Aqueous organic peroxide emulsion

1 . An aqueous emulsion of organic peroxide, consisting of:

at least one peroxyester,

at least one antifreeze,

a combination of at least two emulsifiers selected from the group consisting of:

a non-ethoxylated sorbitan ester,

an ethoxylated sorbitan ester, and

an ethoxylated fatty alcohol,

optionally, one or more additives in a content between 10 ppm and 10,000 ppm by weight relative to the weight of the emulsion, and

water,

wherein the antifreeze comprises ethanol in combination with another alcohol selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,3-butanediol, 1,4-butanediol, and mixtures thereof.

2 . An aqueous emulsion of organic peroxide, comprising:

at least one peroxyester,

at least one antifreeze, and

a combination of at least two emulsifiers selected from the group consisting of:

a non-ethoxylated sorbitan ester,

an ethoxylated sorbitan ester, and

an ethoxylated fatty alcohol,

wherein the combination of said at least two emulsifiers has an HLB of less than 10,

wherein the emulsion does not comprise any methanol, and

wherein the antifreeze comprises ethanol in combination with another alcohol selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,3-butanediol, 1,4-butanediol, and mixtures thereof.

3 . The emulsion as claimed in claim 2 , wherein the non-ethoxylated sorbitan ester is selected from the group consisting of sorbitan monostearate, sorbitan tristearate, sorbitan monolaurate, sorbitan trilaurate, sorbitan monooleate, sorbitan trioleate, sorbitan monopalmitate, sorbitan tripalmitate and combinations thereof.

4 . The emulsion as claimed in claim 2 , wherein the ethoxylated sorbitan ester is selected from the group consisting of ethoxylated sorbitan monostearate, ethoxylated sorbitan tristearate, ethoxylated sorbitan monolaurate, ethoxylated sorbitan trilaurate, ethoxylated sorbitan monooleate, ethoxylated sorbitan trioleate, ethoxylated sorbitan monopalmitate, ethoxylated sorbitan tripalmitate and combinations thereof.

5 . The emulsion as claimed in claim 2 , wherein said at least two emulsifiers are present in a content ranging from 0.05% to 5% by weight of the emulsion.

6 . The emulsion as claimed in claim 2 , wherein said at least one organic peroxide is present in a content of between 30% to 70% by weight, relative to the total weight of the composition.

7 . The emulsion as claimed in claim 2 , wherein said at least one peroxyester is selected from the group consisting of:

peroxyneodecanoates,

peroxyneoheptanoates,

peroxypivalates,

peroxyethylhexanoates,

tert-butyl peroxyisobutyrate, and mixtures thereof.

8 . The emulsion as claimed in claim 2 , wherein said at least one antifreeze is selected from the group consisting of ethanol, ethylene glycol, isopropanol, n-propanol, 1,2-propanediol, 1,3-propanediol, glycerol, 1-butanol, 2-butanol, 1,3-butanediol and 1,4-butanediol and mixtures thereof.

9 . The emulsion as claimed in claim 2 , wherein it comprises between 5% and 25% by weight of antifreeze, relative to the total weight of the aqueous emulsion.

10 . The emulsion according to claim 2 , wherein the emulsion has a dynamic viscosity of less than 1000 mPa·s at −10° C. and a shear rate of 100 s −1 .

11 . The emulsion according to claim 10 , wherein the emulsion has a dynamic viscosity of less than 500 mPa·s at −10° C. and a shear rate of 100 s −1 .

12 . The emulsion according to claim 2 , wherein the emulsion has a flow time of less than 200 seconds as measured using a consistometric cup according to DIN 53211 with a viscosity cup diameter of 4 mm at a temperature of 5° C.

13 . The emulsion according to claim 12 , wherein the emulsion has a flow time of less than 100 seconds.

14 . The emulsion according to claim 2 , wherein the emulsion has a mean droplet size (d50) of less than or equal to 5 m and a maximum droplet size (d100) of less than or equal to 20 m after storage at −20° C. for 6 months.

15 . A process for polymerizing ethylenically unsaturated monomers, comprising a step of polymerization in the presence of the emulsion of claim 2 .

16 . The process of claim 15 , wherein the ethylenically unsaturated monomer is vinyl chloride.

17 . A process for preparing an aqueous emulsion of peroxyester that does not comprise any methanol, comprising a step a) of mixing:

at least one antifreeze,

a combination of at least two emulsifiers selected from the group consisting of 1) a non-ethoxylated sorbitan ester, 2) an ethoxylated sorbitan ester, and 3) an ethoxylated fatty alcohol, wherein the combination of said at least two emulsifiers has an HLB of less than 10,

water, and

at least one peroxyester,

wherein the antifreeze comprises ethanol in combination with another alcohol selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,3-butanediol, 1,4-butanediol, and mixtures thereof.

18 . An aqueous emulsion of organic peroxide, comprising:

at least one peroxyester,

at least one antifreeze, and

a combination of emulsifiers comprising an ethoxylated fatty alcohol that is a C 4 -C 30 fatty alcohol and at least one emulsifier selected from the group consisting of:

a non-ethoxylated sorbitan ester, and

an ethoxylated sorbitan ester,

wherein the combination of emulsifiers has an HLB of less than 13 and the emulsion does not comprise any methanol,

wherein the antifreeze comprises ethanol in combination with another alcohol selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,3-butanediol, 1,4-butanediol, and mixtures thereof.

19 . The emulsion of claim 18 , wherein the ethoxylated fatty alcohol is C 4 -C 20 .

20 . The emulsion of claim 18 , wherein the ethoxylated fatty alcohol is C 16 -C 18 linear or branched, cyclic or noncyclic, saturated or unsaturated, aromatic or nonaromatic fatty alcohol and contains between 3 and 80 alkylene oxide units.