A method for preparing poly (4-hydroxystyrene) polymer
Through non-metallic catalysts and high-temperature treatment, combined with acid or alkali solution deprotection and solvent water cleaning, the colorimetric and metal impurities of poly(4-hydroxystyrene) polymers are solved, and high light transmittance and high light transmittance are achieved Finished photoresist with sensitivity.
Patent Information
- Application Number
- CN202411339725.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2044-09-25
AI Technical Summary
It is difficult to prepare poly(4-hydroxystyrene)-based polymers with low chromaticity and high light transmittance in the prior art, and there are problems of metal impurities residues and darker chromaticity.
Non-metallic catalysts are used to carry out stage heating reactions, and the catalyst is annihilated by high temperature. Then, the acid or alkali solution is used for deprotection treatment, combined with repeated cleaning of solvent and water and vacuum drying, to obtain poly(4) with a color of less than 30. -hydroxystyrene) polymers.
The residual amount of metal impurities is effectively controlled, the color of the polymer is reduced, the sensitivity of the photoresist is improved, the exposure time is shortened, the production capacity is improved, and the sensitivity of the photoresist products is significantly improved.
Smart Images
Figure SMS_4 
Figure FDA0005140990910000011
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of high molecular polymers, and in particular relates to a method for preparing a poly (4-hydroxystyrene) polymer. Background Art
[0002] Photoresist refers to a corrosion-resistant thin film material whose solubility changes through irradiation and radiation of ultraviolet light, electron beam, particle beam, X-ray, etc. It is generally composed of film-forming resin, photoinitiator, solvent, monomer, etc. Among them, film-forming resin is the most important component of photoresist, which determines the basic properties of photoresist such as adhesion, chemical corrosion resistance, and film thickness. Poly(4-hydroxystyrene) polymers can be used for photolithography in a shorter wavelength range due to their low deep ultraviolet light absorption rate; and they have high sensitivity and high resolution, which can prepare more delicate patterns. It has become a special film-forming resin for 248nm deep ultraviolet photoresist. The chromaticity of the film-forming resin has a great influence on the sensitivity of the photoresist product. The darker the resin color, the worse the sensitivity of the photoresist, and it is inevitable to increase the exposure energy or extend the exposure time, thereby affecting production efficiency and production capacity.
[0003] US invention patent US4028340A discloses a method for preparing p-vinylphenol polymers, using 4-hydroxystyrene as a starting monomer and using free radical polymerization to prepare poly (4-hydroxystyrene). The monomers used in this process are prone to self-polymerization at room temperature, and the product obtained by free radical polymerization has a low conversion rate and a wide molecular weight distribution. The residual monomers need to be processed, and the product contains quinone ketone colored byproducts and exhibits a reddish brown color, which cannot meet the performance requirements of deep ultraviolet light.
[0004] Japanese invention patent JP2002241429A discloses a method for preparing poly(p-vinylphenol), using 4-tert-butoxystyrene as a basic monomer and sec-butyl lithium as an initiator, polymerizing to obtain a poly(4-tert-butoxystyrene) solid, and then using an acid for deprotection treatment to obtain a poly(4-hydroxystyrene) solid. Compared with the direct polymerization process, the synthesis process has a greatly improved conversion rate and a narrower molecular weight distribution, but due to the use of a metal catalyst in the synthesis process, it is inevitable that there is a large amount of residual metal, and the product color is light reddish brown, which affects the use.
[0005] Chinese invention patent CN105924553A discloses a method for preparing a polyhydroxystyrene polymer with a narrow molecular weight distribution, wherein acetoxystyrene monomer is polymerized by ATRP active radical polymerization to synthesize a polyacetoxystyrene polymer with a narrow molecular weight distribution; then, an esterification reaction occurs under the catalysis of dilute hydrochloric acid to remove the acetoxy protecting group to obtain a poly(p-hydroxystyrene) polymer, and then ethylenediaminetetraacetic acid is used to remove metal impurities in the resin. However, in the ATRP active radical polymerization process, this method uses an organic bromide as an initiator and a copper salt halide as a catalyst, which easily causes product coloring. The product often appears in reddish brown, which affects the product sensitivity.
[0006] Therefore, how to prepare poly(4-hydroxystyrene) polymers with low chroma and high transmittance is still a problem that needs to be solved urgently and is of great significance. Summary of the invention
[0007] In order to solve the above technical problems, the present invention provides a method for preparing a poly(4-hydroxystyrene) polymer, wherein a polymer containing a protecting group is synthesized by using a non-metallic catalyst and annihilating the non-metallic catalyst through a high temperature stage; an acid solution or an alkaline solution is then used for deprotection treatment to obtain a crude poly(4-hydroxystyrene) polymer; the crude product is repeatedly washed with a certain proportion of solvent and water under stirring conditions, precipitated and vacuum dried under certain conditions to obtain a white solid of the poly(4-hydroxystyrene) polymer; after the white solid is prepared into a solution of a certain proportion in a solvent, a finished solution with a chromaticity (Hazen) lower than 30 can be obtained.
[0008] The object of the present invention is to provide a method for preparing a poly(4-hydroxystyrene) polymer, comprising the following steps:
[0009] S1. Under a protective atmosphere, a monomer of formula I and a non-metallic catalyst are subjected to staged heating reaction in solvent A, and after cooling, they are added to 2-10 times the mass of solvent B for precipitation, and the obtained precipitate is vacuum dried to obtain a polymer of formula II; the staged heating reaction includes two stages, the first stage is a polymerization reaction at 70°C-90°C for 5h-15h, and heat preservation for 30min-60min; the second stage is a polymerization reaction at 100°C-140°C for 1h-3h; the residual non-metallic catalyst is annihilated by the second stage to minimize the influence of the residual non-metallic catalyst on the polymer in the subsequent process; the non-metallic catalyst is selected from one or more of azobisisoheptanenitrile (ABVN), azobisisobutyronitrile (AIBN), azobisisovaleronitrile, dimethyl azobisisobutyrate (AIBME) and dibenzoyl peroxide (BPO);
[0010] S2, under a protective atmosphere, the polymer of formula II is subjected to a deprotection reaction in solvent C under the action of an acid solution or an alkaline solution, and after cooling, is added to 9-13 times the mass of solvent D for precipitation to obtain a crude product of a poly(4-hydroxystyrene) polymer of formula III;
[0011] S3, a crude product of a poly(4-hydroxystyrene) polymer of formula III is added to a solvent E, water is added under stirring and the stirring is continued for 20-60 minutes, the product is allowed to stand until stratification, the lower liquid solution is removed, washing is repeated 3-7 times, the upper solution obtained is added to a solvent F of 2-6 times the mass to precipitate, and the obtained precipitate is vacuum dried to obtain a fine product of a poly(4-hydroxystyrene) polymer of formula III; the solvent E is selected from one or more of propylene glycol methyl ether acetate (PGMEA), n-butanol, ethyl acetate and n-butyl acetate; the mass ratio of the solvent E to water is (70-85): (15-30); if the proportion of the solvent E is too high, the purpose of cleaning and decolorization cannot be achieved; if the proportion of water is too high, the resin will precipitate, affecting the yield;
[0012] Wherein, formula I-formula III are as follows:
[0013] , , ;
[0014] wherein R is selected from -CH3, -C(CH3)3 or -COCH3;
[0015] n is an integer from 20 to 85;
[0016] p+q is 20-85, and p / (p+q) does not exceed 40%.
[0017] In one embodiment of the present invention, in S1, the solvent A is selected from one or more of tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexane, benzene and toluene; the solvent B is selected from one or more of water, n-hexane, methanol, isopropanol and n-heptane.
[0018] In one embodiment of the present invention, in S1, the mass ratio of the monomer of formula I, the non-metallic catalyst and the solvent A is (20-55): (0.1-3): (45-80).
[0019] In one embodiment of the present invention, in S1, the vacuum drying is carried out at a temperature of 30°C-80°C and for a time of 30 min-200 min.
[0020] Furthermore, in S1, the vacuum drying is carried out at a temperature of 50°C-65°C and for a time of 60min-120min.
[0021] In one embodiment of the present invention, in S2, the solvent C is selected from one or more of tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexane, methanol and ethyl acetate; the solvent D is selected from one or more of water, n-hexane, isopropanol and n-heptane.
[0022] In one embodiment of the present invention, in S2, the mass ratio of the polymer of formula II structure, the acid solution or the alkaline solution, and the solvent C is (9-20): (0.5-20): (80-91); the acid solution is selected from one or more of hydrochloric acid solution, hydrobromic acid solution and toluenesulfonic acid solution, and the mass fraction of the acid solution is 10%-40%, preferably 20%-35%; the alkaline solution is sodium hydroxide solution, and the mass fraction of the alkaline solution is 5%-30%, preferably 10%-25%.
[0023] In one embodiment of the present invention, in S2, the temperature of the deprotection reaction is 40°C-65°C, and the time is 1h-5h.
[0024] In one embodiment of the present invention, in S3, the solvent F is selected from one or more of water, n-hexane, isopropanol and n-heptane.
[0025] In one embodiment of the present invention, in S3, the mass ratio of the crude poly(4-hydroxystyrene) polymer of formula III to the solvent E is (10-30):(70-90).
[0026] In one embodiment of the present invention, in S3, the rotation speed of the stirring condition is 200rpm-800rpm; the temperature of the vacuum drying is 40℃-60℃, and the time is 60min-150min; too low temperature or too short time cannot fully dry, and too high temperature or too long time will cause the resin color to darken.
[0027] The technical solution of the present invention has the following advantages over the prior art:
[0028] The preparation method of the present invention adopts a non-metallic catalyst to synthesize a polymer containing a protective group, and can effectively control the residual amount of metal impurities without special treatment, and avoids the chromaticity darkening caused by oxidation of the metal catalyst in subsequent reaction drying and other processes, and annihilates the catalyst at high temperature, accurately controls the molecular weight and distribution of the polymer, and reduces the influence of the residual non-metallic catalyst on the molecular weight in subsequent steps; then, an acid solution or an alkaline solution is used to carry out a deprotection reaction to obtain a crude poly (4-hydroxystyrene) polymer, and the crude product is repeatedly washed with a certain proportion of solvent and water under stirring conditions, and vacuum dried under certain conditions, which can reduce the chromaticity of the polymer to the maximum extent, thereby ensuring the light transmittance of the finished solution, improving the photosensitivity of the photoresist, shortening the exposure time, and improving the production capacity, and at the same time, can further reduce the content of metal impurities.
[0029] The poly(4-hydroxystyrene) polymer prepared by the preparation method of the present invention is applied to semiconductor photoresist film-forming resin, which can significantly improve the sensitivity of the photoresist product, shorten the exposure time and increase the production capacity. DETAILED DESCRIPTION
[0030] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.
[0031] In the present invention, unless otherwise explained, technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs.
[0032] In the present invention, unless otherwise stated, the term "and / or" used in the present invention includes any and all combinations of one or more of the associated listed items.
[0033] In the present invention, unless otherwise stated, the experimental methods used in the embodiments of the present invention are conventional methods unless otherwise stated, and the materials, reagents, etc. used are all commercially available unless otherwise stated. Example 1
[0034] The preparation method of the poly(4-hydroxystyrene) polymer of the present embodiment specifically comprises the following steps:
[0035] S1. Preparation of poly(4-tert-butoxystyrene): 74.2 mL of propylene glycol methyl ether acetate solvent was added to a 500 mL four-necked flask with mechanical stirring, and the temperature was raised to 80° C. under the protection of high-purity nitrogen at a flow rate of 150 mL / min, and a dropwise solution of 111.3 mL of propylene glycol methyl ether acetate solvent, 1.022 mol of monomer 4-tert-butoxystyrene and 0.015 mol of non-metallic catalyst dimethyl azobisisobutyrate was added dropwise, and the addition was completed within 60 min. The mixture was polymerized at 80° C. for 7.5 h and kept warm for 0.5 h, then heated to 120° C. and polymerized for 3 h, cooled to room temperature, and slowly added to 1300 mL of methanol solvent to obtain a precipitate, which was filtered and dried in a vacuum drying oven at 55° C. for 100 min to obtain poly(4-tert-butoxystyrene);
[0036] S2. Preparation of crude poly(4-hydroxystyrene): 32.5 g poly(4-tert-butoxystyrene) and 330 mL tetrahydrofuran solvent were added to a 500 mL four-necked flask with mechanical stirring, stirred at room temperature until dissolved, 26.5 mL of 30% hydrochloric acid solution was added in batches within 10 min, and the temperature was raised to 45° C. and deprotected for 1 h under the protection of high-purity nitrogen at a flow rate of 100 mL / min. After cooling to room temperature, the mixture was slowly added to 3500 mL deionized water solvent to obtain a precipitate, which was filtered to obtain a crude poly(4-hydroxystyrene);
[0037] S3. Preparation of poly(4-hydroxystyrene) fine product: In a 500mL container with mechanical stirring and bottom discharge, add 50g of poly(4-hydroxystyrene) crude product and 200mL of solvent ethyl acetate, stir until completely dissolved, add 60mL of deionized water under stirring condition of 500rpm, stir for 20min, let stand until stratification, drain the lower layer of liquid, repeat (add water-stirring-let stand to stratify-drain liquid) 4 times, slowly add the upper layer solution into 900mL of solvent n-heptane to obtain a precipitate and filter it, dry it in a vacuum drying oven at 55°C for 110min to obtain poly(4-hydroxystyrene) fine product. Example 2
[0038] The method is basically the same as Example 1, except that during the preparation of poly(4-tert-butoxystyrene), the solvent propylene glycol methyl ether acetate is replaced with the solvent propylene glycol monomethyl ether. Example 3
[0039] The method is basically the same as Example 1, except that during the preparation of poly(4-tert-butoxystyrene), the non-metallic catalyst dimethyl azobisisobutyrate is replaced by a non-metallic catalyst azobisisobutyronitrile. Example 4
[0040] The method is basically the same as Example 1, except that in the preparation process of poly(4-tert-butoxystyrene), the monomer 4-tert-butoxystyrene is replaced by the monomer 4-acetoxystyrene; in the preparation process of the crude poly(4-hydroxystyrene), the hydrochloric acid solution with a mass fraction of 30% is replaced by the sodium hydroxide solution with a mass fraction of 25%. Example 5
[0041] The method is basically the same as Example 1, except that in the preparation process of poly(4-tert-butoxystyrene), the monomer 4-tert-butoxystyrene is replaced by the monomer 4-acetoxystyrene; in the preparation process of the crude poly(4-hydroxystyrene), the 30% by mass hydrochloric acid solution is replaced by the 30% by mass sodium hydroxide solution. Example 6
[0042] The method is basically the same as Example 1, except that during the preparation of the crude poly(4-hydroxystyrene), the 30% by mass hydrochloric acid solution is replaced by a 36.5% by mass hydrochloric acid solution. Example 7
[0043] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, the water washing step is repeated 3 times instead of 4 times. Example 8
[0044] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, the water washing step is repeated 7 times instead of 4 times. Comparative Example 1
[0045] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, the water washing step is repeated 2 times instead of 4 times. Comparative Example 2
[0046] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, the water washing step is repeated 8 times instead of 4 times. Comparative Example 3
[0047] The method is basically the same as Example 1, except that in the preparation process of poly(4-tert-butoxystyrene), the monomer 4-tert-butoxystyrene is replaced by the monomer 4-acetoxystyrene; in the preparation process of the crude poly(4-hydroxystyrene), the hydrochloric acid solution with a mass fraction of 30% is replaced by the sodium hydroxide solution with a mass fraction of 35%. Comparative Example 4
[0048] The method is basically the same as Example 1, except that during the preparation of poly(4-tert-butoxystyrene), the temperature is directly lowered to room temperature after being kept at 80° C. for 8 hours. Comparative Example 5
[0049] The method is basically the same as Example 1, except that in the preparation process of poly(4-tert-butoxystyrene), the non-metallic catalyst dimethyl azobisisobutyrate is replaced by the metal catalyst n-butyl lithium, and the reaction is carried out at -60°C for 2 hours and then returned to room temperature. Comparative Example 6
[0050] The process is basically the same as that of Comparative Example 5, except that the operation of S3 is not performed. Comparative Example 7
[0051] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, drying at 55° C. for 110 min is replaced by drying at 80° C. for 200 min. Comparative Example 8
[0052] The method is basically the same as Example 1, except that in the preparation process of the poly(4-hydroxystyrene) product, the amount of deionized water used is replaced by 30 mL instead of 60 mL.
[0053] Test Case
[0054] Based on Examples 1-8 and Comparative Examples 1-8, the molecular weight, conversion rate, chromaticity (Hazen), and metal residue of the prepared polymers were measured:
[0055] (1) Weight average molecular weight Mw and molecular weight distribution PDI: tested by GPC;
[0056] (2) Test and calculation of conversion rate: Weigh the mass a (g) of the iron box on a precision balance, add b (1.00 ± 0.05 g) of the test liquid into the iron box, place it in a 150°C oven for 2 h, take it out of the oven and place it in a drying oven to cool to room temperature, weigh the total mass of the test liquid and the iron box after drying as c (g), and calculate the actual solid content (NV) according to the formula 实 %)=(ca) / b×100%;Divide the theoretical solid content by the actual solid content, and calculate the conversion rate % according to the formula=NV 实 % / NV 理 %×100%;
[0057] (3) Chroma (Hazen): The sample was dissolved in the solvent propylene glycol methyl ether acetate to prepare a solution with a mass fraction of 40%. The solution was tested using a transmission colorimeter.
[0058] (4) Gold impurity content (ppt): tested by ICP-MS;
[0059] Table 1 shows the final measured results:
[0060] Table 1
[0061]
[0062] It can be seen from Table 1 that the polymer prepared in the example has better chroma and lower metal impurity content.
[0063] By comparing Examples 1, 7-8 and Comparative Examples 1-2, it can be seen that the number of cleaning times is too few and the degree of cleaning is not enough to reduce the chromaticity to below 30; when the number of cleaning times is 8 times, the chromaticity is higher than that of Example 1. This is because the excessive number of cleaning times and the long-term contact with the air cause oxidation of the product, so the chromaticity of the product is darker.
[0064] Comparing Examples 1-3, it can be seen that the selection of solvents and non-metallic catalysts has little effect on the color of the product.
[0065] By comparing Examples 1, 4-6 and Comparative Example 3, it can be seen that when a high concentration of acid solution or alkaline solution is used, the product has a high chromaticity. This is mainly because the acid solution or alkaline solution is high, the deprotection reaction is violent, and it is easily affected by oxygen oxidation in a short time, resulting in a high chromaticity of the product.
[0066] By comparing Example 1 and Comparative Example 4, it can be seen that due to the lack of high-temperature annihilation treatment, the non-metallic catalyst remains in the resin, the resin conversion rate is low, and while deprotecting, the residual non-metallic catalyst causes the resin molecular chain to continue to grow. The molecular weight obtained by testing is larger than the designed value, which will cause differences in the performance of the resin when formulated into a photoresist.
[0067] By comparing Example 1 and Comparative Examples 5-6, it can be seen that the metal impurity content of the samples polymerized using metal catalysts is significantly higher than that of the samples polymerized using non-metallic catalysts. After four washes, the metal impurities in Comparative Example 5 are still much higher than those of the samples polymerized using non-metallic catalysts. The metal catalyst is more obviously colored than the non-metallic catalyst, and after washing, the chroma is also significantly higher than that of other examples.
[0068] Comparison of Example 1 and Comparative Example 7 shows that excessively high drying temperature and prolonged drying will aggravate the oxidation reaction of the resin, thereby causing the chromaticity of the resin to deepen.
[0069] By comparing Example 1 and Comparative Example 8, it can be seen that the deionized water amount lower than the set ratio cannot fully play the role of cleaning, so that the resin chromaticity cannot be reduced to less than 30, and a large amount of metal impurities remain.
[0070] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.
Claims
1. A method for preparing a poly(4-hydroxystyrene) polymer, characterized in that: The following steps are involved: S1. Under a protective atmosphere, a monomer of formula I and a non-metallic catalyst are subjected to staged heating reaction in solvent A, and after cooling, they are added to a solvent B of 2-10 times the mass for precipitation, and the obtained precipitate is vacuum dried to obtain a polymer of formula II; the staged heating reaction includes two stages, the first stage is a polymerization reaction at 70°C-90°C for 5h-15h, and a heat preservation of 30min-60min; the second stage is a polymerization reaction at 100°C-140°C for 1h-3h; the non-metallic catalyst is selected from one or more of azobisisoheptanitrile, azobisisobutyronitrile, azobisisovaleronitrile, dimethyl azobisisobutyrate and dibenzoyl peroxide; S2, under a protective atmosphere, the polymer of formula II structure is subjected to a deprotection reaction in solvent C under the action of an acid solution or an alkaline solution, and after cooling, it is added to a solvent D of 9-13 times the mass to precipitate, to obtain a crude product of a poly(4-hydroxystyrene) polymer of formula III structure; the acid solution is selected from one or more of a hydrochloric acid solution, a hydrobromic acid solution and a toluenesulfonic acid solution, and the mass fraction of the acid solution is 10%-40%; the alkaline solution is a sodium hydroxide solution, and the mass fraction of the alkaline solution is 5%-30%; S3, a crude product of a poly(4-hydroxystyrene) polymer of formula III is added to a solvent E, water is added under stirring and the stirring is continued for 20-60 minutes, the product is allowed to stand until stratification, the lower liquid solution is removed, and the washing is repeated 3-7 times, and the obtained upper solution is added to a solvent F of 2-6 times the mass to precipitate, and the obtained precipitate is vacuum dried to obtain a fine product of a poly(4-hydroxystyrene) polymer of formula III; the solvent E is selected from one or more of propylene glycol methyl ether acetate, n-butanol, ethyl acetate and n-butyl acetate; the mass ratio of the solvent E to water is (70-85): (15-30); the vacuum drying temperature is 40°C-60°C, and the time is 60min-150min; Wherein, formula I-formula III are as follows: wherein R is selected from -CH3, -C(CH3)3 or -COCH3; n is an integer from 20 to 85; p+q is 20-85, and p / (p+q) does not exceed 40%.
2. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S1, the solvent A is selected from one or more of tetrahydrofuran, propylene glycol methyl ether acetate, propylene glycol monomethyl ether, cyclohexane, benzene and toluene; and the solvent B is selected from one or more of water, n-hexane, methanol, isopropanol and n-heptane.
3. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S1, the mass ratio of the monomer of formula I, the non-metallic catalyst and the solvent A is (20-55):(0.1-3):(45-80).
4. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S1, the vacuum drying is carried out at a temperature of 30°C-80°C and for a time of 30 min-200 min.
5. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S2, the solvent C is selected from one or more of tetrahydrofuran, propylene glycol methyl ether acetate, propylene glycol monomethyl ether, cyclohexane, methanol and ethyl acetate; the solvent D is selected from one or more of water, n-hexane, isopropanol and n-heptane.
6. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S2, the mass ratio of the polymer of formula II, the acid solution or the alkaline solution, and the solvent C is (9-20):(0.5-20):(80-91).
7. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S2, the deprotection reaction temperature is 40°C-65°C, and the time is 1h-5h.
8. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S3, the solvent F is selected from one or more of water, n-hexane, isopropanol and n-heptane.
9. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S3, the mass ratio of the crude poly(4-hydroxystyrene) polymer of formula III to the solvent E is (10-30):(70-90).
10. The method for preparing a poly(4-hydroxystyrene) polymer according to claim 1, characterized in that: In S3, the rotation speed of the stirring condition is 200 rpm-800 rpm.