This application claims priority to Japanese Patent Application No. 2006-162028 filed on Jun. 12, 2006 and Japanese Patent Application No. 2007-11982 filed on Jan. 22, 2007, both of which are incorporated herein by reference.
The invention relates to gel compositions, and in particular, to an improved oil-gelling agent.
Oil-based products, such as a cleansing oil, have a good compatibility with makeup and an excellent cleansing effect. On the other hand, oil-based products have disadvantages such as dripping when they are applied to the skin and a sticky feeling in the hands owing to oil components contained therein.
Therefore, in the fields such as cosmetics, gelation of the oil components has been used as an effective method to improve the feeling in use and stability.
More specifically, various oil-based gel compositions have been developed to solve the above-mentioned problems. For example, techniques using, as an oil-gelling agent, 12-hydroxystearic acid (refer to Patent Literature 1), N-acylamino acid amide such as N-lauroyl-L-glutamic acid dibutylamide or N-acylamino acid amine salt such as Nα,Nω-dilauroyl-L-lysine stearylamine salt (refer to Patent Literature 2), polyether-modified silicones (refer to Patent Literature 3), and dextrin fatty acid ester such as dextrin palmitate (refer to Non-Patent Literature 4) have been suggested.
The conventional gelling agents could increase a viscosity of the system. However, such system has problems such as too low viscosity, a tendency of forming nonsmooth clumps, a poor temperature stability, a poor compatibility with surfactants to be blended and difficulty retaining transparency. Furthermore, such system also has not achieved a satisfactory feeling in use.
The present invention has been conceived in view of the above-described problems, and an object thereof is to provide a gel composition having a stable gelation ability and an excellent feeling in use.
The present inventors have diligently studied to achieve the above-described objects. As a result, the present inventors have found that a gel composition containing a block-type alkylene oxide derivative with a specific structure, oil components and water could achieve an excellent feeling in use, thus leading to completion of the present invention.
A gel composition of the present invention comprises:
(a) 0.1 to 60 mass % of a block-type alkylene oxide derivative,
(b) an oil, and
(c) 0.1 to 10 mass % of water;
wherein the ratio of the block-type alkylene oxide derivative to water is from 1:0.1 to 1:0.3; wherein a viscosity of the composition is 500 mPa·s or more (at 25° C.); and wherein the block-type alkylene oxide derivative is represented by the following formula (I):
R1O-[(AO)l(EO)m(AO)n]-R2 (I)
It is preferred that the gel composition does not comprise a conventional gelling agent.
It is also preferred that the gel composition is a transparent gel composition with an optical isotropy and 90% or more of visible light transmittance (per 1 cm optical path length) measured at 550 nm wavelength with a spectrophotometer.
By containing a block-type alkylene oxide derivative, an oil component and water, the present invention can easily form an oil-based gel with a high stability, which could not be achieved with conventional gelling agents owing to the reasons such as low viscosity or clumping. When the gel composition of the present invention is blended to products such as cosmetics, the products can be provided in usable forms without dripping during use because of the excellent gelation ability. Moreover, it can be thought that the products without dripping can prevent excess usage and lead to efficient use.
In addition, because of a high dispersibility of the oil component included in the gel composition, the products can achieve more excellent adaptabilities to the skin and more excellent feelings in use compared with conventional products. When applying the products to the skin, it is possible to rinse them off with water easily.
Because the gel composition according to the present invention has a stable transparency, which could not have been achieved in conventional products as they got cloudy with time, it has a good appearance and is easily blended with other compositions.
Hereinafter, preferred embodiments of the present invention will be described in detail.
A block-type alkylene oxide derivative included in the gel composition of the present invention is represented by the following formula (I):
R1O-[(AO)l(EO)m(AO)n]-R2 (I)
In the above-mentioned formula (I), AO represents an oxyalkylene group having 3 to 4 carbon atoms. The specific examples of oxyalkylene group include oxypropylene group, oxybutylene group, oxyisobutylene group, oxytrimethylene group, and oxytetramethylene group, and preferably oxypropylene group or oxybutylene group. EO represents an oxyethylene group.
The value m represents the average addition mole number of the oxyethylene group, and 1≦m≦70, preferably 5≦m≦55. The values l and n represent the average addition mole numbers of the oxyalkylene group having 3 to 4 carbon atoms, and 1≦l+n≦70, preferably 2≦l+n≦50. If the number of oxyalkylene groups having 3 to 4 carbon atoms or the number of the oxyethylene group is zero, a smooth feeling in the skin is deteriorated. If it exceeds 70, a sticky feeling tends to be caused after rinsing off.
R1 and R2 are hydrocarbon groups having 1 to 4 carbon atoms or hydrogen atoms. Examples of hydrocarbon groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl group, and preferably methyl group or ethyl group. If the hydrocarbon group has 5 or more carbon atoms, a hydrophilicity tends to decreases and a moist feeling is deteriorated.
R1 and R2 may be the same. Alternatively, in R1 and R2, a hydrocarbon group having 1 to 4 carbon atoms and a hydrogen atom may be used together, or different hydrocarbon groups having 1 to 4 carbon atoms may be used together. The same or different hydrocarbon groups having 1 to 4 carbon atoms are more preferably used. If hydrogen atoms are used in both R1 and R2, or a hydrocarbon and a hydrogen atom are used together in R1 and R2, the composition causes a more sticky feeling after rinsing off as compared with using the identical or different hydrocarbon groups having 1 to 4 carbon atoms in R1 and R2.
The specific examples of a block-type alkylene oxide derivative used in the present invention include POE(9)POP(2)dimethyl ether, POE(14)POP(7)dimethyl ether, POE(10)POP(10)dimethyl ether, POE(6)POP(14)dimethyl ether, POE(15)POP(5)dimethyl ether, POE(25)POP(25)dimethyl ether, POE(7)POP(12)dimethyl ether, POE(22)POP(40)dimethyl ether, POE(35)POP(40)dimethyl ether, POE(50)POP(40)dimethyl ether, POE(55)POP(30)dimethyl ether, POE(30)POP(34)dimethyl ether, POE(25)POP(30)dimethyl ether, POE(27)POP(14)dimethyl ether, POE(55)POP(28)dimethyl ether, POE(36)POP(41)dimethyl ether, POE(7)POP(12)dimethyl ether, POE(17)POP(4)dimethyl ether, POE(9)POB(2)dimethyl ether, POE(14)POB(7)dimethyl ether, POE(10)POP(10)dimethyl ether, POE(10)POP(10)dipropyl ether, POE(10)POP(10)dibutyl ether, POE(52)POB(32)dimethyl ether, POE(34)POB(14)dimethyl ether, POE(3 5)POB(32)dimethyl ether, POE(23)POB(32)dimethyl ether, POE(45)POB(28)dimethyl ether, POE(35)POP(30)glycol, and POE(3 5)POB(32)glycol.
The abbreviations POE, POP, and POB, which are used above, are for polyoxyethylene, polyoxypropylene, and polyoxybutylene, respectively. Hereinafter these abbreviations may be used.
The amount of a block-type alkylene oxide derivative blended in the gel composition of the present invention is preferably 0.1 to 60 mass %, more preferably 3 to 30 mass %. If the blending amount is less than 0.1 mass %, a satisfactory effect may not be achieved by blending. If the blending amount exceeds 60 mass %, a sticky feeling may be caused after rinsing off.
The block-type alkylene oxide derivative used in the present invention can be prepared by known methods. For example, after addition polymerization of ethylene oxide and an alkylene oxide having 3 to 4 carbon atoms to a compound with a hydroxyl group, an etherification with an alkyl halide is carried out in the presence of an alkaline catalyst to give the block-type alkylene oxide derivative.
The gel composition of the present invention includes an oil component which is generally used in cosmetics, quasi-drugs and the like, such as hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, and silicone oils. One or more oil components which can dissolve the alkylene oxide derivative may be used.
Examples of the hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, and microcrystalline wax.
Examples of the higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecylenic acid, tallic acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid(EPA), and docosahexanoic acid (DHA).
Examples for the higher alcohols include linear alcohols (e.g. lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and cetostearyl alcohols); and branched-chain alcohols (e.g. monostearylglycerin ether (batyl alcohol), 2-decyltetradecinol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, and octyldodecanol).
Examples of the synthetic ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerol di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, glycerol tri-2-ethylhexanoate, glycerol trioctanoate, glycerol triisopalmitate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glycerol trimyristate, glycerol tri-2-heptylundecanoate, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, 2-octyldodecyl N-lauroyl-L-glutamate, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate.
Examples of the silicone oils include chain polysiloxanes (e.g. dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane); cyclic polysiloxanes (e.g. octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane), silicone resins having a three dimensional network structure, silicone rubbers, various modified polysiloxans (such as amino-modified polysiloxanes, polyether modified polysiloxanes, alkyl-modified polysiloxanes, fluorine-modified polysiloxanes), and acrylic silicones.
The amount of the oil component blended to the gel composition of the present invention is not restricted in particular, and in general, preferably 20 to 90 mass % with respect to the amount of the composition, and more preferably 40 to 80 mass %. If the blending amount of the oil component is less than 20 mass %, gel formation and cleansing effect may be insufficient. If it exceeds 90 mass %, a sticky feeling may be caused after use.
The water included in the gel composition of the present invention is not restricted in particular, and if it is to be specified, the examples of water include purified water, ion-exchanged water, and tap water.
The blending amount of water depends on the blending amount of the alkylene oxide derivative, however, preferably 0.1 to 10 mass % with respect to the amount of the composition, more preferably 0.5 to 8 mass %.
If the blending amount of water is less than 0.1 mass %, the composition may not become a gel. If it exceeds 10 mass %, water may be separated to give a clouded or hard composition or to lower the viscosity, which is practically unpreferable.
A block-type alkylene oxide derivative, which is an amphipathic substance, forms aggregates in the composition of the present invention including an oil and water. If the block-type alkylene oxide derivative and water meet specific blending amounts, the aggregates exhibit a gel-forming ability and turn the system of the composition to a gel. Thus, the gel composition of the present invention can become a gel without using other gelling agents as long as the above-mentioned essential components are included.
In the gel composition of the present invention, it is preferred that the continuous phase is an oil phase.
The word “gel” in the present invention means the state having a thixotropic property and an apparent viscosity of 500 mPa·s or more at the shear rate of 1 s−1 at 25° C. with a cone-plate type rheometer. Hence, if the blending amounts of the block-type alkylene oxide derivative and water are within the above-mentioned ranges, and the viscosity of the composition is 500 mPa·s, the gel composition of the present invention can keep a preferable gelled state without dripping during use. If the viscosity of the composition is less than 500 mPa·s, unpreferably, the composition does not achieve a satisfactory dripping prevention effect.
It is preferred that the gel composition of the present invention is a gel with an optical isotropy and a high transparency of which a visible light transmittance (per 1 cm optical path length) at 550 nm wavelength measured with a spectrophotometer is 90% or more. A composition with an optical isotropy has higher thixotropic property of gel and more excellent feeling in use than a composition without an optical isotropy. When the gel composition of the present invention having a high transparency is blended to a product such as cosmetics, a visual impression of the product is good, which is practically preferable.
Further to the above-mentioned essential components, the components which are generally used in cosmetics or quasi-drugs, such as moisturizers, powders, surfactants, natural polymers, synthetic polymers, UV absorbers, saccharides, antioxidants, various extracts, and perfumes can be blended in the gel composition of the present invention. The gel composition can be produced in a conventional manner.
The present invention will now be described in more detail with reference to the embodiments, however, these embodiments are not intended to limit the scope of the invention.
The evaluation test method and criteria used in the embodiments are described.
1. A foundation forming a strong coating prepared according to the following formulation was applied to the face over and over.
2. 2 hours after applying the foundation, a sample prepared with components in the following Table 1 was applied and spread on the part where the foundation was applied to remove the makeup.
3. The sample was rinsed off with water.
The states of gel formation (thixotropic properties) after preparing the respective samples were observed.
The apparent viscosities at the shear rate of 1 s−1 were measured with a cone-plate rheometer. The cone with 50 mm diameter and 2° angle was used for measurement, and the measurement temperature was 25° C. The evaluation criteria are as follows.
O: Gel having a thixotropic property is formed.
(The viscosity is 500 mPa·s or more)
X: Gel is not formed.
Drippings of the respective samples were evaluated in Step 2 of the above-mentioned test method. The evaluation criteria are as follows.
{circle around (o)}: Among 10 Panelists, 8 Panelists or more acknowledged that dripping is not sensed during use.
O: Among 10 Panelists, 6 to 7 Panelists acknowledged that dripping is not sensed during use.
Δ: Among 10 Panelists, 3 to 5 Panelists acknowledged that dripping is not sensed during use.
X: Among 10 Panelists, less than 3 Panelists acknowledged that dripping is not sensed during use.
The makeup cleansing effects of the respective samples were evaluated in Step 2 of the above-mentioned test method. The evaluation criteria are as follows.
{circle around (O)}: Among 10 Panelists, 8 Panelists or more acknowledged an excellent makeup cleansing effect.
O: Among 10 Panelists, 6 to 7 Panelists acknowledged an excellent makeup cleansing effect.
Δ: Among 10 Panelists, 3 to 5 Panelists acknowledged an excellent makeup cleansing effect.
X: Among 10 Panelists, less than 3 Panelists acknowledged an excellent makeup cleansing effect.
The presences of a smooth feeling in the skin after rinsing off the samples were evaluated in Step 3 of the above-mentioned test method. The evaluation criteria are as follows.
{circle around (o)}: Among 10 Panelists, 8 Panelists or more acknowledged the presence of a smooth feeling in the skin after rinsing off.
O: Among 10 Panelists, 6 to 7 Panelists acknowledged the presence of a smooth feeling in the skin after rinsing off.
Δ: Among 10 Panelists, 3 to 5 Panelists acknowledged the presence of a smooth feeling in the skin after rinsing off.
X: Among 10 Panelists, less than 3 Panelists acknowledged the presence of a smooth feeling in the skin after rinsing off.
The actual use tests of the respective samples, which were prepared with the components described in the following Table 1, were conducted by 10 professional panelists with the above-mentioned test method. Gel forming abilities of the respective samples were evaluated with the criteria of the above-mentioned Evaluation Criteria (1), and the feelings in use of the compositions were tested by the panelists with the criteria of the above-mentioned Evaluation Criteria (2) to (4). The results are shown in Table 1.
In Test Examples 1 and 2 in which a block-type alkylene oxide derivative and an appropriate amount of water were blended, the compositions became gels and were excellent in every evaluation.
In Test Example 3 in which a block-type alkylene oxide derivative was not blended, on the other hand, the composition did not become a gel or did not have a dripping prevention effect as well as a satisfactory makeup cleansing effect and a satisfactory smooth feeling. In Test Example 4 in which a polyether-modified silicone being an oil-gelling agent was blended instead of a block-type alkylene oxide derivative, the composition became a gel, but was inferior in feeling in use as a makeup remover to the compositions of Test Examples 1 and 2 according to the present invention. In Test Example 5 in which polyethylene glycol diisostearate being an emulsifier was used, the composition did not become a gel and did not have a dripping prevention effect.
In Test Example 6 in which water was not blended, a good makeup cleansing effect and a good feeling in use could be achieved, however, the composition did not become a gel and did not have a dripping prevention effect.
As described above, it became apparent that blending (a) a block-type alkylene oxide derivative, (b) an oil component, and (c) water could form a gel with an excellent dripping prevention effect and could give the gel composition with an excellent feeling in use.
Next, preferable blending amounts of a block-type alkylene oxide derivative with a specific structure and water to form a gel were studied.
In the composition in Table 2, the value x was changed while keeping x+y=100 g and the value z was increased from zero. The oil in Table 2 is a mixture of 73.2 parts of liquid paraffin, 2.4 parts of methylphenylpolysiloxane, and 24.4 parts of cetyl 2-ethylhexanoate. Depending on the blending amounts of the respective x, y and x components, the phase of composition varied from Phases I to IV in
In the regions of Phase I and Phase II in
Then, as samples of the respective phases in
As shown in Table 3, Test Example 7-1 from Phase I had an excellent gel forming ability, an extremely excellent dripping prevention effect, and a good feeling in use.
Test Example 7-2 from Phase II formed a gel and had an excellent dripping prevention effect. In terms of a feeling in use, however, it had slightly less smooth feeling in the skin after rinsing off than Test Example 7-1.
In Test Example 7-3 from Phase III, a gel formation could not be observed and thus a dripping prevention effect could not be achieved at all. It also had worse feeling in use than the other Test Examples.
According to the above-mentioned results, it was considered that the composition including (a) a block-type alkylene oxide derivative, (b) an oil component, and (c) water had an excellent dripping prevention effect if its physical property was correspondent to that of the composition within the regions of Phase I and Phase II in
Subsequently, to comprehend the properties of the gel compositions included in Phase I and Phase II in
A transparency of composition was expressed in a visible light transmittance (per 1 cm optical path length) measured at 550 nm wavelength with a spectrophotometer (Hitachi U3501 spectrophotometer).
An optical property was evaluated by studying the presence of an optical isotropy in the composition in a structural observation with a polarizing microscope. The results are shown in Table 4.
The gel composition of Test Example 7-1 within Phase I in
Thus, it was confirmed that, in the gel composition of the present invention, the presence of an optical isotropy further improved a smooth feeling in the skin after rinsing off.
According to the above-mentioned results, it became apparent that, in the gel composition of the present invention, the blending amount of a block-type alkylene oxide derivative was 0.1 to 60 mass % with respect to the composition, the blending amount of water was 0.1 to 10 mass % with respect to the composition, and the viscosity was 500 mPa·s or more. Additionally, it is preferred that the gel composition has an optical isotropy and is a transparent gel composition with 90% or more of light transmittance.
Formulation examples of the gel composition of the present invention will hereinafter be described. However, the scope of the present invention is not limited by these examples. Every obtained composition became a gel effectively, could prevent dripping when taking it up on the palm, and had an excellent feeling in use.
Camellia oil
Number | Date | Country | Kind |
---|---|---|---|
2006-162028 | Jun 2006 | JP | national |
2007-011982 | Jan 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2007/061420 | 6/6/2007 | WO | 00 | 12/10/2008 |