A high-temperature resistant insulating ink for solvent-free inkjet 3D printing, its preparation method and application

Abstract

The present invention provides a high-temperature-resistant insulating ink for solvent-free inkjet 3D printing, its preparation method, and application, and relates to the technical field of high-performance inkjet 3D printing materials. The high-temperature-resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention comprises the following components by weight: 40-60 parts of a cyanate precursor, 20-30 parts of a diluent monomer, 5-20 parts of a cross-linking agent, 5-8 parts of a photoinitiator, and 1-5 parts of an auxiliary agent. Based on the requirements of inkjet 3D printing technology for material viscosity and surface tension, the present invention designs a low-viscosity (<20.5 cps) and low-surface-tension (<40 mN / m) inkjet 3D printing solvent-free ink system based on a cyanate precursor. After inkjet 3D printing, UV curing, and thermal curing, the ink can produce inkjet 3D printed devices with high heat resistance, high insulation, and high strength, which has important engineering application value in the integrated preparation of electronic devices.

Description

Technical Field

[0001] The present invention relates to the technical field of high-performance inkjet 3D printing materials, and in particular to a high-temperature resistant insulating ink for solvent-free inkjet 3D printing, and a preparation method and application thereof. Background Art

[0002] In recent years, new electronic devices have placed new demands on insulating materials for high performance, high heat resistance, high insulation, and high-density fabrication. Compared to the high cost and energy consumption of traditional vacuum lithography, inkjet 3D printing technology, with its advantages of high material utilization, customized design, high patterning accuracy, and low cost, has become highly competitive in the manufacture of microelectronic circuits and their functional components. Insulating inks are fundamental to the performance of printed electronic devices. The development of various high-performance functional insulating ink materials has attracted widespread attention and holds enormous potential for development.

[0003] Existing inkjet 3D printing insulation inks, due to the limitations of inkjet printing equipment on ink viscosity and surface tension, are mostly concentrated in ink systems composed of acrylic, polyurethane, and epoxy resins. The resulting materials after inkjet printing and UV curing exhibit low heat resistance and mechanical strength, as well as high dielectric constant and dielectric loss, and cannot meet the technical requirements of aerospace, microelectronics manufacturing, and other fields for high heat resistance, high insulation, and high mechanical strength. Therefore, the development of solvent-free inkjet 3D printing insulation inks with high heat resistance, high insulation, and high strength is crucial and directly affects their practical application. Summary of the Invention

[0004] In view of this, the present invention aims to provide a high-temperature-resistant insulating ink for solvent-free inkjet 3D printing, as well as its preparation method and application. The high-temperature-resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention can produce printed devices with high heat resistance, high insulation, and high strength after inkjet 3D printing, UV curing, and thermal curing.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a high-temperature resistant insulating ink for solvent-free inkjet 3D printing, comprising the following components in parts by weight: 40 to 60 parts of a cyanate precursor, 20 to 30 parts of a diluent monomer, 5 to 20 parts of a cross-linking agent, 5 to 8 parts of a photoinitiator, and 1 to 5 parts of an auxiliary agent;

[0007] The cyanate precursor is one or more of bisphenol A cyanate, bisphenol E cyanate, 1,6-hexamethylene diisocyanate, 4,4-diisocyanate dicyclohexylmethane, dicyclopentadiene cyanate, tris(4-phenylisocyanate)thiophosphate, toluene diisocyanate and bis(4-isocyanatephenyl)methane;

[0008] The diluent monomer is one or more of 3,3,5-trimethylcyclohexyl acrylate, ethyl isocyanate methacrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, glycidyl methacrylate, dicyclopentenyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acryloylmorpholine, isobornyl acrylate, dimethylacrylamide, vinyl pyrrolidone, vinyl formamide, vinyl acetamide and caprolactone acrylate;

[0009] The crosslinking agent is one or more of ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, di-pentaerythritol hexaacrylate and propoxylated glycerol triacrylate.

[0010] Preferably, the photoinitiator is one or more of trimethylbenzoyldiphenylphosphine oxide, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-isopropylthioxanthone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0011] Preferably, the auxiliary agent is one or more of a leveling agent, a defoaming agent and a wetting agent.

[0012] Preferably, the high-temperature resistant insulating ink for solvent-free inkjet 3D printing has a viscosity of 5 to 40 cps at 25° C. and a surface tension of 10 to 50 mN / m.

[0013] The present invention provides a method for preparing the high-temperature resistant insulating ink for solvent-free inkjet 3D printing described in the above technical solution, comprising the following steps:

[0014] The cyanate precursor, the diluent monomer, the cross-linking agent, the photoinitiator and the auxiliary agent are mixed to obtain the high-temperature resistant insulating ink for solvent-free inkjet 3D printing.

[0015] The present invention provides the application of the high-temperature resistant insulating ink for solvent-free inkjet 3D printing described in the above technical solution in the integrated preparation of electronic devices.

[0016] The present invention provides a method for preparing an inkjet 3D printing device, comprising the following steps:

[0017] The solvent-free inkjet 3D printing high-temperature resistant insulating ink described in the above technical solution is subjected to inkjet 3D printing and UV pre-curing to obtain a preformed device;

[0018] The preformed device is thermally cured to obtain the inkjet 3D printed device.

[0019] Preferably, the UV pre-curing has a curing wavelength of 355 to 405 nm and a curing power of 500 to 5000 mW.

[0020] Preferably, the thermal curing includes a first thermal curing, a second thermal curing, a third thermal curing, a fourth thermal curing and a fifth thermal curing performed in sequence, wherein the temperature of the first thermal curing is 80-100°C and the holding time is 1-2 hours, the temperature of the second thermal curing is 120-140°C and the holding time is 1-2 hours, the temperature of the third thermal curing is 150-160°C and the holding time is 1-2 hours, the temperature of the fourth thermal curing is 180-200°C and the holding time is 1-2 hours, and the temperature of the fifth thermal curing is 220-240°C and the holding time is 2 hours.

[0021] Preferably, the thermal curing is performed in a vacuum, nitrogen or argon atmosphere.

[0022] The present invention provides a high-temperature resistant insulating ink for solvent-free inkjet 3D printing, comprising the following components in parts by mass: 40 to 60 parts of a cyanate precursor, 20 to 30 parts of a diluent monomer, 5 to 20 parts of a cross-linking agent, 5 to 8 parts of a photoinitiator, and 1 to 5 parts of an auxiliary agent; the cyanate precursor is one or more of bisphenol A cyanate, bisphenol E cyanate, 1,6-hexamethylene diisocyanate, 4,4-diisocyanate dicyclohexylmethane, dicyclopentadiene cyanate, tris(4-phenylisocyanate)thiophosphate, toluene diisocyanate, and bis(4-isocyanatephenyl)methane; the diluent monomer is 3,3,5-triisocyanate. One or more of methylcyclohexyl acrylate, isocyanatoethyl methacrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, glycidyl methacrylate, dicyclopentenyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acryloylmorpholine, isobornyl acrylate, dimethylacrylamide, vinylpyrrolidone, vinylformamide, vinylacetamide, and caprolactone acrylate; the crosslinking agent is one or more of ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, bis-pentaerythritol hexaacrylate, and propoxylated glycerol triacrylate. Compared with the prior art, the present invention has the following beneficial effects:

[0023] Based on the material viscosity and surface tension requirements of inkjet 3D printing technology, the present invention designs a low-viscosity, low-surface-tension, solvent-free ink system for inkjet 3D printing based on a cyanate ester precursor. Simultaneously, to preserve the excellent insulation and heat resistance properties of the cyanate ester itself, the present invention employs a photothermal dual-curing strategy for high-performance ink design. By introducing a diluent and a crosslinker with strong dilution and UV crosslinking properties into the ink system, the ink is preformed via inkjet 3D printing and UV curing. The unique high-temperature crosslinking network structure of the cyanate ester's cyanate-based groups ultimately yields an inkjet 3D-printed device with high heat resistance, high insulation, and high strength. By designing an insulating ink for inkjet 3D printing based on a cyanate ester precursor, the present invention achieves a photosensitive insulating ink suitable for inkjet 3D printing with low viscosity, low surface tension, excellent high-temperature resistance, and low dielectric properties. This addresses key technical challenges of existing insulating materials for inkjet 3D printing, such as poor heat resistance, poor insulation, low strength, and unstable printing.

[0024] The results of the examples show that the high-temperature resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention has low viscosity (<20.5cps), low surface tension (<40mN / m), and after dual photothermal curing, it has a high heat deformation temperature (150-250°C), a low dielectric constant (frequency 18GHz: 2.4-3.3), high mechanical strength (60-100MPa) and low shrinkage (<3%). BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a display piece printed with high-temperature resistant insulating ink using inkjet 3D printing in Example 1. Figure 1 The middle left picture shows the sample after inkjet 3D printing and UV pre-curing, and the right picture shows the sample after high-temperature heat curing;

[0026] Figure 2 The conductive circuit device printed by inkjet 3D printing of high temperature resistant insulating ink in Example 2, Figure 2 The middle left and right images are electronic device images of devices with different shapes printed on the surface of nanosilver conductive circuits after insulating ink printing and heat curing.

[0027] Figure 3 This is a printed display piece of the high-temperature resistant insulating ink of Example 3 after inkjet 3D printing. DETAILED DESCRIPTION

[0028] The present invention provides a high-temperature resistant insulating ink for solvent-free inkjet 3D printing, comprising the following components in parts by weight: 40 to 60 parts of a cyanate precursor, 20 to 30 parts of a diluent monomer, 5 to 20 parts of a cross-linking agent, 5 to 8 parts of a photoinitiator, and 1 to 5 parts of an auxiliary agent;

[0029] The cyanate precursor is one or more of bisphenol A cyanate, bisphenol E cyanate, 1,6-hexamethylene diisocyanate, 4,4-diisocyanate dicyclohexylmethane, dicyclopentadiene cyanate, tris(4-phenylisocyanate)thiophosphate, toluene diisocyanate and bis(4-isocyanatephenyl)methane;

[0030] The diluent monomer is one or more of 3,3,5-trimethylcyclohexyl acrylate, ethyl isocyanate methacrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, glyceryl methacrylate, dicyclopentenyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acryloylmorpholine, isobornyl acrylate, dimethylacrylamide, vinyl pyrrolidone, vinyl formamide, vinyl acetamide and caprolactone acrylate;

[0031] The crosslinking agent is one or more of ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, di-pentaerythritol hexaacrylate and propoxylated glycerol triacrylate.

[0032] In parts by mass, the high temperature resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention includes 40 to 60 parts of cyanate precursors, preferably 45 to 55 parts, and more preferably 45 to 50 parts. In the present invention, the cyanate precursor is one or more of bisphenol A cyanate, bisphenol E cyanate, 1,6-hexamethylene diisocyanate, 4,4-diisocyanate dicyclohexylmethane, dicyclopentadiene cyanate, tris(4-phenylisocyanate)thiophosphate, toluene diisocyanate and bis(4-isocyanate phenyl) methane, and the cyanate precursor is liquid at room temperature and has low viscosity and low surface tension at room temperature. In the present invention, the cyanate precursor is preferably one or more of bisphenol E cyanate, 1,6-hexamethylene diisocyanate and toluene diisocyanate with lower viscosity, more preferably 1,6-hexamethylene diisocyanate and / or toluene diisocyanate.

[0033] Cyanate ester resins undergo a cyclotrimerization reaction to form a highly cross-linked network structure containing triazole rings. Cyanate ester resins are a type of thermosetting resin with -OCN functional groups at their end groups. They exhibit low dielectric constant, low dielectric loss, low moisture absorption, low volume shrinkage, and excellent heat resistance. They meet the performance requirements of printed circuit boards and insulating substrates for the compact, lightweight, high-speed, and high-performance development of modern high-frequency communication products. These resins exhibit: 1) a low and stable dielectric constant; 2) a low dielectric loss factor; 3) a thermal expansion coefficient consistent with that of copper foil; 4) low water absorption; 5) chemical resistance; and excellent heat resistance, impact strength, and adhesion to copper foil. Compared to traditional epoxy and bismaleimide resins used as PCB substrates, cyanate ester resins offer significant performance advantages, meeting the high-performance requirements of resin substrates for future high-performance PCBs. Characteristics of cyanate esters: Cyanate esters have excellent high-temperature mechanical properties, with higher flexural strength and tensile strength than bifunctional epoxy resins; extremely low water absorption (<1.5%); low molding shrinkage and good dimensional stability; good heat resistance, with a glass transition temperature of 240-260°C and a maximum of 400°C; excellent moisture and heat resistance, flame retardancy, and adhesion, and good bonding properties with reinforcing materials such as glass fiber, carbon fiber, quartz fiber, and whiskers; excellent electrical properties, with extremely low dielectric constants (2.8-3.2) and dielectric loss tangent values (0.002-0.008), and the dielectric properties show unique stability to changes in temperature and electromagnetic wave frequency (i.e., broadband).

[0034] Based on the mass fraction of the cyanate precursor, the high-temperature resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention includes 20 to 30 parts of a diluent monomer, preferably 25 to 30 parts. In the present invention, the diluent monomer is one or more of 3,3,5-trimethylcyclohexyl acrylate, isocyanateethyl methacrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, glycidyl methacrylate, dicyclopentenyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acryloylmorpholine, isobornyl acrylate, dimethylacrylamide, vinyl pyrrolidone, vinyl formamide, vinyl acetamide and caprolactone acrylate, preferably one or more of isocyanateethyl methacrylate, 4-hydroxybutyl acrylate, glycidyl methacrylate, hydroxyethyl methacrylate, dimethylacrylamide, vinyl pyrrolidone, vinyl formamide and vinyl acetamide with lower viscosity, more preferably one or more of isocyanateethyl methacrylate, 4-hydroxybutyl acrylate, glycidyl methacrylate and hydroxyethyl methacrylate with lower viscosity and having active groups (such as hydroxyl, epoxy, isocyanate, etc.), further preferably isocyanateethyl methacrylate and / or 4-hydroxybutyl acrylate.

[0035] The high-temperature-resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention includes 5 to 20 parts, preferably 5 to 10 parts, of a crosslinker, based on the mass fraction of the cyanate precursor. In the present invention, the crosslinker is one or more of ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, and propoxylated glycerol triacrylate, preferably trimethylolpropane triacrylate and / or pentaerythritol triacrylate, which have lower surface tension and lower viscosity, and more preferably trimethylolpropane triacrylate.

[0036] Based on the mass fraction of the cyanate precursor, the high-temperature resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention includes 5 to 8 parts of a photoinitiator, preferably 5.5 to 7 parts. In the present invention, the photoinitiator is preferably one or more of trimethylbenzoyldiphenylphosphine oxide, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-isopropylthioxanthone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, more preferably one or more of trimethylbenzoyldiphenylphosphine oxide, 1-hydroxy-cyclohexyl-phenyl ketone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which are more active and exhibit antioxidant properties. The present invention controls the amount of the photoinitiator at a relatively high level, which is beneficial for the surface of the printed layer to have good curing and surface drying properties during UV curing of inkjet 3D printing, without generating surface oxygen resistance, and at the same time improving the molding accuracy and dimensional stability of the printed layer thickness, thereby ensuring the interlayer bonding, good surface quality and molding accuracy of the inkjet 3D printed parts.

[0037] The solvent-free inkjet 3D printing high-temperature resistant insulating ink provided by the present invention includes 1 to 5 parts, preferably 1 to 2 parts, of an additive, based on the mass fraction of the cyanate precursor. In the present invention, the additive is preferably one or more of a leveling agent, a defoaming agent, and a wetting agent. The present invention has no particular requirements for these agents; any leveling agent, defoaming agent, and wetting agent familiar to those skilled in the art may be used.

[0038] In the present invention, the viscosity of the high-temperature resistant insulating ink for solvent-free inkjet 3D printing at 25°C is 5 to 40 cps, preferably 5 to 30 cps, more preferably 5 to 20.5 cps, and the surface tension is 10 to 50 mN / m, preferably 20 to 40 mN / m, more preferably 30 to 40 mN / m.

[0039] The present invention provides a solvent-free, pure resin, low-viscosity, low-surface-tension ink system that fully complies with and meets the physical and chemical plating property requirements of printing inks for inkjet 3D printing equipment. It has high printing accuracy and molding stability. Compared with commercial inkjet 3D printing inks, it has excellent heat resistance, high strength, low shrinkage, and low dielectric constant.

[0040] While photocurable 3D printing technology based on cyanate ester resins currently exists, existing cyanate ester resin inks have high viscosity, high surface tension, and poor photosensitivity. Furthermore, existing photocurable 3D printing technology involves extruding the printing ink through a build platform and a separator to a defined layer thickness, followed by UV exposure to cure the desired pattern. Layer by layer, the ink is then bonded and stacked to form the final 3D printed part. During the molding process, the ink cures in a closed, oxygen-free environment, eliminating the issue of surface oxygen resistance during ink curing. In contrast, inkjet 3D printing involves spraying the ink onto the build platform in the desired pattern. The ink and its surface are exposed to oxygen, then UV-cured to form a defined layer thickness. Multiple layers of inkjet and exposure cure the ink, ultimately achieving the desired three-dimensional component fabrication. The two technologies contrast in their molding principles: inkjet 3D printing ink cures in an oxygen environment, resulting in an oxygen barrier effect during UV curing. To achieve high-precision printing with good interlayer bonding, the ink's oxygen barrier properties must be addressed. In summary, how to achieve low viscosity, low surface tension, high photosensitivity and antioxidant properties of cyanate ester resin systems has become a key technical challenge in their application and development in the field of inkjet 3D printing. The present invention innovatively adopts a photothermal dual curing strategy to design a solvent-free system for inkjet 3D printing of high heat-resistant insulating ink. Through the composition design and optimization of the ink system, a cyanate precursor with low viscosity and low surface tension at room temperature is screened and optimized as the matrix resin and a thermal curing cross-linking structure is introduced. A diluent monomer and a cross-linking agent with active reactive groups and ultra-low viscosity (less than 10 cPs) are used as active ingredients of the ink with high photosensitivity and an ultraviolet light curing cross-linking structure is introduced. Under the dual action of light and heat, an interpenetrating network structure with a dual cross-linking structure of a photocross-linking network structure and a cyanate thermal cross-linking network structure is formed, thereby greatly improving the comprehensive performance of the insulating and high-temperature resistant ink system, especially the insulation and heat resistance; in this way, a high-performance insulating ink with low viscosity, low surface tension, high photosensitivity and anti-oxygen resistance suitable for inkjet 3D printing is designed, and the ink can realize the integrated manufacturing of high insulation, low dielectric, high heat resistance, and high strength and high modulus inkjet 3D printing devices.

[0041] The present invention provides a method for preparing the high-temperature resistant insulating ink for solvent-free inkjet 3D printing described in the above technical solution, comprising the following steps:

[0042] The cyanate precursor, the diluent monomer, the cross-linking agent, the photoinitiator and the auxiliary agent are mixed to obtain the high-temperature resistant insulating ink for solvent-free inkjet 3D printing.

[0043] The present invention has no special requirements for the mixing method, as long as the components are uniformly mixed, such as mechanical stirring mixing or ball milling mixing.

[0044] The present invention provides the application of the high-temperature-resistant insulating ink for solvent-free inkjet 3D printing described in the above technical solution in the integrated production of electronic devices. The high-temperature-resistant insulating ink for solvent-free inkjet 3D printing provided by the present invention has the advantages of being solvent-free, readily available raw materials, easy to industrialize, and having high overall performance. It can effectively address the technical shortcomings of existing commercial inkjet 3D printing inks, such as poor temperature resistance, poor insulation, and insufficient strength. It has important engineering application value in the integrated production of functionally customized electronic devices such as microelectronic circuits, composite multi-layer circuit boards for aerospace applications, high-temperature sensor substrates, 3D structured electronic substrates, and antenna substrates.

[0045] The present invention provides a method for preparing an inkjet 3D printing device, comprising the following steps:

[0046] The solvent-free inkjet 3D printing high-temperature resistant insulating ink described in the above technical solution is subjected to inkjet 3D printing and UV pre-curing to obtain a preformed device;

[0047] The preformed device is thermally cured to obtain the inkjet 3D printed device.

[0048] The present invention has no special requirements for the inkjet 3D printing equipment, and a commercial inkjet 3D printer well known to those skilled in the art can be used.

[0049] The present invention performs UV pre-curing during inkjet 3D printing, thereby ensuring high-precision molding. In the present invention, the UV pre-curing wavelength is preferably 355-405nm, more preferably 380-405nm, and the curing power is preferably 500-5000mW, more preferably 1500-3000mW.

[0050] In the present invention, the thermal curing includes a first thermal curing, a second thermal curing, a third thermal curing, a fourth thermal curing and a fifth thermal curing carried out in sequence. The temperature of the first thermal curing is preferably 80-100°C, and the holding time is preferably 1-2 hours. The temperature of the second thermal curing is preferably 120-140°C, and the holding time is preferably 1-2 hours. The temperature of the third thermal curing is preferably 150-160°C, and the holding time is preferably 1-2 hours. The temperature of the fourth thermal curing is preferably 180-200°C, and the holding time is preferably 1-2 hours. The temperature of the fifth thermal curing is preferably 220-240°C, and the holding time is preferably 2 hours. In the present invention, the thermal curing is preferably carried out in a vacuum, nitrogen or argon atmosphere. The present invention can ensure that the inkjet-printed device is not prone to defects such as warping, deformation, and cracking through staged temperature increase curing, thereby ensuring the accuracy, dimensional stability and formability of the printed device.

[0051] The present invention uses a two-step photothermal curing method to achieve integrated rapid prototyping of inkjet 3D printing devices with high heat resistance, high insulation and high strength.

[0052] To further illustrate the present invention, the high-temperature resistant insulating ink for solvent-free inkjet 3D printing, its preparation method, and application provided by the present invention are described in detail below with reference to examples, but they should not be understood as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] A low-viscosity insulating ink suitable for inkjet 3D printing was prepared by mixing 55 parts by weight of bisphenol E cyanate, 20 parts by weight of acryloylmorpholine, 10 parts by weight of glycidyl methacrylate, 10 parts by weight of trimethylolpropane triacrylate, 1 part by weight of the defoamer BYK-1709, and 6 parts by weight of the photoinitiator trimethylbenzoyldiphenylphosphine oxide with vigorous mechanical stirring for 5 hours. The prepared insulating ink was then printed and pre-cured with UV light (405 nm wavelength, 2000 mW power) using a commercial inkjet 3D printer to produce test and demonstration parts. Finally, the printed, photocured parts were thermally cured in a vacuum oven at 80°C for 1 hour, 120°C for 1 hour, 160°C for 1 hour, 180°C for 1 hour, and 220°C for 2 hours to produce a high-performance inkjet-printed device with an interpenetrating photo-thermal dual cross-linked network structure. The performance data of the inkjet insulating ink of Example 1 are shown in Table 1.

[0055] Example 2

[0056] A low-viscosity insulating ink suitable for inkjet 3D printing was prepared by mixing 45 parts by weight of bisphenol A cyanate, 10 parts by weight of hydroxyethyl acrylate, 20 parts by weight of glycidyl methacrylate, 10 parts by weight of propoxylated glycerol triacrylate, 1 part by weight of a wetting agent, BYK-9077, and 7 parts by weight of a photoinitiator, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, with vigorous mechanical stirring for 6 hours. The prepared insulating ink was then printed and pre-cured with UV light (405 nm wavelength, 2000 mW power) using a commercial inkjet 3D printer to form test and demonstration parts. Finally, the printed, photocured parts were thermally cured in a vacuum oven at 90°C for 1 hour, 140°C for 1 hour, 160°C for 1 hour, 200°C for 1 hour, and 240°C for 2 hours, resulting in a high-performance inkjet-printed device with an interpenetrating photo-thermal dual cross-linked network structure. The performance data of the inkjet insulating ink of Example 2 are shown in Table 1.

[0057] Example 3

[0058] 35 parts by mass of dicyclopentadiene cyanate, 15 parts by mass of bis(4-isocyanatophenyl)methane, 20 parts by mass of ethyl isocyanate methacrylate, 5 parts by mass of acryloylmorpholine, 5 parts by mass of bis-pentaerythritol hexaacrylate, 1 part by mass of leveling agent BYK-354, and 5.5 parts by mass of photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were mechanically stirred and mixed for 5 hours to prepare a low-viscosity insulating ink suitable for inkjet 3D printing. The prepared inkjet-printable insulating ink was then printed and pre-cured with UV light (wavelength 405nm, power 2000mW) using a commercial inkjet 3D printer to form test pieces and display pieces. Finally, the printed, photocured part was placed in a vacuum oven for thermal curing at 80°C for 1 hour, 120°C for 1 hour, 160°C for 2 hours, 180°C for 1 hour, and 220°C for 2 hours. This yielded a high-performance inkjet-printed device with an interpenetrating, photo-double-crosslinked network structure. The performance data of the inkjet insulating ink of Example 3 are shown in Table 1.

[0059] Example 4

[0060] A low-viscosity insulating ink suitable for inkjet 3D printing was prepared by mixing 40 parts by mass of bisphenol E cyanate, 20 parts by mass of tris(4-phenylisocyanate)thiophosphate, 5 parts by mass of dicyclopentenyl acrylate, 25 parts by mass of vinyl formamide, 5 parts by mass of pentaerythritol triacrylate, 1 part by mass of the wetting agent BYK-W940, 2 parts by mass of the photoinitiator trimethylbenzoyldiphenylphosphine oxide, and 5 parts by mass of 1-hydroxy-cyclohexyl-phenyl ketone. The mixture was mechanically stirred for 6 hours to prepare a low-viscosity insulating ink suitable for inkjet 3D printing. The prepared insulating ink was then printed and pre-cured with UV light (wavelength 405nm, power 2000mW) using a commercial inkjet 3D printer to form test pieces and display pieces. Finally, the printed, photocured part was placed in a vacuum oven for thermal curing at 80°C for 2 hours, 120°C for 1 hour, 160°C for 1 hour, 180°C for 1 hour, and 220°C for 2 hours. This yielded a high-performance inkjet-printed device with a dual photo-thermal crosslinked network structure. The performance data for the inkjet-printed insulating ink of Example 4 are shown in Table 1.

[0061] Table 1 Performance data of inkjet 3D printing insulation ink in Example

[0062]

[0063]

[0064] In Table 1, the ink viscosity was tested using a digital viscometer at 25°C. The ink surface tension was tested using a surface tensiometer at 25°C in accordance with GB / T 5549-1990. The heat deflection temperature was tested according to ASTM D648-2007, with a temperature range from room temperature to 300°C and a three-point bending mode. The tensile strength and modulus were tested and analyzed using the national standard GB1040-92. The dielectric constant was tested using an AET dielectric constant analyzer, which directly measures the dielectric constant at 18 GHz. The shrinkage was measured by measuring the dimensions of the parts after printing and UV pre-curing and after high-temperature heat curing, and then comparing the two dimensional values.

[0065] Figure 1 This is a display piece printed with high-temperature resistant insulating ink using inkjet 3D printing in Example 1. Figure 1 The middle left picture shows the sample after inkjet 3D printing and UV pre-curing, and the right picture shows the sample after high-temperature thermal curing.

[0066] Figure 2 The conductive circuit device printed by inkjet 3D printing of high temperature resistant insulating ink in Example 2, Figure 2The middle left and right pictures are electronic device pictures with nanosilver conductive circuits printed on the device surfaces of different shapes obtained after insulating ink printing and heat curing treatment.

[0067] Figure 3 This is a printed display piece of the high temperature resistant insulating ink of Example 3 after inkjet 3D printing (without heat curing treatment), Figure 3 It can be seen that the inkjet 3D printed high temperature resistant insulating ink has high printing accuracy.

[0068] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A high temperature resistant insulating ink for solvent-free inkjet 3D printing, characterized in that: The invention is composed of the following components in parts by mass: 40 to 60 parts of cyanate precursor, 20 to 30 parts of diluent monomer, 5 to 20 parts of crosslinking agent, 5 to 8 parts of photoinitiator, and 1 to 5 parts of auxiliary agent; The cyanate precursor is dicyclopentadiene cyanate and bis(4-isocyanatephenyl)methane; The diluent monomers are ethyl isocyanate methacrylate and acryloylmorpholine; The cross-linking agent is di-pentaerythritol hexaacrylate; The photoinitiator is one or more of trimethylbenzoyldiphenylphosphine oxide, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-isopropylthioxanthone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; The high-temperature resistant insulating ink for solvent-free inkjet 3D printing has a viscosity of 5 to 40 cps at 25° C. and a surface tension of 10 to 50 mN / m.

2. The high temperature resistant insulating ink for solvent-free inkjet 3D printing according to claim 1, characterized in that: The auxiliary agent is one or more of a leveling agent, a defoaming agent and a wetting agent.

3. The method for preparing the high temperature resistant insulating ink for solvent-free inkjet 3D printing according to claim 1 or 2, characterized in that: The following steps are involved: The cyanate precursor, the diluent monomer, the cross-linking agent, the photoinitiator and the auxiliary agent are mixed to obtain the high-temperature resistant insulating ink for solvent-free inkjet 3D printing.

4. Use of the high-temperature resistant insulating ink for solvent-free inkjet 3D printing according to claim 1 or 2 in the integrated preparation of electronic devices.

5. A method for preparing an inkjet 3D printing device, characterized in that: The following steps are involved: Performing inkjet 3D printing and UV pre-curing on the solvent-free inkjet 3D printing high-temperature resistant insulating ink according to claim 1 or 2 to obtain a preformed device; The preformed device is thermally cured to obtain the inkjet 3D printed device.

6. The preparation method according to claim 5, characterized in that The UV pre-curing has a curing wavelength of 355 to 405 nm and a curing power of 500 to 5000 mW.

7. The preparation method according to claim 5, characterized in that The thermal curing includes a first thermal curing, a second thermal curing, a third thermal curing, a fourth thermal curing and a fifth thermal curing performed in sequence. The temperature of the first thermal curing is 80-100°C and the insulation time is 1-2 hours. The temperature of the second thermal curing is 120-140°C and the insulation time is 1-2 hours. The temperature of the third thermal curing is 150-160°C and the insulation time is 1-2 hours. The temperature of the fourth thermal curing is 180-200°C and the insulation time is 1-2 hours. The temperature of the fifth thermal curing is 220-240°C and the insulation time is 2 hours.

8. The preparation method according to claim 7, characterized in that The thermal curing is performed in a vacuum, nitrogen or argon atmosphere.

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