Epoxy resin composition, packaging film glue solution composition and packaging film

Abstract

The invention provides an epoxy resin composition, a packaging film glue solution composition and a packaging film, and belongs to the technical field of epoxy resin materials, the epoxy resin composition comprises, by weight, 10-20 parts of UV resin; 10-30 parts by weight of a non-flexible epoxy resin; 1-10 parts by weight of flexible epoxy resin; 1-15 parts by weight of a reactive diluent; 10-40 parts by weight of a curing agent; 0.5-2 parts by weight of a curing accelerator; 10-20 parts by weight of a light diffusion agent; and 0.01-1 part by weight of an initiator. The packaging adhesive film provided by the invention has the advantages of low warpage, alcohol soaking resistance, no softening and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of epoxy resin materials, and in particular relates to an epoxy resin composition, an encapsulating film glue composition and an encapsulating film. Background Art

[0002] Mini LED direct display screens use 50μm LED chips as display pixels, which are the basic units of image display. Their advantages lie in inheriting the high efficiency, high brightness, high reliability, and fast response time of inorganic LEDs, while also being self-luminous and requiring no backlight. They are small, thin, and easily energy-efficient. Traditional Mini LED direct display screen packaging technology uses two-component epoxy resin molding glue for molding. This process is cumbersome, requiring the addition of diffusion powder to mix the glue before packaging. CN109251723A discloses a molding high-refractive-dissipation LED packaging silicone, comprising component A and component B, with a weight ratio of component A to component B of 3:1. Component A comprises 50-60 parts methylphenyl vinyl silicone resin, 10-15 parts vinyl silicone oil, 20-40 parts hydrogen-containing small molecules, 5-10 parts chain extender, and 0.5-1 part inhibitor. 0, component B includes 75-85 vinyl silicone oil, 10-20 methylphenyl vinyl silicone resin, 5-10 adhesive, and 0.5-1.5 catalyst; the resulting Molding high-refractive index LED encapsulation silicone has the characteristics of high brightness, high refractive index, and is suitable for rapid curing in the fast stage of the Molding process. The preparation process is simple and easy to mass produce, making it suitable for LED encapsulation silicone; however, the molding process needs to maintain high temperature and high pressure for 2-3 hours to ensure that the molding glue is cured and fixed. The process is time-consuming, and the product yield is low, making rework difficult.

[0003] In recent years, the packaging film for Mini LED screens has gradually replaced the two-component epoxy resin molding glue. This process takes a short time, is simple to process, and has a high yield rate. The packaging film only needs to be rolled or molded. After lamination, it is subjected to high-pressure degassing in batches, and finally cured to complete the Mini LED screen packaging process. CN116622320A discloses a Mini LED screen packaging film, a preparation method, and a packaging method, comprising a first release film, a second release film, and a semi-cured film layer arranged between the first release film and the second release film; the semi-cured film layer is composed of the following components in parts by weight: 100 parts of epoxy resin, 5-15 parts of UV resin, 120-200 parts of silicon powder, 5-15 parts of active diluent, 0.1-1 part of solvent-free carbon black slurry, 0-5 parts of fumed silica, 80-90 parts of anhydride curing agent, 0.1-1 part of anhydride curing accelerator, and 0.01-0.1 part of photoinitiator. This technical solution pre-forms the glue into a packaging film material, and then uses a roller pressing method to package the packaging film material on the display panel to form a direct display screen. This can improve the efficiency and yield of packaging, but it is prone to the problem of low filling rate.

[0004] As Mini LED screens and chip heights increase, the thickness and size of existing encapsulation films also increase, leading to new problems. After thermal curing, the film's poor toughness and high thermal stress cause significant warping of the Mini LED screen. When spliced ​​into larger displays, the large panel becomes uneven and displays unevenly. Furthermore, a layer of optically clear adhesive (OCA) must be applied to the film surface. Rework requires soaking in alcohol, but alcohol softens the encapsulation film, leaving marks.

[0005] Therefore, it is necessary to provide a packaging film with low warpage and resistance to alcohol immersion without softening to meet application requirements. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide an epoxy resin composition, an encapsulating film adhesive composition, and an encapsulating film. The encapsulating film provided by the present invention has the advantages of low warpage and resistance to alcohol immersion without softening.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an epoxy resin composition, comprising, in parts by weight:

[0009] 10-20 parts by weight of UV resin;

[0010]

[0011] In the epoxy resin composition provided by the present invention, UV resin is used as both a film-forming material and a toughening agent. It can form an interpenetrating network structure with the non-flexible epoxy resin, reduce the crosslinking degree of the epoxy resin, and improve the toughness of the formed film; at the same time, the flexible epoxy resin and active diluent introduced can further reduce the crosslinking degree of the film formed after curing, reduce its hardness, and increase its toughness; and the introduction of the light diffuser can reduce the internal stress of the film; therefore, the composition provided by the present invention can fully release the thermal stress of the film formed by curing the composition through the mutual cooperation of the various components after thermal curing, thereby ensuring that the film can maintain low warping when applied to larger-sized Mini LED display screen packaging (higher thickness and larger length and width), and the film's alcohol immersion resistance will not decrease, thereby meeting the application requirements of the film for MiniLED panels.

[0012] In the present invention, the UV resin 10-20 parts by weight can be 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, etc., the non-flexible epoxy resin 10-30 parts by weight can be 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, 25 parts by weight, 3 parts by weight, etc., the flexible epoxy resin 1-10 parts by weight can be 1 part by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, etc., the reactive diluent 1-15 parts by weight can be 1 part by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 15 parts by weight, etc., the curing agent 10-40 parts by weight can be 10 parts by weight, 15 The curing accelerator 0.5-2 parts by weight can be 0.5 parts by weight, 0.6 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, etc. The light diffuser 10-20 parts by weight can be 10 parts by weight, 12 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, etc. The initiator 0.01-1 part by weight can be 0.01 parts by weight, 0.02 parts by weight, 0.05 parts by weight, 0.08 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, etc.

[0013] Preferably, the UV resin includes any one of silicone-modified polyurethane acrylate resin, modified polybutadiene, polyurethane-modified acrylate resin or epoxy acrylate resin, or a combination of at least two thereof.

[0014] Preferably, the functionality of the silicone-modified polyurethane acrylate resin is 4-6, for example, 4, 5, 6, etc., the acid value is less than 2 mgKOH / g, for example, 1.9 mgKOH / g, 1.8 mgKOH / g, 1.6 mgKOH / g, 1.5 mgKOH / g, 1.4 mgKOH / g, 1.2 mgKOH / g, 1 mgKOH / g, etc., and the viscosity at 30°C is 12000-22000 cps, for example, 12000 cps, 15000 cps, 16000 cps, 18000 cps, 20000 cps, 22000 cps, etc.

[0015] Preferably, the modified polybutadiene has a number average molecular weight of 3000-6000, for example, 3000, 3500, 4000, 4500, 5000, 5500, 6000, etc., a functionality of 2-4, for example, 2, 3, 4, etc., and a viscosity at 25° C. of 6500-18000 cps, for example, 6500 cps, 7000 cps, 8000 cps, 9000 cps, 10000 cps, 12000 cps, 14000 cps, 15000 cps, 16000 cps, 17000 cps, 18000 cps, etc.

[0016] Preferably, the polyurethane-modified acrylate resin includes an aromatic polyurethane-modified acrylate resin and / or an aliphatic polyurethane-modified acrylate resin.

[0017] Preferably, the functionality of the aromatic polyurethane modified acrylate resin is 2-3, for example, 2, 3, etc., the acid value is less than 2 mgKOH / g, for example, 1.9 mgKOH / g, 1.8 mgKOH / g, 1.6 mgKOH / g, 1.5 mgKOH / g, 1.4 mgKOH / g, 1.2 mgKOH / g, 1 mgKOH / g, etc., and the viscosity at 60°C is 30,000-60,000 cps, for example, 30,000 cps, 35,000 cps, 40,000 cps, 45,000 cps, 50,000 cps, 55,000 cps, 60,000 cps, etc.

[0018] Preferably, the functionality of the aliphatic polyurethane modified acrylate resin is 2-4, for example, 2, 3, 4, etc., the acid value is less than 2 mgKOH / g, for example, 1.9 mgKOH / g, 1.8 mgKOH / g, 1.6 mgKOH / g, 1.5 mgKOH / g, 1.4 mgKOH / g, 1.2 mgKOH / g, 1 mgKOH / g, etc., and the viscosity at 60°C is 9000-15000 cps, for example, 9000 cps, 10000 cps, 11000 cps, 12000 cps, 13000 cps, 14000 cps, 15000 cps, etc.

[0019] Preferably, the functionality of the epoxy acrylate resin is 2-3, for example, 2, 3, etc., the acid value is less than 5 mgKOH / g, for example, 4.5 mgKOH / g, 4.2 mgKOH / g, 4 mgKOH / g, 3.5 mgKOH / g, 3 mgKOH / g, 2.5 mgKOH / g, 2 mgKOH / g, etc., and the viscosity at 60°C is 500-700 cps, for example, 500 cps, 550 cps, 600 cps, 650 cps, 700 cps, etc.

[0020] Preferably, the non-flexible epoxy resin includes any one of bisphenol A epoxy resin, bisphenol F epoxy resin, alicyclic epoxy resin or biphenyl epoxy resin, or a combination of at least two thereof.

[0021] Preferably, the non-flexible epoxy resin includes solid non-flexible epoxy resin and liquid non-flexible epoxy resin.

[0022] Preferably, the mass ratio of the solid non-flexible epoxy resin to the liquid non-flexible epoxy resin is 1:(3-5), for example, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0023] In the present invention, by simultaneously introducing a specific mass ratio of solid epoxy resin and liquid epoxy resin, the two work together to effectively improve the resulting film's surface alcohol-wipe resistance. Furthermore, in combination with a flexible epoxy resin and a reactive diluent, the thermal stress within the film is fully released during the thermal curing process, allowing the resulting film to maintain relatively low warpage (less than 5mm), meeting the requirements for Mini LED packaging films. If only a single liquid, non-flexible epoxy resin is used, the resulting cured film will exhibit low warpage but poor alcohol-wipe resistance.

[0024] Preferably, the solid non-flexible epoxy resin has an epoxy equivalent of 300-500 g / eq, for example, 300 g / eq, 350 g / eq, 400 g / eq, 450 g / eq, 500 g / eq, etc., and a softening point of 60-80°C, for example, 60°C, 62°C, 65°C, 68°C, 70°C, 72°C, 75°C, 78°C, 80°C, etc.

[0025] Preferably, the epoxy equivalent of the liquid non-flexible epoxy resin is 100-300 g / eq, for example, 100 g / eq, 150 g / eq, 200 g / eq, 250 g / eq, 300 g / eq, etc., and the viscosity at 25°C is 5000-10000 mPa·s, for example, 5000 mPa·s, 6000 mPa·s, 7000 mPa·s, 8000 mPa·s, 9000 mPa·s, 10000 mPa·s, etc.

[0026] Preferably, the flexible epoxy resin includes any one or a combination of at least two of polyurethane-modified epoxy resin, polyether-modified epoxy resin, silicone-modified epoxy resin or dimer acid-modified epoxy resin; more preferably, the flexible epoxy resin is selected from polyether-modified epoxy resin.

[0027] Preferably, the polyurethane modified epoxy resin has an epoxy equivalent of 250-300 g / eq, for example, 250 g / eq, 260 g / eq, 270 g / eq, 280 g / eq, 300 g / eq, etc.; the viscosity at 60°C is 2000-7000 cps, for example, 2000 cps, 2500 cps, 3000 cps, 3500 cps, 4000 cps, 4500 cps, 5000 cps, 5500 cps, 6000 cps, 6500 cps, 7000 cps, etc.; and the volatile matter is less than 0.1%, for example, 0.19%, 0.08%, 0.07%, 0.05%, etc.

[0028] Preferably, the epoxy equivalent of the polyether modified epoxy resin is 305-410 g / eq, for example, 305 g / eq, 310 g / eq, 320 g / eq, 330 g / eq, 340 g / eq, 350 g / eq, 370 g / eq, 380 g / eq, 400 g / eq, 410 g / eq, etc., and the viscosity at 25°C is 3000-8000 cps, for example, 3000 cps, 3500 cps, 4000 cps, 4500 cps, 5000 cps, 5500 cps, 6000 cps, 6500 cps, 7000 cps, 7500 cps, 8000 cps, etc.

[0029] Preferably, the epoxy equivalent of the silicone-modified epoxy resin is 180-200 g / eq, for example, 180 g / eq, 185 g / eq, 190 g / eq, 195 g / eq, 200 g / eq, etc., and the viscosity at 25°C is 500-1500 cps, for example, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps, 1000 cps, 1100 cps, 1200 cps, 1300 cps, 1400 cps, 1500 cps, etc.

[0030] Preferably, the epoxy equivalent of the dimer acid-modified epoxy resin is 250-500 g / eq, for example, 250 g / eq, 300 g / eq, 350 g / eq, 400 g / eq, 450 g / eq, 500 g / eq, etc., and the viscosity at 25°C is 500-6000 cps, for example, 500 cps, 1000 cps, 1500 cps, 2000 cps, 2500 cps, 3000 cps, 3500 cps, 4000 cps, 4500 cps, 5000 cps, 5500, 6000 cps, etc.

[0031] Preferably, the reactive diluent includes any one of polyester polyol, polyether polyol, polycarbonate polyol or glycidyl ether, or a combination of at least two thereof. More preferably, the reactive diluent is polycarbonate polyol.

[0032] The present invention preferably uses polycarbonate polyol as the active diluent, which can further reduce the warpage of the final encapsulation film and increase its resistance to alcohol immersion without softening.

[0033] Preferably, the hydroxyl value of the polyester polyol, polyether polyol and polycarbonate polyol is independently selected from 50-300 mgKOH / g, for example, 50 mgKOH / g, 100 mgKOH / g, 150 mgKOH / g, 200 mgKOH / g, 250 mgKOH / g, 300 mgKOH / g, etc., and the viscosity at 25°C is independently selected from 200-1000 cps, for example, 200 cps, 300 cps, 400 cps, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps, 1000 cps, etc.

[0034] Preferably, the glycidyl ether includes monofunctional glycidyl ether and difunctional glycidyl ether, and the monofunctional glycidyl ether preferably has an epoxy equivalent of 150-300 g / eq, such as 150 g / eq, 180 g / eq, 200 g / eq, 250 g / eq, 300 g / eq, etc., and a viscosity at 25°C of 2-50 cps, such as 2 cps, 10 cps, 15 cps, 20 cps, 25 cps, 30 cps, 35 cps, 40 cps, 45 cps, 50 cps, etc., and preferably The epoxy equivalent of the difunctional glycidyl ether is 100-300 g / eq, for example, 100 g / eq, 120 g / eq, 150 g / eq, 180 g / eq, 200 g / eq, 250 g / eq, 300 g / eq, etc., and the viscosity at 25° C. is 10-50 cps, for example, 10 cps, 12 cps, 15 cps, 18 cps, 20 cps, 22 cps, 25 cps, 28 cps, 30 cps, 35 cps, 40 cps, 45 cps, 50 cps, etc.

[0035] Preferably, the mass ratio of the flexible epoxy resin to the reactive diluent is 1:(1-2), for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, etc. When the mass ratio of the flexible epoxy resin to the reactive diluent of the present invention is preferably within the above range, warpage can be further reduced.

[0036] Preferably, the curing agent includes any one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride or nadic anhydride, or a combination of at least two thereof.

[0037] Preferably, the curing accelerator includes any one of a Lewis base accelerator, a boron trichloride dimethyloctylamine complex accelerator, or an organophosphorus accelerator, or a combination of at least two thereof.

[0038] Preferably, the light diffuser includes any one of silicone microspheres, acrylic light diffuser or polystyrene, or a combination of at least two of them.

[0039] Preferably, the particle size of the light diffusing agent is 1-3 μm, for example, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, etc.

[0040] Preferably, the initiator includes any one or a combination of at least two of benzoin and its derivatives, benzil and its derivatives, dialkoxyacetophenone, α-hydroxyalkylphenone, α-aminoalkylphenone or acylphosphine oxide.

[0041] The epoxy resin composition provided by the present invention can solve the problem that the existing Mini LED screen packaging film causes serious warping of the Mini LED screen after thermal curing due to the increase in film thickness and size as the Mini LED screen size and chip height increase. The film obtained by curing the epoxy resin composition provided by the present invention has the advantage of low warping; at the same time, it has the advantage of being resistant to alcohol immersion and not softening, and can be well used in Mini LED packaging.

[0042] The present invention also provides a method for preparing the epoxy resin composition according to the first aspect, the preparation method comprising:

[0043] The epoxy resin composition is obtained by mixing the UV resin, non-flexible epoxy resin, flexible epoxy resin, reactive diluent, initiator and light diffuser in a formulated amount for the first time, and then adding a curing agent and a curing accelerator for the second time.

[0044] Preferably, the first mixing method includes stirring and then grinding, and preferably, the second mixing method includes stirring under a vacuum environment.

[0045] Preferably, the preparation method comprises:

[0046] The UV resin, non-flexible epoxy resin, flexible epoxy resin, reactive diluent, initiator and light diffuser in the formulated amount are stirred in the dark for 20-30 minutes, preferably in the dark at high speed, and then ground using a grinder. Finally, a curing agent and a curing accelerator are added and stirred in a vacuum environment until bubbles disappear to obtain the epoxy resin composition.

[0047] Preferably, the epoxy resin composition can be coated to obtain a packaging film.

[0048] In a second aspect, the present invention provides an application of the epoxy resin composition as described in the first aspect in LED encapsulation adhesive, preferably in Mini LED encapsulation adhesive.

[0049] In a third aspect, the present invention provides an encapsulation film adhesive composition, comprising the epoxy resin composition described in the first aspect.

[0050] The encapsulation film glue composition provided by the present invention is reasonably matched with UV resin, epoxy resin, active diluent, flexible epoxy resin, curing agent and curing accelerator, light diffuser, etc., so that the glue film finally formed by the glue composition has a certain hydrophobic ability. During the process of soaking in polar alcohol to clean dirt, the glue film will not become soft and will not leave scratches when wiped.

[0051] At the same time, the adhesive film obtained by applying the adhesive composition provided by the present invention has reduced hardness and increased toughness. Therefore, when used for packaging of larger-sized panels, it still has extremely low warpage.

[0052] In a fourth aspect, the present invention provides an encapsulating adhesive film comprising a light release film, an adhesive film layer and a heavy release film arranged in sequence, wherein the adhesive film layer is obtained by curing the encapsulating film adhesive composition described in the third aspect or the epoxy resin composition described in the first aspect.

[0053] Preferably, the curing is UV curing, and the energy of the UV light is preferably 3000-4000 mj / cm 2 , for example 3000mj / cm 2 、3100mj / cm 2 、3200mj / cm 2 、3300mj / cm 2 、3500mj / cm 2 、3600mj / cm 2 、3800mj / cm 2 4000mj / cm 2 wait.

[0054] Preferably, the release force of the light release film is 10-15 gf / inch, for example, 10 gf / inch, 11 gf / inch, 12 gf / inch, 13 gf / inch, 14 gf / inch, 15 gf / inch, etc.; preferably, the release force of the heavy release film is 25-30 gf / inch, for example, 25 gf / inch, 26 gf / inch, 27 gf / inch, 28 gf / inch, 29 gf / inch, 30 gf / inch, etc.

[0055] In the fifth aspect, the present invention provides an application of the epoxy resin composition described in the first aspect, the group packaging film glue composition described in the third aspect, or the packaging film described in the fourth aspect in the packaging of LED direct display modules, preferably in the packaging of Mini LED direct display modules.

[0056] Preferably, the packaging method includes roll lamination or hot pressing lamination.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The present invention introduces a flexible epoxy resin, a UV resin, and a reactive diluent into the composition, thereby reducing the crosslinking degree of the adhesive film formed after curing, reducing its hardness, and increasing its toughness. This allows the adhesive film to fully release thermal stress after thermal curing, thereby ensuring that the adhesive film can maintain low warpage even when it has a large size, thereby meeting application requirements.

[0059] (2) The adhesive film formed by curing the composition provided by the present invention has a certain hydrophobicity. During the process of soaking in polar ethanol to clean dirt, the adhesive film will not become soft and will not leave scratches when wiped. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Schematic diagram of the structure of the packaging film of the present invention;

[0061] Among them: 1-light release film; 2-adhesive film layer; 3-heavy release film;

[0062] Figure 2 A photo of a Mini LED panel used for warpage testing. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0064] Unless otherwise specified, the raw materials involved in the specific embodiments of the present invention are all conventional materials in the art and can be purchased commercially.

[0065] In particular, information on some of the raw materials involved in the specific embodiments of the present invention is shown in Table 1 below:

[0066] Table 1

[0067]

[0068] Example 1

[0069] This embodiment provides an epoxy resin composition and a preparation method thereof, wherein the specific components are shown in Table 1, and the preparation method is as follows:

[0070] A solid non-flexible epoxy resin is dissolved in a liquid non-flexible epoxy resin in an oven at 120° C., and then an organosilicon-modified polyurethane acrylate resin, other UV resins, and an initiator are added to a container and stirred at 1500 r / min for 5 minutes. A light dispersant is then added and stirred and dispersed at 2000 r / min for 5 minutes. Finally, a curing agent and a curing accelerator are added to the resin solution, and the mixture is stirred and degassed for 10 minutes at a speed of 1500 r / min to obtain the epoxy resin composition.

[0071] Examples 2-12 and Comparative Examples 1-5

[0072] This embodiment or comparative example provides an epoxy resin composition. The specific components are shown in Table 2-3. The preparation method is similar to that of Example 1.

[0073] Table 2

[0074]

[0075] Table 3

[0076]

[0077] Application Example 1

[0078] This application example provides a packaging film, such as Figure 1 As shown, it includes a light release film 1, an adhesive film layer 2 and a heavy release film 3 arranged in sequence, and the preparation method is as follows:

[0079] The epoxy resin composition provided in the embodiment is coated into a film using a double-roll coater:

[0080] Coating spacing 260μm, coating speed 2m / min, UV light wavelength 365nm, UV light energy 4000mj / cm 2The release force of the light release film is 10gf / inch, the release force of the heavy release film is 25gf / inch, and the thickness of the release film is 50μm; after coating and die-cutting, a packaging film with a length of 330mm, a width of 170mm, and a thickness of 260μm is obtained.

[0081] Performance Testing

[0082] The epoxy resin compositions provided in the examples and comparative examples were used to prepare encapsulating films with reference to Application Example 1, and the performance of the encapsulating films was tested as follows:

[0083] (1) Warping test: Select a film with a length and width of 330 mm and 170 mm and a thickness of 260 μm. After removing the light release film, attach it to the Mini LED panel. The Mini LED panel is 330 mm long, 170 mm wide and 1 mm thick. Place the Mini LED panel with the film attached in a 140°C oven for curing for 2 hours, then take it out and place it on a flat table. Remove the heavy release film, press one end of the Mini LED panel, place a ruler perpendicular to the table, and then measure the warping height of one end of the Mini LED panel. Mini LED panel (manufacturer: Pengding Holdings Co., Ltd.);

[0084] (2) Alcohol resistance test: The Mini LED panel (Pengding Holdings Co., Ltd.) was baked at 100°C for 30 minutes. After cooling, a 260μm thick film was attached to the Mini LED panel. The Mini LED panel with the film attached was placed in a 140°C oven for curing for 2 hours. After cooling to room temperature, the heavy release film was removed. Alcohol was added to the surface of the film and soaked for 5 minutes. The alcohol was wiped off and the traces were observed. The film was wiped with a dust-free cloth to observe whether the film was softened or deformed. If there were traces, the film was baked at 80°C for 5 minutes to observe whether the traces disappeared.

[0085] (3)T g : Using DSC (Hitachi, DSC200) testing, the film was placed in a 140°C oven for curing for 2 h. The sample was cooled to room temperature, and a suitable mass of sample was placed in the DSC at a heating rate of 10 K / min in the temperature range of 25-220°C in a nitrogen-free atmosphere.

[0086] (4) Tensile strength and elongation at break test: A film with a length and width of 330 mm and 170 mm and a thickness of 260 μm was cured in an oven at 140°C for 2 h. After cooling to room temperature, a dumbbell-shaped test strip was obtained using a sampler (manufacturer: Xibowen hand-pressed sampler). The tensile strength was tested using a computerized peel force tester (manufacturer: Shenzhen Zhongzheng Instrument Co., Ltd.) at a stretching rate of 5 mm / min.

[0087] (5) Hardness test: The film cured in an oven at 140°C for 2 h was cut into 3*3 cm thin slices. After 8 slices were stacked, the hardness was tested using a Shore D hardness tester.

[0088] The test results are as follows:

[0089] Figure 2 A photo of a Mini LED panel used for warpage testing. Figure 2 It can be seen that the size of the Mini LED panel used for the warpage test of the present invention is relatively large, that is, the present invention still has low warpage in a larger-sized packaging structure.

[0090] Table 4

[0091]

[0092] As can be seen from the examples and performance tests, the encapsulation film obtained from the epoxy resin composition provided by the present invention has low hardness and excellent toughness, which can enable the film to fully release thermal stress after thermal curing, thereby ensuring that the film can still maintain low warpage when it has a large size. It also has a certain hydrophobicity. During the process of soaking in polar ethanol to clean dirt, the film will not soften, and even if there are slight marks, they will disappear after baking.

[0093] As can be seen from the comparison of Example 1 and Example 4, the present invention preferably uses polycarbonate polyol as a reactive diluent, which can further reduce the warpage of the film and improve the alcohol wiping resistance. As can be seen from the comparison of Example 2 and Example 3, the present invention simultaneously introduces liquid epoxy resin and solid epoxy resin into the non-flexible epoxy resin, which can improve the surface alcohol wiping resistance of the film and still have a low warpage (less than 5mm). As can be seen from the comparison of Example 1 and Examples 5-7, when the mass ratio of liquid epoxy resin and solid epoxy resin is within the preferred range of the present invention, the warpage can be as low as possible while making the film surface resistant to alcohol wiping.

[0094] From the comparison between Example 1 and Comparative Examples 1-3, it can be seen that the present invention simultaneously introduces a flexible epoxy resin and a reactive diluent into the epoxy resin composition, which can increase the mobility of the chain segments in the system and reduce the crosslinking density, thereby reducing the hardness of the film and reducing warping.

[0095] The applicant states that while the above-described embodiments illustrate the process of the present invention, the present invention is not limited to the above-described process steps, nor does it imply that the present invention must rely on the above-described process steps for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for the raw materials used, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. An epoxy resin composition, characterized in that In parts by weight, the epoxy resin composition comprises:

2. The epoxy resin composition according to claim 1, wherein The UV resin includes any one or a combination of at least two of silicone-modified polyurethane acrylate resin, modified polybutadiene, polyurethane-modified acrylate resin or epoxy acrylate resin; Preferably, the silicone-modified polyurethane acrylate resin has a functionality of 4-6, an acid value of <2 mgKOH / g, and a viscosity of 12000-22000 cps at 30°C; Preferably, the modified polybutadiene has a number average molecular weight of 3000-6000, a functionality of 2-4, and a viscosity of 6500-18000 cps at 25°C; Preferably, the polyurethane modified acrylate resin includes an aromatic polyurethane modified acrylate resin and / or an aliphatic polyurethane modified acrylate resin; Preferably, the aromatic polyurethane modified acrylate resin has a functionality of 2-3, an acid value of <2 mgKOH / g, and a viscosity of 30,000-60,000 cps at 60°C; Preferably, the functionality of the aliphatic polyurethane modified acrylate resin is 2-4, the acid value is less than 2 mgKOH / g, and the viscosity at 60°C is 9000-15000 cps; Preferably, the epoxy acrylate resin has a functionality of 2-3, an acid value of less than 5 mgKOH / g, and a viscosity of 500-700 cps at 60°C.

3. The epoxy resin composition according to claim 1 or 2, characterized in that The non-flexible epoxy resin includes any one of bisphenol A epoxy resin, bisphenol F epoxy resin, alicyclic epoxy resin or biphenyl epoxy resin, or a combination of at least two thereof; Preferably, the non-flexible epoxy resin includes a solid non-flexible epoxy resin and a liquid non-flexible epoxy resin; Preferably, the mass ratio of the solid non-flexible epoxy resin to the liquid non-flexible epoxy resin is 1:(3-5); Preferably, the solid non-flexible epoxy resin has an epoxy equivalent of 300-500 g / eq and a softening point of 60-80° C. Preferably, the epoxy equivalent of the liquid non-flexible epoxy resin is 100-300 g / eq, and the viscosity at 25° C. is 5000-10000 mPa·s.

4. The epoxy resin composition according to any one of claims 1 to 3, characterized in that The flexible epoxy resin includes any one or a combination of at least two of polyurethane-modified epoxy resin, polyether-modified epoxy resin, silicone-modified epoxy resin or dimer acid-modified epoxy resin; Preferably, the polyurethane modified epoxy resin has an epoxy equivalent of 250-300 g / eq, a viscosity of 2000-7000 cps at 60° C., and a volatile matter of less than 0.1%; Preferably, the polyether-modified epoxy resin has an epoxy equivalent of 305-410 g / eq and a viscosity of 3000-8000 cps at 25°C; Preferably, the epoxy equivalent of the silicone-modified epoxy resin is 180-200 g / eq and the viscosity at 25° C. is 500-1500 cps; Preferably, the epoxy equivalent of the dimer acid-modified epoxy resin is 250-500 g / eq, and the viscosity at 25° C. is 500-6000 cps.

5. The epoxy resin composition according to any one of claims 1 to 4, characterized in that The reactive diluent includes any one or a combination of at least two of polyester polyol, polyether polyol, polycarbonate polyol or glycidyl ether; Preferably, the hydroxyl value of the polyester polyol, polyether polyol, and polycarbonate polyol is independently selected from 50-300 mgKOH / g, and the viscosity at 25° C. is independently selected from 200-1000 cps; Preferably, the glycidyl ether includes monofunctional glycidyl ether and difunctional glycidyl ether, preferably the monofunctional glycidyl ether has an epoxy equivalent of 150-300 g / eq and a viscosity at 25°C of 2-50 cps, preferably the difunctional glycidyl ether has an epoxy equivalent of 100-300 g / eq and a viscosity at 25°C of 10-50 cps; Preferably, the mass ratio of the flexible epoxy resin to the reactive diluent is 1:(1-2).

6. The epoxy resin composition according to any one of claims 1 to 5, characterized in that The curing agent includes any one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride or nadic anhydride, or a combination of at least two thereof; Preferably, the curing accelerator includes any one or a combination of at least two of a Lewis base accelerator, a boron trichloride dimethyloctylamine complex accelerator, or an organophosphorus accelerator; Preferably, the light diffuser comprises any one of silicone microspheres, acrylic light diffuser or polystyrene, or a combination of at least two thereof; Preferably, the particle size of the light diffusing agent is 1-3 μm; Preferably, the initiator includes any one or a combination of at least two of benzoin and its derivatives, benzil and its derivatives, dialkoxyacetophenone, α-hydroxyalkylphenone, α-aminoalkylphenone or acylphosphine oxide.

7. Use of the epoxy resin composition according to any one of claims 1 to 6 in LED encapsulation adhesive, preferably in Mini LED encapsulation adhesive.

8. A packaging film glue composition, characterized in that: The epoxy resin composition comprises the epoxy resin composition according to any one of claims 1 to 6.

9. A packaging film, characterized in that: The invention comprises a light release film, an adhesive film layer and a heavy release film arranged in sequence, wherein the adhesive film layer is obtained by curing the epoxy resin composition according to any one of claims 1 to 6.

10. Use of the epoxy resin composition according to any one of claims 1 to 6, or the encapsulation film according to claim 9, in LED direct display module packaging, preferably in Mini LED direct display module packaging; Preferably, the packaging method includes roll lamination or hot pressing lamination.

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