JPH08188795A - Low irritant detergent composition - Google Patents

Abstract

PURPOSE: To provide the subject detergent composition having low irritancy to humans, excellent detergency and a new composition. CONSTITUTION: This low irritant detergent composition contains a surface-active component comprising at least one or more lipophilic polyoxyethylene alkyl ethers, having <=8 number of added ethylene oxide mol and manifesting <=1.0 inorganic-organic balance(IOB) calculable from an organic conceptional diagram and at least one or more hydrophilic surfactants. At least >=55wt.% surface-active component comprises a lipophilic polyoxyethylene alkyl ether. When the number of added ethylene oxide mol in the ether is N, the lipophilic polyoxyethylene alkyl ethers comprise <=10wt.% ether having N=0 and >=50wt.% ether represented by N=X±2 (X denotes an optional positive number of <=8).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detergent composition having a novel composition having a mildness. More specifically, the present invention relates to a cleaning agent that may come into direct contact with the human body, for example, cosmetics such as shampoo, body soap and face cleansing agent, dishwashing agent, and other various cleaning agents used at home.

[0002]

BACKGROUND OF THE INVENTION Detergents used in an aqueous system usually consist mainly of a water-soluble nonionic surfactant or a water-soluble ionic surfactant and a mixture thereof. In general, ionic surfactants are irritating and tend to foam. Nonionic surfactants have the property that they are less irritating but are less likely to cause bubbles.

In recent years, there has been a strong social demand for a hypoallergenic detergent which is excellent in detergency but does not cause rough skin.
Therefore, a lot of products have come to be marketed in which a combination of a water-soluble nonionic surfactant and a water-soluble ionic surfactant is used to suppress irritation.

As the water-soluble nonionic surfactant, water-soluble polyoxyethylene alkyl ether is often used. In the case of water-soluble polyoxyethylene alkyl ether, when the polyoxyethylene chain becomes large, the mildness increases, but the detergency decreases. On the contrary, when the polyoxyethylene chain is small, the detergency is increased, but the irritation is increased and the foaming power is decreased.

Generally, in order to obtain a water-soluble polyoxyethylene alkyl ether having excellent detergency, the number of moles of ethylene oxide added is 6 to 10 moles, but that having a mildness is 15 to 15 moles. It is required to be 20 mol or more. In view of the above properties, the water-soluble polyoxyethylene alkyl ether currently in widespread use is
Ethylene oxide is added in an amount of about 10 to 15 mol.

However, it is said that even polyoxyethylene alkyl ethers to which ethylene oxide in the above range is added are polar enough to be soluble in water and oil, the irritation is strongest, The use of those that have The polarity is about 0.9-in the polarity index (IOB) that can be calculated from the organic conceptual diagram.
1.3, represented by about 10 to 15 in HLB.

Therefore, the conventionally used water-soluble polyoxyethylene alkyl ether has an addition mole number of ethylene oxide of about 10 to 15 moles, and
B indicates about 1.2 to 1.4, and HLB indicates 14 to
It had a high hydrophilicity of about 16.

As described above, even if the cleaning agent containing water-soluble polyoxyethylene alkyl ether as the main ingredient is preferable, the one having the low irritation and the one having the excellent cleaning power are the most suitable polyoxyethylenes. Because the chain length is different,
The current situation is that one with moderate properties is selected and adopted.

Furthermore, recently, a mild ionic surfactant has been developed, but a ionic surfactant which is as satisfactory as that of a nonionic surfactant has not been obtained.

[0010] As described above, even though there is currently a demand for a non-irritating detergent from a mild one to a non-irritating one, as described above, it is completely non-irritating and has an excellent detergency. Has not been obtained. On the other hand, a detergent having safety and mildness superior to those of these surfactants has not been developed.

[0011] Therefore, an object of the present invention is to solve these drawbacks and to provide a detergent composition having a novel composition having a low irritation to humans and an excellent detergency.

[0012]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in accordance with the above-mentioned object, when a lipophilic polyoxyethylene alkyl ether, which is insoluble in water, is used as a main agent, it is a detergent having low irritation and detergency. The inventors have found that an agent can be obtained and completed the present invention. Furthermore, they have found that when the distribution of the number of moles of added ethylene oxide of the ether is within a predetermined range, it is almost non-irritating to the skin and the like.

That is, according to the present invention, at least one kind of lipophilic polyoxyethylene alkyl ether having an added mole number of ethylene oxide of 8 mol or less and an IOB of 1.0 or less, and a hydrophilic surfactant. The present invention relates to a mild detergent composition comprising at least one surface active ingredient, and at least 55% by weight of the surface active ingredient comprising the lipophilic polyoxyethylene alkyl ether.

In the lipophilic polyoxyethylene alkyl ether, where N is the number of moles of ethylene oxide added to the ether, N = 0 is 10% by weight or less, and N = X ± 2. 50% by weight
When made up of the above (where X represents an arbitrary positive number of 8 or less), it can be almost non-stimulating to a person.

Also, when the surface active component contains 60% by weight or more of the lipophilic polyoxyethylene alkyl ether, a detergent composition having extremely weak irritancy can be obtained. A more preferable lipophilic polyoxyethylene alkyl ether is used when IOB having an IOB of 0.8 to 1.0 is selected.

[0016]

The polyoxyethylene alkyl ether applied to the present invention is characterized in that it is hardly soluble in water and easily soluble in oil, that is, it exhibits lipophilicity. The lipophilic surfactant is dissolved in oil which is an adhered matter as a stain, acts on the oil / solid interface to efficiently remove the oil, and further, the hydrophilic surfactant to be blended at the same time is removed from the oil. It is thought that it exerts an unprecedented cleaning action of adhering to the surface and preventing re-adhesion to the object to be cleaned.

This polyoxyethylene alkyl ether is excellent in detergency as described above, and is very weak in irritation to humans. Therefore, a detergent containing the compound as a surfactant component can be used safely and safely.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The polyoxyethylene alkyl ether applied to the present invention is one having a number of added moles of polyethylene oxide of 8 mol or less, particularly preferably 5 mol or less, and showing lipophilicity. The lipophilicity, which is one of the characteristics, means that it is hardly soluble in water at room temperature and easily soluble in oil. Specifically, it means a polarity that can be calculated from the organic conceptual diagram, that is, an IOB of 1.0 or less.

When the IOB exceeds 1.0, irritation becomes strong and solubility in water becomes high. From the viewpoint of detergency, I
OB is preferably 1.0 to 0.8. If it is less than 0.8, the detergency will be poor. When the above-mentioned polarity range is represented by HLB, it is 9 or more, and particularly 9 to 1
It is 1.

This overlaps with the above-mentioned polarity range where it has been said that the conventional stimulation is strong. Here, the polar range is a number calculated from the balance between the hydrophilic group and the lipophilic group of the surfactant molecule. The polyoxyethylene alkyl ether having the above-mentioned polar range, which has been used conventionally, had an addition mole number of ethylene oxide which governs hydrophilicity of 10 moles or more. Therefore, even if the polar range represents the above range, the solubility was maintained to some extent in water at room temperature.

However, the addition mole number of ethylene oxide of the lipophilic polyoxyethylene alkyl ether applied to the present invention is 8 mol or less, preferably 5 mol or less. That is, since they originally have few hydrophilic groups, when they represent the above-mentioned polar range, they are extremely difficult to dissolve in water.

If the number of moles of ethylene oxide added exceeds 8 moles, it becomes unsuitable because it exhibits solubility in water and also exhibits irritation.

As described above, the degree of lipophilicity of the polyoxyethylene alkyl ether is determined by the addition of the lipophilic alkyl moiety derived from the higher alcohol as the raw material and the ethylene oxide having an ether oxygen showing hydrophilicity. It depends on the number of moles. The alkyl moiety of the polyoxyethylene alkyl ether applied to the present invention may have any structure such as saturated, unsaturated or branched, but preferably has 8 or more carbon atoms. Furthermore, the alkyl moiety may be derived from a higher alcohol derivative having an alkyl glyceryl ether and a propylene oxide chain added.

For example, the higher alcohols and higher alcohol derivatives which are the starting materials for the lipophilic polyoxyethylene alkyl ether according to the present invention include the following. Examples of higher alcohols include lauryl alcohol, myristyl alcohol, cetyl alcohol, oleyl alcohol, isostearyl alcohol, and behenyl alcohol. Examples of the higher alcohol derivative include alkyl glyceryl ethers such as monolauryl glyceryl ether, monocetyl glyceryl ether, monooleyl glyceryl ether, dioctyl glyceryl ether, and dilauryl glyceryl ether.
Further, sorbitan fatty acid ester, polyglycerin fatty acid ester, alkyl polyglucoside and the like can be mentioned.

Further, the lipophilic polyoxyethylene alkyl ether according to the present invention includes those to which polyoxypropylene is further added. Examples thereof include polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene lauryl polyglucoside, and polyoxyethylene polyoxypropylene ether.

Since the cleaning composition according to the present invention is premised on use in an aqueous system in principle, it must be easily dispersed or dissolved in water at the time of cleaning. Therefore, a hydrophilic surfactant is used as a surface active component. It is necessary to mix them together.

However, it is necessary that at least 55% by weight of the lipophilic polyoxyethylene alkyl ether is blended in the surface-active ingredients of the composition. When the amount is less than 55% by weight, the mildness remains unsatisfactory. More preferably, the lipophilic surfactant is blended in an amount of 60% by weight or more, and almost no irritation can be achieved.

The term "hydrophilic surfactant" as used herein includes all water-soluble surfactants that are generally used. For example, saponin, lysolecithin, alkyl sulfates, alkyl ether sulfates and salts thereof, alkyl sulfonates, alkyl ether carboxylic acids and salts thereof, acyl isethionates, anionic surfactants such as acyl alaninate, alkyl polyglucosides, Nonionic surfactants such as sucrose fatty acid ester, polyglycerin fatty acid ester, and water-soluble polyoxyethylene alkyl ether, as well as various amphoteric surfactants and cationic surfactants.

Of these, the following are particularly preferable from the viewpoint of low irritation. In the case of water-soluble polyoxyethylene alkyl ether, for example, nonionic surfactants having an HLB of 15 or more are preferable, and for anionic surfactants, for example, alkylglycine, alkyltaurate, alkylalaninate. , Alkyl isethionate, alkyl sulphosuccinate and the like are preferable. In amphoteric surfactants, alkylamidobetaine,
Alkylimidazolinium betaine and the like are preferable, and as the cationic surfactant, alkylamidoamine and the like are preferable.

By the way, conventionally generally available polyoxyethylene alkyl ethers have an extremely wide distribution with respect to the number of moles of added ethylene oxide, centered on the desired degree of polymerization, as shown by the solid line A in FIG. 1, for example. As a mixture.

However, although the reason is not clear, the present inventors have selected a polyoxyethylene alkyl ether having a narrow distribution range in which the number of moles of added ethylene oxide is within a predetermined range as the main ingredient of the active ingredient. It was found that the irritation can be almost eliminated.

Here, the narrow distribution means that the alkylene oxide having a number of added moles N of 0 is 10% by weight or less, and the range of N = X ± 2 is 50% by weight.
It refers to those exhibiting the above distribution, for example, those exhibiting a distribution curve as shown by the dotted line B in FIG. Incidentally, X is 8
Represents any positive number below.

The polyoxyethylene alkyl ether having a narrow distribution is produced, for example, by the following method. Higher alcohols are prepared by first adding 1 mol or 2 mol of ethylene oxide to high purity, and then adding ethylene oxide to a desired number of moles according to a usual method, or by adding higher alcohols to acidic Examples thereof include a method in which ethylene oxide is added under a catalyst, a polyvalent metal catalyst such as calcium oxide or magnesium oxide, or a clay mineral containing the catalyst as a catalyst at a temperature of 100 to 150 ° C. under a low pressure.

In the past, much research has been done on polyoxyethylene alkyl ethers having a narrow distribution of the number of moles of added alkylene oxide, and they have been used as detergents.
The number of added moles is 10 moles or more, which is outside the scope of the present invention. Furthermore, the purpose was also to increase the detergency. That is, when ethylene oxide has a predetermined addition mole number, it has almost no stimulating property,
This is a matter first disclosed by the present invention.

Since the detergent composition of the present invention has extremely low irritation to the human body, it is suitable for use as a detergent which may come into direct contact with human skin. Examples include shampoos, body shampoos, cosmetics such as face wash, and cleaning agents for tableware. Since these are assumed to be used in an aqueous system, the detergent composition of the present invention is provided mainly in the form of an aqueous solution or emulsion.

The detergent composition of the present invention can be used in ordinary detergents such as various water-soluble polymers for the purpose of thickening, polyacrylic acid as a builder, various salts, etc., as long as the above requirements are satisfied. It does not interfere with the blending of various ingredients.

[0037]

EXAMPLES The present invention will be further described below with reference to examples. However, the present invention is by no means limited to these examples. In addition, "%" in the following examples means
It represents "% by weight".

Example 1 A liquid transparent face wash having the formulation shown in Table 1 was prepared. A non-irritating face wash with excellent cleaning effect was obtained.

[0039]

[Table 1]

(Notes) * 1: Polyoxyethylene (4) lauryl ether (Hereinafter, in BL-nNR, L represents a lauryl group and n represents the number of moles of ethylene oxide added.) * 2: Sodium lauryl ether sulfate (Nikko Chemicals Co., Ltd.)

<Example 2> A liquid transparent dishwashing agent having the formulation shown in Table 2 was prepared. It was a non-irritating detergent with an excellent cleaning effect.

[0042]

[Table 2]

Example 3 A face wash having the formulation shown in Table 3 was prepared. It was a cleansing agent that was transparent and had a gel-like effect with excellent cleaning effect.

[0044]

[Table 3]

(Notes) * 1: Polyoxyethylene (60) hydrogenated castor oil (manufactured by Nikko Chemicals Co., Ltd.) * 2: Sodium lauryl methyl taurate (manufactured by Nikko Chemicals Co., Ltd.)

Example 4 A body soap having the formulation shown in Table 4 was prepared. It was a clear liquid, had good bubbles, and showed excellent cleaning effect and non-irritating effect.

[0047]

[Table 4]

<Evaluation Test> The above-mentioned Examples 1 to 4 and commercially available detergents were tested for irritation and detergency according to the methods described below. About commercially available cleaning agents, Table 5
It was estimated that the composition is shown in Table 7.

[0049]

[Table 5]

[0050]

[Table 6]

[0051]

[Table 7]

The results are shown in Table 8. The product of the present invention had an extremely low irritation as compared with the conventional product, but was excellent in the cleaning effect. In particular, as shown by the results of Example 4 of the irritation test, when 60% by weight or more of the surface-active ingredient is composed of the lipophilic polyoxyethylene alkyl ether according to the present invention, irritation is very high. It turned out to be weak.

[0053]

[Table 8]

(Stimulation Evaluation Test) A test was conducted using SKIN ² kit MTT Assay manufactured by Oriental Yeast Co., Ltd. Here, MTT is an abbreviation for 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide. The method involves contacting skin cells with a sample for a predetermined time,
Only skin cells that are alive without being damaged by the sample utilize the fact that the enzyme in mitochondria shows activity, react with the MTT reagent added later, reduce MTT, and generate MTT formazan, This amount is quantified. That is, the degree of stimulation was evaluated by the concentration (SK2) at which the growth was suppressed to 1/2 in this test. The outline of the procedure is shown below.

(Method) (1) A filter paper impregnated with 50 μL of a sample (cleaning agent),
The dermis side of human skin cell tissue was brought into contact via a nylon mesh. The serum-free assay medium (main component: amino acid, saccharide) pH 6.8 to 7.2 was used as a control. (2) 120 at 37 ° C, 5% CO ₂ , humidity 90% or more
The cells were cultured separately. (3) Assay medium (main component: amino acid, saccharide, serum included) pH 6.
Rinse well with 8-7.2.

(4) 2.0 mg / prepared by a predetermined method
The cell tissue of (3) was put together with the mesh in 2 mL of MTT solution. Incidentally, a new nylon mesh was used as a blank and was similarly put into the MTT solution. (5) 37 ° C, 5% CO ₂ , humidity 90% or more for 2 hours,
Culture was performed on a shaker with shaking (150 rpm). (6) The MTT solution was removed by suction, and the mixture was washed with 1 mL of PBS having a pH of 6.8 to 7.2 at room temperature for 2 minutes × 2 times, and PBS was also removed by suction.

(7) To the cell tissues of (6), 4 mL of MTT solution (isopropanol) was dispensed and shaken (125 rpm) at room temperature for 60 minutes. (8) A predetermined amount of MTT solution was vigorously pipetted to remove the dye (MTT formazan) adhering to the cell tissue and mixed to make the color of the solution uniform.

(9) A predetermined amount of the MTT eluate obtained in (8) and the same amount of fresh MTT solution were mixed and mixed at 540 nm.
Colorimetric quantification was performed. By using the MTT eluate with the blank mesh prepared in (4) as a blank,
The MTT component attached to the nylon mesh is subtracted. (10) The concentration was plotted on the X-axis, and the value (%) calculated by the following formula for each concentration was plotted on the Y-axis. X at the intersection of the 50% point on the Y axis and the dose response curve
Evaluation item as the degree of stimulation, the density of the axis (SK2)
And

[0059]

[Equation 1]

(Evaluation test of detergency) (1) A solution obtained by dissolving 1 g of vegetable oil in 5 g of hexane is uniformly applied to a cotton cloth of 5 cm × 5 cm. This is dried at 105 ° C. and used as a sample. (2) A 1% aqueous solution of each cleaning agent was used as a cleaning solution, and the sample prepared in (1) was immersed in 200 cc of the cleaning solution,
Sonicate for 5 minutes to clean. (3) After thoroughly rinsing the sample of (2), it was dried at 105 ° C. (4) The weight of the sample before and after washing was measured, and the washing rate (%) was calculated by the following formula.

[0061]

[Equation 2]

[0062]

EFFECTS OF THE INVENTION The cleaning composition of the present invention has excellent detergency and has low irritation to the human body such as the skin, so that it does not cause skin roughness.

Further, when the width of the distribution of the number of moles of added ethylene oxide of the lipophilic polyoxyethylene alkyl ether to be blended is narrowed, or when it is contained in an amount of 60% by weight or more of the surface-active ingredient, most of the irritation is given. A non-irritating, human-friendly detergent can be provided.

[Brief description of drawings]

FIG. 1 shows distribution curves of the number of moles of added ethylene oxide in a conventional polyoxyethylene alkyl ether (solid line A) and a polyoxyethylene alkyl ether preferably used in the present invention (dotted line B).

Claims (4)

[Claims] 1. At least one or more lipophilic polyoxyethylene alkyl ethers having an addition mole number of ethylene oxide of 8 moles or less and having a polarity index (IOB) of 1.0 or less which can be calculated from an organic conceptual diagram, A mild detergent composition characterized in that a surface-active component comprises at least one hydrophilic surfactant, and at least 55% by weight of the surface-active component comprises the lipophilic polyoxyethylene alkyl ether. 2. In the lipophilic polyoxyethylene alkyl ether, when N is the number of moles of ethylene oxide added to the ether, N = 0 is 10% by weight or less, and N = X ± 2. 50% by weight is represented
The cleaning composition according to claim 1, wherein the cleaning composition is composed of the above (wherein X represents any positive number of 8 or less). 3. The detergent composition according to claim 1, wherein the surface-active ingredient contains 60% by weight or more of the lipophilic polyoxyethylene alkyl ether. 4. The cleaning composition according to any one of claims 1 to 3, wherein the lipophilic polyoxyethylene alkyl ether has an IOB of 0.8 to 1.0.