Method for inhibiting corrosion in an aqueous aerosol or foam hair styling composition

Abstract

A method for improving the corrosion resistance of aerosol or foam hair spray formulations in metal containers is disclosed. In particular, the present invention involves the use of phosphate ester emulsifiers in the preparation of the emulsion polymer hair fixative resins to provide corrosion resistance of the hair styling composition in metal containers without negatively affecting the performance of the hair styling product itself. Use of the selected emulsifiers is particularly useful in non-corrosive aqueous hair styling compositions containing low (80% or less) volatile organic compound (VOC) concentrations.

Description

[0001] The present invention relates to aerosol or foam hair styling compositions delivered from metal containers and a method of inhibiting corrosion of the metal container holding the hair styling composition. More particularly, the present invention relates to a method of inhibiting corrosion to tin plate or aluminum aerosol cans caused by the hair spray composition without compromising performance of the hair spray product or without the expense of special can liners. In a preferred embodiment, the present invention also relates to non-corrosive aqueous hair styling compositions containing low (80 weight percent or less) volatile organic compound (VOC) concentrations.[0002] Hair styling products, such as hair sprays, styling gels, spray gels and mousses are used on hair to hold the hair in place. The hair styling products, when applied, form a thin film or weld of resin on the hair, most efficiently in the seam between adjacent hair fibers or at a point where the fibers cross on...

AI Technical Summary

Benefits of technology

[0013] The method of the present invention is useful for improving the corrosion resistance of aerosol or foam hair styling formulations when the hair styling formulation is provided in metal containers, such as aerosol cans. We have found that the use of certain selected emulsifiers, that is, phosphate esters, in the preparation of the emulsion polymer hair fixative resins surprisingly improves the corrosion resistance of the hair styling composition in metal containers without negatively affecting the performance of the hair styling product itself.

[0029] The proportions of the monomers comprising the acrylic hair fixative resin are selected to provide for an optimum hydrophilic / hydrophobic balance. This optimum balance provides, especially in a low-VOC hair styling composition, curl retention under humid conditions, moisture resistance, shampoo removability, feel or stiffness, and desirable aesthetics to the hair, such as minimal flaking of the hair fixative resin.

[0050] Aerosol hair styling compositions may have pH values from 5 to 10, preferably from 6 to 9.5, and more preferably from 7 to 8.5. Although corrosion is generally less of a problem in aerosol containers for compositions having pH values above 8.5 (depending on the hair fixative resin composition), the higher pH values may detract from the overall hair fixative resin properties due to plasticization of the hair fixative resin. This may lead to poorer high humidity curl retention, lower stiffness and increased tackiness of the resin film on the hair. Residues from the hair fixative resin formulation (such as sulfate and sulfonate emulsifiers) may promote corrosion regardless of the pH. It is, therefore, advantageous to be able to formulate aerosol hair styling compositions at a pH that allows solubility or dispersibility in the hair styling formulation and good shampoo removability without overneutralizing (that is, increasing the pH) the hair fixative resin in the hair styling composition. Use of hair fixative resins prepared according to the method required by the present invention allows for improved corrosion resistance over a wide pH range without compromising hair styling performance of the hair fixative resin and also allows the hair styling composition formulator to use lower levels of conventional corrosion inhibitors, further lessening the likelihood of negatively affecting hair fixative resin performance.

Problems solved by technology

The presence of certain additives, such as those required to prepare a hair fixative resin (for example, emulsifiers, surfactants, chain transfer agents, initiators and redox agents) may accelerate corrosion to an extent that it cannot be inhibited even with a high concentration of corrosion inhibitors in the formulation or by increasing the pH.

These additives, being part of the polymer processing package, cannot be removed or replaced without negatively affecting the ability to prepare the polymer.

Although disclosing that water can be used in a hair styling composition containing the acrylic hair fixative resins, this reference does not disclose or suggest methods for overcoming the problems associated with hair styling compositions regarding corrosion.

U.S. Pat. No. 5,658,558, although disclosing how to improve the performance of acrylic resins in low-VOC systems, also does not disclose how to overcome corrosion problems.