A methacrylate-styrene copolymer and its preparation method and application

Abstract

The present invention provides a methacrylate-styrene copolymer, a preparation method and an application thereof, belonging to the technical field of optical polymer preparation. The methacrylate-styrene copolymer is prepared by combining a hydroxyl and / or carbonyl-containing adamantyl methacrylate, methyl methacrylate and styrene monomers through a free radical copolymerization reaction, and limiting the molar fractions of the three monomers to a specific range, thereby obtaining an optical-grade methacrylate-styrene copolymer with excellent heat resistance. The copolymer simultaneously meets the requirements of high refractive index and high Abbe number and is suitable for use as a material for precision optical components.

Description

Technical Field

[0001] The invention belongs to the technical field of optical polymer preparation, and particularly 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 combines the advantages of 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, mirrors, and image sensors.

[0003] For optical polymer materials, the Lorentz equation describes the relationship between the polymer's refractive index and various parameters in its molecular structure. The Abbe number is also a key parameter for evaluating the material's dispersion. However, for traditional optical polymers, there is a general trade-off between the refractive index and the Abbe number: higher refractive index materials typically result in lower Abbe numbers. This problem also exists with current MS resins. Although the refractive index can reach 1.55, the Abbe number is only 35, resulting in severe dispersion. Therefore, it is necessary to design new molecular structures that can simultaneously meet the requirements of high refractive index and high Abbe number 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 high-refractive-index acrylic monomers to synthesize an acrylic ester polymer, which has high-refractive-index optical properties. The refractive index can reach up to 1.67. Based on the ratio of different monomers, acrylic co-esters with a refractive index within a certain range can be synthesized to produce high-refractive-index OCA that can match a wide range of optical instruments. However, this method uses more monomers, the formulation is more complicated, and the problem of reduced Abbe number is not taken into account, so the clarity may not be high.

[0005] For example, CN104945284A discloses a high Abbe number, ultra-light, wear-resistant resin material, lens, and preparation method thereof. The polymer resin is a polyurethane methacrylate prepolymer obtained by the reaction of isocyanate and hydroxyl-containing acrylate. Its wear resistance, temperature resistance, deformability, Abbe number, and thermal stability are effectively improved, the density is reduced, the structure is more flexible, the production method is highly controllable, no waste is discharged during the preparation process, and it can meet the preparation requirements of lens raw materials with different refractive index levels; 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 cannot meet both high refractive index and high Abbe number requirements at the same time.

[0006] In addition, the glass transition temperature (T g) is generally not higher than 115℃, and its 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 order to solve the above technical problems, there is still an urgent need 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 shortcomings of the prior art, the object of the present invention is to provide a methacrylate-styrene copolymer and its preparation method and application. 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 material for precision optical components.

[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 parts by mole 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 monomer in specific molar fractions, and are obtained by free radical copolymerization of the above three monomers in specific molar fractions. By introducing the adamantyl methacrylate containing hydroxyl and / or carbonyl groups into the polymerized monomer, on the one hand, the adamantane structure in the adamantyl methacrylate containing hydroxyl and / or carbonyl groups is introduced as a large sterically hindered side chain, which greatly increases the rotational hindrance within the molecular chain, thereby effectively improving the heat resistance of the obtained methacrylate-styrene copolymer. At the same time, since the adamantane structure is a high C / H ratio group with a high molar refractive index, it can also effectively improve the refractive index of the obtained methacrylate-styrene copolymer. 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 the hydrogen group on the adamantyl group is replaced by a hydroxyl group, the atomic dispersion [△R] of the hydrogen group is 0.023, while the atomic dispersion [△R] of the hydroxyl group is only 0.006, which significantly reduces the atomic dispersion of the resulting hydroxyl-containing adamantyl methacrylate. 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 also significantly reduces the atomic dispersion of the resulting carbonyl-containing adamantyl methacrylate. Both of these contribute to increasing the Abbe number of the resulting methacrylate-styrene copolymer. At the same time, the introduction of the hydroxyl group also brings about intramolecular and intermolecular hydrogen bonding interactions, further improving the heat resistance of the resulting methacrylate-styrene copolymer. Furthermore, the formation of the hydrogen bond network can induce dense stacking of the polymer chains, thereby reducing the free volume of the polymer and further increasing the refractive index of the resulting methacrylate-styrene copolymer.

[0015] In addition, a small amount of styrene monomer is added, on the one hand, to allow the large steric hindrance adamantyl methacrylate to react more evenly with the polymer chain, while improving the processing fluidity of the copolymer; on the other hand, it is to further increase the refractive index of the copolymer; however, if the amount of the styrene monomer added is too much, it will lead to more serious dispersion, so it needs to be controlled within an appropriate 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 parts by mole, 40 parts by mole, 50 parts by mole, 60 parts by mole, 70 parts by mole, 80 parts by mole, 90 parts by mole or 95 parts by mole, etc., preferably 40 to 85 parts by mole, and more preferably 53 to 73 parts by mole.

[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 to 45 mol parts, and more preferably 20 to 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 to 15 mol parts, and more preferably 7 to 12 mol parts.

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

[0020] And / or, it is 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 group 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 group 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 or a combination of at least two of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, dimethylstyrene, o-chlorostyrene, m-chlorostyrene or p-chlorostyrene.

[0025] Preferably, the raw materials for preparing the methacrylate-styrene copolymer further 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, dicumyl 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 is further preferably tert-butyl perbenzoate.

[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] The methacrylate-styrene copolymer provided by the present invention can be prepared by any of bulk polymerization, suspension polymerization, or solution polymerization. However, considering aspects such as product purity, post-processing, and environmental protection, the polymerization method is preferably bulk polymerization. Furthermore, as is known, since the system of bulk polymerization is relatively viscous and the polymerization heat is not easily dissipated, a bulk polymerization process with the addition of a small amount of solvent is preferably used to improve the transport capacity of the polymer solution. The amount of solvent added is 5-10% of the total feed weight, for example, 5%, 6%, 7%, 8%, 9%, or 10%.

[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 or a combination of at least two of toluene, ethylbenzene, xylene, methyl isobutyrate, N,N-dimethylformamide, tetrahydrofuran or ethyl acetate.

[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 hours, for example, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4 hours.

[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 pelletizing.

[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 additives 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 described in the first aspect to prepare a light guide plate, a lens, a mirror 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 combining a hydroxyl and / or carbonyl-containing adamantyl methacrylate, methyl methacrylate, and styrene monomers through a free radical copolymerization reaction, and limiting the molar fractions of the three monomers to a specific range. This yields an optical-grade methacrylate-styrene copolymer with excellent heat resistance. The copolymer simultaneously meets the requirements of a high refractive index and a high Abbe number, making it 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 way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely 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 implementation methods 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 its preparation method 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 the total mass of the three monomers (including MMA, 3-HAdMA and St), 2000 ppm of the total mass of the three monomers (including MMA, 3-HAdMA and St) and 8 wt% of toluene (including MMA, 3-HAdMA, St, tert-butyl perbenzoate and octyl mercaptan) were added to the raw material tank in sequence, and the mixture was thoroughly stirred and then continuously deoxygenated with N2 for 1 hour;

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

[0057] (3) The polymer solution after the reaction is continuously conveyed to a devolatilization 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; other substances, amounts, and preparation methods are the same as those in Example 1.

[0060] Example 3

[0061] A methacrylate-styrene copolymer, which differs from Example 1 in that the amount of MMA is 75 parts by mole, the amount of 3-HAdMA is 15 parts by mole, and the amount of St is 10 parts by mole; other substances, amounts, and preparation methods are 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, and the amount of St is 5 parts by mole; other substances, amounts, and preparation methods are the same as those in Example 1.

[0064] Example 5

[0065] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein 4-HAdMA is used in an equal molar fraction to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0066] Example 6

[0067] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein OAdMA is used in an equal molar fraction to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0068] Example 7

[0069] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein HOAdMA is used in equal molar proportions to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0070] Example 8

[0071] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein DHAdMA is used in equal molar proportions to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0072] Example 9

[0073] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein THAdMA is used in equal molar proportions to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0074] Example 10

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

[0076] Example 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; other substances, amounts, and preparation methods are the same as those in 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; other substances, amounts, and preparation methods are the same as those in Example 1.

[0080] Comparative Example 1

[0081] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein 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 the same as those in Example 1.

[0082] Comparative Example 2

[0083] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein 1-AdMA is used in an equal molar fraction to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0084] Comparative Example 3

[0085] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein MAdMA is used in equal molar proportions to replace 3-HAdMA, and other substances, amounts used, and preparation methods are the same as those in Example 1.

[0086] Comparative Example 4

[0087] A methacrylate-styrene copolymer is prepared in accordance with Example 1, wherein 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 the same as those in Example 1.

[0088] Performance testing:

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

[0090] Table 3

[0091]

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

[0093] According to 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. This indicates that the addition of the adamantyl methacrylate monomer does not affect the original light transmittance of the methacrylate-styrene copolymer and significantly improves the heat resistance.

[0095] (2) It can be seen from the data of Example 1 and Comparative Examples 1 to 3 that the Tg and refractive index of the obtained copolymer are both lower when no hydroxyl and / or carbonyl-containing adamantyl methacrylate monomer is added; and although the introduction of adamantyl methacrylate monomers without 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 embodiment of the present invention, but the scope of protection 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 fall within the scope of protection and disclosure 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 parts by mole of methyl methacrylate; 5 to 50 parts by mole of adamantyl methacrylate containing a hydroxyl group and / or a carbonyl group; 3 to 20 parts by mole of styrene monomer; 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, it is obtained by substituting at least one methylene group in the adamantane structure contained in 1-adamantyl methacrylate with a carbonyl group.

2. The methacrylate-styrene copolymer according to claim 1, 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.

3. 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.

4. 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, dicumyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, peroxydicarbonate (bis-2-phenoxyethyl ester), methyl ethyl ketone peroxide or peroxy-3,5,5-trimethylhexanoate, 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 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 of them.

6. 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.

7. 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.

8. The preparation method according to claim 7, characterized in that The polymerization reaction temperature is 110-150° C., the reaction time is 2-4 hours, and the pressure is 0.1-0.3 MPa.

9. An application, characterized in that: The application includes using the methacrylate-styrene copolymer according to any one of claims 1 to 6 to prepare a light guide plate, a lens, a mirror or an image sensor.

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