JP2010270299A - Oil gel comprising reverse worm-like micelle essentially comprising lecithin and urea - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil-gelling agent which forms a reverse worm-like micelle having high safety to a living body and environment, a desirable use feeling, and good gelling ability, and to provide a thickened gel composition using the oil-gelling agent. <P>SOLUTION: Lecithin/urea acts as an oil-gelling agent which forms a reverse worm-like micelle of various oils. A thickened gel composition having a reverse worm-like micelle structure can be obtained by using a three-component mixed system of lecithin/urea/an oil. Thus, there is provided a good oil-gelling agent which is very safe to a human body and environment, has long-term stability, and has performance required for an oil-gelling agent. There is also provided a thickened gel composition which contains the oil-gelling agent and an oil component and has formed a reverse worm-like micelle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil gelling agent for thickening or gelling oil such as animal and vegetable oils, mineral oils, hydrocarbons, fatty acid esters, and the like, and a thickening gel-like composition containing the oil and oil gelling agent Related to things.

  Oil gelling agents that thicken or gelate oils such as animal and vegetable oils, mineral oils, hydrocarbons, and fatty acid esters are used in various fields such as cosmetics, pharmaceuticals, foods, paints, inks, and lubricating oils. Widely used in The performance generally required for the oil gelling agent includes that the target oil can be gelled with a small amount of addition, and that the obtained gel is stable over a long period of time. Furthermore, depending on the application, it is required to have high safety for the human body, to produce a gel having thixotropy, and to have a good tactile feel of the obtained gel.

  Conventionally, as oil gelling agents, low molecular weight gelling agents (1,2,3,4-dibenzylidene-D-sorbitol, 12-hydroxystearic acid, amino acid derivatives, etc.), polymer gelling agents (polyacrylic acid derivatives) , Dextrin derivatives, etc.) are known. Low-molecular gelling agents self-assemble in oil and form a huge network structure, and the oil becomes non-fluidized to form a gel. On the other hand, high-molecular gelling agents are intertwined in a complex network structure. Forming oil causes gelation of the oil.

  1,2,3,4-Dibenzylidene-D-sorbitol, a low molecular gelling agent, is an excellent compound that can gel various types of oils, but is safe in that it decomposes to produce benzaldehyde. Has not been put to practical use. 12-hydroxystearic acid is commercially available as a gelling agent for waste tempura oil, but lacks thixotropic properties. Moreover, since the gelling agent of an amino acid derivative is hardly soluble in oil, complicated operations such as heating at a high temperature and stirring for a long time are required to dissolve it. Moreover, such an operation has a problem in that it may cause a change in the quality of other components blended in the gel. On the other hand, a dextrin derivative of a polymer gelling agent needs to be added at a high concentration for gelation, and also causes a “sticky feeling” peculiar to polymers and is not good in use. Polyacrylic acid derivatives show good thickening gelation when added in a small amount, but when used on the skin, a “stickiness” peculiar to polymers is produced, and the feeling of use is not good.

  In order to solve these problems, a gel emulsion (Patent Document 1) containing 1 or 2 kinds of natural surfactants such as lecithin and sucrose fatty acid ester, higher alcohol, glycerin and oil has been proposed. Therefore, there is a problem that dripping or the like is liable to occur and handling property is poor, and if either higher alcohol or glycerin is missing, the effect cannot be obtained. In addition, as an oil gelling agent that is safe for the human body, an agent containing an α-aminolactam derivative as an active ingredient has been proposed (Patent Document 2). However, heating and dissolution are required, and high safety to living bodies and the environment is proposed. In addition, an oil gelling agent having excellent gelling ability, excellent usability, and good handling properties has not been obtained.

  On the other hand, oil gelation by reverse string micelles has also been reported in a small number (Non-Patent Documents 1-3). The reverse string micelle is a kind of self-assembly formed by a surfactant, and is known to cause gelation in order to form a network structure in oil. Since it has a hydrophilic environment inside the reverse string micelle, it is possible to encapsulate water-soluble drugs, enzymes, etc., and it has a feature not found in the oil gelling agent described above.

  As a typical system for forming the reverse string micelle, a three-component mixed system of lecithin / water / various oils has been reported (Non-patent Document 1). Moreover, ethylene glycol, formamide, and bile salts (Non-patent Document 3) have only been reported as substitutes for water. Normally, lecithin forms reverse spherical micelles or reverse elliptical micelles in oil, but when a small amount of water is added to this, hydrogen bonds to the phosphate groups of lecithin and the interface curvature of the molecular assembly decreases. It is believed that reverse string micelle growth occurs.

  As a problem with conventional reverse-like micelles, in reverse-like micelles consisting of typical lecithin / water / various oils, since water is contained in the ingredients, drugs that are susceptible to hydrolysis are blended. I can't. In addition, ethylene glycol and formamide, which are substitutes for water, cannot be applied to the human body because they have strong irritation to the skin, eyes, mucous membranes and the like. In addition, bile salts are surfactants derived from living organisms, but they may cause inflammation when attached to the skin, eyes, etc., and are highly safe for the living body and the environment, good gelation ability, excellent use feeling, No oil gelling agent that has all the good handling properties has been obtained.

JP-A-5-4911 Japanese Patent Application Laid-Open No. 10-256571

P. L. Luisi et al. Colloid & Polymer Science, vol.268, p.356 (1990) Yu. A. Shchipunov, Colloids and Surfaces A, vol.183-185, p.541 (2001) S. H. Tung et al. Journal of the American Chemical Society, vol.128, p.5751 (2006)

  The present invention requires an oil gelling agent and a thickened gel-like composition for forming reverse string micelles, which are required to have high safety against living bodies and the environment, excellent usability, and good gelling ability. It is an object of the present invention to provide an oil gelling agent and a thickened gel-like composition using the oil gelling agent.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used lecithin / urea as an oil gelling agent for various oils, and also used a three-component mixed system of these lecithin / urea / various oils. Thus, it is possible to obtain a thickened gel-like composition having a reverse cord-like micelle structure, and the thickened gel-like composition is extremely safe for the human body and the environment, has a good gelling performance, and has a long-term It has been found that the above problems can be solved.

  And, the present inventors include an oil gelling agent containing lecithin and urea to form reverse string micelles, and a thickened gel composition containing the oil gelling agent and various oil components to form reverse string micelles. It came to invent.

That is, the present invention
[1] An oil gelling agent which contains (a) lecithin and (b) urea and forms reverse string micelles.
[2] The oil gelling agent according to [1] above, wherein the (a) lecithin is either soybean lecithin or egg yolk lecithin.
[3] As a mixing ratio of (a) lecithin and (b) urea, 0.1 to 35% by mass of (b) urea is contained with respect to the total mass of (a) lecithin and (b) urea. The oil gelling agent according to [1] or [2] above, wherein
[4] A thickened gel-like composition comprising at least the oil gelling agent according to any one of [1] to [3] above and (c) an oil component to form reverse string micelles.
[5] The thickened gel-like composition as described in [4] above, wherein the thickened gel-like composition is at least one of cosmetics, pharmaceuticals, foods, paints, inks, and lubricating oils object.
[6] The above-mentioned [4], wherein the oil gelling agent is contained in an amount of 1 to 70% by mass with respect to the thickened gel-like composition as a mixing ratio of the oil gelling agent and (c) the oil component. Or the thickening gel-like composition as described in [5].

  The oil gelling agent that forms the reverse string micelle of the present invention has not only the advantage and effect of being environmentally friendly with high safety to living bodies and the environment, but also gels the target oil with a small amount of addition. It can be widely used as an oil gelling agent for various cosmetics, pharmaceuticals, foods, paints, inks, lubricating oils and the like. The resulting thickened gel-like composition has thixotropic properties, is difficult to drip, has good handling properties, and has long-term stability over one year. The transparency of the thickened gel-like composition can be adjusted depending on the oil gelling agent to be used, the preparation conditions of the thickened gel-like composition, and the like, from transparent to translucent, white turbidity and the intended use. In addition, it has a hydrophilic environment inside the reverse cord-like micelle structure, and has characteristics not found in conventional thickening gel-like compositions that can contain water-soluble components, drugs, enzymes, and the like.

Reverse micelle structure diagram Scatter curve diagram of small angle X-ray scattering measurement

The present invention is described in detail below. The oil gelling agent of the present invention is a material that can thicken or gel various oil components to form reverse string micelles. The oil gelling agent of the present invention contains (a) lecithin, (b) urea, and is thickened or gelled when various (c) oil components are added and mixed to form a reverse string-like micelle structure. Become a composition.

A reverse worm-like micelle is a kind of self-assembly formed by a surfactant. The surfactant is an amphiphilic substance having a hydrophilic group and a hydrophobic group in the molecule, and forms a self-assembly in water or oil according to the balance of the groups. As shown in FIG. The reverse string-like micelle in which the micelle has grown into a cylindrical shape forms a temporary network structure and forms a highly elastic gel. In addition, since it has a hydrophilic environment inside, it is possible to enclose water-soluble components, drugs, enzymes, and the like.

As a result of intensive studies on the reverse string micelles, the present inventors have found that a substance that causes reverse string micelle growth requires two conditions. One is that it has two or more functional groups capable of hydrogen bonding with the phosphate group of lecithin, and the second is that it has a slight hydrophobicity. It has been found that reverse string-like micelles can be formed with urea and various oils.

For the thickened or gel preparation obtained by the present inventors, specifically, lecithin, urea and n
-The structure of the thickened gel-like preparation formed by mixing decane was observed. The thickened gel-like preparation is transparent, has no crystal structure, is optically isotropic, and does not show a characteristic pattern as a polarized image. From the scattering curve measured by small angle X-ray scattering (SAXS), since a clear diffraction peak was not obtained, no regular structure was formed, and the thickened gel-like composition of the present invention was an inverted string micelle. It can be said that it forms.
In addition, the thickened gel composition of the present invention forms a reverse string-like micelle, and thus depends on the oil to be thickened or gelled, but is transparent if the oil itself is transparent. .

SAXS measurement was performed using Nano-STAR manufactured by Bruker AXS, Inc., the X-ray source was CuKα ray, and the output was 45 kV / 120 mA. All SAXS measurements were performed at 25 ° C.

FIG. 2 shows a thickened gel-like composition 1 (sample 1) in which 1% by mass of lecithin, 0.1% by mass of urea and 98.9% by mass of n-decane are mixed, 10% by mass of lecithin, and 1% by mass of urea. , N-decane 89% by weight thickened gel composition 2 (sample 2), lecithin 20% by weight, urea 2% by weight, n-decane 78% by weight thickened gel-like composition 3 ( With sample 3)
The scattering curve (the relationship between the scattering intensity I (q) and the scattering vector q) of the small angle X-ray scattering measurement is shown. Here, q = (4π / λ) sin θ, θ is the scattering angle, and λ is the wavelength of the X-ray. According to this, since no scattering curve showed a clear diffraction peak, it can be seen that no regular structure was formed.
In the scattering curve of Sample 1 with the lowest oil gelling agent concentration among these three samples,
The slope on the low q side of the log-log plot is -1. This suggests the presence of long rod-like particles, ie reverse string micelles. Also, Cross-sec based on the equations (1) and (2)
From the section plot, the cross-sectional radius (r) of the reverse string micelle was found to be 2.1 nm.
Here, Rc is the radius of rotation of the cross section. In addition, the exact length of the reverse string micelle could not be calculated due to the limitation of the measurement range, but the length (t) of the reverse string micelle is about 500 mm or more from the simulation using the equation (3). It was shown that.
Here, J ₁ is a linear Bessel function. In Samples 2 and 3, the low q-side scattering intensity decreased and the inclination tended to be gentle. This result shows that in Sample 2 and Sample 3, the amount of reverse string micelle per unit volume in the sample is increased. That is, it can be considered that the contribution of the structure factor is increased due to the proximity of the reverse string micelles, and the scattering intensity on the low q side is reduced.
Further, the thickened gel-like composition obtained by thickening or gelling the oil component using the oil gelling agent of the present invention is similarly formed with reverse string-like micelles in view of the gelation state and physical properties. It can be said.

(A) Lecithin as the oil gelling agent of the present invention is a mixture of naturally occurring phospholipids, such as soybean-derived soybean lecithin, egg yolk-derived egg yolk lecithin, purified lecithin with increased purity, enzyme-treated lysolecithin, etc. Modified lecithin can be used. Lecithin is an amphoteric phospholipid having two alkyl chains, and is widely used as a food emulsifier in emulsification of dairy products, reduction in viscosity of chocolate, and in pharmaceutical preparations. Moreover, it is a hydrophobic amphoteric surfactant and has high safety to living bodies and the environment. In the present invention, it is preferable to use soybean lecithin and egg yolk lecithin among lecithins.

(B) Urea as an oil gelling agent of the present invention is widely used as a raw material for moisturizing creams, fertilizers and urea resins, and in particular, it controls the evaporation, absorption and retention of moisture in the skin.
It is known to be one of the main components of MF (natural moisturizing factor), and to act on proteins that make up the keratin on the skin surface, and also to remove excess keratin. Since urea is originally a biological component as skin tissue, it has no toxicity to the human body, is highly safe, and is industrially inexpensive and easy to obtain.

The mixing ratio of (a) lecithin (b) urea constituting the oil gelling agent of the present invention may be in any range as long as it is a mixing ratio capable of forming reverse string micelles. (A) 1 to 70% by mass of lecithin, preferably 1.5 to 45% by mass, more preferably 2 to 25% by mass, (b) 0 to urea
. 1 to 20% by mass, preferably 0.15 to 10% by mass, more preferably 0.2 to 3% by mass
It can be. The mass proportion of (b) urea with respect to the total amount of the oil gelling agent varies depending on (c) oil component, but it is experimentally expressed as mass percentage of (b) component / ((a) component + (b) component). The lower limit is 0.1% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and the upper limit is experimentally 35% by mass or less, preferably 25% by mass or less, more preferably 15% by mass or less. It is.

The oil component (c) that can be gelled in the present invention is not particularly limited, and is oil such as animal and vegetable oils, mineral oils, hydrocarbons, and fatty acid esters. Only polar oil, nonpolar oil, or a mixture of polar oil and nonpolar oil may be used. Specifically, fish oil such as fish oil, liver oil, whale oil, head oil, lard, horse oil, sheep oil, animal oil, vegetable oil such as animal oil, palm oil, palm oil, cacao butter, olive oil, rapeseed oil, linseed oil, etc .; Liquid paraffin, isoparaffin, kerosene, heavy oil, n-decane, isooctane, n-octane, n-
Hydrocarbons such as heptane, n-hexane, cyclohexane; lauric acid, palmitic acid,
Examples include higher fatty acids such as stearic acid, oleic acid, and behenic acid, and fatty acid esters such as isopropyl myristate, 2-octyldodecyl myristate, and isopropyl palmitate. These oils can be used singly or as a mixture of two or more.

The oil to be gelled may be dissolved, dispersed, emulsified, suspended or mixed at a concentration that does not hinder thickening or gelling of the added component. Examples of such additive components include surfactants, depending on uses such as cosmetics, pharmaceuticals, foods, paints, inks, and lubricating oils.
UV absorbers, moisturizers, preservatives, preservatives, bactericides, antioxidants, fluidity improvers, fragrances, pigments, enzymes, bioactive substances, etc., organic compounds or titanium oxide, talc, mica, water, etc. Inorganic compounds can be mentioned.

When gelling the oil component (c) with the oil gelling agent containing (a) lecithin (b) urea of the present invention, the oil gelling agent is thickened or gelled with respect to the oil component, and the reverse string-like micelles are formed. Any amount can be mixed as long as it can be formed. As a mixing ratio of the oil component, (a) lecithin is 1 to 70% by mass, preferably 1.5 to 45% by mass, more preferably 2 to 25% by mass, and (b) urea is 0.1 to 20% by mass. When the content is 0.15 to 10% by mass, more preferably 0.2 to 3% by mass, (c) the oil component is 30 to 99% by mass, preferably 50 to 98% by mass, more preferably 70 to It can be 97 mass%.

Further, the mixing ratio of the oil gelling agent to the thickening gel-like composition is defined as ((a) component + (b)
Component) / ((a) component + (b) component + (c) component), the lower limit is 1% by mass or more, preferably 1.5% by mass or more, more preferably 2% by mass or more. Yes, upper limit is 70
It is not more than mass%, preferably not more than 50 mass%, and more preferably not more than 30 mass%. By adding within this range and adding and mixing the oil component, the thickened gel-like composition can be obtained. Gel strength depends on the concentration of oil gelling agent and (a) lecithin and (b)
It is possible to adjust by the mixing ratio of urea.

The thickening gel-like composition of the present invention contains (a) lecithin (b) urea, various (c) oil components, and other additive components as necessary, and is uniformly dissolved. By
It can be gelled to form a reverse string-like micelle structure. As an example of preparation of the thickened gel composition, (a) component: an organic solvent solution of lecithin and (b) component: urea are respectively sealed in a container, stirred, and completely (b) component: urea. After the organic solvent is dissolved, the organic solvent is completely evaporated by drying under reduced pressure, and then (c) the required amount of the oil component is added and further stirred overnight, and the container is placed in a room temperature constant temperature bath for stabilization as needed. It can be obtained by standing for days. It can also be prepared by dissolving a mixture of (a) lecithin, (b) urea, and various (c) oil components by heating and cooling to room temperature. The heating at this time may be any temperature as long as the mixture dissolves, but is preferably in the range of 50 ° C to 80 ° C. At this time, in order to prevent lecithin from being oxidized, it is preferably carried out in a nitrogen atmosphere or by adding an antioxidant. The thickening gel-like composition is produced immediately by adding, mixing, and stirring each component, and long-time stirring and standing for stabilizing the gel-like material is appropriately performed as necessary. It only has to be set, and in some cases it is not necessary.

Examples of the organic solvent used when preparing the thickened gel composition include methanol, ethanol,
Lower alcohols such as propanol and butyl alcohol; polyhydric alcohols such as ethylene glycol and propylene glycol; ketones such as acetone, 2-butanone and cyclohequinone; ethers such as tetrahydrofuran and 1,4-dioxane; ethyl acetate and acetic acid Esters such as butyl; Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; Chloroform, carbon tetrachloride, dichloromethane, dichloroethane, isopropyl bromide, ethyl bromide, dichlorobenzene, tetrachloroethane, trichloroethane, There are halogenated hydrocarbons such as trichlorethylene and ethylene tetrachloride; water, etc. Among them, it is preferable to use a lower alcohol. These organic solvents may be used alone or in combination.

The thickening gel-like composition of the present invention can be used as various products exhibiting a gel state at room temperature as a cleaning agent, cosmetics, medicine, food, deodorant, bath agent, fragrance, deodorant and the like. Especially suitable for use in detergents, cosmetics and pharmaceuticals. Examples of the detergent include food detergents, dish detergents, kitchen detergents, facial cleansers, body soaps, shampoos, rinses and the like. As cosmetics, cream, emulsion, lotion, cleansing, bath cosmetic, moisturizing cosmetic,
Examples include blood circulation promotion / massage agents, pack cosmetics, and hair cosmetics. As a medicine,
Examples include ointments, molded cataplasms, sustained-release preparation bases, transdermal preparations, drug delivery system carriers, gels for electrophoresis, and the like.

In cosmetics, components used in ordinary general cosmetics can be blended. For example,
Examples include fragrances, pigments, preservatives, antioxidants, anti-inflammatory agents, UV absorbers, UV reflectors, pH adjusters, and various other medicinal ingredients such as hyaluronic acid, allantoin, vitamins. , Amino acids, placenta extract and the like, and can be blended appropriately alone or in combination.

The thickened gel-like composition formed by adding and mixing various oils to the oil gelling agent of the present invention has a reverse string-like micelle structure, so it has a hydrophilic environment inside and is a water-soluble component・ It is possible to enclose drugs and enzymes. These reverse string micelles are nanometer-scale extremely fine molecular aggregates, and these reverse string micelles form a string with polar groups of lecithin and urea facing inward and hydrophobic groups facing outward. Since many are gathered, a hydrophilic environment, that is, a small water pool (water phase) is formed inside. Examples of water-soluble substances that can be encapsulated include whitening agents, anti-inflammatory agents, antibacterial agents, hormone agents, vitamins, various amino acids and their derivatives, enzymes, antioxidants, hair restorers, and other pharmaceutical ingredients. It is done.

In the thickened gel-like composition formed by adding and mixing various oils to the oil gelling agent of the present invention, a water-soluble substance, a water-soluble drug, and an enzyme that are hardly soluble or insoluble in oil are directly or When the aqueous solution is contacted, mixed and stirred, the water-soluble substance is taken into the reverse string micelle and can be dissolved in the thickening gel. The transparency of the formed thickened gel-like composition can be adjusted according to the oil gelling agent used, the preparation conditions of the thickened gel-like composition, and the like, from transparent to translucent, white turbid, and the application used.

The oil gelling agent of the present invention is excellent in gelation ability for various oils, can form a stable gel for a long time even when added at a low concentration, and particularly a gel of higher hydrocarbons has excellent thixotropic properties, and There is no shortcoming such as "stickiness" in touch. In addition, the oil gelling agent of the present invention is made of material components such as lecithin and urea that are highly safe and biodegradable for living bodies and the environment, and is an environmentally conscious type.
The oil gelling agent of the present invention is further used in fields other than the above, such as quasi-drugs, inks, paints, lubricating oils, plastics, rubbers, metals, etc., as well as agriculture, fisheries, waste oil treatment, etc. be able to.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, unless otherwise specified, a compounding quantity is shown by the mass%.

[Evaluation of thickening gel composition]
Viscosity measurement was performed at a constant temperature of 25 ° C. using a cone plate (diameter 60, 35 mm, cone angle 1 ° and 4 °) and a rotational rheometer (RheoStress 600, manufactured by HAAKE) equipped with a Peltier temperature controller. In addition, in order to prevent evaporation of a solvent, it measured using the solvent trap. Specifically, the sample was sandwiched between the cone plate and the sample stage, and the cone plate was rotated in a fixed direction to apply a shear rate stepwise to the sample. The shear stress was calculated for each shear rate, and the viscosity was calculated from the relationship of viscosity = shear stress / shear rate.
Moreover, based on this, the state of thickening gelation was evaluated as follows.
◎ Gelation (100 Pa · s or more): ○ Thickening (10 Pa · s or more and less than 100 Pa · s): x Insufficient thickening gelation (less than 10 Pa · s)

[Storage stability of thickened gel composition]
Confirmation of storage stability was achieved by using the thickened gel composition prepared in Examples and Comparative Examples with a diameter of 27.5 mm.
, Sealed in a 70 mm high sample bottle and stored for 6 months in a thermostatic chamber set at 25 ° C.
The separated state of the thickened gel composition was visually observed, and the storage stability was evaluated according to the following criteria.
◎ Good: ○ A small amount is separated: × Bad

[Examples 1 to 6]
(Formulation of thickening gel composition)
(A) As a component lecithin, soybean lecithin (trade name “L-α-Phosphatidylcholine (Soy-
95%) "Avanti Polar Lipids, Inc.), (b) component urea (manufactured by Kanto Chemical Co., Inc.), (c)
As an ingredient, n-decane (0.774 mPa · s (25 ° C.) manufactured by Kanto Chemical Co., Inc.)
A thickening gel composition was prepared as the composition shown in FIG. Depending on each compounding composition, Examples 1 to
It was set to 6.

(Preparation of thickened gel composition)
Preparation of the thickened gel composition is as follows: (a) component: methanol solution of lecithin, (b) component:
Urea was sealed in a required amount of each bottle and stirred using a magnetic stirrer. (B) component: After urea is dissolved, methanol is completely evaporated by drying under reduced pressure. (
c) The required amount of oil component was added and further stirred overnight, and the bottle was prepared by allowing it to stand in a thermostatic bath at 25 ° C. for several days for stabilization. In addition, also in the following Examples 1-9 and Comparative Examples 1-4, preparation of a thickening gel-like composition was based on the same preparation means.

In Examples 1 to 6, (a) component: lecithin was prepared at 2.0 to 25.0 mass% to prepare a thickened gel composition. The proportion of urea in these oil gelling agents, ie component (b) /
((A) component + (b) component) is 9 to 11% by mass, the ratio of the oil gelling agent in the thickened gel composition, that is, ((a) component + (b) component) / ((a) (Component + (b) component + (c) component) is 2% by mass to 28% by mass. The state of the thickening gel was transparent, both were gelation ◎ to ○, and the storage stability was also ◎ good. The state of the gel of Example 1 was a thickening ◯, but there was no problem in use. The evaluation results are shown in Table 1.

[Examples 7 to 9]
(Formulation of thickening gel composition)
(A) As the component lecithin, soybean lecithin (trade name “L-α-Phosphatidylcholine (So
y-95%) "Avanti Polar Lipids, Inc.), (b) component urea (manufactured by Kanto Chemical Co., Inc.), (c
) As a component, n-hexane (0.273 mPa · s (25 ° C.) manufactured by Kanto Chemical Co., Ltd.)
As a blending composition shown in Table 1, a thickened gel composition was prepared as Example 7.
Next, component (c) is n-octane (0.485 mPa · s (25 ° C.) manufactured by Kanto Chemical Co., Inc.)
Example 8 was prepared by preparing a thickened gel-like composition as the composition shown in Table 1.
Further, the component (c) was changed to liquid paraffin (146 mPa · s (25 ° C.) manufactured by Kanto Chemical Co., Inc.), and a thickened gel-like composition was prepared as a composition shown in Table 1 to obtain Example 9.

The ratio of urea in the oil gelling agents of Examples 7 to 9, that is, (b) component / ((a) component + (b
) Component) is 3% to 12% by weight, and the ratio of the oil gelling agent in the thickened gel composition ((a
) Component + (b) component) / ((a) component + (b) component + (c) component) is 10 mass% to 11
Mass%. The state of the thickening gel was transparent, both of which were gelled ◎ to ◯, and the storage stability was also 良好 good. The state of the gel of Example 7 was a thickening ◯, but there was no problem in use. The evaluation results are shown in Table 1.

[Examples 10 to 13]
(Preparation of thickened gel composition)
Preparation of the thickened gel composition was carried out in Examples 3, 7, 8, and 9, in which (a) component: lecithin, (b) component: urea, and (c) oil component were sealed in the required amount bottles, respectively. It was prepared by heating and dissolving at about ° C. and cooling to room temperature. At that time, it was performed in a nitrogen atmosphere to prevent oxidation of lecithin.
As a blending composition shown in Table 2, a thickened gel composition was prepared. It was set as Examples 10-13 according to each compounding composition.

According to Examples 10 to 13, (a) component: lecithin is 10% by mass, (b) component: urea, (c) component: n-decane, n-hexane, n-octane, and liquid paraffin are required. The thickened gel-like composition was prepared by using an amount, and the state of the thickened gel was both gelled and the storage stability was excellent. The transparency of the gel is determined by enclosing the thickened gel-like composition in a sample bottle with a diameter of 27.5 mm and a height of 70 mm and storing it in a thermostatic bath set at 25 ° C. for 6 months, and then UV-visible. The transmittance was measured at a wavelength of 550 nm using a spectrophotometer (V-530, manufactured by JASCO Corporation). The transmittance was evaluated as transparent: 1, translucent: 2, white turbidity: 3 based on transmittances of 100 to 90%, 89 to 50%, and 49% or less. The evaluation results are shown in Table 2.
The transparency was all transparent.

[Comparative Examples 1-4]
(Formulation of thickening gel composition)
(A) Ingredient: As lecithin, soybean lecithin (trade name “L-α-Phosphatidylcholine (So
y-95%) ”Avanti Polar Lipids, Inc.) 10% by mass, (c) as component n-decane (
A thickened gel-like composition was prepared using 90% by mass (manufactured by Kanto Chemical Co., Inc.) as a blending composition, and was designated as Comparative Example 1. A thickened gel composition was prepared as Comparative Example 2 in the same manner as Comparative Example 1 except that the component (c) was changed to n-hexane (Kanto Chemical Co., Ltd.). (C) n-octane (Kanto Chemical Co., Ltd.)
A thickened gel-like composition was prepared as Comparative Example 3 in the same manner as in Comparative Example 1 except that the product was changed to (manufactured).
Further, a thickened gel composition was prepared as Comparative Example 4 in the same manner as Comparative Example 1 except that the component (c) was changed to liquid paraffin (manufactured by Kanto Chemical Co., Inc.).

  In Comparative Examples 1 to 4, since the urea (b) component was not used, a thickened gel could not be formed. Table 1 shows the composition and the evaluation results. In contrast, in the present invention, as shown in the examples, the oil component (c) n-decane has a viscosity increase of 2.5 million times at 0.774 mPa · s at 25 ° C. At 25 ° C, 0.273 mPa · s, 2 million times the viscosity increase, n-octane, 0.485 mPa · s at 25 ° C, 4 million times the viscosity increase, and liquid paraffin, 146 mPa · s at 25 ° C However, a viscosity increase of 5,000 times was easily obtained. Note that a thickening gel could not be formed even with the urea component (b) and the oil component (c).

According to the present invention, an oil gelling agent capable of forming reverse string micelles by a three-component mixed system of lecithin / urea / various oils can be provided. It has a hydrophilic environment inside the reverse string micelle and can contain water-soluble components, drugs, enzymes and the like. It can be widely used as an oil gelling agent for various cosmetics, pharmaceuticals, foods and the like. Furthermore,
The thickening gel composition formed by using the oil gelling agent has thixotropic properties, good handling properties, and good long-term stability.

Claims (6)

  (A) An oil gelling agent which contains lecithin and (b) urea and forms reverse string micelles. The oil gelling agent according to claim 1, wherein the (a) lecithin is either soybean lecithin or egg yolk lecithin.   As a mixing ratio of the (a) lecithin and (b) urea, 0.1 to 35% by mass of (b) urea is contained with respect to the total mass of (a) lecithin and (b) urea. The oil gelling agent according to claim 1 or 2, characterized by the above. A thickening gel-like composition comprising at least the oil gelling agent according to any one of claims 1 to 3 and (c) an oil component to form reverse string micelles. The thickening gel-like composition according to claim 4, wherein the thickening gel-like composition is at least one of cosmetics, pharmaceuticals, foods, paints, inks, and lubricating oils. 6. The oil gelling agent is contained in an amount of 1% by mass to 70% by mass with respect to the thickened gel composition as a mixing ratio of the oil gelling agent and (c) the oil component.
The thickening gel-like composition as described in 1.