JPH0579044B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to water-in-oil (hereinafter referred to as W/O) makeup cosmetics, and more specifically, to cosmetics with excellent storage stability and skin safety over a wide temperature range. The present invention relates to a W/O makeup cosmetic composition having properties.

[Prior Art] Conventionally, as cosmetics such as creams, milky lotions, and foundations, so-called W/O emulsion compositions in which aqueous particles are dispersed in an oil phase are generally used as oil-in-water (O/W) compositions. ) It is known that it has advantages over emulsified compositions, such as protecting the skin, imparting flexibility, and being difficult to remove when bathed in water.

However, W/O emulsion compositions have the disadvantage of poor storage stability compared to O/W emulsion compositions. Generally, emulsion compositions are separated by creaming (or precipitation), aggregation, or coalescence of emulsion particles. arise. In a W/O emulsion composition, water droplets tend to aggregate at low temperatures, resulting in a syneresis phenomenon, that is, the oil phase, which is a continuous layer, tends to separate into an upper layer.
On the other hand, at high temperatures, the particle size increases due to the coalescence of water droplets.
As a result, water droplets precipitate, leaving only the oil phase in the upper layer, which tends to separate the oil phase. If the coalescence proceeds further, separation of the aqueous phase will occur. Therefore, it has been difficult to obtain a W/O emulsion composition that is stable over a wide temperature range. In particular, relatively stable W/O emulsion compositions can be obtained using non-polar oils such as paraffin oil, but these also lack stability over a wide temperature range, and furthermore, non-polar oils such as olive oil Regarding polar oils, even the stability at room temperature was not satisfactory.

Particularly in the case of cosmetics containing various pigments such as make-up cosmetics, it is difficult to ensure not only emulsion stability but also dispersion stability of the pigments.

Conventionally, emulsified compositions have generally been emulsified using surfactants. Surfactants are a group of substances that have a hydrophilic group and a lipophilic group in one molecule and exhibit surfactant ability, and have high solubility in base materials and strong permeability into the skin. Therefore, it may lead to skin irritation for some people.

[Problems to be Solved by the Invention] In view of the above circumstances, the present inventors have conducted intensive research with the aim of obtaining a W/O makeup cosmetic with excellent storage stability and good safety. The present inventors have discovered that the above object can be achieved by using a fine particle-sized organic polymer powder as an emulsifier without the need for the combined use of conventionally used surfactants, leading to the completion of the present invention.

[Means for Solving the Problems] That is, the present invention is a water-in-oil makeup cosmetic containing a polymethacrylic acid alkyl ester having an average particle size of 0.01 μm to 1 μm.

The present invention differs from the conventional concept of dissolving a surfactant in a base to emulsify an oil phase and an aqueous phase.
It is based on a completely new concept of emulsifying an oil phase and an aqueous phase by directly dispersing a solid with emulsifying ability in a base.

This emulsification method is not affected by the polarity of the oil phase, and does not require the conventional complicated procedure of selecting surfactants based on the HLB (hydrophilic/lipophilic) balance. Furthermore, since the organic polymer fine powder is a substance that does not dissolve in either the water phase or the oil phase, the balance of the system is less likely to be disrupted even when various pigments are added, and pigment aggregation is less likely to occur.
Furthermore, it has good safety to the skin and is clearly superior to lipophilic surfactants such as glycerin fatty acid ester and sorbitan fatty acid ester, which have been widely used in the past.

The configuration of the present invention will be described below.

Polymethacrylic acid alkyl esters used in the present invention include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, octyl methacrylate, decyl methacrylate, nonyl phenyl methacrylate, benzyl methacrylate, Examples include cyclopentenyl methacrylate, isobornyl methacrylate, etc. Polymethyl methacrylate in particular is easy to make into fine powder, the powder itself is spherical and transparent, has almost no odor, is safe, and is suitable for W/O makeup makeup. It has excellent emulsifying ability.

The average particle size of the polymethacrylic acid alkyl ester is 0.01 μm to 1 μm, preferably
It is 0.2 μm to 0.5 μm. Particle size is less than 0.01μm
If it exceeds 1 μm, it is difficult to obtain a stable emulsion.

The organic polymer fine powder may be produced by a conventionally known method. One production example is shown below using polymethyl methacrylate as an example.

A monomer of methyl methacrylate is subjected to emulsion polymerization in the presence of another monomer capable of emulsion copolymerization with this, such as methacrylic acid, to prepare an emulsion of polymer particles, and the polymer particles are recovered from this emulsion and dried, and then This is crushed and classified using a jet mill.

The amount of polymethacrylic acid alkyl ester is 0.1% to 10% by weight based on the total amount of the W/O emulsion composition.
Preferably it is 0.5% to 5% by weight. If the blending amount is less than 0.1% by weight, it may be difficult to stabilize the W/O makeup cosmetics;
If it exceeds 20%, the viscosity tends to increase, making it difficult to manufacture.

As the oil used in the W/O makeup cosmetic of the present invention, oils generally used in foods, paints, medicines, cosmetics, etc. can be used, and examples include paraffin oil, squalane, paraffin wax, ceresin, etc. hydrocarbons, natural animal and vegetable oils and fats such as olive oil, camellia oil, soybean oil, macadamia nut oil, castor oil, lanolin, carnauba wax, yellowtail wax, spermaceti wax, beeswax, jojoba oil, waxes, fatty acids with 10 to 35 carbon atoms, carbon atoms 10 or more
35 alcohol, synthesized esters having 16 or more carbon atoms, such as isopropyl myristate, isostearate diglyceride, 2-ethylhexanoate triglyceride, diisostearyl malate,
Myristyl myristate etc.

Any one kind or two or more kinds of these oils can be used, and the blending amount is generally 20% by weight to 80% by weight.

In addition to the above-mentioned essential ingredients of polymethacrylic acid alkyl ester, oil, and water, the W/O makeup cosmetic of the present invention may contain other surfactants, humectants, dyes, pigments, ultraviolet absorbers, fragrances, and medicinal properties. agent,
Preservatives, antioxidants, etc. can be added as appropriate.

[Examples] In order to further understand the present invention, Examples and Comparative Examples are listed below. All parts in the examples are expressed by weight.

Example 1 Emulsified lipstick Castor oil 50 (parts) Glyceryl diisostearate 10 Candelilla wax 8 Solid paraffin 10 Polymethyl methacrylate (average particle size
0.4μm) 4 Red No. 202 1 Red No. 202 0.5 Titanium oxide 1 Red iron oxide 1.5 Yellow iron oxide 1 Purified water 10 Glycerin 3 Manufacturing method Dissolve ~ uniformly at 80℃, add ~ and disperse, and then In addition, it emulsifies. While stirring, the mixture was filled into a molded container and cooled to obtain a lipstick.

Example 2 Cream foundation Isopropyl myristate 17 (parts) Squalane 10 Lanolin 7 Microcrystalline wax 3 Polymethyl methacrylate (average particle size
0.8 μm) 3 Butyl paraoxybenzoate 0.1 Kaolin 5 Talc 10 Titanium oxide 2 Red iron oxide 0.2 Yellow iron oxide 0.8 Fragrance 0.1 Purified water 36.7 Propylene glycol 5 Methyl paraoxybenzoate 0.1 Manufacturing method Dissolve ~ uniformly at 80℃, and ~ Add and disperse, then add and emulsify. The mixture was cooled while stirring to obtain a W/O cream foundation.

The W/O cream foundation produced in this example had good iron oxide dispersibility during production,
Furthermore, even when stored for 3 months under temperature conditions of 0°C, room temperature, and 37°C, the product remained stable without separation of oil and water.

It also had an excellent creamy feel and caused less makeup blemish.

Comparative Example 1 Comparative Example 1 was obtained in the same manner as in Example 1, except that polymethyl methacrylate in Example 1 was replaced with 0.4 parts of glycerin monooleate and 3.6 parts of sorbitol aqueous solution.

Comparative Example 2 Polymethyl methacrylate in Example 2
Comparative Example 2 was obtained in the same manner as in Example 1 except that POE (40 mol) was replaced with hydrogenated castor oil.

The emulsion type of the prepared sample was confirmed by electrical conductivity, and the emulsion particle size was observed using a microscope. The samples were stored at each temperature for 15 days, and their stability was examined based on the state of separation and changes in particle size.

In Comparative Example 1, water separated immediately after emulsification, and in Comparative Example 2, although it was emulsified, the iron oxide coagulated and the original color could not be obtained. The coagulation of the iron progressed further and eventually it all settled out.

In contrast, Examples 1 and 2 showed emulsion stability,
The W/O emulsion cosmetic had good dispersion stability and was stable for 3 months or more even when left at 37°C, room temperature, and 0°C.

Example 3 W/O solid foundation Macadamia nut oil 25 (parts) Vaseline 5 Ceresin 5 Polyethyl methacrylate (average particle size
0.3 μm) 4 Kaolin 15 Mica 20 Titanium oxide 8 Red iron oxide 1 Yellow iron oxide 3 Methyl paraoxybenzoate 0.1 Fragrance 0.1 Purified water 10.8 Prolene glycol 3 Manufacturing method Dissolve ~ uniformly at 80℃, add ~ and disperse Then add and emulsify. After adding the mixture while stirring, the mixture was poured into a container and cooled to obtain a W/O solid foundation.

Example 4 W/O emulsion blusher 2 Ethylhexanoic acid (part) triglyceride 20 Water-added lanolin 15 Microcrystalline wax 5 Propyl methacrylate (average particle size 3 μm) 3 Talc 20 Titanium oxide 5 Red iron oxide 3 Yellow iron oxide 1 Black Iron oxide 0.1 Red No. 201 1 Butyl paraoxybenzoate 0.1 Fragrance 0.1 Purified water 21.7 Glycerin 5 Manufacturing method Dissolve ~ uniformly at 80°C, add ~ to disperse, and further add and emulsify. After adding the mixture while stirring, the mixture was poured into a container and cooled to obtain a W/O emulsified blusher.

The W/O solid foundation of Example 3 and the W/O emulsion blusher of Example 4 have good stability even during long-term storage, and have an excellent feeling of use with a creamy feel and less makeup discoloration. /O It was an emulsified cosmetic.

[Effects of the Invention] The W/O makeup cosmetic according to the present invention has extremely good storage stability (emulsion stability and dispersion stability) over a wide temperature range compared to conventional products. It is also an emulsified composition with extremely high safety in terms of skin irritation.

Claims (1)

[Claims] 1. A water-in-oil makeup cosmetic comprising a polymethacrylic acid alkyl ester having an average particle size of 0.01 μm to 1 μm.