Aqueous composition in the form of an emulsion comprising at least one peroxydicarbonate and at least one peroxyester

Abstract

The present invention relates to an aqueous composition in the form of an emulsion comprising at least one peroxydicarbonate and at least one peroxyester, preferably at least one hydroxyperoxyester. The invention also relates to the use of an aqueous composition comprising a mixture of organic peroxides as defined above for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, preferably halogenated monomers, and more preferably vinyl chloride.

Description

[0001] The present invention relates to an aqueous composition in the form of an emulsion comprising at least one peroxydicarbonate and at least one peroxyester, preferably at least one hydroxyperoxyester.

[0002] The invention also relates to the use of an aqueous composition comprising a mixture of organic peroxides as defined above for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, preferably halogenated and more preferentially vinyl chloride.

[0003] The invention also relates to halogenated vinyl polymers obtained by polymerization of at least one halogenated ethylenically unsaturated monomer in the presence of a mixture of organic peroxides as defined above.

[0004] Organic peroxides (in liquid or solid form) are commonly used as initiators for the polymerization of ethylenically unsaturated monomers in the synthesis of various types of polymers.

[0005] However, there is a certain amount of problems in their use frequently.Particularly, organic peroxide often constitutes highly unstable species, because it decomposes relatively easily under the effect of the slight input of heat, mechanical energy (friction or impact) or incompatible pollutant.Thereby, when some organic peroxide storage temperatures are uncontrolled and raised, they can stand the exothermic decomposition of self-acceleration, which can cause ignition and / or violent explosion.In addition, under these conditions, some of these organic peroxides can release combustible vapors, which can react with any ignition source, and this can increase or even promote the risk of violent explosion violently.As a result, it is important to take the precautionary measures of appropriate safety aspects during the storage and transportation of organic peroxide.

[0006] In order to overcome these drawbacks, organic peroxides are packaged in particular in the form of aqueous emulsions containing antifreeze agents. Thus, the presence of water makes it possible both to absorb and dissipate the energy generated in the case of exothermic decomposition of the organic peroxide, while at the same time the antifreeze agent serves to keep the emulsion in liquid form at temperatures below -10°C, generally below -15°C, which makes it possible to limit the risk of involuntary exothermic decomposition of the organic peroxide.

[0007] In general, the aqueous emulsion also contains an emulsifier which has the advantage of reducing the interfacial tension between the aqueous phase and the organic peroxide, with the aim of promoting the dispersion of the peroxide in the form of droplets and maintaining the size of said droplets over time. This is because, over time, the peroxide droplets can agglomerate together, leading to an increase in their average size and in their maximum size, which can in some cases lead to complete or partial phase separation and therefore to a general instability of the emulsion.

[0008] In view of the above, therefore, for safety reasons, the aqueous organic peroxide emulsion must be made stable, not only during its production, but also for a relatively long period of time, which corresponds to transportation and storage of the aqueous organic peroxide emulsion before it is used as a polymerization initiator. For this purpose, the organic peroxide droplets must primarily have an average size and a maximum size that are small and stable over time.

[0009] Furthermore, it is critical to obtain a homogeneous emulsion. In particular, the use of non-homogeneous organic peroxide emulsions (ie, emulsions having significant differences in organic peroxide concentration between the top and bottom of the aqueous phase) can also lead to unpredictable differences in initiator concentration in the polymerization reactor.

[0010] In addition, the following steps are important steps for the quality of the polymer obtained and the reliability of the polymerization process: the discharge of the emulsion in the intermediate storage silo, the pumping and introduction of the organic peroxide emulsion into the polymerization reactor. These operating steps must be carried out as quickly as possible. For this reason, it is important that the peroxide emulsion has a low viscosity so that the emulsion flow is promoted as much as possible. Thus, the organic peroxide emulsion should have a low viscosity at low temperatures (typically approximately -10°C) for 100s -1 The maximum dynamic viscosity is about 500-700 mPa.s for a shear rate of 1.5 %. The dynamic viscosity measurement is carried out, for example, according to standard DIN 53019 using a coaxial cylinder that generates shear.

[0011] However, the person skilled in the art knows that, for this type of emulsion, the quest to reduce the droplet size leads to an increase in viscosity (see the article by JP Canselier and M. Poux “Emulsification processes—Mechanism of emulsion formation” Techniques de l'Ingénieur J2 152, pp. 1-12, published on June 10, 2004, paragraph 1.4).

[0012] More precisely, the fact of seeking to reduce the size of the organic peroxide droplets and at the same time reduce the viscosity of the organic peroxide emulsion leads to conflicting effects that are difficult to reconcile.

[0013] In order to solve all these problems, aqueous organic peroxide emulsions have been developed in the prior art: they contain at least one organic peroxide, at least one specific nonionic surfactant as emulsifier, for example alkoxylated fatty alcohols and / or alkoxylated, optionally hydrogenated vegetable or animal oils, and an antifreeze agent, such as an alcohol, especially methanol.

[0014] However, such aqueous emulsions of organic peroxides have not yet proven to be sufficiently stable over time. In fact, it has been observed that, in a relatively short period of time, the average and maximum sizes of the peroxide liquids increase significantly, in some cases to the point of causing complete phase separation of the emulsions. For example, it has been found that, at a temperature of about -20°C or -25°C, some of these emulsions are unstable in less than 6 months, or even in less than 3 months, which naturally makes it difficult to carry out their transportation and storage in a completely safe manner.

[0015] One of the objects of the present invention is therefore to propose a composition in the form of an aqueous emulsion of an organic peroxide, which composition is stable and homogeneous over time and which is intended to be used as a polymerization initiator, without having the disadvantages previously described in terms of safety and quality of the product obtained.

[0016] In particular, one of the objects of the present invention is to propose an aqueous organic peroxide emulsion composition having, in particular, a low average droplet size, in particular less than 10 μm, preferably less than 5 μm, a uniform size distribution, a uniform distribution of the organic peroxide, and a maximum droplet size of less than 20 μm, or even less than 15 μm, in particular less than 5 μm, which is stable over time (for example over a period of 6 months), while complying with the required conditions in terms of viscosity and flow time of the emulsion.

[0017] Thus, a subject of the present invention is in particular an aqueous organic peroxide emulsion composition comprising:

[0018] - one or more organic peroxides of formula (I):

[0019]

[0020] In the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 an alkyl group which may contain and is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms;

[0021] - one or more organic peroxides of formula (II):

[0022]

[0023] In the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20An alkyl group which may contain and is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0024] Thus, the composition according to the invention has the advantage of being stable at a temperature of approximately -20°C or -25°C over a period of 6 months.

[0025] In particular, the composition according to the invention is an aqueous emulsion having, inter alia, a low average droplet size, preferably less than 10 μm, more preferably less than 5 μm, a uniform size distribution, a uniform distribution of the organic peroxide, and a maximum droplet size of less than 20 μm, or even less than 15 μm, which is stable over time, without phase separation or gelation in the organic and aqueous phases.

[0026] More precisely, the average droplet size (d 50 ) is less than 10 μm; during this period, the maximum droplet size (d 100 ) does not exceed 20μm.

[0027] Furthermore, the composition according to the invention has the advantage of being stable at a temperature of approximately -20°C or -25°C over a period of six months.

[0028] The term "uniform" means that the organic peroxide has a small concentration gradient. In other words, samples taken at different locations in the emulsion have similar organic peroxide concentrations (i.e., preferably less than 5% absolute difference, preferably less than 3% absolute difference, more preferably less than 2% absolute difference). Thus, advantageously, when the composition according to the present invention is packaged in a storage container, the difference in the organic peroxide concentration distributed between the upper and lower parts of the container remains less than 3%, or even less than 2% over time (especially over a period of 6 months), which makes it possible to ensure the reproducibility of the polymerization rate.

[0029] This thus allows withdrawing the composition according to the invention from the top or bottom of the vessel to initiate the polymerization of the ethylenically unsaturated monomers at a similar and reproducible rate.

[0030] As a result, the composition according to the invention remains effective over time.

[0031] Further, the composition according to the invention has a low viscosity, preferably less than 850 mPa.s, preferably less than 700 mPa.s, more preferably less than 500 mPa.s, which allows very short flow times.

[0032] The dynamic viscosity measurement can be measured, for example, according to standard DIN 53019 using a coaxial cylinder that generates shear.

[0033] Thus, the composition according to the invention can be safely transported and stored in a polymerization production unit and a polymeric material of good quality is obtained.

[0034] In a clear manner, the composition according to the invention makes it possible to improve the transparency of the final polymeric material.

[0035] A subject of the invention is also the use of an aqueous composition comprising a mixture of organic peroxides as defined above for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, in particular vinyl monomers, preferably halogenated vinyl monomers, and more preferentially vinyl chloride.

[0036] Thus, the aqueous composition comprising the mixture of organic peroxides can be used as a polymerization initiator for the synthesis of polymers or copolymers obtained from one or more ethylenically unsaturated monomers.

[0037] Thus, the composition is compatible with the polymerization or copolymerization of ethylenically unsaturated monomers, preferably vinyl monomers.

[0038] Furthermore, the present invention also relates to halogenated vinyl polymers obtained by polymerization of at least one halogenated ethylenically unsaturated monomer in the presence of an aqueous composition containing a mixture of organic peroxides as described above.

[0039] Other characteristics and advantages of the invention will become more apparent on reading the following description and examples.

[0040] In the following text, unless otherwise stated, the limits of a numerical range are included in the range.

[0041] The expression "at least one" is equivalent to the expression "one or more".

[0042] Composition

[0043] As previously stated, the composition according to the invention comprises one or more organic peroxides of formula (I):

[0044]

[0045] In the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms.

[0046] Preferably, R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 16 , more priority C3-C 12 , especially C3-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms.

[0047] Preferably, R 1 and R 2 Can be the same or different, indicating linear type C1-C 16 , more priority C3-C 12 , especially C3-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms.

[0048] Preferably, R 1 and R 2 Can be the same or different, indicating branched C1-C 16 , more priority C3-C 12 , especially C3-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms.

[0049] Preferably, R 1 and R 2 Can be the same or different, indicating a cyclic C1-C 16 , more priority C3-C 12 , especially C3-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms.

[0050] For the purposes of the present invention, the term "cyclic alkyl group" means that the alkyl group comprises a ring, preferably an aromatic ring, which comprises a 5 or 6-membered ring.

[0051] Preferably, the heteroatom is an oxygen atom.

[0052] Preferably, R 1 and R 2 are the same and represent a linear or branched, preferably branched C2-C 16 , especially C3-C 12 , and even more preferentially C3-C 10Alkyl group.

[0053] Prioritize, R 1 and R 2 are identical and represent a linear or branched, preferably branched, C2-C8 alkyl group.

[0054] The organic peroxide of formula (I) is preferably selected from bis(2-ethylhexyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, bis(1-methylheptyl) peroxydicarbonate, di(n-propyl) peroxydicarbonate, bis(3-methoxybutyl) peroxydicarbonate, diethyl peroxycarbonate, and mixtures thereof, preferably selected from bis(2-ethylhexyl) peroxydicarbonate and di(sec-butyl) peroxydicarbonate.

[0055] Advantageously, the organic peroxide of formula (I) is selected from bis(2-ethylhexyl) peroxydicarbonate (known under the trade name 223) and di(sec-butyl) peroxydicarbonate (sold under the trade name 225 sales).

[0056] As previously mentioned, the composition according to the invention also comprises one or more organic peroxides of formula (II):

[0057]

[0058] In the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0059] Preferably, R 3 and R 4 Can be the same or different, representing a linear or branched C7-C 20 , preferably C7-C 16 , and especially C7-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0060] Preferably, R 3 and R 4 Can be the same or different, indicating linear type C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0061] Preferably, R 3 and R 4 Can be the same or different, indicating branched C7-C 20 , preferably C7-C 16 Alkyl groups, especially C7-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0062] Preferably, R 3 and R 4 Can be the same or different, indicating a cyclic C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 The alkyl group, which may contain one or more heteroatoms, preferably one or more oxygen atoms, is preferably interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or is optionally substituted by one or more hydroxyl groups.

[0063] For the purposes of the present invention, the term "cyclic alkyl group" means a linear or branched alkyl group which also comprises a ring, preferably an aromatic ring, preferably comprising a 5- or 6-membered ring.

[0064] In other words, for the purposes of the present invention, a cyclic alkyl group includes a linear or branched, preferably C2-C4 alkyl group and a ring, which is preferably an aromatic ring, preferably including a 5 or 6 membered ring.

[0065] Preferably, the cyclic alkyl group comprises a branched, preferably C2-C4 alkyl group and an aromatic ring, the aromatic ring preferably comprising a 5 or 6 membered ring.

[0066] Preferably, R 3 and R 4 may be identical or different and represent an alkyl group as defined above, which may be interrupted by one or more heteroatoms, preferably one or more oxygen atoms, and / or optionally substituted by one or more hydroxyl groups.

[0067] Preferably, R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may be optionally substituted with one or more hydroxy groups.

[0068] Preferably, R 3 Indicates linear or branched C7-C 20 , preferably C7-C 16 , especially C7-C 10 an alkyl group which may contain, preferably be interrupted by, one or more heteroatoms, preferably one or more oxygen atoms, and R 4 represents a linear or branched C1-C7, preferably C2-C6 alkyl group, which may optionally be replaced by one or more hydroxyl groups, or a cyclic C7-C 16 , especially C7-C 10 Alkyl group substitution.

[0069] Preferably, R 3 Indicates branched C7-C 20 , preferably C7-C 16 , especially C7-C 10 an alkyl group which may contain, preferably be interrupted by, one or more heteroatoms, preferably one or more oxygen atoms, and R 4 represents a branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups.

[0070] Preferably, the heteroatom is an oxygen atom.

[0071] Preferably, in formula (II):

[0072] -R 3 represents a linear, branched or cyclic, preferably a branched C7-C 20 Alkyl group, preferably C7-C 16 Alkyl groups, especially C7-C 10 an alkyl group which may be interrupted by one or more oxygen atoms, preferably one oxygen atom;

[0073] -R 4 express:

[0074] i) linear or branched, preferably branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 an alkyl group which may be interrupted by one or more oxygen atoms, preferably one oxygen atom;

[0075] ii) a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups; or

[0076] iii) Cyclic C7-C 10 , especially a cyclic C9 alkyl group.

[0077] Preferably, in formula (II), R 3 represents a linear or branched, preferably a branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 Alkyl group.

[0078] Preferably, in formula (II), R 4 express:

[0079] a linear or branched, preferably branched C1-C7, preferably C2-C6, in particular C4 or C6 alkyl group, which is optionally substituted by one or more hydroxyl groups,

[0080] -Cyclic C7-C 10 , especially a C9 alkyl group.

[0081] Preferably, in formula (II), when R 4 Indicates cyclic C7-C 10 When the alkyl group is 4 It includes linear or branched, preferably branched C2-C4, especially C3 alkyl groups, and rings, preferably aromatic rings, preferably including 5 or 6 membered rings.

[0082] Even more preferentially, R 4 represents a linear or branched, preferably branched C1-C7, preferably C2-C6, in particular C6 alkyl group, which is substituted by one or more hydroxyl groups, in particular one hydroxyl group.

[0083] Advantageously, in formula (II):

[0084] -R 3 represents a linear or branched, preferably a branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 Alkyl group.

[0085] -R 4 represents a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups.

[0086] The organic peroxide of formula (II) is preferably selected from the group consisting of α-cumyl peroxyneodecanoate, α-cumyl peroxyneoheptanoate, 2,4,4-trimethylpentan-2-yl peroxyneodecanoate, tert-butyl peroxy(n-heptanoate), tert-butyl peroxyneodecanoate, α-cumyl peroxy(n-heptanoate), tert-amyl peroxy(n-heptanoate), tert-butyl peroxyneodecanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoyl)peroxy )hexane, tert-amyl peroxy(2-ethylhexanoate), tert-butyl peroxy(2-ethylhexanoate), 1,1,3,3-tetramethylbutyl peroxy(2-ethylhexanoate), hydroxyperoxyesters, tert-amyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-hexyl peroxyneodecanoate, tert-hexyl peroxypivalate, and mixtures thereof.

[0087] Preferably, the peroxyester is selected from hydroxyperoxyesters.

[0088] Advantageously, the hydroxyperoxyester is advantageously selected from 4-hydroxy-2-methylpentyl peroxyneodecanoate, 4-hydroxy-2-methylpentyl peroxyneoheptanoate, 4-hydroxy-2-methylpentyl peroxy(2-ethylhexanoate), 4-hydroxy-2-methylpentyl peroxy(2-phenylbutyrate), 4-hydroxy-2-methylpentyl peroxy(2-phenoxypropionic acid), 4-hydroxy-2-methylpentyl peroxy(2-butyloctanoate), 4-hydroxy-2-methylpentyl peroxyneohexanoate, 4-hydroxy-2-methylpentyl peroxyneotridecanoate, 4-hydroxy-2-methylhexyl peroxyneohexanoate, 4-hydroxy-2-methylhexyl peroxyneodecanoate, 5-hydroxy-1,3,3-trimethylcyclohexyl peroxyneodecanoate, 4-hydroxy-2,6-dimethyl-2,6-di(neohexanoylperoxy)heptane, 4-hydroxy-2,6-dimethyl-2,6-di(neodecanoylperoxy)heptane, 3-hydroxy-1,1-dimethylbutyl peroxy(2-ethylhexanoate), 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, 3-hydroxy-1,1-dimethylbutyl peroxyneoheptanoate, and mixtures thereof, preferably selected from 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate.

[0089] Preferably, the organic peroxide of formula (II) is selected from the group consisting of tert-butyl peroxyneodecanoate, tert-amyl peroxyneodecanoate, α-cumyl peroxyneoheptanoate, hydroxyperoxyesters, and mixtures thereof.

[0090] Preferably, the organic peroxide of formula (II) is selected from: 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (available from Arkema under the trade name 610), α-cumyl peroxyneoheptanoate (sold under the trade name 188), tert-amyl peroxyneodecanoate (trade name 546), and tert-butyl peroxyneodecanoate (sold by Arkema under the trade name 10 sales), and mixtures thereof.

[0091] Preferably, the organic peroxide of formula (II) is selected from: 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (available from Arkema under the trade name 610), and tert-butyl peroxyneodecanoate (sold by Arkema under the trade name 10 sales), and mixtures thereof.

[0092] Advantageously, the organic peroxide of formula (II) is 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (available from Arkema under the trade name 610 sales).

[0093] The organic peroxide of formula (I) and the organic peroxide of formula (II) are preferably present in a concentration ranging from 40% to 70% by weight (relative to the total weight of the composition), preferably in a concentration ranging from 40% to 65% by weight (relative to the total weight of the composition), and more preferably in a concentration ranging from 40% to 60% by weight (relative to the total weight of the composition). In other words, the concentration of the organic peroxide of formula (I) plus the concentration of the organic peroxide of formula (II) preferably accounts for the following concentration: ranging from 40% to 70% by weight (relative to the total weight of the composition), preferably ranging from 40% to 65% by weight (relative to the total weight of the composition), and more preferably ranging from 40% to 60% by weight (relative to the total weight of the composition).

[0094] Preferably, the total concentration of the organic peroxide in the composition ranges from 40% to 70% by weight (relative to the total weight of the composition), preferably from 40% to 65% by weight (relative to the total weight of the composition), more preferably from 40% to 60% by weight.

[0095] Preferably, only organic peroxides of formula (I) and formula (II) are present in the composition.

[0096] Preferably, the weight ratio of the organic peroxide of formula (I) / the organic peroxide of formula (II) ranges from 1 / 99 to 99 / 1, preferably from 2 / 98 to 98 / 2.

[0097] According to another embodiment, the weight ratio of organic peroxide of formula (I) / organic peroxide of formula (II) ranges from 10 / 90, in particular from 20 / 80 to 50 / 50.

[0098] According to another embodiment, the weight ratio of organic peroxide of formula (I) / organic peroxide of formula (II) ranges from 99 / 1, in particular from 97 / 3, in particular from 90 / 10, and preferentially from 80 / 20 to 50 / 50.

[0099] Advantageously, the organic peroxides of formula (I) and (II) have a 1 hour half-life temperature less than or equal to 90°C, preferably less than 90°C.

[0100] Furthermore, advantageously, the storage temperature of the organic peroxides of formula (I) and formula (II) is below 0°C.

[0101] The organic peroxides of formula (I) and formula (II) are advantageously liquid at storage temperature, preferably at a storage temperature below 0° C., measured at atmospheric pressure.

[0102] Preferably, the composition according to the invention comprises:

[0103] - one or more organic peroxides of formula (I):

[0104]

[0105] In the formula (I), R 1 and R 2 are the same and represent a linear or branched, preferably branched C1-C 16 , especially C3-C 12 , or even more preferentially C3-C 10 Alkyl groups;

[0106] - one or more organic peroxides of formula (II):

[0107]

[0108] In the formula (II):

[0109] -R 3 represents a linear, branched or cyclic, preferably a branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 An alkyl group which may contain one or more oxygen atoms, preferably one oxygen atom, and which is preferably interrupted by one or more oxygen atoms, preferably one oxygen atom -R 4 express:

[0110] i) linear or branched, preferably branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10an alkyl group which may contain one or more oxygen atoms, preferably one oxygen atom, and is preferably interrupted by one or more oxygen atoms, preferably one oxygen atom;

[0111] ii) a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups; or

[0112] iii) Cyclic C7-C 10 , especially a cyclic C9 alkyl group.

[0113] Advantageously, according to this preferred embodiment, in formula (I), R 1 and R 2 are identical and represent a linear or branched, preferably branched, C2-C8 alkyl group.

[0114] Advantageously, according to this preferred embodiment, R 3 and R 4 different.

[0115] Even more advantageously, according to this preferred embodiment, in formula (II):

[0116] -R 3 represents a linear or branched, preferably linear C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 Alkyl groups;

[0117] -R 4 represents a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups.

[0118] Also advantageously, according to this preferred embodiment, in formula (II), R 4 represents a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups.

[0119] Also advantageously, according to this preferred embodiment, in formula (II), R 4 represents a linear or branched, preferably branched, C1-C7, preferably C2-C6 alkyl group, which is substituted by one or more hydroxyl groups, in particular one hydroxyl group.

[0120] More advantageously, the composition according to the invention comprises bis(2-ethylhexyl) peroxydicarbonate (particularly sold under the trade name 223), or di-sec-butyl peroxydicarbonate (particularly sold under the trade name 225), and a hydroxyperoxyester of formula (II), preferably 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (particularly sold under the trade name 610 sales).

[0121] Preferably, the composition may comprise one or more antifreeze agents, preferably selected from monohydric alcohols, dihydric alcohols and trihydric alcohols.

[0122] Preferably, the antifreeze agent is selected from methanol, ethanol, ethylene glycol, isopropanol, n-propanol, propane-1,2-diol, propane-1,3-diol, glycerol, butane-1-ol, butane-2-ol, butane-1,3-diol, and butane-1,4-diol, and mixtures thereof, the mixture comprising at least two of the antifreeze agents listed previously, advantageously a mixture of ethanol and propane-1,2-diol.

[0123] Preferably, the antifreeze agent is selected from methanol, ethanol, and propane-1,2-diol, and mixtures thereof, in particular a mixture of ethanol and propane-1,2-diol. Particularly preferably, the antifreeze agent is propane-1,2-diol.

[0124] The antifreeze agent is preferably present in the composition according to the invention in a content of less than 40% by weight, preferably less than 25% by weight and preferably less than 22% by weight relative to the total weight of the composition. Such an antifreeze agent content allows the aqueous phase to be maintained in liquid form at temperatures as low as below -20°C, preferably at temperatures as low as below -25°C.

[0125] Preferably, the composition according to the invention contains less than 10% by weight of ethanol relative to the total weight of the composition.

[0126] Preferably, the composition according to the invention is free of ethanol.

[0127] Preferably, the composition according to the invention contains less than 10% by weight of methanol relative to the total weight of the composition.

[0128] Preferably, the composition according to the invention is free of methanol.

[0129] Preferably, the composition according to the invention comprises less than 10% by weight of ethanol or methanol relative to the total weight of the composition. If the composition according to the invention comprises both ethanol and methanol, their total content by weight is less than 10% relative to the total weight of the composition.

[0130] The composition according to the invention may also comprise one or more emulsifiers.

[0131] Preferably, the emulsifier is a nonionic surfactant.

[0132] Preferably, the emulsifier is a nonionic surfactant, which may or may not be oxyalkylened, selected from fatty alcohols, fatty acids, sorbitan, vegetable or animal oils (which may or may not be hydrogenated); or mixtures thereof.

[0133] The oxyalkylene units are more particularly oxyethylene units (ie ethylene oxide groups), oxypropylene units (ie propylene oxide groups), or a combination thereof, preferably oxyethylene units or a combination of oxyethylene units and oxypropylene units.

[0134] In other words, the nonionic surfactant is preferably selected from: fatty alcohols containing oxyethylene units and optionally oxypropylene units, fatty acids containing oxyethylene units and optionally oxypropylene units, and optionally hydrogenated vegetable or animal oils containing oxyethylene units and optionally oxypropylene units.

[0135] The oxyethylene units (ie, ethylene oxide groups) and the oxypropylene units (ie, propylene oxide groups) may be distributed randomly or in the form of blocks.

[0136] The number of moles of ethylene oxide and / or propylene oxide preferably ranges from 1 to 250, more particularly from 2 to 100, still more preferably from 2 to 50, and more particularly from 2 to 40.

[0137] Preferably, the mole number of ethylene oxide ranges from 2 to 40.

[0138] For the purposes of the present invention, the term "fatty alcohol" means an alcohol comprising at least 8 carbon atoms, preferably C8-C 40 Alcohols, preferably C8-C 20 alcohol.

[0139] Among the fatty alcohols, mention may especially be made of: 2-octyldodecanol, decanol, lauryl alcohol, oleocetyl alcohol, isodecanol, oxyisotridecyl alcohol, cetostrearyl alcohol, capryl alcohol, myristyl alcohol, cetyl or palmityl alcohol, stearyl alcohol, eicosanyl or arachidyl alcohol, behenyl alcohol, oleyl alcohol, eicosenyl alcohol or gadoleyl alcohol, docosenyl alcohol, ricinoleyl alcohol, linoleyl alcohol and linolenyl alcohol.

[0140] Preferably, the nonionic surfactant is chosen from oxyalkylened fatty alcohols, preferably from octyldodecanol, decanol, lauryl alcohol, oleyl cetyl alcohol, isodecyl alcohol, octanol, oxyisotridecyl alcohol, cetostearyl alcohol, octadecanol, caprylyl alcohol, myristyl alcohol, cetyl alcohol or palmityl alcohol, stearyl alcohol, eicosanol or arachidyl alcohol, behenyl alcohol, oleyl alcohol, eicosanol or eicosenyl alcohol, erucicol, ricinoleyl alcohol, linoleyl alcohol or linolenic alcohol, which are oxyalkylened, preferably oxyethylened and / or oxypropylened, and more preferentially oxyethylened and optionally oxypropylened.

[0141] Preferably, the oxyalkylened fatty alcohol is selected from oxyethylened linoleyl alcohol, oxyethylened linoleyl alcohol, oxyethylened cetearyl alcohol, and mixtures thereof.

[0142] The fatty alcohols mentioned hereinbefore may optionally be oxypropyleneated to a minor extent.

[0143] Preferably, the oxyalkylened vegetable / animal oils (which may or may not be hydrogenated) are derivatives of, in particular, ethoxylated mono-, di- and triglycerides and comprise a complex mixture of ethoxylated glycerol optionally linked to one or more fatty acid chains (which may or may not themselves be ethoxylated), fatty acids ethoxylated on the acid functions and / or on the hydroxyl functions carried by the fatty acid chains, and variable proportions of fatty acids, glycerol and fatty acid mono-, di- or triglycerides.

[0144] For the purposes of the present invention, the term "fatty acid" means an acid or a mixture of acids comprising at least 6 carbon atoms, preferably 6 to 60 carbon atoms, more preferentially 6 to 20 carbon atoms.

[0145] The oxyalkylenated vegetable / animal oil (which may or may not be hydrogenated) is preferably selected from optionally hydrogenated, oxyethylenated (or ethoxylated) vegetable oils.

[0146] The optionally hydrogenated, oxyethylenated vegetable oils are preferably chosen from ethoxylated castor oils and ethoxylated hydrogenated castor oils, which contain from 20 to 40 mol of ethylene oxide per 1 mol of ricinoleic acid. Mention may also be made of ethoxylated oils derived from coconut kernel oil, palm oil, palm kernel oil, olive oil, peanut oil, rapeseed oil, soybean oil, sunflower oil, walnut oil, hazelnut oil, coconut oil, poppy oil, safflower oil, linseed oil, perilla oil, oitica oil, and china wood oil.

[0147] Mention may also be made of fats based on the following ethoxylations: (animal, cattle, sheep) tallow, crude or refined tall oil, whale oil, herring oil and sardine oil. All of these ethoxylated glyceride derivatives are characterized in that they comprise a mixture of ethoxylated mono-, di- or tri-glycerides and corresponding fatty acids and glycerol ethoxylated derivatives. These fatty acids are especially saturated or unsaturated fatty acids derived from the following: caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, myristoleic acid, palmitoleic acid, oleic acid, ricinoleic acid, erucic acid, linoleic acid, linolenic acid, oleostrearic acid, 18 carbon-9,11,13-triene-4-keto acid (licanic acid), 9-eicosenoic acid (gadoleic acid) and / or erneic acid (erneic acid). Some unsaturated fatty acids may or may not be hydrogenated, such as in the case of ethoxylated castor oil, in which the ricinoleic acid groups may or may not be partially or fully hydrogenated.

[0148] Preferably, the nonionic surfactant is selected from oxyalkylenated vegetable or animal oils (which may or may not be hydrogenated).

[0149] Preferentially, the nonionic surfactant is chosen from vegetable oils, which are optionally hydrogenated, oxyethylened and optionally oxypropylened.

[0150] More preferentially, the nonionic surfactant is chosen from ethoxylated, optionally hydrogenated vegetable oils comprising from 20 to 40 mol of ethylene oxide, in particular ethoxylated castor oil and ethoxylated hydrogenated castor oil comprising from 20 to 40 mol of ethylene oxide.

[0151] Even more preferentially, the nonionic surfactant is ethoxylated castor oil comprising from 20 to 40 mol of ethylene oxide.

[0152] The emulsifier may be present in the composition according to the invention in a content ranging from 0.1% to 10% by weight, preferably in a content ranging from 0.5% to 5% by weight, relative to the total weight of the composition.

[0153] Preferably, the emulsifier according to the invention does not contain any partially hydrolyzed polyvinyl acetate, more preferentially does not contain any polyvinyl acetate, more preferentially does not contain any polyvinyl acetate or cellulose ester. This makes it possible in particular to reduce the industrial preparation time, since polyvinyl acetate in solid form requires a prior dissolution step, and to minimize the risks associated with the handling of powders.

[0154] The composition according to the invention may also contain one or more additives intended to provide specific properties / characteristics to the final composition. Ideally, these additives will be present for the final polymerization or copolymerization.

[0155] The additive may be selected from defoamers, chain transfer agents, chain extenders, pH adjusters, plasticizers, and mixtures thereof.

[0156] Preferably, the composition according to the invention comprises one or more plasticizers, preferably selected from phthalates, adipates, benzoates, and hydrogenated derivatives of these molecules, including in particular diisononylcyclohexane, diisononylcyclohexanedicarboxylate, and mixtures thereof. Preferably, the composition according to the invention comprises:

[0157] - one or more organic peroxides of formula (I):

[0158]

[0159] In the formula (I), R 1 and R 2 are the same and represent a linear or branched, preferably branched C1-C 16 , especially C3-C 12 , or even more preferentially C3-C 10 Alkyl groups;

[0160] - one or more organic peroxides of formula (II):

[0161]

[0162] In the formula (II):

[0163] -R 3 represents a linear, branched or cyclic, preferably a branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 an alkyl group which may contain one or more oxygen atoms, preferably one oxygen atom, and is preferably interrupted by one or more oxygen atoms, preferably one oxygen atom;

[0164] -R 4 express:

[0165] i) linear or branched, preferably branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10an alkyl group which may contain one or more oxygen atoms, preferably one oxygen atom, and is preferably interrupted by one or more oxygen atoms, preferably one oxygen atom;

[0166] ii) a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups; or

[0167] iii) Cyclic C7-C 10 , especially a cyclic C9 alkyl group.

[0168] one or more emulsifiers, preferably chosen from alkoxylated fatty alcohols, alkoxylated fatty acids, and alkoxylated vegetable or animal oils (which may or may not be hydrogenated), or mixtures thereof, preferably chosen from alkoxylated, optionally hydrogenated vegetable oils,

[0169] - Optionally one or more antifreeze agents, preferably selected from ethanol, methanol, and propane-1,2-diol.

[0170] Preferably, the composition according to the invention comprises:

[0171] - one or more organic peroxides of formula (I):

[0172]

[0173] In the formula (I), R 1 and R 2 are the same and represent a linear or branched, preferably branched C1-C 16 , especially C3-C 12 , or even more preferentially C3-C 10 Alkyl groups;

[0174] - one or more organic peroxides of formula (II),

[0175]

[0176] In the formula (II):

[0177] -R 3 represents a linear or branched, preferably a branched C7-C 20 Alkyl groups, preferably C7-C 16 Alkyl groups, especially C7-C 10 Alkyl groups;

[0178] -R 4 represents a linear or branched, preferably branched C1-C7, preferably C2-C6 alkyl group, which is optionally substituted by one or more hydroxyl groups;

[0179] - one or more emulsifiers chosen from nonionic surfactants, preferably chosen from alkoxylated fatty alcohols, alkoxylated fatty acids, and alkoxylated vegetable or animal oils (which may or may not be hydrogenated), or mixtures thereof;

[0180] - Optionally one or more antifreeze agents, preferably selected from ethanol, methanol, and propane-1,2-diol.

[0181] Preparation of composition

[0182] Preferably, the composition according to the present invention can be prepared according to a process comprising the following steps in sequence:

[0183] (i) Mix the following:

[0184] (a) at least one organic peroxide of formula (I):

[0185]

[0186] In the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 an alkyl group which may contain one or more heteroatoms, preferably one or more oxygen atoms; and

[0187] (b) at least one organic peroxide of formula (II):

[0188]

[0189] In the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 an alkyl group which may contain one or more heteroatoms, preferably one or more oxygen atoms, and / or be optionally substituted with one or more hydroxyl groups;

[0190] (ii) optionally emulsifying the mixture.

[0191] Thus, the present invention also relates to a process for preparing a composition according to the invention, which process comprises, in sequence, (i) mixing: (a) at least one organic peroxide of formula (I) as defined above, and (b) at least one organic peroxide of formula (II) as defined above, and (ii) emulsifying the mixture.

[0192] In other words, the process for preparing the composition may comprise, in sequence: (i) at least one step of mixing: (a) at least one organic peroxide of formula (I) as defined hereinbefore, and (b) at least one organic peroxide of formula (II) as defined hereinbefore, and (ii) optionally at least one step of emulsifying the mixture.

[0193] Preferably, the process according to the invention involves, in sequence:

[0194] - adding at least one emulsifier as defined above to water,

[0195] - mixing in an aqueous phase at least one organic peroxide of formula (I) as defined above, and at least one peroxide of formula (II) as defined above,

[0196] - Emulsifying the mixture.

[0197] The composition according to the invention can be prepared by dispersing at least an emulsifier and optionally one or more antifreeze agents and one or more additives in water to obtain a homogeneous aqueous phase and then adding to said aqueous phase one or more organic peroxides of formula (I) and (II), followed by emulsifying the whole in an emulsification step at a temperature below 5° C. (Celsius), and preferably below −5° C., in order to limit premature degradation of the peroxides.

[0198] The above steps may be performed in the specific order described above, or in a different order.

[0199] The temperature at which the emulsion is prepared is not critical, but it must be low enough to avoid a high decomposition rate of the organic peroxide, which would result in a loss of titer. The temperature chosen depends on the organic peroxide. In addition, deionized water or distilled water is conventionally used to prepare the aqueous emulsion. The preparation process includes a step of emulsification using a high shear mixer to differentiate and / or homogenize the peroxide in the aqueous phase as much as possible. Examples that may be mentioned include: mechanically rotating blades and anchor stirrers, impeller stirrers (i.e. one or more stirrers mounted on a common shaft), turbine stirrers (i.e. those stirrers that include baffles connected to the mixing vessel or adjacent to the stirrer member). Colloid mills and homogenizers may also be used.

[0200] According to one embodiment feature, the process according to the invention is characterized in that an ultrasonic mixer or a rotor-stator mixer is used. After the emulsion is prepared, the step of pumping and introducing the emulsion into the polymerization reactor should be carried out as soon as possible. Therefore, the peroxide emulsion should have a low viscosity. Thus, immediately after production, the organic peroxide emulsion according to the invention has the following viscosity at -10°C and 100s -1The dynamic viscosity range is less than 850 mPa.s, preferably less than 700 mPa.s, and preferentially less than 500 mPa.s (the viscosity is measured, for example, according to standard DIN 53019 using a machine such as Haake VT550 Viscotester at -10°C and for 100 s -1 The shear rate is measured, which is well known to those skilled in the art).

[0201] Its fluidity or flow time (measured by the consistency cup technique) is less than 200 seconds, preferably less than 100 seconds (DIN 53211, viscosity cup diameter 4 mm, temperature 5° C.) Within the context of the present invention, the subsequent polymerization or copolymerization step does not differ from the polymerization or copolymerization steps of the prior art.

[0202] use

[0203] The invention also relates to the use of an aqueous emulsion composition comprising a mixture of organic peroxides as defined above for the polymerization or copolymerization of one or more ethylenically unsaturated monomers, in particular one or more vinyl monomers, preferably halogenated vinyl monomers, and more preferentially vinyl chloride.

[0204] As ethylenically unsaturated monomers, mention may be made of acrylates, vinyl esters, vinyl halide monomers, vinyl ethers, butadiene or vinyl aromatic compounds, such as styrene.

[0205] Preferably, the ethylenically unsaturated monomer is selected from vinyl halide monomers (ie, halogenated vinyl monomers), and more preferably the ethylenically unsaturated monomer is vinyl chloride.

[0206] polymer

[0207] Another subject of the invention relates to a halogenated vinyl polymer obtained by polymerization of at least one ethylenically unsaturated monomer, as defined above, in the presence of a composition according to the invention as defined above.

[0208] Preferably, the invention relates to poly(vinyl chloride) obtained by polymerization of vinyl chloride in the presence of a composition according to the invention, in particular in the presence of a mixture of organic peroxides as defined above.

[0209] In particular, the polymerization of vinyl chloride monomer occurs in suspension at an initiation temperature ranging from 45°C to 70°C.

[0210] The following examples serve to illustrate the invention but are not limiting in nature. Example

[0211] Example 1

[0212] The following compositions A1, A2, A3 and B1 were prepared according to the procedure described below.

[0213] Emulsifier and antifreeze are added to the water.

[0214] The aqueous phase containing the emulsifier (ie the nonionic surfactant), antifreeze agent and water is stirred at between 500 and 1000 revolutions per minute (rpm) and maintained at -5°C (Celsius) to obtain a homogeneous aqueous phase.

[0215] The organic peroxide was gradually added to the reactor containing this water / surfactant / antifreeze mixture. Stirring was continued at 2000 rpm for 3 minutes. Subsequently, the whole was vigorously stirred at 9500 rpm for 2 minutes using an ultrasonic machine such as Ultra-Turrax S-25N 18G, followed by stirring at 1000 rpm using a paddle for 1 minute. Each emulsification was performed with a total of 200 g.

[0216] Tests performed:

[0217] The dynamic viscosity measurement is carried out using a viscometer such as a Haake VT550 Viscotester machine. The test equipment is SV-DIN 53019, with reference to standard DIN 53019. The measurement is carried out using a coaxial cylinder that generates shear. Between 5 and 10 ml (milliliters) of the emulsion are introduced into a measuring chamber maintained at -10°C. The values ​​given in the following examples correspond to 100 s -1 The shear rate is given in mPa.s. The accuracy of the measurement is ±10% of the value shown.

[0218] The flow time measurement is carried out according to standard DIN 53211 using a consistency cup (viscosity cup diameter: 4 mm), which is well known to the person skilled in the art. The measurement is carried out on 100 g of the emulsion after conditioning at +5° C. The flow time measurement is expressed in seconds and has an accuracy of ±10% of the indicated value.

[0219] The mean droplet size and the maximum droplet size are determined by conventional means using light scattering techniques over a period of 1 to 6 months at a temperature of -25°C / -20°C.

[0220] At room temperature, using a Malvern Mastersizer The device performs the measurements. The average droplet size and the maximum droplet size are given with an accuracy of ±0.5 μm (micrometer).

[0221] Composition:

[0222] The amounts of the following ingredients are expressed as weight percent relative to the total weight of the composition in Table 1 below:

[0223] [Table 1]

[0224]

[0225] result:

[0226] When producing the composition

[0227] The average droplet size, maximum droplet size and viscosity cup results for the production of compositions A1, A2, A3 and B1 are collated in Table 2 below:

[0228] [Table 2]

[0229]

[0230] The results show that the composition according to the invention (composition B) has a smaller average droplet size (μm) and a smaller maximum droplet size than comparative compositions A1, A2 and A3 which do not contain such an organic peroxide mixture.

[0231] Stability of the test composition

[0232] For the test compositions stored in a freezer at -20°C, the mean and maximum droplet sizes for Composition B measured at 6 months were 2.2 and 7.6 μm, respectively.

[0233] Embodiment 2:

[0234] According to a procedure similar to that described in Example 1, compositions A4 and A5 were prepared, composition A4 corresponding to bis(2-ethylhexyl) peroxydicarbonate ( 223), composition A5 corresponds to 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate ( 610) aqueous emulsion.

[0235] Composition B2 was prepared by mixing together 67% by weight of composition A4 and 33% by weight of composition A5.

[0236] Composition B3 was prepared by adding bis(2-ethylhexyl) peroxydicarbonate and 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate in a weight ratio of 67 / 33 in the aqueous phase according to the procedure described in Example 1 .

[0237] Compositions A4, A5, B2 and B3 are described in Tables 3 to 5 below.

[0238] Composition:

[0239] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of compositions A4 and A5 in Table 3 below:

[0240] [Table 3]

[0241]

[0242] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B2 in Table 4 below:

[0243] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B2 in Table 4 below:

[0244] [Table 4]

[0245]

[0246]

[0247] result:

[0248] Stability of the test composition

[0249] The average droplet size and maximum droplet size results determined at the time of manufacture of the test compositions and over a period ranging from 1 to 6 months are collated in Table 5 below:

[0250] [Table 5]

[0251]

[0252] The results show that the mean droplet size (μm) and the maximum droplet size of the composition according to the invention (composition B2) are smaller than those of comparative compositions A4 and A5 not comprising such a mixture of organic peroxides.

[0253] Embodiment 3:

[0254] Composition A6 and composition A7 were prepared according to a procedure similar to that described in Example 1. Composition A6 corresponds to bis(2-ethylhexyl) peroxydicarbonate ( 223), composition A7 corresponds to 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate ( 610) aqueous emulsion.

[0255] Composition B3 was prepared by mixing 73% by weight of composition A6 and 27% by weight of composition A7 with each other to obtain a weight ratio of 80 / 20.

[0256] Composition B4 was prepared by mixing 65% by weight of composition A6 and 35% by weight of composition A7 with each other to obtain a weight ratio of 80 / 20.

[0257] Composition B5 was prepared by mixing bis(2-ethylhexyl) peroxydicarbonate and 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate in a weight ratio of 80 / 20 added to the aqueous phase according to the procedure described in Example 1 .

[0258] Composition B6 was prepared by mixing bis(2-ethylhexyl) peroxydicarbonate and 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate in a weight ratio of 70 / 30 added to the aqueous phase according to the procedure described in Example 1 .

[0259] Compositions A6, A7, B3, B4, B5 and B6 are described in Tables 6-8 below.

[0260] Composition:

[0261] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of compositions A6 and A7 in Table 6 below:

[0262] [Table 6]

[0263]

[0264] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B3 in Table 7 below:

[0265] [Table 7]

[0266]

[0267]

[0268] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B4 in Table 8 below:

[0269] [Table 8]

[0270]

[0271] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B5 in Table 9 below:

[0272] [Table 9]

[0273]

[0274] The amounts of the following ingredients are expressed as weight percentages relative to the total weight of composition B6 in Table 10 below:

[0275] [Table 10]

[0276]

[0277]

[0278] result:

[0279] Stability of the test composition

[0280] The average droplet size and maximum droplet size results measured at the time of manufacture of the test compositions and over a period ranging from 1 to 6 months are collated in Table 11 below:

[0281] [Table 11]

[0282]

[0283] The results show that the average droplet size (μm) and the maximum droplet size of the compositions according to the invention (compositions B3 to B6) are smaller than those of comparative compositions A6 and A7 not comprising such a mixture of organic peroxides.

Claims

1. An aqueous emulsion composition comprising: - one or more organic peroxides of formula (I): In the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 an alkyl group which may contain one or more heteroatoms; - one or more organic peroxides of formula (II): In the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 an alkyl group which may contain one or more heteroatoms and / or be optionally substituted with one or more hydroxyl groups; The organic peroxide of formula (I) and the organic peroxide of formula (II) are present in a concentration ranging from 40% to 70% by weight relative to the total weight of the composition.

2. The composition as claimed in claim 1, characterized in that in the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may contain one or more oxygen atoms.

3. The composition as claimed in claim 1, characterized in that in the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may be interrupted by one or more heteroatoms.

4. The composition as claimed in claim 3, characterized in that in the formula (I), R 1 and R 2 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may be interrupted by one or more oxygen atoms.

5. The composition as claimed in claim 1, characterized in that in the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may contain one or more oxygen atoms.

6. The composition as claimed in claim 1, characterized in that in the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may be interrupted by one or more heteroatoms.

7. The composition as claimed in claim 6, characterized in that in the formula (II), R 3 and R 4 may be the same or different, representing a linear, branched or cyclic C1-C 20 An alkyl group which may be interrupted by one or more oxygen atoms.

8. A composition as claimed in claim 1, characterized in that the organic peroxide of formula (I) and the organic peroxide of formula (II) are present in a concentration ranging from 40% to 65% by weight, relative to the total weight of the composition.

9. A composition as claimed in claim 8, characterised in that the organic peroxide of formula (I) and the organic peroxide of formula (II) are present in a concentration ranging from 40% to 60% by weight relative to the total weight of the composition.

10. The composition as claimed in claim 1, characterized in that R 1 and R 2 Can be the same or different, representing a linear or branched C1-C 16 An alkyl group which may contain one or more heteroatoms.

11. A composition as claimed in claim 10, characterized in that R 1 and R 2 Can be the same or different, representing a linear or branched C3-C 12 Alkyl group.

12. A composition as claimed in claim 11, characterized in that R 1 and R 2 Can be the same or different, representing a linear or branched C3-C 10 Alkyl group.

13. The composition as claimed in claim 10, characterized in that the one or more heteroatoms are one or more oxygen atoms.

14. A composition as claimed in claim 1, characterized in that R 1 and R 2 The same and represents a linear or branched C1-C 16 Alkyl group.

15. A composition as claimed in claim 14, characterized in that R 1 and R 2 The same and represents a branched C1-C 16 Alkyl group.

16. A composition as claimed in claim 14, characterized in that R 1 and R 2 The same and represents a linear or branched C3-C 12 Alkyl group.

17. A composition as claimed in claim 16, characterized in that R 1 and R 2 The same and represents a linear or branched C3-C 10 Alkyl group.

18. A composition as claimed in any one of claims 1 to 17, characterised in that the peroxide of formula (I) is chosen from bis(2-ethylhexyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, bis(1-methylheptyl) peroxydicarbonate, di(n-propyl) peroxydicarbonate, bis(3-methoxybutyl) peroxydicarbonate, diethyl peroxycarbonate, and mixtures thereof.

19. A composition as claimed in claim 18, characterised in that the peroxide of formula (I) is chosen from bis(2-ethylhexyl) peroxydicarbonate and di(sec-butyl) peroxydicarbonate.

20. A composition as claimed in any one of claims 1 to 17, characterised in that: -R 3 Indicates a linear, branched or cyclic C7-C 20 an alkyl group, which may contain one or more oxygen atoms; -R4 means: i) Linear or branched C7-C 20 an alkyl group, which may contain one or more oxygen atoms; ii) a linear or branched C1-C7 alkyl group, which is optionally substituted by one or more hydroxyl groups, iii) Cyclic C7-C 10 Alkyl group.

21. A composition as claimed in claim 20, characterized in that R 3 Indicates branched C7-C 20 Alkyl group.

22. The composition as claimed in claim 20, characterized in that R 3 Indicates a linear, branched or cyclic C7-C 16 Alkyl group.

23. A composition as claimed in claim 22, characterized in that R 3 Indicates a linear, branched or cyclic C7-C 10 Alkyl group.

24. The composition as claimed in claim 20, characterized in that R 3 Indicates a linear, branched or cyclic C7-C 20 An alkyl group which may contain one oxygen atom.

25. The composition as claimed in claim 20, characterized in that R 3 Indicates a linear, branched or cyclic C7-C 20 An alkyl group which may be interrupted by one or more oxygen atoms.

26. A composition as claimed in claim 25, characterized in that R 3 Indicates a linear, branched or cyclic C7-C 20 An alkyl group which may be interrupted by an oxygen atom.

27. A composition as claimed in claim 20, characterised in that R4 represents i) a branched C7-C 20 Alkyl group.

28. A composition as claimed in claim 20, characterised in that R4 represents i) a linear or branched C7-C 16 Alkyl group.

29. A composition as claimed in claim 28, characterised in that R4 represents i) a linear or branched C7-C 10 Alkyl group.

30. The composition as claimed in claim 20, characterized in that R4 represents i) a linear or branched C7-C 20 An alkyl group which may contain one oxygen atom.

31. A composition as claimed in claim 20, characterized in that R4 represents i) a linear or branched C7-C 20 An alkyl group which may be interrupted by one or more oxygen atoms.

32. A composition as claimed in claim 31, characterised in that R4 represents i) a linear or branched C7-C 20 An alkyl group which may be interrupted by an oxygen atom.

33. A composition as claimed in claim 20, characterised in that R4 represents ii) a branched C1-C7 alkyl group.

34. A composition as claimed in claim 20, characterised in that R4 represents ii) a linear or branched C2-C7 alkyl group.

35. A composition as claimed in claim 20, characterised in that R4 represents iii) a cyclic C9 alkyl group.

36. A composition as claimed in any one of claims 1 to 17, characterised in that the peroxide of formula (II) is selected from the group consisting of α-cumyl peroxyneodecanoate, α-cumyl peroxyneoheptanoate, 2,4,4-trimethylpentan-2-yl peroxyneodecanoate, tert-butyl peroxy(n-heptanoate), tert-butyl peroxyneodecanoate, α-cumyl peroxy(n-heptanoate), tert-amyl peroxy(n-heptanoate), tert-butyl peroxyneodecanoate, 2,5-dimethyl-2,5- Bis(2-ethylhexanoylperoxy)hexane, tert-amyl peroxy(2-ethylhexanoate), tert-butyl peroxy(2-ethylhexanoate), 1,1,3,3-tetramethylbutyl peroxy(2-ethylhexanoate), hydroxyperoxyesters, tert-amyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-hexyl peroxyneodecanoate, tert-hexyl peroxypivalate, and mixtures thereof.

37. A composition as claimed in any one of claims 1 to 17, characterised in that the peroxide of formula (II) is chosen from hydroxyperoxyesters selected from 4-hydroxy-2-methylpentyl peroxyneodecanoate, 4-hydroxy-2-methylpentyl peroxyneoheptanoate, 4-hydroxy-2-methylpentyl peroxy(2-ethylhexanoate), 4-hydroxy-2-methylpentyl peroxy(2-phenylbutyrate), 4-hydroxy-2-methylpentyl peroxy(2-phenoxypropionate), 4-hydroxy-2-methylpentyl peroxy(2-butyloctanoate), 4-hydroxy-2-methylpentyl peroxyneohexanoate, 4-hydroxy-2-methylpentyl peroxyneotridecanoate, 4-hydroxy-2-methylpentyl peroxyneotridecanoate. -hydroxy-2-methylpentyl ester, 4-hydroxy-2-methylhexyl peroxyneohexanoate, 4-hydroxy-2-methylhexyl peroxyneodecanoate, 5-hydroxy-1,3,3-trimethylcyclohexyl peroxyneodecanoate, 4-hydroxy-2,6-dimethyl-2,6-di(neohexanoylperoxy)heptane, 4-hydroxy-2,6-dimethyl-2,6-di(neodecanoylperoxy)heptane, 3-hydroxy-1,1-dimethylbutyl peroxy(2-ethylhexanoate), 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, 3-hydroxy-1,1-dimethylbutyl peroxyneoheptanoate, and mixtures thereof.

38. A composition as claimed in claim 37, characterised in that the peroxide of formula (II) is chosen from 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate.

39. A composition as claimed in any one of claims 1 to 17, characterised in that the weight ratio of organic peroxide of formula (I) / peroxide of formula (II) ranges from 99 / 1 to 50 / 50.

40. A composition as claimed in claim 39, characterised in that the weight ratio of organic peroxide of formula (I) / peroxide of formula (II) ranges from 97 / 3 to 50 / 50.

41. A composition as claimed in claim 40, characterised in that the weight ratio of organic peroxide of formula (I) / peroxide of formula (II) ranges from 90 / 10 to 50 / 50.

42. A composition as claimed in claim 41, characterised in that the weight ratio of organic peroxide of formula (I) / peroxide of formula (II) ranges from 80 / 20 to 50 / 50.

43. A composition as claimed in any one of claims 1 to 17, characterised in that it also comprises one or more antifreeze agents.

44. Composition as claimed in any one of claims 1 to 17, characterised in that it contains ethanol or methanol in a content of less than 10% by weight.

45. A composition as claimed in any one of claims 1 to 17, characterised in that it comprises one or more emulsifiers.

46. ​​A composition as claimed in any one of claims 1 to 17, characterised in that the average organic peroxide droplet size is less than 10 μm and the maximum droplet size is less than 20 μm.

47. A composition as claimed in claim 46, characterised in that the average organic peroxide droplet size is less than 5 μm.

48. A composition as claimed in claim 46, characterised in that the maximum droplet size is less than 15 μm.

49. A process for preparing a composition as defined in any one of claims 1 to 48, characterised in that the process involves, in sequence: (i) Mix the following: (a) at least one organic peroxide of formula (I) as defined in any one of claims 1 to 19, (b) at least one organic peroxide of formula (II) as defined in any one of claims 1 to 9 and 20 to 38, (ii) optionally emulsifying the mixture.

50. Use of a composition as defined in any one of claims 1 to 48 for the polymerisation or copolymerisation of one or more ethylenically unsaturated monomers.

51. The use as claimed in claim 50, characterized in that The one or more ethylenically unsaturated monomers are one or more halogenated vinyl monomers.

52. The use as claimed in claim 51, characterized in that The one or more ethylenically unsaturated monomers is vinyl chloride.

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