Stabilized dibenzoyl peroxides polymer initiator compositions

Abstract

A polymer initiator composition and method for its production are provided, the composition being non-separating and stable and including a substantial amount of a dibenzoyl peroxide and an effective amount of a hydrophobic alkyl group-containing silica in an amount sufficient to prevent the composition from physically separating into its components.

What is claimed is: 
     
       1. A non-separating, stable composition consisting essentially of, in approximate parts by weight: (a) 20 to 60 parts of dibenzoyl peroxide or dibenzoyl peroxide having one or more substituents selected from halogen, lower alkyl or lower alkoxy;   (b) up to 20 parts of water;   (c) a hydrophobic reaction product of a pyrogenic silica with dimethyl dichlorosilane in an amount sufficient to prevent the composition from physically separating into its components, the composition having at least 2 parts of silica; and    (d) the remainder being a chemically inert plasticizer.   
     
     
       2. A composition according to claim 1 wherein the composition contains up to 2 parts by weight of a dye or pigment with which the active oxygen content of the peroxide in the composition remains substantially constant. 
     
     
       3. A non-separating, stable and pourable composition consisting essentially of, in approximate parts by weight: (a) 40 parts of dibenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-chlorobenzoyl peroxide or p-methoxybenzoyl peroxide;   (b) up to 16 parts of water;   (c) 2 to 6 parts of a hydrophobic reaction product of a pyrogenic silica with dimethyl dichlorosilane; and   (d) the remainder being a chemically inert plasticizer.   
     
     
       4. A non-separating, stable composition consisting essentially of, in approximate parts by weight: (a) 40 parts of dibenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-chlorobenzoyl peroxide or p-methoxybenzoyl peroxide;   (b) up to 16 parts of water;   (c) 2 to 6 parts of a hydrophobic reaction product of a pyrogenic silica with dimethyl dichlorosilane;   (d) up to 2 parts of a dye or pigment with which the active oxygen content of the peroxide in the composition remains substantially constant; and   (e) the remainder being a chemically inert plasticizer.   
     
     
       5. A non-separating, stable and pourable composition consisting essentially of, in approximate parts by weight: (a) 50 parts of dibenzoyl peroxide;   (b) up to 10 parts of water;   (c) 2 to 6 parts of hydrophobic reaction product of a pyrogenic silica with dimethyl dichlorosilane; and   (d) the remainder being a chemically inert plasticizer.   
     
     
       6. A non-separating, stable and pourable composition consisting essentially of, in approximate parts by weight: (a) 50 parts of dibenzoyl peroxide;   (b) up to 10 parts of water;   (c) 2 to 6 parts of hydrophobic reaction product of a pyrogenic silica with dichlorosilane;   (d) up to 1 part of a pigment or dye with which the active oxygen content of the peroxide in the composition remains substantially constant; and   (e) the remainder being a chemically inert plasticizer. .Iadd. 7. A non-separating, stable composition consisting essentially of, in approximate parts by weight:   (a) 20 to 60 parts of dibenzoyl peroxide or dibenzoyl peroxide having one or more substituents selected from halogen, lower alkyl or lower alkoxy;   (b) up to 20 parts of water;   (c) a hydrophobic reaction product of a pyrogenic silica with a lower alkyl chlorosilane in an amount sufficient to prevent the composition from physically separating into its components, the composition having at least 2 parts of silica; and   (d) the remainder being a chemically inert plasticizer. .Iaddend. .Iadd. 8. The composition of claim 7 wherein the hydrophobic reaction product is the reaction product of a pyrogenic silica and an alkyl chlorosilane wherein the alkyl groups are methyl, ethyl, n-propyl, iso-propyl, iso-butyl, n-butyl or tert. butyl. .Iaddend.