US 12,318,838 B2
Dispersion medium for metal particle sintering, and electroconductive paste
Takanori Kobatake, Tokyo (JP); Katsuaki Suganuma, Suita (JP); and Shuhei Takata, Suita (JP)
Assigned to DAICEL CORPORATION, Osaka (JP)
Appl. No. 17/799,961
Filed by DAICEL CORPORATION, Osaka (JP)
PCT Filed Feb. 2, 2021, PCT No. PCT/JP2021/003617
§ 371(c)(1), (2) Date Aug. 16, 2022,
PCT Pub. No. WO2021/166627, PCT Pub. Date Aug. 26, 2021.
Claims priority of application No. 2020-025765 (JP), filed on Feb. 19, 2020.
Prior Publication US 2023/0077759 A1, Mar. 16, 2023
Int. Cl. B22F 1/00 (2022.01); H01B 1/22 (2006.01)
CPC B22F 1/00 (2013.01) [H01B 1/22 (2013.01)] 18 Claims
 
1. A dispersion medium for metal particle sintering, the metal particle being at least one type selected from the group consisting of copper particles, copper alloy particles, and copper oxide particles,
the dispersion medium comprising formic acid and a basic compound,
wherein the basic compound is a nitrogen-containing compound represented by the following Formula (1)

OG Complex Work Unit Chemistry
where Ra to Rc are the same or different and each represent a hydrogen atom or a hydrocarbon group that may have a substituent, provided that Ra to Rc are not hydrogen atoms at the same time;
at least one of Ra to Rc satisfies at least one of the following (i) to (iii):
(i) at least one selected from the group consisting of a linear or branched alkyl group having 3 to 12 carbons, a linear or branched alkenyl group, a linear or branched alkynyl group, a linear or branched alkylidene group, a cycloalkyl group and a cycloalkenyl group;
(ii) an aromatic hydrocarbon group having 6 to 18 carbons; and
(iii) at least one substituted hydrocarbon group selected from the group consisting of an amino group, a N-substituted amino group, a N,N-substituted amino group, an imino group, a N-substituted imino group and a hydroxyl group;
the double line including a dashed line represents a single bond or a double bond, with Rc being absent in the case of a double bond; and
any two of Ra to Rc may bond with each other and form a ring together with the adjacent nitrogen atom, and
a molar ratio (basic group/formic acid) of basic groups included in the basic compound to formic acid being from 0.50 to 1.20, and the basic group is a nitrogen-containing group.