Prism film, preparation method and application thereof

Abstract

The invention discloses a prism film, a preparation method and application thereof, and belongs to the field of optical films. Aiming at the problem that an existing prism film is poor in thermal stability, the prism film comprises a base material layer and a prism layer arranged on the surface of the base material layer, and the prism layer comprises the following components in parts by weight: 45-55 parts of a bifunctional aliphatic acrylate monomer; 28 to 35 parts of a monofunctional acrylate monomer containing a benzene ring; 0.3 to 0.8 part of a heat stabilizer; 2.5 to 4 parts of a VOC adsorbent; 0.8 to 1.2 parts of an interface passivating agent; and 1.5 to 1.8 parts of a photoinitiator. Through cooperation of the benzene ring monomer and the passivator, the problem of high-temperature interface reaction is solved; through the main monomer and the auxiliary monomer, the thermal expansion coefficient and rigidity of the resin are synergistically regulated and controlled, the performance difference with a base material is reduced, and the problems of interface permeation and structural deformation at high temperature are radically relieved; the heat stability and the chemical tolerance of the prism film are both achieved, and good optical performance is maintained; meanwhile, the content of VOC released under the high-temperature condition is low, and environment friendliness is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical films, and more particularly relates to a prism film, a preparation method and application thereof. BACKGROUND

[0002] With the development of intelligent cockpit display technology towards high definition and large size, as the core optical component of liquid crystal instrument panel, vehicle-mounted central control screen and HUD (head-up display system), the prism film directly determines the brightness gain and visual clarity of the display picture through the refraction and convergence of light by the prism microstructure, and the design difference of the prism structure and the adaptive material system become the key factors affecting the high temperature stability, VOC release and optical performance of the prism film. The current mainstream prism structure of vehicle-mounted prism film mainly includes triangular prism (pitch 25-50 pm, top angle 90-100°), trapezoidal prism (pitch 30-60 pm, top angle 110-120°) and circular arc transition triangular prism (pitch 20-45 pm, top angle 95-105°, prism edge circular arc radius 1-3 pm) three types, and the technical bottlenecks faced by different prism structures in application are significantly different.

[0003] The triangular prism has a more direct light convergence path, and the brightness gain can generally reach 150%-170%, which is the mainstream choice for current vehicle display. However, the top angle of the prism structure is sharp (90-95°), and the stress concentration effect of the prism edge is obvious. In the vehicle high temperature environment (surface temperature 80-120℃), the thermal expansion coefficient of the traditional UV-cured acrylic resin is quite different from that of the PC substrate (resin thermal expansion coefficient about 80×10 -6 / ℃, PC substrate about 65×10 -6 / ℃), and the sharp prism edge of the prism is prone to interfacial penetration with the PC substrate. The resin molecular chain migrates to the interior of the PC substrate due to the intensified movement at high temperature, and the surface molecules of the PC substrate also diffuse to the resin layer, resulting in the formation of a mixed layer at the interface between the two, which causes deformation of the prism structure (prism edge collapse, top angle increase). Data shows that after conventional prism film using triangular prism is aged at 105℃ / 120h, the average increase of the prism top angle is 5-8°, the haze rises by >5%, and the brightness gain loss is more than 15%, which directly affects the virtual image clarity of the HUD display and the uniformity of the instrument panel picture.

[0004] The trapezoidal prism-shaped prism has an increased top angle of 110-120° and an increased edge width of 3-5 μm, and the stress concentration effect is weakened, and the risk of edge collapse at high temperature is reduced by about 30%. However, due to the lengthening of the light refraction path and the reflection loss of part of the light on the top plane of the prism, the brightness gain can only reach 130%-150%, which is difficult to meet the current demand for high brightness of vehicle-mounted displays (mainstream demand brightness gain ≥ 160%). At the same time, the thickness of the resin layer of the trapezoidal prism-shaped prism usually needs to be increased to 60-80 μm (the thickness of the triangular prism is usually 40-50 μm) to ensure the structural stability, which leads to an increase in the difficulty of deep curing during the UV curing process - traditional single-wavelength UV curing (such as only 365 nm or 395 nm) is difficult to penetrate the thick resin layer, and the phenomenon of "complete surface curing and incomplete deep curing" is prone to occur. The small molecules (monomers, oligomers) of the uncured resin are more prone to migrate and release at high temperatures, and the VOC release amount still remains at 90-110 μg / g, which cannot meet the low VOC requirement; and the contact area between the thick resin layer and the PC substrate is larger, and the molecular interaction between the interface is stronger, and there is still a risk of interface peeling at high temperatures for a long time (after aging at 105°C / 120h, the interface adhesion is usually 3-4 levels, and the peeling area is 35%-65%). SUMMARY

[0005] 1. Problem to be solved In view of the poor thermal stability of the existing prism film, the present application provides a prism film, a preparation method and an application thereof. The present application solves the problem of high-temperature interface reaction through the cooperation of benzene ring monomers and passivation agents; through the cooperation of main monomers and auxiliary monomers, the thermal expansion coefficient and rigidity of the resin are cooperatively controlled, and the performance difference with the substrate is reduced, thereby alleviating the interface penetration and structural deformation problems at high temperatures from the root; the thermal stability and chemical resistance of the prism film are achieved, and the optical performance is maintained; at the same time, the VOC content released under high temperature conditions is low, and the environment is friendly.

[0006] 2. Technical scheme To solve the above problems, the present application adopts the following technical scheme.

[0007] A prism film, comprising a substrate layer and a prism layer arranged on the surface of the substrate layer, the prism layer comprising the following components in parts by weight: a bifunctional aliphatic acrylate monomer: 45-55 parts; a monofunctional acrylate monomer containing a benzene ring: 28-35 parts; a thermal stabilizer: 0.3-0.8 parts; a VOC adsorbent: 2.5-4 parts; an interface passivation agent: 0.8-1.2 parts; a photoinitiator: 1.5-1.8 parts.

[0008] Furthermore, the VOC adsorbent is a modified zeolite molecular sieve, wherein the modification method of the modified zeolite molecular sieve is as follows: Pretreatment of zeolite molecular sieves; The modifier, anhydrous ethanol, and pretreated zeolite molecular sieve were mixed and stirred to obtain a mixture. The mixture was subjected to a process to remove unreacted modifiers, followed by drying to obtain modified zeolite molecular sieves.

[0009] Furthermore, the modifier is γ-aminopropyltriethoxysilane, and the modifier, anhydrous ethanol, and pretreated zeolite molecular sieve are mixed in the following mass ratio: pretreated zeolite molecular sieve: γ-aminopropyltriethoxysilane: anhydrous ethanol = (90~110): (4~6): (190~210).

[0010] Furthermore, the bifunctional aliphatic acrylate monomer is hexanediol diacrylate; the benzene ring-containing monofunctional acrylate monomer is phenoxyethyl acrylate.

[0011] A method for preparing a prism film as described in any of the above technical solutions includes the following steps: S1: A prism layer slurry is formed by mixing a difunctional aliphatic acrylate monomer, a monofunctional acrylate monomer containing a benzene ring, a heat stabilizer, a VOC adsorbent, an interface passivator, and a photoinitiator in proportion to weight. S2: The prism layer slurry is coated onto the PET release film to obtain the prism layer coating, and the prism structure is formed on the prism layer coating by a mold; S3: UV pre-curing of prism layer coating: UV wavelength 360~370nm, irradiation intensity 40~60mW / cm², time 2~4s; S4: Perform UV curing on the prism layer coating: UV wavelength 390~400nm, irradiation intensity 90~130mW / cm², time 8~12s; S5: Peel off the prism layer coating from the PET release film, perform pretreatment, and then laminate it with the substrate to obtain the prism film.

[0012] Furthermore, in step S1, a high-speed disperser is used to mix the components, and the mixing of the high-speed disperser includes two stages: premixing and main mixing. The speed and time of the high-speed disperser in the premixing stage are both less than those in the main mixing stage.

[0013] Furthermore, in step S2, the mold surface is provided with periodically arranged microstructure units, which are composed of isosceles triangular prism structures and rectangular base structures arranged alternately in the same direction.

[0014] Furthermore, the pretreatment in step S5 includes vacuum drying and heat setting of the prism layer coating after the PET release film has been peeled off. The heat setting is to set the coating in a hot air oven at 75℃~85℃ for 0.5h~1.5h.

[0015] An application of a prism film as described in any of the above technical solutions, applied in at least one in-vehicle scenario including dashboard, central control screen, and HUD.

[0016] 3. Beneficial effects (1) This invention adds two types of acrylate monomers to the components. The difunctional aliphatic acrylate monomer is used as the main monomer. Compared with higher functional monomers, this type of monomer has a lower risk of molecular chain migration at high temperature and better flexibility while ensuring the curing speed. The monofunctional acrylate monomer containing benzene rings is used as the auxiliary monomer. The benzene ring structure of this type of monomer can enhance the rigidity of the resin and reduce the coefficient of thermal expansion, thereby reducing the difference with the substrate material and alleviating the stress concentration at the edge. In addition, the heat stabilizer strengthens the inhibition of high-temperature oxidation and avoids the increase in haze caused by resin yellowing. The VOC adsorbent can specifically adsorb HDDA residual monomer and TPO-L decomposition fragments to reduce VOC release. The interface passivator forms a dense siloxane film at the interface between the acrylate and the substrate, blocking molecular penetration and chemical bonding and avoiding edge collapse. Finally, the thermal stability and chemical resistance of the prism film are achieved, thereby maintaining good optical performance. At the same time, the VOC content released under high temperature conditions is low and environmentally friendly. (2) This invention utilizes modified zeolite molecular sieves as VOC adsorbents. The uniform microporous structure of the zeolite molecular sieves itself is used to adsorb specific molecules, which is effective, widely available, and relatively low in cost. At the same time, γ-aminopropyltriethoxysilane is used to modify it, so that the adsorption of zeolite molecular sieves can be enhanced from simple adsorption to physical-chemical synergistic adsorption, further enhancing the adsorption of HDDA residual monomers and TPO-L decomposition fragments. Furthermore, the ratio of auxiliary modifier, anhydrous ethanol and zeolite molecular sieves is adjusted to achieve a balance between adsorption performance, modification efficiency and cost. (3) The preparation method of the present invention creatively adopts two-stage curing. The first stage of pre-curing prioritizes the initial cross-linking of the coating surface and prism edges, fixes the microstructure of the prism, and reduces structural deformation in the subsequent main curing stage. At the same time, low-intensity irradiation avoids excessive surface curing and leaves space for deep resin flow. The second stage of main curing is normal curing, which realizes the formation of the prism film. The two curing processes ensure the integrity of the prism structure and production efficiency. (4) The present invention also adopts a two-stage mixing process when mixing raw materials. Premixing achieves initial wetting and degassing of raw materials at low speed, forming a viscous and initially uniform slurry. The main mixing breaks the agglomeration between raw materials at higher speed and longer duration, achieving uniform dispersion and thus ensuring the uniformity and stability of the system. The two-stage mixing provides a smooth transition and sufficient dispersion time, ensuring sufficient mixing between raw materials and laying a good foundation for subsequent steps. Furthermore, vacuum drying in the pretreatment further enhances the removal efficiency of unreacted monomers and further reduces VOC residue. Heat setting eliminates the curing stress inside the coating and further improves high-temperature stability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the mold structure. Detailed Implementation

[0018] The present invention will now be further described with reference to specific embodiments and accompanying drawings.

[0019] A prism film includes a substrate layer and a prism layer disposed on the surface of the substrate layer, wherein the substrate layer and the prism layer are stacked together; the prism layer comprises the following components in parts by weight: Bifunctional aliphatic acrylate monomers: 45~55 parts; This type of monomer, as the main monomer, provides a crosslinking network, has a fast reaction speed, and can quickly form a three-dimensional network structure with high crosslinking density during photocuring; At the same time, while ensuring the curing speed, compared with other higher functional monomers, the bifunctional aliphatic acrylate monomers have lower molecular chain migration rate and better flexibility, reducing the risk of structural relaxation or deformation caused by intensified molecular chain segment movement at high temperatures, and ensuring thermal stability; Monofunctional acrylate monomers containing benzene rings: 28-35 parts; These monomers, used as auxiliary monomers, effectively improve the modulus and hardness of the cured resin due to the large, rigid structure of the benzene ring, resisting external deformation and reducing the coefficient of thermal expansion (experiments showed that the addition of these monomers, compared to the addition of a single acrylate, reduced the thermal expansion coefficient from 80 × 10⁻⁶). -6 / ℃ drops to 68~72×10 -6 / ℃), shrinkage and substrate (65×10) -6 The difference in materials ( / ℃) helps alleviate stress concentration at the edges; Heat stabilizer: 0.3~0.8 parts; The heat stabilizer enhances the inhibition of high-temperature oxidation and avoids the increase in haze caused by resin yellowing; VOC adsorbent: 2.5~4 parts; VOC adsorbent can specifically adsorb residual HDDA monomers and TPO-L decomposition fragments, reducing VOC release; Interface passivating agent: 0.8~1.2 parts; forms a dense siloxane film at the resin-substrate interface, blocking molecular penetration and chemical bonding, and preventing edge collapse; Photoinitiator: 1.5~1.8 parts, the curing reaction is initiated by the photoinitiator.

[0020] In this embodiment, the problem of high-temperature interfacial reaction between the substrate and resin is solved by synergistic interaction between benzene ring monomers and passivating agents. A bifunctional aliphatic acrylate monomer is used as the main monomer, and a benzene ring-containing monofunctional acrylate monomer is used as the auxiliary monomer. With appropriate ratios, the thermal expansion coefficient and rigidity of the resin are synergistically controlled, reducing the performance difference with the substrate material and fundamentally alleviating the problems of interfacial penetration and structural deformation at high temperatures. Simultaneously, the targeted selection of low-volatility luminescent initiators reduces small-molecule volatilization sources, forming a low-migration basic system with monomer-initiator synergy. Ultimately, this achieves a balance between thermal stability and chemical resistance of the prism film, thus maintaining good optical performance. Furthermore, the VOC content released under high-temperature conditions is low, making it environmentally friendly.

[0021] In one specific embodiment, the VOC adsorbent is a modified zeolite molecular sieve, wherein the modification method of the modified zeolite molecular sieve is as follows: Pretreatment of zeolite molecular sieves; The modifier, anhydrous ethanol, and pretreated zeolite molecular sieve were mixed and stirred to obtain a mixture. The mixture was subjected to a process to remove unreacted modifiers, followed by drying to obtain modified zeolite molecular sieves.

[0022] This embodiment modifies zeolite molecular sieves for use as VOC adsorbents. The zeolite molecular sieves themselves possess a uniform microporous structure, whose pore size can screen and adsorb small molecules of specific sizes (such as residual HDDA monomers and TPO-L photolysis fragments). This eliminates the need for additional microporous structure preparation, ensuring adsorption efficiency while reducing process complexity and cost. Furthermore, unmodified zeolite is a hydrophilic inorganic powder with extremely poor compatibility with hydrophobic acrylate resins, easily leading to agglomeration during mixing, which is detrimental to subsequent processes. Therefore, a modifier is used to modify the zeolite molecular sieve, changing the zeolite surface from hydrophilic to hydrophobic / oleophilic, greatly improving compatibility with the resin matrix. This enables nanoscale uniform dispersion, avoiding optical defects caused by uneven dispersion and weak interfacial bonding, which can become stress concentration points and reduce mechanical properties.

[0023] More specifically, the modifier is γ-aminopropyltriethoxysilane, and the modifier, anhydrous ethanol, and pretreated zeolite molecular sieve are mixed in the following mass ratio: pretreated zeolite molecular sieve : γ-aminopropyltriethoxysilane : anhydrous ethanol = (90~110):(4~6):(190~210). In this embodiment, the mass of the three components is limited as follows: The pretreated zeolite molecular sieve serves as the main body for adsorption, ensuring that there are enough adsorption sites in the system to capture VOCs within a suitable range, while avoiding the impact of excessive filler on the resin's curing kinetics, leveling, and final hardness / flexibility balance. γ-aminopropyltriethoxysilane, as the main agent for modification, is limited to a suitable range to ensure the formation of a dense and complete monomolecular modified layer on the surface of the pretreated zeolite molecular sieve, ensuring the modification effect without causing negative effects such as self-polymerization or reduced adsorption efficiency. Anhydrous ethanol, as a solvent, allows the modification reaction to proceed uniformly and gently within a suitable range, which is beneficial for forming a uniform coating layer and achieving efficient and complete modification. Furthermore, ethanol has a low boiling point and can be completely evaporated and removed during the drying step, leaving no residue.

[0024] In one specific embodiment, the bifunctional aliphatic acrylate monomer is hexanediol diacrylate, i.e., HDDA; the benzene ring-containing monofunctional acrylate monomer is phenoxyethyl acrylate, i.e., Phenoxyethylacrylate. The heat stabilizer is Irganox 1010; the photoinitiator is TPO-L.

[0025] A method for preparing a prism film as described in any of the above embodiments includes the following steps: S1: A prism layer slurry is formed by mixing a difunctional aliphatic acrylate monomer, a benzene ring-containing monofunctional acrylate monomer, a heat stabilizer, a VOC adsorbent, an interface passivator, and a photoinitiator according to the weight proportions. In this step, a high-speed disperser is used to mix the components, and the high-speed disperser mixing includes two stages: premixing and main mixing. The speed and time of the high-speed disperser in the premixing stage are both less than those in the main mixing stage. Step S1 primarily involves forming a uniformly mixed prism layer slurry. Therefore, this step employs a two-stage mixing process. Premixing, performed at low speeds, achieves initial wetting and degassing of the raw materials, resulting in a viscous and initially uniform slurry. The main mixing, performed at higher speeds and for longer durations, breaks up agglomeration between raw materials, achieving uniform dispersion and ensuring the homogeneity and stability of the system. This two-stage mixing provides a smooth transition and sufficient dispersion time, ensuring thorough mixing of the raw materials and laying a solid foundation for subsequent steps. S2: The prism layer slurry is coated onto the PET release film to obtain the prism layer coating, and the prism structure is formed on the prism layer coating by a mold; S3: UV pre-curing of prism layer coating: UV wavelength 360~370nm, irradiation intensity 40~60mW / cm², time 2~4s; S4: Perform UV curing on the prism layer coating: UV wavelength 390~400nm, irradiation intensity 90~130mW / cm², time 8~12s; S5: The prism layer coating is peeled off from the PET release film, pretreated, and then laminated with the substrate to obtain the prism film. Specifically, the pretreatment in this step includes vacuum drying and heat setting of the prism layer coating after the PET release film has been peeled off. The heat setting is carried out in a hot air oven at 75℃~85℃ for 0.5h~1.5h. Vacuum drying further enhances the removal efficiency of unreacted monomers and further reduces VOC residue. Heat setting eliminates the curing stress inside the coating and further improves high-temperature stability.

[0026] The preparation method in this embodiment creatively adopts a two-stage curing process. The first stage of pre-curing prioritizes the initial cross-linking of the coating surface and prism edges, fixing the microstructure of the prism and reducing structural deformation in the subsequent main curing stage. At the same time, low-intensity irradiation avoids over-curing of the surface, reserving space for the flow of deep resin. The second stage of main curing is normal curing, realizing the formation of the prism film. The two curing processes ensure the integrity of the prism structure and production efficiency. The entire preparation method has few process steps, is simple to operate, does not require the introduction of complex equipment or procedures, and is easy to implement.

[0027] In one specific embodiment, in step S2, the mold surface is provided with periodically arranged microstructure units, which are composed of isosceles triangular prism structures and rectangular substrate structures arranged alternately in the same direction. This structure enables the prism film to achieve high optical performance.

[0028] An application of a prism film as described in any of the above embodiments is provided, applied in at least one automotive scenario, including dashboards, central control screens, and HUDs. When applied in automotive scenarios, it addresses the problem of interfacial reactions between the automotive prism film and the PC substrate under high-temperature conditions, leading to deformation and degradation of optical performance.

[0029] To further verify the effects of this application, the following embodiments are described: Example 1 A prism film includes a film substrate (polyethylene terephthalate) and a prism layer stacked together. The prism layer comprises the following components in parts by weight, each of which can be obtained commercially: 48 copies of the main monomer (HDDA) (Hefei Lucky Technology Industry Co., Ltd.) 32 parts of auxiliary monomer (Phenoxyethyl acrylate) (Guangdong Lankelu New Materials Co., Ltd.) Photoinitiator (TPO-L) 1.8 parts (Zhongshan Dixin Chemical Co., Ltd.) Heat stabilizer (Irganox 1010) 0.5 parts (Tianjin Jiuri New Material Co., Ltd.) VOC adsorbent (modified zeolite molecular sieve) 2.5 parts Interface passivating agent (KH-570) 1.3 parts (Nanjing Shuguang Chemical Group Co., Ltd.); The preparation method is as follows: The main monomer, auxiliary monomer, photoinitiator, heat stabilizer, VOC adsorbent, and interface passivator are added to a high-speed disperser. Pre-dispersion is performed at 1500 r / min for 10 min, followed by ultra-dispersion at 3000 r / min for 40 min (extending the dispersion time ensures uniform dispersion of the modified zeolite molecular sieve and avoids agglomeration affecting optical performance). The dispersed prism layer slurry is coated onto a PET release film (release force 30 g / in) using a comma-shaped doctor blade, controlling the wet film thickness to 55 μm (thickening the wet film ensures a 30 μm coating thickness after curing, improving structural stability). Pre-curing is performed for 4 s under 365 nm UV and 55 mW / cm² irradiation (extending the pre-curing time strengthens initial surface cross-linking and fixes the prism structure). Then, primary curing is performed for 12 s under 395 nm UV and 110 mW / cm² irradiation (increasing the primary curing irradiation intensity and time ensures complete deep cross-linking of the coating). The PET is then peeled off. After the release film is formed, it is first vacuum dried at 65℃ for 3 hours (increasing the drying temperature and extending the drying time to more fully remove unreacted monomers), and then transferred to an 80℃ hot air oven for 1 hour of heat setting (adding a heat setting step to eliminate internal curing stress in the coating and further improve high temperature stability), finally obtaining a high heat-resistant prism film.

[0030] In the preparation method, the dispersed prism layer slurry is coated onto a PET release film using a comma-shaped doctor blade. A prism structure is then formed on the prism layer coating using a mold, followed by UV curing. The mold structure diagram is shown below. Figure 1 As shown, the mold is composed of alternating isosceles triangular prisms and rectangular bases, with a repeating unit of "54 + 46" period; Figure 1 The apex of the triangle is marked, indicating that the angle accuracy must be ensured to guarantee the optical performance of the prism film after extrusion or imprinting (such as total internal reflection and light focusing effect). The mold is a key tooling to realize the optical function of the prism film by precisely machining and replicating the periodic prism structure. The surface material of the mold is precision electroplated copper with a copper layer thickness of 260 μm and a copper hardness of 200 HB.

[0031] Example 2 Basically the same as in Example 1, except that the prism layer comprises the following components in parts by weight: 52 units of the main monomer (HDDA) 26 parts of auxiliary monomer (Phenoxyethyl acrylate) 1.5 parts of photoinitiator (TPO-L) Heat stabilizer (Irganox 1010) 0.3 parts VOC adsorbent (modified zeolite molecular sieve) 3.5 parts 0.9 parts of interface passivating agent (KH-570).

[0032] Its preparation method is as follows: The main monomer, auxiliary monomer, photoinitiator, heat stabilizer, VOC adsorbent, and interface passivator were added to a planetary disperser, along with 0.1 parts of defoamer (a low-VOC polyether-modified silicone oil defoamer was selected). The mixture was dispersed at 2000 rpm for 35 minutes. A microgravure coating method (which provides more uniform coating and reduces local thickness variations compared to a comma-type doctor blade) was used to coat the slurry onto a PET release film (release force 25 g / in), with a wet film thickness controlled at 50 μm. The pre-curing stage used 365 nm UV, 50 mW / cm² irradiation, and 3 s; the main curing stage used 395 nm UV, 100 mW / cm² irradiation, and 10 s (maintaining standard curing parameters to ensure curing efficiency). After peeling off the release film, the mixture was first vacuum-dried at 60℃ for 2.5 h (extending the vacuum drying time), and then transferred to a low-temperature vacuum environment (40℃) with a vacuum degree of -0.095 MPa for 4 h. Secondary drying (with an added low-temperature secondary drying step to gently remove residual small molecules and avoid the generation of new VOCs due to high temperatures) ultimately yields a low-VOC, environmentally friendly prism film.

[0033] Example 3 Basically the same as in Example 1, except that the prism layer comprises the following components in parts by weight: 55 units of primary monomer (HDDA) 23 parts of auxiliary monomer (Phenoxyethyl acrylate) 1.6 parts of photoinitiator (TPO-L) Heat stabilizer (Irganox 1010) 0.3 parts VOC adsorbent (modified zeolite molecular sieve) 1.8 parts 0.7 parts of interface passivating agent (KH-570); Its preparation method is as follows: The main monomer, auxiliary monomer, photoinitiator, heat stabilizer, VOC adsorbent, and interface passivator were mixed and ultra-dispersed for 30 min, and then coated onto a PET release film with a wet film thickness of 50 μm. Pre-curing was then performed for 3 s at 365 nm UV and 50 mW / cm² to complete the initial cross-linking, followed by 10 s of primary curing at 395 nm UV and 100 mW / cm² to ensure deep curing. After peeling, the film was vacuum dried at 60 °C for 2 h to obtain a high-optical-performance prism film.

[0034] Example 4 Basically the same as in Example 1, except that the prism layer comprises the following components in parts by weight: 55 units of primary monomer (HDDA) 25 parts of auxiliary monomer (Phenoxyethyl acrylate) 1.5 parts of photoinitiator (TPO-L) Heat stabilizer (Irganox 1010) 0.4 parts VOC adsorbent (modified zeolite molecular sieve) 2.7 parts 0.8 parts of interface passivating agent (KH-570); The preparation method is as follows: each component is added to a high-speed disperser and ultra-dispersed at 2500 r / min for 30 min, while controlling the material temperature to be <40℃ during dispersion; the components are coated onto a PET release film using a comma-shaped doctor blade, with a wet film thickness of 50 μm and a coating speed of 15 m / min; pre-curing is performed at 365 nm UV, 50 mW / cm², for 3 s, followed by main curing at 395 nm UV, 100 mW / cm², for 10 s; after peeling, the film is vacuum dried at 60℃ for 2 h, and the thickness is measured online after drying to obtain a prism film with balanced performance.

[0035] The prism films from Examples 1-4 were subjected to performance testing at 105°C for 120 hours. (1) Adhesion to substrate (cross-cut test): Grade 0: no peeling, Grade 1: less than 5% peeling, Grade 2: 5~15% peeling, Grade 3: 15~35% peeling, Grade 4: 35~65% peeling, Grade 5: more than 65% peeling; (2) VOC emission (Tenax tube adsorption-GCMS method); (3) Brightness gain (compared to bare light source); The test results are shown in Table 1: Table 1 Performance Test Table

[0036] It should be noted that conventional prism films use PET, and the prism layer uses an acrylic ester system (HDDA+PEA) as the main substrate, employing roller-type UV curing and imprinting, suitable for continuous production at machine speeds of 5-20 m / min. As shown in Table 1, the prism film obtained using the raw materials and preparation method of this application exhibits strong adhesion to the substrate, low VOC emissions, and high optical performance. In other words, compared to existing technologies, the prism film of this application achieves significant improvements in high-temperature stability, VOC control, and optical performance, and meets the segmented needs of different display scenarios through differentiated design. Furthermore, through differentiated designs of high heat resistance, low VOC, high optical performance, and balanced performance, the application boundaries of the product in different automotive scenarios such as dashboards, central control screens, and HUDs are clearly defined, demonstrating strong applicability.

[0037] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. A prism film, comprising a substrate layer and a prism layer disposed on the surface of the substrate layer, characterized in that: The prism layer comprises the following components in parts by weight: Bifunctional aliphatic acrylate monomer: 45~55 parts; Monofunctional acrylate monomers containing benzene rings: 28-35 parts; Heat stabilizer: 0.3~0.8 parts; VOC adsorbent: 2.5~4 parts; Interface passivating agent: 0.8~1.2 parts; Photoinitiator: 1.5~1.8 parts.

2. The prism film according to claim 1, characterized in that: The VOC adsorbent is a modified zeolite molecular sieve, and the modification method of the modified zeolite molecular sieve is as follows: Pretreatment of zeolite molecular sieves; The modifier, anhydrous ethanol, and pretreated zeolite molecular sieve were mixed and stirred to obtain a mixture. The mixture was subjected to a process to remove unreacted modifiers, followed by drying to obtain modified zeolite molecular sieves.

3. The prism film according to claim 2, characterized in that: The modifier is γ-aminopropyltriethoxysilane, and the modifier, anhydrous ethanol and pretreated zeolite molecular sieve are mixed in the following mass ratio: pretreated zeolite molecular sieve: γ-aminopropyltriethoxysilane: anhydrous ethanol = (90~110): (4~6): (190~210).

4. A prism film according to claim 1 or 2, characterized in that: The bifunctional aliphatic acrylate monomer is hexanediol diacrylate; the monofunctional acrylate monomer containing a benzene ring is phenoxyethyl acrylate.

5. A method for preparing a prism film as described in any one of claims 1-4, characterized in that: Includes the following steps: S1: A prism layer slurry is formed by mixing a difunctional aliphatic acrylate monomer, a monofunctional acrylate monomer containing a benzene ring, a heat stabilizer, a VOC adsorbent, an interface passivator, and a photoinitiator in proportion to weight. S2: The prism layer slurry is coated onto the PET release film to obtain the prism layer coating, and the prism structure is formed on the prism layer coating by a mold; S3: UV pre-curing of prism layer coating: UV wavelength 360~370nm, irradiation intensity 40~60mW / cm², time 2~4s; S4: Perform UV curing on the prism layer coating: UV wavelength 390~400nm, irradiation intensity 90~130mW / cm², time 8~12s; S5: Peel off the prism layer coating from the PET release film, perform pretreatment, and then laminate it with the substrate to obtain the prism film.

6. The method for preparing a prism film according to claim 5, characterized in that: In step S1, a high-speed disperser is used to mix the components. The mixing of the high-speed disperser includes two stages: premixing and main mixing. The speed and time of the high-speed disperser in the premixing stage are both less than those in the main mixing stage.

7. The method for preparing a prism film according to claim 5, characterized in that: In step S2, the mold surface is provided with periodically arranged microstructure units, which are composed of isosceles triangular prism structures and rectangular base structures arranged alternately in the same direction.

8. A method for preparing a prism film according to claim 5, characterized in that: The pretreatment in step S5 includes vacuum drying and heat setting of the prism layer coating after the PET release film has been peeled off. The heat setting is to set the coating in a hot air oven at 75℃~85℃ for 0.5h~1.5h.

9. An application of a prism film as described in any one of claims 1-4, characterized in that: It can be applied to at least one in-vehicle scenario, such as the dashboard, central control screen, or HUD.

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