Ink, ink preparation method and ink-jet printing method

Abstract

The invention belongs to the technical field of preparation of electronic ink and printing electronic devices, and relates to ink which comprises a dispersing agent and a silver-containing compound dispersed in the dispersing agent, and the dispersing agent comprises a reducing agent, a complexing agent and an aromatic ester compound. The invention also relates to a preparation method of the ink and an ink-jet printing method. The technical scheme provided by the invention can solve the problem of uniform appearance of a large-area printed film.

Description

Technical Field

[0001] The present application relates to the technical field of electronic ink and printed electronic device preparation, and more specifically, to an ink, a method for preparing an ink, and an inkjet printing method. Background Art

[0002] In the production process of electronic devices, inkjet printing has the characteristics of low cost, low waste and large-area display, and is currently a production technology with great advantages and potential. It can spray tiny droplets of functional materials from solutions to dispersions onto various substrates without causing any mechanical damage.

[0003] However, the ubiquitous coffee ring effect of inkjet-printed droplets can lead to uneven printing patterns, that is, the solute material tends to deposit on the edge of the droplet, causing the dried film to have a thick edge and thin center morphology. Since large-scale inkjet-printed films are composed of a large number of droplets, the uniform shape of the printed pattern will be affected when producing large-area films. Therefore, it is necessary to find a suitable inkjet printing ink to reduce the "coffee ring effect" of inkjet-printed films and improve the film molding uniformity and the conductive properties of the device. Summary of the invention

[0004] The technical problem to be solved by the present application is that the existing inkjet printing ink is prone to produce a coffee ring effect when the droplets formed by the ink being emitted onto the substrate evaporate, and cannot be used to prepare a large-area printed film with a uniform appearance.

[0005] In order to solve the above technical problems, the present application embodiment provides an ink, which adopts the following technical solution:

[0006] An ink comprises a dispersant and a silver-containing compound dispersed in the dispersant, wherein the dispersant comprises a reducing agent, a complexing agent and an aromatic ester compound.

[0007] Furthermore, the silver-containing compound is selected from at least one of fatty acid silver and aromatic acid silver;

[0008] Wherein, the fatty acid silver is selected from R1-COOAg and AgOOC-R2-COOAg, wherein R1 is a C1-C10 alkyl group and R2 is a C1-C10 alkylene group;

[0009] The aromatic silver acid is selected from Ar-COOAg, wherein Ar is selected from substituted or unsubstituted C6-C10 aryl groups, and the substituted substituent is selected from at least one of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogens, -NO2, -CN, and -NH2.

[0010] Further, the reducing agent is selected from at least one of C1-C6 fatty alcohols, glucose, tartaric acid, citric acid, ascorbic acid, formic acid and formaldehyde;

[0011] Optionally, the fatty alcohol includes methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, and glycerol.

[0012] Further, the complexing agent is selected from ammonia, R4-NH2, R5-NH-R6, At least one of the following, wherein R4, R5, R6, R7, R8, and R9 are selected from saturated or unsaturated groups of C1 to C20.

[0013] Furthermore, the aromatic ester compound is Ar-COOR 10 , wherein Ar is selected from substituted or unsubstituted C6-C10 aryl groups, the substituted substituents are selected from at least one of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogen, -NO2, -CN, and -NH2, and R 10 A saturated or unsaturated hydrocarbon group selected from C1 to C20.

[0014] Furthermore, the weight ratio of the reducing agent, the complexing agent and the aromatic ester compound is (3-4): (0.8-1): (1-2).

[0015] The present application also provides a method for preparing ink, which adopts the following technical solution:

[0016] A method for preparing ink, for preparing the ink as described above, comprises the following steps:

[0017] Provide silver-containing compounds, complexing agents, reducing agents, and aromatic ester compounds;

[0018] The complexing agent, the reducing agent and the aromatic ester compound are configured into a dispersant;

[0019] dispersing the silver-containing compound in the dispersant to form a mixed solution;

[0020] The mixed solution is filtered to obtain the ink.

[0021] Further, the ink has a viscosity in the range of 5 mPas to 8 mPas, a surface tension in the range of 29 dyn / cm to 31 dyn / cm, and a metal loading of 19%;

[0022] And / or, after filtering the mixed solution, the ink is continuously stirred.

[0023] The present application also provides an inkjet printing method, which adopts the following technical solution:

[0024] An inkjet printing method, characterized in that it comprises the following steps:

[0025] Introducing ink into an inkjet printing device, wherein the ink is the ink described above, or is prepared by the ink preparation method described above;

[0026] Inkjet printing is performed on a substrate along a set direction at a set emission frequency, wherein the substrate is heated during inkjet printing.

[0027] Furthermore, the setting transmission frequency is 3kHz to 5kHz;

[0028] and / or, the heating temperature of the substrate is in the range of 60°C to 80°C;

[0029] And / or, after the inkjet printing is performed on the substrate along the set direction at the set emission frequency, the following steps are further included:

[0030] The inkjet-printed substrate is subjected to high temperature treatment to form conductive circuits.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] The ink provided by the present application mixes a reducing agent, a complexing agent and an aromatic ester compound to form a dispersant. The viscosity of the ink is adjusted by controlling the ratio of the reducing agent to the aromatic ester compound, thereby adjusting the fluidity of the ink. Before the ink dries to form a coffee ring effect, the two adjacent inks influence each other, thereby improving the uniformity of the morphology of the tiny droplets. In addition, by utilizing the high boiling point characteristics of the aromatic ester compound, the morphology of the ink can be guaranteed, and the uniformity of the ink distribution is greatly improved during large-area printing. Using a silver-containing compound as a solute can provide a better morphology, so as to facilitate the formation of an electrode with a lower resistivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the solutions in the present application or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 is a flow chart of a method for preparing ink according to an embodiment of the present application;

[0035] Figure 2 is a flow chart of the inkjet printing method of an embodiment of the present application;

[0036] Figure 3 is a schematic structural diagram of an inkjet printing device according to an embodiment of the present application;

[0037] Figure 4 It is a schematic diagram of the structural change state of two adjacent tiny droplets along the printing direction of an embodiment of the present application.

[0038] Reference numerals:

[0039] 1. Inkjet printing equipment; 11. Inkjet head; 2. Substrate; 3. Tiny droplets; 31. Peripheral area. DETAILED DESCRIPTION

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] Embodiments of the ink of the present application

[0043] An embodiment of the present application provides an ink, comprising a dispersant and a silver-containing compound dispersed in the dispersant, wherein the dispersant comprises a complexing agent, a reducing agent and an aromatic ester compound.

[0044] In this embodiment, the viscosity of the ink at room temperature is in the range of 5 mPas to 8 mPas, the surface tension is in the range of 29 dyn / cm to 31 dyn / cm, and the metal loading is 19%.

[0045] The ink provided in the embodiment of the present application is prepared by mixing a reducing agent, a complexing agent and an aromatic ester compound to form a dispersant. The viscosity of the ink is adjusted by controlling the proportion of the reducing agent and the aromatic ester compound in the dispersant, thereby adjusting the fluidity of the ink. Before the ink dries to form a coffee ring effect, the two adjacent inks are allowed to influence each other, thereby improving the morphology uniformity of the tiny droplets. In addition, by utilizing the high boiling point characteristics of the aromatic ester compound, the morphology of the ink can be guaranteed, and the ink distribution uniformity is greatly improved during large-area printing. Using a silver-containing compound as a solute can provide a better morphology, so as to facilitate the formation of an electrode with a lower resistivity.

[0046] In some embodiments, the silver-containing compound is selected from at least one of fatty acid silver and aromatic acid silver.

[0047] In some embodiments, the silver fatty acid is selected from at least one of R1-COOAg and AgOOC-R2-COOAg, wherein R1 is a C1-C10 alkyl group, and R2 is a C1-C10 alkylene group.

[0048] Among them, the alkyl group includes a straight-chain alkyl group or a branched alkyl group, the C1-C10 alkyl group generally refers to an alkyl group including 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms, and the alkyl group can specifically be methyl, ethyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl.

[0049] The alkylene group includes a straight chain alkylene group or a branched chain alkylene group. The C1-C10 alkylene group generally refers to an alkylene group including 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. The alkylene group can be a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, or the like.

[0050] In some embodiments, the aromatic silver acid is selected from Ar-COOAg, wherein Ar is selected from substituted or position-substituted C6-C10 aryl groups, and the substituted substituents are selected from at least one of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogens, -NO2, -CN, and -NH2. The C6-C10 aryl groups may be phenyl, tolyl, xylyl (o, p, m), ethylphenyl, 2-methyl-3-ethylphenyl, propylphenyl, butylphenyl, and the like.

[0051] The C1-C6 alkyl group may be methyl, ethyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, or the like.

[0052] The C1-C6 alkoxy group may be a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, or a hexyloxy group.

[0053] The halogen is selected from fluorine, chlorine, bromine and iodine.

[0054] In this embodiment, the silver-containing compound is preferably at least one of silver benzoate, silver acetate, silver propionate, silver valerate, silver hexanoate, silver heptanoate, and silver decanoate.

[0055] In some embodiments, the reducing agent is selected from at least one of C1-C6 fatty alcohols, glucose, tartaric acid, citric acid, ascorbic acid, formic acid and formaldehyde.

[0056] Optionally, the fatty alcohol may be methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, or glycerol.

[0057] In this embodiment, the reducing agent is preferably ethanol.

[0058] In some embodiments, the complex is selected from ammonia, R4-NH2, R5-NH-R6,

[0059] Among them, R4, R5, R6, R7, R8, and R9 are selected from saturated or unsaturated hydrocarbon groups of C1 to C20.

[0060] In some embodiments, the C1-C20 saturated hydrocarbon group may be methyl, ethyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclohexyl, or the like.

[0061] In some embodiments, the C1-C20 unsaturated hydrocarbon group may be phenyl, tolyl, xylyl (o-, p-, m-), ethylphenyl, 2-methyl-3-ethylphenyl, propylphenyl, butylphenyl, and the like.

[0062] In this embodiment, the complex is preferably octylamine.

[0063] In some embodiments, the aromatic ester compound is Ar-COOR 10 , wherein Ar is selected from substituted or unsubstituted C6-C10 aryl groups, the substituted substituents are selected from one or more of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogen, -NO2, -CN, -NH2, R 10 A saturated or unsaturated hydrocarbon group selected from C1-C20.

[0064] In some embodiments, the C6-C10 aryl group may be phenyl, naphthyl, etc.; the C1-C6 alkyl group may be methyl, ethyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, etc.; the C1-C6 alkoxy group may be methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy; the halogen is selected from fluorine, chlorine, bromine and iodine.

[0065] In this embodiment, the C6-C10 aromatic group is preferably a phenyl group, the aromatic ester compound is a benzoate compound, and the benzoate compound can be at least one of alkyl benzoate, cycloalkyl benzoate, aromatic benzoate, alkoxybenzoate and alkyl benzoate.

[0066] Wherein, R 10 Preferably it is a saturated or unsaturated hydrocarbon group of C1 to C8, more preferably a saturated or unsaturated hydrocarbon group of C1 to C4, such as methyl benzoate, ethyl benzoate, n-propyl benzoate, isopropyl benzoate, n-butyl benzoate, isobutyl benzoate, n-pentyl benzoate, isopentyl benzoate, n-hexyl benzoate, n-octyl benzoate, 2-ethylhexyl benzoate, vinyl benzoate and allyl benzoate.

[0067] The R 10 It is usually selected from a saturated hydrocarbon group of C3 to C8, preferably a saturated hydrocarbon group of C5 to C6, such as cyclopentyl benzoate and cyclohexyl benzoate.

[0068] The R 10 Usually selected from C6-C10 aromatic groups, such as: with halogen and / or a C1-C4 aromatic group, specifically: phenyl benzoate, 4-toluyl benzoate, benzyl benzoate, styrene benzoate, 2-chlorophenyl benzoate, 4-chlorophenyl benzoate.

[0069] The substituent of the phenyl group in the alkoxybenzoate is usually selected from C1-C4 alkyl groups, preferably methyl or ethyl. 10 The same as the above-mentioned saturated or unsaturated hydrocarbon groups, such as: methyl anisate, ethyl anisate, isopropyl anisate, isobutyl anisate, phenyl anisate, benzyl anisate, ethyl o-methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, n-butyl p-ethoxybenzoate, ethyl p-allyloxybenzoate, phenyl p-ethoxybenzoate, methyl o-ethoxybenzoate, ethyl 3,4-dimethoxybenzoate.

[0070] The alkylbenzene in the alkyl benzoate is usually selected from C6 to C8 alkylbenzene, preferably phenyl, tolyl or xylyl (o, p, m), such as: methyl p-toluate, ethyl p-toluate, isopropyl p-toluate, n-pentyl or isopentyl p-toluate, allyl p-toluate, phenyl p-toluate, 2-toluyl p-toluate, ethyl p-toluate, and ethyl m-toluate.

[0071] In this embodiment, the material of the aromatic ester compound is selected from at least one of ethyl benzoate (boiling point is 212.6°C), methyl benzoate (boiling point is 198°C), n-pentyl benzoate (boiling point is 268.82°C), phenyl benzoate (boiling point is 299°C), and n-octyl benzoate (boiling point is 320.7°C).

[0072] In some embodiments, the weight ratio of the complexing agent, the reducing agent and the aromatic ester compound is (3-4): (0.8-1): (1-2);

[0073] In this embodiment, the complexing agent is octylamine (99.0%, OA), the reducing agent is ethanol (99.5%, ET), the aromatic ester compound is ethyl benzoate, and the weight ratio of octylamine, ethanol and aromatic ester compound is 4:0.8:1.

[0074] In other embodiments, the weight ratio of octylamine, ethanol and aromatic ester compounds can also be 3:0.8:1, 4:1:1, 4:0.8:1.5, 4:1:2, etc.

[0075] The embodiments of the present application optimize the printability of the ink by controlling the proportions of the reducing agent and the aromatic ester compound in the dispersant.

[0076] In the embodiment of the present application, the dispersant is a mixture of a reducing agent, a complexing agent and an aromatic ester compound that are soluble in each other. Since the dispersant contains a reducing agent, the ink formula can be simplified, thereby simplifying the ink preparation method; by adding a complexing agent, the silver-containing compound can be fully and evenly dispersed in the dispersant, thereby improving the uniformity of the ink during inkjet printing; by adding a high-boiling point aromatic ester compound, the boiling point of the dispersant is increased, and during the inkjet printing process, the time for the ink to form a coffee ring effect is extended, so that the two adjacent inks affect each other and improve the morphological uniformity of the ink. In addition, the aromatic ester compound has good antioxidant properties and can play the same role as the reducing agent, thereby simplifying the ink formula.

[0077] Embodiment of the method for preparing the ink of the present application

[0078] See also Figure 1As shown, the embodiment of the present application provides a method for preparing an ink, which is used to prepare the ink as described above, comprising the following steps:

[0079] Step S101, providing a silver-containing compound, a complexing agent, a reducing agent, and an aromatic ester compound.

[0080] In this embodiment, the silver-containing compound is silver benzoate (C7H5AgO2), and the silver-containing compound can be directly prepared by using finished powder or by the following method:

[0081] Provide silver nitrate (99.8%, AgNO3) and benzoic acid (99.5%, C7H6O2);

[0082] Mix 1.25 g of silver nitrate with 0.65 g of benzoic acid to obtain water-insoluble silver benzoate powder;

[0083] The silver benzoate powder is washed and dried.

[0084] The complexing agent is octylamine (99.0%, OA), the reducing agent is ethanol (99.5%, ET), and the aromatic ester compound is ethyl benzoate (C9H 10 O2), wherein the boiling point of ethyl benzoate is 212.6°C.

[0085] Step S102, preparing a dispersant by combining a complexing agent, a reducing agent and an aromatic ester compound.

[0086] In this embodiment, octylamine, ethanol and ethyl benzoate are mixed in a weight ratio of 4 mL:0.8 mL:1 mL to prepare a dispersant.

[0087] Step S103, dispersing the silver-containing compound in the dispersant to form a mixed solution.

[0088] In this embodiment, silver benzoate is dispersed in a dispersant (OA:ET:C9H 10 O2=4mL:0.8mL:1mL) and continued stirring at 25°C.

[0089] Step S104, filtering the mixed solution to obtain the ink.

[0090] In some embodiments, the filter used to filter the mixed solution adopts a filter head of 0.22 μm to 0.45 μm for filtering, and the filter head can be 0.22 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, or 0.45 μm.

[0091] In this embodiment, a filter with a 0.22 μm filter head is used for filtration.

[0092] In this embodiment, the following steps are also included:

[0093] The ink filtered in step S104 is continuously stirred to prevent the ink from gelling.

[0094] The viscosity of the ink prepared by the above steps S101 to S104 is in the range of 5mPas to 8mPas, the surface tension is in the range of 29dyn / cm to 31dyn / cm, the metal loading is 19%, and the odor is relatively mild, which will not cause much harm to the human body and the environment. It is suitable for ordinary home printers, and the prepared circuit has good conductivity.

[0095] The ink prepared by the ink preparation method provided in the embodiment of the present application uses octylamine, ethanol and ethyl benzoate mixed in a set ratio as a dispersant, and the viscosity of the ink is adjusted by adjusting the proportion of ethanol and ethyl benzoate in the dispersant to adapt to different models of printers. In addition, the high boiling point characteristic of ethyl benzoate increases the temperature required for the ink to be fully dried, and prolongs the time for the ink to form a coffee ring effect, so that the two adjacent inks affect each other, improving the morphological uniformity of the ink, which is conducive to the preparation of a large-area printed film with a uniform appearance. The use of a silver-containing compound as a solute can provide a better morphology to facilitate the formation of an electrode with a lower resistivity.

[0096] Embodiment of the inkjet printing method of the present application

[0097] See also Figure 2 As shown, the embodiment of the present application provides an inkjet printing method, which specifically includes the following steps:

[0098] Step S100, introducing ink into an inkjet printing device, wherein the ink is the ink described above or is prepared by the ink preparation method described above.

[0099] In this embodiment, a constant temperature structure is further provided in the inkjet printing device, through which the internal temperature of the inkjet printing device and the temperature of the inkjet head are maintained in the range of 60°C to 80°C, maintaining the sol state of the ink. The viscosity of the ink at normal temperature is in the range of 5mPas to 8mPas, the surface tension is in the range of 29dyn / cm to 31dyn / cm, and the metal loading is 19%.

[0100] In some embodiments, the ink includes a dispersant and a silver-containing compound dispersed in the dispersant, wherein the dispersant includes a reducing agent, a complexing agent, and an aromatic ester compound.

[0101] The silver-containing compound is silver benzoate (C7H5AgO2).

[0102] The reducing agent, the complexing agent and the aromatic ester compound are mixed in a set weight ratio to form a dispersant, wherein the set weight ratio is complexing agent: reducing agent: aromatic ester compound = (3-4): (0.8-1): (1-2).

[0103] In this embodiment, the set weight ratio is complexing agent: reducing agent: aromatic ester compound = 4:0.8 to 1:1.

[0104] In other embodiments, the set weight ratio may also be complexing agent: reducing agent: aromatic ester compound = 3:0.8:1.

[0105] The weight ratio of octylamine, ethanol and aromatic ester compound can also be 4:1:1.

[0106] The weight ratio of octylamine, ethanol and aromatic ester compounds can also be 4:0.8:1.5.

[0107] The weight ratio of octylamine, ethanol and aromatic ester compound can also be 4:1:2.

[0108] Step S200 , performing inkjet printing on a substrate along a set direction at a set emission frequency, wherein the substrate is heated during inkjet printing.

[0109] In this example, see Figure 3 As shown, the X direction is the printing direction of the inkjet head 11 of the inkjet printing device 1, the Y direction is the diffusion direction of the tiny droplets, and the Z direction is the lifting direction of the inkjet head 11 of the inkjet printing device 1. The configured ink is introduced into the inkjet printing device 1, and the inkjet head 11 of the inkjet printing device 1 outputs tiny droplets (≈10pL) to the substrate 2 along the X direction at an emission frequency of 5kHz. While the inkjet head 11 outputs the tiny droplets, a heating device is used to heat the substrate 2 to enhance the evaporation effect of the tiny droplets, so that the peripheral area of ​​the tiny droplets is quickly converted into a gel state.

[0110] In this embodiment, since the dispersant contains ethyl benzoate with a relatively high boiling point, when the tiny droplets formed by the ink are inkjet printed on the substrate 2, the drying rate of the tiny droplets is relatively slow, and the tiny droplets diffuse outward under the action of the fluidity of the ink.

[0111] See also Figure 4As shown, during the inkjet printing process of the inkjet printing device 1 along the X direction, there are multiple tiny droplets 3 on the substrate 2 along the X direction, wherein the tiny droplets 3 formed by the ink can influence each other, specifically, the first tiny droplet 3 is located on the substrate, and due to the higher boiling point of its dispersant, the ink is kept to have good fluidity, and the peripheral area 31 of the tiny droplet diffuses outwards, and the second tiny droplet 3 just drops on the substrate, and there is a gap between the first tiny droplet 3 and the second tiny droplet 3, and then, the peripheral area 31 of the second tiny droplet 3 diffuses outwards and contacts the peripheral area 31 of the first tiny droplet 3, thereby eliminating the coffee ring effect between the two adjacent tiny droplets 3, thereby optimizing the printing morphology of the printing pattern along the X direction, and the formed film is flat, and no coffee ring phenomenon is generated along the X direction.

[0112] The inkjet printing method provided in the embodiment of the present application uses ink as the inkjet printing material and performs inkjet printing on a substrate 2. When a previous tiny droplet 3 falls on the substrate 2, the peripheral area 31 of the previous tiny droplet 3 maintains good ink fluidity. Subsequently, the next tiny droplet 3 contacts the previous tiny droplet 3 to eliminate the coffee ring effect of the printed pattern along the printing direction, thereby achieving a uniform distribution of the printed pattern along the printing direction, so that a large-area printed film has a uniform shape along the printing direction.

[0113] In this embodiment, after the step S200 performs inkjet printing on the substrate along a set direction at a set emission frequency, the following steps are further included:

[0114] The inkjet-printed substrate is subjected to high temperature treatment to form conductive circuits.

[0115] In this embodiment, the substrate after inkjet printing is sintered at a temperature of 130-150° C. for 10 to 20 minutes to form a thin film, and the printed pattern formed by inkjet printing on the substrate forms a conductive circuit, which is used as an electrode in thin film transistors (TFTs), light-emitting devices, and solar cells.

[0116] The above scheme is further described below in conjunction with specific embodiments. The preferred embodiments of the present invention are described in detail as follows:

[0117] Example 1

[0118] (1) Mix 1.25 g of silver nitrate (99.8%, AgNO3) and 0.65 g of benzoic acid (99.5%, C7H6O2) to obtain a water-insoluble silver compound.

[0119] (2) Collect the above metal compounds, wash and dry them to obtain silver benzoate powder.

[0120] ⑶ Octylamine (99.0%, OA), ethanol (99.5%, ET) and ethyl benzoate (C9H 10 O2) were mixed in a weight ratio of 4mL:0.8mL:1mL to form a dispersant.

[0121] (4) Add the washed and dried silver benzoate powder to the dispersant and continue stirring at 25° C. until the silver benzoate powder is completely dispersed in the dispersant to form a mixed solution.

[0122] (5) Filter the mixed solution using a filter with a 0.22 μm filter head to obtain silver benzoate ink.

[0123] ⑹Continuously stir the filtered silver benzoate ink to avoid gel formation.

[0124] ⑺ Adding silver benzoate ink to the inkjet printing device;

[0125] ⑻ Inkjet printing is performed on the substrate at an emission frequency of 5 kHz along the X direction, wherein the substrate is continuously heated during inkjet printing.

[0126] ⑼ The substrate after inkjet printing is subjected to a sintering treatment at 140° C. for 10 to 20 minutes to form a thin film.

[0127] Example 2

[0128] (1) Mix 1.25 g of silver nitrate (99.8%, AgNO3) and 0.65 g of benzoic acid (99.5%, C7H6O2) to obtain a water-insoluble silver compound.

[0129] (2) Collect the above metal compounds, wash and dry them to obtain silver benzoate powder.

[0130] ⑶ Octylamine (99.0%, OA), ethanol (99.5%, ET) and ethyl benzoate (C9H 10 O2) were mixed in a weight ratio of 3 mL:0.8 mL:1 mL to form a dispersant.

[0131] (4) Add the washed and dried silver benzoate powder to the dispersant and continue stirring at 25° C. until the silver benzoate powder is completely dispersed in the dispersant to form a mixed solution.

[0132] (5) Filter the mixed solution using a filter with a 0.22 μm filter head to obtain silver benzoate ink.

[0133] ⑹Continuously stir the filtered silver benzoate ink to avoid gel formation.

[0134] ⑺ Adding silver benzoate ink to the inkjet printing device;

[0135] ⑻ Inkjet printing is performed on the substrate at an emission frequency of 5 kHz along the X direction, wherein the substrate is continuously heated during inkjet printing.

[0136] ⑼ The substrate after inkjet printing is subjected to a sintering treatment at 140° C. for 10 to 20 minutes to form a thin film.

[0137] Example 3

[0138] (1) Mix 1.25 g of silver nitrate (99.8%, AgNO3) and 0.65 g of benzoic acid (99.5%, C7H6O2) to obtain a water-insoluble silver compound.

[0139] (2) Collect the above metal compounds, wash and dry them to obtain silver benzoate powder.

[0140] ⑶ Octylamine (99.0%, OA), ethanol (99.5%, ET) and ethyl benzoate (C9H 10 O2) were mixed in a weight ratio of 4mL:1mL:1mL to form a dispersant.

[0141] (4) Add the washed and dried silver benzoate powder to the dispersant and continue stirring at 25° C. until the silver benzoate powder is completely dispersed in the dispersant to form a mixed solution.

[0142] (5) Filter the mixed solution using a filter with a 0.22 μm filter head to obtain silver benzoate ink.

[0143] ⑹Continuously stir the filtered silver benzoate ink to avoid gel formation.

[0144] ⑺ Adding silver benzoate ink to the inkjet printing device;

[0145] ⑻ Inkjet printing is performed on the substrate at an emission frequency of 5 kHz along the X direction, wherein the substrate is continuously heated during inkjet printing.

[0146] ⑼ The substrate after inkjet printing is subjected to a sintering treatment at 140° C. for 10 to 20 minutes to form a thin film.

[0147] Example 4

[0148] (1) Mix 1.25 g of silver nitrate (99.8%, AgNO3) and 0.65 g of benzoic acid (99.5%, C7H6O2) to obtain a water-insoluble silver compound.

[0149] (2) Collect the above metal compounds, wash and dry them to obtain silver benzoate powder.

[0150] ⑶ Octylamine (99.0%, OA), ethanol (99.5%, ET) and ethyl benzoate (C9H 10 O2) were mixed in a weight ratio of 4mL:0.8mL:1.5mL to form a dispersant.

[0151] (4) Add the washed and dried silver benzoate powder to the dispersant and continue stirring at 25° C. until the silver benzoate powder is completely dispersed in the dispersant to form a mixed solution.

[0152] (5) Filter the mixed solution using a filter with a 0.22 μm filter head to obtain silver benzoate ink.

[0153] ⑹Continuously stir the filtered silver benzoate ink to avoid gel formation.

[0154] ⑺ Adding silver benzoate ink to the inkjet printing device;

[0155] ⑻ Inkjet printing is performed on the substrate at an emission frequency of 5 kHz along the X direction, wherein the substrate is continuously heated during inkjet printing.

[0156] ⑼ The substrate after inkjet printing is subjected to a sintering treatment at 140° C. for 10 to 20 minutes to form a thin film.

[0157] Example 5

[0158] (1) Mix 1.25 g of silver nitrate (99.8%, AgNO3) and 0.65 g of benzoic acid (99.5%, C7H6O2) to obtain a water-insoluble silver compound.

[0159] (2) Collect the above metal compounds, wash and dry them to obtain silver benzoate powder.

[0160] ⑶ Octylamine (99.0%, OA), ethanol (99.5%, ET) and ethyl benzoate (C9H 10 O2) were mixed in a weight ratio of 4mL:1mL:2mL to form a dispersant.

[0161] (4) Add the washed and dried silver benzoate powder to the dispersant and continue stirring at 25° C. until the silver benzoate powder is completely dispersed in the dispersant to form a mixed solution.

[0162] (5) Filter the mixed solution using a filter with a 0.22 μm filter head to obtain silver benzoate ink.

[0163] ⑹Continuously stir the filtered silver benzoate ink to avoid gel formation.

[0164] ⑺ Adding silver benzoate ink to the inkjet printing device;

[0165] ⑻ Inkjet printing is performed on the substrate at an emission frequency of 5 kHz along the X direction, wherein the substrate is continuously heated during inkjet printing.

[0166] ⑼ The substrate after inkjet printing is subjected to a sintering treatment at 140° C. for 10 to 20 minutes to form a thin film.

[0167] Comparative Example 1

[0168] ⑴ Through the liquid phase chemical reduction method, silver nitrate (AgNO3) is used as an oxidant, sodium borohydride (NaBH4) and sodium hydroxide (NaOH) are used as composite reducing agents, and polyvinyl pyrrolidone (PVP) is used as a dispersant to prepare uniform and well-dispersed nanosilver particles, wherein the particle size of the nanosilver particles is 40nm to 70nm.

[0169] ⑵ Mix ultrapure water and diethylene glycol to form a dispersant.

[0170] ⑶ Dissolve the above-mentioned nano silver particles in a dispersant to form a water-based conductive ink.

[0171] (4) The water-based conductive ink is added to a piezoelectric inkjet printer and inkjet printing is performed on the substrate.

[0172] (5) After inkjet printing, the substrate is sintered at 150°C for 10 to 20 minutes to form a thin film.

[0173] Test result analysis:

[0174] The inks prepared by the preparation methods of Examples 1 to 5 and Comparative Example 1 and the formed films were subjected to performance tests. At room temperature (25° C.), the viscosity of the inks was tested using a standard viscosity tester, the surface tension of the inks was tested using a drop weight tester, and the resistivity of the formed films was tested using a resistivity tester. The test results are as follows:

[0175] The silver benzoate ink prepared by the preparation method of Example 1 has a viscosity of 5 mPas at room temperature and a surface tension of 30 dyn / cm. The resistivity of the conductive circuit obtained by inkjet printing of the silver benzoate ink is 2.59 μΩ·cm when tested by a resistivity tester.

[0176] The viscosity of the silver benzoate ink obtained by the preparation method of Example 2 is within the range of 4.9 mPas at room temperature, and the surface tension is within the range of 30 dyn / cm. The resistivity of the conductive circuit obtained by inkjet printing of the silver benzoate ink is 2.59 μΩ·cm when tested by a resistivity tester.

[0177] The viscosity of the silver benzoate ink obtained by the preparation method of Example 3 is within the range of 6 mPas at room temperature, and the surface tension is within the range of 31 dyn / cm. The resistivity of the conductive circuit obtained by inkjet printing of the silver benzoate ink is 2.59 μΩ·cm when tested by a resistivity tester.

[0178] The viscosity of the silver benzoate ink obtained by the preparation method of Example 4 is within the range of 6.5 mPas at room temperature, and the surface tension is within the range of 30.6 dyn / cm. The resistivity of the conductive circuit obtained by inkjet printing of the silver benzoate ink is 2.59 μΩ·cm when tested by a resistivity tester.

[0179] The viscosity of the silver benzoate ink obtained by the preparation method of Example 5 is within the range of 8 mPas at room temperature, and the surface tension is within the range of 32 dyn / cm. The resistivity of the conductive circuit obtained by inkjet printing of the silver benzoate ink is 2.59 μΩ·cm when tested by a resistivity tester.

[0180] The viscosity of the water-based conductive ink obtained in Comparative Example 1 at room temperature is 2.5 mPas, and the surface tension is 32.3 dyn / cm. The resistivity of the conductive circuit obtained by testing with a resistivity tester is 16.5 μΩcm.

[0181] From the comparison between the above-mentioned Examples 1 to 5 and Comparative Example 1, it can be seen that the silver benzoate ink prepared in this embodiment has high viscosity and low surface tension at room temperature, and as the proportion of ethanol and ethyl benzoate in the dispersant increases, the viscosity of the prepared ink increases, indicating that it can form tiny ink droplets in a gel state with better morphology. Due to the low surface tension, the tiny ink droplets are in the gel state for a longer time, so that they can be converted into a sol state in time to avoid the common sense of the coffee ring effect. In addition, the resistivity of the film formed in this embodiment is much lower than that of the comparative example, showing a more excellent conductive property.

[0182] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. An ink, characterized in that: The ink comprises a dispersant and a silver-containing compound dispersed in the dispersant, wherein the dispersant comprises a reducing agent, a complexing agent and an aromatic ester compound.

2. The ink according to claim 1, characterized in that The silver-containing compound is selected from at least one of fatty acid silver and aromatic acid silver; The silver fatty acid is selected from at least one of R1-COOAg and AgOOC-R2-COOAg, wherein R1 is a C1-C10 alkyl group and R2 is a C1-C10 alkylene group; The aromatic silver acid is selected from Ar-COOAg, wherein Ar is selected from substituted or unsubstituted C6-C10 aryl groups, and the substituted substituents are selected from one or more of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogens, -NO2, -CN, and -NH2.

3. The ink according to claim 1, characterized in that The reducing agent is selected from at least one of C1-C6 fatty alcohols, glucose, tartaric acid, citric acid, ascorbic acid, formic acid and formaldehyde; Optionally, the fatty alcohol includes methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, and glycerol.

4. The ink according to claim 1, characterized in that The complexing agent is selected from ammonia, R4-NH2, R5-NH-R6, Among them, R4, R5, R6, R7, R8, and R9 are selected from saturated or unsaturated hydrocarbon groups of C1 to C20.

5. The ink according to claim 1, characterized in that The aromatic ester compound is Ar-COOR 10 , wherein Ar is selected from substituted or unsubstituted C6-C10 aryl groups, the substituted substituents are selected from one or more of C1-C6 alkyl groups, C1-C6 alkoxy groups, halogen, -NO2, -CN, -NH2, R 10 A saturated or unsaturated hydrocarbon group selected from C1-C20.

6. The ink according to claims 1 to 5, characterized in that The weight ratio of the reducing agent, the complexing agent and the aromatic ester compound is (3-4): (0.8-1): (1-2).

7. A method for preparing ink, characterized in that: The following steps are involved: Provide silver-containing compounds, complexing agents, reducing agents, and aromatic ester compounds; The complexing agent, the reducing agent and the aromatic ester compound are configured into a dispersant; dispersing the silver-containing compound in the dispersant to form a mixed solution; The mixed solution is filtered to obtain the ink.

8. The method for preparing ink according to claim 7, characterized in that: The ink has a viscosity in the range of 5 mPas to 8 mPas, a surface tension in the range of 29 dyn / cm to 31 dyn / cm, and a metal loading of 19%; And / or, after filtering the mixed solution with a filter, the ink is continuously stirred.

9. An inkjet printing method, characterized in that: The following steps are involved: Introducing ink into an inkjet printing device, wherein the ink is the ink according to any one of claims 1 to 6, or is prepared by the method for preparing the ink according to any one of claims 7 to 8; Inkjet printing is performed on a substrate along a set direction at a set emission frequency, wherein the substrate is heated during inkjet printing.

10. The inkjet printing method according to claim 9, characterized in that: The setting transmission frequency is 3kHz to 5kHz; And / or, the heating temperature of the substrate is in the range of 60°C to 80°C. And / or, after the inkjet printing is performed on the substrate along the set direction at the set emission frequency, the following steps are further included: The substrate after inkjet printing is subjected to high temperature treatment to form conductive circuits.

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