Dielectric fluid compositions for enhanced thermal management

Patent metadata

Field	Value
Publication number	US-9416089-B2
Application number	US-201214344937-A
Country	US
Kind code	B2
Filing date	Sep 26, 2012
Priority date	Sep 30, 2011
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A dielectric fluid composition for electrical apparatus comprises a functionalized 12-hydroxy stearic acid having desirable properties including a pour point less than −30° C. and a fire point greater than 250° C. It may be prepared by a process wherein 12-hydroxy methyl stearate is transesterified by reaction with a C3-C20 alcohol to form an alkyl-12-hydroxy stearate, followed by esterification thereof with a linear or branched C4-C20 carboxylic acid. This acid may be a free acid chloride, a fatty acid, a carboxylic acid anhydride, or combination thereof. The resulting functionalized 12-hydroxy stearic acid exhibits improved thermoxidative capability, low temperature flowability, and increased fire point.

First claim

What is claimed is:

1. A process for preparing a dielectric fluid composition comprising (a) reacting 12-hydroxy methyl stearate and a linear or branched C3 to C20 alcohol under conditions suitable to form an alkyl-12-hydroxy stearate; and (b) reacting the alkyl-12-hydroxy stearate and a carboxylic acid selected from the group consisting of linear and branched C4-C20 free acid chlorides, fatty acids, carboxylic acid anhydrides, and combinations thereof, under conditions suitable to form a functionalized 12-hydroxy stearic acid.

2. The process of claim 1 , wherein the alcohol is selected from the group consisting of C8 to C10 alcohols.

3. The process of claim 1 , wherein the carboxylic acid is selected from linear and branched C8 to C10 fatty acids and carboxylic acid anhydrides.

4. The process of claim 1 , wherein the carboxylic acid is a linear or branched C8 to C10 free acid chloride.

Assignees

• Dow Global Technologies Llc

Inventors

• Han Suh Joon
• Zinkweg Dirk B
• Lysenko Zenon

Classifications

• H01B3/20 Primary

  liquids, e.g. oils (silicone oils H01B3/46) · CPC title

• C07C51/367

  by introduction of functional groups containing oxygen only in singly bound form · CPC title

• H01B3/24

  containing halogen in the molecules, e.g. halogenated oils · CPC title

• C07C59/01 Primary

  Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups · CPC title

• C07C51/377

  by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups {(C07C51/36 - C07C51/373 take precedence)} · CPC title