JPH0570574A - Production of aliphatic polyester - Google Patents

Abstract

PURPOSE:To produce an aliph. polyester having a high m.p. and strengths sufficient for practical use with an extremely small amt. of a catalyst used. CONSTITUTION:An aliph. polyester having a softening point of at least 70 deg.C and a number-average mol. wt. of at leant 10,000 is produced by esterifying 1,4-butanediol with a dicarboxyic acid component consisting of 50-100mol% succinic acid and 50-0mol% dicarboxylic acid selected from the group consisting of adipic, sebacic, and lauric acids and eliminating the glycol maleules in the presence thence of 0.0001-0.1 pt.wt. (based on 100 pts.wt. the polyester) titanium (oxy) acetylacetonate as a catalyst.

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 having a practically sufficient strength, a high melting point, and a very small amount of catalyst.

[0002]

BACKGROUND OF THE INVENTION Aliphatic saturated polyesters have a low melting point, and even if they have a number average molecular weight of 10,000 or more in a high molecular weight region, polyesters containing a saturated aromatic structure, such as polyethylene terephthalate, are practically sufficient. Until now, it has been considered impractical because it does not exhibit such mechanical properties. In fact, even if the film has a film-forming property, the produced film did not reach the performance required for the tear strength and the tensile strength and was not practically usable. Among them, the aliphatic polyester containing 1,4-butanediol as a glycol component has relatively high strength, and particularly the aliphatic polyester using succinic acid as a dicarboxylic acid has a high melting point of 110 to 115 ° C. Target. However, when the number average molecular weight is not sufficiently high, a slightly hard and fragile tendency is also recognized, and in the case of imparting flexibility, it is desirable to use a combination of dicarboxylic acids having many methylene bonds such as adipic acid, sebacic acid, and dodecanoic acid. .. Conventionally, in order to produce a high-molecular-weight polyester having a number-average molecular weight of 10,000 or more, for example, in the case of polyethylene terephthalate, per 1 mol of terephthalic acid
Organic and inorganic compounds of 0.001 to 0.1 mol% of heavy metals such as antimony, zinc, titanium, lead, manganese, germanium and zirconium are used as catalysts for the deglycolization reaction. It is also known to use a lithium compound in combination. Generally, the amount of the catalyst is 0.1 to 1 in terms of 100 parts by weight of polyethylene terephthalate.
It has been considered to be difficult to obtain a high molecular weight polyester with a catalyst amount of less than this. However, in practical use, if it is handled or discharged as garbage,
From the viewpoint of safety, it is desirable to use the catalyst in a small amount as much as possible. The present invention solves the above-mentioned conventional problems, has a practically sufficient strength and a high melting point, and above all, a method for producing an aliphatic polyester which can use a very small amount of a catalyst. It is intended to be provided.

[0003]

As a result of earnest studies, the present inventors were able to solve the above problems. That is, the present invention comprises 1,4-butanediol and 50-100
Mol% succinic acid and 50-0 mol% adipic acid,
When at least one dicarboxylic acid selected from sebacic acid and dodecanoic acid is esterified, and then deglycolized, an aliphatic polyester having a melting point of 70 ° C. or higher and a number average molecular weight of 10,000 or higher is produced. As a catalyst, 0.0001 ~
The present invention provides a method for producing an aliphatic polyester, which comprises using 0.1 part by weight of titanium (oxy) acetylacetonate.

The present invention will be described in more detail below.
Unless otherwise specified, the number average molecular weight is simply referred to as the molecular weight. The present inventors have found that 1,4-butanediol and succinic acid,
In addition, when adipic acid, sebacic acid or dodecanoic acid is used in combination, if necessary, when synthesizing an aliphatic polyester having a molecular weight of 10,000 or more, a catalyst effective as small as possible was examined. It was found that even a small amount of 0.1 parts by weight or less with respect to parts by weight was effective, and the present invention could be completed.

The production of a saturated polyester composed of 1,4-butanediol and succinic acid, and optionally adipic acid, sebacic acid or dodecanoic acid can be carried out by a known technique. The esterification reaction and deglycolization reaction conditions for producing this saturated polyester can be set to appropriate conditions conventionally used, and are not particularly limited. The amount of 1,4-butanediol used is substantially equimolar to 100 mol% of succinic acid or a mixed acid of succinic acid and at least one dicarboxylic acid selected from adipic acid, sebacic acid and dodecanoic acid. But
Generally, there is a distillate during esterification, so 5-20
Use in molar excess is performed. As the acid used in combination with 1,4-butanediol, only succinic acid can be used. Apart from this, a suitable mixing ratio of each component in succinic acid and at least one dicarboxylic acid (including acid anhydride) -based mixed acid selected from adipic acid, sebacic acid and dodecanoic acid is usually 50 succinic acid
The amount of the dicarboxylic acid such as adipic acid is 50 mol% or less, preferably 40 mol% or less. When the amount of the dicarboxylic acid used in combination with succinic acid exceeds 50 mol%, the melting point of the obtained saturated polyester becomes 70 ° C. or lower, which is not preferable in practice.

The catalyst used in the present invention has a structural formula

[0007]

[Chemical 1]

It is titanium (oxy) acetylacetonate represented by: The amount of this catalyst to be used is 0.0001 to 0.001 with respect to 100 parts by weight of a saturated polyester obtained by reacting 1,4-butanediol with succinic acid, and optionally with adipic acid, sebacic acid or dodecanoic acid. 1 part by weight, preferably 0.001 part by weight to 0.05 part by weight. If the amount used is less than 0.0001 parts by weight, the action of the catalyst becomes weak,
It becomes difficult to obtain the target molecular weight. Also, 0.
Even if the amount used exceeds 1 part by weight, the action does not change significantly. With respect to catalysts other than titanium compounds, no catalyst capable of synthesizing a high molecular weight polyester was found within the above range of use. The aliphatic polyester produced as described above has practically sufficient strength and flexibility, and also has a high melting point, so various molding methods can be used according to various applications. For example, when forming a film using this, a known film forming method can be used,
There is no particular limitation. Further, at the time of molding, various molding aids such as fillers (inorganic or organic), colorants, reinforcing materials, waxes, thermoplastic polymers, oligomers and the like can be used in combination depending on the application.

[0009]

EXAMPLES The present invention will be described below with reference to examples. Example 1 A 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube was charged with 1,4-butanediol 2
Charge 50 g, succinic acid 290 g, and titanium (oxy) acetylacetonate 0.05 g (about 0.01 phr).
After esterification in a nitrogen stream at 10 to 220 ° C to an acid value of 9.6, the pressure was finally reduced to 0.5 Torr, and
Deglycol reaction at 5 ~ 220 ℃ for 8 hours, molecular weight
16,100 saturated polyester (A) (Shodex GPC SYSTEM
-11, the result of GPC analysis using Showa Denko) was obtained. When cooled to room temperature, it became white waxy crystals and had a melting point of 113 ° C. Separately, when the reaction was carried out under the same conditions without using titanium (oxy) acetylacetonate, the obtained aliphatic polyester had a molecular weight of 5,800, showing a large difference.

Example 2 In a 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube, 1,4-butanediol 2 was added.
50g, succinic acid 232g, adipic acid 58g, titanium (oxy) acetylacetonate 0.02g (about 0.004ph
r) was charged, and the acid value was adjusted to 6.7 by esterification in a nitrogen stream at 210 to 215 ° C, and finally the pressure was reduced to 0.5 Torr and deglycollation was performed at 210 to 215 ° C for 12 hours to obtain a molecular weight. 16,900 saturated polyesters (B) were obtained. When cooled to room temperature, it became a white wax with a slight tan color. The melting point was about 95 ° C. Separately, when the reaction was performed under the same conditions without using titanium (oxy) acetylacetonate, the obtained aliphatic polyester had a molecular weight of 6,600, showing a large difference.

Example 3 A 4-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube was charged with 1,4-butanediol 4
95 g, succinic acid 406 g, dotecanoic acid 339 g, titanium (oxy) acetylacetonate 0.025 g (about 0.002 ph
r) was charged, and the acid value was adjusted to 7.9 by esterification in a nitrogen stream at 210 to 215 ° C., and finally the pressure was reduced to 0.5 Torr and a deglycolization reaction was performed at 210 to 215 ° C. for 10 hours. .. The molecular weight of the obtained saturated polyester (C) is
The melting point was 15,900 and the melting point was about 80 ° C. When cooled to room temperature, it became a white wax.

[0012]

The present invention provides a process for producing an aliphatic polyester which has practically sufficient strength, has a high melting point, and can use a very small amount of catalyst.

Claims (1)

[Claims] 1. 1,4-butanediol and 50 to 100
Mol% succinic acid and 50-0 mol% adipic acid,
When at least one dicarboxylic acid selected from sebacic acid and dodecanoic acid is esterified and then deglycolized to produce an aliphatic polyester having a melting point of 70 ° C. or more and a number average molecular weight of 10,000 or more, 100 parts by weight of the aliphatic polyester is used. As a catalyst for
A method for producing an aliphatic polyester, which comprises using 0.0001 to 0.1 part by weight of titanium (oxy) acetylacetonate.