Compact drying method

Patent metadata

Field	Value
Publication number	US-10183893-B2
Application number	US-201514861092-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Mar 26, 2013
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A compact is formed by introducing a slurry containing a ceramic powder or a metal powder, a binder and a solvent into a compaction die, and compacting the slurry in the compaction die. The compact embedded in the compaction die is immersed in an alternative CFC (liquid) (FIG. 4 A). The solvent contained in the compact is gradually replaced with the alternative CFC. In the course of this process, the compact separates naturally from the compaction die (releasing is achieved) without receiving an external force. Subsequently, the compact is taken out of the alternative CFC (liquid). The alternative CFC has a boiling point as low as 95° C. at 1 atmospheric pressure. Accordingly, the alternative CFC contained in the compact will volatilize at high speed, thus being removed. Consequently, the compact can be dried in a relatively short time without being heated.

First claim

What is claimed is:

1. A compact drying method for drying a compact produced by compacting a slurry containing a ceramic powder or a metal powder, a binder, and a solvent capable of dissolving the binder, the method including:
a first step of replacing the solvent contained in the compact with a liquid that has a boiling point of 95° C. or less at 1 atmospheric pressure, which is compatible with the solvent and does not dissolve the binder, by immersing the compact in the liquid under normal pressure while a surface of the compact is partially exposed outside in a state where the compact is embedded in a compaction die for compacting the slurry, and allowing spontaneous separation of the compact from the compaction die while the compact is immersed in the liquid, the compaction die being composed of a material having a density that does not allow penetration of the liquid to the inside; and
a second step of taking the compact out of the liquid after the first step and removing the liquid from the compact by volatilization.

2. The compact drying method according to claim 1 ,
wherein the liquid is one of hydrofluorocarbon, hydrofluoroether and hydrochlorofluorocarbon.

3. The compact drying method according to claim 1 ,
wherein the solvent has a boiling point of 120° C. or more at 1 atmospheric pressure.

4. The compact drying method according to claim 1 ,
wherein the binder is a urethane precursor that produces a urethane resin by a chemical reaction.

5. The compact drying method according to claim 1 ,
wherein the second step is performed under a pressure which is lower than normal pressure.

6. The compact drying method according to claim 1 ,
wherein the solvent is dibasic acid ester and the liquid is hydrofluoroether.

Assignees

• Ngk Insulators Ltd

Inventors

• Fuji Yusuke
• Yoshioka Kunihiko

Classifications

• C04B2235/606

  Drying · CPC title

• C04B2235/604

  Pressing at temperatures other than sintering temperatures · CPC title

• B01D12/00

  Displacing liquid, e.g. from wet solids or from dispersions of liquids or from solids in liquids, by means of another liquid · CPC title

• C04B35/638 Primary

  Removal thereof · CPC title

• F26B2210/02

  Ceramic articles or ceramic semi-finished articles · CPC title