JP3410550B2 - Method for producing high molecular weight polyester - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a high molecular weight polyester, and more particularly to a method for producing a high molecular weight polyester by reacting a chain extender with an aliphatic polyester.

[0002]

2. Description of the Related Art Aliphatic polyesters are generally recognized to be biodegradable, and they are used alone or in combination with various additives to be formed into a sheet or film and used as a packaging material or the like. Among the physical properties of the aliphatic polyester, the mechanical properties are largely dependent on the polymer molecular weight. Therefore, various methods for producing a polyester having a molecular weight as high as possible have been studied and proposed.

As methods for producing such polyesters, the following methods 1) to 5) are known. Note that poly (hydroxyalkanoate) can be obtained by the methods described in 3) to 5). 1) Direct esterification of dicarboxylic acid and glycol or transesterification of alkyl ester of dicarboxylic acid and glycol to obtain glycol ester and / or low polymer thereof, which is then heated under high vacuum for a long time A method of stirring for polycondensation.

2) A method in which the polyester obtained in the above method 1) is reacted with a diisocyanate compound (JP-A-4-189822), and the polyester obtained in the above method 1) is reacted with a polyfunctional aziridine compound. Method (JP-A-62-257930), a method of reacting the polyester obtained by the method 1) with a polyfunctional epoxy compound (JP-A-57-42728).

3) A method of directly esterifying a hydroxycarboxylic acid. 4) Method using microorganisms (JP-A-56-117793). 5) Ring-opening polymerization of lactone (Japanese Patent Publication No. 56-746)
88, U.S. Pat. No. 3,111,469). However, in the method of 1) and 3) of heating and stirring under high vacuum for a long time to carry out polycondensation, the number average molecular weight of the polyester reached is 20,000 or less, and a polyester having a relatively high molecular weight is obtained. Therefore, a vacuum device for maintaining a high vacuum for a long time and high power are required, which is not industrially efficient. Furthermore, since melt polymerization of polyester is usually a high-temperature condensation reaction, side reactions (for example, thermal decomposition reaction) are likely to occur, it takes a long time to produce a high polymer, and a certain degree of polymerization occurs. On the contrary, there is a problem that the degree of polymerization is lowered. As a method for improving these points, a method by solid phase polymerization and a method using a polymerization accelerator (for example, diphenyl carbonate, diphenyl terephthalate, etc.) are well known. However, solid-phase polymerization is a method that emphasizes suppression of side reactions and sacrifices reaction rate to some extent, and requires a reaction for an extremely long time, and has the disadvantage of low productivity. Further, since a by-product such as phenol is produced, it is necessary to distill it out of the reaction system, and there is a drawback that it cannot be practically used unless the system is kept under reduced pressure.

According to the method 2), it is difficult to completely make the terminal of the polyester a carboxyl group or a hydroxyl group, so that the high molecular weight of the polyester becomes insufficient, or the terminal carboxyl group is contained in a large amount, so that the heat resistance becomes high. Will be insufficient. The method 4) requires strict control of the culture environment of the microorganism. Further, since a large amount of organic solvent must be used to extract the poly (hydroxyalkanoate) produced in the microorganism, poly (hydroxyalkanoate) cannot be synthesized at low cost.

In the method 5), first, a hydroxycarboxylic acid oligomer, which is a raw material for a lactone, is synthesized by condensation, the oligomer is pyrolyzed in the presence of a cyclization catalyst to synthesize a lactone, and the ring is further opened. Polymerization is extremely complicated and industrially disadvantageous, and poly (hydroxyalkanoate) cannot be synthesized at low cost.

[0008]

The problem to be solved by the present invention is to industrially and efficiently produce a high molecular weight polyester having a high melting point, excellent heat resistance and biodegradability in a short reaction time. is there.

[0009]

The method for producing a high molecular weight polyester of the present invention comprises at least one selected from the group consisting of phosphoric acid ester (b1) and phosphorous acid ester (b2).
It includes a preparatory step of preparing a chain extender comprising seeds, and a polymerization step of mixing the chain extender with the aliphatic polyester (A) and reacting them to obtain a high molecular weight polyester.

It is preferable that the polymerization step is a polymerization step in which the oxazoline compound (C) is mixed with the aliphatic polyester (A) in addition to the chain extender and reacted to obtain a high molecular weight polyester. The oxazoline compound (C)
Is preferably used in an amount of 0.01 to 5% by weight based on the aliphatic polyester (A).

The aliphatic polyester (A) is added to a cyclic acid anhydride containing succinic anhydride as a main component in a molten state or a solution state, the internal pressure of the reaction vessel is not less than atmospheric pressure, and the gauge pressure is 50 kgf / cm. While maintaining the ratio to ² or less, the cyclic ether mainly containing ethylene oxide is sequentially introduced at a rate of 3 to 90 parts by weight / hour with respect to 100 parts by weight of the cyclic acid anhydride to perform ring-opening copolymerization. It is more preferable that the obtained aliphatic polyester.

At least one selected from the phosphoric acid ester (b1) and the phosphorous acid ester (b2) is preferably used in a proportion of 0.01 to 5% by weight based on the aliphatic polyester (A). In the polymerization step, the reaction temperature is preferably 100 to 250 ° C. Further, the high molecular weight polyester of the present invention has the general formula (1) and / or (2) in the molecule.

[0013]

[Chemical 2]

(Wherein R represents a group containing an aliphatic polyester, and n represents an integer of 0 to 2), and has a number average molecular weight of 5,000 to 100,000. R of the high molecular weight polyester is preferably a group containing an aliphatic polyester obtained by the reaction of succinic anhydride and ethylene oxide. ******** The present invention is described in detail below.

Aliphatic polyester (A) used in the present invention
To obtain, a) a method of polycondensing a polybasic acid (or its ester) and glycol, (b) a method of polycondensing a hydroxycarboxylic acid (or its ester), c)
Examples thereof include a method of ring-opening polymerization of a cyclic acid anhydride and a cyclic ether. Examples of the polybasic acid used in the method b) include succinic acid, adipic acid, suberic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, octadecanedicarboxylic acid, dimer acid and esters thereof. Examples of the glycol include ethylene glycol,
Propylene glycol, 1,3-propanediol,
1,4-butanediol, neopentyl glycol,
Examples include 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol and the like. It is also possible to use polyoxyalkylene glycol (for example, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol and copolymers thereof) as a part of the glycol component. Of these, a combination of succinic acid and ethylene glycol and / or succinic acid and 1,4-butanediol is preferable in view of the melting point, biodegradability and economic efficiency of the obtained polyester. In the production of the aliphatic polyester (A), the polybasic acid (or ester thereof) component and the glycol component may all be initially mixed and reacted, or may be divided and added as the reaction progresses. Absent. The polycondensation reaction can be carried out by a usual transesterification method or an esterification method, or a combination of both methods. If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reaction vessel.

Examples of the hydroxycarboxylic acid used in the method (b) include glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxy-2,2-dimethylpropionic acid, 3-hydroxy-3-methyl-butyric acid. ,
Examples thereof include 4-hydroxybutyric acid, 5-hydroxyvaleric acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, citric acid, malic acid and their esters. The polycondensation reaction may be carried out by a usual transesterification method or an esterification method, or a combination of both methods. If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reaction vessel.

Examples of the cyclic acid anhydride used in the method (c) include succinic anhydride, maleic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride, phthalic anhydride and trimellitic anhydride. An acid is mentioned. You may use these cyclic acid anhydrides in mixture of 2 or more types. The proportion of succinic anhydride in the cyclic acid anhydride is preferably 50 mol% or more. In addition, the polybasic acid (ring-opened product of cyclic acid anhydride) in the cyclic acid anhydride is 2% or less,
It is preferably 0.5% or less. When the amount of polybasic acid in the cyclic acid anhydride increases, the molecular weight of the polyester tends to significantly decrease.

Examples of the cyclic ether used in the method (c) include ethylene oxide, propylene oxide, cyclohexene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, phenyl glycidyl ether, tetrahydrofuran, oxepane, 1,3-dioxolane. Is mentioned. You may use these ethers in mixture of 2 or more types. The proportion of ethylene oxide in the cyclic ether is preferably 50 mol% or more. Further, the content of glycol in the cyclic ether (the ring-opened product of the cyclic ether) is 2% or less, preferably,
It is 0.5% or less. As the amount of glycol in the cyclic ether increases, the molecular weight of the polyester tends to decrease significantly.

Considering the melting point, biodegradability and economic efficiency of the polyester obtained by the method (c), the combination of succinic anhydride and ethylene oxide is preferable as the cyclic acid anhydride and cyclic ether. The ring-opening polymerization can be carried out using a known ring-opening polymerization catalyst by a method such as polymerization in a solvent or bulk polymerization. Among the methods a) to c) for obtaining the aliphatic polyester (A) described above, ring-opening polymerization of a cyclic acid anhydride and a cyclic ether of c) is a method that can be industrially efficiently produced in a relatively short time. Is preferred. Less than,
The ring-opening polymerization of cyclic acid anhydride and cyclic ether will be described in more detail.

It has been known so far that the cyclic acid anhydride such as succinic anhydride used in the present invention does not homopolymerize. With respect to such a cyclic acid anhydride which does not homopolymerize, cyclic ethers are sequentially added and polymerized in the presence of a polymerization catalyst to produce a polyester in which an acid component and an alcohol component are substantially alternately copolymerized for a short time. Can be generated with.

The polymerization can be carried out by a method such as polymerization in a solvent or bulk polymerization. In the polymerization in a solvent, the cyclic acid anhydride is dissolved in the solvent before use. In the bulk polymerization, the cyclic acid anhydride is melted before use in the present invention. Polymerization in a solvent can be carried out batchwise or continuously, and examples of the solvent used for the polymerization reaction include benzene, toluene, xylene, cyclohexane, n-hexane, dioxane, chloroform and dichloroethane. A solvent can be used.

The polymerization catalyst is not particularly limited, and those usually used for ring-opening polymerization of polyester are used. For example, tetramethoxyzirconium, tetraethoxyzirconium, tetra-iso-propoxyzirconium, tetra-iso-butoxyzirconium, tetra-t-butoxyzirconium, triethoxyaluminum, tri-n-propoxyaluminum, tri-is.
o-propoxy aluminum, tri-n-butoxy aluminum, tri-iso-butoxy aluminum, tri-sec-butoxy aluminum, mono-sec-butoxy-di-iso-propoxy aluminum, ethyl acetoacetate aluminum diisopropylate, aluminum tris ( Ethyl acetoacetate), tetraethoxy titanium, tetra-iso-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-sec-butoxy titanium, tetra-t-.
Butoxy titanium, tri-iso-propoxy gallium,
Tri-iso-propoxyantimony, tri-iso-
Butoxyantimony, trimethoxyboron, triethoxyboron, tri-iso-propoxyboron, tri-n
-Propoxybolone, tri-iso-butoxybolone,
Tri-n-butoxyboron, tri-sec-butoxyborone, tri-t-butoxyborone, tri-iso-propoxygallium, tetramethoxygermanium, tetraethoxygermanium, tetra-iso-propoxygermanium, tetra-n-propoxygermanium, Metal alkoxides such as tetra-iso-butoxygermanium, tetra-n-butoxygermanium, tetra-sec-butoxygermanium, tetra-t-butoxygermanium; antimony pentachloride, zinc chloride, lithium bromide, tin chloride (IV), chloride Halides such as cadmium and boron trifluoride diethyl ether; trimethyl aluminum, triethyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride,
Alkyl aluminum such as tri-iso-butyl aluminum; alkyl zinc such as dimethyl zinc, diethyl zinc and diisopropyl zinc; tertiary amines such as triallylamine, triethylamine, tri-n-octylamine and benzyldimethylamine; phosphotungstic acid, phosphorus Examples thereof include heteropolyacids such as molybdic acid and silicotungstic acid, and alkali metal salts thereof; and the like, of which trialkoxyaluminum compounds are particularly preferable.

The amount of the polymerization catalyst used is not particularly limited,
Usually, it is 0.001 to 10% by weight based on the total amount of cyclic acid anhydride and cyclic ether. The polymerization catalyst may be added to the cyclic acid anhydride in advance, or may be sequentially added like cyclic ether. The polymerization temperature is not particularly limited as long as it is a temperature at which a cyclic acid anhydride and a cyclic ether react, but is 10 to 250 ° C, preferably 50 to 150 ° C, more preferably 100 to 150 ° C. Upon reaction,
The pressure in the reaction vessel varies depending on the reaction temperature, the presence or absence of a solvent, and the type of solvent, but the increase in unreacted cyclic ether due to the increase in pressure due to the sequential addition of cyclic ether is It is not desirable because it will increase. Therefore, the pressure inside the reaction vessel should be 50 kgf / cm ² or less as atmospheric pressure or gauge pressure (51 kg in absolute pressure).
f / cm ² or less), preferably 15 kgf / cm ² or less as atmospheric pressure or gauge pressure. The pressure in the reaction vessel may be maintained at a constant value within the above range, but usually, the cyclic ether is introduced so as to increase within the above range with the sequential introduction of the cyclic ether. Is good. Here, the pressure in the reaction vessel is an inert gas such as nitrogen substituted for the gas in the reaction vessel, the vapor of the solvent in which the cyclic acid anhydride is dissolved, the vapor of the volatilized cyclic ether, and the like in the reaction vessel. It is the total pressure obtained by summing each partial pressure.

Sequential addition of cyclic ether was carried out by adding 3 to 9 parts of cyclic ether to 100 parts by weight of cyclic acid anhydride per hour.
It is preferably 0 parts by weight, more preferably 5 to 50 parts by weight. When the addition rate of the cyclic ether is slower than the lower limit of 3 parts by weight, the reaction is prolonged and the productivity is lowered, which is not industrially preferable. On the other hand, when the content is higher than the upper limit of 90 parts by weight, the polyether component in the reaction product increases and only polyester having a low melting point can be obtained.

The sequential addition of the cyclic ether means that the cyclic ether is not added all at once, and either a continuous dropping method or a method of dividing the cyclic ether into multiple steps and intermittently adding the cyclic ether may be used. It is preferable to add continuously so that the added amount does not largely change with time. The reaction ratio of the cyclic acid anhydride and the cyclic ether in the present invention is preferably 40/60 to 60/40 in terms of the molar ratio, and the residual cyclic acid anhydride and the terminal carboxyl group of the polyester are Considering that the physical properties of the polyester are lowered, it is more preferable that the ratio is 40/60 to 49/51 in order to add the cyclic ether (C) in excess. By doing so, less than 50% of the terminal carboxyl groups of the polyester become carboxyl groups, and the heat resistance is improved.

If the ratio is out of this range, unreacted monomer may increase and the yield may decrease. In the present invention, it is preferable to continue the polymerization at the reaction temperature after the sequential addition of a predetermined amount of the cyclic ether determined in consideration of the molar ratio, and then to age it. The polyester produced from the polymerization system may be separated after the aging reaction, and the obtained polyester is further reacted with various chain extenders.

Reaction of the aliphatic polyester (A) with a chain extender comprising at least one selected from the group consisting of phosphoric acid ester (b1), phosphorous acid ester (b2) and polyvalent metal compound (b3). The method is not particularly limited, but a method in which the aliphatic polyester (A) is heated and melted and reacted with the chain extender under reduced pressure is preferable. The phosphoric acid ester (b1) used in the present invention may be any diester or triester as long as it is a phosphoric acid ester, and examples of the ester group include methyl, ethyl, propyl, butyl, phenyl, 2-ethylhexyl and the like. Responsiveness,
Considering economy, methyl, ethyl and phenyl are preferable. Among these, 1 type (s) or 2 or more types can be used.

The phosphite (b2) used in the present invention
May be a diester or triester as long as it is a phosphite, and examples of the ester group include methyl, ethyl, propyl, butyl, phenyl, 2-ethylhexyl, etc., but reactivity and economy are taken into consideration. Then, methyl, ethyl and phenyl are preferable. Among these, 1 type (s) or 2 or more types can be used.

At least one selected from the phosphoric acid ester (b1) and the phosphorous acid ester (b2) is used in a proportion of 0.001 to 10% by weight based on the aliphatic polyester (A). More preferably 0.01 to 5% by weight
Used in proportion. If the amount used is less than 0.001% by weight, the polyester will not have a sufficiently high molecular weight. When the amount is more than the upper limit of 10% by weight, unreacted phosphoric acid ester (b1) and phosphorous acid ester (b2)
Is more economically disadvantageous.

Polyvalent metal compound (b3) used in the present invention
Examples include organic compounds of divalent or higher valent metals, salts of metals and / or alkoxides of metals. Preferable metals of the organic compound of a metal having a valence of 2 or more and / or the salt of a metal include zinc, calcium, copper, iron, magnesium,
Examples include cobalt and barium. More preferably, after neutralization, zinc (II) acetylacetonate, zinc acetate, zinc formate, zinc propionate, zinc carbonate, etc. that can separate and recover the counter anion of the polyvalent metal compound (b3) as a volatile component from the reaction system. Is mentioned.

Examples of metal alkoxides include aluminum isopropyloxide, mono-sec-butoxyaluminum diisopropylate, aluminum ethylate, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetra (2-ethylhexyloxy) titanium and tetra. Stearyloxy titanium, tetra-n-butoxy zirconium, etc. may be mentioned.

The reaction method of the aliphatic polyester (A) and the polyvalent metal compound (b3) is not particularly limited, but a method of dissolving the polyester in a suitable solvent to react with the polyvalent metal compound (b3), or a polyester Examples thereof include a method of heating and melting and reacting with the polyvalent metal compound (b3).
The reaction ratio between the polyester and the polyvalent metal compound (b3) is not particularly limited, but in the case of a neutralization reaction between a carboxyl group at the terminal of the polyester and an organic compound of a metal having a valence of 2 or more and / or a salt of a metal, for example, a metal is used. Ratio of compound to carboxyl group of polyester (metal compound / C
The OOH (molar ratio)) is preferably 0.1 to 2.0, and more preferably 0.2 to 1.2. If the ratio is less than 0.1, the polyester will not have a sufficiently high molecular weight. On the other hand, when it is larger than 2.0, the amount of unreacted metal organic compound and metal salt increases, which is economically disadvantageous.

In the case of the reaction between the hydroxyl group at the terminal of the polyester and the metal alkoxide, for example, the ratio of the metal compound to the hydroxyl group of the polyester (metal compound / OH (molar ratio)) is 0.1 to 2.0. Is preferable, and 0.2
More preferably, it is 1.2. The ratio is 0.1
When it is smaller, the polyester does not have a sufficiently high molecular weight. On the other hand, if it is larger than 2.0, the amount of unreacted metal alkoxide increases, which is economically disadvantageous.

In the method for producing a high molecular weight polyester of the present invention, the reaction temperature in the polymerization step is preferably 20 to 300 ° C, more preferably 100 to 250 ° C. When the reaction temperature is 100 to 250 ° C, the high molecular weight polyester can be efficiently produced. The polymerization step is preferably a polymerization step in which the oxazoline compound (C) is mixed with the aliphatic polyester (A) in addition to the chain extender and reacted to obtain a high molecular weight polyester, and the reaction time is further shortened. The resulting high molecular weight polyester has excellent heat resistance and a high melting point.

The reaction method of the aliphatic polyester (A) and the oxazoline compound (C) is not particularly limited, but a method of dissolving the aliphatic polyester (A) in a suitable solvent and reacting it with the oxazoline compound (C), Examples include a method in which the aliphatic polyester (A) is melted by heating and reacted with the oxazoline compound (C). Examples of the oxazoline compound (C) used in the present invention include 2-oxazoline and 2
-Methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-butyl-2-oxazoline, 2-phenyl-2-oxazoline, 2,2'-bis- (2-oxazoline ), 2,
2'-methylene-bis- (2-oxazoline), 2,
2'-ethylene-bis- (2-oxazoline), 2,
2'-trimethylene-bis- (2-oxazoline),
2,2'-tetramethylene-bis- (2-oxazoline), 2,2'-hexamethylene-bis- (2-oxazoline), 2,2'-octamethylene-bis- (2-oxazoline), 2, 2'-ethylene-bis- (4,4 '
-Dimethyl-2-oxazoline), 2,2'-p-phenylene-bis- (2-oxazoline), 2,2'-m-
Phenylene-bis- (2-oxazoline), 2,2'-
Examples thereof include m-phenylene-bis- (4,4'-dimethyl-2-oxazoline), bis- (2-oxazolinylcyclohexane) sulfide, bis- (2-oxazolinylnorbornane) sulfide and the like. 1 of these
One kind or two or more kinds can be used.

The amount of the oxazoline compound (C) used is 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, based on the aliphatic polyester (A).
Aliphatic polyester (A) and oxazoline compound (C)
When the reaction ratio with is less than the lower limit of 0.001% by weight, the polyester does not have a sufficiently high molecular weight. Also,
If the amount is more than the upper limit of 10% by weight, the amount of unreacted oxazoline compound (C) increases, which is economically disadvantageous.
In order to accelerate the reaction between the polyester and the oxazoline compound (C), a known catalyst such as an amine salt of an acidic compound may be used if necessary.

The high molecular weight polyester of the present invention has the general formula (1) and / or (2) in the molecule.

[0038]

[Chemical 3]

(Wherein R is a group containing an aliphatic polyester and n is an integer of 0 to 2) and has a number average molecular weight of 5,000 to 100,000. Has a biodegradability, a high melting point, and excellent heat resistance. It can be easily molded into films and sheets and has excellent durability as a molded product.

In the general formula, R is a group containing an aliphatic polyester, and for example, the above aliphatic polyester (A) is preferable. When R is a group containing an aliphatic polyester obtained by the reaction of succinic anhydride and ethylene oxide,
Biodegradability and heat resistance are further excellent, which is preferable. The number average molecular weight of the high molecular weight polyester is 5,000 to 10,000.
It is 0. If the number average molecular weight is less than 5,000, it is difficult to use as a molded product, and the number average molecular weight is 100,000.
If it exceeds, biodegradability is low.

The number average molecular weight of the high molecular weight polyester is 2
When it is 0000 to 80,000, the heat resistance is excellent and the melting point is high, which is preferable. The production method of the high molecular weight polyester of the present invention is not particularly limited, and it can be produced by any production method. For example, the manufacturing method of the said high molecular weight polyester is mentioned.

The high molecular weight polyester of the present invention is excellent in heat resistance and has a high melting point, so that it can be easily molded into a film or sheet, and has excellent durability as a molded product. Therefore, the high molecular weight polyester obtained by the present invention can be effectively used for various applications such as disposable packaging materials and daily sundries.

[0043]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, "part" in an Example represents a "weight part." The evaluation methods carried out in the examples are as follows. The results are summarized in Table 1.

Evaluation Method (Molecular Weight) The number average molecular weight in terms of polystyrene was measured using a gel permeation chromatograph. (Melting point) Measured by DSC.

(Tensile test) 130 ° C., 150 kg / cm ² , 2
A film having a thickness of 200 μm was prepared by a compression molding machine under the condition of minutes, and a tensile test was conducted at a test speed of 20 mm / min in accordance with JIS K7121. (Biodegradability test) A film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² , and 2 minutes, and the obtained film was embedded in a soil-filled planter. Water once a day at 23 ° C, relative humidity 65%
The sample was stored in a constant temperature and humidity chamber and the change in appearance after 100 days was observed.

The soil used was that collected from Onohara in Minoh City and Nishiomitabi Town in Suita City, and a mixture of mulch at a ratio of 3: 1: 3. The results are shown below. (+): A change in appearance was observed. (-): No change in appearance was observed.

Example (Example 1) 386.2 succinic anhydride in an autoclave
Parts and 2.09 parts of aluminum isopropoxide were added, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 130 ° C. under stirring to melt the succinic anhydride,
At the same temperature, the pressure in the autoclave is 0 to 7.0 kgf / cm ²
187.0 parts of ethylene oxide were continuously introduced over a period of 2.5 hours at a rate of 75 parts per hour. After introducing ethylene oxide, a maturing reaction was carried out at 130 ° C. for 2.0 hours, and then the system was returned to room temperature to obtain a polymerization product. The procedure of dissolving the obtained polymerization product in chloroform and precipitating and purifying in tetrahydrofuran is described in 3
Repeated times to obtain polyester (1). The yield of this polyester (1) was determined to be 98.2%.
The number average molecular weight measured by GPC is 20500, D
The melting point by SC was 97.5 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was found to be 0.
It was 0434 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal was 44.5%.

3. The obtained polymerization product (100.0 parts) was heated and stirred in a nitrogen stream, and 2.30 'of 2,2'-m-phenylene-bis- (2-oxazoline) was added at 190 ° C. After reaction for 5 hours, the reaction product 70.
0 parts and 0.795 parts of diphenyl phosphite in a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D = 10.2) in a nitrogen stream from 1.8 to 100 rp under reduced pressure of 3.7 mmHg
m and a jacket temperature of 190 ° C. for 3.0 hours to obtain a high molecular weight polyester (1).

The number average molecular weight measured by GPC is 4,200.
0, the melting point by DSC was 99.8 ° C. The result of having measured the IR spectrum is shown in FIG. Also, 130 ℃,
150kg / cm ² , thickness 2 by compression molding machine under the condition of 2 minutes
A 00 micron film was prepared and the tensile strength and elongation were measured and found to be 210 kg / cm ² and 490%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (1) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. (Example 2) 375.9 succinic anhydride was placed in an autoclave.
Parts and 3.06 parts of aluminum isopropoxide were added, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 130 ° C. under stirring to melt the succinic anhydride,
The pressure in the autoclave is 0 to 10.2 kgf / cm at the same temperature.
While maintaining at ² , 192.1 parts of ethylene oxide was introduced continuously over 2.0 hours at an addition rate of 96 parts per hour. After introducing ethylene oxide, a maturing reaction was performed at 130 ° C. for 0.2 hours, and then the system was returned to room temperature to obtain a polymerization product. The operation of dissolving the obtained polymerization product in chloroform and precipitating and purifying in tetrahydrofuran was repeated 3 times to obtain a polyester (2). The yield of this polyester (2) was determined to be 99.1%. The number average molecular weight measured by GPC is 1800.
0, melting point by DSC was 95.9 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was 0.0401 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal was 36.
It was 1%.

3. The obtained polymerization product (100.0 parts) was heated and stirred in a nitrogen stream, and 2.10 parts of 2,2'-m-phenylene-bis- (2-oxazoline) was added at 190 ° C. After reaction for 5 hours, the reaction product 70.
0 part and 0.810 part of diphenyl phosphite were used in a nitrogen stream in a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D = 10.2) in a nitrogen stream of 1.7- 100 rp under reduced pressure of 3.5 mmHg
m and a jacket temperature of 190 ° C for 3.0 hours to obtain a high molecular weight polyester (2). The number average molecular weight measured by GPC is 36000, and the melting point measured by DSC is 9.
It was 8.2 ° C. Also, 130 ℃, 150kg / cm ² , 2
A film having a thickness of 200 μm was prepared by a compression molding machine under the condition of a minute, and the tensile strength and the elongation were measured and found to be 200 kg / cm ² and 480%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (2) was heated and stirred in a nitrogen stream at 190 ° C. for 2 hours and then GPC was measured, there was no change in the molecular weight. (Example 3) 2.30 parts of 2,2'-m-phenylene-bis- (2-oxazoline) of Example 1 was converted to 7.23 parts of bis (2-oxazolinylnorbornane) sulfide and the reaction time was 4. A high-molecular-weight polyester (3) was obtained in the same manner as in Example 1 except that 5 hours was changed to 1.0 hour. GP
The number average molecular weight measured by C was 39000, and the melting point measured by DSC was 97.5 ° C. Also, 130 ℃, 150kg
A film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of / cm ² and 2 minutes, and the tensile strength and elongation were measured and found to be 195 kg / cm ² and 420%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (3) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. (Example 4) 507.5 succinic anhydride was added to an autoclave.
And 2.74 parts of aluminum isopropoxide were added, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 135 ° C. under stirring to melt the succinic anhydride,
The pressure inside the autoclave is 3 to 12.6 kgf / cm at the same temperature.
While maintaining at ² , 270.2 parts of ethylene oxide were continuously introduced over a period of 9.0 hours at a rate of 30 parts per hour. After introducing ethylene oxide, a maturing reaction was performed at 135 ° C. for 1.0 hour and then the system was returned to room temperature to obtain a polymerization product. The operation of dissolving the obtained polymerization product in chloroform and precipitating for purification in tetrahydrofuran was repeated 3 times to obtain a polyester (3). The yield of this polyester (3) was determined to be 99.0%. The number average molecular weight measured by GPC is 1700.
0, melting point by DSC was 105.1 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was 0.0150 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal is 1
It was 2.8%.

70.0 parts of the obtained polyester (3) and 0.950 part of diphenyl phosphite were mixed with a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D = 10). 2) in a nitrogen stream,
Under a reduced pressure of 1.7 to 3.5 mmHg, the reaction was performed for 3.0 hours under the conditions of 100 rpm and a jacket temperature of 190 ° C. to obtain a high molecular weight polyester (4). The number average molecular weight measured by GPC is 46,000, and the melting point measured by DSC is 104.8.
It was ℃. In addition, a film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² and 2 minutes, and the tensile strength and the elongation were measured and found to be 2 respectively.
It was 20 kg / cm ² and 510%.

Further, in order to examine the heat resistance, when the high molecular weight polyester (4) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. Example 5 Succinic anhydride 386.2 was placed in an autoclave.
And 1.55 parts of zinc chloride were added, and the atmosphere was replaced with nitrogen. Then, the autoclave was gradually heated to 130 ° C. under stirring to melt the succinic anhydride, and 170.0 parts of ethylene oxide was added while maintaining the pressure inside the autoclave at 0 to 5.2 kgf / cm ^2. It was introduced continuously over a period of 2.0 hours at an addition rate of 85 parts per hour. After introducing ethylene oxide, a maturing reaction was performed at 130 ° C. for 1.3 hours, and then the system was returned to room temperature to obtain a polymerization product. The procedure of dissolving the obtained polymerization product in chloroform and precipitating for purification in tetrahydrofuran was repeated 3 times to obtain a polyester (4). The yield of this polyester (4) was determined to be 92.1%. The number average molecular weight measured by GPC is 12,500, and the melting point measured by DSC is 7.
It was 1.5 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was 0.0231 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal was 14.4%.

3. The obtained polymerization product (100.0 parts) was heated and stirred in a nitrogen gas stream, and 1.92 parts of 2,2'-m-phenylene-bis- (2-oxazoline) was added at 190 ° C. After reaction for 5 hours, the reaction product 70.
0 parts and 0.810 parts of diphenyl phosphite were mixed with a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D = 10.2) in a nitrogen stream at 1.3- 100 rp under reduced pressure of 3.5 mmHg
m and a jacket temperature of 190 ° C. for 3.0 hours to obtain a high molecular weight polyester (5). The number average molecular weight measured by GPC is 40,000, and the melting point measured by DSC is 7.
It was 2.5 ° C. Also, 130 ℃, 150kg / cm ² , 2
A film having a thickness of 200 μm was prepared by a compression molding machine under the condition of a minute, and the tensile strength and the elongation were measured and found to be 150 kg / cm ² and 380%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (5) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. (Example 6) Succinic anhydride 508.2 was placed in an autoclave.
Parts and 3.82 parts of titanium tetraisopropoxide were added, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 130 ° C. under stirring to melt the succinic anhydride,
At the same temperature, the pressure inside the autoclave is 0 to 7.2 kgf / cm ²
While maintaining the above value, 270.6 parts of ethylene oxide was continuously introduced over a period of 3.25 hours at an addition rate of 83 parts per hour. After introducing ethylene oxide, a maturing reaction was carried out at 130 ° C. for 2.0 hours, and then the system was returned to room temperature to obtain a polymerization product. The operation of dissolving the obtained polymerization product in chloroform and precipitating and purifying in tetrahydrofuran was repeated 3 times to obtain a polyester (5). The yield of this polyester (5) was determined to be 92.1%. The number average molecular weight measured by GPC is 1300.
0, the melting point by DSC was 90.0 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was 0.0320 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal was 20.
It was 8%.

3. 100.0 parts of the obtained polymerization product was heated and stirred in a nitrogen stream, and 2.66 parts of 2,2′-m-phenylene-bis- (2-oxazoline) was added at 190 ° C. to obtain 4. After reaction for 5 hours, the reaction product 70.
0 parts and 0.950 parts of diphenyl phosphite were mixed with a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D = 10.2) in a nitrogen stream at 1.1- 100 rp under reduced pressure of 3.9 mmHg
m and a jacket temperature of 190 ° C. for 3.0 hours to obtain a high molecular weight polyester (6). The number average molecular weight measured by GPC is 32,000, and the melting point measured by DSC is 9.
It was 0.2 ° C. Also, 130 ℃, 150kg / cm ² , 2
A film having a thickness of 200 μm was prepared by a compression molding machine under the condition of a minute, and the tensile strength and the elongation were measured and found to be 180 kg / cm ² and 400%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (6) was heated and stirred in a nitrogen stream at 190 ° C. for 2 hours and then GPC was measured, there was no change in the molecular weight. (Example 7) Diphenyl phosphite of Example 1 0.795
A high molecular weight polyester (7) was obtained in the same manner as in Example 1 except that 3.20 parts of triphenyl phosphite was used.
The number average molecular weight measured by GPC was 40500, and the melting point measured by DSC was 98.8 ° C. Also, 130 ° C, 15
0 kg / cm ² , thickness 200 by compression molding machine under the condition of 2 minutes
A micron film was prepared and the tensile strength and elongation were measured and found to be 215 kg / cm ² and 400%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (7) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. (Example 8) Diphenyl phosphite of Example 1 0.795
Example 1 except that 3.20 parts of triphenyl phosphate was used.
High molecular weight polyester (8) was obtained in the same manner as. G
The number average molecular weight measured by PC was 41500, and the melting point measured by DSC was 97.1 ° C. Also, 130 ℃, 150
A film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of kg / cm ² and 2 minutes, and the tensile strength and the elongation were measured and found to be 200 kg / cm ² and 395%, respectively.

Further, in order to examine the heat resistance, when the high molecular weight polyester (8) was heated and stirred in a nitrogen stream at 190 ° C. for 2 hours and then GPC was measured, there was no change in the molecular weight. Example 9 Polymerization product 100.0 obtained in Example 1
Part is heated and stirred in a nitrogen stream, and at 190 ° C 2,2'-m
-Phenylene-bis- (2-oxazoline) 2.30
Of the reaction product and 0.468 parts of diethyl phosphite were added to a self-cleaning twin-screw mixer (S1K manufactured by Kurimoto Iron Works Co., Ltd.).
RC reactor, inner diameter 25 mm, L / D = 10.2) in nitrogen stream under normal pressure, 100 rpm, jacket temperature 1
The reaction was carried out at 50 ° C. for 3.0 hours to obtain a high molecular weight polyester (9). The number average molecular weight measured by GPC is 3
0000, melting point by DSC was 96.8 ° C. Further, a film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² , and 2 minutes, and the tensile strength and the elongation were measured to be 175 kg / cm ² and 3 respectively.
It was 70%.

Further, in order to examine the heat resistance, when the high molecular weight polyester (9) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight. (Comparative Example 1) The polyester (1) obtained in Example 1 was heated and stirred at 190 ° C for 2 hours in a nitrogen stream, and the GPC was measured. The molecular weight was 10,000. Further, when polyester (1) was formed into a film having a thickness of 200 μm by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² and 2 minutes, it was brittle and tensile strength and elongation could not be measured.

Comparative Example 2 386.2 parts of succinic anhydride and 2.09 parts of aluminum isopropoxide were added to the autoclave, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 130 ° C. under stirring to melt the succinic anhydride, and the pressure in the autoclave is adjusted to 0 to 0 at the same temperature.
While maintaining at 15.0 kgf / cm ² , ethylene oxide 18
7.0 parts was added at an addition rate of 386.2 parts per hour.
It was introduced continuously for 5 hours. After introducing ethylene oxide, a maturing reaction was carried out at 130 ° C. for 2.0 hours, and then the system was returned to room temperature to obtain a polymerization product. The procedure of dissolving the obtained polymerization product in chloroform and performing precipitation purification in tetrahydrofuran was repeated 3 times to obtain a comparative polyester (1). The yield of this comparative polyester (1) was determined to be 82.6%. The number average molecular weight measured by GPC is 10500, and the melting point measured by DSC is 8.
It was 8.5 ° C.

(Example 10) 62.71 parts of the polymerized product obtained in Example 1 was heated and stirred in a nitrogen stream at 170 ° C.
Then, 1.79 parts of zinc (II) acetylacetonate was added and the reaction was carried out for 12 hours while maintaining the system at 5 to 10 mmHg to obtain a high molecular weight polyester (10). The number average molecular weight measured by GPC is 31,000, and the melting point measured by DSC is 97.8 ° C.
Met.

(Example 11) 386.2 parts of succinic anhydride and 1.67 parts of aluminum isopropoxide were added to an autoclave, and the atmosphere was replaced with nitrogen. Then, the autoclave is gradually heated to 130 ° C. under stirring to melt the succinic anhydride, and the pressure in the autoclave is adjusted to 0 to 0 at the same temperature.
While maintaining at 9.8 kgf / cm ² , ethylene oxide 204.
0 parts were continuously introduced in 1 hour. After introducing ethylene oxide, a maturing reaction was performed at 130 ° C. for 1.0 hour, and then the system was returned to room temperature to obtain a polymerization product. The obtained polymerization product was purified in the same manner as in Example 1 to produce polyester (1
1) was obtained. The yield of this polyester (11) was determined to be 98.3%. The number average molecular weight measured by GPC is 22,500, and the melting point measured by DSC is 97.8.
It was ℃.

69.6 parts of the obtained polymerization product was heated and stirred in a nitrogen stream, 1.29 parts of zinc (II) acetylacetonate was added at 170 ° C., and the system was kept at 5 to 10 mmHg for 11 hours. The reaction was carried out to obtain a high molecular weight polyester (11). Number average molecular weight measured by GPC is 29000, DS
The melting point according to C was 97.9 ° C. (Comparative Example 3) 250.0 succinic anhydride was added to an autoclave.
Parts, ethylene oxide 110.0 parts and toluene 200.
0 part was added, succinic anhydride was dissolved under stirring, and the atmosphere was sufficiently replaced with nitrogen. Next, after gradually raising the temperature of the autoclave to 80 ° C., 4.2 parts of aluminum isopropoxide was dissolved in 50 parts of toluene and added to the autoclave.
Polymerization was carried out at 0 ° C. for 4 hours. After completion of the polymerization, the system was returned to room temperature and toluene was distilled off to obtain a polymerization product.
The obtained polymerization product was purified in the same manner as in Example 1 to obtain a comparative polyester (3). The yield of this comparative polyester (3) was determined to be 78.5%. The number average molecular weight measured by GPC is 11,000, DS
The melting point according to C was 63.5 ° C.

(Example 12) 500.9 parts of succinic anhydride and 4.93 parts of tetra-t-butoxyzirconium were added to an autoclave, and the atmosphere was replaced with nitrogen. Then, the temperature of the autoclave was gradually raised to 130 ° C. with stirring to melt the succinic anhydride, and ethylene oxide 22 was added while maintaining the pressure in the autoclave at 0 to 8.4 kgf / cm ^2.
0.25 parts was continuously introduced over a period of 4.5 hours at an addition rate of 49 parts per hour. After introducing ethylene oxide 1
After performing an aging reaction at 30 ° C. for 3.0 hours, the system was returned to room temperature to obtain a polymerization product. The obtained polymerization product was purified in the same manner as in Example 1 to produce polyester (1
2) was obtained. The yield of this polyester (12) was determined to be 98.2%. The number average molecular weight measured by GPC is 18,000, and the melting point measured by DSC is 102.
It was 6 ° C. When the amount of carboxyl groups in the polyester was determined by neutralization titration, it was 0.0366 mmol / g. From the above measurement results, the ratio of the carboxyl group to the polyester terminal was 32.9%.

70.0 parts of the obtained polymerization product and 0.70 part of diphenyl phosphite were mixed with a self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 2).
5 mm, L / D = 10.2) in a nitrogen stream, 0.4-
A high molecular weight polyester (12) was obtained by reacting under a reduced pressure of 0.7 mmHg at 100 rpm and a jacket temperature of 240 ° C. for 1.5 hours.

The number average molecular weight measured by GPC is 5200.
0, melting point by DSC was 102.7 ° C. Also,
A film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² , and 2 minutes, and the tensile strength and elongation were measured, and were 300 kg / cm ² and 55, respectively.
It was 0%. Further, in order to examine the heat resistance, when the high molecular weight polyester (12) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight.

(Example 13) 70.0 parts of the polyester (12) obtained in Example 12 and 0.
70 parts of self-cleaning twin-screw mixer (S1KRC reactor manufactured by Kurimoto Iron Works Co., Ltd., inner diameter 25 mm, L / D)
= 10.2) under a reduced pressure of 0.4 to 0.6 mmHg in a nitrogen stream at 100 rpm and a jacket temperature of 240 ° C. for 2.0 hours to obtain a high molecular weight polyester (13).
Got

The number average molecular weight measured by GPC is 5000.
0, melting point by DSC was 101.9 ° C. Also,
A film having a thickness of 200 μm was formed by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² , and 2 minutes, and the tensile strength and the elongation were measured, respectively, to be 283 kg / cm ² and 49, respectively.
It was 0%. Furthermore, in order to examine the heat resistance, when the high molecular weight polyester (13) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight.

Example 14 70.0 parts of the polyester (12) obtained in Example 12 and 0.70 part of tetra-n-butoxyzirconium were mixed with a self-cleaning twin-screw mixer (Kurimoto Iron Works Co., Ltd.). S1KRC reactor, inner diameter 2
5 mm, L / D = 10.2) in a nitrogen stream, 0.2 to
Under a reduced pressure of 0.4 mmHg, the reaction was carried out for 2.2 hours under the conditions of 100 rpm and a jacket temperature of 240 ° C. to obtain a high molecular weight polyester (14).

The number average molecular weight measured by GPC is 5600.
0, melting point by DSC was 103.6 ° C. Also,
A film having a thickness of 200 μm was prepared by a compression molding machine under the conditions of 130 ° C., 150 kg / cm ² , and 2 minutes, and the tensile strength and the elongation were measured and found to be 270 kg / cm ² and 47, respectively.
It was 0%. Furthermore, in order to examine the heat resistance, when the high molecular weight polyester (14) was heated and stirred at 190 ° C. for 2 hours in a nitrogen stream and GPC was measured, there was no change in the molecular weight.

[0074]

[Table 1]

[0075]

The method for producing a high molecular weight polyester of the present invention comprises a preparatory step of preparing a chain extender comprising at least one selected from the group consisting of phosphoric acid ester (b1) and phosphorous acid ester (b2). According to the present invention, a high heat resistance, a high melting point and a biodegradability can be obtained because the chain extension agent is mixed with the aliphatic polyester (A) and reacted to obtain a high molecular weight polyester. The high molecular weight polyester having can be synthesized in a short reaction time.

In the polymerization step, when the oxazoline compound (C) is mixed with the aliphatic polyester (A) in addition to the chain extender and reacted, the reaction time can be further shortened, and the obtained high molecular weight polyester is Further, it has excellent heat resistance and a high melting point. Further, when it is used in an amount of 0.001 to 10% by weight with respect to the aliphatic polyester (A), the polymer has a sufficiently high molecular weight, which is economically advantageous.

The aliphatic polyester (A) was added to a cyclic acid anhydride containing succinic anhydride as a main component in a molten state or a solution state, the internal pressure of the reaction vessel was not less than atmospheric pressure, and the gauge pressure was 50 kgf / cm ² Obtained by sequentially introducing a cyclic ether containing ethylene oxide as a main component at a rate of 3 to 90 parts by weight per 100 parts by weight of a cyclic acid anhydride while maintaining the following, and performing ring-opening copolymerization. When the aliphatic polyester is obtained, the obtained high molecular weight polyester is obtained with high productivity, has excellent heat resistance, and has a high melting point.

When at least one selected from the phosphoric acid ester (b1) and the phosphorous acid ester (b2) is used in a proportion of 0.01 to 5% by weight with respect to the aliphatic polyester (A), it is sufficient. It has a high molecular weight and is economically advantageous. When the reaction temperature in the polymerization step is 100 to 250 ° C, the high molecular weight polyester can be produced more efficiently.

The high molecular weight polyester of the present invention has the structural units of the general formulas (1) and / or (2) in the molecule and has a number average molecular weight of 5,000 to 100,000, and therefore has biodegradability. It has excellent heat resistance and high melting point. It can be easily molded into films and sheets, and has excellent durability as a molded product. When R of the high molecular weight polyester is a group containing an aliphatic polyester obtained by the reaction of succinic anhydride and ethylene oxide,
Excellent biodegradability and heat resistance.

[Brief description of drawings]

FIG. 1 is a high-molecular-weight polyester (1) used in Example 1.
IR spectrum of.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-7-324125 (JP, A) JP-A-6-145313 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (8)

(57) [Claims] 1. A preparatory step of preparing a chain extender comprising at least one selected from the group consisting of a phosphoric acid ester (b1) and a phosphorous acid ester (b2); A) to obtain a high-molecular-weight polyester by reacting the mixture with the above-mentioned (1) to react. 2. The polymerization process according to claim 1, wherein the oxazoline compound (C) is mixed with the aliphatic polyester (A) in addition to the chain extender and reacted to obtain a high molecular weight polyester. A method for producing the high molecular weight polyester described. 3. The method for producing a high molecular weight polyester according to claim 2, wherein the oxazoline compound (C) is used in an amount of 0.001 to 10% by weight based on the aliphatic polyester (A). 4. The aliphatic polyester (A) is added to a cyclic acid anhydride containing succinic anhydride as a main component in a molten state or a solution state, the internal pressure of the reaction vessel is atmospheric pressure or more, and the gauge pressure is 50 kgf. The ring-opening copolymerization is carried out by sequentially introducing the cyclic ether containing ethylene oxide as a main component at a rate of 3 to 90 parts by weight per 100 parts by weight of the cyclic acid anhydride while maintaining the ratio to be not more than / cm ^2. The method for producing a high molecular weight polyester according to any one of claims 1 to 3, which is the aliphatic polyester obtained by the above. 5. At least one selected from phosphoric acid ester (b1) and phosphorous acid ester (b2) is used in a proportion of 0.01 to 5% by weight based on the aliphatic polyester (A). Item 5. A method for producing a high molecular weight polyester according to any one of Items 1 to 4. 6. The reaction temperature in the polymerization step is 100 to 25.
The method for producing a high molecular weight polyester according to any one of claims 1 to 5, which is 0 ° C. 7. A compound represented by the general formula (1) and / or (2) in the molecule: (In the formula, R is a group containing an aliphatic polyester, and n is 0.
Represents an integer from 2 to 2. ), And a high molecular weight polyester having a number average molecular weight of 5,000 to 100,000. 8. The high molecular weight polyester according to claim 7, wherein R of the high molecular weight polyester is a group containing an aliphatic polyester obtained by the reaction of succinic anhydride and ethylene oxide.