EP3154936A1

EP3154936A1 - Organic solvent for peroxides

Info

Publication number: EP3154936A1
Application number: EP15736540.4A
Authority: EP
Inventors: Jean-Luc Dubois; Serge Hub; Alfredo Defrancisci
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2014-06-13
Filing date: 2015-06-08
Publication date: 2017-04-19
Also published as: FR3022251A1; CN106458882A; WO2015189508A1; US20170121280A1

Abstract

The invention relates to a peroxide solution of organic peroxide in an organic solvent, comprising at least one peroxide in a solvent, the solvent consisting of a hydrophobic alcohol wherein the main carbonated chain having the alcohol function comprises at least six carbon atoms, characterised in that it also comprises a second, hydrophilic alcohol solvent representing a maximum of 15% wt. % of the solution. The invention also relates to a thermohardenable composition comprising said solution, and to a method and a use relating to said composition.

Description

ORGANIC SOLVENT FOR PEROXIDES

Field of the invention

The subject of the invention is an organic solvent and at least one peroxide as well as the more particular use of this solvent for a particular class of hazardous organic peroxides.

It is understood that the application of this specific solvent to a dangerous peroxide, because of its decomposition and its risk of exothermic decomposition, is particularly indicated, considering the interest in this case, but it is not is in no way limited to such use and may be considered for other peroxides, given its properties.

Some peroxides are particularly dangerous and can, both during their manufacture and for their transport, decompose very rapidly exothermically and result in a fire or explosion. To avoid such risks, it is necessary to use a solvent of type A, defined as an organic solvent having a boiling point greater than 160 ° C, for their manufacture as their transport.

A well known class of such peroxides are ketone peroxides.

State of the art

Documents DE 3512829 or FR 2445341 may be used as a basis for disclosing a state of the art in the field.

Also known is US 3557009 which discloses some examples of peroxide solutions comprising an alcohol as an organic solvent, in this case 2-ethyl hexanol, without otherwise using a component of the phthalate family. It has been found by the Applicant that when a single alcohol was used as the organic solvent of a peroxide, the composition was not stable over time.

Two tests have been carried out and show for one that the synthesis with a single hydrophobic alcohol, in this case 2-ethyl-hexanol, as well as the synthesis with a A single hydrophilic alcohol, in this case DAA, does not make it possible to obtain a stable solution, at least after a certain period of time.

Test 1: Synthesis of a mixture of MEKP using only the hydrophobic alcohol 2-ethyl hexanol.

The peroxide obtained has a hazy / milky appearance. We were able to separate, by a decantation step at 16 ° C, a certain amount of aqueous phase, which was removed. We recovered the remaining organic phase, which still had this cloudy appearance and we neutralized it with 10% of a 3% solution of TBA (tributyl amine) in 2-ethyl hexanol. The product obtained always had this turbid and milky appearance. After a few hours spent (2 hours) in a refrigerator at 0 ° C, an aqueous phase separates: we can see several drops of a liquid to be deposited at the bottom of the vial containing the sample. The product is therefore not physically stable (phase separation) under realistic storage conditions for several countries in the winter season.

Test 2: Synthesis of a mixture of MEKP using only the hydrophilic alcohol DAA (diacetone alcohol).

The peroxide obtained has a single phase, colorless and transparent; it is therefore impossible for us to eliminate the aqueous phase, rich in residual sulfuric acid, by a decantation step.

The neutralization step is made by adding 10% of a 3% solution of tributyl amine in the DAA. The product obtained has a single phase. This sample could not pass, or satisfy, an accelerated aging test of 7 (seven) days at 50 ° C because it lost more than 10%> of the starting active oxygen content. The product is therefore not thermally stable and presumably it can not have a storage time at room temperature greater than 6 (six) months at room temperature.

Also known are GB 1072728, WO 2011/033232 and US 5808110 which mentions the use of an alcohol as the organic solvent of a peroxide composition. Nevertheless, the alcohol is always used in combination with another non-alcohol solvent, which induces certain negative characteristics, and especially does not allow, in particular for certain types of peroxides, to guarantee an optimal stability over time of the composition of peroxides. At present, solvents for this type of peroxide are conventionally used for dimethyl phthalate or diisobutyl phthalate. The major disadvantage of these solvents lies in the fact that it belongs to the family of phthalates which are chemicals for some considered harmful and have environmental disadvantages.

Also known as the main solvent such peroxides are methyl benzoate, aliphatic esters (especially TXIB ^® ) but none of these solvents are fully satisfactory.

Indeed, it is desirable in some applications to have a solution of solvent and at least one peroxide, which has the lowest viscosity possible so that it is easily dispersed in fine droplets, for example via a nozzle or gun.

In addition, an important criterion lies in the absence of release of gas from the mixture (peroxide + solvent) over time, for example during storage, this gas marking a significant deterioration of the properties / characteristics of the mixture.

Finally, when preparing a peroxide requiring the presence of a solvent are conventionally present a solution with an aqueous phase and an oily or organic phase (mixture of said organic solvent with the peroxide or peroxides) containing the peroxide or peroxides. Then, only the oily phase is useful and therefore recovered so that it is necessary that the decantation, or separation, of the two phases, organic and aqueous, is best performed. The decantation criterion of the solvent composition is therefore important.

At present, there is no solvent available on the market to ensure optimum safety for ketone-type peroxides and likely to also perform at best all of the properties and characteristics indicated above.

Brief description of the invention

It has been found, after various experiments and manipulations, and contrary to the teachings of the state of the art, that a mixture of specific alcohol, namely a hydrophobic alcohol and a hydrophilic alcohol, makes it possible to meet the requirements abovementioned, and in particular to offer optimum stability of the peroxide composition.

Furthermore, the organic peroxide solution according to the invention does not use any phthalate, ester or, in general, any of the organic solvents conventionally used until now to solubilize organic peroxides, and in particular certain families of organic peroxides. In fact, the solvents used up to now, in particular the conventional phthalates or esters, used alone or as a mixture, all have particular disadvantages.

The present invention intends to solve all of the technical problems related to these organic solvents by a combination of at least two alcohols, which alone makes it possible to keep the peroxide solution stable while overcoming the drawbacks of solutions of the prior art.

Those skilled in the art know that alcohols are polar components that may interact with water. It will not be inclined to consider their use as a peroxide solvent in a solution also containing an aqueous phase, the separation of the two phases being made difficult by the use of an alcohol.

Thus, the present invention relates to a solution of organic peroxide in an organic solvent, comprising at least one peroxide present in a solvent, the solvent consisting of a hydrophobic alcohol whose main carbon chain carrying the alcohol function comprises at least six carbon atoms. carbon, characterized in that it further comprises a second alcohol solvent, hydrophilic present at most up to 15% by weight of the solution.

According to a preferred embodiment of the invention, the peroxide is chosen from ketone peroxides. The invention indeed has a major interest for this family of peroxides.

The present invention has the further advantage that an alcohol (or more precisely a mixture of alcohol) used as a solvent and meeting the above requirements may preferably consist of a renewable product, that is to say obtained at from renewable raw materials, plant matter, and the stock of which can consequently be reconstituted over a short period on a human scale.

In practice, the renewable nature of a component comes from the fact that at least a portion of the carbon atoms is of renewable origin, this renewable origin part can be determined according to ASTM D 6866-06.

Unlike materials from fossil materials, renewable raw materials contain ^14C . All carbon samples from living organisms (animals or plants) are actually a mixture of 3 isotopes: ¹² C (representing about 98.892% ), ¹³ C (about 1, 108%) and ¹⁴ C (traces: 1, 2.10 ¹⁰ %). The ¹⁴ C / ¹² C ratio of living tissues is identical to that of the atmosphere. In the environment, ¹⁴ C exists in two main forms: in the form of carbon dioxide (C0 ₂ ), and in organic form, that is to say of carbon integrated in organic molecules.

In a living organism, the ¹⁴ C / ¹² C ratio is kept constant by the metabolism because the carbon is continuously exchanged with the external environment. The proportion of ¹⁴ C being constant in the atmosphere, it is the same in the body, as long as it is alive, since it absorbs this ¹⁴ C in the same way as the ¹² C ambient. The average ratio of ¹⁴ C / ¹² C is equal to 1, 2 × 10 ^-12 .

¹² C is stable, that is to say that the number of atoms of ¹² C in a given sample is constant over time. ¹⁴ C is radioactive, the number of atoms of ¹⁴ C in a sample decreases over time (t), its half-life being equal to 5730 years. The ¹⁴ C content is substantially constant since the extraction of renewable raw materials.

Preferably, the hydrophobic alcohol of the organic solvent according to the invention thus consists of octan-2-ol, more preferably obtained directly from the castor plant.

According to a possibility offered by the invention, the hydrophobic alcohol of the organic solvent according to the invention consists of 2-ethyl hexanol.

Other characteristics and particularities of the primary mixture of the invention are presented below: preferably, the proportion of solvent to that of peroxide is between 10% and 90% by weight of the solution, preferably between 35% and 65%;

according to one particularity of the invention, the peroxide is methyl ethyl ketone; preferably, the second hydrophilic alcohol consists of diacetone alcohol; according to a possibility offered by the invention, the solution consists solely of the organic solvent, a mixture of a hydrophobic alcohol and a hydrophilic alcohol, and the organic peroxide.

The invention also relates to a thermosetting polymerizable and / or crosslinkable composition, comprising at least monomer units and / or a polymer, characterized in that it comprises a solution as defined above.

Thermosetting resins acceptable for crosslinking in accordance with the process of the present invention include unsaturated polyester resins, vinyl ester resins, (meth) acrylate resins, polyurethanes, epoxy resins, and mixtures thereof such as blends. unsaturated polyester resins and epoxy resins or mixtures of different unsaturated polyester resins.

Preferred resins are (meth) acrylate resins, unsaturated polyester resins and vinyl ester resins.

In the context of the present invention, the terms "unsaturated polyester resins" and unsaturated polyester resins refer to the blend of unsaturated polyester resin and ethylenically unsaturated monomeric component. The term "(meth) acrylate resin" refers to the mixture of acrylate or methacrylate resin and ethylenically unsaturated monomeric component. The unsaturated polyester resins and the acrylate resins defined above are well known to those skilled in the art and are commercially available.

Unsaturated polyester resins adapted to be crosslinked according to the process of the present invention are called ortho-resins, iso-resins, iso-np resins, and dicyclopentadiene resins (DCPD). Examples of such resins are maleic, fumaric, allylic, vinyl and epoxy resins, bisphenol A resins, terephthalic resins and hybrid resins.

Vinyl ester resins include acrylic resins, based on, for example, methacrylate, diacrylate, dimethacrylate and oligomers thereof. An unsaturated polyester or vinyl ester resin may contain a monomer. Examples of suitable monomers are ethylenically unsaturated monomeric components such as styrene and styrene derivatives such as styrene o-methyl, toluene vinyl, indene, divinyl benzene, vinyl pyrrolidone, vinyl siloxane, vinyl caprolactam stilbene, but also diallyl phthalate, dibenzylidene acetone, allyl benzene, methyl methacrylate, methacrylate, (meth) acrylic acid, diacrylates, dimethacrylates, acrylamides, vinyl acetate, triallyl cyanurate, triallyl isocyanurate, allyl components which are for example used in optical applications (such as carbonate diallyl glycol (djjethylene), chlorostyrene, styrene tert-butyl, tert-butylacrylate, butanediol dimethacrylate and mixtures thereof.

Suitable examples of the (meth) acrylate reactive diluents are PEG200 di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 2,3-butanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, trimethylol propane di (meth) acrylate, neopentyl glycol di (meth) acrylate, diporpylene glycol di (meth) acrylate, tripropylene glycol di ( meth) acrylate, PPG250 di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylpropanetri (meth) acrylate, pentarythritol tetra (meth) acrylate, trimethylolpropanetri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycidyl (meth) acrylate, (bis) maleimides, (bis) citraconimides, (bis) itaconimides, and them.

The amount of ethylenically unsaturated monomer in the resin preferably represents at least 0.1% by weight of the unsaturated polyester or vinyl ester resin, more preferably at least 1%, and even more preferably at least 5% by weight. The amount of ethylenically unsaturated monomer preferably represents at most equal to 50% by weight by weight of the resin, more preferably at most 40% and even more preferably at most 35%.

The invention also relates to a use of two alcohols including a hydrophobic alcohol having a main chain, carrying the alcohol function, comprising at least six carbon atoms, preferably octan-2-ol or 2-ethyl-hexanol and a second hydrophilic alcohol present at most up to 15% by weight of the solution, as organic solvent of at least one peroxide, preferably chosen from ketone peroxides, and more particularly consisting of methyl ethyl ketone, in order to form a solution as defined above. The following description is given solely for illustrative and not limiting.

DETAILED DESCRIPTION OF THE INVENTION The present invention is intended primarily to ensure the security of the preparation of an organic peroxide ketone type. Nevertheless, the invention provides a solution comprising an organic solvent and a peroxide which intrinsically has properties far superior to those of the prior art. As regards the peroxide in the solution, it will be chosen preferentially in the family of ketone peroxides. The peroxides of this family are all in the following form:

I HOO- C- OOH

I

R

As examples of components belonging to the family of ketone peroxides, there may be mentioned in particular methyl ethyl ketone peroxide, acetalketone peroxide, methyl isobutyl ketone peroxide, methyl isopropyl ketone peroxide and cyclohexanone peroxide.

The invention is absolutely not limited to the use of the organic solvent with ketone peroxides and may be contemplated for all other peroxides.

The invention in the following is presented with tests relating only to a ketone peroxide, specifically methyl ethyl ketone peroxide, but further tests have shown that one obtained very satisfactory results and similar with different peroxides. As examples of other peroxides that may be envisaged in the context of the present invention, mention may be made of dialkyl peroxides (di-tert-butyl peroxides, dicumyl peoryxide, for example), diacyl peroxides (dibenzoyl peroxide, dilauroyl peroxide, di-2,4-dichlorobenzoyl peroxide for example), hydroperoxides (t-butyl hydroperoxide, α-cumyl hydroxperoyde, 1-phenyl-ethyl hydroperoxide for example), peroxyacids (the acid peroxyacetic acid, p-nitro-peroxybenzoic 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 peroxydicarbonate) butyl, di-2-butoxyethyl peroxydicarbonate for example), sulfonyl peroxides (peroxide acetylcyclohexanesulfonyl for example) and silyl peroxides (vinyltri- (t-butylperoxy) silane, cumylperoxytrimethylsilane, for example).

With regard to the alcohol in the solution, it has been found by the applicant that the remarkable properties presented above are obtained with alcohols having a main chain, the one bearing the alcohol function (OH), having at least six atoms. of carbon. Indeed, it has been found, with a pentanol, a significant degradation of the results obtained with hexanol.

In the following, the tests relating to the solution according to the invention are carried out with octan-2-ol and 2-ethyl-hexanol, but it has been demonstrated that other alcohols corresponding to the main definition of the present invention. invention presented comparable interesting results.

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

To this composition, it is possible to add various additive components which may include its metal salts intended to promote decomposition of organic peroxide into free radicals, copromotors of the decomposition of organic peroxide such as tertiary aromatic amines, acetyl acetone, ethyl acetoacetate or Ν, Ν-diethyl acetoacetamide; UV protection agents; processing agents, whose function is to improve the final appearance during its implementation, such as fatty amides, stearic acid and its salts, ethylene bis-stearamide or fluoropolymers; anti-fogging agents; anti-blocking agents such as silica or talc; fillers such as calcium carbonate and nanofillers such as clays; coupling agents such as silanes; antistatic agents; nucleating agents; pigments; dyes; plasticizers; fluidifiers and flame retardant additives such as aluminum or magnesium hydroxides.

This composition can be used to produce composite materials, such as resin / fiberglass laminates, or carbon fiber resin, or plant fiber resin, or resin / plastic fiber. It can also be used as a binder in the production of reconstituted minerals, such as reconstituted marble, reconstituted granites, aluminum hydroxide (Al (OH) 3), to name the most common.

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

These additives are generally used in contents of between 10 ppm and 10,000 ppm by weight relative to the weight of the final resin. Plasticizers, fluidifiers and flame retardant additives can reach amounts well above 10000 ppm.

Example of Preparation of a Solution According to the Invention

The preparation of the solution according to the invention, namely comprising the organic solvent according to the invention and at least one peroxide, is carried out in a completely conventional manner and well known to those skilled in the art.

Moreover, when the solvent according to the invention is used for the preparation / manufacture of organic peroxide, as for example in the case of ketone peroxides and more particularly methyl ethyl ketone, said preparation or said manufacture is in no way modified and only the peroxide used in the prior art as a solvent is replaced by a solvent according to the present invention.

Tests performed:

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

All these solutions contain exactly the same peroxide, in this case methyl ethyl ketone, and the same quantity ratio of the latter relative to the organic solvent, and this in order to strictly compare the properties of the organic solvent and its interaction and its synergies with the peroxide, it being recalled 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 families other than that of the ketone peroxides.

- Viscosity measurement

The viscosity measurement is carried out on the solutions using a HAAKE device

Viscotester VT550 equipped with an NT mobil at 20 ° C. It is necessary to obtain a solution whose viscosity is less than 15 mPa.s to allow its use in special circumstances, in particular for its projection in fine droplets using a narrow nozzle or a gun.

There is a viscosity of 13 mPa.s for the two solutions comprising methyl ethyl ketone and respectively octan-2-ol and diacetone and 2-ethyl hexanol with diacetone.

The solution comprising methyl ethyl ketone and DIBP has a viscosity of 31 mPa.s while those with TXIB and DMP both have a viscosity value equal to 16 mPa.s. - Measurement of gas production

This measurement corresponds to the "gassing test" which consists in measuring the deformation of a LDPE ("low-density polyethylene") bottle containing organic peroxide and hermetically sealed during a stay of five days in an oven at 50 ° C. This test uses a 60 ml PE bottle of oval shape marked with a mark at 2.5 inches (ie 6.35 cm, a thumb being 2.54 cm) from the bottom of the bottle. plastic. 30 ml of peroxide to be analyzed are deposited in this flask. The "gassing test" makes it possible to determine an "F" factor. This factor is calculated on the difference in level between the mark previously plotted at the beginning of the test at 2.5 inches and the final level of peroxide measured after five days at 50 ° C.

An acceptable Gassing Test Factor must be less than or equal to 2.

The detailed procedure is as follows:

- Tare with its stopper an oval PE bottle on which was previously drawn a mark at 2.5 inches,

- Introduce 30 ml of peroxide to be analyzed into this vial,

- Weigh this bottle again and deduce the mass of peroxide introduced,

- Squeeze the sides of the PE bottle until the level of the contents reaches the level of 2.5 inches, then seal the bottle tightly.

- Leave for 48h, the vials at room temperature to check the tightness of each of the plugs (the level of peroxide must always be at the line drawn),

- Place the vials in a ventilated oven at 50 ° C for 5 days,

- At the end of the test, weigh the bottle and deduce the mass loss,

- Measure the difference in level between the 2.5-inch mark and the final level of the peroxide. The "Gassing test" factor (F) is calculated by assigning one point per every 1/8 inch (0.3175 cm) between the final level of the liquid and the mark initially drawn at 2.5 inches. An F factor less than or equal to 2 indicates that the peroxide passes the gassing test.

It is noted after a period of 5 days that the internal volume of the bottle has remained stable (no apparent expansion of the bottle, nor any overpressure at the opening of said bottle) for the solution containing the mixture containing octane. 2-ol or 2-ethylhexanol and diacetone while the overpressure for the other solutions caused a significant deformation of the bottle due to the expansion of the gases released by the emulsions in question.

More specifically, the solution comprising TXIB gave a factor F of 0.63 corresponding to a drop in level in the LDPE bottle of 0.2 cm,

- Decantation measurement of the two organic and aqueous phases

In this test, about 300 g of methyl ethyl ketone peroxide are synthesized by adding the methyl ethyl ketone in 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 then adding a solution of acid and hydrogen peroxide. As soon as the reaction between the hydrogen peroxide and the MEK is complete, each of these solutions is an emulsion with a hazy appearance. They are placed in a separating funnel. The two phases are then allowed to settle.

It is found that the two phases, organic and aqueous, are perfectly separated after one minute in the two solutions according to the invention (octan-2-ol and 2-ethylhexanol) while for the solutions according to the art. previous, the separation times of the two phases are approximately as follows:

for the solution with the TXIB: between 10 and 15 minutes,

- for the solution with the DIBP: 10 minutes.

Claims

An organic peroxide solution in an organic solvent, comprising at least one peroxide present in a solvent, the solvent consisting of a hydrophobic alcohol whose main carbon chain, carrying the alcohol function, comprises at least six carbon atoms, characterized in that it further comprises a second alcohol solvent, hydrophilic, present at most up to 15% by weight of the solution.

2. Solution according to claim 1, characterized in that the peroxide is selected from ketone peroxides.

3. Solution according to claim 1 or 2, characterized in that the hydrophobic alcohol consists of octan-2-ol.

4. Solution according to one of claims 1 or 2, characterized in that the hydrophobic alcohol consists of 2-ethyl hexanol.

5. Solution according to any one of the preceding claims, characterized in that the proportion of solvent to that of peroxide is between 10% and 90% by weight of the solution, preferably between 35% and 65%.

6. Solution according to any one of the preceding claims, characterized in that the peroxide is methyl ethyl ketone.

7. Solution according to one of claims 1 to 6, characterized in that the second hydrophilic alcohol consists of diacetone alcohol.

8. Solution according to any one of the preceding claims, characterized in that it consists solely of the organic solvent, a mixture of a hydrophobic alcohol and a hydrophilic alcohol, and the organic peroxide.

9. Thermosetting composition polymerizable and / or crosslinkable, comprising at least monomer units and / or a polymer, characterized in that it comprises a solution according to any one of the preceding claims.

10. Use of two alcohols including a hydrophobic alcohol having a main chain, carrying the alcohol function, comprising at least six carbon atoms, preferably octan-2-ol or 2-ethyl-hexanol and a second hydrophilic alcohol present at more than 15% by weight of the solution, as organic solvent of at least one peroxide, preferably chosen by ketone peroxides, and more particularly by the methyl ethyl ketone, in order to form a solution according to any of claims 1 to 8.