RFID composite conductive paste and its manufacturing method, RFID electronic tag

Abstract

The present invention belongs to the technical field of electronic materials and electronic devices, and provides an RFID composite conductive paste and its manufacturing method, and an RFID electronic tag, and the RFID composite conductive paste includes, by weight, 10-25 parts by weight of oil-based special crosslinked resin, 30-50 parts by weight of metal conductive agent, 5-10 parts by weight of two-dimensional carbon-based material, 20-50 parts by weight of organic solvent, 10-20 parts by weight of quick-drying agent, and 2-5 parts by weight of leveling agent. The RFID composite conductive paste provided by the present invention has a high solid content of conductive components, has ideal dispersion and uniformity, and has well-balanced and stable performance.

Description

[Technical field]

[0001] The present invention relates to the technical fields of electronic materials and electronic equipment, in particular to a new material for manufacturing electronic components, a new process and the manufactured electronic components, in particular to provide an RFID composite conductive paste and its manufacturing method, and an RFID electronic tag. [Background technology]

[0002] RFID technology, also known as radio frequency identification technology, was originally derived from radar technology and is a type of automatic identification technology. Its working principle is to use radio frequencies to perform non-contact two-way communication and to use electronic tags and radio frequency cards to read and write. Its strength is that it can be recognized quickly and accurately under contactless conditions, and as the technical foundation of the Internet of Things, related industries and technologies are developing rapidly.

[0003] The conventional RFID tag is made of thin metal film (such as aluminum or copper foil) and is produced by a metal etching process, which includes the steps of preparing the substrate, applying a photosensitive material, sequentially exposing, developing, etching, peeling, rinsing, and drying. The above manufacturing method has complicated and cumbersome process steps, high process costs, low material utilization rate, and produces a large amount of wastewater containing heavy metals, which causes certain pollution to the environment.

[0004] In recent years, with the continuous progress of RFID component manufacturing technology, a method for manufacturing RFID electronic tags based on a printing process has appeared on the market, which uses a method such as gravure printing to print a liquid conductive paste on a substrate according to a preset pattern, and then dries and hardens the substrate by heating, light curing, etc. to obtain a conductive RFID electronic tag. For example, invention 201810111964.1 discloses a method for manufacturing a graphene conductive ink that can be used for RFID electronic tags, and invention 201910216604.2 discloses a graphene-based RFID antenna and a printing method thereof.

[0005] However, the conductive inks for printing RFID electronic tags disclosed in the above-mentioned prior art are all manufactured based on aqueous resins, and during use, the conductive performance is rather poor. Due to the characteristics of the metal conductive powder and graphene themselves, there are problems such as poor dispersion and uniformity of the paste system and poor performance stability. In addition, the aqueous conductive paste has a slow drying speed, which makes it difficult to match with the process of a gravure printing machine, resulting in low production capacity. Summary of the Invention

[0006] In order to solve the above-mentioned problems of the prior art, the present invention aims to provide a carbon-based composite conductive paste with a high content of conductive components and ideal dispersion, uniformity, adhesion and stability, and a manufacturing method thereof. The RFID electronic tag printed and obtained using this conductive paste has excellent conductive performance and high consistency of product performance parameters.

[0007] The present invention provides an RFID composite conductive paste containing, by weight, 10 to 25 parts by weight of an oil-based special crosslinked resin, 30 to 50 parts by weight of a metal conductive agent, 5 to 10 parts by weight of a two-dimensional carbon-based material, 20 to 50 parts by weight of an organic solvent, 10 to 20 parts by weight of a quick-drying agent, and 2 to 5 parts by weight of a leveling agent.

[0008] Preferably, the oil-based special crosslinking resin is a polyurethane-modified epoxy resin, and the carrier saturation solid content in the oil-based system of the polyurethane-modified epoxy resin is 55% or more.

[0009] Preferably, the oil-based special crosslinking resin has a dry film density of 1.4 g / m 3 The high cohesive strength chloroacetic acid resin is further added.

[0010] Preferably, the two-dimensional carbon-based material is a physical oil-based graphene paste containing 9 to 11 graphene layers.

[0011] Further, the physical method oil-based graphene paste includes a first step of mixing highly intercalated graphite with a divalent acid ester and an oil-based special cross-linking resin to obtain an initial graphene paste having a magnification of the highly intercalated graphite of 150 to 350 times and a purity of 99% or more; and a second step of subjecting the initial graphene paste to liquid phase peeling under high pressure to obtain a physical oil-based graphene paste having 9 to 11 graphene layers.

[0012] Preferably, the metal conductive agent is one or a mixture of silver-coated copper powder, silver-coated nickel powder, nickel-coated copper powder, and modified conductive copper powder.

[0013] Preferably, the quick-drying agent is one or a mixture of ethyl acetate, butyl acetate, acetone, and cyclohexanone.

[0014] The present invention relates to Step S1: placing an oil-based special cross-linked resin and an organic solvent in a container, heating to 50°C, dispersing at a dispersion frequency of 1800 to 2200 revolutions per minute for a dispersion time of 50 to 70 minutes to obtain a conductive paste carrier; Step S2 of adding a two-dimensional carbon-based material and a metal conductive agent to the conductive paste carrier and stirring for a stirring time of 25 to 35 minutes to obtain a carbon-based composite conductive paste; Step S3: adding a quick-drying agent and a leveling agent to the carbon-based composite conductive paste, dispersing the paste at a dispersion frequency of 800 to 1200 revolutions per minute and for a dispersion time of 25 to 35 minutes to obtain an RFID composite conductive paste; The present invention further provides a method for producing the above-mentioned RFID composite conductive paste, the method including: using a grinding machine to grind the RFID composite conductive paste (S4).

[0015] Preferably, the grinding machine is a three-roll mill, the roll pitch is 0.4 to 0.6 mm, and the grinding number is one.

[0016] The present invention further provides an RFID electronic tag, comprising an insulating substrate, an RFID radio frequency circuit and a control chip fixed on the surface of the insulating substrate, the control chip being electrically connected to the RFID radio frequency circuit, and the RFID radio frequency circuit being fabricated by the above-mentioned RFID composite conductive paste in a gravure printing manner.

[0017] The present invention has at least the following beneficial effects:

[0018] (1) The RFID composite conductive paste provided by the present invention has a high solid content of conductive components. By carrying out modification and optimization processing on the resin carrier and graphene paste, it can form a better synergistic effect compared with traditional materials, effectively increasing the solid content of the carrier, improving the ability of the conductive paste to accommodate solid conductive components, and ensuring that the RFID circuit pattern formed after drying and curing contains sufficient conductive components.

[0019] (2) The RFID composite conductive paste provided by the present invention has ideal dispersion and uniformity. The conductive paste carrier used in the present invention is an oil-based special cross-linked resin, and the oil-based graphene paste obtained by using low-magnification high-order intercalation graphite raw material is used as a caulking agent for metal conductive agent to form a composite conductive structure. The above-mentioned modified and optimized oil-based resin and oil-based graphene material ensure good dispersion and uniformity of conductive components in the RFID composite conductive paste obtained, so as to further improve the performance index of RFID circuit and the final RFID electronic tag.

[0020] (3) The RFID composite conductive paste provided by the present invention has well-balanced and stable performance. The RFID composite conductive paste provided by the present invention has a composition ratio of each component and manufacturing process parameters that are determined through a large number of experiments to ensure that the properties of fluidity, adhesion, quick-drying and adhesiveness are in a balanced state, and the properties of the conductive paste are stable. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a schematic diagram of a sample RFID electronic tag. [Diagram 2] 1 is a microstructure of conventional graphene material. [Diagram 3] 1 is a microstructure of a physical oil-based graphene paste provided by an embodiment of the present invention; [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Diagram 5] 1 is a front view of an RFID electronic tag provided by an embodiment of the present invention. [Figure 6] 1 is a side view of an RFID electronic tag provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In the following, the invention will be further explained on the basis of preferred embodiments with reference to the drawings.

[0023] In addition, the various components in the drawings are enlarged or reduced in size for ease of understanding, but such an approach is not intended to limit the scope of protection of the present invention.

[0024] Words in the singular include the plural and vice versa.

[0025] In the description of the embodiments of the present invention, if the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer" and the like is based on the drawings, or if the orientation or positional relationship is always placed when the product according to the embodiments of the present invention is used, it is merely for the ease and simplification of the description of the present invention, and does not indicate or imply that the device or element to be referred to has a specific orientation, must be configured and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, in the description of the present invention, the term "first", "second", and the like are used in this specification to distinguish different units, but these are not limited to the order of manufacture, and cannot be understood as indicating or implying relative importance, and the names may be different in the detailed description of the present invention and the claims.

[0026] The terms used in this specification are used to describe the embodiments of the present invention, but are not intended to limit the present invention. Furthermore, unless otherwise clearly defined and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, fixed connection, removable connection, integral connection, mechanical connection, direct connection, indirect connection via an intermediate medium, or internal communication between two elements. The specific meaning of the above terms in the present invention can be specifically understood by those skilled in the art.

[0027] In order to better explain the technical solution of the present invention, the process flow of manufacturing RFID electronic tags by printing means is first introduced, and the problems and reasons existing in the prior art conductive ink are analyzed.

[0028] FIG. 1 is a schematic diagram of a specific RFID electronic tag sample. As shown in FIG. 1, a certain pattern of RFID radio frequency circuit is attached to an insulating substrate. The process flow of the above-mentioned RFID electronic tag using printing means is generally as follows: The method includes the steps of injecting or applying a liquid conductive ink into a groove having a mirror pattern of a corresponding radio frequency circuit, scraping off the conductive ink in the groove with a device such as a doctor blade and removing the conductive ink outside the groove, transferring the conductive ink onto an insulating substrate by a method such as a roll press to form a forward circuit pattern, and performing operations such as drying and curing on the conductive ink to finally obtain an RFID electronic tag.

[0029] In order to obtain RFID tags with excellent conductive performance and high consistency in product parameters, the above-mentioned printing manufacturing process of RFID tags places strict requirements on the performance of the conductive paste used. An ideal conductive paste should have the following properties:

[0030] (1) High solid content of conductive components Since the RFID radio frequency circuit obtained by printing using the conductive paste needs to have good conductivity and reflection properties against ultra-high frequency radio waves, the paste must have an ideal ability to accommodate solid conductive components to ensure that the formed circuit pattern contains sufficient conductive components after drying and curing.

[0031] (2) The conductive components have an ideal degree of dispersion and uniformity. When the paste can fully accommodate the conductive components, the distribution of the above-mentioned conductive components in the paste will affect the conductive performance of the final RFID circuit and the consistency of product performance parameters, among which, the conductive components need to be well dispersed in the paste to ensure the conductive components at each site, and also need to have good uniformity to avoid problems such as unstable conductivity and signal reflection performance at different positions and reduced yield caused by uneven distribution or aggregation of the conductive components.

[0032] (3) A better balance between fluidity and adhesion, and between quick-drying and adhesive properties. The conductive paste described above must have good fluidity to ensure the integrity of the circuit pattern during the injection process into the printing gravure, good adhesion to ensure that the circuit is firmly attached to the insulating substrate, and quick-drying properties to meet the needs of large-scale mass production. It must also ensure adhesion between the conductive components in the paste to prevent problems such as breakage of the pattern during the quick-drying process. Therefore, it is necessary to modify and optimize each component and adjust the compounding ratio and manufacturing process to obtain the optimal overall effect.

[0033] (4) The properties of the conductive paste material are stable. Conductive paste contains solid and liquid components with various different properties, so it is necessary to modify and optimize each component in the same way and increase the affinity between each component to avoid phenomena such as layering and precipitation in the paste, which may affect the stability of the product.

[0034] However, various conductive inks or conductive pastes disclosed in the prior art have various defects to different degrees, mainly as follows:

[0035] (1) The conductive pastes used in conventional technologies are often produced by simply physically mixing an aqueous resin with a common graphene material and a metal conductive agent (metal powder), and their conductive performance is somewhat inferior.

[0036] (2) Due to the characteristics of the metal conductive powder and graphene themselves, their specific surface area and the surface tension of the aqueous system are both large, and the aqueous resin has difficulty in sufficiently wetting their surfaces. As a result, the entire paste system is difficult to disperse evenly and is prone to agglomeration, which affects the conductivity and parameter consistency of the printed RFID circuit. It is also prone to stratification and precipitation when left for a long time, resulting in a decrease in the stability of the paste.

[0037] (3) The drying speed of water-based conductive paste is slow, which makes it difficult to match with the gravure printing process, resulting in a slow production speed and making it difficult to realize large-scale mass production.

[0038] In order to solve the various shortcomings of the conductive pastes of the prior art described above, one embodiment of the present invention provides an RFID composite conductive paste containing, by weight, 10-25 parts by weight of an oil-based special crosslinked resin, 30-50 parts by weight of a metal conductive agent, 5-10 parts by weight of a two-dimensional carbon-based material, 20-50 parts by weight of an organic solvent, 10-20 parts by weight of a quick-drying agent, and 2-5 parts by weight of a leveling agent.

[0039] Specifically, the above-mentioned oil-based special cross-linking resin is used to support a conductive component consisting of a metal conductive agent and a two-dimensional carbon-based material as a base to form an oil-based conductive paste system, the two-dimensional carbon-based material is used as a caulking agent for the metal conductive agent to form a composite conductive structure, the organic solvent is used to dilute and adjust the concentration and viscosity of the conductive paste, the leveling agent is used to increase the fluidity of the conductive paste, and the quick-drying agent is used to increase the drying speed of the conductive paste.

[0040] In some preferred embodiments of the present invention, the oil-based special crosslinking resin is a polyurethane-modified epoxy resin, and the polyurethane-modified epoxy resin has higher carrier saturation solids and dry film density than conventional epoxy resins, and its carrier saturation solids in the oil-based system is more than 55%, and its dry film density is 1.2g / m 3 That's all.

[0041] Table 1 below shows a comparison of the performance at carrier saturation solids of polyurethane modified epoxy resins and conventional epoxy resins.

[0042] Table 1 Comparison of carrier saturated solids between polyurethane modified epoxy resin and conventional epoxy resin [Table 1]

[0043] In some embodiments of the present invention, the oil-based special crosslinked resin is obtained by subjecting epoxy resin to polyurethane modification treatment. The modification treatment of epoxy resin is a technique known to those skilled in the art, and the operation, mixing ratio of reactants, reaction conditions, etc. in the implementation process can be set according to the performance to be achieved.

[0044] In some embodiments of the present invention, the oil-based special crosslinked resin may be obtained by directly purchasing the product. For example, the modified epoxy resin and / or modified polyurethane resin produced by the American Huntsman Company may be used as the oil-based special crosslinked resin. The above-mentioned thermoplastic resin produced by this company has excellent dispersibility, and can greatly reduce the amount of resin used without affecting the dispersibility of the conductive paste. Thus, the proportion of the conductive agent in the entire formulation can be greatly increased, thereby improving the conductivity of the entire paste and greatly improving the performance of the printed electronic label.

[0045] In some preferred embodiments of the present invention, the oil-based special crosslinked resin has a dry film density of 1.4 g / m 3 The high cohesive strength chloroacetic acid resin is further added.

[0046] Table 2 below shows a comparison of the dry film density performance of polyurethane modified epoxy resins, high cohesive strength chloroacetic acid resins, and conventional epoxy resins.

[0047] Table 2. Comparison of dry film density between polyurethane modified epoxy resin, high cohesive strength chloroacetic acid resin and conventional epoxy resin [Table 2]

[0048] Conventional epoxy resins have high viscosity, making them difficult to prepare as a conductive paste carrier with high solid content, and have problems such as poor fluidity, thick film layer after curing, low density, high brittleness, etc. Because the depth of the grooves used in gravure printing is shallow (micron level) and the pattern width is millimeter level, when conductive pastes made based on conventional epoxy resins are applied to gravure-printed RFID circuits, problems such as poor circuit conductivity and ultra-high frequency radio wave reflection properties, insufficient circuit patterns, and easy breakage are likely to occur.

[0049] The present invention uses polyurethane-modified epoxy resin as oil-based special crosslinking resin, preferably adding high cohesive chloroacetic acid resin therein. The above-mentioned oil-based special crosslinking resin is used as a conductive paste carrier, and the polyurethane-modified epoxy resin contained therein has a higher saturated solid content than conventional epoxy resins, and can carry more conductive components per unit volume, thus effectively improving the conductive properties and reflective properties of the printed circuit. The addition of high cohesive chloroacetic acid resin can reduce the viscosity of the paste, and can also improve the cohesive force of the paste to achieve good dispersion of powdered conductive components, thereby effectively increasing the density after film formation, reducing the layer thickness of the dry film, and improving the flexibility of the dry film and its adhesion to the substrate.

[0050] In some embodiments of the present invention, phenoxy resin and / or polyester resin are added to the oil-based special cross-linking resin, and the phenoxy resin and polyester resin have the advantages of contributing to the dispersion of the conductive paste, making the appearance of the conductive paste more delicate, improving the printing performance of the conductive paste itself, making the surface of the electronic label by gravure printing smooth and flat, and greatly improving the consistency of performance.

[0051] In some preferred embodiments of the present invention, the metal conductive agent is one or more of the following mixtures: silver-coated copper powder, silver-coated nickel powder, nickel-coated copper powder, and modified conductive copper powder.

[0052] In some preferred embodiments of the present invention, the two-dimensional carbon-based material is a physical oil-based graphene paste containing 9 to 11 graphene layers, and the physical oil-based graphene paste is: A first step of mixing highly intercalated graphite with a divalent acid ester (DBE solvent) and an oil-based special cross-linking resin to obtain an initial graphene paste having a magnification of the highly intercalated graphite of 150 to 350 times and a purity of 99% or more; and a second step of subjecting the initial graphene paste to liquid phase exfoliation under high pressure to obtain a physical oil-based graphene paste having 9 or more and 11 or less graphene layers.

[0053] The graphene material mixed into the conductive paste for RFID electronic tag printing can be used as a filler for the metal powder of the metal conductive agent, and can efficiently bond the metal powder dispersed in the resin carrier, thereby further improving the conductivity and reflective properties of the printed circuit through a synergistic effect.

[0054] However, the graphene used in the prior art is all conventional graphene material, and Figure 2 shows the microstructure of the conventional graphene material, which shows obvious thickness unevenness and aggregation phenomena, and at the same time, the range of the number of layers of the conventional graphene material is large and irregular, among which the part with a low number of layers can improve the conductive performance, but the particle size is small and it is difficult to exert the filling effect, and the part with a high number of layers has an obvious decrease in conductivity. After the conductive paste is added to the conventional graphene material that has not been subjected to the above-mentioned optimization process, due to the disorder of its microstructure, it cannot generate a good synergistic effect with the conductive metal powder, and may also cause a bad effect.

[0055] In the present invention, the graphene material added to the conductive paste is an optimized physical oil-based graphene paste, in which the initial graphene paste is obtained by mixing a high-purity high-order intercalation graphite raw material and a diacid ester at a low magnification, and has a low magnification, high purity, easy dispersion, and good intercalation effect. The initial graphene paste can be liquid-phase exfoliated under high pressure to produce a physical oil-based graphene paste with a graphene layer number of about 10 layers.

[0056] Figure 3 shows the microstructure of the physical oil-based graphene paste provided by the embodiment of the present invention, and Figure 4 is a partially enlarged structure of Figure 3. As can be seen from Figures 3 and 4, the physical oil-based graphene paste used in the embodiment of the present invention has a more uniform thickness compared to conventional graphene materials, and at the same time, the microstructure is optimized and the number of layers is relatively consistent, which can simultaneously have excellent conductivity and filling effect, and form a good synergistic effect with the metal conductive agent, further improving the performance index of the RFID circuit.

[0057] The following Table 3 shows a comparison of the performance parameters between the physical oil-based graphene paste provided in one specific embodiment of the present invention and the conventional graphene material (the proportion of graphene components therein, the types and proportions of other components, and the manufacturing process are all the same). From Fig. 2, Fig. 3 and Table 3, it can be seen that the oil-based graphene paste provided in the embodiment of the present invention can show improvements in microstructure, filling performance, and conductive performance compared to the conventional graphene materials used in the prior art.

[0058] Table 3. Comparison of performance between physical oil-based graphene paste and conventional graphene materials [Table 3]

[0059] In some preferred embodiments of the present invention, the quick-drying agent is one or more of the following mixtures: ethyl acetate, butyl acetate, acetone, and cyclohexanone. The addition of the quick-drying agent to the conductive paste can speed up the drying and curing of the printed RFID circuit, thereby improving the production speed of RFID electronic tags.

[0060] In some preferred embodiments of the present invention, the quick-drying agent may be isoflurane, or a mixture of isoflurane and one or more of the above-mentioned ethyl acetate, butyl acetate, acetone, and cyclohexanone. Isofluron not only has a quick-drying effect, but also acts to super-disperse and reduce the viscosity of graphene and metal conductive agent, which is favorable for the fluidity of the entire paste system and improves the printing performance.

[0061] In a preferred embodiment of the present invention, a leveling agent is added and the compounding ratio of the leveling agent is adjusted, so that the conductive paste can be sufficiently filled into the grooves and leveled, and the RFID circuit pattern transferred to the substrate can be prevented from flowing around and affecting the accuracy of the pattern. The printed RFID electronic tab has a uniform thickness, stable conductivity, and high consistency.

[0062] In some preferred embodiments of the present invention, the organic solvent is a diacid ester (DBE solvent).

[0063] If the resin content of the conductive paste is too high, the conductivity will deteriorate; if the metal conductive agent content is too high, the paste viscosity will be too high, making production difficult and also disadvantageous in terms of cost control; in addition, the graphene and metal conductive agent as a caulking agent are strictly proportional to each other; if the graphene content is too low, it will be difficult to effectively fill the gaps between the metal conductive agents, resulting in reduced conductive performance; however, if the graphene content is too high, the connection bridge between the metal conductive agents will be hindered, resulting in reduced conductive performance. This has been proven through a large amount of experiments.

[0064] Due to the above-mentioned various performance needs, the performance of the conductive paste cannot be obtained by simply stacking the normal effects of the various components contained therein, especially when the performance and effects of different components affect each other, it is necessary to eliminate the negative effects and amplify the beneficial effects through adjustment of the compounding ratio and modification optimization. The RFID composite conductive paste provided by the present invention has a strictly proportional compounding ratio of each component, and the resin carrier and graphene paste are modified and optimized to form a better synergistic effect than conventional materials.

[0065] Another aspect of the present invention provides a method for producing the RFID composite conductive paste, for producing the above-mentioned RFID composite conductive paste, comprising: Step S1: placing an oil-based special cross-linked resin and an organic solvent in a container, heating to 50°C, dispersing at a dispersion frequency of 1800 to 2200 revolutions per minute for a dispersion time of 50 to 70 minutes to obtain a conductive paste carrier; Step S2 of adding a two-dimensional carbon-based material and a metal conductive agent to the conductive paste carrier and stirring for a stirring time of 25 to 35 minutes to obtain a carbon-based composite conductive paste; Step S3: adding a quick-drying agent and a leveling agent to the carbon-based composite conductive paste, dispersing the paste at a dispersion frequency of 800 to 1200 revolutions per minute and for a dispersion time of 25 to 35 minutes to obtain an RFID composite conductive paste; and step S4 of grinding the RFID composite conductive paste using a grinding machine.

[0066] The RFID composite conductive paste is ground using a three-roll mill to further promote the uniform distribution of conductive components and reduce the occurrence of phenomena such as stratification and precipitation during the printing process, thereby ensuring the stability of the conductive performance of the paste and the consistency of the product.

[0067] However, when grinding with a three-roll mill, the more the number of grinding times, the better, and the higher the grinding fineness, the better. The reasons are as follows: Inappropriate grinding times and roll pitch may have a negative effect on the performance of the conductive paste, among which, the selection of roll pitch needs to be determined by the mesh number of the metal conductive agent. In some specific embodiments of the present invention, the mesh number of the metal conductive agent is 400-600 mesh, preferably 500 mesh. If the roll pitch is set too large, the metal conductive agent cannot be effectively ground and dispersed, and if the pitch is set too small, the conductive structure of the metal powder and graphene will be destroyed. In addition, the conductive paste that is not ground will exhibit a stratification phenomenon, making the conductivity of the product unstable. Conversely, grinding multiple times will cause the destruction of the conductive structure. Due to the influence of the properties of graphene itself, grinding multiple times will also exhibit reverse coarsening and aggregation phenomena, which will affect the conductivity.

[0068] Table 4 below shows the comparison of the impact of different grinding times on the performance of conductive paste when other manufacturing processes and parameters are the same. As can be seen from the performance comparison in Table 4, the conductive paste that was not ground by three rolls and the conductive paste that was ground multiple times have inferior performance compared with the conductive paste that was ground once, and the reasons are as follows: the conductive paste that was not ground by three rolls showed obvious stratification under film printing, the conductive component aggregation was observed in the paste, the dry film surface was uneven, and the conductivity and consistency were deteriorated, and the conductive data after multiple roll-to-roll grinding was obviously worse, which was mainly due to the destruction of the silver and nickel plating layers in the silver-coated copper powder and nickel-coated copper powder, which led to a decrease in conductive performance, and at the same time, the antioxidant performance was deteriorated, and the performance degradation phenomenon was obvious after being left for a long time.

[0069] Table 4 Comparison of the effect of different grinding times on the performance of conductive paste [Table 4]

[0070] In a preferred embodiment of the present invention, the grinding machine is a three-roll mill, the roll pitch is 0.4-0.6 mm, and the number of grinding passes is one. The preferred process parameters in the above-mentioned grinding process are determined by analyzing a large amount of experimental data. The roll pitch is set to 0.4-0.6 mm to more uniformly distribute the conductive components in an aggregated state remaining in the conductive paste after rotation dispersion and stirring, and to remove the stratification. Furthermore, the number of grinding passes is limited to avoid damage to the microstructure of the metal conductive agent, and ensure the performance promotion effect of the conductive paste.

[0071] Example 1 The following steps are used to prepare the RFID composite conductive paste.

[0072] Step 1: Add 40 parts by weight of DBE solvent and 10 parts by weight of oil-based special cross-linked resin obtained by mixing polyurethane modified epoxy resin and high cohesive strength chloroacetic acid resin into a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0073] Step 2: Add 31 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 10%) and 5 parts by weight of graphene conductive paste to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0074] Step 3: Add 10 parts by weight of butyl acetate and 2 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0075] Step 4: The above-mentioned RFID composite conductive paste is subjected to one-time roll grinding using a three-roll mill with a roll pitch of 0.6 mm.

[0076] Example 2 The following steps are used to prepare the RFID composite conductive paste.

[0077] Step 1: Add 31 parts by weight of DBE solvent and 10 parts by weight of oil-based special cross-linked resin obtained by mixing polyurethane modified epoxy resin and high cohesive strength chloroacetic acid resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0078] Step 2: Add 38 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 5%) and 6 parts by weight of graphene conductive paste to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0079] Step 3: Add 12 parts by weight of butyl acetate and 3 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0080] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.5 mm.

[0081] Example 3 The following steps are used to prepare the RFID composite conductive paste.

[0082] Step 1: Add 20 parts by weight of DBE solvent and 11 parts by weight of polyurethane modified epoxy resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0083] Step 2: Add 38 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 3%) and 8 parts by weight of graphene conductive paste to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0084] Step 3: Add 14 parts by weight of butyl acetate and 4 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0085] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.4 mm.

[0086] Example 4 The following steps are used to prepare the RFID composite conductive paste.

[0087] Step 1: Add 31 parts by weight of DBE solvent and 10 parts by weight of polyurethane modified epoxy resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0088] Step 2: Add 41 parts by weight of sheet-shaped nano-nickel-coated copper powder (nickel content 5%) and 3 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier by weight, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0089] Step 3: Add 12 parts by weight of butyl acetate and 3 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0090] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.5 mm.

[0091] Example 5 The following steps are used to prepare the RFID composite conductive paste.

[0092] Step 1: Add 24 parts by weight of DBE solvent and 11 parts by weight of polyurethane modified epoxy resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0093] Step 2: Add 43 parts by weight of modified sheet-shaped nano copper powder and 4 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier by weight, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0094] Step 3: Add 14 parts by weight of ethyl acetate and 4 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0095] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding twice using a three-roll mill with a roll pitch of 0.4 mm.

[0096] Example 6 The following steps are used to prepare the RFID composite conductive paste.

[0097] Step 1: Add 24 parts by weight of DBE solvent and 11 parts by weight of oil-based special cross-linked resin obtained by mixing polyurethane modified epoxy resin and high cohesive strength chloroacetic acid resin into a mixing tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0098] Step 2: Add 43 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 3%) and 4 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0099] Step 3: Add 14 parts by weight of butyl acetate and 4 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0100] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.4 mm.

[0101] Example 7 The following steps are used to prepare the RFID composite conductive paste.

[0102] Step 1: Add 20 parts by weight of DBE solvent and 10 parts by weight of modified polyurethane resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0103] Step 2: Add 53 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 10%) and 5 parts by weight of graphene conductive paste to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0104] Step 3: Add 5 parts by weight of butyl acetate, 5 parts by weight of isoflurane, and 2 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0105] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.4 mm.

[0106] Example 8 The following steps are used to prepare the RFID composite conductive paste.

[0107] Step 1: Add 20 parts by weight of DBE solvent and 10 parts by weight of saturated polyester resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 revolutions per minute for 1 hour to produce a conductive paste carrier.

[0108] Step 2: Add 53 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 10%) and 5 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier, and continue to stir for 30 minutes to obtain a carbon-based composite conductive paste.

[0109] Step 3: Add 5 parts by weight of butyl acetate, 5 parts by weight of isoflurane, and 2 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0110] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.5 mm.

[0111] Example 9 The following steps are used to prepare the RFID composite conductive paste.

[0112] Step 1: Add 20 parts by weight of DBE solvent, 2 parts by weight of phenoxy resin, and 8 parts by weight of modified polyurethane resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0113] Step 2: Add 53 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 10%), 2 parts by weight of graphene conductive paste, and 3 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier by weight, and keep stirring for 30 minutes to obtain a carbon-based composite conductive paste.

[0114] Step 3: Add 6 parts by weight of butyl acetate, 4 parts by weight of isoflurane, and 2 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0115] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.4 mm.

[0116] Example 10 The following steps are used to prepare the RFID composite conductive paste.

[0117] Step 1: Add 20 parts by weight of DBE solvent, 4 parts by weight of saturated polyester resin, and 6 parts by weight of modified polyurethane resin to a stirring tank, heat to 50°C, and disperse and stir using a dispersion disk at a frequency of 2000 rpm for 1 hour to produce a conductive paste carrier.

[0118] Step 2: Add 53 parts by weight of sheet-shaped nano silver-coated copper powder (silver content 10%), 3 parts by weight of graphene conductive paste, and 2 parts by weight of highly-filled conductive carbon black to the above-mentioned conductive paste carrier by weight, and keep stirring for 30 minutes to obtain a carbon-based composite conductive paste.

[0119] Step 3: Add 15 parts by weight of isoflurone and 2 parts by weight of leveling agent to the above carbon-based composite conductive paste by weight, and keep stirring for 30 minutes to obtain RFID composite conductive paste.

[0120] Step 4: The above-mentioned RFID composite conductive paste is subjected to roll-to-roll grinding once using a three-roll mill with a roll pitch of 0.5 mm.

[0121] Table 5 below shows a comparison of the performance of the RFID printing conductive pastes produced according to preferred Example 2, Example 3, Example 7 and Example 8 with the conductive pastes produced according to the prior art.

[0122] Table 5. Comparison of performance between the preferred embodiment of the present invention and conductive pastes manufactured using the prior art. [Table 5]

[0123] Another embodiment of the present invention further provides an RFID electronic tag, and FIGS. 5 and 6 respectively show a top view and a side view of an RFID electronic tag according to an embodiment of the present application. As shown in FIGS. 5 and 6, the RFID electronic tag provided by the present invention comprises an insulating substrate 10, an RFID radio frequency circuit 11 and a control chip 12 fixed on the surface of the insulating substrate, the control chip 12 is electrically connected to the RFID radio frequency circuit 11, and the RFID radio frequency circuit 11 is fabricated by using the above-mentioned RFID composite conductive paste by gravure printing.

[0124] Specifically, the above-mentioned RFID composite conductive paste is first poured into the groove of a gravure roller and scraped (in which the groove pattern is a mirror image pattern of the RFID radio circuit 11 to be manufactured), then the RFID composite conductive paste in the groove is transferred to the insulating substrate 10 by rolling between the gravure roller and the plant roller to form the RFID radio circuit 11, and finally the control chip 12 is fixed to the insulating substrate 10 by a method such as adhesion, and it may be electrically connected to the RFID radio frequency circuit by a method such as welding (the connector 121 in FIG. 5 and FIG. 6 is the connection part between the control chip 12 and the RFID radio frequency circuit 11). The method of manufacturing an RFID electronic tag by the above-mentioned gravure printing method is known to those skilled in the art, so it will not be described again here.

[0125] FIG. 5 shows a specific pattern of the RFID radio circuit 11. Those skilled in the art can select or modify the specific pattern of the RFID radio circuit and the specification model of the control chip according to actual needs in the process of actually manufacturing the RFID electronic tag, and it is easy to know that the above selection and modification do not deviate from the protection scope of the claims of the present invention.

[0126] Although the specific embodiments of the present invention have been described in detail above, those skilled in the art may further make some improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The composition includes, by weight, 10 to 25 parts by weight of an oil-based special cross-linked resin, 30 to 50 parts by weight of a metal conductive agent, 5 to 10 parts by weight of a two-dimensional carbon-based material, 20 to 50 parts by weight of an organic solvent, 10 to 20 parts by weight of a quick-drying agent, and 2 to 5 parts by weight of a leveling agent. RFID composite conductive paste.

2. The oil-based special crosslinking resin is a polyurethane-modified epoxy resin, and the carrier saturation solid content in the oil-based system of the polyurethane-modified epoxy resin is 55% or more. The RFID composite conductive paste according to claim 1.

3. The oil-based special cross-linked resin has a dry film density of 1.4 g / m ３ A high cohesive strength chloroacetic acid resin having the above-mentioned properties is further added. The RFID composite conductive paste according to claim 2.

4. The two-dimensional carbon-based material is a physical oil-based graphene paste containing 9 to 11 graphene layers. The RFID composite conductive paste according to claim 1.

5. The physical method oil-based graphene paste is A first step of mixing highly intercalated graphite with a divalent acid ester and an oil-based special crosslinking resin to obtain an initial graphene paste having a magnification of the highly intercalated graphite of 150 to 350 times and a purity of 99% or more; A second step of subjecting the initial graphene paste to liquid phase peeling under high pressure to obtain a physical oil-based graphene paste having 9 to 11 graphene layers. The RFID composite conductive paste according to claim 4.

6. The metal conductive agent is one or more of silver-coated copper powder, silver-coated nickel powder, nickel-coated copper powder, and modified conductive copper powder, and is a mixture of these. The RFID composite conductive paste according to claim 1.

7. The quick-drying agent is one or a mixture of ethyl acetate, butyl acetate, acetone, and cyclohexanone. The RFID composite conductive paste according to claim 1.

8. A method for producing the RFID composite conductive paste according to any one of claims 1 to 7, comprising the steps of: Step S1: placing an oil-based special cross-linked resin and an organic solvent in a container, heating to 50°C, dispersing at a dispersion frequency of 1800 to 2200 revolutions per minute for a dispersion time of 50 to 70 minutes to obtain a conductive paste carrier; Step S2: adding a two-dimensional carbon-based material and a metal conductive agent to the conductive paste carrier, and stirring for a stirring time of 25 to 35 minutes to obtain a carbon-based composite conductive paste; Step S3: adding a quick-drying agent and a leveling agent to the carbon-based composite conductive paste, dispersing the paste at a dispersion frequency of 800 to 1200 revolutions per minute and for a dispersion time of 25 to 35 minutes to obtain an RFID composite conductive paste; S4. Grinding the RFID composite conductive paste with a grinding machine. A method for producing RFID composite conductive paste.

9. The grinding machine is a three-roll mill, the roll pitch is 0.4 to 0.6 mm, and the number of grinding passes is one. The method for producing the RFID composite conductive paste according to claim 8.

10. An RFID electronic tag comprising an insulating substrate, an RFID radio frequency circuit and a control chip fixed to a surface of the insulating substrate, the control chip being electrically connected to the RFID radio frequency circuit, The RFID radio frequency circuit is produced by using the RFID composite conductive paste as claimed in claim 1 through gravure printing. RFID electronic tag.

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