Modified nano conductive particle, modified composition and modification method thereof, and application of modified nano conductive particle in conductive slurry

Abstract

The invention belongs to the field of conductive material modification, and particularly relates to a modified composition for modifying nano conductive particles, which comprises a component A and a component B, wherein the component A comprises at least one compound with a structure as shown in a formula 1; the component B comprises at least one compound with a structure shown in a formula 2; wherein the melting point of the component A is below 50 DEG C; and the boiling point of the component B is 180 DEG C or less. The invention also comprises preparation of the composite material and application of the composite material in modification of nano conductive particles. Innovative research shows that the component A and the component B are combined, synergism can be achieved, when the component A and the component B are used for surface modification of the conductive nano-particles, the surface resistance of the conductive nano-particles can be reduced, in addition, the dispersity and the machinability of the conductive nano-particles can be improved, and the application scene of the conductive nano-particles can be improved.

Description

Technical Field

[0001] This invention belongs to the field of conductive pastes, specifically to the field of nano-conductive particle modification. Background Technology

[0002] The application of nano-conductive powders in low-temperature slurries is limited due to their tendency to agglomerate and high viscosity. Currently, there are few reports on low-temperature slurries prepared using a single nano-powder without any micron-sized powder.

[0003] To address this issue, existing technologies have also provided some modification schemes for conductive particles, for example, [the following is a list of related technologies, not part of the main text].

[0004] Chinese patent document CN116179007A discloses a method for preparing water-dispersible conductive aluminum powder, specifically describing the grafting of nano-conductive materials onto the surface of modified aluminum powder using a silane coupling agent to improve its conductivity. For example, Chinese patent document CN117925013A discloses a high-adhesion conductive ink, specifically disclosing a scheme for modifying particles using a modifier prepared by free polymerization with maleic anhydride monoester as the anchoring group, butyl methacrylate as the solvation chain, and styrene as the functional group. Chinese patent document CN116748509A discloses a method for preparing coated silver nanoparticles, including the following steps: uniformly mixing silver nitrate solution and water-soluble carbon material, and carrying out a hydrothermal reaction under closed conditions at 120-160°C to obtain coated silver nanoparticles. Chinese patent document CN101710497A reports the use of nano-silver powder as a functional phase to prepare a slurry; however, its resistivity is below 10... -5 The Ω·cm level greatly limits some applications that require high conductivity.

[0005] In summary, although there are some existing technologies for modifying conductive particles, the surface resistivity of these technologies is still relatively high, and the processability of the modification process and the application of the materials still need to be improved. Summary of the Invention

[0006] To address the existing problems, the primary objective of this invention is to provide a modified composition for modifying nano-conductive particles, which aims to prevent the agglomeration of nano-conductive particles, reduce their surface resistance, and improve their dispersibility and processability.

[0007] A second objective of this invention is to provide the modified conductive nanoparticles comprising the modified composition, a method for preparing the same, and their application in conductive slurries.

[0008] A third objective of this invention is to provide a conductive slurry comprising the modified nano-conductive particles.

[0009] A modified composition for modifying nano-conductive particles comprises component A and component B; wherein component A comprises at least one compound of formula 1; component B comprises at least one compound of formula 2; wherein the melting point of component A is below 50°C; and the boiling point of component B is below 180°C.

[0010]

[0011] R1 to R4 are individually C1 to C 18 The alkyl group, and / or two or more substituents from R1 to R4, cyclize to form a five-membered or more N-containing heterocycle; wherein A is an anion, and n is the charge number of the anion;

[0012] At least one substituent in R5 to R7 is C1 to C2. 18 The alkyl group is a substituent of H, C1-C6 alkyl groups, or amine-substituted alkyl groups.

[0013] This invention innovatively demonstrates that by combining components A and B, a synergistic effect can be achieved. When used to modify the surface of conductive nanoparticles, it can reduce their surface resistance, improve their dispersibility and processability, and broaden their application scenarios.

[0014] In this invention, Formula 1 includes compounds of Formula 1-A and / or Formula 1-B;

[0015]

[0016] In Equation 1-A, R8 to R9 are individually H and C1 to C. 18 The alkyl group can further be H or C1-C6 alkyl group;

[0017] Formula 1-B is defined as having three or more substituents C1 to C4 in R1 to R4. 10 The alkyl group is of formula 1. For example, three of the substituents in R1 to R4 are alkyl groups and the other substituent is H; or, all four substituents in R1 to R4 are alkyl groups.

[0018] In this invention, component A is preferably of formula 1-A. Studies have shown that using formula 1-A as component A, in combination with component B, can further enhance component synergy and improve the modification performance of conductive particles.

[0019] In this invention, A in Formula 1 is at least one of chlorine, bromine, iodine, tetrafluoroboric acid, hexafluorophosphate, acetic acid, bis(trifluoromethanesulfonyl)imide, nitric acid, perchloric acid, hydrogen sulfate, dihydrogen phosphate, trifluoromethanesulfonic acid, trifluoroacetic acid, and p-toluenesulfonic acid.

[0020] In this invention, component B includes compounds of formula 2-A and / or formula 2-B;

[0021] Formula 2-A is defined as having at least one substituent C1 to C7 among R5 to R7. 16 Alkyl group, with the remaining substituents being H or C1-C2. 16 Alkyl compounds of formula 2; further, in R5 to R7, one of the substituents is C4 to C5. 10 Alkyl group, with the remaining substituents being H.

[0022] In the formula 2-B, R5 to R7, at least one substituent is an amine-substituted alkyl group, and the remaining substituents are H or C1 to C2. 16 Compounds of Formula 2 containing alkyl groups (more preferably C1-C4 alkyl groups);

[0023] The amine-substituted alkyl structure is as follows: Wherein, the R 10 ~R 13 It is an alkyl group consisting of H or C1 to C6; m is an integer from 1 to 6.

[0024] Preferably, component B comprises formula 2-A and formula 2-B. Studies have shown that, based on the synergistic effect of components A and B, further using formula 2-A and formula 2-B as component B can further improve the synergistic effect of components A and B, further reduce the surface resistance of conductive particles, and improve their dispersibility and processability.

[0025] Preferably, in component B, the weight ratio of formula 2-A to formula 2-B is 0.5 to 5:1, more preferably 1 to 4:1, and even more preferably 1.5 to 3:1.

[0026] In this invention, the weight ratio of component A to component B is 0.1–8:0.1–8, more preferably 0.5–5:1, and even more preferably 1–3:1. For example, it can be 1:1, 1.5:1, 2:1, 2.5:1, or 3:1.

[0027] The present invention also provides a modified conductive nanoparticle, comprising conductive nanoparticles and the modified composition thereof composite on its surface.

[0028] In this invention, the nano-conductive particles include at least one of silver powder, copper powder, silver-coated copper powder, silver-coated aluminum powder, and silver-coated nickel powder;

[0029] In this invention, the D50 of the nano-conductive particles is less than or equal to 500 nm, preferably 50 to 200 nm.

[0030] In this invention, the modified nano-conductive particles contain a modified composition at a content of 1‰ or higher, preferably 5-10‰.

[0031] The present invention also provides a method for preparing the modified conductive nanoparticles, wherein the conductive nanoparticles are dispersed in a solvent, then mixed with the modified composition, and subsequently subjected to a solvent removal treatment to obtain the modified nanoparticles.

[0032] In this invention, the weight ratio of the nano-conductive particles to the modified composition is (0.5–10):1, such as 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. Further, the weight ratio of the nano-conductive particles to the modified composition is (0.5–4):1, more preferably 1–2:1; and even more preferably 1–1.5:1.

[0033] Preferably, the mixing and modification time is 0.5 hours or more, more preferably 1 hour or more, and further 1.5 to 6 hours.

[0034] The present invention also provides a modified conductive paste comprising the aforementioned modified nano-conductive particles;

[0035] The modified conductive paste of the present invention further comprises a carrier phase; the carrier phase comprises at least one of an organic resin, an additive, and a solvent.

[0036] The modified nano-conductive particles of the present invention have a content of 30-95 wt%, and can be further 85-93% wt%.

[0037] Beneficial effects

[0038] The modified composition provided by this invention can achieve synergy, avoid the agglomeration of nano-conductive particles, improve the dispersion performance of nano-conductive particles, and reduce their viscosity in the preparation of slurry. The prepared slurry has good dispersion performance, low viscosity, and is easy to screen print, and its conductivity can also be well exerted.

[0039] The modified conductive nanoparticles of this invention exhibit high coating efficiency, improving their dispersion stability. The slurry provided by this invention can be processed using methods such as spin coating, screen printing, micro-pen printing, and micro-jet printing. By employing a programmed temperature rise method for heat treatment, a nanoparticle with good conductivity (resistivity below 10) can be obtained. -6 High-resolution conductive patterns (on the order of Ω·cm).

[0040] In this invention, the low-temperature curing temperature of the conductive slurry based on modified nanoparticles is 80–240°C. Attached Figure Description

[0041] Figure 1 Microscopic image of the conductive slurry based on modified conductive powder prepared in Example 2 after screen printing and curing; Detailed Implementation

[0042] Component A of this invention can be a salt that is liquid below 50°C. Specifically, it can comprise two main categories: Formula 1-A and Formula 1-B. In Formula 1-A, R8 is C1 to C2. 18 The alkyl group is further exemplified by, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc. R9 is an H, C1-C6 alkyl group.

[0043] In Formula 1-B, R1 to R4 are individually methyl, ethyl, butyl, hexyl, octyl, etc.

[0044] Anions include, for example, chlorine, bromine, tetrafluoroboric acid, hexafluorophosphate, and bis(trifluoromethanesulfonyl)imide.

[0045] Furthermore, Formula 1-A may specifically include the following components:

[0046] At least one of them.

[0047] The components that can be listed in Formula 1-B include, for example, wait.

[0048] In this invention, Formula 2-A is, for example, R-NH2, where R is a C4 to C12 n-alkyl group.

[0049] Equation 2-B can be further, for example, as follows: Wherein, R10 to R13 are individually H or C1 to C3 alkyl groups; m is an integer of 2 or more, and further is 2 to 6.

[0050] This invention also provides a method for preparing modified nano-conductive powder, comprising the following steps:

[0051] Step 1: Pretreatment of nanoparticles: Wash the nano-conductive powder with a dispersion liquid to remove excess impurities from the surface of the nano-conductive powder.

[0052] Step 2: Disperse the cleaned nano-conductive powder from Step 1 with a dispersion liquid to obtain a mixed liquid; add the mixed liquid to the modified liquid for a modification reaction; after the reaction, filter, wash, and dry to obtain modified nano-powder.

[0053] In step (1), the pretreatment temperature is 10-40℃, preferably 25-35℃;

[0054] The dispersion is an alcohol solvent;

[0055] Furthermore, the dispersion is selected from at least one of methanol, ethanol, n-propanol, isopropanol, and butanol; preferably, the solvent is ethanol.

[0056] In step (2), the dispersion treatment can be magnetic stirring or ultrasonic dispersion; the dispersion treatment time is 5 min to 1 h.

[0057] In step (2), the weight ratio of conductive nanoparticles to the modified liquid is (0.5–10):1, such as 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. Preferably, the weight ratio is 0.5–4:1.

[0058] The temperature of the modification reaction is 15℃~80℃; preferably, the temperature of the modification reaction is 30℃~50℃.

[0059] The modification reaction time is 0.5h to 12h, preferably 1.5h to 6h.

[0060] The present invention also provides a conductive slurry based on modified nano-conductive powder, wherein the nano-conductive particles are used as the functional phase, accounting for 30-95% by weight, and the remainder is a carrier phase.

[0061] The carrier phase comprises one or more of organic resin, additives, and solvents. The organic resin comprises one or more of PVB resin (polyvinyl butyral), epoxy resin, phenolic resin, and polyurethane. The additives are at least one of thixotropic agents, leveling agents, dispersants, and coupling agents. The organic solvent is at least one of diethylene glycol butyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether acetate, divalent ester, ethyl acetate, butyl acetate, naphtha, propylene glycol methyl ether acetate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, tributyl citrate, dibutyl phthalate, butyl benzyl phthalate, butyl stearate, oleic acid, butyl oleate, and terpineol. More preferably, when the carrier phase comprises organic resin and solvent, or comprises organic resin, additives, and solvents, based on the total mass of the carrier phase, the organic resin comprises 5%–30% (more preferably 8%–15%), the additives 0%–5%, and the solvent 65%–90% by mass fraction.

[0062] This invention also provides a method for preparing a conductive slurry based on modified nano-conductive powder, the steps of which are as follows:

[0063] The modified nano-conductive powder was mixed and stirred with the carrier phase. After being evenly dispersed, the resulting slurry was ground to obtain a conductive slurry based on the modified nano-powder.

[0064] In this invention, the composition and proportion of the conductive paste can be conventional. The compositions and proportions listed in the following examples are merely simple test examples and do not involve necessary limitations on the implementation of the technical solution.

[0065] The specific plan is as follows:

[0066] Example 1

[0067] (1) 20g of silver powder with a particle size of 120nm was washed twice with ethanol and then dispersed in 100mL of anhydrous methanol to obtain a mixture. The mixture was added to the modification solution, wherein the weight ratio of silver powder to modification solution was 2:1. The mixture was stirred at 25℃ for 2h. After the reaction, it was filtered, washed with ethanol, and air-dried at 25℃ to obtain modified conductive powder.

[0068] The modified solution includes 5g of component A (formula 1-A-1), 5g of component B (which contains formula 2-A-1 and formula 2-B-1 in a weight ratio of 3:2, wherein formula 2-A-1 is a compound with R5, R6 being H, and R7 being n-octyl), and formula 2-B-1 is...

[0069] (2) Mix 8g of modified conductive powder with the carrier phase, which includes 0.075g of PVB resin and 0.845g of divalent ester. After uniform dispersion, the resulting slurry is ground 6 times with a three-roll mill to obtain a conductive slurry based on the modified conductive powder.

[0070] Example 2

[0071] The procedure is essentially the same as in Example 1, except that the amount of modifying solution is changed so that the weight ratio of the modifying solution to silver powder is 1:1. Other operations and parameters are the same as in Example 1.

[0072] Example 3

[0073] The procedure is essentially the same as in Example 2, except that the modification time is changed to 1 hour. Other operations and parameters are the same as in Example 2.

[0074] Example 4

[0075] This is essentially the same as Example 2, except that component A is changed to Formula 1-B-2. Other operations and parameters are the same as in Example 2.

[0076] Example 5

[0077] The results are basically the same as in Example 2, except that: in the modified liquid, component B is a single formula 2-A-1; and the amount of component B and other parameters are the same as in Example 2.

[0078] Example 6

[0079] It is basically the same as Example 2, except that: component B is a single formula 2-B-1, and the amount of component B and other parameters are the same as in Example 2.

[0080] Example 7

[0081] The process is basically the same as in Example 2, except that the weight ratio of Formula 2-A-1 to Formula 2-B-1 in Component B in the modified liquid is 0.5:1, and the amount of Component B and other operations and parameters are the same as in Example 2.

[0082] Example 8

[0083] (1) 20g of silver powder with a particle size of 120nm was washed twice with ethanol and then dispersed in 100mL of anhydrous methanol to obtain a mixture. The mixture was added to the modification solution, wherein the weight ratio of silver powder to modification solution was 1:1. The mixture was stirred at 25℃ for 2h. After the reaction, it was filtered, washed with ethanol, and air-dried at 25℃ to obtain modified conductive powder.

[0084] The modified liquid includes 15g of component A (formula 1-A-3), 5g of component B (which contains formula 2-A-2 and formula 2-B-2 in a weight ratio of 3:2, wherein formula 2-A-2 is a compound with R5 and R6 being H and R7 being n-butyl), and formula 2-B-2 is...

[0085] (2) Mix 8g of modified conductive powder with the carrier phase, which includes 0.1g of PVB resin and 0.9g of divalent ester. After uniform dispersion, the resulting slurry is ground 6 times with a three-roll mill to obtain a conductive slurry based on the modified conductive powder.

[0086] Example 9

[0087] The procedure is essentially the same as in Example 2, except that the conductive nanoparticles are silver-coated aluminum powder with a particle size of 200 nm. Other operations and parameters are the same as in Example 2.

[0088] Comparative Example 1

[0089] It is basically the same as Example 2, except that the modified liquid is only Formula 2-A-1, and the total amount of modified liquid and other parameters are the same as in Example 2.

[0090] Comparative Example 2

[0091] It is basically the same as Example 2, except that the modified liquid is only Formula 2-B-1, and the total amount of modified liquid and other parameters are the same as in Example 2.

[0092] Comparative Example 3

[0093] It is basically the same as Example 2, except that the modified liquid is only of Formula 1-A-1, and the total amount of modified liquid and other parameters are the same as in Example 2.

[0094] Comparative Example 4

[0095] The process is basically the same as in Example 2, except that step 1 is omitted. Instead, 8g of nano-silver powder is directly weighed and mixed with the carrier to prepare the conductive paste. Other operations and parameters are the same as in Example 2.

[0096] test

[0097] The conductive pastes based on modified conductive powder prepared in Examples 1-9 and Comparative Examples 1-4 were screen-printed onto glass substrates with a printing length of 100 mm and a width of 1 mm. After curing at 200°C for 15 minutes, their line resistance was tested, and the resistivity and viscosity of the prepared conductive pastes based on modified conductive powder were also tested. The results are shown in Table 1.

[0098] In each case, 0.5g of the modified powder obtained in step 1 was placed in a muffle furnace at 600℃ and calcined for 2 hours. The mass of the powder sample before and after calcination was weighed, and the coating rate of the modified powder was calculated.

[0099] Table 1. Comparison of test results of slurries prepared in Examples 1-9 and Comparative Examples 1-4

[0100]

[0101] As can be seen from the test data in Table 1, when the weight ratio of conductive powder to modifying liquid is 1:1 and the modification time is 2 hours, the coating effect is better, with an actual coating rate of 9.37‰. The modifying liquid, which is a mixture of component A and component B, achieves a good coating rate when modifying the nano-conductive powder. The synergistic modification effect is best when component A, component B of formula 2-A, and component B of formula 2-B are combined, resulting in a slurry with a minimum coating density of 4.95 × 10⁻⁶. -6 The volume resistivity is Ω·cm, the linear resistivity is 0.33Ω, and the slurry viscosity is moderate. Figure 1 As can be seen, the conductive paste based on modified conductive nanoparticles in Example 2 has high wettability. Due to its moderate viscosity, the conductive paste based on modified nanoparticles has good rheological properties for screen printing, good density and smoothness after curing, which further improves its conductivity.

Claims

1. A modified composition for modifying nano-conductive particles, characterized in that, It comprises component A and component B; wherein component A comprises at least one compound of formula 1; component B comprises at least one compound of formula 2; wherein the melting point of component A is below 50°C; and the boiling point of component B is below 180°C. R1 to R4 are individually C1 to C 18 The alkyl group, and / or two or more substituents from R1 to R4, cyclize to form a five-membered or more N-containing heterocycle; wherein A is an anion, and n is the charge number of the anion; At least one substituent in R5 to R7 is C1 to C2. 18 The alkyl group is a substituent of H, C1-C6 alkyl groups, or amine-substituted alkyl groups.

2. The modified composition for modifying nano-conductive particles as described in claim 1, characterized in that, Formula 1 includes compounds of Formula 1-A and / or Formula 1-B; In Equation 1-A, R8 to R9 are individually H and C1 to C. 18 Alkyl groups; Formula 1-B is defined as having three or more substituents C1 to C4 in R1 to R4. 10 Alkyl group of formula 1.

3. The modified composition for modifying nano-conductive particles as described in claim 1, characterized in that, The A is at least one of chlorine, bromine, iodine, tetrafluoroboric acid, hexafluorophosphate, acetic acid, bis(trifluoromethanesulfonyl)imide, nitric acid, perchloric acid, hydrogen sulfate, dihydrogen phosphate, trifluoromethanesulfonic acid, trifluoroacetic acid, and p-toluenesulfonic acid.

4. The modified composition for modifying nano-conductive particles as described in claim 1, characterized in that, Component B includes compounds of formula 2-A and / or formula 2-B; Formula 2-A is defined as having at least one substituent C1 to C7 among R5 to R7. 16 Alkyl group, with the remaining substituents being H or C1-C2. 16 Alkyl compounds of formula 2; In the formula 2-B, R5 to R7, at least one substituent is an amine-substituted alkyl group, and the remaining substituents are H or C1 to C2. 16 Alkyl compounds of formula 2; The amine-substituted alkyl structure is as follows: Wherein, the R 10 ~R 13 It is an alkyl group consisting of H or C1 to C6; m is an integer from 1 to 6.

5. The modified composition for modifying nano-conductive particles as described in claim 4, characterized in that, Component B comprises formula 2-A and formula 2-B; Preferably, in component B, the weight ratio of formula 2-A to formula 2-B is 0.5 to 5:

1.

6. The modified composition for modifying nano-conductive particles according to any one of claims 1 to 5, characterized in that, The weight ratio of component A to component B is 0.1–8:0.1–8.

7. A modified conductive nanoparticle, characterized in that, Including conductive nanoparticles and the modified composition according to any one of claims 1 to 6 composite thereon.

8. The modified conductive nanoparticles as described in claim 7, characterized in that, The aforementioned conductive nanoparticles include at least one of silver powder, copper powder, silver-coated copper powder, silver-coated aluminum powder, and silver-coated nickel powder. Preferably, the D50 of the nano-conductive particles is less than or equal to 500 nm, and more preferably 50 to 200 nm. Preferably, the modified composition is present in the modified conductive nanoparticles at a content of 1‰ or higher, and more preferably 5-10‰.

9. A method for preparing the modified conductive nanoparticles according to claim 7 or 8, characterized in that, The conductive nanoparticles are dispersed in a solvent, then mixed with the modified composition for modification, and subsequently subjected to solvent removal treatment to obtain the final product. Preferably, the weight ratio of the nano-conductive particles to the modified composition is (0.5-10):1; Preferably, the mixing and modification time is 0.5 hours or more, more preferably 1 hour or more, and further 1.5 to 6 hours.

10. A modified conductive paste, characterized in that, Contains the modified conductive nanoparticles as described in claim 7 or 8; Preferably, it further comprises a support phase; said support phase comprises at least one of an organic resin, an additive, and a solvent; Preferably, the content of the modified conductive nanoparticles is 30-95 wt%.

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