JP2619304C

JP2619304C -

Info

Publication number: JP2619304C
Authority: JP
Original assignee: Dainichiseika Color and Chemicals Mfg Co Ltd
Current assignee: Dainichiseika Color and Chemicals Mfg Co Ltd
Publication date: 1999-02-10

Description

【発明の詳細な説明】【０００１】【産業上の利用分野】本発明は特別な圧力容器や触媒を必要とせず、且つ反応媒体として水のみを使
用する、極めて簡便で工業上利用価値の高いヒドロキシプロピル化脱アセチル化
キチンの製造方法に関する。【０００２】【従来の技術】ヒドロキシプロピル化多糖は多糖の水溶性誘導体として重要なものの一つであ
り、ヒドロキシプロピル化セルロースが既に広く実用されていることは周知の通
りである。又、例えば、ヒドロキシプロピル化多糖の一種であるヒドロキシプロ
ピル化脱アセチル化キチンは、特公昭６４−５６０１号公報に記載されている様
に化粧品原料等各種用途に有用な水溶性高分子である。従来、このヒドロキシプロピル化脱アセチル化キチンの製造に当たっては、上
記公報にも記載されている様に水酸化ナトリウム等の強アルカリ触媒を必須成分
とし、加圧下、有機溶媒系でヒドロキシプロピル化を行っていた。【０００３】【発明が解決しようとしている課題】しかしながら、言うまでもなく加圧下で反応を行う為には圧力容器が必要であ
り、種々の制約並びに危険を伴うという問題がある。又、有機溶剤の使用につい
ても、火災に対する危険性或は製品への残留等の問題がある。強アルカリ触媒の
使用についても、その除去に多大の労力を必要とするという問題がある。【０００４】又、ヒドロキシプロピル化脱アセチル化キチンは酵素の活性測定用基剤として
重要なものであるが、このものの製造方法として脱アセチル化キチンのヒドロキ
シプロピル化を常圧下、水を溶媒として行うことが行われている。しかし、この
場合も、触媒として水酸化ナトリウムを使用することが必須であり、同様の問題
を包含している。従って、本発明の目的は、上記の従来技術の問題点を解決し、常圧下、無触媒
で、且つ有機溶媒系を使用することなくヒドロキシプロピル化脱アセチル化キチ
ンを簡便に製造し得る方法を提供することにある。【０００５】【課題を解決するための手段】上記の目的は、下記の本発明により達成される。即ち、本発明は、脱アセチル化キチンを水を反応媒体とし、常圧下、無触媒で
プロピレンオキサイドを用いてヒドロキシプロピル化するに際し、プロピレンオ
キサイドを少なくとも２段階で反応させることを特徴とするヒドロキシプロピル
化脱アセチル化キチンの製造方法。。【０００６】【作用】本発明者らは、簡便なヒドロキシプロピル化多糖の製造方法について鋭意研究
した結果、脱アセチル化キチンを出発物質とすれば、水を反応媒体として、常圧
下、しかも触媒を添加することなく容易に水溶性のヒドロキシプロピル化脱アセ
チル化キチンが得られることを見い出し、本発明を完成した。【０００７】【好ましい実施態様】本発明に於いて使用する脱アセチル化キチンとは、カニ、エビ、昆虫等の甲殻
類或は茸等に含まれている天然高分子の一種であり、２−アミノ−２−デオキシ
−Ｄ−グルコースを一構成単位とする塩基性脱アセチル化キチン類である。この
様な脱アセチル化キチンそれ自体は既に工業的に生産されており、種々のグレー
ドのものが市場から入手出来る。これらの公知の脱アセチル化キチンはいずれも本発明で使用することが出来る
。例えば、本発明方法で製造する最終生成物の用途に応じて、増粘剤として使用
するものを製造する場合には比較的高粘度の脱アセチル化キチンを使用し、一方
、コーティング剤として使用するものを製造する場合には比較的低重合度の脱ア
セチル化キチンを出発物質に使用すればよい。【０００８】又、脱アセチル化度についても特に制限はないが、本発明に於いて好適な脱ア
セチル化度は５０〜１００％である。この様な脱アセチル化キチンのヒドロキシプロピル化は、反応当初は分散系で
行う。この際の反応媒体は水のみでよく、分散濃度は特に限定されないが、水媒
体１００重量部あたり、約５〜２０重量部程度とするのが好ましい。又、ヒドロキシプロピル化反応に使用するプロピレンオキサイドの量は、脱ア
セチル化キチン１００重量部あたり、約１００〜８００重量部が好ましい。又、
その際の反応時間は反応温度にもよるが、１０〜５０時間程度とし、この間に徐
々に昇温して、系の沸点程度の温度で反応を行うのが好ましい。【０００９】次に実施例を挙げて本発明を更に具体的に説明する。【実施例】実施例１先ず、脱アセチル化度８２％の脱アセチル化キチン９ｇをイオン交換水１２０
ｇ中に分散した。次にこれにプロピレンオキサイド４．５ｇを加えて、撹拌しな
がら１時間３０分かけて８５．５℃まで加温した。この状態で反応を３時間続け
た後、液温が９４．５℃になったところで一旦室温まで冷却した。これに更にプ
ロピレンオキサイド４．５ｇを加えた後、更に沸点で２時間反応を行った。反応終了後、冷却静置し、上澄み液をデカントした。次に、大過剰のイソプロ
ピルアルコールを加えて撹拌し濾過した後、更にイソプロピルアルコールで濾過
物を洗浄した。これを５０℃にて乾燥後、目的のヒドロキシプロピル化脱アセチル化キチン１２ｇを得た。このものはそのままでは水に不溶性であるが、少量の酢酸を加えることにより
溶解し、その後は水酸化ナトリウムによって中和しても析出することなく均一な
水溶液の状態を保持した。【００１０】実施例２先ず、脱アセチル化度７０％の脱アセチル化キチン９ｇをイオン交換水１２０
ｇに分散した。次にこれにプロピレンオキサイド９ｇを加え、撹拌しながら１時
間３０分かけて６５．０℃まで加温した。この状態で反応を５時間続けた後、液
温が８２℃になったところで一旦室温まで冷却した。これに更にプロピレンオキ
サイド９ｇを加えた後、更に５６℃で４時間反応を行った。反応終了後、冷却静置し、上澄み液をデカントした。次に、大過剰のイソプロ
ピルアルコールを加えて撹拌し濾過した後、更にイソプロピルアルコールで濾過
物を洗浄した。これを５０℃にて乾燥後、目的のヒドロキシプロピル化脱アセチル化キチン１
３ｇを得た。このものはそのままでは水に不溶性であるが、少量の酢酸を加えることによっ
て溶解し、その後は水酸化ナトリウムによって中和しても析出することなく均一
な水溶液の状態を保持した。【００１１】実施例３先ず、脱アセチル化度８２％の脱アセチル化キチン９ｇをイオン交換水１２０
ｇに分散した。次にこれにプロピレンオキサイド１２ｇを加え、撹拌しながら１
時間３０分かけて５７℃まで加温した。この状態で反応を５時間続け、液温が８
４℃になったところで一旦室温まで冷却した。これに更にプロピレンオキサイド
１２ｇを加えた後、更に沸点で７時間反応を行った。冷却後、プロピレンオキサ
イドを更に１３ｇを加え、更に沸点で７時間反応を行った。この間に脱アセチル
化キチンが膨潤を始め、反応系の粘度が著しく増大した。更にプロピレンオキサイド１１ｇを加え、沸点で７時間反応を行ったところ、大部分のヒドロキシプロピル化脱アセチル化キチンは反応系中に溶解した。反応
液をグラスフィルターにて濾過して少量の不溶解物を除き、目的のヒドロキシプ
ロピル化脱アセチル化キチン水溶液を得た。【００１２】【発明の効果】以上の通り本発明によれば、圧力容器、有機溶剤、強アルカリ触媒を必要とせ
ず、火災に対する危険性或は製品への溶剤の残留の問題がなく、又、触媒除去の
多大な労力を要せずに、水を反応媒体とし、常圧下、無触媒下で反応して簡便に
ヒドロキシプロピル化脱アセチル化キチンを製造出来る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not require a special pressure vessel or catalyst, and uses only water as a reaction medium. The present invention relates to a method for producing hydroxypropylated deacetylated chitin. [0002] Hydroxypropylated polysaccharides are one of important water-soluble derivatives of polysaccharides, and it is well known that hydroxypropylated cellulose is already widely used. Further, for example, hydroxypropylated deacetylated chitin, which is a kind of hydroxypropylated polysaccharide, is a water-soluble polymer useful for various uses such as a raw material for cosmetics, as described in JP-B-64-5601. Conventionally, in producing this hydroxypropylated deacetylated chitin, a strong alkali catalyst such as sodium hydroxide is used as an essential component as described in the above publication, and hydroxypropylation is carried out under pressure and in an organic solvent system. I was [0003] However, needless to say, in order to carry out the reaction under pressure, a pressure vessel is required, and there is a problem that various restrictions and dangers are involved. In addition, the use of an organic solvent also poses problems such as danger to fire and remaining in products. There is also a problem that the use of a strong alkali catalyst requires a great deal of labor to remove it. [0004] Also, hydroxypropylated deacetylated chitin is important as a base for measuring the activity of an enzyme, and as a production method thereof, hydroxypropylation of deacetylated chitin is carried out under normal pressure and using water as a solvent. That is being done. However, also in this case, it is essential to use sodium hydroxide as a catalyst, which involves the same problem. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for easily producing hydroxypropylated deacetylated chitin without using a catalyst under normal pressure and without using an organic solvent system. To provide. [0005] The above object is achieved by the present invention described below. That is, the present invention uses deacetylated chitin with water as a reaction medium, under normal pressure, without a catalyst.
Upon that hydroxypropylated with propylene oxide, propylene Oh
A method for producing hydroxypropylated deacetylated chitin , comprising reacting a sulfide in at least two steps . . The present inventors have conducted intensive studies on a simple method for producing a hydroxypropylated polysaccharide. As a result, when deacetylated chitin was used as a starting material, water was used as a reaction medium under normal pressure, and a catalyst was obtained. It has been found that a water-soluble hydroxypropylated deacetylated chitin can be easily obtained without addition, and the present invention has been completed. A preferred embodiment of the present invention is a deacetylated chitin used in the present invention, which is a kind of natural polymer contained in crustaceans such as crabs, shrimps, and insects or mushrooms. Basic deacetylated chitins containing amino-2-deoxy-D-glucose as a constituent unit. Such deacetylated chitin itself has already been industrially produced and various grades are available on the market. Any of these known deacetylated chitins can be used in the present invention. For example, depending on the use of the final product produced by the method of the present invention, a relatively high-viscosity deacetylated chitin is used when producing a substance to be used as a thickener, while a coating agent is used. In the case of producing the same, deacetylated chitin having a relatively low degree of polymerization may be used as a starting material. The degree of deacetylation is not particularly limited, but the preferred degree of deacetylation in the present invention is 50 to 100%. Such hydroxypropylation of deacetylated chitin is performed in a dispersion system at the beginning of the reaction. The reaction medium at this time may be water alone, and the dispersion concentration is not particularly limited, but is preferably about 5 to 20 parts by weight per 100 parts by weight of the aqueous medium. The amount of propylene oxide used for the hydroxypropylation reaction is preferably about 100 to 800 parts by weight per 100 parts by weight of deacetylated chitin. or,
The reaction time at that time depends on the reaction temperature, but it is preferably about 10 to 50 hours, during which the temperature is gradually raised and the reaction is preferably carried out at a temperature about the boiling point of the system. Next, the present invention will be described more specifically with reference to examples. EXAMPLES Example 1 First, 9 g of deacetylated chitin having a degree of deacetylation of 82% was mixed with 120 g of ion-exchanged water.
g. Next, propylene oxide (4.5 g) was added thereto, and the mixture was heated to 85.5 ° C. over 1 hour and 30 minutes with stirring. After continuing the reaction for 3 hours in this state, when the liquid temperature reached 94.5 ° C., the mixture was once cooled to room temperature. After further adding 4.5 g of propylene oxide, the mixture was further reacted at the boiling point for 2 hours. After completion of the reaction, the mixture was allowed to cool, and the supernatant was decanted. Next, a large excess of isopropyl alcohol was added, and the mixture was stirred and filtered, and the filtrate was further washed with isopropyl alcohol. After drying at 50 ° C., 12 g of the desired hydroxypropylated deacetylated chitin was obtained. Although this product was insoluble in water as it was, it was dissolved by adding a small amount of acetic acid, and after that, even when neutralized with sodium hydroxide, it maintained a uniform aqueous solution state without precipitation. Example 2 First, 9 g of deacetylated chitin having a degree of deacetylation of 70% was mixed with deionized water 120
g. Next, 9 g of propylene oxide was added thereto, and the mixture was heated to 65.0 ° C. over 1 hour and 30 minutes with stirring. After the reaction was continued for 5 hours in this state, when the liquid temperature reached 82 ° C., it was once cooled to room temperature. After further adding 9 g of propylene oxide, the reaction was further carried out at 56 ° C. for 4 hours. After completion of the reaction, the mixture was allowed to cool, and the supernatant was decanted. Next, a large excess of isopropyl alcohol was added, and the mixture was stirred and filtered, and the filtrate was further washed with isopropyl alcohol. After drying at 50 ° C., the desired hydroxypropylated deacetylated chitin 1
3 g were obtained. Although this was insoluble in water as it was, it was dissolved by adding a small amount of acetic acid, and after that, even when neutralized with sodium hydroxide, it remained in a uniform aqueous state without precipitation. Example 3 First, 9 g of deacetylated chitin having a degree of deacetylation of 82% was added to ion-exchanged water 120
g. Next, 12 g of propylene oxide was added thereto, and the mixture was stirred for 1 hour.
Heated to 57 ° C. over 30 minutes. In this state, the reaction was continued for 5 hours,
When the temperature reached 4 ° C, it was once cooled to room temperature. After further adding 12 g of propylene oxide, the reaction was further carried out at the boiling point for 7 hours. After cooling, 13 g of propylene oxide was further added, and the reaction was further performed at the boiling point for 7 hours. During this time, the deacetylated chitin began to swell, and the viscosity of the reaction system increased significantly. Further, 11 g of propylene oxide was added, and the reaction was carried out at the boiling point for 7 hours. Most of the hydroxypropylated deacetylated chitin was dissolved in the reaction system. The reaction solution was filtered through a glass filter to remove a small amount of insoluble matter, thereby obtaining a target hydroxypropylated deacetylated chitin aqueous solution. As described above, according to the present invention, there is no need for a pressure vessel, an organic solvent, or a strong alkali catalyst, and there is no danger to fire or a problem of solvent remaining in a product. Hydroxypropylated deacetylated chitin can be easily produced by reacting with water as a reaction medium under normal pressure and without a catalyst without requiring a great deal of labor for catalyst removal.

Claims

The Claims 1. A deacetylated chitin and the reaction medium of water, under normal pressure, up in the absence of a catalyst
Upon that hydroxypropylated with b pyrene oxide, propylene Oki
A method for producing hydroxypropylated deacetylated chitin , comprising reacting the side in at least two steps .