JPH09328537A - Polymer containing l-ascorbic acid segment and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer which is excellent in water resistance and oxygen-reducing capability and is useful as an oxygen absorbent of a deoxidizing material by selecting a specific polymer having L-ascorbic acid segments in the main chain. SOLUTION: This polymer has L-ascorbic acid segments in the main chain and is represented by formula I [wherein n is the degree of polymn.; and R is a residue of a dibasic acid dihalide compd. (pref. a divalent linking group represented by formula II) or a residue of a diisocyanate compd. (pref. a divalent linking group represented by formula III)]. The polymer of which R is a residue of a dibasic acid dihalide can be produced by reacting L-ascorbic acid with a dibasic acid dihalide compd. in the presence of a hydrogen halide scavenger (e.g. pyridine). The polymer of which R is a diisocyanate compd. residue can be produced by reacting L-ascorbic acid with a diisocyanate compd. in the presence of a tin catalyst (e.g. dibutyltin dilaurate).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oxygen-reducing polymer and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, L-ascorbic acid has been used as a main component of an antioxidant or a main component of a deoxidizing material by utilizing its property of reducing oxygen.

By the way, L-ascorbic acid has a problem that it is inferior in handleability due to its extremely high water solubility and its extremely low stability against oxidation.

Therefore, it has been attempted to use an oxygen-absorbing polymer material obtained by kneading L-ascorbic acid in an ethylene-vinyl acetate copolymer (EVA) as a deoxidizing material, but in view of oxygen-absorbing ability. There is a problem that the water resistance and the solvent resistance are insufficient because L-ascorbic acid is not bonded to the polymer chain. Further, there is a concern that L-ascorbic acid may be decomposed by heating during kneading.

Therefore, for the purpose of improving the water resistance and oxidative stability of L-ascorbic acid, it has been attempted to introduce an L-ascorbic acid segment into the polymer chain. As a monomer necessary for producing such an oxygen-reducing polymer having an L-ascorbic acid segment introduced therein, L-ascorbic acid having a polymerizable functional group introduced at the 6-position hydroxyl group of L-ascorbic acid is used. Examples thereof include acid methacrylic acid ester monomers, which are (a) a method of reacting methacrylic acid enol ester and L-ascorbic acid in the presence of lipase, and (b) a methacrylic acid chloride and L-ascorbic acid as a base. Of reacting in the presence of an organic compound, (c) methacrylic anhydride and L-
It has been proposed to produce it by a method of reacting with ascorbic acid in the presence of a basic condensing agent (Japanese Patent Laid-Open No. HEI 5-
331157).

[0006]

However, in the case of the above-mentioned method (a), it is difficult to mass-produce it because the enzyme reaction is used, and in the case of the method (b), the acid chloride used as a raw material is Highly irritating to skin and mucous membranes,
Moreover, it is easily hydrolyzed and has low handleability, and in the case of the method (c), it is difficult to produce the ascorbic acid methacrylic acid ester monomer with high reproducibility due to the influence of oxygen in the reaction system. Therefore, conventionally, it has been required to introduce the L-ascorbic acid unit into the polymer chain by a simple method.

The present invention is intended to solve the above problems of the prior art, and is a polymer in which an L-ascorbic acid unit is introduced into the main chain by a simple method without using an enzyme or an acid chloride. The purpose is to be able to provide.

[0008]

The above-mentioned object can be solved by the present invention described below.

That is, the present invention uses the formula (1)

[0010]

Embedded image (In the formula, n is a number indicating the degree of polymerization, and R is a dibasic acid dihalide compound residue or a diisocyanate compound residue.), And an L-ascorbic acid segment-containing polymer is provided.

The present invention also provides a method for producing a polymer containing an L-ascorbic acid segment, wherein R in the formula (1) is a dibasic acid dihalide compound residue, in the presence of a hydrogen halide scavenger. There is provided a production method characterized by reacting a dibasic acid dihalide compound with an acid.

The present invention also provides a method for producing a polymer containing an L-ascorbic acid segment in which R in the formula (1) is a diisocyanate-based compound residue, in the presence of a tin catalyst, diisocyanate-based L-ascorbic acid. Provided is a production method characterized by allowing a compound to act.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The L-ascorbic acid segment-containing polymer of the formula (1) of the present invention has a main chain partly composed of L-ascorbic acid. Moreover, the hydroxyl group at the 3-position of the L-ascorbic acid segment, which is considered to greatly contribute to the reduction of oxygen, is retained as it is. Therefore, this L-ascorbic acid segment-containing polymer becomes an oxygen-reducing polymer.

In the formula (1), n is a number showing the degree of polymerization, and R is a known dibasic acid dihalide compound residue or diisocyanate compound residue.

The dibasic acid dihalide compound residue of R is represented by the formula (2) or (3)

[0017]

Embedded image The divalent bonding group represented by is preferably mentioned.
Here, the linking group of formula (2) can be derived from sebacoyl dichloride. Also, the linking group of formula (3) can be derived from terephthaloyl dichloride.

The diisocyanate compound residue of R is represented by the formula (4) or (5)

[0019]

[Chemical 6] The divalent bonding group represented by is preferably mentioned.
Here, the diisocyanate-based compound residue of the formula (4) is
It can be derived from isophorone diisocyanate. Also, the linking group of formula (5) can be derived from 1,4-phenylene diisocyanate.

In the formula (1), the L-ascorbic acid segment-containing polymer in which R is a dibasic acid dihalide compound residue can be produced as follows.

First, in the presence of 0.1 to 2.0 molar equivalents of a hydrogen halide scavenger such as pyridine or imidazole with respect to 0.1 mol of L-ascorbic acid, acetone, dimethylformamide or the like may be added, if necessary. Dissolve in protic solvent at 5-30 ° C. Then, 0.01 to 0.2 parts by weight of a dibasic acid dihalide compound (for example, sebacyl dichloride, terephthaloyl dichloride, etc.) is added dropwise to the solution at 0 to 5 ° C. under a nitrogen atmosphere, and 0 at the same temperature. ．
The reaction is carried out for 5 to 2.0 hours, and if necessary, at room temperature for 1 to 6 hours.

After completion of the reaction, the precipitate was collected by filtration, washed repeatedly with water, methanol and acetone in this order, and finally dried under reduced pressure, whereby R in the formula (1) was a dibasic acid dihalide compound residue, L. A polymer containing ascorbic acid segments is obtained.

In the formula (1), an L-ascorbic acid segment-containing polymer in which R is a diisocyanate compound residue can be produced as follows.

First, 100 to 250 ml of an aprotic polar solvent such as dimethylformamide is added to 0.1 mol of L-ascorbic acid and dissolved in a nitrogen atmosphere. In this solution, a diisocyanate compound (for example, isophorone diisocyanate, 1,4-phenylene diisocyanate, etc.) is added to this solution in the presence of 0.1 to 1.5 g of a tin catalyst (for example, tin dibutyl laurate) as a catalyst. Gradually dripping, 2 ~ 8 at a temperature of 40 ~ 80 ° C
React for hours.

After completion of the reaction, the reaction solution was allowed to cool to room temperature and 3
The reaction solution is concentrated under reduced pressure at a temperature of 0 ° C. or lower. The concentrate is dissolved in acetone, and the solution is poured into a large amount of benzene to obtain a precipitate. This precipitate is treated with benzene, n-hexane,
Alternatively, an L-ascorbic acid segment-containing polymer in which R is a diisocyanate-based compound residue in the formula (1) is obtained by washing with ethanol and acetone and drying under reduced pressure.

The L-ascorbic acid segment-containing polymer of the present invention described above is a polymer itself,
Compared with the case where L-ascorbic acid is kneaded into EVA or the like, the water resistance, heat resistance, and moldability are improved.

The L-ascorbic acid segment-containing polymer of the present invention has a good oxygen reducing ability (oxygen absorbing ability) derived from the L-ascorbic acid segment. It can be preferably used as an oxygen absorbing component. There are no particular restrictions on the other components that make up the deoxidizing material, and the deoxidizing material should be constructed according to the conventional composition of the deoxidizing material except that the oxygen-reducing polymer of the present invention is used as the oxygen absorbing component. You can

[0028]

The present invention will be described below in more detail with reference to examples.

Example 1 A flask (200 ml) was charged with pyridine / acetone (2 /
Add 150 ml of the mixed solvent of 1) and add L- under a nitrogen atmosphere.
8.8 g of ascorbic acid was dissolved at room temperature. 12.6 g of sebacoyl dichloride was gradually added dropwise to this solution. After completion of the dropping, the mixture was stirred at 0 to 5 ° C for 1 hour, and further at room temperature for 2 hours.

After completion of the reaction, the precipitate is collected by filtration, washed thoroughly with water, methanol, and acetone in this order, and dried under reduced pressure, whereby R is a sebacyl dichloride residue of the formula (2). The polymer containing the L-ascorbic acid segment of (1) was obtained.

Example 2 A flask (200 ml) was charged with dimethylformamide 15
0 ml was added, and L-ascorbic acid was added under a nitrogen atmosphere.
8 g and imidazole 3.4 g were dissolved at room temperature. 12.6 g of terephthaloyl dichloride was gradually added dropwise to this solution. After completion of the dropping, the mixture was stirred at 0 to 5 ° C for 1 hour, and further at room temperature for 2 hours.

After the completion of the reaction, the precipitate is collected by filtration, washed thoroughly with water, methanol and acetone in this order and dried under reduced pressure, whereby R is a terephthaloyl dichloride residue of the formula (3). An L-ascorbic acid segment-containing polymer of formula (1) was obtained.

Example 3 A flask (300 ml) was charged with dimethylformamide 15
0 ml was added, and L-ascorbic acid was added under a nitrogen atmosphere.
8 g was dissolved at room temperature. To this solution, 0.7 g of tin dibutyl laurate as a catalyst was added, and then a solution of 4.9 g of isophorone diisocyanate dissolved in 50 ml of dimethylformamide was gradually added. After the dropping was completed, the temperature of the reaction solution was raised to 50 to 60 ° C. and the reaction was carried out for about 5 hours.

After completion of the reaction, the reaction solution was allowed to cool to room temperature and then 3
The mixture was concentrated under reduced pressure at a temperature of 0 ° C. or lower, the concentrate was dissolved in acetone, and the solution was poured into a large amount of benzene to generate a precipitate. The obtained precipitate was thoroughly washed with benzene and n-hexane in that order, and dried under reduced pressure to obtain R
An L-ascorbic acid segment-containing polymer of the formula (1) was obtained in which is an isophorone diisocyanate residue of the formula (4).

Example 4 A flask (300 ml) was charged with dimethylformamide 15
0 ml was added, and L-ascorbic acid was added under a nitrogen atmosphere.
8 g was dissolved at room temperature. To this solution was added 0.7 g of tin dibutyl laurate as a catalyst, followed by 1,4
A solution of 8.0 g of phenylenediisocyanate in 50 ml of dimethylformamide was added slowly.
After the dropping was completed, the temperature of the reaction solution was raised to 50 to 60 ° C. and the reaction was carried out for about 5 hours.

After completion of the reaction, the reaction solution was allowed to cool to room temperature, and 3
The mixture was concentrated under reduced pressure at a temperature of 0 ° C. or lower, the concentrate was dissolved in acetone, and the solution was poured into a large amount of ethanol to generate a precipitate. The obtained precipitate was thoroughly washed with ethanol and acetone in this order, and dried under reduced pressure to obtain R
A L-ascorbic acid segment-containing polymer of the formula (1) was obtained in which is a 1,4-phenylene diisocyanate residue of the formula (5).

Example 5 A deoxidizing material was prepared by molding 1 g of the L-ascorbic acid segment-containing polymer obtained in Example 1 into a film, which was then formed into a porous film bag (Asahi Kasei Co., Ltd.).
Manufactured) and then sealed in a 500 ml container using aluminum as an oxygen barrier material with 2 ml of water and 200 ml of air, and when sealed (0 days), 1 day, 3 days and 7 days later. The oxygen concentration (%) in the container was measured. The results (average of sample number n = 3) are shown in Table 1.
Shown in

Further, 1 g of the film-shaped L-ascorbic acid segment-containing polymer was immersed in water to examine its water resistance. As a result, L-ascorbic acid did not dissolve in water and showed excellent water resistance.

Example 6 A deoxidizing material was prepared by molding 1 g of the L-ascorbic acid segment-containing polymer obtained in Example 3 into a film, which was then formed into a porous film bag (Asahi Kasei Co., Ltd.).
Manufactured) and then sealed in a 500 ml container using aluminum as an oxygen barrier material with 2 ml of water and 200 ml of air, and when sealed (0 days), 1 day, 3 days and 7 days later. The oxygen concentration (%) in the container was measured. The results (average of sample number n = 3) are shown in Table 1.
Shown in

Further, 1 g of the film-shaped L-ascorbic acid segment-containing polymer was immersed in water to examine its water resistance. As a result, L-ascorbic acid did not dissolve in water and showed excellent water resistance.

Comparative Example 1 0.1 mol of L-ascorbic acid was replaced with EVA1 in place of the L-ascorbic acid-modified polyvinyl alcohol of the formula (1).
The water resistance was examined in the same manner as in Example 1 using 1 g of a sheet kneaded into 7.6 g and molded into a sheet. As a result, L
-Ascorbic acid was dissolved in water and the water resistance was insufficient.

[0042]

[Table 1] Oxygen concentration in sealed container (%) 0 day 1 day 3 days 7 days Example 5 20.9 15.72 12.66 9.94 Example 6 20.9 18.58 15.34 12.06

It can be seen from Table 1 that the deoxidizing materials of Examples 5 and 6 have sufficient oxygen absorbing ability.

[0044]

EFFECTS OF THE INVENTION According to the present invention, a polymer having an L-ascorbic acid unit introduced into its main chain can be provided by a simple method without using an enzyme or an acid chloride. Moreover, since the obtained polymer has a good oxygen reducing property, a deoxidizing material having a good deoxidizing ability can be obtained by using this oxygen reducing polymer.

Claims (5)

[Claims] 1. Formula (1): (In the formula, n is a number indicating the degree of polymerization, and R is a dibasic acid dihalide compound residue or a diisocyanate compound residue.) An L-ascorbic acid segment-containing polymer. 2. A dibasic acid dihalide compound residue of R is
Formula (2) or (3) The L-ascorbic acid segment-containing polymer according to claim 1, which is a divalent bonding group represented by: 3. A diisocyanate compound residue of R is
Formula (4) or (5) The L-ascorbic acid segment-containing polymer according to claim 1, which is a divalent bonding group represented by: 4. The method for producing an L-ascorbic acid segment-containing polymer according to claim 1, wherein R is a dibasic acid dihalide compound residue, wherein L-ascorbic acid is dibasic in the presence of a hydrogen halide scavenger. A process for producing an acid dihalide compound. 5. The method for producing an L-ascorbic acid segment-containing polymer according to claim 1, wherein R is a diisocyanate-based compound residue, wherein L is present in the presence of a tin-based catalyst.
-A production method characterized by allowing a diisocyanate compound to act on ascorbic acid.