Methacrylate-styrene copolymer as well as preparation method and application thereof

Abstract

The invention provides a methacrylate-styrene copolymer as well as a preparation method and application thereof, and belongs to the technical field of optical polymer preparation. According to the methacrylate-styrene copolymer, adamantyl methacrylate containing hydroxyl and / or carbonyl, methyl methacrylate and a styrene monomer are subjected to a free radical copolymerization reaction and matched, and the mole fraction of the three is limited to be within a specific range; the optical-grade methacrylate-styrene copolymer with excellent heat resistance is obtained, meets the requirements of high refractive index and high Abbe number at the same time, and is suitable for being used as a precise optical component material.

Description

Technical Field

[0001] The invention belongs to the technical field of optical polymer preparation, and specifically relates to a methacrylate-styrene copolymer and a preparation method and application thereof. Background Art

[0002] Methyl methacrylate-styrene copolymer (MS resin) is polymerized with methyl methacrylate and styrene as the main raw materials. It has the advantages of both polymethyl methacrylate and polystyrene, and has excellent chemical resistance, light transmittance, and processability. In particular, its excellent optical properties make it an ideal carrier for optical materials such as light guide plates, lenses, lenses, and image sensors.

[0003] For optical polymer materials, the Lorentz equation gives the relationship between the refractive index of the polymer and the various parameters in its molecular structure, and the Abbe number is also a key parameter for judging the degree of dispersion of the material. However, there is a general trade-off between the refractive index and the Abbe number of traditional optical polymers, that is, high refractive index materials usually lead to lower Abbe numbers. The current MS resin also has this problem. Although the refractive index can reach 1.55, the Abbe number is only 35, and the dispersion is serious. Therefore, it is necessary to design a new molecular structure that can meet the requirements of high refractive index and high Abbe number at the same time for use in precision optical materials.

[0004] For example, CN115287023A discloses a high-refractive index OCA optical adhesive and a method for making the same. The adhesive uses a high-refractive index acrylic monomer to synthesize an acrylic ester polymer, which has high-refractive index optical properties. The refractive index can reach up to 1.67. According to the ratio of different monomers, acrylic co-esters with a refractive index in a certain range can be synthesized to produce a high-refractive index OCA that can match a wide range of optical instruments. However, this method uses more monomers, the ratio is more complicated, and the problem of reduced Abbe number is not taken into account, so the clarity may not be high.

[0005] For another example, CN104945284A discloses a high Abbe number ultra-light wear-resistant resin material, lens and preparation method thereof, wherein the polymer resin is a polyurethane methacrylate prepolymer obtained by the reaction of isocyanate and hydroxyl-containing acrylate, and its wear resistance, temperature resistance, deformability, Abbe number and thermal stability are effectively improved, density is reduced, structure is more flexible, production method is highly controllable, no waste is discharged during the preparation process, and the preparation requirements of lens raw materials with different refractive index levels can be met; although the Abbe number of the resin can reach 42, the refractive index is only 1.53, which is relatively low, and the Abbe number is reduced while the refractive index is increased, and it is impossible to simultaneously meet high refractive index and high Abbe number.

[0006] In addition, the glass transition temperature (T g) is generally not higher than 115℃, and the heat resistance is very limited. It is difficult to meet the use of special places that require high heat resistance, and the heat resistance needs to be improved urgently.

[0007] Therefore, in view of the above technical problems, it is still urgent to develop a methacrylate-styrene copolymer having both high refractive index and high Abbe number and excellent heat resistance. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a methacrylate-styrene copolymer and a preparation method and application thereof. The methacrylate-styrene copolymer can take into account both high refractive index and high Abbe number, and at the same time has excellent heat resistance, and is suitable for use as a precision optical component material.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a methacrylate-styrene copolymer, wherein the methacrylate-styrene copolymer is obtained by free radical copolymerization of the following raw materials in molar parts:

[0011] 30-92 mole parts of methyl methacrylate;

[0012] 5 to 50 parts by mole of adamantyl methacrylate containing a hydroxyl group and / or a carbonyl group;

[0013] 3 to 20 molar parts of styrene monomer.

[0014] The methacrylate-styrene copolymer provided by the present invention is of optical grade. The raw materials include methyl methacrylate, adamantyl methacrylate containing hydroxyl and / or carbonyl groups, and styrene monomers in specific molar fractions, and the above three monomers are subjected to free radical copolymerization reaction in specific molar fractions to obtain the copolymer. By introducing adamantyl methacrylate containing hydroxyl and / or carbonyl groups into the polymerized monomers, on the one hand, the adamantane structure in the adamantyl methacrylate containing hydroxyl and / or carbonyl groups is introduced as a large steric hindrance side chain, which greatly increases the rotation steric hindrance within the molecular chain, so that the heat resistance of the obtained methacrylate-styrene copolymer is effectively improved; at the same time, since the adamantane structure is a high C / H ratio group and has a high molar refractive index, the refractive index of the obtained methacrylate-styrene copolymer can also be effectively improved; on the other hand, the adamantyl methacrylate containing hydroxyl and / or carbonyl groups is limited to contain hydroxyl and / or carbonyl groups, which can effectively reduce atomic dispersion, for example When H on the adamantyl group is replaced by a hydroxyl group, since the atomic dispersion [△R] of H is 0.023, while the atomic dispersion [△R] of the hydroxyl group is only 0.006, the atomic dispersion of the obtained hydroxyl-containing adamantyl methacrylate can be significantly reduced. For example, when the methylene group on the adamantyl group is replaced by a carbonyl group, the atomic dispersion [△R] of the methylene group is 0.072, while the atomic dispersion [△R] of the carbonyl group is only 0.057, which can also significantly reduce the atomic dispersion of the obtained carbonyl-containing adamantyl methacrylate, which is helpful to improve the Abbe number of the obtained methacrylate-styrene copolymer. At the same time, the introduction of hydroxyl groups also brings about intramolecular and intermolecular hydrogen bond interactions, further improving the heat resistance of the obtained methacrylate-styrene copolymer. Furthermore, the formation of a hydrogen bond network can also induce dense stacking of polymer chains, thereby reducing the free volume of the polymer, so that the refractive index of the obtained methacrylate-styrene copolymer can be further improved.

[0015] In addition, a small amount of styrene monomers are added, on the one hand, to allow the large steric hindrance adamantyl methacrylate to react more evenly on the polymer chain and improve the processing fluidity of the copolymer; on the other hand, it is to further increase the refractive index of the copolymer; but if the amount of the styrene monomer added is too much, it will lead to more serious dispersion, so it is necessary to regulate it within a suitable range so that the refractive index of the copolymer is increased while the Abbe number does not decrease significantly.

[0016] The amount of methyl methacrylate may be 30 mol parts, 40 mol parts, 50 mol parts, 60 mol parts, 70 mol parts, 80 mol parts, 90 mol parts or 95 mol parts, etc., preferably 40 to 85 mol parts, and more preferably 53 to 73 mol parts.

[0017] The amount of the hydroxyl and / or carbonyl-containing adamantyl methacrylate can be 5 mol parts, 10 mol parts, 15 mol parts, 20 mol parts, 25 mol parts, 30 mol parts, 35 mol parts, 40 mol parts, 45 mol parts or 50 mol parts, etc., preferably 10-45 mol parts, and further preferably 20-35 mol parts.

[0018] The amount of the styrene monomer can be 3 mol parts, 4 mol parts, 5 mol parts, 6 mol parts, 7 mol parts, 8 mol parts, 9 mol parts, 10 mol parts, 11 mol parts, 12 mol parts, 14 mol parts, 16 mol parts, 18 mol parts or 20 mol parts, etc., preferably 5-15 mol parts, and more preferably 7-12 mol parts.

[0019] Preferably, the hydroxyl and / or carbonyl-containing adamantyl methacrylate is prepared by replacing at least one H in the adamantane structure contained in 1-adamantyl methacrylate with a hydroxyl group;

[0020] And / or, obtained by substituting at least one methylene group in the adamantane structure contained in 1-adamantyl methacrylate with a carbonyl group.

[0021] In the present invention, when at least one H in the adamantane structure contained in 1-adamantyl methacrylate is replaced by a hydroxyl group, a hydroxyl-containing adamantane methacrylate is obtained; when at least one methylene group in the adamantane structure contained in 1-adamantyl methacrylate is replaced by a carbonyl group, a carbonyl-containing adamantane methacrylate is obtained; when at least one H in the adamantane structure contained in 1-adamantyl methacrylate is replaced by a hydroxyl group and at the same time at least one methylene group in the adamantane structure contained in 1-adamantyl methacrylate is replaced by a carbonyl group, a hydroxyl- and carbonyl-containing adamantane methacrylate is obtained; wherein the structure of the 1-adamantyl methacrylate is as follows:

[0022] .

[0023] Preferably, the hydroxyl and / or carbonyl-containing adamantyl methacrylate includes any one of 4-oxo-1-adamantyl methacrylate, 3-hydroxy-6-oxo-1-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, 4-hydroxy-1-adamantyl methacrylate, 3,5-dihydroxy-1-adamantyl methacrylate or 3,5,7-trihydroxy-1-adamantyl methacrylate, or a combination of at least two thereof.

[0024] Preferably, the styrene-based monomer includes any one of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, dimethylstyrene, o-chlorostyrene, m-chlorostyrene or p-chlorostyrene, or a combination of at least two thereof.

[0025] Preferably, the raw materials for preparing the methacrylate-styrene copolymer also include a free radical initiator, and the free radical initiator mainly plays the role of providing initial free radicals for chain polymerization.

[0026] Preferably, the free radical initiator includes any one of dibenzoyl peroxide, dodecyl peroxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, lauroyl peroxide, tert-butyl perbenzoate, peroxydicarbonate (bis-2-phenoxyethyl ester), methyl ethyl ketone peroxide or tert-butyl peroxide-3,5,5-trimethylhexanoate, or a combination of at least two thereof, and tert-butyl perbenzoate is further preferred.

[0027] Preferably, the mass of the initiator accounts for 20-200 ppm of the total mass of the polymerized monomers of the methacrylate-styrene copolymer, for example, 20 ppm, 40 ppm, 60 ppm, 80 ppm, 100 ppm, 120 ppm, 140 ppm, 160 ppm, 180 ppm or 200 ppm.

[0028] Preferably, the raw materials for preparing the methacrylate-styrene copolymer also include a chain transfer agent; the chain transfer agent, also known as a molecular weight regulator, has a large chain transfer constant and is mainly used to regulate the molecular weight of the copolymer. It can also reduce the chain branching of the polymer, make the molecular weight distribution uniform and narrow, and stabilize the product quality.

[0029] Preferably, the chain transfer agent includes any one of n-butyl mercaptan, tert-butyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, n-dodecyl mercaptan or tert-dodecyl mercaptan, or a combination of at least two thereof, and n-octyl mercaptan is more preferably used.

[0030] Preferably, the mass of the chain transfer agent accounts for 500-3000 ppm of the total mass of the polymerized monomers of the methacrylate-styrene copolymer, for example, 500 ppm, 700 ppm, 900 ppm, 1100 ppm, 1300 ppm, 1500 ppm, 1700 ppm, 1900 ppm, 2100 ppm, 2300 ppm, 2500 ppm, 2700 ppm or 2900 ppm.

[0031] For the methacrylate-styrene copolymer provided by the present invention, its preparation method can be any one of bulk polymerization, suspension polymerization or solution polymerization. However, considering the purity of the product, post-processing, environmental protection, etc., the polymerization method is preferably bulk polymerization. It is well known that since the system of the bulk polymerization method is relatively viscous and the polymerization heat is not easy to diffuse, a bulk polymerization process with a small amount of solvent added is preferably used to improve the transmission capacity of the polymer solution. The amount of solvent added accounts for 5-10% of the total feed mass, for example, 5%, 6%, 7%, 8%, 9% or 10%, etc.

[0032] In the present invention, the total feed refers to all materials put into the reactor, including polymerization monomers, initiators and chain transfer agents; the polymerization monomers include methyl methacrylate, hydroxyl and / or carbonyl-containing adamantyl methacrylate and styrene monomers.

[0033] Preferably, the solvent includes any one of toluene, ethylbenzene, xylene, methyl isobutyrate, N,N-dimethylformamide, tetrahydrofuran or ethyl acetate, or a combination of at least two thereof.

[0034] Preferably, the weight average molecular weight of the methacrylate-styrene copolymer is 50,000 to 200,000, for example, 50,000, 70,000, 90,000, 110,000, 130,000, 150,000, 170,000, 190,000 or 200,000.

[0035] In a second aspect, the present invention provides a method for preparing a methacrylate-styrene copolymer, the preparation method comprising: subjecting methyl methacrylate, adamantyl methacrylate containing hydroxyl and / or carbonyl groups, a styrene-based monomer, an optional free radical initiator and an optional chain transfer agent to a polymerization reaction in a solvent to obtain the methacrylate-styrene copolymer as described in the first aspect.

[0036] Preferably, the polymerization reaction temperature is 110-150°C, for example, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C or 150°C.

[0037] Preferably, the polymerization reaction time is 2 to 4 h, for example, 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h or 4 h.

[0038] Preferably, the polymerization reaction pressure is 0.1-0.3 MPa, for example, 0.1 MPa, 0.12 MPa, 0.14 MPa, 0.16 MPa, 0.18 MPa, 0.2 MPa, 0.22 MPa, 0.24 MPa, 0.26 MPa, 0.28 MPa or 0.3 MPa.

[0039] Preferably, after the polymerization reaction is completed, the method further comprises the steps of devolatilization in a twin-screw devolatilization extruder and extrusion pelletization.

[0040] Preferably, the devolatilization temperature is 200-250°C, for example, 200°C, 210°C, 220°C, 230°C, 240°C or 250°C.

[0041] In addition, when the methacrylate-styrene copolymer is prepared by the above method, corresponding auxiliary agents may be added as needed, including but not limited to antioxidants, colorants, ultraviolet absorbers, antistatic agents, etc.

[0042] In a third aspect, the present invention provides an application, which comprises using the methacrylate-styrene copolymer as described in the first aspect to prepare a light guide plate, a lens, a mirror plate or an image sensor.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The methacrylate-styrene copolymer provided by the present invention is prepared by mixing adamantyl methacrylate containing hydroxyl and / or carbonyl groups, methyl methacrylate and styrene monomers through free radical copolymerization, and limiting the molar fractions of the three monomers within a specific range, thereby obtaining an optical grade methacrylate-styrene copolymer with excellent heat resistance, which satisfies the requirements of high refractive index and high Abbe number at the same time and is suitable for use as a material for precision optical components. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] (1) Some of the raw materials and their abbreviations involved in the following specific implementations are shown in Table 1:

[0047] Table 1

[0048]

[0049] (2) The relevant performance test methods involved in the following specific implementation methods are shown in Table 2:

[0050] Table 2

[0051]

[0052] The methacrylate-styrene copolymer and the preparation method thereof provided by the present invention are further described below through specific examples.

[0053] Example 1

[0054] A methacrylate-styrene copolymer, the preparation method of which comprises the following steps:

[0055] (1) 55 mol parts of MMA, 35 mol parts of 3-HAdMA, 10 mol parts of St, 80 ppm of tert-butyl peroxybenzoate (including MMA, 3-HAdMA and St), 2000 ppm of n-octyl mercaptan (including MMA, 3-HAdMA and St) and 8 wt% of toluene (including MMA, 3-HAdMA, St, tert-butyl peroxybenzoate and n-octyl mercaptan) were added to the raw material tank in sequence, and the mixture was thoroughly stirred and mixed, and then N was continuously passed through the raw material tank. 2 Deoxygenation for 1h;

[0056] (2) After deoxygenation, the mixed raw material liquid is continuously transported to the fully mixed flow reactor, the liquid level is maintained at 30%, the reactor temperature is 125°C, the pressure in the reactor is 0.2MPa, and the average residence time is 2.5h;

[0057] (3) The polymer solution after the reaction is continuously conveyed to a devolatilizing extruder at a temperature of 240° C. and pelletized after devolatilization to obtain the methacrylate-styrene copolymer.

[0058] Example 2

[0059] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 65 parts by mole, the amount of 3-HAdMA is 25 parts by mole, and the amount of St is 10 parts by mole, and other substances, amounts and preparation methods are all the same as Example 1.

[0060] Example 3

[0061] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 75 molar parts, the amount of 3-HAdMA is 15 molar parts, and the amount of St is 10 molar parts. Other substances, amounts and preparation methods are all the same as those in Example 1.

[0062] Example 4

[0063] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 60 parts by mole, the amount of 3-HAdMA is 35 parts by mole, the amount of St is 5 parts by mole, and other substances, amounts and preparation methods are all the same as Example 1.

[0064] Example 5

[0065] A methacrylate-styrene copolymer is different from Example 1 in that 4-HAdMA is used in equal molar proportion to replace 3-HAdMA, and other substances, amounts used and preparation methods are all the same as those of Example 1.

[0066] Example 6

[0067] A methacrylate-styrene copolymer, which differs from Example 1 in that 3-HAdMA is replaced by OAdMA in equal molar fractions, and other substances, amounts used and preparation methods are all the same as those of Example 1.

[0068] Example 7

[0069] A methacrylate-styrene copolymer, which differs from Example 1 in that 3-HAdMA is replaced by HOAdMA in equal molar fractions, and other substances, amounts used and preparation methods are all the same as those in Example 1.

[0070] Example 8

[0071] A methacrylate-styrene copolymer, which differs from Example 1 in that DHAdMA is used in equal molar fractions to replace 3-HAdMA, and other substances, amounts used and preparation methods are all the same as those of Example 1.

[0072] Example 9

[0073] A methacrylate-styrene copolymer, which differs from Example 1 in that 3-HAdMA is replaced by THAdMA in equal molar fractions, and other substances, amounts used and preparation methods are all the same as those of Example 1.

[0074] Example 10

[0075] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 85 molar parts, the amount of 3-HAdMA is 5 molar parts, and the amount of St is 10 molar parts. Other substances, amounts and preparation methods are all the same as those in Example 1.

[0076] Embodiment 11

[0077] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 40 parts by mole, the amount of 3-HAdMA is 50 parts by mole, and the amount of St is 10 parts by mole, and other substances, amounts and preparation methods are all the same as Example 1.

[0078] Example 12

[0079] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 55 parts by mole, the amount of 3-HAdMA is 30 parts by mole, and the amount of St is 15 parts by mole, and other substances, amounts and preparation methods are all the same as Example 1.

[0080] Comparative Example 1

[0081] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 90 parts by mole, the amount of St is 10 parts by mole, and 3-HAdMA is not added; other substances, amounts and preparation methods are all the same as those of Example 1.

[0082] Comparative Example 2

[0083] A methacrylate-styrene copolymer is different from Example 1 in that 1-AdMA is used in equal molar proportion to replace 3-HAdMA, and other substances, amounts and preparation methods are all the same as those in Example 1.

[0084] Comparative Example 3

[0085] A methacrylate-styrene copolymer is different from Example 1 in that 3-HAdMA is replaced by MAdMA in equal molar fractions, and other substances, amounts used and preparation methods are all the same as those in Example 1.

[0086] Comparative Example 4

[0087] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of 3-HAdMA is 90 parts by mole, the amount of St is 10 parts by mole, and MMA is not added; other substances, amounts and preparation methods are all the same as those of Example 1.

[0088] Performance Test:

[0089] The weight average molecular weight, glass transition temperature (Tg), refractive index, light transmittance and Abbe number of the methacrylate-styrene copolymers provided in Examples 1 to 12 and Comparative Examples 1 to 4 were tested, and the test results are shown in Table 3:

[0090] Table 3

[0091]

[0092] Note: “ / ” means unable to test, no data.

[0093] From the data in Table 3, we can see that:

[0094] (1) The methacrylate-styrene copolymers provided in Examples 1 to 12 have both a high refractive index and a high Abbe number, and both a high light transmittance and a high glass transition temperature, indicating that the addition of adamantyl methacrylate monomers does not affect the original light transmittance of the methacrylate-styrene copolymer, and has a significant effect on improving the heat resistance;

[0095] (2) It can be seen from the data of Example 1 and Comparative Examples 1 to 3 that the absence of the addition of adamantyl methacrylate containing hydroxyl and / or carbonyl groups results in a lower Tg and refractive index of the obtained copolymer; and although the introduction of adamantyl methacrylate monomers not containing hydroxyl or carbonyl groups significantly improves the heat resistance of the obtained copolymer, the Abbe number is still low, and both cannot meet the requirements of high refractive index and high Abbe number.

[0096] (3) In Comparative Example 4, the amount of adamantyl methacrylate containing hydroxyl and / or carbonyl groups added is too high. Due to its large steric hindrance, the polymerization efficiency is too low to obtain the target copolymer. Even if the polymerization time is extended to obtain a copolymer, the Tg of the obtained copolymer will be greater than 180°C, and the fluidity is poor, making it difficult to produce smoothly.

[0097] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A methacrylate-styrene copolymer, characterized in that: The methacrylate-styrene copolymer is obtained by free radical copolymerization of the following raw materials in molar parts: 30-92 mole parts of methyl methacrylate; 5 to 50 parts by mole of adamantyl methacrylate containing a hydroxyl group and / or a carbonyl group; 3 to 20 molar parts of styrene monomer.

2. The methacrylate-styrene copolymer according to claim 1, characterized in that The adamantyl methacrylate containing a hydroxyl group and / or a carbonyl group is prepared by replacing at least one H in the adamantane structure contained in 1-adamantyl methacrylate with a hydroxyl group; And / or, obtained by substituting at least one methylene group in the adamantane structure contained in 1-adamantyl methacrylate with a carbonyl group.

3. The methacrylate-styrene copolymer according to claim 2, characterized in that The hydroxyl and / or carbonyl-containing adamantyl methacrylate includes any one of 4-oxo-1-adamantyl methacrylate, 3-hydroxy-6-oxo-1-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, 4-hydroxy-1-adamantyl methacrylate, 3,5-dihydroxy-1-adamantyl methacrylate or 3,5,7-trihydroxy-1-adamantyl methacrylate, or a combination of at least two thereof.

4. The methacrylate-styrene copolymer according to claim 1, characterized in that The styrene monomers include any one of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, dimethylstyrene, o-chlorostyrene, m-chlorostyrene or p-chlorostyrene, or a combination of at least two thereof.

5. The methacrylate-styrene copolymer according to claim 1, characterized in that The raw materials for preparing the methacrylate-styrene copolymer also include a free radical initiator; The free radical initiator includes any one of dibenzoyl peroxide, dodecyl peroxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, lauroyl peroxide, tert-butyl perbenzoate, dicarbonic acid peroxide (bis-2-phenoxyethyl ester), methyl ethyl ketone peroxide or tert-butyl peroxide-3,5,5-trimethylhexanoate, or a combination of at least two thereof.

6. The methacrylate-styrene copolymer according to claim 1, characterized in that The raw materials for preparing the methacrylate-styrene copolymer also include a chain transfer agent; The chain transfer agent includes any one of n-butyl mercaptan, tert-butyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, n-dodecyl mercaptan or tert-dodecyl mercaptan, or a combination of at least two thereof.

7. The methacrylate-styrene copolymer according to claim 1, characterized in that: The weight average molecular weight of the methacrylate-styrene copolymer is 50,000 to 200,000.

8. A method for preparing a methacrylate-styrene copolymer, characterized in that: The preparation method comprises: polymerizing methyl methacrylate, adamantyl methacrylate containing hydroxyl and / or carbonyl groups, a styrene monomer, an optional free radical initiator and an optional chain transfer agent in a solvent to obtain the methacrylate-styrene copolymer according to any one of claims 1 to 6.

9. The preparation method according to claim 7, characterized in that: The polymerization reaction is carried out at a temperature of 110-150° C., a time of 2-4 hours, and a pressure of 0.1-0.3 MPa.

10. An application, characterized in that: The application includes using the methacrylate-styrene copolymer according to any one of claims 1 to 7 to prepare a light guide plate, a lens, a mirror or an image sensor.

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