JPH0318615B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel aspartic acid derivative, a method for producing the same, and a surfactant containing the same as an active ingredient. BACKGROUND ART Conventionally, liquid detergents such as kitchen detergents and shampoos have been used that have sodium alkylbenzene sulfonate as the main ingredient and have added a builder such as sodium tripolyphosphate to increase their cleaning power. However, sodium alkylbenzene sulfonate is highly irritating to the skin, causing problems such as roughness of hands, and furthermore, sodium tripolyphosphate used as a builder has caused environmental pollution problems such as eutrophication of lakes and marshes due to phosphorus. Therefore, in liquid detergents, the main ingredients are being replaced by highly safe surfactants such as sodium lauryl sulfate, α-olefin sulfonate, and alkyl ether sulfate.
However, these surfactants alone do not provide satisfactory detergency and foaming, so fatty acid alkylolamides and amine oxide surfactants, for example, are added as auxiliary agents to enhance detergency and foaming. . However, while fatty acid alkylolamides cause little irritation to the skin and are highly safe, they have a weak detergency-enhancing effect and are unsatisfactory in terms of performance. In addition, amine oxide surfactants have excellent cleaning power and foaming enhancement effects, but they are highly irritating to the skin and eye mucous membranes, and have safety issues.
The reality is that there is a strong demand for auxiliary agents for liquid detergents that are both safe and satisfactory. Therefore, the present inventor developed sodium lauryl sulfate, polyoxyethylene lauryl ether sulfate,
As a result of extensive research into compounds that enhance the detergency and foaming of surfactants used as main ingredients in liquid detergents such as α-olefin sulfonate, we found that an aspartic acid derivative represented by the following general formula met our objective. The present invention was completed after it was found to be highly safe with almost no irritation to the skin or eye mucous membranes. (However, in the formula, R ₁ is an alkyl group or alkenyl group having 8 to 18 carbon atoms, and R ₂ and R ₃ independently represent a hydrogen atom, a methyl group, or a hydroxyethyl group.) Here, by R ₁ Number of carbons shown is 8-
The alkyl group or alkenyl group of 18 may be linear or branched, for example, n-
Octyl group, n-decyl group, n-dodecyl group, myristyl group, cetyl group, 2-ethylhexyl group,
Examples include isostearyl group, stearyl group, and oleyl group. The aspartic acid derivative represented by the above general formula is a new substance and is a maleic anhydride compound with the general formula R ₂ R ₃ NH [However, in the formula, R ₂ and R ₃ independently represent a hydrogen atom, a methyl group, or a hydroxyethyl group] By reacting with the amine shown in the general formula [However, in the formula, R ₂ and R ₃ have the same meanings as above] A compound represented by the formula R ₁ NH ₂ [However, in the formula, R ₁ is an alkyl group having 8 to 18 carbon atoms or It can be easily produced and obtained by reacting with a higher aliphatic amine represented by [representing an alkenyl group]. The reaction of the present invention can be expressed as follows. That is, the method of the present invention involves a two-step reaction consisting of an acylation reaction of NHR ₂ R ₃ with maleic anhydride to produce an intermediate ('), and a Michael addition reaction of the intermediate with R ₁ NH ₂ . It is carried out by. Both the first-stage acylation reaction and the second-stage Michael addition reaction can be performed without solvent, but
It is usually convenient to carry out the reaction in a solvent. Suitable solvents include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane and heptane, alcohols such as methanol and ethanol, nitriles such as acetonitrile and propionitrile, and mixed solvents thereof. etc.
Note that a mixed solvent of the above solvent and water may be used within a range that does not inhibit the reaction. Since the production of intermediate (') by the first-stage acylation reaction can be easily confirmed by infrared absorption spectrum, once the production reaction of intermediate (') is completed, the intermediate is isolated, Alternatively, the next step of Michael addition reaction is performed without isolation. In the acylation reaction, in order to suppress the Michael addition reaction between the intermediate (') once generated and the raw material amine R ₁ R ₂ NH, maleic anhydride and the amine are
It is preferable to use HNR ₂ R ₃ in an equimolar ratio at 60°C or lower. Especially when a mixed solvent with alcohol or water is used as the reaction solvent, in order to suppress esterification and hydrolysis of maleic anhydride, The temperature is preferably 20°C or lower. On the other hand, in the Michael addition reaction, it is preferable to use higher aliphatic amine R ₁ NH ₂ in an equimolar amount to the maleic anhydride used at the beginning of the reaction, and to carry out the reaction at 50°C to 130°C. After the reaction is complete, if the target product is precipitated in the reaction solution, it can be isolated by filtration, but if the reaction yield is high, the target product can be obtained by directly concentrating to dryness. Can be done. If further purification of the target product is required, it may be recrystallized from a suitable solvent such as alcohol or acetone. The aspartic acid derivatives obtained according to the present invention may be used in the form of inorganic metal salts, inorganic acid salts or organic acid salts, and for producing these salts, Li,
Hydroxides or chlorides of Na, K, Ca, Mg, Ba, Zn, Al, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid,
An organic acid such as acetic acid or p-toluenesulfonic acid may be used. Melting points, elemental analysis values, IR,
NMR is shown in the table.

【table】

[Table] The results of the skin and eye mucosal primary irritation tests for the compounds of the present invention were as shown in the table.

【table】

[Table] Experimental method Primary skin irritation test: Closed patch using New Zealand white male rabbits, weight 3.0-3.5 kg, 6 animals per group. After one day, the patch test bandage was removed, and the degree of recovery was evaluated at 48 and 72 hours. Judgment was made by Draize's method.

[Table] Experimental method The same experimental animals as in the primary skin irritation test were used. After the eye examination, 0.1 ml of each sample was instilled into the lower eyelids of both eyes. Judgment was made by the Draize method 48 hours and 72 hours after instillation. The results of surface activity and solubility tests conducted on the compounds of the present invention are shown in the table.

[Table] Experimental method 1 Surface tension 25℃ or 60℃ using Wilhelmi surface tension meter
Measured with 2 Foaming power Measured by Ross Miles method with 0.25% aqueous solution of sample at 40℃ 3 Emulsifying power 10ml of 0.25% aqueous solution of sample and 10ml of toluene were placed in a test tube, kept at 40℃, and inverted 30 times to emulsify. ,
The constitution of the water layer that separated after 5 minutes and 30 minutes was measured. 4 Penetration Power A felt disk with a diameter of 1 inch was immersed in a 0.25% sample aqueous solution, and the time until the felt disk began to settle was measured. 5 Solubility After dissolving 0.25% sample aqueous solution once at 60℃,
The solubility was evaluated at ℃ and 40℃. Performance Test Example 1 Experimental Method A homogeneous liquid detergent is obtained by heating and dissolving 25 g of sodium dodecyl sulfate and the surfactant shown in the table in 5 ml of ethanol and 95 ml of water, and cooling. The obtained liquid detergents were diluted to predetermined concentrations and subjected to the following foaming test and dishwashing test.

[Table] Foaming test Sodium lauryl sulfate and various surfactants at 90%
They were mixed in ratios of 10, 70/30, and 50/50, and diluted with a 5/95 solution of ethanol and water so that the total surfactant concentration was 0.25%. 5 ml of the prepared sample was added to a test tube (15 x 160 mm), and the tube was inverted 20 times at 40°C, and the foam height was measured after 1 minute. Dish washing test A white meat dish with a diameter of 20 cm was turned upside down in a plastic washing basin with a diameter of 30 cm and a depth of 12 cm, and was fixed with four stainless steel weights. Next, sponge (10 x 7
x3.5) between the motor shaft and the plate.40
0.025% surfactant aqueous solution 2 heated to ℃,
It was poured down from a height of 70cm and foamed. Rotate the sponge at 124 times/minute and remove dirt (soybean oil:
10 ml of beef tallow: wheat flour = 55:30:15 was added every 3 minutes at 38°C, and the cleaning power was evaluated using the number of times of addition as the number of dishes washed. Performance Test Example 2 Experimental Method A test was conducted in the same manner as in Example 1 using polyoxyethylene lauryl sodium sulfate.

[Table] As shown in the table, the compound of the present invention is highly safe as it is non-irritating or mildly irritating to the skin and eye mucous membranes.
Because its interfacial properties such as emulsifying power and penetrating power are superior to commercially available surfactants such as sodium lauryl sulfate, imidazoline, and alkyl betaine, it is suitable as an emulsifier not only for liquid detergents such as kitchen detergents, shampoos, and solid detergents, but also for creams, etc. It can also be used as In addition, since this compound is an amphoteric surfactant,
In addition to anionic surfactants such as sodium lauryl sulfate, α-olefin sulfonate, and polyoxyethylene lauryl ether sulfate, cationic surfactants such as dodecyltrimethylammonium chloride and nonionic surfactants such as polyoxyethylene nonyl phenyl ether. It can also be used in combination with As shown in Performance Test Examples 1 and 2, 5 parts of the compound of the present invention was added to 100 parts of a commercially available surfactant.
A detergent containing at least 1 part of this compound is extremely superior in terms of detergency, foaming, etc., compared to a detergent that does not contain this compound. The present invention will be specifically explained below using Examples, but the present invention is not limited thereto. Synthesis example 1 22g of diethanolamine and 180g of acetonitrile
ml, and 200 ml of a 10% maleic anhydride solution in toluene was added dropwise thereto. After stirring for 8 hours, 37 g of laurylamine was added and heated under reflux for 7 hours.
Methanol was added to the reaction solution, the precipitated byproducts were filtered off, and the mother liquor was concentrated to dryness. 600 ml of acetone was added to the residue, and the precipitated crystals were filtered and dried to obtain 54 g of a crude product. Next, 300 ml of methanol was added and dissolved by heating, and 600 ml of acetone was added and the mixture was allowed to stand overnight. The precipitated crystals were filtered off and dried to obtain 31.4 g of N-lauryl aspartic acid diethanolamide. Melting point: 129℃. Synthesis example 2 Diethanolamine 22g, acetonitrile 180g
ml, 200 ml of a toluene solution of 10% maleic anhydride, and 25.9 g of octylamine were carried out in the same manner as in Synthesis Example 1 to obtain 22.8 g of N-octylaspartic acid diethanolamide. Melting point: 124℃. Synthesis example 3 11.1 g of diethanolamine was mixed with 90 g of acetonitrile.
ml, and 100 ml of a 10% maleic anhydride solution in toluene was added dropwise thereto. After stirring for 7 hours, 24.2 g of cetylamine was added and heated under reflux for 7 hours.
The reaction solution was treated in the same manner as in Synthesis Example 1 to obtain 11.4 g of N-cetylaspartic acid diethanolamide. Melting point: 125℃. Synthesis Example 4 50 g of a 50% aqueous solution of dimethylamine was dispersed in 25 ml of acetonitrile, and 50 ml of a 50% acetonitrile solution of maleic anhydride was added dropwise at 10°C.
After stirring for 1.5 hours, 200 ml of a 20% toluene solution of laurylamine was added dropwise and the mixture was heated under reflux for 8 hours. 500 ml of methanol was added to the reaction solution and filtered, and the filtrate was concentrated to dryness. The residue was crystallized from a mixed solvent of 500 ml of acetone and 100 ml of toluene, and then recrystallized from 250 ml of methanol to obtain 63 g of N-lauryl aspartic acid dimethylamide. Synthesis example 5 12.5g of monoethanolamine was added to acetonitrile.
The mixture was dispersed in 180 ml, and 180 ml of a toluene solution of 11% maleic anhydride was added dropwise thereto. After stirring overnight at room temperature, 37 g of laurylamine was added and the mixture was heated under reflux for 7 hours. After concentrating the reaction solution to dryness, the residue was recrystallized from a mixed solvent of acetone and methanol.
-Lauryl aspartic acid monoethalamide 50
I got g. Melting point 194-199℃. Synthesis example 6 Monoethanolamine 6.2g, acetonitrile
90ml, 11% maleic anhydride toluene solution 90ml.
The same operation as in Synthesis Example 5 was carried out using 27 g of stearylamine and 31 g of N-stearylaspartic acid monoethanolamide was obtained. Melting point: 183℃. Formulation example 1 Liquid detergent polyoxyethylene lauryl sulfate soda
24% by weight N-myristyl aspartic acid diethanolamide 4 N-lauryl aspartic acid diethanolamide 4 Urea 9 Ethanol 8 Water 51 With the above-mentioned composition, a liquid dishwashing detergent with excellent detergency and no skin irritation can be obtained. Ta. Formulation example 2 Shampoo polyoxyethylene lauryl sulfate soda
20% by weight N-cocoyl aspartic acid diethanolamide 5 Cationized cellulose 1 Propylene glycol 5 "Prodyou #200" (manufactured by Ajinomoto Co., Inc., wetting agent)
2 Water 67 With the above blended composition, a shampoo was obtained that was gentle on the hair and skin, had excellent lathering properties, and had a rinsing effect. Formulation Example 3 Solid soap N-oleyl aspartic acid diethanolamide 30% by weight N-cetyl 〃 35 N-myristyl 〃 20 Water 15 The above mixture was thoroughly kneaded with a small roll, and then extruded with a small soap roll extruder. By molding bar-shaped soap using a treadle-type molding machine, a solid soap with excellent skin gentleness and foaming properties was obtained. Formulation Example 4 Hair Rinse Oil Phase Distearyldimethylammonium Chloride
3% by weight Glycerin monosedearate 2.5 Lanolin 1.0 Cethanol 1.0 Water Phase N-lauryl aspartic acid diethanolamide 5 Glycerin 10 Cationized cellulose 1.0 Protein hydrolyzate 1.0 Water 75.5 The oil phase and the water phase were each heated to 80°C, and water was added. The oil phase was gradually added to the mixture while stirring the mixture, and the mixture was cooled to 25°C to obtain a milky rinse with excellent combability. Formulation example 5 Cream oil phase Squalane 25% by weight Beeswax 5 N-lauryl aspartic acid monoethanolamide 3 Water phase "Prodyou #100" 5 Purified water 62 The oil phase and the water phase were heated separately to 70°C, and the oil phase Add to the aqueous phase. Next, the mixture was uniformly emulsified using a homogenizer and cooled to obtain a cream. Formulation example 6 Transparent powder cleaning agent N-lauryl aspartic acid dimethylamide
8% by weight monosodium N-cocoylglutamate
32 N-lauroylglutamic acid diglycerin ester 8 1,3-butylene glycol 2 Water 50 The above blended composition is uniformly dissolved with stirring in a vacuum emulsifier maintained at 80°C. Thereafter, when cooled to room temperature, a cleansing agent was obtained that gave the skin a mild and moist feel after use and also had a beautiful transparent gel-like appearance. Formulation example 7 Transparent cleaning agent N-lauryl aspartic acid diethanolamide 30% by weight Monosodium N-cocoylglutamate
20 Ethanol 5 Glycerin 2 Water 43 The above composition was mixed, dissolved and cooled in the same manner as in Formulation Example 6 to obtain a transparent paste-like cleansing agent that was gentle on the skin and had excellent foaming cleansing properties.

Claims (1)

[Claims] 1. An aspartic acid derivative represented by the following general formula. [However, in the formula, R ¹ is an alkyl group or alkenyl group having 8 to 18 carbon atoms, and R ₂ and R ₃ independently represent a hydrogen atom, a methyl group, or a hydroxyethyl group.] 2 Maleic anhydride with the general formula R ₂ R ₃ NH [However, in the formula, R ₂ and R ₃ independently represent a hydrogen atom, a methyl group, or a hydroxyethyl group] by reacting with an amine represented by the general formula [However, in the formula, R ₂ and R ₃ have the same meanings as above] A compound represented by the general formula R ₁ NH ₂ [However, in the formula, R ₁ is an alkyl group having 8 to 18 carbon atoms or A general formula characterized by the action of a higher aliphatic amine represented by [representing an alkenyl group] [However, R ₁ , R ₂ and R ₃ have the same meanings as above] A method for producing an aspartic acid derivative represented by: 3. A surfactant containing an aspartic acid derivative represented by the general formula as an active ingredient. [However, in the formula, R ₁ is an alkyl group or alkenyl group having 8 to 18 carbon atoms, and R ₂ and R ₃ independently represent a hydrogen atom, a methyl group, or a hydroxyethyl group]