Photo-thermal dual-curing organic silicon composition as well as preparation method and application thereof

Abstract

The invention discloses a photo-thermal dual-curing organic silicon composition as well as a preparation method and application thereof. Relates to the technical field of LED packaging. Raw materials of the photo-thermal dual-curing organic silicon composition comprise the following components: vinyl-terminated MT type hydroxyphenyl polysiloxane; linear vinyl terminated methyl phenyl polysiloxane; a linear hydrogen group terminated phenyl polysiloxane; a catalyst; the vinyl terminated MT type hydroxyl phenyl polysiloxane is phenyl polysiloxane containing silicon hydroxyl and silicon vinyl. The photo-thermal dual-curing organic silicon composition disclosed by the invention is an organic silicon composition which is good in mechanical strength, good in thixotropy, high in interface bonding force and resistant to high temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of LED packaging, and in particular to a photothermal dual-curing organic silicon composition, a preparation method thereof, and an application thereof. Background Art

[0002] Mini LED technology is an important development direction in the current display field. It improves the pixel density and display effect of the display panel by further reducing the size of the LED chip. Generally, the size of the Mini LED chip is between 50 and 200μm. Compared with traditional LED technology, its pixel density has been significantly improved, which makes Mini LED have higher brightness, more delicate display effects and wider application prospects. In the design of Mini LED backlight modules, double free-form surface lenses (microlenses) are often used to accurately control the light emitted by the chip, thereby optimizing the optical path between the backlight layer and the panel, improving the light efficiency and reducing the OD value, which is crucial to improving the display effect. The design and production method of microlenses is a key factor affecting the display effect of Mini LED. Therefore, how to effectively prepare microlenses with consistent shape and stable performance has become the focus of current technical research.

[0003] To simplify the process, the most common approach to forming microlenses is direct dispensing. This involves dispensing the material directly onto the LED chip surface to create the desired optical lens shape. During the dispensing process, the material needs to have a low viscosity to evenly flow over the LED chip surface and form the basic microlens shape. Once the external force is removed, the material must return to a higher viscosity to maintain the stability of the microlens. However, this method requires the material to possess excellent thixotropy, enabling shear thinning during the dispensing process to control the material's flow and shape. To achieve this, a thixotropic agent is often added to the encapsulant. Fumed silica is a common thixotropic agent. Its numerous surface hydroxyl groups form a three-dimensional, resilient hydrogen bond network, enhancing the encapsulant's thixotropy and improving its flow and formability. However, fumed silica also has some drawbacks in practical applications. First, fumed silica has poor dispersibility, making it difficult to evenly distribute within the material, which can affect the encapsulant's performance. In addition, over time, fumed silica can easily cause changes in the material structure, resulting in a decrease in the stability of the encapsulant and an increase in viscosity, which in turn affects the ease of operation and the molding effect of the microlens.

[0004] To overcome the problems associated with adding fumed silica, some researchers have developed liquid organosilicon thixotropic agents through hydrosilylation reactions. For example, CN103937257A and CN111718486A disclose the use of hydrogenated polysiloxanes reacted with olefinic modifiers (such as allyl glycidyl ether and butyl acrylate) to prepare liquid thixotropic agents. These liquid organosilicon thixotropic agents not only exhibit excellent thixotropy but also provide more stable performance during use. Furthermore, CN112979963A discloses a method for producing a reactive liquid organosilicon thixotropic agent by reacting a phenyl-containing cyclic hydrogenated polysiloxane or a branched hydrogenated polysiloxane with an unsaturated polyether. This thixotropic agent can further enhance the thixotropy of LED encapsulants and improve the molding effect of microlenses. However, because these thixotropic agents typically contain polar groups, they have poor compatibility with traditional packaging materials. In addition, the addition of thixotropic agents may lead to a decrease in aging resistance due to their structural characteristics, such as ether bonds, epoxy groups, etc.

[0005] In addition to the selection and application of thixotropic agents, the thermal curing process also has significant defects in the morphology control of Mini LED microlenses. First, due to the batch fluctuations of the mass production environment and the thermal curing materials, there are inevitably slight fluctuations in the temperature change of thermal curing and the curing rate of the material, resulting in inconsistent morphology of the microlens after thermal curing, which affects the optical properties of the chip, especially the luminous angle. In addition, Mini LED chips usually use flip-chip technology. There will be a gap between the two electrodes at the bottom of the chip. After the liquid glue is applied, the air in the bottom gap is covered by the liquid glue. Then, when the thermal curing temperature rises, the air escapes outward, destroying the shape of the microlens before the liquid glue cures, or causing bubbles in the cured lens. This will not only destroy the geometric integrity of the microlens, but also form light scattering defects inside the packaging glue, exacerbating the attenuation of optical performance. Therefore, there is an urgent need for a silicone thixotropic lens optical adhesive for specific Mini LED packaging, which has excellent lens morphology control and a solution to improve the bubble defects of the thermal curing process. Summary of the Invention

[0006] The object of the present invention is to provide a photothermally curable silicone composition with good mechanical strength, good thixotropy, high interfacial adhesion, high temperature resistance and optical transparency.

[0007] A first aspect of the present invention is:

[0008] Provided is a photothermal dual-curing silicone composition.

[0009] The second aspect of the present invention is:

[0010] Provided is a method for preparing a photothermal dual-curing organosilicon composition.

[0011] The third aspect of the present invention is:

[0012] Application of the photothermal dual-curing silicone composition.

[0013] Specifically, the technical solution adopted according to the first aspect of the present invention is:

[0014] A photothermal dual-curing organosilicon composition, wherein the raw materials of the photothermal dual-curing organosilicon composition include the following components:

[0015] Vinyl terminated MT type hydroxyphenyl polysiloxane;

[0016] Linear vinyl-terminated methylphenyl polysiloxane;

[0017] Linear hydrogen-terminated phenyl polysiloxane;

[0018] catalyst;

[0019] The vinyl-terminated MT-type hydroxyphenyl polysiloxane is a phenyl polysiloxane containing silanol groups and silanyl groups.

[0020] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0021] The photothermal dual-curing silicone composition of the present invention is an silicone composition with good mechanical strength, good thixotropy, high interfacial adhesion and high temperature resistance.

[0022] Specifically:

[0023] Vinyl-terminated MT-type hydroxyphenyl polysiloxane: As a resin matrix, its molecular structure contains both Si-Vi (silicyl vinyl) bonds and silanol groups. During the curing process, the Si-Vi bonds undergo a silylation reaction with the Si-H bonds in the linear hydrogen-terminated phenyl polysiloxane used as a crosslinker, while the silanol groups form a three-dimensional crosslinked network through a condensation reaction. This dual reaction mechanism gives the material excellent thermal stability and mechanical strength. Before curing, the silanol groups in the structure form a recoverable three-dimensional hydrogen bond network with fumed silica, ensuring the material's high thixotropy and enabling self-point molding.

[0024] Linear vinyl-terminated methylphenyl polysiloxane: This compound functions as both a toughening agent and a reactive diluent. The Si-Vi bonds in its linear molecular structure participate in a hydrosilylation reaction with the Si-H bonds in the crosslinking linear hydrogen-terminated phenyl polysiloxane. This linear structure improves the post-curing flexibility of the composition. Before curing, while maintaining the system's reactivity, it effectively reduces the composition's viscosity, improving dispensing performance.

[0025] Linear hydrogen-terminated phenyl polysiloxane: As a highly efficient crosslinking agent, it undergoes a silylation reaction through the Si-H bond in its molecular structure and the Si-Vi bond in the polysiloxane molecular structure, thereby causing the silicone encapsulation adhesive to cure during the LED encapsulation process.

[0026] According to one embodiment of the present invention, the raw materials of the light-thermal dual-cure silicone composition include the following components in parts by mass:

[0027] Vinyl-terminated MT-type hydroxyphenyl polysiloxane, 60-80 parts;

[0028] Linear vinyl-terminated methylphenyl polysiloxane, 2 to 10 parts;

[0029] Linear hydrogen-terminated phenyl polysiloxane, 18 to 33 parts.

[0030] According to one embodiment of the present invention, the molecular formula of the vinyl-terminated MT-type hydroxyphenyl polysiloxane is:

[0031] (MeSiO 3 / 2 ) x (PhSiO 3 / 2 ) y (R 1 2SiO) z (R 2 2SiO 1 / 2 ) m , formula (1);

[0032] R 1 are independently selected from one of methyl, phenyl, alkoxy and hydroxyl groups, and the number of hydroxyl groups is not 0; x, y, z and m are values greater than 0; R 2 The vinyl-terminated MT-type hydroxyphenyl polysiloxane has a phenyl group mass fraction of 8% to 32%.

[0033] According to one embodiment of the present invention, the molecular formula of the linear vinyl-terminated methylphenyl polysiloxane is:

[0034] (Me2SiO) x (Ph2SiO) y (R2ViSiO 1 / 2 )2, formula (2);

[0035] In formula (2), R2 is independently selected from methyl or phenyl; x and y are values greater than 0, and the mass fraction of the phenyl group in the linear vinyl-terminated methylphenyl polysiloxane is 8% to 32%.

[0036] According to one embodiment of the present invention, the molecular formula of the linear hydrogen-terminated phenyl polysiloxane is:

[0037] (MePhSiO) x (MeHSiO) y (Me2SiO) z (R 3 2HSiO 1 / 2 )2, formula (3);

[0038] In formula (3), R 3 are independently selected from methyl or phenyl; x, y, and z are values greater than 0, and the mass fraction of the phenyl group in the linear hydrogen-terminated phenyl polysiloxane is 8% to 32%.

[0039] According to one embodiment of the present invention, the light-heat dual-curing silicone composition, the raw materials include the following components in parts by mass:

[0040] Vinyl-terminated MT-type hydroxyphenyl polysiloxane, 60-74 parts;

[0041] Linear vinyl-terminated methylphenyl polysiloxane, 2 to 10 parts;

[0042] Linear hydrogen-terminated phenyl polysiloxane, 18 to 33 parts.

[0043] According to one embodiment of the present invention, the light-heat dual-curing silicone composition, the raw materials include the following components in parts by mass:

[0044] Vinyl-terminated MT-type hydroxyphenyl polysiloxane, 60-80 parts;

[0045] Linear vinyl-terminated methylphenyl polysiloxane, 2-5 parts;

[0046] Linear hydrogen-terminated phenyl polysiloxane, 18 to 33 parts.

[0047] According to one embodiment of the present invention, the light-heat dual-curing silicone composition, the raw materials include the following components in parts by mass:

[0048] Vinyl-terminated MT-type hydroxyphenyl polysiloxane, 60-80 parts;

[0049] Linear vinyl-terminated methylphenyl polysiloxane, 2 to 10 parts;

[0050] Linear hydrogen-terminated phenyl polysiloxane, 18 to 21 parts.

[0051] According to one embodiment of the present invention, the raw materials of the photothermal dual-cure silicone composition also include a filler selected from fumed silica or precipitated silica. Preferably, the filler is fumed silica, and more preferably, the filler is hydrophobic fumed silica. The silanol groups in the vinyl-terminated MT-type hydroxyphenyl polysiloxane of the present invention can form an effective three-dimensional hydrogen bond network with the fumed silica, thereby improving the material's thixotropy.

[0052] According to one embodiment of the present invention, the phenyl mass fraction of the phenyl polysiloxane in the photothermal dual-curing silicone composition is 8% to 32%. The phenyl mass fraction of the phenyl polysiloxane in the photothermal dual-curing silicone composition needs to match the filler selection to ensure that the photothermal dual-curing silicone composition is optically transparent after curing.

[0053] According to one embodiment of the present invention, the particle size of the filler can be selected as needed. Preferably, the particle size of the filler is 1 nm to 500 nm, which is conducive to improving the optical properties of the optical-thermal dual-cure silicone composition. More preferably, the particle size of the filler is 1 to 200 nm.

[0054] According to one embodiment of the present invention, the specific surface area of the filler is not particularly limited, and the specific surface area of the filler can be selected as needed. Preferably, the BET specific surface area of the filler is 100 m 2 / g to 800m 2 / g, so as to improve the thixotropic properties of the light-heat dual-curing silicone composition; more preferably, the BET specific surface area of the filler is 150 m 2 / g to 600m 2 / g.

[0055] According to one embodiment of the present invention, the mass of the filler is 3% to 10% of the total mass of the vinyl-terminated MT-type hydroxyphenyl polysiloxane, the linear vinyl-terminated methylphenyl polysiloxane and the linear hydrogen-terminated phenyl polysiloxane.

[0056] According to one embodiment of the present invention, the raw material components of the photothermal dual-curing silicone composition further include a tackifying agent, and the molecular formula of the tackifying agent is:

[0057] The adhesion promoter is used in the light-heat dual-cure silicone composition to improve the adhesion performance.

[0058] According to one embodiment of the present invention, the mass of the adhesion promoter is 1% to 5% of the total mass of the vinyl-terminated MT-type hydroxyphenyl polysiloxane, the linear vinyl-terminated methylphenyl polysiloxane and the linear hydrogen-terminated phenyl polysiloxane.

[0059] According to one embodiment of the present invention, the catalyst includes a photothermal curing platinum catalyst and a condensation catalyst.

[0060] According to one embodiment of the present invention, the catalyst comprises a photothermal curing platinum catalyst. The photothermal curing platinum catalyst is used in the photothermal dual-cure silicone composition to promote the smooth hydrosilylation reaction between the Si-Vi bond in the organopolysiloxane molecular structure and the Si-H bond in the linear hydrogen-terminated phenyl polysiloxane structure as a crosslinker under conditions of light and heat.

[0061] According to one embodiment of the present invention, the photothermal curing platinum catalyst is a cyclopentadiene complex of platinum.

[0062] According to one embodiment of the present invention, the photothermal curing platinum catalyst is selected from at least one of trimethyl[(trimethoxysilyl)methylcyclopentadienyl]platinum(IV), trimethyl[(2-trimethoxysilyl)ethylcyclopentadienyl]platinum(IV), trimethyl[(triethoxysilyl)methylcyclopentadienyl]platinum(IV), trimethyl[(tripropoxysilyl)methylcyclopentadienyl]platinum(IV), triethyl[(trimethoxysilyl)methylcyclopentadienyl]platinum(IV), tripropyl[(trimethoxysilyl)methylcyclopentadienyl]platinum(IV), trimethyl[(methyldimethoxysilyl)propylcyclopentadienyl]platinum(IV) and (trimethyl)methylcyclopentadienylplatinum(IV).

[0063] According to one embodiment of the present invention, the catalyst comprises a condensation catalyst. The condensation catalyst is used in the photothermal dual-cure silicone composition to promote the condensation of silanol groups in the vinyl-terminated MT-type hydroxyphenyl polysiloxane structure under heating, thereby increasing the crosslink density and shear force of the cured material. Furthermore, because the condensation catalyst promotes chemical bonding reactions between silanol groups, it also improves the mechanical strength of the photothermal dual-cure silicone composition while reducing residual silanol groups, ensuring the material's high-temperature resistance.

[0064] According to one embodiment of the present invention, the condensation catalyst is selected from an organic titanium compound or an organic zirconium compound.

[0065] According to one embodiment of the present invention, the condensation catalyst is selected from zirconium n-propoxide or tetrabutyl titanate.

[0066] According to one embodiment of the present invention, the mass of the condensation catalyst is 0.01% to 1% of the total mass of the vinyl-terminated MT-type hydroxyphenyl polysiloxane, the linear vinyl-terminated methylphenyl polysiloxane and the linear hydrogen-terminated phenyl polysiloxane.

[0067] Specifically, the technical solution adopted according to the second aspect of the present invention is:

[0068] A method for preparing the photothermal dual-curing silicone composition comprises the following steps:

[0069] The photothermal dual-curing silicone composition is obtained by mixing vinyl-terminated MT-type hydroxyphenyl polysiloxane, linear vinyl-terminated methylphenyl polysiloxane, linear hydrogen-terminated phenyl polysiloxane and a catalyst under light-proof conditions.

[0070] According to one embodiment of the present invention, the method for preparing the photothermal dual-cure silicone composition comprises the following steps: vinyl-terminated MT-type hydroxyphenyl polysiloxane, linear vinyl-terminated methylphenyl polysiloxane, linear hydrogen-terminated phenyl polysiloxane, and a catalyst are divided into two components and mixed separately in a mixing device to prepare the photothermal dual-cure silicone composition in a two-component form. When in use, the two components are then combined to achieve curing.

[0071] A method for preparing the vinyl-terminated MT-type hydroxyphenyl polysiloxane comprises the following steps:

[0072] S1: Divinyltetramethylsiloxane, hexamethyldisiloxane, water and an acid catalyst are mixed in a reaction vessel;

[0073] S2, under stirring conditions, controlling the temperature not to exceed 40° C., adding at least one trimethoxysilane dropwise to the reaction vessel, heating the reaction mixture to 65-70° C., and reacting for 1.5-2.5 hours to obtain a mixture; the trimethoxysilane is selected from at least one of phenyltrimethoxysilane and methyltrimethoxysilane;

[0074] S3: adding cyclohexane to the mixture, raising the temperature to reflux, performing water separation and continuously adding water, the total reaction time is 3 to 26 hours;

[0075] S4: Cool the reaction solution to room temperature, add a neutralizer to neutralize the acid catalyst, and then wash to a pH of 6-7;

[0076] S5 removes the solvent to obtain the vinyl-terminated MT-type hydroxyphenyl polysiloxane.

[0077] According to one embodiment of the present invention, the acid catalyst comprises trifluoromethanesulfonic acid.

[0078] According to one embodiment of the present invention, the temperature raised to the reflux state is a temperature at which the material can generate reflux.

[0079] A method for preparing linear vinyl-terminated methylphenyl polysiloxane comprises the following steps:

[0080] A1: divinyltetramethyldisiloxane, diphenyldimethoxysilane, and dimethyldimethoxysilane are mixed at room temperature, stirred, and then toluene and trifluoromethanesulfonic acid are added. Subsequently, water is added dropwise with stirring to obtain a mixture;

[0081] A2: The mixture is heated to 65°C for reaction for 5 hours, cooled and washed until neutral, the water layer is removed, trifluoromethanesulfonic acid is added, the temperature is raised to 65°C for reaction for more than 5 hours, the reaction is stopped, the temperature is cooled and washed until neutral, and the linear vinyl-terminated methylphenyl polysiloxane is obtained by vacuum desolvation.

[0082] A method for preparing the linear hydrogen-terminated phenyl polysiloxane comprises the following steps:

[0083] B1: Mix a hydrogen-containing end-capping agent, a phenyl-containing siloxane monomer, a cyclic siloxane monomer, a linear siloxane monomer, and an organic solvent, add a first strong acid catalyst, stir and mix until uniform, add water, react at 60-70°C for 4-6 hours, cool after the reaction, wash until neutral, and separate to obtain an organic layer;

[0084] B2: adding a second strong acid catalyst to the organic layer, continuing the reaction at 60-70° C. for 4-6 hours, washing the reaction solution to neutrality, removing the organic solvent, and obtaining a linear hydrogen-terminated phenyl polysiloxane.

[0085] According to one embodiment of the present invention, the hydrogen-containing capping agent is tetramethyldisiloxane.

[0086] According to one embodiment of the present invention, the phenyl-containing siloxane monomer is methylphenyldimethoxysilane.

[0087] According to one embodiment of the present invention, the cyclic siloxane monomer is tetramethylcyclotetrasiloxane, and the linear siloxane monomer is dimethyldimethoxysilane.

[0088] According to one embodiment of the present invention, the first strong acid catalyst and the second strong acid catalyst are trifluoromethanesulfonic acid.

[0089] According to one embodiment of the present invention, the reaction temperature in step B1 and step B2 is both 65° C., and the reaction time is both 5 hours.

[0090] According to one embodiment of the present invention, the organic solvent is toluene.

[0091] According to the embodiments of the present invention, the technical solution of the present invention has at least one of the following advantages or beneficial effects:

[0092] In order to solve the defects of the prior art, the present invention synthesizes MT-type phenyl polysiloxane with silanol groups, utilizes silanol groups and fumed silica to form a recoverable three-dimensional hydrogen bond network, thereby improving the thixotropy of the material composition. The silanol groups in the structure can also improve the interfacial adhesion between the material and the substrate after curing. Photothermal curing platinum catalyst and condensation catalyst are used to prepare highly thixotropic and highly transparent photothermal curing phenyl polysiloxane. Photocuring at room temperature is used to reduce the morphological changes caused by the escape of bubbles due to heat in the initial curing stage, and then thermal curing is used for deep curing. In this way, the defects of single thermal curing are solved by combining photothermal curing. The use of condensation catalysts can promote chemical bonding reactions between silanol groups, improve the mechanical strength of the material while reducing the residual silanol groups, and ensure the high temperature resistance of the material. Thus, a photothermal curing silicone composition with good mechanical strength, good thixotropy, high interfacial adhesion, high temperature resistance and optical transparency is provided.

[0093] Another aspect of the present invention provides a microlens for a Mini LED. This microlens comprises the optical-thermal dual-cure silicone composition described in the first embodiment. Because this application utilizes all of the technical solutions of the optical-thermal dual-cure silicone composition, it possesses at least all of the beneficial effects of the technical solutions of the aforementioned embodiment.

[0094] The method for preparing the microlens in the Mini LED includes the following steps: dispensing the photothermal dual-curing silicone composition on the surface of the LED chip, and sequentially curing it by light radiation and heat to obtain the microlens.

[0095] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0096] On the premise that the photothermal dual-curing silicone composition described in the present invention has good thixotropy, high interfacial adhesion and high temperature resistance, the present invention reduces the change in morphology in the initial curing stage by photocuring at room temperature, and then uses thermal curing for deep curing. The combination of photocuring and heating deep curing enables the present invention to solve the morphological inconsistency caused by single thermal curing of the automatically formed silicone material in the preparation process of Mini LED microlenses.

[0097] According to one embodiment of the present invention, the light radiation curing is performed by irradiation curing with a UV-LED lamp.

[0098] According to one embodiment of the present invention, the wavelength of light for the photo-radiation curing is about 365 nm.

[0099] According to one embodiment of the present invention, the light radiation energy of the light radiation curing is 300mJ / cm 2 about.

[0100] According to one embodiment of the present invention, the temperature of the thermal curing is 150-200° C. Preferably, the temperature of the thermal curing is 150° C.

[0101] According to one embodiment of the present invention, the baking time of the thermal curing is 3-4 hours. Preferably, the baking time of the thermal curing is 3 hours.

[0102] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0103] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0104] Figure 1 This is the H NMR spectrum of vinyl-terminated MT-type hydroxyphenyl polysiloxane A-1.

[0105] Figure 2 This is the H-NMR spectrum of vinyl-terminated MT-type hydroxyphenyl polysiloxane A-2.

[0106] Figure 3 This is the H NMR spectrum of vinyl-terminated MT-type phenyl polysiloxane A-3.

[0107] Figure 4 This is the H NMR spectrum of vinyl-terminated MT-type phenyl polysiloxane A-4.

[0108] Figure 5 This is the H NMR spectrum of MT-type hydroxyphenyl polysiloxane A-5. DETAILED DESCRIPTION

[0109] The terms "preferred," "more preferred," and the like, used herein refer to embodiments of the present invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the present invention.

[0110] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges subsumed therein.

[0111] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of the present invention.

[0112] The raw materials used in the embodiment are as follows:

[0113] The hydrophobic fumed silica D of the present invention is purchased from Deshan DM 30.

[0114] The vinyl-terminated MT-type hydroxyphenyl polysiloxane of the present invention is synthesized by the following different steps to obtain phenyl polysiloxane products with different structures, which are named A-1, A-2, A-3 and A-4 respectively;

[0115] Among them, A-1 and A-2 are medium refractive index vinyl-terminated MT-type hydroxyphenyl polysiloxane products;

[0116] Among them, A-3 is a medium refractive index vinyl-terminated MT-type phenyl polysiloxane product;

[0117] Wherein, A-4 is a vinyl-terminated MT-type phenyl polysiloxane with a high refractive index;

[0118] Among them, A-5 is a medium refractive index MT type hydroxyphenyl polysiloxane product.

[0119] Among them, A-1 H NMR spectrum is as follows Figure 1 , whose molecular formula is:

[0120] (MeSiO 3 / 2 ) x (PhSiO 3 / 2 ) y (R 1 (OH)SiO) z (R 2 R 3 2SiO1 / 2) m (Me2ViSiO 1 / 2 ) 0.91 (Me3SiO 1 / 2 ) 0.16 ;

[0121] Where x+y+z+m=4.13; R 1 R is independently methyl or phenyl; 2 R is independently methyl or phenyl; 3 are each independently hydroxy or methoxy.

[0122] Among them, A-2 H NMR spectrum is as follows Figure 2 , whose molecular formula is:

[0123] (MeSiO 3 / 2 ) x (PhSiO 3 / 2 ) y (R 1 (OH)SiO) z (R 2 R 3 2SiO1 / 2) m (Me2ViSiO 1 / 2 ) 0.91 (Me3SiO 1 / 2 ) 0.16 ;

[0124] Where x+y+z+m=4.13; R 1 R is independently methyl or phenyl; 2 R is independently methyl or phenyl; 3 are each independently hydroxy or methoxy.

[0125] Among them, A-3 H NMR spectrum is as follows Figure 3 The molecular formula is:

[0126] (MeSiO 3 / 2 ) 3.41 (PhSiO 3 / 2 ) 0.71 (MeViSiO 1 / 2 ) 0.91 (Me2SiO 1 / 2 ) 0.16 .

[0127] Among them, A-4 H NMR spectrum is as follows Figure 4 , whose molecular formula is:

[0128] (PhSiO 3 / 2 ) 4.13 (MeViSiO 1 / 2 ) 0.91 (Me2SiO 1 / 2 ) 0.16 .

[0129] The preparation method of A-1 comprises the following steps:

[0130] At room temperature, 85 g of divinyltetramethylsiloxane, 13 g of hexamethyldisiloxane, 350 g of distilled water, and 0.15 g of trifluoromethanesulfonic acid were added to the reaction flask; the speed was set to 150 r / min, and a mixture of 141 g of phenyltrimethoxysilane and 465 g of methyltrimethoxysilane was added dropwise to the reaction flask using a constant pressure dropping funnel. The rate of addition was such that the material temperature did not exceed 40 ° C. After the addition was completed, the material temperature was raised to 68 ° C and reacted for 2 h;

[0131] Add 420g of cyclohexane, increase the oil temperature until the material refluxes, and use a water separator to drain the alcohol water. At the same time, add pure water of the same mass as the drained pure water. Maintain the above operation for 26h. After the reaction is completed, cool to room temperature and add 0.13g of NaHCO3. Stir for 30min and let it stand. Stop stirring, remove the water layer, and repeat washing with pure water until the pH value is 6-7.

[0132] Set the stirring speed to 150 r / min, turn on the vacuum pump to evacuate, increase the temperature to remove the solvent, and continue evacuating for 1 hour after no large amount of distillate flows out and no obvious bubbles are found. Then stop heating and vacuuming, and the material is a colorless viscous liquid A-1 with a viscosity of 110,000 mPa.S, a vinyl content of 5.43 wt%, a refractive index of 1.4550, a phenyl content of 13.1 wt%, and a hydroxyl content of 5.4 wt%.

[0133] The preparation method of A-2 comprises the following steps:

[0134] Add 85 g of divinyltetramethylsiloxane, 13 g of hexamethyldisiloxane, 350 g of distilled water, and 0.15 g of trifluoromethanesulfonic acid into the reaction flask at room temperature;

[0135] Set the speed to 150r / min, and add the mixture of 141g of phenyltrimethoxysilane and 465g of methyltrimethoxysilane into the reaction flask using a constant pressure dropping funnel. The rate of addition should be such that the material temperature does not exceed 40°C. After the addition is completed, raise the material temperature to 68°C and react for 2h.

[0136] Add 420g of cyclohexane, increase the oil temperature until the material refluxes, and use a water separator to drain the alcohol water. At the same time, add pure water of the same mass as the drained pure water. Keep the above operation for 3h. After the reaction is completed, cool to room temperature and add 0.13g of NaHCO3. Stir for 30min and let it stand. Stop stirring, remove the water layer, and repeat washing with pure water until the pH value is 6-7.

[0137] Set the stirring speed to 150 r / min, turn on the vacuum pump to evacuate, increase the temperature to remove the solvent, and continue evacuating for 1 hour after no large amount of distillate flows out and no obvious bubbles are found. Then stop heating and vacuuming, and the material is a colorless viscous liquid A-2 with a viscosity of 40,000 mPa.S, a vinyl content of 5.49 wt%, a refractive index of 1.4520, a phenyl content of 13.1 wt%, and a hydroxyl content of 4.5 wt%.

[0138] The preparation method of A-3 comprises the following steps:

[0139] Add 85 g of divinyltetramethylsiloxane, 13 g of hexamethyldisiloxane, 350 g of distilled water, and 0.15 g of trifluoromethanesulfonic acid into the reaction flask at room temperature;

[0140] Set the speed to 150r / min, and add the mixture of 141g of phenyltrimethoxysilane and 465g of methyltrimethoxysilane into the reaction flask using a constant pressure dropping funnel. The rate of addition should be such that the material temperature does not exceed 40°C. After the addition is completed, raise the material temperature to 68°C and react for 2h.

[0141] Add 420g of cyclohexane, increase the oil temperature until the material refluxes, and use a water separator to discharge the alcohol water. At the same time, add pure water of the same mass as the discharged pure water, and maintain the above operation for 3h. After the reaction is completed, cool to room temperature, stop stirring, remove the lower layer of water, heat and reflux to remove the residual water in the oil phase, then add 0.25g of trifluoromethanesulfonic acid, react for 6h, cool to room temperature, and add 0.13g of NaHCO3, stir for 30min and let stand; stop stirring, remove the water layer, and then repeatedly wash with pure water to a pH value of 6-7;

[0142] Set the stirring speed to 150 r / min, turn on the vacuum pump to evacuate, increase the temperature to remove the solvent, and continue evacuating for 1 hour after no large amount of distillate flows out and no obvious bubbles are found. Then stop heating and vacuuming. At room temperature, the product is a colorless solid A-3 with a vinyl content of 5.3 wt%, a refractive index of 1.4620, and a phenyl content of 13.1 wt%.

[0143] The preparation method of A-4 comprises the following steps:

[0144] Add 85 g of divinyltetramethylsiloxane, 13 g of hexamethyldisiloxane, 350 g of distilled water, and 0.15 g of trifluoromethanesulfonic acid into the reaction flask at room temperature;

[0145] Set the speed to 150r / min and add 818g of phenyltrimethoxysilane dropwise into the reaction flask using a constant pressure dropping funnel. The rate of addition should be such that the material temperature does not exceed 40°C. After the addition is complete, raise the material temperature to 68°C and react for 2h.

[0146] Add 420g of cyclohexane, increase the oil temperature until the material refluxes, and use a water separator to discharge the alcohol water. At the same time, add pure water of the same mass as the discharged pure water, and maintain the above operation for 3h. After the reaction is completed, cool to room temperature, stop stirring, remove the lower layer of water, heat and reflux to remove the residual water in the oil phase, then add 0.25g of trifluoromethanesulfonic acid, react for 6h, cool to room temperature, and add 0.13g of NaHCO3, stir for 30min and let stand; stop stirring, remove the water layer, and then repeatedly wash with pure water to a pH value of 6-7;

[0147] Set the stirring speed to 150 r / min, turn on the vacuum pump to evacuate, increase the temperature to remove the solvent, and continue evacuating for 1 hour after no large amount of distillate flows out and no obvious bubbles are found. Then stop heating and vacuuming. At room temperature, the product is a colorless solid A-4 with a vinyl content of 3.5 wt%, a refractive index of 1.5410, and a phenyl content of 50 wt%.

[0148] The H NMR spectrum of A-5 is as follows Figure 5 , the preparation method of A-5 comprises the following steps:

[0149] At room temperature, 87 g of hexamethyldisiloxane, 350 g of distilled water, and 0.15 g of trifluoromethanesulfonic acid were added to the reaction flask; the speed was set to 150 r / min, and a mixture of 141 g of phenyltrimethoxysilane and 465 g of methyltrimethoxysilane was added dropwise to the reaction flask using a constant pressure dropping funnel. The rate of addition was such that the material temperature did not exceed 40°C. After the addition was completed, the material temperature was raised to 68°C and reacted for 2 h;

[0150] Add 420g of cyclohexane, increase the oil temperature until the material refluxes, and use a water separator to drain the alcohol water. At the same time, add pure water of the same mass as the drained pure water. Maintain the above operation for 26h. After the reaction is completed, cool to room temperature and add 0.13g of NaHCO3. Stir for 30min and let it stand. Stop stirring, remove the water layer, and repeat washing with pure water until the pH value is 6-7.

[0151] Set the stirring speed to 150 r / min, turn on the vacuum pump to evacuate, increase the temperature to remove the solvent, and continue evacuating for 1 hour after no large amount of distillate flows out and no obvious bubbles are found. Then stop heating and vacuuming, and the material is a colorless viscous liquid A-1 with a viscosity of 120,000 mPa.S, a refractive index of 1.4630, a phenyl content of 13.4 wt%, and a hydroxyl content of 5.4 wt%.

[0152] The molecular formula of the linear vinyl-terminated methylphenyl polysiloxane of the present invention is:

[0153] (Me2SiO) 97.5 (Ph2SiO) 15 (MeViSiO 1 / 2 )2.

[0154] The preparation method of the linear vinyl-terminated methylphenyl polysiloxane B comprises the following steps:

[0155] In a three-necked flask, 1.86 g of divinyltetramethyldisiloxane, 36.6 g of diphenyldimethoxysilane, and 117 g of dimethyldimethoxysilane were added at room temperature. After rapid stirring for 10 min, 300 g of toluene and 0.155 g of trifluoromethanesulfonic acid were added, and stirring was continued for 30 min. Subsequently, 55 g of water was added dropwise under stirring, and the temperature was raised to 65 ° C. and reacted for 5 h. After cooling and washing to neutrality, the water layer was removed, 0.155 g of trifluoromethanesulfonic acid was added, and the temperature was raised to 65 ° C. and reacted for more than 5 h. The reaction stopped, the material returned to room temperature and washed with water to neutrality, and heated and vacuumed to obtain a colorless viscous liquid linear vinyl-terminated methylphenyl polysiloxane B with a viscosity of 2000 cPs, a vinyl content of 0.49 wt%, and a refractive index of 1.4610.

[0156] The linear hydrogen-terminated phenyl polysiloxane of the present invention is synthesized through the following three different steps to obtain linear hydrogen-terminated phenyl polysiloxane products with different hydrogen contents, which are named C-1, C-2, and C-3 respectively.

[0157] Among them, the molecular formula of C-1 is: (MePhSiO) 30 (MeHSiO) 60 (Me2SiO) 30 (R2HSiO 1 / 2 )2.

[0158] Among them, the molecular formula of C-2 is: (MePhSiO) 30 (MeHSiO) 30 (Me2SiO) 54 (R2HSiO 1 / 2 )2.

[0159] Among them, the molecular formula of C-3 is: (MePhSiO) 30 (MeHSiO) 75 (Me2SiO) 15 (R2HSiO 1 / 2 )2.

[0160] The preparation method of C-1 comprises the following steps:

[0161] In a three-necked flask, 1.34 g of tetramethyldisiloxane, 54.6 g of methylphenyldimethoxysilane, 36 g of tetramethylcyclotetrasiloxane, and 36 g of dimethyldimethoxysilane were added at room temperature. After rapid stirring for 10 min, 300 g of toluene and 0.155 g of trifluoromethanesulfonic acid were added. Stirring was continued for 30 min, and then 42 g of water was added dropwise under stirring. After the addition was complete, the temperature was raised to 65 ° C and the reaction was carried out for 5 h. After cooling and washing until neutral, the water layer was removed;

[0162] Add 0.155 g of trifluoromethanesulfonic acid, raise the temperature to 65 ° C and react for more than 5 hours. After the reaction stops, the material is returned to room temperature and washed with water until neutral. Heat and vacuum desolventize to obtain a colorless viscous liquid C-1 with a viscosity of 50 cPs, a hydrogen content of 0.71 wt%, and a refractive index of 1.4630.

[0163] The preparation method of C-2 comprises the following steps:

[0164] In a three-necked flask, 1.34 g of tetramethyldisiloxane, 54.6 g of methylphenyldimethoxysilane, 18 g of tetramethylcyclotetrasiloxane, and 65 g of dimethyldimethoxysilane were added at room temperature. After rapid stirring for 10 min, 300 g of toluene and 0.155 g of trifluoromethanesulfonic acid were added. Stirring was continued for 30 min, and then 42 g of water was added dropwise under stirring. After the addition was complete, the temperature was raised to 65 ° C and the reaction was carried out for 5 h. After cooling and washing until neutral, the water layer was removed;

[0165] Add 0.155 g of trifluoromethanesulfonic acid, raise the temperature to 65 ° C and react for more than 5 hours. After the reaction is stopped, the material is returned to room temperature and washed with water until neutral. Heat and vacuum desolventize to obtain a colorless viscous liquid C-2 with a viscosity of 40 cPs, a hydrogen content of 0.40 wt%, and a refractive index of 1.4610.

[0166] The preparation method of C-3 comprises the following steps:

[0167] In a three-necked flask, 1.34 g of tetramethyldisiloxane, 54.6 g of methylphenyldimethoxysilane, 45 g of tetramethylcyclotetrasiloxane, and 18 g of dimethyldimethoxysilane were added at room temperature. After rapid stirring for 10 min, 300 g of toluene and 0.155 g of trifluoromethanesulfonic acid were added. Stirring was continued for 30 min, and then 42 g of water was added dropwise under stirring. After the addition was complete, the temperature was raised to 65 ° C and the reaction was carried out for 5 h. After cooling and washing until neutral, the water layer was removed;

[0168] Add 0.155 g of trifluoromethanesulfonic acid, raise the temperature to 65 ° C and react for more than 5 hours. After the reaction stops, return the material to room temperature and wash with water until neutral. Heat and vacuum desolventize to obtain a colorless viscous liquid C-3 with a viscosity of 40 cPs, a hydrogen content of 0.80 wt%, and a refractive index of 1.4610.

[0169] The platinum catalyst of the present invention is selected from a thermal platinum catalyst and a photothermal curing platinum catalyst, wherein the photothermal curing platinum catalyst is (trimethyl)methylcyclopentadiene platinum (IV), and the thermal platinum catalyst is a platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum content is 0.5wt%).

[0170] The condensation catalyst of the present invention is selected from zirconium n-propoxide.

[0171] The above-mentioned tackifying aid of the present invention is an existing tackifying aid, and its preparation method comprises the following steps:

[0172] In a 500 mL three-necked flask equipped with a constant pressure dropping funnel, a condenser, and a thermometer, 28.14 g of tetramethyldisiloxane, 1.65 g of concentrated hydrochloric acid, 10 g of purified water, and 48 g of a three-chain hydroxy silicone oil were added, and the mixture was stirred and heated to 50° C. in an oil bath. Then, 26.82 g of 4-pentylbiphenylboronic acid was dissolved in 130 g of methanol, and the mixture was added dropwise to the three-necked flask through a constant pressure dropping funnel. The mixture was refluxed at 50° C. for 6 h to obtain a colorless, transparent liquid product (i.e., intermediate product A).

[0173] 30 g of intermediate product A was added to a 100 mL three-necked flask equipped with a constant pressure dropping funnel, a condenser, and a thermometer, and the mixture was stirred and heated to 80 ° C in an oil bath. Then, a mixed solution containing 0.10790 g of Pt catalyst and 13.17 g of 1,6-hexanediol diacrylate was slowly added dropwise (30 minutes) to the three-necked flask through a constant pressure dropping funnel. The temperature was maintained between 80-85 ° C, and then the reaction was maintained at 85 ° C for 8 hours to obtain the above-mentioned viscosity-increasing agent.

[0174] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0175] The following Examples 1-6, Example 8, and Comparative Examples 1-2 were all cured by the following method to prepare the above-mentioned photothermal dual-curing silicone composition into a microlens in Mini LED, and the components were weighed according to the weight ratios in Table 1. Example 7 was cured by the following method to prepare the above-mentioned silicone composition into a microlens in Mini LED.

[0176] The curing methods of Examples 1-6, Example 8 and Comparative Examples 1-2 comprise the following steps:

[0177] The compositions prepared in each example or comparative example were cured under irradiation with a UV-LED lamp having a wavelength of 365 nm and a light radiation energy of 300 mJ / cm 2 , and then baked at 150℃ for 3h for thermal curing.

[0178] The curing method of Example 7 comprises the following steps:

[0179] The organosilicon composition of Example 7 was baked at 150° C. for 3 h.

[0180] The specific steps are as follows:

[0181] Table 1

[0182]

[0183]

[0184] In Table 1, A-1 to A-5 are medium-refractive-index vinyl-terminated MT-type hydroxyphenyl polysiloxanes with different hydroxyl contents.

[0185] B is a linear vinyl-terminated phenyl polysiloxane.

[0186] C-1 to C-3 are linear hydrogen-terminated phenyl polysiloxanes with different hydrogen contents.

[0187] D is a hydrophobic fumed silica.

[0188] E is a tackifying agent.

[0189] F is a photothermal curing platinum catalyst.

[0190] G is a condensation catalyst.

[0191] F-1 is a thermal platinum catalyst.

[0192] H / Vi is the ratio of hydrogen groups to vinyl groups in the raw material components.

[0193] Performance testing:

[0194] The microlenses (the photothermal dual-curing silicone compositions after curing) prepared in Examples 1-8 and Comparative Examples 1-2 were tested. The test results are shown in Table 2.

[0195] Test method:

[0196] Hardness (Shore D): Refer to GB / T 2411-2008;

[0197] Tensile strength (MPa): refer to GB / T34709-2017;

[0198] Light transmittance (%): UV-visible light photometer was used for testing. Solid samples were prepared into 3 cm x 1 cm x 1 mm strips for testing. The test wavelength was 450 nm.

[0199] Thixotropy: The thixotropic index is tested using an NDJ-1 rotary viscometer in accordance with GB7193.1-87. The viscosity of the liquid silicone rubber is measured at 6 r / min and 60 r / min using the same rotor, and the thixotropic index is calculated. The thixotropic index K = n1 / n (n1 is the viscosity value at 6 r / min, and n2 is the viscosity value at 60 r / min).

[0200] Shear Strength (MPa): Referring to standard GBT1393692, a glass shear specimen was prepared using silicone encapsulant and the shear strength was measured using a universal material testing machine. The shear strength determines the adhesive properties of the silicone encapsulant.

[0201] Aspect ratio: 0.5 g of the silicone composition was dropped onto a glass sheet. After curing, the diameter and height of the droplet were measured, and the height / diameter ratio was calculated to evaluate its formability.

[0202] Thermal weight loss rate (%): The cured material was baked at 260°C for 72 hours and the weights before and after were recorded. The weight loss rate was calculated to evaluate the heat resistance of the material.

[0203] Refractive index: Tested in accordance with GB / T 6448-2008.

[0204] Vinyl content (%): Refer to standard GB / T 28610-2012 and test by iodine titration method.

[0205] Phenyl content (%): Based on the known vinyl content, the phenyl content was calculated by the integral ratio of the proton characteristic peaks of phenyl (chemical shift δ7.0-8.0) and vinyl (chemical shift δ5.0-6.5) in the H-NMR spectrum.

[0206] Hydroxyl content (%): Based on the known vinyl content, the hydroxyl content is calculated by the integral ratio of the proton characteristic peaks of hydroxyl (chemical shift δ 3.6-4.2) and vinyl (chemical shift δ 5.0-6.5) in the H-NMR spectrum.

[0207] Table 2

[0208]

[0209] As shown in Table 2, Examples 1-4 have significantly higher thixotropy than Comparative Examples 1 and 2. This is because the components of Examples 1-4 all contain MT-type vinyl hydroxyphenyl polysiloxane, while the components of Comparative Examples 1-2 are non-hydroxy-type phenyl polysiloxane. This indicates that the silanol groups in the MT-type vinyl hydroxyphenyl polysiloxane can form an effective three-dimensional hydrogen bond network with fumed silica, thereby improving the thixotropy of the material.

[0210] The transparency of Comparative Example 1 is significantly reduced compared with Examples 1-4. The reason is that polysiloxane with a high phenyl content is used in Comparative Example 1. High phenyl polysiloxane has a high refractive index, which is much higher than the refractive index of fumed silica as a thixotropic agent, resulting in optical incompatibility.

[0211] Compared with Example 5, Example 1 has higher tensile strength and hardness, and also performs better in terms of thermal aging, which shows that the addition of a condensation catalyst in the composition can effectively promote the cross-linking reaction of silanol groups during thermal curing, thereby further improving the cross-linking density of the cured material.

[0212] The comparison of the thixotropy of Example 1 and Example 6 shows that fumed silica is the basis for forming thixotropy, and the addition of thixotropic fumed silica is indispensable.

[0213] Examples 1 and 7, respectively, utilize a photothermal curing system and a single heat curing system. While the materials exhibit the same thixotropy, applying heat curing directly after dispensing molding results in a decrease in viscosity and a change in thixotropy. This results in a decrease in the height of the hemispherical shape, an increase in its diameter, and a decrease in its aspect ratio. In contrast, Example 1 utilizes initial light curing at room temperature, followed by a deep curing process using heat. This minimizes the effects of temperature on molding and fundamentally eliminates the potential for air leakage from the chip's bottom.

[0214] In addition, the shear force of Comparative Examples 1 to 2 and Example 5 is significantly lower, indicating that the silanol group and condensation catalyst in the structure can effectively increase the shear force of the material. The slightly lower shear force in Example 3 is due to the small amount of resin used in the composition and the low colloid strength.

[0215] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A photothermal dual-curing silicone composition, characterized by: The raw materials of the photothermal dual-curing silicone composition include the following components: Vinyl terminated MT type hydroxyphenyl polysiloxane; Linear vinyl-terminated methylphenyl polysiloxane; Linear hydrogen-terminated phenyl polysiloxane; catalyst; The vinyl-terminated MT-type hydroxyphenyl polysiloxane is a phenyl polysiloxane containing silanol groups and silanyl groups.

2. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The raw materials include the following components in parts by mass: Vinyl-terminated MT-type hydroxyphenyl polysiloxane, 60-80 parts; Linear vinyl-terminated methylphenyl polysiloxane, 2 to 10 parts; Linear hydrogen-terminated phenyl polysiloxane, 18 to 33 parts.

3. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The molecular formula of the vinyl-terminated MT-type hydroxyphenyl polysiloxane is: (MeSiO 3 / 2 ) x (PhSiO 3 / 2 ) y (R 1 2SiO) z (R 2 2SiO 1 / 2 ) m , formula (1); In formula (1), R 1 are independently selected from one of methyl, phenyl, alkoxy and hydroxyl groups, and the number of hydroxyl groups is not 0; x, y, z and m are values greater than 0; R 2 The vinyl-terminated MT-type hydroxyphenyl polysiloxane has a phenyl group mass fraction of 8% to 32%.

4. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The molecular formula of the linear vinyl-terminated methylphenyl polysiloxane is: (Me2SiO) x (Ph2SiO) y (R2ViSiO 1 / 2 )2, formula (2); In formula (2), R2 is independently selected from methyl or phenyl; x and y are respectively values greater than 0, and the mass fraction of the phenyl group in the linear vinyl-terminated methylphenyl polysiloxane is 8% to 32%.

5. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The molecular formula of the linear hydrogen-terminated phenyl polysiloxane is: (MePhSiO) x (MeHSiO) y (Me2SiO) z (R 3 2HSiO 1 / 2 )2, formula (3); In formula (3), R 3 are independently selected from methyl or phenyl; x, y, and z are values greater than 0, and the mass fraction of the phenyl group in the linear hydrogen-terminated phenyl polysiloxane is 8% to 32%.

6. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The raw material components of the photothermal dual-curing silicone composition also include a filler, which is selected from fumed silica or precipitated silica; preferably, the filler is fumed silica; more preferably, the filler is hydrophobic fumed silica.

7. The photothermal dual-curing silicone composition according to claim 1, characterized in that: The catalyst includes a photothermal curing platinum catalyst and a condensation catalyst.

8. The photothermal dual-curing silicone composition according to claim 7, characterized in that: The photothermal curing platinum catalyst is a cyclopentadiene complex of platinum.

9. A microlens in a Mini LED, characterized by: The invention comprises the photothermal dual-curing silicone composition according to any one of claims 1 to 8.

10. The method for preparing a microlens in a Mini LED according to claim 9, wherein: The following steps are involved: The light-heat dual-curing silicone composition is dispensed and formed on the surface of the LED chip, and then cured by light radiation and heat in sequence to obtain the microlens.

Images