JPS6135164B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a low viscosity thickening agent according to the present invention. Specifically, 100 parts of carboxyl type monomer and general formula (A) (In the formula, R represents hydrogen or a methyl group, l, m,
n represents a number satisfying 0<l+m+n≦500. ) A low viscosity thickening agent whose active ingredient is a salt copolymerized with 1.0 to 1.5 parts of an alkenyl ether. Powdered polyacrylic acid, which is obtained by polymerizing acrylic acid with various crosslinking agents, is widely used as a thickening agent for creams, lotions, and the like. These thickeners are generally susceptible to the influence of metal ions, and their viscosity decreases in the presence of metal ions. When used in shampoos, lotions, etc., metal ions are added for various purposes, so a thickening agent with high stability against metal ions and high PH stability at low viscosity is required. An object of the present invention is to provide a low-viscosity thickening agent that has extremely high viscosity pH stability at low viscosity and has little viscosity reduction due to metal ions. That is, the present invention improves viscosity increasing stability against pH by using as an active ingredient a salt obtained by copolymerizing 100 parts of a carboxyl type monomer and 1.0 to 1.5 parts of an alkenyl ether represented by the general formula (A). This made it possible to provide a low-viscosity thickening agent with high stability against metal ions. The compound of general formula (A) used in the present invention is
Corresponding alcohols include allyl chloride,
It is synthesized by the action of methallyl chloride, and in the present invention, one kind or a mixture of two or more kinds of compounds selected from the group of compounds represented by the general formula (A) is used. The carboxyl-type monomers useful in the present invention are olefinically unsaturated carboxylic acids containing at least one active carbon-carbon olefinic double bond and at least one carboxyl group. For example, it is an easily polymerizable acid in which the olefinic double bond is present at the α/β-position relative to the carboxyl group in the monomer molecule, or as a terminal methylene group, such as acrylic acid, The group consisting of methacrylic acid, itaconic acid, chloroacrylic acid, cyanoacrylic acid, α-phenylacrylic acid, α-benzylacrylic acid, crotonic acid, maleic acid, fumaric acid, sorbic acid and other olefinically unsaturated carboxylic acids It is one kind or a mixture of two or more kinds selected from. The amount of alkenyl ether used in the thickening agent of the present invention is 1.0 to 1.0 to 100 parts of carboxyl monomer.
It is necessary to use 1.5 parts; if it is less than this, the viscosity is too low and it is unsatisfactory as a thickening agent; if it is more than this, it has high thickening stability at low viscosity and is stable against metal ions. It is difficult to obtain thickeners with such properties. The copolymerization reaction is preferably carried out in a solvent that does not dissolve the copolymer obtained by mixing and dissolving the alkenyl ether represented by the general formula (A) and the carboxyl type monomer. For example, toluene, benzene, n-hexane, ethyl acetate, etc. are used. As the catalyst used for copolymerization in this method, azo-based, peroxide-based, and redox-based radical polymerization initiators can be used without any problem. For example, azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), benzoyl peroxide, cumene Examples include hydroperoxide, tertiary butyl hydroperoxide, persulfate, and a combination of persulfate and sulfite. After the polymerization reaction is completed, the thickening agent of the present invention is obtained by filtering and drying the precipitate and neutralizing the carboxyl groups of the copolymer. The thickening agent of the present invention is mainly a salt of a copolymer. However, depending on the pH at the time of neutralization, some of them may be in a free state, but of course they can be effectively used as the thickening agent of the present invention. Bases commonly used to neutralize carboxyl groups include inorganic bases such as sodium hydroxide, ammonium hydroxide, potassium hydroxide, sodium carbonate, potassium bicarbonate, and ethanolamine, dodecylamine, triethylamine, etc. of organic bases are used. The thickening agent obtained by this method has a low viscosity.
It has high viscosity increasing stability against pH and extremely low viscosity drop due to the presence of metal ions, so
It is extremely useful as a thickening agent for hair lotion shampoos, pharmaceutical cream lotions, etc. The amount of thickening agent added for thickening purposes will vary depending on the specific composition of the medium to be thickened;
Generally an amount of 1% or less is sufficient to obtain the desired viscosity. As mentioned above, the thickening agent of the present invention has the characteristics of high viscosity increasing stability against pH at low viscosity and extremely little decrease in viscosity due to the presence of metal ions. The copolymer of the monomer and allyl sucrose generates formaldehyde, which is highly toxic when stored, so there was great concern about its use in cosmetics that adhere to the human body. It also has the advantage of not allowing hair lotion,
It is extremely useful when used in shampoos, pharmaceutical cream lotions, etc., and its contribution to this industry is enormous. Examples are given below to further explain the present invention.
In the examples, parts expressed are parts by weight. Example 1 (Example of thickener manufacturing method) 20 parts of acrylic acid, 200 parts of benzene, 0.1 part of azobisisobutyronitrile, and diethylene glycol bisallyl ether were placed in a reaction vessel equipped with a thermometer, a stirring device, and a nitrogen introduction tube. were added in the proportions shown in the table below and the mixture was maintained at 45-50°C under nitrogen for 12 hours. The mixture was cooled, filtered, and dried to obtain a white light fine powder. After dispersing 3 g of this powder in 300 ml of an aqueous solution with the sodium ion concentration shown in the table below, it was neutralized to pH 7 with a 10% caustic soda aqueous solution, and the viscosity was measured (B-type viscometer unit: CPS) as shown in the table below. Ta. Separately, the relationship between pH and solution viscosity stability at a thickener concentration of 1% is shown in the figure.

[Table] Example 2 (Prescription example) Pharmaceutical cream lotion 0.24 parts of the copolymer obtained in Example 1 (using 0.25 parts of diethylene glycol bisallyl ether) was dispersed in 120 parts of distilled water, and 10% hydroxylated. The pH was adjusted to 7.2 by adding sodium. 9.6 parts of calamine, 9.6 parts of zinc oxide, and 4.8 parts of glycerin were added to this viscous liquid and stirred and mixed to form a product. Example 3 (Formulation example) Body shampoo 8 parts of the copolymer obtained in Example 1 (using 0.25 parts of diethylene glycol bisallyl ether) were added and dissolved in 445 parts of distilled water, and the pH was adjusted to 7 with a 10% aqueous sodium hydroxide solution. Neutralized. When this viscous liquid is mixed with 150 parts of a 42% aqueous solution of coconut oil, consisting mainly of lauric acid, myristic acid, and palmitic acid,
A transparent and uniform natural fatty acid tartaric acid thickened liquid was obtained in a few minutes. The PH of this thickened liquid was 10.1, the viscosity was 5650 cps (B-type viscometer), and the thickening stability was extremely good, and even when stored at 40°C, the various properties before storage were maintained for more than 3 months.

[Brief explanation of the drawing]

The drawing shows the pH of Example 1 at 1% thickener concentration.
and the stability of solution viscosity.

Claims (1)

[Claims] 1 100 parts of carboxyl type monomer and general formula (In the formula, R represents hydrogen or a methyl group, l, m,
n represents a number satisfying 0<l+m+n≦500. ) A low-viscosity thickener whose active ingredient is a salt copolymerized with 1.0 to 1.5 parts of an alkenyl ether.