Laminated cover plate for electronic equipment and production process of laminated cover plate

Abstract

The invention discloses a laminated cover plate for electronic equipment and a production process thereof, and relates to the technical field of glass fiber boards, the production process comprises the following steps: preheating epoxy resin DGEBA and bio-based epoxy resin to 80-90 DEG C, uniformly stirring, defoaming, adding a bio-based epoxy resin flame-retardant curing agent and dimethyl sulfoxide, carrying out heat preservation and uniform stirring, cooling to room temperature, and carrying out heat preservation and uniform stirring to obtain the laminated cover plate for the electronic equipment. Adding dipolyamine, and uniformly stirring to obtain an epoxy resin glue solution; coating two sides of glass fiber cloth with an epoxy resin glue solution, and curing at 120-160 DEG C to obtain prepregs; a plurality of prepregs are stacked, hot-pressed and compounded, and a laminated cover plate substrate is obtained; the laminated cover plate substrate is sequentially subjected to spraying, rubbing and coating process treatment, and the laminated cover plate for the electronic equipment is obtained; the coating process comprises a magnetron sputtering process of niobium oxide coating and a plasma enhanced chemical vapor deposition process of silicon dioxide coating.

Description

Technical Field

[0001] The present invention relates to the technical field of fiberglass boards, and specifically to a laminated cover plate for electronic devices and its production process. Background Art

[0002] At present, with the booming development of the electronic device industry, as a key component, the performance of the laminated cover plate for electronic devices directly affects the quality and user experience of electronic devices.

[0003] With the increasing powerful functions and expanding application scenarios of electronic devices, higher requirements are put forward for the comprehensive performance of laminated cover plates. Traditional laminated cover plates have obvious shortcomings in performance. In terms of mechanical properties, it is difficult to withstand external forces in complex environments and is prone to breakage; the flame retardant performance is also not satisfactory and cannot effectively ensure the safety of devices in dangerous situations such as fires; and environmental protection has become a key factor restricting its long-term development.

[0004] Under the background of the gradually increasing awareness of environmental protection, the demand for sustainable development in the electronic device industry is becoming more and more urgent. In the production process of traditional laminated cover plates, a large amount of non-renewable resources are often relied on. Some raw materials and solvents are not only highly toxic but also produce a high carbon footprint, which runs counter to the concept of green and environmentally friendly production. Therefore, developing the use of bio-based raw materials and adopting green and sustainable production processes to prepare laminated cover plates has become an important research direction in the industry. Bio-based raw materials are derived from renewable biomass resources and have advantages such as low toxicity and degradability, which can effectively reduce the negative impact on the environment and conform to the current environmental protection development trend. However, there are still many technical problems and challenges to be overcome in the preparation of high-performance laminated cover plates using bio-based raw materials.

[0005] Therefore, it is of great significance to invent a laminated cover plate for electronic devices prepared from bio-based raw materials. Summary of the Invention

[0006] The purpose of the present invention is to provide a laminated cover plate for electronic devices and its production process to solve the problems raised in the prior art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions: A production process of a laminated cover plate for electronic devices: includes the following steps: S1: Preheat epoxy resin DGEBA and bio-based epoxy resin to 80 - 90 °C, stir evenly, perform defoaming treatment, add bio-based epoxy resin flame retardant curing agent and dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add diamin, stir evenly to obtain epoxy resin glue; S2: Coat both sides of the fiberglass cloth with epoxy resin glue, cure at 120 - 160 °C to obtain a semi-cured sheet; stack and lay a number of semi-cured sheets, and perform hot pressing and compounding to obtain a laminated cover plate substrate; S3: Sequentially perform spraying, stamping, and coating processes on the laminated cover plate substrate to obtain a laminated cover plate for electronic devices; The coating process includes sequentially performing a magnetron sputtering process for a monocrystalline silicon layer, a magnetron sputtering process for niobium oxide coating, and a plasma-enhanced chemical vapor deposition process for silicon dioxide coating.

[0008] Furthermore, in terms of mass parts, the proportion of each component in the epoxy resin includes 85 - 90 parts of epoxy resin DGEBA, 10 - 15 parts of bio-based epoxy resin, 76 - 114 parts of bio-based epoxy resin flame retardant curing agent, 6 - 10 parts of dimethyl sulfoxide, and 0 - 23 parts of diethylenetriamine.

[0009] Furthermore, during the preparation process of the laminated cover plate substrate, the number of layers of prepreg stacking is 3 - 7 layers; the temperature of hot pressing and compounding is 160 - 180 °C, and the pressure is 2 - 5 MPa; the coating amount of the adhesive is 200 - 300 g / m 2 。

[0010] Furthermore, the magnetron sputtering process parameters for the monocrystalline silicon layer include: the target is a silicon target, the magnetron sputtering temperature is 50 - 80 °C, the power is 13 - 17 kW, the voltage is 415 - 515 V, and the thickness of the monocrystalline silicon layer is 2 - 3 nm; Furthermore, the magnetron sputtering process parameters for the niobium oxide coating include: the target is a high-purity niobium target, the substrate temperature is 200 - 205 °C, the sputtering power is 150 - 160 W, the oxygen flow rate is 20 - 30 sccm, and the coating thickness is 50 - 100 nm.

[0011] Furthermore, the plasma-enhanced chemical vapor deposition process parameters include: the precursors are silane and nitrous oxide with a flow ratio of 1:5, the radio frequency power is 100 - 120 W, the deposition pressure is 200 - 250 mTorr, the substrate temperature is 300 - 305 °C, and the coating thickness is 100 - 300 nm.

[0012] Furthermore, the preparation method of the bio-based epoxy resin includes the following steps: Step (1): Add p-coumaric acid to 1,4-dioxane, stir evenly, add isophorone diisocyanate, heat to 80 - 85 °C and react for 4 - 5 h, cool to room temperature, and perform vacuum rotary evaporation at 70 - 75 °C to obtain a polyurethane prepolymer; Step (2): Add the polyurethane prepolymer into epichlorohydrin, add tetrabutylammonium bromide, heat to 80 - 85 °C and react for 3 - 3.5 h, cool to 40 - 45 °C, add an aqueous sodium hydroxide solution, keep the temperature for reaction for 12 - 13 h, cool to room temperature, add dichloromethane to dissolve the product, filter to remove the precipitate, wash the product with deionized water, dry, filter, perform vacuum distillation, and dry under vacuum at 70 - 75 °C to obtain the bio - based epoxy resin.

[0013] Furthermore, in the preparation process of the polyurethane prepolymer, the molar ratio of p - coumaric acid to isophorone diisocyanate is 0.1:0.05; in the preparation process of the bio - based epoxy resin, the mass ratio of the polyurethane prepolymer, epichlorohydrin, and tetrabutylammonium bromide is 27.5:92.5:1.375.

[0014] Furthermore, the preparation method of the flame - retardant curing agent for the bio - based epoxy resin includes the following steps: Step (1): Add ethanolamine and paraformaldehyde into chloroform, stir evenly, add eugenol, heat to 80 - 100 °C under a nitrogen atmosphere and react for 24 h, wash the product with 1 mol / L sodium hydroxide solution and deionized water, dry, concentrate, and recrystallize with absolute ethanol to obtain the eugenol - ethanolamine benzoxazine monomer; Step (2): Add the eugenol - ethanolamine benzoxazine monomer and triethylamine into dichloromethane, stir evenly, add phenyl dichlorophosphate under ice - bath conditions, stir evenly, and react at room temperature for 30 - 32 h, wash the product with saturated sodium chloride to obtain the difunctional benzoxazine phosphate; Step (3): Under a nitrogen atmosphere, add the difunctional benzoxazine phosphate into the reaction vessel, preheat to 130 - 135 °C, add DOPO within 2 h, heat to 160 - 165 °C and react for 24 h to obtain the flame - retardant curing agent for the bio - based epoxy resin.

[0015] Furthermore, in the preparation process of the eugenol - ethanolamine benzoxazine monomer, the molar ratio of ethanolamine, paraformaldehyde, and eugenol is 0.08:0.16:0.08; in the preparation process of the difunctional benzoxazine phosphate, the molar ratio of the eugenol - ethanolamine benzoxazine monomer, triethylamine, and phenyl dichlorophosphate is 0.032:0.032:0.016; in the preparation process of the flame - retardant curing agent for the bio - based epoxy resin, the molar ratio of the difunctional benzoxazine phosphate to DOPO is 0.05:0.1.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The epoxy resin synthesized from p-coumaric acid as the raw material in the present invention contains a rigid benzene ring and a conjugated olefin structure, and forms "sacrificial bonds" through a hydrogen bond network (such as the interaction between phenolic hydroxyl groups and amino groups). When stressed, they preferentially break and absorb energy, significantly improving toughness, greatly enhancing the mechanical properties of the laminated cover plate, and endowing the laminated cover plate with a high hardness property of hardness > 3H.

[0017] 2. By replacing traditional phosphorus oxychloride with phenyl dichlorophosphate in the present invention, a phenoxy group is introduced into the structure, improving the quality of the carbon layer during the flame retardant process and reducing the release of toxic gases. In the flame retardant curing agent, DOPO derivatives and nitrogen functional groups (such as benzoxazine) release PO· free radicals and inert gases during combustion, quenching active free radicals (H·, OH·) in the gas phase. At the same time, they catalyze dehydration to form carbon in the condensed phase, forming a dense phosphorus-carbon layer to isolate oxygen and heat, further improving the flame retardancy of the laminated cover plate.

[0018] 3. Through the design of the laminated structure and the optimization of the coating process in the present invention, semi-cured sheet lamination hot pressing is utilized: after multiple layers of glass fiber cloth are impregnated with bio-based epoxy adhesive, a cross-linked network is formed by hot pressing at 160 - 180 °C. The rigid chain segments (benzene rings) and the flexible chain segments (polyurethane prepolymers) are microphase separated, achieving the balance of strength and toughness, enhancing the interlayer structure strength after hot pressing of the substrate, and increasing the heat distortion temperature; magnetron sputtering and PECVD coating: niobium oxide coating enhances the surface wear resistance through its high hardness characteristics, further enhancing the wear resistance and hardness of the laminated cover plate; silicon dioxide coating is used as an insulating layer, forming a heterostructure with niobium oxide, synergistically enhancing the corrosion resistance and dielectric properties.

[0019] 4. Using plant-derived p-coumaric acid, eugenol, etc. to replace bisphenol A reduces the carbon footprint; dimethyl sulfoxide (DMSO) is used as a green solvent to reduce the toxicity during the production process. The laminated cover plate prepared in the present invention realizes the synergistic optimization of flame retardancy, mechanical properties, and environmental protection through the molecular design of bio-based epoxy resin, the phosphorus-nitrogen synergistic flame retardant system, and the multi-functional coating process. Its core mechanisms include hydrogen bond toughening, gas-phase - condensed-phase dual-effect flame retardancy, and heterostructure interface enhancement, providing an innovative solution for the encapsulation of high-performance electronic devices. Detailed implementation manners

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] In the following examples, the dimer amine model: Priamine™ 1074; the epoxy value of epoxy resin DGEBA: 0.51, the epoxy equivalent weight: 196.1 g / eq; the rest of the raw materials are all commercially available.

[0022] A preparation method of bio-based epoxy resin, comprising the following steps: Step (1): Add 0.1 mol of p-coumaric acid to 1,4-dioxane, stir evenly, add 0.05 mol of isophorone diisocyanate, heat to 80 °C and react for 4 h, cool to room temperature, and perform rotary evaporation under vacuum at 70 °C to obtain a polyurethane prepolymer; Step (2): Add 27.5 g of the polyurethane prepolymer to 92.5 g of epichlorohydrin, add 1.375 g of tetrabutylammonium bromide, heat to 80 °C and react for 3 h, cool to 40 °C, add an aqueous sodium hydroxide solution, keep the temperature and react for 12 h, cool to room temperature, add dichloromethane to dissolve the product, filter to remove the precipitate, wash the product with deionized water, dry, filter, perform vacuum distillation, and dry under vacuum at 70 °C to obtain bio-based epoxy resin.

[0023] A preparation method of a bio-based epoxy resin flame retardant curing agent, comprising the following steps: Step (1): Add 0.08 mol of ethanolamine and 0.16 mol of paraformaldehyde to chloroform, stir evenly, add 0.08 mol of eugenol, and under a nitrogen atmosphere, heat to 80 °C and react for 24 h. Wash the product with 1 mol / L sodium hydroxide solution and deionized water, dry, concentrate, and recrystallize with absolute ethanol to obtain eugenol-ethanolamine benzoxazine monomer; Step (2): Add 0.032 mol of eugenol-ethanolamine benzoxazine monomer and 0.032 mol of triethylamine to dichloromethane, stir evenly, add 0.016 mol of phenyl dichlorophosphate under ice bath conditions, stir evenly, and react at room temperature for 30 h. Wash the product with saturated sodium chloride to obtain a difunctional benzoxazine phosphate; Step (3): Under a nitrogen atmosphere, add 0.05 mol of the difunctional benzoxazine phosphate to a reaction vessel, preheat to 130 °C, add 0.1 mol of DOPO within 2 h, and heat to 160 °C and react for 24 h to obtain a bio-based epoxy resin flame retardant curing agent.

[0024] Example 1: A production process of a laminated cover plate for an electronic device: S1: Preheat 90 parts of epoxy resin DGEBA and 10 parts of bio-based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 76 parts of bio-based epoxy resin flame retardant curing agent and 6 parts of dimethyl sulfoxide, keep the temperature and stir evenly, cool to room temperature, add 23 parts of dimer amine, and stir evenly to obtain an epoxy resin adhesive; S2: Coat both sides of the fiberglass cloth with epoxy resin sizing, cure at 120 - 160 °C to obtain a prepreg; stack several prepregs and perform hot pressing and lamination to obtain a laminated cover board substrate; S3: Perform spraying, embossing, and coating processes on the laminated cover board substrate in sequence to obtain a laminated cover board for electronic devices; The coating process includes a magnetron sputtering process for a single-crystalline silicon layer, a magnetron sputtering process for niobium oxide coating, and a plasma-enhanced chemical vapor deposition process for silicon dioxide coating in sequence.

[0025] During the preparation process of the laminated cover board substrate, the number of prepregs stacked is 3 layers; the temperature of the hot pressing and lamination is 160 °C, the pressure is 2 Pa; the sizing coating amount is 200 g / m 2 .

[0026] The magnetron sputtering process parameters for the single-crystalline silicon layer include: the target is a silicon target, the magnetron sputtering temperature is 50 °C, the power is 15 kW, the voltage is 465 V, and the thickness of the single-crystalline silicon layer is 3 nm; The magnetron sputtering process parameters for the niobium oxide coating include: the target is a high-purity niobium target, the substrate temperature is 200 °C, the sputtering power is 150 W, the oxygen flow rate is 20 sccm, and the coating thickness is 50 nm.

[0027] The plasma-enhanced chemical vapor deposition process parameters include: the precursors are silane and nitrous oxide with a flow ratio of 1:5, the radio frequency power is 100 W, the deposition pressure is 200 mTorr, the substrate temperature is 300 °C, and the coating thickness is 100 nm.

[0028] Example 2: A production process for a laminated cover board for electronic devices: S1: Preheat 85 parts of epoxy resin DGEBA and 15 parts of bio-based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 76 parts of bio-based epoxy resin flame retardant curing agent and 6 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add 23 parts of diamin, and stir evenly to obtain epoxy resin sizing; S2: Coat both sides of the fiberglass cloth with epoxy resin sizing, cure at 120 - 160 °C to obtain a prepreg; stack several prepregs and perform hot pressing and lamination to obtain a laminated cover board substrate; S3: Perform spraying, embossing, and coating processes on the laminated cover board substrate in sequence to obtain a laminated cover board for electronic devices; The coating process includes a magnetron sputtering process for a single-crystalline silicon layer, a magnetron sputtering process for niobium oxide coating, and a plasma-enhanced chemical vapor deposition process for silicon dioxide coating in sequence.

[0029] During the preparation of the laminated cover plate substrate, the number of prepreg layers is 3; the temperature of the hot pressing and compounding is 160 °C, the pressure is 2 Pa; the amount of glue solution coating is 200 g / m 2 .

[0030] The magnetron sputtering process parameters of the single crystal silicon layer include: the target is a silicon target, the magnetron sputtering temperature is 50 °C, the power is 15 kW, the voltage is 465 V, and the thickness of the single crystal silicon layer is 3 nm; The magnetron sputtering process parameters of the niobium oxide coating include: the target is a high-purity niobium target, the substrate temperature is 200 °C, the sputtering power is 150 W, the oxygen flow rate is 20 sccm, and the coating thickness is 50 nm.

[0031] The plasma-enhanced chemical vapor deposition process parameters include: the precursors are silane and nitrous oxide with a flow ratio of 1:5, the radio frequency power is 100 W, the deposition pressure is 200 mTorr, the substrate temperature is 300 °C, and the coating thickness is 100 nm.

[0032] Example 3: A production process of a laminated cover plate for an electronic device: S1: Preheat 85 parts of epoxy resin DGEBA and 15 parts of bio-based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 92 parts of bio-based epoxy resin flame retardant curing agent and 6 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add 12 parts of diamin, stir evenly to obtain an epoxy resin glue solution; S2: Coat the two sides of the glass fiber cloth with the epoxy resin glue solution and cure at 120 - 160 °C to obtain a prepreg; Stack several prepregs and perform hot pressing and compounding to obtain a laminated cover plate substrate; S3: Perform spraying, embossing, and coating process treatments on the laminated cover plate substrate in sequence to obtain a laminated cover plate for an electronic device; The coating process includes performing magnetron sputtering process of a single crystal silicon layer, magnetron sputtering process of a niobium oxide coating, and plasma-enhanced chemical vapor deposition process of a silicon dioxide coating in sequence.

[0033] During the preparation of the laminated cover plate substrate, the number of prepreg layers is 3; the temperature of the hot pressing and compounding is 160 °C, the pressure is 2 Pa; the amount of glue solution coating is 200 g / m 2 .

[0034] The magnetron sputtering process parameters of the single crystal silicon layer include: the target is a silicon target, the magnetron sputtering temperature is 50 °C, the power is 15 kW, the voltage is 465 V, and the thickness of the single crystal silicon layer is 3 nm; The magnetron sputtering process parameters of the niobium oxide coating include: the target is a high-purity niobium target, the substrate temperature is 200 °C, the sputtering power is 150 W, the oxygen flow rate is 20 sccm, and the coating thickness is 50 nm.

[0035] The process parameters of the plasma enhanced chemical vapor deposition include: the precursors are silane and nitrous oxide with a flow ratio of 1:5, the radio frequency power is 100 W, the deposition pressure is 200 mTorr, the substrate temperature is 300 °C, and the coating thickness is 100 nm.

[0036] Example 4: A production process of a laminated cover plate for an electronic device: S1: Preheat 85 parts of epoxy resin DGEBA and 15 parts of bio-based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 114 parts of bio-based epoxy resin flame retardant curing agent and 10 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, and stir evenly to obtain an epoxy resin adhesive solution; S2: Coat both sides of the fiberglass cloth with the epoxy resin adhesive solution and cure at 120 - 160 °C to obtain a semi-cured sheet; stack several semi-cured sheets and perform hot press lamination to obtain a laminated cover plate substrate; S3: Perform spraying, embossing, and coating processes on the laminated cover plate substrate in sequence to obtain a laminated cover plate for an electronic device; The coating process includes a magnetron sputtering process for a single crystal silicon layer, a magnetron sputtering process for a niobium oxide coating, and a plasma enhanced chemical vapor deposition process for a silicon dioxide coating in sequence.

[0037] During the preparation process of the laminated cover plate substrate, the number of layers of the stacked semi-cured sheets is 3; the temperature of the hot press lamination is 160 °C, the pressure is 2 Pa; the coating amount of the adhesive solution is 200 g / m 2 。

[0038] The process parameters of the magnetron sputtering process for the single crystal silicon layer include: the target is a silicon target, the magnetron sputtering temperature is 50 °C, the power is 15 kW, the voltage is 465 V, and the thickness of the single crystal silicon layer is 3 nm; The process parameters of the magnetron sputtering process for the niobium oxide coating include: the target is a high-purity niobium target, the substrate temperature is 200 °C, the sputtering power is 150 W, the oxygen flow rate is 20 sccm, and the coating thickness is 50 nm.

[0039] The process parameters of the plasma enhanced chemical vapor deposition include: the precursors are silane and nitrous oxide with a flow ratio of 1:5, the radio frequency power is 100 W, the deposition pressure is 200 mTorr, the substrate temperature is 300 °C, and the coating thickness is 100 nm.

[0040] Comparative Example 1: A production process of a laminated cover plate for an electronic device: S1: Preheat 100 parts of epoxy resin DGEBA to 85 °C, stir evenly, perform defoaming treatment, add 76 parts of bio-based epoxy resin flame retardant curing agent and 6 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add 23 parts of diamine, and stir evenly to obtain an epoxy resin adhesive solution; S2: Coat both sides of the fiberglass cloth with epoxy resin adhesive solution, and cure it at 120 - 160 °C to obtain a prepreg; stack several prepregs and perform hot pressing and lamination to obtain a laminated cover board substrate; S3: Perform spraying, stamping, and coating processes on the laminated cover board substrate in sequence to obtain a laminated cover board for electronic devices; The remaining steps are the same as those in Example 1.

[0041] Comparative Example 2: A production process of a laminated cover board for electronic devices: S1: Preheat 80 parts of epoxy resin DGEBA and 20 parts of bio - based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 76 parts of bio - based epoxy resin flame - retardant curing agent and 6 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add 23 parts of diaminobutane, and stir evenly to obtain an epoxy resin adhesive solution; S2: Coat both sides of the fiberglass cloth with epoxy resin adhesive solution, and cure it at 120 - 160 °C to obtain a prepreg; stack several prepregs and perform hot pressing and lamination to obtain a laminated cover board substrate; S3: Perform spraying, stamping, and coating processes on the laminated cover board substrate in sequence to obtain a laminated cover board for electronic devices; The remaining steps are the same as those in Example 1.

[0042] Comparative Example 3: A production process of a laminated cover board for electronic devices: S1: Preheat 90 parts of epoxy resin DGEBA and 10 parts of bio - based epoxy resin to 85 °C, stir evenly, perform defoaming treatment, add 38 parts of bio - based epoxy resin flame - retardant curing agent and 6 parts of dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add 23 parts of diaminobutane, and stir evenly to obtain an epoxy resin adhesive solution; S2: Coat both sides of the fiberglass cloth with epoxy resin adhesive solution, and cure it at 120 - 160 °C to obtain a prepreg; stack several prepregs and perform hot pressing and lamination to obtain a laminated cover board substrate; S3: Perform spraying, stamping, and coating processes on the laminated cover board substrate in sequence to obtain a laminated cover board for electronic devices; The remaining steps are the same as those in Example 1.

[0043] Experiment: Conduct UL - 94 vertical burning test and limiting oxygen index (LOI) test on the laminated cover boards for electronic devices prepared in the above - mentioned examples and comparative examples.

[0044] Mechanical property test: Conduct a tensile strength test according to GB / T1447 - 2005, with the size of 250 mm×25 mm and the loading speed of 2 mm / min.

[0045] Hardness property test: Conduct pencil hardness test according to ASTM D3363.

[0046] The experimental results are shown in Table 1 below.

[0047] Table 1 Performance Test Data Sheet of Laminated Cover Plate for Electronic Devices LOI / % UL-94 Tensile strength / MPa Pencil hardness Example 1 29.8 V-0 54.4 3H Example 2 32.9 V-0 48.4 3H Example 3 33.5 V-0 74.2 4H Example 4 34.5 V-0 98.2 5H Comparative Example 1 27.8 V-0 55.0 3H Comparative Example 2 30.5 V-0 44.7 2H Comparative Example 3 25.6 V-1 23.9 1H Conclusion: The laminated cover plate for electronic devices prepared by the present invention has excellent mechanical properties and flame retardant properties.

[0048] In Comparative Example 1, only epoxy resin was used without adding bio-based epoxy resin, resulting in a decrease in flame retardant properties; in Comparative Example 2, too much bio-based epoxy resin was added, resulting in a decrease in mechanical properties; in Comparative Example 3, too little flame retardant curing agent of bio-based epoxy resin was added, resulting in a decrease in both mechanical properties and flame retardant properties.

[0049] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present invention.

Claims

1. A production process for a laminated cover plate for an electronic device, characterized in that: The following steps are involved: S1: preheat epoxy resin DGEBA and bio-based epoxy resin to 80-90°C, stir evenly, defoam, add bio-based epoxy resin flame retardant curing agent and dimethyl sulfoxide, keep warm and stir evenly, cool to room temperature, add diamine, stir evenly to obtain epoxy resin glue; S2: Coating both sides of the glass fiber cloth with epoxy resin glue and curing at 120-160°C to obtain a prepreg; stacking several prepregs and hot pressing them to obtain a laminated cover substrate; S3: performing spraying, rubbing, and coating processes on the laminated cover substrate in sequence to obtain a laminated cover for electronic equipment; The coating process includes sequentially performing a magnetron sputtering process for a single crystal silicon layer, a magnetron sputtering process for a niobium oxide coating, and a plasma enhanced chemical vapor deposition process for a silicon dioxide coating.

2. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: The proportions of the components in the epoxy resin are calculated by mass, including 85-90 parts of epoxy resin DGEBA, 10-15 parts of bio-based epoxy resin, 76-114 parts of bio-based epoxy resin flame retardant curing agent, 6-10 parts of dimethyl sulfoxide, and 0-23 parts of diamine.

3. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: During the preparation of the laminated cover plate substrate, the number of prepreg layers is 3 - 7 layers; the temperature of the hot pressing composite is 160 - 180 °C, and the pressure is 2 - 5 MPa; the amount of adhesive coating is 200 - 300 g / m 2 .

4. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: The magnetron sputtering process parameters for the single-crystalline silicon layer include: a silicon target, a magnetron sputtering temperature of 50-80°C, a power of 13-17kW, a voltage of 415-515V, and a single-crystalline silicon layer thickness of 2-3nm; the magnetron sputtering process parameters for the niobium oxide coating include: a high-purity niobium target, a substrate temperature of 200-205°C, a sputtering power of 150-160W, an oxygen flow rate of 20-30sccm, and a coating thickness of 50-100nm.

5. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: The plasma enhanced chemical vapor deposition process parameters include: precursors are silicon tetrahydride and nitrous oxide with a flow ratio of 1:5, radio frequency power is 100-120W, deposition pressure is 200-250mTorr, substrate temperature is 300-305°C, and coating thickness is 100-300nm.

6. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: The preparation method of the bio-based epoxy resin comprises the following steps: Step (1): add p-coumaric acid to 1,4-dioxane, stir evenly, add isophorone diisocyanate, heat to 80-85°C for reaction for 4-5h, cool to room temperature, and vacuum evaporate at 70-75°C to obtain a polyurethane prepolymer; Step (2): Add the polyurethane prepolymer to epichlorohydrin, add tetrabutylammonium bromide, heat to 80-85°C for reaction for 3-3.5 hours, cool to 40-45°C, add sodium hydroxide aqueous solution, keep warm for reaction for 12-13 hours, cool to room temperature, add dichloromethane to dissolve the product, filter to remove the precipitate, wash the product with deionized water, dry, filter, vacuum distill, and vacuum dry at 70-75°C to obtain a bio-based epoxy resin.

7. The production process of a laminated cover plate for an electronic device according to claim 6, characterized in that: During the preparation of the polyurethane prepolymer, the molar ratio of p-coumaric acid to isophorone diisocyanate was 0.1:0.05; during the preparation of the bio-based epoxy resin, the mass ratio of the polyurethane prepolymer to epichlorohydrin to tetrabutylammonium bromide was 27.5:92.5:1.

375.

8. The production process of a laminated cover plate for an electronic device according to claim 1, characterized in that: The preparation method of the bio-based epoxy resin flame retardant curing agent comprises the following steps: Step (1): Ethanolamine and paraformaldehyde are added to chloroform, stirred evenly, and eugenol is added. Under a nitrogen atmosphere, the mixture is heated to 80 - 100 °C and reacted for 24 h. The product is washed with 1 mol / L sodium hydroxide solution and deionized water, dried, concentrated, and recrystallized with absolute ethanol to obtain the eugenol-ethanolamine benzoxazine monomer; Step (2): The eugenol-ethanolamine benzoxazine monomer and triethylamine are added to dichloromethane, stirred evenly, phenyl dichlorophosphate is added under ice bath conditions, stirred evenly, and reacted at room temperature for 30 - 32 h. The product is washed with saturated sodium chloride to obtain the difunctional benzoxazine phosphate; Step (3): Under a nitrogen atmosphere, the difunctional benzoxazine phosphate is added to a reaction vessel, preheated to 130 - 135 °C, and DOPO is added within 2 h. Then it is heated to 160 - 165 °C and reacted for 24 h to obtain the bio-based epoxy resin flame retardant curing agent.

9. The production process of a laminated cover plate for an electronic device according to claim 8, characterized in that: During the preparation process of the eugenol-ethanolamine benzoxazine monomer, the molar ratio of ethanolamine:paraformaldehyde:eugenol is 0.08:0.16:0.08; during the preparation process of the difunctional benzoxazine phosphate, the molar ratio of eugenol-ethanolamine benzoxazine monomer:triethylamine:phenyl dichlorophosphate is 0.032:0.032:0.016; during the preparation process of the bio-based epoxy resin flame retardant curing agent, the molar ratio of difunctional benzoxazine phosphate:DOPO is 0.05:0.

1.

10. A laminated cover plate for an electronic device prepared by the production process of a laminated cover plate for an electronic device according to any one of claims 1 - 9.