Conductive ink and preparation method thereof

Abstract

The present invention discloses a conductive ink and a preparation method thereof. The ink comprises a positive charge center formed by liquid metal single substance or alloy particles, and a negative charge shell formed by conjugated polymer and charge compensator on the surface of the positive charge center; and also comprises a functional additive. The preparation method comprises: weighing liquid metal, conjugated polymer, and charge compensator in proportion and mixing them, and then dispersing the liquid metal into micro-nano droplets; adding functional additives in proportion, stirring and mixing, and cooling to room temperature to obtain the conductive ink. The present invention always maintains the connection of the conductive path in a complex environment, obtains stable high conductivity, and the conductivity is 1×10 4 ~1×10 6 S / m, and the rate of change of conductivity is ±5%; it has the advantages of simple preparation and low cost, and has broad application prospects in modern electronic industries such as printed circuit boards, smart textiles, and flexible electronic devices.

Description

Technical Field

[0001] The invention relates to a coating composite material and a preparation method thereof, and in particular to a conductive ink and a preparation method thereof. Background Art

[0002] Conductive ink usually refers to a coating material with conductive function. With the development of society, conductive ink has been widely used in modern electronic industries such as printed circuit boards, smart textiles, and flexible electronic devices. At present, polymer-based conductive ink has been widely used.

[0003] Intrinsically conductive polymers (such as polypyrrole and polyacetylene) are complex to prepare, costly, and have poor processability, making them difficult to use as inks on a large scale. Therefore, physical methods are usually used to compound conductive fillers and polymer substrates.

[0004] Conductive fillers in polymer conductive inks are usually mainly carbon materials (carbon black, graphene, carbon nanotubes, etc.) and metal materials (silver nanorods, silver nanowires, etc.). However, carbon materials have low conductivity; silver metal is expensive. Modern process production requires simple preparation methods, low cost, high material stability, and low environmental harm. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a stable and highly conductive conductive ink;

[0006] The second object of the present invention is to provide a method for preparing the above conductive ink.

[0007] Technical solution: The conductive ink described in the present invention includes a positive charge center formed by liquid metal element or alloy particles, and a negative charge shell formed by conjugated polymers and charge compensators on the surface of the positive charge center; it also includes functional additives.

[0008] The composition comprises the following components by weight: 10 to 70 parts of liquid metal, 1 to 30 parts of conjugated polymer, 10 to 80 parts of charge compensator, and 0.1 to 2 parts of functional additive.

[0009] Wherein, the metal in the liquid metal element or alloy is a liquid metal in the range of 10°C to 300°C.

[0010] Wherein, the liquid metal single substance or alloy particles are micro-nano-scale particles with a particle size ranging from 100nm to 20μm.

[0011] Wherein, the conjugated polymer is one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, polyacetylene, polythiophene, polypyrrole, poly(3-alkylthiophene), poly(p-phenylene vinylene), poly(p-phenylene sulfide), poly(3-hexylthiophene), poly(3-octylthiophene), poly(3-cyclohexylthiophene), and poly(3-methyl-4-cyclohexylthiophene).

[0012] The liquid metal includes gallium metal and gallium-based metal, and the gallium-based metal is composed of gallium metal and one or more of indium, tin, bismuth, zinc, magnesium, aluminum, copper, gold, silver, titanium, vanadium, manganese, magnesium, calcium, platinum, cadmium, cobalt, nickel, and barium metals.

[0013] Wherein, the charge compensator is one of sodium alginate, potassium alginate, calcium alginate, ammonium alginate, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, sodium hyaluronate, potassium hyaluronate, gellan gum, nitrocellulose, sodium salicylate, thiosalicylic acid, and magnesium salicylate.

[0014] Wherein, the functional additive is at least one of an antioxidant, a heat stabilizer, a light stabilizer, a lubricant, a flame retardant, a thickener, a plasticizer, a thixotropic agent, and a filler.

[0015] Among them, the antioxidant is one of antioxidant-1010, antioxidant-1076, antioxidant-364, antioxidant-2246, octylated diphenylamine, 4,4-bis(α,α-dimethylbenzyl)diphenylamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N-phenyl-N'-(p-toluenesulfonyl)-p-phenylenediamine, trinonylphenyl phosphite, distearate dithiopropionate, and dilauryl dithiopropionate.

[0016] Wherein, the heat stabilizer is one of cyclohexane acid, lauric acid, palmitic acid, oleic acid, benzoic acid, salicylic acid, tribasic lead sulfate, dibasic lead phosphite, dibasic lead stearate, phosphite, dibutyltin dilaurate, dibutyltin maleate, and dibutyltin maleate.

[0017] Wherein, the light stabilizer is one of titanium dioxide, zinc oxide, carbon black, 3,5-di-tert-butyl-4-hydroxybenzyl monoethyl phosphate nickel, 2,2-thiobis(4-tert-octylphenol)nickel-n-butylamine, dibutyldithiocarbamate nickel, 4-benzoyl-2,2,6,6-tetramethylpiperidine, sebacic acid (2,2,6,6-tetramethylpiperidinyl) ester, tris(1,2,2,6,6-pentamethylpiperidinyl) phosphite, benzophenone (UV-9, UV-24, UV-342, UV-531, UV-356), and light stabilizer 944.

[0018] Wherein, the lubricant is one of vinyl bisstearamide, oleamide, erucamide, n-butyl stearate, trihydroxystearate, microcrystalline paraffin, liquid paraffin, chlorinated paraffin, polyethylene wax, oxidized polyethylene wax, methyl silicone oil, benzyl silicone oil, ethyl silicone oil, polyethylene, polypropylene, high boiling point paraffin, polystyrene, ABS resin, polyamide, PBT / PET resin, phenolic resin, and amino resin.

[0019] Wherein, the flame retardant is one of aluminum hydroxide, magnesium hydroxide, monoammonium phosphate, diammonium phosphate, ammonium chloride, boric acid, hexabromocyclododecane, zinc borate, triphenyl phosphate, and polytetrafluoroethylene.

[0020] Wherein, the thickener is one of polyamide, polyester, white carbon black, bentonite, aluminum silicate, methyl cellulose, polyethylene glycol, natural rubber, hydroxyethyl cellulose, hydroxypropyl methyl cellulose and diatomaceous earth.

[0021] Wherein, the plasticizer is one of dioctyl sebacate, dioctyl adipate, tricresyl phosphate, chlorinated paraffin, epoxidized soybean oil, propylene glycol sebacate polyester, propylene glycol adipate polyester, diethylene glycol dibenzoate, coal tar, paraffin, liquid nitrile rubber, liquid polybutadiene, and liquid polyisobutylene.

[0022] Wherein, the thixotropic agent is one of polyamide wax, white carbon black, polyethylene wax, bentonite and hydrogenated castor oil.

[0023] Wherein, the filler is one of calcium carbonate, talc, clay, carbon black, white carbon black, mica, barium sulfate, calcium sulfate, aluminum oxide, titanium oxide, zinc oxide, magnesium oxide, glass fiber, and carbon fiber.

[0024] The method for preparing the conductive ink comprises the following steps:

[0025] (1) weighing and mixing liquid metal, conjugated polymer, and charge compensator according to a certain proportion, and then dispersing the liquid metal into micro-nano droplets;

[0026] (2) adding functional additives in proportion, stirring and mixing, and cooling to room temperature to obtain the conductive ink.

[0027] Wherein, in step (2), the mixing method is at least one of oscillation mixing, magnetic stirring mixing, mechanical stirring mixing, ultrasonic crushing mixing, three-roller mechanical mixing or planetary stirring mixing.

[0028] Working principle: The liquid metal used in the present invention generates a large amount of metal cations during the strong crushing process, which have a strong coordination effect with the negative charges carried by the charge compensator and the conjugated polymer. The micro-nano liquid metal droplets serve as the core and are wrapped by the conjugated polymer and the charge compensator as the shell to prevent the liquid metal droplets from aggregating with each other. The liquid metal plays a cross-linking role, and the strength of the conductive ink coating is relatively high. Both the liquid metal and the conjugated polymer have good conductivity, and the liquid metal has good fluidity. When the coating is damaged and cracks are generated, the liquid metal can repair the original conductive path and always keep the coating in a stable high-conductivity state. The large number of polar groups carried by the charge compensator can have a good wetting effect on the surface of the material, solving the problem that the liquid metal is difficult to wet the substrate. The core-shell structure can effectively prevent the leakage of metal cations and has high biocompatibility.

[0029] Beneficial effects: Compared with the prior art, the present invention has achieved the following significant effects: (1) Relying on the conductivity of liquid metal and conjugated polymer and the fluidity of liquid metal, the conductive path is always connected in a complex environment to obtain stable high conductivity with a conductivity of 1×10 4 ~1×10 6 S / m, and the rate of change of conductivity is ±5%; (2) the core-shell structure can effectively prevent the leakage of metal cations and improve biocompatibility; (3) the liquid metal droplets can play a cross-linking role, the product has high strength, good anti-destruction resistance, and is not easy to crack after coating; (4) the charge compensator has a good wetting effect on the surface of various substrates and has high biocompatibility; (5) the preparation method is simple, the cost is low, and the process is controllable. It has broad application prospects in modern electronic industries such as printed circuit boards, smart textiles, and flexible electronic devices, making industrial production possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a pattern printed on A4 paper using the conductive ink of Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The present invention is described in further detail below.

[0032] Example 1

[0033] The method for preparing the conductive ink based on liquid metal and conjugated polymer disclosed in the present invention comprises the following steps:

[0034] (1) According to the ratio in Table 1, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, metal gallium, and sodium alginate were weighed respectively, mixed together, and the liquid metal was dispersed into nano-scale droplets by ultrasonic crushing; wherein the power of the ultrasonic crushing was 250 W, and the time was 5 min;

[0035] (2) Add antioxidant 1706, light stabilizer 944, vinyl bisstearamide, and phosphite according to the ratio in Table 1, and mix by planetary stirring; wherein, stir at 1800 rpm for 120 s, and then stir at 2500 rpm for 90 s;

[0036] (3) After the conductive ink is coated and dried, the original conductivity σ0 is measured, and then 100 impact tests are performed, the conductivity σ1 is measured again, and the rate of change of conductivity y is calculated.

[0037] Performance characterization:

[0038] The conductive ink is coated on the surface of the material and dried. The original conductivity (σ0), the conductivity after 100 impact tests (σ1), and the conductivity change rate (y) are calculated to measure whether the conductivity of the conductive ink is stable, and y is defined as a relatively stable system between ±5%. The calculation formula is as follows:

[0039]

[0040] Example 2

[0041] The basic steps are the same as those in Example 1, and the specific parameters are shown in Table 1.

[0042] Example 3

[0043] The basic steps are the same as those in Example 1, and the specific parameters are shown in Table 1.

[0044] Example 4

[0045] The basic steps are the same as those in Example 1, and the specific parameters are shown in Table 1.

[0046] Table 1

[0047]

[0048] For Examples 1 to 4, the mass fractions of sodium alginate are 8%, 20%, 35%, and 81%, respectively, corresponding to the original conductivity σ0 of 9.8×10 4 S / m,7.3×10 4 S / m, 9.5×10 4 S / m, 9.2×10 5 S / m, and the conductivity σ1 after 100 impact tests was 8.6×10 4 S / m,7.6×10 4 S / m, 9.6×10 4 S / m,7.1×10 5S / m, and the rate of change y of conductivity are -12.2%, 4.1%, 1.1%, and -22.8% respectively.

[0049] Example 5

[0050] (1) According to the ratio in Table 2, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, gallium indium tin alloy, and sodium carboxymethyl cellulose were weighed respectively, mixed together, and the liquid metal was dispersed into nano-sized droplets by ultrasonic crushing; wherein the power of the ultrasonic crushing was 250 W, and the time was 5 min;

[0051] (2) Add the subsequent antioxidant 1706, liquid nitrile rubber, aluminum hydroxide, and phosphite according to the ratio in Table 2, and mix by planetary stirring; wherein, stir at 1800 rpm for 120 s, and then stir at 2500 rpm for 90 s;

[0052] (3) After the conductive ink is coated and dried, the original conductivity σ0 is measured; then, 100 impact tests are performed, the conductivity σ1 is measured again, and the conductivity change rate y is calculated.

[0053] Example 6

[0054] The basic steps are the same as those in Example 5, as shown in Table 2.

[0055] Example 7

[0056] The basic steps are the same as those in Example 5, as shown in Table 2.

[0057] Example 8

[0058] The basic steps are the same as those in Example 5, as shown in Table 2.

[0059] Table 2

[0060]

[0061] For Examples 5 to 8, the mass fractions of the gallium-indium-tin alloy are 7%, 28%, 40%, and 75%, respectively, corresponding to the original conductivity σ0 of 9.7×10 4 S / m, 8.8×10 5 S / m, 9.6×10 4 S / m,7.3×10 4 S / m, and the conductivity σ1 after 100 impact tests is 7.8×10 4 S / m, 8.6×10 5 S / m, 9.8×10 4 S / m, 8.2×10 4S / m, and the rate of change y of conductivity are -19.6%, -2.3%, 2.1%, and 12.3%, respectively.

[0062] Example 9

[0063] (1) According to the ratio in Table 3, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, gallium indium tin alloy, and sodium hyaluronate were weighed respectively, mixed together, and the liquid metal was dispersed into nano-sized droplets by ultrasonic crushing (power of 250 W, time of 5 min);

[0064] (2) Add the subsequent antioxidant 1706, light stabilizer 944, methyl silicone oil, phosphite, and polyethylene glycol according to the ratio in Table 3, and mix by planetary stirring; wherein, stir at 1800 rpm for 120 s, and then stir at 2500 rpm for 90 s;

[0065] (3) After the conductive ink is coated and dried, the original conductivity σ0 is measured, and then 100 impact tests are performed. The conductivity σ1 is measured again and the rate of change of conductivity y is calculated.

[0066] Example 10

[0067] The basic steps are the same as those in Example 9, as shown in Table 3.

[0068] Embodiment 11

[0069] The basic steps are the same as those in Example 9, as shown in Table 3.

[0070] Example 12

[0071] The basic steps are the same as those in Example 9, as shown in Table 3.

[0072] Table 3

[0073]

[0074] For Examples 9 to 12, the mass fractions of the light stabilizer 944 are 0%, 0.3%, 0.7%, and 2.3%, respectively, corresponding to the original conductivity σ0 of 9.0×10 3 s / m,9.5×10 4 s / m,8.7×10 5 s / m,9.1×10 5 s / m, and the conductivity σ1 after 100 impact tests is 8.1×10 3 s / m,9.2×10 4 s / m,8.4×10 5 s / m,9.7×10 5s / m, and the conductivity change rate y is -10%, -3.2%, -3.4% and 6.6% respectively.

[0075] The conductive ink of the present invention can achieve a conductivity of 1×10 4 ~1×10 6 S / m, good conductivity; 100 impact tests have proved that the conductivity change rate of the conductive ink is between ±5%, with high stability.

Claims

1. A conductive ink, characterized in that: It includes a positive charge center formed by liquid metal single substance or liquid metal alloy particles, and a negative charge shell formed by conjugated polymer and charge compensator on the surface of the positive charge center; it also includes functional additives; it contains the following components by weight: 10-70 parts of liquid metal, 1-30 parts of conjugated polymer, 10-80 parts of charge compensator, and 0.1-2 parts of functional additives; The conjugated polymer is one of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, polyacetylene, polypyrrole, poly(p-phenylene vinylene), poly(p-phenylene sulfide), poly(3-hexylthiophene), poly(3-octylthiophene), poly(3-cyclohexylthiophene), and poly(3-methyl-4-cyclohexylthiophene); The charge compensating agent is one of sodium alginate, potassium alginate, calcium alginate, ammonium alginate, methylcellulose, hydroxypropyl methylcellulose, sodium carboxymethylcellulose, sodium hyaluronate, potassium hyaluronate, gellan gum, nitrocellulose, sodium salicylate, thiosalicylic acid, and magnesium salicylate.

2. The conductive ink according to claim 1, characterized in that: The metal in the liquid metal element or alloy is a liquid metal in the range of 10°C to 300°C.

3. The conductive ink according to claim 1, characterized in that: The liquid metal single substance or liquid metal alloy particles are micro-nano-scale particles with a particle size ranging from 100 nm to 20 μm.

4. The conductive ink according to claim 1, characterized in that: The liquid metal includes gallium metal and gallium-based metal, and the gallium-based metal is composed of gallium metal and one or more of indium, tin, bismuth, zinc, aluminum, copper, gold, silver, titanium, vanadium, manganese, magnesium, calcium, platinum, cadmium, cobalt, nickel, and barium.

5. The conductive ink according to claim 1, characterized in that: The functional additive is at least one of an antioxidant, a heat stabilizer, a light stabilizer, a lubricant, a flame retardant, a thickener, a plasticizer, a thixotropic agent, and a filler.

6. A method for preparing the conductive ink according to claim 1, characterized in that: The following steps are involved: (1) Weighing and mixing liquid metal, conjugated polymer, and charge compensator according to a certain proportion, and then dispersing the liquid metal into micro-nano droplets; (2) Adding functional additives in proportion, stirring and mixing, and cooling to room temperature to obtain the conductive ink.

7. The method for preparing the conductive ink according to claim 6, characterized in that: The mixing method is at least one of oscillation mixing, magnetic stirring mixing, mechanical stirring mixing, ultrasonic crushing mixing, three-roller mechanical mixing or planetary stirring mixing.

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