阅读说明：本技术 一种低端羧基耐水解聚酯及其制备方法和用途 (Low-end carboxyl hydrolysis-resistant polyester and preparation method and application thereof ) 是由 李春成 蒙钊 张博 王冬 孟现明 张栋 于 2018-05-29 设计创作，主要内容包括：本发明提供了一种低端羧基耐水解聚酯及其制备方法和用途。本发明所述的低端羧基耐水解聚酯是在不引入新的试剂和基团的情况下,通过加入环保高效的钛系聚酯催化剂并控制二元酸和二元醇单体的加料比制备得到的。本发明所制备的聚酯没有经封端和/或扩链处理,且其具有良好的耐水解性,所述制备方法简单,易于工业化生产。该聚酯的特性粘度为0.5～1.2dL/g,端羧基含量为2～10mmol/kg,综合性能优异,可满足光伏组件中对聚酯薄膜的性能要求,有望应用于光伏发电组件中,对提高中国光伏产品寿命,推动中国光伏产业健康、稳定发展具有重要作用。(The invention provides a low-end carboxyl hydrolysis-resistant polyester, a preparation method and application thereof. The low-end carboxyl hydrolysis-resistant polyester is prepared by adding an environment-friendly high-efficiency titanium polyester catalyst and controlling the feeding ratio of dibasic acid and a dibasic alcohol monomer under the condition of not introducing new reagents and groups. The polyester prepared by the invention is not subjected to end capping and/or chain extension treatment, has good hydrolysis resistance, and is simple in preparation method and easy for industrial production. The polyester has the intrinsic viscosity of 0.5-1.2 dL/g, the terminal carboxyl group content of 2-10 mmol/kg and excellent comprehensive performance, can meet the performance requirements of photovoltaic modules on polyester films, is expected to be applied to photovoltaic power generation modules, and has important effects on prolonging the service life of Chinese photovoltaic products and promoting the healthy and stable development of the Chinese photovoltaic industry.)

1. The low-end carboxyl hydrolysis-resistant polyester is characterized by being prepared by esterification and polycondensation reaction by using a titanium polyester catalyst and controlling the feeding ratio of dibasic acid to a dihydric alcohol monomer, wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); the content of the terminal carboxyl groups in the polyester is 2-10 mmol/kg.

2. The polyester according to claim 1, wherein said polyester has not been end capped and/or chain extended.

Preferably, the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.4-8), 1 (1.5-5) and 1 (1.6-3).

Preferably, the intrinsic viscosity of the polyester is 0.5-1.2 dL/g.

3. The polyester according to claim 1 or 2, wherein the titanium-based polyester catalyst is at least one selected from organic compounds, oxides or complexes of titanium; at least one of titanium dioxide, a silica/titanium dioxide composite, ethylene glycol titanium, tetrabutyl titanate, tetraisopropyl titanate, titanium carboxylate, and lithium titanyl oxalate is preferable.

Preferably, the dibasic acid is an aromatic dibasic acid, for example, at least one selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, 2, 6-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid, 2, 7-naphthalenedicarboxylic acid, 4 '-biphenyldicarboxylic acid and 2, 2' -biphenyldicarboxylic acid; at least one of terephthalic acid, isophthalic acid and phthalic acid is preferable.

Preferably, the diol is a short-chain aliphatic diol, such as at least one selected from the group consisting of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 2-dimethyl-1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, and 2, 3-butanediol; at least one of ethylene glycol, 1, 3-propanediol and 1, 4-butanediol is preferred.

4. A preparation method of low-end carboxyl hydrolysis-resistant polyester comprises an esterification reaction step and a polycondensation reaction step of dibasic acid and dibasic alcohol, wherein a titanium polyester catalyst is added before and/or after the esterification reaction, and the feeding molar ratio of the dibasic acid to the dibasic alcohol is 1 (1.3-10); the process does not include an end-capping step and/or a chain extension step.

5. The method according to claim 4, comprising in particular the steps of:

1) mixing dibasic acid and dihydric alcohol, and carrying out esterification reaction to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10);

2) performing polycondensation reaction on the polyester esterified substance in the step 1) to prepare low-end carboxyl hydrolysis-resistant polyester;

adding a titanium polyester catalyst into a mixed system of dibasic acid and dihydric alcohol before esterification reaction, and/or adding the titanium polyester catalyst into the mixed system of polyester esterified in the step 1) after esterification reaction;

the process does not include an end-capping step and/or a chain extension step.

6. The preparation method according to claim 4 or 5, wherein the molar ratio of the dibasic acid to the glycol is 1 (1.6-3).

Preferably, the addition amount of the titanium polyester catalyst is 10 of the mass of the polyester^-7wt% -0.1 wt%; preferably 10^{- 4}wt％～0.1wt％。

7. The process according to any one of claims 4 to 6, wherein the esterification reaction in step 1) is carried out under pressure.

Preferably, the pressure of the esterification reaction in the step 1) is 10 to 500KPa, the temperature of the esterification reaction is 150 to 260 ℃, and the time of the esterification reaction is 0.5 to 4 hours.

Preferably, the pressure of the esterification reaction in the step 1) is 250 to 500KPa, the temperature of the esterification reaction is 200 to 250 ℃, and the time of the esterification reaction is 1.5 to 3.5 hours.

Preferably, the polycondensation reaction of step 2) is carried out under a certain degree of vacuum.

Preferably, the vacuum degree of the polycondensation reaction in the step 2) is 10-200 Pa, the temperature of the polycondensation reaction is 250-290 ℃, and the time of the polycondensation reaction is 0.5-4 hours.

8. The method for preparing according to any one of claims 4 to 7, characterized in that it comprises the steps of:

a) mixing dibasic acid and dihydric alcohol, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); mixing a titanium polyester catalyst and a polyester ester, and carrying out polycondensation reaction under certain vacuum to prepare low-end carboxyl hydrolysis-resistant polyester; alternatively, the first and second electrodes may be,

b) mixing dibasic acid, dihydric alcohol and a titanium polyester catalyst, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); under a certain vacuum, performing polycondensation reaction on polyester esterification to prepare low-end carboxyl hydrolysis-resistant polyester; alternatively, the first and second electrodes may be,

c) mixing dibasic acid, dihydric alcohol and a titanium polyester catalyst, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); mixing a titanium polyester catalyst and a polyester ester, and carrying out polycondensation reaction under certain vacuum to prepare the low-end carboxyl hydrolysis-resistant polyester.

9. A low carboxyl hydrolysis resistant polyester prepared by the method of any one of claims 4 to 8.

10. Use of the low end carboxyl hydrolysis resistant polyester of claims 1 to 3 or claim 9 in the field of photovoltaic modules.

Preferably, the polyester is applied in the field of photovoltaic modules in the form of films or other articles.

Technical Field

The invention belongs to the technical field of polyester and preparation thereof, and particularly relates to low-end carboxyl hydrolysis-resistant polyester and a preparation method and application thereof.

Background

Under the great trend of global low-carbon economy and new energy revolution, compared with hydroelectric power, wind power, nuclear power and the like, the solar power generation has the obvious advantages of zero emission, no noise and mature application technology. Photovoltaic power generation without any fuel except sunshine is one of strategic emerging industries and is expected to become the leading energy with the largest future share in China.

Polyester, one of the five engineering plastics, has the characteristics of low price, excellent wear resistance, heat resistance, chemical resistance, electrical insulation, high mechanical strength and the like, and can be widely applied to photovoltaic back plates in photovoltaic modules. Because the photovoltaic module needs to be used outdoors for a long time, although the dry heat aging performance of the conventional polyester film is good, the hydrolysis resistance is poor, and the photovoltaic module is easy to degrade and lose efficiency under the damp and hot conditions, so that the requirement on the service life of the photovoltaic module cannot be met. Therefore, the development of a novel hydrolysis-resistant polyester material is an urgent need for the application of the polyester material in the fields of photovoltaic modules and the like.

Chinese patent document CN103665788B discloses the preparation of high viscosity modified PET copolyester by adding oxazoline compound and hydroxyl chain extender. The method can improve the viscosity and the melt strength of the PET copolyester, reduce the content of terminal carboxyl groups and improve the hot water resistance. However, the introduction of new substances destroys the ordered long-chain structure of PET, so that the structural performance of the film is unstable.

Chinese patent document CN101215730A discloses a method of adding a hydrolysis resistant agent, namely carbodiimide, to modify polyester. Although the hydrolysis resistance of the modified polyester obtained by the method is improved, the production cost is high, and a large amount of harmful volatile matters are generated in the production process, so that the influence on the environment and the health of personnel is caused.

Chinese patent document CN102344654B provides a hydrolysis-resistant PET composite material and a preparation method thereof, in the method, a mixed raw material obtained by uniformly mixing PET resin, a hydrolysis-resistant agent, a chain extender, a heat stabilizer, a nucleating agent and an auxiliary agent is placed in a double-screw extruder to be blended with glass fiber, and the hydrolysis-resistant PET composite material is obtained through melt extrusion and granulation. Although the composite material obtained by the method has better hydrolysis resistance, the complicated production procedure can cause the increase of the industrial production cost.

The improvement of the performance parameters of the polyester disclosed above is mainly realized by introducing other additives such as hydrolysis resistance agents, chain extenders, heat stabilizers, nucleating agents and the like or compounding various additives, and the polyester does not have a low-end carboxyl group in the structure; it would be of great research interest to develop a polyester with low carboxyl end group properties by itself, without end capping and without the introduction of other adjuvants.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a novel low-end carboxyl hydrolysis-resistant polyester, and a preparation method and application thereof. Under a certain reaction condition, a novel low-end carboxyl hydrolysis-resistant polyester is prepared by directly polymerizing by using an environment-friendly high-efficiency titanium polyester catalyst and controlling the feeding proportion of dibasic acid and a dibasic alcohol monomer, wherein the polyester has no end capping and/or chain extension treatment, and the structure of the polyester has the characteristic of low-end carboxyl.

The low-end carboxyl group in the invention means that the content of the low-end carboxyl group in the polyester is 2-10 mmol/kg.

The purpose of the invention is realized by the following technical scheme:

a low-end carboxyl hydrolysis-resistant polyester is prepared by using a titanium polyester catalyst and controlling the feeding ratio of dibasic acid and a dihydric alcohol monomer to carry out esterification and polycondensation, wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); the content of the terminal carboxyl groups in the polyester is 2-10 mmol/kg.

In the present invention, the polyester is not subjected to end capping and/or chain extension treatment.

According to the invention, the molar ratio of the dibasic acid to the dihydric alcohol is controlled, and the environment-friendly and efficient titanium polyester catalyst is matched, so that the amount of the terminal carboxyl is effectively reduced, and the low-end carboxyl hydrolysis-resistant polyester is obtained.

Preferably, the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.4-8), still preferably 1 (1.5-5), and further preferably 1 (1.6-3).

According to an embodiment of the present invention, the intrinsic viscosity of the polyester is 0.5 to 1.2 dL/g.

According to an embodiment of the present invention, the dibasic acid is an aromatic dibasic acid, for example, at least one selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, terephthallic acid, isophthalic acid, orthophthalic acid, 2, 6-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid, 2, 7-naphthalenedicarboxylic acid, 4 '-biphenyldicarboxylic acid, and 2, 2' -biphenyldicarboxylic acid; at least one of terephthalic acid, isophthalic acid and phthalic acid is preferable.

According to an embodiment of the present invention, the diol is a short-chain aliphatic diol, for example, at least one selected from the group consisting of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 2-dimethyl-1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, and 2, 3-butanediol; at least one of ethylene glycol, 1, 3-propanediol and 1, 4-butanediol is preferred.

According to the embodiment of the invention, the titanium polyester catalyst is selected from at least one of organic compounds, oxides or complexes of titanium; at least one of titanium dioxide, a silica/titanium dioxide composite, ethylene glycol titanium, tetrabutyl titanate, tetraisopropyl titanate, titanium carboxylate, and lithium titanyl oxalate is preferable.

The invention also provides a preparation method of the low-end carboxyl hydrolysis-resistant polyester, which comprises an esterification reaction step and a polycondensation reaction step of dibasic acid and dibasic alcohol, wherein a titanium polyester catalyst is added before and/or after the esterification reaction, and the feeding molar ratio of the dibasic acid to the dibasic alcohol is 1 (1.3-10); the process does not include an end-capping step and/or a chain extension step.

According to the invention, the method comprises the following steps:

1) mixing dibasic acid and dihydric alcohol, and carrying out esterification reaction to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10);

2) performing polycondensation reaction on the polyester esterified substance in the step 1) to prepare low-end carboxyl hydrolysis-resistant polyester;

adding a titanium polyester catalyst into a mixed system of dibasic acid and dihydric alcohol before esterification reaction, and/or adding the titanium polyester catalyst into the mixed system of polyester esterified in the step 1) after esterification reaction;

the process does not include an end-capping step and/or a chain extension step.

According to the embodiment of the invention, the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.4-8), preferably 1 (1.5-5), and further preferably 1 (1.6-3).

According to an embodiment of the present invention, the dibasic acid is an aromatic dibasic acid, for example, at least one selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, terephthallic acid, isophthalic acid, orthophthalic acid, 2, 6-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid, 2, 7-naphthalenedicarboxylic acid, 4 '-biphenyldicarboxylic acid, and 2, 2' -biphenyldicarboxylic acid; at least one of terephthalic acid, isophthalic acid and phthalic acid is preferable.

According to an embodiment of the present invention, the diol is a short-chain aliphatic diol, for example, at least one selected from the group consisting of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 2-dimethyl-1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, and 2, 3-butanediol; at least one of ethylene glycol, 1, 3-propanediol and 1, 4-butanediol is preferred.

According to an embodiment of the present invention, the titanium-based polyester catalystThe adding amount is 10 of the mass of the polyester^-7wt% -0.1 wt%; preferably 10^-4wt％～0.1wt％。

According to the embodiment of the invention, the titanium polyester catalyst is selected from at least one of organic compounds, oxides or complexes of titanium; at least one of titanium dioxide, a silica/titanium dioxide composite, ethylene glycol titanium, tetrabutyl titanate, tetraisopropyl titanate, titanium carboxylate, and lithium titanyl oxalate is preferable.

According to an embodiment of the present invention, the esterification reaction of step 1) is carried out under pressure.

According to the embodiment of the invention, the pressure of the esterification reaction in the step 1) is 10-500 KPa, the temperature of the esterification reaction is 150-260 ℃, and the time of the esterification reaction is 0.5-4 hours.

Preferably, the pressure of the esterification reaction in the step 1) is 250 to 500KPa, the temperature of the esterification reaction is 200 to 250 ℃, and the time of the esterification reaction is 1.5 to 3.5 hours.

According to an embodiment of the present invention, the polycondensation reaction of step 2) is performed under a certain degree of vacuum.

According to the embodiment of the invention, the vacuum degree of the polycondensation reaction in the step 2) is 10-200 Pa, the temperature of the polycondensation reaction is 250-290 ℃, and the time of the polycondensation reaction is 0.5-4 hours.

According to an embodiment of the invention, the method comprises the steps of:

a) mixing dibasic acid and dihydric alcohol, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); mixing a titanium polyester catalyst and a polyester ester, and carrying out polycondensation reaction under certain vacuum to prepare low-end carboxyl hydrolysis-resistant polyester; alternatively, the first and second electrodes may be,

b) mixing dibasic acid, dihydric alcohol and a titanium polyester catalyst, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); under a certain vacuum, performing polycondensation reaction on polyester esterification to prepare low-end carboxyl hydrolysis-resistant polyester; alternatively, the first and second electrodes may be,

c) mixing dibasic acid, dihydric alcohol and a titanium polyester catalyst, and carrying out esterification reaction under certain pressure to prepare a polyester esterified substance; wherein the feeding molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.3-10); mixing a titanium polyester catalyst and a polyester ester, and carrying out polycondensation reaction under certain vacuum to prepare the low-end carboxyl hydrolysis-resistant polyester.

The low-end carboxyl hydrolysis-resistant polyester is prepared by the method for preparing the low-end carboxyl hydrolysis-resistant polyester.

The invention also provides application of the low-end carboxyl hydrolysis-resistant polyester, which is applied to the fields of photovoltaic modules and the like.

Preferably, the polyester is applied to the fields of photovoltaic modules and the like in the form of films or other products.

The invention has the beneficial effects that:

the invention provides a low-end carboxyl hydrolysis-resistant polyester, a preparation method and application thereof. The low-end carboxyl hydrolysis-resistant polyester is prepared by controlling the feeding ratio of dibasic acid and dihydric alcohol monomer (the research finds that the feeding ratio can be controlled within the range of 1 (1.3-10)) and adding an environment-friendly and efficient titanium polyester catalyst under the condition of not introducing new reagents and groups. The polyester prepared by the invention is not subjected to end capping and/or chain extension treatment, has good hydrolysis resistance, and is simple in preparation method and easy for industrial production. The polyester has the intrinsic viscosity of 0.5-1.2 dL/g, the terminal carboxyl group content of 2-10 mmol/kg and excellent comprehensive performance, can meet the performance requirements of photovoltaic modules on polyester films, is expected to be applied to photovoltaic power generation modules, and has important effects on prolonging the service life of Chinese photovoltaic products and promoting the healthy and stable development of the Chinese photovoltaic industry.

Detailed Description

The preparation method of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.

The terminal carboxyl group content and intrinsic viscosity in the following examples were measured in accordance with GB/T14190-20085.4.2 method B and GB/T14190-20085.1.1 method A (solvent 5.1.1.3.1), respectively.