FORMULATION OF DI(4-TERT-BUTYLCYCLOHEXYL) PEROXYDICARBONATE

Abstract

Powder formulation comprising 20-75 wt % of di(4-tert-butylcyclohexyl) peroxydicarbonate and 25-80 wt % of a phlegmatizer selected from the group consisting of ethylene glycol dibenzoate, phenyl benzoate, trimethylol propane tribenzoate, dimethylsulfon, ethylene glycol ditoluate, 1,3-propanediol ditoluate, ethylene glycol 4-tert-butylbenzoate, ethylene glycol monobenzoate monotoluate, 2,3-butanediol dibenzoate, 4-methylphenyl benzoate acid ester, and combinations thereof.

Claims

1-7. (canceled)

8. A powder formulation comprising: 20-75 wt % of di(4-tert-butylcyclohexyl) peroxydicarbonate, and 25-80 wt % of a phlegmatizer, wherein the phlegmatizer comprises one or more of ethylene glycol dibenzoate, phenyl benzoate, trimethylol propane tribenzoate, dimethylsulfon, ethylene glycol ditoluate, 1,3-propanediol ditoluate, ethylene glycol 4-tert-butylbenzoate, ethylene glycol monobenzoate monotoluate, 2,3-butanediol dibenzoate, and 4-methylphenyl benzoate acid ester.

9. The powder formulation according to claim 8, wherein the phlegmatizer comprises ethylene glycol dibutyrate.

10. The powder formulation according to claim 8, wherein the phlegmatizer comprises ethylene phenyl butyrate.

11. The powder formulation according to claim 8 comprising: 50-75 wt % of the di(4-tert-butylcyclohexyl) peroxydicarbonate; and 25-50 wt % of the phlegmatizer.

12. The powder formulation according to claim 8 comprising: 60-70 wt % of the di(4-tert-butylcyclohexyl) peroxydicarbonate; and 30-40 wt % of the phlegmatizer.

13. The powder formulation according to claim 12, wherein the phlegmatizer comprises ethylene glycol dibenzoate.

14. The powder formulation according to claim 8, further comprising 0.1-5.0 wt % of an anti-caking agent.

15. The powder formulation according to claim 14, wherein the anti-caking agent comprises silica.

16. The powder formulation according to claim 8, comprising essentially no water.

17. The powder formulation according to claim 14, substantially free of other components.

18. The powder formulation according to claim 8, consisting of the di(4-tert-butylcyclohexyl) peroxydicarbonate, the phlegmatizer, and an anti-caking agent.

19. The powder formulation according to claim 8, wherein the peroxide is characterized by a particle size d.sub.90 of less than 500 microns, and the phlegmatizer is characterized by a particle size d.sub.90 less 100 microns.

20. The powder formulation according to claim 19, wherein d.sub.90 of the peroxide is 1-40 microns and d.sub.90 of the phlegmatizer is 150-250 microns.

21. Process for the production of a powder formulation according to claim 8, comprising the step of physically mixing neat di(4-tert-butylcyclohexyl) peroxydicarbonate powder with the phlegmatizer.

22. The process according to clam 21, comprising adding a part of the phlegmatizer to a mixing device, thereafter adding the peroxide to the mixing device, and then adding the remaining part of the phlegmatizer to the mixing device.

23. A process for curing an unsaturated resin, comprising the step of adding the powder formulation of claim 8 to the resin and heating the resulting mixture at a temperature of 60-140 C.

24. The process according to claim 23, wherein the phlegmatizer comprises ethylene glycol dibutyrate.

25. The process according to claim 23, wherein the phlegmatizer comprises phenyl benzoate.

26. The process according to claim 23, wherein the resin comprises a polyester resin.

27. The process according to claim 23, wherein the resin comprises a vinyl ester resin or an acrylate resin.

Description

EXAMPLES

Reference Example 1

[0034] Ethylene glycol dibenzoate (EGDB) flakes were milled to a d90 particle size of about 225 microns.

[0035] Different amounts of silica (MFIL-P(S), ex-Madhu Silica) were added after said milling.

[0036] The influence of silica on caking of EGDB was studied with caking tests, which were performed as follows.

[0037] Cylinders with a diameter of 40 mm diameter were filled with 30 gram EGDB. On top of the material, a weight was placed of either 240, 300, or 500 grams. The cylinders were stored in an oven for 48 hours, at either 30 C. or 40 C.

[0038] After cooling down, EGDB was removed from the cylinders and caking was judged visually. The results are displayed in Table 1, in which: [0039] severe caking means: the cake remained a cake after removal of the cylinder and was hard to break up; [0040] caking means: the cake remained a cake after removal of the cylinder but was easy to break up; [0041] slight caking means: the cake broke during removal of the cylinder, but small, easy to break up lumps remained; [0042] no caking means: the cake broke during removal of the cylinder and no lumps remained.

TABLE-US-00001 TABLE 1 Silica (wt %) T ( C.) Weight (g) 0 0.25 0.5% 0.75 1 30 C. 240 ND.sup.1 ND ND No caking No caking 30 C. 300 No caking No caking 30 C. 500 Slight No caking caking 40 C. 240 Severe Caking Caking No caking No caking caking 40 C. 300 Severe Caking Caking No caking No caking caking 40 C. 500 Severe Caking Caking Slight No caking caking caking .sup.1ND = not determined

Example 2

[0043] Five formulations were prepared, each comprising di(4-tert-butylcyclohexyl) peroxydicarbonate and either (i) EGDB or (ii) EGDB containing 1 wt % silica as prepared in Example 1: [0044] Formulation A comprising 60 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in EGDB. [0045] Formulation B1 comprising 70 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in EGDB. [0046] Formulation B2 comprising 70 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in EGDB comprising 1 wt % silica as prepared in Example 1. [0047] Formulation Cl comprising 80 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in EGDB. [0048] Formulation C2 comprising 80 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in EGDB comprising 1 wt % silica as prepared in Example 1. [0049] Formulation D comprising 70 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in glycerol tribenzoate. [0050] Formulation E comprising 70 wt % di(4-tert-butylcyclohexyl) peroxydicarbonate in phenyl benzoate.

[0051] These formulations where prepared by first de-agglomerating EGDB, GTB, and phenyl benzoate flakes in a Retsch hammer mill (type SK-1, rotational speed: 2800 rpm, Sieve: 1.5 mm), followed by mixing di(4-tert-butylcyclohexyl) peroxydicarbonate (Perkadox 16, ex-AkzoNobel) with the de-agglomerated powder in a Kitchenaid Heavy Duty mixer, type KSSS, for 5 minutes.

[0052] Formulations B1 and B2 were subjected to a segregation test.

[0053] A sample was charged into a 15 tilted cylinder (stainless steel, 50 cm length, 10 cm diameter) and slowly rotated (7-8 rpm) around it's longitudinal axis. After 20 minutes, rotation was stopped and samples were taken from the upper, middle and lower part of the cylinder.

[0054] The peroxide content of all samples was determined by iodometric titration, by dissolving the sample in THF, adding KI, and titrating with sodium thiosulphate. The results (see Table 2) show that the samples differed in less than 5%, meaning that the tendency for segregation is negligible.

TABLE-US-00002 TABLE 2 Formulation B1 Formulation B2 Overall formulation 69.8 70.2 Upper layer 69.6 70.0 Middle layer ND 70.1 Lower layer 70.7 69.5 .sup.1 ND = not determined

Example 3

[0055] In order to study the solubility of the formulations in different resins and in styrene, 0.5 grams of the formulations were added to a 100 ml beaker containing 50 gram resin or styrene and stirred with an overhead pitched blade stirrer (40 mm) at 4 rpm. Dissolution speed was judged visually. The results are compared with that of neat di(4-tert-butylcyclohexyl) peroxydicarbonate.

[0056] The following resins were used: [0057] Palatal P4 (a styrene-containing unsaturated polyester resin ex-DSM) [0058] Duracon 205 (an acrylate resin ex-Polyplastics)

[0059] Table 3 shows that the formulations all dissolve as quickly as or even quicker than neat di(4-tert-butylcyclohexyl) peroxydicarbonate.

TABLE-US-00003 TABLE 3 Dissolution speed in: Palatal P4 Duracon styrene neat 10.5 min 3.5 min <10 sec Formulation C1 10.5 min Formulation B1 8.0 min 3.0 min Formulation A 6.0 min <10 sec

Example 4

[0060] Neat di(4-tert-butylcyclohexyl) peroxydicarbonate and formulations A, B1, C1, D, and E were subjected to burning tests. In these tests, 202 cm strips of the formulations were made on a flat stainless steel plate.

[0061] The strips were ignited by a yellow gas flame. The time required to burn the entire 20 cm strip was measured and listed in Table 4.

TABLE-US-00004 TABLE 4 formulation Time (sec) A 55 B1 18 C1 11 D 6 E (ignites but extinguishes in a few sec. neat 5

Example 5

[0062] Formulations B2 and C2 were subjected to external fire tests by the German Bundesanstalt fr Materialforschung und prfung (BAM) in order to determine the burning rate and the corresponding storage.

[0063] Of each formulation, 17 packages (4G cardboard boxes with an inner plastic bag) were provided, each package containing 11.34 kg formulation.

[0064] One package was placed on one wooden pallet and surrounded with wood wool. The wooden pallet and the wood wool were ignited using a mixture of liquid fuels and an igniter. The irradiance was measured using infrared sensors arranged in pairs. The irradiance is a measure for the burning time, which can be used to calculate the burning rate.

[0065] The same experiment was repeated with six packages on one pallet and with ten packages on one pallet.

[0066] The burning rate of formulation B2 was 237 kg/min, which means that it is classified as US (NFPA 400) Class II (burning rate between 60 and 300 kg/min).

[0067] The burning rate of formulation C2 was 1018 kg/min, which means that it is classified as US (NFPA 400) Class I (burning rate between above 300 kg/min).

Example 6

[0068] To 100 g unsaturated polyesters resin (Palatal P4), 100 g of quartz filler (Quarz Mehl M6) was added. After stirring, a peroxide (formulation) was added in an amount corresponding to 0.5 g neat peroxide.

[0069] The resulting mixture was poured into a test tube containing a thermocouple. The test tube was heated in a water bath of 82 C. The temperature of the mixture was recorded in time.

[0070] The Geltime (GT) is the time required for the mixture temperature to increase from 63.3 C. to 85.6 C.

[0071] The time to peak (TTP) is the time required to reach the maximum temperature.

[0072] The peak exotherm (PE) is the maximum temperature reached.

[0073] The minimum cure time (MCT) is the time lapsed starting from 63.3 C. until the maximum temperature.

TABLE-US-00005 TABLE 5 Palatal P4 (g) 100 100 100 100 100 100 100 Quarz (g) 100 100 100 Perkadox 16 (g) 0.500 0.500 Formulation A (g) 0.794 0.794 Formulation B1 (g) 0.681 0.681 Formulation B2 (g) 0.681 GT (min) 2.0 2.1 2.1 2.2 1.9 1.9 2.0 MCT (min) 3.7 4.0 3.9 4.4 4.1 4.2 4.1 TTP (min) 5.6 6.2 6.2 8.2 7.6 7.7 8.2 PE ( C.) 117.6 115.9 120.3 165.4 161.3 159.2 163.2

[0074] These results show that EGDB does not negatively influence the cure of polyester resins.

Example 7

[0075] Example 6 was repeated except that the temperature of the water bath was 70 C.

[0076] The results are displayed in Table 6, and again show that EGDB does not negatively influence the cure of polyester resin.

TABLE-US-00006 TABLE 6 Palatal P4 (g) 100 100 100 100 Quarz (g) Perkadox 16 (g) 0.500 Formulation A (g) 0.794 Formulation B1 (g) 0.681 Formulation B2 (g) 0.681 GT (min) 5.5 4.7 5.3 5.7 MCT (min) 8.8 8.0 8.4 8.8 TTP (min) 13.3 11.5 12.2 13.2 PE ( C.) 147.5 144.8 146.5 146.7

[0077] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the various embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment as contemplated herein. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the various embodiments as set forth in the appended claims.