Oil in water emulsions

A novel oil in water emulsion composition comprising of two alkoxylated esters and a neopentanoate ester in varied ratios to produce unique and unexpected properties in formulations. Water thin emulsions, deodorant milk emulsions, dry skin lotion and sunscreen emulsion with high unexpected SPF results are a direct result in the use of this emulsion system in the formulation.

BACKGROUND OF THE INVENTION 
The inventor's initial goal was to discover a water dispersible, self 
emulsifying surfactant that would be oil soluble and simultaneously have 
emollient properties with a desirable skin feel. This surfactant when 
added to H.sub.2 O at room temperature would form its own oil in H.sub.2 O 
emulsion and at the same time appear and feel like a cosmetic skin lotion. 
In addition, the surfactant would be stable, safe and effective at use 
concentrations. 
The result of this effort is U.S. Pat. No. 4,559,226 which introduced at 
least two self-emulsifying alkoxylated esters having the structural 
formula: 
##STR1## 
trade name: Hetester.RTM. PCA 
##STR2## 
trade name: Hetester.RTM. PHA. 
Increasing the hydrophilic portion of structure b, to cause water 
solubility, the resulting compound has the following structure: 
##STR3## 
trade name: CUPL.RTM. PIC for which Patent Applications have been 
submitted. 
The resulting compound, that is, CUPL.RTM. PIC became a fragrance 
solubilizer and oil in water emulsifier. 
The aforementioned Hetesters.RTM. proved to be excellent oil in water 
emulsififers, emulsifying at least twice their own weight in oil. They 
further proved to be excellent pigment wetters and dispersers. 
Both the Hetester.RTM. & CUPL.RTM. are synthesized and do not contain any 
animal derived components. They are free of phenolic and oleic groupings. 
These properties result in non-distortion of fragrances, less tachiness 
and excellent safety scores. 
Recently, U.S. Pat. No. 5,116,604 was issued. The preferred embodiment of 
this invention has the following structure: 
##STR4## 
Trade name: Elefac.RTM.. 
This unique ester was produced by using a specific C-20 alcohol clearly 
defined in the Patent. The use of this specific C-20 alcohol resulted in a 
neopentanoate ester with an exclusive extraordinary emolliency that 
significantly enhances sun protective factor (SPF) of a sunscreen 
formulation. In addition, it has these desirable properties: clear, 
low-freezing liquid, good color, odor, non-comedogenic, stable and safe. 
It is also a moisturizer and pigment wetter for cosmetic products. 
Progressing further,various uses of the Hetester.RTM. and CUPL.RTM. 
surfactants in combination with the oil soluble ester, Elefac.RTM., gave a 
water thin, oil in water emulsion without the need for stabilizing water 
dispersible thickeners. The emulsion thus formed was stable for 3 months 
at 50.degree. C. and had a perfect freeze/thaw stability.

OBJECTS AND SUMMARY OF THE INVENTION AND DESCRIPTION OF THE INVENTION 
It is the object of this invention to introduce a new and novel emulsion 
system containing a combination of three basic components: 2 surfactants 
of different hydrophilicity in combination with a unique neopentanoate 
ester made from a specific alcohol. 
Using this combination gives water thin oil in water emulsion without the 
use of water dispersible gums. The emulsion system alone scored an SPF of 
4.35 on 20 people without any active sunscreen present. 
It is another object of the instant invention to thicken this "water thin" 
emollient milk, add Parsol MCX which resulted in the unexpected property 
of an SPF reading of 13 in 20 people when an SPF of 8 is expected. 
Another object of the invention is to make a PABA, PABA derivative, 
Benzophenone-3,water soluble sunscreen free formula which was 
accomplished. Using the emulsion system and Parsol MCX and Parsol 1789 
resulted in SPF of 17 on 20 people. This result was accomplished without 
using the forementioned undesirable sunscreens which again, was higher 
than expected. 
Formula F-6-39-1, F-6-46-1 , F-7-1-1, and F-7-1-3 are illustrative 
formulas. 
This is the point and thrust of the invention. A unique emulsion system 
which gives unexpected SPF properties. The unexpected SPF results are 
additive from the combination of the emulsion system introduced and the 
sunscreens added. 
The goal of any emulsion chemist is to produce a water thin stable oil in 
H.sub.2 O emulsion without the use of any water soluble or dispersable 
thickeners. The present system introduced in the instant invention brings 
to fruition this goal. Also an added benefit is the ability to form this 
emulsion at 38.degree. C.