Title:  O/W/O type multiphase emulsion

United States Patent:  6,150,425

Assignee:  Shiseido Company, Ltd. (Tokyo, JP)

Filed:  March 15, 1999

PCT NO:  PCT/JP98/03187

102(e) Date:  March 15, 1999

PCT PUB. Date:  January 28, 1999

Foreign Application Priority Date:  Jul 17, 1997[JP] (9-208458); Jul 17, 1997[JP] (9-208459)

An O/W/O type multiple emulsion in which an O/W type emulsion is dispersed in the outer phase oil wherein the O/W type emulsion in the inner phase contains water, an oil based ingredient, a surfactant and an amphiphilic substance chosen from those which can form a gel at ordinal temperature or higher in an amphiphilic substance-surfactant-oil-water system or N-long chain acyl acidic amino acid monosalt and an amphiphilic substance chosen from those which can form a gel at ordinal temperature or higher in an amphiphilic substance-N-long chain acyl acidic amino acid monosalt-oil-water system, said outer phase oil contains organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or lower, and the weight ratio of the O/W type emulsion and the outer phase oil is 2:3-19:1. An O/W/O type multiple emulsion with superior stability over time and good usability.

DISCLOSURE OF THE INVENTION

That is, the first invention of the present application provides an O/W/O type multiple emulsion in which an O/W type emulsion is dispersed in the outer phase oil wherein the O/W type emulsion in the inner phase contains water, an oil based ingredient, a surfactant and an amphiphilic substance chosen from those which can form a gel at ordinal temperature or higher in an amphiphilic substance-surfactant-oil-water system, said outer phase oil contains organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or lower, and the weight ratio of the O/W type emulsion and the outer phase oil is 2:3-19:1.

Also, the present invention provides the afforementioned O/W/O type multiple emulsion wherein said amphiphilic substance is composed of a higher fatty acid and/or higher alcohol whose carbon chain has a carbon number of 12 or more.

Furthermore, the present invention provides the aforementioned O/W/O type multiple emulsion wherein the surfactant contained in said inner phase O/W type emulsion is composed of a metal soap of a higher fatty acid.

Also, the present invention provides the aforementioned O/W/O type multiple emulsion wherein said organophilic modified clay minerals are obtained by treating a water swelling clay mineral with a quaternary ammonium type cation surfactant and a nonionic surfactant.

Also, the present invention provides the aforementioned O/W/O type multiple emulsion wherein the amphiphilic substance contained in the O/W type emulsion dispersed in said outer phase oil is a higher alcohol and higher fatty acid, the surfactant is a metal soap prepared by neutralizing said higher fatty acid, and said amphiphilic substance is contained in the inner phase oil of the O/W type emulsion in the amount of 0.1-80 wt %.

Furthermore, the present invention provides a method of preparing the O/W/O type multiple emulsion comprising a process in which the oil based ingredient which is to be the inner oil is added to an aqueous solution containing a neutralizing agent and the O/W type emulsion is prepared by a high pressure emulsification treatment or an ultrasonic emulsification treatment and a process in which said O/W type emulsion is dispersed and emulsified in the oil based ingredient which is to be the outer phase oil and contains an organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or less.

The second invention of the present application provides an O/W/O type multiple emulsion in which an O/W type emulsion is dispersed in the outer phase oil wherein the O/W type emulsion in the inner phase contains water, an oil based ingredient, N-long chain acyl acidic amino acid monosalt and an amphiphilic substance chosen from those which can form a gel at ordinal temperature or higher in an amphiphilic substance-N-long chain acyl acidic amino acid monosalt-oil-water system, said outer phase oil contains organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or lower, and the weight ratio of the O/W type emulsion and the outer phase oils is 2:3-19:1.

Also, the present invention provides the afforementioned O/W/O type multiple emulsion wherein said amphiphilic substance is composed of a higher fatty acid and/or higher alcohol whose carbon chain has a carbon number of 12 or more.

Furthermore, the present invention provides the aforementioned O/W/O type multiple emulsion wherein the N-long chain acyl acidic amino acid monosalt contained in said inner phase O/W type emulsion is N-stearoyl-L-glutamic acid monosalt.

Also, the present invention provides the aforementioned O/W/O type multiple emulsion wherein said inner phase O/W type emulsion contains an N-long chain acyl acidic amino acid disalt and its content is such that the mole ratio is 0.25 or less of that of the N-long chain acyl acidic amino acid monosalt.

Furthermore, the present invention provides the aforementioned O/W/O type multiple emulsion wherein wherein the content of the inner phase oil in the O/W type emulsion is half or more of the total of said amphiphilic substance and N-long chain acyl acidic amino acid monosalt.

Also, the present invention provides the aforementioned O/W/O type multiple emulsion wherein said amphiphilic substance and the N-long chain acyl acidic amino acid monosalt are present on the oil drop interface of the O/W type emulsion and the amount measured by using the DSC peak area ratio is 90% or more of the total content.

Furthermore, the present invention provides the aforementioned O/W/O type multiple emulsion wherein the total amount of said amphiphilic substance and the N-long chain acyl acidic amino acid monosalt is 0.2 wt % or more of the water phase of the O/W type emulsion.

Also, the present invention provides the aforementioned O/W/O type multiple emulsion wherein said organophilic modified clay minerals are obtained by treating a water swelling clay mineral with a quaternary ammonium type cation surfactant and a nonionic surfactant.

Furthermore, the present invention provides a method of preparing the O/W/O type multiple emulsion comprising a process in which the oil based ingredient which is to be the inner oil is added to the water phase containing an N-long chain acyl acidic amino acid monosalt and then the O/W type emulsion is prepared by a high pressure emulsification treatment or an ultrasonic emulsification treatment and a process in which said O/W type emulsion is dispersed and emulsified in the oil based ingredient which is to be the outer phase oil and contains an organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or less.

Claim 1 of 53 Claims

What is claimed is:

1. An O/W/O type multiple emulsion in which an O/W type emulsion is dispersed in the outer phase oil wherein the O/W type emulsion in the inner phase contains water, an oil based ingredient, a surfactant and an amphiphilic substance chosen from the group consisting of those which can form a gel at ordinal temperature or higher in an amphiphilic substance-surfactant-oil-water system, said outer phase oil contains organophilic modified clay minerals and an emulsifying agent with a HLB of 7 or lower, and the weight ratio of the O/W type emulsion and the outer phase oil is 2:3-19:1.

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