JP2000026583A - Production of aliphatic polyester carbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for the production of an aliphatic polyester carbonate having sufficiently high molecular weight and melting point for practical purpose, exhibiting moldability, heat-resistance, solvent resistance and mechanical strength and having faint color within a short reaction time while controlling the molecular weight in high accuracy. SOLUTION: An aliphatic polyester carbonate is produced by reacting an aliphatic polyester oligomer with a carbonate compound. In the above process, the molecular weight of the aliphatic polyester carbonate can be controlled by setting the molar ratio of the carbonate compound to the terminal hydroxy group of the aliphatic polyester oligomer to 0.4-0.6. A faintly colored aliphatic polyester carbonate having a terminal hydroxy group content of 0.01-0.50 wt.% can be produced by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable high molecular weight aliphatic polyester carbonate and a method for producing the same, and more particularly, to a biodegradable colored polyester having good moldability and excellent heat stability. The present invention relates to a low-molecular-weight aliphatic polyester carbonate having a small amount and a production method capable of accurately controlling the molecular weight with a reduced production time.

The aliphatic polyester carbonate according to the present invention has excellent fluidity and injection moldability, and is suitable for obtaining molded products such as films, sheets, filaments and fibers, and the obtained molded products have sufficient mechanical properties. It has high strength and high biodegradability in soil or activated sludge treatment, and can be widely used for packaging materials and other molded products.
For example, in the agricultural field, it can be used as a multi-film that covers the soil surface to keep the soil warm, in pots and strings for planting, or as a coating material for fertilizer, or in the fishing field for fishing lines and fish nets, and even in the medical field. It can be used as sanitary materials such as medical materials and sanitary products.

[0003]

2. Description of the Related Art In recent years, there has been a demand for the development of a polymer material which can be decomposed in a natural environment in response to environmental problems on a global scale. There is great expectation in the industry as compatible materials and new types of functional materials.

As disclosed in JP-A-7-53693 and JP-A-7-53695, the present inventors have developed an aliphatic polyester carbonate resin having a good balance of biodegradability, moldability and mechanical properties. We have been working to solve environmental problems. However, in the above production, a number average molecular weight of 10,000 obtained by reacting an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound with an aliphatic dibasic acid and / or a derivative thereof is obtained.
It took time to quantify the terminal hydroxyl groups of the following aliphatic polyester oligomers, which not only prolonged the reaction time significantly, but also caused the coloring of the resulting polymer. In addition, there is a problem that the molecular weight increases even after the vacuum is released, and it is difficult to precisely control the molecular weight.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer having a practically sufficient high molecular weight and melting point, moldability, heat resistance,
It is an object of the present invention to provide a method for producing a less colored aliphatic polyester carbonate having solvent resistance and mechanical strength and capable of controlling the molecular weight accurately with a short reaction time.

A further object of the present invention is to provide an aliphatic polyester carbonate stably at a low molecular weight at a molecular weight suitable for the purpose of processing.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, when producing aliphatic polyester carbonate, the amount of terminal hydroxyl groups of the aliphatic polyester oligomer was determined by the Fourier transform near red light. Quantitation was performed in a short time by external spectroscopic analysis, and it was found that by controlling the molar ratio of the carbonate compound to be added, the coloring of the produced polymer could be reduced and the molecular weight could be accurately controlled. In addition, the present inventors have found that the use of the partial least squares method for data analysis can improve the analysis accuracy and shorten the analysis time, and have extended the present invention.

That is, the present invention relates to a method for producing an aliphatic polyester carbonate by reacting an aliphatic polyester oligomer with a carbonate compound, wherein the molar ratio of the carbonate compound to the terminal hydroxyl group amount of the aliphatic polyester oligomer is 0. Production of a less colored aliphatic polyester carbonate having a terminal hydroxyl group content of 0.01 to 0.50 wt%, characterized in that the molecular weight of the aliphatic polyester carbonate is controlled by adjusting the molecular weight to 0.4 to 0.6. Is the way.

Further, the present invention is characterized in that the amount of terminal hydroxyl groups of the aliphatic polyester oligomer is determined by Fourier transform near-infrared spectroscopy, and the partial least squares method (PLS) is used for the data analysis. It is.

The term "aliphatic polyester oligomer" as used herein means a number average molecular weight synthesized from an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound and an aliphatic dibasic acid and / or a derivative thereof in the presence of a transesterification catalyst. Is 10,000 or less.

The production of the aliphatic polyester carbonate according to the present invention comprises a first step of obtaining an aliphatic polyester oligomer from an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound and an aliphatic dibasic acid and / or a derivative thereof; A second step of reacting the aliphatic polyester oligomer with the carbonate compound to obtain an aliphatic polyester carbonate.

The first step in the present invention is carried out in the presence of an ester catalyst at a temperature of 100 to 250 ° C., preferably 150 to 250 ° C.
At 220 ° C., an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound is reacted with an aliphatic dibasic acid and / or a derivative thereof to remove water or alcohol produced as a result of the reaction and excess dihydroxy compound. This is a step of obtaining an aliphatic polyester oligomer having a number average molecular weight of 10,000 or less. In the first step, when the molecular weight of the polyester oligomer is higher than the above, the carbonate unit content in the final polymer is significantly reduced and the biodegradability is reduced, so that it is not preferable to exceed the above molecular weight. On the other hand, when the molecular weight of the polyester oligomer is 500 or less, the melting point of the final polymer decreases, and a polymer that can withstand practical use cannot be obtained. However, when it is not particularly necessary to consider biodegradability, a polyester oligomer having a molecular weight exceeding the above-mentioned molecular weight may be used.

In the first step, water or alcohol produced as a result of the reaction of the aliphatic dihydroxy compound and / or hydroxycarboxylic acid compound with the aliphatic dibasic acid and / or a derivative thereof and excess dihydroxy compound are removed. If necessary, the reaction is carried out at a reaction temperature of 100 to 250 ° C. and finally under reduced pressure. The pressure is selected so as to achieve the above-mentioned object, and is preferably reduced to 300 mmHg or less for the purpose of promoting the reaction. In this step, the reaction between the aliphatic dibasic acid and the aliphatic dihydroxy compound
It is carried out in excess of the theoretical amount of the aliphatic dihydroxy compound with respect to the basic acid. Specifically, the aliphatic dihydroxy compound is added in an amount of 1.05 to 2.0 per mole of the aliphatic dibasic acid.
It is used in a range of 0 mole.

The molecular weight of the aliphatic polyester oligomer,
The acid value and the residual amount of the dihydroxy compound can be controlled by appropriately balancing the distillation rate of the unreacted dihydroxy compound and the reaction rate, and the conditions of the charged molar ratio, the catalyst, the temperature, the degree of reduced pressure, and the reaction time are adjusted. A method of appropriately selecting and combining and a method of blowing an inert gas at an appropriate flow rate are also realistic. Usually, the reaction temperature is 100 to 25 in the presence of a catalyst.
It can be carried out by adjusting the degree of reduced pressure stepwise at 0 ° C. For example, first, esterification is performed at normal pressure to remove water generated by the condensation reaction, and then 200 to 80 mm
A method is used in which the dehydration condensation reaction is further performed at a reduced pressure of about Hg to reduce the acid value and finally to a vacuum of 5 mmHg or less.

[0015] The reaction time can be reduced and the residual amount of the dihydroxy compound in the oligomer can be reduced by removing the excess dihydroxy compound and increasing the rate of increase in the degree of vacuum, but the reaction is completed and unreacted. It is preferable to reduce the amount of carboxylic acid, that is, the acid value. In the production of the aliphatic polyester carbonate of the present invention, the acid value of the oligomer is preferably 2.50 KOH mg / g or less, more preferably 1.50 KOH mg / g or less. An increase in the acid value is not preferred due to problems such as decomposition and coloring due to a side reaction of the carbonate compound.

The molecular weight of the aliphatic polyester oligomer can be controlled by the amount of dihydroxy compound distilled out during the deglycolization reaction. For controlling the reaction in the second step, the amount of free dihydroxy compound in the oligomer must be small. Is desirable. When the amount of the free dihydroxy compound is large, a cyclic carbonate is formed by a reaction with a carbonate compound, a cyclic ether is formed by one molecule of a dihydroxy compound by itself, or a chain ether is formed by a reaction of two molecules of a dihydroxy compound. Is generated, and an undesired side reaction such as decomposition of the carbonate compound by the generated water occurs.

Therefore, for the production of the aliphatic polyester carbonate of the present invention, the amount of the free dihydroxy compound in the polyester oligomer obtained in the first step is preferably 2.0% (wt / wt) or less. The hydroxyl value is preferably in the range of 20 to 200 KOHmg / g.

The terminal hydroxyl value of the obtained polyester oligomer is quickly measured by Fourier transform near-infrared spectroscopy, and a partial least squares method is used for data analysis. The calibration curve for data analysis is based on JIS K-1557.
It is preferable that the sample is prepared in advance using a sample having a known hydroxyl value obtained by titration, which is a method described in (1), and processed by the partial least squares method. In addition, oligomers often have a melting point of room temperature or higher, and when solidified, handling becomes complicated. Therefore, it is preferable to measure a liquid at a constant temperature equal to or higher than the melting point. For this reason, the cell holder of the spectrometer is preferably equipped with a heating block, and the calibration curve is also preferably prepared at the same temperature.

When the above-described Fourier transform near-infrared spectroscopy is used, the analysis time, which usually takes 4 to 5 hours for three samples by titration according to JIS K-1557, is reduced to about 15 minutes. Analysis by Fourier transform near-infrared spectroscopy can also be performed without sampling by inserting a cell for telemetry connected by an optical fiber inside the reactor, in which case it can be performed in real time. Can be measured. Therefore, as compared with the prior art, not only the analysis time is greatly shortened and the production cost is greatly reduced, but also the reaction can be made continuous and the cost can be further reduced. Further, it is not necessary to keep the oligomer at the reaction temperature while waiting for the titration result, and coloring is reduced.

The cell for remote measurement preferably has a structure in which a constant optical path length can be secured by immersion in the reaction solution and does not contain bubbles or the like, and a transmission type, a reflection type or a diffuse reflection type is preferable. The optical fiber used preferably has heat resistance, and examples thereof include quartz, glass, fluoride, zirconium fluoride, and chalcogenide. Quartz, sapphire, and the like are exemplified as the liquid contact lens and the like, but are not limited thereto as long as the above object can be achieved.

The second step is a step in which the polyester oligomer obtained in the first step is reacted with a carbonate compound to obtain a high molecular weight compound.
The reaction is carried out at -250 ° C, preferably 200-220 ° C, to remove the hydroxy compound and its derivative by-produced during the reaction. At a temperature of 150 ° C. or lower, a sufficient reaction rate cannot be obtained. At a temperature of 250 ° C. or higher, the polymerization reaction can proceed rapidly, but the polymer may be colored, which is not preferable. The reaction is performed by adjusting the pressure as necessary,
Depending on the type of the carbonate compound, an initial pressure reaction occurs. Finally, it is preferable to reduce the pressure to 3 mmHg or less.

By adjusting the amount of the carbonate compound added to the polyester oligomer, it is possible to control the molecular weight of the final polymer. This is based on the premise that the amount of terminal hydroxyl groups of the polyester oligomer is accurately grasped, and it is more preferable to perform high-precision analysis of the oligomer terminal by spectroscopic analysis, and also on the premise that the water content of the oligomer and the carbonate compound is controlled. When the amount of water in the raw material varies, the value of the reached molecular weight also varies. The molecular weight control can be achieved by adding a carbonate compound having a smaller amount to the terminal hydroxyl group amount, or by adding an excess of the carbonate compound, but from the viewpoint of the reaction rate and the color tone of the produced polymer, It is preferable to control the carbonate compound with a small amount. Specifically, a molar ratio of 0.4 to the quantitative result of the amount of terminal hydroxyl groups.
By adjusting the addition amount in a range of up to 0.6 times, it is possible to obtain a polymer having a target molecular weight. The range of 0.4 to 0.5 times is more preferable from the viewpoint of reaction speed and color tone. The reaction is preferably carried out with ancillary equipment capable of observing the viscosity of the resin such as stirring torque or stirring power. The stirring torque and power are observed, and the reaction is stopped when the rate of increase becomes small. Even if the stirring and the vacuum operation are released before reaching the predetermined molecular weight, the reaction does not stop sufficiently and the molecular weight increases during the pelletizing operation. The amount of terminal hydroxyl groups of the resulting polymer is preferably from 0.01 to 0.50% by weight, and if it is 0.01 or less, the coloring is large, and 0.50% by weight.
With the above, a sufficient molecular weight cannot be obtained. Similarly to polyester, solid-state polymerization can be employed as a means for increasing the viscosity, and the molecular weight can be increased by heating in the form of pellets. Further, as another method of controlling the molecular weight, in addition to the method of controlling the molar ratio of the carbonate compound to be added according to the present invention, the carbonate compound to be added is charged at a stoichiometric ratio, the vacuum is released at the target molecular weight or less, and the stirring is stopped. There is also a method of increasing the molecular weight by aging for a certain time to reach the target molecular weight.
According to this method, it is possible to produce a high molecular weight resin even when the strength of the stirring blade of the reactor is not sufficient. Although the solid-phase polymerization method and the aging method are both useful production methods, it is recommended to control the molecular weight by the molar ratio of the carbonate compound / polyester oligomer of the present invention from the reaction time and the like.

When the reaction is to be continued, a remote spectroscopic analysis is performed in a cascade manner from the raw material dissolution tank to at least one dehydration / condensation tank and at least one deglycolization tank to the final deglycolization tank or its outlet piping. A method is adopted in which a terminal cell is installed, the amount of terminal hydroxyl groups is measured in real time, and a carbonate compound having a ratio commensurate with the target molecular weight is fed. After the carbonation step, connect at least one dehydroxylation compound tank, at least one reactor capable of high vacuum and high viscosity stirring, and in some cases, a horizontal reactor, an extruder, and a vented devolatilizing extruder. The final product can be obtained.

The content of the carbonate unit in the aliphatic polyester carbonate can be controlled to a desired ratio by controlling the amount of terminal hydroxyl groups of the aliphatic polyester oligomer. If the carbonate unit content is too large,
The melting point of the aliphatic polyester carbonate obtained is low, and a polymer having practical heat resistance cannot be obtained. On the other hand, when the carbonate unit content decreases, the decomposability by microorganisms decreases. Therefore, the carbonate unit content, it is preferable to have an appropriate biodegradability, and it is preferable to be an amount that can achieve practical heat resistance, in the present invention, the carbonate unit content in the aliphatic polyester carbonate, It is preferably at least 5 mol% or more, usually 5 to 30 mol%, and particularly preferably 7 to 25 mol%.

The aliphatic dihydroxy compound used for producing the aliphatic polyester carbonate of the present invention is 1,1.
4-butanediol is used as an essential component, and for example, ethylene glycol, trimethylene glycol, propylene glycol, 1,3-butanediol, pentanediol, hexanediol, octanediol, neopentylglycol, cyclohexanediol, cyclohexane Dimethanol or the like can be used in combination as appropriate.

As the aliphatic dibasic acid used for producing the aliphatic polyester carbonate of the present invention, succinic acid is used as an essential component.
Oxalic acid, malonic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, azelaic acid and the like can be appropriately used in combination. The above aliphatic dibasic acids may be esters or acid anhydrides thereof.

Examples of the hydroxycarboxylic acid compound used in the present invention include lactic acid, glycolic acid, β-hydroxybutyric acid, hydroxypivalic acid, hydroxyvaleric acid and the like, and these can be used as derivatives such as esters and cyclic esters. .

These aliphatic dibasic acids, aliphatic dihydroxy compounds and hydroxycarboxylic acid compounds can be used alone or as a mixture, and can be combined in any desired manner. And a melting point high enough to achieve practical heat resistance. Therefore, in the present invention,
It is necessary to contain 1,4-butanediol as an aliphatic dihydroxy compound and succinic acid as an aliphatic dibasic acid in an amount of 50 mol% or more.

As the carbonate compound of the present invention, diallyl carbonate, dialkyl carbonate and the like are used. Specific examples of diallyl carbonate include, but are not limited to, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, and m-cresyl carbonate. In addition, specific examples of the dialkyl carbonate compound include, but are not limited to, dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, dibutyl carbonate, diamyl carbonate, and dioctyl carbonate. Also, in addition to the above aromatic and aliphatic carbonate compounds composed of the same type of hydroxy compound,
Asymmetric carbonate compounds composed of different kinds of hydroxy compounds and cyclic carbonate compounds such as ethylene carbonate can also be used.

In the present invention, it is easy to produce a resin having a long-chain branch. As the branching agent, (a) a polyhydric alcohol having three or more hydroxyl groups in the molecule, and (b) a carboxyl group in the molecule. A polyvalent carboxylic acid having three or more groups or (c) a polyvalent carboxylic acid compound having one or more hydroxyl groups in a molecule can be used. When a branching agent is used in combination, the addition amount is in the range of 0.05 mol% to 5 mol%. However, as the addition amount increases, the speed of increase in molecular weight increases. The molar ratio needs to be reduced as compared with the case of a straight chain.

The catalyst used in the present invention is selected from transesterification catalysts. In particular, at least one of a titanium (Ti) compound, a zirconium (Zr) compound and a hafnium (Hf) compound, and Y, La, A composite system consisting of a combination of at least one of Zn and Sn is used.
It is used in the range of 0 ^-5 to 1 part by weight. Preferred forms of the compound as the catalyst include various salts such as fatty acid salts, hydroxides, alcoholates, phenolates, and acetylacetonates. When using an aromatic-containing carbonate compound, it is desirable that the titanium-based catalyst is not used because of a coloring problem, and in order to obtain a high reaction rate using an aliphatic carbonate compound, a combination with a titanium-based compound is preferable. .

A titanium (Ti) compound, zirconium (Z
r) compounds and hafnium (Hf) compounds include:
Titanium acetylacetona, tetraisopropoxy titanium, tetrabutyl titanium, titanium tetraethoxide,
Zirconium acetylacetonate, acetylacetate zirconyl, zirconium tetraethoxide, zirconium tetraisopropoxide, zirconium tetranormal butoxide, zirconium tetratertiary butoxide, zirconyl chloride, zirconium chloride,
Examples include zirconium sulfate, zirconium oxyacetate, zirconium octoate, zirconium oxystearate, hafnium acetylacetonate, hafnium tetrabutoxide, hafnium tetraisopropoxide, and the like. Nates are particularly preferably used.

The compounds of Y, La, Zn, and Sn include yttrium acetate, yttrium naphthenate, yttrium tris (acetylacetonato), lanthanum acetate, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc stearate, zinc oxide. , Zinc phosphate, tin oxalate, tin acetylacetonate, dibutyltin oxide, tin chloride and the like are exemplified as zinc acetylacetonate, zinc acetate,
Dibutyltin oxide is particularly preferably used.

As a transesterification catalyst, a Ti compound, Z
By selecting a composite system of an r compound or an Hf compound and a compound of Y, La, Zn, and Sn, a sufficient reaction rate can be obtained even if the total amount of the catalyst is small. In particular, there is an advantage that the polymerization reaction in the second step can be performed in a shorter time. The catalyst may be added at the same time as the Ti compound, the Zr compound or the Hf compound and at least one selected from the compounds of Y, La, Zn and Sn from the beginning of the reaction, that is, from the reaction in the first step. Alternatively, the reaction of the first step, ie, the synthesis reaction of the oligomer, is performed by using a Ti compound, Z
an r compound or an Hf compound, and at least one of Y, La, Zn, and Sn compounds during the reaction in the second step;
For example, the reaction may be performed by adding a zinc compound or a tin compound.

Since the used catalyst remains in the polymer after the completion of the polymerization reaction, if it is used in excess, the thermal stability of the polymer is impaired. On the other hand, if it is too small, it takes a long time to form oligomers and complete the polymerization reaction. Necessary and not preferred. Also, for example, packaging materials used in food-related,
It is desired that the amount of the catalyst be as small as possible. In consideration of these points, the usage of the catalyst is usually 5 × 10 ⁻⁵ to 1 part by weight, preferably 1 × 10 ⁻⁴ to 2 parts by weight, based on 100 parts by weight of the raw material mixture.
× 10 ^-2 parts by weight are used.

The aliphatic polyester carbonate of the present invention contains at least 5 mol% of a carbonate unit, has a weight average molecular weight (Mw) of 100,000 or more, usually 100,000 to 300,000, and has a temperature of 190.
Melt viscosity at ℃, 60kg load is 2,000-5
It has a melting point of 70 to 180 ° C. at 0000 poise. If the weight average molecular weight (Mw) is 100,000 or less, sufficient strength cannot be obtained, and if Mw is 300,000 or more, the resin melt viscosity at the time of molding processing is undesirably high.

The aliphatic polyester carbonate of the present invention can be injection-molded and extruded, and can be used to form filaments, blow-molded products, foam-formed products, and the like. The inflation method, the T-die method and the like can form a tough film or sheet by a conventionally known molding method. The obtained unstretched product is monoaxially or biaxially stretched by a known method. It can also be a stretched film. The aliphatic polyester carbonate of the present invention includes a modifier, a filler, a lubricant, a wax, an ultraviolet absorber, an antioxidant, a stabilizer, a pigment, a colorant, various fillers, an antistatic agent, a release agent, a plasticizer. In addition to various additives such as agents, fragrances, antibacterial agents, etc., transesterification catalysts, various monomers, coupling agents, terminal treating agents, other resins, wood flour, starch and the like can be modified.

When a molded article is obtained by using the aliphatic polyester carbonate of the present invention, the molecular weight of the polymer to be used is appropriately selected depending on molding processing conditions, the type of the molded article, the molding temperature and the like. For injection molding applications, Mw in the range of 120,000 to 170,000 is sufficient except for special cases. For the production of blown films, those having a relatively high molecular weight are preferable for stabilizing the molding process and sufficient film strength.
000-230,000 are preferred.

The aliphatic polyester carbonate according to the present invention has a melt viscosity of 2,000 to 50,000.
00 poise. This melt viscosity is a melt viscosity measured by a flow tester at a temperature of 190 ° C. under a load of 60 kg. If the melt viscosity is less than 2,000 poise, the resin will flow too much to achieve stable molding. If it is more than 50,000 poise, sufficient fluidity cannot be obtained and molding becomes difficult. Generally, those having 2,000 poise to 30,000 poise are preferred.

Furthermore, setting the molding temperature is important in order to obtain stable molding processing conditions with an appropriate melt viscosity. Extruder cylinder temperature and die temperature are 120 ~
240 ° C is preferred, and 130 to 220 ° C is more preferred. If the temperature is lower than 120 ° C., the viscosity is too high, and if the temperature is higher than 240 ° C., the resin is deteriorated and a high quality molded product cannot be obtained.

For example, an unstretched film formed at a temperature of 130 to 200 ° C. by a T-die method using an aliphatic polyester carbonate having a melt viscosity of 2,000 to 30,000 poise at a temperature of 190 ° C. and a load of 60 kg is: Elasticity 0.1 gigapascal (GPa) or more, elongation 4
Has physical properties of 00% or more.

The aliphatic polyester carbonate of the present invention is a crystalline polymer having a melting point of 70 to 180 ° C. and is soluble in chloroform, methylene chloride, etc.
Excellent solubility which does not dissolve in most alcohols, ketones, ethers, esters, aliphatic and aromatic hydrocarbons such as tetrahydrofuran, methanol, acetone, ethyl acetate, diethyl ether, hexane, toluene, xylene, etc. Shows solvent properties.

Although the biodegradability is affected by the molecular weight and the content of carbonate units, the obtained film has a high molecular weight when subjected to a soil burial test at 25 ° C. and 60% RH. Nevertheless, when the content of the carbonate unit in the polymer is at least 5 mol% or more, higher degradability is exhibited as compared with the aliphatic polyester having no carbonate unit. When the carbonate unit content in the polymer is 7.0 mol% or more, 1
More than half is decomposed in 8 weeks, and completely disappears in 15 weeks for those containing 20.0 mol% or more. It is 5 times more degradable than aliphatic polyesters without carbonate units.

As described above, according to the present invention, heat resistance,
Aliphatic polyester carbonates having solvent resistance and high molecular weight sufficient for practical use can be produced.
Moreover, according to the findings of the present inventors, the biodegradability of aliphatic polyester carbonate is enhanced by the carbonate unit content, and the biodegradation rate in the environment such as in soil is appropriately selected according to the carbonate unit content. be able to.

[0045]

The aliphatic polyester carbonate of the present invention has a practically sufficient high molecular weight and melting point, is excellent in fluidity and injection moldability, has little coloring, and can be used for molding products such as films, sheets or fibers. The molded product is excellent in heat resistance, solvent resistance and mechanical strength, shows high biodegradability even in soil or activated sludge treatment, and is widely used in packaging materials and molded products. Available. Cost reduction is achieved by shortening the reaction time, and a polymer having a molecular weight suitable for a molding application can be easily produced.

[0046]

Next, the present invention will be described in more detail by way of examples.

In this example, the melting point was measured using DSC (SSC 5000 manufactured by Seiko Denshi Co., Ltd.). The molecular weight is determined by GPC using chloroform as a solvent.
(Using GPC System-11 manufactured by Showa Denko KK)
As Mw and Mn in terms of styrene.

The carbonate unit content was determined by NMR (NMR EX-270 manufactured by JEOL Ltd.) using ¹³ CNM.
Ratio of carbonate units to the total of dicarboxylic acid ester units and carbonate units by R (mol%)
Was measured. Further, the amount of terminal hydroxyl groups of the produced polymer was measured by ¹ HNMR using ¹ HNMR using NMR (manufactured by JEOL Ltd., NMR EX-270).

The melt viscosity of the aliphatic polyester carbonate was measured by a flow tester (CFT-500C manufactured by Shimadzu Corporation).
Was measured at 190 ° C. under a load of 60 kg.

Residual 1,4- in polyester oligomer
The amount of butanediol was determined using a gas chromatograph with a TCD detector (GC-14B, manufactured by Shimadzu Corporation). The acid value of the polyester oligomer, and the hydroxyl value for a calibration curve and for a comparative experiment were measured according to JIS K-1557.
The hydroxyl value of the polyester oligomer was quantified by a partial least squares method using a Fourier transform near-infrared spectrometer (HOval analyzer) manufactured by Bohmen.

Example 1 20,060 g of succinic acid was placed in a 50-liter reaction vessel equipped with a stirrer, a distillation condenser, a thermometer, and a gas inlet tube.
(169.9 mol), 1,4-butanediol 21,4
30 g (237.8 mol), 774 mg of zirconium acetylacetonate and 1.55 g of zinc acetate were charged and reacted under a nitrogen atmosphere at a temperature of 150 to 220 ° C. for 2 hours to distill water. Then, the degree of decompression is 150-80 mm
Aging was conducted for 3 hours at a reduced pressure of Hg to advance the dehydration reaction, and finally the pressure was gradually increased so that the pressure was reduced to 2 mmHg or less. The reaction was stopped when the amount reached 10,520 g. The number average molecular weight of the obtained oligomer is 1,9.
80, terminal hydroxyl value is 1 by HOval analyzer
It was measured at 40 degrees and found to be 69.9 KOH mg / g. The time required for measurement of the terminal hydroxyl value was a total of 13 minutes for 10 minutes until the vial was placed in the cell equipped with the heat block and reached a certain temperature, and 3 minutes for the measurement. Acid value is 0.51 KOHm
g / g, and the amount of remaining 1,4-butanediol is 0.3
It was 0% by weight.

Next, 30,000 g of the obtained oligomer was charged into a 50-liter reaction vessel equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube, and 3,990 g of diphenyl carbonate was added. This corresponds to a molar ratio of 0.463 with respect to the terminal amount of the oligomer. Temperature 2
At 10 to 220 ° C., the pressure was finally reduced to 1 mmHg, and the reaction was continued until the stirring torque did not increase. After reacting for 5 hours, the stirring was stopped, the vacuum was released, and pelletization was performed.
It took one hour to pelletize, but the change in molecular weight during this time was very small, about 3,000. The obtained high molecular weight compound (A-1) had a melting point of 107 ° C., a weight average molecular weight (Mw) of 132,000 as measured by GPC, and ¹³
According to CNMR measurement, 1
It had 0.3% carbonate units. The loss of diphenyl carbonate was 1.8% by weight. Further, the content of terminal hydroxyl groups measured by proton NMR was 0.35% by weight, and there was no coloration, and it was pure white.

The obtained pellets of the high molecular weight compound (A-1) were dried by a vacuum dryer at a temperature of 90 ° C. for 10 hours, and extruded with a hopper dryer (screw diameter: 20 mmφ,
L / D = 25) and the width 200 attached to the extruder
The film could be easily extruded at a temperature of 185 ° C. through a mm T-die. Further, the melt viscosity was measured after keeping the sample in a heating cylinder at a temperature of 190 ° C. for 5 minutes using a flow tester. The melt viscosity was 2,900 poise, and no increase in coloring and no decrease in molecular weight due to staying was observed.

Examples 2 to 4 Polyester oligomers were produced in the same manner as in Example 1, and the stirring torque was changed by changing the amount of diphenyl carbonate to be added to 0.473, 0.480 and 0.488 in molar ratio. The results obtained by performing the reaction until no more rise are shown in Table 1 as Examples 2, 3 and 4. It is clear from Table 1 that a polymer having a corresponding attained molecular weight can be obtained by the addition amount of the carbonate compound, and the relationship between the molar ratio and the attained molecular weight in the table is plotted on a graph or approximated by a least square method or the like. By determining the relationship between the two, the charged molar ratio for obtaining a polymer having an arbitrary molecular weight can be easily obtained.

Comparative Example 1 The same operation as in Example 1 was carried out except that the amount of diphenyl carbonate added was 0.500 in molar ratio, the reaction was carried out, and the stirring torque having a molecular weight of about 140,000 before the increase in the stirring torque was stopped. The reaction was stopped and pelletizing was started.
It took one hour to pelletize, and the molecular weight immediately after the start of pelletization was 142,000, but rose to 189,000 during one hour. The results are shown in Table 1.

Comparative Example 2 An oligomer was obtained in the same manner as in Example 1, and the reaction was carried out at a molar ratio of diphenyl carbonate of 0.510, and the reaction was continued until the stirring torque did not increase. The content of the terminal hydroxyl group of the obtained polymer measured by ¹ HNMR was 0.005, and the polymer was colored light brown. The results are shown in Table 1.

Comparative Example 3 A polyester oligomer was produced in the same manner as in Example 1, and the terminal hydroxyl value of the obtained oligomer was determined according to JIS.
It measured according to K-1557. A 2 g sample was accurately weighed and dissolved in 25 ml of a phthalic anhydride pyridine solution.
Heated at 8 degrees for 2 hours. Then, add the indicator and add 1 /
Titration was performed with a 2N aqueous sodium hydroxide solution including a blank. It took 5 hours during this time. During this time, the oligomer was kept at the reaction temperature until proceeding to the next reaction, and a slight coloring proceeded. After the titration, the same reaction as in Example 1 was performed to obtain a light brown colored polymer. The results are shown in Table 1.

[0058]

[Table 1]

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Mitsuru Nakamura 22nd Wadai, Tsukuba-shi, Ibaraki F-term in Mitsubishi Gas Chemical Company R & D Co., Ltd. (Reference) BA05 BA08 BA09 BA10 BD03A BD06A CA02 CA03 CA04 CA06 EA02 EA03 EA05 HC03 HC04A HC05A JA091 JB131 JB201 JC751 JF181 JF271 JF321 JF331 JF341 JF371 KB02 KB13 KB22 KC05 KE15

Claims (7)

[Claims] 1. A method for producing an aliphatic polyester carbonate by reacting an aliphatic polyester oligomer with a carbonate compound, wherein the molar ratio of the carbonate compound to the terminal hydroxyl group content of the aliphatic polyester oligomer is 0.4 to 0.1. 6, the molecular weight of the aliphatic polyester carbonate is controlled, and the content of the terminal hydroxyl group is 0.01 to 0.50 wt.
% Of a less colored aliphatic polyester carbonate. 2. The method according to claim 1, wherein the amount of terminal hydroxyl groups of the aliphatic polyester oligomer is determined by spectroscopic analysis.
The method for producing an aliphatic polyester carbonate according to the above item. 3. The method for producing an aliphatic polyester carbonate according to claim 2, wherein the spectroscopic analysis is Fourier transform near infrared spectroscopy. 4. The method for producing an aliphatic polyester carbonate according to claim 3, wherein a partial least squares method (PLS) is used for data analysis of Fourier transform near infrared spectroscopy. 5. The process for producing an aliphatic polyester carbonate according to claim 1, wherein the weight average molecular weight of the aliphatic polyester carbonate is from 100,000 to 300,000. 6. A polyester carbonate produced by the production method according to claim 1. 7. A molded product obtained by molding the polyester carbonate according to claim 6.