TWI822231B - Method for treating a polarizing material and recycled polarizing material treated by the same - Google Patents

Abstract

A method for treating a polarizing material is provided for treating the polarizing material including iodine. The method includes following steps. First, the polarizing material is immersed in an alkaline solution without a crushing treatment conducted previously, such that the iodine reacts with and is dissolved into the alkaline solution, so as to remove the iodine from the polarizing material. Thereafter, the polarizing material is subjected to a dehydration treatment and a cleaning treatment.

Description

Polarizing material processing method and recycled polarizing material processed thereby

The invention relates to a polarizing material processing method and the recycled polarizing material processed by the polarizing material processing method. In particular, the present invention relates to a polarizing material processing method for processing polarizing materials containing iodine and the recycled polarizing material treated thereby.

In common polarizers, the material used to achieve the polarizing effect is polyvinyl alcohol (PVA) as the main body, and usually further includes iodine. Since the material composition is not a single component, whether it is the polarizing material waste in the manufacturing process or the polarizing plate after the display device is discarded, it needs to be processed before it can be recycled and reused rather than simply discarded. However, if polarizing materials containing iodine are used, the iodine will produce purple smoke when burned, so large-scale incineration cannot be used for waste disposal. Although it can also be disposed of by landfill or a small amount of mixed incineration, these two waste treatment methods are easy to cause environmental pollution and cannot achieve proper utilization of waste.

Alternatively, you can also consider removing the iodine through a chemical reaction and then recycling the remaining polyvinyl alcohol material. However, common chemical treatment processes can It can lead to the generation of polyene, which denatures polyvinyl alcohol and causes a decrease in processing efficiency. The generation of polyene is due to the hydroxyl groups in the polyvinyl alcohol structure produced during chemical tests of polarizing materials. Protonic acid (the more water content of the polarizing material, the more protonic acid will be) will cause dehydration, thereby forming a conjugated polyene structure, resulting in a yellowing phenomenon in the appearance of the polarizing material.

Among currently commonly used recycling methods, crushing is generally performed first to crush polarizing materials into small pieces to improve reaction efficiency. However, this complicates handling equipment and may cause flying debris that threatens operator safety.

The object of the present invention is to solve at least part of the above-mentioned problems that may occur in the processing method of polarizing materials containing iodine.

In one aspect of the present invention, a polarizing material processing method is provided for processing polarizing materials containing iodine. The polarizing material processing method includes the following steps. First, the polarizing material that has not been crushed is immersed in an alkali solution, so that the iodine reacts with the alkali solution and is dissolved into the alkali solution, so as to remove the iodine from the polarizing material. Afterwards, the polarizing material after removing the iodine is dehydrated and cleaned.

The polarizing material processing method may also include the following steps. First, the polarizing material that has not been crushed is subjected to a loosening process. Afterwards, the polarizing material is immersed in an alkali solution, so that the iodine reacts with the alkali solution and is dissolved into the alkali solution, so as to remove the iodine from the polarizing material. Finally, the polarizing material after removing the iodine is dehydrated and cleaned.

In another aspect of the invention, a recycled polarizing material is provided. It is processed by the polarizing material processing method of the present invention. Recycled polarizing materials contain virtually no iodine. Recycled polarizing materials do not contain polyene.

In order to have a better understanding of the above and other aspects of the present invention, examples are given below and are described in detail with reference to the accompanying drawings:

10:Polarizing material

10’: Polarized material

12:Scroll

20:lye

20’:lye

22:Container

102: Unwinding roller

104: Swelling tank

106:Dyeing tank

108: Cross-linking tank

110: Washing tank

112: Drying oven

114: Winding roller

120: Guide roller

200: Polarizing material precursor

200’:Polarizing material

R: Reel radius

S0: step

S1: Steps

S2: Step

T: Thickness of coil

W: Width

Figure 1 illustrates an exemplary polarizing material manufacturing process.

Figure 2 illustrates the flow of an exemplary polarizing material processing method.

Figures 3-6 illustrate details of exemplary polarizing material processing methods.

Figure 7 illustrates the flow of another exemplary polarizing material processing method.

The details of the present invention will be described below with reference to the accompanying drawings. The following content and accompanying drawings are for illustrative purposes only and are not intended to be limiting. For purposes of clarity, elements in the drawings may not be drawn to actual scale. Additionally, some elements and/or symbols may be omitted in some drawings. It is contemplated that elements and features of one embodiment can be advantageously incorporated into another embodiment without further elaboration.

One aspect of the present invention relates to a polarizing material processing method for processing polarizing materials containing iodine. It should be understood that the "iodine" mentioned in the present invention does not simply refer to the I ₂ molecule, but includes iodine present in the polarizing material in various possible forms such as molecules, ions, or compounds. According to some embodiments, common polarizing materials may be used, including extended bridged polyvinyl alcohol (PVA). Such materials can be made using general polarizing material manufacturing processes and do not need to be particularly limited. For example, please refer to Figure 1, which illustrates an exemplary polarizing material manufacturing process.

Figure 1 shows a system for manufacturing polarizing materials, including an unwinding roller 102, a swelling tank 104, a dyeing tank 106, a cross-linking tank 108, a washing tank 110, a drying oven 112, and a winding roller 114. After the polarizing material precursor 200 is unrolled from the unwinding roller 102, it is guided and transported by the guide roller 120 and passes through each processing tank and processing equipment in the direction indicated by the arrow. The formed polarizing material 200' is then re-wound on the winding roller 114 to facilitate transportation.

The polarizing material precursor 200 is, for example, a polyvinyl alcohol film. The polyvinyl alcohol used can be formed by saponifying polyvinyl acetate. According to some embodiments, polyvinyl acetate can be a monopolymer of vinyl acetate, or a copolymer of vinyl acetate and other monomers. The other monomers can be unsaturated carboxylic acids, olefins, and unsaturated sulfonic acids. , or vinyl ethers, etc. In some embodiments, polyvinyl alcohol can be modified, such as aldehyde-modified polyvinyl formal (polyvinylformal), polyvinyl acetic acid, or polyvinyl butyral (polyvinylbutyral), etc. It will be appreciated that other suitable materials other than polyvinyl alcohol may be used. In some embodiments, the thickness of the polarizing material precursor 200 is about 20 μm to 100 μm.

The polarizing material precursor 200 may first be guided to the swelling tank 104 by the guide roller 120 to perform swelling treatment on the polarizing material precursor 200 . The swelling treatment can remove foreign matter on the surface of the polarizing material precursor 200 and the plasticizer in the polarizing material precursor 200, and facilitates subsequent dyeing and cross-linking processes.

According to some embodiments, the polarizing material precursor 200 may be extended in a system for manufacturing polarizing materials. The stretching treatment can be performed while passing through the swelling tank 104 and/or the subsequent dyeing tank 106 and cross-linking tank 108 . For example, the guide roller 120 provided at the entrance of the expansion tank 104 and the guide roller 120 provided at the exit of the expansion tank 104 may have a peripheral speed difference to perform the uniaxial stretching process. According to some embodiments, from the swelling treatment to the cross-linking treatment, the cumulative extension ratio of the polarizing material precursor 200 is about 4.5 times to 8 times.

The polarizing material precursor 200 is then guided to the dyeing tank 106 by the guide roller 120 to perform dyeing treatment on the polarizing material precursor 200 . The bath liquid in the dyeing tank 106 contains a dye. Dichroic pigments or other suitable water-soluble dichroic dyes can be used as the dyeing agent. In some embodiments, the stain includes iodine and potassium iodide. For example, the dye may be an aqueous solution containing 0.003 to 0.2 parts by weight of iodine and 3 to 30 parts by weight of potassium iodide. In some embodiments, the temperature of the dyeing treatment is 10°C to 50°C, and the time of the dyeing treatment is 10 seconds to 600 seconds. In order to make the dyeing treatment more effective, other additives can be included in the bath, such as boric acid.

The polarizing material precursor 200 is then guided to the cross-linking groove 108 by the guide roller 120 to perform cross-linking treatment on the polarizing material precursor 200 . The bath liquid in the cross-linking tank 108 contains a cross-linking agent, for example, boric acid can be used. The bath liquid in the cross-linking tank 108 may further include an optical adjustment agent, such as an iodine-based optical adjustment agent. For example, the optical modifier can be potassium iodide, zinc iodide, or a combination thereof. Changing the concentration of the optical modifier can adjust the hue of the polarizing material. In some embodiments, to adjust the optical tuning The reducing agent can also be selectively added to the cross-linking tank 108 according to the concentration of the whole agent. The reducing agent may be thiosulfate, disulfinate, sulfite, sulfurous acid, nitrite, iron salt, or tin salt. In some embodiments, the bath liquid of the cross-linking tank 108 is an aqueous solution, which contains 1 to 10 parts by weight of boric acid and 1 to 30 parts by weight of potassium iodide. In some embodiments, the temperature of the cross-linking treatment is 10°C to 70°C, and the time of the cross-linking treatment is 1 second to 600 seconds. According to some embodiments, the cross-linking treatment needs to be performed in an acidic environment, with a pH value of, for example, 2 to 5. Therefore, the bath liquid of the cross-linking tank 108 may further include a pH adjusting agent. The pH adjuster is, for example, perchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, formic acid, ascorbic acid, or acetic acid. According to some embodiments, additional precipitating agent can be added to the bath liquid to adjust the bath liquid. The precipitating agent includes, for example, a compound of anions and metal cations, wherein the metal cations react with the anions of the pH adjuster in the bath to form a precipitated compound.

After the cross-linking process, the polarizing material precursor 200 can be guided by the guide roller 120 to the cleaning tank 110 , where solvents and/or impurities that may remain in the polarizing material precursor 200 due to previous processes are removed.

The polarizing material precursor 200 is then guided to the drying furnace 112 by the guide roller 120 to dry the polarizing material precursor 200 . After the drying process, it is the polarizing material 200'.

Please refer now to Figure 2, which illustrates the flow of an exemplary polarizing material processing method of the present invention.

As shown in step S1, in the polarizing material processing method of the present invention, the polarizing material that has not been broken is immersed in the alkali solution, so that the iodine reacts with the alkali solution and is dissolved into the alkali solution, so as to remove the iodine from the polarizing material. remove.

As shown in Figure 3, the polarizing material 10 that has not been crushed can be in the form of a roll. For example, it may be a material that was made using the system in Figure 1 but became scrap, but is not limited to this. The polarizing material 10 may be wound on a reel 12 . The reel 12 can be a solid or hollow object capable of supporting the rolled material, and its material does not need to be particularly limited as long as it does not affect the reaction in step S1. Here, the radius of the reel 12 is defined as the reel radius R of the reel, and the thickness of the polarizing material 10 on the reel 12 is defined as the reel thickness T of the reel. The reel radius R is, for example, 9 cm. The roll thickness T is, for example, 1 cm to 22.5 cm. If the roll material is made into scrap using the system in Figure 1, the width W is, for example, 1000mm to 2500mm. However, these numerical values are for example only and are not limited thereto. It can be understood that the fact that the polarizing material 10 has not undergone a crushing process only means that it has not been completely broken into fragments as recognized by ordinary people. It does not mean that it cannot undergo preliminary processing such as cutting to reduce its size. The polarizing material 10 that has not been crushed may not be in the form of a roll material, but may be in the form of a substantially complete film material or the like.

2.5R。如果捲軸半徑R與捲材厚度T的比例超過1：2.5，因為捲材過厚，可能無法完整破裂，進而導致某些部分偏光材料10無法接觸鹼液20而成功去除碘。根據一些實施例，可以令捲材的捲軸半徑R與捲材厚度T的比例在1：0.1以上。如果捲材太薄，則單次處理量太小，經濟效益不佳。 As shown in FIG. 4 , in step S1 , the polarizing material 10 may be in the form of a roll and immersed in the alkali solution 20 . Alkaline solution 20 may be contained in container 22 . The container 22 can be a barrel, a tank, etc., and is not particularly limited as long as it does not affect the reaction of step S1. Since the reel 12 provides tension to the web, the polarizing material 10 will rupture and unfold in a specific direction such as the web thickness T due to the extensibility and tension after being immersed in the alkali solution 20. This is because the polarizing material 10 will change after adding the alkali solution 20. The bridging structure (as shown in Figure 5) causes the polarizing material 10 to become loose and cause cracks. Even if it is not broken, the alkali solution 20 can penetrate into these cracked spaces and complete the reaction with the polarizing material 10 as a whole. Therefore, as long as the entire polarizing material 10 is immersed in the alkali solution 20, the operation steps can be completed and the processing efficiency can be improved. Although the width W of the rolled material to be processed is not limited as long as the container 22 can accommodate it, in some embodiments, in order to speed up the processing, the rolled material can be cut first to reduce its width W to 100 mm to 2500 mm. In some embodiments, the ratio of the reel radius R of the coil immersed in the alkali solution 20 to the thickness T of the coil is less than or equal to 1:2.5, that is, T

2.5R. If the ratio of the reel radius R to the roll thickness T exceeds 1:2.5, the roll may not be completely broken because the roll is too thick, which may result in some parts of the polarizing material 10 not being able to contact the alkali solution 20 to successfully remove iodine. According to some embodiments, the ratio of the reel radius R of the coil to the thickness T of the coil can be made above 1:0.1. If the roll is too thin, the single processing volume will be too small and the economic benefits will be poor.

According to some embodiments, the alkali solution 20 may be an aqueous calcium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous barium hydroxide solution, an aqueous sodium hydroxide solution, an aqueous sodium bicarbonate solution, or other suitable alkaline aqueous solutions. The aqueous solution can be used simply without additional mixing with other solvents such as propanol. According to some embodiments, the concentration of the alkali solution 20 may be 0.1% to 30%, especially 5% to 10%. Too high a concentration of lye 20 may lead to the production of polyenes. According to some embodiments, the solid-liquid weight ratio of the polarizing material 10 and the alkali solution 20 may be 1:1 to 1:100, especially 1:20 to 1:50. If the solid-to-liquid weight ratio is too low, the amount of alkali solution is insufficient to react with the entire polarizing material, and the iodine will not be effectively dissolved to remove the iodine from the polarizing material. However, if the solid-to-liquid weight ratio is too high, the water-soluble polarizing material will be damaged due to the high water content. The material is dissolved in large quantities, resulting in the iodine dissolved in the alkali solution still not being effectively removed from the polarizing material. It should be understood that as long as the reaction in step S1 is not affected, the materials and parameters used can be adjusted and are not limited thereto.

According to some embodiments, in step S1, the temperature of the alkali solution may be 0°C to 70°C, especially 10°C to 65°C. If the temperature of the lye exceeds 70°C, polyene production may occur.

The reaction mechanism between the polarizing material 10 and the alkali solution 20 includes the following formula 1.

請同時參照第5圖，原本I₂可能以

或

等形式存在於偏光材料10，經過與鹼液20的OH^-的反應之後，形成可以溶於水溶液的

和I^-離子，進而能夠令碘離開偏光材料10。

Please also refer to Figure 5. Originally I ₂ might be

or

etc. exist in the polarizing material 10. After reacting with the ^OH- of the alkali solution 20, they form soluble in the aqueous solution.

and I ^- ions, thereby enabling iodine to leave the polarizing material 10 .

Figure 6 shows the polarizing material 10' after the reaction. The iodine has been dissolved in the aqueous solution to form an alkali solution 20' containing iodine. As shown in Figure 6, although the polarizing material 10 breaks and unfolds in a specific direction, the overall shape of the roll is still maintained after the reaction, making it easy to take out, thereby improving processing efficiency.

Please return to Figure 2 again. In step S2, the polarizing material after removing iodine is dehydrated and cleaned. Thereby, the alkali solution 20' and/or impurities remaining on the polarizing material 10 can be removed, and the processed polarizing material 10' can be obtained. According to some embodiments, the processed iodine content of the polarizing material 10' is less than 100 ppm. That is, after going through steps S1 and S2, the polarizing material 10' is substantially free of iodine. In this embodiment, the polarizing material 10' after recycling is substantially free of iodine, and It can still maintain the shape of the roll. Compared with the traditional technology of crushing and then recycling, the polarizing material 10' in this case can be used again without additional processes.

The alkali solution 20' can still be used again. In some embodiments, steps S1 and S2 can be repeated more than 20 times, or even more than 100 times, without changing the alkali solution. That is, the polarizing material treatment method of the present invention can be repeated more than 20 times without replacing the alkali solution.

According to some embodiments, iodine can be further recovered from the alkali solution 20'. For example, electrodialysis may be used to recover iodine from the alkali solution 20', but is not limited thereto. The recovered iodine can also be reused.

Figure 7 illustrates the flow of another exemplary polarizing material processing method of the present invention. The difference from the flow of the polarizing material processing method in Figure 2 is that there is an additional pre-processing step S0.

In step S0, a pre-processing step of loosening is performed on the polarizing material that has not been broken, so that the structure of the polarizing material is initially loosened. This will facilitate the subsequent reaction with the alkali solution and allow the alkali solution to penetrate into the membrane more easily. The loosening treatment includes, for example, immersing the polarizing material in a swelling agent. According to some embodiments, the swelling agent may be water, a hydrophilic liquid, or a liquid containing -H or -OH groups. Hydrophilic liquids are, for example, polar solvents. According to some embodiments, the temperature of the loosening process may be 5°C to 50°C. In some embodiments, after the loosening process, the solvent content rate of the polarizing material is equal to or greater than 30%. The solvent content rate reflects the initial loosening degree of the polarizing material, and its calculation method is as shown in Equation 2.

Steps S1 and S2 can then be continued. Here, for the sake of convenience, steps S1 and S2 may be collectively referred to as iodine extraction treatment. The same details will not be repeated again.

Another aspect of the present invention relates to a kind of recycled polarizing material, which is processed by the polarizing material processing method as described in any of the above embodiments. Therefore, recycled polarizing materials contain virtually no iodine. Moreover, the recycled polarizing material may not contain polyene. In some embodiments, the recycled polarizing material may include extended bridged polyvinyl alcohol (PVA). In some embodiments, the recycled polarizing material is in roll form.

Here, in order to assist in a clearer understanding of the present invention, more specific examples and comparative examples and their processing results are also provided. The embodiments and comparative examples were processed using the flow of the polarizing material processing method described above. Examples 1 to 14 and Comparative Examples 1 to 10 correspond to the flow shown in Figure 2 . Specific materials and parameters are listed in Table 1. The processing results are listed in Table 2.

*R: T is the ratio of reel radius to coil thickness

Examples 1 to 14 all use alkali liquid as a solvent. The concentration of the solvent is in the range of 0.1% to 30%. The solid-liquid weight ratio of the polarizing material and the solvent is in the range of 1:1 to 1:100. The alkali liquid is The temperature is in the range of 10℃ to 65℃, and the ratio of reel radius to coil thickness is less than or equal to 1:2.5. The results show that the iodine content in the solid is less than 100 ppm, that is, the polyvinyl alcohol after treatment is substantially free of iodine. Among them, the solid-liquid weight ratio of Example 13 and Example 14 was further reduced to the range of 1:20 to 1:50, and the iodine content in the treated solid was further reduced. In addition, according to the results of determining the presence of polyene signals (at two locations: 1100 cm ⁻¹ and 1500 cm ⁻¹ ) using a Raman spectrometer, no polyene was produced in Examples 1 to 14. A polyvinyl alcohol bridging degree of 0 means that the polarizing material is indeed broken and unfolded, which is conducive to the penetration of the solvent into the created space and then completes the overall reaction with the polarizing material.

Comparative Example 1 also used an alkali solution as a solvent, but the concentration of the alkali solution was too high, resulting in the production of polyene. The temperature of the alkali solution in Comparative Example 2 is too high, which also leads to the production of polyene. The solid-to-liquid weight ratio in Comparative Example 3 is too low, which means that the amount of alkali solution is not enough to react with the entire polarizing material, so that polyvinyl alcohol and iodine cannot be effectively separated. Scroll of Comparative Example 4 The ratio between the radius and the thickness of the roll is too high, which makes it difficult for the alkali solution to react with the part of the polarizing material close to the roll, and cannot effectively separate polyvinyl alcohol and iodine. The solvents in Comparative Examples 5 to 7 are not alkaline solutions and cannot react with polarizing materials. Although alkali solution was also used as the solvent in Comparative Example 8, the concentration of the alkali solution was too low, resulting in the inability to react effectively, and therefore the polyvinyl alcohol and iodine could not be effectively separated. In Comparative Example 9, the temperature of the alkali solution was also too high, resulting in the production of polyene. The solid-to-liquid weight ratio of Comparative Example 10 is too high, and due to the high water content, a large amount of water-soluble polyvinyl alcohol is dissolved in the alkali solution, which leads to the inability to effectively separate polyvinyl alcohol and iodine.

Examples 15 to 21 and Comparative Examples 11 to 13 correspond to the flow shown in Figure 7. The specific materials and parameters of the loosening treatment step are listed in Table 3, in which sulfuric acid is a liquid containing -H groups, methyl ethyl ketone and ethyl acetate are hydrophilic polar solvents, potassium hydroxide is a liquid containing -OH groups, and polyethylene hydroxide is a liquid containing -OH groups. Alkenes are non-hydrophilic solvents. The sample width of polarizing material is 300mm, and the ratio of reel radius to roll thickness is 1:0.1. Then potassium hydroxide with a concentration of 10% was used as the solvent, the solid-liquid weight ratio was set at 1:10, and the temperature was set at 50°C to dissolve the iodine. After immersing in alkaline solution for 4 hours, take out the polarizing material sample, use Equation 3 to calculate the iodine extraction rate of the 4-hour treatment, and observe the filtration difficulty of filtered iodine to confirm the help of pretreatment in iodine extraction. The processing results are listed in Table 4.

Comparing the results of Examples 15 to 21 and Comparative Examples 11 to 13, it can be seen that when a swelling agent is used for pretreatment to increase the solvent content rate of the polarizing material to more than 30%, it is obviously beneficial to the subsequent iodine extraction treatment.

To sum up, the present invention can effectively carry out chemical reactions without crushing polarizing materials, and can remove iodine from polarizing materials in a simple and safe manner, thereby facilitating the recycling and reuse of host materials such as polyvinyl alcohol. Moreover, the solvent used can be reused, which is environmentally friendly and can further simplify processing operations. Recycle The rolled polarizing material can then be used for other purposes compared to traditional pulverization, achieving the goal that all products and solvents can be completely recycled.

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can make various modifications and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the appended patent application scope.

S1: Steps

S2: Step

Claims (10)

A polarizing material processing method for processing polarizing materials containing iodine. The polarizing material processing method includes: immersing the polarizing material that has not been broken into an alkali solution, so that the iodine reacts with the alkali solution and Dissolve into the alkali solution to remove the iodine from the polarizing material, wherein the solid-liquid weight ratio of the polarizing material to the alkali solution is 1:1 to 1:100, wherein the polarizing material The method is to immerse in the alkali solution in the form of a roll, and the ratio of the roll radius of the roll to the thickness of the roll is less than or equal to 1:2.5; and the polarizing material after removing the iodine is dehydrated and Cleaning process. The polarizing material processing method as claimed in claim 1, wherein the polarizing material further includes extended bridged polyvinyl alcohol (PVA). The polarizing material processing method according to claim 1, wherein the alkali solution is calcium hydroxide aqueous solution, potassium hydroxide aqueous solution, barium hydroxide aqueous solution, sodium hydroxide aqueous solution, or sodium bicarbonate aqueous solution; and/or wherein The concentration of the alkali solution is 0.1% to 30%; and/or the temperature of the alkali solution is 0°C to 70°C. The polarizing material processing method as described in claim 1, wherein the iodine content of the polarizing material after treatment is less than 100 ppm. A polarizing material processing method for processing polarizing materials containing iodine, the polarizing material processing method includes: loosening the polarizing material that has not been broken; immersing the polarizing material in an alkali solution, so that The iodine reacts with the alkali solution and is dissolved into the alkali solution to remove the iodine from the polarizing material, wherein the The solid-liquid weight ratio of the polarizing material to the alkali solution is 1:1 to 1:100, wherein the polarizing material is immersed in the alkali solution in the form of a roll, and the reel radius of the roll is equal to the thickness of the roll. The ratio is less than or equal to 1:2.5; and dehydrating and cleaning the polarizing material after removing the iodine. The polarizing material processing method according to claim 5, wherein the loosening treatment is to immerse the polarizing material in a swelling agent, wherein the swelling agent is water, a hydrophilic liquid, or contains -H or -OH groups of liquid. The polarizing material processing method according to claim 5, wherein the temperature of the loosening treatment is 5°C to 50°C. The polarizing material processing method according to claim 5, wherein after the loosening process, the solvent content rate of the polarizing material is equal to or greater than 30%. A recycled polarizing material is processed through the polarizing material processing method described in any one of claims 1 to 8, the recycled polarizing material does not contain substantially iodine, and the recycled polarizing material does not contain polyene. The recycled polarizing material as described in claim 9, wherein the recycled polarizing material is in the form of a roll.

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