JP2010043231A - Gelling agent and gel composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gelling agent having characteristic viscoelasticity, exhibiting high stability and safety even in a temperature range around room temperature, and less irritating skin on application to the skin. <P>SOLUTION: The gelling agent includes a sucrose fatty acid ester with an HLB of 18, a monohydric alcohol having a ≥5C alkyl chain, and/or a saturated/unsaturated fatty acid having an ≥8C alkyl chain. The gel composition is obtained when the gelling agent is added to an aqueous medium to thicken or gelate it. The gel composition is used for detergents, cosmetics, pharmaceuticals and the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gelling agent and a gel-like composition, and particularly to a gelling agent and a gel-like composition using a sucrose fatty acid ester having an HLB of 18.

  In the fields of detergents, cosmetics, pharmaceuticals, and the like, various polymers, inorganic compounds, surfactants, and the like are used as gelling agents in order to improve handling properties and maintain dosage forms. For example, natural polymers such as polysaccharides and casein as polymers, synthetic polymers such as polyoxyethylene and acrylic acid polymers, and inorganic compounds include various clay minerals such as montmorillonite and silica, Furthermore, anionic, cationic, amphoteric and nonionic surfactants are appropriately selected and used as the surfactant according to the purpose and effect of the gelling agent.

  When such gelling agents are used for pharmaceuticals and cosmetics, they are naturally required to have high safety in order to be used on the human body. A feeling when used, that is, good usability is required. Also, when used as a body cleaning agent such as shampoo or body soap, it is preferable that safety is high, and a product having excellent usability is required. For this reason, the gelling agent used for the above purpose is required to have both high safety, preferable usability, and good thickening gelling ability. Nothing was known enough to satisfy the point.

For example, polymer-based materials are relatively safe and exhibit good thickening gelation ability when added in small amounts. Has a feeling of use. Clay minerals have high thixotropic properties and are refreshing to use and are preferable in terms of usability, but are liable to be separated and unstable. A variety of surfactants are used, but there are problems with safety, they are easily affected by the liquid composition such as salt concentration and pH, and the elongation at the time of application is insufficient. There was.
Patent Documents 1 to 3 show a gelling agent containing a sucrose fatty acid diester, but the feeling of use when applied on the skin was not sufficient.

For this reason, development of the gelling agent or gel-like composition excellent in safety | security, usability, and thickening gelling ability was desired.
On the other hand, it is a viscoelastic fluid that exhibits high viscosity by forming long string-like micelles called Worm-like micelles, which are entangled with each other, due to surfactant molecules that are excellent in usability. There is a system called (Non-Patent Document 1). Viscoelastic fluids have both high viscosity and great elasticity, and many studies have been made on aqueous solutions of quaternary ammonium salt surfactants in the presence of tightly bound counterions, such as cetylpyridinium salicylate. (Non-Patent Document 2). In addition, hexadecyltrimethylammonium bromide, which is another cationic surfactant, also exhibits viscoelastic behavior in the presence of a large amount of salt (Non-patent Document 3). However, these viscoelastic fluids cannot be said to be sufficiently suitable for pharmaceutical and cosmetic applications from the viewpoint of safety.

Patent Document 4 discloses hair and skin using a viscoelastic surfactant aqueous solution containing an anionic surfactant as an essential component and containing an amphoteric surfactant, a nonionic surfactant, an electrolyte, and a water-soluble polymer. A cleaning agent is shown. Among them, preferred viscoelastic behavior is described in the use of the body cleansing agent, and viscoelastic behavior in taking out from the container and application on the skin is discussed. If the elasticity is too large, coating becomes difficult, which is not preferable. On the other hand, if the viscosity is too high, the liquid remaining from the outlet of the container will be drawn forever. Appropriate solution behavior is obtained only when elasticity and viscosity are balanced. A preferable flow behavior and application behavior are that the shear elastic modulus G ₀ of the viscoelastic fluid is 50 Pa to 500 Pa, and the frequency range where the dynamic storage elastic modulus G ′ and the dynamic loss elastic modulus G ″ coincide is 0.1 rad. · s ^-1 or more 60rad · s ^-1 are to be obtained when it is less. Furthermore, the inventors these are particularly G ₀ is 100Pa or more, the dynamic and dynamic storage modulus G ' the range of frequencies the loss modulus G "is coincident is around 0.01, and more particularly when it is less 0.001 rad · s ^-1 or 1 rad · s ^-1, gel composition exhibits a characteristic viscoelastic Found that you can get.

  Furthermore, in Patent Document 5, a sucrose fatty acid ester or / and a polyglycerin fatty acid ester of a specific range of HLB and a surfactant of a specific range of HLB are used in combination, and the thickening exhibits viscoelastic behavior with excellent usability. Although a gelling agent is described, the thickened gel composition obtained here loses viscoelasticity over time when stored in a temperature range where the excellent viscoelasticity is about room temperature (30 ° C. or lower), and is stable. Viscoelasticity was not obtained.

As described above, the gel composition having the above viscoelastic behavior has been desired to be developed for use in pharmaceuticals and cosmetics because it has a stable usability even in a temperature range of about room temperature.
JP-A-5-279651 JP-A-7-26244 JP 7-26245 A U.S. Pat. No. 596550 JP 2005-82650 A Current Opinion in Colloid & Interface Science 6 (2001) 451-456 H. Hoffmann and H.M. Rehage, in Surfactant Solutions, Surfactant Science Series, vol. 22, R.M. Zana, Ed. , New York, 1987, p. 209 A. Khatory et al, Langumuir, vol. 9, p. 1456 (1993)

  As mentioned above, high safety, low skin irritation, and good thickening gelation ability are required when using gelling agents and gel-like compositions in body cleaners, cosmetics, pharmaceuticals, etc. However, in the prior art, it was not possible to obtain a sufficient gelling agent having all of them. In particular, conventional gelling agents and gel-like compositions have a problem of strong irritation to the skin due to the use of ionic surfactants.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific range of HLB sucrose fatty acid ester and a specific monohydric alcohol or a specific fatty acid considered to be less irritating to the skin. By using it together, the gelling agent which has the gelation ability which shows said outstanding viscoelastic behavior was found.

  By using the gelling agent of the present invention, it is possible to obtain a gel-like composition having a characteristic viscoelasticity and having low irritation to the skin and high safety even when applied to the skin.

Hereinafter, the present invention will be described in detail.
(1) Gelling agent The gelling agent is an agent that thickens and gels the aqueous medium to which it is added. The gelling agent of the present invention is a sucrose fatty acid ester having an HLB of 18 as the following component (a), a monohydric alcohol having an alkyl chain having 5 or more carbon atoms as the component (b-1) and / or (b -2) The saturated or unsaturated fatty acid whose carbon number of the alkyl chain which is a component is 8 or more is contained.

  In addition, in this invention, HLB of the sucrose ester which is a component is defined by the following Griffin formula.

(Equation 1)
HLB = (molecular weight of hydrophilic group / molecular weight of surfactant) × 20

<(A) component: sucrose fatty acid ester>
The sucrose fatty acid ester used in the present invention has an HLB of 18. If the HLB is too low, the solubility in water may decrease and precipitation may occur. If the HLB is too high, the micelle formation ability may decrease and gelation may not occur.
The constituent fatty acid of the sucrose fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid, may be a linear fatty acid or a branched fatty acid, and may further have a substituent such as a hydroxyl group. The carbon number of the constituent fatty acid is usually 6 or more, preferably 10 or more, more preferably 12 or more, and usually 22 or less, preferably 18 or less, more preferably 16 or less. When the number of carbon atoms of the constituent fatty acid is too small, the micelle forming ability may be reduced and thickening gelation may not occur. When the number is too large, the melting point becomes high and stability at low temperatures may be reduced. Two or more of these fatty acids may be used in combination.

Specifically, as these fatty acids, for example, caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, lauric acid, isotridecanoic acid, myristic acid, palmitic acid, partoleic acid, stearic acid, isostearic acid, Examples include oleic acid, linoleic acid, behenic acid, erucic acid, ricinoleic acid, and hydroxystearic acid.
The monoester content of the sucrose fatty acid ester is 90-100%. If the monoester content is low and there are many components above the diester, lamellar liquid crystals can be formed more easily than string-like micelles, and thickening gelation may not occur. I can't get it.

<(B-1) component: monohydric alcohol>
The alcohol used in the present invention is a monovalent alcohol having one hydroxyl group and has 5 to 18 carbon atoms, preferably 5 to 9 carbon atoms. If the number of carbon atoms is too large, the kraft point of the system rises and solids may precipitate.
The structure of the alkyl chain of the monohydric alcohol may be saturated or unsaturated, and may be linear or branched. Two or more of these alcohols may be used in combination.
Specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, dodecanol, hexadecanol, octadecanol, isostearyl alcohol, octadecenol, octadecedienol and the like.

<(B-2) Component: Fatty acid>
The fatty acid used in the present invention has 8 to 18 carbon atoms. If the number of carbon atoms is too large, the kraft point of the system rises and solids may precipitate.
The structure of the fatty acid alkyl chain may be saturated or unsaturated, and may be linear or branched. Two or more of these fatty acids may be used in combination.
Specifically, hexanoic acid, peptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, heptadecanoic acid, hexadecanoic acid, hexadecenoic acid, heptadecanoic acid, octadecanoic acid, octadecenoic acid, octadecadienoic acid, octadecanoic acid And decatrienoic acid.

<Mixing ratio of gelling agent>
The mixing ratio of the component (a) and the component (b) is such that the component (b) / (the component (a) + the component (b)) is wt%, usually 1% or more, preferably 5% or more. Usually, it is 15% or less, preferably 10% or less.

<Method for preparing gelling agent>
The gelling agent of the present invention does not necessarily need to be homogenized. However, it is easier to prepare a gel-like composition and the preparation time can be shortened. The homogenization of the gelling agent can be performed by stirring and mixing the components. When the viscosity is too high at room temperature and mixing is difficult, stirring and mixing may be performed in a state where the fluidity is increased by heating. In addition, when mixing the powdery component and the liquid component, first dissolve the powdery component in an appropriate solvent such as water or alcohol, and then add the liquid component thereto and mix with stirring. Then, the solvent may be distilled off for preparation.

(2) Gel-like composition The gel-like composition of the present invention is a thickened or gelled composition, and contains a gelling agent and an aqueous component. A preferable mixing ratio of the gelling agent and the aqueous component is that the gelling agent / (gelling agent + aqueous component) is in weight%, usually 0.01% or more, preferably 0.1% or more, more preferably 1%. These are usually 70% or less, preferably 50% or less, and more preferably 30% or less.

<Aqueous component>
The aqueous component contained in the gel composition of the present invention usually means water, but may be a mixed solution of water and alcohol such as ethanol, ethylene glycol, glycerin, propylene glycol or the like. In the case of a mixed solution of water and alcohol, the mixing ratio is not particularly limited, but the water content is usually 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight in the solvent. That's it.

<Other ingredients>
The gel composition of the present invention may contain other components depending on its use. For example, when used for a cleaning agent, a chelating agent may be blended in order to sufficiently exert the cleaning power. By using this chelating agent, not only can the white turbidity of the hard water aqueous solution due to the generation of scale in hard water containing calcium, magnesium, etc. be prevented, but also the detergency, foaming power and foam feel in hard water can be maintained it can. Such a chelating agent is not particularly limited, and those used in the past are used, and specifically, citrate, malate, tartrate, glutamate, pyrophosphate, polyacrylate, polymaleic acid Salt, gluconate, nitrilotriacetic acid salt, acrylic acid-maleic anhydride copolymer salt, maleic anhydride-methyl vinyl ether copolymer salt, maleic anhydride-olefin copolymer salt, maleic anhydride-methacrylic acid copolymer Examples of the salt of coalescence, maleic anhydride-tartaric acid condensate, zeolite, tripolyphosphate, ethylenediaminetetraacetic acid (EDTA), ethylenediamine and the like. Among these, citrate, malate, tartrate, glutamate, pyrophosphate, etc. are highly safe to the human body, have no environmental pollution, and water, alcohol, etc. constituting the gel composition It is preferably used because of its high compatibility and excellent cleaning power, dirt dispersibility, foaming power, and foam feel. One or more chelating agents selected from these groups are usually contained in the gel composition of the present invention in an amount of 0.01 to 50% by weight, preferably 1 to 30% by weight.

  In addition to the above, the gel composition of the present invention may be added by selecting any of the additive components commonly used in ordinary detergent compositions within a range that does not impair the object of the present invention. May be. Examples of such additional components include organic acid monoglycerides, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ether sodium sulfate, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid alkanolamides, Or a carboxybetaine type, an imidazolinium type, a sulfobetaine type, a surfactant that is mild to the human body such as an amino acid surfactant, an inorganic builder such as sodium carbonate, sodium sulfate, sodium chloride, magnesium sulfate, calcium chloride, Fluidity improvers such as glycerin, ethanol, propylene glycol, polyethylene glycol, thickeners such as carboxymethylcellulose, hydroxyethylcellulose, and more Fee, colorants, humectants, disinfectants, enzymes, and the like anti-inflammatory agents.

<Method for preparing gel composition>
The gel composition of the present invention can be obtained by uniformly dissolving a gelling agent and, if necessary, other components in an aqueous component.

(3) Detergents, cosmetics and pharmaceuticals containing a gel composition
The gel composition of the present invention can be used for various products exhibiting a gel at normal temperature as a cleaning agent, cosmetics, medicine, food, deodorant, bath agent, fragrance, deodorant and the like. Above all, it is suitable for use in detergents, cosmetics and pharmaceuticals. Examples of the cleaning agent include food cleaning agents, dish cleaning agents, kitchen cleaning agents, facial cleansers, body soaps, shampoos, rinses and the like. Cosmetics include creams, emulsions, lotions, cleansing agents, bath cosmetics, moisturizing cosmetics, blood circulation promoting / massaging agents, pack cosmetics, hair cosmetics, and the like. Examples of pharmaceuticals include ointments, molded cataplasms, sustained-release preparation bases, drug delivery system carriers, gels for electrophoresis, and the like. Gel-like compositions are mainly used as pharmaceutical bases.

(4) Dynamic viscoelastic behavior of gel-like composition The gel-like composition obtained by the present invention preferably exhibits the behavior of Maxwell fluid. In the Maxwell fluid, the following equation is established in the dynamic viscoelasticity.

(Equation 2)
G ′ = G ₀ ω ² τ ² / (1 + ω ² τ ² )

(Equation 3)
G ″ = G ₀ ωτ / (1 + ω ² τ ² )

Here, ω (rad · s ⁻¹ ) is frequency, τ (s) is relaxation time, G ₀ (Pa) is shear modulus, G ′ (Pa) is dynamic storage modulus, and G ″ (Pa) is Dynamic loss modulus.

In this equation, ωτ> 1 on the high frequency side, that is, the region where the shear rate is high, and G ′ and G ₀ are substantially equal. When G ′ = G ″, G ₀ = 2G ′ and τ = 1 / ω.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to an Example. In addition, unless otherwise specified, the blending amount is indicated by weight%.
[Preparation of gel composition]
A gel composition was prepared using a surfactant having the composition shown in Table 1, an alcohol, and a fatty acid as gelling agents. The gel composition was prepared by adding the component (a), the component (b) and the aqueous component and stirring and mixing them.

[Thickening gelation state]
After adjusting the composition, let stand in a thermostatic bath at 30 ° C for 1 day, evaluate the presence of solid precipitation and the state of thickening gel as static viscosity at 25 ° C using ARES1KFRTN1-FCO of Rheometric Scientific FE Ltd. The viscosity (Pa · s) at a shear rate of 0 was measured. Moreover, based on this, the state of the thickening gel was evaluated in five steps as follows. The results of each Example and each Comparative Example are as shown in Table 1.

Static viscosity measurement result Visual observation Evaluation
More than 100Pa ・ s Viscoelastic gel ◎
10 Pa ・ s or more and less than 100 Pa ・ s Gel form ○
Measurement not possible due to solid precipitation Gelation but solid precipitation △
Less than 10Pa ・ s No gelation ×
Not measurable due to phase separation Composition is separated XX

[Measurement of dynamic viscoelasticity]
For Examples 2, 4, 6 and 8, G ′ and G ″ were measured using ARES1KFRTN1-FCO of Rheometric Scientific FE Ltd. in order to measure dynamic viscoelasticity. 4 shows.

[Dynamic viscoelastic properties]
In Examples 2, 4, 6 and 8, G ₀ is 100 Pa or more, and from FIGS. 1 to 4, the frequency range in which the dynamic storage elastic modulus G ′ and the dynamic loss elastic modulus G ″ coincide with each other is around 0.01, detail is at 0.001 rad · s ^-1 or 1 rad · s ^-1 or less, G ', G "is in accordance with the theoretical formula of Maxwell at low frequency side. That is, Examples 2, 4, 6, and 8 show that the gel-like composition exhibits good and characteristic dynamic viscoelasticity.

It is the figure which measured the dynamic viscoelasticity of Example 2. FIG. It is the figure which measured the dynamic viscoelasticity of Example 4. FIG. It is the figure which measured the dynamic viscoelasticity of Example 6. FIG. It is the figure which measured the dynamic viscoelasticity of Example 8. FIG.

Claims (6)

(A) a sucrose fatty acid ester having an HLB of 18 and (b-1) a monohydric alcohol having an alkyl chain having 5 or more carbon atoms and / or (b-2) a saturated or saturated alkyl having 8 or more carbon atoms in the alkyl chain Gelling agent containing unsaturated fatty acid. The gelling agent according to claim 1, wherein the alkyl chain of the monohydric alcohol (b-1) is a straight chain or a branched chain. A gel-like composition containing the gelling agent according to claim 1 or 2. A cleaning agent comprising the gel composition according to claim 3. A cosmetic comprising the gel composition according to claim 3. A pharmaceutical comprising the gel composition according to claim 3.

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