METHOD FOR PURIFYING ALKYL HYDROPEROXIDE BY EXTRACTION WITH WATER AND SEPARATION OF THE AQUEOUS PHASE

Abstract

The present invention relates to a method for purifying a mixture containing at least one alkyl hydroperoxide, preferably tert-butyl hydroperoxide or tert-amyl hydroperoxide, and at least one corresponding dialkyl hydroperoxide, said method comprising at least one step of extraction with water and at least one separation step which is carried out within the aqueous phase, obtained following the extraction step, in order to recover an aqueous solution which is rich in alkyl hydroperoxide. The invention also relates to an aqueous composition which is rich in alkyl hydroperoxide and contains at least 0.1% by weight of dialkyl peroxide in relation to the total weight of the composition.

Claims

1-20. (canceled)

21. A process for the purification of a mixture containing at least one alkyl hydroperoxide and at least one alkyl peroxide, wherein it successively comprises: a) at least one stage of extraction, carried out with water, of said mixture so as to obtain a first phase rich in alkyl hydroperoxide and a second phase rich in dialkyl peroxide, b) at least one stage of concentration of the first phase obtained in stage a) so as to obtain two new phases, known as third and fourth phase, c) optionally a stage of separation by settling of the third phase so as to obtain a fifth and sixth phase, d) optionally a stage of recovery of the fifth phase obtained in stage c).

22. The process as claimed in claim 21, wherein the extraction stage a) is carried out with a water content which is 5 times greater than the content by weight of the mixture as defined according to claim 21.

23. The process as claimed in claim 21, wherein the concentration stage b) is carried out starting from a process employing at least one semipermeable membrane or from a distillation process.

24. The process as claimed in claim 21, wherein the concentration stage b) is carried out in order to separate the solution containing at least 60% by weight of alkyl hydroperoxide and less than 0.1% by weight of dialkyl peroxide, the proportions being calculated with respect to the total weight of the solution as defined in claim 21, and a solution containing less than 6% by weight of alkyl hydroperoxide, the proportions being calculated with respect to the total weight of the solution.

25. The process as claimed in claim 24, wherein the solution containing less than 6% by weight of alkyl hydroperoxide is recycled to the extraction stage a).

26. The process as claimed in claim 21, wherein the concentration stage b) is a distillation carried out at a temperature of between 25° C. and 60° C.

27. The process as claimed in claim 21, wherein the concentration stage b) is a distillation carried out at a pressure of between 5 and 300 mbar (millibars).

28. The process as claimed in claim 21, wherein the alkyl hydroperoxide corresponds to the following general formula R.sup.1—OO—H in which R.sup.1 represents: a linear or branched C.sub.4-C.sub.10 alkyl group optionally substituted by one or more hydroxyl groups or a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3 alkyl groups.

29. The process as claimed in claim 21, wherein R.sup.1 represents a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic or a branched C.sub.4-C.sub.10.

30. The process as claimed in claim 21, wherein the alkyl hydroperoxide is selected from the group consisting of tert-butyl hydroperoxide, tert-amyl hydroperoxide, hexylene glycol hydroperoxide, tert-octyl hydroperoxide, tert-hexyl hydroperoxide, methylcyclopentyl hydroperoxide and methylcyclohexyl hydroperoxide.

31. The process as claimed in claim 21, wherein the alkyl hydroperoxide is selected from the group consisting of tert-butyl hydroperoxide (TBHP) and tert-amyl hydroperoxide (TAHP).

32. The process as claimed in claim 21, wherein the dialkyl peroxide corresponds to the following general formula R.sup.2—OO—R.sup.3 in which R.sup.2 and R.sup.3, which are identical or different, represent: a linear or branched C.sub.4-C.sub.10 alkyl group optionally substituted by one or more hydroxyl groups, or a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3 alkyl groups.

33. The process as claimed in claim 21, wherein R.sup.2 and R.sup.3, which are identical or different, represent a branched C.sub.4-C.sub.10 alkyl group optionally substituted by one or more hydroxyl groups.

34. The process as claimed in claim 21, wherein the dialkyl peroxide is selected from the group consisting of di(tert-butyl) peroxide, di(tert-amyl) peroxide, di(3-hydroxy-1,1-dimethylbutyl) peroxide, di(tert-octyl) peroxide, di(tert-hexyl) peroxide, di(methylcyclopentyl) peroxide and di(methylcyclohexyl) peroxide.

35. The process as claimed in claim 21, wherein the dialkyl peroxide is selected from the group consisting of di(tert-butyl) peroxide and di(tert-amyl) peroxide.

36. The process as claimed in claim 21, wherein the alkyl hydroperoxide and the dialkyl peroxide exhibit identical R.sup.1, R.sup.2 and R.sup.3 groups.

37. The process as claimed in claim 21, in which the hydroperoxide is prepared in an acidic medium.

38. An aqueous composition containing at least 60% by weight of alkyl hydroperoxide in which R.sup.1 represents a linear or branched C.sub.4-C.sub.10 alkyl group optionally substituted by one or more hydroxyl groups, as defined according to claim 21, and less than 0.1% by weight of dialkyl peroxide, as defined according to claim 21, the proportions being calculated by weight with respect to the total weight of the composition.

39. The composition as claimed in claim 38, wherein the content of alkyl hydroperoxide is at least 70% by weight, with respect to the total weight of the composition.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0075] FIG. 1 diagrammatically presents the process according to the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0076] Process

Preparation of a Hydroperoxide

[0077] As indicated above, the process according to the invention relates to the purification of a mixture comprising at least one alkyl hydroperoxide and at least one dialkyl peroxide.

[0078] Preferably, said mixture is obtained following the preparation of the alkyl hydroperoxide in question.

[0079] In other words, the process according to the invention is targeted at purifying an alkyl hydroperoxide obtained by synthesis.

[0080] Preferably, the alkyl hydroperoxide can be prepared in an acidic medium.

[0081] In other words, the process according to the invention can comprise a stage a′), prior to stage a), of synthesis of said alkyl hydroperoxide in an acidic medium.

[0082] In this case, the method of preparation of the alkyl hydroperoxide consists in particular in reacting aqueous hydrogen peroxide solution in the presence of at least one alcohol or of at least one alkene in an acidic medium.

[0083] Preferably, the method of preparation of the alkyl hydroperoxide consists in particular in reacting aqueous hydrogen peroxide solution in the presence of at least one alcohol or one unsaturated compound in an acidic medium.

[0084] The reaction can be carried out at a temperature which can range from 10° C. to 80° C., preferably 20° C. to 40° C.

[0085] Preferably, the reaction is carried out in the presence of one or more inorganic or organic acids, in particular one or more inorganic acids.

[0086] More preferentially, the inorganic acid is sulfuric acid.

[0087] The mixture can thus comprise at least one alkyl hydroperoxide, at least one corresponding dialkyl peroxide and at least one alcohol.

[0088] Preferably, said at least one dialkyl peroxide is a dialkyl peroxide corresponding to the alkyl hydroperoxide to be purified.

[0089] The term “corresponding dialkyl peroxide” is understood to mean, within the meaning of the present invention, the alkyl peroxide which originates from the synthesis of the alkyl hydroperoxide.

[0090] In other words, the corresponding dialkyl peroxide refers to the compound which is formed during synthesis of the alkyl hydroperoxide.

[0091] The mixture can comprise at least one alkyl hydroperoxide in a content of at least 40% by weight, preferably 50% by weight, preferably 60% by weight and more preferentially 68%, with respect to the total weight of the mixture.

[0092] The mixture can comprise at least 1% by weight, preferably at least 2% by weight, more preferentially at least 3% by weight, of dialkyl peroxide, with respect to the total weight of the mixture.

[0093] Preferably, the mixture can comprise less than 25%, preferably less than 10% by weight, preferably less than 8% by weight, of dialkyl peroxide, with respect to the total weight of the mixture.

[0094] The alkyl hydroperoxide can also be obtained by oxidation of at least one alkane or of at least one corresponding alkene.

[0095] The mixture can thus comprise at least one alkyl hydroperoxide, at least one corresponding dialkyl peroxide, at least one alkane or at least one alkene in the presence of one or more oxidizing agents.

[0096] Stage a) of Extraction with Water

[0097] The process according to the invention comprises at least one stage a) of extraction, carried out with water, of the mixture as defined above.

[0098] Stage a) of extraction with water can be carried out one or more times according to the conventional liquid extraction processes as described, for example, in the work entitled “Chemical Engineer's Handbook”, 5.sup.th edition of 1973, Perry et al.

[0099] Preferably, the extraction stage a) is carried out by bringing water into contact with the mixture, as defined above, preferably obtained following the preparation of the alkyl hydroperoxide.

[0100] Preferably, the extraction stage a) is carried out with an excess amount of water, with respect to the total weight of the mixture as defined above.

[0101] More preferentially, the extraction stage a) is carried out with a water content which is 5 times greater, in particular 10 times greater, more particularly 15 times greater, than the content by weight of the mixture defined above.

[0102] Advantageously, the extraction stage a) is carried out with a water content which is 10 times greater than the content by weight of the mixture defined above.

[0103] The extraction stage a) is carried out so as to obtain two phases.

[0104] Thus, the extraction stage a) is carried out so as to obtain: [0105] a first phase (rich in alkyl hydroperoxide); [0106] a second phase (rich in dialkyl peroxide).

[0107] The first phase contains the alkyl hydroperoxide and a fraction by weight of the corresponding dialkyl peroxide. In particular, the alkyl hydroperoxide is water-soluble.

[0108] The term “rich in alkyl hydroperoxide” is understood to mean that this phase contains more than 70%, preferably more than 80%, more preferably more than 90% by weight of the hydroperoxide present in the mixture before stage a).

[0109] The term “water-soluble” is understood to mean, within the meaning of the present invention, that the alkyl hydroperoxide exhibits, at a temperature of 25° C. and at atmospheric pressure (760 mm Hg, i.e. 1.013×10.sup.5 Pa), a solubility in water of at least 4% by weight.

[0110] The second phase contains a predominant fraction by weight of the dialkyl peroxide, in particular the complementary predominant fraction by weight of the dialkyl peroxide occurring in the first phase.

[0111] The second phase can also contain, for example, at least alcohol and optionally one or more byproducts, resulting from the method for the preparation of the alkyl hydroperoxide, which are soluble in the second phase.

[0112] The formation of two phases, after the extraction stage a), takes place in particular at the time of the separation by settling of the composition resulting from the mixture, as defined above, and of the water.

[0113] Once separated by settling, the second phase is located above the first phase.

[0114] Stage a) can be carried out batchwise or continuously.

[0115] Concentration Stage b)

[0116] The first phase is recovered following stage a) of extraction with water.

[0117] The concentration stage b) consists in particular in separating, from the first phase obtained in stage a), a third phase rich in alkyl hydroperoxide and a fourth phase depleted in alkyl hydroperoxide.

[0118] Stage b) can be carried out starting from a process employing at least one semi-permeable membrane or from a distillation process.

[0119] The term “semi-permeable membrane” is understood to mean, within the meaning of the present invention, a selective organic or synthetic membrane capable of allowing a large amount of water to pass through and not the substances occurring in solution.

[0120] In this way, a process employing at least one semi-permeable membrane makes it possible to recover a solution rich in water, i.e. an aqueous phase depleted in alkyl hydroperoxide, and an aqueous solution enriched in alkyl hydroperoxide.

[0121] The process employing at least one semi-permeable membrane can be a reverse osmosis process or a pervaporation process.

[0122] Preferably, stage b) is carried out starting from a distillation process.

[0123] This is because the distillation process exhibits the advantage of leading to efficient and rapid separation.

[0124] Preferably, the distillation is carried out at a temperature of between 25° C. and 60° C., preferentially between 30° C. and 45° C.

[0125] Advantageously, the distillation is carried out at a pressure of between 5 and 300 mbar (millibars), preferentially between 30 and 200 mbar, preferentially between 40 and 180 mbar and more preferentially between 50 and 160 mbar.

[0126] The fourth phase depleted in alkyl hydroperoxide is preferably a solution containing less than 6%, preferably less than 5%, preferably less than 4%, preferably less than 3%, preferably less than 2%, preferably less than 1%, by weight of alkyl hydroperoxide, with respect to the total weight of the solution.

[0127] The fourth phase depleted in alkyl hydroperoxide is advantageously recycled to the extraction stage a) so as to retain the amount of water necessary to carry out stage a).

[0128] The recycling can be carried out continuously or noncontinuously.

[0129] Stage c) of Separation by Settling

[0130] The third phase obtained in stage b) spontaneously separates by settling into two new phases: [0131] a fifth upper phase (rich in alkyl hydroperoxide); [0132] a sixth lower phase (poor in alkyl hydroperoxide).

[0133] The fifth phase rich in alkyl hydroperoxide is a solution containing at least 60% by weight of alkyl hydroperoxide and less than 0.1% by weight of dialkyl peroxide.

[0134] At the end of stage c), a fifth phase containing at least 60% by weight of alkyl hydroperoxide and less than 0.1% by weight of dialkyl peroxide, the proportions being calculated by weight with respect to the total weight of the solution, is recovered.

[0135] Preferably, the fifth phase contains at least 60% by weight, preferably at least 68% by weight, of alkyl hydroperoxide, with respect to the total weight of the solution.

[0136] Stage c) makes it possible to separate the solution containing at least 60% by weight of alkyl hydroperoxide and less than 0.1% by weight of dialkyl peroxide and a solution containing less than 20% by weight of alkyl hydroperoxide, preferably less than 15%, the proportions being calculated with respect to the total weight of the solution.

[0137] Alky Hydroperoxide and Dialkyl Peroxide

[0138] As indicated above, the process according to the invention relates to the purification of a mixture comprising at least one alkyl hydroperoxide and at least one dialkyl peroxide.

[0139] The alkyl hydroperoxide preferably corresponds to the following general formula R.sup.1—OO—H in which R.sup.1 represents:

[0140] a linear or branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, alkyl group optionally substituted by one or more hydroxyl groups or

[0141] a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3 alkyl groups.

[0142] In particular, R.sup.1 can represent a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3 alkyl groups, in particular by a C.sub.1 alkyl group.

[0143] More particularly, R.sup.1 can represent a nonaromatic cyclic group comprising from 5 to 8 carbon atoms which is optionally substituted by a C.sub.1 alkyl group.

[0144] Preferably, the alkyl hydroperoxide is a tert-alkyl hydroperoxide.

[0145] Preferably, R.sup.1 represents a branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, more preferentially still C.sub.4-C.sub.8, alkyl group.

[0146] Preferably, the alkyl hydroperoxide is chosen from the group consisting of tert-butyl hydroperoxide, tert-amyl hydroperoxide, hexylene glycol hydroperoxide, tert-octyl hydroperoxide, tert-hexyl hydroperoxide, methylcyclopentyl hydroperoxide and methylcyclohexyl hydroperoxide.

[0147] More preferentially, the alkyl hydroperoxide is chosen from the group consisting of tert-butyl hydroperoxide (TBHP) and tert-amyl hydroperoxide (TAHP), more preferentially still tert-amyl hydroperoxide (TAHP).

[0148] Advantageously, the dialkyl peroxide corresponds to the following general formula R.sup.2—OO—R.sup.3 in which R.sup.2 and R.sup.3, which are identical or different, in particular identical, represent: [0149] a linear or branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, alkyl group optionally substituted by one or more hydroxyl groups, or [0150] a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3, in particular C.sub.1, alkyl groups.

[0151] In particular, R.sup.2 and R.sup.3 can represent a cyclic group comprising from 5 to 8 carbon atoms which is optionally aromatic and which is optionally substituted by one or more C.sub.1-C.sub.3, in particular C.sub.1, alkyl groups.

[0152] More particularly, R.sup.1 and R.sup.3 can represent a nonaromatic cyclic group comprising from 5 to 8 carbon atoms which is optionally substituted by a C.sub.1 alkyl group.

[0153] Preferably, the dialkyl peroxide is a di(tert-alkyl) peroxide.

[0154] Preferably, R.sup.2 and R.sup.3, which are identical or different, represent a branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, alkyl group optionally substituted by one or more hydroxyl groups.

[0155] Preferably, R.sup.2 and R.sup.3, which are identical or different, represent a branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, alkyl group.

[0156] More preferentially still, the dialkyl peroxide is symmetrical, that is to say that the groups flanking the O—O group are identical. In other words, R.sup.2 and R.sup.3 are more preferentially identical and represent a branched C.sub.4-C.sub.10, preferably C.sub.4-C.sub.8, more preferentially C.sub.4-C.sub.6, alkyl group.

[0157] Preferably, the dialkyl peroxide is chosen from the group consisting of di(tert-butyl) peroxide, di(tert-amyl) peroxide, di(3-hydroxy-1,1-dimethylbutyl) peroxide, di(tert-octyl) peroxide, di(tert-hexyl) peroxide, di(methylcyclopentyl) peroxide and di(methylcyclohexyl) peroxide.

[0158] More preferentially, the dialkyl peroxide is chosen from the group consisting of di(tert-butyl) and di(tert-amyl) peroxide.

[0159] More preferentially still, the dialkyl peroxide is di(tert-amyl) peroxide.

[0160] Advantageously, the alkyl hydroperoxide and the dialkyl peroxide exhibit identical R.sup.1, R.sup.2 and R.sup.3 groups.

[0161] Preferably, the alkyl hydroperoxide is tert-amyl hydroperoxide (TAHP) and the dialkyl peroxide is di(tert-amyl) peroxide (DTA).

[0162] Alternatively, the alkyl hydroperoxide is preferably tert-butyl hydroperoxide (TBHP) and the dialkyl peroxide is di(tert-butyl) peroxide (DTBP).

[0163] Alternatively, the alkyl hydroperoxide is hexylene glycol hydroperoxide and the dialkyl peroxide is di(3-hydroxy-1,1-dimethylbutyl) peroxide.

[0164] Alternatively, the alkyl hydroperoxide is tert-octyl hydroperoxide and the dialkyl peroxide is di(tert-octyl) peroxide.

[0165] Alternatively, the alkyl hydroperoxide is tert-hexyl hydroperoxide and the dialkyl peroxide is di(tert-hexyl) peroxide.

[0166] According to an advantageous embodiment, the invention relates to a process for the purification of a mixture containing at least one alkyl hydroperoxide chosen from the group consisting of tert-amyl hydroperoxide, tert-butyl hydroperoxide, hexylene glycol hydroperoxide, tert-octyl hydroperoxide and tert-hexyl hydroperoxide, and at least one dialkyl peroxide chosen from the group consisting of di(tert-amyl) peroxide, di(tert-butyl) peroxide, di(3-hydroxy-1,1-dimethylbutyl) peroxide, di(tert-octyl) peroxide and di(tert-hexyl) peroxide, said mixture preferably being obtained following the preparation of the alkyl hydroperoxide in question, comprising successively:

[0167] a) at least one stage of extraction, carried out with water, of the mixture so as to obtain a first phase rich in alkyl hydroperoxide and a second phase rich in dialkyl peroxide,

[0168] b) at least one stage of distillation of the first phase obtained in stage a),

[0169] c) optionally a stage of separation by settling of the third phase so as to obtain a fifth and sixth phase,

[0170] d) optionally a stage of recovery of the fifth phase obtained in stage c).

[0171] In accordance with this embodiment, the mixture is obtained in particular following the preparation of the alkyl hydroperoxide in an acidic medium.

[0172] Composition

[0173] The invention also relates to an aqueous composition containing at least 60% by weight of alkyl hydroperoxide as defined above and less than 0.1% by weight of dialkyl peroxide as defined above, the proportions being calculated by weight with respect to the total weight of the composition.

[0174] Preferably, the aqueous composition contains at least 68% by weight of alkyl hydroperoxide as defined above, more preferentially at least 80% by weight.

[0175] Preferably, R.sup.1 represents a branched, optionally substituted, C.sub.4-C.sub.10, preferably C.sub.5-C.sub.10, preferably C.sub.5-C.sub.8, more preferentially C.sub.5-C.sub.6, more preferentially still C.sub.5, alkyl group.

[0176] The alkyl hydroperoxide is preferably chosen from the group consisting of tert-amyl hydroperoxide, hexylene glycol hydroperoxide, tert-octyl hydroperoxide and tert-hexyl hydroperoxide.

[0177] More preferentially, the alkyl hydroperoxide is tert-amyl hydroperoxide (TAHP).

[0178] Advantageously, the aqueous composition contains less than 0.08% by weight, preferably less than 0.07% by weight, of dialkyl peroxide, preferably less than 0.05% by weight of dialkyl peroxide, preferably less than 0.025% by weight of dialkyl peroxide, more preferentially less than 0.01% by weight of dialkyl peroxide, with respect to the total weight of the composition.

[0179] Preferably, the dialkyl peroxide chosen from the group consisting of di(tert-amyl) peroxide, di(3-hydroxy-1,1-dimethylbutyl) peroxide, di(tert-octyl) peroxide and di(tert-hexyl) peroxide.

[0180] More preferentially, the dialkyl peroxide is di(tert-amyl) peroxide.

[0181] Advantageously, the aqueous composition contains at least 60% by weight of tert-amyl hydroperoxide (TAHP) and less than 0.1% by weight of di(tert-amyl) peroxide (DTA), the proportions being calculated by weight with respect to the total weight of the composition.

[0182] The present invention also relates to an aqueous composition rich in alkyl hydroperoxide capable of being obtained by the process according to the invention.

Use of the Composition

[0183] The present invention also relates to the use of the composition as defined above for the preparation of crosslinking agent(s) or polymerization initiator(s).

[0184] Preferably, the initiator(s) is or are initiators of polymerization by the radical route, in particular of ethylene under high pressure.

[0185] The term “high pressure” is understood to mean, within the meaning of the present invention, a pressure of greater than 50 MPa. Preferably, the pressure varies from 500 bar (50 MPa) to 3000 bar (300 MPa), preferentially from 1200 bar (120 MPa) to 3000 bar (300 MPa), better still from 1200 bar (120 MPa) to 2600 bar (260 MPa).

[0186] Preferably, the crosslinking agents or the polymerization initiators are chosen from the group consisting of organic peroxides, in particular peroxyesters, hemiperoxyacetals and peroxyacetals.

[0187] The term “hemiperoxyacetal” is understood to mean a compound of general formula (R.sub.3)(R.sub.4)C(—OR.sub.1)(—OOR.sub.2), in which:

[0188] R.sub.1 represents a linear or branched, preferably C.sub.1-C.sub.12, preferably C.sub.1-C.sub.4, more preferably C.sub.1, alkyl group or a cycloalkyl group with R.sub.2,

[0189] R.sub.2 represents a linear or branched, preferably C.sub.1-C.sub.12, preferably C.sub.4-C.sub.12, more preferably C.sub.5, alkyl group or a cycloalkyl group with R.sub.1,

[0190] R.sub.3 represents a hydrogen or a linear or branched, preferably C.sub.1-C.sub.12, more preferably C.sub.4-C.sub.12, alkyl group or a cycloalkyl group with R.sub.4,

[0191] R.sub.4 represents a hydrogen or a linear or branched, preferably C.sub.1-C.sub.12, more preferably C.sub.4-C.sub.12, alkyl group or a cycloalkyl group with R.sub.3.

[0192] Preferably, R.sub.3 forms a cycloalkyl group with R.sub.4.

[0193] Preferably, when R.sub.3 is a hydrogen, R.sub.4 is a linear or branched, preferably C.sub.1-C.sub.12, more preferably C.sub.4-C.sub.12, alkyl group.

[0194] The following examples serve to illustrate the invention without limiting it.

EXAMPLES

Example 1

[0195] Starting Mixture

[0196] In the following example, the mixture treated is a solution of tert-amyl hydroperoxide (TAHP) containing 84.6% of tert-amyl hydroperoxide, 4% of di(tert-amyl) peroxide (DTA), 0.8% of acetone, 0.8% of tert-amyl alcohol and 0.9% by weight of the peroxide 2,2-di(tert-amylperoxy)propane.

[0197] Extraction Stage a)

[0198] In a closed flask, 500 ml of softened water are added to 41.2 g of the tert-amyl hydroperoxide solution described above.

[0199] The combined product is mixed for 30 minutes using a magnetic stirrer bar and is then left to separate by settling for a period of 30 minutes at ambient temperature.

[0200] Following this separation by settling, a supernatant organic phase (with the interface) of approximately 12.5 g and a slightly cloudy lower phase of approximately 528 g are formed.

[0201] Concentration Stage b)

[0202] The lower phase is introduced into a rotary evaporator flask.

[0203] The distillation takes place under 100 mbar of absolute pressure at a bath temperature of 50° C. A fifth of the aqueous phase is distilled off.

[0204] The distillate separates into an upper phase of 19 grams containing 89.2% of tert-amyl hydroperoxide (TAHP) and only 0.06% of di(tert-amyl) peroxide (DTA) and a lower phase containing 5.5% of tert-amyl hydroperoxide.

[0205] The distillation residue represents 405 g containing 0.35% of TAHP.

Example 2

[0206] Starting Mixture

[0207] In the following example, the mixture treated is a solution of tert-amyl hydroperoxide (TAHP) containing 84.6% of tert-amyl hydroperoxide, 4% of di(tert-amyl) peroxide (DTA), 0.8% of acetone, 0.8% of tert-amyl alcohol and 0.9% by weight of the peroxide 2,2-di(tert-amylperoxy)propane.

[0208] The starting mixture is identical to that of example 1.

[0209] Extraction Stage a)

[0210] In a closed flask, 500 ml of softened water are added to 41.2 g of the tert-amyl hydroperoxide solution described above.

[0211] The combined product is mixed for 30 minutes using a magnetic stirrer bar and is then left to separate by settling for a period of 60 hours at ambient temperature.

[0212] Following this separation by settling, a supernatant phase of approximately 11.5 g and a lower phase of approximately 526 g are formed.

[0213] Concentration Stage b)

[0214] A quantity of 428 g of lower phase is introduced into a rotary evaporator flask.

[0215] The distillation takes place under 100 mbar of absolute pressure at a bath temperature of 50° C. Half of the lower phase is distilled off.

[0216] The distillate separates into an upper phase of 11.5 grams containing 89% of tert-amyl hydroperoxide (TAHP) and only 0.005% of di(tert-amyl) peroxide (DTA) and a lower phase containing 4.7% of tert-amyl hydroperoxide.

[0217] The distillation residue represents 205 g containing 0.02% of TAHP.