Cyclic ketone peroxide composition

Abstract

A composition comprising at least two trimeric cyclic ketone peroxides: a trimeric cyclic methyl ethyl ketone peroxide (3MEK-cp) of formula (I) and at least one peroxide satisfying formula (II) wherein R.sup.1 through R.sup.3 are independently selected from alkyl and alkoxyalkyl groups, said groups having 2 to 5 carbon atoms, the total number of carbon plus oxygen atoms of R.sup.1?R.sup.2+R.sup.3 is in the range 7-15, and the molar ratio of 3MEK-cp to the total amount of peroxides satisfying formula (II) being in the range of from 10:90 to 80:20. ##STR00001##

Claims

1. A composition comprising at least two trimeric cyclic ketone peroxides: a trimeric cyclic methyl ethyl ketone peroxide (3MEK-cp) of formula (I) ##STR00005## and at least one peroxide satisfying formula (II) ##STR00006## wherein R.sup.1 through R.sup.3 are independently selected from alkyl and alkoxyalkyl groups, said groups having 2 to 5 carbon atoms, the total number of carbon plus oxygen atoms of R.sup.1+R.sup.2+R.sup.3 is in the range 7-15, and the molar ratio of 3MEK-cp to the total amount of peroxides satisfying formula (II) being in the range of from 10:90 to 80:20.

2. The composition according to claim 1 wherein R.sup.1 through R.sup.3 are alkyl groups having 2 to 5 carbon atoms, the total number of carbon atoms of R.sup.1+R.sup.2+R.sup.3 is in the range 7-15.

3. The composition according to claim 2 wherein the alkyl groups are linear alkyl groups.

4. The composition according to claim 1 wherein the molar ratio of 3MEK-cp to the total amount of peroxides satisfying formula (II) is in the range of from 40:60 to 80:20.

5. The composition according to claim 1 wherein the composition further comprises a diluent in an amount of 45-85 wt %, based on the weight of the composition.

6. The composition according to claim 1 wherein the total amount of trimeric cyclic ketone peroxides according to formulae (I) and (II) is in the range 15-55 wt %, based on the weight of the composition.

7. The composition according to claim 1 wherein at least one of the peroxides satisfying formula (II) is 3,6-diethyl-3,6,9-trimethyl-9-(n-propyl)-1,2,4,5,7,8-hexaoxonane.

8. The composition according to claim 1 wherein at least one of the peroxides satisfying formula (II) is 3-ethyl-3,6,9-trimethyl-6,9-di(n-propyl)-1,2,4,5,7,8-hexaoxonane.

9. The composition according to claim 1 wherein at least one of the peroxides satisfying formula (II) is 3,6,9-tri(n-propyl)-3,6,9-trimethyl-1,2,4,5,7,8-hexaoxonane.

10. A process for preparing a cyclic ketone peroxide composition, the method comprising reacting, in the presence of acid, hydrogen peroxide with a mixture of ketones comprising methyl ethyl ketone (MEK) and at least one ketone of formula CH.sub.3C(?O)R wherein R is an alkyl group with 3 to 5 carbon atoms or an alkoxyalkyl group with 2 to 5 carbon atoms, the molar ratio of MEK to the total amount of ketones of formula CH.sub.3C(?O)R being in the range 25:75 to 95:5.

11. The process according to claim 10, wherein R is an alkyl group.

12. The process according to claim 11, wherein R is n-propyl.

13. The process according to claim 10, wherein the molar ratio of MEK to the total amount of ketones of formula CH.sub.3C(?O)R is in the range of from 50:50 to 70:30.

14. A peroxide composition obtained by the process of claim 10.

15. The process of claim 13 wherein R is an alkyl group with 3 to 5 carbon atoms.

16. The process of claim 13 wherein R is n-propyl.

17. The peroxide composition of claim 14 wherein R is an alkyl group with 3 to 5 carbon atoms.

18. The peroxide composition of claim 14 wherein R is n-propyl.

19. The peroxide composition of claim 14 wherein the molar ratio of MEK to the total amount of ketones of formula CH.sub.3C(?O)R is in the range of from 50:50 to 70:30.

Description

EXAMPLES

Example 1

(1) In a 150 ml erlenmeyer H.sub.2SO.sub.4-78% (27.8 g) was added to H.sub.2O.sub.2-70% (22.8 g) at 0? C. (the premix). The premix was kept at 0? C. until needed.

(2) A 300 ml reactor equipped with a turbine stirrer, was charged with Isopar M (38 g), methyl ethyl ketone (MEK; 24.7 g, 343 mmol), and methyl n-propyl ketone (MPK; 12.6 g, 147 mmol). The molar ratio of MEK to MPK was 70:30. The mixture was stirred (1200 rpm) and cooled down to 0? C. The premix was dosed to the mixture during a period of 60 min (0.650 ml/min) while keeping the temperature between ?1? C. and +1? C. The reaction was kept at 0? C. for 75 min after dosing. The reaction was quenched by addition of water (13.8 g) and the phases were separated. The aqueous layer (bottom one) was removed.

(3) HPLC showed the formation of the following compounds in the amounts listed in Table 1.

(4) ##STR00004##

(5) A sample from the composition was stored at ?26? C. for 12 days in an isopropyl alcohol bath. After 5 days, the total active oxygen content (aO) was determined by way of a titration according to ASTM D2180-89(2008). This aO was compared with that of the fleshly prepared composition. Both before and after this storage period, the active oxygen content was 8 wt %, meaning that no significant peroxide decomposition occurred during storage.

(6) After 12 days of storage, two samples were taken. One was analysed directly by HLPC; the other sample was allowed to reach room temperature (20? C.). The results are summarized in Table 1.

(7) TABLE-US-00001 TABLE 1 Sample Sample after 12 Freshly Mole ratio after 12 days at ?26? C. prepared cyclic days at then heated to composition trimeric ?26? C. 20? C. Component (wt %) peroxides (wt %) (wt %) Isopar M 50.3 50.3 50.6 MEK 0.1 0.1 0.1 MPK 1.5 0.7 1.0 2MEK-cp 2.3 2.1 2.2 MEKMPK-cp 2.1 2.0 2.0 2MPK-cp 0.6 0.6 0.6 3MEK-cp 18.9 45.5 19.4 19.1 2MEK1MPK-cp 17.6 40.2 18.1 17.8 1MEK2MPK-cp 5.9 12.8 6.0 5.9 3MPK-cp 0.7 1.5 0.7 0.7

(8) No notable changes in the composition of the sample were observed, meaning that the composition was chemically stable under these conditions.

Example 2

(9) Example 1 was repeated using MEK and MPK in different mole ratios and the crystallization temperatures of the freshly prepared compositions of Examples 1 and 2 were determined by the method described above.

(10) All tests were performed in a test tube with a diameter of 28 mm. A sample of approx. 25 ml was poured into the test tube, the tube was closed tightly with a rubber stopper. The first temperature (T.sub.1) was ?15? C. As seeds, pure 3MEK-cp crystals were used.

(11) TABLE-US-00002 TABLE 2 MEK (mol %) 100 50 70 75 80 MPK (mol %) 0 50 30 25 20 Tcryst. (? C.) 0? C. ?28 <?28.sup.1 ?16 ?15 .sup.1no crystallization observed at ?28? C.

Example 3

(12) Examples 1 and 2 were repeated using methyl isobutyl ketone (MiBK) instead of methyl n-propyl ketone. The results are listed in Table 3.

(13) TABLE-US-00003 TABLE 3 Ketone(s) mole ratio other MEK:other Tcryst. than MEK ketone(s) (? C.) MPK 50:50 ?28 MiBK 90:10 ?20 MiBK 50:50 ?23

Example 4

(14) Examples 1 and 2 were repeated using of MEK, MPK, and methyl isopropyl ketone (MiPK) as the ketones, in a MEK:MPK:MiPK molar ratio of 70:15:15. The crystallization temperature of the resulting mixture was ?23? C. and the composition of the mixture is shown in Table 4.

(15) TABLE-US-00004 TABLE 4 Mole ratio cyclic trimeric Component peroxides 3MEK-cp 46.9 2MEK1MiPK-cp 16.7 2MEK1MPK-cp 24.3 1MEK2MiPK-cp 1.7 1MEK1MPK1MiPK-cp 5.4 1MEK2MPK-cp 4.2 2MiPK1MPK-cp 0.3 1MiPK2MPK-cp 0.3 3MPK-cp 0.2

Example 5

(16) Examples 1 and 2 were repeated using of MEK, MPK, and MiBK as the ketones, in a MEK:MPK:MiBK molar ratio of 70:27:3.

(17) Part of the resulting formulation was stored for three weeks at ?40? C.; another part was stored for three weeks at room temperature.

(18) No crystallization was observed in samples during this storage period. Nor did storage for one day at ?44? C. or 2 days at ?48? C. result in any crystallization. Also, no increase in explosive power was observed after storage at ?40? C. compared to storage at room temperature. The explosive power was five times lower than that of a crystallized sample obtained from MEK as the only ketone stored at ?15? C. (see table 2).

Example 6

(19) The peroxide composition resulting from Example 1 was used to degrade polypropylene and its effectiveness was compared with that of commercial 41 wt % 3MEK-cp in Isopar M (Trigonox? 301).

(20) Polypropylene (PP) degradation was performed at two different temperatures (190? C. and 225? C.) and at three different active oxygen contents (5.2 mg, 10.5 mg and 15.6 mg/100 g of PP).

(21) Polypropylene (750 g) was extruded using a Polylab OS system fitted with a Haake PTW16 extruder (co-rotating twin screw). Temperature settings: hopper at 30? C., zone 1 at 160? C. and zones 2-10 at 225? C. or 190? C.

(22) The melt flow index (MFI) of the degraded PP was measured and, as shown in Tables 5 and 6, it turned out that both peroxide compositions had the same efficiency in the degradation of PP, at all active oxygen contents and both temperatures. This shows that the composition according to the invention improves the safety of 3MEK-cp without impairing on efficiency.

(23) TABLE-US-00005 TABLE 5 PP degradation at 190? C. Active oxygen content (mg/100 g PP) 5.2 10.5 15.6 MFI at 230? C./2.16 kg (g/10 min): Trigonox? 301 16 40 75 Example 1 16 41 74

(24) TABLE-US-00006 TABLE 6 PP degradation at 225? C. Active oxygen content (mg/100 g PP) 5.2 10.5 15.6 MFI at 230? C./2.16 kg (g/10 min): Trigonox? 301 14 38 72 Example 1 14 37 77