at 30° C. at 1.0 S
−1
) drops of a blend of hydrophobic polymer and emollient oils, the desired skin-feel is obtained. Preferred hydrophobic polymers include high MW (i.e., MW >900, preferably >1000) C
2
-C
10
polyalkenes (e.g., polybutenes) and preferred oils which are mixable with the hydrophobic polymers include mineral oil, petrolatum, or triglycerides.
The use of hydrophobic polymers (e.g., polybutene) in shampoo and PW liquid compositions is not new as seen, for example, from U.S. Pat. No. 5,441,730 to Gough et al. and U.S. Pat. No. 5,580,550 to Gough et al.
WO 99109948 and WO 99/09950 (both assigned to Procter & Gamble) both disclose compositions in which polybutenes of MW 600 to about 1000 are used to enhance rinsability. Among the long, long recitation of optional ingredients which may be used is included hydrocarbons such as mineral oils and petrolatum (see WO 99109950 at page 27, line 16).
There is absolutely no teaching or suggestion in these references of the criticalities of the invention, e.g., specific selection of polymers which must have MW >900, preferably greater than 1000; using these necessarily in combination with oils of defined viscosity to obtain defined benefits; using critical size polymer/oil mixtures; and ensuring no more than certain level (less than 0.5%, preferably less than 0.3%) cationic is used (contrast with, for example, page 19, lines 12-13 of WO 99/09950 where cationic can be used up to levels as high as 3%).
U.S. Pat. No. 5,854,293 to Glenn, Jr. discloses liquid PW compositions containing large drop lipophilic moisturizing agent which agent may be a blend of petrolatum and polybutenes (column 3, lines 43-47).
Again, there is no recognition that polymers must be of certain size and certain molecular weight (e.g., higher than 900), that no more than certain amount of cationic may be used (contrast with column 5, lines 44-45) or that very specific criticalities will yield compositions which rinse well and provide “draggy” feel.
Finally, U.S. Pat. No. 5,869,070 to Dixon et al. disclose personal cleansing compositions containing skin moisturizing agent which is selected from the group consisting of petrolatum, hydrogenated polybutene and mixtures thereof, where ratio of petrolatum to polybetaine is 3:1 to 5:1. The composition also comprises 0.5 to 1.0 part polyquaternium 10 and 1 to 2.5 parts sodium polyacrylate. There is no recognition that, in process of making, specific criticalities, e.g., less than 0.5% cationic, must be met to achieve “draggy” feel as defined.
In general, the difficulty in preparing liquid cleansers having the desired large droplets of hydrophobic skin benefit agents (i.e., >20 micrometers) is recognized in patents such as U.S. Pat. No. 5,716,920 to Glenn, Jr. et al. Specifically, the large oil droplets tend to be destroyed during mixing, especially when the liquid cleanser is viscous and contains high level of surfactants.
Several methods have been described in the patent literature to make liquid cleansers containing large oil droplets. U.S. Pat. No. 5,716,920 discloses a complex coacervation method to encapsulate and to protect large oil droplets during the processing of liquid cleanser. U.S. Pat. No. 5,308,526 to Dias, WOP 96/17591 to Kacher and EP 0,648,111 B1 to Torres teach a single vessel process to make large oil droplet by mixing the hydrophobic skin benefit agent directly with the liquid cleanser in a mixing vessel at low shear mixing condition. WO 96/02224 to Jobling et al. and WO 96117591 described in- line static mixer for the processing of large oil droplets.
Unexpectedly, it has been found that liquid cleanser containing large oil droplets can be prepared simply by passing the cleanser through a screen or screens having specific size of openings. The size of oil droplets can be easily controlled by the number of screens and the size of the opening on the screen. The present invention relates to an in-line screen process for making liquid compositions containing large oil droplet with size in the range of 20 to 5000 micrometers.
BRIEF DESCRIPTION OF INVENTION
In a copending application, applicants have found that use of specific polymers (i.e., minimum tackiness defined by minimum viscosity) in combination with specific oils provide not only moisturizing benefits, but also can provide good rinsability and soap-like “draggy” feel desirable by many consumers. To provide perceivable wet and dry skin sensation, the drop size of polymer/oil blend in the liquid cleanser has to be larger than 20 microns, preferably larger than 50 microns. The subject invention provides for a process to make liquid cleanser containing droplets of oil, generally, or of the oil/polymer blend of the copending application with size larger than 20 micron, preferably larger than 50 micron using an in-line screen. To achieve large drop size, the viscosity of the oil or oil/polymer blend has to be higher than 3000 centistokes, preferably higher than 10,000 centistokes at 30° C. at 1.0 S
−1
.
More specifically, the subject invention comprises a process for making a personal cleansing composition having desirable rinsing and moisturization properties (and having soap-like rinsability according to separate copending application) wherein said process comprises:
(1) preparing a structured liquid cleanser (i.e., a liquid able to suspend 20 micron oil droplets without phase separation at R.T. for over 3 months) containing 5 to 35% by wt. of a surfactant composition having a viscosity higher than 200 stokes (e.g., 20,000 centistokes) measured at 0.1 S
−1
at 30° C.;
(2) separately mixing oil and optionally polymer to form oil or oil/polymer mixture with viscosity higher than 3,000 centistokes, preferably higher than 10,000 centistokes at 30° C. at 1.0 S
−1
;
(3) mixing or injecting 1 to 30% by wt. of oil or oil/polymer blend into 70 to 99% by wt. of said structured liquid cleanser to form oil or oil/polymer droplets having size larger than 100 micrometers, preferably higher than 200 micrometers; and
(4) passing the composition of step 3 through a screen having opening larger than 30 micrometers, preferably greater than 50 micrometers to make the final products;
wherein size of particle in step (3) is larger than size of opening of screen used in step (4).
The prepared final composition is stable at room temperature for over 3
Koatz Ronald A.
Ogden Necholus
Unilever Home & Personal Care USA , division of Conopco, Inc.
LandOfFree
Process for making mild moisturizing liquids containing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for making mild moisturizing liquids containing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for making mild moisturizing liquids containing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2905850