Negative photoresist composition as well as preparation method and application thereof

Abstract

The invention provides a negative photoresist composition as well as a preparation method and application thereof. The negative photoresist composition comprises acrylic copolymer resin, an acrylic monomer and a first initiator, the acrylic copolymer resin comprises a first structural unit, a second structural unit and a third structural unit. The negative photoresist composition has the advantages of favorable aging resistance, high refractive index, high transmittance, high adhesive force and high hardness.

Description

Technical Field

[0001] The invention relates to the technical field of optical materials, and in particular to a negative photoresist composition and a preparation method and application thereof. Background Art

[0002] In the field of optical material technology, microlens is an important optical element widely used in display devices and image sensors. The main function of microlens is to converge or diverge light to achieve precise control of light and improve the transmittance of light. The performance of microlens, such as refractive index, transmittance and anti-aging performance, directly affects the performance of display devices and image sensors. Therefore, the development of microlens materials with high refractive index, high transmittance and excellent anti-aging performance is of great significance to improve the performance of display devices and image sensors.

[0003] Positive photoresist compositions contain the photosensitizer diazonaphthoquinone. Since the azo group of diazonaphthoquinone is red, the light transmittance of positive photoresist compositions is low. Therefore, using negative photoresist compositions to form microlenses is a hot topic in research. However, the refractive index of negative photoresist compositions is relatively low.

[0004] The existing technology mainly increases the refractive index of acrylic resin by introducing special functional groups, for example, by introducing heteroatoms such as sulfur and halogen, thereby improving the refractive index of negative photoresist composition. However, these methods will lead to a decrease in the anti-aging performance of acrylic resin and negative photoresist composition composed of it, especially after high-temperature thermal aging, its transmittance and anti-yellowing performance will be significantly reduced. In addition, the adhesion and hardness of the negative photoresist composition also need to be further improved.

[0005] Therefore, how to make the negative photoresist composition have high refractive index, high adhesion and high hardness without sacrificing the anti-aging performance and transmittance of the negative photoresist composition is an important challenge facing the current technology. Summary of the invention

[0006] The present invention provides a negative photoresist composition and a preparation method and application thereof. The negative photoresist composition has good anti-aging performance, high refractive index, high transmittance, high adhesion and high hardness, and effectively overcomes the defects of the prior art.

[0007] The present invention provides a negative photoresist composition, comprising an acrylic copolymer resin, an acrylic monomer and a first initiator; the acrylic copolymer resin comprises a first structural unit, a second structural unit and a third structural unit; the first structural unit is shown in Formula 1:

[0008] Formula 1,

[0009] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, and n1 is any integer from 0 to 10.

[0010] Formula 1-1, Formula 1-2,

[0011] The second structural unit is shown in Formula 2:

[0012] Formula 2,

[0013] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, and n2 is any integer from 0 to 10.

[0014] Formula 1-1, Formula 1-2;

[0015] The structure of the third structural unit is shown in Formula 3:

[0016] Formula 3,

[0017] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-1 and Formula 3-2, and n3 is any integer from 0 to 10,

[0018] Formula 1-1, Formula 1-2, Formula 3-1,

[0019] Formula 3-2, Formula 3-3.

[0020] According to one embodiment of the present invention, the first structural unit includes one or more of the structural units shown in Formula 4-1, Formula 4-2, and Formula 4-3; and / or, the second structural unit includes one or more of the structural units shown in Formula 5-1, Formula 5-2, and Formula 5-3; and / or, the third structural unit includes one or more of the structural units shown in Formula 6-1, Formula 6-2, and Formula 6-3; and / or, the weight average molecular weight of the acrylic copolymer resin is 500 g / mol to 100000 g / mol; and / or, the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 5%-95%.

[0021] According to one embodiment of the present invention, the acrylic copolymer resin is copolymerized by a monomer raw material including a first acrylate monomer, a second acrylate monomer, and a third acrylate monomer; preferably, the structure of the first acrylate monomer is as shown in Formula 7; preferably, the structure of the second acrylate monomer is as shown in Formula 8; preferably, the structure of the third acrylate monomer is as shown in Formula 9; preferably, the mass percentage of the first acrylate monomer in the monomer raw material is 5% to 95%; preferably, the mass percentage of the second acrylate monomer in the monomer raw material is 5% to 95%; preferably, the mass percentage of the third acrylate monomer in the monomer raw material is 5% to 95%.

[0022] According to one embodiment of the present invention, the first acrylate monomer includes one or more of the compounds shown in Formula 10-1, Formula 10-2, and Formula 10-3; and / or, the second acrylate monomer includes one or more of the compounds shown in Formula 11-1, Formula 11-2, and Formula 11-3; and / or, the third acrylate monomer includes one or more of the compounds shown in Formula 12-1, Formula 12-2, and Formula 12-3.

[0023] According to one embodiment of the present invention, the acrylic monomer includes a (meth) acrylate monomer containing at least two C=C groups; the negative photoresist composition satisfies: 0<a≤3, a is the mass ratio of the acrylic monomer to the acrylic copolymer resin, preferably 0.5≤a≤2, and further preferably 0.8≤a≤1.5; and / or, the first initiator includes one or more of a photoinitiator, a thermal initiator, and a thermal acid generator; and / or, the negative photoresist composition satisfies: 0<b≤0.5, b is the mass ratio of the first initiator to the acrylic copolymer resin, preferably 0.01≤b≤0.1; and / or, the negative photoresist composition further includes one or more of an additive and a solvent, the additive includes one or more of a silane coupling agent and a leveling agent; preferably, the mass ratio of the additive to the acrylic copolymer resin is 0.001~0.1; preferably, the solvent includes propylene glycol monomethyl ether acetate.

[0024] According to one embodiment of the present invention, the (meth)acrylate monomer containing at least two C=C groups includes one or more of a (meth)acrylate monomer containing two C=C groups, a (meth)acrylate monomer containing three C=C groups and a (meth)acrylate monomer containing more than three C=C groups; and / or, the photoinitiator includes one or more of O-acyl oxime compounds, acyloin compounds, acyloin ether compounds, acetophenone compounds, benzophenone compounds, quinone compounds, halogen compounds, and acylphosphine oxide compounds; and / or, the thermal initiator includes one or more of peroxides and azo compounds; and / or, the thermal acid generator includes a sulfonium salt.

[0025] Another aspect of the present invention provides a method for preparing the above-mentioned negative photoresist composition, comprising the following steps: mixing a first initiator, an acrylic monomer and an acrylic copolymer resin to obtain the negative photoresist composition; preferably, the process of mixing the first initiator, the acrylic monomer and the acrylic copolymer resin comprises: mixing the first initiator, an additive, the acrylic monomer and the acrylic copolymer resin, and then adding a solvent thereto to obtain the negative photoresist composition.

[0026] Another aspect of the present invention provides a structural member, comprising the negative photoresist composition or a cured product formed by curing the negative photoresist composition prepared according to the preparation method of the negative photoresist composition.

[0027] According to one embodiment of the present invention, the refractive index of the cured product is 1.55-1.65; and / or the transmittance of the cured product after heat aging at 150±5° C. for 240±2 hours is greater than or equal to 95%.

[0028] Another aspect of the present invention provides a method for preparing the above-mentioned structural part, comprising the following steps: subjecting a negative photoresist composition to a molding process to obtain a molding product; sequentially exposing and developing the molding product to obtain the structural part; wherein the developer comprises an alkali solution.

[0029] The implementation of the present invention has at least the following beneficial effects: the negative photoresist composition of the present invention comprises an acrylic copolymer resin, an acrylic monomer and a first initiator; the acrylic copolymer resin comprises a first structural unit shown in Formula 1, a second structural unit shown in Formula 2, and a third structural unit shown in Formula 3, so that the negative photoresist composition has good anti-aging performance. The negative photoresist composition has good anti-aging performance, high refractive index, high transmittance, high adhesion and high hardness. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The embodiment of the present invention provides a negative photoresist composition, including an acrylic copolymer resin, an acrylic monomer and a first initiator; the acrylic copolymer resin includes a first structural unit, a second structural unit, and a third structural unit; the first structural unit is shown in Formula 1:

[0032] Formula 1,

[0033] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, and n1 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0034] Formula 1-1, Formula 1-2;

[0035] The second structural unit is shown in Formula 2:

[0036] Formula 2,

[0037] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, and n2 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0038] Formula 1-1, Formula 1-2;

[0039] The structure of the third structural unit is shown in Formula 3:

[0040] Formula 3;

[0041] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-2, and Formula 3-3, and n3 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0042] Formula 1-1, Formula 1-2, Formula 3-1,

[0043] Formula 3-2, Formula 3-3.

[0044] Exemplarily, the acrylic copolymer resin may include a compound represented by Formula 13:

[0045] Formula 13,

[0046] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-2, and Formula 3-3, n1 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, n2 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, n3 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0047] Formula 1-1, Formula 1-2, Formula 3-1,

[0048] Formula 3-2, Formula 3-3.

[0049] According to the inventor's research, the acrylic copolymer resin containing the first structural unit, the second structural unit, and the third structural unit can increase the refractive index of the negative photoresist composition, thereby improving the performance of the display device and the image sensor, enabling it to more accurately control the convergence and divergence of light, thereby improving the quality of the image and the display effect. Secondly, the acrylic copolymer resin containing the first structural unit, the second structural unit, and the third structural unit can make the negative photoresist composition have excellent transmittance, and even after high-temperature thermal aging, it still has a high transmittance, which is beneficial to prolonging the service life of the display device and the image sensor.

[0050] Among them, the first structural unit, the second structural unit, and the third structural unit are repeating units of the acrylic copolymer resin, all of which contain aromatic groups such as benzene rings. Among them, the first structural unit mainly plays a role in adjusting the refractive index, so that the negative photoresist composition has a higher refractive index, the second structural unit mainly plays a role in developing adjustment, which is beneficial to improving the performance of display devices and image sensors, and the third structural unit mainly plays a role in curing and cross-linking, increasing the hardness and chemical solvent resistance of the acrylic copolymer resin, thereby improving the anti-aging performance and hardness of the negative photoresist composition.

[0051] The negative photoresist composition in the embodiment of the present invention includes a first initiator, an acrylic monomer and an acrylic copolymer resin containing a first structural unit, a second structural unit and a third structural unit. The negative photoresist composition has good anti-aging performance, high refractive index, high adhesion and high hardness performance, which is specifically reflected in that the cured product of the negative photoresist composition has good anti-aging performance, high refractive index, high adhesion and high hardness performance.

[0052] In some embodiments, the first structural unit includes one or more of the structural units shown in Formula 4-1, Formula 4-2, and Formula 4-3:

[0053] Formula 4-1,

[0054] Formula 4-2,

[0055] Formula 4-3;

[0056] The second structural unit includes one or more of the structural units shown in Formula 5-1, Formula 5-2, and Formula 5-3:

[0057] Formula 5-1, Formula 5-2

[0058] Formula 5-3;

[0059] The third structural unit includes one or more of the structural units shown in Formula 6-1, Formula 6-2, and Formula 6-3:

[0060] Formula 6-1, Formula 6-2

[0061] Formula 6-3.

[0062] In some embodiments, the weight average molecular weight of the acrylic copolymer resin is 500 g / mol to 100,000 g / mol, for example, 500 g / mol, 1,000 g / mol, 5,000 g / mol, 10,000 g / mol, 20,000 g / mol, 50,000 g / mol, 80,000 g / mol, 100,000 g / mol or a range consisting of any two of them, which is beneficial to the curing of the negative photoresist composition.

[0063] In some embodiments, the mass percentage of acrylic copolymer resin in the negative photoresist composition is 5% to 95%, for example, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95% or a range composed of any two of them, which is beneficial for the negative photoresist composition to have both good anti-aging properties and high transmittance and refractive index.

[0064] In some embodiments, the acrylic copolymer resin is obtained by copolymerizing a monomer raw material including a first acrylic ester monomer, a second acrylic ester monomer, and a third acrylic ester monomer.

[0065] Among them, the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer all contain unsaturated bonds, specifically carbon-carbon double bonds. In the copolymerization reaction, the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are copolymerized through the carbon-carbon double bonds to form an acrylic copolymer resin. The first acrylate monomer, the second acrylate monomer, and the third acrylate monomer correspondingly form the first structural unit, the second structural unit, and the third structural unit in the acrylic copolymer resin.

[0066] In some embodiments, the structure of the first acrylate monomer is shown in Formula 7, which is used to form the first structural unit:

[0067] Formula 7,

[0068] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, and n1 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0069] Formula 1-1, Formula 1-2;

[0070] The structure of the second acrylate monomer is shown in Formula 8, which is used to form the second structural unit:

[0071] Formula 8,

[0072] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, and n2 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0073] Formula 1-1, Formula 1-2;

[0074] The structure of the third acrylate monomer is shown in Formula 9, and is used to form the third structural unit:

[0075] Formula 9,

[0076] Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-2, and Formula 3-3, and n3 is any integer from 0 to 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

[0077] Formula 1-1, Formula 1-2, Formula 3-1,

[0078] Formula 3-2, Formula 3-3.

[0079] In some embodiments, the mass percentage of the first acrylate monomer to the monomer raw material is 5% to 95%, for example 5%, 6%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 86%, 88%, 90%, 92%, 95% or a range consisting of any two thereof.

[0080] In addition, the mass percentage of the second acrylate monomer in the monomer raw material is 5% to 95%, for example, 5%, 6%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 86%, 88%, 90%, 92%, 95% or a range consisting of any two thereof.

[0081] In addition, the mass percentage of the third acrylate monomer in the monomer raw material is 5% to 95%, for example, 5%, 6%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 86%, 88%, 90%, 92%, 95% or a range consisting of any two thereof.

[0082] In some embodiments, the first acrylate monomer includes one or more of the compounds shown in Formula 10-1, Formula 10-2, and Formula 10-3:

[0083] Formula 10-1,

[0084] Formula 10-2,

[0085] Formula 10-3;

[0086] The second acrylate monomer includes one or more compounds represented by Formula 11-1, Formula 11-2, and Formula 11-3:

[0087] Formula 11-1, Formula 11-2,

[0088] Formula 11-3;

[0089] The third acrylate monomer includes one or more compounds represented by Formula 12-1, Formula 12-2, and Formula 12-3:

[0090] Formula 12-1, Formula 12-2,

[0091] Formula 12-3.

[0092] In some embodiments, the acrylic monomer includes a (meth)acrylate monomer containing at least two C=C groups, which is beneficial to further improve the anti-aging performance and adhesion of the negative photoresist composition.

[0093] In addition, the negative photoresist composition satisfies: 0<a≤3, a is the mass ratio of acrylic monomer to acrylic copolymer resin, for example 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 18, 2, 2.5, 3 or a range consisting of any two of them, preferably 0.5≤a≤2, further preferably 0.8≤a≤1.5, which is conducive to forming a negative photoresist composition with high mechanical strength and excellent adhesion.

[0094] In some embodiments, the first initiator includes one or more of a photoinitiator, a thermal initiator, and a thermal acid generator.

[0095] In specific implementation, the negative photoresist composition satisfies: 0<b≤0.5, b is the mass ratio of the first initiator to the acrylic copolymer resin, for example 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5 or a range composed of any two of them, preferably 0.01≤b≤0.1, which is beneficial to improving the heat resistance, solvent resistance and pattern shape controllability of the negative photoresist composition after development.

[0096] In some embodiments, the negative photoresist composition further comprises one or more of an additive and a solvent, and the additive comprises one or more of a silane coupling agent and a leveling agent.

[0097] In some embodiments, the mass ratio of the additive to the acrylic copolymer resin is 0.001-0.1, for example, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 or a range consisting of any two thereof.

[0098] Specifically, the silane coupling agent includes one or more of a silane coupling agent having a carboxyl group, a silane coupling agent having a methyl propyl group, a silane coupling agent having an isocyanate group, and a silane coupling agent having an epoxy group. For example, the silane coupling agent may include one or more of trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 2-(3',4'-epoxycyclohexyl)ethyltrimethoxysilane.

[0099] In addition, the mass ratio of the silane coupling agent to the acrylic copolymer resin is 0 to 0.1, for example, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.08, 0.1 or a range consisting of any two of them, preferably 0.001 to 0.05, for improving the adhesion between the cured product of the photoresist composition and the substrate.

[0100] In a specific implementation, the leveling agent includes one or more of a fluorine-based surfactant and a silicon-based surfactant, for example, BYK-333 (manufactured by BYKCHEMIE), R-08 (manufactured by DIC), R-475 (manufactured by DIC), R-30 (manufactured by DIC), BM-1000 (manufactured by BMCHEMIE), BM-1100 (manufactured by BMCHEMIE), FLUORADE FC-135 (manufactured by Sumitomo 3M), FLUORADE FC-170C (manufactured by Sumitomo 3M), FLUORADE FC-430 (manufactured by Sumitomo 3M), FLUORADE FC-431 (manufactured by Sumitomo 3M), SAFLON S-112 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-113 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-131 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-141 (manufactured by Asahi Glass Co., Ltd.), Saflon S-145 (manufactured by Asahi Glass Co., Ltd.), Saflon S-382 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-101 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-102 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-103 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-104 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-105 (manufactured by Asahi Glass Co., Ltd.), Saflon SC-106 (manufactured by Asahi Glass Co., Ltd.), SH-28PA (manufactured by Toray Silicone Co., Ltd.), SH-190 (manufactured by Toray Silicone Co., Ltd.), SH-193 (manufactured by Toray Silicone Co., Ltd.), SZ-6032 (manufactured by Toray Silicone Co., Ltd.), SF-8428 (manufactured by Toray Silicone Co., Ltd.), DC-57 (manufactured by Toray Silicone Co., Ltd.), DC190 (manufactured by Toray Silicone Co., Ltd.). In addition, the mass ratio of the leveling agent to the acrylic copolymer resin is 0.001 to 0.05, preferably 0.001 to 0.02, for example, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, 0.02 or a range consisting of any two thereof, which is conducive to coating the negative photoresist composition on the substrate.

[0101] In some embodiments, the solvent comprises an organic solvent comprising propylene glycol monomethyl ether acetate.

[0102] In some embodiments, the (meth)acrylate monomer containing at least two C=C groups includes one or more of a (meth)acrylate monomer containing two C=C groups, a (meth)acrylate monomer containing three C=C groups, and a (meth)acrylate monomer containing more than three C=C groups.

[0103] Generally, the number of C=C groups in the (meth)acrylate monomer containing at least two C=C groups is not particularly limited, but (meth)acrylate monomers containing two or more C=C groups and (meth)acrylate monomers containing three or more C=C groups have good reactivity, are conducive to the curing of the negative photoresist composition, and the strength of the cured product of the negative photoresist composition is higher. Therefore, (meth)acrylate monomers containing two or more C=C groups and (meth)acrylate monomers containing three or more C=C groups are preferred, and (meth)acrylate monomers containing three or more C=C groups are further preferred.

[0104] In the present invention, the (meth)acrylic acid ester monomers include methacrylic acid ester monomers and / or acrylic acid ester monomers.

[0105] Specifically, the (meth)acrylate monomer containing two C=C groups includes one or more of ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, bisphenoxyethanol fluorene diacrylate, and bisphenoxyethanol fluorene dimethacrylate.

[0106] The (meth)acrylate monomer containing three C=C groups includes one or more of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and pentaerythritol trimethacrylate.

[0107] The (meth)acrylate monomer containing three or more C=C groups includes one or more of pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tris(2-acryloyloxyethyl)phosphate, and tris(2-methacryloyloxyethyl)phosphate.

[0108] In some embodiments, the photoinitiator includes one or more of O-acyl oxime compounds, acyloin compounds, acyloin ether compounds, acetophenone compounds, benzophenone compounds, quinone compounds, halogen compounds, and acylphosphine oxide compounds.

[0109] In a specific implementation, the O-acyl oxime compound includes ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetoxime), ethyl ketone-1-[9-ethyl-6-[2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl]-9H-carbazole-3-yl]-1-(O-acetoxime), 1-[9-ethyl-6-benzoyl-9H-carbazole-3-yl]-1,2-nonane-2-oxime-O-benzoate, 1-[9-ethyl-6- Benzoyl-9H-carbazol-3-yl]-1,2-nonane-2-oxime-O-acetate, 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-1,2-pentane-2-oxime-O-acetate, 1-[9-ethyl-6-benzoyl-9H-carbazol-3-yl]-octane-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9 one or more of]-1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazole-3-yl]-ethane-1-one oxime-O-benzoate; one or more of acyloin compounds including benzoin and anisole; one or more of acyloin ether compounds including benzoin methyl ether, benzoin ethyl ether and benzoin-propyl ether; one or more of acetophenone compounds including acetophenone, p-dimethylaminoacetophenone, 2-hydroxy-1,2-di(2-methylphenyl)ethyl Ketone, p-methoxyacetophenone; benzophenone compounds include one or more of α,α'-dimethoxyacetoxybenzophenone and 4,4-bis-(diethylamino)-benzophenone; quinone compounds include one or more of anthraquinone and 1,4-naphthoquinone; halogen compounds include one or more of phenacyl chloride, tribromomethylphenyl sulfone and tris(trichloromethyl)-s-triazine; acylphosphine oxide compounds include one or more of 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0110] In some embodiments, the thermal initiator includes one or more of peroxides and azo compounds, the peroxide compound includes one or more of benzoyl peroxide and di-tert-butyl peroxide, and the azo compound includes azobisisobutylcyanide.

[0111] In a specific implementation, the thermal acid generator includes a sulfonium salt.

[0112] The embodiment of the present invention further provides a method for preparing the above-mentioned negative photoresist composition, comprising the following steps: mixing a first initiator, an acrylic monomer and an acrylic copolymer resin to obtain a negative photoresist composition.

[0113] In some embodiments, the process of mixing the first initiator, acrylic monomer and acrylic copolymer resin includes: after mixing the first initiator, additives, acrylic monomer and acrylic copolymer resin, adding a solvent thereto to obtain a negative photoresist composition.

[0114] In a specific implementation, a first acrylate monomer, a second acrylate monomer, and a third acrylate monomer are first synthesized; then, the monomer raw materials including the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are copolymerized under the action of a second initiator to obtain an acrylic copolymer resin; after the first initiator, the additive, the acrylic monomer, and the acrylic copolymer resin are mixed, a solvent is added thereto to obtain a mixture, and the viscosity of the mixture is controlled to be 3 cPs-20 cPs, for example, 3 cPs, 5 cPs, 8 cPs, 10 cPs, 13 cPs, 15 cPs, 18 cPs, 20 cPs or a range consisting of any two thereof, to obtain a negative photoresist composition.

[0115] The second initiator includes one or more of azo compounds and peroxides, the azo compounds include one or more of azobisisobutyl cyanide and azobisisoheptyl cyanide, and the peroxide includes benzoyl peroxide.

[0116] An embodiment of the present invention further provides a structural component, comprising the negative photoresist composition or a cured product formed by curing the negative photoresist composition prepared according to the preparation method of the negative photoresist composition.

[0117] In some embodiments, the refractive index of the cured product is 1.55-1.65, for example, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, or a range consisting of any two thereof.

[0118] In addition, the transmittance of the cured product after heat aging at 150±5°C for 240±2 hours is greater than or equal to 95%, for example, greater than or equal to 95%, greater than or equal to 96%, greater than or equal to 97%, greater than or equal to 98%, greater than or equal to 99%, greater than or equal to 99.5%, or a range consisting of any two thereof.

[0119] An embodiment of the present invention also provides a method for preparing the above-mentioned structural part, comprising the following steps: subjecting a negative photoresist composition to a molding process to obtain a molding product; sequentially exposing and developing the molding product to obtain a structural part; wherein the developer comprises an alkaline solution.

[0120] In specific implementation, the negative photoresist composition is subjected to molding treatment and exposure, and then developed with a developer. During the exposure process, a solid-containing reaction occurs in the negative photoresist composition, and the unexposed portion is dissolved and removed by the developer, leaving a negative image of the exposed portion.

[0121] The present invention is further described below through specific embodiments.

[0122] Example 1

[0123] 1. Synthesis of the first acrylate monomer

[0124] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, add 240 g of tetrahydrofuran, 26.5 g of 1,3,5-tribenzoyl chloride, and 30.0 g of triethylamine under a nitrogen stream, and after passing 5°C cooling water through the flask jacket, gradually drop 13.0 g of hydroxyethyl methacrylate into the flask, and then keep it at room temperature for 2 hours. Then add 34.0 g of p-hydroxybiphenyl into the flask, continue to react for 12 hours, and filter to obtain a clear solution. Put the clear solution into water, obtain a precipitate with water, and dry it in a vacuum drying oven to obtain the compound shown in formula 10-1.

[0125] 2. Synthesis of the second acrylate monomer

[0126] After preparing a flask equipped with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 26.5 g of 1,3,5-tribenzoyl chloride, and 10.0 g of triethylamine were added under a nitrogen stream, and 5°C cooling water was passed through the flask jacket. Then 13.0 g of hydroxyethyl methacrylate was gradually added dropwise to the flask, and then kept at room temperature for 2 hours, filtered, and a clear solution was obtained. The clear solution was put into water, and after obtaining a precipitate with water, it was dried in a vacuum drying oven to obtain a compound represented by formula 11-1.

[0127] 3. Synthesis of the third acrylate monomer

[0128] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, add 240 g of tetrahydrofuran, 12.6 g of phloroglucinol, and 30.0 g of triethylamine under a nitrogen stream, pass 5°C cooling water through the flask jacket, and then gradually drop 10.4 g of methacryloyl chloride into the flask, and then keep it at room temperature for 2 hours. Then add 18.4 g of epichlorohydrin and heat to 100°C and stir for 1 hour. Filter to obtain a clear solution. Put the clear solution into water, use water to obtain a precipitate, and dry it in a vacuum drying oven to obtain the compound shown in formula 12-1.

[0129] 4. Synthesis of acrylic copolymer resin

[0130] 10.0 g of the compound represented by formula 10-1, 5.0 g of the compound represented by formula 11-1, 5.0 g of the compound represented by formula 12-1, 0.2 g of azobisisobutyl cyanide, and 80.0 g of solvent propylene glycol monomethyl ether acetate (PGMEA) were placed in a sandwich reactor, nitrogen was introduced to exclude oxygen, the temperature was raised to 65°C, and the reaction was carried out with stirring for 24 hours to obtain an acrylic copolymer resin solution.

[0131] 5. Preparation of negative photoresist composition

[0132] In a mixing tank equipped with an ultraviolet shielding film and a stirrer, 100 parts by mass of an acrylic copolymer resin (parts by mass calculated based on the mass of the acrylic copolymer resin in the acrylic copolymer resin solution), 50 parts by mass of trimethylolpropane triacrylate (product name: TMPTA, Nippon Kayaku Co., Ltd.), 40 parts by mass of dipentaerythritol pentaacrylate (product name: SR-399NS, Sartomer Co., Ltd.), 3 parts by mass of ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetoxime) (product name: OXE-02, BASF Co., Ltd.), 5 parts by mass of 4,4-bis-(diethylamino)-benzophenone (product name: Hycure EMK, KEMAX Co., Ltd.), 1 part by mass of γ-glycidoxypropyltrimethoxysilane, and 0.5 parts by mass of BYK-333 were added, and a solvent of propylene glycol monomethyl ether acetate was added while stirring to form a mixture. The amount of solvent was adjusted so that the viscosity of the mixture was 15 cPs. After the above components were uniformly mixed, they were filtered using a microporous filter with a pore size of 0.45 μm to prepare a negative photoresist composition, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition was 10.5%.

[0133] Example 2

[0134] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 5.0 g of the compound represented by Formula 10-1, 10.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0135] Example 3

[0136] 1. Synthesis of the first acrylate monomer

[0137] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 26.1 g of 1,3,5-isocyanatotriphenylene, and 0.1 g of dibutyltin dilaurate were added under a nitrogen stream, and the temperature of the flask was raised to 65°C. Then, 13.0 g of hydroxyethyl methacrylate was gradually added dropwise to the flask, and then the temperature was kept at 65°C for 2 hours. 34.0 g of p-hydroxybiphenyl was added to the flask, and the reaction was continued at 65°C for 12 hours to obtain a reaction solution. The reaction solution was put into water, and after obtaining a precipitate with water, it was dried in a vacuum drying oven to obtain a compound shown in Formula 10-2.

[0138] 2. Synthesis of the second acrylate monomer

[0139] After preparing a flask equipped with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 12.6 g of phloroglucinol, and 10.0 g of triethylamine were added under a nitrogen stream, 5°C cooling water was passed through the flask jacket, and 10.4 g of methacryloyl chloride was gradually added dropwise to the flask, and then kept at room temperature for 2 hours, filtered, and a clear solution was obtained. The clear solution was then put into water, precipitated with water, and dried in a vacuum drying oven to obtain the compound shown in Formula 11-2.

[0140] 3. Synthesis of the third acrylate monomer

[0141] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 12.6 g of phloroglucinol, and 0.1 g of dibutyltin dilaurate were added under a nitrogen stream, and the temperature of the flask was raised to 65°C. Then, 15.5 g of isocyanoethyl methacrylate was gradually added dropwise to the flask, and then the temperature was kept at 65°C for 2 hours, and then 18.4 g of epichlorohydrin was added and heated to 100°C and stirred for 1 hour to obtain a reaction solution. The reaction solution was put into water, and after obtaining a precipitate with water, it was dried in a vacuum drying oven to obtain a compound represented by formula 12-2.

[0142] 4. Synthesis of acrylic copolymer resin

[0143] 10.0 g of the compound represented by formula 10-2, 5.0 g of the compound represented by formula 11-2, 5.0 g of the compound represented by formula 12-2, 0.2 g of azobisisobutyl cyanide, and 80.0 g of solvent PGMEA were placed in a sandwich reactor, nitrogen was introduced to exclude oxygen, the temperature was raised to 65°C, and the reaction was carried out with stirring for 24 hours to obtain an acrylic copolymer resin solution.

[0144] 5. Preparation of negative photoresist composition

[0145] In a mixing tank equipped with an ultraviolet shielding film and a stirrer, 100 parts by mass of an acrylic copolymer resin (parts by mass calculated based on the mass of the acrylic copolymer resin in the acrylic copolymer resin solution), 50 parts by mass of trimethylolpropane triacrylate (product name: TMPTA, Nippon Kayaku Co., Ltd.), 40 parts by mass of dipentaerythritol pentaacrylate (product name: SR-399NS, Sartomer Co., Ltd.), 3 parts by mass of ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetoxime) (product name: OXE-02, BASF Co., Ltd.), 5 parts by mass of 4,4-bis-(diethylamino)-benzophenone (product name: Hycure EMK, KEMAX Co., Ltd.), 1 part by mass of γ-glycidoxypropyltrimethoxysilane, and 0.5 parts by mass of BYK-333 were added, and a solvent of propylene glycol monomethyl ether acetate was added while stirring to form a mixture. The amount of solvent was adjusted so that the viscosity of the mixture was 15 cPs. After the above components were uniformly mixed, they were filtered using a microporous filter with a pore size of 0.45 μm to prepare a negative photoresist composition, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition was 10.5%.

[0146] Example 4

[0147] The difference from Example 3 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 5.0 g of the compound shown in Formula 10-2, 10.0 g of the compound shown in Formula 11-2, and 5.0 g of the compound shown in Formula 12-2, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0148] Example 5

[0149] 1. Synthesis of the first acrylate monomer

[0150] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 12.6 g of phloroglucinol, and 0.1 g of dibutyltin dilaurate were added under a nitrogen flow, and the temperature of the reactor was raised to 65°C. 15.5 g of isocyanoethyl methacrylate was gradually added dropwise to the flask, and then kept at 65°C for 2 hours. Then 39.0 g of 4-biphenyl isocyanate was added to the reactor, and the reaction was continued at 65°C for 12 hours to obtain a reaction solution. The reaction solution was then put into water, precipitated with water, and dried in a vacuum drying oven to obtain a compound shown in Formula 10-3.

[0151] 2. Synthesis of the second acrylate monomer

[0152] After preparing a flask equipped with a mechanical stirrer, a thermometer, and a cooling jacket, 240 g of tetrahydrofuran, 12.6 g of phloroglucinol, and 0.1 g of dibutyltin dilaurate were added under a nitrogen flow, and the temperature of the flask was raised to 65°C. Then, 15.5 g of isocyanoethyl methacrylate was gradually added dropwise to the flask, and then kept at 65°C for 2 hours to obtain a reaction solution. After that, the reaction solution was put into water, and after obtaining a precipitate with water, it was dried in a vacuum drying oven to obtain a compound represented by formula 11-3.

[0153] 3. Synthesis of the third acrylate monomer

[0154] After preparing a flask with a mechanical stirrer, a thermometer, and a cooling jacket, add 240 g of tetrahydrofuran, 26.5 g of 1,3,5-tribenzoyl chloride, and 30.0 g of triethylamine under a nitrogen stream, and after passing 5°C cooling water through the flask jacket, gradually drop 13.0 g of hydroxyethyl methacrylate into the flask, and then keep it at room temperature for 2 hours. Then add 14.8 g of glycidol to the flask and stir the reaction at room temperature for 12 hours, filter, and obtain a clear solution. Then put the clear solution into water, obtain a precipitate with water, and dry it in a vacuum drying oven to obtain the compound shown in formula 12-3.

[0155] 4. Synthesis of acrylic copolymer resin

[0156] 10.0 g of the compound represented by formula 10-3, 5.0 g of the compound represented by formula 11-3, 5.0 g of the compound represented by formula 12-3, 0.2 g of azobisisobutyl cyanide, and 80.0 g of solvent PGMEA were placed in a sandwich reactor, nitrogen was introduced to exclude oxygen, the temperature was raised to 65°C, and the reaction was carried out with stirring for 24 hours to obtain an acrylic copolymer resin solution.

[0157] 5. Preparation of negative photoresist composition

[0158] In a mixing tank equipped with an ultraviolet shielding film and a stirrer, 100 parts by mass of an acrylic copolymer resin (parts by mass calculated based on the mass of the acrylic copolymer resin in the acrylic copolymer resin solution), 50 parts by mass of trimethylolpropane triacrylate (product name: TMPTA, Nippon Kayaku Co., Ltd.), 40 parts by mass of dipentaerythritol pentaacrylate (product name: SR-399NS, Sartomer Co., Ltd.), 3 parts by mass of ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetoxime) (product name: OXE-02, BASF Co., Ltd.), 5 parts by mass of 4,4-bis-(diethylamino)-benzophenone (product name: Hycure EMK, KEMAX Co., Ltd.), 1 part by mass of γ-glycidoxypropyltrimethoxysilane, and 0.5 parts by mass of BYK-333 were added, and a solvent of propylene glycol monomethyl ether acetate was added while stirring to form a mixture. The amount of solvent was adjusted so that the viscosity of the mixture was 15 cPs. After the above components were uniformly mixed, they were filtered using a microporous filter with a pore size of 0.45 μm to prepare a negative photoresist composition, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition was 10.5%.

[0159] Example 6

[0160] The difference from Example 5 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 5.0 g of the compound shown in Formula 10-3, 10.0 g of the compound shown in Formula 11-3, and 5.0 g of the compound shown in Formula 12-3, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0161] Example 7

[0162] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 30.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0163] Example 8

[0164] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 40.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0165] Example 9

[0166] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 2.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0167] Example 10

[0168] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 1.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0169] Embodiment 11

[0170] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 45.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0171] Example 12

[0172] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 60.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0173] Example 13

[0174] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 2.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0175] Embodiment 14

[0176] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 1.0 g of the compound represented by Formula 11-1, and 5.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0177] Embodiment 15

[0178] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 45.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0179] Example 16

[0180] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 60.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0181] Embodiment 17

[0182] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 2.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0183] Embodiment 18

[0184] The difference from Example 1 is that the added amounts of the first acrylate monomer, the second acrylate monomer, and the third acrylate monomer are changed to: 10.0 g of the compound represented by Formula 10-1, 5.0 g of the compound represented by Formula 11-1, and 1.0 g of the compound represented by Formula 12-1, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0185] Embodiment 19

[0186] The difference from Example 1 is that the mass fraction of trimethylolpropane triacrylate is changed to 150, the mass fraction of dipentaerythritol pentaacrylate is changed to 150, and other conditions remain the same, wherein the mass percentage of acrylic copolymer resin in the negative photoresist composition is 5%.

[0187] Embodiment 20

[0188] The difference from Example 1 is that the mass fraction of trimethylolpropane triacrylate is changed to 200, the mass fraction of dipentaerythritol pentaacrylate is changed to 200, and other conditions remain the same, wherein the mass percentage of acrylic copolymer resin in the negative photoresist composition is 4%.

[0189] Embodiment 21

[0190] The difference from Example 1 is that the synthesis process of the acrylic copolymer resin in step 4 is as follows:

[0191] 10.0 g of the compound represented by formula 10-1, 5.0 g of the compound represented by formula 11-1, 5.0 g of the compound represented by formula 12-1, 0.2 g of azobisisobutyl cyanide, and 80.0 g of solvent propylene glycol monomethyl ether acetate (PGMEA) were placed in a sandwich reactor, nitrogen was introduced to exclude oxygen, the temperature was raised to 65°C, and the reaction was stirred for 5 h to obtain an acrylic copolymer resin solution. Other conditions remained the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition was 10.5%.

[0192] Embodiment 22

[0193] The difference from Example 1 is that the synthesis process of the acrylic copolymer resin in step 4 is as follows:

[0194] 10.0 g of the compound represented by formula 10-1, 5.0 g of the compound represented by formula 11-1, 5.0 g of the compound represented by formula 12-1, 0.2 g of azobisisobutyl cyanide, and 80.0 g of solvent propylene glycol monomethyl ether acetate (PGMEA) were placed in a sandwich reactor, nitrogen was introduced to exclude oxygen, the temperature was raised to 65°C, and the reaction was stirred for 48 hours to obtain an acrylic copolymer resin solution. Other conditions remained the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition was 10.5%.

[0195] Comparative Example 1

[0196] The difference from Example 1 is that the first acrylate monomer is not added, 10.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0197] Comparative Example 2

[0198] The difference from Example 2 is that the first acrylate monomer is not added, 5.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0199] Comparative Example 3

[0200] The difference from Example 3 is that the first acrylate monomer is not added, 10.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0201] Comparative Example 4

[0202] The difference from Example 4 is that the first acrylate monomer is not added, 5.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0203] Comparative Example 5

[0204] The difference from Example 5 is that the first acrylate monomer is not added, 10.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0205] Comparative Example 6

[0206] The difference from Example 6 is that the first acrylate monomer is not added, 5.0 g of methyl methacrylate (MMA) is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0207] Comparative Example 7

[0208] The difference from Example 1 is that the first acrylate monomer is not added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0209] Comparative Example 8

[0210] The difference from Example 1 is that the second acrylate monomer is not added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0211] Comparative Example 9

[0212] The difference from Example 1 is that the third acrylate monomer is not added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 10.5%.

[0213] Comparative Example 10

[0214] The difference from Example 1 is that no acrylic monomer is added, and other conditions remain the same, wherein the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 20%.

[0215] The type and mass of the first acrylate monomer, the type and mass of the second acrylate monomer, the type and mass of the third acrylate monomer, the weight average molecular weight of the acrylic copolymer resin, and the type and mass of the acrylic monomer in each embodiment and comparative example are summarized in Table 1.

[0216] The performance of the prepared negative photoresist composition was tested by the following processes, and the results are shown in Table 2:

[0217] (1) Refractive index evaluation

[0218] After spin coating the negative photoresist composition on the silicon wafer substrate, the coated surface was heated and pre-dried (pre-dried at 100°C for 90 seconds), and after exposure without photomask, it was developed by tetramethylammonium hydroxide TMAH (2.38 wt%) aqueous solution at 25°C for 60 seconds, washed with pure water for 1 minute, and heated in an oven at 230°C for 30 minutes to form a cured product. The refractive index of the cured product was tested at a wavelength of 550nm using an ellipsometer.

[0219] Evaluation criteria: ◎: excellent, ●: good, ▲: fair, X: poor. According to the refractive index data, the evaluation is as follows: ◎: refractive index ≥ 1.60, ●: 1.55 ≤ refractive index < 1.60, ▲: 1.50 ≤ refractive index < 1.55, X: < 1.50.

[0220] (2) Transmittance evaluation

[0221] After spin coating the prepared negative photoresist composition on the glass substrate, the coated surface was heated and pre-dried (pre-dried at 100°C for 90 seconds), and after exposure without photomask, it was developed by tetramethylammonium hydroxide TMAH (2.38 wt%) aqueous solution at 25°C for 60 seconds, washed with pure water for 1 minute, and heated in an oven at 230°C for 30 minutes to form a cured product. The cured product was placed in a 150°C oven for heat aging for 240 hours, and the transmittance of the cured product was tested at a wavelength of 400 nm using a UV-visible spectrophotometer.

[0222] Evaluation criteria: ◎: Excellent, ●: Good, ▲: Fair, X: Poor. According to the transmittance data, the evaluation is as follows: ◎: >95%, ●: 90%≤ transmittance≤95%, ▲: 85%≤ transmittance<90%, X: <85%.

[0223] (3) Hardness evaluation

[0224] The curing process of the cured product is the same as the transmittance test. The hardness of the cured product is tested using a pencil hardness tester. The hardness test is performed by scratching with a standard pencil (Mitsubishi pencil: 1~6H, HB, 1~6B) at a load of 750g. The hardness is expressed based on the pencil without scratch marks. Hardness evaluation standard: The hardness increases in the order of 6B, 5B, 4B, 3B, 2B, B, HB, H, 2H, 3H, 4H, 5H, and 6H.

[0225] Evaluation criteria: ◎: Excellent, ●: Good, ▲: Fair, X: Poor. According to the hardness data, the evaluation is as follows: ◎: ≥3H, ●: 2H, ▲: H, X: ≤HB.

[0226] (4) Evaluation of substrate adhesion

[0227] The curing process of the cured product is the same as the transmittance test. The adhesion of the cured product to the substrate is tested by a cross-cut test. According to the ATSM-D3359 method, 100 checkerboard scales are formed on the cured product with a corner knife according to the checkerboard scale tape method, and then peeled with 3M's Scotch 600 tape, and the number of peeled checkerboard scales that have fallen off among the 100 peeled checkerboard scales is measured. According to the percentage of the number of peeled checkerboard scales that have fallen off to the 100 peeled checkerboard scales, the evaluation is as follows: 5B: no peeling (0%), 4B: peeling less than 5%, 3B: peeling 5%-15% (excluding 15%), 2B: peeling 15%-35% (excluding 35%), 1B: peeling 35%-65%, 0B: peeling>65%.

[0228] Evaluation criteria: ◎: Excellent (5B), ●: Good (4B), ▲: Fair (3B), X: Poor (<3B).

[0229] (5) Evaluation of development properties

[0230] After spin coating or slit coating the prepared negative photoresist composition on a transparent substrate, the coated surface is heated and pre-dried (pre-dried at 100°C for 90 seconds), and then exposed through a photomask with a 1-50μm pattern. After exposure, it is developed with tetramethylammonium hydroxide TMAH (2.38% mass fraction) aqueous solution at 25°C for 60 seconds, washed with pure water for 1 minute, and heated in an oven at 230°C for 30 minutes to form a pattern.

[0231] Evaluation criteria: ◎: Excellent, ●: Good, ▲: Fair, X: Poor. According to the pattern formation size, the evaluation is as follows: ◎: 1-5um, ●: 6-15um, ▲: 16-50um, X: > 50um cannot be developed.

[0232] (6) Weight average molecular weight test: The weight average molecular weight of the acrylic copolymer resin in the examples and comparative examples was tested using an Agilent liquid chromatography system (1260 infinityII, Agilent Technologies, Inc., USA). 0.1 g of the acrylic copolymer resin was placed in a 40 mL sample bottle, 4 g of tetrahydrofuran (THF) was added, and the mixture was shaken for 1 min to dissolve. The sample was then tested at a flow rate of 1 mL / min.

[0233] Table 1

[0234]

[0235]

[0236] Table 2

[0237]

[0238] As can be seen from Table 2, compared with Comparative Examples 1 to 10, the negative photoresist compositions in Examples 1 to 22 include a first initiator, an acrylic monomer, and an acrylic copolymer resin containing a first structural unit represented by Formula 1, a second structural unit represented by Formula 2, and a third structural unit represented by Formula 3. The negative photoresist composition has good anti-aging performance (i.e., its cured product still maintains a high transmittance after thermal aging at 150° C. for 240 hours), and has high refractive index, high transmittance, high adhesion and high hardness.

[0239] Specifically, compared with Comparative Examples 7 to 9, the negative photoresist composition in Example 1 includes a first initiator, an acrylic monomer, and an acrylic copolymer resin containing a first structural unit represented by Formula 1, a second structural unit represented by Formula 2, and a third structural unit represented by Formula 3. The negative photoresist composition has good anti-aging properties (i.e., its cured product still maintains a high transmittance after thermal aging at 150° C. for 240 hours), and has high refractive index, high transmittance, high adhesion and high hardness.

[0240] Compared with Comparative Examples 1 to 6, the acrylic copolymer resin in the negative photoresist composition in Examples 1 to 6 contains the first structural unit, which improves the anti-aging performance, refractive index, hardness, and adhesion of the negative photoresist composition. For example, compared with Comparative Example 1, the first acrylic ester monomer shown in Formula 10-1 is used in Example 1 to form the first structural unit, which improves the anti-aging performance, refractive index, hardness, and adhesion of the negative photoresist composition.

[0241] Compared with Example 20, Example 1 and Example 19 further control 0<a≤3, wherein a is the mass ratio of acrylic monomer to acrylic copolymer resin, so as to further improve the refractive index and hardness of the negative photoresist composition.

[0242] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A negative photoresist composition, characterized in that It includes an acrylic copolymer resin, an acrylic monomer and a first initiator; the acrylic copolymer resin includes a first structural unit, a second structural unit and a third structural unit; the first structural unit is shown in Formula 1: Formula 1, Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, and n1 is any integer from 0 to 10. Formula 1-1, Formula 1-2; The second structural unit is shown in Formula 2: Formula 2, Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, and n2 is any integer from 0 to 10. Formula 1-1, Formula 1-2; The structure of the third structural unit is shown in Formula 3: Formula 3; Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-2 and Formula 3-3, and n3 is any integer from 0 to 10. Formula 1-1, Formula 1-2, Formula 3-1, Formula 3-2, Formula 3-3.

2. The negative photoresist composition according to claim 1, characterized in that The first structural unit includes one or more of the structural units shown in Formula 4-1, Formula 4-2, and Formula 4-3: Formula 4-1, Formula 4-2 Formula 4-3; And / or, the second structural unit includes one or more of the structural units shown in Formula 5-1, Formula 5-2, and Formula 5-3: Formula 5-1, Formula 5-2 Formula 5-3; And / or, the third structural unit includes one or more of the structural units shown in Formula 6-1, Formula 6-2, and Formula 6-3: Formula 6-1, Formula 6-2 Formula 6-3; and / or, the weight average molecular weight of the acrylic copolymer resin is 500 g / mol to 100000 g / mol; And / or, the mass percentage of the acrylic copolymer resin in the negative photoresist composition is 5%-95%.

3. The negative photoresist composition according to claim 1, characterized in that: The acrylic copolymer resin is formed by copolymerizing monomer raw materials including a first acrylic ester monomer, a second acrylic ester monomer, and a third acrylic ester monomer; Preferably, the structure of the first acrylate monomer is as shown in Formula 7: Formula 7, Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 and R3 are each independently selected from any one of the groups shown in Formula 1-1 and Formula 1-2, and n1 is any integer from 0 to 10. Formula 1-1, Formula 1-2; Preferably, the structure of the second acrylate monomer is as shown in Formula 8: Formula 8, Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R4 is selected from any one of a carboxyl group and a hydroxyl group, and n2 is any integer from 0 to 10. Formula 1-1, Formula 1-2; Preferably, the structure of the third acrylate monomer is as shown in Formula 9: Formula 9, Wherein, R1 is selected from any one of a hydrogen atom and a methyl group, R2 is selected from any one of the groups shown in Formula 1-1 and Formula 1-2, R5 is selected from any one of the groups shown in Formula 3-1, Formula 3-2 and Formula 3-3, and n3 is any integer from 0 to 10. Formula 1-1, Formula 1-2, Formula 3-1, Formula 3-2, Formula 3-3; Preferably, the mass percentage of the first acrylate monomer in the monomer raw material is 5% to 95%; Preferably, the mass percentage of the second acrylate monomer in the monomer raw material is 5% to 95%; Preferably, the mass percentage of the third acrylate monomer in the monomer raw material is 5% to 95%.

4. The negative photoresist composition according to claim 3, characterized in that: The first acrylate monomer includes one or more compounds represented by Formula 10-1, Formula 10-2, and Formula 10-3: Formula 10-1, Formula 10-2, Formula 10-3; And / or, the second acrylate monomer includes one or more compounds represented by Formula 11-1, Formula 11-2, and Formula 11-3: Formula 11-1, Formula 11-2, Formula 11-3; And / or, the third acrylate monomer includes one or more compounds represented by Formula 12-1, Formula 12-2, and Formula 12-3: Formula 12-1, Formula 12-2, Formula 12-3.

5. The negative photoresist composition according to claim 1, characterized in that: The acrylic monomers include (meth)acrylate monomers containing at least two C=C groups; And / or, the negative photoresist composition satisfies: 0<a≤3, a is the mass ratio of the acrylic monomer to the acrylic copolymer resin, preferably 0.5≤a≤2, and more preferably 0.8≤a≤1.5; and / or, the first initiator comprises one or more of a photoinitiator, a thermal initiator, and a thermal acid generator; And / or, the negative photoresist composition satisfies: 0<b≤0.5, b is the mass ratio of the first initiator to the acrylic copolymer resin, preferably 0.01≤b≤0.1; And / or, the negative photoresist composition further comprises one or more of additives and solvents, wherein the additives comprise one or more of silane coupling agents and leveling agents; Preferably, the mass ratio of the additive to the acrylic copolymer resin is 0.001 to 0.1; Preferably, the solvent comprises propylene glycol monomethyl ether acetate.

6. The negative photoresist composition according to claim 5, characterized in that The (meth)acrylate monomer containing at least two C=C groups includes one or more of a (meth)acrylate monomer containing two C=C groups, a (meth)acrylate monomer containing three C=C groups, and a (meth)acrylate monomer containing more than three C=C groups; And / or, the photoinitiator includes one or more of O-acyl oxime compounds, acyloin compounds, acyloin ether compounds, acetophenone compounds, benzophenone compounds, quinone compounds, halogen compounds, and acylphosphine oxide compounds; and / or, the thermal initiator comprises one or more of peroxides and azo compounds; And / or, the thermal acid generator comprises a sulfonium salt.

7. A method for preparing a negative photoresist composition according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing a first initiator, an acrylic monomer and an acrylic copolymer resin to obtain the negative photoresist composition; Preferably, the process of mixing the first initiator, acrylic monomer and acrylic copolymer resin comprises: after mixing the first initiator, additives, acrylic monomer and acrylic copolymer resin, adding a solvent thereto to obtain the negative photoresist composition.

8. A structural member, characterized in that: A cured product comprising the negative photoresist composition according to any one of claims 1 to 6 or the negative photoresist composition prepared by the preparation method of the negative photoresist composition according to claim 7.

9. The structural member according to claim 8, characterized in that: The refractive index of the cured product is 1.55 to 1.65; And / or, the transmittance of the cured product after heat aging at 150±5° C. for 240±2 hours is greater than or equal to 95%.

10. A method for preparing a structural member according to any one of claims 8 to 9, characterized in that: The following steps are involved: Performing a molding process on the negative photoresist composition to obtain a molded product; The molded product is sequentially exposed and developed to obtain the structural component; wherein the developer includes alkaline solution.

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