JP3181742B2 - Method for producing chitosan-containing polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new method for producing a chitosan-containing polymer.

[0002]

2. Description of the Related Art Chitosan is a basic polysaccharide obtained by treating a chitin present in the shell of crustaceans such as crabs and shrimps with a concentrated alkali and deacetylating it.
It is a natural polymer having unique properties such as water absorption and moisture permeability and biocompatibility. It is very useful in many fields to incorporate such chitosan into various polymers to impart the properties of chitosan to the polymer as described above. In such a chitosan-containing polymer containing chitosan as a polymer, it is important that chitosan is uniformly dispersed in the polymer in order to provide a product of constant quality.

[0003] In general, such a chitosan-containing polymer has been produced by pulverizing chitosan and then mixing it with the polymer. Further, fine particles of chitosan are disclosed in JP-A-62-62827, JP-A-62-288601, and JP-A-62-288602.
JP-A-63-17901, JP-A-63-17901
17902, JP-A-63-20302, JP-A-63-210101, JP-A-63-21010
No. 2, JP-A-64-66204. However, the chitosan-containing polymer obtained by the conventional method has insufficient uniform dispersion of the chitosan in the polymer, and products manufactured using such a chitosan-containing polymer have properties of a certain quality of chitosan. Things are hard to obtain.

[0004]

An object of the present invention is to provide a method for producing a chitosan-containing polymer in which chitosan is more uniformly dispersed in a polymer without using a method of mixing finely divided chitosan with a polymer. .

[0005]

This problem is solved by a method of salting out a polymer emulsion using an aqueous solution of chitosan acid.

Hereinafter, the present invention will be described in detail. The chitosan acid aqueous solution used in the present invention is obtained by dissolving chitosan in acidic water. The chitosan used here is (1 → 4) -2-acetamido-2-deoxy-β
A deacetylated product of chitin having a -D glucan structure, comprising (1 → 4) -2-amino-2-deoxy-β-D
In the present invention, a part of a deacetylated amino group or a part of a hydroxyl group in the same molecule is chemically modified by an acylation reaction, an etherification reaction, an esterification reaction, or another reaction. Also included are chitosan derivatives.

[0007] The type of acid used for dissolving chitosan is not particularly limited, as long as it does not cause any problem in performing salting out. Specific examples include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, and propionic acid. The mixing ratio of acid and water to chitosan is an arbitrary ratio equal to or higher than the minimum ratio in which chitosan can be completely dissolved.

[0008] The polymer emulsion referred to in the present invention is an acrylic emulsion, a vinyl acetate emulsion, a styrene emulsion, a vinyl chloride emulsion, a butadiene emulsion, a copolymer emulsion thereof, and a polymer emulsion obtained by an emulsion polymerization method. Emulsion, and one or two or more polymer emulsions are appropriately selected from these depending on the purpose, regardless of the type of polymer.

As an example of an operation for salting out such a polymer emulsion with an aqueous solution of chitosan acid, the polymer emulsion is diluted with water or the like as necessary,
Heat to ~ 95 ° C. Then, the above-mentioned aqueous solution of chitosan acid was added dropwise to the heated polymer emulsion.
After holding at 0 to 95 ° C for 1 to 3 hours, the mixture is cooled. In this case, a polymer is precipitated. Next, the precipitated polymer is taken out, washed with water until neutral, and dried to obtain a chitosan-containing polymer in which chitosan is uniformly dispersed in the polymer. In this salting-out operation, the chitosan acid aqueous solution alone may be used, or another salting-out agent may be used in combination. As other salting-out agents, calcium chloride, aluminum sulfate, sodium chloride, magnesium chloride, magnesium sulfate, magnesium chloride and the like can be used.

In the method for producing a chitosan-containing polymer of the present invention, since the polymer emulsion is salted out using an aqueous solution of chitosan acid, the chitosan is uniformly dispersed in the polymer without using a method of mixing finely divided chitosan with the polymer. Thus, a chitosan-containing polymer can be obtained. Therefore, when a target product is produced using the chitosan-containing polymer obtained by the method for producing a chitosan-containing polymer of the present invention, there is an advantage that a product having chitosan characteristics of a constant quality is easily obtained.

[0011]

The present invention will be specifically described below with reference to examples. (Reference example) 2L, 4-neck flask with ion-exchanged water 600
g, 1 g of sodium phosphate monobasic was charged, deoxygenated with nitrogen gas, and heated to 50 ° C. with stirring. A pre-emulsion having the following composition and an aqueous solution of sodium hydrogen sulfate (202 g, sodium hydrogen sulfate / ion-exchanged water = 2/200) were added thereto, and the temperature inside the flask was set to 49 to 51.
The polymerization reaction was carried out dropwise over 3 hours while maintaining the temperature at ° C., and an aging reaction was carried out at the same temperature for 2 hours to obtain an acrylic emulsion.

[Pre-emulsion composition] Butyl acrylate 400 g Ethyl acrylate 130 g Acrylonitrile 60 g 2-hydroxyethyl methacrylate 10 g Dodecyl mercaptan 0.08 g Emulsifier (Emulgen 106 manufactured by Kao Corporation) 6 g Emulsifier (Emal 2F manufactured by Kao Corporation) 2.4 g 2.4 g of calcium sulfate 200 g of ion-exchanged water

(Example 1) 360 g of the acrylic emulsion of the reference example was diluted with 1080 g of water, and this was diluted with 8 g of water while stirring.
The temperature was raised to 0 ° C. 50 g of an aqueous solution of chitosan acid having the following composition was added dropwise thereto over 5 minutes, and the mixture was kept at 80 ° C. for 1 hour. After cooling, the precipitated polymer was taken out, washed thoroughly with water until it became neutral, and dried. Thus, 128.63 g of a yellow chitosan-containing polymer was obtained. When this dried polymer was made into a 15% toluene solution, a yellow transparent solution was obtained, and it was confirmed that chitosan was uniformly dispersed.
In addition, a chitosan-containing acrylic film was prepared from the solution by a casting method, and the antibacterial property of this film was examined by a bacterial count method. As a result, the difference in the bacterial count after washing 10 times was 4.5.
And an antibacterial effect was recognized.

[Chitosan acid aqueous solution] chitosan 30 g acetic acid 30 g water 500 g

Example 2 50 g of an aqueous chitosan acid solution having the same composition as in Example 1 was diluted with 1080 g of water,
The temperature was raised to 0 ° C., 360 g of the emulsion of Reference Example was added dropwise over 15 minutes with stirring, and further kept at 80 ° C. for 1 hour, cooled to room temperature, and the precipitated polymer was separated and neutralized until neutral. And dried to obtain 127.5 g of a yellow chitosan-containing polymer. 15% of this dried polymer
When converted to a toluene solution, a yellow transparent solution was obtained, and it was confirmed that chitosan was uniformly dispersed. In addition, a chitosan-containing acrylic film was prepared from the solution by a casting method, and the antibacterial property of this film was examined by a bacterial count method. Was.

(Comparative Example) 10 g of aluminum sulfate was dissolved in 1080 g of water, the temperature of the solution was raised to 80 ° C., 360 g of the emulsion of Reference Example was added dropwise with stirring for 15 minutes, and the mixture was kept at 80 ° C. for 1 hour. After cooling to room temperature, the precipitated polymer was separated, thoroughly washed with water until neutral, and dried to obtain 126.5 g of a white polymer. When this dried polymer was made into a 15% toluene solution, a yellow transparent solution was obtained. In addition, an acrylic film was prepared from this solution by a casting method, and the antibacterial property of this film was examined by a bacterial count method. Was.

[0017]

As described above, according to the method for producing a chitosan-containing polymer of the present invention, since a polymer emulsion is salted out using an aqueous solution of chitosan acid, a method of mixing finely divided chitosan with a polymer can be used. It is possible to obtain a chitosan-containing polymer in which chitosan is more uniformly dispersed in the polymer. Therefore, when a target product is produced using the chitosan-containing polymer obtained by the method for producing a chitosan-containing polymer of the present invention, there is an advantage that a product having chitosan characteristics of a constant quality is easily obtained.

Claims (1)

(57) [Claims] 1. A method for producing a chitosan-containing polymer, comprising salting out a polymer emulsion using an aqueous solution of chitosan acid.