阅读说明：本技术 一种耐高温膜用聚酯切片的合成方法 (Synthesis method of polyester chip for high-temperature-resistant film ) 是由 段旻 刘勤学 姚孝平 孔云飞 马强 杨彩怡 于 2021-08-05 设计创作，主要内容包括：本发明属于聚酯切片制备技术领域,提供一种耐高温膜用聚酯切片的合成方法,包括以下步骤：将2-萘氧乙酸钠和2-萘氧基乙酸混合物加入乙二醇溶液中,再加入苯二甲酸,将混合好的浆料转移至一酯化反应釜,制得BHET及其衍生物中间体的混合浆液；在二酯化反应釜中投加聚对苯二甲酸丁二醇酯、复配催化剂、UV单体和抗氧剂,加入乙二醇和3-戊醇进行反应,得到混合熔融浆液；将以上两种酯化反应产物放入缩聚反应釜缩聚,切粒、干燥,得到聚酯切片。本发明合成的聚酯切片软化温度从普通聚酯切片的70-80℃提高到95℃,熔点提高至200℃以上,可以减少聚氨切片在干燥和螺旋挤出时的粘连现象的发生,具有良好的高温实用性能,为后续制膜提供良好的物理基础。(The invention belongs to the technical field of polyester chip preparation, and provides a synthetic method of a polyester chip for a high-temperature-resistant film, which comprises the following steps: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, and transferring the mixed slurry to an esterification reaction kettle to prepare mixed slurry of BHET and a derivative intermediate thereof; adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, and adding ethylene glycol and 3-pentanol to react to obtain mixed molten slurry; and putting the two esterification reaction products into a polycondensation reaction kettle for polycondensation, granulating and drying to obtain the polyester chip. The softening temperature of the polyester chip synthesized by the method is increased from 70-80 ℃ of the common polyester chip to 95 ℃, the melting point is increased to more than 200 ℃, the occurrence of the adhesion phenomenon of the polyurethane chip during drying and spiral extrusion can be reduced, the high-temperature practical performance is good, and a good physical basis is provided for subsequent film making.)

1. A method for synthesizing polyester chips for high-temperature-resistant films is characterized by comprising the following steps:

s1, adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, and transferring the mixed slurry to an esterification reaction kettle to prepare mixed slurry of a BHET (BHET) and a derivative intermediate thereof;

s2, adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, and after the materials are added, adding ethylene glycol and 3-pentanol to react to obtain mixed molten slurry;

s3, when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.5-2.0h in a nitrogen atmosphere, heating the temperature of the mixed solution to 245-plus-255 ℃, and pressing the mixed solution into a polycondensation reaction kettle from a diester kettle through a filter;

and S4, after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ and the vacuum degree of not more than 30Pa to synthesize high-viscosity polyester chip melt, and carrying out granulation and drying to obtain the polyester chip.

2. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein:

the compound catalyst is a mixture of a titanium catalyst and an antimony catalyst.

3. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 2, wherein:

the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.5-2.

4. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein:

the antioxidant is triphenyl phosphate.

5. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: the UV monomer is acrylic resin.

6. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: the melt viscosity of the high-viscosity polyester chip is not less than 0.82 DL/g.

7. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: the temperature of the two esterification reactions is 230-250 ℃.

8. The method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: in the step S1, the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1-1.1; the molar ratio of the mixture to the ethylene glycol is 1:10-12, the molar ratio of the ethylene glycol to the phthalic acid is 0.9-1.05: 1.

9. the method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: in the step of S2, the mole ratio of the glycol to the 3-pentanol is 1.2-1.4: 1.

10. the method for synthesizing polyester chip for high temperature resistant film as claimed in claim 1, wherein: the mass of the polybutylene terephthalate in the step S3 accounts for 10-15% of the total mass of the total mixed solution.

Technical Field

The invention relates to the technical field of polyester chip preparation, in particular to a synthesis method of a polyester chip for a high-temperature-resistant film.

Background

The polyester chip can be made into polyester film, can be widely applied to the fields of packaging, electronics and the like, and has excellent mechanical properties, good dimensional stability, high transparency and chemical resistance. However, the softening point of the polyester chip is generally 70-80 ℃, and the drying temperature of the polyester chip is generally 160-175 ℃, so that the directly dried polyester chip is seriously adhered, and the extrusion molding effect is poor. In addition, the high temperature resistance of the prepared polyester film can be improved by adding the additive into the polyester chip master batch, but the addition of the additive brings new problems such as reduction of the permeability, tinting strength and durability of the film.

Disclosure of Invention

In order to overcome at least one of the defects, the invention provides a synthesis method of a polyester chip for a high-temperature-resistant film, the polyester chip prepared by the method has the advantages of high softening point, easy extrusion molding, good effect and high temperature resistance, and can be used as an additive in the preparation of the high-temperature-resistant film to improve the physical and chemical properties of the high-temperature-resistant film.

In order to achieve the above purpose, the technical scheme of the invention is as follows: a method for synthesizing polyester chips for high-temperature-resistant films comprises the following steps:

s1, adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, and transferring the mixed slurry to an esterification reaction kettle to prepare mixed slurry of a BHET (BHET) and a derivative intermediate thereof;

s2, adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, and after the materials are added, adding ethylene glycol and 3-pentanol to react to obtain mixed molten slurry;

s3, when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.5-2.0h in a nitrogen atmosphere, heating the temperature of the mixed solution to 245-plus-255 ℃, and pressing the mixed solution into a polycondensation reaction kettle from a diester kettle through a filter;

and S4, after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ and the vacuum degree of not more than 30Pa to synthesize high-viscosity polyester chip melt, and carrying out granulation and drying to obtain the polyester chip.

In some preferred embodiments, the compound catalyst is a mixture of a titanium-based catalyst and an antimony-based catalyst.

In some preferred embodiments, the compounded catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.5-2.

In some preferred embodiments, the antioxidant is triphenyl phosphate.

In some preferred embodiments, the UV monomer is an acrylic resin.

In some preferred embodiments, the high viscosity polyester chip melt viscosity is not less than 0.82 DL/g.

In some preferred embodiments, the temperature of the two esterification reactions is from 230 ℃ to 250 ℃.

In some preferred embodiments, the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid in step S1 is 1:1 to 1.1; the molar ratio of the mixture to the ethylene glycol is 1:10-12, the molar ratio of the ethylene glycol to the phthalic acid is 0.9-1.05: 1.

in some preferred embodiments, the mole ratio of ethylene glycol to 3-pentanol in the S2 step is 1.2-1.4: 1.

in some preferred embodiments, the mass of the polybutylene terephthalate in the step S3 is 10% to 15% of the total mass of the total mixed liquor.

Compared with the prior art, the invention has the beneficial effects and advantages that:

the softening temperature of the polyester chip synthesized by the method is increased from 70-80 ℃ of the common polyester chip to 95 ℃, the melting point is increased to more than 200 ℃, the occurrence of the adhesion phenomenon of the polyurethane chip during drying and spiral extrusion can be reduced, the high-temperature practical performance is good, and a good physical basis is provided for subsequent film making. The prepared film has high softening temperature, MD (MD) tensile strength and TD tensile strength, has good high-temperature resistance, and increases the mechanical property and dimensional stability of the film prepared from the polyester chip.

Detailed Description

The present invention will be described in further detail by way of examples, but the present invention is not limited thereto, in order to make the objects, technical solutions and advantages of the present invention more apparent.

A method for synthesizing polyester chips for high-temperature-resistant films comprises the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 230-250 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1-1.1; the molar ratio of the mixture to the ethylene glycol is 1:10-12, the molar ratio of the ethylene glycol to the phthalic acid is 0.9-1.05: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol to react after the materials are added, wherein the temperature of esterification reaction is 230-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.2-1.4: 1, mixing and compounding a titanium catalyst and an antimony catalyst, wherein the compounded catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.5-2, wherein the antioxidant is triphenyl phosphate, and the UV monomer is acrylic resin; the structure of the polyester can be improved by adding a certain amount of 3-pentanol, the mutual adsorbability and the space entanglement of the polyester respectively prepared from the 3-pentanol and the glycol are increased, the heat resistance is improved, and the molar ratio of the glycol to the 3-pentanol is controlled to be 1.2-1.4: 1, on one hand, the production cost is saved, and on the other hand, the types of polyester chips are limited, so that the later film-making uniformity is not influenced.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.5-2.0h in a nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 10% -15% of the total mass of the mixed solution, heating the temperature of the mixed solution to 245-plus-255 ℃, and pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt, wherein the viscosity of the high-viscosity polyester chip melt is not less than 0.82DL/g, and carrying out granulation and drying to obtain the polyester chip.

The present invention will be described in further detail with reference to the following specific examples, which are not intended to limit the scope of the present invention in any way, and reagents and starting materials used in the present invention are commercially available except for those prepared by themselves.

Embodiment 1, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 240-250 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1; the molar ratio of the mixture to ethylene glycol was 1:10, the molar ratio of ethylene glycol to phthalic acid was 0.9: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol for reaction after the materials are added, wherein the temperature of esterification reaction is 240-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.2: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.5, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 4.0%, 0.5% and 1.0% of the mixed molten slurry.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed of 1.5 under the nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 10% of the total mass of the mixed solution, and after the temperature of the mixed solution is raised to 245-plus-255 ℃, pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt, wherein the viscosity of the high-viscosity polyester chip melt is 0.83DL/g, and carrying out granulation and drying to obtain the polyester chip.

Embodiment 2, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 240-250 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1; the molar ratio of the mixture to ethylene glycol was 1:10, the molar ratio of ethylene glycol to phthalic acid was 0.95: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol for reaction after the materials are added, wherein the temperature of esterification reaction is 240-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.3: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.6, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 3.8%, 0.4% and 1.0% of the mixed molten slurry.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.6h in a nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 11% of the total mass of the mixed solution, and pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter after the temperature of the mixed solution is raised to 245-plus-255 ℃;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt, wherein the viscosity of the high-viscosity polyester chip melt is 0.84DL/g, and carrying out granulation and drying to obtain the polyester chip.

Embodiment 3, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 230-240 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1.05; the molar ratio of the mixture to ethylene glycol was 1:10.5, the molar ratio of ethylene glycol to phthalic acid was 0.95: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol to react after the materials are added, wherein the temperature of esterification reaction is 230-240 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.3: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.7, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 3.5%, 0.2% and 1.0% of the mixed molten slurry;

s3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.6h in a nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 12% of the total mass of the mixed solution, and pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter after the temperature of the mixed solution is raised to 245-plus-255 ℃;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt, wherein the viscosity of the high-viscosity polyester chip melt is 0.85DL/g, and carrying out granulation and drying to obtain the polyester chip.

Embodiment 4, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 230-240 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1.05; the molar ratio of the mixture to ethylene glycol is 1:11, the molar ratio of ethylene glycol to phthalic acid is 1:1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol for reaction after the materials are added, wherein the temperature of esterification reaction is 240-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.3: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.8, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 3%, 0.2% and 1.0% of the mixed molten slurry.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 1.6h in a nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 13% of the total mass of the mixed solution, and pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter after the temperature of the mixed solution is raised to 245-plus-255 ℃;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt with the viscosity of 0.86DL/g, and carrying out granulation and drying to obtain the polyester chip.

Embodiment 5, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 230-240 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1.05; the molar ratio of the mixture to ethylene glycol is 1:11.5, the molar ratio of ethylene glycol to phthalic acid is 1.05: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol for reaction after the materials are added, wherein the temperature of esterification reaction is 240-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.3: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:1.9, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 2.8%, 0.15% and 0.9% of the mixed molten slurry.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt with the viscosity of 0.87DL/g, and carrying out granulation and drying to obtain the polyester chip.

Embodiment 6, a method for synthesizing polyester chip for high temperature resistant film, comprising the following steps:

s1, esterification: adding a mixture of sodium 2-naphthoxyacetate and 2-naphthoxyacetic acid into an ethylene glycol solution, adding phthalic acid, transferring the mixed slurry to an esterification reaction kettle, wherein the temperature of the esterification reaction is 230-240 ℃, and preparing mixed slurry of BHET and a derivative intermediate thereof, wherein the molar ratio of the sodium 2-naphthoxyacetate to the 2-naphthoxyacetic acid is 1: 1.05; the molar ratio of the mixture to ethylene glycol was 1:12, the molar ratio of ethylene glycol to phthalic acid was 1.05: 1.

s2, diester reaction: adding polybutylene terephthalate, a compound catalyst, a UV monomer and an antioxidant into a diesterification reaction kettle, adding ethylene glycol and 3-pentanol for reaction after the materials are added, wherein the temperature of esterification reaction is 240-250 ℃ to obtain mixed molten slurry, and the molar ratio of the ethylene glycol to the 3-pentanol is 1.4: 1, the compound catalyst is ethylene glycol antimony, antimony trioxide and butyl titanate, and the mass ratio of the ethylene glycol antimony to the antimony trioxide to the butyl titanate is 1: 1:2.0, wherein the antioxidant is triphenyl phosphate, the UV monomer is acrylic resin, and the mass of the compound catalyst, the antioxidant and the UV monomer respectively accounts for 2.5%, 0.1% and 1.0% of the mixed molten slurry.

S3, mixing: when the temperature of the slurry in the step S2 is stabilized to 235-plus-245 ℃, pressing the slurry obtained in the step S1 into a double esterification kettle, stirring and mixing at a high speed for 2.0h in a nitrogen atmosphere, wherein the mass of the polybutylene terephthalate accounts for 15% of the total mass of the mixed solution, and pressing the mixed solution into a polycondensation reaction kettle from the double esterification kettle through a filter after the temperature of the mixed solution is raised to 245-plus-255 ℃;

s4, polycondensation granulation: and after the mixed slurry enters a polycondensation kettle, carrying out negative compression polymerization reaction at the final temperature of 250-260 ℃ with the vacuum degree not more than 30Pa to synthesize high-viscosity polyester chip melt, wherein the viscosity of the high-viscosity polyester chip melt is 0.9DL/g, and carrying out granulation and drying to obtain the polyester chip.

Comparative example 1: different from example 6 in that no sodium 2-naphthoxyacetate and no 2-naphthoxyacetic acid mixture were added, the molar ratio of ethylene glycol to phthalic acid was 1.1: 1, the other preparation methods, the raw material component ratios and the reaction parameters were the same as in example 6.

Comparative example 2: the difference from example 6 is that without addition of the 2-naphthoxyacetic acid mixture, only sodium 2-naphthoxyacetate and ethylene glycol are added in a molar ratio of 1:12, the molar ratio of the ethylene glycol to the phthalic acid is 1.05: 1, the other preparation methods, the raw material component ratios and the reaction parameters were the same as in example 6.

Comparative example 3: the preparation method, the raw material component ratio and the reaction parameters were the same as those of example 6 except that no UV monomer was added as in example 6.

Performance testing

The polyester chips of examples 1 to 6 and comparative examples 1 to 3 were tested in accordance with GB/T14190-. The results are shown in Table 1.

The Vicat softening point test was carried out on the polyester chips of examples 1 to 6 and comparative examples 1 to 3, respectively. The results are shown in Table 1.

The polyester chips of examples 1 to 6 and comparative examples 1 to 3 were melt-extruded in a twin-screw extruder at 285 ℃ and then cast into cast sheets through an extrusion die, followed by longitudinal stretching (stretching ratio of 3.0) and transverse stretching (stretching ratio of 4.5) in this order at 220 ℃ under an irradiation dose of 100kGy and setting, and finally drawn and wound to obtain films having a thickness of 0.01mm, and the results of the performance tests on the films are shown in Table 1.

TABLE 1 polyester chip and film test Performance Table

Table 1 results of performance testing

The softening temperature of the polyester chip synthesized by the method is increased from 70-80 ℃ of the common polyester chip to 95 ℃, the melting point is increased to more than 200 ℃, the occurrence of the adhesion phenomenon of the polyurethane chip during drying and spiral extrusion can be reduced, the high-temperature practical performance is good, and a good physical basis is provided for subsequent film making. The prepared film has high softening temperature, MD (MD) tensile strength and TD tensile strength, has good high-temperature resistance, and increases the mechanical property and dimensional stability of the film prepared from the polyester chip.

As can be seen from the performance parameters of the polyester chip and the film in the embodiment 6, the comparative example 1 and the comparative example 2, 2-naphthyloxy group in the sodium 2-naphthyloxy acetate and the 2-naphthyloxy acetic acid participates in the reaction, the naphthalene group has good stability, the sodium 2-naphthyloxy acetate and the 2-naphthyloxy acetic acid form a system, the uniformity of the reaction system is improved, the occurrence of side reactions is reduced, and the synergistic effect is realized, so that the high temperature resistance of the polyester chip and the film prepared from the polyester chip is improved.

As can be seen from the softening temperature and the film softening temperature of the polyester chip in the embodiment 6 and the comparative example 3, the addition of the UV monomer has no obvious effect on the improvement of the softening temperature of the polyester chip and has an obvious positive effect on the improvement of the softening temperature of the film, and the reason is that the UV monomer is not excited and remains stable before irradiation, and is excited by irradiation during film making, so that UV groups or functional chain ends are formed on the prepared film, the stability of the prepared film is improved, and the high temperature resistance of the film is further improved.

Finally, it should be understood that the above description is only exemplary of the present invention, and is not intended to limit the present invention, and that any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.