JP4334759B2 - Method for producing chitosan-containing polymer emulsion - Google Patents

Description

【図面の簡単な説明】
【図１】 実施例１で得られた高分子エマルジョンのＴＥＭ写真である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a chitosan-containing polymer emulsion useful for skin cosmetics, hair cosmetics, pharmaceuticals, clothing detergents, clothing treatment agents, fiber treatment agents, deodorants, antibacterial / antibacterial agents and the like.
[0002]
[Prior art and problems to be solved by the invention]
Chitosan is a basic polysaccharide obtained by deacetylating chitin contained in crustacean shells such as crabs and shrimps by alkali treatment etc., making use of its unique properties, adsorbents, flocculants, cosmetic raw materials, medical It is used for a wide range of applications such as materials, antibacterial agents, and food materials. However, chitosan alone does not dissolve other than an acidic aqueous solution, and it is important to make fine particles and emulsify them.
[0003]
As for the microparticulation, there are a method in which chitosan is dissolved in an acid and then dropped into an alkali coagulating liquid, and a method in which a chitosan solution or dispersion is mechanically treated. However, in each case, only particles of about several tens of μm to several hundreds of μm can be obtained and are not dispersed in water. Regarding dispersion of fine particles in water, there is a method of making composite particles of chitosan and a polymer compound (Patent No. 2790322 and Patent No. 2817968), but the average particle size is as large as 30 μm to 100 μm, which improves the dispersion stability in water. Is insufficient. Furthermore, there is a method (JP-A-9-3106) for reducing the average particle size to 1 μm or less, but it is inevitable that a non-polymerizable acid is mixed in the dispersion, which is inappropriate depending on the application. is there.
[0004]
Accordingly, an object of the present invention is to provide a method for producing a chitosan-containing polymer emulsion having a good dispersion stability and an average particle diameter of 1 μm or less without using a non-polymerizable acid.
[0005]
[Means for Solving the Problems]
The present invention relates to a non-polymerizable acid in which an ethylenically unsaturated monomer is polymerized in the presence of chitosan in which all or part of an amino group has been neutralized with an ethylenically unsaturated monomer having an acid functional group. Is a method for producing a chitosan-containing polymer emulsion having an average particle size of 1 μm or less.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
[Chitosan]
Chitosan used in the present invention is a deacetylated product of chitin having a (1,4) -2-acetamido-2-deoxy-β-D-glucan structure, and (1,4) -2-amino-2. -It has a deoxy- (beta) -D-glucan structure. In general, naturally occurring chitin has a part of an acetamide group as an amino group, and thus chitosan used in the present invention refers to those having a degree of deacetylation of 30% or more. The present invention also includes chitosan derivatives in which part of the amino group or hydroxyl group of chitosan is modified by acylation, esterification, etherification or other reactions. In the present invention, the molecular weight of chitosan is not particularly limited, but preferably about 10,000 to 1,000,000 is used.
[0007]
[Ethylenically unsaturated monomer having acid functional group]
The ethylenically unsaturated monomer having an acid functional group used in the present invention has at least one reactive unsaturated group and at least one acidic group in the molecule, which can dissolve chitosan into a solution. It is a water-soluble organic acid.
[0008]
Specifically, unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, and itaconic acid; styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meta ) Unsaturated sulfonic acid monomers such as acrylic ester and vinyl sulfonic acid; vinyl phosphate, bis ((meth) acryloyloxyethyl) phosphate, diphenyl-2- (meth) acryloyloxyethyl phosphate, dibutyl-2 Examples thereof include unsaturated phosphoric acid monomers such as-(meth) acryloyloxyethyl phosphate and dioctyl-2- (meth) acryloyloxyethyl phosphate, and one or more of these can be used. Of these, unsaturated carboxylic acid monomers having a relatively low acidity are preferable, and methacrylic acid having a particularly low acidity is most preferable.
[0009]
The polymer emulsion of the present invention neutralizes all or part of the amino groups of chitosan with an ethylenically unsaturated monomer having an acid functional group, and has an ethylenically unsaturated monomer having an acid functional group. From the viewpoint of chitosan solubility and particle stability, the amount of the body used is 1.5 times mol or less, preferably 0.6 to 1.2 times mol, more preferably 0.6 to 1.2 times mol per chitosan amino group. Preferably it is 0.6-1.1 times mole.
[0010]
[Other monomers]
In the polymer emulsion of the present invention, it is preferable to use only an ethylenically unsaturated monomer having an acid functional group as a monomer, but it is copolymerized with an ethylenically unsaturated monomer having an acid functional group. Other possible monomers can also be used.
[0011]
Examples of other copolymerizable monomers include olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride, vinyl fluoride, vinylidene chloride, and vinylidene fluoride; vinyl formate, vinyl acetate, and vinyl propionate. Vinyl esters such as vinyl versatic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid which are esters of acrylic acid or methacrylic acid Hexyl, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, ( (Meth) acrylic acid polyethylene Recall, dimethylaminoethyl (meth) acrylate and quaternized compounds thereof, diethylaminoethyl (meth) acrylate and quaternized compounds thereof; acrylamide, methacrylamide, N, N-dimethyl (meth) acrylamide, N, N- Diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nt-butyl (meth) acrylamide, diacetone (meth) acrylamide, N-cyclohexyl (meth) acrylamide, Nt-octyl (meth) acrylamide, N- Acrylamide or methacrylamide monomers such as methylol (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide and quaternary salts thereof; acrylonitrile, methacrylonitrile; ethyl vinyl ether, butyl vinyl Vinyl ethers such as ether, styrene, styrenic monomers such as α- methylstyrene; butadiene, isoprene, diene monomers such as chloroprene; other, may be used in combination N- vinylpyrrolidone.
[0012]
In the present invention, a polyfunctional monomer may be used. Examples of the polyfunctional monomer include divinylbenzene, tetraallyloxyethane, N, N-methylenebis-acrylamide, and 1,3-butylene glycol. Di (meth) acrylate, 1.5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, N, Nm-phenylene bismaleimide Diallyl phthalate, triallyl cyanurate, ethylene glycol diglycidyl ether (meth) acrylate, and the like. These may be used singly.
[0013]
[Polymerization initiator]
As the polymerization initiator used in the present invention, radical decomposition is initiated in the presence of heat or a reducing substance to initiate addition polymerization of the monomer. Water-soluble peroxodisulfate, peroxide, azo Compounds and the like are generally used. For example, peroxodisulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; peroxides such as hydrogen peroxide and t-butyl hydroperoxide; 2,2′-azobis-2-amidinopropane salt (V— 50), 2,2′-azobis-2-methylbutanamide oxime salt, and 4,4′-azobis-4-cyanopentanoic acid. If necessary, it can be used as a redox initiator in combination with a reducing agent. The amount of the polymerization initiator used is preferably in the range of 0.05 to 25% by weight based on the polymerizable monomer.
[0014]
[Other ingredients]
In the polymerization of the present invention, a water-soluble polymer compound other than chitosan and a surfactant can be used in combination as appropriate. The water-soluble polymer compound and the surfactant are not particularly limited as long as they do not hinder the dispersion stability of the polymer generated by the dissolution and polymerization of chitosan. For example, water-soluble polymer compounds include nonionic water-soluble polymer compounds such as polyvinyl alcohol, starch, hydroxymethyl cellulose, hydroxyethyl cellulose, pullulan, and polyethylene oxide, and derivatives obtained by introducing a hydrophobic group, a cationic group, or the like into these. One or more of these can be used, and the total amount used is preferably 50% by weight or less based on chitosan.
[0015]
Examples of the surfactant include anionic surfactants such as dodecyl sulfate, polyoxyethylene dodecyl ether sulfate, dodecyl phosphate, and dodecyl benzene sulfonate; cationic surfactants such as octadecyl trimethyl ammonium salt; poly Nonionic surfactants such as oxyethylene dodecyl ether, sorbitan monostearate, polyoxyethylene sorbitan monostearate, and dodecyl polyglucoside can be used, and one or more of these can be used, and the total amount used is It is preferably 10% by weight or less based on the solvent. It is also possible to use chain transfer agents, terminators and the like.
[0016]
In the production method of the present invention, water is preferably used as a solvent, but a hydrophilic or hydrophobic solvent can be used in combination as appropriate. These may be removed by operations such as distillation under reduced pressure at the end of the polymerization, or may be contained in the product as they are. Examples of the hydrophilic or hydrophobic solvent include hydrocarbons such as pentane, hexane, heptane, cyclohexane and paraffin; alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone, methyl ethyl ketone and diethyl ketone; glycerin, Examples include polyols such as propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and carbitol; esters such as ethyl acetate and methyl acetate; and other dioxanes, acetonitrile, and tetrahydrofuran. One or more of these can be used, and the total amount used is preferably 30 parts by weight or less, more preferably 10 parts by weight or less, with respect to 100 parts by weight of water.
[0017]
In the production method of the present invention, a non-polymerizable acid is not used. Here, non-polymerizable acids are inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid; formic acid, acetic acid, propionic acid, butyric acid, valeric acid, oxalic acid, lactic acid, tartaric acid, succinic acid, malic acid, citric acid, glycol An organic acid such as acid, dichloroacetic acid and trifluoroacetic acid.
[0018]
[Synthesis method]
In the production of the polymer emulsion of the present invention, chitosan and an ethylenically unsaturated monomer having an acid functional group are first dissolved in a solvent, mainly water, and other monomers are optionally added. Furthermore, a polymerization initiator, if necessary, a water-soluble polymer compound, a surfactant, and a chain transfer agent are added to this aqueous solution, and polymerization is performed at a temperature of 30 to 80 ° C. for 1 to 24 hours with stirring. To obtain a polymer emulsion. The polymerization initiator may be added to the system after raising the temperature.
[0019]
The average particle size of the polymer emulsion obtained by the production method of the present invention is 1 μm or less, preferably 0.2 μm or less, more preferably 0.1 μm or less from the viewpoint of storage stability. In addition, in this invention, the average particle diameter was calculated | required by measuring using a laser diffraction type particle size distribution measuring apparatus (LA-910, Horiba, Ltd. make).
[0020]
The polymer emulsion obtained by the production method of the present invention can be neutralized with a base. Examples of the base include ammonia, methylamine, ethylamine, alkanolamine having 2 to 9 carbon atoms, ethylenediamine, amino-modified silicone, sodium hydroxide, potassium hydroxide, calcium hydroxide, and other alkali metals or alkaline earth metals. Products, sodium carbonate, sodium alkoxide, potassium alkoxide, alkyl or alkenyl ammonium having 1 to 22 carbon atoms, alkyl or alkenyl substituted pyridinium having 1 to 18 carbon atoms, tertiary amine, imidazoline, basic amino acid and the like. The amount of the base added is preferably 0.1 to 2.0 moles relative to the acid functional group of the acidic polymer.
[0021]
【The invention's effect】
The polymer emulsion obtained by the production method of the present invention is a polymer emulsion in which chitosan is present on the particle surface or the particle surface and inside, and the chitosan-containing polymer is applied or immersed in paper, fiber or the like. Can remain. Moreover, it can be blended in cosmetics and clothing treatment agents, and since it has a small particle size, it can also be used as a transparent system and has high stability.
[0022]
Since the production method of the present invention does not use a non-polymerizable acid, it can be produced at a low cost, and when blended in cosmetics, the acid and its salts do not elute, so the safety is also improved. high.
[0023]
【Example】
Example 1
Commercially available flaky chitosan (SK-10; manufactured by Koyo Chemical Co., Ltd., deacetylation degree 85% or more, viscosity 10 mPa · m; 1% acetic acid solution / 20 ° C.) 7.50 g and acrylic acid 1.14 g (on the chitosan amino group) 0.45 times mol) and 1.37 g of methacrylic acid (0.45 times mol to the amino group of chitosan) were added, and ion-exchanged water was further added to make 390 g. This is dissolved while stirring at room temperature to prepare a chitosan / acrylic acid / methacrylic acid aqueous solution, transferred to a reflux polymerization tube, a thermometer, a stirring blade, and a glass polymerization vessel equipped with a nitrogen blowing port. The liquid temperature was raised to 70 ° C. while heating. A polymer prepared by dissolving 0.3 g of 2,2′-azobis-2-amidinopropane dihydrochloride (V-50; manufactured by Wako Pure Chemical Industries, Ltd.) in 10 g of ion-exchanged water was added and polymerized for 4 hours. An emulsion was obtained.
[0024]
A small amount of negative staining agent is added to the obtained polymer emulsion, diluted with ion exchange water, and a small amount thereof is dried on a support film for a transmission electron microscope (TEM), and TEM (JEM-2000FX (manufactured by JEOL)) Were observed, spherical fine particles of 100 nm or less were confirmed. A TEM photograph is shown in FIG.
[0025]
Example 2
In Example 1, chitosan was 7.5 g of P (VL) (manufactured by Dainichi Seika Kogyo Co., Ltd., deacetylation degree 80% or more, viscosity 8 mPa · m; 1% acetic acid solution / 20 ° C.). A polymer emulsion was obtained.
[0026]
Example 3
A chitosan / acrylic acid / methacrylic acid aqueous solution was prepared in the same manner as in Example 1 except that 1.0 g of polyvinyl alcohol (PVA) (Gosenol EG-30; manufactured by Nippon Synthetic Chemical Industry, partially saponified type) was added. A polymer emulsion was obtained in the same manner as in Example 1.
[0027]
Example 4
A polymer emulsion was obtained in the same manner as in Example 1 except that acrylic acid was not used in Example 1 and the amount of methacrylic acid was 2.73 g (0.90 times mol with respect to the amino group of chitosan).
[0028]
Example 5
A polymer emulsion was obtained in the same manner as in Example 4 except that the amount of chitosan was 6.0 g and the amount of methacrylic acid was 3.63 g (1.50 mol per mol of the amino group of chitosan) in Example 4. .
[0029]
Comparative Example A polymer emulsion was prepared in the same manner as in Example 4 except that the amount of chitosan was 5.8 g and the amount of methacrylic acid was 4.22 g (1.80 mol per mol of chitosan amino group). Obtained.
[0030]
Test Examples For the polymer emulsions obtained in Examples 1 to 5 and Comparative Example, the average particle diameter and stability during storage were evaluated by the following methods. The results are shown in Table 1.
[0031]
<Evaluation method>
Measurement was performed with an average particle size laser diffraction type particle size distribution measuring device (LA-910, manufactured by Horiba, Ltd.).
[0032]
-Stable storage during storage The dispersion state of the particles (creaming, aggregation, etc.) when the polymer emulsion was allowed to stand at 40 ° C for 1 month was visually observed.
[0033]
[Table 1]

[Brief description of the drawings]
1 is a TEM photograph of the polymer emulsion obtained in Example 1. FIG.

Claims (2)

In the presence of chitosan, where all or part of the amino group is neutralized with an ethylenically unsaturated monomer having an acid functional group, only the ethylenically unsaturated monomer having an acid functional group is used as the monomer. polymerizing and do not use non-polymerizable acids, to a process for the preparation of a mean particle diameter of 1μm or less of the chitosan-containing polymer emulsion, in terms of per amino group of chitosan, ethylenic with acid functionality not The manufacturing method whose usage-amount of a saturated monomer is 1.5 times mole or less . The method for producing a polymer emulsion according to claim 1, wherein the polymer emulsion is polymerized together with the water-soluble polymer compound .

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