Electroconductive paste

Patent metadata

Field	Value
Publication number	US-9796866-B2
Application number	US-201515124442-A
Country	US
Kind code	B2
Filing date	Mar 16, 2015
Priority date	Mar 20, 2014
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

The present invention provides a conductive paste that has excellent printability, that can provide a printed electrode with a smooth surface, and that is excellent in storage stability. The present invention relates to a conductive paste used for formation of an electrode of a multilayer ceramic capacitor, the conductive paste including: a polyvinyl acetal resin that contains a carboxylic acid-modified polyvinyl acetal resin; an organic solvent; and a conductive powder, the polyvinyl acetal resin having an average degree of polymerization of 200 to 800, an carboxyl group content of 0.05 to 1 mol %, a hydroxy group content of 16 to 24 mol %, an acetyl group content of 0.1 to 3 mol %, and an acetoacetal group content of not more than 25 mol %, the carboxylic acid-modified polyvinyl acetal resin having at least one of a structural unit that has a carboxyl group represented by the formula (1-1) and a structural unit that has a carboxyl group represented by the formula (1-2):

in the formula (1-1), R 1 and R 2 each independently representing a C0-C10 alkylene group, X 1 and X 2 each independently representing a hydrogen atom, a metal atom, or a methyl group, in the formula (1-2), R 3 , R 4 , and R 5 each independently representing a hydrogen atom or a C1-C10 alkyl group, R 6 representing a C0-C10 alkylene group, X 3 representing a hydrogen atom, a metal atom, or a methyl group.

First claim

The invention claimed is:

1. A conductive paste used for formation of an electrode of a multilayer ceramic capacitor, the conductive paste comprising:
a polyvinyl acetal resin that contains a carboxylic acid-modified polyvinyl acetal resin;
an organic solvent; and
a conductive powder,
the polyvinyl acetal resin having an average degree of polymerization of 200 to 800, a carboxyl group content of 0.05 to 1 mol %, a hydroxy group content of 16 to 24 mol %, an acetyl group content of 0.1 to 3 mol %, and an acetoacetal group content of not more than 25 mol %,
the carboxylic acid-modified polyvinyl acetal resin having at least one of a structural unit that has a carboxyl group represented by the formula (1-1) and a structural unit that has a carboxyl group represented by the formula (1-2):

in the formula (1-1), R 1 and R 2 each independently represent a C0-C10 alkylene group, X 1 and X 2 each independently represent a hydrogen atom, a metal atom, or a methyl group, in the formula (1-2), R 3 , R 4 , and R 5 each independently represent a hydrogen atom or a C1-C10 alkyl group, R 6 represents a C0-C10 alkylene group, X 3 represents a hydrogen atom, a metal atom, or a methyl group,

wherein C0 represents carbons adjacent to R 1 ,R 2 , or R 6 being directly bonded to each other,
wherein the polyvinyl acetal resin has a ratio of the acetyl group content to the hydroxy group content of 0.07 to 0.15.

2. The conductive paste according to claim 1 ,
wherein the conductive powder comprises nickel.

3. The conductive paste according to claim 1 , further comprising a ceramic powder.

4. The conductive paste according to claim 1 ,
wherein the organic solvent has a solubility parameter of 8.0 to 11.0 (cal/cm 3 ) 0.5 .

5. The conductive paste according to claim 1 ,
wherein the polyvinyl acetal resin has a sodium ion content of less than 50 ppm.

6. A multilayer ceramic capacitor produced using the conductive paste according to claim 1 .

Assignees

• Sekisui Chemical Co Ltd

Inventors

• Kobayashi Hiroko
• Yamauchi Kenji
• Moriguchi Shintaro
• Miyai Jiro

Classifications

• H01B1/22 Primary

  the conductive material comprising metals or alloys · CPC title

• C08K2003/0862

  Nickel · CPC title

• H01G4/30

  Stacked capacitors (H01G4/33 takes precedence) · CPC title

• C09D131/04

  Homopolymers or copolymers of vinyl acetate · CPC title

• H01G4/008

  Selection of materials · CPC title