A method for producing a polymethyl methacrylate / polycarbonate polarizing plate

Abstract

The application discloses a preparation method of a polymethyl methacrylate / polycarbonate polarizing plate, and the structure of the polymethyl methacrylate / polycarbonate polarizing plate comprises a base film which takes PMMA and PC as main raw materials, a polyvinyl alcohol film arranged on the upper surface of the base film, an optical compensation film arranged on the upper surface of the polyvinyl alcohol film, a haze adjusting layer arranged on the upper surface of the optical compensation film and a light-transmitting electrode layer arranged on the upper surface of the haze adjusting layer. The base film takes the polymethyl methacrylate which is crosslinked and grafted with polycarbonate and is toughened and modified by a specific amount of aluminum oxide as the main raw material, replaces the traditional TAC, improves the mechanical properties and tensile properties of the base film, reduces the production cost of the polarizing plate, reduces the thickness of the polarizing plate and enhances the light-transmitting capacity of the polarizing plate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polarizing plate preparation, and more particularly, the present application relates to a preparation method of polymethyl methacrylate / polycarbonate polarizing plate. BACKGROUND

[0002] The full name of the polarizing plate is polarized light plate. The imaging of liquid crystal display must rely on polarized light. All liquid crystal displays have two polarized light plates in front and back, which are closely attached to the liquid crystal glass to form a liquid crystal plate with a thickness of about 1mm. If any one of the polarized light plates is missing, the liquid crystal plate cannot display images. 3D glasses use this principle. The function of the polarizing plate is to change natural light into linearly polarized light. Natural light is emitted by individual atoms independently, so the direction is divergent in all directions. The electric vector of such light is uniformly distributed in all directions. If the surface of the LED liquid crystal display panel is not covered with a polarizing plate, the human eye cannot obtain complete video images. The polarizing plate causes a relative phase delay between the two mutually perpendicular linearly polarized lights of the polarized light, thereby changing the polarization state of the light. The commonly used polarizing plate mainly includes the following structure: two TAC (triacetyl cellulose) films on both sides, and a PVA (polyvinyl alcohol) film between the two TAC films. However, TAC is expensive, and the polarizing plate after film formation has poor tensile properties, and the thickness of the polarizing plate is relatively thick, resulting in poor light transmittance of the polarizing plate. The light transmittance of the polarizing plate using TAC as the main raw material is about 89%, which still has a great room for improvement. PMMA (polymethyl methacrylate) is a high molecular polymer, also known as acrylic or organic glass, which has high transparency, low price, and is easy to machine, etc. It is a conventional substitute material for glass. At present, the thickness of the polarizing plate using PMMA as the main raw material is 80-100μm, and the haze is less than 1.5%. Foreign countries have relatively mature technology using PMMA as the main material of the polarizing plate base film, while domestic countries still lack related mature technology and industrialization use. Therefore, it is necessary to explore a preparation process of the polarizing plate using PMMA as the main raw material. SUMMARY

[0003] An object of the present application is to solve at least the above problems and / or defects, and to provide at least the advantages to be described later.

[0004] To achieve these objects and other advantages in accordance with the present application, a polymethyl methacrylate / polycarbonate polarizing plate is provided, comprising:

[0005] a base film using PMMA and PC as the main raw materials;

[0006] a polyvinyl alcohol film disposed on the upper surface of the base film;

[0007] an optical compensation film disposed on the upper surface of the polyvinyl alcohol film;

[0008] a haze adjusting layer disposed on an upper surface of the optical compensation film;

[0009] a light-transmitting electrode layer disposed on an upper surface of the haze adjusting layer.

[0010] Preferably, the raw material of the base film comprises, by weight parts, 120-140 parts of toughened modified PMMA, 60-80 parts of PC, 4-12 parts of polystyrene, 15-18 parts of polyvinyl chloride, 0.8-1.2 parts of 2,4-dihydroxybenzophenone, 0.5-1 part of a toughening agent, 0.2-0.4 parts of a dispersing agent, and 0.1-0.4 parts of polydimethylsiloxane.

[0011] Preferably, the optical compensation film is a cellulose acetate film with an acetyl substitution degree of 2.45.

[0012] Preferably, the toughening agent is phthalate.

[0013] Preferably, the dispersing agent is sodium stearate or potassium stearate.

[0014] Preferably, the haze adjusting layer is a polymer dispersed liquid crystal film.

[0015] Preferably, the light-transmitting electrode layer is an indium tin oxide film.

[0016] Preferably, the modification method of the toughened modified PMMA comprises: uniformly mixing PMMA raw material powder and polycarbonate raw material powder at a mass ratio of 60-80:1 to obtain a mixture, feeding the mixture into a melt kneader, heating to 240-280℃, reacting for 40-80 min, adding 2.5-8% of aluminum oxide powder based on the mass of the PMMA raw material powder, the average particle size of the aluminum oxide powder being 0.04 μm, melt mixing for 30-100 min to obtain a melt product; cooling the melt product to 30-60℃, ball milling the melt product into a powder with a particle size of 0.2-100 μm, mixing the melt product powder with tetrahydrofuran at a mass-volume ratio of 1.0 g:60 mL, and pouring into a heated dissolution device, heating to reflux for 1-3 h, after the melt product powder is completely dissolved, pouring into ethyl acetate, the amount of ethyl acetate being one-sixth of the volume of tetrahydrofuran, stirring at a speed of 200 r / min for 2-4 h, filtering, washing the solid powder with ethyl acetate several times, and drying at a temperature of 60-90℃ to obtain the toughened modified PMMA powder.

[0017] A preparation method of a polymethyl methacrylate / polycarbonate polarizing sheet, comprising the following steps:

[0018] Step one, the toughened modified PMMA powder, PC particles, polystyrene particles, polyvinyl chloride, 2,4-dihydroxybenzophenone, toughening agent, dispersing agent and polydimethylsiloxane are mixed and then put into a double screw extruder for melt plasticizing extrusion, the extrusion temperature is 160-200℃, the mixed raw materials are extruded into a sheet film material;

[0019] Step two, taking polyvinyl alcohol particles as raw materials, the polyvinyl alcohol particles are extruded into a polyvinyl alcohol film, the sheet film material obtained in step one is stretched, the polyvinyl alcohol film is laminated on one side of the sheet film material, and the optical compensation film is laminated on the surface of the polyvinyl alcohol film to obtain a three-layer film material of base film-polyvinyl alcohol film-optical compensation film.

[0020] Step three, the haze adjusting layer is coated on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0021] Step four, the light-transmitting electrode layer is deposited on the surface of the haze adjusting layer; the refractive index and thickness are detected, and the preparation of the polymethyl methacrylate / polycarbonate polarizing plate is completed.

[0022] Preferably, in step four, the method for depositing the light-transmitting electrode layer on the surface of the haze adjusting layer comprises: direct current magnetron sputtering is performed with ITO oxide as a target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide is 9:1, the purity of In2O3 and SnO2 is both 99.99%, the distance from the target material to the haze adjusting layer during plating is 10cm, the base vacuum degree is 2.5x10 -6 Torr, the sputtering vacuum degree is 1.2x10 -3 ~3.0x10 -3 Torr, the base temperature is 25℃, argon and oxygen are introduced into the plating machine, the argon flow is 150-400sccm, the oxygen flow is 8-16sccm, the sputtering power is 2-10kW, and the film material walking speed is 1.0-3.5m / min.

[0023] The present application at least includes the following beneficial effects: the base film of the polymethyl methacrylate / polycarbonate polarizing plate provided by the present application uses polymethyl methacrylate and polycarbonate as main raw materials, replaces the traditional TAC (triacetyl cellulose) with polymethyl methacrylate and polycarbonate, not only reduces the production cost of the polarizing plate, but also reduces the process technology of pasting a layer of TAC on the surface of the PVA (polyvinyl alcohol) film, does not need to be cut again, improves the effective use area of the polarizing plate, and effectively reduces the production cost of the polarizing plate.

[0024] The PMMA (polymethyl methacrylate) raw material used in the present application is a toughened modified polymethyl methacrylate, and in the improvement process, a specific proportion of polycarbonate and polymethyl methacrylate is used for pre-crosslinking grafting, which enhances the compatibility of polymethyl methacrylate and polycarbonate, makes the subsequent toughened modified polymethyl methacrylate and polycarbonate blend more uniform, the transparency of the synthesized sheet film material is higher, and the light transmittance of the base film is increased; then a specific proportion of aluminum oxide powder is dispersed in the crosslinked system, the mechanical properties of polymethyl methacrylate are improved, thereby the toughness of the sheet film material after film forming is enhanced, so that in the subsequent stretching process, the sheet film material can be stretched together with the polyvinyl alcohol film-optical compensation film into a base film-polyvinyl alcohol film-optical compensation film three-layer film material with greater strength and thinner thickness.

[0025] Other advantages, objects, and features of the present application will be understood by those skilled in the art from the following description, and will be appreciated by those skilled in the art upon reading and understanding the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A partial cross-sectional structure diagram of the polymethyl methacrylate / polycarbonate polarizing plate in Example 1. DETAILED DESCRIPTION

[0027] The present application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present application according to the description.

[0028] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0029] Example 1

[0030] The partial cross-sectional structure diagram of the polymethyl methacrylate / polycarbonate polarizing plate provided in the present embodiment is shown in Figure 1 , which comprises:

[0031] a base film 1, which uses PMMA and PC as main raw materials;

[0032] a polyvinyl alcohol film 2, which is arranged on the upper surface of the base film 1;

[0033] a cellulose acetate film with an acetyl substitution degree of 2.45 is used as an optical compensation film 3, which is arranged on the upper surface of the polyvinyl alcohol film 2; a polymer dispersed liquid crystal film is used as a haze adjusting layer 4, which is arranged on the upper surface of the optical compensation film 3; an indium tin oxide film 5, which is arranged on the upper surface of the haze adjusting layer 4.

[0034] The preparation method of the polymethyl methacrylate / polycarbonate polarizing plate of the embodiment comprises the following steps:

[0035] Step one, 12 kg of toughened modified PMMA powder, 6 kg of PC particles, 0.4 kg of polystyrene particles, 1.5 kg of polyvinyl chloride, 0.08 kg of 2,4-dihydroxybenzophenone, 0.05 kg of phthalate, 0.02 kg of sodium stearate and 0.01 kg of polydimethylsiloxane are mixed and then put into a double screw extruder for melt plasticizing extrusion, the extrusion temperature is 160℃, and the mixed raw materials are extruded into a sheet film material; wherein the modification method of the toughened modified PMMA powder is: 60 kg of PMMA raw powder and 1 kg of polycarbonate raw powder are uniformly mixed to obtain a mixture, the mixture is put into a melt mixer, heated to 240℃, reacted for 40 min, 1.5 kg of aluminum oxide powder is added, the average particle size of the aluminum oxide powder is 0.04 μm, and the melt mixing is carried out for 30 min to obtain a melt product; the melt product is cooled to 30℃, the melt product is ball milled into a powder, the powder particle size is 0.2-50 μm, the melt product powder is mixed with tetrahydrofuran at a mass-volume ratio of 1.0 g:60 mL, and then poured into a heated dissolution device, heated to reflux for 1 h, after the melt product powder is completely dissolved, pour into ethyl acetate, the amount of ethyl acetate is one sixth of the volume of tetrahydrofuran, stir at a speed of 200 r / min for 2 h, then filter, wash the solid powder with ethyl acetate for several times, dry at a temperature of 60℃ to obtain the toughened modified PMMA powder.

[0036] Step two, take polyvinyl alcohol particles as raw materials, extrude the polyvinyl alcohol particles into a polyvinyl alcohol film, stretch the sheet film material obtained in step one, laminate the polyvinyl alcohol film on one side of the sheet film material, and laminate the optical compensation film on the surface of the polyvinyl alcohol film to obtain a three-layer film material of base film-polyvinyl alcohol film-optical compensation film;

[0037] Step three, the haze adjusting layer is coated on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0038] Step four, deposit the indium tin oxide film on the surface of the haze adjusting layer, the specific method comprising: direct current magnetron sputtering is carried out with ITO oxide as target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide is 9:1, the purity of In2O3 and SnO2 is 99.99%, the distance between the target material and the haze adjusting layer is 10 cm during plating, the base vacuum degree is 2.5×10 -6 Torr, and the sputtering vacuum degree is 1.2×10 -3Torr, the substrate temperature is 25℃, the argon and oxygen are introduced into the coating machine, the argon flow is 150sccm, the oxygen flow is 8sccm, the sputtering power is 2kW, the film material walking speed is 1.0m / min; the refractive index and thickness detection are carried out, and the preparation of the polymethyl methacrylate / polycarbonate polarizing plate is completed.

[0039] Example 2

[0040] The structure of the polymethyl methacrylate / polycarbonate polarizing plate of the present example is the same as that of example 1, and the preparation method comprises the following steps:

[0041] Step one, 13kg of toughened modified PMMA powder, 7kg of PC particles, 0.6kg of polystyrene particles, 1.6kg of polyvinyl chloride, 0.1kg of 2,4-dihydroxybenzophenone, 0.08kg of phthalate, 0.03kg of sodium stearate and 0.02kg of polydimethylsiloxane are mixed and then put into a twin-screw extruder for melt plasticizing extrusion, and the extrusion temperature is 180℃. The mixed raw materials are extruded into a sheet film material; wherein the modification method of the toughened modified PMMA powder is as follows: 70kg of PMMA raw powder and 1kg of polycarbonate raw powder are uniformly mixed to obtain a mixture, the mixture is put into a melt mixer, heated to 260℃, reacted for 70min, 4.2kg of aluminum oxide powder with an average particle size of 0.04μm is added, and the melt mixture is mixed for 60min to obtain a melt product; the melt product is cooled to 50℃, the melt product is ball milled into a powder with a particle size of 0.2-100μm, the melt product powder is mixed with tetrahydrofuran at a mass-volume ratio of 1.0g:60mL, and then poured into a heated dissolution device, heated to reflux for 1-3h, after the melt product powder is completely dissolved, poured into ethyl acetate, the amount of ethyl acetate is one-sixth of the volume of tetrahydrofuran, stirred at a speed of 200r / min for 3h, filtered, the solid powder is washed with ethyl acetate for several times, dried at 80℃ to obtain the toughened modified PMMA powder.

[0042] Step two, polyvinyl alcohol particles are used as raw materials, the polyvinyl alcohol particles are extruded into a polyvinyl alcohol film, the sheet film material obtained in step one is stretched, a polyvinyl alcohol film is laminated on one side of the sheet film material, and an optical compensation film is laminated on the surface of the polyvinyl alcohol film to obtain a three-layer film material of base film-polyvinyl alcohol film-optical compensation film;

[0043] Step three, the haze adjusting layer is coated on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0044] Step four, depositing an indium tin oxide film on the surface of the haze adjusting layer, the specific method comprising: direct current magnetron sputtering with ITO oxide as the target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide being 9:1, the purity of In2O3 and SnO2 both being 99.99%, the distance from the target material to the haze adjusting layer being 10 cm during film plating, the base vacuum degree being 2.5 x 10 -6 Torr, the sputtering vacuum degree being 12.0 x 10 -3 Torr, the base temperature being 25℃, the argon gas flow being 300 sccm, the oxygen gas flow being 12 sccm, the sputtering power being 6 kW, the film material walking speed being 2.5 m / min; detecting the refractive index and thickness, and the preparation of the polymethyl methacrylate / polycarbonate polarizing plate is completed.

[0045] Example 3

[0046] The polymethyl methacrylate / polycarbonate polarizing plate of the present example has the same structure as that of Example 1, and the preparation method comprises the following steps:

[0047] Step one, mixing 14 kg of toughened modified PMMA powder, 8 kg of PC particles, 1.2 kg of polystyrene particles, 1.8 kg of polyvinyl chloride, 0.12 kg of 2,4-dihydroxybenzophenone, 0.1 kg of phthalate, 0.04 kg of potassium stearate and 0.04 kg of polydimethylsiloxane, and then feeding them into a twin-screw extruder for melt plasticizing extrusion, the extrusion temperature being 200℃, and the mixed raw materials being extruded into a sheet film material; wherein the modification method of the toughened modified PMMA powder is as follows: uniformly mixing 80 kg of PMMA raw material powder and 1 kg of polycarbonate raw material powder to obtain a mixture, feeding the mixture into a melt mixer, heating to 280℃, reacting for 80 min, adding 6.4 kg of aluminum oxide powder accounting for 6.4% of the mass of the PMMA raw material powder, the average particle size of the aluminum oxide powder being 0.04 μm, melt mixing for 100 min to obtain a melt product; cooling the melt product to 60℃, ball milling the melt product into a powder with a particle size of 0.2-800 μm, mixing the melt product powder with tetrahydrofuran at a mass-volume ratio of 1.0 g:60 mL, and then pouring into a heated dissolution device, heating to reflux for 3 h, after the melt product powder is completely dissolved, pouring into ethyl acetate, the amount of ethyl acetate being one-sixth of the volume of tetrahydrofuran, stirring at a speed of 200 r / min for 4 h, and then filtering, washing the solid powder with ethyl acetate several times, and drying at a temperature of 90℃ to obtain the toughened modified PMMA powder.

[0048] Step two, taking polyvinyl alcohol particles as raw materials, extruding the polyvinyl alcohol particles into a polyvinyl alcohol film, stretching the sheet film material obtained in step one, laminating a polyvinyl alcohol film on one side of the sheet film material, laminating an optical compensation film on the surface of the polyvinyl alcohol film, and obtaining a three-layer film material of base film-polyvinyl alcohol film-optical compensation film;

[0049] Step three, coating the haze adjusting layer on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0050] Step four, depositing an indium tin oxide film on the surface of the haze adjusting layer, the specific method comprising: direct current magnetron sputtering with ITO oxide as target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide is 9:1, the purity of In2O3 and SnO2 is 99.99%, the distance from the target material to the haze adjusting layer is 10 cm during film plating, the base vacuum degree is 2.5x10 -6 Torr, the sputtering vacuum degree is 3.0x10 -3 Torr, the substrate temperature is 25℃, argon and oxygen are introduced into the film plating machine, the argon flow is 400sccm, the oxygen flow is 16sccm, the sputtering power is 10kW, and the film material walking speed is 3.5m / min; the refractive index and thickness are detected, and the polymethyl methacrylate / polycarbonate polarizing plate is prepared.

[0051] Comparative Example 1

[0052] The polymethyl methacrylate / polycarbonate polarizing plate provided by the comparative example has the same structure as that of Example 1, and the preparation method comprises the following steps:

[0053] Step one, mixing 12kg of PMMA powder, 6kg of PC particles, 0.4kg of polystyrene particles, 1.5kg of polyvinyl chloride, 0.08kg of 2,4-dihydroxybenzophenone, 0.05kg of phthalate, 0.02kg of sodium stearate and 0.01kg of polydimethylsiloxane, and then putting them into a twin-screw extruder for melt plasticizing extrusion, the extrusion temperature is 160℃, and the mixed raw materials are extruded into sheet film material;

[0054] Step two, taking polyvinyl alcohol particles as raw materials, extruding the polyvinyl alcohol particles into a polyvinyl alcohol film, stretching the sheet film material obtained in step one, laminating a polyvinyl alcohol film on one side of the sheet film material, laminating an optical compensation film on the surface of the polyvinyl alcohol film, and obtaining a three-layer film material of base film-polyvinyl alcohol film-optical compensation film;

[0055] Step three, coating the haze adjusting layer on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0056] Step four, depositing an indium tin oxide film on the surface of the haze adjusting layer, the specific method comprising: performing direct current magnetron sputtering with ITO oxide as the target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide being 9:1, the purity of In2O3 and SnO2 both being 99.99%, the distance from the target material to the haze adjusting layer being 10 cm during film plating, the base vacuum degree being 2.5 x 10 -6 Torr, the sputtering vacuum degree being 1.2 x 10 -3 Torr, the substrate temperature being 25°C, argon and oxygen being introduced into the film plating machine, the argon flow being 150 sccm, the oxygen flow being 8 sccm, the sputtering power being 2 kW, and the film material walking speed being 1.0 m / min; the refractive index and thickness are detected, and the preparation of the polymethyl methacrylate / polycarbonate polarizing sheet is completed.

[0057] Comparative Example 2

[0058] The polymethyl methacrylate / polycarbonate polarizing sheet provided by the present comparative example has the same structure as that of Example 1, and the preparation method comprises the following steps:

[0059] Step one, mixing 13 kg of PMMA powder, 7 kg of PC particles, 0.6 kg of polystyrene particles, 1.6 kg of polyvinyl chloride, 0.1 kg of 2,4-dihydroxybenzophenone, 0.08 kg of phthalate, 0.03 kg of sodium stearate, and 0.02 kg of polydimethylsiloxane, and then feeding them into a twin-screw extruder for melt plasticizing extrusion, the extrusion temperature being 180°C, and the mixed raw materials being extruded into a sheet-shaped film material;

[0060] Step two, extruding polyvinyl alcohol particles into a polyvinyl alcohol film, and stretching the sheet-shaped film material obtained in Step one, laminating the polyvinyl alcohol film on one side of the sheet-shaped film material, and laminating an optical compensation film on the surface of the polyvinyl alcohol film to obtain a three-layer film material of base film-polyvinyl alcohol film-optical compensation film;

[0061] Step three, coating the haze adjusting layer on the surface of the optical compensation film of the three-layer film material of base film-polyvinyl alcohol film-optical compensation film in a coating manner;

[0062] Step four, depositing an indium tin oxide film on the surface of the haze adjusting layer, the specific method comprising: performing direct current magnetron sputtering with ITO oxide as the target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide being 9:1, the purity of In2O3 and SnO2 both being 99.99%, the distance from the target material to the haze adjusting layer being 10 cm during film plating, the base vacuum degree being 2.5 x 10 -6 Torr, the sputtering vacuum degree being 12.0 x 10 -3Torr, the substrate temperature is 25℃, the argon and oxygen are introduced into the coating machine, the argon flow is 300sccm, the oxygen flow is 12sccm, the sputtering power is 6kW, the film material walking speed is 2.5m / min; the refractive index and thickness detection is carried out, and the polymethyl methacrylate / polycarbonate polarizing plate preparation is completed.

[0063] The thickness of the sheet-shaped film material in Examples 1-3 and Comparative Examples 1-2 is 1mm, and the specific method for laminating the sheet-shaped film material, the polyvinyl alcohol film and the optical compensation film into a three-layer film material of base film-polyvinyl alcohol film-optical compensation film includes: using coaxial optical oblique stretching, stretching the sheet-shaped film material to a film at 55° under the condition of 120℃, and laminating the polyvinyl alcohol film and the optical compensation film on the film in turn by roll-to-roll lamination after drying, to form a three-layer film material of base film-polyvinyl alcohol film-optical compensation film. The film thickness, light transmittance T, haze H and polarization degree P of the samples of Examples 1-3 and Comparative Examples 1-2 are measured respectively, and the following table is obtained:

[0064] Film thickness (pm) Transmittance (%) Haze (%) Degree of polarization (%) Example 1 53 90.2 0.45 99.1 Example 2 55 90.9 0.46 98.5 Example 3 56 90.5 0.45 98.7 Comparative Example 1 88 87.3 1.10 97.2 Comparative Example 2 86 87.0 1.15 97.6

[0065] The thickness of each layer of the polarizing plate in Examples 1-4 and Comparative Examples 1-2 is shown in the following table:

[0066]

[0067]

[0068] As can be seen from the above two tables, the polymethyl methacrylate / polycarbonate polarizing plate prepared in Examples 1-3 has better mechanical properties of the base film because the toughened modified PMMA is used as the main raw material, and a base film with thinner thickness and higher light transmittance can be obtained, so that the thickness, light transmittance, haze and polarization degree of the prepared polymethyl methacrylate / polycarbonate polarizing plate are all better than those of the polarizing plates prepared in Comparative Examples 1 and 2.

[0069] The polarizing degree test experiment of the polarizer needs to use a spectrophotometer instrument. The performance indexes that need to be tested for colorless and transparent materials usually include transmittance and haze. The transmittance is the light transmittance of a transparent or translucent material, expressed as the percentage of the light flux that transmits through the material to the incident light flux. A parallel light is vertically irradiated onto the sample, and the percentage of the light flux I that transmits through the sample to the incident light flux I0 is the transmittance T=I / I0. The test instrument is a haze meter or a luminometer. The polarizing degree P is defined as P=(I∥-I) / (I∥+I), wherein I∥ and I respectively represent the transmitted light intensities when the two polarizers are combined and the transmission axes are parallel and perpendicular. The haze is the cloudy or turbid appearance of a transparent or translucent material due to light scattering inside or on the surface, expressed as the percentage of the scattered light flux to the light flux that transmits through the material. A parallel light is vertically irradiated onto the sample, and the percentage of the scattered light flux T d which is greater than 2.5 from the incident direction to the part of the parallel light to the light flux T2 that transmits through the sample, is the haze H(%)=(T4 / T2)-(T3 / T1)×100≈(T4 / T2)×100. The test instrument is a haze meter, and the sample surface is required to be free of pollution and scratches.

[0070] The number of devices and the scale of processing described herein are used to simplify the description of the present application. The applications, modifications and variations of the present application that are apparent to those skilled in the art are obvious.

[0071] Although the embodiments of the present application have been disclosed as above, they are not limited to the applications and embodiments listed in the specification, and can be fully applied to various fields suitable for the present application. Those skilled in the art can easily make other modifications, and therefore the present application is not limited to the specific details and the figures shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A polymethyl methacrylate / polycarbonate polarizing plate characterized by, It comprises: a base film comprising PMMA and PC; a polyvinyl alcohol film arranged on the upper surface of the base film; an optical compensation film arranged on the upper surface of the polyvinyl alcohol film; a haze adjusting layer arranged on the upper surface of the optical compensation film; a light-transmitting electrode layer arranged on the upper surface of the haze adjusting layer; the light-transmitting electrode layer is an indium tin oxide film; the raw material of the base film comprises, by weight parts, 120-140 parts of toughened modified PMMA, 60-80 parts of PC, 4-12 parts of polystyrene, 15-18 parts of polyvinyl chloride, 0.8-1.2 parts of 2,4-dihydroxybenzophenone, 0.5-1 part of a toughening agent, 0.2-0.4 parts of a dispersing agent, and 0.1-0.4 parts of polydimethylsiloxane; the modification method of the toughened modified PMMA comprises: uniformly mixing PMMA raw material powder and polycarbonate raw material powder according to a mass ratio of 60-80:1 to obtain a mixture, feeding the mixture into a melt kneader, heating to 240-280℃, reacting for 40-80min, adding 2.5-8% of aluminum oxide powder based on the mass of the PMMA raw material powder, the average particle size of the aluminum oxide powder being 0.04μm, melt mixing for 30-100min to obtain a melt product; cooling the melt product to 30-60℃, ball milling the melt product into powder with a particle size of 0.2-100μm, mixing the melt product powder with tetrahydrofuran at a mass-volume ratio of 1.0g:60mL, and pouring into a heated dissolving device, heating to reflux for 1-3h, after the melt product powder is completely dissolved, pouring into ethyl acetate, the amount of ethyl acetate being one-sixth of the volume of tetrahydrofuran, stirring at a speed of 200r / min for 2-4h, filtering, washing the solid powder with ethyl acetate several times, and drying at a temperature of 60-90℃ to obtain toughened modified PMMA powder.

2. The polymethyl methacrylate / polycarbonate polarizing plate according to claim 1, wherein The optical compensation film is a cellulose acetate film with an acetyl substitution degree of 2.

45.

3. The polymethyl methacrylate / polycarbonate polarizing plate according to claim 1, wherein The toughening agent is phthalate.

4. The polymethyl methacrylate / polycarbonate polarizing plate of claim 1, wherein The dispersing agent is sodium stearate or potassium stearate.

5. The polymethyl methacrylate / polycarbonate polarizer according to claim 1, wherein The haze adjusting layer is a polymer dispersed liquid crystal film.

6. A process for producing a polymethyl methacrylate / polycarbonate polarizing plate as claimed in any one of claims 1 to 5, characterized by, It comprises the following steps: Step one, mixing toughened modified PMMA powder, PC particles, polystyrene particles, polyvinyl chloride, 2,4-dihydroxybenzophenone, a toughening agent, a dispersing agent, and polydimethylsiloxane, and feeding into a twin-screw extruder for melt plasticizing extrusion, the extrusion temperature being 160-200℃, and the mixed raw material being extruded into a sheet-shaped film material; Step two, using polyvinyl alcohol particles as raw material, extruding the polyvinyl alcohol particles into a polyvinyl alcohol film, stretching the sheet-shaped film material obtained in step one, laminating the polyvinyl alcohol film on one side of the sheet-shaped film material, laminating an optical compensation film on the surface of the polyvinyl alcohol film to obtain a base film-polyvinyl alcohol film-optical compensation film three-layer film material; Step three, coating the haze adjusting layer on the surface of the optical compensation film of the base film-polyvinyl alcohol film-optical compensation film three-layer film material in a coating manner; Step four, depositing the light-transmitting electrode layer on the surface of the haze adjusting layer; detecting the refractive index and thickness, and the preparation of the polymethyl methacrylate / polycarbonate polarizing plate is completed.

7. The method of producing a polymethyl methacrylate / polycarbonate polarizing plate according to claim 6, wherein The method for depositing the light-transmitting electrode layer on the surface of the haze-adjusting layer in step four comprises: direct current magnetron sputtering with ITO oxide as the target material, the mass fraction ratio of In2O3 and SnO2 in the ITO oxide is 9:1, the purity of In2O3 and SnO2 is both 99.99%, the distance from the target material to the haze-adjusting layer during plating is 10 cm, the base vacuum degree is 2.5×10 -6 Torr, the sputtering vacuum degree is 1.2×10 -3 ~3.0×10 -3 Torr, the base temperature is 25℃, argon and oxygen are introduced into the plating machine, the argon flow rate is 150-400sccm, the oxygen flow rate is 8-16sccm, the sputtering power is 2-10kW, and the film material walking speed is 1.0-3.5m / min.

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