Manufacturing method of 3D / 2D glass fiber mobile phone rear cover with graphical coating effect

Abstract

The invention discloses a manufacturing method of a 3D / 2D glass fiber mobile phone rear cover with a graphical coating effect, and relates to the technical field of mobile phone rear cover manufacturing, and the manufacturing method comprises the following steps: sequentially coating a release agent and a hardening liquid on a base film, screen-printing transparent gloss oil, then preparing ultraviolet curing resin, carrying out mold imprinting and ultraviolet curing to obtain a texture layer 1, and transferring the texture layer 1 to the base film; an electroplated layer 1 is formed through a magnetron sputtering machine, then patterns are offset-printed, part of the electroplated layer is selectively removed through an optical deplating solution, and the pattern effect of the precise PVD technology 1 is formed; after screen printing gloss oil protection is conducted on the surface of the PVD1 pattern, the steps of texture transfer printing and electroplating are repeated to construct a PVD2 pattern effect; and finally, screen-printing a plurality of layers of printing ink on the surface of the PVD2 pattern to cover the bottom, coating an adhesive, attaching to the 3D / 2D glass fiber mobile phone rear cover, and removing the base film to obtain the 3D / 2D glass fiber mobile phone rear cover with the patterned coating effect.

Description

Technical Field

[0001] This invention relates to the field of mobile phone back cover manufacturing technology, specifically a method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a graphic coating effect. Background Technology

[0002] Fiberglass, due to its high strength, light weight, good insulation, low cost, and strong weather resistance, has become an important component in the mobile phone back cover industry and is highly favored by consumers. With increasingly mature manufacturing processes, the mainstream technologies used for fiberglass mobile phone back covers currently include 3D printing, 2D transfer printing, and 3D OMR vacuum bonding. These processes all heavily rely on PVD to achieve the electroplating effect, and PVD plays an irreplaceable role in enhancing the appearance and functionality of the back cover.

[0003] Currently used PVD methods include electron gun evaporation, magnetron sputtering, and ion plating, which can provide a variety of coating effects such as brightening, bright silver, gradients, and dielectric films. However, regardless of the PVD technology used, existing processes struggle to achieve patterned coatings, typically only achieving full coverage, lacking pattern variation and novelty, thus limiting the diversity of appearance designs.

[0004] Therefore, there is a need to develop a method that can graphically represent the coating effect and apply it to fiberglass mobile phone back covers. This method can enrich the appearance of fiberglass mobile phone back covers, enhance visual novelty and product differentiation, further improve the user experience, and better meet the diverse needs of the market. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: Step 1: Apply release agent to the base film to obtain a base film with release agent; Step 2: After applying a hardening liquid to the base film containing the release agent, screen print a transparent varnish to obtain a base film with a varnish layer; Step 3: Transfer the UV inner texture layer 1 onto the varnish layer to obtain the transfer base film; after electroplating the transfer base film, offset print the pattern to obtain a material with graphic effect; Step 4: Place the material with graphic effect into the optical stripping solution bath for stripping to obtain a material with PVD1 graphic effect; screen print transparent varnish on the material with PVD1 graphic effect, bake and cure to obtain the pretreated material; Step 5: Repeat step 3, transfer the UV inner texture layer 2 onto the pretreated material and then perform electroplating to obtain a material with the effect of PVD2 electroplating layer. Step 6: Screen print ink onto the PVD2 electroplated layer of the material, bake and dry to obtain a patterned coating film. Step 7: After applying adhesive to the ink cover of the graphic coating effect film, bond it to the 3D / 2D glass fiber mobile phone back cover. After bonding, remove the base film with release agent to obtain the graphic coating effect 3D / 2D glass fiber mobile phone back cover.

[0007] Furthermore, the base film mentioned in step 1 is one of a polyolefin film or a polyethylene terephthalate film, and the thickness of the base film is 0.05~0.2mm.

[0008] Furthermore, the preparation method of the ultraviolet inner texture layer 1 in step 3 is as follows: the ultraviolet curable resin is uniformly coated on the ultraviolet photolithography mold layer, and after imprinting, it is irradiated with a 250~400nm ultraviolet lamp for 1~2 minutes to cure, thereby obtaining the ultraviolet inner texture layer 1; by mass parts, the raw material composition of the ultraviolet curable resin is: 40~60 parts of bisphenol A epoxy acrylate, 1~5 parts of photoinitiator 1173, and 10~30 parts of monomer trimethylolpropane triacrylate.

[0009] Furthermore, in step 1, the coating thickness of the release agent is 5-40 μm; in step 2, the coating thickness of the hardening liquid is 10-40 μm, and the thickness of the screen-printed transparent varnish is 8-20 μm; in step 3, the thickness of the transferred UV inner texture layer 1 is 8-30 μm, and the thickness of the electroplated layer is 30-300 nm; in step 4, the thickness of the screen-printed transparent varnish is 3-20 μm; in step 5, the thickness of the transferred UV inner texture layer 2 is 5-30 μm; in step 6, the screen-printed ink cover bottom layer is screen-printed in 3-5 layers, with each ink layer having a thickness of 8-15 μm, and the total thickness of the ink cover bottom layer is 30-80 μm; and in step 7, the thickness of the adhesive coating is 15-40 μm.

[0010] Furthermore, the effect of the electroplated layer described in step 3 is one of the following: transparent brightening, bright silver, or colored film.

[0011] Furthermore, the optical stripping solution in step 4 is composed of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5; and the optical stripping solution and deionized water are mixed in a mass ratio of 1:(2~10).

[0012] Furthermore, the bisphenol A epoxy acrylate undergoes modification treatment, specifically as follows: S1: Disperse nano-alumina in toluene and add triethylamine. Stir at 200-300 r / min for 20-40 min, then add an aqueous solution of γ-methacryloxypropyltrimethoxysilane. Raise the temperature to 100-120℃ and react under reflux for 4-5 h. After the reaction is complete, recover the toluene solvent, wash 3-5 times with anhydrous ethanol, dry in a drying oven at 60-80℃ for 4-5 h, cool, and grind to obtain modified nano-alumina. S2: Mix bisphenol A epoxy acrylate, reactive diluent hexanediol diacrylate and initiator TPO evenly, then add modified nano alumina and stir at 5000~5500 r / min for 10~25 min under ice bath conditions to obtain modified bisphenol A epoxy acrylate.

[0013] Furthermore, in S1, the nano-alumina, toluene, triethylamine, and γ-methacryloxypropyltrimethoxysilane aqueous solution are mixed in a mass ratio of 5:200:0.45:2; in S2, the bisphenol A epoxy acrylate, the reactive diluent hexanediol diacrylate, the initiator TPO, and the modified nano-alumina are mixed in a mass ratio of 80:20:3:3.

[0014] Furthermore, the preparation steps of the adhesive described in step 7 are as follows: S1: Dissolve dimerized rosin in tetrahydrofuran, stir magnetically to form a homogeneous solution, add oxaloyl chloride dropwise, and stir continuously at 20-25℃ for 5-7 hours. After the reaction is complete, evaporate by rotary evaporation, then add triethylamine and ethylene glycol dropwise, and react at 40-60℃ for 5-7 hours. Cool the reaction solution to 20-25℃, filter, and wash with dilute hydrochloric acid and sodium carbonate aqueous solution 3-5 times each. Finally, dry in a vacuum drying oven at 40-60℃ for 23-25 ​​hours to obtain rosin-based polyurethane chain extender. S2: The polyester polyol is vacuum dried at 110~130℃ for 3~4h and then diphenylmethane diisocyanate is added at 70~90℃. The temperature is raised to 110~130℃ and reacted for 0.5~1h. After the reaction is completed, the temperature is lowered to 90~105℃, rosin-based polyurethane chain extender is added, and the reaction is continued for 0.5~1h to obtain the adhesive.

[0015] Furthermore, in S1, the dimer rosin, tetrahydrofuran, oxaloyl chloride, triethylamine, and ethylene glycol are mixed in a mass ratio of 15:50:6.5:5.2:3.2; in S2, the polyester polyol, diphenylmethane diisocyanate, and rosin-based polyurethane chain extender are mixed in a mass ratio of 50:11.3:6.9.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention describes a method for manufacturing a 3D / 2D fiberglass mobile phone back cover with a graphic coating effect. The graphic coating fiberglass mobile phone back cover manufacturing method successfully overcomes the limitations of traditional coating technology in achieving patterned effects. This method can achieve graphic coating effects such as dual textures on the surface of 3D / 2D fiberglass mobile phone back covers, significantly enhancing the diversity and novelty of product appearance design. It not only enriches the visual expression of fiberglass mobile phone back covers but also better meets the market's consumer demand for personalized and differentiated products.

[0017] 2. The present invention describes a method for manufacturing a patterned 3D / 2D fiberglass mobile phone back cover with a patterned coating effect. This method modifies the surface of nano-alumina using a silane coupling agent, enabling it to form a three-dimensional polymer network with bisphenol A epoxy acrylate and TMPTA monomers via covalent bonds after curing. This not only solves the problem of nanoparticle aggregation and achieves uniform dispersion in the matrix, but also synergistically and significantly improves the comprehensive mechanical properties of the cured coating, such as hardness, wear resistance, heat resistance, and adhesion. Simultaneously, it ensures high light transmittance and rapid curing efficiency, providing an ideal high-performance substrate for subsequent PVD coating processes.

[0018] 3. The present invention describes a method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect. The adhesive used in the preparation is a rosin-based polyurethane chain extender, which introduces the rigid hydrogenated phenanthrene ring structure of natural rosin into the polyurethane main chain, giving the adhesive high cohesive strength, excellent adhesion, good thermal stability and rigidity. As a reactive polyurethane hot melt adhesive, it has the characteristics of being solvent-free and environmentally friendly, easy to operate and forming permanent chemical bonds after curing. It exhibits high heat resistance and water resistance, meeting the long-term reliable bonding requirements of electronic devices. Attached Figure Description

[0019] Figure 1 This is a layered diagram of the process structure of a patterned coating effect 3D / 2D fiberglass mobile phone back cover, which is a manufacturing method of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the following specific implementation, Polyolefin film: Model PO500, purchased from Dongguan Yili Plastics Co., Ltd.; Release agent: Product No. 3224, purchased from Suzhou Senfida Chemical Co., Ltd.; Hardening fluid: Model UV-938, purchased from Kunshan Baris International Trade Co., Ltd.; Transparent varnish: LED model number screen printed, purchased from Zhengzhou Yixiang Environmental Protection Technology Co., Ltd.; Bisphenol A epoxy acrylate: purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.; Photoinitiator 1173: Product No. S50293, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; Indium tin oxide: Part number AM-ITO-042-1, purchased from Zhejiang Yamei Nanotechnology Co., Ltd.; Acid-resistant ink: Model LY-2006, purchased from Shenzhen Laiyuan New Materials Co., Ltd.; Ink: AOMA monomer, purchased from Shanghai Hanluo New Materials Co., Ltd.; Trimethylolpropane triacrylate monomer: Product No. 3348, purchased from Suzhou Senfida Chemical Co., Ltd.; Nano alumina: Product number KL800207, purchased from Shanghai Kanglang Biotechnology Co., Ltd.; γ-Methacryloxypropyltrimethoxysilane: Product No. S15030, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; Initiator TPO: Product No. S31034, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; Hexanediol diacrylate: Product number YK4799, purchased from Hubei Yongkuo Technology Co., Ltd.; Dimeric rosin: Grade 95, purchased from Guangzhou Jinshengji Chemical Co., Ltd.; Polyester polyol: molecular weight 2000, model PS-3152, purchased from Qingdao Ruinuo Chemical Co., Ltd.; Diphenylmethane diisocyanate: Product No. W01106, purchased from Wuhan Jiyesheng Chemical Co., Ltd.; Nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid, hydrogen peroxide, toluene, triethylamine, anhydrous ethanol, tetrahydrofuran, oxaloyl chloride, and ethylene glycol were all of analytical grade. In the following examples, one part is 1g.

[0022] Example 1: A method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, comprising the following steps: Step 1: Use a 0.05mm polyolefin film as the base film, and coat the base film with a release agent with a coating thickness of 5μm to obtain a base film with release agent; Step 2: Apply a curing liquid to the base film containing the release agent, with a coating thickness of 10 μm, to obtain a base film coated with the curing liquid; screen print a transparent varnish on the base film coated with the curing liquid, with a thickness of 8 μm, to obtain a base film with a varnish layer. Step 3: By weight, mix 40 parts of bisphenol A epoxy acrylate, 1 part of photoinitiator 1173 and 10 parts of monomer trimethylolpropane triacrylate evenly to obtain UV-curable resin; coat the UV-curable resin evenly on the UV photolithography mold layer, and roll it onto the UV photolithography mold using a transfer machine, then irradiate with a 250nm UV lamp for 1 minute to cure it. Separate the UV-curable resin from the UV photolithography mold to obtain UV inner texture layer 1; Step 4: Transfer the UV inner texture layer 1 onto the varnish layer. The texture layer thickness is 8μm to obtain the transfer base film. Place the transfer base film into a magnetron sputtering machine for electroplating. The electroplating material is indium tin oxide, and the plating effect is transparent brightening with a thickness of 30nm to obtain a material with the effect of electroplating layer 1. Step 5: Place the material with the electroplating layer 1 effect into the offset printing machine, use acid-resistant ink to print the pattern, and obtain a material with graphic effect; Step 6: Place the material with the graphic effect into the optical stripping solution bath. The optical stripping solution (composed of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5) and deionized water are mixed in a mass ratio of 1:2. Soak for 5 seconds, then rinse with clean water. The coating without the offset pattern disappears, while the graphic effect of the coating with the offset pattern remains on the material, resulting in a material with PVD1 graphic effect. Step 7: Screen print a transparent varnish with a thickness of 3μm onto the material with PVD1 graphic effect, bake and cure to obtain the pretreated material; Step 8: Repeat steps 3 and 4 to transfer the UV inner texture layer 2 with a thickness of 5μm onto the pretreated material to obtain a material with the UV inner texture layer 2; place the material with the UV inner texture layer 2 into a magnetron sputtering machine for electroplating to obtain a material with the PVD2 electroplating effect. Step 9: Screen print ink on the PVD2 electroplated layer of the material, in 3 layers, each ink layer is 10μm thick, and the total thickness of the ink on the bottom layer is 30μm. Bake and dry to obtain a patterned coating film. Step 10: Apply an adhesive (item number: QIS-333, purchased from Dongguan Jingda Polymer New Materials Co., Ltd.) with a thickness of 15μm to the ink cover of the patterned coating film. Place the film and the 3D / 2D glass fiber mobile phone back cover into a vacuum laminator for bonding. After bonding, remove the base film with release agent to obtain the patterned coating effect 3D / 2D glass fiber mobile phone back cover.

[0023] Example 2: A method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, comprising the following steps: Step 1: Use a 0.05mm polyolefin film as the base film, and coat the base film with a release agent with a coating thickness of 5μm to obtain a base film with release agent; Step 2: Apply a curing liquid to the base film containing the release agent, with a coating thickness of 10 μm, to obtain a base film coated with the curing liquid; screen print a transparent varnish on the base film coated with the curing liquid, with a thickness of 8 μm, to obtain a base film with a varnish layer. Step 3: By weight, mix 40 parts of bisphenol A epoxy acrylate, 1 part of photoinitiator 1173 and 10 parts of monomer trimethylolpropane triacrylate evenly to obtain UV-curable resin; coat the UV-curable resin evenly on the UV photolithography mold layer, and roll it onto the UV photolithography mold using a transfer machine, then irradiate with a 250nm UV lamp for 1 minute to cure it. Separate the UV-curable resin from the UV photolithography mold to obtain UV inner texture layer 1; Step 4: Transfer the UV inner texture layer 1 onto the varnish layer. The texture layer thickness is 8μm to obtain the transfer base film. Place the transfer base film into a magnetron sputtering machine for electroplating. The electroplating material is indium tin oxide. The electroplating effect is transparent brightening. The thickness is 30nm to obtain a material with the effect of electroplating layer 1. Step 5: Place the material with the electroplating layer 1 effect into the offset printing machine, use acid-resistant ink to print the pattern, and obtain a material with graphic effect; Step 6: Place the material with the graphic effect into the optical stripping solution bath. The optical stripping solution (composed of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5) and deionized water are mixed in a mass ratio of 1:2. Soak for 5 seconds, then rinse with clean water. The coating without the offset pattern disappears, while the graphic effect of the coating with the offset pattern remains on the material, resulting in a material with PVD1 graphic effect. Step 7: Screen print a transparent varnish with a thickness of 3μm onto the material with PVD1 graphic effect, bake and cure to obtain the pretreated material; Step 8: Repeat steps 3 and 4 to transfer the UV inner texture layer 2 with a thickness of 5μm onto the pretreated material to obtain a material with the UV inner texture layer 2; place the material with the UV inner texture layer 2 into a magnetron sputtering machine for electroplating to obtain a material with the PVD2 electroplating effect. Step 9: Screen print ink on the PVD2 electroplated layer of the material, in 3 layers, each ink layer is 10μm thick, and the total thickness of the ink on the bottom layer is 30μm. Bake and dry to obtain a patterned coating film. Step 10: Apply an adhesive with a thickness of 15μm to the ink cover of the patterned coating effect film. Place the film and the 3D / 2D glass fiber mobile phone back cover into a vacuum laminator for bonding. After bonding, remove the base film with release agent to obtain the patterned coating effect 3D / 2D glass fiber mobile phone back cover. The bisphenol A epoxy acrylate underwent modification treatment, the specific steps of which are as follows: S1: 5g of nano-alumina was dispersed in 200mL of toluene, and 0.45g of triethylamine was added. The mixture was stirred at 200r / min for 20min to ensure that the nano-alumina was fully dispersed and wetted. Then, an aqueous solution of γ-methacryloxypropyltrimethoxysilane (1mL of γ-methacryloxypropyltrimethoxysilane and 1mL of deionized water) was added. The temperature was raised to 100℃ and the reaction was carried out under reflux for 4h. After the reaction was completed, the toluene solvent was recovered, and the mixture was washed three times with anhydrous ethanol. The mixture was dried in a drying oven at 60℃ for 4h. After cooling, the mixture was ground in a ball mill to obtain modified nano-alumina. S2: Mix 80g of bisphenol A epoxy acrylate, 20g of reactive diluent hexanediol diacrylate and 3g of initiator TPO evenly, then add 3g of modified nano alumina and stir for 10min at 5000r / min under ice bath conditions to obtain modified bisphenol A epoxy acrylate. The preparation steps of the adhesive are as follows: S1: Dissolve 15g of dimerized rosin in 50mL of tetrahydrofuran and stir magnetically to form a homogeneous solution. Slowly add 6.5g of oxaloyl chloride and stir continuously at 20℃ for 5h. After the reaction is complete, remove the remaining oxaloyl chloride and tetrahydrofuran solvent by rotary evaporation. Then add 5.2g of triethylamine and 3.2g of ethylene glycol and react at 40℃ for 5h. Cool the reaction solution to 20℃, filter to remove the triethylamine hydrochloride precipitate, wash three times each with dilute hydrochloric acid and sodium carbonate aqueous solution, and finally dry in a vacuum drying oven at 40℃ for 23h to obtain rosin-based polyurethane chain extender. S2: 50g of polyester polyol was vacuum dried at 110℃ for 3h to remove trace amounts of moisture from the reactants. Then, it was added to a 250mL three-necked round-bottom flask. 11.3g of diphenylmethane diisocyanate was added at 70℃, and the temperature was raised to 110℃ for 0.5h. After the reaction was completed, the temperature was lowered to 90℃, and 6.9g of rosin-based polyurethane chain extender was added. The reaction was continued for 0.5h to obtain the adhesive.

[0024] Example 3: A method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, comprising the following steps: Step 1: Use a 0.1 mm polyolefin film as the base film, and coat the base film with a release agent with a coating thickness of 15 μm to obtain a base film with release agent; Step 2: Apply a curing liquid to the base film containing the release agent, with a coating thickness of 20 μm, to obtain a base film coated with the curing liquid; screen print a transparent varnish on the base film coated with the curing liquid, with a thickness of 15 μm, to obtain a base film with a varnish layer. Step 3: By weight, mix 50 parts of bisphenol A epoxy acrylate, 3 parts of photoinitiator 1173 and 20 parts of monomer trimethylolpropane triacrylate evenly to obtain UV-curable resin; coat the UV-curable resin evenly on the UV photolithography mold layer, and roll it onto the UV photolithography mold using a transfer machine; irradiate with a 350nm UV lamp for 1.5 minutes to cure; the UV-curable resin separates from the UV photolithography mold to obtain UV inner texture layer 1; Step 4: Transfer the UV inner texture layer 1 onto the varnish layer. The texture layer thickness is 15μm to obtain the transfer base film. Place the transfer base film into a magnetron sputtering machine for electroplating. The electroplating material is indium tin oxide, and the electroplating effect is transparent brightening. The thickness is 100nm to obtain a material with the effect of electroplating layer 1. Step 5: Place the material with the electroplating layer 1 effect into the offset printing machine, use acid-resistant ink to print the pattern, and obtain a material with graphic effect; Step 6: Place the material with the graphic effect into the optical stripping solution bath. The optical stripping solution (composed of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5) and deionized water are mixed in a mass ratio of 1:6. Soak for 10 seconds, then rinse with clean water. The coating without the offset pattern disappears, while the graphic effect of the coating with the offset pattern is retained on the material, resulting in a material with PVD1 graphic effect. Step 7: Screen print a transparent varnish with a thickness of 15μm onto the material with PVD1 graphic effect, bake and cure to obtain the pretreated material; Step 8: Repeat steps 3 and 4 to transfer the UV inner texture layer 2 with a thickness of 20 μm onto the pretreated material to obtain a material with the UV inner texture layer 2; place the material with the UV inner texture layer 2 into a magnetron sputtering machine for electroplating to obtain a material with the PVD2 electroplating effect. Step 9: Screen print ink over the bottom layer on the PVD2 electroplated layer of the material. Screen print in 4 layers, each ink layer is 11μm thick, and the total thickness of the ink over the bottom layer is 44μm. Bake and dry to obtain a patterned coating film. Step 10: Apply an adhesive with a thickness of 30μm to the ink cover of the patterned coating effect film. Place the film and the 3D / 2D glass fiber mobile phone back cover into a vacuum laminator for bonding. After bonding, remove the base film with release agent to obtain the patterned coating effect 3D / 2D glass fiber mobile phone back cover. The bisphenol A epoxy acrylate underwent modification treatment, the specific steps of which are as follows: S1: 5g of nano-alumina was dispersed in 200mL of toluene, and 0.45g of triethylamine was added. The mixture was stirred at 250r / min for 30min to ensure that the nano-alumina was fully dispersed and wetted. Then, an aqueous solution of γ-methacryloxypropyltrimethoxysilane (1mL of γ-methacryloxypropyltrimethoxysilane and 1mL of deionized water) was added. The temperature was raised to 110℃ and the reaction was carried out under reflux for 4.5h. After the reaction was completed, the toluene solvent was recovered, and the mixture was washed four times with anhydrous ethanol. The mixture was dried in a drying oven at 70℃ for 4.5h. After cooling, the mixture was ground in a ball mill to obtain modified nano-alumina. S2: Mix 80g of bisphenol A epoxy acrylate, 20g of reactive diluent hexanediol diacrylate and 3g of initiator TPO evenly, then add 3g of modified nano alumina and stir for 20min at 5250r / min using a high-speed disperser under ice bath conditions to obtain modified bisphenol A epoxy acrylate. The preparation steps of the adhesive are as follows: S1: Dissolve 15g of dimerized rosin in 50mL of tetrahydrofuran and stir magnetically to form a homogeneous solution. Slowly add 6.5g of oxaloyl chloride and stir continuously at 23℃ for 6h. After the reaction is complete, remove the remaining oxaloyl chloride and tetrahydrofuran solvent by rotary evaporation. Then add 5.2g of triethylamine and 3.2g of ethylene glycol and react at 50℃ for 6h. Cool the reaction solution to 23℃, filter to remove the triethylamine hydrochloride precipitate, wash with dilute hydrochloric acid and sodium carbonate aqueous solution 4 times each, and finally dry in a vacuum drying oven at 50℃ for 24h to obtain rosin-based polyurethane chain extender. S2: 50g of polyester polyol was vacuum dried at 120℃ for 3.5h to remove trace amounts of moisture from the reactants. Then, it was added to a 250mL three-necked round-bottom flask. 11.3g of diphenylmethane diisocyanate was added at 80℃, and the temperature was raised to 120℃ for 0.7h. After the reaction was completed, the temperature was lowered to 100℃, and 6.9g of rosin-based polyurethane chain extender was added. The reaction was continued for 0.7h to obtain the adhesive.

[0025] Example 4: A method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, comprising the following steps: Step 1: Using a 0.2 mm polyolefin film as the base film, a release agent is coated onto the base film to a thickness of 40 μm, resulting in a base film with release agent. Step 2: Apply a curing liquid to the base film containing the release agent, with a coating thickness of 40 μm, to obtain a base film coated with the curing liquid; screen print a transparent varnish on the base film coated with the curing liquid, with a thickness of 20 μm, to obtain a base film with a varnish layer. Step 3: By weight, mix 60 parts of bisphenol A epoxy acrylate, 5 parts of photoinitiator 1173 and 30 parts of monomer trimethylolpropane triacrylate evenly to obtain UV-curable resin; coat the UV-curable resin evenly on the UV photolithography mold layer, and roll it onto the UV photolithography mold using a transfer machine; irradiate with a 400nm UV lamp for 2 minutes to cure; separate the UV-curable resin from the UV photolithography mold to obtain UV inner texture layer 1; Step 4: Transfer the UV inner texture layer 1 onto the varnish layer. The texture layer thickness is 30μm to obtain the transfer base film. Place the transfer base film into a magnetron sputtering machine for electroplating. The electroplating material is indium tin oxide. The electroplating effect is transparent brightening. The thickness is 300nm to obtain a material with the effect of electroplating layer 1. Step 5: Place the material with the electroplating layer 1 effect into the offset printing machine, use acid-resistant ink to print the pattern, and obtain a material with graphic effect; Step 6: Place the material with the graphic effect into the optical stripping solution bath. The optical stripping solution (composed of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5) and deionized water are mixed in a mass ratio of 1:10. Soak for 20 seconds, then rinse with clean water. The coating without the offset pattern disappears, while the graphic effect of the coating with the offset pattern is retained on the material, resulting in a material with PVD1 graphic effect. Step 7: Screen print a transparent varnish with a thickness of 20μm onto the material with PVD1 graphic effect, bake and cure to obtain the pretreated material; Step 8: Repeat steps 3 and 4 to transfer the UV inner texture layer 2 with a thickness of 30 μm onto the pretreated material to obtain a material with the UV inner texture layer 2; place the material with the UV inner texture layer 2 into a magnetron sputtering machine for electroplating to obtain a material with the PVD2 electroplating effect. Step 9: Screen print ink on the PVD2 electroplated layer of the material, in 5 layers, each ink layer is 15μm thick, and the total thickness of the ink on the bottom layer is 75μm. Bake and dry to obtain a patterned coating film. Step 10: Apply an adhesive with a thickness of 40μm to the ink cover of the patterned coating effect film. Place the film and the 3D / 2D glass fiber mobile phone back cover into a vacuum laminator for bonding. After bonding, remove the base film with release agent to obtain the patterned coating effect 3D / 2D glass fiber mobile phone back cover. The bisphenol A epoxy acrylate underwent modification treatment, the specific steps of which are as follows: S1: 5g of nano-alumina was dispersed in 200mL of toluene, and 0.45g of triethylamine was added. The mixture was stirred at 300r / min for 40min to ensure that the nano-alumina was fully dispersed and wetted. Then, an aqueous solution of γ-methacryloxypropyltrimethoxysilane (1mL of γ-methacryloxypropyltrimethoxysilane and 1mL of deionized water) was added. The temperature was raised to 120℃ and the reaction was carried out under reflux for 5h. After the reaction was completed, the toluene solvent was recovered, and the mixture was washed 5 times with anhydrous ethanol. The mixture was dried in an 80℃ drying oven for 5h. After cooling, the mixture was ground in a ball mill to obtain modified nano-alumina. S2: Mix 80g of bisphenol A epoxy acrylate, 20g of reactive diluent hexanediol diacrylate and 3g of initiator TPO evenly, then add 3g of modified nano alumina and stir for 25min at 5500r / min using a high-speed disperser under ice bath conditions to obtain modified bisphenol A epoxy acrylate. The preparation steps of the adhesive are as follows: S1: Dissolve 15g of dimerized rosin in 50mL of tetrahydrofuran and stir magnetically to form a homogeneous solution. Slowly add 6.5g of oxaloyl chloride and stir continuously at 25℃ for 7h. After the reaction is complete, remove the remaining oxaloyl chloride and tetrahydrofuran solvent by rotary evaporation. Then add 5.2g of triethylamine and 3.2g of ethylene glycol and react at 60℃ for 7h. Cool the reaction solution to 25℃, filter to remove the triethylamine hydrochloride precipitate, wash with dilute hydrochloric acid and sodium carbonate aqueous solution 5 times each, and finally dry in a vacuum drying oven at 60℃ for 25h to obtain rosin-based polyurethane chain extender. S2: 50g of polyester polyol was vacuum dried at 130℃ for 4h to remove trace amounts of moisture from the reactants. Then, it was added to a 250mL three-necked round-bottom flask. 11.3g of diphenylmethane diisocyanate was added at 90℃, and the temperature was raised to 130℃ for 1h. After the reaction was completed, the temperature was lowered to 105℃, 6.9g of rosin-based polyurethane chain extender was added, and the reaction was continued for 1h to obtain the adhesive.

[0026] Experiment: The adhesive properties, thermal stability, and water resistance of the adhesives used in Examples 1-4 were tested. Adhesion strength test: Apply adhesive to the overlapping area (12.5mm long, 25mm wide) of two substrates (100mm long, 25mm wide, and 2mm back), place them at 25℃ and 50% relative humidity for 7 days, and then test them. The speed of the universal testing machine is 5mm / min. Thermogravimetric analysis test: 10mg sample was heated from 25℃ to 600℃ at a heating rate of 10℃ / min under nitrogen protection and tested using a thermogravimetric analyzer; Water resistance test: The substrate bonded with the adhesive was placed in water at 80℃ for 7 days and dried at 25℃ and 50% relative humidity for 1 day, and then the shear strength was tested. All test results are shown in Table 1.

[0027] Table 1 As can be seen from the data in Table 1, the self-made adhesives prepared in Examples 2-4 have higher bonding strength than the commercially available adhesive in Example 1. The temperature at which the adhesive loses 5% of its weight is also higher than that of Example 1. Furthermore, the shear strength of Example 1 in the water resistance test is lower than that of Examples 2-4. This indicates that the self-made adhesives in Examples 2-4 improve their bonding strength, heat resistance, and water resistance by adding rosin-based polyurethane chain extenders.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0029] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect, characterized in that: Includes the following steps: Step 1: Apply release agent to the base film to obtain a base film with release agent; Step 2: After applying a hardening liquid to the base film containing the release agent, screen print a transparent varnish to obtain a base film with a varnish layer; Step 3: Transfer the UV inner texture layer 1 onto the varnish layer to obtain the transfer base film; after electroplating the transfer base film, offset print the pattern to obtain a material with graphic effect; Step 4: Place the material with the graphic effect into the optical stripping solution bath for stripping to obtain a material with PVD1 graphic effect; A transparent varnish is screen-printed onto a material with PVD1 graphic effects, and then baked and cured to obtain a pre-treated material. Step 5: Repeat step 3, transfer the UV inner texture layer 2 onto the pretreated material and then perform electroplating to obtain a material with the effect of PVD2 electroplating layer. Step 6: Screen print ink onto the PVD2 electroplated layer of the material, bake and dry to obtain a patterned coating film. Step 7: After applying adhesive to the ink cover of the graphic coating effect film, bond it to the 3D / 2D glass fiber mobile phone back cover. After bonding, remove the base film with release agent to obtain the graphic coating effect 3D / 2D glass fiber mobile phone back cover.

2. The manufacturing method of a patterned coating effect 3D / 2D glass fiber mobile phone back cover according to claim 1, characterized in that: The base film mentioned in step 1 is one of polyolefin film and polyethylene terephthalate film, and the thickness of the base film is 0.05~0.2mm.

3. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 1, characterized in that: The method for preparing the ultraviolet inner texture layer 1 in step 3 is as follows: the ultraviolet curable resin is uniformly coated on the ultraviolet photolithography mold layer, and after imprinting, it is irradiated with a 250~400nm ultraviolet lamp for 1~2 minutes to cure, thereby obtaining the ultraviolet inner texture layer 1; the raw material composition of the ultraviolet curable resin by mass parts is: 40~60 parts of bisphenol A epoxy acrylate, 1~5 parts of photoinitiator 1173, and 10~30 parts of monomer trimethylolpropane triacrylate.

4. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 1, characterized in that: The thickness of the release agent coating in step 1 is 5~40μm; the thickness of the hardening liquid coating in step 2 is 10~40μm, and the thickness of the screen-printed transparent varnish is 8~20μm; the thickness of the transfer UV inner texture layer 1 in step 3 is 8~30μm, and the thickness of the electroplated layer is 30~300nm; the thickness of the screen-printed transparent varnish in step 4 is 3~20μm; the thickness of the transfer UV inner texture layer 2 in step 5 is 5~30μm; the screen-printed ink cover bottom layer in step 6 is screen-printed in 3~5 layers, with each ink layer having a thickness of 8~15μm, and the total thickness of the ink cover bottom layer is 30~80μm; the thickness of the adhesive coating in step 7 is 15~40μm.

5. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 1, characterized in that: The effect of the electroplated layer described in step 3 is one of the following: transparent brightening, bright silver, or colored film.

6. The manufacturing method of a patterned coating effect 3D / 2D glass fiber mobile phone back cover according to claim 1, characterized in that: The optical stripping solution described in step 4 consists of nitric acid, sulfuric acid, ammonia, ethylenediaminetetraacetic acid, citric acid, and hydrogen peroxide mixed in a mass ratio of 30:30:5:4:2:5; and optical stripping solution and deionized water mixed in a mass ratio of 1:(2~10).

7. The manufacturing method of a patterned coating effect 3D / 2D glass fiber mobile phone back cover according to claim 3, characterized in that: The bisphenol A epoxy acrylate underwent modification treatment, the specific steps of which are as follows: S1: Disperse nano-alumina in toluene and add triethylamine. Stir at 200-300 r / min for 20-40 min, then add an aqueous solution of γ-methacryloxypropyltrimethoxysilane. Raise the temperature to 100-120℃ and react under reflux for 4-5 h. After the reaction is complete, recover the toluene solvent, wash 3-5 times with anhydrous ethanol, dry in a drying oven at 60-80℃ for 4-5 h, cool, and grind to obtain modified nano-alumina. S2: Mix bisphenol A epoxy acrylate, reactive diluent hexanediol diacrylate and initiator TPO evenly, then add modified nano alumina and stir at 5000~5500 r / min for 10~25 min under ice bath conditions to obtain modified bisphenol A epoxy acrylate.

8. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 7, characterized in that: In S1, the nano-alumina, toluene, triethylamine, and γ-methacryloxypropyltrimethoxysilane aqueous solution are mixed in a mass ratio of 5:200:0.45:2; in S2, the bisphenol A epoxy acrylate, the reactive diluent hexanediol diacrylate, the initiator TPO, and the modified nano-alumina are mixed in a mass ratio of 80:20:3:

3.

9. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 1, characterized in that: The preparation steps of the adhesive mentioned in step 7 are as follows: S1: Dissolve dimerized rosin in tetrahydrofuran, stir magnetically to form a homogeneous solution, add oxaloyl chloride dropwise, and stir continuously at 20-25℃ for 5-7 hours. After the reaction is complete, evaporate by rotary evaporation, then add triethylamine and ethylene glycol dropwise, and react at 40-60℃ for 5-7 hours. Cool the reaction solution to 20-25℃, filter, and wash with dilute hydrochloric acid and sodium carbonate aqueous solution 3-5 times each. Finally, dry in a vacuum drying oven at 40-60℃ for 23-25 ​​hours to obtain rosin-based polyurethane chain extender. S2: The polyester polyol is vacuum dried at 110~130℃ for 3~4h and then diphenylmethane diisocyanate is added at 70~90℃. The temperature is raised to 110~130℃ and reacted for 0.5~1h. After the reaction is completed, the temperature is lowered to 90~105℃, rosin-based polyurethane chain extender is added, and the reaction is continued for 0.5~1h to obtain the adhesive.

10. The manufacturing method of a 3D / 2D glass fiber mobile phone back cover with a patterned coating effect according to claim 9, characterized in that: In S1, the dimeric rosin, tetrahydrofuran, oxaloyl chloride, triethylamine, and ethylene glycol are mixed in a mass ratio of 15:50:6.5:5.2:3.2; in S2, the polyester polyol, diphenylmethane diisocyanate, and rosin-based polyurethane chain extender are mixed in a mass ratio of 50:11.3:6.9.

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