阅读说明：本技术 一种偏光片保护膜用丙烯酸酯聚合物及其应用 (Acrylate polymer for polarizer protective film and application thereof ) 是由 吴喜来 汪中洋 芋野昌三 陈洪野 吴小平 于 2021-01-14 设计创作，主要内容包括：本发明一种偏光片保护膜用丙烯酸酯聚合物及其应用,偏光片保护膜用丙烯酸酯聚合物,包括如下组分：软单体；硬单体；功能单体；可聚合表面活性剂；特殊单体；溶剂a；自由基引发剂。本发明提供的偏光片保护膜用丙烯酸酯聚合物及其应用,采用偏光片保护膜用丙烯酸酯聚合物可制成偏光片保护膜用聚丙烯酸酯组成物,采用偏光片保护膜用聚丙烯酸酯组成物可制成偏光片保护膜,具有一定柔软度,模切成小尺寸时不产生粉屑,不污染电子产品表面,合成过程中采用可聚合表面活性剂,不会随着时间的推移迁移至胶层表面而造成偏光片暗影等,抗静电值稳定,高温等老化后粘性爬升不明显,在偏光片制程、运输及存储过程中起临时保护作用,便于撕离偏光片表面。(The invention relates to an acrylate polymer for a polarizer protective film and application thereof, wherein the acrylate polymer for the polarizer protective film comprises the following components: a soft monomer; a hard monomer; a functional monomer; a polymerizable surfactant; a special monomer; a solvent a; a free radical initiator. The invention provides an acrylic ester polymer for a polarizer protective film and application thereof, wherein the acrylic ester polymer for the polarizer protective film can be used for preparing a polyacrylic ester composition for the polarizer protective film, the polyacrylic ester composition for the polarizer protective film can be used for preparing the polarizer protective film, the polarizer protective film has certain softness, no powder scrap is generated when the polarizer protective film is die-cut into small sizes, and the surface of an electronic product is not polluted.)

1. The acrylate polymer for the polarizer protective film is characterized by comprising the following components in parts by weight:

2. the acrylate polymer for a polarizer protective film according to claim 1, wherein the soft monomer is one or a combination of butyl acrylate, isooctyl acrylate, isobutyl acrylate, ethyl acrylate and n-propyl acrylate; the hard monomer is one or a combination of more of n-butyl methacrylate, methyl acrylate, ethyl methacrylate, methyl methacrylate and ethoxy ethyl acrylate; the functional monomer is one or a combination of more of hydroxyethyl acrylate, 2-hydroxypropyl acrylate, N-hydroxymethyl acrylamide, hydroxypropyl acrylate and acrylamide.

3. The acrylate polymer for a polarizer protective film according to claim 1, wherein the polymerizable surfactant is one or a combination of maleic anhydride diester type cationic polymerizable surfactant, sodium sulfosuccinate, dodecyl dimethyl ethyl methacrylate, and methyl propylene oxyethyl dodecyl dimethyl ammonium bromide.

4. The acrylate polymer for a polarizer protective film according to claim 1, wherein the specific monomer is 4-hydroxybutylacrylate.

5. The acrylate polymer for a polarizer protective film according to claim 1, wherein the solvent a is one or a combination of dimethyl carbonate, ethyl acetate, toluene, isopropanol and heptane.

6. The acrylate polymer for a polarizer protective film according to claim 1, wherein the radical initiator is one or a combination of several of azobisisobutyronitrile, benzoyl peroxide, t-butyl hexahydro peroxyterephthalate, azobisisoheptonitrile and azobisisovaleronitrile.

7. Use of the acrylate polymer for a polarizer protective film according to any one of claims 1 to 6 for preparing a polyacrylate composition for a polarizer protective film.

8. The use of the acrylate polymer for a polarizer protective film according to claim 7 in the preparation of a polyacrylate composition for a polarizer protective film, wherein the polyacrylate composition for a polarizer protective film is prepared by using the acrylate polymer for a polarizer protective film according to any one of claims 1 to 6, a solvent b and a curing agent; the polyacrylate composition for the polarizer protective film comprises the following components in parts by weight:

50-70 parts of acrylate polymer for polarizer protective film

30-50 parts of solvent b

0.5-1.5 parts of curing agent.

9. The use of the acrylate polymer for a polarizer protective film according to claim 8 in the preparation of a polyacrylate composition for a polarizer protective film, wherein the solvent b is one or a combination of ethyl acetate, butyl acetate and toluene; the curing agent is one or a combination of more of an isocyanate curing agent, an epoxy curing agent and a pyridine curing agent.

10. A polarizer protective film comprising a release film and a polyacrylate composition for polarizer protective film formed on the release film, wherein the polyacrylate composition for polarizer protective film is formed from the polyacrylate composition for polarizer protective film according to any one of claims 7 to 9.

Technical Field

The invention belongs to the technical field of preparation of polymers for polarizer protective films, and particularly relates to an acrylate polymer for a polarizer protective film and application thereof.

Background

Polarizer (Cpolarizer) is a key component of liquid crystal panels, and is widely used in consumer and industrial electronic display panels, such as mobile phones, computers, instruments and meters, and automotive electronics. The polarizer is one of three key raw materials of the LCD, and accounts for about 10-15% of the panel cost, and the larger the panel is, the higher the proportion of the cost of the polarizer is, and the global polarizer market scale is kept stable, about billions of dollars, by benefiting from the average area increase brought by the increase of large-size panels of TFT-LCDs.

The polarizer protective film is required to prevent the polarizer from being polluted or scratched on the surface of the polarizer in the processes of transportation, storage and use, and when the polarizer and the protective film are die-cut into different specifications and sizes, the protective film is required not to generate powder during die-cutting, so that the protective film and the polarizer are prevented from being polluted; in addition, when the polarizer is assembled into the liquid crystal display, the protective film and the polarizer need to be torn off, and during the tearing process, the protective film generates electrostatic voltage, which can damage the liquid crystal molecules of the liquid crystal display and damage the surface of the liquid crystal display. Therefore, there is a need to develop a polarizer protective film that does not generate dust during die cutting, has air-release property during polarizer attachment, and is easy to tear or peel off from the polarizer surface, i.e., requires low viscosity, and also requires antistatic function (generally requires an antistatic value of 10)¹⁰Ω or less).

The Chinese invention patent, publication No. CN201910881930.5, discloses a pressure-sensitive adhesive for polarizer protective films and a preparation method thereof, the composition of the synthesized acrylate polymer is simple, the antistatic component and the mechanism description are not introduced, and the length of the antistatic value and the peeling force value after aging resistance are not verified.

The prior polymer for the polarizer protective film and the polarizer protective film thereof (Chinese patent of invention, publication No. CN201611155844.9) introduce a polymer synthesis process, wherein an antistatic agent adopts a post-addition mode, namely, the polymer is synthesized firstly and then the antistatic agent is added for physical mixing, when the polymer is coated into the polarizer protective film, the antistatic agent has the risk of precipitation, the surface of the polarizer is polluted, and the antistatic value of an adhesive layer is increased relatively quickly.

The Chinese invention patent, publication No. CN111187584A, relates to the technical field of films, in particular to a pressure-sensitive adhesive and a polarizer protective film thereof; the pressure-sensitive adhesive adopts deionized water, a reactive emulsifier, a soft monomer, a hard monomer, a functional monomer and a water-based isocyanate curing agent, although the antistatic value of the adhesive layer is 10⁹Below omega, after the high temperature and high humidity test for 500 hours, the protective film is still tightly attached to the polaroid without bubbles and bulges, and the protective film is torn off without residual glue and shadows. However, no polarizer protective film made by polymerization of water-based acrylate is available in the market, and because emulsion particles are aggregated in a film forming mode of water-based acrylate emulsion, an emulsifier is a mixture and small molecules exist, namely, the risk of shadow exists.

The prior pressure-sensitive adhesive for the polarizer protective film and the protective film technology thereof (Chinese invention patent, publication No. CN108384476A) disclose that when the polarizer protective film is attached to the polarizer, the protective film is tightly attached to the polarizer after a high-temperature high-humidity test is carried out for 500h, no bubble is blown, and the protective film is torn off without the defects of residual adhesive, shadow and the like. The fluorine-containing acrylate monomer and the antistatic agent are adopted to achieve the functions of attaching air exhaust and antistatic, but no description is given to whether the stickiness climbs after the protective film is subjected to die cutting and powdering and high temperature.

The prior pressure-sensitive adhesive for the polarizer protective film and the polarizer protective film (Chinese patent of invention, publication No. CN106597596A) disclose that the acrylate polymer can be directly coated on the surface of a polyester film without the need of coating the acrylate polymer on the surface of the polyester filmCuring agent and antistatic agent are added, and the glue line resistance is 10¹⁰The protective film has antistatic performance below omega, and when the protective film is attached to the surface of the polaroid, the protective film is tightly attached to the polaroid after a high-temperature high-humidity test is carried out for 12 hours, so that the defects of bubble bulge and the like are avoided; the antistatic agent in the synthesized product is added in a post-adding mode, and the antistatic stability and precipitation, particularly the stripping force after 500 hours of high temperature and high humidity and pollution on the surface of the polaroid are not verified.

Therefore, the existing polymers for polarizer protective films generally need to be verified and illustrated to satisfy antistatic, adhesive, light transmittance, haze and aging properties. Meanwhile, the polarizer protective film also has requirements on the antistatic value and the die cutting performance after being stored for a certain time at present.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention aims to provide an acrylate polymer for a polarizer protective film and application thereof.

In order to achieve the purpose and achieve the technical effect, the invention adopts the technical scheme that:

the acrylic ester polymer for the polarizer protective film comprises the following components in parts by weight:

furthermore, the soft monomer is one or a combination of butyl acrylate, isooctyl acrylate, isobutyl acrylate, ethyl acrylate and n-propyl acrylate.

Further, the hard monomer is one or a combination of several of n-butyl methacrylate, methyl acrylate, ethyl methacrylate, methyl methacrylate and ethoxyethoxyethyl acrylate.

Further, the functional monomer is one or a combination of more of hydroxyethyl acrylate, 2-hydroxypropyl acrylate, N-hydroxymethyl acrylamide, hydroxypropyl acrylate and acrylamide.

Further, the polymerizable surfactant is one or a combination of more of maleic anhydride diester type cationic polymerizable surfactant, sodium sulfosuccinate, dodecyl dimethyl ethyl methacrylate and methacrylic oxyethyl dodecyl dimethyl ammonium bromide.

Further, the special monomer is 4-hydroxy butyl acrylate.

Further, the solvent a is one or a combination of more of dimethyl carbonate, ethyl acetate, toluene, isopropanol and heptane.

Further, the free radical initiator is one or a combination of several of azobisisobutyronitrile, benzoyl peroxide, tert-butyl hydroperoxide terephthalate, azobisisoheptonitrile and azobisisovaleronitrile.

The invention discloses a preparation method of an acrylate polymer for a polarizer protective film, which is prepared by adopting a solution free radical polymerization method and comprises the following steps:

mixing a soft monomer, a hard monomer, a functional monomer, a polymerizable surfactant and a solvent a to obtain a mixed solution A;

under the protection of nitrogen, adding one half of the mixed solution A into a four-neck flask with a condenser, a separating funnel and a thermometer, heating to a constant temperature of 67-73 ℃, adding one third of the free radical initiator solution, reacting for 1h at 67-73 ℃, dropwise adding the rest of the mixed solution A and the rest of the free radical initiator solution, dropwise adding for 80min, then preserving heat for 2h, finally dropwise adding the rest of the free radical initiator solution, continuously preserving heat for 180min, cooling and discharging after the reaction is finished, and thus obtaining the required acrylate polymer for the polarizer protective film.

The invention discloses an application of an acrylate polymer for a polarizer protective film in preparation of a polyacrylate composition for the polarizer protective film.

The invention discloses a polyacrylate composition for a polarizer protective film, which is prepared by adopting an acrylate polymer for the polarizer protective film, a solvent b and a curing agent; the polyacrylate composition for the polarizer protective film comprises the following raw material components in parts by weight:

50-70 parts of acrylate polymer for polarizer protective film

30-50 parts of solvent b

0.5-1.5 parts of curing agent.

Further, the solvent b is one or a combination of several of ethyl acetate, butyl acetate and toluene.

Further, the curing agent is one or a combination of more of an isocyanate curing agent, an epoxy curing agent and a pyridine curing agent.

The invention discloses a polarizer protective film, which comprises a release film and a polyacrylate composition for the polarizer protective film, wherein the polyacrylate composition is formed on the release film, the polyacrylate composition for the polarizer protective film is formed by acrylate polymer for the polarizer protective film, and the thickness of a glue layer on the release film is 10-15 mu m.

The invention discloses a preparation method of a polarizer protective film, which comprises the following steps:

and uniformly mixing the acrylate polymer for the polarizer protective film, the solvent b and the curing agent, coating the mixture on a release film, and heating the release film to be attached to the corona surface of the optical PET.

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

the invention discloses an acrylate polymer for a polarizer protective film and application thereof, wherein the acrylate polymer for the polarizer protective film comprises the following components in parts by weight: 70-90 parts of a soft monomer; 5-20 parts of a hard monomer; 2-5 parts of a functional monomer; 5-10 parts of polymerizable surfactant; 2-8 parts of special monomers; 50-70 parts of a solvent a; 0.2-0.6 part of free radical initiator. The invention provides an acrylic ester polymer for a polarizer protective film and application thereof, wherein the acrylic ester polymer for the polarizer protective film can be used for preparing a polyacrylic ester composition for the polarizer protective film, the polyacrylic ester composition for the polarizer protective film can be used for preparing the polarizer protective film, the polarizer protective film has certain softness, the acrylic ester polymer synthesized by special monomers is used for resisting scraping and powdering, no powder scrap is generated when the polarizer protective film is cut into small size, the surface of an electronic product is not polluted, a polymerizable surfactant is used in the synthesis process, the problem that the polarizer shadow and the like are caused by the fact that the polymerizable surfactant is transferred to the surface of an adhesive layer along with the time is avoided, the antistatic value is stable, the viscosity climbing after high, the temporary protection function is realized in the processes of polarizer manufacturing, transportation and storage, and the polarizer protective film does not leave dark shadows when being torn off the surface of the polarizer, so that the polarizer protective film is convenient to tear off.

Detailed Description

The following detailed description of the embodiments of the present invention is provided to enable those skilled in the art to more easily understand the advantages and features of the present invention, and to clearly and clearly define the scope of the present invention.

Example 1

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

a preparation method of an acrylate polymer for a polarizer protective film comprises the following steps:

mixing a soft monomer, a hard monomer, a functional monomer, a polymerizable surfactant and a solvent a to obtain a mixed solution A; under the protection of nitrogen, adding one half of the mixed solution A into a four-neck flask with a condenser, a separating funnel and a thermometer, heating to a constant temperature of 67-73 ℃, adding one third of the free radical initiator solution, reacting at 67-73 ℃ for 1h, dropwise adding the rest of the mixed solution A and one third of the free radical initiator solution, keeping the temperature for 2h, finally dropwise adding the rest of the free radical initiator solution, keeping the temperature for 180min, cooling after the reaction is finished, and discharging to obtain the required acrylic ester polymer for the polarizer protective film.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

acrylic ester Polymer 70 parts

30 portions of ethyl acetate

0.9 part of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, an ethyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylic ester coating liquid on a PET release film through a coating machine, wherein the thickness of a glue layer is 15 mu m, and then compounding optical PET.

Example 2

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

the preparation method of an acrylate polymer for a polarizer protective film is the same as that of example 1.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

65 parts of acrylate polymer

40 parts of ethyl acetate

1 part of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, an ethyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylic ester coating liquid on a PET release film through a coating machine, wherein the thickness of a glue layer is 13 mu m, and then compounding optical PET.

Example 3

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

the preparation method of an acrylate polymer for a polarizer protective film is the same as that of example 1.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

acrylic ester Polymer 70 parts

30 portions of butyl acetate

1.1 parts of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, a butyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylic ester coating liquid on a PET release film through a coating machine, wherein the thickness of a glue layer is 13 mu m, and then compounding optical PET.

Comparative example 1

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

the preparation method of an acrylate polymer for a polarizer protective film is the same as that of example 1.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

65 parts of acrylate polymer

40 parts of ethyl acetate

2 parts of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, an ethyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylic ester coating liquid on a PET release film through a coating machine, wherein the thickness of a glue layer is 13 mu m, and then compounding optical PET.

Comparative example 2

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

the preparation method of an acrylate polymer for a polarizer protective film is the same as that of example 1.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

65 parts of acrylate polymer

40 parts of ethyl acetate

1 part of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, an ethyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylic ester coating liquid on a PET release film through a coating machine, wherein the thickness of a glue layer is 13 mu m, and then compounding optical PET.

Comparative example 3

An acrylate polymer for a polarizer protective film comprises the following raw materials in parts by weight:

the preparation method of an acrylate polymer for a polarizer protective film is the same as that of example 1.

A polyacrylate composition for a polarizer protective film comprises the following raw materials in parts by weight:

65 parts of acrylate polymer

40 parts of ethyl acetate

1 part of aliphatic polyisocyanate.

A preparation method of a polarizer protective film comprises the following steps:

firstly, mixing and stirring an acrylate polymer, an ethyl acetate solvent b and an aliphatic polyisocyanate curing agent uniformly to obtain an acrylate coating liquid; and coating the acrylate coating liquid on a PET release film through a coating machine, and then compounding the optical PET.

The acrylate polymers prepared in examples 1 to 3 and comparative examples 1 to 3 were used to prepare polarizer protective films, respectively, and the following tests were performed:

(1) according to the national standard GB/T2410-2008, a release film is torn off by using a haze meter (model: U3000), and the light transmittance (T) and the haze (H) are measured;

(2) and (3) testing the peel strength: according to the test method of 180-degree peel strength of the pressure-sensitive adhesive tape of 1998 (the protective film is attached to the surface of the polaroid, and the stretching speed is 300mm/min) of the national standard GB/T2792);

(3) testing the resistance of the glue layer: cutting the protective film into 12 × 12mm, tearing off the release film, and testing the surface resistance on a high resistance meter (model: SME-8310);

(4) high temperature and high humidity test: cutting the protective film into 150 × 25mm, tearing off the release film, attaching the adhesive layer of the protective film to the surface of the polaroid, putting the polaroid into a programmable constant temperature and humidity test box, observing whether the protective film has wrinkles, separation and bubbles on the surface of the polaroid after 80 ℃ and 90% humidity for 500 hours, if not, judging the protective film to be OK, and if so, judging the protective film to be NG;

(5) high-temperature test: cutting the protective film into 150 × 25mm, tearing off the release film, attaching the adhesive layer of the protective film to the surface of the polaroid, putting the polaroid into a constant-temperature oven, cooling the polaroid in a drier to room temperature after the temperature is 80 ℃ and the time is 500 hours, and testing the stripping force of the protective film according to GB/T2792-;

(6) die cutting and powdering: cutting the protective film into 150 × 25mm, and scratching the adhesive surface with fingernails, wherein if powder scraps and dents exist, the powder can be judged to be generated.

The test results are shown in Table 1.

TABLE 1

As can be seen from Table 1, the product obtained by the invention has high light transmittance, and the viscosity climbing after aging at high temperature and the like is not obvious, so that the product is convenient to tear off the surface of the polaroid, the protective film has no wrinkles, separation and bubbles on the surface of the polaroid, and the powder is not generated after die cutting.

The parts of the invention not specifically described can be realized by adopting the prior art, and the details are not described herein.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.