Kenichi Sanechika

Novel refrigeration lubricants for use with HFC refrigerants

A series of fluorinated alkyl aryl ethers composed of hydrocarbon components, fluorinated alkyl groups and ether linkage groups were evaluated as refrigeration lubricants for use with hydrofluorocarbon (HFC) refrigerants. The novel structure of these lubricants eliminates the problems of poor stability and high moisture absorption that are associated with conventional refrigeration lubricants for use with HFC refrigerants, such as polyalkylene glycol or polyol ester, which have a polar structure. The fluorinated alkyl aryl ethers show high miscibility with HFC refrigerants, high stability, excellent lubricity, and low moisture absorption. These characteristics make fluorinated alkyl aryl ethers well suited to serve as refrigeration lubricants for use with HFC refrigerants.

Thermal and oxidative stability of fluorinated alkyl aryl ethers

Abstract A series of compounds composed of hydrocarbon aryl components and fluorinated alkyl components joined by ether linkages were developed for evaluation as high performance lubricants. Thermal and oxidative stability of these compounds were evaluated. The basic molecular structure was shown to be highly durable against high temperature, even in air, which is an indispensable property if it is to be suitable as base stock for high performance lubricants. However, thermal and oxidative stability decreased when hydrogen atoms were present on carbons adjacent to benzene rings, especially in the case of the carbon at the center of the compound, which is adjacent to two benzene rings.

Unique bioconcentration characteristics of new aryl fluoroalkyl ethers in common carp (Cyprinus carpio)

The bioconcentration factors (BCFs) of seven new aryl fluoroalkyl ethers--four bis-4-tetrafluoroethoxyphenyl-type (bis-type) compounds and three mono-4-tetrafluoroethoxyphenyl-type (mono-type) compounds--were obtained by bioconcentration tests using common carp. The BCFs of 4 of the 7 ethers were higher than 5000, indicating their high bioconcentration potential. The bioconcentration characteristics of the bis-type compounds were different from those of the mono-type compounds and non-fluoro diphenylmethanes with a similar skeleton structure to the bis-type compounds, in taking longer to reach a plateau and having a slower elimination rate and in their distribution patterns in the fish body. The BCF of 1 bis-type compound was much higher than the value predicted by an accepted correlation equation between BCF and P(ow). In addition, the logP(ow) of the bis-type compounds calculated by commercially available computer software was remarkably different from that measured.

Lubricity of fluorinated alkyl aryl ethers

Abstract A series of fluorinated alkyl aryl ethers, composed of hydrocarbon components, fluorinated alkyl groups, and ether linkage groups, were evaluated through a variety of tests to investigate lubricating properties. The basic molecular structure with tetrafluoroethoxyphenyl groups were shown to have excellent lubricities. However, ortho -position substituents to ether linkage groups diminished extreme-pressure properties. Excellent lubricities were suggested to be due to strong coordination of ether oxygen atoms to metal surfaces, and formation of iron fluorides on the metal wear surfaces.

New type lubricant for refrigerator using HFC refrigerants

New type of refrigeration lubricant for hydrofluorocarbon (HFC) refrigerants has been developed. This lubricant has the hybrid structure composed of the hydrocarbon residue and the fluorine containing residue. Because of its novel structure, this lubricant is free from the defects of the candidate refrigeration lubricants with polar structure, such as polyalkylene glycol and polyol ester. This lubricant shows the high miscibility with various HFC refrigerants such as HFC-134a and HFC-32, the high stability, the excellent lubricity and the low moisture absorption. These characteristics will afford the new generation of the refrigeration lubricant for use with any kinds of HFC refrigerant.