JP3073985B1 - Method for producing aliphatic polyester-based polymer - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To produce a high molecular weight aliphatic polyester polymer having a practically sufficient melting temperature, excellent color tone and excellent mechanical strength at an industrially advantageous polymerization rate at a practically high polymerization rate. A method of manufacturing is provided. SOLUTION: (i) A mixture of an aliphatic dicarboxylic acid or a diester thereof and an aliphatic diol or (ii) a precondensate of the mixture is used as a reaction material, and the reaction material is subjected to polymerization in the presence of a transesterification catalyst. In the condensation reaction method, an organic compound represented by the following general formula (I) O = P (OH) ₂ R (I) (wherein R represents an aliphatic group or an aromatic group) as a cocatalyst for the catalyst. Production of an aliphatic polyester-based polymer characterized by using at least one protonic acid selected from an aliphatic and / or aromatic compound having a phosphonic acid, a sulfonic acid group or a sulfate group and sulfuric acid. Method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an aliphatic polyester-based polymer and a polymer obtained by the method.

[0002]

2. Description of the Related Art Synthetic polymers such as polyolefins and aromatic polyesters are used in large quantities as indispensable materials for daily life. However, since these synthetic polymers are not decomposed in the natural environment, they have a high disposal cost. Environmental problems have become apparent with the increase in molecules. For this reason, biodegradable plastics are being developed, and aliphatic polyesters are receiving attention as biodegradable polymers. But,
Conventional aliphatic polyesters have many problems to be solved in terms of cost, strength and the like. For example, polyhydroxybutyrate is a polyester having a high melting temperature and good performance, but since the difference between the melting temperature and the decomposition temperature is small, it is liable to be thermally decomposed at the time of molding and cause problems such as performance deterioration and odor generation. In addition, since the polymer is produced using a microorganism, productivity is low and cost is high. Polycaprolactone is one of the few aliphatic polyesters that is currently industrially produced, but its use is limited because its melting temperature is only about 60 ° C.
Furthermore, polymers of hydroxycarboxylic acids have been attracting attention as polymers with good biodegradability. In particular, polymers of lactic acid are biocompatible polymers that can be used in bioabsorbable materials. Is complicated.

[0003] In order to solve the above-mentioned problems relating to the production and performance of aliphatic polyesters, polyesters obtained by polycondensation of aliphatic dicarboxylic acids or anhydrides thereof with glycols have attracted attention. The method of producing this polyester has been known for a long time, and succinic acid, adipic acid, suberic acid, sebacic acid, dodecadicarboxylic acid, etc. are used as the acid, and ethylene glycol, 1,4-butanediol, 6-cyclohexanediol, 1,
A method using 4-cyclohexanedimethanol or the like has been reported. And it is reported that the melting temperature of the polymer using succinic acid as a raw material is 70 ° C. or higher. However, all of these polymers have a number average molecular weight of about several thousands, and thus do not have a mechanical strength that can be made into a film or a fiber.

Recently, aliphatic polyesters have been spotlighted as biodegradable plastics. Therefore, a number of polyester production methods having a large number average molecular weight and a high mechanical strength have been proposed as described below. However, in any of these proposals, the production process is increased and the polymer performance is sometimes lowered. According to JP-A-4-189822 and JP-A-4-189823, an aliphatic polyester having a number average molecular weight of about 15,000 is produced from an aliphatic dicarboxylic acid or a derivative thereof and a glycol, and this is produced by diisocyanate. A method for increasing the molecular weight by crosslinking is shown. However, this method has problems such as formation of a microgel and deterioration of the polymer quality. According to JP-A-5-287041 and JP-A-5-287042, aliphatic dicarboxylic acid, glycol and polyvalent isocyanate are copolymerized, whereby the number average molecular weight is high and the molecular weight distribution is high. Obtaining a wide polymer. This polymer has a high molecular weight,
In addition to its high mechanical strength, it has a high melt viscosity due to its wide molecular weight distribution, and is suitable for producing molded articles such as films. For the same purpose, JP-A-5-287068 discloses a four-component copolymer obtained by adding 3,3,4,4-benzophenonetetracarboxylic anhydride in addition to the three components described above.
JP-A-5-295071 proposes a four-component copolymer to which a polyhydric alcohol such as pentaerythritol is added in addition to the above three. However, these copolymers have problems such as formation of a gel. In addition, JP-A-6
No. 192374, a low molecular weight aliphatic polyester is synthesized from an aliphatic dicarboxylic acid and a glycol and a polyhydric alcohol or a polycarboxylic acid, and reacted with an aliphatic polyester having an isocyanate group at the end thereof. Methods for obtaining high molecular weight polymers free of microgels have been proposed. However, this method has a disadvantage that the number of manufacturing steps is further increased.

[0005] Therefore, according to Japanese Patent Laid-open flat 8-143656, by copolymerizing more carbonate compounds in aliphatic dicarboxylic acid diester with an aliphatic glycol, by an aliphatic polyester carbonate, to improve the biodegradability It has been proposed that biodegradability can be controlled by changing the copolymerization ratio. However, in the case of this polyester carbonate, the mechanical strength is reduced by copolymerizing the carbonate compound.

On the other hand, in the process for producing an aliphatic polyester polymer, a general ester exchange reaction catalyst such as titanium tetraisopropoxide is used. However, in the case of this catalyst, the polyesterification reaction rate is still insufficient, and in addition to the problem of coloring of the obtained polymer, the mechanical properties of the obtained polymer, especially for applications such as films and yarns, especially There are problems that should be improved in practice, such as insufficient breaking elongation. Regarding the problem of coloring, US Pat. No. 5,504,148 (1996) proposes a method of increasing the molecular weight by adding phosphoric acid or the like as a coloring inhibitor to a Ti catalyst. However, the reaction rate is still insufficient, and problems such as the formation of by-products such as tetrahydrofuran from the raw material diol due to the presence of a phosphorus compound such as phosphoric acid (Chemical Encyclopedia, Vol. 7, 850p (Showa 37)). However, the cost is insufficient and there is a problem to be improved.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a high-molecular weight aliphatic polyester polymer having a practically sufficient melting temperature, excellent color tone and excellent mechanical strength. It is an object of the present invention to provide a process which is industrially advantageous at a high speed and a polymer obtained therefrom.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, (i) a mixture of an aliphatic dicarboxylic acid or a diester thereof and an aliphatic diol or (ii) a precondensate of the mixture is used as a reaction raw material, and the reaction raw material is used as a transesterification catalyst. In the method of performing a polycondensation reaction in the presence, as a cocatalyst for the catalyst, the following general formula (I) O = P (OH) ₂ R (I) (wherein R represents an aliphatic group or an aromatic group) Aliphatic polyesters characterized by using at least one protonic acid selected from the group consisting of aliphatic and / or aromatic compounds having an organic phosphonic acid, a sulfonic acid group or a sulfate group, and sulfuric acid. A method for producing a polymer is provided. Further, according to the present invention, in the method of using (i) an oxycarboxylic acid-based compound or (ii) a precondensate thereof as a reaction raw material and subjecting the reaction raw material to a polycondensation reaction in the presence of a transesterification catalyst, As a cocatalyst for the catalyst, an organic phosphonic acid or sulfonic acid group represented by the following general formula (I) O = P (OH) ₂ R (I) (wherein R represents an aliphatic group or an aromatic group) Alternatively, there is provided a method for producing an aliphatic polyester-based polymer, characterized by using at least one protonic acid selected from an aliphatic and / or aromatic compound having a sulfate group and sulfuric acid.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION To produce a polymer of the present invention,
An aliphatic dicarboxylic acid or a diester thereof is used as a main reaction material. This is represented by the following general formula (1)
It is represented by

Embedded image In the above formula, R ¹ has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms.
Represents a divalent aliphatic group. The divalent aliphatic group can be linear or cyclic, and can be saturated or unsaturated. Further, the divalent aliphatic group may contain a hetero atom such as oxygen in addition to carbon in the main chain. Preferred divalent aliphatic groups used in the present invention,
Examples thereof include an alkylene group or alkenylene group which may have an ether bond having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, an alkyleneoxy group or an oxyalkylene group. When showing a specific example of the divalent aliphatic group, -CH ₂ -, - C ₂
H ₄ —, —CH ₂ O—, —CH ₂ OCH ₂ —, —C ₃ H ₆ —,
_{-C 4 H 2 -, - C} 6 H 12 -, - C 3 H 16 -, - C 12 H
_{24 -, - C 12 H 22} - , and the like. t represents zero or a number of 1. When t is zero, the dicarboxylic acid component represented by the general formula (1) is oxalic acid (HOOC-COO).
H), and when t is 1, the dicarboxylic acid component is R
A dicarboxylic acid or ester thereof represented by ¹¹ OOC-R ¹ -COOR ¹¹ is shown. In the general formula (1), R ¹¹ represents hydrogen, a lower alkyl group or an aryl group. Examples of the lower alkyl group include an alkyl group having 1 to 6, preferably 1 to 4 carbon atoms. The aryl group has 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms, such as a phenyl group. Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, diglycolic acid and the like.

In producing the polymer of the present invention, an aliphatic diol is used as a main reaction material. This is represented by the following general formula (2).

Embedded imageIn the above formula, R^TwoHas 1 to 12 carbon atoms, preferably 2 to 10 carbon atoms.
Represents a divalent aliphatic group. In this case, the divalent aliphatic group has a chain
Or cyclic, and can be saturated or unsaturated.
It can be Japanese. In addition, this divalent aliphatic
The group has a hetero atom such as oxygen in addition to carbon in its main chain.
It can also be contained. Preferred divalent fat used in the present invention
The aliphatic group has 1 to 12 carbon atoms, preferably 2 to 10 carbon atoms.
Alkylene group or alkene which may contain a ter bond
Nylene group, alkyleneoxy group or oxyalkylene
And the like. As a specific example, -CH_Two-, -C_TwoH
_Four-, -C_ThreeH₆-, -C_FourH_Three-, -C₆H₁₂-, -C₈H
₁₆-, -C₁₂H_{twenty four}-, -C₁₂H _{twenty two}-(Dodecenyl),-
C₆H_Ten-(Cyclohexenyl), -CH_TwoO-, -CH
_TwoOCH_Two-And the like. As a concrete example,
For example, ethylene glycol, diethylene glycol,
Pyrene glycol, dipropylene glycol, 1,4-
Butanediol, 1,6-hexanediol, 1,4-
Cyclohexanedimethanol, polyethylene glycol
And polypropylene glycol.

In the present invention, if necessary, at least two functional groups reactive with the fatty acid dicarboxylic acid or its diester and / or aliphatic diol may be added to the reaction raw material as an auxiliary component. At least one compound selected from the aliphatic and / or aromatic compounds contained therein can be added. Such auxiliary components include oxycarboxylic acid compounds, carbonates, trihydric or higher polyhydric alcohols, polyoxyalkylene glycols, and the like.

The oxycarboxylic acid compounds include compounds represented by the following general formulas (3) and (4).

Embedded image

Embedded image In the general formula (3), R ³ has 1 to 10 carbon atoms;
It preferably represents 2 to 8 divalent aliphatic groups. In this case, the valent aliphatic group may be any of those described for R ¹ and R ² . R ¹² represents hydrogen, a lower alkyl group or an aryl group. As the lower alkyl group, one having 1 carbon atom
To 6, preferably 1 to 4, alkyl groups. The aryl group has 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms.
, For example, a phenyl group. Examples of the oxycarboxylic acid (3) include glycolic acid, lactic acid, hydroxyalkyl acid, α-oxy acid, and butyric acid.
Further, the oxycarboxylic acid may be a cyclic diester (lactide) having two molecules bonded thereto. Specific examples thereof include those obtained from glycolic acid (glycolide) and those obtained from lactic acid.

In the above general formula (4) representing a lactone compound, R ³ has 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms.
Represents a linear or cyclic divalent aliphatic group. In this case, the divalent aliphatic group includes a saturated or unsaturated alkylene group. Examples of the lactone include caprolactone, valerolactone, laurolactone and the like.

The carbonate ester is represented by the following general formula (5).

Embedded image In the above formula, R ¹³ and R ¹⁴ represent a lower alkyl group or an aryl group. When both R ¹³ and R ¹⁴ are a lower alkyl group, they may be linked to each other to form a ring. Examples of the lower alkyl group include an alkyl group having 1 to 6, preferably 1 to 4 carbon atoms. As the aryl group, C6 to C6
10, preferably 6 to 8, such as a phenyl group.

The polyhydric alcohol is an aliphatic compound having three or more hydroxyl groups. Such polyhydric alcohols include glycerin, diglycerin, polyglycerin compounds, pentaerythritol and the like. The upper limit of the number of hydroxyl groups contained in the polyhydric alcohol is not particularly limited, but is usually about 6.

The polyglycerin compound is represented by the following general formula (6).

Embedded image In the formula, R ⁶ represents hydrogen or an acyl group, and n represents an average degree of polymerization of glycerin. The acyl group includes an aliphatic acyl group represented by the following general formula (7).

Embedded image In the above formula, R ¹⁶ is an aliphatic group having 1 to 2 carbon atoms.
0, preferably 1-20, preferably 1-6. Specific examples include methyl, ethyl, propyl, butyl, hexyl, dodecyl, octadecyl and the like. The average degree of polymerization n of glycerin is 3 or more, and the upper limit is 30.
It is about. Generally, n is 3-10.

The polyoxyalkylene glycol is
It is represented by the following general formula (8).

Embedded image In the above formula, AO represents an alkyleneoxy group having 2 to 4 carbon atoms, and specific examples thereof include ethyleneoxy, propyleneoxy, butyleneoxy, and a mixed alkyleneoxy thereof. M represents an average degree of polymerization of (AO), and represents a number of 2 to 10, preferably 2 to 5.

In the present invention, in addition to the above compounds, oxypolycarboxylic acids such as malic acid and citric acid, diisocyanate, orthoformate, terephthalic acid, polyethylene terephthalate and the like can be used as the auxiliary components. .

The auxiliary component is used for the purpose of controlling the biodegradability and physical properties of the produced polymer. Its usage is
The molar fraction is 0.3 or less, preferably 0.2 or less, based on all monomer components such as dicarboxylic acids and diesters contained in the resulting polymer.

In the reaction raw material comprising a mixture of the aliphatic dicarboxylic acid or the diester thereof, the aliphatic diol and the optional auxiliary component used in the present invention, the proportion of the aliphatic diol used is included in the reaction raw material. The ratio is 1 to 2 mol, preferably 1.02 to 1.6 mol, per 1 mol of all carboxylic acids or diesters thereof.

The proportion of the oxycarboxylic acid-based compound used in the present invention is determined by the molar ratio of the ester portion (oxycarboxylic acid ester portion) derived from the oxycarboxylic acid-based compound to the total ester portion contained in the resulting polymer. Fraction 0.02. ~ 0.3, preferably 0.05 ~ 0.2
It is a ratio that falls within the range.

The proportion of the carbonate ester used in the present invention is such that the mole fraction of the ester portion (carbonate portion) derived from the carbonate ester to the total ester portion contained in the produced polymer is 0.02 to 0%. 0.3, preferably 0.
The ratio is in a range of from 0.5 to 0.2.

The proportion of the oxycarboxylic acid compound used in the present invention, such as glycolic acid, diglycolic acid or an ester thereof, is derived from the oxycarboxylic acid compound with respect to all the ester portions contained in the resulting polymer. The molar ratio of the ester moiety is in the range of 0.02 to 0.3, preferably 0.05 to 0.2.

The use ratio of the polyhydric alcohol used in the present invention is such that the mole fraction of the ester portion derived from the polyhydric alcohol with respect to the total ester portion contained in the produced polymer is 0.0005 to 0.005; Preferably 0.001
The ratio is in the range of 0.004 to 0.004.

In the case of terephthalic acid or polyethylene terephthalate used as an auxiliary component in the present invention, the molar ratio of terephthalic acid units to all ester parts is 0.01 to 0.35, preferably 0.05 to 0. .20
It is a ratio that falls within the range.

The reaction raw material used in the present invention can be composed of at least one selected from the oxycarboxylic acid compounds represented by the general formulas (3) and (4). This reaction raw material contains at least one selected from aliphatic and / or aromatic compounds containing at least two functional groups reactive with the oxycarboxylic acid compound, if necessary. can do. The auxiliary components include carbonate esters, trihydric or higher polyhydric alcohols, polyoxyalkylene glycols, and the like. Specific examples thereof include those described above. In addition, malic acid,
Oxypolycarboxylic acids such as citric acid, diisocyanate, orthoformate, terephthalic acid, polyethylene terephthalate and the like can be used. The auxiliary component is used for the purpose of controlling the biodegradability and physical properties of the produced polymer. The amount used is such that the molar ratio with respect to all the monomer components contained in the resulting polymer is 0.3 or less, preferably 0.2 or less.

In the present invention, when the reaction raw materials are subjected to a polycondensation reaction, (i) a catalyst for transesterification reaction and (ii) an organic phosphonic acid or sulfonic acid represented by the general formula (I) as a cocatalyst. At least one protonic acid selected from an aliphatic and / or aromatic compound having a sulfuric acid group or a sulfuric ester group and sulfuric acid is used. In the general formula (I) representing an organic phosphonic acid, the aliphatic group includes
It includes linear and cyclic ones, and has 1 to 1 carbon atoms.
2, preferably 1 to 10. The aromatic group includes an aryl group having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, preferably 7 to 10 carbon atoms. Specific examples of the organic phosphonic acid include phenylphosphonic acid, benzylphosphonic acid, methylphosphonic acid, n-butylphosphonic acid, and cyclohexylphosphonic acid.

In the aliphatic and / or aromatic compounds having a sulfonic acid group or a sulfuric ester group, examples of the aliphatic group and the aromatic group include those described for the organic phosphonic acid. Specific examples of such a protonic acid include p-toluenesulfonic acid, dimethyl sulfate, diethyl sulfate, and ethyl sulfate.

The protonic acid used as a co-catalyst in the present invention exhibits an excellent action as a co-catalyst component for producing an aliphatic polyester-based polymer, and is combined with a conventionally commonly used catalyst such as titanium tetraisopropoxide. This gives industrially advantageous results such as shortening the polymerization time and suppressing the generation of by-products such as tetrahydrofuran.

The amount of the protonic acid used as a cocatalyst in the present invention is 0.01 to 0.5, preferably 0.01 to 0.4 in terms of a molar ratio with respect to the transesterification catalyst.

As the catalyst for transesterification (esterification catalyst) used in the present invention, various conventionally known catalysts are used. Examples of such a transesterification catalyst include lithium, alkali metals such as potassium, magnesium, calcium, alkaline earth metals such as barium, and the like.
Typical metals such as tin, antimony, and germanium; transition metals such as lead, zinc, cadmium, manganese, cobalt, nickel, zirconium, titanium, and iron; lanthanide metals such as bismuth, niobium, lanthanum, samarium, europium, erbium, and ytterbium; Of various metals, alcoholates, acetylacetonate chelates and the like. Also, boric acid, boric acid ester and the like can be used as a catalyst.

Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate,
Potassium acetate, lithium acetate, sodium stearate, lithium stearate, sodium borohydride,
Lithium boron hydroxide, sodium borohydride,
Examples thereof include lithium benzoate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and lithium dihydrogen phosphate.

Specific examples of the alkaline earth metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, and calcium carbonate. , Barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate and the like.

Specific examples of the typical metal compound include dibutyltin oxide, dibutyltin dilaurate, antimony trioxide, germanium oxide, bismuth carbonate, and bismuth acetate.

Specific examples of the transition metal compound include lead acetate, zinc acetate, zinc acetylacetonate, cadmium acetate, manganese acetate, manganese acetylacetonate, cobalt acetate, cobalt acetylacetonate, nickel acetate, nickel acetylacetate. And zirconium acetate, zirconium acetylacetonate, titanium acetate, tetraptoxytitanate, tetraisopropoxytitanate, titanium oxyacetylacetonate, iron acetate, iron acetylacetonate, and niobium acetate.

Examples of the rare earth compound include lanthanum acetate, samarium acetate, europium acetate, erbium acetate, ytterbium acetate and the like.

Specific examples of the borate ester include trimethyl borate, trihexyl borate, triheptyl borate, triphenyl borate, tritolyl borate, and trinaphthyl borate.

These transesterification catalysts may be used alone or in combination of two or more. The catalyst is used in a proportion of 10 ⁻⁷ to 10 ⁻² mol, preferably 10 ^{−4 to} 5 × 10 ⁻³ mol, per 1 mol of the total amount of the carboxyl group-containing compound contained in the reaction raw material. Is preferred. If the amount of the catalyst is less than this range, the reaction does not proceed well and the reaction requires a long time. If it exceeds this range, it causes thermal decomposition, cross-linking, coloring and the like of the polymer during polymerization, and also causes thermal decomposition and the like in the molding process of the polymer, which is not preferable.

In one method for producing an aliphatic polyester-based polymer according to the present invention, a reaction raw material is heated in the presence of a transesterification catalyst and a protonic acid as a cocatalyst to cause a polycondensation reaction. In this reaction, water and OH-containing compounds (such as alcohol) are by-produced.
The reaction temperature is determined when the reaction by-product is methanol.
The reaction temperature under normal pressure is 100 to 300 ° C, preferably 1 to 300 ° C.
20-250 ° C. When the by-product is water, the reaction temperature under normal pressure is 130 to 300 ° C, preferably 145 ° C.
２５０250 ° C. The reaction pressure is normal pressure, reduced pressure or slightly increased pressure, but is preferably normal pressure. In the present invention, by-products generated in the reaction are removed from the reaction system. To this end, the reaction is carried out under conditions of temperature and pressure at which water or an OH-containing compound as a by-product is maintained in a gas phase, and the by-product in the gas phase is reduced in pressure in the reaction system. The gas is discharged from the reaction system by flowing nitrogen gas. In addition, the reaction is performed using a reactor (reactive distillation column) to which a distillation column is connected, and by-products produced by the reaction are continuously discharged from the distillation column. In such a reaction, in order to efficiently obtain a high molecular weight polymer, the reaction proceeds to a certain extent, and when 90% of the calculated amount of by-products (water or alcohol such as methanol) is obtained, the reaction is stopped. It is preferable to conduct polycondensation while removing the aliphatic diol by changing the reaction conditions such as raising the temperature or reducing the pressure.
The reaction conditions in this case are conditions in which the aliphatic diol to be eliminated exists as a gas, and can be formed by adjusting the temperature and pressure.

Another method for preferably producing an aliphatic polyester polymer according to the present invention is a pre-polycondensation step (first method).
Step) and a step of increasing the molecular weight of the preliminary polycondensate (second step). In the preliminary polycondensation step, the reaction raw material is subjected to a polycondensation reaction in the presence of the catalyst and its cocatalyst. The reaction temperature is
This is the temperature at which by-products produced by the reaction exist as gases in the reaction system. The reaction pressure is normal pressure, reduced pressure or slightly increased pressure, but is preferably normal pressure. By-products generated in this reaction are removed from the reaction system. In this reaction, the by-product (water or alcohol) in the reaction product is 70 to 97% of the calculated amount, preferably 90 to 95%.
%, The reaction temperature is raised and polycondensation is carried out under reduced pressure. The pre-polycondensation time in this case is 1 hour to 5 hours. As a method for charging the co-catalyst, a method in which the co-catalyst is charged in the presence of the catalyst at the start of the precondensate (oligomer) formation reaction is preferable.

Next, in order to carry out a high molecular weight reaction of the pre-polycondensation reaction product obtained as described above, the reaction is continued with or without the addition of a transesterification catalyst to the reaction product. . This high molecular weight process is a process in which aliphatic glycol bonded to the terminal of the low molecular weight condensate is condensed while elimination to form a high molecular weight condensate. By this process, the number average molecular weight is 4 More than 10,000 condensates can be produced. The reaction conditions in this case may be any conditions under which the by-produced aliphatic glycol can exist as a gas. This high molecular weight process can be performed in the same apparatus as the reaction apparatus for performing the prepolymerization step or in the main polymerization apparatus having high stirring efficiency. When the same apparatus is used, after the completion of the precondensation reaction, the reaction conditions may be changed, for example, the reaction temperature may be increased and the reaction pressure may be decreased to carry out the condensation reaction of the precondensate. The reaction pressure is from normal pressure to reduced pressure, but it is preferable to use reduced pressure. When employing reduced pressure, the pressure is usually 0.005 to 5 T
orr, preferably 1 Torr or less. The lower limit of the pressure is not particularly limited, but is usually 0.01 to 1T.
orr. The reaction time is about 90 to 600 minutes.

The molar ratios of the reaction raw material components such as the aliphatic dicarboxylic acid component and the aliphatic diol component in the reaction raw materials in the present reaction are as follows. 1.0 ≦ (B) / (A) ≦ 1.6 0.02 ≦ (C + D) / (A + C) ≦ 0.30 0.02 ≦ (A + D) / (A + C) ≦ 0.20 In the above formula, A) is the number of moles of the aliphatic dicarboxylic acid or ester thereof, (B) is the number of moles of the aliphatic diol, C is the number of moles of the oxycarboxylic acid-based compound, D is the other carboxyl group-containing compound and carbonate ester. Shows the number of moles of the system compound used.

One embodiment of the polymer of the present invention is represented by the following general formula (9)

Embedded image And an ether group-containing ester moiety represented by the following general formula (10)

Embedded image The oxycarboxylic acid ester moiety represented by
01 to 0.3, preferably 0.05 to 0.2, and / or the following general formula (11)

Embedded image The molar ratio of the carbonate portion represented by
3, preferably in a ratio of 0.05 to 0.2.

Another embodiment of the polymer of the present invention is represented by the following general formula (12)

Embedded image And an oxycarboxylic acid ester moiety represented by the following general formula (13)

Embedded image The molar ratio of the carbonate portion represented by
3, preferably in a ratio of 0.05 to 0.2.

The polymer of the present invention has a substantially linear structure and no gel structure, and has a number average molecular weight of 20,000 or more, preferably 40,000 or more. The upper limit of the number average molecular weight is about 8. The polymer of the present invention is a polymer having good chemical recyclability since it has biodegradability and can recover raw materials by alcohol decomposition or hydrolysis.

[0046]

Next, the present invention will be described specifically with reference to examples and comparative examples. Various physical property values of the aliphatic polyester were measured by the following methods. (Molecular weight and molecular weight distribution) A calibration curve was prepared from standard polystyrene using gel permeation chromatography (GPC), and the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) were determined. Was. As an eluent, chloroform was used. (Thermal Properties) The melting temperature and the glass transition point were determined by a differential scanning calorimeter (DSC). The thermal decomposition temperature was determined by a thermogravimetric analyzer (TG).

Comparative Example 1 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, and 0.12 mmol of titanium tetraisopropoxide were charged into a four-necked flask having a capacity of 100 ml with stirring blades, and 140 ° C. under a nitrogen atmosphere. And the temperature was gradually raised to 240 ° C. to drain water (about 1 hour). Then, gradually reduce the pressure while stirring, and add 0.0
The reaction was continued at 1-0.5 Torr for 3.3 hours. After the reaction, the molecular weight of the obtained polymer was measured.
Mw / Mn was 1.97 with 63,000.

Example 1 Polycondensation was carried out for 1.5 hours under the same conditions as in Comparative Example 1 except that 0.04 mmol of phenylphosphonic acid was added. Mn of the obtained polymer was 65,000, and Mw / Mn was 1.
87. It was found that the polymerization time was shortened by the coexistence of the organic phosphonic acid, and a high molecular weight polyester having a molecular weight equal to or higher than that was obtained. The melting point of the polymer was 116 ° C.

Example 2 Polycondensation was carried out for 1.5 hours under the same conditions as in Comparative Example 1 except that 0.015 mmol of phenylphosphonic acid was added.
Mn of the obtained polymer was 57,000, and Mw / Mn was 1.88. It was found that the coexistence of the phosphonic acid shortened the polymerization time and gave a high molecular weight polyester having the same molecular weight.

Example 3 Polycondensation was carried out for 12.8 hours under the same conditions as in Comparative Example 1 except that 0.04 mmol of paratoluenesulfonic acid was added. Mn of the obtained polymer was 59,000, and Mw / Mn
Was 1.86. It was found that the coexistence of p-toluenesulfonic acid shortened the polymerization time and gave a high-molecular-weight polyester having the same molecular weight.

Example 4 Polycondensation was carried out for 3.1 hours under the same conditions as in Comparative Example 1 except that 0.04 mmol of sulfuric acid was added and the reaction temperature was changed to 135 ° C. The Mn of the obtained white polymer was 57,000.
w / Mn was 1.76. It was found that the polymerization time was shortened by the coexistence of sulfuric acid, and a high molecular weight polyester was obtained.

[0052]

The aliphatic polyester polymer of the present invention has an increased heat resistance (melting temperature),
It has good mechanical strength and workability, and can be advantageously used as a molding material. Further, by using a small amount of organic phosphonic acid or sulfuric acid as a co-catalyst, the polymerization time can be shortened, and a polymer having a high molecular weight can be synthesized, which has an effect of improving the production cost. Moreover, this high molecular weight aliphatic polyester has biodegradability and chemical recyclability based on the aliphatic ester bond.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor So An 1-1-1, Higashi, Tsukuba, Ibaraki Pref. Institute of Industrial Science and Technology (72) Inventor Kazuo Nakayama 1-1-1, Higashi, Tsukuba, Ibaraki Pref. Satoshi Morikawa, Examiner, National Institute for Materials Technology (56) References JP-A-8-143656 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/81

Claims (10)

(57) [Claims] 1. Use of (i) a mixture of an aliphatic dicarboxylic acid or a diester thereof and an aliphatic diol or (ii) a precondensate of the mixture as a reaction raw material, wherein the reaction raw material is used in the presence of a transesterification catalyst. In the polycondensation reaction, a co-catalyst for the catalyst is represented by the following general formula (I): O = P (OH) ₂ R (I) (wherein, R represents an aliphatic group or an aromatic group). Aliphatic polyester polymer characterized by using at least one protonic acid selected from aliphatic and / or aromatic compounds having an organic phosphonic acid, sulfonic acid group or sulfate group, and sulfuric acid Manufacturing method. 2. The process according to claim 1, wherein the molar ratio of said protonic acid to said transesterification catalyst is in the range of 0.01 to 0.5. 3. The reaction raw material comprises (i) an aliphatic dicarboxylic acid or a diester thereof, an aliphatic diol, and an auxiliary component, wherein the auxiliary component is the aliphatic dicarboxylic acid or a diester thereof and / or the aliphatic diol. At least one selected from aliphatic and / or aromatic compounds containing at least two functional groups reactive with
3. A process as claimed in claim 1 or 2, wherein a seed mixture or (ii) a precondensate of the mixture is used. 4. The method according to claim 3, wherein the auxiliary component is at least one selected from oxycarboxylic acid compounds, carbonates, trihydric or higher polyhydric alcohols, and polyoxyalkylene glycols. 5. The method according to claim 1, wherein the ratio of the auxiliary component is in a range of 0.3 or less in terms of a molar ratio with respect to all monomer components contained in the produced polymer. 6. A method in which (i) an oxycarboxylic acid-based compound or (ii) a precondensate thereof is used as a reaction raw material and the reaction raw material is subjected to a polycondensation reaction in the presence of a transesterification catalyst. As a catalyst, an organic phosphonic acid, a sulfonic acid group or a sulfate ester represented by the following general formula (I) O = P (OH) ₂ R (I) (wherein, R represents an aliphatic group or an aromatic group) A process for producing an aliphatic polyester polymer, comprising using at least one protonic acid selected from aliphatic and / or aromatic compounds having a group and sulfuric acid. 7. The process according to claim 6, wherein the molar ratio of the protonic acid to the transesterification catalyst is in the range of 0.01 to 0.5. 8. The reaction raw material comprising (i) an oxycarboxylic acid compound and an auxiliary component, wherein the auxiliary component has at least two functional groups reactive with the oxycarboxylic acid compound. 8. The method according to claim 6, wherein a mixture of at least one selected from the group consisting of a system and / or an aromatic compound or (ii) a precondensate of the mixture is used. 9. The method according to claim 6, wherein the auxiliary component is at least one selected from a carbonic ester, a trihydric or higher polyhydric alcohol and a polyoxyalkylene glycol. 10. The method according to claim 9, wherein the molar ratio of the auxiliary component to the oxycarboxylic acid compound is 0.3 or less.