CATALYST FOR PRODUCING POLYBUTYLENE SUCCINATE OR COPOLYESTER THEREOF, AND PREPARING MEHTODS OF THE CATALYST

Abstract

The present invention provides a catalyst used in the production of PBS or its copolyesters and the preparation method thereof. The method comprises the following steps: (1) adding titanium alkoxide, silicon alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system; (2) adding complexing agent into the reaction system, then collecting catalyst from the products obtained in this step. Moreover, the method may comprises steps of: (1) adding titanium alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system; (2) adding silicon alkoxide and complexing agent into the reaction system, then collecting catalyst from the products obtained in this step. The catalyst in the present invention has higher activity and thus the catalyst additional amount is reduced which will improve the quality of the products. Moreover, the catalyst in the present invention could be used alone in the production of PBS or its copolyester without the need for other materials and it won't react with water and thus could be stored for a long time. In sum, the catalyst in the present invention has a broad prospect in industrial application.

Description

FIELD OF THE INVENTION

The present invention relates to a catalyst used in the production of PBS or its copolyesters and the preparation method thereof.

BACKGROUND OF THE INVENTION

Aliphatic polyesters has aroused wide attention and research from domestic and foreign scholars because of their great biodegradable and environmentally non-persistent properties. Aliphatic polyesters and in particular poly (butylene succinate) (PBS) even have additional advantage features, such as good mechanical and processing properties. Therefore, PBS, which has enormous application prospect, becomes the focus of attention in industry recently.

Previous attempts at the production of PBS or its copolyesters are generally fall into two kinds of production processes, chain extending process and direct polycondensation process. In the chain extending process, chain extender is added into the reaction system to react with the organic groups of the polyesters in order to increase molecular weight. In general, the chain extenders mainly used are isocyanide alkoxides which are poisonous compounds and can't be used in food-related field. Because of the above property, the application of PBS or its copolyesters has been limited. Compared with chain extending process, the manufacture process and equipment of the direct polycondensation process are almost the same, however, there is no such poison chain extenders required in direct polycondensation process. Therefore, direct polycondensation process will become the most popular manufacture method for PBS or its copolyesters in the future.

In the direct polycondensation process used to produce PBS or its copolyesters, the polycondensation catalyst, such as titanium-based catalyst or the mixture of titanium-based catalyst and other metal catalyst, is added into the reaction system. Chinese Patent application, CN 1424339 discloses a catalyst mixture comprising stannic oxide, antimony trioxide, cadmium acetate and titanium alkoxides. Moreover, Chinese Patent application, CN 1861660A discloses a catalyst mixture comprising tetra-n-butyl titanate, tetra-isopropyl titanate, antimony trioxide and tetra-n-butyl germinate. In practical manufacture process, titanate-based catalyst alone can't satisfy production requirements. Therefore, other compounds must be added into titanate catalyst to form a catalyst complex.

In light of the above, the catalyst system in prior art has following disadvantages such as: (1) The traditional catalyst has low activity and thus the additional amount of catalyst is very high which affects the quality of the products. For the traditional titanium alkoxides-based catalyst, additional amount of active ingredient (titanium) usually more than 500 ppm (that is, 500×10⁻⁶ gTi/gPBS, similarly hereinafter), measured by weight of PBS. Sometimes the additional amount is even higher than 700 ppm. Such high catalyst amount could result in many side reactions and it may also increase the melt flow rate of the products, decrease its mechanical properties and turn the products a dark yellow color. (2) The catalyst in prior art is not convenient for practical manufacture use because titanium alkoxides would easily cause precipitation while contacting with water. However, during PBS synthesis procedure, because the product in esterification procedure is water, titanium alkoxides could be added only after the esterification procedure. On the other hand, the catalyst in prior art is composed of several other ingredients, the technicians must prepare for each components according to its proportion which is a complex procedure comparing with the single-component catalyst.

SUMMARY OF THE INVENTION

The present invention provides a catalyst used in the production of PBS or its copolyesters and the preparation method thereof.

Consistent with one preferable embodiment of the present invention, a manufacturing method of the catalyst used in the production of PBS or its copolyesters is provided. The method comprises steps of:

(1) adding titanium alkoxide, silicon alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., more preferably 85° C. to 160° C., for 0.5 hour to 2.5 hours;
(2) removing the unreacted materials and small molecular products in the reaction system obtained in step (1);
(3) adding complexing agent into the reaction system obtained in step (2) and conducting the reaction at a temperature of about 80° C. to 180° C., more preferably 85° C. to 160° C., for 0.5 hour to 2.5 hours;
(4) removing small molecular products in the reaction system obtained in step (3) and then catalyst could be obtained.

Consistent with another preferable embodiment of the present invention, a manufacturing method of the catalyst used in the production of PBS or its copolyesters is provided. The method comprises steps of:

(1) adding titanium alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., more preferably 85° C. to 160° C., for 0.5 hour to 2.5 hours;
(2) removing the unreacted materials and small molecular products in the reaction system obtained in step (1);
(3) adding silicon alkoxide and complexing agent into the reaction system obtained in step (2) and conducting the reaction at a temperature of about 80° C. to 180° C., more preferably 85° C. to 160° C., for 0.5 hour to 2.5 hours;
(4) removing small molecular products in the reaction system obtained in step (3) and then catalyst could be obtained.

The method used for removing the unreacted materials or small molecular products in the reaction system could adopt any conventional methods known by those skilled in the art, such as distillation or rectification method, and any other methods which could be adopted by the skilled in the art.

Preferably, said titanium alkoxide is selected from the group comprising tetra-n-butyl titanate, tetra-isopropyl titanate and the mixture thereof.

Preferably, said silicon alkoxide is selected from the group comprising methyl silicate, ethyl silicate and the mixture thereof.

Surprisingly, the metal co-catalyst and complexing agent both have great influence on catalyst activity and the choices on the catalysts.

Preferably, the said metal co-catalyst is selected from the acetates or alkoxides of Group IIA, IIIA, IIB or VIIIB metals, or any mixture thereof. More preferably, the said metal co-catalyst is selected from the group comprising zinc acetate, aluminium isopropoxide, calcium acetate, magnesium acetate, manganese acetate and any mixture thereof.

The said dihydric alcohol is selected from the group comprising 1,4-butanediol, ethanediol, 1,3-propanediol, 2-methyl-2,4-pentadiol, 1,5-pentanediol, 1,6-hexanediol and any mixture thereof.

Preferably, the said complexing agent comprises phosphate ester and hydroxyl carboxylic acids.

More preferably, the said phosphate ester is selected from the group comprising trimethyl phosphate, trimethyl phosphite, triethyl phosphate, triethyl phosphite and any mixture thereof.

More preferably, the said hydroxyl carboxylic acids is selected from the group comprising citric acid, tartaric acid, lactic acid and any mixture thereof.

Preferably, the said solvent is selected from the group comprising ethanol, n-butanol, isopropanol and any mixture thereof.

Preferably, the molar ratio of titanium atom and dihydric alcohol is ranging from 1:5 to 1:30, more preferably ranging from 1:20 to 1:30.

Preferably, the molar ratio of titanium atom and the metal co-catalyst is ranging from 1:0.05 to 1:2, more preferably ranging from 1:0.05 to 1:0.5.

Preferably, the molar ratio of titanium atom and hydroxyl carboxylic acids is ranging from 1:0.5 to 1:2, more preferably ranging from 1:0.5 to 1:1.5.

Preferably, the molar ratio of titanium atom and silicon atom is ranging from 1:0.01 to 1:2, more preferably ranging from 1:0.05 to 1:1.

Preferably, the molar ratio of titanium atom and phosphorus atoms is ranging from 1:0.01 to 1:2, more preferably ranging from 1:0.01 to 1:1.5.

Preferably, the molar ratio of titanium atom and the solvent is ranging from 1:5 to 1:50, more preferably ranging from 1:5 to 1:30.

The catalyst prepared according to the above methods could be used in the production of PBS or its copolyester. During the preparation for PBS or its copolyester adopting succinic acid and 1,4-butanediol as the main raw monomer materials, the above-mentioned catalyst could be added directly into the reaction system or be added into the reaction system after being diluted with 1,4-butanediol. Moreover, the catalyst also could be added into the reaction system before the esterification reaction, or be added into the reaction system after the esterification reaction and before the start of the prepolycondensation.

The amount of catalyst added could be determined by the weight of titanium atoms it contains, and the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is ranging from 80×10^−6:1˜200×10⁻⁶:1.

Preferably, the amount of catalyst could be determined by the weight of titanium atoms it contained, and the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is ranging from 100×10⁻⁶:1˜150×10⁻⁶:1.

Compared with the traditional titanium alkoxides catalyst, the catalyst containing metal co-catalyst in the present invention, which is prepared using complexation technology, has the following advantages. Firstly, the catalyst in the present invention has higher activity and thus the catalyst additional amount is reduced which will improve the quality of the products. Secondly, the catalyst in the present invention could be used alone in the production of PBS or its copolyester without the need for other materials. Therefore, there is no need for additional preparation step as in the traditional preparation method. Thirdly, the catalyst in the present invention will not react with water and it thus could be added into the reaction system before the esterification reaction, or after the esterification reaction and before the start of the prepolycondensation. In addition, the catalyst in the present invention could be stored for a long time. In sum, the catalyst in the present invention has a broad prospect in industrial application.

DETAIL DESCRIPTION OF THE INVENTION

The present disclosure is further explained in detail according to the accompanying embodiments. The above description of the detailed embodiments are only to illustrate the preferred implementation according to the present invention, and it is not to limit the scope of the present invention, Accordingly, all modifications and variations completed by those with ordinary skill in the art should fall within the scope of present invention defined by the appended claims.

In the following embodiments, the melt mass-flow rate of PBS is measured according to the determination method in “GB/T 3682-2000 Determination of the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR) of thermoplastics”. The color of PBS is estimated using L, a, b-color system as assessment baseline. In this L, a, b-color system, “L” means luminance factor, “a” and “b” mean color measurement numbers. The “b”, which is used to estimate yellow-blue balance, is a significant evaluation number for the color of polyesters. A lower “b” value is a sign of a better color.

The First Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 1.73 g of calcium acetate (0.0098 mol) into the flask,
(2) after that, add 29 g of tetra-n-butyl titanate (0.0852 mol) and 31.51 g of ethanol (0.685 mol) into the flask, then conduct the reaction at a temperature of 80° C. for 2.5 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 2.04 g of tetraethoxysilane (0.0098 mol) and 8.22 g of tartaric acid (0.0548 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 80° C. for 2.5 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in liquid state which contains 5.12% of titanium by weight could be obtained.

The Second Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 2.4 g of manganese acetate (0.0098 mol) into the flask,
(2) after that, add 19.44 g of tetra-isopropyl titanate (0.0685 mol) and 31.51 g of ethanol (0.685 mol) into the flask, then conduct the reaction at a temperature of 110° C. for 0.5 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 1.02 g of tetraethoxysilane (0.0049 mol) and 12.76 g of trimethyl phosphite (0.1028 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 110° C. for 0.5 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 4.14% of titanium by weight could be obtained.

The Third Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 2.2 g of zinc acetate (0.01 mol) into the flask,
(2) after that, add 22.80 g of tetra-n-butyl titanate (0.067 mol) and 92.46 g of ethanol (2.01 mol) into the flask, then conduct the reaction at a temperature of 180° C. for 1 hour,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 8.41 g of citric acid (0.04 mol), 5.10 g of tartaric acid (0.034 mol), 2.08 g of tetraethoxysilane (0.01 mol) and 6.74 g of triethyl phosphate (0.037 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 180° C. for 1 hour;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 4.02% of titanium by weight could be obtained.

The Fourth Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 100 g of 1,4-butanediol (1.11 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 3.29 g of zinc acetate (0.015 mol) into the flask,
(2) after that, add 10.21 g of tetra-n-butyl titanate (0.03 mol), 8.517 g of tetra-isopropyl titanate (0.03 mol), 3.12 g of tetraethoxysilane (0.015 mol) and 46 g of ethanol (1 mol) into the flask, then conduct the reaction at a temperature of 100° C. for 1 hour,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 9.05 g of lactic acid (0.105 mol) and 14.22 g of trimethyl phosphate (0.1 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 150° C. for 1.2 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 2.01% of titanium by weight could be obtained.

The Fifth Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 3.22 g of magnesium acetate (0.015 mol) and 1.02 g of aluminium isopropoxide (0.005 mol) into the flask,
(2) after that, add 22.80 g of tetra-n-butyl titanate (0.067 mol), 3.12 g of tetraethoxysilane (0.015 mol) and 46 g of ethanol (1 mol) into the flask, then conduct the reaction at a temperature of 80° C. for 2.5 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 10.06 g of tartaric acid (0.067 mol) and 18.22 g of triethyl phosphate (0.1 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 80° C. for 1.2 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 3.24% of titanium by weight could be obtained.

The Sixth Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 3.29 g of zinc acetate (0.015 mol) and 1.76 g of calcium acetate (0.01 mol) into the flask,
(2) after that, add 22.80 g of tetra-n-butyl titanate (0.067 mol) and 46 g of ethanol (1 mol) into the flask, then conduct the reaction at a temperature of 180° C. for 1.8 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 7.04 g of citric acid (0.034 mol), 2.28 g of methyl silicate (0.015 mol) and 14.22 g of triethyl phosphate (0.1 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 120° C. for 2 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 3.49% of titanium by weight could be obtained.

The Seventh Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 50 g of 1,4-butanediol (0.55 mol), 2.04 g of aluminium isopropoxide (0.01 mol) and 2.45 g of manganese acetate (0.01 mol) into a 250 ml flask which is equipped with propeller and condensing unit,
(2) after that, add then add 22.80 g of tetra-n-butyl titanate (0.067 mol) and 46 g of ethanol (1 mol) into the flask, then conduct the reaction at a temperature of 80° C. for 2.5 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 10.55 g of citric acid (0.050 mol), 3.12 g of tetraethoxysilane (0.015 mol) and 12.41 g of trimethyl phosphite (0.1 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 80° C. for 2.5 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 3.42% of titanium by weight could be obtained.

The Eighth Embodiment

Consistent with this embodiment, the manufacturing method of the catalyst used in the production of PBS or its copolyesters comprises steps of:
(1) add 31 g of ethanediol (0.5 mol) and 45.45 g of 1,4-butanediol (0.5 mol) into a 250 ml flask which is equipped with propeller and condensing unit, then add 2.04 g of aluminium isopropoxide (0.01 mol) and 1.73 g of calcium acetate (0.0098 mol) into the flask,
(2) after that, add 22.80 g of tetra-n-butyl titanate (0.067 mol) and 31 g of ethanol (0.67 mol) into the flask, then conduct the reaction at a temperature of 80° C. for 2.5 hours,
(3) remove small molecular products in the reaction system obtained in step (2) by dilution,
(4) add 14.14 g of citric acid (0.067 mol), 13.96 g of tetraethoxysilane (0.067 mol) and 12.41 g of trimethyl phosphite (0.1 mol) into the reaction system in step (3) and conduct the reaction at a temperature at a temperature of 80° C. for 2.5 hours;
(5) remove small molecular products in the reaction system obtained in step (4) by dilution and then catalyst in fluid state which contains 2.34% of titanium by weight could be obtained.

The Ninth Embodiment

Consistent with this embodiment, the production of PBS using the catalyst obtained in the previous embodiment comprises steps of:

• • mix 6 mol of succinic acid and 7.2 mol of 1,4-butanediol together, then add 2.4 g of the catalyst obtained in the first embodiment (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 123 ppm), and then conduct the esterification reaction at a temperature of 230° C., then conduct the polycondensation after the esterification reaction directly and the final polycondensation is proceeded at a temperature of 240° C. and at a pressure of 35 Pa for 120 minutes, after that, PBS products are obtained. The melt flow rate of the PBS product is 15 g/10 min and the “b” value of the PBS product is 4.2.

The Tenth Embodiment

Consistent with this embodiment, the production of PBS using the catalyst obtained in the previous embodiment comprises steps of:

• • mix 6 mol of succinic acid and 7.2 mol of 1,4-butanediol together, then conduct the esterification reaction at a temperature of 230˜240° C., after the water yield in the esterification has reached 90% or more than 90% of the theoretic result, add 3.6 g of the catalyst obtained in the second embodiment (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 150 ppm), then conduct the polycondensation and the final polycondensation is proceeded at a temperature of 240° C. and at a pressure of 35 Pa for 120 minutes, after that, PBS products are obtained. The melt flow rate of the PBS product is 6 g/10 min and the “b” value of the PBS product is 7.0.

The Eleventh Embodiment

Consistent with this embodiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the tenth embodiment, however, the catalyst added is different. There are 2.5 g of the catalyst obtained in the third embodiment is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 100 ppm), after the final polycondensation which is proceeded for 140 minutes, PBS products are obtained. The melt flow rate of the PBS product is 16 g/10 min and the “b” value of the PBS product is 5.6.

The Twelfth Embodiment

Consistent with this embodiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the tenth embodiment, however, the catalyst added is different. There are 7 g of the catalyst obtained in the fourth embodiment is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 140 ppm), after the final polycondensation which is proceeded for 105 minutes, PBS products are obtained. The melt flow rate of the PBS product is 20 g/10 min and the “b” value of the PBS product is 4.5.

The Thirteenth Embodiment

Consistent with this embodiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the ninth embodiment, however, the catalyst added is different. There is 4 g of the catalyst obtained in the fifth embodiment is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 130 ppm), after the final polycondensation which is proceeded for 108 minutes, PBS products are obtained. The melt flow rate of the PBS product is 18 g/10 min and the “b” value of the PBS product is 4.9.

The Fourteenth Embodiment

Consistent with this embodiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the tenth embodiment, however, the catalyst added is different. There are 3 g of the catalyst obtained in the sixth embodiment is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 105 ppm), after the final polycondensation which is proceeded for 134 minutes, PBS products are obtained. The melt flow rate of the PBS product is 16 g/10 min and the “b” value of the PBS product is 5.3.

The Fifteenth Embodiment

Consistent with this embodiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the tenth embodiment. However, the catalyst added is different. There are 3.5 g of the catalyst obtained in the seventh embodiment is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 120 ppm), after the final polycondensation which is proceeded for 125 minutes, PBS products are obtained. The melt flow rate of the PBS product is 19 g/10 min and the “b” value of the PBS product is 3.9.

The Sixteenth Embodiment

Consistent with this embodiment, the production of PBS using the catalyst obtained in the previous embodiment comprises steps of:

mix 5 mol of succinic acid, 1 mol of terephthalic acid, 6 mol of 1,4-butanediol and 1.3 mol of ethanediol together, then conduct the esterification reaction at a temperature of 230˜250° C., after the water yield in the esterification has reached 90% or more than 90% of the theoretic result, add 6.4 g of the catalyst obtained in the eighth embodiment (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 150 ppm), then mix the reaction system and conduct the polycondensation and the final polycondensation is proceeded at a temperature of 275° C. and at a pressure of 35 Pa for 140 minutes, after that, copolyester products containing PBS and polyethylene terephthalate(PET) are obtained. The melt flow rate of the products is 8 g/10 min and the “b” value of the PBS product is 6.2.

Comparison Experiment

Consistent with this comparison experiment, the production process of PBS using the catalyst obtained in the previous embodiment comprises almost the same steps with the tenth embodiment. However, the catalyst added is different. There is 4 g of tetrabutyl titanate is added (the weight ratio of titanium atoms contained in the catalyst and total weight of PBS or its copolyester is 560 ppm), after the final polycondensation which is proceeded for 125 minutes, PBS products are obtained. The melt flow rate of the PBS product is 25g/10 min and the “b” value of the PBS product is 15.7.

The above description of the detailed embodiments are only to illustrate the preferred implementation according to the present invention, and it is not to limit the scope of the present invention, Accordingly, all modifications and variations completed by those with ordinary skill in the art should fall within the scope of present invention defined by the appended claims.

Claims

1. A manufacturing method of the catalyst used in the production of PBS or its copolyesters comprising steps of:

(1) adding titanium alkoxide, silicon alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system;

(2) adding complexing agent into the reaction system obtained in step (1) and conducting the reaction at a temperature of about 80° C. to 180° C., then collecting catalyst from the products obtained in this step.

2. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 1, wherein the reaction time in step (1) is ranging from 0.5 hour to 2.5 hours and the reaction temperature in step (1) is ranging from 85° C. to 160° C.

3. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 1, wherein the reaction time in step (2) is ranging from 0.5 hour to 2.5 hours and the reaction temperature in step (2) is ranging from 85° C. to 160° C.

4. A manufacturing method of the catalyst used in the production of PBS or its copolyesters comprising steps of:

(1) adding titanium alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system;

(2) adding silicon alkoxide and complexing agent into the reaction system obtained in step (1) and conducting the reaction at a temperature of about 80° C. to 180° C., then collecting catalyst from the products obtained in this step.

5. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 4, wherein the reaction time in step (1) is ranging from 0.5 hour to 2.5 hours and the reaction temperature in step (1) is ranging from 85° C. to 160° C.

6. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 4, wherein the reaction time in step (2) is ranging from 0.5 hour to 2.5 hours and the reaction temperature in step (2) is ranging from 85° C. to 160° C.

7. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 1, wherein the titanium alkoxide is selected from the group comprising tetra-n-butyl titanate, tetra-isopropyl titanate and the mixture thereof, and the silicon alkoxide is selected from the group comprising methyl silicate, ethyl silicate and the mixture thereof.

8. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 1, wherein the metal co-catalyst is selected from the group comprising acetates or alkoxides of Group IIA, IIIA, IIB or VIIIB metals, or any mixture thereof;

the dihydric alcohol is selected from the group comprising 1,4-butanediol, ethanediol, 1,3-propanediol, 2-methyl-2,4-pentadiol, 1,5-pentanediol, 1,6-hexanediol and any mixture thereof;

the solvent is selected from the group comprising ethanol, n-butanol, isopropanol and any mixture thereof;

the complexing agent comprises phosphate ester and hydroxyl carboxylic acid.

9. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 8, wherein the metal co-catalyst is selected from the group comprising zinc acetate, aluminium isopropoxide, calcium acetate, magnesium acetate, manganese acetate and any mixture thereof;

the phosphate ester is selected from the group comprising trimethyl phosphate, trimethyl phosphite, triethyl phosphate, triethyl phosphite and any mixture thereof;

the hydroxyl carboxylic acids is selected from the group comprising citric acid, tartaric acid, lactic acid and any mixture thereof;

the molar ratio of titanium atom and dihydric alcohol is ranging from 1:5 to 1:30;

the molar ratio of titanium atom and metal co-catalyst is ranging from 1:0.05 to 1:2;

the molar ratio of titanium atom and hydroxyl carboxylic acids is ranging from 1:0.5 to 1:2;

the molar ratio of titanium atom and silicon atom is ranging from 1:0.01 to 1:2;

the molar ratio of titanium atom and phosphorus atoms is ranging from 1:0.01 to 1:2;

the molar ratio of titanium atom and solvent is ranging from 1:5 to 1:50.

10. The catalyst used in the production of PBS or its copolyesters obtained by the method of claim 1.

11. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 4, wherein the titanium alkoxide is selected from the group comprising tetra-n-butyl titanate, tetra-isopropyl titanate and the mixture thereof, and the silicon alkoxide is selected from the group comprising methyl silicate, ethyl silicate and the mixture thereof.

12. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 4, wherein the metal co-catalyst is selected from the group comprising acetates or alkoxides of Group IIA, IIIA, IIB or VIIIB metals, or any mixture thereof;

the dihydric alcohol is selected from the group comprising 1,4-butanediol, ethanediol, 1,3-propanediol, 2-methyl-2,4-pentadiol, 1,5-pentanediol, 1,6-hexanediol and any mixture thereof;

the solvent is selected from the group comprising ethanol, n-butanol, isopropanol and any mixture thereof;

the complexing agent comprises phosphate ester and hydroxyl carboxylic acid.

13. The manufacturing method of the catalyst used in the production of PBS or its copolyesters, as recited in claim 12, wherein the metal co-catalyst is selected from the group comprising zinc acetate, aluminium isopropoxide, calcium acetate, magnesium acetate, manganese acetate and any mixture thereof;

the phosphate ester is selected from the group comprising trimethyl phosphate, trimethyl phosphite, triethyl phosphate, triethyl phosphite and any mixture thereof;

the hydroxyl carboxylic acids is selected from the group comprising citric acid, tartaric acid, lactic acid and any mixture thereof;

the molar ratio of titanium atom and dihydric alcohol is ranging from 1:5 to 1:30;

the molar ratio of titanium atom and metal co-catalyst is ranging from 1:0.05 to 1:2;

the molar ratio of titanium atom and hydroxyl carboxylic acids is ranging from 1:0.5 to 1:2;

the molar ratio of titanium atom and silicon atom is ranging from 1:0.01 to 1:2;

the molar ratio of titanium atom and phosphorus atoms is ranging from 1:0.01 to 1:2;

the molar ratio of titanium atom and solvent is ranging from 1:5 to 1:50.

14. The catalyst used in the production of PBS or its copolyesters obtained by the method of claim 4.