JP3144416B2 - Aliphatic polyester and / or copolymer thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aliphatic polyester and / or a copolymer thereof, and more particularly, to a biodegradable aliphatic polyester having good thermal stability and easy to be melt-molded. Or a copolymer thereof.

[0002]

2. Description of the Related Art α-Hydroxy acid polyesters represented by polylactic acid and polyglycolic acid have good biodegradability as aliphatic polyesters, and are bioabsorbable materials such as surgical sutures and microcapsules for injections. Has been used as. In recent years, due to the problem of environmental destruction caused by plastic waste, biodegradable plastics that are expected to be decomposed by enzymes and microorganisms have attracted attention, and research and development thereof have been promoted. As a method for obtaining a high-molecular-weight substance of the α-oxyacid polyester, a method of subjecting a cyclic diester of α-oxyacid (for example, referred to as lactide in the case of lactic acid) to ring-opening polymerization in the presence of a tin-based catalyst has conventionally been used. It has been known. The α-oxyacid polyester thus obtained generally undergoes thermal decomposition relatively easily at a temperature slightly higher than the melting temperature, resulting in a decrease in molecular weight. Therefore, there is a problem that the physical properties of a molded product obtained during melt molding are reduced. One of the causes is considered to be a residual metal catalyst in the polyester. For example, it is known that the tin-based catalyst causes depolymerization and transesterification of the formed polyester at a high temperature.

[0003] Therefore, in order to remove the residual metal acting as a thermal decomposition catalyst, the obtained polyester is dissolved in an organic solvent and reprecipitated, the polyester is extracted with an organic solvent and water, or the polyester is extracted. A method of adding a phosphorus-based compound as a metal catalyst deactivator to a catalyst is known from the prior art. However, in the above-mentioned method, complicated removal operations are required, and problems such as solvent recovery and solvent remaining in the polyester arise, so that these polyesters produced by a bulk polymerization method are industrially preferable. Not something. Further, in the method described later, since the method is performed by mixing with a high-viscosity molten polyester, the efficiency is low, and the fact is that a sufficient effect of preventing thermal deterioration has not yet been obtained. On the other hand, performing polymerization without using a metal catalyst requires a very long time to obtain a high-molecular-weight product, which is completely impractical. Therefore, the use of a catalyst is industrially essential. Therefore, from an industrial point of view, there is a need for an aliphatic polyester having good thermal stability while containing a catalyst.

[0004]

As described above, although aliphatic polyesters having good heat stability have been eagerly desired, such aliphatic polyesters have not yet been obtained. For this reason, an object of the present invention is to provide an aliphatic polyester having excellent heat stability and / or a copolymer thereof.

[0005]

The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have obtained a good heat by polymerizing using an aluminum compound as a ring-opening polymerization catalyst. The inventors have found that a stable aliphatic polyester can be obtained, and have completed the present invention. That is, the present invention is as follows. (1) An aliphatic polyester and / or a copolymer thereof satisfying the following formulas (II) and (III): IV _f / IV _i ≧ 0.85 (II) T _10% (° C.) ≧ 300 (III) (wherein, IV _f and IV _i are is a reduced viscosity before and after melt when melted at 1 hour inert gas atmosphere conditions at 200 ° C., respectively, T _10%, inert gas stream In thermogravimetric analysis in which heating is performed at a rate of 10 ° C./min below, the temperature at which 10% by weight of the initial weight is lost is shown.) A film formed by uniting. (3) The film according to (2) above, which is used for a packaging film, a multi-film for agriculture and horticulture, a shopping bag, a garbage bag, a tape, a fertilizer bag, or a separation membrane.

Preferably, the method is as follows. An aliphatic and / or copolymer thereof, which is represented by the following formula (I) and is characterized by containing aluminum.

[0007]

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Here, R ₁ is H or an alkyl group having 1 to 5 carbon atoms, R ₂ is an alkylene group having 1 to 20 carbon atoms, and X is H or 1 to 5 carbon atoms. An acyl group, Y is H or an alkyl group having 1 to 50 carbon atoms or an alkenyl group having 1 to 50 carbon atoms; m is a positive integer, and n is 0 or a positive integer . Here, when X is H, the aliphatic polyester and / or its copolymer have the following physical properties (II), (III) and (I).
Satisfies _{V); IV f / IV i} ≧ 0.85 (II) IV f and IV _i represents the reduced viscosity before and after melt when melted at 1 hour inert gas atmosphere conditions at 200 ° C., respectively T _10% (° C.) ≧ 300 (III) T _10% indicates the temperature at which 10% by weight of the initial weight disappears in thermogravimetric analysis in which heating is performed at a rate of 10 ° C./min under an inert gas stream. 1.00 ≧ A / (A + B) ≧ 0.95 (IV) A indicates the signal intensity of the polymer in ¹ H-NMR, and B indicates the signal intensity of the monomer in ¹ H-NMR.

The heat-stable aliphatic polyester and / or its copolymer characterized by containing the aluminum represented by the formula (I) obtained according to the present invention, particularly the compound represented by the formula (I) (II) when X is H, (II)
Aliphatic polyesters containing aluminum and / or their copolymers, which simultaneously satisfy the physical properties shown in (I) and (IV), have never been known in the art. According to the findings of the present inventors, in the properties shown in (II) and (III), when IV _f / IV _i is less than 0.85 and T _10% is less than 300 ° C., such a polyester is obtained. It can no longer be said that it has practically good thermal stability in terms of molding processability, and the molded article has a remarkable decrease in physical properties.

When X in formula (I) is a 1-acyl group having 2 to 50 carbon atoms, the aluminum-containing polyester obtained according to the present invention has good thermal stability because the hydroxyl terminal is blocked. (II),
Satisfies the physical properties shown in (III) and (IV). When X is H in formula (I), aliphatic polyesters containing aluminum are known. Ie Ber
O et al. report melt polymerization of lactide using a composite catalyst of an organoaluminum, an organozinc and water, such as trialkylaluminum, aluminum isopropoxide and aluminum acetylacetonate as a ring-opening polymerization catalyst (Makromol. Chem.). , 191,
2287). However, a considerable amount of unreacted monomer remains in the polyester obtained in this document. That is, the physical properties shown in (IV) are not satisfied, the physical properties shown in (II) and (III) are not satisfied, and the average molecular weight of the obtained polymer is low. As a result, no remarkable improvement was found in the thermal stability.

That is, in the production of an aliphatic polyester by ring-opening polymerization of a diester, a monomer remains in the polymer because a ring-opening polymerization reaction and a depolymerization reaction are in an equilibrium relationship. Here, if the physical properties shown in (IV) are not satisfied, the residual monomer causes frequent thread breakage during molding, for example, when performing melt spinning,
In addition, it causes variation in the obtained yarn strength. Further, at a high temperature at which the polymer melts, these monomers are decomposed even by a very small amount of water, thereby increasing the acid value of the polymer and causing thermal decomposition. When the physical properties shown in (IV) are not satisfied, it is usually difficult to satisfy the physical properties shown in (III).

In the present invention, the aliphatic polyester and / or its copolymer characterized by containing aluminum represented by the formula (I), especially when X is H, the above-mentioned (II) ), (III), and (IV) are simultaneously satisfied and have excellent thermal stability, and are clearly distinguished from the prior art in this respect.
Further, in the formula (I), m is preferably 100 or more and 5000 or less. It is more preferably in the range of 200 or more and 2500 or less, and most preferably in the range of 500 or more and 2000 or less. When m is less than 100, the above polyester does not exhibit the effect of improving the thermal stability by using aluminum. On the other hand, when m exceeds 5,000, the melt viscosity is high, so that melt molding is generally difficult, so that a practical problem arises.

In the present invention, the aliphatic polyester containing aluminum represented by the formula (I) and / or a copolymer thereof, particularly when X is H in the formula (I), the above-mentioned (II) , (III) and (IV) are simultaneously satisfied, and an aliphatic polyester containing aluminum and / or a copolymer thereof can be used as a catalyst for ring-opening polymerization of a specific aluminum compound as shown below, for example. It is obtained by using As a specific aluminum compound catalyst, for example, the following formula (V) (wherein,
R _a and R _c are each independently an alkyl group, a cycloalkyl group or an aryl group; R _b is a hydrogen atom or an alkyl group, a cycloalkyl group or an aryl group, and the alkyl group, the cycloalkyl group or the aryl group; May contain a substituted halogen), and / or a saturated or unsaturated aluminum carboxylate having 2 to 20 carbon atoms.

[0014]

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Here, β-coordinated to aluminum
Diketones are more specifically acetylacetone (2,
4-pentanedione), propionylacetone (2,4
-Hexanedione), 2,4-heptanedione, 2,4
-Octanedione, 2,4-decanedione, 3,5-heptanedione, 2-methyl-3,5-heptanedione,
2,2-dimethyl-3,5-heptanedione, 2,6-
Dimethyl-3,5-heptanedione, pivaloylmethane (2,2,6,6-tetramethyl-3,5-heptanedione), benzoylacetone (1-phenyl-1,3-
Butanedione), 1,3-diphenyl-1,3-propanedione, trifluoroacetylacetone (1,1,1
-Trifluoro-2,4-pentanedione), hexafluoroacetylacetone (1,1,1,5,5,5-hexafluoro-2,4-pentanedione) and the like, but are not limited thereto. Absent.

These complexes are usually easily synthesized by reacting aluminum alcoholate with the corresponding β-diketone in an organic solvent such as toluene, or by reacting aluminum sulfate with the corresponding β-diketone in water. Furthermore, most of these complexes are easily soluble in general-purpose organic solvents and have sublimability, so that they are easily purified. A complex of acetylacetone is preferred because of good catalytic activity, easy availability and easy availability of pure substance.

Specific examples of the carboxylic acid used as the carboxylate include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and linoleic acid. Examples include, but are not limited to, acids and oleic acids.

The amount of these catalysts varies slightly depending on conditions such as the type of catalyst and the type of monomer, but is used in a proportion of 0.005 to 0.1 mol% based on the diester as a monomer. Above all, 0.01 to 0.05 mol
% Is preferably used. If the amount used is less than 0.005 mol%, the polymerization rate will be remarkably reduced, and a long time will be required until the polymerization is completed. On the other hand, when the content exceeds 0.1 mol%, the effect of improving the thermal stability by using an aluminum catalyst is not exhibited, and the coloring of the polymer is remarkable. It is appropriately selected within this predetermined range according to the application.

In the present invention, in order to block the hydroxyl terminal of the polyester formed by the 1-acyl group, polymerization is carried out by adding an aliphatic carboxylic acid having 2 to 50 carbon atoms.
Specific examples of the aliphatic carboxylic acid used include acetic acid,
Propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, linoleic acid, oleic acid, succinic acid, adipic acid, suberic acid, Examples include, but are not limited to, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, fumaric acid, and the like. Moreover, even if these acid anhydrides are used, it does not matter. Preferred are stearic acid, palmitic acid, myristic acid, linoleic acid, oleic acid, fumaric acid, succinic acid, and adipic acid, and their evaluation as a food additive has been established. Still more preferably, stearic acid, which is a raw material of calcium stearyl lactate used as an auxiliary for baking, is exemplified. The amount of these aliphatic carboxylic acids varies depending on the purpose, but is usually used at a ratio of 0.001 to 1 mol% with respect to the diester as a monomer.

The reaction is carried out in an inert atmosphere such as nitrogen or argon,
Alternatively, the reaction may be performed under reduced pressure, or using a solvent,
It is not necessary to use it. In view of problems such as recovery of the solvent, industrially, bulk polymerization using no solvent is preferred. At that time,
A catalyst and a carboxylic acid may be added. Polymerization temperature,
The polymerization time is maintained until the polymer reaches the target molecular weight and depends on factors such as the type of monomer, the type of catalyst to be added, the amount of catalyst, the amount of alcohol and the amount of carboxylic acid. The polymerization for obtaining the aliphatic polyester and / or a copolymer thereof of the present invention is usually performed at a relatively low temperature such as 100 ° C to 150 ° C. When the residual monomer is removed by a solid-phase heat treatment after the completion of the polymerization, the reaction is carried out at a relatively high temperature such as 150 ° C. to 250 ° C., and the polymerization rate is increased to allow the polymerization to reach equilibrium in a short time and to be terminated. In each case, the polymerization temperature is set to be equal to or higher than the melting point of the monomer.

In the present invention, as the molecular weight regulator,
Further, a monohydric or higher polyhydric alcohol having 1 to 50 carbon atoms may be used to increase the apparent polymerization rate and to block the acid terminal of the polyester formed by the alkyl group or the alkenyl group. Specific examples of the aliphatic alcohol used include methanol, ethanol, propanol, isopropanol, butanol, amyl alcohol, octyl alcohol, decanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, methyl lactate, ethyl lactate,
Monoalcohols such as propyl lactate; dialcohols such as ethylene glycol, propanediol, butanediol, hexamethylene glycol and dodecamethylene glycol; and polyhydric alcohols such as glycerin, sorbitol, ribitol, and erythritol. It is not something to be done. Preferred are linear higher aliphatic alcohols such as decanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, and stearyl alcohol, which are easily obtained from natural fats and oils and are harmless. More preferred is lauryl alcohol. These alcohols are thought to coordinate with the catalyst to produce active species and act as initiators. The amount of these alcohols varies depending on the purpose, but is usually used at a ratio of 0.01 to 0.5 mol% based on the diester as a monomer.

As the diester used in the present invention, specifically, glycolide, lactide, α-hydroxybutyric acid, α-hydroxyvaleric acid, α-hydroxyisovaleric acid, α-hydroxycaproic acid, α-hydroxyisocaproic acid , Α-hydroxy-β-methylvaleric acid,
and intermolecular diesters such as α-hydroxyheptanoic acid. Of these, glycolide and lactide are readily available, and the physical properties of these polymers are desirable and are preferred diesters.
Those having an asymmetric carbon include L-form, D-form, racemic-form,
Any of meso bodies may be used. Diesters are different α-
Even if it is formed by oxyacid molecules, it does not matter. Specific examples thereof include 3-methyl-2,5-dione-1,4-dioxane, which is a cyclic dimer between glycolic acid and lactic acid and is commonly known as monomethyl glycolide.

In the present invention, the second component and the like may be copolymerized in order to variously change the mechanical characteristics, the decomposition characteristics, and the like. Among them, a component having biodegradability is preferable. Specifically, it is an oxyacid component comprising an alkylene group having 1 to 20 carbon atoms, and the polymerization may be carried out in the presence of the corresponding lactone. Specifically, β-propiolactone, β
-Butyrolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, δ-caprolactone, ε
-Caprolactone, pivalolactone, enantholactone, dodecanolactone and the like, but are not limited thereto.

The α-oxyacid polyester thus obtained has improved thermal stability and facilitates melt molding, so that various biodegradable molded products can be produced. If necessary, additives such as a pigment, an antioxidant, a deterioration inhibitor, a plasticizer, a matting agent, an antistatic agent, a fluorescent brightener, and an ultraviolet absorber may be added. Further, if necessary, it may be mixed with other polymers and / or inorganic substances. Mixable polymers include polyolefins, polyesters, polyamides, polyurethanes, polyethers, polyalkylene glycols, modified and / or unmodified starch or natural polymers such as cellulose. Examples of inorganic substances that can be mixed include talc, molecular sieves, calcium carbonate, calcium chloride, and the like.

The α-oxy acid polyester of the present invention can be formed into a fiber, a film or various molded products from a molten or solution state, and is useful as a biodegradable material. Specific uses for fibers and non-woven fabrics include fishing line, fish net, non-woven fabric for planting roots, non-woven fabric for nursery beds,
For films such as weed control sheets, packaging films, agricultural and horticultural multi-films, shopping bags, garbage bags, tapes, fertilizer bags, separation membranes, etc.For molded products, beverages and cosmetics bottles, disposable cups, trays, knives , Fork and spoon, tableware for agriculture, flowerpots for agriculture, nursery beds, pipes that do not need to be dug out, temporary building materials, and the like. Further, as medical applications, applications to the DDS field such as sutures, artificial bones, artificial skins, microcapsules, and the like can be considered, but the present invention is not limited thereto.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The characteristic values in the examples were measured by the following methods.

(1) Reduced viscosity (ηsp / C) 0.125 g of polymer was mixed with chloroform or a mixed solvent of phenol-trichlorophenol (10/7),
Dissolve in 25 ml, 25 ± 0.1 ° C or 3
The reduced viscosity was calculated by measuring at 0 ± 0.1 ° C.

(2) 10% Weight Loss Temperature The temperature was measured at a heating rate of 10 ° C./min in an argon atmosphere using TGA-50 manufactured by Shimadzu Corporation. (Sample size 10
mg)

(3) Amount of Residual Monomer (wt%) Calculated from the signal intensity of methylene protons of the polymer and the monomer using Gemini-200 manufactured by Varian.

(4) Aluminum content (w / w ppm) After the polymer was ashed and dissolved in an acid, it was quantified by a high frequency plasma emission method.

Example 1 10.0 g (69.4 mmol) of L-lactide and 9 mg of aluminum acetylacetonate (28 μmol)
1, a monomer solution (0.04 mol%) in toluene was charged into a polymerization ampule, dried under reduced pressure for 1 hour, and purged with nitrogen, and then sealed under reduced pressure and heated to 130 ° C. to carry out ring-opening polymerization. When the solution viscosity in chloroform of the polymer obtained by completing the reaction in 48 hours was measured, ηsp / C =
6.31. This was dissolved in deuterated chloroform and the amount of unreacted monomer was measured by ¹ H-NMR to be 0.8%. T10 _% by TGA was 338 ° C. This product is crushed into pellets,
After drying at 0 ° C. for 48 hours, it was melted at 200 ° C. under a nitrogen atmosphere. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, to obtain a IV _f / IV _i = 0.92. No lactide adhered to the vessel wall. The aluminum concentration in the polymer was 130 ppm.

Comparative Example 1 10.0 g of L-lactide (6.94 × 10^-2mol)
Tin octylate (2-E) widely used in this field
Example 1 with 3 mg (7 μmol) of tin tylhexanoate
When the polymerization was carried out in the same manner as in
The resulting polymer showed ηsp / C = 8.45. This one
Is dissolved in deuterated chloroform to reduce the amount of unreacted monomer.¹H
It was 1.3% as measured by -NMR. TGA
By T _Ten%Was 245 ° C. And this one
And dried under reduced pressure at 60 ° C. for 48 hours.
That is, it was melted at 200 ° C. under a nitrogen atmosphere. 1 hour stirring
When the solution viscosity of the polymer obtained after was measured,
IV_f/ IV_i= 0.58. White lacchi on the wall
Has adhered.

Example 2 10.0 g (69.4 mmol) of L-lactide and 9 mg of aluminum acetylacetonate (28 μmol)
The toluene solution of 1) was charged into a polymerization tube having a stirrer and a nitrogen inlet tube, dried under reduced pressure for 1 hour, and purged with nitrogen, and then heated to 190 ° C. to effect ring-opening polymerization. The polymer obtained after the reaction was completed in 4 hours showed ηsp / C = 2.01. It was dissolved in deuterated chloroform amount of unreacted monomer by ¹ H
It was 5.2% as measured by -NMR. This was crushed into pellets, dried at 120 ° C. for 48 hours under reduced pressure, and subjected to solid phase treatment. The resulting polymer has ηsp / C =
1.95 was indicated. This was dissolved in deuterated chloroform, and the amount of unreacted monomer was measured by ¹ H-NMR to be 0.5%. That is, it was clear from this example that at 120 ° C., the monomer could be removed with almost no thermal decomposition. TGA by TGA _10%
Was 335 ° C. This was melted at 200 ° C. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, to obtain a IV _f / IV _i = 0.94. No lactide adhered to the vessel wall. The aluminum concentration in the polymer was 152 ppm.

Comparative Example 2 10.0 g of L-lactide (6.94 × 10^-2mol)
3mg tin octylate widely used in this field
(7 μmol) and polymerized for 1 hour in the same manner as in Example 2 to obtain
The resulting polymer showed ηsp / C = 2.77. Heavy chloro
Dissolve in form to reduce unreacted monomer¹By H-NMR
It was 7.8% when measured. The same as in Example 2
After phase treatment, the resulting polymer was ηsp / C = 1.
85. Dissolve this in chloroform-d
To reduce the amount of unreacted monomer¹When measured by H-NMR
1.0%. That is, in the comparative example,
Even at ℃, thermal decomposition occurs when treated for a long time.
It became clear that T by TGA_Ten%Is 24
3 ° C. This was melted at 200 ° C. 1 o'clock
The solution viscosity of the polymer obtained after stirring during was measured
By the way, IV_f/ IV _i= 0.65. White on the wall
Of lactide adhered.

Example 3 10.0 g (69.4 mmol) of L-lactide and
Luminium acetylacetonate 9mg (28μmo
1), lauryl alcohol 18.7 mg (100 μmo
l) Toluene solution is charged into a polymerization ampoule and reduced for 1 hour.
After drying under pressure and purging with nitrogen, it is sealed under reduced pressure and
Heated to ℃ to effect ring-opening polymerization. 10 hours to finish the reaction
Measure the viscosity of the obtained polymer in chloroform
As a result, ηsp / C = 1.90 was shown. This one
Dissolve in heavy chloroform to remove unreacted monomer¹H-N
It was 0.9% as measured by MR. By TGA
T _Ten%Was 340 ° C. Also pellet this
And dried under reduced pressure at 60 ° C. for 48 hours.
Melted at 00 ° C. The poly obtained after stirring for 1 hour
When the solution viscosity of the mer was measured, IV_f/ IV_i=
0.95 was obtained. No adhesion of lactide to vessel wall
I couldn't. Aluminum concentration in the polymer is 120
ppm.

Comparative Example 3 10.0 g (69.4 mmol) of L-lactide was used in 3 mg (7 μmol) of tin octylate (tin 2-ethylhexanoate) and 18.7 mg (100 μmol) of lauryl alcohol widely used in the art. When polymerization was carried out for 4 hours in the same manner as in Example 3, the reaction was completed in 10 hours, and the resulting polymer showed ηsp / C = 1.87. This is dissolved in deuterated chloroform to reduce the amount of unreacted monomer to ¹ H.
It was 1% as measured by -NMR. T _10% by TGA was 260 ° C. This is crushed into pellets and dried under reduced pressure at 60 ° C. for 48 hours.
Melted at 00 ° C. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, IV _f / IV _i =
0.68 was obtained. White lactide adhered to the vessel wall.

Example 4 10.0 g (86.2 mmol) of glycolide and 9 mg (28 μmol) of aluminum acetylacetonate
Was placed in a polymerization ampoule, dried under reduced pressure for 1 hour, and purged with nitrogen, and then sealed under reduced pressure and heated to 150 ° C. to effect ring-opening polymerization. The solution viscosity in a phenol-trichlorophenol solvent of the polymer obtained by completing the reaction in 18 hours was ηsp / C = 1.12. This was dissolved in hexafluoroisopropanol, and the amount of unreacted monomer was measured by ¹ H-NMR to be 1.2%. T _10% by TGA is 335
° C. This was crushed into pellets, dried at 60 ° C. for 48 hours under reduced pressure, and then melted at 200 ° C. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, to obtain a IV _f / IV _i = 0.95. No glycolide adhered to the vessel wall.

Example 5 10.0 g (69.4 mmol) of D, L-lactide and 9 mg of aluminum acetylacetonate (28 μm
ol), 42.8 mg of myristyl alcohol (200 μl)
mol) of toluene solution was charged into a polymerization ampoule, dried under reduced pressure for 1 hour, and purged with nitrogen.
Heated to 50 ° C. to effect ring-opening polymerization. When the solution viscosity in chloroform of the polymer obtained by completing the reaction in 10 hours was measured, it was found that ηsp / C = 1.26. This is dissolved in deuterated chloroform to reduce the amount of unreacted monomer to ¹ H.
-It was 0.9% as measured by NMR. TGA
T _10% was 332 ° C. This was crushed into pellets, dried at 40 ° C. for 48 hours under reduced pressure, and then melted at 200 ° C. The solution viscosity of the polymer obtained after stirring for 1 hour was measured and found to be IV _f / IV _i
= 0.91. No lactide adhered to the vessel wall. Aluminum concentration in the polymer is 12
It was 8 ppm.

Example 6 10.0 g (69.4 mmol) of D, L-lactide and 3 mg of aluminum acetylacetonate (7 μmo
l), myristyl alcohol 42.8 mg (200 μm
ol) was placed in a polymerization ampoule, dried under reduced pressure for 1 hour, and purged with nitrogen.
Heated to 0 ° C. to effect ring-opening polymerization. The solution viscosity in chloroform of the polymer obtained by completing the reaction in 36 hours was ηsp / C = 1.18. This was dissolved in deuterated chloroform to reduce the amount of unreacted monomer to ¹ H-
It was 1.2% as measured by NMR. T10 _% by TGA was 337 ° C. This was crushed into pellets, dried at 40 ° C. for 48 hours under reduced pressure, and then melted at 200 ° C. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, IV _f / IV _i =
0.94 was obtained. No lactide adhered to the vessel wall.

Example 7 10.0 g (69.4 mmol) of L-lactide and 8 mg of aluminum dipivaloyl methanate (14 μmol)
l), stearyl alcohol 27.1 mg (100 μm
ol) was placed in a polymerization ampoule, dried under reduced pressure for 1 hour, and purged with nitrogen.
Heated to 0 ° C. to effect ring-opening polymerization. The solution viscosity in chloroform of the polymer obtained by completing the reaction in 2 hours was ηsp / C = 2.05. This was dissolved in deuterated chloroform to reduce the amount of unreacted monomer to ¹ H-N
It was 0.9% as measured by MR. T10 _% by TGA was 338 ° C. This is crushed into pellets and dried under reduced pressure at 40 ° C. for 48 hours.
Melted at 00 ° C. The solution viscosity of the resulting polymer after stirring for 1 hour was measured, IV _f / IV _i =
0.93 was obtained. No lactide adhered to the vessel wall. Aluminum concentration in polymer is 68p
pm.

[0041]

As is clear from the above examples, the aliphatic polyester containing aluminum and / or its copolymer according to the present invention has good thermal stability and can be easily melt-molded. It is possible to produce various biodegradable molded articles without causing thermal degradation. Since the obtained molded article can be expected for a wide range of uses, it will greatly contribute to solving the industrial and environmental problems.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Ito 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyo Spinning Co., Ltd. (72) Inventor Minako Arichi 2-1-1 Katata, Otsu-shi, Shiga Prefecture (In Japanese) Toyo Boseki Co., Ltd. (72) Inventor Kiyoshi Hotta 2-1-1 Katata, Otsu-shi, Shiga Toyo Boseki Co., Ltd. (56) References JP-A-2-84431 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (3)

(57) [Claims] 1. An aliphatic polyester and / or a copolymer thereof satisfying the following formulas (II) and (III): IV _f / IV _i ≧ 0.85 (II) T _10% (° C.) ) ≧ 300 (III) (wherein, IV _f and IV _i represents the reduced viscosity before and after melt when melted at 1 hour inert gas atmosphere conditions at 200 ° C., respectively, T _10%, the inert In thermogravimetric analysis in which heating is performed at a rate of 10 ° C./min in a gas stream, the temperature at which 10% by weight of the initial weight disappears is shown. 2. A film obtained by molding the aliphatic polyester according to claim 1 and / or a copolymer thereof. 3. The film according to claim 2, which is used for a packaging film, an agricultural / horticultural multi-film, a shopping bag, a garbage bag, a tape, a fertilizer bag, or a separation membrane.