JP2002187943A - Production method for aliphatic polyester polymer, and aliphatic polyester polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide for industrially advantageously producing an aliphatic polyester polymer excellent in mechanical strengths and color tone at a highly practical polymerization rate. SOLUTION: A mixture (1) of at least one aliphatic dicarboxylic acid compound selected from among aliphatic dicarboxylic acids and their diesters and anhydrides with an aliphatic diol or a precondensate (11) of the mixture (1) is used as a reaction material. The material is subjected to polycondensation in the presence of a reaction catalyst comprising a metal-containing transesterification catalyst and a cocatalyst, thus giving the objective aliphatic polyester polymer. The cocatalyst comprises at least one phosphorus compound selected from among organic phosphinic acids, hydrogen-containing ammonium phosphate salts, hydrogen-containing ammonium polyphosphate salts, hydrogen- containing calcium phosphate salts, and hydrogen-containing calcium polyphosphate salts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aliphatic polyester polymer having excellent mechanical strength and color tone, and an aliphatic polyester 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, these synthetic polymers are not decomposed in the natural environment and must be disposed of. Environmental problems have become apparent with the increase in polymers. For this reason, biodegradable plastics are being developed, and aliphatic polyesters are receiving attention as biodegradable polymers. However, conventional aliphatic polyesters have many problems to be solved in terms of mechanical strength, cost, and the like. For example, polyhydroxybutyrate is a polyester having a high melting temperature and good performance. However, 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 to cause problems such as deterioration of performance and generation of odor.
Moreover, since it is a polymer produced using microorganisms, productivity is low and cost is high. Polycaprolactone is one of the few aliphatic polyesters currently being industrially produced, but its melting temperature of about 60 ° C. limits its use. In addition, hydroxycarboxylic acid polymers are attracting attention as polymers with good biodegradability, and in particular, lactic acid polymers are biocompatible polymers such as those used in bioabsorbable materials, but the manufacturing process is complicated. It is.

In order to solve the above-mentioned problems relating to the production and performance of aliphatic polyesters, polyesters obtained by the polycondensation of aliphatic dicarboxylic acids or derivatives thereof (esters, acid anhydrides, etc.) with glycols have attracted attention. . The method for producing this polyester has been known for a long time, and the acids include succinic acid, adipic acid, suberic acid, sebacic acid,
A method has been reported in which dodecadicarboxylic acid or the like is used, and ethylene glycol, 1,4-butanediol, 1,6-cyclohexanediol, 1,4-cyclohexanedimethanol, or the like is used as the glycol. However, since all such polymers have a number average molecular weight of several thousands,
There is not enough mechanical strength for films and fibers.

For this reason, many methods for producing polyesters having a large molecular weight and high mechanical strength have been proposed. However, in any of these proposals, the production process is increased and the polymer performance is sometimes lowered. JP-A-4-189822 and JP-A-4-189
No. 823 discloses a method of producing an aliphatic polyester having a number average molecular weight of about 15,000 from an aliphatic dicarboxylic acid or a derivative thereof and a glycol, and crosslinking the resulting aliphatic polyester with diisocyanate to increase the molecular weight. 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-287042, a polymer having a high molecular weight and a wide molecular weight distribution is obtained by copolymerizing an aliphatic dicarboxylic acid, a glycol and a polyvalent isocyanate. This polymer has a high molecular weight, a high mechanical strength, and a high melt viscosity due to a wide molecular weight distribution, and is suitable for producing a molded article such as a film. For the same purpose, JP-A-5-287068 discloses, in addition to the above three components,
Japanese Patent Application Laid-Open No. 5-295071 discloses a four-component copolymer to which 3,4,4-benzophenonetetracarboxylic anhydride is added, and a four-component copolymer to which a polyhydric alcohol such as pentaerythritol is added in addition to the above three. Polymers have been proposed. However, these copolymers have problems such as formation of a gel. In addition, JP-A-6-192374 discloses that
A low molecular weight aliphatic polyester is synthesized from an aliphatic dicarboxylic acid, a glycol and a polyhydric alcohol or a polyhydric carboxylic acid, and is reacted with an aliphatic polyester having an isocyanate group at a terminal thereof. Have been proposed. However, this method has a disadvantage that the number of manufacturing steps is further increased.

In the process for producing an aliphatic polyester polymer, a general catalyst for transesterification such as titanium tetraisopropoxide is used. However, in the case of this catalyst, the polyesterification reaction rate is still insufficient, and there is a problem of coloring of the obtained polymer. Furthermore, there is a problem to be improved in practical use such as insufficient mechanical properties of the obtained polymer, particularly, elongation at break, for applications such as various films and yarns. 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.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for industrially advantageously producing an aliphatic polyester-based polymer having excellent mechanical strength and color tone at a practically high polymerization rate, and is obtained by the method. An object of the present invention is to provide an aliphatic polyester-based polymer.

[0007]

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 at least one aliphatic dicarboxylic acid-based compound selected from aliphatic dicarboxylic acids, diesters and acid anhydrides thereof, and an aliphatic diol; In a method in which a precondensate of the mixture is used as a reaction material and the reaction material is subjected to a polycondensation reaction in the presence of a reaction catalyst comprising a metal-containing transesterification catalyst and a cocatalyst, an organic phosphinic acid, hydrogen-containing A method for producing an aliphatic polyester-based polymer, comprising using at least one phosphorus compound selected from ammonium phosphate, hydrogen-containing ammonium polyphosphate, hydrogen-containing calcium phosphate, and hydrogen-containing calcium phosphate. Provided. Also,
According to the present invention, (i) an oxycarboxylic acid-based compound or (ii) a precondensate thereof is used as a reaction raw material, and this reaction raw material is used in the presence of a reaction catalyst comprising a metal-containing transesterification catalyst and a cocatalyst. In the method of performing a condensation reaction, at least one phosphorus compound selected from organic phosphinic acid, hydrogen-containing ammonium phosphate, hydrogen-containing ammonium phosphate, hydrogen-containing calcium phosphate and hydrogen-containing calcium phosphate is used as the co-catalyst. There is provided a method for producing an aliphatic polyester-based polymer, which is used. Further, according to the present invention, there is provided an aliphatic polyester-based polymer obtained by the above method, which comprises the metal-containing transesterification catalyst and the co-catalyst. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION To produce a polymer of the present invention,
At least one aliphatic dicarboxylic acid-based compound selected from aliphatic dicarboxylic acids, esters and acid anhydrides thereof is used as the main reaction material. These are represented by the following general formula (1) (dicarboxylic acid or diester) or (2) (dicarboxylic anhydride), respectively.

Embedded image R ¹¹ OOC-R ¹ —COOR ¹¹ (1)

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 8 -, - C} 6 H 12 -, - C 8 H 16 -, - C 12 H
_{24 -, - C 12 H 22} - , and the like. The general formula (1)
In the formula, R ¹¹ represents hydrogen, a lower alkyl group or an aryl group. As the lower alkyl group, one having 1 to carbon atoms
6, preferably 1 to 4 alkyl groups. 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 succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, and diglycolic acid.

To produce the polymer of the present invention, an aliphatic diol is used as a main reaction material. This is represented by the following general formula (3).

Embedded image HO-R^Two—OH (3) In 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 optionally containing a ter bond
Nylene group, alkyleneoxy group or oxyalkylene
And the like. Specific examples of the divalent aliphatic group include -CH_Two
-, -C_TwoH_Four-, -C_ThreeH₆-, -C_FourH₈-, -C₆H₁₂
-, -C₈H₁₆-, -C₁₂H _{twenty four}-, -C₁₂H_{twenty two}-(Dode
Cenyl), -C₆H_Ten-(Cyclohexenyl), -CH_Two
O-, -CH_TwoOCH_Two-And the like. The general formula
Specific examples of the aliphatic diol represented by (3) include:
For example, ethylene glycol, diethylene glycol,
Propylene glycol, dipropylene glycol, 1,4
-Butanediol, 1,6-hexanediol, 1,4
-Cyclohexane dimethanol, polyethylene glycol
And polypropylene glycol.

In the present invention, if necessary, at least two functional groups reactive with the aliphatic dicarboxylic acid compound and / or the 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,
Terephthalic acid-based compound, trihydric or higher polyhydric alcohol, polyoxyalkylene glycol, orthoformate,
Flavonoids (polyphenols) and the like are included.

The oxycarboxylic acid compounds include compounds represented by the following general formulas (4) and (5).

Embedded image HO—R ³ —COOR ¹² (4)

Embedded image In the general formula (4), 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 (4) include glycolic acid, lactic acid, and α-oxybutyric 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 (5) 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 (6).

Embedded image R ¹³ OCOOR ¹⁴ (6) In the above formula, R ¹³ and R ¹⁴ represent a lower alkyl group or an aryl group, and when R ¹³ and R ¹⁴ are both lower alkyl groups, they are linked to each other. A ring may be formed. 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-based compounds, trimethylolpropane, pentaerythritol, triols of polyalkylene glycols, and furanovoids (polyphenols). The upper limit of the number of hydroxyl groups contained in the polyhydric alcohol is not particularly limited, but is usually about six.

The polyglycerin compound is represented by the following general formula (7).

Embedded image HO— [C ₃ H ₅ (OR ⁴ ) O] _n —H (7) In the formula, R ⁴ 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 (8).

Embedded image R ¹⁵ CO- (8) the formula, R ¹⁵ is an aliphatic group, the number of carbon atoms from 1 to 2
0, preferably 1 to 6. Specific examples include methyl, ethyl, propyl, butyl, hexyl, dodecyl, octadecyl and the like. The average degree of polymerization n of the glycerin is 2 or more, and the upper limit is about 30. Generally, n is 1-10.

The polyoxyalkylene glycol is
It is represented by the following general formula (9).

Embedded image HO (AO) _m H (9) In the above formula, AO represents an alkyleneoxy group having 2 to 4 carbon atoms, and specific examples thereof include ethyleneoxy, propyleneoxy, butyleneoxy and mixed alkylene thereof. Oxy and the like. 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-mentioned compounds, oxypolycarboxylic acids such as malic acid and citric acid, diisocyanates, orthoformate, phthalic acid, polyethylene terephthalate, and triols of polyalkylene glycol are used as the auxiliary components. Mold, furanovoid (polyphenol) and the like can be used.

In the reaction raw material comprising the aliphatic dicarboxylic acid compound and the aliphatic diol used in the present invention, the ratio of the aliphatic diol used is 2 to 1 per mole of the total carboxylic acid component contained in the reaction raw material. Mole, preferably 1.6 to 1.02 mole.

The ratio of the oxycarboxylic acid 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 compound to the total ester portion contained in the resulting polymer. The ratio is such that the fraction is in the range of 0.02 to 0.3, preferably 0.05 to 0.2.

In the present invention, the molar ratio of the carbonate ester derived from the carbonate (carbonate) relative to the total ester contained in the 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 terephthalic acid compound (terephthalic acid, ester or acid anhydride thereof) used in the present invention is determined by the ratio of the ester derived from the terephthalic acid compound to the total ester portion contained in the polymer to be produced. Part (terephthalic acid ester part) has a molar fraction of 0.01 to
The ratio is set to 0.2, preferably 0.05 to 0.1.

The proportion of the polyoxyalkylene glycol used in the present invention is such that the molar fraction of the ester portion derived from the polyoxyalkylene glycol relative to the total ester portion contained in the resulting polymer is 0.001.
To 0.3, preferably 0.01 to 0.2.

The proportion of diglycolic acid or an ester thereof used as an auxiliary component in the present invention is determined by the molar ratio of the ester portion derived from diglycolic acid (diglycolic acid ester portion) to the total ester portion contained in the polymer to be produced. The fraction is 0.001-0.3, preferably 0.01-0.2
It is a ratio that falls within the range.

The use ratio of the polyglycerin compound used in the present invention is such that the mole fraction of the ester portion (ether-containing ester portion) derived from the polyglycerin compound with respect to all the ester portions contained in the polymer to be produced. 0.
0001-0.005, preferably 0.001-0.0
04.

In the present invention, if necessary, auxiliary components (trimethylolpropane, pentaerythritol, glycerin, orthoformate, triol type of polyalkylene glycol, furanovoid (polyphenol) ) And other polycarboxylic acids having an oxy group such as malic acid, citric acid, etc.), the components derived from these auxiliary components with respect to all the ester moieties contained in the resulting polymerization couple (auxiliary The molar ratio of the component constituent portion) is in the range of 0.001 to 0.005, preferably 0.001 to 0.004. When the auxiliary component is diisocyanate, the molar ratio of the auxiliary component is in the range of 0.001 to 0.03, preferably 0.05 to 0.02.

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 (4) and (5). This reaction raw material is selected from an aliphatic compound and / or an aromatic compound containing at least two functional groups reactive with the oxycarboxylic acid compound as an auxiliary component, if necessary. At least one
Species can be included. The auxiliary components include carbonate esters, trihydric or higher polyhydric alcohols, polyoxyalkylene glycols, and the like. Specific examples thereof include those described above. Further, oxypolycarboxylic acids such as malic acid and citric acid, diisocyanate, orthoformate, terephthalic acid compounds, polyethylene terephthalate, triform type of polyalkylene glycol, and furanovoid (polyphenol) are used as other auxiliary components. Can be. 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 fraction is 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, based on the total monomer components contained in the polymer to be produced. Is good.

In the present invention, a combination of a metal-containing transesterification catalyst and a co-catalyst is used when the reaction raw materials are subjected to a polycondensation reaction. In this case, as the co-catalyst, at least one phosphorus compound selected from organic phosphinic acid, hydrogen-containing ammonium phosphate, hydrogen-containing ammonium phosphate, hydrogen-containing calcium phosphate and hydrogen-containing calcium phosphate is used. . The organic phosphinic acid can be represented by the following general formula (10).

Embedded image O = P (OH) R ₂ (10) In the above formula, R represents an aliphatic group or an aromatic group. In the general formula (10) representing the organic phosphinic acid, the aliphatic group includes a chain and a cyclic one, and has 1 to 12, preferably 1 to 10 carbon atoms. 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 phosphinic acid include phenylphosphinic acid, benzylphosphinic acid, methylphosphinic acid, n-butylphosphinic acid,
Cyclohexylphosphinic acid and the like can be mentioned. The hydrogen-containing ammonium phosphate includes diammonium hydrogen phosphate and ammonium dihydrogen phosphate. The hydrogen-containing calcium phosphate includes calcium dihydrogen phosphate and calcium dihydrogen phosphate. The hydrogen-containing polyphosphate includes a dehydrated condensate of a phosphate. In this polyphosphate, the degree of condensation (degree of polymerization) is 2 to 10, preferably 2 to 6, and more preferably 2 to 4.

The proportion of the cocatalyst used in the present invention is as follows:
The ratio of the phosphorus compound to the metal-containing transesterification catalyst is determined by the atomic ratio of metal atom to phosphorus atom M / P
(M: metal) is in the range of 0.01 to 0.8, preferably in the range of 0.2 to 0.5.

The cocatalyst used in the present invention exhibits an excellent action as a catalyst auxiliary component for producing an aliphatic polyester-based polymer, and is commonly used for a conventional metal-containing transesterification reaction of titanium tetraisopropoxide and the like. When used in combination with a catalyst for use, it has the effects of shortening the polymerization time and suppressing the formation of by-products such as tetrahydrofuran, and provides an industrially advantageous high molecular weight polyester polymer.

As the metal-containing transesterification catalyst (esterification catalyst) used in the present invention, various conventionally known catalysts can be used. As such a transesterification catalyst, lithium, alkali metals such as potassium, magnesium, calcium, alkaline earth metals such as barium, tin, antimony, typical metals such as germanium,
Various compounds of metals such as transition metals such as lead, zinc, cadmium, manganese, cobalt, nickel, zirconium, titanium and iron, lanthanum metals such as bismuth, niobium, lanthanum, samarium, europium, erbium and ytterbium, for example, alcoholates , Acetylacetonate chelate, acetate and the like.

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

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

In the present invention, it is particularly preferable to use a transition metal-based transesterification catalyst. As such transition metal compounds, specifically, lead acetate, zinc acetate, zinc acetylacetonate, cadmium acetate, manganese acetate,
Manganese acetylacetonate, cobalt acetate, cobalt acetylacetonate, nickel acetate, nickel acetylacetonate, zirconium acetate, zirconium acetylacetonate, titanium acetate, tetrabutoxytitanate, tetraisopropoxytitanate, titanium oxyacetylacetonate, iron acetate, Examples include iron acetylacetonate and niobium acetate.

These esterification catalysts may be used alone or in combination of two or more. The catalyst is used in an amount of 10 ^{-7 to} 0.5 mol, preferably 0.005 to 0.3 mol, more preferably 0.1 to 0.5 mol, based on 100 mol of the total amount of the carboxy group-containing compound contained in the reaction raw materials. 01
It is preferable to use it in a proportion of up to 0.15 mol. 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 polymer according to the present invention, the reaction raw materials are heated in the presence of a transesterification catalyst and its cocatalyst to cause a polycondensation reaction. In this reaction, water and OH-containing compounds (such as alcohols) are by-produced. When the reaction by-product is methanol, the reaction temperature under normal pressure is 100 to 300 ° C., preferably 120 to 300 ° C. 250 ° C. When the by-product is water, the reaction temperature under normal pressure is 1
The temperature is 30 to 300 ° C, preferably 140 to 250 ° 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 some extent and the calculated amount of by-products (water or alcohol such as methanol) is 90%.
%, It is preferable to conduct polycondensation while removing the aliphatic diol by changing the reaction conditions such as raising the reaction 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 the aliphatic polyester-based polymer of the present invention comprises a pre-polycondensation step (first step) and a high-molecular weight step (second step) for increasing the molecular weight of the pre-polycondensate. ). In the preliminary polycondensation step, the reaction raw materials are subjected to a polycondensation reaction in the presence of a cocatalyst (a phosphorus compound) and a catalyst. When a reaction material is subjected to a polycondensation reaction in the presence of the catalyst component, the reaction temperature is a temperature at which by-products produced by the reaction are present as a gas 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. When the reaction proceeds and 70-99%, preferably 90-99% of the calculated amount of by-products (water or alcohol) in the reaction product is obtained, the reaction temperature is raised and the polycondensation is carried out under reduced pressure. Let it. The pre-polycondensation time in this case is 1 hour to 5 hours. The co-catalyst component may be charged either at the start of the precondensate (oligomer) formation reaction or at the start of the polymerization reaction, but is preferably charged in the presence of a catalyst at the start of the oligomer formation reaction.

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. . In the high molecular weight step, the aliphatic glycol bonded to the terminal of the low molecular weight condensate is condensed while being eliminated to form a high molecular weight condensate. By this step, the weight average molecular weight becomes 16 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 typically between 0.005 and 5
Torr, preferably 2 Torr or less. Although the lower limit of the pressure is not particularly limited, it is usually 0.01 to 1
It is about Torr. The reaction time is about 90 to 600 minutes.

One embodiment of the polymer of the present invention is represented by the following general formula (11)

Embedded image (—CO—R ¹ —CO—O—R ² —O—) An ether group-containing ester moiety represented by the following formula (11) and the following general formula (12)

Embedded image (—CO—R ³ —O—) The oxycarboxylic acid ester moiety represented by (12) has a mole fraction of 0.5 or less, preferably 0.03 to 0.45, more preferably 0. 0.33 to 0.4 and / or the following general formula (13)

Embedded image (—OCOO—) The carbonate portion represented by (13) has a molar fraction of 0.5 or less, preferably 0.03 to 0.45, more preferably 0.03.
Include at a rate of ~ 0.4.

Another embodiment of the polymer of the present invention is represented by the following general formula (14)

Embedded image (—CO—R ³ —O—) An oxycarboxylic acid ester moiety represented by the following formula (14), and the following general formula (15)

Embedded image (—OCOO—) The carbonate portion represented by (15) has a mole fraction of 0.5 or less, preferably 0.03 to 0.45, more preferably 0.03.
Include at a rate of ~ 0.4.

Still another embodiment of the polymer of the present invention is represented by the following general formula (16):

Embedded image (—CO—R ¹ —CO—O—R ² —O—) A dicarboxylic acid ester portion represented by the following formula (16), and the following general formula (17)

Embedded image (—CO—R ¹ —CO—O—R ⁴ —O—) (17) An ether represented by the formula (wherein R ⁴ is an ether-containing divalent aliphatic group having 4 to 12 carbon atoms) The group-containing ester moiety is contained at a molar fraction of 0.5 or less, preferably 0.03 to 0.45, more preferably 0.03 to 0.4.

Still another embodiment of the polymer of the present invention is represented by the following general formula (18)

Embedded image (—COC ₆ H ₄ CO—) The terephthalic acid ester portion represented by (18) has a mole fraction of 0.0
01 to 0.2, preferably 0.005 to 0.1.

The polymer of the present invention has a substantially linear structure, or a branched structure by adding a crosslinking agent to the linear structure, and further has excellent color tone. Preferably, it has a weight average molecular weight of 100,000 or more, especially 160,000 or more. The upper limit of the molecular weight is usually about 300,000. Since the polymer of the present invention is an aliphatic polyester, it has biodegradability, and is also a polymer having good chemical recyclability since it is possible to recover raw materials by alcoholysis and hydrolysis. . The polyester polymer obtained by the method of the present invention contains the metal-containing transesterification catalyst and cocatalyst used in the reaction, and such a catalyst and cocatalyst may be separated from the polymer. However, the separation is costly, and in the case of the present invention, the content is very small, so that it is advantageous to use the product as it is without separation.

[0043]

Next, the present invention will be described specifically with reference to 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 weight average molecular weight (Mw), number average molecular weight, and molecular weight distribution (Mw / Mn) were determined. 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 230 ° C., and water was allowed to flow out (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued at a final ultimate vacuum of about 0.5 Torr for 1 hour and 20 minutes. After the reaction, when the molecular weight of the obtained polymer was measured, it was Mw 154,000 and Mw / Mn was 2.20.
Mn was 70,000.

Comparative Example 2 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, 0.12 mmol of titanium tetraisopropoxide and triammonium phosphate trihydrate were placed in a 100 ml four-necked flask with a stirring blade. _{(NH 4) 3 PO 4 ·} 3
0.02 mmol of H ₂ O was charged, and 1
The reaction was started at 40 ° C., the temperature was gradually raised to 240 ° C., and water was allowed to flow out (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued for 1 hour at a final ultimate vacuum of about 0.5 Torr. After the reaction, the molecular weight of the obtained white polymer was measured to be 44,000, and Mw / Mn was 2.
It was 14. Mn was 67,400.

EXAMPLE 1 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, 0.12 mmol of titanium tetraisopropoxide and diammonium hydrogen phosphate (NH ₄ ) ₂ HPO ₄ 0.
In a nitrogen atmosphere, the reaction was started at 140 ° C., the temperature was gradually raised to 240 ° C., and water was discharged (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued for 1 hour at a final ultimate vacuum of about 0.5 Torr. After the reaction, the molecular weight of the obtained white polymer (including the main catalyst and the co-catalyst, hereinafter the same) was measured.
Mw / Mn was 2.34. It was found that the molecular weight was improved when diammonium hydrogen phosphate was added as compared with the case where the ammonium phosphate salt was added in Comparative Examples 1 and 2. Mn was 86,000.

Comparative Example 3 The polycondensation was carried out under the same conditions as in Example 1 except that 0.04 mmol of disodium hydrogenphosphate Na ₂ HPO ₄ was added.
Time was 20 minutes. The weight average molecular weight of the obtained polymer was 1420,000 Mn, and Mw / Mn was 2.44.
The polyester was colored brown by the coexistence of disodium hydrogen phosphate Na ₂ HPO ₄ , and the molecular weight Mw was lower than that of Example 1.

Comparative Example 4 Polycondensation was carried out for 3 hours under the same conditions as in Example 2 except that 0.04 mmol of dipotassium hydrogen phosphate K ₂ HPO ₄ was added. The Mw of the obtained polymer was 196,000,
/ Mn was 2.37. The resulting polyester was brown. The polymer was colored by coexisting dipotassium hydrogen phosphate K ₂ HPO ₄ , and the molecular weight Mw was lower than that of Example 1.

Example 2 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, 0.12 mmol of titanium tetraisopropoxide and diammonium hydrogen phosphate (NH ₄ ) ₂ HPO ₄
0.04 mmol was charged, the reaction was started at 140 ° C. under a nitrogen atmosphere, the temperature was gradually raised to 240 ° C., and water was allowed to flow out (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued at a final ultimate vacuum of about 0.5 Torr for 2 hours. After the reaction, the molecular weight of the obtained white polymer was measured. As a result, Mw was 313,000 and Mw / Mn was 2.73.

Example 3 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, 0.12 mmol of titanium tetraisopropoxide and ammonium dihydrogen phosphate (NH _{4) were} placed in a four-necked flask having a capacity of 100 ml with stirring blades. ) H ₂ PO ₄
0.04 mmol was charged, the reaction was started at 140 ° C. under a nitrogen atmosphere, the temperature was gradually raised to 240 ° C., and water was allowed to flow out (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued for 1 hour at a final ultimate vacuum of about 0.5 Torr. After the reaction, when the molecular weight of the obtained white polymer was measured, it was Mw 164,000 and Mw / Mn was 2.19.

Example 4 180 mmol of succinic acid and 176.4 of 1,4-butanediol were placed in a 100 ml four-necked flask equipped with stirring blades.
Mmol, 19.6 mmol of diethylene glycol, 0.12 mmol of titanium tetraisopropoxide and 0.04 mmol of diphenylphosphinic acid (O = PPh ₂ (OH)), and the reaction was started at 140 ° C. under a nitrogen atmosphere, and gradually started. The temperature was raised to 230 ° C., and water was allowed to flow out (about 1 hour). Then, the pressure was gradually reduced while stirring, and the reaction was continued at a final ultimate vacuum of about 0.5 Torr for 2 hours and 18 minutes. After the reaction, when the molecular weight of the obtained white polymer was measured, it was Mw 160,000 and Mw / Mn was 2.01.

Example 5 180 mmol of succinic acid, 198 mmol of 1,4-butanediol, 0.12 mmol of titanium tetraisopropoxide and calcium hydrogen diphosphate CaH ₂ O _{7 were} placed in a 100 ml four-necked flask with stirring blades. 0.02 mmol of P ₂ was charged, the reaction was started at 140 ° C. under a nitrogen atmosphere, the temperature was gradually raised to 240 ° C., and water was allowed to flow out (about 1 μm).
time). Then, the pressure was gradually reduced while stirring, and the reaction was continued for 1 hour at a final ultimate vacuum of 0.5 Torr. After the reaction, the molecular weight of the obtained white polymer was measured.
Mw / Mn was 2.41 at w23.0.

[0053]

The aliphatic polyester polymer of the present invention has practically good mechanical strength and workability, and can be advantageously used as a molding material. In addition, the use of a small amount of a cocatalyst can shorten the polymerization time, and can provide a high molecular weight polymer having excellent color tone at a practically high polymerization rate.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Sao 1-1-1 Higashi, Tsukuba City, Ibaraki Prefecture Independent Administrative Law, National Institute of Advanced Industrial Science and Technology Tsukuba Center F-term (reference) BA02 BA03 BA04 BA05 BA08 BD07A BF09 BF10 BF23 BF25 CA02 CA04 CA06 CB06A EA02 EA03 EA05 EG07 EG09 EG10 EH02 EH03 FC02 FC03 FC05 FC08 HA01 HB01 HB02 HC04A HC05A HE01 JA091 JA121J231 J261 JB1131 J162 J261 JB131J182 J261 JB1131 JF161 JF181 JF191 JF271 JF321 JF331 JF371 JF381 JF431 JF471 JF541 JF561 JF571 KB04 KB05 KC03 KD02 KD07 KD09 KE02 KE08 LA04 LB02 LB08

Claims (13)

[Claims] (1) a mixture of at least one aliphatic dicarboxylic acid compound selected from aliphatic dicarboxylic acids, diesters and acid anhydrides thereof with an aliphatic diol, or (ii) a preliminary mixture of the mixture. In a method in which a condensate is used as a reaction raw material and the reaction raw material is subjected to a polycondensation reaction in the presence of a reaction catalyst comprising a metal-containing transesterification catalyst and a cocatalyst, an organic phosphinic acid and a hydrogen-containing ammonium phosphate are used as the cocatalyst. A method for producing an aliphatic polyester polymer, comprising using at least one phosphorus compound selected from a salt, a hydrogen-containing ammonium polyphosphate, a hydrogen-containing calcium phosphate, and a hydrogen-containing calcium phosphate. 2. The method according to claim 1, wherein the ratio of the phosphorus compound to the metal-containing transesterification catalyst is in the range of 0.01 to 0.8 in terms of the atomic ratio of metal atoms to phosphorus atoms. 3. The reaction raw material comprises (i) an aliphatic dicarboxylic acid compound, an aliphatic diol and an auxiliary component,
The auxiliary component is at least one selected from aliphatic and / or aromatic compounds containing at least two functional groups reactive with the aliphatic dicarboxylic acid compound and / or the aliphatic diol. 3. The process according to claim 1, wherein a mixture of one kind 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, terephthalic acid compounds, trihydric or higher polyhydric alcohols, and polyoxyalkylene glycols. Method. 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 comprising using (i) an oxycarboxylic acid-based compound or (ii) a precondensate thereof as a reaction material, and reacting the reaction material in the presence of a reaction catalyst comprising a metal-containing transesterification catalyst and a cocatalyst. In the method of performing a condensation reaction, at least one phosphorus compound selected from organic phosphinic acid, hydrogen-containing ammonium phosphate, hydrogen-containing ammonium phosphate, hydrogen-containing calcium phosphate and hydrogen-containing calcium phosphate is used as the co-catalyst. A method for producing an aliphatic polyester polymer, which is used. 7. The method according to claim 6, wherein the ratio of the phosphorus compound to the metal-containing transesterification catalyst is in the range of 0.01 to 0.8 in the atomic ratio of the metal atom to the phosphorus atom. 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 1, wherein the auxiliary component is at least one selected from a carbonate ester, a terephthalic acid compound, a trihydric or higher polyhydric alcohol and a polyoxyalkylene glycol.
9. The method of any of claims 6 to 8, which is a seed. 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. 11. The ratio of the metal-containing transesterification catalyst is 10 ^{-7 to} 0.5 mol per 1 mol of the total amount of all carboxyl group-containing compounds contained in the reaction raw material. The method according to any one of 1 to 10. 12. The method according to claim 1, wherein the aliphatic polyester polymer has a weight average molecular weight of 160,000 or more. 13. An aliphatic polyester-based polymer obtained by the method according to claim 1, which comprises the metal-containing transesterification catalyst and the cocatalyst. .