CN117120483A

CN117120483A - Composition comprising at least one aromatic peroxide and at least hydrogen peroxide

Info

Publication number: CN117120483A
Application number: CN202280026917.1A
Authority: CN
Inventors: B·范赫梅尔里克; 陈慧; S·哈伯
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2021-04-07
Filing date: 2022-04-07
Publication date: 2023-11-24
Also published as: CN117098752A; CN117177956A; FR3121682A1

Abstract

The present invention relates to a composition comprising at least one aromatic peroxide comprising at least one aromatic ring and at least one peroxy function in its structure, as defined below, and at least hydrogen peroxide.

Description

Composition comprising at least one aromatic peroxide and at least hydrogen peroxide

Technical Field

The invention also relates to the use of said composition for the preparation of polymers, preferably styrenic polymers, or polymer resins, in particular polymer ester resins, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins, and vinyl ester resins.

The invention also relates to the use of at least hydrogen peroxide for improving the color stability of a composition comprising at least one aromatic peroxide having at least one aromatic ring and at least one peroxy function in its structure, as defined below.

Background

Aromatic peroxides are currently used as free radical initiators in various polymerization reactions, for example for the synthesis of styrenic resins, vinyl ester resins or polyacrylates, for example poly (meth) acrylates with side-chain aromatic rings, or as curing agents for the preparation of thermosetting polyesters, i.e. unsaturated polyester resins, which can be used for the manufacture of artificial marble products, gel coats, marine vessels (marine watercraft), polymer concretes, etc.

Aromatic peroxides are well known commercially and may be selected from the family of aromatic peresters, i.e. perbenzoates, e.g. under the nameP is sold as t-butyl peroxybenzoate (denoted TBPB), aryl peralkylates and aromatic diperoxates, aryl alkyl peroxide families such as dicumyl peroxide, aryl hydroperoxide families such as cumene hydroperoxide, and aromatic diacyl peroxide families such as bis (2, 4-dichlorobenzoyl) peroxide.

However, one of the major drawbacks of the above aromatic peroxides is that they generally undergo a color transition at room temperature or after a period of time under standard storage conditions at recommended storage temperature conditions (i.e. between 8 and 30 ℃). In particular, it has been pointed out that the color of the aromatic peroxides sometimes steadily increases or even increases sharply (soar) over a relatively short period of time, for example the color of t-butyl peroxybenzoate may suddenly increase over a period of 21 days during their storage. The above aromatic peroxides are said to experience color stability problems during their storage, even in the dark.

Thus, such color stability problems can reduce the shelf life of aromatic peroxides, sometimes forcing manufacturers of target polymer resins to use them earlier than expected before they produce a significant and irreversible color change. In practice, there may be the following risks: the colored impurities of aromatic peroxides color the polymer or polymer resin during its preparation, which may be a related problem depending on its design application.

In particular, the production of polymers or polymer resins that are unintentionally colored due to the coloration provided by the polymer peroxide may be easily misinterpreted by some users as meaning that the polymer or polymer resin is of poor quality. As an example, it may be assumed that the resulting polymers or polymer resins have undergone photo-oxidation or photo-degradation, which changes their natural appearance and properties.

More broadly, the lack of color stability of the aromatic peroxide during storage can affect the appearance of the target polymeric compound (polymeric compound ) and change the overall appearance of the final product. It may also lead to misunderstanding of the quality of the polymeric compounds and the products obtained therefrom.

Furthermore, such coloring may make the manufacture of polymeric compounds which are believed to have specific light-colored characteristics required (impose) by their industrial application, such as LDPE blister (blister) applications, more difficult.

Furthermore, in some cases, this coloring can make the subsequent addition of dyes designed to impart a specific color to the final appearance of the polymeric compound more cumbersome. Indeed, the polymeric compounds produced can sometimes exhibit color due to aromatic peroxides, which does not match the dyes that need to be added.

Thus, the risk of transferring the color of the above aromatic peroxides may represent an obstacle to the economic value of the polymers and polymer resins produced from a commercial point of view.

Development of color in compositions comprising aromatic peroxides can also interfere with the final presence of colored dyes that have been intentionally added to the composition (e.g., as a visual aid to assist an operator during the course thereof).

Thus, there remains a real need to provide compositions comprising aromatic peroxides that are capable of being color stable over time under recommended storage conditions to mitigate the risk of color transfer to the target polymeric compound detailed previously.

In particular, it is an object of the present invention to minimize the development of color (color development) of aromatic peroxides during storage, in particular at room temperature, in order to be able to use them effectively for the manufacture of said polymeric compounds without negatively affecting their appearance.

More specifically, it is another object of the present invention to inhibit the increase in color of aromatic peroxides during their storage.

Disclosure of Invention

The present invention is the result of the unexpected discovery by the present inventors that the use of at least hydrogen peroxide is capable of improving the color stability over time (i.e. inhibiting the color evolution of the aromatic peroxide) of at least one aromatic peroxide as defined below, and of reducing the coloration due to the aromatic peroxide.

Accordingly, the present invention relates to a composition comprising:

a) At least one aromatic peroxide comprising at least one aromatic ring and at least one peroxy-O-functional group in its structure; preferably, the aromatic ring is attached to the peroxy function by a covalent bond, a carbonyl group or an alkyl group comprising 1 to 20 carbon atoms;

the aromatic peroxide is present in the composition in a concentration ranging from 30% to 99.9% by weight, relative to the total weight of the composition,

b) At least hydrogen peroxide, preferably in a concentration ranging from 0.1 to 10% by weight, the weight ratio of hydrogen peroxide to aromatic peroxide relative to the total weight of the composition is preferably between 1:20000 and 1:40, more preferably between 1:2000 and 1:50, even more preferably between 1:800 and 1:80.

The compositions of the invention exhibit better color stability under standard storage conditions, particularly at room temperature, and particularly in the dark, than compositions comprising only the aromatic peroxides described above.

In more detail, the composition according to the invention exhibits a significantly lower APHA color value than the same composition comprising the aromatic peroxide described above under standard storage conditions, in particular at room temperature, and in particular in the dark, over a period of at least 5 days, in particular at least 15 days, in particular at least 20 days, preferably at least 30 days, more preferably at least 50 days, and even more particularly at least 90 days.

According to the invention, the expression "room temperature" means a temperature range from 0 ℃ to 50 ℃, preferably from 10 ℃ to 40 ℃, more preferably from 15 ℃ to 30 ℃, even more preferably from 20 ℃ to 30 ℃.

According to the invention, the expression "in the dark" means to protect the composition from light, in particular from Ultraviolet (UV) radiation.

According to the invention, APHA color is named by the american public health association (American Public Health Association)) and is defined by the color standard defined by standard ASTM D1209 and more precisely ASTM D1209-05 (2011). The APHA color is a color scale (scale), sometimes also referred to as "yellow index", that allows the quality of samples with light to yellowish colors to be assessed. APHA color was measured using a colorimeter with a standard range of 0 to 1000APHA.

The color of the composition according to the invention can be assessed by a spectrocolorimeter, for example the spectrocolorimeter sold under the name LICO 620 by Hach company.

In other words, the addition of at least hydrogen peroxide can reduce or stabilize the APHA color value of the above aromatic peroxides.

The color stability of the composition of the present invention helps to minimize the risk of: aromatic peroxides give undesirable coloration (color) to the target polymeric compound due to their storage time.

Thus, the compositions of the present invention can be effectively used to prepare polymers, particularly polystyrene or polymer resins, preferably polymer ester resins, without altering their appearance, i.e., without inadvertently coloring them.

More precisely, the use of at least hydrogen peroxide enables a significant inhibition of the color evolution of aromatic peroxides over time, in particular at room temperature.

This also means that the addition of at least hydrogen peroxide can extend the use time of the aromatic peroxide in applications, in particular at room temperature.

Thus, the use of at least hydrogen peroxide is able to restore the economic value of aromatic peroxides, as they can be stored under standard conditions for extended periods of time without experiencing significant and unacceptable coloration.

The invention also relates to a process for preparing the above composition, comprising mixing at least one aromatic peroxide as defined previously with at least hydrogen peroxide.

As previously mentioned, the compositions exhibit enhanced color stability.

The invention also relates to the use of a composition as defined hereinbefore for the preparation of a polymer, preferably a styrenic polymer, or a polymer resin, in particular a polymer ester resin, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins, more preferably from unsaturated polyester resins and vinyl ester resins.

In detail, the composition of the present invention can be effectively used for polymerization of styrenic polymers, vinyl ester resins or poly (meth) acrylates, or as a curing agent for preparing thermosetting polyesters, i.e., unsaturated polyester resins.

Another aspect of the invention is the use of at least hydrogen peroxide for improving the color stability of at least one aromatic peroxide, in particular at room temperature.

Preferably, one of the aspects of the present invention is the use of at least hydrogen peroxide to inhibit the color evolution of aromatic peroxides.

Other subject matter and features, aspects, and advantages of the present invention will become more apparent upon reading the following description and examples.

In the text below, unless otherwise indicated, limitations of the range of values are included within the range, particularly in the expressions "between … and …" and "range … to …".

Furthermore, the expression "at least one" as used in this specification is equivalent to the expression "one or more".

The term "polymerization" includes homo-and copolymerization of one or more unsaturated monomers involved.

As contemplated herein, the term "comprising" has the meaning of "including" or "containing," which means that when an object "comprises" one or several elements, other elements than those mentioned may also be included in the object. In contrast, when an object is referred to as being "composed of" one or more elements, the object is limited to the listed elements and cannot include other elements in addition to the mentioned elements.

Drawings

FIG. 1 shows the results of measurement of APHA values with respect to time in the dark at a temperature of 40℃for compositions A-B shown in Table 1.

FIG. 2 shows the results of measurements of APHA of compositions A-B shown in Table 1 with respect to time in the dark at 25 ℃.

FIG. 3 shows the results of measurements of APHA values versus time for compositions A1-C1 shown in Table 2 at 40℃in the dark.

FIG. 4 shows the inclusion measured at a temperature of 40℃and in the darkAPHA value versus time for a composition of P and 1 wt% hydrogen peroxide.

Detailed Description

Composition and method for producing the same

As previously detailed, the composition according to the invention comprises:

b) At least hydrogen peroxide in a concentration of 0.1 to 10 wt.%, relative to the total weight of the composition.

Preferably, the weight ratio of hydrogen peroxide to aromatic peroxide is between 1:20000 and 1:40, more preferably between 1:2000 and 1:50, even more preferably between 1:800 and 1:80.

Preferably, the composition of the present invention is a curing composition (curing composition ) or a composition for initiating free radical polymerization. In other words, the composition of the invention preferably does not contain any monomers and/or polymers to be cured and/or polymerized.

Aromatic peroxides

The aromatic ring of the aromatic peroxide may be substituted with: linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ Alkyl, and/or one or more halogen atoms, preferably linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ An alkyl group.

Preferably, the aromatic peroxide comprises at least one benzene ring. The benzene ring is preferably attached to the peroxy function by: covalent bond, carbonyl (-C (=o) -) or alkyl containing 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 2 carbon atoms, even more preferably 1 carbon atom.

Preferably, the aromatic peroxide comprises at least one benzene ring and at least one peroxy-O-functional group in its structure; the benzene ring is attached to the peroxy function through no more than two carbon atoms, even more preferably no more than one carbon atom.

According to the present invention, the expression "the benzene ring is linked to said peroxy function through no more than two carbon atoms" means that the benzene ring is linked to the-O-function of the alkyl peroxide through a covalent bond, a carbonyl group or an aromatic group (alkyl group comprising two carbon atoms) containing no more than two carbon atoms.

According to the present invention, the expression "the benzene ring is attached to said peroxy function through no more than one carbon atom" means that the benzene ring is attached to the-O-function of the alkyl peroxide through a covalent bond, a carbonyl group or an alkyl group not comprising more than one carbon atom (comprising one carbon atom).

Preferably, the aromatic peroxide comprises at least one benzene ring and at least one peroxy-O-functional group in its structure; the benzene ring is attached to the peroxy function by a covalent bond, a carbonyl group or an alkyl group comprising 1 to 2 carbon atoms, even more preferably 1 carbon atom; c with benzene rings optionally linear or branched ₁ -C ₁₀ Alkyl groups, especially C ₁ -C ₄ An alkyl group, and/or one or more halogen atoms.

Preferably, the aromatic peroxide as defined above is liquid at room temperature.

The aromatic peroxide may be selected from aromatic peresters, aryl-alkyl peroxides, aryl hydroperoxides, aromatic diacyl peroxides, and mixtures thereof.

Preferably, the aromatic peroxide may be selected from aromatic peresters.

Preferably, the aromatic peroxide comprises at least one benzene ring and at least one peroxy-O-functional group in its structure; the benzene ring is attached to the peroxy function by a covalent bond, a carbonyl group or an alkyl group comprising 1 to 2 carbon atoms, even more preferably 1 carbon atom; the benzene rings optionally being linear or branched C ₁ -C ₄ Alkyl and/or oneOr a plurality of halogen atoms; the aromatic compound is selected from the group consisting of aromatic peresters, arylalkyl peroxides, aryl hydroperoxides, aromatic diacyl peroxides, and mixtures thereof; in particular aromatic peresters.

The aromatic peroxide selected from aromatic peresters is preferably selected from perbenzoates, aryl peralkylates, aromatic diperoxates and mixtures thereof.

Advantageously, the aromatic peroxide is selected from perbenzoates.

Preferably, the aromatic peroxide has the following formula (I):

R ₁ -O-O-R ₂

(I)

wherein the method comprises the steps of

·R ₁ The representation is:

--C(＝O)R’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or an aryl group having 3 to 30 carbon atoms substituted by one or more halogen atoms, or

Linear or branched C blocked with aryl groups having 3 to 30 carbon atoms ₁ -C ₂₀ Alkyl, optionally linear or branched C ₁ -C ₁₀ Alkyl and/or one or more halogen atoms;

--CR’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or one or more halogen atom substituted aryl groups having 6 to 32 carbon atoms;

·R ₂ the representation is:

linear or branched C ₁ -C ₂₀ An alkyl group, a hydroxyl group,

c optionally linear or branched ₁ -C ₁₀ An alkyl group and/or one or more halogen atom substituted aryl groups having 3 to 30 carbon atoms,

--R ₃ OOR ₄ a group, wherein R is ₃ C representing a linear or branched chain ₈ -C ₂₀ Alkyl groups, preferably C ₈ -C ₁₀ An alkyl group, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents aryl radicals having 3 to 30 carbon atoms, which are optionally linear or branched C ₁ -C ₁₀ Alkyl groups and/or one or more halogen atoms,

linear or branched C blocked with aryl groups having 3 to 30 carbon atoms ₁ -C ₂₀ Alkyl, optionally linear or branched C ₁ -C ₁₀ Alkyl and/or one or more halogen atoms,

--C(＝O)R’ ₂ a group wherein R' ₂ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or an aryl group having 3 to 30 carbon atoms substituted by one or more halogen atoms, or

-a hydrogen atom.

Preferably, the aromatic peroxide has the following formula (I):

R ₁ -O-O-R ₂

(I)

Wherein:

·R ₁ the representation is:

--C(＝O)R’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ Phenyl ring substituted by alkyl and/or by one or more halogen atoms, preferably chlorine atoms, or

Linear or branched C terminated with benzene rings ₁ -C ₂₀ Benzene, optionally linear or branched C ₁ -C ₁₀ Alkyl and/or one or more halogen atoms, preferably chlorine atoms;

·R ₂ the representation is:

linear or branched C ₁ -C ₂₀ An alkyl group, a hydroxyl group,

-a benzene ring, optionally linear or branched C ₁ -C ₁₀ Alkyl and/or one or more halogen atoms, preferably chlorine atoms,

--R ₃ OOR ₄ a group, wherein R is ₃ C representing a linear or branched chain ₈ -C ₂₀ Alkyl groups, preferably C ₈ -C ₁₀ An alkyl group, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or a benzene ring substituted by one or more halogen atoms,

with optionally linear or branched C ₁ -C ₁₀ Linear or branched C capped with benzene rings substituted with alkyl groups and/or one or more halogen atoms ₁ -C ₂₀ An alkyl group, a hydroxyl group,

--C(＝O)R’ ₂ a group wherein R' ₂ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or a benzene ring substituted by one or more halogen atoms, preferably chlorine atoms,

-a hydrogen atom.

Preferably, R ₁ The representation is:

--C(＝O)R’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ Phenyl ring substituted by alkyl groups and/or by one or more halogen atoms, preferably chlorine atoms, or

Linear or branched C ₁ -C ₁₀ Alkyl, preferably branched C ₁ -C ₁₀ Alkyl, which is terminated with a benzene ring, optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ Halogen, and/or one or more halogen atoms, preferably chlorine atoms.

Preferably, R ₂ The representation is:

linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₅ Alkyl, more preferably branched C ₁ -C ₅ An alkyl group, a hydroxyl group,

benzene rings optionally linear or branched C ₁ -C ₁₀ Alkyl, especially linear or branched C ₁ -C ₄ Alkyl and/or one or more halogen atoms, preferably chlorine atoms,

--R ₃ OOR ₄ a group, wherein R is ₃ Representing line typeOr branched C ₈ -C ₂₀ Alkyl, preferably C ₈ -C ₁₀ Alkyl, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ Alkyl, and/or benzene rings substituted by one or more halogen atoms, preferably chlorine atoms,

linear or branched C ₁ -C ₁₀ Alkyl, preferably branched C ₁ -C ₁₀ Alkyl, optionally linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ Alkyl, and/or one or more halogen atoms, preferably chlorine atom substituted benzene rings,

--C(＝O)R’ ₂ A group wherein R' ₂ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ An alkyl group and/or a benzene ring substituted by one or more halogen atoms, preferably chlorine atoms,

-a hydrogen atom.

Preferably, in formula (I):

·R ₁ the representation is:

Linear or branched C ₁ -C ₁₀ Alkyl, preferably branched C ₁ -C ₁₀ Alkyl, which is terminated with a benzene ring, optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ Halogen, and/or one or more halogen atoms, preferably chlorine atoms,

·R ₂ the representation is:

--R ₃ OOR ₄ a group, wherein R is ₃ C representing a linear or branched chain ₈ -C ₂₀ Alkyl, preferably C ₈ -C ₁₀ Alkyl, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ Alkyl, and/or benzene ring substituted by one or more halogen atoms,

Linear or branched C ₁ -C ₁₀ Alkyl, preferably branched C ₁ -C ₁₀ Alkyl, which is terminated with a benzene ring as follows: the benzene ring optionally being linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ An alkyl group, and/or a benzene ring end-capping of one or more halogen atoms, preferably chlorine atoms,

-a hydrogen atom.

Preferably, the aromatic peroxide has the following formula (I):

R ₁ -O-O-R ₂

(I)

wherein:

·R ₁ the representation is:

--C(＝O)R’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ An alkyl group and/or a benzene ring substituted by one or more halogen atoms, preferably chlorine atoms,

·R ₂ the representation is:

-a benzene ring as follows: the benzene ring optionally being linear or branched C ₁ -C ₁₀ Alkyl, especially linear or branched C ₁ -C ₄ Alkyl, even more preferably branched C ₁ -C ₄ Alkyl, and/or benzene rings substituted by one or more halogen atoms, preferably chlorine atoms,

--R ₃ OOR ₄ a group, wherein R is ₃ C representing a linear or branched chain ₈ -C ₂₀ Alkyl, preferably C ₈ -C ₁₀ Alkyl, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₄ Alkyl, and/or benzene rings substituted by one or more halogen atoms, preferably chlorine atoms,

--C(＝O)R’ ₂ a group wherein R' ₂ Represents optionally linear or branched C ₁ -C ₁₀ Alkyl, preferably C ₁ -C ₄ An alkyl group and/or a benzene ring substituted by one or more halogen atoms, preferably chlorine atoms.

Preferably, the aromatic peroxide has the following formula (I):

R ₁ -O-O-R ₂

(I)

wherein:

·R ₁ the representation is:

·R ₂ the representation is:

linear or branched C ₁ -C ₁₀ Alkyl, especially C ₁ -C ₅ Alkyl, more preferably branched C ₁ -C ₅ An alkyl group.

Preferably aromaticThe peroxide is selected from: tert-butyl-peroxybenzoate, e.g. by the nameP is sold, for example under the name +.>288, such as cumyl peroxyneodecanoate under the name +.>188, 2, 5-dimethyl-2, 5- (dibenzoylperoxy) hexane, e.g. +.>118, tert-butylcumyl peroxide, e.g. under the name +.>801 dicumyl peroxide, e.g. under the name +.>Cumene hydroperoxide of the type sold under the name DCP>Of the type sold by CU80, bis (2, 4-dichlorobenzoyl) peroxide, e.g. under the name +. >DCBP is sold as 1,3, 4-bis (tert-butylperoxyisopropyl) benzene, e.g. under the name +.>F, t-amyl peroxybenzoate, e.g. +.>TAP, and mixtures thereof.

Preferably, the aromatic peroxide is selected from: tert-butyl peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoyl peroxy) hexane, tert-amyl peroxybenzoate, and mixtures thereof.

Advantageously, the aromatic peroxide is t-butyl peroxybenzoate.

Preferably, the aromatic peroxide is present in the composition in a concentration ranging from 30% to 99.9% by weight, preferably ranging from 70% to 99.9% by weight, more preferably ranging from 90% to 99.9% by weight, relative to the total weight of the composition.

In particular, the aromatic peroxide is t-butyl peroxybenzoate and is present at a concentration ranging from 30 wt% to 99.9 wt%, preferably ranging from 70 wt% to 99.9 wt%, more preferably ranging from 90 wt% to 99.9 wt%, relative to the total weight of the composition.

In an integrated embodiment, the composition of the invention does not comprise other aromatic peroxides than the aromatic peroxides as defined above.

₂ ₂ Hydrogen peroxide (HO)

The composition according to the invention further comprises hydrogen peroxide (H ₂ O ₂ )。

The hydrogen peroxide may preferably be present in the composition according to the invention in a concentration ranging from 0.005 to 10 wt%, preferably from 0.005 to 5 wt%, preferably from 0.005 to 1.5 wt%, more preferably from 0.05 to 1.5 wt%, more preferably from 0.1 to 1.5 wt%, and even more preferably from 0.1 to 1.2 wt%, relative to the total weight of the composition.

Preferably, the weight ratio of hydrogen peroxide to aromatic peroxide as defined above is between 1:20000 and 1:40, more preferably between 1:2000 and 1:50, even more preferably between 1:800 and 1:80.

Ketone peroxides

The composition of the present invention may further comprise at least one ketone peroxide.

As contemplated herein, "ketone peroxide" refers to an organic compound comprising at least one peroxide functional group (-OOH).

Preferably, the ketone peroxide as defined above is liquid at room temperature.

The ketone peroxide is preferably selected from: methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, 2, 4-pentanedione peroxide, and mixtures thereof, even more preferably methyl ethyl ketone peroxide and methyl isobutyl ketone peroxide.

Preferably, the ketone peroxide according to the invention has the following formula (II):

(II)R ₃ CR ₄ (OOH) ₂

wherein R is ₃ And R is ₄ ：

-independently of each other represent linear or branched C ₁ -C ₂₀ Alkyl, or

Together forming a substituted or unsubstituted cyclic group, preferably C ₄ -C ₆ A cyclic group.

According to a specific embodiment, the ketone peroxide may be in the form: dimer (having formula (III) R ₃ R ₄ C(OOH)OOC(OOH)R ₃ R ₄ ，R ₃ And R is ₄ As defined above), or a trimer (having formula (IV) R ₃ R ₄ C(OOH)OOCR ₃ R ₄ 0OC(OOH)R ₃ R ₄ ，R ₃ And R is ₄ As defined above), dimers are preferred.

Advantageously, the ketone peroxide is selected from methyl ethyl ketone peroxides, e.g. under the nameK1-sold methyl ethyl ketone peroxide, and methyl isobutyl ketone peroxide, for example under the name +.>Methyl isobutyl ketone peroxide sold as K2.

Preferably, the ketone peroxide is present in the composition in a concentration ranging from 0.1% to 30% by weight, in particular ranging from 1% to 29% by weight, preferably ranging from 2% to 25% by weight, more preferably ranging from 4% to 20% by weight, even more preferably ranging from 5% to 10% by weight, relative to the total weight of the composition.

In particular, the ketone peroxide is methyl ethyl ketone peroxide and is present in the composition in a concentration ranging from 0.1% to 30% by weight, in particular ranging from 1% to 29% by weight, preferably ranging from 2% to 25% by weight, more preferably ranging from 4% to 20% by weight, even more preferably ranging from 5% to 10% by weight, relative to the total weight of the composition.

Preferably, the weight ratio between aromatic peroxide and ketone peroxide is from 0.001 to 1, preferably from 0.01 to 0.5, even more preferably from 0.05 to 0.1.

Solvent(s)

The composition may further comprise at least one solvent. The solvent according to the invention may be of any type known to the person skilled in the art suitable for solvating organic peroxides, in particular aromatic peroxides.

In particular, the presence of a solvent may help promote uniformity (homogeneity) of the compositions of the present invention.

Preferably, the solvent according to the present invention is an organic solvent selected from the group consisting of ketone solvents, aryl solvents, ether solvents, alcohol solvents, mineral oils and hydrocarbon solvents.

Advantageously, the solvent is an organic solvent selected from ketone solvents and alcohol solvents, preferably alcohol solvents.

More preferably, the solvent is selected from the group consisting of dimethyl phthalate, dimethyl terephthalate, methyl isobutyl ketone, cyclohexanone, ethyl acetate, isododecane, glycol ethers, ethylene glycol, isopropanol, or combinations thereof. More preferably, the solvent is isopropanol.

Within the meaning of the present invention, it is to be understood that glycol ethers are different from the additives having ether groups as defined below.

Preferably, the composition according to the invention comprises:

a) At least one aromatic peroxide as defined previously,

b) At least hydrogen peroxide, preferably present in a concentration ranging from 0.005 to 10 wt%, preferably from 0.005 to 5 wt%, preferably from 0.005 to 1.5 wt%, more preferably from 0.05 to 1.5 wt%, more preferably from 0.1 to 1.5 wt%, and even more preferably from 0.1 to 1.2 wt%, relative to the total weight of the composition,

c) At least one solvent, preferably selected from the group consisting of ketone solvents, aryl solvents, ether solvents, alcohol solvents, mineral oils and hydrocarbon solvents.

Preferably, the composition according to the invention comprises:

a) At least one aromatic peroxide selected from the group consisting of: tert-butyl-peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoylperoxy) hexane, tert-butyl cumyl peroxide, dicumyl peroxide, cumene hydroperoxide, bis (2, 4-dichlorobenzoyl) peroxide, and mixtures thereof, preferably tert-butyl-peroxybenzoate

c) At least one solvent, preferably selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, t-butanol, ethanol, methanol, isopropanol, and mixtures thereof.

Preferably, the composition according to the invention comprises:

a) At least one aromatic peroxide selected from the group consisting of t-butyl-peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoyl peroxy) hexane, and mixtures thereof, preferably selected from the group consisting of t-butyl-peroxybenzoate; the aromatic peroxide may be present in the composition in a concentration ranging from 30 wt% to 99.9 wt% relative to the total weight of the composition.

Preferably, the composition according to the invention comprises:

a) T-butyl-peroxybenzoate, which may be present in the composition at a concentration ranging from 30% to 99.9% by weight, relative to the total weight of the composition,

b) At least hydrogen peroxide, preferably present in a concentration of 0.005 to 10 wt%, preferably 0.005 to 5 wt%, preferably 0.005 to 1.5 wt%, more preferably 0.05 to 1.5 wt%, more preferably 0.1 to 1.5 wt%, and even more preferably 0.1 to 1.2 wt%, relative to the total weight of the composition,

Additive agent

The compositions of the present invention may comprise one or more additives.

Preferably, the additive is a compound having an ether group, preferably a compound having the following formula (V) or (VI):

R ₁ -(O-C ₂ H ₄ ) _n -O-R ₂

(V)

or (b)

R ₁ -(O-CH ₂ -CH(CH ₃ )) _n -O-R ₂

(VI)

Wherein:

n represents an integer ranging from 1 to 8,

·R ₁ and R is ₂ Independently of each other, represent:

-a hydrogen atom, or

-substituted or unsubstituted linear or branched alkyl C ₁ -C ₈ Alkyl, or

-R ₁ And R is ₂ Together form an ether crown, said ether crown preferably having 4 to 8 ethylene oxide groups, more preferably having 4 to 5 ethylene oxide groups, even more preferably having 5 ethylene oxide groups.

Preferably, R ₁ Represents a hydrogen group or a methyl group, more preferably a hydrogen group.

Preferably, R ₂ Represents a substituted or unsubstituted linear or branched alkyl C ₁ -C ₈ Alkyl, more preferably represents linear C ₁ -C ₈ Alkyl, more preferably C ₂ An alkyl group.

Preferably, n represents an integer ranging from 1 to 3, more preferably equal to 2.

Preferably, R ₁ Represents a hydrogen group or a methyl group, more preferably a hydrogen group, and R ₂ Represents a substituted or unsubstituted linear or branched alkyl C ₁ -C ₈ Alkyl groups, more preferably representing linear C ₁ -C ₈ Alkyl groups, more preferably C ₂ An alkyl group.

Preferably, R ₁ Represents a hydrogen group or a methyl group, more preferably a hydrogen group, R ₂ Represents a substituted or unsubstituted, linear or branched alkyl group C ₁ -C ₈ Alkyl groups, more preferably representing linear C ₁ -C ₈ Alkyl groups, more preferably C ₂ An alkyl group, and n represents an integer ranging from 1 to 3, more preferably equal to 2.

Preferably, the compound having an ether group has formula (V) as defined above.

Preferably, the compound having an ether group is selected from the group consisting of di (ethylene glycol) ethyl ether (EDGE), di (ethylene glycol) ethyl methyl ether (DEGMEE), 1,4,7,10, 13-pentoxy cyclopentadecane, di (propylene glycol) ethyl ether, di (propylene glycol) ethyl methyl ether, and mixtures thereof, more preferably from the group consisting of di (ethylene glycol) ethyl ether, di (ethylene glycol) ethyl methyl ether, and mixtures thereof, even more preferably di (ethylene glycol) ethyl ether.

Preferably, the compound having an ether group is present in a concentration ranging from 0.1% to 20% by weight, relative to the total weight of the composition.

Preferably, the composition according to the invention exhibits an APHA color value lower than or equal to 200, preferably 150, more preferably 100, for a period of at least 5 days, in particular at least 15 days, in particular at least 20 days, preferably at least 30 days, more preferably at least 50 days, even more in particular at least 90 days, in particular at room temperature, preferably in the dark.

Preparation of the composition

The invention also relates to a process for preparing the above composition, which comprises mixing at least one aromatic peroxide as defined previously with at least hydrogen peroxide as defined previously.

Preferably, at least the aromatic peroxide as defined above and the hydrogen peroxide as defined above may be blended and stirred by any method known to the person skilled in the art.

The resulting composition shows the advantage of being color stable over time.

Use of a composition

Another object of the present invention relates to the use of the above composition for the preparation of a polymer, preferably a styrenic polymer, or a polymer resin, in particular a polymer ester resin, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins, more preferably from unsaturated polyester resins and vinyl ester resins.

Preferably, the styrenic polymer is selected from the group consisting of polystyrene, high Impact Polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS) copolymer, acrylonitrile-styrene acrylate (ASA) copolymer, styrene Acrylonitrile (SAN) copolymer, SAN modified by an elastomer, methacrylate-butadiene-styrene (MBS) copolymer, styrene-butadiene-Styrene Block (SBS) copolymer and partially or fully hydrogenated derivatives thereof, styrene-isoprene copolymer, styrene-isoprene-styrene (SIS) block copolymer and partially or fully hydrogenated derivatives thereof, and styrene- (meth) acrylate copolymers such as styrene-methyl methacrylate copolymer (S/MMA).

Preferably, the styrenic polymer is selected from the group consisting of polystyrene, acrylonitrile-butadiene-styrene (ABS) copolymer and Styrene Acrylonitrile (SAN) copolymer.

As contemplated herein, the expression "polymer resin" refers to a polymer that is associated (in association with) or not with a reactive polymer.

As contemplated herein, the expression "polymeric ester resin" refers to a polymer comprising repeating ester units, either associated with or not, with a reactive polymer.

Preferably, the polymeric resin is selected from the group consisting of polymeric ester resins, in particular unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins. More preferably, the polymer ester resin is selected from unsaturated polyester resins and vinyl ester resins, and even more preferably, the polymer resin is an unsaturated polyester resin.

Methods of synthesizing polymeric resins are well known to those skilled in the art.

Preferably, the polymer is dissolved in the reactive monomer composition, i.e. the composition comprising the reactive monomer. Preferably, the reactive monomer according to the present invention may react with the polymer according to the present invention by copolymerization.

Preferably, the reactive monomer is selected from the group consisting of vinyl compounds, acrylic compounds and allyl compounds.

As examples of vinyl compounds which can be used according to the invention, mention may be made of styrene compounds, such as styrene, methyl styrene, p-chlorostyrene, tert-butyl styrene, divinylbenzene or bromostyrene, vinyl naphthalene, divinyl naphthalene, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl ether and divinyl ether.

As examples of acrylic compounds which can be used according to the invention, mention may be made of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, phenyl acrylate and benzyl acrylate.

As examples of allyl compounds which can be used according to the invention, mention may be made of allyl phthalate, diallyl isophthalate, triallyl cyanurate and diallyl terephthalate.

Preferably, the polymer of the unsaturated polyester resin according to the invention is obtainable by condensation of one or more acid monomers and/or one or more anhydride monomers with one or more polyol monomers, provided that at least one of the components comprises ethylenic unsaturation. More preferably, the unsaturated polyester resin according to the invention is obtained by condensation of one or more polycarboxylic acid monomers and/or one or more polycarboxylic acid anhydride monomers and one or more diol monomers, provided that at least one of the components comprises ethylenic unsaturation.

Preferably, the polymer of the vinyl ester polymer resin according to the present invention is obtainable by condensation of one or more polyepoxide resins with one or more monocarboxylic acid monomers having ethylenic unsaturation.

The acid monomer according to the present invention may be of any type known to those skilled in the art. However, the acid monomers according to the invention are preferably selected from: phthalic acid, maleic acid, oxalic acid, malonic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, succinic acid, sebacic acid, azelaic acid, adipic acid and fumaric acid.

The monocarboxylic acid monomers according to the present invention may be of any type known to those skilled in the art. Preferably, the monocarboxylic acid monomer according to the present invention is selected from the group consisting of acrylic acids such as methacrylic acid, ethacrylic acid, propylacrylic acid, isopropylacrylic acid, butylacrylic acid, isobutylacrylic acid, phenylacrylic acid, benzylacrylic acid, halogenated acrylic acid and cinnamic acid.

The anhydride monomer according to the invention may be of any type known to the person skilled in the art. Preferably, the anhydride monomer according to the invention is selected from phthalic anhydride, maleic anhydride, oxalic anhydride, malonic anhydride, isophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, sebacic anhydride, azelaic anhydride, adipic anhydride and fumaric anhydride.

The polyol according to the invention may be of any type known to the person skilled in the art. Preferably, the polyol according to the invention is a diol selected from aliphatic diols and aromatic diols. More preferably, the polyol according to the invention is selected from ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, pentanediol, hexanediol and neopentyl glycol.

The polyepoxide resin according to the present invention may be of any type known to those skilled in the art. The polyepoxide resin according to the present invention is preferably selected from the group consisting of glycidyl polyethers of polyols and glycidyl polyethers of polyphenols.

Preferably, the polymer resin according to the invention is a thermosetting resin, in particular a polymer ester resin, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins.

The polymer of the invention may comprise a reinforcing material, preferably selected from: glass fibers, carbon fibers, nylon fibers, and natural fibers.

In particular, the polymer may be a polyurethane-polyacrylate composition, which is mixed with a reinforcing material, preferably selected from: glass fibers, carbon fibers, nylon fibers, and natural fibers. In particular, the present invention relates to the use of a composition as defined before as a curing agent for the preparation of a polymer resin, preferably a polymer ester resin, or as a free radical initiator for the polymerization of unsaturated monomers, preferably unsaturated based styrene based monomers.

According to the present invention, the term "polymerization" also covers the characteristic "copolymerization".

The polymer resin according to the invention, in particular the polymer ester resin, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins, is preferably curable by adding the composition according to the invention as a curing agent at a temperature allowing a curing reaction.

Use of hydrogen peroxide

A further aspect of the invention relates to the use of at least hydrogen peroxide as defined before for improving the color stability of at least one aromatic peroxide as defined before, in particular at a temperature of 15 ℃ to 30 ℃, especially 20 ℃ to 30 ℃, and preferably in the dark.

Furthermore, the present invention relates to the use of at least hydrogen peroxide as defined before for reducing the APHA value of at least one aromatic peroxide as defined before, in particular at a temperature of 15 ℃ to 50 ℃, especially 20 ℃ to 40 ℃.

Preferably, the present invention relates to the use of at least hydrogen peroxide for improving the color stability of at least one aromatic peroxide selected from the group consisting of tert-butyl-peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoylperoxy) hexane, preferably tert-butyl-peroxybenzoate, in particular at a temperature of 15 ℃ to 30 ℃, especially 20 ℃ to 30 ℃.

Polymer resin composition

The present invention also relates to a polymer resin composition comprising:

at least one composition as defined above,

at least one polymer resin as described previously, preferably chosen from unsaturated polyester resins.

The following examples are given as illustrations of the present invention.

Examples

Example 1

I.Organic peroxide tested

The peroxides carried out in the protocols described below are listed below:

tert-butyl peroxybenzoate, namedThe sale of P is carried out,

hydrogen peroxide

II.Composition to be tested

The following compositions were prepared using the ingredients described in table 1. The content is expressed in weight percent relative to the total weight of the composition.

TABLE 1

Scheme for preparing composition B:

99 g ofP and 1 g of a mixture containing 70% H ₂ O ₂ Is stirred in a tank under mechanical stirring for a period of 10 minutes and the resulting mixture is allowed to stand for 30 minutes.

The oil phase was then filtered with magnesium sulfate.

The composition is then filtered to remove the solid phase.

III.Experimental protocol

The color stability of each of the disclosed compositions in a closed tube has been evaluated using a spectrocolorimeter from the company Hatch sold under the name LICO 620 at temperatures of 25℃and 40 ℃.

The APHA color value of each composition was measured over a period of 80 days.

The results have been plotted in fig. 1 and 2.

IV.Results

FIG. 1 shows the results of measurements of APHA of compositions A-B shown in Table 1 with respect to time at a temperature of 40 ℃.

FIG. 2 shows the APHA of compositions A-B shown in Table 1 with respect to time at 25 ℃.

The results show that the APHA value measured at 25 ℃ and 40 ℃ for composition B is lower than the APHA value measured for composition a comprising only t-butyl peroxybenzoate.

In particular, the results detailed in FIG. 1 outline that correspond to the blank compared to composition BComposition a of the P product color spikes over a period of less than 20 days. />

Thus, the results demonstrate that the composition according to the invention has better color stability over time than a composition comprising only aromatic peroxides.

The results also indicate that the addition of hydrogen peroxide results in a decrease in the APHA value of t-butyl peroxybenzoate at 25 ℃ and 40 ℃.

Example 2

I.The component to be measured

The ingredients carried out in the protocols described below are listed below:

tert-butyl peroxybenzoate, namedThe sale of P is carried out,

hydrogen peroxide (70 wt%) Albone from Arkema

Isopropyl alcohol (IPOH, anhydrous, 99.5 wt.%) from Merck

Di (ethylene glycol) ethyl ether (EDGE CAS N. Degree. 111-90-0), from Merck

II.Composition to be tested

The following compositions were prepared simultaneously with the ingredients described in table 2. The content is expressed in weight percent relative to the total weight of the composition. The protocol used to prepare compositions B1-C1 was the same as that described in example 1.

Table 2: ]

III.Experimental protocol

The color stability of each of the disclosed compositions in a closed tube at a temperature of 40 ℃ in the dark has been evaluated using a spectrocolorimeter sold under the name LICO 620 from Hach corporation.

For composition A1, the APHA color value of each composition was measured over a period of 50 days, and for compositions B1 and C1, the APHA color value of each composition was measured over a period of 85 days.

The results are plotted in fig. 3.

IV.Results

FIG. 3 shows the APHA values of the compositions A1 to C1 shown in Table 2 at a temperature of 40℃with respect to time.

The results show that compositions B1 and C1 comprising a mixture of aromatic peroxide, solvent and hydrogen peroxide exhibit better color stability at a temperature of 40 ℃ than composition a comprising only t-butyl peroxybenzoate.

In fact, the results show that compositions B1 and C1 have lower APHA values measured at a temperature of 40℃than compositions A1 comprising only t-butyl peroxybenzoate.

The results also indicate that the addition of hydrogen peroxide results in a decrease in the APHA value of the t-butyl peroxybenzoate.

Example 3

In the following examples, after addition of hydrogen peroxide at 25℃and 40℃the pre-storage for 21 days was closely monitoredColor evolution of P product.

I.Experimental protocol

First, the fresh product sold by Arkema has been madeP can be used to evaluate its color at room temperature using a spectrocolorimeter sold under the name LICO 620 from the company latch. The color of this product has been observed to be 30APHA.

The product was then stored in a closed tube at a temperature of 40 ℃ under standard conditions for a period of 21 days, i.e. during which the product was not stirred.

After this time, the color of the product was measured again with the above-mentioned spectrocolorimeter, and a pale yellow development was observed. This color evolution is caused by The fact that P has an APHA value of about 600 supports.

Hydrogen peroxide was then added at a concentration of 1 wt%In the P product. The resulting mixture was then stored for a period of 90 days.

The results are plotted in fig. 4.

II.Results

FIG. 4 shows the APHA number as a function of time measured at a temperature of 40℃and in the dark.

It was observed that the addition of hydrogen peroxide resulted in a decrease in the APHA value of t-butyl peroxybenzoate over time at 40 ℃.

The addition of hydrogen peroxide is said to reduce the 21 days of pre-storage in the darkThe pale yellow color of the P product. />

Claims

1. A composition comprising:

b) At least hydrogen peroxide

The weight ratio of hydrogen peroxide to aromatic peroxide is between 1:20000 and 1:40, more preferably between 1:2000 and 1:50, even more preferably between 1:800 and 1:80.

2. The composition according to claim 1, characterized in that the aromatic peroxide comprises at least one benzene ring.

3. Composition according to claim 1 or 2, characterized in that the aromatic peroxide is selected from the group consisting of aromatic peresters, aryl-alkyl peroxides, aryl hydroperoxides, aromatic diacyl peroxides and mixtures thereof, preferably aromatic peresters.

4. A composition according to claim 3, characterized in that the aromatic perester is selected from perbenzoates, aryl peresters, aromatic diperoxates and mixtures thereof, preferably perbenzoates.

5. Composition according to claim 1, characterized in that the aromatic peroxide has the following formula (I):

R ₁ -O-O-R ₂

(I)

wherein:

·R ₁ the representation is:

--C(＝O)R’ ₁ a group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or an aryl group having 6 to 32 carbon atoms substituted by one or more halogen atoms, or

Linear or branched C blocked with aryl groups having from 6 to 32 carbon atoms ₁ -C ₂₀ Alkyl, optionally linear or branched C ₁ -C ₁₀ Alkyl substituted, optionally substituted with a peroxy group and/or one or more halogen atoms; or (b)

--CR’ ₁ A group wherein R' ₁ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or one or more halogen atom substituted aryl groups having 6 to 32 carbon atoms,

·R ₂ the representation is:

Linear or branched C ₁ -C ₂₀ An alkyl group, a hydroxyl group,

c optionally linear or branched ₁ -C ₁₀ An alkyl group and/or one or more halogen atom substituted aryl groups having 6 to 32 carbon atoms,

--R ₃ OOR ₄ a group, wherein R is ₃ C representing a linear or branched chain ₈ -C ₂₀ Alkyl groups, preferably C ₈ -C ₁₀ An alkyl group, and R ₄ represents-C (=O) R' ₄ A group wherein R' ₄ Represents aryl radicals having 6 to 32 carbon atoms, which are optionally linear or branched C ₁ -C ₁₀ Alkyl groups and/or one or more halogen atoms,

linear or branched C blocked with aryl groups having from 6 to 32 carbon atoms ₁ -C ₂₀ Alkyl, optionally linear or branched C ₁ -C ₁₀ Alkyl and/or one or more halogen atoms,

--C(＝O)R’ ₂ a group wherein R' ₂ Represents optionally linear or branched C ₁ -C ₁₀ An alkyl group and/or an aryl group having 6 to 32 carbon atoms substituted by one or more halogen atoms, or

-a hydrogen atom.

6. The composition of any of the preceding claims, wherein the aromatic peroxide is selected from the group consisting of t-butyl-peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoylperoxy) hexane, t-butyl cumyl peroxide, dicumyl peroxide, cumene hydroperoxide, bis (2, 4-dichlorobenzoyl) peroxide 1,3, 4-bis (t-butylperoxyisopropyl) benzene, and mixtures thereof, preferably t-butyl-peroxybenzoate, cumyl peroxyneoheptanoate, cumyl peroxyneodecanoate, 2, 5-dimethyl-2, 5- (dibenzoylperoxy) hexane, and mixtures thereof.

7. Composition according to any one of the preceding claims, further comprising at least one compound having an ether group, preferably a compound having the following formula (V) or (VI):

R ₁ -(O-C ₂ H ₄ ) _n -O-R ₂

(V)

or (b)

R ₁ -(O-CH ₂ -CH(CH ₃ )) _n -O-R ₂

(VI)

Wherein:

n represents an integer ranging from 1 to 8,

·R ₁ and R is ₂ Independently of each other, represent:

-a hydrogen atom, or

-substituted or unsubstituted linear or branched alkyl C ₁ -C ₈ Alkyl, or

8. Composition according to any one of the preceding claims, characterized in that it further comprises at least one ketone peroxide, preferably selected from the group consisting of methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, 2, 4-pentanedione peroxide, and mixtures thereof, even more preferably methyl ethyl ketone peroxide or methyl isobutyl ketone peroxide.

9. The composition according to any one of the preceding claims, further comprising at least one solvent of the following: the solvent is an organic solvent selected from the group consisting of ketone solvents, aryl solvents, ether solvents, alcohol solvents, mineral oils and hydrocarbon solvents, preferably selected from the group consisting of ketone solvents and alcohol solvents.

10. A process for preparing a composition as defined in any one of the preceding claims, comprising mixing at least one aromatic peroxide as defined in any one of claims 1 to 6 with at least hydrogen peroxide.

11. Use of a composition as defined in any one of claims 1 to 9 for the preparation of a polymer, preferably a styrenic polymer or a polymer resin, in particular a polymer ester resin, preferably selected from unsaturated polyester resins, acrylic resins, methacrylic resins and vinyl ester resins, more preferably from unsaturated polyester resins and vinyl ester resins.

12. Use of a composition as defined in any one of claims 1 to 9 as a curing agent for the preparation of a polymer resin, preferably a polymer ester resin, according to claim 11.

13. Use of a composition as defined in any one of claims 1 to 9 as a free radical initiator for the polymerization of unsaturated monomers, preferably unsaturated styrene-based monomers.

14. Use of at least hydrogen peroxide for improving the color stability or reducing the APHA value of at least one aromatic peroxide, as defined according to any one of claims 1 to 6.

15. A polymer resin composition comprising:

at least one composition as defined in any one of claims 1 to 9,

-at least one polymer resin according to claim 11, preferably selected from unsaturated polyester resins.