A perfluorodiacyl peroxide represented by the following formula (1):
(C.sub.5F.sub.11COO).sub.2   (1).
Also disclosed is a solution containing the perfluorodiacyl peroxide, a polymerization initiator containing the perfluorodiacyl peroxide, a method for producing a polymer which includes polymerizing a radically polymerizable monomer with the perfluorodiacyl peroxide, and a perfluoroacyl chloride represent by the following formula (2):
C.sub.5F.sub.11COCl (2).

A perfluorodiacyl peroxide represented by the following formula (1):
(C.sub.5F.sub.11COO).sub.2   (1).
Also disclosed is a solution containing the perfluorodiacyl peroxide, a polymerization initiator containing the perfluorodiacyl peroxide, a method for producing a polymer which includes polymerizing a radically polymerizable monomer with the perfluorodiacyl peroxide, and a perfluoroacyl chloride represent by the following formula (2):
C.sub.5F.sub.11COCl (2).

The invention relates to an organic peroxide emulsion comprising at least one organic peroxide comprising di-sec-butyl peroxydicarbonate, at least one emulsifier, at least one antifreeze, and water; said emulsion being free of methanol and ethanol.

The invention also relates to a process for preparing such an emulsion, to the use of such an emulsion for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, and also to a halogenated vinyl polymer obtained by using such an emulsion.

The invention relates to an organic peroxide emulsion comprising at least one organic peroxide comprising di-sec-butyl peroxydicarbonate, at least one emulsifier, at least one antifreeze, and water; said emulsion being free of methanol and ethanol.

The invention also relates to a process for preparing such an emulsion, to the use of such an emulsion for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, and also to a halogenated vinyl polymer obtained by using such an emulsion.

Process for the production of a diacyl peroxide involving the reaction of an anhydride with an aldehyde and oxygen, removal of the formed carboxylic acid, production of an anhydride from said carboxylic acid, and recycling of the anhydride within the process.

Process for the production of a diacyl peroxide involving the reaction of an anhydride with an aldehyde and oxygen, removal of the formed carboxylic acid, production of an anhydride from said carboxylic acid, and recycling of the anhydride within the process.

Process for the production of a diacyl peroxide involving the reaction of an anhydride with a peroxyacid, removal of the formed carboxylic acid, production of an anhydride from said carboxylic acid, and recycling of the anhydride within the process.

Process for the production of a diacyl peroxide involving the reaction of an anhydride with a peroxyacid, removal of the formed carboxylic acid, production of an anhydride from said carboxylic acid, and recycling of the anhydride within the process.

A process for the preparation of perhaloacyl peroxides from perhaloacyl halides which is performed in the presence of a hydrofluoroether as the solvent.

A process for the preparation of perhaloacyl peroxides from perhaloacyl halides which is performed in the presence of a hydrofluoroether as the solvent.