JP2001081165A - Method for producing biodegradable polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new biodegradable plastic by effectively utilizing waste PET bottles, and to provide a method for producing the same plastic. SOLUTION: This method for producing a biodegradable polyester where the content of terephthalic acid component is 5-50 wt.% based on the total content of the terephthalic acid component and succinic acid component comprises the following processes: a waste PET bottle chip-liquefying process for obtaining a liquid product by reacting waste PET bottle chips with 1,4- butanediol at >=140 deg.C in the presence of a transesterification catalyst; and a polyester-producing process for producing a polyester made from terephthalic acid component, succinic acid component and 1,4-butanediol component by adding dimethyl succinate to the above liquid product to react them at 100-140 deg.C while discharging methanol as a by-product and then heating the reaction product at >=190 deg.C to perform further reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable polyester and a method for producing the same.

[0002]

2. Description of the Related Art The disposal of plastic waste has become a serious social problem, and the recycling of plastics is becoming increasingly important. A typical example of plastics that are currently being recycled is PET bottles, but in the case of PET bottles, the problem that the amount of waste plastic generated exceeds the demand for recycled products has arisen. There is a need for even more effective usage. Also, if a biodegradable polymer that can be decomposed by microorganisms in the soil can be produced using waste PET bottles as a raw material, the environmental burden of landfill processing after reuse will be reduced, and it will be necessary to solve environmental problems. However, such a substance or technique has not been known.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel biodegradable plastic by effectively using a waste PET bottle and a method for producing the same.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, a terephthalic acid component, a succinic acid component, and a 1,4-butanediol component are included, and the ratio of the terephthalic acid component is based on the total amount of the terephthalic acid component and the succinic acid component. , 5 to 50% by weight. Further, according to the present invention, a terephthalic acid component, a succinic acid component, a 6-hexanolactone component, and a 1,4-butanediol component, and the ratio of the terephthalic acid component is
A biodegradable polyester is provided, which is 5 to 50% by weight based on the total amount of the terephthalic acid component, the succinic acid component and the 6-hexanolactone component.
Further, according to the present invention, waste plastic bottle chips and 1,
4-butanediol is converted to 1 in the presence of a transesterification catalyst.
A liquefaction process of waste PET bottle chips that is reacted at a temperature of 40 ° C. or more to obtain a liquid product, and dimethyl succinate is added to the liquid product, and the reaction is performed at 100 ° C. to 140 ° C. while flowing out methanol as a by-product. And heating the mixture to a temperature of 190 ° C. or higher to further react to produce a polyester comprising a terephthalic acid component, a succinic acid component, and a 1,4-butanediol component. The ratio of the terephthalic acid component is based on the total amount of the terephthalic acid component and the succinic acid component.
A method for producing a biodegradable polyester, characterized in that the amount is 5 to 50% by weight. Furthermore, according to the present invention, dimethyl terephthalate, dimethyl succinate and 1,4-butanediol are reacted at 100 to 140 ° C. in the presence of a transesterification catalyst at a temperature of 190 to 140 ° C. while allowing by-product methanol to flow out. The reaction was further performed by heating to the above temperature, and the terephthalic acid component, the succinic acid component, and 1,4-
Producing a polyester comprising a butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to 50% by weight based on the total amount of the terephthalic acid component and the succinic acid component. A method for producing a biodegradable polyester is provided. Furthermore, according to the present invention, dimethyl terephthalate, dimethyl succinate, 1,4-butanediol and 6-hexanolactone can be converted to 100-140 in the presence of a transesterification catalyst.
After reacting while flowing methanol by-produced at a temperature of 190 ° C., the reaction is further carried out by heating to a temperature of 190 ° C. or higher, and a terephthalic acid component, a succinic acid component, a 6-hexanolactone component and 1,4-butane Forming a polyester comprising a diol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to 50 with respect to the total amount of the terephthalic acid component, the succinic acid component, and the 6-hexanolactone component. A method for producing a biodegradable polyester is provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The biodegradable polyester of the present invention comprises (i) a terephthalic acid component, a succinic acid component, and 1,4-
Contains butanediol as an essential component or (ii)
It contains a terephthalic acid component, a succinic acid component, and a 6-hexanolactone component as essential components. In this case, the terephthalic acid component is preferably derived from a waste plastic bottle, but may of course be derived from another product, and at least a part thereof is commercially available terephthalic acid or terephthalic acid. It may be derived from dimethyl. The number average molecular weight of the biodegradable polyester according to the present invention is 40,000 or more, preferably 50,000 or more, and the upper limit is not particularly limited, but is usually about 60,000.

In the biodegradable polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component according to the present invention, the proportion of the terephthalic acid component is as follows:
5 to the total amount of the terephthalic acid component and the succinic acid component
It is 40 mol%, preferably 10 to 37 mol%. When the proportion of the terephthalic acid component is larger than the above range, the biodegradability of the obtained polyester deteriorates, which is not preferable. The ratio of 1,4-butanediol is 0.9 per mole of the total amount of the terephthalic acid component and the succinic acid component.
To 1.1 mol, preferably 0.95 to 1.1 mol.

[0007] In the biodegradable polyester comprising a terephthalic acid component, a succinic acid component, a 6-hexanolactone component and a 1,4-butanediol component according to the present invention, the proportion of the terephthalic acid component is determined by comparing the terephthalic acid component with the succinic acid component. It is 5 to 40 mol%, preferably 10 to 37 mol%, based on the total amount of the component and the 6-hexanolactone component. The ratio of the succinic acid component is 40 to 90 mol%, preferably 50 to 80 mol%. The proportion of the 6-hexanolactone component is 5 to 20 mol%, preferably 10 to 15 mol%. The ratio of the 1,4-butanediol component is 0.8 to 1 mol, preferably 0.85 to 0.9 mol, per 1 mol of the total amount of the terephthalic acid component, the succinic acid component and the 6-hexanolactone component. Is the ratio of

The biodegradable polyester of the present invention may contain other polymerizable components, such as other dicarboxylic acid components, oxycarboxylic acid components, and diol components, if necessary, without impairing the object of the present invention. It can be contained in the range.

The biodegradable polyester of the present invention can be produced using waste PET bottle chips as a raw material. According to this method, first, a plastic bottle chip is reacted with 1,4-butanediol in the presence of a transesterification catalyst to obtain a liquefied product. The reaction temperature in this case is 140 ° C. or higher, usually 160 to 210 ° C., preferably 180 ° C.
~ 200 ° C. The smaller the size of the PET bottle chip is, the more preferable it is. However, in general, it is preferable that the vertical and horizontal lengths are each 10 mm or less. As the transesterification catalyst, conventionally known various catalysts can be used. For example, titanium acetylacetonate and the like are preferably used.

[0010] The liquefaction reaction of the waste PET bottle chips is carried out by filling the PET bottle chips, 1,4-butanediol and a transesterification catalyst in a closed container, and heating. By this reaction, the pet (polyethylene terephthalate) constituting the chip is 1,4
Reacting with butanediol to oligomerize to obtain a liquid product;

Next, (i) dimethyl succinate or (ii) dimethyl succinate and 6-hexanolactone are added to the liquid product obtained as described above, and if necessary, dimethyl terephthalate is added. , In the presence of a transesterification catalyst,
The reaction is carried out by heating under stirring. The reaction in this case is first
This is carried out at a temperature of 00 to 140 ° C. while flowing out methanol as a by-product. When the flow of methanol stops, the next 190
° C or higher, usually 190-210 ° C, preferably 1
The polycondensation reaction is completed by heating to a temperature of 90-200 ° C. Agitation in this reaction can be performed by bubbling nitrogen gas from the bottom of the reaction vessel.

According to another method for producing the biodegradable polyester of the present invention, (i) dimethyl terephthalate, dimethyl succinate and 1,4-butanediol or (ii) dimethyl terephthalate, dimethyl succinate , 6-
Hexanolactone and 1,4-butanediol are converted to 100 to 1 in the presence of a transesterification catalyst and with stirring.
The reaction is carried out at a temperature of 40 ° C. while allowing the by-product methanol to flow out. When the flow of methanol stops, 190 ° C or higher,
Usually 190-210 ° C, preferably 190-200 ° C
The reaction (polycondensation reaction) is completed at a temperature of.

[0013]

Next, the present invention will be described in detail with reference to examples.

EXAMPLE 1 (Reactor) A stainless steel autoclave having an internal volume of about 300 cc, which was connected to a stainless steel pipe through a gas inlet of a stainless steel autoclave so that gas could be bubbled from the bottom of the autoclave, was used. (Synthesis of Polymer A) 2.23 g (0.0116 mol) of PET bottle chips washed with water and dried, 6.96 g (0.0772 mol) of 1,4-butanediol, and 2.5 mg of Ti acetylacetonate as a catalyst (0.009
5 mmol) was charged into the above-mentioned autoclave, and the autoclave valve was closed, and the mixture was stirred for 19 hours while being sealed.
Heat to 0 ° C. At this time, the pressure rises to a maximum of 0.08 MPa, and it is detected by a change in the stirring sound that the PET bottle chip has completely dissolved and the solid matter has disappeared. At this time, the PET bottle chips are decomposed by 1,4-butanediol to become oligomers and dissolved in the reaction solution. next,
The autoclave was cooled to room temperature, and 9.59 g (0.0656 mol) of dimethyl succinate was added to the obtained liquid product.
After charging, the outlet valve of the autoclave was opened, nitrogen was bubbled from the bottom of the vessel at a rate of 50 ml / min, and the mixture was stirred at 100 ° C. for 2 hours.
The reaction is carried out at 0 ° C. for 2 hours with the effluent of methanol.
The effluent methanol is collected in an ice-cooled trap. Next, the temperature was raised to 190 ° C., and a polycondensation reaction was performed for 7 hours while bubbling nitrogen at a rate of 0.9 l / min. The obtained copolycondensate (polymer A) contained a terephthalic acid component, had a softening point of 91.6 ° C, a flow starting point of 99.1 ° C, and a number average molecular weight of 48,000. As a result of a biodegradability test by embedding in soil for 4 weeks, the degradation rate was 28.7%.
The degradation rate of the polybutylene succinate homopolymer carried out in parallel is 49.6% and therefore the biodegradability based on the homopolymer is 57.9%. The biodegradation rate of the PET bottle chips performed in parallel was 0%. The polymer A contains 8 mol% of a terephthalic acid component, 42 mol% of a succinic acid component, and 47 mol of a 1,4-butanediol component.
It was confirmed to be composed of mol%.

Example 2 (Reactor) The same apparatus as described in Example 1 was used. (Synthesis of Polymer B) 2.43 g of dimethyl terephthalate
(0.0125 mol), 6-hexanolactone 1.43
g (0.0125 mol), 14.6 g of dimethyl succinate
(0.100 mol), 1,4 butanediol 10.5
g (0.117 mol) and 3.0 mg (0.011 mmol) of Ti acetylacetonate as a catalyst were charged into the above autoclave, the outlet valve of the autoclave was opened, and nitrogen was bubbled from the bottom of the autoclave at a rate of 50 ml / min. The reaction is carried out at 100 ° C. for 2 hours while stirring and then methanol is allowed to flow out at 140 ° C. for 2 hours while increasing the temperature. The effluent methanol is collected in an ice-cooled trap. Next, the temperature was increased to 190 ° C., and nitrogen was added at 0.5 l /
The polycondensation reaction was performed for 7 hours while bubbling at a speed of min. The obtained copolycondensate (polymer B) contains a terephthalic acid component and a hexanolactone component, and has a softening point of 9%.
4.2 ° C., flow starting point 98.6 ° C., melting point 94.0 ° C., glass transition point −37.9 ° C., and number average molecular weight 44,000. As a result of biodegradability test by embedding in soil for 4 weeks,
The decomposition rate was 44.4%. The degradation rate of the polybutylene succinate homopolymer performed in parallel was 40.7%, and therefore the biodegradability based on the homopolymer was 10%.
9%. The polymer B contains 5 mol% of a terephthalic acid component, 42 mol% of a succinic acid component, 5 mol% of a 6-hexanolactone component, and 47 mol% of a 1,4-butanediol component.
It was confirmed to be composed of

Example 3 (Reactor) The same apparatus as described in Example 1 was used. (Synthesis of Polymer C) 2.43 g of dimethyl terephthalate
(0.0125 mol), 16.5 g of dimethyl succinate
(0.113 mol), 11.7 1,4-butanediol
g (0.130 mol) and 0.9 mg (0.003 mmol) of Ti acetylacetonate as a catalyst were charged into the above autoclave, the outlet valve of the autoclave was opened, and nitrogen was bubbled from the bottom of the autoclave at a rate of 50 ml / min. The reaction is carried out at 100 ° C. for 2 hours while stirring and then methanol is allowed to flow out at 140 ° C. for 2 hours while increasing the temperature. The effluent methanol is collected in an ice-cooled trap. Next, the temperature was increased to 190 ° C. and nitrogen was added at 0.5 l / m 2.
The polycondensation reaction was carried out for 7 hours while bubbling at a rate of in. The obtained copolycondensate (polymer C) contains a terephthalic acid component, has a softening point of 103.6 ° C. and a flow starting point of 10
8.5 ° C., melting point 106.3 ° C., glass transition point −18.9
° C and the number average molecular weight was 36,000. As a result of a biodegradability test by embedding in soil for 4 weeks, the degradation rate was 56.2%. The degradation rate of the polybutylene succinate homopolymer carried out in parallel is 63.5% and therefore the biodegradability based on the homopolymer is 89%. The polymer C contains 5 mol% of a terephthalic acid component and 44 parts of a succinic acid component.
It was confirmed that the composition consisted of 50% by mole and 1,4-butanediol component.

Example 4 (Reactor) The same apparatus as described in Example 1 was used. (Synthesis of Polymer D) 2.23 g (0.0116 mol) of PET bottle chips washed with water and dried, 6.96 g (0.0772 mol) of 1,4-butanediol, and 2.6 mg of Ti acetylacetonate as a catalyst (0.009
9 mmol) was charged into the above-mentioned autoclave, and the autoclave valve was closed.
Heat to 0 ° C. At this time, the pressure rises to a maximum of 0.08 MPa, and it is detected by a change in the stirring sound that the PET bottle chip has completely dissolved and the solid matter has disappeared. At this time, the PET bottle chips are decomposed by 1,4-butanediol to become oligomers and dissolved in the reaction solution. Next, the autoclave was cooled to room temperature, and after charging 3.00 g (0.0154 mol) of dimethyl terephthalate and 7.33 g (0.0502 mol) of dimethyl succinate, the outlet valve of the autoclave was opened, and nitrogen was passed through the bottom of the autoclave. 50ml
The reaction is carried out while bubbling and stirring at a rate of / min at 100 ° C. for 2 hours, then increasing the temperature and flowing methanol at 140 ° C. for 2 hours. The effluent methanol is collected in an ice-cooled trap. Next, while raising the temperature to 190 ° C. and bubbling nitrogen at a rate of 0.5 l / min,
The polycondensation reaction was performed for 7 hours. The obtained copolycondensate (polymer D) contains a terephthalate component and has a softening point of 95.
The temperature was 7 ° C., the flow starting point was 109.6 ° C., and the number average molecular weight was 56,000. As a result of a biodegradability test by embedding in soil for 4 weeks, the degradation rate was 2.8%. The degradation rate of polybutylene succinate homopolymer performed in parallel was 49.6.
% And therefore the biodegradability based on the homopolymer is 5.6%. The biodegradation rate of the PET bottle chips performed in parallel was 0%. It was confirmed that the polymer D was composed of 18 mol% of a terephthalic acid component, 32 mol% of a succinic acid component, and 47 mol% of a 1,4-butanediol component.

Example 5 (Reactor) The same apparatus as described in Example 1 was used. (Synthesis of Polymer E) 1.48 g (0.00772 mol) of PET bottle chips washed with water and dried, 6.96 g (0.0772 mol) of 1,4-butanediol, and 2.5 mg of Ti acetylacetonate as a catalyst (0.00
95 mmol) into the above-mentioned autoclave, close the autoclave valve, and stir 1
Heat to 90 ° C. At this time, the pressure is up to 0.08MPa
And it is detected by the change in the stirring sound that the plastic bottle chip has completely dissolved and the solid matter has disappeared. At this time, the PET bottle chips are decomposed by 1,4-butanediol to become oligomers and dissolved in the reaction solution. The autoclave is then cooled to room temperature and dimethyl succinate 1
After charging 0.15 g (0.0695 mol), the outlet valve of the autoclave was opened, and 50 ml of nitrogen was fed from the bottom of the autoclave.
The reaction is carried out at 100 ° C. for 2 hours while bubbling and stirring at a rate of / min, and then increasing the temperature and flowing methanol at 140 ° C. for 2 hours. The effluent methanol is collected in an ice-cooled trap. Next, while raising the temperature to 190 ° C. and bubbling nitrogen at a rate of 0.5 l / min,
The polycondensation reaction was performed for 7 hours. The obtained copolycondensate (polymer E) contains a terephthalate component and has a softening point of 10
0.4 ° C, pour point 115.8 ° C, number average molecular weight 5.
It was 30,000. As a result of a biodegradability test by embedding in soil for 4 weeks, the degradation rate was 38.0%. Degradation rate of polybutylene succinate homopolymer performed in parallel was 2
0.7%, and thus the biodegradability based on the homopolymer is 184%. The biodegradation rate of the PET bottle chips performed in parallel was 0%. The polymer E
Was confirmed to be composed of 5 mol% of a terephthalic acid component, 45 mol% of a succinic acid component, and 47% of a 1,4-butanediol component.

[0019]

The polyester of the present invention has good biodegradability while containing a terephthalic acid component. About 10 to 30% of the weight of the biodegradable polymer of the present invention is a terephthalic acid component, and this component is covered by the recycled weight of waste PET bottles. It is cheaper than nate. In addition, the method for producing the polyester of the present invention is much lower in cost than the conventional production method requiring a high vacuum. Therefore, according to the present invention, a biodegradable polymer less expensive than the conventional one can be obtained. In addition, the present invention is also useful as a social demand for recycling waste plastic bottles.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 5, 2000 (2006.5.5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

1. A terephthalic acid component and the acid component 6-
It comprises a hexanolactone component and a 1,4-butanediol component, and the ratio of the terephthalic acid component is 5 to 50 with respect to the total amount of the terephthalic acid component, the succinic acid component and the 6-hexanolactone component. A biodegradable polyester characterized by weight percent.

2. A process for liquefying a waste PET bottle chip in which a waste PET bottle chip is reacted with 1,4-butanediol at a temperature of 140 ° C. or higher in the presence of a transesterification catalyst to obtain a liquid product. Dimethyl succinate is added to the liquid product and reacted at 100 ° C. to 140 ° C. while flowing out methanol as a by-product. The mixture is further heated to a temperature of 190 ° C. or higher to further react, and the terephthalic acid component and the succinic acid component are reacted. And a polyester producing step of producing a polyester comprising a 1,4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to the total amount of the terephthalic acid component and the succinic acid component. 50% by weight of the biodegradable polyester.

3. The reaction of dimethyl terephthalate, dimethyl succinate and 1,4-butanediol at 100 to 140 ° C. in the presence of a transesterification catalyst while allowing by-product methanol to flow out. Heating and further reacting to form a polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is A method for producing a biodegradable polyester, comprising 5 to 50% by weight based on the total amount of a succinic acid component and succinic acid component.

4. A reaction of dimethyl terephthalate, dimethyl succinate, 1,4-butanediol and 6-hexanolactone at 100 to 140 ° C. in the presence of a transesterification catalyst while allowing methanol by-produced to flow out. Later, 19
Heating to a temperature of 0 ° C. or higher to further react to form a polyester comprising a terephthalic acid component, a succinic acid component, a 6-hexanolactone component, and a 1,4-butanediol component. The ratio of the terephthalic acid component in the terephthalic acid component, the succinic acid component, and the 6-hexanolactone component is 5%.
50% by weight of the biodegradable polyester.

Wherein said dimethyl terephthalate, claim 3 or 4 methods is derived from waste PET bottles.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have completed the present invention. That is, according to the present invention, a terephthalic acid component, a succinic acid component, a 6-hexanolactone component, and 1,4-
A terephthalic acid component, the succinic acid component and the terephthalic acid component.
-A biodegradable polyester is provided, which is 5 to 50% by weight based on the total amount of the hexanolactone component. Further, according to the present invention, a liquefaction process for waste PET bottle chips in which a waste product is obtained by reacting waste PET bottle chips with 1,4-butanediol at a temperature of 140 ° C. or higher in the presence of a transesterification catalyst. And, after adding dimethyl succinate to the liquid product and reacting at 100 ° C. to 140 ° C. while flowing out methanol as a by-product, the mixture is further heated to a temperature of 190 ° C. or higher to further react, and the terephthalic acid component A polyester production step of producing a polyester comprising a succinic acid component and a 1,4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is based on the total amount of the terephthalic acid component and the succinic acid component. And a method for producing a biodegradable polyester, characterized in that the amount is 5 to 50% by weight. Furthermore, according to the present invention, after reacting dimethyl terephthalate, dimethyl succinate and 1,4-butanediol at 100 to 140 ° C. in the presence of a transesterification catalyst while allowing by-product methanol to flow out, 190 ° C. or more And further reacted to obtain a terephthalic acid component, a succinic acid component and 1,4
A polyester comprising a butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to 50% by weight based on the total amount of the terephthalic acid component and the succinic acid component. A method for producing a biodegradable polyester is provided. Furthermore, according to the present invention, dimethyl terephthalate, dimethyl succinate, 1,4-butanediol and 6-hexanolactone can be converted from 100 to 14 in the presence of a transesterification catalyst.
The reaction is carried out at 0 ° C. while methanol produced as a by-product is allowed to flow, and then heated to a temperature of 190 ° C. or higher to further react, and a terephthalic acid component, a succinic acid component, a 6-hexanolactone component, and 1,4- A polyester comprising a butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to 5% based on the total amount of the terephthalic acid component, the succinic acid component, and the 6-hexanolactone component. A method for producing a biodegradable polyester, wherein the method is 50% by weight.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

In the biodegradable polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component according to the present invention, the proportion of the terephthalic acid component is as follows:
5 to the total amount of the terephthalic acid component and the succinic acid component
It is 40 mol%, preferably 10 to 37 mol%. When the proportion of the terephthalic acid component is larger than the above range, the biodegradability of the obtained polyester deteriorates, which is not preferable. The ratio of 1,4-butanediol is 0.9 per mole of the total amount of the terephthalic acid component and the succinic acid component.
To 1.1 mol, preferably 0.95 to 1.1 mol. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 4, 2000 (200.9.4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Method for producing biodegradable polyester

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a manufacturing method of the biodegradable Poriesu <br/> Te Le.

[0002]

2. Description of the Related Art The disposal of plastic waste has become a serious social problem, and the recycling of plastics is becoming increasingly important. A typical example of plastics that are currently being recycled is PET bottles, but in the case of PET bottles, the problem that the amount of waste plastic generated exceeds the demand for recycled products has arisen. There is a need for even more effective usage. Also, if a biodegradable polymer that can be decomposed by microorganisms in the soil can be produced using waste PET bottles as a raw material, the environmental burden of landfill processing after reuse will be reduced, and it will be necessary to solve environmental problems. However, such a substance or technique has not been known.

[0003]

[0008] The present invention is directed to the object to provide a method for producing a biodegradable flop <br/>Rasuchi' click that can effectively utilize the waste PET bottles as a raw material.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have completed the present invention. That is, according to the present invention, a liquefaction process of waste PET bottle chips in which a waste product is obtained by reacting waste PET bottle chips with 1,4-butanediol at a temperature of 140 ° C. or more in the presence of a transesterification catalyst After adding dimethyl succinate to the liquid product and reacting it at 100 ° C. to 140 ° C. while flowing out methanol as a by-product, 190 ° C.
Heating to the above temperature and further reacting to form a polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component, and A method for producing a biodegradable polyester is provided, wherein the proportion is 5 to 40 mol % based on the total amount of the terephthalic acid component and the succinic acid component. Further , according to the present invention, after reacting dimethyl terephthalate, dimethyl succinate and 1,4-butanediol at 100 to 140 ° C. in the presence of a transesterification catalyst while allowing by-product methanol to flow, 190 ° C. or more And further reacted to obtain a terephthalic acid component, a succinic acid component, and 1,
Forming a polyester comprising a 4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to 40 mol % based on the total amount of the terephthalic acid component and the succinic acid component. A method for producing a biodegradable polyester is provided.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The biodegradable polyester of the present invention
Is it contain terephthalic acid component and succinic acid component and 1,4-butanediol as the essential component. In this case, the terephthalic acid component is preferably is derived from waste PET bottles, of course, may be derived from other products, further at least a portion of commercial terephthalic acid or terephthalic It may be derived from dimethyl acid. The number average molecular weight of the biodegradable polyester according to the present invention is 40,000 or more, preferably 50,000 or more, and the upper limit is not particularly limited, but is usually about 60,000.

In the biodegradable polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component according to the present invention, the proportion of the terephthalic acid component is as follows:
5 to the total amount of the terephthalic acid component and the succinic acid component
It is 40 mol%, preferably 10 to 37 mol%. When the proportion of the terephthalic acid component is larger than the above range, the biodegradability of the obtained polyester deteriorates, which is not preferable. The ratio of 1,4-butanediol is 0.9 per mole of the total amount of the terephthalic acid component and the succinic acid component.
To 1.1 mol, preferably 0.95 to 1.1 mol.

[0007] The biodegradable polyester of the present invention may contain other polymerizable components, such as other dicarboxylic acid components, oxycarboxylic acid components, and diol components, as necessary, without impairing the object of the present invention. It can be contained in the range.

The biodegradable polyester of the present invention can be produced using waste PET bottle chips as a raw material. According to this method, first, a plastic bottle chip is reacted with 1,4-butanediol in the presence of a transesterification catalyst to obtain a liquefied product. The reaction temperature in this case is 140 ° C. or higher, usually 160 to 210 ° C., preferably 180 ° C.
~ 200 ° C. The smaller the size of the PET bottle chip is, the more preferable it is. However, in general, it is preferable that the vertical and horizontal lengths are each 10 mm or less. As the transesterification catalyst, conventionally known various catalysts can be used. For example, titanium acetylacetonate and the like are preferably used.

The liquefaction reaction of the waste PET bottle chips is carried out by filling the PET bottle chips, 1,4-butanediol and a transesterification catalyst in a closed container, and heating. By this reaction, the pet (polyethylene terephthalate) constituting the chip is 1,4
Reacting with butanediol to oligomerize to obtain a liquid product;

[0010] Next, the manner in the co-Haq acid-dimethyl-the resulting liquid product in addition, if necessary, by addition of dimethyl terephthalate, the presence of a transesterification catalyst, reacted under heating with stirring . The reaction in this case is, first, 100
This is carried out at a temperature of １４０140 ° C. while escaping methanol as a by-product. When the outflow of methanol stops, the temperature is then increased to 190 ° C. or higher, usually 190 to 210 ° C., preferably 190 ° C.
The polycondensation reaction is completed by heating to a temperature of ~ 200 <0> C. Agitation in this reaction can be performed by bubbling nitrogen gas from the bottom of the reaction vessel.

[0011] According to another process for the preparation of biodegradable polyester of the present invention, terephthalic acid dimethyl, and dimethyl succinate and 1,4 butanediol le, in the presence and under stirring of a transesterification catalyst, 100-140
The reaction is carried out at a temperature of ° C. while allowing methanol by-product to flow out. When the outflow of methanol is stopped, the reaction (polycondensation reaction) is completed at a temperature of 190 ° C or higher, usually 190 to 210 ° C, preferably 190 to 200 ° C.

[0012]

Next, the present invention will be described in detail with reference to examples.

Example 1 (Reactor) A stainless steel autoclave having an internal volume of about 300 cc and having a vertical inlet was connected to a stainless steel pipe through a gas inlet of the autoclave so that gas could be bubbled from the bottom of the autoclave. (Synthesis of Polymer A) 2.23 g (0.0116 mol) of PET bottle chips washed with water and dried, 6.96 g (0.0772 mol) of 1,4-butanediol, and 2.5 mg of Ti acetylacetonate as a catalyst (0.009
5 mmol) was charged into the above-mentioned autoclave, and the autoclave valve was closed, and the mixture was stirred for 19 hours while being sealed.
Heat to 0 ° C. At this time, the pressure rises to a maximum of 0.08 MPa, and it is detected by a change in the stirring sound that the PET bottle chip has completely dissolved and the solid matter has disappeared. At this time, the PET bottle chips are decomposed by 1,4-butanediol to become oligomers and dissolved in the reaction solution. next,
The autoclave was cooled to room temperature, and 9.59 g (0.0656 mol) of dimethyl succinate was added to the obtained liquid product.
After charging, the outlet valve of the autoclave was opened, nitrogen was bubbled from the bottom of the vessel at a rate of 50 ml / min, and the mixture was stirred at 100 ° C. for 2 hours.
The reaction is carried out at 0 ° C. for 2 hours with the effluent of methanol.
The effluent methanol is collected in an ice-cooled trap. Next, the temperature was raised to 190 ° C., and a polycondensation reaction was performed for 7 hours while bubbling nitrogen at a rate of 0.9 l / min. The obtained copolycondensate (polymer A) contained a terephthalic acid component, had a softening point of 91.6 ° C, a flow starting point of 99.1 ° C, and a number average molecular weight of 48,000. As a result of a biodegradability test by embedding in soil for 4 weeks, the degradation rate was 28.7%.
The degradation rate of the polybutylene succinate homopolymer carried out in parallel is 49.6% and therefore the biodegradability based on the homopolymer is 57.9%. The biodegradation rate of the PET bottle chips performed in parallel was 0%. The polymer A contains 8 mol% of a terephthalic acid component, 42 mol% of a succinic acid component, and 47 mol of a 1,4-butanediol component.
It was confirmed to be composed of mol%.

[0014]Example 2  (Reaction apparatus) The same apparatus as described in Example 1 was used.
Was. (polymerBSynthesis of dimethyl terephthalate 2.43 g
(0.0125 mol), 16.5 g of dimethyl succinate
(0.113 mol), 11.7 1,4-butanediol
g (0.130 mol), and Ti acetyl acetate as a catalyst.
0.9 mg (0.003 mmol) of settonate as described above
Charged to autoclave, autoclave outlet valve
And bubble nitrogen from the bottom of the vessel at a rate of 50 ml / min.
While stirring at 100 ° C for 2 hours.
Raise methanol at 140 ° C for 2 hours
Respond. Effluent methanol is collected in an ice-cooled trap
You. Next, the temperature was increased to 190 ° C., and nitrogen was added at 0.5 l / m 2.
Perform polycondensation reaction for 7 hours while bubbling at the speed of in
I let you. The resulting copolycondensate (polymerB) Is terephthal
Contains an acid component, has a softening point of 103.6 ° C. and a flow starting point of 10
8.5 ° C., melting point 106.3 ° C., glass transition point −18.9
° C and the number average molecular weight was 36,000. 4 weeks in the soil
As a result of biodegradability test, the degradation rate was 56.2%.
there were. Polybutylene succinate homo
The degradation rate of the polymer was 63.5%,
Biodegradability based on mer is 89%. The polymer
ーBIs terephthalic acid component 5 mol%, succinic acid component 44
Mol% and 50 mol% of 1,4-butanediol component
It was confirmed that it consisted.

[0015]Example 3  (Reaction apparatus) The same apparatus as described in Example 1 was used.
Was. (polymerCOf synthetic PET bottles)
2.23 g (0.0116 mol) and 1,4-butane
6.96 g (0.0772 mol) of diol, and catalyst
2.6 mg of Ti acetylacetonate (0.009
9 mmol) in the above autoclave,
Close the valve of the clave and stir in a sealed
Heat to 0 ° C. At this time, the pressure reaches a maximum of 0.08MPa
As the plastic bottle tip dissolves completely and the solid matter disappears.
The disappearance is detected by a change in the stirring sound. At this time
Bottle chips are decomposed by 1,4-butanediol
Then, it becomes an oligomer and dissolves in the reaction solution. Next
Cool the autoclave to room temperature and add dimethyl terephthalate
3.00 g (0.0154 mol), dimethyl succinate
After charging 7.33 g (0.0502 mol),
Open the outlet valve of the clave and add 50 ml of nitrogen from the bottom of the vessel.
/ Min at 100 ° C. while stirring by bubbling
2 hours, then raise the temperature to 140 ° C for 2 hours
The reaction is carried out while escaping water. The effluent methanol is ice
Collect in cold trap. Next, raise the temperature to 190 ° C
And while bubbling nitrogen at a rate of 0.5 l / min,
The polycondensation reaction was performed for 7 hours. The obtained copolycondensate (Po
RemarC) Contains a terephthalate component and has a softening point of 95.
7 ° C., flow starting point 109.6 ° C., number average molecular weight 56,000
Met. Biodegradability test by embedding in soil for 4 weeks
As a result, the decomposition rate was 2.8%. Poly performed in parallel
The decomposition rate of butylene succinate homopolymer was 49.6.
% Biodegradability based on homopolymer
5.6%. In addition, PET bottle chips
The biodegradation rate of the pulp was 0%. The polymerCIs a tele
Phthalic acid component 18 mol%, succinic acid component 32 mol% and
Consisting of 47 mol% of 1,4-butanediol component
It was confirmed that there was.

[0016]Example 4  (Reaction apparatus) The same apparatus as described in Example 1 was used.
Was. (polymerDOf synthetic PET bottles)
1.48 g (0.00772 mol) of 1,4-buta
6.96 g (0.0772 mol) of diol and catalyst
2.5 mg of Ti acetylacetonate (0.00 mg
95 mmol) in the above autoclave,
Close the valve of the toclave and stir in a sealed
Heat to 90 ° C. At this time, the pressure is up to 0.08MPa
And the plastic bottle chips completely dissolve and solid matter
The disappearance is detected by a change in the stirring sound. At this time
PET bottle chips are divided by 1,4-butanediol
It is dissolved and becomes an oligomer and dissolves in the reaction solution. next
Cool the autoclave to room temperature and add dimethyl succinate 1
After charging 0.15 g (0.0695 mol),
Open the outlet valve of the clave and add 50 ml of nitrogen from the bottom of the vessel.
/ Min at 100 ° C. while stirring by bubbling
2 hours, then raise the temperature to 140 ° C for 2 hours
The reaction is carried out while escaping water. The effluent methanol is ice
Collect in cold trap. Next, raise the temperature to 190 ° C
And while bubbling nitrogen at a rate of 0.5 l / min,
The polycondensation reaction was performed for 7 hours. The obtained copolycondensate (Po
RemarD) Contains a terephthalate component and has a softening point of 10
0.4 ° C., starting point of flow 115.8 ° C., number average molecular weight 5.
It was 30,000. Biodegradability test by embedding in soil for 4 weeks
As a result of the test, the decomposition rate was 38.0%. Go in parallel
The decomposition rate of the polybutylene succinate homopolymer was 2
0.7% and therefore the raw material based on homopolymer
The resolvability is 184%. In addition, the pet bottle which went in parallel
The biodegradation rate of Lucip was 0%. The polymerD
Is terephthalic acid component 5 mol%, succinic acid component 45 mol
% And 1,4-butanediol component 47%
Was confirmed.

[0017]

The polyester of the present invention has good biodegradability while containing a terephthalic acid component. About 10 to 30% of the weight of the biodegradable polymer of the present invention is a terephthalic acid component, and this component is covered by the recycled weight of waste PET bottles. It is cheaper than nate. In addition, the method for producing the polyester of the present invention is much lower in cost than the conventional production method requiring a high vacuum. Therefore, according to the present invention, a biodegradable polymer less expensive than the conventional one can be obtained. In addition, the present invention is also useful as a social demand for recycling waste plastic bottles.

Continuing from the front page (71) Applicant 599132029 Sakaguchi Naoki 1-1-1, Higashi, Tsukuba, Ibaraki Pref. 4 agents 100074505 Patent Attorney Toshiaki Ikeura (72) Inventor Takashi Masuda 1-1-1, Higashi, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor Akio Matsuda 1-1-1, Higashi, Tsukuba, Ibaraki Industrial Institute of Technology, National Institute of Materials Science (72) Inventor Naoki Sakaguchi 1-1-1, Higashi, Tsukuba, Ibaraki Pref.Institute of Materials Science and Technology, National Institute of Advanced Industrial Science (72) Tatsuo Hamaya 1-1-1, Higashi, Tsukuba, Ibaraki, Japan F-term in Materials Engineering and Technology Laboratory (Reference) 4J029 AA03 AA05 AB01 AB04 AC02 AD10 BA05 CA04 CB06A EG10 JB151 JE162 JF321 KE02

Claims (7)

[Claims] 1. A terephthalic acid component, a succinic acid component and 1,
A biodegradable polyester comprising a 4-butanediol component, wherein the proportion of the terephthalic acid component is 5 to 50% by weight based on the total amount of the terephthalic acid component and the succinic acid component. 2. A terephthalic acid component, a succinic acid component and 6-
It comprises a hexanolactone component and a 1,4-butanediol component, and the ratio of the terephthalic acid component is 5 to 50 with respect to the total amount of the terephthalic acid component, the succinic acid component and the 6-hexanolactone component. A biodegradable polyester characterized by weight percent. 3. The biodegradable polyester according to claim 1, wherein the terephthalic acid component is derived from a waste plastic bottle. 4. A process for liquefying a waste PET bottle chip in which a waste PET bottle chip is reacted with 1,4-butanediol at a temperature of 140 ° C. or higher in the presence of a transesterification catalyst to obtain a liquid product. Dimethyl succinate is added to the liquid product and reacted at 100 ° C. to 140 ° C. while flowing out methanol as a by-product. The mixture is further heated to a temperature of 190 ° C. or higher to further react, and the terephthalic acid component and the succinic acid component are reacted. And a polyester producing step of producing a polyester comprising a 1,4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is 5 to the total amount of the terephthalic acid component and the succinic acid component. 50% by weight of the biodegradable polyester. 5. After reacting dimethyl terephthalate, dimethyl succinate and 1,4-butanediol at 100 to 140 ° C. in the presence of a transesterification catalyst while allowing methanol to flow as a by-product, the temperature is raised to 190 ° C. or higher. Heating and further reacting to form a polyester comprising a terephthalic acid component, a succinic acid component and a 1,4-butanediol component, wherein the proportion of the terephthalic acid component in the polyester is A method for producing a biodegradable polyester, comprising 5 to 50% by weight based on the total amount of a succinic acid component and succinic acid component. 6. Dimethyl terephthalate, dimethyl succinate, 1,4-butanediol and 6-hexanolactone are reacted in the presence of a transesterification catalyst at 100 to 140 ° C. while allowing methanol by-produced to flow out. Later, 19
Heating to a temperature of 0 ° C. or higher to further react to form a polyester comprising a terephthalic acid component, a succinic acid component, a 6-hexanolactone component, and a 1,4-butanediol component. The ratio of the terephthalic acid component in the terephthalic acid component, the succinic acid component, and the 6-hexanolactone component is 5%.
50% by weight of the biodegradable polyester. 7. The method according to claim 5, wherein the dimethyl terephthalate is derived from a waste plastic bottle.