Abstract: Selective removal of primary amines from technical grade diphenylamine by contacting a solvent solution of said diphenylamine with a cationic exchange resin having sulfonic acid group functionality in the presence of up to about 3 percent water.

Abstract: A method is provided for stabilizing alkylenebisdithiocarbamates, such as 1,2-ethylenebisdithiocarbamates (EBDC), by mixing the EBDC in the presence of water with a hydroxymethane sulfinate (HMS) which degrades to formaldehyde to reduce the content of ethylenethiourea (ETU) in the EBDC. The HMS and sulfate by-product from the formaldehyde formation also act as reducing agents to inhibit further ETU formation by oxidative decomposition of EBDC. The hydroxymethane sulfinate is preferably added in an amount of about 0.1 to 5 weight percent based upon the EBDC, and the aqueous reaction mixture is then preferably dried under vacuum. Co-polymerization agents, such as hydroquinone or melamine, may also be added to further reduce and inhibit ETU content and formation.

Abstract: A method is provided for stabilizing alkylenebisdithiocarbamates (EBDC) by mixing the EBDC with chloralhydrate to reduce the content of alkylenethiourea (ETU) in the EBDC. The chloralhydrate is preferably added in an amount of about 0.1 to 5 weight percent based upon the EBDC. The preferably liquid (e.g., aqueous or alcoholic) reaction mixture is then preferably dried under vacuum. The stabilized EBDC product contains chloralhydrate, mono- and/or bis-trichloroethylol-alkylenethioureas, and less than about 0.015 weight percent ETU.

Abstract: A method is provided for stabilizing alkylenebisdithiocarbamates, such as 1,2-ethylenebisdithiocarbamates, (EBDC) by mixing the EBDC with formaldehyde or formaldehyde releasing agents (donor) and a co-polymerization agent which forces the polymerization reaction of formaldehyde and ethylenethioureas toward completion to reduce and stabilize the content of and inhibit the formation of ethylenethiourea (ETU) in the EBDC. Paraformaldehyde as donor is preferably added in an amount of about 0.1 to 2 weight percent based upon the EBDC, together with a co-polymerization agent such as melamine or hydroquinone. The stabilized EBDC product contains aldehyde, co-polymerization agent, mono- and /or dimethylolethylenethioureas and polymerization products thereof, and less than about 0.015 weight percent ETU per se.