A high-refractive-index silicone OCR optical adhesive and its UV-low temperature heat-moisture three-stage synergistic curing process

Abstract

This invention discloses a high-refractive-index silicone OCR optical adhesive and its UV-low temperature heat-humidity three-stage synergistic curing process. The adhesive comprises a composite resin matrix, a high-phenyl hydrogen-containing silicone resin crosslinking agent, modified nanoparticles, and a ternary catalyst system. The composite resin matrix is ​​composed of vinyl high-phenyl silicone resin and epoxy phenyl silicone resin in a mass ratio of 60-70:30-40. This invention achieves an adjustable refractive index within the range of 1.5-1.6 through synergistic modification of the high-phenyl resin and nanoparticles, solving the problem of low refractive index in existing technologies that cannot be adapted to high-precision automotive optical components. Simultaneously, it maintains a transmittance >98% and a haze <0.3%.

Description

Technical Field

[0001] This invention belongs to the field of optical materials technology, specifically involving a high-refractive-index silicone OCR optical adhesive and its UV-low temperature heat-humidity three-stage synergistic curing process. Background Technology

[0002] As automotive display technology evolves towards larger screens, curved surfaces, and higher resolutions, the performance requirements for optical adhesives in components such as central control screens and head-up displays (HUDs) are becoming increasingly stringent. Silicone liquid OCR, due to its excellent resistance to high and low temperatures, weather resistance, and optical stability, has become the preferred material for automotive display bonding.

[0003] However, existing silicone OCR technology faces significant technical bottlenecks: traditional silicone resins have a refractive index between 1.48 and 1.52, which is insufficiently compatible with the refractive index of automotive glass (refractive index 1.52) and HUD optical lenses, leading to reflection and refraction losses during light transmission and affecting display clarity. Regarding curing methods, pure thermal curing requires temperatures above 100°C, which can easily cause polarizer aging and substrate deformation. Pure UV curing, on the other hand, creates curing dead zones in the frame shadow area, resulting in insufficient adhesive adhesion and easy delamination after long-term use. Introducing high-phenyl groups or nanoparticles to increase the refractive index often leads to poor compatibility and increased light scattering, resulting in decreased light transmittance (below 98%), reduced crosslinking activity, and slower curing speed. Furthermore, nanoparticles are prone to agglomeration during long-term storage, causing adhesive failure. Organotin catalysts have potential biotoxicity, and the high cost of raw materials and the need for production line modifications limit industrialization.

[0004] The automotive environment must withstand extreme temperature cycling from -40℃ to 85℃. Existing solutions often lack long-term stability data for this scenario, making it difficult to meet the wide-temperature requirements of automotive electronics. A method for preparing a high-refractive-index nanocomposite silicone encapsulating material (publication number: CN109161020B) employs an in-situ nanoparticle generation process to directly generate ZrO2 / TiO2 nanoparticles. This solves the problems of particle agglomeration and poor compatibility encountered when first synthesizing nanoparticles and then doping them into an organic substrate. It also improves the refractive index of the silicone resin material, making it suitable for high-refractive-index optical composite films, LED encapsulating materials, optical sensors, and other fields. While this patent solves the problems of "nanoparticle agglomeration + high refractive index," it has two major drawbacks: curing relies on temperatures above 100℃ (which can easily lead to aging of automotive polarizers); and it lacks a UV / wet curing design (which cannot solve the curing dead zones in the shadow areas of curved edges).

[0005] Therefore, developing a silicone OCR with a refractive index between 1.5 and 1.6, a light transmittance of >98%, the ability to cure rapidly at low temperatures and without dead angles, and the ability to maintain long-term stability, be environmentally friendly, have low cost and be compatible with production lines has become an urgent need in the automotive display field. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a high refractive index silicone OCR optical adhesive and its UV-low temperature heat-humidity three-stage synergistic curing process.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high refractive index fast-curing organosilicon OCR optical adhesive, characterized in that it is composed of a composite resin matrix, a high-phenyl hydrogen-containing silicone resin crosslinking agent, modified nanoparticles and a ternary catalyst; wherein, the composite resin matrix is ​​composed of vinyl high-phenyl silicone resin and epoxy phenyl silicone resin in a mass ratio of 60-70:30-40.

[0010] As a preferred embodiment of the high refractive index fast-curing organosilicon OCR optical adhesive of the present invention, wherein the mass ratio of vinyl high phenyl silicone resin to epoxy phenyl silicone resin in the composite resin matrix is ​​62-68:32-38.

[0011] As a preferred embodiment of the high refractive index fast-curing organosilicon OCR optical adhesive of the present invention, wherein the vinyl high phenyl silicone resin is obtained by compounding vinyltrimethoxysilane and phenylethyltriethoxysilane in a molar ratio of 0.1~1:0.1~1.

[0012] As a preferred embodiment of the high refractive index fast-curing organosilicon OCR optical adhesive of the present invention, the phenyl mass fraction of the vinyl high-phenyl silicone resin is 45%-55%, and the phenyl mass fraction of the epoxy phenyl silicone resin is 40%-50%.

[0013] As a preferred embodiment of the high refractive index fast curing organosilicon OCR optical adhesive of the present invention, the modified nanoparticles include one of ZrO2 and TiO2, with a particle size of 10-30nm, and a doping amount of 2%-5% of the mass of the composite resin matrix, and the surface is modified by a mixture of KH570 and polyether modified siloxane.

[0014] As a preferred embodiment of the high refractive index fast-curing silicone OCR optical adhesive of the present invention, the mass ratio of KH570 to polyether modified siloxane is 30-80:1.

[0015] As a preferred embodiment of the high refractive index rapid curing organosilicon OCR optical adhesive of the present invention, the ternary catalyst system includes a platinum catalyst, an onium salt photocatalyst, and a wet curing condensation reaction catalyst; the wet curing condensation reaction catalyst includes an organotin catalyst and a titanate catalyst; wherein the amount of titanate catalyst is 0.5%-0.8% of the mass of the composite resin matrix, and the amount of organotin catalyst is 0.3%-0.5% of the mass of the composite resin matrix; the dispersion medium of the ternary catalyst system includes one of phenylmethyl silicone oil and phenyl vinyl silicone oil.

[0016] As a preferred embodiment of the high refractive index fast-curing organosilicon OCR optical adhesive of the present invention, wherein: the mass fraction of the platinum catalyst is 3000 ppm of the composite resin matrix, the mass fraction of the onium salt photocatalyst is 0.8~1.2% of the composite resin matrix, and the mass fraction of the organotin catalyst is 0.3~0.5% of the composite resin matrix.

[0017] Another objective of this invention is to overcome the shortcomings of the prior art and provide a three-stage synergistic curing process for high refractive index silicone OCR optical adhesive, including UV irradiation for 10-15s for surface drying, thermal curing at 70℃ for 25-30min, and wet curing at 25℃ and 60%RH for 20-24h for complete curing.

[0018] As a preferred embodiment of the UV-low temperature heat-humidity three-stage synergistic curing process described in this invention, the UV surface drying light intensity is 900-1100mW / cm², and the irradiation time is 12-14s.

[0019] Beneficial effects of this invention: (1) The refractive index of the present invention is significantly improved and adjustable: through the synergistic modification of high phenyl resin and nano-hybrid, the refractive index is adjustable in the range of 1.5-1.6, which solves the problem that the refractive index of the prior art is too low and cannot be adapted to high-precision optical components in vehicles. At the same time, the light transmittance is maintained at >98% and the haze is <0.3%; (2) Based on improving the refractive index, this invention optimizes the crosslinking agent and catalyst system, which shortens the UV surface drying time to 12-14s, the low temperature thermal curing time to 25-28min, and the wet curing completion time to 20-22h, improving the curing efficiency by 17%-20% compared with the prior art; (3) The peel strength of the adhesive layer after curing is increased to 1.5-1.8 N / mm, the yellowing index of resistant to damp heat aging is ≤0.8, and the performance decay is <5% after high and low temperature cycles (50 times), which meets the long-term use requirements of extreme vehicle environment; (4) This invention provides an environmentally friendly alternative to tetrabutyl titanate catalyst, which is free of organotin toxicity and achieves 6-month room temperature storage stability through nanoparticle compound modification, thus solving the pain point of industrial storage. (5) The present invention reduces the cost to RMB 58 / kg through raw material optimization and is compatible with existing vehicle production lines (dispensing and curing equipment). Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is an image of component A in Example 1 of the present invention.

[0021] Figure 2 This is a diagram of the mixed adhesive solution before curing in Example 1 of the present invention. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0025] Unless otherwise specified, all raw materials used in the embodiments of this invention are commercially available. See Table 1 for details.

[0026] Table 1

[0027] The performance of the materials prepared in the examples and comparative examples was tested according to the following methods: Refractive index test: Measured using an Abbe refractometer at a wavelength of 589 nm. The test was conducted in accordance with ASTM D1747, "Method for Testing the Refractive Index of Viscous Materials".

[0028] Transmittance test: The test shall be conducted in accordance with WJ742-1994 <<Test Method for Transmittance of Adhesives for Optical Instruments>>.

[0029] Haze test: The test shall be conducted in accordance with GB / T2410-2008 <<Determination of light transmittance and haze of transparent plastics>>.

[0030] Peel strength test: The test shall be conducted in accordance with GB / T7124-2008 <<Determination of tensile shear strength of adhesives>>.

[0031] Yellowing index under damp heat aging: A 50mm×50mm×0.5mm sample was cut and aged at 85℃ and 85%RH for 1000h. After cooling for 2h, the YI value was measured. Among them, X, Y, and Z are the tristimulus values ​​measured by spectrophotometer. The value was calculated according to YI=100×(1.28X-1.06Z) / Y, and the average value of YI was used as the result.

[0032] High and low temperature cycling test: a reliability test simulating the extreme environment of an vehicle, with the conditions being "-40℃ (2h) → room temperature (1h) → 85℃ (2h) as 1 cycle, for a total of 50 cycles", used to evaluate the performance stability of the adhesive layer under drastic temperature fluctuations.

[0033] Example 1 (1) Preparation of vinyl-polyphenyl silicone resin (component A) Add 0.7 mol vinyltrimethoxysilane, 0.3 mol phenethyltriethoxysilane, 1.3 mol diphenylsilanediol and 150 mL anhydrous ethanol to a 500 mL three-necked flask equipped with a condenser and a stirrer, and stir until homogeneous; Add 0.05 mol hydrochloric acid (concentration 0.1 mol / L) as a catalyst, heat to 70℃, and react at a constant temperature for 8 hours; After the reaction was completed, 0.05 mol sodium hydroxide solution (concentration 0.1 mol / L) was added to neutralize to pH=7, and the temperature was raised to 80℃ and the solvent and low-boiling substances were removed by vacuum distillation to obtain vinyl high-phenyl silicone resin with a phenyl mass fraction of 50%.

[0034] Figure 1 This is an image of component A in Example 1 of the present invention.

[0035] (2) Preparation of epoxy-based phenyl silicone resin (component B) Add 1 mol KH560, 1 mol diphenylsilanediol and 120 mL toluene to a 500 mL three-necked flask and stir to dissolve; Add 0.03 mol of D296R strong base anion exchange resin as a catalyst, heat to 85℃, and react at a constant temperature for 9 hours; The catalyst was removed by filtration, and toluene and impurities were removed by vacuum distillation at 100°C to obtain epoxy phenyl silicone resin with a phenyl mass fraction of 45%, a refractive index of 1.54, and a viscosity of 800 mPa·s (25°C).

[0036] (3) Preparation of high phenyl bifunctional hydrogen-containing silicone resin (crosslinking agent) Add 0.5 mol phenyltrichlorosilane, 0.3 mol dimethyldichlorosilane, 0.2 mol methyldichlorosilane and 100 mL toluene to a 500 mL three-necked flask, stir and cool to 0 °C; Slowly add 150 mL of deionized water over a time of 1 hour, keeping the temperature ≤5℃. After the addition is complete, raise the temperature to 25℃ and react for 3 hours. After standing and separating into layers, the organic phase was washed with deionized water until neutral, 5g of anhydrous magnesium sulfate was added and dried for 4 hours. After filtration, the temperature was raised to 110℃ and the toluene was removed by vacuum distillation to obtain a high-phenyl hydrogen-containing silicone resin with a Si-H content of 0.20%, a phenyl mass fraction of 55%, and a refractive index of 1.58.

[0037] (4) Surface modification of ZrO2 nanoparticles Take 10g of ZrO2 nanoparticles (15nm) and dry them in a vacuum drying oven at 100℃ for 2h to completely remove the moisture and trace organic impurities adsorbed on the particle surface. This is to avoid moisture interfering with the subsequent hydrolysis reaction of the silane coupling agent and impurities affecting the bonding force of the modified layer. After cooling to room temperature, add 200mL of anhydrous ethanol as a dispersion medium. The low surface tension can reduce the van der Waals forces between particles and can also dissolve KH570 and BYK-333, achieving uniform contact between the modifier and the particles.

[0038] A three-necked flask containing the suspension was fixed in an ultrasonic cleaner. The ultrasonic power was set to 300W and the ultrasonic time to 30min. During the ultrasonic process, the temperature of the suspension was controlled at 25±3℃ using an ice bath (to avoid the evaporation of ethanol due to ultrasonic heat generation and to prevent the particles from re-aggregating due to high temperature). After the ultrasonic process, the state of the suspension was observed. It should reach the state of "uniform milky white, no obvious sedimentation, and no stratification after standing for 30min". At this time, the ZrO2 nanoparticles have been dispersed into monodisperse or oligomer states, providing sufficient reaction sites for subsequent modification reactions.

[0039] 2g of γ-methacryloxypropyltrimethoxysilane (KH570) was slowly added dropwise to the above suspension, and mechanical stirring was started (500 r / min). Stirring was continued for 15 min to ensure KH570 was uniformly dissolved and dispersed in the system. Then, 0.04g of polyether-modified siloxane (BYK-333) was weighed, diluted with 10mL of anhydrous ethanol, and slowly added to the system. Stirring was continued for 10 min to achieve uniform mixing of the two modifiers. The three-necked flask was placed in a constant temperature water bath and heated to 60℃, and the reaction was stirred for 4 h. Centrifugation (8000 r / min, 15 min), washing three times with anhydrous ethanol, and vacuum drying at 80 °C for 6 h yielded surface-modified ZrO2 nanoparticles (long-lasting anti-agglomeration, with no significant agglomeration after 6 months of storage at room temperature).

[0040] (5) Preparation of OCR adhesive Component A and component B are mixed at a mass ratio of 65:35 and stirred until homogeneous to obtain a composite resin matrix. The phenyl content after mixing is 48%. Add 3% (based on matrix mass) of modified ZrO2 nanoparticles to the composite resin matrix, first ultrasonically disperse (300W, 15min), then stir at high speed (3000r / min, 15min) until homogeneous; Add 10% (based on matrix mass) of high-phenyl hydrogen-containing silicone resin crosslinking agent and stir until homogeneous; Add 3000 ppm platinum catalyst (based on matrix mass), 1.0% onium salt photocatalyst (based on matrix mass), and 0.4% organotin catalyst (based on matrix mass), and use phenyl vinyl silicone oil as the dispersion medium (the amount is 5 times the total mass of the catalyst) and ultrasonically disperse for 5 min; (6) Three-stage curing process UV surface drying: Using a 365nm UV lamp with a light intensity of 1000mW / cm², the adhesive surface is rapidly cured in 11 seconds without sticking, and existing UV-cured tunnels can be reused. Low-temperature thermosetting: Place the sample in a 70℃ oven and cure at a constant temperature for 23 minutes until the adhesive is completely cured. Existing constant temperature ovens can be reused. Moisture curing completion: Place the cured sample in an environment of 25℃ and 60%RH for 19 hours to complete the moisture curing of the shaded area.

[0041] Figure 2 This is a diagram of the mixed adhesive solution before curing in Example 1 of the present invention.

[0042] Example 2 The difference from Example 1 is that in step (1), 0.9 mol vinyltrimethoxysilane, 0.3 mol phenethyltriethoxysilane, and 1.3 mol diphenylsilanediol are added, and the phenyl content of the synthesized product is 40%; in step (5), component A and component B are mixed at a mass ratio of 60:40 and stirred evenly to obtain a composite resin matrix. After mixing, the phenyl content is about 42%. 2% (based on the matrix mass) of modified ZrO2 nanoparticles are added to the composite resin matrix, and phenylmethyl silicone oil is used as the dispersion medium (the amount is 5 times the total mass of the catalyst); in step (6), the irradiation time is 13s, the low-temperature curing time is 28min, and the wet curing completion time is 22h; the rest is the same as in Example 1.

[0043] Example 3 The difference from Example 1 is that in step (1), 0.7 mol vinyltrimethoxysilane, 0.3 mol phenethyltriethoxysilane, and 1.6 mol diphenylsilanediol are added, and the phenyl content of the synthesized product is 58%; in step (5), component A and component B are mixed at a mass ratio of 75:25 and stirred evenly to obtain a composite resin matrix. After mixing, the phenyl content is about 55%. 5% (based on the matrix mass) of modified ZrO2 nanoparticles are added to the composite resin matrix, and phenylmethyl silicone oil is used as the dispersion medium (the amount is 5 times the total mass of the catalyst); in step (6), the irradiation time is 14s, the low-temperature curing time is 27min, and the wet curing completion time is 21h; the rest is the same as in Example 1.

[0044] Example 4 The difference from Example 1 is that the 0.4% organotin catalyst (based on matrix mass) in step (5) is replaced with 0.6% tetrabutyl titanate; in step (6), the UV surface drying irradiation is 1 second longer than in Example 1, the isothermal curing time is 1 minute longer than in Example 1, the wet curing completion placement time is 1 hour longer than in Example 1, and the rest is the same as in Example 1, resulting in an environmentally friendly OCR adhesive.

[0045] Example 5 The difference from Example 1 is that in step (5), phenyl methyl silicone oil is used as the dispersion medium (the amount is 5 times the total mass of the catalyst); in step (6), the UV surface drying time is 12s, the constant temperature curing time is 25min, and the wet curing completion placement time is 20h. The rest is the same as Example 1.

[0046] Example 6 The difference from Example 1 is that in step (4), ZrO2 nanoparticles are replaced with TiO2 nanoparticles (particle size 15nm, refractive index 2.5), the surface is modified by KH570 and polyether-modified siloxane, and the doping amount is adjusted to 2%. The rest is the same as Example 1.

[0047] Example 7 The difference from Example 1 is that the ZrO2 nanoparticles in step (4) are replaced with TiO2 nanoparticles (particle size 15nm, refractive index 2.5), the surface is modified by KH570 and polyether-modified siloxane, and the doping amount is adjusted to 4%. The rest is the same as Example 1.

[0048] Example 8 The difference from Example 1 is that in step (1), vinyltrimethoxysilane is replaced with vinyltriethoxysilane, and the amount of diphenylsilanediol is adjusted to 1.2 mol. The rest is the same as in Example 1.

[0049] Example 9 The difference from Example 1 is that the organotin catalyst in step (5) is replaced with an aluminate coupling agent (DL-411) at a dosage of 0.7%, and the wet curing time in step (6) is 23 hours. The rest is the same as Example 1.

[0050] Table 2 Relevant Performance Tables of Examples

[0051] As shown in Table 2, Example 1 is the best example.

[0052] Comparative Example 1 The difference between this comparative example and Example 1 is that: phenethyltriethoxysilane in step (1) is replaced with vinyltrimethoxysilane, and the amount of diphenylsilanediol is reduced from 1.3 mol to 0.9 mol; the amount of organotin catalyst in step (5) is 0.6%, and the rest is the same as in Example 1.

[0053] Comparative Example 2 The difference between this comparative example and Example 1 is that: phenethyltriethoxysilane in step (1) is replaced with vinyltrimethoxysilane; the mass ratio of A / B components of the composite resin matrix in step (5) is replaced with "58:42" instead of "65:35"; the other raw materials, proportions and steps (1)-(4) and (6) are completely consistent with Example 1.

[0054] Comparative Example 3 The difference between this comparative example and Example 1 is as follows: 0.7 mol vinyltrimethoxysilane + 0.3 mol phenethyltriethoxysilane + 1.3 mol diphenylsilanediol in step (1) is replaced with 0.9 mol vinyltrimethoxysilane + 0.1 mol phenethyltriethoxysilane + 0.7 mol diphenylsilanediol + 0.6 mol ethylene glycol; "1 mol KH560 + 1 mol diphenylsilanediol" in step (2) is replaced with "1 mol KH560 + 0.4 mol diphenylsilanediol + 0.6 mol ethylene glycol"; the surface modification scheme of ZrO2 nanoparticles in step (4) is changed from "KH570 and polyether-modified siloxane (BYK-333) compound modification" to "single KH570 modification", specifically: only 2 g KH570 is added, 0.04 g BYK-333 is not added, and the amount of other raw materials is completely the same as in Example 1.

[0055] Comparative Example 4 The difference between this comparative example and Example 1 is that: phenethyltriethoxysilane in step (1) is replaced with vinyltrimethoxysilane; the dispersion medium in step (5) is replaced with "conventional methyl silicone oil (viscosity 500 mPa·s, 25°C, refractive index 1.41)" instead of "phenyl vinyl silicone oil". All other raw materials and steps are completely consistent with Example 1.

[0056] Comparative Example 5 The difference between this comparative example and Example 1 is that: phenethyltriethoxysilane in step (1) is replaced with vinyltrimethoxysilane; the modified ZrO2 nanoparticles in step (4) are removed (no nanoparticles are added), and only the binary resin system of "vinylphenyl silicone resin (component A) + epoxy phenyl silicone resin (component B)" is retained. The other raw materials, proportions and steps (1)-(3), (5)-(6) are completely consistent with Example 1.

[0057] Comparative Example 6 The difference between this comparative example and Example 1 is that: phenethyltriethoxysilane in step (1) is replaced with vinyltrimethoxysilane; the “wet curing completion” stage in step (6) is removed, and only the “UV surface drying + low temperature thermal curing” dual-stage process is used, breaking the three-stage synergistic design. The remaining raw materials, proportions and steps (1)-(5) are completely consistent with Example 1.

[0058] Table 3 Comparative Relevance Performance Table

[0059] The results are shown in Table 3. When the amount of organotin catalyst is higher than the preferred range (0.3~0.5%), although it does not affect the refractive index (because the refractive index is determined by the phenyl content and ZrO2), it causes significant negative effects: excessive catalyst leads to an excessively fast crosslinking reaction rate, stress concentration inside the adhesive layer, increased light scattering, decreased transmittance, and increased haze; excessive catalyst residue causes side reactions, the yellowing index of resistance to damp heat aging rises to 1.55 (far exceeding 0.65 in Example 1), and the transmittance decreases by 2.2% after 6 months of storage at room temperature; uneven crosslinking leads to a decrease in the interfacial bonding force between the adhesive layer and the substrate, the peel strength drops to 1.1 N / mm, and the peel strength further decreases to 0.75 N / mm after high and low temperature cycling, which cannot meet the long-term reliability requirements of automotive scenarios; the overall performance is inferior to that of Example 1, proving that the amount of organotin catalyst must be strictly controlled within the preferred range of 0.3~0.5%.

[0060] When the phenyl content of the composite resin matrix drops to 43%, the refractive index is only 1.50, which is lower than the refractive index requirement of automotive HUD optical components; the insufficient proportion of component A leads to a reduction in the active sites of crosslinking reaction, resulting in a significant decrease in curing efficiency; insufficient crosslinking density makes the adhesive layer structure loose, and the peel strength drops to 1.3 N / mm. After high and low temperature cycling, the peel strength further decreases to 1.0 N / mm, which is prone to delamination during long-term use; the loose structure makes it easy for moisture to penetrate, and the yellowing index of resistance to humid heat aging rises to 0.95. After high and low temperature cycling, the light transmittance decreases by 1.1%, which cannot meet the stability requirements of extreme automotive environments. Therefore, the mass ratio of components A / B needs to be controlled within the range of 62-68:32-38.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A high-refractive-index, fast-curing silicone OCR optical adhesive, characterized in that: It is composed of a composite resin matrix, a high-phenyl hydrogen-containing silicone resin crosslinking agent, modified nanoparticles, and a ternary catalyst; wherein, the composite resin matrix is ​​composed of vinyl high-phenyl silicone resin and epoxy phenyl silicone resin in a mass ratio of 60-70:30-40.

2. The high refractive index fast-curing silicone OCR optical adhesive according to claim 1, characterized in that: The mass ratio of vinyl-based phenyl silicone resin to epoxy-based phenyl silicone resin in the composite resin matrix is ​​62-68:32-38.

3. The high refractive index fast-curing silicone OCR optical adhesive according to claim 1, characterized in that: The vinyl high-phenyl silicone resin is obtained by compounding vinyltrimethoxysilane and phenylethyltriethoxysilane in a molar ratio of 0.1~1:0.1~1.

4. The high refractive index fast-curing silicone OCR optical adhesive according to claim 3, characterized in that: The vinyl-based high-phenyl silicone resin has a phenyl mass fraction of 45%-55%, and the epoxy-based phenyl silicone resin has a phenyl mass fraction of 40%-50%.

5. The high refractive index fast-curing silicone OCR optical adhesive according to claim 1, characterized in that: The modified nanoparticles include one of ZrO2 and TiO2, with a particle size of 10-30 nm and a doping amount of 2%-5% of the composite resin matrix mass. The surface is modified by a mixture of KH570 and polyether-modified siloxane.

6. The high refractive index fast-curing silicone OCR optical adhesive according to claim 4, characterized in that: The mass ratio of KH570 to polyether-modified siloxane is 30-80:

1.

7. The high refractive index fast-curing silicone OCR optical adhesive according to claim 1, characterized in that: The ternary catalyst system includes a platinum catalyst, an onium salt photocatalyst, and a wet-curing condensation reaction catalyst; the wet-curing condensation reaction catalyst includes an organotin catalyst and a titanate catalyst; wherein the amount of titanate catalyst is 0.5%-0.8% of the mass of the composite resin matrix, and the amount of organotin catalyst is 0.3%-0.5% of the mass of the composite resin matrix; the dispersion medium of the ternary catalyst system includes one of phenylmethyl silicone oil and phenyl vinyl silicone oil.

8. The high refractive index fast-curing silicone OCR optical adhesive according to claim 6, characterized in that: The platinum catalyst has a mass fraction of 0.3% of the composite resin matrix, the onium salt photocatalyst has a mass fraction of 0.8-1.2% of the composite resin matrix, and the organotin catalyst has a mass fraction of 0.3-0.5% of the composite resin matrix.

9. A UV-low temperature heat-humidity three-stage synergistic curing process for a high refractive index silicone OCR optical adhesive, characterized in that: This includes surface drying of high refractive index fast-curing silicone OCR optical adhesive by UV irradiation for 10-15 seconds, heat curing at 70℃ for 25-30 minutes, and wet curing at 25℃ and 60%RH for 20-24 hours.

10. The UV-low temperature heat-humidity three-stage synergistic curing process according to claim 9, characterized in that: The UV surface light intensity is 900-1100mW / cm², and the irradiation time is 12-14s.

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