US 12,354,764 B2
Silver powder, method for producing same, and conductive resin composition
Kentaro Ochi, Takehara (JP)
Assigned to MITSUI MINING & SMELTING CO., LTD., (JP)
Appl. No. 18/022,883
Filed by Mitsui Mining & Smelting Co., Ltd., Tokyo (JP)
PCT Filed Sep. 15, 2021, PCT No. PCT/JP2021/033848
§ 371(c)(1), (2) Date Feb. 23, 2023,
PCT Pub. No. WO2022/075021, PCT Pub. Date Apr. 14, 2022.
Claims priority of application No. 2020-168775 (JP), filed on Oct. 5, 2020.
Prior Publication US 2023/0360820 A1, Nov. 9, 2023
Int. Cl. H01B 1/22 (2006.01); B22F 1/054 (2022.01); B22F 1/10 (2022.01); C08K 3/08 (2006.01); C25C 1/20 (2006.01)
CPC H01B 1/22 (2013.01) [B22F 1/0553 (2022.01); B22F 1/056 (2022.01); B22F 1/10 (2022.01); C08K 3/08 (2013.01); C25C 1/20 (2013.01); B22F 2301/255 (2013.01); B22F 2304/054 (2013.01); B22F 2999/00 (2013.01); C08K 2003/0806 (2013.01); C08K 2201/001 (2013.01); C08K 2201/003 (2013.01); C08K 2201/011 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A silver powder comprising silver particles including dendrite silver particles, each of the dendrite silver particles being in a dendrite shape having only a single trunk and a plurality of branches branching from the single trunk,
wherein a thickness of the single trunk is from 10 to 280 nm, and a length of the single trunk is from 0.5 to 10.0 μm,
the number of the plurality of branches per length of the single trunk is from 6 to 30 branches/μm,
the plurality of branches directly branch from the single trunk, and
the percentage by number of the dendrite silver particles in the whole of the silver particles is 50 N % or more,
the silver powder has a shrinkage rate of 0.3% or more, and the shrinkage rate is defined under the following conditions:
0.5 g of the silver powder is placed in a measurement fitting, to which a first load is applied, to obtain a sample;
the sample is disposed on a thermo-mechanical analyzer, and a temperature of the sample is increased under a second load from 25° C. to 800° C. at a rate of 10° C./min in a mixed atmosphere of nitrogen and hydrogen; and
an absolute value of a negative coefficient of expansion at 150° C. is defined as the shrinkage rate, and
the silver powder has a crystallite size of from 10 to 49 nm.