JPH07110892B2 - Process for producing copolymer of starch derivative and acrylamide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is to introduce a glycol compound into starch to increase its solubility in water, enhance its characteristics as a lyophilic colloid, and enhance its use as a water-soluble polymer substance. Further, by graft-polymerizing acrylamide to this starch alkyl diol derivative, a product having a remarkably large solution viscosity can be obtained. Since this product has a structural viscosity peculiar to the graft copolymer, its use is further expanded. Current,
In the field of pharmaceutical preparations, water-soluble polymer compounds have an important role, and by utilizing their characteristics such as dispersibility in water, thickening property, and caking property, for example, emulsions,
Used for tablets, syrups, extracts, ointments, poultices, etc. It is also noted that due to its structural viscosity, highly viscous liquids having these structural viscosities in the field of ophthalmology have recently been used to control corneal hydration. That is, it has corneal thickness and cleanliness and protects corneal epithelium and corneal endothelium during intraocular surgery such as vitreous incision. These are also useful as a cleaning agent for contact lenses and as a lubricant. Alkyl diol derivatives of starch have been invented for these uses. This starch derivative can be obtained by dissolving or dispersing starch in an aqueous solution or an organic solvent such as acetone or alcohol and reacting it with a halogenated alkyldiol in the presence of an alkali such as caustic soda. The starch used here may be potato, corn, corn or the like. The Examples of the halogenated alkyl diols used herein, the general formula _{C n + 2 H 2n + 5} O 2, or _{XC n H 2n + 1 C 2} H 2 (OH) 2
, Where n means an integer from 0 to 7,
X is F. It means halogen substances such as Cl, Br and I.
Specifically, 3-chloro-1,2-propanediol, 3
-Bromo-1,2-propanediol, 3-iodo-
1,2-propanediol, 1-chloro-2,3-butanediol and the like. The halogen X reacts with the H atom of the hydroxyl group of starch, and the glycol compound forms an ether bond with starch. The starch derivative in which the glycol compound is introduced has much higher reactivity with respect to the tetravalent cerium salt as compared with the raw starch. Therefore, the starch derivative introduced with the glycol compound easily reacts with the tetravalent cerium salt to generate a radical. Therefore, acrylamide is easily polymerized to obtain a graft copolymer. The starch derivative acrylamide graft copolymer, which is soluble in water and has a much higher viscosity than the starting starch derivative, and a structural viscosity, are more suitable for the above-mentioned applications.

Example 1 Commercially available cornstarch (National Starch and
Chemical Co., Ltd.) 5 g was dispersed in 100 ml of t-butanol,
Stir well in a glass flask equipped with a thermometer, reflux condenser, and glass stirring rod. 30%
20 ml of a caustic soda solution and 10 g of 3-chloro-1,2-propanediol are added in this order to start the reaction. Reaction temperature is 70
The reaction time was 2 hours at ℃. After the reaction, neutralize with concentrated hydrochloric acid, filter the resulting slurry, and add 100 ml of 80% methanol.
And then in 100 ml of anhydrous methanol,
Then, the product was dried under reduced pressure at 60 ° C. overnight to obtain 4 g of a product. The degree of substitution measured by the anthrone method was 0.85 (mol / AGU). The intrinsic viscosity [η] of water at 25 ° C was 0.32 (dl / g). Figure 1 shows the resulting propanediol starch (PDO-
It is an infrared absorption spectrum of starch. At 2960 cm ^-1 , absorption of νC-H due to the propanediol group is observed. AGU is an abbreviation for anhydroglucose unit.

Example 2 0.9 g of PDO-starch of Example 1 was dissolved in 55 ml of distilled water,
Next, 2.7 g of acrylamide previously purified by a recrystallization method from chloroform was added, the air in the reaction solution and the reaction vessel was sufficiently replaced with nitrogen gas, and the mixture was stirred with stirring at 0.
Cerium ammonium nitrate 34.5 dissolved in 10 ml of 1N nitric acid
Add mg to start the reaction. The reaction is carried out for 3 hours, and after standing for 3 hours, 20 mg of hydroquinone is added to stop the reaction. Acetone 400 ml was added to the reaction solution, the precipitate was separated and separated, washed with 20 ml of anhydrous methanol, and dried under reduced pressure at 50 ° C. overnight to obtain 2.1 g of a product. The polymerization rate was 44%, and the intrinsic viscosity [η] at 25 ° C in water was 2.5 (dl / g). The infrared absorption spectrum (KBr method) shows that the absorption of νN—H at 2960 cm ⁻¹ due to acrylamide is 1670 cm ^−1.
ΝC = 0 absorption, and absorption of 1050 cm ^-1 pyranose ring due to starch can be observed. These PDO-starch and PDO-starch-acrylamide graft copolymers are novel substances, respectively.

Example 3 6 g of commercially available cornstarch white dextrin (manufactured by National Starch and Chemical Co.) was used, and the same operation as in Example 1 was performed except that the slurry was evaporated to dryness when the slurry was separated from the reaction solution. 8.1 g of PDO-starch was obtained.

The intrinsic viscosity at 25 ° C in water was 0.31 (dl / g).

Example 4 The same procedure as in Example 1 was repeated except that 15 g of 1-bromo-2,3-butanediol was reacted with commercially available Constarch (manufactured by National Starch and Chemical Co.), and the substitution degree of butanediol was 0.7 ( 5 g of butanediol (BDO) -starch (mol / AGU) was obtained. The intrinsic viscosity [η] of water at 25 ° C was 0.38 (dl / g).

Example 5 Acid Corn Cornwax Waxy Corn Starch
Bow 2 g of 30% caustic soda solution, let stand for 2 hours, press to 6 g to squeeze extra caustic soda solution, and dry under vacuum at room temperature for 3 days.
Disperse in 80 ml, and in a three glass flask equipped with a thermometer, a reflux condenser and a glass stirring rod,
-React the reaction solution with 5 ml of chloro-1,2-propanediol under reflux. The reaction was carried out for 3 hours, and the subsequent operation was carried out in the same manner as in Example 1 to obtain 1.4 g of PDO-starch.
The intrinsic viscosity [η] of water at 25 ° C was 0.6 (dl / g). The infrared absorption spectrum (KBr method) has 1,2-
Absorption of νC-H due to propanediol group is 2960 cm
^-1 Observed in the vicinity.

Example 6 Except for using 2 g of commercially available potato starch, the same operation as in Example 5 was repeated to obtain the degree of substitution of propanediol (0.8 mol / mol).
ADO) 1.6 g of PDO-starch was obtained, and the intrinsic viscosity [η] at 25 ° C of water was 0.8 (dl / g).

Example 7 The procedure of Example 2 was repeated, except that the PDO-starch of Example 6 was used, to obtain 2.4 g of a PDO-starch-acrylamide graft copolymer. The polymerization rate was 55%, and the intrinsic viscosity [η] of water at 25 ° C was 3.3 (dl / g).

When 2 g of this solution was dissolved in 31 ml of distilled water together with 0.3 g of sodium chloride to prepare a solution, which was used for washing the inner surface of the eye of a patient undergoing intraocular lens transplantation, good results were obtained. It was used topically 8 times daily for 2 weeks after surgery, and the occurrence of corneal complications was less than that of the conventional method.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum of PDO-starch of Example 1 by the KBr method.

Claims (1)

[Claims] 1. A process for producing a copolymer, characterized in that acrylamide is polymerized with an alkyldiol derivative of starch obtained by reacting starch with a halogenated alkyldiol in the presence of an alkali.