JPH10195186A - Continuous production of polyester polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high-quality polyester polymer continuously without encountering many difficulties resulting from an increase in the viscosity of the reaction mixture by using a tower-type continuous reactor in the production of a high-molecular-weight polyester polymer by ring opening polymerization. SOLUTION: A polymerization material comprising at least one lactone is fused in an inert gas atmosphere, continuously fed into a tower-type continuous reactor and polymerized through ring opening to continuously produce a polyester polymer. If required for the purpose of e.g. viscosity control, at most 20 pts.wt., per 100 pts.wt. polymerization component, solvent is added, and the reaction is performed. After the polymerization, the residual monomer and/or the solvent are removed from the formed polymer by means of a devolatilizer contiguous to the reactor and recovered. Alternatively, a polymerization material comprising a cyclic ester formed from two molecules of at least one hydroxycarboxylic acid and at least one polymer having hydroxyl groups and/or ester bonds is continuously fed into a tower-type continuous reactor and copolymerized to continuously produced a polyester polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a continuous method for producing a polyester polymer. More specifically, especially lactones and lactides which are bimolecular cyclic esters, that is, dilactide (lactide or 1,4-dioxa-3,6-dimethylcyclohexane-2,5-dione) or diglycolide (glycolide, Or 1,
4-dioxa-cyclohexane-2,5-dione) and a method for continuously producing a polyester polymer as a copolymer thereof. When producing the above polymer, uniform stirring becomes difficult due to the high viscosity of the reaction system, causing thermal decomposition, coloring, etc., and the quality of the produced polymer decreases, and the production capacity decreases due to high pressure loss. However, the present invention relates to an excellent continuous production method capable of solving these problems and industrially producing a polyester polymer. These polymers are useful bioabsorbable materials for medical use, pharmaceutical and agricultural chemical formulation materials such as capsules, coating materials, packaging materials such as sheets and films, and resins useful in the lamination field.

[0002]

2. Description of the Related Art Dilactide or diglycolide, which is an intermolecular cyclic ester, lactone, which is an intramolecular cyclic ester, and a polyester-based polymer which is a copolymer thereof (hereinafter, these are simply referred to as polyester-based polymers) Since it is decomposed by heat, enzymes and the like and taken into the reduction cycle to nature, many studies have been made in recent years as biodegradable polymer materials from the viewpoint of safety and prevention of local environmental pollution. With respect to the method for producing a homopolymer of dilactide or diglycolide, which is a bimolecular cyclic ester, conventionally, there are roughly two types of known production methods. That is, a method of obtaining a polymer by direct dehydration polycondensation from the corresponding hydroxycarboxylic acid, and a method of synthesizing a dehydrated cyclic ester of a hydroxy acid once known as examples of dilactide or diglycolide, and further performing ring-opening polymerization on the polymer. This is a manufacturing method for obtaining

According to the former direct polycondensation method, a molecular weight of 40
It is difficult to obtain a polymer having a molecular weight of 00 or more (CH Hal).
Ten, Lactic Acid, page 226, Ve
riag Chemie, 1971).
In the case where the molecular weight is limited to about 20,000 as disclosed in Japanese Patent Publication No. 0, and further production of a high molecular weight polymer is required, the latter ring-opening polymerization method of a cyclic esterified product has been used. As for the continuous production method of these lactides or lactones, a continuous production method of an aromatic polyester and a lactone is disclosed in JP-A-61-261124.
-283619, 61-287922, 62-2052
5, 60-27425, "Continuous production method of elastic polyester" and JP-A-2-302433, 2-30.
It is disclosed in "Production Method of Elastic Polyester" in Japanese Patent No. 2434. Each of these has a screw or paddle type stirring blade such as a kneader or an extruder inside the reactor, the reaction system is stirred by stirring by the stirrer, and the contents are sequentially transferred from the raw material charging port to the product discharging port. It is to be transferred.

Japanese Patent Laid-Open Publication No. Hei 5-93050 discloses a continuous production method of lactides. A plurality of agitation tanks are connected in series, and a reaction raw material is continuously supplied to the agitation tanks. A so-called CSTR continuous production method is disclosed in which continuous polymerization is performed with the residence time to the reaction tank as the reaction time. However, these are all reactors that use a dynamic stirrer, and they are homogeneous due to the increase in viscosity of the reaction product, which is a problem when continuously producing a polyester polymer having a high molecular weight from lactides or lactones. Regarding the difficulty of stirring and the difficulty of heat removal, no solution was disclosed or suggested. That is, even when the method for producing lactides disclosed in the above-mentioned patents or literatures is additionally tested, the viscosity of the polymer is 10,000 to several 1 as the average molecular weight of the produced polymer increases.
The viscosity rises to a very high viscosity region of 0,000 poise, making it difficult to stir with an ordinary stirrer and even to take out the reaction contents. Even if a strong stirrer is used and the stirring blade is devised to stir the reaction system, the contents of the reaction will behave like a laminar flow following the rotation of the stirring blade, and it will not be possible to mix the entire system uniformly. Have difficulty.

[0005] Further, since ring-opening polymerization of a cyclic ester is accompanied by heat generation, it is difficult to control the temperature in the reaction tank due to the difficulty of uniform stirring accompanying the increase in viscosity, and the reaction runs away or the temperature distribution in the polymer becomes poor. Quality degradation due to local heating. In recent years, to solve these problems,
Moving parts, that is, static mixers (SM) without a stirrer, have begun to be used. However, due to the structure in which the flow is divided, converted, and reversed repeatedly by a non-movable mixing element fixed in the pipe, resistance to the fluid itself is reduced. Is very large. That is, the pressure loss of the reaction system becomes extremely large, and it becomes difficult to design a reactor, a pump, and the like. Moreover,
Due to the upper limit of the discharge pressure, the production capacity is reduced. In addition, in the case of SM, there is no movable part for controlling the mixing, that is, the shearing force, so that the optimum design can be performed only in a specific operating condition, and in other cases, that is, the mixing cannot be controlled in most operating conditions. For this reason, it is inevitable to operate with a certain degree of mixing failure and heat distribution. Further, when the diameter of the SM, that is, the cross-sectional area through which the fluid passes is increased in order to reduce the high pressure loss, the poor mixing and the heat distribution become extremely large. In order to avoid this, SM may be used as a loop-type continuous reactor, but if the loop is increased, the mixing effect will increase, but the residence time distribution in the reactor will increase by that much, and the polymer due to prolonged heat reception Degradation and degradation of coloring quality are inevitable. or,
Since the flow rate in the loop increases, the equipment becomes huge and the equipment cost becomes extremely high, which is not practical.

In particular, polyester-based polymers produced from these cyclic esters have the property of being excellent in biodegradability, but on the other hand, they are easily hydrolyzed by acids, alkalis or water, and their molecular weight is easily lowered by heat. It has the property of causing damage. For example, GUPTAM, C, C
olloid Polym. Sol. (DEU) 260
(3) 308-311 and 1982 report a study of the thermal decomposition rate of a homopolymer of dilactide by thermal thermogravimetry in air, but even in a sealed reaction vessel. At a high temperature of 250 ° C. or higher, accelerated decrease in molecular weight occurs. In addition, these dilactide homopolymers and copolymers also have the property that coloring proceeds when exposed to high temperatures. That is, in the conventional method for producing these cyclic esters, uniform mixing is hindered due to the increase in viscosity accompanying the increase in the molecular weight of the polymer,
As a result, there is a problem that partial deterioration due to local heating occurs, resulting in deterioration of quality, and even if it is an experiment in a small laboratory, a more preferable manufacturing method is required for large-scale industrial production. .

[0007]

SUMMARY OF THE INVENTION Therefore, the problem to be solved by the present invention is to achieve uniform mixing due to the increase in viscosity of the reaction product which is a problem in industrially producing a high molecular weight polyester polymer. It is an object of the present invention to provide a production method for continuously producing polyester polymers of excellent quality by solving difficulties, difficulty in removing heat, and a decrease in productivity due to high pressure loss.

[0008]

In view of the above-mentioned problems, the present inventors have intensively studied a method of stirring and mixing a polyester-based polymer, a method of reducing pressure loss, and a continuous production method thereof. Type continuous reactor (A)
(Hereinafter, referred to as “continuous reactor (A)”), even if the viscosity of the polymerization liquid is high, good mixing of the reaction contents is possible, the heat of polymerization can be efficiently removed, and low pressure can be obtained. The present invention has been completed by finding that a high-molecular-weight polymer free of decomposition and coloring without loss and stable operation can be obtained with high quality, high efficiency and high productivity.

That is, the present invention relates to a specific continuous reactor (A)
In addition, the present invention provides a continuous production method of a polyester-based polymer (hereinafter, also referred to simply as a continuous production method), characterized in that one or more lactones are continuously supplied and subjected to ring-opening polymerization. In addition, in the continuous production method, a continuous production method in which 20 parts by weight or less of a solvent is added to 100 parts by weight of a polymerization component to cause a reaction, and one or more lactones are polymerized in a stirring type reaction vessel having a stirrer, followed by a continuous reaction A continuous production method in which the polymerization reaction is further promoted by using the apparatus (A). After the temperature in the reaction vessel is raised to the polymerization temperature in a stirred reaction vessel to start the polymerization, the continuous reaction apparatus (A) is further used. A continuous production method in which a polymerization reaction is carried out. The polymerization is carried out by circulating the reactants in a loop reactor (B) using a tower-type continuous reactor equipped with stirring blades (hereinafter referred to as "loop reactor (B)"). The present invention provides a continuous production method in which a polymerization raw material is melted or dissolved in a solvent in an inert gas atmosphere and supplied to a continuous reaction device (A). Further, in the continuous production method, after polymerizing using the continuous reactor (A), the remaining monomer and / or solvent in the produced polymer is removed in the devolatilizer connected to the continuous reactor (A). A continuous production method for removing and recovering and reusing the recovered monomer and / or solvent, a continuous production method in which the lactone is ε-caprolactone, and a polyester characterized in that the continuous reactor (A) is equipped with a stirring blade. The present invention provides a method for continuously producing a polymer.

[0010] The present invention further provides a continuous reactor (A) comprising:
A continuous method for producing a polyester-based polymer, comprising continuously supplying and copolymerizing at least one kind of intermolecular cyclic ester of hydroxycarboxylic acid and at least one kind of polymer having a hydroxyl group and / or an ester bond. provide. Further, in the continuous production method, a continuous production method in which 20 parts by weight or less of a solvent is added to 100 parts by weight of a polymerization component to cause a reaction, particularly, a continuous production method in which the bimolecular cyclic ester of hydroxycarboxylic acid is dilactide and / or diglycolide. Or a method in which one or more bimolecular cyclic esters of hydroxycarboxylic acid and one or more polymers having a hydroxyl group and / or an ester bond are polymerized in a stirred reaction vessel having a stirrer. A), a continuous production method in which the polymerization reaction is further promoted, the temperature in the reaction tank is raised to the polymerization temperature in a stirred reaction tank to initiate the polymerization, and then the polymerization reaction is further performed using the continuous reaction apparatus (A). A continuous production method in which the reactants are circulated and polymerized in the loop reactor (B), and the polymerization raw materials are melted under an inert gas atmosphere. In a continuous production method in which the polymer is dissolved in a solvent and supplied to the continuous reactor (A), or after polymerization is performed using the continuous reactor (A), the product is produced in a devolatilizer connected to the continuous reactor (A). A continuous production method for removing and recovering residual monomers and / or solvents in a polymer and reusing the recovered monomers and / or solvents, and a polyester system characterized in that the continuous reactor (A) has a stirring blade. The present invention provides a continuous method for producing a polymer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The continuous reactor (A) used in the present invention will be described. The continuous reactor (A) referred to in the present invention means a so-called piston flow type column reactor having extrusion flowability in addition to an ordinary complete mixing type stirring reactor. More specifically, 2 to 100 in terms of the number of complete mixing tank rows used as an indicator of piston flowability,
More preferably, a reactor designed to have 10 to 60 tanks, to achieve a complete mixing tank in each tank, and to have a reverse flow, that is, a piston flow property without back mixing between the tanks. say. For this purpose, a reactor equipped with a stirring blade is preferred.

Depending on the type of the tower type continuous reactor equipped with a stirring blade, there is one that does not have a liquid feeding mechanism in the stirring blade itself and is only for complete mixing, and also has a mixing and feeding mechanism in the stirring blade itself. There are also things. In addition, a tower provided with a jacket for heat exchange in the local area outside the tower, a tube or an element provided with heat exchange inside the tower,
Further, there is also one in which a tube for heat exchange for passing a heat medium is provided in the stirring blade itself. Further, for the purpose of controlling the number of equivalent tanks, there is a type in which the tanks are physically separated by a cutting plate or the like inside the tower, and there is also a type in which the number and structure of stirring blades and the structure of the tower are devised. Further, depending on the type of the tower-type continuous reactor with stirring blades, there are a vertical type and a horizontal type depending on its own structure.

In the production of the present polyester polymer having thermal decomposability, in the high viscosity region where the resin viscosity exceeds 10,000 poise, not only the polymerization heat but also the stirring heat generated by the stirring shear stress is intense. However, simple complete mixing type dynamic stirring generates severe local heat and causes deterioration in quality such as molecular weight reduction and coloring. Further, when SM is used, the shearing force cannot be controlled. Therefore, when the operation is deviated from the design even a little, the mixing is insufficient and the quality is deteriorated. In order to avoid this, when a loop is formed in SM to enhance the mixing effect, conversely the residence time distribution becomes large, and similarly quality deterioration occurs. Therefore, in the production of the present polyester polymer having thermal decomposability, the shearing force, that is, the mixing can be controlled by the number of revolutions of the stirring blade, and the residence time is short due to the piston flow property and the residence time distribution is narrow ( Particular preference is given to using A).

The continuous reactor (A) is usually in the form of a column. By connecting a plurality of tower-type continuous reactors with stirring blades in series, continuously supplying the raw material from the raw material charging port under an inert gas atmosphere, and by continuously moving the reactants in the reactor, The reaction can be performed continuously and without any exposure to the outside atmosphere. In this way, from charging of raw materials to reaction, devolatilization of polymer, recovery of unreacted monomer and / or solvent, and pelletization of polymer can be carried out. This is an advantage that cannot be obtained by the conventional production using a batch reactor, and is a production method which is extremely suitable for producing a decomposable polymer which is further decomposed by light depending on oxygen, water and polymer used in the present invention.

In the continuous reactor (A) used in the present invention, the temperature inside the reactor is controlled by providing a heat exchanger outside or arranging a tube or element for heat exchange inside. can do. Further, by flowing a medium through the stirring blade itself in the inside to obtain a wider heat exchange area, and additionally, by controlling the rotation speed of the stirring blade, the heat transfer coefficient is increased, and the most efficiently in the reactor. Temperature can be controlled.

The configuration of the present invention using the continuous reactor (A) can take various configurations depending on the properties of the polymer to be produced. That is, all polymerization reactions can be performed only with the continuous reactor (A). However, the continuous reactor (A) is used in the latter half of the reaction when the viscosity of the polymer is increased, and the stirring effect is particularly remarkably exhibited. Can be. At the stage where the polymer viscosity is relatively low in the initial stage of the reaction, the reaction may be carried out in a stirring reaction tank having an ordinary stirrer, and the latter step of the polymerization, where the viscosity of the polymer is increased, may be carried out in the continuous reaction device (A). it can. More specifically, the temperature in the reaction tank (also referred to as the reaction temperature) is increased to about 180 ° C. near the polymerization reaction temperature in a stirring reaction tank having a stirrer, and polymerization is started. (A), and the polymerization reaction is further advanced. It is preferable that the catalyst is separately dissolved in a small amount of the low temperature monomer, and the temperature is raised before mixing with the raw material monomer. At room temperature, when the solution is slightly polymerized and sent to the continuous reaction device (A), the polymerization of only the surroundings proceeds, the polymerization of the middle part does not proceed, and only the unpolymerized part of the middle part passes quickly. Would. As a result, the residual monomer is not reduced. Therefore, in the present invention, it is also possible to use a continuous reaction apparatus including a reaction tank having a stirrer and a continuous reaction apparatus (A) connected thereto. Further, in the initial stage of polymerization, when the polymer viscosity is low but the heat of polymerization is remarkable, it is preferable to use a continuous reaction apparatus (A) in which a tower type continuous reactor equipped with a stirring blade is connected in series.
A loop-type reactor (B) (hereinafter, referred to as a loop-type circulating polymerization line or a loop-type reactor) in which a series or a plurality of tower-type continuous reactors with stirring blades are connected in series or in parallel so that they can be circulated by piping. (May be referred to as (B))
The reaction is preferably carried out in

That is, the polymerization liquid reacted in the tower type continuous reactor equipped with a stirring blade is not returned from the reaction apparatus in one pass, one pass or one through, but is returned to the reaction apparatus in a loop system and circulated. In this case, the heat is removed and mixed by the reactant in the polymerization zone having a large heat of reaction, and then the polymerization is performed by the continuous reactor (A) connected to the loop-type circulation polymerization line. More preferable.

Since the feed rate of the raw material, in other words, the linear velocity of the reaction contents, is a factor directly related to the mixing efficiency and the heat removal efficiency, each is selected according to the degree of polymerization, viscosity and heat value of the polymer to be produced. However, since the mixing / heat removal effect can be controlled by controlling the rotation speed of the stirring blade,
Compatible with a wide range of operating conditions. Further, since the polymerization raw material used in the present invention has biodegradability or hydrolyzability, in order to suppress the decomposition of the polymerization raw material due to oxygen or moisture, while flowing an inert gas such as nitrogen gas, the polymerization raw material is used. One monomer or polymer is heated and melted at a temperature equal to or higher than the lower melting point or softening point of the monomer or polymer of the feedstock, and the other monomer and / or polymer having a higher melting point or softening point Or by dissolving the raw material monomer and / or the polymer in a solvent,
Feed to continuous reactor (A).

In the present invention, in the continuous reactor (A),
The polymerization component comprising a reactive monomer and / or a polymer can be carried out by bulk polymerization in the absence of a solvent. However, in order to adjust the viscosity of the reaction solution, the reaction is carried out in the presence of a solvent which does not adversely affect the polymerization reaction. Can also be performed. When a solvent is added to the reaction system, the viscosity of the reaction system can be reduced, so that the uniform mixing can be further improved due to the reduction of the shear, and the number of complete mixing tanks, that is, the column length can be shortened. By lowering the pressure for obtaining the flow rate necessary for mixing, the pressure resistance design of the entire reaction apparatus can be suppressed low.

The solvent which can be added to the reaction system does not react with the monomer and / or polymer of the polymerization raw material and the produced polymer, has good solubility in the monomer and / or polymer of the polymerization raw material and the produced polymer, and can be recovered and reused. Any easy solvent may be used. Specific examples include toluene,
Xylene, ethylbenzene and the like are preferably used. The amount of the solvent to be added to the reaction system is 20 parts by weight based on 100 parts by weight of the polymerization component composed of the monomer and / or polymer as the polymerization raw material.
It is preferably used in an amount of not more than 1 part by weight, and the maximum viscosity of the reaction solution throughout the reaction is preferably adjusted to 50,000 poises or less. With the amount of the solvent in this range, the reaction rate is not significantly affected, and the molecular weight of the resulting polymer does not decrease. However, the amount of solvent referred to here represents the amount of solvent in a steady state in a continuous reaction, and at the start of the continuous reaction of the present invention, the amount of solvent added to the reaction system is composed of monomers and / or polymers of polymerization raw materials. It is used in an amount of 20 parts by weight or more based on 100 parts by weight of the polymerization component. This is to avoid a sudden polymerization reaction,
The reaction system is diluted with a solvent to start the reaction, and thereafter, while observing the state, the ratio of the polymerization component composed of the monomer and / or the polymer of the polymerization raw material and the reaction temperature are gradually increased to start the polymerization reaction.

Therefore, the amount of solvent of 20 parts by weight or less with respect to 100 parts by weight of the polymerization component comprising the monomer and / or polymer as the polymerization raw material in the present invention is defined as the amount of solvent added to the reaction system in a steady continuous reaction state. means. The solvent may be added at the stage of charging the raw materials, and the mixing capacity of the continuous reactor (A) is extremely good, and the high-viscosity solution and the solvent can be easily and uniformly mixed. In the polymerization stage where the calorific value is significant, it can be added to the reaction system for the purpose of cooling. Also, when the viscosity of the reaction solution is extremely increased due to the produced polymer having a high molecular weight in the latter stage of the polymerization, it can be added to the reaction system. When a solvent is added to the reaction system during the reaction, the monomer and / or polymer of the polymerization raw material can be further dissolved in the solvent to be added and added to the reaction system, or other additives, for example, A molecular weight modifier, a plasticizer, an antioxidant, etc. may be dissolved in a solvent and added to the reaction system.

In the continuous reactor (A), the pressure in the system in the polymerization reaction of the polyester polymer when a solvent is added varies depending on the monomer and / or polymer of the polymerization raw material to be used, but is generally ² to 15 kg / cm ^2. Usually, 10 kg / cm ² or less, and the residence time (reaction time) in the polymerization reaction system is generally 1 to 8 hours. When the continuous reaction is stopped, the solvent ratio is gradually increased to withdraw the produced polymer and unreacted raw material monomer and / or polymer in the reaction system out of the continuous reaction apparatus and stop the reaction. The solvent ratio in this case also deviates from the steady state solvent ratio.
It will be 0 parts by weight or more. When the reaction is carried out without a solvent, the reaction temperature is set low at the start of the reaction, the produced polymer is recycled to the raw material charging port without taking out from the continuous reactor, and the raw material monomer and polymer are reduced in the reactor. After the circulation, the reaction temperature is gradually increased to carry out the polymerization reaction.

The conversion in the continuous reactor (A) of the present invention is preferably 85% or more, and the unreacted monomer is recovered by a devolatilizer and used again as a raw material. The recovered unreacted monomer can be continuously returned to the raw material charging tank, or can be temporarily stored in a cushion tank, mixed with the raw material monomer in the tank, and then used for the reaction. Even if the conversion is 85% or more, the remaining monomers are reactive, and if they remain in the product polymer, they affect the storage stability. Also, from the viewpoint of human safety and odor, the remaining monomers and oligomers Is not preferred, so it is desirable to remove them. Therefore, in the present invention, in order to improve the physical properties of the polymer together with the recovery and reuse of the unreacted monomer, the continuous reaction device (A) is used to polymerize the polyester-based polymer in the continuous reaction device (A). In the devolatilizer connected to the above), the residual monomer, oligomer or solvent in the produced polymer is separated and collected. The recovered solvent is separated from the recovered monomer, stored in a storage tank, and reused if necessary.

As a specific devolatilization method, the polymer produced after the completion of the polymerization reaction is first provided with sufficient fluidity to the polymer in a preheater connected to the continuous reactor (A), and the latent heat of vaporization of the devolatilized product is obtained. It is heated and melted for the purpose of giving considerable heat. The devolatilization apparatus according to the present invention may be a devolatilization apparatus using a simple flash tank. A single-stage devolatilization apparatus using a vertical devolatilization apparatus is used to remove the residual monomer and / or solvent. Devolatilization can be performed at a high temperature. However, in the present invention, devolatilization is more preferably performed by a combination of a two-stage devolatilization tank. That is, the degree of vacuum is 20 to 15 in the first-stage devolatilizer.
The devolatilization is performed at 0 mmHg, and devolatilization is performed at a higher degree of vacuum in the second-stage devolatilization apparatus, that is, at a degree of vacuum of 1 to 20 mmHg, and unreacted monomers are separated and recovered. An ordinary vacuum device can be used, and a flash type devolatilization device can be used, and a thin film type devolatilization device can also be used.

After devolatilization, the devolatilized polymer may be withdrawn from the bottom of the devolatilization device by a gear pump and pelletized. Further, the polymer can be extruded as a plurality of linear polymers having a diameter of 0.3 to 3 mm by a vent-type extruder, and continuously supplied into a devolatilizer to devolatilize. Alternatively, if necessary, the additives may be mixed by an extruder, a static mixer, or the like, and then, pelletized. The unreacted monomer can be further cooled and recovered by a condenser, and can be subjected to the reaction again with the raw material monomer.

After the continuous reaction reaches a steady state, the recovered unreacted monomer is continuously recycled to the raw material charging tank and used continuously for the reaction. The solvent separated and collected is cooled and collected by a condenser and then stored in a solvent tank and reused as necessary. When a polymer is used as a reaction raw material, in order to prevent the unreacted polymer from invading into the produced polymer, it is preferable to increase the constituent ratio of the raw material monomer to the raw material polymer, collect and reuse the unreacted monomer. . In the present invention,
By continuously using these devolatilizers, the residual monomer content in the produced polyester-based polymer can be reduced to 1% or less.

Next, the polymerization component of the polyester polymer used in the present invention will be described. The lactone used in the present invention refers to a lactone having an intramolecular cyclic ester structure, and specifically, for example, ε-caprolactone, α,
α-dimethyl-β-propiolactone, dodecanolactone, β-propiolactone, butyrolactone, valerolactone, 3-alkylvalerolactone, β, β-dialkylvalerolactone, hydroxycyclohexanecarboxylic acid lactone, isocoumarin, coumarin, Hydroxycoumarin, phthalide and the like. Of these, ε-caprolactone is preferably used.

These can be subjected to ring-opening polymerization alone to produce a polyester polymer, but they can also be copolymerized with one or more bimolecular cyclic ester of hydroxycarboxylic acid. In this case, the polymerization ratio of the bimolecular cyclic ester and the lactone can be variously changed depending on the intended polymer, but by selecting various combinations of the bimolecular cyclic ester and the lactone, favorable properties can be added to each other. Can be. For example, a copolymer of dilactide and ε-caprolactone or diglycolide is excellent in toughness, flexibility and the like, and can be formed into a film without stretching. Further, the copolymer with coumarin has an advantage of being excellent in thermal stability. Generally, for the purpose of obtaining a transparent resin, copolymerization with dilactide is preferable, and in that case, the molar ratio of polymerization of dilactide and other monomer (ratio of mol of dilactide / mol of other monomer) should be 1 or more. Is preferred.

The bimolecular cyclic ester of hydroxycarboxylic acid referred to in the present invention is an intermolecular dehydration cyclic esterification of two molecules of hydroxycarboxylic acid. For example, a part is represented by the general formula 1. Diglycolide, dilactide, which is a bimolecular cyclic ester of lactic acid, glycolic acid, ethyl glycolic acid and dimethyl glycolic acid,
Diethyl glycolide, methyl glycolide, α, α-
Dimethylglycolide, trimethylglycolide, tetramethylglycolide, and L-lactic acid or D-lactic acid, each of which is cyclic esterified between the two molecules, is a cyclic molecule of L-dilactide, D-dilactide, and D, L-lactic acid. Esterified D. L-dilactide, L-lactic acid or D
-Dilactides such as MESO-dilactide in which each molecule of lactic acid is cyclically esterified, or α-hydroxyacetic acid, α-hydroxyvaleric acid, α-hydroxyisovaleric acid, α-hydroxycaproic acid, α-hydroxyisocaproic acid , Α-hydroxy-β-methylvaleric acid, α-
Hydroxyheptanoic acid, α-hydroxyoctanoic acid, α
-Hydroxydecanoic acid, α-hydroxymyristic acid,
It refers to a bimolecular cyclic ester of hydroxy acids of α-hydroxystearic acid.

[0030]

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The bimolecular cyclic ester used in the present invention is selected according to the properties of the desired polymer, and can be used in combination of two or more. For example, even when dilactide is used as a copolymer of dilactide and diglycolide, L is simply used as dilactide.
-Not using only dilactide or D-dilactide, but using L-dilactide, D-dilactide, D,
By combining two or more dilactides selected from L-dilactide and MESO-dilactide with diglycolide, more preferable resin properties can be realized in terms of moldability, transparency and heat resistance from the viewpoint of the crystallinity of the resin.

In the present invention, a polyester polymer can be produced by copolymerizing one or more kinds of bimolecular cyclic esters and one or more kinds of polymers having a hydroxyl group and / or an ester bond. As the polymer having a hydroxyl group,
Polyvinyl alcohol, starch, cellulose, and cellulose ether. When these are used, a polymer close to graft polymerization is easily obtained, and for polyoxyalkylene ether, a polymer close to block polymerization is easily obtained.

Examples of the polymer having an ester bond include polyvinyl acetate, vinyl acetate / ethylene copolymer,
Examples of the polymer which is polycarbonate and has a hydroxyl group and an ester bond include cellulose esters and polyesters.

In the present invention, one or more of these polymers or a mixture thereof can be used without any particular limitation. However, those having a relatively large molecular weight, specifically a weight average molecular weight (Mw) of 5, 000-300,0
00, more preferably 3,000 to 20 weight average molecular weight.
Preferably, it has a melting point of 200 ° C. or less. Further, from the viewpoint of compatibility, it is preferable that 43-65% of the hydroxyl groups contained in the cellulose ester be esterified. The copolymer preferably has a vinyl acetate / ethylene molar ratio of 60/40 or more. The polyester preferably has a melting point of 200 ° C. or lower and a molecular weight of 10,000 or higher.

Although the reaction mechanism of copolymerization between these bimolecular cyclic ester and a polymer having a hydroxyl group and / or an ester bond is complicated, in the early stage of the reaction, ring-opening polymerization of the cyclic ester takes precedence, and to a certain extent cyclic It is considered that after the ester oligomer is formed, a transesterification reaction with the polymer having a hydroxyl group and / or an ester bond proceeds to form a copolymer. Furthermore,
When dilactide is used as the cyclic ester and the copolymerization molar ratio of dilactide is 1 or more, a transparent resin can be obtained.

The polymerization catalyst used in the present invention includes titanium compounds such as titanium chloride, tetrabutyl titanate, tetrapropyl titanate and tetraethyl titanate, stannous chloride, stannous bromide, stannous iodide. , Tin compounds such as tin 2-ethylhexanoate, zinc chloride, zinc acetate, zinc stearate, zinc oxide, zinc carbonate, basic zinc carbonate, zinc compounds such as diethyl zinc, aluminum compounds, magnesium compounds, barium compounds, Zirconium compounds, germanium compounds, etc., which can be used alone or in combination, and the addition amount thereof is
Usually 0.001 to 1.0%, more preferably,
It is in the range of 0.01 to 0.1%.

The ratio of the copolymer components at the time of the reaction varies depending on the required properties of the desired copolymer, but at the time of copolymerization of the bimolecular cyclic ester (X) and the lactone (Y), the ratio of X / Y The molar ratio is usually from 99/1 to
1/99, preferably 98/2 to 50/50, more preferably 95/5 to 75/25. When copolymerizing dilactide (X) and diglycolide (Y), X
The ratio of / Y is usually 99/1 to 1/99, preferably 9
8/2 to 50/50, more preferably 95/5 to 75 /
25.

In the copolymerization of the bimolecular cyclic ester (X) and the polymer (Z) having a hydroxyl group and / or an ester bond, the X / Z ratio is usually 99/1 to 1
/ 99, preferably 98/2 to 50/50, more preferably 95/5 to 75/25.

The melt viscosity of the copolymer of the intermolecular cyclic ester (X) and the lactone (Y) depends on the weight average molecular weight of the produced polymer and the constituent ratio of (X) and (Y). Average molecular weight 20,000-80,000
The melt viscosity at 180 ° C. of the resulting polymer is 5000 to 5
0000 poise, weight average molecular weight 80000-5000
00 has a melt viscosity of 20000 to 2000.
It is 00 poise, and when the constituent ratio of the lactone (Y) increases, the viscosity of the produced polymer tends to decrease.

In the continuous reactor (A) according to the present invention, dilactides are used as the bimolecular cyclic ester (X),
The residence time (reaction time) for carrying out a continuous reaction at a reaction yield of 85% in the case of reacting with a lactone (Y) varies depending on the type of the lactone (Y) used, but a weight average molecular weight of 20,000 to 80,000 is produced. When a polymer is obtained, a reaction temperature of 150 to 185 ° C. is generally 2 to 8 hours, the maximum reaction pressure in the system is ² to 10 kg / cm ² , and when a resulting polymer having a weight average molecular weight of 80,000 to 500,000 is obtained, Generally 3 to 1 at a reaction temperature of 150 to 185 ° C.
At 0 hours, the maximum reaction pressure in the system is 3 to 15 kg / cm ² .

When using diglycolides as the bimolecular cyclic ester (X) and reacting with the lactone (Y), the residence time (reaction time) for carrying out continuous reaction at a reaction yield of 85% is used. Although it depends on the type of the lactone (Y), when the resulting polymer having a weight average molecular weight of 20,000 to 80,000 is to be obtained, the reaction temperature is generally 2 to 8 hours at a reaction temperature of 155 to 230 ° C., and the maximum reaction pressure in the system is 2 to 10 kg /
cm ² and weight average molecular weight 80,000 to 50,000
To obtain a polymer of 0, a reaction temperature of 155-2
Generally, the maximum reaction pressure in the system is 3 to 10 hours at 30 ° C.
It is 15 kg cm ² .

The reaction temperature of the polymerization reaction of the present invention depends on the nature and combination of the bimolecular cyclic ester, lactone, hydroxyl group and / or ester bond-containing polymer used, but it is usually 120 to 200 ° C.
When the bimolecular cyclic ester (X) is dilactide, methyl glycolide or ethyl glycolide, the reaction temperature with the lactone (Y) is usually from 125 to 200 ° C, preferably from 145 to 195 ° C, and more preferably from 150 to 195 ° C. 185 ° C
It is.

When the bimolecular cyclic ester (X) is diglycolide, α, α-dimethylglycolide, trimethylglycolide or tetramethylglycolide, the reaction temperature with the lactone (Y) is usually from 125 to 270 ° C.
Preferably 145 to 260 ° C, more preferably 155 to
230 ° C. The reaction temperature of dilactide and diglycolide is usually 125 to 270 ° C, preferably 145 to 270 ° C.
260 ° C, more preferably 155-230 ° C.

The melt viscosity of the copolymer of dilactide and diglycolide depends on the composition ratio of both and the weight average molecular weight of the produced polymer, but the melt viscosity of the produced polymer having a weight average molecular weight of 20,000 to 80,000 at 180 ° C. is usually The melt viscosity of the produced polymer having 5,000 to 50,000 poise and the weight average molecular weight of 80,000 to 500,000 is 20,000 to 200,000 poise, and the viscosity of the produced polymer tends to decrease as the constituent ratio of diglycolide increases.

When a dilactide and a diglycolide are reacted, the residence time (reaction time) for performing a continuous reaction at a reaction yield of 85% is a weight average molecular weight of 20,000 to 8
In order to obtain 0000 of the resulting polymer, a reaction temperature of 15
The maximum reaction pressure in the system is ² to 10 kg / cm ² at 5 to 230 ° C. for generally 2 to 8 hours, and the weight average molecular weight is 8000.
In order to obtain 0 to 500,000 formed polymer, the reaction temperature is 155 to 230 ° C., generally 3 to 10 hours, and the maximum reaction pressure in the system is 3 to 15 kg / cm ² .

The reaction temperature for the copolymerization reaction of one or more lactones is usually from 125 to 290 ° C., preferably from 145 to 280 ° C.
° C, more preferably 155 to 250 ° C. The solution viscosity of the copolymer of one or more lactones depends on the type of the constituent lactones and the weight average molecular weight of the resulting polymer, and usually, the melt viscosity at 180 ° C. of the resulting polymer having a weight average molecular weight of 10,000 to 80,000 is 2,000. ~ 20
000 poise, weight average molecular weight 80,000 to 50,000
The melt viscosity of the produced polymer of 0 is 5,000 to 100,000.
Poise.

When one or more lactones are reacted, the residence time (reaction time) for carrying out a continuous reaction with a reaction yield of 85% is a weight average molecular weight of 20,000 to 8,000.
In order to obtain a product polymer having a reaction temperature of 155-2
Generally, 2 to 8 hours at 50 ° C., maximum reaction pressure of 2-1 in the system
0 kg / cm ² , weight average molecular weight 80,000-5
To obtain a polymer of 00000, a reaction temperature of 1
The maximum reaction pressure in the system is generally 3 to 15 kg / cm ² at 55 to 250 ° C. for generally 3 to 10 hours.

The reaction temperature of the copolymerization reaction between the bimolecular cyclic ester (X) and the polymer (Z) having a hydroxyl group and / or an ester bond is such that the bimolecular cyclic ester (X) is dilactide, methyl glycolide or ethyl. Glycolide, diglycolide, α, α-dimethyl glycolide,
Trimethylglycolide, tetramethylglycolide, a polymer having a hydroxyl group and / or an ester bond (Z) is a cellulose ester, a cellulose ether,
In the case of polyoxyalkylene ether, usually 125
To 200 ° C, preferably 145 to 195 ° C, more preferably 150 to 185 ° C.

The bimolecular cyclic ester (X) is dilactide, methyl glycolide, ethyl glycolide, and the polymer (Z) having a hydroxyl group and / or an ester bond is cellulose, polyvinyl alcohol, polyvinyl acetate, vinyl acetate / In the case of ethylene copolymers, aromatic polyesters, aliphatic polyesters, and polycarbonates, the reaction temperature is usually from 125 to 200 ° C, preferably from 1 to 200 ° C.
The temperature is 45 to 195 ° C, more preferably 150 to 185 ° C.

Further, the bimolecular cyclic ester (X) is diglycolide, α, α-dimethylglycolide, trimethylglycolide, tetramethylglycolide, and the polymer (Z) having a hydroxyl group and / or an ester bond is cellulose or polyvinyl. Alcohol, polyvinyl acetate,
Vinyl acetate / ethylene copolymer, aromatic polyester,
In the case of aliphatic polyester or polycarbonate, the reaction temperature is usually 125 to 270 ° C., preferably 145 to 2
60 ° C, more preferably 155 to 230 ° C.

The melt viscosity of the copolymer of the bimolecular cyclic ester (X) and the polymer (Z) having a hydroxyl group and / or an ester bond is determined by the weight average molecular weight of the resulting polymer and the constitution of (X) and (Z). Depending on the ratio, the polymer (Z) has a weight average molecular weight of 10,000 or more and 180 ° C.
The melt viscosity at 180 ° C. of the resulting polymer having a weight average molecular weight of 20,000 to 80,000 is usually 5,000 to 500
00 poise, weight average molecular weight 80,000 to 500,000
The melt viscosity of the produced polymer is 20,000 to 200,000.
It's a poise.

When a dilactide is used as the bimolecular cyclic ester (X) and is reacted with the polymer (Z) having a hydroxyl group and / or an ester bond, a residence time for performing a continuous reaction with a reaction yield of 85% is obtained. The time (reaction time)
In order to obtain a product polymer having a weight average molecular weight of 20,000 to 80,000, the reaction temperature is generally 2 to 155 ° C. to 185 ° C.
In order to obtain a polymer having a maximum reaction pressure of ² to 10 kg / cm ² in the system and a weight average molecular weight of 80,000 to 500,000 at a reaction temperature of 150 to 185 ° C., generally for 3 to 10 hours, Maximum reaction pressure 3 ~ 15kg
/ Cm ² .

When a diglycolide is used as the bimolecular cyclic ester (X) to react with the polymer (Z) having a hydroxyl group and / or an ester bond, a retention for performing a continuous reaction with a reaction yield of 85%. Time (reaction time)
When the resulting polymer having a weight average molecular weight of 20,000 to 80000 is obtained, the reaction temperature is generally 2 to 8 hours at a reaction temperature of 155 to 230 ° C., the maximum reaction pressure in the system is 2 to 10 kg / cm, and the weight average molecular weight is 80,000 to 500,000. In the case of obtaining the produced polymer, the reaction temperature is generally 155 to 230 ° C., the reaction time is generally 3 to 10 hours, and the maximum reaction pressure in the system is 3 to 15 kg.
/ Cm ² .

The maximum reaction pressure in the system described above is a reaction condition in the absence of a solvent. When a solvent is used for the reaction system and the viscosity of the reaction system is adjusted to 60,000 poise or less, the reaction The maximum reaction pressure in the system can be further reduced, and is generally 10 kg / cm ² or less, but the design conditions of the reactor should be a maximum reaction pressure of ^{2 to} 15 kg / cm ² and a residence time of 1 to 8 hours. Is preferred for safety.

In the present invention, water, lactic acid,
Low molecular weight polymers can also be obtained using up to 0.1% molecular weight regulators (chain transfer agents) such as glycolic acid and other alcohols or carboxylic acids. Further, the present invention also employs other commonly used polymer additives such as antioxidants, ultraviolet absorbers, plasticizers and the like without any particular limitation, and these can be dissolved in a solvent during the reaction. And added to the reaction system. Also,
During the continuous reaction in the present invention, in addition to the copolymerizable components described above, isocyanates, acid anhydrides, compounds having an epoxy group, and the like can be further added to improve the performance of the polymer. can do.

According to the present invention, a monomer or polymer selected from the group consisting of bimolecular cyclic ester of hydroxycarboxylic acid, lactone, polymer having hydroxyl group and / or ester bond is continuously supplied to the continuous reactor (A), In the presence or absence of a solvent, the polymerization is carried out at a polymerization reaction temperature of 125 with the reactants completely free from atmospheric oxygen and moisture.
Under a condition of ~ 270 ° C and a pressure in the reaction system of ^{2 to} 15 kg / cm ² , the reaction is continuously performed at a reaction rate of 85% or more in one pass, and then the remaining monomer and solvent are removed / recovered by devolatilization and reused. It is a method for continuously producing a polyester polymer having a melt viscosity of 500000 poise or less and a weight average molecular weight of 10000 or more.

[0057]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these. All percentages and parts are by weight unless otherwise specified.

(Example 1) In this example, as a continuous reactor (A), a column-type continuous reactor having a 1/2 inch inner diameter and a length of 50 cm with stirring blades (converted tank row number = 20) was used for each 4 reactors. Connected in series, with an inner diameter of 3/4 inch and a length of 50
cm continuous tower reactor with stirring blades (converted tank row number = 1)
5) was used in a continuous polymerization apparatus in which four units were connected in series. The catalyst was mixed with the main raw material by the catalyst supply pump by a static mixer having an inner diameter of 1/4 inch and a length of 15.5 cm immediately before the main raw material supply pump. 95 parts of L-dilactide and 5 parts of ε-caprolactone were added to a raw material supply tank, and heated under a nitrogen gas atmosphere to dissolve L-dilactide to prepare a main raw material solution. As a catalyst, tin 2-ethylhexanoate was used as a catalyst. Using 0.02 parts, main raw material supply flow rate 250 ml /
Time (specific gravity = 1), catalyst supply flow rate: 0.5 ml / hour (specific gravity = 1), and reaction temperature: 165 ° C., the mixture was continuously supplied to perform bulk polymerization. After pelletizing the obtained polymer, various properties and physical properties were measured. The measurement results are shown in Table 1.

Example 2 Example 1 was repeated except that 85 parts of L-dilactide, 15 parts of ε-caprolactone and 0.03 part of stannous chloride as a catalyst were used as the main raw material solution prepared under a nitrogen gas atmosphere. After carrying out the polymerization of the present invention in the same manner as above, the obtained resin is pelletized, various properties,
Physical properties were measured. Table 1 shows the results.

(Example 3) The same as Example 1 except that 90 parts of L-dilactide, 10 parts of coumarin, and 0.03 part of stannous chloride were used as a catalyst as a main raw material solution prepared in a nitrogen gas atmosphere. After performing the polymerization of the present invention to
The obtained resin was pelletized, and various properties and physical properties were measured. Table 1 shows the results.

(Example 4) A circulating polymerization line in which four continuous reactors with stirring blades having a diameter of 0.5 inch and a length of 60 cm and having a length of 60 cm were connected in series as a continuous reactor (A); A polymerization region consisting of a polymerization line, which is a series of four column-type continuous reactors with stirring blades of 50 inches in length and 50 cm in length (equivalent number of tanks = 15), connected in series with a circulation polymerization line equipped with a circulation gear pump. Was used. As a main raw material solution prepared under a nitrogen gas atmosphere,
Main raw material supply using 85 parts of L-dilactide, 5 parts of D-dilactide, 10 parts of aliphatic polyester resin of succinic acid and ethylene glycol (weight average molecular weight: 70,000), and 0.04 part of tetraisopropyl titanate as a catalyst The polymerization was carried out continuously under the following conditions: flow rate: 400 ml / hour, catalyst supply flow rate: 1.6 ml / hour, reaction temperature: 175 ° C., flow rate circulated through the circulation polymerization line: 2 liter / hour, reflux ratio: 5. After pelletizing the obtained polymer in the same manner as in Example 1, various properties and physical properties were measured. Table 1 shows the results.

(Example 5) From the tank bottom discharge part of the first reactor equipped with an anchor type stirring blade, the polymerization liquid in the first reactor was continuously used by using a gear pump to prepare the continuous reaction apparatus of Example 1. A continuous polymerization apparatus connected to (A) so that it can be supplied was used. As a main raw material solution prepared under a nitrogen gas atmosphere, 85 parts of L-dilactide, 5 parts of MESO-dilactide, 10 parts of polyethylene terephthalate (weight average molecular weight: 6000, melting point 85 ° C.), 2 as a catalyst
-Using 0.03 part of tin ethylhexanoate, main material supply flow rate: 500 ml / hour, catalyst supply flow rate: 1.5 ml /
Time, amount of liquid retained in the first reactor: 500 ml, reaction temperature of the first reactor: 160 ° C., flow rate of the feed solution to the continuous reactor (A): 500 ml / hour, reaction temperature of the continuous reactor (A): 175 ° C. The polymerization was carried out under the following conditions. After the obtained resin was pelletized in the same manner as in Example 1, various properties and physical properties were measured. Table 1 shows the results.

Example 6 In a nitrogen gas atmosphere, 15 parts of toluene, 79 parts of L-dilactide,
D-dilactide 2 parts, terephthalic acid, isophthalic acid,
Polyester resin composed of adipic acid, ethylene glycol and neopentyl glycol (weight average molecular weight: 3
Polymerization was carried out under the polymerization conditions of Example 5 except that 4 parts were used, and then the polymerization liquid was subjected to a devolatilization treatment with an apparatus including a heat exchanger, a devolatilization tank and the like. The temperature of the heat exchanger before the devolatilizer was 200 ° C., and the degree of vacuum in the devolatilization tank was 10 Torr.
After pelletizing the obtained resin, various properties and physical properties were measured. Table 1 shows the results.

(Example 7) The same procedure as in Example 1 was carried out except that 90 parts of L-dilactide and 10 parts of polyethylene glycol (weight average molecular weight: 200,000) were used as a main raw material solution prepared under a nitrogen gas atmosphere. The obtained polymer was pelletized and various properties and physical properties were measured. The results are shown in Table 1.
Shown in

Example 8 The same as Example 1 except that 90 parts of ε-caprolactone, 10 parts of δ-valerolactone were used as the main raw material solution prepared in a nitrogen gas atmosphere, and tin 2-ethylhexanoate was used as a catalyst. After the polymerization, the obtained polymer was pelletized and various properties and physical properties were measured. Table 1 shows the results.

Example 9 In this example, four continuous reactors (a reduced tank row number = 20) each having a 1/2 inch inner diameter and a length of 60 cm with stirring blades were used as continuous reactors (A). Connected in series, 3/4 inch inside diameter, 50 length
cm continuous tower reactor with stirring blades (converted tank row number = 1)
5) was used in a continuous polymerization apparatus in which four units were connected in series. The catalyst was mixed with the main raw material by a catalyst supply pump by a static mixer having an inner diameter of 1/4 inch and a length of 15.5 cm immediately before the main raw material supply pump. As a main raw material solution prepared under a nitrogen gas atmosphere, toluene 15 parts, L-dilactide 79 parts, D-dilactide 2 parts, terephthalic acid,
4 parts of a polyester resin (weight average molecular weight: 30,000) composed of isophthalic acid, adipic acid, ethylene glycol and neopentyl glycol was used, 0.02 part of tin 2-ethylhexanoate was used as a catalyst, and a main raw material supply flow rate: Polymerization was carried out under the conditions of 250 ml / hour, catalyst supply flow rate: 0.8 ml / hour, and reaction temperature: 185 ° C. After the polymerization, the polymerization liquid was subjected to a devolatilization treatment using a device including a heat exchanger, a devolatilization tank, and the like. The temperature of the heat exchanger in front of the devolatilizer was 20
The degree of vacuum in the devolatilization tank was 9 Torr at 5 ° C. After pelletizing the obtained resin, various properties and physical properties were measured. Table 1 shows the results.

Comparative Example 1 A polymerization reaction was carried out using a reaction vessel equipped with a helical stirring blade. The raw material solution composition and the reaction temperature were the same as those in Example 1. After polymerization was performed for 6 hours, the polymer was sampled from each part in the reaction tank, and various properties and physical properties were measured. Table 2 shows the results.

(Comparative Example 2) The stirring blade used in the reaction vessel of Comparative Example 1 was replaced with an anchor blade, the composition of the raw material solution and the reaction temperature were the same as in Example 2, and polymerization was carried out for 6 hours. The polymer was sampled from each part of the above, and various properties and physical properties were measured. Table 2 shows the results.

[0069]

[Table 1]

[0070]

[Table 2]

The residual monomer (%), number average molecular weight and weight average molecular weight shown in the table were measured by GPC, and the melting point was measured by differential thermal analysis (DSC). In addition, A, B, C and parts of Comparative Examples shown in Table 2 are
The analysis results of the polymer samples sampled from the upper part inside the reaction tank, the center part inside the reaction layer, and the lower part inside the reaction tank are shown. In the example according to the present invention, a polymer having extremely excellent homogeneity was continuously obtained, whereas in the comparative example, even in the same reaction vessel, the properties and physical property values of the obtained polymer were It can be seen that the runout is remarkable.

[0072]

Industrial Applicability The present invention solves the difficulty of uniform mixing and the difficulty of heat removal due to the increase in viscosity of a reactant in the production of a high molecular weight polyester-based polymer by ring-opening polymerization. It is possible to provide a continuous method for producing a polyester polymer of excellent quality useful in the field of packaging materials.

Claims (16)

[Claims] 1. A method for continuously producing a polyester-based polymer, comprising continuously supplying one or more lactones to a tower-type continuous reactor (A) and subjecting them to ring-opening polymerization. 2. The method for continuously producing a polyester-based polymer according to claim 1, wherein the reaction is carried out by adding 20 parts by weight or less of a solvent to 100 parts by weight of the polymerization component. 3. The polyester-based polymer according to claim 1, wherein after the polymerization is carried out in a stirring reaction tank having a stirrer, the polymerization reaction is further advanced by using the tower-type continuous reaction apparatus (A). Continuous manufacturing method. 4. The polyester polymer according to claim 1, wherein the reactant is circulated and polymerized in a loop reactor (B) using a tower-type continuous reactor. Continuous manufacturing method. 5. The polymerization raw material is melted or dissolved in a solvent in an inert gas atmosphere and supplied to the tower-type continuous reaction apparatus (A), according to any one of claims 1 to 4. Continuous production method of polyester-based polymer. 6. Polymerization using a tower-type continuous reaction apparatus (A), followed by removal of residual monomers and / or solvents in the produced polymer in a devolatilizer connected to the continuous reaction apparatus (A). The method for continuous production of a polyester polymer according to any one of claims 1 to 3, wherein the polyester polymer is recovered and the recovered monomer and / or solvent is reused. 7. The continuous process for producing a polyester polymer according to claim 1, wherein the lactone is ε-caprolactone. 8. A continuous tower reactor (A) is continuously supplied with one or more bimolecular cyclic ester of hydroxycarboxylic acid and one or more polymer having a hydroxyl group and / or an ester bond, A continuous method for producing a polyester-based polymer, characterized by polymerizing. 9. The continuous production method of a polyester-based polymer according to claim 8, wherein the reaction is carried out by adding 20 parts by weight or less of a solvent to 100 parts by weight of the polymerization component. 10. The continuous process for producing a polyester polymer according to claim 8, wherein the bimolecular cyclic ester of hydroxycarboxylic acid is dilactide and / or diglycolide. 11. The polymerization reaction is further advanced by using the continuous tower reactor (A) after the polymerization is carried out in a stirring reaction tank having a stirrer. The continuous production method of the polyester-based polymer according to 1. 12. The polyester system according to any one of claims 8 to 10, wherein the reaction product is circulated in a loop reactor (B) using a tower type continuous reactor for polymerization. Continuous production method of polymer. 13. The method according to claim 8, wherein the polymerization raw material is melted or dissolved in a solvent under an inert gas atmosphere and supplied to the continuous column reactor (A). Continuous production method of polyester-based polymer. 14. After polymerizing using a tower-type continuous reactor (A), in a devolatilizer connected to the reactor (A), a residual monomer and / or solvent in a produced polymer is recovered. , And are reused.
The continuous production method of the polyester-based polymer according to any one of the above. 15. The continuous method for producing a polyester polymer according to claim 1, wherein the tower-type continuous reaction device (A) is equipped with a stirring blade. 16. The tower type continuous reaction apparatus (A) is used after the temperature in the reaction tank is raised to the polymerization reaction temperature in a stirring reaction tank having a stirrer to start the polymerization. Or a continuous method for producing a polyester polymer according to item 11.