JP2001226406A - High molecular-weight composition, method of producing the same, formed product and recyclization of used paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high polymer compound that has excellent moldability and flexibility with reduced environmental loading by utilizing vegetable waste resource such as used paper as a raw material and provide molded product therefrom. SOLUTION: This high polymer compound mainly comprises eaters from glucose and aliphatic dicarboxylic acids as the main chain where the glucose forms the ester bonds with the dicarboxylic acids in the 1 position and the 6 position and at least one of the hydroxyl groups at the 2, 3 and 4 position are acetylated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer compound, a method for producing the same, a method for recycling molded articles and waste paper, and more particularly to a polymer compound which can utilize waste resources and has a low environmental load, a method for producing the same, and a method for producing the same The present invention relates to a plastic product such as a molded product utilizing physical properties.

[0002]

2. Description of the Related Art In recent years, the amount of synthetic plastic waste has increased, and its disposal has become a major social problem. In the incineration of waste plastics, harmful gas may be generated, or damage to the incinerator may be caused by large combustion heat. In addition, if it is disposed or left in the soil, it may adversely affect the natural environment. With respect to synthetic plastic consumables, the problem of disposal of consumables after use has become important due to environmental problems and the like with the spread of devices.

On the other hand, the problem of waste includes an increase in surplus waste paper. In recent years, with the rapid spread of copiers and printers, paper waste tends to increase more and more. From the past, systems that reuse newspaper and corrugated paper as recycled paper have been established, but the demand for the entire used paper is limited, which is a problem. Therefore, it is extremely significant to use waste paper in a form other than recycled paper, and in particular, conversion to a plastic material is a desirable form that expands the usable range.

[0004] Waste resources derived from natural polymers other than waste paper include pressed slag in sugar production and brewing, and molasses remaining after purification. Molasses is not necessarily edible because it contains indigestible sugars.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above technical background, and an object of the present invention is to utilize a plant waste resource such as waste paper as a raw material, and to improve the formability and the like. An object of the present invention is to provide a polymer compound having excellent flexibility and a low environmental load, a method for producing the same, and a plastic product such as a molded product utilizing the properties thereof, and a method for recycling used paper.

[0006]

That is, one embodiment of the polymer compound according to the present invention is a polymer compound containing in its main chain an ester of glucose and an aliphatic dicarboxylic acid, wherein the glucose is the second compound. Forming an ester bond with the aliphatic dicarboxylic acid at the 1-position and the 6-position, and that at least one of the hydroxyl groups at the 2-, 3-, and 4-positions of the glucose is acetylated; It is a feature.

The second, third and fourth positions of the glucose
It is preferred that one or two of the hydroxyl groups at the position are acetylated. Preferably, the aliphatic dicarboxylic acid is adipic acid or sebacic acid. Preferably, the glucose is obtained by decomposing paper or starch. It is preferable that the main chain further contains an ester of an oligosaccharide and an aliphatic dicarboxylic acid. The oligosaccharide is 2 to 2 of glucose
Those which are hexamer partially acetylated compounds are preferred. Preferably, the oligosaccharide is obtained by decomposing paper or starch.

[0008] One embodiment of the method for producing a high molecular compound according to the present invention is a method for producing a high molecular compound containing an ester of glucose and an aliphatic dicarboxylic acid in the main chain, comprising: Esterifying the hydroxyl groups at the first and sixth positions with an aliphatic dicarboxylic acid to form a polymer chain containing an ester of glucose and an aliphatic dicarboxylic acid; and (ii) forming a polymer chain containing an ester of glucose with an aliphatic dicarboxylic acid; Acetylating at least one hydroxyl group at the 3-position and the 4-position. Step (i) and step (i)
Preferably, i) is performed in the same reaction vessel.

[0009] In one embodiment of the molded article according to the present invention, an ester of glucose and an aliphatic dicarboxylic acid is contained in the main chain, and the glucose is substituted with the aliphatic dicarboxylic acid at the first and sixth positions. An ester bond is formed, and at least one of the hydroxyl groups at the second, third and fourth positions of the glucose contains a polymer compound which is acetylated, and is formed into a predetermined shape by heating. It is characterized by being done.

In one embodiment of the molded article according to the present invention, an ester of glucose and an aliphatic dicarboxylic acid is contained in the main chain, and the glucose is substituted with the aliphatic dicarboxylic acid at the first and sixth positions. An ester bond is formed, and at least one of the second, third, and fourth hydroxyl groups of the glucose contains a polymer compound that is acetylated, and is pressurized into a predetermined shape. It is characterized by being formed.

Preferably, the aliphatic dicarboxylic acid is adipic acid or sebacic acid. Preferably, the backbone further comprises an ester of an oligosaccharide and an aliphatic dicarboxylic acid. It is preferred that the oligosaccharide is a partially acetylated form of a 2- to 6-mer of glucose.

Further, the present invention is a sheet-like article comprising the above-mentioned polymer compound. Further, the present invention is a film-like article comprising the above-mentioned polymer compound. Further, the present invention is a container comprising the above-mentioned polymer compound.

[0013] The present invention is also a foamed molded article obtained by subjecting the above polymer compound to foam molding.

Further, the present invention relates to a method for recycling used paper, comprising: (i) a step of decomposing and saccharifying the used paper to obtain glucose; and (ii) reacting the glucose with an aliphatic dicarboxylic acid. Containing an ester of glucose and an aliphatic dicarboxylic acid in the main chain, the glucose forming an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions, and the second and third positions of the glucose. Obtaining a polymer compound in which at least one of the hydroxyl groups at the 4th and 4th positions is acetylated.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer compound according to the present invention comprises
A polymer compound containing an ester of glucose and an aliphatic dicarboxylic acid in a main chain, wherein the glucose forms an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions, and At least one of the 2-, 3-, and 4-position hydroxyl groups is acetylated.

Specifically, for example, it is a polymer compound having a unit represented by the following general formula (I).

[0017]

Embedded image (Wherein n = 4-8, R ₁ -R ₃ are hydrogen atoms or CH
₃ CO—, wherein at least one of R _{1 to} R ₃ is CH ₃ C
O-. )

Glucose in which one or two of the second, third and fourth hydroxyl groups of the glucose are acetylated is particularly preferred because of its excellent properties such as thermoformability and flexibility. . Glucose may be α-type or β-type.

The polymer compound according to the present invention may be a homopolymer composed of only the unit represented by the above general formula (I), or a unit represented by the above general formula (I), an oligosaccharide and an aliphatic compound. It may be a copolymer with an ester unit with a dicarboxylic acid. As the oligosaccharide in the case of a copolymer, a partially acetylated form of a dimer to hexamer of glucose and the like can be mentioned.

The weight average molecular weight of the polymer compound is usually 5 to 7,000,000, preferably 1 to 1,000,000.

If it is noted that cellulose as a main component of paper and amylose and amylopectin as main components of starch are multimers of glucose, saccharide compounds (glucose, oligosaccharide) obtained by the chemical decomposition of these are considered. Such)
Is copolymerized with an aliphatic dicarboxylic acid having the same number of carbon atoms as the sugar ring (hereinafter abbreviated as fatty acid) or a derivative thereof, whereby it can be converted into a polymer compound. In this method, since the main chain structure of the saccharide multimer as a raw material is modified, its physical properties can be largely changed. In addition, the method involving the chemical decomposition of the raw material saccharide multimer can selectively obtain monosaccharides and oligosaccharides while separating contaminants insoluble in water. This is extremely effective when utilizing plant-based scum and the like.

As a result of repeated studies on the above-described polymer compound having a saccharide in the main chain, the polymer compound having the unit represented by the above general formula (I) was found to have a thermoformability, It has been found that it is particularly excellent in flexibility and can be produced by an easy synthesis process.

The method for producing the polymer compound according to the present invention includes, for example, (i) esterifying the hydroxyl groups at the 1st and 6th positions of glucose with an aliphatic dicarboxylic acid to prepare glucose and an aliphatic dicarboxylic acid. And (ii) a step of acetylating at least one hydroxyl group at the second, third, and fourth positions of the glucose.

Hereinafter, a method for synthesizing the polymer compound according to the present invention will be specifically described. First, a case where only glucose is used as a raw sugar will be described. In the step (i), glucose is converted into an oligomer by reaction with fatty acid dichloride in a solvent such as dimethylformamide. At this time, it has been found that, if performed under mild conditions with excess glucose, a fatty acid moiety can be almost selectively introduced into the 1st and 6th positions of glucose without performing any complicated protection and deprotection steps.

Next, as the step (ii), the subsequent increase in molecular weight and acetylation with acetic anhydride are performed in parallel. Thereby, it is possible to suppress the fatty acid moiety from attacking other than the 1st and 6th positions of glucose, and to achieve one-dimensional elongation of the polymer chain while suppressing branching and crosslinking of the polymer chain on the sugar ring. Is possible. The above steps (i) and (i)
i) can be performed in parallel in one reaction vessel, and the target polymer compound can be obtained very easily.

Introduction of an acetyl group not only suppresses branching and crosslinking, but also improves the thermal stability and water resistance of the polymer compound. If all remaining hydroxyl groups of the glucose unit are acetylated, the melt viscosity will increase. Therefore, considering the moldability, the number of the acetyl groups is determined by
It is desirable to limit the number to 1 or 2 pieces.

The above-mentioned fatty acid dichloride and acetic anhydride are one example of the reaction reagent, and are not limited thereto. For example, main chain extension may be dehydration condensation with a fatty acid, and acetyl chloride may be used instead of acetic anhydride. Further, purification and solvent exchange may be performed after the former step, and then the latter step may be performed.

As described above, the sugar in the polymer compound according to the present invention may contain an oligosaccharide other than glucose. As for the oligosaccharide, it is desirable to use a sugar of 6 or less composed of a dimer to hexamer of glucose. 7
In the case of sugars or more, there is a concern that the melt viscosity is too high when the compound is contained in the main chain of the target polymer compound because the water solubility is low and the fractionation in the decomposition saccharification described later is not easy. . The oligosaccharide content relative to glucose is
Although not particularly limited, when the oligosaccharide content is high, the synthesized polymer compound is harder, and thus is determined according to the application.

The synthesis operation is almost the same when oligosaccharides are mixed, and the amount of acetic anhydride may be adjusted according to the number of hydroxyl groups to be suppressed. That is, in the oligosaccharide, since the number of hydroxyl groups unnecessary for one-dimensional polymer synthesis increases, the amount of acetic anhydride is increased according to the amount.

As the fatty acid, adipic acid or sebacic acid is desirable as a fatty acid which is well-balanced with the hard segment (hard main chain portion) of 1 to 6 saccharides and is easily available. These are selected according to the physical properties required for the intended use, for example, hardness, elongation and the like.

The polymer compound of the present invention is characterized by a one-dimensional polymer chain. Among the polymer compounds having the same composition which the present inventors have studied so far, particularly, even at a high molecular weight, The feature is that flexibility is maintained. Therefore, the polymer compound of the present invention is suitable for a molded article itself or when a tension or elongation is required during molding. That is, it is suitable for a film-like or sheet-like member by a T-die method, a tubular or bag-like member by inflation molding, a bottle-like container by blow molding, a cushioning material by foam molding, and the like.

The above-mentioned molded article and molding method are preferred examples, and the present invention is not limited thereto. Other members such as injection molding, extrusion molding, compression molding and the like can be applied to form a thick member.

The weight average molecular weight of the polymer compound of the present invention is not particularly limited. However, from the viewpoint of strength and dimensional stability, it is preferable that components having a weight average molecular weight of less than 10,000 are not contained as much as possible. desirable.

Further, the polymer compound of the present invention includes a coloring material,
Stabilizers, plasticizers, fillers and the like may be added. Especially for filler, when used paper is used as raw material,
It is extremely significant to utilize the long cellulose fibers remaining in the unreacted residue at the time of decomposition.

Further, since the polymer compound and the molded article of the present invention are all or most of them biodegradable, even if they are discarded in a natural environment,
It is possible to minimize adverse effects on the environment.

In the method for producing a polymer compound of the present invention, when paper (waste paper) or plant-based pressed slag is used as a raw material, it is chemically decomposed to obtain βl of cellulose contained as a constituent component. → By breaking the 4 bond, glucose (monosaccharide) and cellooligosaccharide (2-6 hexasaccharide) can be obtained as water-soluble components. Examples of the method of such decomposed saccharification include decomposition with a dilute acid such as dilute hydrochloric acid and dilute sulfuric acid, decomposition with an enzyme such as cellulase, decomposition with high-temperature and high-pressure water, and the like. In these processes, fillers, coloring materials, undecomposed long fibers, and the like that are insoluble in water can be easily separated as residue.

The same applies when starch or molasses based on starch is used as a raw material. However, amylase or the like is used for the decomposition by the enzyme.

Further, since the polymer compound of the present invention is a polyester, depolymerization can be carried out by cleavage of an ester bond by hydrolysis, and saccharides and fatty acids are produced as decomposition products. That is, it is possible to reuse the waste of the molded article comprising the polymer compound of the present invention as a raw material. For this hydrolysis, it is desirable to use an aqueous solution of sodium hydroxide or an enzyme such as lipase or esterase.

[0039]

EXAMPLES The present invention will be specifically described below with reference to examples. However, “parts” means “parts by weight” unless otherwise specified.

Example 1 An example of (glucose / adipic acid) will be described. 50 parts of glucose, 200 parts of dimethylformamide and 100 parts of pyridine were stirred at room temperature under a nitrogen atmosphere, and a solution prepared by diluting 20 parts of adipic acid chloride with 100 parts of dimethylformamide was gradually dropped therein, and stirred for 1 h (hour). did. After 1 hour, 20 parts of adipic acid chloride were added dropwise,
Stirred. After the next 1 h, a solution obtained by diluting 30 parts of acetic anhydride with 100 parts of dimethylformamide as a solvent was gradually added dropwise, and the mixture was stirred for 1 h. After the next hour, adipic acid chloride 2
A solution obtained by diluting 0 part with 100 parts of dimethylformamide was gradually added dropwise, followed by stirring for 1 hour. After the next hour, pyridine 2
0 parts were added, and 20 parts of adipic chloride was added dropwise.
h. After a part of the solvent was distilled off, the solution was poured into water and reprecipitated, and the generated precipitate was washed three times with methanol to obtain a polymer compound. The weight average molecular weight of the polymer compound is about 45
It was 10,000.

FIG. 1 shows the ¹ H-NMR spectrum of the polymer compound. From FIG. 1, the substitution positions of glucose are mainly at the 1-position (5.7 to 6.2 ppm, 1H) and 6-position (3.8).
-4.2 ppm, 2H), the composition ratio of glucose and adipic acid is about 1: 1, and the number of acetyl groups (1.9-2.1 ppm, 3H) is almost one per glucose. Confirmed that there is.

Example 2 An example of (glucose / sebacic acid system) will be described. 50 parts of glucose, 200 parts of dimethylformamide and 100 parts of pyridine were stirred at room temperature under a nitrogen atmosphere, and 20 parts of sebacic chloride was added to 100 parts of dimethylformamide.
The solution diluted in the above part was gradually added dropwise and stirred for 1 h. lh
Thereafter, 30 parts of sebacic chloride was added dropwise and stirred for 1 h. After the next 1 h, a solution obtained by diluting 30 parts of acetic anhydride with 100 parts of dimethylformamide as a solvent was gradually added dropwise.
Stirred. After the next 1 h, a solution prepared by diluting 20 parts of sebacic chloride with 100 parts of dimethylformamide was gradually added dropwise, and the mixture was stirred for 1 h. After the next 1 h, 20 parts of pyridine was added, 20 parts of sebacic chloride was added dropwise, and the mixture was stirred for 6 hours. After distilling off part of the solvent, it is poured into water and reprecipitated,
The generated precipitate was washed three times with methanol to obtain a polymer compound. The weight average molecular weight of the polymer compound was about 6.15 million.

FIG. 2 shows the ¹ H-NMR spectrum of the polymer compound. As shown in FIG. 2, the substitution positions of glucose are mainly at the 1-position (5.6 to 6.2 ppm, 1H) and the 6-position (3.9).
To 4.3 ppm, 2H), the composition ratio of glucose to adipic acid portion is about 1: 1, and the number of acetyl groups (1.9 to 2.1 ppm, 3H) is almost one per glucose. Confirmed that there is.

Example 3 An example of synthesis from waste paper will be described. Used cardboard paper (both sides, A flute) was cut into 5 mm squares, and 100 g of the cut paper was put into 3 liters of the enzyme solution and stirred at 45 ° C. for 6 hours.
The enzyme solution was prepared by adding 10 g of cellulase (Meitherase TP60, manufactured by Meiji Seika Co., Ltd.) to an acetic acid / sodium acetate aqueous solution (pH
4.5) A solution dissolved in 3 liters was used. After the reaction,
After adding 200 ml of methanol, the insoluble residue was filtered off, and further ion-exchange resin column (Amberlite IR-
After passing through 50 cm (120B, manufactured by Organo Co.), the solvent was distilled off and dried to obtain 64 g of a slightly yellow powder mainly composed of glucose (78%), cellobiose (19%) and cellotriose (3%).

In the same manner as in Example 2, 50 g of this saccharide mixture was copolymerized with sebacic chloride to obtain a high molecular compound. The weight average molecular weight of the polymer compound was about 810,000.

Example 4 An example of (glucose / maltose / sebacic acid system) will be described. A mixture of 25 parts of glucose and 25 parts of starch-derived maltose (Finetose F, manufactured by Hayashibara) was copolymerized with sebacic chloride in the same manner as in Example 2 to obtain a polymer compound. However, the amount of acetic anhydride was 45 parts (1.5 times the quantitative ratio of Example 2). The weight average molecular weight of the polymer compound was about 5.8 million.

Examples 5 to 8 Examples of the production of a film-like member will be described. From the polymer compound powder synthesized in Examples 1 and 2, a 0.2 mm thick film-shaped member was produced by T-die extrusion molding. In addition, a sheet member having a thickness of 1 mm was prepared from the polymer compound powder synthesized in Examples 3 and 4 by press molding. The resin temperature was 100 to 120 ° C in all cases. In each case, a transparent and flexible molded article was obtained.

Examples 9 to 11 Examples of the production of various molded articles will be described. Moldings of various shapes were produced under the conditions shown in Table 1. Extrusion in inflation molding and blow molding is 100 to 120 ° C.
I went in. In each case, good molded articles were obtained.

[0049]

[Table 1]

[0050]

As described above, according to the present invention, a high-molecular compound having excellent moldability and flexibility and a low environmental load, utilizing natural waste resources such as waste paper as a raw material, and its use. A plastic product utilizing physical properties can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a ¹ H-NMR spectrum of a glucose / adipic acid-based polymer compound of Example 1.

FIG. 2 is a diagram showing a ¹ H-NMR spectrum of a glucose / sebacic acid-based polymer compound of Example 2.

Claims (21)

[Claims] 1. A high molecular compound containing, in its main chain, an ester of glucose and an aliphatic dicarboxylic acid, wherein the glucose forms an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions, The second of the glucose
At least one of the hydroxyl groups at the 3rd, 3rd and 4th positions
One is a polymer compound characterized by being acetylated. 2. The polymer compound according to claim 1, wherein one or two of the hydroxyl groups at the second, third and fourth positions of the glucose are acetylated. 3. The polymer compound according to claim 1, wherein the aliphatic dicarboxylic acid is adipic acid or sebacic acid. 4. The polymer compound according to claim 1, wherein the glucose is obtained by decomposing paper. 5. The polymer compound according to claim 1, wherein the glucose is obtained by decomposing starch. 6. The polymer compound according to claim 1, wherein the main chain further contains an ester of an oligosaccharide and an aliphatic dicarboxylic acid. 7. The polymer compound according to claim 6, wherein the oligosaccharide is a partially acetylated form of a dimer to hexamer of glucose. 8. The polymer compound according to claim 6, wherein the oligosaccharide is obtained by decomposing paper. 9. The polymer compound according to claim 6, wherein the oligosaccharide is obtained by decomposing starch. 10. A method for producing a polymer compound containing an ester of glucose and an aliphatic dicarboxylic acid in a main chain thereof, wherein (i) the first and sixth hydroxyl groups of glucose are esterified with an aliphatic dicarboxylic acid. Forming a polymer chain containing an ester of glucose and an aliphatic dicarboxylic acid; and (ii) acetylating at least one hydroxyl group at the second, third and fourth positions of the glucose. And a process for producing a polymer compound. 11. The method for producing a polymer compound according to claim 10, wherein the step (i) and the step (ii) are performed in the same reaction vessel. 12. The main chain comprises an ester of glucose and an aliphatic dicarboxylic acid, the glucose forming an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions, and the second bond of the glucose. Place, third place and fourth place
A molded article characterized in that at least one of the hydroxyl groups contains a polymer compound which is acetylated, and is formed into a predetermined shape by heating. 13. An ester of glucose and an aliphatic dicarboxylic acid in the main chain, the glucose forming an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions, and a second bond of the glucose. Place, third place and fourth place
A molded article characterized in that at least one of the hydroxyl groups contains a polymer compound that is acetylated, and is formed into a predetermined shape by applying pressure. 14. The molded article according to claim 12, wherein the aliphatic dicarboxylic acid is adipic acid or sebacic acid. 15. The molded article according to claim 12, wherein the main chain further contains an ester of an oligosaccharide and an aliphatic dicarboxylic acid. 16. The molded article according to claim 15, wherein the oligosaccharide is a partially acetylated form of a dimer to hexamer of glucose. A sheet-like article comprising the polymer compound according to any one of claims 1 to 9. 18. A film-like article comprising the polymer compound according to claim 1. Description: A container comprising the polymer compound according to any one of claims 1 to 9. 20. A foam molded article obtained by subjecting the polymer compound according to claim 1 to foam molding. 21. A method for recycling used paper, comprising: (i) a step of decomposing and saccharifying the used paper to obtain glucose; and (ii) reacting the glucose with an aliphatic dicarboxylic acid to obtain glucose and fat. An ester with an aliphatic dicarboxylic acid in the main chain, wherein the glucose forms an ester bond with the aliphatic dicarboxylic acid at the first and sixth positions;
And a step of obtaining a polymer compound in which at least one of the second, third and fourth hydroxyl groups of glucose is acetylated.