阅读说明：本技术 一种高透低雾光学基膜用聚酯母料的合成方法 (Synthesis method of polyester master batch for high-transmittance low-fog optical base 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：本发明涉及聚酯母粒技术领域,尤其是一种高透低雾光学基膜用聚酯母料的合成方法,包括以下步骤：1)将100份对苯二甲酸、130份乙二醇和0.001-0.002份醋酸钠配制成浆料,然后转移至酯化反应釜中进行酯化反应,然后加入0.02-0.05份乙醇锑和对甲苯磺酸的复合催化剂、10-20份第三单体依次进行预缩聚反应和终缩聚反应,在终缩聚反应阶段加入0.001-0.002份磷酸三甲酯,2)终缩聚结束降温过程中加入光固化单体和光引发剂,最后将终聚物卸到冷却池,切片得到聚酯母料；本发明中的聚酯母料在后续制备光学基膜的时候,可以通过辐照步骤提高光学基膜的硬度,从而可以降低抗粘连剂的添加,从而降低光学基膜的折射率,得到高透光低雾度的光学基膜。(The invention relates to the technical field of polyester master batches, in particular to a method for synthesizing a polyester master batch for a high-transparency low-fog optical base film, which comprises the following steps: 1) preparing 100 parts of terephthalic acid, 130 parts of ethylene glycol and 0.001-0.002 part of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.02-0.05 part of composite catalyst of ethanol antimony and p-toluenesulfonic acid and 10-20 parts of third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.001-0.002 part of trimethyl phosphate in the final polycondensation reaction stage, 2) adding a photocuring monomer and a photoinitiator in the final polycondensation bundle cooling process, finally unloading the final polymer into a cooling tank, and slicing to obtain a polyester master batch; when the polyester master batch is used for preparing the optical base film subsequently, the hardness of the optical base film can be improved through the irradiation step, so that the addition of the anti-blocking agent can be reduced, the refractive index of the optical base film is reduced, and the optical base film with high light transmittance and low haze is obtained.)

1. A synthetic method of polyester master batch for a high-transmittance low-fog optical base film is characterized by comprising the following steps: the synthesis method comprises the following steps:

1) preparing 100 parts of terephthalic acid, 130 parts of ethylene glycol and 0.001-0.002 part of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.02-0.05 part of composite catalyst of ethanol antimony and p-toluenesulfonic acid and 10-20 parts of third monomer for pre-polycondensation reaction and final polycondensation reaction in turn, adding 0.001-0.002 part of trimethyl phosphate in the final polycondensation reaction stage,

2) and adding the photocuring monomer and the photoinitiator in the final condensation coalescence beam cooling process, finally unloading the final polymer into a cooling tank, slicing to obtain the polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator.

2. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the light-cured monomer is one or more of bisphenol A epoxy acrylate, phenolic epoxy acrylate, modified epoxy acrylate, epoxidized oil acrylate and methacrylic acid-beta-hydroxyethyl.

3. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 2-5% of the mass of the monomer.

4. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the mass ratio of the ethanol antimony to the p-toluenesulfonic acid of the composite catalyst is 1.5-1.8: 1.

5. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1.

6. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the reaction temperature of the pre-polycondensation is 245-265 ℃, the reaction pressure is 1100-1200Pa, and the pre-polycondensation time is 30-40 min.

7. The method for synthesizing the polyester master batch for the high-transmittance low-fog optical base film as claimed in claim 1, wherein the method comprises the following steps: the vacuum degree of the final polycondensation reaction is lower than 110-120Pa, the temperature is 270-285 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g.

Technical Field

The invention relates to the technical field of polyester master batches, in particular to a synthetic method of a polyester master batch for a high-transparency low-fog optical base film.

Background

Mylar has higher requirements in optical applications than in packaging or electronics stores, in addition to mechanical strength. In terms of thermal stability, etc., more excellent optical properties are also required, and the main indicators thereof are light transmittance and haze value. Haze values for typical 12 μm mylar used for packaging are controlled below 3%, and haze values for 188 μm optical grade mylar are required to be controlled below 1%.

The haze value of the polyester film is influenced by the following factors:

(ii) influence of additives. The particle size, distribution, type and amount of the additive have a great influence on the haze value. The additives actually act only on the surface layer, so multilayer coextrusion can be employed in the apparatus configuration to eliminate the effect of the film internal additives on haze.

② influence of process conditions. The crystallinity of polyester films greatly affects haze values, and the crystal form and crystallinity are constantly changing during the processing of polyester films, which requires strict control. Therefore, the equipment configuration of the production line is required to satisfy the requirement of controlling the crystallinity. The equipment requires that the cast sheet must have sufficient cooling capacity and the longitudinal stretcher must be able to reach higher preheating temperatures without sticking to the rolls. All the rollers are driven individually and the horizontal stretcher has enough heat setting length.

Influence of raw materials. There are several main aspects: the content of internal impurities including the residual amount of the catalyst; second is the hue of the material; and thirdly, the stability of the material. The production of high-grade films abroad usually requires the use of raw materials of a given brand.

In the production of the existing polyester film, in order to meet the requirement of processability, the polyester surface layer must contain a small amount of fine solid particles to play the anti-blocking role of the winding and unwinding of the film. The inorganic ions are generally silicon dioxide, calcium phosphate, kaolin, etc., the particle diameter is generally between 1 and 6 μm, and the conventional method is to add inorganic particles into polyester raw materials to prepare master batch slices, and then add the inorganic particles into the whole film by master batch adding. The addition of these inorganic particles solves the problem of blocking resistance of the film surface, but inevitably reduces the optical properties of the film. On the one hand, the inorganic particles block part of the light to reduce the light transmittance, and on the other hand, the fine particles shift part of the light from the original direction to increase the haze. Although the optical properties can be improved by reducing the amount of inorganic particles added, the effect is not satisfactory and the processability of the film is significantly reduced.

Disclosure of Invention

The purpose of the invention is: the polyester master batch for the optical base film prepared by adding the synthesis method into the polyester film can improve the high-haze and low-haze property of the optical base film, thereby obviously improving the processing performance of the film.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows:

a synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 parts of terephthalic acid, 130 parts of ethylene glycol and 0.001-0.002 part of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.02-0.05 part of composite catalyst of ethanol antimony and p-toluenesulfonic acid and 10-20 parts of third monomer for pre-polycondensation reaction and final polycondensation reaction in turn, adding 0.001-0.002 part of trimethyl phosphate in the final polycondensation reaction stage,

2) and adding the photocuring monomer and the photoinitiator in the final condensation coalescence beam cooling process, finally unloading the final polymer into a cooling tank, slicing to obtain the polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator.

Further, the light-cured monomer is one or more of bisphenol A epoxy acrylate, phenolic epoxy acrylate, modified epoxy acrylate, epoxidized oil acrylate and methacrylic acid-beta-hydroxyethyl ester.

Further, the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 2-5% of the mass of the monomer.

Furthermore, the mass ratio of the ethanol antimony to the p-toluenesulfonic acid is 1.5-1.8: 1.

Further, the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the mixture to the isophthalic acid is 1: 1.

Further, the reaction temperature of the pre-polycondensation is 245-265 ℃, the reaction pressure is 1100-1200Pa, and the pre-polycondensation time is 30-40 min.

Further, the vacuum degree of the final polycondensation reaction is lower than 110-120Pa, the temperature is 270-285 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g.

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

according to the invention, the photocuring monomer and the photoinitiator are added in the final condensation coalescence beam cooling process, finally the final polymer is unloaded to a cooling pool, and sliced to obtain the polyester master batch, and the polyester master batch is added when the temperature is reduced to be below the melting point of the photocuring monomer and the photoinitiator, and the photocuring monomer and the photoinitiator are added, so that the hardness of the optical base film can be improved through an irradiation step in the subsequent preparation of the optical base film, and thus the addition of an anti-adhesion agent (silicon dioxide, calcium phosphate, kaolin or organic silicon polymer) can be reduced, the refractive index of the optical base film is reduced, and the optical base film with low haze is obtained. After the refractive index is further lowered, the light transmittance of the optical base film can be improved.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

The sources of the raw materials in the invention are:

terephthalic acid: industrial grade, certified chemical fiber limited;

ethylene glycol: industrial grade, chemical reagents ltd of the national drug group.

Cobalt acetate: shanghai Huating chemical plant, Inc.;

nano antimony trioxide: cinese antimony, Inc.;

in the present invention, the raw materials are all commercially available without specific description.

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 parts of terephthalic acid, 130 parts of ethylene glycol and 0.001-0.002 part of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.02-0.05 part of composite catalyst of ethanol antimony and p-toluenesulfonic acid and 10-20 parts of third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.001-0.002 part of trimethyl phosphate at the final polycondensation reaction stage, taking the sodium acetate as an ether inhibitor, reducing the synthesis of ether by-products, and inhibiting the generation of cyclic trimer by the trimethyl phosphate, thereby reducing the generation of oligomers and improving the quality of the optical base film prepared subsequently;

the reaction temperature of the pre-polycondensation in the step is 245-265 ℃, the reaction pressure is 1100-1200Pa, and the pre-polycondensation time is 30-40 min; the vacuum degree of the final polycondensation reaction in the step is lower than 110-120Pa, the temperature is 270-285 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.618 dl/g;

the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid in the step is 1.5-1.8: 1;

the third monomer in the step is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

2) adding a photocuring monomer and a photoinitiator in the final condensation and coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, adding the polyester master batch when the temperature is reduced to be below the melting point of the photocuring monomer and the photoinitiator, adding the photocuring monomer and the photoinitiator, and improving the hardness of the optical base film through an irradiation step when preparing the optical base film subsequently, so that the addition of an anti-adhesion agent (silicon dioxide, calcium phosphate, kaolin or organic silicon polymer) can be reduced, the refractive index of the optical base film is reduced, and the optical base film with low haze is obtained. After the refractive index is further lowered, the light transmittance of the optical base film can be improved.

The photo-curing monomer in the step is one or more of bisphenol A epoxy acrylate, phenolic epoxy acrylate, modified epoxy acrylate, epoxidized oil acrylate and beta-hydroxyethyl methacrylate, preferably a mixture of the epoxidized oil acrylate and the beta-hydroxyethyl methacrylate, and the molar ratio of the mixture to the beta-hydroxyethyl methacrylate is 1: 1.

The photoinitiator in the step is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 2-5% of the mass of the monomer.

Example 1

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.001 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.02 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 10 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in turn, adding 0.001 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.5: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the polycondensation reaction temperature is 245 ℃, the reaction pressure is 1200Pa, and the precondensation time is 40 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 120Pa, the temperature is 270 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein, the light-cured monomer is bisphenol A epoxy acrylate;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 2-5% of the mass of the monomer.

Example 2

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.0015 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.03 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 15 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.001 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.5: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the polycondensation reaction temperature is 24 ℃, the reaction pressure is 1200Pa, and the precondensation time is 40 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 120Pa, the temperature is 270 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein the light-cured monomer is phenolic epoxy acrylate;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 2.5 percent of the mass of the monomer.

Example 3

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.0015 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.04 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 15 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.0015 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.6: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the reaction temperature of polycondensation is 255 ℃, the reaction pressure is 1150Pa, and the precondensation time is 40 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 115Pa, the temperature is 280 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein the photocuring monomer is a mixture of epoxidized oil acrylate and beta-hydroxyethyl methacrylate, and the molar ratio of the epoxidized oil acrylate to the beta-hydroxyethyl methacrylate is 1: 1;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 4% of the mass of the monomer.

Example 4

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.0018 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.04 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 15 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.0015 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.6: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the reaction temperature of polycondensation is 255 ℃, the reaction pressure is 1150Pa, and the precondensation time is 40 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 115Pa, the temperature is 280 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein the photocuring monomer is a mixture of epoxidized oil acrylate and beta-hydroxyethyl methacrylate, and the molar ratio of the epoxidized oil acrylate to the beta-hydroxyethyl methacrylate is 1: 1;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 4% of the mass of the monomer.

Example 5

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.002 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.05 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 15 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.002 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.6: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the polycondensation reaction temperature is 260 ℃, the reaction pressure is 1150Pa, and the precondensation time is 40 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 115Pa, the temperature is 280 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein the photocuring monomer is a mixture of epoxidized oil acrylate and beta-hydroxyethyl methacrylate, and the molar ratio of the epoxidized oil acrylate to the beta-hydroxyethyl methacrylate is 1: 1;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 4% of the mass of the monomer.

Example 6

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.002 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.05 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 20 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.002 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.8: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the polycondensation reaction temperature is 265 ℃, the reaction pressure is 1100Pa, and the precondensation time is 30 min;

wherein, the vacuum degree of the final polycondensation reaction is lower than 110Pa, the temperature is 285 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g;

2) adding a photocuring monomer and a photoinitiator in the final condensation coalescence beam cooling process, finally unloading a final polymer into a cooling tank, slicing to obtain a polyester master batch, and adding the polyester master batch when the temperature is reduced to be below the melting points of the photocuring monomer and the photoinitiator;

wherein the photocuring monomer is a mixture of epoxidized oil acrylate and beta-hydroxyethyl methacrylate, and the molar ratio of the epoxidized oil acrylate to the beta-hydroxyethyl methacrylate is 1: 1;

wherein the photoinitiator is benzoin dimethyl ether, and the addition amount of the benzoin dimethyl ether is 5% of the mass of the monomer.

Comparative example 1

A synthetic method of a polyester master batch for a high-transmittance low-fog optical base film comprises the following steps:

1) preparing 100 mol of terephthalic acid, 130 mol of ethylene glycol and 0.0015 mol of sodium acetate into slurry, transferring the slurry into an esterification reaction kettle for esterification reaction, then adding 0.04 mol of a composite catalyst of ethanol antimony and p-toluenesulfonic acid and 15 mol of a third monomer for pre-polycondensation reaction and final polycondensation reaction in sequence, adding 0.0015 mol of trimethyl phosphate in the final polycondensation reaction stage,

wherein the mass ratio of the composite catalyst ethanol antimony to the p-toluenesulfonic acid is 1.6: 1;

wherein the third monomer is a mixture of phthalic acid and isophthalic acid, and the molar ratio of the phthalic acid to the isophthalic acid is 1: 1;

wherein the reaction temperature of polycondensation is 255 ℃, the reaction pressure is 1150Pa, and the precondensation time is 40 min;

wherein the vacuum degree of the final polycondensation reaction is lower than 115Pa, the temperature is 280 ℃, the stirring speed is gradually reduced along with the increase of the viscosity, and the reaction is stopped when the intrinsic viscosity reaches 0.608 dl/g.

Preparing an optical base film with the thickness of 0.25mm from the polyester master batch prepared in the examples 1-6, mixing and drying 10% of polyester master batch, 0.1% of nano-silica and 89.9% of optical grade polyester chip, transferring the mixture into a main machine, melting the mixture by an extruder at the melting temperature of 275-280 ℃, filtering the mixture by a filter with the filtering precision of 12 microns, and then co-extruding and stretching the mixture with other auxiliary machines to obtain the optical base film with three film layers, wherein the total thickness of the optical base film is 0.25mm, the first film layer is a film layer with the thickness of 0.2mm and added with the polyester master batch, and the second and third film layers are respectively a film layer with the thickness of 0.025mm and the content of 100% of optical polyester chip. Before rolling, irradiation treatment is carried out on the optical base film by adopting irradiation equipment, a high-pressure UV curing lamp (mercury lamp) is adopted for irradiation treatment, the wave band of a light source of irradiation is 365nm, and the power of the mercury lamp is 100 w/cm.

And the polyester master batch prepared in the comparative example 1 is used for preparing the optical base film with the same thickness by the same method.

Comparative example 2 is a prior art optical base film to which 0.3% of nano silica is added.

Table 1 shows the product performance and effect data of the above examples and comparative examples.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.