A UV dual-curing ink and a preparation method thereof

Abstract

The application belongs to the technical field of electronic display material processing, and specifically discloses a UV double-curing ink and a preparation method thereof.The UV double-curing ink is composed of UV polyester acrylate, polyurethane acrylate containing a spiropyran group, UV modified epoxy acrylate, POSS-acrylate, a mixed solvent, a photoinitiator, an active amine, a leveling agent, pigments and a dispersing agent.The preparation method mainly comprises the following steps: firstly, the UV polyester acrylate, the polyurethane acrylate containing a spiropyran group, the UV modified epoxy acrylate and the POSS-acrylate are respectively subjected to premixing treatment; then, the other components are sequentially subjected to dispersion treatment and functionalization treatment; finally, the mixture obtained by the treatment is subjected to light-shielding storage to obtain the UV double-curing ink.The UV double-curing ink has good leveling property, wettability and bending stress, has the characteristics of high hardness and high adhesion, and can effectively prevent discoloration.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic display material processing, and particularly relates to a UV double-cured ink and a preparation method thereof. BACKGROUND

[0002] With the development of science and technology, electronic display screens gradually develop in the direction of high brightness, thinness and large size. In particular, optical film materials are used as key components in liquid crystal display screen modules to improve light brightness, improve light softness and widen the viewing angle. Optical film materials as key functional layers have become mainstream technology, meeting the composite requirements of light weight, surface protection, optical regulation and environmental reliability, excellent flexibility and bending resistance, etc. The optical film materials of the current electronic display screen generally use PET substrates to coat UV (ultraviolet light curing) ink to realize surface functionalization. As a photosensitive composite material, UV curing ink can connect materials such as oligomers, active diluents, photoinitiator TPO, etc. in the UV curing ink to polymerize and cross-link under the action of ultraviolet light of different wavelengths and energies, so that the UV curing ink is cured on the PET substrate. However, the traditional UV curing ink has systematic technical defects when constructing a functional coating on the PET substrate:

[0003] (1) The surface hardness of PET is insufficient (usually ≤2H), the surface adhesion is poor (transparent adhesive can be pulled off), and the phenomenon of ink bleeding easily occurs, which is not resistant to wear and tear, not resistant to scratching, and has poor wear resistance, which leads to easy scratching;

[0004] (3) Poor stability, low pigment light resistance level of the ink, easy color fading and migration; the system of the primer and the UV ink is incompatible, the primer layer generates stress due to the too fast curing of the UV ink, the interlayer adhesion between the UV ink layer and the primer is very poor, and the phenomenon of ink bleeding easily occurs, and even after the finished product is finally made, the surface coating layer also has peeling between the coating layers;

[0005] (3) Lack of effective anti-fingerprint treatment, affecting optical clarity; there is a blue light hazard hidden danger under high light transmittance, and long-term reliance on imports leads to high cost;

[0006] In addition, the traditional product is prone to adhesion decay and color change after THB humid heat test and QUV ultraviolet aging, and it is difficult to meet the stringent standards of PET accelerated aging of new optical film materials, which seriously restricts the development of high-end electronic display screens. SUMMARY

[0007] The purpose of the present application is to provide a UV double-cured ink and a preparation method thereof. The UV double-cured ink of the present application has good leveling property, wettability and bending stress, has the characteristics of high hardness and high adhesion, and can effectively prevent discoloration. In order to achieve the above purpose, the application adopts the following technical effects:

[0008] According to one aspect of the present application, the present application provides a UV dual-curing ink prepared from the following materials by mass fraction:

[0009] UV polyester acrylate 15-25%, polyurethane or acrylate containing spiropyran group 10-16%;

[0010] UV modified epoxy acrylate 16-25%, POSS-acrylate 10-15%;

[0011] Mixed solvent 16-24%, photoinitiator 3-7%;

[0012] Active amine 4-8%, leveling agent 0.4-1%;

[0013] Pigment 2-7%, dispersant 0.6-2.5%.

[0014] The above scheme is further preferably, the UV dual-curing ink prepared from the following materials by mass fraction:

[0015] UV polyester acrylate 18%, polyurethane or acrylate containing spiropyran group 12%;

[0016] UV modified epoxy acrylate 16%, POSS-acrylate 10%;

[0017] Mixed solvent 24%, photoinitiator 5%;

[0018] Active amine 6%, leveling agent 0.5%;

[0019] Pigment 6%, dispersant 2.5%.

[0020] The above scheme is further preferably, the pigment is one or more of inorganic pigment carbon black, inorganic pigment titanium cyan blue, inorganic pigment permanent red, inorganic permanent yellow, upconversion fluorescent nanoparticles.

[0021] The above scheme is further preferably, the upconversion fluorescent nanoparticles are NaYF4:Yb 3+ / Er 3+ @SiO2 nanometer core-shell structure material, NaYF4:Yb 3+ / Er 3+ @SiO2 nanometer core-shell structure material uses microemulsion method to wrap SiO2 on cubic phase rare earth upconversion fluorescent nanoparticle material NaYF4:Yb 3+ / Er 3+ The surface forms a good NaYF4:Yb 3+ / Er 3+ / SiO2 core-shell structure, the nano core-shell particle size is 50-150 nm, the SiO2 core-shell thickness is 5 nm-15 nm, and the cubic phase rare earth upconversion fluorescent nanomaterial NaYF4:Yb 3+ / Er 3+ UCNPs for short; wherein, NaYF4:Yb 3+ / Er 3+ / SiO2 core-shell structure is also written as NaYF4:Yb 3+ / Er 3+ @SiO2, NaYF4:Yb / Er / SiO2 or UCNPs@SiO2 nano core-shell structure. The SiO2 core-shell cooperates with the polyurethane acrylate to form a scattering network, improves the refractive index, improves the scattering of residual blue light, greatly improves the blue light conversion rate, and coats the surface of the optical film material to improve the surface hardness.

[0022] The POSS structure in the POSS-acrylate is preferably a polyhedral oligomeric silsesquioxane, which is a unique cage-shaped three-dimensional nano structure composed of silicon and oxygen atoms, and its molecular formula is (RSiO3 / 2)n. When n is an even number, a typical polyhedral oligomeric silsesquioxane, also known as POSS, is formed. POSS polymers can be prepared by conventional blending, grafting, crosslinking or copolymerization, etc. The mixed solvent is prepared by mixing ethyl acetate, butyl acetate and PMA propylene glycol monomethyl ether acetate in a mass ratio of 1:5-8:9-13. The mixed solvent can dilute UV polyester acrylate and UV modified epoxy acrylate, not only adjusting the viscosity, but also playing a role in rapid drying and leveling after being coated on the PET substrate.

[0023] The leveling agent is preferably a polyether-modified siloxane polymer or a perfluorobutyl ethyl acrylate. It can adjust the ink flowability and surface tension. Polyether-modified siloxane (such as polydimethylsiloxane) can improve the ink flowability, direct the ink flow, and improve the slipperiness and scratch resistance. Perfluorobutyl ethyl acrylate can reduce the ink viscosity to make the bubbles escape quickly, achieving the functions of defoaming and leveling.

[0024] The active amine is preferably one or both of N-methyldiethanolamine and triethanolamine. The active amine not only promotes the initiation efficiency of the photoinitiator and improves the ink curing hardness, but also inhibits oxygen inhibition when participating in the reaction of UV polyester acrylate, polyurethane or acrylate containing a spiropyran group, etc., blocks the oxidation path of spiropyran, prevents the ink from yellowing, and thus improves the stability of the ink dispersion system.

[0025] The amine group of N-methyldiethanolamine captures the peroxide radicals generated by ultraviolet photolysis, blocking the oxidative chain reaction; the amine group in triethanolamine forms a donor-acceptor complex with the open ring of spiropyran, inhibiting the degradation of the chromophore;

[0026] The active amine is composed of N-methyldiethanolamine and triethanolamine in a mass ratio of 1:0.8-1.2, and after compounding, it can improve the degree of deep curing of the ink.

[0027] Further preferably, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone, TPO, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, or 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] ethanone 1-(O-acetyloxime); in the present application, the photoinitiator can absorb light waveband radiant energy, excite chemical reaction, initiate free radical polymerization ability, and produce intermediate substances; wherein 1-hydroxycyclohexyl phenyl ketone is also known as 1-hydroxycyclohexyl phenyl ketone, photoinitiator 184, and UV-184, which can initiate ultraviolet light curing system polymerization under ultraviolet light irradiation and inhibit the long-term non-yellowing effect of the ink; TPO as a photoinitiator cooperates with the active amine to improve the deep curing efficiency and avoid yellowing caused by migration of unreacted monomers.

[0028] The chemical name of TPO is 2,4,6-trimethylbenzyl-diphenyl phosphine; the photolysis product of TPO is trimethylbenzoyl radical and diphenyl phosphine radical, and the absorption wavelength moves to short wave, which has a photobleaching effect and is beneficial to the transmission of ultraviolet light.

[0029] 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] ethanone 1-(O-acetyloxime) can absorb light energy to initiate specific chemical conversion reactions of free radicals, etc., has significant fluorescent properties, and can effectively absorb ultraviolet light, which can undergo electron transfer under light induction.

[0030] Phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide has the combination of aromatic ring system and phosphine functional group, and the phosphine group in the molecule affects the initiation activity, which can rapidly produce free radical initiation reaction under specific wavelength ultraviolet light irradiation, and can rapidly initiate crosslinking reaction with UV polyester acrylate and UV modified epoxy acrylate under UV light irradiation, promoting rapid curing effect and helping to improve the hardness of the photocured product. The absorption light characteristics of phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide as a photoinitiator are: three main absorption peaks in the ultraviolet light region, with wavelength absorption peaks of 335 nm, 370 nm, and 405 nm, and the maximum absorption wavelength can reach 450 nm, which has the characteristics of high photocuring efficiency and less residue.

[0031] Further preferably, the acrylate hydroxyl value of the UV polyester acrylate is 60±5 mg KOH / g, and the epoxy equivalent weight of the UV modified epoxy acrylate is 450-500 g / mol.

[0032] According to another aspect of the present application, the present application provides a preparation method of a UV dual-curing ink, comprising the following steps:

[0033] Premixing treatment: heat the POSS-acrylate to 55-70℃, then add the UV modified epoxy acrylate for premixing for 30 min to obtain an epoxy acrylate premix; mix the polyurethane or acrylate containing spiropyran groups with the UV polyester acrylate at 35-45℃ for 20-30 min to obtain a polyester acrylate premix;

[0034] Dispersion treatment: take a certain amount of mixed solvent and mix and grind with a dispersant and pigments to form a nano-powder fine material, add the nano-powder fine material to the epoxy acrylate premix and mix uniformly, then add the polyester acrylate premix at a rate of less than or equal to 5 mL / min for mixing and stirring to obtain a dispersion system;

[0035] Functionalization treatment: mix the remaining mixed solvent with part of the photoinitiator uniformly, then heat to 80-85℃, then sequentially add the dispersion system, active amine, leveling agent for mixing and stirring for 30 min, then use ultrasonic oscillation for 10 min, then add the remaining photoinitiator under light shielding conditions and stir uniformly, then store in the dark to obtain the UV dual-curing ink.

[0036] Further preferably, in the dispersion treatment step, the particle size of the nano-powder fine material obtained by mixing and grinding is 280-450 nm, and when the polyester acrylate premix is added at a rate of less than or equal to 5 mL / min for mixing and stirring, a magnetic field of 500-1000 Gs is applied.

[0037] Further preferably, when the POSS-acrylate is heated to 55-70℃, the viscosity of the POSS-acrylate is controlled to be 450±60 mPa·s.

[0038] In the present application, after the prepared UV dual-curing ink is coated on the PET substrate, the UV light irradiation is accelerated to dry and cure to form a light diffusion film, the UV polyester acrylate is used as a flexible matrix of the light diffusion film, absorbs the bending stress, and the branched structure (3-5 acrylate groups per molecule) of the polyester acrylate and the UV modified epoxy acrylate form gradient crosslinking during photocuring: the high crosslinking density of the surface area achieves 4H hardness, and the high-branched polyester in the near-substrate area ensures the adhesion between each layer; the spirobenzopyran group-containing polyurethane acrylate or the spirobenzopyran group-containing acrylate absorbs 480-600 nm yellow light in the closed ring state of the spirobenzopyran group, which has a significant effect on offsetting the yellowing of amine oxidation; the spirobenzopyran group forms a hydrogen bond with the hydroxyl group of the UV polyester, and the POSS structure of the acrylate fills the crosslinking network gap of the UV epoxy, which can absorb the bending stress and reduce the generation of cracks.

[0039] The UV modified epoxy acrylate is used as a rigid skeleton, which can improve the surface hardness; the acrylate molecule contains an acrylic functional group and the polyurethane (PU) contains a urethane bond, which not only enhances the wear resistance after curing, but also has excellent optical performance and weather resistance; the active amine can accelerate curing under the action of the photoinitiator, and plays a role in inhibiting oxygen inhibition.

[0040] In the present application, the application of the UV dual-curing ink in the light diffusion film is provided, and the light diffusion film is used in all electronic appliances with electronic display screens, such as television sets, vehicle displays, smart watches, mobile phones, household appliances, and AI glasses display screens. The application can reduce the damage of the light diffusion film when applied to the surface of the electronic display screen.

[0041] In summary, the present application has the following technical effects:

[0042] After the ink of the present application is coated on the surface of the PET substrate and dried and cured, a UV coating and an AG coating can be formed, AG is the abbreviation of Anti-Glare, which means anti-glare, which can reduce the specular reflection of environmental light (such as light, sunlight) on the screen surface, can significantly increase the AG effect on the surface, the light will not directly harm the eyes, the surface is not easy to be scratched, the leveling property and the wettability of the UV dual-curing ink are good, the UV dual-curing ink has the characteristics of high hardness and high adhesion, and the excellent bending stress of the UV dual-curing ink can also effectively prevent discoloration. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a flowchart of the preparation method of the UV dual-curing ink of the present application. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects of the invention can be achieved even without these specific details.

[0045] Example 1, such as Figure 1 As shown, according to the invention, a UV dual-curing ink is prepared from the following materials by weight: 25% UV polyester acrylate, 10% polyurethane containing spiropyran groups or acrylate containing spiropyran groups, 20% UV-modified epoxy acrylate, 12% POSS-acrylate, 18% mixed solvent, 4% photoinitiator, 8% active amine, 0.8% leveling agent, 4% pigment, and 1.2% dispersant; the hydroxyl value of the acrylate in the UV polyester acrylate is 60±5 mgKOH / g; the epoxy equivalent of the UV-modified epoxy acrylate is 450 g / mol.

[0046] The pigments are inorganic pigments carbon black, inorganic pigments titanium blue, inorganic pigments permanent red, inorganic permanent yellow, and upconversion fluorescent nanoparticles; the leveling agent is a polyether-modified siloxane polymer; and the photoinitiator is 1-hydroxycyclohexylphenyl ketone.

[0047] The active amine is N-methyldiethanolamine; the mixed solvent is composed of ethyl acetate, butyl acetate, and PMA propylene glycol monomethyl ether acetate in a mass ratio of 1:5:9.

[0048] The preparation method of a UV dual-curing ink of the present invention includes the following steps:

[0049] Raw material weighing: Weigh the following raw materials according to the mass ratio: 25% UV polyester acrylate, 10% polyurethane or acrylate containing spiropyran groups, 20% UV modified epoxy acrylate, 12% POSS-acrylate, 18% mixed solvent, 4% photoinitiator, 8% active amine, 0.8% leveling agent, 4% pigment, and 1.2% dispersant;

[0050] Premixing treatment: POSS-acrylate is heated to 55°C and its viscosity is controlled at 390 mPa·s. Then, UV-modified epoxy acrylate is added and premixed for 30 min to obtain epoxy acrylate premix. Polyurethane containing spiropyran groups or acrylate containing spiropyran groups is mixed with UV polyester acrylate at 35°C for 30 min to obtain polyester acrylate premix.

[0051] Dispersion treatment: Take 50% by weight of mixed solvent, dispersant and pigment, mix and grind into 280nm powder, then add the nano powder fines to epoxy acrylate premix and mix evenly. Add polyester acrylate premix at a rate of less than or equal to 5mL / min and mix and stir. At the same time, apply a 500Gs magnetic field to promote the directional arrangement and mixing of POSS-acrylate to obtain the dispersion system mixture.

[0052] Functionalization process: Mix the remaining mixed solvent with a portion of the photoinitiator evenly, then heat to 80°C, and then add the dispersant system, active amine, and leveling agent in sequence and mix for 30 minutes. After ultrasonic oscillation and dispersion for 10 minutes, add the remaining photoinitiator under light-protected conditions and stir evenly. Then seal and store in the dark to obtain UV dual-curing ink.

[0053] Example 2, as Figure 1 As shown, according to the invention, a UV dual-curing ink is prepared from the following materials by weight: 15% UV polyester acrylate, 15% polyurethane or acrylate containing spiropyran groups, 25% UV-modified epoxy acrylate, 15% POSS-acrylate, 16% mixed solvent, 7% photoinitiator, 4% active amine, 0.4% leveling agent, 2% pigment, and 0.6% dispersant; the hydroxyl value of the acrylate in the UV polyester acrylate is 60±5 mg KOH / g; the epoxy equivalent of the UV-modified epoxy acrylate is 500 g / mol.

[0054] The pigments are inorganic pigments: titanium blue, permanent red, and permanent yellow, as well as upconversion fluorescent nanoparticles.

[0055] The leveling agent is perfluorobutyl ethyl acrylate; the photoinitiator is 1-hydroxycyclohexylphenyl ketone and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl] ethyl ketone 1-(O-acetyl oxime);

[0056] The active amine is triethanolamine; the mixed solvent is composed of ethyl acetate, butyl acetate, and PMA propylene glycol monomethyl ether acetate in a mass ratio of 1:8:13.

[0057] A method for preparing a UV dual-curing ink according to an embodiment of the present invention includes the following steps:

[0058] Raw material weighing: Weigh the following raw materials according to the mass ratio: 15% UV polyester acrylate, 15% polyurethane or acrylate containing spiropyran groups, 25% UV modified epoxy acrylate, 15% POSS-acrylate, 16% mixed solvent, 7% photoinitiator, 4% active amine, 0.4% leveling agent, 2% pigment, and 0.6% dispersant;

[0059] Premixing treatment: POSS-acrylate is heated to 70℃ and the viscosity of POSS-acrylate is controlled at 510 mPa·s. Then UV-modified epoxy acrylate is added and premixed for 30 min to obtain epoxy acrylate premix; polyurethane containing spiropyran groups or acrylate containing spiropyran groups is mixed with UV polyester acrylate at 45℃ for 20 min to obtain polyester acrylate premix.

[0060] Dispersion treatment: Take a mixed solvent with a weight ratio of 65% and the dispersant and pigment, mix and grind into a powder of 450nm, then add the nano powder fines to the epoxy acrylate premix and mix evenly. Add the polyester acrylate premix at a rate of less than or equal to 5mL / min and mix and stir. At the same time, apply a magnetic field of 1000Gs to promote the directional arrangement and mixing of POSS-acrylate to obtain the dispersion system.

[0061] Functionalization process: Mix the remaining mixed solvent with a portion of the photoinitiator evenly, then heat to 85°C, and then add the dispersant system, active amine, and leveling agent in sequence and mix for 30 minutes. After ultrasonic oscillation and dispersion for 10 minutes, add the remaining photoinitiator under light-protected conditions and stir evenly. Then, seal and store in the dark to obtain UV dual-curing ink.

[0062] Example 3, as Figure 1 As shown, according to the invention, a UV dual-curing ink is prepared from the following materials by weight: 18% UV polyester acrylate, 12% polyurethane containing spiropyran groups or acrylate containing spiropyran groups, 16% UV-modified epoxy acrylate, 10% POSS-acrylate, 24% mixed solvent, 5% photoinitiator, 6% active amine, 0.5% leveling agent, 6% pigment, and 2.5% dispersant; the hydroxyl value of the acrylate in the UV polyester acrylate is 60±5 mg KOH / g; the epoxy equivalent of the UV-modified epoxy acrylate is 480 g / mol.

[0063] The pigments are inorganic pigments carbon black, inorganic permanent yellow, and upconversion fluorescent nanoparticles;

[0064] The leveling agent is a polyether-modified siloxane polymer; the photoinitiator is 1-hydroxycyclohexylphenyl ketone, TPO, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide;

[0065] The active amine is N-methyldiethanolamine or triethanolamine; the mixed solvent is composed of ethyl acetate, butyl acetate, and PMA propylene glycol monomethyl ether acetate in a mass ratio of 1:5:10.

[0066] According to another aspect of the present invention, the present invention provides a method for preparing a UV dual-curing ink, the method comprising the following steps:

[0067] Raw material weighing: Weigh the following raw materials according to the mass ratio: 18% UV polyester acrylate, 12% polyurethane containing spiropyran groups or containing spiropyran groups, 16% UV modified epoxy acrylate, 10% POSS-acrylate, 24% mixed solvent, 5% photoinitiator, 6% active amine, 0.5% leveling agent, 6% pigment, and 2.5% dispersant;

[0068] Premixing treatment: POSS-acrylate is heated to 60℃ and its viscosity is controlled at 460mPa·s. Then, UV-modified epoxy acrylate is added and premixed for 30min to obtain epoxy acrylate premix; polyurethane containing spiropyran groups or acrylate containing spiropyran groups is mixed with UV polyester acrylate at 40℃ for 25min to obtain polyester acrylate premix.

[0069] Dispersion treatment: Take 60% by weight of mixed solvent, dispersant and pigment, mix and grind into 300-350nm powder, then add the nano powder to epoxy acrylate premix and mix evenly. Add polyester acrylate premix at a rate of less than or equal to 5mL / min and mix and stir. At the same time, apply a 700Gs magnetic field to promote the directional mixing of POSS-acrylate to obtain the dispersion system.

[0070] Functionalization process: Mix the remaining 40% by weight of the mixed solvent with a portion of the photoinitiator until homogeneous. Then heat to 83°C and add the dispersant system, active amine, and leveling agent in sequence. Mix and stir for 30 minutes. Then disperse using ultrasonic vibration for 10 minutes. Add the remaining photoinitiator under light-protected conditions and stir until homogeneous. Store in the dark to obtain UV dual-curing ink.

[0071] Example 4, as Figure 1 As shown, according to the invention, a UV dual-curing ink is prepared from the following materials by weight: 15% UV polyester acrylate, 16% polyurethane containing spiropyran groups or acrylate containing spiropyran groups, 18% UV-modified epoxy acrylate, 11% POSS-acrylate, 20% mixed solvent, 3% photoinitiator, 8% active amine, 1% leveling agent, 7% pigment, and 1% dispersant; the hydroxyl value of the acrylate in the UV polyester acrylate is 60±5 mgKOH / g; the epoxy equivalent of the UV-modified epoxy acrylate is 490 g / mol.

[0072] The pigments are inorganic pigment carbon black, inorganic pigment titanium cyan blue, inorganic pigment permanent red and up-conversion fluorescent nanoparticles;

[0073] The leveling agent is composed of polyether-modified siloxane polymer and perfluorobutyl ethyl acrylate with a mass ratio of 1:3; the photoinitiator is one or more of TPO, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyloxime); the active amine is composed of N-methyldiethanolamine and triethanol ethylamine with a mass ratio of 1:0.8~1.2; the mixed solvent is composed of ethyl acetate, butyl acetate and PMA propylene glycol monomethyl ether acetate with a mass ratio of 1:6:12.

[0074] According to another aspect of the present application, the present application provides a preparation method of UV dual-curing ink, the preparation method comprising the following steps:

[0075] Raw materials are weighed: the following raw materials are weighed according to the mass ratio: UV polyester acrylate 15%, polyurethane containing spiropyran groups or acrylate containing spiropyran groups 16%, UV modified epoxy acrylate 18%, POSS-acrylate 11%, mixed solvent 20%, photoinitiator 3%, active amine 8%, leveling agent 1%, pigment 7%, dispersant 1%;

[0076] Premixing treatment: the POSS-acrylate is heated to 65℃, and the viscosity of the POSS-acrylate is controlled at 450±60 mPa·s, then the UV modified epoxy acrylate is added for premixing for 30 min to obtain an epoxy acrylate premix; the polyurethane containing spiropyran groups or the acrylate containing spiropyran groups is mixed with the UV polyester acrylate at 45℃ for 25 min to obtain a polyester acrylate premix;

[0077] Dispersion treatment: the mixed solvent with a weight ratio of 60% is mixed and ground with the dispersant and the pigment to form a powder material with a particle size of 360-420 nm, then the nanopowder material is added to the epoxy acrylate premix and mixed uniformly, the polyester acrylate premix is added at a rate of less than or equal to 5 mL / min for mixing and stirring, and a magnetic field of 600-800 Gs is applied to promote the directional arrangement and mixing of the POSS-acrylate, to obtain a dispersion system;

[0078] Functionalization treatment: the mixed solvent with a remaining weight ratio of 40% is mixed uniformly with part of the photoinitiator, then heated to 82℃, and then the dispersion system, the active amine and the leveling agent are added in sequence for mixing and stirring for 30 min, then ultrasonic oscillation dispersion is performed for 10 min, then the remaining photoinitiator is added under light shielding conditions and stirred uniformly, and then the UV dual-curing ink is obtained by light shielding and storage.

[0079] The UV dual-curing ink prepared by the embodiment of the present application is uniformly coated on a PET film substrate, and then dried and cured by ultraviolet light, so that the dry film thickness of the ink layer on the surface of the PET substrate reaches 10-20 µm; then, three-ling pencil test, THB test verification for 500H, PCT aging test, QUV aging test are carried out in sequence, the UV curing ink formula of the present application has superior transparency, and the adhesion to the PET substrate reaches 5B requirement, and the test results are shown in Table 1:

[0080] Table 1: Test results table

[0081]

[0082] The test results in Table 1 show that the UV dual-curing ink of the present application has high hardness and scratch resistance, and the PET film is not easy to crack, and has good optical performance. After the PET film is boiled in water for 2 hours and soaked at room temperature for 2 hours, the 2H adhesion does not change, and the surface does not turn white,

[0083] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A UV dual-cure ink, characterized in that: The UV dual-curing ink is prepared from the following materials by mass fraction: UV-cured polyester acrylate 15-25%, polyurethane containing spiropyran groups or acrylate containing spiropyran groups 10-16%; UV-modified epoxy acrylate 16-25%, POSS-acrylate 10-15%; The mixed solvent comprises 16-24% and the photoinitiator comprises 3-7%; the mixed solvent is composed of ethyl acetate, butyl acetate, and PMA propylene glycol monomethyl ether acetate in a mass ratio of 1:5-8:9-13. Active amine 4-8%, leveling agent 0.4-1%; Pigment 2-7%, dispersant 0.6-2.5%; The pigment is one or more of the following: inorganic pigment carbon black, inorganic pigment titanium blue, inorganic pigment permanent red, inorganic permanent yellow, and upconversion fluorescent nanoparticles; the leveling agent is a polyether-modified siloxane polymer or perfluorobutyl ethyl acrylate; the photoinitiator is 1-hydroxycyclohexylphenyl ketone, TPO, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, or 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]acetone-1-(O-acetyl oxime); and the active amine is N-methyldiethanolamine.

2. The UV dual-curable ink according to claim 1, characterized in that: The UV dual-curing ink is prepared from the following materials by mass fraction: 18% UV-cured polyester acrylate, 12% polyurethane containing spiropyran groups or acrylate containing spiropyran groups; 16% UV-modified epoxy acrylate, 10% POSS-acrylate; Mixed solvent 24%, photoinitiator 5%; Active amine 6%, leveling agent 0.5%; Pigment 6%, dispersant 2.5%.

3. The UV dual-curable ink according to claim 1, characterized in that: The upconversion fluorescent nanoparticles are NaYF4:Yb 3+ / Er 3+ @SiO2 nanocore-shell structure material, the nanocore-shell particle size is 50-150 nm, and the core-shell thickness is 5 nm-15 nm.

4. The UV dual-curable ink according to claim 1 or 2, characterized in that: The acrylate hydroxyl value in the UV-modified polyester acrylate is 60±5 mg KOH / g; the epoxy equivalent of the UV-modified epoxy acrylate is 450-500 g / mol.

5. A process for the preparation of a UV dual-cure ink according to any one of claims 1 to 4, characterized in that, The preparation method includes the following steps: Premixing treatment: POSS-acrylate is heated to 55℃-70℃, and then UV-modified epoxy acrylate is added and premixed for 30 min to obtain epoxy acrylate premix; polyurethane containing spiropyran groups or acrylate containing spiropyran groups is mixed with UV polyester acrylate at 35℃-45℃ for 20 min-30 min to obtain polyester acrylate premix. Dispersion treatment: Take a certain amount of mixed solvent, dispersant and pigment, mix and grind into nano powder fines, add nano powder fines to epoxy acrylate premix and mix evenly, then add polyester acrylate premix at a rate of less than or equal to 5 mL / min and mix and stir to obtain the dispersion system mixture. Functionalization process: Mix the remaining mixed solvent with a portion of the photoinitiator evenly, then heat to 80-85℃, and then add the dispersion system mixture, active amine and leveling agent in sequence and mix for 30 minutes. After ultrasonic oscillation and dispersion for 10 minutes, add the remaining photoinitiator under light-protected conditions and stir evenly. Then seal and store in the dark to obtain UV dual-curing ink.

6. The method for preparing a UV dual-curing ink according to claim 5, characterized in that, In the step of dispersion processing, the particle size of the mixed and ground nano-powder fine material is 280-450 nm, and the polyester acrylate premix is added at a rate of less than or equal to 5 mL / min for mixing and stirring, and a magnetic field of 500-1000 Gs is applied.

7. The method for preparing a UV dual-curing ink according to claim 5, characterized in that, When the POSS-acrylate is heated to 55-70°C, the viscosity of the POSS-acrylate is controlled at 450±60 mPa·s.

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