CN113583282B

CN113583282B - Antistatic optical film, preparation method thereof and display panel

Info

Publication number: CN113583282B
Application number: CN202111066756.2A
Authority: CN
Inventors: 李良彬; 孟令蒲; 张文文; 王道亮
Original assignee: Institute of Advanced Technology University of Science and Technology of China
Current assignee: Institute of Advanced Technology University of Science and Technology of China
Priority date: 2021-09-10
Filing date: 2021-09-10
Publication date: 2023-01-17
Anticipated expiration: 2041-09-10
Also published as: CN113583282A

Abstract

The invention discloses an antistatic optical film, a preparation method thereof and a display panel, wherein the antistatic optical film comprises a polyester base layer, at least one side of the polyester base layer is provided with an antistatic layer, the antistatic layer is formed by crosslinking a plurality of crosslinking bodies, and an antistatic material A is dispersed in the antistatic layer; wherein the plurality of crosslinks includes a first crosslink, a second crosslink, and an antistatic material B. According to the invention, the antistatic layer not only has uniform and strong antistatic performance, but also still has the antistatic performance under a low-temperature and low-humidity environment based on the arrangement of a network structure; in addition, the invention adopts two antistatic materials, one of which participates in the three-dimensional network structure, so that the antistatic performance of each part of the optical film is balanced and stable, and the other one is dispersed in the network structure, so that the antistatic performance of the optical film is improved, and meanwhile, the using amount of the antistatic material B is reduced, thereby effectively controlling the raw material cost of the optical film and reducing the processing difficulty.

Description

Antistatic optical film, preparation method thereof and display panel

Technical Field

The invention relates to the technical field of new optical display materials, in particular to an antistatic optical film, a preparation method thereof and a display panel.

Background

From the coating of glasses to display panels such as mobile phones, televisions, computers, vehicle-mounted display screens, and the like, optical films are ubiquitous. Among them, polyester films are widely used in display modules, film packaging protection, and the like because of their excellent heat resistance, dimensional stability, and optical properties.

However, the polyester film substrate has a large surface resistance and poor antistatic property, and an optical film made of a polyester material is likely to adsorb dust and impurities during use, and is also likely to generate charges on the film surface, thereby causing electrostatic discharge. If the film generates electrostatic discharge in the use or storage process of the display assembly, the circuit is easy to be damaged, and the display product is damaged. If the film discharges during packaging and transportation, fire and the like may be induced, and therefore, it is very necessary to impart an antistatic function to the polyester optical film.

On the other hand, the harsh conditions that the display panel needs to experience during use or transportation present challenges to the antistatic performance of the display film assembly. For example, in winter, especially in northern China, the temperature is low and the relative humidity of air is also low, and the condition can easily generate static electricity. Such as vehicle mounted displays, outdoor advertising displays, outdoor use of mobile phones, etc., are all severely affected. Therefore, imparting antistatic retentivity to a polyester optical film at low temperature and low humidity is one of the essential measures for widening the application conditions of products such as a polyester optical film or a display panel.

It is known from the known knowledge that the improvement of the antistatic property of the film is to improve the conductivity of the inside or the surface of the film, namely to reduce the resistance of the inside or the surface of the film through various strategies, so that the charges accumulated in the film can be quickly dissipated, and the purposes of no aggregation and no discharge are achieved. At present, the commonly used methods include: (1) For example, chinese patent CN112029128a discloses an antistatic polyester film with a polythiophene-containing hybrid acrylic coating, and CN107502122B discloses a method for preparing a polyester film using a polythiophene-containing modified acrylic coating, but in the above method, a large amount of organic solvents such as ethanol or isopropyl alcohol are required for preparing the coating, which is not favorable for environmental protection. On the other hand, the above method still has a problem that the antistatic function is deteriorated at low temperature and low humidity. (2) In the other scheme, the antistatic agent and the resin are blended to prepare a blended film, the film has permanent antistatic performance, but the method needs to add a large amount of the antistatic agent, and once the addition amount of the antistatic agent is increased, the content of other components is redesigned to ensure the comprehensive performance of the optical film, so that the processing difficulty is high, and the manufacturing cost is high. Therefore, developing a polyester film with low cost, simple preparation process and stable antistatic performance is one of the most important research directions in the current optical film industry.

Disclosure of Invention

The invention mainly aims to provide an antistatic optical film, a preparation method thereof and a display panel, and aims to solve the problem that the existing antistatic optical film is poor in retentivity in a low-temperature and low-humidity environment.

In order to achieve the purpose, the invention provides an antistatic optical film, which comprises a polyester base layer, wherein at least one side of the polyester base layer is provided with an antistatic layer, the antistatic layer is formed by crosslinking a plurality of crosslinking bodies, and an antistatic material A is dispersed in the antistatic layer;

wherein the plurality of crosslinks includes a first crosslink, a second crosslink, and an antistatic material B.

Optionally, the thickness of the antistatic layer is 0.1 to 1.2 μm; and/or the presence of a gas in the atmosphere,

the surface resistance of the antistatic layer on the side departing from the polyester base layer is less than 5 multiplied by 10 ¹⁰ Ω/m ² 。

Optionally, the first crosslinker comprises a copolyester; and/or the presence of a gas in the atmosphere,

the second crosslinked material includes a water-soluble alcohol resin; and/or the presence of a gas in the gas,

the antistatic material A comprises at least one of cationic antistatic aids or at least one of anionic antistatic aids, and the antistatic material A is a non-crosslinkable material; and/or the presence of a gas in the gas,

the antistatic material B comprises a nonionic antistatic auxiliary agent, and the antistatic material B is a crosslinkable material.

Optionally, the acid value of the copolyester is 5-20 KOHmg/g; and/or the presence of a gas in the atmosphere,

the water-soluble alcohol resin has a saponification degree of 80 to 98%.

Alternatively, the copolyester is a water-dispersible copolyester having an aromatic ring structure; and/or the presence of a gas in the gas,

the second crosslinked body includes a polyvinyl alcohol resin; and/or the presence of a gas in the gas,

the antistatic material A comprises at least one of a long-chain alkyl quaternary ammonium cation antistatic auxiliary agent and a phosphonium salt cation antistatic auxiliary agent, or at least one of an alkyl sulfonate anion antistatic auxiliary agent, a phosphate anion antistatic auxiliary agent and a dithiocarbamate anion antistatic auxiliary agent; and/or the presence of a gas in the gas,

the antistatic material B comprises a polyether polyol nonionic antistatic agent.

In addition, the present invention also provides a method for preparing the antistatic optical film, which comprises the following steps:

providing a polyester substrate;

coating an antistatic liquid on the surface of the polyester base layer after the polyester base layer is subjected to heat treatment to form an antistatic coating;

carrying out heat treatment on the antistatic coating so as to enable the antistatic coating to be crosslinked and cured to form an antistatic layer;

the antistatic liquid comprises the following components in parts by weight: 20-60 parts of a first cross-linked body, 5-30 parts of a second cross-linked body, 0.1-5 parts of a cross-linking agent, 0.3-1 part of an antistatic component and 0.1-2 parts of a leveling agent, wherein the antistatic component comprises an antistatic material A and an antistatic material B.

Optionally, in the step of coating an antistatic liquid on the surface of the polyester base layer after the heat treatment of the polyester base layer to form an antistatic coating layer, the temperature is (T) _g -10～T _g + 20) ° c coating an antistatic liquid on a surface of the polyester base layer to form an antistatic coating; and/or the presence of a gas in the gas,

in the antistatic component, the weight ratio of the antistatic material A to the antistatic material B is (0.2-0.5) to 1.

Optionally, in the step of performing heat treatment on the antistatic coating to crosslink and cure the antistatic coating to form the antistatic layer, the temperature of the heat treatment is 100 to 150 ℃.

Optionally, the antistatic liquid further comprises a catalyst comprising a tertiary amine-based catalyst or an organometallic compound catalyst.

In addition, the invention also provides a display panel, which comprises an antistatic optical film, wherein the antistatic optical film comprises a polyester base layer, at least one side of the polyester base layer is provided with an antistatic layer, the antistatic layer is formed by crosslinking a plurality of crosslinking bodies, and antistatic materials A are dispersed in the antistatic layer; wherein the plurality of crosslinks includes a first crosslink, a second crosslink, and an antistatic material B.

In the technical scheme provided by the invention, the first cross-linked body, the second cross-linked body and the antistatic material B with antistatic property are cross-linked to form a three-dimensional network structure, and the antistatic material A is distributed in the three-dimensional network structure, so that the antistatic layer not only has uniform and strong antistatic property, but also still has the antistatic property in a low-temperature and low-humidity environment based on the arrangement of the network structure; in addition, the invention adopts two antistatic materials, one of which participates in the three-dimensional network structure, so that the antistatic performance of each part of the optical film is balanced and stable, and the other one is dispersed in the network structure, so that the antistatic performance of the optical film is improved, and simultaneously, the using amount of the antistatic material B is reduced, thereby effectively controlling the raw material cost of the optical film and reducing the processing difficulty.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other related drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of an antistatic optical film provided in the present disclosure;

FIG. 2 is a schematic structural view of the antistatic layer in FIG. 1;

FIG. 3 is an atomic force microscopic modulus distribution of the antistatic layer of FIG. 1;

fig. 4 is a schematic flow chart of an embodiment of a method for preparing an antistatic optical film according to the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Antistatic optical film	2	Second crosslinked material
10	Polyester substrate	3	Antistatic Material A
				20	Antistatic layer	4	Antistatic Material B
1	First crosslinked material

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. In addition, technical solutions between the various embodiments may be combined with each other, but must be based on the realization of the capability of a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The polyester film base material has large surface resistance and poor antistatic property, and an optical film made of the polyester material is easy to adsorb dust and impurities in the using process and generate charges on the surface of the film to generate electrostatic discharge. If the film generates electrostatic discharge in the use or storage process of the display assembly, the circuit is easy to be damaged, and the display product is damaged. If the film discharges during packaging and transportation, fire and the like may be induced, and therefore, it is very necessary to impart an antistatic function to the polyester optical film.

On the other hand, the harsh conditions that the display panel needs to experience during use or transportation present challenges to the antistatic performance of the display film assembly. For example, in winter, especially in northern China, the temperature is extremely low and the relative humidity of air is also low, and the condition can easily generate static electricity. Such as vehicle mounted displays, outdoor advertising displays, outdoor use of mobile phones, etc., are all severely affected. Therefore, imparting antistatic retention properties to polyester optical films at low temperatures and low humidity is one of the essential measures to broaden the application conditions of products such as polyester optical films or display panels.

At present, the commonly used methods include: (1) The surface of the film is coated with one or more conductive layers to reduce the resistance of the film, but the method has the problems that a large amount of organic solvent is used in the processing process, the environmental protection requirement is not facilitated, and in addition, the antistatic performance can not be kept permanently under the low-temperature and low-humidity environment; (2) The blending film is prepared by blending the antistatic agent and the resin, and has permanent antistatic performance, but the method needs to add a large amount of the antistatic agent, and once the addition amount of the antistatic agent is increased, the content of other components is redesigned to ensure the comprehensive performance of the optical film, so that the processing difficulty is high, and the manufacturing cost is high.

In view of this, the present invention provides a display panel, for example, a display screen of a mobile terminal such as a mobile phone and a tablet computer, a display screen of various mechanical devices or a household appliance, and the display panel includes an antistatic optical film 100, where the antistatic optical film 100 not only has strong antistatic performance, but also has good retention property in a low-temperature and low-humidity environment. Fig. 1 to 3 illustrate an embodiment of an antistatic optical film 100 according to the present invention.

Referring to fig. 1, the antistatic optical film 100 includes a polyester base layer 10, wherein an antistatic layer is disposed on at least one side of the polyester base layer 10, the antistatic layer is formed by crosslinking a plurality of crosslinked bodies, and an antistatic material A3 is dispersed in the antistatic layer; wherein the plurality of crosslinked bodies includes a first crosslinked body 1, a second crosslinked body 2, and an antistatic material B4.

According to the technical scheme provided by the invention, a three-dimensional network structure is formed by crosslinking a first crosslinked body 1, a second crosslinked body 2 and an antistatic material B4 with antistatic performance, and the antistatic material A3 is distributed in the three-dimensional network structure, so that an antistatic layer not only has uniform and strong antistatic performance, but also still has the antistatic performance under a low-temperature and low-humidity environment based on the arrangement of the network structure; in addition, the invention adopts two antistatic materials, one of which participates in the three-dimensional network structure, so that the antistatic performance of each part of the optical film is balanced and stable, and the other one is dispersed in the network structure, thereby improving the antistatic performance of the optical film and reducing the using amount of the antistatic material B4, thereby effectively controlling the raw material cost of the optical film and reducing the processing difficulty.

Specifically, the material of the polyester substrate 10 is a transparent polyester material. Further, the material of the polyester base layer 10 includes one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyarylate (PAR), polyethylene terephthalate-1,4-cyclohexanedimethanol (PCT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), 1.3 polytrimethylene terephthalate (PTT), and polytrimethylene naphthalate (PTN), or a copolymer of a plurality of the above materials, and the material selected as the material of the polyester base layer 10 can provide the antistatic optical film 100 with good mechanical properties and transparency. Further, the material of the polyester base layer 10 is preferably PET in view of the heat resistance, optical performance and cost of the antistatic optical film 100.

In the antistatic optical film 100, an antistatic layer may be disposed on only one surface of the polyester base layer 10, or an antistatic layer may be disposed on both surfaces of the polyester base layer 10. Further, on the polyester base layer 10 was equipped with the one side of antistatic layer, can only set up the antistatic layer of one deck, also can set up the antistatic layer of multilayer.

Referring to fig. 2 and 3, it can be seen that the first cross-linked body 1, the second cross-linked body 2, and the antistatic material B4 are interwoven to form a network structure (cross-linked by a cross-linking agent), the formation of the cross-linking system ensures the uniform distribution of the antistatic material B4 in the system, and also ensures the better dispersion uniformity of the antistatic material A3 in the antistatic layer, so that the antistatic properties of the antistatic optical film 100 are consistent at all places, and on the other hand, the antistatic material B4 is cross-linked with other cross-linked bodies, so that the antistatic network has higher structural stability, and the antistatic properties of the antistatic material A3 distributed in the meshes of the cross-linking network are further improved, so as to reduce the surface resistance of the film, and in addition, the phenomena of agglomeration, drift, and the like of the antistatic agent A3 are prevented by the steric hindrance limiting effect of the cross-linking network meshes on the antistatic agent A3. Therefore, the antistatic component prepared by the above strategy does not lose its original conductive properties even under external conditions of low temperature and low humidity, etc.

In some embodiments, the thickness of the antistatic layer is 0.1 μm to 1.2 μm, for example, 0.1 μm, 0.2 μm, 0.5 μm, 0.7 μm, 0.8 μm, 1.0 μm, 1.1 μm, 1.2 μm, etc., within this range, the antistatic performance can be improved to the maximum, and the network structure near the polyester base layer 10 in the formed antistatic layer is dense compared with the network structure far from the polyester base layer 10 due to component sedimentation during the curing and forming process of the antistatic layer, so that the network structure of the antistatic layer is not uniformly distributed, and the haze of the antistatic optical film 100 is further affected. Preferably, the thickness of the antistatic layer is 0.5 to 1.1 μm.

The thickness of the polyester substrate 10 may be any thickness, which is not limited in the present invention. However, in view of the usability of the antistatic optical film 100, the total thickness of the antistatic optical film 100 is preferably 30 to 300 μm, so that the antistatic optical film has good optical performance and antistatic performance, and the processing difficulty is not increased due to the thinness of the antistatic optical film, and the use experience is not affected due to the thinness of the antistatic optical film.

Furthermore, the surface resistance of the antistatic layer on the side facing away from the polyester base layer 10 is less than 5 × 10 ¹⁰ Ω/m ² . Thus, the antistatic optical film 100 can be ensured to have a better antistatic property.

The specific types of the first crosslinked body 1 and the second crosslinked body 2 are not limited in the present invention, and it is only necessary that a plurality of crosslinked bodies can be crosslinked to form a stable three-dimensional network structure.

In some embodiments, the first crosslinked body 1 includes a copolyester, i.e., a copolymer formed by esterification, polycondensation, etc. of a polyol and a polyacid; further, the first crosslinked material 1 is preferably a copolyester having a structure similar to that of the polyester base layer 10, for example, a copolyester having an aromatic ring structure in a main chain or a side group, so that the adhesion between the antistatic layer and the polyester base layer 10 can be improved, the two can be tightly bonded, and the antistatic layer can be prevented from falling off from the base layer. The first cross-linked material 1 is preferably a material having water solubility or water dispersion property, and compared with other materials, the water-soluble coating liquid is more environment-friendly, and Volatile Organic Compounds (VOCs) are not or hardly discharged in the production process. Specifically, in this embodiment, the copolyester is a water-dispersible copolyester having an aromatic ring structure. The first crosslinked material 1 may be a commercially available product or a self-prepared product, as long as the material meeting the above requirements can be used as the first crosslinked material 1, and for example, the first crosslinked material 1 may be a polyester product obtained by reacting dimethyl terephthalate, sodium sulfoisophthalate, propylene glycol, tetrabutyl titanate, ethylene glycol, diethylene glycol, and adipic acid.

The acid value of the copolyester is 5-20 KOHmg/g, preferably 7-15 KOHmg/g, such as 7KOHmg/g, 8KOHmg/g, 10KOHmg/g, 11KOHmg/g, 12KOHmg/g, 15KOHmg/g and the like, within the range, on one hand, the reaction of a plurality of cross-linked bodies and a cross-linking agent is facilitated, the first cross-linked body 1 and the second cross-linked body 2 are compatible, and the optical performance is improved, and on the other hand, the uneven distribution of a network structure caused by excessive cross-linking of the first cross-linked body 1 can be avoided.

The second crosslinked material 2 includes a water-soluble alcohol resin, which has a good dispersibility with the water-dispersible copolyester and can be well mixed with and reacted with the first crosslinked material 1. For example, the second crosslinked material 2 may be polyvinyl alcohol obtained by alcoholysis of polyvinyl acetate and derivatives thereof, modified products of polyvinyl alcohol by acetalization, urethanization, etherification, or phosphorylation, and saponified copolymerization products of vinyl acetate and copolymerizable monomers. Specifically, in one embodiment, the second crosslinked material 2 may be an alcohol resin obtained by alcoholysis and saponification of an ethylene glycol-vinyl acetate copolymer, a vinyl alcohol-vinyl butyral copolymer or an ethylene-vinyl alcohol copolymer, or a polyvinyl alcohol resin, and in consideration of the difficulty in processing, the second crosslinked material 2 is preferably a polyvinyl alcohol resin, so that the second crosslinked material can be directly fed after being purchased on the market without a complicated pretreatment process.

The saponification degree of the water-soluble alcohol resin is 80% -98%, and in the range, the dissolving performance of the water-soluble alcohol resin can be guaranteed to be enough to meet the preparation requirement of antistatic liquid, the cross-linking reaction sequence can be guaranteed, and a network structure can be formed. Further, the degree of saponification of the water-soluble alcohol resin is preferably 85% to 90%.

The antistatic material A3 is used to be dispersed in the network structure of the antistatic layer, and may be any material having antistatic properties and capable of being uniformly dispersed in a plurality of crosslinked systems in principle. In some embodiments, the antistatic material A3 is a non-crosslinkable material, i.e., the antistatic material A3 does not have a reactive group capable of crosslinking reaction with the first crosslinked body 1 and the second crosslinked body 2, and the antistatic material A3 includes at least one of cationic antistatic aids or at least one of anionic antistatic aids. Specifically, the antistatic material A3 comprises at least one of a long-chain alkyl quaternary ammonium cationic antistatic auxiliary agent and a phosphorus salt cationic antistatic auxiliary agent, or at least one of an alkyl sulfonate anionic antistatic auxiliary agent, a phosphate anionic antistatic auxiliary agent and a dithiocarbamate anionic antistatic auxiliary agent; more specifically, the antistatic material A3 may be sodium dodecylbenzenesulfonate, (3-lauramidopropyl) trimethylammonium methyl sulfate and antistatic agent LS, or stearamidopropyl dimethyl β -hydroxyethylammonium dihydrogen phosphate.

The antistatic material B4 serves to participate in the crosslinked network. The antistatic material B4 is an antistatic agent with active groups on main/side chains and/or terminal groups, and can react with a cross-linking agent to form an interpenetrating network together with the first cross-linked body 1 and the second cross-linked body 2. In some embodiments, the antistatic material B4 comprises a non-ionic antistatic aid, and the antistatic material B4 is a crosslinkable material. In particular, the antistatic material B4 comprises a polyether polyol non-ionic antistatic aid, for example, polyethylene glycol 200.

As a preferred embodiment, the antistatic material A3 is an anionic antistatic aid, and the antistatic material B4 is a nonionic antistatic aid, so that the antistatic effect of the antistatic optical film 100 can be improved, and the stability of the antistatic effect can be improved. Further, the weight ratio of the antistatic material A3 to the antistatic material B4 is (0.2 to 0.5): 1, preferably (0.3 to 0.4): 1, so that it is possible to improve the antistatic performance, to contribute to maintaining the structural stability of the antistatic component in the antistatic layer, and to ensure the retention of the antistatic optical film 100 in a low-temperature and low-humidity environment.

Further, a slipping agent, an ultraviolet absorber, a flame retardant, a heat stabilizer, an antioxidant, and the like may be appropriately added to the antistatic functional layer as necessary without affecting the effect of the present invention.

In addition, the invention also provides a preparation method of the antistatic optical film 100, which is used for preparing the antistatic optical film 100. Fig. 4 is a diagram illustrating an embodiment of a method for manufacturing an antistatic optical film 100 according to the present invention.

Referring to fig. 4, the method for preparing the antistatic optical film 100 includes the steps of:

step S10, a polyester base layer 10 is provided.

The material of the polyester substrate 10 includes one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyarylate (PAR), polyethylene terephthalate-1,4-cyclohexanedimethanol (PCT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), 1.3 polytrimethylene terephthalate (PTT), and polytrimethylene naphthalate (PTN), or a copolymer of a plurality of the above materials, preferably PET.

The thickness of the polyester base layer 10 may be adjusted according to actual needs, or may be adjusted according to the total thickness of the antistatic optical film 100, and the total thickness of the antistatic optical film 100 is preferably 30 to 300 μm.

Step S20, after the polyester base layer 10 is heat-treated, an antistatic liquid is coated on the surface of the polyester base layer 10 to form an antistatic coating.

Specifically, the first crosslinking agent includes a copolyester, preferably a water-dispersible copolyester having an aromatic ring structure, and more preferably a copolyester having an acid value of 5 to 20KOHmg/g.

The second crosslinked material includes a water-soluble alcohol resin, and for example, the second crosslinked material may be a polyvinyl alcohol resin or at least one of an ethylene glycol-vinyl acetate copolymer, a vinyl alcohol-vinyl butyral copolymer, and an ethylene-vinyl alcohol copolymer, which has been subjected to saponification treatment, and is preferably a polyvinyl alcohol resin. The water-soluble alcohol resin has a saponification degree of 80% to 98%.

The crosslinking agent may be any of the common crosslinking agents capable of participating in a crosslinking reaction. In some embodiments, the crosslinking agent includes a melamine-based, isocyanate-based, or carbodiimide-based crosslinking agent, and thus, the transparency of the antistatic layer can be improved and the formation of a network structure can be facilitated; in some embodiments, the crosslinking agent is a blocked isocyanate, such as Toluene Diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene Diisocyanate (HDI), lysine Diisocyanate (LDI), etc., so that the crosslinking reaction temperature is easier to control, which helps to optimally control the network structure and facilitates process blending in a practical industrial production process. In this regard, as a preferred embodiment, the crosslinking agent of this embodiment is preferably blocked isocyanates, and more preferably T, which has a deblocking temperature higher than that of the polyester-based layer 10 _g (glass transition temperature of polyester base layer 10 material) 5-50 deg.C, and polyethylene terephthalate (T) _g : for example, 75 ℃ C.), the crosslinking agent is preferably a blocked isocyanate HY-243FW.

The antistatic component comprises an antistatic material A and an antistatic material B, wherein the antistatic material A comprises at least one of cationic antistatic aids or at least one of anionic antistatic aids, and the antistatic material A is a non-crosslinkable material; specifically, the antistatic material A comprises at least one of a long-chain alkyl quaternary ammonium cation antistatic auxiliary agent and a phosphate cation antistatic auxiliary agent, or at least one of an alkyl sulfonate anion antistatic auxiliary agent, a phosphate anion antistatic auxiliary agent and a dithiocarbamate anion antistatic auxiliary agent. The antistatic material B comprises a nonionic antistatic auxiliary agent, and is a crosslinkable material; in particular, the antistatic material B comprises a polyether polyol. Further, preferably, the antistatic material a is an anionic antistatic aid, the antistatic material B is a nonionic antistatic aid, and the weight ratio of the antistatic material a to the antistatic material B is 0.2 to 0.5.

The leveling agent can be any one of the leveling agents commonly available on the market, and is preferably a leveling agent with better compatibility with other components, for example, the leveling agent is one or a mixture of BYK333, BYK3510, BYK358 and BYK 380.

The weight parts of the components directly affect the performance of the antistatic layer, for example, when the addition amount of the first cross-linking agent is too low, the interpenetrating network structure is easy to be unstable, so that the antistatic layer falls off from the substrate, and when the addition amount of the first cross-linking agent is too high, the dispersibility of the components of the antistatic liquid is easy to be reduced, so that the haze and the uniformity of the antistatic performance of the antistatic optical film 100 are affected; because the second crosslinking body plays a role in the whole main skeleton of the crosslinking network, when the addition amount of the second crosslinking body is too low, the strength of the crosslinking network is easy to be low, and the stability is poor; the second component contains a large amount of reactive functional hydroxyl groups, and when the addition amount of the second crosslinking agent is too high, the uniform dispersion of other components is not facilitated, a network structure with multiple components which are mutually interwoven and mutually penetrated is not facilitated, the uniform dispersion of the antistatic component is not facilitated, and the uniformity and the stability of the antistatic performance are influenced; when the amount of the antistatic component added is too high, the uniformity of mutual dispersion of the antistatic agent and other components is greatly increased, which in turn causes the uneven distribution of the antistatic component, thereby affecting the uniformity of the antistatic performance of the antistatic optical film 100 and the stability in a low-temperature and low-humidity environment. Based on the above, the invention optimizes the weight parts of the components as follows: 20 to 60 portions of first cross-linked body, 5 to 30 portions of second cross-linked body, 0.1 to 5 portions of cross-linking agent, 0.3 to 1 portion of antistatic component and 0.1 to 2 portions of flatting agent. Within this range, the antistatic optical film 100 is most effective in combination in terms of optical properties, stability, cost, and the like.

In order to accelerate the curing rate of the antistatic coating in the subsequent crosslinking curing process and strengthen and refine the size of a phase domain between the through networks, the antistatic liquid can also comprise a catalyst, and the weight ratio of the catalyst to the first crosslinked object is (0.3-2): (20-60), namely, the antistatic liquid comprises the following components in parts by weight: 20 to 60 portions of first cross-linked body, 5 to 30 portions of second cross-linked body, 0.1 to 5 portions of cross-linking agent, 0.3 to 1 portion of antistatic component, 0.1 to 2 portions of flatting agent and 0.3 to 2 portions of catalyst. Preferably, the catalyst is added in an amount of 0.1 to 1 part per 20 to 60 parts of the first crosslinked material. Specifically, the catalyst may be a tertiary amine-based catalyst or an organometallic compound catalyst, for example, triethylamine, triethylenediamine, stannous octoate, dibutyltin dilaurate, lead octoate, cobalt octoate, iron octoate, zinc naphthenate, tetraisobutyl ferrite, or the like. In this embodiment, an organometallic compound catalyst, such as dibutyltin dilaurate T-12, is preferred, and the catalytic efficiency of the organometallic compound catalyst to the reaction system is higher than that of other catalysts.

In addition, on the premise of not influencing the effect of the invention, other functional auxiliaries can be properly added into the antistatic liquid, for example, a wetting agent is properly added to enable the antistatic liquid to be rapidly diffused on the polyester base layer 10; some inorganic particles are properly added to obtain better slip properties, and the like.

In the above formulation, the parts by weight of each component refers to the parts by weight of the effective fixed components of the component, for example, 100 parts by weight of the first cross-linked dispersion in an antistatic liquid, 30% by weight of the solid content thereof, and 30 parts by weight of the first cross-linked material in the antistatic liquid.

In addition, when the polyester base layer 10 is coated, it is preferable that the polyester base layer 10 is heat-treated first to make the polyester base layer 10 have higher chain motion characteristics due to high temperature, which facilitates the penetration of the antistatic liquid into the interior of the polyester base layer 10 during the coating process, thereby enhancing the antistatic coating and the antistatic coatingThe bonding firmness of the polyester base layer 10 contributes to the formation of a three-dimensional network structure and the distribution uniformity of the antistatic components, and improves the antistatic effect. In some embodiments, the temperature of the surface of the polyester base layer 10 is raised to (T) by the heat treatment _g -10～T _g + 20) deg.C and applying an antistatic liquid at the surface temperature, wherein T is _g Refers to the glass transition temperature of the polyester base layer 10 material. When the temperature of the surface of the polyester base layer 10 is within this range, it is possible to ensure the heat treatment effect, improve the antistatic stability of the antistatic optical film 100, and prevent bubbles from occurring in the antistatic coating layer due to too rapid volatilization of the antistatic liquid.

And S30, carrying out heat treatment on the antistatic coating so as to enable the antistatic coating to be crosslinked and cured to form an antistatic layer.

This example heat-treats the antistatic coating to cause a crosslinking reaction of the components of the antistatic coating, thereby curing to form an antistatic layer. Specifically, the temperature of the heat treatment is 100 to 150 ℃. The solidification in the temperature interval can ensure that the base material does not generate thermal deformation and can meet the temperature condition that the base material can be changed in post processing to the maximum extent.

Wherein the thickness of the antistatic layer is 0.1-1.2 mu m; the surface resistance of the antistatic layer at the side departing from the polyester base layer 10 is less than 5 multiplied by 10 ¹⁰ Ω/m ² 。

In addition, it is understood that steps S20 and S30 may be adaptively adjusted in actual operation according to the structural design of the antistatic optical film 100. For example, in the structural design in which the antistatic layers are disposed on both sides of the polyester base layer 10, after the antistatic liquid is coated on one side and the antistatic layers are formed by heat treatment and curing, the antistatic liquid is further coated on the other side and the antistatic layers are formed by heat treatment and curing, or after the antistatic liquid is coated on both sides, the both sides are uniformly heat treated.

The technical solutions of the present invention are further described in detail below with reference to specific examples and drawings, it should be understood that the following examples are merely illustrative of the present invention and are not intended to limit the present invention.

The following examples the preparation of the components of the antistatic liquid was as follows:

preparation of different kinds of first crosslinker dispersions:

(1) The preparation method of the copolyester I liquid comprises the following steps: 194.2 parts by weight of dimethyl terephthalate, 29.6 parts by weight of sodium m-benzenedimethyl-5-sulfonate, 3.8 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 62 parts by weight of ethylene glycol and 106 parts by weight of diethylene glycol were added to an autoclave, stirring was started at 160 ℃, and then the temperature was gradually raised to 240 ℃ within the following 5 hours, and the transesterification reaction was fully completed. Then gradually reducing the pressure to 60Pa, and reacting for 1.5-2 h at 235-245 ℃ to obtain the copolyester with the acid value of 8 KOHmg/g. And dispersing a certain amount of the copolyester prepared above in deionized water to prepare a copolyester I liquid with the solid content of 30%.

(2) The preparation method of the copolyester II liquid comprises the following steps: the procedure was the same as that for the copolyester I liquid except that "194.2 parts by weight of dimethyl terephthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 3.8 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 124 parts by weight of ethylene glycol, 212 parts by weight of diethylene glycol were charged into the autoclave" was changed to "97.1 parts by weight of dimethyl terephthalate, 97.1 parts by weight of dimethyl isophthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 76 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 62 parts by weight of ethylene glycol, 84.8 parts by weight of diethylene glycol were charged into the autoclave". The solid content of the copolyester II solution is 30 percent, and the acid value is 20KOHmg/g.

(3) The preparation method of the copolyester III liquid comprises the following steps: the procedure was the same as that for the copolyester I liquid except that "194.2 parts by weight of dimethyl terephthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 3.8 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 62 parts by weight of ethylene glycol, 106 parts by weight of diethylene glycol were charged into the autoclave" was changed to "194.2 parts by weight of dimethyl terephthalate, 48.5 parts by weight of dimethyl isophthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 3.8 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 93 parts by weight of ethylene glycol, 106 parts by weight of diethylene glycol were charged into the autoclave". The copolyester III solution had a solid content of 30% and an acid value of 5KOHmg/g.

(4) The preparation method of the copolyester IV liquid comprises the following steps: the procedure was the same as that for the copolyester I liquid except that "194.2 parts by weight of dimethyl terephthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 3.8 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 62 parts by weight of ethylene glycol, 106 parts by weight of diethylene glycol were charged into the autoclave" was changed to "194.2 parts by weight of dimethyl terephthalate, 48.5 parts by weight of dimethyl isophthalate, 29.6 parts by weight of sodium m-phthalate-5-sulfonate, 19 parts by weight of propylene glycol, 0.3 part by weight of tetrabutyl titanate, 139.5 parts by weight of ethylene glycol, 50 parts by weight of diethylene glycol were charged into the autoclave". The copolyester IV solution has a solid content of 30% and an acid value of 2KOHmg/g.

Preparation of different kinds of second crosslinker dispersions:

(1) The preparation method of the resin I liquid comprises the following steps: adding 15 parts of polyvinyl alcohol resin with the polymerization degree of 500 and the saponification degree of 90 into 85 parts of deionized water, mechanically stirring for 3 hours at 80 ℃ to completely dissolve the polyvinyl alcohol resin, and naturally cooling to room temperature. The solid content of the resin I liquid is 20%.

(2) The preparation method of the resin II liquid comprises the following steps: adding 15 parts of polyvinyl alcohol resin with the polymerization degree of 500 and the saponification degree of 98 into 85 parts of deionized water, mechanically stirring for 3 hours at the temperature of 80 ℃ to completely dissolve the polyvinyl alcohol resin, and naturally cooling to room temperature. The solid content of the resin I liquid is 20%.

(3) The preparation method of the resin III liquid comprises the following steps: adding 15 parts of polyvinyl alcohol resin with the polymerization degree of 500 and the saponification degree of 80 into 85 parts of deionized water, mechanically stirring for 3 hours at 80 ℃ to completely dissolve the polyvinyl alcohol resin, and naturally cooling to room temperature. The solid content of the resin I liquid is 20%.

Example 1

TABLE 1 formulation of antistatic liquid

The components listed in the table 1 are added into a container with a stirrer according to the proportion of parts at 25 ℃, and the antistatic liquid is obtained after stirring for 2 hours at the rotating speed of 400 r/min.

A biaxially oriented polyethylene terephthalate film (Hefei Leqia) having a thickness of 50 μm and an A4 size was used as the polyester base layer 10.

Fixing four sides of the polyester base layer 10, placing the polyester base layer in a 90 ℃ blast oven for 2min, and stabilizing the temperature of the polyester base layer 10 at 90 ℃. And quickly taking out the polyester base layer 10, placing the polyester base layer on a flat desktop, immediately coating antistatic liquid on the surface of the polyester base layer 10 by using a coating rod, immediately placing the coated film into a vacuum oven at 120 ℃ for curing for 1min to obtain the antistatic optical film 100, wherein the thickness of an antistatic layer in the antistatic optical film 100 is 0.5 mu m.

Example 2

The procedure was the same as in example 1 except that the components of the antistatic liquid were adjusted to the formulations shown in Table 2.

TABLE 2 antistatic liquid formulation

Example 3

The procedure was the same as in example 1 except that the components of the antistatic liquid were adjusted to the formulations shown in Table 3.

TABLE 3 antistatic liquid formulation

Example 4

The procedure was the same as in example 1 except that the components of the antistatic liquid were adjusted to the formulations shown in Table 4.

TABLE 4 antistatic liquid formulation

Example 5

The procedure was the same as in example 1 except that the components in the antistatic liquid were adjusted to the formulations shown in Table 5.

TABLE 5 antistatic liquid formulation

Example 6

The procedure of example 1 was repeated except that the dispersion of the first crosslinking agent in the antistatic liquid was changed to a copolyester II liquid.

Example 7

The procedure was the same as in example 1 except that the kind of the first crosslinking agent dispersion liquid in the antistatic liquid was changed to the copolyester III liquid.

Example 8

The procedure of example 1 was repeated except that the kind of the second crosslinking agent dispersion liquid in the antistatic liquid was changed to resin II liquid.

Example 9

The procedure of example 1 was repeated except that the kind of the second dispersion of a crosslinking agent in the antistatic liquid was changed to the resin III liquid.

Example 10

The procedure was the same as in example 1 except that the thickness of the antistatic layer was adjusted to 0.2. Mu.m.

Example 11

The procedure was the same as in example 1 except that the thickness of the antistatic layer was adjusted to 0.1. Mu.m.

Example 12

The procedure was the same as in example 1 except that the thickness of the antistatic layer was adjusted to 1.2. Mu.m.

Example 13

The procedure was as in example 1 except that "the four sides of the polyester base layer 10 were fixed and then placed in the 90 ℃ forced air oven for 2min to stabilize the temperature of the polyester base layer 10 at 90" was changed to "the four sides of the polyester base layer 10 were fixed and then placed in the 95 ℃ forced air oven for 2min to stabilize the temperature of the polyester base layer 10 at 95".

Example 14

The procedure was as in example 1 except that "the four sides of the polyester base layer 10 were fixed and then placed in the 90 ℃ forced air oven for 2min to stabilize the temperature of the polyester base layer 10 at 90" was changed to "the four sides of the polyester base layer 10 were fixed and then placed in the 65 ℃ forced air oven for 2min to stabilize the temperature of the polyester base layer 10 at 65".

Example 15

The procedure was as in example 1 except that the curing temperature was adjusted from 120 ℃ to 100 ℃.

Example 16

The procedure was as in example 1 except that the curing temperature was adjusted from 120 ℃ to 150 ℃.

Example 17

The procedure is as in example 1 except that the antistatic material A is adjusted from sodium dodecylbenzenesulfonate to stearamidopropyl dimethyl β -hydroxyethylammonium dihydrogenphosphate.

Example 18

The procedure was the same as in example 1 except that the antistatic material A was adjusted from sodium dodecylbenzenesulfonate to (3-laurylamidopropyl) trimethylammonium methyl sulfate and the antistatic agent LS.

Comparative example 1

The procedure of example 1 was repeated except that "the polyester base layer 10 was stabilized at 90 ℃ for 2min in a 90 ℃ forced air oven" instead of "the polyester base layer 10 was stabilized at 90 ℃ for 2min in a 25 ℃ forced air oven" after four sides of the polyester base layer 10 were fixed.

Comparative example 2

The procedure was the same as in example 1 except that the thickness of the antistatic layer was adjusted to 1.5. Mu.m.

Comparative example 3

The procedure was the same as in example 1 except that the kind of the first crosslinking agent dispersion liquid in the antistatic liquid was changed to copolyester iv liquid.

Comparative example 4

The procedure of example 1 was repeated except that the components in the antistatic liquid were adjusted to the formulations shown in Table 6.

TABLE 6 antistatic liquid formulation

The antistatic optical films 100 obtained in examples 1 to 18 and comparative examples 1 to 4 were measured for surface resistance, light transmittance, and haze (respectively, surface resistance 1, light transmittance 1, and haze 1), and the results are shown in table 7. The antistatic optical films 100 prepared in the above examples 1 to 18 and comparative examples 1 to 4 were then left to stand at 25 ℃ and 20% relative humidity for 720h, and then tested for surface resistance (denoted as surface resistance 2), and then light transmittance and haze (denoted as light transmittance 2 and haze 2, respectively) were measured, and the results are shown in table 7.

Wherein, the surface resistance is obtained by detecting a surface resistance meter (HZR: model-100); the light transmittance and haze were measured by a light transmittance haze meter (Shanghai Meter electro-optical Co., ltd.; model SGW-820).

TABLE 7 Performance test

As can be seen from the above table, compared with the common polyester film (polyethylene terephthalate film), the antistatic optical film 100 prepared in each example has better antistatic property and still has better performance stability in low-temperature and low-humidity environment; the antistatic optical film 100 prepared in each example has better performance stability than comparative example 3, and has better haze than comparative example 3. The antistatic optical film 100 prepared by the method of the present invention has good antistatic property, light transmittance and haze, and also has good performance stability in a low humidity environment.

The above is only a preferred embodiment of the present invention, and it is not intended to limit the scope of the invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. An antistatic optical film is characterized by comprising a polyester base layer, wherein at least one side of the polyester base layer is provided with an antistatic layer, the antistatic layer is formed by crosslinking a plurality of crosslinking bodies, and an antistatic material A is dispersed in the antistatic layer;

wherein the plurality of crosslinks includes a first crosslink, a second crosslink, and an antistatic material B;

the first crosslinking body comprises copolyester, and the acid value of the copolyester is 5-20KOHmg/g; the weight ratio of the antistatic material A to the antistatic material B is (0.2 to 0.5) 1;

the second crosslinking agent comprises a water-soluble alcohol resin, and the saponification degree of the water-soluble alcohol resin is 80-98%;

the antistatic material A comprises at least one of cationic antistatic aids or at least one of anionic antistatic aids, and the antistatic material A is a non-crosslinkable material;

2. The antistatic optical film of claim 1 wherein the thickness of the antistatic layer is 0.1 to 1.2 μ ι η; and/or the presence of a gas in the atmosphere,

the surface resistance of the antistatic layer at the side departing from the polyester base layer is less than 5 multiplied by 10 ¹⁰ Ω/m ² 。

3. The antistatic optical film of claim 1 wherein the copolyester is a water-dispersible copolyester having an aromatic ring structure; and/or the presence of a gas in the gas,

the second crosslinked body includes a polyvinyl alcohol resin; and/or the presence of a gas in the atmosphere,

the antistatic material A comprises at least one of a long-chain alkyl quaternary ammonium cation antistatic auxiliary agent and a phosphorus salt cation antistatic auxiliary agent, or at least one of an alkyl sulfonate anion antistatic auxiliary agent, a phosphate anion antistatic auxiliary agent and a dithiocarbamate anion antistatic auxiliary agent; and/or the presence of a gas in the gas,

4. A method for preparing an antistatic optical film according to any one of claims 1 to 3, comprising the steps of:

providing a polyester substrate;

the antistatic liquid comprises the following components in parts by weight: 20 to 60 parts of a first cross-linking body, 5 to 30 parts of a second cross-linking body, 0.1 to 5 parts of a cross-linking agent, 0.3 to 1 part of an antistatic component and 0.1 to 2 parts of a leveling agent, wherein the antistatic component comprises an antistatic material A and an antistatic material B.

5. The method for producing an antistatic optical film as claimed in claim 4, wherein the step of applying an antistatic liquid to the surface of the polyester base layer after the heat treatment of the polyester base layer to form an antistatic coating layer is carried out at a temperature of (T) _g -10~T _g + 20) ° c is coated with an antistatic liquid to form an antistatic coating.

6. The method for producing an antistatic optical film according to claim 4, wherein the heat treatment temperature in the step of heat-treating the antistatic coating layer to crosslink and cure the antistatic coating layer to form an antistatic layer is 100 to 150 ℃.

7. The method for producing an antistatic optical film as claimed in claim 4, wherein the antistatic liquid further comprises a catalyst, and the catalyst comprises a tertiary amine catalyst or an organometallic compound catalyst.

8. A display panel comprising the antistatic optical film according to any one of claims 1 to 3.