Method for preparing an ester and binder system

Patent metadata

Field	Value
Publication number	US-9637418-B2
Application number	US-99887509-A
Country	US
Kind code	B2
Filing date	Nov 25, 2009
Priority date	Dec 15, 2008
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

In a method for preparing an ester from an hydroxybenzoic acid and a fatty alcohol for use in a binder system for powder injection molding, transesterification of an ester of the hydroxybenzoic acid and a low alcohol using the fatty alcohol is carried out, the fatty alcohol and the ester of the hydroxybenzoic acid and the low alcohol forming a reaction mixture and being used in an essentially equimolar ratio. The transesterification is carried out at a temperature at which the ester of the hydroxybenzoic acid and the low alcohol and the fatty alcohol are present as a homogeneous melt. The binder system for a powder injection molding contains 80 to 98 wt. % of a metal powder and/or a ceramic powder and 1 to 19 wt. % of a polymeric binder component, and 1 to 19 wt. % of at least one ester prepared by the transesterification.

First claim

What is claimed is:

1. A method for preparing an ester, comprising:
forming the ester from an hydroxybenzoic acid and a fatty alcohol by transesterification of an ester of the hydroxybenzoic acid and a low alcohol using the fatty alcohol,
wherein the fatty alcohol is a mixture of two or more 1-alkanols,
wherein each of the two or more 1-alkanols has a carbon number of at least 16,
wherein the carbon numbers of at least two of the two or more 1-alkanols differ,
wherein the fatty alcohol and the ester of the hydroxybenzoic acid and the low alcohol are used in an essentially equimolar ratio and form a reaction mixture, and
wherein the transesterification is carried out at a temperature below 195° C. at which the ester of the hydroxybenzoic acid and the low alcohol and the fatty alcohol are present as a homogeneous melt.

2. The method as recited in claim 1 , wherein each of the two or more 1-alkanols is selected from the group consisting of 1-docosanol, 1-eicosanol, 1-octadecanol.

3. The method as recited in claim 1 , wherein the mixture of two or more 1-alkanols contains at least 90 wt. %, in relation to the mass the ester, of a specific 1-alkanol.

4. The method as recited in claim 2 , wherein the low alcohol which split off during the transesterification is removed from the reaction mixture by distillation.

5. The method as recited in claim 2 , wherein the transesterification is carried out in the presence of a catalyst.

6. The method as recited in claim 5 , wherein the catalyst is an organometallic tin-containing compound.

7. The method as recited in claim 6 , wherein the organometallic tin-containing compound is selected from the group consisting of dibutyl-tin oxide, dibutyl-tin dilaurate or butyl-tin oxide hydroxide.

8. The method as recited in claim 6 , wherein the quantity of catalyst used, in relation to the mass of the reaction mixture, amounts to 0.1 to 1 wt. %.

9. The method as recited in claim 6 , wherein a protective gas stream is led through the reaction mixture.

10. The method as recited in claim 6 , wherein a reducing agent is added to the reaction mixture.

Assignees

• Aichele Wilfried
• Rager Jochen
• Czerwinski Klaus
• Grath Eberhard
• Arnold Josef
• Weisser Eva
• Bosch Gmbh Robert

Inventors

• Aichele Wilfried
• Rager Jochen
• Czerwinski Klaus
• Grath Eberhard
• Arnold Josef
• Weisser Eva

Classifications

• B22F1/103

  containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent · CPC title

• C08K5/134

  Phenols containing ester groups · CPC title

• C04B35/465

  based on alkaline earth metal titanates · CPC title

• C04B35/632

  Organic additives · CPC title

• C07C67/03

  by reacting an ester group with a hydroxy group · CPC title