JP2968466B2 - Method for producing aliphatic polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an aliphatic polyester. More specifically, the present invention relates to a method for producing an aliphatic polyester having biodegradability and good moldability and suitable for, for example, fibers, molded articles, sheets, films and the like.

[0002]

2. Description of the Related Art Polyesters are used in various fields, and aromatic polyesters and aliphatic polyesters are properly used depending on applications. Aromatic polyesters are mainly used as films and molding materials.
Copolymers of aromatic polyesters and aliphatic polyesters are used as adhesives and paints, and block copolymers are used as thermoplastic elastomers in the production of various molded products.

In general, aliphatic polyesters are mainly used as raw materials for polyurethane, plasticizers for vinyl chloride, medical materials and the like. In addition, aliphatic polyesters
Since it has biodegradability, by taking advantage of its characteristics, by blending additives as necessary, fibers and molded products,
It is expected to be used as sheets, films and the like.

Conventionally, aliphatic polyesters have been produced by a method of directly esterifying an aliphatic dicarboxylic acid with an aliphatic glycol; a transesterification reaction between an alkyl ester of an aliphatic dicarboxylic acid and an aliphatic glycol. To synthesize the glycol ester and / or its prepolymer once, and then pressurize the compound under pressure.
A method of performing polycondensation with heating and stirring under high vacuum for a long time under a pressure of 0.4 mmHg to 1 mmHg has been practiced. In the above method, water is generated with the progress of the esterification reaction, and glycol is generated with the progress of the transesterification reaction.

However, according to the above-mentioned production method, only an aliphatic polyester having a number average molecular weight of less than 20,000 can be obtained. Further, JP-A-5-310898 discloses that an aliphatic dicarboxylic acid and an aliphatic glycol are used as catalysts,
There has been proposed a method for producing an aliphatic polyester by performing a glycol removal reaction (ester exchange reaction) under the conditions of a temperature of 180 ° C. to 230 ° C. and a pressure of 0.05 mmHg to 0.1 mmHg. JP-A-6-322081 discloses that aliphatic dicarboxylic acid and aliphatic glycol are used at a temperature of 240
C., pressure 1 mmHg or less, preferably 0.5 mmHg or less.
A method for producing an aliphatic polyester having (Mn) of 5,000 or more has been proposed.

[0006]

In the above manufacturing method,
Polycondensation is carried out for a long time under high vacuum while heating and stirring, so that a side reaction or a decomposition reaction of the aliphatic polyester easily occurs. That is, in the above production method, in addition to water and glycol, low-molecular-weight compounds such as by-products generated by side reactions and decomposed products (oligomers) generated by decomposition reactions,
That is, a large amount of volatile components is generated. These volatiles have little utility. Therefore, the above-mentioned conventional production method cannot produce an aliphatic polyester at low cost.

Further, when a large amount of volatile matter is generated, clogging easily occurs between the reactor (reaction vessel) and the trap. Therefore, the reaction must be frequently interrupted to remove the volatile matter. In addition, when the volatile components cannot be completely captured by the trap, a large amount of the volatile components flows into the vacuum pump, so that the degree of decompression is reduced (pressure is increased), and the performance of the vacuum pump is reduced and a failure is caused. . Therefore,
Inconveniences such as a significantly prolonged reaction time and the inability to obtain an aliphatic polyester having a predetermined molecular weight also occur.

In order to realize the above-mentioned high vacuum, a high-performance vacuum pump (hereinafter, referred to as a high-performance vacuum pump) is required. However, since the high-performance vacuum pump is expensive and a volatile component flows therein, a great deal of labor is required for maintenance and maintenance for maintaining the performance. Therefore, the above-mentioned conventional manufacturing method is hardly industrially implemented. Therefore, aliphatic polyester is industrially produced by using a general-purpose vacuum pump used in the production of saturated polyester such as polyethylene terephthalate (PET), that is, a vacuum pump having a degree of ultimate pressure reduction of about 0.5 mmHg, preferably about 1 mmHg. There is a long-felt need for a method capable of efficiently producing the same.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to polymerize at a reduced pressure such that a general-purpose vacuum pump can be used, and to carry out side reactions and decomposition. By suppressing the amount of volatile components generated by the reaction, it is possible to industrially, efficiently and economically produce an aliphatic polyester having biodegradability and having a higher melting point than in the past in a relatively short time. It is to provide a method.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for producing an aliphatic polyester in order to achieve the above object. As a result, a cyclic acid anhydride and a cyclic ether and / or a cyclic ester were produced. A polymer obtained by ring-opening polymerization in the presence of a catalyst, or a raw material of an aliphatic polyester, under a predetermined condition, the viscosity at the reaction temperature of the reaction system at the time of 0.1 to 30 hours after the start of the reaction Is 10 Poise to 100,000 Poise by performing polymerization while stirring, it is possible to polymerize at a reduced pressure such that a general-purpose vacuum pump can be used, and volatile components generated by side reactions and decomposition reactions By suppressing the amount of production, it is possible to industrially, efficiently and economically produce an aliphatic polyester having biodegradability and having a higher melting point than in the past in a relatively short time. And found that the present invention was completed.

That is, in order to solve the above-mentioned problems, the method for producing an aliphatic polyester according to the first aspect of the present invention is a method for producing an aliphatic polyester, which comprises 2 to 6 carbon atoms.
Aliphatic dicarboxylic acid and aliphatic glycos having 2 to 4 carbon atoms
And the raw material of the aliphatic polyester containing
Under the conditions of 80 ° C to 280 ° C and the reaction pressure of more than 1.0 mmHg to 5.0 mmHg, the viscosity at the reaction temperature of the reaction system becomes 100 poise to 50,000 po at 0.1 to 30 hours after the start of the reaction.
It is characterized by polymerizing under stirring so that the AS. According to a second aspect of the present invention, there is provided a method for producing an aliphatic polyester, wherein the raw material of the aliphatic polyester is an aliphatic dicarboxylic acid having 2 to 6 carbon atoms. It is characterized by containing an acid and ethylene glycol.

According to a third aspect of the present invention, there is provided a method for producing an aliphatic polyester, which comprises a method for producing an aliphatic polyester, comprising: a cyclic acid anhydride and a cyclic ether; The polymer obtained by subjecting the ester to ring-opening polymerization in the presence of a catalyst is further subjected to a reaction temperature of 180 ° C to 280 ° C and a reaction pressure of 0.3 mmHg to 5.0.
Under the conditions of mmHg, the viscosity of the reaction system at the reaction temperature at the time of 0.1 to 30 hours after the start of the reaction is 100 poise to 5
It is characterized in that polycondensation is carried out with stirring so as to have a viscosity of 0,000 poise . The aliphatic poly of the invention according to claim 4.
The method for producing the ester, in order to solve the above problems,
The method according to claim 1, 2 or 3, wherein the high viscosity
It is characterized by performing polycondensation using a reactor
You.

According to the above method, the polymerization can be carried out at a reduced pressure such that a general-purpose vacuum pump can be used, and the amount of volatile components generated by the side reaction or the decomposition reaction is suppressed. An aliphatic polyester having biodegradability and having a higher melting point than conventional ones can be produced industrially, efficiently and economically in a relatively short time.

Hereinafter, the present invention will be described in detail. The volatile matter in the present invention is defined as low amounts of excess raw materials, water generated by an esterification reaction, glycol generated by a transesterification reaction, by-products generated by a side reaction, and decomposition products generated by a decomposition reaction of an aliphatic polyester. 1 shows a compound having a molecular weight. The melting point in the present invention is a temperature determined by measuring the temperature in a nitrogen atmosphere at a rate of 6 K / min using a general thermal analyzer (differential scanning calorimeter). The viscosity in the present invention is JI
According to S K 7199, the diameter (inner diameter) of the capillary is 0.5 mm, and the ratio between the length and the diameter of the capillary (length / length)
It is a value at a shear rate of 100 s ^-1 which is determined by measuring the reaction temperature of the aliphatic polyester whose viscosity is to be measured as the measurement temperature under the condition of (diameter) = 20. still,
A measuring method of differential scanning calorimetry, that is, a method of obtaining a melting point will be described later.

As a method for producing an aliphatic polyester,
Specifically, for example, the following method can be mentioned. That is, (i) a polybasic acid (or an ester or an acid anhydride thereof);
(Ii) Polycondensation of aliphatic hydroxycarboxylic acid (or ester thereof) (iii) Ring-opening copolymerization of cyclic acid anhydride and cyclic ether (iv) Cyclic ester And the like, but the method is not particularly limited. still,
The raw materials of the aliphatic polyester include the above-mentioned polybasic acids, aliphatic glycols, aliphatic hydroxycarboxylic acids, cyclic acid anhydrides, cyclic ethers, cyclic esters, and other than these monomers used as necessary. (Which will be described later).

The polybasic acid used in the above method (i) includes difunctional or higher polycarboxylic acids or their esters and acid anhydrides; trifunctional or higher oxycarboxylic acids, etc., but is particularly limited. Not something. In order to produce an aliphatic polyester in which a polybasic acid and an aliphatic glycol are linearly bonded, a polybasic acid having two carboxyl groups in one molecule, that is, an aliphatic dicarboxylic acid or an ester thereof is used. preferable.

Examples of the above polybasic acids include, for example, aliphatic dicarboxylic acids such as succinic acid, adipic acid, suberic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, octadecanedicarboxylic acid, and dimer acid; And esters thereof; acid anhydrides such as succinic anhydride, maleic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride, phthalic anhydride, and trimellitic anhydride; pyromellitic dianhydride, benzophenone Tetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride, maleic anhydride homopolymer, maleic anhydride-vinyl acetate copolymer, maleic anhydride-
Polyfunctional acid anhydrides such as ethylene copolymer, maleic anhydride-isobutylene copolymer, maleic anhydride-isobutyl vinyl ether copolymer, maleic anhydride-acrylonitrile copolymer, maleic anhydride-styrene copolymer;
Examples thereof include trifunctional or more functional oxycarboxylic acids such as malic acid, tartaric acid, and citric acid, but are not particularly limited. These polybasic acids may be used alone, or two or more kinds may be appropriately mixed and used.

As the aliphatic glycol, specifically,
For example, ethylene glycol, propylene glycol,
Examples include 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol and the like. It is also possible to use a polyoxyalkylene glycol as a part of the aliphatic glycol. Specific examples of the polyoxyalkylene glycol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, and copolymers thereof. further,
As a part of the aliphatic glycol, it is also possible to use a trifunctional or higher polyhydric alcohol. Specific examples of the polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.

It is also possible to use a diepoxide as a part of the aliphatic glycol. As the diepoxide, specifically, for example, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl adipate, diglycidyl o-phthalate, diglycidyl terephthalate, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, glycerol diglycidyl ether, sorbitol polyglycidyl ether , Sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether Diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol triglycidyl ether, trimethylolpropane polyglycidyl ether, and the like. These aliphatic glycols may be used alone,
Further, two or more kinds may be appropriately mixed and used.

As the combination of the polybasic acid and the aliphatic glycol, an aliphatic dicarboxylic acid having 2 to 6 carbon atoms and a carbon A combination with aliphatic glycols of formulas 2 to 4 is preferred, and a combination of succinic acid with ethylene glycol and / or 1,4-butanediol is more preferred.

In the method (i), the polybasic acid and the aliphatic glycol may be mixed and then polycondensed, or the polybasic acid and / or the fatty acid may be added as the reaction proceeds. A group glycol may be added to the reaction system for polycondensation.

The polycondensation in the method (i) can be carried out by a usual transesterification reaction or esterification reaction, or a combination of these reactions. Also,
If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reactor (reaction system). Furthermore, after performing a normal esterification reaction, a transesterification reaction may be performed to improve the degree of polymerization. In this case, the distinction between the esterification reaction and the transesterification reaction in the polycondensation need not be clear.

In the above-mentioned transesterification and esterification, a catalyst is used. Specific examples of the catalyst include, for example, titanium, germanium, zinc, iron, manganese, cobalt, zirconium, hafnium, vanadium, iridium, lanthanum, cerium, lithium, calcium, magnesium, tin, barium, nickel, and the like. Organic metal compounds containing at least one metal selected from the group, organic acid salts, metal alkoxides, metal oxides, metal hydroxides, carbonates, phosphates, sulfates, nitrates, and chlorides, and the like. The catalyst is not particularly limited, and a known catalyst can be used. These catalysts may be used alone or in combination of two or more. The above-mentioned catalyst is used in such a manner that the proportion thereof relative to 100 parts by weight of the obtained aliphatic polyester is 0.001 to 5 parts by weight, preferably 0.01 to 0.5 parts by weight. When the esterification reaction by dehydration condensation and the transesterification reaction are used in combination, the esterification reaction can be performed using a catalyst after the esterification reaction is performed without using a catalyst.

As the aliphatic hydroxycarboxylic acid used in the above method (ii), specifically, for example,
Glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxy-2,2-dimethylpropionic acid, 3-hydroxy-
3-methylbutyric acid, 4-hydroxybutyric acid, 5-hydroxyvaleric acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, citric acid, malic acid, esters thereof and the like Is mentioned. These aliphatic hydroxycarboxylic acids may be used alone,
Further, two or more kinds may be appropriately mixed and used.

The polycondensation in the method (ii) can be carried out by a usual transesterification reaction or esterification reaction, or a combination of these reactions. Also,
If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reactor (reaction system).

The cyclic acid anhydride used in the above method (iii) is not particularly limited as long as it has at least one acid anhydride group in one molecule. Incidentally, in order to produce an aliphatic polyester in which a cyclic acid anhydride and a cyclic ether are linearly bonded, one molecule has one acid anhydride group per molecule.
A cyclic acid anhydride having two or more is preferred.

Specific examples of the cyclic acid anhydride include, for example, the compounds exemplified above, ie, succinic anhydride,
Acid anhydrides such as maleic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride, phthalic anhydride, trimellitic anhydride; pyromellitic dianhydride;
Benzophenonetetracarboxylic dianhydride, butane-1,
2,3,4-tetracarboxylic dianhydride, maleic anhydride homopolymer, maleic anhydride-vinyl acetate copolymer, maleic anhydride-ethylene copolymer, maleic anhydride-isobutylene copolymer, maleic anhydride Examples thereof include polyfunctional acid anhydrides such as acid-isobutyl vinyl ether copolymer, maleic anhydride-acrylonitrile copolymer, and maleic anhydride-styrene copolymer. These cyclic acid anhydrides may be used alone, or two or more kinds may be appropriately mixed and used.

From the viewpoints of the melting point, biodegradability, economy and the like of the aliphatic polyester obtained, a cyclic acid anhydride containing succinic anhydride as a main component is more preferable. Further, the proportion of succinic anhydride in the cyclic acid anhydride is preferably at least 50 mol%, more preferably at least 80 mol%. When the proportion of succinic anhydride is less than 50 mol%, the resulting aliphatic polyester tends to have a low melting point and a low biodegradability.

The proportion of the ring-opened product in the cyclic acid anhydride, that is, the proportion of the ring-opened product of the cyclic acid anhydride is preferably 2% by weight or less, more preferably 1% by weight or less, and 0.5% by weight or less. Is more preferred. When the ratio of the ring-opened cyclic anhydride is 2
If the amount is more than 10% by weight, the number average molecular weight (Mn) of the aliphatic polyester obtained is undesirably reduced.

The cyclic ether used in the above method (iii) is not particularly limited as long as it has at least one epoxy group in one molecule. In order to produce an aliphatic polyester in which a cyclic acid anhydride and a cyclic ether are linearly bonded, one epoxy group is contained in one molecule.
The cyclic ether having two or more is preferable.

Specific examples of the above cyclic ether include, for example, ethylene oxide, propylene oxide,
Cyclohexene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, phenyl glycidyl ether, tetrahydrofuran, oxepane, 1,
3-dioxolane; (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, diglycidyl adipate, diglycidyl o-phthalate, diglycidyl terephthalate, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, glycerol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol Polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidide Ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol triglycidyl ether, trimethylolpropane polyglycidyl ether, and the like. These cyclic ethers may be used alone, or two or more kinds may be appropriately mixed and used.

From the viewpoints of the melting point, biodegradability, economy and the like of the aliphatic polyester obtained, a cyclic ether containing ethylene oxide as a main component is more preferable. The proportion of ethylene oxide in the cyclic ether is preferably at least 50 mol%, more preferably at least 80 mol%. If the proportion of ethylene oxide is less than 50 mol%, the melting point of the resulting aliphatic polyester tends to be low, and the biodegradability tends to be low.

The ratio of the ring-opened product in the cyclic ether, that is, the ratio of the ring-opened product of the cyclic ether is preferably 2% by weight or less, more preferably 1% by weight or less, and further preferably 0.5% by weight or less. The ratio of ring-opened products of cyclic ethers is 2
If the amount is more than 10% by weight, the number average molecular weight of the aliphatic polyester obtained is undesirably reduced.

Accordingly, as a combination of a cyclic acid anhydride and a cyclic ether, a combination of a cyclic acid anhydride containing succinic anhydride as a main component and a cyclic ether containing ethylene oxide as a main component is preferable. Most preferred is the combination with ethylene oxide.

If necessary, other monomers copolymerizable with these monomers may be added to the above-mentioned cyclic acid anhydride and cyclic ether as long as the effects of the present invention are not impaired. it can. Specific examples of the other monomer include cyclic esters such as β-butyrolactone, pivalolactone, ε-caprolactone, δ-valerolactone, glycolide, and lactide; ethylene sulfide, propylene sulfide, propane sultone, and propane. Cyclic sulfur compounds such as sultam; ε-caprolactam, ω-caprylactam, ethyleneimine, 2-phenyloxazoline,
Examples thereof include cyclic nitrogen compounds such as succinimide; cyclic carbonates such as ethylene carbonate, but are not particularly limited. These other monomers may be used alone or in combination of two or more.

Specific examples of the cyclic ester used in the method (iv) include, for example, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, ε-caprolactone, glycolide , Lactide and the like. These cyclic esters may be used alone, or two or more kinds may be appropriately mixed and used.

The ring-opening polymerization in the above methods (iii) and (iv) can be carried out by a reaction such as polymerization in a solvent or bulk polymerization using a known catalyst (ring-opening polymerization catalyst).

Specific examples of the above catalyst include, for example, tetramethoxy zirconium, tetraethoxy zirconium, tetra-iso-propoxy zirconium, tetra-iso-butoxy zirconium, tetra-n-butoxy zirconium, tetra-t-butoxy Alkoxy zirconium (zirconium compound) such as zirconium; zirconium acid chloride, zirconyl propionate, zirconyl octylate, zirconyl 2-ethylhexanoate, zirconyl stearate, zirconyl nitrate, zirconyl hydroxide, zirconyl carbonate, zirconyl phosphate, zirconyl sulfate, Oxyzirconium salts (zirconium compounds) such as zirconyl ammonium carbonate; metallocene compounds such as zirconocene dichloride (zirconium compound) and titanocene dichloride; triethoxyaluminum Aluminum, tri-n-propoxyaluminum, tri-iso-propoxyaluminum,
Tri-n-butoxyaluminum, tri-iso-butoxyaluminum, tri-sec-butoxyaluminum, mono-
sec-butoxy-di-iso-propoxyaluminum, ethyl acetoacetate aluminum diisopropylate,
Aluminum tris (ethylacetoacetate), tetraethoxytitanium, tetra-iso-propoxytitanium, tetra-n-propoxytitanium, tetra-n-butoxytitanium, tetra-sec-butoxytitanium, tetra-t-butoxytitanium, tri-iso -Propoxygallium, tri-iso-propoxyantimony, tri-iso-butoxyantimony,
Trimethoxyboron, triethoxyboron, tri-iso-
Propoxyboron, tri-n-Propoxyboron, tri-
iso-butoxyboron, tri-n-butoxyboron, tri-
sec-butoxyboron, tri-t-butoxyboron, tri-
iso-propoxygallium, tetramethoxygermanium, tetraethoxygermanium, tetra-iso-propoxygermanium, tetra-n-propoxygermanium, tetra-iso-butoxygermanium, tetra-n-butoxygermanium, tetra-sec-butoxygermanium, tetra- Metal alkoxides such as t-butoxygermanium; metal halides such as antimony pentachloride, zinc chloride, lithium bromide, tin (IV) chloride, cadmium chloride, boron trifluoride diethyl ether; trimethylaluminum, triethylaluminum, diethylaluminum chloride , Ethyl aluminum dichloride, tri-is
alkylaluminums such as o-butylaluminum; alkylaluminum derivatives such as polymethylaluminoxane and polyisobutylaluminoxane; alkylzincs such as dimethylzinc, diethylzinc and diisopropylzinc; triallylamine, triethylamine, tri-n-octylamine, benzyldimethylamine Tertiary amines; heteropolyacids such as tungstophosphoric acid, molybdophosphoric acid, and tungstosilicic acid, and alkali metal salts thereof; and the like, but are not particularly limited, and a known catalyst can be used.

Among the above exemplified catalysts, a zirconium compound and a trialkoxyaluminum are more preferred. Among zirconium compounds, tetraalkoxyzirconium and oxyzirconium salts are more preferable. Among the oxyzirconium salts, zirconyl 2-ethylhexanoate, zirconyl carbonate and zirconyl hydroxide are particularly preferred. By using a zirconium compound, an aliphatic polyester having a higher molecular weight can be produced.

The above catalyst has a ratio of 0.001% by weight to 10% by weight, more preferably 0.01% by weight to 5% by weight, still more preferably 0.1% by weight to 1% by weight, based on the total amount of the cyclic acid anhydride and the cyclic ether. %, But is not particularly limited. The method for adding the catalyst is not particularly limited. For example, the catalyst may be added to a cyclic acid anhydride or may be added sequentially.

Of the above methods (i) to (iv), the method (iii) is preferable because the aliphatic polyester can be industrially and efficiently produced in a relatively short time. The following (ii
The method i) will be described in more detail.

It has been known that cyclic acid anhydrides such as succinic anhydride do not homopolymerize. The inventors of the present invention have proposed a method in which a cyclic ether is added to a cyclic acid anhydride in the presence of a catalyst, for example, by sequentially adding the cyclic ether to carry out ring-opening polymerization. Group polyesters can be produced in a relatively short time.

The ring-opening polymerization can proceed by a reaction such as polymerization in a solvent or bulk polymerization. In the polymerization in a solvent, the cyclic acid anhydride may be dissolved or suspended in a solvent before use. Polymerization in a solvent can be performed either in a batch system or a continuous system. In the bulk polymerization, the cyclic acid anhydride may be melted and used.

As the above-mentioned solvent, specifically, for example, benzene, toluene, xylene, cyclohexane,
n-hexane, n-octane, dioxane, chloroform,
And inert solvents such as dichloroethane. These solvents may be used alone or as a mixture of two or more.

The cyclic ether is used in an amount of 3 to 90 parts by weight, preferably 5 to 50 parts by weight, more preferably 14 to 50 parts by weight, per 100 parts by weight of the cyclic anhydride. It is added sequentially in parts by weight. If the amount added per hour is less than 3 parts by weight, a long time is required for the reaction and productivity is lowered, which is industrially disadvantageous. If the amount added per hour is more than 90 parts by weight, the amount of the polyether component in the reaction product increases and the melting point of the aliphatic polyester decreases, which is not preferable. Here, "added sequentially" means that the cyclic ether is not mixed with the cyclic acid anhydride at once. As a method of sequentially adding, for example, a method of continuously adding (dropping) a cyclic ether to a reaction system, and adding a cyclic ether to a reaction system intermittently in several times (dropping)
And the like. Among them, the method of continuously adding (dropping) is preferable because the amount of addition does not largely change over time.

The molar ratio between the cyclic acid anhydride and the cyclic ether (cyclic acid anhydride / cyclic ether) is 40/60 to 60/40.
Is preferably within the range. The terminal carboxyl group of the aliphatic polyester, and the cyclic acid anhydride remaining in the aliphatic polyester, considering that the physical properties of the aliphatic polyester is reduced, the above molar ratio is such that the cyclic ether becomes excessive. More preferably, it is in the range of 40/60 to 49/51. By reacting the cyclic acid anhydride with the cyclic ether at a molar ratio within this range, the ratio of the terminal of the aliphatic polyester to a carboxyl group can be reduced to less than 50%. The weight loss start temperature increases, and the heat resistance improves. If the molar ratio is outside the above range, the unreacted cyclic acid anhydride or cyclic ether increases, and the yield of the aliphatic polyester decreases.

The reaction time may be set according to the combination of the cyclic acid anhydride and the cyclic ether, the reaction temperature, the reaction pressure, the presence or absence and the type of the solvent, the time required for the addition of the cyclic ether, and the like, and is particularly limited. Not something.

In the above ring-opening polymerization, it is preferable that a predetermined amount of a cyclic ether set based on the molar ratio is sequentially added, and then the reaction system is aged at the reaction temperature for a predetermined time. The produced aliphatic polyester can be easily separated from the reaction system.

Further, in order to further reduce the amount of generated volatile components, it is more preferable to employ a production method including ring-opening polymerization in which water and glycol are not generated.

Next, polybasic acids and aliphatic glycols,
The method for polycondensing an aliphatic hydroxycarboxylic acid in the presence of a catalyst is described in further detail.

In the above method, the volatile matter generated by the polycondensation may be 25% by weight or less, preferably 20% by weight or less, more preferably 10% by weight or less based on the raw materials. Thereby, the aliphatic polyester can be industrially manufactured at low cost. When the volatile content exceeds 25% by weight, as described above, a decrease in the degree of pressure reduction (increase in pressure) of the reaction system and a decrease in the performance of the vacuum pump are caused.
Therefore, there are disadvantages such as an extremely long reaction time and an inability to obtain an aliphatic polyester having a predetermined molecular weight.

The reaction conditions are not particularly limited. However, when the method (i) is employed, and after the cyclic acid anhydride and the cyclic ether are subjected to ring-opening copolymerization by employing the method (iii), the transesterification reaction is further performed to obtain an aliphatic ester. When increasing the molecular weight of the polyester, the reaction temperature of the transesterification reaction is preferably from 180 to 280 ° C, more preferably from 235 to 280 ° C. Also, the reaction pressure,
In other words, the degree of decompression depends on the amount of volatile matter generated, but 0.3 mm
Hg to 5.0 mmHg is preferred, 0.5 mmHg to 3.0 mmHg is more preferred, and 1.0 mmHg to 2.0 mmHg is even more preferred. If the reaction temperature is lower than 180 ° C., the reaction time is undesirably prolonged. When the reaction temperature is higher than 280 ° C., a large amount of volatile components is generated and the aliphatic polyester is colored, which is not preferable. If the degree of pressure reduction is less than 0.3 mmHg, that is, if the reaction pressure is less than 0.3 mmHg, a large amount of low-molecular-weight compounds (volatiles) such as by-products generated by side reactions and decomposed products generated by decomposition reactions Generate. Therefore, the reaction time becomes extremely long,
Problems such as the inability to obtain an aliphatic polyester having a predetermined molecular weight occur. Moreover, it is not preferable because aliphatic polyester cannot be produced at low cost. Decompression degree
If it is larger than 5.0mmHg, that is, the reaction pressure is 5.0mmHg
If the amount exceeds g, the reaction time becomes extremely long, which is not preferable.

That is, in the method of polycondensing a raw material of an aliphatic polyester in the presence of a catalyst, an esterification reaction (hereinafter, referred to as a first-stage reaction) is performed, followed by a transesterification reaction (hereinafter, referred to as a second-stage reaction). In the method, the following reaction conditions are preferable. That is, the reaction temperature of the first-stage reaction is preferably 180 ° C to 280 ° C. The degree of reduced pressure in the first-stage reaction is preferably from 1.0 mmHg to normal pressure. The reaction temperature of the second-stage reaction is preferably 180 ° C to 280 ° C. The degree of reduced pressure in the latter reaction is preferably 0.3 mmHg to 5.0 mmHg. By performing the first-stage reaction, the number average molecular weight is at least 5,000
The above polymer is obtained. In addition, an aliphatic polyester having a number average molecular weight of 10,000 to 100,000 can be obtained by performing the latter-stage reaction.

In the method of ring-opening copolymerizing a cyclic acid anhydride and a cyclic ether, the following reaction conditions are preferred. That is, the reaction temperature is preferably from 10 ° C to 250 ° C,
C. to 150.degree. C. is more preferable, and 100.degree. The reaction pressure is, and the reaction temperature varies depending on the presence or absence of a solvent and the type or the like, normal pressure to 50 kgf / cm ² are preferred,
Normal pressure to 15 kgf / cm ² is more preferable. By performing ring-opening copolymerization, industrially high value, the number average molecular weight is 10,000
The above aliphatic polyester can be efficiently obtained in one step. In order to maintain the above reaction pressure, the cyclic ether is desirably added to the cyclic acid anhydride sequentially. If the reaction pressure is higher than 50 kgf / cm ^2,
That is, it is not preferable to add a large amount of the cyclic ether because unreacted cyclic ethers are bonded to each other to form a polyether chain.

Further, as a result of intensive studies by the present inventors,
Among the impurities contained in the cyclic acid anhydride or the cyclic ether, substances having active hydrogen such as free acids, water, alcohols and aldehydes are the main causes (factors) for reducing the number average molecular weight of the aliphatic polyester. Clarified that. The inventors have found that the number-average molecular weight of the aliphatic polyester can be increased by removing the above substances as much as possible and increasing the purity of the cyclic acid anhydride and the cyclic ether. The purity of the cyclic acid anhydride and the cyclic ether is determined by a general method, for example, distillation,
It can be increased by recrystallization, crystallization and the like.

Therefore, in the method of ring-opening copolymerizing a cyclic acid anhydride and a cyclic ether, the purity of both compounds is reduced.
When the content is 99.0% by weight or more, preferably 99.5% by weight or more, an aliphatic polyester having a number average molecular weight of 20,000 or more can be obtained. In the present invention, as the purity, a numerical value calculated by measuring the amount of impurities contained in the cyclic acid anhydride or the cyclic ether and subtracting the value of the impurities (% by weight) from the whole (100% by weight) is used. (% By weight).

In order to increase the number average molecular weight of the aliphatic polyester, for example, the inside of the reactor is sufficiently dried and purged with nitrogen to obtain a raw material having a purity as high as possible.
It is desirable to carry out ring-opening copolymerization under a nitrogen stream using a catalyst, a solvent and the like.

When any of the above methods (i) to (iv) is adopted, an aliphatic polyester having a number average molecular weight of 10,000 or more can be obtained. Incidentally, regarding the reaction apparatus suitably used in the method for producing an aliphatic polyester according to the present invention,
The details will be described later. When the obtained aliphatic polyester has a number average molecular weight of less than 10,000, or when a higher molecular weight is desired, a normal transesterification reaction is further performed on the aliphatic polyester to increase the molecular weight. Alternatively, the molecular weight may be increased by reacting with various chain extenders (crosslinking agents).

Examples of the above chain extender include isocyanate compounds, epoxy compounds, aziridine compounds,
An oxazoline compound, a polyvalent metal compound, a polyfunctional acid anhydride, a phosphoric ester, a phosphite and the like can be mentioned. These chain extenders may be used alone or as a mixture of two or more. The reaction temperature when reacting the aliphatic polyester with the chain extender is from 20 ° C.
250 ° C is preferred, and 100 ° C to 200 ° C is more preferred. Further, as a reaction method of the aliphatic polyester and the chain extender, for example, after dissolving the aliphatic polyester in an appropriate solvent, a method of reacting with the chain extender, or after heating and melting the aliphatic polyester, A method of reacting with a chain extender may be mentioned, but is not particularly limited.

The above isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule. Specific examples of the isocyanate compound include, for example, tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, xylylene diisocyanate, and meta-xylylene diisocyanate. Isocyanate compounds such as nate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate; Sumidur N (trade name, Sumitomo Bullet polyisocyanate compound such as Bayer Urethane Co., Ltd .; Desmodur IL, HL (trade name: Bayer AG)
Polyisocyanate compounds having an isocyanurate ring such as Coronate EH (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.); Sumidur L (trade name, manufactured by Sumitomo Bayer Urethane Co., Ltd.), Coronate HL
Adduct polyisocyanate compound (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.). Further, a block isocyanate compound can also be used. These isocyanate compounds may be used alone or in combination of two or more.

The ratio of the aliphatic polyester and the isocyanate compound in the urethanization reaction is not particularly limited. For example, the ratio between the isocyanate group of the isocyanate compound and the terminal of the aliphatic polyester The molar ratio to the hydroxyl group (isocyanate group / hydroxyl group) is preferably in the range of 0.5 to 3.0, and more preferably in the range of 0.8 to 1.5. In order to accelerate the urethanization reaction, a known urethanization catalyst such as an organotin compound or a tertiary amine may be used, if necessary.

The epoxy compound is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule. Specific examples of the epoxy compound include (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcin diglycidyl ether, and neopentyl glycol diglycidyl ether. , 1,6-hexanediol diglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, glycerol diglycidyl ether, sorbitol polyglycidyl Ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether , Diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol triglycidyl ether, trimethylolpropane polyglycidyl ether, and the like. These epoxy compounds may be used alone or in combination of two or more.

The method for reacting the aliphatic polyester with the epoxy compound is not particularly limited. In order to accelerate the above reaction, a known catalyst such as a tertiary amine, a quaternary ammonium salt, or an imidazole compound may be used, if necessary. Alternatively, when the aliphatic polyester is produced, an epoxy compound may coexist. That is, the cyclic acid anhydride, the cyclic ether, and the epoxy compound may be subjected to ring-opening polymerization. In addition, these three reaction products
An epoxy compound may be further reacted.

As the aziridine compound, specifically, for example, 2,2′-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], ethylene glycol-bis [3- (1-aziridinyl) ) Propionate], polyethylene glycol-bis [3- (1-aziridinyl) propionate], propylene glycol-bis [3- (1-aziridinyl) propionate], polypropylene glycol-bis [3- (1-aziridinyl) propionate], tetra Methylene glycol-bis [3-
(1-aziridinyl) propionate], polytetramethylene glycol-bis [3- (1-aziridinyl) propionate], N, N′-tetramethylenebisethylene urea,
N, N'-pentamethylenebisethylene urea, N, N'-hexamethylene bisethylene urea, N, N'-heptamethylene bisethylene urea, N, N'-octamethylene bisethylene urea, N, N'-phenylene Bisethylene urea, N, N'-toluylene bisethylene urea, N, N'-diphenyl-4,4'-bisethylene urea, 3,3'-dimethyldiphenyl-4,4'-bisethylene urea, 3, Examples include 3′-dimethoxydiphenyl-4,4′-bisethyleneurea, diphenylmethane-p, p-bisethyleneurea, but are not particularly limited. These aziridine compounds may be used alone or in combination of two or more. The above aziridine compound is
It is used in an amount of 0.001% to 10% by weight, more preferably 0.01% to 5% by weight, based on the aliphatic polyester.

As the oxazoline compound, specifically, for example, 2-oxazoline, 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'-m-phenylene-bis- (4,4 ' -Dimethyl-2-oxazoline), bis-
Examples thereof include (2-oxazolinylcyclohexane) sulfide and bis- (2-oxazolinyl norbornane) sulfide, but are not particularly limited. These oxazoline compounds may be used alone or in combination of two or more. Of the oxazoline compounds exemplified above, 2,2′-m-phenylene-bis- (2-oxazoline) and bis- (2-oxazolinylnorbornane) sulfide are particularly preferred.

The ratio of the aliphatic polyester and the oxazoline compound when they are reacted is not particularly limited. For example, the ratio between the 2-oxazoline group of the oxazoline compound and the terminal carboxyl group of the aliphatic polyester may be reduced. The molar ratio (2-oxazoline groups / carboxyl groups) is preferably in the range of 0.5 to 10.0, and 0.8 to 5.0.
Is more preferable. In order to accelerate the above reaction, a known catalyst such as an amine salt of an acidic compound may be used, if necessary.

The above polyvalent metal compound includes, for example,
Examples thereof include, but are not particularly limited to, organometallic compounds containing divalent or higher-valent metals, metal salts, and metal alkoxides. Suitable metals for the organometallic compounds and metal salts include, for example, zinc, calcium, copper, iron, magnesium, cobalt, barium and the like. Among the organometallic compounds and metal salts containing these metals, zinc
(II) Acetylacetonate, zinc acetate, zinc formate, zinc propionate, zinc carbonate and the like are particularly preferred. After neutralizing the organic zinc compound and the zinc salt with the aliphatic polyester, the reaction solution is neutralized, whereby the counter anion of the zinc compound can be separated and recovered as a volatile component from the reaction solution. As the metal alkoxide, specifically, for example, aluminum isopropoxide, mono-se
c-butoxyaluminum diisopropylate, aluminum ethylate, tetraisopropoxytitanium, tetra
-n-butoxytitanium, tetra (2-ethylhexyloxy) titanium, tetrastearyloxytitanium and the like. These polyvalent metal compounds may be used alone,
Further, two or more kinds may be used in combination.

The ratio of the aliphatic polyester and the polyvalent metal compound when they are reacted is not particularly limited. For example, the polyvalent metal compound may be an organometallic compound and / or a metal salt (hereinafter referred to as an organic salt). When described as a metal compound or the like), the molar ratio of the organometallic compound or the like and the terminal carboxyl group of the aliphatic polyester (organometallic compound or the like / carboxyl group) is preferably in the range of 0.1 to 2.0, More preferably, it is in the range of 0.2 to 1.2. Further, for example, when the polyvalent metal compound is a metal alkoxide, the molar ratio of the metal alkoxide to the terminal hydroxyl group of the aliphatic polyester (organometallic compound / hydroxyl group)
Is preferably in the range of 0.1 to 2.0, and 0.2 to 1.2
Is more preferable.

Specific examples of the above polyfunctional acid anhydride include the compounds exemplified above, but are not particularly limited. These polyfunctional acid anhydrides may be used alone or in combination of two or more. The above polyfunctional anhydride is used in an amount of 0.0
It is used in an amount of from 01% by weight to 10% by weight, more preferably from 0.01% by weight to 5% by weight.

The method of reacting the aliphatic polyester with the polyfunctional acid anhydride is not particularly limited. Alternatively, when producing the aliphatic polyester, a polyfunctional acid anhydride may be allowed to coexist. That is, a cyclic acid anhydride, a cyclic ether, and a polyfunctional acid anhydride may be subjected to ring-opening polymerization. Further, a polyfunctional anhydride may be further reacted with the reaction product of the three.

The above-mentioned phosphate ester and phosphite ester may be any of diester and triester. Examples of the ester group include a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, a 2-ethylhexyl group and the like. Among these ester groups, a methyl group, an ethyl group, and a phenyl group are more preferable in consideration of reactivity, economy, and the like. These phosphate esters and phosphite esters may be used alone or in combination of two or more. The above phosphoric acid ester and / or phosphite is present in an amount of 0.001% by weight to 10% by weight, more preferably 0.01% by weight to 5% by weight, based on the aliphatic polyester.
Used to be.

By reacting with the above chain extender,
It is possible to further increase the molecular weight of the aliphatic polyester.

The aliphatic polyester obtained by the above method has a number average molecular weight of 10,000 to 100,000. In consideration of thermal degradation and strength, the number average molecular weight of the aliphatic polyester is preferably 25,000 or more, and more preferably 40,000 or more. If the number average molecular weight is less than 10,000, there may be an industrial problem that the film becomes brittle when formed into a film or cannot be stretched. Aliphatic polyesters having a number average molecular weight of 100,000 or more are industrially disadvantageous because the reaction requires a long time. In addition, if the reaction requires a long time, the volatile components generated by the decomposition of the aliphatic polyester and the like increase, so that the number average molecular weight of the aliphatic polyester is preferably 80,000 or less, more preferably 70,000 or less. That is, the number average molecular weight of the aliphatic polyester is more preferably from 25,000 to 80,000, even more preferably from 40,000 to 70,000.

Next, a reaction apparatus suitably used in the method for producing an aliphatic polyester according to the present invention will be described.

The reaction apparatus is not particularly limited, and a reaction temperature of 180 ° C. to 280 ° C., and more preferably 235 ° C. to 280 ° C., is used for reacting a raw material of the aliphatic polyester (or a polymer obtained by ring-opening polymerization). , And reaction pressure 0.3mmHg ~
Under the condition of 5.0 mmHg, the viscosity at the reaction temperature of the reaction system is 10 poise to 10
What is necessary is just to have a structure which can be polymerized (polycondensed) with stirring so as to have a molecular weight of 0,000 poise, more preferably 100 poise to 50,000 poise. More preferably,
Under the above conditions, the reaction apparatus is used for 0.5 hours to 10 hours after the start of the reaction.
After the lapse of time, the viscosity of the reaction system at the reaction temperature becomes 10
Poise to 100,000 poise, more preferably 100 poise to 5
What is necessary is just to have a structure which can be polymerized while stirring so as to have a viscosity of 0,000 poise. As the above-mentioned reaction device, for example, a known reaction device such as a vertical reaction device or a horizontal reaction device, a so-called high-viscosity reaction device can be used.

When stirring to satisfy the above conditions,
The surface (free surface) of the contents (reaction system) in the reactor is frequently updated. That is, since the total surface area per unit time with respect to the volume of the content can be significantly increased, an extremely wide gas-liquid contact surface can be secured.
Therefore, volatile components generated as the polymerization reaction proceeds can be easily volatilized from the contents.

In order to satisfy the above conditions, for example, when a flask or a reaction vessel equipped with a general stirring device is used as a vertical reactor, the raw materials to be charged into the reactor, that is, the contents The amount may be relatively small. Further, by using a reaction vessel provided with a helical ribbon blade or a spiral deformed baffle as the stirring device, the stirring can be performed more efficiently. Further, by using a horizontal single-shaft kneading device (horizontal reactor) having one stirring shaft with a series of deformed blades or a horizontal twin-shaft kneading device having two stirring shafts in parallel with each other. It can be efficiently stirred.

The high viscosity reactor may be of a batch type or a continuous type. Specific examples of the batch type reactor include, for example, Super Blend (manufactured by Sumitomo Heavy Industries, Ltd.), an inverted conical ribbon blade reactor (manufactured by Mitsubishi Heavy Industries, Ltd.), and a twisted lattice blade reactor (Hitachi, Ltd.) Manufactured by Seisakusho). Specific examples of the continuous reaction apparatus include, for example, Hitachi Glasses Blade Polymerizer (manufactured by Hitachi, Ltd.), Hitachi Lattice Blade Polymerizer (manufactured by Hitachi, Ltd.), and a self-cleaning reactor (Mitsubishi Heavy Industries, Ltd.) ), Horizontal two-axis reactor (Mitsubishi Heavy Industries, Ltd.), KRC kneader (Kurimoto, Ltd.), TEX-K (Japan Steel Works, Ltd.), or extrusion or devolatilization of plastic And the like.

The reaction apparatus is not limited to the above-described apparatus. The above reaction apparatus can be suitably used for the reaction between an aliphatic polyester and a chain extender.

The above-mentioned aliphatic polyester may be added, if necessary, to a nucleating agent, a pigment, a dye, a heat-resistant agent, an antioxidant, a weathering agent, a lubricant, an antistatic agent, a stabilizer, a filler, a reinforcing material. Further, additives such as a flame retardant and a plasticizer, or other polymers can be added within a range that does not impair the effects of the present invention. Specific examples of the other polymer include a polyolefin such as polyethylene and an aromatic polyester, but are not particularly limited.

The aliphatic polyester has biodegradability,
Good moldability. The aliphatic polyester can be applied to known molding methods such as extrusion molding, injection molding, hollow molding, vacuum molding and the like, and is used for molded parts such as various parts and containers, materials, and tools, fibers, films, sheets, and the like. It is suitable.

[0082]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. In the examples and comparative examples, "parts" indicates parts by weight.

The number average molecular weight and the melting point of the aliphatic polyester were measured by the following methods. In addition, a biodegradation test of an aliphatic polyester was performed by the method described below.

(Number Average Molecular Weight) The number average molecular weight (Mn) of the aliphatic polyester was measured using a gel permeation chromatograph under the following conditions.

Measurement conditions Apparatus: HLC-8020 manufactured by Tosoh Corporation Column: Shodex K- manufactured by Showa Denko KK
805, 804, 803, 802 Eluent: chloroform Flow rate: 1 ml / min Temperature: 40 ° C. Detector: RI The number average molecular weight is a value in terms of polystyrene.

(Melting point) Melting point of aliphatic polyester (° C.)
Was measured in a nitrogen atmosphere using a differential scanning calorimeter (SSC5200, manufactured by Seiko Instruments Inc.). The measurement conditions were as follows: the sample amount was 20 mg, the sample was heated to completely melt, then rapidly cooled to −50 ° C., and then heated at a heating rate of 6 K / min. Then, an endothermic peak was measured, and this temperature was defined as a melting point.

(Biodegradability Test) First, an aliphatic polyester was molded using a compression molding machine at a molding temperature of 130 ° C. and a molding pressure of 15 ° C.
Molded under the conditions of 0 kg / cm ² and molding time of 2 minutes, thickness 200
A μm film was prepared. On the other hand, an artificial soil was prepared by mixing the soil collected from Onohara in Minoh City, the soil collected in Nishiburi-cho, Suita City, and humus in a weight ratio of 3: 1: 3,
This artificial soil was put into a planter.

Then, the above-mentioned film is embedded in the artificial soil, and once a day, a predetermined amount of water is sprinkled, and the temperature is adjusted to 23.
The samples were stored for 100 days in a constant temperature and humidity room set at 65 ° C. and a relative humidity of 65%. Thereafter, the film was taken out and the change in appearance was observed.

However, in the column of “biodegradability” in the following table, a case where a change in the appearance of the film is recognized, that is, a case where the biodegradability is recognized is described as (+), and the appearance of the film is described. Is described as (-) when no change is observed, that is, when no biodegradability is observed.

Example 1 The first-stage reaction was carried out using a three-necked flask (reactor) equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a Vigreux column (vigreux column). The Vigreux fractionating tube was connected to a general-purpose vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol).

After the above three-necked flask was charged with 120.08 parts of succinic anhydride as a polybasic acid and 76.63 parts of ethylene glycol as an aliphatic glycol, the three-necked flask was immersed in an oil bath. Next, the content was gradually heated to 185 ° C. under a nitrogen stream while stirring. Subsequently, the polycondensation was carried out for 52 hours while maintaining the temperature in the three-necked flask at 185 ° C., the degree of vacuum at 1.5 mmHg to normal pressure, and distilling off generated water and excess ethylene glycol. Thereafter, the reaction system was cooled to room temperature. As a result, an aliphatic polyester having a number average molecular weight of 6,000 was obtained.

Next, a second-stage reaction was carried out using a 50-ml separable flask (reactor) equipped with a thermometer, a stirrer, a nitrogen inlet tube and a suction tube. After 10.79 parts of the aliphatic polyester and 0.0004 parts of tetra-n-butoxytitanium as a catalyst were charged into the separable flask, nitrogen substitution was performed three times. Further, the above suction tube was connected to a general-purpose vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol). Next, while stirring the contents, the mixture was reacted at 240 ° C. for more than 1.0 mmHg to 1.1 mmHg under a nitrogen stream under a nitrogen stream for 5.0 hours to obtain a high molecular weight aliphatic polyester.

The number average molecular weight of the aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, is 65,000.
With a melting point of 104.6 ° C and a viscosity at 240 ° C
It was 830 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, in the second-stage reaction, the total amount of the volatile matter trapped in the trap and the volatile matter attached to the upper part of the separable flask (hereinafter referred to as the second-stage reaction volatile matter) is determined by the amount of the aliphatic polyester (10.79 parts) Was 7.2% by weight. Table 1 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

[Example 2] The first-stage reaction was carried out using the same three-necked flask as that of Example 1. After 200.14 parts of succinic anhydride, 248.28 parts of ethylene glycol and 0.36 part of tetra-n-butoxytitanium were charged into the three-necked flask, the three-necked flask was immersed in an oil bath. Next, while stirring the contents, under a nitrogen stream
Heated gradually to 200 ° C. Subsequently, the polycondensation was carried out for 17 hours while maintaining the temperature in the three-necked flask at 200 ° C., the degree of vacuum at 10.0 mmHg to normal pressure, and distilling off generated water and excess ethylene glycol. Thereafter, the reaction system was cooled to room temperature. Thereby, an aliphatic polyester having a number average molecular weight of 5,500 was obtained.

Next, a second-stage reaction was carried out using the same separable flask as in Example 1. In the separable flask, place the aliphatic polyester 1
After charging 0.10 part and tetra-n-butoxytitanium 0.0079 part, nitrogen substitution was performed three times. Then, while stirring the contents, under a nitrogen stream, the degree of vacuum 1.1 mmHg to 1.2 mmHg, 24
By reacting at 0 ° C. for 3.5 hours, an aliphatic polyester having a high molecular weight was obtained.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, has a number average molecular weight of 74,000.
With a melting point of 104.1 ° C and a viscosity at 240 ° C
It was 1,100 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, the volatile content of the second-stage reaction was 9.6% by weight based on the charged aliphatic polyester (10.10 parts). Table 1 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Example 3 The first-stage reaction was carried out using an autoclave equipped with a thermometer, a stirrer, and a nitrogen inlet tube. After the above autoclave was charged with 100.1 parts of succinic anhydride and 2.99 parts of zirconyl 2-ethylhexanoate as a catalyst, the autoclave was purged with nitrogen. Next, the content was gradually heated to 130 ° C. while stirring to melt the succinic anhydride. Next, the temperature in the autoclave is
While maintaining the temperature at 130 ° C. and the pressure at 4.0 kgf / cm ^{2 to} 8.1 kgf / cm ² , the reaction system was continuously charged with 231.26 parts of ethylene oxide as a cyclic ether at a rate of 42 parts per hour for 5.5 hours (sequentially). ). After completion of the addition, an aging reaction (ring-opening copolymerization) was further performed at 130 ° C. for 1.0 hour, and then the reaction system was cooled to room temperature. This allows
An aliphatic polyester was obtained. The number average molecular weight of the aliphatic polyester was 11,400 and the melting point was 103.1 ° C.

Next, a second-stage reaction was carried out using the same separable flask as in Example 1. In the separable flask, the aliphatic polyester 9.
After charging 67 parts, nitrogen replacement was performed three times. Then, while stirring the contents, under a nitrogen stream, the degree of decompression is more than 1.0 mmHg.
By reacting at 1.2 mmHg and 240 ° C. for 3.0 hours, an aliphatic polyester having a high molecular weight was obtained.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, had a number average molecular weight of 63,400.
With a melting point of 103.5 ° C and a viscosity at 240 ° C
It was 820 poise. In addition, biodegradability was observed in the aliphatic polyester. Furthermore, the second-stage reaction volatiles are based on the charged aliphatic polyester (9.67 parts).
It was 5.9% by weight. Table 1 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Example 4 First, the same pre-stage reaction as in Example 3 was carried out to obtain an aliphatic polyester.
Next, a second-stage reaction was performed using the same separable flask as in Example 1. After charging 9.69 parts of the above aliphatic polyester into the above separable flask, nitrogen substitution was performed three times. Then, while stirring the contents, under a nitrogen stream, the degree of pressure reduction was 2.1 mmHg to 2.2 mmHg, 240
Reaction was carried out at 3.1 ° C. for 3.1 hours to obtain an aliphatic polyester having a high molecular weight.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, has a number average molecular weight of 57,500.
With a melting point of 103.5 ° C and a viscosity at 240 ° C
It was 600 poise. In addition, biodegradability was observed in the aliphatic polyester. Furthermore, the second-stage reaction volatile component is based on the charged aliphatic polyester (9.69 parts).
It was 5.2% by weight. Table 1 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Comparative Example 1 First, the same pre-stage reaction as in Example 3 was performed to obtain an aliphatic polyester.
Next, a second-stage reaction was performed using the same separable flask as in Example 1. After charging 10.37 parts of the above aliphatic polyester into the above separable flask, nitrogen substitution was performed three times. Then, while stirring the contents, under a nitrogen stream, the degree of vacuum was 0.09 mmHg to 0.18 mmHg, 2
The reaction was carried out at 40 ° C. for 3.2 hours to obtain a comparative aliphatic polyester having a high molecular weight.

The number average molecular weight of the obtained aliphatic polyester for comparison was 65,300, the melting point was 103.3 ° C.,
The viscosity at ° C was 825 poise. The comparative aliphatic polyester was found to have biodegradability. Further, the second-stage reaction volatile component was 20.9% by weight based on the charged aliphatic polyester (10.37 parts). Table 1 shows the above measurement results and test results. However, in the latter reaction, the vacuum line was often clogged during the reaction due to the high volatile content. Therefore, the reaction must often be interrupted to remove volatiles trapped in the trap and volatiles clogged in the vacuum line.

[0104]

[Table 1]

Example 5 The first-stage reaction was carried out using an autoclave (reactor) equipped with a thermometer, a stirrer, and a nitrogen inlet tube. Into the above autoclave, 500.0 parts of succinic anhydride and 2- (a zirconium compound) as a catalyst were added.
After charging 3.68 parts of zirconyl ethylhexanoate, the atmosphere was replaced with nitrogen. The succinic anhydride was purified by distillation and used.

Next, the contents were gradually heated to 130 ° C. with stirring to melt the succinic anhydride. Next, the temperature in the autoclave was set to 130 ° C and the pressure was set to 4.0 kgf.
while maintaining ^{/ cm 2 ~6.5 kgf / cm 2} , the reaction system, the 231.1 parts of ethylene oxide at a rate of 58 parts per hour 4.0
The addition was continuous (sequential) over time. After completion of the addition, an aging reaction (ring-opening copolymerization) was further performed at 130 ° C. for 1.0 hour, and then the reaction system was cooled to room temperature. Thus, an aliphatic polyester was obtained. The aliphatic polyester has a number average molecular weight of 36,000 and a melting point of 103.4 ° C.
Met.

Next, a second-stage reaction was carried out using a 50-ml separable flask (reactor) equipped with a thermometer, a stirrer, a nitrogen inlet tube and a suction tube. After 12.0 parts of the above aliphatic polyester was charged into the above separable flask, nitrogen substitution was performed three times. Further, the above suction tube was connected to a general-purpose vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol). Then, while stirring the contents, under a nitrogen stream, the degree of vacuum 0.9
A transesterification reaction was performed at mmHg to 1.1 mmHg at 240 ° C for 1.5 hours to obtain an aliphatic polyester having a high molecular weight. The total reaction time is 6.5 hours.

The number average molecular weight of the obtained aliphatic polyester, that is, the aliphatic polyester having a high molecular weight, is 68,000.
With a melting point of 103.2 ° C and a viscosity at 240 ° C
It was 930 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, the second-stage reaction volatile matter was 0.48 parts. The volatile content throughout the entire reaction (the first-stage reaction and the second-stage reaction) was 4.0% by weight based on the charged raw materials (500.0 parts of succinic anhydride and 231.1 parts of ethylene oxide). Table 2 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Example 6 The first-stage reaction and the second-stage reaction of Example 5 except that 3.68 parts of zirconyl 2-ethylhexanoate in Example 5 were replaced by 3.70 parts of tetra-t-butoxyzirconium as a catalyst. The same first-stage reaction and second-stage reaction as those described above were performed to obtain an aliphatic polyester.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, had a number average molecular weight of 65,000.
With a melting point of 103.5 ° C and a viscosity at 240 ° C
It was 830 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, the second-stage reaction volatile component was 0.60 part. And the volatiles throughout
It was 5.0% by weight based on the charged raw materials. Table 2 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Example 7 The first-stage reaction was carried out using the same autoclave as in Example 5. After the autoclave was charged with 500.0 parts of succinic anhydride and 3.68 parts of zirconyl 2-ethylhexanoate, the atmosphere was replaced with nitrogen. In addition, the said succinic anhydride used the commercial item as it was.

Next, the content was gradually heated to 130 ° C. with stirring to melt the succinic anhydride. Next, the temperature in the autoclave was set to 130 ° C. and the pressure was set to 4.0.
while maintaining ^{kgf / cm 2 ~8.5 kgf / cm} 2, the reaction system, the 231.1 parts of ethylene oxide were added continuously over 4.0 hours at a rate of 58 parts per hour (sequential). After completion of the addition, an aging reaction (ring-opening copolymerization) was further performed at 130 ° C. for 1.0 hour, and then the reaction system was cooled to room temperature. Thus, an aliphatic polyester was obtained. The number average molecular weight of the aliphatic polyester is 13,000
And the melting point was 104.4 ° C.

Next, a second-stage reaction was carried out using the same separable flask as that of Example 5. In the separable flask, the aliphatic polyester 1
After charging 2.0 parts, nitrogen replacement was performed three times. Then
While stirring the contents, under a nitrogen stream, the degree of decompression is 0.5mmHg ~
A transesterification reaction was performed at 0.6 mmHg and 240 ° C. for 3.0 hours to obtain an aliphatic polyester having a high molecular weight. The total reaction time is 8.0 hours.

The number average molecular weight of the aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, is 62,000.
With a melting point of 101.9 ° C and a viscosity at 240 ° C
It was 760 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, the second-stage reaction volatile matter was 1.92 parts. And the volatiles throughout
It was 16.0% by weight based on the charged raw materials. Table 2 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Example 8 First, the same pre-stage reaction as in Example 7 was carried out to obtain an aliphatic polyester.
Next, a second-stage reaction was performed using the same separable flask as that of Example 5. After 12.0 parts of the above aliphatic polyester was charged into the above separable flask, nitrogen substitution was performed three times. Then, while stirring the content, under a nitrogen stream, the degree of vacuum was reduced from 0.3 mmHg to 0.4 mmHg, 240 mmHg.
A transesterification reaction was performed at 3.0 ° C. for 3.0 hours to obtain a high molecular weight aliphatic polyester. The total reaction time is 8.0 hours.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight, had a number average molecular weight of 65,000.
With a melting point of 102.8 ° C and a viscosity at 240 ° C
It was 840 poise. In addition, biodegradability was observed in the aliphatic polyester. Further, the volatile content of the latter-stage reaction was 2.61 parts. And the volatiles throughout
It was 21.8% by weight based on the charged raw materials. Table 2 shows the above measurement results and test results. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

Comparative Example 2 A reaction was carried out using a three-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube, and a Vigreux fractionating tube. The Vigreux fractionating pipe is
It was connected to a general-purpose vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol).

In the above three-necked flask, succinic acid 47.2 was added.
Parts, 46.9 parts of tetramethylene glycol and 0.026 parts of magnesium acetate tetrahydrate, and then the three-necked flask was immersed in an oil bath. Next, the contents were gradually heated to 200 ° C. under a nitrogen stream while stirring. Next, the polycondensation was performed for 3 hours while maintaining the temperature in the three-necked flask at 200 ° C., the degree of vacuum at 1.5 mmHg to normal pressure, and distilling off generated water and excess tetramethylene glycol. . Thereby, an oligomer was obtained.

Subsequently, tetra--was added to the obtained oligomer.
0.14 parts of n-butoxytitanium was added. Next, while stirring the oligomer, the temperature in the three-necked flask was raised to 220 ° C. under a nitrogen stream, and a transesterification reaction was performed at a reduced pressure of 2.0 mmHg for 2 hours. , And the transesterification reaction was performed at a reduced pressure of 0.1 mmHg to 0.2 mmHg for 1 hour. Thereby, an aliphatic polyester for comparison was obtained. The total reaction time is 6.0 hours.

The obtained comparative aliphatic polyester had a number average molecular weight of 48,000, a melting point of 115.0 ° C.,
Although the viscosity at ° C was 1,100 poise, no biodegradability was observed in the comparative aliphatic polyester.
Further, the volatile content in the second-stage reaction was 26.4 parts. And the volatile matter throughout was 28.0% by weight based on the charged raw materials. Table 2 shows the above measurement results and test results. In addition, a comparative aliphatic polyester having a concentration of 5 g / L
Was dissolved in chloroform such that Then, the viscosity at 30 ° C. of the comparative aliphatic polyester solution was measured. As a result, the viscosity of the solution was 0.95 poise.

However, in the above reaction, the vacuum line was often clogged during the reaction because of a large amount of volatile components throughout. Therefore, the reaction is often interrupted,
The volatile matter trapped in the trap and the volatile matter clogged in the vacuum line had to be removed.

Comparative Example 3 The reaction was carried out using a 70 L reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a suction tube. The above suction tube was connected to a general-purpose vacuum pump and a high-performance vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol). A switching cock was provided between the trap and the two vacuum pumps so that the vacuum pump used, that is, the vacuum line could be switched.

After the above reactor was replaced with nitrogen, 22.4 kg of succinic acid and 18.3 kg of 1,4-butanediol were added to the reactor.
And was charged. Next, while stirring the contents, the temperature in the reactor was increased to 192 ° C. to 220 ° C. under a nitrogen stream, and an esterification reaction was carried out at normal pressure for 3.5 hours. After that, use a general-purpose vacuum pump to stop the introduction of nitrogen.
The esterification reaction (dehydration condensation) was performed at 220 ° C. and a degree of reduced pressure of 2 mmHg to 20 mmHg for 3.5 hours.

Subsequently, nitrogen was introduced to bring the reaction system to normal pressure, and then 3.4 g of tetra-iso-propoxytitanium was added to the above reactor. Next, while stirring the contents, the temperature inside the reactor was maintained at 215 ° C. to 220 ° C. under a nitrogen stream, and a deglycol-reaction was performed at a reduced pressure of 0.2 mmHg to 15 mmHg for 4.5 hours. After that, the temperature inside the reactor
The temperature was 220 ° C. and the degree of pressure reduction was 0.2 mmHg.

Next, the vacuum line was switched in this state. Then, using a high-performance vacuum pump,
A deglycol-reaction was carried out at a temperature of 0.02 mmHg at 4.0 ° C. for 4.0 hours. Thereby, an aliphatic polyester for comparison was obtained. The total reaction time is 15.5 hours.

The obtained aliphatic polyester for comparison had a number average molecular weight of 35,000, a melting point of 110.0 ° C., and a melting point of 220 ° C.
Although the viscosity at ℃ was 820 poise, no biodegradability was observed in the comparative aliphatic polyester. The volatile matter is 10.8 kg, and
It was 26.5% by weight. Table 2 shows the above measurement results and test results. However, in the above reaction, the vacuum line was often clogged during the reaction due to the high volatile content throughout. Therefore, the reaction is often interrupted,
The volatile matter trapped in the trap and the volatile matter clogged in the vacuum line had to be removed.

[0127]

[Table 2]

Example 9 The first-stage reaction was performed using a 100-liter autoclave (reactor) equipped with a thermometer, a stirrer, and a nitrogen inlet tube. In the above autoclave, 50.2 kg of succinic anhydride as cyclic acid anhydride and zirconyl octylate as catalyst (zirconium compound)
After charging 0.296 kg, the atmosphere was replaced with nitrogen. Next, gradually heat the contents to 130 ° C while stirring,
The succinic anhydride was melted. Next, while maintaining the temperature in the autoclave at 130 ° C. and the pressure at 3.5 kgf / cm ^{2 to} 9.8 kgf / cm ² , 23.2 kg of ethylene oxide as a cyclic ether was added to the reaction system at a rate of 4.64 kg per hour for 5.0 hours.
The addition was continuous (sequential) over time. After completion of the addition, an aging reaction (ring-opening copolymerization) was further performed at 130 ° C. for 1.0 hour, and then the reaction system was cooled to room temperature. Thus, an aliphatic polyester was obtained. The number average molecular weight of the obtained aliphatic polyester is 22,700 and the melting point is 1
03.3 ° C.

Next, a second-stage reaction was carried out using a 100 L super blend (manufactured by Sumitomo Heavy Industries, Ltd.) equipped with a thermometer, a stirrer, a nitrogen inlet tube and a suction tube as a reactor. Further, the above suction tube was connected to a general-purpose vacuum pump via a trap. The trap was immersed in a cooling liquid (dry ice-methanol).

In the above reactor, 67.0 kg of the above aliphatic polyester and diphenyl phosphite, which is an antioxidant, were added.
After charging 0.670 kg and 2.680 kg of talc as a crystal nucleating agent, nitrogen substitution was performed three times. Then, under a condition of 1.5 mmHg to 3.2 mmHg and a reaction temperature of 280 ° C. in a nitrogen stream,
After reacting for 2.0 hours, the degree of decompression is 1.5 mmHg ~
The mixture was reacted and reacted under a condition of 3.2 mmHg and a reaction temperature of 240 ° C. for 2.0 hours to obtain an aliphatic polyester having a high molecular weight. The total reaction time is 10 hours.

The aliphatic polyester obtained, that is, the aliphatic polyester having a high molecular weight has a number average molecular weight of 57,900.
With a melting point of 101.0 ° C and a viscosity at 240 ° C
It was 620 poise. In addition, biodegradability was observed in the aliphatic polyester. Furthermore, the second-stage reaction volatiles are based on the charged aliphatic polyester (67.0 kg).
It was 4.2% by weight. In addition, through the above-mentioned first-stage reaction and second-stage reaction, no vacuum line was clogged or the performance of the vacuum pump was not reduced during the reaction.

[0132]

As described above, the method for producing an aliphatic polyester according to claim 1 of the present invention comprises the steps of:
Aliphatic dicarboxylic acids and aliphatic glycols having 2 to 4 carbon atoms
The raw material of the aliphatic polyester containing
280 ° C. and a reaction pressure of more than 1.0 mmHg to 5.0 mmHg, the viscosity at the reaction temperature of the reaction system becomes 100 poise to 50,000 poise at the time of 0.1 to 30 hours after the start of the reaction. This is a method of polymerizing while stirring. The method for producing an aliphatic polyester according to claim 2 of the present invention comprises:
As described above, the raw material of the aliphatic polyester has two carbon atoms.
A method comprising the steps of (1) to (6) and ethylene glycol.

In the method for producing an aliphatic polyester according to claim 3 of the present invention, as described above, the cyclic acid anhydride and the cyclic ether and / or the cyclic ester are subjected to ring-opening polymerization in the presence of a catalyst. The obtained polymer is further reacted at a reaction temperature of 180 ° C to 280 ° C and a reaction pressure of 0.3 mmHg to 5.0.
Under the conditions of mmHg, the viscosity of the reaction system at the reaction temperature at the time of 0.1 to 30 hours after the start of the reaction is 100 poise to 5
This is a method in which polycondensation is carried out with stirring so as to give a value of 0.000 poise . The aliphatic polyester according to claim 4 of the present invention.
As described above, the production method uses a high-viscosity reactor.
This is a method of performing polycondensation.

According to the above method, the polymerization can be carried out at a reduced pressure such that a general-purpose vacuum pump can be used, and the amount of volatile components generated by the side reaction or decomposition reaction can be suppressed. This has the effect that an aliphatic polyester having biodegradability and having a higher melting point than conventional ones can be produced industrially, efficiently and economically in a relatively short time.

The aliphatic polyester obtained by the above-mentioned production method has a higher melting point than the conventional one because it has a higher molecular weight than the conventional one and has almost no polyether chain. For this reason, the aliphatic polyester can be easily formed into a molded product such as a film or a sheet,
Moreover, the durability of the molded article is excellent. Aliphatic polyesters are suitable, for example, for fibers, molded articles, sheets, films and the like. Further, the film made of the aliphatic polyester is suitably used, for example, for disposable packaging materials, daily necessities and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor: Hirohiro Shiroshima 5-8, Nishiobari-cho, Suita-shi, Osaka Inside of Nippon Shokubai Co., Ltd. Hei 3-14829 (JP, A) JP-A-61-236820 (JP, A) JP-A-59-96123 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 63 / 00-63/91

Claims (4)

(57) [Claims] 1. A process for producing an aliphatic polyester, comprising: an aliphatic dicarboxylic acid having 2 to 6 carbon atoms;
A raw material of the aliphatic polyester containing an aliphatic glycol is reacted at a reaction temperature of 180 ° C. to 280 ° C. and a reaction pressure of 1.0 mmHg.
Under the condition of super to 5.0 mmHg, the viscosity of the reaction system at the reaction temperature becomes 100 po at 0.1 to 30 hours after the start of the reaction.
A method for producing an aliphatic polyester, wherein the polymerization is carried out with stirring so as to have an as- size of 50,000 poise . Wherein the aliphatic polyester raw material, the number of carbon atoms
The method for producing an aliphatic polyester according to claim 1, comprising 2 to 6 aliphatic dicarboxylic acids and ethylene glycol. 3. A process for producing an aliphatic polyester, comprising: a polymer obtained by subjecting a cyclic acid anhydride and a cyclic ether and / or a cyclic ester to ring-opening polymerization in the presence of a catalyst; At a reaction temperature of 180 ° C to 280 ° C and a reaction pressure of 0.3 mmHg to 5.0 mmHg, 0.1
A method for producing an aliphatic polyester, wherein the polycondensation is carried out with stirring so that the viscosity at the reaction temperature of the reaction system becomes 100 poise to 50,000 poise at a time point of time to 30 hours. 4. A polycondensation using a high viscosity reactor.
The aliphatic poly according to claim 1, 2 or 3,
Method for producing ester.