JP3201788B2 - Method for producing aliphatic polyester - Google Patents

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 which has sufficient strength for practical use, has a high melting point, uses a very small amount of catalyst, and can be formed into a film or the like. .

[0002]

BACKGROUND OF THE INVENTION Aliphatic saturated polyesters are:
In general, the melting point is low, most of which are 70 ° C. or less, and even if the number average molecular weight is in the high molecular range of 10,000 or more, a polyester containing a saturated aromatic structure, such as polyethylene terephthalate, has sufficient mechanical properties for practical use. It has not been practical until now because it does not show physical properties. In fact, even when the film has a film forming property, the produced film has low tear strength and tensile strength and is not practical. Of these aliphatic polyesters, exceptionally, aliphatic polyesters synthesized using 1,4-butanediol as a glycol component and succinic acid as a dicarboxylic acid component are almost all aliphatic polyesters.
Compared to showing only a melting point of 0 ° C. or less, 110 to 11
It has been found that a film having a high melting point of 5 ° C. and exhibiting considerable strength is possible. Conventionally, it is known to use an organic compound of titanium as an esterification catalyst. 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 bis (β-hydroxyethyl) terephthalate, 0.05 mol% of titanium and at least 0.01 mol% or more per mol of terephthalic acid are used. Organic compounds are used. In terms of the amount of the catalyst used, as much as 0.5 to 2 parts by weight of an organic compound of titanium per 100 parts by weight of the terephthalate in terms of parts by weight is used as the catalyst for the glycol removal reaction. Organic compounds of titanium are said to be less toxic than other heavy metals such as lead, tin, antimony, cadmium, chromium, etc. From the point of view, it is desired to use as little as possible. The present invention solves the conventional problems as described above, and provides a method for producing an aliphatic polyester having sufficient strength for practical use, a high melting point, and a very small amount of catalyst to be used. It is intended to do so.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have conducted extensive studies on dicarboxylic acids, which are constituent materials of polyesters, and glycols. As a result, ethylene glycol and the above dicarboxylic acids (or acid anhydrides thereof) were used as glycol components. ), The use of titanium oxyacetylacetonate as a catalyst in the esterification and deglycolization reaction as a raw material, has a practically sufficient strength and a high melting point even if the amount of the catalyst is small. The inventors have found that polyester can be obtained, and have completed the present invention. That is, the present invention relates to ethylene glycol

[0004]

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(Where n is an integer of 2 to 12) is subjected to an esterification reaction with a dicarboxylic acid or an acid anhydride thereof, followed by a deglycol reaction to produce an aliphatic polyester. As a catalyst for the glycol reaction
An aliphatic polyester having a melting point of 60 ° C. or more and a number average molecular weight of 10,000 or more by using 0.0001 to 0.01 parts by weight (based on 100 parts by weight of the produced polyester) of titanium oxyacetylacetonate; Is provided. Thus, the present invention is characterized in that it has been found that even when the organic compound of titanium is used in an amount of 0.01 part by weight or less, it is useful as a reaction catalyst for ethylene glycol and an aliphatic dicarboxylic acid. Together with the inertness of organic compounds against living organisms, it is useful for further improving the safety of the produced polyester on the human body.

Hereinafter, the present invention will be described in more detail.
Unless otherwise specified, the number average molecular weight is simply expressed as molecular weight.

The production of a saturated polyester using ethylene glycol and the above dicarboxylic acid can be carried out by a known technique. The conditions for the esterification reaction and the deglycolization reaction when producing this saturated polyester can be set to appropriate conditions conventionally used, and are not particularly limited.

The amount of the glycol component used in the present invention is equimolar to the dicarboxylic acid component, but is generally used in a slightly excessive amount due to distillation during esterification.

The dicarboxylic acid used in combination with ethylene glycol has the general formula

[0010]

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Wherein n is an integer of 2 to 12 or an acid anhydride thereof, such as succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, etc. Succinic acid and also mixed acids of succinic acid with other dicarboxylic acids such as adipic acid, suberic acid, sebacic acid and dodecanoic acid are preferred. When the mixed acid is used, for example, a suitable mixing ratio of each component of a two-component system or more composed of succinic acid and another dicarboxylic acid is usually 50 mol% or more, preferably 6 mol% or more of succinic acid.
The content of dicarboxylic acid other than succinic acid is 0 mol% or more and 50 mol% or less, preferably 40 mol% or less.

The catalyst used in the present invention is titanium oxyacetylacetonate. Titanium oxyacetylacetonate has the general formula

[0013]

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[0014] The amount of the catalyst used is 0.0001 parts by weight based on 100 parts by weight of a saturated polyester obtained by reacting ethylene glycol and dicarboxylic acid.
To 0.01 parts by weight, preferably 0.001 parts to 0.01 parts by weight. If the amount is less than 0.0001 part by weight, the action of the catalyst becomes weak, and it becomes difficult to obtain a target molecular weight. Further, even if the amount is more than 0.01 part by weight, the effect is not largely changed, and only the catalyst residue increases, which is not preferable. The deglycolization catalyst may be added from the beginning of the esterification reaction between glycol and dicarboxylic acid, or may be added after the esterification reaction is completed. The aliphatic polyester produced as described above has practically sufficient strength and flexibility,
Furthermore, since the melting point is high, various molding methods can be used according to various applications. For example, when a film is formed using this, a known film forming method can be used, and there is no particular limitation. Further, at the time of molding, various molding auxiliaries, for example, fillers (inorganic and organic), coloring agents, reinforcing materials, waxes, thermoplastic polymers, oligomers, and the like can be used in combination depending on the use.

[0015]

The present invention will be described below by way of examples.

Example 1 Ethylene glycol 1 was placed in a 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube.
40 g, 176 g of succinic acid, 58 g of adipic acid and 0.015 g of titanium oxyacetylacetonate were charged and esterified at 195 to 205 ° C. in a nitrogen stream to obtain an acid value of 7.
After that, the pressure was finally reduced to 0.5 Torr,
Deglycolate at ~ 220 ° C for 10 hours, molecular weight 12,1
A saturated polyester (C) of 00 was obtained. Upon cooling to room temperature, a pale yellow-brown wax was formed. Melting point is about 75
° C. Apart from this, when reacted under the same conditions without using titanium oxyacetylacetonate,
The molecular weight of the obtained aliphatic polyester (D) was 5,300, and a large difference was recognized.

[0017]

[0018]

According to the present invention, there is provided a process for producing an aliphatic polyester which can be molded into a film or the like, which has sufficient strength for practical use, has a high melting point, and can use a very small amount of a catalyst. Provided.

Claims (1)

(57) [Claims] 1. An ethylene glycol and a compound represented by the general formula: (Where n is an integer of 2 to 12) is subjected to an esterification reaction with a dicarboxylic acid or an acid anhydride thereof, followed by a deglycolization reaction to produce an aliphatic polyester. By using 0.0001 to 0.01 parts by weight (based on 100 parts by weight of the produced polyester) of titanium oxyacetylacetonate represented by the following formula as a catalyst, it is possible to obtain an aliphatic polyester having a melting point of 60 ° C. or more and a number average molecular weight of 10,000 or more. A method for producing an aliphatic polyester. Embedded image