KR102587152B1 - Water-in-oil type emulsion - Google Patents

Abstract

The present invention relates to an emulsion that can improve the stability of the formulation by preventing coalescence of the internal phase by forming an additional film through the coacervation principle when emulsified particles are damaged. Specifically, it relates to an emulsion that can improve the stability of the formulation; specifically, an aqueous phase containing an anionic water-soluble polymer compound; and an oil phase containing an amine group-containing compound. It relates to a water-in-oil emulsion comprising a.

Description

Water-in-oil type emulsion}

The present invention relates to a water-in-oil emulsion with improved formulation stability by preventing coalescence of emulsified particles by forming an additional film through the coacervation principle when the emulsified particles are damaged.

An emulsion is one in which oil droplets are dispersed in water (oil-in-water type) or water droplets are dispersed in oil (water-in-oil type). These emulsions are thermodynamically very unstable, ultimately leading to flocculation and sedimentation. , it has the property of phase separation through various paths such as creaming, Ostwald ripening, and coalescence.

In general, in the case of oil-in-water emulsions, the emulsion film is strengthened with surfactants, fatty alcohol, and acid to prevent coalescence of emulsified particles, and creaming and aggregation are prevented by improving the viscosity of the external water phase.

However, in the case of a water-in-oil emulsion, excessive improvement in the viscosity of the oil phase causes stickiness during use and worsens the feeling of use, so there is a limit to the mixing of the thickener, so it is not possible to improve the viscosity of the oil phase beyond a certain level. difficult. Accordingly, it is difficult to prevent cohesion, adhesion, creaming, etc. between emulsified particles, and the viscosity and hardness of the formulation decreases over time, and the formulation has the disadvantage of phase separation. In particular, this phenomenon is accelerated in formulations with low viscosity. there is.

Accordingly, the present inventors attempted to improve the formulation stability of water-in-oil emulsion by forming an additional film through the coacervation principle to prevent coalescence of emulsified particles.

A prior document aimed at improving the formulation stability of water-in-oil emulsion is Korean Patent Publication No. 10-2015-0102727.

Republic of Korea Patent Publication No. 10-2015-0102727 (2015.09.07)

The present invention was developed to solve the above problems. When the emulsified particles are damaged, an additional film is formed through the coacervation principle to prevent the coalescence of the emulsified particles, thereby providing a water-in-oil emulsion with improved formulation stability. do.

The present invention provides an aqueous phase containing an anionic water-soluble polymer compound; and an oil phase containing an amine group-containing compound. It relates to a water-in-oil emulsion comprising a.

The water-in-oil emulsion according to the present invention increases the viscosity of the inner phase by adding an anionic water-soluble polymer compound to the water phase, which is the inner phase, and simultaneously charges it with a negative charge, thereby allowing effective interaction with the amine group-containing compound added to the outer phase. Accordingly, when the emulsion film is damaged, an additional film is formed through coacervation to prevent the coalescence of emulsified particles, thereby effectively improving the formulation stability of the water-in-oil emulsion.

Figure 1 is a photograph comparing the formulation stability of water-in-oil emulsions prepared according to Example 1 and Comparative Examples 1 to 3 of the present invention after leaving them for 24 hours, A-Comparative Example 1, B-Comparative Example 2, C- Comparative Example 3, and D-Example 1.

Hereinafter, the water-in-oil emulsion according to the present invention will be described in detail with reference to the attached drawings. The drawings introduced below are provided as examples so that the idea of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Additionally, like reference numerals refer to like elements throughout the specification.

In general, in the case of oil-in-water emulsions, the emulsion film is strengthened with surfactants, fatty alcohol, and acid to prevent coalescence of emulsified particles, and creaming and aggregation are prevented by improving the viscosity of the external water phase.

However, in the case of a water-in-oil emulsion, excessive improvement in the viscosity of the oil phase causes stickiness during use and worsens the feeling of use, so there is a limit to the mixing of the thickener, so it is not possible to improve the viscosity of the oil phase beyond a certain level. difficult. Accordingly, it is difficult to prevent cohesion, adhesion, creaming, etc. between emulsified particles, and the viscosity and hardness of the formulation decreases over time, and the formulation has the disadvantage of phase separation. In particular, this phenomenon is accelerated in formulations with low viscosity. there is.

Accordingly, the present inventors attempted to improve the formulation stability of water-in-oil emulsion by forming an additional film through the coacervation principle to prevent coalescence of emulsified particles.

In detail, the water-in-oil emulsion according to the present invention includes an aqueous phase containing an anionic water-soluble polymer compound; and an oil phase containing an amine group-containing compound.

In this way, by adding an anionic water-soluble polymer compound to the aqueous phase, which is the inner phase, the viscosity of the inner phase is increased and at the same time, it is charged with a negative charge, thereby allowing effective interaction with the amine group-containing compound added to the outer phase, thereby forming an emulsion film. When damaged, an additional film is formed through coacervation to prevent coalescence of emulsified particles, thereby effectively improving the formulation stability of water-in-oil emulsion.

In the present invention, the anionic water-soluble polymer compound has a functional group that can carry a negative charge, can improve the viscosity of the inner phase, and can be used without particular limitation as long as it is a material that dissolves well in the inner phase. Specifically, the anionic water-soluble polymer compound may be a polymer containing one or more functional groups selected from carboxylic acid groups, sulfonic acid groups, sulfuric acid ester groups, phosphoric acid ester groups, and salts thereof. By containing such anionic functional group, it can be well dissolved in the aqueous phase, which is the internal phase.

More specifically, for example, the anionic water-soluble polymer compound may be any one or two or more selected from acrylic acid-based polymer compounds, polysaccharide polymer compounds, and sulfonic acid-based polymer compounds. Using such a compound not only dissolves well in the water phase, but also improves the viscosity of the internal phase, thereby further improving the stability of the emulsified particles.

More specifically, for example, the acrylic acid-based polymer compound includes an acrylic acid-based derivative polymer compound and may be a homopolymer or copolymer of acrylic acid-based monomer. As a non-limiting example, the acrylic acid-based polymer compound includes polyacrylic acid, polymethacrylic acid, etc. Crylic acid, polymethyl methacrylic acid, methyl methacrylate-acrylic acid copolymer, vinylpyrrolidone-acrylic acid copolymer, hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer, acrylate/C10-30 alkyl It may be any one or two or more selected from acrylate crosspolymers and salts thereof. The polysaccharide polymer compound may be any one or two or more selected from alginic acid, pectin, polygalacturonic acid, and salts thereof; The sulfonic acid-based polymer compound may be polystyrene sulfonic acid, etc., but is not necessarily limited thereto. Any polymer compound that has an anionic functional group and is soluble in an aqueous phase can be used without particular limitation.

By using such anionic water-soluble polymer compound, the viscosity of the inner phase can be improved, and as the viscosity of the inner phase is improved, the stability of the emulsified particles can also be improved. In addition, by using an anionic water-soluble polymer that can carry a negative charge, as described above, it can effectively interact with the amine group-containing compound added to the external wound to form an additional film when the emulsion film is damaged, thereby improving the stability of the emulsion particles. It can be improved further.

Particularly preferably, the anionic water-soluble polymer compound according to an example of the present invention may contain 10 mol% or more of hydrophobic groups out of the number of moles of repeating units of the anionic water-soluble polymer compound. In this way, by having a hydrophobic group along with an anionic functional group, it can also perform the role of a surfactant, thereby further improving the stability of the water-in-oil emulsion. At this time, the upper limit of the mole% of the hydrophobic group is not particularly limited, but may be 100 mol% or less, and preferably 80 mol% or less.

More specifically, the hydrophobic group may be any one or two or more selected from the group consisting of a linear or branched alkyl group having 8 to 30 carbon atoms, a halogenated alkyl group, an alkenyl group, an alkynyl group, or an aryl group having 6 to 30 carbon atoms, and preferably has 6 to 30 carbon atoms. It may be 8 to 30 linear or branched alkyl groups.

In the present invention, the amine group-containing compound forms an additional film when the emulsion particle is damaged through interaction with the anionic water-soluble polymer compound in the internal phase when the emulsion film is damaged, thereby providing the water-in-oil emulsion with improved formulation stability, and is well suited to the oil phase. Any substance that is soluble and can carry a positive charge can be used without particular limitations. At this time, the amine group comprehensively refers to primary amine, secondary amine, or tertiary amine, and the amine group-containing compound may contain any one or two or more selected from -N=, -NH-, and -NH _2. there is.

Specifically, the amine group-containing compound may be any one or two or more selected from aliphatic amine compounds, aromatic amine compounds, and amine group-containing silicon-based compounds. By using such an amine group-containing compound, as described above, it can effectively interact with the anionic water-soluble polymer compound added to the internal phase to form an additional film when the emulsion film is damaged, thereby further improving the stability of the emulsion particles. .

More specifically, for example, aliphatic amine compounds include alkylamines containing a linear or branched alkyl group having 6 to 30 carbon atoms, alkanolamines containing a linear or branched alkanol group having 6 to 30 carbon atoms, and satisfying the following formula (1): It may be any one or two or more compounds selected from the following compounds; The aromatic amine compound may be any one or two or more selected from aniline, o-toluidine, 2,4,6-trimethylaniline, anisidine, and N-methylaniline, and the amine group-containing dimethicone-based compound is amodimethicone, It may be any one or two or more selected from bisamodimethicone and aminopropyl dimethicone, but is not necessarily limited thereto. Any substance that contains an amine group and is easily soluble in the oil phase can be used without particular limitation.

[Formula 1]

(In Formula 1, R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₂ and R ₃ are independently linear or branched alkyl groups having 10 to 30 carbon atoms.)

In addition, the water-in-oil emulsion according to an example of the present invention contains an anionic water-soluble polymer compound added to the water phase, which is the inner phase, and an amine group-containing compound added to the oil phase, the outer phase, to effectively form an additional film by coacervation when the emulsion film is damaged. It is desirable to appropriately adjust the addition amount.

Specifically, the anionic water-soluble polymer compound is added at 0.01 to 1% by weight of the total weight of the emulsion; The amine group-containing compound may be added in an amount of 0.1 to 10% by weight based on the total weight of the emulsion. If too little anionic water-soluble polymer compound is added, the area available for coacervation decreases and the interfacial film cannot be completely covered, making it difficult to form an additional film when the emulsion film is damaged. Even if the amount of the anionic water-soluble polymer compound is sufficient, if the amount of the amine group-containing compound is small, the effect of interaction with the anionic water-soluble polymer compound may be reduced, so no additional film is created, or the effect may be minimal.

Additionally, the oil phase according to an example of the present invention may include oil, and the oil may be used without particular limitation as long as it is commonly used in the art. For example, when used for cosmetic purposes, the oil may be any one or two or more selected from silicone-based oil, hydrocarbon-based oil, and ester-based oil. More specifically, silicone oils include cyclopentasiloxane, cyclohexasiloxane, cycloheptasiloxane, cyclomethicone, cyclophenylmethicone, cyclotetrasiloxane, cyclotrisiloxane, dimethicone, capryl dimethicone, caprylyl trimethicone, Caprylyl methicone, cetearyl methicone, hexadecyl methicone, hexyl methicone, lauryl methicone, myrithyl methicone, phenyl methicone, stearyl methicone, scalearyl dimethicone, trifluoropropyl methicone, Examples include, but are not limited to, cetyldimethicone, dimethylpolysiloxane, methylphenylpolysiloxane, decamethylcyclopentasiloxane, methylctrimethicone, or phenyltrimethicone. Hydrocarbon oils include paraffinic hydrocarbon oils, olefinic hydrocarbon oils, aliphatic, cycloaliphatic, or aromatic hydrocarbon oils, and non-limiting examples include n-octane, n-nonane, n-decane, n-undecane, and n- Dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, vaseline, paraffin, isoparaffin, ceresin, squalane, squalene, polybutene, poly Examples include, but are not limited to, decene or polyisoprene. Ester oils include ascorbyl palmitate, ascorbillinoleate, ascorbyl stearate, distearyl malate, benzyl benzoate, benzyl laurate, butylene glycol dicaprylate/dicaprate, butylene glycol diisononanoate, Butylene glycol laurate, butylene glycol stearate, butyl isostearate, cetearyl isononanoate, cetearyl nonanoate, cetyl caprylate, cetyl ethyl hexanoate, cetyl isononanoate, ethyl Hexyl caprylate/caprate, ethylhexyl isononanoate, ethylhexyl isostearate, ethylhexyl laurate, hexyl laurate, octyldodecyl isostearate, isopropyl isostearate, isostearyl Sononanoate, isostearyl isostearate, isocetyl ethylhexanoate, neopentyl glycol dicaprate, neopentyl glycol diethylhexanoate, neopentyl glycol diisononanoate, neopentyl glycol diisostearate, Pentaerythrityl stearate, pentaerythrityl tetraethylhexanoate, triethylhexanoin, etc. are included, but are not limited thereto.

From another perspective, the oil according to an example of the present invention may be natural oil, synthetic oil, or a mixture thereof. More specifically, the natural oil is any one or two or more selected from vegetable oil, animal oil, and mineral oil. You can use it. As a non-limiting example, vegetable oils include olive oil, almond oil, palm oil, malt oil, castor oil, avocado oil, corn oil, soybean oil, rapeseed oil, camellia oil, cottonseed oil, moonshine colostrum, jojoba oil, palm oil, and coconut oil. , rosehip oil, or macadaima oil, etc., animal oils may be egg yolk oil, shark liver oil, emu oil, or mink oil, and mineral oils may be paraffin, petrolatum, or ceresin, but are not limited thereto. Synthetic oil may be silicone-based oil, hydrocarbon-based oil, or ester-based oil, and each specific ingredient is the same as the silicone-based oil, hydrocarbon-based oil, and ester-based oil described above, excluding natural oil, and detailed description is omitted.

Additionally, the water phase of the water-in-oil emulsion according to an example of the present invention may further include a neutralizing agent. By adding a neutralizing agent to the water phase, the anionic water-soluble polymer compound can be more effectively negatively charged, and thus coacervation can occur effectively, further improving the stability of the emulsified particles.

Specifically, the neutralizing agent may be a basic compound, non-limiting examples of which may be potassium hydroxide, sodium hydroxide, triethanolamine, or tromethamine. However, when used as a cosmetic, it is preferable to use tromethamine, which is non-irritating and has high safety. .

The amount added is not particularly limited, but may be added at 0.001 to 2% by weight of the total weight of the emulsion, preferably at 0.005 to 1% by weight, and more preferably at 0.01 to 0.1% by weight. It is good because it allows for more effective negative charge while not compromising the physical properties of the emulsion.

In addition, the water-in-oil emulsion according to an example of the present invention contains surfactants, polyols, and emollients commonly used in the art depending on the purpose of the water-in-oil emulsion, to the extent that the physical properties of the emulsion do not deteriorate and phase inversion does not occur. , sunscreen, antioxidants, stabilizers, preservatives, disinfectants, colorants, fragrances, or pearl agents may be further included.

In one example of the present invention, the surfactant is for stably producing a water-in-oil emulsion formulation, and any surfactant commonly used for producing a water-in-oil emulsion may be used without particular limitation, and may be a lipophilic nonionic surfactant or a cationic surfactant. A surfactant may be used. As a non-limiting example, glyceryl stearate, sorbitan sesquioleate, sorbitan olivate, sorbitan stearate, polyethylene glycol-10 dimethicone, lauryl polyethylene glycol-9 polydimethylsiloxyethyl dimethicone, It may be any one or two or more selected from Lauyl polyethylene glycol-10 tris(trimethylsiloxy)silylethyl dimethicone, stearic acid, distearyl dimonium chloride, and cetyl polyethylene glycol/PPG-10/1 dimethicone. . The amount of surfactant added is not particularly limited, but may be 0.1 to 10% by weight of the total weight of the emulsion. In the above range, formulation stability is excellent.

In one example of the present invention, polyol is used to improve moisturizing power when used as a cosmetic, and is not particularly limited as long as it is commonly used in the industry, and examples include glycerin, propylene glycol, butylene glycol, glycerin, and erythritol. , xylitol, maltitol glycerin, sorbitol, polyglycerin, polyethylene glycol, pentanediol, and isoprene glycol, or one or more of them may be used, but are not limited thereto. The amount of polyol added is not particularly limited, but may be 0.1 to 20% by weight of the total weight of the emulsion. The moisturizing effect is excellent in the above range.

Such water-in-oil emulsions can be manufactured into various formulations such as lotions, creams, facial cleansing cosmetics, packs, foundations, makeup bases, etc. depending on the purpose, and can be formulated according to conventional manufacturing methods.

The water-in-oil emulsion according to the present invention will be described in more detail through examples below. However, the following examples are only a reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms. Additionally, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. The terminology used in the description herein is merely to effectively describe particular embodiments and is not intended to limit the invention. Additionally, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to also include the plural forms, unless the context clearly dictates otherwise. Additionally, the unit of additives not specifically described in the specification may be weight percent.

[Examples 1 to 5]

With the composition shown in Table 1 below, a water-in-oil emulsion was prepared through a conventional method, and each component was added in weight percent based on the total weight of the emulsion. More specifically, after mixing the aqueous phase and the oil phase, the aqueous phase was added to the oil phase and mixed.

At this time, Compounds A and B are amine group-containing compounds, Compound A is hexyldecyl myristoyl methylaminopropionate, and Compound B is amodimethicone,

Compounds C, D, E, and F were anionic polymer compounds, where compound C was an acrylate/C10-C30 alkyl acrylate crosspolymer, compound D was polyacrylic acid, compound E was alginic acid, and compound F was polystyrene sulfonic acid. Lauyl polyethylene glycol-10 tris(trimethylsiloxy)silylethyldimethicone was used as the surfactant.

In addition, an experiment was conducted to accelerate the decline in stability by using a small amount of surfactant compared to the amount of surfactant commonly used, and the results are shown in Table 3 and Figure 1.

Example 1 Example 2 Example 3 Example 4 Example 5 squalane 17 17 17 17 17 Compound A 4 0 4 4 4 Compound B 0 4 0 0 0 Surfactants One One One One One water To 100 To 100 To 100 To 100 To 100 Compound C 0.1 0.1 0 0 0 Compound D 0 0 0.1 0 0 Compound E 0 0 0 0.1 0 Compound F 0 0 0 0 0.1 Tromethamine 0.05 0.05 0.05 0.05 0.05

[Comparative Examples 1 to 3]

An emulsion was prepared in the same manner as in Example 1, except that a water-in-oil emulsion was prepared with the composition shown in Table 2, and each component was added in weight percent based on the total weight of the emulsion. In addition, the stability evaluation results of the prepared water-in-oil emulsion are shown in Table 3 and Figure 1.

Comparative Example 1 Comparative Example 2 Comparative Example 3 squalane 21 17 17 Compound A 0 4 0 Compound B 0 0 0 Surfactants One One One water To 100 To 100 To 100 Compound C 0 0 0.1 Compound D 0 0 0 Compound E 0 0 0 Compound F 0 0 0 Tromethamine 0.05 0.05 0.05

Formulation stability electrical conductivity 24 hours 48 hours Example 1 O
(Good) O
(Good) 0 Example 2 O
(Good) O
(Good) 0 Example 3 O
(Good) △
(Partial merger) 0 Example 4 O
(Good) △
(Partial merger) 0 Example 5 O
(Good) △
(Partial merger) 0 Comparative Example 1 X
(previous injury) - >0 Comparative Example 2 X
(previous injury) - >0 Comparative Example 3 X
(previous injury) - >0

As can be seen from Table 3 and Figure 1, acrylate/C10-C30 alkyl acrylate crosspolymer, an anionic water-soluble polymer compound, was added to the inner phase, and hexyldecyl myristoyl methyl, an amine group-containing compound, was added to the outer phase. In Examples 1 to 5 in which aminopropionate was added, it was confirmed that the phases did not separate even after 24 hours and that the water-in-oil formulation was stably maintained.

In particular, in the case of Examples 1 and 2, the anionic polymer compound has a hydrophobic group along with an anionic functional group and acts as a surfactant, so in the case of Examples 3 and 5, an anionic polymer compound without a hydrophobic group was added. It was confirmed that the stability of the emulsified particles was further improved.

On the other hand, in the case of Comparative Example 1 in which neither of the two compounds was added, it was confirmed that the water phase and the oil phase were completely separated, and in the case of Comparative Examples 2 and 3 in which only one of the two compounds was added, the layers were separated and the phases were separated. As it was reversed and became a water-based formulation, it was confirmed that its stability was greatly reduced.

Accordingly, it can be confirmed that the stability of the formulation can be greatly improved by using the two compounds together compared to using anionic water-soluble polymer compounds or amine group-containing compounds separately, and this is due to the coacervation principle when emulsion particles are damaged. This is because an additional film is formed and the coalescence of the internal phase is prevented, thereby improving the phase stability of the emulsified particles.

As described above, the present invention has been described with specific details, limited embodiments, and drawings, but these are provided only to facilitate a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention Anyone skilled in the art can make various modifications and variations from this description.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and the scope of the patent claims described below as well as all modifications that are equivalent or equivalent to the scope of this patent claim shall fall within the scope of the spirit of the present invention. .

Claims (8)

An aqueous phase containing an anionic water-soluble polymer compound; and an oil phase containing an amine group-containing compound,
The anionic water-soluble polymer compound is an acrylate/C10-C30 alkyl acrylate crosspolymer,
The amine group-containing compound is a water-in-oil emulsion that is an alkylamine or amine group-containing dimethicone-based compound containing a linear or branched alkyl group having 6 to 30 carbon atoms.
delete delete According to clause 1,
The anionic water-soluble polymer compound is a water-in-oil emulsion containing 10 mol% or more of hydrophobic groups based on the number of moles of repeating units of the anionic water-soluble polymer compound.
According to clause 4,
A water-in-oil emulsion wherein the hydrophobic group is any one or two or more selected from a linear or branched alkyl group having 8 to 30 carbon atoms, a halogenated alkyl group, an alkenyl group, an alkynyl group, or an aryl group having 6 to 30 carbon atoms.
delete According to clause 1,
The anionic water-soluble polymer compound is added in an amount of 0.01 to 1% by weight based on the total weight of the emulsion; A water-in-oil type emulsion in which the amine group-containing compound is added in an amount of 0.1 to 10% by weight based on the total weight of the emulsion.
According to clause 1,
The water phase is a water-in-oil emulsion further comprising a neutralizing agent.