JPS60120808A - Production of dispersion of pearlescent agent - Google Patents

Abstract

PURPOSE:A pearlescent dispersion which is formed by allowing a fatty acid monoethanolamide to crystallize out in the presence of a monoalkyl type cationic surfactant is combined with a specific amount of a nonionic and water-soluble surfactant of polyoxyalkylene to improve its viscosity stability. CONSTITUTION:100pts.wt. of a fatty acid monoamide having 12-26C acyl group are allowed to crystallize out in the presence of 1-10pts.wt. of a monoalkyl type of cationic sufactant and, preferably 5-50pts.wt. of a polyoxyalkylene, water-soluble nonionic surfactant of formula: XO(AO)nH (X is a lipophilic group selected from saturated or unsaturated hydrocarbon groups of 10-16 carbon atoms, acyl groups of 6-12 carbon atoms and alkylphenyls bearing 6-12C alkyl group; A is 2-3C alkyl; n is 15-60) are added to obtain the objective high-concentration pearlescent dispersion containing 10-50% of the above amide as an active ingredient, showing excellent pearlescent luster, less viscosity change with time and high storage stability.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for producing a concentrated pearling agent dispersion containing fatty acid monoethanolamide as an active ingredient, which has improved viscosity stability.

(Prior Art) Pearl luster has been conventionally imparted to liquid or paste-like cleaning agents such as shampoos, conditioners, lotions, creams, and soaps, and other cosmetics. Pearlescent luster is imparted by adding pearlescent agents, and fish scale foil, a natural compound, has been used for a long time, but this fish scale foil is expensive and always contains impurities, causing deterioration of the product and bad smell. Therefore, synthetic products such as fatty acid esters of glycols have recently been widely used.

Known synthetic pearl agents include ethylene glycol distearate, polyethylene glycol stearate and balmitate diester, and stearate monoethanolamide. Pearling agents produce significant differences in pearlescent luster depending on their crystal shape. The most common method is to add a pearl agent to the final composition, heat it to dissolve the pearl agent, and then cool it to precipitate pearl agent crystals.

However, the method of crystallizing in the final composition requires high energy costs in the manufacturing process because the concentration of the pearl agent is on the order of a few inches, and depending on the ingredients added, it may have a negative effect on crystallization, so manufacturing conditions must be adjusted. As a way to solve these problems,
There is a method in which a highly concentrated dispersion of a pearling agent is prepared in advance and this dispersion is added to the final composition.

The present inventors crystallized Hirofatty acid monoethanolamide,
When producing a highly concentrated dispersion of a pearling agent, it was discovered that pearlescent luster could be improved by coexisting with a monoalkyl type cationic surfactant, and a patent application was filed
No. 8-110496).

However, it was found that the viscosity of this pearl agent dispersion increased over time and the fluidity decreased significantly.

(Objective) The object of the present invention is to crystallize fatty acid monoethanolamide in the presence of a monoalkyl-type cationic surfactant to produce a pearl agent with excellent pearl luster and improved storage stability with little change in viscosity over time. An object of the present invention is to provide a method for producing a highly concentrated dispersion.

(Structure) The present invention provides 100 parts of a fatty acid monoethanolamide for producing a pearling agent dispersion containing 10 to 50 fatty acid monoethanolamides having an acyl group having 12 to 26 carbon atoms as an active ingredient. is crystallized in the presence of 1 to 10 parts of a monoalkyl type cationic surfactant, and then 3 to 50 parts of a polyoxyalkylene water-soluble nonionic surfactant is added.

In the production method of the present invention, the active ingredient of the pearl agent is fatty acid monoethanolamide having an acyl group having 12 to 26 carbon atoms. In particular, the acyl group constituting the pearl agent has 16 carbon atoms or less, 40 or less, and 20 or more carbon atoms, 20 to 70 carbon atoms.
% and the average carbon number is in the range of 18 to 20.5, which gives better pearlescent luster, and is therefore preferred.

lθ in fatty acid monoethanolamide chloride dispersion
-50 inches, preferably 15-40 inches.

The monoalkyl type cationic surfactant used in the present invention is
One linear or branched alkyl group or alkenyl group having lθ to 22 carbon atoms and an alkyl group having 1 to 3 carbon atoms,
It is a quaternary ammonium salt having a benzyl group, a hydroxyalkyl group having 2 to 3 carbon atoms, and 3 selected substituents. The counter anions of this quaternary ammonium salt are chloride, bromide, ioside, etc.
Methosulfate and ethosulfate ions are suitable. Specific examples of such monoalkyl cationic surfactants include coconut alkyltrimethylammonium salts, coconut alkyldimethylbenzylammonium salts, tallow alkyltrimethylammonium salts, and stearyldimethylbenzylammonium salts. The amount of the cationic surfactant used is 1 to 10 parts per 100 parts of fatty acid monoethanolamide, and if it is out of this range, the pearlescent luster will decrease.

The polyoxyalkylene water-soluble nonionic surfactant used in the present invention has the general formula % formula %) (In formula I, X is a saturated or unsaturated aliphatic hydrocarbon group having 10 to 16 carbon atoms, 10 carbon atoms It is a lipophilic group selected from an acyl group having ~16 acyl groups and an alkylphenyl group having an alkyl group having 6 to 12 carbon atoms; ). This nonionic surfactant needs to be dissolved in the pearl agent dispersion obtained by crystallization, and it is desirable that 50% or more of the weight of the polyoxyalkylene portion of the hydrophilic group is ethylene oxide. Specific examples of such nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene coconut alkyl ether, polyoxyethylene 1-hexyl hebutyl ether, polyoxyethylene 012-Cls synthetic alcohol ether, and polyoxyethylene octylphenyl. Examples include ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauric acid ester, and polyoxyethylene coconut fatty acid ester. The amount of this nonionic surfactant used is 5 to 50 parts, preferably 10 to 40 parts, per 100 parts of fatty acid monoethanolamide.If the amount used is less than this amount, the viscosity stability may be insufficient. ,
On the other hand, if the amount is too large, the viscosity of the pearl agent dispersion becomes extremely high, which is not preferable.

In the production method of the present invention, fatty acid monoethanolamide is crystallized in the presence of a monoalkyl type cationic surfactant, and a polyoxyalkylene water-soluble nonionic surfactant is added to the crystallized dispersion. is important. Monoalkyl type cationic surfactants are effective in improving pearlescent luster when crystallizing fatty acid monoethanolamide, but they have no effect on the viscosity stability of the resulting pearling agent dispersion, so the pearls may deteriorate over time. The viscosity of the agent dispersion increases and the fluidity significantly decreases. On the other hand, polyoxyalkylene-based water-soluble nonionic surfactants have an effect on viscosity stability and can maintain fluidity, but when present during crystallization of fatty acid monoethanolamide, pearl agent It has the disadvantage of reducing gloss.

Pearling agent dispersions prepared according to the invention can be incorporated into various products containing cationic surfactants, such as hair rinses and hair treatments, to impart pearlescent luster.

(Effects) Since the production method of the present invention uses two specific types of surfactants in a specific order, it has excellent pearlescent luster and excellent viscosity stability.

(Example) Next, the present invention will be explained in further detail by showing examples. In addition, pearlescent luster was evaluated by visual judgment according to the following criteria ◇ 5: Very good 4: Good 3: Fair 2: Poor 1: Very poor Also, the viscosity stability (long-term storage stability) of the pearl agent dispersion was 45°C. The viscosity after standing for one month was measured using a B-type viscometer and evaluated as ○ for less than 10 poise, Δ for 10 to 1000 poise, and × for 1000 poise or more.

Comparative Example: 20 parts of fatty acid monoethanolamide with a weight ratio of palmitic acid/stearic acid/behenic acid -3/3/4, 0.5 part of tallow alkyltrimethylammonium chloride, polyoxyethylene lauryl ether (n-
60) Mix 5.0 parts and water to make the total amount 100 parts,
After heating to 80° C. to make a homogeneous solution, the solution was cooled to room temperature while stirring to precipitate crystals, thereby preparing a pearl agent dispersion. Next, the pearling agent dispersion and the dialkyl type cationic surfactant dispersion were mixed to contain 3% of each of the pearling agent and di-tallow alkyldimethylammonium chloride, and the pearlescent luster was evaluated, and the evaluation score was 2, which was poor. .

Mix 3 parts of fatty acid monoethanolamide used in Examples and Comparative Examples, 0.75 parts of tallow alkyltrimethylammonium chloride, and water to make a total of 100 parts, heat to 80°C to make a homogeneous solution, and then stir while stirring. It was cooled to room temperature to precipitate crystals. Next, a predetermined amount of nonionic surfactant and water were added to this crystal dispersion to obtain a pearl agent concentration of 20%.
A pearl agent dispersion was prepared.

Crystallization was carried out in the same manner without adding a cationic surfactant to prepare a pearl agent dispersion.

These pearl agent dispersions were evaluated for viscosity stability and pearl luster. Evaluation of pearlescent luster was performed in the same manner as in the comparative example.

The results are shown in Table 1. The nonionic surfactants used are shown below.

A: Polyoxyethylene lauryl ether (n-5) B: # (n-25) C: y (n-60) D: Polyoxyethylene octylphenyl ether (n
-20) E: BoIJ oxyethylene nonylphenyl ether (
n-30) F: Polyoxyethylene l-hexyl hebutyl ether (n-15) Q: # (n-30) H: Polyoxyethylene sorbitan monolaurate (n-20) I: Polyoxyethylene hydrogenated castor oil ether (n-3
0)

Claims (1)

[Claims] 1. In producing a pearling agent dispersion containing 10 to 5 (l) of a fatty acid monoethanolamide having an acyl group having 12 to 26 carbon atoms as an active ingredient, 100 parts of the fatty acid monoethanolamide is crystallized in the presence of 1 to 10 parts of a monoalkyl type cationic surfactant, and then 5 to 50 parts of a polyoxyalkylene water-soluble nonionic surfactant is added. Production method. 2. The polyoxyalkylene water-soluble nonionic surfactant has the general formula % formula %) (wherein, X is a saturated or unsaturated aliphatic hydrocarbon group having 10 to 16 carbon atoms, 10 to 16 carbon atoms) It is a lipophilic group selected from an alkylphenyl group having 16 acyl groups and an alkyl group having 6 to 12 carbon atoms, A is an alkylene group having 2 to 3 carbon atoms, and n is a number from 15 to 60. .) The manufacturing method according to claim 1.