A pva polarizing film coated with a silicone resin, and a method for preparing and using the same

Abstract

The application provides a PVA polarizing film coated with a silicone resin and a preparation method and application thereof, and belongs to the technical field of optical materials. The PVA polarizing film coated with the silicone resin provided by the application comprises a PVA polarizing film and a silicone resin coating attached to the surface of the PVA polarizing film, and the raw materials of the silicone resin coating comprise a silicone resin and a silane coupling agent. The application forms a silicone resin coating on the surface of the PVA polarizing film by using the silicone resin and the silane coupling agent, can endow the PVA polarizing film with good heat and humidity resistance without reducing the light transmittance of the PVA polarizing film, the use of the silane coupling agent can not only promote the curing of the silicone resin at room temperature and avoid the damage of high temperature to the PVA polarizing film, but also can simultaneously react with the PVA polarizing film and the silicone resin as a medium, enhance the bonding force of the two, and further improve the water vapor barrier property of the PVA polarizing film.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical materials, in particular to a PVA polarizing film coated with silicone resin and a preparation method and application thereof. BACKGROUND

[0002] The polarizing film is one of the upstream key materials in the electronic display industry, and its essence is a composite film mainly composed of a PVA polarizing film, a TAC film, a pressure-sensitive adhesive, a release film and a protective film. The PVA polarizing film is the main structure for realizing and determining the polarization function of the polarizing film. However, the PVA is easy to absorb water, and it will quickly deform, shrink and relax in a warm environment, and the iodine will volatilize when the temperature and humidity are slightly high, resulting in discoloration of the PVA polarizing film and degradation of the polarizing performance. Therefore, improving the heat and humidity resistance of the polarizing film is a technical problem that needs to be solved urgently at present. SUMMARY

[0003] Therefore, the present application aims to provide a PVA polarizing film coated with silicone resin and a preparation method and application thereof. The PVA polarizing film coated with silicone resin provided by the present application has good heat and humidity resistance without reducing the light transmittance of the PVA polarizing film.

[0004] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] The present application provides a PVA polarizing film coated with silicone resin, which comprises a PVA polarizing film and a silicone resin coating attached to the surface of the PVA polarizing film, and the raw materials of the silicone resin coating comprise silicone resin and silane coupling agent.

[0006] Preferably, the silicone resin comprises one or more of phenyl silicone resin, methyl silicone resin, vinyl silicone resin and methyl phenyl silicone resin.

[0007] The silane coupling agent comprises one or more of 3-aminopropyl triethoxysilane, glycidyl ether oxypropyl trimethoxysilane, methacryloyl chloride propyl trimethoxysilane and ethylene triethoxysilane.

[0008] Preferably, the mass of the silane coupling agent is 1-10% of the mass of the silicone resin.

[0009] Preferably, the thickness of the silicone resin coating is 5-50 μm.

[0010] The thickness of the PVA polarizing film is 20-50 μm.

[0011] The present application provides a preparation method of the above-mentioned PVA polarizing film coated with silicone resin, which comprises the following steps:

[0012] The silicone resin was mixed with a silane coupling agent, and after defoaming, a mixture was obtained.

[0013] The mixture is coated onto the surface of a PVA polarizing film and cured to obtain a PVA polarizing film coated with silicone resin.

[0014] Preferably, before coating, the PVA polarizing film is further pretreated, the pretreatment including the following steps:

[0015] The PVA polarizing film was sequentially subjected to alcohol washing and surface treatment with silane coupling agent dilution solution.

[0016] Preferably, the solvent for the silane coupling agent diluent is an ethanol-water mixture or an acetone-water mixture;

[0017] The mass concentration of the silane coupling agent in the diluted solution is 1-5%.

[0018] Preferably, the coating is one or more of spin coating, spray coating, scraping coating, brush coating, dip coating, roller coating and slot coating.

[0019] Preferably, the curing temperature is 10–50°C and the curing time is 1–3 hours.

[0020] This invention provides the application of the above-mentioned PVA polarizing film coated with silicone resin in the field of electronic displays.

[0021] This invention provides a PVA polarizing film coated with silicone resin, comprising a PVA polarizing film and a silicone resin coating attached to the surface of the PVA polarizing film. The raw materials for the silicone resin coating include silicone resin and a silane coupling agent. Silicone resin is a highly cross-linked, network-structured polysiloxane. This invention uses silicone resin and a silane coupling agent to form a silicone resin coating on the surface of the PVA polarizing film, which can impart good heat and moisture resistance to the PVA polarizing film without reducing its light transmittance. The use of the silane coupling agent not only promotes the curing of the silicone resin at room temperature, avoiding damage to the PVA polarizing film caused by high temperatures, but also acts as a medium to react with both the PVA polarizing film and the silicone resin, enhancing their bonding strength and further improving the water vapor barrier properties of the PVA polarizing film. Example results show that the water vapor transmission of the silicone resin-coated PVA polarizing film provided by this invention is 33.20–56.24 g / (m²). 2 • 24h), light transmittance is higher than 40%.

[0022] This invention provides a method for preparing the above-mentioned PVA polarizing film coated with silicone resin. This method is simple to operate, low in cost, and easy to achieve industrial mass production. Attached Figure Description

[0023] Figure 1 Preparation flow chart of the PVA polarizing film coated with silicone resin;

[0024] Figure 2 Water vapor permeation amount of the PVA polarizing film of Examples 1-3 and Comparative Example 1;

[0025] Figure 3 Light transmittance of the PVA polarizing film of Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0026] The present application provides a PVA polarizing film coated with silicone resin, comprising a PVA polarizing film and a silicone resin coating attached to the surface of the PVA polarizing film, wherein the raw material of the silicone resin coating comprises silicone resin and silane coupling agent.

[0027] In the present application, the thickness of the PVA polarizing film is preferably 20-50 μm, more preferably 25-40 μm; the source of the PVA polarizing film is preferably commercially available.

[0028] In the present application, the silicone resin preferably comprises one or more of phenyl silicone resin, methyl silicone resin, vinyl silicone resin and methyl phenyl silicone resin. In the present application, the source of the silicone resin is preferably commercially available.

[0029] In the present application, the silane coupling agent preferably comprises one or more of 3-aminopropyl triethoxysilane (KH550), glycidyl ether propyl trimethoxysilane (KH560), methacryloyl chloride propyl trimethoxysilane (KH570) and ethylene triethoxysilane (KH151); more preferably 3-aminopropyl triethoxysilane (KH550). In the present application, the source of the silane coupling agent is preferably commercially available.

[0030] In the present application, the mass of the silane coupling agent is preferably 1-10% of the mass of the silicone resin, more preferably 3-5%; further preferably 3%.

[0031] In the present application, the thickness of the silicone resin coating is preferably 5-50 μm, more preferably 20-45 μm.

[0032] The present application provides a preparation method of the above-mentioned PVA polarizing film coated with silicone resin, comprising the following steps:

[0033] Mixing the silicone resin with the silane coupling agent to obtain a mixed solution after defoaming;

[0034] Coating the mixed solution on the surface of the PVA polarizing film and curing to obtain the PVA polarizing film coated with silicone resin.

[0035] The present application mixes the silicone resin with the silane coupling agent, and obtains a mixed solution after defoaming. In the present application, the mixing method is preferably stirring mixing. In the present application, the defoaming method is preferably one or more of standing defoaming, temperature rising defoaming, vacuum defoaming and tin paste stirrer defoaming. The present application does not have special requirements for the specific defoaming method, and the above defoaming methods known to those skilled in the art can be used.

[0036] After obtaining the mixed solution, the present application coats the mixed solution on the surface of the PVA polarizing film, and performs curing to obtain a PVA polarizing film coated with silicone resin. In the present application, before coating, the PVA polarizing film is preferably pretreated, and the pretreatment preferably includes the following steps:

[0037] The PVA polarizing film is sequentially subjected to alcohol washing and silane coupling agent diluent surface treatment.

[0038] In the present application, the alcohol washing reagent is preferably anhydrous ethanol.

[0039] In the present application, the solvent of the silane coupling agent diluent is an ethanol-water mixed solvent or an acetone-water mixed solvent; the mass fraction of ethanol in the ethanol-water mixed solvent is preferably 95%; the mass fraction of acetone in the acetone-water mixed solvent is preferably 95%.

[0040] In the present application, the silane coupling agent preferably includes one or more of 3-aminopropyl triethoxysilane, glycidyl ether propyltrimethoxysilane, methacryloyl chloride propyltrimethoxysilane and ethylene triethoxysilane.

[0041] In the present application, the mass concentration of the silane coupling agent in the silane coupling agent diluent is preferably 1-5%, more preferably 1-3%, and further preferably 3%.

[0042] In the present application, the temperature of the silane coupling agent diluent surface treatment is preferably room temperature, and the time is preferably 2-5 min, more preferably 3-4 min.

[0043] In the present application, the coating is preferably one or more of spin coating, spraying, blade coating, brushing, dipping, roller coating and slot coating. The present application does not have special requirements for the specific coating method, and the above coating methods known to those skilled in the art can be used.

[0044] In the present application, the curing temperature is preferably 10-50°C, more preferably 20-30°C; and the curing time is preferably 1-3 h, more preferably 2-3 h.

[0045] In the present application, the preparation process of the PVA polarizing film coated with silicone resin is as shown in Figure 1 .

[0046] The present application provides the application of the above-mentioned PVA polarizing film coated with silicone resin in the field of electronic display. In the present application, the PVA polarizing film coated with silicone resin is preferably applied in a polarizing sheet.

[0047] The PVA polarizing film coated with silicone resin, the preparation method and the application thereof provided by the present application are described in detail below in combination with examples, but they cannot be understood as the limitation of the protection scope of the present application.

[0048] Example 1

[0049] 95% of anhydrous ethanol and 5% of deionized water were configured into an ethanol-water mixed solvent in terms of mass fraction, and 3% of a diluted solution of silane coupling agent KH550 was prepared by adding the KH550 under stirring, and hydrolyzed for 5 min at room temperature;

[0050] The surface of the PVA polarizing film (25 μm, Xiangfuxing Technology Co., Ltd.) was wiped with anhydrous ethanol, and the diluted and hydrolyzed KH550 solution was coated on the surface of the PVA polarizing film, and dried at room temperature for 2 min;

[0051] 97% of methylphenyl silicone resin and 3% of silane coupling agent KH550 were mixed and stirred uniformly in terms of mass fraction, and bubbles were removed;

[0052] The silicone resin was coated on the PVA polarizing film, and the PVA polarizing film with a silicone resin coating layer with a thickness of 20 μm was obtained after curing at 25°C for 2 h.

[0053] Example 2

[0054] 95% of anhydrous ethanol and 5% of deionized water were configured into an ethanol-water mixed solvent in terms of mass fraction, and 5% of a diluted solution of silane coupling agent KH550 was prepared by adding the KH550 under stirring, and hydrolyzed for 5 min at room temperature;

[0055] The surface of the PVA polarizing film (25 μm, Xiangfuxing Technology Co., Ltd.) was wiped with anhydrous ethanol, and the diluted and hydrolyzed KH550 solution was coated on the surface of the PVA polarizing film, and dried at room temperature for 2 min;

[0056] 99% of methylphenyl silicone resin and 1% of silane coupling agent KH550 were mixed and stirred uniformly in terms of mass fraction, and bubbles were removed;

[0057] The silicone resin was coated on the PVA polarizing film, and the PVA polarizing film with a silicone resin coating layer with a thickness of 20 μm was obtained after curing at 25°C for 2 h.

[0058] Example 3

[0059] 95% of anhydrous ethanol and 5% of deionized water were configured into an ethanol-water mixed solvent in terms of mass fraction, and 1% of a diluted solution of KH550 was prepared by stirring and adding a silane coupling agent KH550, and hydrolysis was performed at room temperature for 5 min;

[0060] The surface of a PVA polarizing film (25 μm, Xiangfuxing Technology Co., Ltd.) was wiped with anhydrous ethanol, and the diluted and hydrolyzed KH550 solution was coated on the surface of the PVA polarizing film, and was left to dry at room temperature for 2 min;

[0061] 95% of a methylphenyl silicone resin and 5% of a silane coupling agent KH550 were mixed and stirred uniformly in terms of mass fraction, and bubbles were removed;

[0062] The silicone resin was coated on the PVA polarizing film, and the PVA polarizing film with a silicone resin coating layer with a thickness of 45 μm was obtained after curing at 25 °C for 2 h.

[0063] Comparative Example 1

[0064] The same original PVA polarizing film (25 μm, Xiangfuxing Technology Co., Ltd.) as that of the above example material was used, the surface was wiped with anhydrous ethanol, and was left to dry.

[0065] Performance test

[0066] The light transmittance and water vapor transmission amount of the PVA polarizing film prepared in each example and comparative example were tested, and the results are shown in Figures 2-3 and Table 1. Among them, the light transmittance was tested by an ultraviolet-visible spectrophotometer; and the water vapor transmission amount was tested by a water vapor transmission rate tester.

[0067] Table 1 Light transmittance and water vapor transmission amount of the PVA polarizing film prepared in each example and comparative example

[0068] Transmittance (%) Water vapor transmission (g / (m 2 ·24h) Example 1 43.60 46.48 Example 2 42.68 56.24 Example 3 43.49 33.20 Comparative Example 1 43.98 212.08

[0069] From Figures 2-3 and Table 1, it can be seen that the PVA polarizing film coated with a silicone resin provided by the present application can greatly improve the heat and humidity resistance of the PVA polarizing film without damaging the light transmittance of the PVA polarizing film.

[0070] The above only describes the preferred embodiments of the present application, and it should be noted that those of ordinary skill in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A PVA polarizing film coated with a silicone resin, comprising a PVA polarizing film and a silicone resin coating attached to the surface of the PVA polarizing film, characterized in that: The raw material of the organic silicon resin coating is two components: organic silicon resin and silane coupling agent; the organic silicon resin is methyl phenyl silicon resin; the silane coupling agent is KH550; the mass of the silane coupling agent is 1-10% of the mass of the organic silicon resin; The preparation method of the PVA polarizing film comprises the following steps: Mixing the organic silicon resin and the silane coupling agent, and removing bubbles to obtain a mixed solution; Coating the mixed solution on the surface of the PVA polarizing film, and curing to obtain the PVA polarizing film coated with the organic silicon resin; before coating, the PVA polarizing film is pretreated, and the pretreatment comprises the following steps: sequentially performing alcohol washing and silane coupling agent diluent surface treatment on the PVA polarizing film, and the solvent of the silane coupling agent diluent is an ethanol-water mixed solvent or an acetone-water mixed solvent; 95% of anhydrous ethanol and 5% of deionized water are configured into the ethanol-water mixed solvent; the mass concentration of the silane coupling agent in the silane coupling agent diluent is 1-5%.

2. The coated organosilicon resin PVA polarizing film according to claim 1, characterized by, The thickness of the organic silicon resin coating is 5-50 microns; The thickness of the PVA polarizing film is 20-50 microns.

3. The coated organosilicon resin PVA polarizing film according to claim 1, characterized by, The coating is one or several of spin coating, spray coating, blade coating, brush coating, dip coating, roller coating and slit coating.

4. The PVA polarizing film coated with a silicone resin according to claim 1, characterized by, The curing temperature is 10-50 DEG C, and the time is 1-3 hours. 5.The application of the PVA polarizing film coated with the organic silicon resin in the electronic display field according to any one of claims 1-4.

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