TWI809385B - Recycling method of polarizer structure - Google Patents

Abstract

A method for recycling polarizer structures, which uses the deiodine purification process to peel off the PET protective film from the waste polarizer, dissolve the iodide ions in the PVA film, and condense the iodine gas to a purity of ≥99%. Potassium iodide; the non-PET material is made into solid fuel (SRF) to provide fuel for high energy efficiency boilers; the other PET material is made into PET plastic pellets with the aforementioned PET protective film layer to provide high utilization and Recycled polyester with high economic benefits; since the invention can process waste polarizers to obtain high-purity potassium iodide, solid fuel (SRF) and PET plastic pellets, the invention has the effects of reducing environmental pollution and recycling resources.

Description

Recycling method of polarizer structure

The invention relates to a recycling method, especially a method for recycling polarizer structures that can obtain high-purity potassium iodide, solid fuel, and PET plastic pellets through processing waste polarizers, thereby reducing environmental pollution and recycling resources.

Press, the polarizer is one of the basic parts of the liquid crystal display, which is a light plate that only allows light in a specific direction to pass through; therefore, in the process of making a liquid crystal display, it is necessary to use a polarizer at the top and bottom to place it in a staggered direction , so the light source produces a phase difference and presents different light and dark states to display subtitles or patterns. The structure of the polarizing plate is shown in Figure 1, including a release film layer 911, a PSA pressure-sensitive adhesive layer 912, an upper TAC film layer 913 (triacetate fiber), a PVA film layer 914 (polyvinyl alcohol), and a lower TAC film layer 914 (triacetate), and PET protective film layer 920. The most important polarizer of the polarizer is to use a polymer film with good light transmission (commonly used as PVA) to absorb iodine-based substances, so that iodine ions can diffuse into the PVA in the inner layer, and after slight heating, it can be stretched several times in length mechanically. After the PVA molecules are stretched by stress, the molecules are arranged in a consistent manner, so that the attached iodide ions also form long chains directionally, so it can absorb the electric field of the beam parallel to its arrangement direction, and let the electric field component of the beam perpendicular to the light direction pass through to achieve the effect of polarization .

Since the polarizer is a kind of composite material, it is difficult to recycle, so there are two main ways to dispose of the waste polarizer at present. One is to crush it and send it overseas for processing. However, due to regulations and cost considerations, the disposal method is becoming less and less common. Another way is to send it to an incinerator for incineration, but because iodide ions will produce a large amount of purple smoke after incineration at high temperature, causing residents to protest, so burying or incinerating waste polarizers will cause secondary environmental pollution, let alone polarized light. Plastic materials such as PET and TAC in the board have the potential of resource recycling.

The reason is that the main purpose of the present invention is to provide a method and equipment that can recycle the structures in waste polarizers, including iodide ions and plastic materials such as PET and TAC, so as to reduce environmental pollution and achieve resource recovery. The effect of reuse.

In order to achieve the above-mentioned purpose, the present invention recycles the structures in the discarded polarizing plate, and its processing method comprises the following steps: a. peeling off the PET protective film layer on the surface of a polarizing plate so that it can be removed from the polarizing plate Separation to form a PET protective film and a bare polarizer; b. crush the bare polarizer to form a powder; c. dissolve the adhesive and iodide ions in the powder with steam, and pressurize and stir the Powder to form a mixture; d. Condensate potassium iodide with a purity of ≥99% from the mixture for recycling and remanufacturing, and the mixture forms a non-iodine recycle; e. separate PET substances and non-PET substances from the non-iodine recycle; f. The non-PET material separated in step e. is made into solid fuel (SRF) after pressure filtration; g. The PET material separated in step e. and the PET protective film peeled off in step a. are passed through A liquid-phase viscosification of recycled polyester to make PET plastic pellets.

According to the features disclosed above, the step a. in the present invention includes peeling off the PET protective film layer on the surface of the discarded polarizing plate manually or mechanically.

According to the features disclosed above, the step b. in the present invention is to use a grinder to crush the bare polarizer plate.

According to the features disclosed above, the step c. in the present invention is to use a boiler to generate steam, and use a screw extruder to pressurize and stir the powder to form a mixture.

According to the feature disclosed above, the step d. in the present invention uses a condensation filter to condense the mixture formed in the step c. out of potassium iodide.

According to the feature disclosed before, in the present invention, this step e. is to use a centrifugal sorter to screen out the non-iodine recyclables including PVA (polyvinyl alcohol), TAC (triacetate fiber) and PET (polyethylene terephthalic acid). Diol) and other substances with different specific gravity, wherein the PET is the PET substance, and the PVA and TAC are the non-PET substance.

According to the features disclosed above, the present invention further includes a first conduit and a second conduit, which are respectively arranged between the screw extruder and the condensation filter, and between the screw extruder and a centrifugal separator , so that the iodine gas and water vapor in the mixture enter the condensation filter from the diffusion port of the screw extruder through the first conduit, and the liquid mixture of non-iodine recovery is from the outlet of the screw extruder through the second Two conduits enter the centrifugal separator.

According to the features disclosed above, the step f. of the present invention is to use a filter press to make the non-PET material into the solid fuel (SRF). According to, SRF has low environmental impact, low fuel cost, and can be applied to high energy efficiency boilers and combustion facilities. Compared with coal, SRF as a fuel can achieve more carbon reduction effects. In addition, the use of SRF as fuel for industrial boilers can also reduce the load on existing incinerators.

According to the features disclosed above, in the step g. of the present invention, the liquid-phase viscosification of the regenerated polyester operation is to use a tank-type reaction tank to heat, stir, and vacuum the PET material and the PET protective film to make the polyester The molecular chain of the ester melt is depolymerized into a shorter chain, and then polymerized into a molecular chain of the desired length, thereby changing the intrinsic viscosity (I.V.), melting point and molecular chain structure of the polyester to suit the production of recycled polyester (PET). Reusing; and using a pelletizer to make PET plastic pellets from the recycled polyester (PET).

With the help of the features disclosed above, the present invention uses the iodine removal and purification process to peel off the PET protective film layer from the discarded polarizing plate, and dissolves the iodide ions in the PVA film layer; and then uses the classification recovery process to condense the iodine gas into Potassium iodide with a purity of ≥99% for further recycling; Non-PET materials are made into solid fuel (SRF) to provide fuel for high energy efficiency boilers; PET materials are combined with the aforementioned PET protective film layer to make PET plastic pellets , to provide recycled polyester with high utilization and high economic benefits; because the present invention can process waste polarizers to obtain potassium iodide, solid fuel (SRF) and PET plastic pellets with a purity>99% respectively, so the present invention has the advantages of reducing Environmental pollution and the effect of resource recovery and reuse.

First, please refer to FIG. 2 , which is the output framework for recycling waste polarizing plates 900 according to the present invention. The composition and structure of waste polarizing plates 900 include: a release film layer 911, a PSA pressure-sensitive adhesive layer 912, The upper TAC film layer 913, the PVA film layer 914, the lower TAC film layer 915, and the PET protective film layer 920; because the PET protective film layer 920 is attached to the surface of the discarded polarizer 900 to protect the polarizer from being scratched, Therefore, during the recycling operation, the PET protective film layer 920 can be peeled off first to form a bare polarizer plate 910; secondly, it is subjected to a deiodination purification process 810, the purpose of which is to dissolve the adhesive and iodine ions contained in it; Next, the present invention carries out the classified recovery process 820, including, condensing the iodine gas into potassium iodide 950 with a purity ≥ 99% for further recovery and remanufacturing; and the remainder can be separated into non-PET substances 960 and PET substances 970; non-PET substances 960 It can be made into solid fuel (SRF) 980 to provide fuel for boilers with high energy efficiency; PET material 970 and the aforementioned PET protective film 920 can be made into PET plastic pellets 990 to provide high utilization and high economic benefits of recycled polyester.

Please refer further to FIG. 3 , which is the structure of the recovery process steps of the present invention; wherein, the present invention uses the iodine removal purification process 810 and the classification recovery process 820 to carry out the recycling process of the waste polarizer 900, and the iodine removal purification process 810 is mainly to peel off the PET protective film layer 920 from the discarded polarizer 900, and dissolve the iodine ions in the PVA film layer 914; Polarizing plate bare plate 910 and a PET protective film 920; secondly, carry out crushing operation 812 so that polarizing plate bare plate 910 forms powder 930 according to it; 930 to form the mixture 940; moreover, the sorting and recycling process 820 is mainly to classify and recycle the structures of the discarded polarizing plate 900 so that they can be reused; Iodine gas 941 condenses potassium iodide 950; performing sieving operation 822 so that non-iodine recyclate 942 in the mixture 940 can be separated into non-PET material 960 and PET material 970; wherein, the non-PET material 960 can be obtained according to pressure filtration operation 823 to form a solid fuel (SRF) 980; and the PET material 970 and the PET protective film 920 are subjected to a liquid-phase thickened recycled polyester operation 824 to form PET plastic particles 990; therefore, the waste polarizer 900 is removed by the present invention After the iodine purification process 810 and the sorting recovery process 820, potassium iodide 950, solid fuel (SRF) 980 and PET plastic pellets 990 can be obtained, achieving the benefit of resource reuse.

Based on the above, the present invention recycles and reuses the structures in the discarded polarizing plate, and its processing steps are shown in Figure 4, including: Step a. Stripping operation: peel off the PET protective film on the surface of a polarizing plate to make it Separate from the polarizer to form a PET protective film and a bare polarizer; step b. pulverization: pulverize the bare polarizer to form a powder; step c. dissolving, pressurizing and stirring: The steam dissolves the adhesive and iodide ions in the powder, and pressurizes and stirs the powder to form a mixture; step d. Condensation operation: condense potassium iodide with a purity >99% from the mixture for recycling, and the mixture forms Non-iodine recyclate; step e. Sieving operation: separate PET material and non-PET material from the non-iodine recyclate; Step f. Press filtration operation: process the non-PET material separated by step e. Solid fuel (SRF); step g. liquid-phase thickened recycled polyester operation: the PET material separated in step e. and the PET protective film layer peeled off in step a. are made into PET plastic pellets; and the aforementioned steps a. to step c. belong to the deiodination purification process, the purpose of which is to peel off the PET protective film layer attached to the surface of the discarded polarizer, and to peel off the polarizer bare plate after the PET protective film layer is removed. The contained iodide ions are dissolved; moreover, the aforementioned steps d. to step g. belong to the sorting and recycling process, and its purpose is to sort and recycle the structures of the discarded polarizing plates to obtain potassium iodide, solid fuel (SRF) and PET plastic pellets, so that resources can be reused.

The operation method of step a. of the present invention is shown in Figure 5, which is to peel off the PET protective film layer 920 on the surface of the discarded polarizer 900 manually or using mechanical equipment, so that the discarded polarizer 900 can be formed into a The bare polarizer plate 910 and a PET protective film layer 920, and the bare polarizer plate 910 includes a release film layer 911, a PSA pressure-sensitive adhesive layer 912, an upper TAC film layer 913, a PVA film layer 914, a lower TAC film The structure of 5 layers such as layer 915; Fig. 6 shows the operation method of its step b. among the present invention, and it uses a grinding machine 10 to carry out the crushing operation of the polarizer bare plate 910, so that the release film layer 911 is included , PSA pressure-sensitive adhesive layer 912, upper TAC film layer 913, PVA film layer 914, and lower TAC film layer 915 to form powder 930; FIG. 7 shows the operation method of step c. in the present invention , which uses a boiler 20 to generate steam 931, and uses a screw extruder 30 to pressurize and stir the powder 930 to form a mixture 940, and simultaneously sends steam 931 into the mixture 940, so that the PSA The adhesive contained in the pressure-sensitive adhesive layer 912 and the iodide ions contained in the PVA film layer 914 are dissolved.

Continuing, Fig. 8 shows the operation method of its step d. and step e. in the present invention, which uses a first conduit 31 and a second conduit 32, respectively installed in the screw extruder 30 and a condensing Between the filter 40, and between the screw extruder 30 and a centrifugal separator 50, the iodine gas 941 and water vapor in the mixture 940 pass through the first conduit from the diffusion port of the screw extruder 30 31 into the condensation filter 40, the iodine gas 941 is condensed out of potassium iodide 950 with a purity >= 99%; and the liquid mixture belonging to the non-iodine recyclate 942 includes PVA (polyvinyl alcohol), TAC (triacetate fiber) and Structural substances such as PET (polyethylene terephthalic acid glycol) are successively screened into non-PET substances 960 and PET substances 970 according to different specific gravity.

Furthermore, Fig. 9 shows the operation method of its step f. and step g. in the present invention, wherein the non-PET material 960 is made into a solid fuel (SRF) 980 by using a filter press 60; Substance 970 and the PET protective film layer 920 peeled off in the aforementioned step a. are applied together to produce PET plastic particles 990 by applying liquid phase thickening recycled polyester; the liquid phase thickening recycled polyester described in the present invention The operation includes a crusher 71, which breaks the aforementioned PET material 970 and PET protective film layer 920, and then sends them into a kettle-type reaction tank 80 for heating and stirring. Its structure is as shown in Figure 10. The kettle-type The reaction tank 80 includes a tank body 81, a tank cover 82, a jacket 83, an agitator 84, and a transmission device 85. Its heating methods include electric heating, hot water heating, and thermal oil circulation heating. The tank 80 is connected with a control unit 72 and a vacuum unit 73. The control unit 72 can adjust the heating temperature and heating time according to the different characteristics of the PET material 970 and the PET protective film layer 920. The vacuum unit 73 can eliminate the tank 80. If the organic impurities, moisture, and dirt in the body 81 are removed, the molecular chains of the polyester melt will be depolymerized into shorter chains at the final temperature of the kettle type reaction tank 80 at 250 to 300° C., and then polymerized into desired length chains. Molecular chain, and then change the intrinsic viscosity (I.V.), melting point and molecular chain structure of polyester, so as to be suitable for the reuse of recycled polyester (PET); Finally, further apply a granulator 74 to make the recycled polyester (PET) ) made of PET plastic pellets 990 to provide recycled polyester with high utilization and high economic benefits.

Please refer to FIG. 11 and FIG. 12 , wherein FIG. 11 discloses a photo of the solid fuel (SRF) product produced by the recycling process of the present invention, and FIG. 12 discloses a photo of the plastic pellet product produced by the recycling process of the present invention. The photo of the above-opened product shows that the present invention can indeed achieve the expected recycling purpose and benefit.

Therefore, with the help of the technical means disclosed above, the present invention uses the deiodination purification process 810 to peel off the PET protective film layer 920 from the discarded polarizer 900, and dissolve the iodine ions in the PVA film layer 914; and then classify Recycling process 820, condensing iodine gas into potassium iodide 950 with a purity ≥ 99% for further recycling; non-PET material 960 is made into solid fuel (SRF) 980 to provide fuel for high energy efficiency boilers; PET material 970 is the same as the aforementioned The PET protective film layer 920 peeled off first is made into PET plastic pellets 990 to provide recycled polyester with high utilization and high economic benefits; because the present invention can process the waste polarizer 900 to obtain potassium iodide with a purity ≥ 99% 950, solid fuel (SRF) 980 and PET plastic pellets 990, so the present invention has the effects of reducing environmental pollution and resource recycling.

In summary, the technical means disclosed in the present invention are indeed "novelty" and "advancement". "Natural" and "available for industrial use" and other invention patent requirements, I pray to the Jun Bureau to grant patents to encourage inventions without any sense of virtue.

However, the drawings and descriptions disclosed above are only preferred embodiments of the present invention, and modifications or equivalent changes made by those who are familiar with the art according to the spirit of this case should still be included in the scope of the patent application of this case.

10: Grinder 20: Boiler 30: Screw extruder 31: First conduit 32: Second conduit 40: Condensation filter 50: Centrifugal Separator 60: Filter press 71: Crusher 72: Regulatory unit 73: Vacuum unit 74: Granulator 80: Kettle reaction tank 81: tank body 82: slot cover 83:Jacket 84: Stirrer 85: transmission 810: Deiodination purification process 811: Stripping operation 812: Crushing operation 813: Dissolving, pressurizing and stirring operations 820: Sorting recycling process 821: Condensation operation 822: Sieving operation 823: Filtration operation 824: Operation of liquid-phase viscosified recycled polyester 900: waste polarizer 910: bare polarizer 911: release film layer 912: PSA pressure sensitive adhesive layer 913: Upper TAC film layer 914:PVA film layer 915: Lower TAC film layer 920: PET protective film layer 930: powder 931: steam 940: mixture 941: iodine gas 942: Non-iodine recovery 950: Potassium iodide 960: Non-PET substances 970: PET material 980: Solid Fuel (SRF) 990: PET plastic pellets

Figure 1 is a schematic diagram of the structure of a conventional polarizer. Fig. 2 is a structure diagram of the output of the recycling process of the present invention. Fig. 3 is a structure diagram of the recycling process steps of the present invention. Fig. 4 is a block diagram of the recycling process steps of the present invention. Fig. 5 is a schematic diagram of the operation method of step a. of the present invention. Fig. 6 is a schematic diagram of the operation method of step b. of the present invention. Fig. 7 is a schematic diagram of the operation method of step c. of the present invention. Fig. 8 is a schematic diagram of the operation method of step d. and step e. of the present invention. Fig. 9 is a schematic diagram of the operation method of step f. and step g. of the present invention. Fig. 10 is a schematic diagram of the structure of the medium tank reaction tank of the present invention. Fig. 11 is a photo of the solid fuel (SRF) product produced by the recycling process of the present invention. Fig. 12 is a photo of the plastic granules produced by the recycling process of the present invention.

810: Deiodination purification process

811: Stripping operation

812: Crushing operation

813: Dissolving, pressurizing and stirring operations

820: Sorting recycling process

821: Condensation operation

822: Sieving operation

823: Filtration operation

824: Operation of liquid-phase viscosified recycled polyester

900: waste polarizer

910: bare polarizer

911: release film layer

912: PSA pressure sensitive adhesive layer

913: Upper TAC film layer

914:PVA film layer

915: Lower TAC film layer

920: PET protective film layer

930: powder

931: steam

940: mixture

941: iodine gas

942: Non-iodine recovery

950: Potassium iodide

960: Non-PET substances

970: PET material

980: Solid Fuel (SRF)

990: PET plastic pellets

Claims (8)

A method for recycling polarizer structures is to recycle the structures in discarded polarizers for reuse. The processing method includes the following steps: a. Peeling off the PET protective film layer on the surface of a discarded polarizer to make it free from the Separation of waste polarizers to form a PET protective film and a bare polarizer; b. Pulverize the bare polarizer to form a powder; c. Dissolve the adhesive and iodide ions in the powder with steam, and pressurize , stirring the powder to form a mixture; d. using a condensation filter to condense the mixture formed in step c. to condense the purity from the mixture

99% potassium iodide is recovered and reprocessed, and the mixture forms a non-iodine recovery after condensation; e. Use a centrifugal separator to screen the non-iodine recovery of the step d. Formed from the non-iodine recovery Separating out PET substances and non-PET substances; f. making solid fuel (SRF) from the non-PET substances separated by step e. after pressure filtration; g. separating the PET substances and step a. The peeled-off PET protective film is made into PET plastic pellets through a liquid-phase thickening process of recycled polyester. The method for recycling polarizer structures as described in item 1 of the scope of the patent application, wherein, step a. includes peeling off the PET protective film layer on the surface of the waste polarizer by manual or mechanical equipment. The method for recycling polarizer structures as described in item 1 of the scope of the patent application, wherein, the step b. is to use a grinder to crush the bare polarizer. The method for recycling polarizer structures as described in item 1 of the scope of the patent application, wherein the step c. uses a boiler to generate steam, and uses a screw extruder to pressurize and stir the powder to form a mixture. The method for recovering polarizing plate structures as described in item 1 of the scope of the patent application, wherein, the step e. is to use the centrifugal sorter to screen out the non-iodine recovered materials including PVA (polyvinyl alcohol), TAC (three Acetate) and PET (polyethylene terephthalic acid glycol) and other materials with different specific gravity, wherein the PET is the PET material, and the PVA and TAC are the non-PET material. The method for recycling polarizer structures as described in item 5 of the scope of the patent application, which further includes a first conduit and a second conduit, which are respectively arranged between the screw extruder and the condensation filter, and the Between the screw extruder and the centrifugal separator, the iodine gas and water vapor in the mixture enter the condensing filter from the diffusion port of the screw extruder through the first conduit, instead of the iodine recovery. The liquid mixture enters the centrifugal separator through the second conduit from the outlet of the screw extruder. The method for recycling polarizer structures as described in item 1 of the scope of the patent application, wherein, the step f. is to use a filter press to make the non-PET material into the solid fuel (SRF). The method for recycling polarizing plate structures as described in item 1 of the scope of the patent application, wherein, in the step g., the liquid-phase thickened recycled polyester operation is to use a tank-type reaction tank to combine the PET material with the PET The protective film is heated, stirred, and vacuumed to depolymerize the molecular chains of the polyester melt into shorter chains, and then polymerize into molecular chains of appropriate length, thereby changing the intrinsic viscosity (I.V.), melting point and molecular weight of the polyester. The chain structure is suitable for the reuse of recycled polyester (PET); and the recycled polyester (PET) is made into PET plastic pellets by a pelletizer.