JP3521231B2 - Process for producing biodegradable high molecular weight aliphatic polyester having ether side chain - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to 3-alkoxy-1,2
The present invention relates to a method for producing a high elongation biodegradable high molecular weight aliphatic polyester containing a propanediol moiety. 2. Description of the Related Art Synthetic polymers such as polyolefins and aromatic polyesters are used in large quantities as raw materials indispensable for daily life, but these synthetic polymers are not decomposed in the natural environment. However, environmental problems have become apparent with the increase in consumption. For this reason, biodegradable plastics are being developed, and aliphatic polyesters are receiving attention as biodegradable polymers. Among them, polybutylene succinate produced from succinic acid or a derivative thereof and butanediol has been noted for its excellent melting point and mechanical strength (Japanese Patent Application Nos. 5-70566 and 9-126).
91, Japanese Patent Application No. 9-13259). However, since polybutylene succinate alone does not always provide sufficient mechanical strength and workability for practical use, improvement of physical properties by copolymerization with various polyhydric alcohols, hydroxy acids, and the like has been studied. 9-3117
6, Japanese Patent Application No. 9-40762, etc.)
By copolymerizing alkoxy-1,2-propanediol with an aliphatic dicarboxylic acid diester and an aliphatic glycol, a high molecular weight aliphatic polyester having a novel structure exhibiting a higher elongation than a homopolymer was proposed (Patent No. 30).
66500). [0004] The present invention relates to the above-mentioned patent.
By improving the method for producing a high molecular weight aliphatic polyester presented in No. 3066500, alkoxy-1,2
-Provide a process for industrially advantageously producing a biodegradable high molecular weight aliphatic polyester which is capable of copolymerizing propanediol without lowering the molecular weight, has high breaking stress and high elongation at break, and has excellent processability. That is the task. 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, the following general formula (1)
An aliphatic dicarboxylic acid represented by the following formula: (Wherein, R ¹ represents a divalent aliphatic group having 1 to 12 carbon atoms) or an aliphatic dicarboxylic anhydride represented by the following general formula (2): (Wherein R ¹ is the same as described above) or a mixture thereof, an aliphatic diol represented by the following general formula (3), and HO—R ² —OH (3) ⁽² represents a divalent aliphatic group having 1 to 12 carbon atoms.) 3-alkoxy-1,2-propanediol represented by the following general formula (4) is copolymerized: (Wherein R ³ represents an aliphatic group having 1 to 18 carbon atoms) having an ester portion A represented by the following general formula (5) and an ester portion B represented by the following general formula (6): ] (In the formula, R ¹ and R ² are the same as above. P represents the mole fraction of the ester moiety (A) represented by the general formula (5).) (In the formula, R ¹ and R ³ are the same as described above. R represents the mole fraction of the ester moiety (B) represented by the general formula (6).) The method for producing a biodegradable high molecular weight aliphatic polyester is as follows. Provided. The process for producing a high molecular weight fatty-side polyester according to the present invention comprises the steps of preparing an aliphatic dicarboxylic acid represented by the general formula (1), an aliphatic dicarboxylic anhydride represented by the general formula (2), or both. The mixture is subjected to a condensation reaction between an aliphatic diol represented by the general formula (3) and a 3-alkoxy-1,2-propanediol represented by the general formula (4). The proportion of the 3-alkoxy-1,2-propanediol used may be within a range such that the molecular weight of the target polymer is 10,000 or more, and is usually from 0.0005 to 1 per mol of the aliphatic dicarboxylic acid unit. 0.30 mol, preferably 0.0
It is a ratio of 01 to 0.20 mol. If the use ratio of 3-alkoxy-1,2-propanediol is more than the above range, the resulting polymer (polycondensate) is not preferable because the degree of polymerization does not increase and a fragile polymer is formed. The 3-alkoxy-1,2-propanediol represented by the general formula (3) can be obtained, for example, by reacting glycerin with an alcohol. Examples of the alcohol in this case include saturated and unsaturated alcohols having an aliphatic group having 1 to 22 carbon atoms. Examples of such alcohols include methyl alcohol, ethyl alcohol, butyl alcohol, octyl alcohol, lauryl alcohol, pentadecyl alcohol, stearyl alcohol, docosyl alcohol, allyl alcohol, crotyl alcohol, cyclopentanol, cyclohexanol and the like. No. The aliphatic dicarboxylic acid represented by the general formula (1) and the aliphatic dicarboxylic anhydride represented by the general formula (2) include succinic acid, adipic acid, suberic acid,
Examples thereof include aliphatic dicarboxylic acids such as sebacic acid and dodecane diacid, and acid anhydrides thereof. The aliphatic diol represented by the general formula (2) to be condensed with the aliphatic dicarboxylic acid represented by the general formula (1) includes ethylene glycol, propylene glycol, 1,4-butanediol, Examples include 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. The total number of moles of the aliphatic diol represented by the general formula (2) and the 3-alkoxy-1,2-propanediol represented by the general formula (3) is the same as that of the aliphatic dicarboxylic acid represented by the general formula (1). It is preferable to use an equimolar amount or a slight excess of the number of moles of the acid. The condensation reaction according to the present invention is preferably carried out in the presence of a conventionally known catalyst for transesterification.
In the above reaction, the reaction temperature is 100 to 300 ° C, preferably 120 to 270 ° C. The reaction pressure can be reduced pressure, normal pressure or slightly increased pressure (0.5 kg / cm ² G or less),
Preferably, the pressure is from normal pressure to reduced pressure. When the condensation reaction is carried out, the reaction is preferably carried out in two steps, a precondensation step (first step) and a high molecular weight step (second step). In the precondensation step, a low molecular weight condensate having an aliphatic diol bonded to a terminal is formed. The number average molecular weight of this condensate is 5000-10
The molecular weight may be appropriately adjusted depending on the reaction conditions and reaction time. In the high molecular weight step, the aliphatic diol bonded to the terminal of the low molecular weight condensate is condensed while being eliminated to form a high molecular weight condensate. Can produce more than 10,000 condensates. The reaction conditions in this case may be any conditions under which the by-produced aliphatic diol can exist as a gas. This molecular weight conversion step can be performed in the same apparatus as the reaction apparatus for performing the precondensation step or in a 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 biodegradable high molecular weight aliphatic polyester obtained by the method of the present invention comprises an ester moiety A represented by the above general formula (5).
And the ester moiety B of the general formula (6). In this case, in the general formula (5) representing the ester moiety A, R ¹ represents a linear or cyclic divalent aliphatic group, and has 1 to 12, preferably 2 to 6 carbon atoms. Examples of such a divalent aliphatic group include an alkylene group such as methylene, ethylene, propylene, butylene, hexylene, octylene, dodecylene, cyclohexylene, and cyclohexane dimethylene. R ² represents a chain or cyclic divalent aliphatic group, and has 1 to 12, preferably 2 to 6 carbon atoms. As such a divalent aliphatic group, an alkylene group, for example, methylene, ethylene, propylene,
Butylene, hexylene, octylene, dodecylene, cyclohexylene, cyclohexane dimethylene and the like can be mentioned. In the general formula (6) representing the ester moiety B, R ¹ has the same meaning as described above, and the aliphatic group R ³ represents an aliphatic group having 1 to 22 carbon atoms. Such aliphatic groups include alkyl or alkenyl groups, for example, methyl, ethyl, propyl, butyl, hexyl, octyl,
Nonyl, decyl, dodecyl, lauryl, stearyl, icosyl, docosyl, allyl, oleyl, behenyl, dodecenyl, cyclohexylene, cyclohexane dimethylene and the like. The high molecular weight polyester of the present invention has a number average molecular weight of 10,000 or more, preferably 30,000 or more. In this case, the upper limit of the number average molecular weight is about 1,000,000. The high-molecular-weight aliphatic polyester produced according to the present invention has a copolymerized structure with 3-alkoxy-1,2-propanediol, and has an elongation at break when a small amount of 3-alkoxy-1,2-propanediol is added. Mechanical strength such as degree can be greatly improved. Also, in this manufacturing method, the aforementioned patent No. 3066
Compared to the method described in No. 500, a large amount of 3-alkoxy-1,2-propanediol can be copolymerized without lowering the molecular weight, and the breaking stress and elongation at break are high, and a high molecular weight aliphatic having excellent processability. Polyester can be obtained. Moreover, the high molecular weight aliphatic polyester has biodegradability based on the aliphatic ester bond. Next, the present invention will be described specifically with reference to examples. Various physical properties 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)
I asked. The eluent used was chloroform. (Thermal Properties) Differential Scanning Calorimeter (DS)
The melting temperature and glass transition point were determined by C). The thermal decomposition temperature was determined by a thermogravimetric analyzer (TG). (Mechanical strength) Measured using a tensile tester. Example 1 Succinic acid (21.3 g, 0.181 mol) and 1,4-butanediol (16.8 g) were placed in a glass reactor having an internal capacity of 100 ml with stirring blades.
(0.186 mol), 0.639 g (1.85 mmol) of batyl alcohol (3-octadecyloxy-1,2-propanediol), 20 μl (0.1 mmol) of titanium tetraisopropoxide, 6.2 mg (0.036 mmol) of magnesium phosphate trihydrate And reacted at 160 ° C. for 1 hour under a nitrogen atmosphere. Raise the temperature
After reacting at 180 ° C for 1 hour, the temperature was raised to 200 ° C after 30 minutes.
After another 30 minutes, the reaction temperature was raised to 215 ° C, and the pressure was gradually reduced.
In 0 minutes, the degree of vacuum reached 0.1 mmHg. Thereafter, the reaction was continued for another 5 hours. The resulting polymer is white, Mn 64,900, M
w 147,900 and its Mw / Mn was 2.28. Its melting temperature is 114.9 ℃, its 2% weight loss temperature is 305.6 ℃
Met. The ratio of batyl alcohol contained in the polymer is 1.0 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer. When the mechanical strength was measured, the elastic modulus was 251 MPa, and the upper yield point stress was 24.2 MPa.
MPa, rupture stress 53.4 MPa, and elongation at break 744%. Comparative Example 1 26.32 g (0.180 mol) of dimethyl succinate, 16.83 g (0.187 mol) of 1,4-butanediol, and butyl succinate (3-87%) were placed in a glass reactor having a capacity of 100 ml with stirring blades.
Octadecyl-1,2-propanediol) 0.187 g (0.541
Mmol), titanium tetraisopropoxide 20 μl (0.1
Mmol), and the reaction was started at 160 ° C. under a nitrogen atmosphere to elute methanol. 1 hour after reaction temperature 180
℃ and heated. After another 30 minutes, the temperature was raised to 200 ° C. 3 more
After 0 minute, the reaction temperature was raised to 215 ° C., the pressure was gradually reduced, and the vacuum reached 0.1 mmHg in 30 minutes. Thereafter, the reaction was continued for another 3 hours. The polymer obtained is light brown, Mn 68,900, Mw 113,
It had a Mw / Mn of 1.65. The ratio of batyl alcohol contained in the polymer is 0.3 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer. When the mechanical strength was measured, the elastic modulus was 277 MPa, the upper yield point stress was 24.7 MPa, the breaking point stress was 40.3 MPa,
The elongation at break was 470%. Example 2 21.2 g (0.180 mol) of succinic acid and 16.4 g of 1,4-butanediol were placed in a glass reactor having an internal volume of 100 ml with stirring blades.
(0.182 mol), 1.25 g (3.62 mmol) of batyl alcohol, 20 μl (0.1 mmol) of titanium tetraisopropoxide, 6.9 mg (0.040 mmol) of magnesium phosphate trihydrate, and reacted at 160 ° C. for 30 minutes under a nitrogen atmosphere. did.
The temperature was gradually raised to 230 ° C., and the reaction was performed for 2 hours. Thereafter, the pressure was gradually reduced, and the pressure reached 0.1 mmHg in 30 minutes. Thereafter, the reaction was continued for another 3 hours. The resulting polymer is white, M
It had n 107,000 and Mw 215,000, and its Mw / Mn was 2.01. Its melting temperature was 112.1 ° C and its 2% weight loss temperature was 308.1 ° C. The ratio of batyl alcohol contained in the polymer is 2.0 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer.
When the mechanical strength was measured, the elastic modulus was 221.7 MPa,
Upper yield point stress 23.5MPa, breaking stress 47.0MPa, breaking elongation 72
7%. Example 3 21.3 g (0.180 mol) of succinic acid and 16.0 g of 1,4-butanediol were placed in a glass reactor having an inner volume of 100 ml with stirring blades.
(0.177 mol), 3.15 g (9.14 mmol) of batyl alcohol, 20 μl (0.1 mmol) of titanium tetraisopropoxide, 6.5 mg (0.037 mmol) of magnesium phosphate trihydrate, and reacted at 160 ° C. for 30 minutes under a nitrogen atmosphere. did.
The temperature was gradually raised to 230 ° C., and the reaction was performed for 2 hours. Thereafter, the pressure was gradually reduced, and the pressure reached 0.1 mmHg in 30 minutes. Thereafter, the reaction was continued for another 5 hours. The resulting polymer is white, M
n 87,700, Mw 184,000, and its Mw / Mn was 2.09. Its melting temperature was 109.5 ° C. and its 2% weight loss temperature was 311.8 ° C. The ratio of batyl alcohol contained in the polymer is 5.1 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer.
When the mechanical strength was measured, the elastic modulus was 177.7 MPa,
Upper yield point stress 19.3MPa, breaking stress 45.6MPa, breaking elongation 92
0%. Example 4 A succinic acid (21.3 g, 0.180 mol) and 1,4-butanediol (16.0 g) were placed in a 100-ml glass reactor having stirring blades.
(0.177 mol), 3.15 g of 3-methyl-1,2-propanediol
(9.0 mmol), titanium tetraisopropoxide 20 μl
(0.1 mmol), 4.6 mg of magnesium phosphate trihydrate
(0.026 mmol) at 30 ° C under nitrogen atmosphere.
Minutes. The temperature was gradually raised to 215 ° C., and the reaction was performed for 1 hour.
Thereafter, the pressure was gradually reduced, and the pressure reached 0.1 mmHg in 30 minutes. Thereafter, the reaction was continued for another 7.3 hours. The resulting polymer is white and has Mn 81,700, Mw 153,000, its Mw /
Mn was 1.88. Its melting temperature was 108.4 ° C and its 2% weight loss temperature was 312.9 ° C. The ratio of batyl alcohol contained in the polymer is 5.0 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer. Also, when the mechanical strength was measured,
Elastic modulus 319.5MPa, upper yield point stress 30.7MPa, rupture stress 58.3M
Pa and elongation at break were 696%. Example 5 19.2 g (0.192 mol) of succinic anhydride and 0.62 of butyl alcohol were placed in a glass reactor having a capacity of 100 ml with stirring blades.
g (1.81 mmol) was heated to 130 ° C. under a nitrogen atmosphere, and 20 μl (0.1 mmol) of titanium tetraisopropoxide was added. After raising the temperature to 160 ° C and reacting for 1.5 hours,
Add 17.0 g (0.189 mol) of butanediol and add 160 ° C
It reacted for 1.5 hours. The temperature was gradually raised to 215 ° C., and then the pressure was gradually reduced, and the reaction was further continued at a degree of vacuum of 0.1 mmHg for 6.5 hours. The resulting polymer is white, Mn 86,600, Mw 150,000
And its Mw / Mn was 1.72. Its melting temperature was 110.1 ° C and its 2% weight loss temperature was 317.7 ° C. The proportion of batyl alcohol contained in the polymer is 100% of the aliphatic dicarboxylic acid component contained in the polymer.
The ratio is 0.94 mole per mole. Also, when the mechanical strength was measured, the elastic modulus was 232.0MPa, the upper yield point stress was 25.6MPa.
a, the breaking stress was 58.0 MPa, and the elongation at break was 787%. The high molecular weight aliphatic polyester produced according to the present invention has a copolymerized structure with 3-alkoxy-1,2-propanediol, and a small amount of 3-alkoxy-1,2-propanediol. The mechanical strength such as elongation at break can be greatly improved by the addition of. Further, in this production method, a large amount of 3-alkoxy-1,2-propanediol can be copolymerized without lowering the elongation at break as compared with the conventional production method. Moreover, the high molecular weight aliphatic polyester has biodegradability based on the aliphatic ester bond.

────────────────────────────────────────────────── (5) References JP-A-2001-64370 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (1)

(57) [Claims] [Claim 1] The following general formula (1) (Wherein, R ¹ represents a divalent aliphatic group having 2 to 12 carbon atoms)
Or an aliphatic dicarboxylic acid represented by the following general formula (2): (Wherein, R ¹ is the same as described above) and an aliphatic dicarboxylic anhydride or a mixture thereof, and HO-R ² -OH (3) represented by the following general formula (3): R ² represents a divalent aliphatic group having 2 to 12 carbon atoms)
And an aliphatic glycol represented by the following general formula (4): (Wherein, R ³ represents an aliphatic group having 1 to 18 carbon atoms) and a condensation reaction with 3-alkoxy-1,2-propanediol represented by the following general formula (5) An ester moiety A and an ester moiety B represented by the following general formula (6)
A process for producing a biodegradable high molecular weight aliphatic polyester having the formula: Embedded image (In the formula, R ¹ and R ² are the same as above. P represents the mole fraction of the ester moiety (A) represented by the general formula (5).) (In the formula, R ¹ and R ³ are the same as described above. R represents the mole fraction of the ester moiety (B) represented by the general formula (6).)