ORGANIC SOLVENT FOR PEROXIDES

Abstract

A peroxide solution of organic peroxide in an organic solvent, including at least one peroxide in a solvent, the solvent having a hydrophobic alcohol wherein the main carbonated chain having the alcohol function includes at least six carbon atoms, the solution also including a second, hydrophilic alcohol solvent representing a maximum of 15% wt. % of the solution. Also, a thermohardenable composition including said solution, and a method and a use relating to the composition.

Claims

1. Solution of organic peroxide in an organic solvent, comprising at least one peroxide present in a solvent, the solvent consisting of a hydrophobic alcohol, the main carbon chain of which, carrying the alcohol functional group, comprises at least six carbon atoms, wherein the solution additionally comprises a second hydrophilic alcohol solvent present at most at a level of 15% by weight of the solution.

2. Solution as claimed in claim 1, wherein the peroxide is chosen from ketone peroxides.

3. Solution as claimed in claim 1, wherein the hydrophobic alcohol consists of octan-2-ol.

4. Solution as claimed in claim 1, wherein the hydrophobic alcohol consists of 2-ethylhexanol.

5. Solution as claimed in claim 1, wherein the proportion of solvent to the proportion of peroxide becomes established between 10% and 90% by weight of the solution.

6. Solution as claimed in claim 1, wherein the peroxide is methyl ethyl ketone peroxide.

7. Solution as claimed in claim 1, wherein the second hydrophilic alcohol consists of diacetone alcohol.

8. Solution as claimed in claim 1, wherein the solution consists of the organic solvent, a mixture of a hydrophobic alcohol and of a hydrophilic alcohol, and the organic peroxide.

9. Polymerizable and/or crosslinkable thermosetting composition comprising at least monomer units and/or a polymer, wherein the composition comprises a solution as claimed in claim 1.

10. A method of forming a solution, the method comprising using two alcohols, including a hydrophobic alcohol exhibiting a main chain, carrying the alcohol functional group, comprising at least six carbon atoms, and a second hydrophilic alcohol present at most at a level of 15% by weight of the solution, as organic solvent of at least one peroxide, in order to form a solution as claimed in claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0051] The present invention is intended first to ensure that the preparation of an organic peroxide of ketone type is made secure. Nevertheless, the invention provides a solution comprising an organic solvent and a peroxide which intrinsically comprises properties far superior to those of the prior art.

[0052] As regards the peroxide in the solution, it will preferably be chosen from the family of the ketone peroxides. The peroxides of this family all exist in the following form:

##STR00001##

[0053] Mention may in particular be made, as examples of components belonging to the family of the ketone peroxides, of methyl ethyl ketone peroxide, acetal ketone peroxide, methyl isobutyl ketone peroxide, methyl isopropyl ketone peroxide and cyclohexanone peroxide.

[0054] The invention is certainly not limited to the use of the organic solvent with ketone peroxides and can be envisaged for all the other peroxides. The invention in the continuation is presented with tests relating solely to a ketone peroxide, more specifically methyl ethyl ketone peroxide, but additional tests have made it possible to show that highly satisfactory and similar results are obtained with different peroxides.

[0055] Mention will thus be made, by way of illustration of other peroxides which can be envisaged in the context of the present invention, of dialkyl peroxides (di(t-butyl) peroxide, dicumyl peroxide, for example), diacyl peroxides (dibenzoyl peroxide, dilauroyl peroxide, di(2,4-dichlorobenzoyl) peroxide, for example), hydroperoxides (t-butyl hydroperoxide, -cumyl hydroperoxide, 1-phenylethyl hydroperoxide, for example), peroxyacids (peroxyacetic acid, p-nitroperoxybenzoic acid, for example), peroxyesters (t-butyl peroxyacetate, t-butyl peroxypivalate, t-butyl peroxybenzoate, for example), peroxyketals (1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(cumylperoxy)propane, for example), peroxydicarbonates (diisopropyl peroxydicarbonate, di(sec-butyl) peroxydicarbonate, di(2-butoxyethyl) peroxydicarbonate, for example), sulfonyl peroxides (acetyl cyclohexane sulfonyl peroxide, for example) and silyl peroxides (vinyltri(t-butylperoxy)silane, cumylperoxytrimethylsilane, for example).

[0056] As regards the alcohol in the solution, it has been found by the applicant company that the noteworthy properties presented above are obtained with alcohols exhibiting a main chain, that carrying the alcohol (OH) functional group, having at least six carbon atoms. This is because there has been found, with a pentanol, a notable deterioration in the results obtained with a hexanol.

[0057] In the continuation, the tests relating to the solution according to the invention are carried out with octan-2-ol and 2-ethylhexanol but it has been demonstrated that other alcohols corresponding to the main definition of the present invention exhibit comparable advantageous results.

[0058] As regards the polymerizable and/or crosslinkable composition according to the invention, it adds polymerizable monomer units and/or at least one crosslinkable polymer to the solution. In other words, the methyl ethyl ketone peroxide+octan-2-ol/2-ethylhexanol solution is more conventionally intended for the polymerization/crosslinking of thermosetting resins.

[0059] To this composition, different components or additives can optionally be added which can comprise metal salts intended to promote the decomposition of the organic peroxide to give free radicals, copromoters of the decomposition of the organic peroxide, such as tertiary aromatic amines, acetylacetone, ethyl acetoacetate or N,N-diethylacetoacetamide; UV protection agents; processing aids having the role of improving the final appearance during its use, such as fatty amides, stearic acid and its salts, ethylenebisstearamide or fluoropolymers; antifogging agents; antiblocking agents, such as silica or talc; fillers, such as calcium carbonate and nanofillers, such as, for example, clays; coupling agents, such as silanes; antistatic agents; nucleating agents; pigments; dyes; plasticizers; viscosity reducers and flame-retardant additives, such as aluminum or magnesium hydroxides.

[0060] This composition can be used to produce composite materials, such as resin/glass fiber or resin/carbon fiber or resin/plant fiber or resin/plastic fiber laminates.

[0061] It can also be used as binder in the production of reconstituted minerals, such as reconstituted marble, reconstituted granites or aluminum hydroxide (Al(OH).sub.3), to mention the commonest.

[0062] According to the invention, one or more crosslinking retarders can also be introduced into the composition, such as the antioxidant compounds of the family of hydroquinones and phenolic antioxidants.

[0063] These additives are generally used in contents of between 10 ppm and 10 000 ppm by weight, with respect to the final weight of resin. The plasticizers, the viscosity reducers and the flame-retardant additives can reach amounts much greater than 10 000 ppm.

[0064] Example of the Preparation of a Solution According to the Invention:

[0065] The solution according to the invention, namely comprising the organic solvent according to the invention and at least one peroxide, is prepared in a way which is completely conventional and well known to a person skilled in the art.

[0066] Furthermore, when the solvent according to the invention is used for the preparation/manufacture of the organic peroxide, such as, for example, in the case of ketone peroxides and more particularly of methyl ethyl ketone peroxide, said preparation or said manufacture is not in any way modified and only the peroxide used in the prior art as solvent is replaced by a solvent according to the present invention.

[0067] Tests Carried Out:

[0068] In the continuation, the solvents according to the invention which are tested are a mixture of octan-2-ol or 2-ethylhexanol and of diacetone alcohol and this solvent mixture is compared with the solvents typically used with organic ketone peroxides, namely TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate of the family of the aliphatic esters), DMP (dimethyl phthalate) and DIBP (diisobutyl phthalate), and also with an organic solution in which only a hydrophobic alcohol is used, namely 2-ethylhexanol.

[0069] All these solutions comprise exactly the same peroxide, in the case in point methyl ethyl ketone peroxide, and the same ratio of amount of the latter with respect to the organic solvent, this being the case in order to strictly compare the properties of the organic solvent and its interaction and its synergies with peroxide, the reader being reminded that additional tests have shown that the conclusions drawn from the experiments presented below are obtained in a substantially equivalent manner with other peroxides, in other words peroxides belonging to other families than that of the ketone peroxides.

[0070] Viscosity Measurement

[0071] The viscosity measurement is carried out on the solutions using a Haake Viscotester VT550 equipped with an NT spindle at 20 C. It is necessary to obtain a solution having a viscosity of less than 15 mPa.Math.s in order to allow its use under special circumstances, in particular for its projection as fine droplets using a narrow nozzle or using a gun.

[0072] A viscosity of 13 mPa.Math.s is recorded for the two solutions comprising methyl ethyl ketone peroxide and respectively octan-2-ol and also diacetone alcohol and 2-ethyl-hexanol with diacetone alcohol.

[0073] The solution comprising methyl ethyl ketone peroxide and DIBP exhibits a viscosity of 31 mPa.Math.s, while those with TXIB and DMP both exhibit a viscosity value equal to 16 mPa.Math.s.

[0074] Measurement of Gas Production

[0075] This measurement corresponds to the gassing test, which consists in measuring the deformation of a hermetically sealed low-density polyethylene (LDPE) bottle containing organic peroxide during a residence time of five days in an oven at 50 C. This test uses a 60 ml oval-shaped PE flask on which has been drawn a mark at 2.5 inches (i.e. 6.35 cm; an inch being equal to 2.54 centimeters) from the bottom of the plastic bottle. 30 ml of peroxide to be analyzed are deposited in this flask. The gassing test makes it possible to determine a factor F. This factor is calculated with regard to the difference in level between the mark drawn beforehand at the beginning of the test at 2.5 inches and the final level of peroxide measured after five days at 50 C.

[0076] An acceptable gassing test factor should be less than or equal to 2.

[0077] The detailed procedure is as follows: [0078] an oval PE flask on which a mark at 2.5 inches has been drawn beforehand is tared with its stopper, [0079] 30 ml of peroxide to be analyzed are introduced into this flask, [0080] this flask is weighed again and the weight of peroxide introduced is deduced therefrom, [0081] the sides of the PE bottle are pressed until the level of the contents reaches a level of 2.5 inches and then the bottle is hermetically stoppered, [0082] the flasks are left at ambient temperature for 48 h in order to confirm that each of the stoppers is satisfactorily airtight (the level of peroxide should still be at the level of the drawn line), [0083] the flasks are deposited in a ventilated oven at 50 C. for 5 days, [0084] at the end of the test, the flask is weighed and the loss in weight is deduced therefrom, [0085] the difference in the level between the mark of 2.5 inches and the final level of the peroxide is measured. The gassing test factor (F) is calculated by assigning one point per each th of an inch (0.3175 cm) between the final level of liquid and the mark drawn initially at 2.5 inches. A factor F of less than or equal to 2 indicates that the peroxide passes the gassing test.

[0086] It is found, after a period of time of 5 days, that the interior volume of the bottle has remained stable (no apparent expansion of the bottle nor any excess pressure on opening said bottle) for the solution comprising the mixture based on octan-2-ol or 2-ethylhexanol and diacetone alcohol, whereas the excess pressure for the other solutions has caused a major deformation of the bottle due to the expansion of the gases given off by the emulsions under consideration.

[0087] More specifically, the solution comprising TXIB gave a factor F of 0.63, corresponding to a fall in level in the LDPE bottle of 0.2 cm.

[0088] Measurement of Separation by Settling of the Two Organic and Aqueous Phases

[0089] In this test, approximately 300 g of methyl ethyl ketone peroxide are synthesized by adding methyl ethyl ketone to each of the solvents, the two (octan-2-ol and 2-ethyl-hexanol) according to the invention and the three (TXIB, DMP and DIBP) according to the prior art, and by then adding a solution of acid and of aqueous hydrogen peroxide solution. From the end of the reaction between the hydrogen peroxide and MEK, each of these solutions exists as an emulsion having a cloudy appearance. They are placed in a separating funnel. The two phases are subsequently left to separate by settling.

[0090] It is found that the two phases, organic and aqueous, have completely separated after one minute in the two solutions according to the invention (octan-2-ol and 2-ethylhexanol), whereas, for the solutions according to the prior art, the times for separation of the two phases are approximately as follows: [0091] for the solution with TXIB: between 10 and 15 minutes, [0092] for the solution with DIBP: 10 minutes.