JP2010254932A - Polyester and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel polyester obtained by the ring-opening polymerization of a δ-valerolactone derivative derived from 2-pyrone-4, 6-dicarboxylic acid derived from a lignin-including biomass, and a method for producing the same. <P>SOLUTION: The polyester has repeating units represented by formula (1) (wherein R<SB>1</SB>is independently H, a 1-6C monovalent alkyl group, an aromatic group, or a heterocyclic group). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to polyester and a method for producing the same.

  Today, various polymers such as polyethylene, polypropylene, polyvinyl chloride, and polyethylene terephthalate are widely used for molded products such as various containers, garbage bags, packaging bags, and the like. However, since these polymers are mainly made from petroleum, if they are incinerated at the time of disposal, they increase carbon dioxide in the atmosphere and contribute to global warming. On the other hand, when landfilled without incineration, there are many things that are hardly decomposed in the natural environment, so they remain in the ground semipermanently.

  In recent years, plant-derived polymers obtained through plant-derived raw materials and metabolism by microorganisms have attracted attention. Because these polymers are environmentally-circulating materials that do not use petroleum as a raw material, carbon dioxide fixed in plants is returned to the atmosphere. I won't let you. Even if landfilled without incineration, it is decomposed by microorganisms in the soil, so there is no risk of environmental destruction. Examples of such plant-derived polymers include polylactic acid, polyhydroxybutyric acid, and the like, and development of uses for various molded products is being promoted as a biodegradable material with future potential. However, such a plant-derived polymer has a problem of competing with food in supply when the raw material is food that is a grain containing starch or the like. This is a problem from the viewpoint of a stable supply of food to mankind.

  By the way, lignin, a plant-derived aromatic polymer compound, is a biomass resource that is universally contained in plant cell walls, but its chemical structure is composed of various components and has a complex polymer structure. Therefore, effective utilization technology has not been developed yet. Therefore, for example, lignin produced as a by-product in a large amount in the paper industry is not effectively used but is incinerated as an alternative fuel for heavy oil.

In recent years, plant-derived aromatic components such as lignin have been converted into several small molecules by chemical decomposition methods such as hydrolysis, oxidative decomposition, solvolysis, or physicochemical decomposition methods using supercritical water or supercritical organic solvents. Methods have been developed to convert to a mixture of compounds to produce a single compound, 2-pyrone-4,6-dicarboxylic acid. For example, Japanese Patent Laid-Open No. 2005-278549 (hereinafter referred to as Patent Document 1) discloses a low raw material containing vanillin, syringaldehyde, vanillic acid, syringic acid, and protocatechuic acid obtained from a plant raw material containing lignin by a low molecular weight technology. A method for producing 2-pyrone-4,6-dicarboxylic acid (hereinafter also referred to as PDC), which is a single compound, from a molecular mixture through a multi-stage enzymatic reaction by a fermentation production technique is disclosed. Japanese Patent Laid-Open No. 2008-79603 (hereinafter referred to as Patent Document 2) discloses that a cation salt is present in a fermentation solution containing 2-pyrone-4,6-dicarboxylic acid produced by a microorganism. A method for purifying pyrone-4,6-dicarboxylic acid and a method for extracting free 2-pyrone-4,6-dicarboxylic acid are disclosed.
The ester of PDC can be obtained, for example, by the method described in International Publication WO99 / 54376 pamphlet (refer to Patent Document 3 below).

  If 2-pyrone-4,6-dicarboxylic acid, which is a single compound thus obtained, can be used as a raw material for biodegradable plastics and various chemical products, it will not compete with food in supply. Thus, the lignin-containing plant material (biomass) can be used effectively. However, a method for utilizing 2-pyrone-4,6-dicarboxylic acid derived from lignin-containing biomass has not yet been established.

JP 2005-278549 A JP 2008-79603 A International Publication WO99 / 54376 Brochure

  The problem to be solved by the present invention is to provide a novel polyester obtained by ring-opening polymerization of a δ-valerolactone derivative derived from 2-pyrone-4,6-dicarboxylic acid derived from lignin-containing biomass, and a process for producing the same. That is.

In order to solve the above-mentioned problems, the present inventor has repeated experiments and made extensive studies. As a result, the present inventors have obtained a δ-valerolactone derivative (hereinafter referred to as tetrahydro-2H-pyrone-4, 4) from 2-pyrone-4,6-dicarboxylic acid. 6-dicarboxylate) was actually produced, and the δ-valerolactone derivative was ring-opening polymerized to actually produce a polyester, the production method was established, and the present invention was completed.
That is, the present invention is the following [1] to [9]:

｛式中、Ｒ_１は、独立に、Ｈ又は炭素数１〜６個を有する１価のアルキル基である。｝で表される繰り返し単位を有するポリエステル。 [1] The following formula (1):

{In the formula, R ₁ is independently H or a monovalent alkyl group having 1 to 6 carbon atoms. } The polyester which has a repeating unit represented by these.

｛式中、Ｒ_１は、独立に、芳香族基又は複素環基である。｝で表される繰り返し単位を有するポリエステル。 [2] The following formula (1):

{In the formula, R ₁ is independently an aromatic group or a heterocyclic group. } The polyester which has a repeating unit represented by these.

で表される繰り返し単位を有するポリエステル。 [3] The following formula (2):

The polyester which has a repeating unit represented by these.

｛式中、Ｒ_１は、独立に、Ｈ；炭素数１〜６個を有する１価のアルキル基；芳香族基；又端複素環基である。｝で表されるδ−バレロラクトン誘導体を、触媒の存在下、重合させて、以下の式（１）：

｛式中、Ｒ_１は、独立に、Ｈ；炭素数１〜６個を有する１価のアルキル基；芳香族基；又は複素環基である。｝で表される繰り返し単位を有するポリエステルを製造する方法。 [4] The following formula (3):

{Wherein, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; an aromatic group; or a terminal heterocyclic group. } Is polymerized in the presence of a catalyst to give the following formula (1):

{Wherein, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; an aromatic group; or a heterocyclic group. } The manufacturing method of polyester which has a repeating unit represented by these.

で表される２−ピロン−４，６−ジカルボン酸ジメチルを、触媒の存在下、重合させて、以下の式（２）：

で表される繰り返し単位を有するポリエステルを製造する方法。 [5] The following formula (4):

In the presence of a catalyst, dimethyl 2-pyrone-4,6-dicarboxylate represented by the following formula (2) is polymerized:

A process for producing a polyester having a repeating unit represented by the formula:

[6] The method according to [4] or [5], wherein the catalyst is organotin.

[7] The method according to any one of [4] to [6], wherein the organotin is tin 2-ethylhexanoate.

[8] The method according to any one of [4] to [7], wherein the polymerization reaction is performed at room temperature to 130 ° C.

[9] The method according to any one of [4] to [8], wherein the polymerization reaction is performed over a time period of 1 to 24 hours.

｛式中、Ｒ_１は、独立に、Ｈ；非置換の炭素数１〜６個を有する１価のアルキル基；芳香族基：又は複素環基である。｝で表される。式中、Ｒ_１は、具体的には、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｔｅｒｔ−ブチル基、ｎ−ペンチル基、イソペンチル基、ｎ−ヘキシル基、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロプロピルメチル基、シクロペンチルメチル基できる。Ｒ_１が、メチル基である場合、モノマー、δ−バレロラクトン誘導体は、以下の式（４）：

で表される２−ピロン−４，６−ジカルボン酸ジメチルである。 Hereinafter, the present invention will be described in more detail.
The monomer, δ-valerolactone derivative, which is the starting material for the polymerization reaction, has the following formula (3):

{In the formula, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms which is unsubstituted; an aromatic group: or a heterocyclic group. }. In the formula, R ₁ is specifically methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl. Group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, cyclopentylmethyl group. When R ₁ is a methyl group, the monomer, δ-valerolactone derivative is represented by the following formula (4):

It is 2-pyrone-4,6-dicarboxylate dimethyl represented by these.

  There is no limitation on the method for obtaining the monomer and δ-valerolactone derivative as the starting material for the polymerization reaction. For example, as disclosed in Patent Document 1, vanillin obtained from a plant raw material containing lignin by a low molecular weight technology Esterification of 2-pyrone-4,6-dicarboxylic acid obtained from a low-molecular-weight mixture containing syringaldehyde, vanillic acid, syringic acid, and protocatechuic acid by fermentation production technology through a multi-stage enzymatic reaction This can be obtained by reduction in the presence of a hydrogenation catalyst.

  For example, as described in Patent Document 3, PDC is esterified with PDC in the presence of an acid such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid and the like, for example, methanol, ethanol, n-propyl alcohol. , Polyalkylene glycol, for example, ethylene glycol, propylene glycol, polyalkylene oxide, for example, ethylene oxide, propylene oxide, is reacted by heating, if necessary.

｛式中、Ｒ_１は、独立に、Ｈ；炭素数１〜６個を有する１価のアルキル基；芳香族基；又は複素環基である。｝。 For example, according to the following reaction scheme, the PDC ester is reduced to a δ-valerolactone derivative (tetrahydro-2H-pyrone-4,6-dicarboxylate).

{Wherein, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; an aromatic group; or a heterocyclic group. }.

  Examples of the hydrogen source in the reduction of the PDC ester include hydrocarbons such as hydrogen gas, formic acid, sodium formate, silyl hydride, cyclohexanediene, methylcyclohexane, decahydronaphthalene and the like. The usage-amount of a hydrogen source is 2 mol or more normally with respect to the quantity of the PDC ester to be used, and there is no upper limit in particular.

  Examples of the hydrogenation catalyst include a palladium catalyst, a nickel catalyst, a platinum catalyst, a ruthenium catalyst, a rhenium catalyst, a copper catalyst, a rhodium catalyst, or a mixture thereof. In particular, from the viewpoint of reactivity and economy, a palladium catalyst, a nickel catalyst, a platinum catalyst, or a ruthenium catalyst is preferable. Examples of the palladium catalyst include palladium carbon, palladium alumina, palladium silica, palladium silica alumina, and zeolite-supported palladium. As the palladium catalyst, either a dried product or a hydrated product may be used, but a hydrated product is preferred from the viewpoint of industrial process stability. Examples of the nickel catalyst include nickel diatomaceous earth, sponge nickel, nickel alumina, nickel silica, nickel carbon, and the like. Examples of the platinum catalyst include platinum silica, platinum silica alumina, zeolite-supported platinum, and the like. Examples of the ruthenium catalyst include ruthenium carbon, ruthenium alumina, ruthenium silica, ruthenium alumina, and zeolite-supported ruthenium. The amount of the hydrogenation catalyst used for the reduction can be usually 0.1 to 1 mol% with respect to the number of moles of the PDC ester used in metal conversion.

  The reduction reaction can be performed at 0 ° C. to room temperature for several hours to several days. When formic acid is used as a hydrogen source, a reaction solvent is not required, but the following reaction solvent may be further added. Examples of the reaction solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xitene; lower alcohols such as methanol, ethanol, propanol, isopropanol, and butane; diethyl ether, Ethers such as tetrahydrofuran and diisopropyl ether; Nitriles such as acetonitrile, propionitrile and benzonitrile; Halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane and trichloroethane; Cymethyl sulfoxide; 1,3-propane Diols, diols such as 1,4-butanediol; or a mixed solvent thereof. The amount of the solvent added during the reduction can be usually 1 to 200 times by weight based on the amount of the PDC ester used.

  The obtained δ-valerolactone derivative (tetrahydro-2H-pyrone-4,6-dicarboxylate) is isolated and purified by a conventional method.

に従って、δ−バレロラクトン誘導体を、触媒の存在下、開環重合させて式（１）｛式中、Ｒ_１は、独立に、Ｈ；炭素数１〜６個を有する１価のアルキル基；芳香族基；又は複素環基である。｝で表される繰り返し単位を有するポリエステルポリエステルを製造することができる。 The following reaction scheme:

In accordance with the formula (1) {wherein R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; An aromatic group; or a heterocyclic group. } The polyester polyester which has a repeating unit represented by this can be manufactured.

  The polymerization catalyst used in the above polymerization reaction is a catalyst comprising a titanium salt or oxide, an alkali metal or alkaline earth metal oxide or carbonate; a basic cation catalyst such as a metal alkoxide; tin, aluminum, zinc, rare earth It can be a complex of metal, titanium, palladium, molybdenum and the like, for example, an organic tin-based catalyst, for example, 2-ethylhexanoic acid tin. The usage-amount of the catalyst to be used can be about 0.1-1 mol% with respect to the sum total of a polymerization initiator and a lactone monomer.

  In the polymerization reaction, a polymerization initiator can be used. Examples of the polymerization initiator include alcoholates such as sodium methylate obtained by dehydrating methanol and sodium hydroxide.

The polymerization reaction can also be performed in a polymerization solvent. The polymerization solvent is not particularly limited as long as it does not inhibit the polymerization reaction. For example, aliphatic hydrocarbons or cyclic hydrocarbons having 5 to 18 carbon atoms, aromatic hydrocarbons having 6 to 20 carbon atoms, etc. Inert solvents such as toluene, n-heptane, isopentane, hexane, octane, nonane, decane, cyclohexane, benzene, xylene, ethylbenzene, chloroform, dichloroethane and other chlorinated organic solvents, ethyl ether, diethyl ether and other ethers Is mentioned. Alcohols should not be used because they lead to the delay, inhibition and termination of the polymerization reaction.
The polymerization reaction may be performed within a temperature range of room temperature to 130 ° C., for example, at about 80 ° C. The polymerization reaction is usually performed over a time period of 1 to 24 hours.

  Since the starting raw material monomer δ-valerolactone derivative (tetrahydro-2H-pyrone-4,6-dicarboxylate) is a low viscosity liquid, it can be easily stirred with a magnetic stirrer or the like in the polymerization reaction. . In the polymerization reaction, for example, the addition of Sn catalyst can be stirred.

  The polymer obtained by the polymerization reaction is polyester, but is ester type polymethyl acrylate. Since ester bonds exist between the polymer units and in the side chain methyl groups, the obtained polymer is easily decomposed with an alkali. Furthermore, it is easy to form a crosslinked structure through a transesterification reaction. Therefore, by further modifying the obtained polymer, it is possible to add functions that meet various purposes.

で表されるジメチルテトラヒドロ−２Ｈ−ピロン−４，６−カルボキシレートであることが判明した。
^１Ｈ−ＮＭＲ（３００ＭＨｚ，ＣＤＣｌ_３）δ（ｐｐｍ）：２．３９−２．４１（ｑ），２．５５−２．６８（ｍ），２．６８−２．８１（ｍ），２．８１−２．９４（ｍ），２．９８−３．１１（ｍ），３．７２（ｓ），３．８２（ｓ），４．９７（ｄ）。
^１３Ｃ−ＮＭＲ（３００ＭＨｚ，ＣＤＣｌ_３）δ（ｐｐｍ）：３１．５（ピラン環ＣＨ_２），３３．８（ピラン環ＣＨ_２），３４．０（ピラン環ＣＨ），５１．８（ＣＨ_３），５２．６（ＣＨ_３），７３．７（ピラン環ＣＨ），１７０．２（ピラン環アシル），１７０．７（カルボニル），１７６．９（カルボニル）。
ＧＣ−ＭＳ：ｍ／ｚ＝１８５，１７１，１５７，１４３，１２５。
ＩＲ（ν（ｃｍ^−１））：２９５９（−ＣＨ），２８５８（−ＣＨ_２−），１７５０（カルボン酸のＣ＝Ｏ），１７３３（ラクトンのＣ＝Ｏ），１４４４（−ＣＨ），１０６２（Ｃ−Ｏ）。 The invention will now be illustrated by non-limiting examples.
Reference Example 1: Production of δ-valerolactone derivative (dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate) 2H-pyran-4,6-produced by a method described in WO99 / 54376 in a 100 ml eggplant flask. Dicarboxylate (4.8 g, 22.9 mmol) and butanediol (20 mL) were added, degassing and nitrogen introduction were repeated three times, and the system was put under a nitrogen atmosphere. Here, Pd / C (0.48 g) was added, and deaeration and nitrogen introduction were repeated three times. After reducing the pressure in the system, hydrogen gas was introduced and stirred vigorously to initiate the hydrogenation reaction. The reaction was carried out for 1 day while appropriately confirming the decrease in the raw material concentration and the appearance of new spots by thin layer chromatography (TLC). The reaction product was filtered to remove Pd / C, and butanol in the filtrate was removed by an evaporator to obtain a crude product (5.4 g). The crude product was purified by silica gel column chromatography (developing solution: chloroform / ethyl acetate (7/3)) to obtain a compound (A1).

It was found to be dimethyltetrahydro-2H-pyrone-4,6-carboxylate represented by
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 2.39-2.41 (q), 2.55-2.68 (m), 2.68-2.81 (m), 2. 81-2.94 (m), 2.98-3.11 (m), 3.72 (s), 3.82 (s), 4.97 (d).
¹³ C-NMR (300 MHz, CDCl ₃ ) δ (ppm): 31.5 (pyran ring CH ₂ ), 33.8 (pyran ring CH ₂ ), 34.0 (pyran ring CH), 51.8 (CH ₃ ), 52.6 (CH ₃ ), 73.7 (pyran ring CH), 170.2 (pyran ring acyl), 170.7 (carbonyl), 176.9 (carbonyl).
GC-MS: m / z = 185, 171, 157, 143, 125.
IR (ν (cm ⁻¹ )): 2959 (—CH), 2858 (—CH ₂ —), 1750 (C═O of carboxylic acid), 1733 (C═O of lactone), 1444 (—CH), 1062 (C-O).

で表される化合物ジメチルテトラヒドロ−２Ｈ−ピロン−４，６−ジカルボキシレート（１．５ｇ、収率３６％）を得た。 Production Example 1: Production of δ-valerolactone derivative (dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate) A 100 ml eggplant flask was prepared according to formic acid (8 ml) and the method described in Patent Document 3. Dimethyl 2-pyrone-4,6-dicarboxylate (2.5 g, 1.1 mmol) was added and stirred to prepare a suspension. Next, after the inside of the eggplant flask was deaerated and replaced with nitrogen gas, Pd / C (1.2 g) was added, and stirring was continued while reducing the pressure so that the formic acid did not boil. The formic acid was added and degassed while appropriately confirming the decrease in the concentration of the raw material by thin layer chromatography (TLC), and the reaction was continued for 5 days. The reaction product was filtered to remove Pd / C, and the formic acid in the filtrate was removed by an evaporator to obtain a crude product (2.5 g). The crude product was purified using silica gel chromatography (developing solution: chloroform / ethyl acetate (7/3)), and the following formula (4):

The compound represented by this was obtained dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate (1.5 g, yield 36%).

It was confirmed by ¹ H-NMR, ¹³ C-NMR, GC-MS, and IR measurement that the reduction product was dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate.
(1) ¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 2.39-2.41 (q, 1.2 H), 2.63-2.65 (m, 2.3 H), 2. 65-2.82 (t, 0.2H), 2.86 (dd, 1H), 3.04-3.11 (m, 1.8H), 3.72 (3H), 4.97 (d, 1H)
(2) ¹³ C-NMR (300 MHz, CDCl ₃ ) δ (ppm): 31.6, 33.9, 34.0, 51.9, 52.6, 73.7, 170.2, 171.1, 176.8
(3) GC-MS: m / z = 185, 171, 157, 125 (PDC dimethyl: m / z = 212, 181, 153, 125)
(4) IR (ν (cm ⁻¹ )): 2959 (—CH), 2858 (—CH ₂ —), 1750 (C═O of carboxylic acid), 1733 (C═O of lactone), 1444 (—CH ), 1062 (C-O)

Example 1: Production of polymer (polymethyl acrylate) by ring-opening polymerization of δ-valerolactone derivative (dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate) Obtained in Production Example 1 in a 10 ml eggplant type flask 1.0 g (4.6 mmol) of dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate (also referred to as dimethyl 6-oxotetrahydro-2H-pyran-2,4-dicarboxylate) and 2-ethyl 0.02 ml of tin hexanoate was added, and the reaction was stirred at room temperature. Thereafter, 0.01 ml of methanol was dropped, and the mixture was further heated for 1 hour and then dispersed in pure water. The precipitate was collected by filtration and dried under vacuum at 60 ° C. to obtain a transparent viscous solution-like methyl polyacrylate (0.57 g, yield 57%).

It was confirmed by ¹ H-NMR, ¹³ C-NMR, GPC, and IR measurement that polyester (polymethyl acrylate) was obtained by the above reaction.
(1) ¹ H-NMR (500 MHz, CDCl ₃ ) δ (ppm): 2.25-2.29 (m, terminal), 2.36-2.50 (m, main chain CH ₂ ), 2.58 -2.75 (m, main chain CH ₂ ), 2.81-2.94 (m, main chain CH), 3.00-3.15 (m, main chain), 3.69-3.81 ( m, side chain CH ₃ ), 4.21 (t, terminal), 4.98 (t, main chain CH) (from TMS)
(2) ¹³ C-NMR (500 MHz, CDCl ₃ ) δ (ppm): 31.5 (main chain CH ₂ ), 33.8 (main chain CH ₂ ), 34.0 (main chain CH, CH ₂ ), 52.3 (side _chain, CH _3), 73.7 (backbone CH), 170.5-171.4 (side chain C = O), 177.2 (side chain C = O), 182.6 ( Main chain C = O) (from TMS)
(3) GPC measurement: Mn = about 1045 (THF solvent)
(4) IR measurement (cm ⁻¹ ): 2965 (—CH ₂ —), 2911 (CH), 1736 (C═O), 1439 (CH), 1271 (CO), 1063 (CO)

Example 2: Preparation of polymer (methyl polyacrylate) by ring-opening polymerization of δ-valerolactone derivative (dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate) Obtained in Preparation Example 1 in a 10 ml eggplant type flask 0.64 g of the obtained dimethyltetrahydro-2H-pyrone-4,6-dicarboxylate (also called dimethyl 6-oxotetrahydro-2H-pyran-2,4-dicarboxylate) and tin 2-ethylhexanoate were changed to 0. .02 ml was added and reacted at 80 ° C. for 1.5 hours with stirring. Thereafter, 0.01 ml of methanol was added dropwise, and the mixture was further heated for 1 hour, and then the precipitate dispersed in pure water was collected by filtration, dried at 60 ° C. under vacuum, and methyl acrylate (0. 1143 g, 17% yield).
¹ H-NMR and ¹³ C-NMR measurement results were the same as those in Example 1. By GPC measurement, it was confirmed that Mn = about 4000 (THF solvent). Further, IR measurements ^{(cm -1)} _{is, 2972 (-CH 2 -),} 2876 (CH), 1734 (C = O), 1439 (CH), 1278 (CO), was 1066 (CO). Further, Tg (glass transition temperature) was −71 ° C. (measured at an increasing rate of 10 ° C./min), and the thermal decomposition temperatures were 130 ° C. (5 wt% weight reduction) and 261 ° C. (50 wt% weight reduction). It was.

  According to the method of the present invention, since a novel polyester can be produced by ring-opening polymerization of a δ-valerolactone derivative derived from 2-pyrone-4,6-dicarboxylic acid, the present invention provides a lignin that does not compete with food. Contributes to effective use of contained biomass.

Claims (4)

The following formula (1):

{In the formula, R ₁ is independently H or a monovalent alkyl group having 1 to 6 carbon atoms. } The polyester which has a repeating unit represented by these. The following formula (1):

{Wherein R ₁ is independently an aromatic group; or a heterocyclic group. } The polyester which has a repeating unit represented by these. The following formula (2):

The polyester which has a repeating unit represented by these. The following formula (3):

{Wherein, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; an aromatic group; or a terminal heterocyclic group. } Is polymerized in the presence of a catalyst to give the following formula (1):

{Wherein, R ₁ is independently H; a monovalent alkyl group having 1 to 6 carbon atoms; an aromatic group; or a terminal heterocyclic group. } The manufacturing method of polyester which has a repeating unit represented by these.